WorldWideScience

Sample records for numerous important physical

  1. Numerical problems in physics

    CERN Document Server

    Singh, Devraj

    2015-01-01

    Numerical Problems in Physics, Volume 1 is intended to serve the need of the students pursuing graduate and post graduate courses in universities with Physics and Materials Science as subject including those appearing in engineering, medical, and civil services entrance examinations. KEY FEATURES: * 29 chapters on Optics, Wave & Oscillations, Electromagnetic Field Theory, Solid State Physics & Modern Physics * 540 solved numerical problems of various universities and ompetitive examinations * 523 multiple choice questions for quick and clear understanding of subject matter * 567 unsolved numerical problems for grasping concepts of the various topic in Physics * 49 Figures for understanding problems and concept

  2. Numerical simulation in plasma physics

    International Nuclear Information System (INIS)

    Samarskii, A.A.

    1980-01-01

    Plasma physics is not only a field for development of physical theories and mathematical models but also an object of application of the computational experiment comprising analytical and numerical methods adapted for computers. The author considers only MHD plasma physics problems. Examples treated are dissipative structures in plasma; MHD model of solar dynamo; supernova explosion simulation; and plasma compression by a liner. (Auth.)

  3. Physical and Relativistic Numerical Cosmology.

    Science.gov (United States)

    Anninos, Peter

    1998-01-01

    In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations addressing specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark-hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.

  4. Physical and Relativistic Numerical Cosmology

    Directory of Open Access Journals (Sweden)

    Peter Anninos

    1998-01-01

    Full Text Available In order to account for the observable Universe, any comprehensive theory or model of cosmology must draw from many disciplines of physics, including gauge theories of strong and weak interactions, the hydrodynamics and microphysics of baryonic matter, electromagnetic fields, and spacetime curvature, for example. Although it is difficult to incorporate all these physical elements into a single complete model of our Universe, advances in computing methods and technologies have contributed significantly towards our understanding of cosmological models, the Universe, and astrophysical processes within them. A sample of numerical calculations addressing specific issues in cosmology are reviewed in this article: from the Big Bang singularity dynamics to the fundamental interactions of gravitational waves; from the quark--hadron phase transition to the large scale structure of the Universe. The emphasis, although not exclusively, is on those calculations designed to test different models of cosmology against the observed Universe.

  5. Numerical computation of generalized importance functions

    International Nuclear Information System (INIS)

    Gomit, J.M.; Nasr, M.; Ngyuen van Chi, G.; Pasquet, J.P.; Planchard, J.

    1981-01-01

    Thus far, an important effort has been devoted to developing and applying generalized perturbation theory in reactor physics analysis. In this work we are interested in the calculation of the importance functions by the method of A. Gandini. We have noted that in this method the convergence of the iterative procedure adopted is not rapid. Hence to accelerate this convergence we have used the semi-iterative technique. Two computer codes have been developed for one and two dimensional calculations (SPHINX-1D and SPHINX-2D). The advantage of our calculation was confirmed by some comparative tests in which the iteration number and the computing time were highly reduced with respect to classical calculation (CIAP-1D and CIAP-2D). (orig.) [de

  6. Why Physical Activity Is Important (for Girls)

    Science.gov (United States)

    ... Home Fitness Why physical activity is important Why physical activity is important You may wonder if being physically ... you are to be around. That's partly because physical activity gets your brain to make "feel-good" chemicals ...

  7. Exploring New Physics Frontiers Through Numerical Relativity.

    Science.gov (United States)

    Cardoso, Vitor; Gualtieri, Leonardo; Herdeiro, Carlos; Sperhake, Ulrich

    2015-01-01

    The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology.

  8. Coincidental match of numerical simulation and physics

    Science.gov (United States)

    Pierre, B.; Gudmundsson, J. S.

    2010-08-01

    Consequences of rapid pressure transients in pipelines range from increased fatigue to leakages and to complete ruptures of pipeline. Therefore, accurate predictions of rapid pressure transients in pipelines using numerical simulations are critical. State of the art modelling of pressure transient in general, and water hammer in particular include unsteady friction in addition to the steady frictional pressure drop, and numerical simulations rely on the method of characteristics. Comparison of rapid pressure transient calculations by the method of characteristics and a selected high resolution finite volume method highlights issues related to modelling of pressure waves and illustrates that matches between numerical simulations and physics are purely coincidental.

  9. Some important questions in charmonium physics

    International Nuclear Information System (INIS)

    Seth, K.

    1994-01-01

    This paper is devoted to three propositions: (1) Some of the most basic questions in heavy-quark physics remain unanswered; (2) Charmonium physics is the best place to address those questions at the required level of precision; (3) A tau-charm factory, with a commensurate state-of-the-art detector, are mandatory for doing the job. While open-charm and tau physics will certainly be done at beauty factories, charmonium physics will not. It must, therefore, form an important part of the physics program at a tau charm factory. With this as an introduction, the author then reviews the status of charmonium studies at this point, and ongoing work, with its projected weaknesses

  10. NATO Advanced Study Institute on Advanced Physical Oceanographic Numerical Modelling

    CERN Document Server

    1986-01-01

    This book is a direct result of the NATO Advanced Study Institute held in Banyuls-sur-mer, France, June 1985. The Institute had the same title as this book. It was held at Laboratoire Arago. Eighty lecturers and students from almost all NATO countries attended. The purpose was to review the state of the art of physical oceanographic numerical modelling including the parameterization of physical processes. This book represents a cross-section of the lectures presented at the ASI. It covers elementary mathematical aspects through large scale practical aspects of ocean circulation calculations. It does not encompass every facet of the science of oceanographic modelling. We have, however, captured most of the essence of mesoscale and large-scale ocean modelling for blue water and shallow seas. There have been considerable advances in modelling coastal circulation which are not included. The methods section does not include important material on phase and group velocity errors, selection of grid structures, advanc...

  11. Hygrothermal Numerical Simulation Tools Applied to Building Physics

    CERN Document Server

    Delgado, João M P Q; Ramos, Nuno M M; Freitas, Vasco Peixoto

    2013-01-01

    This book presents a critical review on the development and application of hygrothermal analysis methods to simulate the coupled transport processes of Heat, Air, and Moisture (HAM) transfer for one or multidimensional cases. During the past few decades there has been relevant development in this field of study and an increase in the professional use of tools that simulate some of the physical phenomena that are involved in Heat, Air and Moisture conditions in building components or elements. Although there is a significant amount of hygrothermal models referred in the literature, the vast majority of them are not easily available to the public outside the institutions where they were developed, which restricts the analysis of this book to only 14 hygrothermal modelling tools. The special features of this book are (a) a state-of-the-art of numerical simulation tools applied to building physics, (b) the boundary conditions importance, (c) the material properties, namely, experimental methods for the measuremen...

  12. Numerical precision calculations for LHC physics

    Energy Technology Data Exchange (ETDEWEB)

    Reuschle, Christian Andreas

    2013-02-05

    In this thesis I present aspects of QCD calculations, which are related to the fully numerical evaluation of next-to-leading order (NLO) QCD amplitudes, especially of the one-loop contributions, and the efficient computation of associated collider observables. Two interrelated topics have thereby been of concern to the thesis at hand, which give rise to two major parts. One large part is focused on the general group-theoretical behavior of one-loop QCD amplitudes, with respect to the underlying SU(N{sub c}) theory, in order to correctly and efficiently handle the color degrees of freedom in QCD one-loop amplitudes. To this end a new method is introduced that can be used in order to express color-ordered partial one-loop amplitudes with multiple quark-antiquark pairs as shuffle sums over cyclically ordered primitive one-loop amplitudes. The other large part is focused on the local subtraction of divergences off the one-loop integrands of primitive one-loop amplitudes. A method for local UV renormalization has thereby been developed, which uses local UV counterterms and efficient recursive routines. Together with suitable virtual soft and collinear subtraction terms, the subtraction method is extended to the virtual contributions in the calculations of NLO observables, which enables the fully numerical evaluation of the one-loop integrals in the virtual contributions. The method has been successfully applied to the calculation of jet rates in electron-positron annihilation to NLO accuracy in the large-N{sub c} limit.

  13. Numerical precision calculations for LHC physics

    International Nuclear Information System (INIS)

    Reuschle, Christian Andreas

    2013-01-01

    In this thesis I present aspects of QCD calculations, which are related to the fully numerical evaluation of next-to-leading order (NLO) QCD amplitudes, especially of the one-loop contributions, and the efficient computation of associated collider observables. Two interrelated topics have thereby been of concern to the thesis at hand, which give rise to two major parts. One large part is focused on the general group-theoretical behavior of one-loop QCD amplitudes, with respect to the underlying SU(N c ) theory, in order to correctly and efficiently handle the color degrees of freedom in QCD one-loop amplitudes. To this end a new method is introduced that can be used in order to express color-ordered partial one-loop amplitudes with multiple quark-antiquark pairs as shuffle sums over cyclically ordered primitive one-loop amplitudes. The other large part is focused on the local subtraction of divergences off the one-loop integrands of primitive one-loop amplitudes. A method for local UV renormalization has thereby been developed, which uses local UV counterterms and efficient recursive routines. Together with suitable virtual soft and collinear subtraction terms, the subtraction method is extended to the virtual contributions in the calculations of NLO observables, which enables the fully numerical evaluation of the one-loop integrals in the virtual contributions. The method has been successfully applied to the calculation of jet rates in electron-positron annihilation to NLO accuracy in the large-N c limit.

  14. Numerical methods in physical and economic sciences

    International Nuclear Information System (INIS)

    Lions, J.L.; Marchouk, G.I.

    1974-01-01

    This book is the first of a series to be published simultaneously in French and Russian. Some results obtained in the framework of an agreement of French-Soviet scientific collaboration in the field of the information processing are exposed. In the first part, the iterative methods for solving linear systems are studied with new methods which are compared to already known methods. Iterative methods of minimization of quadratic functionals are then studied. In the second part, the optimization problems with one or many criteria, issued from Physics and Economics problems are considered and splitting and decentralizing methods systematically studied [fr

  15. Numerical computation of special functions with applications to physics

    CSIR Research Space (South Africa)

    Motsepe, K

    2008-09-01

    Full Text Available Students of mathematical physics, engineering, natural and biological sciences sometimes need to use special functions that are not found in ordinary mathematical software. In this paper a simple universal numerical algorithm is developed to compute...

  16. REPFLO model evaluation, physical and numerical consistency

    International Nuclear Information System (INIS)

    Wilson, R.N.; Holland, D.H.

    1978-11-01

    This report contains a description of some suggested changes and an evaluation of the REPFLO computer code, which models ground-water flow and nuclear-waste migration in and about a nuclear-waste repository. The discussion contained in the main body of the report is supplemented by a flow chart, presented in the Appendix of this report. The suggested changes are of four kinds: (1) technical changes to make the code compatible with a wider variety of digital computer systems; (2) changes to fill gaps in the computer code, due to missing proprietary subroutines; (3) changes to (a) correct programming errors, (b) correct logical flaws, and (c) remove unnecessary complexity; and (4) changes in the computer code logical structure to make REPFLO a more viable model from the physical point of view

  17. Importance of enjoyment when promoting physical exercise.

    Science.gov (United States)

    Hagberg, L A; Lindahl, B; Nyberg, L; Hellénius, M-L

    2009-10-01

    The purpose of this study was to investigate the importance of enjoyment of exercise in a health care-based intervention aimed at promoting physical exercise in primary health care patients. In a controlled study design, the intervention group was offered a wide range of group exercises over 3 months, followed by support in designing their own exercise program. The control group received usual care. Enjoyment of exercise and exercise level were measured. Associations between enjoyment and exercise level were analyzed using Spearman's rank correlation coefficients. Changes in enjoyment between and within study groups were analyzed by the independent and paired t-test. Associations were found between enjoyment and exercise level (r=0.36, Pexercise level (r=0.34, Pexercise was 25% higher in the intervention group than in the control group (Phealth care patients, enjoyment of exercise was associated with exercise level. Enjoyment of exercise seems to be a mediator of exercise level. Furthermore, health care-based interventions seem to be able to affect enjoyment of exercise. Enjoyment of exercise may be important for the long-term effectiveness, of health care-based interventions.

  18. CERN: Important summer for LEAR physics

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    An integral part of CERN's comprehensive antiproton facilities is the LEAR low energy antiproton ring which came into action for physics in 1983 and has gone on to host many experiments looking at a wide range of physics topics. With CERN's big SPS proton-antiproton collider now in what could be its final production physics run after an illustrious career which began in 1981, the face of antiproton physics at CERN will change over the next few years. However LEAR runs independently of high energy antiproton operations, and any phasing out of collider operations has no direct impact on LEAR

  19. CERN: Important summer for LEAR physics

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1990-12-15

    An integral part of CERN's comprehensive antiproton facilities is the LEAR low energy antiproton ring which came into action for physics in 1983 and has gone on to host many experiments looking at a wide range of physics topics. With CERN's big SPS proton-antiproton collider now in what could be its final production physics run after an illustrious career which began in 1981, the face of antiproton physics at CERN will change over the next few years. However LEAR runs independently of high energy antiproton operations, and any phasing out of collider operations has no direct impact on LEAR.

  20. Numerical considerations for Lagrangian stochastic dispersion models: Eliminating rogue trajectories, and the importance of numerical accuracy

    Science.gov (United States)

    When Lagrangian stochastic models for turbulent dispersion are applied to complex flows, some type of ad hoc intervention is almost always necessary to eliminate unphysical behavior in the numerical solution. This paper discusses numerical considerations when solving the Langevin-based particle velo...

  1. Numerical simulation and physical aspects of supersonic vortex breakdown

    Science.gov (United States)

    Liu, C. H.; Kandil, O. A.; Kandil, H. A.

    1993-01-01

    Existing numerical simulations and physical aspects of subsonic and supersonic vortex-breakdown modes are reviewed. The solution to the problem of supersonic vortex breakdown is emphasized in this paper and carried out with the full Navier-Stokes equations for compressible flows. Numerical simulations of vortex-breakdown modes are presented in bounded and unbounded domains. The effects of different types of downstream-exit boundary conditions are studied and discussed.

  2. Numerical perturbative methods in the quantum theory of physical systems

    International Nuclear Information System (INIS)

    Adam, G.

    1980-01-01

    During the last two decades, development of digital electronic computers has led to the deployment of new, distinct methods in theoretical physics. These methods, based on the advances of modern numerical analysis as well as on specific equations describing physical processes, enabled to perform precise calculations of high complexity which have completed and sometimes changed our image of many physical phenomena. Our efforts have concentrated on the development of numerical methods with such intrinsic performances as to allow a successful approach of some Key issues in present theoretical physics on smaller computation systems. The basic principle of such methods is to translate, in numerical analysis language, the theory of perturbations which is suited to numerical rather than to analytical computation. This idea has been illustrated by working out two problems which arise from the time independent Schroedinger equation in the non-relativistic approximation, within both quantum systems with a small number of particles and systems with a large number of particles, respectively. In the first case, we are led to the numerical solution of some quadratic ordinary differential equations (first section of the thesis) and in the second case, to the solution of some secular equations in the Brillouin area (second section). (author)

  3. The Importance of Physical Literacy for Physical Education and Recreation

    Science.gov (United States)

    Basoglu, Umut Davut

    2018-01-01

    As the basis of characteristics, qualifications, behaviors, awareness, knowledge and understanding of the development of healthy active living and physical recreation opportunities Physical Literacy (PL); has become a global concern in the fields of physical education and recreation since its first use as a term. Experts from different countries…

  4. Important physical properties of peat materials

    Science.gov (United States)

    D.H. Boelter

    1968-01-01

    Peat materials from 12 bogs in northern Minnesota, U.S.A., showed significant differences in physical properties. It is pointed out that 1) these properties can be related to the hydrology of organic soils only if the soils represent undisturbed field conditions, and 2) volumetric expressions of water content are necessary to correctly evaluate the amount of water in a...

  5. The Effects of Physical Manipulatives on Children's Numerical Strategies

    Science.gov (United States)

    Manches, Andrew; O'Malley, Claire

    2016-01-01

    This article focuses on how the representational properties of manipulatives affect the strategies children employ in problem solving. Two studies examined the effect of physical materials on 4-7-year-old children's problem solving strategies in a numerical (i.e., additive composition) task. The first study showed how children not only identified…

  6. Physical and numerical modelling of low mach number compressible flows

    International Nuclear Information System (INIS)

    Paillerre, H.; Clerc, S.; Dabbene, F.; Cueto, O.

    1999-01-01

    This article reviews various physical models that may be used to describe compressible flow at low Mach numbers, as well as the numerical methods developed at DRN to discretize the different systems of equations. A selection of thermal-hydraulic applications illustrate the need to take into account compressibility and multidimensional effects as well as variable flow properties. (authors)

  7. On the internal representation of numerical magnitude and physical size.

    Science.gov (United States)

    Fitousi, Daniel

    2014-01-01

    A nascent idea in the numerical cognition literature--the analogical hypothesis (Pinel, Piazza, Bihan, & Dehaene, 2004)--assumes a common noisy code for the representation of symbolic (e.g., numerals) and nonsymbolic (e.g., numerosity, physical size, luminance) magnitudes. The present work subjected this assumption to various tests from the perspective of General Recognition Theory (GRT; Ashby &Townsend, 1986)--a multidimensional extension of Signal Detection Theory (Green & Swets, 1966). The GRT was applied to the dimensions of numerical magnitude and physical size with the following goals: (a) characterizing the internal representation of these dimensions in the psychological space, and (b) assessing various types of (in)dependence and separability governing the perception of these dimensions. The results revealed various violations of independence and separability with Stroop incongruent, but not with Stroop congruent stimuli. The outcome suggests that there are deep differences in architecture between Stroop congruent and incongruent stimuli that reach well beyond the semantic relationship involved.

  8. Importance of basic research in nuclear physics

    International Nuclear Information System (INIS)

    Bogolyubov, N.N.

    1976-01-01

    A brief survey is given of the significance of fundamental discoveries in nuclear physics. It is shown how theoretical and experimental discoveries transform our current views of the world around us and how in their practical implementation these discoveries bring revolutionary technical development. The latest progress in the field of elementary particles and their interactions and in the field of the atomic nucleus are briefly discussed. (I.W.)

  9. [The importance of physical activity and fitness for human health].

    Science.gov (United States)

    Brandes, M

    2012-01-01

    The decline of physical activity is considered to play an important role in the deterioration of health predictors, such as overweight, and the associated increase of cardiovascular and all-cause mortality. Therefore, most interventional strategies aim for increasing physical activity. Instead of physical activity, some studies use physical fitness as a key variable. Though physical fitness is influenced by genetic factors, physical fitness has to be developed by physical activity. As recent reports demonstrate the prospective associations between physical fitness and health and mortality, these associations are not reported for physical activity. Due to the fact that physical fitness-in contrast to physical activity-is evaluated with standardized laboratory measurements, it appears advisable to assess physical fitness for prospective health perspectives. Although physical fitness is determined by genetics, physical activity is the primary modifiable determinant for increasing physical fitness and should be aimed for to improve physical fitness in interventional strategies.

  10. Importance of health physics records in litigation

    International Nuclear Information System (INIS)

    Forbes, J.L.

    1982-01-01

    The nuclear insurance pools, through American Nuclear Insurers (ANI) and the Mutual Atomic Energy Liability Underwriters (MAELU), have been providing the third-party liability insurance required of the nuclear industry by the Price-Anderson Act since 1957. Records of claims of radiation injury have been kept for twenty-five years, and a recent upsurge of the claim rate has been noted. An explanation for this new trend is postulated and some examples are discussed. The use of health physics records as evidence in litigation is described, and specific examples of the types of records required to defend against past and future claims are given

  11. Global physical and numerical stability of a nuclear reactor core

    International Nuclear Information System (INIS)

    Morales-Sandoval, Jaime; Hernandez-Solis, Augusto

    2005-01-01

    Low order models are used to investigate the influence of integration methods on observed power oscillations of some nuclear reactor simulators. The zero-power point reactor kinetics with six-delayed neutron precursor groups are time discretized using explicit, implicit and Crank-Nicholson methods, and the stability limit of the time mesh spacing is exactly obtained by locating their characteristic poles in the z-transform plane. These poles are the s to z mappings of the inhour equation roots and, except for one of them, they show little or no dependence on the integration method. Conditions for stable power oscillations can be also obtained by tracking when steady state output signals resulting from reactivity oscillations in the s-Laplace plane cross the imaginary axis. The dynamics of a BWR core operating at power conditions is represented by a reduced order model obtained by adding three ordinary differential equations, which can model void and Doppler reactivity feedback effects on power, and collapsing all delayed neutron precursors in one group. Void dynamics are modeled as a second order system and fuel heat transfer as a first order system. This model shows rich characteristics in terms of indicating the relative importance of different core parameters and conditions on both numerical and physical oscillations observed by large computer code simulations. A brief discussion of the influence of actual core and coolant conditions on the reduced order model is presented

  12. Developments in numerical simulation of IFE target and chamber physics

    International Nuclear Information System (INIS)

    Velarde, G.; Minguez, E.; Alonso, E.; Gil, J.M.; Malerba, L.; Marian, J.; Martel, P.; Martinez-Val, J.M.; Munoz, R.; Ogando, F.; Perlado, J.M.; Piera, M.; Reyes, S.; Rubiano, J.G.; Sanz, J.; Sauvan, P.; Velarde, M.; Velarde, P.

    2000-01-01

    The work presented outlines the global frame given at the Institute of Nuclear Fusion (DENIM) for having an integral perspective of the different research areas with the development of Inertial Fusion for energy generation. The coupling of a new radiation transport (RT) solver with an existing multi-material fluid dynamics code using Adaptive Mesh Refinement (ARM) is presented in Section 2, including improvements and additional information about the solver precision. In Section 3, new developments in the atomic physics codes under target conditions, to determine populations, opacity data and emissivities have been performed. Exotic and innovative ideas about Inertial Fusion Energy (IFE), as catalytic fuels and Z-pinches have been explored, and they are explained in Section 4. Numerical simulations demonstrate important reductions in the tritium inventory. Section 5 is devoted to safety and environment of the IFE. Uncertainties analysis in activation calculations have been included in the ACAB activation code, and also calculations on pulse activation in IFE reactors and on the activation of target debris in NIF are presented. A comparison of the accidental releases of tritium from some IFE reactors computed using MACCS2 code is explained. Finally, Section 6 contains the research on the basic mechanisms of neutron damage in SiC (low-activation material) and FeCu alloy using the DENIM/LLNL molecular dynamics code MDCASK. (authors)

  13. Importance of soil physical characteristics for petroleum ...

    African Journals Online (AJOL)

    Public PCs

    interaction between the soil, plant and organisms (Zhang et al., 2010). .... only the diversity and abundance of the clay, minerals is an important ..... the main supplier of the essential water for plant growth. Soil water ... This also leads to inhibition of roots to ..... contaminated soil with pentachlorophenol and cadmium. Int. J.

  14. Physical and numerical modeling of Joule-heated melters

    Energy Technology Data Exchange (ETDEWEB)

    Eyler, L.L.; Skarda, R.J.; Crowder, R.S. III; Trent, D.S.; Reid, C.R.; Lessor, D.L.

    1985-10-01

    The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable. 14 refs., 79 figs., 17 tabs.

  15. Physical and numerical modeling of Joule-heated melters

    International Nuclear Information System (INIS)

    Eyler, L.L.; Skarda, R.J.; Crowder, R.S. III; Trent, D.S.; Reid, C.R.; Lessor, D.L.

    1985-10-01

    The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable. 14 refs., 79 figs., 17 tabs

  16. Radiation Diffusion: An Overview of Physical and Numerical Concepts

    International Nuclear Information System (INIS)

    Graziani, F R

    2005-01-01

    An overview of the physical and mathematical foundations of radiation transport is given. Emphasis is placed on how the diffusion approximation and its transport corrections arise. An overview of the numerical handling of radiation diffusion coupled to matter is also given. Discussions center on partial temperature and grey methods with comments concerning fully implicit methods. In addition finite difference, finite element and Pert representations of the div-grad operator is also discussed

  17. Prof. Ikeda’s important contributions to nuclear physics

    CERN Document Server

    Brink, D M

    2010-01-01

    Professor Ikeda has made many fundamental contributions to nuclear physics, especially to the theory of Gamow-Teller giant resonances, to nuclear cluster physics, to hypernuclear physics, and to the physics of neutron-rich nuclei. He also has played an important role in the education of young researchers in Japan and on the contacts between theoreticians and experimentalists.

  18. 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.

  19. Numerical and physical testing of upscaling techniques for constitutive properties

    International Nuclear Information System (INIS)

    McKenna, S.A.; Tidwell, V.C.

    1995-01-01

    This paper evaluates upscaling techniques for hydraulic conductivity measurements based on accuracy and practicality for implementation in evaluating the performance of the potential repository at Yucca Mountain. Analytical and numerical techniques are compared to one another, to the results of physical upscaling experiments, and to the results obtained on the original domain. The results from different scaling techniques are then compared to the case where unscaled point scale statistics are used to generate realizations directly at the flow model grid-block scale. Initital results indicate that analytical techniques provide upscaling constitutive properties from the point measurement scale to the flow model grid-block scale. However, no single analytic technique proves to be adequate for all situations. Numerical techniques are also accurate, but they are time intensive and their accuracy is dependent on knowledge of the local flow regime at every grid-block

  20. The importance of fats in food of persons physically active

    Directory of Open Access Journals (Sweden)

    Tomasz Włodarczyk

    2017-07-01

    Full Text Available A diet program of physically active individuals accounts for about 50% of the success in attaining the desired physical form. Patterns that include resting metabolism, physical activity, and daily energy expenditure, as needed: reduction, stabilization, weight gain, are used. Among those who practice sports for whom nutrition is of great importance in achieving their goal, recently, there has been a great deal of interest in ketogenic diets, low carbohydrates commonly called "fatty". Therefore, it is important to explain the importance, types and role of fats in the nutrition of physically active persons.

  1. The Importance of High School Physics Teachers for Female Students' Physics Identity and Persistence

    Science.gov (United States)

    Hazari, Zahra; Brewe, Eric; Goertzen, Renee Michelle; Hodapp, Theodore

    2017-01-01

    Given the historic and continued underrepresentation of women in physics, it is important to understand the role that high school physics might play in attracting female students to physics careers. Drawing on data from over 900 female undergraduates in physics, we examine when these women became interested in physics careers and different sources…

  2. [Physical activity and its importance in the workplace].

    Science.gov (United States)

    Masala, Daniele; Mannocci, Alice; Sinopoli, Alessandra; D'Egidio, Valeria; Villari, Paolo; La Torre, Giuseppe

    2017-01-01

    The present study aims to highlight the importance of physical activity in the workplace and its fundamental role for the wellness of an individual. The relationship between sedentary lifestyle and health is supported by several epidemiological studies and inactivity is one of the main risk factors for cardiovascular disease, chronic conditions and cancer. According to the World Health Organization, physical activity represents: "any bodily movement produced by skeletal muscles that requires energy expenditure". The promotion of regular physical activity, including its promotion in the workplace is of fundamental importance since a close correlation exists between good health and physical activity. Moreover, regular physical activity improves psycho-physical performance, social relationships, work performance and reduces sickness, absenteeism from work and work injuries.

  3. Physics, mathematics and numerics of particle adsorption on fluid interfaces

    Science.gov (United States)

    Schmuck, Markus; Pavliotis, Grigorios A.; Kalliadasis, Serafim

    2012-11-01

    We study two arbitrary immiscible fuids where one phase contains small particles of the size of the interface and smaller. We primarily focus on charge-free particles with wetting characteristics described by the contact angle formed at the interface between the two phases and the particles. Based on the experimental observation that particles are adsorbed on the interface to reduce the interfacial energy and hence the surface tension as well, we formulate a free-energy functional that accounts for these physical effects. Using elements from calculus of variations and formal gradient flow theory, we derive partial differential equations describing the location of the interface and the density of the particles in the fluid phases. Via numerical experiments we analyse the time evolution of the surface tension, the particle concentration, and the free energy over time and reflect basic experimentally observed phenomena.

  4. Holistic simulation of geotechnical installation processes numerical and physical modelling

    CERN Document Server

    2015-01-01

    The book provides suitable methods for the simulations of boundary value problems of geotechnical installation processes with reliable prediction for the deformation behavior of structures in static or dynamic interaction with the soil. It summarizes the basic research of a research group from scientists dealing with constitutive relations of soils and their implementations as well as contact element formulations in FE-codes. Numerical and physical experiments are presented providing benchmarks for future developments in this field. Boundary value problems have been formulated and solved with the developed tools in order to show the effectivity of the methods. Parametric studies of geotechnical installation processes in order to identify the governing parameters for the optimization of the process are given in such a way that the findings can be recommended to practice for further use. For many design engineers in practice the assessment of the serviceability of nearby structures due to geotechnical installat...

  5. Numerical Modeling of Piezoelectric Transducers Using Physical Parameters

    NARCIS (Netherlands)

    Cappon, H.; Keesman, K.J.

    2012-01-01

    Design of ultrasonic equipment is frequently facilitated with numerical models. These numerical models, however, need a calibration step, because usually not all characteristics of the materials used are known. Characterization of material properties combined with numerical simulations and

  6. Evaluation of spacer grid spring characteristics by means of physical tests and numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Schettino, Carlos Frederico Mattos, E-mail: carlosschettino@inb.gov.br [Industrias Nucleares do Brasil (INB), Resende, RJ (Brazil)

    2017-11-01

    Among all fuel assemblies' components, the spacer grids play an important structural role during the energy generation process, mainly due for its primary functional requirement, that is, to provide fuel rod support. The present work aims to evaluate the spring characteristics of a specific spacer grid design used in a PWR fuel assembly type 16 x 16. These spring characteristics comprises the load versus deflection capability and its spring rate, which are very important, and also mandatory, to be correctly established in order to preclude spacer grid spring and fuel rod cladding fretting during operation, as well as prevent an excessive fuel rod buckling. This study includes physical tests and numerical simulation. The tests were performed on an adapted load cell mechanical device, using as a specimen a single strap of the spacer grid. Three numerical models were prepared using the Finite Element Method, with the support of the commercial code ANSYS. One model was built to validate the simulation according to the performed physical test, the others were built inserting a gradient of temperature (Beginning Of Life hot condition) and to evaluate the spacer grid spring characteristics in End Of Life condition. The obtained results from physical test and numerical model have shown a good agreement between them, therefore validating the simulation. The obtained results from numerical models make available information regarding the spacer grid design purpose, such as the behavior of the fuel rod cladding support during operation. Therewith, these evaluations could be useful to improve the spacer grid design. (author)

  7. Evaluation of spacer grid spring characteristics by means of physical tests and numerical simulation

    International Nuclear Information System (INIS)

    Schettino, Carlos Frederico Mattos

    2017-01-01

    Among all fuel assemblies' components, the spacer grids play an important structural role during the energy generation process, mainly due for its primary functional requirement, that is, to provide fuel rod support. The present work aims to evaluate the spring characteristics of a specific spacer grid design used in a PWR fuel assembly type 16 x 16. These spring characteristics comprises the load versus deflection capability and its spring rate, which are very important, and also mandatory, to be correctly established in order to preclude spacer grid spring and fuel rod cladding fretting during operation, as well as prevent an excessive fuel rod buckling. This study includes physical tests and numerical simulation. The tests were performed on an adapted load cell mechanical device, using as a specimen a single strap of the spacer grid. Three numerical models were prepared using the Finite Element Method, with the support of the commercial code ANSYS. One model was built to validate the simulation according to the performed physical test, the others were built inserting a gradient of temperature (Beginning Of Life hot condition) and to evaluate the spacer grid spring characteristics in End Of Life condition. The obtained results from physical test and numerical model have shown a good agreement between them, therefore validating the simulation. The obtained results from numerical models make available information regarding the spacer grid design purpose, such as the behavior of the fuel rod cladding support during operation. Therewith, these evaluations could be useful to improve the spacer grid design. (author)

  8. Integrating numerical computation into the undergraduate education physics curriculum using spreadsheet excel

    Science.gov (United States)

    Fauzi, Ahmad

    2017-11-01

    Numerical computation has many pedagogical advantages: it develops analytical skills and problem-solving skills, helps to learn through visualization, and enhances physics education. Unfortunately, numerical computation is not taught to undergraduate education physics students in Indonesia. Incorporate numerical computation into the undergraduate education physics curriculum presents many challenges. The main challenges are the dense curriculum that makes difficult to put new numerical computation course and most students have no programming experience. In this research, we used case study to review how to integrate numerical computation into undergraduate education physics curriculum. The participants of this research were 54 students of the fourth semester of physics education department. As a result, we concluded that numerical computation could be integrated into undergraduate education physics curriculum using spreadsheet excel combined with another course. The results of this research become complements of the study on how to integrate numerical computation in learning physics using spreadsheet excel.

  9. Symbolic Numerical Magnitude Processing Is as Important to Arithmetic as Phonological Awareness Is to Reading.

    Directory of Open Access Journals (Sweden)

    Kiran Vanbinst

    Full Text Available In this article, we tested, using a 1-year longitudinal design, whether symbolic numerical magnitude processing or children's numerical representation of Arabic digits, is as important to arithmetic as phonological awareness is to reading. Children completed measures of symbolic comparison, phonological awareness, arithmetic, reading at the start of third grade and the latter two were retested at the start of fourth grade. Cross-sectional and longitudinal correlations indicated that symbolic comparison was a powerful domain-specific predictor of arithmetic and that phonological awareness was a unique predictor of reading. Crucially, the strength of these independent associations was not significantly different. This indicates that symbolic numerical magnitude processing is as important to arithmetic development as phonological awareness is to reading and suggests that symbolic numerical magnitude processing is a good candidate for screening children at risk for developing mathematical difficulties.

  10. Complex transfers in porous media: some physical and numerical approaches

    International Nuclear Information System (INIS)

    Maugis, P.

    2006-06-01

    The feasibility and safety of nuclear waste storage containers is studied. The thermodynamics of water/air flow is described and applied, via a simplified numerical model, to a simple experimental apparatus yielding heat pipe effect. The 2D influence of deterministic boundary conditions is important on kinematics and transport. Dispersivity depends on the nonuniform flow type and integrates the often marginal Gaussian part of plume spreading. A new algorithm, based on jump locality and recalibration, avoids the small bias induced by inter-cell diffusive jumps. Several algorithms modeling transport of decaying, soluble, sorbing, or precipitating species are compared. Stability and precision criteria are analyzed. Up-stream over-precipitation and negative down-stream concentrations are observed for high solubility contrasts. (author)

  11. Important atomic physics issues for ion beam fusion

    International Nuclear Information System (INIS)

    Bangerter, Roger.

    1986-01-01

    The nearly endless variety of interesting and challenging problems makes physics research enjoyable. Most of us would choose to be physicists even if physics had no practical applications. However, physics does have practical applications. This workshop deals with one of those applications, namely ion beam fusion. Not all interesting and challenging atomic physics questions are important for ion beam fusion. This paper suggests some questions that may be important for ion beam fusion. It also suggests some criteria for determining if a question is only interesting, or both interesting and important. Importance is time dependent and, because of some restrictions on the flow of information, also country dependent. In the early days of ion beam fusion, it was important to determine if ion beam fusion made sense. Approximate answers and bounds on various parameters were required. Accurate, detailed answers were not needed. Because of the efforts of many people attending this workshop, we now know that ion beam fusion does make some sense. We must still determine if ion beam fusion truly makes good sense. If it does make good sense, we must determine how to make it work. Accurate detailed answers are becoming increasingly important. (author)

  12. Numerical Simulations of Granular Physics in the Solar System

    Science.gov (United States)

    Ballouz, Ronald

    2017-08-01

    Granular physics is a sub-discipline of physics that attempts to combine principles that have been developed for both solid-state physics and engineering (such as soil mechanics) with fluid dynamics in order to formulate a coherent theory for the description of granular materials, which are found in both terrestrial (e.g., earthquakes, landslides, and pharmaceuticals) and extra-terrestrial settings (e.g., asteroids surfaces, asteroid interiors, and planetary ring systems). In the case of our solar system, the growth of this sub-discipline has been key in helping to interpret the formation, structure, and evolution of both asteroids and planetary rings. It is difficult to develop a deterministic theory for granular materials due to the fact that granular systems are composed of a large number of elements that interact through a non-linear combination of various forces (mechanical, gravitational, and electrostatic, for example) leading to a high degree of stochasticity. Hence, we study these environments using an N-body code, pkdgrav, that is able to simulate the gravitational, collisional, and cohesive interactions of grains. Using pkdgrav, I have studied the size segregation on asteroid surfaces due to seismic shaking (the Brazil-nut effect), the interaction of the OSIRIS-REx asteroid sample-return mission sampling head, TAGSAM, with the surface of the asteroid Bennu, the collisional disruptions of rubble-pile asteroids, and the formation of structure in Saturn's rings. In all of these scenarios, I have found that the evolution of a granular system depends sensitively on the intrinsic properties of the individual grains (size, shape, sand surface roughness). For example, through our simulations, we have been able to determine relationships between regolith properties and the amount of surface penetration a spacecraft achieves upon landing. Furthermore, we have demonstrated that this relationship also depends on the strength of the local gravity. By comparing our

  13. Neutrino physics today, important issues and the future

    Energy Technology Data Exchange (ETDEWEB)

    Parke, Stephen J.; /Fermilab

    2010-10-01

    The status and the most important issues in neutrino physics will be summarized as well as how the current, pressing questions will be addressed by future experiments. Since the discovery of neutrino flavor transitions by the SuperKamiokande experiment in 1998, which demonstrates that neutrinos change and hence their clocks tick, i.e. they are not traveling at the speed of light and hence are not massless, the field of neutrino physics has made remarkable progress in untangling the nature of the neutrino. However, there are still many important questions to answer.

  14. Numerical and physical modelling of oil spreading in broken ice

    International Nuclear Information System (INIS)

    Gjoesteen, Janne K. Oekland

    2002-01-01

    The present work focuses on oil spreading in broken ice and the content of this thesis falls into three categories: 1) The physical and numerical modelling of oil spreading in ice. 2) Ice models and parameters describing the ice cover. 3) Experiments on oil spreading in broken ice. A background study was carried out to investigate existing models for simulating oil in broken ice. Most of them describe motion of oil simply as a function of the ice motion and do not take advantage of the possibilities that recent ice models provide. We decided to choose another direction, starting from scratch with equations describing the flow of oil on top of a water surface. The equations were implemented numerically, including proper boundary conditions to account for the presence of physical restrictions in the form of ice floes in the simulation area. The implementation was designed to be able to apply data on ice motion calculated by an existing dynamic ice model. A first validation of the model was carried out using existing experimental data. As those data were obtained in a different setting, the recorded parameters and set-up of the experiment were not ideal for our purpose. However, we were able to conclude that our model behaviour was reasonable. We have carried out statistical analysis on meteorological data of wind speeds, temperatures, flow sizes and ice thickness to obtain probability distributions describing the parameters. Those data has been collected in the Pechora Sea. Wind and temperature had been recorded for a period of 30-40 years. For this region we also had available Argos satellite data from four buoys drifting in the ice in April-June 1998. The Argos data were carefully analysed to suggest probability distributions and return periods for certain speeds. (Indoor basin tests were carried out to obtain data on spreading of oil in broken ice. A set of 20 tests was conducted, each with different type of oil, ice concentration, slush concentration or ice

  15. Numerical and physical modelling of oil spreading in broken ice

    Energy Technology Data Exchange (ETDEWEB)

    Gjoesteen, Janne K. Oekland

    2002-07-01

    The present work focuses on oil spreading in broken ice and the content of this thesis falls into three categories: 1) The physical and numerical modelling of oil spreading in ice. 2) Ice models and parameters describing the ice cover. 3) Experiments on oil spreading in broken ice. A background study was carried out to investigate existing models for simulating oil in broken ice. Most of them describe motion of oil simply as a function of the ice motion and do not take advantage of the possibilities that recent ice models provide. We decided to choose another direction, starting from scratch with equations describing the flow of oil on top of a water surface. The equations were implemented numerically, including proper boundary conditions to account for the presence of physical restrictions in the form of ice floes in the simulation area. The implementation was designed to be able to apply data on ice motion calculated by an existing dynamic ice model. A first validation of the model was carried out using existing experimental data. As those data were obtained in a different setting, the recorded parameters and set-up of the experiment were not ideal for our purpose. However, we were able to conclude that our model behaviour was reasonable. We have carried out statistical analysis on meteorological data of wind speeds, temperatures, flow sizes and ice thickness to obtain probability distributions describing the parameters. Those data has been collected in the Pechora Sea. Wind and temperature had been recorded for a period of 30-40 years. For this region we also had available Argos satellite data from four buoys drifting in the ice in April-June 1998. The Argos data were carefully analysed to suggest probability distributions and return periods for certain speeds. (Indoor basin tests were carried out to obtain data on spreading of oil in broken ice. A set of 20 tests was conducted, each with different type of oil, ice concentration, slush concentration or ice

  16. The importance of the food and physical activity environments.

    Science.gov (United States)

    Oppert, Jean-Michel; Charreire, Hélène

    2012-01-01

    There is increasing interest in identifying characteristics of neighborhood environments (physical, social, economical) that might favor unhealthy dietary and physical activity patterns leading to excess weight at population level. Measurement of characteristics of the physical environment in relation to food and physical activity has greatly improved in recent years. Methods based on assessment of perceptions by residents of their neighborhood or on objective assessment of the actual built environment (such as provided by Geographic Information Systems tools) would benefit to be combined. A number of recent systematic reviews have updated our knowledge on relationships of food and physical activity environments with relevant behaviors and obesity. Available evidence appears to show more consistent evidence of association between built environment characteristics related to physical activity ('walkability' indices, land use mix, variety of transports. . .) with physical activity behavior than with weight status. In contrast, built environment characteristics related to food habits (accessibility to different types of food outlets, availability of healthy foods. . .) would be more consistently associated with weight status than with eating behavior. The need for data from different countries and cultures is emphasized, as much as the importance of transdisciplinary research efforts for translation of these findings into our living environment. Copyright © 2012 Nestec Ltd., Vevey/S. Karger AG, Basel.

  17. The Importance of Monitoring Skills in Physics Problem Solving

    Science.gov (United States)

    Ali, Marlina; Talib, Corrienna-Abd; Hasniza Ibrahim, Nor; Surif, Johari; Halim Abdullah, Abdul

    2016-01-01

    The purpose of this paper is to show how important "monitoring" is as metacognitive skills in solving physics problems in the field mechanics. Based on test scores, twenty one students were divided into two groups: more successful (MS) and less successful (LS) problem solvers. Students were allowed to think-aloud while they worked on…

  18. Important atomic physics issues for ion beam fusion

    International Nuclear Information System (INIS)

    Bangerter, R.O.

    1985-01-01

    This paper suggests several current atomic physics questions important to ion beam fusion. Among the topics discussed are beam transport, beam-target interaction, and reactor design. The major part of the report is discussion concerning areas of research necessary to better understand beam-target interactions

  19. Micromagnetic simulations with thermal noise: Physical and numerical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, E. [Dept. de Ingenieria Electromecanica, Universidad de Burgos, Plaza Misael Banuelos, s/n, E-09001, Burgos (Spain)]. E-mail: emvecino@ubu.es; Lopez-Diaz, L. [Dept. de Fisica Aplicada, Universidad Salamanca, Plaza de la Merced s/n, Salamanca E-37008 (Spain); Torres, L. [Dept. de Fisica Aplicada, Universidad Salamanca, Plaza de la Merced s/n, Salamanca E-37008 (Spain); Garcia-Cervera, C.J. [Department of Mathematics, University of California, Santa Barbara, CA 93106 (United States)

    2007-09-15

    Langevin dynamics treats finite temperature effects in micromagnetics framework by adding a thermal fluctuation field to the local effective field. Several works have addressed that the numerical results depend on the cell size used to split the ferromagnetic samples on the nanoscale regime. In this short paper, we analyze a thermally perturbed micromagnetic problem by using an implicit unconditionally stable numerical scheme to integrate the Langevin equation at room temperature. The obtained micromagnetic results for several cell sizes inside the validity range of the micromagnetic formalism, indicate that the addressed cell size dependence could be associated to numerical limitations of the commonly used numerical schemes.

  20. Micromagnetic simulations with thermal noise: Physical and numerical aspects

    International Nuclear Information System (INIS)

    Martinez, E.; Lopez-Diaz, L.; Torres, L.; Garcia-Cervera, C.J.

    2007-01-01

    Langevin dynamics treats finite temperature effects in micromagnetics framework by adding a thermal fluctuation field to the local effective field. Several works have addressed that the numerical results depend on the cell size used to split the ferromagnetic samples on the nanoscale regime. In this short paper, we analyze a thermally perturbed micromagnetic problem by using an implicit unconditionally stable numerical scheme to integrate the Langevin equation at room temperature. The obtained micromagnetic results for several cell sizes inside the validity range of the micromagnetic formalism, indicate that the addressed cell size dependence could be associated to numerical limitations of the commonly used numerical schemes

  1. Numerically Accelerated Importance Sampling for Nonlinear Non-Gaussian State Space Models

    NARCIS (Netherlands)

    Koopman, S.J.; Lucas, A.; Scharth, M.

    2015-01-01

    We propose a general likelihood evaluation method for nonlinear non-Gaussian state-space models using the simulation-based method of efficient importance sampling. We minimize the simulation effort by replacing some key steps of the likelihood estimation procedure by numerical integration. We refer

  2. Numerical

    Directory of Open Access Journals (Sweden)

    M. Boumaza

    2015-07-01

    Full Text Available Transient convection heat transfer is of fundamental interest in many industrial and environmental situations, as well as in electronic devices and security of energy systems. Transient fluid flow problems are among the more difficult to analyze and yet are very often encountered in modern day technology. The main objective of this research project is to carry out a theoretical and numerical analysis of transient convective heat transfer in vertical flows, when the thermal field is due to different kinds of variation, in time and space of some boundary conditions, such as wall temperature or wall heat flux. This is achieved by the development of a mathematical model and its resolution by suitable numerical methods, as well as performing various sensitivity analyses. These objectives are achieved through a theoretical investigation of the effects of wall and fluid axial conduction, physical properties and heat capacity of the pipe wall on the transient downward mixed convection in a circular duct experiencing a sudden change in the applied heat flux on the outside surface of a central zone.

  3. Numerical modeling and the physical basis of seismic discriminants

    International Nuclear Information System (INIS)

    Denny, M.D.

    1993-01-01

    Accurate seismic event discrimination is critical to detection of nuclear explosions. Numerical modeling applied to seismic event discrimination can lead to increased reliability of proliferation detection. It is particularly applicable to error budgeting and to understanding explosion and earthquake phenomenologies. There also is a need for minimum requirements to validate the models used in numerical modeling

  4. A deterministic combination of numerical and physical models for coastal waves

    DEFF Research Database (Denmark)

    Zhang, Haiwen

    2006-01-01

    of numerical and physical modelling hence provides an attractive alternative to the use of either tool on it's own. The goal of this project has been to develop a deterministically combined numerical/physical model where the physical wave tank is enclosed in a much larger computational domain, and the two......Numerical and physical modelling are the two main tools available for predicting the influence of water waves on coastlines and structures placed in the near-shore environment. Numerical models can cover large areas at the correct scale, but are limited in their ability to capture strong...... nonlinearities, wave breaking, splash, mixing, and other such complicated physics. Physical models naturally include the real physics (at the model scale), but are limited by the physical size of the facility and must contend with the fact that different physical effects scale differently. An integrated use...

  5. Creating safer coastal and port infrastructure with innovative physical and numerical modelling

    CSIR Research Space (South Africa)

    Tulsi, K

    2015-10-01

    Full Text Available Infrastructure with Innovative Physical and Numerical Modelling Kishan Tulsi  Physical and Numerical modelling  Breakwater Monitoring  Armour track  Vessel manoeuvring simulations for safe port design and operations  Simflex software... – Integrated Port Operations Support System  Virtual Buoy Physical modelling Numerical modelling Armour Track Armour Track Armour Track Armour Track Armour track using 3D data points Ship manoeuvring simulations: Ship Manoeuvring simulations Port...

  6. Towards High Resolution Numerical Algorithms for Wave Dominated Physical Phenomena

    Science.gov (United States)

    2009-01-30

    Modelling and Numerical Analysis, 40(5):815-841, 2006. [31] Michael Dumbser, Martin Kaser, and Eleuterio F. Toro. An arbitrary high-order Discontinuous...proximation of PML, SIAM J. Numer. Anal., 41 (2003), pp. 287-305. [60] E. BECACHE, S. FAUQUEUX, AND P. JOLY , Stability of perfectly matched layers, group...time-domain performance analysis, IEEE Trans, on Magnetics, 38 (2002), pp. 657- 660. [64] J. DIAZ AND P. JOLY , An analysis of higher-order boundary

  7. Learning about physical parameters: the importance of model discrepancy

    International Nuclear Information System (INIS)

    Brynjarsdóttir, Jenný; O'Hagan, Anthony

    2014-01-01

    Science-based simulation models are widely used to predict the behavior of complex physical systems. It is also common to use observations of the physical system to solve the inverse problem, that is, to learn about the values of parameters within the model, a process which is often called calibration. The main goal of calibration is usually to improve the predictive performance of the simulator but the values of the parameters in the model may also be of intrinsic scientific interest in their own right. In order to make appropriate use of observations of the physical system it is important to recognize model discrepancy, the difference between reality and the simulator output. We illustrate through a simple example that an analysis that does not account for model discrepancy may lead to biased and over-confident parameter estimates and predictions. The challenge with incorporating model discrepancy in statistical inverse problems is being confounded with calibration parameters, which will only be resolved with meaningful priors. For our simple example, we model the model-discrepancy via a Gaussian process and demonstrate that through accounting for model discrepancy our prediction within the range of data is correct. However, only with realistic priors on the model discrepancy do we uncover the true parameter values. Through theoretical arguments we show that these findings are typical of the general problem of learning about physical parameters and the underlying physical system using science-based mechanistic models. (paper)

  8. Role of beliefs and emotions in numerical problem solving in university physics education

    Science.gov (United States)

    Bodin, Madelen; Winberg, Mikael

    2012-06-01

    Numerical problem solving in classical mechanics in university physics education offers a learning situation where students have many possibilities of control and creativity. In this study, expertlike beliefs about physics and learning physics together with prior knowledge were the most important predictors of the quality of performance of a task with many degrees of freedom. Feelings corresponding to control and concentration, i.e., emotions that are expected to trigger students’ intrinsic motivation, were also important in predicting performance. Unexpectedly, intrinsic motivation, as indicated by enjoyment and interest, together with students’ personal interest and utility value beliefs did not predict performance. This indicates that although a certain degree of enjoyment is probably necessary, motivated behavior is rather regulated by integration and identification of expertlike beliefs about learning and are more strongly associated with concentration and control during learning and, ultimately, with high performance. The results suggest that the development of students’ epistemological beliefs is important for students’ ability to learn from realistic problem-solving situations with many degrees of freedom in physics education.

  9. Role of beliefs and emotions in numerical problem solving in university physics education

    Directory of Open Access Journals (Sweden)

    Madelen Bodin

    2012-02-01

    Full Text Available Numerical problem solving in classical mechanics in university physics education offers a learning situation where students have many possibilities of control and creativity. In this study, expertlike beliefs about physics and learning physics together with prior knowledge were the most important predictors of the quality of performance of a task with many degrees of freedom. Feelings corresponding to control and concentration, i.e., emotions that are expected to trigger students’ intrinsic motivation, were also important in predicting performance. Unexpectedly, intrinsic motivation, as indicated by enjoyment and interest, together with students’ personal interest and utility value beliefs did not predict performance. This indicates that although a certain degree of enjoyment is probably necessary, motivated behavior is rather regulated by integration and identification of expertlike beliefs about learning and are more strongly associated with concentration and control during learning and, ultimately, with high performance. The results suggest that the development of students’ epistemological beliefs is important for students’ ability to learn from realistic problem-solving situations with many degrees of freedom in physics education.

  10. Multi-physics modeling and numerical simulation of weld pool in GTA welding

    International Nuclear Information System (INIS)

    Nguyen, Minh-Chien

    2015-01-01

    In this work, we develop a 3D physical and numerical model of the GTA (Gas Tungsten Arc) welding process in order to predict, for given welding parameters, useful quantities for the designer of welded assembly: weld bead shape, fluid flow in the weld pool as well as thermal distribution in the work piece. The model is developed in the Cast3M (http://www-cast3m.cea.fr/) finite element software and takes into account the main physical phenomena acting in the work piece and particularly in the weld pool, subject to source terms modeling the arc part of the welding process. A steady solution of this model is thought for and involves the coupling of the nonlinear thermohydraulics and electromagnetic equations together with the displacement of the deformable free surface of the weld pool. A first step in the development consisted in modeling the electromagnetic phenomena with two different numerical methods, in comparing the numerical results obtained with those of the literature and in quantifying the importance of the Lorentz force and the Joule effect compared to the other mechanical and thermal sources by computing power balances. Then, in order to assess the predictive capability of the model, simulations of various welding configurations are performed: variation in the chemical composition of the material, of the welding speed, of the prescribed arc pressure and of the welding positions, which is a focus of this work, are studied. A good agreement is obtained between the results of our model and other experimental and numerical results of the literature. Eventually, a model accounting for metal filling is proposed and its results are discussed. Thus, our complete model can be seen as a solid foundation towards future totally-coupled 3D welding models including the arc and it will be included in WPROCESS the in-house CEA software dedicated to the numerical simulation of welding. (author) [fr

  11. About numerical analysis of a plasma physics problem

    International Nuclear Information System (INIS)

    Almeida Cipolatti, R. de

    1985-01-01

    A numerical study on macroscopic equilibrium of a plasma at interior of a tokamak device, considering boundary problems for the case which f(s)=sis presented. The abstract Dirichlet problem enumerating main results which is applied to plasma model is studied. (M.C.K.) [pt

  12. Numerical tables on physical and chemical analyses of Rhine water

    International Nuclear Information System (INIS)

    1982-01-01

    Tables on the places of measurement, the sampling methods and the methods of analysis used. The numerical tables of the measurement results are broken down in general parameters, organic, entrophicating and anorganic substances, orgnic micro-pollutants and radioactivity. (GG) [de

  13. The Importance of Thermophysical Properties of Steels for the Numerical Simulation of a Concasting Process

    Directory of Open Access Journals (Sweden)

    Frantisek KAVICKA

    2010-12-01

    Full Text Available The thermophysical properties of steels have significant influence on the actual concasting process, and on the accuracy of its numerical simulation and optimization. The determination of these properties (heat conductivity, specific heat capacity and density in the solid and liquid states often requires more time than the actual numerical calculation of the temperature fields of a continuously cast steel billet, cylinder or slab (generally a concasting. The influence of individual properties should be neither under- nor over-estimated. Therefore, an analysis/parametric study of these thermophysical properties was conducted. The order of importance within the actual process and the accuracy of simulation and optimization were also determined. Individual properties, which, in some cases, were obtained from tables, and in others experimentally, were substituted by an approximation using orthogonal polynomials. The accuracy of each polynomial is dependent on the precision of individual values. The order of significance of individual thermophysical properties was determined with respect to the metallurgical length. The analysis was performed by means of a so-called calculation experiment, i.e. by means of the original and universal numerical concasting model developed by the authors of this paper. It is convenient to conduct such an analysis in order to facilitate the simulation of each individual case of concasting, thus enhancing the process of optimization.

  14. PHYSICAL AND NUMERICAL MODELING OF ASD EXHAUST DISPERSION AROUND HOUSES

    Science.gov (United States)

    The report discusses the use of a wind tunnel to physically model the dispersion of exhaust plumes from active soil depressurization (ASD) radon mitigation systems in houses. he testing studied the effects of exhaust location (grade level vs. above the eave), as house height, roo...

  15. Parent participation plays an important part in promoting physical activity

    Directory of Open Access Journals (Sweden)

    Anna-Karin Lindqvist

    2015-08-01

    Full Text Available Although physical activity (PA is an important and modifiable determinant of health, in Sweden only 15% of boys and 10% of girls aged 15 years old achieve the recommended levels of PA 7 days per week. Adolescents’ PA levels are associated with social influence exerted by parents, friends, and teachers. The purpose of this study was to describe parents’ experiences of being a part of their adolescents’ empowerment-inspired PA intervention. A qualitative interview study was performed at a school in the northern part of Sweden. A total of 10 parents were interviewed, and the collected data were analyzed with qualitative content analysis. Three subthemes were combined into one main theme, demonstrating that parents are one important part of a successful PA intervention. The life of an adolescent has many options and demands that make it difficult to prioritize PA. Although parents felt that they were important in supporting their adolescent, a successful PA intervention must have multiple components. Moreover, the parents noted that the intervention had a positive effect upon not only their adolescents’, but also their own PA. Interventions aimed at promoting PA among adolescents should include measures to stimulate parent participation, have an empowerment approach, and preferably be school-based.

  16. Contributions to mathematical analysis and to numerical approximation in plasma physics

    International Nuclear Information System (INIS)

    Besse, N.

    2009-01-01

    The author's scientific works deal with numerical analysis and the simulation of the partial differential equations that intervene in the transport of charged particles and in plasma physics. In the chapters 2 and 3, a reduction of the Vlasov equation is presented, this method is based on the Liouville geometric invariants and it leads to a mathematical model named water-bag model that can be coupled with various equations of the electromagnetic field: the Poisson equation, the quasi-neutral equation or Maxwell equations. In the chapter 3 this reduction method is applied to the Vlasov gyro-kinetic equation to form the gyro-water-bag model. The mathematical analysis of this model produces interesting analytical results such as: threshold instabilities, instability growth rate, transport coefficient and non-linear turbulence mechanisms. Simulations have been performed to study turbulence in magnetized plasmas. In these plasmas occurred numerous instabilities due to the presence of high density and temperature gradients. These instabilities generate turbulence that deteriorates plasma confinement conditions required for thermonuclear fusion. The numerical calculation of turbulent thermal diffusivities is important since confinement time is determined by these transport coefficients. The chapter 4 gathers mathematical analysis issues like convergence or prior knowledge of errors concerning several high-order numerical methods used to solve Vlasov-Poisson or Vlasov-Einstein equation systems as well as the induction equation of an idealistic MHD system. The chapter 5 presents original numerical methods to solve several non-linear Vlasov equations such as Vlasov-Poisswell, Vlasov-Darwin, Vlasov-Maxwell and Vlasov-gyrokinetic that are involved either in inertial fusion or in magnetic confinement fusion

  17. "Physically-based" numerical experiment to determine the dominant hillslope processes during floods?

    Science.gov (United States)

    Gaume, Eric; Esclaffer, Thomas; Dangla, Patrick; Payrastre, Olivier

    2016-04-01

    saturated hillslope leading to a constant discharge over several days. Some ingredients are clearly missing in the proposed model to reproduce hydrologically sensible responses. Heterogeneities are necessary to generate a variety of residence times and especially preferential flows must clearly be present to generate the fast component of hillslope responses. The importance of preferential flows in hillslope hydrology has been confirmed since this reported failure by several hillslope field experiments. We let also the readers draw their own conclusions about the numerous numerical models, that look very much alike the model proposed here, even if generally much more simplified, but representing the watersheds as much too homogeneous neglecting heterogeneities and preferential flows and pretending to be "physically based"…

  18. Three-dimensional direct numerical simulation of electromagnetically driven multiscale shallow layer flows: Numerical modeling and physical properties

    Science.gov (United States)

    Lardeau, Sylvain; Ferrari, Simone; Rossi, Lionel

    2008-12-01

    Three-dimensional (3D) direct numerical simulations of a flow driven by multiscale electromagnetic forcing are performed in order to reproduce with maximum accuracy the quasi-two-dimensional (2D) flow generated by the same multiscale forcing in the laboratory. The method presented is based on a 3D description of the flow and the electromagnetic forcing. Very good agreements between our simulations and the experiments are found both on velocity and acceleration field, this last comparison being, to our knowledge, done for the first time. Such agreement requires that both experiments and simulations are carefully performed and, more importantly, that the underlying simplification to model the experiments and the multiscale electromagnetic forcing do not introduce significant errors. The results presented in this paper differ significantly from previous 2D direct numerical simulation in which a classical linear Rayleigh friction modeling term was used to mimic the effect of the wall-normal friction. Indeed, purely 2D simulations are found to underestimate the Reynolds number and, due to the dominance of nonhomogeneous bottom friction, lead to the wrong physical mechanism. For the range of conditions presented in this paper, the Reynolds number, defined by the ratio between acceleration and viscous terms, remains the order of unity, and the Hartmann number, defined by the ratio between electromagnetic force terms and viscous terms, is about 2. The main conclusion is that 3D simulations are required to model the (3D) electromagnetic forces and the wall-normal shear. Indeed, even if the flow is quasi-2D in terms of energy, a full 3D approach is required to simulate these shallow layer flows driven by multiscale electromagnetic forcing. In the range of forcing intensity investigated in this paper, these multiscale flows remain quasi-2D, with negligible energy in the wall-normal velocity component. It is also shown that the driving terms are the electromagnetic forcing and

  19. Measures of component importance in repairable multistate systems—a numerical study

    International Nuclear Information System (INIS)

    Natvig, Bent; Huseby, Arne B.; Reistadbakk, Mads O.

    2011-01-01

    Dynamic and stationary measures of importance of a component in a repairable multistate system are an important part of reliability. For multistate systems little has been published until now on such measures even in the nonrepairable case. According to the Barlow–Proschan type measures a component is important if there is a high probability that a change in the component state causes a change in whether or not the system state is above a given state. On the other hand, the Natvig type measures focus on how a change in the component state affects the expected system uptime and downtime relative to the given system state. In the present paper we first review these measures which can be estimated using advanced simulation methods. Extending earlier work from the binary to the multistate case, a numerical study of these measures is then given for two three component systems, a bridge system and also applied to an offshore oil and gas production system. In the multistate case the importance of a component is calculated separately for each component state. Thus it may happen that a component is very important at one state, and less important, or even irrelevant at another. Unified measures combining the importances for all component states can be obtained by adding up the importance measures for each individual state. According to these unified measures a component can be important relative to a given system state but not to another. It can be seen that if the distributions of the total component times spent in the non-complete failure states for the multistate system and the component lifetimes for the binary system are identical, the Barlow–Proschan measure to the lowest system state simply reduces to the binary version of the measure. The extended Natvig measure, however, does not have this property. This indicates that the latter measure captures more information about the system. - Highlights: ► The paper discusses measures of component importance in

  20. Numerical tools for musical instruments acoustics: analysing nonlinear physical models using continuation of periodic solutions

    OpenAIRE

    Karkar , Sami; Vergez , Christophe; Cochelin , Bruno

    2012-01-01

    International audience; We propose a new approach based on numerical continuation and bifurcation analysis for the study of physical models of instruments that produce self- sustained oscillation. Numerical continuation consists in following how a given solution of a set of equations is modified when one (or several) parameter of these equations are allowed to vary. Several physical models (clarinet, saxophone, and violin) are formulated as nonlinear dynamical systems, whose periodic solution...

  1. The importance of health-related physical fitness

    Directory of Open Access Journals (Sweden)

    Maria Fátima Glaner

    2003-12-01

    Full Text Available Mechanization and automation, swift communication and transport, computer usage and television viewing have reduced the need for vigorous occupations and discouraged involvement in leisure-time recreational activity. Studies have reported that there is a causal relationship between the risk of chronic disease incidence and mortality and physical activity and/or physical fi tness. Therefore, the aim of this review is to summarize and synthesize the association between health-related physical fi tness (aerobic endurance, fl exibility, strength/ endurance, body fat and chronic diseases. The papers reviewed demonstrate that higher and moderate levels of aerobic endurance, fl exibility, muscular strength/endurance, and desirable body fat levels, are very important for promoting health at all ages, and to avoid early development of chronic diseases. RESUMO A mecanização e a automação, o transporte e a comunicação rápidos, o uso do computador e da televisão têm diminuído atividades vigorosas, inclusive no tempo livre. Estudos reportam que a relação entre o risco de incidência de doenças crônico-degenerativas e a atividade física e/ou a aptidão física é causal. Portanto, o objetivo desta revisão é resumir e sintetizar a associação entre aptidão física relacionada à saúde (aptidão cardiorrespiratória, fl exibilidade, força/resistência muscular e gordura corporal e as doenças crônicodegenerativas. Os estudos mostram que altos e moderados níveis de aptidão cardiorrespiratória, fl exibilidade, força/resistência muscular, e um nível adequado de gordura são muito importantes para promover a saúde em todas idades, bem como evitar o desenvolvimento precoce de doenças crônico-degenerativas.

  2. Research on numerical simulation technology about regional important pollutant diffusion of haze

    Science.gov (United States)

    Du, Boying; Ma, Yunfeng; Li, Qiangqiang; Wang, Qi; Hu, Qiongqiong; Bian, Yushan

    2018-02-01

    In order to analyze the formation of haze in Shenyang and the factors that affect the diffusion of pollutants, the simulation experiment adopted in this paper is based on the numerical model of WRF/CALPUFF coupling. Simulation experiment was conducted to select PM10 of Shenyang City in the period from March 1 to 8, and the PM10 in the regional important haze was simulated. The survey was conducted with more than 120 enterprises section the point of the emission source of this experiment. The contrastive data were analyzed with 11 air quality monitoring points, and the simulation results were compared. Analyze the contribution rate of each typical enterprise to the air quality, verify the correctness of the simulation results, and then use the model to establish the prediction model.

  3. Social Support and Physical Health: The Importance of Belonging.

    Science.gov (United States)

    Hale, Cara J.; Hannum, James W.; Espelage, Dorothy L.

    2005-01-01

    Social support is a multifaceted construct recognized as a significant predictor of physical health. In this study, the authors examined several support domains simultaneously in a sample of 247 college students to determine their unique prediction of physical health perceptions and physical symptoms. They also examined gender differences across…

  4. Importance of Health-Related Fitness Knowledge to Increasing Physical Activity and Physical Fitness

    Science.gov (United States)

    Ferkel, Rick C.; Judge, Lawrence W.; Stodden, David F.; Griffin, Kent

    2014-01-01

    Physical inactivity is expanding across all ages in the United States. Research has documented a deficiency in health-related fitness knowledge (HRFK) among elementary- through college-aged students. The need for a credible and reliable resource that provides research-based information regarding the importance of HRFK is significant. The purpose…

  5. Supernova feedback in numerical simulations of galaxy formation: separating physics from numerics

    Science.gov (United States)

    Smith, Matthew C.; Sijacki, Debora; Shen, Sijing

    2018-04-01

    While feedback from massive stars exploding as supernovae (SNe) is thought to be one of the key ingredients regulating galaxy formation, theoretically it is still unclear how the available energy couples to the interstellar medium and how galactic scale outflows are launched. We present a novel implementation of six sub-grid SN feedback schemes in the moving-mesh code AREPO, including injections of thermal and/or kinetic energy, two parametrizations of delayed cooling feedback and a `mechanical' feedback scheme that injects the correct amount of momentum depending on the relevant scale of the SN remnant resolved. All schemes make use of individually time-resolved SN events. Adopting isolated disk galaxy setups at different resolutions, with the highest resolution runs reasonably resolving the Sedov-Taylor phase of the SN, we aim to find a physically motivated scheme with as few tunable parameters as possible. As expected, simple injections of energy overcool at all but the highest resolution. Our delayed cooling schemes result in overstrong feedback, destroying the disk. The mechanical feedback scheme is efficient at suppressing star formation, agrees well with the Kennicutt-Schmidt relation and leads to converged star formation rates and galaxy morphologies with increasing resolution without fine tuning any parameters. However, we find it difficult to produce outflows with high enough mass loading factors at all but the highest resolution, indicating either that we have oversimplified the evolution of unresolved SN remnants, require other stellar feedback processes to be included, require a better star formation prescription or most likely some combination of these issues.

  6. Component-oriented approach to the development and use of numerical models in high energy physics

    International Nuclear Information System (INIS)

    Amelin, N.S.; Komogorov, M.Eh.

    2002-01-01

    We discuss the main concepts of a component approach to the development and use of numerical models in high energy physics. This approach is realized as the NiMax software system. The discussed concepts are illustrated by numerous examples of the system user session. In appendix chapter we describe physics and numerical algorithms of the model components to perform simulation of hadronic and nuclear collisions at high energies. These components are members of hadronic application modules that have been developed with the help of the NiMax system. Given report is served as an early release of the NiMax manual mainly for model component users

  7. XVI 'Jacques-Louis Lions' Spanish-French School on Numerical Simulation in Physics and Engineering

    CERN Document Server

    Roldán, Teo; Torrens, Juan

    2016-01-01

    This book presents lecture notes from the XVI ‘Jacques-Louis Lions’ Spanish-French School on Numerical Simulation in Physics and Engineering, held in Pamplona (Navarra, Spain) in September 2014. The subjects covered include: numerical analysis of isogeometric methods, convolution quadrature for wave simulations, mathematical methods in image processing and computer vision, modeling and optimization techniques in food processes, bio-processes and bio-systems, and GPU computing for numerical simulation. The book is highly recommended to graduate students in Engineering or Science who want to focus on numerical simulation, either as a research topic or in the field of industrial applications. It can also benefit senior researchers and technicians working in industry who are interested in the use of state-of-the-art numerical techniques in the fields addressed here. Moreover, the book can be used as a textbook for master courses in Mathematics, Physics, or Engineering.

  8. Importance of questionnaire context for a physical activity question.

    Science.gov (United States)

    Jørgensen, M E; Sørensen, M R; Ekholm, O; Rasmussen, N K

    2013-10-01

    Adequate information about physical activity habits is essential for surveillance, implementing, and evaluating public health initiatives in this area. Previous studies have shown that question order and differences in wording result in systematic differences in people's responses to questionnaires; however, this has never been shown for physical activity questions. The aim was to study the influence of different formulations and question order on self-report physical activity in a population-based health interview survey. Four samples of each 1000 adults were drawn at random from the National Person Register. A new question about physical activity was included with minor differences in formulations in samples 1-3. Furthermore, the question in sample 2 was included in sample 4 but was placed in the end of the questionnaire. The mean time spent on moderate physical activity varied between the four samples from 57 to 100 min/day. Question order was associated with the reported number of minutes spent on moderate-intensity physical activity and with prevalence of meeting the recommendation, whereas physical inactivity was associated with the differences in formulation of the question. Questionnaire context influences the way people respond to questions about physical activity significantly and should be tested systematically in validation studies of physical activity questionnaires. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Awareness and habit: important factors in physical activity in children

    NARCIS (Netherlands)

    Kremers, S.P.J.; Dijkman, M.A.M.; de Meij, J.S.B.; Jurg, M.E.; Brug, J.

    2008-01-01

    Purpose - The purpose of this paper is to gain insight into the extent to which Dutch children are aware of their own physical activity level, and to what extent children's physical activity is habitual. Special attention was paid to the potential moderating effect of "awareness" and "habit

  10. Importance of questionnaire context for a physical activity question

    DEFF Research Database (Denmark)

    Jørgensen, M. E.; Sørensen, Mette Rosenlund; Ekholm, O.

    2013-01-01

    ; however, this has never been shown for physical activity questions. The aim was to study the influence of different formulations and question order on self-report physical activity in a population-based health interview survey. Four samples of each 1000 adults were drawn at random from the National Person......Adequate information about physical activity habits is essential for surveillance, implementing, and evaluating public health initiatives in this area. Previous studies have shown that question order and differences in wording result in systematic differences in people's responses to questionnaires...... Register. A new question about physical activity was included with minor differences in formulations in samples 1–3. Furthermore, the question in sample 2 was included in sample 4 but was placed in the end of the questionnaire. The mean time spent on moderate physical activity varied between the four...

  11. On physical and numerical instabilities arising in simulations of non-stationary radiatively cooling shocks

    Science.gov (United States)

    Badjin, D. A.; Glazyrin, S. I.; Manukovskiy, K. V.; Blinnikov, S. I.

    2016-06-01

    We describe our modelling of the radiatively cooling shocks and their thin shells with various numerical tools in different physical and calculational setups. We inspect structure of the dense shell, its formation and evolution, pointing out physical and numerical factors that sustain its shape and also may lead to instabilities. We have found that under certain physical conditions, the circular shaped shells show a strong bending instability and successive fragmentation on Cartesian grids soon after their formation, while remain almost unperturbed when simulated on polar meshes. We explain this by physical Rayleigh-Taylor-like instabilities triggered by corrugation of the dense shell surfaces by numerical noise. Conditions for these instabilities follow from both the shell structure itself and from episodes of transient acceleration during re-establishing of dynamical pressure balance after sudden radiative cooling onset. They are also easily excited by physical perturbations of the ambient medium. The widely mentioned non-linear thin shell instability, in contrast, in tests with physical perturbations is shown to have only limited chances to develop in real radiative shocks, as it seems to require a special spatial arrangement of fluctuations to be excited efficiently. The described phenomena also set new requirements on further simulations of the radiatively cooling shocks in order to be physically correct and free of numerical artefacts.

  12. Second-order coupling of numerical and physical wave tanks for 2D irregular waves. Part I: Formulation, implementation and numerical properties

    DEFF Research Database (Denmark)

    Yang, Zhiwen; Liu, Shuxue; Bingham, Harry B.

    2014-01-01

    In this series of two papers, we report on the irregular wave extension of the second-order coupling theory of numerical and physical wave model described in [Z. Yang, S. Liu, H.B. Bingham and J. Li. Second-order theory for coupling numerical and physical wave tanks: Derivation, evaluation...

  13. Numerical Feynman integrals with physically inspired interpolation: Faster convergence and significant reduction of computational cost

    Directory of Open Access Journals (Sweden)

    Nikesh S. Dattani

    2012-03-01

    Full Text Available One of the most successful methods for calculating reduced density operator dynamics in open quantum systems, that can give numerically exact results, uses Feynman integrals. However, when simulating the dynamics for a given amount of time, the number of time steps that can realistically be used with this method is always limited, therefore one often obtains an approximation of the reduced density operator at a sparse grid of points in time. Instead of relying only on ad hoc interpolation methods (such as splines to estimate the system density operator in between these points, I propose a method that uses physical information to assist with this interpolation. This method is tested on a physically significant system, on which its use allows important qualitative features of the density operator dynamics to be captured with as little as two time steps in the Feynman integral. This method allows for an enormous reduction in the amount of memory and CPU time required for approximating density operator dynamics within a desired accuracy. Since this method does not change the way the Feynman integral itself is calculated, the value of the density operator approximation at the points in time used to discretize the Feynamn integral will be the same whether or not this method is used, but its approximation in between these points in time is considerably improved by this method. A list of ways in which this proposed method can be further improved is presented in the last section of the article.

  14. On importance of dark matter for LHC physics

    International Nuclear Information System (INIS)

    Bednyakov, V.A.

    2000-01-01

    The aim of this paper is to attract attention of the LHC high-energy physics community to non-accelerator, low-energy experiments that are also very sensitive to new physics. This example concerns the search for supersymmetric dark matter particles. It is shown that non-observation of the SUSY dark matter candidates with a high-accuracy detector can exclude large domains of the MSSM parameter space and, in particular, can make especially desirable collider search for light SUSY charged Higgs boson

  15. Tsunami-induced boulder transport - combining physical experiments and numerical modelling

    Science.gov (United States)

    Oetjen, Jan; Engel, Max; May, Simon Matthias; Schüttrumpf, Holger; Brueckner, Helmut; Prasad Pudasaini, Shiva

    2016-04-01

    Coasts are crucial areas for living, economy, recreation, transportation, and various sectors of industry. Many of them are exposed to high-energy wave events. With regard to the ongoing population growth in low-elevation coastal areas, the urgent need for developing suitable management measures, especially for hazards like tsunamis, becomes obvious. These measures require supporting tools which allow an exact estimation of impact parameters like inundation height, inundation area, and wave energy. Focussing on tsunamis, geological archives can provide essential information on frequency and magnitude on a longer time scale in order to support coastal hazard management. While fine-grained deposits may quickly be altered after deposition, multi-ton coarse clasts (boulders) may represent an information source on past tsunami events with a much higher preservation potential. Applying numerical hydrodynamic coupled boulder transport models (BTM) is a commonly used approach to analyse characteristics (e.g. wave height, flow velocity) of the corresponding tsunami. Correct computations of tsunamis and the induced boulder transport can provide essential event-specific information, including wave heights, runup and direction. Although several valuable numerical models for tsunami-induced boulder transport exist (e. g. Goto et al., 2007; Imamura et al., 2008), some important basic aspects of both tsunami hydrodynamics and corresponding boulder transport have not yet been entirely understood. Therefore, our project aims at these questions in four crucial aspects of boulder transport by a tsunami: (i) influence of sediment load, (ii) influence of complex boulder shapes other than idealized rectangular shapes, (iii) momentum transfers between multiple boulders, and (iv) influence of non-uniform bathymetries and topographies both on tsunami and boulder. The investigation of these aspects in physical experiments and the correct implementation of an advanced model is an urgent need

  16. Modelling of cardiovascular system: development of a hybrid (numerical-physical) model.

    Science.gov (United States)

    Ferrari, G; Kozarski, M; De Lazzari, C; Górczyńska, K; Mimmo, R; Guaragno, M; Tosti, G; Darowski, M

    2003-12-01

    Physical models of the circulation are used for research, training and for testing of implantable active and passive circulatory prosthetic and assistance devices. However, in comparison with numerical models, they are rigid and expensive. To overcome these limitations, we have developed a model of the circulation based on the merging of a lumped parameter physical model into a numerical one (producing therefore a hybrid). The physical model is limited to the barest essentials and, in this application, developed to test the principle, it is a windkessel representing the systemic arterial tree. The lumped parameters numerical model was developed in LabVIEW environment and represents pulmonary and systemic circulation (except the systemic arterial tree). Based on the equivalence between hydraulic and electrical circuits, this prototype was developed connecting the numerical model to an electrical circuit--the physical model. This specific solution is valid mainly educationally but permits the development of software and the verification of preliminary results without using cumbersome hydraulic circuits. The interfaces between numerical and electrical circuits are set up by a voltage controlled current generator and a voltage controlled voltage generator. The behavior of the model is analyzed based on the ventricular pressure-volume loops and on the time course of arterial and ventricular pressures and flow in different circulatory conditions. The model can represent hemodynamic relationships in different ventricular and circulatory conditions.

  17. Visual search for conjunctions of physical and numerical size shows that they are processed independently.

    Science.gov (United States)

    Sobel, Kenith V; Puri, Amrita M; Faulkenberry, Thomas J; Dague, Taylor D

    2017-03-01

    The size congruity effect refers to the interaction between numerical magnitude and physical digit size in a symbolic comparison task. Though this effect is well established in the typical 2-item scenario, the mechanisms at the root of the interference remain unclear. Two competing explanations have emerged in the literature: an early interaction model and a late interaction model. In the present study, we used visual conjunction search to test competing predictions from these 2 models. Participants searched for targets that were defined by a conjunction of physical and numerical size. Some distractors shared the target's physical size, and the remaining distractors shared the target's numerical size. We held the total number of search items fixed and manipulated the ratio of the 2 distractor set sizes. The results from 3 experiments converge on the conclusion that numerical magnitude is not a guiding feature for visual search, and that physical and numerical magnitude are processed independently, which supports a late interaction model of the size congruity effect. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. Physical activity and its importance for the health of elderly

    Directory of Open Access Journals (Sweden)

    Paulina Sztandera

    2017-07-01

    Full Text Available Introduction and aim of the study. World society is aging. In Poland, in 2015 the proportion of older people is almost 23%, and the world is 12%. Forecasts show that by 2050 this proportion will reach 32.7%, the world 22%, and 1 in 5 people will be 60+. The purpose of the study was to analyze the literature of physical activity and its benefits to elderly people’ health. Actual knowledge. The health condition worsens with age, the number of long-term health problems and chronic diseases rising with age. These problems are mainly related to cardiological problems, joint problem and diabetes. The World Health Organization has pointed out that physical activity has measurable effects on the health of the elderly. Summary.From the available literature, there is clearly a positive effect of physical activity on the health of people in the third period of life. Physical activity started in any age will have beneficial health effects associated with improved functional status, improved quality of life and mood.

  19. Physical Activity Plays an Important Role in Body Weight Regulation

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Chaput

    2011-01-01

    Full Text Available Emerging literature highlights the need to incorporate physical activity into every strategy intended to prevent weight gain as well as to maintain weight loss over time. Furthermore, physical activity should be part of any plan to lose weight. The stimulus of exercise provides valuable metabolic adaptations that improve energy and macronutrient balance regulation. A tight coupling between energy intake and energy expenditure has been documented at high levels of physical exercise, suggesting that exercise may improve appetite control. The regular practice of physical activity has also been reported to reduce the risk of stress-induced weight gain. A more personalized approach is recommended when planning exercise programs in a clinical weight loss setting in order to limit the compensatory changes associated to exercise-induced weight loss. With modern environment promoting overeating and sedentary behavior, there is an urgent need for a concerted action including legislative measures to promote healthy active living in order to curb the current epidemic of chronic diseases.

  20. The Importance of Physical Fitness in Academia | Olu | Lwati: A ...

    African Journals Online (AJOL)

    Fitness activities include warm-up and cool-down activities. When these activities are properly done it does not only enhances one's health, alertness, but also promote the mental emotional, physical social and spiritual well-being of an academia. It brings about all round development of other body e.g. agility, strength, ...

  1. Physical and numerical modelling of heat treatment the precipitation-hardening complex-phase steel (CP

    Directory of Open Access Journals (Sweden)

    B. Koczurkiewicz

    2013-01-01

    Full Text Available The article presents the results of physical and numerical modeling of the processes of thermo- plastic treatment of an experimental complex-phase (CP steel. Numerical tests were carried out using a commercial software program, ThermoCalc. Based on the obtained test results, the austenitization temperature was established. Physical modeling was performed using a DIL 805A/D dilatometer and the Gleeble 3800 system. The characteristic temperatures of the steel and the primary austenite grain size were determined. The test pieces were also subjected to metallographic examinations and Vickers hardness tests. The obtained results served for building an actual CCT diagram for the steel tested.

  2. Physics League Across Numerous Countries for Kick-ass Students (PLANCKS)

    Science.gov (United States)

    Haasnoot, Irene

    2016-01-01

    Physics League Across Numerous Countries for Kick-ass Students (PLANCKS) is an international theoretical physics competition for bachelor and master students. The intention of PLANCKS is to increase international collaboration and stimulate the personal development of individual contestants. This is done by organizing a three-day-event which take place every year and is hosted by different countries. Besides the contest, social and scientific activities will be organised, including an opening symposium where leading physicists give lectures to inspire the participants.

  3. Ideas Exchange: "How Important Is Activity in Young Children (Preschool) to a Lifetime of Physical Activity?"

    Science.gov (United States)

    Hushman, GLenn; Morrison, Jaime; Mally, Kristi; McCall, Renee; Corso, Marjorie; Kamla, Jim; Magnotta, John; Chase, Melissa A.; Garrahy, Deborah A.; Lorenzi, David G.; Barnd, Sue

    2009-01-01

    This article presents the opinions of several professionals who were asked: "How important is activity in young children (preschool) to a lifetime of physical activity?" These professionals point out the importance of physical activity to young children.

  4. Numerical tables on physical and chemical analyses of Rhine water 1983

    International Nuclear Information System (INIS)

    1984-01-01

    The numerical tables contain the measuring results of the physical-chemical studies on the Rhine water for the year 1983. The tables are arranged by general parameters, organic matter, eutrophicating substances, anorganic matter, metals, organic micropollution as well as by radioactivity (total alpha- or beta- and T-activity). (MM) [de

  5. High Performance Numerical Computing for High Energy Physics: A New Challenge for Big Data Science

    International Nuclear Information System (INIS)

    Pop, Florin

    2014-01-01

    Modern physics is based on both theoretical analysis and experimental validation. Complex scenarios like subatomic dimensions, high energy, and lower absolute temperature are frontiers for many theoretical models. Simulation with stable numerical methods represents an excellent instrument for high accuracy analysis, experimental validation, and visualization. High performance computing support offers possibility to make simulations at large scale, in parallel, but the volume of data generated by these experiments creates a new challenge for Big Data Science. This paper presents existing computational methods for high energy physics (HEP) analyzed from two perspectives: numerical methods and high performance computing. The computational methods presented are Monte Carlo methods and simulations of HEP processes, Markovian Monte Carlo, unfolding methods in particle physics, kernel estimation in HEP, and Random Matrix Theory used in analysis of particles spectrum. All of these methods produce data-intensive applications, which introduce new challenges and requirements for ICT systems architecture, programming paradigms, and storage capabilities.

  6. Numerical functional integration method for studying the properties of the physical vacuum

    International Nuclear Information System (INIS)

    Lobanov, Yu.Yu.

    1998-01-01

    The new approach to investigate the physical vacuum in quantum theories including its nonperturbative topological structure is discussed. This approach is based on the representation of the matrix element of the evolution operator in Euclidean metrics in a form of the functional integral with a certain measure in the corresponding space and on the use of approximation formulas which we constructed for this kind of integral. No preliminary discretization of space and time is required, as well as no simplifying assumptions like semiclassical approximation, collective excitations, introduction of ''short-time'' propagators, etc. are necessary in this approach. The method allows to use the more preferable deterministic algorithms instead of the traditional stochastic technique. It has been proven that our approach has important advantages over the other known methods, including the higher efficiency of computations. Examples of application of the method to the numerical study of some potential nuclear models and to the computation of the topological susceptibility and the θ-vacua energy are presented. (author)

  7. Evaluation of physics-based numerical modelling for diverse design architecture of perovskite solar cells

    Science.gov (United States)

    Mishra, A. K.; Catalan, Jorge; Camacho, Diana; Martinez, Miguel; Hodges, D.

    2017-08-01

    Solution processed organic-inorganic metal halide perovskite based solar cells are emerging as a new cost effective photovoltaic technology. In the context of increasing the power conversion efficiency (PCE) and sustainability of perovskite solar cells (PSC) devices, we comprehensively analyzed a physics-based numerical modelling for doped and un-doped PSC devices. Our analytics emphasized the role of different charge carrier layers from the view point of interfacial adhesion and its influence on charge extraction rate and charge recombination mechanism. Morphological and charge transport properties of perovskite thin film as a function of device architecture are also considered to investigate the photovoltaic properties of PSC. We observed that photocurrent is dominantly influenced by interfacial recombination process and photovoltage has functional relationship with defect density of perovskite absorption layer. A novel contour mapping method to understand the characteristics of current density-voltage (J-V) curves for each device as a function of perovskite layer thickness provide an important insight about the distribution spectrum of photovoltaic properties. Functional relationship of device efficiency and fill factor with absorption layer thickness are also discussed.

  8. Mathematical and numerical analysis of a few hydrodynamic and kinetic models of plasma physics

    International Nuclear Information System (INIS)

    Buet, C.

    2005-01-01

    My research work deals mainly with the mathematical modelling and the numerical simulation of plasma physics. This document is divided into 3 parts. The first one is a summary of the works done for the numerical solving of collision operators. The common thread of this part is obtaining numerical schemes preserving operators' properties namely physical invariants like mass, momentum and energy, equilibrium states and entropy decrease. These properties are generally checked formally for continuous operators, may give rise to some difficulties for discrete operators. In the second part I present a summary of the works regarding moments methods applied to radiative transfer and the numerical issues dealing with their discretization. The common thread of this part is how to get numerical schemes preserving asymptotic scattering and invariant domains for Lorentz models and also for non-linear telegraph-type equations involved in radiative transfer or electronic plasma. In the third part I present 2 themes linked to collision operators: multi-fluid ionization and the non-existence of linear monotone schemes for some linear parabolic equations

  9. Numerical and spatial cognition of students with physical disabilities and mild intellectual disabilities

    OpenAIRE

    Vidmar, Anja

    2017-01-01

    Mathematics has an important effect on an individual's successfulness and satisfaction in the field of education and life. Numerical and spatial cognition are of crucial importance to successfully master mathematics. If this kind of cognition is poorly developed, it represents one of the most important obstacles to achieving success in the field of mathematics. Students with mild intellectual disabilities are in a worse position already at the starting point of the educational process, as the...

  10. Technogenic Rock Dumps Physical Properties' Prognosis via Results of the Structure Numerical Modeling

    Directory of Open Access Journals (Sweden)

    Markov Sergey

    2017-01-01

    Full Text Available Understanding of internal structure of the technogenic rock dumps (gob dumps is required condition for estimation of using ones as filtration massifs for treatment of mine wastewater. Internal structure of gob piles greatly depends on dumping technology to applying restrictions for use them as filtration massifs. Numerical modelling of gob dumps allows adequately estimate them physical parameters, as a filtration coefficient, density, etc. The gob dumps numerical modelling results given in this article, in particular was examined grain size distribution of determined fractions depend on dump height. Shown, that filtration coefficient is in a nonlinear dependence on amount of several fractions of rock in gob dump. The numerical model adequacy both the gob structure and the dependence of filtration coefficient from gob height acknowledged equality of calculated and real filtration coefficient values. The results of this research can be apply to peripheral dumping technology.

  11. Physical models and numerical methods of the reactor dynamic computer program RETRAN

    International Nuclear Information System (INIS)

    Kamelander, G.; Woloch, F.; Sdouz, G.; Koinig, H.

    1984-03-01

    This report describes the physical models and the numerical methods of the reactor dynamic code RETRAN simulating reactivity transients in Light-Water-Reactors. The neutron-physical part of RETRAN bases on the two-group-diffusion equations which are solved by discretization similar to the TWIGL-method. An exponential transformation is applied and the inner iterations are accelerated by a coarse-mesh-rebalancing procedure. The thermo-hydraulic model approximates the equation of state by a built-in steam-water-table and disposes of options for the calculation of heat-conduction coefficients and heat transfer coefficients. (Author) [de

  12. Physical modelling and numerical simulation of the round-to-square forward extrusion

    DEFF Research Database (Denmark)

    Gouveia, B.P.P.A.; Rodrigues, J.M.C.; Martins, P.A.F.

    2001-01-01

    , and comparisons are made between the numerical predictions and experimental data obtained through the utilisation of physical modelling. Assessment is made in terms of flow pattern and strain distribution for two different cross-sections corresponding to the axial symmetry planes of the three......-dimensional extrusion part. The experimental distribution of strain is determined from the shape change of quadrilateral grids previously printed on the surface of the axial cross-sections of the undeformed billets by means of large deformation square-grid analysis. Good agreement is obtained between physical...

  13. Proceedings of the conference on numerical methods in high temperature physics

    International Nuclear Information System (INIS)

    Alcouffe, R.E.; Holm, D.D.; O'Rourke, P.J.

    1988-11-01

    These proceedings contain full papers presented at the Los Alamos Conference on High Temperature Physics. This conference discussed many aspects of high temperature physics including hydrodynamics, radiation and particle transport and some computational issues important for efficient calculations. The meetings was held between researchers from Los Alamos and the French Commissariat a L'Energy Atomique

  14. Proceedings of the conference on numerical methods in high temperature physics

    Energy Technology Data Exchange (ETDEWEB)

    Alcouffe, R.E.; Holm, D.D.; O' Rourke, P.J. (comps.)

    1988-11-01

    These proceedings contain full papers presented at the Los Alamos Conference on High Temperature Physics. This conference discussed many aspects of high temperature physics including hydrodynamics, radiation and particle transport and some computational issues important for efficient calculations. The meetings was held between researchers from Los Alamos and the French Commissariat a L'Energy Atomique (CEA).

  15. Subsolutions of an Isaacs Equation and Efficient Schemes for Importance Sampling: Examples and Numerics

    National Research Council Canada - National Science Library

    Dupuis, Paul; Wang, Hui

    2005-01-01

    It has been established that importance sampling algorithms for estimating rare-event probabilities are intimately connected with two-person zero-sum differential games and the associated Isaacs equation...

  16. Integrated Numerical Experiments (INEX) and the Free-Electron Laser Physical Process Code (FELPPC)

    International Nuclear Information System (INIS)

    Thode, L.E.; Chan, K.C.D.; Schmitt, M.J.; McKee, J.; Ostic, J.; Elliott, C.J.; McVey, B.D.

    1990-01-01

    The strong coupling of subsystem elements, such as the accelerator, wiggler, and optics, greatly complicates the understanding and design of a free electron laser (FEL), even at the conceptual level. To address the strong coupling character of the FEL the concept of an Integrated Numerical Experiment (INEX) was proposed. Unique features of the INEX approach are consistency and numerical equivalence of experimental diagnostics. The equivalent numerical diagnostics mitigates the major problem of misinterpretation that often occurs when theoretical and experimental data are compared. The INEX approach has been applied to a large number of accelerator and FEL experiments. Overall, the agreement between INEX and the experiments is very good. Despite the success of INEX, the approach is difficult to apply to trade-off and initial design studies because of the significant manpower and computational requirements. On the other hand, INEX provides a base from which realistic accelerator, wiggler, and optics models can be developed. The Free Electron Laser Physical Process Code (FELPPC) includes models developed from INEX, provides coupling between the subsystem models, and incorporates application models relevant to a specific trade-off or design study. In other words, FELPPC solves the complete physical process model using realistic physics and technology constraints. Because FELPPC provides a detailed design, a good estimate for the FEL mass, cost, and size can be made from a piece-part count of the FEL. FELPPC requires significant accelerator and FEL expertise to operate. The code can calculate complex FEL configurations including multiple accelerator and wiggler combinations

  17. Understanding the Importance, Dimensions and Settings for Developing Children’s Physical Activity Behaviour

    OpenAIRE

    Hyndman, Brendon

    2015-01-01

    Promotion of regular physical activity during childhood within schools, home and community settings is important as childhood forms the foundation for physical activity habits that can track into adulthood. Despite childhood being a crucial period for developing physical activity behaviour, there is a limited understanding of the physical activity behaviours of school-aged children. The aim of this research report is to facilitate understanding of children’s physical activity behaviours by ou...

  18. Computer programs of information processing of nuclear physical methods as a demonstration material in studying nuclear physics and numerical methods

    Science.gov (United States)

    Bateev, A. B.; Filippov, V. P.

    2017-01-01

    The principle possibility of using computer program Univem MS for Mössbauer spectra fitting as a demonstration material at studying such disciplines as atomic and nuclear physics and numerical methods by students is shown in the article. This program is associated with nuclear-physical parameters such as isomer (or chemical) shift of nuclear energy level, interaction of nuclear quadrupole moment with electric field and of magnetic moment with surrounded magnetic field. The basic processing algorithm in such programs is the Least Square Method. The deviation of values of experimental points on spectra from the value of theoretical dependence is defined on concrete examples. This value is characterized in numerical methods as mean square deviation. The shape of theoretical lines in the program is defined by Gaussian and Lorentzian distributions. The visualization of the studied material on atomic and nuclear physics can be improved by similar programs of the Mössbauer spectroscopy, X-ray Fluorescence Analyzer or X-ray diffraction analysis.

  19. Numerical simulation as an important tool in developing novel hypersonic technologies

    International Nuclear Information System (INIS)

    Bocharov, A N; Bityurin, V A; Medin, S A; Naumov, N D; Petrovskiy, V P; Ryabkov, O I; Tatarinov, A V; Teplyakov, I O; Fortov, V E; Balakirev, B A; Golovin, N N; Solomonov, Yu S; Tikhonov, A A; Gryaznov, V K; Iosilevskiy, I L; Evstigneev, N M

    2015-01-01

    Development of novel hypersonic technologies necessarily requires the development of methods for analyzing a motion of hypervelocity vehicles. This paper could be considered as the initial stage in developing of complex computational model for studying flows around hypervelocity vehicles of arbitrary shape. Essential part of the model is a solution to three-dimensional transport equations for mass, momentum and energy for the medium in the state of both LTE (local thermodynamic equilibrium) and non-LTE. One of the primary requirements to the developed model is the realization on the modern heterogeneous computer systems including both CPU and GPU. The paper presents the first results on numerical simulation of hypersonic flow. The first problem considered is three-dimensional flow around curved body under angle of attack. The performance of heterogeneous 4-GPU computer system is tested. The second problem highlights the capabilities of the developed model to study heat and mass transfer problems. Namely, interior heat problem is considered which takes into account ablation of thermal protection system and variation of the surface shape of the vehicle. (paper)

  20. NEESROCK: A Physical and Numerical Modeling Investigation of Seismically Induced Rock-Slope Failure

    Science.gov (United States)

    Applegate, K. N.; Wartman, J.; Keefer, D. K.; Maclaughlin, M.; Adams, S.; Arnold, L.; Gibson, M.; Smith, S.

    2013-12-01

    Worldwide, seismically induced rock-slope failures have been responsible for approximately 30% of the most significant landslide catastrophes of the past century. They are among the most common, dangerous, and still today, least understood of all seismic hazards. Seismically Induced Rock-Slope Failure: Mechanisms and Prediction (NEESROCK) is a major research initiative that fully integrates physical modeling (geotechnical centrifuge) and advanced numerical simulations (discrete element modeling) to investigate the fundamental mechanisms governing the stability of rock slopes during earthquakes. The research is part of the National Science Foundation-supported Network for Earthquake Engineering Simulation Research (NEES) program. With its focus on fractures and rock materials, the project represents a significant departure from the traditional use of the geotechnical centrifuge for studying soil, and pushes the boundaries of physical modeling in new directions. In addition to advancing the fundamental understanding of the rock-slope failure process under seismic conditions, the project is developing improved rock-slope failure assessment guidelines, analysis procedures, and predictive tools. Here, we provide an overview of the project, present experimental and numerical modeling results, discuss special considerations for the use of synthetic rock materials in physical modeling, and address the suitability of discrete element modeling for simulating the dynamic rock-slope failure process.

  1. Development of physical and numerical techniques of Alanine/EPR dosimetry in radiotherapy

    International Nuclear Information System (INIS)

    Castro, F.; Ponte, F.; Pereira, L.

    2006-01-01

    In this work, a set of 50 alanine dosimeters has been used in a radiotherapy context, simulating a two-dimensional treatment in a non-overlapping dosimeter configuration. The dose is reconstructed from physical and numerical simulation of the electron paramagnetic resonance signal, calculating the spin density. Thus, it can be used to better adjust the error in the calibration curve to give a final accuracy of <0.03 Gy. A complete set of experimental test parameters have been used with a standard dosimeter in order to obtain the best analysis configuration. These results indicate that for a conventional treatment of some hundreds of mGy, this method can be useful with a correct signal validation. A numerical test and fitting software has been developed. The general use of alanine/electron paramagnetic resonance dosimetry in radiotherapy context is discussed. (authors)

  2. Numerical methods for the simulation of particle generated electromagnetic fields in acclerator physics

    International Nuclear Information System (INIS)

    Lau, T.

    2006-01-01

    In this work modifications of the classical Particle-In-Cell method for the solution of the Maxwell-Vlasov equations are investigated with respect to their application in particle accelerator physics. The aim of the work is to find modifications of the method which minimize and under certain conditions even eliminate the numerical dispersion effect along the beam axis in the numerical solution of Maxwell's equations. This is achieved by the development of dedicated time-integration methods for the Finite Integration Technique and two Finite Volume Methods. The methods are theoretically investigated regarding the conservation of a discrete energy and the existence of a discrete continuity equation. Finally, some of the methods are applied to the simulation of a high frequency rf-gun. (orig.)

  3. Children and adults use physical size and numerical alliances in third-party judgments of dominance

    Directory of Open Access Journals (Sweden)

    Stella F Lourenco

    2016-01-01

    Full Text Available Humans and other social animals interact regularly with conspecifics as part of affiliative groups. Many of these interactions are cooperative, but many others involve competition for resources. Competitive exchanges are often resolved on the basis of dominance relationships, with higher-ranking individuals receiving priority access to desired goods. Although no single cue can establish permanent dominance relationships, there are some cues that predict dominance fairly reliably across context. In the present study, we focused on two such cues relevant to competing groups: (i the physical sizes of individual members, and (ii their relative number. Using a social competition task, we examined whether, and how, preschool-aged children and adults used differences in physical size and numerical alliances to judge which of two groups should prevail in a competitive exchange for a desired object. These judgments were made when either physical size or number differed between groups (Experiment 1, and when both were available but pitted against each other (Experiments 1 and 2. Our findings revealed that by 3 years of age, humans use multiple perceptible cues in third-party judgments of dominance. Our findings also revealed that 3-year-olds, like adults, weighted these cues flexibly according to the additional factor of overall group size, with the physical sizes of individuals determining dominance in smaller groups (e.g., 2 vs. 4 characters and the relative number of individuals determining dominance in larger groups (e.g., 15 vs. 30 characters. Taken together, our findings suggest that a basic formula for determining dominance in competitive exchanges, which weights physical size of individuals and numerical alliances as a function of overall group size, is available to young children and appears fairly stable through to adulthood.

  4. Children and Adults Use Physical Size and Numerical Alliances in Third-Party Judgments of Dominance.

    Science.gov (United States)

    Lourenco, Stella F; Bonny, Justin W; Schwartz, Bari L

    2015-01-01

    Humans and other social animals interact regularly with conspecifics as part of affiliative groups. Many of these interactions are cooperative, but many others involve competition for resources. Competitive exchanges are often resolved on the basis of dominance relationships, with higher-ranking individuals receiving priority access to desired goods. Although no single cue can establish permanent dominance relationships, there are some cues that predict dominance fairly reliably across context. In the present study, we focused on two such cues relevant to competing groups: (i) the physical sizes of individual members, and (ii) their relative number. Using a social competition task, we examined whether, and how, preschool-aged children and adults used differences in physical size and numerical alliances to judge which of two groups should prevail in a competitive exchange for a desired object. These judgments were made when either physical size or number differed between groups (Experiment 1), and when both were available but pitted against each other (Experiments 1 and 2). Our findings revealed that by 3 years of age, humans use multiple perceptible cues in third-party judgments of dominance. Our findings also revealed that 3-year-olds, like adults, weighted these cues flexibly according to the additional factor of overall group size, with the physical sizes of individuals determining dominance in smaller groups (e.g., 2 vs. 4 characters) and the relative number of individuals determining dominance in larger groups (e.g., 15 vs. 30 characters). Taken together, our findings suggest that a basic formula for determining dominance in competitive exchanges, which weights physical size of individuals and numerical alliances as a function of overall group size, is available to young children and appears fairly stable through to adulthood.

  5. Numerical simulation and analysis for low-frequency rock physics measurements

    Science.gov (United States)

    Dong, Chunhui; Tang, Genyang; Wang, Shangxu; He, Yanxiao

    2017-10-01

    In recent years, several experimental methods have been introduced to measure the elastic parameters of rocks in the relatively low-frequency range, such as differential acoustic resonance spectroscopy (DARS) and stress-strain measurement. It is necessary to verify the validity and feasibility of the applied measurement method and to quantify the sources and levels of measurement error. Relying solely on the laboratory measurements, however, we cannot evaluate the complete wavefield variation in the apparatus. Numerical simulations of elastic wave propagation, on the other hand, are used to model the wavefield distribution and physical processes in the measurement systems, and to verify the measurement theory and analyze the measurement results. In this paper we provide a numerical simulation method to investigate the acoustic waveform response of the DARS system and the quasi-static responses of the stress-strain system, both of which use axisymmetric apparatus. We applied this method to parameterize the properties of the rock samples, the sample locations and the sensor (hydrophone and strain gauges) locations and simulate the measurement results, i.e. resonance frequencies and axial and radial strains on the sample surface, from the modeled wavefield following the physical experiments. Rock physical parameters were estimated by inversion or direct processing of these data, and showed a perfect match with the true values, thus verifying the validity of the experimental measurements. Error analysis was also conducted for the DARS system with 18 numerical samples, and the sources and levels of error are discussed. In particular, we propose an inversion method for estimating both density and compressibility of these samples. The modeled results also showed fairly good agreement with the real experiment results, justifying the effectiveness and feasibility of our modeling method.

  6. Perceptions of Important Characteristics of Physical Activity Facilities: Implications for Engagement in Walking, Moderate and Vigorous Physical Activity.

    Science.gov (United States)

    Heinrich, Katie M; Haddock, Christopher K; Jitnarin, Natinee; Hughey, Joseph; Berkel, LaVerne A; Poston, Walker S C

    2017-01-01

    Although few United States adults meet physical activity recommendations, those that do are more likely to access to physical activity facilities. Additionally, vigorous exercisers may be more likely to utilize a nearby physical activity facility, while light-to-moderate exercisers are less likely to do so. However, it is unclear what characteristics of those facilities are most important as well as how those characteristics are related to activity intensity. This study examined relationships between self-reported leisure-time physical activities and the use of and perceived characteristics of physical activity facilities. Data were from a cross-sectional study in a major metropolitan area. Participants ( N  = 582; ages 18-74, mean age = 45 ± 14.7 years) were more likely to be female (69.9%), Caucasian (65.6%), married (51.7%), and have some college education (72.8%). Household surveys queried leisure-time physical activity, regular physical activity facility use, and importance ratings for key facility characteristics. Leisure-time physical activity recommendations were met by 41.0% of participants and 50.9% regularly used a physical activity facility. Regular facility use was positively associated with meeting walking ( p  = 0.036), moderate ( p  importance on facility quality ( p  = 0.022), variety of physical activity options offered ( p  = 0.003), and availability of special equipment and resources ( p  = 0.01). The facility characteristics of low or free cost ( p  = 0.02) and offering childcare ( p  = 0.028) were barriers for walking, and being where friends and family like to go were barriers for moderate leisure-time physical activity ( p  = 0.013). Findings offer insights for structuring interventions using the social ecological model as well as for improving existing physical activity facilities.

  7. Physical modeling and numerical simulation of V-die forging ingot with central void

    DEFF Research Database (Denmark)

    Christiansen, Peter; Hattel, Jesper Henri; Bay, Niels

    2014-01-01

    Numerical simulation and physical modeling performed on small-scale ingots made from pure lead, having a hole drilled through their centerline to mimic porosity, are utilized to characterize the deformation mechanics of a single open die forging compression stage and to identify the influence...... of the lower V-die angle on porosity closure and forging load requirements of large cast ingots. Results show that a lower V-die angle of 120 provides the best closure of centerline porosity without demanding the highest forging loads or developing unreasonably asymmetric shapes that may create difficulties...... in multi-stage open die forging procedures....

  8. General meeting. Technical reunion: the numerical and experimental simulation applied to the Reactor Physics

    International Nuclear Information System (INIS)

    2001-10-01

    The SFEN (French Society on Nuclear Energy), organized the 18 october 2001 at Paris, a technical day on the numerical and experimental simulation, applied to the reactor Physics. Nine aspects were discussed, giving a state of the art in the domain:the french nuclear park; the future technology; the controlled thermonuclear fusion; the new organizations and their implications on the research and development programs; Framatome-ANP markets and industrial code packages; reactor core simulation at high temperature; software architecture; SALOME; DESCARTES. (A.L.B.)

  9. Numerical Simulation of Measurements during the Reactor Physical Startup at Unit 3 of Rostov NPP

    Science.gov (United States)

    Tereshonok, V. A.; Kryakvin, L. V.; Pitilimov, V. A.; Karpov, S. A.; Kulikov, V. I.; Zhylmaganbetov, N. M.; Kavun, O. Yu.; Popykin, A. I.; Shevchenko, R. A.; Shevchenko, S. A.; Semenova, T. V.

    2017-12-01

    The results of numerical calculations and measurements of some reactor parameters during the physical startup tests at unit 3 of Rostov NPP are presented. The following parameters are considered: the critical boron acid concentration and the currents from ionization chambers (IC) during the scram system efficiency evaluation. The scram system efficiency was determined using the inverse point kinetics equation with the measured and simulated IC currents. The results of steady-state calculations of relative power distribution and efficiency of the scram system and separate groups of control rods of the control and protection system are also presented. The calculations are performed using several codes, including precision ones.

  10. Physical and numerical modeling of hydrophysical proceses on the site of underwater pipelines

    Science.gov (United States)

    Garmakova, M. E.; Degtyarev, V. V.; Fedorova, N. N.; Shlychkov, V. A.

    2018-03-01

    The paper outlines issues related to ensuring the exploitation safety of underwater pipelines that are at risk of accidents. The performed research is based on physical and mathematical modeling of local bottom erosion in the area of pipeline location. The experimental studies were performed on the basis of the Hydraulics Laboratory of the Department of Hydraulic Engineering Construction, Safety and Ecology of NSUACE (Sibstrin). In the course of physical experiments it was revealed that the intensity of the bottom soil reforming depends on the deepening of the pipeline. The ANSYS software has been used for numerical modeling. The process of erosion of the sandy bottom was modeled under the pipeline. Comparison of computational results at various mass flow rates was made.

  11. Recommended numerical nuclear physics data for cutting-edge nuclear technology applications

    International Nuclear Information System (INIS)

    Ganesan, S.; Srivenkatesan, R.; Anek Kumar; Murthy, C.S.R.C.; Dhekne, P.S.

    2005-01-01

    This paper introduces some aspects of online nuclear data services at Mumbai as part of today's technology of sharing knowledge of the recommended numerical nuclear physics data for nuclear applications. The physics foundation for cutting-edge technology applications is significantly strengthened by such knowledge generation and sharing techniques. A BARC server is presently mirroring the nuclear data services of the IAEA, Vienna. The users can get all the nuclear data information much faster from the BARC nuclear data mirror website that is now fully operational. The nuclear community is encouraged to develop the habit of accessing the website for recommended values of nuclear data for use in research and applications. The URL is: www-nds.indcentre.org.in (author)

  12. Physical, experimental and numerical study of fundamental mechanisms involved in two-phase flows

    International Nuclear Information System (INIS)

    Mathieu, Benoit

    2003-01-01

    In this work, small-scale phenomena in two-phase flows with phase change are studied. First, some fundamental phenomena related to the heat and mass transfer at small scale are recalled. A physical model is then built in order to describe moving contact lines with phase change. In the second part, a numerical simulation method is built, that is able to describe the growth of a single bubble on a heated wall. Compared to existing methods, major improvements are obtained with respect to the conservation of the mass, the spurious currents related to interfacial forces and the physical description of the contact lines. Finally, an experimental investigation of the singular heat and mass transfer at the contact line is carried out. Preliminary results obtained on a simplified configuration are presented. (author) [fr

  13. An advanced three-phase physical, experimental and numerical method for tsunami induced boulder transport

    Science.gov (United States)

    Oetjen, Jan; Engel, Max; Prasad Pudasaini, Shiva; Schüttrumpf, Holger; Brückner, Helmut

    2017-04-01

    Coasts around the world are affected by high-energy wave events like storm surges or tsunamis depending on their regional climatological and geological settings. By focusing on tsunami impacts, we combine the abilities and experiences of different scientific fields aiming at improved insights of near- and onshore tsunami hydrodynamics. We investigate the transport of coarse clasts - so called boulders - due to tsunami impacts by a multi-methodology approach of numerical modelling, laboratory experiments, and sedimentary field records. Coupled numerical hydrodynamic and boulder transport models (BTM) are widely applied for analysing the impact characteristics of the transport by tsunami, such as wave height and flow velocity. Numerical models able to simulate past tsunami events and the corresponding boulder transport patterns with high accuracy and acceptable computational effort can be utilized as powerful forecasting models predicting the impact of a coast approaching tsunami. We have conducted small-scale physical experiments in the tilting flume with real shaped boulder models. Utilizing the structure from motion technique (Westoby et al., 2012) we reconstructed real boulders from a field study on the Island of Bonaire (Lesser Antilles, Caribbean Sea, Engel & May, 2012). The obtained three-dimensional boulder meshes are utilized for creating downscaled replica of the real boulder for physical experiments. The results of the irregular shaped boulder are compared to experiments with regular shaped boulder models to achieve a better insight about the shape related influence on transport patterns. The numerical model is based on the general two-phase mass flow model by Pudasaini (2012) enhanced for boulder transport simulations. The boulder is implemented using the immersed boundary technique (Peskin, 2002) and the direct forcing approach. In this method Cartesian grids (fluid and particle phase) and Lagrangian meshes (boulder) are combined. By applying the

  14. The perceived importance of physical activity: associations with psychosocial and health-related outcomes.

    Science.gov (United States)

    Wójcicki, Thomas R; Szabo, Amanda N; White, Siobhan M; Mailey, Emily L; Kramer, Arthur F; McAuley, Edward

    2013-03-01

    The purpose of this study was to assess the extent to which participation in a 12-month exercise program changed the degree of importance that older adults attached to physical activity. In addition, associations among changes in physical activity importance and health-related and psychosocial outcomes were examined. Community-dwelling older adults (N = 179) were recruited to participate in a 12-month exercise trial examining the association between changes in physical activity and fitness with changes in brain structure and psychological health. Participants were randomly assigned to a walking condition or a flexibility, toning, and balance condition. Physical, psychological, and cognitive assessments were taken at months 0, 6, and 12. Involvement in a 12-month exercise program increased the importance that participants placed on physical activity; this positive change was similar across exercise condition and sex. Changes in importance, however, were only associated with changes in physical health status and outcome expectations for exercise midway through the intervention. There were no significant associations at the end of the program. Regular participation in physical activity can positively influence the perceived importance of the behavior itself. Yet, the implications of such changes on physical activity-related outcomes remain equivocal and warrant further investigation.

  15. Physical multiscale modeling and numerical simulation of electrochemical devices for energy conversion and storage from theory to engineering to practice

    CERN Document Server

    Franco, Alejandro A; Bessler, Wolfgang G

    2015-01-01

    This book reviews the use of innovative physical multiscale modeling methods to deeply understand the electrochemical mechanisms and numerically simulate the structure and properties of electrochemical devices for energy storage and conversion.

  16. An integrated numerical and physical modeling system for an enhanced in situ bioremediation process

    International Nuclear Information System (INIS)

    Huang, Y.F.; Huang, G.H.; Wang, G.Q.; Lin, Q.G.; Chakma, A.

    2006-01-01

    Groundwater contamination due to releases of petroleum products is a major environmental concern in many urban districts and industrial zones. Over the past years, a few studies were undertaken to address in situ bioremediation processes coupled with contaminant transport in two- or three-dimensional domains. However, they were concentrated on natural attenuation processes for petroleum contaminants or enhanced in situ bioremediation processes in laboratory columns. In this study, an integrated numerical and physical modeling system is developed for simulating an enhanced in situ biodegradation (EISB) process coupled with three-dimensional multiphase multicomponent flow and transport simulation in a multi-dimensional pilot-scale physical model. The designed pilot-scale physical model is effective in tackling natural attenuation and EISB processes for site remediation. The simulation results demonstrate that the developed system is effective in modeling the EISB process, and can thus be used for investigating the effects of various uncertainties. - An integrated modeling system was developed to enhance in situ bioremediation processes

  17. A combined Importance Sampling and Kriging reliability method for small failure probabilities with time-demanding numerical models

    International Nuclear Information System (INIS)

    Echard, B.; Gayton, N.; Lemaire, M.; Relun, N.

    2013-01-01

    Applying reliability methods to a complex structure is often delicate for two main reasons. First, such a structure is fortunately designed with codified rules leading to a large safety margin which means that failure is a small probability event. Such a probability level is difficult to assess efficiently. Second, the structure mechanical behaviour is modelled numerically in an attempt to reproduce the real response and numerical model tends to be more and more time-demanding as its complexity is increased to improve accuracy and to consider particular mechanical behaviour. As a consequence, performing a large number of model computations cannot be considered in order to assess the failure probability. To overcome these issues, this paper proposes an original and easily implementable method called AK-IS for active learning and Kriging-based Importance Sampling. This new method is based on the AK-MCS algorithm previously published by Echard et al. [AK-MCS: an active learning reliability method combining Kriging and Monte Carlo simulation. Structural Safety 2011;33(2):145–54]. It associates the Kriging metamodel and its advantageous stochastic property with the Importance Sampling method to assess small failure probabilities. It enables the correction or validation of the FORM approximation with only a very few mechanical model computations. The efficiency of the method is, first, proved on two academic applications. It is then conducted for assessing the reliability of a challenging aerospace case study submitted to fatigue.

  18. Perceptions of Important Characteristics of Physical Activity Facilities: Implications for Engagement in Walking, Moderate and Vigorous Physical Activity

    Directory of Open Access Journals (Sweden)

    Katie M. Heinrich

    2017-11-01

    Full Text Available BackgroundAlthough few United States adults meet physical activity recommendations, those that do are more likely to access to physical activity facilities. Additionally, vigorous exercisers may be more likely to utilize a nearby physical activity facility, while light-to-moderate exercisers are less likely to do so. However, it is unclear what characteristics of those facilities are most important as well as how those characteristics are related to activity intensity.PurposeThis study examined relationships between self-reported leisure-time physical activities and the use of and perceived characteristics of physical activity facilities.MethodsData were from a cross-sectional study in a major metropolitan area. Participants (N = 582; ages 18–74, mean age = 45 ± 14.7 years were more likely to be female (69.9%, Caucasian (65.6%, married (51.7%, and have some college education (72.8%. Household surveys queried leisure-time physical activity, regular physical activity facility use, and importance ratings for key facility characteristics.ResultsLeisure-time physical activity recommendations were met by 41.0% of participants and 50.9% regularly used a physical activity facility. Regular facility use was positively associated with meeting walking (p = 0.036, moderate (p < 0.001, and vigorous (p < 0.001 recommendations. Vigorous exercisers were more likely to use a gym/fitness center (p = 0.006 and to place higher importance on facility quality (p = 0.022, variety of physical activity options offered (p = 0.003, and availability of special equipment and resources (p = 0.01. The facility characteristics of low or free cost (p = 0.02 and offering childcare (p = 0.028 were barriers for walking, and being where friends and family like to go were barriers for moderate leisure-time physical activity (p = 0.013.ConclusionFindings offer insights for structuring interventions using the social ecological

  19. From the numerics of dynamics to the dynamics of numerics and visa versa in high energy particle physics

    International Nuclear Information System (INIS)

    Zhong Ting

    2009-01-01

    Starting from the concepts of statistical symmetry we consider different aspects of the connections between nonlinear dynamics and high energy physics. We pay special attention to the interplay between number theory and dynamics. We subsequently utilize the so obtained insight to compute vital constants relevant to the program of grand unification and quantum gravity.

  20. Using physical and numerical models to study possibilities of storing natural gas in horizontal layers

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, M; Marrast, j

    1969-11-01

    The absence of suitable structures in some regions has led Gaz de France to investigate the storage of natural gas in horizontal layers. Research aimed at completing work done in this field by Soviet researchers has been carried out at the Institut Francais du Petrole using physical and numerical models together with computing. This research included an examination of storage stability, of how the effective volume of gas evolved during different cycles, of how the gas bubble migrates under the effect of a slight dip, and of the influence of instabilities. The possibility of storing gas in horizontal or sub-horizontal layers was thus justified from a theoretical viewpoint. When the time comes to make a decision concerning the creation of such a storage area, it is the economic factor that will be preponderant. The effective volume of recoverable gas has turned out to depend to a large extent on the thickness of the layer. (12 refs.)

  1. Physical and Numerical Investigations of Mould Flux Entrainment into Liquid Steel

    Directory of Open Access Journals (Sweden)

    Jowsa J.

    2016-12-01

    Full Text Available This paper presents results of model tests, performed in order to analyze phenomenon of slag droplets entrainment into steel in mould, during continuous casting process. The carried out studies took the form of laboratory experiments using physical model, in which – using similarity criteria – the behaviour of interfacial boundary liquid steel-liquid slag has been simulated using water and silicon oils, differing in physicochemical properties. Additionally, based on PIV (Particle Image Velocimetry measurements and numerical simulations, vector flow field and values of critical velocities, at which observed the occurrence of interfacial boundary silicon oil-water instability have been identified. Based on the carried out investigations, results, that illustrate relationship between critical entrainment velocity and physicochemical properties of oils have been presented.

  2. Perceived difficulty, importance, and satisfaction with physical function in COPD patients

    Directory of Open Access Journals (Sweden)

    Berry Michael J

    2004-03-01

    Full Text Available Abstract Background Research suggests that patients' satisfaction with their physical functioning (SPF is a critical component of HRQL. This study was designed to examine the extent to which perceptions of physical function and the value placed on physical function are related to satisfaction ratings. The sample consisted of older adults suffering from a progressively debilitating disease, chronic obstructive pulmonary disease (COPD. Methods During baseline assessments, COPD patients participating in a randomized controlled physical activity trial completed measures of SPF, perceived difficulty, and perceived importance. Results An ANCOVA controlling for age and gender indicated that perceived difficulty, perceived importance, and their interaction accounted for 43% of the variance in SPF. Additionally, participants were most satisfied with important tasks that they performed with little difficulty. Participants were least satisfied with important tasks that they perceived as highly difficult. Conclusion The results of the present study indicate that not being able to perform valued tasks produces discontent that is reflected in lower rating of satisfaction with physical functioning. Clearly, the significance of loss in function to individual patients is related to the importance of the functional activities that may be compromised. These data have implications for the scope of patient assessment in clinical care and for the conceptual basis of future research in the area of physical functioning.

  3. Solution of the main problem of the lunar physical libration by a numerical method

    Science.gov (United States)

    Zagidullin, Arthur; Petrova, Natalia; Nefediev, Yurii

    2016-10-01

    Series of the lunar programs requires highly accurate ephemeris of the Moon at any given time. In the light of the new requirements on the accuracy the requirements to the lunar physical libration theory increase.At the Kazan University there is the experience of constructing the lunar rotation theory in the analytical approach. Analytical theory is very informative in terms of the interpretation of the observed data, but inferior to the accuracy of numerical theories. The most accurate numerical ephemeris of the Moon is by far the ephemeris DE430 / 431 built in the USA. It takes into account a large number of subtle effects both in external perturbations of the Moon, and in its internal structure. Before the Russian scientists the task is to create its own numerical theory that would be consistent with the American ephemeris. On the other hand, even the practical application of the american ephemeris requires a deep understanding of the principles of their construction and the intelligent application.As the first step, we constructed a theory in the framework of the main problem. Because we compare our theory with the analytical theory of Petrova (1996), all the constants and the theory of orbital motion are taken identical to the analytical theory. The maximum precision, which the model can provide is 0.01 seconds of arc, which is insufficient to meet the accuracy of modern observations, but this model provides the necessary basis for further development.We have constructed the system of the libration equations, for which the numerical integrator was developed. The internal accuracy of the software integrator is several nanoseconds. When compared with the data of Petrova the differences of order of 1 second are observed at the resonant frequencies. The reason, we believe, in the inaccuracy of the analytical theory. We carried out a comparison with the Eroshkin's data [2], which gave satisfactory agreement, and with Rambaux data. In the latter case, as expected

  4. Physical mechanism and numerical simulation of the inception of the lightning upward leader

    International Nuclear Information System (INIS)

    Li Qingmin; Lu Xinchang; Shi Wei; Zhang Li; Zou Liang; Lou Jie

    2012-01-01

    The upward leader is a key physical process of the leader progression model of lightning shielding. The inception mechanism and criterion of the upward leader need further understanding and clarification. Based on leader discharge theory, this paper proposes the critical electric field intensity of the stable upward leader (CEFISUL) and characterizes it by the valve electric field intensity on the conductor surface, E L , which is the basis of a new inception criterion for the upward leader. Through numerical simulation under various physical conditions, we verified that E L is mainly related to the conductor radius, and data fitting yields the mathematical expression of E L . We further establish a computational model for lightning shielding performance of the transmission lines based on the proposed CEFISUL criterion, which reproduces the shielding failure rate of typical UHV transmission lines. The model-based calculation results agree well with the statistical data from on-site operations, which show the effectiveness and validity of the CEFISUL criterion.

  5. Numerical Study of High-Speed Droplet Impact on Surfaces and its Physical Cleaning Effects

    Science.gov (United States)

    Kondo, Tomoki; Ando, Keita

    2015-11-01

    Spurred by the demand for cleaning techniques of low environmental impact, one favors physical cleaning that does not rely on any chemicals. One of the promising candidates is based on water jets that often involve fission into droplet fragments and collide with target surfaces to which contaminant particles (often micron-sized or even smaller) stick. Hydrodynamic force (e.g., shearing and lifting) arising from the droplet impact will play a role to remove the particles, but its detailed mechanism is still unknown. To explore the role of high-speed droplet impact in physical cleaning, we solve compressible Navier-Stokes equations with a finite volume method that is designed to capture both shocks and material interfaces in accurate and robust manners. Water hammer and shear flow accompanied by high-speed droplet impact at a rigid wall is simulated to evaluate lifting force and rotating torque, which are relevant to the application of particle removal. For the simulation, we use the numerical code recently developed by Computational Flow Group lead by Tim Colonius at Caltech. The first author thanks Jomela Meng for her help in handling the code during his stay at Caltech.

  6. Precarious Rock Methodology for Seismic Hazard: Physical Testing, Numerical Modeling and Coherence Studies

    Energy Technology Data Exchange (ETDEWEB)

    Anooshehpoor, Rasool; Purvance, Matthew D.; Brune, James N.; Preston, Leiph A.; Anderson, John G.; Smith, Kenneth D.

    2006-09-29

    This report covers the following projects: Shake table tests of precarious rock methodology, field tests of precarious rocks at Yucca Mountain and comparison of the results with PSHA predictions, study of the coherence of the wave field in the ESF, and a limited survey of precarious rocks south of the proposed repository footprint. A series of shake table experiments have been carried out at the University of Nevada, Reno Large Scale Structures Laboratory. The bulk of the experiments involved scaling acceleration time histories (uniaxial forcing) from 0.1g to the point where the objects on the shake table overturned a specified number of times. The results of these experiments have been compared with numerical overturning predictions. Numerical predictions for toppling of large objects with simple contact conditions (e.g., I-beams with sharp basal edges) agree well with shake-table results. The numerical model slightly underpredicts the overturning of small rectangular blocks. It overpredicts the overturning PGA for asymmetric granite boulders with complex basal contact conditions. In general the results confirm the approximate predictions of previous studies. Field testing of several rocks at Yucca Mountain has approximately confirmed the preliminary results from previous studies, suggesting that he PSHA predictions are too high, possibly because the uncertainty in the mean of the attenuation relations. Study of the coherence of wavefields in the ESF has provided results which will be very important in design of the canisters distribution, in particular a preliminary estimate of the wavelengths at which the wavefields become incoherent. No evidence was found for extreme focusing by lens-like inhomogeneities. A limited survey for precarious rocks confirmed that they extend south of the repository, and one of these has been field tested.

  7. Synthesis of the scientific French speaking days on numerical codes in radiation protection, in radio physics and in dosimetry

    International Nuclear Information System (INIS)

    Paul, D.; Makovicka, L.; Ricard, M.

    2005-01-01

    Synthesis of the scientific French speaking days on numerical codes in radiation protection, in radio-physics and in dosimetry. The paper carries the title of 'French speaking' scientific days co-organized on October 2-3, 2003 in Sochaux by the SFRP, SFPM and FIRAM societies. It has for objective to establish the scientific balance sheet of this international event, to give the synthesis of current tendencies in the field of the development and of the use of the numerical codes in radiation protection, in radio-physics and in dosimetry. (author)

  8. Numerical and Physical Parametric Analysis of a SEN with Flow Conditioners in Slab Continuous Casting Mold

    Directory of Open Access Journals (Sweden)

    Gonzalez-Trejo J.

    2017-06-01

    Full Text Available Some of the most recent technologies that improves the performance in continuous casting process has installed infrastructure outside the mold to modify the natural fluid flow pattern to obtain a quasi-steady condition and promote a uniform solidified shell of steel. The submerged entry nozzle distributes the liquid steel in the mold and can be used to obtain the flow symmetry condition with external geometry improvements. The fluid flow conditioners were located near the outlet ports of the nozzle. The aim of the modifiers is to impose a pseudo symmetric pattern in the upper zone of the mold by inhibiting the fluid exchange between the zones created by conditioners. This work evaluates the effect of the thickness and length of the fluid-flow modifiers on the overall performance of the submerged nozzle. These properties of the fluid-flow modifiers were normalized based on two of the geometric dimensions of the standard equipment. Numerical and physical simulations suggest that the flow modifier should be as thin as possible.

  9. Numerical Investigation on Sensitivity of Liquid Jet Breakup to Physical Fuel Properties with Experimental Comparison

    Science.gov (United States)

    Kim, Dokyun; Bravo, Luis; Matusik, Katarzyna; Duke, Daniel; Kastengren, Alan; Swantek, Andy; Powell, Christopher; Ham, Frank

    2016-11-01

    One of the major concerns in modern direct injection engines is the sensitivity of engine performance to fuel characteristics. Recent works have shown that even slight differences in fuel properties can cause significant changes in efficiency and emission of an engine. Since the combustion process is very sensitive to the fuel/air mixture formation resulting from disintegration of liquid jet, the precise assessment of fuel sensitivity on liquid jet atomization process is required first to study the impact of different fuels on the combustion. In the present study, the breaking process of a liquid jet from a diesel injector injecting into a quiescent gas chamber is investigated numerically and experimentally for different liquid fuels (n-dodecane, iso-octane, CAT A2 and C3). The unsplit geometric Volume-of-Fluid method is employed to capture the phase interface in Large-eddy simulations and results are compared against the radiography measurement from Argonne National Lab including jet penetration, liquid mass distribution and volume fraction. The breakup characteristics will be shown for different fuels as well as droplet PDF statistics to demonstrate the influences of the physical properties on the primary atomization of liquid jet. Supported by HPCMP FRONTIER award, US DOD, Office of the Army.

  10. Methods tuned on the physical problem. A way to improve numerical codes

    International Nuclear Information System (INIS)

    Ixaru, L.Gr.

    2010-01-01

    We consider the problem on how the numerical methods tuned on the physical problem can contribute to the enhancement of the performance of the codes. We illustrate this on two simple cases: solution of time independent one-dimensional Schroedinger equation, and the computation of integrals with oscillatory integrands. In both cases the tuned versions bring a massive gain in accuracy at negligible extra cost. We presented two simple problems where successive levels of tuning enhance significantly the accuracy at negligible extra cost. These problems should be seen as representing only some illustrations on how the codes can be improved but we must also mention that in many cases tuned versions still have to be developed. Just for a suggestion, quadrature formulae which involve the integrand and a number of successive derivatives of this exist, but no formula is available when some of these derivatives are missing, for example when we dispose of y and y'' but not of y'. A direct application will be on the case when the integrand involves the solution of the Schrodinger equation by the method of Numerov. (author)

  11. Importance of facial physical attractiveness of audiovisual models in descriptions and preferences of children and adolescents.

    Science.gov (United States)

    Ruiz, Cristina; Conde, Elena; Torres, Esteban

    2005-08-01

    We performed a cross-sectional study with three age groups (8, 14, and 17 years) to evaluate developmental differences in stereotyped beliefs about physical attractiveness and the value of this as perceived by the participants. Given the current importance of television in the development of social knowledge, television models were used. The children and adolescents were asked to evaluate, using bipolar open scales, the physical attractiveness, likeableness, generosity, intelligence, fun, and altruism of 12 television models of both sexes, previously selected by judges, as well as the desire to resemble or feel close to the models. Analysis showed developmental differences across age groups both in the concept of physical attractiveness and in stereotyped beliefs about this. As in other areas of social knowledge, the younger children's responses were bipolar, global, and much more stereotyped, while the adolescents introduced subtle distinctions and elaborated their responses. Nevertheless, physical attractiveness appeared a desirable characteristic for all age groups.

  12. [Importance of history and physical examination for the care of nurses].

    Science.gov (United States)

    Santos, Neuma; Veiga, Patrícia; Andrade, Renata

    2011-01-01

    The history and physical examination are part of data collection of the Nursing Process. Its implementation is aimed at individualized care, holistic, humane and scientific foundation. The literature review was carried out in indexed databases as LILACS and SciELO, books and journals available in local libraries as published between the years 2000 to 2009. The aim is to describe the importance of clinical history and physical examination in the care provided by nurses. The results of this research will enable nursing students and health professionals can better understand the importance of history taking and physical examination to their professional practice, implement properly all stages of NAS and arouse interest in research on this topic.

  13. Analysis of motivational profiles of satisfaction and importance of physical education in high school adolescents.

    Science.gov (United States)

    Granero-Gallegos, Antonio; Baena-Extremera, Antonio; Pérez-Quero, Francisco J; Ortiz-Camacho, Maria M; Bracho-Amador, Clara

    2012-01-01

    The purpose of this study was to analyze the motivational profiles of satisfaction with and importance of physical education in high school students and its relation with gender and the practice of sport. The sample comprised 2002 students aged from 12 to 19 who completed the Sport Motivation Scale (Núñez et al., 2006), the Sport Satisfaction Instrument (Baena-Extremera et al., 2012) and the Importance of Physical Education Scale (Moreno et al., 2009). Descriptive analyzes, correlations between the scales, a cluster analysis for profiles, and a MANOVA were conducted to examine differences by gender. Three clusters (profiles) were identified. The first profile identified was "moderate" motivation (n = 463) and was associated with boys who practice physical activity for less than 3 hours per week. The second profile identified was "low" motivation (n = 545) and was associated mainly with girls who practice physical activity for less than 3 hours per week. And lastly the third profile identified was "high" motivation (n = 910), which was found to be greater in boys who practiced physical exercise for more than 3 hours a week.

  14. ANALYSIS OF MOTIVATIONAL PROFILES OF SATISFACTION AND IMPORTANCE OF PHYSICAL EDUCATION IN HIGH SCHOOL ADOLESCENTS

    Directory of Open Access Journals (Sweden)

    Antonio Granero-Gallegos

    2012-12-01

    Full Text Available he purpose of this study was to analyze the motivational profiles of satisfaction with and importance of physical education in high school students and its relation with gender and the practice of sport. The sample comprised 2002 students aged from 12 to 19 who completed the Sport Motivation Scale (Núñez et al., 2006, the Perception of Success Scale (Martínez et al., 2006, the Sport Satisfaction Instrument (Baena-Extremera et al., 2012 and the Importance of Physical Education Scale (Moreno et al., 2009. Descriptive analyzes, correlations between the scales, a cluster analysis for profiles, and a MANOVA were conducted to examine differences by gender. Three clusters (profiles were identified. The first profile identified was "moderate" motivation (n = 463 and was associated with boys who practice physical activity for less than 3 hours per week. The second profile identified was "low" motivation (n = 545 and was associated mainly with girls who practice physical activity for less than 3 hours per week. And lastly the third profile identified was "high" motivation (n = 910, which was found to be greater in boys who practiced physical exercise for more than 3 hours a week

  15. III. The importance of physical activity and aerobic fitness for cognitive control and memory in children.

    Science.gov (United States)

    Chaddock-Heyman, Laura; Hillman, Charles H; Cohen, Neal J; Kramer, Arthur F

    2014-12-01

    In this chapter, we review literature that examines the association among physical activity, aerobic fitness, cognition, and the brain in elementary school children (ages 7-10 years). Specifically, physical activity and higher levels of aerobic fitness in children have been found to benefit brain structure, brain function, cognition, and school achievement. For example, higher fit children have larger brain volumes in the basal ganglia and hippocampus, which relate to superior performance on tasks of cognitive control and memory, respectively, when compared to their lower fit peers. Higher fit children also show superior brain function during tasks of cognitive control, better scores on tests of academic achievement, and higher performance on a real-world street crossing task, compared to lower fit and less active children. The cross-sectional findings are strengthened by a few randomized, controlled trials, which demonstrate that children randomly assigned to a physical activity intervention group show greater brain and cognitive benefits compared to a control group. Because these findings suggest that the developing brain is plastic and sensitive to lifestyle factors, we also discuss typical structural and functional brain maturation in children to provide context in which to interpret the effects of physical activity and aerobic fitness on the developing brain. This research is important because children are becoming increasingly sedentary, physically inactive, and unfit. An important goal of this review is to emphasize the importance of physical activity and aerobic fitness for the cognitive and brain health of today's youth. © 2014 The Society for Research in Child Development, Inc.

  16. [Social support and physical activity in adolescents from public schools: the importance of family and friends].

    Science.gov (United States)

    Prado, Crisley Vanessa; Lima, Alex Vieira; Fermino, Rogério César; Añez, Ciro Romelio Rodriguez; Reis, Rodrigo Siqueira

    2014-04-01

    The aim of this study was to verify the association between different types and sources of social support and physical activity among adolescents from Curitiba, Paraná State, Brazil. A school-based survey was conducted with a representative sample of adolescents from public schools (n = 1,469). Multiple regression models were used to test the association between weekly frequency and sources of social support from family and friends and weekly frequency of physical activity. Among boys, frequent company of family (PR: 2.88; 95%CI: 2.00-4.13) and friends (PR: 5.46; 95%CI: 2.33-12.78) and positive reinforcement from friends (PR: 1.81; 95%CI: 1.18-2.77) were positively associated with physical activity. Sporadic invitation by the family was negatively associated with physical activity (PR: 0.66; 95%CI: 0.46-1.14). For girls, frequent company of family (PR: 3.39; 95%CI: 1.49-7.69) and friends (PR: 4.06; 95%CI: 2.22-7.45) increased the likelihood of physical activity. Company of friends was the most important type of social support for physical activity among these adolescents.

  17. Difficulty in the Clinical Diagnosis of Tularemia: Highlighting the Importance of a Physical Exam

    Directory of Open Access Journals (Sweden)

    Rupin Kumar

    2018-01-01

    Full Text Available We report an 18-month-old male who presented with fever and nonspecific symptoms. He was evaluated for multiple differential diagnoses including Kawasaki disease and JIA and received treatment for them. After he was readmitted, tularemia was considered based on the physical exam finding of an ulcer on the scalp and enlarged lymph nodes. Tularemia titers were positive, and the patient was given the appropriate antibiotic and was discharged home. Follow-up of the patient showed complete resolution of symptoms. This is a case that demonstrates the importance of physical exam in identifying rare diseases presenting with common signs and symptoms.

  18. RELAP-7 Software Verification and Validation Plan: Requirements Traceability Matrix (RTM) Part 1 – Physics and numerical methods

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Joon [Idaho National Lab. (INL), Idaho Falls, ID (United States); Yoo, Jun Soo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    This INL plan comprehensively describes the Requirements Traceability Matrix (RTM) on main physics and numerical method of the RELAP-7. The plan also describes the testing-based software verification and validation (SV&V) process—a set of specially designed software models used to test RELAP-7.

  19. The Numerical Tokamak Project (NTP) simulation of turbulent transport in the core plasma: A grand challenge in plasma physics

    International Nuclear Information System (INIS)

    1993-12-01

    The long-range goal of the Numerical Tokamak Project (NTP) is the reliable prediction of tokamak performance using physics-based numerical tools describing tokamak physics. The NTP is accomplishing the development of the most advanced particle and extended fluid model's on massively parallel processing (MPP) environments as part of a multi-institutional, multi-disciplinary numerical study of tokamak core fluctuations. The NTP is a continuing focus of the Office of Fusion Energy's theory and computation program. Near-term HPCC work concentrates on developing a predictive numerical description of the core plasma transport in tokamaks driven by low-frequency collective fluctuations. This work addresses one of the greatest intellectual challenges to our understanding of the physics of tokamak performance and needs the most advanced computational resources to progress. We are conducting detailed comparisons of kinetic and fluid numerical models of tokamak turbulence. These comparisons are stimulating the improvement of each and the development of hybrid models which embody aspects of both. The combination of emerging massively parallel processing hardware and algorithmic improvements will result in an estimated 10**2--10**6 performance increase. Development of information processing and visualization tools is accelerating our comparison of computational models to one another, to experimental data, and to analytical theory, providing a bootstrap effect in our understanding of the target physics. The measure of success is the degree to which the experimentally observed scaling of fluctuation-driven transport may be predicted numerically. The NTP is advancing the HPCC Initiative through its state-of-the-art computational work. We are pushing the capability of high performance computing through our efforts which are strongly leveraged by OFE support

  20. Prediction of changes in important physical parameters during composting of separated animal slurry solid fractions

    DEFF Research Database (Denmark)

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-01-01

    Solid-liquid separation of animal slurry, with solid fractions used for composting, has gained interest recently. However, efficient composting of separated animal slurry solid fractions (SSFs) requires a better understanding of the process dynamics in terms of important physical parameters...... and their interacting physical relationships in the composting matrix. Here we monitored moisture content, bulk density, particle density and air-filled porosity (AFP) during composting of SSF collected from four commercially available solid-liquid separators. Composting was performed in laboratory-scale reactors...... for 30 days (d) under forced aeration and measurements were conducted on the solid samples at the beginning of composting and at 10-d intervals during composting. The results suggest that differences in initial physical properties of SSF influence the development of compost maximum temperatures (40...

  1. Analysis of the Source Physics Experiment SPE4 Prime Using State-Of Parallel Numerical Tools.

    Science.gov (United States)

    Vorobiev, O.; Ezzedine, S. M.; Antoun, T.; Glenn, L.

    2015-12-01

    This work describes a methodology used for large scale modeling of wave propagation from underground chemical explosions conducted at the Nevada National Security Site (NNSS) fractured granitic rock. We show that the discrete natures of rock masses as well as the spatial variability of the fabric of rock properties are very important to understand ground motions induced by underground explosions. In order to build a credible conceptual model of the subsurface we integrated the geological, geomechanical and geophysical characterizations conducted during recent test at the NNSS as well as historical data from the characterization during the underground nuclear test conducted at the NNSS. Because detailed site characterization is limited, expensive and, in some instances, impossible we have numerically investigated the effects of the characterization gaps on the overall response of the system. We performed several computational studies to identify the key important geologic features specific to fractured media mainly the joints characterized at the NNSS. We have also explored common key features to both geological environments such as saturation and topography and assess which characteristics affect the most the ground motion in the near-field and in the far-field. Stochastic representation of these features based on the field characterizations has been implemented into LLNL's Geodyn-L hydrocode. Simulations were used to guide site characterization efforts in order to provide the essential data to the modeling community. We validate our computational results by comparing the measured and computed ground motion at various ranges for the recently executed SPE4 prime experiment. We have also conducted a comparative study between SPE4 prime and previous experiments SPE1 and SPE3 to assess similarities and differences and draw conclusions on designing SPE5.

  2. W.E. Henry Symposium compendium: The importance of magnetism in physics and material science

    Energy Technology Data Exchange (ETDEWEB)

    Carwell, H.

    1997-09-19

    This compendium contains papers presented at the W. E. Henry Symposium, The Importance of Magnetism in Physics and Material Science. The one-day symposium was conducted to recognize the achievements of Dr. Warren Elliot Henry as educator, scientist, and inventor in a career spanning almost 70 years. Dr. Henry, who is 88 years old, attended the symposium. Nobel Laureate, Dr. Glenn Seaborg, a friend and colleague for over 40 years, attended the event and shared his personal reminiscences. Dr. Seaborg is Associate Director-At-Large at the Lawrence Berkeley National Laboratory. The Compendium begins with three papers which demonstrate the ongoing importance of magnetism in physics and material science. Other contributions cover the highlights of Dr. Henry`s career as a researcher, educator, and inventor. Colleagues and former students share insights on the impact of Dr. Henry`s research in the field of magnetism, low temperature physics, and solid state physics; his influence on students as an educator; and his character, intellect and ingenuity, and passion for learning and teaching. They share a glimpse of the environment and times that molded him as a man, and the circumstances under which he made his great achievements despite the many challenges he faced.

  3. Cross-flow turbines: physical and numerical model studies towards improved array simulations

    Science.gov (United States)

    Wosnik, M.; Bachant, P.

    2015-12-01

    Cross-flow, or vertical-axis turbines, show potential in marine hydrokinetic (MHK) and wind energy applications. As turbine designs mature, the research focus is shifting from individual devices towards improving turbine array layouts for maximizing overall power output, i.e., minimizing wake interference for axial-flow turbines, or taking advantage of constructive wake interaction for cross-flow turbines. Numerical simulations are generally better suited to explore the turbine array design parameter space, as physical model studies of large arrays at large model scale would be expensive. However, since the computing power available today is not sufficient to conduct simulations of the flow in and around large arrays of turbines with fully resolved turbine geometries, the turbines' interaction with the energy resource needs to be parameterized, or modeled. Most models in use today, e.g. actuator disk, are not able to predict the unique wake structure generated by cross-flow turbines. Experiments were carried out using a high-resolution turbine test bed in a large cross-section tow tank, designed to achieve sufficiently high Reynolds numbers for the results to be Reynolds number independent with respect to turbine performance and wake statistics, such that they can be reliably extrapolated to full scale and used for model validation. To improve parameterization in array simulations, an actuator line model (ALM) was developed to provide a computationally feasible method for simulating full turbine arrays inside Navier--Stokes models. The ALM predicts turbine loading with the blade element method combined with sub-models for dynamic stall and flow curvature. The open-source software is written as an extension library for the OpenFOAM CFD package, which allows the ALM body force to be applied to their standard RANS and LES solvers. Turbine forcing is also applied to volume of fluid (VOF) models, e.g., for predicting free surface effects on submerged MHK devices. An

  4. On the physical and chemical details of alumina atomic layer deposition: A combined experimental and numerical approach

    International Nuclear Information System (INIS)

    Pan, Dongqing; Ma, Lulu; Xie, Yuanyuan; Yuan, Chris; Jen, Tien Chien

    2015-01-01

    Alumina thin film is typically studied as a model atomic layer deposition (ALD) process due to its high dielectric constant, high thermal stability, and good adhesion on various wafer surfaces. Despite extensive applications of alumina ALD in microelectronics industries, details on the physical and chemical processes are not yet well understood. ALD experiments are not able to shed adequate light on the detailed information regarding the transient ALD process. Most of current numerical approaches lack detailed surface reaction mechanisms, and their results are not well correlated with experimental observations. In this paper, the authors present a combined experimental and numerical study on the details of flow and surface reactions in alumina ALD using trimethylaluminum and water as precursors. Results obtained from experiments and simulations are compared and correlated. By experiments, growth rate on five samples under different deposition conditions is characterized. The deposition rate from numerical simulation agrees well with the experimental results. Details of precursor distributions in a full cycle of ALD are studied numerically to bridge between experimental observations and simulations. The 3D transient numerical model adopts surface reaction kinetics and mechanisms based on atomic-level studies to investigate the surface deposition process. Surface deposition is shown as a strictly self-limited process in our numerical studies. ALD is a complex strong-coupled fluid, thermal and chemical process, which is not only heavily dependent on the chemical kinetics and surface conditions but also on the flow and material distributions

  5. Importance of the professional competencies of the Primary Teachers in Physical Education expressed by the students

    Directory of Open Access Journals (Sweden)

    Cipriano Romero Cerezo

    2011-01-01

    Full Text Available With this work we have tried to determine which have been the professional competencies Physical Education students valued more for their future professional development. This is a descriptive and transverse study with a population of 439 Physical Education students from three Andalusian universities, Granada, Jaen and Almería. We have used a questionnaire designed to the effect, Questionnaire of Professional Competencies for Physical Education Primary Teacher. The purpose was to obtain information about the importance the students grant to the different types of competencies: transversal, basic and specific. We have used a four-option Likert-scale. The descriptive analysis has allowed us to arrange the most valued competencies and the inferential analysis has made it possible to establish the differences depending on the genre and the course of the students (t student and ANOVA of a factor respectively. The factor most value is the ability to work in groups, to stimulate others, transmit values and set up necessary links between aspects such as physical education and hygiene, body postures and health

  6. Task A, High energy physics program experiment and theory: Task B, High energy physics program numerical simulation

    International Nuclear Information System (INIS)

    1990-01-01

    This report discusses progress in experimental and theoretical High Energy Physics at Florida State University. Fixed target experiments, collider experiments, computing, networking, VAX upgrade, SSC preparation, detector development, and particle theory are some of the areas covered

  7. Importance of Self-Efficacy and Knowledge to Physical Activity Behavior in Older African Americans.

    Science.gov (United States)

    Babatunde, Oyinlola Toyin

    2015-11-01

    Regular physical activity is an important lifestyle behavior for preventing or reducing the burden of osteoporosis, and for promoting optimal bone health. This report evaluates the effect of an osteoporosis education program on knowledge, self-efficacy, and initiation and/maintenance of physical activity (PA) in older African Americans. African American adults 50 years and older (n=130) were randomly assigned to either experimental (EG) or control (CG) groups. Immediately following baseline assessment EG was offered six-weekly education sessions, using the Expanded Heath Belief Model and the CG offered same after the intervention. Main outcome measures were knowledge and self-efficacy regarding osteoporosis and engagement in PA. One hundred and ten (59=EG, 51=CG) participants completed all assessments. Overall, significantly higher (p<.01) mean self-efficacy and knowledge scores were observed in the EG than in the CG. Physical activity scores were positively related to self-efficacy but not knowledge scores. Self-efficacy is important in increasing PA in older African Americans, and emphasis on culturally appropriate strategies may improve PA and reduce the risk of osteoporotic fracture.

  8. Physical activities and their importance to the health of people with severe mental illness in Sweden.

    Science.gov (United States)

    Erdner, Anette; Magnusson, Annabella

    2012-10-01

    It is well known that people with severe mental illness often suffer from constant fatigue, insomnia, and somatic complaints that are too often overlooked. In addition, these persons die earlier in life than others in the population. The purpose of this study was to investigate patients' descriptions of activities and the importance of these activities for their health. Eight persons living in their own home were interviewed about both their views about exercise and their exercising activities. Two themes emerged: Getting Control over One's Life and The Need for Contact with Family & Friends. All of the informants were aware of the importance of physical activity to feel good. The informants described three different forms of activities: daily activities in the home, activities in a rehabilitation centre, and various forms of jogging. These different forms of activity were important to the informants since they reduced their anxiety and stress.

  9. Location and deprivation are important influencers of physical activity in primary care populations.

    Science.gov (United States)

    Barrett, E M; Hussey, J; Darker, C D

    2016-07-01

    To investigate the physical activity of adults attending primary care services in the Republic of Ireland and to determine whether the location (urban/rural) and deprivation of the primary care centre influenced physical activity. Cross sectional study. Stratified random sampling based on urban/rural location and deprivation was used to identify three primary care centres from a list of established primary care teams in the Leinster region. The International Physical Activity Questionnaire (IPAQ) was used to collate data on physical activity category (low/moderate/high), total weekly activity (MET-minutes/week) and weekly walking (MET-minutes/week) of participants. Data from 885 participants with a median age of 39 years (IQR 31-53) were analysed. There were significant differences in physical activity between the primary care areas (P < 0.001). Rural mixed deprivation participants were the least active with almost 60% of this group (59.4%, n = 177) classified as inactive (535 median MET-minutes/week, IQR 132-1197). Urban deprived participants were the most active (low active 37.6%, n = 111, 975 median MET-minutes/week, IQR 445-1933). Upon adjustment for multiple factors, rural participants (OR = 2.81, 95% CI 1.97-4.01), urban non-deprived participants (OR = 1.61, 95% CI 1.08-2.39), females (OR = 1.66, 95% CI 1.23-2.23) and older adults (OR = 1.01, 95% CI 1.00-1.02) were more likely to be categorised as low active. Overall 47.2% (n = 418) of all participants were classified within the low physical activity category. Significant disparities exist in the physical activity levels of primary care populations. This has important implications for the funding and planning of physical activity interventions. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  10. Physical activity and bone: The importance of the various mechanical stimuli for bone mineral density. A review

    Directory of Open Access Journals (Sweden)

    Bente Morseth

    2011-08-01

    Full Text Available Numerous studies have reported benefits of regular physical activity on bone mineral density (BMD. The effects of physical activity on BMD are primarily linked to the mechanisms of mechanical loading, but the understanding of the precise mechanism behind the association is incomplete. The aim of this paper was to review the main findings concerning sources and types of mechanical stimuli in relation to BMD. Mechanical forces that act on bone are generated from impact with the ground (ground-reaction forces and from skeletal muscle contractions (muscle forces or muscle-joint forces, but the relative importance of these two sources has not been elucidated. Both muscle-joint forces and gravitational forces seem to be able to induce bone adaptation independently, and there may be differences in the importance of loading sources at different skeletal sites. The nature of the stimuli is affected by the type, intensity, frequency, and duration of the activity. The activity should be dynamic, not static, and the magnitude and rate of the stimuli should be high. In accordance with this, cross-sectional studies report highest BMD in athletes of high-impact activities such as dancing, soccer, volleyball, basketball, squash, speed skating, gymnastics, hockey, and step-aerobics. Endurance activities such as orienteering, skiing, and triathlon seem to be beneficial to a lesser degree, whereas low-impact activities such as swimming and cycling are associated with lower BMD than controls. Both the intensity and frequency of the activity should be varied and increased beyond the habitual level. Duration of the activity seems to be less important, and a few loading cycles seem to be sufficient.

  11. Physical protection of export/import and transportation of nuclear material in the Slovak Republic

    International Nuclear Information System (INIS)

    Vaclav, J

    2002-01-01

    Full text: The paper contains short overview about average amount of nuclear materials transported on the territory of the Slovak Republic in a year, and the physical protection of these nuclear materials. There are several types of transportation and export/import of nuclear materials in the SR: fresh fuel import; import of other unirradiated nuclear materials (e.g. depleted uranium, natural uranium); export of unirradiated nuclear materials (e.g. natural uranium); internal transportation of fresh fuel; internal transportation of other unirradiated nuclear materials; internal transportation of spent fuel. The main objective of the nuclear regulatory authority SR is to supervise observation of the national legislation as follows: the act no. 130 / 1998 on peaceful use of nuclear energy; UJD SR's regulation no. 186/1999 which details the physical protection of the nuclear facilities, nuclear materials, and radioactive waste (following requirements of INFCIRC 225 / Rev. 4); UJD SR's regulation no. 284 / 1999 which details conditions of nuclear material and radioactive wastes transportation. (author)

  12. Analytical and numerical study of validation test-cases for multi-physic problems: application to magneto-hydro-dynamic

    Directory of Open Access Journals (Sweden)

    D Cébron

    2016-04-01

    Full Text Available The present paper is concerned with the numerical simulation of Magneto-Hydro-Dynamic (MHD problems with industrial tools. MHD has receivedattention some twenty to thirty years ago as a possible alternative inpropulsion applications; MHD propelled ships have even been designed forthat purpose. However, such propulsion systems have been proved of lowefficiency and fundamental researches in the area have progressivelyreceived much less attention over the past decades. Numerical simulationof MHD problem could however provide interesting solutions in the field ofturbulent flow control. The development of recent efficient numericaltechniques for multi-physic applications provide promising tool for theengineer for that purpose. In the present paper, some elementary testcases in laminar flow with magnetic forcing terms are analysed; equationsof the coupled problem are exposed, analytical solutions are derived ineach case and are compared to numerical solutions obtained with anumerical tool for multi-physic applications. The present work can be seenas a validation of numerical tools (based on the finite element method foracademic as well as industrial application purposes.

  13. THE IMPORTANCE OF THE TRADITIONAL SANDZAK GAMES FOR PHYSICAL EDUCATION IN SCHOOLS

    Directory of Open Access Journals (Sweden)

    Mersud Koca

    2008-08-01

    Full Text Available Many games have been preserved as a custom, particularly among children, much after the young used to play them. In most of the cases, traditional games represent imitation of the adults’ society. Those games are numerous, with an easy start and ending, so the children use them in any possible situation. The implementation of these games and some traditional toys in the nurseries and primary schools in Novi Pazar, has proved our assumptions that teachers has given them positive marks, and even more important is that children are eager to use them and show some interests for their existence. A school can apply various sources within educational process and other out school activities.

  14. IMPORTANCE OF PHYSICAL QUALITIES FOR SPEED AND CHANGE OF DIRECTION ABILITY IN ELITE FEMALE SOCCER PLAYERS.

    OpenAIRE

    Emmonds, S; Nicholson, G; Beggs, CB; Jones, B; Bissas, A

    2017-01-01

    The purpose of this study was to determine the importance of physical qualities for speed and change of direction (CoD) ability in female soccer players. Data were collected on 10 female soccer players who were part of a professional English Women’s Super League team. Player assessments included anthropometric (stature and body mass), body composition (dual-energy X-ray absorptiometry), speed (10m, 30m sprint), CoD ability (505 agility), aerobic (Yo-Yo Intermittent Recovery Test), lower-body ...

  15. Dynamical properties of fractal networks: Scaling, numerical simulations, and physical realizations

    International Nuclear Information System (INIS)

    Nakayama, T.; Yakubo, K.; Orbach, R.L.

    1994-01-01

    This article describes the advances that have been made over the past ten years on the problem of fracton excitations in fractal structures. The relevant systems to this subject are so numerous that focus is limited to a specific structure, the percolating network. Recent progress has followed three directions: scaling, numerical simulations, and experiment. In a happy coincidence, large-scale computations, especially those involving array processors, have become possible in recent years. Experimental techniques such as light- and neutron-scattering experiments have also been developed. Together, they form the basis for a review article useful as a guide to understanding these developments and for charting future research directions. In addition, new numerical simulation results for the dynamical properties of diluted antiferromagnets are presented and interpreted in terms of scaling arguments. The authors hope this article will bring the major advances and future issues facing this field into clearer focus, and will stimulate further research on the dynamical properties of random systems

  16. Mathematical and numerical study of non-linear models used in plasma physics

    International Nuclear Information System (INIS)

    Ebrard, G.

    2005-12-01

    We study the interaction of several crossing beams with a plasma in the Laser-Megajoule context. We start from Euler-Maxwell. The formal asymptotic is the Zakharov system. For simplified systems of Klein-Gordon-wave type, we justify an approximation by a Zakharov equation for solutions of large amplitude. We construct a new system that simulates the interaction of 2 beams and present a whole hierarchy of models. We introduce a numerical scheme using the known results on Zakharov-wave equations which are valid for short pulses. We give a scheme which eliminate the backscattering wave. We give some numerical results. Finally, we do several numerical simulations of laser-plasma interaction for the initial value problem and the boundary value problem. (author)

  17. Free Radical Addition Polymerization Kinetics without Steady-State Approximations: A Numerical Analysis for the Polymer, Physical, or Advanced Organic Chemistry Course

    Science.gov (United States)

    Iler, H. Darrell; Brown, Amber; Landis, Amanda; Schimke, Greg; Peters, George

    2014-01-01

    A numerical analysis of the free radical addition polymerization system is described that provides those teaching polymer, physical, or advanced organic chemistry courses the opportunity to introduce students to numerical methods in the context of a simple but mathematically stiff chemical kinetic system. Numerical analysis can lead students to an…

  18. Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

    DEFF Research Database (Denmark)

    Krogsbøll, Anette Susanne; Fuglsang, Leif D

    2006-01-01

    The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anchor...

  19. Linking Physical and Numerical Modelling in Hydrogeology Using Sand Tank Experiments and Comsol Multiphysics

    Science.gov (United States)

    Singha, Kamini; Loheide, Steven P., II

    2011-01-01

    Visualising subsurface processes in hydrogeology and building intuition for how these processes are controlled by changes in forcing is hard for many undergraduate students. While numerical modelling is one way to help undergraduate students explore outcomes of multiple scenarios, many codes are not user-friendly with respect to defining domains,…

  20. The relative importance of physical and biological energy in landscape evolution

    Science.gov (United States)

    Turowski, J. M.; Schwanghart, W.

    2017-12-01

    Landscapes are formed by the interplay of uplift and geomorphic processes, including interacting and competing physical and biological processes. For example, roots re-inforce soil and thereby stabilize hillslopes and the canopy cover of the forest may mediate the impact of precipitation. Furthermore, plants and animals act as geomorphic agents, directly altering landscape response and dynamics by their actions: tree roots may crack rocks, thus changing subsurface water flows and exposing fresh material for denudation; fungi excrete acids that accelerate rates of chemical weathering, and burrowing animals displace soil and rocks while digging holes for shelter or in search of food. Energetically, landscapes can be viewed as open systems in which topography stores potential energy above a base level. Tectonic processes add energy to the system by uplift and mechanically altering rock properties. Especially in unvegetated regions, erosion and transport by wind can be an important geomorphic process. Advection of atmospheric moisture in high altitudes provides potential energy that is converted by water fluxes through catchments. At the same time, the conversion of solar energy through atmospheric and biological processes drives primary production of living organisms. If we accept that biota influence geomorphic processes, then what is their energetic contribution to landscape evolution relative to physical processes? Using two case studies, we demonstrate that all components of energy input are negligible apart from biological production, quantified by net primary productivity (NPP) and potential energy conversion by water that is placed high up in the landscape as rainfall and leaves it as runoff. Assuming that the former is representative for biological energy and the latter for physical energy, we propose that the ratio of these two values can be used as a proxy for the relative importance of biological and physical processes in landscape evolution. All necessary

  1. How important is young children's actual and perceived movement skill competence to their physical activity?

    Science.gov (United States)

    Slykerman, Sarah; Ridgers, Nicola D; Stevenson, Christopher; Barnett, Lisa M

    2016-06-01

    To determine the associations between young children's actual and perceived object control and locomotor skills and physical activity and whether associations differ by sex. Cross sectional study. A total of 136 children consented. Children had actual skill (Test of Gross Motor Development-2), perceived skill (Pictorial Scale of Perceived Movement Skill Competence for Young Children), and moderate- to vigorous-intensity physical activity (MVPA) (accelerometers) assessed. Independent t-tests assessed sex differences. A regression (with MVPA as the outcome) was performed with all predictor variables (i.e. Actual Object Control, Actual Locomotor, Perceived Object Control, and Perceived Locomotor). Model 2 also adjusted for age, sex, accelerometer wear time and whether the child was from an English speaking background. Interaction terms between the respective actual or perceived skill factor and sex were added to assess sex differences. Analyses were conducted on 109 children (59 boys, 50 girls; mean age=6.5 years, SD=1.0). Boys had higher actual and perceived object control skill and were more active by an average of 19min per day. There were no sex differences in locomotor skills. There were no associations between skill factors and MVPA, except for girls, where locomotor skill was a significant predictor of MVPA (B=3.66, p=0.016). Actual rather than perceived skill competence was more important to MVPA in this sample. Locomotor skill competence may be more important than object control skill competence for girls as they may engage in types of physical activity that do not require object control mastery. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  2. The importance of physical activity and diet in the life of female students

    Directory of Open Access Journals (Sweden)

    Rafał Pawłowski

    2015-10-01

    Full Text Available Introduction : The lifestyle is known to be the most influential factor for maintaining a good health condition. Lack of physical activity and poor nutrition are two factors that suport each other in a negative way and result in an increasing number of obese people. Irregular nutrition is often closely related to irregular academic life. Aim of the research: The objective of this research is to find out how female students perceive health – how they understand and define it. Another objective is to determine whether nurses-to-be and psychiatrists-to-be perceive health differently than other students and whether their health-esteem is backed with their free-time physical activity and regular nutrition. It is crucial to find out what factors, according to the research, have the biggest influence on people’s health. Material and methods: The research involved 180 female students of full-time courses at the Jan Kochanowski University in Kielce: 98 female students of the Health Sciences Faculty and 82 female students of other faculties. The method of a diagnostic survey and a questionnaire were used in the research. Results : The female students perceived health as a quality, well-being, an absence of disease; and for female nursing students health was not only the absence of disease or disability but also biopsychosocial well-being. The most important factors that influence the health condition are physical activity and nutrition. A high evaluation does not correspond to taking care of one’s health. Fewer than 8% of the female students practised sport in their free time and ate regularly. More than a half neither did sport nor ate regularly (Pearson’s contingency coefficient C reaches a value of 0.1. Conclusions : The female nursing students, contrary to the female students of other faculties, perceive health in the same way as the World Health Organisation. Regardless of faculty, physical activity and regular nutrition are considered to be

  3. Numerical relativity

    International Nuclear Information System (INIS)

    Piran, T.

    1982-01-01

    There are many recent developments in numerical relativity, but there remain important unsolved theoretical and practical problems. The author reviews existing numerical approaches to solution of the exact Einstein equations. A framework for classification and comparison of different numerical schemes is presented. Recent numerical codes are compared using this framework. The discussion focuses on new developments and on currently open questions, excluding a review of numerical techniques. (Auth.)

  4. The importance of community building for establishing data management and curation practices for physical samples

    Science.gov (United States)

    Ramdeen, S.; Hangsterfer, A.; Stanley, V. L.

    2017-12-01

    There is growing enthusiasm for curation of physical samples in the Earth Science community (see sessions at AGU, GSA, ESIP). Multiple federally funded efforts aim to develop best practices for curation of physical samples; however, these efforts have not yet been consolidated. Harmonizing these concurrent efforts would enable the community as a whole to build the necessary tools and community standards to move forward together. Preliminary research indicate the various groups focused on this topic are working in isolation, and the development of standards needs to come from the broadest view of `community'. We will investigate the gaps between communities by collecting information about preservation policies and practices from curators, who can provide a diverse cross-section of the grand challenges to the overall community. We will look at existing reports and study results to identify example cases, then develop a survey to gather large scale data to reinforce or clarify the example cases. We will be targeting the various community groups which are working on similar issues, and use the survey to improve the visibility of developed best practices. Given that preservation and digital collection management for physical samples are both important and difficult at present (GMRWG, 2015; NRC, 2002), barriers to both need to be addressed in order to achieve open science goals for the entire community. To address these challenges, EarthCube's iSamples, a research coordination network established to advance discoverability, access, and curation of physical samples using cyberinfrastructure, has formed a working group to collect use cases to examine the breadth of earth scientists' work with physical samples. This research team includes curators of state survey and oceanographic geological collections, and a researcher from information science. In our presentation, we will share our research and the design of the proposed survey. Our goal is to engage the audience in a

  5. Numerical study on physical mechanism of vortex breakdown occurrence in spin-up process

    OpenAIRE

    "小出, 輝明"; Teruaki", "Koide

    2008-01-01

    "A Numerical study presented on a vortex breakdown in spin-up process in an enclosed cylindrical container. In a transitional state, momentary vortex breakdowns can occur for particular parameter values ofthe Reynolds number and aspect ratio where no vortex breakdown appears in a steady state. This transient vortex breakdown flow is convenient to consider a mechanism for the occurrence of a vortex breakdown. It isdiscussed that periodical increase and decrease of angular momentum in upstream ...

  6. LNAPL infiltration in the vadose zone: Comparisons of physical and numerical simulations

    Energy Technology Data Exchange (ETDEWEB)

    Pantazidou, M. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    1995-03-01

    The numerical model T2VOC was used to reproduce light, nonaqueous phase liquid (LNAPL) infiltration scenarios in the vadose zone. The numerical modeling results were compared to results from laboratory experiments simulating LNAPL spills in the vadose zone. Laboratory measurements included results from one-dimensional column and two-dimensional tank experiments using uniform sands of varying average grain sizes. The constitutive relationships for the sands were obtained from the one-dimensional experiments. The two-dimensional experiments simulated leakage of kerosene under constant head. The sensitivity of the numerical results to the constitutive relationships used and the specified boundary conditions was examined. For this purpose two different capillary pressure-saturation relationships were used for the same sand and both constant head and constant flux conditions were obtained for the two capillary pressure curves used. The constant flux boundary conditions produced a much better prediction. At the initial stages of infiltration the results for both capillary pressure curves were similar and in good agreement with the experimental results. However, as the LNAPL front approaches the capillary fringe the choice of the capillary pressure curve was found to influence the results.

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

    International Nuclear Information System (INIS)

    Ivanov, P.; Kokhan, V.D.

    2001-01-01

    renders services related to physical protection and illicit trafficking to member states as well as is setting up the database and data-processing systems on illicit trafficking. The international regime should be based on national systems of combating illicit trafficking which include measures for prevention, detection and response regarding illicit trafficking in each specific state or across its borders. When undertaking these measures one should take into account specific characteristics of the state, its unique features and its geography, political and economic situation, as well as different types of potential threat of proliferation of nuclear weapons, availability of materials subjected to illicit trafficking in this state, general situation of criminal trafficking in this state, general situation of criminal trafficking with radioactive materials, potential consumers and suppliers, market features, possible incentives for crime etc. Vital components of national systems for combating illicit trafficking are: 1) legislation; 2) state control systems; 3) operator responsibilities; 4) physical protection of nuclear and radioactive materials and equipment; 5) export/import control of nuclear and radioactive materials and equipment; 6) clear definition of goals and responsibilities of national legislative authorities; 7) co-ordination of activities between national authorities as well as with international organizations. Eighty percent of all nuclear and radioactive materials in the Ukraine are concentrated at the companies and institutions supervised by the Ministry of Energy and Fuel. In view hereof we see the establishment of powerful and efficient systems of physical protection, accountancy and control directed against theft and unauthorized transportation of nuclear and radioactive materials as well as against acts of sabotage at nuclear installation performed by individuals or groups, as our contribution to combating illicit trafficking. These activities are

  8. Performance of overlapped shield tunneling through an integrated physical model tests, numerical simulations and real-time field monitoring

    Directory of Open Access Journals (Sweden)

    Junlong Yang

    2017-03-01

    Full Text Available In this work, deformations and internal forces of an existing tunnel subjected to a closely overlapped shield tunneling are monitored and analyzed using a series of physical model experiments and numerical simulations. Effects of different excavation sequences and speeds are explicitly considered in the analysis. The results of the physical model experiments show that the bottom-up tunneling procedure is better than the top-down tunneling procedure. The incurred deformations and internal forces of the existing tunnel increase with the excavation speed and the range of influence areas also increase accordingly. For construction process control, real-time monitoring of the power tunnel is used. The monitoring processes feature full automation, adjustable frequency, real-time monitor and dynamic feedback, which are used to guide the construction to achieve micro-disturbance control. In accordance with the situation of crossing construction, a numerical study on the performance of power tunnel is carried out. Construction control measures are given for the undercrossing construction, which helps to accomplish the desired result and meet protection requirements of the existing tunnel structure. Finally, monitoring data and numerical results are compared, and the displacement and joint fracture change models in the power tunnel subject to the overlapped shield tunnel construction are analyzed. Keywords: Overlapped tunnel, Automatic monitoring, Micro-disturbance control

  9. Are biological effects of desert shrubs more important than physical effects on soil microorganisms?

    Science.gov (United States)

    Berg, Naama; Steinberger, Yosef

    2010-01-01

    Vegetation cover plays a major role in providing organic matter and in acting as a physical barrier, with both together contributing to the formation of "fertile islands," which play an active role in prolonging biological activity in desert ecosystems. By undertaking this study, a longterm research, we designed an experiment to separate the two components-the physical and biotic parts of the perennial plants-and to identify the factor that contributes the most to the ecosystem. The study site was located in the northern Negev Desert, Israel, where 50 Hammada scoparia shrubs and 50 artificial plants were randomly marked. Soil samples were collected monthly over 3 years of research at three locations: under the canopy of H. scoparia shrubs, in the vicinity of the artificial plants, and between the shrubs (control). The contribution to microbial activity was measured by evaluation of the microbial community functions in soil. The functional aspects of the microbial community that were measured were CO2 evolution, microbial biomass, microbial functional diversity, and the physiological profile of the community. The results of this study are presented in two ways: (1) according to the three locations/treatments; and (2) according to the phenological situation of the vegetation (annual and perennial plants) in the research field: the growing phase, the drying process, and the absence of annual plants. The only parameters that were found to affect microbial activity were the contribution of the organic matter of perennial shrubs and the growth of vegetation (annual and perennial) during the growing seasons. The physical component was found to have no effect on soil microbial functional diversity, which elucidates the important contribution of the desert shrub in enhancing biological multiplicity and activity.

  10. Prediction of changes in important physical parameters during composting of separated animal slurry solid fractions.

    Science.gov (United States)

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-01-01

    Solid-liquid separation of animal slurry, with solid fractions used for composting, has gained interest recently. However, efficient composting of separated animal slurry solid fractions (SSFs) requires a better understanding of the process dynamics in terms of important physical parameters and their interacting physical relationships in the composting matrix. Here we monitored moisture content, bulk density, particle density and air-filled porosity (AFP) during composting of SSF collected from four commercially available solid-liquid separators. Composting was performed in laboratory-scale reactors for 30 days (d) under forced aeration and measurements were conducted on the solid samples at the beginning of composting and at 10-d intervals during composting. The results suggest that differences in initial physical properties of SSF influence the development of compost maximum temperatures (40-70 degreeC). Depending on SSF, total wet mass and volume losses (expressed as % of initial value) were up to 37% and 34%, respectively. After 30 d of composting, relative losses of total solids varied from 17.9% to 21.7% and of volatile solids (VS) from 21.3% to 27.5%, depending on SSF. VS losses in all composts showed different dynamics as described by the first-order kinetic equation. The estimated component particle density of 1441 kg m-3 for VS and 2625 kg m-3 for fixed solids can be used to improve estimates of AFP for SSF within the range tested. The linear relationship between wet bulk density and AFP reported by previous researchers held true for SSF.

  11. The reactor core configuration and important systems related to physics tests of Daya Bay NPP

    International Nuclear Information System (INIS)

    Tao Shaoping

    1995-06-01

    A brief introduction to reactor core configuration and important systems related to physics tests of Daya Bay NPP is given. These systems involve the reactor core system (COR), the full length rod control system (RGL), the in-core instrumentation system (RIC), the out-of-core nuclear instrumentation system (RPN), and the LOCA surveillance system (LSS), the centralized data processing system (KIT) and the test data acquisition system (KDO). In addition, that the adjustment and evaluation of boron concentration related to other systems, for example the reactor coolant system (RCP), the chemical and volume control system (RCV), the reactor boron and water makeup system (REA), the nuclear sampling system (REN) and the reactor control system (RRC), etc. is also described. Analysis of these systems helps not only to familiarize their functions and acquires a deepen understanding for the principle procedure, points for attention and technical key of the core physics tests, but also to further analyze the test results. (3 refs., 11 figs., 1 tab.)

  12. The importance of self-determined motivation towards physical activity in patients with schizophrenia.

    Science.gov (United States)

    Vancampfort, Davy; De Hert, Marc; Vansteenkiste, Maarten; De Herdt, Amber; Scheewe, Thomas W; Soundy, Andrew; Stubbs, Brendon; Probst, Michel

    2013-12-30

    There is a need for theoretically-based research on the motivational processes linked to the commencement and continuation of physical activity in patients with schizophrenia. Within the Self-Determination Theory (SDT) framework, we investigated the SDT tenets in these patients by examining the factor structure of the Behavioral Regulation in Exercise Questionnaire-2 (BREQ-2) and by investigating associations between motivation and PA. The secondary aim was to study differences in motivation according to gender, educational level, treatment setting and disease stage. A total of 129 patients (44♀) with schizophrenia agreed to participate. Exploratory factor analysis showed sufficient convergence with the original factor for amotivation, external and introjected regulation, while identified and intrinsic regulations loaded on a single factor which we labeled "autonomous regulation". Significant positive correlations were found between the total physical activity score and the subscales amotivation (r = -0.44, P important role in the adoption and maintenance of health promoting behaviors in patients with schizophrenia. © 2013 Published by Elsevier Ireland Ltd.

  13. Importance of physical infrastructure in the economic growth of municipalities in the northern border

    Directory of Open Access Journals (Sweden)

    Héctor Alonso Barajas Bustillos

    2012-01-01

    Full Text Available This paper evaluates the importance of infrastructure on economic growth for the Mexican northern border municipalities. From the growth literature, we know that infrastructure, besides other factors, has been pointed out as a key factor in the long run perspectives of regional growth. Nevertheless, and within this thematic context, works that use a disaggregated analysis down to the level of the municipality are still scarce, which in the case of the northern border constitutes a scenario of much relevance given the development model adopted by the Mexican economy in recent decades. Empirical models results indicate that the municipalities of Piedras Negras, Nogales and Torreon maintain a positive relationship between physical infrastructure and growth. In the case of other municipalities like Tijuana, its elevated population growth inhibits a proper infrastructure allocation, although the positive effect induced by infrastructure on growth remains.

  14. Physical Explanation of Archie's Porosity Exponent in Granular Materials: A Process-Based, Pore-Scale Numerical Study

    Science.gov (United States)

    Niu, Qifei; Zhang, Chi

    2018-02-01

    The empirical Archie's law has been widely used in geosciences and engineering to explain the measured electrical resistivity of many geological materials, but its physical basis has not been fully understood yet. In this study, we use a pore-scale numerical approach combining discrete element-finite difference methods to study Archie's porosity exponent m of granular materials over a wide porosity range. Numerical results reveal that at dilute states (e.g., porosity ϕ > 65%), m is exclusively related to the particle shape and orientation. As the porosity decreases, the electric flow in pore space concentrates progressively near particle contacts and m increases continuously in response to the intensified nonuniformity of the local electrical field. It is also found that the increase in m is universally correlated with the volume fraction of pore throats for all the samples regardless of their particle shapes, particle size range, and porosities.

  15. Quasi-optical converters for high-power gyrotrons: a brief review of physical models, numerical methods and computer codes

    International Nuclear Information System (INIS)

    Sabchevski, S; Zhelyazkov, I; Benova, E; Atanassov, V; Dankov, P; Thumm, M; Arnold, A; Jin, J; Rzesnicki, T

    2006-01-01

    Quasi-optical (QO) mode converters are used to transform electromagnetic waves of complex structure and polarization generated in gyrotron cavities into a linearly polarized, Gaussian-like beam suitable for transmission. The efficiency of this conversion as well as the maintenance of low level of diffraction losses are crucial for the implementation of powerful gyrotrons as radiation sources for electron-cyclotron-resonance heating of fusion plasmas. The use of adequate physical models, efficient numerical schemes and up-to-date computer codes may provide the high accuracy necessary for the design and analysis of these devices. In this review, we briefly sketch the most commonly used QO converters, the mathematical base they have been treated on and the basic features of the numerical schemes used. Further on, we discuss the applicability of several commercially available and free software packages, their advantages and drawbacks, for solving QO related problems

  16. Effect of water phase transition on dynamic ruptures with thermal pressurization: Numerical simulations with changes in physical properties of water

    Science.gov (United States)

    Urata, Yumi; Kuge, Keiko; Kase, Yuko

    2015-02-01

    Phase transitions of pore water have never been considered in dynamic rupture simulations with thermal pressurization (TP), although they may control TP. From numerical simulations of dynamic rupture propagation including TP, in the absence of any water phase transition process, we predict that frictional heating and TP are likely to change liquid pore water into supercritical water for a strike-slip fault under depth-dependent stress. This phase transition causes changes of a few orders of magnitude in viscosity, compressibility, and thermal expansion among physical properties of water, thus affecting the diffusion of pore pressure. Accordingly, we perform numerical simulations of dynamic ruptures with TP, considering physical properties that vary with the pressure and temperature of pore water on a fault. To observe the effects of the phase transition, we assume uniform initial stress and no fault-normal variations in fluid density and viscosity. The results suggest that the varying physical properties decrease the total slip in cases with high stress at depth and small shear zone thickness. When fault-normal variations in fluid density and viscosity are included in the diffusion equation, they activate TP much earlier than the phase transition. As a consequence, the total slip becomes greater than that in the case with constant physical properties, eradicating the phase transition effect. Varying physical properties do not affect the rupture velocity, irrespective of the fault-normal variations. Thus, the phase transition of pore water has little effect on dynamic ruptures. Fault-normal variations in fluid density and viscosity may play a more significant role.

  17. Physical barriers formed from gelling liquids: 1. numerical design of laboratory and field experiments

    International Nuclear Information System (INIS)

    Finsterle, S.; Moridis, G.J.; Pruess, K.; Persoff, P.

    1994-01-01

    The emplacement of liquids under controlled viscosity conditions is investigated by means of numerical simulations. Design calculations are performed for a laboratory experiment on a decimeter scale, and a field experiment on a meter scale. The purpose of the laboratory experiment is to study the behavior of multiple gout plumes when injected in a porous medium. The calculations for the field trial aim at designing a grout injection test from a vertical well in order to create a grout plume of a significant extent in the subsurface

  18. Numerical methods for solution of some nonlinear problems of mathematical physics

    International Nuclear Information System (INIS)

    Zhidkov, E.P.

    1981-01-01

    The continuous analog of the Newton method and its application to some nonlinear problems of mathematical physics using a computer is considered. It is shown that the application of this method in JINR to the wide range of nonlinear problems has shown its universality and high efficiency [ru

  19. High energy physics program: Task A, Experiment and theory; Task B, Numerical simulation

    International Nuclear Information System (INIS)

    1993-01-01

    This report discusses research in High Energy Physics at Florida State University. Contained in this paper are: highlights of activities during the past few years; five year summary; fixed target experiments; collider experiments; SSC preparation, detector development and detector construction; computing, networking and VAX upgrade to ALPHA; and particle theory programs

  20. Where and why hyporheic exchange is important: Inferences from a parsimonious, physically-based river network model

    Science.gov (United States)

    Gomez-Velez, J. D.; Harvey, J. W.

    2014-12-01

    Hyporheic exchange has been hypothesized to have basin-scale consequences; however, predictions throughout river networks are limited by available geomorphic and hydrogeologic data as well as models that can analyze and aggregate hyporheic exchange flows across large spatial scales. We developed a parsimonious but physically-based model of hyporheic flow for application in large river basins: Networks with EXchange and Subsurface Storage (NEXSS). At the core of NEXSS is a characterization of the channel geometry, geomorphic features, and related hydraulic drivers based on scaling equations from the literature and readily accessible information such as river discharge, bankfull width, median grain size, sinuosity, channel slope, and regional groundwater gradients. Multi-scale hyporheic flow is computed based on combining simple but powerful analytical and numerical expressions that have been previously published. We applied NEXSS across a broad range of geomorphic diversity in river reaches and synthetic river networks. NEXSS demonstrates that vertical exchange beneath submerged bedforms dominates hyporheic fluxes and turnover rates along the river corridor. Moreover, the hyporheic zone's potential for biogeochemical transformations is comparable across stream orders, but the abundance of lower-order channels results in a considerably higher cumulative effect for low-order streams. Thus, vertical exchange beneath submerged bedforms has more potential for biogeochemical transformations than lateral exchange beneath banks, although lateral exchange through meanders may be important in large rivers. These results have implications for predicting outcomes of river and basin management practices.

  1. Physical and Numerical Modeling of the Stability of Deep Caverns in Tahe Oil Field in China

    Directory of Open Access Journals (Sweden)

    Chao Wang

    2017-06-01

    Full Text Available Cave collapses emerge during the process of oil reservoir development, seriously affecting oil production. To reveal the collapse and failure mechanism of the carbonate cavern with a buried depth of 5600 m in Tahe Oil Field, using a self-developed ultra-high pressure model test system with the intelligent numerical control function, the model simulation material of carbonate rocks developed to carry out the 3D geo-mechanical model test. The model test and numerical results indicate that: (1 collapse and failure mechanism of the deep-buried caves mainly involve the failure mode of tensile shear. The rupture plane on the side wall is approximately parallel to the direction of maximum principal compressive stress. The V-type tension and split rupture plane then emerges. (2 In the process of forming holes in the model caverns, micro cracks are generated at the foot of the left and right side walls of the caverns, and the roof panels are constantly moving downward. The shorter the distance to the cave wall, the severer the destructiveness of the surrounding rocks will be. (3 The displacement of the top of the model cavern is relatively large and uniform, indicating that the cave roof moves downward as a whole. The area of the cavity suffering damage is 2.3 times as large as the cave span. The research results in this paper lay a solid test basis for revealing the cave collapse and failure mechanism in super depth.

  2. Grad-Shafranov reconstruction: overview and improvement of the numerical solution used in space physics

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda Gonzalez, A.; Domingues, M.O.; Mendes, O., E-mail: ojeda.gonzalez.a@gmail.com [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil); Kaibara, M.K. [Universidade Federal Fluminense (GMA/IME/UFF), Niteroi, RJ (Brazil); Prestes, A. [Universidade do Vale do Paraiba (IP and D/UNIVAP), Sao Jose dos Campos, SP (Brazil). Lab. de Fisica e Astronomia

    2015-10-15

    The Grad-Shafranov equation is a Poisson's equation, i.e., a partial differential equation of elliptic type. The problem is depending on the initial condition and can be treated as a Cauchy problem. Although it is ill-posed or ill-conditioned, it can be integrated numerically. In the integration of the GS equation, singularities with large values of the potential arise after a certain number of integration steps away from the original data line, and a filter should be used. The Grad-Shafranov reconstruction (GSR) technique was developed from 1996 to 2000 for recovering two-dimensional structures in the magnetopause in an ideal MHD formulation. Other works have used the GSR techniques to study magnetic flux ropes in the solar wind and in the magnetotail from a single spacecraft dataset; posteriorly, it was extended to treat measurements from multiple satellites. From Vlasov equation, it is possible to arrive at the GS-equation in function of the normalized vector potential. A general solution is obtained using complex variable theory. A specific solution was chosen as benchmark case to solve numerically the GS equation.We propose some changes in the resolution scheme of the GS equation to improve the solution. The result of each method is compared with the solution proposed by Hau and Sonnerup (J. Geophys. Res. 104(A4), 6899-6917 (1999)). The main improvement found in the GS resolution was the need to filter Bx values at each y value. (author)

  3. A physical and numerical modelling investigation of the roadway stability in longwall mining, with and without narrow pillar protection

    Energy Technology Data Exchange (ETDEWEB)

    Yavuz, H.; Fowell, R.J. [Suleyman Demirel University, Isparta (Turkey)

    2004-03-01

    The drivage of the supply gate of a development panel in the presumed low stress zone adjacent to the loader gate of an excavated panel with a very small width of intervening pillar between the two entries, known as skin-to-skin working, resulted in an extensive fall of the supply gate roof at Bilsthorpe colliery in 1993. This fall left a question over the application of skin-to-skin drivage of gate entries supported primarily by rock bolts. To investigate the possible reasons behind this fall, both physical and numerical modelling studies were carried out. Physical and numerical models were successful in demonstrating the potential danger of the working method with the rock bolt support system employed. Development of a shear failure plane from the rib edge into roof strata of the loader gate and development of the second shear failure plane at the abutment side of the supply gate exposed the supply gate to the fall of large rock blocks released by shear failure zones. Models demonstrated that the fall of the supply gate roof was not due to the inability of the rock bolts to prevent bed separation, but it was the method of working that made the bolts ineffective due to the height of the block delineated by the shear failure planes. Further physical and numerical models were undertaken to investigate the influence of 5, 7.5 and 10 in wide intervening pillars between the entries on the stability of the rock bolt supported supply gate roof. These studies showed that a 7.5 in or 10 in wide pillar would have prevented development of failure zones and fall of the roof while a 5 in pillar was found to be an undersized pillar width causing the development of extensive failure zones in the roof.

  4. Gender and motor competence affects perceived likelihood and importance of physical activity outcomes among 14 year olds.

    Science.gov (United States)

    Hands, B; Parker, H E; Rose, E; Larkin, D

    2016-03-01

    Perceptions of the effects of physical activity could facilitate or deter future participation. This study explored the differences between gender and motor competence at 14 years of age in the perceptions of likelihood and importance of physical activity outcomes. The sample comprised 1582 14-year-old adolescents (769 girls) from the Western Australian Pregnancy Cohort (Raine) Study. Four motor competence groups were formed from a standardized Neuromuscular Developmental Index score (McCarron 1997). Perceptions of the likelihood and the importance of 15 physical activity outcomes were measured by a questionnaire developed for the NSW Schools Fitness and Physical Activity Survey (Booth et al. 1997). Gender (two) × motor competence (four) analyses of variance and Tukey post hoc were conducted on outcome scores (P importance of physical activity outcomes within competition, social friendships and injury domains. Motor competence was significant in the perceived likelihood of physical health (P importance was perceived for academic outcomes for 14 year olds categorized with low compared with high motor competence (P importance. Although level of motor competence at 14 years affected the perceived likelihood of health, social and fun outcomes from future participation in physical activity, adolescents highly valued these outcomes, whereas gender affected competition and winning, outcomes that were less valued. Physical activity that promotes these key and valued outcomes may encourage young people's ongoing involvement in physical activity, especially for those at risk of low participation. © 2015 John Wiley & Sons Ltd.

  5. Open die forging of large shafts with porosity defects – physical and numerical modelling

    DEFF Research Database (Denmark)

    Christiansen, Peter; Hattel, Jesper Henri; Bay, Niels

    2013-01-01

    The aim and scope of this paper is centered to analyze the influence of the geometry of V-shaped dies on the closure of internal centerline porosity defects in ingots during multistep open-die forging. The investigation is performed with small scale physical models made from lead using V-shaped d......The aim and scope of this paper is centered to analyze the influence of the geometry of V-shaped dies on the closure of internal centerline porosity defects in ingots during multistep open-die forging. The investigation is performed with small scale physical models made from lead using V......-shaped dies with 90o and 120o and a reference pair of flat parallel platens. Holes drilled through the center of these preforms are produced to mimic centerline porosity in full scale cast ingots and intermediate rotation of the preforms replicate a multi-stage forging sequence under laboratory testing...

  6. Physical activity: The importance of the extended theory of planned behavior, in type 2 diabetes patients.

    Science.gov (United States)

    Ferreira, Gabriela; Pereira, M Graça

    2017-09-01

    This study focused on the contribution of the extended theory of planned behavior regarding intention to perform physical activity, adherence to physical activity, and its mediator role in the relationship between trust in the physician and adherence to physical activity, in a sample of 120 patients with type 2 diabetes. The results revealed that positive attitudes and perception of control predicted a stronger intention to do physical activity. The intention to do physical activity was the only predictor of adherence to physical activity. Planning mediated the relationship between trust in the physician and adherence. Implications for patients with type 2 diabetes are discussed.

  7. Numerical modeling of time domain 3-D problems in accelerator physics

    International Nuclear Information System (INIS)

    Harfoush, F.A.; Jurgens, T.G.

    1990-06-01

    Time domain analysis is relevant in particle accelerators to study the electromagnetic field interaction of a moving source particle on a lagging test particle as the particles pass an accelerating cavity or some other structure. These fields are called wake fields. The travelling beam inside a beam pipe may undergo more complicated interactions with its environment due to the presence of other irregularities like wires, thin slots, joints and other types of obstacles. Analytical solutions of such problems is impossible and one has to resort to a numerical method. In this paper we present results of our first attempt to model these problems in 3-D using our finite difference time domain (FDTD) code. 10 refs., 9 figs

  8. A NUMERICAL SIMULATION OF COSMIC RAY MODULATION NEAR THE HELIOPAUSE. II. SOME PHYSICAL INSIGHTS

    International Nuclear Information System (INIS)

    Luo, Xi; Feng, Xueshang; Potgieter, Marius S.; Du Toit Strauss, R.; Zhang, Ming; Pogorelov, Nikolai V.

    2016-01-01

    Cosmic ray (CR) transport near the heliopause (HP) is studied using a hybrid transport model, with the parameters constrained by observations from the Voyager 1 spacecraft. We simulate the CR radial flux along different directions in the heliosphere. There is no well-defined thin layer between the solar wind region and the interstellar region along the tail and polar directions of the heliosphere. By analyzing the radial flux curve along the direction of Voyager 2 , together with its trajectory information, the crossing time of the HP by Voyager 2 is predicted to be in 2017.14. We simulate the CR radial flux for different energy values along the direction of Voyager 1 . We find that there is only a modest modulation region of about 10 au wide beyond the HP, so that Voyager 1 observing the Local Interstellar Spectra is justified in numerical modeling. We analyze the heliospheric exit information of pseudo-particles in our stochastic numerical (time-backward) method, conjecturing that they represent the behavior of CR particles, and we find that pseudo-particles that have been traced from the nose region exit in the tail region. This implies that many CR particles diffuse directly from the heliospheric tail region to the nose region near the HP. In addition, when pseudo-particles were traced from the Local Interstellar Medium (LISM), it is found that their exit location (entrance for real particles) from the simulation domain is along the prescribed Interstellar Magnetic Field direction. This indicates that parallel diffusion dominates CR particle transport in the LISM.

  9. The importance of non-exercise physical activity for cardiovascular health and longevity.

    Science.gov (United States)

    Ekblom-Bak, Elin; Ekblom, Björn; Vikström, Max; de Faire, Ulf; Hellénius, Mai-Lis

    2014-02-01

    Sedentary time is increasing in all societies and results in limited non-exercise physical activity (NEPA) of daily life. The importance of low NEPA for cardiovascular health and longevity is limited, especially in elderly. To examine the association between NEPA and cardiovascular health at baseline as well as the risk of a first cardiovascular disease (CVD) event and total mortality after 12.5 years. Cohort study. Every third 60-year-old man and woman in Stockholm County was invited to a health screening study; 4232 individuals participated (78% response rate). At baseline, NEPA and exercise habits were assessed from a self-administrated questionnaire and cardiovascular health was established through physical examinations and laboratory tests. The participants were followed for an average of 12.5 years for the assessment of CVD events and mortality. At baseline, high NEPA was, regardless of regular exercise and compared with low NEPA, associated with more preferable waist circumference, high-density lipoprotein cholesterol and triglycerides in both sexes and with lower insulin, glucose and fibrinogen levels in men. Moreover, the occurrence of the metabolic syndrome was significantly lower in those with higher NEPA levels in non-exercising and regularly exercising individuals. Furthermore, reporting a high NEPA level, compared with low, was associated with a lower risk of a first CVD event (HR=0.73; 95% CI 0.57 to 0.94) and lower all-cause mortality (0.70; 0.53 to 0.98). A generally active daily life was, regardless of exercising regularly or not, associated with cardiovascular health and longevity in older adults.

  10. The Importance of Indirect Teaching Behaviour and Its Educational Effects in Physical Education

    Science.gov (United States)

    Jung, Hyunwoo; Choi, Euichang

    2016-01-01

    Background: Physical education teacher behaviour has been a subject of study in physical education including physical education teacher education for 30 years. However, the research on teacher behaviour has tended to focus on direct teaching behaviour (DTB) to demonstrate the benefits of effective teaching, centred on a technical understanding of…

  11. The importance of the social environment for physically active lifestyle: results from an international study.

    NARCIS (Netherlands)

    Stahl, T.; Rütten, A.; Nutbeam, D.; Bauman, A.; Kannas, L.; Abel, T.; Lüschen, G.; Rodríguez Diaz, J.A.; Vinck, J.; Zee, J. van der

    2001-01-01

    Physically active lifestyles are regularly associated with improved health and quality of life. Differences in lifestyles in society can partly be understood through the differences in the social and physical environment. This study examines the relationships between reported physical activity, and

  12. Physical models, cross sections, and numerical approximations used in MCNP and GEANT4 Monte Carlo codes for photon and electron absorbed fraction calculation.

    Science.gov (United States)

    Yoriyaz, Hélio; Moralles, Maurício; Siqueira, Paulo de Tarso Dalledone; Guimarães, Carla da Costa; Cintra, Felipe Belonsi; dos Santos, Adimir

    2009-11-01

    Radiopharmaceutical applications in nuclear medicine require a detailed dosimetry estimate of the radiation energy delivered to the human tissues. Over the past years, several publications addressed the problem of internal dose estimate in volumes of several sizes considering photon and electron sources. Most of them used Monte Carlo radiation transport codes. Despite the widespread use of these codes due to the variety of resources and potentials they offered to carry out dose calculations, several aspects like physical models, cross sections, and numerical approximations used in the simulations still remain an object of study. Accurate dose estimate depends on the correct selection of a set of simulation options that should be carefully chosen. This article presents an analysis of several simulation options provided by two of the most used codes worldwide: MCNP and GEANT4. For this purpose, comparisons of absorbed fraction estimates obtained with different physical models, cross sections, and numerical approximations are presented for spheres of several sizes and composed as five different biological tissues. Considerable discrepancies have been found in some cases not only between the different codes but also between different cross sections and algorithms in the same code. Maximum differences found between the two codes are 5.0% and 10%, respectively, for photons and electrons. Even for simple problems as spheres and uniform radiation sources, the set of parameters chosen by any Monte Carlo code significantly affects the final results of a simulation, demonstrating the importance of the correct choice of parameters in the simulation.

  13. Importance of physical qualities for speed and change of direction ability in elite female soccer players.

    Science.gov (United States)

    Emmonds, Stacey; Nicholson, G; Beggs, C; Jones, B; Bissas, A

    2017-07-17

    The purpose of this study was to determine the importance of physical qualities for speed and change of direction (CoD) ability in female soccer players. Data were collected on 10 female soccer players who were part of a professional English Women's Super League team. Player assessments included anthropometric (stature and body mass), body composition (dual-energy X-ray absorptiometry), speed (10m, 30m sprint), CoD ability (505 agility), aerobic (Yo-Yo Intermittent Recovery Test), lower-body strength (bilateral knee extensions) and power (countermovement jump [CMJ], squat jump [SJ], 30cm drop jump [DJ]) measures. The relationships between the variables were evaluated using eigenvector analysis and Pearson correlation analysis. Multiple linear regression revealed that the performance variables (10 and 20m speed, mean 505, and CoD deficit mean) can be predicted with almost 100% accuracy (i.e. adjusted R > 0.999) using various combinations of the predictor variables (DJ height, CMJ height, SJ height, lean body mass). An increase of one standard deviation (SD) in DJ height was associated with reductions of -5.636 and -9.082 SD in 10 m and 20 m sprint times. A one SD increase in CMJ also results in a reduction of -3.317 and -0.922 SD respectively in mean 505 and CoD deficit mean values. This study provides comparative data for professional English female soccer players that can be used by strength and conditioning coaches when monitoring player development and assessing the effectiveness of training programmes. Findings highlight the importance of developing reactive strength to improve speed and CoD ability in female soccer players.

  14. Physical and numerical investigation of the flow induced vibration of the hydrofoil

    Science.gov (United States)

    Wu, Q.; Wang, G. Y.; Huang, B.

    2016-11-01

    The objective of this paper is to investigate the flow induced vibration of a flexible hydrofoil in cavitating flows via combined experimental and numerical studies. The experiments are presented for the modified NACA66 hydrofoil made of POM Polyacetate in the closed-loop cavitation tunnel at Beijing Institute of Technology. The high-speed camera and the single point Laser Doppler Vibrometer are applied to analyze the transient flow structures and the corresponding structural vibration characteristics. The hybrid coupled fluid structure interaction model is conducted to couple the incompressible and unsteady Reynolds Averaged Navier-Stokes solver with a simplified two-degree-of-freedom structural model. The k-ω SST turbulence model with the turbulence viscosity correction and the Zwart cavitation model are introduced to the present simulations. The results showed that with the decreasing of the cavitation number, the cavitating flows display incipient cavitation, sheet cavitation, cloud cavitation and supercavitation. The vibration magnitude increases dramatically for the cloud cavitation and decline for the supercavitation. The cloud cavitation development strongly affects the vibration response, which is corresponding to the periodically developing and shedding of the large-scale cloud cavity. The main frequency of the vibration amplitude is accordance with the cavity shedding frequency and other two frequencies of the vibration amplitude are corresponding to the natural frequencies of the bending and twisting modes.

  15. Dry calibration of electromagnetic flowmeters based on numerical models combining multiple physical phenomena (multiphysics)

    Science.gov (United States)

    Fu, X.; Hu, L.; Lee, K. M.; Zou, J.; Ruan, X. D.; Yang, H. Y.

    2010-10-01

    This paper presents a method for dry calibration of an electromagnetic flowmeter (EMF). This method, which determines the voltage induced in the EMF as conductive liquid flows through a magnetic field, numerically solves a coupled set of multiphysical equations with measured boundary conditions for the magnetic, electric, and flow fields in the measuring pipe of the flowmeter. Specifically, this paper details the formulation of dry calibration and an efficient algorithm (that adaptively minimizes the number of measurements and requires only the normal component of the magnetic flux density as boundary conditions on the pipe surface to reconstruct the magnetic field involved) for computing the sensitivity of EMF. Along with an in-depth discussion on factors that could significantly affect the final precision of a dry calibrated EMF, the effects of flow disturbance on measuring errors have been experimentally studied by installing a baffle at the inflow port of the EMF. Results of the dry calibration on an actual EMF were compared against flow-rig calibration; excellent agreements (within 0.3%) between dry calibration and flow-rig tests verify the multiphysical computation of the fields and the robustness of the method. As requiring no actual flow, the dry calibration is particularly useful for calibrating large-diameter EMFs where conventional flow-rig methods are often costly and difficult to implement.

  16. Numerical Aspects of Atomic Physics: Helium Basis Sets and Matrix Diagonalization

    Science.gov (United States)

    Jentschura, Ulrich; Noble, Jonathan

    2014-03-01

    We present a matrix diagonalization algorithm for complex symmetric matrices, which can be used in order to determine the resonance energies of auto-ionizing states of comparatively simple quantum many-body systems such as helium. The algorithm is based in multi-precision arithmetic and proceeds via a tridiagonalization of the complex symmetric (not necessarily Hermitian) input matrix using generalized Householder transformations. Example calculations involving so-called PT-symmetric quantum systems lead to reference values which pertain to the imaginary cubic perturbation (the imaginary cubic anharmonic oscillator). We then proceed to novel basis sets for the helium atom and present results for Bethe logarithms in hydrogen and helium, obtained using the enhanced numerical techniques. Some intricacies of ``canned'' algorithms such as those used in LAPACK will be discussed. Our algorithm, for complex symmetric matrices such as those describing cubic resonances after complex scaling, is faster than LAPACK's built-in routines, for specific classes of input matrices. It also offer flexibility in terms of the calculation of the so-called implicit shift, which is used in order to ``pivot'' the system toward the convergence to diagonal form. We conclude with a wider overview.

  17. Physical Experiment and Numerical Simulation of the Artificial Recharge Effect on Groundwater Reservoir

    Directory of Open Access Journals (Sweden)

    Yang Xu

    2017-11-01

    Full Text Available To improve the efficiency of utilizing water resources in arid areas, the mechanism of artificial recharge effecting on groundwater reservoir was analyzed in this research. Based on a generalized groundwater reservoir in a two-dimensional sand tank model, different scenarios of the infiltration basin location and recharge intensity are designed to study how to improve the efficiency of groundwater reservoir artificial recharge. The effective storage capacity and the effective storage rate are taken as the main parameters to analyze the relation between recharge water volume and storage capacity. By combining with groundwater flow system theory, FEFLOW (Finite Element subsurface FLOW system is adopted to set up the groundwater numerical model. It is used to verify the experiment results and to make deep analysis on the rule of water table fluctuations and groundwater movement in the aquifer. Based on the model, different scenarios are designed to examine the combined effect of recharge intensity and intermittent periods. The research results show that: the distance between infiltration basin and pumping well should be shortened appropriately, but not too close; increasing recharge intensity helps to enlarge the effective storage capacity, but it can also reduce the effective storage rate, which goes against the purpose of effective utilization of water resources; and, the recharge intensity and recharge duration should be given full consideration by the actual requirements when we take the approach of intermittent recharge to make a reasonable choice.

  18. The importance of the human factor in a physical protection system

    International Nuclear Information System (INIS)

    Silva, A.; Rocha, A.

    2002-01-01

    Full text: A complete physical protection system gathers three elements: equipment's, guards and procedures. The integration of these three elements will guarantee the efficiency of the overall PPS in such a way that it can meet the objectives that were defined during its project: clear and precise procedures will rule the relation between the technical factor (equipments/ hardware and software) and the human factor (guards). The technical factor is easily adapted ad upgraded to continue meet the objectives of the PPS; however, the human factor presents some resistance, internal and external, concerning the performance of its function within the overall PPS. The objective of this paper is to show the importance of the human factor as an integrant part of the PPS of a nuclear facility. 1. Good relationship between guards and other employees in a facility; 2. the knowledge and acceptance of rules and procedures; 3. and the awareness of the needing to implement security measures, as well as the cooperation with these measures to avoid unauthorized nuclear material removal from the facility or sabotage with consequent radioactive release will guarantee the success of the human factor within the overall PPS. In countries where there is no recent record of terrorist activities, as in Brazil's case, these three key factors are particularly critical, once the concept of security culture is not present in those people's way of life. The target public of this survey are the employees, including the guards of the security force, of the CNAAA - Central Nuclear Almirante Alvaro Alberto - consisting of Angra 1 and Angra 2 nuclear power plants. The tools used to came up with the conclusions of this work were two different kinds of questionnaires: a) one of the questionnaires was answered by the guards of the security force concerning their feelings or impressions about other employees' knowledge, acceptance and cooperation of/with the security measures applied on site, and their

  19. Thrust initiation and its control on tectonic wedge geometry: An insight from physical and numerical models

    Science.gov (United States)

    Bose, Santanu; Mandal, Nibir; Saha, Puspendu; Sarkar, Shamik; Lithgow-Bertelloni, Carolina

    2014-10-01

    We performed a series of sandbox experiments to investigate the initiation of thrust ramping in tectonic wedges on a mechanically continuous basal decollement. The experiments show that the decollement slope (β) is the key factor in controlling the location of thrust initiation with respect to the backstop (i.e. tectonic suture line). For β = 0, the ramping begins right at the backstop, followed by sequential thrusting in the frontal direction, leading to a typical mono-vergent wedge. In contrast, the ramp initiates away from the backstop as β > 0. Under this boundary condition an event of sequential back thrusting takes place prior to the onset of frontal thrust progression. These two-coupled processes eventually give rise to a bi-vergent geometry of the thrust wedge. Using the Drucker-Prager failure criterion in finite element (FE) models, we show the location of stress intensification to render a mechanical basis for the thrust initiation away from the backstop if β > 0. Our physical and FE model results explain why the Main Central Thrust (MCT) is located far away from the Indo-Tibetan plate contact (ITSZ) in the Himalayan fold-and-thrust belts.

  20. ADAPTIVE MESH REFINEMENT SIMULATIONS OF GALAXY FORMATION: EXPLORING NUMERICAL AND PHYSICAL PARAMETERS

    International Nuclear Information System (INIS)

    Hummels, Cameron B.; Bryan, Greg L.

    2012-01-01

    We carry out adaptive mesh refinement cosmological simulations of Milky Way mass halos in order to investigate the formation of disk-like galaxies in a Λ-dominated cold dark matter model. We evolve a suite of five halos to z = 0 and find a gas disk formation in each; however, in agreement with previous smoothed particle hydrodynamics simulations (that did not include a subgrid feedback model), the rotation curves of all halos are centrally peaked due to a massive spheroidal component. Our standard model includes radiative cooling and star formation, but no feedback. We further investigate this angular momentum problem by systematically modifying various simulation parameters including: (1) spatial resolution, ranging from 1700 to 212 pc; (2) an additional pressure component to ensure that the Jeans length is always resolved; (3) low star formation efficiency, going down to 0.1%; (4) fixed physical resolution as opposed to comoving resolution; (5) a supernova feedback model that injects thermal energy to the local cell; and (6) a subgrid feedback model which suppresses cooling in the immediate vicinity of a star formation event. Of all of these, we find that only the last (cooling suppression) has any impact on the massive spheroidal component. In particular, a simulation with cooling suppression and feedback results in a rotation curve that, while still peaked, is considerably reduced from our standard runs.

  1. Understanding the Flow Physics of Shock Boundary-Layer Interactions Using CFD and Numerical Analyses

    Science.gov (United States)

    Friedlander, David J.

    2013-01-01

    Computational fluid dynamic (CFD) analyses of the University of Michigan (UM) Shock/Boundary-Layer Interaction (SBLI) experiments were performed as an extension of the CFD SBLI Workshop held at the 48th AIAA Aerospace Sciences Meeting in 2010. In particular, the UM Mach 2.75 Glass Tunnel with a semi-spanning 7.75deg wedge was analyzed in attempts to explore key physics pertinent to SBLI's, including thermodynamic and viscous boundary conditions as well as turbulence modeling. Most of the analyses were 3D CFD simulations using the OVERFLOW flow solver, with additional quasi-1D simulations performed with an in house MATLAB code interfacing with the NIST REFPROP code to explore perfect verses non-ideal air. A fundamental exploration pertaining to the effects of particle image velocimetry (PIV) on post-processing data is also shown. Results from the CFD simulations showed an improvement in agreement with experimental data with key contributions including adding a laminar zone upstream of the wedge and the necessity of mimicking PIV particle lag for comparisons. Results from the quasi-1D simulation showed that there was little difference between perfect and non-ideal air for the configuration presented.

  2. Importance of root HTO uptake in controlling land-surface tritium dynamics after an-acute HT deposition: a numerical experiment

    International Nuclear Information System (INIS)

    Ota, Masakazu; Nagai, Haruyasu; Koarashi, Jun

    2012-01-01

    To investigate the role of belowground root uptake of tritiated water (HTO) in controlling land-surface tritium (T) dynamics, a sophisticated numerical model predicting tritium behavior in an atmosphere-vegetation-soil system was developed, and numerical experiments were conducted using the model. The developed model covered physical tritiated hydrogen (HT) transport in a multilayered atmosphere and soil, as well as microbial oxidation of HT to HTO in the soil, and it was incorporated into a well-established HTO-transfer organically bound tritium (OBT)-formation model. The model performance was tested through the simulation of an existing HT-release experiment. Numerical experiments involving a hypothetical acute HT exposure to a grassland field with a range of rooting depths showed that the HTO release from the leaves to the atmosphere, driven by the root uptake of the deposited HTO, can exceed the HTO evaporation from the ground surface to the atmosphere when root water absorption preferentially occurs beneath the ground surface. Such enhanced soil-leaf-atmosphere HTO transport, caused by the enhanced root HTO uptake, increased HTO concentrations in both the surface atmosphere and in the cellular water of the leaf. Consequently, leaf OBT assimilation calculated for shallow rooting depths increased by nearly an order of magnitude compared to that for large rooting depths. - Highlights: ► A model that calculates HT deposition from atmosphere to soil was developed. ► Tritium dynamics after an-acute HT deposition was studied by numerical experiments. ► OBT formation highly depends on magnitude of uptake of the deposited HTO by roots.

  3. PHYSICAL ACTIVITY AND ITS IMPORTANCE FOR THE PREVENTION OF CARDIOVASCULAR DISEASES

    Directory of Open Access Journals (Sweden)

    S. S. Yakushin

    2015-01-01

    Full Text Available Lack of physical activity (PA is today one of the most important risk factors for atherosclerosis­related deaths. Its level is falling worldwide. A study in the UK, USA, India, Brazil and China (45 % of the world population total PA declined in these countries and will continue to fall over the next 15 years. In Russia, the level of the PA population decreased. PA is responsible for 12.2 % of the global burden of myo­ cardial infarction. These more than 40 observational studies demonstrate the complete proofs of the linear relationship between the level of PA and total mortality in younger and older men and women. The minimum threshold PA, which can reduce the risk of all­cause mortal­ ity is at a level of 2.5–5 hours a week. Further increase of the PA (its duration and/or intensity leads to a further reduction of risks. PA should take most days of the week and have a duration of more than 10 minutes a day. Only then did she summed up. In patients with cardiovascular disease to determine the necessary level of PA is difficult. Therefore, before the training they have to undergo stress testing. The program of training should be determined on the basis of findings and the clinical status. Even brief moderate and/or intense exercise can reduce the risk of death of the patient. If an individual does not reach the target of 150 minutes of moderate PA per week, but has been a regular, his risk of CHD was significantly reduced (14 %, 95 % CI 0.76–0.97. The development of programs to improve the PA of the population can have a significant impact on the overall and cardiovascular mortality. 

  4. Physical activity and the recreation opportunity spectrum: differences in important site attributes and perceived constraints

    Science.gov (United States)

    S.A. Wilhelm Stanis; I.E. Schneider; K.J. Sinew; D.J. Chavez; M.C. Vogel

    2009-01-01

    Both legislation and professional organizations call for parks and recreation agencies to address the need for greater physical activity among those living in the United States. A greater understanding of factors that facilitate and constrain physical activity in parks and recreation areas may improve agencies’ ability to address obesity and sedentary lifestyles. This...

  5. Urban-rural differences in physical activity in Belgian adults and the importance of psychosocial factors.

    Science.gov (United States)

    Dyck, Delfien Van; Cardon, Greet; Deforche, Benedicte; De Bourdeaudhuij, Ilse

    2011-02-01

    Recent research in urban planning and public health has drawn attention to the associations between urban form and physical activity in adults. Because little is known on the urban-rural differences in physical activity, the main aims of the present study were to examine differences in physical activity between urban and rural adults and to investigate the moderating effects of the physical environment on the relationship between psychosocial factors and physical activity. In Flanders, Belgium, five rural and five urban neighborhoods were selected. A sample of 350 adults (20-65 years of age; 35 adults per neighborhood) participated in the study. Participants wore a pedometer for 7 days, and self-reported physical activity and psychosocial data were also collected. Results showed that urban adults took more steps/day and reported more walking and cycling for transport in the neighborhood, more recreational walking in the neighborhood, and more walking for transportation outside the neighborhood than rural adults. Rural adults reported more recreational cycling in the neighborhoods. The physical environment was a significant moderator of the associations between several psychosocial factors (modeling from family, self-efficacy, and perceived barriers) and physical activity. In rural participants, adults with psychosocial scores above average were more physically active, whereas there were no differences in physical activity according to psychosocial factors in urban participants. These results are promising and plead for the development of multidimensional interventions, targeting specific population subgroups. In rural environments, where changing the environment would be a very challenging task, interventions focusing on modifiable psychosocial constructs could possibly be effective.

  6. The Importance of Leisure Activities in the Relationship between Physical Health and Well-Being in a Life Span Sample.

    Science.gov (United States)

    Paggi, Michelle E; Jopp, Daniela; Hertzog, Christopher

    2016-01-01

    Previous studies have examined the relationships between physical health and leisure activities and between leisure activities and well-being, but, to our knowledge, none has examined these relationships simultaneously. This study investigated the relationships between leisure activities, health and well-being considering the role of age, and whether leisure activities mediate the relationship between physical health and well-being. Utilizing a cross-sectional database of 259 adults (ages 18-81 years) who completed several questionnaires, linear regression models and mediation models were tested. Regression analyses indicated that physical health was related to leisure activities and leisure activities were related to well-being. When physical health was measured by subjective ratings, age had a stronger relationship with leisure activities. However, when physical health was indicated by health restrictions, physical health had a stronger relationship with leisure activities than did age. Leisure activities were a partial mediator of the relationship between physical health and well-being. The results demonstrated that the reduction in leisure activities with age has more to do with physical health limitations than with older age itself. In addition, regardless of age, the benefits of physical health for well-being are due in part to the level of leisure activity participation. These results highlight the importance of leisure activities for successful aging throughout the adult life span. Interventions designed to improve well-being through increasing leisure activity participation should take physical health into consideration, particularly for older adults. © 2016 S. Karger AG, Basel.

  7. Second-order theory for coupling 2D numerical and physical wave tanks: Derivation, evaluation and experimental validation

    DEFF Research Database (Denmark)

    Yang, Zhiwen; Liu, Shuxue; Bingham, Harry B.

    2013-01-01

    , 171–186] is extended to include the second-order dispersive correction. The new formulation is presented in a unified form that includes both progressive and evanescent modes and covers wavemaker configurations of the piston- and flap-type. The second order paddle stroke correction allows for improved...... nonlinear wave generation in the physical wave tank based on target numerical solutions. The performance and efficiency of the new model is first evaluated theoretically based on second order Stokes waves. Due to the complexity of the problem, the proposed method has been truncated at 2D and the treatment...... that the new second-order coupling theory provides an improvement in the quality of nonlinear wave generation when compared to existing techniques....

  8. Internet and Democracy: Is the Internet an Important Predictor for Physical Education Teacher Candidates' Attitudes towards Democracy?

    Science.gov (United States)

    Ünlü, Hüseyin

    2017-01-01

    Today, in the digital age, the Internet usage is common among university students. The Internet is also an important platform for actively participating in democracy. This study explores physical education (PE) candidate teachers' attitudes toward the Internet and democracy. It also explores whether the Internet is an important predictor for…

  9. Numerical modeling of solute transport in a sand tank physical model under varying hydraulic gradient and hydrological stresses

    Science.gov (United States)

    Atlabachew, Abunu; Shu, Longcang; Wu, Peipeng; Zhang, Yongjie; Xu, Yang

    2018-03-01

    This laboratory study improves the understanding of the impacts of horizontal hydraulic gradient, artificial recharge, and groundwater pumping on solute transport through aquifers. Nine experiments and numerical simulations were carried out using a sand tank. The variable-density groundwater flow and sodium chloride transport were simulated using the three-dimensional numerical model SEAWAT. Numerical modelling results successfully reproduced heads and concentrations observed in the sand tank. A higher horizontal hydraulic gradient enhanced the migration of sodium chloride, particularly in the groundwater flow direction. The application of constant artificial recharge increased the spread of the sodium chloride plume in both the longitudinal and lateral directions. In addition, groundwater pumping accelerated spreading of the sodium chloride plume towards the pumping well. Both higher hydraulic gradient and pumping rate generated oval-shaped plumes in the horizontal plane. However, the artificial recharge process produced stretched plumes. These effects of artificial recharge and groundwater pumping were greater under higher hydraulic gradient. The concentration breakthrough curves indicated that emerging solutions never attained the concentration of the originally injected solution. This is probably because of sorption of sodium chloride onto the silica sand and/or the exchange of sodium chloride between the mobile and immobile liquid domains. The fingering and protruding plume shapes in the numerical models constitute instability zones produced by buoyancy-driven flow. Overall, the results have substantiated the influences of hydraulic gradient, boundary condition, artificial recharge, pumping rate and density differences on solute transport through a homogeneous unconfined aquifer. The implications of these findings are important for managing liquid wastes.

  10. Numerical analysis

    CERN Document Server

    Khabaza, I M

    1960-01-01

    Numerical Analysis is an elementary introduction to numerical analysis, its applications, limitations, and pitfalls. Methods suitable for digital computers are emphasized, but some desk computations are also described. Topics covered range from the use of digital computers in numerical work to errors in computations using desk machines, finite difference methods, and numerical solution of ordinary differential equations. This book is comprised of eight chapters and begins with an overview of the importance of digital computers in numerical analysis, followed by a discussion on errors in comput

  11. Acute vascular effects of waterpipe smoking: Importance of physical activity and fitness status.

    Science.gov (United States)

    Alomari, Mahmoud A; Khabour, Omar F; Alzoubi, Karem H; Shqair, Dana M; Stoner, Lee

    2015-06-01

    While new forms of tobacco, including waterpipe (WP) smoking, continue to gain popularity, limited literature has examined the vascular health consequences. The purpose of the current study was to examine: (i) the acute WP-induced changes in vascular function; (ii) whether acute changes in vascular function are modified by lifestyle behaviors (habitual physical activity, physical fitness). Fifty three (22.7 y, 36% F, 23.4 kg/m(2)) otherwise healthy WP smokers were recruited. Strain-gauge plethysmography was used to measure forearm blood flow, vascular resistance, venous capacitance, and venous outflow at rest and following occlusion. Habitual physical activity was determined using the Arabic version of short-form international physical activity questionnaire, while physical fitness was assessed using the 6 min walk test and handgrip strength. Partial correlations were used to examine the relationships between post-smoking vascular function and lifestyle behaviors, controlling for pre-smoking vascular measures. (i) WP had a small effect on forearm post-occlusion blood flow (d = -0.19), a moderate effect on venous outflow (d = 0.30), and a moderate effect on post-occlusion vascular resistance (d = 0.32). (ii) Total habitual physical activity strongly correlated with resting blood flow (r = 0.50) and moderately with vascular resistance (r = -0.40). Handgrip strength moderately correlated with venous capacitance (r = 0.30) and post-occlusion blood flow (r = 0.30), while 6 min walked distance moderately correlated with resting venous capacitance (r = 0.30). Waterpipe smoking is associated with immediate changes in vascular function, which are exacerbated in individuals with low habitual physical activity and physical fitness levels in young otherwise healthy individuals. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. A Qualitative Study of Environmental Factors Important for Physical Activity in Rural Adults.

    Science.gov (United States)

    Cleland, Verity; Hughes, Clarissa; Thornton, Lukar; Venn, Alison; Squibb, Kathryn; Ball, Kylie

    2015-01-01

    Despite increasing evidence that the physical environment impacts on physical activity among urban-dwellers, little attention has been devoted to understanding this relationship in rural populations. Work in this area is further hindered by a lack of environmental measures specifically designed for rural settings. This qualitative study aimed to explore the salience of urban physical activity environment constructs among rural adults. In 2011, 49 rural men and women from three distinct areas (coastal, animal-based farming, forestry/plant-based farming) of rural Tasmania, Australia, were purposively recruited to participate in semi-structured interviews. Interviews explored features of the built and social environment commonly examined in studies of urban adults, including functional characteristics (eg, lighting, footpaths, roads/verges), road and personal safety, availability and accessibility of places to be active, destinations, and aesthetics. Interviews were recorded, transcribed verbatim and analysed using a content-thematic approach using QSR NVivo software. While some urban environmental constructs were salient to these rural adults, such as availability of and accessibility to places to be active, some constructs were operationalised differently, such as road safety (where large trucks and winding roads rather than traffic density was of concern), or were not considered relevant (eg, personal safety related to crime, availability of walkable destinations, aesthetics). The measurement of the physical environment in rural populations may require reconsideration and/or modification to ensure salience and appropriate quantification of associations with physical activity in future studies.

  13. A Qualitative Study of Environmental Factors Important for Physical Activity in Rural Adults.

    Directory of Open Access Journals (Sweden)

    Verity Cleland

    Full Text Available Despite increasing evidence that the physical environment impacts on physical activity among urban-dwellers, little attention has been devoted to understanding this relationship in rural populations. Work in this area is further hindered by a lack of environmental measures specifically designed for rural settings. This qualitative study aimed to explore the salience of urban physical activity environment constructs among rural adults.In 2011, 49 rural men and women from three distinct areas (coastal, animal-based farming, forestry/plant-based farming of rural Tasmania, Australia, were purposively recruited to participate in semi-structured interviews. Interviews explored features of the built and social environment commonly examined in studies of urban adults, including functional characteristics (eg, lighting, footpaths, roads/verges, road and personal safety, availability and accessibility of places to be active, destinations, and aesthetics. Interviews were recorded, transcribed verbatim and analysed using a content-thematic approach using QSR NVivo software.While some urban environmental constructs were salient to these rural adults, such as availability of and accessibility to places to be active, some constructs were operationalised differently, such as road safety (where large trucks and winding roads rather than traffic density was of concern, or were not considered relevant (eg, personal safety related to crime, availability of walkable destinations, aesthetics.The measurement of the physical environment in rural populations may require reconsideration and/or modification to ensure salience and appropriate quantification of associations with physical activity in future studies.

  14. The importance of supporting adolescents' autonomy in promoting physical-sport exercise.

    Science.gov (United States)

    Moreno-Murcia, Juan Antonio; Hernández, Elisa Huéscar

    2013-01-01

    This study was conducted toward the objective of analyzing certain factors that influence physical activity in Spanish adolescent students using self-determination theory (Deci & Ryan, 1985; 2000) as a framework. Participants included 698 physical education students whose perception of the autonomy support provided by their teachers was assessed in and out of the class context. Also assessed were social goals of responsibility and relationship with others, basic psychological needs, and intrinsic motivation, which is part of self-determination theory (SDT). Finally, the "intention" factor posited by the theory of planned behavior (TPB) and students' rate of exercise in the last twelve months were considered. The results of structural equations modeling suggest autonomy education, autonomy support, and social goals positively predicted certain psychological mediators, which in turn positively predicted students' intrinsic motivation, which was a positive predictor of intention, and that of rate of exercise. The results also highlight the benefit of promoting autonomy to enhance students' physical exercise practice.

  15. Importance of a balanced diet on the physical fitness level of schoolchildren aged 6-12.

    Science.gov (United States)

    Chung, Louisa; Wong, Thomas; Chung, Joanne Wai Yee

    2010-09-01

    Previous studies have focused on a single nutrient's relationship with disease and thus are unable to strongly support the health claims of a balanced diet. This article explores the integrated effect of nine nutrients on an individual's physical fitness level. Two-day dietary records and physical fitness assessments were collected in three primary schools. Cluster analysis allowed compliance with nutrient recommendations to be compared among groups of primary school students with different characteristics. Two clusters were identified statistically. Cluster B, which comprised more schoolchildren at the 'Good' and 'Pass' levels and fewer at the 'Excellent' level, had significantly more participants who met the guidelines for total fat, saturated fat, sodium and cholesterol, compared with Cluster A. This finding reveals the benefits of a balanced diet, with physical fitness level as the outcome measure. The results also have implications for approaching health problems from the diet-fitness perspective rather than the obesity-disease perspective.

  16. Pre-physical treatment: an important procedure to improve spectral resolution in polymers microstructure studies using 13C solution NMR

    International Nuclear Information System (INIS)

    Pedroza, Oscar J.O.; Tavares, Maria I.B.

    2004-01-01

    Changes in physical properties of polymeric materials can be evaluated from their microstructures, which can be investigated using solution carbon-13 nuclear magnetic resonance (NMR). In this type of study spectral resolution is very important, which obviously depend on the sample and solvent. A pre physical treatment allows for an improvement in the spectral resolution. Consequently, more information on chain linking can be obtained, thus facilitating the determination of the stereo sequences. (author)

  17. The importance of the discovery of the neutron by J. Chadwick to the development of nuclear physics and technology

    International Nuclear Information System (INIS)

    Seeliger, D.

    1983-01-01

    The discovery of the neutron by J. Chadwick in 1932 was a milestone in the development of nuclear physics and technology. Apart from basic findings on the structure of atomic nuclei, this discovery has found various fields of application among which nuclear power technology is the most important. The relation between historical impact and topicality of certain objects of investigation in neutron physics is outlined on the basis of some lines of development. (author)

  18. THE IMPORTANCE OF PHYSICAL ABILITY AND TECHNICAL PREPARATION FOR THE GROWTH OF YOUNG FOOTBALLERS

    Directory of Open Access Journals (Sweden)

    Niko Raičković

    2006-06-01

    Full Text Available Physical preparation of young footballers significantly difers from that of adult footballers. Young footballers,while growing and maturing,go through sensitive phases,namely periods, when it is the most convenient to influence on the development of certain characteristics and abilities. Physical abilities include motor and functional abilities. Motor abilities are:strength, speed, endurance, elacticity and coordination. Functional abilities include aerobic and anaerobic organism capacity. Football technique is the basic instrument of organising the football game. Technique has individual character. Technical preparation mainly covers training and improvement of basic football game techniques, namely, moving with and without ball and bringing technique to perfection

  19. 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...

  20. Greek pre-service physical education teachers’ beliefs about curricular orientations: Instrument validation and examination of four important goals

    Directory of Open Access Journals (Sweden)

    Manolis Adamakis

    2013-12-01

    Full Text Available BACKGROUND: The way people interpret reality is influenced by their mental constructions, their cognitive abilities and their beliefs. Physical Education (PE students have a wide range of formed beliefs concerning the purposes of PE, which cannot be easily modified, even during undergraduate studies. OBJECTIVE: This study validated the scores from a previously constructed questionnaire and investigated the Physical Education students’ belief systems toward the Greek curricular outcome goals. METHODS: Students (N = 483; males = 259, females = 224 from a Greek Faculty of Physical Education and Sport Science shared their beliefs about curricular outcomes. They completed the Greek version of the four factor instrument “Attitudes/beliefs toward curriculum in physical education”. A confirmatory factor analysis was conducted for the validation of the instrument and MANOVAs followed in order to control for group differences. Finally, a profile analysis was run in order to determine if PE students considered each goal to be equally important. RESULTS: The validation of the instrument confirmed the proposed four factors dependant model. Both internal consistency and the confirmatory factor analysis fit indices produced valid and reliable scores. The profile analysis was significant, indicating that students did not view the outcome goals as equally important. The leading goal was physical activity and fitness, followed by self-actualization, social development and motor skill development. MANOVA results for comparisons between sub-groups revealed significant differences only between genders. CONCLUSIONS: Between groups similarities and differences are discussed, focusing on the classification of the four important outcome goals. Currently, Greek Physical Education students consider physical activity and fitness outcome goal as the most important, while motor skill development is considered the least important one.

  1. Fear of Movement and Low Self-Efficacy Are Important Barriers in Physical Activity after Renal Transplantation.

    Science.gov (United States)

    Zelle, Dorien M; Corpeleijn, Eva; Klaassen, Gerald; Schutte, Elise; Navis, Gerjan; Bakker, Stephan J L

    2016-01-01

    Physical activity (PA) and exercise are commonly used as preventive measures for cardiovascular disease in the general population, and could be effective in the management of post-transplantation cardiovascular risk. PA levels are low after renal transplantation and very few renal transplant recipients (RTR) meet the PA guidelines. Identification of barriers to regular PA is important to identify targets for intervention to improve PA levels after renal transplantation. We investigated fear of movement and physical self-efficacy as barriers to PA in RTR. RTR were investigated between 2001-2003. The Tampa Score of Kinesiophobia-Dutch Version (TSK-11) was used to assess fear of movement. Physical self-efficacy was measured with the LIVAS-scale. PA was assessed using validated questionnaires (Tecumseh Occupational Activity Questionnaire and the Minnesota Leisure Time Physical Activity Questionnaire). A total of 487 RTR (age 51±12 years, 55% men) were studied. Median score [interquartile range] on TSK-11 was 22 [17-26]. Low physical self-efficacy (Exp B:0.41[0.31-0.54], pphysical self-efficacy. This study was the first to examine fear of movement and self-efficacy in relation to PA in RTR. Fear of movement was associated with a low PA level, and the larger part of this relation was mediated by low physical self-efficacy. Both fear of movement and physical self-efficacy level are important targets for intervention during rehabilitation after renal transplantation.

  2. Cofactors in allergic reactions to food : physical exercise and alcohol are the most important

    NARCIS (Netherlands)

    Versluis, Astrid; van Os-Medendorp, Harmieke; Kruizinga, Astrid G; Blom, W Marty; Houben, Geert F; Knulst, André C

    2016-01-01

    INTRODUCTION: Involvement of cofactors, like physical exercise, alcohol consumption and use of several types of medication, are associated with more severe food allergic symptoms. However, there is limited evidence on how often cofactors play a role in food allergic reactions. The study aimed to get

  3. The importance of physical activity and sleep for affect on stressful days: Two intensive longitudinal studies.

    Science.gov (United States)

    Flueckiger, Lavinia; Lieb, Roselind; Meyer, Andrea H; Witthauer, Cornelia; Mata, Jutta

    2016-06-01

    We investigated the potential stress-buffering effect of 3 health behaviors-physical activity, sleep quality, and snacking-on affect in the context of everyday life in young adults. In 2 intensive longitudinal studies with up to 65 assessment days over an entire academic year, students (Study 1, N = 292; Study 2, N = 304) reported stress intensity, sleep quality, physical activity, snacking, and positive and negative affect. Data were analyzed using multilevel regression analyses. Stress and positive affect were negatively associated; stress and negative affect were positively associated. The more physically active than usual a person was on a given day, the weaker the association between stress and positive affect (Study 1) and negative affect (Studies 1 and 2). The better than usual a person's sleep quality had been during the previous night, the weaker the association between stress and positive affect (Studies 1 and 2) and negative affect (Study 2). The association between daily stress and positive or negative affect did not differ as a function of daily snacking (Studies 1 and 2). On stressful days, increasing physical activity or ensuring high sleep quality may buffer adverse effects of stress on affect in young adults. These findings suggest potential targets for health-promotion and stress-prevention programs, which could help reduce the negative impact of stress in young adults. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  4. Physical Activity Based Professional Development for Teachers: The Importance of Whole School Involvement

    Science.gov (United States)

    Till, Jude; Ferkins, Lesley; Handcock, Phil

    2011-01-01

    Objective: This study sought to investigate teachers' perceptions of a physical activity-related professional development intervention. Design: Interview-based qualitative approach founded on the interpretive paradigm. Setting: Purposive selection of one high-rated independent, and one low-rated public primary school from Auckland, New Zealand.…

  5. THE ROLE AND IMPORTANCE OF THEORETICAL PREPARATION ON “PHYSICAL EDUCATION FOR HIGHSCHOOL STUDENTS

    Directory of Open Access Journals (Sweden)

    DANIEL DOCU AXELERAD

    2009-12-01

    Full Text Available According to the pre-universitary curriculum, one of the criteria to asses the level of the subject’s acquisition is the quality of the theoretical knowledge. In the basic organizing documents of school physical education, there were and still are stipulated the exact requests regarding the necessary theoretical knowledge ofstudents on various education levels. According to these documents, the theoretical knowledge was general knowledge. To the general knowledge, there are added those pertaining to the basic information of the given subject, information about the means and methods of physical education, information from the domain of prophylactic physical education, etc. Special knowledge is that representing the students’ knowledge form various sports tests provided by the school curriculum, such as the sporting games (volleyball, basketball,football, handball, athletics (running, jumping, throwing and gymnastics (apparatus and floor exercises. It is here that the means and methods applied in acquiring the compartments listed above are attributed. In the special knowledge category there is also the knowledge related to the means, the forms and the methods to develop the basic motor qualities (force, speed, flexibility, resistance, skills, as well as the procedures for evaluating them.Nevertheless, regardless of the fact that in the physical education organizing normative documents, highschool included, it is provided that theoretical knowledge should be acquired, still there is no actual presentation of the specific requirements and the assessment criteria for the level of acquisition. No document specifies the ways to evaluate the volume and quality of acquiring the theoretical knowledge, which is why we are going to present here a detailed analysis of the level of acquisition of theoretical knowledge for the “Physical Education” subject by highschool students after applying the teaching –learning -evaluation technique on the

  6. The Importance of Vigorous-Intensity Leisure-Time Physical Activity in Reducing Cardiovascular Disease Mortality Risk in the Obese.

    Science.gov (United States)

    O'Donovan, Gary; Stamatakis, Emmanuel; Stensel, David J; Hamer, Mark

    2018-03-02

    To investigate the role of vigorous-intensity leisure-time physical activity in reducing cardiovascular disease (CVD) mortality risk in the obese. Trained interviewers assessed physical activity and body mass index (BMI; calculated as the weight in kilograms divided by the height in meters squared) in 59,005 adult participants (mean ± SD age, 57±12 years; 46.5% male) in 2 household-based surveillance studies: Health Survey for England and Scottish Health Survey. Mortality was ascertained from death certificates. Data were collected from January 1, 1994, through March 31, 2011. Cox proportional hazards models were adjusted for age, sex, smoking habit, total physical activity, long-standing illness, prevalent CVD, and occupation. There were 2302 CVD deaths during 532,251 person-years of follow-up (mean ± SD, 9±4 years). A total of 15,002 (25%) participants were categorized as obese (BMI ≥30). Leisure-time physical activity was inversely associated and BMI was positively associated with CVD mortality. Compared with those who reported meeting physical activity guidelines including some vigorous-intensity physical activity and who had a normal BMI (18.5-24.9) (reference group), the CVD mortality hazard ratio was not significantly different in the obese who also reported meeting physical activity guidelines including some vigorous-intensity physical activities (1.25; 95% CI, 0.50-3.12). Compared with the reference group, the CVD mortality hazard ratio was more than 2-fold in the obese who reported meeting physical activity guidelines, including only moderate-intensity physical activities (2.52; 95% CI, 1.15-2.53). This large, statistically powerful study suggests that vigorous-intensity leisure-time physical activity is important in reducing CVD mortality risk in the obese. Copyright © 2018 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  7. A spatio-temporal evaluation of the WRF physical parameterisations for numerical rainfall simulation in semi-humid and semi-arid catchments of Northern China

    Science.gov (United States)

    Tian, Jiyang; Liu, Jia; Wang, Jianhua; Li, Chuanzhe; Yu, Fuliang; Chu, Zhigang

    2017-07-01

    Mesoscale Numerical Weather Prediction systems can provide rainfall products at high resolutions in space and time, playing an increasingly more important role in water management and flood forecasting. The Weather Research and Forecasting (WRF) model is one of the most popular mesoscale systems and has been extensively used in research and practice. However, for hydrologists, an unsolved question must be addressed before each model application in a different target area. That is, how are the most appropriate combinations of physical parameterisations from the vast WRF library selected to provide the best downscaled rainfall? In this study, the WRF model was applied with 12 designed parameterisation schemes with different combinations of physical parameterisations, including microphysics, radiation, planetary boundary layer (PBL), land-surface model (LSM) and cumulus parameterisations. The selected study areas are two semi-humid and semi-arid catchments located in the Daqinghe River basin, Northern China. The performance of WRF with different parameterisation schemes is tested for simulating eight typical 24-h storm events with different evenness in space and time. In addition to the cumulative rainfall amount, the spatial and temporal patterns of the simulated rainfall are evaluated based on a two-dimensional composed verification statistic. Among the 12 parameterisation schemes, Scheme 4 outperforms the other schemes with the best average performance in simulating rainfall totals and temporal patterns; in contrast, Scheme 6 is generally a good choice for simulations of spatial rainfall distributions. Regarding the individual parameterisations, Single-Moment 6 (WSM6), Yonsei University (YSU), Kain-Fritsch (KF) and Grell-Devenyi (GD) are better choices for microphysics, planetary boundary layers (PBL) and cumulus parameterisations, respectively, in the study area. These findings provide helpful information for WRF rainfall downscaling in semi-humid and semi

  8. Physical Dating Violence in Spain and the United Kingdom and the Importance of Relationship Quality.

    Science.gov (United States)

    Viejo, C; Monks, C P; Sánchez, V; Ortega-Ruiz, R

    2016-05-01

    Mixed-gender friendships, romantic relationships, and sexual behaviors increase during adolescence as a normal part of development. However, some studies have revealed potential risks to these types of social relationships. Different authors have indicated that dating violence among adolescents is an issue for concern. To date, there has been little research on this topic cross-nationally. This study examined and compared the prevalence and characteristics of physical dating violence among young people aged between 15 and 18 years in England and Spain (N = 200 in Spain, N = 199 in England), and how being involved (or not) in this violence relates to romantic relationship quality. Results indicated that approximately 23% of young people reported victimization and 30% reported perpetrating physical dating violence. In both countries, most of those involved in physical dating violence reported involvement in reciprocal violence (displaying both aggression and victimization). Those young people involved in dating violence reported higher levels on scales assessing negative aspects of relationship quality compared with those not involved, but there were no significant differences in positive aspects of relationship quality. Furthermore, different patterns appeared relating to the severity of violence and country. The findings are discussed in terms of their implications for theory and practice. © The Author(s) 2015.

  9. Functional Exercise and Physical Fitness Post Stroke: The Importance of Exercise Maintenance for Motor Control and Physical Fitness after Stroke

    Directory of Open Access Journals (Sweden)

    Birgitta Langhammer

    2012-01-01

    Full Text Available It is argued that all stroke patients, indifferent of disability, have the same possibility to improve with training. The aim of the study was to follow and register functional improvements in two groups with different functional capacities at baseline for a period of 36 months. Stroke patients were recruited and divided into groups related to their functional status at baseline. During the acute rehabilitation, both groups received functional task-oriented training, followed by regular self- or therapeutic driven training the first year after stroke and varied exercise patterns the following 24 months. The participants were tested on admission, and at three, six, twelve, and thirty-six months after the onset of stroke. Both groups improved functional activity up to six months which then stabilized up to twelve months to decline somewhat at thirty-six months after stroke. Change scores indicate a greater potential for rehabilitation in the MAS ≤35 in relation to group MAS >35 although the functional capacity was higher in the latter. This indicates the importance of maintaining exercise and training for all persons after stroke.

  10. Complex transfers in porous media: some physical and numerical approaches; Transferts complexes en milieux poreux: quelques approches physiques et numeriques

    Energy Technology Data Exchange (ETDEWEB)

    Maugis, P

    2006-06-15

    The feasibility and safety of nuclear waste storage containers is studied. The thermodynamics of water/air flow is described and applied, via a simplified numerical model, to a simple experimental apparatus yielding heat pipe effect. The 2D influence of deterministic boundary conditions is important on kinematics and transport. Dispersivity depends on the nonuniform flow type and integrates the often marginal Gaussian part of plume spreading. A new algorithm, based on jump locality and recalibration, avoids the small bias induced by inter-cell diffusive jumps. Several algorithms modeling transport of decaying, soluble, sorbing, or precipitating species are compared. Stability and precision criteria are analyzed. Up-stream over-precipitation and negative down-stream concentrations are observed for high solubility contrasts. (author)

  11. Is a perceived supportive physical environment important for self-reported leisure time physical activity among socioeconomically disadvantaged women with poor psychosocial characteristics? An observational study.

    Science.gov (United States)

    Cleland, Verity J; Ball, Kylie; Crawford, David

    2013-03-27

    Over the past decade, studies and public health interventions that target the physical environment as an avenue for promoting physical activity have increased in number. While it appears that a supportive physical environment has a role to play in promoting physical activity, social-ecological models emphasise the importance of considering other multiple levels of influence on behaviour, including individual (e.g. self-efficacy, intentions, enjoyment) and social (e.g. social support, access to childcare) factors (psychosocial factors). However, not everyone has these physical activity-promoting psychosocial characteristics; it remains unclear what contribution the environment makes to physical activity among these groups. This study aimed to examine the association between the perceived physical environment and self-reported leisure-time physical activity (LTPA) among women living in socioeconomically disadvantaged areas demonstrating different psychosocial characteristics. In 2007-8, 3765 women (18-45 years) randomly selected from low socioeconomic areas in Victoria, Australia, self-reported LTPA, and individual, social and physical environmental factors hypothesised within a social-ecological framework to influence LTPA. Psychosocial and environment scores were created. Associations between environment scores and categories of LTPA (overall and stratified by thirds of perceived environment scores) were examined using generalised ordered logistic regression. Women with medium and high perceived environment scores had 20-38% and 44-70% greater odds respectively of achieving higher levels of LTPA than women with low environment scores. When stratified by thirds of psychosocial factor scores, these associations were largely attenuated and mostly became non-significant. However, women with the lowest psychosocial scores but medium or high environment scores had 76% and 58% higher odds respectively of achieving ≥120 minutes/week (vs. <120 minutes/week) LTPA

  12. Investigation of the physical and numerical foundations of two-fluid representation of sodium boiling with applications to LMFBR experiments

    International Nuclear Information System (INIS)

    No, H.C.; Kazimi, M.S.

    1983-03-01

    This work involves the development of physical models for the constitutive relations of a two-fluid, three-dimensional sodium boiling code, THERMIT-6S. The code is equipped with a fluid conduction model, a fuel pin model, and a subassembly wall model suitable for stimulating LMFBR transient events. Mathematically rigorous derivations of time-volume averaged conservation equations are used to establish the differential equations of THERMIT-6S. These equations are then discretized in a manner identical to the original THERMIT code. A virtual mass term is incorporated in THERMIT-6S to solve the ill-posed problem. Based on a simplified flow regime, namely cocurrent annular flow, constitutive relations for two-phase flow of sodium are derived. The wall heat transfer coefficient is based on momentum-heat transfer analogy and a logarithmic law for liquid film velocity distribution. A broad literature review is given for two-phase friction factors. It is concluded that entrainment can account for some of the discrepancies in the literature. Mass and energy exchanges are modelled by generalization of the turbulent flux concept. Interfacial drag coefficients are derived for annular flows with entrainment. Code assessment is performed by simulating three experiments for low flow-high power accidents and one experiment for low flow/low power accidents in the LMFBR. While the numerical results for pre-dryout are in good agreement with the data, those for post-dryout reveal the need for improvement of the physical models. The benefits of two-dimensional non-equilibrium representation of sodium boiling are studied

  13. Fear of Movement and Low Self-Efficacy Are Important Barriers in Physical Activity after Renal Transplantation.

    Directory of Open Access Journals (Sweden)

    Dorien M Zelle

    Full Text Available Physical activity (PA and exercise are commonly used as preventive measures for cardiovascular disease in the general population, and could be effective in the management of post-transplantation cardiovascular risk. PA levels are low after renal transplantation and very few renal transplant recipients (RTR meet the PA guidelines. Identification of barriers to regular PA is important to identify targets for intervention to improve PA levels after renal transplantation. We investigated fear of movement and physical self-efficacy as barriers to PA in RTR.RTR were investigated between 2001-2003. The Tampa Score of Kinesiophobia-Dutch Version (TSK-11 was used to assess fear of movement. Physical self-efficacy was measured with the LIVAS-scale. PA was assessed using validated questionnaires (Tecumseh Occupational Activity Questionnaire and the Minnesota Leisure Time Physical Activity Questionnaire.A total of 487 RTR (age 51±12 years, 55% men were studied. Median score [interquartile range] on TSK-11 was 22 [17-26]. Low physical self-efficacy (Exp B:0.41[0.31-0.54], p<0.001 and history of myocardial infarction, transient ischemic attack and cerebrovascular accident (Exp B:1.30[1.03-1.63],p = 0.03 were independent determinants for fear of movement. Fear of movement was associated with lower daily PA, occupational, sports and leisure time PA. Mediation-analysis showed that a large part (73% of the effect of fear of movement on PA was explained by low physical self-efficacy.This study was the first to examine fear of movement and self-efficacy in relation to PA in RTR. Fear of movement was associated with a low PA level, and the larger part of this relation was mediated by low physical self-efficacy. Both fear of movement and physical self-efficacy level are important targets for intervention during rehabilitation after renal transplantation.

  14. Missing transverse energy measurement in ATLAS detector: first LHC data results and importance for physics study

    CERN Document Server

    Pizio, Caterina

    2010-01-01

    The Large Hadron Collider (LHC) at CERN started its operation at the end of November 2009, first at a centre-of-mass energy of 900 GeV, then, since March 2010, at 7 TeV. During this period the ATLAS experiment has collected a large number of proton-proton collision events, resulting up to now in an integrated luminosity of about 45 pb-1. A very good measurement of the missing transverse energy, ETmiss, is essential for many physics studies in ATLAS both for Standard Model channels, as W, Z bosons decaying to tau leptons or top quark decays, and for discovering channels. Events with large ETmiss are expected to be the key signature for new physics such as supersymmetry and extra dimensions. A good ETmiss measurement in terms of linearity and resolution is crucial for the efficient and accurate reconstruction of the Higgs boson mass when the Higgs boson decays to a pair of tau leptons. This thesis describes the first measurement of ETmiss in ATLAS with real data. The performance of the algorithm for ETmiss reco...

  15. Cognitive and physical resources are important in order to complete a geriatric fall prevention programme.

    Science.gov (United States)

    Kirchhoff, Marianne; Damgaard, Kirsten

    2016-01-01

    It is well documented that falls may be prevented, but effectiveness in reducing the risk of falling depends on the uptake of and the adherence to preventive actions. 65+-year-old fallers identified by screening for fall risk were offered referral to a geriatric fall clinic together with fallers referred from general practitioners (GPs). They were assessed to identify individual risk factors for falling, and appropriate interventions were planned, including exercise classes. A total of 811 persons were identified by screening, 342 of whom accepted referral. Furthermore, 176 were referred from GPs. Only 402 of 518 fallers attended the clinic. A total of 65 dropped out by their own request, 29 stopped because they became seriously ill or died. Another 62 patients were discharged before fulfilling the programme as they were unable to participate due to physical or cognitive problems. Indicators of cessation were cognitive or physical weakness. Geriatric fall prevention is resource-consuming both in terms of staff needed and with respect to demands made on the patients, and the frailest part of the fall population cannot comply. It is necessary to differentiate fall prevention services for the population of elderly fallers as interventions in primary healthcare have been shown to be more effective among the most frail elderly fallers. The project received funding from the Danish Ministry of the Interior and Health and from The Fund for Scientific Work in the Geriatric Field within the former Copenhagen Hospital Corporation. not relevant.

  16. The Physical Clogging of the Landfill Leachate Collection System in China: Based on Filtration Test and Numerical Modelling

    Directory of Open Access Journals (Sweden)

    Yili Liu

    2018-02-01

    Full Text Available Clogging of the leachate collection system (LCS has been a common operation problem in municipal solid waste (MSW landfills in China, which can result in high water levels that threaten the safety of landfill operations. To determine the cause of failure in an LCS, raw leachate from a municipal solid waste transfer station was collected and the high content of particulate matter was characterized. Based on the parameters obtained in a filtration test, a numerical simulation was performed to estimate the influence of particle deposition on drainage system clogging. The results showed that LCSs were confronted with the risk of clogging due to the deposition of particulate matter resulting from the higher concentration of total suspended solids (TSS level > 2200 mg L−1 and larger particle size (>30% TSS particles > 15 μm in the leachate. On one hand, the non-woven geotextile, as the upper layer of the LCS, retained most particulate matter of large diameters, reducing its hydraulic conductivity to approximately 10−8 to 10−9 m s−1 after 1–2 years of operation and perching significant leachate above it (0.6–0.7 m. On the other hand, the geotextile prevented the gravel layer from physically clogging and minimized the leachate head above the bottom liner. Therefore, the role of geotextile should be balanced to optimize the LCS in MSW landfills in China.

  17. Physical Simulation of a Duplex Stainless Steel Friction Stir Welding by the Numerical and Experimental Analysis of Hot Torsion Tests

    Science.gov (United States)

    da Fonseca, Eduardo Bertoni; Santos, Tiago Felipe Abreu; Button, Sergio Tonini; Ramirez, Antonio Jose

    2016-09-01

    Physical simulation of friction stir welding (FSW) by means of hot torsion tests was performed on UNS S32205 duplex stainless steel. A thermomechanical simulator Gleeble 3800® with a custom-built liquid nitrogen cooling system was employed to reproduce the thermal cycle measured during FSW and carry out the torsion tests. Microstructures were compared by means of light optical microscopy and electron backscatter diffraction. True strain and strain rate were calculated by numerical simulation of the torsion tests. Thermomechanically affected zone (TMAZ) was reproduced at peak temperature of 1303 K (1030 °C), rotational speeds of 52.4 rad s-1 (500 rpm) and 74.5 rad s-1 (750 rpm), and 0.5 to 0.75 revolutions, which represent strain rate between 10 and 16 s-1 and true strain between 0.5 and 0.8. Strong grain refinement, similar to the one observed in the stir zone (SZ), was attained at peak temperature of 1403 K (1130 °C), rotational speed of 74.5 rad s-1 (750 rpm), and 1.2 revolution, which represent strain rate of 19 s-1 and true strain of 1.3. Continuous dynamic recrystallization in ferrite and dynamic recrystallization in austenite were observed in the TMAZ simulation. At higher temperature, dynamic recovery of austenite was also observed.

  18. A numerical analysis of biogeochemical controls with physical modulation on hypoxia during summer in the Pearl River estuary

    Directory of Open Access Journals (Sweden)

    B. Wang

    2017-06-01

    Full Text Available A three-dimensional (3-D physical–biogeochemical coupled model was applied to explore the mechanisms controlling the dissolved oxygen (DO dynamics and bottom hypoxia during summer in the Pearl River estuary (PRE. By using the numerical oxygen tracers, we proposed a new method (namely the physical modulation method to quantify the contributions of boundary conditions and each source and sink process occurring in local and adjacent waters to the DO conditions. A mass balance analysis of DO based on the physical modulation method indicated that the DO conditions at the bottom layer were mainly controlled by the source and sink processes, among which the sediment oxygen demand (SOD at the water–sediment interface and the re-aeration at the air–sea interface were the two primary processes determining the spatial extent and duration of bottom hypoxia in the PRE. The SOD could cause a significant decrease in the bottom DO concentrations (averaged over July–August 2006 by over 4 mg L−1 on the shelf off the Modaomen sub-estuary, leading to the formation of a high-frequency zone of hypoxia (HFZ. However, the hypoxia that occurred in the HFZ was intermittent and distributed in a small area due to the combined effects of re-aeration and photosynthesis, which behaved as sources for DO and offset a portion of the DO consumed by SOD. The bottom DO concentrations to the west of the lower Lingdingyang Bay (i.e. the western shoal near Qi'ao Island were also largely affected by high SOD, but there was no hypoxia occurring there because of the influence of re-aeration. Specifically, re-aeration could lead to an increase in the bottom DO concentrations by ∼ 4.8 mg L−1 to the west of the lower Lingdingyang Bay. The re-aeration led to a strong vertical DO gradient between the surface and the lower layers. As a result, the majority (∼ 89 % of DO supplemented by re-aeration was transported to the lower layers through vertical diffusion and

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

    International Nuclear Information System (INIS)

    Mishchenko, V.

    2002-01-01

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

  20. Some important aspects of the amplitude, charge and shape analog signals digitization in nuclear physics experiment

    International Nuclear Information System (INIS)

    Kulka, Z.

    1995-01-01

    One of the fundamental reasons of the special requirements concerning analog-to-digital converters (ADC's) used in nuclear experimental physics, especially in nuclear spectroscopy, in comparison to the conventional ADC's is a fact that they are utilized for continuous distribution measurements which are the nuclear radiation spectra. The ADC's used for distribution registration in form of amplitude or charge histogram spectra should have the differential linearity of two orders of magnitude better than that for conventional ADC's. Moreover, the problem of achievement the acceptable differential linearity (as well as stability) in nuclear spectroscopy is much more complicated because high resolution and high speed of the converters are also required. The first requirement comes out from application of semiconductor detectors, the second one comes from the statistical character of the nuclear processes, as well as, a necessity of collection of huge amount of nuclear data - often in a short time. In this report the influence of the specific needs of the nuclear experiments on the conversion methods selection and construction principles of the pulse ADC's is analyzed. Focus is taken on these ADC's which are used mainly to digital amplitude and charge detector signals measurements in nuclear spectroscopy. Based on the chosen examples of different types of ADC's it is shown how to obtain the required metrological parameters by using enlarged converter's structures and proper choice of the electronics components. In addition, a problem of the detector signals shape measurements in particle physics using the high speed flash ADC's is also discussed. (author). 196 refs, 99 figs, 7 tabs

  1. HABITS OF PATIENTS AND IMPORTANCE OF PHYSICAL EDUCATOR IN THE TREATMENT OF DIABETES MELLITUS TYPE II IN PALMAS, TOCANTINS, BRAZIL

    Directory of Open Access Journals (Sweden)

    Maynard Noleto SALES

    2015-12-01

    Full Text Available Diabetes mellitus, a non-communicable disease that can affect men and women, can be classified as type I or type II. This disease is in the 4th position in numbers of deaths in Brazil, and therefore, involves attention, both from the government, as the patients and family. The aims of this study is describe the lifestyle in relation to diet, foot care and proper medication, and the point of view of patients with diabetes mellitus type II, on the importance of the practice of physical exercise, coordinated and programmed. We performed a study using Questionnaire of Self-Care Activities with Diabetes (QAD and a second questionnaire with questions related to the importance of exercise for patients with diabetes mellitus type II. Questionnaires were applied in 20 patients with the disease (08 men and 12 women, living in the city of Palmas, Tocantins, Brazil. Result: We noticed that even with the recommendations of healthcare professionals, most patients with diabetes mellitus type 2 has not adapted verification of blood glucose, proper nutrition and foot care. Moreover, despite the interviewees know the importance of performing regular physical activity, we noticed that these do not know how much of weekly days in which they must get physical exercise in order to control the disease. Most interviewees adopt just walk as the physical activity, and we have not verified from the answers of patients, if they know what the most beneficial exercises to control this disease.

  2. Atomic and molecular physics, physicochemical properties of biologically important structure, and high-voltage research

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Allen, J.D.; Anderson, V.E.

    1976-01-01

    Research in atomic and molecular physics is reported. Studies included: experimental evidence for the existence of a Ramsauer-Townsend minimum in liquid methane and liquid argon; discovery of a Ramsauer-Townsend minimum in gaseous ethane and propane; motion of thermal electrons in n-alkane vapors; electron mobilities in high pressure gases; electron capture and drift in liquid media; electron attachment to molecules in dense gases; attachment of slow electrons to hexafluorobenzene; fragmentation of atmospheric halocarbons under electron impact; negative ion resonances and threshold electron excitation spectra of organic molecules; theoretical studies of negative-ion resonance states of organic molecules; kinetics of electron capture by sulfur hexafluoride in solution; interactions of slow electrons with benzene and benzene derivatives; Stokes and anti-Stokes fluorescence of 1 : 12-benzoperylene in solution; photoionization of molecules in liquid media; construction of high-voltage breakdown apparatus for gaseous insulation studies; measurements of the breakdown strengths of gaseous insulators and their relation to basic electron-collision processes; accuracy of the breakdown voltage measurements; and assembling basic data on electronegative gases of significance to breakdown

  3. Childhood Maltreatment and the Development of Relational and Physical Aggression: The Importance of a Gender-Informed Approach

    Science.gov (United States)

    Cullerton-Sen, Crystal; Cassidy, Adam R.; Murray-Close, Dianna; Cicchetti, Dante; Crick, Nicki R.; Rogosch, Fred A.

    2012-01-01

    This investigation examined the associations between maltreatment and aggression using a gender-informed approach. Peer ratings, peer nominations, and counselor reports of aggression were collected on 211 maltreated and 199 non-maltreated inner-city youth (mean age = 9.9 years) during a summer day camp. Maltreatment was associated with aggressive conduct; however, these effects were qualified by gender, maltreatment subtype, and the form of aggression under investigation. Findings revealed that maltreatment was associated with physical aggression for boys and relational aggression for girls. Physical abuse was associated with physically aggressive behaviors, but sexual abuse predicted relational aggression for girls only. Findings suggest that investigating the interaction between familial risk and gender is important in understanding aggressive behaviors of boys and girls. PMID:19037946

  4. Importance sampling implemented in the code PRIZMA for deep penetration and detection problems in reactor physics

    International Nuclear Information System (INIS)

    Kandiev, Y.Z.; Zatsepin, O.V.

    2013-01-01

    At RFNC-VNIITF, the PRIZMA code which has been developed for more than 30 years, is used to model radiation transport by the Monte Carlo method. The code implements individual and coupled tracking of neutrons, photons, electrons, positrons and ions in one dimensional (1D), 2D or 3D geometry. Attendance estimators are used for tallying, i.e., the estimators whose scores are only nonzero from particles which cross a region or surface of interest. Importance sampling is used to make deep penetration and detection calculations more effective. However, its application to reactor analysis appeared peculiar and required further development. The paper reviews methods used for deep penetration and detection calculations by PRIZMA. It describes in what these calculations differ when applied to reactor analysis and how we compute approximated importance functions and parameters for biased distributions. Methods to control the statistical weight of particles are also discussed. A number of test and applied calculations which were done for the purpose of verification are provided. They are shown to agree either with asymptotic solutions if exist, or with results of analog calculations or predictions by other codes. The applied calculations include the estimation of ex-core detector response from neutron sources arranged in the core, and the estimation of in-core detector response. (authors)

  5. Environmental physics

    CERN Document Server

    Smith, Clare

    2001-01-01

    Environmental Physics is a comprehensive introduction to the physical concepts underlying environmental science. The importance and relevance of physics is emphasised by its application to real environmental problems with a wide range of case studies. Applications included cover energy use and production, global climate, the physics of living things, radioactivity, environmental remote sensing, noise pollution and the physics of the Earth. The book makes the subject accessible to those with little physics background, keeping mathematical treatment straightforward. The text is lively and informative, and is supplemented by numerous illustrations, photos, tables of useful data, and a glossary of key terms.

  6. Physical and numerical modelling of permafrost dynamic during a climatic cycle: implications for Meuse - Haute-Marne site

    International Nuclear Information System (INIS)

    Regnier, D.

    2012-01-01

    This manuscript deals about works realized on the permafrost modelling in porous media and its impact on the hydrogeological circulations. These are parts of the Andra's studies on the nuclear waste storage and, on the environmental studies of the Meuse/Haute-Marne (MHM) site. During a climatic cycle, cold periods can generate permafrost (ground with temperature lower than 0 C for 2 consecutive years). This peri-glacial structure propagates towards deep geological layers, and, due to its very low permeability, can stop the flow of water bodies like aquifers. This work presents the elaboration of two numerical models (with Cast3M code (CEA)): (i) a model with thermal conduction, used for the study of a cold wave propagation in porous media with phase transition (water-ice); (ii) a more complex model, managing the thermo-hydraulic coupling of ground phenomenon (conduction, convection and transition of phase). After validation, these two models offer three axes of development: (i) benchmark proposition by the study of two generic test-cases; (ii) study of the local air temperature signal on MHM site: importance of high frequency temperature variations (centennial scale) for permafrost depth and stability; (iii) study of the dynamics of a thermal discontinuity in a typical hydrological system river-plain: closure time of the system by the permafrost according to various parameters (temperatures, geothermal flow, hydrological flow directions). (author) [fr

  7. Self-Perceptions of Sexual Attractiveness: Satisfaction With Physical Appearance is Not of Primary Importance Across Gender and Sexual Orientation.

    Science.gov (United States)

    Amos, Natalie; McCabe, Marita P

    2016-01-01

    Research on self-perceived sexual attractiveness has predominantly focused on the importance of physical appearance, overlooking nonphysical traits that may contribute to these self-perceptions. The present study examined and compared the importance of a variety of traits for self-perceived sexual attractiveness. Self-identified heterosexual, gay, and bisexual men (N = 1,801) and heterosexual, lesbian, and bisexual women (N = 1,092) completed an online questionnaire examining self-perceived sexual attractiveness, body esteem, sexual esteem, adherence to gender norms, and sexual experience. Body esteem and sexual esteem were significant predictors of self-perceived sexual attractiveness, regardless of gender and sexual orientation. Adhering to a masculine gender norm was a significant predictor among all groups (to varying extents) but heterosexual women. Adhering to a feminine gender norm was a significant predictor among heterosexual men and bisexual women. Finally, sexual experience was a significant predictor for all men and bisexual women. Furthermore, while body esteem was a predictor across all groups, for most individuals it did not appear to be of primary importance, with either sexual esteem or masculinity proving to be of greater importance. These findings suggest the need to consider traits related to both physical and nonphysical factors for improving an individual's self-perceived sexual attractiveness.

  8. A Cross-Sectional Investigation of the Importance of Park Features for Promoting Regular Physical Activity in Parks.

    Science.gov (United States)

    Costigan, Sarah A; Veitch, Jenny; Crawford, David; Carver, Alison; Timperio, Anna

    2017-11-02

    Parks in the US and Australia are generally underutilised, and park visitors typically engage in low levels of physical activity (PA). Better understanding park features that may encourage visitors to be active is important. This study examined the perceived importance of park features for encouraging park-based PA and examined differences by sex, age, parental-status and participation in PA. Cross-sectional surveys were completed by local residents ( n = 2775) living near two parks (2013/2015). Demographic variables, park visitation and leisure-time PA were self-reported, respondents rated the importance of 20 park features for encouraging park-based PA in the next fortnight. Chi-square tests of independence examined differences in importance of park features for PA among sub-groups of local residents (sex, age, parental-status, PA). Park features ranked most important for park-based PA were: well maintained (96.2%), feel safe (95.4%), relaxing atmosphere (91.2%), easy to get to (91.7%), and shady trees (90.3%). All subgroups ranked 'well maintained' as most important. Natural and built environment features of parks are important for promoting adults' park-based PA, and should be considered in park (re)design.

  9. Social support for youth physical activity: Importance of siblings, parents, friends and school support across a segmented school day

    Directory of Open Access Journals (Sweden)

    Kolt Gregory S

    2007-11-01

    Full Text Available Abstract Background Whilst evidence exists for the influence of encouragement on physical activity participation, the diversity of support sources and the type of physical activity examined previously is limited. This study examined the importance of perceived encouragement from parents, siblings/cousins, friends, and schools on participation levels across three time-specific activity opportunities that are available during a school day (after-school physical activities, lunchtime activity, and active transportation to and from school. Methods A cross-sectional sample of 12–18 year old high school students (n = 3,471 were recruited from low SES schools within South Auckland, New Zealand and categorised as either Junior (Years 9–11 or Senior (Years 12 & 13 students. Participants reported their physical activity levels and quantity of encouragement received from their parent(s, friend(s, sibling(s/cousin(s, and school to be active. For each physical activity variable participants were dichotomized as being either "active" or "less active". For each social support source, participants were grouped into either receiving "high" or "low" levels of support. Binary logistic regression analyzes were conducted to calculate odd ratios and 95% confidence intervals. Results Low parental support (Juniors, OR: 0.47, 95% CI: 0.38–0.58; Seniors, OR: 0.41, 95% CI: 0.29–0.60 and low peer support (Juniors, OR: 0.61, 95% CI: 0.51–0.74; Seniors, OR: 0.49, 95% CI: 0.35–0.69 were associated with reduced odds of being regularly active after school. For lunchtime activity, low peer support (Juniors, OR: 0.39, 95% CI: 0.32–0.48; Seniors, OR: 0.41, 95% CI: 0.29–0.57 was associated with reduced odds of being categorized as active. While no variables were significantly related to active transportation among senior students, low peer support was associated with reduced odds of actively commuting for Junior students (OR: 0.78, 95% CI: 0.66–0.92. Irrespective

  10. The role of exercise and gender for physical self-perceptions and importance ratings in Swedish university students.

    Science.gov (United States)

    Lindwall, Magnus; Hassmén, Peter

    2004-12-01

    The purpose of this study was to investigate how scores on the Physical Self-Perception Profile (PSPP), including scores on the Perceived Importance Profile (PIP), were related to self-reported exercise frequency, duration, and gender in sample of Swedish university students. A total of 164 participants completed the PSPP, PIP, and a questionnaire focusing on frequency and duration of exercise. Exercise frequency, duration, and gender predicted best the PSPP sub-domains of Sport Competence and Physical Conditioning. Exercising more frequently, and for a longer time on each occasion was associated with higher PSPP and PIP scores. Women generally displayed lower PSPP scores than men. These results suggest that exercise professionals need to master a range of appropriate exercise strategies, since doubts concerning self-presentation may work against establishing a regular exercise routine.

  11. Important contributions of M.C. Wang and C.S. Wang Chang to non-equilibrium statistical physics

    International Nuclear Information System (INIS)

    Liu Jixing

    2004-01-01

    In the middle of the 20th century two Chinese women physicists, Ming-Chen Wang and Cheng-Shu Wang Chang made great contributions to statistical physics. The famous review article 'On the theory of the Brownian motion II' by Ming-Chen Wang and G.E. Uhlenbeck published in Rev. of Mod. Phys. in 1945 provided a complete scientific classification of stochastic processes which is still adopted by the scientific community as the standard classification. The Wang-Chang-Uhlenbeck (WCU) equation proposed jointly by C.S. Wang-Chang and Uhlenbeck became the fundamental kinetic equation for the treatment of transport properties of multi-atomic gases with internal degrees of freedom in the physics literature. These important scientific contributions are analyzed and reviewed

  12. PHYSICS

    CERN Multimedia

    Guenther Dissertori

    The time period between the last CMS week and this June was one of intense activity with numerous get-together targeted at addressing specific issues on the road to data-taking. The two series of workshops, namely the “En route to discoveries” series and the “Vertical Integration” meetings continued.   The first meeting of the “En route to discoveries” sequence (end 2007) had covered the measurements of the Standard Model signals as necessary prerequisite to any claim of signals beyond the Standard Model. The second meeting took place during the Feb CMS week and concentrated on the commissioning of the Physics Objects, whereas the third occurred during the April Physics Week – and this time the theme was the strategy for key new physics signatures. Both of these workshops are summarized below. The vertical integration meetings also continued, with two DPG-physics get-togethers on jets and missing ET and on electrons and photons. ...

  13. Adopting and maintaining physical activity behaviours in people with severe mental illness: The importance of autonomous motivation.

    Science.gov (United States)

    Vancampfort, Davy; Stubbs, Brendon; Venigalla, Sumanth Kumar; Probst, Michel

    2015-12-01

    Physical activity can improve the health of people with serious mental illness (SMI) but many are inactive. Adopting theoretically-based research considering the motivational processes linked to the adoption and maintenance of an active lifestyle between different diagnostic groups of people with SMI can assist in understanding physical activity in this group. Within the Self-Determination Theory (SDT) and the Trans-Theoretical Model (TTM) (stages of change) frameworks, we investigated differences in motives for physical activity between different diagnostic groups. All participants completed the Behavioral Regulation in Exercise Questionnaire 2 (BREQ-2), the International Physical Activity Questionnaire (IPAQ) and the Patient-centered Assessment and Counseling for Exercise (PACE) questionnaire. Overall 294 persons with SMI (190♀) (43.6 ± 13.6 years) agreed to participate. People with affective disorders had higher levels of introjected regulations than people with schizophrenia. No significant differences were found for other motivational regulations. Moreover, no significant differences were found according to gender, setting and educational level. Multivariate analyses showed significantly higher levels of amotivation and external regulations and lower levels of identified and intrinsic regulations in the earlier stages of change. Strongest correlations with the IPAQ were found for motivational regulations towards walking. Our results suggest that in all people with SMI the level of identified and intrinsic motivation may play an important role in the adoption and maintenance of health promoting behaviours. The study provides a platform for future research to investigate the relationships between autonomy support, motivational regulations and physical and mental health variables within lifestyle interventions for this population. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. A Comparative Study on Physical Vulnerability of Urban Area against Natural Hazards: Importance of Health Promoting Approach in Civil Engineering

    Directory of Open Access Journals (Sweden)

    Mohsen Ahadnezhad Reveshty

    2014-07-01

    Full Text Available Background: Estimation of urban vulnerability to earthquakes can be considered as an Ill-structured problem in urban in both unplanned and planned ar-eas. Multi-criteria evaluation (MCE provides a way to integrate different spatial data layers in a geographic information system to create composite maps representing risk. We utilized MCE in a raster Geographic Information System (GIS to evaluate risk in vulnerable tissues of Tabriz, Iran zone. Methods: In this MCE physical risk factors and sub-factors were included and were weighted by experts. Afterward data entered to GIS and then the layers of the criteria were exported. The obtained results were entered to IDRISI and fuzzified. Ultimately the final map of physical vulnerability was outputted by overlaying order. Results: Vulnerable tissues are highly consistent to non-official areas. How-ever, the planned area which is called Valiasr is in low risky condition and this condition is desirable in crisis times. Here, we observe the preference of physical pre-planning operations. Conclusion: The links between urban planning and health are many and varied. Environmental, social and economic conditions in cities can have both positive and negative influences on human health and centre. Urban planning and related professions play an important role in shaping those conditions.

  15. The importance of integumentary knowledge and skill in physical therapist entry-level education: are they prepared for practice?

    Science.gov (United States)

    Gibbs, Karen A; Furney, Steven R

    2013-01-01

    Physical therapist practice is grounded in patient management principles encompassing all body systems and focuses on prevention, education, and functional outcomes. As such, management of the integumentary system crosses all practice settings, emphasizing the importance that basic integumentary content be adequately addressed during entry-level education. The purpose of this qualitative study was to compare the self-reported integumentary knowledge and skill of recent graduates to profession-determined expectations for education. Participants were 7 licensed physical therapists experienced in wound management. Semi-structured interview data were recorded, transcribed, and coded. A matrix compiling professional expectations for integumentary education was utilized to identify topics as absent, covered only briefly, or covered only during clinical rotations. Compression, vascular screening, infection, factors impacting healing, modalities, dressings, wound measurements, topicals, and sutures/staples were among the most commonly reported areas of deficiency. While integumentary care makes up a small percentage of physical therapy practice, it is a significant part of a comprehensively educated therapist. This study found participants did not perceive themselves to have received the minimum entry-level integumentary knowledge and skill deemed necessary by the profession. Study results are supported by current literature and demonstrate the need for integumentary curriculum review in entry-level programs.

  16. A Comparative Study on Physical Vulnerability of Urban Area against Natural Hazards: Importance of Health Promoting Approach in Civil Engineering.

    Science.gov (United States)

    Ahadnezhad Reveshty, Mohsen; Kamelifar, Mohammad Javad; Ranjbarnia, Behzad; Pashaiifar, Alireza

    2014-01-01

    Estimation of urban vulnerability to earthquakes can be consid-ered as an Ill-structured problem in urban in both unplanned and planned areas. Multi-criteria evaluation (MCE) provides a way to integrate different spatial data layers in a geographic information system to create composite maps representing risk. We utilized MCE in a raster Geographic Information System (GIS) to evaluate risk in vulnerable tissues of Tabriz, Iran zone. In this MCE physical risk factors and sub-factors were included and were weighted by experts. Afterward data entered to GIS and then the layers of the criteria were exported. The obtained results were entered to IDRISI and fuzzified. Ultimately the final map of physical vulnerability was outputted by overlaying order. Vulnerable tissues are highly consistent to non-official areas. However, the planned area which is called Valiasr is in low risky condition and this condition is desirable in crisis times. Here, we observe the preference of physical pre-planning operations. The links between urban planning and health are many and varied. Environmental, social and economic conditions in cities can have both positive and negative influences on human health and centre. Urban planning and related professions play an important role in shaping those conditions.

  17. Importance of physical and hydraulic characteristics to unionid mussels: A retrospective analysis in a reach of large river

    Science.gov (United States)

    Zigler, S.J.; Newton, T.J.; Steuer, J.J.; Bartsch, M.R.; Sauer, J.S.

    2008-01-01

    Interest in understanding physical and hydraulic factors that might drive distribution and abundance of freshwater mussels has been increasing due to their decline throughout North America. We assessed whether the spatial distribution of unionid mussels could be predicted from physical and hydraulic variables in a reach of the Upper Mississippi River. Classification and regression tree (CART) models were constructed using mussel data compiled from various sources and explanatory variables derived from GIS coverages. Prediction success of CART models for presence-absence of mussels ranged from 71 to 76% across three gears (brail, sled-dredge, and dive-quadrat) and 51% of the deviance in abundance. Models were largely driven by shear stress and substrate stability variables, but interactions with simple physical variables, especially slope, were also important. Geospatial models, which were based on tree model results, predicted few mussels in poorly connected backwater areas (e.g., floodplain lakes) and the navigation channel, whereas main channel border areas with high geomorphic complexity (e.g., river bends, islands, side channel entrances) and small side channels were typically favorable to mussels. Moreover, bootstrap aggregation of discharge-specific regression tree models of dive-quadrat data indicated that variables measured at low discharge were about 25% more predictive (PMSE = 14.8) than variables measured at median discharge (PMSE = 20.4) with high discharge (PMSE = 17.1) variables intermediate. This result suggests that episodic events such as droughts and floods were important in structuring mussel distributions. Although the substantial mussel and ancillary data in our study reach is unusual, our approach to develop exploratory statistical and geospatial models should be useful even when data are more limited. ?? 2007 Springer Science+Business Media B.V.

  18. The Use of Numerical Modeling in the Planning of Physical Model Tests in a Multidirectional Wave Basin

    DEFF Research Database (Denmark)

    Carci, Enric; Rivero, Francisco J.; Burcharth, Hans Falk

    2003-01-01

    For the development of a new port of the A Coruña Port Authority, an extensive and careful analysis of wave propagation had to be done to determine design wave characteristics along the main breakwater, placed behind an irregular shoal. Preliminary numerical simulations showed that wave focusing...

  19. The importance of food, nutrition and physical activity in cancer prevention: an interview with Dr Kate Allen.

    Science.gov (United States)

    Allen, Kate

    2018-05-02

    Kate Allen speaks to Roshaine Wijayatunga, Managing Commissioning Editor. Dr Kate Allen works as an Executive Director in Science and Public Affairs at World Cancer Research Fund International ( http://wcrf.org ), an NGO and leading authority in the field of cancer prevention through diet, weight and physical activity. Kate is responsible for the organization's scientific, policy and conference programs in the areas of food, nutrition, physical activity and weight management. An important aspect of her role is helping to create collaborative relationships and activities across the WCRF national charities (in Europe, America and Asia) in these areas, as well as maintaining and creating external partnerships. Previously, Kate worked at the Institute of Cancer Research, where she set up an award-winning Interactive Education Unit to develop learning materials for scientists, healthcare professionals, students, patients and the general public. Before that she worked at Medi Cine International, a medical education agency, where she developed educational materials across all media, mainly for specialist physician audiences. Kate has a PhD in neuroscience, carried out at the Institute of Neurology and the National Hospital for Neurology and Neurosurgery at Queen Square, London and the Royal College of Surgeons of England. The Third Expert Report that Kate mentions in the interview, featuring the updated World Cancer Research Fund Cancer Prevention Recommendations is launched 24 May 2018. For more information see http://wcrf.org .

  20. Numerical and physical modeling of water flow over the ogee weir of the new Niedów barrage

    Directory of Open Access Journals (Sweden)

    Herrera-Granados Oscar

    2016-03-01

    Full Text Available In this paper, two- and three-dimensional numerical modeling is applied in order to simulate water flow behavior over the new Niedów barrage in South Poland. The draining capacity of one of the flood alleviation structures (ogee weir for exploitation and catastrophic conditions was estimated. In addition, the output of the numerical models is compared with experimental data. The experiments demonstrated that the draining capacity of the barrage alleviation scheme is sufficiently designed for catastrophic scenarios if water is flowing under steady flow conditions. Nevertheless, the new cofferdam, which is part of the temporal reconstruction works, is affecting the draining capacity of the whole low-head barrage project.

  1. Computational physics

    CERN Document Server

    Newman, Mark

    2013-01-01

    A complete introduction to the field of computational physics, with examples and exercises in the Python programming language. Computers play a central role in virtually every major physics discovery today, from astrophysics and particle physics to biophysics and condensed matter. This book explains the fundamentals of computational physics and describes in simple terms the techniques that every physicist should know, such as finite difference methods, numerical quadrature, and the fast Fourier transform. The book offers a complete introduction to the topic at the undergraduate level, and is also suitable for the advanced student or researcher who wants to learn the foundational elements of this important field.

  2. Physical modeling and numerical simulation of subcooled boiling in one- and three-dimensional representation of bundle geometry

    International Nuclear Information System (INIS)

    Bottoni, M.; Lyczkowski, R.; Ahuja, S.

    1995-01-01

    Numerical simulation of subcooled boiling in one-dimensional geometry with the Homogeneous Equilibrium Model (HEM) may yield difficulties related to the very low sonic velocity associated with the HEM. These difficulties do not arise with subcritical flow. Possible solutions of the problem include introducing a relaxation of the vapor production rate. Three-dimensional simulations of subcooled boiling in bundle geometry typical of fast reactors can be performed by using two systems of conservation equations, one for the HEM and the other for a Separated Phases Model (SPM), with a smooth transition between the two models

  3. Reconstructing the early 19th-century Waal River by means of a 2D physics-based numerical model

    NARCIS (Netherlands)

    Montes Arboleda, A.; Crosato, A.; Middelkoop, H.

    2010-01-01

    Suspended-sediment concentration data are a missing link in reconstructions of the River Waal in the early 1800s. These reconstructions serve as a basis for assessing the long-term effects of major interventions carried out between 1850 AD and the early 20th century. We used a 2D physics-based

  4. Importance of physical examination in early detection of lump in breast in women of different age groups

    International Nuclear Information System (INIS)

    Abbas, H.; Imran, S.; Waris, Noorul-ain-Hafeez; Khanam, A.; Khurshid, R.

    2010-01-01

    Background: The spectrum of breast lesions in adolescents varies markedly from that for adults, with the former lesions being overwhelmingly benign. Fine needle biopsy can be used to distinguish benign and malignant tumour. Study Design: This study examined the characteristics and outcome of women with different age groups in whom physical examination was their sole method of lump in breast detection. Patients and Methods: A total of 200 patients were included in the study. These were divided into 3 groups. Group A was consisting of 75 girls with age of pubescent. Group B included 69 suspected breast cancer women with age range 26-38 years. Fifty-six suspected breast cancer women with age range 41-60 year were included as group C. Study was carried out in patients admitted in the Department/Out-door of Surgery, Sir Ganga Ram Hospital, Lahore, Pakistan. Study period was 6 months. All women received a physical examination by a breast surgeon. Proforma including demographic and clinical characteristics were filled. The diagnosis for patients in this study was achieved by core needle biopsy using a 14-gauge cutting needle. Results: It was observed that early age at menarche ( 25 may be a risk factor in peri/post menopausal women. Active life style is more important with increasing age as it decreases the risk of developing tumour state. Family history was more common in women with peri/post menopausal status as compared to other age groups. Clinical characteristics showed that lump size <2.5 cm was more common in both pubescent and reproductive age. While lump size with a range of 2.5-5.0 cm, was observed in all groups of patients. Fibroadenoma is observed in almost all women with pubescent age while both benign and malignant tumour observed in women with reproductive age. Malignant tumour was observed mostly in women with peri/post menopausal status. Conclusion: Study concluded that early detection or clinical examination with FNA cut out the patients from harassment

  5. An Experimental Assessment of Physical Educators' Expectations and Attitudes: The Importance of Student Weight and Gender

    Science.gov (United States)

    Peterson, Jamie Lee; Puhl, Rebecca M.; Luedicke, Joerg

    2012-01-01

    Background: At school, physical education (PE) teachers and coaches may be key supports for physical activity. Unfortunately, PE teachers may endorse negative stereotypes and attitudes toward overweight youth. These biases may influence the amount of instruction physical educators provide to students and their participation in PE or other physical…

  6. Comparison of a Physical and Numerical Mobile-Bed Model of Beach and T-Head Groin Interaction

    Science.gov (United States)

    2011-05-01

    Hydraulic Centre’s Large Area Basin (LAB), utilizing a set of moveable wave generators capable of providing long-crested waves to match a variety...was conducted manually from a bridge as shown in Figure 4. The location of the transect (Profile 2) is shown in Figure 2. Planform morphology was...4. Physical model oblique view showing profile measurement location and bridge . 2617 The T-head groins and the shore-normal breakwater trunk at the

  7. Improvement of a mesoscale atmospheric dynamic model PHYSIC. Utilization of output from synoptic numerical prediction model for initial and boundary condition

    International Nuclear Information System (INIS)

    Nagai, Haruyasu; Yamazawa, Hiromi

    1995-03-01

    This report describes the improvement of the mesoscale atmospheric dynamic model which is a part of the atmospheric dispersion calculation model PHYSIC. To introduce large-scale meteorological changes into the mesoscale atmospheric dynamic model, it is necessary to make the initial and boundary conditions of the model by using GPV (Grid Point Value) which is the output of the numerical weather prediction model of JMA (Japan Meteorological Agency). Therefore, the program which preprocesses the GPV data to make a input file to PHYSIC was developed and the input process and the methods of spatial and temporal interpolation were improved to correspond to the file. Moreover, the methods of calculating the cloud amount and ground surface moisture from GPV data were developed and added to the model code. As the example of calculation by the improved model, the wind field simulations of a north-west monsoon in winter and a sea breeze in summer in the Tokai area were also presented. (author)

  8. Numerical Verification Of Equilibrium Chemistry

    International Nuclear Information System (INIS)

    Piro, Markus; Lewis, Brent; Thompson, William T.; Simunovic, Srdjan; Besmann, Theodore M.

    2010-01-01

    A numerical tool is in an advanced state of development to compute the equilibrium compositions of phases and their proportions in multi-component systems of importance to the nuclear industry. The resulting software is being conceived for direct integration into large multi-physics fuel performance codes, particularly for providing boundary conditions in heat and mass transport modules. However, any numerical errors produced in equilibrium chemistry computations will be propagated in subsequent heat and mass transport calculations, thus falsely predicting nuclear fuel behaviour. The necessity for a reliable method to numerically verify chemical equilibrium computations is emphasized by the requirement to handle the very large number of elements necessary to capture the entire fission product inventory. A simple, reliable and comprehensive numerical verification method is presented which can be invoked by any equilibrium chemistry solver for quality assurance purposes.

  9. Importance of soil-water relation in assessment endpoint in bioremediated soils: Plant growth and soil physical properties

    International Nuclear Information System (INIS)

    Li, X.; Sawatsky, N.

    1995-01-01

    Much effort has been focused on defining the end-point of bioremediated soils by chemical analysis (Alberta Tier 1 or CCME Guideline for Contaminated Soils) or toxicity tests. However, these tests do not completely assess the soil quality, or the capability of soil to support plant growth after bioremediation. This study compared barley (Hordeum vulgare) growth on: (i) non-contaminated, agricultural topsoil, (2) oil-contaminated soil (4% total extractable hydrocarbons, or TEH), and (3) oil-contaminated soil treated by bioremediation (< 2% TEH). Soil physical properties including water retention, water uptake, and water repellence were measured. The results indicated that the growth of barley was significantly reduced by oil-contamination of agricultural topsoil. Furthermore, bioremediation did not improve the barley yield. The lack of effects from bioremediation was attributed to development of water repellence in hydrocarbon contaminated soils. There seemed to be a critical water content around 18% to 20% in contaminated soils. Above this value the water uptake by contaminated soil was near that of the agricultural topsoil. For lower water contents, there was a strong divergence in sorptivity between contaminated and agricultural topsoil. For these soils, water availability was likely the single most important parameter controlling plant growth. This parameter should be considered in assessing endpoint of bioremediation for hydrocarbon contaminated soils

  10. Assessing the Importance of Social and Environmental Supports for Leisure-Time Physical Activity in a Unique Socio-Cultural and Geographical Context

    Science.gov (United States)

    Gauthier, Alain P.; Lariviere, Michel; Pong, Raymond; Snelling, Susan J.; Young, Nancy L.

    2010-01-01

    Researchers have found important differences among population sub-groups when considering their "determinants of physical activity". The health of Francophones and Northern Ontario residents in Canada has been assessed as relatively poorer than the general population. Understanding the determinants of physical activity in these…

  11. Investigation on the Influence of Abutment Pressure on the Stability of Rock Bolt Reinforced Roof Strata Through Physical and Numerical Modeling

    Science.gov (United States)

    Kang, Hongpu; Li, Jianzhong; Yang, Jinghe; Gao, Fuqiang

    2017-02-01

    In underground coal mining, high abutment loads caused by the extraction of coal can be a major contributor to many rock mechanic issues. In this paper, a large-scale physical modeling of a 2.6 × 2.0 × 1.0 m entry roof has been conducted to investigate the fundamentals of the fracture mechanics of entry roof strata subjected to high abutment loads. Two different types of roof, massive roof and laminated roof, are considered. Rock bolt system has been taken into consideration. A distinct element analyses based on the physical modeling conditions have been performed, and the results are compared with the physical results. The physical and numerical models suggest that under the condition of high abutment loads, the massive roof and the laminated roof fail in a similar pattern which is characterized as vertical tensile fracturing in the middle of the roof and inclined shear fracturing initiated at the roof and rib intersections and propagated deeper into the roof. Both the massive roof and the laminated roof collapse in a shear sliding mode shortly after shear fractures are observed from the roof surface. It is found that shear sliding is a combination of tensile cracking of intact rock and sliding on bedding planes and cross joints. Shear sliding occurs when the abutment load is much less than the compressive strength of roof.

  12. The importance of physical activity in the prevention of overweight and obesity in childhood: a review and an opinion.

    Science.gov (United States)

    Steinbeck, K S

    2001-05-01

    The prevalence of childhood obesity is increasing and there are a number of theoretical reasons as to why intervention may be more effective in childhood. There are certain risk times for the development of obesity in childhood, which provide a basis for targeted intervention. In addition, tracking data supports the persistence of obesity, at least in later childhood, as well as cardiovascular risk factors. Physical activity is the discretionary component of energy expenditure and there is evidence that falling levels of physical activity are contributing to the obesity epidemic. Physical activity in children is related to developmental stage, is reduced with increasing age and is influenced by parental physical activity. While there is debate about the immediate health benefits of physical activity to children, there are data to support that lower physical activity levels and sedentary behaviours are associated with a higher prevalence of obesity in children. Physical activity is an accepted strategy in the treatment of established obesity (tertiary prevention). The role of physical activity in the prevention of obesity (primary and secondary prevention) is less clear. However a number of recent school-based interventions directed at either increasing physical activity and/or decreasing sedentary behaviours, have shown encouraging results. On balance, increasing physical activity in children is an attractive and non-restrictive approach to obesity prevention. To adopt this approach requires the support and involvement of many community sectors other than health.

  13. Physical and numerical modelings of lateral drag in a pipeline in very soft clay; Modelagens fisica e numerica de arraste lateral de duto em argila mole

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Jose Renato M.S.; Almeida, Maria C.F.; Almeida, Marcio S.S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Borges, Ricardo G.; Amaral, Claudio S. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2005-07-01

    This paper discusses some results from a joint research project undertaken by COPPE/UFRJ and CENPES/PETROBRAS about soil-structure interaction applied to thermal snaking of shallowly buried pipelines embedded in very soft clay. At this phase, the lateral soil reaction due to pipeline horizontal displacements was studied by means of physical and numerical modeling. In that way, a set of comprehensive centrifuge tests has been undertaken using a 1:30 scaled pipe dragged laterally, varying the burial depth condition. The soil used for the tests is a very soft clay sample collected at the Duque de Caxias Refinery area in Rio de Janeiro. The vertical and horizontal displacements of the pipe were imposed by computer-controlled actuators, with soil reaction forces being measured on both directions. The physical modeling results were compared with numerical simulations of the same centrifuge scenarios using the software AEEPECD, developed by PETROBRAS, showing good agreement in terms of horizontal and vertical soil reactions. (author)

  14. 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...

  15. Estimating Hydraulic Resistance for Floodplain Mapping and Hydraulic Studies from High-Resolution Topography: Physical and Numerical Simulations

    Science.gov (United States)

    Minear, J. T.

    2017-12-01

    One of the primary unknown variables in hydraulic analyses is hydraulic resistance, values for which are typically set using broad assumptions or calibration, with very few methods available for independent and robust determination. A better understanding of hydraulic resistance would be highly useful for understanding floodplain processes, forecasting floods, advancing sediment transport and hydraulic coupling, and improving higher dimensional flood modeling (2D+), as well as correctly calculating flood discharges for floods that are not directly measured. The relationship of observed features to hydraulic resistance is difficult to objectively quantify in the field, partially because resistance occurs at a variety of scales (i.e. grain, unit and reach) and because individual resistance elements, such as trees, grass and sediment grains, are inherently difficult to measure. Similar to photogrammetric techniques, Terrestrial Laser Scanning (TLS, also known as Ground-based LiDAR) has shown great ability to rapidly collect high-resolution topographic datasets for geomorphic and hydrodynamic studies and could be used to objectively quantify the features that collectively create hydraulic resistance in the field. Because of its speed in data collection and remote sensing ability, TLS can be used both for pre-flood and post-flood studies that require relatively quick response in relatively dangerous settings. Using datasets collected from experimental flume runs and numerical simulations, as well as field studies of several rivers in California and post-flood rivers in Colorado, this study evaluates the use of high-resolution topography to estimate hydraulic resistance, particularly from grain-scale elements. Contrary to conventional practice, experimental laboratory runs with bed grain size held constant but with varying grain-scale protusion create a nearly twenty-fold variation in measured hydraulic resistance. The ideal application of this high-resolution topography

  16. Quantum molecular dynamics: Numerical methods and physical study of the structure, thermodynamics, stability and fragmentation of sodium metallic clusters

    International Nuclear Information System (INIS)

    Blaise, Philippe

    1998-01-01

    The aim of this thesis is to study metallic sodium clusters by numerical simulation. We have developed two ab initio molecular dynamics programs within the formalism of density functional theory. The first is based on the semi-classical extended Thomas-Fermi approach. We use a real-space grid and a Car-Parrinello-like scheme. The computational cost is O(N), and we have built a pseudopotential that speeds up the calculations. By neglecting quantum shell effects, we are able to study a very large set of clusters. We show that sodium cluster energies fit well a liquid drop formula, by adjusting a few parameters. We have investigated breathing modes, surface oscillations and the net charge density. We have shown that the surface energy varies strongly with temperature, and that clusters have a lower melting point than bulk material. We have calculated fission barriers by a constraint method. The second program is based on the quantum Kohn-Sham approach. We use a real-space grid, and combine a generalized Broyden scheme for assuring self-consistency with an iterative Davidson-Lanczos algorithm for solving the Eigen-problem. The cost of the method is much higher. First of all, we have calculated some stable structures for small clusters and their energetics. We obtained very good agreement with previous works. Then, we have investigated highly charged cluster dynamics. We have identified a chaotic fission process. For high fissility systems, we observe a multi-fragmentation dynamics and we find preferential emission of monomers on a characteristic time scale less than a pico-second. This has been simulated for the first time, with the help of our adaptive grid method which follows each fragment as they move apart during the fragmentation. (author)

  17. The Electrocardiogram as an Electronic Filter and Why AC Circuits Are Important for Pre-Health Physics Students

    Science.gov (United States)

    Dunlap, Justin C.; Kutschera, Ellynne; Van Ness, Grace R.; Widenhorn, Ralf

    2015-01-01

    We present a general physics laboratory exercise that centres around the use of the electrocardiogram sensor as an application of circuits and electronic signal filtering. Although these topics are commonly taught in the general physics classroom, many students consider topics such as alternating current as unrelated to their future professions.…

  18. Exercise dependence score in patients with longstanding eating disorders and controls: the importance of affect regulation and physical activity intensity.

    Science.gov (United States)

    Bratland-Sanda, Solfrid; Martinsen, Egil W; Rosenvinge, Jan H; Rø, Oyvind; Hoffart, Asle; Sundgot-Borgen, Jorunn

    2011-01-01

    To examine associations among exercise dependence score, amount of physical activity and eating disorder (ED) symptoms in patients with longstanding ED and non-clinical controls. Adult female inpatients (n = 59) and 53 age-matched controls participated in this cross sectional study. Assessments included the eating disorders examination, eating disorders inventory, exercise dependence scale, reasons for exercise inventory, and MTI Actigraph accelerometer. Positive associations were found among vigorous, not moderate, physical activity, exercise dependence score and ED symptoms in patients. In the controls, ED symptoms were negatively associated with vigorous physical activity and not correlated with exercise dependence score. Exercise for negative affect regulation, not weight/appearance, and amount of vigorous physical activity were explanatory variables for exercise dependence score in both groups. The positive associations among exercise dependence score, vigorous physical activity and ED symptoms need proper attention in the treatment of longstanding ED. Copyright © 2011 John Wiley & Sons, Ltd and Eating Disorders Association.

  19. Numerical Simulation of Flow Features and Energy Exchange Physics in Near-Wall Region with Fluid-Structure Interaction

    Science.gov (United States)

    Zhang, Lixiang; Wang, Wenquan; Guo, Yakun

    Large eddy simulation is used to explore flow features and energy exchange physics between turbulent flow and structure vibration in the near-wall region with fluid-structure interaction (FSI). The statistical turbulence characteristics in the near-wall region of a vibrating wall, such as the skin frictional coefficient, velocity, pressure, vortices, and the coherent structures have been studied for an aerofoil blade passage of a true three-dimensional hydroturbine. The results show that (i) FSI greatly strengthens the turbulence in the inner region of y+ < 25; and (ii) the energy exchange mechanism between the flow and the vibration depends strongly on the vibration-induced vorticity in the inner region. The structural vibration provokes a frequent action between the low- and high-speed streaks to balance the energy deficit caused by the vibration. The velocity profile in the inner layer near the vibrating wall has a significant distinctness, and the viscosity effect of the fluid in the inner region decreases due to the vibration. The flow features in the inner layer are altered by a suitable wall vibration.

  20. Particle physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  1. The electrocardiogram as an electronic filter and why ac circuits are important for pre-health physics students

    Science.gov (United States)

    Dunlap, Justin C.; Kutschera, Ellynne; Van Ness, Grace R.; Widenhorn, Ralf

    2015-01-01

    We present a general physics laboratory exercise that centres around the use of the electrocardiogram sensor as an application of circuits and electronic signal filtering. Although these topics are commonly taught in the general physics classroom, many students consider topics such as alternating current as unrelated to their future professions. This exercise provides the motivation for life science and pre-health majors to learn concepts such as voltage, resistance, alternating and direct current, RLC circuits, as well as signal and noise, in an introductory undergraduate physics lab.

  2. The influence of heterogeneity on coastal groundwater flow - physical and numerical modeling of fringing reefs, dykes and structured conductivity fields

    Science.gov (United States)

    Houben, Georg J.; Stoeckl, Leonard; Mariner, Katrina E.; Choudhury, Anis S.

    2018-03-01

    Geological heterogeneity of the subsurface, caused by both discrete features and spatially distributed hydraulic conductivity fields, affects the flow of coastal groundwater. It influences the shape and the position of the interface between saltwater and freshwater, as well as the location and flux rate of freshwater discharge to the ocean. Fringing reefs lead to a bimodal regime of freshwater discharge, with discharge at the beach face and through deeper, submarine springs. Impermeable vertical flow barriers (dykes) lead to an impoundment of fresh groundwater and a compartmentalization of the aquifer but also to a delayed expulsion of saline water. Spatially distributed conductivity fields affect the shape of the interface and the geometry of the saltwater wedge. Higher effective conductivities lead to a further landward intrusion of the wedge toe. These flow characteristics can be important for groundwater extraction, the delineation of protection zones and the assessment of contaminant transport to coastal ecosystems.

  3. 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...

  4. Numerical analysis

    CERN Document Server

    Jacques, Ian

    1987-01-01

    This book is primarily intended for undergraduates in mathematics, the physical sciences and engineering. It introduces students to most of the techniques forming the core component of courses in numerical analysis. The text is divided into eight chapters which are largely self-contained. However, with a subject as intricately woven as mathematics, there is inevitably some interdependence between them. The level of difficulty varies and, although emphasis is firmly placed on the methods themselves rather than their analysis, we have not hesitated to include theoretical material when we consider it to be sufficiently interesting. However, it should be possible to omit those parts that do seem daunting while still being able to follow the worked examples and to tackle the exercises accompanying each section. Familiarity with the basic results of analysis and linear algebra is assumed since these are normally taught in first courses on mathematical methods. For reference purposes a list of theorems used in the t...

  5. Effects of Turbulent Magnetic Fields on the Transport and Acceleration of Energetic Charged Particles: Numerical Simulations with Application to Heliospheric Physics

    Science.gov (United States)

    Guo, Fan

    2012-11-01

    Turbulent magnetic fields are ubiquitous in space physics and astrophysics. The influence of magnetic turbulence on the motions of charged particles contains the essential physics of the transport and acceleration of energetic charged particles in the heliosphere, which is to be explored in this thesis. After a brief introduction on the energetic charged particles and magnetic fields in the heliosphere, the rest of this dissertation focuses on three specific topics: 1. the transport of energetic charged particles in the inner heliosphere, 2. the acceleration of ions at collisionless shocks, and 3. the acceleration of electrons at collisionless shocks. We utilize various numerical techniques to study these topics. In Chapter 2 we study the propagation of charged particles in turbulent magnetic fields similar to the propagation of solar energetic particles in the inner heliosphere. The trajectories of energetic charged particles in the turbulent magnetic field are numerically integrated. The turbulence model includes a Kolmogorov-like magnetic field power spectrum containing a broad range of scales from those that lead to large-scale field-line random walk to small scales leading to resonant pitch-angle scattering of energetic particles. We show that small-scale variations in particle intensities (the so-called "dropouts") and velocity dispersions observed by spacecraft can be reproduced using this method. Our study gives a new constraint on the error of "onset analysis", which is a technique commonly used to infer information about the initial release of energetic particles. We also find that the dropouts are rarely produced in the simulations using the so-called "two-component" magnetic turbulence model (Matthaeus et al., 1990). The result questions the validity of this model in studying particle transport. In the first part of Chapter 3 we study the acceleration of ions in the existence of turbulent magnetic fields. We use 3-D self-consistent hybrid simulations

  6. Numerical Simulation of Early Age Cracking of Reinforced Concrete Bridge Decks with a Full-3D Multiscale and Multi-Chemo-Physical Integrated Analysis

    Directory of Open Access Journals (Sweden)

    Tetsuya Ishida

    2018-03-01

    Full Text Available In November 2011, the Japanese government resolved to build “Revival Roads” in the Tohoku region to accelerate the recovery from the Great East Japan Earthquake of March 2011. Because the Tohoku region experiences such cold and snowy weather in winter, complex degradation from a combination of frost damage, chloride attack from de-icing agents, alkali–silica reaction, cracking and fatigue is anticipated. Thus, to enhance the durability performance of road structures, particularly reinforced concrete (RC bridge decks, multiple countermeasures are proposed: a low water-to-cement ratio in the mix, mineral admixtures such as ground granulated blast furnace slag and/or fly ash to mitigate the risks of chloride attack and alkali–silica reaction, anticorrosion rebar and 6% entrained air for frost damage. It should be noted here that such high durability specifications may conversely increase the risk of early age cracking caused by temperature and shrinkage due to the large amounts of cement and the use of mineral admixtures. Against this background, this paper presents a numerical simulation of early age deformation and cracking of RC bridge decks with full 3D multiscale and multi-chemo-physical integrated analysis. First, a multiscale constitutive model of solidifying cementitious materials is briefly introduced based on systematic knowledge coupling microscopic thermodynamic phenomena and microscopic structural mechanics. With the aim to assess the early age thermal and shrinkage-induced cracks on real bridge deck, the study began with extensive model validations by applying the multiscale and multi-physical integrated analysis system to small specimens and mock-up RC bridge deck specimens. Then, through the application of the current computational system, factors that affect the generation and propagation of early age thermal and shrinkage-induced cracks are identified via experimental validation and full-scale numerical simulation on real

  7. Physical and numerical modelling of natural convection in a fluid layer of small aspect ratio, in the frame of severe accidents of nuclear pressurized water reactors

    International Nuclear Information System (INIS)

    Villermaux, Clotilde

    1999-01-01

    In the framework of PWR reactor accidents studies, the possibility of cooling the corium by the vessel flooding, is analysed. A particular attention is given to the liquid materials of the upper part of this pool. The confinement and the physical properties of this melt pool, may threat the vessel integrity by a heat flux concentration on the vessel lateral wall. A bibliographic study on the thermal transfers in natural convection, enhances the influence of the thermal extreme conditions and the layer geometry on the flow structure and the heat distribution. The lower part of the corium is constituted of an oxides layer. A stability study shows its perenniality: the metallic layer can be slipped of the oxides pool. The results analysis of the experimental program, BALI-metal, is completed by a direct numerical simulation with the TRIOU code. A model of the flow structure allows the find in bulk the experimental results. Finally a numerical simulation of the experimental tests is realized with the thermo-hydraulic code TOLBIAC. (A.L.B.)

  8. Nitrogen Retention in Coastal Marine Sediments—a Field Study of the Relative Importance of Biological and Physical Removal in a Danish Estuary

    DEFF Research Database (Denmark)

    Laurentius Nielsen, Søren; Risgaard-Petersen, Nils; Banta, Gary

    2017-01-01

    The aim of this study was to elucidate the relative importance of physical versus biological loss processes for the removal of microphytobenthic (MPB) bound nitrogen in a coastal environment at different times of the year via a dual isotope labeling technique. We used 51Cr, binding to inorganic...... were able to discern the relative importance of physical and biological processes. The isotope marking was supplemented with measurements of sediment chlorophyll biomass and oxygen fluxes, allowing us to evaluate MPB biomass as well as primary production vs. respiration in the sediment. In spring...... was physically dominated due to low MPB biomasses and activity combined with a significant storm event. Our data support the hypothesis that the relative balance between physical and biological processes in determining retention and removal of MPB-bound nitrogen changes seasonally....

  9. Rank acquisition in rhesus macaque yearlings following permanent maternal separation: The importance of the social and physical environment.

    Science.gov (United States)

    Wooddell, Lauren J; Kaburu, Stefano S K; Murphy, Ashley M; Suomi, Stephen J; Dettmer, Amanda M

    2017-11-01

    Rank acquisition is a developmental milestone for young primates, but the processes by which primate yearlings attain social rank in the absence of the mother remain unclear. We studied 18 maternally reared yearling rhesus macaques (Macaca mulatta) that differed in their social and physical rearing environments. We found that early social experience and maternal rank, but not individual traits (weight, sex, age), predicted dominance acquisition in the new peer-only social group. Yearlings also used coalitions to reinforce the hierarchy, and social affiliation (play and grooming) was likely a product, rather than a determinant, of rank acquisition. Following relocation to a familiar environment, significant rank changes occurred indicating that familiarity with a physical environment was salient in rank acquisition. Our results add to the growing body of literature emphasizing the role of the social and physical environment on behavioral development, namely social asymmetries among peers. © 2017 Wiley Periodicals, Inc.

  10. Fear of Movement and Low Self-Efficacy Are Important Barriers in Physical Activity after Renal Transplantation

    NARCIS (Netherlands)

    Zelle, Dorien M; Corpeleijn, Eva; Klaassen, Gerald; Schutte, Elise; Navis, Gerjan; Bakker, Stephan J L

    2016-01-01

    Background Physical activity (PA) and exercise are commonly used as preventive measures for cardiovascular disease in the general population, and could be effective in the management of post-transplantation cardiovascular risk. PA levels are low after renal transplantation and very few renal

  11. 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...

  12. Assessment of pedometer-determined physical activity in Danish adults: the importance of non-ambulatory activities

    DEFF Research Database (Denmark)

    Rothausen, Berit Worm; Gille, Maj-Britt; Biltoft-Jensen, Anja Pia

    and Physical Activity 2007-08, wore a pedometer (Yamax SW-200 Tokyo, Japan) and recorded daily steps and non-ambulatory activities for seven consecutive days. Time spent on non-ambulatory activities was converted to step equivalents using 1) a simple conversion method (SCM) adding 200 step equivalents...... assessing pedometer-determined physical activity. Adding activity-specific step equivalents/min, or simply adding 200 step equivalents/min, provides very similar results. Furthermore, when accounting for cycling an adjustment for double-counting should be considered.......Purpose To estimate mean values of steps/day in a representative sample of Danish adults (15-75 years) using two different conversion methods for non-ambulatory (non-step) activities. Methods A simple random sample comprising 229 adults (52% men) from the Danish National Survey of Dietary Habits...

  13. Importance of Students' Views and the Role of Self-Esteem in Lessons of Creative Dance in Physical Education

    Science.gov (United States)

    Steinberg, Claudia; Steinberg, Fabian

    2016-01-01

    The purpose of this study was to capture the student's views in lessons of creative dance. A qualitative empirical research design was carried out using video-stimulated recall interviews. The participants in this study were 88 children (63 female and 25 male) between the ages of 9 and 11 years (M = 10.5, SD = 1.2) in physical education lessons. A…

  14. 'It's important that we learn too': Empowering parents to facilitate participation in physical activity for children and youth with disabilities.

    Science.gov (United States)

    Willis, Claire E; Reid, Siobhan; Elliott, Catherine; Nyquist, Astrid; Jahnsen, Reidun; Rosenberg, Michael; Girdler, Sonya

    2017-09-20

    The actions and behaviors of parents have been identified as key factors that influence a child's participation in physical activity. However, there is limited knowledge of how parents can be supported to embody facilitative roles. This study aimed to explore how an ecological intervention encourages parents of children with disabilities to develop as facilitators, to enable ongoing physical activity participation in a child's local environment. A qualitative design using grounded theory was employed. Forty four parents (26 mothers, 18 fathers) of 31 children with a range of disabilities (mean age 12y 6m (SD 2y 2m); 18 males) partaking in the Local Environment Model intervention at Beitostolen Healthsports Centre in Norway participated in the study. Data were derived from the triangulation of semi-structured interviews and participant observation. Data analysis was an iterative approach of constant comparison, where data collection, memo writing, open, axial and selective coding analysis, were undertaken simultaneously. Findings were consolidated into a model describing the central phenomenon and its relationship to other categories. Thematic concepts uncovered in this study describe a social process of parent learning and empowerment, comprising three primary components; (i) active ingredients of the intervention that enabled learning and empowerment to transpire, (ii) parent learning and empowerment as a process, and (iii) related outcomes. A family-centered approach, encompassing family-to-family support, may enhance physical activity participation outcomes for children and youth with disabilities.

  15. Numerical modelling in material physics

    International Nuclear Information System (INIS)

    Proville, L.

    2004-12-01

    The author first briefly presents his past research activities: investigation of a dislocation sliding in solid solution by molecular dynamics, modelling of metal film growth by phase field and Monte Carlo kinetics, phase field model for surface self-organisation, phase field model for the Al 3 Zr alloy, calculation of anharmonic photons, mobility of bipolarons in superconductors. Then, he more precisely reports the mesoscopic modelling in phase field, and some atomistic modelling (dislocation sliding, Monte Carlo simulation of metal surface growth, anharmonic network optical spectrum modelling)

  16. Physical Activity Might Be of Greater Importance for Good Spinal Control Than If You Have Had Pain or Not: A Longitudinal Study.

    Science.gov (United States)

    Aasa, Ulrika; Lundell, Sara; Aasa, Björn; Westerståhl, Maria

    2015-12-01

    Longitudinal design. A cohort followed in 3 waves of data collection. The aim of the study was to describe the relationships between the performance of 2 tests of spinal control at the age of 52 years and low back pain, physical activity level, and fitness earlier in life, as well as to describe the cross-sectional relationships between these measures. Altered spinal control has been linked to pain; however, other stimuli may also lead to inability to control the movements of the spine. Participants answered questions about physical activity and low back pain, and performed physical fitness tests at the age of 16, 34, and 52 years. The fitness test battery included tests of endurance in the back and abdominal muscles, a submaximal bicycle ergometer test to estimate maximal oxygen uptake, and measurements of hip flexion, thoracic spine flexibility, and anthropometrics. Two tests were aggregated to a physical fitness index. At the age of 52, also 2 tests of spinal control, the standing Waiter's bow (WB) and the supine double leg lower (LL) were performed. Logistic regression analyses showed that higher back muscle endurance at the age of 34 years could positively predict WB performance at 52 years and higher physical fitness at the age of 34 could positively predict LL performance at 52 years. Regarding cross-sectional relationships, an inability to perform the WB correctly was associated with lower physical fitness, flexibility and physical activity, and larger waist circumference. An inability to correctly perform the LL was associated with lower physical fitness. One-year prevalence of pain was not significantly associated with WB or LL test performance. An active life resulting in higher physical fitness is related to better spinal control in middle-aged men and women. This further strengthens the importance of physical activity throughout the life span. 3.

  17. Decreased physical effort, fatigue, and mental distress in patients with coronary artery disease : Importance of personality-related differences

    NARCIS (Netherlands)

    Bunevicius, A.; Brozaitiene, J.; Staniute, M.; Gelziniene, V.; Duoneliene, I.; Pop, V.J.M.; Bunevicius, R.; Denollet, J.

    2014-01-01

    Background Identification of cardio-toxic psychological symptoms in coronary artery disease (CAD) patients is important. Purpose We examined the association of negative affectivity (NA), social inhibition (SI), and their combination in the distressed (Type D) personality with functional status,

  18. Importance of characteristics and modalities of physical activity and exercise in the management of cardiovascular health in individuals with cardiovascular risk factors

    DEFF Research Database (Denmark)

    Vanhees, L; Geladas, N; Hansen, D

    2012-01-01

    In a previous paper, as the first of a series of three on the importance of characteristics and modalities of physical activity (PA) and exercise in the management of cardiovascular health within the general population, we concluded that, in the population at large, PA and aerobic exercise capacity...

  19. 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 ...

  20. A new numerical investigation of some thermo-physical properties on unsteady MHD non-Darcian flow past an impulsively started vertical surface

    Directory of Open Access Journals (Sweden)

    Motsa Sandile Sydney

    2015-01-01

    Full Text Available The behaviour of unsteady non-Darcian magnetohydrodynamic fluid flow past an impulsively started vertical porous surface is investigated. The effect of thermophoresis due to migration of colloidal particles in response to a macroscopic temperature gradient is taken into account. It is assumed that both dynamic viscosity and thermal conductivity are linear functions of temperature. The governing equations are non-dimensionalized by using suitable similarity transformation which can unravel the behaviour of the flow at short time and long time periods. A novel iteration scheme, called bivariate spectral local linearization method is developed for solving the corresponding systems of highly non-linear partial differential equations. The results of the numerical solutions obtained are presented graphically and analyzed for the effects of the various important parameters entering into the problem on velocity, temperature, and concentration field within the boundary layer.

  1. 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...

  2. Understanding the Importance of Context: A Qualitative Study of a Location-Based Exergame to Enhance School Childrens Physical Activity.

    Directory of Open Access Journals (Sweden)

    Judy Robertson

    Full Text Available Many public health interventions are less effective than expected in 'real life settings', yet little work is undertaken to understand the reasons why. The effectiveness of complex public health interventions can often be traced back to a robust programme theory (how and why an intervention brings about a change in outcome(s and assumptions that are made about the context in which it is implemented. Understanding whether effectiveness (or lack thereof is due to the intervention or the context is hugely helpful in decisions about whether to a modify the intervention; b modify the context; c stop providing the intervention. Exergames-also known as Active Video Games or AVGS-are video games which use the player's bodily movements as input and have potential to increase physical activity in children. However, the results of a recent pilot randomised controlled trial (RCT of a location-based exergame (FitQuest in a school setting were inconclusive; no significant effect was detected for any of the outcome measures. The aim of this study was to explore whether the programme theory for FitQuest was correct with respect to how and why it would change children's perceptions of physical activity (PA and exercise self-efficacy in the school setting. A further aim was to investigate the features of the school setting (context that may impact on FitQuest's implementation and effectiveness. Qualitative data (gathered during the RCT were gathered from interviews with teachers and children, and observation of sessions using FitQuest. Thematic analysis indicated that whilst children enjoyed playing the game, engaged with goal setting within the game context and undertook low to vigorous physical activity, there were significant contextual factors that prevented it from being played as often as intended. These included environmental factors (e.g. size of the playground, school factors (cancellations due to other activities, school technology policy (rules

  3. Understanding the Importance of Context: A Qualitative Study of a Location-Based Exergame to Enhance School Childrens Physical Activity.

    Science.gov (United States)

    Robertson, Judy; Jepson, Ruth; Macvean, Andrew; Gray, Stuart

    2016-01-01

    Many public health interventions are less effective than expected in 'real life settings', yet little work is undertaken to understand the reasons why. The effectiveness of complex public health interventions can often be traced back to a robust programme theory (how and why an intervention brings about a change in outcome(s)) and assumptions that are made about the context in which it is implemented. Understanding whether effectiveness (or lack thereof) is due to the intervention or the context is hugely helpful in decisions about whether to a) modify the intervention; b) modify the context; c) stop providing the intervention. Exergames-also known as Active Video Games or AVGS-are video games which use the player's bodily movements as input and have potential to increase physical activity in children. However, the results of a recent pilot randomised controlled trial (RCT) of a location-based exergame (FitQuest) in a school setting were inconclusive; no significant effect was detected for any of the outcome measures. The aim of this study was to explore whether the programme theory for FitQuest was correct with respect to how and why it would change children's perceptions of physical activity (PA) and exercise self-efficacy in the school setting. A further aim was to investigate the features of the school setting (context) that may impact on FitQuest's implementation and effectiveness. Qualitative data (gathered during the RCT) were gathered from interviews with teachers and children, and observation of sessions using FitQuest. Thematic analysis indicated that whilst children enjoyed playing the game, engaged with goal setting within the game context and undertook low to vigorous physical activity, there were significant contextual factors that prevented it from being played as often as intended. These included environmental factors (e.g. size of the playground), school factors (cancellations due to other activities), school technology policy (rules relating to

  4. Importance of early physical rehabilitation in improving functional state of vegetative nervous system of women with postmastectomy syndrome

    Directory of Open Access Journals (Sweden)

    Tatiana Odynets

    2016-02-01

    Full Text Available Purpose: to determine the expediency of early application of physical rehabilitation to improve the functional state of vegetative nervous system of women with postmastectomy syndrome. Material & Methods: theoretical analysis of scientific and methodical literature, analysis of heart rate variability, methods of mathematical statistics. The study involved 135 women with postmastectomy syndrome who underwent radical mastectomy for Madden. Results: at the end of the research value of high-frequency component of the spectrum was significantly higher in women MG1 compared to MG on 257,72 ms² (p<0,01 and the stress index was lower on 107,01 c. u (p<0,001. Conclusions: the feasibility of early rehabilitation intervention to improve the functional state of the autonomic nervous system is not detected during the year classes on problem-oriented programs.

  5. Why Social Relationships Are Important for Physical Health: A Systems Approach to Understanding and Modifying Risk and Protection.

    Science.gov (United States)

    Holt-Lunstad, Julianne

    2018-01-04

    Social relationships are adaptive and crucial for survival. This review presents existing evidence indicating that our social connections to others have powerful influences on health and longevity and that lacking social connection qualifies as a risk factor for premature mortality. A systems perspective is presented as a framework by which to move social connection into the realm of public health. Individuals, and health-relevant biological processes, exist within larger social contexts including the family, neighborhood and community, and society and culture. Applying the social ecological model, this review highlights the interrelationships of individuals within groups in terms of understanding both the causal mechanisms by which social connection influences physical health and the ways in which this influence can inform potential intervention strategies. A systems approach also helps identify gaps in our current understanding that may guide future research.

  6. Communication and context are important to Indigenous children with physical disability and their carers at a community-based physiotherapy service: a qualitative study

    Directory of Open Access Journals (Sweden)

    Caroline Greenstein

    2016-01-01

    Full Text Available Question: What are the experiences of Indigenous children with physical disability and their carers of their community-based physiotherapy service? What factors influence their experiences of the physiotherapy service and how could the service be improved? Design: A qualitative study using in-depth, semi-structured open-ended interviews consistent with the researchers’ interpretivist perspectives and ethical principles of Indigenous health research. Interviews were audio recorded, transcribed and coded for themes with qualitative research software using inductive analysis. The interviews were then checked for transcription accuracy and the themes were confirmed with the participants. Participants: Nine parents and foster carers of children with physical disability aged 0 to 21 years, five children and youth with physical disability aged 8 to 21 years. Results: The data generated three themes, which informed practice recommendations: carers of children with physical disability experience increased demands and complexity in their lives; relationships involving caring, consistency and communication are important to consumers using the physiotherapy service; and being Indigenous influences consumers’ experiences in ways that may not be obvious to non-Indigenous service providers. The issue of communication underpinned the participants’ experiences throughout these themes. Conclusion: The research highlighted the importance of effective communication, developing relationships, viewing the child wholistically and recognising the influence of being Indigenous on clients’ healthcare needs and experiences. The results suggested that community-based physiotherapists adopt a family/person-centred, context-specific approach when working with Indigenous children with a physical disability and their carers. [Greenstein C, Lowell A, Thomas D (2016 Communication and context are important to Indigenous children with physical disability and their carers

  7. PHYSICS

    CERN Multimedia

    Submitted by

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

  8. Non-Destructive Method by Gamma Sampling Measurements for Radiological Characterization of a Steam Generator: Physical and Numerical Modeling for ANIMMA (23-27 June 2013)

    International Nuclear Information System (INIS)

    Auge, G.; Rottner, B.; Dubois, C.

    2013-06-01

    The radiological characterization of a steam generator consists of evaluating the global radiological activity in the tube bundle. In this paper, we present a non-destructive method and the results analysis of the gamma sampling measurements from a sample of U-tubes in the bundle. On site, the implementation of the methodology is fairly easy. But the analysis of the results is more complicated due to the long path of the gamma ray (from 60 Co quite penetrating), and also the heterogeneous activity of U-tubes bundle, which have not the same life cycle. We explain why the periodic spatial arrangement complicates also the analysis. Furthermore, we have taken into account the environment of all tubes measured because of all the external influence activity of others U-tubes (the nearest, the most distant and potential hot spot). A great amount of independent influence coefficient had to be considered (roughly 18 million). Based on a physical and numerical modeling, and using a Cholesky algorithm solving the problem and saving time machine. (authors)

  9. Numerical relativity

    CERN Document Server

    Shibata, Masaru

    2016-01-01

    This book is composed of two parts: First part describes basics in numerical relativity, that is, the formulations and methods for a solution of Einstein's equation and general relativistic matter field equations. This part will be helpful for beginners of numerical relativity who would like to understand the content of numerical relativity and its background. The second part focuses on the application of numerical relativity. A wide variety of scientific numerical results are introduced focusing in particular on the merger of binary neutron stars and black holes.

  10. Massive pulmonary embolism: the predisposing and complicating factors, its current diagnostic approaches and critical importance of early diagnostic physical exam

    Directory of Open Access Journals (Sweden)

    Filip A. Konecny

    2006-12-01

    Full Text Available Massive pulmonary embolism (MPE often leads to circulation collapse, a form of shock. The process is set off by thrombus or multiple thrombi dislodgement followed by a rapid perfusion insufficiency of pulmonary arterial system. Patients experience severe hypotension with diastolic and systolic failure with an acute tricuspid regurgitation. On many occasions, release of an obstruction is unattainable and death is occurring frequently within one hour of presentation. A key reported source of MPE is its occurrence as a complication of deep vein thrombosis (DVT. While long-term immobilization and surgery are both directly associated with MPE, others such as previous DVT, malignancy, infectious lung and heart diseases, family thrombophilia, lower limb paralysis and pregnancy have to be considered as risk factors mainly due to its silent nature. Predisposing and complicating risks should be addressed by an early diagnostic physical exam. The clinician might offer a wide variety of diagnostic approaches, combining techniques into algorithms to better deal with the embolism severity. Multiple patient life-style changes and decisions to adhere to the proposed plan should be built up on patient-physician team effort. KEY WORDS: Massive pulmonary embolism, predisposing factors, current diagnostic approaches.

  11. Physical activity and cardiorespiratory fitness as major markers of cardiovascular risk: their independent and interwoven importance to health status.

    Science.gov (United States)

    Myers, Jonathan; McAuley, Paul; Lavie, Carl J; Despres, Jean-Pierre; Arena, Ross; Kokkinos, Peter

    2015-01-01

    The evolution from hunting and gathering to agriculture, followed by industrialization, has had a profound effect on human physical activity (PA) patterns. Current PA patterns are undoubtedly the lowest they have been in human history, with particularly marked declines in recent generations, and future projections indicate further declines around the globe. Non-communicable health problems that afflict current societies are fundamentally attributable to the fact that PA patterns are markedly different than those for which humans were genetically adapted. The advent of modern statistics and epidemiological methods has made it possible to quantify the independent effects of cardiorespiratory fitness (CRF) and PA on health outcomes. Based on more than five decades of epidemiological studies, it is now widely accepted that higher PA patterns and levels of CRF are associated with better health outcomes. This review will discuss the evidence supporting the premise that PA and CRF are independent risk factors for cardiovascular disease (CVD) as well as the interplay between both PA and CRF and other CVD risk factors. A particular focus will be given to the interplay between CRF, metabolic risk and obesity. Published by Elsevier Inc.

  12. 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...

  13. 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...

  14. Importance of sports during youth and exercise barriers in 20- to 29-year-old male nonathletes differently motivated for regular physical activities

    DEFF Research Database (Denmark)

    Leyk, Dieter; Witzki, Alexander; Sievert, Alexander

    2012-01-01

    The number of sedentary young adults has dramatically increased in past decades, and sedentary lifestyles are adopted at an increasingly earlier age. Little is known about barriers or predictors to (re)initiate regular physical activity in this group. The purpose of the study is to (a) identify...... subgroups in nonathletes differing in their amenability to physical exercise, (b) to analyze them for differences in barriers and intention to exercise, and (c) compare importance of sports during youth in nonathletes to trained peers. Using a health and fitness questionnaire 589 nonathletes were queried.......5%), the other groups showed significantly more barriers and a broader distribution. Similar characteristics but minor differences were observed for perceived importance of sports during youth. The most significant differences between athletes and nonathletes emerged enquiring the attitude and activity...

  15. PHYSICS

    CERN Multimedia

    J. Incandela

    The all-plenary format of the CMS week in Cyprus gave the opportunity to the conveners of the physics groups to present the plans of each physics analysis group for tackling early physics analyses. The presentations were complete, so all are encouraged to browse through them on the Web. There is a wealth of information on what is going on, by whom and on what basis and priority. The CMS week was followed by two CMS “physics events”, the ICHEP08 days and the physics days in July. These were two weeks dedicated to either the approval of all the results that would be presented at ICHEP08, or to the review of all the other Monte-Carlo based analyses that were carried out in the context of our preparations for analysis with the early LHC data (the so-called “2008 analyses”). All this was planned in the context of the beginning of a ramp down of these Monte Carlo efforts, in anticipation of data.  The ICHEP days are described below (agenda and talks at: http://indic...

  16. PHYSICS

    CERN Multimedia

    Joe Incandela

    There have been two plenary physics meetings since the December CMS week. The year started with two workshops, one on the measurements of the Standard Model necessary for “discovery physics” as well as one on the Physics Analysis Toolkit (PAT). Meanwhile the tail of the “2007 analyses” is going through the last steps of approval. It is expected that by the end of January all analyses will have converted to using the data from CSA07 – which include the effects of miscalibration and misalignment. January Physics Days The first Physics Days of 2008 took place on January 22-24. The first two days were devoted to comprehensive re¬ports from the Detector Performance Groups (DPG) and Physics Objects Groups (POG) on their planning and readiness for early data-taking followed by approvals of several recent studies. Highlights of POG presentations are included below while the activities of the DPGs are covered elsewhere in this bulletin. January 24th was devo...

  17. Importance of Physical and Physiological Parameters in Simulated Particle Transport in the Alveolar Zone of the Human Lung

    Directory of Open Access Journals (Sweden)

    Dogan Ciloglu

    2017-01-01

    Full Text Available The trajectory and deposition efficiency of micron-sized (1–5 µm particles, inhaled into the pulmonary system, are accurately determined with the aid of a newly developed model and modified simulation techniques. This alveolar model, which has a simple but physiologically appropriate geometry, and the utilized fluid structure interaction (FSI methods permit the precise simulation of tissue wall deformation and particle fluid interactions. The relation between tissue movement and airflow in the alveolated duct is solved by a two-way fluid structure interaction simulation technique, using ANSYS Workbench (Release 16.0, ANSYS INC., Pittsburgh, PA, USA, 2015. The dynamic transport of particles and their deposition are investigated as a function of aerodynamic particle size, tissue visco-elasticity, tidal breathing period, gravity orientation and particle–fluid interactions. It is found that the fluid flows and streamlines differ between the present flexible model and rigid models, and the two-way coupling particle trajectories vary relative to one-way particle coupling. In addition, the results indicate that modelling the two-way coupling particle system is important because the two-way discrete phase method (DPM approach despite its complexity provides more extensive particle interactions and is more reliable than transport results from the one-way DPM approach. The substantial difference between the results of the two approaches is likely due to particle–fluid interactions, which re-suspend the sediment particles in the airway stream and hence pass from the current generation.

  18. The importance of body satisfaction to physical self-concept and body mass index in Spanish adolescents.

    Science.gov (United States)

    Sánchez-Miguel, Pedro Antonio; González, Juan José Pulido; Sánchez-Oliva, David; Alonso, Diana Amado; Leo, Francisco Miguel

    2018-04-06

    This research examines the association between measured body mass index (BMI) and the perception of BMI by young students. Moreover, this research tests the importance of BMI and self-concept, in order to predict body dissatisfaction in high school students. The sample consisted of 2087 individuals from different high schools in Extremadura, Spain, both males (n = 1046) and females (n = 1041), ranging in age from 15 to 17 years old (M = 15.42; SD = 0.86). Initially, participants' BMIs were assessed through anthropometry. Later, all individuals were asked about their weight and height, and their self-reported BMI was calculated. Participants also answered a questionnaire about their perception of self-concept, as well as completed a test about body image perception using Stunkard images. Outcomes revealed that factors concerning self-concept and perceived BMI explained body dissatisfaction. Finally, results are discussed with the aim of improving knowledge in body dissatisfaction context. © 2018 International Union of Psychological Science.

  19. 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.

  20. Radiation transport in numerical astrophysics

    International Nuclear Information System (INIS)

    Lund, C.M.

    1983-02-01

    In this article, we discuss some of the numerical techniques developed by Jim Wilson and co-workers for the calculation of time-dependent radiation flow. Difference equations for multifrequency transport are given for both a discrete-angle representation of radiation transport and a Fick's law-like representation. These methods have the important property that they correctly describe both the streaming and diffusion limits of transport theory in problems where the mean free path divided by characteristic distances varies from much less than one to much greater than one. They are also stable for timesteps comparable to the changes in physical variables, rather than being limited by stability requirements

  1. Communication and context are important to Indigenous children with physical disability and their carers at a community-based physiotherapy service: a qualitative study.

    Science.gov (United States)

    Greenstein, Caroline; Lowell, Anne; Thomas, David

    2016-01-01

    What are the experiences of Indigenous children with physical disability and their carers of their community-based physiotherapy service? What factors influence their experiences of the physiotherapy service and how could the service be improved? A qualitative study using in-depth, semi-structured open-ended interviews consistent with the researchers' interpretivist perspectives and ethical principles of Indigenous health research. Interviews were audio recorded, transcribed and coded for themes with qualitative research software using inductive analysis. The interviews were then checked for transcription accuracy and the themes were confirmed with the participants. Nine parents and foster carers of children with physical disability aged 0 to 21 years, five children and youth with physical disability aged 8 to 21 years. The data generated three themes, which informed practice recommendations: carers of children with physical disability experience increased demands and complexity in their lives; relationships involving caring, consistency and communication are important to consumers using the physiotherapy service; and being Indigenous influences consumers' experiences in ways that may not be obvious to non-Indigenous service providers. The issue of communication underpinned the participants' experiences throughout these themes. The research highlighted the importance of effective communication, developing relationships, viewing the child wholistically and recognising the influence of being Indigenous on clients' healthcare needs and experiences. The results suggested that community-based physiotherapists adopt a family/person-centred, context-specific approach when working with Indigenous children with a physical disability and their carers. Copyright © 2015 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

  2. Importance of climate change-physical forcing on the increase of cyanobacterial blooms in a small, stratified lake

    Directory of Open Access Journals (Sweden)

    Dolores Planas

    2016-03-01

    strong westerly wind gust events (~5 to >12 m s-1 induced large amplitude internal waves (mainly V2H1 mode that vertically displaced the isotherms by more than 3.5 m. During this event the top of the metalimnetic algal peak was entrained through the epilimnion, bringing metalimnetic Plankthotrix spp. to the lake surface, modified the deep metalimnion and hypolimnion concentrations of dissolved oxygen, and caused an upsurge in phosphorus. We conclude that algal and nutrient upwelling linked to intermittent deep mixing events, play an important role in supporting summer cyanobacterial blooms in lake Bromont.

  3. Numerical analysis of bifurcations

    International Nuclear Information System (INIS)

    Guckenheimer, J.

    1996-01-01

    This paper is a brief survey of numerical methods for computing bifurcations of generic families of dynamical systems. Emphasis is placed upon algorithms that reflect the structure of the underlying mathematical theory while retaining numerical efficiency. Significant improvements in the computational analysis of dynamical systems are to be expected from more reliance of geometric insight coming from dynamical systems theory. copyright 1996 American Institute of Physics

  4. Mitigation of numerical noise for beam loss simulations

    CERN Document Server

    Kesting, Frederik

    2017-01-01

    Numerical noise emerges in self-consistent simulations of charged particles, and its mitigation is investigated since the first numerical studies in plasma physics. In accelerator physics, recent studies find an artificial diffusion of the particle beam due to numerical noise in particle-in-cell tracking, which is of particular importance for high intensity machines with a long storage time, as the SIS100 at FAIR or in context of the LIU upgrade at CERN. In beam loss simulations for these projects artificial effects must be distinguished from physical beam loss. Therefore, it is important to relate artificial diffusion to artificial beam loss, and to choose simulation parameters such that physical beam loss is well resolved. As a practical tool, we therefore suggest a scaling law to find optimal simulation parameters for a given maximum percentage of acceptable artificial beam loss.

  5. 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...

  6. 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...

  7. Numerical Development

    Science.gov (United States)

    Siegler, Robert S.; Braithwaite, David W.

    2016-01-01

    In this review, we attempt to integrate two crucial aspects of numerical development: learning the magnitudes of individual numbers and learning arithmetic. Numerical magnitude development involves gaining increasingly precise knowledge of increasing ranges and types of numbers: from non-symbolic to small symbolic numbers, from smaller to larger…

  8. Hindi Numerals.

    Science.gov (United States)

    Bright, William

    In most languages encountered by linguists, the numerals, considered as a paradigmatic set, constitute a morpho-syntactic problem of only moderate complexity. The Indo-Aryan language family of North India, however, presents a curious contrast. The relatively regular numeral system of Sanskrit, as it has developed historically into the modern…

  9. Numerical analysis

    CERN Document Server

    Rao, G Shanker

    2006-01-01

    About the Book: This book provides an introduction to Numerical Analysis for the students of Mathematics and Engineering. The book is designed in accordance with the common core syllabus of Numerical Analysis of Universities of Andhra Pradesh and also the syllabus prescribed in most of the Indian Universities. Salient features: Approximate and Numerical Solutions of Algebraic and Transcendental Equation Interpolation of Functions Numerical Differentiation and Integration and Numerical Solution of Ordinary Differential Equations The last three chapters deal with Curve Fitting, Eigen Values and Eigen Vectors of a Matrix and Regression Analysis. Each chapter is supplemented with a number of worked-out examples as well as number of problems to be solved by the students. This would help in the better understanding of the subject. Contents: Errors Solution of Algebraic and Transcendental Equations Finite Differences Interpolation with Equal Intervals Interpolation with Unequal Int...

  10. The importance of Thermo-Hydro-Mechanical couplings and microstructure to strain localization in 3D continua with application to seismic faults. Part II: Numerical implementation and post-bifurcation analysis

    Science.gov (United States)

    Rattez, Hadrien; Stefanou, Ioannis; Sulem, Jean; Veveakis, Manolis; Poulet, Thomas

    2018-06-01

    In this paper we study the phenomenon of localization of deformation in fault gouges during seismic slip. This process is of key importance to understand frictional heating and energy budget during an earthquake. A infinite layer of fault gouge is modeled as a Cosserat continuum taking into account Thermo-Hydro-Mechanical (THM) couplings. The theoretical aspects of the problem are presented in the companion paper (Rattez et al., 2017a), together with a linear stability analysis to determine the conditions of localization and estimate the shear band thickness. In this Part II of the study, we investigate the post-bifurcation evolution of the system by integrating numerically the full system of non-linear equations using the method of Finite Elements. The problem is formulated in the framework of Cosserat theory. It enables to introduce information about the microstructure of the material in the constitutive equations and to regularize the mathematical problem in the post-localization regime. We emphasize the influence of the size of the microstructure and of the softening law on the material response and the strain localization process. The weakening effect of pore fluid thermal pressurization induced by shear heating is examined and quantified. It enhances the weakening process and contributes to the narrowing of shear band thickness. Moreover, due to THM couplings an apparent rate-dependency is observed, even for rate-independent material behavior. Finally, comparisons show that when the perturbed field of shear deformation dominates, the estimation of the shear band thickness obtained from linear stability analysis differs from the one obtained from the finite element computations, demonstrating the importance of post-localization numerical simulations.

  11. Numerical methods using Matlab

    CERN Document Server

    Lindfield, George

    2012-01-01

    Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of useful and important numerical algorithms that can be implemented into MATLAB for a graphical interpretation to help researchers analyze a particular outcome. Many worked examples are given together with exercises and solutions to illustrate how numerical methods can be used to study problems that have applications in the biosciences, chaos, optimization, engineering and science across the board. Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of use

  12. 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...

  13. 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 ...

  14. PHYSICS

    CERN Multimedia

    L. Demortier

    Physics-wise, the CMS week in December was dominated by discussions of the analyses that will be carried out in the “next six months”, i.e. while waiting for the first LHC collisions.  As presented in December, analysis approvals based on Monte Carlo simulation were re-opened, with the caveat that for this work to be helpful to the goals of CMS, it should be carried out using the new software (CMSSW_2_X) and associated samples.  By the end of the week, the goal for the physics groups was set to be the porting of our physics commissioning methods and plans, as well as the early analyses (based an integrated luminosity in the range 10-100pb-1) into this new software. Since December, the large data samples from CMSSW_2_1 were completed. A big effort by the production group gave a significant number of events over the end-of-year break – but also gave out the first samples with the fast simulation. Meanwhile, as mentioned in December, the arrival of 2_2 meant that ...

  15. 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 ...

  16. PHYSICS

    CERN Document Server

    C. Hill

    2012-01-01

      The period since the last CMS Bulletin has been historic for CMS Physics. The pinnacle of our physics programme was an observation of a new particle – a strong candidate for a Higgs boson – which has captured worldwide interest and made a profound impact on the very field of particle physics. At the time of the discovery announcement on 4 July, 2012, prominent signals were observed in the high-resolution H→γγ and H→ZZ(4l) modes. Corroborating excess was observed in the H→W+W– mode as well. The fermionic channel analyses (H→bb, H→ττ), however, yielded less than the Standard Model (SM) expectation. Collectively, the five channels established the signal with a significance of five standard deviations. With the exception of the diphoton channel, these analyses have all been updated in the last months and several new channels have been added. With improved analyses and more than twice the i...

  17. Important considerations for feasibility studies in physical activity research involving persons with multiple sclerosis: a scoping systematic review and case study.

    Science.gov (United States)

    Learmonth, Yvonne C; Motl, Robert W

    2018-01-01

    Much research has been undertaken to establish the important benefits of physical activity in persons with multiple sclerosis (MS). There is disagreement regarding the strength of this research, perhaps because the majority of studies on physical activity and its benefits have not undergone initial and systematic feasibility testing. We aim to address the feasibility processes that have been examined within the context of physical activity interventions in MS. A systematic scoping review was conducted based on a literature search of five databases to identify feasibility processes described in preliminary studies of physical activity in MS. We read and extracted methodology from each study based on the following feasibility metrics: process (e.g. recruitment), resource (e.g. monetary costs), management (e.g. personnel time requirements) and scientific outcomes (e.g. clinical/participant reported outcome measures). We illustrate the use of the four feasibility metrics within a randomised controlled trial of a home-based exercise intervention in persons with MS. Twenty-five studies were identified. Resource feasibility (e.g. time and resources) and scientific outcomes feasibility (e.g. clinical outcomes) methodologies were applied and described in many studies; however, these metrics have not been systematically addressed. Metrics related to process feasibility (e.g. recruitment) and management feasibility (e.g. human and data management) are not well described within the literature. Our case study successfully enabled us to address the four feasibility metrics, and we provide new information on management feasibility (i.e. estimate data completeness and estimate data entry) and scientific outcomes feasibility (i.e. determining data collection materials appropriateness). Our review highlights the existing research and provides a case study which assesses important metrics of study feasibility. This review serves as a clarion call for feasibility trials that will

  18. Numerical analysis

    CERN Document Server

    Scott, L Ridgway

    2011-01-01

    Computational science is fundamentally changing how technological questions are addressed. The design of aircraft, automobiles, and even racing sailboats is now done by computational simulation. The mathematical foundation of this new approach is numerical analysis, which studies algorithms for computing expressions defined with real numbers. Emphasizing the theory behind the computation, this book provides a rigorous and self-contained introduction to numerical analysis and presents the advanced mathematics that underpin industrial software, including complete details that are missing from most textbooks. Using an inquiry-based learning approach, Numerical Analysis is written in a narrative style, provides historical background, and includes many of the proofs and technical details in exercises. Students will be able to go beyond an elementary understanding of numerical simulation and develop deep insights into the foundations of the subject. They will no longer have to accept the mathematical gaps that ex...

  19. The Importance of Exercise in the Well-Rounded Physician: Dialogue for the Inclusion of a Physical Fitness Program in Neurosurgery Resident Training.

    Science.gov (United States)

    Fargen, Kyle M; Spiotta, Alejandro M; Turner, Raymond D; Patel, Sunil

    2016-06-01

    Exercise, diet, and personal fitness programs are essentially lacking in modern graduate medical education. In the context of long hours and alternating shift and sleep cycles, the lack of exercise and poor dietary choices may have negative consequences on physician physical and mental health. This opinion piece aims to generate important dialogue regarding the scope of the problem, the literature supporting the health benefits of exercise, potential solutions to enhancing diet and exercise among resident trainees, and possible pitfalls to the adoption of exercise programs within graduate medical education. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Importance of characteristics and modalities of physical activity and exercise in the management of cardiovascular health in individuals with cardiovascular disease (Part III)

    DEFF Research Database (Denmark)

    Vanhees, L; Rauch, B; Piepoli, M

    2012-01-01

    . However, it remains largely obscure, which characteristics of physical activity (PA) and exercise training--frequency, intensity, time (duration), type (mode), and volume (dose: intensity x duration) of exercise--are the most effective. The present paper, therefore, will deal with these exercise...... Association on Cardiovascular Prevention and Rehabilitation are formulated regarding frequency, intensity, time and type of PA, and safety aspects during exercise inpatients with cardiovascular disease. This paper is the third in a series of three papers, all devoted to the same theme: the importance...

  1. Importance of characteristics and modalities of physical activity and exercise in defining the benefits to cardiovascular health within the general population

    DEFF Research Database (Denmark)

    Vanhees, L; De Sutter, J; GeladaS, N

    2012-01-01

    Over the last decades, more and more evidence is accumulated that physical activity (PA) and exercise interventions are essential components in primary and secondary prevention for cardiovascular disease. However, it is less clear whether and which type of PA and exercise intervention (aerobic...... exercise, dynamic resistive exercise, or both) or characteristic of exercise (frequency, intensity, time or duration, and volume) would yield more benefit in achieving cardiovascular health. The present paper, as the first of a series of three, will make specific recommendations on the importance...

  2. 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...

  3. 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...

  4. PHYSICS

    CERN Multimedia

    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...

  5. Importance of physical health and health-behaviors in adolescence for risk of dropout from secondary education in young adulthood: an 8-year prospective study.

    Science.gov (United States)

    Svansdottir, Erla; Arngrimsson, Sigurbjorn A; Sveinsson, Thorarinn; Johannsson, Erlingur

    2015-11-24

    Education and health constitute two interlinked assets that are highly important to individuals. In Iceland, prevalence of dropout from secondary education poses a considerable problem. This 8-year prospective study assesses to what extent poor physical health and negative health-behaviors of Icelandic adolescents predict increased odds of dropout from secondary education. The sample included n = 201 Icelandic children who participated at age 15 (baseline) and again at age 23 (follow-up). Data included objective measurements of physical health and questionnaires assessing health-behaviors, education status, parental education, neighborhood characteristics, self-esteem, and depression. Independent t-tests and chi-square were used to assess differences in physical health and health-behaviors at follow-up stratified by education status. Ordinal regression models were conducted to assess whether physical health and health-behaviors at age 15 predicted increased odds of dropout from secondary education at age 23, independent of gender, parental education and psychological factors. At age 23, 78 % of girls and 71 % of boys had completed a secondary education. Completion of a secondary education was associated with significant health benefits, especially among women. Women without a secondary education had lower fitness, more somatic complaints, higher diastolic blood pressure, less sports participation, and poorer sleep, whilst men without a secondary education watched more television. In logistic regression models somatic complaints during adolescence were associated with 1.09 (95 % CI: 1.02-1.18) higher odds of dropout from secondary education in young adulthood, independent of covariates. Health-behaviors associated with higher dropout odds included smoking (3.67, 95 % CI: 1.50-9.00), alcohol drinking (2.57, 95 % CI: 1.15-5.75), and time spent watching television (1.27, 95 % CI:1.03-1.56), which were independent of most covariates. Finally, mother's higher

  6. Physics of Intrinsic and Extrinsic Factors that Cause the Onset of the Deadliest Illness of Mankind and are Important for Diagnostics and Treatment

    Science.gov (United States)

    Saxena, Arjun

    One of the most important topic of research in the field of Physics of Behavior is the deadliest illness of mankind which is the group of illnesses called mental illnesses. They are getting attention increasingly worldwide by the medical communities and their respective governments, because of the following fact. It is now well established that these illnesses cause more loss of human lives, destruction of families, businesses and overall economy than all the other illnesses combined. The purpose of this paper is to identify and provide solutions to two fundamental issues of such illnesses which still remain as problems. One is the stigma associated with them because of their name ``mental''. The patients are regarded as less than normal because their illness is only ``mental'' in origin. The second is that it is still not widely recognized that they are caused by medical problems in their ``brain'' which afflict their ``mind''. This paper explains this and gives an improved 3-D model using the physics of intrinsic and extrinsic factors of both ``brain'' and ``mind''. It leads to an important new name, ``BAMI'' (Brain and Mind Illness), which eliminates the stigma and gives quantitative parameters to diagnose the illness and monitor medicines to treat such illnesses.

  7. Importance of sports during youth and exercise barriers in 20- to 29-year-old male nonathletes differently motivated for regular physical activities.

    Science.gov (United States)

    Leyk, Dieter; Witzki, Alexander; Sievert, Alexander; Rohde, Ulrich; Moedl, Anne; Rüther, Thomas; Löllgen, Herbert; Hackfort, Dieter

    2012-07-01

    The number of sedentary young adults has dramatically increased in past decades, and sedentary lifestyles are adopted at an increasingly earlier age. Little is known about barriers or predictors to (re)initiate regular physical activity in this group. The purpose of the study is to (a) identify subgroups in nonathletes differing in their amenability to physical exercise, (b) to analyze them for differences in barriers and intention to exercise, and (c) compare importance of sports during youth in nonathletes to trained peers. Using a health and fitness questionnaire 589 nonathletes were queried in the cross-sectional survey and compared with 270 trained peers. Athletic abstainers (A), lower (L), and higher (H) motivated nonathletes were separated based on previous engagement in sports. Of the nonathletes, 54.7% reported only 1 barrier to exercise. Although this feature was most prominent in H (71.5%), the other groups showed significantly more barriers and a broader distribution. Similar characteristics but minor differences were observed for perceived importance of sports during youth. The most significant differences between athletes and nonathletes emerged enquiring the attitude and activity of the parents. The majority of nonathletes (72.8%) indicate their intention to exercise in the future. Their intention differed significantly in H (88.1%), L (76.1%), and A (59.1%). However, there are good reasons to doubt that most of those intending nonathletes will actually become physically active. Even in the analyzed narrow age range of men different motivated groups of nonathletes were found. Because of the differences in receptiveness and approachability health promotion policies may not only consider the often recommended tailored interventions but also carefully designed incentive programs.

  8. Computational physics an introduction

    CERN Document Server

    Vesely, Franz J

    1994-01-01

    Author Franz J. Vesely offers students an introductory text on computational physics, providing them with the important basic numerical/computational techniques. His unique text sets itself apart from others by focusing on specific problems of computational physics. The author also provides a selection of modern fields of research. Students will benefit from the appendixes which offer a short description of some properties of computing and machines and outline the technique of 'Fast Fourier Transformation.'

  9. Numerical analysis

    CERN Document Server

    Brezinski, C

    2012-01-01

    Numerical analysis has witnessed many significant developments in the 20th century. This book brings together 16 papers dealing with historical developments, survey papers and papers on recent trends in selected areas of numerical analysis, such as: approximation and interpolation, solution of linear systems and eigenvalue problems, iterative methods, quadrature rules, solution of ordinary-, partial- and integral equations. The papers are reprinted from the 7-volume project of the Journal of Computational and Applied Mathematics on '/homepage/sac/cam/na2000/index.html<

  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. Numerical modelling of physical processes in a ballistic laboratory setup with a tapered adapter and plastic piston used for obtaining high muzzle velocities

    Science.gov (United States)

    Bykov, N. V.

    2014-12-01

    Numerical modelling of a ballistic setup with a tapered adapter and plastic piston is considered. The processes in the firing chamber are described within the framework of quasi- one-dimensional gas dynamics and a geometrical law of propellant burn by means of Lagrangian mass coordinates. The deformable piston is considered to be an ideal liquid with specific equations of state. The numerical solution is obtained by means of a modified explicit von Neumann scheme. The calculation results given show that the ballistic setup with a tapered adapter and plastic piston produces increased shell muzzle velocities by a factor of more than 1.5-2.

  12. The effects of chemical and physical factors on mammalian embryo culture and their importance for the practice of assisted human reproduction.

    Science.gov (United States)

    Wale, Petra L; Gardner, David K

    2016-01-01

    Although laboratory procedures, along with culture media formulations, have improved over the past two decades, the issue remains that human IVF is performed in vitro (literally 'in glass'). Using PubMed, electronic searches were performed using keywords from a list of chemical and physical factors with no limits placed on time. Examples of keywords include oxygen, ammonium, volatile organics, temperature, pH, oil overlays and incubation volume/embryo density. Available clinical and scientific evidence surrounding physical and chemical factors have been assessed and presented here. Development of the embryo outside the body means that it is constantly exposed to stresses that it would not experience in vivo. Sources of stress on the human embryo include identified factors such as pH and temperature shifts, exposure to atmospheric (20%) oxygen and the build-up of toxins in the media due to the static nature of culture. However, there are other sources of stress not typically considered, such as the act of pipetting itself, or the release of organic compounds from the very tissue culture ware upon which the embryo develops. Further, when more than one stress is present in the laboratory, there is evidence that negative synergies can result, culminating in significant trauma to the developing embryo. It is evident that embryos are sensitive to both chemical and physical signals within their microenvironment, and that these factors play a significant role in influencing development and events post transfer. From the viewpoint of assisted human reproduction, a major concern with chemical and physical factors lies in their adverse effects on the viability of embryos, and their long-term effects on the fetus, even as a result of a relatively brief exposure. This review presents data on the adverse effects of chemical and physical factors on mammalian embryos and the importance of identifying, and thereby minimizing, them in the practice of human IVF. Hence, optimizing the

  13. Numerical Relativity

    Science.gov (United States)

    Baker, John G.

    2009-01-01

    Recent advances in numerical relativity have fueled an explosion of progress in understanding the predictions of Einstein's theory of gravity, General Relativity, for the strong field dynamics, the gravitational radiation wave forms, and consequently the state of the remnant produced from the merger of compact binary objects. I will review recent results from the field, focusing on mergers of two black holes.

  14. Factors affecting the physical and mental health of older adults in China: The importance of marital status, child proximity, and gender

    Directory of Open Access Journals (Sweden)

    Lindy Williams

    2017-12-01

    Full Text Available Evidence is accumulating about the association between strong family ties and the emotional and physical welfare of older adults, and researchers have identified negative consequences of being unmarried, being childless, and/or living alone. These associations have been recognized in multiple contexts, including in Asia where living with a spouse and/or grown children has been shown in some studies to improve elderly well-being. Social support, especially family support, is expected to continue to be important where populations are aging and social safety nets are weak. Using longitudinal data from the 2010 and 2012 waves of the China Family Panel Studies, we focus on the effects of marital status at times 1 and 2, changes in marital status between the two surveys, and other family-related indicators of social connectedness on ratings of depression, levels of life satisfaction, and self-reported physical health among those aged 50 and over. Our sample includes 9831 respondents who have valid data on wellbeing indicators for Wave 1 and Wave 2, as well as complete information on the other covariates controlled in our analysis. In analyses of the full sample, those who were married at both points in time reported lower depression scores than those who were never-married, divorced, or widowed at both time points, and those whose unions dissolved in the interval. Those who were married at both times also generally reported greater levels of life satisfaction than those who were never married at both time points and those who became divorced during the interval. Important underlying gender differences are observed both for life satisfaction and depression. In addition, those who were married at both time points reported being in better physical health than those who became widowed during the interval (significant primarily for women, and those who had never been married (significant primarily for men. Our study contributes to the literature on social

  15. Factors affecting the physical and mental health of older adults in China: The importance of marital status, child proximity, and gender.

    Science.gov (United States)

    Williams, Lindy; Zhang, Renling; Packard, Kevin C

    2017-12-01

    Evidence is accumulating about the association between strong family ties and the emotional and physical welfare of older adults, and researchers have identified negative consequences of being unmarried, being childless, and/or living alone. These associations have been recognized in multiple contexts, including in Asia where living with a spouse and/or grown children has been shown in some studies to improve elderly well-being. Social support, especially family support, is expected to continue to be important where populations are aging and social safety nets are weak. Using longitudinal data from the 2010 and 2012 waves of the China Family Panel Studies, we focus on the effects of marital status at times 1 and 2, changes in marital status between the two surveys, and other family-related indicators of social connectedness on ratings of depression, levels of life satisfaction, and self-reported physical health among those aged 50 and over. Our sample includes 9831 respondents who have valid data on wellbeing indicators for Wave 1 and Wave 2, as well as complete information on the other covariates controlled in our analysis. In analyses of the full sample, those who were married at both points in time reported lower depression scores than those who were never-married, divorced, or widowed at both time points, and those whose unions dissolved in the interval. Those who were married at both times also generally reported greater levels of life satisfaction than those who were never married at both time points and those who became divorced during the interval. Important underlying gender differences are observed both for life satisfaction and depression. In addition, those who were married at both time points reported being in better physical health than those who became widowed during the interval (significant primarily for women), and those who had never been married (significant primarily for men). Our study contributes to the literature on social ties and the

  16. SCAPIS Pilot Study: Sitness, Fitness and Fatness - Is Sedentary Time Substitution by Physical Activity Equally Important for Everyone's Markers of Glucose Regulation?

    Science.gov (United States)

    Ekblom-Bak, Elin; Ekblom, Örjan; Bolam, Kate A; Ekblom, Björn; Bergström, Göran; Börjesson, Mats

    2016-07-01

    Although moderate-to-vigorous physical activity (MVPA) is mainly recommended for glucose control, light physical activity (LIPA) may also have the potential to induce favorable changes. We investigated sedentary time (SED) substitution with equal time in LIPA and MVPA, and the association with markers of glucose regulation and insulin sensitivity after stratification by waist circumference, fitness and fasting glucose levels. A total of 654 men and women, 50 to 64 years, from the SCAPIS pilot study were included. Daily SED, LIPA and MVPA were assessed using hip-worn accelerometers. Fasting plasma glucose, insulin and HOMA-IR were determined. Substituting 30 min of SED with LIPA was significantly associated with 3.0% lower fasting insulin values and 3.1% lower HOMA-IR values, with even lower levels when substituting SED with MVPA. Participants with lower fitness and participants with high fasting glucose levels benefited significantly more from substituting 30 min of SED with LIPA compared with participants with normal to high fitness levels and participants with normal glucose levels, respectively. LIPA, and not only MVPA, may have beneficial associations with glucose regulation. This is of great clinical and public health importance, not least because it may confer a higher compliance rate to regular PA.

  17. Importance of characteristics and modalities of physical activity and exercise in defining the benefits to cardiovascular health within the general population: recommendations from the EACPR (Part I).

    Science.gov (United States)

    Vanhees, L; De Sutter, J; GeladaS, N; Doyle, F; Prescott, E; Cornelissen, V; Kouidi, E; Dugmore, D; Vanuzzo, D; Börjesson, M; Doherty, P

    2012-08-01

    Over the last decades, more and more evidence is accumulated that physical activity (PA) and exercise interventions are essential components in primary and secondary prevention for cardiovascular disease. However, it is less clear whether and which type of PA and exercise intervention (aerobic exercise, dynamic resistive exercise, or both) or characteristic of exercise (frequency, intensity, time or duration, and volume) would yield more benefit in achieving cardiovascular health. The present paper, as the first of a series of three, will make specific recommendations on the importance of these characteristics for cardiovascular health in the population at large. The guidance offered in this series of papers is aimed at medical doctors, health practitioners, kinesiologists, physiotherapists and exercise physiologists, politicians, public health policy makers, and the individual member of the public. Based on previous and the current literature, recommendations from the European Association on Cardiovascular Prevention and Rehabilitation are formulated regarding type, volume, and intensity of PA and exercise.

  18. On numerical Bessel transformation

    International Nuclear Information System (INIS)

    Sommer, B.; Zabolitzky, J.G.

    1979-01-01

    The authors present a computer program to calculate the three dimensional Fourier or Bessel transforms and definite integrals with Bessel functions. Numerical integration of systems containing Bessel functions occurs in many physical problems, e.g. electromagnetic form factor of nuclei, all transitions involving multipole expansions at high momenta. Filon's integration rule is extended to spherical Bessel functions. The numerical error is of the order of the Simpson error term of the function which has to be transformed. Thus one gets a stable integral even at large arguments of the transformed function. (Auth.)

  19. Numerical relativity

    CERN Document Server

    Nakamura, T

    1993-01-01

    In GR13 we heard many reports on recent. progress as well as future plans of detection of gravitational waves. According to these reports (see the report of the workshop on the detection of gravitational waves by Paik in this volume), it is highly probable that the sensitivity of detectors such as laser interferometers and ultra low temperature resonant bars will reach the level of h ~ 10—21 by 1998. in this level we may expect the detection of the gravitational waves from astrophysical sources such as coalescing binary neutron stars once a year or so. Therefore the progress in numerical relativity is urgently required to predict the wave pattern and amplitude of the gravitational waves from realistic astrophysical sources. The time left for numerical relativists is only six years or so although there are so many difficulties in principle as well as in practice.

  20. Project Fog Drops 5. Task 1: A numerical model of advection fog. Task 2: Recommendations for simplified individual zero-gravity cloud physics experiments

    Science.gov (United States)

    Rogers, C. W.; Eadie, W. J.; Katz, U.; Kocmond, W. C.

    1975-01-01

    A two-dimensional numerical model was used to investigate the formation of marine advection fog. The model predicts the evolution of potential temperature, horizontal wind, water vapor content, and liquid water content in a vertical cross section of the atmosphere as determined by vertical turbulent transfer and horizontal advection, as well as radiative cooling and drop sedimentation. The model is designed to simulate the formation, development, or dissipation of advection fog in response to transfer of heat and moisture between the atmosphere and the surface as driven by advection over horizontal discontinuities in the surface temperature. Results from numerical simulations of advection fog formation are discussed with reference to observations of marine fog. A survey of candidate fog or cloud microphysics experiments which might be performed in the low gravity environment of a shuttle-type spacecraft in presented. Recommendations are given for relatively simple experiments which are relevent to fog modification problems.

  1. Integral and differential methods for the numerical solution of 2-D field problems in high energy physics magnets and electrical machines

    International Nuclear Information System (INIS)

    Hannalla, A.Y.; Simkin, J.; Trowbridge, C.W.

    1979-10-01

    Numerical calculations of electromagnetic fields have been performed by solving integral or differential equations. Integral methods are ideally suited to open boundary problems and on the other hand the geometric complexity of electrical machines makes differential methods more attractive. In this paper both integral and differential equation methods are reviewed, and the limitations of the methods are highlighted, in an attempt to show how to select the best method for a particular problem. (author)

  2. Medical physics in radiotherapy: The importance of preserving clinical responsibilities and expanding the profession's role in research, education, and quality control.

    Science.gov (United States)

    Malicki, Julian

    2015-01-01

    Medical physicists have long had an integral role in radiotherapy. In recent decades, medical physicists have slowly but surely stepped back from direct clinical responsibilities in planning radiotherapy treatments while medical dosimetrists have assumed more responsibility. In this article, I argue against this gradual withdrawal from routine therapy planning. It is essential that physicists be involved, at least to some extent, in treatment planning and clinical dosimetry for each and every patient; otherwise, physicists can no longer be considered clinical specialists. More importantly, this withdrawal could negatively impact treatment quality and patient safety. Medical physicists must have a sound understanding of human anatomy and physiology in order to be competent partners to radiation oncologists. In addition, they must possess a thorough knowledge of the physics of radiation as it interacts with body tissues, and also understand the limitations of the algorithms used in radiotherapy. Medical physicists should also take the lead in evaluating emerging challenges in quality and safety of radiotherapy. In this sense, the input of physicists in clinical audits and risk assessment is crucial. The way forward is to proactively take the necessary steps to maintain and advance our important role in clinical medicine.

  3. Medical physics in radiotherapy: The importance of preserving clinical responsibilities and expanding the profession's role in research, education, and quality control

    Science.gov (United States)

    Malicki, Julian

    2015-01-01

    Medical physicists have long had an integral role in radiotherapy. In recent decades, medical physicists have slowly but surely stepped back from direct clinical responsibilities in planning radiotherapy treatments while medical dosimetrists have assumed more responsibility. In this article, I argue against this gradual withdrawal from routine therapy planning. It is essential that physicists be involved, at least to some extent, in treatment planning and clinical dosimetry for each and every patient; otherwise, physicists can no longer be considered clinical specialists. More importantly, this withdrawal could negatively impact treatment quality and patient safety. Medical physicists must have a sound understanding of human anatomy and physiology in order to be competent partners to radiation oncologists. In addition, they must possess a thorough knowledge of the physics of radiation as it interacts with body tissues, and also understand the limitations of the algorithms used in radiotherapy. Medical physicists should also take the lead in evaluating emerging challenges in quality and safety of radiotherapy. In this sense, the input of physicists in clinical audits and risk assessment is crucial. The way forward is to proactively take the necessary steps to maintain and advance our important role in clinical medicine. PMID:25949219

  4. Numerical Gram-Schmidt orthonormalization

    International Nuclear Information System (INIS)

    Werneth, Charles M; Dhar, Mallika; Maung, Khin Maung; Sirola, Christopher; Norbury, John W

    2010-01-01

    A numerical Gram-Schmidt orthonormalization procedure is presented for constructing an orthonormal basis function set from a non-orthonormal set, when the number of basis functions is large. This method will provide a pedagogical illustration of the Gram-Schmidt procedure and can be presented in classes on numerical methods or computational physics.

  5. Physical and numerical modeling of multidimensional liquid-vapor flows advanced two-fluid models, application to upwind finite volume methods

    International Nuclear Information System (INIS)

    Seignole, V.

    2005-01-01

    This report presents the work of thesis realized under the direction of Jean-Michel Ghidaglia (thesis director, ENS-Cachan) and of Anela Kumbaro (tutor, CEA) within the framework of the modeling of two-phase flows with OAP code. The report consists of two parts of unequal size: the first part concentrates on aspects related exclusively to two-phase flows, while the second one is devoted to the study of a numerical problem inherent to the resolution of two-phase flow systems, but whose action has a broader framework. (author)

  6. Evidence for a trade-off strategy in stone oak (Lithocarpus seeds between physical and chemical defense highlights fiber as an important antifeedant.

    Directory of Open Access Journals (Sweden)

    Xi Chen

    Full Text Available Trees in the beech or oak family (Fagaceae have a mutualistic relationship with scatter-hoarding rodents. Rodents obtain nutrients and energy by consuming seeds, while providing seed dispersal for the tree by allowing some cached seeds to germinate. Seed predation and caching behavior of rodents is primarily affected by seed size, mechanical protection, macronutrient content, and chemical antifeedants. To enhance seed dispersal, trees must optimize trade-offs in investment between macronutrients and antifeedants. Here, we examine this important chemical balance in the seeds of tropical stone oak species with two substantially different fruit morphologies. These two distinct fruit morphologies in Lithocarpus differ in the degree of mechanical protection of the seed. For 'acorn' fruit, a thin exocarp forms a shell around the seed while for 'enclosed receptacle' (ER fruit, the seed is embedded in a woody receptacle. We compared the chemical composition of numerous macronutrient and antifeedant in seeds from several Lithocarpus species, focusing on two pairs of sympatric species with different fruit morphologies. We found that macronutrients, particularly total non-structural carbohydrate, was more concentrated in seeds of ER fruits while antifeedants, primarily fibers, were more concentrated in seeds of acorn fruits. The trade-off in these two major chemical components was more evident between the two sympatric lowland species than between two highland species. Surprisingly, no significant difference in overall tannin concentrations in the seeds was observed between the two fruit morphologies. Instead, the major trade-off between macronutrients and antifeedants involved indigestible fibers. Future studies of this complex mutualism should carefully consider the role of indigestible fibers in the foraging behavior of scatter-hoarding rodents.

  7. General meeting. Technical reunion: the numerical and experimental simulation applied to the Reactor Physics; Assemblee generale. Reunion technique: la simulation numerique et experimentale appliquee a la physique des reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-10-01

    The SFEN (French Society on Nuclear Energy), organized the 18 october 2001 at Paris, a technical day on the numerical and experimental simulation, applied to the reactor Physics. Nine aspects were discussed, giving a state of the art in the domain:the french nuclear park; the future technology; the controlled thermonuclear fusion; the new organizations and their implications on the research and development programs; Framatome-ANP markets and industrial code packages; reactor core simulation at high temperature; software architecture; SALOME; DESCARTES. (A.L.B.)

  8. The importance of recording physical and chemical variables simultaneously with remote radiological surveillance of aquatic systems: a perspective for environmental modelling

    International Nuclear Information System (INIS)

    Abril, J.M.; El-Mrabet, R.; Barros, H.

    2004-01-01

    Modern nuclear metrological tools allow the remote surveillance of the radiological status of the aquatic systems, providing an important advance in the protection of the environment. Nevertheless, the significance of the radiological data could be highly improved through simultaneous recording of physical and chemical variables that govern the behaviour and bioavailability of radionuclides in these aquatic systems. This work reviews some of these variables from the point of view of the environmental modelling. The amount, nature and dynamics of the suspended loads and bottom sediments strongly influence the behaviour of particle-reactive radionuclides. The kinetics of this process has a very fast component, as it is shown from our recent studies with 241 Am, 239 Pu and 133 Ba in several aquatic systems from southern Spain. Changes in pH, temperature and in the electrical conductivity are influencing the uptake kinetics and the final partitioning of the radioactivity. Water currents govern the radionuclide transport and dispersion. These points are illustrated with modelling exercises in the scenarios of the Suez Canal (Egypt) and the Haersvatten Lake (Sweden)

  9. Numerical analysis targets

    International Nuclear Information System (INIS)

    Sollogoub, Pierre

    2001-01-01

    Numerical analyses are needed in different steps of the overall design process. Complex models or non-linear reactor core behaviour are important for qualification and/or comparison of results obtained. Adequate models and test should be defined. Fuel assembly, fuel row, and the complete core should be tested for seismic effects causing LOCA and flow-induced vibrations (FIV)

  10. Surface modes in physics

    CERN Document Server

    Sernelius, Bo E

    2011-01-01

    Electromagnetic surface modes are present at all surfaces and interfaces between material of different dielectric properties. These modes have very important effects on numerous physical quantities: adhesion, capillary force, step formation and crystal growth, the Casimir effect etc. They cause surface tension and wetting and they give rise to forces which are important e.g. for the stability of colloids.This book is a useful and elegant approach to the topic, showing how the concept of electromagnetic modes can be developed as a unifying theme for a range of condensed matter physics. The

  11. The importance of psychological and social factors in influencing the uptake and maintenance of physical activity after stroke: a structured review of the empirical literature.

    Science.gov (United States)

    Morris, Jacqui; Oliver, Tracey; Kroll, Thilo; Macgillivray, Steve

    2012-01-01

    Background. People with stroke are not maintaining adequate engagement in physical activity (PA) for health and functional benefit. This paper sought to describe any psychological and social factors that may influence physical activity engagement after stroke. Methods. A structured literature review of studies indexed in MEDLINE, CinAHL, P&BSC, and PsycINFO using search terms relevant to stroke, physical disabilities, and PA. Publications reporting empirical findings (quantitative or qualitative) regarding psychological and/or social factors were included. Results. Twenty studies from 19 publications (9 surveys, 1 RCT, and 10 qualitative studies) were included. Seventeen studies reported findings pertinent to psychological factors and fourteen findings pertinent to social factors. Conclusion. Self-efficacy, physical activity beliefs, and social support appear particularly relevant to physical activity behaviour after stroke and should be included in theoretically based physical interventions. The Transtheoretical Model and the Theory of Planned Behaviour are candidate behavioural models that may support intervention development.

  12. Importancia de la biología molecular para la Fisioterapia moderna Importance of molecular biology for the modern Physical Therapy

    Directory of Open Access Journals (Sweden)

    Carolina Ramírez Ramírez

    2011-12-01

    body, for that reason, molecular biology offers professionals a better understanding of the effect of these types of interventions implemented in different tissues. Thus, the Physical therapists should be aware about the importance of this basic science and its clinical use in everyday problem solving that generate a new evidence-based practice to contribute to professional development. Salud UIS 2011; 43 (3: 317-320

  13. The Importance of Physical Models for Deriving Dust Masses and Grain Size Distributions in Supernova Ejecta. I. Radiatively Heated Dust in the Crab Nebula

    Science.gov (United States)

    Temim, Tea; Dwek, Eli

    2013-01-01

    Recent far-infrared (IR) observations of supernova remnants (SNRs) have revealed significantly large amounts of newly condensed dust in their ejecta, comparable to the total mass of available refractory elements. The dust masses derived from these observations assume that all the grains of a given species radiate at the same temperature, regardless of the dust heating mechanism or grain radius. In this paper, we derive the dust mass in the ejecta of the Crab Nebula, using a physical model for the heating and radiation from the dust. We adopt a power-law distribution of grain sizes and two different dust compositions (silicates and amorphous carbon), and calculate the heating rate of each dust grain by the radiation from the pulsar wind nebula. We find that the grains attain a continuous range of temperatures, depending on their size and composition. The total mass derived from the best-fit models to the observed IR spectrum is 0.019-0.13 Solar Mass, depending on the assumed grain composition. We find that the power-law size distribution of dust grains is characterized by a power-law index of 3.5-4.0 and a maximum grain size larger than 0.1 micron. The grain sizes and composition are consistent with what is expected for dust grains formed in a Type IIP supernova (SN). Our derived dust mass is at least a factor of two less than the mass reported in previous studies of the Crab Nebula that assumed more simplified two-temperature models. These models also require a larger mass of refractory elements to be locked up in dust than was likely available in the ejecta. The results of this study show that a physical model resulting in a realistic distribution of dust temperatures can constrain the dust properties and affect the derived dust masses. Our study may also have important implications for deriving grain properties and mass estimates in other SNRs and for the ultimate question of whether SNe are major sources of dust in the Galactic interstellar medium and in

  14. The importance of cohesion and enjoyment for the fitness improvement of 8-10 year old children participating in a team and individual sport school-based physical activity intervention

    DEFF Research Database (Denmark)

    Elbe, Anne-Marie; Wikman, Johan Michael; Zheng, Miky

    2017-01-01

    This study investigates the enjoyment and cohesion of school children participating in a school-based high-intensity physical activity (PA) intervention. Both enjoyment and cohesion have been found to be important factors for adherence to regular physical and sport activity, an important outcome...... of PA interventions. The sample consisted of 300 pupils (mean age: 9.3 years; 52.7% female) assigned to a team sport intervention, an individual sport intervention, or a control group for 10 months. The Physical Activity Enjoyment Scale and Youth Sport Environment Questionnaire were used to measure...

  15. An Incremental Physically-Based Model of P91 Steel Flow Behaviour for the Numerical Analysis of Hot-Working Processes

    Directory of Open Access Journals (Sweden)

    Alberto Murillo-Marrodán

    2018-04-01

    Full Text Available This paper is aimed at modelling the flow behaviour of P91 steel at high temperature and a wide range of strain rates for constant and also variable strain-rate deformation conditions, such as those in real hot-working processes. For this purpose, an incremental physically-based model is proposed for the P91 steel flow behavior. This formulation considers the effects of dynamic recovery (DRV and dynamic recrystallization (DRX on the mechanical properties of the material, using only the flow stress, strain rate and temperature as state variables and not the accumulated strain. Therefore, it reproduces accurately the flow stress, work hardening and work softening not only under constant, but also under transient deformation conditions. To accomplish this study, the material is characterised experimentally by means of uniaxial compression tests, conducted at a temperature range of 900–1270 °C and at strain rates in the range of 0.005–10 s−1. Finally, the proposed model is implemented in commercial finite element (FE software to provide evidence of the performance of the proposed formulation. The experimental compression tests are simulated using the novel model and the well-known Hansel–Spittel formulation. In conclusion, the incremental physically-based model shows accurate results when work softening is present, especially under variable strain-rate deformation conditions. Hence, the present formulation is appropriate for the simulation of the hot-working processes typically conducted at industrial scale.

  16. Importance of characteristics and modalities of physical activity and exercise in the management of cardiovascular health in individuals with cardiovascular risk factors: recommendations from the EACPR. Part II.

    Science.gov (United States)

    Vanhees, L; Geladas, N; Hansen, D; Kouidi, E; Niebauer, J; Reiner, Z; Cornelissen, V; Adamopoulos, S; Prescott, E; Börjesson, M; Bjarnason-Wehrens, B; Björnstad, H H; Cohen-Solal, A; Conraads, V; Corrado, D; De Sutter, J; Doherty, P; Doyle, F; Dugmore, D; Ellingsen, Ø; Fagard, R; Giada, F; Gielen, S; Hager, A; Halle, M; Heidbüchel, H; Jegier, A; Mazic, S; McGee, H; Mellwig, K P; Mendes, M; Mezzani, A; Pattyn, N; Pelliccia, A; Piepoli, M; Rauch, B; Schmidt-Trucksäss, A; Takken, T; van Buuren, F; Vanuzzo, D

    2012-10-01

    In a previous paper, as the first of a series of three on the importance of characteristics and modalities of physical activity (PA) and exercise in the management of cardiovascular health within the general population, we concluded that, in the population at large, PA and aerobic exercise capacity clearly are inversely associated with increased cardiovascular disease risk and all-cause and cardiovascular mortality and that a dose–response curve on cardiovascular outcome has been demonstrated in most studies. More and more evidence is accumulated that engaging in regular PA and exercise interventions are essential components for reducing the severity of cardiovascular risk factors, such as obesity and abdominal fat, high BP, metabolic risk factors, and systemic inflammation. However, it is less clear whether and which type of PA and exercise intervention (aerobic exercise, dynamic resistive exercise, or both) or characteristic of exercise (frequency, intensity, time or duration, and volume) would yield more benefit for each separate risk factor. The present paper, therefore, will review and make recommendations for PA and exercise training in the management of cardiovascular health in individuals with cardiovascular risk factors. The guidance offered in this series of papers is aimed at medical doctors, health practitioners, kinesiologists, physiotherapists and exercise physiologists, politicians, public health policy makers, and individual members of the public. Based on previous and the current literature overviews, recommendations from the European Association on Cardiovascular Prevention and Rehabilitation are formulated regarding type, volume, and intensity of PA and regarding appropriate risk evaluation during exercise in individuals with cardiovascular risk factors.

  17. Accelerometer measured daily physical activity and sedentary pursuits--comparison between two models of the Actigraph and the importance of data reduction.

    Science.gov (United States)

    Tanha, Tina; Tornberg, Åsa; Dencker, Magnus; Wollmer, Per

    2013-10-31

    Very few validation studies have been performed between different generations of the commonly used Actigraph accelerometers. We compared daily physical activity data generated from the old generation Actigraph model 7164 with the new generation Actigraph GT1M accelerometer in 15 young females for eight consecutive days. We also investigated if different wear time thresholds had any impact on the findings. Minutes per day of moderate and vigorous physical activity (MVPA), vigorous physical activity (VPA) and very vigorous physical activity (VVPA) were calculated. Moreover, minutes of sedentary pursuits per day were calculated. There were significant (P physical activity. Median minutes of sedentary pursuits per day are highly dependent on which wear time threshold that is used, and not by accelerometer model.

  18. Numerical simulation of multiple-physical fields coupling for thermal anomalies before earthquakes: A case study of the 2008 Wenchuan Ms8.0 earthquake in southwest China

    Science.gov (United States)

    Deng, Z.

    2017-12-01

    It has become a highly focused issue that thermal anomalies appear before major earthquakes. There are various hypotheses about the mechanism of thermal anomalies. Because of lacking of enough evidences, the mechanism is still require to be further researched. Gestation and occurrence of a major earthquake is related with the interaction of multi-physical fields. The underground fluid surging out the surface is very likely to be the reason for the thermal anomaly. This study tries to answer some question, such as how the geothermal energy transfer to the surface, and how the multiple-physical fields interacted. The 2008 Wenchuan Ms8.0 earthquake, is one of the largest evens in the last decade in China mainland. Remote sensing studies indicate that distinguishable thermal anomalies occurred several days before the earthquake. The heat anomaly value is more than 3 times the average in normal time and distributes along the Longmen Shan fault zone. Based on geological and geophysical data, 2D dynamic model of coupled stress, seepage and thermal fields (HTM model) is constructed. Then using the COMSOL multi-physics filed software, this work tries to reveal the generation process and distribution patterns of thermal anomalies prior to thrust-type major earthquakes. The simulation get the results: (1)Before the micro rupture, with the increase of compression, the heat current flows to the fault in the footwall on the whole, while in the hanging wall of the fault, particularly near the ground surface, the heat flow upward. In the fault zone, heat flow upward along the fracture surface, heat flux in the fracture zone is slightly larger than the wall rock;, but the value is all very small. (2)After the occurrence of the micro fracture, the heat flow rapidly collects to the faults. In the fault zones, the heat flow accelerates up along the fracture surfaces, the heat flux increases suddenly, and the vertical heat flux reaches to the maximum. The heat flux in the 3 fracture

  19. Numerical analysis using Sage

    CERN Document Server

    Anastassiou, George A

    2015-01-01

    This is the first numerical analysis text to use Sage for the implementation of algorithms and can be used in a one-semester course for undergraduates in mathematics, math education, computer science/information technology, engineering, and physical sciences. The primary aim of this text is to simplify understanding of the theories and ideas from a numerical analysis/numerical methods course via a modern programming language like Sage. Aside from the presentation of fundamental theoretical notions of numerical analysis throughout the text, each chapter concludes with several exercises that are oriented to real-world application.  Answers may be verified using Sage.  The presented code, written in core components of Sage, are backward compatible, i.e., easily applicable to other software systems such as Mathematica®.  Sage is  open source software and uses Python-like syntax. Previous Python programming experience is not a requirement for the reader, though familiarity with any programming language is a p...

  20. Importance measures

    International Nuclear Information System (INIS)

    Gomez Cobo, A.

    1997-01-01

    The presentation discusses the following: general concepts of importance measures; example fault tree, used to illustrate importance measures; Birnbaum's structural importance; criticality importance; Fussel-Vesely importance; upgrading function; risk achievement worth; risk reduction worth

  1. Confidence in Numerical Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Hemez, Francois M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-23

    This PowerPoint presentation offers a high-level discussion of uncertainty, confidence and credibility in scientific Modeling and Simulation (M&S). It begins by briefly evoking M&S trends in computational physics and engineering. The first thrust of the discussion is to emphasize that the role of M&S in decision-making is either to support reasoning by similarity or to “forecast,” that is, make predictions about the future or extrapolate to settings or environments that cannot be tested experimentally. The second thrust is to explain that M&S-aided decision-making is an exercise in uncertainty management. The three broad classes of uncertainty in computational physics and engineering are variability and randomness, numerical uncertainty and model-form uncertainty. The last part of the discussion addresses how scientists “think.” This thought process parallels the scientific method where by a hypothesis is formulated, often accompanied by simplifying assumptions, then, physical experiments and numerical simulations are performed to confirm or reject the hypothesis. “Confidence” derives, not just from the levels of training and experience of analysts, but also from the rigor with which these assessments are performed, documented and peer-reviewed.

  2. Confidence in Numerical Simulations

    International Nuclear Information System (INIS)

    Hemez, Francois M.

    2015-01-01

    This PowerPoint presentation offers a high-level discussion of uncertainty, confidence and credibility in scientific Modeling and Simulation (M&S). It begins by briefly evoking M&S trends in computational physics and engineering. The first thrust of the discussion is to emphasize that the role of M&S in decision-making is either to support reasoning by similarity or to ''forecast,'' that is, make predictions about the future or extrapolate to settings or environments that cannot be tested experimentally. The second thrust is to explain that M&S-aided decision-making is an exercise in uncertainty management. The three broad classes of uncertainty in computational physics and engineering are variability and randomness, numerical uncertainty and model-form uncertainty. The last part of the discussion addresses how scientists ''think.'' This thought process parallels the scientific method where by a hypothesis is formulated, often accompanied by simplifying assumptions, then, physical experiments and numerical simulations are performed to confirm or reject the hypothesis. ''Confidence'' derives, not just from the levels of training and experience of analysts, but also from the rigor with which these assessments are performed, documented and peer-reviewed.

  3. La olfacción: otro componente importante del examen físico Olfaction: another important component of physical examination

    Directory of Open Access Journals (Sweden)

    Marco Antonio Montano Díaz

    2006-12-01

    Full Text Available Se presenta un trabajo donde se revisa la literatura disponible, y se aporta la experiencia personal de los autores sobre la utilidad de la olfacción para realizar un correcto diagnóstico clínico, así como las posibilidades técnicas con que contamos hoy para detectar y medir diversas substancias emanadas del cuerpo humano. Los objetivos propuestos son: cómo promover la idea de incluir la enseñanza organizada y sistemática de la olfacción como un componente importante del examen físico del paciente, y motivar a los tecnólogos para que produzcan y desarrollen instrumentos con los fines expresados. La literatura y la práctica diaria demuestran la abundante y útil información que brinda la olfacción bien realizada. Se expone lo referido sobre la olfacción por varios clásicos de la medicina y por jóvenes especialistas de nuestro tiempo y se concluye que la olfacción debe incluirse junto con la inspección, palpación, percusión y auscultación como otro elemento del examen físico que debe ser enseñado sistemáticamente en nuestras universidades, así como la conveniencia de desarrollar una tecnología que permita detectar substancias volátiles en el aliento y otras emanaciones humanas. No se trata aquí de la utilidad de los olores con fines terapéuticos o de otro tipo que no sea diagnóstico.A study where available medical literature is revised and personal experience of the authors about the usefulness of olfaction is taken in order to carry out a proper clinical diagnosis, as well as the technical possibilities in present days to detect and measure several substances that emanate from the human body. The objectives proposed are: the promotion of the idea to include an organized and systematic teaching of olfaction as an important component of physical examination in patients, and to encourage the technologists to produce and develop instruments with this purpose. Medical literature and daily practice show the abundant and

  4. Importance of characteristics and modalities of physical activity and exercise in the management of cardiovascular health in individuals with cardiovascular disease (Part III).

    Science.gov (United States)

    Vanhees, L; Rauch, B; Piepoli, M; van Buuren, F; Takken, T; Börjesson, M; Bjarnason-Wehrens, B; Doherty, P; Dugmore, D; Halle, M

    2012-12-01

    The beneficial effect of exercise training and exercise-based cardiac rehabilitation on symptom-free exercise capacity,cardiovascular and skeletal muscle function, quality of life, general healthy lifestyle, and reduction of depressive symptoms and psychosocial stress is nowadays well recognized. However, it remains largely obscure, which characteristics of physical activity (PA) and exercise training--frequency, intensity, time (duration), type (mode), and volume (dose: intensity x duration) of exercise--are the most effective. The present paper, therefore, will deal with these exercise characteristics in the management of individuals with cardiovascular disease, i.e. coronary artery disease and chronic heart failure patients, but also in patients with congenital or valvular heart disease. Based on the current literature, and if sufficient evidence is available, recommendations from the European Association on Cardiovascular Prevention and Rehabilitation are formulated regarding frequency, intensity, time and type of PA, and safety aspects during exercise inpatients with cardiovascular disease. This paper is the third in a series of three papers, all devoted to the same theme: the importance of the exercise characteristics in the management of cardiovascular health. Part I is directed to the general population and Part II to individuals with cardiovascular risk factors. In general, PA recommendations and exercise training programmes for patients with coronary artery disease or chronic heart failure need to be tailored to the individual's exercise capacity and risk profile, with the aim to reach and maintain the individually highest fitness level possible and to perform endurance exercise training 30–60 min daily (3–5 days per week) in combination with resistance training 2–3 times a week. Because of the frequently reported dose–response relationship between training effect and exercise intensity, one should seek sufficiently high training intensities

  5. Numerical Modeling of Ocean Circulation

    Science.gov (United States)

    Miller, Robert N.

    2007-01-01

    The modelling of ocean circulation is important not only for its own sake, but also in terms of the prediction of weather patterns and the effects of climate change. This book introduces the basic computational techniques necessary for all models of the ocean and atmosphere, and the conditions they must satisfy. It describes the workings of ocean models, the problems that must be solved in their construction, and how to evaluate computational results. Major emphasis is placed on examining ocean models critically, and determining what they do well and what they do poorly. Numerical analysis is introduced as needed, and exercises are included to illustrate major points. Developed from notes for a course taught in physical oceanography at the College of Oceanic and Atmospheric Sciences at Oregon State University, this book is ideal for graduate students of oceanography, geophysics, climatology and atmospheric science, and researchers in oceanography and atmospheric science. Features examples and critical examination of ocean modelling and results Demonstrates the strengths and weaknesses of different approaches Includes exercises to illustrate major points and supplement mathematical and physical details

  6. Numerical simulation of mechatronic sensors and actuators

    CERN Document Server

    Kaltenbacher, Manfred

    2007-01-01

    Focuses on the physical modeling of mechatronic sensors and actuators and their precise numerical simulation using the Finite Element Method (FEM). This book discusses the physical modeling as well as numerical computation. It also gives a comprehensive introduction to finite elements, including their computer implementation.

  7. Well sibling psychological adjustment to chronic physical disorder in a sibling: how important is maternal awareness of their illness attitudes and perceptions?

    Science.gov (United States)

    Taylor; Fuggle, P; Charman, T

    2001-10-01

    The psychological adjustment of healthy siblings was investigated in relation to their attitudes and perceptions about their brother's or sister's chronic physical disorder, to their mothers' awareness of these attitudes and perceptions, and to three other maternal factors (maternal distress, maternal social support, and amount of care demanded by the physical disorder). Sixty-two well siblings and mothers of children with a range of chronic physical disorders completed standardised questionnaires. The majority of siblings did not appear to have adjustment problems, although the sample had slightly increased rates of emotional symptoms compared to the general population. Mothers rated well siblings as having more negative attitudes and perceptions about the physical disorder than reported by siblings themselves. A multiple regression analysis indicated that better sibling adjustment was associated with higher maternal awareness of their attitudes and perceptions. These findings support Varni and Wallander's (1998) model that emphasises the role of relationship and attitude variables in child adjustment to chronic physical disorder. The implications of these findings for clinical practice are discussed.

  8. The Good Life: Assessing the Relative Importance of Physical, Psychological, and Self-Efficacy Statuses on Quality of Well-Being in Osteoarthritis Patients

    Directory of Open Access Journals (Sweden)

    Charles Van Liew

    2013-01-01

    Full Text Available Background and Purpose. The purpose of the present study was to examine the interrelationships among physical dysfunction, self-efficacy, psychological distress, exercise, and quality of well-being for people with osteoarthritis. It was predicted that exercise would mediate the relationships between physical dysfunction, self-efficacy, psychological distress, and quality of well-being. Methods. Participants were 363 individuals with osteoarthritis who were 60 years of age or older. Data were collected from the baseline assessment period prior to participating in a social support and education intervention. A series of structural equation models was used to test the predicted relationships among the variables. Results. Exercise did not predict quality of well-being and was not related to self-efficacy or psychological distress; it was significantly related to physical dysfunction. When exercise was removed from the model, quality of life was significantly related to self-efficacy, physical dysfunction, and psychological distress. Conclusions. Engagement in exercise was directly related to physical functioning, but none of the other latent variables. Alternatively, treatment focused on self-efficacy and psychological distress might be the most effective way to improve quality of well-being.

  9. Handbook of numerical analysis

    CERN Document Server

    Ciarlet, Philippe G

    Mathematical finance is a prolific scientific domain in which there exists a particular characteristic of developing both advanced theories and practical techniques simultaneously. Mathematical Modelling and Numerical Methods in Finance addresses the three most important aspects in the field: mathematical models, computational methods, and applications, and provides a solid overview of major new ideas and results in the three domains. Coverage of all aspects of quantitative finance including models, computational methods and applications Provides an overview of new ideas an

  10. Modern vacuum physics

    CERN Document Server

    Chambers, Austin

    2005-01-01

    Modern Vacuum Physics presents the principles and practices of vacuum science and technology along with a number of applications in research and industrial production. The first half of the book builds a foundation in gases and vapors under rarefied conditions, The second half presents examples of the analysis of representative systems and describes some of the exciting developments in which vacuum plays an important role. The final chapter addresses practical matters, such as materials, components, and leak detection. Throughout the book, the author''s explanations are presented in terms of first principles and basic physics, augmented by illustrative worked examples and numerous figures.

  11. Development of numerical concepts

    Directory of Open Access Journals (Sweden)

    Sabine Peucker

    2013-06-01

    Full Text Available The development of numerical concepts is described from infancy to preschool age. Infants a few days old exhibit an early sensitivity for numerosities. In the course of development, nonverbal mental models allow for the exact representation of small quantities as well as changes in these quantities. Subitising, as the accurate recognition of small numerosities (without counting, plays an important role. It can be assumed that numerical concepts and procedures start with insights about small numerosities. Protoquantitative schemata comprise fundamental knowledge about quantities. One-to-one-correspondence connects elements and numbers, and, for this reason, both quantitative and numerical knowledge. If children understand that they can determine the numerosity of a collection of elements by enumerating the elements, they have acquired the concept of cardinality. Protoquantitative knowledge becomes quantitative if it can be applied to numerosities and sequential numbers. The concepts of cardinality and part-part-whole are key to numerical development. Developmentally appropriate learning and teaching should focus on cardinality and part-part-whole concepts.

  12. Numerical ecology with R

    CERN Document Server

    Borcard, Daniel; Legendre, Pierre

    2018-01-01

    This new edition of Numerical Ecology with R guides readers through an applied exploration of the major methods of multivariate data analysis, as seen through the eyes of three ecologists. It provides a bridge between a textbook of numerical ecology and the implementation of this discipline in the R language. The book begins by examining some exploratory approaches. It proceeds logically with the construction of the key building blocks of most methods, i.e. association measures and matrices, and then submits example data to three families of approaches: clustering, ordination and canonical ordination. The last two chapters make use of these methods to explore important and contemporary issues in ecology: the analysis of spatial structures and of community diversity. The aims of methods thus range from descriptive to explanatory and predictive and encompass a wide variety of approaches that should provide readers with an extensive toolbox that can address a wide palette of questions arising in contemporary mul...

  13. Numerical experiments with neural networks

    International Nuclear Information System (INIS)

    Miranda, Enrique.

    1990-01-01

    Neural networks are highly idealized models which, in spite of their simplicity, reproduce some key features of the real brain. In this paper, they are introduced at a level adequate for an undergraduate computational physics course. Some relevant magnitudes are defined and evaluated numerically for the Hopfield model and a short term memory model. (Author)

  14. Reduced body weight or increased muscle quality: Which is more important for improving physical function following exercise and weight loss in overweight and obese older women?

    Science.gov (United States)

    Straight, Chad R; Berg, Alison C; Reed, Rachelle A; Johnson, Mary Ann; Evans, Ellen M

    2018-04-19

    The purpose of this study was to examine the relative contributions of changes in muscle quality and body composition to changes in lower-extremity physical function (LEPF) following a 6-month exercise and weight loss intervention in overweight and obese older women. Thirty-eight overweight and obese (BMI = 30.0 ± 4.4 kg/m 2 ) older (age = 69.3 ± 4.1 y) women completed 6 months of multicomponent exercise (cardiorespiratory, resistance, balance and flexibility training) and weight loss (hypocaloric diet that reduced energy intake by ~500 kcal/d). Body composition was measured via dual-energy X-ray absorptiometry and muscle quality (N-m/kg) was defined as maximal concentric isokinetic knee torque divided by upper-leg lean mass. The standardized scores of four objective measures of physical function were summed to yield a composite LEPF Z-score. At 6 months, there were significant reductions in body weight (-9.6 ± 3.5%, p quality (+1.6 ± 1.8 N-m/kg, p quality was the strongest independent predictor of an improvement in LEPF Z-score (standardized β = 0.64, p quality. In conclusion, muscle quality can be increased in the presence of clinically meaningful weight loss, and is the primary determinant of improved physical function in overweight/obese older women. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Physical physics

    CERN Document Server

    Schulman, Mark

    2006-01-01

    "Protons, electrons, positrons, quarks, gluons, muons, shmuons! I should have paid better attention to my high scholl physics teacher. If I had, maybe I could have understood even a fration of what Israeli particle physicist Giora Mikenberg was talking about when explaining his work on the world's largest science experiment." (2 pages)

  16. Numerical and Physical Aspects of Aerodynamic Flows

    Science.gov (United States)

    1992-01-15

    extension to three- implies a trade -off between accuracy and cost which dimensional arrangements is likely to provide a tends to limit the validity of...individually, density and pressure in the 4" direction only is shown in Figure 7e. can improve some grd propertieswhile damagingothers. Forex - Ttal numberof

  17. The importance of daily physical activity for improved exercise tolerance in heart failure patients with limited access to centre-based cardiac rehabilitation.

    Science.gov (United States)

    Sato, Noriaki; Origuchi, Hideki; Yamamoto, Umpei; Takanaga, Yasuhiro; Mohri, Masahiro

    2012-09-01

    Supervised cardiac rehabilitation provided at dedicated centres ameliorates exercise intolerance in patients with chronic heart failure. To correlate the amount of physical activity outside the hospital with improved exercise tolerance in patients with limited access to centre-based programs. Forty patients (median age 69 years) with stable heart failure due to systolic left ventricular dysfunction participated in cardiac rehabilitation once per week for five months. Using a validated single-axial accelerometer, the number of steps and physical activity-related energy expenditures on nonrehabilitation days were determined. Median (interquartile range) peak oxygen consumption was increased from 14.4 mL/kg/min (range 12.9 mL/kg/min to 17.8 mL/kg/min) to 16.4 mL/kg/min (range 13.9 mL/kg/min to 19.1 mL/kg/min); Pdaily number of steps (Pexercise time per day and time spent for light (≤3 metabolic equivalents) exercise, but not with time spent for moderate/vigorous (>3 metabolic equivalents) exercise. The number of steps and energy expenditures outside the hospital were correlated with improved exercise capacity. An accelerometer may be useful for guiding home-based cardiac rehabilitation.

  18. The importance of economic, social and cultural capital in understanding health inequalities: using a Bourdieu-based approach in research on physical and mental health perceptions.

    Science.gov (United States)

    Pinxten, Wouter; Lievens, John

    2014-09-01

    In this article we adopt a Bourdieu-based approach to study social inequalities in perceptions of mental and physical health. Most research takes into account the impact of economic or social capital on health inequalities. Bourdieu, however, distinguishes between three forms of capital that can determine peoples' social position: economic, social and cultural capital. Health research examining the effects of cultural capital is scarce. By simultaneously considering and modelling indicators of each of Bourdieu's forms of capital, we further the understanding of the dynamics of health inequalities. Using data from a large-scale representative survey (N = 1825) in Flanders, Belgium, we find that each of the forms of capital has a net effect on perceptions of physical and mental health, which persists after controlling for the other forms of capital and for the effects of other correlates of perceived health. The only exception is that the cultural capital indicators are not related to mental health. These results confirm the value of a Bourdieu-based approach and indicate the need to consider economic, social and cultural capital to obtain a better understanding of social inequality in health. © 2014 The Authors. Sociology of Health & Illness © 2014 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

  19. [Sick leave during pregnancy: an analysis of French hospitals from 2005 until 2008 demonstrates the major importance for jobs with physical demands].

    Science.gov (United States)

    Estryn-Behar, Madeleine; Amar, Emile; Choudat, Dominique

    2013-06-01

    sick-leave in the course of pregnancy play a role under estimated according to several studies.They bring to light the existence of risk factors concerning the physical load for contractions, sick-leave, hospitalizations and prematurity.The data obtained on the totality of the wage earners of the AP-HP allow to avoid all the possible bias and to determine the potential impact of a policy of reduction of the physical load The data of four years could be analyzed.The used database is PILOT RH, intranet application restoring information extracted from GIPSIE who was until 2008 the institutional software of management of the careers of all the workers of the AP-HP. In 2008,3 937 women having had a maternity leave (ML) accumulated 132 360 days of ordinary sick-leave (OL) (that is 33,6 days on average) without inclusion of the 15 days accepted for "pathological pregnancy" (PP) and "post pregnancy leave". Ordinary sick-leave of all the 53 132 women amounts to 11.5 days by agent. But, the set apart of the women having had a ML reduces the number of days of sick-leave to 9,7 days This difference weighs for 15.6 % of the total of the absenteeism OL. The results are similar on the four years. The analysis by occupational catégory, for 2008, shows that the average number of days of sick-leave, after exclusion of women having had a ML, decreases with the physical load of the posts estimated by the study PRESST-NEXT :ancillary staff 19.9 days, nursing aids 13.7 days, registered nurses 8.2 days, specialized nurses 7.7 days, medico - technical workers 5.7 days and head nurses 5.1 days. For the women having had a ML, the average number of days of ordinary sick-leave, is the most raised for nursing aids (41.9 days) followed by the ancillary staff (36 days) and the registered nurses (36 days) and slightly less for the specialized nurses (28.3 days). On the other hand, in the professions having least physical load the women have less than 25 days of ordinary sick-leave the year of

  20. The Evolution of Physical Activity Promotion.

    Science.gov (United States)

    Richards, Elizabeth Ann

    2015-08-01

    A physically active lifestyle has numerous physical and mental health benefits for patients of all ages. Despite these significant benefits, a majority of Americans do not meet current physical activity guidelines. Health care providers, especially nurses, play a vital role in physical activity promotion. Over the past several decades, exercise and physical activity guidelines have evolved from a focus on structured, vigorous exercise to a focus on moderate-intensity "lifestyle" physical activity. The author updates nurses on physical activity guidelines and provides tips for promoting physical activity, with a focus on lifestyle activities such as walking to work. This article also addresses new research findings on the importance of decreasing sedentary and sitting time, even in physically active people.

  1. Familial Risk of Chronic Musculoskeletal Pain and the Importance of Physical Activity and Body Mass Index: Prospective Data from the HUNT Study, Norway.

    Science.gov (United States)

    Lier, Ragnhild; Mork, Paul Jarle; Holtermann, Andreas; Nilsen, Tom Ivar Lund

    2016-01-01

    The main objectives of the current study was i) to prospectively examine if chronic musculoskeletal pain in parents is associated with risk of chronic musculoskeletal pain in their adult offspring, and ii) to assess if these parent-offspring associations are modified by offspring body mass index and leisure time physical activity. We used data on 4,742 adult offspring linked with their parents who participated in the population-based HUNT Study in Norway in 1995-97 and in 2006-08. Family relations were established through the national Family Registry. A Poisson regression model was used to estimate relative risk (RR) with 95% confidence interval (CI). In total, 1,674 offspring (35.3%) developed chronic musculoskeletal pain during the follow-up period of approximately 11 years. Both maternal (RR: 1.26, 95% CI: 1.03, 1.55) and paternal chronic musculoskeletal pain (RR: 1.29, 95% CI: 1.06, 1.57) was associated with increased risk of offspring chronic musculoskeletal pain. Compared to offspring of parents without chronic musculoskeletal pain, the adverse effect of parental pain was somewhat stronger among offspring who reported a low (RR: 1.82, 95% CI: 1.32, 2.52) versus high (RR: 1.32, 95% CI: 0.95, 1.84) level of leisure time physical activity. Offspring of parents with chronic musculoskeletal pain and who were classified as obese had more than twofold increased risk (RR: 2.33, 95% CI: 1.68, 3.24) of chronic musculoskeletal pain compared to normal weight offspring of parents without pain. In conclusion, parental chronic musculoskeletal pain is positively associated with risk of chronic musculoskeletal pain in their adult offspring. Maintenance of normal body weight may reduce the risk of chronic musculoskeletal pain in offspring of pain-afflicted parents.

  2. Familial Risk of Chronic Musculoskeletal Pain and the Importance of Physical Activity and Body Mass Index: Prospective Data from the HUNT Study, Norway.

    Directory of Open Access Journals (Sweden)

    Ragnhild Lier

    Full Text Available The main objectives of the current study was i to prospectively examine if chronic musculoskeletal pain in parents is associated with risk of chronic musculoskeletal pain in their adult offspring, and ii to assess if these parent-offspring associations are modified by offspring body mass index and leisure time physical activity. We used data on 4,742 adult offspring linked with their parents who participated in the population-based HUNT Study in Norway in 1995-97 and in 2006-08. Family relations were established through the national Family Registry. A Poisson regression model was used to estimate relative risk (RR with 95% confidence interval (CI. In total, 1,674 offspring (35.3% developed chronic musculoskeletal pain during the follow-up period of approximately 11 years. Both maternal (RR: 1.26, 95% CI: 1.03, 1.55 and paternal chronic musculoskeletal pain (RR: 1.29, 95% CI: 1.06, 1.57 was associated with increased risk of offspring chronic musculoskeletal pain. Compared to offspring of parents without chronic musculoskeletal pain, the adverse effect of parental pain was somewhat stronger among offspring who reported a low (RR: 1.82, 95% CI: 1.32, 2.52 versus high (RR: 1.32, 95% CI: 0.95, 1.84 level of leisure time physical activity. Offspring of parents with chronic musculoskeletal pain and who were classified as obese had more than twofold increased risk (RR: 2.33, 95% CI: 1.68, 3.24 of chronic musculoskeletal pain compared to normal weight offspring of parents without pain. In conclusion, parental chronic musculoskeletal pain is positively associated with risk of chronic musculoskeletal pain in their adult offspring. Maintenance of normal body weight may reduce the risk of chronic musculoskeletal pain in offspring of pain-afflicted parents.

  3. Partial Differential Equations Modeling and Numerical Simulation

    CERN Document Server

    Glowinski, Roland

    2008-01-01

    This book is dedicated to Olivier Pironneau. For more than 250 years partial differential equations have been clearly the most important tool available to mankind in order to understand a large variety of phenomena, natural at first and then those originating from human activity and technological development. Mechanics, physics and their engineering applications were the first to benefit from the impact of partial differential equations on modeling and design, but a little less than a century ago the Schrödinger equation was the key opening the door to the application of partial differential equations to quantum chemistry, for small atomic and molecular systems at first, but then for systems of fast growing complexity. Mathematical modeling methods based on partial differential equations form an important part of contemporary science and are widely used in engineering and scientific applications. In this book several experts in this field present their latest results and discuss trends in the numerical analy...

  4. Physical mapping of chromosome 17p13.3 in the region of a putative tumor suppressor gene important in medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, J.D.; Daneshvar, L.; Willert, J.R. [Univ. of California, San Franciso, CA (United States)] [and others

    1994-09-01

    Deletion mapping of a medulloblastoma tumor panel revealed loss of distal chromosome 17p13.3 sequences in tumors from 14 of 32 patients (44%). Of the 14 tumors showing loss of heterozygosity by restriction fragment length polymorphism analysis, 14 of 14 (100%) displayed loss of the telomeric marker p144-D6 (D17S34), while a probe for the ABR gene on 17p13.3 was lost in 7 of 8 (88%) informative cases. Using pulsed-field gel electrophoresis, we localized the polymorphic marker (VNTR-A) of the ABR gene locus to within 220 kb of the p144-D6 locus. A cosmid contig constructed in this region was used to demonstrate by fluorescence in situ hybridization that the ABR gene is oriented transcriptionally 5{prime} to 3{prime} toward the telomere. This report provides new physical mapping data for the ABR gene, which has not been previously shown to be deleted in medulloblastoma. These results provide further evidence for the existence of a second tumor suppressor gene distinct from p53 on distal chromosome 17p. 12 refs., 3 figs.

  5. Importance Profiles for Water Vapor

    Science.gov (United States)

    Mapes, Brian; Chandra, Arunchandra S.; Kuang, Zhiming; Zuidema, Paquita

    2017-11-01

    Motivated by the scientific desire to align observations with quantities of physical interest, we survey how scalar importance functions depend on vertically resolved water vapor. Definitions of importance begin from familiar examples of water mass I m and TOA clear-sky outgoing longwave flux I OLR, in order to establish notation and illustrate graphically how the sensitivity profile or "kernel" depends on whether specific humidity S, relative humidity R, or ln( R) are used as measures of vapor. Then, new results on the sensitivity of convective activity I con to vapor (with implied knock-on effects such as weather prediction skill) are presented. In radiative-convective equilibrium, organized (line-like) convection is much more sensitive to moisture than scattered isotropic convection, but it exists in a drier mean state. The lesson for natural convection may be that organized convection is less susceptible to dryness and can survive and propagate into regions unfavorable for disorganized convection. This counterintuitive interpretive conclusion, with respect to the narrow numerical result behind it, highlights the importance of clarity about what is held constant at what values in sensitivity or susceptibility kernels. Finally, the sensitivities of observable radiance signals I sig for passive remote sensing are considered. While the accuracy of R in the lower free troposphere is crucial for the physical importance scalars, this layer is unfortunately the most difficult to isolate with passive remote sensing: In high emissivity channels, water vapor signals come from too high in the atmosphere (for satellites) or too low (for surface radiometers), while low emissivity channels have poor altitude discrimination and (in the case of satellites) are contaminated by surface emissions. For these reasons, active ranging (LiDAR) is the preferred observing strategy.

  6. IMPORTANT NOTIFICATION

    CERN Multimedia

    HR Department

    2009-01-01

    Green plates, removals and importation of personal effects Please note that, as from 1 April 2009, formalities relating to K and CD special series French vehicle plates (green plates), removals and importation of personal effects into France and Switzerland will be dealt with by GS Department (Building 73/3-014, tel. 73683/74407). Importation and purchase of tax-free vehicles in Switzerland, as well as diplomatic privileges, will continue to be dealt with by the Installation Service of HR Department (Building 33/1-011, tel. 73962). HR and GS Departments

  7. Rehabilitation after hallux valgus surgery: importance of physical therapy to restore weight bearing of the first ray during the stance phase.

    Science.gov (United States)

    Schuh, Reinhard; Hofstaetter, Stefan G; Adams, Samuel B; Pichler, Florian; Kristen, Karl-Heinz; Trnka, Hans-Joerg

    2009-09-01

    Operative treatment of people with hallux valgus can yield favorable clinical and radiographic results. However, plantar pressure analysis has demonstrated that physiologic gait patterns are not restored after hallux valgus surgery. The purpose of this study was to illustrate the changes of plantar pressure distribution during the stance phase of gait in patients who underwent hallux valgus surgery and received a multimodal rehabilitation program. This was a prospective descriptive study. Thirty patients who underwent Austin (n=20) and scarf (n=10) osteotomy for correction of mild to moderate hallux valgus deformity were included in this study. Four weeks postoperatively they received a multimodal rehabilitation program once per week for 4 to 6 weeks. Plantar pressure analysis was performed preoperatively and 4 weeks, 8 weeks, and 6 months postoperatively. In addition, range of motion of the first metatarsophalangeal joint was measured, and the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot questionnaire was administered preoperatively and at 6 months after surgery. The mean AOFAS score significantly increased from 60.7 points (SD=11.9) preoperatively to 94.5 points (SD=4.5) 6 months after surgery. First metatarsophalangeal joint range of motion increased at 6 months postoperatively, with a significant increase in isolated dorsiflexion. In the first metatarsal head region, maximum force increased from 117.8 N to 126.4 N and the force-time integral increased from 37.9 N.s to 55.6 N.s between the preoperative and 6-month assessments. In the great toe region, maximum force increased from 66.1 N to 87.2 N and the force-time integral increased from 18.7 N.s to 24.2 N.s between the preoperative and 6-month assessments. A limitation of the study was the absence of a control group due to the descriptive nature of the study. The results suggest that postoperative physical therapy and gait training may lead to improved function and weight bearing of the first

  8. Numerical Optimization in Microfluidics

    DEFF Research Database (Denmark)

    Jensen, Kristian Ejlebjærg

    2017-01-01

    Numerical modelling can illuminate the working mechanism and limitations of microfluidic devices. Such insights are useful in their own right, but one can take advantage of numerical modelling in a systematic way using numerical optimization. In this chapter we will discuss when and how numerical...... optimization is best used....

  9. Methods of numerical relativity

    International Nuclear Information System (INIS)

    Piran, T.

    1983-01-01

    Numerical Relativity is an alternative to analytical methods for obtaining solutions for Einstein equations. Numerical methods are particularly useful for studying generation of gravitational radiation by potential strong sources. The author reviews the analytical background, the numerical analysis aspects and techniques and some of the difficulties involved in numerical relativity. (Auth.)

  10. An outline review of numerical transport methods

    International Nuclear Information System (INIS)

    Budd, C.

    1981-01-01

    A brief review is presented of numerical methods for solving the neutron transport equation in the context of reactor physics. First the various forms of transport equation are given. Second, the various ways of classifying numerical transport methods are discussed. Finally each method (or class of methods) is outlined in turn. (U.K.)

  11. Forecasting Italian seismicity through a spatio-temporal physical model: importance of considering time-dependency and reliability of the forecast

    Directory of Open Access Journals (Sweden)

    Amir Hakimhashemi

    2010-11-01

    Full Text Available We apply here a forecasting model to the Italian region for the spatio-temporal distribution of seismicity based on a smoothing Kernel function, Coulomb stress variations, and a rate-and-state friction law. We tested the feasibility of this approach, and analyzed the importance of introducing time-dependency in forecasting future events. The change in seismicity rate as a function of time was estimated by calculating the Coulomb stress change imparted by large earthquakes. We applied our approach to the region of Italy, and used all of the cataloged earthquakes that occurred up to 2006 to generate the reference seismicity rate. For calculation of the time-dependent seismicity rate changes, we estimated the rate-and-state stress transfer imparted by all of the ML≥4.0 earthquakes that occurred during 2007 and 2008. To validate the results, we first compared the reference seismicity rate with the distribution of ML≥1.8 earthquakes since 2007, using both a non-declustered and a declustered catalog. A positive correlation was found, and all of the forecast earthquakes had locations within 82% and 87% of the study area with the highest seismicity rate, respectively. Furthermore, 95% of the forecast earthquakes had locations within 27% and 47% of the study area with the highest seismicity rate, respectively. For the time-dependent seismicity rate changes, the number of events with locations in the regions with a seismicity rate increase was 11% more than in the regions with a seismicity rate decrease.

  12. Numerical simulation of inertial two-phase flow in heterogenous media

    International Nuclear Information System (INIS)

    Ali Akbar ABBASIAN ARANI; Didier LASSEUX; Azita AHMADI

    2005-01-01

    In this work, we present the development of a 3 D numerical tool for simulation of non-Darcy two-phase flow in heterogeneous porous media. The physical model selected is the generalized Darcy-Forchheimer model. A validation is performed first by comparing numerical results with a semi-analytical solution of the Buckley-Leverett type. Secondly, numerical results obtained on 1 D and 2 D heterogeneous configurations are presented and we highlight the importance of the inertial terms according to a Reynolds number of the flow. (authors)

  13. Numerical models for differential problems

    CERN Document Server

    Quarteroni, Alfio

    2017-01-01

    In this text, we introduce the basic concepts for the numerical modelling of partial differential equations. We consider the classical elliptic, parabolic and hyperbolic linear equations, but also the diffusion, transport, and Navier-Stokes equations, as well as equations representing conservation laws, saddle-point problems and optimal control problems. Furthermore, we provide numerous physical examples which underline such equations. We then analyze numerical solution methods based on finite elements, finite differences, finite volumes, spectral methods and domain decomposition methods, and reduced basis methods. In particular, we discuss the algorithmic and computer implementation aspects and provide a number of easy-to-use programs. The text does not require any previous advanced mathematical knowledge of partial differential equations: the absolutely essential concepts are reported in a preliminary chapter. It is therefore suitable for students of bachelor and master courses in scientific disciplines, an...

  14. Telesna samopodoba kot pomemben motivacijski dejavnik za gibalno/športno aktivnost otrok in mladostnikov: Physical self-conception as an important motivational factor for physical activity among children and adolescents:

    OpenAIRE

    Dolenc, Petra

    2010-01-01

    Self-conception is a multidimensional construct that refers to an individual’s perception of »self«. This percepion not only affects the psychological well-being of children and adolescents but also their motivation and behaviour. The formation of their self-conception represents an important developmental task in childhood and adolescence. Research findings suggest that one’s self conception becomes more varied and complex with age. The multidimensionality of self-conception em- phasizes tha...

  15. PHYSICS UPDATE: The global positioning system

    Science.gov (United States)

    Walton, Alan J.; Black, Richard J.

    1999-01-01

    A hand-held global positioning system receiver displays the operator's latitude, longitude and velocity. Knowledge of GCSE-level physics will allow the basic principles of the system to be understood; knowledge of A-level physics will allow many important aspects of their implementation to be comprehended. A discussion of the system provides many simple numerical calculations relevant to school and first-year undergraduate syllabuses.

  16. Ocean wave prediction using numerical and neural network models

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Prabaharan, N.

    This paper presents an overview of the development of the numerical wave prediction models and recently used neural networks for ocean wave hindcasting and forecasting. The numerical wave models express the physical concepts of the phenomena...

  17. Atomic physics

    CERN Document Server

    Born, Max

    1969-01-01

    The Nobel Laureate's brilliant exposition of the kinetic theory of gases, elementary particles, the nuclear atom, wave-corpuscles, atomic structure and spectral lines, electron spin and Pauli's principle, quantum statistics, molecular structure and nuclear physics. Over 40 appendices, a bibliography, numerous figures and graphs.

  18. The importance of cohesion and enjoyment for the fitness improvement of 8-10-year-old children participating in a team and individual sport school-based physical activity intervention.

    Science.gov (United States)

    Elbe, Anne-Marie; Wikman, Johan Michael; Zheng, Miky; Larsen, Malte Nejst; Nielsen, Glen; Krustrup, Peter

    2017-04-01

    This study investigates the enjoyment and cohesion of school children participating in a school-based high-intensity physical activity (PA) intervention. Both enjoyment and cohesion have been found to be important factors for adherence to regular physical and sport activity, an important outcome of PA interventions. The sample consisted of 300 pupils (mean age: 9.3 years; 52.7% female) assigned to a team sport intervention, an individual sport intervention, or a control group for 10 months. The Physical Activity Enjoyment Scale and Youth Sport Environment Questionnaire were used to measure enjoyment and cohesion. The Yo-Yo IR1C test determined fitness improvements. Results showed that enjoyment and cohesion (social) measured at the beginning of the intervention significantly predict fitness improvements achieved after 10 months. No differing developmental effects over time could be found in the intervention groups with regard to cohesion and enjoyment when comparing them to the control group. However, enjoyment and cohesion (social) significantly decreased in the groups that performed individual sports. Team sports seem to be more advantageous for the development of enjoyment and cohesion, which are both factors that positively impact the health outcomes of the intervention.

  19. Numerical model SMODERP

    Science.gov (United States)

    Kavka, P.; Jeřábek, J.; Strouhal, L.

    2016-12-01

    The contribution presents a numerical model SMODERP that is used for calculation and prediction of surface runoff and soil erosion from agricultural land. The physically based model includes the processes of infiltration (Phillips equation), surface runoff routing (kinematic wave based equation), surface retention, surface roughness and vegetation impact on runoff. The model is being developed at the Department of Irrigation, Drainage and Landscape Engineering, Civil Engineering Faculty, CTU in Prague. 2D version of the model was introduced in last years. The script uses ArcGIS system tools for data preparation. The physical relations are implemented through Python scripts. The main computing part is stand alone in numpy arrays. Flow direction is calculated by Steepest Descent algorithm and in multiple flow algorithm. Sheet flow is described by modified kinematic wave equation. Parameters for five different soil textures were calibrated on the set of hundred measurements performed on the laboratory and filed rainfall simulators. Spatially distributed models enable to estimate not only surface runoff but also flow in the rills. Development of the rills is based on critical shear stress and critical velocity. For modelling of the rills a specific sub model was created. This sub model uses Manning formula for flow estimation. Flow in the ditches and streams are also computed. Numerical stability of the model is controled by Courant criterion. Spatial scale is fixed. Time step is dynamic and depends on the actual discharge. The model is used in the framework of the project "Variability of Short-term Precipitation and Runoff in Small Czech Drainage Basins and its Influence on Water Resources Management". Main goal of the project is to elaborate a methodology and online utility for deriving short-term design precipitation series, which could be utilized by a broad community of scientists, state administration as well as design planners. The methodology will account for

  20. Importance classification

    International Nuclear Information System (INIS)

    Mizumachi, Wataru; Kobayashi, Masahide

    2008-01-01

    Conventionally, the design of a nuclear reactor has been performed from a viewpoint of a safety function and the importance on earthquake-proof on the basis of not giving off the mainly included radioactivity outside. In this Niigataken-Chuetsuoki earthquake, there is almost no damage to the system, components and structure on safe also in the earthquake beyond assumption, and the validity of the design was checked. But, the situation peculiar to a big earthquake was also generated. The emergency plan room which should serve as a connection center with the exterior was not able to open a door and use at the beginning. Fire-extinguishing system piping fractured and self-defense fire fighting was not made. And so on. Discussion from the following three viewpoints was performed. 1st: The importance from a viewpoint which should maintain a function also with the disaster in case of an earthquake like an emergency plan room etc. 2nd: In the earthquake, since the safe system and un-safe system was influenced, the importance from a viewpoint which may have influence safely inquired when the un-safe system broke down. 3rd: Although it was not directly related safely, discussion from a viewpoint which influences fear of insecurity, such as taking out smoke, for example, was performed (author)

  1. Essential numerical computer methods

    CERN Document Server

    Johnson, Michael L

    2010-01-01

    The use of computers and computational methods has become ubiquitous in biological and biomedical research. During the last 2 decades most basic algorithms have not changed, but what has is the huge increase in computer speed and ease of use, along with the corresponding orders of magnitude decrease in cost. A general perception exists that the only applications of computers and computer methods in biological and biomedical research are either basic statistical analysis or the searching of DNA sequence data bases. While these are important applications they only scratch the surface of the current and potential applications of computers and computer methods in biomedical research. The various chapters within this volume include a wide variety of applications that extend far beyond this limited perception. As part of the Reliable Lab Solutions series, Essential Numerical Computer Methods brings together chapters from volumes 210, 240, 321, 383, 384, 454, and 467 of Methods in Enzymology. These chapters provide ...

  2. Numerical relativity beyond astrophysics

    Science.gov (United States)

    Garfinkle, David

    2017-01-01

    Though the main applications of computer simulations in relativity are to astrophysical systems such as black holes and neutron stars, nonetheless there are important applications of numerical methods to the investigation of general relativity as a fundamental theory of the nature of space and time. This paper gives an overview of some of these applications. In particular we cover (i) investigations of the properties of spacetime singularities such as those that occur in the interior of black holes and in big bang cosmology. (ii) investigations of critical behavior at the threshold of black hole formation in gravitational collapse. (iii) investigations inspired by string theory, in particular analogs of black holes in more than 4 spacetime dimensions and gravitational collapse in spacetimes with a negative cosmological constant.

  3. Numerical relativity beyond astrophysics.

    Science.gov (United States)

    Garfinkle, David

    2017-01-01

    Though the main applications of computer simulations in relativity are to astrophysical systems such as black holes and neutron stars, nonetheless there are important applications of numerical methods to the investigation of general relativity as a fundamental theory of the nature of space and time. This paper gives an overview of some of these applications. In particular we cover (i) investigations of the properties of spacetime singularities such as those that occur in the interior of black holes and in big bang cosmology. (ii) investigations of critical behavior at the threshold of black hole formation in gravitational collapse. (iii) investigations inspired by string theory, in particular analogs of black holes in more than 4 spacetime dimensions and gravitational collapse in spacetimes with a negative cosmological constant.

  4. Numerical methods in multibody dynamics

    CERN Document Server

    Eich-Soellner, Edda

    1998-01-01

    Today computers play an important role in the development of complex mechanical systems, such as cars, railway vehicles or machines. Efficient simulation of these systems is only possible when based on methods that explore the strong link between numerics and computational mechanics. This book gives insight into modern techniques of numerical mathematics in the light of an interesting field of applications: multibody dynamics. The important interaction between modeling and solution techniques is demonstrated by using a simplified multibody model of a truck. Different versions of this mechanical model illustrate all key concepts in static and dynamic analysis as well as in parameter identification. The book focuses in particular on constrained mechanical systems. Their formulation in terms of differential-algebraic equations is the backbone of nearly all chapters. The book is written for students and teachers in numerical analysis and mechanical engineering as well as for engineers in industrial research labor...

  5. Numerical simulation of flood barriers

    Science.gov (United States)

    Srb, Pavel; Petrů, Michal; Kulhavý, Petr

    This paper deals with testing and numerical simulating of flood barriers. The Czech Republic has been hit by several very devastating floods in past years. These floods caused several dozens of causalities and property damage reached billions of Euros. The development of flood measures is very important, especially for the reduction the number of casualties and the amount of property damage. The aim of flood control measures is the detention of water outside populated areas and drainage of water from populated areas as soon as possible. For new flood barrier design it is very important to know its behaviour in case of a real flood. During the development of the barrier several standardized tests have to be carried out. Based on the results from these tests numerical simulation was compiled using Abaqus software and some analyses were carried out. Based on these numerical simulations it will be possible to predict the behaviour of barriers and thus improve their design.

  6. Particle physics

    CERN Document Server

    Martin, Brian R

    2017-01-01

    An accessible and carefully structured introduction to Particle Physics, including important coverage of the Higgs Boson and recent progress in neutrino physics. Fourth edition of this successful title in the Manchester Physics series. Includes information on recent key discoveries including : An account of the discovery of exotic hadrons, beyond the simple quark model; Expanded treatments of neutrino physics and CP violation in B-decays; An updated account of ‘physics beyond the standard model’, including the interaction of particle physics with cosmology; Additional problems in all chapters, with solutions to selected problems available on the book’s website; Advanced material appears in optional starred sections.

  7. Computational physics

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-01-15

    Computers have for many years played a vital role in the acquisition and treatment of experimental data, but they have more recently taken up a much more extended role in physics research. The numerical and algebraic calculations now performed on modern computers make it possible to explore consequences of basic theories in a way which goes beyond the limits of both analytic insight and experimental investigation. This was brought out clearly at the Conference on Perspectives in Computational Physics, held at the International Centre for Theoretical Physics, Trieste, Italy, from 29-31 October.

  8. Computational physics

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Computers have for many years played a vital role in the acquisition and treatment of experimental data, but they have more recently taken up a much more extended role in physics research. The numerical and algebraic calculations now performed on modern computers make it possible to explore consequences of basic theories in a way which goes beyond the limits of both analytic insight and experimental investigation. This was brought out clearly at the Conference on Perspectives in Computational Physics, held at the International Centre for Theoretical Physics, Trieste, Italy, from 29-31 October

  9. Black-Hole Binaries, Gravitational Waves, and Numerical Relativity

    Science.gov (United States)

    Kelly, Bernard J.; Centrella, Joan; Baker, John G.; Kelly, Bernard J.; vanMeter, James R.

    2010-01-01

    Understanding the predictions of general relativity for the dynamical interactions of two black holes has been a long-standing unsolved problem in theoretical physics. Black-hole mergers are monumental astrophysical events ' releasing tremendous amounts of energy in the form of gravitational radiation ' and are key sources for both ground- and spacebased gravitational wave detectors. The black-hole merger dynamics and the resulting gravitational waveforms can only he calculated through numerical simulations of Einstein's equations of general relativity. For many years, numerical relativists attempting to model these mergers encountered a host of problems, causing their codes to crash after just a fraction of a binary orbit cnuld be simulated. Recently ' however, a series of dramatic advances in numerical relativity has ' for the first time, allowed stable / robust black hole merger simulations. We chronicle this remarkable progress in the rapidly maturing field of numerical relativity, and the new understanding of black-hole binary dynamics that is emerging. We also discuss important applications of these fundamental physics results to astrophysics, to gravitationalwave astronomy, and in other areas.

  10. Direct numerical simulations of nucleate boiling flows of binary mixtures

    International Nuclear Information System (INIS)

    Didier Jamet; Celia Fouillet

    2005-01-01

    Full text of publication follows: Better understand the origin and characteristics of boiling crisis is still a scientific challenge despite many years of valuable studies. One of the reasons why boiling crisis is so difficult to understand is that local and coupled physical phenomena are believed to play a key role in the trigger of instabilities which lead to the dry out of large portions of the heated solid phase. Nucleate boiling of a single bubble is fairly well understood compared to boiling crisis. Therefore, the numerical simulation of a single bubble growth during nucleate boiling is a good candidate to evaluate the capabilities of a numerical method to deal with complex liquid-vapor phenomena with phase-change and eventually to tackle the boiling crisis problem. In this paper, we present results of direct numerical simulations of nucleate boiling. The numerical method used is the second gradient method, which is a diffuse interface method dedicated to liquid vapor flows with phase-change. This study is not intended to provide quantitative results, partly because all the simulations are two-dimensional. However, particular attention is paid to the influence of some parameters on the main features of nucleate boiling, i.e. the radius of departure and the frequency of detachment of bubbles. In particular, we show that, as the contact angle increases, the radius of departure increases whereas the frequency of detachment decreases. Moreover, the influence of the existence of quasi non-condensable gas is studied. Numerical results show an important decrease of the heat exchange coefficient when a small amount of a quasi non-condensable gas is added to the pure liquid-vapor water system. This result is in agreement with experimental observations. Beyond these qualitative results, this numerical study allows to get insight into some important physical phenomena and to confirm that during nucleate boiling, large scale quantities are influenced by small scale

  11. Unconventional imports

    International Nuclear Information System (INIS)

    Yamaguchi, N.D.

    2001-01-01

    This article focuses on bitumens and bitumen products from Canadian oil sands and explores how they will affect the Canadian oil industry and the US refining industry. The falling production of crude, the growing demand for it, and the stagnating refining capacity in the US are reported, and Canadian and Mexican exports to the US, the definition of bitumens and bitumen quality, and the position of Canada as world leader in bitumen resources are considered. Bitumen production techniques, sales of bitumens and synthetic crude, the production outlook, and the quality and refining of bitumen and synthetic crude are examined. Plots illustrating North American crude refining capacity, production and demand for 1980-2000; US crude imports from Canada and Mexico (1981-2000), world proven oil reserves (2001), world bitumen resources, and Canadian oil production (1998-2000) are provided. Details of the composition of crudes and bitumens, and recent synthetic crude production are tabulated

  12. Fundamentals of Nuclear Reactor Physics

    CERN Document Server

    Lewis, E E

    2008-01-01

    This new streamlined text offers a one-semester treatment of the essentials of how the fission nuclear reactor works, the various approaches to the design of reactors, and their safe and efficient operation. The book includes numerous worked-out examples and end-of-chapter questions to help reinforce the knowledge presented. This textbook offers an engineering-oriented introduction to nuclear physics, with a particular focus on how those physics are put to work in the service of generating nuclear-based power, particularly the importance of neutron reactions and neutron behavior. Engin

  13. Numerical modelling of river morphodynamics: Latest developments and remaining challenges

    Science.gov (United States)

    Siviglia, Annunziato; Crosato, Alessandra

    2016-07-01

    Numerical morphodynamic models provide scientific frameworks for advancing our understanding of river systems. The research on involved topics is an important and socially relevant undertaking regarding our environment. Nowadays numerical models are used for different purposes, from answering questions about basic morphodynamic research to managing complex river engineering problems. Due to increasing computer power and the development of advanced numerical techniques, morphodynamic models are now more and more used to predict the bed patterns evolution to a broad spectrum of spatial and temporal scales. The development and the success of application of such models are based upon a wide range of disciplines from applied mathematics for the numerical solution of the equations to geomorphology for the physical interpretation of the results. In this light we organized this special issue (SI) soliciting multidisciplinary contributions which encompass any aspect needed for the development and applications of such models. Most of the papers in the SI stem from contributions to session HS9.5/GM7.11 on numerical modelling and experiments in river morphodynamics at the European Geosciences Union (EGU) General Assembly held in Vienna, April 27th to May 2nd 2014.

  14. A delta-rule model of numerical and non-numerical order processing.

    Science.gov (United States)

    Verguts, Tom; Van Opstal, Filip

    2014-06-01

    Numerical and non-numerical order processing share empirical characteristics (distance effect and semantic congruity), but there are also important differences (in size effect and end effect). At the same time, models and theories of numerical and non-numerical order processing developed largely separately. Currently, we combine insights from 2 earlier models to integrate them in a common framework. We argue that the same learning principle underlies numerical and non-numerical orders, but that environmental features determine the empirical differences. Implications for current theories on order processing are pointed out. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  15. Theoretical physics 8 statistical physics

    CERN Document Server

    Nolting, Wolfgang

    2018-01-01

    This textbook offers a clear and comprehensive introduction to statistical physics, one of the core components of advanced undergraduate physics courses. It follows on naturally from the previous volumes in this series, using methods of probability theory and statistics to solve physical problems. The first part of the book gives a detailed overview on classical statistical physics and introduces all mathematical tools needed. The second part of the book covers topics related to quantized states, gives a thorough introduction to quantum statistics, followed by a concise treatment of quantum gases. Ideally suited to undergraduate students with some grounding in quantum mechanics, the book is enhanced throughout with learning features such as boxed inserts and chapter summaries, with key mathematical derivations highlighted to aid understanding. The text is supported by numerous worked examples and end of chapter problem sets. About the Theoretical Physics series Translated from the renowned and highly successf...

  16. Numerical MHD study for plasmoid instability in uniform resistivity

    Science.gov (United States)

    Shimizu, Tohru; Kondoh, Koji; Zenitani, Seiji

    2017-11-01

    The plasmoid instability (PI) caused in uniform resistivity is numerically studied with a MHD numerical code of HLLD scheme. It is shown that the PI observed in numerical studies may often include numerical (non-physical) tearing instability caused by the numerical dissipations. By increasing the numerical resolutions, the numerical tearing instability gradually disappears and the physical tearing instability remains. Hence, the convergence of the numerical results is observed. Note that the reconnection rate observed in the numerical tearing instability can be higher than that of the physical tearing instability. On the other hand, regardless of the numerical and physical tearing instabilities, the tearing instability can be classified into symmetric and asymmetric tearing instability. The symmetric tearing instability tends to occur when the thinning of current sheet is stopped by the physical or numerical dissipations, often resulting in the drastic changes in plasmoid chain's structure and its activity. In this paper, by eliminating the numerical tearing instability, we could not specify the critical Lundquist number Sc beyond which PI is fully developed. It suggests that Sc does not exist, at least around S = 105.

  17. Numerical analysis of electromagnetic fields

    CERN Document Server

    Zhou Pei Bai

    1993-01-01

    Numerical methods for solving boundary value problems have developed rapidly. Knowledge of these methods is important both for engineers and scientists. There are many books published that deal with various approximate methods such as the finite element method, the boundary element method and so on. However, there is no textbook that includes all of these methods. This book is intended to fill this gap. The book is designed to be suitable for graduate students in engineering science, for senior undergraduate students as well as for scientists and engineers who are interested in electromagnetic fields. Objective Numerical calculation is the combination of mathematical methods and field theory. A great number of mathematical concepts, principles and techniques are discussed and many computational techniques are considered in dealing with practical problems. The purpose of this book is to provide students with a solid background in numerical analysis of the field problems. The book emphasizes the basic theories ...

  18. Cosmoparticle physics

    CERN Document Server

    Khlopov, M Yu

    1999-01-01

    Since the 1980s the cross-disciplinary, multidimensional field of links between cosmology and particle physics has been widely recognised by theorists, studying cosmology, particle and nuclear physics, gravity, as well as by astrophysicists, astronomers, space physicists, experimental particle and nuclear physicists, mathematicians and engineers.The relationship between cosmology and particle physics is now one of the important topics of discussion at any scientific meeting both on astrophysics and high energy physics.Cosmoparticle physics is the result of the mutual relationship between cosmo

  19. 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,...

  20. Physical mathematics

    CERN Document Server

    Cahill, Kevin

    2013-01-01

    Unique in its clarity, examples and range, Physical Mathematics explains as simply as possible the mathematics that graduate students and professional physicists need in their courses and research. The author illustrates the mathematics with numerous physical examples drawn from contemporary research. In addition to basic subjects such as linear algebra, Fourier analysis, complex variables, differential equations and Bessel functions, this textbook covers topics such as the singular-value decomposition, Lie algebras, the tensors and forms of general relativity, the central limit theorem and Kolmogorov test of statistics, the Monte Carlo methods of experimental and theoretical physics, the renormalization group of condensed-matter physics and the functional derivatives and Feynman path integrals of quantum field theory.

  1. Learning SciPy for numerical and scientific computing

    CERN Document Server

    Silva

    2013-01-01

    A step-by-step practical tutorial with plenty of examples on research-based problems from various areas of science, that prove how simple, yet effective, it is to provide solutions based on SciPy. This book is targeted at anyone with basic knowledge of Python, a somewhat advanced command of mathematics/physics, and an interest in engineering or scientific applications---this is broadly what we refer to as scientific computing.This book will be of critical importance to programmers and scientists who have basic Python knowledge and would like to be able to do scientific and numerical computatio

  2. Fast reactor physics - an overview

    International Nuclear Information System (INIS)

    Lee, S.M.

    2004-01-01

    An introduction to the basic features of fast neutron reactors is made, highlighting the differences from the more conventional thermal neutron reactors. A discussion of important feedback reactivity mechanisms is given. Then an overview is presented of the methods of fast reactor physics, which play an important role in the successful design and operation of fast reactors. The methods are based on three main elements, namely (i) nuclear data bases, (ii) numerical methods and computer codes, and (iii) critical experiments. These elements are reviewed and the present status and future trends are summarized. (author)

  3. Numerical simulation of single bubble boiling behavior

    Directory of Open Access Journals (Sweden)

    Junjie Liu

    2017-06-01

    Full Text Available The phenomena of a single bubble boiling process are studied with numerical modeling. The mass, momentum, energy and level set equations are solved using COMSOL multi-physics software. The bubble boiling dynamics, the transient pressure field, velocity field and temperature field in time are analyzed, and reasonable results are obtained. The numeral model is validated by the empirical equation of Fritz and could be used for various applications.

  4. Nuclear physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

    Explains the concepts in detail and in depth. Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook explains the experimental basics, effects and theory of nuclear physics. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams help to better understand the explanations. A better feeling to the subject of the book is given with sketches about the historical development of nuclear physics. The main topics of this book include the phenomena associated with passage of charged particles and radiation through matter which are related to nuclear resonance fluorescence and the Moessbauer effect., Gamov's theory of alpha decay, Fermi theory of beta decay, electron capture and gamma decay. The discussion of general properties of nuclei covers nuclear sizes and nuclear force, nuclear spin, magnetic dipole moment and electric quadrupole moment. Nuclear instability against various modes of decay and Yukawa theory are explained. Nuclear models such as Fermi Gas Model, Shell Model, Liquid Drop Model, Collective Model and Optical Model are outlined to explain various experimental facts related to nuclear structure. Heavy ion reactions, including nuclear fusion, are explained. Nuclear fission and fusion power production is treated elaborately.

  5. EDITORIAL: Physics competitions Physics competitions

    Science.gov (United States)

    Jordens, H.; Mathelitsch, L.

    2009-11-01

    students are allowed to use any method they like, are coached by teachers, and are encouraged to ask for help from experts at research centres or universities. Finally, they must prepare a 12-minute presentation. A tournament consists of different contests. In each contest, three teams are involved: the reporting team is challenged by an opponent team to present a task. This presentation is then criticized by the opponent, pointing out merits and possible weak parts. The discussion between the two representatives of the teams is a central element of a contest. The third team acts as reviewer, giving final comments on the performances of the contesting teams. At the end, a jury grades the performances of all three teams. Then, the different roles of the teams rotate, and the students also rotate roles within the teams. The competition started in the former Soviet Union in 1988 and became international for the first time in 1994 when it was organized in Groningen, The Netherlands. In the 2008 tournament in Trogir, Croatia, teams from 24 countries participated [5]. Since this tournament is younger and less known, the national pre-selections are not as well established and numerous as for the Olympiad. Also, the training is different: in addition to developing experimental skills and physical understanding of the problems, the students must organize their performances, share work and responsibilities, and must train in the techniques of presentation and debate (in English). The winner of the tournament in Croatia was the team from Germany. Their presentation in the finals was an experimental and theoretical investigation into the Kaye effect. The students wrote up their presentation, and it is reproduced here as the second paper in this special section. Again, different in spirit and aim is 'First Step to Nobel Prize in Physics' [6]. This competition started in 1991 in Poland and encourages students to take their first steps in physics research. Students of 20 years old or

  6. Numerical Relativity Simulations for Black Hole Merger Astrophysics

    Science.gov (United States)

    Baker, John G.

    2010-01-01

    Massive black hole mergers are perhaps the most energetic astronomical events, establishing their importance as gravitational wave sources for LISA, and also possibly leading to observable influences on their local environments. Advances in numerical relativity over the last five years have fueled the development of a rich physical understanding of general relativity's predictions for these events. Z will overview the understanding of these event emerging from numerical simulation studies. These simulations elucidate the pre-merger dynamics of the black hole binaries, the consequent gravitational waveform signatures ' and the resulting state, including its kick velocity, for the final black hole produced by the merger. Scenarios are now being considered for observing each of these aspects of the merger, involving both gravitational-wave and electromagnetic astronomy.

  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. Find a Physical Therapist

    Science.gov (United States)

    ... our resources for healthy running. Go There » Why Physical Therapy? Avoid Opioids Benefits of Physical Therapy About PTs & PTAs Did You Know? Patient ... There are numerous benefits to treatment by a physical therapist. Go There » For Patients Choosing Your PT ...

  9. Strongly correlated systems numerical methods

    CERN Document Server

    Mancini, Ferdinando

    2013-01-01

    This volume presents, for the very first time, an exhaustive collection of those modern numerical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and material science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciate consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as possi...

  10. Development of numerical processing in children with typical and dyscalculic arithmetic skills—a longitudinal study

    Science.gov (United States)

    Landerl, Karin

    2013-01-01

    Numerical processing has been demonstrated to be closely associated with arithmetic skills, however, our knowledge on the development of the relevant cognitive mechanisms is limited. The present longitudinal study investigated the developmental trajectories of numerical processing in 42 children with age-adequate arithmetic development and 41 children with dyscalculia over a 2-year period from beginning of Grade 2, when children were 7; 6 years old, to beginning of Grade 4. A battery of numerical processing tasks (dot enumeration, non-symbolic and symbolic comparison of one- and two-digit numbers, physical comparison, number line estimation) was given five times during the study (beginning and middle of each school year). Efficiency of numerical processing was a very good indicator of development in numerical processing while within-task effects remained largely constant and showed low long-term stability before middle of Grade 3. Children with dyscalculia showed less efficient numerical processing reflected in specifically prolonged response times. Importantly, they showed consistently larger slopes for dot enumeration in the subitizing range, an untypically large compatibility effect when processing two-digit numbers, and they were consistently less accurate in placing numbers on a number line. Thus, we were able to identify parameters that can be used in future research to characterize numerical processing in typical and dyscalculic development. These parameters can also be helpful for identification of children who struggle in their numerical development. PMID:23898310

  11. Development of numerical processing in children with typical and dyscalculic arithmetic skills – a longitudinal study

    Directory of Open Access Journals (Sweden)

    Karin eLanderl

    2013-07-01

    Full Text Available Numerical processing has been demonstrated to be closely associated with arithmetic skills, however, our knowledge on the development of the relevant cognitive mechanisms is limited. The present longitudinal study investigated the developmental trajectories of numerical processing in 42 children with age-adequate arithmetic development and 41 children with dyscalculia over a two-year period from beginning of Grade 2, when children were 7;6 years old, to beginning of Grade 4. A battery of numerical processing tasks (dot enumeration, non-symbolic and symbolic comparison of one- and two-digit numbers, physical comparison, number line estimation was given five times during the study (beginning and middle of each school year. Efficiency of numerical processing was a very good indicator of development in numerical processing while within-task effects remained largely constant and showed low long-term stability before middle of Grade 3. Children with dyscalculia showed less efficient numerical processing reflected in specifically prolonged response times. Importantly, they showed consistently larger slopes for dot enumeration in the subitizing range, an untypically large compatibility effect when processing two-digit numbers, and they were consistently less accurate in placing numbers on a number line. Thus, we were able to identify parameters that can be used in future research to characterize numerical processing in typical and dyscalculic development. These parameters can also be helpful for identification of children who struggle in their numerical development.

  12. Numerical studies of the linear theta pinch

    International Nuclear Information System (INIS)

    Brackbill, J.U.; Menzel, M.T.; Barnes, D.C.

    1975-01-01

    Aspects of several physical problems associated with linear theta pinches were studied using recently developed numerical methods for the solution of the nonlinear equations for time-dependent magnetohydrodynamic flow in two- and three-dimensions. The problems studied include the propagation of end-loss produced rarefaction waves, the flow produced in a proposed injection experiment geometry, and the linear growth and nonlinear saturation of instabilities in rotating plasmas, all in linear geometries. The studies illustrate how numerical computations aid in flow visualization, and how the small amplitude behavior and nonlinear fate of plasmas in unstable equilibria can be connected through the numerical solution of the dynamical equations. (auth)

  13. Numerical verification of equilibrium chemistry software within nuclear fuel performance codes

    International Nuclear Information System (INIS)

    Piro, M.H.; Lewis, B.J.; Thompson, W.T.; Simunovic, S.; Besmann, T.M.

    2010-01-01

    A numerical tool is in an advanced state of development to compute the equilibrium compositions of phases and their proportions in multi-component systems of importance to the nuclear industry. The resulting software is being conceived for direct integration into large multi-physics fuel performance codes, particularly for providing transport source terms, material properties, and boundary conditions in heat and mass transport modules. Consequently, any numerical errors produced in equilibrium chemistry computations will be propagated in subsequent heat and mass transport calculations, thus falsely predicting nuclear fuel behaviour. The necessity for a reliable method to numerically verify chemical equilibrium computations is emphasized by the requirement to handle the very large number of elements necessary to capture the entire fission product inventory. A simple, reliable and comprehensive numerical verification method called the Gibbs Criteria is presented which can be invoked by any equilibrium chemistry solver for quality assurance purposes. (author)

  14. Numerical distance protection

    CERN Document Server

    Ziegler, Gerhard

    2011-01-01

    Distance protection provides the basis for network protection in transmission systems and meshed distribution systems. This book covers the fundamentals of distance protection and the special features of numerical technology. The emphasis is placed on the application of numerical distance relays in distribution and transmission systems.This book is aimed at students and engineers who wish to familiarise themselves with the subject of power system protection, as well as the experienced user, entering the area of numerical distance protection. Furthermore it serves as a reference guide for s

  15. Force-controlled absorption in a fully-nonlinear numerical wave tank

    International Nuclear Information System (INIS)

    Spinneken, Johannes; Christou, Marios; Swan, Chris

    2014-01-01

    An active control methodology for the absorption of water waves in a numerical wave tank is introduced. This methodology is based upon a force-feedback technique which has previously been shown to be very effective in physical wave tanks. Unlike other methods, an a-priori knowledge of the wave conditions in the tank is not required; the absorption controller being designed to automatically respond to a wide range of wave conditions. In comparison to numerical sponge layers, effective wave absorption is achieved on the boundary, thereby minimising the spatial extent of the numerical wave tank. In contrast to the imposition of radiation conditions, the scheme is inherently capable of absorbing irregular waves. Most importantly, simultaneous generation and absorption can be achieved. This is an important advance when considering inclusion of reflective bodies within the numerical wave tank. In designing the absorption controller, an infinite impulse response filter is adopted, thereby eliminating the problem of non-causality in the controller optimisation. Two alternative controllers are considered, both implemented in a fully-nonlinear wave tank based on a multiple-flux boundary element scheme. To simplify the problem under consideration, the present analysis is limited to water waves propagating in a two-dimensional domain. The paper presents an extensive numerical validation which demonstrates the success of the method for a wide range of wave conditions including regular, focused and random waves. The numerical investigation also highlights some of the limitations of the method, particularly in simultaneously generating and absorbing large amplitude or highly-nonlinear waves. The findings of the present numerical study are directly applicable to related fields where optimum absorption is sought; these include physical wavemaking, wave power absorption and a wide range of numerical wave tank schemes

  16. Excel spreadsheet in teaching numerical methods

    Science.gov (United States)

    Djamila, Harimi

    2017-09-01

    One of the important objectives in teaching numerical methods for undergraduates’ students is to bring into the comprehension of numerical methods algorithms. Although, manual calculation is important in understanding the procedure, it is time consuming and prone to error. This is specifically the case when considering the iteration procedure used in many numerical methods. Currently, many commercial programs are useful in teaching numerical methods such as Matlab, Maple, and Mathematica. These are usually not user-friendly by the uninitiated. Excel spreadsheet offers an initial level of programming, which it can be used either in or off campus. The students will not be distracted with writing codes. It must be emphasized that general commercial software is required to be introduced later to more elaborated questions. This article aims to report on a teaching numerical methods strategy for undergraduates engineering programs. It is directed to students, lecturers and researchers in engineering field.

  17. Large scale experiments as a tool for numerical model development

    DEFF Research Database (Denmark)

    Kirkegaard, Jens; Hansen, Erik Asp; Fuchs, Jesper

    2003-01-01

    Experimental modelling is an important tool for study of hydrodynamic phenomena. The applicability of experiments can be expanded by the use of numerical models and experiments are important for documentation of the validity of numerical tools. In other cases numerical tools can be applied...

  18. Remarks on numerical semigroups

    International Nuclear Information System (INIS)

    Torres, F.

    1995-12-01

    We extend results on Weierstrass semigroups at ramified points of double covering of curves to any numerical semigroup whose genus is large enough. As an application we strengthen the properties concerning Weierstrass weights state in [To]. (author). 25 refs

  19. Numerical semigroups and applications

    CERN Document Server

    Assi, Abdallah

    2016-01-01

    This work presents applications of numerical semigroups in Algebraic Geometry, Number Theory, and Coding Theory. Background on numerical semigroups is presented in the first two chapters, which introduce basic notation and fundamental concepts and irreducible numerical semigroups. The focus is in particular on free semigroups, which are irreducible; semigroups associated with planar curves are of this kind. The authors also introduce semigroups associated with irreducible meromorphic series, and show how these are used in order to present the properties of planar curves. Invariants of non-unique factorizations for numerical semigroups are also studied. These invariants are computationally accessible in this setting, and thus this monograph can be used as an introduction to Factorization Theory. Since factorizations and divisibility are strongly connected, the authors show some applications to AG Codes in the final section. The book will be of value for undergraduate students (especially those at a higher leve...

  20. Advances in Numerical Methods

    CERN Document Server

    Mastorakis, Nikos E

    2009-01-01

    Features contributions that are focused on significant aspects of current numerical methods and computational mathematics. This book carries chapters that advanced methods and various variations on known techniques that can solve difficult scientific problems efficiently.

  1. Introductory numerical analysis

    CERN Document Server

    Pettofrezzo, Anthony J

    2006-01-01

    Written for undergraduates who require a familiarity with the principles behind numerical analysis, this classical treatment encompasses finite differences, least squares theory, and harmonic analysis. Over 70 examples and 280 exercises. 1967 edition.

  2. Introduction to numerical analysis

    CERN Document Server

    Hildebrand, F B

    1987-01-01

    Well-known, respected introduction, updated to integrate concepts and procedures associated with computers. Computation, approximation, interpolation, numerical differentiation and integration, smoothing of data, other topics in lucid presentation. Includes 150 additional problems in this edition. Bibliography.

  3. Nuclear Physics in Poland

    International Nuclear Information System (INIS)

    Wroblewski, A.K.

    2004-01-01

    Full text: This will be a short presentation of low and high energy nuclear physics in Poland, its history, essential results, and the present status. Nuclear physics in Poland has a tradition of hundred years. Research started just after the discovery of radium and polonium by Polish-born Maria Sklodowska-Curie and her husband Pierre Curie. Maria Sklodowska-Curie employed numerous Polish assistants in her Paris laboratory and supported radioactivity studies in Warsaw, her birth place, then under the occupation of tsarist Russia. In the first decades of the XXth century Poland was one of the leading countries in radioactivity studies. In the late 1930-ies a cyclotron was constructed in Warsaw and an ambitious 'Star of Poland' project was launched to study the cosmic rays. Unfortunately, the Second World War stopped all scientific activity in Poland. A large fraction of Polish physicists perished in the period 1939-1945. After the World War nuclear physics of low and high energy was rebuilt in Warsaw and Krakow. Already in 1952 Marian Danysz and Jerzy Pniewski discovered the first hypernucleus. This important discovery was essential to understand the properties of numerous new particles found in cosmic rays. Polish physicists entered intensive collaboration with both CERN and Dubna and took part also in research at other centers in Europe (DESY, GSI, GANIL, Julich, SACLAY) and the United States (Fermilab). At present the research is concentrated in Warsaw and Krakow (the two largest centers), and smaller teams, mostly theorists, are also in Bialystok, Katowice, Kielce, Lublin, Lodz and Wroclaw. Several years ago a heavy ion cyclotron was built in Warsaw. Among the important discoveries made by Polish nuclear physicists one may mention the theoretical works on superheavy elements and the recent discovery of the two-proton radioactivity

  4. Numerical computations with GPUs

    CERN Document Server

    Kindratenko, Volodymyr

    2014-01-01

    This book brings together research on numerical methods adapted for Graphics Processing Units (GPUs). It explains recent efforts to adapt classic numerical methods, including solution of linear equations and FFT, for massively parallel GPU architectures. This volume consolidates recent research and adaptations, covering widely used methods that are at the core of many scientific and engineering computations. Each chapter is written by authors working on a specific group of methods; these leading experts provide mathematical background, parallel algorithms and implementation details leading to

  5. Numerical simulation of TIG welding with filler of steel pieces of high thickness

    International Nuclear Information System (INIS)

    Carmignani, B.; Toselli, G.

    1999-01-01

    The problem of the numerical simulation of welding process with filler, in particular TIG (tungsten inert gas) with cold filler, has been approached with ABAQUS/S code. Reference has been made to some experimental models studied and prepared ad hoc in order to better know the physical phenomena involved in the TIG welding technique and to validate the computation methodologies and results obtained. This numerical simulation has been required in order to assist the fabrication development and QA for TF (toroidal field) coil case, an important component of ITER (international thermonuclear experimental reactor) machine [it

  6. Dystonia: Physical Therapy

    Science.gov (United States)

    ... Online Support Frequently Asked Questions Faces of Dystonia Physical Therapy Physical therapy may be an important component of treating ... everyday tasks, Since dystonia is a neurological disorder, physical therapy does not treat the dystonia directly but ...

  7. Guide to Physical Activity

    Science.gov (United States)

    ... Families ( We Can! ) Health Professional Resources Guide to Physical Activity Physical activity is an important part of your ... to injury. Examples of moderate-intensity amounts of physical activity Common Chores Washing and waxing a car for ...

  8. Theoretical and numerical study of highly anisotropic turbulent flows

    NARCIS (Netherlands)

    Biferale, L.; Daumont, I.; Lanotte, A.; Toschi, F.

    2004-01-01

    We present a detailed numerical study of anisotropic statistical fluctuations in stationary, homogeneous turbulent flows. We address both problems of intermittency in anisotropic sectors, and the relative importance of isotropic and anisotropic fluctuations at different scales on a direct numerical

  9. Numerical and Evolutionary Optimization Workshop

    CERN Document Server

    Trujillo, Leonardo; Legrand, Pierrick; Maldonado, Yazmin

    2017-01-01

    This volume comprises a selection of works presented at the Numerical and Evolutionary Optimization (NEO) workshop held in September 2015 in Tijuana, Mexico. The development of powerful search and optimization techniques is of great importance in today’s world that requires researchers and practitioners to tackle a growing number of challenging real-world problems. In particular, there are two well-established and widely known fields that are commonly applied in this area: (i) traditional numerical optimization techniques and (ii) comparatively recent bio-inspired heuristics. Both paradigms have their unique strengths and weaknesses, allowing them to solve some challenging problems while still failing in others. The goal of the NEO workshop series is to bring together people from these and related fields to discuss, compare and merge their complimentary perspectives in order to develop fast and reliable hybrid methods that maximize the strengths and minimize the weaknesses of the underlying paradigms. Throu...

  10. Numerical methods in nuclear engineering. Part 1

    International Nuclear Information System (INIS)

    Phillips, G.J.

    1983-08-01

    These proceedings, published in two parts contain the full text of 56 papers and summaries of six papers presented at the conference. They cover the use of numerical methods in thermal hydraulics, reactor physics, neutron diffusion, subchannel analysis, risk assessment, transport theory, and fuel behaviour

  11. Numerical methods and analysis of multiscale problems

    CERN Document Server

    Madureira, Alexandre L

    2017-01-01

    This book is about numerical modeling of multiscale problems, and introduces several asymptotic analysis and numerical techniques which are necessary for a proper approximation of equations that depend on different physical scales. Aimed at advanced undergraduate and graduate students in mathematics, engineering and physics – or researchers seeking a no-nonsense approach –, it discusses examples in their simplest possible settings, removing mathematical hurdles that might hinder a clear understanding of the methods. The problems considered are given by singular perturbed reaction advection diffusion equations in one and two-dimensional domains, partial differential equations in domains with rough boundaries, and equations with oscillatory coefficients. This work shows how asymptotic analysis can be used to develop and analyze models and numerical methods that are robust and work well for a wide range of parameters.

  12. Smart tailoring of real-time physical activity coaching systems

    NARCIS (Netherlands)

    op den Akker, Harm

    2014-01-01

    The lack of physical activity in the general population is recognized internationally as an important societal issue. For apparently healthy adults, inactivity leads to overweight, and increased risk of numerous chronic and acute diseases including coronary heart disease, type 2 diabetes, as well as

  13. Exercise: A vitally important prescription.

    Science.gov (United States)

    Hechanova, Rachel L; Wegler, Jennifer L; Forest, Christopher P

    2017-04-01

    Sedentary lifestyles and low physical activity have led to rising health concerns and increasing mortality risks. With the growing concern of the inactivity of adult Americans, it is important that physical activity be promoted to prevent disease and reduce health risks. This article reviews the benefits of physical activity and the steps that primary care providers should take to evaluate physical activity as the fifth vital sign in every patient encounter. The 5A's (assess, advise, agree, assist, and arrange) should be applied in order to implement an exercise prescription into the practice of medicine.

  14. Probabilistic numerics and uncertainty in computations.

    Science.gov (United States)

    Hennig, Philipp; Osborne, Michael A; Girolami, Mark

    2015-07-08

    We deliver a call to arms for probabilistic numerical methods : algorithms for numerical tasks, including linear algebra, integration, optimization and solving differential equations, that return uncertainties in their calculations. Such uncertainties, arising from the loss of precision induced by numerical calculation with limited time or hardware, are important for much contemporary science and industry. Within applications such as climate science and astrophysics, the need to make decisions on the basis of computations with large and complex data have led to a renewed focus on the management of numerical uncertainty. We describe how several seminal classic numerical methods can be interpreted naturally as probabilistic inference. We then show that the probabilistic view suggests new algorithms that can flexibly be adapted to suit application specifics, while delivering improved empirical performance. We provide concrete illustrations of the benefits of probabilistic numeric algorithms on real scientific problems from astrometry and astronomical imaging, while highlighting open problems with these new algorithms. Finally, we describe how probabilistic numerical methods provide a coherent framework for identifying the uncertainty in calculations performed with a combination of numerical algorithms (e.g. both numerical optimizers and differential equation solvers), potentially allowing the diagnosis (and control) of error sources in computations.

  15. A student's guide to Python for physical modeling

    CERN Document Server

    Kinder, Jesse M

    2015-01-01

    Python is a computer programming language that is rapidly gaining popularity throughout the sciences. A Student’s Guide to Python for Physical Modeling aims to help you, the student, teach yourself enough of the Python programming language to get started with physical modeling. You will learn how to install an open-source Python programming environment and use it to accomplish many common scientific computing tasks: importing, exporting, and visualizing data; numerical analysis; and simulation. No prior programming experience is assumed. This tutorial focuses on fundamentals and introduces a wide range of useful techniques, including: Basic Python programming and scripting Numerical arrays Two- and three-dimensional graphics Monte Carlo simulations Numerical methods, including solving ordinary differential equations Image processing Animation Numerous code samples and exercises—with solutions—illustrate new ideas as they are introduced. A website that accompanies this guide provides additional resourc...

  16. Numerical models for high beta magnetohydrodynamic flow

    International Nuclear Information System (INIS)

    Brackbill, J.U.

    1987-01-01

    The fundamentals of numerical magnetohydrodynamics for highly conducting, high-beta plasmas are outlined. The discussions emphasize the physical properties of the flow, and how elementary concepts in numerical analysis can be applied to the construction of finite difference approximations that capture these features. The linear and nonlinear stability of explicit and implicit differencing in time is examined, the origin and effect of numerical diffusion in the calculation of convective transport is described, and a technique for maintaining solenoidality in the magnetic field is developed. Many of the points are illustrated by numerical examples. The techniques described are applicable to the time-dependent, high-beta flows normally encountered in magnetically confined plasmas, plasma switches, and space and astrophysical plasmas. 40 refs

  17. Visualization of numerically simulated aerodynamic flow fields

    International Nuclear Information System (INIS)

    Hian, Q.L.; Damodaran, M.

    1991-01-01

    The focus of this paper is to describe the development and the application of an interactive integrated software to visualize numerically simulated aerodynamic flow fields so as to enable the practitioner of computational fluid dynamics to diagnose the numerical simulation and to elucidate essential flow physics from the simulation. The input to the software is the numerical database crunched by a supercomputer and typically consists of flow variables and computational grid geometry. This flow visualization system (FVS), written in C language is targetted at the Personal IRIS Workstations. In order to demonstrate the various visualization modules, the paper also describes the application of this software to visualize two- and three-dimensional flow fields past aerodynamic configurations which have been numerically simulated on the NEC-SXIA Supercomputer. 6 refs

  18. Development of Pelton turbine using numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Patel, K; Patel, B; Yadav, M [Hydraulic Engineer, ALSTOM Hydro R and D India Ltd., GIDC Maneja, Vadodara - 390 013, Gujarat (India); Foggia, T, E-mail: patel@power.alstom.co [Hydraulic Engineer, Alstom Hydro France, Etablissement de Grenoble, 82, avenue Leon Blum BP 75, 38041 Grenoble Cedex (France)

    2010-08-15

    This paper describes recent research and development activities in the field of Pelton turbine design. Flow inside Pelton turbine is most complex due to multiphase (mixture of air and water) and free surface in nature. Numerical calculation is useful to understand flow physics as well as effect of geometry on flow. The optimized design is obtained using in-house special optimization loop. Either single phase or two phase unsteady numerical calculation could be performed. Numerical results are used to visualize the flow pattern in the water passage and to predict performance of Pelton turbine at full load as well as at part load. Model tests are conducted to determine performance of turbine and it shows good agreement with numerically predicted performance.

  19. Development of Pelton turbine using numerical simulation

    Science.gov (United States)

    Patel, K.; Patel, B.; Yadav, M.; Foggia, T.

    2010-08-01

    This paper describes recent research and development activities in the field of Pelton turbine design. Flow inside Pelton turbine is most complex due to multiphase (mixture of air and water) and free surface in nature. Numerical calculation is useful to understand flow physics as well as effect of geometry on flow. The optimized design is obtained using in-house special optimization loop. Either single phase or two phase unsteady numerical calculation could be performed. Numerical results are used to visualize the flow pattern in the water passage and to predict performance of Pelton turbine at full load as well as at part load. Model tests are conducted to determine performance of turbine and it shows good agreement with numerically predicted performance.

  20. Development of Pelton turbine using numerical simulation

    International Nuclear Information System (INIS)

    Patel, K; Patel, B; Yadav, M; Foggia, T

    2010-01-01

    This paper describes recent research and development activities in the field of Pelton turbine design. Flow inside Pelton turbine is most complex due to multiphase (mixture of air and water) and free surface in nature. Numerical calculation is useful to understand flow physics as well as effect of geometry on flow. The optimized design is obtained using in-house special optimization loop. Either single phase or two phase unsteady numerical calculation could be performed. Numerical results are used to visualize the flow pattern in the water passage and to predict performance of Pelton turbine at full load as well as at part load. Model tests are conducted to determine performance of turbine and it shows good agreement with numerically predicted performance.