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Sample records for collisions theory review

  1. High energy nuclear collisions: theory review

    Fries, Rainer J.

    2009-01-01

    Full text: High Energy Nuclear Collisions are studied at the Relativistic Heavy Ion Collider (RHIC) and, starting next year, also at the Large Hadron Collider (LHC) to study the formation and properties of quark gluon plasma (QGP). This effort is driven by the prediction that above a certain critical temperature quarks and gluons are deconfined. For the past ten years of running RHIC has performed marvelously. Data from RHIC has answered many initial questions, but it has also provided new, more challenging problems to understand the nature of quark gluon plasma and the dynamics of heavy ion collisions. In this talk I review some of the basic concepts of high energy nuclear collisions and quark gluon plasma formation. We also discuss some of the novel and open questions that we are faced with. We discuss recent predictions on properties of hot quantum chromodynamics, emerging signatures for the color glass condensate, the fascinating idea of local P and CP violation in QCD, as well as ongoing research on hard probes and electromagnetic signatures

  2. Molecular collision theory

    Child, M S

    2010-01-01

    This high-level monograph offers an excellent introduction to the theory required for interpretation of an increasingly sophisticated range of molecular scattering experiments. There are five helpful appendixes dealing with continuum wavefunctions, Green's functions, semi-classical connection formulae, curve-crossing in the momentum representation, and elements of classical mechanics.The contents of this volume have been chosen to emphasize the quantum mechanical and semi-classical nature of collision events, with little attention given to purely classical behavior. The treatment is essentiall

  3. Relativistic nuclear collisions: theory

    Gyulassy, M.

    1980-07-01

    Some of the recent theoretical developments in relativistic (0.5 to 2.0-GeV/nucleon) nuclear collisions are reviewed. The statistical model, hydrodynamic model, classical equation of motion calculations, billiard ball dynamics, and intranuclear cascade models are discussed in detail. Inclusive proton and pion spectra are analyzed for a variety of reactions. Particular attention is focused on how the complex interplay of the basic reaction mechanism hinders attempts to deduce the nuclear matter equation of state from data. 102 references, 19 figures

  4. Topics in atomic collision theory

    Geltman, Sydney; Brueckner, Keith A

    1969-01-01

    Topics in Atomic Collision Theory originated in a course of graduate lectures given at the University of Colorado and at University College in London. It is recommended for students in physics and related fields who are interested in the application of quantum scattering theory to low-energy atomic collision phenomena. No attention is given to the electromagnetic, nuclear, or elementary particle domains. The book is organized into three parts: static field scattering, electron-atom collisions, and atom-atom collisions. These are in the order of increasing physical complexity and hence necessar

  5. Holographic collisions in confining theories

    Cardoso, Vitor; Emparan, Roberto; Mateos, David; Pani, Paolo; Rocha, Jorge V.

    2014-01-01

    We study the gravitational dual of a high-energy collision in a confining gauge theory. We consider a linearized approach in which two point particles traveling in an AdS-soliton background suddenly collide to form an object at rest (presumably a black hole for large enough center-of-mass energies). The resulting radiation exhibits the features expected in a theory with a mass gap: late-time power law tails of the form t −3/2 , the failure of Huygens’ principle and distortion of the wave pattern as it propagates. The energy spectrum is exponentially suppressed for frequencies smaller than the gauge theory mass gap. Consequently, we observe no memory effect in the gravitational waveforms. At larger frequencies the spectrum has an upward-stairway structure, which corresponds to the excitation of the tower of massive states in the confining gauge theory. We discuss the importance of phenomenological cutoffs to regularize the divergent spectrum, and the aspects of the full non-linear collision that are expected to be captured by our approach

  6. Theory of low energy collisions

    Sparenberg, J.M.

    2007-01-01

    The basic notions of low-energy quantum scattering theory are introduced (cross sections, phase shifts, resonances,... ), in particular for positively-charged particles, in view of nuclear physics applications. An introduction to the reaction-matrix (or R-matrix) method is then proposed, as a tool to both solve the Schroedinger equation describing collisions and fit experimental data phenomenologically. Most results are established without proof but with a particular emphasis on their intuitive understanding and their possible analogs in classical mechanics. Several choices are made consequently: (i) the text starts with a detailed reminder of classical scattering theory, (ii) the concepts are first introduced in ideal theoretical cases before going to the more complicated formalism allowing the description of realistic experimental situations, (iii) a single example is used throughout nearly the whole text, (iv) all concepts are established for the elastic scattering of spinless particles, with only a brief mention of their multichannel generalization at the end of the text. (author)

  7. Weak values in collision theory

    de Castro, Leonardo Andreta; Brasil, Carlos Alexandre; Napolitano, Reginaldo de Jesus

    2018-05-01

    Weak measurements have an increasing number of applications in contemporary quantum mechanics. They were originally described as a weak interaction that slightly entangled the translational degrees of freedom of a particle to its spin, yielding surprising results after post-selection. That description often ignores the kinetic energy of the particle and its movement in three dimensions. Here, we include these elements and re-obtain the weak values within the context of collision theory by two different approaches, and prove that the results are compatible with each other and with the results from the traditional approach. To provide a more complete description, we generalize weak values into weak tensors and use them to provide a more realistic description of the Stern-Gerlach apparatus.

  8. Nonrelativistic theory of heavy-ion collisions

    Bertsch, G.

    1984-01-01

    A wide range of phenomena is observed in heavy-ion collisions, calling for a comprehensive theory based on fundamental principles of many-particle quantum mechanics. At low energies, the nuclear dynamics is controlled by the mean field, as we know from spectroscopic nuclear physics. We therefore expect the comprehensive theory of collisions to contain mean-field theory at low energies. The mean-field theory is the subject of the first lectures in this chapter. This theory can be studied quantum mechanically, in which form it is called TDHF (time-dependent Hartree-Fock), or classically, where the equation is called the Vlasov equation. 25 references, 14 figures

  9. Advances in ultracold collisions: Experimentation and theory

    Weiner, J.

    1995-01-01

    Collisions between optically cooled and trapped atoms have been the subject of intensive investigation since early proposals discussed their novel features and key importance to the achievement of a gaseous ensemble in a single quantum state. Progress in both experimentation and theory has accelerated rapidly over the last three years, and two reviews, one emphasizing theory and the other, experiments, recount the state of the art published up to about the midpoint of 1993. The purpose of this chapter is to update continuing lines of research set forth in these and earlier works and to relate new results, establishing novel directions for investigation that have appeared in the literature. Two principal questions motivate research into the nature of ultracold collisions: (1) what new phenomena arise when collisionally interacting particles also exchange photons with modes of the radiation field and (2) what are the important two-body collisional heating mechanisms and how can they be overcome in order to achieve the temperature and density conditions appropriate for Bose-Einstein condensation (BEC)? In fact these two questions are not mutually exclusive, and one of the most notable developments in the past year, relevant to both, has been the demonstration of optical control of two-body ultracold collisional processes. Other important issues touching, on one or both of these questions are the magnitude and sign of the scattering length in s-wave collisions between species in various well-defined quantum states, progress in high-resolution trap loss and photoassociation spectroscopy, and application of optical cooling and compression to atomic beams. 58 refs., 21 figs

  10. Collisions engineering. Theory and applications

    Fremond, Michel [Rome ' ' Tor Vergata' ' Univ. (Italy). Dept. of Civil Engineering and Computer Science

    2017-02-01

    This book investigates collisions occurring in the motion of solids, in the motion of fluids but also in the motion of pedestrians in crowds. The duration of these presented collisions is short compared to the whole duration of the motion: they are assumed instantaneous. The innovative concept demonstrated in this book is that a system made of two solids, is deformable because their relative position changes. The definition of the velocities of deformation of the system introduced in the classical developments of mechanics, the principle of the virtual work and the laws of thermodynamics, allows a large range of applications such as crowd motions, debris flow motions, and shape memory alloys motions. The set of the applications is even larger: social sciences and mechanics are unified to predict the motion of crowds with application to transport management and to evacuation of theaters management.

  11. Collisions engineering. Theory and applications

    Fremond, Michel

    2017-01-01

    This book investigates collisions occurring in the motion of solids, in the motion of fluids but also in the motion of pedestrians in crowds. The duration of these presented collisions is short compared to the whole duration of the motion: they are assumed instantaneous. The innovative concept demonstrated in this book is that a system made of two solids, is deformable because their relative position changes. The definition of the velocities of deformation of the system introduced in the classical developments of mechanics, the principle of the virtual work and the laws of thermodynamics, allows a large range of applications such as crowd motions, debris flow motions, and shape memory alloys motions. The set of the applications is even larger: social sciences and mechanics are unified to predict the motion of crowds with application to transport management and to evacuation of theaters management.

  12. Collisions engineering theory and applications

    Frémond, Michel

    2017-01-01

    This book investigates collisions occurring in the motion of solids, in the motion of fluids but also in the motion of pedestrians in crowds. The duration of these presented collisions is short compared to the whole duration of the motion: they are assumed instantaneous. The innovative concept demonstrated in this book is that a system made of two solids, is deformable because their relative position changes. The definition of the velocities of deformation of the system introduced in the classical developments of mechanics, the principle of the virtual work and the laws of thermodynamics, allows a large range of applications such as crowd motions, debris flow motions, and shape memory alloys motions. The set of the applications is even larger: social sciences and mechanics are unified to predict the motion of crowds with application to transport management and to evacuation of theaters management.

  13. A new theory of collisions

    Giraud, B.G.

    1989-01-01

    Instead of diagonalizing the many-body Hamiltonian H, we invert E-H, where E is a complex energy, eventually real. All the traditional approximations to diagonalization can be adjusted to inversion. We specially investigate mean-field methods. This lecture gives a scheme for the detailed proofs of our arguments, already published, and lists several numerically soluble cases where our new method has been successfully tested for the calculation of collision amplitudes

  14. Holographic collisions in non-conformal theories

    Attems, Maximilian; Casalderrey-Solana, Jorge; Mateos, David; Santos-Oliván, Daniel; Sopuerta, Carlos F.; Triana, Miquel; Zilhão, Miguel

    2017-01-01

    We numerically simulate gravitational shock wave collisions in a holographic model dual to a non-conformal four-dimensional gauge theory. We find two novel effects associated to the non-zero bulk viscosity of the resulting plasma. First, the hydrodynamization time increases. Second, if the bulk viscosity is large enough then the plasma becomes well described by hydrodynamics before the energy density and the average pressure begin to obey the equilibrium equation of state. We discuss implications for the quark-gluon plasma created in heavy ion collision experiments.

  15. High energy nuclear collisions: Theory overview

    Fries, R.J.

    2010-08-01

    We review some basic concepts of relativistic heavy-ion physics and discuss our understanding of some key results from the experimental program at the relativistic heavy-ion collider (RHIC). We focus in particular on the early time dynamics of nuclear collisions, some result from lattice QCD, hard probes and photons.

  16. Theory of ion-atom collisions at high energy, I

    Watanabe, T.; Hino, K.

    1985-01-01

    Electron capture process by an ion from a neutral atom is one of the fundamental problems in the theory of atomic collision physics. Here a brief review is given mainly on the processes of non-radiative and radiative electron capture (charge transfer and REC). The main mechanism which govern the charge transfer process is introduced and the characteristic feature which is predicted by the theory is explained. As for the radiative electron capture process, after introducting the present theories, the full-quantum mechanical theoretical treatment is introduced. The theory leads a result which includes some inconsistency with formulae obtained by guage transformation. The relativistic quantum mechanical treatment is being tried in order to remove this inconsistency. The some results including mass and velocity dependence are reported and discussed. (author)

  17. Theory and Validation for the Collision Module

    Simonsen, Bo Cerup

    1999-01-01

    This report describes basic modelling principles, the theoretical background and validation examples for the Collision Module for the computer program DAMAGE.......This report describes basic modelling principles, the theoretical background and validation examples for the Collision Module for the computer program DAMAGE....

  18. Theory of low energy collisions; Theorie des collisions a basse energie

    Sparenberg, J.M. [Universite Libre de Bruxelles, Bruxelles (Belgium)

    2007-07-01

    The basic notions of low-energy quantum scattering theory are introduced (cross sections, phase shifts, resonances,... ), in particular for positively-charged particles, in view of nuclear physics applications. An introduction to the reaction-matrix (or R-matrix) method is then proposed, as a tool to both solve the Schroedinger equation describing collisions and fit experimental data phenomenologically. Most results are established without proof but with a particular emphasis on their intuitive understanding and their possible analogs in classical mechanics. Several choices are made consequently: (i) the text starts with a detailed reminder of classical scattering theory, (ii) the concepts are first introduced in ideal theoretical cases before going to the more complicated formalism allowing the description of realistic experimental situations, (iii) a single example is used throughout nearly the whole text, (iv) all concepts are established for the elastic scattering of spinless particles, with only a brief mention of their multichannel generalization at the end of the text. (author)

  19. The theory of relativistic heavy ion collisions

    1993-07-01

    This program began in January 1993. Its primary goals are studies of highly excited matter and its production in nuclear collisions at very high energies. After a general orientation on the project, abstracts describing the contents of completed papers and providing some details of current projects are given. Principal topics of interest are the following: the dynamics of nuclear collisions at very high energies (RHIC and LHC), the dynamics of nuclear collisions at AGS energies, high-temperature QCD and the physics of the quark-gluon plasma, and the production of strangelets and other rare objects

  20. B production in hadron collisions: Theory

    Berger, E.L.

    1989-01-01

    A review is presented of heavy quark production in bar pp, π - p, and pp interactions at fixed target and collider energies. Calculations of total cross sections and of single quark inclusive differential cross sections d 2 σ/dk T dy are described including contributions through next-to-leading order in QCD perturbation theory. Comparisons with available data on charm and bottom quark production show good agreement for reasonable values of the charm and bottom quark masses and other parameters. Predictions and open issues in the interpretation of results are summarized. 20 refs., 5 figs

  1. High energy nuclear collisions: Theory overview

    1012 K, were deconfined and existed as a quark gluon plasma (QGP). These ideas can be tested in collisions of nuclei at ultra-relativistic energies. At the relativistic heavy-ion collider (RHIC), nuclei as heavy as gold are accelerated to an energy of 100 GeV per nucleon. A total energy of 40 TeV is available in the collision of.

  2. Introduction to the theory of LHC collisions

    Mangano, Michelangelo L

    2015-01-01

    This chapter illustrates the basic principles underlying the use of perturbative QCD in predicting the structure of hard processes in high-energy hadronic collisions. It starts with a discussion of the factorization formula, which is the basis for the description of all hard processes in terms of universal functions parametrizing the density of quarks and gluons inside the proton. It then discusses the evolution of the perturbative final states, made of quarks and gluons, toward physical systems made of hadrons. Finally, several applications and examples of comparisons between the theoretical predictions and current data are presented. These provide a picture of the success of this theoretical framework, giving good confidence in the reliability of its future applications to the study of LHC collisions.

  3. Transport theory of dissipative heavy-ion collisions

    Norenberg, W.

    1979-01-01

    The lectures present the formulation of a transport theory, the derivation of a practicable transport equation (Fokker-Planck equation) and the evaluation of transport coefficients for dissipative (or deeply inelastic) heavy-ion collisions. The applicability of the theoretical concept is tested with remarkable success in the analyses of various experimental information (mass transfer, angular-momentum dissipation and energy loss). Some critical remarks on the present situation of transport theories are added. Future developments are outlined. (author)

  4. Transport theory of dissipative heavy-ion collisions

    Noerenberg, W.

    1979-03-01

    The lectures present the formulation of a transport theory, the derivation of a practicable transport equation (Fokker-Planck equation) and the evaluation of transport coefficients for dissipative (or deeply inelastic) heavyion collisions. The applicability of the theoretical concept is tested with remarkable success in the analyses of various experimental informations (mass transfer, angular-momentum dissipation and energy loss). Some critical remarks on the present situation of transport theories are added. Future developments are outlined. (orig.) [de

  5. Pragmatism and Practice Theory: Convergences or collisions

    Elkjaer, Bente; Buch, Anders

    of organizations. In this paper we want to spell out the theoretical similarities and divergences between practice theory and pragmatism to consider whether the two traditions can find common ground when gazing upon organization studies. We suggest that pragmatism should be included in the ‘tool-kit’ of practice......Proponents of the ‘practice turn’ in the social sciences rarely mention American pragmatism as a source of inspiration or refer to pragmatist philosophy. This strikes us as not only odd, but also a disadvantage since the pragmatist legacy has much to offer practice theory in the study...

  6. Recent developments in the theory of photon-photon collisions

    Brodsky, S.J.

    1984-09-01

    Over the past few years the field of photon-photon collisions has emerged as one of the best testing grounds for QCD, particularly in the area of exclusive and inclusive hard scattering processes, exotic resonance production, and detailed tests of the coupling of real and virtual photons to the quark current. In this summary of contributed papers, I will briefly review recent theoretical progress in the analysis of two-photon reactions and possible directions for future work. 29 references

  7. Stochastic theory of molecular collisions. II. Application to atom--vibrotor collisions

    Augustin, S.D.; Rabitz, H.

    1977-01-01

    In this work stochastic theory is applied to the treatment of atom--vibrotor collisions. This is an extension of a previous paper which described molecular collisions by a Pauli master equation or a Fokker--Planck equation. In this framework an energy conserving classical path model is explored, and methods for solving the equations numerically are discussed. The coefficients of the Fokker--Planck equation are shown to be expressible as simple functions of the interaction potential. Estimates of the computational labor are also discussed. Finally as a followup on the initial work, numerical solutions of the master equation for the collinear vibrational excitation problem of Secrest and Johnson are presented in an Appendix

  8. On the algebraic theory of kink sectors: Application to quantum field theory models and collision theory

    Schlingemann, D.

    1996-10-01

    Several two dimensional quantum field theory models have more than one vacuum state. An investigation of super selection sectors in two dimensions from an axiomatic point of view suggests that there should be also states, called soliton or kink states, which interpolate different vacua. Familiar quantum field theory models, for which the existence of kink states have been proven, are the Sine-Gordon and the φ 4 2 -model. In order to establish the existence of kink states for a larger class of models, we investigate the following question: Which are sufficient conditions a pair of vacuum states has to fulfill, such that an interpolating kink state can be constructed? We discuss the problem in the framework of algebraic quantum field theory which includes, for example, the P(φ) 2 -models. We identify a large class of vacuum states, including the vacua of the P(φ) 2 -models, the Yukawa 2 -like models and special types of Wess-Zumino models, for which there is a natural way to construct an interpolating kink state. In two space-time dimensions, massive particle states are kink states. We apply the Haag-Ruelle collision theory to kink sectors in order to analyze the asymptotic scattering states. We show that for special configurations of n kinks the scattering states describe n freely moving non interacting particles. (orig.)

  9. Review and Application of Ship Collision and Grounding Analysis Procedures

    Pedersen, Preben Terndrup

    2010-01-01

    It is the purpose of the paper to present a review of prediction and analysis tools for collision and grounding analyses and to outline a probabilistic procedure for which these tools can be used by the maritime industry to develop performance based rules to reduce the risk associated with human,......, environmental and economic costs of collision and grounding events. The main goal of collision and grounding research should be to identify the most economic risk control options associated with prevention and mitigation of collision and grounding events....

  10. Semiclassical theory of resonance inelastic electron-molecule collisions

    Kazanskij, A.K.

    1986-01-01

    Semiclassical approach to the theory of resonance electron-molecule collisions, unlocal with respect to interatomic distance was developed. Two problems were considered: modified adiabatic approach for sigle-pole approximation of R-matrix and Fano-Feshbach-Bardsley theory. It is shown that these problems are similar in semiclassical approximation. A simple equation system with coefficients expressed in quadratures was obtained. It enables to determine amplitudes of all processes (including dissociation adhesion, association ejection, free-free and free-bound transitions) in energetic representation with respect to nucleus vibrations in molecule with allowance for both descrete and continuous spectra of nucleus motion in molecule. Quantitative investigation of the system results to the notion of dynamic energy curve of intermediate state, generalizing the motion of such curve in boomerang theory

  11. Nuclear collision theory with many-body correlations, 2

    Kurihara, Yukio.

    1984-12-01

    A nuclear collision theory, in which the many-body correlation induced by the strong short-ranged repulsion and medium-ranged attraction of the realistic NN interaction is explicitly included, is applied to the deuteron+deuteron elastic scattering at low energies. Pair correlation functions calculated by the present theory are very different from the Hackenbroich et al. 's one. They contain not only the short-ranged suppressive correlation, but also the medium-ranged enhancing correlation. The former changes the shape of the d-d potential from the wine-bottle one. And the latter makes the d-d potential much more attractive. This effect is necessary for reproducing a bump around thatesub(cm)=90 0 in the experimental elastic differential cross section. The phase shifts evaluated by the present theory are compared with those from the resonating-group method. (author)

  12. Effects of collisions on conservation laws in gyrokinetic field theory

    Sugama, H.; Nunami, M. [National Institute for Fusion Science, Toki 509-5292 (Japan); Department of Fusion Science, SOKENDAI (The Graduate University for Advanced Studies), Toki 509-5292 (Japan); Watanabe, T.-H. [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

    2015-08-15

    Effects of collisions on conservation laws for toroidal plasmas are investigated based on the gyrokinetic field theory. Associating the collisional system with a corresponding collisionless system at a given time such that the two systems have the same distribution functions and electromagnetic fields instantaneously, it is shown how the collisionless conservation laws derived from Noether's theorem are modified by the collision term. Effects of the external source term added into the gyrokinetic equation can be formulated similarly with the collisional effects. Particle, energy, and toroidal momentum balance equations including collisional and turbulent transport fluxes are systematically derived using a novel gyrokinetic collision operator, by which the collisional change rates of energy and canonical toroidal angular momentum per unit volume in the gyrocenter space can be given in the conservative forms. The ensemble-averaged transport equations of particles, energy, and toroidal momentum given in the present work are shown to include classical, neoclassical, and turbulent transport fluxes which agree with those derived from conventional recursive formulations.

  13. Simple and Multi-collision of an Ellipsoid with Planar Surfaces. Part I: Theory

    Nicolae–Doru Stănescu

    2017-11-01

    Full Text Available This paper discusses the problem of simultaneous collisions between an ellipsoid and some planar surfaces. The approach is one based on the theory of screws and uses the notion of inertance. The authors consider that the coefficients of restitution are different for each planar surface and they obtain the velocities after the collision. An example concludes the theory.

  14. Putting Reaction Rates and Collision Theory in the Hands of Your Students.

    Evenson, Andy

    2002-01-01

    Describes a simulation that can be used to give concrete analogies of collision theory and the factors that affect reaction rates including temperature, concentration, catalyst, and molecular orientation. The simulation works best if done as an introduction to the concepts to help prevent misconceptions about reaction rates and collision theory.…

  15. A few methods for the theory of collective motions and collisions

    Giraud, B.G.

    1984-01-01

    In this series of lectures the time-dependent Hartree-Fock theory of nuclear motions and collisions are treated for collective motion only. For the theory of collisions a representation, the boosted shell model, is proposed in which matrix elements of the T-matrix are easier to evaluate via a variational principle

  16. Perturbation theory and collision probability formalism. Vol. 2

    Nasr, M [National Center for Nuclear Safety and Radiation Control, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    Perturbation theory is commonly used in evaluating the activity effects, particularly those resulting from small and localized perturbation in multiplying media., e.g. in small sample reactivity measurements. The Boltzmann integral transport equation is generally used for evaluating the direct and adjoint fluxes in the heterogenous lattice cells to be used in the perturbation equations. When applying perturbation theory in this formalism, a term involving the perturbation effects on the special transfer kernel arises. This term is difficult to evaluate correctly, since it involves an integration all over the entire system. The main advantage of the perturbation theory which is the limitation of the integration procedure on the perturbation region is found to be of no practical use in such cases. In the present work, the perturbation equation in the collision probability formalism is analyzed. A mathematical treatment of the term in question is performed. A new mathematical expression for this term is derived. The new expression which can be estimated easily is derived.

  17. Nucleus–nucleus collisions at RHIC: A review

    strong enough to achieve local thermodynamic equilibrium. If they are, it .... collisions, and a third parameter (the strangeness suppression factor) must be in- troduced to ... The success of statistical models is in fact a puzzle for theorists, because .... theories using the AdS/CFT correspondence, and it turns out to be extremely.

  18. Theory of heavy ion collision physics in hadron therapy

    2013-01-01

    Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features detailed reviews written by leading international researchers. This volume focuses on the theory of heavy ion physics in medicine.

  19. Review of chiral perturbation theory

    Abstract. A review of chiral perturbation theory and recent developments on the comparison of its predictions with experiment is presented. Some interesting topics with scope for further elaboration are touched upon.

  20. Chameleonic Theories: A Short Review

    Andrea Zanzi

    2015-12-01

    Full Text Available In the chameleon mechanism, a field (typically scalar has a mass that depends on the matter density of the environment: the larger is the matter density, the larger is the mass of the chameleon. We briefly review some aspects of chameleonic theories. In particular, in a typical class of these theories, we discuss the lagrangian, the role of conformal transformations, the equation of motion and the thin-shell effect. We also discuss f ( R theories and chameleonic quantum gravity.

  1. Effects of Self-Similar Collisions in the Theory of Pressure Broadening and Shift

    Kharintsev, S.S.; Salakhov, M.Kh.

    1999-01-01

    In the present paper the self-similar collision model is developed in terms of fractal Brownian motion. Within this model framework, collisions are assumed to carry a non-Markovian character and, therefore, possible memory collisional effects are not taken into account. Applying a self-similar collision model for the motion of the radiator and Anderson-Talman phase-shift theory of collisional broadening, a general formula for the correlation function in the impact limit is described. (author)

  2. Generalizability Theory [Book Review].

    Kane, Michael

    2003-01-01

    This book presents a comprehensive overview of univariate and multivariate generalizability theory, a psychometric model that provides a powerful approach to the analysis of errors of measurement through the use of random-effects and mixed-model analysis of variance. (SLD)

  3. Relaxation phenomena in and microscopic transport theories of deeply inelastic collisions between heavy ions

    Noerenberg, W.

    1976-01-01

    Relaxation phenomena in deeply inelastic collisions are qualitatively discussed and compared with precompound reactions. Different approaches for describing these processes are reviewed, in particular the microscopic transport theories, which can be understood from a generalized master equation for macroscopic variables. The Markoff approximation and the classical limit for the relative motion lead to two coupled equations, the classical equation of relative motion with friction and a Pauli master equation for the internal degrees of freedom. The master equation approximated by the corresponding Fokker-Planck equation for mass transfer and energy dissipation is discussed in detail. Simple analytic expressions are derived for the transport coefficients as functions of excitation energy, total mass, mass fragmentation and relative angular momentum. Calculated transport coefficients are compared with experimental values. Problems and future developments in microscopic transport theories are outlined. (orig.) [de

  4. Hadronic collision and hadronic structure (an experimental review)

    Davier, M.

    1975-01-01

    In this set of lectures an attempt is made to present a survey of the available experimental data on hadronic collisions at large transverse momentum, together with their current phenomenological descriptions. In particular, the experimental confirmation of constituent structure is looked at in a critical way. The emphasis throughout is to let the data speak in the most unbiased way and to gather evidence as to the short range structure of the hadronic interactions. Finally the current information on lepton production in hadronic collisions is reviewed

  5. Towards relativistic heavy ion collisions by small steps towards the stars. [Review

    Scott, D.K.

    1979-03-01

    A review lecture is given on current attempts to search for the exotic processes occurring in relativistic heavy ion collisions. From peripheral collisions the discussion proceeds to central collisions and lastly the search for the exotic, in which the tools developed for the study of peripheral and central collisions are used. 200 references. (JFP)

  6. A literature review of risk assessment of ship-FPSO collisions

    Wang, Ge; Pedersen, Preben Terndrup

    2007-01-01

    This paper reviews the state of the art of the research and analysis on the risks of collision with offshore installations. The focus is placed on: existing criteria, FPSO collision accident, design scenarios for FPSO collision, mechanics of collision incidents, and consequences. The content...

  7. Semiclassical approximations in a mean-field theory with collision terms

    Galetti, D.

    1986-01-01

    Semiclassical approximations in a mean-field theory with collision terms are discussed taking the time dependent Hartree-Fock method as framework in the obtainment of the relevant parameters.(L.C.) [pt

  8. On the extension of (e,2e) theory to coincidence studies of ion-atom collisions

    Godunov, A.L.; Kampp, Marco; Sulik, B.; Walters, H.R.J.; Whelan, Colm T.

    2007-01-01

    The extension of (e,2e) theory to the coincidence studies of ion-atom collisions is considered. The simultaneous ionization of projectile and target is discussed and results are presented for transfer ionization

  9. R-Matrix Theory of Atomic Collisions Application to Atomic, Molecular and Optical Processes

    Burke, Philip George

    2011-01-01

    Commencing with a self-contained overview of atomic collision theory, this monograph presents recent developments of R-matrix theory and its applications to a wide-range of atomic molecular and optical processes. These developments include electron and photon collisions with atoms, ions and molecules required in the analysis of laboratory and astrophysical plasmas, multiphoton processes required in the analysis of superintense laser interactions with atoms and molecules and positron collisions with atoms and molecules required in antimatter studies of scientific and technologial importance. Basic mathematical results and general and widely used R-matrix computer programs are summarized in the appendices.

  10. Theory of collective dynamics: flow, fluctuations and correlations in heavy ion collisions

    Denicol, Gabriel S. [Physics Department, Brookhaven National Lab, Building 510A, Upton, NY, 11973 (United States); Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A 2T8 (Canada)

    2016-12-15

    I review recent developments in the hydrodynamic modeling of ultra-relativistic heavy ion collisions and the extraction of the properties of bulk QCD matter from heavy ion collision measurements. I briefly summarize the current framework used for the theoretical modeling of heavy ion collisions and report the recent progress on the extraction of the temperature dependence of the shear and bulk viscosity coefficients, the development of statistical tools for data-to-model comparison, and anisotropic hydrodynamics. All these recent developments in our field pave the way for more quantitative determination of the transport properties of bulk QCD matter from the experimental heavy ion collision program.

  11. Experimental review of soft and semihard collisions

    Van Hal, P.A.

    1987-01-01

    Three topics are discussed in this review: I. Multiplicities: With the emphasis on the negative binomial (NB) fits to multiplicity distributions in limited (pseudo) rapidity intervals. A short comment about the C-moments in limited (pseudo) rapidity intervals is added. II. Multiplicity dependence of the average transverse momentum . III. The rise of vs x/sub F/ with increasing energy (seagull effect). In all three topics multiplicities play an important role. The number of experiments from which data will be shown in this review is limited. On all three topics new data from the NA22 collaboration is shown

  12. Microscopic description of low-energy nuclear collisions: review and perspective

    Bonche, Paul

    2000-01-01

    The primary goal of this lecture is a review of the microscopic approaches to nuclear reactions. Semi-phenomenological theories will not be discussed. First the Time-Dependent Hartree-Fock formalism is recalled. The effective nucleon-nucleon interactions used in TDHF calculations are discussed. Applications to collisions are presented in different approximation scheme, one-dimensional dynamics, approximate three-dimensional ones.... Finally two microscopic extensions beyond mean-field are reviewed: the variational principal of Balian and Veneroni and the implementation of residual two-body interactions in the Time-Dependent Density Matrix (TDDM) and the Extended Time-Dependent Hartree-Fock schemes (ET-DHF). (author)

  13. Review of quantum collision dynamics in Debye plasmas

    R.K. Janev

    2016-09-01

    Full Text Available Hot, dense plasmas exhibit screened Coulomb interactions, resulting from the collective effects of correlated many-particle interactions. In the lowest particle correlation order (pair-wise correlations, the interaction between charged plasma particles reduces to the Debye–Hückel (Yukawa-type potential, characterized by the Debye screening length. Due to the importance of Coulomb interaction screening in dense laboratory and astrophysical plasmas, hundreds of theoretical investigations have been carried out in the past few decades on the plasma screening effects on the electronic structure of atoms and their collision processes employing the Debye–Hückel screening model. The present article aims at providing a comprehensive review of the recent studies in atomic physics in Debye plasmas. Specifically, the work on atomic electronic structure, photon excitation and ionization, electron/positron impact excitation and ionization, and excitation, ionization and charge transfer of ion-atom/ion collisions will be reviewed.

  14. Quantum mechanical theory of positron production in heavy ion collisions with nuclear contact

    Heinz, U.

    1986-01-01

    The interplay between atomic and nuclear interactions in heavy ion collisions with nuclear contact is studied. The general theoretical description is outlined and analyzed in a number of different limits (semiclassical approximation, DWBA, fully quantal description). The two most important physical mechanisms for generating atomic-nuclear interference, i.e., energy conservation and the introduction of additional phase shifts by nuclear reactions, are extracted. The resulting typical coupling matrix elements are analyzed for their relative importance in atomic and nuclear excitations. The description of nuclear influence on atomic excitations in terms of a classical time delay caused by nuclear reactions is reviewed, and its relationship to the underlying quantal character of the nuclear reaction is discussed. The theory is applied to spontaneous positron emission in supercritical heavy-ion collisions (Z/sub tot/ ≥ 173). It is shown that nuclear contact can lead to line structures in the positron energy spectra if the probability distribution for nuclear delay times caused by the contact has contributions for T ≥ 10 -19 sec. We explicitly evaluate a model where a pocket in the internuclear potential near the touching configuration leads to formation of nuclear molecules, and predict a resonance-like excitation function for the positron peak. 25 refs., 7 figs

  15. Multifractional theories: an unconventional review

    Calcagni, Gianluca [Instituto de Estructura de la Materia, CSIC,Serrano 121, 28006 Madrid (Spain)

    2017-03-27

    We answer to 72 frequently asked questions about theories of multifractional spacetimes. Apart from reviewing and reorganizing what we already know about such theories, we discuss the physical meaning and consequences of the very recent flow-equation theorem on dimensional flow in quantum gravity, in particular its enormous impact on the multifractional paradigm. We will also get new theoretical results about the construction of multifractional derivatives and the symmetries in the yet-unexplored theory T{sub γ}, the resolution of ambiguities in the calculation of the spectral dimension, the relation between the theory T{sub q} with q-derivatives and the theory T{sub γ} with fractional derivatives, the interpretation of complex dimensions in quantum gravity, the frame choice at the quantum level, the physical interpretation of the propagator in T{sub γ} as an infinite superposition of quasiparticle modes, the relation between multifractional theories and quantum gravity, and the issue of renormalization, arguing that power-counting arguments do not capture the exotic properties of extreme UV regimes of multifractional geometry, where T{sub γ} may indeed be renormalizable. A careful discussion of experimental bounds and new constraints are also presented.

  16. Transport theory of deep-inelastic collisions between heavy nuclei

    Ayik, S.; Noerenberg, W.; Schuermann, B.

    1975-01-01

    In collisions between heavy nuclei, the major part of the total cross-section is due to deep-inelastic processes. These processes have been studied within a quantum-statistical approach leading to transport equations of the Fokker-Planck type (generalized diffusion equation). Transport coefficients have been studied within a model. (orig./WL) [de

  17. Effects of turbulence on the geometric collision rate of sedimenting droplets. Part 2. Theory and parameterization

    Ayala, Orlando; Rosa, Bogdan; Wang Lianping

    2008-01-01

    The effect of air turbulence on the geometric collision kernel of cloud droplets can be predicted if the effects of air turbulence on two kinematic pair statistics can be modeled. The first is the average radial relative velocity and the second is the radial distribution function (RDF). A survey of the literature shows that no theory is available for predicting the radial relative velocity of finite-inertia sedimenting droplets in a turbulent flow. In this paper, a theory for the radial relative velocity is developed, using a statistical approach assuming that gravitational sedimentation dominates the relative motion of droplets before collision. In the weak-inertia limit, the theory reveals a new term making a positive contribution to the radial relative velocity resulting from a coupling between sedimentation and air turbulence on the motion of finite-inertia droplets. The theory is compared to the direct numerical simulations (DNS) results in part 1, showing a reasonable agreement with the DNS data for bidisperse cloud droplets. For droplets larger than 30 μm in radius, a nonlinear drag (NLD) can also be included in the theory in terms of an effective inertial response time and an effective terminal velocity. In addition, an empirical model is developed to quantify the RDF. This, together with the theory for radial relative velocity, provides a parameterization for the turbulent geometric collision kernel. Using this integrated model, we find that turbulence could triple the geometric collision kernel, relative to the stagnant air case, for a droplet pair of 10 and 20 μm sedimenting through a cumulus cloud at R λ =2x10 4 and ε=600 cm 2 s -3 . For the self-collisions of 20 μm droplets, the collision kernel depends sensitively on the flow dissipation rate

  18. Contribution to the neutronic theory of random stacks (diffusion coefficient and first-flight collision probabilities) with a general theorem on collision probabilities

    Dixmier, Marc.

    1980-10-01

    A general expression of the diffusion coefficient (d.c.) of neutrons was given, with stress being put on symmetries. A system of first-flight collision probabilities for the case of a random stack of any number of types of one- and two-zoned spherical pebbles, with an albedo at the frontiers of the elements or (either) consideration of the interstital medium, was built; to that end, the bases of collision probability theory were reviewed, and a wide generalisation of the reciprocity theorem for those probabilities was demonstrated. The migration area of neutrons was expressed for any random stack of convex, 'simple' and 'regular-contact' elements, taking into account the correlations between free-paths; the average cosinus of re-emission of neutrons by an element, in the case of a homogeneous spherical pebble and the transport approximation, was expressed; the superiority of the so-found result over Behrens' theory, for the type of media under consideration, was established. The 'fine structure current term' of the d.c. was also expressed, and it was shown that its 'polarisation term' is negligible. Numerical applications showed that the global heterogeneity effect on the d.c. of pebble-bed reactors is comparable with that for Graphite-moderated, Carbon gas-cooled, natural Uranium reactors. The code CARACOLE, which integrates all the results here obtained, was introduced [fr

  19. Relativistic hydrodynamic theory of heavy-ion collisions

    Amsden, A.A.; Bertsch, G.F.; Harlow, F.H.; Nix, J.R.

    1975-01-01

    By use of finite-difference methods the classical relativistic equations of motion for the head-on collision of two heavy nuclei are solved. For 16 O projectiles incident onto various targets at laboratory bombarding energies per nucleon less than or equal to2.1 GeV, curved shock waves develop. The target and projectile are deformed and compressed into crescents of revolution. This is followed by rarefaction waves and an overall expansion of the matter into a moderately wide distribution of angles

  20. A group-kinetic theory of turbulent collective collisions

    Tchen, C.M.; Misguich, J.H.

    1983-05-01

    The main objective is the derivation of the kinetic equation of turbulence which has a memory in the turbulent collision integral. We consider the basic pair-interaction, and the interaction between a fluctuation and the organized cluster of other fluctuations in the collection systems, called the multiple interaction. By a group-scaling procedure, a fluctuation is decomposed into three groups to represent the three coupled transport processes of evolution, transport coefficient, and relaxation. The kinetic equation of the scaled singlet distribution is capable of investigating the spectrum of turbulence without the need of the knowledge of the pair distribution. The exact propagator describes the detailed trajectory in the phase space, and is fundamental to the Lagrangian-Eulerian transformation. We calculate the propagator and its scaled groups by means of a probability of retrograde transition. Thus our derivation of the kinetic equation of the distribution involves a parallel development of the kinetic equations of the propagator and the transition probability. In this way, we can avoid the assumptions of independence and normality. Our result shows that the multiple interaction contributes to a shielding and an enchancement of the collision in weak turbulence and strong turbulence, respectively. The weak turbulence is dominated by the wave resonance, and the strong turbulence is dominated by the diffusion

  1. Medical radiation dosimetry theory of charged particle collision energy loss

    McParland, Brian J

    2014-01-01

    Accurate radiation dosimetry is a requirement of radiation oncology, diagnostic radiology and nuclear medicine. It is necessary so as to satisfy the needs of patient safety, therapeutic and diagnostic optimisation, and retrospective epidemiological studies of the biological effects resulting from low absorbed doses of ionising radiation. The radiation absorbed dose received by the patient is the ultimate consequence of the transfer of kinetic energy through collisions between energetic charged particles and atoms of the tissue being traversed. Thus, the ability of the medical physicist to both measure and calculate accurately patient dosimetry demands a deep understanding of the physics of charged particle interactions with matter. Interestingly, the physics of charged particle energy loss has an almost exclusively theoretical basis, thus necessitating an advanced theoretical understanding of the subject in order to apply it appropriately to the clinical regime. ​ Each year, about one-third of the worl...

  2. On the Collision Nature of Two Coronal Mass Ejections: A Review

    Shen, Fang; Wang, Yuming; Shen, Chenglong; Feng, Xueshang

    2017-08-01

    Observational and numerical studies have shown that the kinematic characteristics of two or more coronal mass ejections (CMEs) may change significantly after a CME collision. The collision of CMEs can have a different nature, i.e. inelastic, elastic, and superelastic processes, depending on their initial kinematic characteristics. In this article, we first review the existing definitions of collision types including Newton's classical definition, the energy definition, Poisson's definition, and Stronge's definition, of which the first two were used in the studies of CME-CME collisions. Then, we review the recent research progresses on the nature of CME-CME collisions with the focus on which CME kinematic properties affect the collision nature. It is shown that observational analysis and numerical simulations can both yield an inelastic, perfectly inelastic, merging-like collision, or a high possibility of a superelastic collision. Meanwhile, previous studies based on a 3D collision picture suggested that a low approaching speed of two CMEs is favorable for a superelastic nature. Since CMEs are an expanding magnetized plasma structure, the CME collision process is quite complex, and we discuss this complexity. Moreover, the models used in both observational and numerical studies contain many limitations. All of the previous studies on collisions have not shown the separation of two colliding CMEs after a collision. Therefore the collision between CMEs cannot be considered as an ideal process in the context of a classical Newtonian definition. In addition, many factors are not considered in either observational analysis or numerical studies, e.g. CME-driven shocks and magnetic reconnections. Owing to the complexity of the CME collision process, a more detailed and in-depth observational analysis and simulation work are needed to fully understand the CME collision process.

  3. On the local theory of resonant inelastic collisions of slow electrons with carbon dioxide

    Kazansky, A.K.; Sergeeva, L.Yu.

    1994-01-01

    A method of calculating the cross sections of inelastic vibronic transitions in collisions of slow electrons with polyatomic molecules in the framework of the local theory (the 'boomerang' model) is proposed. The method is based on the study of the time evolution of the initial vibronic wavefunction; the evolution is governed by the (complex valued) Hamiltonian of the intermediate anion state. The method has been applied to the consideration of inelastic electron collisions with the CO 2 molecule in the two-mode approximation (symmetrical stretching and bending). The results obtained demonstrate the importance of the two-mode description for the system which can undergo the Renner transition. (Author)

  4. The Theory of High Energy Collision Processes - Final Report DOE/ER/40158-1

    Wu, Tai, T.

    2011-09-15

    In 1984, DOE awarded Harvard University a new Grant DE-FG02-84ER40158 to continue their support of Tai Tsun Wu as Principal Investigator of research on the theory of high energy collision processes. This Grant was renewed and remained active continuously from June 1, 1984 through November 30, 2007. Topics of interest during the 23-year duration of this Grant include: the theory and phenomenology of collision and production processes at ever higher energies; helicity methods of QED and QCD; neutrino oscillations and masses; Yang-Mills gauge theory; Beamstrahlung; Fermi pseudopotentials; magnetic monopoles and dyons; cosmology; classical confinement; mass relations; Bose-Einstein condensation; and large-momentum-transfer scattering processes. This Final Report describes the research carried out on Grant DE-FG02-84ER40158 for the period June 1, 1984 through November 30, 2007. Two books resulted from this project and a total of 125 publications.

  5. Density functional theory: Foundations reviewed

    Kryachko, Eugene S., E-mail: eugene.kryachko@ulg.ac.be [Bogolyubov Institute for Theoretical Physics, Kiev, 03680 (Ukraine); Ludeña, Eduardo V., E-mail: popluabe@yahoo.es [Centro de Química, Instituto Venezolano de Investigaciones Científicas, IVIC, Apartado 21827, Caracas 1020-A (Venezuela, Bolivarian Republic of); Prometheus Program, Senescyt (Ecuador); Grupo Ecuatoriano para el Estudio Experimental y Teórico de Nanosistemas, GETNano, USFQ, N104-E, Quito (Ecuador); Escuela Politécnica Superior del Litoral, ESPOL, Guayaquil (Ecuador)

    2014-11-10

    Guided by the above motto (quotation), we review a broad range of issues lying at the foundations of Density Functional Theory, DFT, a theory which is currently omnipresent in our everyday computational study of atoms and molecules, solids and nano-materials, and which lies at the heart of modern many-body computational technologies. The key goal is to demonstrate that there are definitely the ways to improve DFT. We start by considering DFT in the larger context provided by reduced density matrix theory (RDMT) and natural orbital functional theory (NOFT), and examine the implications that N-representability conditions on the second-order reduced density matrix (2-RDM) have not only on RDMT and NOFT but, also, by extension, on the functionals of DFT. This examination is timely in view of the fact that necessary and sufficient N-representability conditions on the 2-RDM have recently been attained. In the second place, we review some problems appearing in the original formulation of the first Hohenberg–Kohn theorem which is still a subject of some controversy. In this vein we recall Lieb’s comment on this proof and the extension to this proof given by Pino et al. (2009), and in this context examine the conditions that must be met in order that the one-to-one correspondence between ground-state densities and external potentials remains valid for finite subspaces (namely, the subspaces where all Kohn–Sham solutions are obtained in practical applications). We also consider the issue of whether the Kohn–Sham equations can be derived from basic principles or whether they are postulated. We examine this problem in relation to ab initio DFT. The possibility of postulating arbitrary Kohn–Sham-type equations, where the effective potential is by definition some arbitrary mixture of local and non-local terms, is discussed. We also deal with the issue of whether there exists a universal functional, or whether one should advocate instead the construction of problem

  6. Transverse Energy in nucleus-nucleus collisions: A review

    Tincknell, M.

    1988-01-01

    The status of Transverse Energy (E/sub T/) in relativistic nucleus-nucleus collisions at the Brookhaven AGS and the CERN SPS is reviewed. The definition of E/sub T/ and its physical significance are discussed. The basic techniques and limitations of the experimental measurements are presented. The acceptances of the major experiments to be discussed are shown, along with remarks about their idiosyncrasies. The data demonstrate that the nuclear geometry of colliding spheres primarily determines the shapes of the observed spectra. Careful account of the acceptances is crucial to comparing and interpreting results. It is concluded that nuclear stopping power is high, and that the amount of energy deposited into the interaction volume is increasing with beam energy even at SPS energies. The energy densities believed to be obtained at the SPS are close to the critical values predicted for the onset of a quark-gluon plasma. 25 refs., 8 figs

  7. Removal of nonorthogonality in the Born theory used for study of electron capture in high energy ion-atom collisions

    Kimura, M.

    1989-01-01

    We show the complete removal of the nonorthogonality of wave functions between initial and final states in the Born theory. Hence, this treatment offers more realistic electron capture cross sections in high energy ion-atom collisions. Representative results for resonant electron capture in H + + H collision are discussed in conjunction with other perturbative results. 10 refs., 1 fig

  8. Review of economic theories of regulation

    den Hertog, J.A.|info:eu-repo/dai/nl/21319161X

    2010-01-01

    This paper reviews the economic theories of regulation. It discusses the public and private interest theories of regulation, as the criticisms that have been leveled at them. The extent to which these theories are also able to account for privatization and deregulation is evaluated and policies

  9. Progress in the application of classical S-matrix theory to inelastic collision processes

    McCurdy, C.W.; Miller, W.H.

    1980-01-01

    Methods are described which effectively solve two of the technical difficulties associated with applying classical S-matrix theory to inelastic/reactive scattering. Specifically, it is shown that rather standard numerical methods can be used to solve the ''root search'' problem (i.e., the nonlinear boundary value problem necessary to impose semiclassical quantum conditions at the beginning and the end of the classical trajectories) and also how complex classical trajectories, which are necessary to describe classically forbidden (i.e., tunneling) processes, can be computed in a numerically stable way. Application is made to vibrational relaxation of H 2 by collision with He (within the helicity conserving approximation). The only remaining problem with regard to applying classical S-matrix theory to complex collision processes has to do with the availability of multidimensional uniform asymptotic formulas for interpolating the ''primitive'' semiclassical expressions between their various regions of validity

  10. Random matrix theory and analysis of nucleus-nucleus collision at high energies

    Shahaliev, E.I.; Inst. of Radiation Problems, Baku; ); Kuznetsov, A.A.; Suleymanov, M.K.; ); Teryaev, O.V.; )

    2006-01-01

    A novel method for analysis of experimental data obtained at relativistic nucleus-nucleus collisions is proposed. The method, based on the ideas of Random Matrix Theory, is applied to detect systematic errors that occur at measurements of momentum distributions of emitted particles. The unfolded momentum distribution is well described by the Gaussian orthogonal ensemble of random matrices, when the uncertainty in the momentum distribution is maximal. The method is free from unwanted background contributions [ru

  11. Simple kinetic theory model of reactive collisions. IV. Laboratory fixed orientational cross sections

    Evans, G.T.

    1987-01-01

    The differential orientational cross section, obtainable from molecular beam experiments on aligned molecules, is calculated using the line-of-normals model for reactive collisions involving hard convex bodies. By means of kinetic theory methods, the dependence of the cross section on the angle of attack γ 0 is expressed in a Legendre function expansion. Each of the Legendre expansion coefficients is given by an integral over the molecule-fixed cross section and functions of the orientation dependent threshold energy

  12. Fully-converged three-dimensional collision-induced dissociation calculations with Faddeev-AGS theory

    Haftel, M.I.; Lim, T.K.

    1981-09-01

    The first fully-converged quantum-mechanical calculation of the collision-induced dissociation cross section in a three-dimensional-model system of three helium-like atoms is reported. Faddeev-AGS theory is used. It yields as a bonus the elastic atom-diatom cross section. The obtained results resemble those from some collinear models but indicate clearly the futility of multiple-scattering approximations except at hyperthermal energies. (orig.)

  13. Discussion of electron capture theories for ion-atom collisions at high energies

    Miraglia, J E [Instituto de Astronomia y Fisica del Espacio, Buenos Aires (Argentina); Piacentini, R D [Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Rivarola, R D [Rosario Univ. Nacional (Argentina). Dept. de Fisica; Salin, A [Bordeaux-1 Univ., 33 - Talence (France)

    1981-03-14

    Different theories of charge exchange processes in ion-atom collisions at high energies for the H/sup +/-H system are considered. Large discrepancies are found in the differential cross sections obtained from the various models. The validity of Dettmann's peaking approximation is analysed by comparison with exact values for the first- and second-order Oppenheimer-Brinkman-Kramers (OBK 1 and OBK 2) theories. It is also shown that for energies up to a few MeV the OBK 2 differential cross sections are higher than the corresponding OBK 1 ones. Total cross sections in the OBK 2 approximation are given.

  14. Strangeness production in nucleus-nucleus collisions: An experimental review

    Odyniec, G.

    1990-12-01

    In experiments with oxygen (60 and 200 GeV/N) and sulphur (200 GeV/N) ions at CERNSPS, large energy densities of the order of 2--3 GeV/fm 3 have been observed, which according to QCD calculations, satisfy necessary conditions for the formation of a quark gluon plasma (QGP) phase. Under such conditions, colour would no longer be confined to hadronic dimensions, and quarks and gluons will propagate freely throughout an extended volume. Somehow lower energy densities, of the order of 0.7--1 GeV/fm 3 , were observed in AGS experiments with 15 GeV/N silicon beams and heavy targets. These energy densities might be adequate for investigations of the pre-equilibrium stage, during which the momentum space distribution has been degradated from its initial value but is not yet thermal. First experimental results, available now, show promise of seeing signs of a new phase of matter. In this review the current status of the selective experimental results on strange-particle production, which are relevant to equilibration and QGP formation in nucleus-nucleus collisions, is presented

  15. Time-dependent shell-model theory of dissipative heavy-ion collisions

    Ayik, S.; Noerenberg, W.

    1982-01-01

    A transport theory is formulated within a time-dependent shell-model approach. Time averaging of the equations for macroscopic quantities lead to irreversibility and justifies weak-coupling limit and Markov approximation for the (energy-conserving) one- and two-body collision terms. Two coupled equations for the occupation probabilities of dynamical single-particle states and for the collective variable are derived and explicit formulas for transition rates, dynamical forces, mass parameters and friction coefficients are given. The applicability of the formulation in terms of characteristic quantities of nuclear systems is considered in detail and some peculiarities due to memory effects in the initial equilibration process of heavy-ion collisions are discussed. (orig.)

  16. Theory of the l-state population of Rydberg states formed in ion-solid collisions

    Kemmler, J.; Burgdoerfer, J.; Reinhold, C.O.

    1991-01-01

    The experimentally observed high-l-state population of ions excited in ion-solid interactions differs sharply from l-state populations produced in ion-atom collisions. We have studied the population dynamics of electronic excitation and transport within the framework of a classical transport theory for O 2+ (2-MeV/u) ions traversing C foils. The resulting delayed-photon-emission intensities are found to be in very good agreement with experiment. Initial phase-space conditions have been obtained from both classical-trajectory Monte Carlo calculations and random initial distributions. We find evidence that the very-high-l-state populations produced in ion-solid collisions are the result of a diffusion to high-l states under the influence of multiple scattering in the bulk of the solid

  17. Laser-assisted collisions: The Kroll-Watson formula and bremsstrahlung theory

    Geltman, S.

    1996-01-01

    Recent measurements on CO 2 -laser-assisted electron-atom collisions have shown large inconsistencies with the Kroll-Watson formula for small-angle scattering. We have carried out a detailed study to compare the predictions of Kroll-Watson theory (for both single and multimode fields) with those of conventional perturbation theory for stimulated free-free transitions. It is found that for E 0 /2ω 2 <1, where perturbation theory is valid, there are large differences with the Kroll-Watson theory. Comparisons of experimental variations with respect to scattering angle and electron energy show much better agreement with perturbation theory than with Kroll-Watson theory. A study of the angular variations in perturbation theory shows that use of the open-quote open-quote outgoing close-quote close-quote wave final state gives much better agreement with experiment than does the open-quote open-quote ingoing close-quote close-quote wave final state, which is different from the choice made in early bremsstrahlung theory. copyright 1996 The American Physical Society

  18. Positron-atom collisions

    Drachman, R.J.

    1984-01-01

    The past decade has seen the field of positron-atom collisions mature into an important sub-field of atomic physics. Increasingly intense positron sources are leading towards a situation in which electron and positron collision experiments will be on almost an equal footing, challenging theory to analyze their similarities and differences. The author reviews the advances made in theory, including dispersion theory, resonances, and inelastic processes. A survey of experimental progress and a brief discussion of astrophysical positronics is also included. (Auth.)

  19. Transport theory for deeply inelastic heavy-ion collisions within the statistical model

    Shlomo, S.

    1978-01-01

    The theory I am going to describe has been developed recently by Agassi, Ko and Weidenmueller. It is based on a random-matrix model for the form factor (FF) which couples a collective degree of freedom, taken to be the distance anti r between the two ions, with the intrinsic degrees of freedom. This study of dissipative phenomena in a microsystem was triggered by the success of the simple friction and diffusion models in describing experimental data on deeply inelastic collisions. I plan to describe the underlying physical assumptions, to outline the theoretical developments and to show some very recent results. (orig.) [de

  20. Grounded theory research: literature reviewing and reflexivity.

    McGhee, Gerry; Marland, Glenn R; Atkinson, Jacqueline

    2007-11-01

    This paper is a report of a discussion of the arguments surrounding the role of the initial literature review in grounded theory. Researchers new to grounded theory may find themselves confused about the literature review, something we ourselves experienced, pointing to the need for clarity about use of the literature in grounded theory to help guide others about to embark on similar research journeys. The arguments for and against the use of a substantial topic-related initial literature review in a grounded theory study are discussed, giving examples from our own studies. The use of theoretically sampled literature and the necessity for reflexivity are also discussed. Reflexivity is viewed as the explicit quest to limit researcher effects on the data by awareness of self, something seen as integral both to the process of data collection and the constant comparison method essential to grounded theory. A researcher who is close to the field may already be theoretically sensitized and familiar with the literature on the study topic. Use of literature or any other preknowledge should not prevent a grounded theory arising from the inductive-deductive interplay which is at the heart of this method. Reflexivity is needed to prevent prior knowledge distorting the researcher's perceptions of the data.

  1. Atomic-scale simulation of dust grain collisions: Surface chemistry and dissipation beyond existing theory

    Quadery, Abrar H.; Doan, Baochi D.; Tucker, William C.; Dove, Adrienne R.; Schelling, Patrick K.

    2017-10-01

    The early stages of planet formation involve steps where submicron-sized dust particles collide to form aggregates. However, the mechanism through which millimeter-sized particles aggregate to kilometer-sized planetesimals is still not understood. Dust grain collision experiments carried out in the environment of the Earth lead to the prediction of a 'bouncing barrier' at millimeter-sizes. Theoretical models, e.g., Johnson-Kendall-Roberts and Derjaguin-Muller-Toporov theories, lack two key features, namely the chemistry of dust grain surfaces, and a mechanism for atomic-scale dissipation of energy. Moreover, interaction strengths in these models are parameterized based on experiments done in the Earth's environment. To address these issues, we performed atomic-scale simulations of collisions between nonhydroxylated and hydroxylated amorphous silica nanoparticles. We used the ReaxFF approach which enables modeling chemical reactions using an empirical potential. We found that nonhydroxylated nanograins tend to adhere with much higher probability than suggested by existing theories. By contrast, hydroxylated nanograins exhibit a strong tendency to bounce. Also, the interaction between dust grains has the characteristics of a strong chemical force instead of weak van der Waals forces. This suggests that the formation of strong chemical bonds and dissipation via internal atomic vibration may result in aggregation beyond what is expected based on our current understanding. Our results also indicate that experiments should more carefully consider surface conditions to mimic the space environment. We also report results of simulations with molten silica nanoparticles. It is found that molten particles are more likely to adhere due to viscous dissipation, which supports theories that suggest aggregation to kilometer scales might require grains to be in a molten state.

  2. Quasiclassical R-matrix theory of inelastic processes in collisions of electrons with HCl molecules

    Fabrikant, I.I.

    1991-01-01

    The R-matrix theory for the vibrational excitation and dissociative attachment in e-HCl collisions is developed. Only one pole in the R-matrix expansion is included. This allows for making a connection between the R-matrix and the nonlocal-complex-potential theories, and for obtaining the expression for the dissociative-attachment cross section without using the R-matrix radius in the internuclear coordinate. All matrix elements in the equation for the vibrational-excitation and dissociative-attachment amplitudes are calculated using the quasiclassical approach. We study how the results depend on the number of vibrational levels of the neutral molecule included in the theory and show how to exclude the vibrational continuum by a modification of the nonlocal-complex potential. The results for the vibrational-excitation cross sections are extremely sensitive to the behavior of the R-matrix potential curve near the point of crossing this curve with the potential curve of the neutral molecule. Particularly in some cases the cross section at the threshold peak exhibits the boomerang oscillations earlier found for HCl by Domcke [in Aspects of Electron-Molecule Scattering and Photoionization, edited by A. Herzenberg (AIP, New Haven, 1989), p. 169]. The dissociative-attachment cross sections are in reasonable agreement with experiment and with other theories

  3. Target continuum distorted-wave theory for collisions of fast protons with atomic hydrogen

    Crothers, D.S.F.; Dunseath, K.M.

    1990-01-01

    By considering the target continuum distorted-wave (TCDW) theory as the high-energy limit of the half-way house variational continuum distorted-wave theory, it is shown not only that there is no intermediate elastic divergence but also that the second-order amplitude based on a purely elastic intermediate state is of order υ -6 and is thus negligible. The residual inelastic TCDW theory is developed to second-order at high velocities. It is used to describe charge exchange during collisions of fast protons with atomic hydrogen. Using an on-shell peaking approximation and considering 1s-1s capture it is shown that the residual purely second-order transition amplitude comprises two terms, one real term of order υ -6 and one purely imaginary term of order υ -7 ln υ. At 5 MeV laboratory energy, it is shown that these are negligible. It is also shown that the υ -5 first-order term gives a differential cross section in very good agreement with an experiment at all angles including forward, interference minimum, Thomas maximum and large angles, particularly having folded our theory over experimental resolution. (author)

  4. Prediction of catastrophe theory for heavy-ion collisions at high energies

    Kuchin, I.A.

    2002-01-01

    Studying the nature of limiting fragmentation of nuclei in high energy heavy-ion collisions has shown that the dynamic system of the nucleus is inclined to enter a nonequilibrium state, schottische and disintegrate on separate nucleons under conditions typical to each collision. There is a question: how the phenomenon of multifragmentation is possible here, i. e. formation of several nucleus with masses on interval from a nucleon up to a material nucleus A in a final state. What is it - debris of a material nucleus or newly created daughter nuclei? The purpose of offered report is discussion of this question. The initial for us statement is taken from the theory of dynamic systems. Chaos is a result of hashing of phase space which is carried out by means of operations of distension and compression. The appropriate transformation are called baker-transformation or Smale's horseshoe. The geometrical picture of chaos is a folded relief of multi-dimensional phase space. The stochastic amplification is understood as growth of folder number and their size. In typical interactions of massive ions, chaos formation conditions are provided automatically due to alternate force influence of Coulomb and Yukawa fields - compression is replaced by distension, and distension - by compression. Extending this representation on a case of massive ion collision, we supplement it accounting a possibility of constituents (nucleons) strong interaction on small distances. The easiest way to make it is approximating minima of potential function V(x, c) in catastrophe theory by rectangular holes of Fermi-gas in nuclear physics. The catastrophe theory is necessary to find connection between channels of fragments birth of different charge and masses, proceeding from the general form of a multi-dimensional phase space relief (a kind of potential function). The main result which can be taken from this theory at the given stage of researches consists in the general form of a curve of a

  5. Development theory and poverty. A review

    Francesco Farina

    2015-01-01

    This review article presents the evolution of development theory during the XX century, the measurement of poverty, the concept and the indices of multidimensional poverty. A special focus concerns the complex linkages between income inequality, poverty and institutions during the growth process of developing countries.

  6. Review of current drive theory: selected topics

    Fisch, N.J.

    1993-01-01

    Two themes in current drive theory in tokamaks are reviewed, both relevant to the progression of tokamak experiments toward the reactor regime. First, the physics of the tail electrons is reviewed. These electrons are capable of carrying enormous rf-driven electric current, and, in the course of current-drive experiments worldwide not only has the current drive effect been demonstrated, but the underlying physical description of these tail electrons has been established. Second, anticipating the presence of the energetic alpha particles that result from D-T reactions in a reactor, certain mechanisms through which these alpha particles can be used to facilitate current-drive are reviewed. (Author)

  7. Review of Mechanisms and Theories of Aging

    Gholam Reza Azari

    2006-10-01

    Full Text Available Several factors have incentive role for study of aging which includes increasing of the average and maximum of human life span, the increase in percentage of elderly in the societies and proportion of the national expenditure utilized by them. The Recent views of aging indicating that aging is extremely a complex multifactorial process despite of earlier views about definite cause aging like gene or decline of a key factor(1. This brief review tries to inspect aging at the molecular, cellular, and systemic levels; and consider interaction between genetic and environmental factors. Evolutionary theories argue that aging results from a decline in the force of natural selection. On the other hand, molecular theories emphasis on the genetically regulation of aging and argue that aging results from changing in genes. There are cellular theories that telomere theory is most famous. Stress induced aging is in this group too. free radical theory is next known way for cellular damages. Finally, we see systemic theories that contain two main groups, neuroendocrine and immunologic theories.

  8. Collision-induced absorption with exchange effects and anisotropic interactions: theory and application to H2 - H2.

    Karman, Tijs; van der Avoird, Ad; Groenenboom, Gerrit C

    2015-02-28

    We discuss three quantum mechanical formalisms for calculating collision-induced absorption spectra. First, we revisit the established theory of collision-induced absorption, assuming distinguishable molecules which interact isotropically. Then, the theory is rederived incorporating exchange effects between indistinguishable molecules. It is shown that the spectrum can no longer be written as an incoherent sum of the contributions of the different spherical components of the dipole moment. Finally, we derive an efficient method to include the effects of anisotropic interactions in the computation of the absorption spectrum. This method calculates the dipole coupling on-the-fly, which allows for the uncoupled treatment of the initial and final states without the explicit reconstruction of the many-component wave functions. The three formalisms are applied to the collision-induced rotation-translation spectra of hydrogen molecules in the far-infrared. Good agreement with experimental data is obtained. Significant effects of anisotropic interactions are observed in the far wing.

  9. Collision Avoidance Short Course: Conjunction Assessment Risk Analysis - NASA Robotic CARA. Part I: ; Theory

    Hejduk, M. D.; Frigm, Ryan C.

    2015-01-01

    Satellite conjunction assessment is perhaps the fastest growing area in space situational awareness and protection with military, civil and commercial satellite owner-operators embracing more and more sophisticated processes to avoid the avoidable - namely collisions between high value space assets and orbital debris. NASA and Centre National d'Etudes Spatiales (CNES) have collaborated to offer an introductory short course on all the major aspects of the conjunctions assessment problem. This half-day course will cover satellite conjunction dynamics and theory. Joint Space Operations Center (JsPOC) conjunction data products, major risk assessment parameters and plots, conjunction remediation decision support, and present and future challenges. This briefing represents the NASA portion of the course.

  10. A Review on Polymer Crystallization Theories

    Michael C. Zhang

    2016-12-01

    Full Text Available It is the aim of this article to review the major theories of polymer crystallization since up to now we still have not completely comprehended the underlying mechanism in a unified framework. A lack of paradigm is an indicator of immaturity of the field itself; thus, the fundamental issue of polymer crystallization remains unsolved. This paper provides an understanding of the basic hypothesis, as well as relevant physical implications and consequences of each theory without too much bias. We try to present the essential aspects of the major theories, and intuitive physical arguments over rigorously mathematical calculations are highlighted. In addition, a detailed comparison of various theories will be made in a logical and self-contained fashion. Our personal view of the existing theories is presented as well, aiming to inspire further open discussions. We expect that new theories based on the framework of kinetics with direct consideration of long-range multi-body correlation will help solve the remaining problems in the field of polymer crystallization.

  11. A review of tags anti-collision and localization protocols in RFID networks.

    Ullah, S; Alsalih, W; Alsehaim, A; Alsadhan, N

    2012-12-01

    Radio Frequency IDentification (RFID) has allowed the realization of ubiquitous tracking and monitoring of physical objects wirelessly with minimum human interactions. It plays a key role in a wide range of applications including asset tracking, contactless payment, access control, transportation and logistics, and other industrial applications. On the other side, RFID systems face several technical challenges that need to be overcome in order to achieve their potential benefits; tags collisions and localization of tagged objects are two important challenges. Numerous anti-collision and localization protocols have been proposed to address these challenges. This paper reviews the state-of-art tags' anti-collision and localization protocols, and provides a deep insight into technical issues of these protocols. The probabilistic and deterministic anti-collision protocols are critically studied and compared in terms of different parameters. We further review distance estimation, scene analysis, and proximity localization schemes and provide useful suggestions. We also introduce a new hybrid direction that utilizes power control to spatially partition the interrogation range of a reader for more efficient anti-collision and localization. Finally, we present the applications of RFID systems in healthcare sectors.

  12. Charge exchange in ion-atom collisions

    Bransden, B.H.

    1990-01-01

    Charge exchange reactions in which electrons are transferred from one ion (or atom) to another during a collision have been studied both as interesting examples of rearrangement collisions and because of important applications in plasma physics. This article reviews the modern theory developed for use at non-relativistic energies, but excluding the thermal and very low energy region. (author)

  13. Theory of nuclear fission: a review

    Mosel, U.

    1976-01-01

    General properties of nuclear fission are reviewed and related to our present knowledge of fission theory. For this purpose the basic reasons for the shape of the fission barriers are discussed and their consequences compared with experimental results on barrier shapes and structures. Special emphasis is put on the asymmetry of the fission barriers and mass-distributions and its relation to the shells of the nascent fragment shells. Finally the problem of calculating fission cross sections is discussed

  14. Theory of e+e/sup /minus// collisions at very high energy

    Peskin, M.E.

    1988-04-01

    In these lectures, the array of new phenomena are reviewed which might be discovered in electron-positron reactions conducted at energies well above the Z/degree/. Before beginning a discussion of what new phenomena we might find, or how we might uncover them, the question is addressed of why such a program of research is important. The question of what we should be looking for, and what discoveries will be the most illuminating, as we search for the next layer of fundamental physics is argued. With this background, we can then discuss in some considerable detail the contributions that the study of electron-positron collisions at high energy can make in this search

  15. The nuclear equation of state in effective relativistic field theories and pion yields in heavy-ion collisions

    Schoenhofen, M.; Cubero, M.; Gering, M.; Sambataro, M.; Feldmeier, H.; Noerenberg, W.

    1989-06-01

    Within the framework of relativistic field theory for nucleons, deltas, scalar and vector mesons, a systematic study of the nuclear equation of state and its relation to pion yields in heavy-ion collisions is presented. Not the compressibility but the effective nucleon mass at normal nuclear density turns out to be the most sensitive parameter. Effects from vaccum fluctuations are well modelled within the mean-field no-sea approximation by self-interaction terms for the scalar meson field. Incomplete thermalization in the fireball may be the reason for the low pion yields observed in heavy-ion collisions. (orig.)

  16. Effective field theory approach to open heavy flavor production in heavy-ion collisions

    Kang, Zhong-Bo [Department of Physics and Astronomy, University of California,Los Angeles, California 90095 (United States); Mani L. Bhaumik Institute for Theoretical Physics, University of California,Los Angeles, California 90095 (United States); Theoretical Division, Los Alamos National Laboratory,Los Alamos, New Mexico 87545 (United States); Ringer, Felix; Vitev, Ivan [Theoretical Division, Los Alamos National Laboratory,Los Alamos, New Mexico 87545 (United States)

    2017-03-28

    We develop a version of Soft Collinear Effective Theory (SCET) which includes finite quark masses, as well as Glauber gluons that describe the interaction of collinear partons with QCD matter. In the framework of this new effective field theory, labeled SCET{sub M,G}, we derive the massive splitting functions in the vacuum and the QCD medium for the processes Q→Qg, Q→gQ and g→QQ̄. The numerical effects due to finite quark masses are sizable and our results are consistent with the traditional approach to parton energy loss in the soft gluon emission limit. In addition, we present a new framework for including the medium-induced full splitting functions consistent with next-to-leading order calculations in QCD for inclusive hadron production. Finally, we show numerical results for the suppression of D- and B-mesons in heavy ion collisions at √(s{sub NN})=5.02 TeV and 2.76 TeV and compare to available data from the LHC.

  17. Collision dynamics of H+ + N2 at low energies based on time-dependent density-functional theory

    Yu, W.; Zhang, Y.; Zhang, F. S.; Hutton, R.; Zou, Y.; Gao, C.-Z.; Wei, B.

    2018-02-01

    Using time-dependent density-functional theory at the level of local density approximation augmented by a self-interaction correction and coupled non-adiabatically to molecular dynamics, we study, from a theoretical perspective, scattering dynamics of the proton in collisions with the N2 molecule at 30 eV. Nine different collision configurations are employed to analyze the proton energy loss spectra, electron depletion, scattering angles and self-interaction effects. Our results agree qualitatively with the experimental data and previous theoretical calculations. The discrepancies are ascribed to the limitation of the theoretical models in use. We find that self-interaction effects can significantly influence the electron capture and the excited diatomic vibrational motion, which is in consistent with other calculations. In addition, it is found that the molecular structure can be readily retrieved from the proton energy loss spectra due to a significant momentum transfer in head-on collisions.

  18. Concerning the theory of radiation cascades of atomic collisions in a solid with an arbitrary interatomic interaction potential

    Ryazanov, A.I.; Metelkin, E.V.

    1980-01-01

    Cascades of atomic collisions created by high energy particles as a result of irradiation of solids by them are considered. The solution of the problem is based on the investigation of the Boltzmann stationary kinetic equation for moving atoms. For this equation a model scattering indicatrix is constructed with an arbitrary form of the potential of interaction of moving atoms with lattice atoms. The choice of the model scattering indicatrix of atoms is determined by the normalization, the average energy loss in a single collision and by the deviation of the energy losses really occurring in the collision from the mean value, as well as by the initial kinetic equation for moving atoms. The energy distribution of moving atoms for arbitrary interatomic interaction potentials has been obtained using the constructed model scattering indicatrix. On the basis of the theory constructed a cascade is calculated with an interatomic interaction potential in the form of the Thomas-Fermi potential and the power potential. (author)

  19. Theory of phonon inelastic atom--surface scattering. I. Quantum mechanical treatment of collision dynamics

    Choi, B.H.; Poe, R.T.

    1985-01-01

    We present a systematic formulation of the atom--surface scattering dynamics which includes the vibrational states of the atoms in the solid (phonons). The properties of the total scattering wave function of the system, a representation of the interaction potential matrix, and the characteristics of the independent physical solutions are all derived from the translational invariance of the full Hamiltonian. The scattering equations in the integral forms as well as the related Green functions were also obtained. The configurational representations of the Green functions, in particular, are quite different from those of the conventional scattering theory where the collision partners are spatially localized. Various versions of the integral expression of scattering, transition, and reactance matrices were also obtained. They are useful for introducing approximation schemes. From the present formulation, some specific theoretical schemes which are more realistic compared to those that have been employed so far and at the same time capable of yielding effective ab initio computation are derived in the following paper. The time reversal invariance and the microscopic reversibility of the atom--surface scattering were discussed. The relations between the in and outgoing scattering wave functions which are satisfied in the atom--surface system and important in the transition matrix methods were presented. The phonon annihilation and creation, and the adsorption and desorption of the atom are related through the time reversal invariance, and thus the microscopic reversibility can be tested by the experiment

  20. Introduction to the study of collisions between heavy nuclei

    Bayman, B.F.

    1980-01-01

    Current investigations concerning the collisions of nuclei governed by small de Broglie wavelengths are reviewed. The wave packets localize nuclei in regions small compared to their diameters. Cross sections are examined for potential scattering, elastic scattering, quasi-molecular states, peripheral particle-transfer reactions, fusion, and deep inelastic collisions. Theories of fusion and deep inelastic collisions are summarized. This paper is in the nature of a review-tutorial. 45 references, 51 figures, 2 tables

  1. Impact of daylight saving time on road traffic collision risk: a systematic review.

    Carey, Rachel N; Sarma, Kiran M

    2017-07-02

    Bills have been put forward in the UK and Republic of Ireland proposing a move to Central European Time (CET). Proponents argue that such a change will have benefits for road safety, with daylight being shifted from the morning, when collision risk is lower, to the evening, when risk is higher. Studies examining the impact of daylight saving time (DST) on road traffic collision risk can help inform the debate on the potential road safety benefits of a move to CET. The objective of this systematic review was to examine the impact of DST on collision risk. Major electronic databases were searched, with no restrictions as to date of publication (the last search was performed in January 2017). Access to unpublished reports was requested through an international expert group. Studies that provided a quantitative analysis of the effect of DST on road safety-related outcomes were included. The primary outcomes of interest were road traffic collisions, injuries and fatalities. Twenty-four studies met the inclusion criteria. Seventeen examined the short-term impact of transitions around DST and 12 examined long-term effects. Findings from the short-term studies were inconsistent. The long-term findings suggested a positive effect of DST. However, this cannot be attributed solely to DST, as a range of road collision risk factors vary over time. The evidence from this review cannot support or refute the assertion that a permanent shift in light from morning to evening will have a road safety benefit. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  2. The theory of relativistic heavy ion collisions. [Annual] progress report, [July 1, 1993--June 30, 1994

    Shuryak, E.

    1994-07-01

    For clarity of presentation, we have divided the topics of interest into the following main topics which are discussed in this report: the dynamics of nuclear collisions at very high energies (RHIC and LHC); electromagnetic probes; the dynamics of nuclear collisions at AGS energies; and non-perturbative QCD and the physics of the phase transition

  3. Hidden crossing theory of charge exchange in H+ + He+(1 s) collisions in vicinity of maximum of cross section

    Grozdanov, Tasko P.; Solov'ev, Evgeni A.

    2018-04-01

    Within the framework of dynamical adiabatic approach the hidden crossing theory of inelastic transitions is applied to charge exchange in H+ + He+(1 s) collisions in the wide range of center of mass collision energies E cm = (1.6 -70) keV. The good agreement with experiment and molecular close coupling calculations is obtained. At low energies our 4-state results are closest to the experiment and correctly reproduce the shoulder in energy dependence of the cross section around E cm = 6 keV. The 2-state results correctly predict the position of the maximum of the cross section at E cm ≈ 40 keV, whereas 4-state results fail to correctly describe the region around the maximum. The reason for this is the fact that adiabatic approximation for a given two-state hidden crossing is applicable for values of the Schtueckelberg parameter >1. But with increase of principal quantum number N the Schtueckelberg parameter decreases as N -3. That is why the 4-state approach involving higher excited states fails at smaller collision energies E cm ≈ 15 keV, while the 2-state approximation which involves low lying states can be extended to higher collision energies.

  4. Microinstability theory in tokamaks: a review

    Tang, W.M.

    1977-06-01

    Significant investigations in the area of tokamak microinstability theory are reviewed. Emphasis is given to the work covering the period from 1970 through 1976. Special attention is focused on low-frequency electrostatic drift-type modes, which are generally believed to be the dominant tokamak microinstabilities under normal operating conditions. The basic linear formalism including electromagnetic (finite beta) modifications is presented along with a general survey of the numerous papers investigating specific linear and nonlinear effects on these modes. Estimates of the associated anomalous transport and confinement times are discussed, and a summary of relevant experimental results is given. Studies of the nonelectrostatic and high-frequency instabilities associated with the presence of high energy ions from neutral beam injection (or with the presence of alpha particles from fusion reactions) are also surveyed

  5. Microinstability theory in tokamaks: a review

    Tang, W.M.

    1977-06-01

    Significant investigations in the area of tokamak microinstability theory are reviewed. Emphasis is given to the work covering the period from 1970 through 1976. Special attention is focused on low-frequency electrostatic drift-type modes, which are generally believed to be the dominant tokamak microinstabilities under normal operating conditions. The basic linear formalism including electromagnetic (finite beta) modifications is presented along with a general survey of the numerous papers investigating specific linear and nonlinear effects on these modes. Estimates of the associated anomalous transport and confinement times are discussed, and a summary of relevant experimental results is given. Studies of the nonelectrostatic and high-frequency instabilities associated with the presence of high energy ions from neutral beam injection (or with the presence of alpha particles from fusion reactions) are also surveyed.

  6. Microscopic theory of nuclear fission: a review

    Schunck, N.; Robledo, L. M.

    2016-11-01

    This article reviews how nuclear fission is described within nuclear density functional theory. A distinction should be made between spontaneous fission, where half-lives are the main observables and quantum tunnelling the essential concept, and induced fission, where the focus is on fragment properties and explicitly time-dependent approaches are often invoked. Overall, the cornerstone of the density functional theory approach to fission is the energy density functional formalism. The basic tenets of this method, including some well-known tools such as the Hartree-Fock-Bogoliubov (HFB) theory, effective two-body nuclear potentials such as the Skyrme and Gogny force, finite-temperature extensions and beyond mean-field corrections, are presented succinctly. The energy density functional approach is often combined with the hypothesis that the time-scale of the large amplitude collective motion driving the system to fission is slow compared to typical time-scales of nucleons inside the nucleus. In practice, this hypothesis of adiabaticity is implemented by introducing (a few) collective variables and mapping out the many-body Schrödinger equation into a collective Schrödinger-like equation for the nuclear wave-packet. The region of the collective space where the system transitions from one nucleus to two (or more) fragments defines what are called the scission configurations. The inertia tensor that enters the kinetic energy term of the collective Schrödinger-like equation is one of the most essential ingredients of the theory, since it includes the response of the system to small changes in the collective variables. For this reason, the two main approximations used to compute this inertia tensor, the adiabatic time-dependent HFB and the generator coordinate method, are presented in detail, both in their general formulation and in their most common approximations. The collective inertia tensor enters also the Wentzel-Kramers-Brillouin (WKB) formula used to extract

  7. Theory of and effects from elastoplasticity in nucleus-nucleus collisions

    Noerenberg, W.; Technische Hochschule Darmstadt

    1985-02-01

    Elastoplasticity of finite Fermi systems results from a coherent coupling between collective and intrinsic degrees of freedom and subsequent equilibration essentially due to two-body collisions. Within a non-markovian transport-theoretical approach referred to as dissipative diabatic dynamics (DDD), elastoplastical forms the link between giant vibrations and overdamped motion of nuclear. Obersvable effects resulting from this non-markovian behaviour in nucleus-nucleus collisions are discussed. (orig.)

  8. Exercise-Based Interventions for Injury Prevention in Tackle Collision Ball Sports: A Systematic Review.

    Sewry, Nicola; Verhagen, Evert; Lambert, Mike; van Mechelen, Willem; Viljoen, Wayne; Readhead, Clint; Brown, James

    2017-09-01

    The injury burden in collision sports is relatively high compared to other team sports. Therefore, participants in these sports would benefit by having effective injury prevention programs. Exercise-based interventions have successfully reduced injuries in soccer, but evidence on exercise-based interventions in tackle collision sports is limited. The objective of this review is to systematically examine the evidence of exercise-based intervention programs reducing injuries in tackle collision sports. PubMed, EBSCOHost, and Web of Science were searched for articles published between January 1995 and December 2015. The methodological quality was assessed using an adapted Cochrane Bone Joint and Muscle Trauma Group quality assessment tool. The inclusion criteria were (1) (randomized) control trials and observational studies; (2) sporting codes: American, Australian and Gaelic Football, rugby union, and rugby league; (3) participants of any age or sex; (4) exercise-based, prehabilitative intervention; and (5) primary outcome was injury rate or incidence (injury risk). The exclusion criteria were (1) unavailability of full-text; and (2) article unavailable in English. Nine studies with a total of 3517 participants were included in this review. Seven of these studies showed a significant decrease in injury risk. These studies included three sporting codes and various age groups, making it difficult to make inferences. The two highest methodological quality studies found no effect of an exercise-based intervention on injury risk. There is evidence that exercise-based injury preventions can be beneficial in reducing injury risk in collision sports, but more studies of high methodological quality are required.

  9. International Experience in Upper Echelon Theory: Literature Review

    Đerđa Dino

    2017-09-01

    Full Text Available Background: The international experience of top managers is an evolving research within the upper echelon theory; therefore this literature review summarizes everything made so far.

  10. Review of experiments and calculation procedures for ship collision and grounding damage

    Liu, Bin; Pedersen, Preben Terndrup; Zhu, Ling

    2018-01-01

    Abstract The paper presents a review of experiments and calculation procedures for the resistances of ship structural components subjected to impact loadings. The purpose of the paper is to highlight the importance of large-scale collision and grounding experiments and to discuss the technical...... and material characteristics. In recent literature, analytical and numerical calculations provide relatively accurate prediction of the purely plastic responses of ship structures under impact loads, but universal approaches have not been found for fracture predictions. The existing formulae for failure...

  11. Book Review: Market Liquidity: Theory, Evidence, and Policy

    Boscan, Luis

    2014-01-01

    Review of: Market Liquidity: Theory, Evidence, and Policy / by Thierry Foucault, Marco Pagano and Ailsa Röell. Oxford University Press. April 2013.......Review of: Market Liquidity: Theory, Evidence, and Policy / by Thierry Foucault, Marco Pagano and Ailsa Röell. Oxford University Press. April 2013....

  12. Maximum entropy theory of recoil charge distributions in electron-capture collisions

    Aberg, T.; Blomberg, A.; Tulkki, J.; Goscinski, O.

    1984-01-01

    A generalized Fermi-Dirac distribution is derived and applied to charge-state distributions in single collisions between multiply charged ions and rare-gas atoms. It relates multiple electron loss in single-electron capture to multiple ionization in multiphoton absorption and discloses inner-shell vacancy formation in double- and triple-electron capture

  13. The Hopelessness Theory of Depression: A Quarter Century in Review

    Liu, Richard T.; Kleiman, Evan M.; Nestor, Bridget A.; Cheek, Shayna M.

    2015-01-01

    Since the formulation of the hopelessness theory of depression (Abramson, Metalsky, & Alloy, 1989) a quarter century ago, it has garnered considerable interest. The current paper presents a systematic review of this theory including its subsequent elaborations (Rose and Abramson’s [1992] developmental elaboration, Abela and Sarin’s [2002] weakest-link approach, Panzarella, Alloy, and Whitehouse’s [2006] expansion of the hopelessness theory, and the hopelessness theory of suicide [Abramson et ...

  14. Equilibrium theory of island biogeography: A review

    Angela D. Yu; Simon A. Lei

    2001-01-01

    The topography, climatic pattern, location, and origin of islands generate unique patterns of species distribution. The equilibrium theory of island biogeography creates a general framework in which the study of taxon distribution and broad island trends may be conducted. Critical components of the equilibrium theory include the species-area relationship, island-...

  15. Review Essay: A Journey through Grounded Theory

    Paula Krüger

    2007-01-01

    Full Text Available In "Constructing Grounded Theory", Kathy CHARMAZ guides the reader through the research process. Starting with a look back at the history of grounded theory, she explains how to gather rich data, code it, write memos, and compose the first draft. Through various examples from her own research CHARMAZ provides the reader not only with a theoretical description of how to construct a grounded theory but also with a way of seeing how new questions emerge from the data and new theory is built from it. She highlights central concepts, definitions, and useful questions, and offers the reader flexible guidelines to design and conduct a research project. Because of this, the book will be very useful for novices as well as for experts and (PhD- students in the late stages of their theses; it is a must-have for everyone who works with/on (constructivist grounded theory. URN: urn:nbn:de:0114-fqs0701256

  16. Experimental review of light quark spectroscopy from e+e- production and γγ collisions

    Toki, W.H.

    1987-07-01

    This is an experimental review of light quark spectroscopy from e + e - production and γγ collision results presented at the 2nd International Conference on Hadron Spectroscopy at KEK, Japan. The recent results in γγ production have evidence for the J/sup PC/ = 1 ++ , E/f 1 (1420) and D/f 1 (1285), mesons from the TPC and Mark II collaborations and upper limits for pseudoscalar resonances from the Crystal Ball collaboration. The results in J/psi reactions include D/f 1 (1285) meson production in radiative decays and a complete measurement of the hadronic decays into pseudoscalar-vector pairs from the DM2 collaboration and evidence for phi phi production in radiative decays and a study of the iota line shape from the Mark III collaboration. A short review of simple theoretical ideas is presented

  17. The Child-Langmuir law and analytical theory of collisionless to collision-dominated sheaths

    Benilov, M S

    2009-01-01

    This paper is concerned with summarizing simple analytical models of space-charge sheaths and tracing their relation to the Child-Langmuir model of an ion sheath. The topics discussed include the Child-Langmuir law and model of a collisionless ion sheath, the Mott-Gurney law and model of a collision-dominated ion sheath, the Bohm model of a collisionless ion-electron sheath, the Su-Lam-Cohen model of a collision-dominated ion-electron sheath, ion sheaths with arbitrary collisionality, high-accuracy boundary conditions for the Child-Langmuir and Mott-Gurney models of an ion sheath and the mathematical sense of Child-Langmuir type models of an ion sheath from the point of view of modern theoretical physics.

  18. Perturbative theory of higher-order collision-enhanced wave mixing

    Trebino, R.; Rahn, L.A.

    1989-01-01

    This paper reports on collision-enhanced resonances which represent an interesting class of nonlinear- optical processes. They occur because collisional dephasing can rephase quantum-mechanical amplitudes that ordinarily cancel out exactly, thereby allowing otherwise unobservable wave-mixing resonances to be seen. This is an especially interesting phenomenon because these resonances are coherent effects that are induced by an incoherent process (collisional dephasing). First predicted in the late 1970s and eventually observed in 1981, these novel effects have now been seen in a wide variety of four-wave-mixing experiments, ranging from self-focusing to coherent anti-Stokes Raman spectroscopy. Recently, the authors have extended these observations to higher order, where the authors have shown both experimentally and theoretically the higher-order, collision-enhanced effects exist in nonlinear optics, appearing as subharmonics of two-photon resonances. Indeed, the authors have found that collision-enhanced processes are ideal systems for studying higher-order, nonlinear-optical effects because very high orders can be made to contribute with little or no saturation braodening. Experiments on sodium in a flame using six- and eight-wave-mixing geometries have revealed still higher-order effects (at least as high- order as χ (13) )

  19. Final Report for Project ``Theory of ultra-relativistic heavy-ion collisions''

    Ulrich W. Heinz

    2012-11-09

    In the course of this project the Ohio State University group led by the PI, Professor Ulrich Heinz, developed a comprehensive theoretical picture of the dynamical evolution of ultra-relativistic heavy-ion collisions and of the numerous experimental observables that can be used to diagnose the evolving and short-lived hot and dense fireball created in such collisions. Starting from a qualitative understanding of the main features based on earlier research during the last decade of the twentieth century on collisions at lower energies, the group exploited newly developed theoretical tools and the stream of new high-quality data from the Relativistic Heavy Ion Collider at Brookhaven National Laboratory (which started operations in the summer of the year 2000) to arrive at an increasingly quantitative description of the experimentally observed phenomena. Work done at Ohio State University (OSU) was instrumental in the discovery during the years 2001-2003 that quark-gluon plasma (QGP) created in nuclear collisions at RHIC behaves like an almost perfect liquid with minimal viscosity. The tool of relativistic fluid dynamics for viscous liquids developed at OSU in the years 2005-2007 opened the possibility to quantitatively determine the value of the QGP viscosity empirically from experimental measurements of the collective flow patterns established in the collisions. A first quantitative extraction of the QGP shear viscosity, with controlled theoretical uncertainty estimates, was achieved during the last year of this project in 2010. OSU has paved the way for a transition of the field of relativistic heavy-ion physics from a qualitative discovery stage to a new stage of quantitative precision in the description of quark-gluon plasma properties. To gain confidence in the precision of our theoretical understanding of quark-gluon plasma dynamics, one must test it on a large set of experimentally measured observables. This achievement report demonstrates that we have, at

  20. Theory of uses and gratifications: A Review

    Filipović Jelena

    2012-01-01

    The main goal of the uses and gratifications theory was to explain what kind of the needs people can fulfill through media usage. According to this theory: audience is active and individuals use media to achieve some goals and gratifications. The gratifications that audience can accomplish through media usage are numerous: usefulness (people use media to execute some task), intention (media content determines the usage), selectivity according to person's interests and resistance to influences...

  1. Legislator voting and behavioral science theory: a systematic review.

    Tung, Gregory J; Vernick, Jon S; Reiney, Erin V; Gielen, Andrea C

    2012-11-01

    To examine the application of behavioral science theories to explain the voting behavior of legislators for public health policies. We conducted a systematic review to identify studies that examined factors associated with legislator support, intention to vote, or actual votes on public health policies, emphasizing those grounded in behavior science theory. Twenty-one papers met our inclusion criteria, and 6 were explicitly grounded in a behavioral science theory. Behavioral science theories, and the theory of planned behavior in particular, provide a framework for understanding legislator voting behavior and can be used by advocates to advance pro-health policies.

  2. The Hopelessness Theory of Depression: A Quarter Century in Review.

    Liu, Richard T; Kleiman, Evan M; Nestor, Bridget A; Cheek, Shayna M

    2015-12-01

    Since the formulation of the hopelessness theory of depression (Abramson, Metalsky, & Alloy, 1989) a quarter century ago, it has garnered considerable interest. The current paper presents a systematic review of this theory including its subsequent elaborations (Rose and Abramson's [1992] developmental elaboration, Abela and Sarin's [2002] weakest-link approach, Panzarella, Alloy, and Whitehouse's [2006] expansion of the hopelessness theory, and the hopelessness theory of suicide [Abramson et al., 2000]), followed by recommendations for future study. Although empirical support was consistently found for several major components of the hopelessness theory, further work is required assessing this theory in relation to clinically significant phenomena. Among the most significant hindrances to advancement in this area is the frequent conceptual confusion between the hopelessness theory and the reformulated learned helplessness theory.

  3. The Hopelessness Theory of Depression: A Quarter Century in Review

    Liu, Richard T.; Kleiman, Evan M.; Nestor, Bridget A.; Cheek, Shayna M.

    2015-01-01

    Since the formulation of the hopelessness theory of depression (Abramson, Metalsky, & Alloy, 1989) a quarter century ago, it has garnered considerable interest. The current paper presents a systematic review of this theory including its subsequent elaborations (Rose and Abramson’s [1992] developmental elaboration, Abela and Sarin’s [2002] weakest-link approach, Panzarella, Alloy, and Whitehouse’s [2006] expansion of the hopelessness theory, and the hopelessness theory of suicide [Abramson et al., 2000]), followed by recommendations for future study. Although empirical support was consistently found for several major components of the hopelessness theory, further work is required assessing this theory in relation to clinically significant phenomena. Among the most significant hindrances to advancement in this area is the frequent conceptual confusion between the hopelessness theory and the reformulated learned helplessness theory. PMID:26709338

  4. Time-dependent observables in heavy ion collisions. Part II. In search of pressure isotropization in the φ 4 theory

    Kovchegov, Yuri V.; Wu, Bin

    2018-03-01

    To understand the dynamics of thermalization in heavy ion collisions in the perturbative framework it is essential to first find corrections to the free-streaming classical gluon fields of the McLerran-Venugopalan model. The corrections that lead to deviations from free streaming (and that dominate at late proper time) would provide evidence for the onset of isotropization (and, possibly, thermalization) of the produced medium. To find such corrections we calculate the late-time two-point Green function and the energy-momentum tensor due to a single 2 → 2 scattering process involving two classical fields. To make the calculation tractable we employ the scalar φ 4 theory instead of QCD. We compare our exact diagrammatic results for these quantities to those in kinetic theory and find disagreement between the two. The disagreement is in the dependence on the proper time τ and, for the case of the two-point function, is also in the dependence on the space-time rapidity η: the exact diagrammatic calculation is, in fact, consistent with the free streaming scenario. Kinetic theory predicts a build-up of longitudinal pressure, which, however, is not observed in the exact calculation. We conclude that we find no evidence for the beginning of the transition from the free-streaming classical fields to the kinetic theory description of the produced matter after a single 2 → 2 rescattering.

  5. A Review on ϕ Meson Production in Heavy-Ion Collision

    Md. Nasim

    2015-01-01

    Full Text Available The main aim of the relativistic heavy-ion experiment is to create extremely hot and dense matter and study the QCD phase structure. With this motivation, experimental program started in the early 1990s at the Brookhaven Alternating Gradient Synchrotron (AGS and the CERN Super Proton Synchrotron (SPS followed by Relativistic Heavy Ion Collider (RHIC at Brookhaven and recently at Large Hadron Collider (LHC at CERN. These experiments allowed us to study the QCD matter from center-of-mass energies (sNN 4.75 GeV to 2.76 TeV. The ϕ meson, due to its unique properties, is considered as a good probe to study the QCD matter created in relativistic collisions. In this paper we present a review on the measurements of ϕ meson production in heavy-ion experiments. Mainly, we discuss the energy dependence of ϕ meson invariant yield and the production mechanism, strangeness enhancement, parton energy loss, and partonic collectivity in nucleus-nucleus collisions. Effect of later stage hadronic rescattering on elliptic flow (v2 of proton is also discussed relative to corresponding effect on ϕ meson v2.

  6. Fundamental measure theory for hard-sphere mixtures: a review

    Roth, Roland

    2010-01-01

    Hard-sphere systems are one of the fundamental model systems of statistical physics and represent an important reference system for molecular or colloidal systems with soft repulsive or attractive interactions in addition to hard-core repulsion at short distances. Density functional theory for classical systems, as one of the core theoretical approaches of statistical physics of fluids and solids, has to be able to treat such an important system successfully and accurately. Fundamental measure theory is up to date the most successful and most accurate density functional theory for hard-sphere mixtures. Since its introduction fundamental measure theory has been applied to many problems, tested against computer simulations, and further developed in many respects. The literature on fundamental measure theory is already large and is growing fast. This review aims to provide a starting point for readers new to fundamental measure theory and an overview of important developments. (topical review)

  7. Comprehensive Review on Divisible Load Theory: Concepts, Strategies, and Approaches

    Shamsollah Ghanbari

    2014-01-01

    Full Text Available There is extensive literature concerning the divisible load theory. The divisible load theory is mainly applied for scheduling in the area of distributed computing. It is based on the fact that the load can be divided into some arbitrarily independent parts, in which each part can be processed independently by a processor. This paper reviews the literature concerning the divisible load theory, while focusing on the details of the basic concepts, approaches, strategies, typologies, and open problems.

  8. Attachment theory: A review of research

    Polovina Nada

    2005-01-01

    Full Text Available Research of attachment is numerous and versatile. They differ according to problems addressed, methodology applied (longitudinal studies, studies with horizontal designs, different instruments used, different methods of data analysis, and characteristics of samples involved (concerning age socio/economic status, family ecology. The research is commonly relied on the core assumptions of the theory itself, and the shared characteristic is orientation to explore complex phenomena of human experience and functioning. From the vast variety of research only those who most directly test the basic assumptions of the attachment theory are focused and addressed in the paper: representation of patterns of attachment in the childhood and adulthood, stability and change of attachment security from infancy to early adulthood, transgenerational transmission of attachment characteristics, the place and the role of attachment behavioral system in the personality development. The aim of the paper is to highlight the basic research and theory issues and directions, and illustrate them with concrete research date.

  9. Theory of uses and gratifications: A Review

    Filipović Jelena

    2012-01-01

    Full Text Available The main goal of the uses and gratifications theory was to explain what kind of the needs people can fulfill through media usage. According to this theory: audience is active and individuals use media to achieve some goals and gratifications. The gratifications that audience can accomplish through media usage are numerous: usefulness (people use media to execute some task, intention (media content determines the usage, selectivity according to person's interests and resistance to influences (members of the audience values media content independently to media persuasion. Uses and gratifications studies have dealt with all kinds of communication tools, such as: television, newspapers, video games, Internet, etc. Even though uses and gratifications theory appears to be very successful in understanding the motives for media usage, some issues remain to be solved and studied in more details in methodological terms.

  10. Using grounded theory as a method for rigorously reviewing literature

    Wolfswinkel, J.; Furtmueller-Ettinger, Elfriede; Wilderom, Celeste P.M.

    2013-01-01

    This paper offers guidance to conducting a rigorous literature review. We present this in the form of a five-stage process in which we use Grounded Theory as a method. We first probe the guidelines explicated by Webster and Watson, and then we show the added value of Grounded Theory for rigorously

  11. A review of organizational buyer behaviour models and theories ...

    Over the years, models have been developed, and theories propounded, to explain the behavior of industrial buyers on the one hand and the nature of the dyadic relationship between organizational buyers and sellers on the other hand. This paper is an attempt at a review of the major models and theories in extant ...

  12. A Review of Group Systems Theory

    Connors, Joanie V.; Caple, Richard B.

    2005-01-01

    The ability to see interpersonal and group processes beyond the individual level is an essential skill for group therapists (Crouch, Bloch & Wanlass, 1994; Dies, 1994; Fuhriman & Burlingame, 1994). In addition to interpersonal therapy models (e.g., Sullivan and Yalom), there are a number of systems theory models that offer a broad array of…

  13. Creation of ultra-high-pressure shocks by the collision of laser-accelerated disks: experiment and theory

    Rosen, M.D.; Phillion, D.W.; Price, R.H.; Campbell, E.M.; Obenschain, S.P.; Whitlock, R.R.; McLean, E.A.; Ripin, B.H.

    1983-01-01

    We have used the SHIVA laser system to accelerate carbon disks to speeds in excess of 100 km/sec. The 3KJ/3 ns pulse, on a 1 mm diameter spot of a single disk produced a conventional shock of about 5 MB. The laser energy can, however, be stored in kinetic motion of this accelerated disk and delivered (reconverted to thermal energy) upon impact with another carbon disk. This collision occurs in a time much shorter than the 3 ns pulse, thus acting as a power amplifier. The shock pressures measured upon impact are estimated to be in the 20 MB range, thus demonstrating the amplification power of this colliding disk technique in creating ultra-high pressures. Theory and computer simulations of this process will be discussed, and compared with the experiment

  14. BOOK REVIEW: Supersymmetry: Theory, Experiment and Cosmology

    Jones, Tim

    2008-06-01

    This volume presents a comprehensive introduction to supersymmetry, concentrating mainly on the Minimal Supersymmetric Standard Model (MSSM) and its possible embedding in a grand unified theory, but also including material on supergravity, non-perturbative aspects of supersymmetry, string theory and cosmology. There is an excellent self-contained appendix on the standard model which could be read first; other appendices provide introductions to spinor representations of the Lorentz group, superfields, and cosmology, and there is a short appendix listing the MSSM renormalisation group beta-functions. The appendices in fact occupy over a quarter of the volume. Substantial knowledge of quantum field theory is required of the reader; and also a working knowledge of group theory as employed in the construction of particle physics models: while there is some useful material on this in the section on grand unification, an appendix on it might perhaps have been a useful addition. Supersymmetry is introduced via the particle physicist's concern with the hierarchy problem and developed in the component formalism beginning with the Wess Zumino model and proceeding to supersymmetric gauge theories. The treatment is detailed and authoritative; the author has 25 years of high-level research experience in the area and it shows. The level of presentation is high, and difficult concepts are explained clearly. The examples and associated hints are excellent. One topic I would have liked to see more on is the renormalisation of supersymmetric theories; presentation of the explicit calculation of the anomalous dimension of a chiral superfield (gamma) at one loop for at least the Wess Zumino model might perhaps have been pedagogically useful. Associated, perhaps, with this omission is an inconsistency in the definition of gamma; the sign of gamma in the treatment in section 8.3.2 clearly differs from its sign in the appendix section E.3. In the text the formalism of supersymmetry is

  15. Review of Test Theory and Methods.

    1981-01-01

    literature, although some books , technical reports, and unpub- lished literature have been included where relevant. The focus of the review is on practical...1977) and Abu-Sayf (1977) developed new versions of formula scores, and Molenaar (1977) took a Bayesian approach to correcting for random guessing. The...Snow’s (1977) book on aptitude and instructional methods is a landmark review of the research on the interaction between instructional methods and

  16. Alignment and orientation in ion/endash/atom collisions

    Kimura, M.; Lane, N.F.

    1987-01-01

    Recent progress in the theoretical study of alignment and orientation in atom-atom and ion-atom collisions at intermediate energies is reviewed. Recent systematic studies of the alignment and orientation of electronic charge cloud distributions of excited states resulting from such collisions clearly have provided more detailed information about the underlying collision dynamics. However, since accurate determination of these parameters is quite difficult, both theoretically and experimentally, a close collaboration between theory and experiment is necessary for a deeper understanding of the collision dynamics. A more complete approach, where the full density matrix is determined, is also discussed

  17. A review on recent light particle correlation data from heavy ion collisions at intermediate and low energies

    Ardouin, D.

    1996-01-01

    A review of recent two-particle interferometry data for heavy-ion collisions in the domain of energy between ten and a few hundreds of MeV/nucleon is presented. Not only identical particles but unlike particle correlations have been used successfully as a probe for space-time dynamics of the collision process. Due to the availability of new dedicated charged particles or photon multi-detectors, the field of particle interferometry is moving to a good level of quantitative description: excitation energy and impact parameter dependences are now provided which should stimulate additional theoretical calculations for two-particle cross sections and emission of light fragments. (author)

  18. Learning Organisation Review--A "Good" Theory Perspective

    Santa, Mijalce

    2015-01-01

    Purpose: The purpose of this paper is to perform integrative literature review of the learning organisation (LO) concept, on the basis of the results of the literature review to assess the concept on the principles of "good" theory, and provide future avenues for LO concept clarification and development. Design/methodology/approach: The…

  19. Do Advance Organizers Facilitate Learning? A Review of Subsumption Theory.

    McEneany, John E.

    1990-01-01

    A review of four studies conducted by Ausubel raises serious doubts about the efficacy of advance organizers under a variety of circumstances. In addition, this review questions the adequacy of definitions for two central notions of subsumption theory (discriminability and advance organizer). (IAH)

  20. Intracranial meningioma as primary presentation for an undiagnosed collision metastatic breast cancer: Case report and literature review.

    Farrag, Ashraf; Ansari, Jawaher; Ali, Muhammad; Sunbuli, Ghanem; Kassem, Hassan; Al Hamad, Abdul-Aziz

    2018-05-01

    Intracranial metastasis from breast cancer is a relatively common finding, however, the appearance of breast cancer metastasis in a meningioma is very rare. Several cases of tumor-to-tumor metastasis and collision tumors have been reported previously, with meningioma being implicated as the most common benign intracranial neoplasm to harbour the metastasis. Occasionally, the discovery of a tumor-to-meningioma metastasis may herald the diagnosis of an occult primary malignancy. Careful histopathological assessment of the resected meningioma specimen is pivotal to the management of these patients, as this will alter the treatment plan and prognosis considerably. Intracranial meningioma with collision breast cancer as primary presentation of an undiagnosed metastatic breast cancer is extremely rare. The current study presents a case of intracranial meningioma with collision breast cancer as a primary presentation, and reviews the available evidence for this unusual disease entity.

  1. A review of the theory and phenomenology of lepton pair production

    Hwa, R.C.

    1978-05-01

    Recent experimental data and theoretical developments on the production of lepton pairs in hadron collisions are reviewed. With emphasis on the interplay between theory and experiment, the relevance of theoretical calculations to the data available at present energies is critically examined. The Drell-Yan mechanism is found to be phenomenologically dominant provided that the parton distribution functions contain effects of gluon radiation in a narrow cone. Explicit QCD perturbative calculations of the non-Drell-Yan type yield results that are apparently important at large transverse momenta, but are contradicted by subsequent data at 400 GeV and below. A consistent picture in the parton model is sketched. Further experiments to probe the basic mechanism are suggested. (author)

  2. On the limits of Köhler activation theory: how do collision and coalescence affect the activation of aerosols?

    Hoffmann, Fabian

    2017-07-01

    Activation is necessary to form a cloud droplet from an aerosol, and it is widely accepted that it occurs as soon as a wetted aerosol grows beyond its critical radius. Traditional Köhler theory assumes that this growth is driven by the diffusion of water vapor. However, if the wetted aerosols are large enough, the coalescence of two or more particles is an additional process for accumulating sufficient water for activation. This transition from diffusional to collectional growth marks the limit of traditional Köhler theory and it is studied using a Lagrangian cloud model in which aerosols and cloud droplets are represented by individually simulated particles within large-eddy simulations of shallow cumuli. It is shown that the activation of aerosols larger than 0. 1 µm in dry radius can be affected by collision and coalescence, and its contribution increases with a power-law relation toward larger radii and becomes the only process for the activation of aerosols larger than 0. 4-0. 8 µm depending on aerosol concentration. Due to the natural scarcity of the affected aerosols, the amount of aerosols that are activated by collection is small, with a maximum of 1 in 10 000 activations. The fraction increases as the aerosol concentration increases, but decreases again as the number of aerosols becomes too high and the particles too small to cause collections. Moreover, activation by collection is found to affect primarily aerosols that have been entrained above the cloud base.

  3. Topological cross sections in hadron-nucleus collisions and multiple scattering theory

    Zoller, V.R.

    1987-01-01

    The multiple scattering theory supplemented with cutting rules of Abramovsky, V.A., Gribov, V.N., Kancheli, O.V. is applied to calculation of the hadron-nucleus interaction cross sections. In contrast to standard Glauber approach neither smalness of the interaction radius compared to the nuclear radii nor Gaussian form of the hN-interaction profile function are assumed. The theory of the supercritical pomeron are used. However all the results are more general and do not depend on the parametrization of the pomeron pole amplitude. The region of validity of the widely used approximate formulae for topological and total hA-interaction cross sections are discussed

  4. Simple Closed-Form Expression for Penning Reaction Rate Coefficients for Cold Molecular Collisions by Non-Hermitian Time-Independent Adiabatic Scattering Theory.

    Pawlak, Mariusz; Ben-Asher, Anael; Moiseyev, Nimrod

    2018-01-09

    We present a simple expression and its derivation for reaction rate coefficients for cold anisotropic collision experiments based on adiabatic variational theory and time-independent non-Hermitian scattering theory. We demonstrate that only the eigenenergies of the resulting one-dimensional Schrödinger equation for different complex adiabats are required. The expression is applied to calculate the Penning ionization rate coefficients of an excited metastable helium atom with molecular hydrogen in an energy range spanning from hundreds of kelvins down to the millikelvin regime. Except for trivial quantities like the masses of the nuclei and the bond length of the diatomic molecule participating in the collision, one needs as input data only the complex potential energy surface (CPES). In calculations, we used recently obtained ab initio CPES by D. Bhattacharya et al. ( J. Chem. Theory Comput. 2017 , 13 , 1682 - 1690 ) without fitting parameters. The results show good accord with current measurements ( Nat. Phys. 2017 , 13 , 35 - 38 ).

  5. Continuum states in ion-atom collisions

    Garibotti, C.R. (Centro Atomico Bariloche and CONICET (Argentina)); Barrachina, R.O. (Centro Atomico Bariloche and CONICET (Argentina))

    1994-03-01

    We review the experimental and theoretical situation for ionization collisions of nude ions with neutral gas atoms, at intermediate and high impact energies. We consider particularly that part of the electron spectrum where emission is larger, corresponding to the joint action to the two ions. We discuss the evidence of this two-center interaction and how it is described by current theories. (orig.)

  6. Theory of high energy collision processes. Final report, June 1, 1969-May 31, 1984

    Wu, T.T.

    1984-01-01

    We have developed a comprehensive theory for scattering processes at extremely high energies. On the basis of relativistic quantum field theories with or without isotopic spin, we have obtained a simple physical picture, called the impact picture, which gives a number of unusual predictions. Many of these have been verified experimentally, including the increasing total cross sections, the increasing total elastic cross sections, the moving dip, and the rising plateau. An especially accurate experimental verification of the prediction of increasing total cross section has been provided by the CERN p anti p Collider at a c.m. energy of 540 GeV. All of these predictions were obtained by resumming the perturbation series. The natural next step is to look for important physical effects that cannot be seen by any method of resumming the perturbation series. One such method is to find nonperturbative effects already present on the classical level; another is to construct exactly solvable models of quantum field theory. Both approaches have been pursued. Recent theoretical results include the possible occurrence of indeterminate-mass particles, dynamic determination of coupling constants, a solvable Z 2 lattice gauge theory, a generalization of the method of helicity amplitudes, classical models of confinement, and a monopole as a short-distance probe. 152 publications are listed

  7. BOOK REVIEW: Vortex Methods: Theory and Practice

    Cottet, G.-H.; Koumoutsakos, P. D.

    2001-03-01

    The book Vortex Methods: Theory and Practice presents a comprehensive account of the numerical technique for solving fluid flow problems. It provides a very nice balance between the theoretical development and analysis of the various techniques and their practical implementation. In fact, the presentation of the rigorous mathematical analysis of these methods instills confidence in their implementation. The book goes into some detail on the more recent developments that attempt to account for viscous effects, in particular the presence of viscous boundary layers in some flows of interest. The presentation is very readable, with most points illustrated with well-chosen examples, some quite sophisticated. It is a very worthy reference book that should appeal to a large body of readers, from those interested in the mathematical analysis of the methods to practitioners of computational fluid dynamics. The use of the book as a text is compromised by its lack of exercises for students, but it could form the basis of a graduate special topics course. Juan Lopez

  8. Projective geometry solved problems and theory review

    Fortuna, Elisabetta; Pardini, Rita

    2016-01-01

    This book starts with a concise but rigorous overview of the basic notions of projective geometry, using straightforward and modern language. The goal is not only to establish the notation and terminology used, but also to offer the reader a quick survey of the subject matter. In the second part, the book presents more than 200 solved problems, for many of which several alternative solutions are provided. The level of difficulty of the exercises varies considerably: they range from computations to harder problems of a more theoretical nature, up to some actual complements of the theory. The structure of the text allows the reader to use the solutions of the exercises both to master the basic notions and techniques and to further their knowledge of the subject, thus learning some classical results not covered in the first part of the book. The book addresses the needs of undergraduate and graduate students in the theoretical and applied sciences, and will especially benefit those readers with a solid grasp of ...

  9. Tsallis Entropy Theory for Modeling in Water Engineering: A Review

    Vijay P. Singh

    2017-11-01

    Full Text Available Water engineering is an amalgam of engineering (e.g., hydraulics, hydrology, irrigation, ecosystems, environment, water resources and non-engineering (e.g., social, economic, political aspects that are needed for planning, designing and managing water systems. These aspects and the associated issues have been dealt with in the literature using different techniques that are based on different concepts and assumptions. A fundamental question that still remains is: Can we develop a unifying theory for addressing these? The second law of thermodynamics permits us to develop a theory that helps address these in a unified manner. This theory can be referred to as the entropy theory. The thermodynamic entropy theory is analogous to the Shannon entropy or the information theory. Perhaps, the most popular generalization of the Shannon entropy is the Tsallis entropy. The Tsallis entropy has been applied to a wide spectrum of problems in water engineering. This paper provides an overview of Tsallis entropy theory in water engineering. After some basic description of entropy and Tsallis entropy, a review of its applications in water engineering is presented, based on three types of problems: (1 problems requiring entropy maximization; (2 problems requiring coupling Tsallis entropy theory with another theory; and (3 problems involving physical relations.

  10. Self-consistent field theory of collisions: Orbital equations with asymptotic sources and self-averaged potentials

    Hahn, Y.K., E-mail: ykhahn22@verizon.net

    2014-12-15

    The self-consistent field theory of collisions is formulated, incorporating the unique dynamics generated by the self-averaged potentials. The bound state Hartree–Fock approach is extended for the first time to scattering states, by properly resolving the principal difficulties of non-integrable continuum orbitals and imposing complex asymptotic conditions. The recently developed asymptotic source theory provides the natural theoretical basis, as the asymptotic conditions are completely transferred to the source terms and the new scattering function is made fullyintegrable. The scattering solutions can then be directly expressed in terms of bound state HF configurations, establishing the relationship between the bound and scattering state solutions. Alternatively, the integrable spin orbitals are generated by constructing the individual orbital equations that contain asymptotic sources and self-averaged potentials. However, the orbital energies are not determined by the equations, and a special channel energy fixing procedure is developed to secure the solutions. It is also shown that the variational construction of the orbital equations has intrinsic ambiguities that are generally associated with the self-consistent approach. On the other hand, when a small subset of open channels is included in the source term, the solutions are only partiallyintegrable, but the individual open channels can then be treated more simply by properly selecting the orbital energies. The configuration mixing and channel coupling are then necessary to complete the solution. The new theory improves the earlier continuum HF model. - Highlights: • First extension of HF to scattering states, with proper asymptotic conditions. • Orbital equations with asymptotic sources and integrable orbital solutions. • Construction of self-averaged potentials, and orbital energy fixing. • Channel coupling and configuration mixing, involving the new orbitals. • Critical evaluation of the

  11. Theory of Mind in Autistic Family: A Literature Review

    Aline Abreu e Andrade

    2013-12-01

    Full Text Available Theory of mind is the people ability to understand their own mental states and the others. People with autism have significant deficit in this ability. The objective of this study was to conduct a systematic literature review about theory of mind studies conducted with relatives of people with autistic spectrum disorders. We used as databases BVS Medline, Web of Science, Academic Search Premier and Psy Articles in search of articles. Nine articles were selected and the results indicated inconclusive data on the existence of theory of mind deficits in relatives of people with autistic spectrum disorders. Thus, future studies are aimed to shed light on the topic.

  12. Kinetic theory of a spherical probe in a stationary collision-dominated isothermal plasma

    Brailsford, A.D.

    1977-01-01

    Constitutive equations for the charge carrier fluxes in a stationary collision-dominated isothermal plasma surrounding a spherical electrode are derived, from the Boltzmann equation, by a moment method using a two-stream Maxwellian distribution of the type introduced by Lees. In contrast to previous treatments, the constraint of uniform temperature is imposed and its importance emphasized. This condition, together with particle conservation, is shown to necessitate the use of a four-parameter Lees distribution and leads to generalized hydrodynamic equations. These are shown to reduce to conventional flux equations in terms of diffusion and mobility components only when the fields are spatially slowly varying. In addition, boundary conditions are derived by the same formalism. They are formulated for typical physical processes which may be operative at a real probe surface. As an example, the effect of the nonlinearity on the pure diffusion problem is analyzed in detail in the Appendix. A semiquantitative discussion of the current-voltage characteristics for negative probe potentials is also presented. It is shown that the charge carrier distribution around the probe conforms to the ''free-fall'' model only at low probe voltages. Otherwise, the model proposed by Su and Lam holds. The domain covered by the present analysis is determined by the following conditions on the probe radius r/sub p/, mean free path l, and Debye length lambda: (i) l 3 very-much-less-thanlambda 2 r/sub p/, (ii) (e vertical-barphi/sub p/ vertical-barl/kTr/sub p/) 2 /l 2 for l>lambda, where phi/sub p/ is the probe voltage. Analytic approximations to the current-voltage characteristics in both these regimes are presented

  13. Transport theory applied to hadron and light fragment production in high energy nucleus-nucleus collisions

    Schuermann, B.; Malfliet, R.; Mies, S.; Zwermann, W.

    1984-01-01

    Foundations of the transport theory for studying K + , K - , π - and light fragment production in nucleus-nucleus interactions at high energies are given. Inclusive production of protons, K + and π - in the Ne+NaF reaction at 400 MeV and 21 GeV/nucleon is consdered, their differential cross sections are caculated. Differential cross sections of K - and π - production in Si+Si → K + +X and Ne+NaF → π - +X reactions at the energy of 2.1 GeV/nucleon, their energy dependence are estimated. Comparison of the calculated and experimental data is graphically presented. The model of the transport theory is shown to successfully reproduce inclusive spectra of different particles (p, d, π, K + , K - ) in a wide energy range of incident particles (from 400 MeV to 2 GeV/nucleon). This approach can be generalized for lower energies by generating a mean nuclear potentiasl field

  14. Influence of collision frequency on neoclassical polarization current

    Imada, K; Wilson, H R

    2009-01-01

    A kinetic theory for the evolution of magnetic islands is considered in a tokamak plasma, in both the low (ν i i >> εω) collision frequency limits (ν i is the ion collision frequency, ε is the inverse aspect ratio and ω is the island propagation frequency in the E x B rest frame). The calculation of the bootstrap current perturbation in the presence of a magnetic island is reviewed, and is confirmed to be independent of ω and the collision frequency regime. The neoclassical polarization current perturbation is calculated in the two collision frequency limits (within the banana regime). The result in the collisional limit is in agreement with a fluid theory. The effect of collisions in the 'dissipation layer' at the trapped/passing boundary is also considered, for ν i i /εω] 1/2 , where r is a weak logarithmic function of √ν i /εω.

  15. From collision to collaboration - Integrating informal recyclers and re-use operators in Europe: A review.

    Scheinberg, Anne; Nesić, Jelena; Savain, Rachel; Luppi, Pietro; Sinnott, Portia; Petean, Flaviu; Pop, Flaviu

    2016-09-01

    The European Union hosts some of the world's most developed waste management systems and an ambitious policy commitment to the circular economy. The existence of informal recycling and re-use activities in Europe has been vigorously denied until quite recently, and remains a very challenging subject for the European solid waste management sector, as well as for European government and private institutions. In countries ranging from Malta to Macedonia and from France to Turkey, informal recyclers excluded from legal recycling niches increasingly collide with formalised and controlled European Union approaches to urban waste management, packaging recovery schemes, formal re-use enterprises, and extended producer responsibility systems.This review focuses on the period from 2004 through the first half of 2016. The 78 sources on European (and neighbouring) informal recycling and re-use are contextualised with global sources and experience. The articles focus on informal recovery in and at the borders of the European Union, document the conflicts and collisions, and elaborate some constructive approaches towards legalisation, integration, and reconciliation. The overarching recommendation, to locate the issue of informal recovery and integration in the framework of the European circular economy package, is supported by four specific pillars of an integration strategy: Documentation, legalisation, occupational and enterprise recognition, and preparation for structural integration. © The Author(s) 2016.

  16. Pion production in 3He collisions on complex nuclei: a comparison of theory with experiment

    Fulcher, L.P.; Banerjee, M.K.

    1976-01-01

    The BLSZ theory of inclusive pion production is applied to the (p,π + ) and the ( 3 He,π 0 ) reactions on 12 C. The calculations are based on plane waves for the projectile and pion wave functions and are compared with experiments. The effects of distortion are considered. The magnitudes of the (p,π + ) reaction cross sections are comparable to the experimental values, but for the ( 3 He,π 0 ) case the theoretical results are four or five orders of magnitude larger than the experiments

  17. Effective collision frequency due to ion-acoustic instability: Theory and simulations

    Hellinger, Petr; Trávníček, Pavel; Menietti, J. D.

    2004-01-01

    Roč. 31, č. 10 (2004), L10806 ISSN 0094-8276 R&D Projects: GA MŠk ME 500; GA AV ČR IAA3042403 Grant - others:ESA PRODEX(XE) 14529/00/NL/SFe; NASA (US) NAG5-11942 Institutional research plan: CEZ:AV0Z3042911 Keywords : Magnetospheric Physics: Plasma waves and instabilities * Space Plasma Physics: Kinetic and MHD theory * Space Plasma Physics: Magnetic reconnection Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.378, year: 2004

  18. On the theory of excitation transfer process in slow collisions between identical particles

    Chibisov, M.I.

    1978-01-01

    Asymptotics has been investigated at R → infinity (R is internuclear distance) of exchange interaction for the quasimolecule of two identical one-electron atoms. It is shown that the theory of exchange interaction developed previously which does not take into account the symmetry on permutations of electron is not rigid. The exchange contribution to term splitting in alkali metal atoms determines the effective cross section for transfer of excitation at 10 3 K. The Van der Waals contribution is less than the exchange one. The cross section is of the order of 10 -14 cm 2 . The cross section dependence on temperature is weak, sigma approximately ln 2 T

  19. Wellness: A Review of Theory and Measurement for Counselors

    Roscoe, Lauren J.

    2009-01-01

    Wellness is considered the paradigm of counseling and development (J. E. Myers, 1991, 1992). However, researchers have failed to agree on a definition or on the dimensional structure of wellness. Furthermore, existing quantitative wellness instruments are inadequate for capturing the complexity of wellness. The author reviews wellness theory and…

  20. Bridging the gap between event-by-event fluctuation measurements and theory predictions in relativistic nuclear collisions

    Braun-Munzinger, P., E-mail: p.braun-munzinger@gsi.de [Extreme Matter Institute EMMI, GSI, Darmstadt (Germany); Physikalisches Institut, Universität Heidelberg, Heidelberg (Germany); Rustamov, A., E-mail: a.rustamov@cern.ch [Physikalisches Institut, Universität Heidelberg, Heidelberg (Germany); National Nuclear Research Center, Baku (Azerbaijan); Stachel, J., E-mail: stachel@physi.uni-heidelberg.de [Physikalisches Institut, Universität Heidelberg, Heidelberg (Germany)

    2017-04-15

    We develop methods to deal with non-dynamical contributions to event-by-event fluctuation measurements of net-particle numbers in relativistic nuclear collisions. These contributions arise from impact parameter fluctuations and from the requirement of overall net-baryon number or net-charge conservation and may mask the dynamical fluctuations of interest, such as those due to critical endpoints in the QCD phase diagram. Within a model of independent particle sources we derive formulae for net-particle fluctuations and develop a rigorous approach to take into account contributions from participant fluctuations in realistic experimental environments and at any cumulant order. Interestingly, contributions from participant fluctuations to the second and third cumulants of net-baryon distributions are found to vanish at mid-rapidity for LHC energies while higher cumulants of even order are non-zero even when the net-baryon number at mid-rapidity is zero. At lower beam energies the effect of participant fluctuations increases and induces spurious higher moments. The necessary corrections become large and need to be carefully taken into account before comparison to theory. We also provide a procedure for selecting the optimal phase–space coverage of particles for fluctuation analyses and discuss quantitatively the necessary correction due to global charge conservation.

  1. Electromagnetic Radiation from QCD Matter: Theory Overview

    Shen, Chun

    2016-12-15

    Recent theory developments in electromagnetic radiation from relativistic heavy-ion collisions are reviewed. Electromagnetic observables can serve as a thermometer, a viscometer, and tomographic probes to the collision system. The current status of the “direct photon flow puzzle” is highlighted.

  2. Actinide collisions for QED and superheavy elements with the time-dependent Hartree-Fock theory and the Balian-Vénéroni variational principle

    Kedziora David J.

    2011-10-01

    Full Text Available Collisions of actinide nuclei form, during very short times of few zs (10−21 s, the heaviest ensembles of interacting nucleons available on Earth. Such collisions are used to produce super-strong electric fields by the huge number of interacting protons to test spontaneous positron-electron pair emission (vacuum decay predicted by the quantum electrodynamics (QED theory. Multi-nucleon transfer in actinide collisions could also be used as an alternative way to fusion in order to produce neutron-rich heavy and superheavy elements thanks to inverse quasifission mechanisms. Actinide collisions are studied in a dynamical quantum microscopic approach. The three-dimensional time-dependent Hartree-Fock (TDHF code tdhf3d is used with a full Skyrme energy density functional to investigate the time evolution of expectation values of one-body operators, such as fragment position and particle number. This code is also used to compute the dispersion of the particle numbers (e.g., widths of fragment mass and charge distributions from TDHF transfer probabilities, on the one hand, and using the BalianVeneroni variational principle, on the other hand. A first application to test QED is discussed. Collision times in 238U+238U are computed to determine the optimum energy for the observation of the vacuum decay. It is shown that the initial orientation strongly affects the collision times and reaction mechanism. The highest collision times predicted by TDHF in this reaction are of the order of ~ 4 zs at a center of mass energy of 1200 MeV. According to modern calculations based on the Dirac equation, the collision times at Ecm > 1 GeV are sufficient to allow spontaneous electron-positron pair emission from QED vacuum decay, in case of bare uranium ion collision. A second application of actinide collisions to produce neutron-rich transfermiums is discussed. A new inverse quasifission mechanism associated to a specific orientation of the nuclei is proposed to

  3. A temperature and mass dependence of the linear Boltzmann collision operator from group theory point of view

    Saveliev, V.

    1996-01-01

    The Lie group of the transformations affecting the parameters of the linear Boltzmann collision operator such as temperature of background gas and ratio of masses of colliding particles and molecules is discovered. The group also describes the conservation laws for collisions and main symmetries of the collision operator. New algebraic properties of the collision operator are derived. Transformations acting on the variables and parameters and leaving the linear Boltzmann kinetic equation invariant are found. For the constant collision frequency the integral representation of solutions for nonuniform case in terms of the distribution function of particles drifting in a gas with zero temperature is deduced. The new exact relaxation solutions are obtained too. copyright 1996 American Institute of Physics

  4. Exact multiple scattering theory of two-nucleus collisions including the Pauli principle

    Gurvitz, S.A.

    1981-01-01

    Exact equations for two-nucleus scattering are derived in which the effects of the Pauli principle are fully included. Our method exploits a modified equation for the scattering of two identical nucleons, which is obtained at the beginning. Considering proton-nucleus scattering we found that the resulting amplitude has two components, one resembling a multiple scattering series for distinguishable particles, and the other a distorted (A-1) nucleon cluster exchange. For elastic pA scattering the multiple scattering amplitude is found in the form of an optical potential expansion. We show that the Kerman-McManus-Thaler theory of the optical potential could be easily modified to include the effects of antisymmetrization of the projectile with the target nucleons. Nucleus-nucleus scattering is studied first for distinguishable target and beam nucleus. Afterwards the Pauli principle is included, where only the case of deuteron-nucleus scattering is discussed in detail. The resulting amplitude has four components. Two of them correspond to modified multiple scattering expansions and the others are distorted (A-1)- and (A-2)- nucleon cluster exchange. The result for d-A scattering is extended to the general case of nucleus-nucleus scattering. The equations are simple to use and as such constitute an improvement over existing schemes

  5. Review of equipment aging theory and technology. Final report

    Carfagno, S.P.; Gibson, R.J.

    1980-09-01

    The theory and technology of equipment aging is reviewed, particularly as they relate to the qualification of safety-system equipment for nuclear power generating stations. A fundamental degradation model is developed, and its relation to more restricted models (e.g., Arrhenius and inverse-stress models) is shown. The most common theoretical and empirical models of aging are introduced, and limitations on their practical application are analyzed. Reliability theory and its application to the acceleration of aging are also discussed. A compendium of aging data for materials and components, including degradation mechanisms, failure modes and activation energies, is included

  6. Review of equipment aging theory and technology. Final report

    Carfagno, S.P.; Gibson, R.J.

    1980-09-01

    The theory and technology of equipment aging is reviewed, particularly as they relate to the qualification of safety-system equipment for nuclear power generating stations. A fundamental degradation model is developed, and its relation to more restricted models (e.g., Arrhenius and inverse-stress models) is shown. The most common theoretical and empirical models of aging are introduced, and limitations on their practical application are analyzed. Reliability theory and its application to the acceleration of aging are also discussed. A compendium of aging data for materials and components, including degradation mechanisms, failure modes and activation energies, is included.

  7. Multiple scattering theory of X-ray absorption. A review

    Fonda, L.

    1991-11-01

    We review the basic elements of the theory of X-ray absorption using the tools provided by the theory of multiple scattering. A momentum space approach of clear physical insight is used where the final formulas expressing EXAFS and XANES, i.e. the structures appearing in the absorption coefficient above the edge of a deep core level threshold, are given in terms of eigenstates of the photoelectron momentum. A simple graphic representation is given for the multiple scattering function. (author). 38 refs, 4 figs, 1 tab

  8. Theory of high-energy-collision processes. Technical progress report, January 1-December 31, 1981

    1982-01-01

    Progress is described in the following areas: (1) several years ago, surprisingly simple expressions were obtained for the differential cross sections of e + e - → μ + μ - γ and e + e - → e + e - γ at high energies. Such simple expressions were generalized to twelve other similar radiative processes in QED and QCD. Afterwards, it was found that these results can be derived easily with the help of helicity amplitudes. This method is being investigated for many other radiative processes; (2) in the two-dimensional Ising model, the horizontal and vertical interaction energies are usually taken to be different. When this idea of different interactions in different directions is applied to the Z 2 lattice gauge theory in four dimensions, a limiting case is found which is exactly solvable. Contrary to numerical calculations at the symmetry point, the phase transition is found to be of second order; (3) on the subject of supersymmetry, general helicity and spin sum rules were obtained for massless and massive supermultiplets, and a functional integral approach was found as a natural setting for Witten's criterion for the occurrence of dynamic symmetry breaking of supersymmetry. A systematic and exhaustive analysis of explicit soft breaking of global supersymmetry has also been carried out using the methods of superfields; (4) the renormalization of the massless Thirring model in the neighborhood of g = -π/2 was studied. The results are consistent with those found previously by placing the model on a lattice; and (5) in studying the effect of laboratory temperature on scattering processes, it was found that transport phenomena play an important role. As a preparation for this study, an exactly solvable case of the nonlinear Boltzmann equation has been found and studied

  9. Theory, Instrumentation and Applications of Magnetoelastic Resonance Sensors: A Review

    Grimes, Craig A.; Roy, Somnath C.; Rani, Sanju; Cai, Qingyun

    2011-01-01

    Thick-film magnetoelastic sensors vibrate mechanically in response to a time varying magnetic excitation field. The mechanical vibrations of the magnetostrictive magnetoelastic material launch, in turn, a magnetic field by which the sensor can be monitored. Magnetic field telemetry enables contact-less, remote-query operation that has enabled many practical uses of the sensor platform. This paper builds upon a review paper we published in Sensors in 2002 (Grimes, C.A.; et al. Sensors 2002, 2, 294–313), presenting a comprehensive review on the theory, operating principles, instrumentation and key applications of magnetoelastic sensing technology. PMID:22163768

  10. Theory, Instrumentation and Applications of Magnetoelastic Resonance Sensors: A Review

    Craig A. Grimes

    2011-03-01

    Full Text Available Thick-film magnetoelastic sensors vibrate mechanically in response to a time varying magnetic excitation field. The mechanical vibrations of the magnetostrictive magnetoelastic material launch, in turn, a magnetic field by which the sensor can be monitored. Magnetic field telemetry enables contact-less, remote-query operation that has enabled many practical uses of the sensor platform. This paper builds upon a review paper we published in Sensors in 2002 (Grimes, C.A.; et al. Sensors 2002, 2, 294-313, presenting a comprehensive review on the theory, operating principles, instrumentation and key applications of magnetoelastic sensing technology.

  11. Research on hidden variable theories: A review of recent progresses

    Genovese, Marco

    2005-01-01

    Quantum Mechanics (QM) is one of the pillars of modern physics: an impressive amount of experiments have confirmed this theory and many technological applications are based on it. Nevertheless, at one century since its development, various aspects concerning its very foundations still remain to be clarified. Among them, the transition from a microscopic probabilistic world into a macroscopic deterministic one and quantum non-locality. A possible way out from these problems would be if QM represents a statistical approximation of an unknown deterministic theory. This review is addressed to present the most recent progresses on the studies related to hidden variable theories (HVT), both from an experimental and a theoretical point of view, giving a larger emphasis to results with a direct experimental application. More in details, the first part of the review is a historical introduction to this problem. The Einstein-Podolsky-Rosen argument and the first discussions about HVT are introduced, describing the fundamental Bell's proposal for a general experimental test of every local HVT and the first attempts to realise it. The second part of the review is devoted to elucidate the recent progresses toward a conclusive Bell inequalities experiment obtained with entangled photons and other physical systems. Finally, the last sections are targeted to shortly discuss non-local HVT

  12. Research on hidden variable theories: A review of recent progresses

    Genovese, Marco [Istituto Elettrotecnico Nazionale Galileo Ferraris, Strada delle Cacce 91, 10135 Torino (Italy)]. E-mail: genovese@ien.it

    2005-07-01

    Quantum Mechanics (QM) is one of the pillars of modern physics: an impressive amount of experiments have confirmed this theory and many technological applications are based on it. Nevertheless, at one century since its development, various aspects concerning its very foundations still remain to be clarified. Among them, the transition from a microscopic probabilistic world into a macroscopic deterministic one and quantum non-locality. A possible way out from these problems would be if QM represents a statistical approximation of an unknown deterministic theory. This review is addressed to present the most recent progresses on the studies related to hidden variable theories (HVT), both from an experimental and a theoretical point of view, giving a larger emphasis to results with a direct experimental application. More in details, the first part of the review is a historical introduction to this problem. The Einstein-Podolsky-Rosen argument and the first discussions about HVT are introduced, describing the fundamental Bell's proposal for a general experimental test of every local HVT and the first attempts to realise it. The second part of the review is devoted to elucidate the recent progresses toward a conclusive Bell inequalities experiment obtained with entangled photons and other physical systems. Finally, the last sections are targeted to shortly discuss non-local HVT.

  13. Effective collision frequency method in the theory of the conductivity of Coulomb systems. II. Strong interion interaction and plasma structure

    Bobrov, V.B.; Triger, S.A.

    1994-01-01

    The effective collision frequency method developed earlier by the authors for Coulomb systems characterized by strong interion interaction is developed further. An explicit expression is obtained for the effective electron collision frequency on the basis of the exact diagram representation obtained in Part I and the use of the model of a one-component plasma as initial approximation. The description of plasma structure in the corresponding approximation is considered. 25 refs

  14. Book Review: Inventing the Market: Smith, Hegel & Political Theory by Liza Herzog

    Boscan, Luis

    2014-01-01

    Review of: Inventing the Market: Smith, Hegel & Political Theory. Liza Herzog. Oxford University Press. April 2013.......Review of: Inventing the Market: Smith, Hegel & Political Theory. Liza Herzog. Oxford University Press. April 2013....

  15. Collision cross sections of N2 by H+ impact at keV energies within time-dependent density-functional theory

    Yu, W.; Gao, C.-Z.; Zhang, Y.; Zhang, F. S.; Hutton, R.; Zou, Y.; Wei, B.

    2018-03-01

    We calculate electron capture and ionization cross sections of N2 impacted by the H+ projectile at keV energies. To this end, we employ the time-dependent density-functional theory coupled nonadiabatically to molecular dynamics. To avoid the explicit treatment of the complex density matrix in the calculation of cross sections, we propose an approximate method based on the assumption of constant ionization rate over the period of the projectile passing the absorbing boundary. Our results agree reasonably well with experimental data and semi-empirical results within the measurement uncertainties in the considered energy range. The discrepancies are mainly attributed to the inadequate description of exchange-correlation functional and the crude approximation for constant ionization rate. Although the present approach does not predict the experiments quantitatively for collision energies below 10 keV, it is still helpful to calculate total cross sections of ion-molecule collisions within a certain energy range.

  16. Quantum chromodynamics at high energy, theory and phenomenology at hadron colliders; Chromodynamique quantique a haute energie, theorie et phenomenologie appliquee aux collisions de hadrons

    Marquet, C

    2006-09-15

    When probing small distances inside a hadron, one can resolve its partonic constituents: quarks and gluons that obey the laws of perturbative Quantum Chromodynamics (QCD). This substructure reveals itself in hadronic collisions characterized by a large momentum transfer: in such collisions, a hadron acts like a collection of partons whose interactions can be described in QCD. In a collision at moderate energy, a hadron looks dilute and the partons interact incoherently. As the collision energy increases, the parton density inside the hadron grows. Eventually, at some energy much bigger than the momentum transfer, one enters the saturation regime of QCD: the gluon density has become so large that collective effects are important. We introduce a formalism suitable to study hadronic collisions in the high-energy limit in QCD, and the transition to the saturation regime. In this framework, we derive known results that are needed to present our personal contributions and we compute different cross-sections in the context of hard diffraction and particle production. We study the transition to the saturation regime as given by the Balitsky-Kovchegov equation. In particular we derive properties of its solutions.We apply our results to deep inelastic scattering and show that, in the energy range of the HERA collider, the predictions of high-energy QCD are in good agreement with the data. We also consider jet production in hadronic collisions and discuss the possibility to test saturation at the Large Hadron Collider. (author)

  17. Roads and bats: a meta-analysis and review of the evidence on vehicle collisions and barrier effects.

    Fensome, Amy Grace; Mathews, Fiona

    2016-10-01

    Roads are a potential threat to bat conservation. In addition to the direct risk of collision of bats with vehicles, roads could pose a threat to bat populations as a result of habitat loss, degradation and fragmentation, and could act as barriers to movements of bats between habitats.We performed a systematic review of the literature and conducted meta-analyses to assess the threat posed by roads to bats as a result of 1) collisions between bats and vehicles and 2) roads acting as barriers to movements of bats.Based on collated records of 1207 bat road casualties in Europe, we found that low-flying species are more prone to collisions than high-flying species, and that juveniles are more vulnerable to collisions than adults. In addition, meta-analysis identified a significant bias towards male casualties. Casualties included rare species such as Barbastella barbastellus and geographically restricted species such as Rhinolophus species.The bias towards male casualties could be indicative of greater natal philopatry or lower dispersal among females, or of sexual segregation in habitats of varying quality, i.e. females may occupy better quality habitats than males, and road density may be lower in better quality habitats.Whether or not roads act as barriers to the movement of bats depends on a complex interplay of habitat and species-specific behaviour. For example, the presence of favourable habitat for bats - notably woodland - was found in this review to be linked with significantly reduced barrier effects but a heightened risk of collision.Our data suggest that roads do pose a threat to bats. Future research should assess the contribution of traffic noise and street lighting to the barrier effect of roads. Where new road schemes are monitored by ecological practitioners, it is vital that consistent protocols are employed to ensure that bat activity can be compared before and after the road is built. Evidence from such research should be used to minimize the risks

  18. A systematic review of grounded theory studies in physiotherapy.

    Ali, Nancy; May, Stephen; Grafton, Kate

    2018-05-23

    This systematic review aimed at appraising the methodological rigor of grounded theory research published in the field of physiotherapy to assess how the methodology is understood and applied. A secondary aim was to provide research implications drawn from the findings to guide future grounded theory methodology (GTM) research. A systematic search was conducted in MEDLINE, CINHAL, SPORT Discus, Science Direct, PubMed, Scopus, and Web of Science to identify studies in the field of physiotherapy that reported using GTM and/or methods in the study title and/or abstract. The descriptive characteristics and methodological quality of eligible studies were examined using grounded theory methodology assessment guidelines. The review included 68 studies conducted between 1998 and 2017. The findings showed that GTM is becoming increasingly used by physiotherapy researchers. Thirty-six studies (53%) demonstrated a good understanding and appropriate application of GTM. Thirty-two studies (47%) presented descriptive findings and were considered to be of poor methodological quality. There are several key tenets of GTM that are integral to the iterative process of qualitative theorizing and need to be applied throughout all research practices including sampling, data collection, and analysis.

  19. BOOK REVIEW: The Scalar-Tensor Theory of Gravitation

    Fujii, Yasunori; Maeda, Kei-ichi

    2003-10-01

    Since the scalar-tensor theory of gravitation was proposed almost 50 years ago, it has recently become a robust alternative theory to Einstein's general relativity due to the fact that it appears to represent the lower level of a more fundamental theory and can serve both as a phenomenological theory to explain the recently observed acceleration of the universe, and to solve the cosmological constant problem. To my knowledge The Scalar-Tensor Theory of Gravitation by Y Fujii and K Maeda is the first book to develop a modern view on this topic and is one of the latest titles in the well-presented Cambridge Monographs on Mathematical Physics series. This book is an excellent readable introduction and up-to-date review of the subject. The discussion is well organized; after a comprehensible introduction to the Brans-Dicke theory and the important role played by conformal transformations, the authors review cosmologies with the cosmological constant and how the scalar-tensor theory can serve to explain the accelerating universe, including discussions on dark energy, quintessence and braneworld cosmologies. The book ends with a chapter devoted to quantum effects. To make easy the lectures of the book, each chapter starts with a summary of the subject to be dealt with. As the book proceeds, important issues like conformal frames and the weak equivalence principle are fully discussed. As the authors warn in the preface, the book is not encyclopedic (from my point of view the list of references is fairly short, for example, but this is a minor drawback) and the choice of included topics corresponds to the authors' interests. Nevertheless, the book seems to cover a broad range of the most essential aspects of the subject. Long and 'boring' mathematical derivations are left to appendices so as not to interrupt the flow of the reasoning, allowing the reader to focus on the physical aspects of each subject. These appendices are a valuable help in entering into the mathematical

  20. Integration of ICT in teaching and learning: a review of theories ...

    In deriving these factors, several theories can be considered. This paper reviews six of these theories, namely, Theory of Reasoned Action (TRA), the Technology Acceptance Model (TAM), the Technology-Organisation-Environment (TOE) framework, the Theory of Planned Behaviour (TPB), the Unified Theory of Acceptance ...

  1. A review of recent results on spread F theory

    Ossakow, S.L.

    1979-01-01

    Ionospheric Spread F was discovered some four decades ago. Yet only in the past few years has significant progress been made in the theoretical explanation of such phenomena. In particular, considerable effort has been expended to explain equatorial Spread F and the attendant satellite signal propagation scintillation phenomena. The present review dwells mainly in this low latitude area. The various linear plasma instabilities thought to initiate equatorial Spread F are discussed. Recent theoretical and numerical simulation studies of the nonlinear evolution of the collisional Rayleigh-Taylor instability in equatorial Spread F are reviewed. Also, analytical studies of rising equatorial Spread F bubbles in the collisional and collisionless Rayleigh-Taylor regime are discussed, as well as the nohlinear saturation of instabilities in these two regimes. Current theories on very small scale (< approx 10 meters) size irregularities observed by radar backscatter during equatorial Spread F and their relation to the larger wavelength scintillation causing irregularities are discussed. Application of turbulence theory to equatorial Spread F phenomena is reviewed. Remaining problems to be dealt with at equatorial latitudes are summarized. (Auth.)

  2. A Systematic Review of Literature Using Business Systems Theory

    Rana, Mohammad Bakhtiar; Morgan, Glenn

    2015-01-01

    , international business (IB) studies do not tend to borrow much from this sub-field. This paper reviews BST literature from 1992 to 2015 and seeks to identify its contributions and gaps, in ways that can be helpful for future research in IB. Trend analysis of BST literature and mapping this sub-field suggests......Business system theory (BST) lies at the intersection of organization theory, political economy and sociology. It is gaining incremental attention in the field of management, particularly in cross-border and comparative studies of the structure, strategy and management of multinationals. Yet...... that the BST research stream can be identified in relation to four ‘broad themes’ which we describe as junctures- i.e. comparative business systems, internationalisation and MNC management, organizational capability and innovation, and transnational communities. Mapping and pattern recognition of the ‘themes...

  3. Review of game theory applications for situation awareness

    Blasch, Erik; Shen, Dan; Pham, Khanh D.; Chen, Genshe

    2015-05-01

    Game theoretical methods have been used for spectral awareness, space situational awareness (SSA), cyber situational awareness (CSA), and Intelligence, Surveillance, and Reconnaissance situation awareness (ISA). Each of these cases, awareness is supported by sensor estimation for assessment and the situation is determined from the actions of multiple players. Game theory assumes rational actors in a defined scenario; however, variations in social, cultural and behavioral factors include the dynamic nature of the context. In a dynamic data-driven application system (DDDAS), modeling must include both the measurements but also how models are used by different actors with different priorities. In this paper, we highlight the applications of game theory by reviewing the literature to determine the current state of the art and future needs. Future developments would include building towards knowledge awareness with information technology (e.g., data aggregation, access, indexing); multiscale analysis (e.g., space, time, and frequency), and software methods (e.g., architectures, cloud computing, protocols).

  4. Gravity, quantum theory and the evaporation of black holes. [Review

    Wilkins, D C [Tata Inst. of Fundamental Research, Bombay (India)

    1977-06-01

    Recent developments in blackhole physics are reviewed. It is pointed out that black hole thermodynamics is a theory of exceptional unity and elegance. Starting from the discovery of thermal emission from black holes (evaporation process) by Hawking, the four thermodynamic laws they obey, the nonzero temperature and entropy, angular momentum and charge of the black holes are dealt with. The influence of this thermodynamics on quantum theory and gravitation is discussed in relation to particle creation and quantum gravity. The formation and basic properties of black holes are described in terms of significant milestones. The decade-long development of black hole thermodynamics from 1963-73 is highlighted. The fundamental issues arising in particle physics as a result of these discoveries are discussed.

  5. Main Tendencies in the Problem of the Legal Collisions Study in Modern Science of the Law Theory

    Kristina V. Ahmetjanova

    2015-06-01

    Full Text Available In the article the main tendencies within studying of problems of legal collisions in modern jurisprudence are considered. The main attention is paid to a question of consideration of the specified problem from a position of various types of law understanding. By results of the conducted research, author comes to a conclusion that the most part of researches on problems of collisions in law is sustained in the spirit of legal positivism, however there is a number of works in which attempt of consideration of legal collisions from a position of sociological type of understanding of the right is traced. Tendency, according to the author, is the most significant and the specified subject having a certain potential to carrying out further actual researches on.

  6. THE SECOND DEMOGRAPHIC TRANSITION THEORY: A Review and Appraisal.

    Zaidi, Batool; Morgan, S Philip

    2017-07-01

    References to the second demographic transition (SDT) concept/theoretical framework have increased dramatically in the last two decades. The SDT predicts unilinear change toward very low fertility and a diversity of union and family types. The primary driver of these changes is a powerful, inevitable and irreversible shift in attitudes and norms in the direction of greater individual freedom and self-actualization. First, we describe the origin of this framework and its evolution over time. Second, we review the empirical fit of the framework to major changes in demographic and family behavior in the U.S., the West, and beyond. As has been the case for other unilinear, developmental theories of demographic/family change, the SDT failed to predict many contemporary patterns of change/difference. Finally, we review previous critiques and identify fundamental weaknesses of this perspective, and provide brief comparisons to selected alternative approaches.

  7. Theories of how the school environment impacts on student health: systematic review and synthesis.

    Bonell, C P; Fletcher, A; Jamal, F; Wells, H; Harden, A; Murphy, S; Thomas, J

    2013-11-01

    Public-health interventions informed by theory can be more effective but complex interventions often use insufficiently complex theories. We systematically reviewed theories of how school environments influence health. We included 37 reports drawing on 24 theories. Narrative synthesis summarised and categorised theories. We then produced an integrated theory of school environment influences on student health. This integrated theory could inform complex interventions such as health promoting schools programmes. Using systematic reviews to develop theories of change might be useful for other types of 'complex' public-health interventions addressing risks at the individual and community levels. © 2013 Published by Elsevier Ltd.

  8. Jets in heavy ion collisions

    Nattrass, Christine

    2017-01-01

    High energy collisions of heavy nuclei permit the study of nuclear matter at temperatures and energy densities so high that the fundamental theory for strong interactions, QCD, predicts a phase transition to a plasma of quarks and gluons. This matter, called a Quark Gluon Plasma (QGP), has been studied experimentally for the last decade and has been observed to be a strongly interacting liquid with a low viscosity. High energy partons created early in the collision interact with the QGP and provide unique probes of its properties. Hard partons fragment into collimated sprays of particles called jets and have been studied through measurements of single particles, correlations between particles, and measurements of fully reconstructed jets. These measurements demonstrate partonic energy loss in the QGP and constrain the QGP’s properties. Measurements of the jet structure give insight into the mechanism of this energy loss. The information we have learned from studies of jets and challenges for the field will be reviewed. (paper)

  9. Innovation adoption: a review of theories and constructs.

    Wisdom, Jennifer P; Chor, Ka Ho Brian; Hoagwood, Kimberly E; Horwitz, Sarah M

    2014-07-01

    Many theoretical frameworks seek to describe the dynamic process of the implementation of innovations. Little is known, however, about factors related to decisions to adopt innovations and how the likelihood of adoption of innovations can be increased. Using a narrative synthesis approach, this paper compared constructs theorized to be related to adoption of innovations proposed in existing theoretical frameworks in order to identify characteristics likely to increase adoption of innovations. The overall goal was to identify elements across adoption frameworks that are potentially modifiable and, thus, might be employed to improve the adoption of evidence-based practices. The review identified 20 theoretical frameworks that could be grouped into two broad categories: theories that mainly address the adoption process (N = 10) and theories that address adoption within the context of implementation, diffusion, dissemination, and/or sustainability (N = 10). Constructs of leadership, operational size and structure, innovation fit with norms and values, and attitudes/motivation toward innovations each are mentioned in at least half of the theories, though there were no consistent definitions of measures for these constructs. A lack of precise definitions and measurement of constructs suggests further work is needed to increase our understanding of adoption of innovations.

  10. Innovation Adoption: A Review of Theories and Constructs

    Chor, Ka Ho Brian; Hoagwood, Kimberly E.; Horwitz, Sarah M.

    2013-01-01

    Many theoretical frameworks seek to describe the dynamic process of the implementation of innovations. Little is known, however, about factors related to decisions to adopt innovations and how the likelihood of adoption of innovations can be increased. Using a narrative synthesis approach, this paper compared constructs theorized to be related to adoption of innovations proposed in existing theoretical frameworks in order to identify characteristics likely to increase adoption of innovations. The overall goal was to identify elements across adoption frameworks that are potentially modifiable and, thus, might be employed to improve the adoption of evidence-based practices. The review identified 20 theoretical frameworks that could be grouped into two broad categories: theories that mainly address the adoption process (N = 10) and theories that address adoption within the context of implementation, diffusion, dissemination, and/or sustainability (N = 10). Constructs of leadership, operational size and structure, innovation fit with norms and values, and attitudes/motivation toward innovations each are mentioned in at least half of the theories, though there were no consistent definitions of measures for these constructs. A lack of precise definitions and measurement of constructs suggests further work is needed to increase our understanding of adoption of innovations. PMID:23549911

  11. Review and application of group theory to molecular systems biology.

    Rietman, Edward A; Karp, Robert L; Tuszynski, Jack A

    2011-06-22

    In this paper we provide a review of selected mathematical ideas that can help us better understand the boundary between living and non-living systems. We focus on group theory and abstract algebra applied to molecular systems biology. Throughout this paper we briefly describe possible open problems. In connection with the genetic code we propose that it may be possible to use perturbation theory to explore the adjacent possibilities in the 64-dimensional space-time manifold of the evolving genome. With regards to algebraic graph theory, there are several minor open problems we discuss. In relation to network dynamics and groupoid formalism we suggest that the network graph might not be the main focus for understanding the phenotype but rather the phase space of the network dynamics. We show a simple case of a C6 network and its phase space network. We envision that the molecular network of a cell is actually a complex network of hypercycles and feedback circuits that could be better represented in a higher-dimensional space. We conjecture that targeting nodes in the molecular network that have key roles in the phase space, as revealed by analysis of the automorphism decomposition, might be a better way to drug discovery and treatment of cancer.

  12. Collision models in quantum optics

    Ciccarello, Francesco

    2017-12-01

    Quantum collision models (CMs) provide advantageous case studies for investigating major issues in open quantum systems theory, and especially quantum non-Markovianity. After reviewing their general definition and distinctive features, we illustrate the emergence of a CM in a familiar quantum optics scenario. This task is carried out by highlighting the close connection between the well-known input-output formalism and CMs. Within this quantum optics framework, usual assumptions in the CMs' literature - such as considering a bath of noninteracting yet initially correlated ancillas - have a clear physical origin.

  13. The binary collision approximation: Background and introduction

    Robinson, M.T.

    1992-08-01

    The binary collision approximation (BCA) has long been used in computer simulations of the interactions of energetic atoms with solid targets, as well as being the basis of most analytical theory in this area. While mainly a high-energy approximation, the BCA retains qualitative significance at low energies and, with proper formulation, gives useful quantitative information as well. Moreover, computer simulations based on the BCA can achieve good statistics in many situations where those based on full classical dynamical models require the most advanced computer hardware or are even impracticable. The foundations of the BCA in classical scattering are reviewed, including methods of evaluating the scattering integrals, interaction potentials, and electron excitation effects. The explicit evaluation of time at significant points on particle trajectories is discussed, as are scheduling algorithms for ordering the collisions in a developing cascade. An approximate treatment of nearly simultaneous collisions is outlined and the searching algorithms used in MARLOWE are presented

  14. The pipe model theory half a century on: a review.

    Lehnebach, Romain; Beyer, Robert; Letort, Véronique; Heuret, Patrick

    2018-01-23

    More than a half century ago, Shinozaki et al. (Shinozaki K, Yoda K, Hozumi K, Kira T. 1964b. A quantitative analysis of plant form - the pipe model theory. II. Further evidence of the theory and its application in forest ecology. Japanese Journal of Ecology14: 133-139) proposed an elegant conceptual framework, the pipe model theory (PMT), to interpret the observed linear relationship between the amount of stem tissue and corresponding supported leaves. The PMT brought a satisfactory answer to two vividly debated problems that were unresolved at the moment of its publication: (1) What determines tree form and which rules drive biomass allocation to the foliar versus stem compartments in plants? (2) How can foliar area or mass in an individual plant, in a stand or at even larger scales be estimated? Since its initial formulation, the PMT has been reinterpreted and used in applications, and has undoubtedly become an important milestone in the mathematical interpretation of plant form and functioning. This article aims to review the PMT by going back to its initial formulation, stating its explicit and implicit properties and discussing them in the light of current biological knowledge and experimental evidence in order to identify the validity and range of applicability of the theory. We also discuss the use of the theory in tree biomechanics and hydraulics as well as in functional-structural plant modelling. Scrutinizing the PMT in the light of modern biological knowledge revealed that most of its properties are not valid as a general rule. The hydraulic framework derived from the PMT has attracted much more attention than its mechanical counterpart and implies that only the conductive portion of a stem cross-section should be proportional to the supported foliage amount rather than the whole of it. The facts that this conductive portion is experimentally difficult to measure and varies with environmental conditions and tree ontogeny might cause the commonly

  15. A review of plasma polarimetry (theory and techniques)

    Segre, S. E.

    1997-11-01

    A review of plasma polarimetry is presented. First the theory is discussed in general, exact analytic solutions of the polarization evolution equation are presented and then approximate analytic solutions. Numerical integration of the evolution equation is also discussed. The design of experiments is then considered, with special attention to the techniques of polarization modulation (both progressive and alternating modulation). Different alternative configurations are described for progressive modulation which are of special interest because they can be realized in the far infrared and because they allow a measurement of phases rather than amplitudes. The effects of refraction are then considered. Finally, the combination of polarimetry and interferometry on the same instrument is discussed, including the effects of polarization modulation

  16. BOOK REVIEW: Path Integrals in Field Theory: An Introduction

    Ryder, Lewis

    2004-06-01

    In the 1960s Feynman was known to particle physicists as one of the people who solved the major problems of quantum electrodynamics, his contribution famously introducing what are now called Feynman diagrams. To other physicists he gained a reputation as the author of the Feynman Lectures on Physics; in addition some people were aware of his work on the path integral formulation of quantum theory, and a very few knew about his work on gravitation and Yang--Mills theories, which made use of path integral methods. Forty years later the scene is rather different. Many of the problems of high energy physics are solved; and the standard model incorporates Feynman's path integral method as a way of proving the renormalisability of the gauge (Yang--Mills) theories involved. Gravitation is proving a much harder nut to crack, but here also questions of renormalisability are couched in path-integral language. What is more, theoretical studies of condensed matter physics now also appeal to this technique for quantisation, so the path integral method is becoming part of the standard apparatus of theoretical physics. Chapters on it appear in a number of recent books, and a few books have appeared devoted to this topic alone; the book under review is a very recent one. Path integral techniques have the advantage of enormous conceptual appeal and the great disadvantage of mathematical complexity, this being partly the result of messy integrals but more fundamentally due to the notions of functional differentiation and integration which are involved in the method. All in all this subject is not such an easy ride. Mosel's book, described as an introduction, is aimed at graduate students and research workers in particle physics. It assumes a background knowledge of quantum mechanics, both non-relativistic and relativistic. After three chapters on the path integral formulation of non-relativistic quantum mechanics there are eight chapters on scalar and spinor field theory, followed

  17. Theory of low-energy electron-molecule collision physics in the coupled-channel method and application to e-CO2 scattering

    Morrison, M.A.

    1976-08-01

    A theory of electron-molecule scattering based on the fixed-nuclei approximation in a body-fixed reference frame is formulated and applied to e-CO 2 collisions in the energy range from 0.07 to 10.0 eV. The procedure used is a single-center coupled-channel method which incorporates a highly accurate static interaction potential, an approximate local exchange potential, and an induced polarization potential. Coupled equations are solved by a modification of the integral equations algorithm; several partial waves are required in the region of space near the nuclei, and a transformation procedure is developed to handle the consequent numerical problems. The potential energy is converged by separating electronic and nuclear contributions in a Legendre-polynomial expansion and including a large number of the latter. Formulas are derived for total elastic, differential, momentum transfer, and rotational excitation cross sections. The Born and asymptotic decoupling approximations are derived and discussed in the context of comparison with the coupled-channel cross sections. Both are found to be unsatisfactory in the energy range under consideration. An extensive discussion of the technical aspects of calculations for electron collisions with highly nonspherical targets is presented, including detailed convergence studies and a discussion of various numerical difficulties. The application to e-CO 2 scattering produces converged results in good agreement with observed cross sections. Various aspects of the physics of this collision are discussed, including the 3.8 eV shape resonance, which is found to possess both p and f character, and the anomalously large low-energy momentum transfer cross sections, which are found to be due to Σ/sub g/ symmetry. Comparison with static and static-exchange approximations are made

  18. Perturbative Gravity and Gauge Theory Relations: A Review

    Thomas Søndergaard

    2012-01-01

    Full Text Available This paper is dedicated to the amazing Kawai-Lewellen-Tye relations, connecting perturbative gravity and gauge theories at tree level. The main focus is on n-point derivations and general properties both from a string theory and pure field theory point of view. In particular, the field theory part is based on some very recent developments.

  19. Review of network research in scientific journal ‘Entrepreneurship Theory and Practice’

    Agnieszka Brzozowska; Michał Zdziarski

    2016-01-01

    This article aims at presenting a systematic review of publications that verified the network theory and the theory of networks empirically, published in the entrepreneurship journal with the highest Impact Factor: “Entrepreneurship Theory and Practice”. We present how publication frequency evolved over time, and classify papers into major streams of entrepreneurship research. Our findings suggest the theory of networks is an under-researched area promising for further advancing the theory of...

  20. Quantum-mechanical theory including angular momenta analysis of atom-atom collisions in a laser field

    Devries, P. L.; George, T. F.

    1978-01-01

    The problem of two atoms colliding in the presence of an intense radiation field, such as that of a laser, is investigated. The radiation field, which couples states of different electronic symmetry, is described by the number state representation while the electronic degrees of freedom (plus spin-orbit interaction) are discussed in terms of a diabatic representation. The total angular momentum of the field-free system and the angular momentum transferred by absorption (or emission) of a photon are explicitly considered in the derivation of the coupled scattering equations. A model calculation is discussed for the Xe + F collision system.

  1. BOOK REVIEW: Kinetic theory of plasma waves, homogeneous plasmas

    Porkolab, Miklos

    1998-11-01

    The linear theory of plasma waves in homogeneous plasma is arguably the most mature and best understood branch of plasma physics. Given the recently revised version of Stix's excellent Waves in Plasmas (1992), one might ask whether another book on this subject is necessary only a few years later. The answer lies in the scope of this volume; it is somewhat more detailed in certain topics than, and complementary in many fusion research relevant areas to, Stix's book. (I am restricting these comments to the homogeneous plasma theory only, since the author promises a second volume on wave propagation in inhomogeneous plasmas.) This book is also much more of a theorist's approach to waves in plasmas, with the aim of developing the subject within the logical framework of kinetic theory. This may indeed be pleasing to the expert and to the specialist, but may be too difficult to the graduate student as an `introduction' to the subject (which the author explicitly states in the Preface). On the other hand, it may be entirely appropriate for a second course on plasma waves, after the student has mastered fluid theory and an introductory kinetic treatment of waves in a hot magnetized `Vlasov' plasma. For teaching purposes, my personal preference is to review the cold plasma wave treatment using the unified Stix formalism and notation (which the author wisely adopts in the present book, but only in Chapter 5). Such an approach allows one to deal with CMA diagrams early on, as well as to provide a framework to discuss electromagnetic wave propagation and accessibility in inhomogeneous plasmas (for which the cold plasma wave treatment is perfectly adequate). Such an approach does lack some of the rigour, however, that the author achieves with the present approach. As the author correctly shows, the fluid theory treatment of waves follows logically from kinetic theory in the cold plasma limit. I only question the pedagogical value of this approach. Otherwise, I welcome this

  2. A review of game theory approach to cyber security risk management

    A review of game theory approach to cyber security risk management. ... This paper presents a review of game theoretic-based model for cyber security risk management. Specifically, issues on ... AJOL African Journals Online. HOW TO USE ...

  3. Despina Hatzifotiadou: ALICE Master Class 3 - Theory: strangeness enhancement; centrality of lead-lead collisions; efficiency, yield, background etc

    CERN. Geneva

    2016-01-01

    This is the 3rd of 4 short online videos. It explains what is: strangeness enhancement; centrality of lead-lead collisions; efficiency, yield, background etc. More details and related links on this indico event page. In more detail: What is Physics Master Classes Students after morning lectures, run programmes in the afternoon to do measurements. These tutorials are about how to use the software required to do these measurements. Background info and examples  Looking for strange particles with ALICE http://aliceinfo.cern.ch/Public/MasterCL/MasterClassWebpage.html Introduction to first part of the exercise : what are strange particles, V0 decays, invariant mass. Demonstration of the software for the 1st part of the exercise - visual identification of V0s Introduction to second part of the exercise : strangeness enhancement; centrality of lead-lead collisions; explanation of efficiency, yield, background etc Demonstration of the software for the 2nd part of the exercise - invariant mass spectr...

  4. Quantum-mechanical theory for electronic-vibrational-rotational energy transfer in atom--diatom collisions: Analysis of the Hamiltonian

    Bellum, J.C.; McGuire, P.

    1983-01-01

    We investigate forms of the molecular system Hamiltonian valid for rigorous quantum-mechanical treatments of inelastic atom--diatom collisions characterized by exchange of energy between electronic, vibrational, and rotational degrees of freedom. We analyze this Hamiltonian in terms of various choices of independent coordinates which unambiguously specify the electronic and nuclear positions in the context of space-fixed and body-fixed reference frames. In particular we derive forms of the Hamiltonian in the context of the following four sets of independent coordinates: (1) a so-called space-fixed set, in which both electronic and nuclear positions are relative to the space-fixed frame; (2) a so-called mixed set, in which nuclear positions are relative to the body-fixed frame while electronic positions are relative to the space-fixed frame; (3) a so-called body-fixed set, in which both electronic and nuclear positions are relative to the body-fixed frame; and (4) another mixed set, in which nuclear positions are relative to the space-fixed frame while electronic positions are relative to the body-fixed frame. Based on practical considerations in accounting for electronic structure and nonadiabatic coupling of electronic states of the collision complex we find the forms of the Hamiltonian in the context of coordinate sets (3) and (4) above to be most appropriate, respectively, for body-fixed and space-fixed treatments of nuclear dynamics in collisional transfer of electronic, vibrational, and rotational energies

  5. Cusp shape studies in H+→He collision in the energy range 75-1400 keV: experiment and theory

    Zavodszky, P.A.; Gulyas, L.; Sarkadi, L.; Vajnai, T.; Szabo, G.; Ricz, S.; Palinkas, J.; Berenyi, D.

    1994-01-01

    The aim of the present study was to measure the double differential cross section (DDCS) for the electron ejection as a function of electron energy at 0 observation angle in H + →He collisions. Having in mind that the experimental and theoretical shape parameters of the DDCS known in the literature are rather scattered, we made a systematic study in the projectile energy range 75-1400 keV. The total electron yield and the shape parameters of the DDCS were determined and compared with the corresponding values from 2nd order OBK, CDW and CDW-EIS theories. A further aim of this work was to check whether the velocity of the projectile and that of the electrons at the maximum of the cusp peak are indeed equal. (orig.)

  6. A Short Review of the Theory of Hard Exclusive Processes

    Wallon, S.

    2012-01-01

    We first present an introduction to the theory of hard exclusive processes. We then illustrate this theory by a few selected examples. The last part is devoted to the most recent developments in the asymptotical energy limit. (author)

  7. Non-parametric Bayesian networks: Improving theory and reviewing applications

    Hanea, Anca; Morales Napoles, Oswaldo; Ababei, Dan

    2015-01-01

    Applications in various domains often lead to high dimensional dependence modelling. A Bayesian network (BN) is a probabilistic graphical model that provides an elegant way of expressing the joint distribution of a large number of interrelated variables. BNs have been successfully used to represent uncertain knowledge in a variety of fields. The majority of applications use discrete BNs, i.e. BNs whose nodes represent discrete variables. Integrating continuous variables in BNs is an area fraught with difficulty. Several methods that handle discrete-continuous BNs have been proposed in the literature. This paper concentrates only on one method called non-parametric BNs (NPBNs). NPBNs were introduced in 2004 and they have been or are currently being used in at least twelve professional applications. This paper provides a short introduction to NPBNs, a couple of theoretical advances, and an overview of applications. The aim of the paper is twofold: one is to present the latest improvements of the theory underlying NPBNs, and the other is to complement the existing overviews of BNs applications with the NPNBs applications. The latter opens the opportunity to discuss some difficulties that applications pose to the theoretical framework and in this way offers some NPBN modelling guidance to practitioners. - Highlights: • The paper gives an overview of the current NPBNs methodology. • We extend the NPBN methodology by relaxing the conditions of one of its fundamental theorems. • We propose improvements of the data mining algorithm for the NPBNs. • We review the professional applications of the NPBNs.

  8. Signatures of quark-gluon plasma formation in high energy heavy-ion collisions: a critical review

    Bass, S.A.; Gyulassy, M.; Stoecker, H.; Greiner, W.

    1999-01-01

    A critical review on signatures of quark-gluon plasma (QGP) formation is given and the current (1998) experimental status is discussed. After giving an introduction to the properties of QCD matter in both, equilibrium and non-equilibrium theories, we focus on observables which may yield experimental evidence for QGP formation. For each individual observable the discussion is divided into three sections: first the connection between the respective observable and QGP formation in terms of the underlying theoretical concepts is given, then the relevant experimental results are reviewed and finally the current status concerning the interpretation of both, theory and experiment, is discussed. A comprehensive summary including an outlook towards RHIC is given in the final section. (author)

  9. Photon-photon collisions

    Burke, D.L.

    1982-10-01

    Studies of photon-photon collisions are reviewed with particular emphasis on new results reported to this conference. These include results on light meson spectroscopy and deep inelastic e#betta# scattering. Considerable work has now been accumulated on resonance production by #betta##betta# collisions. Preliminary high statistics studies of the photon structure function F 2 /sup #betta#/(x,Q 2 ) are given and comments are made on the problems that remain to be solved

  10. Light fragment emission within the model of transport theory for high-energy nucleus-nucleus collisions

    Malfliet, R.; Martschew, E.; Schuermann, B.

    1983-01-01

    The model of transport theory is extended to include the formation of composite particles through thermodynamics. First results obtained are encouraging and show the significance of non-equilibrated components in the inclusive spectra. (author)

  11. Dual-process models of health-related behaviour and cognition: a review of theory.

    Houlihan, S

    2018-03-01

    The aim of this review was to synthesise a spectrum of theories incorporating dual-process models of health-related behaviour. Review of theory, adapted loosely from Cochrane-style systematic review methodology. Inclusion criteria were specified to identify all relevant dual-process models that explain decision-making in the context of decisions made about human health. Data analysis took the form of iterative template analysis (adapted from the conceptual synthesis framework used in other reviews of theory), and in this way theories were synthesised on the basis of shared theoretical constructs and causal pathways. Analysis and synthesis proceeded in turn, instead of moving uni-directionally from analysis of individual theories to synthesis of multiple theories. Namely, the reviewer considered and reconsidered individual theories and theoretical components in generating the narrative synthesis' main findings. Drawing on systematic review methodology, 11 electronic databases were searched for relevant dual-process theories. After de-duplication, 12,198 records remained. Screening of title and abstract led to the exclusion of 12,036 records, after which 162 full-text records were assessed. Of those, 21 records were included in the review. Moving back and forth between analysis of individual theories and the synthesis of theories grouped on the basis of theme or focus yielded additional insights into the orientation of a theory to an individual. Theories could be grouped in part on their treatment of an individual as an irrational actor, as social actor, as actor in a physical environment or as a self-regulated actor. Synthesising identified theories into a general dual-process model of health-related behaviour indicated that such behaviour is the result of both propositional and unconscious reasoning driven by an individual's response to internal cues (such as heuristics, attitude and affect), physical cues (social and physical environmental stimuli) as well as

  12. Explaining the food safety behaviours of food handlers using theories of behaviour change: a systematic review.

    Young, Ian; Thaivalappil, Abhinand; Greig, Judy; Meldrum, Richard; Waddell, Lisa

    2018-06-01

    Theories of behaviour change can explain the factors affecting food handlers' use of food safety practices. A systematic review was conducted on this topic to identify which theories have been applied in this area and to determine which theories are the most consistent predictors of food handlers' behaviours. Standard systematic review procedures were followed: comprehensive search strategy; relevance screening of abstracts; article characterization; data extraction; risk-of-bias assessment; and descriptive analysis. Among 19 relevant studies, the most commonly investigated theories were the Theory of Planned Behaviour (n = 9 studies) and Health Belief Model (n = 5). All investigated theories were useful to explain food handlers' behavioural intentions and behaviours related to food safety across different settings, and could serve as useful frameworks for future research and practice. However, there was wide variability in the predictive ability of the theories and their specific constructs, indicating theories should be adapted to the local context of application.

  13. A Critical Review of Theory in Social Work Journals: A Replication Study

    Carolyn S. Gentle-Genitty

    2007-05-01

    Full Text Available The purpose of this paper is multifold.Key aspects discussed include exploring the extent of theory discussion and progression in social work journals for the year 2004; discussing the necessity of theory in social work research and practice; reviewing previous research literature regarding evaluation of theory discussion and progression; proposing criteria for defining theory in social work journals; and presenting findings from the current study concerning theory discussion and progression in social work journals. Results: Of the 1,168 articles reviewed from 37 journals, 71 (approximately 6% met the criteria for theory development with empirical base. Thus, a minimal number of articles (3 out of 71 or 4.2% evaluated, based on the criteria in the theory quality scale (Table 1, received high quality ratings. Conclusion: Based on the results yielded by the analysis, we assert that social workers need to make a conscious effort to include theory in practice decisions.

  14. Supersymmetrical dual string theories and their field theory limits: A review

    Green, M.B.

    1985-01-01

    This paper outlines the construction and properties of supersymmetric string theories. Such theories, which describe the quantum mechanics of relativistic strings in ten-space time dimensions contain both N=4 Yang-Mills and N=8 supergravity field theories as special limits in which the string tension becomes infinite. Calculations of one-loop S-matrix elements reveal remarkable finiteness properties

  15. A critical review on the scaling theory of dispersion

    Zech, Alraune; Mai, Juliane; Attinger, Sabine; Dietrich, Peter; Teutsch, Georg; Fiori, Aldo; Rubin, Yoram

    2014-05-01

    The phenomenon of dispersive mixing of solutes in aquifers is subject of research since decades. The characterization of dispersivity at a particular field site is a prerequisite to predict the movement and spreading of a contaminant plume. Experimental investigations have shown, that field-scale dispersivities vary over orders of magnitude, which apparently depends on the scale of measurement. Gelhar et al. [1992] and Schulze-Makuch [2005] have reviewed a large number of transport experiments reported in the literature. Based on that data Schulze-Makuch [2005] performed a trend analysis of longitudinal dispersivity, fostering the empirical relationship of a power law between dispersivities and the scale of measurement without an upper bound. The goal of our study is to critically revisit not only the data used for the trend analysis but the power-law scale dependence of longitudinal dispersivity (e.g. Neuman [1990], Xu and Eckstein [1995]). Our particular focus is on the reported dispersivities of large amount (larger than 100m) and large measurement scales (in the order of kilometers). We aim to evaluate current theories of transport against a critical "mass" of field experiments and to bracket the conditions of their applicability. We further aim to evaluate the adequacy of the field sampling techniques that were employed from the perspective of more than 30 years development in modeling and field characterization. Given the tremendous progress in field data acquisition techniques and new insights gained, it is reasonable to expect that interpretations of past experiments may be flawed due to the limitations or inadequacy of field sampling techniques. Gelhar, L.W., C. Welty, and K.R. Rehfeldt, 1992, A critical review of data on field-scale dispersion in aquifers, Water Resources Research 28, No. 7: 1955-1974. Schulze-Makuch, D., 2005, Longitudinal dispersivity data and implications for scaling behavior, Ground Water, Vol. 43, No. 3, 443-456. Neuman, S.P., 1990

  16. Initial state fluctuations and final state correlations in relativistic heavy-ion collisions

    Luzum, Matthew; Petersen, Hannah

    2014-01-01

    We review the phenomenology and theory of bulk observables in ultra-relativistic heavy-ion collisions, focusing on recent developments involving event-by-event fluctuations in the initial stages of a heavy-ion collision, and how they manifest in observed correlations. We first define the relevant observables and show how each measurement is related to underlying theoretical quantities. Then we review the prevailing picture of the various stages of a collision, including the state-of-the-art modeling of the initial stages of a collision and subsequent hydrodynamic evolution, as well as hadronic scattering and freeze-out in the later stages. We then discuss the recent results that have shaped our current understanding and identify the challenges that remain. Finally, we point out open issues and the potential for progress in the field. (topical review)

  17. Psychosomatics today: a review of contemporary theory and practice.

    Gubb, Karen

    2013-02-01

    In the past few years there has been a dramatic increase in the number of psychoanalytic publications on the topic of psychosomatic illness, including edited collections and special editions of psychoanalytic journals. This paper is a critical conceptual review of the topic of psychosomatic illness using the material contained in a number of these recent publications as a basis, but also drawing on other works by the key authors of the publications discussed herein. This paper proposes that currently there appear to be two schools of thought around the origin, development, and treatment of psychosomatic symptoms. The first of these is the well-established "Paris School of Psychosomatics." The second approach does not formally exist, but is referred to in this paper as the "Attachment approach" since there are a number of authors who theorize about the treatment of psychosomatic symptoms in a similar and important way. The paper will compare and contrast the two approaches with respect to their underlying theories, treatment approaches, and conceptualization of the mind-body problem, with particular attention paid to how this is related to mentalization. The understanding of how problems in mentalization may be linked to psychosomatic illness can be conceptualized as the "speechless mind" from the perspective of the Paris School and as the "speaking body" by the Attachment approach. The paper concludes by engaging with these two conceptualizations and suggests that in order for an individual to achieve both psychological and physical health, the work of sensation must be located primarily in the logic and function of the body, while the work of making sense of these sensations and interpreting them must be located in the mind.

  18. The Crisis in Economic Theory: A Review Essay

    Hoover, Kevin D.

    2015-01-01

    The Great Recession and the financial crisis of 2007-09 prompted ca lls for fundamental reforms of economic theory. The role of theory in economics and in recent economic events is considered in light of two recen t books: the sociologist Richard Swedberg's The Art of Social Theory and the economist André Orléan's The Empire of Value: A New Foundation for Economics.

  19. Avian mortalities due to transmission line collisions: a review of current estimates and field methods with an emphasis on applications to the Canadian electric network

    Sébastien Rioux

    2013-12-01

    Full Text Available Birds are vulnerable to collisions with human-made fixed structures. Despite ongoing development and increases in infrastructure, we have few estimates of the magnitude of collision mortality. We reviewed the existing literature on avian mortality associated with transmission lines and derived an initial estimate for Canada. Estimating mortality from collisions with power lines is challenging due to the lack of studies, especially from sites within Canada, and due to uncertainty about the magnitude of detection biases. Detection of bird collisions with transmission lines varies due to habitat type, species size, and scavenging rates. In addition, birds can be crippled by the impact and subsequently die, although crippling rates are poorly known and rarely incorporated into estimates. We used existing data to derive a range of estimates of avian mortality associated with collisions with transmission lines in Canada by incorporating detection, scavenging, and crippling biases. There are 231,966 km of transmission lines across Canada, mostly in the boreal forest. Mortality estimates ranged from 1 million to 229.5 million birds per year, depending on the bias corrections applied. We consider our most realistic estimate, taking into account variation in risk across Canada, to range from 2.5 million to 25.6 million birds killed per year. Data from multiple studies across Canada and the northern U.S. indicate that the most vulnerable bird groups are (1 waterfowl, (2 grebes, (3 shorebirds, and (4 cranes, which is consistent with other studies. Populations of several groups that are vulnerable to collisions are increasing across Canada (e.g., waterfowl, raptors, which suggests that collision mortality, at current levels, is not limiting population growth. However, there may be impacts on other declining species, such as shorebirds and some species at risk, including Alberta's Trumpeter Swans (Cygnus buccinator and western Canada's endangered Whooping

  20. Review of "Foundations of Social Theory," by James S. Coleman.

    Gibbs, Jack P.

    1990-01-01

    Suggests that this book is a major contribution to sociology and that its greatest (and most controversial) merit is its insistence that sociological macrovariables must be demonstrably related through individual action having purposive quality. Discusses modes of theory construction, rational choice theory, and reductionism. (SV)

  1. Out of our minds: a review of sociocultural cognition theory

    Tenenberg, Josh; Knobelsdorf, Maria

    2014-01-01

    Theories of mind are implicitly embedded in educational research. The predominant theory of mind during the latter half of the twentieth century has focused primarily on the individual mind in isolation, context-free problem-solving and mental representations and reasoning, what we refer to as cognitivism. Over the last two decades, CS Education researchers have begun to incorporate recent research that extends, elaborates and sometimes challenges cognitivism. These theories, which we refer to collectively as sociocultural cognition theory, view minds as cultural products, biologically evolved to be extended by tools, social interaction and embodied interaction in the world. Learning, under this perspective, is viewed as tool-mediated participation in the ongoing practices of cultural communities. In this paper, we pursue three goals. First, we provide a summary of the key principles in sociocultural cognition theory, placing this theory within a historical context with respect to the cognitive theories that it extends and challenges. Second, we integrate across different but related research efforts that all fall under the sociocultural cognition umbrella, using a uniform terminology for describing ideas represented within different discourse communities. And third, we reference a number of canonical sources in sociocultural cognition theory so as to serve as an index into this diverse literature for those wanting to explore further.

  2. Out of Our Minds: A Review of Sociocultural Cognition Theory

    Tenenberg, Josh; Knobelsdorf, Maria

    2014-01-01

    Theories of mind are implicitly embedded in educational research. The predominant theory of mind during the latter half of the twentieth century has focused primarily on the individual mind in isolation, context-free problem-solving and mental representations and reasoning, what we refer to as "cognitivism." Over the last two decades, CS…

  3. Review of high excitation energy structures in heavy ion collisions: target excitations and three body processes

    Frascaria, N.

    1987-09-01

    A review of experimental results on high excitation energy structures in heavy ion inelastic scattering is presented. The contribution to the spectra of the pick-up break-up mechanism is discussed in the light of the data obtained with light heavy ion projectiles. Recent results obtained with 40 Ar beams at various energies will show that target excitations contribute strongly to the measured cross section

  4. Progress in the axiomatic quantum field theory. [Review

    Vladimirov, V S; Polivanov, M K

    1975-01-01

    The authors consider the development of mathematical methods of solving quantum field theory problems from attempts of simple perfection of usual methods of quantum mechanics by elaborating the methods of perturbation theory and S-matrix, by working out the perturbation theory for quantum electrodynamics, and by applying dispersion relations and S-matrix for strong interactions. The method of dispersion relations results in the majority of radically new ways of describing the scattering amplitude. The grave disadvantage of all the methods is that they little define the dynamics of processes. The dynamic theory in the Heisenberg representation may be constructed on the basis of the axiomatic theory of S-matrix with the casuality condition. Another axiomatic direction has been recently developed; that is the so-called algebraic axiomatics which makes use of methods of Csup(*)-algebras.

  5. Ultrarelativistic atomic collisions

    Bottcher, C.; Strayer, M.R.

    1991-01-01

    Calculations of the coherent production of free pairs and of pair production with electron capture from ultrarelativistic ion-ion collisions are discussed. Theory and experiment are contrasted, with some conjectures on the possibility of new phenomena. 29 refs., 5 figs., 1 tab

  6. Electron capture in ion-molecule collisions at intermediate energy

    Kumura, M.

    1986-01-01

    Recent progress of theoretical charge transfer study in ion-molecule collisions at the intermediate energy is reviewed. Concept of close and distant collisions obtained from extensive ion-atom collision studies is identified so that it can be utilized to model two distinct collision processes. For a close collision, explicit representation of the whole collision complex is necessary to describe collision dynamics correctly, while a model potential approach for molecule is appropriate for a distant collision. It is shown that these two distinct models are indeed capable of reproducing experimental charge transfer cross sections. Some remarks for further theoretical study of ion-molecule collisions are also given. 21 refs., 8 figs

  7. Effects of beam-beam collisions on storage-ring performance - a pedagogical review

    Schonfeld, J.F.

    1983-01-01

    This paper presents a survey of the experimental and theoretical literature on colliding-beam effects in both leptonic and hadronic storage rings. For the most part, this literature is rather technical and, to the novice, both obscurely written and hard to locate. Although there have already been several symposia on the subject, as well as a number of reviews for specialists there has up till now been no unified and pedagogical exposition. The present work represents an attempt to fill this gap. The material is grouped into four major areas: observational phenomenology, computer simulation, mathematical background, and theoretical models. 113 references, 36 figures

  8. Primary damage in tungsten using the binary collision approximation, molecular dynamic simulations and the density functional theory

    De Backer, A; Sand, A; Ortiz, C J; Domain, C; Olsson, P; Berthod, E; Becquart, C S

    2016-01-01

    The damage produced by primary knock-on atoms (PKA) in W has been investigated from the threshold displacement energy (TDE) where it produces one self interstitial atom–vacancy pair to larger energies, up to 100 keV, where a large molten volume is formed. The TDE has been determined in different crystal directions using the Born–Oppenheimer density functional molecular dynamics (DFT-MD). A significant difference has been observed without and with the semi-core electrons. Classical MD has been used with two different empirical potentials characterized as ‘soft’ and ‘hard’ to obtain statistics on TDEs. Cascades of larger energy have been calculated, with these potentials, using a model that accounts for electronic losses (Sand et al 2013 Europhys. Lett. 103 46003). Two other sets of cascades have been produced using the binary collision approximation (BCA): a Monte Carlo BCA using SDTrimSP (Eckstein et al 2011 SDTrimSP: Version 5.00. Report IPP 12/8) (similar to SRIM www.srim.org) and MARLOWE (RSICC Home Page. (https://rsicc.ornl.gov/codes/psr/psr1/psr-137.html) (accessed May, 2014)). The comparison of these sets of cascades gave a recombination distance equal to 12 Å which is significantly larger from the one we reported in Hou et al (2010 J. Nucl. Mater. 403 89) because, here, we used bulk cascades rather than surface cascades which produce more defects (Stoller 2002 J. Nucl. Mater. 307 935, Nordlund et al 1999 Nature 398 49). Investigations on the defect clustering aspect showed that the difference between BCA and MD cascades is considerably reduced after the annealing of the cascade debris at 473 K using our Object Kinetic Monte Carlo model, LAKIMOCA (Domain et al 2004 J. Nucl. Mater. 335 121). (paper)

  9. Collision partner selection schemes in DSMC: From micro/nano flows to hypersonic flows

    Roohi, Ehsan, E-mail: e.roohi@ferdowsi.um.ac.ir; Stefanov, Stefan

    2016-10-25

    The motivation of this review paper is to present a detailed summary of different collision models developed in the framework of the direct simulation Monte Carlo (DSMC) method. The emphasis is put on a newly developed collision model, i.e., the Simplified Bernoulli trial (SBT), which permits efficient low-memory simulation of rarefied gas flows. The paper starts with a brief review of the governing equations of the rarefied gas dynamics including Boltzmann and Kac master equations and reiterates that the linear Kac equation reduces to a non-linear Boltzmann equation under the assumption of molecular chaos. An introduction to the DSMC method is provided, and principles of collision algorithms in the DSMC are discussed. A distinction is made between those collision models that are based on classical kinetic theory (time counter, no time counter (NTC), and nearest neighbor (NN)) and the other class that could be derived mathematically from the Kac master equation (pseudo-Poisson process, ballot box, majorant frequency, null collision, Bernoulli trials scheme and its variants). To provide a deeper insight, the derivation of both collision models, either from the principles of the kinetic theory or the Kac master equation, is provided with sufficient details. Some discussions on the importance of subcells in the DSMC collision procedure are also provided and different types of subcells are presented. The paper then focuses on the simplified version of the Bernoulli trials algorithm (SBT) and presents a detailed summary of validation of the SBT family collision schemes (SBT on transient adaptive subcells: SBT-TAS, and intelligent SBT: ISBT) in a broad spectrum of rarefied gas-flow test cases, ranging from low speed, internal micro and nano flows to external hypersonic flow, emphasizing first the accuracy of these new collision models and second, demonstrating that the SBT family scheme, if compared to other conventional and recent collision models, requires smaller

  10. Collision partner selection schemes in DSMC: From micro/nano flows to hypersonic flows

    Roohi, Ehsan; Stefanov, Stefan

    2016-01-01

    The motivation of this review paper is to present a detailed summary of different collision models developed in the framework of the direct simulation Monte Carlo (DSMC) method. The emphasis is put on a newly developed collision model, i.e., the Simplified Bernoulli trial (SBT), which permits efficient low-memory simulation of rarefied gas flows. The paper starts with a brief review of the governing equations of the rarefied gas dynamics including Boltzmann and Kac master equations and reiterates that the linear Kac equation reduces to a non-linear Boltzmann equation under the assumption of molecular chaos. An introduction to the DSMC method is provided, and principles of collision algorithms in the DSMC are discussed. A distinction is made between those collision models that are based on classical kinetic theory (time counter, no time counter (NTC), and nearest neighbor (NN)) and the other class that could be derived mathematically from the Kac master equation (pseudo-Poisson process, ballot box, majorant frequency, null collision, Bernoulli trials scheme and its variants). To provide a deeper insight, the derivation of both collision models, either from the principles of the kinetic theory or the Kac master equation, is provided with sufficient details. Some discussions on the importance of subcells in the DSMC collision procedure are also provided and different types of subcells are presented. The paper then focuses on the simplified version of the Bernoulli trials algorithm (SBT) and presents a detailed summary of validation of the SBT family collision schemes (SBT on transient adaptive subcells: SBT-TAS, and intelligent SBT: ISBT) in a broad spectrum of rarefied gas-flow test cases, ranging from low speed, internal micro and nano flows to external hypersonic flow, emphasizing first the accuracy of these new collision models and second, demonstrating that the SBT family scheme, if compared to other conventional and recent collision models, requires smaller

  11. Localization and diagonalization. A review of functional integral techniques for low-dimensional gauge theories and topological field theories

    Blau, M.; Thompson, G.

    1995-01-01

    We review localization techniques for functional integrals which have recently been used to perform calculations in and gain insight into the structure of certain topological field theories and low-dimensional gauge theories. These are the functional integral counterparts of the Mathai-Quillen formalism, the Duistermaat-Heckman theorem, and the Weyl integral formula respectively. In each case, we first introduce the necessary mathematical background (Euler classes of vector bundles, equivariant cohomology, topology of Lie groups), and describe the finite dimensional integration formulae. We then discuss some applications to path integrals and give an overview of the relevant literature. The applications we deal with include supersymmetric quantum mechanics, cohomological field theories, phase space path integrals, and two-dimensional Yang-Mills theory. (author). 83 refs

  12. The Organizational Approach of Capability Theory: A Review Essay

    Garzarelli, Giampaolo

    2006-01-01

    Richard Langlois, Tony Yu & Paul Robertson have assembled a collection of previously published papers that move beyond textbook production theory. This essay discusses work by Frank Knight and Hendrik Houthakker not reproduced in LYR in relation to the capability theory of economic organization. Knight identified the problem of organization as the search for and the coordination of different dispersed capabilities. Houthakker helps us to see more clearly that the benefits of specialization ar...

  13. Review of Industrial Applications of Structural Reliability Theory

    Thoft-Christensen, Palle

    For the last two decades we have seen an increasing interest in applying structural reliability theory to many different industries. However, the number of real practical applications is much smaller than what one would expect.......For the last two decades we have seen an increasing interest in applying structural reliability theory to many different industries. However, the number of real practical applications is much smaller than what one would expect....

  14. Life Span and Resiliency Theory: A Critical Review

    Alexa Smith-Osborne

    2007-05-01

    Full Text Available Theories of life span development describe human growth and change over the life cycle (Robbins, Chatterjee, & Canda, 2006. Major types of developmental theories include biological, psychodynamic, behavioral, and social learning, cognitive, moral, and spiritual, and those influenced by systems, empowerment, and conflict theory. Life span development theories commonly focus on ontogenesis and sequential mastery of skills, tasks, and abilities. Social work scholars have pointed out that a limitation of life span and other developmental theory is lack of attention to resilience (Greene, 2007; Robbins et al., 1998. The concept of resilience was developed to “describe relative resistance to psychosocial risk experiences” (Rutter, 1999b, p. 119. Longitudinal studies focused on typical and atypical child development informed theory formulation in developmental psychopathology (Garmezy & Rutter, 1983; Luthar, Cichetti,& Becker, 2000 and in an evolving resilience model (Richardson, 2002; Werner & Smith, 1992. Research on resilience has found a positive relationship between a number of individual traits and contextual variables and resistance to a variety of risk factors among children and adolescents. More recently, resilience research has examined the operation of these same factors in the young adult, middle-age, and elder life stages. This article examines the historical and conceptual progression of the two developmental theories—life span and resiliency—and discusses their application to social work practice and education in human behavior in the social environment.

  15. Literature search strategies for conducting knowledge-building and theory-generating qualitative systematic reviews.

    Finfgeld-Connett, Deborah; Johnson, E Diane

    2013-01-01

    To report literature search strategies for the purpose of conducting knowledge-building and theory-generating qualitative systematic reviews. Qualitative systematic reviews lie on a continuum from knowledge-building and theory-generating to aggregating and summarizing. Different types of literature searches are needed to optimally support these dissimilar reviews. Articles published between 1989-Autumn 2011. These documents were identified using a hermeneutic approach and multiple literature search strategies. Redundancy is not the sole measure of validity when conducting knowledge-building and theory-generating systematic reviews. When conducting these types of reviews, literature searches should be consistent with the goal of fully explicating concepts and the interrelationships among them. To accomplish this objective, a 'berry picking' approach is recommended along with strategies for overcoming barriers to finding qualitative research reports. To enhance integrity of knowledge-building and theory-generating systematic reviews, reviewers are urged to make literature search processes as transparent as possible, despite their complexity. This includes fully explaining and rationalizing what databases were used and how they were searched. It also means describing how literature tracking was conducted and grey literature was searched. In the end, the decision to cease searching also needs to be fully explained and rationalized. Predetermined linear search strategies are unlikely to generate search results that are adequate for purposes of conducting knowledge-building and theory-generating qualitative systematic reviews. Instead, it is recommended that iterative search strategies take shape as reviews evolve. © 2012 Blackwell Publishing Ltd.

  16. Review of the theory of infinite nuclear matter

    Llano, M. de; Tolmachev, V.V.

    1975-01-01

    Given a two-body force, there seems to be two distinct starting points in the many-body perturbation-theoretic problem of computing the energy per nucleon of infinite (as well as finite) nuclear matter: ordinary Hartree-Fock theory and the Brueckner theory. The former theory, treated almost exclusively with plane-wave solutions, has long-ago fallen into disuse, to yield to the latter, apparently more sophisticated, theory. After a brief outline of many-fermion diagramatic techniques, the Brueckner-Bethe-Goldstone series expansion in terms of the density is discussed as a low density, non-ideal Fermi gas theory, whose convergence is analyzed. A calculation based on particle-hole Green's function techniques shows that a nucleon gas condenses to the liquid phase at about 3% of the empirical nuclear matter saturation density. The analogy between the BBG expansion and the virial expansion for a classical or quantum gas is studied with special emphasis on the apparent impossibility of analytical-continuing the latter gas theory to densities in the liquid regime, as first elucidated by Lee and Yang. It is finally argued that ordinary HF theory may provide a good starting point for the eventual understanding of nuclear matter as it gives (in the finite nuclear problem, at any rate) not only the basic liquid properties of a definite density and a surface but also provides independent-particle aspects, avoiding at the same time the idea of n-body clusters appropriate only for dilute gases. This program has to date not been carried out for infinite nuclear matter, mainly because of insufficient knowledge regarding low-energy, non-plane-wave solutions of the HF equations, in the thermodynamic limit [pt

  17. A review of the theories of non-critical strings and random surfaces

    Ambjoern, J.

    1988-11-01

    I review the basic properties of the theory of random surfaces. It is shown that the theory gives a correct description of strings in dimensions d≤1 and of matter fields with central charge c≤1. In this region it coincides with the new results of Knizhnik, Polyakov and Zamolodchikov. Analytical and numerical results for the discretized model and for the standard continuum string model for d>1 indicate a trivial theory in this region. (orig.)

  18. Combining density functional theory (DFT) and collision cross-section (CCS) calculations to analyze the gas-phase behaviour of small molecules and their protonation site isomers.

    Boschmans, Jasper; Jacobs, Sam; Williams, Jonathan P; Palmer, Martin; Richardson, Keith; Giles, Kevin; Lapthorn, Cris; Herrebout, Wouter A; Lemière, Filip; Sobott, Frank

    2016-06-20

    Electrospray ion mobility-mass spectrometry (IM-MS) data show that for some small molecules, two (or even more) ions with identical sum formula and mass, but distinct drift times are observed. In spite of showing their own unique and characteristic fragmentation spectra in MS/MS, no configurational or constitutional isomers are found to be present in solution. Instead the observation and separation of such ions appears to be inherent to their gas-phase behaviour during ion mobility experiments. The origin of multiple drift times is thought to be the result of protonation site isomers ('protomers'). Although some important properties of protomers have been highlighted by other studies, correlating the experimental collision cross-sections (CCSs) with calculated values has proven to be a major difficulty. As a model, this study uses the pharmaceutical compound melphalan and a number of related molecules with alternative (gas-phase) protonation sites. Our study combines density functional theory (DFT) calculations with modified MobCal methods (e.g. nitrogen-based Trajectory Method algorithm) for the calculation of theoretical CCS values. Calculated structures can be linked to experimentally observed signals, and a strong correlation is found between the difference of the calculated dipole moments of the protomer pairs and their experimental CCS separation.

  19. Predicting actual weight loss: A review of the determinants according to the theory of planned behaviour

    Chung, Louisa Ming Yan; Fong, Shirley Siu Ming

    2015-01-01

    Weight reduction that corresponds with lifestyle modification is difficult to foster. The theory of planned behaviour has been actively cited in explaining health-related behaviour. This review evaluated the application of the theory of planned behaviour to weight-loss behaviour. Among the three reviewed papers, cross-sectional survey designs and subjective outcome measurements were commonly applied. All of the studies recruited obese female adults as participants, limiting the generalisabili...

  20. Kolb's Experiential Learning Theory in Athletic Training Education: A Literature Review

    Schellhase, Kristen C.

    2008-01-01

    Objective: Kolb's Experiential Learning Theory offers insight into the development of learning styles, classification of learning styles, and how students learn through experience. Discussion is presented on the value of Kolb's Experiential Learning Theory for Athletic Training Education. Data Sources: This article reviews research related to…

  1. Obesity Intervention Programs among Adolescents Using Social Cognitive Theory: A Systematic Literature Review

    Bagherniya, Mohammad; Taghipour, Ali; Sharma, Manoj; Sahebkar, Amirhossein; Contento, Isobel R.; Keshavarz, Seyed Ali; Mostafavi Darani, Firoozeh; Safarian, Mohammad

    2018-01-01

    Social cognitive theory (SCT) is a well-known theory for designing nutrition education and physical activity programs for adolescents. This systematic review aimed to evaluate the efficacy of intervention studies based on SCT in reducing or preventing overweight and obesity in adolescents. An electronic literature search in PubMed-Medline, Web of…

  2. Identifying Barriers in Implementing Outcomes-Based Assessment Program Review: A Grounded Theory Analysis

    Bresciani, Marilee J.

    2011-01-01

    The purpose of this grounded theory study was to identify the typical barriers encountered by faculty and administrators when implementing outcomes-based assessment program review. An analysis of interviews with faculty and administrators at nine institutions revealed a theory that faculty and administrators' promotion, tenure (if applicable),…

  3. A Historical Review of Counseling Theory Development in Relation to Definitions of Free Will and Determinism.

    Wilks, Duffy

    2003-01-01

    This review traces the development of counseling theory in relation to the philosophical constructs of free will and determinism. Problems associated with free will are discussed, and an analysis of related theoretical trends and convergent paradigms is provided. Results indicate that no major theory of counseling addresses the free will versus…

  4. Ethical Decision Making in Academic Dishonesty with Application of Modified Theory of Planned Behavior: A Review

    Meng, Chan Ling; Othman, Jamilah; D'Silva, Jeffrey Lawrence; Omar, Zoharah

    2014-01-01

    This conceptual paper studies the application of the Theory of Planned Behavior (TBP) in academic dishonesty with the mediating variable of ethical ideologies. The study reviews literature on the Theory of Planned Behavior and past studies pertaining to academic dishonesty. The paper analyses the relationship of the variables of TPB on academic…

  5. Mind-Sets Matter: A Meta-Analytic Review of Implicit Theories and Self-Regulation

    Burnette, Jeni L.; O'Boyle, Ernest H.; VanEpps, Eric M.; Pollack, Jeffrey M.; Finkel, Eli J.

    2013-01-01

    This review builds on self-control theory (Carver & Scheier, 1998) to develop a theoretical framework for investigating associations of implicit theories with self-regulation. This framework conceptualizes self-regulation in terms of 3 crucial processes: goal setting, goal operating, and goal monitoring. In this meta-analysis, we included…

  6. Article Review: Advanced Change Theory Revisited: An Article Critique

    R. Scott Pochron

    2008-12-01

    Full Text Available The complexity of life in 21st century society requires new models for leadingand managing change. With that in mind, this paper revisits the model for AdvancedChange Theory (ACT as presented by Quinn, Spreitzer, and Brown in their article,“Changing Others Through Changing Ourselves: The Transformation of HumanSystems” (2000. The authors present ACT as a potential model for facilitating change incomplex organizations. This paper presents a critique of the article and summarizesopportunities for further exploring the model in the light of current trends indevelopmental and integral theory.

  7. Literary study and evolutionary theory : A review essay.

    Carroll, J

    1998-09-01

    Several recent books have claimed to integrate literary study with evolutionary biology. All of the books here considered, except Robert Storey's, adopt conceptions of evolutionary theory that are in some way marginal to the Darwinian adaptationist program. All the works attempt to connect evolutionary study with various other disciplines or methodologies: for example, with cultural anthropology, cognitive psychology, the psychology of emotion, neurobiology, chaos theory, or structuralist linguistics. No empirical paradigm has yet been established for this field, but important steps have been taken, especially by Storey, in formulating basic principles, identifying appropriate disciplinary connections, and marking out lines of inquiry. Reciprocal efforts are needed from biologists and social scientists.

  8. Collision Mechanics

    Pedersen, Preben Terndrup; Servis, D.P.; Zhang, Shengming

    1999-01-01

    The first section of the present report describes the procedures that are being programmed at DTU for evaluation of the external collision dynamics. Then follows a detailed description of a comprehensive finite element analysis of one collision scenario for MS Dextra carried out at NTUA. The last...

  9. Becoming who you are: An integrative review of self-determination theory and personality systems interactions theory.

    Koole, Sander L; Schlinkert, Caroline; Maldei, Tobias; Baumann, Nicola

    2018-03-10

    One of the enduring missions of personality science is to unravel what it takes to become a fully functioning person. In the present article, the authors address this matter from the perspectives of self-determination theory (SDT) and personality systems interactions (PSI) theory. SDT (a) is rooted in humanistic psychology; (b) has emphasized a first-person perspective on motivation and personality; (c) posits that the person, supported by the social environment, naturally moves toward growth through the satisfaction of basic psychological needs for autonomy, competence, and relatedness. PSI theory (a) is rooted in German volition psychology; (b) has emphasized a third-person perspective on motivation and personality; and (c) posits that a fully functioning person can form and enact difficult intentions and integrate new experiences, and that such competencies are facilitated by affect regulation. The authors review empirical support for SDT and PSI theory, their convergences and divergences, and how the theories bear on recent empirical research on internalization, vitality, and achievement flow. The authors conclude that SDT and PSI theory offer complementary insights into developing a person's full potential. © 2018 The Authors. Journal of Personality Published by Wiley Periodicals, Inc.

  10. A Critical Review of Prominent Theories of Politeness

    Al-Duleimi, Hutheifa Y.; Rashid, Sabariah Md.; Abdullah, Ain Nadzimah

    2016-01-01

    Politeness plays a crucial role in all cultures and societies for maintaining relationships and for face saving. Although politeness is common to all cultures and languages, how it functions and is realised varies from one culture to another. Different theories have been proposed to examine the strategies with which politeness is expressed. Each…

  11. Review of the particle scattering theory in rocket technique application

    Wang Fuheng; Ma Fang

    1990-01-01

    Three calculation methods of scattering cross section have been discussed. Particle scattering theory and its concrete calculation, existing problems and further development have been also studied. The developement of theoretical aspects of particles scattering in rocket exhaust plume was concerned in this paper

  12. Primate theory of mind: a state of the art review

    Byrnit, Jill

    2006-01-01

    -cognitive evner og siden Premack & Woodruff (1978) for første gang introducerede begrebet "theory of mind", er der blevet foretaget mange laboratorie-forsøg om mennesker og andre primaters evne til at attribuere mentale tilstande til andre. I nærværende artikel er størstedelen af disse forsøg med andre primater...

  13. Introduction of the transtheoretical model and organisational development theory in weight management: A narrative review.

    Wu, Ya-Ke; Chu, Nain-Feng

    2015-01-01

    Overweight and obesity are serious public health and medical problems among children and adults worldwide. Behavioural change has been demonstrably contributory to weight management programs. Behavioural change-based weight loss programs require a theoretical framework. We will review the transtheoretical model and the organisational development theory in weight management. The transtheoretical model is a behaviour theory of individual level frequently used for weight management programs. The organisational development theory is a more complicated behaviour theory that applies to behavioural change on the system level. Both of these two theories have their respective strengths and weaknesses. In this manuscript, we try to introduce the transtheoretical model and the organisational development theory in the context of weight loss programs among population that are overweight or obese. Ultimately, we wish to present a new framework/strategy of weight management by integrating these two theories together. Copyright © 2015 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  14. Electronic excitations in fast ion-solid collisions

    Burgdoerfer, J.

    1990-01-01

    We review recent developments in the study of electronic excitation of projectiles in fast ion-solid collisions. Our focus will be primarily on theory but experimental advances will also be discussed. Topics include the evidence for velocity-dependent thresholds for the existence of bound states, wake-field effects on excited states, the electronic excitation of channeled projectiles, transport phenomena, and the interaction of highly charged ions with surfaces. 44 refs., 14 figs

  15. Resonant inelastic collisions of electrons with diatomic molecules

    Houfek, Karel

    2012-01-01

    In this contribution we give a review of applications of the nonlocal resonance theory which has been successfully used for treating the nuclear dynamics of low-energy electron collisions with diatomic molecules over several decades. We give examples and brief explanations of various structures observed in the cross sections of vibrational excitation and dissociative electron attachment to diatomic molecules such as threshold peaks, boomerang oscillations below the dissociative attachment threshold, or outer-well resonances.

  16. Resonant inelastic collisions of electrons with diatomic molecules

    Houfek, Karel, E-mail: karel.houfek@gmail.com [Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, 180 00 Prague 8 (Czech Republic)

    2012-05-15

    In this contribution we give a review of applications of the nonlocal resonance theory which has been successfully used for treating the nuclear dynamics of low-energy electron collisions with diatomic molecules over several decades. We give examples and brief explanations of various structures observed in the cross sections of vibrational excitation and dissociative electron attachment to diatomic molecules such as threshold peaks, boomerang oscillations below the dissociative attachment threshold, or outer-well resonances.

  17. High energy nuclear collisions

    We review some basic concepts of relativistic heavy-ion physics and discuss our understanding of some key results from the experimental program at the relativistic heavy-ion collider (RHIC). We focus in particular on the early time dynamics of nuclear collisions, some result from lattice QCD, hard probes and photons.

  18. Dynamical theory of neutron diffraction. [One-body Schroedinger equation, review

    Sears, V F [Atomic Energy of Canada Ltd., Chalk River, Ontario. Chalk River Nuclear Labs.

    1978-10-01

    We present a review of the dynamical theory of neutron diffraction by macroscopic bodies which provides the theoretical basis for the study of neutron optics. We consider both the theory of dispersion, in which it is shown that the coherent wave in the medium satisfies a macroscopic one-body Schroedinger equation, and the theory of reflection, refraction, and diffraction in which the above equation is solved for a number of special cases of interest. The theory is illustrated with the help of experimental results obtained over the past 10 years by a number of new techniques such as neutron gravity refractometry. Pendelloesung interference, and neutron interferometry.

  19. Social Comparison Theory and the Evaluation of Peer Evaluations: A Review and Some Applied Implications.

    Mumford, Michael D.

    1983-01-01

    Reviewed characteristics of peer evaluations and notes their striking industrial validity. A review of the conditions under which peer evaluations yield strong validity coefficients as well as certain factor analytic and experimental studies indicated that social comparison theory might be useful for elucidating the nature of peer evaluation…

  20. Models and theories in studies on educating and counseling children about physical health: a systematic review.

    Theunissen, N.C.M.; Tates, K.

    2004-01-01

    The aim of this review is to gain a comprehensive view on the theories and models referred to in studies on educating and counseling children about physical health. A computer search was conducted using PubMed Medline, and Silverplatter Webspirs Psycinfo. Original studies, reviews, and theoretical

  1. Transport in nanofluidic systems: a review of theory and applications

    Sparreboom, W; Van den Berg, A; Eijkel, J C T

    2010-01-01

    In this paper transport through nanochannels is assessed, both of liquids and of dissolved molecules or ions. First, we review principles of transport at the nanoscale, which will involve the identification of important length scales where transitions in behavior occur. We also present several important consequences that a high surface-to-volume ratio has for transport. We review liquid slip, chemical equilibria between solution and wall molecules, molecular adsorption to the channel walls and wall surface roughness. We also identify recent developments and trends in the field of nanofluidics, mention key differences with microfluidic transport and review applications. Novel opportunities are emphasized, made possible by the unique behavior of liquids at the nanoscale.

  2. Learning theories and tools for the assessment of core nursing competencies in simulation: A theoretical review.

    Lavoie, Patrick; Michaud, Cécile; Bélisle, Marilou; Boyer, Louise; Gosselin, Émilie; Grondin, Myrian; Larue, Caroline; Lavoie, Stéphan; Pepin, Jacinthe

    2018-02-01

    To identify the theories used to explain learning in simulation and to examine how these theories guided the assessment of learning outcomes related to core competencies in undergraduate nursing students. Nurse educators face the challenge of making explicit the outcomes of competency-based education, especially when competencies are conceptualized as holistic and context dependent. Theoretical review. Research papers (N = 182) published between 1999-2015 describing simulation in nursing education. Two members of the research team extracted data from the papers, including theories used to explain how simulation could engender learning and tools used to assess simulation outcomes. Contingency tables were created to examine the associations between theories, outcomes and tools. Some papers (N = 79) did not provide an explicit theory. The 103 remaining papers identified one or more learning or teaching theories; the most frequent were the National League for Nursing/Jeffries Simulation Framework, Kolb's theory of experiential learning and Bandura's social cognitive theory and concept of self-efficacy. Students' perceptions of simulation, knowledge and self-confidence were the most frequently assessed, mainly via scales designed for the study where they were used. Core competencies were mostly assessed with an observational approach. This review highlighted the fact that few studies examined the use of simulation in nursing education through learning theories and via assessment of core competencies. It also identified observational tools used to assess competencies in action, as holistic and context-dependent constructs. © 2017 John Wiley & Sons Ltd.

  3. Spinning Dust Radiation: A Review of the Theory

    Yacine Ali-Haïmoud

    2013-01-01

    Full Text Available This paper reviews the current status of theoretical modeling of electric dipole radiation from spinning dust grains. The fundamentally simple problem of dust grain rotation appeals to a rich set of concepts of classical and quantum physics, owing to the diversity of processes involved. Rotational excitation and damping rates through various mechanisms are discussed, as well as methods of computing the grain angular momentum distribution function. Assumptions on grain properties are reviewed. The robustness of theoretical predictions now seems mostly limited by the uncertainties regarding the grains themselves, namely, their abundance, dipole moments, and size and shape distribution.

  4. Theory of constraints: A state-of-art review

    Maryam Orouji

    2015-11-01

    Full Text Available The theory of constraints (TOC is a management tool, which considers any manageable system as being limited in reaching more of its objectives by some constraints. According to TOC, there is always, at least, one single constraint, and TOC implements a concentrating process to detect the constraint and restructure the remaining of the organization around it. This paper presents an overview of different perspectives of TOC and its implementation in different industries such as project management, quality management, outsourcing, product mix, make-to-buy, accounting, banking and health care, etc. The results indicate that the method has been extensively implemented in different areas of accounting.

  5. Review. The incentive sensitization theory of addiction: some current issues.

    Robinson, Terry E; Berridge, Kent C

    2008-10-12

    We present a brief overview of the incentive sensitization theory of addiction. This posits that addiction is caused primarily by drug-induced sensitization in the brain mesocorticolimbic systems that attribute incentive salience to reward-associated stimuli. If rendered hypersensitive, these systems cause pathological incentive motivation ('wanting') for drugs. We address some current questions including: what is the role of learning in incentive sensitization and addiction? Does incentive sensitization occur in human addicts? Is the development of addiction-like behaviour in animals associated with sensitization? What is the best way to model addiction symptoms using animal models? And, finally, what are the roles of affective pleasure or withdrawal in addiction?

  6. Funding Us Higher Education: Policy Making Theories Reviewed

    Cooley, Asya

    2015-01-01

    Higher education policy and politics in the United States (US) has been an issue of studies for several decades. Since the 1960s, researchers have been attempting to understand, explain and extrapolate on the relationships between higher education funding and political institutions. This review attempts to assess recent studies concerned with US…

  7. A Review of the Conflicting Theories on the Slave Family.

    Davis, David Brion

    1997-01-01

    Historians' changing perceptions of the quality of slave family life are reviewed as they developed from World War I to the present day, noting the paternalism that marked historians' thinking in post-War period, and the romanticism that characterizes some later writings. Controversy over slave family structures continues in present-day studies.…

  8. Transport in nanofluidic systems: a review of theory and applications

    Sparreboom, Wouter; van den Berg, Albert; Eijkel, Jan C.T.

    2010-01-01

    In this paper transport through nanochannels is assessed, both of liquids and of dissolved molecules or ions. First, we review principles of transport at the nanoscale, which will involve the identification of important length scales where transitions in behavior occur. We also present several

  9. Pathogenesis of chronic pancreatitis: an evidence-based review of past theories and recent developments.

    Stevens, Tyler; Conwell, Darwin L; Zuccaro, Gregory

    2004-11-01

    In the past several decades, four prominent theories of chronic pancreatitis pathogenesis have emerged: the toxic-metabolic theory, the oxidative stress hypothesis, the stone and duct obstruction theory, and the necrosis-fibrosis hypothesis. Although these traditional theories are formulated based on compelling scientific observations, substantial contradictory data also exist for each. Furthermore, the basic premises of some of these theories are directly contradictory. Because of the recent scientific progress in the underlying genetic, cellular, and molecular pathophysiology, there have been substantial advances in the understanding of chronic pancreatitis pathogenesis. This paper will provide an evidence-based review and critique of the traditional pathogenic theories, followed by a discussion of the new advances in pancreatic fibrogenesis. Moreover, we will discuss plausible pathogenic sequences applied to each of the known etiologies.

  10. The Wigner phase-space description of collision processes

    Lee, H.W.

    1984-01-01

    The paper concerns the Wigner distribution function in collision theory. Wigner phase-space description of collision processes; some general consideration on Wigner trajectories; and examples of Wigner trajectories; are all discussed. (U.K.)

  11. A review of expectancy theory and alcohol consumption.

    Jones, B T; Corbin, W; Fromme, K

    2001-01-01

    Research is reviewed on the association between alcohol outcome expectancies and consumption which has led many to argue that manipulating expectancies might be a route to manipulating consumption for problem prevention and treatment. Studies indirectly and directly evaluating this latter position are reviewed. Expectancies predicting treatment outcome: two studies have shown that the more positive expectancies held at treatment, the poorer is treatment outcome, but five other studies have failed to find this. Three related studies have shown that the more negative expectancies held at treatment, the better the treatment outcome. This evaluation provides evidence inconsistent with the main position for positive expectancy and limited support for negative. Expectancy manipulations and ad libitum consumption: three studies in the laboratory have shown that increasing positive expectancies through word priming increases subsequent consumption and two studies have shown that increasing negative expectancies decreases it. A single study in the field showed a similar relationship. This evaluation provides evidence consistent with the main position but is limited by measuring consumption changes over only 1-2 hours. Prevention programmes with expectancy components: seven projects are reviewed in which positive expectancies were targeted, but only two report an expectancy change analysis and in both cases the expectancy change did not relate to subsequent consumption. This evaluation provides evidence inconsistent with the main position. Expectancy challenge: two related studies are reviewed in which positive expectancy challenges reduce subsequent consumption but changes in expectancy were not evaluated as predictors of consumption change. Two studies are reviewed which found a reduction in positive expectancy following expectancy challenge but no reduction in consumption. One study is reviewed in which when negative expectancy was increased in treatment there was a

  12. Current use was established and Cochrane guidance on selection of social theories for systematic reviews of complex interventions was developed.

    Noyes, Jane; Hendry, Maggie; Booth, Andrew; Chandler, Jackie; Lewin, Simon; Glenton, Claire; Garside, Ruth

    2016-07-01

    To identify examples of how social theories are used in systematic reviews of complex interventions to inform production of Cochrane guidance. Secondary analysis of published/unpublished examples of theories of social phenomena for use in reviews of complex interventions identified through scoping searches, engagement with key authors and methodologists supplemented by snowballing and reference searching. Theories were classified (low-level, mid-range, grand). Over 100 theories were identified with evidence of proliferation over the last 5 years. New low-level theories (tools, taxonomies, etc) have been developed for classifying and reporting complex interventions. Numerous mid-range theories are used; one example demonstrated how control theory had changed the review's findings. Review-specific logic models are increasingly used, but these can be challenging to develop. New low-level and mid-range psychological theories of behavior change are evolving. No reviews using grand theory (e.g., feminist theory) were identified. We produced a searchable Wiki, Mendeley Inventory, and Cochrane guidance. Use of low-level theory is common and evolving; incorporation of mid-range theory is still the exception rather than the norm. Methodological work is needed to evaluate the contribution of theory. Choice of theory reflects personal preference; application of theory is a skilled endeavor. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  13. HYPOCHONDRIA: A REVIEW OF ITS PLACE IN PSYCHOANALYTIC THEORY.

    Stathopoulos, Georgios

    2017-04-01

    After identifying Freud's fundamental contributions to the concept of hypochondria, the author undertakes a brief review of the term's trajectory within the Anglophone and Francophone psychoanalytic literature. Notions of defense, anxiety, and representation as they relate to corporeal experience are discussed. The author illustrates these main axes with which to read hypochondria with clinical material drawn from the analysis of a woman in whom somatic manifestations were especially pervasive. © 2017 The Psychoanalytic Quarterly, Inc.

  14. The recognition heuristic : A review of theory and tests

    Pachur, T.; Todd, P.; Gigerenzer, G.; Schooler, L.; Goldstein, D.

    2011-01-01

    The recognition heuristic is a prime example of how, by exploiting a match between mind and environment, a simple mental strategy can lead to efficient decision making. The proposal of the heuristic initiated a debate about the processes underlying the use of recognition in decision making. We review research addressing four key aspects of the recognition heuristic: (a) that recognition is often an ecologically valid cue; (b) that people often follow recognition when making inferences; (c) th...

  15. Theories of behaviour and behaviour change across the social and behavioural sciences: a scoping review.

    Davis, Rachel; Campbell, Rona; Hildon, Zoe; Hobbs, Lorna; Michie, Susan

    2015-01-01

    Interventions to change health-related behaviours typically have modest effects and may be more effective if grounded in appropriate theory. Most theories applied to public health interventions tend to emphasise individual capabilities and motivation, with limited reference to context and social factors. Intervention effectiveness may be increased by drawing on a wider range of theories incorporating social, cultural and economic factors that influence behaviour. The primary aim of this paper is to identify theories of behaviour and behaviour change of potential relevance to public health interventions across four scientific disciplines: psychology, sociology, anthropology and economics. We report in detail the methodology of our scoping review used to identify these theories including which involved a systematic search of electronic databases, consultation with a multidisciplinary advisory group, web searching, searching of reference lists and hand searching of key behavioural science journals. Of secondary interest we developed a list of agreed criteria for judging the quality of the theories. We identified 82 theories and 9 criteria for assessing theory quality. The potential relevance of this wide-ranging number of theories to public health interventions and the ease and usefulness of evaluating the theories in terms of the quality criteria are however yet to be determined.

  16. REVIEW OF FDI THEORY IN THE KNOWLEDGE–INTENSIVE ECONOMY

    Ruslan Harasym

    2013-02-01

    Full Text Available International flow of capital in the form of Foreign Direct Investment (FDI is considered to be the primary form of capital transfer in the global economy. It plays an important role among other forms of international capital flows, due to the intensity of its streams and its strength of impact on local economies. Host countries use FDI to finance activities such as industry restructuring and transfer of technology. The aim of this paper is to present current achievements in the field of theoretical explanations of FDI – its main motives. The article relates also to current selected trends in FDI flows during the economic downturn caused by the recent financial crisis. Above all ,however, this paper aims at showing FDI theories in terms of a knowledge intensive economy.

  17. BOOK REVIEW: Theory of Neural Information Processing Systems

    Galla, Tobias

    2006-04-01

    It is difficult not to be amazed by the ability of the human brain to process, to structure and to memorize information. Even by the toughest standards the behaviour of this network of about 1011 neurons qualifies as complex, and both the scientific community and the public take great interest in the growing field of neuroscience. The scientific endeavour to learn more about the function of the brain as an information processing system is here a truly interdisciplinary one, with important contributions from biology, computer science, physics, engineering and mathematics as the authors quite rightly point out in the introduction of their book. The role of the theoretical disciplines here is to provide mathematical models of information processing systems and the tools to study them. These models and tools are at the centre of the material covered in the book by Coolen, Kühn and Sollich. The book is divided into five parts, providing basic introductory material on neural network models as well as the details of advanced techniques to study them. A mathematical appendix complements the main text. The range of topics is extremely broad, still the presentation is concise and the book well arranged. To stress the breadth of the book let me just mention a few keywords here: the material ranges from the basics of perceptrons and recurrent network architectures to more advanced aspects such as Bayesian learning and support vector machines; Shannon's theory of information and the definition of entropy are discussed, and a chapter on Amari's information geometry is not missing either. Finally the statistical mechanics chapters cover Gardner theory and the replica analysis of the Hopfield model, not without being preceded by a brief introduction of the basic concepts of equilibrium statistical physics. The book also contains a part on effective theories of the macroscopic dynamics of neural networks. Many dynamical aspects of neural networks are usually hard to find in the

  18. A short review of game theory for neurosurgeons.

    Steiger, H-J; Steiger, U R

    2011-02-01

    Neurosurgery and medicine in general are increasingly dominated by economic factors and considerations. Physicians themselves have partially adopted economic terminology, although they rarely have a profound knowledge of economics. Today game theory is one of the most important factors driving microeconomics, which is the competition for limited resources within a small group of individuals. The purpose of this article is to give a short introduction to game theory and its application to the healthcare system. The Prisoner's Dilemma considers strategies between two persons. In the classic version two burglars are caught. Each could confess and be released from jail if the other does not confess--who will then get a long term in prison. If both confess, both get an intermediate time in jail, and if no one confesses, both get a mild sentence. Wanting to be released from jail, they both confess and get the intermediate term in prison. This remarkable result, initially described by John von Neumann in 1928 and showing that individually rational actions can result in both persons becoming worse off, had a great impact on modern social science. Other scenarios are more complex. The Nash Equilibrium is a wider concept. If there is a set of strategies with the property that no player can benefit by changing his strategy while the other players keep their strategies unchanged, then that set of strategies and the corresponding payoffs constitute the Nash Equilibrium. Another concept particularly important in sociology is the Pareto criterion. If no one can be made better off without making somebody else worse off, then that outcome is Pareto optimal. Respecting these basic principles is a necessary precondition for successful deals and cooperative projects. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Applications of social constructivist learning theories in knowledge translation for healthcare professionals: a scoping review.

    Thomas, Aliki; Menon, Anita; Boruff, Jill; Rodriguez, Ana Maria; Ahmed, Sara

    2014-05-06

    Use of theory is essential for advancing the science of knowledge translation (KT) and for increasing the likelihood that KT interventions will be successful in reducing existing research-practice gaps in health care. As a sociological theory of knowledge, social constructivist theory may be useful for informing the design and evaluation of KT interventions. As such, this scoping review explored the extent to which social constructivist theory has been applied in the KT literature for healthcare professionals. Searches were conducted in six databases: Ovid MEDLINE (1948 - May 16, 2011), Ovid EMBASE, CINAHL, ERIC, PsycInfo, and AMED. Inclusion criteria were: publications from all health professions, research methodologies, as well as conceptual and theoretical papers related to KT. To be included in the review, key words such as constructivism, social constructivism, or social constructivist theories had to be included within the title or abstract. Papers that discussed the use of social constructivist theories in the context of undergraduate learning in academic settings were excluded from the review. An analytical framework of quantitative (numerical) and thematic analysis was used to examine and combine study findings. Of the 514 articles screened, 35 papers published between 1992 and 2011 were deemed eligible and included in the review. This review indicated that use of social constructivist theory in the KT literature was limited and haphazard. The lack of justification for the use of theory continues to represent a shortcoming of the papers reviewed. Potential applications and relevance of social constructivist theory in KT in general and in the specific studies were not made explicit in most papers. For the acquisition, expression and application of knowledge in practice, there was emphasis on how the social constructivist theory supports clinicians in expressing this knowledge in their professional interactions. This scoping review was the first to examine

  20. Applications of social constructivist learning theories in knowledge translation for healthcare professionals: a scoping review

    2014-01-01

    Background Use of theory is essential for advancing the science of knowledge translation (KT) and for increasing the likelihood that KT interventions will be successful in reducing existing research-practice gaps in health care. As a sociological theory of knowledge, social constructivist theory may be useful for informing the design and evaluation of KT interventions. As such, this scoping review explored the extent to which social constructivist theory has been applied in the KT literature for healthcare professionals. Methods Searches were conducted in six databases: Ovid MEDLINE (1948 – May 16, 2011), Ovid EMBASE, CINAHL, ERIC, PsycInfo, and AMED. Inclusion criteria were: publications from all health professions, research methodologies, as well as conceptual and theoretical papers related to KT. To be included in the review, key words such as constructivism, social constructivism, or social constructivist theories had to be included within the title or abstract. Papers that discussed the use of social constructivist theories in the context of undergraduate learning in academic settings were excluded from the review. An analytical framework of quantitative (numerical) and thematic analysis was used to examine and combine study findings. Results Of the 514 articles screened, 35 papers published between 1992 and 2011 were deemed eligible and included in the review. This review indicated that use of social constructivist theory in the KT literature was limited and haphazard. The lack of justification for the use of theory continues to represent a shortcoming of the papers reviewed. Potential applications and relevance of social constructivist theory in KT in general and in the specific studies were not made explicit in most papers. For the acquisition, expression and application of knowledge in practice, there was emphasis on how the social constructivist theory supports clinicians in expressing this knowledge in their professional interactions. Conclusions This

  1. Energy shocks, crises and the policy process: A review of theory and application

    Grossman, Peter Z.

    2015-01-01

    What motivates changes in energy policy? Typically, the process begins with a notable exogenous event, a shock. Often, the shock leads to what is perceived to be a crisis. This review essay surveys theories of crisis policymaking from the social science literature and considers their application to changes in energy policy. Two cases — one from the U.S., the other from Germany — are examined in more detail from the standpoint of the theories discussed. Suggestions are made for improving energy policy analysis in the future. - Highlights: • An analysis of the idea of “crisis” and its application to energy. • A review of theories and models of the policy process and of policy change. • Theory applied to two energy cases. • Suggestion as to how the analysis of energy policymaking might be approached in the future

  2. Theories relating baryon asymmetry and dark matter: a Mini review

    Stefano eMorisi

    2014-01-01

    Full Text Available The nature of dark matter and the origin of the baryon asymmetry are two of the deepest mysteries of modern particle physics. In the absence of hints regarding a possible solution to these mysteries, many approaches have been developed to tackle them simultaneously { leading to very diverse and rich models}. We give a short review where we describe the general features of some of these models and an overview on the general problem. We also propose a diagrammatic notation to label the different models.

  3. Muon-catalyzed fusion theory - introduction and review

    Cohen, J.S.

    1990-01-01

    Muon-catalyzed fusion (μCF) has proved to be a fruitful subject for basic physics research as well as a source of cold nuclear fusion. Experiments have demonstrated that over 100 fusions per muon can be catalyzed by formation of the dtμ molecules in mixtures of deuterium and tritium. After a brief review of the subject's history, the dtμ catalysis cycle and the principle relations used in its analysis are described. Some of the important processes in the μCF cycle are then discussed. Finally, the status of current research is appraised. (author)

  4. Study of local response effects in interatomic collisions with two active electrons in the framework of time-dependent density functional theory; Untersuchung lokaler Responseffekte in interatomaren Stoessen mit zwei aktiven Elektronen im Rahmen zeitabhaengiger Dichtefunktionaltheorie

    Keim, M.

    2005-07-01

    In the present thesis response effects in interatomic collisions with two active electrons are studied in the range of non-relativistic collision energies. The starting point is the mapping of the time-dependent interacting many-electron sytem on an effective one-particle picture on the base of the time-dependent density functional theory (TDDFT). By means of the basis generator method the one-particle equations aring in the framework of the TDDFT concept are solved in a finite-dimensional model space. In the study of ionization cross section in the collisional systeem anti p+He it is shown that by response effects an essential diminuishing of the cross sections in comparison to the no-response case is reached. Analoguously the ionization cross sections for the collisional systems p-He, He{sup 2+}-He, Li{sup 3+}-He and p-Li{sup +} behave.

  5. Public health ethics theory: review and path to convergence.

    Lee, Lisa M

    2012-01-01

    Public health ethics is a nascent field, emerging over the past decade as an applied field merging concepts of clinical and research ethics. Because the "patient" in public health is the population rather than the individual, existing principles might be weighted differently, or there might be different ethical principles to consider. This paper reviewed the evolution of public health ethics, the use of bioethics as its model, and the proposed frameworks for public health ethics through 2010. Review of 13 major public health ethics frameworks published over the past 15 years yields a wide variety of theoretical approaches, some similar foundational values, and a few similar operating principles. Coming to a consensus on the reach, purpose, and ends of public health is necessary if we are to agree on what ethical underpinnings drive us, what foundational values bring us to these underpinnings, and what operating principles practitioners must implement to make ethical decisions. If public health is distinct enough from clinical medicine to warrant its own set of ethical and philosophical underpinnings, then a decision must be made as to whether a single approach is warranted or we can tolerate a variety of equal but different perspectives. © 2012 American Society of Law, Medicine & Ethics, Inc.

  6. Predicting actual weight loss: A review of the determinants according to the theory of planned behaviour.

    Chung, Louisa Ming Yan; Fong, Shirley Siu Ming

    2015-01-01

    Weight reduction that corresponds with lifestyle modification is difficult to foster. The theory of planned behaviour has been actively cited in explaining health-related behaviour. This review evaluated the application of the theory of planned behaviour to weight-loss behaviour. Among the three reviewed papers, cross-sectional survey designs and subjective outcome measurements were commonly applied. All of the studies recruited obese female adults as participants, limiting the generalisability of the studies' findings. The theory of planned behaviour can be effectively applied in weight-reduction programmes targeting female obese patients. This review confirmed critiques citing the limitations of experimental studies, the subjective measurement of behaviour and short follow-up periods.

  7. Theory of Belief Functions for Data Analysis and Machine Learning Applications: Review and Prospects

    Denoeux, Thierry

    The Dempster-Shafer theory of belief functions provides a unified framework for handling both aleatory uncertainty, arising from statistical variability in populations, and epistemic uncertainty, arising from incompleteness of knowledge. An overview of both the fundamentals and some recent developments in this theory will first be presented. Several applications in data analysis and machine learning will then be reviewed, including learning under partial supervision, multi-label classification, ensemble clustering and the treatment of pairwise comparisons in sensory or preference analysis.

  8. Deep inelastic collisions viewed as Brownian motion

    Gross, D.H.E.; Freie Univ. Berlin

    1980-01-01

    Non-equilibrium transport processes like Brownian motion, are studied since perhaps 100 years and one should ask why does one not use these theories to explain deep inelastic collision data. These theories have reached a high standard of sophistication, experience, and precision that I believe them to be very usefull for our problem. I will try to sketch a possible form of an advanced theory of Brownian motion that seems to be suitable for low energy heavy ion collisions. (orig./FKS)

  9. Theories, models and frameworks used in capacity building interventions relevant to public health: a systematic review.

    Bergeron, Kim; Abdi, Samiya; DeCorby, Kara; Mensah, Gloria; Rempel, Benjamin; Manson, Heather

    2017-11-28

    There is limited research on capacity building interventions that include theoretical foundations. The purpose of this systematic review is to identify underlying theories, models and frameworks used to support capacity building interventions relevant to public health practice. The aim is to inform and improve capacity building practices and services offered by public health organizations. Four search strategies were used: 1) electronic database searching; 2) reference lists of included papers; 3) key informant consultation; and 4) grey literature searching. Inclusion and exclusion criteria are outlined with included papers focusing on capacity building, learning plans, professional development plans in combination with tools, resources, processes, procedures, steps, model, framework, guideline, described in a public health or healthcare setting, or non-government, government, or community organizations as they relate to healthcare, and explicitly or implicitly mention a theory, model and/or framework that grounds the type of capacity building approach developed. Quality assessment were performed on all included articles. Data analysis included a process for synthesizing, analyzing and presenting descriptive summaries, categorizing theoretical foundations according to which theory, model and/or framework was used and whether or not the theory, model or framework was implied or explicitly identified. Nineteen articles were included in this review. A total of 28 theories, models and frameworks were identified. Of this number, two theories (Diffusion of Innovations and Transformational Learning), two models (Ecological and Interactive Systems Framework for Dissemination and Implementation) and one framework (Bloom's Taxonomy of Learning) were identified as the most frequently cited. This review identifies specific theories, models and frameworks to support capacity building interventions relevant to public health organizations. It provides public health practitioners

  10. "Theory of mind" in schizophrenia: a review of the literature.

    Brüne, Martin

    2005-01-01

    The term theory of mind (ToM) refers to the capacity to infer one's own and other persons' mental states. A substantial body of research has highlighted the evolution of ToM in nonhuman primates, its emergence during human ontogeny, and impaired ToM in a variety of neuropsychiatric disorders, including schizophrenia. There is good empirical evidence that ToM is specifically impaired in schizophrenia and that many psychotic symptoms-for instance, delusions of alien control and persecution, the presence of thought and language disorganization, and other behavioral symptoms-may best be understood in light of a disturbed capacity in patients to relate their own intentions to executing behavior, and to monitor others' intentions. However, it is still under debate how an impaired ToM in schizophrenia is associated with other aspects of cognition, how the impairment fluctuates with acuity or chronicity of the schizophrenic disorder, and how this affects the patients' use of language and social behavior. In addition to these potential research areas, future studies may also address whether patients could benefit from cognitive training in this domain.

  11. BOOK REVIEW: Gravitational Waves, Volume 1: Theory and Experiments

    Poisson, Eric

    2008-10-01

    discussion is helpful, as it clarifies some of the puzzling aspects of general covariance. Next the treatment becomes more sophisticated: the waves are allowed to propagate in an arbitrary background spacetime, and the energy momentum carried by the wave is identified by the second-order perturbation of the Einstein tensor. In chapter 2 the waves are given a field-theoretic foundation that is less familiar (but refreshing) to a relativist, but would appeal to a practitioner of effective field theories. In an interesting section of chapter 2, the author gives a mass to the (classical) graviton and explores the physical consequences of this proposal. In chapter 3 the author returns to the standard linearized theory and develops the multipolar expansion of the gravitational-wave field in the context of slowly-moving sources; at leading order he obtains the famous quadrupole formula. His treatment is very detailed, and it includes a complete account of symmetric-tracefree tensors and tensorial spherical harmonics. It is, however, necessarily limited to sources with negligible internal gravity. Unfortunately (and this is a familiar complaint of relativists) the author omits to warn the reader of this important limitation. In fact, the chapter opens with a statement of the virial theorem of Newtonian gravity, which may well mislead the reader to believe that the linearized theory can be applied to a system bound by gravitational forces. This misconception is confirmed when, in chapter 4, the author applies the quadrupole formula to gravitationally-bound systems such as an inspiraling compact binary, a rigidly rotating body, and a mass falling toward a black hole. This said, the presentation of these main sources of gravitational waves is otherwise irreproachable, and a wealth of useful information is presented in a clear and lucid manner. For example, the discussion of inspiraling compact binaries includes a derivation of the orbital evolution of circular and eccentric orbits

  12. Review of progress in the theory of volume production

    Hiskes, J.R.

    1986-01-01

    With the demonstration of large current densities extracted from hydrogen-discharge-type negative ion sources there has been a new emphasis directed toward the further development of these volume-type sources. Along with this emphasis has been a rapid increase in our understanding of the underlying atomic processes that occur in hydrogen-negative-ion discharges, together with a rapid evolution of the geometric configuration of these ion sources. An account of the development of the atomic processes in negative hydrogen discharges has been given in a recent review. Here we shall emphasize these atomic developments as they bear on the tandem high-density ion-source configuration. 32 refs., 10 figs

  13. Review of the Fusion Theory and Computing Program. Fusion Energy Sciences Advisory Committee (FESAC)

    Antonsen, Thomas M.; Berry, Lee A.; Brown, Michael R.; Dahlburg, Jill P.; Davidson, Ronald C.; Greenwald, Martin; Hegna, Chris C.; McCurdy, William; Newman, David E.; Pellegrini, Claudio; Phillips, Cynthia K.; Post, Douglass E.; Rosenbluth, Marshall N.; Sheffield, John; Simonen, Thomas C.; Van Dam, James

    2001-01-01

    At the November 14-15, 2000, meeting of the Fusion Energy Sciences Advisory Committee, a Panel was set up to address questions about the Theory and Computing program, posed in a charge from the Office of Fusion Energy Sciences (see Appendix A). This area was of theory and computing/simulations had been considered in the FESAC Knoxville meeting of 1999 and in the deliberations of the Integrated Program Planning Activity (IPPA) in 2000. A National Research Council committee provided a detailed review of the scientific quality of the fusion energy sciences program, including theory and computing, in 2000.

  14. The nuclear response in extended RPA theories

    Wambach, J.

    1991-01-01

    Linear response theories for small-amplitude nuclear motion are discussed. A review is given of the Random-Phase-Approximation and its successes and shortcomings are pointed out. Systematic improvements are presented which include two-particle two-hole excitations and account for dissipative effects due to binary collisions of nucleons in the mean field. These improved theories describe inelastic scattering experiments satisfactorily over a wide kinematical range. (author)

  15. Review of network research in scientific journal ‘Entrepreneurship Theory and Practice’

    Agnieszka Brzozowska

    2016-10-01

    Full Text Available This article aims at presenting a systematic review of publications that verified the network theory and the theory of networks empirically, published in the entrepreneurship journal with the highest Impact Factor: “Entrepreneurship Theory and Practice”. We present how publication frequency evolved over time, and classify papers into major streams of entrepreneurship research. Our findings suggest the theory of networks is an under-researched area promising for further advancing the theory of entrepreneurship. We also find increasing publication frequency of network related research over time. Results oriented research were most often present in reviewed articles, while relationship among network variables and innovation was only tested in two articles so far which suggests that more research is needed in this direction in the future. We belief that verification of theories of networks in entrepreneurship and verification of relationship between network variables and innovation within the network theory are most promising. The originality of this work lies in identification of research opportunities and dynamics of empirical verification of network studies in the field of entrepreneurship.

  16. Theoretical explanations for maintenance of behaviour change: a systematic review of behaviour theories.

    Kwasnicka, Dominika; Dombrowski, Stephan U; White, Martin; Sniehotta, Falko

    2016-09-01

    Behaviour change interventions are effective in supporting individuals in achieving temporary behaviour change. Behaviour change maintenance, however, is rarely attained. The aim of this review was to identify and synthesise current theoretical explanations for behaviour change maintenance to inform future research and practice. Potentially relevant theories were identified through systematic searches of electronic databases (Ovid MEDLINE, Embase, PsycINFO). In addition, an existing database of 80 theories was searched, and 25 theory experts were consulted. Theories were included if they formulated hypotheses about behaviour change maintenance. Included theories were synthesised thematically to ascertain overarching explanations for behaviour change maintenance. Initial theoretical themes were cross-validated. One hundred and seventeen behaviour theories were identified, of which 100 met the inclusion criteria. Five overarching, interconnected themes representing theoretical explanations for behaviour change maintenance emerged. Theoretical explanations of behaviour change maintenance focus on the differential nature and role of motives, self-regulation, resources (psychological and physical), habits, and environmental and social influences from initiation to maintenance. There are distinct patterns of theoretical explanations for behaviour change and for behaviour change maintenance. The findings from this review can guide the development and evaluation of interventions promoting maintenance of health behaviours and help in the development of an integrated theory of behaviour change maintenance.

  17. Theoretical explanations for maintenance of behaviour change: a systematic review of behaviour theories

    Kwasnicka, Dominika; Dombrowski, Stephan U; White, Martin; Sniehotta, Falko

    2016-01-01

    ABSTRACT Background: Behaviour change interventions are effective in supporting individuals in achieving temporary behaviour change. Behaviour change maintenance, however, is rarely attained. The aim of this review was to identify and synthesise current theoretical explanations for behaviour change maintenance to inform future research and practice. Methods: Potentially relevant theories were identified through systematic searches of electronic databases (Ovid MEDLINE, Embase, PsycINFO). In addition, an existing database of 80 theories was searched, and 25 theory experts were consulted. Theories were included if they formulated hypotheses about behaviour change maintenance. Included theories were synthesised thematically to ascertain overarching explanations for behaviour change maintenance. Initial theoretical themes were cross-validated. Findings: One hundred and seventeen behaviour theories were identified, of which 100 met the inclusion criteria. Five overarching, interconnected themes representing theoretical explanations for behaviour change maintenance emerged. Theoretical explanations of behaviour change maintenance focus on the differential nature and role of motives, self-regulation, resources (psychological and physical), habits, and environmental and social influences from initiation to maintenance. Discussion: There are distinct patterns of theoretical explanations for behaviour change and for behaviour change maintenance. The findings from this review can guide the development and evaluation of interventions promoting maintenance of health behaviours and help in the development of an integrated theory of behaviour change maintenance. PMID:26854092

  18. Systematic review of empiricism and theory in domestic minor sex trafficking research.

    Twis, Mary K; Shelton, Beth Anne

    2018-01-01

    Empiricism and the application of human behavior theory to inquiry are regarded as markers of high-quality research. Unfortunately, scholars have noted that there are many gaps in theory and empiricism within the human trafficking literature, calling into question the legitimacy of policies and practices that are derived from the available data. To date, there has not been an analysis of the extent to which empirical methods and human behavior theory have been applied to domestic minor sex trafficking (DMST) research as a subcategory of human trafficking inquiry. To fill this gap in the literature, this systematic review was designed to assess the degree to which DMST publications are a) empirical, and b) apply human behavior theory to inquiry. This analysis also focuses on answering research questions related to patterns within DMST study data sources, and patterns of human behavior theory application. The results of this review indicate that a minority of sampled DMST publications are empirical, a minority of those articles that were empirical apply a specific human behavior theory within the research design and reporting of results, a minority of articles utilize data collected directly from DMST victims, and that there are no discernible patterns in the application of human behavior theory to DMST research. This research note suggests that DMST research is limited by the same challenges as the larger body of human trafficking scholarship. Based upon these overarching findings, specific recommendations are offered to DMST researchers who are committed to enhancing the quality of DMST scholarship.

  19. QCD in heavy ion collisions

    Iancu, Edmond [IPhT, Saclay (France)

    2014-07-01

    These lectures provide a modern introduction to selected topics in the physics of ultrarelativistic heavy ion collisions which shed light on the fundamental theory of strong interactions, the Quantum Chromodynamics. The emphasis is on the partonic forms of QCD matter which exist in the early and intermediate stages of a collision -- the colour glass condensate, the glasma, and the quark-gluon plasma -- and on the effective theories that are used for their description. These theories provide qualitative and even quantitative insight into a wealth of remarkable phenomena observed in nucleus-nucleus or deuteron-nucleus collisions at RHIC and/or the LHC, like the suppression of particle production and of azimuthal correlations at forward rapidities, the energy and centrality dependence of the multiplicities, the ridge effect, the limiting fragmentation, the jet quenching, or the dijet asymmetry.

  20. QCD in heavy ion collisions

    Iancu, Edmond

    2014-01-01

    These lectures provide a modern introduction to selected topics in the physics of ultrarelativistic heavy ion collisions which shed light on the fundamental theory of strong interactions, the Quantum Chromodynamics. The emphasis is on the partonic forms of QCD matter which exist in the early and intermediate stages of a collision -- the colour glass condensate, the glasma, and the quark-gluon plasma -- and on the effective theories that are used for their description. These theories provide qualitative and even quantitative insight into a wealth of remarkable phenomena observed in nucleus-nucleus or deuteron-nucleus collisions at RHIC and/or the LHC, like the suppression of particle production and of azimuthal correlations at forward rapidities, the energy and centrality dependence of the multiplicities, the ridge effect, the limiting fragmentation, the jet quenching, or the dijet asymmetry

  1. BOOK REVIEW: Plasma and Fluid Turbulence: Theory and Modelling

    Yoshizawa, A.; Itoh, S. I.; Itoh, K.

    2003-03-01

    The area of turbulence has been covered by many books over the years. This has, of course, mainly been fluid turbulence, while the area of plasma turbulence has been treated much less. This book by Yoshizawa et al covers both plasma and fluid turbulence, in a way that does justice to both areas at the same time as cross-disciplinary aspects are illuminated. The book should be useful to physicists working in both areas partly because it examines fundamental aspects in a pedagogical way, partly because it is up to date and partly because of the cross-disciplinary aspects which enrich both areas. It is written as an advanced textbook. The reader should have previous knowledge of at least one of the areas and also some background in statistical physics. The book starts with the very important and highly up to date area of structure formation which is relevant both to fluids and plasmas. Here, pipe flow of fluids is treated as an introduction to the area, then follows discussion of the generation of magnetic fields by turbulent motion in stellar objects and stucture formation in plasmas confined by a magnetic field. Also the concept of bifurcation is introduced. This part builds up knowledge from the simple fluid case to the problems of magnetic confinement of plasmas in a very pedagogical way. It continues by introducing the fundamentals of fluid turbulence. This is done very systematically and concepts useful for industrial applications like the K-e method and several ways of heuristic modelling are introduced. Also the two dimensional vortex equation, which is also relevant to magnetized plasmas is introduced. In chapter 5 the statistical theory of turbulence is treated. It starts with a very nice and easy to understand example of renormalization of a simple nonlinear equation where the exact solution is known. It introduces the method of partial renormalization, Greens functions and the direct interaction approximation (DIA). The book then continues with an

  2. Laser-assisted atom-atom collisions

    Roussel, F.

    1984-01-01

    The basic layer-assisted atom-atom collision processes are reviewed in order to get a simpler picture of the main physical facts. The processes can be separated into two groups: optical collisions where only one atom is changing state during the collision, the other acting as a spectator atom, and radiative collisions where the states of the two atoms are changing during the collision. All the processes can be interpreted in terms of photoexcitation of the quasimolecule formed during the collisional process. (author)

  3. BOOK REVIEW: Classical Solutions in Quantum Field Theory Classical Solutions in Quantum Field Theory

    Mann, Robert

    2013-02-01

    Quantum field theory has evolved from its early beginnings as a tool for understanding the interaction of light with matter into a rather formidable technical paradigm, one that has successfully provided the mathematical underpinnings of all non-gravitational interactions. Over the eight decades since it was first contemplated the methods have become increasingly more streamlined and sophisticated, yielding new insights into our understanding of the subatomic world and our abilities to make clear and precise predictions. Some of the more elegant methods have to do with non-perturbative and semiclassical approaches to the subject. The chief players here are solitons, instantons, and anomalies. Over the past three decades there has been a steady rise in our understanding of these objects and of our ability to calculate their effects and implications for the rest of quantum field theory. This book is a welcome contribution to this subject. In 12 chapters it provides a clear synthesis of the key developments in these subjects at a level accessible to graduate students that have had an introductory course to quantum field theory. In the author's own words it provides both 'a survey and an overview of this field'. The first half of the book concentrates on solitons--kinks, vortices, and magnetic monopoles--and their implications for the subject. The reader is led first through the simplest models in one spatial dimension, into more sophisticated cases that required more advanced topological methods. The author does quite a nice job of introducing the various concepts as required, and beginning students should be able to get a good grasp of the subject directly from the text without having to first go through the primary literature. The middle part of the book deals with the implications of these solitons for both cosmology and for duality. While the cosmological discussion is quite nice, the discussion on BPS solitons, supersymmetry and duality is rather condensed. It is

  4. The recognition heuristic: a review of theory and tests.

    Pachur, Thorsten; Todd, Peter M; Gigerenzer, Gerd; Schooler, Lael J; Goldstein, Daniel G

    2011-01-01

    The recognition heuristic is a prime example of how, by exploiting a match between mind and environment, a simple mental strategy can lead to efficient decision making. The proposal of the heuristic initiated a debate about the processes underlying the use of recognition in decision making. We review research addressing four key aspects of the recognition heuristic: (a) that recognition is often an ecologically valid cue; (b) that people often follow recognition when making inferences; (c) that recognition supersedes further cue knowledge; (d) that its use can produce the less-is-more effect - the phenomenon that lesser states of recognition knowledge can lead to more accurate inferences than more complete states. After we contrast the recognition heuristic to other related concepts, including availability and fluency, we carve out, from the existing findings, some boundary conditions of the use of the recognition heuristic as well as key questions for future research. Moreover, we summarize developments concerning the connection of the recognition heuristic with memory models. We suggest that the recognition heuristic is used adaptively and that, compared to other cues, recognition seems to have a special status in decision making. Finally, we discuss how systematic ignorance is exploited in other cognitive mechanisms (e.g., estimation and preference).

  5. The Recognition Heuristic: A Review of Theory and Tests

    Thorsten ePachur

    2011-07-01

    Full Text Available The recognition heuristic is a prime example of how, by exploiting a match between mind and environment, a simple mental strategy can lead to efficient decision making. The proposal of the heuristic initiated a debate about the processes underlying the use of recognition in decision making. We review research addressing four key aspects of the recognition heuristic: (a that recognition is often an ecologically valid cue; (b that people often follow recognition when making inferences; (c that recognition supersedes further cue knowledge; (d that its use can produce the less-is-more effect—the phenomenon that lesser states of recognition knowledge can lead to more accurate inferences than more complete states. After we contrast the recognition heuristic to other related concepts, including availability and fluency, we carve out, from the existing findings, some boundary conditions of the use of the recognition heuristic as well as key questions for future research. Moreover, we summarize developments concerning the connection of the recognition heuristic with memory models. We suggest that the recognition heuristic is used adaptively and that, compared to other cues, recognition seems to have a special status in decision making. Finally, we discuss how systematic ignorance is exploited in other cognitive mechanisms (e.g., estimation and preference.

  6. The Recognition Heuristic: A Review of Theory and Tests

    Pachur, Thorsten; Todd, Peter M.; Gigerenzer, Gerd; Schooler, Lael J.; Goldstein, Daniel G.

    2011-01-01

    The recognition heuristic is a prime example of how, by exploiting a match between mind and environment, a simple mental strategy can lead to efficient decision making. The proposal of the heuristic initiated a debate about the processes underlying the use of recognition in decision making. We review research addressing four key aspects of the recognition heuristic: (a) that recognition is often an ecologically valid cue; (b) that people often follow recognition when making inferences; (c) that recognition supersedes further cue knowledge; (d) that its use can produce the less-is-more effect – the phenomenon that lesser states of recognition knowledge can lead to more accurate inferences than more complete states. After we contrast the recognition heuristic to other related concepts, including availability and fluency, we carve out, from the existing findings, some boundary conditions of the use of the recognition heuristic as well as key questions for future research. Moreover, we summarize developments concerning the connection of the recognition heuristic with memory models. We suggest that the recognition heuristic is used adaptively and that, compared to other cues, recognition seems to have a special status in decision making. Finally, we discuss how systematic ignorance is exploited in other cognitive mechanisms (e.g., estimation and preference). PMID:21779266

  7. Synaesthesia and learning: A critical review and novel theory

    Marcus Robert Watson

    2014-02-01

    Full Text Available Learning and synaesthesia are profoundly interconnected. On the one hand, the development of synaesthesia is clearly influenced by learning. Synaesthetic inducers—the stimuli that evoke these unusual experiences—often involve the perception of complex properties learned in early childhood, e.g. letters, musical notes, numbers, months of the year and even swimming strokes. Further, recent research has shown that the associations individual synaesthetes make with these learned inducers are not arbitrary, but are strongly influenced by the structure of the learnt do- main. For instance, the synaesthetic colours of letters are partially determined by letter frequency and the relative positions of letters in the alphabet. On the other hand, there is also a small, but growing, body of literature which shows that synaesthesia can influence or be helpful in learning. For instance, synaesthetes appear to be able to use their unusual experiences as mnemonic de- vices and can even exploit them while learning novel abstract categories. Here we review these two directions of influence and argue that they are interconnected. We propose that synaesthesia arises, at least in part, because of the cognitive demands of learning in childhood, and that it is used to aid perception and understanding of a variety of learned categories. Our thesis is that the structural similarities between synaesthetic triggering stimuli and synaesthetic experiences are the remnants, the fossilized traces, of past learning challenges for which synasethesia was helpful.

  8. Intelligent control-II: review of fuzzy systems and theory of approximate reasoning

    Nagrial, M.H.

    2004-01-01

    Fuzzy systems are knowledge-based or rule-based systems. The heart of a fuzzy systems knowledge base consisting of the so-called fuzzy IF -THEN rules. This paper reviews various aspects of fuzzy IF-THEN rules. The theory of approximate reasoning, which provides a powerful framework for reasoning the imprecise and uncertain information, , is also reviewed. Additional properties of fuzzy systems are also discussed. (author)

  9. Boiling in microchannels: a review of experiment and theory

    Thome, John R.

    2004-01-01

    A summary of recent research on boiling in microchannels is presented. The review addresses the topics of macroscale versus microscale heat transfer, two-phase flow regimes, flow boiling heat transfer results for microchannels, heat transfer mechanisms in microchannels and flow boiling models for microchannels. In microchannels, the most dominant flow regime appears to be the elongated bubble mode that can persist up to vapor qualities as high as 60-70% in microchannels, followed by annular flow. Flow boiling heat transfer coefficients have been shown experimentally to be dependent on heat flux and saturation pressure while only slightly dependent on mass velocity and vapor quality. Hence, these studies have concluded that nucleate boiling controls evaporation in microchannels. Instead, a recent analytical study has shown that transient evaporation of the thin liquid films surrounding elongated bubbles is the dominant heat transfer mechanism as opposed to nucleate boiling and is able to predict these trends in the experimental data. Newer experimental studies have further shown that there is in fact a significant effect of mass velocity and vapor quality on heat transfer when covering a broader range of conditions, including a sharp peak at low vapor qualities at high heat fluxes. Furthermore, it is concluded that macroscale models are not realistic for predicting flowing boiling coefficients in microchannels as the controlling mechanism is not nucleate boiling nor turbulent convection but is transient thin film evaporation (also, microchannel flows are typically laminar and not turbulent as assumed by macroscopic models). A more advanced three-zone flow boiling model for evaporation of elongated bubbles in microchannels is currently under development that so far qualitatively describes all these trends. Numerous fundamental aspects of two-phase flow and evaporation remain to be better understood and some of these aspects are also discussed

  10. Reconceptualizing children's complex discharge with health systems theory: novel integrative review with embedded expert consultation and theory development.

    Noyes, Jane; Brenner, Maria; Fox, Patricia; Guerin, Ashleigh

    2014-05-01

    To report a novel review to develop a health systems model of successful transition of children with complex healthcare needs from hospital to home. Children with complex healthcare needs commonly experience an expensive, ineffectual and prolonged nurse-led discharge process. Children gain no benefit from prolonged hospitalization and are exposed to significant harm. Research to enable intervention development and process evaluation across the entire health system is lacking. Novel mixed-method integrative review informed by health systems theory. DATA  CINAHL, PsychInfo, EMBASE, PubMed, citation searching, personal contact. REVIEW  Informed by consultation with experts. English language studies, opinion/discussion papers reporting research, best practice and experiences of children, parents and healthcare professionals and purposively selected policies/guidelines from 2002-December 2012 were abstracted using Framework synthesis, followed by iterative theory development. Seven critical factors derived from thirty-four sources across five health system levels explained successful discharge (new programme theory). All seven factors are required in an integrated care pathway, with a dynamic communication loop to facilitate effective discharge (new programme logic). Current health system responses were frequently static and critical success factors were commonly absent, thereby explaining ineffectual discharge. The novel evidence-based model, which reconceptualizes 'discharge' as a highly complex longitudinal health system intervention, makes a significant contribution to global knowledge to drive practice development. Research is required to develop process and outcome measures at different time points in the discharge process and future trials are needed to determine the effectiveness of integrated health system discharge models. © 2013 John Wiley & Sons Ltd.

  11. Promoting physical activity in rheumatoid arthritis: a narrative review of behaviour change theories.

    Larkin, Louise; Kennedy, Norelee; Gallagher, Stephen

    2015-01-01

    Despite physical activity having significant health benefits for people with rheumatoid arthritis (RA), current levels of physical activity in this population are suboptimal. Changing behaviour is challenging and interventions aimed at increasing physical activity in this context have had varying levels of success. This review provides an overview of common behaviour change theories used in interventions to promote physical activity and their application for promoting physical activity in people with RA. A scoping, narrative review was conducted of English language literature, using the search terms "physical activity/exercise" and keywords, which are associated with behaviour change interventions. The theoretical basis of such interventions in people with RA was assessed using the "theory coding scheme". Six theories which have been used in physical activity research are discussed. Further, four studies which aimed to increase physical activity levels in people with RA are explored in detail. To date, behaviour change interventions conducted in RA populations to increase physical activity levels have not had a strong theoretical underpinning. It is proposed that an intervention utilising the theory of planned behaviour is developed with the aim of increasing physical activity in people with RA. Implications for Rehabilitation Interventions to promote physical activity in the rheumatoid arthritis (RA) population have failed to change participants' behaviour. A small number of studies have used behaviour change theories in the development and delivery of interventions. The theory of planned behaviour is recommended as the theoretical basis for an intervention to promote physical activity in the RA population.

  12. Scoping review identifies significant number of knowledge translation theories, models and frameworks with limited use.

    Strifler, Lisa; Cardoso, Roberta; McGowan, Jessie; Cogo, Elise; Nincic, Vera; Khan, Paul A; Scott, Alistair; Ghassemi, Marco; MacDonald, Heather; Lai, Yonda; Treister, Victoria; Tricco, Andrea C; Straus, Sharon E

    2018-04-13

    To conduct a scoping review of knowledge translation (KT) theories, models and frameworks that have been used to guide dissemination or implementation of evidence-based interventions targeted to prevention and/or management of cancer or other chronic diseases. We used a comprehensive multistage search process from 2000-2016, which included traditional bibliographic database searching, searching using names of theories, models and frameworks, and cited reference searching. Two reviewers independently screened the literature and abstracted data. We found 596 studies reporting on the use of 159 KT theories, models or frameworks. A majority (87%) of the identified theories, models or frameworks were used in five or fewer studies, with 60% used once. The theories, models and frameworks were most commonly used to inform planning/design, implementation and evaluation activities, and least commonly used to inform dissemination and sustainability/scalability activities. Twenty-six were used across the full implementation spectrum (from planning/design to sustainability/scalability) either within or across studies. All were used for at least individual-level behavior change, while 48% were used for organization-level, 33% for community-level and 17% for system-level change. We found a significant number of KT theories, models and frameworks with a limited evidence base describing their use. Copyright © 2018. Published by Elsevier Inc.

  13. Product-oriented design theory for digital information services: A literature review.

    Wijnhoven, Alphonsus B.J.M.; Kraaijenbrink, Jeroen

    2008-01-01

    Purpose – The purpose of this paper is to give a structured literature review, design concepts, and research propositions related to a product-oriented design theory for information services. Information services facilitate the exchange of information goods with or without transforming these goods.

  14. A Review of Gerald Caplan's "Theory and Practice of Mental Health Consultation."

    Mendoza, Danielle W.

    1993-01-01

    Reviews Caplan's "Theory and Practice of Mental Health Consultation" (1970), considered classic seminal work in field of consultation. Presents Caplan's general definition of consultation and general principles or procedures of consultation. Describes each of Caplan's four models of consultation and compares models in terms of professional role of…

  15. On critical reflection : A review of Mezirow’s theory and its operationalization

    Lundgren, H.; Poell, R.F.

    2016-01-01

    In this article, we review empirical studies that research critical reflection based on Mezirow’s definition. The concepts of content, process, and premise reflection have often been cited, and operationalizing Mezirow’s high-level transformative learning theory and its components has been the

  16. Quark Physics without Quarks: A Review of Recent Developments in S-Matrix Theory.

    Capra, Fritjof

    1979-01-01

    Reviews the developments in S-matrix theory over the past five years which have made it possible to derive results characteristic of quark models without any need to postulate the existence of physical quarks. In the new approach, the quark patterns emerge as a consequence of combining the general S-matrix principles with the concept of order.…

  17. The Task of Reviewing and Finding the Right Organizational Change Theory

    Alase, Abayomi Oluwatosin

    2017-01-01

    Organizational change is probably the singular most important undertaken that many organizations wish they could do to affect their productivities/profitability performances. This review paper will highlight some of the well-known theories and approaches to organizational change. In the late 1990s and early 2000s, America had one of the best…

  18. BOOK REVIEW: Many Worlds?: Everett, Quantum Theory, and Reality Many Worlds?: Everett, Quantum Theory, and Reality

    Wald, Robert M.

    2011-04-01

    Few, if any, issues in physics have engendered as much discussion as the measurement problem in quantum mechanics. It is generally agreed that the `normal' dynamical evolution of the state vector in quantum mechanics is given by a unitary map. The linearity of this map implies that the state vector will, in general, be found in a superposition of eigenstates of a given observable (or, similarly, that the density matrix describing a subsystem will not correspond to a definite value of this observable). However, when we make a measurement of an observable, we always obtain a define value—although it is impossible to predict with certainty which value will be obtained. The traditional response to this issue is to postulate that when a measurement is made, the wavefunction `collapses' to an eigenstate of the observable being measured, perhaps due to the inherent classicality of the measuring apparatus (Bohr), or to the consciousness of the observer (Wigner), or possibly to some modification of quantum dynamics that occurs even when observations are not being made. The main motivation for the Everett (`many worlds') interpretation is to avoid introducing any such collapse postulate. This volume commemorates the 50th anniversary of the publication of Everett's paper in 1957 and contains 20 original articles as well as the transcripts of several discussions that took place at meetings devoted to the Everett interpretation at Oxford University and the Perimeter Institute. The attractiveness of the Everett interpretation is very succinctly summarized by a sentence from Vaidman's contribution (p 582): `The collapse, with its randomness, non-locality and the lack of a well-defined moment of occurrence, is such an ugly scar on quantum theory, that I, along with many others, am ready to follow Everett and deny its existence.' But the main drawback of the interpretation is then equally succinctly stated in the next sentence: `The price is the many worlds interpretation, i

  19. Review of Grain Refinement of Cast Metals Through Inoculation: Theories and Developments

    Liu, Zhilin

    2017-10-01

    The inoculation method of grain refinement is widely used in research and industry. Because of its commercial and engineering importance, extensive research on the mechanisms/theories of grain refinement and development of effective grain refiners for diverse cast metals/alloys has been conducted. In 1999, Easton and St. John reviewed the mechanisms of grain refinement of cast Al alloys. Since then, grain refinement in alloys of Al, Mg, Fe, Ti, Cu, and Zn has evolved a lot. However, there is still no full consensus on the mechanisms/theories of grain refinement. Moreover, some new grain refiners developed based on the theories do not ensure efficient grain refinement. Thus, the factors that contribute to grain refinement are still not fully understood. Clarification of the prerequisite issues that occur in grain refinement is required using recent theories. This review covers multiple metals/alloys and developments in grain refinement from the last twenty years. The characteristics of effective grain refiners are considered from four perspectives: effective particle/matrix wetting configuration, sufficiently powerful segregating elements, preferential crystallographic matching, and geometrical features of effective nucleants. Then, recent mechanisms/theories on the grain refinement of cast metals/alloys are reviewed, including the peritectic-related, hypernucleation, inert nucleant, and constitutional supercooling-driven theories. Further, developments of deterministic and probabilistic modeling and nucleation crystallography in the grain refinement of cast metals are reviewed. Finally, the latest progress in the grain refinement of cast Zn and its alloys is described, and future work on grain refinement is summarized.

  20. Dietary protein to maximize resistance training: a review and examination of protein spread and change theories.

    Bosse, John D; Dixon, Brian M

    2012-09-08

    An appreciable volume of human clinical data supports increased dietary protein for greater gains from resistance training, but not all findings are in agreement. We recently proposed "protein spread theory" and "protein change theory" in an effort to explain discrepancies in the response to increased dietary protein in weight management interventions. The present review aimed to extend "protein spread theory" and "protein change theory" to studies examining the effects of protein on resistance training induced muscle and strength gains. Protein spread theory proposed that there must have been a sufficient spread or % difference in g/kg/day protein intake between groups during a protein intervention to see muscle and strength differences. Protein change theory postulated that for the higher protein group, there must be a sufficient change from baseline g/kg/day protein intake to during study g/kg/day protein intake to see muscle and strength benefits. Seventeen studies met inclusion criteria. In studies where a higher protein intervention was deemed successful there was, on average, a 66.1% g/kg/day between group intake spread versus a 10.2% g/kg/day spread in studies where a higher protein diet was no more effective than control. The average change in habitual protein intake in studies showing higher protein to be more effective than control was +59.5% compared to +6.5% when additional protein was no more effective than control. The magnitudes of difference between the mean spreads and changes of the present review are similar to our previous review on these theories in a weight management context. Providing sufficient deviation from habitual intake appears to be an important factor in determining the success of additional protein in enhancing muscle and strength gains from resistance training. An increase in dietary protein favorably effects muscle and strength during resistance training.

  1. A systematic review of the evidence for impaired cognitive theory of mind in maltreated children

    Xavier eBenarous

    2015-07-01

    Full Text Available Compared to the large number of studies exploring difficulties in emotion recognition in maltreated children, few (N=12 have explored the cognitive aspect of theory of mind, i.e., the ability to understand others’ thoughts and intentions. A systematic review of these studies shows inconsistent results regarding cognitive theory of mind tasks. Youths with a history of maltreatment are more likely to fail at false belief tasks (N=2. However, results are less conclusive regarding other tasks (perspective-taking tasks, N=4; and hostile attribution tasks, N=7. Additionally, only one study controlled for potential psychopathology. Measures of psychopathology and other cognitive abilities, in addition to theory of mind, are required to establish a specific association between maltreatment and the cognitive dimension of theory of mind.

  2. Literature Review of Enterprise Systems Research Using Institutional Theory: Towards a Conceptual Model

    Svejvig, Per

    This paper sets out to examine the use of institutional theory as a conceptually rich lens to study social issues of enterprise systems (ES) research. More precisely, the purpose is to categorize current ES research using institutional theory to develop a conceptual model that advances ES research...... model which advocates for multi-level and multi-theory approaches, and applies newer institutional aspects such as institutional logics. The findings show that institutional theory in ES research is in its infancy and adopts mainly traditional institutional aspects like isomorphism....... Key institutional features are presented such as isomorphism, rationalized myths, bridging macro and micro structures, and institutional logics and their implications for ES research are discussed. Through a literature review of 180 articles, of which 18 papers are selected, we build a conceptual...

  3. Heavy ion collisions

    Siemens, P.J.

    1979-12-01

    The status of research into collisions of nuclei at high energy is reviewed. Reactions and products are classified, and spectator matter is discussed. Then the thermalization of participant matter is considered at some length. Finally, disintegration of the hot matter is addressed. A = 20 and 40 projectiles of 250 to 1050 MeV/A are employed to illustrate the major points. 44 references, 10 figures

  4. Motivation Theories of Maslow, Herzberg, McGregor & McClelland. A Literature Review of Selected Theories Dealing with Job Satisfaction and Motivation.

    Pardee, Ronald L.

    Job satisfaction, motivation, and reward systems are included in one area of organizational theory. The strongest influence in this area is motivation because it overlaps into both of the other two components. A review of the classical literature on motivation reveals four major theory areas: (1) Maslow's Hierarchy of Needs; (2) Herzberg's…

  5. Collision Risk and Damage after Collision

    Pedersen, Preben Terndrup; Hansen, Peter Friis; Nielsen, Lars Peter

    1996-01-01

    The paper presents a new and complete procedure for calculation of ship-ship collision rates on specific routes and the hull damage caused by such collisions.The procedure is applied to analysis of collision risks for Ro-Ro pasenger vessels. Given a collision the spatial probability distribution ...

  6. Alcohol and Masculinity: A Review and Reformulaton of the Sex Role, Dependency, and Power Theories of Alcoholism.

    Lemle, Russell

    This review examines three theories of alcohol abuse by American males: (1) the sex role theory which states that men drink heavily because American culture accepts and encourages that activity in males; (2) the dependency theory, which interprets drinking as a means by which men secretly gratify their dependency needs while manifesting an…

  7. Sociocultural Theories, Academic Achievement, and African American Adolescents in a Multicultural Context: A Review of the Cultural Incompatibility Perspective

    Whaley, Arthur L.; Noel, La

    2011-01-01

    Some theories have posited that African American youth are academic underachievers because of sociocultural factors. We label this point of view the cultural incompatibility perspective. Ogbu's oppositional culture theory and Steele's stereotype threat theory are selected as popular examples of this viewpoint. A critical review of the literature…

  8. Semiholography for heavy ion collisions

    Mukhopadhyay, Ayan

    2017-01-01

    The formation of QGP in heavy ion collisions gives us a great opportunity for learning about nonperturbative dynamics of QCD. Semiholography provides a new consistent framework to combine perturbative and non-perturbative effects in a coherent way and can be applied to obtain an effective description for heavy ion collisions. In particular, it allows us to include nonperturbative effects in existing glasma effective theory and QCD kinetic theory for the weakly coupled saturated degrees of freedom liberated by the collisions in the initial stages in a consistent manner. We argue why the full framework should be able to confront experiments with only a few phenomenological parameters and present feasibility tests for the necessary numerical computations. Furthermore, we discuss that semiholography leads to a new description of collective flow in the form of a generalised non-Newtonian fluid. We discuss some open questions which we hope to answer in the near future.

  9. A Systematic Review Exploring the Social Cognitive Theory of Self-Regulation as a Framework for Chronic Health Condition Interventions.

    Tougas, Michelle E; Hayden, Jill A; McGrath, Patrick J; Huguet, Anna; Rozario, Sharlene

    2015-01-01

    Theory is often recommended as a framework for guiding hypothesized mechanisms of treatment effect. However, there is limited guidance about how to use theory in intervention development. We conducted a systematic review to provide an exemplar review evaluating the extent to which use of theory is identified and incorporated within existing interventions. We searched electronic databases PubMed, PsycINFO, CENTRAL, and EMBASE from inception to May 2014. We searched clinicaltrials.gov for registered protocols, reference lists of relevant systematic reviews and included studies, and conducted a citation search in Web of Science. We included peer-reviewed publications of interventions that referenced the social cognitive theory of self-regulation as a framework for interventions to manage chronic health conditions. Two reviewers independently assessed articles for eligibility. We contacted all authors of included studies for information detailing intervention content. We describe how often theory mechanisms were addressed by interventions, and report intervention characteristics used to address theory. Of 202 articles that reported using the social cognitive theory of self-regulation, 52% failed to incorporate self-monitoring, a main theory component, and were therefore excluded. We included 35 interventions that adequately used the theory framework. Intervention characteristics were often poorly reported in peer-reviewed publications, 21 of 35 interventions incorporated characteristics that addressed each of the main theory components. Each intervention addressed, on average, six of eight self-monitoring mechanisms, two of five self-judgement mechanisms, and one of three self-evaluation mechanisms. The self-monitoring mechanisms 'Feedback' and 'Consistency' were addressed by all interventions, whereas the self-evaluation mechanisms 'Self-incentives' and 'External rewards' were addressed by six and four interventions, respectively. The present review establishes that

  10. Teacher’s Instructional Behaviour in Instructional Management at Elementary School Reviewed from Piaget’s Cognitive Development Theory

    Eni Astuti Ni Putu

    2018-01-01

    This writing aimed at (1) describing the importance of teacher to review instructional management at elementary school based on Piaget’s cognitive development theory; and (2) describing teacher’s instructional behavior in managing instructional at elementary school reviewed from Piaget’s cognitive development theory. In general, Piaget’ cognitive development theory divides children’ cognitive development into four stages. In the elementary school ages of 7 to 11 or 12 years old, Piaget classi...

  11. Two-photon collisions and short-distance tests of quantum chromodynamics

    Brodsky, S.J.

    1978-12-01

    The physics of two-photon collisions in e +- storage rings is reviewed with emphasis on the predictions of perturbative quantum chromodynamics for high transverse momentum reactions. It is noted that because of the remarkable scaling properties predicted by the theory, two-photon collisions may be proved one of the cleanest tests of the quantum chromodynamics picture of short distance hadron dynamics. In order to contrast these predictions for photon-induced reactions with those for incident hadrons, predictions from quantum chromodynamics for hadron structure functions and form factors at large momentum transfer are also discussed. 55 references

  12. The Impact of the Photocopier on Peer Review and Nursing Theory.

    Nicoll, Leslie H

    Two influential publications in nursing, Nursing Research and Perspectives on Nursing Theory, are used to illustrate how a specific technology change-the invention and marketing of the photocopier-influenced knowledge dissemination and information utilization in nursing, perhaps in ways not immediately apparent. Content analysis and historical comparison, using editorials from Nursing Research, historical reports on technology development, and personal reflections on the genesis of Perspectives on Nursing Theory are used to create an argument for the role of technology in peer review, information utilization, and knowledge development in nursing. Multiple forces influence nursing science. Scholars should be alert to data inputs from many sources and respond accordingly.

  13. Explaining Consumer Safe Food Handling Through Behavior-Change Theories: A Systematic Review.

    Young, Ian; Reimer, Danielle; Greig, Judy; Meldrum, Richard; Turgeon, Patricia; Waddell, Lisa

    2017-11-01

    Consumers often engage in unsafe food handling behaviors at home. Previous studies have investigated the ability of behavior-change theories to explain and predict these behaviors. The purpose of this review was to determine which theories are most consistently associated with consumers' safe food handling behaviors across the published literature. A standardized systematic review methodology was used, consisting of the following steps: comprehensive search strategy; relevance screening of identified references; confirmation of relevance and characterization of relevant articles; risk-of-bias assessment; data extraction; and descriptive analysis of study results. A total of 20 relevant studies were identified; they were mostly conducted in Australia (40%) and the United States (35%) and used a cross-sectional design (65%). Most studies targeted young adults (65%), and none focused on high-risk consumer groups. The outcomes of 70% of studies received high overall risk-of-bias ratings, largely due to a lack of control for confounding variables. The most commonly applied theory was the Theory of Planned Behavior (45% of studies), which, along with other investigated theories of behavior change, was frequently associated with consumer safe food handling behavioral intentions and behaviors. However, overall, there was wide variation in the specific constructs found to be significantly associated and in the percentage of variance explained in each outcome across studies. The results suggest that multiple theories of behavior change can help to explain consumer safe food handling behaviors and could be adopted to guide the development of future behavior-change interventions. In these contexts, theories should be appropriately selected and adapted to meet the needs of the specific target population and context of interest.

  14. Recent Fuzzy Generalisations of Rough Sets Theory: A Systematic Review and Methodological Critique of the Literature

    Abbas Mardani

    2017-01-01

    Full Text Available Rough set theory has been used extensively in fields of complexity, cognitive sciences, and artificial intelligence, especially in numerous fields such as expert systems, knowledge discovery, information system, inductive reasoning, intelligent systems, data mining, pattern recognition, decision-making, and machine learning. Rough sets models, which have been recently proposed, are developed applying the different fuzzy generalisations. Currently, there is not a systematic literature review and classification of these new generalisations about rough set models. Therefore, in this review study, the attempt is made to provide a comprehensive systematic review of methodologies and applications of recent generalisations discussed in the area of fuzzy-rough set theory. On this subject, the Web of Science database has been chosen to select the relevant papers. Accordingly, the systematic and meta-analysis approach, which is called “PRISMA,” has been proposed and the selected articles were classified based on the author and year of publication, author nationalities, application field, type of study, study category, study contribution, and journal in which the articles have appeared. Based on the results of this review, we found that there are many challenging issues related to the different application area of fuzzy-rough set theory which can motivate future research studies.

  15. Galaxy collisions

    Combes, F.

    1987-01-01

    Galaxies are not isolated systems of stars and gas, ''independent universes'' as believed by astronomers about ten years ago, but galaxies are formed and evolve by interaction with their environment, and in particular with their nearest neighbors. Gravitational interactions produce enormous tides in the disk of spiral galaxies, generate spiral arms and trigger bursts of star formation. Around elliptical galaxies, the collision with a small companion produces a series of waves, or shells. A galaxy interaction leads, in most cases, to the coalescence of the two coliders; therefore all galaxies are not formed just after the Big-Bang, when matter recombines: second generation galaxies are still forming now by galaxy mergers, essentially elliptical galaxies, but also compact dwarfs. Collisions between galaxies could also trigger activity in nuclei for radiogalaxies and quasars [fr

  16. Quarkonium production in hadronic collisions

    Gavai, R.; Schuler, G.A.; Sridhar, K.

    1995-01-01

    We summarize the theoretical description of charmonium and bottonium production in hadronic collisions and compare it to the available data from hadron-nucleon interactions. With the parameters of the theory established by these data, we obtain predictions for quarkonium production at RHIC and LHC energies

  17. Developing and Optimising the Use of Logic Models in Systematic Reviews: Exploring Practice and Good Practice in the Use of Programme Theory in Reviews.

    Kneale, Dylan; Thomas, James; Harris, Katherine

    2015-01-01

    Logic models are becoming an increasingly common feature of systematic reviews, as is the use of programme theory more generally in systematic reviewing. Logic models offer a framework to help reviewers to 'think' conceptually at various points during the review, and can be a useful tool in defining study inclusion and exclusion criteria, guiding the search strategy, identifying relevant outcomes, identifying mediating and moderating factors, and communicating review findings. In this paper we critique the use of logic models in systematic reviews and protocols drawn from two databases representing reviews of health interventions and international development interventions. Programme theory featured only in a minority of the reviews and protocols included. Despite drawing from different disciplinary traditions, reviews and protocols from both sources shared several limitations in their use of logic models and theories of change, and these were used almost unanimously to solely depict pictorially the way in which the intervention worked. Logic models and theories of change were consequently rarely used to communicate the findings of the review. Logic models have the potential to be an aid integral throughout the systematic reviewing process. The absence of good practice around their use and development may be one reason for the apparent limited utility of logic models in many existing systematic reviews. These concerns are addressed in the second half of this paper, where we offer a set of principles in the use of logic models and an example of how we constructed a logic model for a review of school-based asthma interventions.

  18. Collision-produced atomic states

    Andersen, N.; Copenhagen Univ.

    1988-01-01

    The last 10-15 years have witnessed the development of a new, powerful class of experimental techniques for atomic collision studies, allowing partial or complete determination of the state of the atoms after a collision event, i.e. the full set of quantum-mechanical scattering amplitudes or - more generally - the density matrix describing the system. Evidently, such studies, involving determination of alignment and orientation parameters, provide much more severe tests of state-of-the-art scattering theories than do total or differential cross section measurements which depend on diagonal elements of the density matrix. The off-diagonal elements give us detailed information about the shape and dynamics of the atomic states. Therefore, close studies of collision-produced atomic states are currently leading to deeper insights into the fundamental physical mechanisms governing the dynamics of atomic collision events. The first part of the lectures deals with the language used to describe atomic states, while the second part presents a selection of recent results for model systems which display fundamental aspects of the collision physics in particularly instructive ways. I shall here restrict myself to atom-atom collisions. The discussion will be focused on states decaying by photon emission though most of the ideas can be easily modified to include electron emission as well. (orig./AH)

  19. Electrocatalysis of borohydride oxidation: a review of density functional theory approach combined with experimental validation

    Sison Escaño, Mary Clare; Arevalo, Ryan Lacdao; Kasai, Hideaki; Gyenge, Elod

    2014-01-01

    The electrocatalysis of borohydride oxidation is a complex, up-to-eight-electron transfer process, which is essential for development of efficient direct borohydride fuel cells. Here we review the progress achieved by density functional theory (DFT) calculations in explaining the adsorption of BH 4 − on various catalyst surfaces, with implications for electrocatalyst screening and selection. Wherever possible, we correlate the theoretical predictions with experimental findings, in order to validate the proposed models and to identify potential directions for further advancements. (topical review)

  20. Electrocatalysis of borohydride oxidation: a review of density functional theory approach combined with experimental validation

    Sison Escaño, Mary Clare; Lacdao Arevalo, Ryan; Gyenge, Elod; Kasai, Hideaki

    2014-09-01

    The electrocatalysis of borohydride oxidation is a complex, up-to-eight-electron transfer process, which is essential for development of efficient direct borohydride fuel cells. Here we review the progress achieved by density functional theory (DFT) calculations in explaining the adsorption of BH4- on various catalyst surfaces, with implications for electrocatalyst screening and selection. Wherever possible, we correlate the theoretical predictions with experimental findings, in order to validate the proposed models and to identify potential directions for further advancements.

  1. The theory of planned behaviour and discrete food choices: a systematic review and meta-analysis

    McDermott, M?irt?n S.; Oliver, Madalyn; Svenson, Alexander; Simnadis, Thomas; Beck, Eleanor J.; Coltman, Tim; Iverson, Don; Caputi, Peter; Sharma, Rajeev

    2015-01-01

    The combination of economic and social costs associated with non-communicable diseases provide a compelling argument for developing strategies that can influence modifiable risk factors, such as discrete food choices. Models of behaviour, such as the Theory of Planned Behaviour (TPB) provide conceptual order that allows program designers and policy makers to identify the substantive elements that drive behaviour and design effective interventions. The primary aim of the current review was to ...

  2. Theoretical explanations for maintenance of behaviour change: a systematic review of behaviour theories

    Kwasnicka, Dominika; Dombrowski, Stephan U; White, Martin; Sniehotta, Falko

    2016-01-01

    ABSTRACT Background: Behaviour change interventions are effective in supporting individuals in achieving temporary behaviour change. Behaviour change maintenance, however, is rarely attained. The aim of this review was to identify and synthesise current theoretical explanations for behaviour change maintenance to inform future research and practice. Methods: Potentially relevant theories were identified through systematic searches of electronic databases (Ovid MEDLINE, Embase, PsycINFO). In a...

  3. A REVIEW OF FINANCE–GROWTH NEXUS THEORIES: HOW DOES DEVELOPMENT FINANCE FITS IN?

    MARWA Nyankomo; ZHANJE Stephen

    2015-01-01

    The finance growth-nexus debates have been contentious over the past three decades both empirically and theoretically. To contribute to this debate, the current paper presents a concise review of finance-growths nexus theoretical development and the current debate around growth-finance nexus theories. Then, it extends the current theoretical debate to include development finance within the broader scheme of finance-growth discourse. The key emerging trend is that, most of the contemporary the...

  4. A review of the evidence linking adult attachment theory and chronic pain: presenting a conceptual model.

    Meredith, Pamela; Ownsworth, Tamara; Strong, Jenny

    2008-03-01

    It is now well established that pain is a multidimensional phenomenon, affected by a gamut of psychosocial and biological variables. According to diathesis-stress models of chronic pain, some individuals are more vulnerable to developing disability following acute pain because they possess particular psychosocial vulnerabilities which interact with physical pathology to impact negatively upon outcome. Attachment theory, a theory of social and personality development, has been proposed as a comprehensive developmental model of pain, implicating individual adult attachment pattern in the ontogenesis and maintenance of chronic pain. The present paper reviews and critically appraises studies which link adult attachment theory with chronic pain. Together, these papers offer support for the role of insecure attachment as a diathesis (or vulnerability) for problematic adjustment to pain. The Attachment-Diathesis Model of Chronic Pain developed from this body of literature, combines adult attachment theory with the diathesis-stress approach to chronic pain. The evidence presented in this review, and the associated model, advances our understanding of the developmental origins of chronic pain conditions, with potential application in guiding early pain intervention and prevention efforts, as well as tailoring interventions to suit specific patient needs.

  5. Models and theories of prescribing decisions: A review and suggested a new model.

    Murshid, Mohsen Ali; Mohaidin, Zurina

    2017-01-01

    To date, research on the prescribing decisions of physician lacks sound theoretical foundations. In fact, drug prescribing by doctors is a complex phenomenon influenced by various factors. Most of the existing studies in the area of drug prescription explain the process of decision-making by physicians via the exploratory approach rather than theoretical. Therefore, this review is an attempt to suggest a value conceptual model that explains the theoretical linkages existing between marketing efforts, patient and pharmacist and physician decision to prescribe the drugs. The paper follows an inclusive review approach and applies the previous theoretical models of prescribing behaviour to identify the relational factors. More specifically, the report identifies and uses several valuable perspectives such as the 'persuasion theory - elaboration likelihood model', the stimuli-response marketing model', the 'agency theory', the theory of planned behaviour,' and 'social power theory,' in developing an innovative conceptual paradigm. Based on the combination of existing methods and previous models, this paper suggests a new conceptual model of the physician decision-making process. This unique model has the potential for use in further research.

  6. Reactive Collision Avoidance Algorithm

    Scharf, Daniel; Acikmese, Behcet; Ploen, Scott; Hadaegh, Fred

    2010-01-01

    The reactive collision avoidance (RCA) algorithm allows a spacecraft to find a fuel-optimal trajectory for avoiding an arbitrary number of colliding spacecraft in real time while accounting for acceleration limits. In addition to spacecraft, the technology can be used for vehicles that can accelerate in any direction, such as helicopters and submersibles. In contrast to existing, passive algorithms that simultaneously design trajectories for a cluster of vehicles working to achieve a common goal, RCA is implemented onboard spacecraft only when an imminent collision is detected, and then plans a collision avoidance maneuver for only that host vehicle, thus preventing a collision in an off-nominal situation for which passive algorithms cannot. An example scenario for such a situation might be when a spacecraft in the cluster is approaching another one, but enters safe mode and begins to drift. Functionally, the RCA detects colliding spacecraft, plans an evasion trajectory by solving the Evasion Trajectory Problem (ETP), and then recovers after the collision is avoided. A direct optimization approach was used to develop the algorithm so it can run in real time. In this innovation, a parameterized class of avoidance trajectories is specified, and then the optimal trajectory is found by searching over the parameters. The class of trajectories is selected as bang-off-bang as motivated by optimal control theory. That is, an avoiding spacecraft first applies full acceleration in a constant direction, then coasts, and finally applies full acceleration to stop. The parameter optimization problem can be solved offline and stored as a look-up table of values. Using a look-up table allows the algorithm to run in real time. Given a colliding spacecraft, the properties of the collision geometry serve as indices of the look-up table that gives the optimal trajectory. For multiple colliding spacecraft, the set of trajectories that avoid all spacecraft is rapidly searched on

  7. Theory based interventions for caries related sugar intake in adults: systematic review.

    Al Rawahi, Said Hartih; Asimakopoulou, Koula; Newton, Jonathon Timothy

    2017-07-25

    Theories of behavior change are essential in the design of effective behaviour change strategies. No studies have assessed the effectiveness of interventions based on psychological theories to reduce sugar intake related to dental caries. The study assessed the effect of interventions based on Social Congition Models (SCMs) on sugar intake in adults, when compared with educational interventions or no intervention. A range of papers were considered: Systematic review Systematic Reviews with or without Meta Analyses; Randomised Controlled Trials; Controlled Clinical Trials and Before and after studies, of interventions based on Social Cognition Models aimed at dietary intake of sugar in adults. The Cochrane database including: Oral Health Group's Trials Register (2015), MEDLINE (from 1966 to September 2015), EMBASE (from 1980 to September 2015), PsycINFO (from 1966 to September 2015) were searched. No article met the full eligibility criteria for the current systematic review so no articles were included. There is a need for more clinical trials to assess the effectiveness of interventions based on psychological theory in reducing dietary sugar intake among adults. PROSPERO: CRD42015026357 .

  8. Relativistic Chiral Kinetic Theory

    Stephanov, Mikhail

    2016-01-01

    This very brief review of the recent progress in chiral kinetic theory is based on the results of Refs. [J.-Y. Chen, D. T. Son, M. A. Stephanov, H.-U. Yee, Y. Yin, Lorentz Invariance in Chiral Kinetic Theory, Phys. Rev. Lett. 113 (18) (2014) 182302. doi: (10.1103/PhysRevLett.113.182302); J.-Y. Chen, D. T. Son, M. A. Stephanov, Collisions in Chiral Kinetic Theory, Phys. Rev. Lett. 115 (2) (2015) 021601. doi: (10.1103/PhysRevLett.115.021601); M. A. Stephanov, H.-U. Yee, The no-drag frame for anomalous chiral fluid, Phys. Rev. Lett. 116 (12) (2016) 122302. doi: (10.1103/PhysRevLett.116.122302)].

  9. Relativistic Chiral Kinetic Theory

    Stephanov, Mikhail

    2016-12-15

    This very brief review of the recent progress in chiral kinetic theory is based on the results of Refs. [J.-Y. Chen, D. T. Son, M. A. Stephanov, H.-U. Yee, Y. Yin, Lorentz Invariance in Chiral Kinetic Theory, Phys. Rev. Lett. 113 (18) (2014) 182302. doi: (10.1103/PhysRevLett.113.182302); J.-Y. Chen, D. T. Son, M. A. Stephanov, Collisions in Chiral Kinetic Theory, Phys. Rev. Lett. 115 (2) (2015) 021601. doi: (10.1103/PhysRevLett.115.021601); M. A. Stephanov, H.-U. Yee, The no-drag frame for anomalous chiral fluid, Phys. Rev. Lett. 116 (12) (2016) 122302. doi: (10.1103/PhysRevLett.116.122302)].

  10. A Critical Review of the Literature on Firm-Level Theories on Ship Investment

    Sinem Celik Girgin

    2018-01-01

    Full Text Available The maritime industry is one of those rare industries that are both highly international integrated to international trade and also highly capital intensive dependent on substantial investment amount. In the literature, ship investments have not been widely examined through the firm-level investment theories to explore the link between investment level and asset price valuation. The general trend in the literature of ship investments is to analyse the relationship among the shipping markets (newbuilding, second-hand, freight rate and scrap and their impact on asset price valuation, the timing of investments and market entry and exit conditions. In this paper, we extensively reviewed the literature of firm-level investment theories and ship investments. We showed that the application of firm-level investment theories to the ship investments is confined to the basic investment valuation models, such as Net Present Value and Real Option Analysis. Ship investments need to be examined by firm-level investment theories to define firm/industry value maximization level within the approach of the solid investment theories.

  11. Organizational Health Literacy: Review of Theories, Frameworks, Guides, and Implementation Issues

    Bonneville, Luc; Bouchard, Louise

    2018-01-01

    Organizational health literacy is described as an organization-wide effort to transform organization and delivery of care and services to make it easier for people to navigate, understand, and use information and services to take care of their health. Several health literacy guides have been developed to assist healthcare organizations with this effort, but their content has not been systematically reviewed to understand the scope and practical implications of this transformation. The objective of this study was to review (1) theories and frameworks that inform the concept of organizational health literacy, (2) the attributes of organizational health literacy as described in the guides, (3) the evidence for the effectiveness of the guides, and (4) the barriers and facilitators to implementing organizational health literacy. Drawing on a metanarrative review method, 48 publications were reviewed, of which 15 dealt with the theories and operational frameworks, 20 presented health literacy guides, and 13 addressed guided implementation of organizational health literacy. Seven theories and 9 operational frameworks have been identified. Six health literacy dimensions and 9 quality-improvement characteristics were reviewed for each health literacy guide. Evidence about the effectiveness of health literacy guides is limited at this time, but experiences with the guides were positive. Thirteen key barriers (conceived also as facilitators) were identified. Further development of organizational health literacy requires a strong and a clear connection between its vision and operationalization as an implementation strategy to patient-centered care. For many organizations, becoming health literate will require multiple, simultaneous, and radical changes. Organizational health literacy has to make sense from clinical and financial perspectives in order for organizations to embark on such transformative journey. PMID:29569968

  12. Organizational Health Literacy: Review of Theories, Frameworks, Guides, and Implementation Issues.

    Farmanova, Elina; Bonneville, Luc; Bouchard, Louise

    2018-01-01

    Organizational health literacy is described as an organization-wide effort to transform organization and delivery of care and services to make it easier for people to navigate, understand, and use information and services to take care of their health. Several health literacy guides have been developed to assist healthcare organizations with this effort, but their content has not been systematically reviewed to understand the scope and practical implications of this transformation. The objective of this study was to review (1) theories and frameworks that inform the concept of organizational health literacy, (2) the attributes of organizational health literacy as described in the guides, (3) the evidence for the effectiveness of the guides, and (4) the barriers and facilitators to implementing organizational health literacy. Drawing on a metanarrative review method, 48 publications were reviewed, of which 15 dealt with the theories and operational frameworks, 20 presented health literacy guides, and 13 addressed guided implementation of organizational health literacy. Seven theories and 9 operational frameworks have been identified. Six health literacy dimensions and 9 quality-improvement characteristics were reviewed for each health literacy guide. Evidence about the effectiveness of health literacy guides is limited at this time, but experiences with the guides were positive. Thirteen key barriers (conceived also as facilitators) were identified. Further development of organizational health literacy requires a strong and a clear connection between its vision and operationalization as an implementation strategy to patient-centered care. For many organizations, becoming health literate will require multiple, simultaneous, and radical changes. Organizational health literacy has to make sense from clinical and financial perspectives in order for organizations to embark on such transformative journey.

  13. Baryon production in proton-proton collisions

    Liu, F.M.; Werner, K.

    2002-01-01

    Motivated by the recent rapidity spectra of baryons and antibaryons in pp collisions at 158 GeV and the Ω-bar/Ω ratio discussion, we reviewed string formation mechanism and some string models. This investigation told us how color strings are formed in ultrarelativistic proton-proton collisions

  14. Successive combination jet algorithm for hadron collisions

    Ellis, S.D.; Soper, D.E.

    1993-01-01

    Jet finding algorithms, as they are used in e + e- and hadron collisions, are reviewed and compared. It is suggested that a successive combination style algorithm, similar to that used in e + e- physics, might be useful also in hadron collisions, where cone style algorithms have been used previously

  15. Laser-assisted electron-atom collisions

    Mason, N.J.

    1989-01-01

    New developments in our understanding of the electron-atom collision process have been made possible by combining the use of highly monochromatic electron beams and intense CO 2 lasers. This paper reviews such experiments and discusses possible future progress in what is a new field in atomic collision physics. (author)

  16. Nuclear suppression in p-A collisions from induced radiation

    Arleo, F.; Kolevatov, R.; Peigne, S.; Sami, T.

    2016-01-01

    The current status of coherent energy loss is reviewed, both in theory and in its phenomenological applications to p-A collisions. The induced energy loss is not bounded in general, but only in the specific situation where the energetic parton is suddenly accelerated (as in deep inelastic scattering) in the nuclear medium. In the situation where the parton is asymptotic, i.e. 'prepared' at t = -∞ and 'tagged' at t = +∞ after crossing a nuclear medium of thickness L (a situation relevant to forward hadron production in p-A collisions), ΔE appears to be proportional to E. Both situations are detailed in the article

  17. A review of the findings and theories on surface size effects on visual attention.

    Peschel, Anne O; Orquin, Jacob L

    2013-12-09

    That surface size has an impact on attention has been well-known in advertising research for almost a century; however, theoretical accounts of this effect have been sparse. To address this issue, we review studies on surface size effects on eye movements in this paper. While most studies find that large objects are more likely to be fixated, receive more fixations, and are fixated faster than small objects, a comprehensive explanation of this effect is still lacking. To bridge the theoretical gap, we relate the findings from this review to three theories of surface size effects suggested in the literature: a linear model based on the assumption of random fixations (Lohse, 1997), a theory of surface size as visual saliency (Pieters etal., 2007), and a theory based on competition for attention (CA; Janiszewski, 1998). We furthermore suggest a fourth model - demand for attention - which we derive from the theory of CA by revising the underlying model assumptions. In order to test the models against each other, we reanalyze data from an eye tracking study investigating surface size and saliency effects on attention. The reanalysis revealed little support for the first three theories while the demand for attention model showed a much better alignment with the data. We conclude that surface size effects may best be explained as an increase in object signal strength which depends on object size, number of objects in the visual scene, and object distance to the center of the scene. Our findings suggest that advertisers should take into account how objects in the visual scene interact in order to optimize attention to, for instance, brands and logos.

  18. A review of the decoherent histories approach to the arrival time problem in quantum theory

    Yearsley, James M

    2011-01-01

    We review recent progress in understanding the arrival time problem in quantum mechanics, from the point of view of the decoherent histories approach to quantum theory. We begin by discussing the arrival time problem, focussing in particular on the role of the probability current in the expected classical solution. After a brief introduction to decoherent histories we review the use of complex potentials in the construction of appropriate class operators. We then discuss the arrival time problem for a particle coupled to an environment, and review how the arrival time probability can be expressed in terms of a POVM in this case. We turn finally to the question of decoherence of the corresponding histories, and we show that this can be achieved for simple states in the case of a free particle, and for general states for a particle coupled to an environment.

  19. Theory of reasoned action and theory of planned behavior-based dietary interventions in adolescents and young adults: a systematic review

    Hackman CL; Knowlden AP

    2014-01-01

    Christine L Hackman, Adam P KnowldenDepartment of Health Science, The University of Alabama, Tuscaloosa, AL, USABackground: Childhood obesity has reached epidemic proportions in many nations around the world. The theory of planned behavior (TPB) and the theory of reasoned action (TRA) have been used to successfully plan and evaluate numerous interventions for many different behaviors. The aim of this study was to systematically review and synthesize TPB and TRA-based dietary behavior interven...

  20. The predictive capacity of the theory of reasoned action and the theory of planned behavior in exercise research: an integrated literature review.

    Blue, C L

    1995-04-01

    Although the association between habitual exercise and health benefits has been well documented, physical activity levels in the United States are lower than is necessary to reach the nation's health potential. Beliefs that people hold can be a motivating factor in engaging in exercise. A critical review of the literature was conducted to assess the efficacy of using the Theory of Reasoned Action and the Theory of Planned Behavior with respect to exercise. Evidence for the predictive utility of the theories was found. The Theory of Planned Behavior is a more promising framework for the study of exercise because it includes beliefs about control of factors that would facilitate or inhibit carrying out exercise. Strategies for use of the theories in planning exercise programs are provided and suggestions for future research discussed.

  1. Use of programme theory to understand the differential effects of interventions across socio-economic groups in systematic reviews-a systematic methodology review.

    Maden, Michelle; Cunliffe, Alex; McMahon, Naoimh; Booth, Andrew; Carey, Gina Michelle; Paisley, Suzy; Dickson, Rumona; Gabbay, Mark

    2017-12-29

    Systematic review guidance recommends the use of programme theory to inform considerations of if and how healthcare interventions may work differently across socio-economic status (SES) groups. This study aimed to address the lack of detail on how reviewers operationalise this in practice. A methodological systematic review was undertaken to assess if, how and the extent to which systematic reviewers operationalise the guidance on the use of programme theory in considerations of socio-economic inequalities in health. Multiple databases were searched from January 2013 to May 2016. Studies were included if they were systematic reviews assessing the effectiveness of an intervention and included data on SES. Two reviewers independently screened all studies, undertook quality assessment and extracted data. A narrative approach to synthesis was adopted. A total of 37 systematic reviews were included, 10 of which were explicit in the use of terminology for 'programme theory'. Twenty-nine studies used programme theory to inform both their a priori assumptions and explain their review findings. Of these, 22 incorporated considerations of both what and how interventions do/do not work in SES groups to both predict and explain their review findings. Thirteen studies acknowledged 24 unique theoretical references to support their assumptions of what or how interventions may have different effects in SES groups. Most reviewers used supplementary evidence to support their considerations of differential effectiveness. The majority of authors outlined a programme theory in the "Introduction" and "Discussion" sections of the review to inform their assumptions or provide explanations of what or how interventions may result in differential effects within or across SES groups. About a third of reviews used programme theory to inform the review analysis and/or synthesis. Few authors used programme theory to inform their inclusion criteria, data extraction or quality assessment. Twenty

  2. Implications of Theory and Research on Strategic Leadership: A Critical Review

    Carlos Roberto Banzato

    2016-10-01

    Full Text Available Strategic Leadership: Theory and Research on Executives, Top Management Teams, and Boards by Finkelstein, Hambrick and Canella Jr. (2009 is one of the most important references in strategy studies. This work is a critical review of this book and attempts to answer why organizations do what they do or play the way they play. In this paper, we review all eleven chapters that make up the book. We then suggest the implications of this theory on strategy and organizations. We also consider how this book affects the development of the field of study. The book offers considerable foundations for executives and serves as a reference for researchers who wish to understand the phenomenon related to strategic leadership, considering the CEO, Board and Top Management Team.  The major contribution of this paper is that it summarizes the theory and concepts of the book in a few pages and identifies the main characteristics, antecedents and consequences of leadership in organizations. 

  3. Models and theories of prescribing decisions: A review and suggested a new model

    Mohaidin, Zurina

    2017-01-01

    To date, research on the prescribing decisions of physician lacks sound theoretical foundations. In fact, drug prescribing by doctors is a complex phenomenon influenced by various factors. Most of the existing studies in the area of drug prescription explain the process of decision-making by physicians via the exploratory approach rather than theoretical. Therefore, this review is an attempt to suggest a value conceptual model that explains the theoretical linkages existing between marketing efforts, patient and pharmacist and physician decision to prescribe the drugs. The paper follows an inclusive review approach and applies the previous theoretical models of prescribing behaviour to identify the relational factors. More specifically, the report identifies and uses several valuable perspectives such as the ‘persuasion theory - elaboration likelihood model’, the stimuli–response marketing model’, the ‘agency theory’, the theory of planned behaviour,’ and ‘social power theory,’ in developing an innovative conceptual paradigm. Based on the combination of existing methods and previous models, this paper suggests a new conceptual model of the physician decision-making process. This unique model has the potential for use in further research. PMID:28690701

  4. A critical review of theories to explain violent relationship termination: implications for research and intervention.

    Rhatigan, Deborah L; Street, Amy E; Axsom, Danny K

    2006-05-01

    The following review represents an update and extension to an influential article (see [Strube, M.J. (1988). The decision to leave an abusive relationship: Empirical evidence and theoretical issues. Psychological Bulletin, 104, 236-250.]), which evaluated empirical research and suggested potential theories to explain victimized women's decisions to terminate violent relationships. In contrast to the original review, this paper provides information on the importance of and means by which theory should be evaluated and critically determines which theoretical approach(es) might be most productive based on theoretical and atheoretical evidence. In addition, this paper discusses strengths and weaknesses of each approach, in light of certain criteria deemed to be important for the evaluation of theory (e.g., comprehensiveness, parsimony, etc.). Furthermore, this paper discusses current controversies regarding these issues, ramifications of differing theoretical approaches, and their potential impact on the field. Based on this analysis, it is determined that general approaches (e.g., reasoned action/planned behavior, investment model) may be better for understanding this complex and multifaceted decision. Suggestions for future theoretical and intervention research are discussed.

  5. Models and theories of prescribing decisions: A review and suggested a new model

    Ali Murshid M

    2017-06-01

    Full Text Available To date, research on the prescribing decisions of physician lacks sound theoretical foundations. In fact, drug prescribing by doctors is a complex phenomenon influenced by various factors. Most of the existing studies in the area of drug prescription explain the process of decision-making by physicians via the exploratory approach rather than theoretical. Therefore, this review is an attempt to suggest a value conceptual model that explains the theoretical linkages existing between marketing efforts, patient and pharmacist and physician decision to prescribe the drugs. The paper follows an inclusive review approach and applies the previous theoretical models of prescribing behaviour to identify the relational factors. More specifically, the report identifies and uses several valuable perspectives such as the ‘persuasion theory - elaboration likelihood model’, the stimuli–response marketing model’, the ‘agency theory’, the theory of planned behaviour,’ and ‘social power theory,’ in developing an innovative conceptual paradigm. Based on the combination of existing methods and previous models, this paper suggests a new conceptual model of the physician decision-making process. This unique model has the potential for use in further research.

  6. Development of a program theory for shared decision-making: a realist review protocol.

    Groot, Gary; Waldron, Tamara; Carr, Tracey; McMullen, Linda; Bandura, Lori-Ann; Neufeld, Shelley-May; Duncan, Vicky

    2017-06-17

    The practicality of applying evidence to healthcare systems with the aim of implementing change is an ongoing challenge for practitioners, policy makers, and academics. Shared decision- making (SDM), a method of medical decision-making that allows a balanced relationship between patients, physicians, and other key players in the medical decision process, is purported to improve patient and system outcomes. Despite the oft-mentioned benefits, there are gaps in the current literature between theory and implementation that would benefit from a realist approach given the value of this methodology to analyze complex interventions. In this protocol, we outline a study that will explore: "In which situations, how, why, and for whom does SDM between patients and health care providers contribute to improved decision making?" A seven step iterative process will be described including preliminary theory development, establishment of a search strategy, selection and appraisal of literature, data extraction, analysis and synthesis of extracted results from literature, and formation of a revised program theory with the input of patients, physicians, nurse navigators, and policy makers from a stakeholder session. The goal of the realist review will be to identify and refine a program theory for SDM through the identification of mechanisms which shape the characteristics of when, how, and why SDM will, and will not, work. PROSPERO CRD42017062609.

  7. A review of constructivism: understanding and using a relatively new theory.

    Whitman, N

    1993-09-01

    The purpose of this review paper is to familiarize family medicine educators with a relatively new educational theory, "constructivism." This theory is derived from the philosophical proposition that reality is constructed by the individual. According to the more traditional theory of "objectivism," knowledge exists in the world external to personal experience. Constructivist theory postulates that personal experience cannot be separated from knowledge. In analyzing the literature, the author found that constructivism can be viewed at the cognitive (individual) and social (community) levels. Cognitive constructivism maintains that individuals develop their own models of reality using personal experience and research-based data. Two key elements of cognitive constructivism with implications for family medicine educators are promoting student independence and active learning. Social constructivism maintains that individuals use their membership in a community to continually refine and shape their models of reality. By communicating with each other (for physicians, in the "conversation of medicine"), we test our constructs. Two key elements of social constructivism with implications for application by family medicine educators are promoting collaboration and peer teaching.

  8. Social psychological theories of disordered eating in college women: review and integration.

    Fitzsimmons-Craft, Ellen E

    2011-11-01

    Because peer interaction, weight/shape, and self-concept formation are particularly salient to college women, the implications of social psychological theories may be especially far-reaching during the college years. College women may be particularly vulnerable to the effects of social comparison, objectification, and uses and gratifications theories, which describe social-cognitive mechanisms that provide an individual with information regarding her own view of her body and how she perceives that others perceive her body. The current paper will review and integrate findings related to these three theories of disordered eating in college women in an effort to present a more comprehensive understanding of the social psychological mechanisms that play a role in the development and maintenance of such pathology for this group of young women. Limitations of and future directions for research on these theories will be discussed, as will their potential integration with other factors that contribute to disordered eating and implications for treatment and prevention. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. A review of attachment theory in the context of adolescent parenting.

    Flaherty, Serena Cherry; Sadler, Lois S

    2011-01-01

    The purpose of this article is to review attachment theory and relate the attachment perspective to adolescent mothers and their children. Attachment theory explains positive maternal-infant attachment as a dyadic relationship between the infant and mother that provides the infant with a secure base from which to explore the world. With respect to cognitive, social, and behavioral domains, securely attached infants tend to have more favorable long-term outcomes, while insecurely attached infants are more likely to have adverse outcomes. Adolescent parenthood can disrupt normal adolescent development, and this disruption influences development of the emotional and cognitive capacities necessary for maternal behaviors that foster secure attachment. However, it appears that if specialized supports are in place to facilitate the process of developing attachment, infants of adolescent mothers can obtain higher rates of secure attachment than normative samples in this population. Copyright © 2011 National Association of Pediatric Nurse Practitioners. Published by Mosby, Inc. All rights reserved.

  10. Beyond Depression? A Review of the Optimal Foraging Theory Literature in Zooarchaeology and Archaeobotany

    Emily Lena Jones

    2017-04-01

    Full Text Available The use of optimal foraging theory in archaeology has been criticized for focusing heavily on “negative” human-environmental interactions, particularly anthropogenic resource depression, in which prey populations are reduced by foragers’ own foraging activities. In addition, some researchers have suggested the focus on resource depression is more common in the zooarchaeological literature than in the archaeobotanical literature, indicating fundamental differences in the ways zooarchaeologists and archaeobotanists approach the archaeological record. In this paper, we assess these critiques through a review of the literature between 1997 and 2017. We find that studies identifying resource depression occur at similar rates in the archaeobotanical and zooarchaeological literature. In addition, while earlier archaeological applications of optimal foraging theory did focus heavily on the identification of resource depression, the literature published between 2013 and 2017 shows a wider variety of approaches.

  11. Teaching and learning theories, and teaching methods used in postgraduate education in the health sciences: a systematic review protocol.

    McInerney, Patricia A; Green-Thompson, Lionel P

    2017-04-01

    The objective of this scoping review is to determine the theories of teaching and learning, and/or models and/or methods used in teaching in postgraduate education in the health sciences. The longer term objective is to use the information gathered to design a workshop for teachers of postgraduate students.The question that this review seeks to answer is: what theories of teaching and learning, and/or models and/or methods of teaching are used in postgraduate teaching?

  12. Ship Collision and Grounding Analysis

    Pedersen, Preben Terndrup

    2010-01-01

    It is the purpose of the paper to present a review of prediction and analysis tools for collision and grounding analyses and to outline a probabilistic procedure whereby these tools can be used by the maritime industry to develop performance based rules to reduce the risk associated with human, e...

  13. Comments about anti-pp collisions

    Jung, M.

    1978-01-01

    A review concerning specific properties of anti-pp collisions has been done through the summary of several theoretical and experimental papers. Some new experimental measurements are suggested towards the analysis of different already known hadronic processes

  14. Resonance formation in photon-photon collisions

    Gidal, G.

    1988-08-01

    Recent experimental progress on resonance formation in photon-photon collisions is reviewed with particular emphasis on the pseudoscalar and tensor nonents and on the γγ* production of spin-one resonances. 37 refs., 17 figs., 5 tabs

  15. Phenomenological approaches of dissipative heavy ion collisions

    Ngo, C.

    1983-09-01

    These lectures describe the properties of dissipative heavy ion collisions observed in low bombarding energy heavy ion reactions. These dissipative collisions are of two different types: fusion and deep inelastic reactions. Their main experimental properties are described on selected examples. It is shown how it is possible to give a simple interpretation to the data. A large number of phenomenological models have been developped to understand dissipative heavy ion collisions. The most important are those describing the collision by classical mechanics and friction forces, the diffusion models, and transport theories which merge both preceding approaches. A special emphasis has been done on two phenomena observed in dissipative heavy ion collisions: charge equilibratium for which we can show the existence of quantum fluctuations, and fast fission which appears as an intermediate mechanism between deep inelastic reactions and compound nucleus formation [fr

  16. A critical review on some aspects of the theory of fission

    Pauli, H.C.

    1981-01-01

    The lecture notes display briefly some of the facets which eventually will be part of a theory for the fission process. They cover some important aspects of our present understanding in a qualitative fashion and complement the existing review articles rather than replacing them. The notes include sections on (I) The Bohr-Wheeler Fission of a Drop, (II) The Strutinsky-Swiatecki Quantum Droplet, (III) The Question of Inertias of a Fluid in Motion, (IV) Some Selected Aspects of the Distributions of Mass and Kinetic Energy, and (V) Possible Relations Between the Phenomenological Models and Self-Consistent Field Approximations. (author)

  17. Deaths during apprehensions of agitated persons. A review of proposed pathophysiological theories

    Tamsen Fredrik

    2014-06-01

    Full Text Available The pathophysiology of sudden death during apprehension remains largely unclear. The most frequently discussed mechanisms are excited delirium, positional asphyxia, metabolic acidosis, acute and chronic drug abuse, and autonomic instability. As in most areas of forensic medicine, much of the knowledge comes from case reports, which are of little use in understanding causality. Experimental studies of some aspects have been performed, and they show somewhat divergent results and interpretations. The aim of this review is to summarize the different proposed theories, and to point out important issues for further research.

  18. Sirenomelia: a review of embryogenic theories and discussion of the differences from caudal regression syndrome.

    Isik Kaygusuz, Ecmel; Kurek Eken, Meryem; Sivrikoz, Oya Nermin; Cetiner, Handan

    2016-03-01

    To discuss the pathological features of sirenomelia in the light of our 10 cases and review the current theories. We identified 10 patients with sirenomelia from our hospital database. All clinical details and the autopsy features of 10 cases were noted. Of the 10 children with sirenomelia seven had bilateral renal agenesis, three had bladder agenesis and one had a renal hypoplasia. Single umbilical artery was found in 60% of children with sirenomelia. External genitalia was ambiguous in seven of 10 patients. Even though the etiology of caudal regression syndrome (CRS) and sirenomelia remains unknown we tend to believe that sirenomelia and CRS might be different entities.

  19. Protection motivation theory and physical activity in the general population: a systematic literature review.

    Bui, Linh; Mullan, Barbara; McCaffery, Kirsten

    2013-01-01

    An appropriate theoretical framework may be useful for guiding the development of physical activity interventions. This review investigates the effectiveness of the protection motivation theory (PMT), a model based on the cognitive mediation processes of behavioral change, in the prediction and promotion of physical activity participation. A literature search was conducted using the databases MEDLINE, PsycINFO, PubMed, and Web of Science, and a manual search was conducted on relevant reference lists. Studies were included if they tested or applied the PMT, measured physical activity, and sampled from healthy populations. A total of 20 studies were reviewed, grouped into four design categories: prediction, stage discrimination, experimental manipulation, and intervention. The results indicated that the PMT's coping appraisal construct of self-efficacy generally appears to be the most effective in predicting and promoting physical activity participation. In conclusion, the PMT shows some promise, however, there are still substantial gaps in the evidence.

  20. A Comprehensive Literature Review of 50 Years of Fuzzy Set Theory

    Cengiz Kahraman

    2016-04-01

    Full Text Available fuzzy sets have a great progress in every scientific research area. it found many application areas in both theoretical and practical studies from engineering area to arts and humanities, from computer science to health sciences, and from life sciences to physical sciences. in this paper, a comprehensive literature review on the fuzzy set theory is realized. in the recent years, ordinary fuzzy sets have been extended to new types and these extensions have been used in many areas such as energy, medicine, material, economics and pharmacology sciences. this literature review also analyzes the chronological development of these extensions. in the last section of the paper, we present our interpretations on the future of fuzzy sets.

  1. A review of the evidence regarding associations between attachment theory and experimentally induced pain.

    Meredith, Pamela Joy

    2013-04-01

    Theoretical and empirical evidence suggests that adult attachment and pain-related variables are predictably and consistently linked, and that understanding these links may guide pain intervention and prevention efforts. In general, insecure attachment has been portrayed as a risk factor, and secure attachment as a protective factor, for people with chronic pain conditions. In an effort to better understand the relationships among attachment and pain variables, these links have been investigated in pain-free samples using induced-pain techniques. The present paper reviews the available research linking adult attachment and laboratory-induced pain. While the diverse nature of the studies precludes definitive conclusions, together these papers offer support for associations between insecure attachment and a more negative pain experience. The evidence presented in this review highlights areas for further empirical attention, as well as providing some guidance for clinicians who may wish to employ preventive approaches and other interventions informed by attachment theory.

  2. Contemporary Cognitive Behavior Therapy: A Review of Theory, History, and Evidence.

    Thoma, Nathan; Pilecki, Brian; McKay, Dean

    2015-09-01

    Cognitive behavior therapy (CBT) has come to be a widely practiced psychotherapy throughout the world. The present article reviews theory, history, and evidence for CBT. It is meant as an effort to summarize the forms and scope of CBT to date for the uninitiated. Elements of CBT such as cognitive therapy, behavior therapy, and so-called "third wave" CBT, such as dialectical behavior therapy (DBT) and acceptance and commitment therapy (ACT) are covered. The evidence for the efficacy of CBT for various disorders is reviewed, including depression, anxiety disorders, personality disorders, eating disorders, substance abuse, schizophrenia, chronic pain, insomnia, and child/adolescent disorders. The relative efficacy of medication and CBT, or their combination, is also briefly considered. Future directions for research and treatment development are proposed.

  3. A Systematic Review Exploring the Social Cognitive Theory of Self-Regulation as a Framework for Chronic Health Condition Interventions.

    Michelle E Tougas

    Full Text Available Theory is often recommended as a framework for guiding hypothesized mechanisms of treatment effect. However, there is limited guidance about how to use theory in intervention development.We conducted a systematic review to provide an exemplar review evaluating the extent to which use of theory is identified and incorporated within existing interventions. We searched electronic databases PubMed, PsycINFO, CENTRAL, and EMBASE from inception to May 2014. We searched clinicaltrials.gov for registered protocols, reference lists of relevant systematic reviews and included studies, and conducted a citation search in Web of Science. We included peer-reviewed publications of interventions that referenced the social cognitive theory of self-regulation as a framework for interventions to manage chronic health conditions. Two reviewers independently assessed articles for eligibility. We contacted all authors of included studies for information detailing intervention content. We describe how often theory mechanisms were addressed by interventions, and report intervention characteristics used to address theory.Of 202 articles that reported using the social cognitive theory of self-regulation, 52% failed to incorporate self-monitoring, a main theory component, and were therefore excluded. We included 35 interventions that adequately used the theory framework. Intervention characteristics were often poorly reported in peer-reviewed publications, 21 of 35 interventions incorporated characteristics that addressed each of the main theory components. Each intervention addressed, on average, six of eight self-monitoring mechanisms, two of five self-judgement mechanisms, and one of three self-evaluation mechanisms. The self-monitoring mechanisms 'Feedback' and 'Consistency' were addressed by all interventions, whereas the self-evaluation mechanisms 'Self-incentives' and 'External rewards' were addressed by six and four interventions, respectively. The present review

  4. Using theory of change to design and evaluate public health interventions: a systematic review.

    Breuer, Erica; Lee, Lucy; De Silva, Mary; Lund, Crick

    2016-05-06

    Despite the increasing popularity of the theory of change (ToC) approach, little is known about the extent to which ToC has been used in the design and evaluation of public health interventions. This review aims to determine how ToCs have been developed and used in the development and evaluation of public health interventions globally. We searched for papers reporting the use of "theory of change" in the development or evaluation of public health interventions in databases of peer-reviewed journal articles such as Scopus, Pubmed, PsychInfo, grey literature databases, Google and websites of development funders. We included papers of any date, language or study design. Both abstracts and full text papers were double screened. Data were extracted and narratively and quantitatively summarised. A total of 62 papers were included in the review. Forty-nine (79 %) described the development of ToC, 18 (29 %) described the use of ToC in the development of the intervention and 49 (79 %) described the use of ToC in the evaluation of the intervention. Although a large number of papers were included in the review, their descriptions of the ToC development and use in intervention design and evaluation lacked detail. The use of the ToC approach is widespread in the public health literature. Clear reporting of the ToC process and outputs is important to strengthen the body of literature on practical application of ToC in order to develop our understanding of the benefits and advantages of using ToC. We also propose a checklist for reporting on the use of ToC to ensure transparent reporting and recommend that our checklist is used and refined by authors reporting the ToC approach.

  5. Optimal patient education for cancer pain: a systematic review and theory-based meta-analysis.

    Marie, N; Luckett, T; Davidson, P M; Lovell, M; Lal, S

    2013-12-01

    Previous systematic reviews have found patient education to be moderately efficacious in decreasing the intensity of cancer pain, but variation in results warrants analysis aimed at identifying which strategies are optimal. A systematic review and meta-analysis was undertaken using a theory-based approach to classifying and comparing educational interventions for cancer pain. The reference lists of previous reviews and MEDLINE, PsycINFO, and CENTRAL were searched in May 2012. Studies had to be published in a peer-reviewed English language journal and compare the effect on cancer pain intensity of education with usual care. Meta-analyses used standardized effect sizes (ES) and a random effects model. Subgroup analyses compared intervention components categorized using the Michie et al. (Implement Sci 6:42, 2011) capability, opportunity, and motivation behavior (COM-B) model. Fifteen randomized controlled trials met the criteria. As expected, meta-analysis identified a small-moderate ES favoring education versus usual care (ES, 0.27 [-0.47, -0.07]; P = 0.007) with substantial heterogeneity (I² = 71 %). Subgroup analyses based on the taxonomy found that interventions using "enablement" were efficacious (ES, 0.35 [-0.63, -0.08]; P = 0.01), whereas those lacking this component were not (ES, 0.18 [-0.46, 0.10]; P = 0.20). However, the subgroup effect was nonsignificant (P = 0.39), and heterogeneity was not reduced. Factoring in the variable of individualized versus non-individualized influenced neither efficacy nor heterogeneity. The current meta-analysis follows a trend in using theory to understand the mechanisms of complex interventions. We suggest that future efforts focus on interventions that target patient self-efficacy. Authors are encouraged to report comprehensive details of interventions and methods to inform synthesis, replication, and refinement.

  6. Extreme and First-Passage Time of Ship Collision Loads

    Nielsen, Søren R. K.; Thoft-Christensen, Palle

    1983-01-01

    The paper outlines a general theory from which the distribution function of the extreme peak collision load encountered during a certain intended lifetime can be cal culated assuming the arrival of ship collisions to be specified by a Poisson counting proces s.......The paper outlines a general theory from which the distribution function of the extreme peak collision load encountered during a certain intended lifetime can be cal culated assuming the arrival of ship collisions to be specified by a Poisson counting proces s....

  7. Towards relativistic heavy ion collisions by small steps towards the stars

    Scott, D.K.

    1979-03-01

    A review lecture is given on current attempts to search for the exotic processes occurring in relativistic heavy ion collisions. From peripheral collisions the discussion proceeds to central collisions and lastly the search for the exotic, in which the tools developed for the study of peripheral and central collisions are used. 200 references

  8. Photon-photon collisions

    Field, J.H.

    1984-01-01

    The current status, both theoretical and experimental, of two photon collision physics is reviewed with special emphasis on recent experimental results from e + e - storage rings. After a complete presentation of the helicity amplitude formalism for the general process e + e - → Xe + e - , various approximations (transverse photon, Weisaecker Williams) are discussed. Beam polarisation effects and radiative corrections are also briefly considered. A number of specific processes, for which experimental results are now available, are then described. In each case existing theoretical prediction are confronted with experimental results. The processes described include single resonance production, lepton and hadron pair production, the structure functions of the photon, the production of high Psub(T) jets and the total photon photon cross section. In the last part of the review the current status of the subject is summarised and some comments are made on future prospects. These include both extrapolations of current research to higher energy machines (LEP, HERA) as well as a brief mention of both the technical realisation and the physics interest of the real γγ and eγ collisions which may be possible using linear electron colliders in the 1 TeV energy range

  9. A systematic review of visual image theory, assessment, and use in skin cancer and tanning research.

    McWhirter, Jennifer E; Hoffman-Goetz, Laurie

    2014-01-01

    Visual images increase attention, comprehension, and recall of health information and influence health behaviors. Health communication campaigns on skin cancer and tanning often use visual images, but little is known about how such images are selected or evaluated. A systematic review of peer-reviewed, published literature on skin cancer and tanning was conducted to determine (a) what visual communication theories were used, (b) how visual images were evaluated, and (c) how visual images were used in the research studies. Seven databases were searched (PubMed/MEDLINE, EMBASE, PsycINFO, Sociological Abstracts, Social Sciences Full Text, ERIC, and ABI/INFORM) resulting in 5,330 citations. Of those, 47 met the inclusion criteria. Only one study specifically identified a visual communication theory guiding the research. No standard instruments for assessing visual images were reported. Most studies lacked, to varying degrees, comprehensive image description, image pretesting, full reporting of image source details, adequate explanation of image selection or development, and example images. The results highlight the need for greater theoretical and methodological attention to visual images in health communication research in the future. To this end, the authors propose a working definition of visual health communication.

  10. Game Theory-Based Cooperation for Underwater Acoustic Sensor Networks: Taxonomy, Review, Research Challenges and Directions

    Dalhatu Muhammed

    2018-02-01

    Full Text Available Exploring and monitoring the underwater world using underwater sensors is drawing a lot of attention these days. In this field cooperation between acoustic sensor nodes has been a critical problem due to the challenging features such as acoustic channel failure (sound signal, long propagation delay of acoustic signal, limited bandwidth and loss of connectivity. There are several proposed methods to improve cooperation between the nodes by incorporating information/game theory in the node’s cooperation. However, there is a need to classify the existing works and demonstrate their performance in addressing the cooperation issue. In this paper, we have conducted a review to investigate various factors affecting cooperation in underwater acoustic sensor networks. We study various cooperation techniques used for underwater acoustic sensor networks from different perspectives, with a concentration on communication reliability, energy consumption, and security and present a taxonomy for underwater cooperation. Moreover, we further review how the game theory can be applied to make the nodes cooperate with each other. We further analyze different cooperative game methods, where their performance on different metrics is compared. Finally, open issues and future research direction in underwater acoustic sensor networks are highlighted.

  11. Game Theory-Based Cooperation for Underwater Acoustic Sensor Networks: Taxonomy, Review, Research Challenges and Directions.

    Muhammed, Dalhatu; Anisi, Mohammad Hossein; Zareei, Mahdi; Vargas-Rosales, Cesar; Khan, Anwar

    2018-02-01

    Exploring and monitoring the underwater world using underwater sensors is drawing a lot of attention these days. In this field cooperation between acoustic sensor nodes has been a critical problem due to the challenging features such as acoustic channel failure (sound signal), long propagation delay of acoustic signal, limited bandwidth and loss of connectivity. There are several proposed methods to improve cooperation between the nodes by incorporating information/game theory in the node's cooperation. However, there is a need to classify the existing works and demonstrate their performance in addressing the cooperation issue. In this paper, we have conducted a review to investigate various factors affecting cooperation in underwater acoustic sensor networks. We study various cooperation techniques used for underwater acoustic sensor networks from different perspectives, with a concentration on communication reliability, energy consumption, and security and present a taxonomy for underwater cooperation. Moreover, we further review how the game theory can be applied to make the nodes cooperate with each other. We further analyze different cooperative game methods, where their performance on different metrics is compared. Finally, open issues and future research direction in underwater acoustic sensor networks are highlighted.

  12. Overweight but unseen: a review of the underestimation of weight status and a visual normalization theory.

    Robinson, E

    2017-10-01

    Although overweight and obesity are widespread across most of the developed world, a considerable body of research has now accumulated, which suggests that adiposity often goes undetected. A substantial proportion of individuals with overweight or obesity do not identify they are overweight, and large numbers of parents of children with overweight or obesity fail to identify their child as being overweight. Lay people and medical practitioners are also now poor at identifying overweight and obesity in others. A visual normalization theory of the under-detection of overweight and obesity is proposed. This theory is based on the notion that weight status is judged relative to visual body size norms. Because larger body sizes are now common, this has caused a recalibration to the range of body sizes that are perceived as being 'normal' and increased the visual threshold for what constitutes 'overweight'. Evidence is reviewed that indicates this process has played a significant role in the under-detection of overweight and obesity. The public health relevance of the under-detection of overweight and obesity is also discussed. © 2017 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of World Obesity.

  13. A Treatise for A New Age in Economic Theory: A Review of George Reisman's Capitalism

    Wladimir Kraus

    2009-02-01

    Full Text Available George Reisman’s magnum opus Capitalism: A Treatise on Economics is a monumental attempt at theoretical integration of leading economic phenomena into one unified whole. Few such books have been published in the history of economics. Still fewer of them contain a comparable proportion of path-breaking innovations both in approach and substance that are integrated in a tightly-spun system of thought that Capitalism does. Yet despite its numerous path-breaking contributions to economic theory, the book has attracted virtually zero attention from the scientific community. History shows that for the most part this has been the fate of all great innovations in science. This review attempts (a to point out reasons why the book’s content is revolutionary, and (b to finally start a serious discussion of its substantive ideas. Specifically, the review focuses in some detail on some of Reisman’s most important innovations which all point the way to a wholly new direction in economic theory that promises to provide the hitherto unseen conformity with empirical reality, analytical rigor, and doctrinal integration.

  14. Game Theory-Based Cooperation for Underwater Acoustic Sensor Networks: Taxonomy, Review, Research Challenges and Directions

    Muhammed, Dalhatu; Anisi, Mohammad Hossein; Vargas-Rosales, Cesar; Khan, Anwar

    2018-01-01

    Exploring and monitoring the underwater world using underwater sensors is drawing a lot of attention these days. In this field cooperation between acoustic sensor nodes has been a critical problem due to the challenging features such as acoustic channel failure (sound signal), long propagation delay of acoustic signal, limited bandwidth and loss of connectivity. There are several proposed methods to improve cooperation between the nodes by incorporating information/game theory in the node’s cooperation. However, there is a need to classify the existing works and demonstrate their performance in addressing the cooperation issue. In this paper, we have conducted a review to investigate various factors affecting cooperation in underwater acoustic sensor networks. We study various cooperation techniques used for underwater acoustic sensor networks from different perspectives, with a concentration on communication reliability, energy consumption, and security and present a taxonomy for underwater cooperation. Moreover, we further review how the game theory can be applied to make the nodes cooperate with each other. We further analyze different cooperative game methods, where their performance on different metrics is compared. Finally, open issues and future research direction in underwater acoustic sensor networks are highlighted. PMID:29389874

  15. Cluster-collision frequency. II. Estimation of the collision rate

    Amadon, A.S.; Marlow, W.H.

    1991-01-01

    Gas-phase cluster-collision rates, including effects of cluster morphology and long-range intermolecular forces, are calculated. Identical pairs of icosahedral or dodecahedral carbon tetrachloride clusters of 13, 33, and 55 molecules in two different relative orientations were discussed in the preceding paper [Phys. Rev. A 43, 5483 (1991)]: long-range interaction energies were derived based upon (i) exact calculations of the iterated, or many-body, induced-dipole interaction energies for the clusters in two fixed relative orientations; and (ii) bulk, or continuum descriptions (Lifshitz--van der Waals theory), of spheres of corresponding masses and diameters. In this paper, collision rates are calculated according to an exact description of the rates for small spheres interacting via realistic potentials. Utilizing the interaction energies of the preceding paper, several estimates of the collision rates are given by treating the discrete clusters in fixed relative orientations, by computing rotationally averaged potentials for the discrete clusters, and by approximating the clusters as continuum spheres. For the discrete, highly symmetric clusters treated here, the rates using the rotationally averaged potentials closely approximate the fixed-orientation rates and the values of the intercluster potentials for cluster surface separations under 2 A have negligible effect on the overall collision rates. While the 13-molecule cluster-collision rate differs by 50% from the rate calculated as if the cluster were bulk matter, the two larger cluster-collision rates differ by less than 15% from the macroscopic rates, thereby indicating the transition of microscopic to macroscopic behavior

  16. Social cognitive theories used to explain physical activity behavior in adolescents: a systematic review and meta-analysis.

    Plotnikoff, Ronald C; Costigan, Sarah A; Karunamuni, Nandini; Lubans, David R

    2013-05-01

    To systematically review and examine the explanatory power of key social-cognitive theories used to explain physical activity (PA) intention and behavior, among adolescents. A systematic review and meta-analysis of the literature was performed using the electronic databases Medline, Cumulative Index to Nursing and Allied Health Literature, SPORTdiscus, EBSCO and Education Resources Information Center, Proquest Education Journals Collection, Science Direct, Web of Science and Scopus for social-cognitive theories (i.e., Health Promotion Model, Theory of Planned Behavior, Theory of Reasoned Action, Protection Motivation Theory, Social Cognitive Theory/Self-Efficacy Theory, Health Belief Model, Self-Determination Theory, Transtheoretical Model) used to explain PA intention and behavior. Related keywords in titles, abstracts, or indexing fields were searched. Twenty-three studies satisfied the inclusion criteria and were retained for data extraction and analysis; 16 were cross-sectional studies and seven were longitudinal studies. Most studies employed self-report measures. In general, the models explained greater proportions of variance for intention compared to behavior. The meta-analyses revealed 33% and 48% of the variance respectively for PA and intention were explained by social cognitive models. Few studies have tested the predictive capacity of social cognitive theories to explain objectively measured PA. The majority of PA variance remains unexplained and more theoretical research is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Skin cancer interventions across the cancer control continuum: Review of technology, environment, and theory.

    Taber, Jennifer M; Dickerman, Barbra A; Okhovat, Jean-Phillip; Geller, Alan C; Dwyer, Laura A; Hartman, Anne M; Perna, Frank M

    2018-06-01

    The National Cancer Institute's Skin Cancer Intervention across the Cancer Control Continuum model was developed to summarize research and identify gaps concerning skin cancer interventions. We conducted a mapping review to characterize whether behavioral interventions addressing skin cancer prevention and control from 2000 to 2015 included (1) technology, (2) environmental manipulations (policy and/or built environment), and (3) a theoretical basis. We included 86 studies with a randomized controlled or quasi-experimental design that targeted behavioral intervention in skin cancer for children and/or adults; seven of these were dissemination or implementation studies. Of the interventions described in the remaining 79 articles, 57 promoted only prevention behaviors (e.g., ultraviolet radiation protection), five promoted only detection (e.g., skin examinations), 10 promoted both prevention and detection, and seven focused on survivorship. Of the 79 non-dissemination studies, two-thirds used some type of technology (n=52; 65.8%). Technology specific to skin cancer was infrequently used: UVR photography was used in 15.2% of studies (n=12), reflectance spectroscopy was used in 12.7% (n=10), and dermatoscopes (n=1) and dosimeters (n=2) were each used in less than 3%. Ten studies (12.7%) targeted the built environment. Fifty-two (65.8%) of the studies included theory-based interventions. The most common theories were Social Cognitive Theory (n=20; 25.3%), Health Belief Model (n=17; 21.5%), and the Theory of Planned Behavior/Reasoned Action (n=12; 15.2%). Results suggest that skin cancer specific technology and environmental manipulations are underutilized in skin cancer behavioral interventions. We discuss implications of these results for researchers developing skin cancer behavioral interventions. Copyright © 2017. Published by Elsevier Inc.

  18. A qualitative systematic review of studies using the normalization process theory to research implementation processes.

    McEvoy, Rachel; Ballini, Luciana; Maltoni, Susanna; O'Donnell, Catherine A; Mair, Frances S; Macfarlane, Anne

    2014-01-02

    There is a well-recognized need for greater use of theory to address research translational gaps. Normalization Process Theory (NPT) provides a set of sociological tools to understand and explain the social processes through which new or modified practices of thinking, enacting, and organizing work are implemented, embedded, and integrated in healthcare and other organizational settings. This review of NPT offers readers the opportunity to observe how, and in what areas, a particular theoretical approach to implementation is being used. In this article we review the literature on NPT in order to understand what interventions NPT is being used to analyze, how NPT is being operationalized, and the reported benefits, if any, of using NPT. Using a framework analysis approach, we conducted a qualitative systematic review of peer-reviewed literature using NPT. We searched 12 electronic databases and all citations linked to six key NPT development papers. Grey literature/unpublished studies were not sought. Limitations of English language, healthcare setting and year of publication 2006 to June 2012 were set. Twenty-nine articles met the inclusion criteria; in the main, NPT is being applied to qualitatively analyze a diverse range of complex interventions, many beyond its original field of e-health and telehealth. The NPT constructs have high stability across settings and, notwithstanding challenges in applying NPT in terms of managing overlaps between constructs, there is evidence that it is a beneficial heuristic device to explain and guide implementation processes. NPT offers a generalizable framework that can be applied across contexts with opportunities for incremental knowledge gain over time and an explicit framework for analysis, which can explain and potentially shape implementation processes. This is the first review of NPT in use and it generates an impetus for further and extended use of NPT. We recommend that in future NPT research, authors should explicate

  19. Inelastic collisions of OH (2Pi) with H2: Comparison between theory and experiment including rotational, fine structure, and Λ-doublet transitions

    Schinke, R.; Andresen, P.

    1984-01-01

    Detailed cross section calculations for inelastic collisions of OH ( 2 Pi) in the ground state j = 3/2, Omega-bar = 3/2 with H 2 are presented using an ab initio potential energy surface without adjustable parameters. The OH molecular wave function is described within the intermediate coupling case. The results are compared with recent experiments. The agreement is satisfactory for the final rotational state distributions within both the Omega-bar = 3/2 and the Omega-bar = 1/2 ladder. Also the relative magnitude of Omega-bar = 1/2 and 3/2 cross sections is in good accord with experiment and thus indicates that the difference potential V/sub A/'-V/sub A/'' is realistically described by the ab initio calculation. The dynamical calculations yield prefential excitation of one Λ-doublet state. The extent of this preference increases with j and is larger for Omega-bar = 3/2 in qualitative but not quantitative agreement with experiment. Possible interpretations in terms of the potential energy surfaces are briefly discussed

  20. A review on application of MHD theory to plasma boundary problems in tokamaks

    Itoh, Kimitaka.

    1992-08-01

    A survey is made on the problems of the edge plasmas, to which the analyses based on the MHD theory have been successfully applied. Also discussed are the efforts to extend the model equation to more general (and important as well) problems such as H-mode physics. An overview is first made on the advantages of the MHD picture, and the necessary supplementary physics are examined. Next, one- and two-dimensional models of the spatial structure of the edge plasma is discussed. The results on the stationary structure, both analytical and numerical, are reviewed: Typical example as well as the scaling law are shown. The instabilities associated with edge plasma is next reviewed. The surface kink mode, ballooning mode, interchange mode, resistive interchange mode and thermal instability are discussed. Role of the geometry such as the location of the X-point is studied. Influences of the atomic processes, and those of the radial electric field are also discussed. The analysis of the H-mode transition physics is finally discussed. The boundary plasma is a nonlinear media which possesses the possibility for bifurcation in which the radial electric field plays a key role. The model of the ion viscosity is also studied. Transition physics is developed. Analysis on the self-generating oscillation is shown and the relation with ELMs is discussed. After reviewing these problems, several comments are made to what directions the study can be deepened. (author) 53 refs

  1. Research review: evaluating and reformulating the developmental taxonomic theory of antisocial behaviour.

    Fairchild, Graeme; van Goozen, Stephanie H M; Calder, Andrew J; Goodyer, Ian M

    2013-09-01

    The developmental taxonomic theory proposes that there are two subtypes of antisocial behaviour. The first is a neurodevelopmental disorder which emerges in early childhood and follows a life-course persistent course, whereas the second emerges in adolescence, remits in early adulthood and reflects peer processes such as mimicry of antisocial peers. The aim of this review was to evaluate the developmental taxonomic theory in the light of recent empirical research. We conducted a comprehensive literature review comparing these subtypes of antisocial behaviour based on searches on PubMed and other scientific databases covering the period from 1993 to 2013. We focused on research encompassing psychiatric epidemiology, personality assessment, neuropsychology, neuroendocrinology, genetics, and structural and functional neuroimaging. Sixty one empirical studies were identified that investigated one of these forms of antisocial behaviour separately or explicitly compared childhood-onset and adolescence-onset forms of antisocial behaviour. Empirical research provides support for the hypothesis that life-course persistent antisocial behaviour is a neurodevelopmental disorder which emerges in the transactions between individual vulnerabilities and environmental adversity. In contrast to the developmental taxonomic theory, however, empirical findings suggest that severe antisocial behaviour that emerges in adolescence frequently has a negative prognosis and is rarely limited to the adolescent period. In addition, both forms of antisocial behaviour are associated with emotion processing deficits, changes in brain structure and function, alterations in cortisol secretion, and atypical personality traits (such as increased callous-unemotional traits). We conclude that the developmental taxonomic theory is in need of revision, as differences between life-course persistent and adolescence-onset forms of antisocial behaviour appear to be quantitative, rather than qualitative, in

  2. Research Review: Evaluating and reformulating the developmental taxonomic theory of antisocial behaviour

    Fairchild, Graeme; Goozen, Stephanie HM; Calder, Andrew J; Goodyer, Ian M

    2013-01-01

    BackgroundThe developmental taxonomic theory proposes that there are two subtypes of antisocial behaviour. The first is a neurodevelopmental disorder which emerges in early childhood and follows a life-course persistent course, whereas the second emerges in adolescence, remits in early adulthood and reflects peer processes such as mimicry of antisocial peers. The aim of this review was to evaluate the developmental taxonomic theory in the light of recent empirical research. MethodsWe conducted a comprehensive literature review comparing these subtypes of antisocial behaviour based on searches on PubMed and other scientific databases covering the period from 1993 to 2013. We focused on research encompassing psychiatric epidemiology, personality assessment, neuropsychology, neuroendocrinology, genetics, and structural and functional neuroimaging. Sixty one empirical studies were identified that investigated one of these forms of antisocial behaviour separately or explicitly compared childhood-onset and adolescence-onset forms of antisocial behaviour. ResultsEmpirical research provides support for the hypothesis that life-course persistent antisocial behaviour is a neurodevelopmental disorder which emerges in the transactions between individual vulnerabilities and environmental adversity. In contrast to the developmental taxonomic theory, however, empirical findings suggest that severe antisocial behaviour that emerges in adolescence frequently has a negative prognosis and is rarely limited to the adolescent period. In addition, both forms of antisocial behaviour are associated with emotion processing deficits, changes in brain structure and function, alterations in cortisol secretion, and atypical personality traits (such as increased callous-unemotional traits). ConclusionsWe conclude that the developmental taxonomic theory is in need of revision, as differences between life-course persistent and adolescence-onset forms of antisocial behaviour appear to be

  3. Theory for passive mode-locking in semiconductor laser structures including the effects of self-phase modulation, dispersion and pulse collisions

    Koumans, R.G.M.P.; Roijen, van R.

    1996-01-01

    We present a theory for passive mode-locking in semiconductor laser structures using a semiconductor laser amplifier and absorber. The mode-locking system is described in terms of the different elements in the semiconductor laser structure. We derive mode-locking conditions and show how other

  4. Theories of reproduction and resistance: a review of the educational debate from the materialist perspective

    Dana Hirsch

    2015-02-01

    Full Text Available The question of whether school is a place for social transformation or not is a central issue to modern educational thought, particularly in the last decades of the twentieth century. «Theories of resistance» of the 80’s and 90’s aimed to show the transformative potential of schooling through the development of a critical pedagogy, in clear response to the so called «theories of reproduction», which in the 70›had denounced the role played by school in capitalism. This article aims to make a review of this discussion and, particularly, the antagonistic form in which it has been developed, from a materialist perspective. To that end, main classics of both group of theories will be analyzed identifying that, although they seem antagonist, they coincide on one central point: the belief that capitalist social relations are imposed externally to the subject, to a supposal free subjectivity. While «theories of reproduction» argue that such domination can only be faced through class struggle, which can only be given outside school, «theories of resistance» argue that struggle may be developedin the ideological sphere within schooling. The premise of this article is that such external imposition is an appearance product of the alienated character of our consciousness, and does not allow to analyze that social relations, far from being imposed to our free will, are developed by us to organize social work. To transcend these appearances, a process of recognition of the general determinations of education in capitalism will be developed, in order to enable us to overcome a binary logic between reproduction and transformation, and think social transformation as part of the process of social organization itself.How to reference this articleHirsch, D., Rio, V. (2015. Teorías de la reproducción y teorías de la resistencia: una revisión del debate pedagógico desde la perspectiva materialista. Foro de Educación, 13(18, pp. 69-91. doi: http

  5. Gaze movements and spatial working memory in collision avoidance: a traffic intersection task

    Gregor eHardiess

    2013-06-01

    Full Text Available Street crossing under traffic is an everyday activity including collision detection as well as avoidance of objects in the path of motion. Such tasks demand extraction and representation of spatio-temporal information about relevant obstacles in an optimized format. Relevant task information is extracted visually by the use of gaze movements and represented in spatial working memory. In a virtual reality traffic intersection task, subjects are confronted with a two-lane intersection where cars are appearing with different frequencies, corresponding to high and low traffic densities. Under free observation and exploration of the scenery (using unrestricted eye and head movements the overall task for the subjects was to predict the potential-of-collision (POC of the cars or to adjust an adequate driving speed in order to cross the intersection without collision (i.e., to find the free space for crossing. In a series of experiments, gaze movement parameters, task performance, and the representation of car positions within working memory at distinct time points were assessed in normal subjects as well as in neurological patients suffering from homonymous hemianopia. In the following, we review the findings of these experiments together with other studies and provide a new perspective of the role of gaze behavior and spatial memory in collision detection and avoidance, focusing on the following questions: (i which sensory variables can be identified supporting adequate collision detection? (ii How do gaze movements and working memory contribute to collision avoidance when multiple moving objects are present and (iii how do they correlate with task performance? (iv How do patients with homonymous visual field defects use gaze movements and working memory to compensate for visual field loss? In conclusion, we extend the theory of collision detection and avoidance in the case of multiple moving objects and provide a new perspective on the combined

  6. The Anthropology of Airports, Criticism to Non Place Theory (Essay-Review

    Maximiliano E. KORSTANJE

    2015-06-01

    Full Text Available This text contains a set of personal experiences, product of my personal ethnographies in well-known airports, as well as a conceptual discussion around non-place´s theory. Marc Augé, a famous ethnographer, formulated this thesis to express a deep analysis about the philosophy of modernity and mobility. He is convinced that modernity has been changed into a new way, hyper-modernity, which is a producer of “non-places”, spaces of anonymity that effaces the attachment to past. This essay-review not only contradicts with such a radical idea, but also presents contrary evidence respecting to airports as disciplinary mechanism of control, oriented to disseminate to citizens, the main values of society.

  7. Navigating Glycerol Conversion Roadmap and Heterogeneous Catalyst Selection Aided by Density Functional Theory: A Review

    Bin Liu

    2018-01-01

    Full Text Available Glycerol has been utilized in an extremely diversified manner throughout human civilization—ranging from food, to various consumer products, to pharmaceuticals, and even explosives. Large surplus in glycerol supply thanks to biodiesel production and biomass processing has created a demand to further boost its utility. One growing area is to expand the use of glycerol as an alternative feedstock to supplement fuels and chemicals production. Various catalytic processes have been developed. This review summarizes catalytic materials for glycerol reforming, hydrodeoxygenation, and oxidation. In particular, rationale for catalyst selection and new catalyst design will be discussed aided by the knowledge of reaction mechanisms. The role of theoretical density functional theory (DFT in elucidating complex glycerol conversion chemistries is particularly emphasized.

  8. The HEXACO Honesty-Humility, Agreeableness, and Emotionality factors: a review of research and theory.

    Ashton, Michael C; Lee, Kibeom; de Vries, Reinout E

    2014-05-01

    We review research and theory on the HEXACO personality dimensions of Honesty-Humility (H), Agreeableness (A), and Emotionality (E), with particular attention to the following topics: (1) the origins of the HEXACO model in lexical studies of personality structure, and the content of the H, A, and E factors in those studies; (2) the operationalization of the H, A, and E factors in the HEXACO Personality Inventory-Revised; (3) the construct validity of self-reports on scales measuring the H factor; (4) the theoretical distinction between H and A; (5) similarity and assumed similarity between social partners in personality, with a focus on H and A; (6) the extent to which H (and A and E) variance is represented in instruments assessing the "Five-Factor Model" of personality; and (7) the relative validity of scales assessing the HEXACO and Five-Factor Model dimensions in predicting criteria conceptually relevant to H, A, and E.

  9. A Systematic Review of the Evidence for Impaired Cognitive Theory of Mind in Maltreated Children.

    Benarous, Xavier; Guilé, Jean-Marc; Consoli, Angèle; Cohen, David

    2015-01-01

    Compared to the large number of studies exploring difficulties in emotion recognition in maltreated children, few (N = 12) have explored the cognitive aspect of theory of mind (ToM), i.e., the ability to understand others' thoughts and intentions. A systematic review of these studies shows inconsistent results regarding cognitive ToM tasks. Youths with a history of maltreatment are more likely to fail at false-belief tasks (N = 2). However, results are less conclusive regarding other tasks (perspective-taking tasks, N = 4; and hostile attribution tasks, N = 7). Additionally, only one study controlled for potential psychopathology. Measures of psychopathology and other cognitive abilities, in addition to ToM, are required to establish a specific association between maltreatment and the cognitive dimension of ToM.

  10. Structured Literature Review of disruptive innovation theory within the digital domain

    Vesti, Helle; Nielsen, Christian; Rosenstand, Claus Andreas Foss

    2017-01-01

    The area of interest is disruption is the digital domain. The research questions are: How has the disruption and digital disruption literature developed over time? What is the research focus into disruption regarding the digital domain and how has this changed over time? Which methods are being...... utilized in research regarding disruption and digital disruption? Where are the key contributors to disruption in general and in digital disruption? Is there a future for digital disruption research? The method is a Structured Literature Review (SLR). The contribution is the results of an analysis of 95...... publications within the field of disruption in the digital domain and disruptive innovation theory in general. Works of twelve practitioners and 83 academics are investigated....

  11. Trapping of dilute ion components in wells and double wells in higher equatorial magnetic regions: A kinetic theory including collisions, varying background and additional fields

    Oeien, Alf H.

    2001-08-01

    The component of the ambipolar field along the magnetic field B, though weak, may, acting together with the gravitational field, give rise to along-B ''ambipolar wells'' where light ions (test particles) in the ionosphere in equatorial regions are trapped. We also take into account magnetic field wells, especially in cases when the along-B velocity of test particles are much less than the transverse-B velocities. For heavy ions, or, for light ions high up, when the ambipolar trap ceases to function, the along-B ambipolar- and gravitational field effects may combine with the magnetic field trap to form a double well for the along-B movement of test particles. The magnetic field trap and its contribution to the double well may be nearly stationary for particles obeying the same velocity condition as above even when collisional effects between the test particles and the background plasma are incorporated. Ions trapped in wells like this, may ''feel'' a varying background, for instance because of Earth rotation, that may be incorporated as time-variation of parameters in the along-B motion. An along-B kinetic equation for groups of test particles is solved both for the case of simple wells and for double wells, including time-varying collisional coefficients and additional fields, and in some cases analytic solutions are obtained. Peculiar along-B distribution functions may arise due to the time-dependency of coefficients and to various combinations of collision- and field parameter values. In particular ''breathing'' distributions that alternate between wide and narrow forms in phase-space may arise, and also distributions where strange attractors may play some role.

  12. Prior Knowledge and the Learning of Science. A Review of Ausubel's Theory of This Process

    West, L. H. T.; Fensham, P. J.

    1974-01-01

    Examines Ausubel's theory of learning as a model of the role concerning the influence of prior knowledge on how learning occurs. Research evidence for Ausubel's theory is presented and discussed. Implications of Ausubel's theory for teaching are summarized. (PEB)

  13. Collision Repair Campaign

    The Collision Repair Campaign targets meaningful risk reduction in the Collision Repair source category to reduce air toxic emissions in their communities. The Campaign also helps shops to work towards early compliance with the Auto Body Rule.

  14. Neuromorphic UAS Collision Avoidance

    National Aeronautics and Space Administration — Collision avoidance for unmanned aerial systems (UAS) traveling at high relative speeds is a challenging task. It requires both the detection of a possible collision...

  15. Relativistic Collisions of Structured Atomic Particles

    Voitkiv, Alexander

    2008-01-01

    The book reviews the progress achieved over the last decade in the study of collisions between an ion and an atom in which both the atomic particles carry electrons and can undergo transitions between their internal states -- including continua. It presents the detailed considerations of different theoretical approaches, that can be used to describe collisions of structured atomic particles for the very broad interval of impact energies ranging from 0.5--1 MeV/u till extreme relativistic energies where the collision velocity very closely approaches the speed of light.

  16. High energy hadron-hadron collisions

    Chou, T.T.

    1990-01-01

    Results of a study on high energy collision with the geometrical model are summarized in three parts: (i) the elastic hadron-hadron collision, (ii) the inelastic hadron-hadron collision, and (iii) the e + e - annihilation. The geometrical description of high-energy elastic scattering developed earlier is still in general agreement with experiments at the CERN-S bar ppS energies. A simple one-parameter expression for the blackness of bar pp system has been proposed recently which describes very well all existing data from ISR to S bar ppS energies. The geometrical description has also been extended to include processes of fragmentation and diffraction dissociation and other phenomena. In the past five years, a unified physical picture for multiparticle emission in hadron-hadron and e + e - collisions was developed. It focuses on the idea of the wide range of values for the total angular momentum in hadron-hadron collisions. An extension of this consideration yields a theory for the momentum distribution of the outgoing particles which agrees with bar pp and e + e - collision experiments. The results and conclusions of this theory have been extrapolated to higher energies and yielded many predictions which can be experimentally tested. 37 refs

  17. Ion-ion collisions

    Salzborn, Erhard; Melchert, Frank

    2000-01-01

    Collisions between ions belong to the elementary processes occurring in all types of plasmas. In this article we give a short overview about collisions involving one-electron systems. For collisions involving multiply-charged ions we limit the discussion to one specific quasi-one-electron system. (author)

  18. Pedagogical Review of Quantum Measurement Theory with an Emphasis on Weak Measurements

    Bengt E. Y. Svensson

    2013-05-01

    Full Text Available The quantum theory of measurement has been with us since quantum mechanics was invented. It has recently been invigorated, partly due to the increasing interest in quantum information science. In this partly pedagogical review I attempt to give a self-contained overview of non-relativistic quantum theory of measurement expressed in density matrix formalism. I will not dwell on the applications in quantum information theory; it is well covered by several books in that field. The focus is instead on applications to the theory of weak measurement, as developed by Aharonov and collaborators. Their development of weak measurement combined with what they call post-selection - judiciously choosing not only the initial state of a system (pre-selection but also its final state - has received much attention recently. Not the least has it opened up new, fruitful experimental vistas, like novel approaches to amplification. But the approach has also attached to it some air of mystery. I will attempt to demystify it by showing that (almost all results can be derived in a straight-forward way from conventional quantum mechanics. Among other things, I develop the formalism not only to first order but also to second order in the weak interaction responsible for the measurement. I apply it to the so called Leggett-Garg inequalities, also known as Bell inequalities in time. I also give an outline, even if rough, of some of the ingenious experiments that the work by Aharonov and collaborators has inspired. As an application of weak measurement, not related to the approach by Aharonov and collaborators, the formalism also allows me to derive the master equation for the density matrix of an open system in interaction with an environment. An issue that remains in the weak measurement plus post-selection approach is the interpretation of the so called weak value of an observable. Is it a bona fide property of the system considered? I have no definite answer to this

  19. Thermophysical properties of simple liquid metals: A brief review of theory

    Stroud, David

    1993-01-01

    In this paper, we review the current theory of the thermophysical properties of simple liquid metals. The emphasis is on thermodynamic properties, but we also briefly discuss the nonequilibrium properties of liquid metals. We begin by defining a 'simple liquid metal' as one in which the valence electrons interact only weakly with the ionic cores, so that the interaction can be treated by perturbation theory. We then write down the equilibrium Hamiltonian of a liquid metal as a sum of five terms: the bare ion-ion interaction, the electron-electron interaction, the bare electron-ion interaction, and the kinetic energies of electrons and ions. Since the electron-ion interaction can be treated by perturbation, the electronic part contributes in two ways to the Helmholtz free energy: it gives a density-dependent term which is independent of the arrangement of ions, and it acts to screen the ion-ion interaction, giving rise to effective ion-ion pair potentials which are density-dependent, in general. After sketching the form of a typical pair potential, we briefly enumerate some methods for calculating the ionic distribution function and hence the Helmholtz free energy of the liquid: monte Carlo simulations, molecular dynamics simulations, and thermodynamic perturbation theory. The final result is a general expression for the Helmholtz free energy of the liquid metal. It can be used to calculate a wide range of thermodynamic properties of simple metal liquids, which we enumerate. They include not only a range of thermodynamic coefficients of both metals and alloys, but also many aspects of the phase diagram, including freezing curves of pure elements and phase diagrams of liquid alloys (including liquidus and solidus curves). We briefly mention some key discoveries resulting from previous applications of this method, and point out that the same methods work for other materials not normally considered to be liquid metals (such as colloidal suspensions, in which the

  20. Social cognitive theory and physical activity: a systematic review and meta-analysis.

    Young, M D; Plotnikoff, R C; Collins, C E; Callister, R; Morgan, P J

    2014-12-01

    This review investigated three research questions (i) What is the utility of social cognitive theory (SCT) to explain physical activity (PA)?; (ii) Is the effectiveness of SCT moderated by sample or methodological characteristics? and (iii) What is the frequency of significant associations between the core SCT constructs and PA? Ten electronic databases were searched with no date or sample restrictions. Forty-four studies were retrieved containing 55 SCT models of PA. Methodological quality was assessed using a standardized tool. A random-effects meta-analysis revealed that SCT accounted for 31% of the variance in PA. However, methodological quality was mostly poor for these models. Methodological quality and sample age moderated the PA effect size, with increases in both associated with greater variance explained. Although self-efficacy and goals were consistently associated with PA, outcome expectations and socio-structural factors were not. This review determined that SCT is a useful framework to explain PA behaviour. Higher quality models explained more PA variance, but overall methodological quality was poor. As such, high-quality studies examining the utility of SCT to explain PA are warranted. © 2014 World Obesity.

  1. A Review on Block Matching Motion Estimation and Automata Theory based Approaches for Fractal Coding

    Shailesh Kamble

    2016-12-01

    Full Text Available Fractal compression is the lossy compression technique in the field of gray/color image and video compression. It gives high compression ratio, better image quality with fast decoding time but improvement in encoding time is a challenge. This review paper/article presents the analysis of most significant existing approaches in the field of fractal based gray/color images and video compression, different block matching motion estimation approaches for finding out the motion vectors in a frame based on inter-frame coding and intra-frame coding i.e. individual frame coding and automata theory based coding approaches to represent an image/sequence of images. Though different review papers exist related to fractal coding, this paper is different in many sense. One can develop the new shape pattern for motion estimation and modify the existing block matching motion estimation with automata coding to explore the fractal compression technique with specific focus on reducing the encoding time and achieving better image/video reconstruction quality. This paper is useful for the beginners in the domain of video compression.

  2. Using Achievement Goal Theory in Motor Skill Instruction: A Systematic Review.

    Palmer, Kara K; Chinn, Katherine M; Robinson, Leah E

    2017-12-01

    Over the past two decades, achievement goal theory (AGT) has been used as a theoretical framework to design and implement motor skill programming in young children. The purpose of this systematic review was to examine the effects of AGT in motor skill interventions and programming in children aged 0-12 years. This systematic literature search was conducted using three databases: Google Scholar, PubMed, and EBSCOhost. Studies were included if they met the following four inclusion criteria: (1) had an intervention with a gross motor outcome, (2) used an intervention grounded in AGT, (3) included young children (aged 0-12 years), and (4) were written in English. Studies were rated according to methodological reporting quality. All literature searches and reporting were consistent with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol. A total of 12 studies met all inclusion criteria and were included in the sample. All studies reported that AGT motor skill interventions were effective for improving motor skills in young children. Studies varied in regard to intervention groups, duration, dosage, and the personnel responsible for implementing the intervention. None of the included studies met the requirements to be considered as having high methodological quality. Based on these findings, AGT is an effective theoretical approach for designing and implementing motor skill interventions for young children.

  3. Quantitative correlations between collision induced dissociation mass spectrometry coupled with electrospray ionization or atmospheric pressure chemical ionization mass spectrometry - Experiment and theory

    Ivanova, Bojidarka; Spiteller, Michael

    2018-04-01

    The problematic that we consider in this paper treats the quantitative correlation model equations between experimental kinetic and thermodynamic parameters of coupled electrospray ionization (ESI) mass spectrometry (MS) or atmospheric pressure chemical ionization (APCI) mass spectrometry with collision induced dissociation mass spectrometry, accounting for the fact that the physical phenomena and mechanisms of ESI- and APCI-ion formation are completely different. There are described forty two fragment reactions of three analytes under independent ESI- and APCI-measurements. The developed new quantitative models allow us to study correlatively the reaction kinetics and thermodynamics using the methods of mass spectrometry, which complementary application with the methods of the quantum chemistry provide 3D structural information of the analytes. Both static and dynamic quantum chemical computations are carried out. The object of analyses are [2,3-dimethyl-4-(4-methyl-benzoyl)-2,3-di-p-tolyl-cyclobutyl]-p-tolyl-methanone (1) and the polycyclic aromatic hydrocarbons derivatives of dibenzoperylen (2) and tetrabenzo [a,c,fg,op]naphthacene (3), respectively. As far as (1) is known to be a product of [2π+2π] cycloaddition reactions of chalcone (1,3-di-p-tolyl-propenone), however producing cyclic derivatives with different stereo selectivity, so that the study provide crucial data about the capability of mass spectrometry to provide determine the stereo selectivity of the analytes. This work also first provides quantitative treatment of the relations '3D molecular/electronic structures'-'quantum chemical diffusion coefficient'-'mass spectrometric diffusion coefficient', thus extending the capability of the mass spectrometry for determination of the exact 3D structure of the analytes using independent measurements and computations of the diffusion coefficients. The determination of the experimental diffusion parameters is carried out within the 'current monitoring method

  4. Collision-induced dissociation of diatomic ions

    Los, J.; Govers, T.R.

    1978-01-01

    An attempt is made to illustrate how mass spectrometric studies of dissociation in diatomic molecular ions can provide information on the dynamics of these collisions and on the predissociative states involved. Restriction is made to primary beam energies of the order of at least keV. The review covers the dynamics of dissociation, experimental techniques, direct dissociation in heavy-particle collisions, and translational spectroscopy. 120 references

  5. Study of reactive collisions between electrons and molecular cations using multichannel quantum defect theory: Application to HD{sup +} and BeH{sup +}

    Pop, N., E-mail: nicolina.pop@upt.ro; Ilie, S. [Politehnica University of Timişoara, Department of Physical Foundation of Engineering, Vasile Pârvan Blvd., 300223 Timisoara (Romania); Motapon, O.; Epée, M. D. Epée [Physics Department, University of Douala, P. O. Box 24157, Douala (Cameroon); Niyonzima, S. [Laboratoire Ondes and Milieux Complexes CNRS- UMR-6294, Université du Havre, 76058, Le Havre, France and Département de Physique, Faculté des Sciences, Université du Burundi, B.P. 2700 Bujumbura (Burundi); Mezei, J. Zs. [Laboratoire Ondes and Milieux Complexes CNRS- UMR-6294, Université du Havre, 76058, Le Havre (France); Laboratoire Aimé-Cotton CNRS-UPR-3321, Université Paris-Sud, F-91405 Orsay (France); Institute of Nuclear Research of the Hung (Hungary); Chakrabarti, K. [Dept. of Mathematics, Scottish Church College, 1 and 3 Urquhart Sq., Kolkata 700 006 (India); Schneider, I. F. [Laboratoire Ondes and Milieux Complexes CNRS- UMR-6294, Université du Havre, 76058, Le Havre (France)

    2014-11-24

    The present work is aimed at performing the computation of cross sections and Maxwell rate coefficients in the framework of the stepwise version of the Multichannel Quantum Defect Theory (MQDT). Cross sections and rate coefficients suitable for the modelling of the kinetics of HD{sup +} and BeH{sup +} in fusion plasmas and in the stellar atmospheres are presented and discussed. A very good agreement is found between our results for rotational transitions for HD{sup +} and other computations, as well as with experiment.

  6. Positron collisions with helium and alkaline earth-like atoms

    Campbell, C.P.

    1998-09-01

    This doctoral thesis is subdivided into: 1. Theory of positron collisions with helium and alkaline earth-like atoms, 2. Positron collisions with helium, magnesium, calcium, zinc, 3. Intercomparison of positron scattering by all those elements. The appendix of this work gives details of the numerical calculations and expands on the wavefunctions used

  7. Using fuzzy-trace theory to understand and improve health judgments, decisions, and behaviors: A literature review.

    Blalock, Susan J; Reyna, Valerie F

    2016-08-01

    Fuzzy-trace theory is a dual-process model of memory, reasoning, judgment, and decision making that contrasts with traditional expectancy-value approaches. We review the literature applying fuzzy-trace theory to health with 3 aims: evaluating whether the theory's basic distinctions have been validated empirically in the domain of health; determining whether these distinctions are useful in assessing, explaining, and predicting health-related psychological processes; and determining whether the theory can be used to improve health judgments, decisions, or behaviors, especially compared to other approaches. We conducted a literature review using PubMed, PsycINFO, and Web of Science to identify empirical peer-reviewed papers that applied fuzzy-trace theory, or central constructs of the theory, to investigate health judgments, decisions, or behaviors. Seventy nine studies (updated total is 94 studies; see Supplemental materials) were identified, over half published since 2012, spanning a wide variety of conditions and populations. Study findings supported the prediction that verbatim and gist representations are distinct constructs that can be retrieved independently using different cues. Although gist-based reasoning was usually associated with improved judgment and decision making, 4 sources of bias that can impair gist reasoning were identified. Finally, promising findings were reported from intervention studies that used fuzzy-trace theory to improve decision making and decrease unhealthy risk taking. Despite large gaps in the literature, most studies supported all 3 aims. By focusing on basic psychological processes that underlie judgment and decision making, fuzzy-trace theory provides insights into how individuals make decisions involving health risks and suggests innovative intervention approaches to improve health outcomes. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  8. Probability of satellite collision

    Mccarter, J. W.

    1972-01-01

    A method is presented for computing the probability of a collision between a particular artificial earth satellite and any one of the total population of earth satellites. The collision hazard incurred by the proposed modular Space Station is assessed using the technique presented. The results of a parametric study to determine what type of satellite orbits produce the greatest contribution to the total collision probability are presented. Collision probability for the Space Station is given as a function of Space Station altitude and inclination. Collision probability was also parameterized over miss distance and mission duration.

  9. Use of theory in computer-based interventions to reduce alcohol use among adolescents and young adults: a systematic review.

    Tebb, Kathleen P; Erenrich, Rebecca K; Jasik, Carolyn Bradner; Berna, Mark S; Lester, James C; Ozer, Elizabeth M

    2016-06-17

    Alcohol use and binge drinking among adolescents and young adults remain frequent causes of preventable injuries, disease, and death, and there has been growing attention to computer-based modes of intervention delivery to prevent/reduce alcohol use. Research suggests that health interventions grounded in established theory are more effective than those with no theoretical basis. The goal of this study was to conduct a literature review of computer-based interventions (CBIs) designed to address alcohol use among adolescents and young adults (aged 12-21 years) and examine the extent to which CBIs use theories of behavior change in their development and evaluations. This study also provides an update on extant CBIs addressing alcohol use among youth and their effectiveness. Between November and December of 2014, a literature review of CBIs aimed at preventing or reducing alcohol in PsychINFO, PubMed, and Google Scholar was conducted. The use of theory in each CBI was examined using a modified version of the classification system developed by Painter et al. (Ann Behav Med 35:358-362, 2008). The search yielded 600 unique articles, 500 were excluded because they did not meet the inclusion criteria. The 100 remaining articles were retained for analyses. Many articles were written about a single intervention; thus, the search revealed a total of 42 unique CBIs. In examining the use of theory, 22 CBIs (52 %) explicitly named one or more theoretical frameworks. Primary theories mentioned were social cognitive theory, transtheoretical model, theory of planned behavior and reasoned action, and health belief model. Less than half (48 %), did not use theory, but mentioned either use of a theoretical construct (such as self-efficacy) or an intervention technique (e.g., manipulating social norms). Only a few articles provided detailed information about how the theory was applied to the CBI; the vast majority included little to no information. Given the importance of theory in

  10. Use of theory in computer-based interventions to reduce alcohol use among adolescents and young adults: a systematic review

    Kathleen P. Tebb

    2016-06-01

    Full Text Available Abstract Background Alcohol use and binge drinking among adolescents and young adults remain frequent causes of preventable injuries, disease, and death, and there has been growing attention to computer-based modes of intervention delivery to prevent/reduce alcohol use. Research suggests that health interventions grounded in established theory are more effective than those with no theoretical basis. The goal of this study was to conduct a literature review of computer-based interventions (CBIs designed to address alcohol use among adolescents and young adults (aged 12–21 years and examine the extent to which CBIs use theories of behavior change in their development and evaluations. This study also provides an update on extant CBIs addressing alcohol use among youth and their effectiveness. Methods Between November and December of 2014, a literature review of CBIs aimed at preventing or reducing alcohol in PsychINFO, PubMed, and Google Scholar was conducted. The use of theory in each CBI was examined using a modified version of the classification system developed by Painter et al. (Ann Behav Med 35:358–362, 2008. Results The search yielded 600 unique articles, 500 were excluded because they did not meet the inclusion criteria. The 100 remaining articles were retained for analyses. Many articles were written about a single intervention; thus, the search revealed a total of 42 unique CBIs. In examining the use of theory, 22 CBIs (52 % explicitly named one or more theoretical frameworks. Primary theories mentioned were social cognitive theory, transtheoretical model, theory of planned behavior and reasoned action, and health belief model. Less than half (48 %, did not use theory, but mentioned either use of a theoretical construct (such as self-efficacy or an intervention technique (e.g., manipulating social norms. Only a few articles provided detailed information about how the theory was applied to the CBI; the vast majority included little

  11. Introduction to the theory and application of a unified Bohm criterion for arbitrary-ion-temperature collision-free plasmas with finite Debye lengths

    Kos, L.; Jelić, N.; Kuhn, S.; Tskhakaya, D. D.

    2018-04-01

    Tonks-Langmuir collision-free, plane-parallel discharge model [Phys. Rev. 34, 876 (1929)], however, with the ion-source temperature extended here from the original (zero) value to arbitrary high ones. In addition, it turns out, that the charge-density derivative (in the potential "space") with respect to the potential exhibits two characteristic points, i.e., potentials, namely the points of inflection and maximum of that derivative (in the potential space), which stay "fixed" at their respective potentials independent of the Debye length until it is kept fairly small. Plasma quasi-neutrality appears well satisfied up to the first characteristic point/potential, so we identify that one as the plasma edge (PE). Adopting the convention that the sheath is a region characterized by considerable electrostatic pressure (energy density), we identify the second characteristic point/potential as the sheath edge (SE). Between these points, the charge density increases from zero to a finite value. Thus, the interval between the PE and SE, with the "fixed" width (in the potential "space") of about one third of the electron temperature, will be named the plasma-sheath transition (PST). Outside the PST, the electrostatic-pressure term and its derivatives turn out to be nearly identical with each other, independent of the particular values of the ion temperature and Debye length. In contrast, an increase in Debye lengths from zero to finite values causes the location of the sonic point/potential (laying inside the PST) to shift from the PE (for vanishing Debye length) towards the SE, while at the same time, the absolute value of the corresponding ion-sound velocity slightly decreases. These shifts turn out to be manageable with employing the mathematical concept of the plasma-to-sheath transition (different from, but related to our natural PST concept), resulting in approximate, but sufficiently reliable semi-analytic expressions, which are functions of the ion temperature and Debye

  12. Self-management programs based on the social cognitive theory for Koreans with chronic disease: a systematic review.

    Jang, Yeonsoo; Yoo, Hyera

    2012-02-01

    Self-management programs based on social cognitive theory are useful to improve health care outcomes for patients with chronic diseases in Western culture. The purpose of this review is to identify and synthesize published research on the theory to enhance self-efficacy in disease management and examine its applicability to Korean culture regarding the learning strategies used. Ultimately, it was to identify the optimal use of these learning strategies to improve the self-efficacy of Korean patients in self-management of their hypertension and diabetic mellitus. The authors searched the Korean and international research databases from January 2000 to September 2009. Twenty studies were selected and reviewed. The most frequently used learning strategies of social cognitive theory was skill mastery by practice and feedback (N = 13), followed by social or verbal persuasion by group members (N = 7) and, however, observation learning and reinterpretation of symptoms by debriefing or discussion were not used any of the studies. Eight studies used only one strategy to enhance self-efficacy and six used two. A lack of consistency regarding the content and clinical efficacy of the self-efficacy theory-based self-management programs is found among the reviewed studies on enhancing self-efficacy in Koreans with hypertension and diabetes mellitus. Further research on the effectiveness of these theory-based self-management programs for patients with chronic diseases in Korea and other countries is recommended.

  13. The general practitioner's role in promoting physical activity to older adults: a review based on program theory.

    Hinrichs, Timo; Brach, Michael

    2012-02-01

    Positive influences of physical activity both on many chronic diseases and on preservation of mobility are well documented. But chronically ill or mobility restricted elderly living in their own homes are difficult to reach for interventions. The general practitioner's (GP) surgery offers one of the few opportunities to give advice for physical activity to those people. We used program theory to sound out knowledge on GP-centered physical activity counseling. The "conceptual theory" (evidence for training effects in old age) and the "implementation theory" (unique position of the GP) were reviewed narratively. The "action theory" (effects of GP counseling) was reviewed systematically. According to program theory, appropriate MeSH (Medical subject headings) concepts were Aged OR Aged, 80 and over (Target group), Physicians, Family OR Primary Health Care (Implementation/Setting), Counseling OR Patient Education as Topic OR Disease Management OR Health promotion (Intervention), Exercise OR Motor Activity OR Physical Fitness OR Sports (Determinants). The resulting six review papers (Pubmed, 2000-2009) were presented using the STARLITE mnemonic. Authors agree, that the GP plays a central role in the promotion of physical activity to elderly people, but there is conflicting evidence concerning counseling effectiveness. Utilizing behavioral change strategies and the collaboration between GPs and specialised professions are recommended and currently under research.

  14. [Intracranial collision tumor--A case report (author's transl)].

    Fukaya, T; Yoshida, J; Banno, T; Kageyama, N; Ito, M

    1976-06-01

    A 21-year-old man with nasopharyngeal tumor was first admitted to the Nagoya University Hospital on April 15, 1972. He had difficulty in speaking and swallowing, and developed double vision prior to admission. A soft and yellow tumor was found in the nasopharynx and revealed typical features of chordoma. The patient underwent Co60 irradiation after the operation. On January 25, 1973, the patient developed double vision of severe degree. Microscopic examination of the specimen which was obtained at the time of the second operation in February 9, 1973, disclosed a coexistence (collision) of chordoma and hemangioblastoma. The two different tumors were situated in juxtaposition on histological examination. Co60 irradiation was added during his second hospitalization. Three months after the second operation, he developed symptoms of meningitis and was hospitalized for the third time on June 3, 1973, at which time the tumor tissue extended through the right frontal and middle fossa. The third operation was done with frontal craniotomy and tumor was partially removed. The histological diagnosis was hemangioblastoma. Postoperatively the patient went downhill and died on September 19, 1973. The report of a collision tumor of intracranial chordoma and hemangioblastoma is not found in the previous literature. There have been many theories as to the origin of collision tumor. Some investigators have proposed that the existence of hyperplastic blood vessels within the glioblastoma is responsible for the collision tumor of sarcoma and glioblastoma. Since the advent of radiotherapy, several examples of sarcoma have been discovered at postmortem examination in patient irradiated for treatment of cerebral neoplasm, both gliogeneous and nongliogenous, suggesting a possible relationship between the tumor and the radiation therapy. In our case, the chordoma showed neither hyperplastic blood vessels nor malignant pattern on histological examination. It was suspected that post

  15. Review of mechanisms, methods, and theory for determining recharge to shallow aquifers in North Dakota

    Horak, W.F.

    1988-01-01

    Effective management of ground-water resources requires knowledge of all components of the water budget for the aquifer of interest. Efforts to simulate ground-water flow prior to development and the effects of proposed pumping in several of North Dakota's shallow glacial aquifers have been hindered by the lack of reliable estimates of ground-water recharge. This study was done to (1) review the methods that have been used to measure recharge, (2) review the theory of unsaturated flow and the methods for characterizing the physical properties of unsaturated media, (3) consider the relative merits of a rigorous data-intensive approach versus an estimation approach to the study of recharge, and (4) review past and current agronomic research in North Dakota for applicability of the research and the data generated to the study of recharge.Direct, quantitative techniques for evaluating recharge are rarely applied. The theory for computing fluxes in unsaturated media is well established and numerous physics-based models that effectively implement the theory are available, but the data required for the models generally are lacking. Many parametric approaches have been developed to avoid the large data requirements of the physics-based approaches for analyzing flow in the unsaturated zone. However, the parametric approaches normally include fitting coefficients that must be calibrated for every study site, thereby detracting from the general utility of the parametric approach. The functional relation of matric potential to moisture content is required for physics-based soil-water models, whether analytic or numeric. Laboratory methods to determine these relations are tedious, costly, and may not give results representative of the soils as they occur in the field. Many models have been proposed to estimate the moisture-characteristic curve and hydraulic-conductivity function from basic soil properties, but none yield results that are universally satisfactory. In situ

  16. Pediatric psychotropic medication initiation and adherence: a literature review based on social exchange theory.

    Hamrin, Vanya; McCarthy, Erin M; Tyson, Veda

    2010-08-01

    Psychotropic medication initiation and adherence is an identified problem. This literature review explores factors that determine families' decisions to initiate, sustain, or discontinue use of psychotropic medication in children and adolescents. Social exchange theory is used as a framework to explore decisions to initiate and adhere to psychotropic medications. Contributing factors related to psychotropic medication initiation, adherence, and discontinuation are explored. Themes in the literature encompassing costs and benefits of psychotropic medication adherence include family experiences with adverse effects, previous psychotropic medication experience, medication psychoeducation, stigma, societal views about psychotropic medication, particular diagnosis, the effect of comorbid diagnosis on adherence, attitudes and beliefs about medication by both children and parents, and relationships with the provider. The impact of family demographics including parent gender, age of the child, ethnicity, and parent educational level on psychotropic medication adherence is evaluated. International and U.S. studies from Medline, Cumulative Index for Nursing and Allied Health Literature and PsychInfo evaluating medication initiation and adherence in the pediatric psychiatric population and social exchange theory was incorporated from relevant textbook resources. Rewards experienced from medication treatment include improvement in symptoms, school performance and family relationships, and reduced level of parenting stress. Identified costs include impact of adverse side effects, social stigma, lack of response, fears of addiction, and changing the child's personality. Acceptance of the diagnosis influences adherence while medication education has varying effects. Families' attitudes, beliefs and perceptions about psychiatric illness and treatment play a large role in medication treatment decisions. A trusting provider relationship has a positive effect on adherence

  17. Ultrarelativistic heavy ion collisions Theoretical overview

    Blaizot, Jean-Paul

    2006-01-01

    This is a short review of some theoretical aspects of the physics of ultra-relativistic heavy ion collisions. I review the main properties of the QCD phase diagram and recent developments in the physics of high gluon densities in the hadronic wavefunctions at high energy. Then I comment salient results obtained at RHIC

  18. Physical activity during pregnancy and the role of theory in promoting positive behavior change: A systematic review

    Erika L. Thompson

    2017-06-01

    Conclusion: This systematic review synthesized the literature on theoretical constructs related to PA during pregnancy. Interpersonal, community, and societal levels remain understudied. Future research should employ theory-driven multi-level determinants of PA to reflect the interacting factors influencing PA during this critical period in the life course.

  19. A review of experimental results obtained in Au-Au collisions at the RHIC-BNL energies using BRAHMS experimental set-up

    Jipa, Alexandru

    2003-01-01

    Ultrarelativistic heavy ion collisions are useful tools to investigate highly excited dense nuclear matter. At sufficiently high temperature, nuclear matter is expected to undergo a phase transition to quark-gluon plasma. Therefore, new experiments have been proposed to investigate the behaviour of the highly excited dense nuclear matter. One of the experiments performed at the Relativistic Heavy Ion Collider from Brookhaven National Laboratory is the BRAHMS Experiment. In the three running years many experimental data have been obtained. These data permitted to establish significant experimental results on charged pion, charged kaon, proton and antiproton production in Au-Au collisions at 130 A GeV and 200 A GeV in CMS. The present work summarizes the main experimental results on charged particle multiplicities, rapidity distributions, momentum spectra, antiparticle to particle ratios and connects these results with some interesting physical quantities. Their dependencies on the available energies in the CMS in similar collisions are included. Interesting behaviours with the increase of this energy are reported. The most interesting are related to the behaviour of the antiproton to proton ratio on the collision centrality and on the available energy in the centre of mass system, the strangeness production, Coulomb repulsion and slope parameters of the momentum spectra. A few new steps in the knowledge of the behaviour of the highly excited and dense nuclear matter can be reported. (authors)

  20. BOOK REVIEW: Quantum Field Theory in a Nutshell (2nd edn) Quantum Field Theory in a Nutshell (2nd edn)

    Peskin, Michael E.

    2011-04-01

    Anthony Zee is not only a leading theoretical physicist but also an author of popular books on both physics and non-physics topics. I recommend especially `Swallowing Clouds', on Chinese cooking and its folklore. Thus, it is not surprising that his textbook has a unique flavor. Derivations end, not with `QED' but with exclamation points. At the end of one argument, we read `Vive Cauchy!', in another `the theorem practically exudes generality'. This is quantum field theory taught at the knee of an eccentric uncle; one who loves the grandeur of his subject, has a keen eye for a slick argument, and is eager to share his repertoire of anecdotes about Feynman, Fermi, and all of his heroes. A one-page section entitled `Electric Charge' illustrates the depth and tone of the book. In the previous section, Zee has computed the Feynman diagram responsible for vacuum polarization, in which a photon converts briefly to a virtual electron-positron pair. In the first paragraph, he evaluates this expression, giving a concrete formula for the momentum-dependence of the electric charge, an important effect of quantum field theory. Next, he dismisses other possible diagrams that could affect the value of the electric charge. Most authors would give an explicit argument that these diagrams cancel, but for Zee it is more important to make the point that this result is expected and, from the right point of view, obvious. Finally, he discusses the implications for the relative size of the charges of the electron and the proton. If the magnitudes of charges are affected by interactions, and the proton has strong interactions but the electron does not, can it make sense that the charges of the proton and the electron are exactly equal and opposite? The answer is yes, and also that this was the real point of the whole derivation. The book takes on the full range of topics covered in typical graduate course in quantum field theory, and many additional topics: magnetic monopoles, solitons

  1. Fast ion-atom and ion-molecule collisions

    2013-01-01

    The principal goal of this book is to provide state-of-the art coverage of the non-relativistic three- and four-body theories at intermediate and high energy ion-atom and ion-molecule collisions. The focus is on the most frequently studied processes: electron capture, ionization, transfer excitation and transfer ionization. The content is suitable both for graduate students and experienced researchers. For these collisions, the literature has seen enormous renewal of activity in the development and applications of quantum-mechanical theories. This subject is of relevance in several branches of science and technology, like accelerator-based physics, the search for new sources of energy and high temperature fusion of light ions. Other important applications are in life sciences via medicine, where high-energy ion beams are used in radiotherapy for which a number of storage ring accelerators are in full operation, under construction or planned to be built worldwide. Therefore, it is necessary to review this fiel...

  2. Theory of Mind in Depressive Disorders: A Review of the Literature.

    Berecz, Hajnalka; Tényi, Tamás; Herold, Róbert

    Theory of mind (ToM) is the ability to infer the mental states of others in order to understand and predict their behaviour. This ability is thought to be essential to social functioning and interpersonal relationships. As major depression is characterized by considerable social and interpersonal difficulties, exploration of the quality of ToM functioning can be particularly relevant in this and in related disorders. We aim to review the current state of research on ToM in depressive disorders in order to find out the extent to which ToM impairment is associated with these illnesses. An internet database search was carried out to collect all publications on the subject. A total of 32 publications in English met our inclusion criteria: (a) 17 studies on ToM in major depression, (b) 4 studies on ToM in psychotic depression, (c) 3 studies on ToM in dysphoria or mild depression, (d) 4 studies on ToM in euthymic major depression, (e) 2 studies on ToM in chronic versus episodic depression, and (f) 2 studies on ToM in another psychiatric disorder with comorbid major depression. Despite an increased interest in the research of the topic in recent years, no firm conclusions can be drawn, as the reviewed articles present some conflicting results. Acutely depressed patients have been found to be impaired on tasks involving both ToM social-perceptual and social-cognitive components. On the other hand, a number of studies have not reported significant between-group differences between depressed patients and healthy controls or have found minimal differences. Further research is needed in order to confirm and extend these results. © 2016 S. Karger AG, Basel.

  3. The interpersonal theory of suicide: A systematic review and meta-analysis of a decade of cross-national research.

    Chu, Carol; Buchman-Schmitt, Jennifer M; Stanley, Ian H; Hom, Melanie A; Tucker, Raymond P; Hagan, Christopher R; Rogers, Megan L; Podlogar, Matthew C; Chiurliza, Bruno; Ringer, Fallon B; Michaels, Matthew S; Patros, Connor H G; Joiner, Thomas E

    2017-12-01

    Over the past decade, the interpersonal theory of suicide has contributed to substantial advances in the scientific and clinical understanding of suicide and related conditions. The interpersonal theory of suicide posits that suicidal desire emerges when individuals experience intractable feelings of perceived burdensomeness and thwarted belongingness and near-lethal or lethal suicidal behavior occurs in the presence of suicidal desire and capability for suicide. A growing number of studies have tested these posited pathways in various samples; however, these findings have yet to be evaluated meta-analytically. This paper aimed to (a) conduct a systematic review of the unpublished and published, peer-reviewed literature examining the relationship between interpersonal theory constructs and suicidal thoughts and behaviors, (b) conduct meta-analyses testing the interpersonal theory hypotheses, and (c) evaluate the influence of various moderators on these relationships. Four electronic bibliographic databases were searched through the end of March, 2016: PubMed, Medline, PsycINFO, and Web of Science. Hypothesis-driven meta-analyses using random effects models were conducted using 122 distinct unpublished and published samples. Findings supported the interpersonal theory: the interaction between thwarted belongingness and perceived burdensomeness was significantly associated with suicidal ideation; and the interaction between thwarted belongingness, perceived burdensomeness, and capability for suicide was significantly related to a greater number of prior suicide attempts. However, effect sizes for these interactions were modest. Alternative configurations of theory variables were similarly useful for predicting suicide risk as theory-consistent pathways. We conclude with limitations and recommendations for the interpersonal theory as a framework for understanding the suicidal spectrum. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  4. Electron detachment by H- + H- collisions

    Chibisov, M.I.; Yavlinskii, Yu.N.

    1994-01-01

    The autoionization channels for electrons detachment in collisions of two negative hydrogen ions in the energy range 300 - 500 eV and > 500 eV are investigated. In small energy range at large inter-ion distances the asymptotic approximation is used; at high energies - perturbation theory and classical motion are used. 18 refs., 3 figs

  5. Fan Affinity Laws from a Collision Model

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour…

  6. An introductory review of information theory in the context of computational neuroscience.

    McDonnell, Mark D; Ikeda, Shiro; Manton, Jonathan H

    2011-07-01

    This article introduces several fundamental concepts in information theory from the perspective of their origins in engineering. Understanding such concepts is important in neuroscience for two reasons. Simply applying formulae from information theory without understanding the assumptions behind their definitions can lead to erroneous results and conclusions. Furthermore, this century will see a convergence of information theory and neuroscience; information theory will expand its foundations to incorporate more comprehensively biological processes thereby helping reveal how neuronal networks achieve their remarkable information processing abilities.

  7. A review of predictive nonlinear theories for multiscale modeling of heterogeneous materials

    Matouš, Karel, E-mail: kmatous@nd.edu [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556 (United States); Geers, Marc G.D.; Kouznetsova, Varvara G. [Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven (Netherlands); Gillman, Andrew [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2017-02-01

    Since the beginning of the industrial age, material performance and design have been in the midst of innovation of many disruptive technologies. Today's electronics, space, medical, transportation, and other industries are enriched by development, design and deployment of composite, heterogeneous and multifunctional materials. As a result, materials innovation is now considerably outpaced by other aspects from component design to product cycle. In this article, we review predictive nonlinear theories for multiscale modeling of heterogeneous materials. Deeper attention is given to multiscale modeling in space and to computational homogenization in addressing challenging materials science questions. Moreover, we discuss a state-of-the-art platform in predictive image-based, multiscale modeling with co-designed simulations and experiments that executes on the world's largest supercomputers. Such a modeling framework consists of experimental tools, computational methods, and digital data strategies. Once fully completed, this collaborative and interdisciplinary framework can be the basis of Virtual Materials Testing standards and aids in the development of new material formulations. Moreover, it will decrease the time to market of innovative products.

  8. Review. Advantages and disadvantages of control theories applied in greenhouse climate control systems

    Duarte-Galvan, C.; Torres-Pacheco, I.; Guevara-Gonzalez, R. G.; Romero-Troncoso, R. J.; Contreras-Medina, L. M.; Rios-Alcaraz, M. A.; Millan-Almaraz, J. R.

    2012-07-01

    Today agriculture is changing in response to the requirements of modern society, where ensuring food supply through practices such as water conservation, reduction of agrochemicals and the required planted surface, which guarantees high quality crops are in demand. Greenhouses have proven to be a reliable solution to achieve these goals; however, a greenhouse as a means for protected agriculture has the potential to lead to serious problems. The most of these are related to the inside greenhouse climate conditions where controlling the temperature and relative humidity (RH) are the main objectives of engineering. Achieving appropriate climate conditions to ensure high yield and quality crops reducing energy consumption have been the objective of investigations for some time. Different schemes in control theories have been applied in this field to solve the aforementioned problems. Therefore, the objective of this paper is to present a review of different control techniques applied in protected agriculture to manage greenhouse climate conditions, presenting advantages and disadvantages of developed control platforms in order to suggest a design methodology according to results obtained from different investigations. (Author) 64 refs.

  9. Searches for T-odd interactions in nuclear processes: Review of the theory

    Herczeg, P.

    1995-01-01

    CP-violation has been seen so far only in the neutral kaon system. Its origin is still unknown. If the CPT theorem holds, as is the case in gauge theories, CP-violating interactions violate also time reversal (T) invariance. Regarding the CPT theorem there is some experimental evidence that the interaction responsible for the observed CP-violation violates T-invariance. The observed CP-violation may just be a manifestation of the weak interaction of the Standard Model (SM), or it is due to an interaction beyond the SM. In both cases some of the new interactions may give rise to observable CP-violation where the SM contribution is invisible. This underlines the importance of searching for CP-violating and T-violating effects in many processes. In this talk we shall review what has been learned about T-violating interactions that can be probed in nuclear processes from experiments outside of and within nuclear physics, and consider the role of nuclear physics experiments in obtaining further information on such interactions

  10. A review of predictive nonlinear theories for multiscale modeling of heterogeneous materials

    Matouš, Karel; Geers, Marc G.D.; Kouznetsova, Varvara G.; Gillman, Andrew

    2017-01-01

    Since the beginning of the industrial age, material performance and design have been in the midst of innovation of many disruptive technologies. Today's electronics, space, medical, transportation, and other industries are enriched by development, design and deployment of composite, heterogeneous and multifunctional materials. As a result, materials innovation is now considerably outpaced by other aspects from component design to product cycle. In this article, we review predictive nonlinear theories for multiscale modeling of heterogeneous materials. Deeper attention is given to multiscale modeling in space and to computational homogenization in addressing challenging materials science questions. Moreover, we discuss a state-of-the-art platform in predictive image-based, multiscale modeling with co-designed simulations and experiments that executes on the world's largest supercomputers. Such a modeling framework consists of experimental tools, computational methods, and digital data strategies. Once fully completed, this collaborative and interdisciplinary framework can be the basis of Virtual Materials Testing standards and aids in the development of new material formulations. Moreover, it will decrease the time to market of innovative products.

  11. A review of predictive nonlinear theories for multiscale modeling of heterogeneous materials

    Matouš, Karel; Geers, Marc G. D.; Kouznetsova, Varvara G.; Gillman, Andrew

    2017-02-01

    Since the beginning of the industrial age, material performance and design have been in the midst of innovation of many disruptive technologies. Today's electronics, space, medical, transportation, and other industries are enriched by development, design and deployment of composite, heterogeneous and multifunctional materials. As a result, materials innovation is now considerably outpaced by other aspects from component design to product cycle. In this article, we review predictive nonlinear theories for multiscale modeling of heterogeneous materials. Deeper attention is given to multiscale modeling in space and to computational homogenization in addressing challenging materials science questions. Moreover, we discuss a state-of-the-art platform in predictive image-based, multiscale modeling with co-designed simulations and experiments that executes on the world's largest supercomputers. Such a modeling framework consists of experimental tools, computational methods, and digital data strategies. Once fully completed, this collaborative and interdisciplinary framework can be the basis of Virtual Materials Testing standards and aids in the development of new material formulations. Moreover, it will decrease the time to market of innovative products.

  12. Quantitative safety goals for nuclear power plants: critical review and reformulation within a unified theory

    Munera, H.A.; Yadigaroglu, G.

    1988-01-01

    The first part of the paper critically reviews some of the adopted and/or proposed probabilistic safety goals and criteria in several countries. Some of the difficulties identified are:- Lack of an adequate delimitation of the scope of the non-deterministic choice problem. Consequently, the main components of the problem-probabilities and consequences-are not clearly defined. As a further consequence there is no unified treatment, including notation and terminology, for concepts like risk, probability, frequency, utility, risk-aversion, limit-line, etc. - The theoretical justifications and/or implications of limit-lines are not always fully understood. As a result three very different classes of limit-lines have emerged. The theoretical limitations of limit-lines are not always fully realized, leading to an over-emphasis in that approach and thus preventing the development of alternative methodologies. In the second part of the paper theoretical methods are indicated to compare probability distributions already existing in other disciplines, and a unified methodology to formulate probabilistic safety criteria is briefly described. The proposed theory gives due consideration to the whole probability distribution, and contains both limit-line concepts and global risk indices. The latter can easily incorporate regulatory and/or societal value-judgements, for instance risk-aversion. (author)

  13. Review of On the Theory and Practice of Archaeological Computing [Book

    Julian D. Richards

    2001-01-01

    Full Text Available It might seem rather old-fashioned that, at the start of the new millennium, a book on archaeological computing should be published solely in traditional hard copy format. However, whilst the black-and-white screen shots would no doubt have been improved by colour representation, this book generally succeeds as a paper volume. That it does so is due, at least in part, to the fact that the emphasis is not so much on the technology and how to do it, but rather on how the technology affects the discipline, justifying Internet Archaeology to vary its normal policy of only reviewing electronic publications. The book began as a conference session on the impact of computers on archaeological theory and practice, held at the 4th World Archaeological Congress in Cape Town in January 1999. It comprises nine papers, plus a short introduction by the editors, in which they note that their volume needs to be seen in the tradition of Cooper and Richards (1985 and Reilly and Rahtz (1992, rather than the more methodological and positivist approach adopted by many of the papers published in the annual proceedings of the Computer Applications in Archaeology (CAA Conference. That some eight years have passed since the last survey indicates how timely this latest analysis is.

  14. Changing delay discounting in the light of the competing neurobehavioral decision systems theory: a review.

    Koffarnus, Mikhail N; Jarmolowicz, David P; Mueller, E Terry; Bickel, Warren K

    2013-01-01

    Excessively devaluing delayed reinforcers co-occurs with a wide variety of clinical conditions such as drug dependence, obesity, and excessive gambling. If excessive delay discounting is a trans-disease process that underlies the choice behavior leading to these and other negative health conditions, efforts to change an individual's discount rate are arguably important. Although discount rate is often regarded as a relatively stable trait, descriptions of interventions and environmental manipulations that successfully alter discount rate have begun to appear in the literature. In this review, we compare published examples of procedures that change discount rate and classify them into categories of procedures, including therapeutic interventions, direct manipulation of the executive decision-making system, framing effects, physiological state effects, and acute drug effects. These changes in discount rate are interpreted from the perspective of the competing neurobehavioral decision systems theory, which describes a combination of neurological and behavioral processes that account for delay discounting. We also suggest future directions that researchers could take to identify the mechanistic processes that allow for changes in discount rate and to test whether the competing neurobehavioral decision systems view of delay discounting is correct. © Society for the Experimental Analysis of Behavior.

  15. A review of Education and Social Media using functionalist and conflict theories of educational purposes

    Cian, Heidi; Amann, Holly

    2017-11-01

    Education and Social Media: Toward a Digital Future (2016), edited by Christine Greenhow, Julia Sonnevend, and Colin Agur, is a compilation of essays by leading contributors to the digital and social media movement in education. The chapters within this volume provide a granular look at the current landscape of how digital media is utilized across educational levels, fields of study, and geographic areas. The book is divided into three sections discussing the emerging use of social media in education, challenges in its implementation, and potential directions as tech-based education continues to evolve. In this review, we situate the ideas presented in Education and Social Media in the functionalist and conflict theories of educational perspective to further illuminate the potential of digital learning in supporting increased access to education for marginalized student populations. We discuss how these competing views are both given voice in Education and Social Media, prompting the reader to critically reflect on advantages and dangers presented by increased use of technological platforms in educational settings. Topics discussed include online universities, peer-developed curriculum, and differential use of technology based on school socioeconomic demographics. We also suggest areas that have emerged in need of further discussion since the book's publication.

  16. A review of Education and Social Media using conflict and functionalist theories

    Cian, Heidi; Amann, Holly

    2017-09-01

    Education and Social Media: Toward a Digital Future (2016), edited by Christine Greenhow, Julia Sonnevend, and Colin Agur, is a compilation of essays by leading contributors to the digital and social media movement in education. The chapters within this volume provide a granular look at the current landscape of how digital media is utilized across educational levels, fields of study, and geographic areas. The book is divided into three sections discussing the emerging use of social media in education, challenges in its implementation, and potential directions as tech-based education continues to evolve. In this review, we situate the ideas presented in Education and Social Media in the functionalist and conflict theories of educational perspective to further illuminate the potential of digital learning in supporting increased access to education for marginalized student populations. We discuss how these competing views are both given voice in Education and Social Media, prompting the reader to critically reflect on advantages and dangers presented by increased use of technological platforms in educational settings. Topics discussed include online universities, peer-developed curriculum, and differential use of technology based on school socioeconomic demographics. We also suggest areas that have emerged in need of further discussion since the book's publication.

  17. Work Design Theory: A Review and Critique with Implications for Human Resource Development

    Torraco, Richard J.

    2005-01-01

    Six theoretical perspectives on work design are examined for their contributions to our understanding of how work is organized and designed in organizations: sociotechnical systems theory, process improvement, adaptive structuration theory, the job characteristics model, technostructural change models, and activity theory. A critique of these…

  18. 76 FR 62421 - Submission for OMB Review; Comment Request; A Generic Submission for Theory Development and...

    2011-10-07

    ...; Comment Request; A Generic Submission for Theory Development and Validation (NCI) SUMMARY: Under the... control number. Proposed Collection: Title: A Generic Submission for Theory Development and Validation...), to conduct and support behavioral research informed by and informing theory. Formative research in...

  19. Using attachment theory to inform the design and delivery of mental health services: a systematic review of the literature.

    Bucci, Sandra; Roberts, Nicola H; Danquah, Adam N; Berry, Katherine

    2015-03-01

    The aim of this review was to propose and describe the design and delivery of an attachment-informed general mental health service. We systematically searched the PsycINFO, MEDLINE, Web of Knowledge, COPAC, CINAHL, and Science Direct databases from 1960 to 2013. We also searched reference lists of relevant papers and directly contacted authors in the field. Literature describing attachment theory and its applicability in designing and delivering general mental health services was synthesized using thematic analysis. Papers published in English, books or chapters in edited books that described applying attachment theory in designing and delivering mental health services for adults and adolescents were included in the review. Of the 1,105 articles identified, 14 met inclusion criteria for the review. Eight key themes, and four subthemes, were extracted and organized to reflect the experience of a service user moving through the mental health system. Key themes extracted were as follows: service policy and evaluation; referrals; assessment and formulation; intervention; support for staff; support for carers; moving on; and potential service benefits. Papers reviewed suggested that service users with severe mental health problems have attachment needs that should be met in general mental health services. Attachment theory provides a useful framework to inform the design and delivery of general mental health services. The resource implications for services are discussed, as are limitations of the review and recommendations for future research. Attachment theory should be used to inform the design and delivery of general mental health services. Mental health services should evaluate the extent to which they meet service users' attachment needs. Attachment-informed mental health services should assess outcomes, including cost-effectiveness over time. Papers included in this review focus on long-stay residential care or secure services and there is a limited experimental

  20. Exercise, physical activity, and self-determination theory: A systematic review

    Teixeira Pedro J

    2012-06-01

    Full Text Available Abstract Background Motivation is a critical factor in supporting sustained exercise, which in turn is associated with important health outcomes. Accordingly, research on exercise motivation from the perspective of self-determination theory (SDT has grown considerably in recent years. Previous reviews have been mostly narrative and theoretical. Aiming at a more comprehensive review of empirical data, this article examines the empirical literature on the relations between key SDT-based constructs and exercise and physical activity behavioral outcomes. Methods This systematic review includes 66 empirical studies published up to June 2011, including experimental, cross-sectional, and prospective studies that have measured exercise causality orientations, autonomy/need support and need satisfaction, exercise motives (or goal contents, and exercise self-regulations and motivation. We also studied SDT-based interventions aimed at increasing exercise behavior. In all studies, actual or self-reported exercise/physical activity, including attendance, was analyzed as the dependent variable. Findings are summarized based on quantitative analysis of the evidence. Results The results show consistent support for a positive relation between more autonomous forms of motivation and exercise, with a trend towards identified regulation predicting initial/short-term adoption more strongly than intrinsic motivation, and intrinsic motivation being more predictive of long-term exercise adherence. The literature is also consistent in that competence satisfaction and more intrinsic motives positively predict exercise participation across a range of samples and settings. Mixed evidence was found concerning the role of other types of motives (e.g., health/fitness and body-related, and also the specific nature and consequences of introjected regulation. The majority of studies have employed descriptive (i.e., non-experimental designs but similar results are found across

  1. Exercise, physical activity, and self-determination theory: A systematic review

    2012-01-01

    Background Motivation is a critical factor in supporting sustained exercise, which in turn is associated with important health outcomes. Accordingly, research on exercise motivation from the perspective of self-determination theory (SDT) has grown considerably in recent years. Previous reviews have been mostly narrative and theoretical. Aiming at a more comprehensive review of empirical data, this article examines the empirical literature on the relations between key SDT-based constructs and exercise and physical activity behavioral outcomes. Methods This systematic review includes 66 empirical studies published up to June 2011, including experimental, cross-sectional, and prospective studies that have measured exercise causality orientations, autonomy/need support and need satisfaction, exercise motives (or goal contents), and exercise self-regulations and motivation. We also studied SDT-based interventions aimed at increasing exercise behavior. In all studies, actual or self-reported exercise/physical activity, including attendance, was analyzed as the dependent variable. Findings are summarized based on quantitative analysis of the evidence. Results The results show consistent support for a positive relation between more autonomous forms of motivation and exercise, with a trend towards identified regulation predicting initial/short-term adoption more strongly than intrinsic motivation, and intrinsic motivation being more predictive of long-term exercise adherence. The literature is also consistent in that competence satisfaction and more intrinsic motives positively predict exercise participation across a range of samples and settings. Mixed evidence was found concerning the role of other types of motives (e.g., health/fitness and body-related), and also the specific nature and consequences of introjected regulation. The majority of studies have employed descriptive (i.e., non-experimental) designs but similar results are found across cross

  2. Inclusive cross sections in AA collisions at high energies

    Braun, M.A.

    1988-01-01

    Inclusive cross sections in AA collisions at high energies are considered in the Glauber multiple scattering theory taking into account many-nucleon collisions. Correspondence is found between the AA amplitude and the effective action of the two-dimensional quantum field theory with exponential interaction. The tree and one-loop contributions are calculated in this formalism. The rules are derived, which relate the absorption part of the AA-collision amplitudes associated with various inclusive cross sections to the absorption parts of NN amplitudes. These rules generalize the well-known Agranowsky-Gribov-Kanchelli rules for hh and hA collisions. Formulas are written for single and double inclusive cross sections in AA collisions

  3. Credible Leadership-In the Eyes of the Follower: A Historical Review of Leadership Theory throughout the Twentieth Century in the United States

    Hoffman, Sharon C.

    2008-01-01

    The purpose of this historical review was to trace the credible leadership construct of trustworthiness, integrity, honesty, and consistency in leadership theory development during the last 100 years in the United States. Theory focus, key U.S. pivotal events, and follower importance influenced the construct's occurrence in leadership theory. …

  4. BOOK REVIEW: Many-Body Quantum Theory in Condensed Matter Physics—An Introduction

    Logan, D. E.

    2005-02-01

    fifty pages of the book, are devoted to electron transport in mesoscopic systems; the one on interacting systems is preceded by a brief account of equation of motion techniques a relative rarity in a general text, used here to provide background to subsequent discussion of the Coulomb blockade in quantum dots. So does it work, and will it find a niche beside other established, wide ranging texts? On the whole I think the answer has to be yes. To begin with, the book is well organised and user-friendly, which must surely appeal to students (and their mentors). The chapters are typically bite-sized and digestible. Each is accompanied by a summary/outlook, which in doing just that attempts to place the specific topic in a wider context, together with a set of problems that illustrate, and in many cases expand substantially on, the basic subject matter. A particularly healthy feature of the book is the extent to which the authors have sought where possible to include physical and/or material applications of basic theory, thereby enlivening old material and enhancing appreciation of the new. The first chapter on the electron gas, for example, introduces the reader to a range of material examples, including 2D heterostructures, carbon nanotubes and quantum dots. A chapter on the formalism of Green's functions takes time out to explain how the single-particle spectral function can be measured by tunnelling spectroscopy, while discussion of impurity scattering and conductivity is refreshed by consideration of weak localization in bulk and mesoscopic systems, and the phenomenon of universal conductance fluctuations. And so on: in a text that could readily descend to the purely formal, the authors have clearly taken seriously the task of incorporating relevant, topical applications of the underlying theory. In a book as wide ranging as this any reviewer is of course bound to perceive the occasional deficiency. I felt for example that some aspects of the discussion of conductance

  5. Collision tumor of the thyroid: follicular variant of papillary carcinoma and squamous carcinoma

    Kane Subhadra V

    2006-09-01

    Full Text Available Abstract Background Collision tumors of the thyroid gland are a rare entity. We present a case of a follicular variant of papillary carcinoma and squamous carcinoma in the thyroid. To the best of our knowledge, this is the first documentation of a collision tumor with a papillary carcinoma and a squamous carcinoma within the thyroid gland. The clinicopathological features and immunohistochemical profile are reported. The theories of origin, epidemiology and management are discussed with a literature review. Case presentation A 65 year old woman presented with a large thyroid swelling of 10 years duration and with swellings on the back and scalp which were diagnosed to be a follicular variant of papillary thyroid carcinoma with metastasis. Clinical examination, radiology and endoscopy ruled out any other abnormality of the upper aerodigestive tract. The patient was treated surgically with a total thyroidectomy with central compartment clearance and bilateral selective neck dissections. The histopathology revealed a collision tumor with components of both a follicular variant of papillary carcinoma and a squamous carcinoma. Immunohistochemical analysis confirmed the independent origin of these two primary tumors. Adjuvant radio iodine therapy directed toward the follicular derived component of the thyroid tumor and external beam radiotherapy for the squamous component was planned. Conclusion Collision tumors of the thyroid gland pose a diagnostic as well as therapeutic challenge. Metastasis from distant organs and contiguous primary tumors should be excluded. The origins of squamous cancer in the thyroid gland must be established to support the true evolution of a collision tumor and to plan treatment. Treatment for collision tumors depends upon the combination of primary tumors involved and each component of the combination should be treated like an independent primary. The reporting of similar cases with longer follow-up will help define the

  6. Hadron-nucleus collisions

    Strugalski, Z.

    1981-01-01

    Qualitative picture of high energy hadron-nucleus collision process, emerging from the analysis of experimental data, is presented. Appropriate description procedure giving a possibility of reproducing various characteristics of this process in terms of the data on elementary hadron-nucleon interaction is proposed. Formula reproducing hadron-nucleus collision cross sections is derived. Inelastic collision cross sections for pion-nucleus and proton-nucleus reactions at wide energy interval are calculated for Pb, Ag, and Al targets. A-dependence of cross sections for pion-nucleus and proton-nucleus collisions at nearly 50 GeV/c momentum were calculated and compared with existing experimental data. Energy dependence of cross sections for hadron-nucleus collisions is determined simply by energy dependence of corresponding cross sections for hadron-nucleon collisions; A-dependence is determined simply by nuclear sizes and nucleon density distributions in nuclei

  7. The effect of theory-based interventions on physical activity participation among overweight/obese individuals: a systematic review.

    Bélanger-Gravel, A; Godin, G; Vézina-Im, L-A; Amireault, S; Poirier, P

    2011-06-01

    Little attention has been paid to the evaluation of the long-term impact of theory-based interventions on physical activity participation among overweight/obese individuals after the interventions have ended. The primary aim of this systematic review was to investigate the long-term effectiveness of theory-based interventions increasing physical activity and identify the most effective techniques for behaviour change among overweight/obese individuals. The secondary aim was to investigate the effect of these interventions on theoretical variables. Eighteen studies were reviewed. Among these studies, three reported significant short-term and two long-term effects of interventions on physical activity participation. Most of the studies observed a significant short- or long-term effect of time on this behaviour. Theoretical frameworks most often applied included the Behavioural Model and the Social Learning/Cognitive Theory. However, few of the studies reported any impact on theoretical variables. The most prevalent techniques consisted of providing opportunities for social comparison and instruction as well as self-monitoring. Leading techniques differentiating the experimental group from the control group included prompting practice and intentions formation and barriers identification. Although the combination of these three techniques appears successful, the long-term impact of theory-based interventions remains ambiguous. © 2010 The Authors. obesity reviews © 2010 International Association for the Study of Obesity.

  8. Chirality in molecular collision dynamics

    Lombardi, Andrea; Palazzetti, Federico

    2018-02-01

    Chirality is a phenomenon that permeates the natural world, with implications for atomic and molecular physics, for fundamental forces and for the mechanisms at the origin of the early evolution of life and biomolecular homochirality. The manifestations of chirality in chemistry and biochemistry are numerous, the striking ones being chiral recognition and asymmetric synthesis with important applications in molecular sciences and in industrial and pharmaceutical chemistry. Chiral discrimination phenomena, due to the existence of two enantiomeric forms, very well known in the case of interaction with light, but still nearly disregarded in molecular collision studies. Here we review some ideas and recent advances about the role of chirality in molecular collisions, designing and illustrating molecular beam experiments for the demonstration of chiral effects and suggesting a scenario for a stereo-directional origin of chiral selection.

  9. Theories Applied to m-Health Interventions for Behavior Change in Low- and Middle-Income Countries: A Systematic Review.

    Cho, Yoon-Min; Lee, Seohyun; Islam, Sheikh Mohammed Shariful; Kim, Sun-Young

    2018-02-13

    Recently there has been dramatic increase in the use of mobile technologies for health (m-Health) in both high and low- and middle-income countries (LMICs). However, little is known whether m-Health interventions in LMICs are based on relevant theories critical for effective implementation of such interventions. This review aimed to systematically identify m-Health studies on health behavioral changes in LMICs and to examine how each study applied behavior change theories. A systematic review was conducted using the standard method from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. By searching electronic databases (MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials [CENTRAL]), we identified eligible studies published in English from inception to June 30, 2017. For the identified m-Health studies in LMICs, we examined their theoretical bases, use of behavior change techniques (BCTs), and modes of delivery. A total of 14 m-Health studies on behavioral changes were identified and, among them, only 5 studies adopted behavior change theory. The most frequently cited theory was the health belief model, which was adopted in three studies. Likewise, studies have applied only a limited number of BCTs. Among the seven BCTs identified, the most frequently used one was the social support (practical) technique for medication reminder and medical appointment. m-Health studies in LMICs most commonly used short messaging services and phone calls as modes of delivery for behavior change interventions. m-Health studies in LMICs are suboptimally based on behavior change theory yet. To maximize effectiveness of m-Health, rigorous delivery methods as well as theory-based intervention designs will be needed.

  10. The theory of planned behaviour and discrete food choices: a systematic review and meta-analysis.

    McDermott, Máirtín S; Oliver, Madalyn; Svenson, Alexander; Simnadis, Thomas; Beck, Eleanor J; Coltman, Tim; Iverson, Don; Caputi, Peter; Sharma, Rajeev

    2015-12-30

    The combination of economic and social costs associated with non-communicable diseases provide a compelling argument for developing strategies that can influence modifiable risk factors, such as discrete food choices. Models of behaviour, such as the Theory of Planned Behaviour (TPB) provide conceptual order that allows program designers and policy makers to identify the substantive elements that drive behaviour and design effective interventions. The primary aim of the current review was to examine the association between TPB variables and discrete food choice behaviours. A systematic literature search was conducted to identify relevant studies. Calculation of the pooled mean effect size (r(+)) was conducted using inverse-variance weighted, random effects meta-analysis. Heterogeneity across studies was assessed using the Q- and I(2)-statistics. Meta-regression was used to test the impact of moderator variables: type of food choice behaviour; participants' age and gender. A total of 42 journal articles and four unpublished dissertations met the inclusion criteria. TPB variables were found to have medium to large associations with both intention and behaviour. Attitudes had the strongest association with intention (r(+)  = 0.54) followed by perceived behavioural control (PBC, r(+)  = 0.42) and subjective norm (SN, r(+)  = 0.37). The association between intention and behaviour was r(+)  = 0.45 and between PBC and behaviour was r(+)  = 0.27. Moderator analyses revealed the complex nature of dietary behaviour and the factors that underpin individual food choices. Significantly higher PBC-behaviour associations were found for choosing health compromising compared to health promoting foods. Significantly higher intention-behaviour and PBC-behaviour associations were found for choosing health promoting foods compared to avoiding health compromising foods. Participant characteristics were also found to moderate associations within the model. Higher

  11. The use of behavior change theory in Internet-based asthma self-management interventions: a systematic review.

    Al-Durra, Mustafa; Torio, Monika-Bianca; Cafazzo, Joseph A

    2015-04-02

    The high prevalence rate of asthma represents a major societal burden. Advancements in information technology continue to affect the delivery of patient care in all areas of medicine. Internet-based solutions, social media, and mobile technology could address some of the problems associated with increasing asthma prevalence. This review evaluates Internet-based asthma interventions that were published between 2004 and October 2014 with respect to the use of behavioral change theoretical frameworks, applied clinical guidelines, and assessment tools. The search term (Asthma AND [Online or Internet or Mobile or Application or eHealth or App]) was applied to six bibliographic databases (Ovid MEDLINE, PubMed, BioMed Central, ProQuest Computing, Web of Knowledge, and ACM Digital Library) including only English-language articles published between 2004 and October 2014. In total, 3932 articles matched the priori search terms and were reviewed by the primary reviewer based on their titles, index terms, and abstracts. The matching articles were then screened by the primary reviewer for inclusion or exclusion based on their abstract, study type, and intervention objectives with respect to the full set of priori inclusion and exclusion criteria; 331 duplicates were identified and removed. A total of 85 articles were included for in-depth review and the remaining 3516 articles were excluded. The primary and secondary reviewer independently reviewed the complete content of the 85 included articles to identify the applied behavioral change theories, clinical guidelines, and assessment tools. Findings and any disagreement between reviewers were resolved by in-depth discussion and through a consolidation process for each of the included articles. The reviewers identified 17 out of 85 interventions (20%) where at least one model, framework, and/or construct of a behavioral change theory were applied. The review identified six clinical guidelines that were applied across 30 of the 85

  12. Global Λ hyperon polarization in nuclear collisions

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; de La Barca Sánchez, M. Calderón; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; de Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, B.; Huang, X.; Huang, H. Z.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, W.; Li, Y.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, H.; Liu, P.; Liu, Y.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, Y. G.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.

    2017-08-01

    The extreme energy densities generated by ultra-relativistic collisions between heavy atomic nuclei produce a state of matter that behaves surprisingly like a fluid, with exceptionally high temperature and low viscosity. Non-central collisions have angular momenta of the order of 1,000ћ, and the resulting fluid may have a strong vortical structure that must be understood to describe the fluid properly. The vortical structure is also of particular interest because the restoration of fundamental symmetries of quantum chromodynamics is expected to produce novel physical effects in the presence of strong vorticity. However, no experimental indications of fluid vorticity in heavy ion collisions have yet been found. Since vorticity represents a local rotational structure of the fluid, spin-orbit coupling can lead to preferential orientation of particle spins along the direction of rotation. Here we present measurements of an alignment between the global angular momentum of a non-central collision and the spin of emitted particles (in this case the collision occurs between gold nuclei and produces Λ baryons), revealing that the fluid produced in heavy ion collisions is the most vortical system so far observed. (At high energies, this fluid is a quark-gluon plasma.) We find that Λ and hyperons show a positive polarization of the order of a few per cent, consistent with some hydrodynamic predictions. (A hyperon is a particle composed of three quarks, at least one of which is a strange quark; the remainder are up and down quarks, found in protons and neutrons.) A previous measurement that reported a null result, that is, zero polarization, at higher collision energies is seen to be consistent with the trend of our observations, though with larger statistical uncertainties. These data provide experimental access to the vortical structure of the nearly ideal liquid created in a heavy ion collision and should prove valuable in the development of hydrodynamic models that

  13. On the quantum Landau collision operator and electron collisions in dense plasmas

    Daligault, Jérôme, E-mail: daligaul@lanl.gov [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2016-03-15

    The quantum Landau collision operator, which extends the widely used Landau/Fokker-Planck collision operator to include quantum statistical effects, is discussed. The quantum extension can serve as a reference model for including electron collisions in non-equilibrium dense plasmas, in which the quantum nature of electrons cannot be neglected. In this paper, the properties of the Landau collision operator that have been useful in traditional plasma kinetic theory and plasma transport theory are extended to the quantum case. We outline basic properties in connection with the conservation laws, the H-theorem, and the global and local equilibrium distributions. We discuss the Fokker-Planck form of the operator in terms of three potentials that extend the usual two Rosenbluth potentials. We establish practical closed-form expressions for these potentials under local thermal equilibrium conditions in terms of Fermi-Dirac and Bose-Einstein integrals. We study the properties of linearized quantum Landau operator, and extend two popular approximations used in plasma physics to include collisions in kinetic simulations. We apply the quantum Landau operator to the classic test-particle problem to illustrate the physical effects embodied in the quantum extension. We present useful closed-form expressions for the electron-ion momentum and energy transfer rates. Throughout the paper, similarities and differences between the quantum and classical Landau collision operators are emphasized.

  14. On the quantum Landau collision operator and electron collisions in dense plasmas

    Daligault, Jérôme

    2016-03-01

    The quantum Landau collision operator, which extends the widely used Landau/Fokker-Planck collision operator to include quantum statistical effects, is discussed. The quantum extension can serve as a reference model for including electron collisions in non-equilibrium dense plasmas, in which the quantum nature of electrons cannot be neglected. In this paper, the properties of the Landau collision operator that have been useful in traditional plasma kinetic theory and plasma transport theory are extended to the quantum case. We outline basic properties in connection with the conservation laws, the H-theorem, and the global and local equilibrium distributions. We discuss the Fokker-Planck form of the operator in terms of three potentials that extend the usual two Rosenbluth potentials. We establish practical closed-form expressions for these potentials under local thermal equilibrium conditions in terms of Fermi-Dirac and Bose-Einstein integrals. We study the properties of linearized quantum Landau operator, and extend two popular approximations used in plasma physics to include collisions in kinetic simulations. We apply the quantum Landau operator to the classic test-particle problem to illustrate the physical effects embodied in the quantum extension. We present useful closed-form expressions for the electron-ion momentum and energy transfer rates. Throughout the paper, similarities and differences between the quantum and classical Landau collision operators are emphasized.

  15. Gamma-rays from deep inelastic collisions

    Stephens, F.S.

    1979-01-01

    The γ-rays associated with deep inelastic collisions can give information about the magnitude and orientation of the angular momentum transferred in these events. In this review, special emphasis is placed on understanding the origin and nature of these γ-rays in order to avoid some of the ambiguities that can arise. The experimental information coming from these γ-ray studies is reviewed, and compared briefly with that obtained by other methods and also with the expectations from current models for deep inelastic collisions. 15 figures

  16. String theory or field theory?

    Marshakov, A.V.

    2002-01-01

    The status of string theory is reviewed, and major recent developments - especially those in going beyond perturbation theory in the string theory and quantum field theory frameworks - are analyzed. This analysis helps better understand the role and place of experimental phenomena, it is emphasized that there are some insurmountable problems inherent in it - notably the impossibility to formulate the quantum theory of gravity on its basis - which prevent it from being a fundamental physical theory of the world of microscopic distances. It is this task, the creation of such a theory, which string theory, currently far from completion, is expected to solve. In spite of its somewhat vague current form, string theory has already led to a number of serious results and greatly contributed to progress in the understanding of quantum field theory. It is these developments, which are our concern in this review [ru

  17. Theory of reasoned action and theory of planned behavior-based dietary interventions in adolescents and young adults: a systematic review

    Hackman CL

    2014-06-01

    Full Text Available Christine L Hackman, Adam P KnowldenDepartment of Health Science, The University of Alabama, Tuscaloosa, AL, USABackground: Childhood obesity has reached epidemic proportions in many nations around the world. The theory of planned behavior (TPB and the theory of reasoned action (TRA have been used to successfully plan and evaluate numerous interventions for many different behaviors. The aim of this study was to systematically review and synthesize TPB and TRA-based dietary behavior interventions targeting adolescents and young adults.Methods: The following databases were systematically searched to find articles for this review: Academic Search Premier; Cumulative Index to Nursing and Allied Health (CINAHL; Education Resources Information Center (ERIC; Health Source: Nursing/Academic Edition; Cochrane Central Register of Controlled Trials (CENTRAL; and MEDLINE. Inclusion criteria for articles were: 1 primary or secondary interventions, 2 with any quantitative design, 3 published in the English language, 4 between January 2003 and March 2014, 5 that targeted adolescents or young adults, 6 which included dietary change behavior as the outcome, and 7 utilized TPB or TRA.Results: Of the eleven intervention studies evaluated, nine resulted in dietary behavior change that was attributed to the treatment. Additionally, all but one study found there to be a change in at least one construct of TRA or TPB, while one study did not measure constructs. All of the studies utilized some type of quantitative design, with two employing quasi-experimental, and eight employing randomized control trial design. Among the studies, four utilized technology including emails, social media posts, information on school websites, web-based activities, audio messages in classrooms, interactive DVDs, and health-related websites. Two studies incorporated goal setting and four employed persuasive communication.Conclusion: Interventions directed toward changing dietary behaviors

  18. Theory of reasoned action and theory of planned behavior-based dietary interventions in adolescents and young adults: a systematic review.

    Hackman, Christine L; Knowlden, Adam P

    2014-01-01

    Childhood obesity has reached epidemic proportions in many nations around the world. The theory of planned behavior (TPB) and the theory of reasoned action (TRA) have been used to successfully plan and evaluate numerous interventions for many different behaviors. The aim of this study was to systematically review and synthesize TPB and TRA-based dietary behavior interventions targeting adolescents and young adults. THE FOLLOWING DATABASES WERE SYSTEMATICALLY SEARCHED TO FIND ARTICLES FOR THIS REVIEW: Academic Search Premier; Cumulative Index to Nursing and Allied Health (CINAHL); Education Resources Information Center (ERIC); Health Source: Nursing/Academic Edition; Cochrane Central Register of Controlled Trials (CENTRAL); and MEDLINE. Inclusion criteria for articles were: 1) primary or secondary interventions, 2) with any quantitative design, 3) published in the English language, 4) between January 2003 and March 2014, 5) that targeted adolescents or young adults, 6) which included dietary change behavior as the outcome, and 7) utilized TPB or TRA. Of the eleven intervention studies evaluated, nine resulted in dietary behavior change that was attributed to the treatment. Additionally, all but one study found there to be a change in at least one construct of TRA or TPB, while one study did not measure constructs. All of the studies utilized some type of quantitative design, with two employing quasi-experimental, and eight employing randomized control trial design. Among the studies, four utilized technology including emails, social media posts, information on school websites, web-based activities, audio messages in classrooms, interactive DVDs, and health-related websites. Two studies incorporated goal setting and four employed persuasive communication. Interventions directed toward changing dietary behaviors in adolescents should aim to incorporate multi-faceted, theory-based approaches. Future studies should consider utilizing randomized control trial design and

  19. Quarkonia at finite temperature in relativistic heavy-ion collisions

    Datta, Saumen

    2015-01-01

    The behaviour of quarkonia in relativistic heavy-ion collisions is reviewed. After a detailed discussion of the current theoretical understanding of quarkonia in a static equilibriated plasma, we discuss quarkonia yield from the fireball created in ultrarelativistic heavy-ion collision experiments. We end with a brief discussion of the experimental results and outlook. (author)

  20. Quarkonia at finite temperature in relativistic heavy-ion collisions

    2015-05-06

    May 6, 2015 ... The behaviour of quarkonia in relativistic heavy-ion collisions is reviewed. After a detailed discussion of the current theoretical understanding of quarkonia in a static equilibriated plasma, we discuss quarkonia yield from the fireball created in ultrarelativistic heavy-ion collision experiments. We end with a ...

  1. On-the-Job Training and Social Learning Theory. A Literature Review

    1980-05-01

    and discussed by Albert Bandura (47). The principles of social learning theory and learning from models are first described. Then a series of rules...developed by Bandura and his students (47, 48, 49) to be the most useful theory to account for observational learning and to provide a basis for...Learning Theory and Its Application 47. Bandura , A. Principles of Behavior Modification, New York: Holt, Rinehart & Winston, 1969. 48. Bandura , A

  2. Thirty Years of Prospect Theory in Economics: A Review and Assessment

    Nicholas C. Barberis

    2013-01-01

    In 1979, Daniel Kahneman and Amos Tversky, published a paper in Econometrica titled "Prospect Theory: An Analysis of Decision under Risk." The paper presented a new model of risk attitudes called "prospect theory," which elegantly captured the experimental evidence on risk taking, including the documented violations of expected utility. More than 30 years later, prospect theory is still widely viewed as the best available description of how people evaluate risk in experimental settings. Howev...

  3. Plasmas applied atomic collision physics, v.2

    Barnett, C F

    1984-01-01

    Applied Atomic Collision Physics, Volume 2: Plasmas covers topics on magnetically confined plasmas. The book starts by providing the history of fusion research and describing the various approaches in both magnetically and inertially confined plasmas. The text then gives a general discussion of the basic concepts and properties in confinement and heating of a plasma. The theory of atomic collisions that result in excited quantum states, particularly highly ionized impurity atoms; and diverse diagnostic topics such as emission spectra, laser scattering, electron cyclotron emission, particle bea

  4. Fokker-Planck theory of electron cyclotron assisted startup and breakdown in Tokamaks

    Fidone, I.; Granata, G.

    1993-04-01

    The kinetic theory of plasma startup in a tokamak in the presence of electron cyclotron resonance heating is discussed. The linear theory of the X-mode and the upper-hybrid converted mode damping in low density and temperature plasmas are first reviewed. Then, the kinetic equation for the electron velocity distribution is considered, which is determined by the perpendicular electron cyclotron quasilinear diffusion operator, the parallel electric field, elastic and inelastic electron-neutral collisions and various losses. Two different time scales, namely the elastic electron-neutral collision time and the much longer ionization time, are identified. Thus a two time scale ordering procedure is legitimated for which the velocity distribution is determined by the quasilinear diffusion and the electron-neutral collision frequency; the ionization rate is computed using the Fokker-Planck solution for the electron velocity distribution

  5. Probing vacuum structure in nuclear collisions. Research report period: 1992--1995

    Rafelski, J.

    1995-02-01

    This is a report of the research activities in the field of Relativistic Nuclear Collisions/Theoretical Nuclear Physics of Johann Refelski at University of Arizona, supported by the Department of Energy, Nuclear Physics Division under grant No. DE-FG02-92ER40733. This report comprises: Section 1 surveys the general context of the work and presents summary of wider research objectives; Section 2 reviews the progress in the interpretation of experimental data, primarily related to diagnosis of high density nuclear matter with strange particle production, in heavy ion collisions at 10--200 GeV A; Section 3 presents the status of the studies of a relativistic quantum transport theory and the related vacuum structure and particle production processes; Section 4 presents a compilation of research projects completed under auspices of this program, with a short narrative description of publication contents

  6. Quantum theory of scattering

    Wu Ta You

    1962-01-01

    This volume addresses the broad formal aspects and applications of the quantum theory of scattering in atomic and nuclear collisions. An encyclopedic source of pioneering work, it serves as a text for students and a reference for professionals in the fields of chemistry, physics, and astrophysics. The self-contained treatment begins with the general theory of scattering of a particle by a central field. Subsequent chapters explore particle scattering by a non-central field, collisions between composite particles, the time-dependent theory of scattering, and nuclear reactions. An examinati

  7. Nuclear theory progress report

    1991-01-01

    This report discusses research performed at University of Washington in nuclear theory. Some of the topics discussed are: nuclear astrophysics; symmetry; time reversal invariance; quark matter; superallowed beta decay; exclusive reactions; nuclear probes; soliton model; relativistic heavy ion collisions; supernova explosions; neutrino processes in dense matter; field theories; weak interaction physics; and nuclear structure

  8. Immersion Revisited: A Review of Existing Definitions of Immersion and Their Relation to Different Theories of Presence

    Niels Christian Nilsson

    2016-11-01

    Full Text Available The term immersion continues to be applied inconsistently within and across different fields of research connected with the study of virtual reality and interactive media. Moreover, immersion is oftentimes used interchangeably with the terms presence and engagement. This article details a review of existing definitions of immersion originating within the study of video games, virtual environments, and literary works of fiction. Based on this review, a three-dimensional taxonomy of the various conceptualizations of immersion is proposed. That is, the existing definitions of immersion may be broadly divided into three categories, each representing a dimension of the taxonomy: immersion as a property of a system, a subjective response to narrative contents, or a subjective response to challenges within the virtual environment. Finally, four distinct theories of presence are introduced and, based on the established taxonomy, we discuss how the individual theories relate to existing definitions of immersion.

  9. Towards relativistic heavy ion collisions 'by small steps towards the stars'

    Scott, D.K.

    1980-01-01

    Current attempts to search for the exotic processes occurring in relativistic heavy ion collisions are reviewed under the headings; peripheral collisions (peripheral collisions as a function of energy, new features at intermediate energies, ground state correlations, microscopic aspects), central collisions (low energy perspective, time scales in heavy ion collisions, spatial, temporal localization and the onset of the nuclear fireball, models of particle emission in central relativistic collisions, the heart of the matter, multiplicity selection, the emission of composite particles), a search for the exotic (the limits of temperature and pressure, temporal and spatial limits, the limits of nuclear matter and nuclei,). 229 references. (U.K.)

  10. The relationship between vacuum and atomic collisions in solids

    Carter, G.; Armour, D.G.

    1980-01-01

    Atomic collision events in solids are frequently stimulated by external irradiation with energetic heavy ions. This requires production, acceleration and manipulation of ion beams in vacuum system with ensuing problems arising in perturbations to ion beam quality from gas phase collisions. In addition the dynamic interaction between the gas phase and any surfaces at which atomic collisions are under investigation can lead to perturbation to the collision events by adsorbed contaminant. This review discusses both gas phase requirements for ion accelerators to minimize deleterious effects and outlines some of the processes which occur in atomic collisions due to the presence of adsorbed impurities. Finally it is shown how certain atomic collision processes involving elastic scattering may be employed to investigate surface adsorption and related effects. (author)

  11. The Influence of Emotion on Fairness-Related Decision Making: A Critical Review of Theories and Evidence

    Ya Zheng; Zhong Yang; Zhong Yang; Chunlan Jin; Yue Qi; Yue Qi; Xun Liu; Xun Liu

    2017-01-01

    Fairness-related decision making is an important issue in the field of decision making. Traditional theories emphasize the roles of inequity aversion and reciprocity, whereas recent research increasingly shows that emotion plays a critical role in this type of decision making. In this review, we summarize the influences of three types of emotions (i.e., the integral emotion experienced at the time of decision making, the incidental emotion aroused by a task-unrelated dispositional or situatio...

  12. Electron-molecule collisions

    Shimamura, I.; Takayanagi, K.

    1984-01-01

    The study of collision processes plays an important research role in modern physics. Many significant discoveries have been made by means of collision experiments. Based on theoretical, experimental, and computational studies, this volume presents an overview detailing the basic processes of electron-molecule collisions. The editors have collected papers-written by a group of international experts-that consider a diverse range of phenomena occurring in electronmolecule collisions. The volume discusses first the basic formulation for scattering problems and then gives an outline of the physics of electron-molecule collisions. The main topics covered are rotational transitions, vibrational transitions, dissociation of molecules in slow collisions, the electron-molecule collision as a spectroscopic tool for studying molecular electronic structures, and experimental and computational techniques for determining the cross sections. These well-referenced chapters are self-contained and can be read independently or consecutively. Authoritative and up-to-date, Electron-Molecule Collisions is a useful addition to the libraries of students and researchers in the fields of atomic, molecular, and chemical physics, and physical chemistry

  13. A Review of Three Major Sociological Theories and an Islamic Perspective

    HAYATULLAH LALUDDIN

    2016-12-01

    Full Text Available This article examines critically the three major sociological theories namely, Structural Functionalism, Symbolic Interactionism and Conflict theory. These theories are formulated on the pattern of science where scientific method is strictly adhered to. Considering the nature and the essence of the social phenomenon and its component parts the author argues that the application of pure scientific method in the study or analysis of the social phenomenon fail to present an accurate understanding of the social phenomenon. Thus, an alternative method which is capable of taking into consideration both physical and metaphysical aspects of the social phenomenon is required. Toward this end this article attempts to delineate the three major theories of sociology, their shortcoming and loophole, then attempt to highlight the constituent elements of the social phenomenon and their significance in formulation of comprehensive sociological theories. An Islamic perspective on sociological theories is also provided in the last part of this article where the discrepancy of the sociological theories are disclosed and a proposal for a more dynamic method for the formulation of sociological theories of comprehensive nature is made.

  14. Overview of electromagnetic probe production in ultra-relativistic heavy ion collisions

    Paquet, Jean-François

    2017-01-01

    An introductory overview of electromagnetic probe production in ultra-relativistic heavy ion collisions is provided. Experimental evidence supporting the production of thermal photons and dileptons in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) are reviewed. Thermal electromagnetic probe production from hydrodynamical models of collisions is discussed. (paper)

  15. Atomic and molecular theory

    Inokuti, Mitio.

    1990-01-01

    The multifaceted role of theoretical physics in understanding the earliest stages of radiation action is discussed. Scientific topics chosen for the present discourse include photoabsorption, electron collisions, and ionic collisions, and electron transport theory, Connections of atomic and molecular physics with condensed-matter physics are also discussed. The present article includes some historical perspective and an outlook for the future. 114 refs., 3 figs

  16. Atomic and molecular theory

    Inokuti, Mitio.

    1990-01-01

    The multifaceted role of theoretical physics in understanding the earliest stages of radiation action is discussed. Scientific topics chosen for the present discourse include photoabsorption, electron collisions, and ionic collisions, and electron transport theory, Connections of atomic and molecular physics with condensed-matter physics are also discussed. The present article includes some historical perspective and an outlook for the future. 114 refs., 3 figs.

  17. Using resource dependency theory to measure the environment in health care organizational studies: a systematic review of the literature.

    Yeager, Valerie A; Menachemi, Nir; Savage, Grant T; Ginter, Peter M; Sen, Bisakha P; Beitsch, Leslie M

    2014-01-01

    Studies using the resource dependency theory (RDT) perspective commonly focus on one or more of the following environmental dimensions: munificence, dynamism, and complexity. To date, no one has reviewed the use of this theory in the health care management literature and there exists no consensus on how to operationalize the market environment in health care settings. The purpose of this review is to examine and summarize the ways in which RDT has been applied in empirical studies of the external environments of health care organizations. In so doing, we identify gaps in the literature and examine the extent to which previous empirical findings aligned with hypothesized relationships based on RDT. We conducted a systematic review of the peer-reviewed literature using a bibliographic search of PubMed and ABI/Inform databases. To identify all health care studies that incorporated the RDT perspective, the words "healthcare" or "health care" were searched in combination with any of the following words: resource dependency theory, uncertainty perspective, environment, munificence, dynamism, and complexity. We also performed a hand search of the reference lists of all manuscripts identified in the initial search to identify additional articles. Twenty studies were included in this review. Wide variability existed in the number of variables used to measure the environment, the environmental constructs measured, and the specific variables used to operationalizethe environmental constructs. Of the 198 tests examining the relationship between environmental variables and the outcome of interest, 26.8% resulted in findings that supported the RDT-predicted hypotheses. The RDT literature is limited to studies of hospitals, nursing homes, and medical practices. There is little consensus on how to measure or operationalize the environment in these studies. No previous studies have measured the environment for other health care settings such as ambulatory surgery centers, public

  18. Promoting professional behaviour change in healthcare: what interventions work, and why? A theory-led overview of systematic reviews.

    Johnson, Mark J; May, Carl R

    2015-09-30

    Translating research evidence into routine clinical practice is notoriously difficult. Behavioural interventions are often used to change practice, although their success is variable and the characteristics of more successful interventions are unclear. We aimed to establish the characteristics of successful behaviour change interventions in healthcare. We carried out a systematic overview of systematic reviews on the effectiveness of behaviour change interventions with a theory-led analysis using the constructs of normalisation process theory (NPT). MEDLINE, CINAHL, PsychINFO and the Cochrane Library were searched electronically from inception to July 2015. Primary and secondary care. Participants were any patients and healthcare professionals in systematic reviews who met the inclusion criteria of having examined the effectiveness of professional interventions in improving professional practice and/or patient outcomes. Professional interventions as defined by the Cochrane Effective Practice and Organisation of Care Review Group. Success of each intervention in changing practice or patient outcomes, and their mechanisms of action. Reviews were coded as to the interventions included, how successful they had been and which NPT constructs its component interventions covered. Searches identified 4724 articles, 67 of which met the inclusion criteria. Interventions fell into three main categories: persuasive; educational and informational; and action and monitoring. Interventions focusing on action or education (eg, Audit and Feedback, Reminders, Educational Outreach) acted on the NPT constructs of Collective Action and Reflexive Monitoring, and reviews using them tended to report more positive outcomes. This theory-led analysis suggests that interventions which contribute to normative restructuring of practice, modifying peer group norms and expectations (eg, educational outreach) and relational restructuring, reinforcing modified peer group norms by emphasising the

  19. An accurate nonlinear Monte Carlo collision operator

    Wang, W.X.; Okamoto, M.; Nakajima, N.; Murakami, S.

    1995-03-01

    A three dimensional nonlinear Monte Carlo collision model is developed based on Coulomb binary collisions with the emphasis both on the accuracy and implementation efficiency. The operator of simple form fulfills particle number, momentum and energy conservation laws, and is equivalent to exact Fokker-Planck operator by correctly reproducing the friction coefficient and diffusion tensor, in addition, can effectively assure small-angle collisions with a binary scattering angle distributed in a limited range near zero. Two highly vectorizable algorithms are designed for its fast implementation. Various test simulations regarding relaxation processes, electrical conductivity, etc. are carried out in velocity space. The test results, which is in good agreement with theory, and timing results on vector computers show that it is practically applicable. The operator may be used for accurately simulating collisional transport problems in magnetized and unmagnetized plasmas. (author)

  20. Shared decision-making behaviours in health professionals: a systematic review of studies based on the Theory of Planned Behaviour.

    Thompson-Leduc, Philippe; Clayman, Marla L; Turcotte, Stéphane; Légaré, France

    2015-10-01

    Shared decision making (SDM) requires health professionals to change their practice. Socio-cognitive theories, such as the Theory of Planned Behaviour (TPB), provide the needed theoretical underpinnings for designing behaviour change interventions. We systematically reviewed studies that used the TPB to assess SDM behaviours in health professionals to explore how theory is being used to explain influences on SDM intentions and/or behaviours, and which construct is identified as most influential. We searched PsycINFO, MEDLINE, EMBASE, CINAHL, Index to theses, Proquest dissertations and Current Contents for all years up to April 2012. We included all studies in French or English that used the TPB and related socio-cognitive theories to assess SDM behavioural intentions or behaviours in health professionals. We used Makoul & Clayman's integrative SDM model to identify SDM behaviours. We extracted study characteristics, nature of the socio-cognitive theory, SDM behaviour, and theory-based determinants of the SDM behavioural intention or behaviour. We computed simple frequency counts. Of 12,388 titles, we assessed 136 full-text articles for eligibility. We kept 20 eligible studies, all published in English between 1996 and 2012. Studies were conducted in Canada (n = 8), the USA (n = 6), the Netherlands (n = 3), the United Kingdom (n = 2) and Australia (n = 1). The determinant most frequently and significantly associated with intention was the subjective norm (n = 15/21 analyses). There was great variance in the way socio-cognitive theories predicted SDM intention and/or behaviour, but frequency of significance indicated that subjective norm was most influential. © 2014 The Authors Health Expectations Published by John Wiley & Sons Ltd.