WorldWideScience

Sample records for underlying physical principle

  1. Cosmological principles. II. Physical principles

    International Nuclear Information System (INIS)

    Harrison, E.R.

    1974-01-01

    The discussion of cosmological principle covers the uniformity principle of the laws of physics, the gravitation and cognizability principles, and the Dirac creation, chaos, and bootstrap principles. (U.S.)

  2. Variational principles in physics

    CERN Document Server

    Basdevant, Jean-Louis

    2007-01-01

    Optimization under constraints is an essential part of everyday life. Indeed, we routinely solve problems by striking a balance between contradictory interests, individual desires and material contingencies. This notion of equilibrium was dear to thinkers of the enlightenment, as illustrated by Montesquieu’s famous formulation: "In all magistracies, the greatness of the power must be compensated by the brevity of the duration." Astonishingly, natural laws are guided by a similar principle. Variational principles have proven to be surprisingly fertile. For example, Fermat used variational methods to demonstrate that light follows the fastest route from one point to another, an idea which came to be known as Fermat’s principle, a cornerstone of geometrical optics. Variational Principles in Physics explains variational principles and charts their use throughout modern physics. The heart of the book is devoted to the analytical mechanics of Lagrange and Hamilton, the basic tools of any physicist. Prof. Basdev...

  3. Principles & practice of physics

    CERN Document Server

    Mazur, Eric; Dourmashkin, Peter A; Pedigo, Daryl; Bieniek, Ronald J

    2015-01-01

    Putting physics first Based on his storied research and teaching, Eric Mazur's Principles & Practice of Physics builds an understanding of physics that is both thorough and accessible. Unique organization and pedagogy allow you to develop a true conceptual understanding of physics alongside the quantitative skills needed in the course. *New learning architecture: The book is structured to help you learn physics in an organized way that encourages comprehension and reduces distraction.*Physics on a contemporary foundation: Traditional texts delay the introduction of ideas that we now see as unifying and foundational. This text builds physics on those unifying foundations, helping you to develop an understanding that is stronger, deeper, and fundamentally simpler.*Research-based instruction: This text uses a range of research-based instructional techniques to teach physics in the most effective manner possible. The result is a groundbreaking book that puts physics first, thereby making it more accessible to...

  4. Principles of modern physics

    CERN Document Server

    Saxena, A K

    2014-01-01

    Principles of Modern Physics, divided into twenty one chapters, begins with quantum ideas followed by discussions on special relativity, atomic structure, basic quantum mechanics, hydrogen atom (and Schrodinger equation) and periodic table, the three statistical distributions, X-rays, physics of solids, imperfections in crystals, magnetic properties of materials, superconductivity, Zeeman-, Stark- and Paschen Back- effects, Lasers, Nuclear physics (Yukawa's meson theory and various nuclear models), radioactivity and nuclear reactions, nuclear fission, fusion and plasma, particle accelerators and detectors, the universe, Elementary particles (classification, eight fold way and quark model, standard model and fundamental interactions), cosmic rays, deuteron problem in nuclear physics, and cathode ray oscilloscope. NEW TO THE FOURTH EDITION: The CO2 Laser Theory of magnetic moments on the basis of shell model Geological dating Laser Induced fusion and laser fusion reactor. Hawking radiation The cosmological red ...

  5. Thermo-Physical Properties of Ammonium Azide under High Pressure from First-Principles

    Science.gov (United States)

    Landerville, Aaron; Steele, Brad; Oleynik, Ivan

    2013-03-01

    Polynitrogen compounds offer tremendous promise for use as insensitive high-explosives or propellants. While the existence of such compounds have been observed in Diamond Anvil Cells (DAC) under high pressure, recovery to ambient pressure and temperature has proven problematic. A current thrust towards the recovery, and ultimate manufacture, of materials rich in polymeric nitrogen has brought renewed attention to various nitrogen-rich compounds, particularly crystalline azides, as possible precursors. We investigate the thermo-physical properties and Raman spectra of one azide candidate - ammonium azide - under hydrostatic compression using density functional theory with an empirical van der Waals correction. Additionally, we perform structural minima searches to discern possible polymorphs that may help to elucidate dynamical processes leading to the production of a material rich in polymeric nitrogen, as well as its recovery from DAC.

  6. Physical principles in chemoreception

    CERN Document Server

    Wiegel, Frederik W

    1991-01-01

    Is it not sheer foolishness to try to apply the methods of theoretical physics to biological structures? Physics flowered because it limited itself to the study of very simple systems; on the other hand, the essence of "living things" seems to have to do with the extreme intricacy of their structure. Is it a hopeless endeavour to attempt to bring the two together, or should one try nevertheless? Most of my colleagues in theoretical physics feel one should not waste one's time and stick to "the good old hydrogen atom", but some of them feel one should try anyhow. This minority point of view was shared by Bohr in the thirties, Schrödinger in the fourties, Delbrück in the fifties and sixties, PurceIl in the seventies, etc. The theory of chemoreception represents only a very small part of this immense scientific question. Its study was started by Delbriick and others in the fifties. I was introduced to these problems by Charles DeLisi, during a visit to the National Institutes of Health in the summer of 1980. D...

  7. A cyclic symmetry principle in physics

    International Nuclear Information System (INIS)

    Green, H.S.; Adelaide Univ., SA

    1994-01-01

    Many areas of modern physics are illuminated by the application of a symmetry principle, requiring the invariance of the relevant laws of physics under a group of transformations. This paper examines the implications and some of the applications of the principle of cyclic symmetry, especially in the areas of statistical mechanics and quantum mechanics, including quantized field theory. This principle requires invariance under the transformations of a finite group, which may be a Sylow π-group, a group of Lie type, or a symmetric group. The utility of the principle of cyclic invariance is demonstrated in finding solutions of the Yang-Baxter equation that include and generalize known solutions. It is shown that the Sylow π-groups have other uses, in providing a basis for a type of generalized quantum statistics, and in parametrising a new generalization of Lie groups, with associated algebras that include quantized algebras. 31 refs

  8. Physical Consequences of Mathematical Principles

    Directory of Open Access Journals (Sweden)

    Comay E.

    2009-10-01

    Full Text Available Physical consequences are derived from the following mathematical structures: the variational principle, Wigner’s classifications of the irreducible representations of the Poincar ́ e group and the duality invariance of the homogeneous Maxwell equations. The analysis is carried out within the validity domain of special relativity. Hierarchical re- lations between physical theories are used. Some new results are pointed out together with their comparison with experimental data. It is also predicted that a genuine Higgs particle will not be detected.

  9. Physical acoustics principles and methods

    CERN Document Server

    Mason, Warren P

    1964-01-01

    Physical Acoustics: Principles and Methods, Volume l-Part A focuses on high frequency sound waves in gases, liquids, and solids that have been proven as powerful tools in analyzing the molecular, defect, domain wall, and other types of motions. The selection first tackles wave propagation in fluids and normal solids and guided wave propagation in elongated cylinders and plates. Discussions focus on fundamentals of continuum mechanics; small-amplitude waves in a linear viscoelastic medium; representation of oscillations and waves; and special effects associated with guided elastic waves in plat

  10. Ultrasound physical principles in today's technology.

    Science.gov (United States)

    Starkoff, Brian

    2014-02-01

    Introduction : New technology options are being provided on modern ultrasound machines such as tissue harmonic imaging, panoramic imaging, encoded pulses, mechanical and matrix 4D ultrasound and elastography. The increase in available features requires enhanced knowledge of the clinical benefits associated with each feature and of the additional diagnostic information in the images. However the question arises as to the necessity of understanding how these new technologies work. Also, ultrasound machines have become much more automated in recent years, with designers making it easier for users to produce excellent quality images with minimal technical input. Discussion : System presets provide adjustments to a variety of basic settings without the user requiring the knowledge of what each setting is doing. The developments in machine design and the increased level of automation pose an interesting question for sonologists and sonographers: Is there a need to know as much about the physical principles of ultrasound today as was required in the past? Conclusion : To answer this question, this article will look at just one recent advance in ultrasound - Tissue Harmonic Imaging. The various mechanisms of this technology will be discussed with reference to the underlying principles of basic ultrasound physics. The conclusion provided is that a good grounding in the physics of ultrasound remains of vital importance in understanding new technologies and enabling informed decisions to be made on their use.

  11. Principles and applications of nanomems physics

    CERN Document Server

    Santos, Hector

    2005-01-01

    ""Principles and Applications of NanoMEMS Physics"" presents the first unified exposition of the physical principles at the heart of NanoMEMS-based devices and applications. In particular, after beginning with a comprehensive presentation of the fundamentals and limitations of nanotechnology and MEMS fabrication techniques, the book addresses the physics germane to this dimensional regime, namely, quantum wave-particle phenomena, including, the manifestation of charge discreteness, quantized electrostatic actuation, and the Casimir effect, and quantum wave phenomena, including, quantized elect

  12. Building physics from physical principles to international standards

    CERN Document Server

    Pinterić, Marko

    2017-01-01

    This textbook provides thorough coverage of the most important building physics phenomena: heat transfer, moisture, sound/acoustics, and illumination. Since the book is primarily aimed at engineers, it addresses professional issues with due pragmatism, and by including many practical examples and related ISO standards. Nevertheless, in order to guarantee full comprehension, it also explains the underlying physical principles and relates them to practical aspects in a simple and clear way. This is achieved with the aid of more than 100 figures and consistent cross-referencing of formulas and ideas. In addition, interrelationships between the different building physics phenomena are elucidated in a way that will enable readers to develop performance specifications that inform the design process. The book will primarily appeal to students of civil engineering and architecture, as well as to all practitioners in these areas who wish to broaden their fundamental understanding of topics in building physics.

  13. Nuclear physics principles and applications

    CERN Document Server

    Lilley, J S

    2001-01-01

    This title provides the latest information on nuclear physics. Based on a course entitled Applications of Nuclear Physics. Written from an experimental point of view this text is broadly divided into two parts, firstly a general introduction to Nuclear Physics and secondly its applications.* Includes chapters on practical examples and problems* Contains hints to solving problems which are included in the appendix* Avoids complex and extensive mathematical treatments* A modern approach to nuclear physics, covering the basic theory, but emphasising the many and important applicat

  14. 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)

  15. [Physical principles and general considerations].

    Science.gov (United States)

    Alfageme Roldán, F; Mollet Sánchez, J; Cerezo López, E

    2015-11-01

    Cutaneous ultrasound is based on the application of the physical properties of ultrasound to the skin and cutaneous adnexae. Knowledge of ultrasound semiology, artifacts and the application of Doppler examination allows deeper study of the biology and diseases of the skin and its adnexae. Copyright © 2015 Academia Española de Dermatología y Venereología. Published by Elsevier España, S.L.U. All rights reserved.

  16. Vapourisers: Physical principles and classification

    Directory of Open Access Journals (Sweden)

    Vithal Dhulkhed

    2013-01-01

    Full Text Available Vapourisers have evolved from rudimentary inhalers to the microprocessor controlled, temperature compensated and flow sensing devices, which are universal today. The improvements in the design was influenced by the development of potent inhalational anaesthetics, unique properties of some agents, a deeper understanding of their mechanism of action, inherent flaws in the older vapourisers, mechanical problems due to thymol deposition, factors influencing their output such as temperature and pressure variations. It is important to review the principles governing the design of the vapouriser to gain insight into their working. It is fascinating to know how some of the older vapourisers, popularly used in the past, functioned. The descendant of Oxford Miniature Vapourizer, the Triservice vapouriser is still a part of the military anaesthesia draw over equipment meant for field use whereas the Copper Kettle the first precision device is the fore-runner of the Tec 6 and Aladdin cassette vapouriser. Anaesthesia trainees if exposed to draw over techniques get a deeper understanding of equipment and improved skills for disaster situations. In the recent advanced versions of the vapouriser a central processing unit in the anaesthetic machine controls the operation by continuously monitoring and adjusting fresh gas flow through the vapouriser to maintain desired concentration of the vapour.

  17. The physical principles of rock magnetism

    CERN Document Server

    Stacey, Frank

    1974-01-01

    Developments in Solid Earth Geophysics 5: The Physical Principles of Rock Magnetism explores the physical principles of rock magnetism, with emphasis on the properties of finely divided magnetic materials. It discusses the origin and stability of rock magnetizations, the role of remanent magnetism in interpreting magnetic surveys, magnetic anisotropy as an indicator of rock fabric, and the relationship between piezomagnetic changes and seismic activity. Organized into 13 chapters, this volume discusses the properties of solids, magnetite and hematite grains, and rocks with magnetite grains

  18. Physical acoustics v.8 principles and methods

    CERN Document Server

    Mason, Warren P

    1971-01-01

    Physical Acoustics: Principles and Methods, Volume VIII discusses a number of themes on physical acoustics that are divided into seven chapters. Chapter 1 describes the principles and applications of a tool for investigating phonons in dielectric crystals, the spin phonon spectrometer. The next chapter discusses the use of ultrasound in investigating Landau quantum oscillations in the presence of a magnetic field and their relation to the strain dependence of the Fermi surface of metals. The third chapter focuses on the ultrasonic measurements that are made by pulsing methods with velo

  19. Physics Without Physics. The Power of Information-theoretical Principles

    Science.gov (United States)

    D'Ariano, Giacomo Mauro

    2017-01-01

    holds for all energies ever tested (and even much larger), where the usual free quantum field theory is perfectly recovered. In the present quantum discrete theory Einstein relativity principle can be restated without using space-time in terms of invariance of the eigenvalue equation of the automaton/walk under change of representations. Distortions of the Poincaré group emerge at the Planck scale, whereas special relativity is perfectly recovered in the relativistic regime. Discreteness, on the other hand, has some plus compared to the continuum theory: 1) it contains it as a special regime; 2) it leads to some additional features with GR flavor: the existence of an upper bound for the particle mass (with physical interpretation as the Planck mass), and a global De Sitter invariance; 3) it provides its own physical standards for space, time, and mass within a purely mathematical adimensional context. The paper ends with the future perspectives of this project, and with an Appendix containing biographic notes about my friendship with David Finkelstein, to whom this paper is dedicated.

  20. Molecular physics. Theoretical principles and experimental methods

    International Nuclear Information System (INIS)

    Demtroeder, W.

    2005-01-01

    This advanced textbook comprehensively explains important principles of diatomic and polyatomic molecules and their spectra in two separate, distinct parts. The first part concentrates on the theoretical aspects of molecular physics, whereas the second part of the book covers experimental techniques, i.e. laser, Fourier, NMR, and ESR spectroscopies, used in the fields of physics, chemistry, biolog, and material science. Appropriate for undergraduate and graduate students in physics and chemistry with a knowledge of atomic physics and familiar with the basics of quantum mechanics. From the contents: - Electronic States of Molecules, - Rotation, Oscillation and Potential Curves of Diatomic Molecules, - The Spectra of Diatomic Molecules, - Molecule Symmetries and Group Theory, - Rotation and Oscillations of Polyatomic Molecules, - Electronic States of Polyatomic Molecules, - The Spectra of Polyatomic Molecules, - Collapse of the Born-Oppenheimer-Approximation, Disturbances in Molecular Spectra, - Molecules in Disturbing Fields, - Van-der-Waals-Molecules and Cluster, - Experimental Techniques in Molecular Physics. (orig.)

  1. Physics of electronic materials principles and applications

    CERN Document Server

    Rammer, Jorgen

    2017-01-01

    Adopting a uniquely pedagogical approach, this comprehensive textbook on the quantum mechanics of semiconductor materials and devices focuses on the materials, components and devices themselves whilst incorporating a substantial amount of fundamental physics related to condensed matter theory and quantum mechanics. Written primarily for advanced undergraduate students in physics and engineering, this book can also be used as a supporting text for introductory quantum mechanics courses, and will be of interest to anyone interested in how electronic devices function at a fundamental level. Complete with numerous exercises, and with all the necessary mathematics and physics included in appendices, this book guides the reader seamlessly through the principles of quantum mechanics and the quantum theory of metals and semiconductors, before describing in detail how devices are exploited within electric circuits and in the hardware of computers, for example as amplifiers, switches and transistors. Includes nume...

  2. Solid state physics principles and modern applications

    CERN Document Server

    Quinn, John J

    2018-01-01

    This book provides the basis for a two-semester graduate course on solid-state physics. The first half presents all the knowledge necessary for a one-semester survey of solid-state physics, but in greater depth than most introductory solid state physics courses. The second half includes most of the important research over the past half-century, covering both the fundamental principles and most recent advances. This new edition includes the latest developments in the treatment of strongly interacting two-dimensional electrons and discusses the generalization from small to larger systems. The book provides explanations in a class-tested tutorial style, and each chapter includes problems reviewing key concepts and calculations. The updated exercises and solutions enable students to become familiar with contemporary research activities, such as the electronic properties of massless fermions in graphene and topological insulators.

  3. Thermodynamics principles characterizing physical and chemical processes

    CERN Document Server

    Honig, Jurgen M

    1999-01-01

    This book provides a concise overview of thermodynamics, and is written in a manner which makes the difficult subject matter understandable. Thermodynamics is systematic in its presentation and covers many subjects that are generally not dealt with in competing books such as: Carathéodory''s approach to the Second Law, the general theory of phase transitions, the origin of phase diagrams, the treatment of matter subjected to a variety of external fields, and the subject of irreversible thermodynamics.The book provides a first-principles, postulational, self-contained description of physical and chemical processes. Designed both as a textbook and as a monograph, the book stresses the fundamental principles, the logical development of the subject matter, and the applications in a variety of disciplines. This revised edition is based on teaching experience in the classroom, and incorporates many exercises in varying degrees of sophistication. The stress laid on a didactic, logical presentation, and on the relat...

  4. The physical principles of the quantum theory

    CERN Document Server

    Heisenberg, Werner Karl

    1930-01-01

    The contributions of few contemporary scientists have been as far reaching in their effects as those of Nobel Laureate Werner Heisenberg. His matrix theory is one of the bases of modern quantum mechanics, while his ""uncertainty principle"" has altered our whole philosophy of science.In this classic, based on lectures delivered at the University of Chicago, Heisenberg presents a complete physical picture of quantum theory. He covers not only his own contributions, but also those of Bohr, Dirac, Bose, de Broglie, Fermi, Einstein, Pauli, Schrodinger, Somerfield, Rupp, ·Wilson, Germer, and others

  5. On the superposition principle and its physics content

    International Nuclear Information System (INIS)

    Roos, M.

    1984-01-01

    What is commonly denoted the superposition principle is shown to consist of three different physical assumptions: conservation of probability, completeness, and some phase conditions. The latter conditions form the physical assumptions of the superposition principle. These phase conditions are exemplified by the Kobayashi-Maskawa matrix. Some suggestions for testing the superposition principle are given. (Auth.)

  6. A New Principle in Physics: the Principle 'Finiteness', and Some Consequences

    International Nuclear Information System (INIS)

    Sternlieb, Abraham

    2010-01-01

    In this paper I propose a new principle in physics: the principle of 'finiteness'. It stems from the definition of physics as a science that deals (among other things) with measurable dimensional physical quantities. Since measurement results, including their errors, are always finite, the principle of finiteness postulates that the mathematical formulation of 'legitimate' laws of physics should prevent exactly zero or infinite solutions. Some consequences of the principle of finiteness are discussed, in general, and then more specifically in the fields of special relativity, quantum mechanics, and quantum gravity. The consequences are derived independently of any other theory or principle in physics. I propose 'finiteness' as a postulate (like the constancy of the speed of light in vacuum, 'c'), as opposed to a notion whose validity has to be corroborated by, or derived theoretically or experimentally from other facts, theories, or principles.

  7. Provincial responsibility for carbon emissions in China under different principles

    International Nuclear Information System (INIS)

    Zhang, Youguo

    2015-01-01

    By applying a multi-regional input–output model, the study compares the provincial responsibility for carbon emissions and provincial carbon multipliers in China under seven responsibility-allocating principles, including three basic principles, the production, income and consumption principles, and four shared responsibility principles, the income-weighted, consumption weighted, comprehensive, and weighted comprehensive principles. Empirical results indicate that carbon multipliers of provinces under these principles are significantly different from one another. The carbon multipliers of provinces with higher ratios of carbon intensive sectors in their outputs are also larger. At the same time, the carbon multipliers of the same sector in the provinces are significantly different from one another. Changing the principle causes significant changes in the responsibility for carbon emissions of some provinces, but only slight changes in the responsibilities of some other provinces. However, the responsibilities of provinces with large economic sizes (output) are always the largest, whereas provinces with the smallest economic sizes are always the smallest regardless of the principles. Further, this study proposes a series of regional policies for carbon mitigation according to provincial carbon multipliers and responsibility allocation features under the different principles. - Highlights: • We link regional environmental responsibility to seven benefit principles. • We analyze provincial responsibility for carbon emissions in China. • We also report provincial carbon multipliers under different principles. • We compare the seven principles from the regional perspective. • Policy implications of the study are discussed.

  8. Basic principles of chemistry and physical chemistry

    International Nuclear Information System (INIS)

    Colmenares, C.A.

    1975-01-01

    A course designed to provide communications between the designer of a system such as a mechanical engineer or a physicist and the material scientist such as a chemist or chemical engineer is presented. The topics discussed are stoichiometric principles, behavior of ideal gases, vapor pressure, humidity and saturation, solubility of gases in liquids, diffusion of gases, chemical reaction kinetics, and application of concepts to compatibility problems. The appendix provides problems to be used in conjunction with TV lectures

  9. Towards physical principles of biological evolution

    Science.gov (United States)

    Katsnelson, Mikhail I.; Wolf, Yuri I.; Koonin, Eugene V.

    2018-03-01

    Biological systems reach organizational complexity that far exceeds the complexity of any known inanimate objects. Biological entities undoubtedly obey the laws of quantum physics and statistical mechanics. However, is modern physics sufficient to adequately describe, model and explain the evolution of biological complexity? Detailed parallels have been drawn between statistical thermodynamics and the population-genetic theory of biological evolution. Based on these parallels, we outline new perspectives on biological innovation and major transitions in evolution, and introduce a biological equivalent of thermodynamic potential that reflects the innovation propensity of an evolving population. Deep analogies have been suggested to also exist between the properties of biological entities and processes, and those of frustrated states in physics, such as glasses. Such systems are characterized by frustration whereby local state with minimal free energy conflict with the global minimum, resulting in ‘emergent phenomena’. We extend such analogies by examining frustration-type phenomena, such as conflicts between different levels of selection, in biological evolution. These frustration effects appear to drive the evolution of biological complexity. We further address evolution in multidimensional fitness landscapes from the point of view of percolation theory and suggest that percolation at level above the critical threshold dictates the tree-like evolution of complex organisms. Taken together, these multiple connections between fundamental processes in physics and biology imply that construction of a meaningful physical theory of biological evolution might not be a futile effort. However, it is unrealistic to expect that such a theory can be created in one scoop; if it ever comes to being, this can only happen through integration of multiple physical models of evolutionary processes. Furthermore, the existing framework of theoretical physics is unlikely to suffice

  10. Limited entropic uncertainty as new principle of quantum physics

    International Nuclear Information System (INIS)

    Ion, D.B.; Ion, M.L.

    2001-01-01

    The Uncertainty Principle (UP) of quantum mechanics discovered by Heisenberg, which constitute the corner-stone of quantum physics, asserts that: there is an irreducible lower bound on the uncertainty in the result of a simultaneous measurement of non-commuting observables. In order to avoid this state-dependence many authors proposed to use the information entropy as a measure of the uncertainty instead of above standard quantitative formulation of the Heisenberg uncertainty principle. In this paper the Principle of Limited Entropic Uncertainty (LEU-Principle), as a new principle in quantum physics, is proved. Then, consistent experimental tests of the LEU-principle, obtained by using the available 49 sets of the pion-nucleus phase shifts, are presented for both, extensive (q=1) and nonextensive (q=0.5 and q=2.0) cases. Some results obtained by the application of LEU-Principle to the diffraction phenomena are also discussed. The main results and conclusions of our paper can be summarized as follows: (i) We introduced a new principle in quantum physics namely the Principle of Limited Entropic Uncertainty (LEU-Principle). This new principle includes in a more general and exact form not only the old Heisenberg uncertainty principle but also introduce an upper limit on the magnitude of the uncertainty in the quantum physics. The LEU-Principle asserts that: 'there is an irreducible lower bound as well as an upper bound on the uncertainty in the result of a simultaneous measurement of non-commuting observables for any extensive and nonextensive (q ≥ 0) quantum systems'; (ii) Two important concrete realizations of the LEU-Principle are explicitly obtained in this paper, namely: (a) the LEU-inequalities for the quantum scattering of spinless particles and (b) the LEU-inequalities for the diffraction on single slit of width 2a. In particular from our general results, in the limit y → +1 we recover in an exact form all the results previously reported. In our paper an

  11. Orbital radiation imaging with various physical principles

    International Nuclear Information System (INIS)

    Takeda, Toru; Itai, Yuji

    2001-01-01

    This paper describes the characteristics of orbital radiation and authors' investigations on the high spatial resolution X ray-CT, fluorescence X ray-CT and phase-type X ray imaging. Orbital radiation is an X ray generated by relativistic electron bended by magnet in the synchrotron and possesses the high photon density/unit area (>100,000 times higher than that of the ordinary X ray generated by the tube) and broad energy spectrum, which make it possible to select the X ray with appropriate energy for the target. The high spatial resolution X-CT has the resolution of 0.05 mm in contrast to 0.5 mm of the ordinary X-CT and is used for the hard structure like tooth and bone. The CT images of rat lumbar vertebrae and artificial bone are presented. Fluorescence X-CT is utilized for detection of trace elements. Images of the thyroid are presented on iodine detection. Concerning the phase-type X-imaging, the principle using the X ray interferometer is described and actual phase-images of blood vessels and 3-demensional ones of metastatic colon cancer in the liver are given. Imaging with the orbital radiation can be a useful technique in the near future. (K.H.)

  12. The physical principles of XRF calibrations

    International Nuclear Information System (INIS)

    Fazey, P.

    1999-01-01

    Full text: XRF Control and calibration software has come a long way in recent years. Advances in the multiple regression software sophistication and speed of computers have provided an essential resource to the XRF analyst. Over recent years there has been a trend amongst some analysts to develop XRF calibrations based exclusively on the statistical information given by calibration software. Multiple regression statistics are designed for non-correlated data sets but give unpredictable results if there are significant correlations in the standards used. This is typical for calibrations weighted towards certified reference materials (CRM's) which, being natural materials, contain correlated concentrations. Purely statistical methods in calibration development have applicability only over very short concentration ranges and for materials whose composition varies little. Beyond these ranges, the calibration has the potential to be unstable and has been known to produce significant deviations in analysis of unknown samples. The statistical information generated during XRF calibrations can be a very useful tool when used in conjunction with knowledge of the physics behind the correction factors applied. The matrix coefficients represent physical absorption/enhancement effects within the sample and are not arbitrary numbers used to get a good fit to the calibration line. Inappropriate use of matrix factors and overlap factors can produce low RMS values but erroneous results in unknown samples. This talk will contain examples to demonstrate hazards with different calibration strategies and will include coverage of the following topics: physical effects occurring within the sample as a result of X-ray irradiation; use of multiple regression statistics and what role it plays in the calibration; calibration strategies using synthetic and CRM standards; determining appropriate theoretical and semi-empirical matrix corrections and line overlap factors. Copyright (1999

  13. The principle of least action history and physics

    CERN Document Server

    Rojo, Alberto

    2018-01-01

    The principle of least action originates in the idea that, if nature has a purpose, it should follow a minimum or critical path. This simple principle, and its variants and generalizations, applies to optics, mechanics, electromagnetism, relativity, and quantum mechanics, and provides an essential guide to understanding the beauty of physics. This unique text provides an accessible introduction to the action principle across these various fields of physics, and examines its history and fundamental role in science. It includes - with varying levels of mathematical sophistication - explanations from historical sources, discussion of classic papers, and original worked examples. The result is a story that is understandable to those with a modest mathematical background, as well as to researchers and students in physics and the history of physics.

  14. A Survey of Physical Principles Attempting to Define Quantum Mechanics

    Science.gov (United States)

    Oas, Gary; Acacio de Barros, J.

    Quantum mechanics, one of the most successful theories in the history of science, was created to account for physical systems not describable by classical physics. Though it is consistent with all experiments conducted thus far, many of its core concepts (amplitudes, global phases, etc.) can not be directly accessed and its interpretation is still the subject of intense debate, more than 100 years since it was introduced. So, a fundamental question is why this particular mathematical model is the one that nature chooses, if indeed it is the correct model. In the past two decades there has been a renewed effort to determine what physical or informational principles define quantum mechanics. In this chapter, recent attempts at establishing reasonable physical principles are reviewed and their degree of success is tabulated. An alternative approach using joint quasi-probability distributions is shown to provide a common basis of representing most of the proposed principles. It is argued that having a common representation of the principles can provide intuition and guidance to relate current principles or advance new principles. The current state of affairs, along with some alternative views are discussed.

  15. The physical principles of radiation protection

    International Nuclear Information System (INIS)

    Lokan, K.H.

    1982-01-01

    The production of ionising radiation from the naturally occurring radioactive decay chains is reviewed and mathematical expressions relating to secular equilibrium and the calculation of the activity of daughter products are introduced. The absorption of α, β and γ radiation is discussed from the point of view of the physical processes which occur, e.g. the photoelectric, Compton and pair production processes for γ-rays. Linear energy transfer (LET) and range-energy relationships are discussed for α and β particles. Units of measurement for ionising radiation, relative biological effectiveness, dose equivalence and quality factors for each type of radiation are reviewed. The behaviour and properties of radon, thoron and their daughter products are described, and the definition of the Working Level introduced

  16. Solid State Physics Principles and Modern Applications

    CERN Document Server

    Quinn, John J

    2009-01-01

    Intended for a two semester advanced undergraduate or graduate course in Solid State Physics, this treatment offers modern coverage of the theory and related experiments, including the group theoretical approach to band structures, Moessbauer recoil free fraction, semi-classical electron theory, magnetoconductivity, electron self-energy and Landau theory of Fermi liquid, and both quantum and fractional quantum Hall effects. Integrated throughout are developments from the newest semiconductor devices, e.g. space charge layers, quantum wells and superlattices. The first half includes all material usually covered in the introductory course, but in greater depth than most introductory textbooks. The second half includes most of the important developments in solid-state researches of the past half century, addressing e.g. optical and electronic properties such as collective bulk and surface modes and spectral function of a quasiparticle, which is a basic concept for understanding LEED intensities, X ray fine struc...

  17. The physical principles of radiation protection

    International Nuclear Information System (INIS)

    Lokan, K.H.

    1990-01-01

    This lecture reviews the production of ionising radiation from the naturally occurring radioactive decay chains and introduces the mathematical expressions relating to secular equilibrium and the calculation of the activity of daughter products. The absorption of α, β and γ radiation is discussed from the point of view of the physical processes which occur, e.g. the photoelectric, Compton and pair production processes for γ-rays. Linear energy transfer and range-energy relationships are discussed for α and β particles. Units of measurement for ionising radiation, relative biological effectiveness, dose equivalence and quality factors for each type of radiation are reviewed. the behaviour and properties of radon, thoron and their daughter products are described, and units used in the assessments of effective dose from radon daughters are discussed. 16 refs., 1 tab., 15 figs

  18. Epitaxy physical principles and technical implementation

    CERN Document Server

    Herman, Marian A; Sitter, Helmut

    2004-01-01

    Epitaxy provides readers with a comprehensive treatment of the modern models and modifications of epitaxy, together with the relevant experimental and technological framework. This advanced textbook describes all important aspects of the epitaxial growth processes of solid films on crystalline substrates, including a section on heteroepitaxy. It covers and discusses in details the most important epitaxial growth techniques, which are currently widely used in basic research as well as in manufacturing processes of devices, namely solid-phase epitaxy, liquid-phase epitaxy, vapor-phase epitaxy, including metal-organic vapor-phase epitaxy and molecular-beam epitaxy. Epitaxy’s coverage of science and texhnology thin-film is intended to fill the need for a comprehensive reference and text examining the variety of problems related to the physical foundations and technical implementation of epitaxial crystallization. It is intended for undergraduate students, PhD students, research scientists, lecturers and practic...

  19. The quantum beat the physical principles of atomic clocks

    CERN Document Server

    Major, F G

    1998-01-01

    One of the indicators of the level of technological development of a society has been, throughout history, the precision of clocks it was able to build. This book examines the physical principles underlying the workings of clocks--from the earliest mechanical clocks to the present-day sophisticated clocks based on the properties of individual atoms. Intended for non-specialists with some knowledge of physics or engineering,the book treats the material in a broad intuitive manner, with a minimum of mathematical formalism. The presentation covers a broad range of salient topics relevant to the measurement of frequency and time intervals. The main focus is on electronic time-keeping: clocks based on quartz crystal oscillators and, at greater length, atomic clocks based on quantum resonance in rubidium, cesium, and hydrogen atoms, and, more recently, mercury ions. The book treats the revolutionary changes that the optical laser has wrought on atomic standards through laser cooling and optical pumping, and it disc...

  20. Investigating underlying principles to guide health impact assessment.

    Science.gov (United States)

    Fakhri, Ali; Maleki, Mohammadreza; Gohari, Mahmoodreza; Harris, Patrick

    2014-06-01

    Many countries conduct Health Impact Assessment (HIA) of their projects and policies to predict their positive and negative health impacts. In recent years many guides have been developed to inform HIA practice, largely reflecting local developments in HIA. These guides have often been designed for specific contexts and specific need, making the choice between guides difficult. The objective of the current study is to identify underlying principles in order to guide HIA practice in Iran. This study was conducted in three stages: 1) Studies comparing HIA guidelines were reviewed to identify criteria used for comparison seeking emphasized principles. 2) The HIA characteristics extracted from published papers were categorized in order to determine the principles that could guide HIA practice. 3) Finally, these principles were agreed by experts using nominal group technique. The review of the studies comparing HIA guides demonstrated there are no clear comparison criteria for reviewing HIA guides and no study mentioned HIA principles. Investigating the HIA principles from peer-reviewed papers, we found 14 issues. These were, considering of general features in planning and conducting HIAs such as HIA stream, level, timing and type, considering of the wider socio-political and economic context, considering of economic, technical and legal aspects of HIA and capacities for HIA, rationality and comprehensiveness, using appropriate evidence, elaborating on HIA relation to other forms of Impact Assessment, considering of equity, and encouraging intersectoral and interdisciplinary cooperation, involvement of stakeholders and transparency as underlying principles to guide HIA practice. The results emphasize how critical these technical as well as tactical considerations are in the early scoping step of an HIA which plans the conduct of the HIA in reponse to local contextual issues. Determining the principles of HIA from peer-reviewed papers provides an opportunity for guiding

  1. Investigating Underlying Principles to Guide Health Impact Assessment

    Directory of Open Access Journals (Sweden)

    Ali Fakhri

    2014-06-01

    Full Text Available Background Many countries conduct Health Impact Assessment (HIA of their projects and policies to predict their positive and negative health impacts. In recent years many guides have been developed to inform HIA practice, largely reflecting local developments in HIA. These guides have often been designed for specific contexts and specific need, making the choice between guides difficult. The objective of the current study is to identify underlying principles in order to guide HIA practice in Iran. Methods This study was conducted in three stages: 1 Studies comparing HIA guidelines were reviewed to identify criteria used for comparison seeking emphasized principles. 2 The HIA characteristics extracted from published papers were categorized in order to determine the principles that could guide HIA practice. 3 Finally, these principles were agreed by experts using nominal group technique. Results The review of the studies comparing HIA guides demonstrated there are no clear comparison criteria for reviewing HIA guides and no study mentioned HIA principles. Investigating the HIA principles from peer-reviewed papers, we found 14 issues. These were, considering of general features in planning and conducting HIAs such as HIA stream, level, timing and type, considering of the wider socio-political and economic context, considering of economic, technical and legal aspects of HIA and capacities for HIA, rationality and comprehensiveness, using appropriate evidence, elaborating on HIA relation to other forms of Impact Assessment, considering of equity, and encouraging intersectoral and interdisciplinary cooperation, involvement of stakeholders and transparency as underlying principles to guide HIA practice. The results emphasize how critical these technical as well as tactical considerations are in the early scoping step of an HIA which plans the conduct of the HIA in reponse to local contextual issues. Conclusion Determining the principles of HIA from

  2. The principle of finiteness – a guideline for physical laws

    International Nuclear Information System (INIS)

    Sternlieb, Abraham

    2013-01-01

    I propose a new principle in physics-the principle of finiteness (FP). It stems from the definition of physics as a science that deals with measurable dimensional physical quantities. Since measurement results including their errors, are always finite, FP postulates that the mathematical formulation of legitimate laws in physics should prevent exactly zero or infinite solutions. I propose finiteness as a postulate, as opposed to a statement whose validity has to be corroborated by, or derived theoretically or experimentally from other facts, theories or principles. Some consequences of FP are discussed, first in general, and then more specifically in the fields of special relativity, quantum mechanics, and quantum gravity. The corrected Lorentz transformations include an additional translation term depending on the minimum length epsilon. The relativistic gamma is replaced by a corrected gamma, that is finite for v=c. To comply with FP, physical laws should include the relevant extremum finite values in their mathematical formulation. An important prediction of FP is that there is a maximum attainable relativistic mass/energy which is the same for all subatomic particles, meaning that there is a maximum theoretical value for cosmic rays energy. The Generalized Uncertainty Principle required by Quantum Gravity is actually a necessary consequence of FP at Planck's scale. Therefore, FP may possibly contribute to the axiomatic foundation of Quantum Gravity.

  3. Physical principles of filamentous protein self-assembly kinetics

    International Nuclear Information System (INIS)

    Michaels, Thomas C T; Liu, Lucie X; Meisl, Georg; Knowles, Tuomas P J

    2017-01-01

    The polymerization of proteins and peptides into filamentous supramolecular structures is an elementary form of self-organization of key importance to the functioning biological systems, as in the case of actin biofilaments that compose the cellular cytoskeleton. Aberrant filamentous protein self-assembly, however, is associated with undesired effects and severe clinical disorders, such as Alzheimer’s and Parkinson’s diseases, which, at the molecular level, are associated with the formation of certain forms of filamentous protein aggregates known as amyloids. Moreover, due to their unique physicochemical properties, protein filaments are finding extensive applications as biomaterials for nanotechnology. With all these different factors at play, the field of filamentous protein self-assembly has experienced tremendous activity in recent years. A key question in this area has been to elucidate the microscopic mechanisms through which filamentous aggregates emerge from dispersed proteins with the goal of uncovering the underlying physical principles. With the latest developments in the mathematical modeling of protein aggregation kinetics as well as the improvement of the available experimental techniques it is now possible to tackle many of these complex systems and carry out detailed analyses of the underlying microscopic steps involved in protein filament formation. In this paper, we review some classical and modern kinetic theories of protein filament formation, highlighting their use as a general strategy for quantifying the molecular-level mechanisms and transition states involved in these processes. (topical review)

  4. The beauty of physics patterns, principles, and perspectives

    CERN Document Server

    Rau, A R P

    2014-01-01

    The beauty of physics lies in its coherence in terms of a few fundamental concepts and principles. Even physicists have occasion to marvel at the overarching reach of basic principles and their ability to account for features stretching from the microscopic sub-atomic world to the cosmological expanses of the Universe. While mathematics is its natural language, physics is mostly about patterns, connections, and relations between objects and phenomena, and it is this aspect that is emphasized in this book. Since science tries to connect phenomena that at first sight appear widely different, while boiling them down to a small set of essential principles and laws, metaphor and analogy pervade our subject. Consider the pendulum, its swing from one extreme to the other often invoked in social or economic contexts. In molecular vibrations, such as in the CO2 molecule, the quantum motions of electrons and nuclei are metaphorically the pendulums. In electromagnetic radiation, including the visible light we observe, t...

  5. Using Physics Principles in the Teaching of Chemistry.

    Science.gov (United States)

    Gulden, Warren

    1996-01-01

    Presents three examples that show how students can use traditional physics principles or laws for the purpose of understanding chemistry better. Examples include Coulomb's Law and melting points, the Faraday Constant, and the Rydberg Constant. Presents a list of some other traditional topics in a chemistry course that could be enhanced by the…

  6. Relativistic nuclear physics: symmetry and the correlation depletion principle

    International Nuclear Information System (INIS)

    Baldin, A.M.

    1996-01-01

    The author's view on the role of symmetry in fundamental physics is presented. The concept of the 'symmetry of solutions' is analyzed. It is stressed that it is impossible to deduce the basic laws of relativistic nuclear physics from the QCD Lagrangians without recourse to additional hypotheses about the symmetry of solutions (Green functions). The test of these hypotheses is the major prospect of the study of hadron and nuclear collisions. Special importance is given to the Correlation Depletions Principle that makes it possible to construct mathematical models of relativistic nuclear physics, and analyze, by using simple terms, topologically complicated events of nucleus-nucleus collisions. 15 refs., 4 figs

  7. Separation and sorting of cells in microsystems using physical principles

    Science.gov (United States)

    Lee, Gi-Hun; Kim, Sung-Hwan; Ahn, Kihoon; Lee, Sang-Hoon; Park, Joong Yull

    2016-01-01

    In the last decade, microfabrication techniques have been combined with microfluidics and applied to cell biology. Utilizing such new techniques, various cell studies have been performed for the research of stem cells, immune cells, cancer, neurons, etc. Among the various biological applications of microtechnology-based platforms, cell separation technology has been highly regarded in biological and clinical fields for sorting different types of cells, finding circulating tumor cells (CTCs), and blood cell separation, amongst other things. Many cell separation methods have been created using various physical principles. Representatively, these include hydrodynamic, acoustic, dielectrophoretic, magnetic, optical, and filtering methods. In this review, each of these methods will be introduced, and their physical principles and sample applications described. Each physical principle has its own advantages and disadvantages. The engineers who design the systems and the biologists who use them should understand the pros and cons of each method or principle, to broaden the use of microsystems for cell separation. Continuous development of microsystems for cell separation will lead to new opportunities for diagnosing CTCs and cancer metastasis, as well as other elements in the bloodstream.

  8. Gauge theories under incorporation of a generalized uncertainty principle

    International Nuclear Information System (INIS)

    Kober, Martin

    2010-01-01

    There is considered an extension of gauge theories according to the assumption of a generalized uncertainty principle which implies a minimal length scale. A modification of the usual uncertainty principle implies an extended shape of matter field equations like the Dirac equation. If there is postulated invariance of such a generalized field equation under local gauge transformations, the usual covariant derivative containing the gauge potential has to be replaced by a generalized covariant derivative. This leads to a generalized interaction between the matter field and the gauge field as well as to an additional self-interaction of the gauge field. Since the existence of a minimal length scale seems to be a necessary assumption of any consistent quantum theory of gravity, the gauge principle is a constitutive ingredient of the standard model, and even gravity can be described as gauge theory of local translations or Lorentz transformations, the presented extension of gauge theories appears as a very important consideration.

  9. Perfect Form: Variational Principles, Methods, and Applications in Elementary Physics

    International Nuclear Information System (INIS)

    Isenberg, C

    1997-01-01

    This short book is concerned with the physical applications of variational principles of the calculus. It is intended for undergraduate students who have taken some introductory lectures on the subject and have been exposed to Lagrangian and Hamiltonian mechanics. Throughout the book the author emphasizes the historical background to the subject and provides numerous problems, mainly from the fields of mechanics and optics. Some of these problems are provided with an answer, while others, regretfully, are not. It would have been an added help to the undergraduate reader if complete solutions could have been provided in an appendix. The introductory chapter is concerned with Fermat's Principle and image formation. This is followed by the derivation of the Euler - Lagrange equation. The third chapter returns to the subject of optical paths without making the link with a mechanical variational principle - that comes later. Chapters on the subjects of minimum potential energy, least action and Hamilton's principle follow. This volume provides an 'easy read' for a student keen to learn more about the subject. It is well illustrated and will make a useful addition to all undergraduate physics libraries. (book review)

  10. Low dimensional physics and gauge principles : Matinyan Festschrift

    CERN Document Server

    Klümper, Andreas; Sedrakyan, A G

    2013-01-01

    This is a collection of articles on fundamental physical principles and methods, the topics ranging from matrix models, random surfaces, quantum dots and rings, to black holes, cosmology and testing of the tiny effects predicted by General Relativity. Among the authors are Sir Roger Penrose and other well-known experts and the articles are addressed to graduate students and researchers. The volume is a Festschrift to a noted physicist and mentor Sergei Matinyan.

  11. Design principles and developmental mechanisms underlying retinal mosaics.

    Science.gov (United States)

    Reese, Benjamin E; Keeley, Patrick W

    2015-08-01

    Most structures within the central nervous system (CNS) are composed of different types of neuron that vary in both number and morphology, but relatively little is known about the interplay between these two features, i.e. about the population dynamics of a given cell type. How such arrays of neurons are distributed within a structure, and how they differentiate their dendrites relative to each other, are issues that have recently drawn attention in the invertebrate nervous system, where the genetic and molecular underpinnings of these organizing principles are being revealed in exquisite detail. The retina is one of the few locations where these principles have been extensively studied in the vertebrate CNS, indeed, where the design principles of 'mosaic regularity' and 'uniformity of coverage' were first explicitly defined, quantified, and related to each other. Recent studies have revealed a number of genes that influence the formation of these histotypical features in the retina, including homologues of those invertebrate genes, although close inspection reveals that they do not always mediate comparable developmental processes nor elucidate fundamental design principles. The present review considers just how pervasive these features of 'mosaic regularity' and 'uniform dendritic coverage' are within the mammalian retina, discussing the means by which such features can be assessed in the mature and developing nervous system and examining the limitations associated with those assessments. We then address the extent to which these two design principles co-exist within different populations of neurons, and how they are achieved during development. Finally, we consider the neural phenotypes obtained in mutant nervous systems, to address whether a prospective gene of interest underlies those very design principles. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

  12. Principles of physics from quantum field theory to classical mechanics

    CERN Document Server

    Jun, Ni

    2014-01-01

    This book starts from a set of common basic principles to establish the formalisms in all areas of fundamental physics, including quantum field theory, quantum mechanics, statistical mechanics, thermodynamics, general relativity, electromagnetic field, and classical mechanics. Instead of the traditional pedagogic way, the author arranges the subjects and formalisms in a logical-sequential way, i.e. all the formulas are derived from the formulas before them. The formalisms are also kept self-contained. Most of the required mathematical tools are also given in the appendices. Although this book covers all the disciplines of fundamental physics, the book is concise and can be treated as an integrated entity. This is consistent with the aphorism that simplicity is beauty, unification is beauty, and thus physics is beauty. The book may be used as an advanced textbook by graduate students. It is also suitable for physicists who wish to have an overview of fundamental physics. Readership: This is an advanced gradua...

  13. Principle of minimum distance in space of states as new principle in quantum physics

    International Nuclear Information System (INIS)

    Ion, D. B.; Ion, M. L. D.

    2007-01-01

    The mathematician Leonhard Euler (1707-1783) appears to have been a philosophical optimist having written: 'Since the fabric of universe is the most perfect and is the work of the most wise Creator, nothing whatsoever take place in this universe in which some relation of maximum or minimum does not appear. Wherefore, there is absolutely no doubt that every effect in universe can be explained as satisfactory from final causes themselves the aid of the method of Maxima and Minima, as can from the effective causes'. Having in mind this kind of optimism in the papers mentioned in this work we introduced and investigated the possibility to construct a predictive analytic theory of the elementary particle interaction based on the principle of minimum distance in the space of quantum states (PMD-SQS). So, choosing the partial transition amplitudes as the system variational variables and the distance in the space of the quantum states as a measure of the system effectiveness, we obtained the results presented in this paper. These results proved that the principle of minimum distance in space of quantum states (PMD-SQS) can be chosen as variational principle by which we can find the analytic expressions of the partial transition amplitudes. In this paper we present a description of hadron-hadron scattering via principle of minimum distance PMD-SQS when the distance in space of states is minimized with two directional constraints: dσ/dΩ(±1) = fixed. Then by using the available experimental (pion-nucleon and kaon-nucleon) phase shifts we obtained not only consistent experimental tests of the PMD-SQS optimality, but also strong experimental evidences for new principles in hadronic physics such as: Principle of nonextensivity conjugation via the Riesz-Thorin relation (1/2p + 1/2q = 1) and a new Principle of limited uncertainty in nonextensive quantum physics. The strong experimental evidence obtained here for the nonextensive statistical behavior of the [J,

  14. Dual-Energy Computed Tomography: Physical Principles, Approaches to Scanning, Usage, and Implementation: Part 1.

    Science.gov (United States)

    Forghani, Reza; De Man, Bruno; Gupta, Rajiv

    2017-08-01

    There are increasing applications of dual-energy computed tomography (CT), a type of spectral CT, in neuroradiology and head and neck imaging. In this 2-part review, the fundamental principles underlying spectral CT scanning and the major considerations in implementing this type of scanning in clinical practice are reviewed. In the first part of this 2-part review, the physical principles underlying spectral CT scanning are reviewed, followed by an overview of the different approaches for spectral CT scanning, including a discussion of the strengths and challenges encountered with each approach. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Microfluidics and nanofluidics handbook chemistry, physics, and life science principles

    CERN Document Server

    Mitra, Sushanta K

    2011-01-01

    The Microfluidics and Nanofluidics Handbook: Two-Volume Set comprehensively captures the cross-disciplinary breadth of the fields of micro- and nanofluidics, which encompass the biological sciences, chemistry, physics and engineering applications. To fill the knowledge gap between engineering and the basic sciences, the editors pulled together key individuals, well known in their respective areas, to author chapters that help graduate students, scientists, and practicing engineers understand the overall area of microfluidics and nanofluidics. Topics covered include Cell Lysis Techniques in Lab-on-a-Chip Technology Electrodics in Electrochemical Energy Conversion Systems: Microstructure and Pore-Scale Transport Microscale Gas Flow Dynamics and Molecular Models for Gas Flow and Heat Transfer Microscopic Hemorheology and Hemodynamics Covering physics and transport phenomena along with life sciences and related applications, Volume One: Chemistry, Physics, and Life Science Principles provides readers with the fun...

  16. The epidemiologic principles underlying traffic safety study designs.

    Science.gov (United States)

    Kim, June H; Mooney, Stephen J

    2016-10-01

    This article describes the epidemiological principles underlying four observational study designs commonly used to assess traffic safety: the case-control, case-crossover, culpability and quasi-induced exposure designs. We focus in particular on the specific challenges for preventing bias using each design. Whereas recruiting controls representative of the source population poses a special challenge in case-control traffic safety studies, case-crossover designs are prone to recall bias, and culpability and quasi-induced exposure studies can be undermined by difficulties assigning crash responsibility. Using causal diagrams and worked examples, we provide a simple way to teach traffic safety designs to epidemiologists and to encourage proper application of epidemiological principles among researchers designing traffic safety studies. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  17. Physical principles for DNA tile self-assembly.

    Science.gov (United States)

    Evans, Constantine G; Winfree, Erik

    2017-06-19

    DNA tiles provide a promising technique for assembling structures with nanoscale resolution through self-assembly by basic interactions rather than top-down assembly of individual structures. Tile systems can be programmed to grow based on logical rules, allowing for a small number of tile types to assemble large, complex assemblies that can retain nanoscale resolution. Such algorithmic systems can even assemble different structures using the same tiles, based on inputs that seed the growth. While programming and theoretical analysis of tile self-assembly often makes use of abstract logical models of growth, experimentally implemented systems are governed by nanoscale physical processes that can lead to very different behavior, more accurately modeled by taking into account the thermodynamics and kinetics of tile attachment and detachment in solution. This review discusses the relationships between more abstract and more physically realistic tile assembly models. A central concern is how consideration of model differences enables the design of tile systems that robustly exhibit the desired abstract behavior in realistic physical models and in experimental implementations. Conversely, we identify situations where self-assembly in abstract models can not be well-approximated by physically realistic models, putting constraints on physical relevance of the abstract models. To facilitate the discussion, we introduce a unified model of tile self-assembly that clarifies the relationships between several well-studied models in the literature. Throughout, we highlight open questions regarding the physical principles for DNA tile self-assembly.

  18. Biological and Physical Principles in Self-Organization of Brain

    Science.gov (United States)

    Kröger, H.

    2007-04-01

    Complexity is a widespread phenomenon in nature. The brain is a foremost example of complexity. We address the question: How does such complexity emerge in brain? Which are the biological, chemical or physical principles at work which organize the formation of complixity? In particular we address the topics (i) adaptive learning, (ii) neuron cell death and pruning of synaptic connection afterbirth, (iii) small world and scale free architecture of neural connectivity, (iv) feature maps and the Kohonen model, (v) self-organized criticality and 1/f frequency scaling.

  19. Magnetic resonance angiography: Physical principles and clinical applications

    International Nuclear Information System (INIS)

    Hausmann, R.; Mueller, E.

    1992-01-01

    Within the last four years magnetic resonance angiography (MRA) developed very rapidly towards a well accepted screening technique for vascular examinations as a fast add-on to conventional MR. This review describes the basic physical principles as well as the different methods like time-of-flight and phase-sensitive MRA for visualization of blood vessels. Different applications of 3D, 2D sequential and 3D multivolume MRA are shown from various regions of the head and body. A short outlock to quantitative flow measurments is given in the last chapter including some interesting applications of these techniques which show the still expanding potential of magnetic resonance. (orig.) [de

  20. Polymer electrolyte fuel cells physical principles of materials and operation

    CERN Document Server

    Eikerling, Michael

    2014-01-01

    The book provides a systematic and profound account of scientific challenges in fuel cell research. The introductory chapters bring readers up to date on the urgency and implications of the global energy challenge, the prospects of electrochemical energy conversion technologies, and the thermodynamic and electrochemical principles underlying the operation of polymer electrolyte fuel cells. The book then presents the scientific challenges in fuel cell research as a systematic account of distinct components, length scales, physicochemical processes, and scientific disciplines. The main part of t

  1. Interweaving the Principle of Least Potential Energy in School and Introductory University Physics Courses

    Directory of Open Access Journals (Sweden)

    Yuval Ben-Abu

    2017-03-01

    Full Text Available Understanding advanced physical phenomena such as vertically hanging elastic column, soap bubbles, crystals and cracks demands expressing and manipulating a system’s potential energy under equilibrium conditions. However, students at schools and universities are usually required to consider the forces acting on a system under equilibrium conditions, rather than taking into account its potential energy. As a result, they find it difficult to express the system’s potential energy and use it for calculations when they do need to do so. The principle of least potential energy is a powerful idea for solving static equilibrium physics problems in various fields such as hydrostatics, mechanics, and electrostatics. In the current essay, the authors describe this principle and provide examples where students can apply it. For each problem, the authors provide both the force consideration solution approach and the energy consideration solution approach.

  2. Physical principles of thermoluminescence and recent developments in its measurement

    International Nuclear Information System (INIS)

    Levy, P.W.

    1974-01-01

    The physical principles which are the basis of thermoluminescence techniques for dating and authenticating archaeological and fine art objects are described in non-technical terms. Included is a discussion of the interaction of alpha particles, beta rays, i.e., energetic electrons, and gamma rays with solids, particularly electron-hole ion pair formation, and the trapping of charges by crystal imperfections. Also described is the charge-release process induced by heating and the accompanying emission of luminescence resulting from charge recombination and retrapping. The basic procedure for dating and/or authenticating an artifact is described in a ''how it is done'' manner. Lastly, recently developed apparatus is described for simultaneously measuring luminescent light intensity and wavelength and sample temperature. Examples of studies made with this ''3-D'' apparatus are given and applications to dating and authenticating are described. (U.S.)

  3. 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.

  4. Organizing principles underlying microorganism's growth-robustness trade-off.

    Science.gov (United States)

    Bolli, Alessandro; Salvador, Armindo

    2014-10-01

    Growth Robustness Reciprocity (GRR) is an intriguing microbial manifestation: the impairment of microorganism's growth enhances their ability to resist acute stresses, and vice-versa. This is caused by regulatory interactions that determine higher expression of protection mechanisms in response to low growth rates. But because such regulatory mechanisms are species-specific, GRR must result from convergent evolution. Why does natural selection favor such an outcome? We used mathematical models of optimal cellular resource allocation to identify the general principles underlying GRR. Non-linear optimization allowed to predict allocation patterns of biosynthetic resources (ribosomes devoted to the synthesis of each cell component) that maximize growth. These models predict the down-regulation of stress defenses under high substrate availabilities and low stress levels. Under these conditions, stress tolerance ensues from growth-related damage dilution: the higher the substrate availability, the fastest the dilution of damaged proteins by newly synthesized proteins, the lower the accumulation of damaged components into the cell. In turn, under low substrate availability growth is too slow for effective damage dilution, and the expression of the defenses up to some optimal level then increases growth. As a consequence, slow-growing cells are pre-adapted to withstand acute stresses. Therefore, the observed negative correlation between growth and stress tolerance can be explained as a consequence of optimal resource allocation for maximal growth. We acknowledge fellowship SFRH/BPD/90065/2012 and grants PEst-C/SAU/LA0001/2013-2014 and FCOMP-01-0124-FEDER-020978 financed by FEDER through the "Programa Operacional Factores de Competitividade, COMPETE" and by national funds through "FCT, Fundação para a Ciência e a Tecnologia" (project PTDC/QUI-BIQ/119657/2010). Copyright © 2014. Published by Elsevier Inc.

  5. Applications of the maximum entropy principle in nuclear physics

    International Nuclear Information System (INIS)

    Froehner, F.H.

    1990-01-01

    Soon after the advent of information theory the principle of maximum entropy was recognized as furnishing the missing rationale for the familiar rules of classical thermodynamics. More recently it has also been applied successfully in nuclear physics. As an elementary example we derive a physically meaningful macroscopic description of the spectrum of neutrons emitted in nuclear fission, and compare the well known result with accurate data on 252 Cf. A second example, derivation of an expression for resonance-averaged cross sections for nuclear reactions like scattering or fission, is less trivial. Entropy maximization, constrained by given transmission coefficients, yields probability distributions for the R- and S-matrix elements, from which average cross sections can be calculated. If constrained only by the range of the spectrum of compound-nuclear levels it produces the Gaussian Orthogonal Ensemble (GOE) of Hamiltonian matrices that again yields expressions for average cross sections. Both avenues give practically the same numbers in spite of the quite different cross section formulae. These results were employed in a new model-aided evaluation of the 238 U neutron cross sections in the unresolved resonance region. (orig.) [de

  6. Ultra-high energy physics and standard basic principles

    Directory of Open Access Journals (Sweden)

    Gonzalez-Mestres Luis

    2014-04-01

    Full Text Available It has not yet been elucidated whether the observed flux suppression for ultra-high energy cosmic rays (UHECR at energies above ≃ 4 x 1019 eV is a signature of the Greisen-Zatsepin-Kuzmin (GZK cutoff or a consequence of other phenomena. In both cases, violations of the standard fundamental principles of Physics can be present and play a significant role. They can in particular modify cosmic-ray interactions, propagation or acceleration at very high energy. Thus, in a long-term program, UHECR data can hopefully be used to test relativity, quantum mechanics, energy and momentum conservation, vacuum properties... as well as the elementariness of standard particles. Data on cosmic rays at energies ≃ 1020 eV may also be sensitive to new physics generated well beyond Planck scale. A typical example is provided by the search for possible signatures of a Lorentz symmetry violation (LSV associated to a privileged local reference frame (the "vacuum rest frame", VRF. If a VRF exists, the internal structure of standard particles at ultra-high energy can undergo substantial modifications. Similarly, the conventional particle symmetries may cease to be valid at such energies instead of heading to a grand unification and the structure of vacuum may no longer be governed by standard quantum field theory. Then, the question whether the notion of Planck scale still makes sense clearly becomes relevant and the very grounds of Cosmology can undergo essential modifications. UHECR studies naturally interact with the interpretation of WMAP and Planck observations. Recent Planck data analyses tend to confirm the possible existence of a privileged space direction. If the observed phenomenon turns out to be a signature of the spinorial space-time (SST we suggested in 1996-97, then conventional Particle Physics may correspond to the local properties of standard matter at low enough energy and large enough distances. This would clearly strengthen the cosmological

  7. Maximizing children's physical activity using the LET US Play principles.

    Science.gov (United States)

    Brazendale, Keith; Chandler, Jessica L; Beets, Michael W; Weaver, Robert G; Beighle, Aaron; Huberty, Jennifer L; Moore, Justin B

    2015-07-01

    Staff in settings that care for children struggle to implement standards designed to promote moderate-to-vigorous physical activity (MVPA), suggesting a need for effective strategies to maximize the amount of time children spend in MVPA during scheduled PA opportunities. The purpose of this study was to compare the MVPA children accumulate during commonly played games delivered in their traditional format versus games modified according to the LET US Play principles. Children (K-5th) participated in 1-hour PA sessions delivered on non-consecutive days (summer 2014). Using a randomized, counterbalanced design, one of the six games was played for 20min using either traditional rules or LET US Play followed by the other strategy with a 10min break in between. Physical activity was measured via accelerometry. Repeated-measures, mixed-effects regression models were used to estimate differences in percent of time spent sedentary and in MVPA. A total of 267 children (age 7.5years, 43% female, 29% African American) participated in 50, 1-hour activity sessions. Games incorporating LET US Play elicited more MVPA from both boys and girls compared to the same games with traditional rules. For boys and girls, the largest MVPA difference occurred during tag games (+20.3%). The largest reduction in the percent of time sedentary occurred during tag games (boys -27.7%, girls -32.4%). Overall, the percentage of children meeting 50% time in MVPA increased in four games (+18.7% to +53.1%). LET US Play led to greater accumulation of MVPA for boys and girls, and can increase the percent of children attaining the 50% of time in MVPA standard. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Principles of physics in surgery: the laws of flow dynamics physics for surgeons - Part 1.

    Science.gov (United States)

    Srivastava, Anurag; Sood, Akshay; Joy, S Parijat; Woodcock, John

    2009-08-01

    In the field of medicine and surgery many principles of physics find numerous applications. In this article we have summarized some prominent applications of the laws of fluid mechanics and hydrodynamics in surgery. Poiseuille's law sets the limits of isovolaemic haemodilution, enumerates limiting factors during fluid resuscitation and is a guiding principle in surgery for vascular stenoses. The equation of continuity finds use in non-invasive measurement of blood flow. Bernoulli's theorem explains the formation of post-stenotic dilatation. Reynolds number explains the origin of murmurs, haemolysis and airflow disturbances. Various forms of oxygen therapy are a direct application of the gas laws. Doppler effect is used in ultrasonography to find the direction and velocity of blood flow. In this first part of a series of articles we describe some applications of the laws of hydrodynamics governing the flow of blood and other body fluids.

  9. Principles of Technology Student Achievement in Advanced Physics Measured by a Normed Physics Test.

    Science.gov (United States)

    Nicholson, James Alan

    1991-02-01

    The Principles of Technology (PT) curriculum, now in approximately 1,200 schools, has produced a profound change in the delivery of applied physics. If high school PT programs and traditional physics courses deliver comparable student outcomes, as some research suggests, the PT curriculum may find wider acceptance in vocational programs and postsecondary schools may have rationale for accepting PT as physics. This study measured PT student performance on an advanced physics test, after they have had one year (7 units) of PT. The 1988R version of the National Association of Physics Teachers and National Science Teachers Association physics test, with more than 7500 copies sold, was selected as the research instrument. This test covers advanced aspects of traditional high school physics. A secondary enquiry included an attempt to link PT teacher preparation and credentialing and/or PT site demographics to variation in PT student scores on the 1988R test. The 10 PT sites in this study were self-selected from the 29 PT field study schools, the most mature PT sites. The researcher determined, that the 1988R physics test lacked content validity for the PT students tested. The PT students tested had a composite mean score of 17.67 questions correct out of 80, (below the second percentile), not statistically different than a chance score. No differences were found between site mean scores. Interpretation of the results regarding the effect of teachers, or demographics was not justified. The value of PT to the vocational-technical programs that it was designed for was not measured, nor was the awarding of general science credit for PT completion. One year of the PT curriculum, at the sampled schools, has not prepared students in the advanced scientific aspects of traditional physics found on the 1988R examination. The primary implication is that educators should not expect year one PT to prepare students for classes or curricula that include traditional physics as a

  10. General principles underlying the decommissioning of nuclear facilities

    International Nuclear Information System (INIS)

    1988-03-01

    Previous statements on the use of the term 'decommissioning' by the International Atomic Energy Agency, the Atomic Energy Control Board, and the Advisory Committee on Nuclear Safety are reviewed, culminating in a particular definition for its use in this paper. Three decommissioning phases are identified and discussed, leading to eight general principles governing decommissioning including one related to financing

  11. Malaysian Secondary Physics Teachers' Perceptions towards the Teaching and Learning of Archimedes' Principle

    Science.gov (United States)

    Salleh, Khalijah Mohd; Abdullah, Abu Bakar Bin

    2008-05-01

    An explorative study was carried out to confirm Malaysian Physics teachers' perception that Archimedes' principle is a difficult topic for secondary level students. The interview method was used for data collection. The study sample was made of nine national secondary schools teachers from Miri, Sarawak. The data was analysed qualitatively using the Atlas-ti version 5.2 software. The findings of the study showed that i) Archimedes' principle as compared to Bernoulli's and Pascal's is the most difficult principle of hydrodynamics for students, ii) more time was given in the teaching and learning (TL) of Archimedes principle compared to the other two principles, iii) the major TL problems include conceptual understanding, application of physics principles and ideas, and lack of mathematical skills. These findings implicate the need to develop corresponding instructional materials and learning kits that can assist students' understanding of Archimedes' principle.

  12. Motion of the Earth's centre of mass. Physical principles

    Science.gov (United States)

    Kiryan, D. G.; Kiryan, G. V.

    2005-06-01

    It has been found that the residual (Chandler) motion of the Earth's rotation pole results from the forced translational motion of the Earth's rotation axis relative to the geographic axis. The Earth's rotation axis moves parallel to itself without changing the angle of inclination to the ecliptic plane. The translational motion of the Earth's axis of rotation is caused by the motion of the Earth's center of mass in the Earth's body in the range from 1 to 30 meters relative to the Earth's surface. The motion of the Earth's center of mass in space is due to the motion of the consistent inner core of the Earth in the liquid outer core under the action of the total (internal and external) gravitational field. Formulae for calculation of the trajectory of the Earth's centre of mass from astronomical observations are suggested. The comparison of our calculations and observational data on variations in the latitudes of places and acceleration of gravity has shown that they are in good agreement. Our model has been shown to adequately describe the physical process of motion of the Earth's centre of mass inside the Earth's body.

  13. Scattering theory in quantum mechanics. Physical principles and mathematical methods

    International Nuclear Information System (INIS)

    Amrein, W.O.; Jauch, J.M.; Sinha, K.B.

    1977-01-01

    A contemporary approach is given to the classical topics of physics. The purpose is to explain the basic physical concepts of quantum scattering theory, to develop the necessary mathematical tools for their description, to display the interrelation between the three methods (the Schroedinger equation solutions, stationary scattering theory, and time dependence) to derive the properties of various quantities of physical interest with mathematically rigorous methods

  14. Pedagogical Principles of Learning to Teach Meaningful Physical Education

    Science.gov (United States)

    Ní Chróinín, Déirdre; Fletcher, Tim; O'Sullivan, Mary

    2018-01-01

    Background: Concerns that current forms of physical education teacher education (PETE) are not adequately providing teachers with the tools necessary for working with the realities and challenges of teaching physical education in contemporary schools has led some scholars to advocate for an approach that prioritises meaningfulness in physical…

  15. Investigation of the blood behaviour and vascular diseases by using mathematical physic principles

    Science.gov (United States)

    Yardimci, Ahmet; Simsek, Buket

    2017-07-01

    In this paper we prepare a short survey for using of mathematical physic principles in blood flow and vascular diseases researches. The study of the behavior of blood flow in the blood vessels provides understanding on connection between flow and the development of dieseases such as atherosclerosis, thrombosis, aneurysms etc. and how the flow dynamics is changed under these conditions. Blood flow phenomena are often too complex that it would be possible to describe them entirely analytically, although simple models, such as Poiseuille model, can still provide some insight into blood flow. Blood is not an "ideal fluid" and energy is lost as flowing blood overcomes resistance. Resistance to blood flow is a function of viscosity, vessel radius, and vessel length. So, mathematical Physic principles are useful tools for blood flow research studies. Blood flow is a function of pressure gradient and resistance and resistance to flow can be estimates using Poiseuille's law. Reynold's number can be used to determine whether flow is laminar or turbulent.

  16. FInal Report: First Principles Modeling of Mechanisms Underlying Scintillator Non-Proportionality

    Energy Technology Data Exchange (ETDEWEB)

    Aberg, Daniel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sadigh, Babak [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zhou, Fei [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-01

    This final report presents work carried out on the project “First Principles Modeling of Mechanisms Underlying Scintillator Non-Proportionality” at Lawrence Livermore National Laboratory during 2013-2015. The scope of the work was to further the physical understanding of the microscopic mechanisms behind scintillator nonproportionality that effectively limits the achievable detector resolution. Thereby, crucial quantitative data for these processes as input to large-scale simulation codes has been provided. In particular, this project was divided into three tasks: (i) Quantum mechanical rates of non-radiative quenching, (ii) The thermodynamics of point defects and dopants, and (iii) Formation and migration of self-trapped polarons. The progress and results of each of these subtasks are detailed.

  17. Generalized Tellegen Principle and Physical Correctness of System Representations

    Directory of Open Access Journals (Sweden)

    Vaclav Cerny

    2006-06-01

    Full Text Available The paper deals with a new problem of physical correctness detection in the area of strictly causal system representations. The proposed approach to the problem solution is based on generalization of Tellegen's theorem well known from electrical engineering. Consequently, mathematically as well as physically correct results are obtained. Some known and often used system representation structures are discussed from the developed point of view as an addition.

  18. Fundamentals of many-body physics. Principles and methods

    International Nuclear Information System (INIS)

    Nolting, Wolfgang

    2009-01-01

    This textbook addresses the special physics of many-particle systems, especially those dominated by correlation effects. It develops modern methods to treat such systems and demonstrates their application through numerous appropriate exercises, mainly from the field of solid state physics. The book is written in a tutorial style appropriate for those who want to learn many-body theory and eventually to use this to do research work in this field. The exercises, together with full solutions for evaluating one's performance, help to deepen understanding of the main aspects of many-particle systems. (orig.)

  19. Principles of general relativity theory in terms of the present day physics

    International Nuclear Information System (INIS)

    Pervushin, V.N.

    1986-01-01

    A hystory of gradual unification of general relativity theory and quantum field theory on the basis of unified geometrical principles is detected. The gauge invariance principles became universal for construction of all physical theories. Quantum mechanics, electrodynamics and Einstein gravitation theory were used to form geometrical principles. Identity of inertial and gravitational masses is an experimental basis of the general relativity theory (GRT). It is shown that correct understanding of GRT bases is a developing process related to the development of the present physics and stimulating this development

  20. Physically based principles of cell adhesion mechanosensitivity in tissues

    International Nuclear Information System (INIS)

    Ladoux, Benoit; Nicolas, Alice

    2012-01-01

    The minimal structural unit that defines living organisms is a single cell. By proliferating and mechanically interacting with each other, cells can build complex organization such as tissues that ultimately organize into even more complex multicellular living organisms, such as mammals, composed of billions of single cells interacting with each other. As opposed to passive materials, living cells actively respond to the mechanical perturbations occurring in their environment. Tissue cell adhesion to its surrounding extracellular matrix or to neighbors is an example of a biological process that adapts to physical cues. The adhesion of tissue cells to their surrounding medium induces the generation of intracellular contraction forces whose amplitude adapts to the mechanical properties of the environment. In turn, solicitation of adhering cells with physical forces, such as blood flow shearing the layer of endothelial cells in the lumen of arteries, reinforces cell adhesion and impacts cell contractility. In biological terms, the sensing of physical signals is transduced into biochemical signaling events that guide cellular responses such as cell differentiation, cell growth and cell death. Regarding the biological and developmental consequences of cell adaptation to mechanical perturbations, understanding mechanotransduction in tissue cell adhesion appears as an important step in numerous fields of biology, such as cancer, regenerative medicine or tissue bioengineering for instance. Physicists were first tempted to view cell adhesion as the wetting transition of a soft bag having a complex, adhesive interaction with the surface. But surprising responses of tissue cell adhesion to mechanical cues challenged this view. This, however, did not exclude that cell adhesion could be understood in physical terms. It meant that new models and descriptions had to be created specifically for these biological issues, and could not straightforwardly be adapted from dead matter

  1. Using spatial principles to optimize distributed computing for enabling the physical science discoveries.

    Science.gov (United States)

    Yang, Chaowei; Wu, Huayi; Huang, Qunying; Li, Zhenlong; Li, Jing

    2011-04-05

    Contemporary physical science studies rely on the effective analyses of geographically dispersed spatial data and simulations of physical phenomena. Single computers and generic high-end computing are not sufficient to process the data for complex physical science analysis and simulations, which can be successfully supported only through distributed computing, best optimized through the application of spatial principles. Spatial computing, the computing aspect of a spatial cyberinfrastructure, refers to a computing paradigm that utilizes spatial principles to optimize distributed computers to catalyze advancements in the physical sciences. Spatial principles govern the interactions between scientific parameters across space and time by providing the spatial connections and constraints to drive the progression of the phenomena. Therefore, spatial computing studies could better position us to leverage spatial principles in simulating physical phenomena and, by extension, advance the physical sciences. Using geospatial science as an example, this paper illustrates through three research examples how spatial computing could (i) enable data intensive science with efficient data/services search, access, and utilization, (ii) facilitate physical science studies with enabling high-performance computing capabilities, and (iii) empower scientists with multidimensional visualization tools to understand observations and simulations. The research examples demonstrate that spatial computing is of critical importance to design computing methods to catalyze physical science studies with better data access, phenomena simulation, and analytical visualization. We envision that spatial computing will become a core technology that drives fundamental physical science advancements in the 21st century.

  2. Inorganic scintillators for detector systems physical principles and crystal engineering

    CERN Document Server

    Lecoq, Paul; Korzhik, Mikhail

    2017-01-01

    This second edition features new chapters highlighting advances in our understanding of the behavior and properties of scintillators, and the discovery of new families of materials with light yield and excellent energy resolution very close to the theoretical limit. The book focuses on the discovery of next-generation scintillation materials and on a deeper understanding of fundamental processes. Such novel materials with high light yield as well as significant advances in crystal engineering offer exciting new perspectives. Most promising is the application of scintillators for precise time tagging of events, at the level of 100 ps or higher, heralding a new era in medical applications and particle physics. Since the discovery of the Higgs Boson with a clear signature in the lead tungstate scintillating blocks of the CMS Electromagnetic Calorimeter detector, the current trend in particle physics is toward very high luminosity colliders, in which timing performance will ultimately be essential to mitigating...

  3. Inorganic Scintillators for Detector Systems Physical Principles and Crystal Engineering

    CERN Document Server

    AUTHOR|(CDS)2068219; Gektin, Alexander; Korzhik, Mikhail; Pédrini, Christian

    2006-01-01

    The development of new scintillators as components of modern detector systems is increasingly defined by the end user's needs. This book provides an introduction to this emerging topic at the interface of physics and materials sciences, with emphasis on bulk inorganic scintillators. After surveying the end user's needs in a vast range of applications, ranging from astrophysics to industrial R & D, the authors move on to review scintillating mechanisms and the properties of the most important materials used. A chapter on crystal engineering and examples of recent developments in the field of high-energy physics and medical imaging introduce the reader to the practical aspects. This book will benefit researchers and scientists working in academic and industrial R & D related to the development of scintillators.

  4. Variational Principles and Methods in Theoretical Physics and Chemistry

    Science.gov (United States)

    Nesbet, Robert K.

    2005-07-01

    Preface; Part I. Classical Mathematics and Physics: 1. History of variational theory; 2. Classical mechanics; 3. Applied mathematics; Part II. Bound States in Quantum Mechanics: 4. Time-independent quantum mechanics; 5. Independent-electron models; 6. Time-dependent theory and linear response; Part III. Continuum States and Scattering Theory: 7. Multiple scattering theory for molecules and solids; 8. Variational methods for continuum states; 9. Electron-impact rovibrational excitation of molecules; Part IV. Field Theories: 10. Relativistic Lagrangian theories.

  5. Feeling force: physical and physiological principles enabling sensory mechanotransduction.

    Science.gov (United States)

    Katta, Samata; Krieg, Michael; Goodman, Miriam B

    2015-01-01

    Organisms as diverse as microbes, roundworms, insects, and mammals detect and respond to applied force. In animals, this ability depends on ionotropic force receptors, known as mechanoelectrical transduction (MeT) channels, that are expressed by specialized mechanoreceptor cells embedded in diverse tissues and distributed throughout the body. These cells mediate hearing, touch, and proprioception and play a crucial role in regulating organ function. Here, we attempt to integrate knowledge about the architecture of mechanoreceptor cells and their sensory organs with principles of cell mechanics, and we consider how engulfing tissues contribute to mechanical filtering. We address progress in the quest to identify the proteins that form MeT channels and to understand how these channels are gated. For clarity and convenience, we focus on sensory mechanobiology in nematodes, fruit flies, and mice. These themes are emphasized: asymmetric responses to applied forces, which may reflect anisotropy of the structure and mechanics of sensory mechanoreceptor cells, and proteins that function as MeT channels, which appear to have emerged many times through evolution.

  6. Applications of the principle of maximum entropy: from physics to ecology

    International Nuclear Information System (INIS)

    Banavar, Jayanth R; Volkov, Igor; Maritan, Amos

    2010-01-01

    There are numerous situations in physics and other disciplines which can be described at different levels of detail in terms of probability distributions. Such descriptions arise either intrinsically as in quantum mechanics, or because of the vast amount of details necessary for a complete description as, for example, in Brownian motion and in many-body systems. We show that an application of the principle of maximum entropy for estimating the underlying probability distribution can depend on the variables used for describing the system. The choice of characterization of the system carries with it implicit assumptions about fundamental attributes such as whether the system is classical or quantum mechanical or equivalently whether the individuals are distinguishable or indistinguishable. We show that the correct procedure entails the maximization of the relative entropy subject to known constraints and, additionally, requires knowledge of the behavior of the system in the absence of these constraints. We present an application of the principle of maximum entropy to understanding species diversity in ecology and introduce a new statistical ensemble corresponding to the distribution of a variable population of individuals into a set of species not defined a priori. (topical review)

  7. Physical principle for optimizing electrophoretic separation of charged particles

    Science.gov (United States)

    Araki, Takeaki; Tanaka, Hajime

    2008-04-01

    Electrophoresis is one of the most important methods for separating colloidal particles, carbohydrates, pharmaceuticals, and biological molecules such as DNA, RNA, proteins, in terms of their charge (or size). This method relies on the correlation between the particle drift velocity and the charge (or size). For a high-resolution separation, we need to minimize fluctuations of the drift velocity of particles or molecules. For a high throughput, on the other hand, we need a concentrated solution, in which many-body electrostatic and hydrodynamic interactions may increase velocity fluctuations. Thus, it is crucial to reveal what physical factors destabilize the coherent electrophoretic motion of charged particles. However, this is not an easy task due to complex dynamic couplings between particle motion, hydrodynamic flow, and motion of ion clouds. Here we study this fundamental problem using numerical simulations. We reveal that addition of salt screens both electrostatic and hydrodynamic interactions, but in a different manner. This allows us to minimize the fluctuations of the particle drift velocity for a particular salt concentration. This may have an impact not only on the basic physical understanding of dynamics of driven charged colloids, but also on the optimization of electrophoretic separation.

  8. Laser physics from principles to practical work in the lab

    CERN Document Server

    Eichhorn, Marc

    2014-01-01

    This textbook originates from a lecture course in laser physics at the Karlsruhe School of Optics and Photonics at the Karlsruhe Institute of Technology (KIT). A main goal in the conception of this textbook was to describe the fundamentals of lasers in a uniform and especially lab-oriented notation and formulation as well as many currently well-known laser types, becoming more and more important in the future. It closes a gap between the measureable spectroscopic quantities and the whole theoretical description and modeling. This textbook contains not only the fundamentals and the context of laser physics in a mathematical and methodical approach important for university-level studies. It allows simultaneously, owing to its conception and its modern notation, to directly implement and use the learned matter in the practical lab work. It is presented in a format suitable for everybody who wants not only to understand the fundamentals of lasers but also use modern lasers or even develop and make laser setups. T...

  9. Extreme Scale Computing for First-Principles Plasma Physics Research

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Choogn-Seock [Princeton University

    2011-10-12

    World superpowers are in the middle of the “Computnik” race. US Department of Energy (and National Nuclear Security Administration) wishes to launch exascale computer systems into the scientific (and national security) world by 2018. The objective is to solve important scientific problems and to predict the outcomes using the most fundamental scientific laws, which would not be possible otherwise. Being chosen into the next “frontier” group can be of great benefit to a scientific discipline. An extreme scale computer system requires different types of algorithms and programming philosophy from those we have been accustomed to. Only a handful of scientific codes are blessed to be capable of scalable usage of today’s largest computers in operation at petascale (using more than 100,000 cores concurrently). Fortunately, a few magnetic fusion codes are competing well in this race using the “first principles” gyrokinetic equations.These codes are beginning to study the fusion plasma dynamics in full-scale realistic diverted device geometry in natural nonlinear multiscale, including the large scale neoclassical and small scale turbulence physics, but excluding some ultra fast dynamics. In this talk, most of the above mentioned topics will be introduced at executive level. Representative properties of the extreme scale computers, modern programming exercises to take advantage of them, and different philosophies in the data flows and analyses will be presented. Examples of the multi-scale multi-physics scientific discoveries made possible by solving the gyrokinetic equations on extreme scale computers will be described. Future directions into “virtual tokamak experiments” will also be discussed.

  10. The fundamental principles of the physical protection, the group of six point of view

    International Nuclear Information System (INIS)

    Claeys, M.; Carnas, L.; Robeyns, G.; Rommevaux, G.; Venot, R.; Hagemann, A.; Fontaneda Gonzalez, A.; Gimenez Gonzalez, S.; Isaksson, S.G.; Wager, K.; Price, C.

    2001-01-01

    This paper presents the joint experience of the Group of Six in the field of physical protection against the theft or unauthorized removal of nuclear material and against the sabotage of nuclear material and nuclear facilities, which emerged from the joint discussion. Several fundamental principles stem from this experience. Of course the particular terms and conditions of the implementation of these principles are specific to each country. (authors)

  11. Quantum Physics Principles and Communication in the Acute Healthcare Setting: A Pilot Study.

    Science.gov (United States)

    Helgeson, Heidi L; Peyerl, Colleen Kraft; Solheim-Witt, Marit

    This pilot study explores whether clinician awareness of quantum physics principles could facilitate open communication between patients and providers. In the spirit of action research, this study was conceptualized with a holistic view of human health, using a mixed method design of grounded theory as an emergent method. Instrumentation includes surveys and a focus group discussion with twelve registered nurses working in an acute care hospital setting. Findings document that the preliminary core phenomenon, energy as information, influences communication in the healthcare environment. Key emergent themes include awareness, language, validation, open communication, strategies, coherence, incoherence and power. Research participants indicate that quantum physics principles provide a language and conceptual framework for improving their awareness of communication and interactions in the healthcare environment. Implications of this pilot study support the feasibility of future research and education on awareness of quantum physics principles in other clinical settings. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Demand of Insurance under the Cost-of-Capital Premium Calculation Principle

    Directory of Open Access Journals (Sweden)

    Michael Merz

    2014-06-01

    Full Text Available We study the optimal insurance design problem. This is a risk sharing problem between an insured and an insurer. The main novelty in this paper is that we study this optimization problem under a risk-adjusted premium calculation principle for the insurance cover. This risk-adjusted premium calculation principle uses the cost-of-capital approach as it is suggested (and used by the regulator and the insurance industry.

  13. Humanoid infers Archimedes' principle: understanding physical relations and object affordances through cumulative learning experiences.

    Science.gov (United States)

    Bhat, Ajaz Ahmad; Mohan, Vishwanathan; Sandini, Giulio; Morasso, Pietro

    2016-07-01

    Emerging studies indicate that several species such as corvids, apes and children solve 'The Crow and the Pitcher' task (from Aesop's Fables) in diverse conditions. Hidden beneath this fascinating paradigm is a fundamental question: by cumulatively interacting with different objects, how can an agent abstract the underlying cause-effect relations to predict and creatively exploit potential affordances of novel objects in the context of sought goals? Re-enacting this Aesop's Fable task on a humanoid within an open-ended 'learning-prediction-abstraction' loop, we address this problem and (i) present a brain-guided neural framework that emulates rapid one-shot encoding of ongoing experiences into a long-term memory and (ii) propose four task-agnostic learning rules (elimination, growth, uncertainty and status quo) that correlate predictions from remembered past experiences with the unfolding present situation to gradually abstract the underlying causal relations. Driven by the proposed architecture, the ensuing robot behaviours illustrated causal learning and anticipation similar to natural agents. Results further demonstrate that by cumulatively interacting with few objects, the predictions of the robot in case of novel objects converge close to the physical law, i.e. the Archimedes principle: this being independent of both the objects explored during learning and the order of their cumulative exploration. © 2016 The Author(s).

  14. The search for underlying principles of health impact assessment: progress and prospects: Comment on "Investigating underlying principles to guide health impact assessment".

    Science.gov (United States)

    Winkler, Mirko S; Utzinger, Jürg

    2014-07-01

    Health Impact Assessment (HIA) is a relatively young field of endeavour, and hence, future progress will depend on the planning, implementation and rigorous evaluation of additional HIAs of projects, programmes and policies the world over. In the June 2014 issue of the International Journal of Health Policy and Management, Fakhri and colleagues investigated underlying principles of HIA through a comprehensive review of the literature and expert consultation. With an emphasis on the Islamic Republic of Iran, the authors identified multiple issues that are relevant for guiding HIA practice. At the same time, the study unravelled current shortcomings in the understanding and definition of HIA principles and best practice at national, regional, and global levels. In this commentary we scrutinise the research presented, highlight strengths and limitations, and discuss the findings in the context of other recent attempts to guide HIA.

  15. The Search for Underlying Principles of Health Impact Assessment: Progress and Prospects; Comment on “Investigating Underlying Principles to Guide Health Impact Assessment”

    Directory of Open Access Journals (Sweden)

    Mirko S. Winkler

    2014-07-01

    Full Text Available Health Impact Assessment (HIA is a relatively young field of endeavour, and hence, future progress will depend on the planning, implementation and rigorous evaluation of additional HIAs of projects, programmes and policies the world over. In the June 2014 issue of the International Journal of Health Policy and Management, Fakhri and colleagues investigated underlying principles of HIA through a comprehensive review of the literature and expert consultation. With an emphasis on the Islamic Republic of Iran, the authors identified multiple issues that are relevant for guiding HIA practice. At the same time, the study unravelled current shortcomings in the understanding and definition of HIA principles and best practice at national, regional, and global levels. In this commentary we scrutinise the research presented, highlight strengths and limitations, and discuss the findings in the context of other recent attempts to guide HIA.

  16. Alzheimer's Disease as Subcellular `Cancer' --- The Scale-Invariant Principles Underlying the Mechanisms of Aging ---

    Science.gov (United States)

    Murase, M.

    1996-01-01

    with self-organization, has been thought to underlie `creative' aspects of biological phenomena such as the origin of life, adaptive evolution of viruses, immune recognition and brain function. It therefore must be surprising to find that the same principles will also underlie `non-creative' aspects, for example, the development of cancer and the aging of complex organisms. Although self-organization has extensively been studied in nonliving things such as chemical reactions and laser physics, it is undoubtedly true that the similar sources of the order are available to living things at different levels and scales. Several paradigm shifts are, however, required to realize how the general principles of natural selection can be extensible to non-DNA molecules which do not possess the intrinsic nature of self-reproduction. One of them is, from the traditional, genetic inheritance view that DNA (or RNA) molecules are the ultimate unit of heritable variations and natural selection at any organization level, to the epigenetic (nongenetic) inheritance view that any non-DNA molecule can be the target of heritable variations and molecular selection to accumulate in certain biochemical environment. Because they are all enriched with a β-sheet content, ready to mostly interact with one another, different denatured proteins like β-amyloid, PHF and prions can individually undergo self-templating or self-aggregating processes out of gene control. Other paradigm shifts requisite for a break-through in the etiology of neurodegenerative disorders will be discussed. As it is based on the scale-invariant principles, the present theory also predicts plausible mechanisms underlying quite different classes of disorders such as amyotrophic lateral sclerosis (ALS), atherosclerosis, senile cataract and many other symptoms of aging. The present theory, thus, provides the consistent and comprehensive account to the origin of aging by means of natural selection and self-organization.

  17. Didactic Principles in the Acquisition of Skills in the Practical Classes of Physical-Chemistry II

    Directory of Open Access Journals (Sweden)

    Plácida Miriam Salazar-Arrastre

    2016-04-01

    Full Text Available In this paper the experiences of teachers who teach the subject Physical Chemistry II, at the Faculty of Chemical Engineering at the University of East in the application of teaching principles in the development of practical classes of the course are exposed Physical Chemistry II, in order to properly develop in students the skills declared in the program itself.  It shows how considering the didactic principles discussed here during the development of the Practice Classes, ie emphasizing the correct structure that must have these, planning, and systematization including teaching principles, is possible developing their own skills and influence the course preparing students to face increasingly complex problem situations in later courses.Generalized Scheme of Activities (GSA of the subject, which help to develop logical thinking, look for the best solution algorithm and progressively strengthen the skills through these students are acquiring CP are presented.

  18. Two-dimensional models as testing ground for principles and concepts of local quantum physics

    Science.gov (United States)

    Schroer, Bert

    2006-02-01

    In the past two-dimensional models of QFT have served as theoretical laboratories for testing new concepts under mathematically controllable condition. In more recent times low-dimensional models (e.g., chiral models, factorizing models) often have been treated by special recipes in a way which sometimes led to a loss of unity of QFT. In the present work, I try to counteract this apartheid tendency by reviewing past results within the setting of the general principles of QFT. To this I add two new ideas: (1) a modular interpretation of the chiral model Diff( S)-covariance with a close connection to the recently formulated local covariance principle for QFT in curved spacetime and (2) a derivation of the chiral model temperature duality from a suitable operator formulation of the angular Wick rotation (in analogy to the Nelson-Symanzik duality in the Ostertwalder-Schrader setting) for rational chiral theories. The SL (2, Z) modular Verlinde relation is a special case of this thermal duality and (within the family of rational models) the matrix S appearing in the thermal duality relation becomes identified with the statistics character matrix S. The relevant angular "Euclideanization" is done in the setting of the Tomita-Takesaki modular formalism of operator algebras. I find it appropriate to dedicate this work to the memory of J.A. Swieca with whom I shared the interest in two-dimensional models as a testing ground for QFT for more than one decade. This is a significantly extended version of an "Encyclopedia of Mathematical Physics" contribution hep-th/0502125.

  19. Two-dimensional models as testing ground for principles and concepts of local quantum physics

    International Nuclear Information System (INIS)

    Schroer, Bert

    2005-04-01

    In the past two-dimensional models of QFT have served as theoretical laboratories for testing new concepts under mathematically controllable condition. In more recent times low-dimensional models (e.g. chiral models, factoring models) often have been treated by special recipes in a way which sometimes led to a loss of unity of QFT. In the present work I try to counteract this apartheid tendency by reviewing past results within the setting of the general principles of QFT. To this I add two new ideas: (1) a modular interpretation of the chiral model Diff(S)-covariance with a close connection to the recently formulated local covariance principle for QFT in curved spacetime and (2) a derivation of the chiral model temperature duality from a suitable operator formulation of the angular Wick rotation (in analogy to the Nelson-Symanzik duality in the Ostertwalder-Schrader setting) for rational chiral theories. The SL(2,Z) modular Verlinde relation is a special case of this thermal duality and (within the family of rational models) the matrix S appearing in the thermal duality relation becomes identified with the statistics character matrix S. The relevant angular 'Euclideanization' is done in the setting of the Tomita-Takesaki modular formalism of operator algebras. I find it appropriate to dedicate this work to the memory of J. A. Swieca with whom I shared the interest in two-dimensional models as a testing ground for QFT for more than one decade. This is a significantly extended version of an 'Encyclopedia of Mathematical Physics' contribution hep-th/0502125. (author)

  20. Two-dimensional models as testing ground for principles and concepts of local quantum physics

    International Nuclear Information System (INIS)

    Schroer, Bert

    2006-01-01

    In the past two-dimensional models of QFT have served as theoretical laboratories for testing new concepts under mathematically controllable condition. In more recent times low-dimensional models (e.g., chiral models, factorizing models) often have been treated by special recipes in a way which sometimes led to a loss of unity of QFT. In the present work, I try to counteract this apartheid tendency by reviewing past results within the setting of the general principles of QFT. To this I add two new ideas: (1) a modular interpretation of the chiral model Diff(S)-covariance with a close connection to the recently formulated local covariance principle for QFT in curved spacetime and (2) a derivation of the chiral model temperature duality from a suitable operator formulation of the angular Wick rotation (in analogy to the Nelson-Symanzik duality in the Ostertwalder-Schrader setting) for rational chiral theories. The SL (2, Z) modular Verlinde relation is a special case of this thermal duality and (within the family of rational models) the matrix S appearing in the thermal duality relation becomes identified with the statistics character matrix S. The relevant angular 'Euclideanization' is done in the setting of the Tomita-Takesaki modular formalism of operator algebras. I find it appropriate to dedicate this work to the memory of J.A. Swieca with whom I shared the interest in two-dimensional models as a testing ground for QFT for more than one decade. This is a significantly extended version of an 'Encyclopedia of Mathematical Physics' contribution hep-th/0502125

  1. Two-dimensional models as testing ground for principles and concepts of local quantum physics

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Bert [FU Berlin (Germany). Institut fuer Theoretische Physik

    2005-04-15

    In the past two-dimensional models of QFT have served as theoretical laboratories for testing new concepts under mathematically controllable condition. In more recent times low-dimensional models (e.g. chiral models, factoring models) often have been treated by special recipes in a way which sometimes led to a loss of unity of QFT. In the present work I try to counteract this apartheid tendency by reviewing past results within the setting of the general principles of QFT. To this I add two new ideas: (1) a modular interpretation of the chiral model Diff(S)-covariance with a close connection to the recently formulated local covariance principle for QFT in curved spacetime and (2) a derivation of the chiral model temperature duality from a suitable operator formulation of the angular Wick rotation (in analogy to the Nelson-Symanzik duality in the Ostertwalder-Schrader setting) for rational chiral theories. The SL(2,Z) modular Verlinde relation is a special case of this thermal duality and (within the family of rational models) the matrix S appearing in the thermal duality relation becomes identified with the statistics character matrix S. The relevant angular 'Euclideanization' is done in the setting of the Tomita-Takesaki modular formalism of operator algebras. I find it appropriate to dedicate this work to the memory of J. A. Swieca with whom I shared the interest in two-dimensional models as a testing ground for QFT for more than one decade. This is a significantly extended version of an 'Encyclopedia of Mathematical Physics' contribution hep-th/0502125. (author)

  2. Mathematical, physical and numerical principles essential for models of turbulent mixing

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, David Howland [Los Alamos National Laboratory; Lim, Hyunkyung [STONY BROOK UNIV; Yu, Yan [STONY BROOK UNIV; Glimm, James G [STONY BROOK UNIV

    2009-01-01

    We propose mathematical, physical and numerical principles which are important for the modeling of turbulent mixing, especially the classical and well studied Rayleigh-Taylor and Richtmyer-Meshkov instabilities which involve acceleration driven mixing of a fluid discontinuity layer, by a steady accerleration or an impulsive force.

  3. Physical Principles of the Method for Determination of Geometrical Characteristics and Particle Recognition in Digital Holography

    Science.gov (United States)

    Dyomin, V. V.; Polovtsev, I. G.; Davydova, A. Yu.

    2018-03-01

    The physical principles of a method for determination of geometrical characteristics of particles and particle recognition based on the concepts of digital holography, followed by processing of the particle images reconstructed from the digital hologram, using the morphological parameter are reported. An example of application of this method for fast plankton particle recognition is given.

  4. Physical properties of the tetragonal CuMnAs: A first-principles study

    Czech Academy of Sciences Publication Activity Database

    Máca, František; Kudrnovský, Josef; Drchal, Václav; Carva, K.; Baláž, P.; Turek, I.

    2017-01-01

    Roč. 96, č. 9 (2017), s. 1-8, č. článku 094406. ISSN 2469-9950 R&D Projects: GA ČR GB14-37427G Grant - others:GA MŠk(CZ) LM2015042 Institutional support: RVO:68378271 Keywords : first- principles calculations * defects * CuMnAs * transport properties Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.836, year: 2016

  5. Community-based physical activity intervention using principles of social marketing: a demonstration project in Southern India.

    Science.gov (United States)

    Subitha, L; Soudarssanane, M Bala; Murugesan, R

    2013-01-01

    We aimed to study the development and implementation of promotion of physical activity in a rural community by applying the principles of social marketing and to determine participation behaviour in a physical activity programme in a community setting. The intervention targeted 485 people, 20-49 years of age, residents of Periakattupalayam and Rangareddipalayam villages, Tamil Nadu. This community-based participatory research was based on the principles of 'social marketing'. Health education by one-to-one counselling, written materials and community events were used to popularize moderate intensity physical activity (brisk walking for 30 minutes on 4 days/week). We formed 30 walking groups under four coordinators, in a home-based setting with professional supervision and guidance. A log of physical activity sessions for the 10-week intervention period was maintained in the form of group attendance record. Village leaders, self-help groups and youth clubs were involved in promoting physical activity. Of the 485 subjects, 265 people (54.6%) engaged in brisk walking >4 days a week, while 156 subjects (32.2%) performed walking on 1-4 days per week during the intervention. The drop-out rate was 13.2% (64 subjects). Age, occupation and educational status were important determinants of participation and adherence to the physical activity programme. Application of social marketing techniques in an intervention to promote physical activity was successful in a rural Indian community. Studying the determinants of adoption of a physical activity programme and addressing the barriers to behaviour change are essential for designing relevant policies and effective programmes. Copyright 2012, NMJI.

  6. Temporal ventriloquism along the path of apparent motion: speed perception under different spatial grouping principles.

    Science.gov (United States)

    Ogulmus, Cansu; Karacaoglu, Merve; Kafaligonul, Hulusi

    2018-03-01

    The coordination of intramodal perceptual grouping and crossmodal interactions plays a critical role in constructing coherent multisensory percepts. However, the basic principles underlying such coordinating mechanisms still remain unclear. By taking advantage of an illusion called temporal ventriloquism and its influences on perceived speed, we investigated how audiovisual interactions in time are modulated by the spatial grouping principles of vision. In our experiments, we manipulated the spatial grouping principles of proximity, uniform connectedness, and similarity/common fate in apparent motion displays. Observers compared the speed of apparent motions across different sound timing conditions. Our results revealed that the effects of sound timing (i.e., temporal ventriloquism effects) on perceived speed also existed in visual displays containing more than one object and were modulated by different spatial grouping principles. In particular, uniform connectedness was found to modulate these audiovisual interactions in time. The effect of sound timing on perceived speed was smaller when horizontal connecting bars were introduced along the path of apparent motion. When the objects in each apparent motion frame were not connected or connected with vertical bars, the sound timing was more influential compared to the horizontal bar conditions. Overall, our findings here suggest that the effects of sound timing on perceived speed exist in different spatial configurations and can be modulated by certain intramodal spatial grouping principles such as uniform connectedness.

  7. Laboratory Experiments in Physics for Modern Astronomy With Comprehensive Development of the Physical Principles

    CERN Document Server

    Golden, Leslie

    2013-01-01

    This book presents experiments which will teach physics relevant to astronomy. The astronomer, as instructor, frequently faces this need when his college or university has no astronomy department and any astronomy course is taught in the physics department. The physicist, as instructor, will find this intellectually appealing when faced with teaching an introductory astronomy course. From these experiments, the student will acquire important analytical tools, learn physics appropriate to astronomy, and experience instrument calibration and the direct gathering and analysis of data. Experiments that can be performed in one laboratory session as well as semester-long observation projects are included. This textbook is aimed at undergraduate astronomy students.

  8. TEACHING PHYSICS: An experiment to demonstrate the principles and processes involved in medical Doppler ultrasound

    Science.gov (United States)

    Andrews, D. G. H.

    2000-09-01

    Doppler ultrasound is widely used in medicine for measuring blood velocity. This paper describes an experiment illustrating the principles of medical Doppler ultrasound. It is designed with A-level/undergraduate physics students in mind. Ultrasound is transmitted in air and reflected from a moving target. The return signal is processed using a series of modules, so that students can discover for themselves how each stage in the instrument works. They can also obtain a quantitative value of the speed of the target.

  9. Underlying Mechanisms of Improving Physical Activity Behavior after Rehabilitation

    NARCIS (Netherlands)

    van der Ploeg, Hidde P.; Streppel, Kitty R.M.; van der Beek, Allard J.; Woude, Luc H.V.; van Harten, Willem H.; Vollenbroek-Hutten, Miriam Marie Rosé; van Mechelen, Willem

    2008-01-01

    Background: Regular physical activity is beneficial for the health and functioning of people with a disability. Effective components of successful physical activity promotion interventions should be identified and disseminated. Purpose: To study the underlying mechanisms of the combined sport

  10. Testing principle working mechanisms of the health action process approach for subjective physical age groups.

    Science.gov (United States)

    Wienert, Julian; Kuhlmann, Tim; Fink, Sebastian; Hambrecht, Rainer; Lippke, Sonia

    2016-01-01

    This study investigated differences in social-cognitive predictors and self-regulatory planning, as proposed by the health action process approach (HAPA), across three different subjective physical age groups for physical activity. With a cross-sectional design, 521 participants across the chronological age span from 25 to 86 years (M = 48.79; SD = 12.66) were separated into three groups: those who feel physically younger than they are in terms of chronological age, the same perceived and chronological age, and feeling physically older compared to their chronological age. Participants were assessed regarding their perceived vulnerability, outcome expectancies, general intentions, planning, self-efficacy, and stages of physical activity (non-intenders, intenders, and actors). Data were analysed via mean comparison and multigroup structural equation modelling. Mean differences for all but one construct were eminent in all groups, generally showing that those feeling physically younger also report better social-cognitive predictors of physical activity (e.g. lower perceived vulnerability) in comparison to those who feel the same age or older. The model showed that basic working mechanisms of the HAPA can be applied to all groups. With that, the results provide for the first time evidence that principle working mechanism of the HAPA can be applied to all subjective physical age groups. These may be used to tailor health promoting interventions according to participants' needs as a more suitable proxy than chronological age.

  11. THE UNDERLYING PRINCIPLES OF SUSILO BAMBANG YUDHOYONO‘S THOUGHT PATTERNS IN HIS ENGLISH SPEECH TEXTS

    Directory of Open Access Journals (Sweden)

    Sulistya ningsih

    2014-10-01

    Full Text Available The underlying principles of thought patterns as shown in SBY's English Speeches Texts are made because there are different responses from the public, a part of public praise that SBY is a good president, and others claim and criticize him that  he is slow (Djalal, 2007: forward page. This title so far has not been investigated. This research was aimed at finding out:  the underlying principles of SBY’s thought patterns in his English Speech Texts related to Javanese philosophy. This research is qualitative. The data selected from SBY’s speech Texts were analyzed using semantic and pragmastylistic theory then were related to Javanese philosophy. The findings are the underlying principles of SBY’s thought patterns based on Javanese philosophy manifested in his English Speech Texts are: first is Memayu Hayuning Bawana, Ambrasta dur Hangkara means to reach safety, peace, happiness and well-being of the world and its contents, to keep the world maintained and harmony. Second, Rukun agawe santosa crah agawe bubrah  means to build the condition of harmony, and avoid conflict, because conflict can be harmful to both parties. Third, tepa selira means keep thinking not to offend others or lighten the burdens of others, tolerance. Fourth is ana rembug becik dirembug means thru negotiations can avoid conflict and achieve cooperation, safety, peace and prosperity. In sum, the world peace can be reached thru discussions without war, soft powers.

  12. The precautionary principle in fisheries management under climate change: How the international legal framework formulate it?

    Science.gov (United States)

    Latifah, E.; Imanullah, M. N.

    2018-03-01

    One of the objectives of fisheries management is to reach long-term sustainable benefits of the fish stocks while reducing the risk of severe or irreversible damage to the marine ecosystem. Achieving this objective needs, the good scientific knowledge and understanding on fisheries management including scientific data and information on the fish stock, fishing catch, distribution, migration, the proportion of mature fish, the mortality rate, reproduction as well as the knowledge on the impact of fishing on dependent and associated species and other species belonging to the same ecosystem, and further the impact of climate change and climate variability on the fish stocks and marine ecosystem. Lack of this scientific knowledge may lead to high levels of uncertainty. The precautionary principle is one of the basic environmental principles needed in overcoming this problem. An essence of this principle is that, in facing the serious risk as a result of the limited scientific knowledge or the absence of complete evidence of harm, it should not prevent the precautionary measures in minimizing risks and protecting the fish stocks and ecosystem. This study aims to examine how the precautionary principle in fisheries management be formulated into the international legal framework, especially under the climate change framework.

  13. Neutron Stars: Laboratories for Fundamental Physics Under ...

    Indian Academy of Sciences (India)

    DEBADES BANDYOPADHYAY

    2017-09-07

    Sep 7, 2017 ... American Physical Society in 1933, Baade & Zwicky ... of pulsars and black holes using the SKA and LIGO-. India along with other ..... a black hole. Different groups investigated the problem of stability of a PNS for short times. When a PNS is made up of nucleons and leptons, it has a slightly smaller max-.

  14. Precautionary principles: a jurisdiction-free framework for decision-making under risk.

    Science.gov (United States)

    Ricci, Paolo F; Cox, Louis A; MacDonald, Thomas R

    2004-12-01

    Fundamental principles of precaution are legal maxims that ask for preventive actions, perhaps as contingent interim measures while relevant information about causality and harm remains unavailable, to minimize the societal impact of potentially severe or irreversible outcomes. Such principles do not explain how to make choices or how to identify what is protective when incomplete and inconsistent scientific evidence of causation characterizes the potential hazards. Rather, they entrust lower jurisdictions, such as agencies or authorities, to make current decisions while recognizing that future information can contradict the scientific basis that supported the initial decision. After reviewing and synthesizing national and international legal aspects of precautionary principles, this paper addresses the key question: How can society manage potentially severe, irreversible or serious environmental outcomes when variability, uncertainty, and limited causal knowledge characterize their decision-making? A decision-analytic solution is outlined that focuses on risky decisions and accounts for prior states of information and scientific beliefs that can be updated as subsequent information becomes available. As a practical and established approach to causal reasoning and decision-making under risk, inherent to precautionary decision-making, these (Bayesian) methods help decision-makers and stakeholders because they formally account for probabilistic outcomes, new information, and are consistent and replicable. Rational choice of an action from among various alternatives--defined as a choice that makes preferred consequences more likely--requires accounting for costs, benefits and the change in risks associated with each candidate action. Decisions under any form of the precautionary principle reviewed must account for the contingent nature of scientific information, creating a link to the decision-analytic principle of expected value of information (VOI), to show the

  15. High-energy cosmic rays and tests of basic principles of Physics

    Directory of Open Access Journals (Sweden)

    Gonzalez-Mestres L.

    2014-04-01

    Full Text Available With the present understanding of data, the observed flux suppression for ultra-high energy cosmic rays (UHECR at energies above 4.1019 eV can be a signature of the Greisen-Zatsepin-Kuzmin (GZK cutoff or be related to a similar mechanism. But it may also correspond, for instance, to the maximum energies available at the relevant sources. In both cases, violations of special relativity modifying cosmic-ray propagation or acceleration at very high energy can potentially play a role. Other violations of fundamental principles of standard particle physics (quantum mechanics, energy and momentum conservation, vacuum homogeneity and “static” properties, effective space dimensions, quark confinement… can also be relevant at these energies. In particular, UHECR data would in principle allow to set bounds on Lorentz symmetry violation (LSV in patterns incorporating a privileged local reference frame (the “vacuum rest frame”, VRF. But the precise analysis is far from trivial, and other effects can also be present. The effective parameters can be related to Planckscale physics, or even to physics beyond Planck scale, as well as to the dynamics and effective symmetries of LSV for nucleons, quarks, leptons and the photon. LSV can also be at the origin of GZK-like effects. In the presence of a VRF, and contrary to a “grand unification” view, LSV and other violations of standard principles can modify the internal structure of particles at very high energy and conventional symmetries may cease to be valid at energies close to the Planck scale. We present an updated discussion of these topics, including experimental prospects, new potentialities for high-energy cosmic ray phenomenology and the possible link with unconventional pre-Big Bang scenarios, superbradyon (superluminal preon patterns… The subject of a possible superluminal propagation of neutrinos at accelerator energies is also dealt with.

  16. First-principles calculations of mechanical and electronic properties of silicene under strain

    Directory of Open Access Journals (Sweden)

    Rui Qin

    2012-06-01

    Full Text Available We perform first-principles calculations of mechanical and electronic properties of silicene under strains. The in-plane stiffness of silicene is much smaller than that of graphene. The yielding strain of silicene under uniform expansion in the ideal conditions is about 20%. The homogeneous strain can introduce a semimetal-metal transition. The semimetal state of silicene, in which the Dirac cone locates at the Fermi level, can only persist up to tensile strain of 7% with nearly invariant Fermi velocity. For larger strains, silicene changes into a conventional metal. The work function is found to change significantly under biaxial strain. Our calculations show that strain tuning is important for applications of silicene in nanoelectronics.

  17. High school physical educators' and sport coaches' knowledge of resistance training principles and methods.

    Science.gov (United States)

    McGladrey, Brian W; Hannon, James C; Faigenbaum, Avery D; Shultz, Barry B; Shaw, Janet M

    2014-05-01

    The purpose of this study was to determine the level of knowledge that current and preservice high school (HS) physical educators and sport coaches possess regarding the principles and methods involved in youth resistance training (RT) and to determine if that knowledge was acceptable based on a predetermined criterion (passing score). A panel of 10 experts in RT or sport pedagogy used a Delphi technique to create a 90-question assessment (examination) that was administered to 287 HS physical educators and sport coaches and 140 university physical education teacher education (PETE) students. An analysis of the results revealed that neither group demonstrated the minimal knowledge necessary to design, implement, and supervise RT programs based on a passing score of 75%: HS physical educators/coaches, mean = 59.30, SD = 14.30, 95% confidence interval (CI) = 57.64-60.96], t(286) = -18.61, p = 0.000; university PETE students, mean = 56.61, SD = 16.59, 95% CI = 53.84-59.38, t(139) = -13.12, p = 0.000. The pass rate for physical educators and sport coaches was 14.3% and for university PETE students it was 20.7%. The results of this study indicate that both current and preservice physical educators and sport coaches need additional education and training specific to the design and implementation of RT programs for HS students. Given that school districts typically require their educators attend in-service training programs, it may be advisable to develop an in-service program that allows both current and preservice HS physical educators and sport coaches to earn an RT certification that specifically addresses the unique physical and psychosocial needs of school-aged youth.

  18. Principles, Economic and Institutional Prerequisites for Fiscal Decentralization under Conditions of Post-Conflict Reconstruction

    Directory of Open Access Journals (Sweden)

    Vishnevsky Valentine P.

    2016-11-01

    Full Text Available The aim of the article is to study principles, economic and institutional prerequisites for fiscal decentralization on post-conflict territories. It is determined that fiscal decentralization is one of the main ways to solve problems of post-conflict areas. There justified principles, economic and institutional prerequisites of fiscal decentralization on post-conflict territories with regard to the specificity of individual spheres of fiscal relations. Moreover, different spheres of fiscal relations require different approaches: the sphere of public revenues — providing economic efficiency with the formation of the tax structure contributing to the expansion of the tax base; the sphere of public spending — ensuring social justice and transparency in allocation of social cost at the local level; the sphere of subsidies — narrowing the scope of application of intergovernmental transfers with organizing the redistribution of financial resources under the principle of «center - post-conflict regions - post-conflict recipients»; the sphere of external assistance — ensuring proper coordination for cultivation of new co-operative institutions.

  19. Physical and chemical mechanisms underlying hematoma evolution

    International Nuclear Information System (INIS)

    Cho, K.J.; Fanders, B.L.; Smid, A.R.; McLaughlin, P.

    1986-01-01

    Angiostat, a new collagen embolic material supplied at a concentration of 35 mg/ml (Target Therapeutics, Los Angeles) was used for flow-directed hepatic artery embolization in a series of rabbits to examine its acute effects on hepatic microcirculation. Arteriograms were obtained both before and after embolization. The aorta and portal vein were perfused with two different colors of Microfil after the animals were killed,. Cleared liver specimens were examined under a dissection microscope. Extent of dearterialization, status of portal sinusoidal perfusion, and collateral formation after embolization with Angiostat were evaluated. Results will be compared with results achieved using other liquid and particulate embolic agents

  20. Differentiation with Stratification: A Principle of Theoretical Physics in the Tradition of the Memory Art

    Science.gov (United States)

    Pombo, Claudia

    2015-10-01

    The art of memory started with Aristotle's questions on memory. During its long evolution, it had important contributions from alchemists, was transformed by Ramon Llull and apparently ended with Giordano Bruno, who was considered the best known representative of this art. This tradition did not disappear, but lives in the formulations of our modern scientific theories. From its initial form as a method of keeping information via associations, it became a principle of classification and structuring of knowledge. This principle, which we here name differentiation with stratification, is a structural design behind classical mechanics. Integrating two different traditions of science in one structure, this physical theory became the modern paradigm of science. In this paper, we show that this principle can also be formulated as a set of questions. This is done via an analysis of theories, based on the epistemology of observational realism. A combination of Rudolph Carnap's concept of theory as a system of observational and theoretical languages, with a criterion for separating observational languages, based on analytical psychology, shapes this epistemology. The `nuclear' role of the observational laws and the differentiations from these nucleus, reproducing the general cases of phenomena, reveals the memory art's heritage in the theories. Here in this paper we argue that this design is also present in special relativity and in quantum mechanics.

  1. Emission tomography with positrons principle, physical performances of a ring detector and quantitative possibilities

    International Nuclear Information System (INIS)

    Soussaline, F.; Plummer, D.; Todd Pokropek, A.E.; Loc'h, C.; Comar, D.

    1979-01-01

    Satisfactory qualitative and quantitative data in positron emission tomography requires the use of a well adapted tomographic system. A number of parameters have been identified which can be considered as the critical characteristics for evaluation and intercomparison of such systems. Using these the choice of a single slice ring positron camera could be justified by its physical performance, which is presented and discussed. Series of physical and mathematical simulations allow an appropriate knowledge of such a system, which has been in use for more than a year in a clinical environment. These studies aid to the interpretation of very interesting physiopathologic studies. In principle, a positron tomographic system permits measurement of absolute quantitative concentration values, which are essential for precise metabolic studies. The main sources of error comprising the calibration of the system, the tail effects and the precision for attenuation correction are analysed. When taking in account these errors, a precision of the order of 10% should be obtainable [fr

  2. The next generation mass storage devices - Physical principles and current status

    Science.gov (United States)

    Wang, L.; Gai, S.

    2014-04-01

    The amount of digital data today has been increasing at a phenomenal rate due to the widespread digitalisation service in almost every industry. The need to store such ever-increasing data aggressively triggers the requirement to augment the storage capacity of the conventional storage technologies. Unfortunately, the physical limitations that conventional forms face have severely handicapped their potential to meet the storage need from both consumer and industry point of view. The focus has therefore been switched into the development of the innovative data storage technologies such as scanning probe memory, nanocrystal memory, carbon nanotube memory, DNA memory, and organic memory. In this paper, we review the physical principles of these emerging storage technologies and their superiorities as the next generation data storage device, as well as their respective technical challenges on further enhancing the storage capacity. We also compare these novel technologies with the mainstream data storage means according to the technology roadmap on areal density.

  3. General Principles and Convention on Contracts for the International Sale of Goods (CISG – Uniformity under an Interpretation Umbrella?

    Directory of Open Access Journals (Sweden)

    Laura Lassila

    2017-01-01

    Full Text Available Globalization and digitalization of international sales creates needs to harmonize rules of international commercial contracts. The question is whether the harmonization should be done by binding rules or using soft law tools or through digitalization. In this article I argue on favor of harmonization through international contracts law rules’ international interpretation.The international interpretation principles used in this article are found from on Art. 7(1 of the Convention on Contracts for the International Sale of Goods (CISG which sets three interpretation rules: international character; promoting uniformity; and observance of good faith in international trade. These principles are not only principles of the CISG, but also principles commonly recognized in international commercial practice and also in domestic contract rules. I argue that by adopting an international interpretation umbrella – the meta-principle of international interpretation, cross-border contracts could be interpreted under the same principle no matter applicable substantial law. The meta-principle functions as an interpretation umbrella covering general principles and Articles of the CISG, general principles of international commercial contracts, Lex Mercatoria, and cross-border contract provision under national law.The outcomes points out that arbitral tribunals have interpreted general principles of the CISG and Lex Mercatoria in various ways. General principles and their application in case law is analyzed in connection with the Civil Code of the Russian Federation. Tribunals found that general principles of the CISG are applicable even if the CISG is not. It follows Art.’s 7(2 logic to promote international standard to cross-border contracts where the closes connection is international commercial practice rather than any national jurisdiction.

  4. First principles study of iron-bearing MgO under ultrahigh pressure

    Science.gov (United States)

    Umemoto, K.; Hsu, H.

    2017-12-01

    Understanding of minerals under ultrahigh pressure is essential to model interiors of super-Earths. Chemical compositions of the super-Earths are expected to be similar to those of the Earth. Computational studies on Mg-Si-O ternary systems under ultrahigh pressures, which are difficult to be achieved by diamond-anvil-cell experiments, have been intensively performed (e.g., [1] for MgO, [2,3] for SiO2, and [4,5] for MgSiO3). However, as far as we know, these studies have been restricted to pure Mg-Si-O systems. In the mantles of super-Earths, we expect that there should be impurities as in the Earth's mantle. Among candidates of impurities, iron is especially important to model interiors of super-Earths. Here, we investigate iron-bearing MgO under ultrahigh pressures by first principles. We clarify effects of iron on the phase transition of MgO and thermodynamic quantities by first principles. The role of the 3d electrons will be elucidated. [1] Z. Wu, R. M. Wentzcovitch, K. Umemoto, B. Li, K. Hirose, and J. C. Zheng, J. Geophys. Res. 113, B06204 (2008). [2] S. Q. Wu, K. Umemoto, M. Ji, C. Z. Wang, K. M. Ho, and R. M. Wentzcovitch, Phys. Rev. B 83, 184102 (2011). [3] T. Tsuchiya and J. Tsuchiya, Proc. Nat. Acad. Sci. 108, 1252 (2011) [4] S. Q. Wu, M. Ji, C. Z. Wang, M. C. Nguye, X. Zhao, K. Umemoto, R. M. Wentzcovitch, and K. M. Ho, J. Phys.: Condens. Matter 26, 035402 (2014). [5] H. Niu, A. R. Oganov, X.-C. Chen, and D. Li, Sci. Rep. 5, 18347 (2015).

  5. Introduction to Stochastic Simulations for Chemical and Physical Processes: Principles and Applications

    Science.gov (United States)

    Weiss, Charles J.

    2017-01-01

    An introduction to digital stochastic simulations for modeling a variety of physical and chemical processes is presented. Despite the importance of stochastic simulations in chemistry, the prevalence of turn-key software solutions can impose a layer of abstraction between the user and the underlying approach obscuring the methodology being…

  6. Investigating and improving introductory physics students’ understanding of the electric field and superposition principle

    Science.gov (United States)

    Li, Jing; Singh, Chandralekha

    2017-09-01

    We discuss an investigation of the difficulties that students in a university introductory physics course have with the electric field and superposition principle and how that research was used as a guide in the development and evaluation of a research-validated tutorial on these topics to help students learn these concepts better. The tutorial uses a guided enquiry-based approach to learning and involved an iterative process of development and evaluation. During its development, we obtained feedback both from physics instructors who regularly teach introductory physics in which these concepts are taught and from students for whom the tutorial is intended. The iterative process continued and the feedback was incorporated in the later versions of the tutorial until the researchers were satisfied with the performance of a diverse group of introductory physics students on the post-test after they worked on the tutorial in an individual one-on-one interview situation. Then the final version of the tutorial was administered in several sections of the university physics course after traditional instruction in relevant concepts. We discuss the performance of students in individual interviews and on the pre-test administered before the tutorial (but after traditional lecture-based instruction) and on the post-test administered after the tutorial. We also compare student performance in sections of the class in which students worked on the tutorial with other similar sections of the class in which students only learned via traditional instruction. We find that students performed significantly better in the sections of the class in which the tutorial was used compared to when students learned the material via only lecture-based instruction.

  7. IFLA Principles Underlying Subject Heading Languages: strenghts and weaknesses revealed by user behaviour

    Directory of Open Access Journals (Sweden)

    Alenka Šauperl

    2005-01-01

    Full Text Available IFLA Principles Underlying Subject Heading Languages were published in 1995 and translated into Slovene in 2002. They try to recover the theory of indexing languages from an analysis of subject heading languages that are used in libraries around the world. These guidelines are illustrated with examples from Splošni slovenski geslovnik (Slovene General Subject Headings, Sears List of Subject Headings, and Library of Congress Subject Headings (LCSH. Studies on the use of LCSH by users of library catalogs were reviewed to determine weaknesses of the IFLA Principles. Changes were suggested,which would make subject retrieval easier for users. The reviewed subject heading languages reflect the needs of traditional librarians and card catalogs. These often conflict with user needs, characteristics of online catalogs and modern librarians.Subject heading languages could be improved if we would take into account the vast knowledge of user behavior and capabilities of information technology. For a better subject access to library materials, we also need to understand the processes of subject analysis and subject description.

  8. Physical principles, geometrical aspects, and locality properties of gauge field theories

    International Nuclear Information System (INIS)

    Mack, G.; Hamburg Univ.

    1981-01-01

    Gauge field theories, particularly Yang - Mills theories, are discussed at a classical level from a geometrical point of view. The introductory chapters are concentrated on physical principles and mathematical tools. The main part is devoted to locality problems in gauge field theories. Examples show that locality problems originate from two sources in pure Yang - Mills theories (without matter fields). One is topological and the other is related to the existence of degenerated field configurations of the infinitesimal holonomy groups on some extended region of space or space-time. Nondegenerate field configurations in theories with semisimple gauge groups can be analysed with the help of the concept of a local gauge. Such gauges play a central role in the discussion. (author)

  9. Structural, Mechanical and Thermodynamic Properties under Pressure Effect of Rubidium Telluride: First Principle Calculations

    Directory of Open Access Journals (Sweden)

    Bidai K.

    2017-06-01

    Full Text Available First-principles density functional theory calculations have been performed to investigate the structural, elastic and thermodynamic properties of rubidium telluride in cubic anti-fluorite (anti-CaF2-type structure. The calculated ground-state properties of Rb2Te compound such as equilibrium lattice parameter and bulk moduli are investigated by generalized gradient approximation (GGA-PBE that are based on the optimization of total energy. The elastic constants, Young’s and shear modulus, Poisson ratio, have also been calculated. Our results are in reasonable agreement with the available theoretical and experimental data. The pressure dependence of elastic constant and thermodynamic quantities under high pressure are also calculated and discussed.

  10. Waves as the Symmetry Principle Underlying Cosmic, Cell, and Human Languages

    Directory of Open Access Journals (Sweden)

    Sungchul Ji

    2017-02-01

    Full Text Available In 1997, the author concluded that living cells use a molecular language (cellese that is isomorphic with the human language (humanese based on his finding that the former shared 10 out of the 13 design features of the latter. In 2012, the author postulated that cellese and humanese derived from a third language called the cosmic language (or cosmese and that what was common among these three kinds of languages was waves—i.e., sound waves for humanese, concentration waves for cellese, and quantum waves for cosmese. These waves were suggested to be the symmetry principle underlying cosmese, cellese, and humanese. We can recognize at least five varieties of waves—(i electromagnetic; (ii mechanical; (iii chemical concentration; (iv gravitational; and (v probability waves, the last being non-material, in contrast to the first four, which are all material. The study of waves is called “cymatics” and the invention of CymaScope by J. S. Reid of the United Kingdom in 2002 is expected to accelerate the study of waves in general. CymaScope has been used to visualize not only human sounds (i.e., humanese but also sounds made by individual cells (cellese in conjunction with Atomic Force Microscopy (AFM (unpublished observations of J. Gimzewski of UCLA and J. Reid. It can be predicted that the gravitational waves recently detected by the Interferometer Gravitational-Wave Observatory (LIGO will be visualized with CymaScope one day, thereby transforming gravitational waves into CymaGlyphs. Since cellese in part depends on RNA concentration waves (or RNA glyphs and humanese includes hieroglyphs that were decoded by Champollion in 1822, it seems reasonable to use cymaglyphs, RNA glyphs, and hieroglyphs as symbols of cosmese, cellese, and humanese, respectively, all based on the principle of waves as the medium of communication.

  11. Polymethylmethacrylate and radioisotopes in vertebral augmentation: an explanation of underlying principles.

    Science.gov (United States)

    Hirsch, Ariel E; Rosenstein, Barry S; Medich, David C; Martel, Christopher B; Hirsch, Joshua A

    2009-01-01

    We recently reported a novel concept for combining radioactive isotope technology with polymethylmethacrylate (PMMA) cement used for vertebral augmentation and have advocated that pain physicians become aware of this new concept when treating malignant compression fractures. The use of vertebral augmentation for malignant compression fractures is steadily increasing, and the goal of this novel approach would be to stabilize the fractured vertebral body while also controlling proliferation of the tumor cells in the vertebral body that caused the vertebral fracture. This approach would therefore provide mechanical stabilization of the fractured vertebral body at the same time as direct targeting of the cancer cells causing the fracture. For our analysis, we investigated six specific radioisotopes with regard to physical and biologic properties as they would interact with PMMA and local bone metastatic disease, taking into consideration anatomical, biological and physical characteristics. The radioisotopes investigated include beta emitting (plus and minus) sources, as well as low energy and mid-energy photon sources and are: P-32, Ho-166, Y-90, I-125, F-18, and Tc-99m. We review the advantages and disadvantages of each radioisotope. In addition, this paper serves to provide pain physicians with a basic background of the biologic principles (Biologically Effective Dose) and statistical modeling (Monte Carlo method) used in that analysis. We also review the potential complications when using radioactive sources in a clinical setting. Understanding the methodologies employed in determining isotope selection empowers the practitioner by fostering understanding of this presently theoretical treatment option. We believe that embedding radioisotopes in PMMA is merely a first step in the road of local treatment for symptomatic local lesions in the setting of systemic disease.

  12. First Principles Prediction of Structure, Structure Selectivity, and Thermodynamic Stability under Realistic Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ceder, Gerbrand [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Materials and Engineering

    2018-01-28

    Novel materials are often the enabler for new energy technologies. In ab-initio computational materials science, method are developed to predict the behavior of materials starting from the laws of physics, so that properties can be predicted before compounds have to be synthesized and tested. As such, a virtual materials laboratory can be constructed, saving time and money. The objectives of this program were to develop first-principles theory to predict the structure and thermodynamic stability of materials. Since its inception the program focused on the development of the cluster expansion to deal with the increased complexity of complex oxides. This research led to the incorporation of vibrational degrees of freedom in ab-initio thermodynamics, developed methods for multi-component cluster expansions, included the explicit configurational degrees of freedom of localized electrons, developed the formalism for stability in aqueous environments, and culminated in the first ever approach to produce exact ground state predictions of the cluster expansion. Many of these methods have been disseminated to the larger theory community through the Materials Project, pymatgen software, or individual codes. We summarize three of the main accomplishments.

  13. Physical principles and current status of emerging non-volatile solid state memories

    Science.gov (United States)

    Wang, L.; Yang, C.-H.; Wen, J.

    2015-07-01

    Today the influence of non-volatile solid-state memories on persons' lives has become more prominent because of their non-volatility, low data latency, and high robustness. As a pioneering technology that is representative of non-volatile solidstate memories, flash memory has recently seen widespread application in many areas ranging from electronic appliances, such as cell phones and digital cameras, to external storage devices such as universal serial bus (USB) memory. Moreover, owing to its large storage capacity, it is expected that in the near future, flash memory will replace hard-disk drives as a dominant technology in the mass storage market, especially because of recently emerging solid-state drives. However, the rapid growth of the global digital data has led to the need for flash memories to have larger storage capacity, thus requiring a further downscaling of the cell size. Such a miniaturization is expected to be extremely difficult because of the well-known scaling limit of flash memories. It is therefore necessary to either explore innovative technologies that can extend the areal density of flash memories beyond the scaling limits, or to vigorously develop alternative non-volatile solid-state memories including ferroelectric random-access memory, magnetoresistive random-access memory, phase-change random-access memory, and resistive random-access memory. In this paper, we review the physical principles of flash memories and their technical challenges that affect our ability to enhance the storage capacity. We then present a detailed discussion of novel technologies that can extend the storage density of flash memories beyond the commonly accepted limits. In each case, we subsequently discuss the physical principles of these new types of non-volatile solid-state memories as well as their respective merits and weakness when utilized for data storage applications. Finally, we predict the future prospects for the aforementioned solid-state memories for

  14. Basic principles

    International Nuclear Information System (INIS)

    Wilson, P.D.

    1996-01-01

    Some basic explanations are given of the principles underlying the nuclear fuel cycle, starting with the physics of atomic and nuclear structure and continuing with nuclear energy and reactors, fuel and waste management and finally a discussion of economics and the future. An important aspect of the fuel cycle concerns the possibility of ''closing the back end'' i.e. reprocessing the waste or unused fuel in order to re-use it in reactors of various kinds. The alternative, the ''oncethrough'' cycle, discards the discharged fuel completely. An interim measure involves the prolonged storage of highly radioactive waste fuel. (UK)

  15. J/ψ+χcJ production at the B factories under the principle of maximum conformality

    International Nuclear Information System (INIS)

    Wang, Sheng-Quan; Wu, Xing-Gang; Zheng, Xu-Chang; Shen, Jian-Ming; Zhang, Qiong-Lian

    2013-01-01

    Under the conventional scale setting, the renormalization scale uncertainty usually constitutes a systematic error for a fixed-order perturbative QCD estimation. The recently suggested principle of maximum conformality (PMC) provides a principle to eliminate such scale ambiguity in a step-by-step way. Using the PMC, all non-conformal terms in perturbative expansion series are summed into the running coupling, and one obtains a unique, scale-fixed, scheme-independent prediction at any finite order. In the paper, we make a detailed PMC analysis for both the polarized and the unpolarized cross sections for the double charmonium production process, e + +e − →J/ψ(ψ ′ )+χ cJ with (J=0,1,2). The running behavior for the coupling constant, governed by the PMC scales, are determined exactly for the specific processes. We compare our predictions with the measurements at the B factories, BaBar and Belle, and the theoretical estimations obtained in the literature. Because the non-conformal terms are different for various polarized and unpolarized cross sections, the PMC scales of these cross sections are different in principle. It is found that all the PMC scales are almost independent of the initial choice of renormalization scale. Thus, the large renormalization scale uncertainty usually adopted in the literature up to ∼40% at the NLO level, obtained from the conventional scale setting, for both the polarized and the unpolarized cross sections are greatly suppressed. It is found that the charmonium production is dominated by J=0 channel. After PMC scale setting, we obtain σ(J/ψ+χ c0 )=12.25 −3.13 +3.70 fb and σ(ψ ′ +χ c0 )=5.23 −1.32 +1.56 fb, where the squared average errors are caused by bound state parameters as m c , |R J/ψ (0)| and |R χ cJ ′ (0)|, which are non-perturbative error sources in different to the QCD scale setting problem. In comparison to the experimental data, a more accurate theoretical estimation shall be helpful for a precise

  16. A Novel Physical Sensing Principle for Liquid Characterization Using Paper-Based Hygro-Mechanical Systems (PB-HMS).

    Science.gov (United States)

    Perez-Cruz, Angel; Stiharu, Ion; Dominguez-Gonzalez, Aurelio

    2017-07-20

    In recent years paper-based microfluidic systems have emerged as versatile tools for developing sensors in different areas. In this work; we report a novel physical sensing principle for the characterization of liquids using a paper-based hygro-mechanical system (PB-HMS). The PB-HMS is formed by the interaction of liquid droplets and paper-based mini-structures such as cantilever beams. The proposed principle takes advantage of the hygroscopic properties of paper to produce hygro-mechanical motion. The dynamic response of the PB-HMS reveals information about the tested liquid that can be applied to characterize certain properties of liquids. A suggested method to characterize liquids by means of the proposed principle is introduced. The experimental results show the feasibility of such a method. It is expected that the proposed principle may be applied to sense properties of liquids in different applications where both disposability and portability are of extreme importance.

  17. Principles underlying the design of "The Number Race", an adaptive computer game for remediation of dyscalculia.

    Science.gov (United States)

    Wilson, Anna J; Dehaene, Stanislas; Pinel, Philippe; Revkin, Susannah K; Cohen, Laurent; Cohen, David

    2006-05-30

    Adaptive game software has been successful in remediation of dyslexia. Here we describe the cognitive and algorithmic principles underlying the development of similar software for dyscalculia. Our software is based on current understanding of the cerebral representation of number and the hypotheses that dyscalculia is due to a "core deficit" in number sense or in the link between number sense and symbolic number representations. "The Number Race" software trains children on an entertaining numerical comparison task, by presenting problems adapted to the performance level of the individual child. We report full mathematical specifications of the algorithm used, which relies on an internal model of the child's knowledge in a multidimensional "learning space" consisting of three difficulty dimensions: numerical distance, response deadline, and conceptual complexity (from non-symbolic numerosity processing to increasingly complex symbolic operations). The performance of the software was evaluated both by mathematical simulations and by five weeks of use by nine children with mathematical learning difficulties. The results indicate that the software adapts well to varying levels of initial knowledge and learning speeds. Feedback from children, parents and teachers was positive. A companion article describes the evolution of number sense and arithmetic scores before and after training. The software, open-source and freely available online, is designed for learning disabled children aged 5-8, and may also be useful for general instruction of normal preschool children. The learning algorithm reported is highly general, and may be applied in other domains.

  18. Principles underlying the design of "The Number Race", an adaptive computer game for remediation of dyscalculia

    Directory of Open Access Journals (Sweden)

    Cohen Laurent

    2006-05-01

    Full Text Available Abstract Background Adaptive game software has been successful in remediation of dyslexia. Here we describe the cognitive and algorithmic principles underlying the development of similar software for dyscalculia. Our software is based on current understanding of the cerebral representation of number and the hypotheses that dyscalculia is due to a "core deficit" in number sense or in the link between number sense and symbolic number representations. Methods "The Number Race" software trains children on an entertaining numerical comparison task, by presenting problems adapted to the performance level of the individual child. We report full mathematical specifications of the algorithm used, which relies on an internal model of the child's knowledge in a multidimensional "learning space" consisting of three difficulty dimensions: numerical distance, response deadline, and conceptual complexity (from non-symbolic numerosity processing to increasingly complex symbolic operations. Results The performance of the software was evaluated both by mathematical simulations and by five weeks of use by nine children with mathematical learning difficulties. The results indicate that the software adapts well to varying levels of initial knowledge and learning speeds. Feedback from children, parents and teachers was positive. A companion article 1 describes the evolution of number sense and arithmetic scores before and after training. Conclusion The software, open-source and freely available online, is designed for learning disabled children aged 5–8, and may also be useful for general instruction of normal preschool children. The learning algorithm reported is highly general, and may be applied in other domains.

  19. First-principles study of magnetism in Pd3Fe under pressure

    Science.gov (United States)

    Dutta, Biswanath; Bhandary, Sumanta; Ghosh, Subhradip; Sanyal, Biplab

    2012-07-01

    Recent experiments on Pd3Fe intermetallics [M. L. Winterrose , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.102.237202 102, 237202 (2009)] have revealed that the system behaves like a classical invar alloy under high pressure. The experimental pressure-volume relation suggests an anomalous volume collapse and a substantial increase in bulk modulus around the pressure where invar behavior is observed. With the help of first-principles density functional theory based calculations, we have explored various magnetic phases (ferromagnetic, fully and partially disordered local moment, spin spiral) in order to understand the effect of pressure on magnetism. Our calculations reveal that the system does not undergo a transition from a ferromagnetic to a spin-disordered state, as was thought to be the possible mechanism to explain the invar behavior of this system. We rather suggest that the anomaly in the system could possibly be due to the transition from a collinear state to noncollinear magnetic states upon the application of pressure.

  20. First-principles calculation of transport property in nano-devices under an external magnetic field

    International Nuclear Information System (INIS)

    Chen Jingzhe; Zhang Jin; Han Rushan

    2008-01-01

    The mesoscopic quantum interference phenomenon (QIP) can be observed and behaves as the oscillation of conductance in nano-devices when the external magnetic field changes. Excluding the factor of impurities or defects, specific QIP is determined by the sample geometry. We have improved a first-principles method based on the matrix Green's function and the density functional theory to simulate the transport behaviour of such systems under a magnetic field. We have studied two kinds of QIP: universal conductance fluctuation (UCF) and Aharonov–Bohm effect (A–B effect). We find that the amplitude of UCF is much smaller than the previous theoretical prediction. We have discussed the origin of difference and concluded that due to the failure of ergodic hypothesis, the ensemble statistics is not applicable, and the conductance fluctuation is determined by the flux-dependent density of states (DOSs). We have also studied the relation between the UCF and the structure of sample. For a specific structure, an atomic circle, the A–B effect is observed and the origin of the oscillation is also discussed

  1. Physical Properties of Superhard Diamond-Like BC5 from a First-Principles Study

    Science.gov (United States)

    Alp, Irem O.; Ciftci, Yasemin O.

    2018-01-01

    The first-principles calculations are carried out to investigate the structural, elastic, electronic, optical, vibrational and thermodynamic properties of superhard diamond-like BC5 (d-BC5). The structural stability of BC5 is examined for previously proposed and several probable phases including F-43m, P6/mmm, Cmcm, Pnma, P-1, P3m1, Imm2, I-4m2 and Pmma. The most energetically stable phase is predicted to be Pmma. Computed bulk modulus B, shear modulus G, elastic constant C 44 and theoretical Vickers hardness H confirm that BC5 is an ultra-incompressible and superhard material. The electronic character analysis reveals the metallicity of BC5, indicating that a strong covalent bond network through sp 3 hybridization is the origin of its excellent mechanical properties. However, P-1 is found to be dynamically stable, contrary to the other study. Therefore, the phonon, thermodynamic and electronic properties of P-1 which are not available in the literature are discussed. The calculated physical parameters are in good agreement with the theoretical and experimental results. This work is expected to provide a useful guide for designing novel boride materials having superior mechanical performance.

  2. The principle and physical models of novel jetting dispenser with giant magnetostrictive and a magnifier.

    Science.gov (United States)

    Zhou, C; Li, J H; Duan, J A; Deng, G L

    2015-12-16

    In order to develop jetting technologies of glue in LED and microelectronics packaging, giant-magnetostrictive-material (GMM) is firstly applied to increase jetting response, and a new magnifying device including a lever and a flexible hinge is designed to improve jetting characteristics. Physical models of the jetting system are derived from the magnifying structure and working principle, which involves circuit model, electro-magneto-displacement model, dynamic model and fluid-solid coupling model. The system model is established by combining mathematical models with Matlab-Simulink. The effectiveness of the GMM-based dispenser is confirmed by simulation and experiments. The jetting frequency significantly increases to 250 Hz, and dynamic behaviors jetting needle are evaluated that the velocity and displacement of the jetting needle reaches to 320 mm•s-1 and 0.11 mm respectively. With the increasing of the filling pressure or the amplitude of the current, the dot size will become larger. The dot size and working frequency can be easily adjusted.

  3. Efficiencies and Physical Principles of Various Solar Energy Conversion Processes Leading to the Photolysis of Water

    Energy Technology Data Exchange (ETDEWEB)

    Bergene, T.

    1995-12-31

    In the application of solar energy, hydrogen is likely to be used as an energy carrier and a storage medium. Production of molecular hydrogen and oxygen from water requires energy input, which may come from solar energy in various ways. This thesis begins with a literature survey of the different conversion processes and the efficiencies, which is an introduction to a series of enclosed papers. These papers are: (1) Trapping of Minority Charge Carriers at Irradiated Semiconductor/Electrolyte Heterojunctions, (2) Model Calculations on Flat-Plate Solar Heat Collector With Integrated Solar Cells, and (3) Efficiencies and Physical Principles of Photolysis of Water By Microalgae. In the papers, The qualitative features of the ``illumination-current``-characteristic curve are deduced. The hypothesis is that trapping originates in some specific cases because of confinement, which leads to charge injections into energy states above that corresponding to the band edge. The quantitative features of certain hybrid photovoltaic/thermal configuration are deduced. An analysis of the theoretical and realizable efficiencies of the photolysis of water by micro algae is given. 151 refs., 18 figs., 1 table

  4. The birth of the blues: how physics underlies music

    International Nuclear Information System (INIS)

    Gibson, J M

    2009-01-01

    Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'. Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.

  5. The birth of the blues: how physics underlies music

    Science.gov (United States)

    Gibson, J. M.

    2009-07-01

    Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'. Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.

  6. The birth of the blues: how physics underlies music

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J M [Argonne National Laboratory, 9700 Cass Avenue, Argonne IL 60439 (United States)], E-mail: jmgibson@aps.anl.gov

    2009-07-15

    Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'. Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.

  7. The birth of the blues : how physics underlies music.

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J. M.

    2009-07-01

    Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'. Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.

  8. Prediction of Stable Ruthenium Silicides from First-Principles Calculations: Stoichiometries, Crystal Structures, and Physical Properties.

    Science.gov (United States)

    Zhang, Chuanzhao; Kuang, Xiaoyu; Jin, Yuanyuan; Lu, Cheng; Zhou, Dawei; Li, Peifang; Bao, Gang; Hermann, Andreas

    2015-12-09

    We present results of an unbiased structure search for stable ruthenium silicide compounds with various stoichiometries, using a recently developed technique that combines particle swarm optimization algorithms with first-principles calculations. Two experimentally observed structures of ruthenium silicides, RuSi (space group P2(1)3) and Ru2Si3 (space group Pbcn), are successfully reproduced under ambient pressure conditions. In addition, a stable RuSi2 compound with β-FeSi2 structure type (space group Cmca) was found. The calculations of the formation enthalpy, elastic constants, and phonon dispersions demonstrate the Cmca-RuSi2 compound is energetically, mechanically, and dynamically stable. The analysis of electronic band structures and densities of state reveals that the Cmca-RuSi2 phase is a semiconductor with a direct band gap of 0.480 eV and is stabilized by strong covalent bonding between Ru and neighboring Si atoms. On the basis of the Mulliken overlap population analysis, the Vickers hardness of the Cmca structure RuSi2 is estimated to be 28.0 GPa, indicating its ultra-incompressible nature.

  9. A Novel Physical Sensing Principle for Liquid Characterization Using Paper-Based Hygro-Mechanical Systems (PB-HMS)

    OpenAIRE

    Perez-Cruz, Angel; Stiharu, Ion; Dominguez-Gonzalez, Aurelio

    2017-01-01

    In recent years paper-based microfluidic systems have emerged as versatile tools for developing sensors in different areas. In this work; we report a novel physical sensing principle for the characterization of liquids using a paper-based hygro-mechanical system (PB-HMS). The PB-HMS is formed by the interaction of liquid droplets and paper-based mini-structures such as cantilever beams. The proposed principle takes advantage of the hygroscopic properties of paper to produce hygro-mechanical m...

  10. First-principles study of ternary Li-Al-Te compounds under high pressure

    Science.gov (United States)

    Wang, Youchun; Tian, Fubo; Li, Da; Duan, Defang; Xie, Hui; Liu, Bingbing; Zhou, Qiang; Cui, Tian

    2018-02-01

    The ternary Li-Al-Te compounds were investigated by the first-principle evolutionary calculation based on density function theory. Apart from the known structure, I-42d LiAlTe2 and P3m1 LiAlTe2, several new structures were discovered, P-3m1 LiAlTe2, Pnma LiAlTe2, C2/c Li9AlTe2, Immm Li9AlTe2 and P4/mmm Li6AlTe. We determined that the I-42d LiAlTe2 firstly changed to P-3m1 phase at 6 GPa, and then into the Pnma structure at 65 GPa, Pnma phase was stable up at least to 120 GPa. I-42d LiAlTe2 was a pseudo-direct band gap semiconductor, but P-3m1 LiAlT2 was an indirect band gap semiconductor. This may be caused by the pressure effect. Subsequently, it was metallized under pressure. Pnma LiAlTe2 was also metallic at the pressure we studied. C2/c Li9AlTe2 was stable above 4 GPa, then turned into Immm phase at 60 GPa. C2/c Li9AlTe2 was an indirect band gap semiconductor. The results show that P4/mmm Li6AlTe was stable and metallized in the pressure range of 0.7-120 GPa. The calculations of DOS and PDOS indicate that the arrangement of electrons near Fermi energy can be affected by the increase of Li. The calculated ELF results and Bader charge analysis indicate that there was no covalent bond between Al and Te atoms for high-pressure Pnma LiAlTe2, Li9AlTe2 and Li6AlTe. For Li9AlTe2 and Li6AlTe, different from LiAlTe2, Al atoms not connect with Te atoms, but link with Li atoms. The results were further proved by Mulliken population analysis. And the weak covalent bonds between Li and Al atoms stem from the hybridization of Li s and Al p presented in PDOS diagrams. We further deduced that the pressure effect and the increase of Li content may result in the disappearance of Al-Te bonds for Li-Al-Te compound under extreme pressure.

  11. DEGRO practical guidelines for radiotherapy of non-malignant disorders. Part I: physical principles, radiobiological mechanisms, and radiogenic risk

    Energy Technology Data Exchange (ETDEWEB)

    Reichl, Berthold [Hospital Weiden, Department of Radiotherapy and Radiation Oncology, Weiden (Germany); Block, Andreas [Hospital Dortmund, Institute for Medical Radiation Physics and Radiation Protection, Dortmund (Germany); Schaefer, Ulrich [Lippe Hospital, Dept. of Radiotherapy, Lemgo (Germany); Bert, Christoph; Mueller, Reinhold [University Hospitals Erlangen, Dept. of Radiation Oncology, Erlangen (Germany); Jung, Horst [University Hospital Hamburg-Eppendorf, Dept. of Radiotherapy and Radiation Oncology, Hamburg (Germany); Roedel, Franz [University Hospital Goethe-University, Dept. of Radiotherapy and Oncology, Frankfurt am Main (Germany); Collaboration: the German Cooperative Group on Radiotherapy for Benign Diseases (GCG-BD)

    2015-09-15

    Synopsis of the introductory paragraph of the DEGRO consensus S2e-guideline recommendations for the radiotherapy of benign disorders, including physical principles, radiobiological mechanisms, and radiogenic risk. This work is based on the S2e-guideline recommendations published November 14, 2013. The basic principles of radiation physics and treatment delivery, evaluation of putative underlying radiobiological mechanisms, and the assessment of genetic and cancer risk following low-dose irradiation will be presented. Radiation therapy of benign diseases is performed according to similar physical principles as those governing treatment of malignant diseases in radiation oncology, using the same techniques and workflows. These methods comprise usage of orthovoltage X-ray units, gamma irradiation facilities, linear accelerators (LINACs), and brachytherapy. Experimental in vitro and in vivo models recently confirmed the clinically observed anti-inflammatory effect of low-dose X-irradiation, and implicated a multitude of radiobiological mechanisms. These include modulation of different immunological pathways, as well as the activities of endothelial cells, mono- and polymorphonuclear leukocytes, and macrophages. The use of effective dose for radiogenic risk assessment and the corresponding tumor incidence rate of 5.5 %/Sv are currently controversially discussed. Some authors argue that the risk of radiation-induced cancers should be estimated on the basis of epidemiological data. However, such data are rarely available at present and associated with high variability. Current radiobiological studies clearly demonstrate a therapeutic effectiveness of radiation therapy used to treat benign diseases and implicate various molecular mechanisms. Radiogenic risks should be taken into account when applying radiation treatment for benign diseases. (orig.) [German] Zusammenfassung des einfuehrenden Kapitels der DEGRO-S2e-Leitlinie zur Strahlentherapie gutartiger Erkrankungen

  12. Learning Physics-based Models in Hydrology under the Framework of Generative Adversarial Networks

    Science.gov (United States)

    Karpatne, A.; Kumar, V.

    2017-12-01

    Generative adversarial networks (GANs), that have been highly successful in a number of applications involving large volumes of labeled and unlabeled data such as computer vision, offer huge potential for modeling the dynamics of physical processes that have been traditionally studied using simulations of physics-based models. While conventional physics-based models use labeled samples of input/output variables for model calibration (estimating the right parametric forms of relationships between variables) or data assimilation (identifying the most likely sequence of system states in dynamical systems), there is a greater opportunity to explore the full power of machine learning (ML) methods (e.g, GANs) for studying physical processes currently suffering from large knowledge gaps, e.g. ground-water flow. However, success in this endeavor requires a principled way of combining the strengths of ML methods with physics-based numerical models that are founded on a wealth of scientific knowledge. This is especially important in scientific domains like hydrology where the number of data samples is small (relative to Internet-scale applications such as image recognition where machine learning methods has found great success), and the physical relationships are complex (high-dimensional) and non-stationary. We will present a series of methods for guiding the learning of GANs using physics-based models, e.g., by using the outputs of physics-based models as input data to the generator-learner framework, and by using physics-based models as generators trained using validation data in the adversarial learning framework. These methods are being developed under the broad paradigm of theory-guided data science that we are developing to integrate scientific knowledge with data science methods for accelerating scientific discovery.

  13. Decision-making in Sport under Mental and Physical Stress

    Directory of Open Access Journals (Sweden)

    Teri J. Hepler

    2015-10-01

    Full Text Available Background: Successful decision-making in sport requires good decisions to be made quickly, but little is understood about the decision process under stress. Objective: The purpose of this study was to compare decision outcomes and the Take the First (TTF heuristic under conditions of mental, physical, and no stress.  Method:  Participants (N=112 were divided into 3 stress groups:  mental stress (mental serial subtraction, physical stress (running on treadmill at 60-70% of maximum effort, and no stress (counting backwards by 1. Participants were exposed to 30 seconds of stress and then watched a video depicting an offensive situation in basketball requiring them to decide what the player with the ball should do next. Each participant performed 10 trials of the video decision-making task.  Results: No differences were found between the 3 stress groups on decision quality, TTF frequency, number of options generated, or quality of first generated option.  However, participants in the no stress and physical stress conditions were faster in generating their first option and making their final decision as compared to the mental stress group.  Conclusion: Overall, results suggest that mental stress impairs decision speed and that TTF is an ecologically rationale heuristic in dynamic, time-pressured situations.  Keywords: Take the first, Heuristic, Pressure, Cognitive performance

  14. Exergy performance of human body under physical activities

    International Nuclear Information System (INIS)

    Mady, Carlos Eduardo Keutenedjian; Albuquerque, Cyro; Fernandes, Tiago Lazzaretti; Hernandez, Arnaldo José; Saldiva, Paulo Hilário Nascimento; Yanagihara, Jurandir Itizo; Oliveira, Silvio de

    2013-01-01

    The aim of this work is to apply performance indicators for individuals under physical activity based on the concepts of exergy destroyed and exergy efficiency. The cardiopulmonary exercise test is one of the most used tests to assess the functional capacity of individuals with varying degrees of physical training. To perform the exergy analysis during the test, it is necessary to calculate heat and mass flow rates, associated with radiation, convection, vaporization and respiration, determined from the measurements and some relations found in the literature. The energy balance allowed the determination of the internal temperature over time and the exergy variation of the body along the experiment. Eventually, it was possible to calculate the destroyed exergy and the exergy efficiency from the exergy analysis. The exergy rates and flow rates are dependent of the exercise level and the body metabolism. The results show that the relation between the destroyed exergy and the metabolism is almost constant during the test, furthermore its value has a great dependence of the subject age. From the exergy analysis it was possible to divide the subjects according to their training level, for the same destroyed exergy, subjects with higher lactate threshold can perform more work. - Highlights: • Exergy analysis was applied to the human body under physical activities. • Concept of maximum available work from ATP hydrolysis was compared with exergy analysis results. • For the same destroyed exergy, subjects with higher lactate threshold can perform more work. • Runners during physical activities tend to a state of minimum destroyed exergy and maximum exergy efficiency

  15. [Principles and methods of mental health resource assessment in military personnel under conditions of demographic crisis].

    Science.gov (United States)

    Vorona, A A; Syrkin, L D

    2011-03-01

    The article is devoted to developing the principles and methods of resource assessment of mental health military contingent in terms of demographic decline and reform of the Armed Forces of the Russian Federation. From the standpoint of the concept of the mutual influence of the value-semantic components and the level of psychological adaptation resources demonstrates the possibility of evaluating resource capabilities of the psyche of military contingent.

  16. Origin of life and the underlying physics of the universe.

    Science.gov (United States)

    Conrad, M

    1997-01-01

    The thesis is put forward that the non-linear self-organizing dynamics of biological systems are inherent in any physical theory that satisfies the requirements of both quantum mechanics and general relativity. Biological life is viewed as an extension of these underlying dynamics rather than as an emergent property of systems that reached a requisite threshold of complexity at a definite point in time. The underlying dynamics are based on interactions between manifest material organizations and an unmanifest vacuum sea whose density structure is isomorphic to the metric structure of space-time. These interactions possess an intrinsic self-corrective character, due to the fact that quantum processes lead to changes in particle states that have a random aspect, while general relativity requires that the distribution of manifest and unmanifest particles be self-consistent. The model implies vacuum hysteretic effects that would bear on nanobiological phenomena and that might be detected through nanobiological techniques.

  17. Molecular Imaging : Computer Reconstruction and Practice - Proceedings of the NATO Advanced Study Institute on Molecular Imaging from Physical Principles to Computer Reconstruction and Practice

    CERN Document Server

    Lemoigne, Yves

    2008-01-01

    This volume collects the lectures presented at the ninth ESI School held at Archamps (FR) in November 2006 and is dedicated to nuclear physics applications in molecular imaging. The lectures focus on the multiple facets of image reconstruction processing and management and illustrate the role of digital imaging in clinical practice. Medical computing and image reconstruction are introduced by analysing the underlying physics principles and their implementation, relevant quality aspects, clinical performance and recent advancements in the field. Several stages of the imaging process are specifically addressed, e.g. optimisation of data acquisition and storage, distributed computing, physiology and detector modelling, computer algorithms for image reconstruction and measurement in tomography applications, for both clinical and biomedical research applications. All topics are presented with didactical language and style, making this book an appropriate reference for students and professionals seeking a comprehen...

  18. Wave-Particle Duality and Uncertainty Principle: Phenomenographic Categories of Description of Tertiary Physics Students' Depictions

    Science.gov (United States)

    Ayene, Mengesha; Kriek, Jeanne; Damtie, Baylie

    2011-01-01

    Quantum mechanics is often thought to be a difficult subject to understand, not only in the complexity of its mathematics but also in its conceptual foundation. In this paper we emphasize students' depictions of the uncertainty principle and wave-particle duality of quantum events, phenomena that could serve as a foundation in building an…

  19. When the uncertainty principle goes up to 11 or how to explain quantum physics with heavy metal

    CERN Document Server

    Moriarty, Philip

    2018-01-01

    There are deep and fascinating links between heavy metal and quantum physics. No, there are. Really. While teaching at the University of Nottingham, physicist Philip Moriarty noticed something odd--a surprising number of his students were heavily into metal music. Colleagues, too: a Venn diagram of physicists and metal fans would show a shocking amount of overlap. What's more, it turns out that heavy metal music is uniquely well-suited to explaining quantum principles. In When the Uncertainty Principle Goes Up to Eleven, Moriarty explains the mysteries of the universe's inner workings via drum beats and feedback: You'll discover how the Heisenberg uncertainty principle comes into play with every chugging guitar riff, what wave interference has to do with Iron Maiden, and why metalheads in mosh pits behave just like molecules in a gas. If you're a metal fan trying to grasp the complexities of quantum physics, a quantum physicist baffled by heavy metal, or just someone who'd like to know how the fundamental sci...

  20. Serving the Reich the struggle for the soul of physics under Hitler

    CERN Document Server

    Ball, Philip

    2013-01-01

    Serving the Reich tells the story of physics under Hitler. While some scientists tried to create an Aryan physics that excluded any 'Jewish ideas', many others made compromises and concessions as they continued to work under the Nazi regime. Among them were three world-renowned physicists: Max Planck, pioneer of quantum theory, regarded it as his moral duty to carry on under the regime. Peter Debye, a Dutch physicist, rose to run the Reich's most important research institute before leaving for the United States in 1940. Werner Heisenberg, discovered the Uncertainty Principle, and became the leading figure in Germany's race for the atomic bomb. After the war most scientists in Germany maintained they had been apolitical or even resisted the regime: Debye claimed that he had gone to America to escape Nazi interference in his research; Heisenberg and others argued that they had deliberately delayed production of the atomic bomb. Mixing history, science and biography, Serving the Reich is a gripping exploration o...

  1. Vibroacoustic response of panels under diffuse acoustic field excitation from sensitivity functions and reciprocity principles.

    Science.gov (United States)

    Marchetto, Christophe; Maxit, Laurent; Robin, Olivier; Berry, Alain

    2017-06-01

    This paper aims at developing an experimental method to characterize the vibroacoustic response of a panel to a diffuse acoustic field (DAF) excitation with a different laboratory setup than those used in standards (i.e., coupled rooms). The proposed methodology is based on a theoretical model of the DAF and on the measurement of the panel's sensitivity functions, which characterize its vibroacoustic response to wall plane waves. These functions can be estimated experimentally using variations of the reciprocity principle, which are described in the present paper. These principles can either be applied for characterizing the structural response by exciting the panel with a normal force at the point of interest or for characterizing the acoustic response (radiated pressure, acoustic intensity) by exciting the panel with a monopole and a dipole source. For both applications, the validity of the proposed approach is numerically and experimentally verified on a test case composed of a baffled simply supported plate. An implementation for estimating the sound transmission loss of the plate is finally proposed. The results are discussed and compared with measurements performed in a coupled anechoic-reverberant room facility following standards.

  2. General Principles for the welfare of animals in production systems: the underlying science and its application.

    Science.gov (United States)

    Fraser, David; Duncan, Ian J H; Edwards, Sandra A; Grandin, Temple; Gregory, Neville G; Guyonnet, Vincent; Hemsworth, Paul H; Huertas, Stella M; Huzzey, Juliana M; Mellor, David J; Mench, Joy A; Spinka, Marek; Whay, H Rebecca

    2013-10-01

    In 2012, the World Organisation for Animal Health adopted 10 'General Principles for the Welfare of Animals in Livestock Production Systems' to guide the development of animal welfare standards. The General Principles draw on half a century of scientific research relevant to animal welfare: (1) how genetic selection affects animal health, behaviour and temperament; (2) how the environment influences injuries and the transmission of diseases and parasites; (3) how the environment affects resting, movement and the performance of natural behaviour; (4) the management of groups to minimize conflict and allow positive social contact; (5) the effects of air quality, temperature and humidity on animal health and comfort; (6) ensuring access to feed and water suited to the animals' needs and adaptations; (7) prevention and control of diseases and parasites, with humane euthanasia if treatment is not feasible or recovery is unlikely; (8) prevention and management of pain; (9) creation of positive human-animal relationships; and (10) ensuring adequate skill and knowledge among animal handlers. Research directed at animal welfare, drawing on animal behaviour, stress physiology, veterinary epidemiology and other fields, complements more established fields of animal and veterinary science and helps to create a more comprehensive scientific basis for animal care and management. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Principles of Play: A Proposed Framework towards a Holistic Overview of Games in Primary Physical Education

    Science.gov (United States)

    Ward, Gavin; Griggs, Gerald

    2011-01-01

    The playing of games has been a long standing tradition in physical education. Yet despite its history, the teaching of games within primary physical education lessons remains something of a weakness. This is most evident through a continued focus upon skill acquisition and a lack of fostering of a real "tactical understanding" of game…

  4. Martensitic fcc-to-hcp transformations in solid xenon under pressure: a first-principles study.

    Science.gov (United States)

    Kim, Eunja; Nicol, Malcolm; Cynn, Hyunchae; Yoo, Choong-Shik

    2006-01-27

    First-principles calculations reveal that the fcc-to-hcp pressure-induced transformation in solid xenon proceeds through two mechanisms between 5 and 70 GPa. The dynamics of the phase transition involves a sluggish stacking-disorder growth at lower pressures (path I) that changes to a path involving an orthorhombic distortion at higher pressures (path II). The switchover is governed by a delicate interplay of energetics (enthalpy of the system for the structural stability) and kinetics (energy barrier for the transition). The two types of martensitic transformations involved in this pressure-induced structural transformation are a twinned martensitic transition at lower pressures and a slipped martensitic transition at higher pressures.

  5. Optimisation of structural shielding of accelerator control room for compliance with ALARA principle under Indian conditions

    International Nuclear Information System (INIS)

    Ahmad, Masood; Singh, Brijesh

    1999-01-01

    The case of a 20 MV x-ray accelerator has been considered in this paper for optimisation. An internationally recommended value of α = US$ 1000 per person-sievert has been assumed. Cost of concrete has been assumed as US$ 82.7/m 3 . It is seen that, extra shielding is needed to satisfy the ALARA principle. Further, the amount of requisite shielding increases with the degree of occupancy and, also, if the local construction materials or the labour are cheaper than considered in this paper. Accordingly 1.5 to 4.75 HVLs may be needed as extra shielding in different situations. Therefore, a site specific and installation specific optimisation of shielding is necessary

  6. First-principles calculations of structure and elasticity of hydrous fayalite under high pressure

    Science.gov (United States)

    Zhang, Chuan-Yu; Wang, Xu-Ben; Zhao, Xiao-Feng; Chen, Xing-Run; Yu, You; Tian, Xiao-Feng

    2017-12-01

    Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 11404042 and 11604029), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20135122120010), and the Open Research Fund of Computational Physics Key Laboratory of Sichuan Province, Yibin University (Grant No. JSWL2015KFZ02).

  7. Exploration of stable stoichiometries, physical properties and hardness in the Rh–Si system: a first-principles study

    OpenAIRE

    Wang, Jing-Jing; Hermann, Andreas; Kuang, Xiao-Yu; Jin, Yuan-Yuan; Lu, Cheng; Zhang, Chuan-Zhao; Ju, Meng; Si, Meng-Ting; Iitaka, Toshiaki

    2015-01-01

    To understand the structural stability, physical properties, and hardness of the Rh–Si system, we have performed systematic first-principles crystal structure searches for various stoichiometries of rhodium silicides, utilizing the particle swarm optimization method. A new stable stoichiometry, Rh4Si5 with space group P21/m, has been found at atmospheric pressure, complementing the three well-known rhodium silicides of Rh2Si (Pnma), Rh5Si3 (Pbam), and RhSi (Pnma). Our calculations of the stru...

  8. First-principles investigations of the physical properties of RCd (R=Ce, La, Pr, Nd)

    Science.gov (United States)

    Long, Jianping

    2012-12-01

    The crystal structural, electronic, elastic and the thermodynamic properties of RCd are investigated by using the first-principles plane-wave pseudopotential density function theory within the generalized gradient approximation (GGA). The calculated equilibrium lattice parameters for RCd are in good agreement with the available experimental data. Furthermore, the optical properties, namely the dielectric function, refractive index and electron energy loss are reported for radiation up to 30 eV. Finally, the elastic properties, the bulk modulus and the Debye temperature of RCd are given for reference.

  9. First-principles investigations of the physical properties of RCd (R=Ce, La, Pr, Nd)

    Energy Technology Data Exchange (ETDEWEB)

    Long Jianping, E-mail: jianpinglong@cdut.cn [College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059 (China)

    2012-12-15

    The crystal structural, electronic, elastic and the thermodynamic properties of RCd are investigated by using the first-principles plane-wave pseudopotential density function theory within the generalized gradient approximation (GGA). The calculated equilibrium lattice parameters for RCd are in good agreement with the available experimental data. Furthermore, the optical properties, namely the dielectric function, refractive index and electron energy loss are reported for radiation up to 30 eV. Finally, the elastic properties, the bulk modulus and the Debye temperature of RCd are given for reference.

  10. Practical application of the ALARA principle in management of the nuclear legacy: optimization under uncertainty

    International Nuclear Information System (INIS)

    Smith, Graham; Sneve, Malgorzata K.

    2008-01-01

    Full text: Radiological protection has a long and distinguished history in taking a balanced approach to optimization. Both utilitarian and individual interests and perspectives are addressed through a process of constrained optimisation, with optimisation intended to lead to the most benefit to the most people, and constraints being operative to limit the degree of inequity among the individuals exposed. At least, expressed simplistically, that is what the recommendations on protection are intended to achieve. This paper examines the difficulties in achieving that objective, based on consideration of the active role of optimisation in regulatory supervision of the historic nuclear legacy. This example is chosen because the application of the ALARA principle has important implications for some very major projects whose objective is remediation of existing legacy facilities. But it is also relevant because timely, effective and cost efficient completion of those projects has implications for confidence in the future development of nuclear power and other uses of radioactive materials. It is also an interesting example because legacy management includes mitigation of some major short and long term hazards, but those mitigating measures themselves involve operations with their own risk, cost and benefit profiles. Like any other complex activity, a legacy management project has to be broken down into logistically feasible parts. However, from a regulatory perspective, simultaneous application of ALARA to worker protection, major accident risk mitigation and long-term environmental and human health protection presents its own challenges. Major uncertainties which exacerbate the problem arise from ill-characterised source terms, estimation of the likelihood of unlikely failures in operational processes, and prospective assessment of radiological impacts over many hundreds of years and longer. The projects themselves are set to run over decades, during which time the

  11. On the use, by Einstein, of the principle of dimensional homogeneity, in three problems of the physics of solids

    Directory of Open Access Journals (Sweden)

    FERNANDO L. LOBO B. CARNEIRO

    2000-12-01

    Full Text Available Einstein, in 1911, published an article on the application of the principle of dimensional homogeneity to three problems of the physics of solids: the characteristic frequency of the atomic nets of crystalline solids as a function of their moduli of compressibility or of their melting points, and the thermal conductivity of crystalline insulators. Recognizing that the physical dimensions of temperature are not the same as those of energy and heat, Einstein had recourse to the artifice of replace that physical parameter by its product by the Boltzmann constant, so obtaining correct results. But nowadays, with the new basic quantities "Thermodynamic Temperature theta (unit- Kelvin'', "Electric Current I (unit Ampère'' and "Amount of Substance MOL (unit-mole'', incorporated to the SI International System of Units, in 1960 and 1971, the same results are obtained in a more direct and coherent way. At the time of Einstein's article only three basic physical quantities were considered - length L, mass M, and time T. He ignored the pi theorem of dimensional analysis diffused by Buckingham three years later, and obtained the "pi numbers'' by trial and error. In the present paper is presented a revisitation of the article of Einstein, conducted by the modern methodology of dimensional analysis and theory of physical similitude.

  12. Physical and Temporal Characteristics of Under 19, Under 21 and Senior Male Beach Volleyball Players

    Directory of Open Access Journals (Sweden)

    Alexandre Medeiros, Rui Marcelino, Isabel Mesquita, José Manuel Palao

    2014-09-01

    Full Text Available This study aimed to assess the effects of age groups and players’ role (blocker vs. defender specialist in beach volleyball in relation to physical and temporal variables, considering quality of opposition. 1101 rallies from Under 19 (U19, 933 rallies from Under 21 (U21, and 1480 rallies from senior (senior (Men’s Swatch World Championships, 2010-2011 were observed using video match analysis. Cluster analysis was used to set teams’ competitive levels and establish quality of opposition as “balanced”, “moderate balanced” and “unbalanced” games. The analyzed variables were: temporal (duration of set, total rest time, total work time, duration of rallies, rest time between rallies and physical (number of jumps and number of hits done by defenders and blockers characteristics. A one-way ANOVA, independent samples t-test and multinomial logistic regression were performed to analyze the variables studied. The analysis of temporal and physical characteristics showed differences considering age group, player’s role and quality of opposition. The duration of set, total rest time, and number of jumps done by defenders significantly increased from the U19 to senior category. Multinomial logistic regression showed that in: a balanced games, rest time between rallies was higher in seniors than in U19 or U21; number of jumps done by defenders was higher in seniors than in U19 and U21; b moderate balanced games, number of jumps done by defenders was higher in seniors than in U21 and number of jumps done by blockers was smaller in U19 than U21 or seniors; c unbalanced games, no significant findings were shown. This study suggests differences in players’ performances according to age group and players’ role in different qualities of opposition. The article provides reference values that can be useful to guide training and create scenarios that resemble a competition, taking into account physical and temporal characteristics.

  13. Foundations & principles of distributed manufacturing elements of manufacturing networks, cyber-physical production systems and smart automation

    CERN Document Server

    Kühnle, Hermann

    2015-01-01

    The book presents a coherent description of distributed manufacturing, providing a solid base for further research on the subject as well as smart implementations in companies. It provides a guide for those researching and working in a range of fields, such as smart manufacturing, cloud computing, RFID tracking, distributed automation, cyber physical production and global design anywhere, manufacture anywhere solutions. Foundations & Principles of Distributed Manufacturing anticipates future advances in the fields of embedded systems, the Internet of Things and cyber physical systems, outlining how adopting these innovations could rapidly bring about improvements in key performance indicators, which could in turn generate competition pressure by rendering successful business models obsolete. In laying the groundwork for powerful theoretical models, high standards for the homogeneity and soundness of the suggested setups are applied. The book especially elaborates on the upcoming competition in online manu...

  14. The first-principles calculations for the elastic properties of Zr2Al under compression

    International Nuclear Information System (INIS)

    Yuan Xiaoli; Wei Dongqing; Chen Xiangrong; Zhang Qingming; Gong Zizheng

    2011-01-01

    Graphical abstract: The calculated elastic constants C ij as a function of pressure P. Display Omitted Research highlights: → It is found that the five independent elastic constants increase monotonically with pressure. C 11 and C 33 vary rapidly as pressure increases, C 13 and C 12 becomes moderate. However, C 44 increases comparatively slowly with pressure. Figure shows excellent satisfaction of the calculated elastic constants of Zr 2 Al to these equations and hence in our calculation, the Zr 2 Al is mechanically stable at pressure up to 100 GPa. - Abstract: The first-principles calculations were applied to investigate the structural, elastic constants of Zr 2 Al alloy with increasing pressure. These properties are based on the plane wave pseudopotential density functional theory (DFT) method within the generalized gradient approximation (GGA) for exchange and correlation. The result of the heat of formation of Zr 2 Al crystal investigated is in excellent consistent with results from other study. The anisotropy, the shear modulus, and Young's modulus for the ideal polycrystalline Zr 2 Al are also studied. It is found that (higher) pressure can significantly improve the ductility of Zr 2 Al. Moreover, the elastic constants of Zr 2 Al increase monotonically and the anisotropies decrease with the increasing pressure. Finally, it is observed that Zr d electrons are mainly contributed to the density of states at the Fermi level.

  15. Physical and temporal characteristics of under 19, under 21 and senior male beach volleyball players.

    Science.gov (United States)

    Medeiros, Alexandre; Marcelino, Rui; Mesquita, Isabel; Palao, José Manuel

    2014-09-01

    This study aimed to assess the effects of age groups and players' role (blocker vs. defender specialist) in beach volleyball in relation to physical and temporal variables, considering quality of opposition. 1101 rallies from Under 19 (U19), 933 rallies from Under 21 (U21), and 1480 rallies from senior (senior) (Men's Swatch World Championships, 2010-2011) were observed using video match analysis. Cluster analysis was used to set teams' competitive levels and establish quality of opposition as "balanced", "moderate balanced" and "unbalanced" games. The analyzed variables were: temporal (duration of set, total rest time, total work time, duration of rallies, rest time between rallies) and physical (number of jumps and number of hits done by defenders and blockers) characteristics. A one-way ANOVA, independent samples t-test and multinomial logistic regression were performed to analyze the variables studied. The analysis of temporal and physical characteristics showed differences considering age group, player's role and quality of opposition. The duration of set, total rest time, and number of jumps done by defenders significantly increased from the U19 to senior category. Multinomial logistic regression showed that in: a) balanced games, rest time between rallies was higher in seniors than in U19 or U21; number of jumps done by defenders was higher in seniors than in U19) and U21; b) moderate balanced games, number of jumps done by defenders was higher in seniors than in U21 and number of jumps done by blockers was smaller in U19 than U21 or seniors; c) unbalanced games, no significant findings were shown. This study suggests differences in players' performances according to age group and players' role in different qualities of opposition. The article provides reference values that can be useful to guide training and create scenarios that resemble a competition, taking into account physical and temporal characteristics. Key PointsPlayer roles, quality of opposition

  16. Differences between the family-centered "COPCA" program and traditional infant physical therapy based on neurodevelopmental treatment principles.

    Science.gov (United States)

    Dirks, Tineke; Blauw-Hospers, Cornill H; Hulshof, Lily J; Hadders-Algra, Mijna

    2011-09-01

    Evidence for effectiveness of pediatric physical therapy in infants at high risk for developmental motor disorders is limited. Therefore, "Coping With and Caring for Infants With Special Needs" (COPCA), a family-centered, early intervention program, was developed. The COPCA program is based on 2 components: (1) family involvement and educational parenting and (2) the neuromotor principles of the neuronal group selection theory. The COPCA coach uses principles of coaching to encourage the family's own capacities for solving problems of daily care and incorporating variation, along with trial and error in daily activities. The purpose of this study was to evaluate whether the content of sessions of the home-based, early intervention COPCA program differs from that of traditional infant physical therapy (TIP) sessions, which in the Netherlands are largely based on neurodevelopmental treatment. The study was conducted at the University Medical Center Groningen in the Netherlands. A quantitative video analysis of therapy sessions was conducted with infants participating in a 2-arm randomized trial. Forty-six infants at high risk for developmental motor disorders were randomly assigned to receive COPCA (n=21) or TIP (n=25) between 3 and 6 months corrected age. Intervention sessions were videotaped at 4 and 6 months corrected age and analyzed with a standardized observation protocol for the classification of physical therapy actions. Outcome parameters were relative amounts of time spent on specific physical therapy actions. The content of COPCA and TIP differed substantially. For instance, in TIP sessions, more time was spent on facilitation techniques, including handling, than in COPCA sessions (29% versus 3%, respectively). During COPCA, more time was spent on family coaching and education than during TIP (16% versus 4%, respectively). The major limitation of the study was its restriction to the Netherlands, implying that findings cannot be generalized automatically to

  17. Essential concepts and underlying theories from physics, chemistry, and mathematics for "biochemistry and molecular biology" majors.

    Science.gov (United States)

    Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry, and Mathematics that all Biochemistry or Molecular Biology majors must understand to complete their major coursework. The allied fields working group created a survey to validate foundational concepts from Physics, Chemistry, and Mathematics identified from participant feedback at various workshops. One-hundred twenty participants responded to the survey and 68% of the respondents answered yes to the question: "We have identified the following as the core concepts and underlying theories from Physics, Chemistry, and Mathematics that Biochemistry majors or Molecular Biology majors need to understand after they complete their major courses: 1) mechanical concepts from Physics, 2) energy and thermodynamic concepts from Physics, 3) critical concepts of structure from chemistry, 4) critical concepts of reactions from Chemistry, and 5) essential Mathematics. In your opinion, is the above list complete?" Respondents also delineated subcategories they felt should be included in these broad categories. From the results of the survey and this analysis the allied fields working group constructed a consensus list of allied fields concepts, which will help inform Biochemistry and Molecular Biology educators when considering the ASBMB recommended curriculum for Biochemistry or Molecular Biology majors and in the development of appropriate assessment tools to gauge student understanding of how these concepts relate to biochemistry and molecular biology. © 2013 by The International Union of Biochemistry and Molecular Biology.

  18. Security and privacy in cyber-physical systems foundations, principles, and applications

    CERN Document Server

    Song, Houbing; Jeschke, Sabina

    2017-01-01

    Written by a team of experts at the forefront of the cyber-physical systems (CPS) revolution, this book provides an in-depth look at security and privacy, two of the most critical challenges facing both the CPS research and development community and ICT professionals. It explores, in depth, the key technical, social, and legal issues at stake, and it provides readers with the information they need to advance research and development in this exciting area. Cyber-physical systems (CPS) are engineered systems that are built from, and depend upon the seamless integration of computational algorithms and physical components. Advances in CPS will enable capability, adaptability, scalability, resiliency, safety, security, and usability far in excess of what today's simple embedded systems can provide. Just as the Internet revolutionized the way we interact with information, CPS technology has already begun to transform the way people interact with engineered systems. In the years ahead, smart CPS will drive innovat...

  19. Solid-State Physics An Introduction to Principles of Materials Science

    CERN Document Server

    Ibach, Harald

    2009-01-01

    This new edition of the popular introduction to solid-state physics provides a comprehensive overview on basic theoretical and experimental concepts of material science. Additional sections emphasize current topics in solid-state physics. Notably, sections on important devices, aspects of non-periodic structures of matter, phase transitions, defects, superconductors and nanostructures have been added, the chapters presenting semi- and superconductivity had been completly updated. Students will benefit significantly from solving the exercises given at the end of each chapter. This book is intended for university students in physics, engineering and electrical engineering. This edition has been carefully revised, updated, and enlarged. Among the key recent developments incorporated throughout GMR (giant magneto resistance), thin-film magnetic properties, magnetic hysteresis and domain walls, quantum transport, metamaterials, and preparation techniques for nanostructures. From a review of the original edition �...

  20. The physics of degradation in engineered materials and devices fundamentals and principles

    CERN Document Server

    Swingler, Jonathan

    2015-01-01

    Degradation is apparent in all things and is fundamental to both manufactured and natural objects. It is often described by the second law of thermodynamics, where entropy, a measure of disorder, tends to increase with time in a closed system. Things age! This concise reference work brings together experts and key players engaged in the physics of degradation to present the background science, current thinking and developments in understanding, and gives a detailed account of emerging issues across a selection of engineering applications. The work has been put together to equip the upper level undergraduate student, postgraduate student, as well as the professional engineer and scientist, in the importance of physics of degradation. The aim of The Physics of Degradation in Engineered Materials and Devices is to bridge the gap between published textbooks on the fundamental science of degradation phenomena and published research on the engineering science of actual fabricated materials and devices. A history o...

  1. Principles and applications of a neutral current detector for neutrino physics and astronomy

    International Nuclear Information System (INIS)

    Drukier, A.; Stodolsky, L.

    1982-01-01

    We study neutrino detection through the elastic scattering of neutrinos on nuclei and identification of the recoil energy. The very large value of the cross section compared to previous methods indicates a detector would be relatively light and suggests the possibility of a true 'neutrino observatory'. We examine a realization in terms of the superconducting grain idea, which appears in principle feasible through extension and extrapolation of presently known techniques. Such a detector would permit determination of the neutrino spectrum and should be intensive to neutrino oscillations. Various applications and tests are discussed, including spallation sources, reactors, supernovas, solar and terrestrial neutrinos. A supernova would permit a simple determination of the number of neutrinos and their masses, while for solar neutrinos rates of thousands of S.N.U. are theoretically attainable. A preliminary estimate of the most difficult backgrounds is attempted. (orig.)

  2. USEFUL: Ultrasound Exam for Underlying Lesions Incorporated into Physical Exam

    Directory of Open Access Journals (Sweden)

    Jon Steller

    2014-05-01

    Full Text Available Introduction: The Ultrasound Screening Exam for Underlying Lesions (USEFUL was developed in an attempt to establish a role for bedside ultrasound in the primary and preventive care setting. It is the purpose of our pilot study to determine if students were first capable of performing all of the various scans required of our USEFUL while defining such an ultrasound-assisted physical exam that would supplement the standard hands-on physical exam in the same head-to-toe structure. We also aimed to assess the time needed for an adequate exam and analyze if times improved with repetition and previous ultrasound training. Methods: Medical students with ranging levels of ultrasound training received a 25-minute presentation on our USEFUL followed by a 30-minute hands-on session. Following the hands-on session, the students were asked to perform a timed USEFUL on 2-3 standardized subjects. All images were documented as normal or abnormal with the understanding that an official detailed exam would be performed if an abnormality were to be found. All images were read and deemed adequate by board eligible emergency medicine ultrasound fellows. Results: Twenty-six exams were performed by 9 students. The average time spent by all students per USEFUL was 11 minutes and 19 seconds. Students who had received the University of California, Irvine School of Medicine’s integrated ultrasound curriculum performed the USEFUL significantly faster (p< 0.0025. The time it took to complete the USEFUL ranged from 6 minutes and 32 seconds to 17 minutes, and improvement was seen with each USEFUL performed. The average time to complete the USEFUL on the first standardized patient was 13 minutes and 20 seconds, while 11 minutes and 2 seconds, and 9 minutes and 20 seconds were spent performing the exam on the second and third patient, respectively. Conclusion: Students were able to effectively complete all scans required by the USEFUL in a timely manner. Students who have

  3. Comparative assessment of Japan's long-term carbon budget under different effort-sharing principles

    NARCIS (Netherlands)

    Kuramochi, Takeshi; Asuka, Jusen; Fekete, Hanna; Tamura, Kentaro; Höhne, Niklas

    2016-01-01

    This article assesses Japan's carbon budgets up to 2100 in the global efforts to achieve the 2 °C target under different effort-sharing approaches based on long-term GHG mitigation scenarios published in 13 studies. The article also presents exemplary emission trajectories for Japan to stay

  4. Principles of astrophysics using gravity and stellar physics to explore the cosmos

    CERN Document Server

    Keeton, Charles

    2014-01-01

    This book gives a survey of astrophysics at the advanced undergraduate level.  It originates from a two-semester course sequence at Rutgers University that is meant to appeal not only to astrophysics students but also more broadly to physics and engineering students.  The organization is driven more by physics than by astronomy; in other words, topics are first developed in physics and then applied to astronomical systems that can be investigated, rather than the other way around. The first half of the book focuses on gravity.  Gravity is the dominant force in many astronomical systems, so a tremendous amount can be learned by studying gravity, motion and mass.  The theme in this part of the book, as well as throughout astrophysics, is using motion to investigate mass.  The goal of Chapters 2-11 is to develop a progressively richer understanding of gravity as it applies to objects ranging from planets and moons to galaxies and the universe as a whole. The second half uses other aspects of physics to addr...

  5. The structural, mechanical, and electronic properties of LiAlB{sub 4} under pressure from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Tayran, Ceren; Aydin, Sezgin [Department of Physics, Sciences Faculty, Gazi University, 06500, Ankara (Turkey)

    2017-05-15

    The structural, elastic, mechanical, and electronic properties of lithium aluminum tetraboride (LiAlB{sub 4}) under hydrostatic pressure have been investigated by using first-principles density functional theory calculations. The effects of pressure on the lattice parameters, volume, and bond lengths are studied. It is indicated from the calculated elastic constants that LiAlB{sub 4} compound is mechanically stable on 0-40 GPa pressure range. And, by means of these elastic constants set, some mechanical properties such as bulk, shear and Young's moduli, and then Poisson's ratio are determined as a function of pressure. Also, the ductile or brittle nature of LiAlB{sub 4} is examined. Additionally, using the first-principles data obtained from the geometry optimizations, the hardness of LiAlB{sub 4} is calculated, and its nature is investigated under pressure. Furthermore, in order to reveal the effects of pressure on the electronic and binding behavior of the compound, band structures, total and partial density of states, charge densities, Mulliken atomic charges, and bond overlap populations are searched as a function of pressure. To check the stability of the compound, phonon dispersion curves are calculated. And, the results are compared with the other convenient borides. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Influence of music on memory and education, and the application of its underlying principles to acupuncture.

    Science.gov (United States)

    Seki, H

    1983-01-01

    The interrelations among learning, brain waves, music and the relief of pain by acupuncture are discussed from the standpoint of an educator, who has some practical experience in suggestive-accelerative learning and teaching (S.A.L.T.). Through the diverse fields of science, e.g. educational psychology, physiology, electronics and acoustics, the principal law governing the l/f fluctuations (where f is frequency), or the inverse frequency distribution of the power spectrum, seems to play an important role in their phenomenological mechanism. The author totally explained in this paper such relations and he arranged the related phenomena into physical, physiological, psychological and pedagogical fields. Finally, he referred to an interesting example of the application of l/f fluctuations to the relief of pain by acupuncture.

  7. Order-of-magnitude physics of neutron stars. Estimating their properties from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Reisenegger, Andreas; Zepeda, Felipe S. [Pontificia Universidad Catolica de Chile, Instituto de Astrofisica, Facultad de Fisica, Macul (Chile)

    2016-03-15

    We use basic physics and simple mathematics accessible to advanced undergraduate students to estimate the main properties of neutron stars. We set the stage and introduce relevant concepts by discussing the properties of ''everyday'' matter on Earth, degenerate Fermi gases, white dwarfs, and scaling relations of stellar properties with polytropic equations of state. Then, we discuss various physical ingredients relevant for neutron stars and how they can be combined in order to obtain a couple of different simple estimates of their maximum mass, beyond which they would collapse, turning into black holes. Finally, we use the basic structural parameters of neutron stars to briefly discuss their rotational and electromagnetic properties. (orig.)

  8. A covariant action principle for dissipative fluid dynamics: from formalism to fundamental physics

    International Nuclear Information System (INIS)

    Andersson, N; Comer, G L

    2015-01-01

    We present a new variational framework for dissipative general relativistic fluid dynamics. The model extends the convective variational principle for multi-fluid systems to account for a range of dissipation channels. The key ingredients in the construction are (i) the use of a lower dimensional matter space for each fluid component, and (ii) an extended functional dependence for the associated volume forms. In an effort to make the concepts clear, the formalism is developed step-by-step with model examples considered at each level. Thus we consider a model for heat flow, derive the relativistic Navier-Stokes equations and discuss why the individual dissipative stress tensors need not be spacetime symmetric. We argue that the new formalism, which notably does not involve an expansion away from an assumed equilibrium state, provides a conceptual breakthrough in this area of research. We also provide an ambitious list of directions in which one may want to extend it in the future. This involves an exciting set of problems, relating to both applications and foundational issues. (paper)

  9. New crystal structure and physical properties of TcB from first-principles calculations

    Science.gov (United States)

    Zhang, Gang-Tai; Bai, Ting-Ting; Yan, Hai-Yan; Zhao, Ya-Ru

    2015-10-01

    By combining first-principles calculations with the particle swarm optimization algorithm, we predicted a hexagonal structure for TcB, which is energetically more favorable than the previously reported WC-type and Cmcm structures. The new phase is mechanically and dynamically stable, as confirmed by its phonon and elastic constants calculations. The calculated mechanical properties show that it is an ultra-incompressible and hard material. Meanwhile, the elastic anisotropy is investigated by the shear anisotropic factors and ratio of the directional bulk modulus. Density of states analysis reveals that the strong covalent bonding between Tc and B atoms plays a leading role in forming a hard material. Additionally, the compressibility, bulk modulus, Debye temperature, Grüneisen parameter, specific heat, and thermal expansion coefficient of TcB are also successfully obtained by using the quasi-harmonic Debye model. Project supported by the Science Foundation of Baoji University of Arts and Sciences of China (Grant No. ZK11061) and the Natural Science Foundation of the Education Committee of Shaanxi Province, China (Grant Nos. 2013JK0637, 2013JK0638, and 2014JK1044).

  10. A First-Principles Comparison of CsI and Xe Under Shock Compression

    Science.gov (United States)

    Diamond, M. R.; Jeanloz, R.; Militzer, B.

    2016-12-01

    Cesium iodide and xenon, isoelectronic (same number of electrons per atom) moderately high-Z compounds, are known to exhibit similar behaviors at high pressure, notably in their cold-compression equations of state[1, 2] and band gap closure pressures[3-6]. With such drastically different chemical bonding properties under ambient conditions, this salt and noble gas serve as a quintessential analog pair for high pressure science. In addition to practical benefit of understanding analogs for experimental extrapolations, investigating these materials under extreme conditions helps build a fundamental understanding of the relationship between thermodynamics and condensed matter. To better investigate those high pressure states which are at high temperature, as well as to allow for comparison to shock experiments, we have used density functional theory (DFT) calculations combined with molecular dynamics (MD) simulations to calculate high temperature/density pressures, internal energies, and band gaps along the Hugoniots (shock equations of state) of CsI and Xe up to 10,000 K. Since CsI is a solid at ambient conditions, we used its ambient density as its starting density for the Hugoniot calculation. For the starting density of Xe, we chose both its zero-pressure zero-temperature value and a value equal to the molar density of CsI, to construct two separate Hugoniots.

  11. High-temperature superconducting phase of HBr under pressure predicted by first-principles calculations

    Science.gov (United States)

    Gu, Qinyan; Lu, Pengchao; Xia, Kang; Sun, Jian; Xing, Dingyu

    2017-08-01

    The high pressure phases of HBr are explored with an ab initio crystal structure search. By taking into account the contribution of zero-point energy (ZPE), we find that the P 4 /n m m phase of HBr is thermodynamically stable in the pressure range from 150 to 200 GPa. The superconducting critical temperature (Tc) of P 4 /n m m HBr is evaluated to be around 73 K at 170 GPa, which is the highest record so far among binary halogen hydrides. Its Tc can be further raised to around 95K under 170 GPa if half of the bromine atoms in the P 4 /n m m HBr are substituted by the lighter chlorine atoms. Our study shows that, in addition to lower mass, higher coordination number, shorter bonds, and more highly symmetric environment for the hydrogen atoms are important factors to enhance the superconductivity in hydrides.

  12. Towards nearly zero-energy buildings. Definition of common principles under the EPBD. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hermelink, A.; Schimschar, S.; Boermans, T. [Ecofys, Utrecht (Netherlands); Pagliano, L.; Zangheri, P.; Armani, R. [Energy Department, Politecnico di Milano, Milan (Italy); Voss, K.; Musall, E. [University of Wuppertal, Wuppertal (Germany)

    2013-02-15

    Europe aims at bringing about drastic reductions of greenhouse gas emissions in the residential and service sectors of about 90% compared to 1990 by 2050. Nearly Zero-Energy Buildings are a major element of European climate policy. Already by 2021, every new building in Europe has to meet this standard. During 2012, a consortium led by Ecofys undertook a study for the European Commission to provide more guidance to Member States and the Commission with regards to the implementation of the requirements for nearly zero-energy buildings under the EPBD. The study features benchmarks for nearly zero-energy buildings for different European climates, an analytical framework for evaluating Member States national plans for increasing the number of nearly zero energy buildings, a reporting template for these plans and an analysis of the convergence between cost optimal levels and nearly zero-energy buildings.

  13. From Random Walks to Brownian Motion, from Diffusion to Entropy: Statistical Principles in Introductory Physics

    Science.gov (United States)

    Reeves, Mark

    2014-03-01

    Entropy changes underlie the physics that dominates biological interactions. Indeed, introductory biology courses often begin with an exploration of the qualities of water that are important to living systems. However, one idea that is not explicitly addressed in most introductory physics or biology textbooks is dominant contribution of the entropy in driving important biological processes towards equilibrium. From diffusion to cell-membrane formation, to electrostatic binding in protein folding, to the functioning of nerve cells, entropic effects often act to counterbalance deterministic forces such as electrostatic attraction and in so doing, allow for effective molecular signaling. A small group of biology, biophysics and computer science faculty have worked together for the past five years to develop curricular modules (based on SCALEUP pedagogy) that enable students to create models of stochastic and deterministic processes. Our students are first-year engineering and science students in the calculus-based physics course and they are not expected to know biology beyond the high-school level. In our class, they learn to reduce seemingly complex biological processes and structures to be described by tractable models that include deterministic processes and simple probabilistic inference. The students test these models in simulations and in laboratory experiments that are biologically relevant. The students are challenged to bridge the gap between statistical parameterization of their data (mean and standard deviation) and simple model-building by inference. This allows the students to quantitatively describe realistic cellular processes such as diffusion, ionic transport, and ligand-receptor binding. Moreover, the students confront ``random'' forces and traditional forces in problems, simulations, and in laboratory exploration throughout the year-long course as they move from traditional kinematics through thermodynamics to electrostatic interactions. This talk

  14. The viper fangs: clinical anatomy, principles of physical examination and therapy (a review

    Directory of Open Access Journals (Sweden)

    Matteo Oliveri

    2016-01-01

    Full Text Available The assessment of fangs is a fundamental part of clinical examination of viperid snakes. The long curved venom fang is carried by short, highly mobile maxilla. Short anaesthesia is advised for safe physical examination and radiography of the mouth cavity. The fangs are gently forced outside the fang pocket by passing the bar or forceps on the palato-maxillary arch, and rotating them rostrally shifting the mucosal fold. Functional fangs are periodically shed and several generations of replacement teeth lie behind and beneath each fang. In case of fang fracture, therapy should be limited to flushing with a solution of chlorhexidine or povidone iodine, and topical application of pro-coagulant and antibacterial cream. Therapy of chronic fang inflammation is based on removal of necrotized fang and repeated abundant irrigation of the fang pocket. Treatment of chronic stomatitis consists of flushing with chlorhexidine or povidone iodine, physical removal of the plaques, administration of analgesics and antibiotics (marbofloxacin, enrofloxacin or ceftazidime. Extra-oral surgical approach is the best method for odontogenic abscess removal. A vigorous flushing with sterile saline solution, chlorhexidine and povidone iodine and topical application of antibiotics (antibiotic embedded surgical sponge is advised. Force feeding of the anorectic patient suffering from fang inflammation is a mandatory part of the standard treatment protocol.

  15. TOPICAL REVIEW: Ultrasound contrast microbubbles in imaging and therapy: physical principles and engineering

    Science.gov (United States)

    Qin, Shengping; Caskey, Charles F.; Ferrara, Katherine W.

    2009-03-01

    Microbubble contrast agents and the associated imaging systems have developed over the past 25 years, originating with manually-agitated fluids introduced for intra-coronary injection. Over this period, stabilizing shells and low diffusivity gas materials have been incorporated in microbubbles, extending stability in vitro and in vivo. Simultaneously, the interaction of these small gas bubbles with ultrasonic waves has been extensively studied, resulting in models for oscillation and increasingly sophisticated imaging strategies. Early studies recognized that echoes from microbubbles contained frequencies that are multiples of the microbubble resonance frequency. Although individual microbubble contrast agents cannot be resolved—given that their diameter is on the order of microns—nonlinear echoes from these agents are used to map regions of perfused tissue and to estimate the local microvascular flow rate. Such strategies overcome a fundamental limitation of previous ultrasound blood flow strategies; the previous Doppler-based strategies are insensitive to capillary flow. Further, the insonation of resonant bubbles results in interesting physical phenomena that have been widely studied for use in drug and gene delivery. Ultrasound pressure can enhance gas diffusion, rapidly fragment the agent into a set of smaller bubbles or displace the microbubble to a blood vessel wall. Insonation of a microbubble can also produce liquid jets and local shear stress that alter biological membranes and facilitate transport. In this review, we focus on the physical aspects of these agents, exploring microbubble imaging modes, models for microbubble oscillation and the interaction of the microbubble with the endothelium.

  16. Liquid scintillation techniques-physical principles, instrumentation, methodology and practical applications

    International Nuclear Information System (INIS)

    Mesquita, C.H. de.

    1980-01-01

    The measurement of low energy β emitting radioisotopes, in particular 3 H and 14 C, became the final step of almost all the analytical procedures envolving organic compounds or biological specimens which cannot be easily labeled using other radionuclides. The very low efficiency or even the absolute impossibility of measuring their radioactivity by the conventional methods (solid scintillators, gas counters, etc.) led to the development of liquid scintillation techniques. The possibility of obtaining counting geometries up to 4π for a certain radioactive source, has increased enourmously the performance of this type of counters that use scintillating solutions, providing total efficiencies of about 50% for 3 H and 14 C. The theoretical basis for the use of these solutions and of the whole electronic systems, the physical and chemical characteristics of the scintillators and solvent which are normally utilized, the criteria for chosing them and finally the cautions recommended in preparing the samples for counting are all presented in these notes. (Author) [pt

  17. The Development of Enterprise Systems based on Cyber- Physical Systems Principles

    Directory of Open Access Journals (Sweden)

    Ioan Ştefan Sacală

    2014-12-01

    Full Text Available Research in the area of Cyber-Physical Systems (CPS and Internet of Things (IoT become, in the last 3 years a priority for both research entities and companies. Implementing Enterprise Systems based on the two paradigms is focused on merging real and virtual objects and thus deals with an increased degree of complexity. The aim of the present paper is to discuss an Enterprise Architecture and a Framework based on the integration of CPS and IoT technologies within Enterprise Systems. An important aspect is related to process mining implemented in two focus areas: the ability to generate business processes from data acquired from sensors and the ability to integrate sensor acquired data with existing business processes.

  18. The complex itinerary of Leibniz’s planetary theory physical convictions, metaphysical principles and Keplerian inspiration

    CERN Document Server

    Bussotti, Paolo

    2015-01-01

    This book presents new insights into Leibniz’s research on planetary theory and his system of pre-established harmony. Although some aspects of this theory have been explored in the literature, others are less well known. In particular, the book offers new contributions on the connection between the planetary theory and the theory of gravitation. It also provides an in-depth discussion of Kepler’s influence on Leibniz’s planetary theory and, more generally, on Leibniz’s concept of pre-established harmony. Three initial chapters presenting the mathematical and physical details of Leibniz’s works provide a frame of reference. The book then goes on to discuss research on Leibniz’s conception of gravity and the connection between Leibniz and Kepler. .

  19. In vitro thermal profile suitability assessment of acids and bases for thermochemical ablation: underlying principles.

    Science.gov (United States)

    Freeman, Laura A; Anwer, Bilal; Brady, Ryan P; Smith, Benjamin C; Edelman, Theresa L; Misselt, Andrew J; Cressman, Erik N K

    2010-03-01

    To measure and compare temperature changes in a recently developed gel phantom for thermochemical ablation as a function of reagent strength and concentration with several acids and bases. Aliquots (0.5-1 mL) of hydrochloric acid or acetic acid and sodium hydroxide or aqueous ammonia were injected for 5 seconds into a hydrophobic gel phantom. Stepwise increments in concentration were used to survey the temperature changes caused by these reactions. Injections were performed in triplicate, measured with a thermocouple probe, and plotted as functions of concentration and time. Maximum temperatures were reached almost immediately in all cases, reaching 75 degrees C-110 degrees C at the higher concentrations. The highest temperatures were seen with hydrochloric acid and either base. More concentrated solutions of sodium hydroxide tended to mix incompletely, such that experiments at 9 M and higher were difficult to perform consistently. Higher concentrations for any reagent resulted in higher temperatures. Stronger acid and base combinations resulted in higher temperatures versus weak acid and base combinations at the same concentration. Maximum temperatures obtained are in a range known to cause tissue coagulation, and all combinations tested therefore appeared suitable for further investigation in thermochemical ablation. Because of the loss of the reaction chamber shape at higher concentrations of stronger agents, the phantom does not allow complete characterization under these circumstances. Adequate mixing of reagents to maximize heating potential and avoid systemic exposure to unreacted acid and base must be addressed if the method is to be safely employed in tissues. In addition, understanding factors that control lesion shape in a more realistic tissue model will be critical. Copyright 2010 SIR. Published by Elsevier Inc. All rights reserved.

  20. Physics of Lightning under Control of Big Scale Experiments

    Czech Academy of Sciences Publication Activity Database

    Mrázek, Josef

    2007-01-01

    Roč. 52, č. 2 (2007), s. 173-186 ISSN 0001-7043 Institutional research plan: CEZ:AV0Z20570509 Keywords : gas discharges * physics of lightning * long air gaps Subject RIV: BL - Plasma and Gas Discharge Physics

  1. The Obstacle Version of the Geometric Dynamic Programming Principle: Application to the Pricing of American Options Under Constraints

    International Nuclear Information System (INIS)

    Bouchard, Bruno; Vu, Thanh Nam

    2010-01-01

    We provide an obstacle version of the Geometric Dynamic Programming Principle of Soner and Touzi (J. Eur. Math. Soc. 4:201-236, 2002) for stochastic target problems. This opens the doors to a wide range of applications, particularly in risk control in finance and insurance, in which a controlled stochastic process has to be maintained in a given set on a time interval [0,T]. As an example of application, we show how it can be used to provide a viscosity characterization of the super-hedging cost of American options under portfolio constraints, without appealing to the standard dual formulation from mathematical finance. In particular, we allow for a degenerate volatility, a case which does not seem to have been studied so far in this context.

  2. Physical principles of intracellular organization via active and passive phase transitions

    Science.gov (United States)

    Berry, Joel; Brangwynne, Clifford P.; Haataja, Mikko

    2018-04-01

    Exciting recent developments suggest that phase transitions represent an important and ubiquitous mechanism underlying intracellular organization. We describe key experimental findings in this area of study, as well as the application of classical theoretical approaches for quantitatively understanding these data. We also discuss the way in which equilibrium thermodynamic driving forces may interface with the fundamentally out-of-equilibrium nature of living cells. In particular, time and/or space-dependent concentration profiles may modulate the phase behavior of biomolecules in living cells. We suggest future directions for both theoretical and experimental work that will shed light on the way in which biological activity modulates the assembly, properties, and function of viscoelastic states of living matter.

  3. Propulsion Physics Under the Changing Density Field Model

    Science.gov (United States)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will requires new propulsion physics. Specifically a propulsion physics model that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. In 2004 Khoury and Weltman produced a density dependent cosmology theory they called Chameleon Cosmology, as at its nature, it is hidden within known physics. This theory represents a scalar field within and about an object, even in the vacuum. Whereby, these scalar fields can be viewed as vacuum energy fields with definable densities that permeate all matter; having implications to dark matter/energy with universe acceleration properties; implying a new force mechanism for propulsion physics. Using Chameleon Cosmology, the author has developed a new propulsion physics model, called the Changing Density Field (CDF) Model. This model relates to density changes in these density fields, where the density field density changes are related to the acceleration of matter within an object. These density changes in turn change how an object couples to the surrounding density fields. Whereby, thrust is achieved by causing a differential in the coupling to these density fields about an object. Since the model indicates that the density of the density field in an object can be changed by internal mass acceleration, even without exhausting mass, the CDF model implies a new propellant-less propulsion physics model

  4. Essential Concepts and Underlying Theories from Physics, Chemistry, and Mathematics for "Biochemistry and Molecular Biology" Majors

    Science.gov (United States)

    Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A.; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry,…

  5. Physical quality of an oxisol under different uses

    Directory of Open Access Journals (Sweden)

    Francisco Ocian Bastos Mota

    2012-12-01

    Full Text Available The use of a soil induces changes in the physical properties according to the management, tillage intensity and type of crop. The objective of this work was to measure the alterations of some of the soil physical properties and evaluate the physical quality by the S index, an indicator proposed by Dexter (2004, comparing the land uses: eucalyptus plantations at different ages, grazing pasture, annual crops, and an area of preserved secondary vegetation with an area of preserved native forest (National Forest Araripe - NFA as control. The study was carried out on an Oxisol on the Fazenda Redenção, in Jardim, State of Ceará, Brazil. The experiment was arranged in a completely randomized design with seven treatments and three replications in the layers 0-0.1 and 0.1-0.2 m. The soil was analyzed for the following physical properties: bulk density, particle density, total pore volume, micro and macroporosity, soil water retention curves and water availability. Based on the S index, the hypothesis that the use of a soil deteriorates the physical quality was accepted. Clearly, native forest (NFA was the land use with the best conditions in all physical properties studied, followed closely by the area reforested with 20 year-old eucalyptus. The use as grazing pasture affected the soil physical conditions most, especially in the surface layer (0-0.1 m, as evidenced by increased bulk density and a substantial reduction in soil porosity, mainly in macroporosity. Microporosity was not influenced by any of the uses and in any layer studied.

  6. Some Physical Principles Governing Spatial and Temporal Organization in Living Systems

    Science.gov (United States)

    Ali, Md Zulfikar

    . Our studies demonstrate both the importance of employing a sequence-based evolutionary scheme and the relative rapidity (in evolutionary time) for the redistribution of function over new nodes via neutral drift. In addition we discovered another much slower timescale for network evolution, reflecting hidden order in sequence space that we interpret in terms of sparsely connected domains. Finally, we use the model to study the evolution of an oscillator from a non-oscillatory network under the influence of external periodic forcing as a model for evolution of circadian rhythm in living systems. We use a greedy algorithm based on optimizing biologically motivated fitness functions and find that the algorithm successfully produces oscillators. However, the distribution of free-period of evolved oscillators depends on the choice of fitness functions and the nature of forcing.

  7. Developing "Personality" Taxonomies: Metatheoretical and Methodological Rationales Underlying Selection Approaches, Methods of Data Generation and Reduction Principles.

    Science.gov (United States)

    Uher, Jana

    2015-12-01

    Taxonomic "personality" models are widely used in research and applied fields. This article applies the Transdisciplinary Philosophy-of-Science Paradigm for Research on Individuals (TPS-Paradigm) to scrutinise the three methodological steps that are required for developing comprehensive "personality" taxonomies: 1) the approaches used to select the phenomena and events to be studied, 2) the methods used to generate data about the selected phenomena and events and 3) the reduction principles used to extract the "most important" individual-specific variations for constructing "personality" taxonomies. Analyses of some currently popular taxonomies reveal frequent mismatches between the researchers' explicit and implicit metatheories about "personality" and the abilities of previous methodologies to capture the particular kinds of phenomena toward which they are targeted. Serious deficiencies that preclude scientific quantifications are identified in standardised questionnaires, psychology's established standard method of investigation. These mismatches and deficiencies derive from the lack of an explicit formulation and critical reflection on the philosophical and metatheoretical assumptions being made by scientists and from the established practice of radically matching the methodological tools to researchers' preconceived ideas and to pre-existing statistical theories rather than to the particular phenomena and individuals under study. These findings raise serious doubts about the ability of previous taxonomies to appropriately and comprehensively reflect the phenomena towards which they are targeted and the structures of individual-specificity occurring in them. The article elaborates and illustrates with empirical examples methodological principles that allow researchers to appropriately meet the metatheoretical requirements and that are suitable for comprehensively exploring individuals' "personality".

  8. nonlinMIP contribution to CMIP6: model intercomparison project for non-linear mechanisms: physical basis, experimental design and analysis principles (v1.0

    Directory of Open Access Journals (Sweden)

    P. Good

    2016-11-01

    Full Text Available nonlinMIP provides experiments that account for state-dependent regional and global climate responses. The experiments have two main applications: (1 to focus understanding of responses to CO2 forcing on states relevant to specific policy or scientific questions (e.g. change under low-forcing scenarios, the benefits of mitigation, or from past cold climates to the present day, or (2 to understand the state dependence (non-linearity of climate change – i.e. why doubling the forcing may not double the response. State dependence (non-linearity of responses can be large at regional scales, with important implications for understanding mechanisms and for general circulation model (GCM emulation techniques (e.g. energy balance models and pattern-scaling methods. However, these processes are hard to explore using traditional experiments, which explains why they have had so little attention in previous studies. Some single model studies have established novel analysis principles and some physical mechanisms. There is now a need to explore robustness and uncertainty in such mechanisms across a range of models (point 2 above, and, more broadly, to focus work on understanding the response to CO2 on climate states relevant to specific policy/science questions (point 1. nonlinMIP addresses this using a simple, small set of CO2-forced experiments that are able to separate linear and non-linear mechanisms cleanly, with a good signal-to-noise ratio – while being demonstrably traceable to realistic transient scenarios. The design builds on the CMIP5 (Coupled Model Intercomparison Project Phase 5 and CMIP6 DECK (Diagnostic, Evaluation and Characterization of Klima protocols, and is centred around a suite of instantaneous atmospheric CO2 change experiments, with a ramp-up–ramp-down experiment to test traceability to gradual forcing scenarios. In all cases the models are intended to be used with CO2 concentrations rather than CO2 emissions as the input. The

  9. Soil physical and hydraulic properties modification under Arachis ...

    African Journals Online (AJOL)

    Reductions in soil water evaporation were 44.5%, 41.1% and 34.7% under SAMNUT 21, PINTOI and SAMNUT 10 respectively. Significant (p= 0.05) improvement on soil structure and hydraulic conductivity was observed under Arachis varieties. Plant density of 66667 plants/ha showed the best positive effect on the ...

  10. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  11. Light-Emitting Diodes: Exploration of Underlying Physics

    Science.gov (United States)

    Etkina, Eugenia; Planinšic, Gorazd

    2014-01-01

    This paper is the second in the series of LED-dedicated papers that have a goal to systematically investigate the use of LEDs in a general physics course. The first paper, published in the February 2014 issue, provided an overview of the course units where LEDs can be used and suggested three different ways of utilizing LEDs in an introductory…

  12. US physics begins to crumble under budget strain

    CERN Multimedia

    2008-01-01

    The reality of the US budget cuts to particle physics has hit home. The Stanford Linear Accelerator Center (SLAC) in California, US, has just announced a trio of painful consequences: the end of work on the International Linear Collider, the imminent closure of its BaBar antimatter experiment, and the layoff of 125 workers.

  13. Physical and Chemical Properties of Soils under Contrasting Land ...

    African Journals Online (AJOL)

    The soil chemical properties studied were soil pH, organic carbon, total nitrogen, available P, exchangeable base (Ca2+, Mg2+, K+ and Na+) and exchangeable acidity (H+ and Al3+). The physical properties were aggregate stability, mean weight diameter, water dispersible clay and clay flocculation index. Two fractions of ...

  14. Assessing participants' perceptions on group-based principles for action in community-based health enhancing physical activity programmes: The APEF tool.

    Science.gov (United States)

    Herens, Marion; Wagemakers, Annemarie

    2017-12-01

    In community-based health enhancing physical activity (CBHEPA) programmes, group-based principles for action such as active participation, enjoyment, and fostering group processes are widely advocated. However, not much is known about participants' perceptions of these principles as there are no assessment tools available. Therefore, this article describes the development of the APEF (Active Participation, Enjoyment, and Fostering group processes) tool and reports on its implementation in a Dutch CBHEPA programme. Indicators for the principles have been identified from literature research, interviews with professionals, and secondary analysis of three group interviews with 11 practitioners. To address the identified indicators, the APEF tool was developed, pretested, and used in 10 focus groups with 76 participants. The APEF tool consists of eight statements about group-based principles for action, on which CBHEPA participants vote, followed by in-depth discussion. The voting procedure engages participants. Spider diagrams visualise participants' perceptions of group-based principles. The APEF tool addresses the challenge of relating group level outcomes to individual outcomes such as physical activity behaviour. The tool facilitates as well as evaluates group-based principles for action, it stimulates dialogue and is culturally sensitive, but it needs strong facilitating skills to manage group dynamics. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. [Physical principles of sclerostomy].

    Science.gov (United States)

    Fankhauser, F; Kwasniewska, S

    1993-03-01

    Various sclerostomy procedures, performed ab interno and ab externo have found increasing interest for some time. With few exceptions, invasive procedures are described, in which laser energy is transmitted by means of specially designed fibers and probes ab interno and ab externo to the perforation site. Laser energy sources, ranging from the UV through the visible to the IR range have been described. Thus far, no detailed models quantifying the ablation mechanism of such sclerostomy procedures have been published. All such procedures have in common that the wavelength of the laser should be matched to water absorption bands. Now more sophisticated models describing the action mechanism of various lasers begin to emerge. A system described by us takes advantage of the high efficiency of rapid steam explosions occurring in a closed space, i.e. in the region delimited by the probe end and the fistula bottom. The high efficiency of such mechanisms has been verified in model experiments on porcine eyes in vitro. Electron microscopical results also show that the amount of thermal damage is negligible and that there is very little wavelength-dependence. This permits the adoption of "common" laser energy sources such as diode and Nd:YAG lasers. The clinical survival probability of fistulas as related to the amount of collateral damage is controversial.

  16. X-ray imaging physics for nuclear medicine technologists. Part 1: Basic principles of x-ray production.

    Science.gov (United States)

    Seibert, J Anthony

    2004-09-01

    The purpose is to review in a 4-part series: (i) the basic principles of x-ray production, (ii) x-ray interactions and data capture/conversion, (iii) acquisition/creation of the CT image, and (iv) operational details of a modern multislice CT scanner integrated with a PET scanner. Advances in PET technology have lead to widespread applications in diagnostic imaging and oncologic staging of disease. Combined PET/CT scanners provide the high-resolution anatomic imaging capability of CT with the metabolic and physiologic information by PET, to offer a significant increase in information content useful for the diagnostician and radiation oncologist, neurosurgeon, or other physician needing both anatomic detail and knowledge of disease extent. Nuclear medicine technologists at the forefront of PET should therefore have a good understanding of x-ray imaging physics and basic CT scanner operation, as covered by this 4-part series. After reading the first article on x-ray production, the nuclear medicine technologist will be familiar with (a) the physical characteristics of x-rays relative to other electromagnetic radiations, including gamma-rays in terms of energy, wavelength, and frequency; (b) methods of x-ray production and the characteristics of the output x-ray spectrum; (c) components necessary to produce x-rays, including the x-ray tube/x-ray generator and the parameters that control x-ray quality (energy) and quantity; (d) x-ray production limitations caused by heating and the impact on image acquisition and clinical throughput; and (e) a glossary of terms to assist in the understanding of this information.

  17. Healthy Kids Out of School: Using Mixed Methods to Develop Principles for Promoting Healthy Eating and Physical Activity in Out-of-School Settings in the United States

    OpenAIRE

    Sliwa, Sarah A.; Sharma, Shanti; Dietz, William H.; Dolan, Peter R.; Nelson, Miriam E.; Newman, Molly B.; Rockeymoore, Maya; Economos, Christina D.

    2014-01-01

    Introduction Widespread practices supporting availability of healthful foods, beverages, and physical activity in out-of-school-time (OST) settings would further obesity prevention efforts. The objective of this article was to describe principles to guide policy development in support of healthy eating and physical activity practices in out-of-school settings to promote obesity prevention. Methods The Institute of Medicine?s L.E.A.D. framework (Locate Evidence, Evaluate it, Assemble it, and I...

  18. Mach's Principle

    Indian Academy of Sciences (India)

    popularize science. The underlying idea in Mach's principle is that the origin of inertia or mass of a particle is a dynamical quantity determined by the environ- ... Knowing the latitude of the location of the pendulum it is possible to calculate the Earth's spin period. The two methods give the same answer. At first sight this does ...

  19. Derivation of the blackbody radiation spectrum from the equivalence principle in classical physics with classical electromagnetic zero-point radiation

    International Nuclear Information System (INIS)

    Boyer, T.H.

    1984-01-01

    A derivation of Planck's spectrum including zero-point radiation is given within classical physics from recent results involving the thermal effects of acceleration through classical electromagnetic zero-point radiation. A harmonic electric-dipole oscillator undergoing a uniform acceleration a through classical electromagnetic zero-point radiation responds as would the same oscillator in an inertial frame when not in zero-point radiation but in a different spectrum of random classical radiation. Since the equivalence principle tells us that the oscillator supported in a gravitational field g = -a will respond in the same way, we see that in a gravitational field we can construct a perpetual-motion machine based on this different spectrum unless the different spectrum corresponds to that of thermal equilibrium at a finite temperature. Therefore, assuming the absence of perpetual-motion machines of the first kind in a gravitational field, we conclude that the response of an oscillator accelerating through classical zero-point radiation must be that of a thermal system. This then determines the blackbody radiation spectrum in an inertial frame which turns out to be exactly Planck's spectrum including zero-point radiation

  20. Elastic properties and electronic structure of WS{sub 2} under pressure from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics; Civil Aviation Flight Univ. of China, Guanghan (China). Dept. of Physics; Zeng, Zhao-Yi [Chongqing Normal Univ., Chongqing (China). College of Physics and Electronic Engineering; Liang, Ting; Tang, Mei; Cheng, Yan [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics

    2017-07-01

    The influence of pressure on the elastic and mechanical properties of the hexagonal transition-metal dichalcogenide WS{sub 2} is investigated using the first-principles calculations. With the increase in pressure, the lattice parameters and the volume of WS{sub 2} decrease, which is exactly in agreement with the available experimental data and other calculated results. The elastic constants C{sub ij}, bulk modulus B, shear modulus G, Young's modulus E, and Poisson's ratio σ of WS{sub 2} also increase with pressure. At last, for the first time, the band gaps of energy, the partial density of states, and the total density of states under three different pressures are obtained and analysed. It is found that the band gap of WS{sub 2} decreases from 0.843 to 0 eV when the external pressure varies from 0 to 20 GPa, which implies that WS{sub 2} may transform from semiconductors to semimetal phase at a pressure about 20 GPa.

  1. The duality in the topological vetor spaces and the theory of the linear physical systems. 2. Superposition principle in the L2(-infinito, +infinito)

    International Nuclear Information System (INIS)

    Oliveira Castro, F.M. de.

    1981-01-01

    Several properties of the linear functional that describes the relation between excitation and response of linear physical system, in the case where the excitation space is o L 2 (-infinite, +infinite), are studied. The superposition principle in such a space is pointed out. This study is applied to the dispersion relations. (L.C.) [pt

  2. The under-critical reactors physics for the hybrid systems

    International Nuclear Information System (INIS)

    Schapira, J.P.; Vergnes, J.; Zaetta, A.

    1998-01-01

    This day, organized by the SFEN, took place at Paris the 12 march 1998. Nine papers were presented. They take stock on the hybrid systems and more specifically the under-critical reactors. One of the major current preoccupation of nuclear industry is the problems of the increase of radioactive wastes produced in the plants and the destruction of the present stocks. To solve these problems a solution is the utilisation of hybrid systems: the coupling of a particle acceleration to an under-critical reactor. Historical aspects, advantages and performances of such hybrid reactors are presented in general papers. More technical papers are devoted to the spallation, the MUSE and the TARC experiments. (A.L.B.)

  3. Underlying Event Studies and Forward Physics at CMS

    International Nuclear Information System (INIS)

    Krammer, Manfred; Bartalini, Paolo

    2010-01-01

    Studies of the underlying event and forward processes are important tests of the standard model and inputs for Monte Carlo tuning. By selecting regions transverse and parallel to the hard parton-parton scatter, different aspects of non-perturbative QCD are enhanced and allow fine tuning of different Monte Carlo models. The underlying event in pp interactions, recorded by the CMS detector, is studied measuring the charged multiplicity density and the charged energy density in a region perpendicular to the plane of the hard 2-to-2 scattering. Two different methodologies are adopted to identify the direction and the energy scale of the hard scattering in Minimum Bias events that rely on the leading charged track and on the leading charged jet. The study allows to discriminate between various QCD Monte Carlo models with different multiple parton interaction schemes. In addition, we present the measurement of the underlying event using the jet area/ median approach. We demonstrate its sensitivity to different underlying event scenarios and tunes on generator level after applying detector specific cuts and thresholds. In the forward direction, the first measurement of forward energy flow in 3 35 GeV and compare to model with different multi-parton interaction schemes. In addition, the absence of energy deposition in the forward region is used to observe diffractive events. We compare our results with predictions from Monte Carlo event generators including a simulation of multi-parton scattering. All four measurements can be used to determine the parameters of multi-parton interaction models in a extended region of phase space. (author)

  4. Genetic and environmental transactions underlying the association between physical fitness/physical exercise and body composition

    DEFF Research Database (Denmark)

    Johnson, Wendy; de Ruiter, Ingrid; Kyvik, Kirsten Ohm

    2015-01-01

    We examined mean effects and variance moderating effects of measures of physical activity and fitness on six measures of adiposity and their reciprocal effects in a subsample of the population-representative Danish Twin Registry. Consistent with prior studies, higher levels of physical activity...... these reciprocal effects are uniform. Some variance moderating effects also appeared due to biases in individual measures of adiposity, as well as to differences and inaccuracies in measures of physical activity. This suggests a need to avoid reliance on single measures of both physical activity and adiposity...... in attempting to understand the pathways involved in their linkages, and constraint in interpreting results if only single measures are available. Future research indications include identifying which physical activity-related environmental circumstances have relatively uniform effects on adiposity in everyone...

  5. Advancing solar energy forecasting through the underlying physics

    Science.gov (United States)

    Yang, H.; Ghonima, M. S.; Zhong, X.; Ozge, B.; Kurtz, B.; Wu, E.; Mejia, F. A.; Zamora, M.; Wang, G.; Clemesha, R.; Norris, J. R.; Heus, T.; Kleissl, J. P.

    2017-12-01

    As solar power comprises an increasingly large portion of the energy generation mix, the ability to accurately forecast solar photovoltaic generation becomes increasingly important. Due to the variability of solar power caused by cloud cover, knowledge of both the magnitude and timing of expected solar power production ahead of time facilitates the integration of solar power onto the electric grid by reducing electricity generation from traditional ancillary generators such as gas and oil power plants, as well as decreasing the ramping of all generators, reducing start and shutdown costs, and minimizing solar power curtailment, thereby providing annual economic value. The time scales involved in both the energy markets and solar variability range from intra-hour to several days ahead. This wide range of time horizons led to the development of a multitude of techniques, with each offering unique advantages in specific applications. For example, sky imagery provides site-specific forecasts on the minute-scale. Statistical techniques including machine learning algorithms are commonly used in the intra-day forecast horizon for regional applications, while numerical weather prediction models can provide mesoscale forecasts on both the intra-day and days-ahead time scale. This talk will provide an overview of the challenges unique to each technique and highlight the advances in their ongoing development which come alongside advances in the fundamental physics underneath.

  6. Phase transition, elastic and electronic properties of topological insulator Sb2Te3 under pressure: First principle study

    Science.gov (United States)

    Qing, Lu; Huai-Yong, Zhang; Yan, Cheng; Xiang-Rong, Chen; Guang-Fu, Ji

    2016-02-01

    The phase transition, elastic and electronic properties of three phases (phase I, II, and III) of Sb2Te3 are investigated by using the generalized gradient approximation (GGA) with the PBESOL exchange-correlation functional in the framework of density-functional theory. Some basic physical parameters, such as lattice constants, bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, acoustic velocity, and Debye temperature Θ are calculated. The obtained lattice parameters under various pressures are consistent with experimental data. Phase transition pressures are 9.4 GPa (I → II) and 14.1 GPa (II → III), which are in agreement with the experimental results. According to calculated elastic constants, we also discuss the ductile or brittle characters and elastic anisotropies of three phases. Phases I and III are brittle, while phase II is ductile. Of the three phases, phase II has the most serious degree of elastic anisotropy and phase III has the slightest one. Finally, we investigate the partial densities of states (PDOSs) of three phases and find that the three phases possess some covalent features. Project supported by the National Natural Science Foundation of China (Grant Nos. 11204192 and 11174214) and Jointly supported by the National Natural Science Foundation of China and the China Academy of Engineering Physics (NSAF) (Grant No. U1430117).

  7. Physical-chemical quality of onion analyzed under drying temperature

    Science.gov (United States)

    Djaeni, M.; Arifin, U. F.; Sasongko, S. B.

    2017-03-01

    Drying is one of conventional processes to enhance shelf life of onion. However, the active compounds such as vitamin and anthocyanin (represented in red color), degraded due to the introduction of heat during the process. The objective of this research was to evaluate thiamine content as well as color in onion drying under different temperature. As an indicator, the thiamine and color was observed every 30 minutes for 2 hours. Results showed that thiamine content and color were sensitvely influenced by the temperature change. For example, at 50°C for 2 hours drying process, the thiamine degradation was 55.37 %, whereas, at 60°C with same drying time, the degradation was 74.01%. The quality degradation also increased by prolonging drying time.

  8. Soil physical properties of high mountain fields under bauxite mining

    Directory of Open Access Journals (Sweden)

    Dalmo Arantes de Barros

    2013-10-01

    Full Text Available Mining contributes to the life quality of contemporary society, but can generate significant impacts, these being mitigated due to environmental controls adopted. This study aimed to characterize soil physical properties in high-altitude areas affected by bauxite mining, and to edaphic factors responses to restoration techniques used to recover mined areas in Poços de Caldas plateau, MG, Brazil. The experiment used 3 randomized block design involving within 2 treatments (before mining intervention and after environmental recovery, and 4 replicates (N=24. In each treatment, soil samples with deformed structures were determined: granulometry, water-dispersible clay content, flocculation index, particle density, stoniness level, water aggregate stability, and organic matter contend. Soil samples with preserved structures were used to determine soil density and the total volume of pores, macropores, and micropores. Homogenization of stoniness between soil layers as a result of soil mobilization was observed after the mined area recovery. Stoniness decreased in 0.10-0.20 m layer after recovery, but was similar in the 0-0.10 m layer in before and after samples. The recovery techniques restored organic matter levels to pre-mining levels. However, changes in soil, including an increase in soil flocculation degree and a decrease in water-dispersible clays, were still apparent post-recovery. Furthermore, mining operations caused structural changes to the superficial layer of soil, as demonstrated by an increase in soil density and a decrease in total porosity and macroporosity. Decreases in the water stability of aggregates were observed after mining operations.

  9. What makes a reach movement effortful? Physical effort discounting supports common minimization principles in decision making and motor control.

    Science.gov (United States)

    Morel, Pierre; Ulbrich, Philipp; Gail, Alexander

    2017-06-01

    When deciding between alternative options, a rational agent chooses on the basis of the desirability of each outcome, including associated costs. As different options typically result in different actions, the effort associated with each action is an essential cost parameter. How do humans discount physical effort when deciding between movements? We used an action-selection task to characterize how subjective effort depends on the parameters of arm transport movements and controlled for potential confounding factors such as delay discounting and performance. First, by repeatedly asking subjects to choose between 2 arm movements of different amplitudes or durations, performed against different levels of force, we identified parameter combinations that subjects experienced as identical in effort (isoeffort curves). Movements with a long duration were judged more effortful than short-duration movements against the same force, while movement amplitudes did not influence effort. Biomechanics of the movements also affected effort, as movements towards the body midline were preferred to movements away from it. Second, by introducing movement repetitions, we further determined that the cost function for choosing between effortful movements had a quadratic relationship with force, while choices were made on the basis of the logarithm of these costs. Our results show that effort-based action selection during reaching cannot easily be explained by metabolic costs. Instead, force-loaded reaches, a widely occurring natural behavior, imposed an effort cost for decision making similar to cost functions in motor control. Our results thereby support the idea that motor control and economic choice are governed by partly overlapping optimization principles.

  10. Radiation exposure and image quality in X-ray diagnostic radiology. Physical principles and clinical applications. 2. ed.

    International Nuclear Information System (INIS)

    Saebel, Manfred; Aichinger, Horst; Dierker, Joachim; Joite-Barfuss, Sigrid

    2012-01-01

    Diagnostic X-rays are the largest contributor to radiation exposure to the general population, and protecting the patient from radiation damage is a major aim of modern health policy. Once the decision has been taken to use ionising radiation for imaging in a particular patient, it is necessary to optimize the image acquisition process taking into account the diagnostic quality of the images and the radiation dose to the patient. Both image quality and radiation dose are affected by a number of parameters, knowledge of which permits scientifically based decision making. The authors of this second edition of Radiation Exposure and Image Quality in X-ray Diagnostic Radiology have spent many years studying the optimization of radiological imaging. In this book they present in detail the basic physical principles of diagnostic radiology and their application to clinical problems. Particular attention is devoted to evaluation of the dose to the patient, the influence of scattered radiation on image quality, the use of antiscatter grids, and optimization of image quality and dose. The final section is a supplement containing tables of data and graphical depictions of X-ray spectra, interaction coefficients, characteristics of X-ray beams, and other aspects relevant to patient dose calculations. In addition, a complementary CD-ROM contains a user-friendly Excel file database covering these aspects that can be used in the reader's own programs. Since the first edition, the text, figures, tables, and references have all been thoroughly updated, and more detailed attention is now paid to image quality and radiation exposure when using digital imaging and computed tomography. This book will be an invaluable aid to medical physicists when performing calculations relating to patient dose and image quality, and will also prove useful for diagnostic radiologists and engineers. (orig.)

  11. First-principles calculation of thermodynamic stability of acids and bases under pH environment: A microscopic pH theory

    Science.gov (United States)

    Kim, Yong-Hyun; Kim, Kwiseon; Zhang, S. B.

    2012-04-01

    Despite being one of the most important thermodynamic variables, pH has yet to be incorporated into first-principles thermodynamics to calculate stability of acidic and basic solutes in aqueous solutions. By treating the solutes as defects in homogeneous liquids, we formulate a first-principles approach to calculate their formation energies under proton chemical potential, or pH, based on explicit molecular dynamics. The method draws analogy to first-principle calculations of defect formation energies under electron chemical potential, or Fermi energy, in semiconductors. From this, we propose a simple pictorial representation of the general theory of acid-base chemistry. By performing first-principles molecular dynamics of liquid water models with solutes, we apply the formulation to calculate formation energies of various neutral and charged solutes such as H+, OH-, NH3, NH4+, HCOOH, and HCOO- in water. The deduced auto-dissociation constant of water and the difference in the pKa values of NH3 and HCOOH show good agreement with known experimental values. Our first-principles approach can be further extended and applied to other bio- and electro-chemical molecules such as amino acids and redox reaction couples that could exist in aqueous environments to understand their thermodynamic stability.

  12. The 26th International Physics Olympiad: On top down under!

    Science.gov (United States)

    1996-01-01

    As they opened the plane door on arrival at Canberra it was like stepping inside a freezer. I had escaped from the heatwave in Britain to experience winter in Australia. I have not found anyone who believes that there was really frost! The Australian welcome did its best to combat the cold, however, and Professor Rod Jury had soon introduced our guides and got us settled in on the campus of Canberra University. The British team of five students, selected through the British Physics Olympiad, were: Alan Bain of Birkenhead School, Chris Blake of King Edward VI School, Southampton, Richard Davies of Dulwich College, Tom Down of Embley Park School, Romsey and Chris Webb of Royal Grammar School, Worcester. The two Leaders of the party were Cyril Isenberg of the University of Kent and Guy Bagnall of Harrow School. Chris Robson of St Bee's School and myself from Stoke on Trent Sixth form College were interested Observers and Guy's wife, Jenny, completed the party. For the old hands there were many friendships stretching back years to renew, and with 51 countries this year many new ones to be made. Â Photo Figure 1. Photograph taken by C Robson of the British Physics Team immediately after the Awards Ceremony in Canberra in July 1995. From left to right: Chris Webb, Richard Davies, Tom Down, Alan Bain and Chris Blake. In addition to the confusion caused by the Sun being in the North and the Moon appearing to lie on its back, we had to get used to the flocks of chattering parrots browsing on the lawns and the kangaroos on campus! Everyone was presented with a boomerang and there were several sessions introducing the art of throwing them, even in the dark! The Opening Ceremony was colourful and a good mix of ceremony and fun with the Aboriginal entertainment and the Flame of Science to be lit. This was followed by my first examiners' meeting. Once the questions have been introduced no one is allowed to leave the group until ten hours later when the students are in bed! The

  13. Healthy kids out of school: using mixed methods to develop principles for promoting healthy eating and physical activity in out-of-school settings in the United States.

    Science.gov (United States)

    Sliwa, Sarah A; Sharma, Shanti; Dietz, William H; Dolan, Peter R; Nelson, Miriam E; Newman, Molly B; Rockeymoore, Maya; Economos, Christina D

    2014-12-31

    Widespread practices supporting availability of healthful foods, beverages, and physical activity in out-of-school-time (OST) settings would further obesity prevention efforts. The objective of this article was to describe principles to guide policy development in support of healthy eating and physical activity practices in out-of-school settings to promote obesity prevention. The Institute of Medicine's L.E.A.D. framework (Locate Evidence, Evaluate it, Assemble it, and Inform Decisions) was used to identify practices relevant to children's healthful eating in most OST settings: 1) locate and evaluate information from a national survey of children's perceptions of healthful-food access; published research, reports, policies and guidelines; and roundtables with OST organizations' administrators; 2) assemble information to prioritize actionable practices; and 3) inform programmatic direction. Three evidence-informed guiding principles for short-duration OST resulted: 1) drink right: choose water instead of sugar-sweetened beverages; 2) move more: boost movement and physical activity in all programs; and 3) snack smart: fuel up on fruits and vegetables. Healthy Kids Out of School was launched to support the dissemination and implementation of these guiding principles in short-duration OST settings, complementing efforts in other OST settings to shift norms around eating and physical activity.

  14. Free-electron lasers in the ultraviolet and X-ray regime physical principles, experimental results, technical realization

    CERN Document Server

    Schmüser, Peter; Rossbach, Jörg; Behrens, Christopher

    2014-01-01

    The main goal of the book is to provide a systematic and didactic approach to the physics and technology of free-electron lasers. Numerous figures are used for illustrating the underlying ideas and concepts, and links to other fields of physics are provided. After an introduction to undulator radiation and the low-gain FEL, the one-dimensional theory of the high-gain FEL is developed in a systematic way. Particular emphasis is put on explaining and justifying the various assumptions and approximations that are needed to obtain the differential and integral equations governing the FEL dynamics. Analytical and numerical solutions are presented and important FEL parameters are defined, such as gain length, FEL bandwidth and saturation power. One of the most important features of a high-gain FEL, the formation of microbunches, is studied at length. The increase of gain length due to beam energy spread, space charge forces, and three-dimensional effects such as betatron oscillations and optical diffraction is anal...

  15. Framework for the design and delivery of organized physical activity sessions for children and adolescents: rationale and description of the 'SAAFE' teaching principles.

    Science.gov (United States)

    Lubans, David R; Lonsdale, Chris; Cohen, Kristen; Eather, Narelle; Beauchamp, Mark R; Morgan, Philip J; Sylvester, Benjamin D; Smith, Jordan J

    2017-02-23

    The economic burden of inactivity is substantial, with conservative estimates suggesting the global cost to health care systems is more than US$50 billion. School-based programs, including physical education and school sport, have been recommended as important components of a multi-sector, multi-system approach to address physical inactivity. Additionally, community sporting clubs and after-school programs (ASPs) offer further opportunities for young people to be physically active outside of school. Despite demonstrating promise, current evidence suggests school-based physical activity programs, community sporting clubs and ASPs are not achieving their full potential. For example, physical activity levels in physical education (PE) and ASP sessions are typically much lower than recommended. For these sessions to have the strongest effects on young people's physical activity levels and their on-going physical literacy, they need to improve in quality and should be highly active and engaging. This paper presents the Supportive, Active, Autonomous, Fair, Enjoyable (SAAFE) principles, which represent an evidence-based framework designed to guide the planning, delivery and evaluation of organized physical activity sessions in school, community sport and ASPs. In this paper we provide a narrative and integrative review of the conceptual and empirical bases that underpin this framework and highlight implications for knowledge translation and application.

  16. Novel instrument for characterizing comprehensive physical properties under multi-mechanical loads and multi-physical field coupling conditions

    Science.gov (United States)

    Liu, Changyi; Zhao, Hongwei; Ma, Zhichao; Qiao, Yuansen; Hong, Kun; Ren, Zhuang; Zhang, Jianhai; Pei, Yongmao; Ren, Luquan

    2018-02-01

    Functional materials represented by ferromagnetics and ferroelectrics are widely used in advanced sensor and precision actuation due to their special characterization under coupling interactions of complex loads and external physical fields. However, the conventional devices for material characterization can only provide a limited type of loads and physical fields and cannot simulate the actual service conditions of materials. A multi-field coupling instrument for characterization has been designed and implemented to overcome this barrier and measure the comprehensive physical properties under complex service conditions. The testing forms include tension, compression, bending, torsion, and fatigue in mechanical loads, as well as different external physical fields, including electric, magnetic, and thermal fields. In order to offer a variety of information to reveal mechanical damage or deformation forms, a series of measurement methods at the microscale are integrated with the instrument including an indentation unit and in situ microimaging module. Finally, several coupling experiments which cover all the loading and measurement functions of the instrument have been implemented. The results illustrate the functions and characteristics of the instrument and then reveal the variety in mechanical and electromagnetic properties of the piezoelectric transducer ceramic, TbDyFe alloy, and carbon fiber reinforced polymer under coupling conditions.

  17. Performance Evaluation of Survivability Strategies for Elastic Optical Networks under Physical Layer Impairments

    Directory of Open Access Journals (Sweden)

    Jurandir Lacerda Jr

    2017-08-01

    Full Text Available This paper carried out a performance evaluation study that compares two survivability strategies (DPP and SM-RSA for elastic optical networks with and without physical layer impairments. The evaluated scenarios include three representative topologies for elastic optical network, NSFNET, EON and USA. It also analyzes the increase of blocking probability when the survivability strategies are evaluated under the realistic scenario that assumes physical layer impairments. For all studied topologies under physical layer impairments, the survivability strategies achieved blocking probability above 80%.

  18. Extremum principles for irreversible processes

    International Nuclear Information System (INIS)

    Hillert, M.; Agren, J.

    2006-01-01

    Hamilton's extremum principle is a powerful mathematical tool in classical mechanics. Onsager's extremum principle may play a similar role in irreversible thermodynamics and may also become a valuable tool. His principle may formally be regarded as a principle of maximum rate of entropy production but does not have a clear physical interpretation. Prigogine's principle of minimum rate of entropy production has a physical interpretation when it applies, but is not strictly valid except for a very special case

  19. Underlying Physics of Conductive Polymer Composites and Force Sensing Resistors (FSRs) under Static Loading Conditions.

    Science.gov (United States)

    Paredes-Madrid, Leonel; Palacio, Carlos A; Matute, Arnaldo; Parra Vargas, Carlos A

    2017-09-14

    Conductive polymer composites are manufactured by randomly dispersing conductive particles along an insulating polymer matrix. Several authors have attempted to model the piezoresistive response of conductive polymer composites. However, all the proposed models rely upon experimental measurements of the electrical resistance at rest state. Similarly, the models available in literature assume a voltage-independent resistance and a stress-independent area for tunneling conduction. With the aim of developing and validating a more comprehensive model, a test bench capable of exerting controlled forces has been developed. Commercially available sensors-which are manufactured from conductive polymer composites-have been tested at different voltages and stresses, and a model has been derived on the basis of equations for the quantum tunneling conduction through thin insulating film layers. The resistance contribution from the contact resistance has been included in the model together with the resistance contribution from the conductive particles. The proposed model embraces a voltage-dependent behavior for the composite resistance, and a stress-dependent behavior for the tunneling conduction area. The proposed model is capable of predicting sensor current based upon information from the sourcing voltage and the applied stress. This study uses a physical (non-phenomenological) approach for all the phenomena discussed here.

  20. Principles underlying the epizootiology of viral hemorrhagic septicemia in Pacific herring and other fishes throughout the North Pacific Ocean

    Science.gov (United States)

    Hershberger, Paul K.; Garver, Kyle A.; Winton, James R.

    2016-01-01

    Although viral hemorrhagic septicemia virus (VHSV) typically occurs at low prevalence and intensity in natural populations of Pacific herring (Clupea pallasii) and other marine fishes in the Northeast Pacific Ocean, epizootics of the resulting disease (VHS) periodically occur, often in association with observed fish kills. Here we identify a list of principles, based on a combination of field studies, controlled laboratory experiments, and previously unpublished observations, that govern the epizootiology of VHS in Pacific herring. A thorough understanding of these principles provides the basis for identifying risk factors that predispose certain marine fish populations to VHS epizootics, including the lack of population resistance, presence of chronic viral carriers in a population, copious viral shedding by infected individuals, cool water temperatures, limited water circulation patterns, and gregarious host behavioral patterns. Further, these principles are used to define the epizootiological stages of the disease in Pacific herring, including the susceptible (where susceptible individuals predominate a school or subpopulation), enzootic (where infection prevalence and intensity are often below the limits of reasonable laboratory detection), disease amplification (where infection prevalence and intensity increase rapidly), outbreak (often accompanied by host mortalities with high virus loads and active shedding), recovery (in which the mortality rate and virus load decline owing to an active host immune response), and refractory stages (characterized by little or no susceptibility and where viral clearance occurs in most VHS survivors). In addition to providing a foundation for quantitatively assessing the potential risks of future VHS epizootics in Pacific herring, these principles provide insights into the epizootiology of VHS in other fish communities where susceptible species exist.

  1. Can Evolutionary Principles Explain Patterns of Family Violence?

    Science.gov (United States)

    Archer, John

    2013-01-01

    The article's aim is to evaluate the application of the evolutionary principles of kin selection, reproductive value, and resource holding power to the understanding of family violence. The principles are described in relation to specific predictions and the mechanisms underlying these. Predictions are evaluated for physical violence perpetrated…

  2. Acute physical exercise under hypoxia improves sleep, mood and reaction time.

    Science.gov (United States)

    de Aquino-Lemos, Valdir; Santos, Ronaldo Vagner T; Antunes, Hanna Karen Moreira; Lira, Fabio S; Luz Bittar, Irene G; Caris, Aline V; Tufik, Sergio; de Mello, Marco Tulio

    2016-02-01

    This study aimed to assess the effect of two sessions of acute physical exercise at 50% VO2peak performed under hypoxia (equivalent to an altitude of 4500 m for 28 h) on sleep, mood and reaction time. Forty healthy men were randomized into 4 groups: Normoxia (NG) (n = 10); Hypoxia (HG) (n = 10); Exercise under Normoxia (ENG) (n = 10); and Exercise under Hypoxia (EHG) (n = 10). All mood and reaction time assessments were performed 40 min after awakening. Sleep was reassessed on the first day at 14 h after the initiation of hypoxia; mood and reaction time were measured 28 h later. Two sessions of acute physical exercise at 50% VO2peak were performed for 60 min on the first and second days after 3 and 27 h, respectively, after starting to hypoxia. Improved sleep efficiency, stage N3 and REM sleep and reduced wake after sleep onset were observed under hypoxia after acute physical exercise. Tension, anger, depressed mood, vigor and reaction time scores improved after exercise under hypoxia. We conclude that hypoxia impairs sleep, reaction time and mood. Acute physical exercise at 50% VO2peak under hypoxia improves sleep efficiency, reversing the aspects that had been adversely affected under hypoxia, possibly contributing to improved mood and reaction time.

  3. Engaging Stakeholders From Volunteer-Led Out-of-School Time Programs in the Dissemination of Guiding Principles for Healthy Snacking and Physical Activity.

    Science.gov (United States)

    Folta, Sara C; Koomas, Alyssa; Metayer, Nesly; Fullerton, Karen J; Hubbard, Kristie L; Anzman-Frasca, Stephanie; Hofer, Teresa; Nelson, Miriam; Newman, Molly; Sacheck, Jennifer; Economos, Christina

    2015-12-24

    Little effort has focused on the role of volunteer-led out-of-school time (OST) programs (ie, enrichment and sports programs) as key environments for the promotion of healthy eating and physical activity habits among school-aged children. The Healthy Kids Out of School (HKOS) initiative developed evidence-based, practical guiding principles for healthy snacks, beverages, and physical activity. The goal of this case study was to describe the methods used to engage regional partners to understand how successful implementation and dissemination of these principles could be accomplished. HKOS partnered with volunteer-led programs from 5 OST organizations in Maine, Massachusetts, and New Hampshire to create a regional "learning laboratory." We engaged partners in phases. In the first phase, we conducted focus groups with local volunteer program leaders; during the second phase, we held roundtable meetings with regional and state program administrators; and in the final phase, we conducted additional outreach to refine and finalize implementation strategies. Implementation strategies were developed based on themes and information that emerged. For enrichment programs, strategies included new patch and pin programs that were consistent with the organizations' infrastructure and usual practices. For sports programs, the main strategy was integration with online trainings for coaches. Through the engagement process, we learned that dissemination of the guiding principles in these large and complex OST organizations was best accomplished by using implementation strategies that were customized, integrated, and aligned with goals and usual practices. The lessons learned can benefit future efforts to prevent obesity in complex environments.

  4. Changes in physical fitness profilogramach women aged 60 - 75 years under training health

    Directory of Open Access Journals (Sweden)

    Kortas Jakub

    2011-10-01

    Full Text Available The growing awareness of the society with regards to the positive influence of physical activity, and the ageing of world population are two facts that promote the need to develop qualified personnel of instructors. Individual approach to each group of training attendants is the principle of effective health training at every level of sport activity. This individual approach should be reflected in both the selection of training program, and the perceived effect of the activity. In the present work, I present personal analysis of influence of general keep-fit training performed in a gym. 36 women were enrolled in the study, for whom profilograms were created, which reflected the results of five measurements of physical fitness.

  5. First-principles study on the phase transitions, crystal stabilities and thermodynamic properties of TiN under high pressure

    Science.gov (United States)

    Sun, Xinjun; Liu, Changdong; Guo, Yongliang; Sun, Deyan; Ke, Xuezhi

    2018-03-01

    The structural and thermodynamic properties of titanium nitride (TiN) have been investigated by merging first-principles calculations and particle-swarm algorithm. The three phases are identified for TiN, including the B1, the P63 / mmc, and the B2 phases. A new phase of anti-TiP structure with the space group P63 / mmc has been predicted. The calculated phase transition from the B1 to the P63 / mmc occurs at 270 GPa. The vibrational, elastic, and thermodynamic properties for the three phases have been calculated and discussed.

  6. The tunneling radiation of a black hole with a f( R) global monopole under generalized uncertainty principle

    Science.gov (United States)

    Chen, Lingshen; Cheng, Hongbo

    2018-03-01

    The Parikh-Kraus-Wilczeck tunneling radiation of black hole involving a f( R) global monopole is considered based on the generalized uncertainty principle. The influences from global monopole, f( R) gravity and the corrections to the uncertainty appear in the expression of black hole entropy difference. It is found that the global monopole and the revision of general relativity both hinder the black hole from emitting the photons. The two parts as corrections to the uncertainty make the entropy difference of this kind of black hole larger or smaller respectively.

  7. Physical investigation of square cylinder array dynamical response under single-phase cross-flow

    International Nuclear Information System (INIS)

    Longatte, E.; Baj, F.

    2014-01-01

    Fluid structure interaction and flow-induced vibration in square cylinder arrangement under single-phase incompressible laminar cross flow are investigated in the present paper. Dynamic instability governed by damping generation is studied without any consideration about mixing with turbulence effects. Conservative and non-conservative effects are pointed out and dynamical stability limit sensitivity to physical parameters is analyzed. Finally the influence of key physical parameters on fluid solid dynamics interaction is quantified. (authors)

  8. Globalization and Equitable Use of Natural Resources in the Contemporary World: A Diagnosis Under the Bias of The Principle of Intergenerational Equity

    Directory of Open Access Journals (Sweden)

    Luís Marcelo Mendes

    2016-10-01

    Full Text Available Article  conduct  an  assessment  of  globalization  has  unleashed  the  commodification/depredation of natural resources in local/global scale to meet the interests of the market and the performance of the principle of intergenerational equity to try to curb this phenomenon. The research makes use of the deductive method, and uses dialectical contributions in order to implement a more accurate analysis of the phenomenon. At first, time will address under as globalization changes in consumption patterns of individuals in local/global level. Finally, it will take shape-the role of the principle of intergenerational equity by the legal system to try to curb ecological degradation.

  9. Quantum Physics for Scientists and Technologists Fundamental Principles and Applications for Biologists, Chemists, Computer Scientists, and Nanotechnologists

    CERN Document Server

    Sanghera, Paul

    2011-01-01

    Presenting quantum physics for the non-physicists, Quantum Physics for Scientists and Technologists is a self-contained, cohesive, concise, yet comprehensive, story of quantum physics from the fields of science and technology, including computer science, biology, chemistry, and nanotechnology. The authors explain the concepts and phenomena in a practical fashion with only a minimum amount of math. Examples from, and references to, computer science, biology, chemistry, and nanotechnology throughout the book make the material accessible to biologists, chemists, computer scientists, and non-techn

  10. Principles of object-oriented modeling and simulation with Modelica 3.3 a cyber-physical approach

    CERN Document Server

    Fritzson, Peter

    2014-01-01

    Fritzson covers the Modelica language in impressive depth from the basic concepts such as cyber-physical, equation-base, object-oriented, system, model, and simulation, while also incorporating over a hundred exercises and their solutions for a tutorial, easy-to-read experience. The only book with complete Modelica 3.3 coverage Over one hundred exercises and solutions Examines basic concepts such as cyber-physical, equation-based, object-oriented, system, model, and simulation

  11. Controlled traffic and soil physical quality of an Oxisol under sugarcane cultivation

    Directory of Open Access Journals (Sweden)

    Gustavo Soares de Souza

    2015-06-01

    Full Text Available Machinery traffic in sugarcane (Saccharumsp. plantations reduces soil physical quality, and hinders both root development and crop yield. We evaluated the physical quality of an Oxisol and the development of sugarcane roots under controlled traffic. The treatments assessed were: without controlled machinery traffic (WCT, controlled traffic by adjusting the tractor and infield wagons to a 3.0 m track width with the operator guiding the machinery (CT1 and the previous treatment using real time kinematic / global positioning system (RTK / GPS precision auto steer (CT2. Soil samples were collected from the planting rows, seedbed and inter-row center to determine the least limiting water range (LLWR and soil porosity from scanned 2-D images. The root dry mass was sampled from monoliths, separated from the soil by washing through a 2-mm sieve and dried in an oven. A higher LLWR was observed in the planting row under CT1 and CT2 than under WCT. The planting row had a predominance of complex pores with a diameter > 500 µm in the 0.15-0.27 m depth layer under CT1 and CT2. In the planting rows under WCT, the root dry mass was only 44 % of that measured under CT2. Benefits regarding soil physical quality and growth roots were observed when the tractor-wagon track width was adjusted based on the sugarcane spacing using either precision auto steering or manual operation of the machinery.

  12. Minimum entropy production principle

    Czech Academy of Sciences Publication Activity Database

    Maes, C.; Netočný, Karel

    2013-01-01

    Roč. 8, č. 7 (2013), s. 9664-9677 ISSN 1941-6016 Institutional support: RVO:68378271 Keywords : MINEP Subject RIV: BE - Theoretical Physics http://www.scholarpedia.org/article/Minimum_entropy_production_principle

  13. Evolution of the bonding mechanism of ZnO under isotropic compression: A first-principles study

    International Nuclear Information System (INIS)

    Zhou, G.C.; Sun, L.Z.; Wang, J.B.; Zhong, X.L.; Zhou, Y.C.

    2008-01-01

    The electronic structure and the bonding mechanism of ZnO under isotropic pressure have been studied by using the full-potential linear augmented plane wave (FP-LAPW) method within the density-functional theory (DFT) based on LDA+U exchange correlation (EXC) potential. We used the theory of Atoms in Molecules (AIM) method to analyze the change of the charge transfer and the bonding strength under isotropic pressure. The results of the theoretical analysis show that charge transfer between Zn and O atomic basins nearly linearly increases with the increasing pressure. Charge density along the Zn-O bond increases under the high pressure. The bonding strength and the ionicity of Zn-O bond also increase with the increasing pressure. The linear evolution process of the bonding mechanism under isotropic pressure was shown clearly in the present paper

  14. Physical Modelling of Bucket Foundation Under Long-Term Cyclic Lateral Loading

    DEFF Research Database (Denmark)

    Foglia, Aligi; Ibsen, Lars Bo; Andersen, Lars Vabbersgaard

    2012-01-01

    functioning. In this article a 1g physical model of bucket foundation under horizontal and moment cyclic loading is described. A testing program including four tests was carried out. Every test was conducted for at least 30000 cycles, each with different loading features. The capability of the model...

  15. Physics Based Electrolytic Capacitor Degradation Models for Prognostic Studies under Thermal Overstress

    Science.gov (United States)

    Kulkarni, Chetan S.; Celaya, Jose R.; Goebel, Kai; Biswas, Gautam

    2012-01-01

    Electrolytic capacitors are used in several applications ranging from power supplies on safety critical avionics equipment to power drivers for electro-mechanical actuators. This makes them good candidates for prognostics and health management research. Prognostics provides a way to assess remaining useful life of components or systems based on their current state of health and their anticipated future use and operational conditions. Past experiences show that capacitors tend to degrade and fail faster under high electrical and thermal stress conditions that they are often subjected to during operations. In this work, we study the effects of accelerated aging due to thermal stress on different sets of capacitors under different conditions. Our focus is on deriving first principles degradation models for thermal stress conditions. Data collected from simultaneous experiments are used to validate the desired models. Our overall goal is to derive accurate models of capacitor degradation, and use them to predict performance changes in DC-DC converters.

  16. Physical properties evaluation of roselle extract-egg white mixture under various drying temperatures

    Science.gov (United States)

    Triyastuti, M. S.; Kumoro, A. C.; Djaeni, M.

    2017-03-01

    Roselle contains anthocyanin that is potential for food colorant. Occasionally, roselle extract is provided in dry powder prepared under high temperature. In this case, the anthocyanin color degrades due to the intervention of heat. The foammat drying with egg white is a potential method to speed up the drying process as well as minimize color degradation. This research aims to study the physical properties of roselle extract under foam mat drying. As indicators, the powder size and color intensity were observed. The result showed that at high temperatures, roselle powder under foam mat drying has the fine size with porous structure. However, at the higher the drying temperature the color retention decreased.

  17. QSAR prediction of estrogen activity for a large set of diverse chemicals under the guidance of OECD principles.

    Science.gov (United States)

    Liu, Huanxiang; Papa, Ester; Gramatica, Paola

    2006-11-01

    A large number of environmental chemicals, known as endocrine-disrupting chemicals, are suspected of disrupting endocrine functions by mimicking or antagonizing natural hormones, and such chemicals may pose a serious threat to the health of humans and wildlife. They are thought to act through a variety of mechanisms, mainly estrogen-receptor-mediated mechanisms of toxicity. However, it is practically impossible to perform thorough toxicological tests on all potential xenoestrogens, and thus, the quantitative structure--activity relationship (QSAR) provides a promising method for the estimation of a compound's estrogenic activity. Here, QSAR models of the estrogen receptor binding affinity of a large data set of heterogeneous chemicals have been built using theoretical molecular descriptors, giving full consideration to the new OECD principles in regulation for QSAR acceptability, during model construction and assessment. An unambiguous multiple linear regression (MLR) algorithm was used to build the models, and model predictive ability was validated by both internal and external validation. The applicability domain was checked by the leverage approach to verify prediction reliability. The results obtained using several validation paths indicate that the proposed QSAR model is robust and satisfactory, and can provide a feasible and practical tool for the rapid screening of the estrogen activity of organic compounds.

  18. Principles of developing a well-rounded program of physical rehabilitation for female students in the special medical group with consideration of physical activity impairment

    Directory of Open Access Journals (Sweden)

    Golod N. R.

    2015-04-01

    Full Text Available Purpose : to highlight the main provisions of a comprehensive physical rehabilitation program for students of special medical group based on violations of the motor capacity. Material : testing 24 students of special medical group and the same number of their healthy peers on standardized tests of physical qualities. To reflect the movement disorders applied functional movement screen. Results : a program of rehabilitation of the students included: lifestyle modification; morning hygienic gymnastics; kinesitherapy (using yoga fitness, functional training; aerobic exercise (swimming, Nordic Walking, jogging, aerobics wellness; massage. First presented a unified approach to working with students of special medical groups - selection based on load capacity motor disorders according to the results of tests of functional movement screen. The complexity of the impact of the program involves the impact on the physical, social and mental health components. Conclusions : the author's program of physical rehabilitation of students of special medical group is complex.

  19. Principles of developing a well-rounded program of physical rehabilitation for female students in the special medical group with consideration of physical activity impairment

    Directory of Open Access Journals (Sweden)

    N. R. Golod

    2015-05-01

    Full Text Available Purpose : to highlight the main provisions of a comprehensive physical rehabilitation program for students of special medical group based on violations of the motor capacity. Material : testing 24 students of special medical group and the same number of their healthy peers on standardized tests of physical qualities. To reflect the movement disorders applied functional movement screen. Results : a program of rehabilitation of the students included: lifestyle modification; morning hygienic gymnastics; kinesitherapy (using yoga fitness, functional training; aerobic exercise (swimming, Nordic Walking, jogging, aerobics wellness; massage. First presented a unified approach to working with students of special medical groups - selection based on load capacity motor disorders according to the results of tests of functional movement screen. The complexity of the impact of the program involves the impact on the physical, social and mental health components. Conclusions : the author's program of physical rehabilitation of students of special medical group is complex.

  20. Application of the Physical Disector Principle for Quantification of Dopaminergic Neuronal Loss in a Rat 6-Hydroxydopamine Nigral Lesion Model of Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Katrine Fabricius

    2017-12-01

    Full Text Available Stereological analysis is the optimal tool for quantitative assessment of brain morphological and cellular changes induced by neurotoxic lesions or treatment interventions. Stereological methods based on random sampling techniques yield unbiased estimates of particle counts within a defined volume, thereby providing a true quantitative estimate of the target cell population. Neurodegenerative diseases involve loss of specific neuron types, such as the midbrain tyrosine hydroxylase-positive dopamine neurons in Parkinson's disease and in animal models of nigrostriatal degeneration. Therefore, we applied an established automated physical disector principle in a fractionator design for efficient stereological quantitative analysis of tyrosine hydroxylase (TH-positive dopamine neurons in the substantia nigra pars compacta of hemiparkinsonian rats with unilateral 6-hydroxydopamine (6-OHDA lesions. We obtained reliable estimates of dopamine neuron numbers, and established the relationship between behavioral asymmetry and dopamine neuron loss on the lesioned side. In conclusion, the automated physical disector principle provided a useful and efficient tool for unbiased estimation of TH-positive neurons in rat midbrain, and should prove valuable for investigating neuroprotective strategies in 6-OHDA model of parkinsonism, while generalizing to other immunohistochemically-defined cell populations.

  1. Engaging Stakeholders From Volunteer-Led Out-of-School Time Programs in the Dissemination of Guiding Principles for Healthy Snacking and Physical Activity

    Science.gov (United States)

    Koomas, Alyssa; Metayer, Nesly; Fullerton, Karen J.; Hubbard, Kristie L.; Anzman-Frasca, Stephanie; Hofer, Teresa; Nelson, Miriam; Newman, Molly; Sacheck, Jennifer; Economos, Christina

    2015-01-01

    Background Little effort has focused on the role of volunteer-led out-of-school time (OST) programs (ie, enrichment and sports programs) as key environments for the promotion of healthy eating and physical activity habits among school-aged children. The Healthy Kids Out of School (HKOS) initiative developed evidence-based, practical guiding principles for healthy snacks, beverages, and physical activity. The goal of this case study was to describe the methods used to engage regional partners to understand how successful implementation and dissemination of these principles could be accomplished. Community Context HKOS partnered with volunteer-led programs from 5 OST organizations in Maine, Massachusetts, and New Hampshire to create a regional “learning laboratory.” Methods We engaged partners in phases. In the first phase, we conducted focus groups with local volunteer program leaders; during the second phase, we held roundtable meetings with regional and state program administrators; and in the final phase, we conducted additional outreach to refine and finalize implementation strategies. Outcomes Implementation strategies were developed based on themes and information that emerged. For enrichment programs, strategies included new patch and pin programs that were consistent with the organizations’ infrastructure and usual practices. For sports programs, the main strategy was integration with online trainings for coaches. Interpretation Through the engagement process, we learned that dissemination of the guiding principles in these large and complex OST organizations was best accomplished by using implementation strategies that were customized, integrated, and aligned with goals and usual practices. The lessons learned can benefit future efforts to prevent obesity in complex environments. PMID:26704443

  2. Ultraviolet and soft X-ray free-electron lasers introduction to physical principles, experimental results, technological challenges

    CERN Document Server

    Schmüser, Peter; Rossbach, Jörg; Fujimori, A; Kühn, J; Müller, T; Steiner, F; Trümper, J; Varma, C; Wölfle, P

    2008-01-01

    In the introduction accelerator-based light sources are considered and a comparison is made between free-electron lasers and conventional quantum lasers. The motion and radiation of relativistic electrons in undulator magnets is discussed. The principle of a low-gain free-electron laser is explained and the pendulum equations are introduced that characterize the electron dynamics in the field of a light wave. The differential equations of the high-gain FEL are derived from the Maxwell equations of electrodynamics. Analytical and numerical solutions of the FEL equations are presented and important FEL parameters are defined, such as gain length, FEL bandwidth and saturation power. A detailed numerical study of the all-important microbunching process is presented. The mechanism of Self Amplified Spontaneous Emission is described theoretically and illustrated with numerous experimental results. Three-dimensional effects such as betatron oscillations and optical diffraction are addressed and their impact on the F...

  3. Differences Between the Family-Centered "COPCA" Program and Traditional Infant Physical Therapy Based on Neurodevelopmental Treatment Principles

    NARCIS (Netherlands)

    Dirks, Tineke; Blauw-Hospers, Cornill H.; Hulshof, Lily J.; Hadders-Algra, Mijna

    Background. Evidence for effectiveness of pediatric physical therapy in infants at high risk for developmental motor disorders is limited. Therefore, "Coping With and Caring for Infants With Special Needs" (COPCA), a family-centered, early intervention program, was developed. The COPCA program is

  4. [Comparative analysis of the physical status of students living under different conditions of environmental pollution].

    Science.gov (United States)

    Musalimova, R S; Valiakhmetov, R M

    2010-01-01

    The physical status was comparatively studied in students living under different conditions of environmental pollution. The anthropometric and some physiometric (vital capacity) parameters were established to be lower in students from polluted areas than in those from relatively pure ones. The students from polluted areas were observed to have higher hemodynamic parameters (heart rate, stroke volume, cardiac output). The results of the study improve and supplement knowledge of the physical development of the students living in the areas with varying environmental pollution levels and reflect the morphofunctional status that is an indicator in the evaluation of the body's functional tension, which may suggest the suppressing action of environmental pollution on the students' body.

  5. Denaturation of collagen structures and their transformation under the physical and chemical effects

    Science.gov (United States)

    Ivankin, A.; Boldirev, V.; Fadeev, G.; Baburina, M.; Kulikovskii, A.; Vostrikova, N.

    2017-11-01

    The process of denaturation of collagen structures under the influence of physical and chemical factors play an important role in the manufacture of food technology and the production of drugs for medicine and cosmetology. The paper discussed the problem of the combined effects of heat treatment, mechanical dispersion and ultrasonic action on the structural changes of the animal collagen in the presence of weak protonated organic acids. Algorithm combined effects of physical and chemical factors as a result of the formation of the technological properties of products containing collagen has been shown.

  6. Renal excretion of water in men under hypokinesia and physical exercise with fluid and salt supplementation

    Science.gov (United States)

    Zorbas, Yan G.; Federenko, Youri F.; Togawa, Mitsui N.

    It has been suggested that under hypokinesia (reduced number of steps/day) and intensive physical exercise, the intensification of fluid excretion in men is apparently caused as a result of the inability of the body to retain optimum amounts of water. Thus, to evaluate this hypothesis, studies were performed with the use of fluid and sodium chloride (NaCl) supplements on 12 highly trained physically healthy male volunteers aged 19-24 years under 364 days of hypokinesis (HK) and a set of intensive physical exercises (PE). They were divided into two groups with 6 volunteers per group. The first group of subjects were submitted to HK and took daily fluid and salt supplements in very small doses and the second group of volunteers were subjected to intensive PE and fluid-salt supplements. For the simulation of the hypokinetic effect, both groups of subjects were kept under an average of 4000 steps/day. During the prehypokinetic period of 60 days and under the hypokinetic period of 364 days water consumed and eliminated in urine by the men, water content in blood, plasma volume, rate of glomerular filtration, renal blood flow, osmotic concentration of urine and blood were measured. Under HK, the rate of renal excretion of water increased considerably in both groups. The additional fluid and salt intake failed to normalize water balance adequately under HK and PE. It was concluded that negative water balance evidently resulted not from shortage of water in the diet but from the inability of the body to retain optimum amounts of fluid under HK and a set of intensive PEs.

  7. First-principles predictions of structural, mechanical and electronic properties of βTiNb under high pressure

    Science.gov (United States)

    Wang, Z. P.; Fang, Q. H.; Li, J.; Liu, B.

    2018-04-01

    Structural, mechanical and electronic properties of βTiNb alloy under high pressure have been investigated based on the density functional theory (DFT). The dependences of dimensionless volume ratio, elastic constants, bulk modulus, Young's modulus, shear modulus, ductile/brittle, anisotropy and Poisson's ratio on applied pressure are all calculated successfully. The results reveal that βTiNb alloy is mechanically stable under pressure below 23.45 GPa, and the pressure-induced phase transformation could occur beyond this critical value. Meanwhile, the applied pressure can effectively promote the mechanical properties of βTiNb alloy, including the resistances to volume change, elastic deformation and shear deformation, as well as the material ductility and metallicity. Furthermore, the calculated electronic structures testify that βTiNb alloy performs the metallicity and the higher pressure reduces the structural stability of unit cell.

  8. First-principles investigation of the physical properties of cubic and orthorhombic phase Na3UO4

    Science.gov (United States)

    Chen, Haichuan; Tian, Wenyan

    2017-11-01

    The anisotropic elastic properties, Vickers hardness, Debye temperature and the minimum thermal conductivity of c-Na3UO4 and o-Na3UO4 have been investigated by means of the first principles calculations. The lattice parameters are in good agreement with the available experimental data and the theoretical results. The elastic constants satisfy the mechanical stability criteria show that both of them are mechanically stable. The value of B / G and Cauchy pressure reveal that the c-Na3UO4 holds a ductile behavior while the o-Na3UO4 behaves a brittle manner. The elastic anisotropy of c-Na3UO4 is less weak than that of o-Na3UO4. The hardness shows that both of them can be classified as ;soft materials;. Finally, the Debye temperature is 452.6 K and 388.4 K, and the minimum thermal conductivities kmin is 0.883 W m-1 K-1 and 0.753 W m-1 K-1 of c-Na3UO4 and o-Na3UO4, respectively. Due to relatively lower thermal conductivity, and thereby they are suitable to be used as thermal insulating materials.

  9. In situ radiometric mapping as a proxy of sediment contamination : Assessment of the underlying geochemical and -physical principles

    NARCIS (Netherlands)

    van der Graaf, E. R.; Koomans, R. L.; Limburg, J.; de Vries, K.

    Correlations between sediment contaminants like heavy metals or organic micro-compounds and natural or anthropogenic radionuclides (K-40, (238)u, Th-232, (CS)-C-137) facilitates in situ mapping of the contaminated sediment using gamma-ray detectors. These maps can be male quickly and economically

  10. Prediction of physical properties of water under extremely supercritical conditions: A molecular dynamics study

    Science.gov (United States)

    Sakuma, Hiroshi; Ichiki, Masahiro; Kawamura, Katsuyuki; Fuji-ta, Kiyoshi

    2013-04-01

    The physical properties of water under a wide range of pressure and temperature conditions are important in fundamental physics, chemistry, and geoscience. Molecular simulations are useful for predicting and understanding the physical properties of water at phases extremely different from ambient conditions. In this study, we developed a new five-site flexible induced point charge model to predict the density, static dielectric constant, and transport properties of water in the extremely supercritical phase at high temperatures and pressures of up to 2000 K and 2000 MPa. The model satisfactorily reproduced the density, radial distribution function, static dielectric constant, reorientation time, and self-diffusion coefficients of water above the critical points. We also developed a database of the static dielectric constant, which is useful for discussing the electrical conductivity of aqueous fluids in the earth's crust and mantle.

  11. Study of blood flow inside the stenosis vessel under the effect of solenoid magnetic field using ferrohydrodynamics principles

    Science.gov (United States)

    Badfar, Homayoun; Motlagh, Saber Yekani; Sharifi, Abbas

    2017-10-01

    In this paper, biomagnetic blood flow in the stenosis vessel under the effect of the solenoid magnetic field is studied using the ferrohydrodynamics (FHD) model. The parabolic profile is considered at an inlet of the axisymmetric stenosis vessel. Blood is modeled as electrically non-conducting, Newtonian and homogeneous fluid. Finite volume and the SIMPLE (Semi-Implicit Method for Pressure Linked Equations) algorithm are utilized to discretize governing equations. The investigation is studied at different magnetic numbers ( MnF=164, 328, 1640 and 3280) and the number of the coil loops (three, five and nine loops). Results indicate an increase in heat transfer, wall shear stress and energy loss (pressure drop) with an increment in the magnetic number (ratio of Kelvin force to dynamic pressure force), arising from the FHD, and the number of solenoid loops. Furthermore, the flow pattern is affected by the magnetic field, and the temperature of blood can be decreased up to 1.48 {}°C under the effect of the solenoid magnetic field with nine loops and reference magnetic field ( B0) of 2 tesla.

  12. Binding mechanisms of DNA/RNA nucleobases adsorbed on graphene under charging: first-principles van der Waals study

    Science.gov (United States)

    Gürel, Hikmet Hakan; Salmankurt, Bahadır

    2017-06-01

    Graphene is a 2D material that has attracted much attention due to its outstanding properties. Because of its high surface area and unique chemical and physical properties, graphene is a good candidate for biological applications. For this reason, a deep understanding of the mechanism of interaction of graphene with biomolecules is required. In this study, theoretical investigation of van der Waals effects has been conducted using density functional theory. Here we show that the order of the binding energies of five nucleobases with graphene is G  >  A  >  T  >  C  >   U. This trend is in good agreement with most of the theoretical and experimental data. Also, the effects of charging on the electronic and structural properties of the graphene-nucleubase systems are studied for the first time. We show that the binding energy can be changed by adding or removing an electron from the system. The results presented in this work provide fundamental insights into the quantum interactions of DNA with carbon-based nanostructures and will be useful for developments in biotechnology and nanotechnology.

  13. Soil physical and microbiological attributes cultivated with the common bean under two management systems

    Directory of Open Access Journals (Sweden)

    Lorena Adriana De Gennaro

    Full Text Available Agricultural management systems can alter the physical and biological soil quality, interfering with crop development. The objective of this study was to evaluate the physical and microbiological attributes of a Red Latosol, and its relationship to the biometric parameters of the common bean (Phaseolus vulgaris, irrigated and grown under two management systems (conventional tillage and direct seeding, in Campinas in the state of São Paulo, Brazil. The experimental design was of randomised blocks, with a split-plot arrangement for the management system and soil depth, analysed during the 2006/7 and 2007/8 harvest seasons, with 4 replications. The soil physical and microbiological attributes were evaluated at depths of 0.00-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m. The following were determined for the crop: density, number of pods per plant, number of beans per pod, thousand seed weight, total weight of the shoots and harvest index. Direct seeding resulted in a lower soil physical quality at a depth of 0.00-0.05 m compared to conventional tillage, while the opposite occurred at a depth of 0.05-0.10 m. The direct seeding showed higher soil biological quality, mainly indicated by the microbial biomass nitrogen, basal respiration and metabolic quotient. The biometric parameters in the bean were higher under the direct seeding compared to conventional tillage.

  14. Cellular Gauge Symmetry and the Li Organization Principle: A Mathematical Addendum. Quantifying energetic dynamics in physical and biological systems through a simple geometric tool and geodetic curves.

    Science.gov (United States)

    Yurkin, Alexander; Tozzi, Arturo; Peters, James F; Marijuán, Pedro C

    2017-12-01

    The present Addendum complements the accompanying paper "Cellular Gauge Symmetry and the Li Organization Principle"; it illustrates a recently-developed geometrical physical model able to assess electronic movements and energetic paths in atomic shells. The model describes a multi-level system of circular, wavy and zigzag paths which can be projected onto a horizontal tape. This model ushers in a visual interpretation of the distribution of atomic electrons' energy levels and the corresponding quantum numbers through rather simple tools, such as compasses, rulers and straightforward calculations. Here we show how this geometrical model, with the due corrections, among them the use of geodetic curves, might be able to describe and quantify the structure and the temporal development of countless physical and biological systems, from Langevin equations for random paths, to symmetry breaks occurring ubiquitously in physical and biological phenomena, to the relationships among different frequencies of EEG electric spikes. Therefore, in our work we explore the possible association of binomial distribution and geodetic curves configuring a uniform approach for the research of natural phenomena, in biology, medicine or the neurosciences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. The Registration of Special Notarial Bonds under the Security by Means of Movable Property Act and the Publicity Principle: Lessons from Developments in Belgium

    Directory of Open Access Journals (Sweden)

    Lefa

    2018-01-01

    Full Text Available Many people do not own immovable property to offer as security but do have movable property which can be offered as security for the repayment of a debt. In today's world, where the costs of a motor car can exceed that of a house, the increasing value of movable things makes them popular and appropriate security objects. Under the common law pledge, delivery of the movable property from the pledgor (the debtor to the pledgee (the creditor has to take place in order for the pledgee to acquire a real security right in the property. Delivery of the property is aimed at ensuring compliance with the publicity principle. The principle of publicity entails that the existence of a real security must be known to the public. With the aim of promoting commerce, certain countries have taken the initiative in reforming their laws on pledge to allow the debtor to retain possession of the movable property that serves as security. Furthermore, technology has advanced to a level where national registration systems which can be accessed easily and at minimal cost can be established. The South African legislature enacted the Security by Means of Movable Property Act 57 of 1993 which makes provision for a pledge without possession. This Act deemed a duly registered notarial bond over specified movable property to have been delivered as if delivery had in fact taken place, thereby substituting the common law delivery requirement with registration in the Deeds Office. On 30 May 2013 the Belgian House of Representatives adopted a Belgian Pledge Act which allows for a non-possessory pledge on movable property subject to registration in a newly created public register called the Electronic Pledge Register. This article therefore examines the efficacy of the registration system of special notarial bonds in South African law and whether this form of registration complies with the publicity principle looking at the developments of a computerised registration system taking

  16. First principles and Debye model study of the thermodynamic, electronic and optical properties of MgO under high-temperature and pressure

    Science.gov (United States)

    Miao, Yurun; Li, Huayang; Wang, Hongjuan; He, Kaihua; Wang, Qingbo

    2018-02-01

    First principles and quasi-harmonic Debye model have been used to study the thermodynamic properties, enthalpies, electronic and optical properties of MgO up to the core-mantle boundary (CMB) condition (137 GPa and 3700 K). Thermodynamic properties calculation includes thermal expansion coefficient and capacity, which have been studied up to the CMB pressure (137 GPa) and temperature (3700 K) by the Debye model with generalized gradient approximation (GGA) and local-density approximation (LDA). First principles with hybrid functional method (PBE0) has been used to calculate the electronic and optical properties under pressure up to 137 GPa and 0 K. Our results show the Debye model with LDA and first principles with PBE0 can provide accurate thermodynamic properties, enthalpies, electronic and optical properties. Calculated enthalpies show that MgO keep NaCl (B1) structure up to 137 GPa. And MgO is a direct bandgap insulator with a 7.23 eV calculated bandgap. The bandgap increased with increasing pressure, which will induce a blue shift of optical properties. We also calculated the density of states (DOS) and discussed the relation between DOS and band, optical properties. Equations were used to fit the relations between pressure and bandgaps, absorption coefficient (α(ω)) of MgO. The equations can be used to evaluate pressure after careful calibration. Our calculations can not only be used to identify some geological processes, but also offer a reference to the applications of MgO in the future.

  17. First-Row Transition Metal Based Catalysts for the Oxygen Evolution Reaction under Alkaline Conditions: Basic Principles and Recent Advances.

    Science.gov (United States)

    Lu, Fei; Zhou, Min; Zhou, Yuxue; Zeng, Xianghua

    2017-12-01

    Owing to its abundance, high gravimetric energy density, and environmental friendliness, hydrogen is a promising renewable energy to replace fossil fuels. One of the most prominent routes toward hydrogen acquisition is water splitting, which is currently bottlenecked by the sluggish kinetics of oxygen evolution reaction (OER). Numerous of electrocatalysts have been developed in the past decades to accelerate the OER process. Up to now, the first-row transition metal based compounds are in pole position under alkaline conditions, which have become subjects of extensive studies. Recently, significant advances in providing compelling catalytic performance as well as exploring their catalytic mechanisms have been achieved in this area. In this review, we summarized the fundamentals and recent progresses in first-row transition metal based OER catalysts, with special emphasis on the pathways of promoting catalytic performance by concrete strategies. New insight into material design, particularly the role of experimental approaches in the electrocatalytic performance and reaction mechanisms of OER are expected to be provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Evolutionary Connectionism: Algorithmic Principles Underlying the Evolution of Biological Organisation in Evo-Devo, Evo-Eco and Evolutionary Transitions.

    Science.gov (United States)

    Watson, Richard A; Mills, Rob; Buckley, C L; Kouvaris, Kostas; Jackson, Adam; Powers, Simon T; Cox, Chris; Tudge, Simon; Davies, Adam; Kounios, Loizos; Power, Daniel

    2016-01-01

    The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term "evolutionary connectionism" to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary

  19. Forest fine-root production and nitrogen use under elevated CO2: Contrasting responses explained by a common principle

    Energy Technology Data Exchange (ETDEWEB)

    Franklin, Oscar [International Institute for Applied Systems Analysis; McMurtrie, Ross E [ORNL; Iversen, Colleen M [ORNL; Crous, Kristine [University of Michigan; Finzi, Adrien C [Boston University; Tissue, David Thomas [ORNL; Ellsworth, David [ORNL; Oren, Ram [ORNL; Norby, Richard J [ORNL

    2009-01-01

    Despite the importance of nitrogen (N) limitation of forest carbon (C) sequestration at rising atmospheric CO2 concentration, the mechanisms responsible are not well understood. To elucidate the interactive effects of elevated CO2 (eCO2) and soil N availability on forest productivity and C allocation, we hypothesized that 1) trees maximize fitness by allocating N and C to maximize their net growth, and 2) that N uptake is controlled by root exploration for N. We tested this model using data collected in FACE sites dominated by evergreen (Pinus taeda; Duke Forest) and deciduous (Liquidambar styraciflua; Oak Ridge National Laboratory ORNL) trees. The model explained 80-95% of variation in productivity and N-uptake data among eCO2, N fertilization and control treatments over six years. The model explains why fine-root production increased, and why N uptake increased despite reduced soil N availability under eCO2 at ORNL and Duke. In agreement with observations at other sites, soil N availability reduced below a critical level diminishes all eCO2 responses. At Duke, a negative feedback between reduced soil N availability and N uptake counteracted progressive reduction in soil N availability at eCO2. At ORNL, decreasing soil N availability was perpetuated as it generated no reduction in N uptake, due to strongly increased production of fast turnover fine-roots. This implies that species with fast root turnover could be more prone to progressive N limitation of carbon sequestration in woody biomass than species with slow root turnover, such as evergreens.

  20. Mineralization of human bone tissue under hypokinesia and physical exercise with calcium supplements

    Science.gov (United States)

    Zorbas, Yan G.; Verentsov, Grigori E.; Abratov, Nikolai I.

    It has been suggested that physical exercise and calcium supplements may be used to prevent demineralization of bone tissue under hypokinesia (diminished muscular activity). Thus, the aim of this study was to determine mineral content of bones of 12 physically healthy men aged 19-24 years under 90 days of hypokinesia and intensive physical exercise (PE) with calcium lactate (C) supplements. They were divided into experimental and control groups with 6 men in each. The experimental group of men were subjected to hypokinesia (HK) and intensive PE and took 650 mg C 6 times per day; the control group was placed under pure HK, i.e. without the use of any preventive measures. The mineral content of different bone tissues was measured with a densitometric X-ray method in milligrams of calcium per 1 mm 3 before and after exposure to HK. The level of bone density of the examined bone tissues decreased by 7-9% and 5-7% for the control and experimental groups of men, respectively. A statistical analysis revealed that the reduction of bone mineralization was significant with P physical exercise with calcium supplements. Experimental studies of hypokinetic physiology are generally based on the assumption that diminished muscular activity (progressive reduction of number of steps per day) is detrimental to animal and human organisms, since the entire animal kingdom had been formed in an environment of high motor activity which left its imprint on the evolution, structure, function and behaviour of animals and men. The impossibility of the body tissues to retain optimum amounts of fluid and electrolytes is the dominant hypokinetic effect.

  1. Algorithmic Principles of Mathematical Programming

    NARCIS (Netherlands)

    Faigle, Ulrich; Kern, Walter; Still, Georg

    2002-01-01

    Algorithmic Principles of Mathematical Programming investigates the mathematical structures and principles underlying the design of efficient algorithms for optimization problems. Recent advances in algorithmic theory have shown that the traditionally separate areas of discrete optimization, linear

  2. Foreword to 'Multiscale structural biology: biophysical principles and mechanisms underlying the action of bio-nanomachines', a special issue in Honour of Fumio Arisaka's 70th birthday.

    Science.gov (United States)

    Hall, Damien; Takagi, Junichi; Nakamura, Haruki

    2018-03-02

    This issue of Biophysical Reviews, titled 'Multiscale structural biology: biophysical principles and mechanisms underlying the action of bio-nanomachines', is a collection of articles dedicated in honour of Professor Fumio Arisaka's 70th birthday. Initially, working in the fields of haemocyanin and actin filament assembly, Fumio went on to publish important work on the elucidation of structural and functional aspects of T4 phage biology. As his career has transitioned levels of complexity from proteins (hemocyanin) to large protein complexes (actin) to even more massive bio-nanomachinery (phage), it is fitting that the subject of this special issue is similarly reflective of his multiscale approach to structural biology. This festschrift contains articles spanning biophysical structure and function from the bio-molecular through to the bio-nanomachine level.

  3. The impact of the document international work group in death, dying and bereavement: assumptions and principles underlying standards for terminal care.

    Science.gov (United States)

    Vachon, Mary L S

    This article reflects on the development and impact of the International Workgroup on Death, Dying and Bereavement's (IWG) pivotal document on The Assumptions and Principles Underlying Standards for Terminal Care. It was at the Ars Moriendi meetings in Columbia, Maryland that the author first met Bob and Bunny Kastenbaum. The meeting led to the development of IWG and the first task of this group was the development of the "Standards" document. The initial document reflected the pioneering work already being done by Kastenbaum and others on the committee and then was formative in the development of other documents such as the National Hospice Association Standards. Participants in the original workgroup were asked for their reflections on the significance of the document and the literature was surveyed to assess the impact of the "Standards" document on the field.

  4. Soil physical and hydrological properties under three biofuel crops in Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, Catherine [Ohio State University; Lal, Dr. Rattan [Ohio State University; Schmitz, Matthias [Rheinsche Friedrich/Wilhelms Universitaet Boon; Wullschleger, Stan D [ORNL

    2012-01-01

    While biofuel crops are widely studied and compared for their energy and carbon footprints, less is known about their effects on other soil properties, particularly hydrologic characteristics. Soils under three biofuel crops, corn (Zea mays), switchgrass (Panicum virgatum), and willow (Salix spp.), were analyzed seven years after establishment to assess the effects on soil bulk density ({rho}{sub b}), penetration resistance (PR), water-holding capacity, and infiltration characteristics. The PR was the highest under corn, along with the lowest associated water content, while PR was 50-60% lower under switchgrass. In accordance with PR data, surface (0-10 cm) bulk density also tended to be lower under switchgrass. Both water infiltration rates and cumulative infiltration amounts varied widely among and within the three crops. Because the Philip model did not fit the data, results were analyzed using the Kostiakov model instead. Switchgrass plots had an average cumulative infiltration of 69 cm over 3 hours with a constant infiltration rate of 0.28 cm min{sup -1}, compared with 37 cm and 0.11 cm min{sup -1} for corn, and 26 cm and 0.06 cm min{sup -1} for willow, respectively. Results suggest that significant changes in soil physical and hydrologic properties may require more time to develop. Soils under switchgrass may have lower surface bulk density, higher field water capacity, and a more rapid water infiltration rate than those under corn or willow.

  5. Physical properties of a rhodic haplustox under two sugarcane harvesting systems

    Directory of Open Access Journals (Sweden)

    Walquíria Machado

    2010-12-01

    Full Text Available This study had the purpose of evaluating the effects of two management types of sugarcane: harvesting of burnt cane (BCH and mechanized harvesting of unburnt green cane (MCH, on some soil physical properties of a dystrophic Rhodic Haplustox. The data were then compared with results for the same soil type under native forest. A completely randomized design was used, with three treatments and 20 replications. The following characteristics were determined: organic matter, aggregate stability, soil bulk density, and porosity at depths of 0-0.20 m and soil penetration resistance. After 15 years of cultivation, there were some alterations in the soil under cane burnt before harvesting, evidenced by a drop in the weighted average diameter of stable aggregates in water and increased soil bulk density. Significant changes were also detected in total porosity and pore distribution under both harvesting systems. Critical values for penetration resistance were observed in the area under mechanized sugar cane harvesting, with a value of 4.5 MPa in the 40-55 cm layer. This value is considered high and could indicate compaction and restriction of root growth. Soil properties under the green cane (unburned management system were closest to those of the soil under native forest.

  6. Soil physical and hydrological properties under three biofuel crops in Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, Catherine; Lal, Rattan [The Ohio State Univ., School of Environment and Natural Resources, Carbon Management and Sequestration Center, Columbus, OH (United States); Schmitz, Matthias [Rheinische Friedrich/Wilhelms-Universitaet Bonn, Steinmann Institut fuer Geologie, Mineralogie und Palaeontologie, Bonn (Germany); Wullschleger, S. [The Oakridge National Lab., Oakridge, TN (United States)

    2012-10-15

    While biofuel crops are widely studied and compared for their energy and carbon footprints, less is known about their effects on other soil properties, particularly hydrologic characteristics. Soils under three biofuel crops, corn (Zea mays), switchgrass (Panicum virgatum), and willow (Salix spp.), were analyzed seven years after establishment to assess the effects on soil bulk density ({rho}{sub b}), penetration resistance (PR), water-holding capacity, and infiltration characteristics. The PR was the highest under corn, along with the lowest associated water content, while PR was 50-60 % lower under switchgrass. In accordance with PR data, surface (0-10 cm) bulk density also tended to be lower under switchgrass. Both water infiltration rates and cumulative infiltration amounts varied widely among and within the three crops. Because the Philip model did not fit the data, results were analyzed using the Kostiakov model instead. Switchgrass plots had an average cumulative infiltration of 69 cm over 3 hours with a constant infiltration rate of 0.28 cm min{sup -1}, compared with 37 cm and 0.11 cm min{sup -1} for corn, and 26 cm and 0.06 cm min{sup -1} for willow, respectively. Results suggest that significant changes in soil physical and hydrologic properties may require more time to develop. Soils under switchgrass may have lower surface bulk density, higher field water capacity, and a more rapid water infiltration rate than those under corn or willow.

  7. Nonlinear optics principles and applications

    CERN Document Server

    Li, Chunfei

    2017-01-01

    This book reflects the latest advances in nonlinear optics. Besides the simple, strict mathematical deduction, it also discusses the experimental verification and possible future applications, such as the all-optical switches. It consistently uses the practical unit system throughout. It employs simple physical images, such as "light waves" and "photons" to systematically explain the main principles of nonlinear optical effects. It uses the first-order nonlinear wave equation in frequency domain under the condition of “slowly varying amplitude approximation" and the classical model of the interaction between the light and electric dipole. At the same time, it also uses the rate equations based on the energy-level transition of particle systems excited by photons and the energy and momentum conservation principles to explain the nonlinear optical phenomenon. The book is intended for researchers, engineers and graduate students in the field of the optics, optoelectronics, fiber communication, information tech...

  8. High-pressure and high-temperature physical properties of half-metallic full-Heusler alloy Mn{sub 2}RuSi by first-principles and quasi-harmonic Debye model

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ting [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Ma, Qin, E-mail: maqin_lut@yeah.net [State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); Sun, Xiao-Wei [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Liu, Zi-Jiang [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Department of Physics, Lanzhou City University, Lanzhou 730070 (China); Wei, Xiao-Ping [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Tian, Jun-Hong [School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070 (China); Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China)

    2017-02-15

    First-principles calculations based on density functional theory and quasi-harmonic Debye model are used to investigate the high-pressure and high-temperature physical properties, including the lattice constant, magnetic moment, density of states, pressure-volume-temperature relationship, bulk modulus, thermal expansivity, heat capacity, and Grüneisen parameter for the new Mn-based full-Heusler alloy Mn{sub 2}RuSi in CuHg{sub 2}Ti-type structure. The optimized equilibrium lattice constant is consistent with experimental and other theoretical results. The calculated total spin magnetic moment remains an integral value of 2.0 μ{sub B} in the lattice constant range of 5.454–5.758 Å, and then decreases very slowly with the decrease of lattice constant to 5.333 Å. By the spin resolved density of states calculations, we have shown that Mn{sub 2}RuSi compound presents half-metallic ferrimagnetic properties under the equilibrium lattice constant. The effects of temperature and pressure on bulk modulus, thermal expansivity, heat capacity, and Grüneisen parameter are opposite, which are consistent with a compression rate of volume. Furthermore, the results show that the effect of temperature is larger than pressure for heat capacity and the effect of high temperature and pressure on thermal expansion coefficient is small. All the properties of Mn{sub 2}RuSi alloy are summarized in the pressure range of 0–100 GPa and the temperature up to 1200 K. - Highlights: • High-pressure and high-temperature physical properties of Mn2RuSi were investigated. • Ferrimagnetic ground state has been confirmed in Mn2RuSi alloy. • The first-principle calculations and quasi-harmonic Debye model were used. • The pressure up to 100 GPa and the temperature up to 1200 K.

  9. Device physics underlying silicon heterojunction and passivating-contact solar cells: A topical review

    KAUST Repository

    Chavali, Raghu V. K.

    2018-01-15

    The device physics of commercially dominant diffused-junction silicon solar cells is well understood, allowing sophisticated optimization of this class of devices. Recently, so-called passivating-contact solar cell technologies have become prominent, with Kaneka setting the world\\'s silicon solar cell efficiency record of 26.63% using silicon heterojunction contacts in an interdigitated configuration. Although passivating-contact solar cells are remarkably efficient, their underlying device physics is not yet completely understood, not in the least because they are constructed from diverse materials that may introduce electronic barriers in the current flow. To bridge this gap in understanding, we explore the device physics of passivating contact silicon heterojunction (SHJ) solar cells. Here, we identify the key properties of heterojunctions that affect cell efficiency, analyze the dependence of key heterojunction properties on carrier transport under light and dark conditions, provide a self-consistent multiprobe approach to extract heterojunction parameters using several characterization techniques (including dark J-V, light J-V, C-V, admittance spectroscopy, and Suns-Voc), propose design guidelines to address bottlenecks in energy production in SHJ cells, and develop a process-to-module modeling framework to establish the module\\'s performance limits. We expect that our proposed guidelines resulting from this multiscale and self-consistent framework will improve the performance of future SHJ cells as well as other passivating contact-based solar cells.

  10. Investigation of soil physical properties under Shorea peltata sym in Tengaroh Forest Reserve, Johor Bahru, Malaysia

    Directory of Open Access Journals (Sweden)

    Musalam Mohammed Abdalmoula

    2016-01-01

    Full Text Available Soil properties of tropical rain forest in Southeast Asia have been characterized by several researchers. However, empirical data on soil characteristics under rehabilitation program are still limited or even lacking. A study was conducted to characterize the soil physical properties under different densities of Shorea peltata species. The objective of the research was to determine the relationship between Shorea peltata species and soil physical properties. Twenty observational plots, 50 X 50 m namely, rare (A, low (B, moderate (C and high (D densities were established. Each plot was divided into 10 subplots. Five subplots were selected randomly. Soil samples were collected using auger at 0 - 15 cm, and core-ring at 0 - 10 cm depth. The results show that there was a significant difference among the groups. Analysis of the relationship between soil physical properties and site variables showed that moisture content, bulk density, particle density, silt and clay were the important factors in the distribution of Shorea peltata species in the study sites.

  11. Particle physics and QFT at the turn of the century: old principles with new concepts (an essay on local quantum physics)

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Bert [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik. E-mail: schroer@cbpf.br

    2000-04-01

    The present state of QFT is analyzed from a new viewpoint whose mathematical basis is the modular theory of von Neumann algebras. It physical consequences suggest new ways of dealing with interactions, symmetries, Hawking-Unruh thermal properties and possibly also extensions of the scheme of renormalized perturbation theory. Interactions are incorporated by using the fact that the S-matrix is a relative modular invariant of the interacting-relative to the incoming-net of wedge algebras. This new point of view allows many interesting comparisons with the standard quantization approach to QFT and is shown to be firmly rooted in the history of QFT. Its radical change of paradigm aspect becomes particularly visible in the quantum measurement problem. (author)

  12. Particle physics and QFT at the turn of the century: old principles with new concepts (an essay on local quantum physics))

    International Nuclear Information System (INIS)

    Schroer, Bert

    2000-04-01

    The present state of QFT is analyzed from a new viewpoint whose mathematical basis is the modular theory of von Neumann algebras. It physical consequences suggest new ways of dealing with interactions, symmetries, Hawking-Unruh thermal properties and possibly also extensions of the scheme of renormalized perturbation theory. Interactions are incorporated by using the fact that the S-matrix is a relative modular invariant of the interacting-relative to the incoming-net of wedge algebras. This new point of view allows many interesting comparisons with the standard quantization approach to QFT and is shown to be firmly rooted in the history of QFT. Its radical change of paradigm aspect becomes particularly visible in the quantum measurement problem. (author)

  13. Design Principles for resilient cyber-physical Early Warning Systems - Challenges, Experiences, Design Patterns, and Best Practices

    Science.gov (United States)

    Gensch, S.; Wächter, J.; Schnor, B.

    2014-12-01

    Early warning systems (EWS) are safety-critical IT-infrastructures that serve the purpose of potentially saving lives or assets by observing real-world phenomena and issuing timely warning products to authorities and communities. An EWS consists of sensors, communication networks, data centers, simulation platforms, and dissemination channels. The components of this cyber-physical system may all be affected by both natural hazards and malfunctions of components alike. Resilience engineering so far has mostly been applied to safety-critical systems and processes in transportation (aviation, automobile), construction and medicine. Early warning systems need equivalent techniques to compensate for failures, and furthermore means to adapt to changing threats, emerging technology and research findings. We present threats and pitfalls from our experiences with the German and Indonesian tsunami early warning system, as well as architectural, technological and organizational concepts employed that can enhance an EWS' resilience. The current EWS is comprised of a multi-type sensor data upstream part, different processing and analysis engines, a decision support system, and various warning dissemination channels. Each subsystem requires a set of approaches towards ensuring stable functionality across system layer boundaries, including also institutional borders. Not only must services be available, but also produce correct results. Most sensors are distributed components with restricted resources, communication channels and power supply. An example for successful resilience engineering is the power capacity based functional management for buoy and tide gauge stations. We discuss various fault-models like cause and effect models on linear pathways, interaction of multiple events, complex and non-linear interaction of assumedly reliable subsystems and fault tolerance means implemented to tackle these threats.

  14. Influence of physical and chemical dispersion on the biodegradation of oil under simulated marine conditions

    International Nuclear Information System (INIS)

    Swannell, R. P. J.; Daniel, F.; Croft, B. C.; Engelhardt, M. A.; Wilson, S.; Mitchell, D. J.; Lunel, T.

    1997-01-01

    Dispersion and biodegradation of oil was studied in marine microcosms designed to simulate oil dispersion at sea. Dispersion was studied using both Phase Doppler Particle Analyser and a Chamber Slide technique. In both natural and artificial seawater, oil addition was observed to encourage the growth of hydrocarbon-degrading bacteria in the presence of sufficient nitrogen and phosphorus. Results showed that microorganisms enhanced oil dispersion by colonizing physically-dispersed oil droplets and preventing re-coalescence with the surface slick. The addition of dispersants increased the rate of colonization as well as the number of degraded droplets. These results suggest that stimulation of physical dispersion by chemical means increase the rate of oil biodegradation under natural conditions. 25 refs., 3 tabs., 14 figs

  15. Physical scale modeling of single free head piles under lateral loading in cohesive soils

    Directory of Open Access Journals (Sweden)

    Edgar Leonardo Salamanca-Medina

    2017-06-01

    Full Text Available This paper presents the results of the small scale modeling of free head wood piles under horizontal loading in cohesive soils, tested in order to compare the results with analytical models proposed by various authors. Characteristic Load (CLM and P-Y Curves methods were used for the prediction of lateral deflections at the head of the piles and the method proposed by Broms for estimating the ultimate lateral load. These predictions were compared with the results of the physical modeling, obtaining a good approximation between them.

  16. Rhabdomyolysis Occurring under Statins after Intense Physical Activity in a Marathon Runner

    Directory of Open Access Journals (Sweden)

    Éric Toussirot

    2015-01-01

    Full Text Available Statins are widely used in the treatment of hypercholesterolemia and their side effects on muscles are well established. Conversely, data are sparse regarding the safety of this class of drugs in subjects who engage in sports, particularly those who have intense sports activity. We report the case of a marathon runner who presented with acute rhabdomyolysis during competition while being under rosuvastatin treatment. This case raises the question of the need for temporary discontinuation of statin therapy when intense physical activity is planned.

  17. Macrocrack propagation in concrete specimens under sustained loading: Study of the physical mechanisms

    International Nuclear Information System (INIS)

    Rossi, Pierre; Boulay, Claude; Tailhan, Jean-Louis; Martin, Eric; Desnoyers, Dominic

    2014-01-01

    This study presents a series of 4-point bending tests performed to describe the delayed behavior of unreinforced pre-cracked beams under low, moderate and high sustained loading levels. The deflection creep rate, the failure time and the load level were assessed. A linear relation, in a semi-log scale, was found for the deflection creep rate at high load levels. In addition, a linear relation, in a log–log scale, between the secondary deflection creep rate and failure time was observed. Besides, it was shown that the secondary creep deflection rate increases with the sustained loading level and the macrocrack propagation rate when macrocrack propagation occurs during the sustained loading. Physical mechanisms are proposed to explain these results and may be summarized as follows: the delayed behavior of an unreinforced cracked concrete specimen under sustained loading is mainly due to the cracking evolution, thus the creation of microcracks and/or the propagation of a macrocrack

  18. First-principles investigation of the structural, mechanical and thermodynamic properties of Al2Cu phase under various pressure and temperature conditions

    Science.gov (United States)

    Tian, Jinzhong; Zhao, Yuhong; Hou, Hua; Han, Peide

    2017-12-01

    The crystal structure, phase stability, mechanical and thermodynamic properties of the Al2Cu (θ), Al2Cu (θ‧) and Al2Cu (Ω) phases are studied by the first-principles method. The predicted lattice constants are consistent with the available literature data. θ, θ‧ and Ω phases are thermodynamically stable, and do not undergo any phase transition under pressure. The values of B for Ω are larger than that for θ and θ‧ phases, while the values of G for θ are smaller than that for Ω and θ‧ phases. The studies also reveal that pressure can improve the elastic anisotropy of the θ, θ‧ and Ω phases. The Debye temperature, heat capacity and thermal expansion coefficient for the phases are determined by the quasi-harmonic Debye model. Under identical conditions, the values of ΘD from high to low is in the following order: θ‧>Ω>θ. The heat capacity and thermal expansion coefficient for θ, θ‧ and Ω phases decrease with pressure when the temperature is kept constant. In contrast, thermal expansion coefficient α is more sensitive to any changes in pressure than any temperature change in the temperature range, 300-800 K.

  19. Lattice stabilities, mechanical and thermodynamic properties of Al3Tm and Al3Lu intermetallics under high pressure from first-principles calculations

    Science.gov (United States)

    Xu-Dong, Zhang; Wei, Jiang

    2016-02-01

    The effects of high pressure on lattice stability, mechanical and thermodynamic properties of L12 structure Al3Tm and Al3Lu are studied by first-principles calculations within the VASP code. The phonon dispersion curves and density of phonon states are calculated by using the PHONONPY code. Our results agree well with the available experimental and theoretical values. The vibrational properties indicate that Al3Tm and Al3Lu keep their dynamical stabilities in L12 structure up to 100 GPa. The elastic properties and Debye temperatures for Al3Tm and Al3Lu increase with the increase of pressure. The mechanical anisotropic properties are discussed by using anisotropic indices AG, AU, AZ, and the three-dimensional (3D) curved surface of Young’s modulus. The calculated results show that Al3Tm and Al3Lu are both isotropic at 0 GPa and anisotropic under high pressure. In the present work, the sound velocities in different directions for Al3Tm and Al3Lu are also predicted under high pressure. We also calculate the thermodynamic properties and provide the relationships between thermal parameters and temperature/pressure. These results can provide theoretical support for further experimental work and industrial applications. Project supported by the Scientific Technology Plan of the Educational Department of Liaoning Province and Liaoning Innovative Research Team in University, China (Grant No. LT2014004) and the Program for the Young Teacher Cultivation Fund of Shenyang University of Technology, China (Grant No. 005612).

  20. First Principles Study on Structure Stability and Mechanical Properties of YNi2B2C and LuNi2B2C under Pressure

    Directory of Open Access Journals (Sweden)

    Lili Liu

    2017-06-01

    Full Text Available The pressure effects on the lattice parameters and elastic constants of the tetragonal RNi 2 B 2 C (R=Y, Lu are investigated by means of the first principles. The predicted lattice constants and elastic constants of YNi 2 B 2 C and LuNi 2 B 2 C at 0 GPa agree well with the available data. By the elastic stability criteria under isotropic pressure, it is predicted that YNi 2 B 2 C and LuNi 2 B 2 C with tetragonal structure are not mechanically stable above 93 GPa and 50 GPa, respectively. Pugh’s modulus ratio, Poisson’s ratio, Vickers hardness, elastic anisotropy and Debye temperature of YNi 2 B 2 C in the pressure range of 0–100 GPa and LuNi 2 B 2 C in the pressure range of 0-60 GPa are further investigated. It is shown that the ductility and Debye temperature of tetragonal RNi 2 B 2 C (R=Y, Lu increase with increasing pressure, and LuNi 2 B 2 C is more ductile and lower Debye temperature than YNi 2 B 2 C under different pressures.

  1. First principles calculations of structural, elastic, electronic properties of Ir{sub 3}Zr with L1{sub 2} structure under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Na; Wang, Xueye, E-mail: wxueye@xtu.edu.cn; Wan, Yali

    2015-07-15

    The effects of pressure on the structural, elastic and electronic properties of Ir{sub 3}Zr are investigated by means of the first-principles calculations based on the density functional theory with generalized gradient approximation and local density approximation methods. The calculated lattice parameters and elastic modulus of Ir{sub 3}Zr at zero pressure are in good agreement with available experimental and theoretical results. The values of elastic constants (C{sub 11}, C{sub 12}, C{sub 44}), bulk modulus (B), shear modulus (G), Young modulus (E), Poisson's ratio (υ), anisotropy index (A) and Debye temperature (T{sub D}) present the linearly increasing dependences on the external pressure. Additionally, the B/G values exhibit an upward trend with increasing pressure, which means that higher pressure can improve its ductility. Ir{sub 3}Zr exhibits a brittle characteristic at zero pressure. When the pressure reaches 10 GPa, the Cauchy pressure and B/G value show ductile feature. In addition, the pressure-dependence behavior of density of states, Mulliken charge and bond length are analyzed. - Graphical abstract: Display Omitted - Highlights: • The elastic and electronic properties of Ir{sub 3}Zr under pressure are investigated. • The elastic constants, elastic moduli increase with the pressure increasing. • When the pressure reaches 10 GPa, Ir{sub 3}Zr changes from brittle to ductile. • Ir{sub 3}Zr remains as a stable structure and no structural transition under pressure.

  2. PETher - Physical Properties of Thermal Water under In-situ-Conditions

    Science.gov (United States)

    Herfurth, Sarah; Schröder, Elisabeth

    2016-04-01

    The objective of PETher, a research project funded by the German Federal Ministry for Economic Affairs and Energy (BMWi), is to experimentally determine thermo-physical properties (specific isobaric heat capacity, kinematic viscosity, density and thermal conductivity) of geothermal water in-situ-conditions (pressure, temperature, chemical composition including gas content of the brine) present in geothermal applications. Knowing these thermo-physical properties reduces the uncertainties with respect to estimating the thermal output and therefore the economic viability of the power plant. Up to now, only a limited number of measurements of selected physical properties have been made, usually under laboratory conditions and for individual geothermal plants. In-situ measured parameters, especially in the temperature range of 120°C and higher, at pressures of 20 bar and higher, as well as with a salinity of up to 250 g/l, are sparse to non-existing. Therefore, pure water properties are often used as reference data and for designing the power plant and its components. Currently available numerical models describing the thermo-physical properties are typically not valid for the conditions in geothermal applications and do not consider the substantial influence of the chemical composition of the thermal water. Also, actual geothermal waters have not been subject of detailed measurements systematically performed under operational conditions on a large-scale basis. Owing to the lack of reliable data, a validation of numerical models for investigating geothermal systems is not possible. In order to determine the dependency of the thermo-physical properties of geothermal water on temperature, pressure and salinity in-situ measurements are conducted. The measurements are taking place directly at several geothermal applications located in Germany's hydrogeothermal key regions. In order to do this, a mobile testing unit was developed and refined with instruments specifically

  3. Physical optics principles and practices

    CERN Document Server

    Al-Azzawi, Abdul

    2006-01-01

    WAVESIntroductionThe Nature of WavesTypes of WavesCharacteristics of WavesTrigonometric Notation of WavesSimple Harmonic MotionPeriod and Frequency of Simple Harmonic MotionThe Simple PendulumExperimental WorkList of ReferencesAppendicesFurther ReadingINTERFERENCE AND DIFFRACTIONIntroductionInterference of LightYoung's Double-Slit ExperimentWave Phase Changes Due to ReflectionInterference in Thin FilmsNewton's RingsThin Film ApplicationsDiffractionExperimental WorkList of ReferencesAppendicesFurther ReadingTHE DIFFRACTION GRATINGIntroductionDiffraction GratingsProfiles of GratingsPlanar Diffraction GratingsConcave GratingsCharacteristics of GratingsEfficiency of Diffraction GratingsManufacturing of Diffraction GratingsDiffraction Grating InstrumentsExperimental WorkList of ReferencesAppendicesFurther ReadingINTERFEROMETERSIntroductionThe Michelson InterferometerThe Mach-Zehnder InterferometerThe Twyman-Green InterferometerThe Fizeau InterferometerThe Fabry-Pérot InterferometerOther types of InterferometersEx...

  4. Principles of condensed matter physics

    National Research Council Canada - National Science Library

    Chaikin, Paul M; Lubensky, T. C

    1995-01-01

    ... of liquids, liquid crystals, quasicrystals, crystalline solids, magnetically ordered systems and amorphous solids are investigated in terms of their symmetry, generalized rigidity, hydrodynamics and topological defect structure. Written in a clear and pedagogic style, the book contains proble~s at the end of each chapter and exten...

  5. Temporal Variability of Physical Properties on an Aquic Argiudoll under no Tillage

    Science.gov (United States)

    Castiglione, M. G.; Sasal, M. C.; Wilson, M. G.; Paz González, A.; Oszust, J. D.

    2012-04-01

    Practices for the implementation and development of crops affect soil properties and processes in space and time with consequences for the accumulation and movement of water, nutrients and pollutants, which affects plant growth. The aim of this study was to determine the temporal variability of soil physical properties and its link with the infiltration process, on an Aquic Argiudoll of the Argentine Pampas under no-till cultivation. Sampling was performed during six dates in the INTA EEA Paraná (Entre Ríos, Argentina), in the course of the succession of wheat/ soybean-corn. In each of those dates, rain simulations were performed under covered and uncovered soil. From these results it was determined the saturated hydraulic conductivity (Ks), the runoff coefficient (EC), the accumulated rainfall up to ponding (Tp), the accumulated rainfall to reach the steady state infiltration rate (TI) and the decline slope of the infiltration rate (Pd). Also we determine: the initial soil water content (HI), bulk density (Dap), volume occupied by pores larger than 50 µm (> 50), volume occupied by pores between 10 and 50 µm (10-50), soil physical quality index (S) and structural stability (CDMP). On three dates HI was approximately 11%, two were between 22 and 27% and in the remaining time HI was 36%. Despite these variations we don't observed significant changes in most soil physical properties associated with the structure and pore size. However, we could prove significant differences between dates in Ks and EC, both on bare and cover soil. At the same time, differences in these parameters between coverage degrees were significant only in two dates. The HI affected the variability of Ks results. Also Ks ratio between covered and uncovered soil improved with HI increment, except for HI equal to 36%. We found highly significant linkage between Ks, CE and Pd with HI. This study reveals the importance of the temporal dynamics of water movement in this Aquic Argiudoll, although

  6. On the problem of studying physical properties of rock collectors under conditions modelling layer ones

    Energy Technology Data Exchange (ETDEWEB)

    Petkevich, G.I.

    1972-01-01

    A review is given of the state in studying physical properties of rock collectors under conditions modelling the layer ones. From the theoretical point of view, this direction is determined as petrophysics of multiphase systems and from the practical, as oil field petrophysics. The following aspects of the problem are considered: models of porous media, thermodynamic conditions of deformation process, parameters of stressed state of porous deformed media, and analysis of experimental data. To describe collector behavior under thermodynamic conditions of natural occurrence, it is necessary to construct the model of the porous deformed medium. In connection with heterogeneity and multiphase character of rock collectors, they may be considered as differential-elastic media, and to characterize the stressed state such indices as coefficients of compressibility of skeleton, solid and liquid phase, as well as coefficients of pore compressibility, relaxation, structural parameter, etc. may be used. It is emphasized that only reversable (elastic) parameter changes are studied under laboratory conditions. The results of laboratory measurements of collector parameters are summarized on the basis of different researcher data. (54 refs.)

  7. Physical principles demonstrate that the biceps femoris muscle relative to the other hamstring muscles exerts the most force: implications for hamstring muscle strain injuries.

    Science.gov (United States)

    Dolman, Bronwyn; Verrall, Geoffrey; Reid, Iain

    2014-07-01

    Of the hamstring muscle group the biceps femoris muscle is the most commonly injured muscle in sports requiring interval sprinting. The reason for this observation is unknown. The objective of this study was to calculate the forces of all three hamstring muscles, relative to each other, during a lengthening contraction to assess for any differences that may help explain the biceps femoris predilection for injury during interval sprinting. To calculate the displacement of each individual hamstring muscle previously performed studies on cadaveric anatomical data and hamstring kinematics during sprinting were used. From these displacement calculations for each individual hamstring muscle physical principles were then used to deduce the proportion of force exerted by each individual hamstring muscle during a lengthening muscle contraction. These deductions demonstrate that the biceps femoris muscle is required to exert proportionally more force in a lengthening muscle contraction relative to the semimembranosus and semitendinosus muscles primarily as a consequence of having to lengthen over a greater distance within the same time frame. It is hypothesized that this property maybe a factor in the known observation of the increased susceptibility of the biceps femoris muscle to injury during repeated sprints where recurrent higher force is required.

  8. A survey of variational principles

    International Nuclear Information System (INIS)

    Lewins, J.D.

    1993-01-01

    In this article survey of variational principles has been given. Variational principles play a significant role in mathematical theory with emphasis on the physical aspects. There are two principals used i.e. to represent the equation of the system in a succinct way and to enable a particular computation in the system to be carried out with greater accuracy. The survey of variational principles has ranged widely from its starting point in the Lagrange multiplier to optimisation principles. In an age of digital computation, these classic methods can be adapted to improve such calculations. We emphasize particularly the advantage of basic finite element methods on variational principles. (A.B.)

  9. New class of photocatalytic materials and a novel principle for efficient water splitting under infrared and visible light: MgB2 as unexpected example.

    Science.gov (United States)

    Kravets, V G; Grigorenko, A N

    2015-11-30

    Water splitting is unanimously recognized as environment friendly, potentially low cost and renewable energy solution based on the future hydrogen economy. Especially appealing is photocatalytic water splitting whereby a suitably chosen catalyst dramatically improves efficiency of the hydrogen production driven by direct sunlight and allows it to happen even at zero driving potential. Here, we suggest a new class of stable photocatalysts and the corresponding principle for catalytic water splitting in which infrared and visible light play the main role in producing the photocurrent and hydrogen. The new class of catalysts - ionic or covalent binary metals with layered graphite-like structures - effectively absorb visible and infrared light facilitating the reaction of water splitting, suppress the inverse reaction of ion recombination by separating ions due to internal electric fields existing near alternating layers, provide the sites for ion trapping of both polarities, and finally deliver the electrons and holes required to generate hydrogen and oxygen gases. As an example, we demonstrate conversion efficiency of ~27% at bias voltage Vbias = 0.5V for magnesium diboride working as a catalyst for photoinduced water splitting. We discuss its advantages over some existing materials and propose the underlying mechanism of photocatalytic water splitting by binary layered metals.

  10. First-principle study of the structural, electronic, and optical properties of cubic InN{sub x}P{sub 1-x} ternary alloys under hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Hattabi, I. [Ibn Khaldoun Univ. de Tiaret (Algeria). Lab. Synthese et Catalyse; Abdiche, A.; Riane, R. [Sidi-bel-Abbes Univ. (Algeria). Applied Materials Lab.; Moussa, R. [Sidi-bel-Abbes Univ. (Algeria). Physic Dept.; Hadji, K. [Ibn Khaldoun Univ. de Tiaret (Algeria). Science and Technology Dept.; Soyalp, F. [Yuezuencue Yil Univ., Van (Turkey). Dept. of Physics; Varshney, Dinesh [Devi Ahilya Univ., Indore (India). Materials Science Lab.; Syrotyuk, S.V. [National Univ. ' Lviv Polytechnic' , Lviv (Ukraine). Semiconductor Electronics Dept.; Khenata, R. [Mascara Univ. (Algeria). Lab. de Physique Quantique et de Modelisation Mathematique (LPQ3M)

    2016-07-01

    In this article, we present results of the first-principle study of the structural, electronic, and optical properties of the InN, InP binary compounds and their related ternary alloy InN{sub x}P{sub 1-x} in the zinc-blend (ZB) phase within a nonrelativistic full potential linearised augmented plan wave (FP-LAPW) method using Wien2k code based on the density functional theory (DFT). Different approximations of exchange-correlation energy were used for the calculation of the lattice constant, bulk modulus, and first-order pressure derivative of the bulk modulus. Whereas the lattice constant decreases with increasing nitride composition x. Our results present a good agreement with theoretical and experimental data. The electronic band structures calculated using Tran-Blaha-modified Becke-Johnson (TB-mBJ) approach present a direct band gap semiconductor character for InN{sub x}P{sub 1-x} compounds at different x values. The electronic properties were also calculated under hydrostatic pressure for (P=0.00, 5.00, 10.0, 15.0, 20.0, 25.0 GPa) where it is found that the InP compound change from direct to indirect band gap at the pressure P≥7.80 GPa. Furthermore, the pressure effect on the dielectric function and the refractive index was carried out. Results obtained in our calculations present a good agreement with available theoretical reports and experimental data.

  11. First-Principle Study of the Structural, Electronic, and Optical Properties of Cubic InNxP1-x Ternary Alloys under Hydrostatic Pressure

    Science.gov (United States)

    Hattabi, I.; Abdiche, A.; Moussa, R.; Riane, R.; Hadji, K.; Soyalp, F.; Varshney, Dinesh; Syrotyuk, S. V.; Khenata, R.

    2016-09-01

    In this article, we present results of the first-principle study of the structural, electronic, and optical properties of the InN, InP binary compounds and their related ternary alloy InNxP1-x in the zinc-blend (ZB) phase within a nonrelativistic full potential linearised augmented plan wave (FP-LAPW) method using Wien2k code based on the density functional theory (DFT). Different approximations of exchange-correlation energy were used for the calculation of the lattice constant, bulk modulus, and first-order pressure derivative of the bulk modulus. Whereas the lattice constant decreases with increasing nitride composition x. Our results present a good agreement with theoretical and experimental data. The electronic band structures calculated using Tran-Blaha-modified Becke-Johnson (TB-mBJ) approach present a direct band gap semiconductor character for InNxP1-x compounds at different x values. The electronic properties were also calculated under hydrostatic pressure for (P=0.00, 5.00, 10.0, 15.0, 20.0, 25.0 GPa) where it is found that the InP compound change from direct to indirect band gap at the pressure P≥7.80 GPa. Furthermore, the pressure effect on the dielectric function and the refractive index was carried out. Results obtained in our calculations present a good agreement with available theoretical reports and experimental data.

  12. Selected soil physical and hydraulic properties for different crop successions under no tillage

    Science.gov (United States)

    Sasal, M. C.; Castiglioni, M.; Paz-Ferreiro, J.; Wilson, M. G.; Oszust, J.

    2009-04-01

    No tillage is now widely widespread in Argentina in response to several circumstances, including limited runoff and a drop in soil erosion. Crop residues left on the soil surface help both natural rainfall and irrigation water infiltrate and also limits evaporation, conserving water for plant growth. This notwithstanding, wide differences in runoff rates between crop succession have been observed under no tillage. The aim of this work was to assess the effect of the main crop successions of Entre Ríos province, Argentina on selected soil physic and hydraulic properties. Results obtained on no-till plots were compared with those recorded on a 10-years old grassland plot and on a conventionally tilled plot left bare, both of them taken as references. The study soil was classified as an Aquic Argiudoll. Treatments were: maize and soybean, both cropped as monoculture, succession wheat/soybean or wheat/maize, grassland and conventionally tilled soil left bare. Soil runoff was recorded on experimental plots 100 m2 in surface. Saturated hydraulic conductivity (Khc) and sorptivity were measured in field conditions using a disc permeameter. Bulk density (Bd), saturated hydraulic conductivity (Kh) total porosity (TP) and pore size distributions were determined on undisturbed cores sampled at the 0-4 and 4-8 cm depth with five replications. Maximum water losses were recorded in bare soils conventionally tilled. Under maize and soybean monocultures water losses were six time higher than under grassland. Water losses under successions wheat/soybean-maize were lower than under monoculture but not significantly different. Field saturated hydraulic conductivity (Khc) was highest under grassland and the remaining treatments don't showed significant differences. Differences in sorptivity between plots were not significantly different. A significant relationship was found between saturated hydraulic conductivity measured in field conditions (Khc) and determined in soil cores (Kh

  13. How do soil physical conditions for crop growth vary over time under established contrasting tillage regimes?

    Science.gov (United States)

    Hallett, Paul; Stobart, Ron; Valentine, Tracy; George, Timothy; Morris, Nathan; Newton, Adrian; McKenzie, Blair

    2014-05-01

    When plant breeders develop modern cereal varieties for the sustainable intensification of agriculture, insufficient thought is given to the impact of tillage on soil physical conditions for crop production. In earlier work, we demonstrated that barley varieties that perform best in ploughed soil (the approach traditionally used for breeding trials) were not the same as those performing best under shallow non-inversion or zero-tillage. We also found that the Quantitative Trait Loci (QTL) associated with improved phosphorus uptake, and hence useful for marker assisted breeding, were not robust between different tillage regimes. The impact of the soil environment had greater impact than the genetics in GxE interactions. It is obvious that soil tillage should be considered when breeding the next generation of crops. Tillage may also have important impacts on carbon storage, but we found that despite greater soil carbon at shallow depths under non-inversion tillage, the carbon stored throughout the soil profile was not affected by tillage. Studies on soil tillage impacts to crop productivity and soil quality are often performed in one season, on single sites that have had insufficient time to develop. Our current research explores multiple sites, on different soils, with temporal measurements of soil physical conditions under contrasting tillage regimes. We use the oldest established contemporary tillage experiments in the United Kingdom, with all sites sharing ploughed and shallow (7cm) non-inversion tillage treatments. In eastern Scotland (Mid Pilmore), the site also has zero tillage and deep ploughing (40 cm) treatments, and was established 11 years ago. In east England there are two sites, both also having a deep non-inversion tillage treatment, and they were established 6 (New Farm Systems) and 8 (STAR) years ago. We measure a range of crop and soil properties at sowing, one month after sowing and post-harvest, including rapid lab based assays that allow high

  14. Induced Sporicidal Activity of Chlorhexidine against Clostridium difficile Spores under Altered Physical and Chemical Conditions

    Science.gov (United States)

    Nerandzic, Michelle M.; Donskey, Curtis J.

    2015-01-01

    Background Chlorhexidine is a broad-spectrum antimicrobial commonly used to disinfect the skin of patients to reduce the risk of healthcare-associated infections. Because chlorhexidine is not sporicidal, it is not anticipated that it would have an impact on skin contamination with Clostridium difficile, the most important cause of healthcare-associated diarrhea. However, although chlorhexidine is not sporicidal as it is used in healthcare settings, it has been reported to kill spores of Bacillus species under altered physical and chemical conditions that disrupt the spore’s protective barriers (e.g., heat, ultrasonication, alcohol, or elevated pH). Here, we tested the hypothesis that similarly altered physical and chemical conditions result in enhanced sporicidal activity of chlorhexidine against C. difficile spores. Principal Findings C. difficile spores became susceptible to heat killing at 80°C within 15 minutes in the presence of chlorhexidine, as opposed to spores suspended in water which remained viable. The extent to which the spores were reduced was directly proportional to the concentration of chlorhexidine in solution, with no viable spores recovered after 15 minutes of incubation in 0.04%–0.0004% w/v chlorhexidine solutions at 80°C. Reduction of spores exposed to 4% w/v chlorhexidine solutions at moderate temperatures (37°C and 55°C) was enhanced by the presence of 70% ethanol. However, complete elimination of spores was not achieved until 3 hours of incubation at 55°C. Elevating the pH to ≥9.5 significantly enhanced the killing of spores in either aqueous or alcoholic chlorhexidine solutions. Conclusions Physical and chemical conditions that alter the protective barriers of C. difficile spores convey sporicidal activity to chlorhexidine. Further studies are necessary to identify additional agents that may allow chlorhexidine to reach its target within the spore. PMID:25861057

  15. Contribution of underlying processes to improved visuospatial working memory associated with physical activity.

    Science.gov (United States)

    Ji, Qingchun; Wang, Yingying; Guo, Wei; Zhou, Chenglin

    2017-01-01

    Working memory is critical for various cognitive processes and can be separated into two stages: short-term memory storage and manipulation processing. Although previous studies have demonstrated that increased physical activity (PA) improves working memory and that males outperform females on visuospatial working memory tasks, few studies have determined the contribution of the two underlying stages to the visuospatial working memory improvement associated with PA. Thus, the aims of the present study were to verify the relationship between physical activity and visuospatial working memory, determine whether one or both stages were affected by PA, and investigate any sex differences. A total of 56 undergraduate students were recruited for this study. Their scores on the International Physical Activity Questionnaire (IPAQ) were used to separate them into either a lower PA ( n  = 26; IPAQ score ≤3,000 metabolic equivalent [MET]-min/week) or higher PA ( n  = 30; IPAQ score >3,000 MET-min/week) group. Participants were required to complete three tasks: a visuospatial working memory task, a task that examines the short-term memory storage stage, and a mental rotation task that examines the active manipulation stage. Participants in the higher PA group maintained similar accuracy but displayed significantly faster reaction times (RT) than those in the lower PA group on the visuospatial working memory and manipulation tasks. By contrast, no difference was observed between groups on the short-term memory storage task. In addition, no effects of sex were detected. Our results confirm that PA was positively to visuospatial working memory and that this positive relationship was associated with more rapid cognitive processing during the manipulation stage, with little or no relationship between PA and the memory storage stage of visuospatial working memory.

  16. THE DEVELOPMENT OF STUDENTS’ MOTIVATIONAL DIMENSIONS UNDER THE PHYSICAL EDUCATION EXPERIMENTAL PROGRAMME

    Directory of Open Access Journals (Sweden)

    Said Hasanbegović

    2014-04-01

    Full Text Available This study shows the development of some motivational dimensions of secondary school students when they are treated by the experimental way of teaching. The study was conducted on a sample of 240 pupils of The Secondary School Banovici, out of which 124 males and 116 females. The pupils were divided into two groups. The first group consisted of 120 pupils divided into four sections, out of which 73 males and 47 females. This is the control group. The second group also consisted of 120 pupils divided into four sections, out of which 51 male and 69 females. This group was subjected to the experimental way of teaching and thus represents the experimental group. Results show the changes in pupils’ motivational characteristics under the influence of innovative educational content that are reflected through their activities and final attitudes on the physical education value. The discriminate analysis revealed the statistically important differences between pupils that are treated by the experimental program compared to students treated by traditional program in terms of motivation in physical education classes (PE classes. However, the study, in some way, solves the problem of inactivity and pupils’ lack of interest for the PE classes, i.e. it suggests the pupils’ possible development of motivation for work using the appropriate educational contents.

  17. [Physics of materials and female stress urinary continence: New concepts: I) Elasticity under bladder].

    Science.gov (United States)

    Guerquin, B

    2015-09-01

    Improving the understanding of the adaptation to stress of urinary continence. A transversal analysis between physics of materials and the female anatomy. Laws of physics of the materials and of their viscoelastic behavior are applied to the anatomy of the anterior vaginal wall. The anterior vaginal wall may be divided into two segments of different viscoelastic behavior, the vertical segment below the urethra and the horizontal segment below the bladder. If the urethra gets crushed on the first segment according to the hammock theory, the crushing of the bladder on the second segment is, on the other hand, damped by its important elasticity. The importance of this elasticity evokes an unknown function: damping under the bladder that moderates and delays the increase of intravesical pressure. This damping function below the bladder is increased in the cystocele, which is therefore a continence factor; on the other hand, it is impaired in obesity, which is therefore a factor of SUI. It is necessary to include in the theory of stress continence, the notion of a damping function below the bladder. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  18. Synchronized mammalian cell culture: part I--a physical strategy for synchronized cultivation under physiological conditions.

    Science.gov (United States)

    Barradas, Oscar Platas; Jandt, Uwe; Becker, Max; Bahnemann, Janina; Pörtner, Ralf; Zeng, An-Ping

    2015-01-01

    Conventional analysis and optimization procedures of mammalian cell culture processes mostly treat the culture as a homogeneous population. Hence, the focus is on cell physiology and metabolism, cell line development, and process control strategy. Impact on cultivations caused by potential variations in cellular properties between different subpopulations, however, has not yet been evaluated systematically. One main cause for the formation of such subpopulations is the progress of all cells through the cell cycle. The interaction of potential cell cycle specific variations in the cell behavior with large-scale process conditions can be optimally determined by means of (partially) synchronized cultivations, with subsequent population resolved model analysis. Therefore, it is desirable to synchronize a culture with minimal perturbation, which is possible with different yield and quality using physical selection methods, but not with frequently used chemical or whole-culture methods. Conventional nonsynchronizing methods with subsequent cell-specific, for example, flow cytometric analysis, can only resolve cell-limited effects of the cell cycle. In this work, we demonstrate countercurrent-flow centrifugal elutriation as a useful physical method to enrich mammalian cell populations within different phases of a cell cycle, which can be further cultivated for synchronized growth in bioreactors under physiological conditions. The presented combined approach contrasts with other physical selection methods especially with respect to the achievable yield, which makes it suitable for bioreactor scale cultivations. As shown with two industrial cell lines (CHO-K1 and human AGE1.HN), synchronous inocula can be obtained with overall synchrony degrees of up to 82% in the G1 phase, 53% in the S phase and 60% in the G2/M phase, with enrichment factors (Ysync) of 1.71, 1.79, and 4.24 respectively. Cells are able to grow with synchrony in bioreactors over several cell cycles. This

  19. Microbial and physical properties as indicators of sandy soil quality under cropland and grassland

    Science.gov (United States)

    Frac, Magdalena; Lipiec, Jerzy; Usowicz, Boguslaw; Oszust, Karolina; Brzezinska, Malgorzata

    2017-04-01

    Land use is one of the key factor driving changes in soil properties influencing on soil health and quality. Microbial diversity and physical properties are sensitive indicators for assessing soil health and quality. The alterations of microbial diversity and physical properties following land use changes have not been sufficiently elucidated, especially for sandy soils. We investigated microbial diversity indicators including fungal communities composition and physical properties of sandy acid soil under cropland and more than 20-yr-old grassland (after cropland) in Trzebieszów, Podlasie Region, Poland (N 51° 59' 24", E 22° 33' 37"). The study included four depths within 0-60 cm. Microbial genetic diversity was assessed by terminal restriction fragment length polymorphism (t-RFLP) analysis, fungal community composition was evaluated by next generation sequencing (NGS) analysis and functional diversity was determined by Biolog EcoPlate method. Overall microbial activity was assessed by soil enzymes (dehydrogenases, β-glucosidase) and respiration test. At the same places soil texture, organic carbon content, pH, bulk density, water holding capacity were determined. Our results showed that grassland soil was characterized by higher activity of soil enzymes than cropland. The average well color development of soil microorganisms, the microbial functional diversity and the number of carbon source utilization were significantly affected by land use type and were differentiated among soil depths. In grassland compared to cropland soil a significant increase of carboxylic acids and decrease of amino acids utilization was observed. The quantitative and qualitative differences were found in community of ammonia oxidizing archaea in cropland and grassland soil. The results of fungal community composition help to explain the soil health of grassland and cropland based on the appearance of phytopathogenic and antagonistic fungi. In general bulk density and field water

  20. Secure Fusion Estimation for Bandwidth Constrained Cyber-Physical Systems Under Replay Attacks.

    Science.gov (United States)

    Chen, Bo; Ho, Daniel W C; Hu, Guoqiang; Yu, Li

    2017-07-03

    State estimation plays an essential role in the monitoring and supervision of cyber-physical systems (CPSs), and its importance has made the security and estimation performance a major concern. In this case, multisensor information fusion estimation (MIFE) provides an attractive alternative to study secure estimation problems because MIFE can potentially improve estimation accuracy and enhance reliability and robustness against attacks. From the perspective of the defender, the secure distributed Kalman fusion estimation problem is investigated in this paper for a class of CPSs under replay attacks, where each local estimate obtained by the sink node is transmitted to a remote fusion center through bandwidth constrained communication channels. A new mathematical model with compensation strategy is proposed to characterize the replay attacks and bandwidth constrains, and then a recursive distributed Kalman fusion estimator (DKFE) is designed in the linear minimum variance sense. According to different communication frameworks, two classes of data compression and compensation algorithms are developed such that the DKFEs can achieve the desired performance. Several attack-dependent and bandwidth-dependent conditions are derived such that the DKFEs are secure under replay attacks. An illustrative example is given to demonstrate the effectiveness of the proposed methods.

  1. Radiation physics for medical physicists

    CERN Document Server

    Podgorsak, Ervin B

    2016-01-01

    This textbook summarizes the basic knowledge of atomic, nuclear, and radiation physics that professionals working in medical physics and biomedical engineering need for efficient and safe use of ionizing radiation in medicine. Concentrating on the underlying principles of radiation physics, the textbook covers the prerequisite knowledge for medical physics courses on the graduate and post-graduate levels in radiotherapy physics, radiation dosimetry, imaging physics, and health physics, thus providing the link between elementary undergraduate physics and the intricacies of four medical physics specialties: diagnostic radiology physics, nuclear medicine physics, radiation oncology physics, and health physics. To recognize the importance of radiation dosimetry to medical physics three new chapters have been added to the 14 chapters of the previous edition. Chapter 15 provides a general introduction to radiation dosimetry. Chapter 16 deals with absolute radiation dosimetry systems that establish absorbed dose or ...

  2. Principle extremum of full action

    Directory of Open Access Journals (Sweden)

    Solomon I. Khmelnik

    2011-10-01

    Full Text Available A new variational principle extremum of full action is proposed, which extends the Lagrange formalism on dissipative systems. It is shown that this principle is applicable in electrical engineering, electrodynamics, mechanics and hydrodynamics, taking into account the friction forces. The proposed variational principle may be considered as a new formalism used as an universal method of physical equations derivation, and also as a method for solving these equations.

  3. Teaching/learning principles

    Science.gov (United States)

    Hankins, D. B.; Wake, W. H.

    1981-01-01

    The potential remote sensing user community is enormous, and the teaching and training tasks are even larger; however, some underlying principles may be synthesized and applied at all levels from elementary school children to sophisticated and knowledgeable adults. The basic rules applying to each of the six major elements of any training course and the underlying principle involved in each rule are summarized. The six identified major elements are: (1) field sites for problems and practice; (2) lectures and inside study; (3) learning materials and resources (the kit); (4) the field experience; (5) laboratory sessions; and (6) testing and evaluation.

  4. 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...

  5. Mach's Principle

    Indian Academy of Sciences (India)

    that allows one to write down the laws of motion and arrive at the concept of inertia is somehow intimately re- lated to the background of distant parts of the universe. This argument is known as `Mach's principle' and we will analyse its implications further. When expressed in the framework of the absolute space,. Newton's ...

  6. Safety Principles

    Directory of Open Access Journals (Sweden)

    V. A. Grinenko

    2011-06-01

    Full Text Available The offered material in the article is picked up so that the reader could have a complete representation about concept “safety”, intrinsic characteristics and formalization possibilities. Principles and possible strategy of safety are considered. A material of the article is destined for the experts who are taking up the problems of safety.

  7. Using Isomorphic Problems to Learn Introductory Physics

    Science.gov (United States)

    Lin, Shih-Yin; Singh, Chandralekha

    2011-01-01

    In this study, we examine introductory physics students' ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. Three hundred sixty-two students from a calculus-based and an algebra-based introductory physics course were given a quiz in the…

  8. [Response of Sediment Micro Environment and Micro Interface to Physical Disturbance Intensity Under the Disturbance of Chironomus plumosus].

    Science.gov (United States)

    Shi, Xiao-dan; Li, Yong; Li, Da-peng; Wang, Ren; Deng, Meng; Huang, Yong

    2015-05-01

    The response of sediment micro environment and micro intertace to physical disturbance intensity under the physical and Chironomus plumosus disturbance was investigated by means of sediment Rhizon samplers and Unisense micro sensor system. The sediment and overlying water were taken from Meiliang bay of Taihu Lake. The results showed that the OPD reached up to 12.1 mm under the high intensity (240 r · min(-1)), while it was higher than 3. 8. mm under low intensity (60 r · min(-1)). The TOE, the difference of TOE and DOE, OPD, ORP and the difference of DO spatial distribution were all positively correlated with the physical disturbance intensity. The increasing magnitude and range of pH as well as the decreasing magnitude and range of ferrous followed the same response tendency. Within the 0-6 cm sediment, the water content and porosity as well as the microbial activity at the same depth increased with the increase of physical disturbance intensity. In addition, the degree of response of the above parameters to the physical disturbance intensity was weakened with the increase of sediment depth. It was suggested that Chironomus plumosus dug more and deeper galleries under high intensity physical disturbance. Therefore, the sediment micro environment and micro interface were transformed in the vertical direction of the sediment.

  9. Engineering physics

    CERN Document Server

    Mukherji, Uma

    2015-01-01

    ENGINEERING PHYSICS is designed as a textbook for first year engineering students of a two semester course in Applied Physics according to new revised syllabus. However the scope of this book is not only limited to undergraduate engineering students and science students, it can also serve as a reference book for practicing scientists.Advanced technological topics like LCD, Squid, Maglev system, Electron microscopes, MRI, Photonics - Photonic fibre, Nano-particles, CNT, Quantum computing etc., are explained with basic underlying principles of Physics.This text explained following topics with numerous solved, unsolved problems and questions from different angles. Part-I contains crystal structure, Liquid crystal, Thermo-electric effect, Thermionic emission, Ultrasonic, Acoustics, semiconductor and magnetic materials. Whereas Part-2 contains Optics, X-rays, Electron optics, Dielectric materials, Quantum Physics and Schrodinger wave equation, Laser, Fibre-optics and Holography, Radio-activity, Super-conductivity,...

  10. The Curtin–Hammett Principle

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 2. The Curtin–Hammett Principle: A Qualitative Understanding. Suchandra Chakraborty Chandan Saha ... Keywords. Organic chemistry, qualitative physical interpretation, history, philos ophy, applic ations in chemistry, kinetic quenching.

  11. Physical-chemical and microbiological changes in Cerrado Soil under differing sugarcane harvest management systems.

    Science.gov (United States)

    Rachid, Caio T C C; Piccolo, Marisa C; Leite, Deborah Catharine A; Balieiro, Fabiano C; Coutinho, Heitor Luiz C; van Elsas, Jan Dirk; Peixoto, Raquel S; Rosado, Alexandre S

    2012-08-08

    Sugarcane cultivation plays an important role in Brazilian economy, and it is expanding fast, mainly due to the increasing demand for ethanol production. In order to understand the impact of sugarcane cultivation and management, we studied sugarcane under different management regimes (pre-harvest burn and mechanical, unburnt harvest, or green cane), next to a control treatment with native vegetation. The soil bacterial community structure (including an evaluation of the diversity of the ammonia oxidizing (amoA) and denitrifying (nirK) genes), greenhouse gas flow and several soil physicochemical properties were evaluated. Our results indicate that sugarcane cultivation in this region resulted in changes in several soil properties. Moreover, such changes are reflected in the soil microbiota. No significant influence of soil management on greenhouse gas fluxes was found. However, we did find a relationship between the biological changes and the dynamics of soil nutrients. In particular, the burnt cane and green cane treatments had distinct modifications. There were significant differences in the structure of the total bacterial, the ammonia oxidizing and the denitrifying bacterial communities, being that these groups responded differently to the changes in the soil. A combination of physical and chemical factors was correlated to the changes in the structures of the total bacterial communities of the soil. The changes in the structures of the functional groups follow a different pattern than the physicochemical variables. The latter might indicate a strong influence of interactions among different bacterial groups in the N cycle, emphasizing the importance of biological factors in the structuring of these communities. Sugarcane land use significantly impacted the structure of total selected soil bacterial communities and ammonia oxidizing and denitrifier gene diversities in a Cerrado field site in Central Brazil. A high impact of land use was observed in soil under

  12. Physical-chemical and microbiological changes in Cerrado Soil under differing sugarcane harvest management systems

    Directory of Open Access Journals (Sweden)

    Rachid Caio TCC

    2012-08-01

    Full Text Available Abstract Background Sugarcane cultivation plays an important role in Brazilian economy, and it is expanding fast, mainly due to the increasing demand for ethanol production. In order to understand the impact of sugarcane cultivation and management, we studied sugarcane under different management regimes (pre-harvest burn and mechanical, unburnt harvest, or green cane, next to a control treatment with native vegetation. The soil bacterial community structure (including an evaluation of the diversity of the ammonia oxidizing (amoA and denitrifying (nirK genes, greenhouse gas flow and several soil physicochemical properties were evaluated. Results Our results indicate that sugarcane cultivation in this region resulted in changes in several soil properties. Moreover, such changes are reflected in the soil microbiota. No significant influence of soil management on greenhouse gas fluxes was found. However, we did find a relationship between the biological changes and the dynamics of soil nutrients. In particular, the burnt cane and green cane treatments had distinct modifications. There were significant differences in the structure of the total bacterial, the ammonia oxidizing and the denitrifying bacterial communities, being that these groups responded differently to the changes in the soil. A combination of physical and chemical factors was correlated to the changes in the structures of the total bacterial communities of the soil. The changes in the structures of the functional groups follow a different pattern than the physicochemical variables. The latter might indicate a strong influence of interactions among different bacterial groups in the N cycle, emphasizing the importance of biological factors in the structuring of these communities. Conclusion Sugarcane land use significantly impacted the structure of total selected soil bacterial communities and ammonia oxidizing and denitrifier gene diversities in a Cerrado field site in Central Brazil

  13. Effect of L-carnitine Supplementation on Nutritional Status and Physical Performance Under Calorie Restriction.

    Science.gov (United States)

    Jain, Swati; Singh, Som Nath

    2015-04-01

    L-carnitine is popular as a potential ergogenic aid because of its role in the conversion of fat into energy. The present study was undertaken to investigate the effect of short term supplementation of L-carnitine on metabolic markers and physical efficiency tests under short term calorie restriction. Male albino rats were divided into four groups (n = 12 in each)-control, calorie restricted (CR for 5 days, 25 % of basal food intake), L-carnitine supplemented (CAR, given orally for 5 days at a dose of 100 mg/kg), CR with L-carnitine supplementation (CR + CAR). Food intake and body weight of the rats were measured along with biochemical variables like blood glucose, tissue glycogen, plasma and muscle protein and enzymatic activities of CPT-1 (carnitine palmitoyl transferase-1) and AMP kinase. Results demonstrated that L-carnitine caused marked increase in muscle glycogen, plasma protein, CPT-1 activity and swim time of rats (P supplementation. In addition to the substantive effects caused by CR alone, L-carnitine under CR significantly affected muscle glycogen, plasma protein, CPT-1 activity and AMP kinase (P < 0.05). Short term CR along with L-carnitine also resulted in increased swim time of rats than control, CR and L-carnitine treated rats (P < 0.05). The present study was an attempt towards developing an approach for better adherence to dietary restriction regimen, with the use of L-carnitine.

  14. Soil Physical Characteristics and Biological Indicators of Soil Quality Under Different Biodegradable Mulches

    Science.gov (United States)

    Schaeffer, S. M.; Flury, M.; Sintim, H.; Bandopadhyay, S.; Ghimire, S.; Bary, A.; DeBruyn, J.

    2015-12-01

    Application of conventional polyethylene (PE) mulch in crop production offers benefits of increased water use efficiency, weed control, management of certain plant diseases, and maintenance of a micro-climate conducive for plant growth. These factors improve crop yield and quality, but PE must be retrieved and safely disposed of after usage. Substituting PE with biodegradable plastic mulches (BDM) would alleviate disposal needs, and is potentially a more sustainable practice. However, knowledge of potential impacts of BDMs on agricultural soil ecosystems is needed to evaluate sustainability. We (a) monitored soil moisture and temperature dynamics, and (b) assessed soil quality upon usage of different mulches, with pie pumpkin (Cucurbita pepo) as the test crop. Experimental field trials are ongoing at two sites, one at Northwestern Washington Research and Extension Center, Mount Vernon, WA, and the other at East Tennessee Research and Education Center, Knoxville, TN. The treatments constitute four different commercial BDM products, one experimental BDM; no mulch and PE served as the controls. Soil quality parameters being examined include: organic matter content, aggregate stability, water infiltration rate, CO2 flux, pH, and extracellular enzyme activity. In addition, lysimeters were installed to examine the soil water and heat flow dynamics. We present baseline and the first field season results from this study. Mulch cover appeared to moderate soil temperatures, but biodegradable mulches also appeared to lose water more quickly than PE. All mulch types, with the exception of cellulose, reduced the diurnal fluctuations in soil temperature at 10cm depth from 1 to 4ºC. However, volumetric water content ranged from 0.10 to 0.22 m3 m-3 under the five biodegradable mulches compared to 0.22 to 0.28 m3 m-3 under conventional PE. Results from the study will be useful for management practices by providing knowledge on how different mulches impact soil physical and

  15. Study on cultural innovation of Shanghai physical education under international perspective—on the role of physical education teachers

    Directory of Open Access Journals (Sweden)

    WANG Ziqing

    2013-08-01

    Full Text Available Shanghai school sports culture is formed in the process of accumulation and inherited after years of school physical education reform and practice in Shanghai,with Shanghai local characteristics of the physical education culture.Its innovation will help the majority of Shanghai young students to meet their needs of culture and to promote their identity to cultural of Shanghai city to make Shanghai school sports achieve the power of sustainable development.The innovation of Shanghai school sports culture includes the innovation in ideas of school sports,school sports system,contains of school sports activities etc.Shanghai school sports culture innovative ways includes communication with the school′s sports culture,integration,the original innovation.Currently Shanghai school sports culture innovation level is not high, the incentive to innovate is accumulating.Innovation mechanisms is not yet perfect,it is needed to improve the mechanism,to optimize the environment for innovation.Further efforts are paid to stimulate innovation,giving full play to the main role of physical education teachers in order to further enhance the innovation level of Shanghai school sports culture.

  16. Physical attributes of ultisol of Brazil's northeastern semiarid under organic farming of wine grapes

    Directory of Open Access Journals (Sweden)

    Jardenia R. Feitosa

    2015-03-01

    Full Text Available The purpose of this study was to evaluate the effects of organic farming of wine grapes under physical and chemical characteristics of Ultisol Brazil's northeastern semiarid region. The samples of soil were collected from the row and interrow of the farming and from the fallow area, at the depths of 0.0-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.60 m. The samples were collected at six and twelve months after the culture implementation to evaluate the state of aggregation, bulk density and total soil porosity, flocculation index and organic matter contents, calcium, magnesium, and sodium. The results were submitted to statistical analysis. The adoption of organic farming contributed to the soil aggregation process. The bulk density and total soil porosity did not differ significantly between the evaluations, but were within the critical limits for sandy soils. The index flocculation did not have a great influence on the aggregates formation, being this process influenced by organic matter. The period of one year was considered short to obtain conclusive results in improving the soil quality by organic farming, since there are difficulties in tropical soils in promoting significant increases in organic matter content in short time.

  17. Physical attributes of Ultisol of Brazil's northeastern semiarid under organic farming of wine grapes.

    Science.gov (United States)

    Feitosa, Jardenia R; Mendes, Alessandra M S; Olszevski, Nelci; Cunha, Tony J F; Cortez, Jorge W; Giongo, Vanderlise

    2015-03-01

    The purpose of this study was to evaluate the effects of organic farming of wine grapes under physical and chemical characteristics of Ultisol Brazil's northeastern semiarid region. The samples of soil were collected from the row and interrow of the farming and from the fallow area, at the depths of 0.0-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.60 m. The samples were collected at six and twelve months after the culture implementation to evaluate the state of aggregation, bulk density and total soil porosity, flocculation index and organic matter contents, calcium, magnesium, and sodium. The results were submitted to statistical analysis. The adoption of organic farming contributed to the soil aggregation process. The bulk density and total soil porosity did not differ significantly between the evaluations, but were within the critical limits for sandy soils. The index flocculation did not have a great influence on the aggregates formation, being this process influenced by organic matter. The period of one year was considered short to obtain conclusive results in improving the soil quality by organic farming, since there are difficulties in tropical soils in promoting significant increases in organic matter content in short time.

  18. Evaluating the soil physical quality under long-term field experiments in Southern Italy

    Science.gov (United States)

    Castellini, Mirko; Stellacci, Anna Maria; Iovino, Massimo; Rinaldi, Michele; Ventrella, Domenico

    2017-04-01

    Long-term field experiments performed in experimental farms are important research tools to assess the soil physical quality (SPQ) given that relatively stable conditions can be expected in these soils. However, different SPQ indicators may sometimes provide redundant or conflicting results, making difficult an SPQ evaluation (Castellini et al., 2014). As a consequence, it is necessary to apply appropriate statistical procedures to obtain a minimum set of key indicators. The study was carried out at the Experimental Farm of CREA-SCA (Foggia) in two long-term field experiments performed on durum wheat. The first long-term experiment is aiming at evaluating the effects of two residue management systems (burning, B or soil incorporation of crop residues, I) while the second at comparing the effect of tillage (conventional tillage, CT) and sod-seeding (direct drilling, DD). In order to take into account both optimal and non-optimal soil conditions, five SPQ indicators were monitored at 5-6 sampling dates during the crop season (i.e., between November and June): soil bulk density (BD), macroporosity (PMAC), air capacity (AC), plant available water capacity (PAWC) and relative field capacity (RFC). Two additional data sets, collected on DD plot in different cropping seasons and in Sicilian soils differing for texture, depth and land use (N=140), were also used with the aim to check the correlation among indicators. Impact of soil management was assessed by comparing SPQ evaluated under different management systems with optimal reference values reported in literature. Two techniques of multivariate analysis (principal component analysis, PCA and stepwise discriminant analysis, SDA) were applied to select the most suitable indicator to facilitate the judgment on SPQ. Regardless of the considered management system, sampling date or auxiliary data set, correlation matrices always showed significant negative relationships between RFC and AC. Decreasing RFC at increasing AC is

  19. Dynamics of cardiovascular parameters in combined aortic malformations under the influence of a physical therapy program during the rehabilitation process

    Directory of Open Access Journals (Sweden)

    Serhii Kalmykov

    2017-12-01

    Full Text Available Purpose: to study hemodynamic parameters and the reaction of the cardiovascular system to the dosed physical load of patients combined aortic defect with heart failure of the I degree under the influence of the complex physical therapy program developed by us during the rehabilitation process. Material & Methods: the study involved 26 middle-aged men with a diagnosis: combined aortic valve disease, HF I st. Result: dynamics of functional parameters of the cardiovascular system of patients under the influence of the physical therapy program is analyzed. Conclusion: the combination of morning hygienic gymnastics, therapeutic gymnastics, independent activities and dosed walking with a therapeutic massage contributes to the normalization of vascular tone, motor-vascular reflexes and blood pressure, increasing the tolerance of the cardiovascular system to physical activity.

  20. Principles of Lasers

    CERN Document Server

    Svelto, Orazio

    2010-01-01

    This new Fifth Edition of Principles of Lasers incorporates corrections to the previous edition. The text’s essential mission remains the same: to provide a wide-ranging yet unified description of laser behavior, physics, technology, and current applications. Dr. Svelto emphasizes the physical rather than the mathematical aspects of lasers, and presents the subject in the simplest terms compatible with a correct physical understanding. Praise for earlier editions: "Professor Svelto is himself a longtime laser pioneer and his text shows the breadth of his broad acquaintance with all aspects of the field … Anyone mastering the contents of this book will be well prepared to understand advanced treatises and research papers in laser science and technology." (Arthur L. Schawlow, 1981 Nobel Laureate in Physics) "Already well established as a self-contained introduction to the physics and technology of lasers … Professor Svelto’s book, in this lucid translation by David Hanna, can be strongly recommended for...

  1. Principles of musical acoustics

    CERN Document Server

    Hartmann, William M

    2013-01-01

    Principles of Musical Acoustics focuses on the basic principles in the science and technology of music. Musical examples and specific musical instruments demonstrate the principles. The book begins with a study of vibrations and waves, in that order. These topics constitute the basic physical properties of sound, one of two pillars supporting the science of musical acoustics. The second pillar is the human element, the physiological and psychological aspects of acoustical science. The perceptual topics include loudness, pitch, tone color, and localization of sound. With these two pillars in place, it is possible to go in a variety of directions. The book treats in turn, the topics of room acoustics, audio both analog and digital, broadcasting, and speech. It ends with chapters on the traditional musical instruments, organized by family. The mathematical level of this book assumes that the reader is familiar with elementary algebra. Trigonometric functions, logarithms and powers also appear in the book, but co...

  2. Fundamental principles of quantum theory

    International Nuclear Information System (INIS)

    Bugajski, S.

    1980-01-01

    After introducing general versions of three fundamental quantum postulates - the superposition principle, the uncertainty principle and the complementarity principle - the question of whether the three principles are sufficiently strong to restrict the general Mackey description of quantum systems to the standard Hilbert-space quantum theory is discussed. An example which shows that the answer must be negative is constructed. An abstract version of the projection postulate is introduced and it is demonstrated that it could serve as the missing physical link between the general Mackey description and the standard quantum theory. (author)

  3. Thermodynamic properties of ideal Fermi gases in a harmonic potential in an n-dimensional space under the generalized uncertainty principle

    Science.gov (United States)

    Li, Heling; Ren, Jinxiu; Wang, Wenwei; Yang, Bin; Shen, Hongjun

    2018-02-01

    Using the semi-classical (Thomas-Fermi) approximation, the thermodynamic properties of ideal Fermi gases in a harmonic potential in an n-dimensional space are studied under the generalized uncertainty principle (GUP). The mean particle number, internal energy, heat capacity and other thermodynamic variables of the Fermi system are calculated analytically. Then, analytical expressions of the mean particle number, internal energy, heat capacity, chemical potential, Fermi energy, ground state energy and amendments of the GUP are obtained at low temperatures. The influence of both the GUP and the harmonic potential on the thermodynamic properties of a copper-electron gas and other systems with higher electron densities are studied numerically at low temperatures. We find: (1) When the GUP is considered, the influence of the harmonic potential is very much larger, and the amendments produced by the GUP increase by eight to nine orders of magnitude compared to when no external potential is applied to the electron gas. (2) The larger the particle density, or the smaller the particle masses, the bigger the influence of the GUP. (3) The effect of the GUP increases with the increase in the spatial dimensions. (4) The amendments of the chemical potential, Fermi energy and ground state energy increase with an increase in temperature, while the heat capacity decreases. T F0 is the Fermi temperature of the ideal Fermi system in a harmonic potential. When the temperature is lower than a certain value (0.22 times T F0 for the copper-electron gas, and this value decreases with increasing electron density), the amendment to the internal energy is positive, however, the amendment decreases with increasing temperature. When the temperature increases to the value, the amendment is zero, and when the temperature is higher than the value, the amendment to the internal energy is negative and the absolute value of the amendment increases with increasing temperature. (5) When electron

  4. Chemical and physical fractions of soil organic matter under various management regimes in Roraima, Brazil

    Directory of Open Access Journals (Sweden)

    Marden Daniel Espinoza Guardiola

    2017-08-01

    Full Text Available The crop-livestock integration (CLI and crop-livestock-forest integration (CLFI management systems, have been shown to be viable approaches for increasing carbon sequestration in soils, resulting in the improvement of physical and chemical soil attributes. The objective of this study was to evaluate the chemical attributes and organic matter in soils under Natural Forest (NF converted to different uses and managed differently: rotational pasture area (PAST, crop-livestock integration (CLI, and crop-livestock-forest integration (CLIF. The research was conducted at the São Paulo farm, in Iracema, located in the south-central region of the state of Roraima, Brazil. The studied soil type was classified as Ultisol. Soil samples were taken by opening ditches and examining layers at 0.1-m depth intervals from surface to 0.60-m depth. Total organic carbon (TOC, chemical and granulometric fractionation of soil organic matter (SOM, oxidizable fractions, and light organic matter in water were analyzed. Our results showed low levels of the analyzed chemical elements, a characteristic of a soil with low natural fertility. This matches conditions inherent in source material, weathered by high rainfall, a warm and humid climate, and flat topographic relief. In the 0-0.1 m layer, the PAST and CLI systems had the highest TOC contents relative to the other systems studied. At other depths, there were no statistical differences among TOC levels. The highest concentration of C in the particulate fraction (POC was noted in the surface layer in all management systems. The pasture system had the highest concentration POC in the top 0.10 m. Our results also showed that the upper 0.10 m of soil in NF contained the lowest content of organic carbon associated with mineral (MOC relative to the managed agrosystems. In addition, humin provided the largest contribution to SOM in all evaluated management systems. The crop-livestock integration (CLI and crop

  5. Physics based Degradation Modeling and Prognostics of Electrolytic Capacitors under Electrical Overstress Conditions

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper proposes a physics based degradation modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors are critical components in...

  6. VARIATIONAL PRINCIPLE FOR PLANETARY INTERIORS

    International Nuclear Information System (INIS)

    Zeng, Li; Jacobsen, Stein B.

    2016-01-01

    In the past few years, the number of confirmed planets has grown above 2000. It is clear that they represent a diversity of structures not seen in our own solar system. In addition to very detailed interior modeling, it is valuable to have a simple analytical framework for describing planetary structures. The variational principle is a fundamental principle in physics, entailing that a physical system follows the trajectory, which minimizes its action. It is alternative to the differential equation formulation of a physical system. Applying the variational principle to the planetary interior can beautifully summarize the set of differential equations into one, which provides us some insight into the problem. From this principle, a universal mass–radius relation, an estimate of the error propagation from the equation of state to the mass–radius relation, and a form of the virial theorem applicable to planetary interiors are derived.

  7. 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...

  8. Underlying Dimensions of the "Physical Educators' Judgments about Inclusion" Instrument: Brazilian-Version

    Science.gov (United States)

    Hodge, Samuel R.; Gutierres Filho, Paulo José Barbosa; Haegele, Justin A.; Kozub, Francis M.

    2015-01-01

    Background/Objective: The available information pertaining to the attitudes of Brazilian physical education teachers about teaching students with disabilities is limited in the extant literature base. Rationally, however, scholars argue that determining, analyzing, and theorizing about the attitudes of physical education teachers is important in…

  9. Zymography Principles.

    Science.gov (United States)

    Wilkesman, Jeff; Kurz, Liliana

    2017-01-01

    Zymography, the detection, identification, and even quantification of enzyme activity fractionated by gel electrophoresis, has received increasing attention in the last years, as revealed by the number of articles published. A number of enzymes are routinely detected by zymography, especially with clinical interest. This introductory chapter reviews the major principles behind zymography. New advances of this method are basically focused towards two-dimensional zymography and transfer zymography as will be explained in the rest of the chapters. Some general considerations when performing the experiments are outlined as well as the major troubleshooting and safety issues necessary for correct development of the electrophoresis.

  10. Physical, chemical, and biological properties of soil under soybean cultivation and at an adjacent rainforest in Amazonia

    Science.gov (United States)

    T.P. Beldini; R.C. Oliveira Junior; Michael Keller; P.B. de Camargo; P.M. Crill; A. Damasceno da Silva; D. Bentes dos Santos; D. Rocha de Oliveira

    2015-01-01

    Land-use change in the Amazon basin has occurred at an accelerated pace during the last decade, and it is important that the effects induced by these changes on soil properties are better understood. This study investigated the chemical, physical, and biological properties of soil in a field under cultivation of soy and rice, and at an adjacent primary rain forest....

  11. Proximity under Threat: The Role of Physical Distance in Intergroup Relations

    Science.gov (United States)

    Wohl, Michael J. A.; Van Bavel, Jay J.

    2016-01-01

    Throughout human history, social groups have invested immense amounts of wealth and time to keep threatening out-groups at a distance. In the current research, we explored the relationship between intergroup threat, physical distance, and discrimination. Specifically, we examined how intergroup threat alters estimates of physical distance to out-groups and how physical proximity affects intergroup relations. Previous research has found that people judge threatening out-groups as physically close. In Studies 1 and 2, we examined ways to attenuate this bias. In Study 1 a secure (vs. permeable) US-Mexico border reduced the estimated proximity to Mexico City among Americans who felt threatened by Mexican immigration. In Study 2, intergroup apologies reduced estimates of physical proximity to a threatening cross-town rival university, but only among participants with cross-group friendships. In Study 3, New York Yankees fans who received an experimental induction of physical proximity to a threatening out-group (Boston Red Sox) had a stronger relationship between their collective identification with the New York Yankees and support for discriminatory policies toward members of the out-group (Red Sox fans) as well as how far they chose to sit from out-group members (Red Sox fans). Together, these studies suggest that intergroup threat alters judgment of physical properties, which has important implications for intergroup relations. PMID:27467267

  12. Thermionics basic principles of electronics

    CERN Document Server

    Jenkins, J; Ashhurst, W

    2013-01-01

    Basic Principles of Electronics, Volume I : Thermionics serves as a textbook for students in physics. It focuses on thermionic devices. The book covers topics on electron dynamics, electron emission, and the themionic vacuum diode and triode. Power amplifiers, oscillators, and electronic measuring equipment are studied as well. The text will be of great use to physics and electronics students, and inventors.

  13. 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 ...

  14. The principle of least action

    CERN Document Server

    Rojo, Alberto

    2018-01-01

    The principle of least action originates in the idea that, if nature has a purpose, it should follow a minimum or critical path. This simple principle, and its variants and generalizations, applies to optics, mechanics, electromagnetism, relativity, and quantum mechanics, and provides an essential guide to understanding the beauty of physics. This unique text provides an accessible introduction to the action principle across these various fields of physics, and examines its history and fundamental role in science. It includes - with varying levels of mathematical sophistication - explanations from historical sources, discussion of classic papers, and original worked examples. The result is a story that is understandable to those with a modest mathematical background, as well as to researchers and students in physics and the history of physics.

  15. Gamescape Principles

    DEFF Research Database (Denmark)

    Nobaew, Banphot; Ryberg, Thomas

    2011-01-01

    developed by Buckingham. It supplements and extends this framework by offering a more detailed account of how visual principles and elements in games can be analysed. In developing this visual grammar we draw theoretically on existing approaches within: the arts, history, film study, semiotics, multimodal...... analysis, and game studies. We illustrate the theoretical and analytical framework by analysing samples of screenshots and video clips collected from the online game “World of Warcraft” (WoW) where we have conducted our online research. The research data is supplemented by ethnographic data (observation......This paper proposes a new theoretical framework or visual grammar for analysing visual aspects of digital 3D games, and for understanding more deeply the notion of Visual Digital Game Literacy. The framework focuses on the development of a visual grammar by drawing on the digital literacy framework...

  16. 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...

  17. 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...

  18. The physics of bat echolocation: Signal processing techniques

    Science.gov (United States)

    Denny, Mark

    2004-12-01

    The physical principles and signal processing techniques underlying bat echolocation are investigated. It is shown, by calculation and simulation, how the measured echolocation performance of bats can be achieved.

  19. Heisenberg's principles

    CERN Multimedia

    1971-01-01

    Remote from the noise and bustle of Europe's capital cities, in the charming German lake-side town of Lindau, close to the borders of Austria and Switzerland, Nobel Prize Winners in physics gathered together from June 28-July 2 to talk of their science and its interaction with society.

  20. Development of Physical Protection Regulations for Rosatom State Corporation Sites under the U.S.-Russian MPC&A Program

    Energy Technology Data Exchange (ETDEWEB)

    Izmaylov, Alexander; Babkin, Vladimir; Shemigon, Nikolai N.; O' Brien, Patricia; Wright, Troy L.; Hazel, Michael J.; Tuttle, John D.; Cunningham, Mitchel E.; Lane, Melinda; Kovchegin, Dmitry

    2012-07-14

    This paper describes issues related to upgrading the physical protection regulatory basis for Rosatom State Corporation sites. It is underlined that most of the regulatory and methodological documents for this subject area have been developed under the U.S.-Russian MPC&A Program. According to the joint management plan developed and agreed upon by the parties in 2005, nearly 50 physical protection documents were identified to be developed, approved and implemented at Rosatom sites by 2012. It is also noted that, on the whole, the plans have been fulfilled.

  1. Applicability of DLVO Approach to Predict Trends in Iron Oxide Colloid Mobility Under Various Physical And Chemical Soil Conditions

    Science.gov (United States)

    Florian Carstens, Jannis; Bachmann, Jörg; Neuweiler, Insa

    2014-05-01

    In soil and groundwater, highly mobile iron oxide colloids can act as "shuttles" for transport of adsorbed contaminants such as heavy metals and radionuclides. Artificial iron oxide colloids are injected into polluted porous media to accelerate bacterial degradation of pollutants in the context of bioremediation purposes. The mobility of iron oxide colloids is strongly affected by the hydraulic, physical and chemical conditions of the pore space, the solid particle surface properties, the fluid phase, and the colloids themselves. Most pioneering studies focused on iron oxide colloid transport and retention in simplified model systems. The aim of this study is to investigate iron oxide colloid mobility under more complex, soil-typical conditions that have as yet only been applied for model microspheres, i.e. functionalized latex colloids. Among these conditions is the pivotal impact of organic matter, either dissolved or adsorbed onto solid particles, modifying wettability properties. Of particular importance was to determine if effective chemical surface parameters derived from contact angle and zeta potential measurements can be used as a tool to predict general tendencies for iron oxide colloid mobility in porous media. In column breakthrough experiments, goethite colloids (particle size: 200-900 nm) were percolated through quartz sand (grain size: 100-300 µm) at pH 5. The impact of a multitude of conditions on colloid mobility was determined: dissolved organic matter (DOM) concentration, ionic strength, flow velocity, flow interruption, partial saturation, and drying with subsequent re-wetting. The solid matrix consisted of either clean sand, organic matter-coated sand, goethite-coated sand, or sand hydrophobized with dichlorodimethylsilane. Additionally, contact angles and zeta potentials of the materials applied in the column experiments were measured. By means of these surface parameters, traditional DLVO interaction energies based on zeta potential as well

  2. PHYSICS

    CERN Document Server

    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. Diffusion behaviors of fluorescence probe molecules through the stratum corneum layer under physical stress.

    Science.gov (United States)

    Lee, Ho; Kim, Jin Woong

    2013-04-01

    This study experimentally demonstrates how application of an external physical stress onto the skin membrane affects the permeation of penetrating molecules. As a proxy of active compounds, in this study, a series of fluorescence probe molecules were utilized. We observed that skin permeation could be enhanced by imparting vertical strokes from a tapping head consisting of projections onto the skin. This was confirmed with consistency from in vitro and in vivo transdermal permeation studies. After an effective physical stress was applied to the skin, the permeation depth of probe molecules remarkably increased, which was comparable to the case of topical treatment. This seems to arise from temporal disordering of the stratum corneum layer in response to the applied physical stress.

  4. How inflammation underlies physical and organ function in acutely admitted older medical patients

    DEFF Research Database (Denmark)

    Klausen, Henrik Hedegaard; Bodilsen, Ann Christine; Petersen, Janne

    2017-01-01

    OBJECTIVES: To investigate whether systemic inflammation in acutely admitted older medical patients (age >65 years) is associated with physical performance and organ dysfunction. Organ dysfunction´s association with physical performance, and whether these associations are mediated by systemic...... inflammation, was also investigated. METHODS: A cross-sectional study in an Emergency Department. Physical performance was assessed by handgrip strength and de Morton Mobility Index (DEMMI), and organ dysfunction by FI-OutRef, the number of standard blood tests outside the reference range. Systemic...... inflammation was assessed by suPAR, TNFα, and IL-6. Associations were investigated by regression analyses adjusted for age, sex, cognitive impairment, CRP, and VitalPAC Modified Early Warning Score. RESULTS: A total of 369 patients were evaluated. In adjusted analyses, suPAR and TNFα was associated with both...

  5. Resilience Evaluation of Demand Response as Spinning Reserve under Cyber-Physical Threats

    Directory of Open Access Journals (Sweden)

    Anas AlMajali

    2016-12-01

    Full Text Available In the future, automated demand response mechanisms will be used as spinning reserve. Demand response in the smart grid must be resilient to cyber-physical threats. In this paper, we evaluate the resilience of demand response when used as spinning reserve in the presence of cyber-physical threats. We quantify this evaluation by correlating the stability of the system in the presence of attacks measured by system frequency (Hz and attack level measured by the amount of load (MW that responds to the demand response event. The results demonstrate the importance of anticipating the dependability of demand response before it can be relied upon as spinning reserve.

  6. The Generalized Principle of the Golden Section and its applications in mathematics, science, and engineering

    International Nuclear Information System (INIS)

    Stakhov, A.P.

    2005-01-01

    The 'Dichotomy Principle' and the classical 'Golden Section Principle' are two of the most important principles of Nature, Science and also Art. The Generalized Principle of the Golden Section that follows from studying the diagonal sums of the Pascal triangle is a sweeping generalization of these important principles. This underlies the foundation of 'Harmony Mathematics', a new proposed mathematical direction. Harmony Mathematics includes a number of new mathematical theories: an algorithmic measurement theory, a new number theory, a new theory of hyperbolic functions based on Fibonacci and Lucas numbers, and a theory of the Fibonacci and 'Golden' matrices. These mathematical theories are the source of many new ideas in mathematics, philosophy, botanic and biology, electrical and computer science and engineering, communication systems, mathematical education as well as theoretical physics and physics of high energy particles

  7. Quantum principles in field interactions

    International Nuclear Information System (INIS)

    Shirkov, D.V.

    1986-01-01

    The concept of quantum principle is intruduced as a principle whosee formulation is based on specific quantum ideas and notions. We consider three such principles, viz. those of quantizability, local gauge symmetry, and supersymmetry, and their role in the development of the quantum field theory (QFT). Concerning the first of these, we analyze the formal aspects and physical contents of the renormalization procedure in QFT and its relation to ultraviolet divergences and the renorm group. The quantizability principle is formulated as an existence condition of a self-consistent quantum version with a given mechanism of the field interaction. It is shown that the consecutive (from a historial point of view) use of these quantum principles puts still larger limitations on possible forms of field interactions

  8. A Development of the Principle of Virtual Laws and its Conceptual Framework in Mechanics as Fundamental Relationship between Physics and Mathematics

    Directory of Open Access Journals (Sweden)

    Raffaele Pisano

    2017-06-01

    Full Text Available Generally speaking, virtual displacement or work concerns to a timely idea according to which a motion of a certain body is not the unique possible motion. The process of reducing this motion to a particular magnitude and concept, eventually minimizing as a hypothesis, can be traced back to the Aristotelian school. In the history and philosophy of science one finds various enunciations of the Principle of Virtual Laws and its virtual displacement or work applications, i.e., from Aristotle to Leibniz’s vis viva, from Maupertuis’ least action to Euler and Lagrange with calculus of variations (statics and dynamics to Lazare Carnot’s mechanics. In this case study, I will demonstrate that a particular approach used by Lazare Carnot is original by explaining within the historical context of rival approaches such as the development of the Principle of virtual Laws (also known as the Principle of virtual velocity or of virtual work. I will also discuss Carnot’s geometric motion as one of the possible but invertible movements applied to virtual displacement as employed in his theories of machines and collisions. I will then go on to explore how the originality of an invertible motion within his mechanical and, in general, mathematical research program permitted Carnot to introduce a new way of structuring a scientific theory and making mechanics, with respect to the Newtonian paradigm, to scholars and his students of the École polytechnique de Paris.

  9. Sensitivity analyses of biodiesel thermo-physical properties under diesel engine conditions

    DEFF Research Database (Denmark)

    Cheng, Xinwei; Ng, Hoon Kiat; Gan, Suyin

    2016-01-01

    This reported work investigates the sensitivities of spray and soot developments to the change of thermo-physical properties for coconut and soybean methyl esters, using two-dimensional computational fluid dynamics fuel spray modelling. The choice of test fuels made was due to their contrasting s...

  10. Principles of mobile communication

    CERN Document Server

    Stüber, Gordon L

    2017-01-01

    This mathematically rigorous overview of physical layer wireless communications is now in a 4th, fully revised and updated edition. The new edition features new content on 4G cellular systems, 5G cellular outlook, bandpass signals and systems, and polarization, among many other topics, in addition to a new chapters on channel assignment techniques. Along with coverage of fundamentals and basic principles sufficient for novice students, the volume includes finer details that satisfy the requirements of graduate students aiming to conduct in-depth research. The book begins with a survey of the field, introducing issues relevant to wireless communications. The book moves on to cover relevant discrete subjects, from radio propagation, to error probability performance, and cellular radio resource management. An appendix provides a tutorial on probability and random processes. The content stresses core principles that are applicable to a broad range of wireless standards. New examples are provided throughout the bo...

  11. Principles of photonics

    CERN Document Server

    Liu, Jia-Ming

    2016-01-01

    With this self-contained and comprehensive text, students will gain a detailed understanding of the fundamental concepts and major principles of photonics. Assuming only a basic background in optics, readers are guided through key topics such as the nature of optical fields, the properties of optical materials, and the principles of major photonic functions regarding the generation, propagation, coupling, interference, amplification, modulation, and detection of optical waves or signals. Numerous examples and problems are provided throughout to enhance understanding, and a solutions manual containing detailed solutions and explanations is available online for instructors. This is the ideal resource for electrical engineering and physics undergraduates taking introductory, single-semester or single-quarter courses in photonics, providing them with the knowledge and skills needed to progress to more advanced courses on photonic devices, systems and applications.

  12. Principles of Mobile Communication

    CERN Document Server

    Stüber, Gordon L

    2012-01-01

    This mathematically rigorous overview of physical layer wireless communications is now in a third, fully revised and updated edition. Along with coverage of basic principles sufficient for novice students, the volume includes plenty of finer details that will satisfy the requirements of graduate students aiming to research the topic in depth. It also has a role as a handy reference for wireless engineers. The content stresses core principles that are applicable to a broad range of wireless standards. Beginning with a survey of the field that introduces an array of issues relevant to wireless communications and which traces the historical development of today’s accepted wireless standards, the book moves on to cover all the relevant discrete subjects, from radio propagation to error probability performance and cellular radio resource management. A valuable appendix provides a succinct and focused tutorial on probability and random processes, concepts widely used throughout the book. This new edition, revised...

  13. Do adults with Down syndrome do the same amount of physical activity as adults without disability? A proof of principle study.

    Science.gov (United States)

    Shields, Nora; Plant, Samantha; Warren, Catherine; Wollersheim, Dennis; Peiris, Casey

    2017-09-27

    This study compared levels of physical activity completed by adults with and without Down syndrome. Fifteen adults with and 15 adults without Down syndrome matched for age and gender, took part. The intensity and duration of physical activity were measured using RT3 accelerometers worn for seven days. Only, 12 participants with Down syndrome had complete physical activity data, and these participants and their matched controls (total: six females, 18 males; aged 25.8 ± 9.7) were included in the analyses. There were significantly lower levels of moderate and vigorous physical activity per day for people with Down syndrome (median = 27 min) compared to those without (median = 101 min) (p Down syndrome. Adults with Down syndrome appear to participate in lower levels of physical activity than adults without Down syndrome. Further research should validate these estimates. © 2017 John Wiley & Sons Ltd.

  14. The Leibniz principle in quantum logic

    Energy Technology Data Exchange (ETDEWEB)

    Giuntini, R.; Mittelstaedt, P. (Univ. of Cologne (West Germany))

    1989-02-01

    The principle of the identity of indiscernibles (Leibniz Principle) is investigated within the framework of the formal language of quantum physics, which is given by an orthomodular lattice. The authors show that the validity of this principle is based on very strong preconditions (concerning the existence of convenient predicates) which are given in the language of classical physics but which cannot be fulfilled in orthomodular quantum logic.

  15. Physical, Chemical, and Biological Properties of Soil under Decaying Wood in a Tropical Wet Forest in Puerto Rico

    Science.gov (United States)

    Marcela Zalamea; Grizelle Gonzalez; D. Jean Lodge

    2016-01-01

    Decaying wood is related to nutrient cycling through its role as either a sink or source of nutrients. However, at micro scales, what is the effect of decaying logs on the physical, chemical,and biotic characteristics of the soil underneath? We took samples from a 0 to 5 cm depth under and a 50 cm distance away from decaying logs (Dacryodes excelsa and Swietenia...

  16. 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...

  17. 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...

  18. Distinct effects of reminding mortality and physical pain on the default-mode activity and activity underlying self-reflection.

    Science.gov (United States)

    Shi, Zhenhao; Han, Shihui

    2018-06-01

    Behavioral research suggests that reminding both mortality and negative affect influences self-related thoughts. Using functional magnetic resonance imaging (MRI), we tested the hypothesis that reminders of mortality and physical pain decrease brain activity underlying self-related thoughts. Three groups of adults underwent priming procedures during which they answered questions pertaining to mortality, physical pain, or leisure time, respectively. Before and after priming, participants performed personality trait judgments on oneself or a celebrity, identified the font of words, or passively viewed a fixation. The default-mode activity and neural activity underlying self-reflection were identified by contrasting viewing a fixation vs. font judgment and trait judgments on oneself vs. a celebrity, respectively. The analyses of the pre-priming functional MRI (fMRI) data identified the default-mode activity in the posterior cingulate cortex (PCC), ventral medial prefrontal cortex (MPFC), and parahippocampal gyrus, and the activity underlying instructed self-reflection in both the ventral and dorsal regions of the MPFC. The analyses of the post-priming fMRI data revealed that, relative to leisure time priming, reminding mortality significantly reduced the default-mode PCC activity, and reminding physical pain significantly decreased the dorsal MPFC activity during instructed self-reflection. Our findings suggest distinct neural underpinnings of the effect of reminding morality and aversive emotion on default-mode and instructed self-reflection.

  19. Laboratory Experiments to Simulate and Investigate the Physics Underlying the Dynamics of Merging Solar Corona Structures

    Science.gov (United States)

    2016-06-05

    described analytic Grad-Shafranov toroidal equilibria where the pressure on the magnetic axis is lower than the pres- sure external to the toroid so...2015. Magnetic axis safety factor of finite beta spheromaks and transition from spheromaks to toroidal magnetic bubbles. Physics of Plasmas, 22(2...Paccagnella, Roberto. 2015. Magnetic axis safety factor of finite beta spheromaks and transition from spheromaks to toroidal magnetic bubbles

  20. A large data base on a small computer. Neutron Physics data and bibliography under IDMS

    International Nuclear Information System (INIS)

    Schofield, A.; Pellegrino, L.; Tubbs, N.

    1978-01-01

    The transfer of three associated files to an IDMS data base is reported: the CINDA bibliographic index to neutron physics publications, the cumulated EXFOR exchange tapes used for maintaining parallel data collections at all four centres and the CCDN's internal data storage and retrieval system NEUDADA. With associated dictionaries and inter-file conversion tables the corresponding IDMS data base will be about 160 Mbytes. The main characteristics of the three files are shown

  1. Soil physical properties under different soil managements for the cultivation of sweet potato

    Directory of Open Access Journals (Sweden)

    Amarílis Beraldo Rós

    2014-02-01

    Full Text Available This study aimed to assess the impact of tillage systems on physical properties of an Alfissol type soil and on the growth of sweet potato tuberous roots. To assess the soil physical properties, an experiment was conducted in randomized blocks design, in split-plot scheme. The plots consisted of the treatments conventional tillage with making mounds and straw incorporated, conventional tillage with making mounds and without straw, reduced tillage with straw on the soil surface and reduced tillage without straw; and the subplots, to collect periods. The soil physical properties evaluated were soil bulk density, total soil porosity, soil macroporosity and soil microporosity, soil resistance to penetration and gravimetric soil water. For the assessment of the growth of sweet potato tuberous roots, it was adopted an experiment where the plots corresponded to the soil management forms and subplots to four collect periods: 90, 120, 150 and 180 (DAP. The length / roots diameter of individual roots relations were avaluated. It was concluded that the reduced tillage gives greater soil resistance to penetration of roots, by reducing the vertical growth of roots, and the presence of straw incorporated in the conventional tillage favors maintenance of lowest soil bulk density and highest soil macroporosity along the time.

  2. 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...

  3. 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...

  4. Principles of quantum chemistry

    CERN Document Server

    George, David V

    2013-01-01

    Principles of Quantum Chemistry focuses on the application of quantum mechanics in physical models and experiments of chemical systems.This book describes chemical bonding and its two specific problems - bonding in complexes and in conjugated organic molecules. The very basic theory of spectroscopy is also considered. Other topics include the early development of quantum theory; particle-in-a-box; general formulation of the theory of quantum mechanics; and treatment of angular momentum in quantum mechanics. The examples of solutions of Schroedinger equations; approximation methods in quantum c

  5. 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.

  6. Effects of four-month handbike training under free-living conditions on physical fitness and health in wheelchair users.

    Science.gov (United States)

    Hoekstra, Sven; Valent, Linda; Gobets, David; van der Woude, Lucas; de Groot, Sonja

    2017-08-01

    Recognizing the encouraging effect of challenging events, the HandbikeBattle (HBB) was created to promote exercise among wheelchair users. The purpose of this study was to reveal the effects on physical fitness and health outcomes of four-month handbike training under free-living conditions in preparation for the event. In this prospective cohort study, 59 relatively inexperienced handyclists participated in the HBB of 2013 or 2014. Incremental exercise tests were conducted, respiratory function was tested and anthropometrics were measured before and after the preparation period. Main outcome measures were peak power output (POpeak), peak oxygen uptake (VO2peak) and waist circumference, of which the changes were tested using repeated measures ANOVA. To detect possible determinants of changes in physical fitness, a linear regression analysis was conducted with personal characteristics, executed training volume and upper-extremity complaints during the training period as independent variables. POpeak, VO2peak and waist circumference improved significantly with 17%, 7% and 4.1%, respectively. None of the included variables were significant determinants for the changes in POpeak found as a result of the training. A challenging event such as the HBB provokes training regimes among participants of sufficient load to realize substantial improvements in physical fitness and health outcomes. Implications for Rehabilitation Due to the often impaired muscle function in the lower-limbs and an inactive lifestyle, wheelchair users generally show considerably lower levels of fitness compared to able-bodied individuals. This prospective cohort study showed that four months of handbike training under free-living conditions in preparation for this event resulted in substantial improvements in physical fitness and health outcomes in wheelchair users. The creation of a challenging event such as the HandbikeBattle as part of a follow-up rehabilitation practice can therefore be a useful

  7. Restorability on 3-connected WDM Networks Under Single and Dual Physical Link Failures

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Jensen, Michael; Riaz, Tahir

    2013-01-01

    This work studies the influence the network interconnection has over restoration techniques. The way physical links are distributed to interconnect network nodes has a great impact on parameters such as path distances when failures occur and restoration is applied. The work focuses on single and ...... to network planning, the trade-off network length vs. performance of the different topological options is studied. The results show how 3-connected graphs could provide a reasonable trade-off between costs, link failure rates, and restored path parameters....

  8. Under the spell of Landau when theoretical physics was shaping destinies

    CERN Document Server

    2013-01-01

    This invaluable collection of memoirs and reviews on scientific activities of the most prominent theoretical physicists belonging to the Landau School - Landau, Anselm, Gribov, Zeldovich, Kirzhnits, Migdal, Ter-Martirosyan and Larkin - are being published in English for the first time. The main goal is to acquaint readers with the life and work of outstanding Soviet physicists who, to a large extent, shaped theoretical physics in the 1950s - 70s. Many intriguing details have remained unknown beyond the "Iron Curtain" which was dismantled only with the fall of the USSR.

  9. Analysis of Physics Processes in the AC Plasma Torch Discharge under High Pressure

    International Nuclear Information System (INIS)

    Safronov, A A; Vasilieva, O B; Dudnik, J D; Kuznetsov, V E; Kuchina, J A; Shiryaev, V N; Pavlov, A V

    2017-01-01

    The paper is devoted to investigation of electrophysical processes in the electric discharge generated by a three-phase AC plasma torch when using a high pressure inert working gas. AC plasma torch design with end electrodes intended for work on inert gases at pressures up to 81 bar is studied. Current-voltage characteristics for different gas flow rates and pressures are presented. Physical processes characteristics of the arising voltage ripples which depend on various working parameters of the plasma torch have been investigated. Arc burning processes in the electric discharge chamber of the three-phase AC plasma torch at various working parameters were photographed. (paper)

  10. Expanding Uncertainty Principle to Certainty-Uncertainty Principles with Neutrosophy and Quad-stage Method

    Directory of Open Access Journals (Sweden)

    Fu Yuhua

    2015-03-01

    Full Text Available The most famous contribution of Heisenberg is uncertainty principle. But the original uncertainty principle is improper. Considering all the possible situations (including the case that people can create laws and applying Neutrosophy and Quad-stage Method, this paper presents "certainty-uncertainty principles" with general form and variable dimension fractal form. According to the classification of Neutrosophy, "certainty-uncertainty principles" can be divided into three principles in different conditions: "certainty principle", namely a particle’s position and momentum can be known simultaneously; "uncertainty principle", namely a particle’s position and momentum cannot be known simultaneously; and neutral (fuzzy "indeterminacy principle", namely whether or not a particle’s position and momentum can be known simultaneously is undetermined. The special cases of "certain ty-uncertainty principles" include the original uncertainty principle and Ozawa inequality. In addition, in accordance with the original uncertainty principle, discussing high-speed particle’s speed and track with Newton mechanics is unreasonable; but according to "certaintyuncertainty principles", Newton mechanics can be used to discuss the problem of gravitational defection of a photon orbit around the Sun (it gives the same result of deflection angle as given by general relativity. Finally, for the reason that in physics the principles, laws and the like that are regardless of the principle (law of conservation of energy may be invalid; therefore "certaintyuncertainty principles" should be restricted (or constrained by principle (law of conservation of energy, and thus it can satisfy the principle (law of conservation of energy.

  11. Physical-chemical and microbiological changes in Cerrado Soil under differing sugarcane harvest management systems

    NARCIS (Netherlands)

    Rachid, Caio T. C. C.; Piccolo, Marisa C.; Leite, Deborah Catharine A.; Balieiro, Fabiano C.; Coutinho, Heitor Luiz C.; van Elsas, Jan Dirk; Peixoto, Raquel S.; Rosado, Alexandre S.

    2012-01-01

    Background: Sugarcane cultivation plays an important role in Brazilian economy, and it is expanding fast, mainly due to the increasing demand for ethanol production. In order to understand the impact of sugarcane cultivation and management, we studied sugarcane under different management regimes

  12. Heavy physical work under time pressure: the garbage collection service--a case study.

    Science.gov (United States)

    Camada, Ilza Mitsuko de Oliveira; Pataro, Silvana Maria Santos; Fernandes, Rita de Cássia Pereira

    2012-01-01

    The increased generation of garbage has become a problem in large cities, with greater demand for collection services. The collector is subjected to high workload. This study describes the work in garbage collection service, highlighting the requirements of time, resulting in physical and psychosocial demands to collectors. Ergonomic Work Analysis (EWA) - a method focused on the study of work in real situations was used. Initially, technical visits, global observations and unstructured interviews with different subjects of a garbage collection company were conducted. The following step of the systematic observations was accompanied by interviews conducted during the execution of tasks, inquiring about the actions taken, and also interviews about the actions, but conducted after the development of the tasks, photographic records and audiovisual recordings, of workers from two garbage collection teams. Contradictions between the prescribed work and activities (actual work) were identified, as well as the variability present in this process, and strategies adopted by these workers to regulate the workload. It was concluded that the insufficiency of means and the organizational structure of management ensue a situation where the collection process is maintained at the expense of hyper-requesting these workers, both physically and psychosocially.

  13. Physical characteristics of potato flour from 'Ibituaçú' cv. under different extrusion parameters

    Directory of Open Access Journals (Sweden)

    Raema Fortes Vicente Cardoso

    2015-12-01

    Full Text Available ABSTRACT: This study aimed to evaluate potato flour from 'Ibituaçú' cultivar as raw material for extrudates. Potato flour was processed in a single-screw extruder following central composite rotational design for three factors, being considered as independent parameters: temperature in the third zone, humidity and screw speed. The products obtained were characterized by expansion index (EI, specific volume (SV, water solubility index (WSI, water absorption index (WAI, hardness (H, color (L*, a* and b*. Results showed an effect of the independent parameters on the extruded physical characteristics. The parameters varied from: 3.22 to 5.47 (EI; 2.08 to 11.23 mL g-1 (SV, 32.88 to 63.72% (WSI, 4.02 to 8.97 g gel g-1 (WAI, 7.54 to 29.85 kgf (H, 53.89 to 68.72 (L*, 5.59 to 6.92 (a*, 16.6 to 22.6 (b*. It was concluded that expanded products with desired physical characteristics are obtained at high temperature; low humidity and intermediate screw speed.

  14. IBPRO - A Novel Short-Duration Teaching Course in Advanced Physics and Biology Underlying Cancer Radiotherapy.

    Science.gov (United States)

    Joiner, Michael C; Tracey, Monica W; Kacin, Sara E; Burmeister, Jay W

    2017-06-01

    This article provides a summary and status report of the ongoing advanced education program IBPRO - Integrated course in Biology and Physics of Radiation Oncology. IBPRO is a five-year program funded by NCI. It addresses the recognized deficiency in the number of mentors available who have the required knowledge and skill to provide the teaching and training that is required for future radiation oncologists and researchers in radiation sciences. Each year, IBPRO brings together 50 attendees typically at assistant professor level and upwards, who are already qualified/certified radiation oncologists, medical physicists or biologists. These attendees receive keynote lectures and activities based on active learning strategies, merging together the clinical, biological and physics underpinnings of radiation oncology, at the forefront of the field. This experience is aimed at increasing collaborations, raising the level and amount of basic and applied research undertaken in radiation oncology, and enabling attendees to confidently become involved in the future teaching and training of researchers and radiation oncologists.

  15. Physical and mechanical properties of gelatin-CMC composite films under the influence of electrostatic interactions.

    Science.gov (United States)

    Esteghlal, Sara; Niakousari, Mehrdad; Hosseini, Seyed Mohammad Hashem

    2018-03-17

    The objective of current study was to examine the electrostatic interactions between gelatin and carboxymethyl cellulose (CMC) as a function of pH and mixing ratio (MR) and to observe how the physical and mechanical properties of gelatin-CMC composite films are affected by these interactions. The interaction between biopolymers was studied using turbidometric analysis at different gelatin: CMC MRs and pH values. A reduction in pH and MR enhanced the electrostatic interactions; while, decreased the relative viscosity of mixed system. Physical and mechanical properties of resultant composite films were examined and compared with those of control gelatin films. Changes in the intensity of interactions between the two biopolymers resulted in films with different properties. Polymer complexation led to formation of resistant film networks of less solubility and swellability. Water vapor permeability (WVP) was not significantly (P≤0.05) influenced by incorporating CMC into continuous gelatin films. Composite films prepared at MR of 9:1 and pH opt (corresponding to the maximum amount of interaction) revealed different characteristics such as maximum amounts of WVP and swelling and minimum amounts of tensile strength and solubility. FTIR spectra of composite films confirmed that gelatin and CMC were not covalently bonded. Copyright © 2018. Published by Elsevier B.V.

  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 Document Server

    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. ...

  18. 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...

  19. Principles of European Contract Law

    DEFF Research Database (Denmark)

    Lando, Ole; Beale, Hugh

    in developing a common European legal culture. The European Parliament has twice called for the creation of a European Civil Code. The principles of European contract law are essential steps in these projects. This text provides a comprehensive guide to the Principles of European contract law. They have been......This text provides a comprehensive guide to the principles of European contract law. They have been drawn up by an independent body of experts from each Member State of the EU, under a project supported by the European Commission and many other organizations. The principles are stated in the form...... of articles, with a detailed commentary explaining the purpose and operation of each article and its relation to the remainder. Each article also has extensive comparative notes surveying the national laws and other international provisions on the topic. "The Principles of European Contract Law Parts I &...

  20. Reducing repeat pregnancies in adolescence: applying realist principles as part of a mixed-methods systematic review to explore what works, for whom, how and under what circumstances.

    Science.gov (United States)

    Charles, Joanna M; Rycroft-Malone, Jo; Aslam, Rabeea'h; Hendry, Maggie; Pasterfield, Diana; Whitaker, Rhiannon

    2016-09-20

    Previous research has demonstrated emotional, psychological and educational harm to young mothers following unintended conceptions. The UK has one of the highest rates of pregnancies in adolescence in Western Europe with a high proportion of these being repeat pregnancies, making it a topic of interest for public health policy makers, and health and social care practitioners. As part of a wider mixed-methods systematic review, realist principles were applied to synthesise evidence about interventions aiming to reduce repeat pregnancies in adolescence. A multi-streamed, mixed-methods systematic review was conducted searching 11 major electronic databases and 9 additional databases from 1995 onwards, using key terms such as pregnancy, teen or adolescent. The principles of realist synthesis were applied to all included literature to uncover theories about what works, for whom, how and in what context. Initial theory areas were developed through evidence scoping, group discussion by the authors and stakeholder engagement to uncover context + mechanism = outcome (CMO) configurations and related narratives. The searches identified 8,664 documents initially, and 403 in repeat searches, filtering to 81 included studies, including qualitative studies, randomised controlled trials, quantitative studies and grey literature. Three CMO configurations were developed. The individual experiences of young mothers' triggered self-efficacy, notions of perceived risks, susceptibility and benefits of pregnancy, resulting in the adolescent taking control of their fertility and sexual encounters. The choice between motherhood and other goals triggered notions of motivations, resulting in the adolescent managing their expectations of motherhood and controlling their fertility and sexual encounters. Barriers and facilitators to accessing services triggered notions of connectedness and self-determination; resulting in interventions that are tailored so they are relevant to young

  1. 5 CFR 551.202 - General principles.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false General principles. 551.202 Section 551... ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Exemptions and Exclusions § 551.202 General principles. In all exemption determinations, the agency must observe the following principles: (a) Each employee is presumed to...

  2. 24 CFR 3282.402 - General principles.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false General principles. 3282.402... and Remedial Actions § 3282.402 General principles. (a) Nothing in this subpart or in these... manufactured home manufacturers to provide remedial actions under this subpart is limited by the principle that...

  3. Principles of mathematical modeling

    CERN Document Server

    Dym, Clive

    2004-01-01

    Science and engineering students depend heavily on concepts of mathematical modeling. In an age where almost everything is done on a computer, author Clive Dym believes that students need to understand and "own" the underlying mathematics that computers are doing on their behalf. His goal for Principles of Mathematical Modeling, Second Edition, is to engage the student reader in developing a foundational understanding of the subject that will serve them well into their careers. The first half of the book begins with a clearly defined set of modeling principles, and then introduces a set of foundational tools including dimensional analysis, scaling techniques, and approximation and validation techniques. The second half demonstrates the latest applications for these tools to a broad variety of subjects, including exponential growth and decay in fields ranging from biology to economics, traffic flow, free and forced vibration of mechanical and other systems, and optimization problems in biology, structures, an...

  4. Survival, physical and physiological changes of Taenia hydatigena eggs under different conditions of water stress.

    Science.gov (United States)

    Sánchez Thevenet, Paula; Alvarez, Hector Manuel; Basualdo, Juan Angel

    2017-06-01

    Taenia hydatigena eggs were investigated for morphological and physiological changes under water stress conditions. Fresh eggs were exposed at 31%, 47% and 89% of relative humidity (RH), and survival, size and ultrastructural changes were accounted up to 365 days of exposition. The article shows how each RH environment affects the vitality of the eggs. Results of this study suggest that T. hydatigena eggs have mechanisms to withstand water stress, indicating that the eggs clustering improves protection against desiccation, and that endogenous metabolism using triacylglycerols play an important role in the maintenance of embryo vitality under low, medium and high relative humidity conditions. This contributes to understanding the water stress resistance mechanism in eggs belonging to Taeniidae family. The findings shown herein have provided a basis to better comprehend basic biology and epidemiology of the cysticercosis caused by T. hydatigena. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. The proteome of a healthy human during physical activity under extreme conditions

    OpenAIRE

    Larina, I.; Ivanisenko, V.; Nikolaev, E.; Grigorev, A.

    2014-01-01

    The review examines the new approaches in modern systems biology, in terms of their use for a deeper understanding of the physiological adaptation of a healthy human in extreme environments. Human physiology under extreme conditions of life, or environmental physiology, and systems biology are natural partners. The similarities and differences between the object and methods in systems biology, the OMICs (proteomics, transcriptomics, metabolomics) disciplines, and other related sciences have b...

  6. Emulsion Science Basic Principles

    CERN Document Server

    Leal-Calderon, Fernando; Schmitt, Véronique

    2007-01-01

    Emulsions are generally made out of two immiscible fluids like oil and water, one being dispersed in the second in the presence of surface-active compounds.They are used as intermediate or end products in a huge range of areas including the food, chemical, cosmetic, pharmaceutical, paint, and coating industries. Besides the broad domain of technological interest, emulsions are raising a variety of fundamental questions at the frontier between physics and chemistry. This book aims to give an overview of the most recent advances in emulsion science. The basic principles, covering aspects of emulsions from their preparation to their destruction, are presented in close relation to both the fundamental physics and the applications of these materials. The book is intended to help scientists and engineers in formulating new materials by giving them the basics of emulsion science.

  7. Structural phases arising from reconstructive and isostructural transitions in high-melting-point oxides under hydrostatic pressure: A first-principles study

    Science.gov (United States)

    Tian, Hao; Kuang, Xiao-Yu; Mao, Ai-Jie; Yang, Yurong; Xu, Changsong; Sayedaghaee, S. Omid; Bellaiche, L.

    2018-01-01

    High-melting-point oxides of chemical formula A B O3 with A =Ca , Sr, Ba and B =Zr , Hf are investigated as a function of hydrostatic pressure up to 200 GPa by combining first-principles calculations with a particle swarm optimization method. Ca- and Sr-based systems: (1) first undergo a reconstructive phase transition from a perovskite state to a novel structure that belongs to the post-post-perovskite family and (2) then experience an isostructural transition to a second, also new post-post-perovskite state at higher pressures, via the sudden formation of a specific out-of-plane B -O bond. In contrast, the studied Ba compounds evolve from a perovskite phase to a third novel post-post-perovskite structure via another reconstructive phase transition. The original characteristics of these three different post-post-perovskite states are emphasized. Unusual electronic properties, including significant piezochromic effects and an insulator-metal transition, are also reported and explained.

  8. Physical health of young and middle age women under influence of step-aerobics exercises

    Directory of Open Access Journals (Sweden)

    I.P. Masliak

    2015-10-01

    Full Text Available Purpose: to determine the degree of step-aerobics exercises’ influence on 20-35 years age women’s health. Material: in the research 28 women of 20-35 years old age participated. Anthropometric indicators, heart beats rate in rest and after load (20 squats for 30 sec., blood pressure, vital capacity of lungs, hand dynamometry were registered. Results: level of physical health has been determined; influence of step-aerobics on women’s health has been found; age differences in the tested indicators have been analyzed. It was found out that step-aerobic trainings influence greatly on the following indicators: body mass, circumferential sizes and cardio vascular system; on functioning of respiratory system, strength of hand’s flexors and regulation of 31-35 years age women’s cardio-vascular system. Conclusions: application of step-aerobic exercises positively influenced on health of 20-35 years old women.

  9. Physical modeling of flow over an axisymmetric knoll under neutral atmospheric conditions

    International Nuclear Information System (INIS)

    Cliff, W.C.; Smith, J.D.

    1980-02-01

    A glass-walled hydraulic (water) flume was used to model physically air flow near an axisymmetric knoll in a neutral atmospheric boundary layer. The knoll was a 1:250 scale model. An upstream velocity profile (1/7 power law), characteristic of a neutral atmospheric boundary layer, was produced by locating a 10-cm-high (4-in.) trip near the flume entrance and by appropriately roughening the flume floor. Mean velocity, rms velocity, and turbulence intensity profiles were measured at locations near the knoll using an existing laser Doppler anemometer system. The flow accelerated over the knoll and produced a relatively uniform velocity profile at the crest. The measured velocity profile was in close agreement with a theoretical velocity profile developed using potential flow theory and an upstream power law velocity profile. The turbulence intensity decreased at the crest of the knoll as a result of the flow acceleration

  10. Range Verification Methods in Particle Therapy: Underlying Physics and Monte Carlo Modeling

    Science.gov (United States)

    Kraan, Aafke Christine

    2015-01-01

    Hadron therapy allows for highly conformal dose distributions and better sparing of organs-at-risk, thanks to the characteristic dose deposition as function of depth. However, the quality of hadron therapy treatments is closely connected with the ability to predict and achieve a given beam range in the patient. Currently, uncertainties in particle range lead to the employment of safety margins, at the expense of treatment quality. Much research in particle therapy is therefore aimed at developing methods to verify the particle range in patients. Non-invasive in vivo monitoring of the particle range can be performed by detecting secondary radiation, emitted from the patient as a result of nuclear interactions of charged hadrons with tissue, including β+ emitters, prompt photons, and charged fragments. The correctness of the dose delivery can be verified by comparing measured and pre-calculated distributions of the secondary particles. The reliability of Monte Carlo (MC) predictions is a key issue. Correctly modeling the production of secondaries is a non-trivial task, because it involves nuclear physics interactions at energies, where no rigorous theories exist to describe them. The goal of this review is to provide a comprehensive overview of various aspects in modeling the physics processes for range verification with secondary particles produced in proton, carbon, and heavier ion irradiation. We discuss electromagnetic and nuclear interactions of charged hadrons in matter, which is followed by a summary of some widely used MC codes in hadron therapy. Then, we describe selected examples of how these codes have been validated and used in three range verification techniques: PET, prompt gamma, and charged particle detection. We include research studies and clinically applied methods. For each of the techniques, we point out advantages and disadvantages, as well as clinical challenges still to be addressed, focusing on MC simulation aspects. PMID:26217586

  11. Range Verification Methods in Particle Therapy: Underlying Physics and Monte Carlo Modeling.

    Science.gov (United States)

    Kraan, Aafke Christine

    2015-01-01

    Hadron therapy allows for highly conformal dose distributions and better sparing of organs-at-risk, thanks to the characteristic dose deposition as function of depth. However, the quality of hadron therapy treatments is closely connected with the ability to predict and achieve a given beam range in the patient. Currently, uncertainties in particle range lead to the employment of safety margins, at the expense of treatment quality. Much research in particle therapy is therefore aimed at developing methods to verify the particle range in patients. Non-invasive in vivo monitoring of the particle range can be performed by detecting secondary radiation, emitted from the patient as a result of nuclear interactions of charged hadrons with tissue, including β (+) emitters, prompt photons, and charged fragments. The correctness of the dose delivery can be verified by comparing measured and pre-calculated distributions of the secondary particles. The reliability of Monte Carlo (MC) predictions is a key issue. Correctly modeling the production of secondaries is a non-trivial task, because it involves nuclear physics interactions at energies, where no rigorous theories exist to describe them. The goal of this review is to provide a comprehensive overview of various aspects in modeling the physics processes for range verification with secondary particles produced in proton, carbon, and heavier ion irradiation. We discuss electromagnetic and nuclear interactions of charged hadrons in matter, which is followed by a summary of some widely used MC codes in hadron therapy. Then, we describe selected examples of how these codes have been validated and used in three range verification techniques: PET, prompt gamma, and charged particle detection. We include research studies and clinically applied methods. For each of the techniques, we point out advantages and disadvantages, as well as clinical challenges still to be addressed, focusing on MC simulation aspects.

  12. Anthropometric characteristics, physical fitness and technical performance of under-19 soccer players by competitive level and field position

    DEFF Research Database (Denmark)

    Rebelo, A; Brito, J; Maia, J

    2013-01-01

    Anthropometric characteristics, physical fitness and technical skills of under-19 (U19) soccer players were compared by competitive level (elite, n=95; non-elite, n=85) and playing position (goalkeeper, central defender, fullback, midfield, forward). Fitness tests included 5- and 30-m sprints...... and ball control tests (d>1.2). Elite players presented better agility and Yo-Yo IE2 performances than non-elite players within all positional roles (d>0.6). In conclusion, U19 players differed in anthropometric characteristics, physical fitness and technical skills by competitive level within field......, agility, squat jump (SJ) and countermovement jump (CMJ), strength and Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2). Soccer-specific skills included ball control and dribbling. Independent of position, elite players presented more hours of training per year than non-elite players (d>1.2). Stature...

  13. Dynamics of Physical and Physicochemical Properties of Urban Soils under the Effect of Ice-Melting Salts

    Science.gov (United States)

    Azovtseva, N. A.; Smagin, A. V.

    2018-01-01

    Physical (water content, density, and air and water regimes) and physicochemical (electrical conductivity, pH, and SAR) properties of urban soils were investigated on test plots of Moscow to evaluate their dynamics under anthropogenic impact. The wilting point and the dependence of the capillary-sorption and total water potentials of the soil water content were determined in laboratory experiments with natural and artificially saline soil samples to evaluate the effect of salt antifreeze substances on water availability for plants under conditions of active application of deicing reagents. Seasonal dynamics of these parameters were investigated. It was found that electrolytes display a steady tendency for the accumulation and redistribution in the root zone rather than for their deep leaching despite humid climatic conditions in Moscow megalopolis. In summer, regular droughts result in drying of the root zone to critical values and to the concentration of electrolytes up to the values that make the total water potential of soil unsuitable for water uptake by roots. The key factor of soil degradation under the impact of electrolytes is the soil dispersity: the finer the texture, the higher the soil salinization and solonetzicity and the stronger irreversible changes in the soil water retention capacity and physical properties.

  14. Radiation Physics for Medical Physicists

    CERN Document Server

    Podgorsak, Ervin B

    2010-01-01

    This well-received textbook and reference summarizes the basic knowledge of atomic, nuclear, and radiation physics that professionals working in medical physics and biomedical engineering need for efficient and safe use of ionizing radiation. Concentrating on the underlying principles of radiation physics, it covers the prerequisite knowledge for medical physics courses on the graduate and post-graduate levels in radiotherapy physics, radiation dosimetry, imaging physics, and health physics, thus providing the link between elementary physics on the one hand and the intricacies of the medical physics specialties on the other hand. This expanded and revised second edition offers reorganized and expanded coverage. Several of the original chapters have been split into two with new sections added for completeness and better flow. New chapters on Coulomb scattering; on energy transfer and energy absorption in photon interactions; and on waveguide theory have been added in recognition of their importance. Others tra...

  15. 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...

  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

    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...

  18. PHYSICS

    CERN Document Server

    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

    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...

  20. 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 ...

  1. The gauge principle vs. the equivalence principle

    International Nuclear Information System (INIS)

    Gates, S.J. Jr.

    1984-01-01

    Within the context of field theory, it is argued that the role of the equivalence principle may be replaced by the principle of gauge invariance to provide a logical framework for theories of gravitation

  2. Determination of equilibrium composition of thermally ionized monoatomic gas under different physical conditions

    Science.gov (United States)

    Romanova, M. S.; Rydalevskaya, M. A.

    2017-05-01

    Perfect gas mixtures that result from thermal ionization of spatially and chemically homogeneous monoatomic gases are considered. Equilibrium concentrations of the components of such mixtures are determined using integration over the momentum space and summation with respect to energy levels of the distribution functions that maximize the entropy of system under condition for constancy of the total number of nuclei and electrons. It is demonstrated that such a method allows significant simplification of the calculation of the equilibrium composition for ionized mixtures at different temperatures and makes it possible to study the degree of ionization of gas versus gas density and number in the periodic table of elements.

  3. Effect of physical training on metabolic responses of pregnant rats submitted to swimming under thermal stress

    Directory of Open Access Journals (Sweden)

    Rodrigo Alexis Lazo-Osorio

    2009-08-01

    Full Text Available

    • BACKGROUND: The aim of this study is to assess the effect of pre-pregnancy physical training on metabolic responses and its effects on offspring.
    • METHODS: Three groups of rats (n = 7 in each group: sedentary pregnant rats (PS, exercised during  regnancy (PE and pregnant rats trained before and during pregnancy (PT were compared. They were separated  nto three subgroups regarding water temperature: 28°C, 35°C or 39°C. Plasma triglycerides and glucose levels,  eight gain during pregnancy and rectal temperature pre and post exercise (swim, as well as the offspring size and weight were analysed.
    • RESULTS: Rectal temperature post exercise was lower than pre exercise at 28°C and 35°C, and higher at 39°C.  eight gain was lower at 39°C for the PT group and at 35°C for the PT and PE groups compared to the PS group. Plasma glucose, at 28°C and 39°C for PS and PE groups, was higher than those obtained at 35°C, while triglycerides  ere lower. For trained rats, plasma glucose and triglycerides were similar at all water temperatures.  rained rats presented lower triglyceride values at 35°C, and higher triglyceride values at 39°C compared to PS  roup. Glucose presented inverse results. None of the groups presented fetal reabsorption. However, in the PS group, the offspring presented lower weight gain at 28

    • Assessment of soil organic matter persistence under different land uses applying a physical fractionation procedure

      Science.gov (United States)

      Giannetta, Beatrice; Plaza, César; López-de-Sá, Esther G.; Vischetti, Costantino; Zaccone, Claudio

      2017-04-01

      The understanding of the mechanisms involved in the build-up of soil organic matter (SOM) pools with long residence time is tightly linked to the comprehension of C dynamics. Organo-mineral associations are known to be strongly correlated with the accumulation of selective preserved C forms. Adsorption to minerals, as well as occlusion within aggregates, may affect SOM protection in different ways depending on its molecular structure and pedo-climatic conditions. In this research, we investigated changes in quantity and quality of SOM pools characterized by different protection mechanisms in coniferous and broadleaved forest soils, grassland soils, technosols and an agricultural soil with different organic amendments, in order to evaluate the influence of both land use and organic matter nature on physical and/or chemical stabilization of SOM. In particular, free (FR), intra-macroaggregate (MA), intra-microaggregate (MI), and mineral-associated (Min) fractions were separated in order to define physical and chemical mechanisms responsible for the SOM protection against degradation. All these SOM fractions were analyzed for organic C and total N concentration, and their stability assessed by thermogravimetric analysis (TD-TGA). Preliminary data show that, for all land uses, most of the organic C (40-60%) is found in the Min pool, followed by FR (20-40%)>MI MA. With the only exception of the FR, no significant correlations were found between the C/N ratio and a thermal stability index (H550-400/400-250) of each fraction; at the same time, a highly significant and positive correlation was found between these two parameters in all fractions isolated from agricultural soils. In particular, the thermal stability index measured in all Min fractions may be related to the more marked presence of labile compounds in this pool relative to recalcitrant compounds. Conversely, FR OM could not always represent a fresh and readily decomposable fraction.Furthermore, OM associated

    • Equivalence principles and electromagnetism

      Science.gov (United States)

      Ni, W.-T.

      1977-01-01

      The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

    • Physical Modeling of Shear Behavior of Infilled Rock Joints Under CNL and CNS Boundary Conditions

      Science.gov (United States)

      Shrivastava, Amit Kumar; Rao, K. Seshagiri

      2018-01-01

      Despite their frequent natural occurrence, filled discontinuities under constant normal stiffness (CNS) boundary conditions have been studied much less systematically, perhaps because of the difficulties arising from the increased number of variable parameters. Because of the lack of reliable and realistic theoretical or empirical relations and the difficulties in obtaining and testing representative samples, engineers rely on judgment and often consider the shear strength of the infilled material itself as shear strength of rock joints. This assumption leads to uneconomical and also sometimes the unsafe design of underground structures, slopes, rock-socketed piles and foundations. To study the effect of infill on the shear behavior of rock joints, tests were performed on the modeled infilled rock joint having different joint roughness under constant normal load (CNL) and CNS boundary conditions at various initial normal stress and varying thickness of the infilled material. The test results indicate that shear strength decreases with an increase in t/ a ratio for both CNL and CNS conditions, but the reduction in shear strength is more for CNL than for CNS condition for a given initial normal stress. The detailed account of the effect of thickness of infilled material on shear and deformation behavior of infilled rock joint is discussed in this paper, and a model is proposed to predict shear strength of infilled rock joint.

    • Understanding physical rock properties and their relation to fluid-rock interactions under supercritical conditions

      Science.gov (United States)

      Kummerow, Juliane; Raab, Siegfried; Meyer, Romain

      2017-04-01

      The electrical conductivity of rocks is, in addition to lithological factors (mineralogy, porosity) and physical parameters (temperature, pressure) sensitive to the nature of pore fluids (phase, salinity), and thus may be an indicative measure for fluid-rock interactions. Especially near the critical point, which is at 374.21° C and 22.12 MPa for pure water, the physico-chemical properties of aqueous fluids change dramatically and mass transfer and diffusion-controlled chemical reactivity are enhanced, which in turn leads to the formation of element depletion/ enrichment patterns or cause mineral dissolution. At the same time, the reduction of the dielectric constant of water promotes ion association and consequently mineral precipitation. All this cause changes in the electrical conductivity of geothermal fluids and may have considerable effects on the porosity and hydraulic properties of the rocks with which they are in contact. In order to study the impact of fluid-rock interactions on the physical properties of fluids and rocks in near- and supercritical geological settings in more detail, in the framework of the EU-funded project "IMAGE" (Integrated Methods for Advanced Geothermal Exploration) hydraulic and electrical properties of rock cores from different active and exhumed geothermal areas on Iceland were measured up to supercritical conditions (Tmax = 380° C, pfluid = 23 MPa) during long-term (2-3 weeks) flow-through experiments in an internally heated gas pressure vessel at a maximum confining pressure of 42 MPa. In a second flow-through facility both the intrinsic T-dependent electrical fluid properties as well as the effect of mineral dissolution/ precipitation on the fluid conductivity were measured for increasing temperatures in a range of 24 - 422° C at a constant fluid pressure of 31 MPa. Petro- and fluid physical measurements were supplemented by a number of additional tests, comprising microstructural investigations as well as the chemical

    • Physics at 13 TeV: ALICE - scratching under the surface

      CERN Multimedia

      Antonella Del Rosso

      2014-01-01

      ALICE’s wonderland materialises where the lead-lead ultrarelativistic collisions happen in the LHC. With a jump of over one order of magnitude in collision energy from the Relativistic Heavy Ion Collider (RHIC) and using state-of-the-art detectors, the experiment studies the quark-gluon plasma, a state of matter that existed during the Universe’s infancy.   The hugely hot medium was observed to behave almost like an ideal fluid, which, although absorbing their energy, leaves single propagating quarks and gluons almost undeflected, enhances the production of strange quarks, suppresses the production of particles made of quarks and antiquarks, and seems to be emitting light in the early stages of its expansion. “The data from the first LHC run have already challenged some of the notions that had emerged from the previous RHIC programme,” says Federico Antinori, ALICE Physics Coordinator. “The abundance of hard probes, that is, high-energy partic...

    • The landscape of theoretical physics a global view from point particles to the brane world and beyond, in search of a unifying principle

      CERN Document Server

      Pavšič, Matej

      2002-01-01

      This a book is for those who would like to learn something about special and general relativity beyond the usual textbooks, about quantum field theory, the elegant Fock-Schwinger-Stueckelberg proper time formalism, the elegant description of geometry by means of Clifford algebra, about the fascinating possibilities the latter algebra offers in reformulating the existing physical theories, and quantizing them in a natural way. It is shown how Clifford algebra provides much more: it provides room for new physics, with the prospects of resolving certain long standing puzzles. The theory of branes and the idea of how a 3-brane might represent our world is discussed in detail. Much attention is paid to the elegant geometric theory of branes which employs the infinite dimensional space of functions describing branes. Clifford algebra is generalized to the infinite dimensional spaces. In short, this is a book for anybody who would like to explore how the ``theory of everything'' might possibly be formulated. The the...

    • [Physical and chemical evaluation during refrigeration storage of salted catfish (Pseudoplatystoma sp.) in brine solution, and packed under vacuum].

      Science.gov (United States)

      Rodríguez, Diana; Barrero, Marinela; Kodaira, Makie

      2009-06-01

      Salting fish in the south Venezuelan towns are still the main method of preserving fish including cutt, and salting fish process, storage and commercialization. As the result, salted-dried fish is particularly susceptible to spoilage by a number of factors, including lipid oxidation, browning meat. Packing salted fish product is an alternative increasing storage life time reducing lost of quality and enhancing the storage time. The present study evaluated the physic, chemist, and sensory quality of fish fillet from cat fish (Pseudoplatystoma sp.) from Apure state, Venezuela. Fillet fish were placed in brine solution at 36% of sodium chloride 1:2 fillet: brine solution; after, they were packed under followed conditions: vacuum, vacuum and storage under refrigeration condition, and room temperature. The results showed significant differences (p refrigeration temperature after three moths. The best conditions treatment was vacuum packing and refrigeration at 4 degrees C.

    • Existence of dark matter with observed properties of cosmic microwave background radiation substantiates three conservation laws of classical physics and all principles of quantum mechanics as creates the value of Planck’s constant

      Science.gov (United States)

      Boriev, I. A.

      2018-03-01

      Astronomical data indicate a presence of dark matter (DM) in the space, what is necessary for explanation of observed dynamics of the galaxies within Newtonian mechanics. DM, at its very low density (∼10-26kg/m3), constitutes main part of the matter in the Universe, 10 times the mass of all visible cosmic bodies. No doubt, namely properties of DM, which fills space, must determine its physical properties and fundamental physical laws. Taking into account observed properties of cosmic microwave background radiation (CMBR), whose energy is ∼90% of all cosmic radiation, and understanding that this radiation is produced by DM motion, conservation laws of classical physics and principles of quantum mechanics receive their materialistic substantiation. Thus, CMBR high homogeneity and isotropy (∼10-4), and hence the same properties of DM (and space) justify momentum and angular momentum conservation laws, respectively, according to E. Noether's theorems. CMBR has black body spectrum at ∼2.7K with maximum wavelength ∼1.9·10-3m, what allows calculate the value of mechanical action produced by DM thermal motion (∼7·10-34 J·s). This value corresponds well to the Planck’s constant, which is the mechanical action too, what gives materialistic basis for all principles of quantum mechanics. Obtained results directly confirm the reality of DM existence, and show that CMBR is an observed display of DM thermal motion. Understanding that namely from DM occur known creation of electron-positron pairs as contrarily rotating material vortexes (according to their spins) let substantiate positron nature of ball lightning what first explains all its observed specific properties.

    • Symmetry Principles and Conservation Laws in Atomic and ...

      Indian Academy of Sciences (India)

      We have now seen that both the equation of motion and the conservation principles result from the single principle of least action. Moreover, the same principle provides for the connection between symmetry and con- servation laws, exalted by Noether to one of the most profound principles in contemporary physics. We now.

    • PHYSICS

      CERN Document Server

      C. Hill

      2013-01-01

      The period since the last CMS bulletin has seen the end of proton collisions at a centre-of-mass energy 8 TeV, a successful proton-lead collision run at 5 TeV/nucleon, as well as a “reference” proton run at 2.76 TeV. With these final LHC Run 1 datasets in hand, CMS Physics Analysis Groups have been busy analysing these data in preparation for the winter conferences. Moreover, despite the fact that the pp run only concluded in mid-December (and there was consequently less time to complete data analyses), CMS again made a strong showing at the Rencontres de Moriond in La Thuile (EW and QCD) where nearly 40 new results were presented. The highlight of these preliminary results was the eagerly anticipated updated studies of the properties of the Higgs boson discovered in July of last year. Meanwhile, preparations for Run 2 and physics performance studies for Phase 1 and Phase 2 upgrade scenarios are ongoing. The Higgs analysis group produced updated analyses on the full Run 1 dataset (~25 f...

    • PHYSICS

      CERN Multimedia

      C. Hill

      2013-01-01

      In the period since the last CMS Bulletin, the LHC – and CMS – have entered LS1. During this time, CMS Physics Analysis Groups have performed more than 40 new analyses, many of which are based on the complete 8 TeV dataset delivered by the LHC in 2012 (and in some cases on the full Run 1 dataset). These results were shown at, and well received by, several high-profile conferences in the spring of 2013, including the inaugural meeting of the Large Hadron Collider    Physics Conference (LHCP) in Barcelona, and the 26th International Symposium on Lepton Photon Interactions at High Energies (LP) in San Francisco. In parallel, there have been significant developments in preparations for Run 2 of the LHC and on “future physics” studies for both Phase 1 and Phase 2 upgrades of the CMS detector. The Higgs analysis group produced five new results for LHCP including a new H-to-bb search in VBF production (HIG-13-011), ttH with H to γ&ga...

    • PHYSICS

      CERN Multimedia

      J. D'Hondt

      The Electroweak and Top Quark Workshop (16-17th of July) A Workshop on Electroweak and Top Quark Physics, dedicated on early measurements, took place on 16th-17th July. We had more than 40 presentations at the Workshop, which was an important milestone for 2007 physics analyses in the EWK and TOP areas. The Standard Model has been tested empirically by many previous experiments. Observables which are nowadays known with high precision will play a major role for data-based CMS calibrations. A typical example is the use of the Z to monitor electron and muon reconstruction in di-lepton inclusive samples. Another example is the use of the W mass as a constraint for di-jets in the kinematic fitting of top-quark events, providing information on the jet energy scale. The predictions of the Standard Model, for what concerns proton collisions at the LHC, are accurate to a level that the production of W/Z and top-quark events can be used as a powerful tool to commission our experiment. On the other hand the measure...

    • PHYSICS

      CERN Multimedia

      Christopher Hill

      2013-01-01

      Since the last CMS Bulletin, the CMS Physics Analysis Groups have completed more than 70 new analyses, many of which are based on the complete Run 1 dataset. In parallel the Snowmass whitepaper on projected discovery potential of CMS for HL-LHC has been completed, while the ECFA HL-LHC future physics studies has been summarised in a report and nine published benchmark analyses. Run 1 summary studies on b-tag and jet identification, quark-gluon discrimination and boosted topologies have been documented in BTV-13-001 and JME-13-002/005/006, respectively. The new tracking alignment and performance papers are being prepared for submission as well. The Higgs analysis group produced several new results including the search for ttH with H decaying to ZZ, WW, ττ+bb (HIG-13-019/020) where an excess of ~2.5σ is observed in the like-sign di-muon channel, and new searches for high-mass Higgs bosons (HIG-13-022). Search for invisible Higgs decays have also been performed both using the associ...

    • Synchronized personalized music audio-playlists to improve adherence to physical activity among patients participating in a structured exercise program: a proof-of-principle feasibility study.

      Science.gov (United States)

      Alter, David A; O'Sullivan, Mary; Oh, Paul I; Redelmeier, Donald A; Marzolini, Susan; Liu, Richard; Forhan, Mary; Silver, Michael; Goodman, Jack M; Bartel, Lee R

      2015-01-01

      Preference-based tempo-pace synchronized music has been shown to reduce perceived physical activity exertion and improve exercise performance. The extent to which such strategies can improve adherence to physical activity remains unknown. The objective of the study is to explore the feasibility and efficacy of tempo-pace synchronized preference-based music audio-playlists on adherence to physical activity among cardiovascular disease patients participating in a cardiac rehabilitation. Thirty-four cardiac rehabilitation patients were randomly allocated to one of two strategies: (1) no music usual-care control and (2) tempo-pace synchronized audio-devices with personalized music playlists + usual-care. All songs uploaded onto audio-playlist devices took into account patient personal music genre and artist preferences. However, actual song selection was restricted to music whose tempos approximated patients' prescribed exercise walking/running pace (steps per minute) to achieve tempo-pace synchrony. Patients allocated to audio-music playlists underwent further randomization in which half of the patients received songs that were sonically enhanced with rhythmic auditory stimulation (RAS) to accentuate tempo-pace synchrony, whereas the other half did not. RAS was achieved through blinded rhythmic sonic-enhancements undertaken manually to songs within individuals' music playlists. The primary outcome consisted of the weekly volume of physical activity undertaken over 3 months as determined by tri-axial accelerometers. Statistical methods employed an intention to treat and repeated-measures design. Patients randomized to personalized audio-playlists with tempo-pace synchrony achieved higher weekly volumes of physical activity than did their non-music usual-care comparators (475.6 min vs. 370.2 min, P  music usual-care controls, respectively, P  music with RAS utilized their audio-playlist devices more frequently than did non-RAS music counterparts ( P

    • Can quantum probes satisfy the weak equivalence principle?

      Energy Technology Data Exchange (ETDEWEB)

      Seveso, Luigi, E-mail: luigi.seveso@unimi.it [Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I-20133 Milano (Italy); Paris, Matteo G.A. [Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I-20133 Milano (Italy); INFN, Sezione di Milano, I-20133 Milano (Italy)

      2017-05-15

      We address the question whether quantum probes in a gravitational field can be considered as test particles obeying the weak equivalence principle (WEP). A formulation of the WEP is proposed which applies also in the quantum regime, while maintaining the physical content of its classical counterpart. Such formulation requires the introduction of a gravitational field not to modify the Fisher information about the mass of a freely-falling probe, extractable through measurements of its position. We discover that, while in a uniform field quantum probes satisfy our formulation of the WEP exactly, gravity gradients can encode nontrivial information about the particle’s mass in its wavefunction, leading to violations of the WEP. - Highlights: • Can quantum probes under gravity be approximated as test-bodies? • A formulation of the weak equivalence principle for quantum probes is proposed. • Quantum probes are found to violate it as a matter of principle.

    • Biological and physical factors controlling aggregate stability under different climatic conditions in Southern Spain.

      Science.gov (United States)

      Ángel Gabarrón-Galeote, Miguel; Damián Ruiz-Sinoga, Jose; Francisco Martinez-Murillo, Juan; Lavee, Hanoch

      2013-04-01

      Soil aggregation is a key factor determining the soil structure. The presence of stable aggregates is essential to maintain a good soil structure, that in turn plays an important role in sustaining agricultural productivity and preserving environmental quality. A wide range of physical and biological soil components are involved in the aggregate formation and stabilization, namely clay mineral content; the quantity and quality of organic matter, that can be derived from plants, fungal hyphae, microorganism and soil animals; and the soil water content. Climatic conditions, through their effect on soil water content, vegetation cover and organic matter content, are supposed to affect soil aggregation. Thus the main objective of this research is to analyse the effect of organic matter, clay content and soil water content on aggregate stability along a climatic transect in Southern Spain. This study was conducted in four catchments along a pluviometric gradient in the South of Spain (rainfall depth decreases from west to east from more than 1000 mm year-1 to less than 300 mm year-1) and was based on a methodology approximating the climatic gradient in Mediterranean conditions. The selected sites shared similar conditions of geology, topography and soil use, which allowed making comparisons among them and relating the differences to the pluviometric conditions. In February 2007, 250 disturbed and undisturbed samples from the first 5cm of the soil were collected along the transect. We measured the aggregate stability, organic matter, clay content and bulk density of every sample. In the field we measured rainfall, air temperature, relative humidity, wind speed, wind direction, solar radiation, potential evapotranspiration, soil water content, vegetation cover and presence of litter. Our results suggest that aggregate stability is a property determined by a great number of highly variable factors, which can make extremely difficult to predict its behavior taking in

    • Mineralogical, textural and physical-mechanical study of hydraulic lime mortars cured under different moisture conditions

      Directory of Open Access Journals (Sweden)

      Arizzi, A.

      2015-06-01

      Full Text Available This work focuses on the chemical-mineralogical, textural and physical-mechanical properties of hydraulic lime mortars made with siliceous and calcareous aggregate. Mortars were cured at 60% and 90% of relative humidity, so as to assess the variability of mortar petrophysical properties in the hardened state due to the moisture conditions. The final aim was to determine the most adequate moisture conditions to be maintained during application and hardening of hydraulic mortars intended for repair interventions. We found out that using a calcareous aggregate and curing mortar at 90% of relative humidity give place to better textural and mechanical properties. However, these characteristics mostly depend on the maximum size of the aggregate grains, which should be smaller than 6 mm, in order to avoid the occurrence of mechanical discontinuities in the mortar.En este trabajo se han estudiado las propiedades químico-mineralógicas, texturales y físico-mecánicas de morteros de cal hidráulica elaborados con áridos silíceo y calcítico. Estos morteros se han curado al 60% y 90% de humedad relativa, con el fin de evaluar las eventuales diferencias en las propiedades petrofísicas de los morteros una vez endurecidos y así establecer cuál de los dos ambientes es recomendable durante la aplicación y fraguado de morteros de cal hidráulica destinados a obras de restauración. Se ha encontrado que el uso de un árido de composición calcítica y el curado al 90% de humedad relativa dan lugar a morteros hidráulicos con mejores características texturales y propiedades mecánicas. De todas formas, estas características dependen principalmente del tamaño máximo del árido empleado, que debería ser inferior a 6 mm para evitar discontinuidades mecánicas en el mortero.

  1. Bacterial biofilm under flow: First a physical struggle to stay, then a matter of breathing.

    Directory of Open Access Journals (Sweden)

    Philippe Thomen

    Full Text Available Bacterial communities attached to surfaces under fluid flow represent a widespread lifestyle of the microbial world. Through shear stress generation and molecular transport regulation, hydrodynamics conveys effects that are very different by nature but strongly coupled. To decipher the influence of these levers on bacterial biofilms immersed in moving fluids, we quantitatively and simultaneously investigated physicochemical and biological properties of the biofilm. We designed a millifluidic setup allowing to control hydrodynamic conditions and to monitor biofilm development in real time using microscope imaging. We also conducted a transcriptomic analysis to detect a potential physiological response to hydrodynamics. We discovered that a threshold value of shear stress determined biofilm settlement, with sub-piconewton forces sufficient to prevent biofilm initiation. As a consequence, distinct hydrodynamic conditions, which set spatial distribution of shear stress, promoted distinct colonization patterns with consequences on the growth mode. However, no direct impact of mechanical forces on biofilm growth rate was observed. Consistently, no mechanosensing gene emerged from our differential transcriptomic analysis comparing distinct hydrodynamic conditions. Instead, we found that hydrodynamic molecular transport crucially impacts biofilm growth by controlling oxygen availability. Our results shed light on biofilm response to hydrodynamics and open new avenues to achieve informed design of fluidic setups for investigating, engineering or fighting adherent communities.

  2. Buckling Behavior of Carbon Nanotubes Functionalized with Carbene under Physical Adsorption of Polymer Chains: a Molecular Dynamics Study

    Science.gov (United States)

    Ajori, S.; Haghighi, S.; Ansari, R.

    2017-12-01

    The buckling analysis of functionalized carbon nanotubes (CNTs) is of great importance for the better understanding of mechanical behavior of nanocomposites. The buckling behavior of carbene-functionalized CNTs (cfCNTs) under physical adsorption of polymer chains (cfCNTs/polymers) is studied in this paper by the classical molecular dynamics (MD) simulations. In this regard, to investigate the interactions between non-covalent polymer chains and cfCNTs, two different non-covalent functional groups, i.e. polycarbonate (PC) and polypropylene (PP), are selected. The findings are compared with those of pure CNTs under the physical adsorption of polymer chains (pCNTs/polymers). The obtained results show that at a given weight percentage of non-covalent functional groups, the gyration radius of cfCNTs/polymers is higher than that of pCNTs/polymers. Furthermore, an increase in the critical buckling force of cfCNTs/polymers is dependent on the type of non-covalent polymer chains. For cfCNTs/PC and cfCNTs/PP, the critical buckling force is respectively lower and higher than that of pCNTs/polymers for the similar weight percentage of non-covalent functional groups. In addition, it is found that the critical buckling strain of cfCNTs/polymers is smaller than that of pCNTs/polymers for the same weight percentage of non-covalent polymer chains.

  3. A framework for back-up and restore under the Experimental Physics and Industrial Control System

    International Nuclear Information System (INIS)

    Karonis, N.T.

    1992-12-01

    EPICS is a system that allows one to design and implement a controls system. At its foundation, i.e., the level closest to the devices being controlled, are autonomous computers, each called an Input/Output Controller or IOC. In EPICS, devices controlled by an IOC are represented by software entities called process variables. All devices are monitored/controlled by reading/writing values from/to their associated process variables. Under this schema, distributing processing over a number of IOCs and representing devices with process variables, there are a variety of ways one can view or group the information in the control system. Two of the more common groupings are by IOC (location) and by devices (function). Simply stated, the authors require a system capable of restoring the state of the machine, in their case the Advanced Photon Source, to a known desired state from somewhere in the past. To that end, they propose a framework which describes a system that periodically records and preserves the values of key process variables so that later on, those values can be written to the machine in an attempt to restore it to that same state. One of the more powerful notions that must be preserved in any system that solves this problem is the independence between the specification of what is monitored and the specification of what is written. In other words, grouping process variables for monitoring must be kept independent of the number of different ways to group process variables (e.g., by IOC, by device, etc.) when they are written

  4. Contribution of raindrop impact to the change of soil physical properties and water erosion under semi-arid rainfalls.

    Science.gov (United States)

    Vaezi, Ali Reza; Ahmadi, Morvarid; Cerdà, Artemi

    2017-04-01

    Soil erosion by water is a three-phase process that consists of detachment of soil particles from the soil mass, transportation of detached particles either by raindrop impact or surface water flow, and sedimentation. Detachment by raindrops is a key component of the soil erosion process. However, little information is available on the role of raindrop impact on soil losses in the semi-arid regions where vegetation cover is often poor and does not protect the soil from rainfall. The objective of this study is to determine the contribution of raindrop impact to changes in soil physical properties and soil losses in a semiarid weakly-aggregated agricultural soil. Soil losses were measured under simulated rainfalls of 10, 20, 30, 40, 50, 60 and 70mmh -1 , and under two conditions: i) with raindrop impact; and, ii) without raindrop impact. Three replications at each rainfall intensity and condition resulted in a total of 42 microplots of 1m×1.4m installed on a 10% slope according to a randomized complete block design. The contribution of raindrop impact to soil loss was computed using the difference between soil loss with raindrop impact and without raindrop impact at each rainfall intensity. Soil physical properties (aggregate size, bulk density and infiltration rate) were strongly damaged by raindrop impact as rainfall intensity increased. Soil loss was significantly affected by rainfall intensity under both soil surface conditions. The contribution of raindrop impact to soil loss decreased steadily with increasing rainfall intensity. At the lower rainfall intensities (20-30mmh -1 ), raindrop impact was the dominant factor controlling soil loss from the plots (68%) while at the higher rainfall intensities (40-70mmh -1 ) soil loss was mostly affected by increasing runoff discharge. At higher rainfall intensities the sheet flow protected the soil from raindrop impact. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. [Heidaigou Opencast Coal Mine: Soil Enzyme Activities and Soil Physical and Chemical Properties Under Different Vegetation Restoration].

    Science.gov (United States)

    Fang, Ying; Ma, Ren-tian; An, Shao-shan; Zhao, Jun-feng; Xiao, Li

    2016-03-15

    Choosing the soils under different vegetation recovery of Heidaigou dump as the research objects, we mainly analyzed their basic physical and chemical properties and enzyme activities with the method of Analysis of Variance as well as their relations using Pearson correlation analysis and path analysis hoping to uncover the driving factors of the differences between soil enzyme activities under different vegetation restoration, and provide scientific suggestions for the plant selection as well as make a better evaluation to the reclamation effect. The results showed that: (1) Although the artificial vegetation restoration improved the basic physical and chemical properties of the soils while increasing their enzyme activities to a certain extent, the soil conditions still did not reach the level of the natural grassland; (2) Contents of soil organic carbon (SOC) and soil total nitrogen (TN) of the seabuckthorns were the nearest to those of the grassland, which reached 54. 22% and 70. 00% of those of the grassland. In addition, the soil bulk density of the seabuckthorns stand was 17. 09% lower than the maximum value of the amorpha fruitcosa land. The SOC and TN contents as well as the bulk density showed that seabuckthorns had advantages as the species for land reclamation of this dump; Compared with the seabuckthorn, the pure poplar forest had lower contents of SOC and TN respectively by 35.64% and 32.14% and displayed a 16.79% higher value of soil bulk density; (3) The activities of alkaline phosphotase under different types of vegetation rehabilitation had little variation. But soil urease activities was more sensitive to reflect the effects of vegetation restoration on soil properties; (4) Elevation of the SOC and TN turned out to be the main cause for soil fertility restoration and increased biological activities of the dump.

  6. Effect of potassium and calcium loading on healthy subjects under hypokinesia and physical exercise with fluid and salt supplements

    Science.gov (United States)

    Zorbas, Yan G.; Naexu, Konstantin A.; Federenko, Youri F.

    1995-08-01

    The objective of this investigation was to determine the acute responses to the electrolyte challenges under hypokinesia and physical exercise (PE) of different intensities with fluid and salt supplementation (FSS). The studies were performed on 12 physically healthy male volunteers aged 19-24 years under 364 days of hypokinesia (decreased number of steps per day) with a set of PE with FSS. The volunteers were divided into two equal groups. The first group was subjected to a set of intensive PE and the second group was submitted to a set of moderate PE. Both groups of subjects consumed daily water and salt supplements that aimed to increase the body hydration level. For simulation of the hypokinetic effect all subjects were kept under an average of 3000 steps per day. Functional tests with a potassium chloride (KCl) and calcium lactate (Cal) load were performed during the hypokinetic period of 364 days and the 60-day prehypokinetic period that served as control, while both groups of subjects consumed daily calcium and potassium supplements. The concentration of electrolyte and hormone levels in the blood and their excretion rate in urine were determined. Renal excretion of calcium and potassium and the blood concentration thereof increased markedly in both groups of subjects. With the potassium chloride load tests the increased potassium excretion was accompanied by higher aldosterone and insulin blood levels, and with the calcium lactate load tests the increased calcium excretion was accompanied by a decreased parathyroid content in the blood. FSS and PE, regardless of intensity, failed to attenuate calcium and potassium losses. Additional intake of KCl and Cal also failed to normalize potassium and calcium abnormalities. It was concluded that during the KCl and Cal loading tests, the increased losses of potassium and calcium in the hypokinetic subjects were due to the inability of their bodies to retain these electrolytes, and that electrolyte abnormalities could

  7. Progress in classical and quantum variational principles

    International Nuclear Information System (INIS)

    Gray, C G; Karl, G; Novikov, V A

    2004-01-01

    We review the development and practical uses of a generalized Maupertuis least action principle in classical mechanics in which the action is varied under the constraint of fixed mean energy for the trial trajectory. The original Maupertuis (Euler-Lagrange) principle constrains the energy at every point along the trajectory. The generalized Maupertuis principle is equivalent to Hamilton's principle. Reciprocal principles are also derived for both the generalized Maupertuis and the Hamilton principles. The reciprocal Maupertuis principle is the classical limit of Schroedinger's variational principle of wave mechanics and is also very useful to solve practical problems in both classical and semiclassical mechanics, in complete analogy with the quantum Rayleigh-Ritz method. Classical, semiclassical and quantum variational calculations are carried out for a number of systems, and the results are compared. Pedagogical as well as research problems are used as examples, which include nonconservative as well as relativistic systems. '... the most beautiful and important discovery of Mechanics.' Lagrange to Maupertuis (November 1756)

  8. Le Chatelier principle in replicator dynamics

    OpenAIRE

    Allahverdyan, Armen E.; Galstyan, Aram

    2011-01-01

    The Le Chatelier principle states that physical equilibria are not only stable, but they also resist external perturbations via short-time negative-feedback mechanisms: a perturbation induces processes tending to diminish its results. The principle has deep roots, e.g., in thermodynamics it is closely related to the second law and the positivity of the entropy production. Here we study the applicability of the Le Chatelier principle to evolutionary game theory, i.e., to perturbations of a Nas...

  9. Magic Physics?

    Science.gov (United States)

    Featonby, David

    2010-01-01

    This article examines several readily available "magic tricks" which base their "trickery" on physics principles, and questions the use of the word "magic" in the 21st century, both in popular children's science and in everyday language. (Contains 18 figures.)

  10. PHYSICS

    CERN Multimedia

    V.Ciulli

    2011-01-01

    The main programme of the Physics Week held between 16th and 20th May was a series of topology-oriented workshops on di-leptons, di-photons, inclusive W, and all-hadronic final states. The goal of these workshops was to reach a common understanding for the set of objects (ID, cleaning...), the handling of pile-up, calibration, efficiency and purity determination, as well as to revisit critical common issues such as the trigger. Di-lepton workshop Most analysis groups use a di-lepton trigger or a combination of single and di-lepton triggers in 2011. Some groups need to collect leptons with as low PT as possible with strong isolation and identification requirements as for Higgs into WW at low mass, others with intermediate PT values as in Drell-Yan studies, or high PT as in the Exotica group. Electron and muon reconstruction, identification and isolation, was extensively described in the workshop. For electrons, VBTF selection cuts for low PT and HEEP cuts for high PT were discussed, as well as more complex d...

  11. Hooke's Law: Applications of a Recurring Principle

    Science.gov (United States)

    Giuliodori, Mauricio J.; Lujan, Heidi L.; Briggs, Whitney S.; Palani, Gurunanthan; DiCarlo, Stephen E.

    2009-01-01

    Students generally approach topics in physiology as a series of unrelated phenomena that share few underlying principles. However, if students recognized that the same underlying principles can be used to explain many physiological phenomena, they may gain a more unified understanding of physiological systems. To address this concern, we…

  12. Climate Twins - a tool to explore future climate impacts by assessing real world conditions: Exploration principles, underlying data, similarity conditions and uncertainty ranges

    Science.gov (United States)

    Loibl, Wolfgang; Peters-Anders, Jan; Züger, Johann

    2010-05-01

    To achieve public awareness and thorough understanding about expected climate changes and their future implications, ways have to be found to communicate model outputs to the public in a scientifically sound and easily understandable way. The newly developed Climate Twins tool tries to fulfil these requirements via an intuitively usable web application, which compares spatial patterns of current climate with future climate patterns, derived from regional climate model results. To get a picture of the implications of future climate in an area of interest, users may click on a certain location within an interactive map with underlying future climate information. A second map depicts the matching Climate Twin areas according to current climate conditions. In this way scientific output can be communicated to the public which allows for experiencing climate change through comparison with well-known real world conditions. To identify climatic coincidence seems to be a simple exercise, but the accuracy and applicability of the similarity identification depends very much on the selection of climate indicators, similarity conditions and uncertainty ranges. Too many indicators representing various climate characteristics and too narrow uncertainty ranges will judge little or no area as regions with similar climate, while too little indicators and too wide uncertainty ranges will address too large regions as those with similar climate which may not be correct. Similarity cannot be just explored by comparing mean values or by calculating correlation coefficients. As climate change triggers an alteration of various indicators, like maxima, minima, variation magnitude, frequency of extreme events etc., the identification of appropriate similarity conditions is a crucial question to be solved. For Climate Twins identification, it is necessary to find a right balance of indicators, similarity conditions and uncertainty ranges, unless the results will be too vague conducting a

  13. The quantum beat principles and applications of atomic clocks

    CERN Document Server

    Major, F

    2007-01-01

    This work attempts to convey a broad understanding of the physical principles underlying the workings of these quantum-based atomic clocks, with introductory chapters placing them in context with the early development of mechanical clocks and the introduction of electronic time-keeping as embodied in the quartz-controlled clocks. While the book makes no pretense at being a history of atomic clocks, it nevertheless takes a historical perspective in its treatment of the subject. Intended for nonspecialists with some knowledge of physics or engineering, The Quantum Beat covers a wide range of salient topics relevant to atomic clocks, treated in a broad intuitive manner with a minimum of mathematical formalism. Detailed descriptions are given of the design principles of the rubidium, cesium, hydrogen maser, and mercury ion standards; the revolutionary changes that the advent of the laser has made possible, such as laser cooling, optical pumping, the formation of "optical molasses," and the cesium "fountain" stand...

  14. First principle study on the electronic properties and Schottky contact of graphene adsorbed on MoS2 monolayer under applied out-plane strain

    Science.gov (United States)

    Phuc, Huynh V.; Hieu, Nguyen N.; Hoi, Bui D.; Phuong, Le T. T.; Nguyen, Chuong V.

    2018-02-01

    In the present work, electronic properties and Schottky contact of graphene adsorbed on the MoS2 monolayer under applied out-plane strain are studied using density functional theory calculations. Our calculations show that weak van derpp Waals interactions between graphene and monolayer MoS2 are dominated at the interlayer distance of 3.34 Å and the binding energy per C atom of - 25.1 meV. A narrow band gap of 3.6 meV has opened in G/MoS2 heterointerface, and it can be modulated by the out-plane strain. Furthermore, the Schottky barrier and Schottky contact types in the G/MoS2 heterointerface can be controlled by the out-plane strain. At the equilibrium state (d = 3.34 Å), the intrinsic electronic structure of G/MoS2 heterointerface is well preserved and forms an n-type Schottky barrier of 0.49 eV. When the interlayer distance decreases, the transition from n-type to p-type Schottky contact occurs at d = 2.74 Å. Our studies promote the application of ultrathin G/MoS2 heterointerface in the next-generation nanoelectronic and photonic devices such as van-der-Waals-based field effect transistors.

  15. Band gap modulation of mono and bi-layer hexagonal ZnS under transverse electric field and bi-axial strain: A first principles study

    Science.gov (United States)

    Rai, D. P.; Kaur, Sumandeep; Srivastava, Sunita

    2018-02-01

    Density functional theory has been employed to study the electronic and mechanical properties of the monolayer and bilayer ZnS. AB stacked ZnS bilayer is found to be energetically more favorable over the AA stacked ZnS bilayer. The electronic bandgap decreases on moving from monolayer to bilayer. Application of positive transverse electric field in AA/AB stacked bilayers leads to a semiconductor to metal transition at 1.10 V/Å. Reversed polarity of electric field, on the other hand, leads to an asymmetric behavior of the bandgap for AB stacking while the behavior of the bandgap in AA stacking is polarity independent. The strong dependency of bandgap on polarity of electric field in AB stacked ZnS bilayer is due to the balancing of external field with the induced internal field which arises due the electronegativity and heterogeneity in the arrangements of atoms. The electronic structure varies with the variation of applied biaxial strain (compression/tensile). We report an increase in band gap in both single and double layers under compression up to -8.0%, which can be attributed to greater superposition of atomic orbitals (Zn-d and S-p hybridization). We expect that our results may stimulate more theoretical and experimental work on hexagonal multi-layers of ZnS employing external field (temperature, pressure, field etc.) for future applications of our present work.

  16. BNNTs under the influence of external electric field as potential new drug delivery vehicle of Glu, Lys, Gly and Ser amino acids: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Farmanzadeh, Davood, E-mail: d.farmanzad@umz.ac.ir; Ghazanfary, Samereh

    2014-11-30

    Graphical abstract: - Highlights: • Solvation energies show that the BNNTs/amino acids complex stabilizes in presence of solvent. • The adsorption process is sensitive to the external electric field. • The electric field is a suitable method for adsorption and storage of amino acids on BNNTs. - Abstract: The interaction of Glu (Glutamic acid), Lys (Lysine), Gly (Glycine) and Ser (Serine) amino acids with different polarities and (9, 0) zigzag single-wall boron nitride nanotubes (BNNTs) with various lengths in the presence and absence of external electric field (EF) in gas and solvent phases, are studied using density functional theory. It is found that interaction of Glu, Lys, Gly and Ser amino acids with BNNTs in both phases is energetically favorable. From solvation energy calculations, it can be seen that the BNNTs/amino acid complex dissolution in water is spontaneous. The adsorption energies and quantum molecular descriptors changed in the presence of external EF. Therefore, the study of BNNTs/amino acid complex under influence of external electric field is very important in proposing or designing new drug delivery systems in the presence of external EF. Results indicate that Glu, Lys, Gly and Ser amino acids can be adsorbed considerably on the BNNTs in the existence of external electric field. Our results showed that the BNNTs can act as a suitable drug delivery vehicle of Glu, Lys, Gly and Ser amino acids within biological systems and strength of adsorption and rate of drug release can be controlled by the external EF.

  17. BNNTs under the influence of external electric field as potential new drug delivery vehicle of Glu, Lys, Gly and Ser amino acids: A first-principles study

    International Nuclear Information System (INIS)

    Farmanzadeh, Davood; Ghazanfary, Samereh

    2014-01-01

    Graphical abstract: - Highlights: • Solvation energies show that the BNNTs/amino acids complex stabilizes in presence of solvent. • The adsorption process is sensitive to the external electric field. • The electric field is a suitable method for adsorption and storage of amino acids on BNNTs. - Abstract: The interaction of Glu (Glutamic acid), Lys (Lysine), Gly (Glycine) and Ser (Serine) amino acids with different polarities and (9, 0) zigzag single-wall boron nitride nanotubes (BNNTs) with various lengths in the presence and absence of external electric field (EF) in gas and solvent phases, are studied using density functional theory. It is found that interaction of Glu, Lys, Gly and Ser amino acids with BNNTs in both phases is energetically favorable. From solvation energy calculations, it can be seen that the BNNTs/amino acid complex dissolution in water is spontaneous. The adsorption energies and quantum molecular descriptors changed in the presence of external EF. Therefore, the study of BNNTs/amino acid complex under influence of external electric field is very important in proposing or designing new drug delivery systems in the presence of external EF. Results indicate that Glu, Lys, Gly and Ser amino acids can be adsorbed considerably on the BNNTs in the existence of external electric field. Our results showed that the BNNTs can act as a suitable drug delivery vehicle of Glu, Lys, Gly and Ser amino acids within biological systems and strength of adsorption and rate of drug release can be controlled by the external EF

  18. Nonlinear Optics: Principles and Applications

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Tidemand-Lichtenberg, Peter

    As nonlinear optics further develops as a field of research in electromagnetic wave propagation, its state-of-the-art technologies will continue to strongly impact real-world applications in a variety of fields useful to the practicing scientist and engineer. From basic principles to examples...... of applications, Nonlinear Optics: Principles and Applications effectively bridges physics and mathematics with relevant applied material for real-world use. The book progresses naturally from fundamental aspects to illustrative examples, and presents a strong theoretical foundation that equips the reader...

  19. Microscopic Description of Le Chatelier's Principle

    Science.gov (United States)

    Novak, Igor

    2005-01-01

    A simple approach that "demystifies" Le Chatelier's principle (LCP) and simulates students to think about fundamental physical background behind the well-known principles is presented. The approach uses microscopic descriptors of matter like energy levels and populations and does not require any assumption about the fixed amount of substance being…

  20. Coordinated Scheme of Under-Frequency Load Shedding with Intelligent Appliances in a Cyber Physical Power System

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2016-08-01

    Full Text Available The construction of a cyber physical system in a power grid provides more potential control strategies for the power grid. With the rapid employment of intelligent terminal equipment (e.g., smart meters and intelligent appliances in the environment of a smart grid, abundant dynamic response information could be introduced to support a secure and stable power system. Combining demand response technology with the traditional under-frequency load shedding (UFLS scheme, a new UFLS strategy-determining method involving intelligent appliances is put forward to achieve the coordinated control of quick response resources and the traditional control resources. Based on this method, intelligent appliances can be used to meet the regulatory requirements of system operation in advance and prevent significant frequency drop, thereby improving the flexibility and stability of the system. Time-domain simulation verifies the effectiveness of the scheme, which is able to mitigate frequency drop and reduce the amount of load shedding.

  1. SOIL PHYSICAL ATTRIBUTES AND YIELD OF WINTER COMMON BEAN CROP UNDER A NO-TILL SYSTEM IN THE BRAZILIAN CERRADO

    Directory of Open Access Journals (Sweden)

    MARIA CECÍLIA CAVALLINI DA SILVA

    2017-01-01

    Full Text Available Knowledge of the interactions between soil physical properties and yield performance in agricultural crops is very important for the adoption of appropriate management practices. This study aimed to evaluate the linear and spatial correlations between some soil physical attributes, straw production in the palisade grass (Urochloa brizantha, and grain yield of winter common bean in succession to the grass under an irrigated no-till system in an Oxisol Haplorthox in the Cerrado lowlands region of Brazil. The plant attributes determined were dry matter yield of U. brizantha (DMY, and grain yield (GY and final plant population (PP of winter common bean. The soil physical attributes, evaluated at 0.0-0.10 m and 0.10-0.20 m, were soil bulk density (BD, macroporosity (MA, microporosity (MI, total porosity (TP, penetration resistance (PR, gravimetric water content (GW, and volumetric water content (VW. A geostatistical grid with 124 sampling points was installed to collect the soil and plant data in an area of 4000 m2. The remaining straw amount of palisade grass exhibited an inverse linear correlation with bean yield and bean plant population when the bean was cultivated in succession. However, no spatial correlations were observed among the attributes. The common bean yield had a direct linear correlation with gravimetric water content in the 0.10-0.20 m soil layer. From a spatial point of view, winter bean yield showed a strong dependence on the distribution of the volumetric water content in the 0-0.10 m soil layer.

  2. Phase stability, physical properties of rhenium diboride under high pressure and the effect of metallic bonding on its hardness

    International Nuclear Information System (INIS)

    Zhong, Ming-Min; Kuang, Xiao-Yu; Wang, Zhen-Hua; Shao, Peng; Ding, Li-Ping; Huang, Xiao-Fen

    2013-01-01

    Highlights: •The transition pressure P t between the ReB 2 –ReB 2 and MoB 2 –ReB 2 phases is firstly determinate. •The single-bonded B–B feather remains in ReB 2 compounds. •A semiempirical method to evaluate the hardness of crystals with partial metallic bond is presented. •The large hardness (39.1 GPa) of ReB 2 –ReB 2 indicate that it is a superhard material. •The zigzag interconnected B–Re and B–B covalent bonds underlie the ultraincompressibilities. -- Abstract: Using first-principles calculations, the elastic constants, thermodynamic property and structural phase transition of rhenium diboride under pressure are investigated by means of the pseudopotential plane-waves method, as well as the effect of metallic bond on its hardness. Eight candidate structures of known transition-metal compounds are chosen to probe for rhenium diboride ReB 2 . The calculated lattice parameters are consistent with the experimental and theoretical values. Based on the third order Birch–Murnaghan equation of states, the transition pressure P t between the ReB 2 –ReB 2 and MoB 2 –ReB 2 phases is firstly determinate. Elastic constants, shear modulus, Young’s modulus, Poisson’s ratio and Debye temperature are derived. The single-bonded B–B feather remains in ReB 2 compounds. Furthermore, according to Mulliken overlap population analysis, a semiempirical method to evaluate the hardness of multicomponent crystals with partial metallic bond is presented. Both strong covalency and a zigzag topology of interconnected bonds underlie the ultraincompressibilities. In addition, the superior performance and large hardness (39.1 GPa) of ReB 2 –ReB 2 indicate that it is a superhard material

  3. The 4th Thermodynamic Principle?

    International Nuclear Information System (INIS)

    Montero Garcia, Jose de la Luz; Novoa Blanco, Jesus Francisco

    2007-01-01

    It should be emphasized that the 4th Principle above formulated is a thermodynamic principle and, at the same time, is mechanical-quantum and relativist, as it should inevitably be and its absence has been one of main the theoretical limitations of the physical theory until today.We show that the theoretical discovery of Dimensional Primitive Octet of Matter, the 4th Thermodynamic Principle, the Quantum Hexet of Matter, the Global Hexagonal Subsystem of Fundamental Constants of Energy and the Measurement or Connected Global Scale or Universal Existential Interval of the Matter is that it is possible to be arrived at a global formulation of the four 'forces' or fundamental interactions of nature. The Einstein's golden dream is possible

  4. Wheat yield and physical properties of a brown latosol under no-tillage in south-central Paraná

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Machado Kramer

    2013-10-01

    Full Text Available Soil management influences the chemical and physical properties of soil. Chemical conditions have been thoroughly studied, while the role of soil physical conditions regarding crop yield has been neglected. This study aimed to analyze the wheat yield and its relationship with physical properties of an Oxisol under no-tillage (NT. The study was carried out between 2010 and 2011, in Reserva do Iguaçu, State of Paraná, Brazil, on the Campo Bonito farm, after 25 years of NT management. Based on harvest maps of barley (2006, wheat (2007 and maize (2009 of a plot (150 ha, zones with higher and lower yield potential (Z1 and Z2, respectively were identified. Sampling grids with 16 units (50 x 50 m and three sampling points per unit were established. The wheat grain yield (GY and water infiltration capacity (WIC were evaluated in 2010. Soil samples with disturbed and undisturbed structure were collected from the 0.00-0.10 and 0.10-0.20 m layers. The former were used to determine soil organic carbon (Corg levels and the latter to determine soil bulk density (BD, total porosity (TP, macroporosity (Mac, and microporosity (Mic. Soil penetration resistance (PR and water content (SWC were also evaluated. The wheat GY of the whole plot was close to the regional average and the yield between the zones differed significantly, i.e. 22 % higher in Z1 than in Z2. No significant variation in Mic was observed between zones, but Z1 had higher Corg levels, SWC, TP and Mac and lower BD than Z2 in both soil layers, as well as a lower PR than Z2 in the 0.00-0.10 m layer. Therefore, soil physical conditions were more restrictive in Z2, in agreement with wheat yield and zone yield potential defined a priori, based on the harvest maps. Soil WIC in Z1 was significantly higher (30 % than in Z2, in agreement with the results of TP and Mac which were also higher in Z1 in both soil layers. The correlation analysis of data of the two layers showed a positive relationship between

  5. Developmental Principles: Fact or Fiction

    Directory of Open Access Journals (Sweden)

    A. J. Durston

    2012-01-01

    Full Text Available While still at school, most of us are deeply impressed by the underlying principles that so beautifully explain why the chemical elements are ordered as they are in the periodic table, and may wonder, with the theoretician Brian Goodwin, “whether there might be equally powerful principles that account for the awe-inspiring diversity of body forms in the living realm”. We have considered the arguments for developmental principles, conclude that they do exist and have specifically identified features that may generate principles associated with Hox patterning of the main body axis in bilaterian metazoa in general and in the vertebrates in particular. We wonder whether this exercise serves any purpose. The features we discuss were already known to us as parts of developmental mechanisms and defining developmental principles (how, and at which level? adds no insight. We also see little profit in the proposal by Goodwin that there are principles outside the emerging genetic mechanisms that need to be taken into account. The emerging developmental genetic hierarchies already reveal a wealth of interesting phenomena, whatever we choose to call them.

  6. The common European flexicurity principles

    DEFF Research Database (Denmark)

    Mailand, Mikkel

    2010-01-01

    This article analyses the decision-making process underlying the adoption of common EU flexicurity principles. Supporters of the initiative succeeded in convincing the sceptics one by one; the change of government in France and the last-minute support of the European social partner organizations...

  7. The general principles of quantum theory

    CERN Document Server

    Temple, George

    2014-01-01

    Published in 1934, this monograph was one of the first introductory accounts of the principles which form the physical basis of the Quantum Theory, considered as a branch of mathematics. The exposition is restricted to a discussion of general principles and does not attempt detailed application to the wide domain of atomic physics, although a number of special problems are considered in elucidation of the principles. The necessary fundamental mathematical methods - the theory of linear operators and of matrics - are developed in the first chapter so this could introduce anyone to the new theor

  8. Frontier of physics with strange particles

    International Nuclear Information System (INIS)

    Yamazaki, T.

    1985-01-01

    I deliver my own perspectives on possible domains of physics underlying between particle physics and nuclear physics, which can be studied by using strange particles produced abundantly by the KEK 12 GeV proton synchrotron. My guiding principle on the scientific program at KEK (National Laboratory for High Energy Physics) is to promote experiments of brand new type and thus to create something new. Unfortunately, particle physics and nuclear physics seem to have been separated too much, but in such a playground as the KEK PS, these two aspects of physics can well be coupled to each other. Namely, particle physics provides new type of probes to nuclear physics, while nuclei provide abnormal external conditions to particles. Contents are the following: search for exotic particles in K + decay, right-handed sector, new aspects in nuclear physics, new type of hypernuclear spectroscopy, promising future at KEK. (Mori, K.)

  9. Saccharomyces genome database: underlying principles and organisation.

    Science.gov (United States)

    Dwight, Selina S; Balakrishnan, Rama; Christie, Karen R; Costanzo, Maria C; Dolinski, Kara; Engel, Stacia R; Feierbach, Becket; Fisk, Dianna G; Hirschman, Jodi; Hong, Eurie L; Issel-Tarver, Laurie; Nash, Robert S; Sethuraman, Anand; Starr, Barry; Theesfeld, Chandra L; Andrada, Rey; Binkley, Gail; Dong, Qing; Lane, Christopher; Schroeder, Mark; Weng, Shuai; Botstein, David; Cherry, J Michael

    2004-03-01

    A scientific database can be a powerful tool for biologists in an era where large-scale genomic analysis, combined with smaller-scale scientific results, provides new insights into the roles of genes and their products in the cell. However, the collection and assimilation of data is, in itself, not enough to make a database useful. The data must be incorporated into the database and presented to the user in an intuitive and biologically significant manner. Most importantly, this presentation must be driven by the user's point of view; that is, from a biological perspective. The success of a scientific database can therefore be measured by the response of its users - statistically, by usage numbers and, in a less quantifiable way, by its relationship with the community it serves and its ability to serve as a model for similar projects. Since its inception ten years ago, the Saccharomyces Genome Database (SGD) has seen a dramatic increase in its usage, has developed and maintained a positive working relationship with the yeast research community, and has served as a template for at least one other database. The success of SGD, as measured by these criteria, is due in large part to philosophies that have guided its mission and organisation since it was established in 1993. This paper aims to detail these philosophies and how they shape the organisation and presentation of the database.

  10. Integrating Principles Underlying Ancestral Spirits Belief in ...

    African Journals Online (AJOL)

    , associated with ancestral spirits and its use as powerful therapeutic agent for influencing behavior or lifestyle changes. Explanatory models of attachment to ancestral spirits by living descendants are first discussed, followed by a discussion ...

  11. The quantum gauge principle

    CERN Document Server

    Graudenz, Dirk

    1996-01-01

    We consider the evolution of quantum fields on a classical background space-time, formulated in the language of differential geometry. Time evolution along the worldlines of observers is described by parallel transport operators in an infinite-dimensional vector bundle over the space-time manifold. The time evolution equation and the dynamical equations for the matter fields are invariant under an arbitrary local change of frames along the restriction of the bundle to the worldline of an observer, thus implementing a ``quantum gauge principle''. We derive dynamical equations for the connection and a complex scalar quantum field based on a gauge field action. In the limit of vanishing curvature of the vector bundle, we recover the standard equation of motion of a scalar field in a curved background space-time.

  12. Physical quality of an Oxisol under an integrated crop-livestock-forest system in the Brazilian Cerrado

    Directory of Open Access Journals (Sweden)

    Eurico Lucas de Sousa Neto

    2014-04-01

    Full Text Available Soil physical quality is an important factor for the sustainability of agricultural systems. Thus, the aim of this study was to evaluate soil physical properties and soil organic carbon in a Typic Acrudox under an integrated crop-livestock-forest system. The experiment was carried out in Mato Grosso do Sul, Brazil. Treatments consisted of seven systems: integrated crop-livestock-forest, with 357 trees ha-1 and pasture height of 30 cm (CLF357-30; integrated crop-livestock-forest with 357 trees ha-1 and pasture height of 45 cm (CLF357-45; integrated crop-livestock-forest with 227 trees ha-1 and pasture height of 30 cm (CLF227-30; integrated crop-livestock-forest with 227 trees ha-1 and pasture height of 45 cm (CLF227-45; integrated crop-livestock with pasture height of 30 cm (CL30; integrated crop-livestock with pasture height of 45 cm (CL45 and native vegetation (NV. Soil properties were evaluated for the depths of 0-10 and 10-20 cm. All grazing treatments increased bulk density (r b and penetration resistance (PR, and decreased total porosity (¦t and macroporosity (¦ma, compared to NV. The values of r b (1.18-1.47 Mg m-3, ¦ma (0.14-0.17 m³ m-3 and PR (0.62-0.81 MPa at the 0-10 cm depth were not restrictive to plant growth. The change in land use from NV to CL or CLF decreased soil organic carbon (SOC and the soil organic carbon pool (SOCpool. All grazing treatments had a similar SOCpool at the 0-10 cm depth and were lower than that for NV (17.58 Mg ha-1.

  13. Principle and use of dosemeters

    International Nuclear Information System (INIS)

    Genet, S.; Ribaud, I.

    1997-01-01

    The institute of nuclear physics of Orsay is accepted by the Ministry of Labour to insure the surveillance of workers individual external exposure against the danger of ionizing radiations and to execute monitoring of radiation protection. The dosemeters studied in this report are the photographic film dosemeters ( for x rays, gamma rays and beta - rays), the trace detectors (fast neutrons) and the radio thermo luminescent dosemeters. For each type, the principle and how to use it are given. (N.C.)

  14. Principles of digital image synthesis

    CERN Document Server

    Glassner, Andrew S

    1995-01-01

    Image synthesis, or rendering, is a field of transformation: it changesgeometry and physics into meaningful images. Because the most popularalgorithms frequently change, it is increasingly important for researchersand implementors to have a basic understanding of the principles of imagesynthesis. Focusing on theory, Andrew Glassner provides a comprehensiveexplanation of the three core fields of study that come together to formdigital image synthesis: the human visual system, digital signalprocessing, and the interaction of matter and light. Assuming no more thana basic background in calculus,

  15. Flawed Applications of Bernoulli's Principle

    Science.gov (United States)

    Koumaras, Panagiotis; Primerakis, Georgios

    2018-04-01

    One of the most popular demonstration experiments pertaining to Bernoulli's principle is the production of a water spray by using a vertical plastic straw immersed in a glass of water and a horizontal straw to blow air towards the top edge of the vertical one. A more general version of this phenomenon, appearing also in school physics problems, is the determination of the rise of the water level h in the straw (see Fig. 1).

  16. Variability of Some soil physical and chemical properties along a transect under wind erosion processes in Segzi district, Isfahan

    Directory of Open Access Journals (Sweden)

    F. Ghiesari

    2016-10-01

    reduced significantly In eroded sites compared to reference site. Similarly, clay content was reduced in the eroded sites compared to depositional sites. But,the amount of gypsum and calcium carbonate equivalent increased in eroded sites. Bulk density significantly declined in eroded (23.95% and depositional (33.33% sites comparing to reference site. Silt and sand content significantly were increased and decreased in depositional sites respectively compared to reference site. High speed winds caused to translocate the fine and coarser particles to farther and closer distances from detachment locations. Therefore, soil texture was mainly affected by soil erosion and changed to coarser classes. Compare means between physical and chemical properties in the eroded and deposited sites and reference site showed that physical and chemical properties were affected by erosion and deposition processes significantly. Conclusion: Overall results indicated that Cs-137 is powerful technique for differentiation between erosional and depositional sites in the regions under wind erosion. Moreover, the this study confirmed that eroded and depositional sites wrer significantly affected by wind erosion process and soil attributes were changed compared to reference site. and proper management, especially in gypsum mines of Segzi district should be considered .

  17. Using Gambling to Teach Insurance Principles

    OpenAIRE

    Mark Pingle

    2010-01-01

    A basic understanding of insurance principles is useful for making personal finance decisions and for considering public policy issues. Yet, insurance concepts tend to be less intuitive, more difficult for students to grasp, than other concepts. This paper shows how fundamental insurance principles can be taught by relating them to the principles underlying gambling, the game of roulette in particular. This approach has been used successfully with college freshmen taking macroeconomics at the...

  18. Three principles of competitive nonlinear pricing

    OpenAIRE

    Frank H. Page; Paulo Klinger Monteiro

    2002-01-01

    We make three contributions to the theory of contracting under asymmetric information. First , we establish a competitive analog to the revelation principle which we call the implementation principle. This principle provides a complete characterization of all incentive compatible, indirect contracting mechanisms in terms of contract catalogs (or menus), and allows us to conclude that in competitive contracting situations, firms in choosing their contracting strategies can restrict attention, ...

  19. Quantum Physics Illusion or Reality?

    CERN Document Server

    Rae, Alastair I M

    2004-01-01

    Quantum physics is believed to be the fundamental theory underlying our understanding of the physical universe. However, it is based on concepts and principles that have always been difficult to understand and controversial in their interpretation. This book aims to explain these issues using a minimum of technical language and mathematics. After a brief introduction to the ideas of quantum physics, the problems of interpretation are identified and explained. The rest of the book surveys, describes and criticises a range of suggestions that have been made with the aim of resolving these proble

  20. Principles of project management

    Science.gov (United States)

    1982-01-01

    The basic principles of project management as practiced by NASA management personnel are presented. These principles are given as ground rules and guidelines to be used in the performance of research, development, construction or operational assignments.

  1. Short term recovery of soil physical, chemical, micro- and mesobiological functions in a new vineyard under organic farming

    Science.gov (United States)

    Costantini, E. A. C.; Agnelli, A. E.; Fabiani, A.; Gagnarli, E.; Mocali, S.; Priori, S.; Simoni, S.; Valboa, G.

    2014-12-01

    Deep earthwork activities carried out before vineyard plantation can severely upset soil profile properties. As a result, soil features in the root environment are often much more similar to those of the underlying substratum than those of the original profile. The time needed to recover the original soil functions is ecologically relevant and may strongly affect vine phenology and grape yield, particularly under organic viticulture. The general aim of this work was to investigate soil resilience after vineyard pre-planting earthworks. In particular, an old and a new vineyard, established on the same soil type, were compared over a five year period for soil chemical, physical, micro and mesobiological properties. The investigated vineyards (Vitis vinifera L., cv. Sangiovese) were located in the Chianti Classico district (Central Italy), on stony and calcareous soils and were not irrigated. The older vineyard was planted in 2000, after slope reshaping by bulldozing and back hoe ploughing down to about 0.8-1.0 m. The new vineyard was planted in 2011, after equivalent earthwork practices carried out in the summer of 2009. Both vineyards were organically managed and fertilized only with compost every autumn (1000 kg ha-1 per year). The new vineyard was cultivated by periodic tillage, while the old vineyard was managed with alternating grass-covered and tilled inter-rows. Soil samples were collected at 0-15 cm depth from the same plots of the new and old vineyards, during the springtime from 2010 to 2014. The old vineyard was sampled in both the tilled and the grass-covered swaths. According to the results from physical and chemical analyses, the new vineyard, during the whole 2010-2014 period, showed lower TOC, N, C/N and EC values, along with higher silt and total CaCO3 contents than the old vineyard, suggesting still evolving equilibrium conditions. The microarthropod analysis showed significantly different abundances and communities' structures, in relation to both

  2. Impact of Amendments on the Physical Properties of Soil under Tropical Long-Term No Till Conditions.

    Directory of Open Access Journals (Sweden)

    Antonio C A Carmeis Filho

    Full Text Available Tropical regions have been considered the world's primary agricultural frontier; however, some physico-chemical deficiencies, such as low soil organic matter content, poor soil structure, high erodibility, soil acidity, and aluminum toxicity, have affected their productive capacity. Lime and gypsum are commonly used to improve soil chemical fertility, but no information exists about the long-term effects of these products on the physical attributes and C protection mechanisms of highly weathered Oxisols. A field trial was conducted in a sandy clay loam (kaolinitic, thermic Typic Haplorthox under a no-tillage system for 12 years. The trial consisted of four treatments: a control with no soil amendment application, the application of 2.1 Mg ha-1 phosphogypsum, the application of 2.0 Mg ha-1 lime, and the application of lime + phosphogypsum (2.0 + 2.1 Mg ha-1, respectively. Since the experiment was established in 2002, the rates have been applied three times (2002, 2004, and 2010. Surface liming effectively increased water-stable aggregates > 2.0 mm at a depth of up to 0.2 m; however, the association with phosphogypsum was considered a good strategy to improve the macroaggregate stability in subsoil layers (0.20 to 0.40 m. Consequently, both soil amendments applied together increased the mean weight diameter (MWD and geometric mean diameter (GMD in all soil layers, with increases of up to 118 and 89%, respectively, according to the soil layer. The formation and stabilization of larger aggregates contributed to a higher accumulation of total organic carbon (TOC on these structures. In addition to TOC, the MWD and aggregate stability index were positively correlated with Ca2+ and Mg2+ levels and base saturation. Consequently, the increase observed in the aggregate size class resulted in a better organization of soil particles, increasing the macroporosity and reducing the soil bulk density and penetration resistance. Therefore, adequate soil chemical

  3. Fiber optics principles and practices

    CERN Document Server

    Al-Azzawi, Abdul

    2007-01-01

    Since the invention of the laser, our fascination with the photon has led to one of the most dynamic and rapidly growing fields of technology. New advances in fiber optic devices, components, and materials make it more important than ever to stay current. Comprising chapters drawn from the author's highly anticipated book Photonics: Principles and Practices, Fiber Optics: Principles and Practices offers a detailed and focused treatment for anyone in need of authoritative information on this critical area underlying photonics.Using a consistent approach, the author leads you step-by-step throug

  4. Principles and applications of tribology

    CERN Document Server

    Moore, Desmond F

    1975-01-01

    Principles and Applications of Tribology provides a mechanical engineering perspective of the fundamental understanding and applications of tribology. This book is organized into two parts encompassing 16 chapters that cover the principles of friction and different types of lubrication. Chapter 1 deals with the immense scope of tribology and the range of applications in the existing technology, and Chapter 2 is devoted entirely to the evaluation and measurement of surface texture. Chapters 3 to 5 present the fundamental concepts underlying the friction of metals, elastomers, and other material

  5. Dynamical principles in neuroscience

    International Nuclear Information System (INIS)

    Rabinovich, Mikhail I.; Varona, Pablo; Selverston, Allen I.; Abarbanel, Henry D. I.

    2006-01-01

    Dynamical modeling of neural systems and brain functions has a history of success over the last half century. This includes, for example, the explanation and prediction of some features of neural rhythmic behaviors. Many interesting dynamical models of learning and memory based on physiological experiments have been suggested over the last two decades. Dynamical models even of consciousness now exist. Usually these models and results are based on traditional approaches and paradigms of nonlinear dynamics including dynamical chaos. Neural systems are, however, an unusual subject for nonlinear dynamics for several reasons: (i) Even the simplest neural network, with only a few neurons and synaptic connections, has an enormous number of variables and control parameters. These make neural systems adaptive and flexible, and are critical to their biological function. (ii) In contrast to traditional physical systems described by well-known basic principles, first principles governing the dynamics of neural systems are unknown. (iii) Many different neural systems exhibit similar dynamics despite having different architectures and different levels of complexity. (iv) The network architecture and connection strengths are usually not known in detail and therefore the dynamical analysis must, in some sense, be probabilistic. (v) Since nervous systems are able to organize behavior based on sensory inputs, the dynamical modeling of these systems has to explain the transformation of temporal information into combinatorial or combinatorial-temporal codes, and vice versa, for memory and recognition. In this review these problems are discussed in the context of addressing the stimulating questions: What can neuroscience learn from nonlinear dynamics, and what can nonlinear dynamics learn from neuroscience?

  6. Modeling Electric Discharges with Entropy Production Rate Principles

    Directory of Open Access Journals (Sweden)

    Thomas Christen

    2009-12-01

    Full Text Available Under which circumstances are variational principles based on entropy production rate useful tools for modeling steady states of electric (gas discharge systems far from equilibrium? It is first shown how various different approaches, as Steenbeck’s minimum voltage and Prigogine’s minimum entropy production rate principles are related to the maximum entropy production rate principle (MEPP. Secondly, three typical examples are discussed, which provide a certain insight in the structure of the models that are candidates for MEPP application. It is then thirdly argued that MEPP, although not being an exact physical law, may provide reasonable model parameter estimates, provided the constraints contain the relevant (nonlinear physical effects and the parameters to be determined are related to disregarded weak constraints that affect mainly global entropy production. Finally, it is additionally conjectured that a further reason for the success of MEPP in certain far from equilibrium systems might be based on a hidden linearity of the underlying kinetic equation(s.

  7. 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.

  8. Biochar may physically entrap nitrate during field aging or co-composting which become plant available under controlled conditions

    Science.gov (United States)

    Haider, Ghulam; Steffens, Diedrich; Müller, Christoph; Kammann, Claudia

    2017-04-01

    Conversion of organic biomass (agriculture/forestry residues) to biochar (BC) for carbon sequestration in soil to abate global warming has received much attention in recent years. However, apart from carbon sequestration, the incorporation of freshly produced biochars in agricultural soils have shown varying effects on soil-plant-moisture and nutrient interactions. It has been frequently reported that BC amendment may accelerate soil N transformations, reduce nitrate leaching, increase nutrient availability and soil fertility thereby increase crop yields by 10-15%. In addition, recent meta-studies suggested that BC-nitrogen (N) interactions in agricultural soils have the potential to reduce nitrous oxide (N2O) emissions by 50% with the underlying mechanisms not well understood. Also, mechanisms of BC-N sorption and desorption or plant availability of captured N in BC remain poorly understood. In this study we conducted two different experiments aiming (a) to understand the mechanism of nitrate capture by field aged (>3 years) BC (wood chip, pruning, bark and leaves (550-600°C)) and (b) to test the availability of captured nitrate by field-aged and composted BC to plants (quinoa, ryegrass) in a pot study under controlled conditions. Experiment (A): We hypothesized that N captured in the pores of BC may remain inaccessible to extraction solutions due to clogging of BC pores by the development of hydrophobic layer on BC surface following oxidation under field conditions. Therefore (i) physically breaking the structure or (ii) exerting under-pressure to water-immersed aged BC particles may allow extracting greater nitrate with the standard 2 M KCl method compared to intact particles. Study (A) encompassed 1) extraction from intact field-aged BC particles, 2) extraction after immersion in water and evacuation in vacutainers, 3) extraction after grinding of BC to powder and 4) prolonged shaking (48 hours at 80°C) of intact field aged BC particles and then extraction

  9. [Effect of physical activity strength on the diabetes mellitus prevalence in the elderly under the influence of International Physical Activity Questionnaire].

    Science.gov (United States)

    Jiang, Chao-qiang; Xu, Lin; Lam, Tai-hing; Zhang, Wei-sen; Liu, Bin; Lin, Jie-ming; Yue, Xiao-jun; Jin, Ya-li; Thomas, G Neil

    2009-05-01

    To examine the impact of International Physical Activity Questionnaire (IPAQ) physical activity intensity on to the prevalence of diabetes mellitus among Chinese elderly. A total number of 1996 residents aged 50 or above living in Guangzhou city were recruited from the phase 3 of the Guangzhou Biobank Cohort Study. Information on physical activity and fasting plasma glucose status was derived from standardized interviews and laboratory assays. Among the participants who were classified as physically active (60.0%), moderate active (29.8%) and inactive (10.2%), the prevalence rates of type 2 diabetes mellitus were 9.1%, 12.0% and 14.2%, respectively. After adjustment on age, sex, obesity and other potential confounding factors, data from logistic regression model showed that the odds ratios (95% confidence interval) for diabetes on subjects in physically moderate active and active group were 0.75(0.46-1.26)and 0.60(0.38-0.97) respectively with P for trend as 0.03, when comparing to those physically inactive ones. Promotion of physical activity might have had some effects in reducing the risk of diabetes mellitus among the older adults.

  10. Physical, chemical, and biological properties of soil under soybean cultivation and at an adjacent rainforest in Amazonia

    Directory of Open Access Journals (Sweden)

    Troy Patrick Beldini

    2015-11-01

    Full Text Available Land-use change in the Amazon basin has occurred at an accelerated pace during the last decade, and it is important that the effects induced by these changes on soil properties are better understood. This study investigated the chemical, physical, and biological properties of soil in a field under cultivation of soy and rice, and at an adjacent primary rain forest. Increases in soil bulk density, exchangeable cations and pH were observed in the soy field soil. In the primary forest, soil microbial biomass and basal respiration rates were higher, and the microbial community was metabolically more efficient. The sum of basal respiration across the A, AB and BA horizons on a mass per area basis ranged from 7.31 to 10.05 Mg CO2-C ha-1yr-1, thus yielding estimates for total soil respiration between 9.6 and 15.5 Mg CO2-C ha-1yr-1 across sites and seasons. These estimates are in good agreement with literature values for Amazonian ecosystems. The estimates of heterotrophic respiration made in this study help to further constrain the estimates of autotrophic soil respiration and will be useful for monitoring the effects of future land-use in Amazonian ecosystems.

  11. LAMI - a planned Brazilian facility to investigate the mechanical and physical properties of structural materials under irradiation

    International Nuclear Information System (INIS)

    Andrade, Arnaldo H.P.; Lobo, Raquel M.

    2011-01-01

    The LAMI (Laboratorio de Materiais Irradiados) is a hot laboratory designed to the characterization of irradiated structural material and will constitute one of the main installations of the Brazilian Multipurpose Reactor (RMB). The strong points of LAMI are: to contribute, through theoretical and experimental investigations, to the development of knowledge in materials science in order to be able to predict the evolution of the physical and mechanical material properties under service conditions (irradiation, thermomechanical solicitation, influence of the environment, etc); to characterize the properties of the materials used in the nuclear industry in order to determine their performance and to be able to predict their life expectancy; to establish, maintain and make use of the database generated by these data and to provide expertise on industrial components, in particular to investigate strain or rupture mechanisms. The test materials can be irradiated or not, and originate from surveillance programs, experimental neutron irradiations or simulated irradiation with charged particles. The main line of LAMI will have 10 shielded hot cells. The building also will have an area dedicated to micro and nano structural materials analysis. The mechanical characterization to be carried out within LAMI includes mechanical tests on irradiated materials, comprehension of behavior and damage processes and the incorporation of the test data results in a data bank for capitalization of test results. Planned materials to be tested are going to be metallic alloys used in industrial and experimental reactor: pressure vessel steels, internal stainless steels, austeno-ferritic steels, zirconium alloys and aluminum alloys. (author)

  12. Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses.

    Science.gov (United States)

    Yoto, Ai; Motoki, Mao; Murao, Sato; Yokogoshi, Hidehiko

    2012-10-29

    L-theanine, an amino acid contained in green tea leaves, is known to block the binding of L-glutamic acid to glutamate receptors in the brain, and has been considered to cause anti-stress effects by inhibiting cortical neuron excitation. Both L-theanine and caffeine, which green tea contains, have been highlighted for their beneficial effects on cognition and mood. In this study, we investigated the effects of orally administered L-theanine or caffeine on mental task performance and physiological activities under conditions of physical or psychological stress in humans. Fourteen participants each underwent three separate trials, in which they orally took either L-theanine + placebo, caffeine + placebo, or placebo only. The results after the mental tasks showed that L-theanine significantly inhibited the blood-pressure increases in a high-response group, which consisted of participants whose blood pressure increased more than average by a performance of a mental task after placebo intake. Caffeine tended to have a similar but smaller inhibition of the blood-pressure increases caused by the mental tasks. The result of the Profile of Mood States after the mental tasks also showed that L-theanine reduced the Tension-Anxiety scores as compared with placebo intake. The findings above denote that L-theanine not only reduces anxiety but also attenuates the blood-pressure increase in high-stress-response adults.

  13. Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses

    Directory of Open Access Journals (Sweden)

    Yoto Ai

    2012-10-01

    Full Text Available Abstract Background L-theanine, an amino acid contained in green tea leaves, is known to block the binding of L-glutamic acid to glutamate receptors in the brain, and has been considered to cause anti-stress effects by inhibiting cortical neuron excitation. Both L-theanine and caffeine, which green tea contains, have been highlighted for their beneficial effects on cognition and mood. Methods In this study, we investigated the effects of orally administered L-theanine or caffeine on mental task performance and physiological activities under conditions of physical or psychological stress in humans. Fourteen participants each underwent three separate trials, in which they orally took either L-theanine + placebo, caffeine + placebo, or placebo only. Results The results after the mental tasks showed that L-theanine significantly inhibited the blood-pressure increases in a high-response group, which consisted of participants whose blood pressure increased more than average by a performance of a mental task after placebo intake. Caffeine tended to have a similar but smaller inhibition of the blood-pressure increases caused by the mental tasks. The result of the Profile of Mood States after the mental tasks also showed that L-theanine reduced the Tension-Anxiety scores as compared with placebo intake. Conclusions The findings above denote that L-theanine not only reduces anxiety but also attenuates the blood-pressure increase in high-stress-response adults.

  14. Physical assessment of coastal vulnerability under enhanced land subsidence in Semarang, Indonesia, using multi-sensor satellite data

    Science.gov (United States)

    Husnayaen; Rimba, A. Besse; Osawa, Takahiro; Parwata, I. Nyoman Sudi; As-syakur, Abd. Rahman; Kasim, Faizal; Astarini, Ida Ayu

    2018-04-01

    Research has been conducted in Semarang, Indonesia, to assess coastal vulnerability under enhanced land subsidence using multi-sensor satellite data, including the Advanced Land Observing Satellite (ALOS) Phased Array type L-band SAR (PALSAR), Landsat TM, IKONOS, and TOPEX/Poseidon. A coastal vulnerability index (CVI) was constructed to estimate the level of vulnerability of a coastline approximately 48.68 km in length using seven physical variables, namely, land subsidence, relative sea level change, coastal geomorphology, coastal slope, shoreline change, mean tidal range, and significant wave height. A comparison was also performed between a CVI calculated using seven parameters and a CVI using six parameters, the latter of which excludes the land subsidence parameter, to determine the effects of land subsidence during the coastal vulnerability assessment. This study showed that the accuracy of coastal vulnerability was increased 40% by adding the land subsidence factor (i.e., CVI 6 parameters = 53%, CVI 7 parameters = 93%). Moreover, Kappa coefficient indicated very good agreement (0.90) for CVI 7 parameters and fair agreement (0.3) for CVI 6 parameters. The results indicate that the area of very high vulnerability increased by 7% when land subsidence was added. Hence, using the CVI calculation including land subsidence parameters, the very high vulnerability area is determined to be 20% of the total coastline or 9.7 km of the total 48.7 km of coastline. This study proved that land subsidence has significant influence on coastal vulnerability in Semarang.

  15. Principles of Virus Structural Organization

    Science.gov (United States)

    Prasad, B.V. Venkataram; Schmid, Michael F

    2013-01-01

    Viruses, the molecular nanomachines infecting hosts ranging from prokaryotes to eukaryotes, come in different sizes, shapes and symmetries. Questions such as what principles govern their structural organization, what factors guide their assembly, how these viruses integrate multifarious functions into one unique structure have enamored researchers for years. In the last five decades, following Caspar and Klug's elegant conceptualization of how viruses are constructed, high resolution structural studies using X-ray crystallography and more recently cryo-EM techniques have provided a wealth of information on structures of variety of viruses. These studies have significantly furthered our understanding of the principles that underlie structural organization in viruses. Such an understanding has practical impact in providing a rational basis for the design and development of antiviral strategies. In this chapter, we review principles underlying capsid formation in a variety of viruses, emphasizing the recent developments along with some historical perspective. PMID:22297509

  16. Association between physical activity levels and physiological factors underlying mobility in young, middle-aged and older individuals living in a city district.

    Directory of Open Access Journals (Sweden)

    Luca Laudani

    Full Text Available Maintaining adequate levels of physical activity is known to preserve health status and functional independence as individuals grow older. However, the relationship between determinants of physical activity (volume and intensity and physiological factors underlying mobility (cardio-respiratory fitness, neuromuscular function and functional abilities is still unclear. The aim of this study was to investigate the association between objectively quantified physical activity and a spectrum of physiological factors underlying mobility in young, middle-aged and older individuals living in a city district. Experiments were carried out on 24 young (28 ± 2 years, 24 middle-aged (48 ± 2 years and 24 older (70 ± 3 years gender-matched volunteers. Physical activity was monitored by a wearable activity monitor to quantify volume and intensity of overall physical activity and selected habitual activities over 24 hours. Ventilatory threshold was assessed during an incremental cycling test. Torque, muscle fiber conduction velocity and agonist-antagonist coactivation were measured during maximal voluntary contraction of knee extensors and flexors. Ground reaction forces were measured during sit-to-stand and counter-movement jump. K-means cluster analysis was used to classify the participants' physical activity levels based on parameters of volume and intensity. Two clusters of physical activity volume (i.e., high and low volume and three clusters of physical activity intensity (i.e. high, medium and low intensity were identified in all participants. Cardio-respiratory fitness was associated with volume of overall physical activity as well as lying, sitting, standing, walking and stair climbing. On the other hand, neuromuscular function and functional abilities showed a significant association with intensity of overall physical activity as well as postural transition, walking and stair climbing. As a practical application, the relative role played by volume

  17. 5 CFR 551.401 - Basic principles.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Basic principles. 551.401 Section 551.401 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of Work General Provisions § 551.401 Basic principles. (a) All time...

  18. 38 CFR 70.30 - Payment principles.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Payment principles. 70.30 Section 70.30 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VHA BENEFICIARY TRAVEL UNDER 38 U.S.C. 111 § 70.30 Payment principles. (a) Subject to the other provisions of this...

  19. Nonsymmetric entropy and maximum nonsymmetric entropy principle

    International Nuclear Information System (INIS)

    Liu Chengshi

    2009-01-01

    Under the frame of a statistical model, the concept of nonsymmetric entropy which generalizes the concepts of Boltzmann's entropy and Shannon's entropy, is defined. Maximum nonsymmetric entropy principle is proved. Some important distribution laws such as power law, can be derived from this principle naturally. Especially, nonsymmetric entropy is more convenient than other entropy such as Tsallis's entropy in deriving power laws.

  20. 31 CFR 29.331 - General principle.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false General principle. 29.331 Section 29.331 Money and Finance: Treasury Office of the Secretary of the Treasury FEDERAL BENEFIT PAYMENTS UNDER... Satisfied by June 30, 1997 § 29.331 General principle. To determine whether service is creditable for the...