WorldWideScience

Sample records for electromagnetic interactions generalized

  1. Interacting electromagnetic waves in general relativity

    International Nuclear Information System (INIS)

    Griffiths, J.B.

    1976-01-01

    The problem is considered of finding exact solutions of the Einstein-Maxwell equations which describe the physical situation of two colliding and subsequently interacting electromagnetic waves. The general theory of relativity predicts a nonlinear interaction between electromagnetic waves. The situation is described using an approximate geometrical method, and a new exact solution describing two interacting electromagnetic waves is given. This describes waves emitted from two sources mutually focusing each other on the opposite source. (author)

  2. EIGER: Electromagnetic Interactions GEneRalized

    International Nuclear Information System (INIS)

    Champagne, N J; Sharpe, R M; Rockway, J W

    2001-01-01

    The EIGER (Electromagnetic Interactions Generalized) modeling suite is a joint development activity by the Lawrence Livermore National Lab, Sandia National Labs, the University of Houston, and the Navy (Space and Naval Warfare Systems Center-San Diego). The effort endeavors to bring the next generation of hybrid, higher-order, full-wave analysis methods into a single integrated framework. The tools are based upon frequency-domain solutions of Maxwell's equations to model scattering and radiation from complex 2D and 3D structures. The framework employs boundary element solutions of integral equation formulations and finite element solutions of the Helmholtz wave equation. A goal is to use higher-order representations to model both the geometry (using higher-order geometric elements) and numerical methods (using higher-order vector basis functions). In addition, a variety of advanced Green's functions and symmetry operators can be applied to efficiently treat geometries containing such features as layered material regions and periodic structures. Each of these methods can be brought to bear simultaneously, on different portions of a complex structure. HPC implementation issues were addressed during the design of the software architecture, so that the same package runs on platforms ranging from serial desktop workstations through advanced HPC architectures. Our current efforts on higher-order modeling and improved solver libraries will be highlighted

  3. Electromagnetic interactions

    International Nuclear Information System (INIS)

    Bosanac, Slobodan Danko

    2016-01-01

    This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.

  4. Electromagnetic cellular interactions.

    Science.gov (United States)

    Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan

    2011-05-01

    Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Intermediate energy electromagnetic interactions

    International Nuclear Information System (INIS)

    Garcon, M.

    1994-11-01

    Polarization measurements in electromagnetic interactions are reviewed. Deep inelastic scattering of polarized electrons and muons an polarized targets, photoproduction of pseudoscalar mesons on protons, photonuclear reactions, and the electromagnetic structure of the deuteron are discussed. (K.A.)

  6. Intermediate energy electromagnetic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Garcon, M.

    1994-11-01

    Polarization measurements in electromagnetic interactions are reviewed. Deep inelastic scattering of polarized electrons and muons an polarized targets, photoproduction of pseudoscalar mesons on protons, photonuclear reactions, and the electromagnetic structure of the deuteron are discussed. (K.A.).

  7. General Geometry and Geometry of Electromagnetism

    OpenAIRE

    Shahverdiyev, Shervgi S.

    2002-01-01

    It is shown that Electromagnetism creates geometry different from Riemannian geometry. General geometry including Riemannian geometry as a special case is constructed. It is proven that the most simplest special case of General Geometry is geometry underlying Electromagnetism. Action for electromagnetic field and Maxwell equations are derived from curvature function of geometry underlying Electromagnetism. And it is shown that equation of motion for a particle interacting with electromagnetic...

  8. Electromagnetic processes and interactions

    International Nuclear Information System (INIS)

    Scheck, F.

    1983-01-01

    The electron and muon are important tools in testing the structure of the fundamental electromagnetic interactions. On the other hand, if these interactions are known, they serve as ideal probes for the internal structure of complex hadronic targets such as nucleons and nuclei. Purely electromagnetic interactions play a distinctive role, for obvious experimental reasons: At low and intermediate energies the effective electromagnetic coupling is larger by many orders of magnitude than the weak couplings, so that electromagnetic processes are measurable to much higher accuracy than purely weak processes. The present chapter deals primarily with applications of charged leptons to problems of nucleon and nuclear structure, and to selected precision tests of quantum electrodynamics (QED) at low momentum transfers. In most of these applications the electromagnetic interactions effectively appear in the form of external fields in the leptonic particle's Dirac equation. This is the domain where the physics of (electromagnetically) interacting leptons can still be described in the framework of an effective, though relativistic, single particle theory. (orig.)

  9. Electromagnetic current in weak interactions

    International Nuclear Information System (INIS)

    Ma, E.

    1983-01-01

    In gauge models which unify weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current. The exact nature of such a component can be explored using e + e - experimental data. In recent years, the existence of a new component of the weak interaction has become firmly established, i.e., the neutral-current interaction. As such, it competes with the electromagnetic interaction whenever the particles involved are also charged, but at a very much lower rate because its effective strength is so small. Hence neutrino processes are best for the detection of the neutral-current interaction. However, in any gauge model which unifies weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current

  10. Causal electromagnetic interaction equations

    International Nuclear Information System (INIS)

    Zinoviev, Yury M.

    2011-01-01

    For the electromagnetic interaction of two particles the relativistic causal quantum mechanics equations are proposed. These equations are solved for the case when the second particle moves freely. The initial wave functions are supposed to be smooth and rapidly decreasing at the infinity. This condition is important for the convergence of the integrals similar to the integrals of quantum electrodynamics. We also consider the singular initial wave functions in the particular case when the second particle mass is equal to zero. The discrete energy spectrum of the first particle wave function is defined by the initial wave function of the free-moving second particle. Choosing the initial wave functions of the free-moving second particle it is possible to obtain a practically arbitrary discrete energy spectrum.

  11. Electromagnetic Interactions of Muons

    CERN Multimedia

    2002-01-01

    This experiment was the first in a programme of physics experiments with high-energy muons using a large spectrometer facility. The aim of this experiment is to study the inelastic scattering of muons with various targets to try to understand better the physics of virtual photon interactions over a wide range of four-momentum transfer (q$^{2}$).\\\\ \\\\ The spectrometer includes a large aperture dipole magnet (2m x 1m) of bending power $\\simeq$5 T.m and a magnetized iron filter to distinguish the scattered muons from hadrons. Drift chambers and MWPC are used before and after the magnet to detect charged products of the interaction and to allow a momentum determination of the scattered muon to an accuracy of $\\simeq$at 100 GeV/c, and an angular definition of $\\pm$ 0.1 mrad. The triggering on scattered muons relies on three planes of scintillation counter hodoscopes before and after the magnetized iron, whose magnetic field serves to eliminate triggers from low momentum muons which are produced copiously by pion d...

  12. Gauge theory of weak, electromagnetic and dual electromagnetic interactions

    International Nuclear Information System (INIS)

    Soln, J.

    1980-01-01

    An SU 2 x U 1 algebra, in addition to the ordinary electric charge, also establishes the existence of the dual electric charge. This is taken as an indication of the existence of dual electromagnetic interactions in nature. Here, the unification of weak, electromagnetic and dual electromagnetic interactions is performed. The Yang-Mills-type group which contains the electromagnetic, dual electromagnetic and weak currents is SUsub(L,2) x U 1 x U' 1 . The masses of vector mesons are generated through the Higgs-Kibble mechanism. A simple consistency requirement suggests that dual electromagnetism and ordinary electromagnetism have the same strengths, leading the theory to a rather good agreement with experiments. (author)

  13. Electromagnetic aquametry electromagnetic wave interaction with water and moist substances

    CERN Document Server

    Kupfer, Klaus

    2006-01-01

    This book covers all aspects of Electromagnetic Aquametry. It summarizes the wide area of metrology and its applications in electromagnetic sensing of moist materials. The physical properties of water in various degrees of binding interacting with electromagnetic fields is presented by model systems. The book describes measurement methods and sensors in the frequency domain, TDR-techniques for environmental problems, methods and sensors for quality assessment of biological substances, and nuclear magnetic resonance techniques. Environmental sciences, as well as civil and geoengineering, fossil fuels, food and pharmaceutical science are the main fields of application. A very wide frequency sprectrum is used for dielectric measurement methods, but the microwave range is clearly dominant. Multiparameter methods as well as methods of principal components and artificial neural networks for density independent measurements are described.

  14. Interactions between electromagnetic fields and matter

    CERN Document Server

    Steiner, Karl-Heinz

    2013-01-01

    Interactions between Electromagnetic Fields and Matter deals with the principles and methods that can amplify electromagnetic fields from very low levels of signals. This book discusses how electromagnetic fields can be produced, amplified, modulated, or rectified from very low levels to enable these for application in communication systems. This text also describes the properties of matter and some phenomenological considerations to the reactions of matter when an action of external fields results in a polarization of the particle system and changes the bonding forces existing in the matter.

  15. Unification of Electromagnetism and Gravitation in the Framework of General Geometry

    OpenAIRE

    Shahverdiyev, Shervgi

    2005-01-01

    A new geometry, called General geometry, is constructed. It is proven that its the most simplest special case is geometry underlying Electromagnetism. Another special case is Riemannian geometry. Action for electromagnetic field and Maxwell equations are derived from curvature function of geometry underlying Electromagnetism. It is shown that equation of motion for a particle interacting with electromagnetic field coincides exactly with equation for geodesics of geometry underlying Electromag...

  16. Theoretical status of weak and electromagnetic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Pandit, L. K.

    1980-07-01

    An extended simple version of the Weinberg gauge model is proposed to bring together weak and electromagnetic interactions under one theory. The essential features of the standard SU/sub 2/ (operating on)U/sub 1/ gauge scheme with four leptons and four quark flavours is recalled. Charged-current and neutral current interactions are described. Non-leptonic decays of strange particles are studied. The treatment is extended to 6-leptons and 6-quark flavours. The short comings of this model are discussed. Speculations on the unification of strong, weak and electromagnetic interactions are made.

  17. QUICKSILVER - A general tool for electromagnetic PIC simulation

    International Nuclear Information System (INIS)

    Seidel, David B.; Coats, Rebecca S.; Johnson, William A.; Kiefer, Mark L.; Mix, L. Paul; Pasik, Michael F.; Pointon, Timothy D.; Quintenz, Jeffrey P.; Riley, Douglas J.; Turner, C. David

    1997-01-01

    The dramatic increase in computational capability that has occurred over the last ten years has allowed fully electromagnetic simulations of large, complex, three-dimensional systems to move progressively from impractical, to expensive, and recently, to routine and widespread. This is particularly true for systems that require the motion of free charge to be self-consistently treated. The QUICKSILVER electromagnetic Particle-In-Cell (EM-PIC) code has been developed at Sandia National Laboratories to provide a general tool to simulate a wide variety of such systems. This tool has found widespread use for many diverse applications, including high-current electron and ion diodes, magnetically insulated power transmission systems, high-power microwave oscillators, high-frequency digital and analog integrated circuit packages, microwave integrated circuit components, antenna systems, radar cross-section applications, and electromagnetic interaction with biological material. This paper will give a brief overview of QUICKSILVER and provide some thoughts on its future development

  18. Non-linear electromagnetic interactions in thermal QED

    International Nuclear Information System (INIS)

    Brandt, F.T.; Frenkel, J.

    1994-08-01

    The behavior of the non-linear interactions between electromagnetic fields at high temperature is examined. It is shown that, in general, the log(T) dependence on the temperature of the Green functions is simply related to their UV behavior at zero-temperature. It is argued that the effective action describing the nonlinear thermal electromagnetic interactions has a finite limit as T -> ∞. This thermal action approaches, in the long wavelength limit, the negative of the corresponding zero-temperature action. (author). 12 refs, 1 fig

  19. Relativistic rapprochement of electromagnetic and strong interactions

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1995-01-01

    On the basis of the Lienard-Wiechert potential and the relativistic Yukawa potential it is shown that the corresponding interactions with velocity growth increase differently (the electromagnetic one increases faster). According to preliminary estimations they are equivalent, at distances of the 'action radius' of nuclear forces, at γ≅ 960, where γ is the Lorentz factor. 2 refs

  20. Electromagnetic interactions between antibiotics and bacteria

    Science.gov (United States)

    Abdul-Moqueet, Mohammad M.

    The effect of weak electromagnetic fields on the interaction of the antibiotic erythromycin on E.coli has been studied. Erythromycin is a first derivative antibiotic which is bacteriostatic in nature. E.coli's structure has been well studied and provides a baseline for understanding the interaction. Electromagnetic fields are shown to influence the growth curve of bacterium depending on the field's geometry. The theoretical model discussed in this thesis describes the interaction using a two-fluid model. The basis of this two-fluid model has been tested and shown that the concentration of antibiotics in the fluid environment is proportional to the response seen by the bacterium. The response of the bacterium has been determined using optical density measurements from which the behavior of the antibiotic-cell system has been studied.

  1. Principles of electromagnetic radiation interaction with matter

    Energy Technology Data Exchange (ETDEWEB)

    Ping, Tso Ching

    1981-01-01

    In the use of nuclear techniques, one of the safety problems is the protection of personnel and delicate instruments against harmful radiation. It is therefore of prime importance that the designer of nuclear experiments have a basic understanding of how radiation behaves when it passes through matter. This is a tutorial paper that presents the fundamentals of electromagnetic radiation with respect to its interaction and absorption in matter.

  2. Principles of electromagnetic radiation interaction with matter

    Energy Technology Data Exchange (ETDEWEB)

    Ping, T C

    1981-01-01

    In the use of nuclear techniques, one of safety problems is the protection of personnel and delicate instruments against harmful radiation. It is therefore of prime importance that the designer of nuclear experiments have a basic understanding of how radiation behaves when it passes through matter. This is a tutorial paper that presents the fundamentals of electromagnetic radiation with respect to its interaction and absorption in matter.

  3. Principles of electromagnetic radiation interaction with matter

    International Nuclear Information System (INIS)

    Tso Ching Ping

    1981-01-01

    In the use of nuclear techniques, one of the safety problems is the protection of personnel and delicate instruments against harmful radiation. It is therefore of prime importance that the designer of nuclear experiments have a basic understanding of how radiation behaves when it passes through matter. This is a tutorial paper that presents the fundamentals of electromagnetic radiation with respect to its interaction and absorption in matter. (author)

  4. Deep inelastic inclusive weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Adler, S.L.

    1976-01-01

    The theory of deep inelastic inclusive interactions is reviewed, emphasizing applications to electromagnetic and weak charged current processes. The following reactions are considered: e + N → e + X, ν + N → μ - + X, anti ν + N → μ + + X where X denotes a summation over all final state hadrons and the ν's are muon neutrinos. After a discussion of scaling, the quark-parton model is invoked to explain the principle experimental features of deep inelastic inclusive reactions

  5. Unification of electromagnetic, strong and weak interaction

    International Nuclear Information System (INIS)

    Duong Van Phi; Duong Anh Duc

    1993-09-01

    The Unification of Electromagnetic, Strong and Weak Interactions is realized in the framework of the Quantum Field Theory, established in an 8-dimensional Unified Space. Two fundamental, spinor and vector field equations are considered. The first of the matter particles and the second is of the gauge particles. Interaction Lagrangians are formed from the external and internal currents and the external and internal vector field operators. Generators of the local gauge transformations are the combinations of the matrices of the first field equation. (author). 15 refs

  6. On the electromagnetic interactions of anyons

    CERN Document Server

    Chou, Chi-hong; Polychronakos, Alexios P.

    1993-01-01

    Using the appropriate representation of the Poincare group and a definition of minimal coupling, we discuss some aspects of the electromagnetic interactions of charged anyons. In a nonrelativistic expansion, we derive a Schrodinger-type equation for the anyon wave function which includes spin-magnetic field and spin-orbit couplings. In particular, the gyromagnetic ratio for charged anyons is shown to be 2; this last result is essentially a reflection of the fact that the spin is parallel to the momentum in (2+1) dimensions.

  7. Strong and Electromagnetic Interactions at SPS Energies

    CERN Document Server

    Ribicki, Andrzej

    2009-01-01

    Particle production in peripheral Pb+Pb collisions has been measured at a beam energy of 158 GeV per nucleon, corresponding to psNN 17.3 GeV. The measurements provide full double differential coverage in a wide range of longitudinal and transverse momenta, including the central (“mid-rapidity”) area and extending far into the projectile fragmentation region. The resulting analysis shows the heavy ion reaction as a mixture of different processes. In particular, surprising phenomena, like the presence of large and strongly varying structures in the shape of the double differential cross section d2s /dxFd pT , are induced by the final state electromagnetic interaction between produced particles and the charged spectator system. This effect is largest at low transverse momenta, where it results in a deep valley in the xF -dependence of the produced p+/p− ratio. The basic characteristics of the electromagnetic phenomenon described above agree with the results of a theoretical analysis, performed by means of ...

  8. Electromagnetic interactions in the MINOS detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vahle, Patricia LaVern [Univ. of Texas, Austin, TX (United States)

    2004-08-01

    MINoS is a long-baseline neutrino experiment designed to observe the oscillation of neutrinos traveling between two detectors, a Near Detector at Fermi National Accelerator Laboratory and a Far Detector at the Soudan Underground Laboratory in northern Minnesota. Precision measurement of the oscillation parameters requires a better than 5% absolute energy calibration with is derived using a dedicated calibration detector, called CalDet. A smaller version of the MINOS detectors, the CalDet was exposed to particular beams in the CERN PS East Area test beams in 2001-2003. This document describes the conditions under which the CalDet beam data were taken, establishes selection criteria to identify a sample of electrons, and discusses the characteristics of electromagnetic interactions in the CalDet.

  9. Algebraic structure of general electromagnetic fields and energy flow

    International Nuclear Information System (INIS)

    Hacyan, Shahen

    2011-01-01

    Highlights: → Algebraic structure of general electromagnetic fields in stationary spacetime. → Eigenvalues and eigenvectors of the electomagnetic field tensor. → Energy-momentum in terms of eigenvectors and Killing vector. → Explicit form of reference frame with vanishing Poynting vector. → Application of formalism to Bessel beams. - Abstract: The algebraic structures of a general electromagnetic field and its energy-momentum tensor in a stationary space-time are analyzed. The explicit form of the reference frame in which the energy of the field appears at rest is obtained in terms of the eigenvectors of the electromagnetic tensor and the existing Killing vector. The case of a stationary electromagnetic field is also studied and a comparison is made with the standard short-wave approximation. The results can be applied to the general case of a structured light beams, in flat or curved spaces. Bessel beams are worked out as example.

  10. Electromagnetic interactions in relativistic infinite component wave equations

    International Nuclear Information System (INIS)

    Gerry, C.C.

    1979-01-01

    The electromagnetic interactions of a composite system described by relativistic infinite-component wave equations are considered. The noncompact group SO(4,2) is taken as the dynamical group of the systems, and its unitary irreducible representations, which are infinite dimensional, are used to find the energy spectra and to specify the states of the systems. First the interaction mechanism is examined in the nonrelativistic SO(4,2) formulation of the hydrogen atom as a heuristic guide. A way of making a minimal relativistic generalization of the minimal ineractions in the nonrelativistic equation for the hydrogen atom is proposed. In order to calculate the effects of the relativistic minimal interactions, a covariant perturbation theory suitable for infinite-component wave equations, which is an algebraic and relativistic version of the Rayleigh-Schroedinger perturbation theory, is developed. The electric and magnetic polarizabilities for the ground state of the hydrogen atom are calculated. The results have the correct nonrelativistic limits. Next, the relativistic cross section of photon absorption by the atom is evaluated. A relativistic expression for the cross section of light scattering corresponding to the seagull diagram is derived. The Born amplitude is combusted and the role of spacelike solutions is discussed. Finally, internal electromagnetic interactions that give rise to the fine structure splittings, the Lamb shifts and the hyperfine splittings are considered. The spin effects are introduced by extending the dynamical group

  11. Introduction to unification of electromagnetic and weak interactions

    International Nuclear Information System (INIS)

    Martin, F.

    1980-01-01

    After reviewing the present status of weak interaction phenomenology we discuss the basic principles of gauge theories. Then we show how Higgs mechanism can give massive quanta of interaction. The so-called 'Weinberg-Salam' model, which unifies electromagnetic and weak interactions, is described. We conclude with a few words on unification with strong interactions and gravity [fr

  12. Interaction of strong electromagnetic fields with atoms

    International Nuclear Information System (INIS)

    Brandi, H.S.; Davidovich, L.; Zagury, N.

    1982-06-01

    Several non-linear processes involvoing the interaction of atoms with strong laser fields are discussed, with particular emphasis on the ionization problem. Non-perturbative methods which have been proposed to tackle this problem are analysed, and shown to correspond to an expansion in the intra-atomic potential. The relation between tunneling and multiphoton absorption as ionization mechanisms, and the generalization of Einstein's photoelectric equation to the strong-field case are discussed. (Author) [pt

  13. Charged particle interaction with a chirped electromagnetic pulse

    NARCIS (Netherlands)

    Khachatryan, A.G.; Boller, Klaus J.; van Goor, F.A.

    2003-01-01

    It is found that a charged particle can get a net energy gain from the interaction with an electromagnetic chirped pulse. Theoretically, the energy gain increases with the pulse amplitude and with the relative frequency variation in the pulse.

  14. Interacting massless scalar and source-free electromagnetic fields

    International Nuclear Information System (INIS)

    Ayyangar, B.R.N.; Mohanty, G.

    1985-01-01

    The relativistic field equations for interacting massless attractive scalar and source-free electromagnetic fields in a cylindrically symmetric spacetime of one degree of freedom with reflection symmetry have been reduced to a first order implicit differential equation depending on time which enables one to generate a class of solution to the field equations. The nature of the scalar and electromagnetic fields is discussed. It is shown that the geometry of the spacetime admits of an irrotational stiff fluid distribution without prejudice to the interacting electromagnetic fields. 10 refs. (author)

  15. Some thermo-electromagnetic applications to fusion technology of a general purpose CAD package

    International Nuclear Information System (INIS)

    Girdinio, P.; Molfino, P.; Molinari, G.; Raia, G.; Rosatelli, F.; Viviani, A.

    1985-01-01

    A general purpose CAD package is applied to the solution of problems related to fusion technology. The problems solved are the interacting electromagnetic and thermal fields in a resistive toroidal coil and the design of the poloidal field coils in Tokamak machines. In both cases, the procedure used is reported and the results obtained are displayed and discussed

  16. Some thermo-electromagnetic applications to fusion technology of a general purpose CAD package

    International Nuclear Information System (INIS)

    Girdinio, P.; Molfino, P.; Molinari, G.; Viviani, A.; Raia, G.; Rosatelli, F.

    1984-01-01

    A general purpose CAD package is applied to the solution of problems related to fusion technology. The problems solved are the interacting electromagnetic and thermal fields in a resistive toroidal coil and the design of the poloidal field coils in Tokamak machines. In both cases, the procedure used is reported and the results obtained are displayed and discussed. (author)

  17. Transition operators in electromagnetic-wave diffraction theory - General theory

    Science.gov (United States)

    Hahne, G. E.

    1992-01-01

    A formal theory is developed for the scattering of time-harmonic electromagnetic waves from impenetrable immobile obstacles with given linear, homogeneous, and generally nonlocal boundary conditions of Leontovich (impedance) type for the wave of the obstacle's surface. The theory is modeled on the complete Green's function and the transition (T) operator in time-independent formal scattering theory of nonrelativistic quantum mechanics. An expression for the differential scattering cross section for plane electromagnetic waves is derived in terms of certain matrix elements of the T operator for the obstacle.

  18. Interaction between electromagnetic waves and plasma waves in motional plasma

    International Nuclear Information System (INIS)

    Chen, S. Y.; Gao, M.; Tang, C. J.; Peng, X. D.

    2009-01-01

    The electromagnetic wave (EM wave) behavior and the electromagnetic instability caused by the interaction between an EM wave and a plasma wave in motional plasma are studied. The dispersion relation of EM waves and the dielectric tensor of motional plasma are derived by magnetohydrodynamics, and the wave phenomenon in motional plasma is displayed. As a result, the electromagnetic instability, which is excited by the interaction between the EM waves and the plasma waves, is revealed. The mechanism of the instability is the coupling between high frequency electromagnetic field and the transverse electron oscillation derived from the deflection of longitudinal electron oscillation due to self-magnetic field. The present research is useful with regard to the new type of plasma radiation source, ion-focusing accelerator, and plasma diagnostic technique.

  19. Interaction of free charged particles with a chirped electromagnetic pulse

    NARCIS (Netherlands)

    Khachatryan, A.G.; van Goor, F.A.; Boller, Klaus J.

    2004-01-01

    We study the effect of chirp on electromagnetic (EM) pulse interaction with a charged particle. Both the one-dimensional (1D) and 3D cases are considered. It is found that, in contrast to the case of a nonchirped pulse, the charged particle energy can be changed after the interaction with a 1D EM

  20. Electromagnetic axial anomaly in a generalized linear sigma model

    Science.gov (United States)

    Fariborz, Amir H.; Jora, Renata

    2017-06-01

    We construct the electromagnetic anomaly effective term for a generalized linear sigma model with two chiral nonets, one with a quark-antiquark structure, the other one with a four-quark content. We compute in the leading order of this framework the decays into two photons of six pseudoscalars: π0(137 ), π0(1300 ), η (547 ), η (958 ), η (1295 ) and η (1760 ). Our results agree well with the available experimental data.

  1. Electromagnetic interactions in relativistic systems of many bodies

    International Nuclear Information System (INIS)

    Cook, A.H.

    1987-09-01

    In a previous report (Cook, 1986, 1987) on a formulation of a quasi-relativistic quantum mechanical equation of motion for many particles, little was said of the electromagnetic interactions that keep a set of particles in a bound state. That omission is to some extent repaired in this report. (author). 3 refs

  2. Multipole interactions of charged particles with the electromagnetic field

    International Nuclear Information System (INIS)

    Burzynski, A.

    1982-01-01

    The full multipole expansion for the lagrangian and hamiltonian of a system of point charges interacting with the electromagnetic field is studied in detail. Both classical and quantum theory are described for external and dynamical fields separately. One improvement with respect to the known Fiutak's paper is made. (author)

  3. Polarization phenomena in electromagnetic interactions at intermediate energies

    International Nuclear Information System (INIS)

    Burkert, V.

    1990-01-01

    Recent results of polarization measurements in electromagnetic interactions at intermediate energies are discussed. Prospects of polarization experiments at the new CW electron accelerators, as well as on upgraded older machines are outlined. It is concluded that polarization experiments will play a very important role in the study of the structure of the nucleon and of light nuclei. 72 refs

  4. Electromagnetic probes of strongly interacting matter

    Indian Academy of Sciences (India)

    2015-05-07

    May 7, 2015 ... Collisions between two nuclei at relativistic energies will create charged particles – either in .... The thermal cutting rules give a systematic procedure to express ...... mesons due to its interaction with the thermal partons [80] and employment of running .... [16] J Deng, Q Wang, N Xu and P Zhuang, Phys. Lett.

  5. Electromagnetic interactions with nuclei and nucleons

    International Nuclear Information System (INIS)

    Thornton, S.T.; Sealock, R.M.

    1990-01-01

    This report discusses the following topics: general LEGS work; photodisintegration of the deuteron; progress towards other experiments; LEGS instrumentation; major LEGS software projects; NaI detector system; nucleon detector system; waveshifting fibers; EGN prototype detector for CEBAF; photon beam facility at CEBAF; delta electroproduction in nuclei; quasielastic scattering and excitation of the Delta by 4 He(e,e'); and quasielastic scattering at high Q 2

  6. Supersymmetry and weak, electromagnetic and strong interactions

    International Nuclear Information System (INIS)

    Fayet, P.

    1977-01-01

    A supersymmetric theory of particle interactions is discussed. It is based on the earlier model which involves gauge (or vector) superfields, and matter (or chiral) superfields; each of them describes a vector and a Majorana spinor in the first case, or a two-component Dirac spinor and a complex scalar in the second case. The new theory suggests the possible existence of spin - 1/2 gluons and heavy spin-0 quarks, besides spin - 1 gluons and spin - 1/2 quarks. To prevent scalar particles to be exchanged in processes such as μ or β decays a new class of leptons with its own quantum number is introduced; it includes charged leptons and a ''photonic neutrino''

  7. Interaction of free charged particles with a chirped electromagnetic pulse

    International Nuclear Information System (INIS)

    Khachatryan, A.G.; Goor, F.A. van; Boller, K.-J.

    2004-01-01

    We study the effect of chirp on electromagnetic (EM) pulse interaction with a charged particle. Both the one-dimensional (1D) and 3D cases are considered. It is found that, in contrast to the case of a nonchirped pulse, the charged particle energy can be changed after the interaction with a 1D EM chirped pulse. Different types of chirp and pulse envelopes are considered. In the case of small chirp, an analytical expression is found for arbitrary temporal profiles of the chirp and the pulse envelope. In the 3D case, the interaction with a chirped pulse results in a polarization-dependent scattering of charged particles

  8. Nucleon resonance production in electromagnetic interactions

    International Nuclear Information System (INIS)

    Mukhtarov, A.I.; Sadykhov, F.S.; Vasil'ev, O.A.; Abdullaev, S.K.; Mustafaev, V.Z.

    1977-01-01

    The results of investigation into nucleon resonance production (NR) in the ep → eNsup(*)(eNsup(*)γ) and eantie → antipNsup(*)(antipNsup(*)γ) processes, where Nsup(*) is a nucleon resonance of the 3/2 or 5/2 spin are presented. The calculation of the NR structure functions with the mass M and 3/2 or 5/2 spin is carried out. The Δ(1236), N(1688) and Δ(2160) NR production was observed in the ep → eNsup(*) and eantie → antipNsup(*) processes. For the ep-interaction the energy dependence of the NR production differential cross section at the electron scattering angle THETA = 6 dea and the angular dependence of the longitudinal polarization degree of the scattered electrons at the electron energy of 6 GeV are presented. The energy dependence of the total cross section of the NR production for eantie → antipNsup(*) is obtained. The ep → eNsup(*)γ radiative electron scattering on a proton is investigated only in case of the Δ(1236)NR production. The dependence of the effective cross section of the Δ(1236) radiative production process on THETA for the energies of an incident and scattered electron of 6 and 2.5 GeV, respectively, and the dependence of the cross section on the scattered electron energy at the initial energy of 6 GeV and THETA = 15 deg are presented

  9. A comprehensive treatment of electromagnetic interactions and the three-body spectator equations

    Energy Technology Data Exchange (ETDEWEB)

    Jiri Adam; Jay Van Orden

    2004-10-01

    We present a general derivation the three-body spectator (Gross) equations and the corresponding electromagnetic currents. As in previous paper on two-body systems, the wave equations and currents are derived from those for Bethe-Salpeter equation with the help of algebraic method using a concise matrix notation. The three-body interactions and currents introduced by the transition to the spectator approach are isolated and the matrix elements of the e.m. current are presented in detail for system of three indistinguishable particles, namely for elastic scattering and for two and three body break-up. The general expressions are reduced to the one-boson-exchange approximation to make contact with previous work. The method is general in that it does not rely on introduction of the electromagnetic interaction with the help of the minimal replacement. It would therefore work also for other external fields.

  10. Scalar, electromagnetic, and gravitational fields interaction: Particlelike solutions

    International Nuclear Information System (INIS)

    Bronnikov, K.A.; Melnikov, V.N.; Shikin, G.N.; Staniukovich, K.P.

    1979-01-01

    Particlelike static spherically symmetric solutions to massless scalar and electromagnetic field equations combined with gravitational field equations are considered. Two criteria for particlelike solutions are formulated: the strong one (solutions are required to be singularity free) and the weak one (singularities are admitted but the total energy and material field energy should be finite). Exact solutions for the following physical systems are considered with their own gravitational field: (i) linear scalar (minimally coupled or conformal) plus electromagnetic field; (ii) the same fields with a bare mass source in the form of charged incoherent matter distributions; (iii) nonlinear electromagnetic field with an abritrary dependence on the invariant F/sub alphabeta/F/sup alphabeta/; and (iv) directly interacting scalar and electromagnetic fields. Case (i) solutions are not particlelike (except those with horizons, in which static regions formally satisfy the weak criterion). For systems (ii), examples of nonsingular models are constructed, in particular, a model for a particle--antiparticle pair of a Wheeler-handle type, without scalar field and explict electric charges. Besides, a number of limitations upon nonsingular model parameters is indicated. Systems (iii) are proved to violate the strong criterion for any type of nonlinearity but can satisfy the weak criterion (e.g., the Born--Infeld nonlinearity). For systems (iv) some particlelike solutions by the weak criterion are constructed and a regularizing role of gravitation is demonstrated. Finally, an example of a field system satisfying the strong criterion is given

  11. Electromagnetism

    CERN Document Server

    Grant, Ian S

    1990-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw the Physics of Stars Second Edition A. C. Phillips Computing for Scient

  12. The generalized canonical formalism for the electromagnetic field

    CERN Document Server

    Constantinescu, R

    2001-01-01

    The possibility of the Hamiltonian description of the electromagnetic field as a constrained dynamical system is analyzed. We use the BRST technique and we study the consequences of the implementation of a third order symmetry, that is a symmetry related to the symplectic group sp(3). The connection between this larger symmetry and the standard BRST one is also discussed. The following results are underlined: building a generalized BRST symmetry appears as possible; the standard and the sp(2) theories prove themselves as the first two stages of this global theory. By it, a more extended symmetry asks for a larger ghost spectrum and, so, more nonminimal terms can be employed in the gauge fixing procedure. (authors)

  13. Strong interactions and electromagnetism in low-energy hadron physics

    International Nuclear Information System (INIS)

    Kubis, B.

    2002-10-01

    In the present work, we study various aspects of the entanglement of the strong and electromagnetic interactions as it is manifest in low-energy hadron physics. In the framework of chiral perturbation theory, two aspects are investigated: the test of the structure of baryons as probed by external electromagnetic currents, and the modification of reactions mediated by the strong interactions in the presence of internal (virtual) photons. In the first part of this work, we study the electromagnetic form factors of nucleons and the ground state baryon octet, as well as strangeness form factors of the nucleon. Emphasis is put on the comparison of a new relativistic scheme for the calculation of loop diagrams to the heavy-baryon formalism, and on the convergence of higher-order corrections in both schemes. The new scheme is shown to yield both a phenomenologically more successful description of the data and better convergence behaviour. In the second part, we study isospin violation in pion-kaon scattering as mediated by virtual photon effects and the light quark mass difference. This investigation is of particular importance for the extraction of scattering lengths from measurements of lifetime and energy levels in pion-kaon atoms. The isospin breaking corrections are shown to be small and sufficiently well under control. (orig.)

  14. Lagrange formalism for a system of several fluids interacting electromagnetically

    International Nuclear Information System (INIS)

    Vuillemin, M.

    1964-01-01

    After giving the Lagrange expression for a conducting fluid in an external electromagnetic field, the author shows that a Lagrange expression exists for describing the evolution of a system of interacting fluids obtained by adding the Lagrange expression of each fluid.to that of the electromagnetic field. By variation are obtained the fluid movement equation coupled to the Maxwell equations. It is shown that the study of small movements around a stationary state can be deduced from the Lagrange equation expanded to the second power order of the perturbation. It is then possible to deduce the normal mode equations and the study the stability by examining the modes which are marginally stable. (author) [fr

  15. An integrated model for interaction of electromagnetic fields with biological systems

    International Nuclear Information System (INIS)

    Apollonio, F.; Liberti, M.; Cavagnaro, M.; D'Inzeo, G.; Tarricone, L.

    1999-01-01

    In this work is described a methodology for evaluation of interaction of high frequency electromagnetic field. Biological systems via connection of many macroscopic models. In particular the analysis of neuronal membrane exposed to electromagnetic fields [it

  16. Analysis of transient electromagnetic interactions on nanodevices using a quantum corrected integral equation approach

    KAUST Repository

    Uysal, Ismail Enes; Ulku, Huseyin Arda; Bagci, Hakan

    2015-01-01

    Analysis of electromagnetic interactions on nanodevices can oftentimes be carried out accurately using “traditional” electromagnetic solvers. However, if a gap of sub-nanometer scale exists between any two surfaces of the device

  17. Sensor Interaction as a Source of the Electromagnetic Field Measurement Error

    Directory of Open Access Journals (Sweden)

    Hartansky R.

    2014-12-01

    Full Text Available The article deals with analytical calculation and numerical simulation of interactive influence of electromagnetic sensors. Sensors are components of field probe, whereby their interactive influence causes the measuring error. Electromagnetic field probe contains three mutually perpendicular spaced sensors in order to measure the vector of electrical field. Error of sensors is enumerated with dependence on interactive position of sensors. Based on that, proposed were recommendations for electromagnetic field probe construction to minimize the sensor interaction and measuring error.

  18. Interactions of free electrons with an electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Zel' dovich, Ya B [AN SSSR, Moscow. Inst. Prikladnoj Matematiki

    1975-02-01

    The interaction of a chaotic field of electromagnetic radiation with free electrons in plasma is considered as applied to astrophysical problems, in particular, to the theory of establishing thermodynamic equilibrium of radiation in the hot universe. The kinetic equation describes a change in the spectrum; particular attention is paid to the induced scattering and to the classical interpretation of the induced transfer of energy and momentum. In spectra of radiosources with a high brightness temperature the induced scattering may lead to the Bose condensation of photons, shock wave and appearance of solutions. The scattering of strong low-frequency waves is considered as applied to pulsars and laboratory coherent generators.

  19. Theory of charged vector mesons interacting with the electromagnetic field

    International Nuclear Information System (INIS)

    Lee, T.D.; Yang, C.N.

    1983-01-01

    It is shown that starting from the usual canonical formalism for the electromagnetic interaction of a charged vector meson with arbitrary magnetic moment one is led to a set of rules for Feynman diagrams, which appears to contain terms that are both infinite and noncovariant. These difficulties, however, can be circumvented by introducing a xi-limiting process which depends on a dimensionless positive parameter xi → 0. Furthermore, by using the mathematical artifice of a negative metric the theory becomes renormalizable (for xi > 0)

  20. Particle Dynamics under Quasi-linear Interaction with Electromagnetic Waves

    Energy Technology Data Exchange (ETDEWEB)

    Castejon, F.; Eguilior, S.

    2003-07-01

    Langevin equations for quasi-linear wave particle interaction are obtained taking advantage of the unique vocal equivalence between Fokker-Plank equation and the former ones. Langevin equations are solved numerically and, hence, the evolution of a single particle embedded in an electromagnetic field in momentum space is obtained. The equations are relativistic and valid for any wave. It is also shown that the stochastic part of the equations is negligible in comparison with the deterministic term, except for the momentum to the resonance condition for the main parallel refractive index. (Author) 24 refs.

  1. Particle Dynamics under Quasi-linear Interaction with Electromagnetic Waves

    International Nuclear Information System (INIS)

    Castejon, F.; Eguilior, S.

    2003-01-01

    Langevin equations for quasi-linear wave particle interaction are obtained taking advantage of the unique vocal equivalence between Fokker-Plank equation and the former ones. Langevin equations are solved numerically and, hence, the evolution of a single particle embedded in an electromagnetic field in momentum space is obtained. The equations are relativistic and valid for any wave. It is also shown that the stochastic part of the equations is negligible in comparison with the deterministic term, except for the momentum to the resonance condition for the main parallel refractive index. (Author) 24 refs

  2. Quaternion analysis of generalized electromagnetic fields in chiral media

    International Nuclear Information System (INIS)

    Bisht, P. S. . Email. ps_bisht123@rediffmail.com

    2007-01-01

    The time dependent Maxwell's equations in presence of electric and magnetic charges has been developed in chiral media and the solutions for the classical problem are obtained in unique, simple and consistent manner. The quaternionic reformulation of generalized electromagnetic fields in chiral media has also been developed in compact and consistent way. Simulation of neutron backscattering process applied to organic material detection. Forero Martinez, Nancy Carolina; Cristancho, Fernando (Nuclear Physics Group, Universidad Nacional de Colombia, Bogota D.C. (Colombia)) Abstract Atomic and nuclear physics based sensors might offer new possibilities in de-mining. There is a particular interest in the possibility of using neutrons for the non-intrusive detection of hidden contraband, explosives or illicit drugs. The Neutron Backscattering Technique, based on the detection of the produced thermal neutrons, is known to be a useful tool to detect hidden explosives which present an elevated concentration of light elements (H, C, N, O). In this way we present the simulated results using the program package Geant4. Different variables were modified including the soil composition and the studied materials. (Author)

  3. Breatherlike electromagnetic wave propagation in an antiferromagnetic medium with Dzyaloshinsky-Moriya interaction

    International Nuclear Information System (INIS)

    Kavitha, L.; Saravanan, M.; Srividya, B.; Gopi, D.

    2011-01-01

    We investigate the nature of propagation of electromagnetic waves (EMWs) in an antiferromagnetic medium with Dzyaloshinsky-Moriya (DM) interaction environment. The interplay of bilinear and DM exchange spin coupling with the magnetic field component of the EMW has been studied by solving Maxwell's equations coupled with a nonlinear spin equation for the magnetization of the medium. We made a nonuniform expansion of the magnetization and magnetic field along the direction of propagation of EMW, in the framework of reductive perturbation method, and the dynamics of the system is found to be governed by a generalized derivative nonlinear Schroedinger (DNLS) equation. We employ the Jacobi-elliptic function method to solve the DNLS equation, and the electromagnetic wave propagation in an antiferromagnetic medium is governed by the breatherlike spatially and temporally coherent localized modes under the influence of DM interaction parameter.

  4. Interaction of extremely-low-frequency electromagnetic fields with humans

    International Nuclear Information System (INIS)

    Tenforde, T.S.

    1991-07-01

    At a macroscopic level, the effects of extremely low frequency (ELF) electromagnetic fields on humans are well understood based on fundamental physical principles, but far less is known about the nature of the interactions at a cellular or molecular level. Current evidence suggests the effects of ELF on cellular biochemistry are due to interactions with the cell membrane. Elucidation of the mechanism that underlies this transmembrane signaling is critical for a molecular-level understanding of ELF field effects. Further research is also required to clarify a possible link between ELF exposure and increased cancer risk, since estimated ELF exposure in occupational or residential settings is much lower that the levels used in laboratory studies. There is a clear need for additional epidemiological research in which qualitative dosimetry is used to characterize ELF exposure and careful attention is given to possible effects of confounding variables. 24 refs

  5. New effects in the interaction between electromagnetic sources mediated by nonminimal Lorentz violating interactions

    Energy Technology Data Exchange (ETDEWEB)

    Borges, L.H.C.; Ferrari, A.F. [Universidade Federal do ABC, Centro de Ciencias Naturais e Humanas, Santo Andre, SP (Brazil); Barone, F.A. [Universidade Federal de Itajuba, IFQ, Itajuba, MG (Brazil)

    2016-11-15

    This paper is dedicated to the study of interactions between external sources for the electromagnetic field in the presence of Lorentz symmetry breaking. We focus on a higher derivative, Lorentz violating interaction that arises from a specific model that was argued to lead to interesting effects in the low energy phenomenology of light pseudoscalars interacting with photons. The kind of higher derivative Lorentz violating interaction we discuss are called nonminimal. They are usually expected to be relevant only at very high energies, but we argue they might also induce relevant effects in low energy phenomena. Indeed, we show that the Lorentz violating background considered by us leads to several phenomena that have no counterpart in Maxwell theory, such as nontrivial torques on isolated electric dipoles, as well as nontrivial forces and torques between line currents and point like charges, as well as among Dirac strings and other electromagnetic sources. (orig.)

  6. Interaction of High Intensity Electromagnetic Waves with Plasmas: Final Report

    International Nuclear Information System (INIS)

    Shvets, G.

    2008-01-01

    The focus of our work during the duration of this grant was on the following areas: (a) the fundamental plasma physics of intense laser-plasma interactions, including the nonlinear excitation of plasma waves for accelerator applications, as well as the recently discovered by us phenomenon of the relativistic bi-stability of relativistic plasma waves driven by a laser beatwave; (b) interaction of high power microwave beams with magnetized plasma, including some of the recently discovered by us phenomena such as the Undulator Induced Transparency (UIT) as well as the new approaches to dynamic manipulation of microwave pulses; (c) investigations of the multi-color laser pulse interactions in the plasma, including the recently discovered by us phenomenon of Electromagnetic Cascading (EC) and the effect of the EC of three-dimensional dynamics of laser pulses (enhanced/suppressed selffocusing etc.); (d) interaction of high-current electron beams with the ambient plasma in the context of Fast Ignitor (FI) physics, with the emphasis on the nonlinear dynamics of the Weibel instability and beam filamentation.

  7. Beam equipment electromagnetic interaction in accelerators: simulation and experimental benchmarking

    CERN Document Server

    Passarelli, Andrea; Vaccaro, Vittorio Giorgio; Massa, Rita; Masullo, Maria Rosaria

    One of the most significant technological problems to achieve the nominal performances in the Large Hadron Collider (LHC) concerns the system of collimation of particle beams. The use of collimators crystals, exploiting the channeling effect on extracted beam, has been experimentally demonstrated. The first part of this thesis is about the optimization of UA9 goniometer at CERN, this device used for beam collimation will replace a part of the vacuum chamber. The optimization process, however, requires the calculation of the coupling impedance between the circulating beam and this structure in order to define the threshold of admissible intensity to do not trigger instability processes. Simulations have been performed with electromagnetic codes to evaluate the coupling impedance and to assess the beam-structure interaction. The results clearly showed that the most concerned resonance frequencies are due solely to the open cavity to the compartment of the motors and position sensors considering the crystal in o...

  8. Electromagnetic radiations from laser interaction with gas-filled Hohlraum

    Science.gov (United States)

    Yang, Ming; Yang, Yongmei; Li, Tingshuai; Yi, Tao; Wang, Chuanke; Liu, Shenye; Jiang, Shaoen; Ding, Yongkun

    2018-01-01

    The emission of intensive electromagnetic pulse (EMP) due to laser-target interactions at the ShenGuang-III laser facility has been evaluated by probes. EMP signals measured using the small discone antennas demonstrated two variation trends including a bilateral oscillation wave and a unilateral oscillation wave. The new trend of unilateral oscillation could be attributed to the hohlraum structure and low-Z gas in the hohlraum. The EMP waveform showed multiple peaks when the gas-filled hohlraum was shot by the high-power laser. Comparing the EMP signals with the verification of stimulated Raman scattering energy and hard x-ray energy spectrum, we found that the intensity of EMP signals decreased with the increase of the hohlraum size. The current results are expected to offer preliminary information to study physical processes on laser injecting gas-filled hohlraums in the National Ignition Facility implementation.

  9. Nonresonant interaction of ultrashort electromagnetic pulses with multilevel quantum systems

    Science.gov (United States)

    Belenov, E.; Isakov, V.; Nazarkin, A.

    1994-01-01

    Some features of the excitation of multilevel quantum systems under the action of electromagnetic pulses which are shorter than the inverse frequency of interlevel transitions are considered. It is shown that the interaction is characterized by a specific type of selectivity which is not connected with the resonant absorption of radiation. The simplest three-level model displays the inverse population of upper levels. The effect of an ultrashort laser pulse on a multilevel molecule was regarded as an instant reception of the oscillation velocity by the oscillator and this approach showed an effective excitation and dissociation of the molecule. The estimations testify to the fact that these effects can be observed using modern femtosecond lasers.

  10. Electromagnetic interactions in an electron-hole plasma

    International Nuclear Information System (INIS)

    1977-01-01

    Certain problems electromagnetic interactions both of external SHF radiation with an electron-hole (eh) plasma and in the plasma itself are considered. The production and properties of a non-equilibrium eh plasma in semiconductors, pinch effect in a plasma of solids, strong electric fields in a plasma of inhomogeneous semiconductors and heat effects in a semiconductor plasma are discussed. The influence of a surface, kinetics of recombination processes in the semiconductor volume and the plasma statistics the spatial distribution of carriers, current characteristics and plasma recombination radiation under the conditions of pinch effect is described. The diagnostics methods of the phenomena are presented. The behaviour of diode structures with pn transitions in strong SHF fields is discussed. Special attention is paid to collective phenomena in the plasma of semiconductor devices and the variation of carrier density in strong fields. The appearance of electromotive force in inhomogeneous diode structures placed in strong SHF fields is considered

  11. Open quantum systems and the two-level atom interacting with a single mode of the electromagnetic field

    International Nuclear Information System (INIS)

    Sandulescu, A.; Stefanescu, E.

    1987-07-01

    On the basis of Lindblad theory of open quantum systems we obtain new optical equations for the system of two-level atom interacting with a single mode of the electromagnetic field. The conventional Block equations in a generalized form with field phases are obtained in the hypothesis that all the terms are slowly varying in the rotating frame.(authors)

  12. Interaction of electromagnetic energy with biological material - relation to food processing

    NARCIS (Netherlands)

    Ponne, C.T.; Bartels, P.V.

    1995-01-01

    For food scientists and technologists, the interaction of electromagnetic energy with enzymes, microorganisms and other food compounds is important in optimizing process efficiency and/or product quality. To be able to implement research findings on interaction of electromagnetic energy with matter;

  13. Electromagnetic scattering and emission by a fixed multi-particle object in local thermal equilibrium: General formalism.

    Science.gov (United States)

    Mishchenko, Michael I

    2017-10-01

    The majority of previous studies of the interaction of individual particles and multi-particle groups with electromagnetic field have focused on either elastic scattering in the presence of an external field or self-emission of electromagnetic radiation. In this paper we apply semi-classical fluctuational electrodynamics to address the ubiquitous scenario wherein a fixed particle or a fixed multi-particle group is exposed to an external quasi-polychromatic electromagnetic field as well as thermally emits its own electromagnetic radiation. We summarize the main relevant axioms of fluctuational electrodynamics, formulate in maximally rigorous mathematical terms the general scattering-emission problem for a fixed object, and derive such fundamental corollaries as the scattering-emission volume integral equation, the Lippmann-Schwinger equation for the dyadic transition operator, the multi-particle scattering-emission equations, and the far-field limit. We show that in the framework of fluctuational electrodynamics, the computation of the self-emitted component of the total field is completely separated from that of the elastically scattered field. The same is true of the computation of the emitted and elastically scattered components of quadratic/bilinear forms in the total electromagnetic field. These results pave the way to the practical computation of relevant optical observables.

  14. The ICVSIE: A General Purpose Integral Equation Method for Bio-Electromagnetic Analysis.

    Science.gov (United States)

    Gomez, Luis J; Yucel, Abdulkadir C; Michielssen, Eric

    2018-03-01

    An internally combined volume surface integral equation (ICVSIE) for analyzing electromagnetic (EM) interactions with biological tissue and wide ranging diagnostic, therapeutic, and research applications, is proposed. The ICVSIE is a system of integral equations in terms of volume and surface equivalent currents in biological tissue subject to fields produced by externally or internally positioned devices. The system is created by using equivalence principles and solved numerically; the resulting current values are used to evaluate scattered and total electric fields, specific absorption rates, and related quantities. The validity, applicability, and efficiency of the ICVSIE are demonstrated by EM analysis of transcranial magnetic stimulation, magnetic resonance imaging, and neuromuscular electrical stimulation. Unlike previous integral equations, the ICVSIE is stable regardless of the electric permittivities of the tissue or frequency of operation, providing an application-agnostic computational framework for EM-biomedical analysis. Use of the general purpose and robust ICVSIE permits streamlining the development, deployment, and safety analysis of EM-biomedical technologies.

  15. Models of the Dynamics of Spatially Separated Broadband Electromagnetic Fields Interacting with Resonant Atoms

    Science.gov (United States)

    Basharov, A. M.

    2018-03-01

    The Markov model of spontaneous emission of an atom localized in a spatial region with a broadband electromagnetic field with zero photon density is considered in the conditions of coupling of the electromagnetic field with the broadband field of a neighboring space. The evolution operator of the system and the kinetic equation for the atom are obtained. It is shown that the field coupling constant affects the rate of spontaneous emission of the atom, but is not manifested in the atomic frequency shift. The analytic expression for the radiative decay constant for the atom is found to be analogous in a certain sense to the expression for the decay constant for a singly excited localized ensemble of identical atoms in the conditions when the effect of stabilization of its excited state by the Stark interaction with the vacuum broadband electromagnetic field is manifested. The model is formulated based on quantum stochastic differential equations of the non- Wiener type and the generalized algebra of the Ito differential of quantum random processes.

  16. International symposium on weak and electromagnetic interactions in nuclei

    International Nuclear Information System (INIS)

    Walecka, J.D.

    1989-01-01

    The purpose of the symposium is to study the implications of the Standard Model (and its extensions) in the realm of low-energy physics. The atomic nucleus constitutes a laboratory where these questions can be investigated. Low and medium-energy accelerators, reactors and other facilities continue to play an important role in this field. The electroweak sector of the Standard Model has benefited much from these investigations. Weak and electromagnetic interactions are also used to probe nuclear and hadronic structures and also new states of nuclear matter (the strong sector of the Standard Model). These studies cannot be dissociated from the fundamental questions raised in the realm of high-energy physics, astrophysics and cosmology. The symposium is therefore intended to be a meeting ground for low, medium-, and high-energy physicists, astrophysicists and cosmologists, who are tackling common problems in many different ways. That is the summary. By now most of the expert speakers have come, given their talks, and left, I assume that those of you who are still here would like to have some framework in which to put the things you have heard in the last week, and in addition gain some perspective on where we are and where we are going. That is what I am going to try and do in this talk

  17. Status report on the NSAC Subcommittee on Electromagnetic Interactions

    International Nuclear Information System (INIS)

    Barnes, P.D.

    1983-01-01

    The Subcommittee has formulated its view of the physics program to be pursued in the coming years together with an analysis of the facility parameters that will be required in order to execute the highest priority components of this program. The Subcommittee foresees the opening of a new frontier for the investigation of nuclear phenomena in the momentum transfer range q = 5 to 15 fm -1 and electron energy range up to 4 GeV. Because of the opportunities they offer for fundamental advances using electromagnetic probes, the Subcommittee assigned the highest scientific priority to investigation of hadron structure and two body interactions, three and four body systems, and fundamental symmetries. This is both because of their intrinsic scientific interest and because of the opportunity they offer to study the largely unexplored transition between nucleon-meson and the quark-gluon descriptions of nuclear systems. The Subcommittee strongly recommends the construction of a variable energy electron beam facility capable of operation at both high intensity and high duty factor, and able to achieve an electron energy of about 4 GeV, for the purpose of making coincidence measurements on nuclear targets at large excitation energy and momentum transfer

  18. Resonant Electromagnetic Interaction in Low Energy Nuclear Reactions

    Science.gov (United States)

    Chubb, Scott

    2008-03-01

    Basic ideas about how resonant electromagnetic interaction (EMI) can take place in finite solids are reviewed. These ideas not only provide a basis for conventional, electron energy band theory (which explains charge and heat transport in solids), but they also explain how through finite size effects, it is possible to create many of the kinds of effects envisioned by Giuliano Preparata. The underlying formalism predicts that the orientation of the external fields in the SPAWAR protocolootnotetextKrivit, Steven B., New Energy Times, 2007, issue 21, item 10. http://newenergytimes.com/news/2007/NET21.htm^,ootnotetextSzpak, S.; Mosier-Boss, P.A.; Gordon, F.E. Further evidence of nuclear reactions in the Pd lattice: emission of charged particles. Naturwissenschaften 94,511(2007)..has direct bearing on the emission of high-energy particles. Resonant EMI also implies that nano-scale solids, of a particular size, provide an optimal environment for initiating Low Energy Nuclear Reactions (LENR) in the PdD system.

  19. Effect of electromagnetic radiations from mobile phone base stations on general health and salivary function

    OpenAIRE

    Singh, Kushpal; Nagaraj, Anup; Yousuf, Asif; Ganta, Shravani; Pareek, Sonia; Vishnani, Preeti

    2016-01-01

    Objective: Cell phones use electromagnetic, nonionizing radiations in the microwave range, which some believe may be harmful to human health. The present study aimed to determine the effect of electromagnetic radiations (EMRs) on unstimulated/stimulated salivary flow rate and other health-related problems between the general populations residing in proximity to and far away from mobile phone base stations. Materials and Methods: A total of four mobile base stations were randomly selected from...

  20. Direct chill casting of aluminium alloys under electromagnetic interaction by permanent magnet assembly

    Science.gov (United States)

    Bojarevičs, Andris; Kaldre, Imants; Milgrāvis, Mikus; Beinerts, Toms

    2018-05-01

    Direct chill casting is one of the methods used in industry to obtain good microstructure and properties of aluminium alloys. Nevertheless, for some alloys grain structure is not optimal. In this study, we offer the use of electromagnetic interaction to modify melt convection near the solidification interface. Solidification under various electromagnetic interactions has been widely studied, but usually at low solidification velocity and high thermal gradient. This type of interaction may succeed fragmentation of dendrite arms and transport of solidification nuclei thus leading to improved material structure and properties. Realization of experimental small-scale crystallizer and electromagnetic system has been described in this article.

  1. Introduction to unified theories of weak, electromagnetic and strong interactions - SU(5)

    International Nuclear Information System (INIS)

    Billoire, Alain; Morel, Andre.

    1980-11-01

    These notes correspond to a series of lectures given at Salay during winter 1979-1980. They are meant to be an introduction to the so-called grand unified theories of weak, electromagnetic and strong interactions. In a first part, we recall in a very elementary way the standard SU(2) model of electroweak interactions, putting the emphasis on the questions which are left open by this model and which unified theories help to answer. In part II, we explain in a systematic way how unified theories can be constructed, and develop the SU(5) model in great detail. Other models, like SO(10) and E 6 , are not presented, because SU(5) is the simplest one and has been subject to the deepest investigations up to now. Also it appears that most concepts and general results are not specific to any particular symmetry group [fr

  2. Generalized design formulas for low energy electromagnetic quads

    International Nuclear Information System (INIS)

    Liska, D.J.

    1994-06-01

    This technical note is the result of the quadrupole magnet design efforts that went into the development of proposals for large high-powered linear accelerators such as the Accelerator for Production of Tritium (APT), Accelerator for Base Conversion (of Plutonium) (ABC), and Accelerator for Treatment of (radioactive) Waste (ATW). In all these applications it was necessary to develop designs for numerous (hundreds) of electromagnetic quadrupoles (EMQs). EMQs are required since long-term reliability, radiation damage potential, and large aperture dictate against the use of permanent magnet quadrupoles (PMQs) for these powerful machines. One object of the magnet design effort was to provide a quick, reliable, and easy means of converting raw physics requirements (magnetic impulse, focal length, and boretube aperture) into realistic electrical, cooling, facility interface, and mechanical specifications and configurations--in other words, to easily convert physics requirements to a reliable design that could be drawn on paper, shown to vendors, and presented to peer review committees as a well-developed and believable concept. The empirical formulas that were derived have been gathered together in this technical note. They will be useful for other designers interested in an easy way of coming up with a rather complete mechanical as well as electrical and magnetic design for EMQs. Included are lab tests of designs derived from these formulas and comparisons with other real EMQ designs. These demonstrate the good accuracy of the empirical formulas

  3. Electromagnetic particle-in-cell simulations of the solar wind interaction with lunar magnetic anomalies.

    Science.gov (United States)

    Deca, J; Divin, A; Lapenta, G; Lembège, B; Markidis, S; Horányi, M

    2014-04-18

    We present the first three-dimensional fully kinetic and electromagnetic simulations of the solar wind interaction with lunar crustal magnetic anomalies (LMAs). Using the implicit particle-in-cell code iPic3D, we confirm that LMAs may indeed be strong enough to stand off the solar wind from directly impacting the lunar surface forming a mini-magnetosphere, as suggested by spacecraft observations and theory. In contrast to earlier magnetohydrodynamics and hybrid simulations, the fully kinetic nature of iPic3D allows us to investigate the space charge effects and in particular the electron dynamics dominating the near-surface lunar plasma environment. We describe for the first time the interaction of a dipole model centered just below the lunar surface under plasma conditions such that only the electron population is magnetized. The fully kinetic treatment identifies electromagnetic modes that alter the magnetic field at scales determined by the electron physics. Driven by strong pressure anisotropies, the mini-magnetosphere is unstable over time, leading to only temporal shielding of the surface underneath. Future human exploration as well as lunar science in general therefore hinges on a better understanding of LMAs.

  4. Matrix elements and transition probabilities of interaction of electromagnetic field with a hydrogen-like atom

    International Nuclear Information System (INIS)

    Rajput, B.S.

    1977-01-01

    Using the reduced expansions of second quantized electromagnetic vector potential operator in terms of irreducible representations of Pioncare group in the interaction Hamiltonian, the exact matrix elements of interaction of electromagnetic field with a hydrogenic atom have been derived and the contributions of transitions for different combinations of angular momentum quantum numbers to the transition probabilities of various lines in Lyman-, Balmer-, and Paschen-series have been computed. (author)

  5. Interaction of electromagnetic waves with plasma in the radiation-dominated regime

    International Nuclear Information System (INIS)

    Bulanov, S.V.; Esirkepov, T.Zh.; Koga, J.; Tajima, T.

    2004-01-01

    A study is made of the main regimes of interaction of relativistically strong electromagnetic waves with plasma under conditions in which the radiation from particles plays a dominant role. The discussion is focused on such issues as the generation of short electromagnetic pulses in the interaction of laser light with clusters and highly efficient ion acceleration in a thin plasma slab under the action of the ponderomotive pressure of the wave. An approach is developed for generating superintense electromagnetic pulses by means of up-to-date laser devices

  6. A Generalization of Electromagnetic Fluctuation-Induced Casimir Energy

    Directory of Open Access Journals (Sweden)

    Yi Zheng

    2015-01-01

    Full Text Available Intermolecular forces responsible for adhesion and cohesion can be classified according to their origins; interactions between charges, ions, random dipole—random dipole (Keesom, random dipole—induced dipole (Debye are due to electrostatic effects; covalent bonding, London dispersion forces between fluctuating dipoles, and Lewis acid-base interactions are due to quantum mechanical effects; pressure and osmotic forces are of entropic origin. Of all these interactions, the London dispersion interaction is universal and exists between all types of atoms as well as macroscopic objects. The dispersion force between macroscopic objects is called Casimir/van der Waals force. It results from alteration of the quantum and thermal fluctuations of the electrodynamic field due to the presence of interfaces and plays a significant role in the interaction between macroscopic objects at micrometer and nanometer length scales. This paper discusses how fluctuational electrodynamics can be used to determine the Casimir energy/pressure between planar multilayer objects. Though it is confirmation of the famous work of Dzyaloshinskii, Lifshitz, and Pitaevskii (DLP, we have solved the problem without having to use methods from quantum field theory that DLP resorted to. Because of this new approach, we have been able to clarify the contributions of propagating and evanescent waves to Casimir energy/pressure in dissipative media.

  7. Comparison of electromagnetically induced transparency schemes in semiconductor quantum dot structures: Impact of many-body interactions

    DEFF Research Database (Denmark)

    Houmark-Nielsen, Jakob; Nielsen, Torben Roland; Mørk, Jesper

    2009-01-01

    an important impact on the slow light properties. In the case of the Lambda and V schemes, the minimum required coupling power to achieve slow light is significantly reduced by many-body interactions. V type schemes are found to be generally preferable due to a favorable redistribution of carriers in energy......We investigate the impact of many-body interactions on group-velocity slowdown achieved via electromagnetically induced transparency in quantum dots using three different coupling-probe schemes (ladder, V, and Lambda, respectively). We find that for all schemes many-body interactions have...

  8. Interaction of electromagnetic and acoustic waves in a stochastic atmosphere

    Science.gov (United States)

    Bhatnagar, N.; Peterson, A. M.

    1979-01-01

    In the Stanford radio acoustic sounding system (RASS) an electromagnetic signal is made to scatter from a moving acoustic pulse train. Under a Bragg-scatter condition maximum electromagnetic scattering occurs. The scattered radio signal contains temperature and wind information as a function of the acoustic-pulse position. In this investigation RASS performance is assessed in an atmosphere characterized by the presence of turbulence and mean atmospheric parameters. The only assumption made is that the electromagnetic wave is not affected by stochastic perturbations in the atmosphere. It is concluded that the received radio signal depends strongly on the intensity of turbulence for altitudes of the acoustic pulse greater than the coherence length of propagation. The effect of mean vertical wind and mean temperature on the strength of the received signal is also demonstrated to be insignificant. Mean horizontal winds, however, shift the focus of the reflected electromagnetic energy from its origin, resulting in a decrease in received signal level when a monostatic radio-frequency (RF) system is used. For a bistatic radar configuration with space diversified receiving antennas, the shifting of the acoustic pulse makes possible the remote measurement of the horizontal wind component.

  9. A sophisticated cad tool for the creation of complex models for electromagnetic interaction analysis

    Science.gov (United States)

    Dion, Marc; Kashyap, Satish; Louie, Aloisius

    1991-06-01

    This report describes the essential features of the MS-DOS version of DIDEC-DREO, an interactive program for creating wire grid, surface patch, and cell models of complex structures for electromagnetic interaction analysis. It uses the device-independent graphics library DIGRAF and the graphics kernel system HALO, and can be executed on systems with various graphics devices. Complicated structures can be created by direct alphanumeric keyboard entry, digitization of blueprints, conversion form existing geometric structure files, and merging of simple geometric shapes. A completed DIDEC geometric file may then be converted to the format required for input to a variety of time domain and frequency domain electromagnetic interaction codes. This report gives a detailed description of the program DIDEC-DREO, its installation, and its theoretical background. Each available interactive command is described. The associated program HEDRON which generates simple geometric shapes, and other programs that extract the current amplitude data from electromagnetic interaction code outputs, are also discussed.

  10. Introduction to gauge theories of the strong, weak, and electromagnetic interactions

    International Nuclear Information System (INIS)

    Quigg, C.

    1980-07-01

    The plan of these notes is as follows. Chapter 1 is devoted to a brief evocative review of current beliefs and prejudices that form the context for the discussion to follow. The idea of Gauge Invariance is introduced in Chapter 2, and the connection between conservation laws and symmetries of the Lagrangian is recalled. Non-Abelian gauge field theories are constructed in Chapter 3, by analogy with the familiar case of electromagnetism. The Yang-Mills theory based upon isospin symmetry is constructed explicitly, and the generalization is made to other gauge groups. Chapter 4 is concerned with spontaneous symmetry breaking and the phenomena that occur in the presence or absence of local gauge symmetries. The existence of massless scalar fields (Goldstone particles) and their metamorphosis by means of the Higgs mechanism are illustrated by simple examples. The Weinberg-Salam model is presented in Chapter 5, and a brief resume of applications to experiment is given. Quantum Chromodynamics, the gauge theory of colored quarks and gluons, is developed in Chapter 6. Asymptotic freedom is derived schematically, and a few simple applications of perturbative QCD ae exhibited. Details of the conjectured confinement mechanism are omitted. The strategy of grand unified theories of the strong, weak, and electromagnetic interactions is laid out in Chapter 7. Some properties and consequences of the minimal unifying group SU(5) are presented, and the gauge hierarchy problem is introduced in passing. The final chapter contains an essay on the current outlook: aspirations, unanswered questions, and bold scenarios

  11. Electromagnetic interactions of nucleons and nuclei at low energy and momentum transfer

    International Nuclear Information System (INIS)

    Arenhoevel, H.

    1994-01-01

    In these lectures I concentrate on the manifestation of subnuclear degrees of freedom in terms of meson and isobar degrees of freedom in electromagnetic processes where their presence usually is described in terms of so-called exchange or interaction currents. In Section 2 I first discuss the general properties of the electromagnetic interaction, the gauge conditions and low-energy theorems which follow from gauge invariance, the charge and current density operators for a non-relativistic system of nucleons and the Siegert theorem. In Section 3 I sketch the basic ideas and construction methods for the exchange current operators as effective operators and in Section 4 the model of nuclear isobar configurations introducing explicitly isobar degrees of freedom into the nuclear wave function. The general features of one- and two-photon processes are discussed in Section 5. First the expressions for the cross sections of photoabsorption and electron scattering are reviewed. As a specific but important example, I then discuss the two-body break-up of the deuteron since it permits the cleanest analysis and provides one of the best evidences for the presence of subnuclear degrees of freedom due to its simple two-body structure within the classical nuclear physics framework. This is a unique situation because in more complex nuclei the analysis is often hampered by presently still unavoidable approximations of the many-body problem. I furthermore discuss the role of meson exchange currents in the photonuclear TRK sum rule, in particular, I carefully analyse what determines the enhancement. This section ends with a brief discussion of elastic photon scattering with special emphasis on the low-energy theorem for the scattering amplitude and the sum rule relations for the low-energy parameters. (orig.)

  12. Interaction of the electromagnetic waves and non-magnetized plasmas

    International Nuclear Information System (INIS)

    Sun Aiping; Qiu Xiaoming; Dong Yuying; Li Liqiong

    2002-01-01

    The propagation of electromagnetic waves with 0.5 - 10 GHz in a non-magnetized collisional plasma slab is studied numerically. The change in the absorbed power, reflected power and transmitted power of the electromagnetic wave with collisional frequency of electrons and neutral atoms in plasma from 0.1 - 10 GHz, is calculated, in the condition of the uniform plasma with density of 10 10 or 10 11 cm -3 and depth of 10 cm, and the non-uniform plasma with density distribution of n = n 0 exp[2(z/d-1)] and depth of 10 cm, respectively. The results show that the absorbed power in either uniform or non-uniform plasma is large when the plasma density is large and collision frequency is high, and the peak value is 90%

  13. General Practitioners' Knowledge and Concern about Electromagnetic Fields

    DEFF Research Database (Denmark)

    Berg-Beckhoff, Gabriele; Breckenkamp, Jürgen; Larsen, Pia Veldt

    2014-01-01

    Our aim is to explore general practitioners' (GPs') knowledge about EMF, and to assess whether different knowledge structures are related to the GPs' concern about EMF. Random samples were drawn from lists of GPs in Germany in 2008. Knowledge about EMF was assessed by seven items. A latent class...... analysis was conducted to identify latent structures in GPs' knowledge. Further, the GPs' concern about EMF health risk was measured using a score comprising six items. The association between GPs' concern about EMF and their knowledge was analysed using multiple linear regression. In total 435 (response...... "don't know". There was no association between GPs' latent knowledge classes or between the number of correct answers given by the GPs and their EMF concern, whereas the number of incorrect answers was associated with EMF concern. Greater EMF concern in subjects with more incorrect answers suggests...

  14. Interactions of electromagnetic radiations and reactive oxygen species on skin

    International Nuclear Information System (INIS)

    Ferramola de Sancovich, A.M.; Sancovich, H.A. . E- mail: ferramol@qb.fcen.uba.ar

    2006-01-01

    The energy of electromagnetic radiation is derived from the fusion in the sun of four hydrogen nuclei to form a helium nucleus. The sun radiates energy representing the entire electromagnetic spectrum. Light is a form of electromagnetic radiation: all electromagnetic radiation has wave characteristics and travels at the same speed (c: speed of light). But radiations differ in wavelength (λ). Light energy is transmitted not in a continuum stream but only in individual units or photons: E = h c / λ. Short wave light is more energetic than photons of light of longer wavelength. Ultraviolet radiations (UV) (λ s 200- 400 nm) can be classified in UV A (λ s 315 - 400 nm.); UV B (λ s 280 - 315 nm) and UV C (λ s 2 content in biological systems promotes ROS synthesis. If ROS are not controlled by endogenous antioxidants, cell redox status is affected and tissue damage is produced ('oxidative stress'). ROS induce lipid peroxidation, protein cross-linking, enzyme inhibition, loss of integrity and function of plasmatic and mitochondrial membranes conducing to inflammation, aging, carcinogenesis and cell death. While infra-red radiations lead to noticeable tissue temperature conducing to severe burns, UV A and UV B undercover react with skin chromophores producing photochemical alterations involved in cellular aging and cancer induction. As UV radiations can reach cellular nucleus, DNA can be damage. Human beings need protection from the damaging sunbeams. This is a very important concern of public health. While humans need to protect their skin with appropriate clothing and/or by use of skin sun blocks of broad spectrum, some bacteria that are extensively exposed to sunlight have developed genomic evolution (plasmid-encoded DNA repair system) which confers protection from the damaging effect of UV radiation. (author) [es

  15. How Do Pre-Service Teachers Picture Various Electromagnetic Phenomenon? A Qualitative Study of Pre-Service Teachers' Conceptual Understanding of Fundamental Electromagnetic Interaction

    Science.gov (United States)

    Beer, Christopher P.

    2010-01-01

    This study analyzes the nature of pre-service teachers' conceptual models of various electromagnetic phenomena, specifically electrical current, electrical resistance, and light/matter interactions. This is achieved through the students answering the three questions on electromagnetism using a free response approach including both verbal and…

  16. General practitioners' knowledge and concern about electromagnetic fields.

    Science.gov (United States)

    Berg-Beckhoff, Gabriele; Breckenkamp, Jürgen; Larsen, Pia Veldt; Kowall, Bernd

    2014-12-01

    Our aim is to explore general practitioners' (GPs') knowledge about EMF, and to assess whether different knowledge structures are related to the GPs' concern about EMF. Random samples were drawn from lists of GPs in Germany in 2008. Knowledge about EMF was assessed by seven items. A latent class analysis was conducted to identify latent structures in GPs' knowledge. Further, the GPs' concern about EMF health risk was measured using a score comprising six items. The association between GPs' concern about EMF and their knowledge was analysed using multiple linear regression. In total 435 (response rate 23.3%) GPs participated in the study. Four groups were identified by the latent class analysis: 43.1% of the GPs gave mainly correct answers; 23.7% of the GPs answered low frequency EMF questions correctly; 19.2% answered only the questions relating EMF with health risks, and 14.0% answered mostly "don't know". There was no association between GPs' latent knowledge classes or between the number of correct answers given by the GPs and their EMF concern, whereas the number of incorrect answers was associated with EMF concern. Greater EMF concern in subjects with more incorrect answers suggests paying particular attention to misconceptions regarding EMF in risk communication.

  17. Scalar and electromagnetic fields in the Kazner metric. Interaction as a mechanism of isotronization

    International Nuclear Information System (INIS)

    Krechet, V.G.; Shikin, G.N.

    1981-01-01

    Within the framework of the Willer-de Vitt superspatial quantization the quantum anisotropic cosmological model with interacting, scalar and electromagnetic fields is considered. It is shown that as a result of direct interaction of the scalar and electromagnetic fields isotropization of the model occurs as in the classical case. While comparing the classical and quantum approaches the conclusion is made that in the quantum approach there are states without initial singularity, that fails in the classical approach; both in the quantum and classical approaches there is isotropization of evolution of the interacting field system (in the quantum approach in α, and β), and in both approaches this process is a consequence of direct interaction of the scalar and electromagnetic fields; in the quantum approach, unlike the classical one, there exists isotropization of the considered model at an infinite growth of the scalar field [ru

  18. Some problems in generalized electromagnetic thermoelasticity and wave propagation

    International Nuclear Information System (INIS)

    Mohamed, S.E.S.

    2012-01-01

    The first chapter contains a review of the classical theory of elasticity, the theory of thermodynamics, the theory of uncoupled thermoelasticity, the coupled theory of thermoelasticity, the generalized theory of thermoelasticity with one relaxation time, electromagneto thermoelasticity and an introduction to wave propagation in elastic media. Chapter two is devoted to the study of wave propagation for a problem of an infinitely long solid conducting circular cylinder whose lateral surface is traction free and subjected to a known surrounding temperatures in the presence of a uniform magnetic field in the direction of the axis of the cylinder. Laplace transform techniques are used to derive the solution in the Laplace transform domain. The inversion process is carried out using asymptotic expansions valid for short tines. Numerical results are computed for the temperature, displacement, stress,induced magnetic field and induced electric field distributions. The chapter contains also a study of the wave propagation in the elastic medium. In chapter three, we consider the two-dimensional problem of an infinitely long conducting solid cylinder. The lateral surface of the cylinder is taken to be traction free and is subjected to a known temperature distribution independent of z in the presence of a uniform magnetic field in the direction of the axis of the cylinder. Laplace transform techniques are used. The inversion process is carried out using a numerical method based on Fourier series expansions. Numerical results are computed and represented graphically. The chapter contains also a study of the wave propagation in the elastic medium. In chapter four, we consider a two-dimensional problem for an infinity long cylinder. The lateral surface of the cylinder is taken to be traction free and is subjected to a known temperature distribution independent of φ in the presence of a uniform electric field in the direction of the binomial of the cylinder axis. Laplace and

  19. Interaction of attosecond electromagnetic pulses with atoms: The exactly solvable model

    International Nuclear Information System (INIS)

    Popov, Yu. V.; Kouzakov, K. A.; Vinitsky, S. I.; Gusev, A. A.

    2007-01-01

    We consider the exactly solvable model of interaction of zero-duration electromagnetic pulses with an atom. The model has a number of peculiar properties which are outlined in the cases of a single pulse and two opposite pulses. In perspective, it can be useful in different fields of physics involving interaction of attosecond laser pulses with quantum systems

  20. Effect of frequency variation on electromagnetic pulse interaction with charges and plasma

    NARCIS (Netherlands)

    Khachatryan, A.G.; van Goor, F.A.; Verschuur, Jeroen W.J.; Boller, Klaus J.

    2005-01-01

    The effect of frequency variation (chirp) in an electromagnetic (EM) pulse on the pulse interaction with a charged particle and plasma is studied. Various types of chirp and pulse envelopes are considered. In vacuum, a charged particle receives a kick in the polarization direction after interaction

  1. The Mathematics of Charged Particles interacting with Electromagnetic Fields

    DEFF Research Database (Denmark)

    Petersen, Kim

    In this thesis, we study the mathematics used to describe systems of charged quantum mechanical particles coupled with their classical self-generated electromagnetic field. We prove the existence of a unique local in time solution to the many-body Maxwell-Schrödinger initial value problem expressed...... in Coulomb gauge and we show that the one-body Maxwell-Schrödinger system as well as the related one-body Maxwell-Pauli system both admit travelling wave solutions....

  2. Theoretical & Experimental Research in Weak, Electromagnetic & Strong Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, Satyanarayan [Oklahoma State Univ., Stillwater, OK (United States); Babu, Kaladi [Oklahoma State Univ., Stillwater, OK (United States); Rizatdinova, Flera [Oklahoma State Univ., Stillwater, OK (United States); Khanov, Alexander [Oklahoma State Univ., Stillwater, OK (United States); Haley, Joseph [Oklahoma State Univ., Stillwater, OK (United States)

    2015-09-17

    The conducted research spans a wide range of topics in the theoretical, experimental and phenomenological aspects of elementary particle interactions. Theory projects involve topics in both the energy frontier and the intensity frontier. The experimental research involves energy frontier with the ATLAS Collaboration at the Large Hadron Collider (LHC). In theoretical research, novel ideas going beyond the Standard Model with strong theoretical motivations were proposed, and their experimental tests at the LHC and forthcoming neutrino facilities were outlined. These efforts fall into the following broad categories: (i) TeV scale new physics models for LHC Run 2, including left-right symmetry and trinification symmetry, (ii) unification of elementary particles and forces, including the unification of gauge and Yukawa interactions, (iii) supersummetry and mechanisms of supersymmetry breaking, (iv) superworld without supersymmetry, (v) general models of extra dimensions, (vi) comparing signals of extra dimensions with those of supersymmetry, (vii) models with mirror quarks and mirror leptons at the TeV scale, (viii) models with singlet quarks and singlet Higgs and their implications for Higgs physics at the LHC, (ix) new models for the dark matter of the universe, (x) lepton flavor violation in Higgs decays, (xi) leptogenesis in radiative models of neutrino masses, (xii) light mediator models of non-standard neutrino interactions, (xiii) anomalous muon decay and short baseline neutrino anomalies, (xiv) baryogenesis linked to nucleon decay, and (xv) a new model for recently observed diboson resonance at the LHC and its other phenomenological implications. The experimental High Energy Physics group has been, and continues to be, a successful and productive contributor to the ATLAS experiment at the LHC. Members of the group performed search for gluinos decaying to stop and top quarks, new heavy gauge bosons decaying to top and bottom quarks, and vector-like quarks

  3. Nonlinear interaction of powerful short electromagnetic pulses with an electron plasma

    International Nuclear Information System (INIS)

    Rao, N.N.; Yu, M.Y.; Shukla, P.K.

    1990-01-01

    The nonlinear interaction of powerful short electromagnetic pulses with a plasma consisting of two groups of electrons and immobile ions has been studied. It is shown that the interaction is governed by a nonlinear equation for the electromagnetic wave envelope and a driven nonlinear equation for the low-frequency electron fluctuations. The driver for the latter depends explicitly on the spatio-temporal evolution of the electromagnetic wave flux. It is found that, depending on the cold-to-hot electron density ratio, the localized pulse can propagate with sub- as well as supersonic velocities accompanied by compressional or rarefactional density perturbations. The conditions of existence for the different types of solitary pulses are obtained. The present investigation may be relevant to the study of wave-plasma interaction devices such as inertial fusion confinement as well as to ionospheric modification experiments. (author)

  4. Low-frequency electromagnetic radiation field interaction with cerebral nervous MT

    International Nuclear Information System (INIS)

    Gao Feng; Zhou Yi; Xiao Detao; Zhang Dengyu

    2009-01-01

    We investigate the interaction characteristics and mechanism of electromagnetic radiation field and cerebral nervous system. When the electromagnetic radiation is non-ionization low-frequency electromagnetic field, the two-state physical system in the cytoskeletal microtubule (MT) can be quantized. The state of information bits in cerebral neurons system is described by density matrix, and the system dynamics equation is established and solved. It indicates that when the brain is exposed to non-ionization low-frequency electromagnetic field, the density matrix non-opposite angle element of cerebral nervous qubit will never be zero, its quantum coherence characteristic can keep well, and the brain function will also be not damaged. (authors)

  5. The Effect of Electromagnetic Waves on the General Health of Zahedan Gas Power Plant Personnel

    Directory of Open Access Journals (Sweden)

    Fereydoon Laal

    2016-08-01

    Full Text Available Abstract Introduction: With ever improving technology and increasing the use of high voltage power in industrial environments, concerns about the destructive effects of electromagnetic waves on human health have increased. Thus the present study aims to evaluate the effects of electromagnetic waves on the general health of Zahedan gas power plant personnel. Materials & Method: The present case-control study investigated the health of people at one point of time and their amount of exposure to electromagnetic waves at the same time. The data collection tool in this study was 28-item general health questionnaire (GHQ-28. After measuring the electromagnetic waves at distances of 1, 1.5 and 3 meters at high voltage power substations and data extraction, the data were entered to SPSS software and analyzed by descriptive statistics, t-test and chi-square. Results: In this study, the age and experience variables were not significantly different in two groups (p> 0.05. The highest magnetic fields in high voltage power substations was at a distance of 1 meter in the substation 607 (28/1 mG and in precision tool work units (7.03 mG. The results showed that the depressive and general health symptoms were significantly different between the exposed and unexposed groups (p = 0.04, however the difference was not significant in terms of physical performance, anxiety and social performance (p> 0.05. Conclusion: although the level of exposure was lower than standard level determined in Iran, the significant difference of the general health and depression between the two groups, explains the necessity of conducting more studies in this regard. Also by reducing the exposure time and increasing people’s awareness it is possible to take important steps to reduce exposure and complications.

  6. Effect of electromagnetic radiations from mobile phone base stations on general health and salivary function.

    Science.gov (United States)

    Singh, Kushpal; Nagaraj, Anup; Yousuf, Asif; Ganta, Shravani; Pareek, Sonia; Vishnani, Preeti

    2016-01-01

    Cell phones use electromagnetic, nonionizing radiations in the microwave range, which some believe may be harmful to human health. The present study aimed to determine the effect of electromagnetic radiations (EMRs) on unstimulated/stimulated salivary flow rate and other health-related problems between the general populations residing in proximity to and far away from mobile phone base stations. A total of four mobile base stations were randomly selected from four zones of Jaipur, Rajasthan, India. Twenty individuals who were residing in proximity to the selected mobile phone towers were taken as the case group and the other 20 individuals (control group) who were living nearly 1 km away in the periphery were selected for salivary analysis. Questions related to sleep disturbances were measured using Pittsburgh Sleep Quality Index (PSQI) and other health problems were included in the questionnaire. Chi-square test was used for statistical analysis. It was unveiled that a majority of the subjects who were residing near the mobile base station complained of sleep disturbances, headache, dizziness, irritability, concentration difficulties, and hypertension. A majority of the study subjects had significantly lesser stimulated salivary secretion (P base stations on the health and well-being of the general population cannot be ruled out. Further studies are warranted to evaluate the effect of electromagnetic fields (EMFs) on general health and more specifically on oral health.

  7. Study of interaction of electromagnetic waves with thin rotating cylindrical shell of conductor in vicinity of weakly gravitating string

    International Nuclear Information System (INIS)

    Muminov, A.T.

    2004-01-01

    Full text: As it shown in the work [1,2], interaction of electromagnetic wave with rotating cylindrical shell of conductor leads to an interesting phenomenon of energy transmission from rotating body to the wave. We study influence of the gravitational field of the string on the process of interaction of electromagnetic waves with infinitesimally thin conducting cylindrical shell. Since in the outer space and inside the shell electromagnetic field satisfies source free Maxwell equations we start with constructing the most general solutions of this equation. Then we match the fields on the cylinder with account of boundary conditions on it. Matching the fields gives expressions for reflection factors of cylindrical waves for two cases of polarization. The reflection factors for distinct wave polarizations show the ratio of outgoing energy flux to in going one. Curved cylindrical symmetric space-time with weakly gravitating string-like source is described by static metric: δs 2 = f(r)δt 2 - h(r)(δz 2 + δr 2 ) - l(r)δψ 2 ; f(r) = r ε ; h(r) = r -ε ; l(r) = r 2 /f(r). Which corresponds to low line density of mass ε on the string. The metric is particular case of Lewis metric [3,4] with zero angular momentum of the string and its weak gravity. The boundary value problem for electromagnetic waves interaction with thin conducting rotating cylindrical shell in static cylindrical metric with weakly gravitating string has been solved analytically. It is found that character of dependence of the factors on Ω at ω R<<1 and ΩR<<1 approximation remains the same as in flat space-time ε =0. Analysis of expressions for the reflection factors in frames of considered approximation has been done

  8. Electromagnetic and structural interaction analysis of curved shell structures

    International Nuclear Information System (INIS)

    Horie, T.; Niho, T.

    1993-01-01

    This paper describes a finite element formulation of the eddy current and structure coupled problem for curved shell structures. Coupling terms produced by curved geometry as well as flat plate geometry were obtained. Both matrix equations for eddy current and structure were solved simultaneously using coupling sub-matrices. TEAM Workshop bench mark problem 16 was solved to verify the formulation and the computer code. Agreement with experimental results was very good for such plate problem. A coupled problem for cylindrical shell structure was also analyzed. Influence of each coupling term was examined. The next topic is the eigenvalues of the coupled equations. Although the coupled matrix equations are not symmetric, symmetry was obtained by introducing a symmetrizing variable. The eigenvalues of the coupled matrix equations are different from those obtained from the uncoupled equations because of the influence of the coupling sub-matrix components. Some parameters obtained by the eigenvalue analysis have characteristics of parameters which indicate the intensity of electromagnetic structural coupling effect. (author)

  9. Compilations and evaluations of data on the interaction of electromagnetic radiation with matter

    International Nuclear Information System (INIS)

    Lorenz, A.

    1978-05-01

    The material contained in this report deals with data on the interaction of electromagnetic radiation with matter, listing major compilations of X-ray, photon and gamma-ray cross sections and attentuation coefficients, as well as selected reports featuring data on compton scattering, photoelectric absorption and pair production

  10. Random model of two-level atoms interacting with electromagnetic field

    International Nuclear Information System (INIS)

    Kireev, A.N.; Meleshko, A.N.

    1983-12-01

    A phase transition has been studied in a random system of two-level atoms interacting with an electromagnetic field. It is shown that superradiation can arise when there is short-range order in a spin-subsystem. The existence of long-range order is irrelevant for this phase transition

  11. Introduction to the gauge theories unifying the electromagnetic and weak interactions

    International Nuclear Information System (INIS)

    Pham Xuan-Yem.

    An elementary introduction to unified gauge theories of electromagnetic and weak interactions is presented. The Goldstone theorem and the Higgs mechanism are discussed. The Weinberg-Salam model as well as the Georgi-Glashow ones are explained in details. One emphasizes on the experimental consequences of the Weinberg-Salam model (neutral current) [fr

  12. The electro-magnetic transition properties in the microscopic SDG interacting boson model

    International Nuclear Information System (INIS)

    Han Guangze; Liu Yong; Sang Jianping

    1996-01-01

    A bosonic method and the corresponding fermionic one for studying the electro-magnetic transition properties of nucleus are presented in the microscopic sdg interacting boson model. The methods are applied to the nucleus 60 Ni. Detailed discussions are made with the calculated results

  13. A general electromagnetic excitation model for electrical machines considering the magnetic saturation and rub impact

    Science.gov (United States)

    Xu, Xueping; Han, Qinkai; Chu, Fulei

    2018-03-01

    The electromagnetic vibration of electrical machines with an eccentric rotor has been extensively investigated. However, magnetic saturation was often neglected. Moreover, the rub impact between the rotor and stator is inevitable when the amplitude of the rotor vibration exceeds the air-gap. This paper aims to propose a general electromagnetic excitation model for electrical machines. First, a general model which takes the magnetic saturation and rub impact into consideration is proposed and validated by the finite element method and reference. The dynamic equations of a Jeffcott rotor system with electromagnetic excitation and mass imbalance are presented. Then, the effects of pole-pair number and rubbing parameters on vibration amplitude are studied and approaches restraining the amplitude are put forward. Finally, the influences of mass eccentricity, resultant magnetomotive force (MMF), stiffness coefficient, damping coefficient, contact stiffness and friction coefficient on the stability of the rotor system are investigated through the Floquet theory, respectively. The amplitude jumping phenomenon is observed in a synchronous generator for different pole-pair numbers. The changes of design parameters can alter the stability states of the rotor system and the range of parameter values forms the zone of stability, which lays helpful suggestions for the design and application of the electrical machines.

  14. Electromagnetic characterization of bianisotropic metasurfaces on refractive substrates: General theoretical framework

    Energy Technology Data Exchange (ETDEWEB)

    Albooyeh, M.; Tretyakov, Sergei [Department of Radio Science and Engineering, Aalto University, P.O. Box 13000, FI-00076, Aalto (Finland); Simovski, Constantin [Department of Radio Science and Engineering, Aalto University, P.O. Box 13000, FI-00076, Aalto (Finland); Laboratory of Metamaterials, University for Information Technology, Mechanics and Optics (ITMO), 197101, St. Petersburg (Russian Federation)

    2016-10-15

    We present a general methodology for electromagnetic homogenization and characterization of bianisotropic metasurfaces formed by regular or random arrangements of small arbitrary inclusions at interfaces of two different isotropic media. The approach unites and generalizes the earlier theories developed independently by two joint research groups: that of profs. Holloway and Kuester and that of profs. Simovski and Tretyakov. We analyze the features of both formalisms and discuss their peculiarities in several example cases. Our theory can be used in the analysis and synthesis of a wide spectrum of metasurfaces. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Measurement of electromagnetic pulses generated during interactions of high power lasers with solid targets

    International Nuclear Information System (INIS)

    De Marco, M.; Krása, J.; Margarone, D.; Giuffrida, L.; Vrana, R.; Velyhan, A.; Korn, G.; Weber, S.; Cikhardt, J.; Pfeifer, M.; Krouský, E.; Ullschmied, J.; Ahmed, H.; Borghesi, M.; Kar, S.; Limpouch, J.; Velardi, L.; Side, D. Delle; Nassisi, V.

    2016-01-01

    A target irradiated with a high power laser pulse, blows off a large amount of charge and as a consequence the target itself becomes a generator of electromagnetic pulses (EMP) owing to high return current flowing to the ground through the target holder. The first measurement of the magnetic field induced by the neutralizing current reaching a value of a few kA was performed with the use of an inductive target probe at the PALS Laser Facility (Cikhardt et al. Rev. Sci. Instrum. 85 (2014) 103507). A full description of EMP generation should contain information on the spatial distribution and temporal variation of the electromagnetic field inside and outside of the interaction chamber. For this reason, we consider the interaction chamber as a resonant cavity in which different modes of EMP oscillate for hundreds of nanoseconds, until the EMP is transmitted outside through the glass windows and EM waves are attenuated. Since the experimental determination of the electromagnetic field distribution is limited by the number of employed antennas, a mapping of the electromagnetic field has to be integrated with numerical simulations. Thus, this work reports on a detailed numerical mapping of the electromagnetic field inside the interaction chamber at the PALS Laser Facility (covering a frequency spectrum from 100 MHz to 3 GHz) using the commercial code COMSOL Multiphysics 5.2. Moreover we carried out a comparison of the EMP generated in the parallelepiped-like interaction chamber used in the Vulcan Petawatt Laser Facility at the Rutherford Appleton Laboratory, against that produced in the spherical interaction chamber of PALS.

  16. Brewster angle for an E-polarized electromagnetic wave interacting with a moving dielectric medium

    International Nuclear Information System (INIS)

    Mukherjee, P.K.

    1977-01-01

    The Brewster-angle phenomena of total transmission has been investigated with reference to an E-polarized electromagnetic wave interacting with a dielectric half-space moving along the interface. Analytic conditions are derived for the existence of Brewster angles. We also discuss how the Brewster angles are modified by replacing the incident region (in which the incident electromagnetic wave is propagated) with an isotropic or a uniaxially anisotropic plasma. The Brewster angles are found to behave in a remarkably different fashion under various conditions. Numerical results for the Brewster angles, showing their dependence on the nondimensional velocity of the medium β, are presented for several values of the physical parameters

  17. Probing non nucleonic degrees of freedom with strong and electromagnetic interactions

    International Nuclear Information System (INIS)

    Frois, B.

    1985-10-01

    In this talk, I would like to examine our present view on non-nucleonic degrees of freedom with a few typical experimental results obtained recently both with hadronic and electromagnetic probes at intermediate energies. It is the first generation of experimental data which has probed mesonic degrees of freedom with a spatial resolution of the order of 0.5 fm. This has made possible for example the measurement of the size of the pion-nucleon interaction region. This is very stimulating progress and we begin to have a coherent overview on the various reaction mechanisms which are induced by hadronic and electromagnetic probes

  18. Interaction of the superconducting domains induced by external electric field with electromagnetic waves

    International Nuclear Information System (INIS)

    Shapiro, B.Y.

    1992-01-01

    The behavior of a superconductor in time-independent electric field perpendicular to the surface and in the external electromagnetic wave is theoretically investigated. A new type of the resonance interaction between superconducting domains localized along the magnetic field (if the superconducting phase transition takes place in the external magnetic field perpendicular to the surface) and electromagnetic waves is predicted. The surface impedance of the superconductor with domains is calculated. It is shown that the real part of the impedance has a saturation if the skin length equals the domain size. (orig.)

  19. EFFECTS OF NEUTRINO ELECTROMAGNETIC FORM FACTORS ON NEUTRINO INTERACTION WITH FINITE TEMPERATURE ELECTRON MATTERS

    Directory of Open Access Journals (Sweden)

    Anto Sulaksono

    2011-11-01

    Full Text Available The differential cross-section of neutrino interaction with dense and warm electron gasses has been calculated by takinginto account the neutrino electromagnetic form factors. The significant effect of electromagnetic properties of neutrinocan be found if the neutrino dipole moment, μ ν , is ≥ 5.10-9 μB and neutrino charge radius, Rv, is ≥ 5.10-6 MeV-1. Theimportance of the retarded correction, detailed balance and Pauli blocking factors is shown and analyzed. Many-bodyeffects on the target matter which are included via random phase approximation (RPA correlation as well as photoneffective mass are also investigated.

  20. Electromagnetic microwaves in metal films with electron-phonon interaction and a dc magnetic field

    DEFF Research Database (Denmark)

    Hasselberg, L.E.

    1976-01-01

    A quantum-mechanical treatment of electromagnetic microwaves is performed for a metal film. The directions of the exterior ac and dc fields are taken to be arbitrary and boundary conditions for the electrons are assumed to be specular. The relation between the current and the electromagnetic field...... in the transmission spectrum can perhaps be obtained by assuming a finite Debye temperature and specular reflections of the electrons at the boundary surfaces. A sharp peak entirely caused by the finite electron-phonon interaction is also discussed....

  1. Inelastic processes and interference effects during the interaction of positronium with ultrashort electromagnetic pulses

    Energy Technology Data Exchange (ETDEWEB)

    Eseev, M. K., E-mail: m_eseev@mail.ru; Matveev, V. I., E-mail: matveev.victor@pomorsu.ru [Lomonosov Northern (Arctic) Federal University (Russian Federation)

    2013-11-15

    The excitation, breakup, and reradiation during the interaction of a positronium atom with ultrashort electromagnetic pulses are considered. The probabilities of inelastic processes and reradiation spectra have been obtained. The interference between the amplitudes of the photon emission by the electron and positron is shown to contribute noticeably to the reradiation spectra. The developed approach is applicable for describing the interaction of positronium with ultrashort pulses of attosecond or shorter duration.

  2. Neoclassical theory of electromagnetic interactions a single theory for macroscopic and microscopic scales

    CERN Document Server

    Babin, Anatoli

    2016-01-01

    In this monograph, the authors present their recently developed theory of electromagnetic interactions. This neoclassical approach extends the classical electromagnetic theory down to atomic scales and allows the explanation of various non-classical phenomena in the same framework. While the classical Maxwell–Lorentz electromagnetism theory succeeds in describing the physical reality at macroscopic scales, it struggles at atomic scales. Here, quantum mechanics traditionally takes over to describe non-classical phenomena such as the hydrogen spectrum and de Broglie waves. By means of modifying the classical theory, the approach presented here is able to consistently explain quantum-mechanical effects, and while similar to quantum mechanics in some respects, this neoclassical theory also differs markedly from it. In particular, the newly developed framework omits probabilistic interpretations of the wave function and features a new fundamental spatial scale which, at the size of the free electron, is much lar...

  3. Emergent spin electromagnetism induced by magnetization textures in the presence of spin-orbit interaction (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Tatara, Gen, E-mail: gen.tatara@riken.jp [RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198 Japan (Japan); Nakabayashi, Noriyuki [RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198 Japan (Japan); Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 Japan (Japan)

    2014-05-07

    Emergent electromagnetic field which couples to electron's spin in ferromagnetic metals is theoretically studied. Rashba spin-orbit interaction induces spin electromagnetic field which is in the linear order in gradient of magnetization texture. The Rashba-induced effective electric and magnetic fields satisfy in the absence of spin relaxation the Maxwell's equations as in the charge-based electromagnetism. When spin relaxation is taken into account besides spin dynamics, a monopole current emerges generating spin motive force via the Faraday's induction law. The monopole is expected to play an important role in spin-charge conversion and in the integration of spintronics into electronics.

  4. Analysis of transient electromagnetic interactions on nanodevices using a quantum corrected integral equation approach

    KAUST Repository

    Uysal, Ismail Enes

    2015-10-26

    Analysis of electromagnetic interactions on nanodevices can oftentimes be carried out accurately using “traditional” electromagnetic solvers. However, if a gap of sub-nanometer scale exists between any two surfaces of the device, quantum-mechanical effects including tunneling should be taken into account for an accurate characterization of the device\\'s response. Since the first-principle quantum simulators can not be used efficiently to fully characterize a typical-size nanodevice, a quantum corrected electromagnetic model has been proposed as an efficient and accurate alternative (R. Esteban et al., Nat. Commun., 3(825), 2012). The quantum correction is achieved through an effective layered medium introduced into the gap between the surfaces. The dielectric constant of each layer is obtained using a first-principle quantum characterization of the gap with a different dimension.

  5. The significance of a new correspondence principle for electromagnetic interaction in strong optical field ionisation

    International Nuclear Information System (INIS)

    Boreham, B. W.; Hora, H.

    1997-01-01

    We have recently developed a correspondence principle for electromagnetic interaction. When applied to laser interactions with electrons this correspondence principle identifies a critical laser intensity I*. This critical intensity is a transition intensity separating classical mechanical and quantum mechanical interaction regimes. In this paper we discuss the further application of I* to the interaction of bound electrons in atoms. By comparing I* with the ionisation threshold intensities as calculated from a cycle-averaged simple-atom model we conclude that I* can be usefully interpreted as a lower bound to the classical regime in studies of ionisation of gas atoms by intense laser beams

  6. Neutron star equilibrium configurations within a fully relativistic theory with strong, weak, electromagnetic, and gravitational interactions

    International Nuclear Information System (INIS)

    Belvedere, Riccardo; Pugliese, Daniela; Rueda, Jorge A.; Ruffini, Remo; Xue, She-Sheng

    2012-01-01

    We formulate the equations of equilibrium of neutron stars taking into account strong, weak, electromagnetic, and gravitational interactions within the framework of general relativity. The nuclear interactions are described by the exchange of the σ, ω, and ρ virtual mesons. The equilibrium conditions are given by our recently developed theoretical framework based on the Einstein–Maxwell–Thomas–Fermi equations along with the constancy of the general relativistic Fermi energies of particles, the “Klein potentials”, throughout the configuration. The equations are solved numerically in the case of zero temperatures and for selected parameterizations of the nuclear models. The solutions lead to a new structure of the star: a positively charged core at supranuclear densities surrounded by an electronic distribution of thickness ∼ℏ/(m e c)∼10 2 ℏ/(m π c) of opposite charge, as well as a neutral crust at lower densities. Inside the core there is a Coulomb potential well of depth ∼m π c 2 /e. The constancy of the Klein potentials in the transition from the core to the crust, imposes the presence of an overcritical electric field ∼(m π /m e ) 2 E c , the critical field being E c =m e 2 c 3 /(eℏ). The electron chemical potential and the density decrease, in the boundary interface, until values μ e crust e core and ρ crust core . For each central density, an entire family of core–crust interface boundaries and, correspondingly, an entire family of crusts with different mass and thickness, exist. The configuration with ρ crust =ρ drip ∼4.3×10 11 gcm −3 separates neutron stars with and without inner crust. We present here the novel neutron star mass–radius for the especial case ρ crust =ρ drip and compare and contrast it with the one obtained from the traditional Tolman–Oppenheimer–Volkoff treatment.

  7. A Theory of Gravity and General Relativity based on Quantum Electromagnetism

    Science.gov (United States)

    Zheng-Johansson, J. X.

    2018-02-01

    Based on first principles solutions in a unified framework of quantum mechanics and electromagnetism we predict the presence of a universal attractive depolarisation radiation (DR) Lorentz force (F) between quantum entities, each being either an IED matter particle or light quantum, in a polarisable dielectric vacuum. Given two quantum entities i = 1, 2 of either kind, of characteristic frequencies ν _i^0, masses m_i0 = hν _i^0/{c^2} and separated at a distance r 0, the solution for F is F = - G}m_1^0m_2^0/{≤ft( {{r^2}} \\right)^2}, where G} = χ _0^2{e^4}/12{π ^2} \\in _0^2{ρ _λ };{χ _0} is the susceptibility and π λ is the reduced linear mass density of the vacuum. This force F resembles in all respects Newton’s gravity and is accurate at the weak F limit; hence ℊ equals the gravitational constant G. The DR wave fields and hence the gravity are each propagated in the dielectric vacuum at the speed of light c; these can not be shielded by matter. A test particle µ of mass m 0 therefore interacts gravitationally with all of the building particles of a given large mass M at r 0 apart, by a total gravitational force F = -GMm 0/(r 0)2 and potential V = -∂F/∂r 0. For a finite V and hence a total Hamiltonian H = m 0 c 2 + V, solution for the eigenvalue equation of µ presents a red-shift in the eigen frequency ν = ν 0(1 - GM/r 0 c 2) and hence in other wave variables. The quantum solutions combined with the wave nature of the gravity further lead to dilated gravito optical distance r = r 0/(1 - GM/r 0 c 2) and time t = t 0/(1 - GM/r 0 c 2), and modified Newton’s gravity and Einstein’s mass energy relation. Applications of these give predictions of the general relativistic effects manifested in the four classical test experiments of Einstein’s general relativity (GR), in direct agreement with the experiments and the predictions given based on GR.

  8. Inelastic Processes in the Interaction of an Atom with an Ultrashort Electromagnetic Pulse

    International Nuclear Information System (INIS)

    Matveev, V.I.; Gusarevich, E.S.; Pashev, I.N.

    2005-01-01

    Electron transitions occurring during the interaction of a heavy relativistic atom with a spatially inhomogeneous ultrashort electromagnetic pulse are considered by solving the Dirac equation. The corresponding transition probabilities are expressed in terms of known inelastic atomic form factors, which are widely used in the theory of relativistic collisions between charged particles and atoms. By way of example, the inelastic processes accompanying the interaction of ultrashort pulses with hydrogen-like atoms are considered. The probabilities of ionization and production of a bound-free electron-positron pair on a bare nucleus, which are accompanied by the formation of a hydrogen-like atom in the final state and a positron in the continuum, are calculated. The developed technique makes it possible to take into account exactly not only the spatial inhomogeneity of an ultrashort electromagnetic pulse, but also the magnetic interaction

  9. Inelastic processes in interaction of an atom with ultrashort pulse of an electromagnetic field

    International Nuclear Information System (INIS)

    Matveev, V.I.; Gusarevich, E.S.; Pashev, I.N.

    2005-01-01

    Electron transitions occurring when a heavy relativistic atom interacts with a spatially inhomogeneous ultrashort electromagnetic pulse are considered. Transition probabilities are expressed in terms of the known inelastic atomic form factors. By way of example, the inelastic processes accompanying the interaction of ultrashort pulses with hydrogen-like atoms are considered. The probabilities of ionization and production of a bound-free electron-positron pair on a bare nucleus, which are accompanied by the formation of a hydrogen-like atom in the final state and a positron in the continuum, are calculated. The developed technique makes it possible to take into exact account magnetic interaction besides spatial inhomogeneity of an ultrashort electromagnetic pulse [ru

  10. Some preliminary views of plasma interaction: electromagnetic-launch systems

    International Nuclear Information System (INIS)

    Buckingham, A.C.; Hawke, R.S.

    1982-01-01

    This discussion outlines a few areas of fundamental research which appear vital for progress in developing advanced propulsion concepts using dc railgun thrusters. We have placed emphasis on the following: (1) dense plasma and high current density influences on changes in microstructure and properties of conventional rail conductors such as Cu, Al, and W alloys or composites; (2) the influences described in (1) on more advanced high temperature, microstrain resistant, materials such as amorphous tungsten; (3) location, description and temporal evolution of current, magnetic field, and losses during intense plasma-current field interactions with conductors; and (4) composite materials and sequentially sectioned structures for more efficient EM dc launcher configuration

  11. Near-field electromagnetic holography for high-resolution analysis of network interactions in neuronal tissue.

    Science.gov (United States)

    Kjeldsen, Henrik D; Kaiser, Marcus; Whittington, Miles A

    2015-09-30

    Brain function is dependent upon the concerted, dynamical interactions between a great many neurons distributed over many cortical subregions. Current methods of quantifying such interactions are limited by consideration only of single direct or indirect measures of a subsample of all neuronal population activity. Here we present a new derivation of the electromagnetic analogy to near-field acoustic holography allowing high-resolution, vectored estimates of interactions between sources of electromagnetic activity that significantly improves this situation. In vitro voltage potential recordings were used to estimate pseudo-electromagnetic energy flow vector fields, current and energy source densities and energy dissipation in reconstruction planes at depth into the neural tissue parallel to the recording plane of the microelectrode array. The properties of the reconstructed near-field estimate allowed both the utilization of super-resolution techniques to increase the imaging resolution beyond that of the microelectrode array, and facilitated a novel approach to estimating causal relationships between activity in neocortical subregions. The holographic nature of the reconstruction method allowed significantly better estimation of the fine spatiotemporal detail of neuronal population activity, compared with interpolation alone, beyond the spatial resolution of the electrode arrays used. Pseudo-energy flow vector mapping was possible with high temporal precision, allowing a near-realtime estimate of causal interaction dynamics. Basic near-field electromagnetic holography provides a powerful means to increase spatial resolution from electrode array data with careful choice of spatial filters and distance to reconstruction plane. More detailed approaches may provide the ability to volumetrically reconstruct activity patterns on neuronal tissue, but the ability to extract vectored data with the method presented already permits the study of dynamic causal interactions

  12. Gauge and general covariance of string interactions

    International Nuclear Information System (INIS)

    Das, S.R.

    1986-01-01

    All fundamental interactions at observable energies seem to arise out of local symmetries - gauge invariances and general coordinate invariance. In usual field theories of point particles these invariances are postulated a priori: the idea is to deduce everything else from the symmetry group and the representation content of the matter fields. In string theories, the situation is rather different. Here the basic principle is reparametrization invariance on the world sheet swept out by the string. The authors consider the simplest string models-those defined on flat Minkowski space-time. The transverse oscillations of the string lead to an infinite tower of modes which may be thought of as the ''particles'' constituting the string. The interacting string theory is defined, in the first quantized formulation, by specifying the interaction of these modes with the string. These interaction vertices must satisfy a basic requirement: when any dual amplitude is factorized only physical states (i.e. those satisfying the Virasoro conditions) must occur as on-mass-shell intermediate states. This means that the vertices respect the reparametrization invariance of the world sheet, since it is this symmetry which eliminates ghost states by virtue of Virasoro conditions

  13. The Impact of Computer Simulations as Interactive Demonstration Tools on the Performance of Grade 11 Learners in Electromagnetism

    Science.gov (United States)

    Kotoka, Jonas; Kriek, Jeanne

    2014-01-01

    The impact of computer simulations on the performance of 65 grade 11 learners in electromagnetism in a South African high school in the Mpumalanga province is investigated. Learners did not use the simulations individually, but teachers used them as an interactive demonstration tool. Basic concepts in electromagnetism are difficult to understand…

  14. Electromagnetic Structure and Electron Acceleration in Shock–Shock Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Nakanotani, Masaru [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Koen, Kasuga, Fukuoka, 816-8580 (Japan); Matsukiyo, Shuichi; Hada, Tohru [Faculty of Engineering Sciences, Kyushu University, 6-1 Kasuga-Koen, Kasuga, Fukuoka, 816-8580 (Japan); Mazelle, Christian X., E-mail: nakanot@esst.kyushu-u.ac.jp [IRAP, Université Paul Sabatier Toulouse III-CNRS, F-31028 Toulouse Cedex 4 (France)

    2017-09-10

    A shock–shock interaction is investigated by using a one-dimensional full particle-in-cell simulation. The simulation reproduces the collision of two symmetrical high Mach number quasi-perpendicular shocks. The basic structure of the shocks and ion dynamics is similar to that obtained by previous hybrid simulations. The new aspects obtained here are as follows. Electrons are already strongly accelerated before the two shocks collide through multiple reflection. The reflected electrons self-generate waves upstream between the two shocks before they collide. The waves far upstream are generated through the right-hand resonant instability with the anomalous Doppler effect. The waves generated near the shock are due to firehose instability and have much larger amplitudes than those due to the resonant instability. The high-energy electrons are efficiently scattered by the waves so that some of them gain large pitch angles. Those electrons can be easily reflected at the shock of the other side. The accelerated electrons form a power-law energy spectrum. Due to the accelerated electrons, the pressure of upstream electrons increases with time. This appears to cause the deceleration of the approaching shock speed. The accelerated electrons having sufficiently large Larmor radii are further accelerated through the similar mechanism working for ions when the two shocks are colliding.

  15. An explicit MOT-TDVIE scheme for analyzing electromagnetic field interactions on nonlinear scatterers

    KAUST Repository

    Ulku, Huseyin Arda

    2015-02-01

    An explicit marching on-in-time (MOT) based time domain electric field volume integral equation (TDVIE) solver for characterizing electromagnetic wave interactions on scatterers with nonlinear material properties is proposed. Discretization of the unknown electric field intensity and flux density is carried out by half and full Schaubert-Wilton-Glisson basis functions, respectively. Coupled system of spatially discretized TDVIE and the nonlinear constitutive relation between the field intensity and the flux density is integrated in time to compute the samples of the unknowns. An explicit PE(CE)m scheme is used for this purpose. Explicitness allows for \\'easy\\' incorporation of the nonlinearity as a function only to be evaluated on the right hand side of the coupled system of equations. A numerical example that demonstrates the applicability of the proposed MOT scheme to analyzing electromagnetic interactions on Kerr-nonlinear scatterers is presented. © 2015 IEEE.

  16. Investigations of the structure and electromagnetic interactions of few-body systems

    International Nuclear Information System (INIS)

    Lehman, D.R.; Haberzettl, H.; Maximon, L.C.; Parke, W.C.; Bennhold, C.; Ito, Hiroshi; Pratt, R.K.; Najmeddine, M.; Rakei, A.

    1993-07-01

    The emphasis of the nuclear theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered, including coherent photoproduction of π mesons. When the excitation energy of the target nucleus is low, the aim is to handle the continuum part of the theoretical work numerically with no approximations, that is, by means of full three- or four-body dynamics. When structure questions are the issue, numerically accurate calculations are always carried through, limited only by the underlying two-body or three-body interactions used as input. A central goal is to carry through state-of-the-art few-body calculations that will serve as a means of determining at what point standard nuclear physics requires introduction of relativity and/or quark degrees of freedom in order to understand the phenomena in question

  17. Nonlinear interactions of electromagnetic waves with the auroral ionosphere

    Science.gov (United States)

    Wong, Alfred Y.

    1999-09-01

    The ionosphere provides us with an opportunity to perform plasma experiments in an environment with long confinement times, very large-scale lengths, and no confining walls. The auroral ionosphere with its nearly vertical magnetic field geometry is uniquely endowed with large amount of free energy from electron and ion precipitation along the magnetic field and mega-ampere current across the magnetic field. To take advantage of this giant outdoor laboratory, two facilities HAARP and HIPAS, with frequencies ranging from the radio to optical bands, are now available for active probing of and interaction with this interesting region. The ponderomotive pressures from the self-consistent wave fields have produced significant local perturbations of density and particle distributions at heights where the incident EM frequency matches a plasma resonance. This paper will review theory and experiments covering the nonlinear phenomena of parametric decay instability to wave collapse processes. At HF frequencies plasma lenses can be created by preconditioning pulses to focus what is a normally divergent beam into a high-intensity spot to further enhance nonlinear phenomena. At optical wavelengths a large rotating liquid metal mirror is used to focus laser pulses up to a given height. Such laser pulses are tuned to the same wavelengths of selected atomic and molecular resonances, with resulting large scattering cross sections. Ongoing experiments on dual-site experiments and excitation of ELF waves will be presented. The connection of such basic studies to environmental applications will be discussed. Such applications include the global communication using ELF waves, the ozone depletion and remediation and the control of atmospheric CO2 through the use of ion cyclotron resonant heating.

  18. Decay properties of heavy leptons in the supersymmetric model of weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Egorian, Ed.

    1979-01-01

    Decay properties of heavy leptons in the SU(2)xSU(2)xU(1) supersymmetric model of weak and electromagnetic interactions are studied. l anti νsub(e)ν leptonic and ν(νsup(c))h semihadronic decays, where l are leptons and h are hadrons, are considered. The partial and total decay rates and the production in p anti p collision of one of them are estimated for various values of its mass

  19. On the theory of interaction of electromagnetic waves with Bose-Einstein magnon condensate

    International Nuclear Information System (INIS)

    Loktev, V.M.

    2008-01-01

    An attempt is made to analyze the dependence of the Raman scattering cross section or the absorption/emission of electromagnetic waves by a Bose-Einstein condensate of magnons on their (magnons) density. Specifically, the intensities of one- and two-magnon transitions are compared and it is concluded that latter dominate in a Bose condensate. The salient features and possible role of the inter-magnon interaction are discussed briefly

  20. Implications of experiment on gauge theories of the weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Barnett, R.M.

    1977-06-01

    In this review the phenomenology of four new models for gauge theories of the weak and electromagnetic interactions is discussed that are extensions of SU(2) x U(1) models. Included are the neutral-current phenomenology (neutrino-proton deep-inelastic, neutrino-proton elastic, neutrino-electron elastic, and atomic parity violation). The charged-current neutrino scattering includes the y-dependence, the ratio of anti ν to ν cross sections, and di- and trilepton production. 80 references

  1. Final Report - Few-Body Studies Using Electromagnetic Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Norum, Blaine [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Physics

    2018-01-25

    The work discussed here is an extension of work previously funded by U.S. Department of Energy Grant DE-FG02-97ER41025. Measurements of charged pion photoproduction from deuterium using the Laser Electron Gamma Source (LEGS) at the Brookhaven National Laboratory previously made by us, as members of the LEGS Collaboration, resulted in the most interesting result of two decades of work. By measuring the production of a charged pion (π+) in coincidence with an emitted photon we observed structures in the residual two-nucleon system. These indicated the existence of rare, long-lived states not explicable by standard nuclear theory; they suggested a set of configurations not explicable in terms of a nucleon-nucleon pair. The existence of such “exotic” structures has formed the foundation for most of the work that has ensued. Several measurements at various laboratories have supported, but not proved, the existence of these exotic states. The rarity of these states made their existence undetectable in most previous measurements. Only by observing characteristic signatures of such states (i.e., decay photons), by using very specific kinematics which isolate certain reaction products, or by measuring polarization-dependent observables. During the period of this grant we pursued and made progress on the development of experiments to be performed at the High Intensity Gamma Source (HIGS) of the Tri Universities Nuclear Laboratory (TUNL). Our understanding of photon- and electron-induced nuclear reactions depends on understanding of the basic electron and photon interaction. Recently, the issue of two-photon contributions has arisen in the context of deeply inelastic electron scattering. One way to address this is to measure asymmetries in the Bethe-Heitler ee process. We also made progress in developing the detectors required to measure these asymmetries at HIGS. During the last several years the apparent discrepancy between the size of the proton as measured

  2. Neutral currents and electromagnetic renormalization of the vector part of neutrino weak interaction

    International Nuclear Information System (INIS)

    Folomeshkin, V.N.

    1976-01-01

    The nature and properties of neutral currents in neutrino processes at high energies are theoretically investigated. Electronagmetic renormalization of diagonal ((νsub(e)e(νsub(e)e) and (νsub(μ)μ)(νsub(μ)μ)) and nondiagonal ((νsub(e)μ)(νsub(e)μ)) interactions is discussed in terms of the universal fourfermion interaction model. It is shown that electromagnetic renormalization of neutrino vector interaction caused an effective appearance of vector neutral currents with photon isotopic structure. The value for the interaction constant is unambigously defined by the ratio of the total cross-section for electron-positron annihilation into muonic pairs. Interaction (renormalization) constants for neutral currents are pointed out to be always smaller than interaction constants for charge currents

  3. Improvement of localised corrosion resistance of AISI 2205 Duplex Stainless Steel joints made by gas metal arc welding under electromagnetic interaction of low intensity

    Energy Technology Data Exchange (ETDEWEB)

    García-Rentería, M.A., E-mail: crazyfim@gmail.com [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); López-Morelos, V.H., E-mail: vhlopez@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); García-Hernández, R., E-mail: rgarcia@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); Dzib-Pérez, L., E-mail: luirdzib@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); García-Ochoa, E.M., E-mail: emgarcia@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); González-Sánchez, J., E-mail: jagonzal@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico)

    2014-12-01

    Highlights: • Electromagnetic interaction in welding improved localised corrosion resistance. • Electromagnetic interaction in welding enhanced γ/δ phase balance of DuplexSS. • Welding under Electromagnetic interaction repress formation and growth of detrimental phases. • Welds made with gas protection (2% O{sub 2} + 98% Ar) have better microstructural evolution during welding. - Abstract: The resistance to localised corrosion of AISI 2205 duplex stainless steel plates joined by Gas Metal Arc Welding (GMAW) under the effect of electromagnetic interaction of low intensity (EMILI) was evaluated with sensitive electrochemical methods. Welds were made using two shielding gas mixtures: 98% Ar + 2% O{sub 2} (M1) and 97% Ar + 3% N{sub 2} (M2). Plates were welded under EMILI using the M1 gas with constant welding parameters. The modified microstructural evolution in the high temperature heat affected zone and at the fusion zone induced by application of EMILI during welding is associated with the increase of resistance to localised corrosion of the welded joints. Joints made by GMAW using the shielding gas M2 without the application of magnetic field presented high resistance to general corrosion but high susceptibility to undergo localised attack.

  4. University Physics Students' Use of Models in Explanations of Phenomena Involving Interaction between Metals and Electromagnetic Radiation.

    Science.gov (United States)

    Redfors, Andreas; Ryder, Jim

    2001-01-01

    Examines third year university physics students' use of models when explaining familiar phenomena involving interaction between metals and electromagnetic radiation. Concludes that few students use a single model consistently. (Contains 27 references.) (DDR)

  5. The effect of electromagnetic interactions on the proton spectrum in free neutron β-decay

    International Nuclear Information System (INIS)

    Bunatyan, G.G.

    2000-01-01

    In the β decay of an unpolarized free neutron, the effect of electromagnetic interactions on the proton recoil spectrum is studied in the light of the experiments which are carried out and planned for now. The corrections to the energy distribution of protons prove to amount to the value of a few per cent. Nowadays, this is substantial for obtaining with a high accuracy, of ∼ 1% or better, the characteristics of weak interactions by processing the data of the experiments on the proton distribution in the free neutron β-decay

  6. Neutral currents and the gauge group of weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Rajpoot, S.

    1977-12-01

    In considering the question of neutral current parity conversation, models of weak and electromagnetic interactions based on the gauge sub group SU(2)sub(L)xSU(2)sub(R)x(U) 1 are examined. The thesis is presented in the following sections: (1) Introduction. (2) Natural left-right symmetric theory and its neutral current phenomenology. (3) Effects of neutral weak currents in electron-positron annihilation. (4) Dilepton production in pp and anti pp collisions as a probe to the nature of the neutral current interaction. (U.K.)

  7. Emission and electron transitions in an atom interacting with an ultrashort electromagnetic pulse

    International Nuclear Information System (INIS)

    Matveev, V.I.

    2003-01-01

    Electron transitions and emission of an atom interacting with a spatially inhomogeneous ultrashort electromagnetic pulse are considered. The excitation and ionization probabilities are obtained as well as the spectra and cross sections of the reemission of such a pulse by atoms. By way of an example, one- and two-electron inelastic processes accompanying the interaction of ultrashort pulses with hydrogen- and helium-like atoms are considered. The developed technique makes it possible to take into account exactly the spatial nonuniformity of the ultrashort pulse field and photon momenta in the course of reemission

  8. Multipolar electromagnetic fields around neutron stars: general-relativistic vacuum solutions

    Science.gov (United States)

    Pétri, J.

    2017-12-01

    Magnetic fields inside and around neutron stars are at the heart of pulsar magnetospheric activity. Strong magnetic fields are responsible for quantum effects, an essential ingredient to produce leptonic pairs and the subsequent broad-band radiation. The variety of electromagnetic field topologies could lead to the observed diversity of neutron star classes. Thus, it is important to include multipolar components to a presumably dominant dipolar magnetic field. Exact analytical solutions for these multipoles in Newtonian gravity have been computed in recent literature. However, flat space-time is not adequate to describe physics in the immediate surroundings of neutron stars. We generalize the multipole expressions to the strong gravity regime by using a slowly rotating metric approximation such as the one expected around neutron stars. Approximate formulae for the electromagnetic field including frame dragging are computed from which we estimate the Poynting flux and the braking index. Corrections to leading order in compactness and spin parameter are presented. As far as spin-down luminosity is concerned, it is shown that frame dragging remains irrelevant. For high-order multipoles starting from the quadrupole, the electric part can radiate more efficiently than the magnetic part. Both analytical and numerical tools are employed.

  9. Generalized algorithm for control of numerical dispersion in explicit time-domain electromagnetic simulations

    Directory of Open Access Journals (Sweden)

    Benjamin M. Cowan

    2013-04-01

    Full Text Available We describe a modification to the finite-difference time-domain algorithm for electromagnetics on a Cartesian grid which eliminates numerical dispersion error in vacuum for waves propagating along a grid axis. We provide details of the algorithm, which generalizes previous work by allowing 3D operation with a wide choice of aspect ratio, and give conditions to eliminate dispersive errors along one or more of the coordinate axes. We discuss the algorithm in the context of laser-plasma acceleration simulation, showing significant reduction—up to a factor of 280, at a plasma density of 10^{23}  m^{-3}—of the dispersion error of a linear laser pulse in a plasma channel. We then compare the new algorithm with the standard electromagnetic update for laser-plasma accelerator stage simulations, demonstrating that by controlling numerical dispersion, the new algorithm allows more accurate simulation than is otherwise obtained. We also show that the algorithm can be used to overcome the critical but difficult challenge of consistent initialization of a relativistic particle beam and its fields in an accelerator simulation.

  10. Electromagnetic Waves Dispersion and Interaction of an Annular Beam-Ion Channel System in Plasma Waveguide

    Directory of Open Access Journals (Sweden)

    Jixiong Xiao

    2017-01-01

    Full Text Available A linear theory for the electromagnetic properties and interactions of an annular beam-ion channel system in plasma waveguide is presented. The dispersion relations for two families of propagating modes, including the electrostatic and transverse magnetic modes, are derived. The dependencies of the dispersion behavior and interaction for different wave modes on the thickness of the annular beam and betatron oscillation frequency are studied in detail by numerical calculations. The results show that the inner and outer radii of the beam have different influences on propagation properties of the electrostatic and electromagnetic modes with different betatron oscillation parameters. In the weak ion channel situation, the two types of electrostatic waves, that is, space charge and betatron modes, have no interaction with the transverse magnetic modes. However, in the strong ion channel situation, the transverse magnetic modes will have two branches and a low frequency mode emerged as the new branch. In this case, compared with the solid beam case, the betatron modes not only can interact with the high frequency branch at small wavenumber but also can interact with the low frequency branch at large wavenumber.

  11. Simultaneous multiphoton processes in the interaction of atoms with electromagnetic fields

    International Nuclear Information System (INIS)

    Levine, A.M.; Schreiber, W.M.; Weiszmann, A.N.

    1984-01-01

    It is impossible to obtain an exact description of multiphoton processes in the interaction of electromagnetic fields with atomic systems. Approximate approaches must be used to describe the physically different effects that can occur. One effect is the stepwise absorption/emission of many photons by a N-level system that evolves dynamically in between each absorption/emission. Another effect is described in the theories of Raman processes where the simultaneous absorption/emission of many photons is considered. In this paper, consideration is given to both processes allowing interference between the stepwise and simultaneous absorptions. An approximate Hamiltonian is obtained from the quantum mechanical multipole expansion. An exact solution of an atom-field system subject to this Hamiltonian will be presented. The extension of the method to multiple electromagnetic fields is discussed

  12. Analysis of transient electromagnetic wave interactions on graphene-based devices using integral equations

    KAUST Repository

    Shi, Yifei

    2015-10-26

    Graphene is a monolayer of carbon atoms structured in the form of a honeycomb lattice. Recent experimental studies have revealed that it can support surface plasmons at Terahertz frequencies thanks to its dispersive conductivity. Additionally, characteristics of these plasmons can be dynamically adjusted via electrostatic gating of the graphene sheet (K. S. Novoselov, et al., Science, 306, 666–669, 2004). These properties suggest that graphene can be a building block for novel electromagnetic and photonic devices for applications in the fields of photovoltaics, bio-chemical sensing, all-optical computing, and flexible electronics. Simulation of electromagnetic interactions on graphene-based devices is not an easy task. The thickness of the graphene sheet is orders of magnitude smaller than any other geometrical dimension of the device. Consequently, discretization of such a device leads to significantly large number of unknowns and/or ill-conditioned matrix systems.

  13. The general theory of the mechanical, electromagnetic and thermodynamic properties of black holes

    International Nuclear Information System (INIS)

    Carter, B.

    1979-01-01

    The introductory section includes a brief account of the basic mathematical concept of a black hole in a general dynamical context. This is followed by a more detailed examination of the properties of the horizon with particular reference to situations in which the black hole is allowed to tend asymptotically towards a stationary final equilibrium state. A more specialized description is then provided of the properties of the horizon in an exactly stationary state. Quasi-stationary states are next considered. The mass of a black hole is discussed. The final section summarizes the results that provide the justification for the belief that a stationary, asymptotically flat black hole state is fully determined by its mass and angular momentum when external matter and fields are absent, or by its mass, angular momentum, and electric charge if electromagnetic fields are allowed for. (U.K.)

  14. Electromagnetic perturbations of black holes in general relativity coupled to nonlinear electrodynamics

    Science.gov (United States)

    Toshmatov, Bobir; Stuchlík, Zdeněk; Schee, Jan; Ahmedov, Bobomurat

    2018-04-01

    The electromagnetic (EM) perturbations of the black hole solutions in general relativity coupled to nonlinear electrodynamics (NED) are studied for both electrically and magnetically charged black holes, assuming that the EM perturbations do not alter the spacetime geometry. It is shown that the effective potentials of the electrically and magnetically charged black holes related to test perturbative NED EM fields are related to the effective metric governing the photon motion, contrary to the effective potential of the linear electrodynamic (Maxwell) field that is related to the spacetime metric. Consequently, corresponding quasinormal (QN) frequencies differ as well. As a special case, we study new family of the NED black hole solutions which tend in the weak field limit to the Maxwell field, giving the Reissner-Nordström (RN) black hole solution. We compare the NED Maxwellian black hole QN spectra with the RN black hole QN spectra.

  15. Modeling ultrashort electromagnetic pulses with a generalized Kadomtsev-Petviashvili equation

    Science.gov (United States)

    Hofstrand, A.; Moloney, J. V.

    2018-03-01

    In this paper we derive a properly scaled model for the nonlinear propagation of intense, ultrashort, mid-infrared electromagnetic pulses (10-100 femtoseconds) through an arbitrary dispersive medium. The derivation results in a generalized Kadomtsev-Petviashvili (gKP) equation. In contrast to envelope-based models such as the Nonlinear Schrödinger (NLS) equation, the gKP equation describes the dynamics of the field's actual carrier wave. It is important to resolve these dynamics when modeling ultrashort pulses. We proceed by giving an original proof of sufficient conditions on the initial pulse for a singularity to form in the field after a finite propagation distance. The model is then numerically simulated in 2D using a spectral-solver with initial data and physical parameters highlighting our theoretical results.

  16. Nonlinear gyrokinetic equations for low-frequency electromagnetic waves in general plasma equilibria

    International Nuclear Information System (INIS)

    Frieman, E.A.; Chen, L.

    1981-10-01

    A nonlinear gyrokinetic formalism for low-frequency (less than the cyclotron frequency) microscopic electromagnetic perturbations in general magnetic field configurations is developed. The nonlinear equations thus derived are valid in the strong-turbulence regime and contain effects due to finite Larmor radius, plasma inhomogeneities, and magentic field geometries. The specific case of axisymmetric tokamaks is then considered, and a model nonlinear equation is derived for electrostatic drift waves. Also, applying the formalism to the shear Alfven wave heating sceme, it is found that nonlinear ion Landau damping of kinetic shear-Alfven waves is modified, both qualitatively and quantitatively, by the diamagnetic drift effects. In particular, wave energy is found to cascade in wavenumber instead of frequency

  17. Resonant Interaction, Approximate Symmetry, and Electromagnetic Interaction (EMI) in Low Energy Nuclear Reactions (LENR)

    Science.gov (United States)

    Chubb, Scott

    2007-03-01

    Only recently (talk by P.A. Mosier-Boss et al, in this session) has it become possible to trigger high energy particle emission and Excess Heat, on demand, in LENR involving PdD. Also, most nuclear physicists are bothered by the fact that the dominant reaction appears to be related to the least common deuteron(d) fusion reaction,d+d ->α+γ. A clear consensus about the underlying effect has also been illusive. One reason for this involves confusion about the approximate (SU2) symmetry: The fact that all d-d fusion reactions conserve isospin has been widely assumed to mean the dynamics is driven by the strong force interaction (SFI), NOT EMI. Thus, most nuclear physicists assume: 1. EMI is static; 2. Dominant reactions have smallest changes in incident kinetic energy (T); and (because of 2), d+d ->α+γ is suppressed. But this assumes a stronger form of SU2 symmetry than is present; d+d ->α+γ reactions are suppressed not because of large changes in T but because the interaction potential involves EMI, is dynamic (not static), the SFI is static, and because the two incident deuterons must have approximate Bose Exchange symmetry and vanishing spin. A generalization of this idea involves a resonant form of reaction, similar to the de-excitation of an atom. These and related (broken gauge) symmetry EMI effects on LENR are discussed.

  18. Left--right symmetric gauge theories of weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Sidhu, D.P.

    1978-01-01

    We review the recent progress in spontaneously broken left-right symmetric gauge theories of weak and electromagnetic interactions. Recently gauge theories based on the group SU(2)/Sub L/ x SU(2)/sub R/ x U(1) have been proposed as serious candidates for a unified description of the weak and electromagnetic interactions. Such theories have a number of attractive features which are not shared by the standard SU(2) x U(1) theories. Parity violation as well as CP-violation are spontaneous in origin and, therefore, theories are parity conserving before spontaneous breakdown of the symmetry and also afterwards at asymptotic energies. The asymmetry in low energy charged current weak interaction, i.e., predominance of left-handed charged current interactions over the right-handed ones, is a consequence of the symmetry breaking thus leading to a conceptually different picture of weak interaction at low energies. Another appealing feature of these theories is the beauty and richness of the structure of weak neutral current interactions. One can have a parity conserving structure of the neutral currents (one neutral boson (Z/sub V/) has pure vector and the other (Z/sub A/) pure axial vector coupling to quarks and leptons) which is natural in the technical sense of the word. Models of this type provide the most elegant explanation of the failure to find parity violation in atoms at the level predicted on the basis of the Weinberg-Salam model. In spite of manifestly parity conserving neutral current interactions, ν/sub μ/N and anti ν/sub μ/N (also ν/sub μ/e and anti ν/sub μ/e) neutral current cross-sections have to be unequal in these theories because of the definite parity and charge conjugation of the Z-bosons

  19. Interaction of an atom subject to an intense laser field with its own radiation field and nonlocality of electromagnetic interaction

    International Nuclear Information System (INIS)

    Gainutdinov, R Kh; Mutygullina, A A

    2009-01-01

    We discuss the interaction of an atom subject to an intense driving laser field with its own radiation field. In contrast to the states of bare atoms, the energy difference between some dressed states with the same total angular momentum, its projection and parity may be very small. The self-interaction of a combined atom-laser system associated with nonradiative transitions between such states is effectively strong. We show that the contribution to the radiative shift of the sidebands of the Mollow spectrum, which comes from such processes, is very significant and may be much larger than the trivial Lamb shift, which is the simple redistribution of the Lamb shifts of the corresponding bare states. In the final part, we discuss the possibility that in the Mollow spectrum nonlocality of electromagnetic interaction, which in other cases is hidden in the regularization and renormalization procedures, can manifest itself explicitly.

  20. Human health and exposure to electromagnetic radiation

    International Nuclear Information System (INIS)

    Dennis, J.A.; Muirhead, C.R.; Ennis, J.R.

    1992-07-01

    This review consists of three main parts. In the first the general features of electromagnetic fields and their interactions with the human body are described. The second part deals with the epidemiological evidence for effects on general health and birth outcome. The third part describes the epidemiological evidence from occupational and residential studies of a possible association between electromagnetic field exposures and cancer. (author)

  1. Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

    Energy Technology Data Exchange (ETDEWEB)

    Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

    1983-02-01

    This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants.

  2. The interaction of two collinear cracks in a rectangular superconductor slab under an electromagnetic force

    International Nuclear Information System (INIS)

    Gao Zhiwen; Zhou Youhe; Lee, Kang Yong

    2010-01-01

    The interaction of two collinear cracks is obtained for a type-II superconducting under electromagnetic force. Fracture analysis is performed by means of finite element method and the magnetic behavior of superconductor is described by the critical-state Bean model. The stress intensity factors at the crack tips can be obtained and discussed for decreasing field after zero-field cooling. It is revealed that the stress intensity factor decreases as applied field increases. The crack-tip stress intensity factors decrease when the distance between the two collinear cracks increases and the superconductors with smaller crack has more remarkable shielding effect than those with larger cracks.

  3. Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

    International Nuclear Information System (INIS)

    Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

    1983-02-01

    This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants

  4. Interaction of electromagnetic radiation with magnetically functionalized CNT nanocomposite in the subterahertz frequency range

    Energy Technology Data Exchange (ETDEWEB)

    Atdaev, A.; Danilyuk, A. L.; Labunov, V. A.; Prischepa, S. L., E-mail: prischepa@bsuir.by [Belarusian State University of Informatics and Radioelectronics (Belarus); Pavlov, A. A. [Russian Academy of Sciences, Institute of Microelectronics Nanotechnologies (Russian Federation); Basaev, A. S.; Shaman, Yu. P. [SMC Technological Center (Russian Federation)

    2016-12-15

    The interaction of electromagnetic radiation with a magnetically functionalized nanocomposite based on carbon nanotubes (CNTs) is considered using the model of random distribution of ferromagnetic nanoparticles in the carbon matrix characterized by the presence of resistive–inductive–capacitive coupling (contours). The model is based on the representation of the nanocomposite as a system consisting of the CNT matrix, ferromagnetic nanoparticles, and the interfaces between CNTs and nanoparticles. The wide range of possible resonant phenomena caused both by the presence of contours and the properties of the CNT nanocomposite is shown.

  5. Nonlinear optical properties of an electromagnetically induced transparency medium interacting with two quantized fields

    CERN Document Server

    Kuang-Leman; Wu Yong Shi

    2003-01-01

    We study linear and nonlinear optical properties of an electromagnetically induced transparency (EIT) medium interacting with two quantized laser fields in the adiabatic EIT case. We show that the EIT medium exhibits normal dispersion. Kerr and higher-order nonlinear refractive index coefficients are also calculated in a completely analytical form. It is indicated that the EIT medium exhibits giant resonantly enhanced nonlinearities. We discuss the response of the EIT medium to nonclassical light fields and find that the polarization vanishes when the probe laser is initially in a nonclassical state of no single-photon coherence.

  6. Electromagnetic spin–orbit interaction and giant spin-Hall effect in dielectric particle clusters

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yineng [Department of Physics, Beijing Normal University, Beijing 100875 (China); Zhang, Xiangdong, E-mail: zhangxd@bit.edu.cn [School of Physics and Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, 100081, Beijing (China)

    2013-12-09

    We report a phenomenon that electromagnetic spin–orbit interactions can be tailored by dielectric nanoparticles, and self-similar giant spin-Hall effect has been observed in the dielectric particle cluster. The near-field phase singularities and phase vorticity in the longitudinal component of scattered field can also be controlled by such a dielectric structure. The origin of phenomena is believed to be due to the collective resonance excitation in the dielectric particle cluster. It is expected to find applications in optics information processing and designing new nanophotonic devices.

  7. Interactive design for self-study and developing students’ critical thinking skills in electromagnetic radiation topic

    Science.gov (United States)

    Ambarwati, D.; Suyatna, A.

    2018-01-01

    The purpose of this research are to create interactive electronic school books (ESB) for electromagnetic radiation topic that can be used for self-study and increasing students’ critical thinking skills. The research method was based on the design of research and development (R&D) model of ADDIE. The research procedure is used limited the design of the product has been validated. Data source at interactive requirement analysis phase of ESB is student and high school teacher of class XII in Lampung province. The validation of interactive ESB designs is performed by experts in science education. The data of ESB interactive needs were collected using questionnaires and analyzed using quantitative descriptive. The results of the questionnaire obtained by 97% of books that are often used in the form of printed books from schools have not been interactive and foster critical thinking of students, and 55% of students stating physics books are used not meet expectations. Expectations of students in physics learning, teachers must use interactive electronic books. The results of the validation experts pointed out, the design of ESB produced is interactive, can be used for self-study, and increasing students’ critical thinking skills, which contains instruction manuals, learning objectives, learning materials, sample questions and discussion, video illustrations, animations, summaries, as well as interactive quizzes incorporating feedback exam practice and preparation for college entrance.

  8. German wide cross sectional survey on health impacts of electromagnetic fields in the view of general practitioners

    DEFF Research Database (Denmark)

    Kowall, Bernd; Breckenkamp, Jürgen; Heyer, Kristina

    2010-01-01

    OBJECTIVES: The proportion of general practitioners (GPs) in Germany who assume health impacts of electromagnetic fields (EMF) is assessed. Moreover, factors associated with this risk perception are examined. METHODS: A 7% random sample was drawn from online lists of all the GPs working in Germany...

  9. Particle physics in intense electromagnetic fields

    International Nuclear Information System (INIS)

    Kurilin, A.V.

    1999-01-01

    The quantum field theory in the presence of classical background electromagnetic field is reviewed giving a pedagogical introduction to the Feynman-Furry method of describing non-perturbative interactions with very strong electromagnetic fields. A particular emphasis is given to the case of the plane-wave electromagnetic field for which the charged particles' wave functions and propagators are presented. Some general features of quantum processes proceeding in the intense electromagnetic background are argued. The possibilities of searching new physics through the investigations of quantum phenomena induced by a strong electromagnetic environment are also discussed

  10. Analysis of plasma behavior and electro-magnetic interaction between plasma and device

    International Nuclear Information System (INIS)

    Kobayashi, Tomofumi

    1980-01-01

    A simulation program for the analysis of plasma behavior and the electromagnetic interaction between plasma and device has been developed. The program consists of a part for the analysis of plasma behavior (plasma system) and a part for the analysis of the electro-magnetic interaction between plasma and devices (circuit system). The parameters which connect the plasma system and the circuit system are the electric resistance of plasma, the internal inductance, and the plasma current. For the plasma system, the simultaneous equations which describe the density distribution of plasma particles, the temperature distribution of electrons and ions, and the space-time variation of current density distribution were derived. The one-dimensional plasma column in γ-direction was considered. The electric resistance and the internal inductance can be deduced. The circuit components are a current transformer, a vertical field coil, a quadrupole field coil, a vacuum chamber and others. An equation which describes plasma position and the shape of cross section is introduced. The plasma position can be known by solving the Mukhavatov's formula of equilibrium. By using this program, the build-up process of plasma current in JT-60 was analysed. It was found that the expansion of plasma sub radius and the control of current distribution by gas injection are the effective methods to obtain high temperature and high density plasma. The eddy current induced in a vacuum vessel shields 40 percent of magnetic field made in the plasma region by a vertical field coil. (Kato, T.)

  11. Fundamental relativistic rotator: Hessian singularity and the issue of the minimal interaction with electromagnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Bratek, Lukasz, E-mail: lukasz.bratek@ifj.edu.pl [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskego 152, PL-31342 Krakow (Poland)

    2011-05-13

    There are two relativistic rotators with Casimir invariants of the Poincare group being fixed parameters. The particular models of spinning particles were studied in the past both at the classical and quantum level. Recently, a minimal interaction with electromagnetic field has been considered. We show that the dynamical systems can be uniquely singled out from among other relativistic rotators by the unphysical requirement that the Hessian referring to the physical degrees of freedom should be singular. Closely related is the fact that the equations of free motion are not independent, making the evolution indeterminate. We show that the Hessian singularity cannot be removed by the minimal interaction with the electromagnetic field. By making use of a nontrivial Hessian null space, we show that a single constraint appears in the external field for consistency of the equations of motion with the Hessian singularity. The constraint imposes unphysical limitation on the initial conditions and admissible motions. We discuss the mechanism of appearance of unique solutions in external fields on an example of motion in the uniform magnetic field. We give a simple model to illustrate that similarly constrained evolution cannot be determinate in arbitrary fields.

  12. Instability of collective strong-interaction phenomena in hadron production as a possible origin of the weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Arnold, R.C.

    1975-12-01

    A systematic calculus of long-range Regge cut effects in multiparticle production is constructed in the form of an infrared-divergent stochastic field theory. Total cross sections and two-body overlap integrals in such a theory may depend very sensitively upon internal quantum-numbers of incident particles, resulting in a strong symmetry breaking at ultra-high energies. Such symmetry violations will influence low energy processes through dispersion relations, and a bootstrap of weak interactions becomes possible. A rough analytic estimate of the scale of thresholds for such effects yields a BCS-type gap equation, which expresses the scale of weak and electromagnetic couplings in terms of purely strong-interaction parameters

  13. Electromagnetic force on a brane

    International Nuclear Information System (INIS)

    Li, Li-Xin

    2016-01-01

    A fundamental assumption in the theory of brane world is that all matter and radiation are confined on the four-dimensional brane and only gravitons can propagate in the five-dimensional bulk spacetime. The brane world theory did not provide an explanation for the existence of electromagnetic fields and the origin of the electromagnetic field equation. In this paper, we propose a model for explaining the existence of electromagnetic fields on a brane and deriving the electromagnetic field equation. Similar to the case in Kaluza–Klein theory, we find that electromagnetic fields and the electromagnetic field equation can be derived from the five-dimensional Einstein field equation. However, the derived electromagnetic field equation differs from the Maxwell equation by containing a term with the electromagnetic potential vector coupled to the spacetime curvature tensor. So it can be considered as generalization of the Maxwell equation in a curved spacetime. The gravitational field equation on the brane is also derived with the stress–energy tensor for electromagnetic fields explicitly included and the Weyl tensor term explicitly expressed with matter fields and their derivatives in the direction of the extra-dimension. The model proposed in the paper can be regarded as unification of electromagnetic and gravitational interactions in the framework of brane world theory. (paper)

  14. Electromagnetic cascade in high-energy electron, positron, and photon interactions with intense laser pulses

    Science.gov (United States)

    Bulanov, S. S.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2013-06-01

    The interaction of high-energy electrons, positrons, and photons with intense laser pulses is studied in head-on collision geometry. It is shown that electrons and/or positrons undergo a cascade-type process involving multiple emissions of photons. These photons can consequently convert into electron-positron pairs. As a result charged particles quickly lose their energy developing an exponentially decaying energy distribution, which suppresses the emission of high-energy photons, thus reducing the number of electron-positron pairs being generated. Therefore, this type of interaction suppresses the development of the electromagnetic avalanche-type discharge, i.e., the exponential growth of the number of electrons, positrons, and photons does not occur in the course of interaction. The suppression will occur when three-dimensional effects can be neglected in the transverse particle orbits, i.e., for sufficiently broad laser pulses with intensities that are not too extreme. The final distributions of electrons, positrons, and photons are calculated for the case of a high-energy e-beam interacting with a counterstreaming, short intense laser pulse. The energy loss of the e-beam, which requires a self-consistent quantum description, plays an important role in this process, as well as provides a clear experimental observable for the transition from the classical to quantum regime of interaction.

  15. Transient interaction model of electromagnetic field generated by lightning current pulses and human body

    International Nuclear Information System (INIS)

    Iváncsy, T; Kiss, I; Tamus, Z Á; Szücs, L

    2015-01-01

    The lightning current generates time-varying magnetic field near the down-conductor and the down-conductors are mounted on the wall of the buildings where residential places might be situated. It is well known that the rapidly changing magnetic fields can generate dangerous eddy currents in the human body.The higher duration and gradient of the magnetic field can cause potentially life threatening cardiac stimulation. The coupling mechanism between the electromagnetic field and the human body is based on a well-known physical phenomena (e.g. Faradays law of induction). However, the calculation of the induced current is very complicated because the shape of the organs is complex and the determination of the material properties of living tissues is difficult, as well. Our previous study revealed that the cardiac stimulation is independent of the rising time of the lightning current and only the peak of the current counts.In this study, the authors introduce an improved model of the interaction of electromagnetic fields of lighting current near down-conductor and human body. Our previous models are based on the quasi stationer field calculations, the new improved model is a transient model. This is because the magnetic field around the down-conductor and in the human body can be determined more precisely, therefore the dangerous currents in the body can be estimated. (paper)

  16. Interaction with the lower ionosphere of electromagnetic pulses from lightning: Heating, attachment, and ionization

    International Nuclear Information System (INIS)

    Taranenko, Y.N.; Inan, U.S.; Bell, T.F.

    1993-01-01

    The authors model the interaction of lightning flashes with the lower ionosphere. They use a Boltzmann formulation of the electron distribution function, and use Maxwells equations for the electromagnetic fields. Electromagnetic pulses from lightning have pulse lengths of 50 to 150 μs and produce peak fields of 50 V/m at distances of 100 km from the discharges. Fields greater than 16 V/m can cause avalanche ionization of neutrals at elevations of 100 km, where typical mean free paths for electrons are at least a meter. Modeling the lightning flash as a 100 μs pulse of 10 kHz radiation emitted at 70km altitude, they find that in nighttime skies the pulse can affect the electron density in the range of 1 to 30%. A sequence of pulses can lead to substantial impact on the electron density. The propagation characteristics of the pulses are such as to result in a steepening of the boundary of the lower ionosphere

  17. New electromagnetic particle simulation code for the analysis of spacecraft-plasma interactions

    International Nuclear Information System (INIS)

    Miyake, Yohei; Usui, Hideyuki

    2009-01-01

    A novel particle simulation code, the electromagnetic spacecraft environment simulator (EMSES), has been developed for the self-consistent analysis of spacecraft-plasma interactions on the full electromagnetic (EM) basis. EMSES includes several boundary treatments carefully coded for both longitudinal and transverse electric fields to satisfy perfect conductive surface conditions. For the longitudinal component, the following are considered: (1) the surface charge accumulation caused by impinging or emitted particles and (2) the surface charge redistribution, such that the surface becomes an equipotential. For item (1), a special treatment has been adopted for the current density calculated around the spacecraft surface, so that the charge accumulation occurs exactly on the surface. As a result, (1) is realized automatically in the updates of the charge density and the electric field through the current density. Item (2) is achieved by applying the capacity matrix method. Meanwhile, the transverse electric field is simply set to zero for components defined inside and tangential to the spacecraft surfaces. This paper also presents the validation of EMSES by performing test simulations for spacecraft charging and peculiar EM wave modes in a plasma sheath.

  18. Airborne electromagnetics data interactive visualisation and exploratory data analysis using Cloud technologies

    Science.gov (United States)

    Golodoniuc, P.; Davis, A. C.; Klump, J. F.

    2017-12-01

    Electromagnetic exploration techniques are extensively used for remote detection and measurement of subsurface electrical conductivity structures for a variety of geophysical applications such as mineral exploration and groundwater detection. The Electromagnetic Applications group in the Mineral Resources business unit of CSIRO heavily relies upon the use of airborne electromagnetic (AEM) data for the development of new exploration methods. AEM data, which are often originally acquired for green- or brown-fields exploration for minerals, can be re-used for groundwater resource detection in the near-surface. This makes AEM data potentially useful beyond their initial purpose for decades into the future. Increasingly, AEM data are also used as a primary mapping tool for groundwater resources. With surveys ranging from under 1000 km to tens of thousands of km in total length, AEM data are spatially and temporally dense. Sounding stations are often sampled every 0.2 seconds, with about 30-50 measurements taken at each site, resulting in a spacing of measurements along the flight lines of approximately 20­-50 metres. This means that typical AEM surveys can easily have on the order of millions of individual stations, with tens of millions of measurements. AEM data needs to be examined for data quality before it can be inverted into conductivity-depth information. Data, which is gathered in survey transects or lines, is examined both along the line, in a plan view and for the transient decay of the electromagnetic signal of individual stations before noise artefacts can be removed. The complexity of the data, its size and dimensionality require efficient tools that support interactive visual data analysis and allows easy navigation through the dataset. A suite of numerical algorithms for data quality assurance facilitates this process through efficient visualisations and data quality metrics. The extensible architecture of the toolkit allows application of custom

  19. Lagrangian formulation for a gauge theory of strong and electromagnetic interactions defined on a Cartan bundle

    International Nuclear Information System (INIS)

    Drechsler, W.

    1977-01-01

    A Lagrangian formalism invariant under the gauge group U 1 xUSpsub(2.2) is set up in terms of spinor fields defined on a fiber bundle with Cartan connexion. The fiber of the Cartan bundle over space-time associated with strong interactions is characterized by an elementary length parameter R related to the range of the strong forces, and the structural group USpsub(2.2) of the bundle (being the covering group of the SOsub(4.1) de Sitter group) implies a gauge description of strong interactions based on the noncompact gauge group USpsub(2.2). The U 1 factor in the total gauge group corresponds to the usual gauge formulation for the electromagnetic interactions. The positivity of the energy associated with stable extended one-particle states in this dualistic description of charged hadronic matter immersed in the fiber geometry (this dualism is called strong fiber dynamics (SFD)) requires hadrons to be assigned to representations of the compact subgroup SU 2 xSU 2 of the strong-interaction gauge group USpsub(2.2). A brief discussion of the point-particle limit R→O is given by linking the presented SFD formalism for extended hadrons to an idealized description in terms of operators in a local quantum field theory

  20. A Novel Tactile Sensor with Electromagnetic Induction and Its Application on Stick-Slip Interaction Detection

    Directory of Open Access Journals (Sweden)

    Yanjie Liu

    2016-03-01

    Full Text Available Real-time detection of contact states, such as stick-slip interaction between a robot and an object on its end effector, is crucial for the robot to grasp and manipulate the object steadily. This paper presents a novel tactile sensor based on electromagnetic induction and its application on stick-slip interaction. An equivalent cantilever-beam model of the tactile sensor was built and capable of constructing the relationship between the sensor output and the friction applied on the sensor. With the tactile sensor, a new method to detect stick-slip interaction on the contact surface between the object and the sensor is proposed based on the characteristics of friction change. Furthermore, a prototype was developed for a typical application, stable wafer transferring on a wafer transfer robot, by considering the spatial magnetic field distribution and the sensor size according to the requirements of wafer transfer. The experimental results validate the sensing mechanism of the tactile sensor and verify its feasibility of detecting stick-slip on the contact surface between the wafer and the sensor. The sensing mechanism also provides a new approach to detect the contact state on the soft-rigid surface in other robot-environment interaction systems.

  1. A Novel Tactile Sensor with Electromagnetic Induction and Its Application on Stick-Slip Interaction Detection

    Science.gov (United States)

    Liu, Yanjie; Han, Haijun; Liu, Tao; Yi, Jingang; Li, Qingguo; Inoue, Yoshio

    2016-01-01

    Real-time detection of contact states, such as stick-slip interaction between a robot and an object on its end effector, is crucial for the robot to grasp and manipulate the object steadily. This paper presents a novel tactile sensor based on electromagnetic induction and its application on stick-slip interaction. An equivalent cantilever-beam model of the tactile sensor was built and capable of constructing the relationship between the sensor output and the friction applied on the sensor. With the tactile sensor, a new method to detect stick-slip interaction on the contact surface between the object and the sensor is proposed based on the characteristics of friction change. Furthermore, a prototype was developed for a typical application, stable wafer transferring on a wafer transfer robot, by considering the spatial magnetic field distribution and the sensor size according to the requirements of wafer transfer. The experimental results validate the sensing mechanism of the tactile sensor and verify its feasibility of detecting stick-slip on the contact surface between the wafer and the sensor. The sensing mechanism also provides a new approach to detect the contact state on the soft-rigid surface in other robot-environment interaction systems. PMID:27023545

  2. Effective potentials of the relativistic three-body problem with electromagnetic interaction in adiabatic approximation

    International Nuclear Information System (INIS)

    Bakalov, D.D.; Melezhik, V.S.

    1987-01-01

    The relativistic Hamiltonian for 3-spin particles with electromagnetic interaction has been represented in the form of a sum of terms with factorized dependence on spin, angular and spheroidal variable, and its matrix elements have been expressed in terms of the matrix elements of a small number of ''basic'' operators. The numerical values of the latter have been tabulated, thus allowing for the evaluation of the leading relativistic effects in any 3-body system (with unit particle charge) with and accuracy of ∼ 0(1/2M), where 1/2M=(M 1 -1 +M 2 -1 )/2(M 1 -1 +M 3 -1 ) is the small parameter of the adiabatic expansion (M i , i=1,2,3 being particle masses)

  3. The interaction with the lower ionosphere of electromagnetic pulses from lightning: Excitation of optical emissions

    Science.gov (United States)

    Taranenko, Y. N.; Inan, U. S.; Bell, T. F.

    1993-01-01

    A self consistent and fully kinetic simulation of the interaction of lightning radiated electromagnetic (EM) pulses with the nighttime lower ionosphere indicates that optical emissions observable with conventional instruments would be excited. For example, emissions of the 1st and 2nd positive bands of N2 occur at rates reaching 7 x 10(exp 7) and 10(exp 7) cu cm/s respectively at 92 km altitude for a lightning discharge with an electric field E(sub 100) = 20 V/m (normalized to a 100 km distance). The maximum height integrated intensities of these emissions are 4 x 10(exp 7) and 6 x 10(exp 6) R respectively, lasting for approx. 50 micrometers.

  4. High performance interactive graphics for shower reconstruction in HPC, the DELPHI barrel electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Stanescu, C.

    1990-01-01

    Complex software for shower reconstruction in DELPHI barrel electromagnetic calorimeter which deals, for each event, with great amounts of information, due to the high spatial resolution of this detector, needs powerful verification tools. An interactive graphics program, running on high performance graphics display system Whizzard 7555 from Megatek, was developed to display the logical steps in showers and their axes reconstruction. The program allows both operations on the image in real-time (rotation, translation and zoom) and the use of non-geometrical criteria to modify it (as the use of energy) thresholds for the representation of the elements that compound the showers (or of the associated lego plots). For this purpose graphics objects associated to user parameters were defined. Instancing and modelling features of the native graphics library were extensively used

  5. On a testable unification of electromagnetics, general relativity, and quantum mechanics

    International Nuclear Information System (INIS)

    Bearden, T.E.; Rosenthal, W.

    1991-01-01

    Unrecognized for what it was, in 1903-1904 E.T. Whittaker (W) published a fundamental, engineerable theory of electogravitation (EG) in two profound papers. The first (W-1903) demonstrated a hidden bidirectional EM wave structure in the scalar potential of vacuum, and showed how to produce a standing scalar EM potential wave -- the same wave discovered experimentally four years earlier by Nikola Tesla. W-1903 is a hidden variable theory that shows how to determinsitically curve the local and/or distant spacetime using EM. W-1904 shows that all force field EM can be replaced by interferometry of two scalar potentials, anticipating the Aharonov-Bohm effect by 55 years and extending it to the engineerable macroscopic world. W-1903 shows how to turn EM into G-potential, curve local and/or distant spacetime, and directly engineer the virtual particle flux of vacuum. W-1904 shows how to turn G-potential and curvature of spacetime back into force-field EM, even at a distance. The papers implement Sahkarov's 1968 statement that gravitation is not a fundamental field of nature, gut a conglomerate of other fields. Separately applied to electromagnetic (EM), quantum mechanics (QM), and general relativity (GR), an extended superset of each results. The three supersets are Whittaker-unified, so that a testable, engineerable, unified field theory is generated. EM, QM, and GR each contained a fundamental error that blocked unification, and these three errors are explain. The Schroedinger potential can also be structured and altered, indicating the direct engineering of physical quantum change. Recently Ignatovich has pointed out this hidden bidirectional EM wave structure in the Schroedinger potential, without referencing Whittaker's 1903 discovery of the basic effect

  6. Dynamics of a charged particle in a circularly polarized travelling electromagnetic wave. Self-consistent model for the wave-particle dynamical interaction

    International Nuclear Information System (INIS)

    Bourdier, A.

    1999-01-01

    This work concerns mainly the dynamics of a charged particle in an electromagnetic wave. It is a first step in elaborating a more general model permitting to predict the wave-particle interaction. We show how deriving a first integral gives an idea on how to create an electron current in a cold electron plasma. We present results which can be used to test the 2D and 3D Vlasov-Maxwell codes being built up in CEA-DAM. These codes will allow the calcination of the magnetic field created by an electromagnetic wave like the one due to the inverse Faraday effect when a circularly polarized wave drives the electrons of a plasma into circular orbits. (author)

  7. Investigations of the structure and electromagnetic interactions of few-body systems

    International Nuclear Information System (INIS)

    Lehman, D.R.; Haberzettl, H.; Maximon, L.C.; Parke, W.C.

    1992-07-01

    In order to make it easy for the reader to see the specific research carried out and the progress made, the following report of progress is done by topic. Each item has a format layout of Topic, Investigators, Objective, Significance, and Description of Progress, followed at the end by the relevant references. As is clear from the topics listed, the emphasis of the George Washington University (GWU) theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered. When the excitation energy of the target nucleus is low, the aim has been to handle the continuum part of the theoretical work numerically with no approximations, that is, by means of full three- or four-body dynamics. When structure questions axe the issue, numerically accurate calculations axe always carried through, limited only by the underlying two-body or three-body interactions used as input. Implicit in our work is the question of how far one can go within the traditional nuclear physics framework, i.e., nucleons and mesons in a nonrelativistic setting. Our central goal is to carry through state-of-the-art fewbody calculations that wig serve as a means of determining at what point standard nuclear physics requires quark degrees of freedom in order to understand the phenomena in question. So far, in the problems considered, there has been no evidence of the necessity to go beyond the traditional approach, though we always keep in mind that possibility. As our work is involved with questions in the intermediate-energy realm, moving from a nonrelativistic framework to a relativistic one is always a consideration. Currently, for the problems that have been pursued in this domain of energy, the issues concern far more the mechanisms of the reactions and structural questions than the need to move to relativistic dynamics

  8. Investigations of the structure and electromagnetic interactions of few-body systems

    International Nuclear Information System (INIS)

    Lehman, D.R.

    1991-07-01

    In order to make it easy for the reader to see the specific research carried out and the progress make, the following report of progress is done by topic. Each item has a format layout of Topic, Investigators, Objective, Significance, and Description of Progress, followed at the end by the relevant references. As is clear from the topics listed, the emphasis of the GWU theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered. When the excitation energy of the target nucleus is low, the aim has been carry out the continuum part of the theoretical work exactly, this is, by means of exact three- and four-body dynamics. When structure questions are the issue, exact calculations are always carried through, limited only by the underlying two-body or three-body interactions used as input. Implicit in our work is the question of how far one can go within the traditional nuclear physics framework, i.e., nucleons and mesons in a nonrelativistic setting. Our central goal is to carry through state-of-the-art few-body calculations that will serve as an unambiguous means of determining at what point standard nuclear physics requires quark degrees of freedom in order to understand the phenomena in question. So far, in the problems considered, there has been no evidence of the necessity to go beyond the traditional approach, though we always keep in mind that possibility. As our work is involved with questions in the intermediate-energy realm, moving from a nonrelativistic framework to a relativistic one is always a consideration. Currently, for the problems that have been pursued in this domain of energy, the issues concern far more the mechanisms of the reactions and structural questions than the need to move to relativistic dynamics

  9. Environmental Light and Its Relationship with Electromagnetic Resonances of Biomolecular Interactions, as Predicted by the Resonant Recognition Model

    Directory of Open Access Journals (Sweden)

    Irena Cosic

    2016-06-01

    Full Text Available The meaning and influence of light to biomolecular interactions, and consequently to health, has been analyzed using the Resonant Recognition Model (RRM. The RRM proposes that biological processes/interactions are based on electromagnetic resonances between interacting biomolecules at specific electromagnetic frequencies within the infra-red, visible and ultra-violet frequency ranges, where each interaction can be identified by the certain frequency critical for resonant activation of specific biological activities of proteins and DNA. We found that: (1 the various biological interactions could be grouped according to their resonant frequency into super families of these functions, enabling simpler analyses of these interactions and consequently analyses of influence of electromagnetic frequencies to health; (2 the RRM spectrum of all analyzed biological functions/interactions is the same as the spectrum of the sun light on the Earth, which is in accordance with fact that life is sustained by the sun light; (3 the water is transparent to RRM frequencies, enabling proteins and DNA to interact without loss of energy; (4 the spectrum of some artificial sources of light, as opposed to the sun light, do not cover the whole RRM spectrum, causing concerns for disturbance to some biological functions and consequently we speculate that it can influence health.

  10. Interaction between two adjacent grounded sources in frequency domain semi-airborne electromagnetic survey.

    Science.gov (United States)

    Zhou, Haigen; Lin, Jun; Liu, Changsheng; Kang, Lili; Li, Gang; Zeng, Xinsen

    2016-03-01

    Multi-source and multi-frequency emission method can make full use of the valuable and short flight time in frequency domain semi-airborne electromagnetic (FSAEM) exploration, which has potential to investigate the deep earth structure in complex terrain region. Because several sources are adjacent in multi-source emission method, the interaction of different sources should be considered carefully. An equivalent circuit model of dual-source is established in this paper to assess the interaction between two individual sources, where the parameters are given with the typical values based on the practical instrument system and its application. By simulating the output current of two sources in different cases, the influence from the adjacent source is observed clearly. The current waveforms show that the mutual resistance causes the fluctuation and drift in another source and that the mutual inductance causes transient peaks. A field test with dual-source was conducted to certify the existence of interaction between adjacent sources. The simulation of output current also shows that current errors at low frequency are mainly caused by the mutual resistance while those at high frequency are mainly due to the mutual inductance. Increasing the distance between neighboring sources is a proposed measure to reduce the emission signal errors with designed ones. The feasible distance is discussed in the end. This study gives a useful guidance to lay multi sources to meet the requirement of measurement accuracy in FSAEM survey.

  11. General experiments concerning particle-matter interactions

    International Nuclear Information System (INIS)

    Dauvergne, D.

    2006-07-01

    The author gathers in this document several papers he has already published in order to shed light on different aspects concerning ion-crystal interactions. This document is divided into 3 chapters. In the first chapter the author presents results obtained from experiments dedicated to charge exchanges and energy released by heavy ions in channeling conditions. Different processes involved in ion-electron interactions are considered: The tri-electronic recombination, the electron capture through nuclear excitation (NEEC), resonant transfer and excitation (RTE), resonant transfer and double excitation (RTDE) and electron impact ionization (EII). The second chapter deals with the measurement of nuclear fission times through crystal blocking experiments. The crystal blocking technique allows the measurement in a model-independent way of the recoil distance covered by the excited nucleus during the whole fission process (starting from the initial collision and ending at the scission point). The last chapter is dedicated to the photon impact ionization through the conversion of a high-energy photon into an electron-positron pair

  12. Transient analysis of electromagnetic wave interactions on high-contrast scatterers using volume electric field integral equation

    KAUST Repository

    Sayed, Sadeed Bin; Ulku, Huseyin Arda; Bagci, Hakan

    2014-01-01

    A marching on-in-time (MOT)-based time domain volume electric field integral equation (TD-VEFIE) solver is proposed for accurate and stable analysis of electromagnetic wave interactions on high-contrast scatterers. The stability is achieved using

  13. The nucleon-nucleon interaction in the presence of the electromagnetic field: Nucleon-nucleon bremsstrahlung

    International Nuclear Information System (INIS)

    Brown, V.R.

    1990-01-01

    Nucleon-nucleon bremsstrahlung, NNγ, is a fundamental process, which involves the strong and electromagnetic fields acting simultaneously. Since the electromagnetic interaction is well known, NNγ provides a calculable tool for comparing off-energy-shell effects from different two-nucleon potentials compared to experiment and also provides a simple testing ground, which is sensitive to meson-exchange-current contributions that are so important in electronuclear physics. Historically, experimental studies have focused on ppγ, with only a few measurements of npγ. The present workshop was organized primarily to investigate the interest in, the value of, and the feasibility of doing an npγ experiment using the neutron white source at LANL. An increasing amount of US nuclear physics dollars are being spent on electronuclear physics. npγ is a fundamental process with large meson-exchange currents. In the npγ calculations of Brown and Franklin, the meson-exchange contributions increase the cross section by a factor of roughly two and later the angular distribution of the emitted photon dramatically. The details of these calculated effects have never been verified experimentally, but the proper quantum-mechanical inclusion of meson-exchange contributions, using the methods of brown and Franklin, has proved to be essential in understanding the heavy-ion results. The understanding of the importance of such terms is extremely important inelectronuclear processes, such as are presently under investigation or being planned at Bates, SLAC, and CEBAF. Just one example is in the electrodisintegration of the deuteron, where meson-exchange contributions must be included properly before any conclusions about nuclear models, such as QCD versus meson-exchange potentials can be made

  14. Electromagnetic Education in India

    Science.gov (United States)

    Bajpai, Shrish; Asif, Siddiqui Sajida; Akhtar, Syed Adnan

    2016-01-01

    Out of the four fundamental interactions in nature, electromagnetics is one of them along with gravitation, strong interaction and weak interaction. The field of electromagnetics has made much of the modern age possible. Electromagnets are common in day-to-day appliances and are becoming more conventional as the need for technology increases.…

  15. The Interaction of Magnetizations with an External Electromagnetic Field and a Time-Dependent Magnetic Aharonov-Bohm Effect

    International Nuclear Information System (INIS)

    Afanas'ev, G.N.; Stepanovskij, Yu.P.

    1994-01-01

    We investigate how the choice of the magnetization distribution inside the sample affects its interaction with the external electromagnetic field. The strong selectivity to the time dependence of the external electromagnetic field arises for the particular magnetizations. This can be used for the storage and ciphering of information. We propose a time-dependent Aharonov-Bohm-like experiment in which the phase of the wave function is changed by the time-dependent vector magnetic potential. The arising time-dependent interference picture may be viewed as a new channel for the information transfer. 15 refs., 4 figs

  16. Lie symmetries for charged particles in the presence of a general electromagnetic field

    International Nuclear Information System (INIS)

    Medeiros Ritter, Oswaldo de.

    1991-10-01

    We discuss the Lie method and apply it to differential equations obtaining their symmetries. We also discuss methods of how to obtain first integrals from these symmetries. We apply these methods to some interesting physical problems, all of them involving charged particles in electromagnetic fields. (author). 77 refs

  17. The Relativistic Transformation for an Electromagnetic Plane Wave with General Time Dependence

    Science.gov (United States)

    Smith, Glenn S.

    2012-01-01

    In special relativity, the transformation between inertial frames for an electromagnetic plane wave is usually derived for the time-harmonic case (the field is a sinusoid of infinite duration), even though all practical waves are of finite duration and may not even contain a dominant sinusoid. This paper presents an alternative derivation in which…

  18. Interacting institutional logics in general dental practice.

    Science.gov (United States)

    Harris, Rebecca; Holt, Robin

    2013-10-01

    We investigate the organisational field of general dental practice and how agents change or maintain the institution of values associated with the everyday work of health care provision. Our dataset comprise archival literature and policy documents, interview data from field level actors, as well as service delivery level interview data and secondary data gathered (2011-12) from 16 English dental practices. Our analysis provides a typology of institutional logics (prevailing systems of value) experienced in the field of dental practice. Confirming current literature, we find two logics dominate how care is assessed: business-like health care and medical professionalism. We advance the literature by finding the business-like health care logic further distinguished by values of commercialism on the one hand and those of accountability and procedural diligence on the other. The logic of professionalism we also find is further distinguished into a commitment to clinical expertise and independence in delivering patient care on the one hand, and concerns for the autonomy and sustainability of a business enterprise on the other. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Study of Electromagnetic Interactions in the MicroBooNE Liquid Argon Time Projection Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Caratelli, David [Columbia U.

    2018-01-01

    This thesis presents results on the study of electromagnetic (EM) activity in the MicroBooNE Liquid Argon Time Projection Chamber (LArTPC) neutrino detector. The LArTPC detector technology provides bubble-chamber like information on neutrino interaction final states, necessary to perform precision measurements of neutrino oscillation parameters. Accelerator-based oscillation experiments heavily rely on the appearance channel ! e to make such measurements. Identifying and reconstructing the energy of the outgoing electrons from such interactions is therefore crucial for their success. This work focuses on two sources of EM activity: Michel electrons in the 10-50 MeV energy range, and photons from 0 decay in the 30-300 MeV range. Studies of biases in the energy reconstruction measurement, and energy resolution are performed. The impact of shower topology at different energies is discussed, and the importance of thresholding and other reconstruction effects on producing an asymmetric and biased energy measurement are highlighted. This work further presents a study of the calorimetric separation of electrons and photons with a focus on the shower energy dependence of the separation power.

  20. Effects of strong and electromagnetic correlations on neutrino interactions in dense matter

    International Nuclear Information System (INIS)

    Reddy, S.; Prakash, M.; Lattimer, J.M.; Reddy, S.; Pons, J.A.

    1999-01-01

    An extensive study of the effects of correlations on both charged and neutral current weak interaction rates in dense matter is performed. Both strong and electromagnetic correlations are considered. The propagation of particle-hole interactions in the medium plays an important role in determining the neutrino mean free paths. The effects due to Pauli blocking and density, spin, and isospin correlations in the medium significantly reduce the neutrino cross sections. As a result of the lack of experimental information at high density, these correlations are necessarily model dependent. For example, spin correlations in nonrelativistic models are found to lead to larger suppressions of neutrino cross sections compared to those of relativistic models. This is due to the tendency of the nonrelativistic models to develop spin instabilities. Notwithstanding the above caveats, and the differences between nonrelativistic and relativistic approaches such as the spin- and isospin-dependent interactions and the nucleon effective masses, suppressions of order 2 - 3, relative to the case in which correlations are ignored, are obtained. Neutrino interactions in dense matter are especially important for supernova and early neutron star evolution calculations. The effects of correlations for protoneutron star evolution are calculated. Large effects on the internal thermodynamic properties of protoneutron stars, such as the temperature, are found. These translate into significant early enhancements in the emitted neutrino energies and fluxes, especially after a few seconds. At late times, beyond about 10 s, the emitted neutrino fluxes decrease more rapidly compared to simulations without the effects of correlations, due to the more rapid onset of neutrino transparency in the protoneutron star. copyright 1999 The American Physical Society

  1. An analysis of how electromagnetic induction and Faraday's law are presented in general physics textbooks, focusing on learning difficulties

    International Nuclear Information System (INIS)

    Guisasola, Jenaro; Zuza, Kristina; Almudi, José-Manuel

    2013-01-01

    Textbooks are a very important tool in the teaching–learning process and influence important aspects of the process. This paper presents an analysis of the chapter on electromagnetic induction and Faraday's law in 19 textbooks on general physics for first-year university courses for scientists and engineers. This analysis was based on criteria formulated from the theoretical framework of electromagnetic induction in classical physics and students' learning difficulties concerning these concepts. The aim of the work presented here is not to compare a textbook against the ideal book, but rather to try and find a series of explanations, examples, questions, etc that provide evidence on how the topic is presented in relation to the criteria above. It concludes that despite many aspects being covered properly, there are others that deserve greater attention. (paper)

  2. Topological Foundations of Electromagnetism

    CERN Document Server

    Barrett, Terrence W

    2008-01-01

    Topological Foundations of Electromagnetism seeks a fundamental understanding of the dynamics of electromagnetism; and marshals the evidence that in certain precisely defined topological conditions, electromagnetic theory (Maxwell's theory) must be extended or generalized in order to provide an explanation and understanding of, until now, unusual electromagnetic phenomena. Key to this generalization is an understanding of the circumstances under which the so-called A potential fields have physical effects. Basic to the approach taken is that the topological composition of electromagnetic field

  3. Electromagnetic reciprocity in antenna theory

    CERN Document Server

    Stumpf, Martin

    2018-01-01

    The reciprocity theorem is among the most intriguing concepts in wave field theory and has become an integral part of almost all standard textbooks on electromagnetic (EM) theory. This book makes use of the theorem to quantitatively describe EM interactions concerning general multiport antenna systems. It covers a general reciprocity-based description of antenna systems, their EM scattering properties, and further related aspects. Beginning with an introduction to the subject, Electromagnetic Reciprocity in Antenna Theory provides readers first with the basic prerequisites before offering coverage of the equivalent multiport circuit antenna representations, EM coupling between multiport antenna systems and their EM interactions with scatterers, accompanied with the corresponding EM compensation theorems.

  4. Analysis of electromagnetic wave interactions on nonlinear scatterers using time domain volume integral equations

    KAUST Repository

    Ulku, Huseyin Arda

    2014-07-06

    Effects of material nonlinearities on electromagnetic field interactions become dominant as field amplitudes increase. A typical example is observed in plasmonics, where highly localized fields “activate” Kerr nonlinearities. Naturally, time domain solvers are the method of choice when it comes simulating these nonlinear effects. Oftentimes, finite difference time domain (FDTD) method is used for this purpose. This is simply due to the fact that explicitness of the FDTD renders the implementation easier and the material nonlinearity can be easily accounted for using an auxiliary differential equation (J.H. Green and A. Taflove, Opt. Express, 14(18), 8305-8310, 2006). On the other hand, explicit marching on-in-time (MOT)-based time domain integral equation (TDIE) solvers have never been used for the same purpose even though they offer several advantages over FDTD (E. Michielssen, et al., ECCOMAS CFD, The Netherlands, Sep. 5-8, 2006). This is because explicit MOT solvers have never been stabilized until not so long ago. Recently an explicit but stable MOT scheme has been proposed for solving the time domain surface magnetic field integral equation (H.A. Ulku, et al., IEEE Trans. Antennas Propag., 61(8), 4120-4131, 2013) and later it has been extended for the time domain volume electric field integral equation (TDVEFIE) (S. B. Sayed, et al., Pr. Electromagn. Res. S., 378, Stockholm, 2013). This explicit MOT scheme uses predictor-corrector updates together with successive over relaxation during time marching to stabilize the solution even when time step is as large as in the implicit counterpart. In this work, an explicit MOT-TDVEFIE solver is proposed for analyzing electromagnetic wave interactions on scatterers exhibiting Kerr nonlinearity. Nonlinearity is accounted for using the constitutive relation between the electric field intensity and flux density. Then, this relation and the TDVEFIE are discretized together by expanding the intensity and flux - sing half

  5. Conversion of electromagnetic waves at the ionisation front

    International Nuclear Information System (INIS)

    Chegotov, M V

    2001-01-01

    It is shown that a weak electromagnetic pulse interacting with a copropagating ionisation front is converted in the general case into three electromagnetic pulses with higher and lower frequencies, which propagate in different directions. The coefficients of conversion to these pulses (for intensities) were found as functions of the frequency. The electromagnetic energy is shown to decrease during this conversion because of the losses for the residual electron energy. (interaction of laser radiation with matter. laser plasma)

  6. General expressions and physical origin of the coupling coefficient of arbitrary tuned coupled electromagnetic resonators

    Energy Technology Data Exchange (ETDEWEB)

    Elnaggar, Sameh Y. [School of Engineering and Information Technology, University of New South Wales, Canberra (Australia); Tervo, Richard J. [Department of Electrical and Computer Engineering, University of New Brunswick, Fredericton, NB, E3B 5A3 Canada (Canada); Mattar, Saba M., E-mail: mattar@unb.ca [Chemistry Department, University of New Brunswick, Fredericton, NB, E3B 5A3 Canada (Canada)

    2015-11-21

    The theory and operation of various devices and systems, such as wireless power transfer via magnetic resonant coupling, magneto-inductive wave devices, magnetic resonance spectroscopy probes, and metamaterials can rely on coupled tuned resonators. The coupling strength is usually expressed in terms of the coupling coefficient κ, which can have electrical κ{sub E} and/or magnetic κ{sub M} components. In the current article, general expressions of κ are derived. The relation between the complex Poynting equation in its microscopic form and κ is made and discussed in detail. It is shown that κ can be expressed in terms of the interaction energy between the resonators' modes. It thus provides a general form that combines the magnetic and electric components of κ. The expressions make it possible to estimate the frequencies and fields of the coupled modes for arbitrarily oriented and spaced resonators. Thus, enabling the calculation of system specific parameters such as the transfer efficiency of wireless power transfer systems, resonator efficiency for electron spin resonance probes, and dispersion relations of magneto-inductive and stereo-metamaterials structures.

  7. General expressions and physical origin of the coupling coefficient of arbitrary tuned coupled electromagnetic resonators

    International Nuclear Information System (INIS)

    Elnaggar, Sameh Y.; Tervo, Richard J.; Mattar, Saba M.

    2015-01-01

    The theory and operation of various devices and systems, such as wireless power transfer via magnetic resonant coupling, magneto-inductive wave devices, magnetic resonance spectroscopy probes, and metamaterials can rely on coupled tuned resonators. The coupling strength is usually expressed in terms of the coupling coefficient κ, which can have electrical κ E and/or magnetic κ M components. In the current article, general expressions of κ are derived. The relation between the complex Poynting equation in its microscopic form and κ is made and discussed in detail. It is shown that κ can be expressed in terms of the interaction energy between the resonators' modes. It thus provides a general form that combines the magnetic and electric components of κ. The expressions make it possible to estimate the frequencies and fields of the coupled modes for arbitrarily oriented and spaced resonators. Thus, enabling the calculation of system specific parameters such as the transfer efficiency of wireless power transfer systems, resonator efficiency for electron spin resonance probes, and dispersion relations of magneto-inductive and stereo-metamaterials structures

  8. Transient analysis of electromagnetic wave interactions on plasmonic nanostructures using a surface integral equation solver

    KAUST Repository

    Uysal, Ismail Enes

    2016-08-09

    Transient electromagnetic interactions on plasmonic nanostructures are analyzed by solving the Poggio-Miller-Chan-Harrington-Wu-Tsai (PMCHWT) surface integral equation (SIE). Equivalent (unknown) electric and magnetic current densities, which are introduced on the surfaces of the nanostructures, are expanded using Rao-Wilton-Glisson and polynomial basis functions in space and time, respectively. Inserting this expansion into the PMCHWT-SIE and Galerkin testing the resulting equation at discrete times yield a system of equations that is solved for the current expansion coefficients by a marching on-in-time (MOT) scheme. The resulting MOT-PMCHWT-SIE solver calls for computation of additional convolutions between the temporal basis function and the plasmonic medium\\'s permittivity and Green function. This computation is carried out with almost no additional cost and without changing the computational complexity of the solver. Time-domain samples of the permittivity and the Green function required by these convolutions are obtained from their frequency-domain samples using a fast relaxed vector fitting algorithm. Numerical results demonstrate the accuracy and applicability of the proposed MOT-PMCHWT solver. © 2016 Optical Society of America.

  9. Interaction of Electromagnetic Waves with Two-Dimensional Metal Covered with Radar Absorbing Material and Plasma

    International Nuclear Information System (INIS)

    Lan Chaohui; Hu Xiwei; Jiang Zhonghe

    2008-01-01

    A two-dimensional metal model is established to investigate the stealth mechanisms of radar absorbing material (RAM) and plasma when they cover the model together. Using the finite-difference time-domain (FDTD) method, the interaction of electromagnetic (EM) waves with the model can be studied. In this paper, three covering cases are considered: a. RAM or plasma covering the metal solely; b. RAM and plasma covering the metal, while plasma is placed outside; c. RAM and plasma covering the metal, while RAM is placed outside. The calculated results show that the covering order has a great influence on the absorption of EM waves. Compared to case a, case b has an advantage in the absorption of relatively high-frequency EM waves (HFWs), whereas case c has an advantage in the absorption of relatively low-frequency EM waves (LFWs). Through the optimization of the parameters of both plasma and RAM, it is hopeful to obtain a broad absorption band by RAM and plasma covering. Near-field attenuation rate and far-field radar cross section (RCS) are employed to compare the different cases. (low temperature plasma)

  10. Large-aperture Tunable Plasma Meta-material to Interact with Electromagnetic Waves

    Science.gov (United States)

    Corke, Thomas; Matlis, Eric

    2016-11-01

    The formation of spatially periodic arrangements of glow discharge plasma resulting from charge instabilities were investigated as a tuneable plasma meta-material. The plasma was formed between two 2-D parallel dielectric covered electrodes: one consisting of an Indium-Tin-Oxide coated glass sheet, and the other consisting of a glass-covered circular electrode. The dielectric covered electrodes were separated by a gap that formed a 2-D channel. The gap spacing was adjustable. The electrodes were powered by a variable amplitude AC generator. The parallel electrode arrangement was placed in a variable pressure vacuum chamber. Various combinations of gap spacing, pressure and voltage resulted in the formation of spatially periodic arrangements (lattice) of glow discharge plasma. The lattice spacing perfectly followed 2-D packing theory, and was fully adjustable through the three governing parameters. Lattice arrangements were designed to interact with electromagnetic (EM) waves in the frequency range between 10GHz-80GHz. Its feasibility was investigate through an EM wave simulation that we adapted to allow for plasma permittivity. The results showed a clear suppression of the EM wave amplitude through the plasma gratings. Supported by AFOSR.

  11. A class of algebraically general solutions of the Einstein-Maxwell equations for non-null electromagnetic fields

    International Nuclear Information System (INIS)

    Tupper, B.O.J.

    1976-01-01

    In a previous article (Gen. Rel. Grav.; 6 : 345 (1975)) the Einstein-Maxwell field equations for non-null electromagnetic fields were studied under the conditions that the null tetrad is parallel-propagated along both principal null congruences. A solution with twist and shear, but no expansion, was found and was conjectured to be the only expansion-free solution. Here it is shown that this conjecture is false; the general expansion-free solution is found to be a family of space-times depending on a single constant parameter which is the ratio of the (constant) twists of the two principal null congruences. (author)

  12. Modeling of Mutiscale Electromagnetic Magnetosphere-Ionosphere Interactions near Discrete Auroral Arcs Observed by the MICA Sounding Rocket

    Science.gov (United States)

    Streltsov, A. V.; Lynch, K. A.; Fernandes, P. A.; Miceli, R.; Hampton, D. L.; Michell, R. G.; Samara, M.

    2012-12-01

    The MICA (Magnetosphere-Ionosphere Coupling in the Alfvén Resonator) sounding rocket was launched from Poker Flat on February 19, 2012. The rocket was aimed into the system of discrete auroral arcs and during its flight it detected small-scale electromagnetic disturbances with characteristic features of dispersive Alfvén waves. We report results from numerical modeling of these observations. Our simulations are based on a two-fluid MHD model describing multi-scale interactions between magnetic field-aligned currents carried by shear Alfven waves and the ionosphere. The results from our simulations suggest that the small-scale electromagnetic structures measured by MICA indeed can be interpreted as dispersive Alfvén waves generated by the active ionospheric response (ionopspheric feedback instability) inside the large-scale downward magnetic field-aligned current interacting with the ionosphere.

  13. Studies on the C*-algebraic formulation of the interaction of the electromagnetic field with the matter

    International Nuclear Information System (INIS)

    Majewski, W.A.

    1978-01-01

    In recent years C*-algebra concepts have been suggested for dealing rigorously with mathematical difficulties of Quantum Field Theory. To demonstrate some of the possibilities of these concepts it is presented the sketch for the description of interaction of the electromagnetic field with the matter. In particular the asymptotic of the perturbed state of the field, explicit form of such state and notion of coherence on the Weyl system are studied

  14. General aviation design synthesis utilizing interactive computer graphics

    Science.gov (United States)

    Galloway, T. L.; Smith, M. R.

    1976-01-01

    Interactive computer graphics is a fast growing area of computer application, due to such factors as substantial cost reductions in hardware, general availability of software, and expanded data communication networks. In addition to allowing faster and more meaningful input/output, computer graphics permits the use of data in graphic form to carry out parametric studies for configuration selection and for assessing the impact of advanced technologies on general aviation designs. The incorporation of interactive computer graphics into a NASA developed general aviation synthesis program is described, and the potential uses of the synthesis program in preliminary design are demonstrated.

  15. Magnetohydrodynamic Electromagnetic Pulse (MHD-EMP) Interaction with Power Transmission and Distribution Systems

    National Research Council Canada - National Science Library

    Tesche, F. M; Barnes, P. R; Meliopoulos, A. P

    1992-01-01

    .... This environment, known as the magnetohydrodynamic electromagnetic pulse (MHD-EMP , is a very slowly varying electric field induced in the earth's surface, similar to the field induced by a geomagnetic storm...

  16. Electromagnetic topology: Characterization of internal electromagnetic coupling

    Science.gov (United States)

    Parmantier, J. P.; Aparicio, J. P.; Faure, F.

    1991-01-01

    The main principles are presented of a method dealing with the resolution of electromagnetic internal problems: Electromagnetic Topology. A very interesting way is to generalize the multiconductor transmission line network theory to the basic equation of the Electromagnetic Topology: the BLT equation. This generalization is illustrated by the treatment of an aperture as a four port junction. Analytical and experimental derivations of the scattering parameters are presented. These concepts are used to study the electromagnetic coupling in a scale model of an aircraft, and can be seen as a convenient means to test internal electromagnetic interference.

  17. Advanced methods for the computation of particle beam transport and the computation of electromagnetic fields and beam-cavity interactions

    International Nuclear Information System (INIS)

    Dragt, A.J.; Gluckstern, R.L.

    1992-11-01

    The University of Maryland Dynamical Systems and Accelerator Theory Group carries out research in two broad areas: the computation of charged particle beam transport using Lie algebraic methods and advanced methods for the computation of electromagnetic fields and beam-cavity interactions. Important improvements in the state of the art are believed to be possible in both of these areas. In addition, applications of these methods are made to problems of current interest in accelerator physics including the theoretical performance of present and proposed high energy machines. The Lie algebraic method of computing and analyzing beam transport handles both linear and nonlinear beam elements. Tests show this method to be superior to the earlier matrix or numerical integration methods. It has wide application to many areas including accelerator physics, intense particle beams, ion microprobes, high resolution electron microscopy, and light optics. With regard to the area of electromagnetic fields and beam cavity interactions, work is carried out on the theory of beam breakup in single pulses. Work is also done on the analysis of the high frequency behavior of longitudinal and transverse coupling impedances, including the examination of methods which may be used to measure these impedances. Finally, work is performed on the electromagnetic analysis of coupled cavities and on the coupling of cavities to waveguides

  18. A theory of strong interactions ''from'' general relativity

    International Nuclear Information System (INIS)

    Caldirola, P.; Recami, E.

    1979-01-01

    In this paper a previous letter (where, among other things, a classical ''quark confinement'' was derived from general relativity plus dilatation-covariance), is completed by showing that the theory is compatible also with quarks ''asymptotic freedom''. Then -within a bi-scale theory of gravitational and strong interactions- a classical field theory is proposed for the (strong) interactions between hadrons. Various consequences are briefly analysed

  19. Sampling general N-body interactions with auxiliary fields

    Science.gov (United States)

    Körber, C.; Berkowitz, E.; Luu, T.

    2017-09-01

    We present a general auxiliary field transformation which generates effective interactions containing all possible N-body contact terms. The strength of the induced terms can analytically be described in terms of general coefficients associated with the transformation and thus are controllable. This transformation provides a novel way for sampling 3- and 4-body (and higher) contact interactions non-perturbatively in lattice quantum Monte Carlo simulations. As a proof of principle, we show that our method reproduces the exact solution for a two-site quantum mechanical problem.

  20. Entanglement between two interacting CFTs and generalized holographic entanglement entropy

    International Nuclear Information System (INIS)

    Mollabashi, Ali; Shiba, Noburo; Takayanagi, Tadashi

    2014-01-01

    In this paper we discuss behaviors of entanglement entropy between two interacting CFTs and its holographic interpretation using the AdS/CFT correspondence. We explicitly perform analytical calculations of entanglement entropy between two free scalar field theories which are interacting with each other in both static and time-dependent ways. We also conjecture a holographic calculation of entanglement entropy between two interacting N=4 super Yang-Mills theories by introducing a minimal surface in the S 5 direction, instead of the AdS 5 direction. This offers a possible generalization of holographic entanglement entropy

  1. Risk factors for potential drug interactions in general practice

    DEFF Research Database (Denmark)

    Bjerrum, Lars; Gonzalez Lopez-Valcarcel, Beatriz; Petersen, Gert

    2008-01-01

    interactions during 1 year. Patient factors associated with increased risk of potential drug interactions were high age, a high number of concurrently used drugs, and a high number of prescribers. Practice factors associated with potential drug interactions were a high percentage of elderly patients and a low......Objective: To identify patient- and practice-related factors associated with potential drug interactions. Methods: A register analysis study in general practices in the county of Funen, Denmark. Prescription data were retrieved from a population-based prescription database (Odense University......, depending on the severity of outcome and the quality of documentation. A two-level random coefficient logistic regression model was used to investigate factors related to potential drug interactions. Results: One-third of the population was exposed to polypharmacy, and 6% were exposed to potential drug...

  2. Reemission spectra and inelastic processes at interaction of attosecond and shorter duration electromagnetic pulses with atoms

    International Nuclear Information System (INIS)

    Makarov, D.N.; Matveev, V.I.

    2017-01-01

    Inelastic processes and the reemission of attosecond and shorter electromagnetic pulses by atoms have been considered within the analytical solution of the Schrödinger equation in the sudden perturbation approximation. A method of calculations with the exact inclusion of spatial inhomogeneity of the field of an ultrashort pulse and the momenta of photons in the reemission processes has been developed. The probabilities of inelastic processes and spectra of reemission of ultrashort electromagnetic pulses by one- and many-electron atoms have been calculated. The results have been presented in the form of analytical formulas.

  3. The SEM description of interaction of a transient electromagnetic wave with an object

    Science.gov (United States)

    Pearson, L. W.; Wilton, D. R.

    1980-01-01

    The singularity expansion method (SEM), proposed as a means for determining and representing the transient surface current density induced on a scatterer by a transient electromagnetic wave is described. The resulting mathematical description of the transient surface current on the object is discussed. The data required to represent the electromagnetic scattering properties of a given object are examined. Experimental methods which were developed for the determination of the SEM description are discussed. The feasibility of characterizing the surface current induced on aircraft flying in proximity to a lightning stroke by way of SEM is examined.

  4. Electromagnetic radiation reaction force and radiation potential in general five-dimensional relativity

    International Nuclear Information System (INIS)

    Lo, C.Y.; Goldstein, G.R.; Napier, A.

    1989-01-01

    A unified theory of electromagnetic and gravitational fields should modify classical electrodynamics to account for the radiation reaction force. A conjecture that the radiation reaction force and the Lorentz force should be distinct, but in unified forms, results in a five-dimensional unified theory of five variables. It is found that a semicylindrical condition can reconcile the apparent differences between a five-dimensional physical space and our four-dimensional perceptions. Analysis of the geodesic equations results in the notion of gauge dynamics which manifests the influence of the unrestricted fifth variable. The element g 55 of the five-dimensional metric is identified as the radiation potential, which can directly determine the radiation reaction force. This gives a distinct physical origin for the radiation process in classical theory. The potential suggests that the electron can have excited states in quantum electrodynamics. This theory is supported with calculations which demonstrate that the motion of the fifth variable directly causes physical changes in the four-dimensional subspace

  5. Medical Information Management System (MIMS): A generalized interactive information system

    Science.gov (United States)

    Alterescu, S.; Friedman, C. A.; Hipkins, K. R.

    1975-01-01

    An interactive information system is described. It is a general purpose, free format system which offers immediate assistance where manipulation of large data bases is required. The medical area is a prime area of application. Examples of the system's operation, commentary on the examples, and a complete listing of the system program are included.

  6. Aspects of the theory of atoms and coherent matter and their interaction with electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Nilsen, Halvor Moell

    2002-07-01

    In the present work I have outlined and contributed to the time-dependent theory of the interaction between atoms and electromagnetic fields and the theory of Bose-Einstein condensates. New numerical methods and algorithms have been developed and applied in practice. Calculations have exhibited certain new dynamical features. All these calculations are in a regime where the applied field is of the same magnitude as the atomic field. In the case of BEC we have investigated the use of time-dependent methods to calculate the excitation frequencies. We also investigated the possibility of nonlinear coupling for a scissors mode and found no such contributions to damping which is consistent with other studies . Special emphasis has also been paid to the gyroscopic motion of rotating BEC where several models were investigated. Briefly, the main conclusions are: (1) Rydberg wave packets appear for direct excitations of Rydberg atoms for long pulses. (2) The survival of just a few states is decided by symmetry of the Hamiltonian. (3) For few cycle intense pulses classical and quantum mechanics show remarkable similarity. (4) Time-dependent methods for finding excitation frequencies have been shown to be very efficient. (5) New dynamical features is shown in gyroscopic motion of BEC. (6) It was shown that no nonlinear mixing of scissors modes occur in the standard Gross-Pitaevskii regime. As mentioned in the introduction, this work is a part of very active research fields and new progress is constantly reported. Thus, the present work cannot be concluded as a closed loop. The fast development of grid based numerical solutions for atoms in intense fields will surely make great contribution to solve many of today's problems. It is a very important area of research to understand both nonperturbative atomic response and highly nonlinear optics. In the field of Bose-Einstein condensation the new experimental achievements constantly drive the field forward. The new

  7. Electromagnetic fields and their impacts

    Science.gov (United States)

    Prša, M. A.; Kasaš-Lažetić, K. K.

    2018-01-01

    The main goal of this paper is to briefly recall some different electromagnetic field definitions, some macroscopic sources of electromagnetic fields, electromagnetic fields classification regarding time dependences, and the ways of field determination in concrete cases. After that, all the mechanisms of interaction between electromagnetic field and substance, on atomic level, are described in details. Interaction between substance and electric field is investigated separately from the substance and magnetic field interaction. It is demonstrated that, in all cases of the unique electromagnetic field, total interaction can be treated as a superposition of two separated interactions. Finally, the main electromagnetic fields surrounding us is cited and discussed.

  8. A Data Analysis Center for Electromagnetic and Hadronic Interaction. Products of the DAC members

    Energy Technology Data Exchange (ETDEWEB)

    Briscoe, William John [George Washington Univ., Washington, DC (United States); Strakovsky, Igor I. [George Washington Univ., Washington, DC (United States); Workman, Ronald L. [George Washington Univ., Washington, DC (United States)

    2015-08-31

    The Data Analysis Center (DAC) of the Center for Nuclear Studies (CNS) at the George Washington University (GW) has made significant progress in its program to enhance and expand the partial-wave (and multipole) analyses of fundamental two- and three-body reactions (such as pion-nucleon, photon-nucleon, and nucleon-nucleon scattering) by maintaining and augmenting the analysis codes and databases associated with these reactions. These efforts provide guidance to experimental groups at the international level, forming an important link between theory and experiment. A renaissance in light hadron spectroscopy is underway as a continuous stream of polarization data issues from existing precision electromagnetic facilities and the coming Jefferson Lab 12 GeV Upgrade. Our principal goals have been focused on supporting the national N* resonance physics program. We have also continued to study topics more generally related to the problems associated with partial-wave analysis. On the Experimental side of the CNS DAC. Its primary goal is the enhancement of the body of data necessary for our analyses of fundamental γ - N reactions. We perform experiments that study the dynamics responsible for the internal structure of the nucleon and its excitations. Our principal focus is on the N* programs at JLab and MAMI. At JLab we study spin-polarization observables using polarized photons, protons and neutrons and yielding charged final states. Similarly at MAMI we study neutral meson photoproduction off polarized protons and neutrons. We use the Crystal Ball and TAPS spectrometers (CBT) to detect photons and neutrons to measure the photoproduction of π0, η, 2π0, π0η, and K0 off the neutron. The CBT program complements our program at JLab, which studies reactions resulting in charged final states. We are also involved in a renewed effort to make neutral pion photoproduction measurements close to threshold at Mainz. In addition to the programs underway, we are contributing to

  9. Investigation of Interaction between Deferoxamine and Low Frequency Electromagnetic Field on Angiogenesis in Chick Embryo

    Directory of Open Access Journals (Sweden)

    Atena Dashtizadeh

    2015-02-01

    Full Text Available Background: Deferoxamine (DFO is an iron chelator. In the present research, the synergic effects of deferoxamine and electromagnetic field (with 50 H frequency and 100 Gauss intensity on angiogenesis of chick chorioallantoic membrane were investigated. Materials and Methods: In this experimental study 80 fertilized egg used and randomly divided 8 group: control group, laboratory control groups of 1 and 2, experimental group 1 (treatment with electromagnetic field, 2 and 3 (treatment with deferoxamine 10, 100 µmol, respectively, 4 and 5 (treatment both deferoxamine 10 and 100 µmol respectively and electromagnetic field. On 8th day of incubation, 2 and 4 groups were incubated with 10 µL deferoxamine and for 3 and 5 groups were incubated with 10 µL deferoxamine 100 µmol. On 10th day, 1, 4 and 5 groups were put in electromagnetic field. On 12th day, the number and length of vessels in all samples was measured by Image J software. Data were analyzed by SPSS-19, ANOVA and t-test. Results: The mean number and length of vessels in the control and experimental cases did not show any significant differences. Comparison between mean number of vessels in the control and group 2, 3, 4, 5 showed a significant decrease (p<0.05 and groups 2 and 4 was showed a significant decrease in the mean length of vessels compared with the controls (p<0.05. Conclusion: Using deferoxamine with low frequency electromagnetic field (50 Hz and 100 G cause inhibition of angiogenesis in chick embryo chorioallantoic membrane.

  10. Interacting holographic dark energy models: a general approach

    Science.gov (United States)

    Som, S.; Sil, A.

    2014-08-01

    Dark energy models inspired by the cosmological holographic principle are studied in homogeneous isotropic spacetime with a general choice for the dark energy density . Special choices of the parameters enable us to obtain three different holographic models, including the holographic Ricci dark energy (RDE) model. Effect of interaction between dark matter and dark energy on the dynamics of those models are investigated for different popular forms of interaction. It is found that crossing of phantom divide can be avoided in RDE models for β>0.5 irrespective of the presence of interaction. A choice of α=1 and β=2/3 leads to a varying Λ-like model introducing an IR cutoff length Λ -1/2. It is concluded that among the popular choices an interaction of the form Q∝ Hρ m suits the best in avoiding the coincidence problem in this model.

  11. Parametric excitation of very low frequency (VLF) electromagnetic whistler waves and interaction with energetic electrons in radiation belt

    Science.gov (United States)

    Sotnikov, V.; Kim, T.; Caplinger, J.; Main, D.; Mishin, E.; Gershenzon, N.; Genoni, T.; Paraschiv, I.; Rose, D.

    2018-04-01

    The concept of a parametric antenna in ionospheric plasma is analyzed. Such antennas are capable of exciting electromagnetic radiation fields, specifically the creation of whistler waves generated at the very low frequency (VLF) range, which are also capable of propagating large distances away from the source region. The mechanism of whistler wave generation is considered a parametric interaction of quasi-electrostatic whistler waves (also known as low oblique resonance (LOR) oscillations) excited by a conventional loop antenna. The interaction of LOR waves with quasi-neutral density perturbations in the near field of an antenna gives rise to electromagnetic whistler waves on combination frequencies. It is shown in this work that the amplitude of these waves can considerably exceed the amplitude of whistler waves directly excited by a loop. Additionally, particle-in-cell simulations, which demonstrate the excitation and spatial structure of VLF waves excited by a loop antenna, are presented. Possible applications including the wave-particle interactions to mitigate performance anomalies of low Earth orbit satellites, active space experiments, communication via VLF waves, and modification experiments in the ionosphere will be discussed.

  12. Semiclassical interaction between monochromatic electromagnetic radiation and an atom with two unstable levels; some fallacious works by Kamenov-Bonchev

    International Nuclear Information System (INIS)

    Romashev, Yu. A.; Skorobogatov, G.A.

    1999-01-01

    The solution of the time-dependent Hamiltonian for the classical dipole interaction of a two-level atom with a monochromatic electromagnetic wave is presented. Both atomic energy levels are assumed to be unstable. The amplitudes and probabilities of transitions between the energy levels as well as the cross-sections of resonance absorption and induced emission are obtained explicitly. It is shown that in both stationary and nonstationary limits the instability of the lower level does not lead to a differential cross section of induced emission larger than those obtained from the Breit-Wigner formula in the standard collision theory. (authors)

  13. On parasupersymmetries and relativistic descriptions for spin one particles. Pt. 2. The interacting context with (electro)magnetic fields

    International Nuclear Information System (INIS)

    Beckers, J.; Debergh, N.; Nikitin, A.G.

    1995-01-01

    This second part belongs to a series of two papers devoted to a constructive review of the relativistic wave equations for vector mesons due to the recent impact of spin one developments in connection with parasupersymmetric quantum mechanics. Here, the mesons are interacting with external (electro)magnetic fields but the simplest context of homogeneous constant magnetic fields directed along the z-axis is particularly studied. Discussions on reality of energy eigenvalues, on causal propagation and on gyromagnetic ratios are especially presented. Supersymmetries and parasupersymmetries are analysed with respect to new pseudosupersymmetries suggested by these developments in one particular context. (orig.)

  14. Advanced methods for the computation of particle beam transport and the computation of electromagnetic fields and beam-cavity interactions. Progress report, July 1993--August 1994

    International Nuclear Information System (INIS)

    Dragt, A.J.; Gluckstern, R.L.

    1994-08-01

    The University of Maryland Dynamical Systems and Accelerator Theory Group has been carrying out long-term research work in the general area of Dynamical Systems with a particular emphasis on applications to Accelerator Physics. This work is broadly divided into two tasks: the computation of charged particle beam transport and the computation of electromagnetic fields and beam-cavity interactions. Each of these tasks is described briefly. Work is devoted both to the development of new methods and the application of these methods to problems of current interest in accelerator physics including the theoretical performance of present and proposed high energy machines. In addition to its research effort, the Dynamical Systems and Accelerator Theory Group is actively engaged in the education of students and postdoctoral research associates. Substantial progress in research has been made during the past year. These achievements are summarized in the following report

  15. Improvement of localised corrosion resistance of AISI 2205 Duplex Stainless Steel joints made by gas metal arc welding under electromagnetic interaction of low intensity

    Science.gov (United States)

    García-Rentería, M. A.; López-Morelos, V. H.; García-Hernández, R.; Dzib-Pérez, L.; García-Ochoa, E. M.; González-Sánchez, J.

    2014-12-01

    The resistance to localised corrosion of AISI 2205 duplex stainless steel plates joined by Gas Metal Arc Welding (GMAW) under the effect of electromagnetic interaction of low intensity (EMILI) was evaluated with sensitive electrochemical methods. Welds were made using two shielding gas mixtures: 98% Ar + 2% O2 (M1) and 97% Ar + 3% N2 (M2). Plates were welded under EMILI using the M1 gas with constant welding parameters. The modified microstructural evolution in the high temperature heat affected zone and at the fusion zone induced by application of EMILI during welding is associated with the increase of resistance to localised corrosion of the welded joints. Joints made by GMAW using the shielding gas M2 without the application of magnetic field presented high resistance to general corrosion but high susceptibility to undergo localised attack.

  16. Predictions of baryon form factors for the electromagnetic and weak interaction

    International Nuclear Information System (INIS)

    Kiehlmann, H.D.

    1978-05-01

    The electromagnetic and weak form factors of the baryon matrix elements (with B the nucleon or the Λ(1232)-resonance) are determined via sumrules by the experimentally known form factors of the nucleon matrix element for momentum transfers 0 2 2 . The operator Jμ denotes either the electromagnetic current or the weak hypercharge-conserving current of the I. class. The sumrules are derived from the superconvergence of properly chosen reaction amplitudes. The results allow an absolute determination of the cross sections of a series of peripheral reactions. An important and interesting consequence for the considered matrix elements of the weak current is that the properties of CVC of PCAC follow from the sumrules without additional assumptions. Finally the predictions of relativistic SU(6)-models are checked. One gets surprisingly a good confirmation of the essential results of these models, the reliability of which has almost been unknown on account of a series of speculative assumptions. (orig.) [de

  17. Interactions of Low-Frequency, Pulsed Electromagnetic Fields with Living Tissue: Biochemical Responses and Clinical Results

    DEFF Research Database (Denmark)

    Rahbek, Ulrik L.; Tritsaris, Katerina; Dissing, Steen

    2005-01-01

    In recent years many studies have demonstrated stimulatory effects of pulsed electromagnetic fields (PEMF) on biological tissue. However, controversies have also surrounded the research often due to the lack of knowledge of the different physical consequences of static versus pulsed electromagnetic......, are still lacking. Despite the apparent success of the PEMF technology very little is known regarding the coupling between pulsed electrical fields and biochemical events leading to cellular responses. Insight into this research area is therefore of great importance. In this review we describe the physical...... properties of PEMF-induced electrical fields and explain the typical set up for coils and pulse patterns. Furthermore, we discuss possible models that can account for mechanisms by which induced electric fields are able to enhance cellular signaling. We have emphasized the currently well-documented effects...

  18. Electromagnetic soliton production during interaction of relativistically strong laser pulses with plasma

    International Nuclear Information System (INIS)

    Bulanov, S.V.; Esirkepov, T.Zh.; Kamenets, F.F.; Naumova, N.M.

    1995-01-01

    The paper presents the results of a numeric modelling of the propagation of ultra short relativistically strong laser pulses in a rarefied plasma by the 'particle in cell'. Primary attention is paid to the process of the formation of electromagnetic solitons which can not be described in the approximation of envelopes. It is found that under certain conditions a significant portion of pulse energy can transform is solitons. The soliton excitation mechanism is related to a decrease of local frequency of electromagnetic radiation due to the generation of wave plasma waves. From one soliton to a stub of solitons can be generated in the wake of a relatively long pulse depending on the parameters of laser pulse in plasma. Particles are effectively accelerated forwards radiation propagation in the electric field of wake plasma waves. 22 refs., 7 figs

  19. A generalized resonating group method with absorptive interaction

    International Nuclear Information System (INIS)

    Hernandez, E.; Mondragon, A.; Instituto Nacional de Investigaciones Nucleares, Mexico City)

    1981-01-01

    A generalized Hill-Wheeler equation for the elastic collision at two composite nuclei is obtained projecting the complete many-body Schroedinger equation on the subspace of model internal wave functions and on its orthogonal complement. We get a new, non hermitian (absorptive) interaction term W which takes into account the flux loss in the elastic channel, besides the usual RGM effective Hamiltonian and normalization kernels. A perturbation series expansion for W containing only linked diagrams is given. Finally, the antisymmetrized product of internal wave functions of the fragments that appear in the projection operator is expressed in terms of complex generator coordinates, then the terms appearing in effective interaction can be written as matrix elements of the microscopic interactions and/or the antisymmetrizer between two center shell model states. (author)

  20. A more general interacting model of holographic dark energy

    International Nuclear Information System (INIS)

    Yu Fei; Zhang Jingfei; Lu Jianbo; Wang Wei; Gui Yuanxing

    2010-01-01

    So far, there have been no theories or observational data that deny the presence of interaction between dark energy and dark matter. We extend naturally the holographic dark energy (HDE) model, proposed by Granda and Oliveros, in which the dark energy density includes not only the square of the Hubble scale, but also the time derivative of the Hubble scale to the case with interaction and the analytic forms for the cosmic parameters are obtained under the specific boundary conditions. The various behaviors concerning the cosmic expansion depend on the introduced numerical parameters which are also constrained. The more general interacting model inherits the features of the previous ones of HDE, keeping the consistency of the theory.

  1. Limits on new forces coexisting with electromagnetism

    International Nuclear Information System (INIS)

    Kloor, H.; Fischbach, E.; Talmadge, C.; Greene, G.L.

    1994-01-01

    We consider the limits arising from different electromagnetic systems on the existence of a possible new electromagnetic analogue of the fifth force. Although such a force may have no intrinsic connection to electromagnetism (or gravity), its effects could be manifested through various anomalies in electromagnetic systems, for appropriate values of the coupling strength and range. Our work generalizes that of Bartlett and Loegl (who considered the case of a massive vector field coexisting with massless electrodynamics) to encompass a broad class of phenomenological interactions mediated by both scalar and vector exchanges. By combining data from both gravitational and electromagnetic systems, one can eventually set limits on a new force whose range λ extends from the subatomic scale (λ∼10 -15 m) to the astrophysical scale (λ∼10 12 m)

  2. A hybrid DGTD scheme for transient analysis of electromagnetic field interactions on microwave systems loaded with thin wires

    KAUST Repository

    Li, Ping

    2015-10-15

    Use of the discontinuous Galerkin time-domain (DGTD) method for analyzing electromagnetic field interactions on microwave structures loaded with thin wires has been very limited despite its well-known advantages. Direct application of the three dimensional (3D) DGTD method to such structures calls for very fine volumetric discretizations in the proximity of the thin wires. In this work, to avoid this possible source of computational inefficiency, electromagnetic field interactions on thin wires and the rest of the structures are modeled separately using the modified telegrapher and Maxwell equations, respectively. Then, 1D and 3D DGTD methods are used to discretize them. The coupling between the two resulting matrix systems is realized by introducing equivalent source terms in each equation set. A weighted electric field obtained from the 3D discretization around the wire is introduced as a voltage source in the telegrapher equations. A volume current density obtained from the 1D discretization on the wire is introduced as a current source in the Ampere law equation. © 2015 IEEE.

  3. TOPICAL REVIEW: Modelling the interaction of electromagnetic fields (10 MHz 10 GHz) with the human body: methods and applications

    Science.gov (United States)

    Hand, J. W.

    2008-08-01

    Numerical modelling of the interaction between electromagnetic fields (EMFs) and the dielectrically inhomogeneous human body provides a unique way of assessing the resulting spatial distributions of internal electric fields, currents and rate of energy deposition. Knowledge of these parameters is of importance in understanding such interactions and is a prerequisite when assessing EMF exposure or when assessing or optimizing therapeutic or diagnostic medical applications that employ EMFs. In this review, computational methods that provide this information through full time-dependent solutions of Maxwell's equations are summarized briefly. This is followed by an overview of safety- and medical-related applications where modelling has contributed significantly to development and understanding of the techniques involved. In particular, applications in the areas of mobile communications, magnetic resonance imaging, hyperthermal therapy and microwave radiometry are highlighted. Finally, examples of modelling the potentially new medical applications of recent technologies such as ultra-wideband microwaves are discussed.

  4. The Electromagnetic Conception of Nature at the Root of the Special and General Relativity Theories and Its Revolutionary Meaning

    Science.gov (United States)

    Giannetto, Enrico R. A.

    2009-01-01

    The revolution in XX century physics, induced by relativity theories, had its roots within the electromagnetic conception of Nature. It was developed through a tradition related to Brunian and Leibnizian physics, to the German "Naturphilosophie" and English XIXth physics. The electromagnetic conception of Nature was in some way realized by the…

  5. Chaotic behavior in a relativistic electron beam interacting with a transverse slow electromagnetic wave

    International Nuclear Information System (INIS)

    Serbeto, A.; Alves, M.V.

    1993-01-01

    Using a nonlinear set of equations which describes the excitation of a purely transverse slow electromagnetic wave by a relativistic electron beam, it is shown that the system runs from chaotic behavior to a regular stable state due to crisis phenomenon and from stabilized soliton and repeated stabilized explosive solutions to a temporal chaos. These behaviors suggest that the primary mechanism for the saturation of the explosive instability is not only the cubic nonlinear frequency shift as pointed out by many authors until now. The inclusion of the velocity perturbation in the beam charge initial equilibrium state leads the system to these strange behaviors. (author)

  6. Final Scientific Report - Electromagnetic Interactions in Self-Assembled Metallo-Dielectric Biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Dragnea, Bogdan G. [Indiana Univ., Bloomington, IN (United States)

    2017-05-03

    Achievements which resulted from previous DOE funding include: templated virus-like particle assembly thermodynamics, development of single particle photothermal absorption spectroscopy and dark- field spectroscopy instrumentation for the measurement of optical properties of virus-like nanoparticles, electromagnetic simulations of coupled nanoparticle cluster systems, virus contact mechanics, energy transfer and fluorescence quenching in multichromophore systems supported on biomolecular templates, and photo physical work on virus-aptamer systems. A current total of eight published research articles and a book chapter are acknowledging DOE support for the period 2013-2016.

  7. Resonant interaction of electromagnetic wave with plasma layer and overcoming the radiocommunication blackout problem

    Science.gov (United States)

    Bogatskaya, A. V.; Klenov, N. V.; Tereshonok, M. V.; Adjemov, S. S.; Popov, A. M.

    2018-05-01

    We present an analysis of the possibility of penetrating electromagnetic waves through opaque media using an optical-mechanical analogy. As an example, we consider the plasma sheath surrounding the vehicle as a potential barrier and analyze the overcoming of radiocommunication blackout problem. The idea is to embed a «resonator» between the surface on the vehicle and plasma sheath which is supposed to provide an effective tunneling of the signal to the receiving antenna. We discuss the peculiarities of optical mechanical analogy applicability and analyze the radio frequency wave tunneling regime in detail. The cases of normal and oblique incidence of radiofrequency waves on the vehicle surface are studied.

  8. Edge corrections to electromagnetic Casimir energies from general-purpose Mathieu-function routines

    Science.gov (United States)

    Blose, Elizabeth Noelle; Ghimire, Biswash; Graham, Noah; Stratton-Smith, Jeremy

    2015-01-01

    Scattering theory methods make it possible to calculate the Casimir energy of a perfectly conducting elliptic cylinder opposite a perfectly conducting plane in terms of Mathieu functions. In the limit of zero radius, the elliptic cylinder becomes a finite-width strip, which allows for the study of edge effects. However, existing packages for computing Mathieu functions are insufficient for this calculation because none can compute Mathieu functions of both the first and second kind for complex arguments. To address this shortcoming, we have written a general-purpose Mathieu-function package, based on algorithms developed by Alhargan. We use these routines to find edge corrections to the proximity force approximation for the Casimir energy of a perfectly conducting strip opposite a perfectly conducting plane.

  9. Application of a generalized Leibniz rule for calculating electromagnetic fields within continuous source regions

    International Nuclear Information System (INIS)

    Silberstein, M.

    1991-01-01

    In deriving the electric and magnetic fields in a continuous source region by differentiating the vector potential, Yaghjian (1985) explains that the central obstacle is the dependence of the integration limits on the differentiation variable. Since it is not mathematically rigorous to assume the curl and integral signs are interchangeable, he uses an integration variable substitution to circumvent this problematic dependence. Here, an alternative derivation is presented, which evaluates the curl of the vector potential volume integral directly, retaining the dependence of the limits of integration on the differentiation variable. It involves deriving a three-dimensional version of Leibniz' rule for differentiating an integral with variable limits of integration, and using the generalized rule to find the Maxwellian and cavity fields in the source region. 7 refs

  10. Lagrange formalism for a system of several fluids interacting electromagnetically; Formalisme lagrangien pour un systeme de plusieurs fluides en interaction electromagnetique

    Energy Technology Data Exchange (ETDEWEB)

    Vuillemin, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    After giving the Lagrange expression for a conducting fluid in an external electromagnetic field, the author shows that a Lagrange expression exists for describing the evolution of a system of interacting fluids obtained by adding the Lagrange expression of each fluid.to that of the electromagnetic field. By variation are obtained the fluid movement equation coupled to the Maxwell equations. It is shown that the study of small movements around a stationary state can be deduced from the Lagrange equation expanded to the second power order of the perturbation. It is then possible to deduce the normal mode equations and the study the stability by examining the modes which are marginally stable. (author) [French] Apres avoir rappele l'expression, du Lagrangien pour un fluide conducteur dans un champ electromagnetique exterieur, on montre qu'il existe un Lagrangien pour decrire l'evolution d'un systeme de fluides en.interaction que l'on obtient par la superposition du Lagrangien de chaque fluide et du Lagrangien du champ electromagnetique. On obtient par variation, les equations du mouvement des fluides, couplees aux equations de Maxwell. On montre que l'etude des petits mouvements autour d'un etat stationnaire se deduit du Lagrangien developpe au second1 ordre en puissance de la perturbation. On peut alors retrouver les equations des modes normaux et etudier la stabilite en recherchant les modes marginalement stables. (auteur)

  11. Investigations of the structure and electromagnetic interactions of few-body systems. Progress report, September 1, 1983-August 31, 1984

    International Nuclear Information System (INIS)

    Harper, E.P.; Lehman, D.R.; Prats, F.

    1984-01-01

    The George Washington University nuclear theory group proposes to conduct investigations of the structure and electromagnetic interactions of few-body systems. The structural properties of the very light nuclei are examined by developing theoretical models that begin from the basic interactions between the constituents and that are solved exactly (numerically), i.e., full three or four-body dynamics. Such models are then used in an attempt to understand the details of the strong and electromagnetic interactions of the few-nucleon nuclei after the basic underlying reaction mechanisms are understood with simpler models. Examples of specific work proposed are the following: (1) From exact four-body dynamics, derive the equations that will permit calculation of the 4 He→ 3 He+n and 4 He→d+d asymptotic normalization constants; (2) Develop a unified picture of the p + d → 3 He = γ, p + d → 3 He = π 0 , p + d → 3 H + π + reactions at intermediate energies; (3) Calculate the elastic and inelastic (1 + →0 + ) form factors for 6 Li with three-body (αNN) wave functions; (4) Calculate static properties (RMS radius, magnetic moment, and quadrupole moment) of 6 Li with three-body wave functions; and (5) Develop the theory for the coincidence reactions 6 Li(p,2p)nα, 6 Li(e,e'p)nα, and 6 Li(e,e'd)α. It is anticipated that these efforts will expand the frontiers of our knowledge about few-body nuclei

  12. One-step leapfrog ADI-FDTD method for simulating electromagnetic wave propagation in general dispersive media.

    Science.gov (United States)

    Wang, Xiang-Hua; Yin, Wen-Yan; Chen, Zhi Zhang David

    2013-09-09

    The one-step leapfrog alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method is reformulated for simulating general electrically dispersive media. It models material dispersive properties with equivalent polarization currents. These currents are then solved with the auxiliary differential equation (ADE) and then incorporated into the one-step leapfrog ADI-FDTD method. The final equations are presented in the form similar to that of the conventional FDTD method but with second-order perturbation. The adapted method is then applied to characterize (a) electromagnetic wave propagation in a rectangular waveguide loaded with a magnetized plasma slab, (b) transmission coefficient of a plane wave normally incident on a monolayer graphene sheet biased by a magnetostatic field, and (c) surface plasmon polaritons (SPPs) propagation along a monolayer graphene sheet biased by an electrostatic field. The numerical results verify the stability, accuracy and computational efficiency of the proposed one-step leapfrog ADI-FDTD algorithm in comparison with analytical results and the results obtained with the other methods.

  13. Mapping of radio frequency electromagnetic field exposure levels in outdoor environment and comparing with reference levels for general public health.

    Science.gov (United States)

    Cansiz, Mustafa; Abbasov, Teymuraz; Kurt, M Bahattin; Celik, A Recai

    2018-03-01

    In this study, radio frequency electromagnetic field exposure levels were measured on the main streets in the city center of Diyarbakır, Turkey. Measured electric field levels were plotted on satellite imagery of Diyarbakır and were compared with exposure guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Exposure measurements were performed in dense urban, urban and suburban areas each day for 7 consecutive days. The measurement system consisted of high precision and portable spectrum analyzer, three-axis electric field antenna, connection cable and a laptop which was used to record the measurement samples as a data logger. The highest exposure levels were detected for two places, which are called Diclekent and Batıkent. It was observed that the highest instantaneous electric field strength value for Batıkent was 7.18 V/m and for Diclekent was 5.81 V/m. It was statistically determined that the main contributor band to the total exposure levels was Universal Mobile Telecommunications System band. Finally, it was concluded that all measured exposure levels were lower than the reference levels recommended by ICNIRP for general public health.

  14. Anticipated Impact of In-Car Mobile Calls on the Electromagnetic Interaction of Handset Antenna and Human

    Directory of Open Access Journals (Sweden)

    Salah I. Yahya

    2014-09-01

    Full Text Available This paper investigates the impact of the in-car mobile call on the electromagnetic interaction of the mobile handset antenna and user’s head. This impact was evaluated from two different perspectives; First, the antenna performance, e.g., total isotropic sensitivity and total efficiency, and second, the specific absorption rate (SAR induced in the user's head. A Yee-FDTD based electromagnetic solver was used to simulate a mobile phone in hand close proximity to head at cheek and tilt positions, and working at a frequency of 1900 MHz (GSM 1900/PCS while making a call inside a car. A Specific Anthropomorphic Mannequin (SAM was used to simulate the user’s head, a generic phone was used to simulate the mobile phone, a semi-realistic model with three tissues, i.e., skin, bone and muscle, was used to simulate the user’s hand, and a CAD model of Ferrari F430-brand was used to simulate the car. The results showed a considerable degradation in the mobile phone antenna performance while making a mobile phone call inside a car that may drive the mobile phone increases its radiated power to establish a successful connection with the base-station antenna, and consequently increases the induced specific absorption rate in the user’s head.

  15. Pulse interactions in a quantum dot waveguide in the regime of electromagnetically Induced transparency

    DEFF Research Database (Denmark)

    Nielsen, Per; Nielsen, Henri; Mørk, Jesper

    2006-01-01

    The interaction of optical pulses in a quantum dot waveguide in the slow-light regime is investigated. Dipole oscillations lead to strong interactions between the two pulses, implying a minimum pulse separation for optical buffer applications.......The interaction of optical pulses in a quantum dot waveguide in the slow-light regime is investigated. Dipole oscillations lead to strong interactions between the two pulses, implying a minimum pulse separation for optical buffer applications....

  16. Electromagnetic corrections to baryon masses

    International Nuclear Information System (INIS)

    Durand, Loyal; Ha, Phuoc

    2005-01-01

    We analyze the electromagnetic contributions to the octet and decuplet baryon masses using the heavy-baryon approximation in chiral effective field theory and methods we developed in earlier analyses of the baryon masses and magnetic moments. Our methods connect simply to Morpurgo's general parametrization of the electromagnetic contributions and to semirelativistic quark models. Our calculations are carried out including the one-loop mesonic corrections to the basic electromagnetic interactions, so to two loops overall. We find that to this order in the chiral loop expansion there are no three-body contributions. The Coleman-Glashow relation and other sum rules derived in quark models with only two-body terms therefore continue to hold, and violations involve at least three-loop processes and can be expected to be quite small. We present the complete formal results and some estimates of the matrix elements here. Numerical calculations will be presented separately

  17. Piezoelectricity and prostate cancer: proposed interaction between electromagnetic field and prostatic crystalloids.

    Science.gov (United States)

    Ghabili, Kamyar; Shoja, Mohammadali M; Agutter, Paul S

    2008-06-01

    There is evidence that electromagnetic fields (EMF) play some part in the pathogenesis of prostate cancer, but the pathogenic mechanism remains unknown. The normal prostate gland and both benign and malignant prostate lesions contain abundant calcium/phosphorus crystalloids with various morphologies, which seem to be heterogeneously and diffusely distributed within the gland. We hypothesize that an environmental EMF may result in simultaneous, multidirectional and diffuse compression or expansion of these crystalloids (a piezoelectric effect). This would result in a slight mechanical distortion of the prostate, potentially altering cell behavior and enhancing the expression of specific genes, particularly those involved in suppressing apoptosis. A mathematical model of the cell mechanical effect is presented, and the hypothesis is related to current clinical evidence and to potential validation by critical laboratory tests.

  18. Electromagnetic pulse (EMP) radiation by laser interaction with a solid H.sub.2./sub. ribbon

    Czech Academy of Sciences Publication Activity Database

    De Marco, Massimo; Krása, Josef; Cikhardt, J.; Velyhan, Andriy; Pfeifer, Miroslav; Dudžák, Roman; Dostál, Jan; Krouský, Eduard; Limpouch, J.; Pisarczyk, T.; Kalinowska, Z.; Chodukowski, T.; Ullschmied, Jiří; Giuffrida, Lorenzo; Chatain, D.; Perin, J.P.; Margarone, Daniele

    2017-01-01

    Roč. 24, č. 8 (2017), s. 1-6, č. článku 083103. ISSN 1070-664X R&D Projects: GA MŠk EF15_008/0000162; GA ČR GA16-07036S; GA MŠk(CZ) LD14089; GA MŠk LQ1606 EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser-produced plasma * electromagnetic pulse * solid hydrogen ribbon Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.115, year: 2016

  19. Interaction of intense electromagnetic fields with SF6 molecules and clusters in supersonic expansion

    International Nuclear Information System (INIS)

    Airoldi, V.J.T.

    1987-01-01

    A method of measuring SF 6 cluster formation and inhibition in pulsed supersonic expansion in the presence of intense electromagnetic radiation is presented. The characterization of the expansion of SF 6 molecules was done and, the extension of the collision region was determined. An improved unidimensional theory of supersonic expansion showed good agreement with the experimental results. The spectra of multiphoton absorption of SF 6 molecules in supersonic jet and the average energy absorved by each molecule were determined. The absorption spectra of molecule in the collision region present absorption maxima different from those obtained in the collisionless region. The results, if compared with the literature data, show good agreement, with a small difference in the spetra corresponding to the collisionless region. This difference was observed, for the first time in the multiphoton absorption and is attribuited to cluster formation in the jet. A new technique for measuring cluster formation in the supersonic jet, based on determination of the spatial distribution of the energy of molecules in the jet after passing through a skimmer located in the collision region is shown. The inhibition of cluster formation, due to the incidence of intense electromagnetic radiation from a CO 2 -TEA pulsed laser in the initial collision region of the jet, causes a second expansion in the skimmer. The results obtained show that this method can lead to a new isotope separation process. All the parts of the experimental set up, for example, high vacuum system, pulsed valve and pyroelectric detector, were developed and constructed specially for the experiment. (Author) [pt

  20. Generalized Functional Linear Models With Semiparametric Single-Index Interactions

    KAUST Repository

    Li, Yehua

    2010-06-01

    We introduce a new class of functional generalized linear models, where the response is a scalar and some of the covariates are functional. We assume that the response depends on multiple covariates, a finite number of latent features in the functional predictor, and interaction between the two. To achieve parsimony, the interaction between the multiple covariates and the functional predictor is modeled semiparametrically with a single-index structure. We propose a two step estimation procedure based on local estimating equations, and investigate two situations: (a) when the basis functions are pre-determined, e.g., Fourier or wavelet basis functions and the functional features of interest are known; and (b) when the basis functions are data driven, such as with functional principal components. Asymptotic properties are developed. Notably, we show that when the functional features are data driven, the parameter estimates have an increased asymptotic variance, due to the estimation error of the basis functions. Our methods are illustrated with a simulation study and applied to an empirical data set, where a previously unknown interaction is detected. Technical proofs of our theoretical results are provided in the online supplemental materials.

  1. Generalized Functional Linear Models With Semiparametric Single-Index Interactions

    KAUST Repository

    Li, Yehua; Wang, Naisyin; Carroll, Raymond J.

    2010-01-01

    We introduce a new class of functional generalized linear models, where the response is a scalar and some of the covariates are functional. We assume that the response depends on multiple covariates, a finite number of latent features in the functional predictor, and interaction between the two. To achieve parsimony, the interaction between the multiple covariates and the functional predictor is modeled semiparametrically with a single-index structure. We propose a two step estimation procedure based on local estimating equations, and investigate two situations: (a) when the basis functions are pre-determined, e.g., Fourier or wavelet basis functions and the functional features of interest are known; and (b) when the basis functions are data driven, such as with functional principal components. Asymptotic properties are developed. Notably, we show that when the functional features are data driven, the parameter estimates have an increased asymptotic variance, due to the estimation error of the basis functions. Our methods are illustrated with a simulation study and applied to an empirical data set, where a previously unknown interaction is detected. Technical proofs of our theoretical results are provided in the online supplemental materials.

  2. General approach to polymer chains confined by interacting boundaries.

    Science.gov (United States)

    Freed, Karl F; Dudowicz, Jacek; Stukalin, Evgeny B; Douglas, Jack F

    2010-09-07

    Polymer chains, confined to cavities or polymer layers with dimensions less than the chain radius of gyration, appear in many phenomena, such as gel chromatography, rubber elasticity, viscolelasticity of high molar mass polymer melts, the translocation of polymers through nanopores and nanotubes, polymer adsorption, etc. Thus, the description of how the constraints alter polymer thermodynamic properties is a recurrent theoretical problem. A realistic treatment requires the incorporation of impenetrable interacting (attractive or repulsive) boundaries, a process that introduces significant mathematical complications. The standard approach involves developing the generalized diffusion equation description of the interaction of flexible polymers with impenetrable confining surfaces into a discrete eigenfunction expansion, where the solutions are normally truncated at the first mode (the "ground state dominance" approximation). This approximation is mathematically well justified under conditions of strong confinement, i.e., a confinement length scale much smaller than the chain radius of gyration, but becomes unreliable when the polymers are confined to dimensions comparable to their typically nanoscale size. We extend a general approach to describe polymers under conditions of weak to moderate confinement and apply this semianalytic method specifically to determine the thermodynamics and static structure factor for a flexible polymer confined between impenetrable interacting parallel plate boundaries. The method is first illustrated by analyzing chain partitioning between a pore and a large external reservoir, a model system with application to chromatography. Improved agreement is found for the partition coefficients of a polymer chain in the pore geometry. An expression is derived for the structure factor S(k) in a slit geometry to assist in more accurately estimating chain dimensions from scattering measurements for thin polymer films.

  3. Transient analysis of electromagnetic wave interactions on high-contrast scatterers using volume electric field integral equation

    KAUST Repository

    Sayed, Sadeed Bin

    2014-07-01

    A marching on-in-time (MOT)-based time domain volume electric field integral equation (TD-VEFIE) solver is proposed for accurate and stable analysis of electromagnetic wave interactions on high-contrast scatterers. The stability is achieved using band-limited but two-sided (non-causal) temporal interpolation functions and an extrapolation scheme to cast the time marching into a causal form. The extrapolation scheme is designed to be highly accurate for oscillating and exponentially decaying fields, hence it accurately captures the physical behavior of the resonant modes that are excited inside the dielectric scatterer. Numerical results demonstrate that the resulting MOT scheme maintains its stability as the number of resonant modes increases with the contrast of the scatterer.

  4. Dynamic evolution of double Λ five-level atom interacting with one-mode electromagnetic cavity field

    Science.gov (United States)

    Abdel-Wahab, N. H.; Salah, Ahmed

    2017-12-01

    In this paper, the model describing a double Λ five-level atom interacting with a single mode electromagnetic cavity field in the (off) non-resonate case is studied. We obtained the constants of motion for the considered model. Also, the state vector of the wave function is given by using the Schrödinger equation when the atom is initially prepared in its excited state. The dynamical evolutions for the collapse revivals, the antibunching of photons and the field squeezing phenomena are investigated when the field is considered in a coherent state. The influence of detuning parameters on these phenomena is investigated. We noticed that the atom-field properties are influenced by changing the detuning parameters. The investigation of these aspects by numerical simulations is carried out using the Quantum Toolbox in Python (QuTip).

  5. Confinement and hadron-hadron interactions by general relativistic methods

    Science.gov (United States)

    Recami, Erasmo

    By postulating covariance of physical laws under global dilations, one can describe gravitational and strong interactions in a unified way. Namely, in terms of the new discrete dilational degree of freedom, our cosmos and hadrons can be regarded as finite, similar systems. And a discrete hierarchy of finite ``universes'' may be defined, which are governed by fields with strengths inversally proportional to their radii; in each universe an Equivalence Principle holds, so that the relevant field can be there geometrized. Scaled-down Einstein equations -with cosmological term- are assumed to hold inside hadrons (= strong micro-cosmoses); and they yield in a natural way classical confinement, as well as ``asymptotic freedom'', of the hadron constituents. In other words, the association of strong micro-universes of Friedmann type with hadrons (i.e., applying the methods of General Relativity to subnuclear particle physics) allows avoiding recourse to phenomenological models such as the Bag Model. Inside hadrons we have to deal with a tensorial field (= strong gravity), and hadron constituents are supposed to exchange spin-2 ``gluons''. Our approach allows us also to write down a tensorial, bi-scale field theory of hadron-hadron interactions, based on modified Einstein-type equations here proposed for strong interactions in our space. We obtain in particular: (i) the correct Yukawa behaviour of the strong scalar potential at the static limit and for r>~l fm; (ii) the value of hadron radii. As a byproduct, we derive a whole ``numerology'', connecting our gravitational cosmos with the strong micro-cosmoses (hadrons), such that it does imply no variation of G with the epoch. Finally, since a structute of the ``micro-universe'' type seems to be characteristic even of leptons, a hope for the future is including also weak interactions in our classical unification of the fundamental forces.

  6. Geometrization of the electromagnetic field and dark matter

    International Nuclear Information System (INIS)

    Pestov, I.B.

    2005-01-01

    A general concept of potential field is introduced. The potential field that one puts in correspondence with dark matter, has fundamental geometrical interpretation (parallel transport) and has intrinsically inherent local symmetry. The equations of dark matter field are derived that are invariant with respect to the local transformations. It is shown how to reduce these equations to the Maxwell equations. Thus, the dark matter field may be considered as generalized electromagnetic field and a simple solution of the old problem is given to connect electromagnetic field with geometrical properties of the physical manifold itself. It is shown that gauge fixing renders generalized electromagnetic field effectively massive while the Maxwell electromagnetic field remains massless. To learn more about interactions between matter and dark matter on the microscopical level (and to recognize the fundamental role of internal symmetry) the general covariant Dirac equation is derived in the Minkowski space-time which describes the interactions of spinor field with dark matter field

  7. Effect of magnetic field on nonlinear interactions of electromagnetic and surface waves in a plasma layer

    International Nuclear Information System (INIS)

    Khalil, Sh.M.; El-Sherif, N.; El-Siragy, N.M.; Tanta Univ.; El-Naggar, I.A.; Alexandria Univ.

    1985-01-01

    Investigation is made for nonlinear interaction between incident radiation and a surface wave in a magnetized plasma layer. Both interacting waves are of P polarization. The generated currents and fields at combination frequencies are obtained analytically. Unlike the S-polarized interacting waves, the magnetic field affects the fundamental waves and leads to an amplification of generated waves when their frequencies approach the cyclotron frequency. (author)

  8. Electromagnetic properties for arbitrary spin particles: Natural electromagnetic moments from light-cone arguments

    International Nuclear Information System (INIS)

    Lorce, Cedric

    2009-01-01

    We revisit the old-standing problem of the electromagnetic interaction for particles of arbitrary spin. Based on the assumption that light-cone helicity at tree level and Q 2 =0 should be conserved nontrivially by the electromagnetic interaction, we are able to derive all the natural electromagnetic moments for a pointlike particle of any spin. We provide here a transparent decomposition of the electromagnetic current in terms of covariant vertex functions. We also define in a general way the electromagnetic multipole form factors, and show their relation with the electromagnetic moments and covariant vertex functions. The light-cone helicity conservation argument determines uniquely the values of all electromagnetic moments, which we refer to as the 'natural' ones. These specific values are in accordance with the standard model, and the prediction of universal g=2 gyromagnetic factor is naturally recovered. We provide a very simple and compact formula for these natural moments. As an application of our results, we generalize the discussion of quark transverse charge densities to particles with arbitrary spin, giving more physical support to the light-cone helicity conservation argument.

  9. Stark interaction of identical particles with the vacuum electromagnetic field as quantum Poisson process suppressing collective spontaneous emission

    International Nuclear Information System (INIS)

    Basharov, A. M.

    2011-01-01

    The effective Hamiltonian describing resonant interaction of an ensemble of identical quantum particles with a photon-free vacuum electromagnetic field has been obtained with allowance for terms of second order in the coupling constant (the Stark interaction) by means of the perturbation theory on the basis of the unitary transformation of the system quantum state. It has been shown that in the Markov approximation the effective Hamiltonian terms of first order in the coupling constant are represented by the quantum Wiener process, whereas terms of second order are expressed by the quantum Poisson process. During the course of the investigation, it was established that the Stark interaction played a significant role in the ensemble dynamics, thus influencing the collective spontaneous decay of the ensemble of an appreciably high number of identical particles. Fundamental effects have been discovered, i.e., the excitation conservation in a sufficiently dense ensemble of identical particles and superradiance suppression in the collective decaying process of an excited ensemble with a determined number of particles.

  10. Electromagnetically induced transparency in the case of elliptic polarization of interacting fields

    Science.gov (United States)

    Parshkov, Oleg M.

    2018-04-01

    The theoretical investigation results of disintegration effect of elliptic polarized shot probe pulses of electromagnetically induced transparency in the counterintuitive superposed elliptic polarized control field and in weak probe field approximation are presented. It is shown that this disintegration occurs because the probe field in the medium is the sum of two normal modes, which correspond to elliptic polarized pulses with different speeds of propagation. The polarization ellipses of normal modes have equal eccentricities and mutually perpendicular major axes. Major axis of polarization ellipse of one normal mode is parallel to polarization ellipse major axis of control field, and electric vector of this mode rotates in the opposite direction, than electric vector of the control field. The electric vector other normal mode rotates in the same direction that the control field electric vector. The normal mode speed of the first type aforementioned is less than that of the second type. The polarization characteristics of the normal mode depend uniquely on the polarization characteristics of elliptic polarized control field and remain changeless in the propagation process. The theoretical investigation is performed for Λ-scheme of degenerated quantum transitions between 3P0, 3P10 and 3P2 energy levels of 208Pb isotope.

  11. The interaction of an electromagnetic wave with an inhomogeneous plasma slab

    International Nuclear Information System (INIS)

    Lacina, J.; Preinhaelter, J.

    1982-07-01

    In connection with the problem of plasma heating by high-frequency waves a numerical code was developed which makes it possible to study the incidence of an electromagnetic wave on an inhomogeneous plasma slab. Using a one-dimensional model, non-magnetized plasma is described by means of two-fluid equations with finite electron pressure and with the adiabatic condition for all processes. It is shown that at normal incidence of a wave on a cold plasma, the wave is reflected from the region of plasma resonance. A standing wave arises which generates an electrostatic standing wave of a double frequency. At the same time the density gradient sharply rises in this region. In a warm plasma the incident wave again creates a standing wave but nonlinear perturbations propagate from the region of plasma resonance at ion acoustic velocity to the whole plasma volume. In this case the density gradient does not change very much. In the region of plasma resonance ion acoustic waves are also generated. (author)

  12. Electromagnetic interaction between a rising spherical particle in a conducting liquid and a localized magnetic field

    Science.gov (United States)

    Lyu, Z.; Tran, N.; Boeck, T.; Karcher, C.

    2017-07-01

    Lorentz force velocimetry (LFV) is a non-contact electromagnetic flow measurement technique for electrically conductive liquids. It is based on measuring the flow-induced force acting on an external permanent magnet. Motivated by extending LFV to liquid metal two-phase flow measurement, in a first test we consider the free rising of a non-conductive spherical particle in a thin tube of liquid metal (GaInSn) initially at rest. Here the measured force is due to the displacement flow induced by the rising particle. In this paper, numerical results are presented for three different analytical solutions of flows around a moving sphere under a localized magnetic field. This simplification is made since the hydrodynamic flow is difficult to measure or to compute. The Lorentz forces are compared to experiments. The aim of the present work is to check if our simple numerical model can provide Lorentz forces comparable to the experiments. The results show that the peak values of the Lorentz force from the analytical velocity fields provide us an upper limit to the measurement results. In the case of viscous flow around a moving sphere we recover the typical time-scale of Lorentz force signals.

  13. Review on Computational Electromagnetics

    Directory of Open Access Journals (Sweden)

    P. Sumithra

    2017-03-01

    Full Text Available Computational electromagnetics (CEM is applied to model the interaction of electromagnetic fields with the objects like antenna, waveguides, aircraft and their environment using Maxwell equations.  In this paper the strength and weakness of various computational electromagnetic techniques are discussed. Performance of various techniques in terms accuracy, memory and computational time for application specific tasks such as modeling RCS (Radar cross section, space applications, thin wires, antenna arrays are presented in this paper.

  14. Effect of nonlinearity of spin interaction with electromagnetic resonance field on characteristics of polarized nuclear target

    International Nuclear Information System (INIS)

    Vertij, A.A.; Gavrilov, S.P.; Shestopalov, V.P.

    1990-01-01

    Interaction of incident nuclear particle beam with J = 1/2 (neutrons) spin and (J = 1/2) protons with the target substance is considered. It is shown that neutron polarization at the target exit and neutron transparency (G) of the target depend significantly on incident wave amplitude level and physical parameter values which characterize the target, such as target temperature, resonator mirror reflection factor, number of spins interacting with the field, etc. Under interaction of neutrons with a target resonator which features a high mirror reflection factor and low losses for absorption which is not related to magnetic dipole absorption, a bistable response of neutron polarization and G manifests itself. 1 ref

  15. Electromagnetic fields created by a beam in an axisymmetric infinitely thick single-layer resistive pipe: general formulas and low frequency approximations

    CERN Document Server

    Mounet, Nicolas Frank; CERN. Geneva. ATS Department

    2015-01-01

    This note provides general and approximate formulas for the electromagnetic fields created by a passing beam in an axisymmetric infinitely thick resistive pipe made of a single homogeneous layer. The full derivations and their resulting approximate expressions at low and intermediate frequencies are given here, as well as the conditions under which those approximations are valid. Beam-coupling impedances are also computed, and examples are shown.

  16. Biological General Repository for Interaction Datasets (BioGRID)

    Data.gov (United States)

    U.S. Department of Health & Human Services — BioGRID is an online interaction repository with data on raw protein and genetic interactions from major model organism species. All interaction data are freely...

  17. General relativity and dark matter

    International Nuclear Information System (INIS)

    Pestov, A.B.

    1993-01-01

    It is shown that from the first principles of General Relativity it follows that there exists a new type of interactions which are tightly connected with the gravitational interactions. New particles representing a new form of interactions do not interact electromagnetically, strongly and weakly with the known elementary particles. Physics of the new particles is defined by the Planck scales. (author.). 9 refs

  18. Thermal mapping on male genital and skin tissues of laptop thermal sources and electromagnetic interaction.

    Science.gov (United States)

    Safari, Mahdi; Mosleminiya, Navid; Abdolali, Ali

    2017-10-01

    Since the development of communication devices and expansion of their applications, there have been concerns about their harmful health effects. The main aim of this study was to investigate laptop thermal effects caused by exposure to electromagnetic fields and thermal sources simultaneously; propose a nondestructive, replicable process that is less expensive than clinical measurements; and to study the effects of positioning any new device near the human body in steady state conditions to ensure safety by U.S. and European standard thresholds. A computer simulation was designed to obtain laptop heat flux from SolidWorks flow simulation. Increase in body temperature due to heat flux was calculated, and antenna radiation was calculated using Computer Simulation Technology (CST) Microwave Studio software. Steady state temperature and specific absorption rate (SAR) distribution in user's body, and heat flux beneath the laptop, were obtained from simulations. The laptop in its high performance mode caused 420 (W/m 2 ) peak two-dimensional heat flux beneath it. The cumulative effect of laptop in high performance mode and 1 W antenna radiation resulted in temperatures of 42.9, 38.1, and 37.2 °C in lap skin, scrotum, and testis, that is, 5.6, 2.1, and 1.4 °C increase in temperature, respectively. Also, 1 W antenna radiation caused 0.37 × 10 -3 and 0.13 × 10 -1 (W/kg) peak three-dimensional SAR at 2.4 and 5 GHz, respectively, which could be ignored in reference to standards and temperature rise due to laptop use. Bioelectromagnetics. 38:550-558, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. A Unified Field Theory of Gravity, Electromagnetism, and theA Unified Field Theory of Gravity, Electromagnetism, and the Yang-Mills Gauge Field

    Directory of Open Access Journals (Sweden)

    Suhendro I.

    2008-01-01

    Full Text Available In this work, we attempt at constructing a comprehensive four-dimensional unified field theory of gravity, electromagnetism, and the non-Abelian Yang-Mills gauge field in which the gravitational, electromagnetic, and material spin fields are unified as intrinsic geometric objects of the space-time manifold $S_4$ via the connection, with the generalized non-Abelian Yang-Mills gauge field appearing in particular as a sub-field of the geometrized electromagnetic interaction.

  20. Engineering Electromagnetics

    International Nuclear Information System (INIS)

    Kim, Se Yun

    2009-01-01

    This book deals with engineering electromagnetics. It contains seven chapters, which treats understanding of engineering electromagnetics such as magnet and electron spin, current and a magnetic field and an electromagnetic wave, Essential tool for engineering electromagnetics on rector and scalar, rectangular coordinate system and curl vector, electrostatic field with coulomb rule and method of electric images, Biot-Savart law, Ampere law and magnetic force, Maxwell equation and an electromagnetic wave and reflection and penetration of electromagnetic plane wave.

  1. Plasma parameters and electromagnetic forces induced by the magneto hydro dynamic interaction in a hypersonic argon flow experiment

    International Nuclear Information System (INIS)

    Cristofolini, Andrea; Neretti, Gabriele; Borghi, Carlo A.

    2012-01-01

    This work proposes an experimental analysis on the magneto hydro dynamic (MHD) interaction induced by a magnetic test body immersed into a hypersonic argon flow. The characteristic plasma parameters are measured. They are related to the voltages arising in the Hall direction and to the variation of the fluid dynamic properties induced by the interaction. The tests have been performed in a hypersonic wind tunnel at Mach 6 and Mach 15. The plasma parameters are measured in the stagnation region in front of the nozzle of the wind tunnel and in the free stream region at the nozzle exit. The test body has a conical shape with the cone axis in the gas flow direction and the cone vertex against the flow. It is placed at the nozzle exit and is equipped with three permanent magnets. In the configuration adopted, the Faraday current flows in a closed loop completely immersed into the plasma of the shock layer. The electric field and the pressure variation due to MHD interaction have been measured on the test body walls. Microwave adsorption measurements have been used for the determination of the electron number density and the electron collision frequency. Continuum recombination radiation and line radiation emissions have been detected. The electron temperature has been determined by means of the spectroscopic data by using different methods. The electron number density has been also determined by means of the Stark broadening of H α and the H β lines. Optical imaging has been utilized to visualize the pattern of the electric current distribution in the shock layer around the test body. The experiments show a considerable effect of the electromagnetic forces produced by the MHD interaction acting on the plasma flow around the test body. A comparison of the experimental data with simulation results shows a good agreement.

  2. Lie algebraic approach to the time-dependent quantum general harmonic oscillator and the bi-dimensional charged particle in time-dependent electromagnetic fields

    International Nuclear Information System (INIS)

    Ibarra-Sierra, V.G.; Sandoval-Santana, J.C.; Cardoso, J.L.; Kunold, A.

    2015-01-01

    We discuss the one-dimensional, time-dependent general quadratic Hamiltonian and the bi-dimensional charged particle in time-dependent electromagnetic fields through the Lie algebraic approach. Such method consists in finding a set of generators that form a closed Lie algebra in terms of which it is possible to express a quantum Hamiltonian and therefore the evolution operator. The evolution operator is then the starting point to obtain the propagator as well as the explicit form of the Heisenberg picture position and momentum operators. First, the set of generators forming a closed Lie algebra is identified for the general quadratic Hamiltonian. This algebra is later extended to study the Hamiltonian of a charged particle in electromagnetic fields exploiting the similarities between the terms of these two Hamiltonians. These results are applied to the solution of five different examples: the linear potential which is used to introduce the Lie algebraic method, a radio frequency ion trap, a Kanai–Caldirola-like forced harmonic oscillator, a charged particle in a time dependent magnetic field, and a charged particle in constant magnetic field and oscillating electric field. In particular we present exact analytical expressions that are fitting for the study of a rotating quadrupole field ion trap and magneto-transport in two-dimensional semiconductor heterostructures illuminated by microwave radiation. In these examples we show that this powerful method is suitable to treat quadratic Hamiltonians with time dependent coefficients quite efficiently yielding closed analytical expressions for the propagator and the Heisenberg picture position and momentum operators. -- Highlights: •We deal with the general quadratic Hamiltonian and a particle in electromagnetic fields. •The evolution operator is worked out through the Lie algebraic approach. •We also obtain the propagator and Heisenberg picture position and momentum operators. •Analytical expressions for a

  3. Lie algebraic approach to the time-dependent quantum general harmonic oscillator and the bi-dimensional charged particle in time-dependent electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra-Sierra, V.G.; Sandoval-Santana, J.C. [Departamento de Física, Universidad Autónoma Metropolitana Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 México D.F. (Mexico); Cardoso, J.L. [Área de Física Teórica y Materia Condensada, Universidad Autónoma Metropolitana Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, Azcapotzalco, 02200 México D.F. (Mexico); Kunold, A., E-mail: akb@correo.azc.uam.mx [Área de Física Teórica y Materia Condensada, Universidad Autónoma Metropolitana Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, Azcapotzalco, 02200 México D.F. (Mexico)

    2015-11-15

    We discuss the one-dimensional, time-dependent general quadratic Hamiltonian and the bi-dimensional charged particle in time-dependent electromagnetic fields through the Lie algebraic approach. Such method consists in finding a set of generators that form a closed Lie algebra in terms of which it is possible to express a quantum Hamiltonian and therefore the evolution operator. The evolution operator is then the starting point to obtain the propagator as well as the explicit form of the Heisenberg picture position and momentum operators. First, the set of generators forming a closed Lie algebra is identified for the general quadratic Hamiltonian. This algebra is later extended to study the Hamiltonian of a charged particle in electromagnetic fields exploiting the similarities between the terms of these two Hamiltonians. These results are applied to the solution of five different examples: the linear potential which is used to introduce the Lie algebraic method, a radio frequency ion trap, a Kanai–Caldirola-like forced harmonic oscillator, a charged particle in a time dependent magnetic field, and a charged particle in constant magnetic field and oscillating electric field. In particular we present exact analytical expressions that are fitting for the study of a rotating quadrupole field ion trap and magneto-transport in two-dimensional semiconductor heterostructures illuminated by microwave radiation. In these examples we show that this powerful method is suitable to treat quadratic Hamiltonians with time dependent coefficients quite efficiently yielding closed analytical expressions for the propagator and the Heisenberg picture position and momentum operators. -- Highlights: •We deal with the general quadratic Hamiltonian and a particle in electromagnetic fields. •The evolution operator is worked out through the Lie algebraic approach. •We also obtain the propagator and Heisenberg picture position and momentum operators. •Analytical expressions for a

  4. Metastable decoherence-free subspaces and electromagnetically induced transparency in interacting many-body systems

    DEFF Research Database (Denmark)

    Macieszczak, Katarzyna; Zhou, Yanli; Hofferberth, Sebastian

    2017-01-01

    to stationarity this leads to a slow dynamics, which renders the typical assumption of fast relaxation invalid. We derive analytically the effective nonequilibrium dynamics in the decoherence-free subspace, which features coherent and dissipative two-body interactions. We discuss the use of this scenario...

  5. Parity violation in atoms and implications for unified models of weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Jarlskog, C.

    1976-07-01

    Parity violation experiments in atoms are probing structure of the weak neutral current couplings of the electrons and the quarks in the same range as the neutrino interactions are measuring couplings of neutrinos and quarks. In addition, leptonic neutral currents determine couplings of neutrinos and electrons. Therefore the three type of experiments give complete information and impose strong restrictions on theoretical possibilities. (BJ) [de

  6. Relativistic configuration interaction treatment of generalized oscillator strength for krypton

    International Nuclear Information System (INIS)

    Wang Huangchun; Qu Yizhi; Liu Chunhua

    2007-01-01

    A fully relativistic configuration interaction method is developed to investigate the transition energies and general oscillator strengths of the lower lying states of krypton, for both optically allowed and optically forbidden transitions. The calculated results are in agreement with the recent experimental measurements. The calculated transition energies for the 5s and 5s' transitions are 9.970 and 10.717 eV, which agree with the experimental data of 10.033 and 10.643 eV. The calculated oscillator strengths are 0.211 and 0.170, comparable with the experimental results 0.214(±0.012) and 0.194 (±0.012), respectively. The momentum transfer positions (K 2 in a.u.) of the minimum and maximum GOSs in the 4s 2 4p 6 →4s 2 4p 5 (5s + 5s') transitions are 1.105 and 2.225, comparable with the measurements results 1.24 and 2.97. (authors)

  7. Relativistic Configuration Interaction Treatment of Generalized Oscillator Strength for Krypton

    Institute of Scientific and Technical Information of China (English)

    WANG Huang-Chun; QU Yi-Zhi; LIU Chun-Hua

    2007-01-01

    A fully relativistic configuration interaction method is developed to investigate the transition energies and general oscillator strengths of the lower lying states of krypton, for both optically allowed and optically forbidden transitions. The calculated results are in agreement with the recent experimental measurements. The calculated transition energies for the 5s and 5s' transitions are 9.970 and 10.717eV, which agree with the experimental data of 10.033 and 10.643 eV. The calculated oscillator strengths are 0.211 and 0.170, comparable with the experimental results 0.214(±0.012) and 0.194 (±0.012), respectively. The momentum transfer positions ( K2 in a.u.) of the minimum and maximum GOSs in the 4s24p6 → 4s24p5 (5s + 5s') transitions are 1.105 and 2.225, comparable with the measurements results 1.24 and 2.97 [Phys. Rev. A 67 (2003) 062708].

  8. Electromagnetic Gowdy universe

    International Nuclear Information System (INIS)

    Charach, C.

    1979-01-01

    Following Gowdy and Berger we construct an inhomogeneous closed electromagnetic universe with three-torus topology. This model is obtained as a result of the homogeneity breaking in the electromagnetic Bianchi type-I universe and contains interacting gravitational and electromagnetic waves. This cosmological solution provides an exactly solvable model for the study of the nonlinear fully relativistic regime of coupled electromagnetic and gravitational fields in the early universe. The asymptotic behavior is considered (i) in the vicinity of the initial singularity and (ii) in the high-frequency limit. It is shown that the effects of coupling between electromagnetic and gravitational waves cause an evolution which is significantly different from that of the vacuum model. The influence of the primordial homogeneous electromagnetic field on the dynamics of the model is also discussed

  9. Electromagnetic Reciprocity.

    Energy Technology Data Exchange (ETDEWEB)

    Aldridge, David F.

    2014-11-01

    A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories

  10. Gravity as a dynamical consequence of the strong, weak, and electromagnetic interactions

    International Nuclear Information System (INIS)

    Zee, A.

    1981-12-01

    A coherent and reasonable account of gravitational physics is shown to be possible. The three non-gravitational interactions are described by a scale and conformal invariant and asymptotically free Yang-Mills theory with massless fermions. Conformal invariance is required so that the gravitational sector of the theory is given by the Weyl action. The theory is renormalizable and has a unitary S-matrix. Possible breakdown of causality is observable only at the Planck length. In this theory, Einstein's theory of gravity is induced as an effective long-distance theory. An R 2 term is also induced with a finite and physically desired sign

  11. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis......, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc....

  12. A Unified Field Theory of Gravity, Electromagnetism, and the Yang-Mills Gauge Field

    Directory of Open Access Journals (Sweden)

    Suhendro I.

    2008-01-01

    Full Text Available In this work, we attempt at constructing a comprehensive four-dimensional unified field theory of gravity, electromagnetism, and the non-Abelian Yang-Mills gauge field in which the gravitational, electromagnetic, and material spin fields are unified as intrinsic geometric objects of the space-time manifold S4 via the connection, with the general- ized non-Abelian Yang-Mills gauge field appearing in particular as a sub-field of the geometrized electromagnetic interaction.

  13. Laser interaction effects of electromagnetic absorption and microstructural defects on hot-spot formation in RDX-PCTFE energetic aggregates

    International Nuclear Information System (INIS)

    Brown, Judith A; LaBarbera, Darrell A; Zikry, Mohammed A

    2014-01-01

    Hot-spot formation in energetic aggregates subjected to dynamic pressure loading and laser irradiation has been investigated. Specialized finite-element techniques with a dislocation-density-based crystalline plasticity constitutive formulation and thermo-mechanical coupling of heat conduction, adiabatic heating, laser heating and thermal decomposition were used to predict hot-spot formation in RDX–polymer aggregates subjected to dynamic pressures and laser energies. The effects of the electromagnetic absorption coefficient coupled with void distribution and spacing, grain morphology, crystal–binder interactions and dislocation densities were analyzed to determine their influence on the time, location and mechanisms of hot-spot formation. Four different mechanisms for hot-spot initiation under dynamic laser and pressure loads were identified, which depend on the localization of plastic shear strain and laser heat absorption within the aggregate. The predictions indicate that hot-spot formation is accelerated by higher absorption coefficients and by localized plastic deformations that occur in areas of significant laser heating. (paper)

  14. Forward production of J//psi/ in hadronic interactions and calibration of a large BGO electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Kaaret, P.E.

    1989-06-01

    In the first part of this thesis, we describe an analysis of J//psi/ produced in the forward direction in the reaction πN → μ + μ/sup /minus//X. The data for this analysis were collected by Fermilab experiment E615. We measured the cross section for J//psi/ production and the angular distribution of muons from J//psi/ decay. We found evidence for longitudinal polarization of J//psi/ produced in the kinematic limit where the J//psi/ carries a large fraction of the incident pion's longitudinal momentum. This is the first experimental observation of longitudinal polarization of J//psi/ produced in hadronic interactions. In the second part of this thesis, we describe the construction and calibration of a large Bismuth Germanante (BGO) electromagnetic calorimeter designed to study e + e/sup /minus// collisions at center-of-mass energies near the Z 0 mass. The calorimeter is a subdetector of the L3 detector and will be installed in the Large Electron Positron collider (LEP) of the European Organization for Nuclear Research. We present the results of a calibration of the calorimeter in an electron test beam at electron energies of 2, 10, and 50 GeV. We show that the accuracy of the calibration is 0.8% at 2 GeV, improving to better than 0.5% at 10 GeV and above. 65 refs., 72 figs., 21 tabs

  15. An SU(3)xU(1) theory of weak-electromagnetic interactions with charged boson mixing

    International Nuclear Information System (INIS)

    Singer, M.

    1978-01-01

    An SU(3)xU(1) gauge theory of weak electromagnetic interactions is proposed in which the charged bosons mix with each other. The model naturally ensures e-μ and quark-lepton universality in couplings, and the charged boson mixing permits an equal number of leptons and quark flavours. There are no new stable leptons. All the fermions are placed in triplets and singlets and the theory is vector-like and hence free of anomalies. In addition one of the charged bosons can have a mass less than 43 GeV. Discrete symmetries and specific choices for Higgs fields are postulated to obtain the appropriate boson and fermion masses. Calculations for the decay of the tau particle, which is described as a heavy electron, are given. Multimuon events are discussed as are neutrino neutral currents. Calculations are also given for testing asymmetries in e-hadron scattering due to weak electron neutral currents along with other phenomenology of the model

  16. Effect of electromagnetic interaction during fusion welding of AISI 2205 duplex stainless steel on the corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    García-Rentería, M.A., E-mail: marcogarciarenteria@uadec.edu.mx [Faculty of Metallurgy, Autonomous University of Coahuila, Carretera 57 Km. 5, CP 25720, Monclova, Coahuila (Mexico); López-Morelos, V.H., E-mail: vhlopez@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); González-Sánchez, J., E-mail: jagonzal@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); García-Hernández, R., E-mail: rgarcia@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); Dzib-Pérez, L., E-mail: franciscocl7@yahoo.com.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); Curiel-López, F.F., E-mail: franciscocl7@yahoo.com.mx [Faculty of Metallurgy, Autonomous University of Coahuila, Carretera 57 Km. 5, CP 25720, Monclova, Coahuila (Mexico)

    2017-02-28

    Highlights: • Application of EMILI during welding 2205 Duplex stainless steel hindered the coarsening of δ grains in HTHAZ and promoted regeneration of γ. • Welds made with simultaneous EMILI presented TPI values at the HTHAZ similar to those for BM. • Welds made under 3, 12 and 15 mT presented a mass loss by anodic polarisation similar to that observed for the as-received BM. • This behaviour is due to changes in the dynamics of microstructural evolution during welding with EMILI. - Abstract: The effect of electromagnetic interaction of low intensity (EMILI) applied during fusion welding of AISI 2205 duplex stainless steel on the resistance to localised corrosion in natural seawater was investigated. The heat affected zone (HAZ) of samples welded under EMILI showed a higher temperature for pitting initiation and lower dissolution under anodic polarisation in chloride containing solutions than samples welded without EMILI. The EMILI assisted welding process developed in the present work enhanced the resistance to localised corrosion due to a modification on the microstructural evolution in the HAZ and the fusion zone during the thermal cycle involved in fusion welding. The application of EMILI reduced the size of the HAZ, limited coarsening of the ferrite grains and promoted regeneration of austenite in this zone, inducing a homogeneous passive condition of the surface. EMILI can be applied during fusion welding of structural or functional components of diverse size manufactured with duplex stainless steel designed to withstand aggressive environments such as natural seawater or marine atmospheres.

  17. Effect of electromagnetic interaction during fusion welding of AISI 2205 duplex stainless steel on the corrosion resistance

    Science.gov (United States)

    García-Rentería, M. A.; López-Morelos, V. H.; González-Sánchez, J.; García-Hernández, R.; Dzib-Pérez, L.; Curiel-López, F. F.

    2017-02-01

    The effect of electromagnetic interaction of low intensity (EMILI) applied during fusion welding of AISI 2205 duplex stainless steel on the resistance to localised corrosion in natural seawater was investigated. The heat affected zone (HAZ) of samples welded under EMILI showed a higher temperature for pitting initiation and lower dissolution under anodic polarisation in chloride containing solutions than samples welded without EMILI. The EMILI assisted welding process developed in the present work enhanced the resistance to localised corrosion due to a modification on the microstructural evolution in the HAZ and the fusion zone during the thermal cycle involved in fusion welding. The application of EMILI reduced the size of the HAZ, limited coarsening of the ferrite grains and promoted regeneration of austenite in this zone, inducing a homogeneous passive condition of the surface. EMILI can be applied during fusion welding of structural or functional components of diverse size manufactured with duplex stainless steel designed to withstand aggressive environments such as natural seawater or marine atmospheres.

  18. Semileptonic weak and electromagnetic interactions in nuclei: recoil polarization in muon capture

    International Nuclear Information System (INIS)

    Rosenfelder, R.

    1979-01-01

    An analysis of the polarization of the recoiling nucleus following the capture of polarized muons by nuclei is performed. New general expressions for arbitrary nuclear spin are obtained in terms of the same reduced matrix elements which govern inelastic electron scattering and β-decay. As an application the A = 12 system is considered and uncertainties in the nuclear structure are studied by using different sets of one-body density matrices. With the canonical values of the weak form factors (i.e. absence of second-class currents) a fairly good agreement with the experimental data is achieved including the inelastic form factor at high momentum transfers and the recently measured average 12 B polarization. Implications of the new corrected value of the average polarization on weak form factors and nuclear structure are discussed. (Auth.)

  19. Electromagnetic fields in biological systems

    National Research Council Canada - National Science Library

    Lin, James C

    2012-01-01

    "Focusing on exposure, induced fields, and absorbed energy, this volume covers the interaction of electromagnetic fields and waves with biological systems, spanning static fields to terahertz waves...

  20. Interaction with the lower ionosphere of electromagnetic pulses from lightning - Heating, attachment, and ionization

    Science.gov (United States)

    Taranenko, Y. N.; Inan, U. S.; Bell, T. F.

    1993-01-01

    A Boltzmann formulation of the electron distribution function and Maxwell's equations for the EM fields are used to simulate the interaction of lightning radiated EM pulses with the lower ionosphere. Ionization and dissociative attachment induced by the heated electrons cause significant changes in the local electron density, N(e). Due to 'slow' field changes of typical lightning EM pulses over time scales of tens of microsec, the distribution function follows the quasi-equilibrium solution of the Boltzmann equation in the altitude range of interest (70 to 100 km). The EM pulse is simulated as a planar 100 microsec long single period oscillation of a 10 kHz wave injected at 70 km. Under nighttime conditions, individual pulses of intensity 10-20 V/m (normalized to 100 km horizontal distance) produce changes in N(e) of 1-30 percent while a sequence of pulses leads to strong modification of N(e) at altitudes less than 95 km. The N(e) changes produce a 'sharpening' of the lower ionospheric boundary by causing a reduction in electron density at 75-85 km (due to attachment) and a substantial increase at 85-95 km (due to ionization) (e.g., the scale height decreases by a factor of about 2 at about 85 km for a single 20 V/m EM pulse). No substantial N(e) changes occur during daytime.

  1. Electron-photon and electron-electron interactions in the presence of strong electromagnetic fields

    International Nuclear Information System (INIS)

    Surzhykov, A.; Fritzsche, S.; Stoehlker, Th.

    2010-01-01

    During the last decade, photon emission from highly-charged, heavy ions has been in the focus of intense studies at the GSI accelerator and storage ring facility in Darmstadt. These studies have revealed unique information about the electron-electron and electron-photon interactions in the presence of extremely strong nuclear fields. Apart from the radiative electron capture processes, characteristic photon emission following collisional excitation of projectile ions has also attracted much interest. In this contribution, we summarize the recent theoretical studies on the production of excited ionic states and their subsequent radiative decay. We will pay special attention to the angular and polarization properties of Kα emission from helium-like ions produced by means of dielectronic recombination. The results obtained for this (resonant) capture process will be compared with the theoretical predictions for the characteristic X-rays following Coulomb excitation and radiative recombination of few-electron, heavy ions. Work is supported by Helmholtz Association and GSl under the project VH-NG--421. (author)

  2. General quadrupole shapes in the Interacting Boson Model

    International Nuclear Information System (INIS)

    Leviatan, A.

    1990-01-01

    Characteristic attributes of nuclear quadrupole shapes are investigated within the algebraic framework of the Interacting Boson Model. For each shape the Hamiltonian is resolved into intrinsic and collective parts, normal modes are identified and intrinsic states are constructed and used to estimate transition matrix elements. Special emphasis is paid to new features (e.g. rigid triaxiality and coexisting deformed shapes) that emerge in the presence of the three-body interactions. 27 refs

  3. Interaction of relativistic elementary atoms with matter. I. General formulas

    International Nuclear Information System (INIS)

    Mrowczyn'ski, S.

    1987-01-01

    The problem of the interaction of relativistic elementary atoms (Coulomb bound states of elementary particles such as positronium, pionium, etc.) with matter is studied in the reference frame where the atom is initially at rest. An atom of matter is treated as a spinless structureless fast particle. The amplitudes of elementary-atom interaction are derived in the Born approximation under the assumption that a momentum transfer to the atom does not significantly exceed an inverse Bohr radius of the atom. The elementary-atom excitation and ionization processes are considered. The transitions where the spin projection of the atom component is reversed are also studied. In particular the matrix elements for para-ortho and ortho-para transitions are given. The spin structure of the amplitudes is discussed in detail. The sum rules, which allow the calculation of the cross sections summed over atom final states are found. Finally the formulas of the atom interaction cross sections are presented

  4. A generalized coherence framework for detecting and characterizing nonlinear interactions in the nervous system

    NARCIS (Netherlands)

    Yang, Y.; Solis Escalante, T.; van der Helm, F.C.T.; Schouten, A.C.

    2016-01-01

    Objective: This paper introduces a generalized coherence framework for detecting and characterizing nonlinear interactions in the nervous system, namely cross-spectral coherence (CSC). CSC can detect different types of nonlinear interactions including harmonic and intermodulation coupling as present

  5. Electromagnetic ion-cyclotron instability in the presence of a parallel electric field with general loss-cone distribution function - particle aspect analysis

    Directory of Open Access Journals (Sweden)

    G. Ahirwar

    2006-08-01

    Full Text Available The effect of parallel electric field on the growth rate, parallel and perpendicular resonant energy and marginal stability of the electromagnetic ion-cyclotron (EMIC wave with general loss-cone distribution function in a low β homogeneous plasma is investigated by particle aspect approach. The effect of the steepness of the loss-cone distribution is investigated on the electromagnetic ion-cyclotron wave. The whole plasma is considered to consist of resonant and non-resonant particles. It is assumed that resonant particles participate in the energy exchange with the wave, whereas non-resonant particles support the oscillatory motion of the wave. The wave is assumed to propagate parallel to the static magnetic field. The effect of the parallel electric field with the general distribution function is to control the growth rate of the EMIC waves, whereas the effect of steep loss-cone distribution is to enhance the growth rate and perpendicular heating of the ions. This study is relevant to the analysis of ion conics in the presence of an EMIC wave in the auroral acceleration region of the Earth's magnetoplasma.

  6. Collaboration and interaction of first responders with the general public

    NARCIS (Netherlands)

    Emmerik, M. van; Dinesen, C.; Rijk, R. van; Bird, M.; Wester, M.; Hansen, L.J.; Vinther-Larsen, L.; Padron, C.; Boswinkel, R.; Ven, J. van de

    2016-01-01

    There is an increased focus on the need for collaboration between first responders and the general public. This type of collaboration requires soft skills that are not necessarily included in more traditional command and control trainings for first responders. Learning to collaborate with the

  7. Nonlinear surface electromagnetic phenomena

    CERN Document Server

    Ponath, H-E

    1991-01-01

    In recent years the physics of electromagnetic surface phenomena has developed rapidly, evolving into technologies for communications and industry, such as fiber and integrated optics. The variety of phenomena based on electromagnetism at surfaces is rich and this book was written with the aim of summarizing the available knowledge in selected areas of the field. The book contains reviews written by solid state and optical physicists on the nonlinear interaction of electromagnetic waves at and with surfaces and films. Both the physical phenomena and some potential applications are

  8. Interaction of a two-dimensional electromagnetic breather with an electron inhomogeneity in an array of carbon nanotubes

    International Nuclear Information System (INIS)

    Zhukov, Alexander V.; Bouffanais, Roland; Fedorov, E. G.; Belonenko, Mikhail B.

    2014-01-01

    Propagation of ultrashort laser pulses through various nano-objects has recently became an attractive topic for both theoretical and experimental studies due to its promising perspectives in a variety of problems of modern nanoelectronics. Here, we study the propagation of extremely short two-dimensional bipolar electromagnetic pulses in a heterogeneous array of semiconductor carbon nanotubes. Heterogeneity is defined as a region of enhanced electron density. The electromagnetic field in an array of nanotubes is described by Maxwell's equations, reduced to a multidimensional wave equation. Our numerical analysis shows the possibility of stable propagation of an electromagnetic pulse in a heterogeneous array of nanotubes. Furthermore, we establish that, depending on its speed of propagation, the pulse can pass through the area of increased electron concentration or be reflected therefrom.

  9. Mathematics and electromagnetism

    International Nuclear Information System (INIS)

    Rodriguez Danta, M.

    2000-01-01

    Symbiosis between mathematics and electromagnetism is analyzed in a simple and concise manner by taking a historical perspective. The universal tool character of mathematical models allowed the transfer of models from several branches of physics into the realm of electromagnetism by drawing analogies. The mutual interdependence between covariant formulation and tensor calculus is marked. The paper focuses on the guiding idea of field theory and Maxwell's equations. Likewise, geometrization of interactions in connection with gauge fields is also noted. (Author)

  10. GIANT: a computer code for General Interactive ANalysis of Trajectories

    International Nuclear Information System (INIS)

    Jaeger, J.; Lee, M.; Servranckx, R.; Shoaee, H.

    1985-04-01

    Many model-driven diagnostic and correction procedures have been developed at SLAC for the on-line computer controlled operation of SPEAR, PEP, the LINAC, and the Electron Damping Ring. In order to facilitate future applications and enhancements, these procedures are being collected into a single program, GIANT. The program allows interactive diagnosis as well as performance optimization of any beam transport line or circular machine. The test systems for GIANT are those of the SLC project. The organization of this program and some of the recent applications of the procedures will be described in this paper

  11. Electromagnetic spatial coherence wavelets

    International Nuclear Information System (INIS)

    Castaneda, R.; Garcia-Sucerquia, J.

    2005-10-01

    The recently introduced concept of spatial coherence wavelets is generalized for describing the propagation of electromagnetic fields in the free space. For this aim, the spatial coherence wavelet tensor is introduced as an elementary amount, in terms of which the formerly known quantities for this domain can be expressed. It allows analyzing the relationship between the spatial coherence properties and the polarization state of the electromagnetic wave. This approach is completely consistent with the recently introduced unified theory of coherence and polarization for random electromagnetic beams, but it provides a further insight about the causal relationship between the polarization states at different planes along the propagation path. (author)

  12. Perception of health risks of electromagnetic fields by MRI radiographers and airport security officers compared to the general Dutch working population: a cross sectional analysis.

    Science.gov (United States)

    van Dongen, Diana; Smid, Tjabe; Timmermans, Daniëlle R M

    2011-11-09

    The amount of exposure to electromagnetic fields (EMF) at work is mainly determined by an individual's occupation and may differ from exposure at home. It is, however, unknown how different occupational groups perceive possible adverse health effects of EMF. Three occupational groups, the general Dutch working population (n = 567), airport security officers who work with metal detectors (n = 106), and MRI radiographers who work with MRI (n = 193), were compared on perceived risk of and positive and negative feelings towards EMF in general and of different EMF sources, and health concerns by using analyses of variances. Data were collected via an internet survey. Overall, MRI radiographers had a lower perceived risk, felt less negative, and more positive towards EMF and different sources of EMF than the general working population and the security officers. For security officers, feeling more positive about EMF was not significantly related to perceived risk of EMF in general or EMF of domestic sources. Feeling positive about a source did not generalize to a lower perceived risk, while negative feelings were stronger related to perceived risk. MRI radiographers had fewer health concerns regarding EMF than the other two groups, although they considered it more likely that EMF could cause physical complaints. These data show that although differences in occupation appear to be reflected in different perceptions of EMF, the level of occupational exposure to EMF as such does not predict the perceived health risk of EMF. © 2011 van Dongen et al; licensee BioMed Central Ltd.

  13. Perception of health risks of electromagnetic fields by MRI radiographers and airport security officers compared to the general Dutch working population: a cross sectional analysis

    Directory of Open Access Journals (Sweden)

    van Dongen Diana

    2011-11-01

    Full Text Available Abstract Background The amount of exposure to electromagnetic fields (EMF at work is mainly determined by an individual's occupation and may differ from exposure at home. It is, however, unknown how different occupational groups perceive possible adverse health effects of EMF. Methods Three occupational groups, the general Dutch working population (n = 567, airport security officers who work with metal detectors (n = 106, and MRI radiographers who work with MRI (n = 193, were compared on perceived risk of and positive and negative feelings towards EMF in general and of different EMF sources, and health concerns by using analyses of variances. Data were collected via an internet survey. Results Overall, MRI radiographers had a lower perceived risk, felt less negative, and more positive towards EMF and different sources of EMF than the general working population and the security officers. For security officers, feeling more positive about EMF was not significantly related to perceived risk of EMF in general or EMF of domestic sources. Feeling positive about a source did not generalize to a lower perceived risk, while negative feelings were stronger related to perceived risk. MRI radiographers had fewer health concerns regarding EMF than the other two groups, although they considered it more likely that EMF could cause physical complaints. Conclusions These data show that although differences in occupation appear to be reflected in different perceptions of EMF, the level of occupational exposure to EMF as such does not predict the perceived health risk of EMF.

  14. Short-distance expansion for the electromagnetic half-space Green's tensor: general results and an application to radiative lifetime computations

    International Nuclear Information System (INIS)

    Panasyuk, George Y; Schotland, John C; Markel, Vadim A

    2009-01-01

    We obtain a short-distance expansion for the half-space, frequency domain electromagnetic Green's tensor. The small parameter of the theory is ωε 1 L/c, where ω is the frequency, ε 1 is the permittivity of the upper half-space, in which both the source and the point of observation are located, and which is assumed to be transparent, c is the speed of light in vacuum and L is a characteristic length, defined as the distance from the point of observation to the reflected (with respect to the planar interface) position of the source. In the case when the lower half-space (the substrate) is characterized by a complex permittivity ε 2 , we compute the expansion to third order. For the case when the substrate is a transparent dielectric, we compute the imaginary part of the Green's tensor to seventh order. The analytical calculations are verified numerically. The practical utility of the obtained expansion is demonstrated by computing the radiative lifetime of two electromagnetically interacting molecules in the vicinity of a transparent dielectric substrate. The computation is performed in the strong interaction regime when the quasi-particle pole approximation is inapplicable. In this regime, the integral representation for the half-space Green's tensor is difficult to use while its electrostatic limiting expression is grossly inadequate. However, the analytical expansion derived in this paper can be used directly and efficiently. The results of this study are also relevant to nano-optics and near-field imaging, especially when tomographic image reconstruction is involved

  15. Finite-element time-domain modeling of electromagnetic data in general dispersive medium using adaptive Padé series

    Science.gov (United States)

    Cai, Hongzhu; Hu, Xiangyun; Xiong, Bin; Zhdanov, Michael S.

    2017-12-01

    The induced polarization (IP) method has been widely used in geophysical exploration to identify the chargeable targets such as mineral deposits. The inversion of the IP data requires modeling the IP response of 3D dispersive conductive structures. We have developed an edge-based finite-element time-domain (FETD) modeling method to simulate the electromagnetic (EM) fields in 3D dispersive medium. We solve the vector Helmholtz equation for total electric field using the edge-based finite-element method with an unstructured tetrahedral mesh. We adopt the backward propagation Euler method, which is unconditionally stable, with semi-adaptive time stepping for the time domain discretization. We use the direct solver based on a sparse LU decomposition to solve the system of equations. We consider the Cole-Cole model in order to take into account the frequency-dependent conductivity dispersion. The Cole-Cole conductivity model in frequency domain is expanded using a truncated Padé series with adaptive selection of the center frequency of the series for early and late time. This approach can significantly increase the accuracy of FETD modeling.

  16. General considerations on the oxide fuel-cladding chemical interaction

    International Nuclear Information System (INIS)

    Pascard, R.

    1977-01-01

    Since the very first experimental irradiations in thermal reactors, performed in view of the future Rapsodie fuel general study, corrosion cladding anomalies were observed. After 10 years of Rapsodie and more than two years of Phenix, performance brought definite confirmation of the chemical reactions between the irradiated fuel and cladding. That is the reason for which the fuel designers express an urgent need for determining the corrosion rates. Semi-empirical laws and mechanisms describing corrosion processes are proposed. Erratic conditions for appearance of the oxide-cladding corrosion are stressed upon. Obviously such a problem can be fully appreciated only by a statistical approach based on a large number of observations on the true LMFBR fuel pins

  17. Self-organization of large-scale ULF electromagnetic wave structures in their interaction with nonuniform zonal winds in the ionospheric E region

    International Nuclear Information System (INIS)

    Aburjania, G. D.; Chargazia, Kh. Z.

    2011-01-01

    A study is made of the generation and subsequent linear and nonlinear evolution of ultralow-frequency planetary electromagnetic waves in the E region of a dissipative ionosphere in the presence of a nonuniform zonal wind (a sheared flow). Hall currents flowing in the E region and such permanent global factors as the spatial nonuniformity of the geomagnetic field and of the normal component of the Earth’s angular velocity give rise to fast and slow planetary-scale electromagnetic waves. The efficiency of the linear amplification of planetary electromagnetic waves in their interaction with a nonuniform zonal wind is analyzed. When there are sheared flows, the operators of linear problems are non-self-conjugate and the corresponding eigenfunctions are nonorthogonal, so the canonical modal approach is poorly suited for studying such motions and it is necessary to utilize the so-called nonmodal mathematical analysis. It is shown that, in the linear evolutionary stage, planetary electromagnetic waves efficiently extract energy from the sheared flow, thereby substantially increasing their amplitude and, accordingly, energy. The criterion for instability of a sheared flow in an ionospheric medium is derived. As the shear instability develops and the perturbation amplitude grows, a nonlinear self-localization mechanism comes into play and the process ends with the self-organization of nonlinear, highly localized, solitary vortex structures. The system thus acquires a new degree of freedom, thereby providing a new way for the perturbation to evolve in a medium with a sheared flow. Depending on the shape of the sheared flow velocity profile, nonlinear structures can be either purely monopole vortices or vortex streets against the background of the zonal wind. The accumulation of such vortices can lead to a strongly turbulent state in an ionospheric medium.

  18. Nuclear structure investigations with electromagnetic probes

    International Nuclear Information System (INIS)

    Drechsel, D.

    1987-01-01

    This paper is related to the study of electromagnetic interactions, current of hadronic systems, deep inelastic scattering, quasifree scattering, low energy theorems and electromagnetic reactions above pion threshold. (A.C.A.S.) [pt

  19. The Interaction of a N-Type Four Level Atom with the Electromagnetic Field for a Kerr Medium Induced Intensity-Dependent Coupling

    Science.gov (United States)

    Othman, Anas; Yevick, David

    2018-01-01

    The interaction of a N-type four-level atom with a single field in the presence of an intensity-dependent coupling in a nonlinear Kerr medium is investigated. The exact analytic solution is obtained in the case that the atom and electromagnetic field are initially in a higher excited state and a coherent state, respectively. It is then demonstrated that effects such as nonclassical light generation, degree of entanglement stabilization, Kerr medium nonclassical control, and squeezed light are can be more efficiently implemented within this four-level framework than in many competing procedures. Additionally, inversion, linear entropy, Mandel Q-parameter and normal squeezing dynamics are examined.

  20. Positive expectations encourage generalization from a positive intergroup interaction to outgroup attitudes.

    Science.gov (United States)

    Deegan, Matthew P; Hehman, Eric; Gaertner, Samuel L; Dovidio, John F

    2015-01-01

    The current research reveals that while positive expectations about an anticipated intergroup interaction encourage generalization of positive contact to outgroup attitudes, negative expectations restrict the effects of contact on outgroup attitudes. In Study 1, when Blacks and Whites interacted with positive expectations, interaction quality predicted outgroup attitudes to a greater degree than when groups interacted with negative expectations. When expectations (Studies 2 and 3) and the actual interaction quality (Study 4) were manipulated orthogonally, negative expectations about the interaction predicted negative outgroup attitudes, regardless of actual interaction quality. By contrast, participants holding positive expectations who experienced a positive interaction expressed positive outgroup attitudes, whereas when they experienced a negative interaction, they expressed outgroup attitudes as negative as those with negative expectations. Across all four studies, positive expectations encouraged developing outgroup attitudes consistent with interaction quality. © 2014 by the Society for Personality and Social Psychology, Inc.

  1. An Assessment of Hazards Caused by Electromagnetic Interaction on Humans Present near Short-Wave Physiotherapeutic Devices of Various Types Including Hazards for Users of Electronic Active Implantable Medical Devices (AIMD

    Directory of Open Access Journals (Sweden)

    Jolanta Karpowicz

    2013-01-01

    Full Text Available Leakage of electromagnetic fields (EMF from short-wave radiofrequency physiotherapeutic diathermies (SWDs may cause health and safety hazards affecting unintentionally exposed workers (W or general public (GP members (assisting patient exposed during treatment or presenting there for other reasons. Increasing use of electronic active implantable medical devices (AIMDs, by patients, attendants, and workers, needs attention because dysfunctions of these devices may be caused by electromagnetic interactions. EMF emitted by 12 SWDs (with capacitive or inductive applicators were assessed following international guidelines on protection against EMF exposure (International Commission on Nonionizing Radiation Protection for GP and W, new European directive 2013/35/EU for W, European Recommendation for GP, and European Standard EN 50527-1 for AIMD users. Direct EMF hazards for humans near inductive applicators were identified at a distance not exceeding 45 cm for W or 62 cm for GP, but for AIMD users up to 90 cm (twice longer than that for W and 50% longer than that for GP because EMF is pulsed modulated. Near capacitive applicators emitting continuous wave, the corresponding distances were: 120 cm for W or 150 cm for both—GP or AIMD users. This assessment does not cover patients who undergo SWD treatment (but it is usually recommended for AIMD users to be careful with EMF treatment.

  2. Geometrization of the Electromagnetic Field and Dark Matter

    CERN Document Server

    Pestov, I B

    2005-01-01

    A general concept of potential field is introduced. The potential field that one puts in correspondence with dark matter, has fundamental geometrical interpretation (parallel transport) and has intrinsically inherent local symmetry. The equations of dark matter field are derived that are invariant with respect to the local transformations. It is shown how to reduce these equations to the Maxwell equations. Thus, the dark matter field may be considered as generalized lectromagnetic field and a simple solution of the old problem is given to connect electromagnetic field with geometrical properties of the physical manifold itself. It is shown that gauge fixing renders generalized electromagnetic field effectively massive while the Maxwell electromagnetic field remains massless. To learn more about interactions between matter and dark matter on the microscopical level (and to recognize the fundamental role of internal symmetry) the general covariant Dirac equation is derived in the Minkowski space--time which des...

  3. Computational electromagnetic-aerodynamics

    CERN Document Server

    Shang, Joseph J S

    2016-01-01

    Presents numerical algorithms, procedures, and techniques required to solve engineering problems relating to the interactions between electromagnetic fields, fluid flow, and interdisciplinary technology for aerodynamics, electromagnetics, chemical-physics kinetics, and plasmadynamics This book addresses modeling and simulation science and technology for studying ionized gas phenomena in engineering applications. Computational Electromagnetic-Aerodynamics is organized into ten chapters. Chapter one to three introduce the fundamental concepts of plasmadynamics, chemical-physics of ionization, classical magnetohydrodynamics, and their extensions to plasma-based flow control actuators, high-speed flows of interplanetary re-entry, and ion thrusters in space exploration. Chapter four to six explain numerical algorithms and procedures for solving Maxwell’s equation in the time domain for computational electromagnetics, plasma wave propagation, and the time-dependent c mpressible Navier-Stokes equation for aerodyn...

  4. Anomalous electromagnetic coupling via entanglement at the nanoscale

    International Nuclear Information System (INIS)

    Slepyan, Gregory; Boag, Amir; Mordachev, Vladimir; Sinkevich, Eugene; Maksimenko, Sergey; Kuzhir, Polina; Miano, Giovanni; Portnoi, Mikhail E; Maffucci, Antonio

    2017-01-01

    Understanding unwanted mutual interactions between devices at the nanoscale is crucial for the study of the electromagnetic compatibility in nanoelectronic and nanophotonic systems. Anomalous electromagnetic coupling (crosstalk) between nanodevices may arise from the combination of electromagnetic interaction and quantum entanglement. In this paper we study in detail the crosstalk between two identical nanodevices, each consisting of a quantum emitter (atom, quantum dot, etc), capacitively coupled to a pair of nanoelectrodes. Using the generalized susceptibility concept, the overall system is modeled as a two-port within the framework of the electrical circuit theory and it is characterized by the admittance matrix. We show that the entanglement changes dramatically the physical picture of the electromagnetic crosstalk. In particular, the excitation produced in one of the ports may be redistributed in equal parts between both the ports, in spite of the rather small electromagnetic interactions. Such an anomalous crosstalk is expected to appear at optical frequencies in lateral GaAs double quantum dots. A possible experimental set up is also discussed. The classical concepts of interference in the operation of electronic devices, which have been known since the early days of radio-communications and are associated with electromagnetic compatibility, should then be reconsidered at the nanoscale. (paper)

  5. On the design of experiments for the study of extreme field limits in the ultra-relativistic interaction of electromagnetic waves with plasmas

    Science.gov (United States)

    Bulanov, Sergei V.; Esirkepov, Timur Z.; Hayashi, Yukio; Kando, Masaki; Kiriyama, Hiromitsu; Koga, James K.; Kondo, Kiminori; Kotaki, Hideyuki; Pirozhkov, Alexander S.; Bulanov, Stepan S.; Zhidkov, Alexei G.; Chen, Pisin; Neely, David; Kato, Yoshiaki; Narozhny, Nikolay B.; Korn, Georg

    2011-06-01

    The critical electric field of quantum electrodynamics, called also the Schwinger field, is so strong that it produces electron-positron pairs from vacuum, converting the energy of light into matter. Since the dawn of quantum electrodynamics, there has been a dream on how to reach it on Earth. With the rise of laser technology this field has become feasible through the construction of extremely high power lasers or/and with the sophisticated use of nonlinear processes in relativistic plasmas. This is one of the most attractive motivations for extremely high power laser development, i.e. producing matter from vacuum by pure light in fundamental process of quantum electrodynamics in the nonperturbative regime. Recently it has been realized that a laser with intensity well below the Schwinger limit can create an avalanche of electron-positron pairs similar to a discharge before attaining the Schwinger field. It has also been realized that the Schwinger limit can be reached using an appropriate configuration of laser beams. In experiments on the collision of laser light and high intensity electromagnetic pulses generated by relativistic flying mirrors, with electron bunches produced by a conventional accelerator and with laser wake field accelerated electrons the studying of extreme field limits in the nonlinear interaction of electromagnetic waves is proposed. The regimes of dominant radiation reaction, which completely changes the electromagnetic wave-matter interaction, will be revealed. This will result in a new powerful source of high brightness gamma-rays. A possibility of the demonstration of the electronpositron pair creation in vacuum via multi-photon processes can be realized. This will allow modeling under terrestrial laboratory conditions neutron star magnetospheres, cosmological gamma ray bursts and the Leptonic Era of the Universe.

  6. Covariant electromagnetic field lines

    Science.gov (United States)

    Hadad, Y.; Cohen, E.; Kaminer, I.; Elitzur, A. C.

    2017-08-01

    Faraday introduced electric field lines as a powerful tool for understanding the electric force, and these field lines are still used today in classrooms and textbooks teaching the basics of electromagnetism within the electrostatic limit. However, despite attempts at generalizing this concept beyond the electrostatic limit, such a fully relativistic field line theory still appears to be missing. In this work, we propose such a theory and define covariant electromagnetic field lines that naturally extend electric field lines to relativistic systems and general electromagnetic fields. We derive a closed-form formula for the field lines curvature in the vicinity of a charge, and show that it is related to the world line of the charge. This demonstrates how the kinematics of a charge can be derived from the geometry of the electromagnetic field lines. Such a theory may also provide new tools in modeling and analyzing electromagnetic phenomena, and may entail new insights regarding long-standing problems such as radiation-reaction and self-force. In particular, the electromagnetic field lines curvature has the attractive property of being non-singular everywhere, thus eliminating all self-field singularities without using renormalization techniques.

  7. Investigations of the structure and electromagnetic interactions of few body systems. Annual progress report, 1 September 1982-31 August 1983

    International Nuclear Information System (INIS)

    Harper, E.P.; Lehman, D.R.; Prats, F.

    1983-01-01

    The George Washington University nuclear theory group proposes to conduct investigations of the structure and electromagnetic interactions of few-body systems. The structural properties of the very light nuclei are examined by developing theoretical models that begin from the basic interactions between the constituents and that are solved exactly (numerically), i.e., full three- or four-body dynamics. Such models are then used in an attempt to understand the details of the strong and electromagnetic interactions of the few-nucleon nuclei after the basic underlying reaction mechanisms are understood with simpler models. These efforts are becoming increasingly important with the advent of high duty cycle, high current electron accelerators from which valuable data will be forthcoming that should permit unraveling the structure and interactions of the very-light nuclei. Examples of specific work proposed are the following: 1) Set up the equations for the low-energy photodisintegration of 3 He and 3 H including final-state interactions and the E1 plus E2 operators; 2) Develop a unified picture of the p + d → 3 He + γ, p + d → 3 He + π 0 , p + d → 3 H + π + reactions at intermediate energies; 3) Calculate the elastic and inelastic (1 + →0 + ) form factors for 6 Li with three-body (αNN) wave functions; 4) Calculate static properties (RMS radius, magnetic moment, and quadrupole moment) of 6 Li with three-body wave functions; and 5) Develop the theory for the coincidence reactions 6 Li(p,2p)nα, 6 Li(e,e'p)nα, and 6 Li(e,e'd)α. It is anticipated that these efforts will expand the frontiers of our knowledge about few-body nuclei

  8. Applied Electromagnetics

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, H; Marinova, I; Cingoski, V [eds.

    2002-07-01

    These proceedings contain papers relating to the 3rd Japanese-Bulgarian-Macedonian Joint Seminar on Applied Electromagnetics. Included are the following groups: Numerical Methods I; Electrical and Mechanical System Analysis and Simulations; Inverse Problems and Optimizations; Software Methodology; Numerical Methods II; Applied Electromagnetics.

  9. Applied Electromagnetics

    International Nuclear Information System (INIS)

    Yamashita, H.; Marinova, I.; Cingoski, V.

    2002-01-01

    These proceedings contain papers relating to the 3rd Japanese-Bulgarian-Macedonian Joint Seminar on Applied Electromagnetics. Included are the following groups: Numerical Methods I; Electrical and Mechanical System Analysis and Simulations; Inverse Problems and Optimizations; Software Methodology; Numerical Methods II; Applied Electromagnetics

  10. Self-modulation and filamentation of electromagnetic waves in a plasma

    International Nuclear Information System (INIS)

    Bingham, R.; Lashmore-Davies, C.N.

    1976-01-01

    Self-modulation and filamentation of an electromagnetic wave is considered as a problem of the non-linear interaction between electromagnetic and ion waves. A new electro-magnetic modulational instability is obtained, whose threshold is the same as that of the oscillating two-stream instability. A simple geometrical model is given of filamentation when the non-linearity is due to the ponderomotive force. The relationship between the filamentation and electromagnetic modulational instabilities and other parametric instabilities is considered. In particular, it is shown that both electromagnetic modulational and filamentation instabilities can occur at the critical density where they have the same threshold as the modulational instability of a Langmuir wave. Finally, a conservation relation (a generalization of the Manley-Rowe relation) for the wave action density is obtained for the filamentation instability. This shows clearly that this instability results from a four wave interaction. (author)

  11. Investigations of the structure and electromagnetic interactions of few-body systems. Progress report, 1 January 1980-1 October 1980

    International Nuclear Information System (INIS)

    1980-01-01

    Considerable progress has been made on the long-range problems described in the original proposal document (1 February 1979 to 31 January 1980) and on the shorter-range problems described in the last renewal proposal (1 February 1980 to 31 January 1981). This progress concerns few-body structure problems (e.g., the existence of isobar components in 3 H, predictions of few-body-hypernuclei properties as a test of hyperon-nucleon interactions, investigation of the A = 6 ground states with exact three-body calculations, and the relation of triton D-state properties to the deuteron's D-state percentage) and electromagnetic properties and interactions of few-body nuclei (e.g., Coulomb effects in calculating and measuring asymptotic normalization constants, and γ + 3 He breakup reaction mechanisms at intermediate energies). Descriptions of the progress made indicate where each subject stands at present, and emphasize the significant results obtained. A publication list is attached

  12. Testing for constant nonparametric effects in general semiparametric regression models with interactions

    KAUST Repository

    Wei, Jiawei; Carroll, Raymond J.; Maity, Arnab

    2011-01-01

    We consider the problem of testing for a constant nonparametric effect in a general semi-parametric regression model when there is the potential for interaction between the parametrically and nonparametrically modeled variables. The work

  13. Computational Magnetohydrodynamics of General Materials in Generalized Coordinates and Applications to Laser-Target Interactions

    Science.gov (United States)

    MacGillivray, Jeff T.; Peterkin, Robert E., Jr.

    2003-10-01

    We have developed a multiblock arbitrary coordinate Hydromagnetics (MACH) code for computing the time-evolution of materials of arbitrary phase (solid, liquid, gas, and plasma) in response to forces that arise from material and magnetic pressures. MACH is a single-fluid, time-dependent, arbitrary Lagrangian-Eulerian (ALE) magnetohydrodynamic (MHD) simulation environment. The 2 1/2 -dimensional MACH2 and the parallel 3-D MACH3 are widely used in the MHD community to perform accurate simulation of the time evolution of electrically conducting materials in a wide variety of laboratory situations. In this presentation, we discuss simulations of the interaction of an intense laser beam with a solid target in an ambient gas. Of particular interest to us is a laser-supported detonation wave (blast wave) that originates near the surface of the target when the laser intensity is sufficiently large to vaporize target material within the focal spot of the beam. Because the MACH3 simulations are fully three-dimensional, we are able to simulate non-normal laser incidence. A magnetic field is also produced from plasma energy near the edge of the focal spot.

  14. Electromagnetically induced transparency in a plasmonic system comprising of three metal-dielectric-metal parallel slabs: Plasmon- Plasmon interaction

    Directory of Open Access Journals (Sweden)

    M Moradbeigi

    2018-02-01

    Full Text Available In this paper, electromagnetically induced transparency (EIT in a system consisting of associated arrays of parallel slabs (metal-dielectric-metal is studied. The transmission coefficient, the reflection coefficient and the absorption coefficient as function of the incident light frequency by using the transfer matrix method is calculated and numerically discussed. Influence of the thickness of slab and the type of plasmonic metal on the induced transparency has been investigated. It is shown with decreasing the thickness of intermediate slab of length  (dielectric slab, the induced transparency increases due to the strong plasmon–plasmon couplings.

  15. Coherent hybrid electromagnetic field imaging

    Science.gov (United States)

    Cooke, Bradly J [Jemez Springs, NM; Guenther, David C [Los Alamos, NM

    2008-08-26

    An apparatus and corresponding method for coherent hybrid electromagnetic field imaging of a target, where an energy source is used to generate a propagating electromagnetic beam, an electromagnetic beam splitting means to split the beam into two or more coherently matched beams of about equal amplitude, and where the spatial and temporal self-coherence between each two or more coherently matched beams is preserved. Two or more differential modulation means are employed to modulate each two or more coherently matched beams with a time-varying polarization, frequency, phase, and amplitude signal. An electromagnetic beam combining means is used to coherently combine said two or more coherently matched beams into a coherent electromagnetic beam. One or more electromagnetic beam controlling means are used for collimating, guiding, or focusing the coherent electromagnetic beam. One or more apertures are used for transmitting and receiving the coherent electromagnetic beam to and from the target. A receiver is used that is capable of square-law detection of the coherent electromagnetic beam. A waveform generator is used that is capable of generation and control of time-varying polarization, frequency, phase, or amplitude modulation waveforms and sequences. A means of synchronizing time varying waveform is used between the energy source and the receiver. Finally, a means of displaying the images created by the interaction of the coherent electromagnetic beam with target is employed.

  16. Self-Assembled Student Interactions in Undergraduate General Chemistry Clicker Classrooms

    Science.gov (United States)

    MacArthur, James R.; Jones, Loretta

    2013-01-01

    Student interviews, focus groups, and classroom observations were used in an exploratory study of the nature of student interactions in a large (300+ students) general chemistry course taught with clickers. These data suggest that students are self-assembling their learning environment: choosing ways in which to interact with one another during…

  17. Electromagnetic waves in stratified media

    CERN Document Server

    Wait, James R; Fock, V A; Wait, J R

    2013-01-01

    International Series of Monographs in Electromagnetic Waves, Volume 3: Electromagnetic Waves in Stratified Media provides information pertinent to the electromagnetic waves in media whose properties differ in one particular direction. This book discusses the important feature of the waves that enables communications at global distances. Organized into 13 chapters, this volume begins with an overview of the general analysis for the electromagnetic response of a plane stratified medium comprising of any number of parallel homogeneous layers. This text then explains the reflection of electromagne

  18. Some general properties of the Floquet states for the two dimensional interacting fermion systems with quadratic form Hamiltonians

    International Nuclear Information System (INIS)

    Lungu, R. P.

    2002-01-01

    A fermion 2-dimensional interacting system that is coupled with an external classical field having a time periodic dependence is considered. In the absence of the external field, the single-particle Hamiltonian is quadratic and linear with respect to the canonical operators and the particles have static, scalar, two-body self-interactions; in addition, each particle interacts with an external classical field and the coupling functions with the canonical operators (both the momenta and the position coordinates) are time periodic. This model is a generalization of the two-dimensional electron gas in the presence of a monochromatic linear or circular polarized electromagnetic field. Using the Second Quantization version of the Floquet formalism, we obtain the solution of the eigenvalue problem for the Floquet Hamiltonian with the time-reducing transformation method. we construct an unitary transform that produces a transformed Floquet Hamiltonian that is not time dependent; then, the transformed eigenvalue equation can be resolved and this solution is closely related to the solution of the energy eigenvalue equation of the same system in the absence of the external field. This solution of the Floquet problem has the following important consequences: - Green functions and the correlation density functions of this system are related to the corresponding quantities of the conservative system, so it is possible to develop a diagrammatic method for the perturbed evaluation of these quantities in a similar manner to the conservative situation; - when the system is invariant with respect to space translations in the absence of the external field, the diagrammatic analysis can be performed using a space-time Fourier transform, and this property leads to great simplifications and close correspondences to the conservative theory; - it is possible to construct a result similar to the Pauli theorem, i.e. the quasi-energy eigenvalue of the interacting system (when the classical

  19. Mental exercising through simple socializing: social interaction promotes general cognitive functioning.

    Science.gov (United States)

    Ybarra, Oscar; Burnstein, Eugene; Winkielman, Piotr; Keller, Matthew C; Manis, Melvin; Chan, Emily; Rodriguez, Joel

    2008-02-01

    Social interaction is a central feature of people's life and engages a variety of cognitive resources. Thus, social interaction should facilitate general cognitive functioning. Previous studies suggest such a link, but they used special populations (e.g., elderly with cognitive impairment), measured social interaction indirectly (e.g., via marital status), and only assessed effects of extended interaction in correlational designs. Here the relation between mental functioning and direct indicators of social interaction was examined in a younger and healthier population. Study 1 using survey methodology found a positive relationship between social interaction, assessed via amount of actual social contact, and cognitive functioning in people from three age groups including younger adults. Study 2 using an experimental design found that a small amount of social interaction (10 min) can facilitate cognitive performance. The findings are discussed in the context of the benefits social relationships have for so many aspects of people's lives.

  20. A multi-band, multi-level, multi-electron model for efficient FDTD simulations of electromagnetic interactions with semiconductor quantum wells

    Science.gov (United States)

    Ravi, Koustuban; Wang, Qian; Ho, Seng-Tiong

    2015-08-01

    We report a new computational model for simulations of electromagnetic interactions with semiconductor quantum well(s) (SQW) in complex electromagnetic geometries using the finite-difference time-domain method. The presented model is based on an approach of spanning a large number of electron transverse momentum states in each SQW sub-band (multi-band) with a small number of discrete multi-electron states (multi-level, multi-electron). This enables accurate and efficient two-dimensional (2-D) and three-dimensional (3-D) simulations of nanophotonic devices with SQW active media. The model includes the following features: (1) Optically induced interband transitions between various SQW conduction and heavy-hole or light-hole sub-bands are considered. (2) Novel intra sub-band and inter sub-band transition terms are derived to thermalize the electron and hole occupational distributions to the correct Fermi-Dirac distributions. (3) The terms in (2) result in an explicit update scheme which circumvents numerically cumbersome iterative procedures. This significantly augments computational efficiency. (4) Explicit update terms to account for carrier leakage to unconfined states are derived, which thermalize the bulk and SQW populations to a common quasi-equilibrium Fermi-Dirac distribution. (5) Auger recombination and intervalence band absorption are included. The model is validated by comparisons to analytic band-filling calculations, simulations of SQW optical gain spectra, and photonic crystal lasers.

  1. Vision though afocal instruments: generalized magnification and eye-instrument interaction

    Science.gov (United States)

    Harris, William F.; Evans, Tanya

    2018-04-01

    In Gaussian optics all observers experience the same magnification, the instrument's angular magnification, when viewing distant objects though a telescope or other afocal instruments. However, analysis in linear optics shows that this is not necessarily so in the presence of astigmatism. Because astigmatism may distort and rotate images it is appropriate to work with generalized angular magnification represented by a 2 × 2 matrix. An expression is derived for the generalized magnification for an arbitrary eye looking through an arbitrary afocal instrument. With afocal instruments containing astigmatic refracting elements not all eyes experience the same generalized magnification; there is interaction between eye and instrument. Eye-instrument interaction may change as the instrument is rotated about its longitudinal axis, there being no interaction in particular orientations. A simple numerical example is given. For sake of completeness, expressions for generalized magnification are also presented in the case of instruments that are not afocal and objects that are not distant.

  2. Electromagnetic shield

    International Nuclear Information System (INIS)

    Miller, J.S.

    1987-01-01

    An electromagnetic shield is described comprising: closed, electrically-conductive rings, each having an open center; and binder means for arranging the rings in a predetermined, fixed relationship relative to each other, the so-arranged rings and binder means defining an outer surface; wherein electromagnetic energy received by the shield from a source adjacent its outer surface induces an electrical current to flow in a predetermined direction adjacent and parallel to the outer surface, through the rings; and wherein each ring is configured to cause source-induced alternating current flowing through the portion of the ring closest to the outer surface to electromagnetically induce an oppositely-directed current in the portion of the ring furthest from the surface, such oppositely-directed current bucking any source-induced current in the latter ring portion and thus reducing the magnitude of current flowing through it, whereby the electromagnetic shielding effected by the shield is enhanced

  3. Engineering electromagnetics

    CERN Document Server

    Thomas, David T; Hartnett, James P; Hughes, William F

    1973-01-01

    The applications involving electromagnetic fields are so pervasive that it is difficult to estimate their contribution to the industrial output: generation of electricity, power transmission lines, electric motors, actuators, relays, radio, TV and microwave transmission and reception, magnetic storage, and even the mundane little magnet used to hold a paper note on the refrigerator are all electromagnetic in nature. One would be hard pressed to find a device that works without relaying on any electromagnetic principle or effect. This text provides a good theoretical understanding of the electromagnetic field equations but also treats a large number of applications. In fact, no topic is presented unless it is directly applicable to engineering design or unless it is needed for the understanding of another topic. In electrostatics, for example, the text includes discussions of photocopying, ink-jet printing, electrostatic separation and deposition, sandpaper production, paint spraying, and powder coating. In ma...

  4. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Jørgensen, Stina Marie Hasse

    2015-01-01

    Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015.......Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015....

  5. Electro-optic analysis of the influence of target geometry on electromagnetic pulses generated by petawatt laser-matter interactions

    Science.gov (United States)

    Robinson, Timothy; Giltrap, Samuel; Eardley, Samuel; Consoli, Fabrizio; De Angelis, Riccardo; Ingenito, Francesco; Stuart, Nicholas; Verona, Claudio; Smith, Roland A.

    2018-01-01

    We present an analysis of strong laser-driven electromagnetic pulses using novel electro-optic diagnostic techniques. A range of targets were considered, including thin plastic foils (20-550 nm) and mass-limited, optically-levitated micro-targets. Results from foils indicate a dependence of EMP on target thickness, with larger peak electric fields observed with thinner targets. Spectral analysis suggests high repeatability between shots, with identified spectral features consistently detected with earth following ejection of hot electrons from the plasma, in contrast to predictions for pin-mounted foils in the Poyé EMP generation model. With levitated targets, no EMP was measurable above the noise threshold of any diagnostic, despite observation of protons accelerated to >30 MeV energies, suggesting the discharge current contribution to EMP is dominant.

  6. General experiments concerning particle-matter interactions; Experiences interdisciplinaires d'interaction particule-matiere

    Energy Technology Data Exchange (ETDEWEB)

    Dauvergne, D

    2006-07-15

    The author gathers in this document several papers he has already published in order to shed light on different aspects concerning ion-crystal interactions. This document is divided into 3 chapters. In the first chapter the author presents results obtained from experiments dedicated to charge exchanges and energy released by heavy ions in channeling conditions. Different processes involved in ion-electron interactions are considered: The tri-electronic recombination, the electron capture through nuclear excitation (NEEC), resonant transfer and excitation (RTE), resonant transfer and double excitation (RTDE) and electron impact ionization (EII). The second chapter deals with the measurement of nuclear fission times through crystal blocking experiments. The crystal blocking technique allows the measurement in a model-independent way of the recoil distance covered by the excited nucleus during the whole fission process (starting from the initial collision and ending at the scission point). The last chapter is dedicated to the photon impact ionization through the conversion of a high-energy photon into an electron-positron pair.

  7. Lectures on electromagnetism

    CERN Document Server

    Das, Ashok

    2013-01-01

    These lecture notes on electromagnetism have evolved from graduate and undergraduate EM theory courses given by the author at the University of Rochester, with the basics presented with clarity and his characteristic attention to detail. The thirteen chapters cover, in logical sequence, topics ranging from electrostatics, magnetostatics and Maxwell's equations to plasmas and radiation. Boundary value problems are treated extensively, as are wave guides, electromagnetic interactions and fields. This second edition comprises many of the topics expanded with more details on the derivation of vari

  8. Electromagnetic Interference in Implantable Rhythm Devices - The Indian Scenario

    Directory of Open Access Journals (Sweden)

    Johnson Francis

    2002-07-01

    Full Text Available Implantable rhythm device (IRD is the generic name for the group of implantable devices used for diagnosis and treatment of cardiac arrhythmias. Devices in this category include cardiac pacemakers, implantable cardioverter defibrillators and implantable loop recorders. Since these devices have complex microelectronic circuitry and use electromagnetic waves for communication, they are susceptible to interference from extraneous sources of electromagnetic radiation and magnetic energy. Electromagnetic interference (EMI is generally not a major problem outside of the hospital environment. The most important interactions occur when a patient is subjected to medical procedures such as magnetic resonance imaging (MRI, electrocautery and radiation therapy. Two articles in this issue of the journal discusses various aspects of EMI on IRD1,2 . Together these articles provide a good review of the various sources of EMI and their interaction with IRD for the treating physician.

  9. Equivalence principles and electromagnetism

    Science.gov (United States)

    Ni, W.-T.

    1977-01-01

    The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

  10. Investigations of the structure and electromagnetic interactions of few-body systems. Progress report, 1 July 1991--30 June 1994

    International Nuclear Information System (INIS)

    Lehman, D.R.; Haberzettl, H.; Maximon, L.C.; Parke, W.C.; Bennhold, C.; Ito, Hiroshi; Pratt, R.K.; Najmeddine, M.; Rakei, A.

    1994-07-01

    In order to make it easy for the reader to see the specific research carried out and the progress made, the following report of progress is done by topic. Each item has a format layout of Topic, Investigators, Objective, Significance, and Description of Progress, followed at the end by the relevant references. As is clear from the topics listed, the emphasis of the GW nuclear theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered, including coherent photoproduction of π mesons. When the excitation energy of the target nucleus is low, the aim has been to handle the continuum part of the theoretical work numerically with no approximations, that is, by means of full three- or four-body dynamics. When structure questions are the issue, numerically accurate calculations are always carried through, limited only by the underlying two-body or three-body interactions used as input. Implicit in our work is the question of how far one can go within the traditional nuclear physics framework i.e., nucleons and mesons in a nonrelativistic setting. Our central goal is to carry through state-of-the-art few-body calculations that will serve as a means of determining at what point standard nuclear physics requires introduction of relativity and/or quark degrees of freedom in order to understand the phenomena in question. So far, the problems considered were mostly concerned with low- to medium-energy regimes where little evidence was found that requires going beyond the traditional approach

  11. Electromagnetic radiation optimum neutralizer

    International Nuclear Information System (INIS)

    Smirnov, Igor

    2002-01-01

    This particular article relates to subtle electrical effects, and provides some evidence of a fundamental nature on how subtle low frequency electromagnetic fields might be utilized to protect human body against harmful effects of high frequencies electromagnetic radiation. I have focused my efforts on definite polar polymer compound named EMRON which is patented in the USA. This polar polymer compound can be excited by external high frequencies electromagnetic fields to generate subtle low frequency oscillations that are beneficial for cellular life structures. This concept is based on the possibility of existence of resonance phenomenon between polar polymers and biopolymers such as proteins, nucleic acids, lipids, etc. Low frequency patterns generated by defined polar polymer compound can interact with biostructures and transmit the signals that support and improve cellular functions in the body. The mechanism of this process was confirmed by number of studies. The animal (including human) brain is affected by electromagnetic waves to the extent that production of Alpha or Theta waves can be directly induced into brain by carrying an ELF (extremely low frequency, 5-12 Hz) signal on a microwave carrier frequency. EMRON does not reduce the power of electromagnetic fields. It 'shields' the cellular structures of the body against the harmful effects of EMR. The radiation is still entering the body but the neutralizing effect of EMRON renders the radiation harmless

  12. The theory of electromagnetism

    CERN Document Server

    Jones, D S

    1964-01-01

    The Theory of the Electomagnetism covers the behavior of electromagnetic fields and those parts of applied mathematics necessary to discover this behavior. This book is composed of 11 chapters that emphasize the Maxwell's equations. The first chapter is concerned with the general properties of solutions of Maxwell's equations in matter, which has certain macroscopic properties. The succeeding chapters consider specific problems in electromagnetism, including the determination of the field produced by a variable charge, first in isolation and then in the surface distributions of an antenna. The

  13. Essentials of Computational Electromagnetics

    CERN Document Server

    Sheng, Xin-Qing

    2012-01-01

    Essentials of Computational Electromagnetics provides an in-depth introduction of the three main full-wave numerical methods in computational electromagnetics (CEM); namely, the method of moment (MoM), the finite element method (FEM), and the finite-difference time-domain (FDTD) method. Numerous monographs can be found addressing one of the above three methods. However, few give a broad general overview of essentials embodied in these methods, or were published too early to include recent advances. Furthermore, many existing monographs only present the final numerical results without specifyin

  14. Theory and computation of the matrix elements of the full interaction of the electromagnetic field with an atomic state: Application to the Rydberg and the continuous spectrum

    International Nuclear Information System (INIS)

    Komninos, Yannis; Mercouris, Theodoros; Nicolaides, Cleanthes A.

    2002-01-01

    We develop practical formulas for the calculation of the matrix elements of the interaction of the electromagnetic field with an atomic state, beyond the long-wavelength approximation. The atom-plus-field Hamiltonian is chosen to have the multipolar form, containing the electric, paramagnetic, and diamagnetic operators. The final workable expressions include the interactions to all orders and are derived by first expanding the fields in partial waves. The electric-field operator reaches a constant value as the radial variable becomes large, contrary to the result of the electric-dipole approximation (EDA) where the value of the corresponding operator increases indefinitely. Applications are given for Rydberg states of hydrogen up to n=50 and for free-free transitions in a Coulomb potential. Such matrix elements are relevant to a number of real and virtual processes occurring during laser-atom interactions. The computation is done numerically, using a combination of analytic with numerical techniques. By comparing the results of the EDA with those of the exact treatment, it is shown that the former is inadequate in such cases. This finding has repercussions on the theory and understanding of the physics of quantum systems in high-lying Rydberg levels and wave packets or in scattering states

  15. Interaction between pancreatic β cell and electromagnetic fields: A systematic study toward finding the natural frequency spectrum of β cell system.

    Science.gov (United States)

    Farashi, Sajjad

    2017-01-01

    Interaction between biological systems and environmental electric or magnetic fields has gained attention during the past few decades. Although there are a lot of studies that have been conducted for investigating such interaction, the reported results are considerably inconsistent. Besides the complexity of biological systems, the important reason for such inconsistent results may arise due to different excitation protocols that have been applied in different experiments. In order to investigate carefully the way that external electric or magnetic fields interact with a biological system, the parameters of excitation, such as intensity or frequency, should be selected purposefully due to the influence of these parameters on the system response. In this study, pancreatic β cell, the main player of blood glucose regulating system, is considered and the study is focused on finding the natural frequency spectrum of the system using modeling approach. Natural frequencies of a system are important characteristics of the system when external excitation is applied. The result of this study can help researchers to select proper frequency parameter for electrical excitation of β cell system. The results show that there are two distinct frequency ranges for natural frequency of β cell system, which consist of extremely low (or near zero) and 100-750 kHz frequency ranges. There are experimental works on β cell exposure to electromagnetic fields that support such finding.

  16. Interactions in Generalized Linear Models: Theoretical Issues and an Application to Personal Vote-Earning Attributes

    Directory of Open Access Journals (Sweden)

    Tsung-han Tsai

    2013-05-01

    Full Text Available There is some confusion in political science, and the social sciences in general, about the meaning and interpretation of interaction effects in models with non-interval, non-normal outcome variables. Often these terms are casually thrown into a model specification without observing that their presence fundamentally changes the interpretation of the resulting coefficients. This article explains the conditional nature of reported coefficients in models with interactions, defining the necessarily different interpretation required by generalized linear models. Methodological issues are illustrated with an application to voter information structured by electoral systems and resulting legislative behavior and democratic representation in comparative politics.

  17. Particles and holes equivalence for generalized seniority and the interacting boson model

    International Nuclear Information System (INIS)

    Talmi, I.

    1982-01-01

    An apparent ambiguity was recently reported in coupling either pairs of identical fermions or hole pairs. This is explained here as due to a Hamiltonian whose lowest eigenstates do not have the structure prescribed by generalized seniority. It is shown that generalized seniority eigenstates can be equivalently constructed from correlated J = 0 and J = 2 pair states of either particles or holes. The interacting boson model parameters calculated can be unambiguously interpreted and then are of real interest to the shell model basis of interacting boson model

  18. Quantum electrodynamics with nonrelativistic sources. V. Electromagnetic field correlations and intermolecular interactions between molecules in either ground or excited states

    International Nuclear Information System (INIS)

    Power, E.A.; Thirunamachandran, T.

    1993-01-01

    Spatial correlations between electromagnetic fields arising from neutral sources with electric-dipole transition moments are calculated using nonrelativistic quantum electrodynamics in the multipolar formalism. Expressions for electric-electric, magnetic-magnetic, and electric-magnetic correlation functions at two points r and r' are given for a source molecule in either a ground or an excited state. In contrast to the electric-electric and magnetic-magnetic cases there are no electric-magnetic correlations for a ground-state molecule. For an excited molecule the downward transitions contribute additional terms which have modulating factors depending on (r-r')/λ. From these correlation functions electric and magnetic energy densities are found by setting r=r'. These energy densities are then used in a response formalism to calculate intermolecular energy shifts. In the case of two ground-state molecules this leads to the Casimir-Polder potential. However, for a pair of molecules, one or both excited, there are additional terms arising from downward transitions. An important feature of these energies is that they exhibit an R -2 dependence for large intermolecular separations R. This dependence is interpreted in terms of the Poynting vector, which itself can be obtained by setting r=r' in the electric-magnetic correlation function

  19. LPIC++. A parallel one-dimensional relativistic electromagnetic particle-in-cell code for simulating laser-plasma-interaction

    International Nuclear Information System (INIS)

    Lichters, R.; Pfund, R.E.W.; Meyer-ter-Vehn, J.

    1997-08-01

    The code LPIC++ presented here, is based on a one-dimensional, electromagnetic, relativistic PIC code that has originally been developed by one of the authors during a PhD thesis at the Max-Planck-Institut fuer Quantenoptik for kinetic simulations of high harmonic generation from overdense plasma surfaces. The code uses essentially the algorithm of Birdsall and Langdon and Villasenor and Bunemann. It is written in C++ in order to be easily extendable and has been parallelized to be able to grow in power linearly with the size of accessable hardware, e.g. massively parallel machines like Cray T3E. The parallel LPIC++ version uses PVM for communication between processors. PVM is public domain software, can be downloaded from the world wide web. A particular strength of LPIC++ lies in its clear program and data structure, which uses chained lists for the organization of grid cells and enables dynamic adjustment of spatial domain sizes in a very convenient way, and therefore easy balancing of processor loads. Also particles belonging to one cell are linked in a chained list and are immediately accessable from this cell. In addition to this convenient type of data organization in a PIC code, the code shows excellent performance in both its single processor and parallel version. (orig.)

  20. The interaction of radio frequency electromagnetic fields with atmospheric water droplets and applications to aircraft ice prevention. Thesis

    Science.gov (United States)

    Hansman, R. J., Jr.

    1982-01-01

    The feasibility of computerized simulation of the physics of advanced microwave anti-icing systems, which preheat impinging supercooled water droplets prior to impact, was investigated. Theoretical and experimental work performed to create a physically realistic simulation is described. The behavior of the absorption cross section for melting ice particles was measured by a resonant cavity technique and found to agree with theoretical predictions. Values of the dielectric parameters of supercooled water were measured by a similar technique at lambda = 2.82 cm down to -17 C. The hydrodynamic behavior of accelerated water droplets was studied photograhically in a wind tunnel. Droplets were found to initially deform as oblate spheroids and to eventually become unstable and break up in Bessel function modes for large values of acceleration or droplet size. This confirms the theory as to the maximum stable droplet size in the atmosphere. A computer code which predicts droplet trajectories in an arbitrary flow field was written and confirmed experimentally. The results were consolidated into a simulation to study the heating by electromagnetic fields of droplets impinging onto an object such as an airfoil. It was determined that there is sufficient time to heat droplets prior to impact for typical parameter values. Design curves for such a system are presented.

  1. Electromagnetic study of surface enhanced Raman scattering of plasmonic-biomolecule: An interaction between nanodimer and single biomolecule

    Science.gov (United States)

    Pandey, Gyanendra Krishna; Pathak, Nilesh Kumar; Uma, R.; Sharma, R. P.

    2017-04-01

    In this article we have investigated the electromagnetic surface enhanced Raman scattering (SERS) of single biomolecule adsorbed at the surface of spherical nanodimer. The SERS mechanism has been studied using first principle approach for spherical nanodimer geometry. The coupling of plasmonic concept to biomolecule results the broadband tunable enhancement in Raman gain factor. In this observation the enhancement factor was observed around ≈ 1015. The plasmonic properties of metal nanodimer are analysed in terms of surface plasmon resonances, extinction efficiency and polarisability that have been derived under quasistatic approximation. In this paper, various facets like interdipole separation, molecule distance and size of the plasmonic nanogeometry are taken into account to analyse the Raman gain factor. We also observe that the frequency range expands sufficiently which increases the broad detectability range of the molecule which generates signal even in the outside of Raman range i.e. in between IR to UV region. Lastly, the extinction spectra and electric field profile have been evaluated at resonance wavelength 364 nm. The comparison between electrostatic approach and numerical approach (using DDA) has also been done in terms of extinction spectra.

  2. Ultra-short laser interactions with nanoparticles in different media: from electromagnetic to thermal and electrostatic effects

    Science.gov (United States)

    Itina, Tatiana E.

    2017-02-01

    Key issues of the controlled synthesis of nanoparticles and nanostructures, as well as laser-particle interactions are considered in the context of the latest applications appearing in many fields such as photonics, medicine, 3D printing, etc. The results of a multi-physics numerical study of laser interaction with nanoparticles will be presented in the presence of several environments. In particular, attention will be paid to the numerical study of laser interactions with heterogeneous materials (eg. colloidal liquids and/or nanoparticles in a dielectric medium) and the aggregation/sintering/fragmentation processes induced by ultra-short laser pulses.

  3. Electromagnetic pump

    International Nuclear Information System (INIS)

    Ito, Koji; Suetake, Norio; Aizawa, Toshie; Nakasaki, Masayoshi

    1998-01-01

    The present invention provides an electromagnetic pump suitable to a recycling pump for liquid sodium as coolants of an FBR type reactor. Namely, a stator module of the electromagnetic pump of the present invention comprises a plurality of outer laminate iron core units and outer stator modules stacked alternately in the axial direction. With such a constitution, even a long electromagnetic pump having a large number of outer stator coils can be manufactured without damaging electric insulation of the outer stator coils. In addition, the inner circumferential surface of the outer laminate iron cores is urged and brought into contact with the outer circumferential surface of the outer duct by an elastic material. With such a constitution, Joule loss heat generated in the outer stator coils and internal heat generated in the outer laminate iron cores can be released to an electroconductive fluid flowing the inner circumference of the outer duct by way of the outer duct. (I.S.)

  4. A model of the extended electron and its nonlocal electromagnetic interaction: Gauge invariance of the nonlocal theory

    International Nuclear Information System (INIS)

    Namsrai, Kh.; Nyamtseren, N.

    1994-09-01

    A model of the extended electron is constructed by using definition of the d-operation. Gauge invariance of the nonlocal theory is proved. We use the Efimov approach to describe the nonlocal interaction of quantized fields. (author). 4 refs

  5. Direction: unified theory of interactions

    International Nuclear Information System (INIS)

    Valko, P.

    1987-01-01

    Briefly characterized are the individual theories, namely, the general relativity theory, the Kaluza-Klein theory, the Weyl theory, the unified theory of electromagnetic and weak interactions, the supergravity theory, and the superstring theory. The history is recalled of efforts aimed at creating a unified theory of interactions, and future prospects are outlined. (M.D.). 2 figs

  6. Impact of electro-magnetic stabilization, small- scale turbulence and multi-scale interactions on heat transport in JET

    Science.gov (United States)

    Mantica, Paola

    2016-10-01

    Heat transport experiments in JET, based on ICRH heat flux scans and temperature modulation, have confirmed the importance of two transport mechanisms that are often neglected in modeling experimental results, but are crucial to reach agreement between theory and experiment and may be significant in ITER. The first mechanism is the stabilizing effect of the total pressure gradient (including fast ions) on ITG driven ion heat transport. Such stabilization is found in non-linear gyro-kinetic electro-magnetic simulations using GENE and GYRO, and is the explanation for the observed loss of ion stiffness in the core of high NBI-power JET plasmas. The effect was recently observed also in JET plasmas with dominant ICRH heating and small rotation, due to ICRH fast ions, which is promising for ITER. Such mechanism dominates over ExB flow shear in the core and needs to be included in quasi-linear models to increase their ability to capture the relevant physics. The second mechanism is the capability of small- scale ETG instabilities to carry a significant fraction of electron heat. A decrease in Te peaking is observed when decreasing Zeff Te/Ti, which cannot be ascribed to TEMs but is in line with ETGs. Non-linear GENE single-scale simulations of ETGs and ITG/TEMs show that the ITG/TEM electron heat flux is not enough to match experiment. TEM stiffness is also much lower than measured. In the ETG single scale simulations the external flow shear is used to saturate the ETG streamers. Multi-scale simulations are ongoing, in which the ion zonal flows are the main saturating mechanism for ETGs. These costly simulations should provide the final answer on the importance of ETG-driven electron heat flux in JET. with JET contributors [F.Romanelli, Proc.25thIAEA FEC]. Supported by EUROfusion Grant 633053.

  7. Toward a Web-Enhanced Model of Interaction in Freshman General Education History Courses

    Science.gov (United States)

    Olt, Phillip

    2018-01-01

    While American students increasingly choose to study online, most professors remain skeptical of its quality. This paper explores the perspectives of history professors at a liberal arts institution regarding their general education classes taught face-to-face (F2F) and online, focusing on interactive communication with students between the two…

  8. Interactions of Soliton Waves for a Generalized Discrete KdV Equation

    International Nuclear Information System (INIS)

    Zhou Tong; Zhu Zuo-Nong

    2017-01-01

    It is well known that soliton interactions in discrete integrable systems often possess new properties which are different from the continuous integrable systems, e.g., we found that there are such discrete solitons in a semidiscrete integrable system (the time variable is continuous and the space one is discrete) that the shorter solitary waves travel faster than the taller ones. Very recently, this kind of soliton was also observed in a full discrete generalized KdV system (the both of time and space variables are discrete) introduced by Kanki et al. In this paper, for the generalized discrete KdV (gdKdV) equation, we describe its richer structures of one-soliton solutions. The interactions of two-soliton waves to the gdKdV equation are studied. Some new features of the soliton interactions are proposed by rigorous theoretical analysis. (paper)

  9. Astronomical bounds on a cosmological model allowing a general interaction in the dark sector

    Science.gov (United States)

    Pan, Supriya; Mukherjee, Ankan; Banerjee, Narayan

    2018-06-01

    Non-gravitational interaction between two barotropic dark fluids, namely the pressureless dust and the dark energy in a spatially flat Friedmann-Lemaître-Robertson-Walker model, has been discussed. It is shown that for the interactions that are linear in terms the energy densities of the dark components and their first order derivatives, the net energy density is governed by a second-order differential equation with constant coefficients. Taking a generalized interaction, which includes a number of already known interactions as special cases, the dynamics of the universe is described for three types of the dark energy equation of state, namely that of interacting quintessence, interacting vacuum energy density, and interacting phantom. The models have been constrained using the standard cosmological probes, Supernovae Type Ia data from joint light curve analysis and the observational Hubble parameter data. Two geometric tests, the cosmographic studies, and the Om diagnostic have been invoked so as to ascertain the behaviour of the present model vis-a-vis the Λ-cold dark matter model. We further discussed the interacting scenarios taking into account the thermodynamic considerations.

  10. Gravitational scattering of electromagnetic radiation

    Science.gov (United States)

    Brooker, J. T.; Janis, A. I.

    1980-01-01

    The scattering of electromagnetic radiation by linearized gravitational fields is studied to second order in a perturbation expansion. The incoming electromagnetic radiation can be of arbitrary multipole structure, and the gravitational fields are also taken to be advanced fields of arbitrary multipole structure. All electromagnetic multipole radiation is found to be scattered by gravitational monopole and time-varying dipole fields. No case has been found, however, in which any electromagnetic multipole radiation is scattered by gravitational fields of quadrupole or higher-order multipole structure. This lack of scattering is established for infinite classes of special cases, and is conjectured to hold in general. The results of the scattering analysis are applied to the case of electromagnetic radiation scattered by a moving mass. It is shown how the mass and velocity may be determined by a knowledge of the incident and scattered radiation.

  11. Investigations of the structure and electromagnetic interactions of few-body systems. Progress report, 1 January 1980-1 October 1980

    Energy Technology Data Exchange (ETDEWEB)

    Harper, E P; Lehman, D R; Prats, F

    1980-11-07

    Considerable progress has been made on the long-range problems described in the original proposal document (1 February 1979 to 31 January 1980) and on the shorter-range problems described in the last renewal proposal (1 February 1980 to 31 January 1981). This progress concerns few-body structure problems (e.g., the existence of isobar components in /sup 3/H, predictions of few-body-hypernuclei properties as a test of hyperon-nucleon interactions, investigation of the A = 6 ground states with exact three-body calculations, and the relation of triton D-state properties to the deuteron's D-state percentage) and electromagnetic properties and interactions of few-body nuclei (e.g., Coulomb effects in calculating and measuring asymptotic normalization constants, and ..gamma.. + /sup 3/He breakup reaction mechanisms at intermediate energies). Descriptions of the progress made indicate where each subject stands at present, and emphasize the significant results obtained. A publication list is attached.

  12. Comparison of interacting boson-fermion model with spin-dependent generalized collective model for the j=3/2

    International Nuclear Information System (INIS)

    Baktybaev, K.; Koilyk, N.; Ramankulov, K.

    2006-01-01

    Full text: Collective Schrodinger equations are applied to describe low-energy spectra of even-even nuclei [1]. Spectra for even-odd nuclei are calculated by coupling the single particle degrees of freedom to the collective degree of freedom of the core nucleus, which is of even-even type. The collective spin has a value of 3/2. This leads to the assumption that the linearized equation may be applied to describe nuclei with spin 3/2 in the ground state. Good description of the low energy spectra and electromagnetic transition probabilities can be obtained only with introduction of spin-dependent potentials, which apart from coordinates and momenta also depend on the matrices of the Clifford algebra arising in the linearization,. The interacting boson-fermion models (IBFM) [2] represent another approach to describe spectra of even-odd nuclei. For even-odd nuclei with spin 3/2 in the ground state one uses so-called j=3/2 - IBFM, which is also denoted as the U B (6)xU F (4) IBFM. In this paper we establish the relation between the matrices of the Clifford algebra, which arise in the linearization procedure, and the fermion operators of the j=3/2 IBFM. This allows us to establish a connection between the j=3/2 IBFM and spin dependent generalized collective model (SGCM). The results of the SGCM for Ir and Au nuclei are presented and compared with the results of the j=3/2 IBFM with a dynamical spin symmetry [3] present. In this respect we could apply the linearized collective Schrodinger equation and IBFM with arbitrary spin to all other even-odd nuclei. (author)

  13. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Hasse, Stina

    2015-01-01

    Electromagnetic Landscape demonstrates in direct, tangible and immediate ways effects of the disruption of the familiar. An ubiquitous technological medium, FM radio, is turned into an alien and unfamiliar one. Audience participation, the environment, radio signals and noise create a site...

  14. On a generalized Dirac oscillator interaction for the nonrelativistic limit 3 D generalized SUSY model oscillator Hamiltonian of Celka and Hussin

    International Nuclear Information System (INIS)

    Jayaraman, Jambunatha; Lima Rodrigues, R. de

    1994-01-01

    In the context of the 3 D generalized SUSY model oscillator Hamiltonian of Celka and Hussin (CH), a generalized Dirac oscillator interaction is studied, that leads, in the non-relativistic limit considered for both signs of energy, to the CH's generalized 3 D SUSY oscillator. The relevance of this interaction to the CH's SUSY model and the SUSY breaking dependent on the Wigner parameter is brought out. (author). 6 refs

  15. The law of electromagnetic force

    Directory of Open Access Journals (Sweden)

    V.J. Kutkovetskyy

    2014-06-01

    Full Text Available Calculation peculiarities for Lorentz force, Ampere force, interaction of parallel electric currents, and the moment of electrical machines are analyzed. They have exceptions on application, and they are the rules which result from the law of electromagnetic force as coordinate derivative of the operating magnetic flow. An addition to the direction of electromagnetic force action is proposed. Standards of salient-pole electrical machine designing are considered.

  16. An elementary introduction to Yang-Mills theories and to their applications to the weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Maiani, L.

    1976-01-01

    In these lecture notes, the author deals exclusively with a gauge theory of weak and e.m. processes. The aim is to give an elementary introduction to the subject by discussing the general underlying ideas, and the way these ideas can be put to work in a concrete theory, based on the gauge group SU(2)X(1). (Auth.)

  17. Nonlinear propagation of intense electromagnetic waves in weakly-ionized plasmas

    International Nuclear Information System (INIS)

    Shukla, P.K.

    1993-01-01

    The nonlinear propagation of intense electromagnetic waves in weakly-ionized plasmas is considered. Stimulated scattering mechanisms involving electromagnetic and acoustic waves in an unmagnetized plasma are investigated. The growth rate and threshold for three-wave decay interactions as well as modulational and filamentation instabilities are presented. Furthermore, the electromagnetic wave modulation theory is generalized for weakly ionized collisional magnetoplasmas. Here, the radiation envelope is generally governed by a nonlinear Schroedinger equation. Accounting for the dependence of the attachment frequency on the radiation intensity, ponderomotive force, as well as the differential Joule heating nonlinearity, the authors derive the equations for the nonthermal electron density and temperature perturbations. The various nonlinear terms in the electron motion are compared. The problems of self-focusing and wave localization are discussed. The relevance of the investigation to ionospheric modification by powerful electromagnetic waves is pointed out

  18. A hierarchical generalization of the acoustic reciprocity theorem involving higher-order derivatives and interaction quantities.

    Science.gov (United States)

    Lin, Ju; Li, Jie; Li, Xiaolei; Wang, Ning

    2016-10-01

    An acoustic reciprocity theorem is generalized, for a smoothly varying perturbed medium, to a hierarchy of reciprocity theorems including higher-order derivatives of acoustic fields. The standard reciprocity theorem is the first member of the hierarchy. It is shown that the conservation of higher-order interaction quantities is related closely to higher-order derivative distributions of perturbed media. Then integral reciprocity theorems are obtained by applying Gauss's divergence theorem, which give explicit integral representations connecting higher-order interactions and higher-order derivative distributions of perturbed media. Some possible applications to an inverse problem are also discussed.

  19. Promoting Active Learning in Calculus and General Physics through Interactive and Media-Enhanced Lectures

    Directory of Open Access Journals (Sweden)

    Guoqing Tang

    2004-02-01

    Full Text Available In this paper we present an approach of incorporating interactive and media-enhanced lectures to promote active learning in Calculus and General Physics courses. The pedagogical practice of using interactive techniques in lectures to require "heads-on" and "hands-on" learning, and involve students more as active participants than passive receivers is a part of academic curricular reform efforts undertaken currently by the mathematics, physics and chemistry departments at North Carolina A&T State University under the NSF funded project "Talent-21: Gateway for Advancing Science and Mathematics Talents."

  20. Transformation electromagnetics and metamaterials fundamental principles and applications

    CERN Document Server

    Werner, Douglas H

    2013-01-01

    Transformation electromagnetics is a systematic design technique for optical and electromagnetic devices that enables novel wave-material interaction properties. The associated metamaterials technology for designing and realizing optical and electromagnetic devices can control the behavior of light and electromagnetic waves in ways that have not been conventionally possible. The technique is credited with numerous novel device designs, most notably the invisibility cloaks, perfect lenses and a host of other remarkable devices.Transformation Electromagnetics and Metamaterials: Fundamental Princ

  1. General and specific lipid-protein interactions in Na,K-ATPase.

    Science.gov (United States)

    Cornelius, F; Habeck, M; Kanai, R; Toyoshima, C; Karlish, S J D

    2015-09-01

    The molecular activity of Na,K-ATPase and other P2 ATPases like Ca(2+)-ATPase is influenced by the lipid environment via both general (physical) and specific (chemical) interactions. Whereas the general effects of bilayer structure on membrane protein function are fairly well described and understood, the importance of the specific interactions has only been realized within the last decade due particularly to the growing field of membrane protein crystallization, which has shed new light on the molecular details of specific lipid-protein interactions. It is a remarkable observation that specific lipid-protein interactions seem to be evolutionarily conserved, and conformations of specifically bound lipids at the lipid-protein surface within the membrane are similar in crystal structures determined with different techniques and sources of the protein, despite the rather weak lipid-protein interaction energy. Studies of purified detergent-soluble recombinant αβ or αβFXYD Na,K-ATPase complexes reveal three separate functional effects of phospholipids and cholesterol with characteristic structural selectivity. The observations suggest that these three effects are exerted at separate binding sites for phophatidylserine/cholesterol (stabilizing), polyunsaturated phosphatidylethanolamine (stimulatory), and saturated PC or sphingomyelin/cholesterol (inhibitory), which may be located within three lipid-binding pockets identified in recent crystal structures of Na,K-ATPase. The findings point to a central role of direct and specific interactions of different phospholipids and cholesterol in determining both stability and molecular activity of Na,K-ATPase and possible implications for physiological regulation by membrane lipid composition. This article is part of a special issue titled "Lipid-Protein Interactions." Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Differential forms on electromagnetic networks

    CERN Document Server

    Balasubramanian, N V; Sen Gupta, D P

    2013-01-01

    Differential Forms on Electromagnetic Networks deals with the use of combinatorial techniques in electrical circuit, machine analysis, and the relationship between circuit quantities and electromagnetic fields. The monograph is also an introduction to the organization of field equations by the methods of differential forms. The book covers topics such as algebraic structural relations in an electric circuit; mesh and node-pair analysis; exterior differential structures; generalized Stoke's theorem and tensor analysis; and Maxwell's electromagnetic equation. Also covered in the book are the app

  3. Hartree-Fock-Bogolubov approximation in the models with general four-fermion interaction

    International Nuclear Information System (INIS)

    Bogolubov, N.N. Jr.; Soldatov, A.V.

    1995-12-01

    The foundation of this work was established by the lectures of Prof. N.N. Bogolubov (senior) written in the beginning of 1990. We should like to develop some of his ideas connected with Hartree-Fock-Bogolubov method and to show how this approximation works in connection with general equations for Green's functions with source terms for sufficiently general model Hamiltonian of four-fermion interaction type and how, for example, to get some results of superconductivity theory by means of this method. (author). 5 refs

  4. Lie symmetries for charged particles in the presence of a general electromagnetic field; Simetrias de Lie para particula carregada na presenca de campo eletromagnetico geral

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros Ritter, Oswaldo de

    1991-10-01

    We discuss the Lie method and apply it to differential equations obtaining their symmetries. We also discuss methods of how to obtain first integrals from these symmetries. We apply these methods to some interesting physical problems, all of them involving charged particles in electromagnetic fields. (author). 77 refs.

  5. Description of spectrum and electromagnetic transitions in 94Mo through the proton-neutron interacting boson model

    Science.gov (United States)

    Mu, ChengFu; Zhang, DaLi

    2018-01-01

    We investigated the properties of low-lying states in 94Mo within the framework of the proton-neutron interacting boson model (IBM-2), with special focus on the characteristics of mixed-symmetry states. We calculated level energies and M1 and E2 transition strengths. The IBM-2 results agree with the available quantitative and qualitative experimental data on 94Mo. The properties of mixed-symmetry states can be well described by IBM-2 given that the energy of the d proton boson is different from that of the neutron boson, especially for the transition of B( M1; 4 2 + → 4 1 + ).

  6. Detecting treatment-subgroup interactions in clustered data with generalized linear mixed-effects model trees.

    Science.gov (United States)

    Fokkema, M; Smits, N; Zeileis, A; Hothorn, T; Kelderman, H

    2017-10-25

    Identification of subgroups of patients for whom treatment A is more effective than treatment B, and vice versa, is of key importance to the development of personalized medicine. Tree-based algorithms are helpful tools for the detection of such interactions, but none of the available algorithms allow for taking into account clustered or nested dataset structures, which are particularly common in psychological research. Therefore, we propose the generalized linear mixed-effects model tree (GLMM tree) algorithm, which allows for the detection of treatment-subgroup interactions, while accounting for the clustered structure of a dataset. The algorithm uses model-based recursive partitioning to detect treatment-subgroup interactions, and a GLMM to estimate the random-effects parameters. In a simulation study, GLMM trees show higher accuracy in recovering treatment-subgroup interactions, higher predictive accuracy, and lower type II error rates than linear-model-based recursive partitioning and mixed-effects regression trees. Also, GLMM trees show somewhat higher predictive accuracy than linear mixed-effects models with pre-specified interaction effects, on average. We illustrate the application of GLMM trees on an individual patient-level data meta-analysis on treatments for depression. We conclude that GLMM trees are a promising exploratory tool for the detection of treatment-subgroup interactions in clustered datasets.

  7. Local thermodynamics and the generalized Gibbs-Duhem equation in systems with long-range interactions.

    Science.gov (United States)

    Latella, Ivan; Pérez-Madrid, Agustín

    2013-10-01

    The local thermodynamics of a system with long-range interactions in d dimensions is studied using the mean-field approximation. Long-range interactions are introduced through pair interaction potentials that decay as a power law in the interparticle distance. We compute the local entropy, Helmholtz free energy, and grand potential per particle in the microcanonical, canonical, and grand canonical ensembles, respectively. From the local entropy per particle we obtain the local equation of state of the system by using the condition of local thermodynamic equilibrium. This local equation of state has the form of the ideal gas equation of state, but with the density depending on the potential characterizing long-range interactions. By volume integration of the relation between the different thermodynamic potentials at the local level, we find the corresponding equation satisfied by the potentials at the global level. It is shown that the potential energy enters as a thermodynamic variable that modifies the global thermodynamic potentials. As a result, we find a generalized Gibbs-Duhem equation that relates the potential energy to the temperature, pressure, and chemical potential. For the marginal case where the power of the decaying interaction potential is equal to the dimension of the space, the usual Gibbs-Duhem equation is recovered. As examples of the application of this equation, we consider spatially uniform interaction potentials and the self-gravitating gas. We also point out a close relationship with the thermodynamics of small systems.

  8. Modeling Dzyaloshinskii-Moriya Interaction at Transition Metal Interfaces: Constrained Moment versus Generalized Bloch Theorem

    KAUST Repository

    Dong, Yao-Jun; Belabbes, Abderrezak; Manchon, Aurelien

    2017-01-01

    Dzyaloshinskii-Moriya interaction (DMI) at Pt/Co interfaces is investigated theoretically using two different first principles methods. The first one uses the constrained moment method to build a spin spiral in real space, while the second method uses the generalized Bloch theorem approach to construct a spin spiral in reciprocal space. We show that although the two methods produce an overall similar total DMI energy, the dependence of DMI as a function of the spin spiral wavelength is dramatically different. We suggest that long-range magnetic interactions, that determine itinerant magnetism in transition metals, are responsible for this discrepancy. We conclude that the generalized Bloch theorem approach is more adapted to model DMI in transition metal systems, where magnetism is delocalized, while the constrained moment approach is mostly applicable to weak or insulating magnets, where magnetism is localized.

  9. Modeling Dzyaloshinskii-Moriya Interaction at Transition Metal Interfaces: Constrained Moment versus Generalized Bloch Theorem

    KAUST Repository

    Dong, Yao-Jun

    2017-10-29

    Dzyaloshinskii-Moriya interaction (DMI) at Pt/Co interfaces is investigated theoretically using two different first principles methods. The first one uses the constrained moment method to build a spin spiral in real space, while the second method uses the generalized Bloch theorem approach to construct a spin spiral in reciprocal space. We show that although the two methods produce an overall similar total DMI energy, the dependence of DMI as a function of the spin spiral wavelength is dramatically different. We suggest that long-range magnetic interactions, that determine itinerant magnetism in transition metals, are responsible for this discrepancy. We conclude that the generalized Bloch theorem approach is more adapted to model DMI in transition metal systems, where magnetism is delocalized, while the constrained moment approach is mostly applicable to weak or insulating magnets, where magnetism is localized.

  10. Electromagnetic shielding

    International Nuclear Information System (INIS)

    Tzeng, Wen-Shian V.

    1991-01-01

    Electromagnetic interference (EMI) shielding materials are well known in the art in forms such as gaskets, caulking compounds, adhesives, coatings and the like for a variety of EMI shielding purposes. In the past, where high shielding performance is necessary, EMI shielding has tended to use silver particles or silver coated copper particles dispersed in a resin binder. More recently, aluminum core silver coated particles have been used to reduce costs while maintaining good electrical and physical properties. (author). 8 figs

  11. The interaction of circularly polarised electromagnetic waves with a plasma; Interaction d'ondes electromagnetiques a polarisation circulaire avec un plasma

    Energy Technology Data Exchange (ETDEWEB)

    Consoli, T; Legardeur, R; Slama, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The interaction of left and right handed circularly polarised waves with a plasma are studied. The individual trajectories of charges of both signs are traced with a analogical simulator. Applications to plasma heating and diagnostic are deduced. (author) [French] On etudie l'interaction des ondes a polarisation circulaire droite ou gauche avec un plasma. Les trajectoires individuelles des charges sont tracees a l'aide d'un dispositif analogique. On en deduit les applications au chauffage d'un plasma et a la mesure de ses parametres caracteristiques. (auteur)

  12. Studying emotion theories through connectivity analysis: Evidence from generalized psychophysiological interactions and graph theory.

    Science.gov (United States)

    Huang, Yun-An; Jastorff, Jan; Van den Stock, Jan; Van de Vliet, Laura; Dupont, Patrick; Vandenbulcke, Mathieu

    2018-05-15

    Psychological construction models of emotion state that emotions are variable concepts constructed by fundamental psychological processes, whereas according to basic emotion theory, emotions cannot be divided into more fundamental units and each basic emotion is represented by a unique and innate neural circuitry. In a previous study, we found evidence for the psychological construction account by showing that several brain regions were commonly activated when perceiving different emotions (i.e. a general emotion network). Moreover, this set of brain regions included areas associated with core affect, conceptualization and executive control, as predicted by psychological construction models. Here we investigate directed functional brain connectivity in the same dataset to address two questions: 1) is there a common pathway within the general emotion network for the perception of different emotions and 2) if so, does this common pathway contain information to distinguish between different emotions? We used generalized psychophysiological interactions and information flow indices to examine the connectivity within the general emotion network. The results revealed a general emotion pathway that connects neural nodes involved in core affect, conceptualization, language and executive control. Perception of different emotions could not be accurately classified based on the connectivity patterns from the nodes of the general emotion pathway. Successful classification was achieved when connections outside the general emotion pathway were included. We propose that the general emotion pathway functions as a common pathway within the general emotion network and is involved in shared basic psychological processes across emotions. However, additional connections within the general emotion network are required to classify different emotions, consistent with a constructionist account. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Engineering electromagnetics

    CERN Document Server

    Ida, Nathan

    2015-01-01

    This book provides students with a thorough theoretical understanding of electromagnetic field equations and it also treats a large number of applications. The text is a comprehensive two-semester textbook. The work treats most topics in two steps – a short, introductory chapter followed by a second chapter with in-depth extensive treatment; between 10 to 30 applications per topic; examples and exercises throughout the book; experiments, problems  and summaries.   The new edition includes: updated end of chapter problems; a new introduction to electromagnetics based on behavior of charges; a new section on units; MATLAB tools for solution of problems and demonstration of subjects; most chapters include a summary. The book is an undergraduate textbook at the Junior level, intended for required classes in electromagnetics. It is written in simple terms with all details of derivations included and all steps in solutions listed. It requires little beyond basic calculus and can be used for self-study. The weal...

  14. INTERACTIONAL-GNOSTIC COMPONENT IN THE STRUCTURE OF GENERAL HUMANITARIAN BASIS OF EDUCATION

    OpenAIRE

    Tamara M. ELKANOVA

    2015-01-01

    The interactional-gnostic component of author's conceptual and theoretical model of general humanitarian basis of education provides integration at the level of development of different in the ontologic ways of knowledge of the world, training in associative and figurative thinking, translation from objective external language into internal language of figurative and conceptual models of reality, strengthening of attention to axiological notional content of the received knowledge, formation o...

  15. Ligand-regulated peptides: a general approach for modulating protein-peptide interactions with small molecules.

    Science.gov (United States)

    Binkowski, Brock F; Miller, Russell A; Belshaw, Peter J

    2005-07-01

    We engineered a novel ligand-regulated peptide (LiRP) system where the binding activity of intracellular peptides is controlled by a cell-permeable small molecule. In the absence of ligand, peptides expressed as fusions in an FKBP-peptide-FRB-GST LiRP scaffold protein are free to interact with target proteins. In the presence of the ligand rapamycin, or the nonimmunosuppressive rapamycin derivative AP23102, the scaffold protein undergoes a conformational change that prevents the interaction of the peptide with the target protein. The modular design of the scaffold enables the creation of LiRPs through rational design or selection from combinatorial peptide libraries. Using these methods, we identified LiRPs that interact with three independent targets: retinoblastoma protein, c-Src, and the AMP-activated protein kinase. The LiRP system should provide a general method to temporally and spatially regulate protein function in cells and organisms.

  16. Higgs exotic decays in general NMSSM with self-interacting dark matter

    Science.gov (United States)

    Wang, Wenyu; Zhang, Mengchao; Zhao, Jun

    2018-04-01

    Under current LHC and dark matter constraints, the general NMSSM can have self-interacting dark matter to explain the cosmological small structure. In this scenario, the dark matter is the light singlino-like neutralino (χ) which self-interacts through exchanging the light singlet-like scalars (h1,a1). These light scalars and neutralinos inevitably interact with the 125 GeV SM-like Higgs boson (hSM), which cause the Higgs exotic decays hSM → h1h1, a1a1, χχ. We first demonstrate the parameter space required by the explanation of the cosmological small structure and then display the Higgs exotic decays. We find that in such a parameter space the Higgs exotic decays can have branching ratios of a few percent, which should be accessible in the future e+e‑ colliders.

  17. Multiforms, dyadics, and electromagnetic media

    CERN Document Server

    Lindell, Ismo V

    2015-01-01

    This book applies the four-dimensional formalism with an extended toolbox of operation rules, allowing readers to define more general classes of electromagnetic media and to analyze EM waves that can exist in them. End-of-chapter exercises. Formalism allows readers to find novel classes of media. Covers various properties of electromagnetic media in terms of which they can be set in different classes.

  18. Electromagnetic fields of Nanometer electromagnetic waves and X-ray. New frontiers of electromagnetic wave engineering

    International Nuclear Information System (INIS)

    2009-01-01

    The investigating committee aimed at research on electromagnetic fields in functional devices and X-ray fibers for efficient coherent X-ray generation and their material science, high-precision manufacturing, X-ray microscope, application to medical and information communication technologies, such as interaction between material and nanometer electromagnetic waves of radiated light and X-ray, interaction between microwaves and particle beams, theory and design of high-frequency waveguides for resonator and accelerator, from January 2003 to December 2005. In this report, we describe our research results, in particular, on the topics of synchrotron radiation and Cherenkov radiation, Kyushu synchrotron light source and its technology, nanometer electromagnetic fields in optical region, process of interaction between evanescent waves and near-field light, orthogonal relation of electromagnetic fields including evanescent waves in dispersive dielectrics, optical amplification using electron beam, nanometer electromagnetic fields in focusing waveguide lens device with curved facets, electromagnetic fields in nanometer photonic crystal waveguide consisting of atoms, X-ray scattering and absorption I bio-material for image diagnosis. (author)

  19. Impact of generalized Yukawa interactions on the lower Higgs-mass bound

    Energy Technology Data Exchange (ETDEWEB)

    Gies, Holger [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany); Friedrich-Schiller-Universitaet Jena, Abbe Center of Photonics, Jena (Germany); Helmholtz-Institut Jena, Jena (Germany); Sondenheimer, Rene [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany); Warschinke, Matthias [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany); Chiba University, Department of Physics, Graduate School of Science, Chiba (Japan)

    2017-11-15

    We investigate the impact of operators of higher canonical dimension on the lower Higgs-mass consistency bound by means of generalized Higgs-Yukawa interactions. Analogously to higher-order operators in the bare Higgs potential in an effective field theory approach, the inclusion of higher-order Yukawa interactions, e.g., φ{sup 3} anti ψψ, leads to a diminishing of the lower Higgs-mass bound and thus to a shift of the scale of new physics towards larger scales by a few orders of magnitude without introducing a metastability in the effective Higgs potential. We observe that similar renormalization group mechanisms near the weak-coupling fixed point are at work in both generalizations of the microscopic action. Thus, a combination of higher-dimensional operators with generalized Higgs as well as Yukawa interactions does not lead to an additive shift of the lower mass bound, but it relaxes the consistency bounds found recently only slightly. On the method side, we clarify the convergence properties of different projection and expansion schemes for the Yukawa potential used in the functional renormalization group literature so far. (orig.)

  20. General two-species interacting Lotka-Volterra system: Population dynamics and wave propagation

    Science.gov (United States)

    Zhu, Haoqi; Wang, Mao-Xiang; Lai, Pik-Yin

    2018-05-01

    The population dynamics of two interacting species modeled by the Lotka-Volterra (LV) model with general parameters that can promote or suppress the other species is studied. It is found that the properties of the two species' isoclines determine the interaction of species, leading to six regimes in the phase diagram of interspecies interaction; i.e., there are six different interspecific relationships described by the LV model. Four regimes allow for nontrivial species coexistence, among which it is found that three of them are stable, namely, weak competition, mutualism, and predator-prey scenarios can lead to win-win coexistence situations. The Lyapunov function for general nontrivial two-species coexistence is also constructed. Furthermore, in the presence of spatial diffusion of the species, the dynamics can lead to steady wavefront propagation and can alter the population map. Propagating wavefront solutions in one dimension are investigated analytically and by numerical solutions. The steady wavefront speeds are obtained analytically via nonlinear dynamics analysis and verified by numerical solutions. In addition to the inter- and intraspecific interaction parameters, the intrinsic speed parameters of each species play a decisive role in species populations and wave properties. In some regimes, both species can copropagate with the same wave speeds in a finite range of parameters. Our results are further discussed in the light of possible biological relevance and ecological implications.

  1. Dynamics of a trapped two-level and three-level atom interacting with classical electromagnetic field

    International Nuclear Information System (INIS)

    Ray, Aditi

    2004-01-01

    The dynamics of a two-level atom driven by a single laser beam and three-level atom (Lambda configuration) irradiated by two laser beams are studied taking into account of the quantized center-of-mass motion of the atom. It is shown that the trapped atom system under appropriate resonance condition exhibits the large time-scale revivals when the index of the vibrational sideband responsible for the atomic electronic transition is greater than unity. The revival times are shown to be dependent on the initial number of vibrational excitations and the magnitude of the Lamb-Dicke parameter. The sub-Poissonian statistics in vibrational quantum number is observed at certain time intervals. The minimum time of interaction for which the squeezed states of motional quadrature are generated is found to be decreasing with the increase in the Lamb-Dicke parameter

  2. Coexistence of spherical and deformed states in nuclei in the Z = 50 region; and the interaction of nuclei with electromagnetic fields in crystals

    International Nuclear Information System (INIS)

    Shroy, R.E. Jr.

    1976-01-01

    By applying the techniques of γ ray spectroscopy to γ rays produced in the decay of nuclear states populated in heavy-ion reactions, the following studies were performed: (1) High-spin states in 113 115 117 119 Sb and 125 127 I were investigated. The states were populated via the ( 6 Li,3n) reaction. Information on the energies, spins, decay modes, lifetimes, and electromagnetic moments was obtained for states up to a typical maximum spin of 25/2. The states in the Sb (Z = 51) and I (Z = 53) nuclei are of interest because of the nearness of the Z = 50 closed proton shell. (2) Experiments were performed to investigate the possibility of using the time differential perturbed angular distribution method to measure quadrupole moments of isomers populated in heavy-ion reactions. First, the previously known quadrupole interaction frequency of the 9/2 1 + state of 69 Ge in Zn was measured, with the state populated via the (α,n) and ( 7 Li,pn) reactions. Next, the quadrupole interaction frequency of the 9/2 1 + state of 73 As was measured in Zn using the ( 7 Li,2n) reaction. A value e 2 Qq/h = 20.2 +- 0.4 MHz was obtained. (3) The destruction of nuclear alignment by lattice defects was also studied for Sb nuclei in a Cd lattice by measuring the anisotropy of γ rays emitted in the decay of an isomer in 115 Sb as a function of temperature. The states were initially aligned when produced in a heavy-ion reaction. As the temperature of the target was increased from approximately 420 0 K to approximately 470 0 K, the anisotrophy was found to increase from zero to the maximum value expected. This can be interpreted in terms of trapping and detrapping of defects by the Sb impurities

  3. Intersegment interactions and helix-coil transition within the generalized model of polypeptide chains approach

    Science.gov (United States)

    Badasyan, A. V.; Hayrapetyan, G. N.; Tonoyan, Sh. A.; Mamasakhlisov, Y. Sh.; Benight, A. S.; Morozov, V. F.

    2009-09-01

    The generalized model of polypeptide chains is extended to describe the helix-coil transition in a system comprised of two chains interacting side-by-side. The Hamiltonian of the model takes into account four possible types of interactions between repeated units of the two chains, i.e., helix-helix, helix-coil, coil-helix, and coil-coil. Analysis reveals when the energy Ihh+Icc of (h-h, c-c) interactions overwhelms the energy Ihc+Ich of mixed (h-c, c-h) interactions, the correlation length rises substantially, resulting in narrowing of the transition interval. In the opposite case, when Ihh+Iccinteractions from the same theoretical perspective.

  4. Signal discrimination of ULF electromagnetic data with using singular spectrum analysis – an attempt to detect train noise

    OpenAIRE

    Saito, S.; Kaida, D.; Hattori, K.; Febriani, F.; Yoshino, C.

    2011-01-01

    Electromagnetic phenomena associated with crustal activities have been reported in a wide frequency range (DC-HF). In particular, ULF electromagnetic phenomena are the most promising among them because of the deeper skin depth. However, ULF geoelctromagnetic data are a superposition of signals of different origins. They originated from interactions between the geomagnetic field and the solar wind, leak current by a DC-driven train (train noise), precipitation, and so on. In general, the inten...

  5. Motion model for a charged particle in a plasma during the interaction of an electromagnetic pulse elliptically polarized propagating in the direction of a static and homogeneous magnetic field

    International Nuclear Information System (INIS)

    Gomez R, F.; Ondarza R, R.

    2004-01-01

    An analytic model is presented for the description of the motion of a charged particle in the interaction of an elliptically electromagnetic pulse polarized propagating along a static and homogeneous external magnetic field in a plasma starting from the force equation. The method allows to express the solution in terms of the invariant phase, obtaining differential equations for the trajectory of the accelerated particle by means of an electromagnetic pulse of arbitrary and modulated width by an encircling Gaussian. The numerical solutions reported in this work can find varied applications, for example in the physics of the interaction laser-plasma, in the acceleration of particles, in hot plasma and in radioactive effects. (Author)

  6. Model of the motion of a charged particle into a plasma during the interaction of an electromagnetic pulse elliptically polarized propagating in the direction of a static and homogeneous magnetic field

    International Nuclear Information System (INIS)

    Gomez R, F.; Ondarza R, R.

    2004-01-01

    An analytical model for the description of the movement of a charged particle in the interaction of an electromagnetic pulse elliptically polarized propagating along of a static and homogeneous external magnetic field in a plasma starting from the force equation is presented. The method allows to express the solution in terms of the invariant phase, obtaining differential equations for the trajectory of the accelerated particle by means of an electromagnetic pulse of arbitrary amplitude and modulated by an encircling Gaussian. The numerical solutions reported in this work can find varied applications, for example in the physics of the interaction laser-plasma, in the acceleration of particles, in hot plasma and in radiative effects. (Author)

  7. Histories electromagnetism

    International Nuclear Information System (INIS)

    Burch, Aidan

    2004-01-01

    Working within the HPO (History Projection Operator) Consistent Histories formalism, we follow the work of Savvidou on (scalar) field theory [J. Math. Phys. 43, 3053 (2002)] and that of Savvidou and Anastopoulos on (first-class) constrained systems [Class. Quantum Gravt. 17, 2463 (2000)] to write a histories theory (both classical and quantum) of Electromagnetism. We focus particularly on the foliation-dependence of the histories phase space/Hilbert space and the action thereon of the two Poincare groups that arise in histories field theory. We quantize in the spirit of the Dirac scheme for constrained systems

  8. Testing for constant nonparametric effects in general semiparametric regression models with interactions

    KAUST Repository

    Wei, Jiawei

    2011-07-01

    We consider the problem of testing for a constant nonparametric effect in a general semi-parametric regression model when there is the potential for interaction between the parametrically and nonparametrically modeled variables. The work was originally motivated by a unique testing problem in genetic epidemiology (Chatterjee, et al., 2006) that involved a typical generalized linear model but with an additional term reminiscent of the Tukey one-degree-of-freedom formulation, and their interest was in testing for main effects of the genetic variables, while gaining statistical power by allowing for a possible interaction between genes and the environment. Later work (Maity, et al., 2009) involved the possibility of modeling the environmental variable nonparametrically, but they focused on whether there was a parametric main effect for the genetic variables. In this paper, we consider the complementary problem, where the interest is in testing for the main effect of the nonparametrically modeled environmental variable. We derive a generalized likelihood ratio test for this hypothesis, show how to implement it, and provide evidence that our method can improve statistical power when compared to standard partially linear models with main effects only. We use the method for the primary purpose of analyzing data from a case-control study of colorectal adenoma.

  9. Generalized Superconductivity. Generalized Levitation

    International Nuclear Information System (INIS)

    Ciobanu, B.; Agop, M.

    2004-01-01

    In the recent papers, the gravitational superconductivity is described. We introduce the concept of generalized superconductivity observing that any nongeodesic motion and, in particular, the motion in an electromagnetic field, can be transformed in a geodesic motion by a suitable choice of the connection. In the present paper, the gravitoelectromagnetic London equations have been obtained from the generalized Helmholtz vortex theorem using the generalized local equivalence principle. In this context, the gravitoelectromagnetic Meissner effect and, implicitly, the gravitoelectromagnetic levitation are given. (authors)

  10. General theory of the long-range interactions in protein folding

    International Nuclear Information System (INIS)

    Namiot, V.A.; Batyanovskii, A.V.; Filatov, I.V.; Tumanyan, V.G.; Esipova, N.G.

    2011-01-01

    The process of the globular structure formation from a long molecular chain is examined in a general sense. In the course of this process various regions of the chain interact with each other. The bonds formed during this process are classified as native and non-native ones. Native bonds are formed in native globular structure. All other bonds are 'incorrect' (non-native). It is demonstrated that the globule formation can occur actually without production and subsequent decay of non-native contacts. The proposed model allows to avoid a search of numerous non-native variants since long-distance interactions with a high selectivity take place between the chain regions that form native bonds. The presence of these interactions prompts the chain regions which yield native contacts start to draw together and to interact. The databank data analysis shows that the developed model can be applied not only to the abstract structures but also to real polypeptide chains which are able to form both globular structures and helical fibrils. -- Highlights: → The process of the globular structure formation from a long molecular chain is examined. → It is shown that the globule formation can occur without production of non-native contacts. → The proposed model allows to avoid a search of non-native variants since long-distance interactions with a high selectivity. → This interaction takes place between the chain regions that form native bonds. → The databank data analysis shows that the developed model can be applied to real polypeptide chains.

  11. Interaction Effects of Season of Birth and Cytokine Genes on Schizotypal Traits in the General Population

    Directory of Open Access Journals (Sweden)

    Margarita V. Alfimova

    2017-01-01

    Full Text Available Literature suggests that the effect of winter birth on vulnerability to schizophrenia might be mediated by increased expression of proinflammatory cytokines due to prenatal infection and its inadequate regulation by anti-inflammatory factors. As the response of the immune system depends on genotype, this study assessed the interaction effects of cytokine genes and season of birth (SOB on schizotypy measured with the Schizotypal Personality Questionnaire (SPQ-74. We searched for associations of IL1B rs16944, IL4 rs2243250, and IL-1RN VNTR polymorphisms, SOB, and their interactions with the SPQ-74 total score in a sample of 278 healthy individuals. A significant effect of the IL4 X SOB interaction was found, p=0.007 and η2=0.028. We confirmed this effect using an extended sample of 373 individuals. Homozygotes CC born in winter showed the highest SPQ total score and differed significantly from winter-born T allele carriers, p=0.049. This difference was demonstrated for cognitive-perceptual and disorganized but not interpersonal dimensions. The findings are consistent with the hypothesis that the cytokine genes by SOB interaction can influence variability of schizotypal traits in the general population. The IL4 T allele appeared to have a protective effect against the development of positive and disorganized schizotypal traits in winter-born individuals.

  12. Interaction Effects of Season of Birth and Cytokine Genes on Schizotypal Traits in the General Population.

    Science.gov (United States)

    Alfimova, Margarita V; Korovaitseva, Galina I; Lezheiko, Tatyana V; Golimbet, Vera E

    2017-01-01

    Literature suggests that the effect of winter birth on vulnerability to schizophrenia might be mediated by increased expression of proinflammatory cytokines due to prenatal infection and its inadequate regulation by anti-inflammatory factors. As the response of the immune system depends on genotype, this study assessed the interaction effects of cytokine genes and season of birth (SOB) on schizotypy measured with the Schizotypal Personality Questionnaire (SPQ-74). We searched for associations of IL1B rs16944, IL4 rs2243250, and IL-1RN VNTR polymorphisms, SOB, and their interactions with the SPQ-74 total score in a sample of 278 healthy individuals. A significant effect of the IL4 X SOB interaction was found, p = 0.007 and η 2 = 0.028. We confirmed this effect using an extended sample of 373 individuals. Homozygotes CC born in winter showed the highest SPQ total score and differed significantly from winter-born T allele carriers, p = 0.049. This difference was demonstrated for cognitive-perceptual and disorganized but not interpersonal dimensions. The findings are consistent with the hypothesis that the cytokine genes by SOB interaction can influence variability of schizotypal traits in the general population. The IL4 T allele appeared to have a protective effect against the development of positive and disorganized schizotypal traits in winter-born individuals.

  13. Classical electromagnetic non-minimal coupling for spin 3/2 fields

    International Nuclear Information System (INIS)

    Villanueva, V. M.; Obregon, O.; Nieto, J. A.

    1996-01-01

    We obtain a non-minimal electromagnetic coupling for spin 3/2 particles from linearized N=2 Supergravity. This coupling coincides with the one found by Ferrara et al. by demanding g=2 at the tree level. Linearized Einstein field equations plus interaction terms are obtained by squaring the Rarita-Schwinger with this non-minimal coupling by using generalized Poisson brackets

  14. A general transformation to canonical form for potentials in pairwise interatomic interactions.

    Science.gov (United States)

    Walton, Jay R; Rivera-Rivera, Luis A; Lucchese, Robert R; Bevan, John W

    2015-06-14

    A generalized formulation of explicit force-based transformations is introduced to investigate the concept of a canonical potential in both fundamental chemical and intermolecular bonding. Different classes of representative ground electronic state pairwise interatomic interactions are referenced to a chosen canonical potential illustrating application of such transformations. Specifically, accurately determined potentials of the diatomic molecules H2, H2(+), HF, LiH, argon dimer, and one-dimensional dissociative coordinates in Ar-HBr, OC-HF, and OC-Cl2 are investigated throughout their bound potentials. Advantages of the current formulation for accurately evaluating equilibrium dissociation energies and a fundamentally different unified perspective on nature of intermolecular interactions will be emphasized. In particular, this canonical approach has significance to previous assertions that there is no very fundamental distinction between van der Waals bonding and covalent bonding or for that matter hydrogen and halogen bonds.

  15. Description of a general method to compute the fluid-structure interaction

    International Nuclear Information System (INIS)

    Jeanpierre, F.; Gibert, R.J.; Hoffmann, A.; Livolant, M.

    1979-01-01

    The vibrational characteristics of a structure in air may be considerably modified when the structure is immersed in a dense fluid. Such fluid structure interaction effects are important for the seismic or flow induced vibrational studies of various nuclear equipments, as for example the PWR internals, the fast reactor vessels, heat exchangers and fuel elements. In some simple situations, the fluid effects can be simulate by added masses, but in general, they are much more complicated. A general formulation to calculate precisely the vibrational behaviour of structures containing dense fluids is presented in this paper. That formulation can be easily introduced in finite elements computer codes, the fluid being described by special fluid elements. Its use is in principle limited to the linear range: small movements of structures, small pressure fluctuations. (orig.)

  16. Broken-pair, generalized seniority and interacting boson approximations in a spectroscopic study of Sn nuclei

    International Nuclear Information System (INIS)

    Bonsignori, K.; Allaart, K.; Egmond, A. van

    1983-01-01

    A broken-pair study of Sn nuclei is reported in which the model space includes two broken pair states. It is shown that for even Sn nuclei, with a rather simple Gaussian interaction and with single-particle-energies derived from data on odd nuclei, the main features of the excitation spectra up to about 3.5 MeV may be reproduced in this way. The idea of the generalized seniority scheme, that the composition of S-pair operator and that of the D-pair operator may be independent of the total number of pairs, is confirmed by the pair structures which result from energy minimization and diagonalization for each number of pairs separately. A general procedure is described to derive IBA parameters when the valence orbits are nondegenerate. Numerical results for Sn nuclei are given. (U.K.)

  17. A report on workshops: General circulation model study of climate- chemistry interaction

    International Nuclear Information System (INIS)

    Wei-Chyung, Wang; Isaksen, I.S.A.

    1993-01-01

    This report summarizes the discussion on General Circulation Model Study of Climate-Chemistry Interaction from two workshops, the first held 19--21 August 1992 at Oslo, Norway and the second 26--27 May 1993 at Albany, New York, USA. The workshops are the IAMAP activities under the Trace Constituent Working Group. The main objective of the two workshops was to recommend specific general circulation model (GCM) studies of the ozone distribution and the climatic effect of its changes. The workshops also discussed the climatic implications of increasing sulfate aerosols because of its importance to regional climate. The workshops were organized into four working groups: observation of atmospheric O 3 ; modeling of atmospheric chemical composition; modeling of sulfate aerosols; and aspects of climate modeling

  18. Electromagnetic processes in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Bertulani, C.A.; Rio de Janeiro Univ.

    1987-05-01

    A study of the processes generated by the electromagnetic interaction in relativistic nuclear, and atomic collisions is presented. Very strong electromagnetic fields for a very short time are present in distant collisions with no nuclear contact. Such fields can also lead to interesting effects, which are discussed here. (orig.)

  19. An Efficient Test for Gene-Environment Interaction in Generalized Linear Mixed Models with Family Data.

    Science.gov (United States)

    Mazo Lopera, Mauricio A; Coombes, Brandon J; de Andrade, Mariza

    2017-09-27

    Gene-environment (GE) interaction has important implications in the etiology of complex diseases that are caused by a combination of genetic factors and environment variables. Several authors have developed GE analysis in the context of independent subjects or longitudinal data using a gene-set. In this paper, we propose to analyze GE interaction for discrete and continuous phenotypes in family studies by incorporating the relatedness among the relatives for each family into a generalized linear mixed model (GLMM) and by using a gene-based variance component test. In addition, we deal with collinearity problems arising from linkage disequilibrium among single nucleotide polymorphisms (SNPs) by considering their coefficients as random effects under the null model estimation. We show that the best linear unbiased predictor (BLUP) of such random effects in the GLMM is equivalent to the ridge regression estimator. This equivalence provides a simple method to estimate the ridge penalty parameter in comparison to other computationally-demanding estimation approaches based on cross-validation schemes. We evaluated the proposed test using simulation studies and applied it to real data from the Baependi Heart Study consisting of 76 families. Using our approach, we identified an interaction between BMI and the Peroxisome Proliferator Activated Receptor Gamma ( PPARG ) gene associated with diabetes.

  20. Impact of cloud microphysics on cloud-radiation interactions in the CSU general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, L.D.; Randall, D.A.

    1995-04-01

    Our ability to study and quantify the impact of cloud-radiation interactions in studying global scale climate variations strongly relies upon the ability of general circulation models (GCMs) to simulate the coupling between the spatial and temporal variations of the model-generated cloudiness and atmospheric moisture budget components. In particular, the ability of GCMs to reproduce the geographical distribution of the sources and sinks of the planetary radiation balance depends upon their representation of the formation and dissipation of cloudiness in conjunction with cloud microphysics processes, and the fractional amount and optical characteristics of cloudiness in conjunction with the mass of condensate stored in the atmosphere. A cloud microphysics package which encompasses five prognostic variables for the mass of water vapor, cloud water, cloud ice, rain, and snow has been implemented in the Colorado State University General Circulation Model (CSU GCM) to simulate large-scale condensation processes. Convection interacts with the large-scale environment through the detrainment of cloud water and cloud ice at the top of cumulus towers. The cloud infrared emissivity and cloud optical depth of the model-generated cloudiness are interactive and depend upon the mass of cloud water and cloud ice suspended in the atmosphere. The global atmospheric moisture budget and planetary radiation budget of the CSU GCM obtained from a perpetual January simulation are discussed. Geographical distributions of the atmospheric moisture species are presented. Global maps of the top-of-atmosphere outgoing longwave radiation and planetary albedo are compared against Earth Radiation Budget Experiment (ERBE) satellite data.

  1. Maternal cognitions and mother-infant interaction in postnatal depression and generalized anxiety disorder.

    Science.gov (United States)

    Stein, Alan; Craske, Michelle G; Lehtonen, Annukka; Harvey, Allison; Savage-McGlynn, Emily; Davies, Beverley; Goodwin, Julia; Murray, Lynne; Cortina-Borja, Mario; Counsell, Nicholas

    2012-11-01

    Postnatal depression and anxiety have been shown to increase the risk of disturbances in mother-child interaction and child development. Research into mechanisms has focused on genetics and maternal behavior; maternal cognitions have received little attention. Our aim was to experimentally determine if worry and rumination in mothers with generalized anxiety disorder (GAD) and major depressive disorder (MDD), diagnosed in the postnatal 6 months, interfered with maternal responsiveness to their 10-month old infants. Mothers (N = 253: GAD n = 90; MDD n = 57; control n = 106) and their infants were randomized to either a worry/rumination prime (WRP) or a neutral prime (NP); mother-infant interactions were assessed before and after priming. Type of priming was a significant predictor of maternal cognitions, with WRP resulting in more negative thoughts, higher thought recurrence and more self-focus relative to NP across the entire sample. Interaction effects between group and priming were significant for two parenting variables: Compared with controls, WRP had a more negative impact on maternal responsiveness to infant vocalization for GAD, and to a lesser extent for MDD; WRP led to decreased maternal vocalization for GAD. Also, mothers with GAD used stronger control after the NP than WRP, as well as compared with other groups, and overall post-priming, their children exhibited lower emotional tone and more withdrawal. Across the entire sample, WRP was associated with increased child vocalization relative to NP. This study demonstrated that disturbances in maternal cognitions, in the context of postnatal anxiety and to a lesser degree depression, play a significant role in mother-child interaction. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

  2. Maternal Cognitions and Mother–Infant Interaction in Postnatal Depression and Generalized Anxiety Disorder

    Science.gov (United States)

    Stein, Alan; Craske, Michelle G.; Lehtonen, Annukka; Harvey, Allison; Savage-McGlynn, Emily; Davies, Beverley; Goodwin, Julia; Murray, Lynne; Cortina-Borja, Mario; Counsell, Nicholas

    2012-01-01

    Postnatal depression and anxiety have been shown to increase the risk of disturbances in mother–child interaction and child development. Research into mechanisms has focused on genetics and maternal behavior; maternal cognitions have received little attention. Our aim was to experimentally determine if worry and rumination in mothers with generalized anxiety disorder (GAD) and major depressive disorder (MDD), diagnosed in the postnatal 6 months, interfered with maternal responsiveness to their 10-month old infants. Mothers (N = 253: GAD n = 90; MDD n = 57; control n = 106) and their infants were randomized to either a worry/rumination prime (WRP) or a neutral prime (NP); mother–infant interactions were assessed before and after priming. Type of priming was a significant predictor of maternal cognitions, with WRP resulting in more negative thoughts, higher thought recurrence and more self-focus relative to NP across the entire sample. Interaction effects between group and priming were significant for two parenting variables: Compared with controls, WRP had a more negative impact on maternal responsiveness to infant vocalization for GAD, and to a lesser extent for MDD; WRP led to decreased maternal vocalization for GAD. Also, mothers with GAD used stronger control after the NP than WRP, as well as compared with other groups, and overall post-priming, their children exhibited lower emotional tone and more withdrawal. Across the entire sample, WRP was associated with increased child vocalization relative to NP. This study demonstrated that disturbances in maternal cognitions, in the context of postnatal anxiety and to a lesser degree depression, play a significant role in mother–child interaction. PMID:22288906

  3. Generalized atomic processes for interaction of intense femtosecond XUV- and X-ray radiation with solids

    International Nuclear Information System (INIS)

    Deschaud, B.; Peyrusse, O.; Rosmej, F.B.

    2014-01-01

    Generalized atomic processes are proposed to establish a consistent description from the free-atom approach to the heated and even up to the cold solid. It is based on a rigorous introduction of the Fermi-Dirac statistics, Pauli blocking factors and on the respect of the principle of detailed balance via the introduction of direct and inverse processes. A probability formalism driven by the degeneracy of the free electrons enables to establish a link of atomic rates valid from the heated atom up to the cold solid. This allows to describe photoionization processes in atomic population kinetics and subsequent solid matter heating on a femtosecond time scale. The Auger effect is linked to the 3-body recombination via a generalized 3-body recombination that is identified as a key mechanism, along with the collisional ionization, that follows energy deposition by photoionization of inner shells when short, intense and high-energy radiation interacts with matter. Detailed simulations are carried out for aluminum that highlight the importance of the generalized approach. (authors)

  4. General trust impedes perception of self-reported primary psychopathy in thin slices of social interaction.

    Science.gov (United States)

    Manson, Joseph H; Gervais, Matthew M; Bryant, Gregory A

    2018-01-01

    Little is known about people's ability to detect subclinical psychopathy from others' quotidian social behavior, or about the correlates of variation in this ability. This study sought to address these questions using a thin slice personality judgment paradigm. We presented 108 undergraduate judges (70.4% female) with 1.5 minute video thin slices of zero-acquaintance triadic conversations among other undergraduates (targets: n = 105, 57.1% female). Judges completed self-report measures of general trust, caution, and empathy. Target individuals had completed the Levenson Self-Report Psychopathy (LSRP) scale. Judges viewed the videos in one of three conditions: complete audio, silent, or audio from which semantic content had been removed using low-pass filtering. Using a novel other-rating version of the LSRP, judges' ratings of targets' primary psychopathy levels were significantly positively associated with targets' self-reports, but only in the complete audio condition. Judge general trust and target LSRP interacted, such that judges higher in general trust made less accurate judgments with respect to targets higher in primary and total psychopathy. Results are consistent with a scenario in which psychopathic traits are maintained in human populations by negative frequency dependent selection operating through the costs of detecting psychopathy in others.

  5. General trust impedes perception of self-reported primary psychopathy in thin slices of social interaction.

    Directory of Open Access Journals (Sweden)

    Joseph H Manson

    Full Text Available Little is known about people's ability to detect subclinical psychopathy from others' quotidian social behavior, or about the correlates of variation in this ability. This study sought to address these questions using a thin slice personality judgment paradigm. We presented 108 undergraduate judges (70.4% female with 1.5 minute video thin slices of zero-acquaintance triadic conversations among other undergraduates (targets: n = 105, 57.1% female. Judges completed self-report measures of general trust, caution, and empathy. Target individuals had completed the Levenson Self-Report Psychopathy (LSRP scale. Judges viewed the videos in one of three conditions: complete audio, silent, or audio from which semantic content had been removed using low-pass filtering. Using a novel other-rating version of the LSRP, judges' ratings of targets' primary psychopathy levels were significantly positively associated with targets' self-reports, but only in the complete audio condition. Judge general trust and target LSRP interacted, such that judges higher in general trust made less accurate judgments with respect to targets higher in primary and total psychopathy. Results are consistent with a scenario in which psychopathic traits are maintained in human populations by negative frequency dependent selection operating through the costs of detecting psychopathy in others.

  6. Particle acceleration by electromagnetic pulses

    International Nuclear Information System (INIS)

    Lai, H.M.

    1982-01-01

    Particle interaction with plane electromagnetic pulses is studied. It is shown that particle acceleration by a wavy pulse, depending on the shape of the pulse, may not be small. Further, a diffusive-type particle acceleration by multiple weak pulses is described and discussed. (author)

  7. Gauge invariant fractional electromagnetic fields

    International Nuclear Information System (INIS)

    Lazo, Matheus Jatkoske

    2011-01-01

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  8. Gauge invariant fractional electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lazo, Matheus Jatkoske, E-mail: matheuslazo@furg.br [Instituto de Matematica, Estatistica e Fisica - FURG, Rio Grande, RS (Brazil)

    2011-09-26

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  9. Electromagnetically shielded building

    International Nuclear Information System (INIS)

    Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.

    1992-01-01

    This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs

  10. Electromagnetically shielded building

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, T; Nakamura, M; Yabana, Y; Ishikawa, T; Nagata, K

    1992-04-21

    This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs.

  11. Fast vibrational configuration interaction using generalized curvilinear coordinates and self-consistent basis.

    Science.gov (United States)

    Scribano, Yohann; Lauvergnat, David M; Benoit, David M

    2010-09-07

    In this paper, we couple a numerical kinetic-energy operator approach to the direct-vibrational self-consistent field (VSCF)/vibrational configuration interaction (VCI) method for the calculation of vibrational anharmonic frequencies. By combining this with fast-VSCF, an efficient direct evaluation of the ab initio potential-energy surface (PES), we introduce a general formalism for the computation of vibrational bound states of molecular systems exhibiting large-amplitude motion such as methyl-group torsion. We validate our approach on an analytical two-dimensional model and apply it to the methanol molecule. We show that curvilinear coordinates lead to a significant improvement in the VSCF/VCI description of the torsional frequency in methanol, even for a simple two-mode coupling expansion of the PES. Moreover, we demonstrate that a curvilinear formulation of the fast-VSCF/VCI scheme improves its speed by a factor of two and its accuracy by a factor of 3.

  12. CSR Interaction for a 2D Energy-Chirped Bunch on a General Orbit

    International Nuclear Information System (INIS)

    Li, Rui

    2009-01-01

    When an electron bunch with initial linear energy chirp traverses a bunch compression chicane, the bunch interacts with itself via coherent synchrotron radiation (CSR) and space charge force. The effective longitudinal CSR force for such kind of 2D bunch on a circular orbit has been analyzed earlier (1). In this paper, we present the analytical results of the effective longitudinal CSR force for a 2D energy-chirped bunch going through a general orbit, which includes the entrance and exit of a circular orbit. In particular, we will show the behavior of the force in the last bend of a chicane when the bunch is under extreme compression. This is the condition when bifurcation of bunch phase space occurs in many CSR measurements. (1) R. Li, Phys. Rev. ST Accel. Beams 11, 024401 (2008)

  13. Electromagnetic launchers

    Science.gov (United States)

    Kolm, H.; Mongeau, P.; Williams, F.

    1980-09-01

    Recent advances in energy storage, switching and magnet technology make electromagnetic acceleration a viable alternative to chemical propulsion for certain tasks, and a means to perform other tasks not previously feasible. Applications include the acceleration of gram-size particles for hypervelocity research and the initiation of fusion by impact, a replacement for chemically propelled artillery, the transportation of cargo and personnel over inaccessible terrain, and the launching of space vehicles to supply massive space operations, and for the disposal of nuclear waste. The simplest launcher of interest is the railgun, in which a short-circuit slide or an arc is driven along two rails by direct current. The most sophisticated studied thus far is the mass driver, in which a superconducting shuttle bucket is accelerated by a line of pulse coils energized by capacitors at energy conversion efficiencies better than 90%. Other accelerators of interest include helical, brush-commutated motors, discrete coil arc commutated drivers, flux compression momentum transformers, and various hybrid electrochemical devices.

  14. Large-Scale Description of Interacting One-Dimensional Bose Gases: Generalized Hydrodynamics Supersedes Conventional Hydrodynamics

    Science.gov (United States)

    Doyon, Benjamin; Dubail, Jérôme; Konik, Robert; Yoshimura, Takato

    2017-11-01

    The theory of generalized hydrodynamics (GHD) was recently developed as a new tool for the study of inhomogeneous time evolution in many-body interacting systems with infinitely many conserved charges. In this Letter, we show that it supersedes the widely used conventional hydrodynamics (CHD) of one-dimensional Bose gases. We illustrate this by studying "nonlinear sound waves" emanating from initial density accumulations in the Lieb-Liniger model. We show that, at zero temperature and in the absence of shocks, GHD reduces to CHD, thus for the first time justifying its use from purely hydrodynamic principles. We show that sharp profiles, which appear in finite times in CHD, immediately dissolve into a higher hierarchy of reductions of GHD, with no sustained shock. CHD thereon fails to capture the correct hydrodynamics. We establish the correct hydrodynamic equations, which are finite-dimensional reductions of GHD characterized by multiple, disjoint Fermi seas. We further verify that at nonzero temperature, CHD fails at all nonzero times. Finally, we numerically confirm the emergence of hydrodynamics at zero temperature by comparing its predictions with a full quantum simulation performed using the NRG-TSA-abacus algorithm. The analysis is performed in the full interaction range, and is not restricted to either weak- or strong-repulsion regimes.

  15. Generalized spin-dependent WIMP-nucleus interactions and the DAMA modulation effect

    Energy Technology Data Exchange (ETDEWEB)

    Scopel, Stefano; Yoon, Kook-Hyun; Yoon, Jong-Hyun, E-mail: scopel@sogang.ac.kr, E-mail: koreasds@naver.com, E-mail: pledge200@gmail.com [Department of Physics, Sogang University, Seoul (Korea, Republic of)

    2015-07-01

    Guided by non-relativistic Effective Field Theory (EFT) we classify the most general spin-dependent interactions between a fermionic Weakly Interacting Massive Particle (WIMP) and nuclei, and within this class of models we discuss the viability of an interpretation of the DAMA modulation result in terms of a signal from WIMP elastic scatterings using a halo-independent approach. We find that, although several relativistic EFT's can lead to a spin-dependent cross section, in some cases with an explicit, non-negligible dependence on the WIMP incoming velocity, three main scenarios can be singled out in the non-relativistic limit which approximately encompass them all, and that only differ by their dependence on the transferred momentum. For two of them compatibility between DAMA and other constraints is possible for a WIMP mass below 30 GeV, but only for a WIMP velocity distribution in the halo of our Galaxy which departs from a Maxwellian. This is achieved by combining a suppression of the WIMP effective coupling to neutrons (to evade constraints from xenon and germanium detectors) to an explicit quadratic or quartic dependence of the cross section on the transferred momentum (that leads to a relative enhancement of the expected rate off sodium in DAMA compared to that off fluorine in droplet detectors and bubble chambers). For larger WIMP masses the same scenarios are excluded by scatterings off iodine in COUPP.

  16. Mathematical methods of electromagnetic theory

    CERN Document Server

    Friedrichs, Kurt O

    2014-01-01

    This text provides a mathematically precise but intuitive introduction to classical electromagnetic theory and wave propagation, with a brief introduction to special relativity. While written in a distinctive, modern style, Friedrichs manages to convey the physical intuition and 19th century basis of the equations, with an emphasis on conservation laws. Particularly striking features of the book include: (a) a mathematically rigorous derivation of the interaction of electromagnetic waves with matter, (b) a straightforward explanation of how to use variational principles to solve problems in el

  17. Energy, economy and equity interactions in a CGE [Computable General Equilibrium] model for Pakistan

    International Nuclear Information System (INIS)

    Naqvi, Farzana

    1997-01-01

    In the last three decades, Computable General Equilibrium modelling has emerged as an established field of applied economics. This book presents a CGE model developed for Pakistan with the hope that it will lay down a foundation for application of general equilibrium modelling for policy formation in Pakistan. As the country is being driven swiftly to become an open market economy, it becomes vital to found out the policy measures that can foster the objectives of economic planning, such as social equity, with the minimum loss of the efficiency gains from the open market resource allocations. It is not possible to build a model for practical use that can do justice to all sectors of the economy in modelling of their peculiar features. The CGE model developed in this book focuses on the energy sector. Energy is considered as one of the basic needs and an essential input to economic growth. Hence, energy policy has multiple criteria to meet. In this book, a case study has been carried out to analyse energy pricing policy in Pakistan using this CGE model of energy, economy and equity interactions. Hence, the book also demonstrates how researchers can model the fine details of one sector given the core structure of a CGE model. (UK)

  18. Influence of distributed delays on the dynamics of a generalized immune system cancerous cells interactions model

    Science.gov (United States)

    Piotrowska, M. J.; Bodnar, M.

    2018-01-01

    We present a generalisation of the mathematical models describing the interactions between the immune system and tumour cells which takes into account distributed time delays. For the analytical study we do not assume any particular form of the stimulus function describing the immune system reaction to presence of tumour cells but we only postulate its general properties. We analyse basic mathematical properties of the considered model such as existence and uniqueness of the solutions. Next, we discuss the existence of the stationary solutions and analytically investigate their stability depending on the forms of considered probability densities that is: Erlang, triangular and uniform probability densities separated or not from zero. Particular instability results are obtained for a general type of probability densities. Our results are compared with those for the model with discrete delays know from the literature. In addition, for each considered type of probability density, the model is fitted to the experimental data for the mice B-cell lymphoma showing mean square errors at the same comparable level. For estimated sets of parameters we discuss possibility of stabilisation of the tumour dormant steady state. Instability of this steady state results in uncontrolled tumour growth. In order to perform numerical simulation, following the idea of linear chain trick, we derive numerical procedures that allow us to solve systems with considered probability densities using standard algorithm for ordinary differential equations or differential equations with discrete delays.

  19. Recent studies of the electromagnetic mass of mesons

    International Nuclear Information System (INIS)

    Yan Mulin; Gao Daoneng

    1999-01-01

    Recent progress in studies of the electromagnetic mass of mesons, specially a new systematic method for calculating the electromagnetic self-energies, is reviewed. Some interesting results have been obtained, for example the mass ratios of the light quarks, the generalization of Dashen's theorem to the axial-vector sector, and the electromagnetic mass anomaly of massive Yang-Mills particles

  20. Biological effects of electromagnetic fields

    International Nuclear Information System (INIS)

    David, E.

    1993-01-01

    In this generally intelligible article, the author describes at first the physical fundamentals of electromagnetic fields and their basic biological significance and effects for animals and human beings before dealing with the discussion regarding limiting values and dangers. The article treats possible connections with leukaemia as well as ith melatonine production more detailed. (vhe) [de

  1. On Electromagnetic Modulation of Flow Instabilities, Mixing and Heat Transfer in Conducting and Magnetized Fluids

    Science.gov (United States)

    Kenjeres, S.

    2016-09-01

    In the present paper we give a concise review of some recent highlights of our research dealing with electromagnetic control of flow, mixing and heat transfer of electrically conductive or magnetized fluids. We apply a combination of state-of-art numerical (DNS and LES) and experimental (PIV and LIF) techniques to provide fundamental insights into the complex phenomena of interactions between imposed (or induced) electromagnetic fields and underlying fluid flow. Our analysis covers an extensive range of working fluids, i.e. weakly- and highly-electrically-conductive, as well as magnetized fluids. These interactions are defined through the presence of different types of body forces acting per volume of fluid. A fully closed system of governing equations containing an extended set of the Navier-Stokes and a simplified set of the Maxwell equations is presented. The four characteristic examples are selected: the electromagnetic control of self-sustained jet oscillations, the electromagnetic enhancement of heat transfer in thermal convection, the wake interactions behind magnetic obstacles and finally, the thermo-magnetic convection in differentially heated cubical enclosure. The comparative assessment between experimental and numerical results is presented. It is concluded that generally good agreement between simulations and experiments is obtained for all cases considered, proving the concept of electromagnetic modulation, which can be used in numerous technological applications.

  2. Circuit modeling for electromagnetic compatibility

    CERN Document Server

    Darney, Ian B

    2013-01-01

    Very simply, electromagnetic interference (EMI) costs money, reduces profits, and generally wreaks havoc for circuit designers in all industries. This book shows how the analytic tools of circuit theory can be used to simulate the coupling of interference into, and out of, any signal link in the system being reviewed. The technique is simple, systematic and accurate. It enables the design of any equipment to be tailored to meet EMC requirements. Every electronic system consists of a number of functional modules interconnected by signal links and power supply lines. Electromagnetic interference

  3. Gauge invariant fractional electromagnetic fields

    Science.gov (United States)

    Lazo, Matheus Jatkoske

    2011-09-01

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators.

  4. Oscillating electromagnetic soliton in an anisotropic ferromagnetic medium

    Energy Technology Data Exchange (ETDEWEB)

    Sathishkumar, P., E-mail: perumal_sathish@yahoo.co.in [Department of Physics, K.S.R. College of Engineering (Autonomous), Tiruchengode 637215, Tamilnadu (India); Senjudarvannan, R. [Department of Physics, Jansons Institute of Technology, Karumathampatty, Coimbatore 641659 (India)

    2017-05-01

    We investigate theoretically the propagation of electromagnetic oscillating soliton in the form of breather in an anisotropic ferromagnetic medium. The interaction of magnetization with the magnetic field component of the electromagnetic (EM) wave has been studied by solving Maxwell's equations coupled with a Landau–Lifshitz equation for the magnetization of the medium. We made a small perturbation on the magnetization and magnetic field along the direction of propagation of EM wave in the framework of reductive perturbation method and the associated nonlinear magnetization dynamics is governed by a generalized derivative nonlinear Schrödinger (DNLS) equation. In order to understand the dynamics of the concerned system, we employ the Jacobi elliptic function method to solve the DNLS equation and deduce breatherlike soliton modes for the EM wave in the medium. - Highlights: • The propagation of electromagnetic oscillating soliton in an anisotropic ferromagnetic medium is investigated in the presence of varying external magnetic field. • The magnetization and electromagnetic wave modulates in the form of breathing like oscillating solitons. • The governing nonlinear spin dynamical equation is studied through a reductive perturbation method. • The magnetization components of the ferromagnetic medium are derived using Jacobi elliptic functions method with the aid of symbolic computation.

  5. Nonlocal theory of electromagnetic wave decay into two electromagnetic waves in a rippled density plasma channel

    International Nuclear Information System (INIS)

    Sati, Priti; Tripathi, V. K.

    2012-01-01

    Parametric decay of a large amplitude electromagnetic wave into two electromagnetic modes in a rippled density plasma channel is investigated. The channel is taken to possess step density profile besides a density ripple of axial wave vector. The density ripple accounts for the momentum mismatch between the interacting waves and facilitates nonlinear coupling. For a given pump wave frequency, the requisite ripple wave number varies only a little w.r.t. the frequency of the low frequency decay wave. The radial localization of electromagnetic wave reduces the growth rate of the parametric instability. The growth rate decreases with the frequency of low frequency electromagnetic wave.

  6. Results of an interactively coupled atmospheric chemistry - general circulation model. Comparison with observations

    Energy Technology Data Exchange (ETDEWEB)

    Hein, R.; Dameris, M.; Schnadt, C. [and others

    2000-01-01

    An interactively coupled climate-chemistry model which enables a simultaneous treatment of meteorology and atmospheric chemistry and their feedbacks is presented. This is the first model, which interactively combines a general circulation model based on primitive equations with a rather complex model of stratospheric and tropospheric chemistry, and which is computational efficient enough to allow long-term integrations with currently available computer resources. The applied model version extends from the Earth's surface up to 10 hPa with a relatively high number (39) of vertical levels. We present the results of a present-day (1990) simulation and compare it to available observations. We focus on stratospheric dynamics and chemistry relevant to describe the stratospheric ozone layer. The current model version ECHAM4.L39(DLR)/CHEM can realistically reproduce stratospheric dynamics in the Arctic vortex region, including stratospheric warming events. This constitutes a major improvement compared to formerly applied model versions. However, apparent shortcomings in Antarctic circulation and temperatures persist. The seasonal and interannual variability of the ozone layer is simulated in accordance with observations. Activation and deactivation of chlorine in the polar stratospheric vortices and their interhemispheric differences are reproduced. The consideration of the chemistry feedback on dynamics results in an improved representation of the spatial distribution of stratospheric water vapor concentrations, i.e., the simulated meriodional water vapor gradient in the stratosphere is realistic. The present model version constitutes a powerful tool to investigate, for instance, the combined direct and indirect effects of anthropogenic trace gas emissions, and the future evolution of the ozone layer. (orig.)

  7. Non linear dynamic of Langmuir and electromagnetic waves in space plasmas

    International Nuclear Information System (INIS)

    Guede, Jose Ricardo Abalde

    1995-11-01

    The aim of this work is to study the nonlinear dynamics of Langmuir and electromagnetic waves in space plasmas. Firstly, the generalized Zakharov equations are derived which are used to study the hybrid parametric instability involving the generation of daughter Langmuir, electromagnetic and ion-acoustic waves induced by two counter-propagating Langmuir pump waves with different amplitudes based on a coupled dispersion relation. Secondly, starting from the generalized Zakharov equations the linear and nonlinear coupled mode theories of three-wave and four-wave parametric interactions are developed, respectively. In three-waves processes, a Langmuir wave decays into another Langmuir wave and an ion-acoustic wave (electrostatic parametric decay) or into an electromagnetic wave and an ion-acoustic wave (electromagnetic parametric decay). In four-wave (modulational) processes, the interaction involves two wave triplets: in the decay triplet a pump wave couples with a low-frequency wave to generate a Stokes wave, and in the fusion triplets: in the decay triplet a pump wave couples with a low-frequency wave to generate a Stokes wave, and in the fusion triplet the coupling of a pump wave with a low-frequency wave generate an anti-Stokes wave. These modulational processes are convective and resonant processes wherein the low-frequency modes are Eigenmodes of plasma and are known as the stimulated modulational processes. Four such processes are investigated in this thesis: two with Langmuir pump waves (electrostatic and hybrid stimulated modulation processes) and the other two with electromagnetic pump waves (stimulated modulation Brillouin scattering and electromagnetic stimulated modulation process). Applications of the theoretical results in space plasmas are discussed. In particular, it is shown that the electrostatic and electromagnetic parametric decay processes of Langmuir waves can model the generation and modulation of radio emissions and Langmuir waves in the

  8. High performance electromagnetic simulation tools

    Science.gov (United States)

    Gedney, Stephen D.; Whites, Keith W.

    1994-10-01

    Army Research Office Grant #DAAH04-93-G-0453 has supported the purchase of 24 additional compute nodes that were installed in the Intel iPsC/860 hypercube at the Univesity Of Kentucky (UK), rendering a 32-node multiprocessor. This facility has allowed the investigators to explore and extend the boundaries of electromagnetic simulation for important areas of defense concerns including microwave monolithic integrated circuit (MMIC) design/analysis and electromagnetic materials research and development. The iPSC/860 has also provided an ideal platform for MMIC circuit simulations. A number of parallel methods based on direct time-domain solutions of Maxwell's equations have been developed on the iPSC/860, including a parallel finite-difference time-domain (FDTD) algorithm, and a parallel planar generalized Yee-algorithm (PGY). The iPSC/860 has also provided an ideal platform on which to develop a 'virtual laboratory' to numerically analyze, scientifically study and develop new types of materials with beneficial electromagnetic properties. These materials simulations are capable of assembling hundreds of microscopic inclusions from which an electromagnetic full-wave solution will be obtained in toto. This powerful simulation tool has enabled research of the full-wave analysis of complex multicomponent MMIC devices and the electromagnetic properties of many types of materials to be performed numerically rather than strictly in the laboratory.

  9. Cloud-turbulence interactions: Sensitivity of a general circulation model to closure assumptions

    International Nuclear Information System (INIS)

    Brinkop, S.; Roeckner, E.

    1993-01-01

    Several approaches to parameterize the turbulent transport of momentum, heat, water vapour and cloud water for use in a general circulation model (GCM) have been tested in one-dimensional and three-dimensional model simulations. The schemes differ with respect to their closure assumptions (conventional eddy diffusivity model versus turbulent kinetic energy closure) and also regarding their treatment of cloud-turbulence interactions. The basis properties of these parameterizations are discussed first in column simulations of a stratocumulus-topped atmospheric boundary layer (ABL) under a strong subsidence inversion during the KONTROL experiment in the North Sea. It is found that the K-models tend to decouple the cloud layer from the adjacent layers because the turbulent activity is calculated from local variables. The higher-order scheme performs better in this respect because internally generated turbulence can be transported up and down through the action of turbulent diffusion. Thus, the TKE-scheme provides not only a better link between the cloud and the sub-cloud layer but also between the cloud and the inversion as a result of cloud-top entrainment. In the stratocumulus case study, where the cloud is confined by a pronounced subsidence inversion, increased entrainment favours cloud dilution through enhanced evaporation of cloud droplets. In the GCM study, however, additional cloud-top entrainment supports cloud formation because indirect cloud generating processes are promoted through efficient ventilation of the ABL, such as the enhanced moisture supply by surface evaporation and the increased depth of the ABL. As a result, tropical convection is more vigorous, the hydrological cycle is intensified, the whole troposphere becomes warmer and moister in general and the cloudiness in the upper part of the ABL is increased. (orig.)

  10. Results of an interactively coupled atmospheric chemistry – general circulation model: Comparison with observations

    Directory of Open Access Journals (Sweden)

    R. Hein

    Full Text Available The coupled climate-chemistry model ECHAM4.L39(DLR/CHEM is presented which enables a simultaneous treatment of meteorology and atmospheric chemistry and their feedbacks. This is the first model which interactively combines a general circulation model with a chemical model, employing most of the important reactions and species necessary to describe the stratospheric and upper tropospheric ozone chemistry, and which is computationally fast enough to allow long-term integrations with currently available computer resources. This is possible as the model time-step used for the chemistry can be chosen as large as the integration time-step for the dynamics. Vertically the atmosphere is discretized by 39 levels from the surface up to the top layer which is centred at 10 hPa, with a relatively high vertical resolution of approximately 700 m near the extra-tropical tropopause. We present the results of a control simulation representing recent conditions (1990 and compare it to available observations. The focus is on investigations of stratospheric dynamics and chemistry relevant to describe the stratospheric ozone layer. ECHAM4.L39(DLR/CHEM reproduces main features of stratospheric dynamics in the arctic vortex region, including stratospheric warming events. This constitutes a major improvement compared to earlier model versions. However, apparent shortcomings in Antarctic circulation and temperatures persist. The seasonal and interannual variability of the ozone layer is simulated in accordance with observations. Activation and deactivation of chlorine in the polar stratospheric vortices and their inter-hemispheric differences are reproduced. Considering methane oxidation as part of the dynamic-chemistry feedback results in an improved representation of the spatial distribution of stratospheric water vapour concentrations. The current model constitutes a powerful tool to investigate, for instance, the combined direct and indirect effects of anthropogenic

  11. General aspects of the nucleon-nucleon interaction and nuclear matter properties

    Energy Technology Data Exchange (ETDEWEB)

    Plohl, Oliver

    2008-07-25

    The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are

  12. General aspects of the nucleon-nucleon interaction and nuclear matter properties

    International Nuclear Information System (INIS)

    Plohl, Oliver

    2008-01-01

    The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are

  13. Electromagnetic scattering theory

    Science.gov (United States)

    Bird, J. F.; Farrell, R. A.

    1986-01-01

    Electromagnetic scattering theory is discussed with emphasis on the general stochastic variational principle (SVP) and its applications. The stochastic version of the Schwinger-type variational principle is presented, and explicit expressions for its integrals are considered. Results are summarized for scalar wave scattering from a classic rough-surface model and for vector wave scattering from a random dielectric-body model. Also considered are the selection of trial functions and the variational improvement of the Kirchhoff short-wave approximation appropriate to large size-parameters. Other applications of vector field theory discussed include a general vision theory and the analysis of hydromagnetism induced by ocean motion across the geomagnetic field. Levitational force-torque in the magnetic suspension of the disturbance compensation system (DISCOS), now deployed in NOVA satellites, is also analyzed using the developed theory.

  14. A physical model for low-frequency electromagnetic induction in the near field based on direct interaction between transmitter and receiver electrons.

    Science.gov (United States)

    Smith, Ray T; Jjunju, Fred P M; Young, Iain S; Taylor, Stephen; Maher, Simon

    2016-07-01

    A physical model of electromagnetic induction is developed which relates directly the forces between electrons in the transmitter and receiver windings of concentric coaxial finite coils in the near-field region. By applying the principle of superposition, the contributions from accelerating electrons in successive current loops are summed, allowing the peak-induced voltage in the receiver to be accurately predicted. Results show good agreement between theory and experiment for various receivers of different radii up to five times that of the transmitter. The limitations of the linear theory of electromagnetic induction are discussed in terms of the non-uniform current distribution caused by the skin effect. In particular, the explanation in terms of electromagnetic energy and Poynting's theorem is contrasted with a more direct explanation based on variable filament induction across the conductor cross section. As the direct physical model developed herein deals only with forces between discrete current elements, it can be readily adapted to suit different coil geometries and is widely applicable in various fields of research such as near-field communications, antenna design, wireless power transfer, sensor applications and beyond.

  15. General relativistic dynamics of an extreme mass-ratio binary interacting with an external body

    Science.gov (United States)

    Yang, Huan; Casals, Marc

    2017-10-01

    We study the dynamics of a hierarchical three-body system in the general relativistic regime: an extreme mass-ratio inner binary under the tidal influence of an external body. The inner binary consists of a central Schwarzschild black hole and a test body moving around it. We discuss three types of tidal effects on the orbit of the test body. First, the angular momentum of the inner binary precesses around the angular momentum of the outer binary. Second, the tidal field drives a "transient resonance" when the radial and azimuthal frequencies are commensurable. In contrast with resonances driven by the gravitational self-force, this tidal-driven resonance may boost the orbital angular momentum and eccentricity (a relativistic version of the Kozai-Lidov effect). Finally, for an orbit-dynamical effect during the nonresonant phase, we calculate the correction to the innermost stable circular (mean) orbit due to the tidal interaction. Hierarchical three-body systems are potential sources for future space-based gravitational wave missions, and the tidal effects that we find could contribute significantly to their waveform.

  16. Soil-structure interaction - a general method to calculate soil impedance

    International Nuclear Information System (INIS)

    Farvacque, M.; Gantenbein, F.

    1983-01-01

    A correct analysis of the seismic response of nuclear power plant buildings needs to take into account the soil structure interaction. The most classical and simple method consists in characterizing the soil by a stiffness and a damping function for each component of the translation and rotation of the foundation. In a more exact way an impedance function of the frequency may be introduced. Literature provides data to estimate these coefficients for simple soil and foundation configurations and using linear hypothesis. This paper presents a general method to calculate soil impedances which is based on the computation of the impulsive response of the soil using an axisymmetric 2D finite element Code (INCA). The Fourier transform of this response is made in the time interval before the return of the reflected waves on the boundaries of the F.E. domain. This procedure which limits the perturbing effects of the reflections is improved by introducing absorbing boundary elements. A parametric study for homogeneous and layered soils has been carried out using this method. (orig.)

  17. Accelerating progress in Artificial General Intelligence: Choosing a benchmark for natural world interaction

    Science.gov (United States)

    Rohrer, Brandon

    2010-12-01

    Measuring progress in the field of Artificial General Intelligence (AGI) can be difficult without commonly accepted methods of evaluation. An AGI benchmark would allow evaluation and comparison of the many computational intelligence algorithms that have been developed. In this paper I propose that a benchmark for natural world interaction would possess seven key characteristics: fitness, breadth, specificity, low cost, simplicity, range, and task focus. I also outline two benchmark examples that meet most of these criteria. In the first, the direction task, a human coach directs a machine to perform a novel task in an unfamiliar environment. The direction task is extremely broad, but may be idealistic. In the second, the AGI battery, AGI candidates are evaluated based on their performance on a collection of more specific tasks. The AGI battery is designed to be appropriate to the capabilities of currently existing systems. Both the direction task and the AGI battery would require further definition before implementing. The paper concludes with a description of a task that might be included in the AGI battery: the search and retrieve task.

  18. Geometrical Aspects of non-gravitational interactions

    OpenAIRE

    Roldan, Omar; Barros Jr, C. C.

    2016-01-01

    In this work we look for a geometric description of non-gravitational forces. The basic ideas are proposed studying the interaction between a punctual particle and an electromagnetic external field. For this purpose, we introduce the concept of proper space-time, that allow us to describe this interaction in a way analogous to the one that the general relativity theory does for gravitation. The field equations that define this geometry are similar to the Einstein's equations, where in general...

  19. Electromagnetic wave matching device

    International Nuclear Information System (INIS)

    Hirata, Yosuke; Mitsunaka, Yoshika; Hayashi, Ken-ichi; Ito, Yasuyuki.

    1997-01-01

    The present invention provides an electromagnetic wave matching capable of reducing a cost for the transmission system in a system of using electromagnetic waves for plasma heating of a thermonuclear reactor. Namely, incident electromagnetic waves are reflected by using a plurality of phase correction mirrors. The reflected electromagnetic waves are connected to an external transmission system through an exit. The phase correction mirrors have such a shape to receive a plurality of beam-like electromagnetic waves and output electromagnetic waves by the number different from the number of the received electromagnetic wave beams having a predetermined distribution. Further, at least two of the phase correction mirrors have such a shape to change the phase of the electromagnetic waves beams incident to the reflection surface of the phase correction mirrors by a predetermined amount corresponding to the position of the reflection surface. Then, the cost for transmission system can greatly be reduced. (I.S.)

  20. Breaking Newton’s third law: electromagnetic instances

    International Nuclear Information System (INIS)

    Kneubil, Fabiana B

    2016-01-01

    In this work, three instances are discussed within electromagnetism which highlight failures in the validity of Newton’s third law, all of them related to moving charged particles. It is well known that electromagnetic theory paved the way for relativity and that it disclosed new phenomena which were not compatible with the laws of mechanics. However, even if widely known in its generality, this issue is not clearly approached in introductory textbooks and it is difficult for students to perceive by themselves. Three explicit concrete situations involving the breaking of Newton’s third law are presented in this paper, together with a didactical procedure to construct graphically the configurations of electric field lines, which allow pictures produced by interactive radiation simulators available in websites to be better understood. (paper)

  1. Optimization and inverse problems in electromagnetism

    CERN Document Server

    Wiak, Sławomir

    2003-01-01

    From 12 to 14 September 2002, the Academy of Humanities and Economics (AHE) hosted the workshop "Optimization and Inverse Problems in Electromagnetism". After this bi-annual event, a large number of papers were assembled and combined in this book. During the workshop recent developments and applications in optimization and inverse methodologies for electromagnetic fields were discussed. The contributions selected for the present volume cover a wide spectrum of inverse and optimal electromagnetic methodologies, ranging from theoretical to practical applications. A number of new optimal and inverse methodologies were proposed. There are contributions related to dedicated software. Optimization and Inverse Problems in Electromagnetism consists of three thematic chapters, covering: -General papers (survey of specific aspects of optimization and inverse problems in electromagnetism), -Methodologies, -Industrial Applications. The book can be useful to students of electrical and electronics engineering, computer sci...

  2. CO2, energy and economy interactions: A multisectoral, dynamic, computable general equilibrium model for Korea

    Science.gov (United States)

    Kang, Yoonyoung

    While vast resources have been invested in the development of computational models for cost-benefit analysis for the "whole world" or for the largest economies (e.g. United States, Japan, Germany), the remainder have been thrown together into one model for the "rest of the world." This study presents a multi-sectoral, dynamic, computable general equilibrium (CGE) model for Korea. This research evaluates the impacts of controlling COsb2 emissions using a multisectoral CGE model. This CGE economy-energy-environment model analyzes and quantifies the interactions between COsb2, energy and economy. This study examines interactions and influences of key environmental policy components: applied economic instruments, emission targets, and environmental tax revenue recycling methods. The most cost-effective economic instrument is the carbon tax. The economic effects discussed include impacts on main macroeconomic variables (in particular, economic growth), sectoral production, and the energy market. This study considers several aspects of various COsb2 control policies, such as the basic variables in the economy: capital stock and net foreign debt. The results indicate emissions might be stabilized in Korea at the expense of economic growth and with dramatic sectoral allocation effects. Carbon dioxide emissions stabilization could be achieved to the tune of a 600 trillion won loss over a 20 year period (1990-2010). The average annual real GDP would decrease by 2.10% over the simulation period compared to the 5.87% increase in the Business-as-Usual. This model satisfies an immediate need for a policy simulation model for Korea and provides the basic framework for similar economies. It is critical to keep the central economic question at the forefront of any discussion regarding environmental protection. How much will reform cost, and what does the economy stand to gain and lose? Without this model, the policy makers might resort to hesitation or even blind speculation. With

  3. Chinese Elders' views on their interactions in general practice: a Grounded Theory study.

    Science.gov (United States)

    Liu, Zhenmi; Beaver, Kinta; Speed, Shaun

    2015-01-01

    The Chinese ethnic population are among the UK's largest visible minority but there is limited evidence about this population, their views about their interactions with General Practitioners (GPs) and how this impacts on their health. This study aimed to explore Chinese Elders' experiences of and attitudes towards the provision of health services in primary care. The method of investigation was a Grounded Theory study using open-ended in-depth interviews. Purposive and theoretical sampling was used to recruit thirty-three Chinese Elders from Chinese communities in the North West of England. Face-to-face interviews were conducted and audio-recorded; transcripts were translated, back translated, analysed and coded by all members of the research team to identify concepts following the Grounded Theory approach. Themes were generated from the data and were used to guide the study into the theoretical sampling phase of the investigation. Chinese Elders were inclined to present to GPs only when health concerns were perceived as serious. This was defined as being beyond their ability to self-manage. Elders tended to adopt self-management strategies rather than follow professional advice. This was mainly due to communication difficulties, poor understanding of the advice doctors gave, and the way that Chinese patients interpreted and used the advice they were given. Chinese Elders reported that the purpose of contacting doctors was to obtain medicines. They presumed that once medication had been prescribed their symptoms would be cured, and then they believed that they could self-manage their health, usually without further GP or other medical follow up. These data suggest that significant misunderstandings between Chinese Elders and GPs exist. The findings highlight the dissatisfaction expressed by Elders regarding their interactions with UK health professionals. Chinese Elders' perceptions are influenced by the way Chinese people think about health and illness, and also

  4. General correlation and partial correlation analysis in finding interactions: with Spearman rank correlation and proportion correlation as correlation measures

    OpenAIRE

    WenJun Zhang; Xin Li

    2015-01-01

    Between-taxon interactions can be detected by calculating the sampling data of taxon sample type. In present study, Spearman rank correlation and proportion correlation are chosen as the general correlation measures, and their partial correlations are calculated and compared. The results show that for Spearman rank correlation measure, in all predicted candidate direct interactions by partial correlation, about 16.77% (x, 0-45.4%) of them are not successfully detected by Spearman rank correla...

  5. Electromagnetic form factors of a massive neutrino

    International Nuclear Information System (INIS)

    Dvornikov, M.S.; Studenikin, A.I.

    2004-01-01

    Electromagnetic form factors of a massive neutrino are studied in a minimally extended standard model in an arbitrary R ξ gauge and taking into account the dependence on the masses of all interacting particles. The contribution from all Feynman diagrams to the electric, magnetic, and anapole form factors, in which the dependence of the masses of all particles as well as on gauge parameters is accounted for exactly, are obtained for the first time in explicit form. The asymptotic behavior of the magnetic form factor for large negative squares of the momentum of an external photon is analyzed and the expression for the anapole moment of a massive neutrino is derived. The results are generalized to the case of mixing between various flavors of the neutrino. Explicit expressions are obtained for the electric, magnetic, and electric dipole and anapole transitional form factors as well as for the transitional electric dipole moment

  6. Electromagnetic form factors

    International Nuclear Information System (INIS)

    Desplanques, B.

    1987-01-01

    Electromagnetic form factors, in first approximation, are sensitive to spatial distribution of nucleons and to their current. In second approximation, more precise effects are concerned, whose role is increasing with momentum transfer and participating essentially of short range nuclei description. They concern of course the nucleon-nucleon interaction while approaching each other and keeping their free-state identity, but also mutually polarizing one the other. In this last effect, radial and orbital excitations of nucleon, the nucleon mesonic cloud modification and the nucleon antinucleon pair excitation are included. In this paper, these contributions are discussed while trying to find the important elements for a good description of form factors. Current questions are also discussed. Light nuclei are essentially concerned [fr

  7. CONSEQUENCES OF SYMMETRY GROUPS FOR ELECTROMAGNETIC PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    MacFarlane, A. J.; Sudarshan, E. C.G.

    1963-06-15

    The electromagnetic properties of SU/sub 3/ supermultiplets are obtained formally by a unitary transformation of a theory whose SU/sub 3/ invariant strong interactions are perturbed by merely charge-independent interactions. Several new results are presented, but the emphasis is on the simplicity and power of the method. Electromagnetic properties of the first and second kinds are distinguished, the former being independent of the precise manner in which the particular electromagnetic property depends on the electric charge current density. It is shown that all except two relations between the magnetic moments of the baryon octet hold equally well for other electromagnetic properties like self energies and Compton scattering amplitudes. (auth)

  8. A general solution for the dynamics of a generalized non-degenerate optical parametric down-conversion interaction by virtue of the Lewis-Riesenfeld invariant theory

    International Nuclear Information System (INIS)

    Li Jiangfan; Jiang Zongfu; Xiao Fuliang; Huang Chunjia

    2005-01-01

    The dynamics of a generalized non-degenerate optical parametric down-conversion interaction whose Hamiltonian includes an arbitrary time-dependent driving part and a two-mode coupled part is studied by adopting the Lewis-Riesenfeld invariant theory. The closed formulae for the evolution of the quantum states and the evolution operators of the system are obtained. It is shown that various generalized squeezed states arise naturally in the process, and the two-mode squeezed effect is independent of the driving part. An explicitly analytical solution of the Schroedinger equation is further derived as the classical generalized force acting on each mode and the coupling of the two modes both have harmonic time dependences. This solution is found to be in agreement with previous research in special cases

  9. The eighth national electromagnetics meeting. Extended abstracts

    International Nuclear Information System (INIS)

    Eloranta, E.; Jokela, K.

    1998-01-01

    The National Electromagnetics Meeting has been arranged annually since 1991 in Finland. The purpose of the meeting is to convene the persons working with problems of electromagnetics and to enhance the interaction between different research groups in different disciplines. The eighth meeting was held at the Radiation and Nuclear Safety Authority (STUK) August 27, 1998. The meeting is also the national meeting of the URSI (L'Union Radio-Scientifique Internationals)(Commission B: Fields and Waves) and the IEEE MTT/AP/ED Finland Chapter (Institute of Electrical and Electronics Engineers, Inc.). The report includes the extended abstracts of the presentations given in the National Electromagnetics Meeting at STUK. (orig.)

  10. Genetic effects of nonionizing electromagnetic fields

    International Nuclear Information System (INIS)

    Lai, Henry

    2001-01-01

    Due to the increased use of electricity and wireless communication devices, there is a concern on whether exposure to nonionizing electromagnetic fields (50/60 Hz fields and radiofrequency radiation) can lead to harmful health effects, particularly, genetic effects and cancer development. This presentation will review recent research on genetic effects of power line frequency and radiofrequency electromagnetic fields. Even though the mechanism of interaction is still unknown, there is increasing evidence that these electromagnetic fields at low intensities can cause genetic damage in cells. There is also evidence suggesting that the effects are caused by oxidative stress. (author)

  11. The eighth national electromagnetics meeting. Extended abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Eloranta, E.; Jokela, K. [eds.

    1998-09-01

    The National Electromagnetics Meeting has been arranged annually since 1991 in Finland. The purpose of the meeting is to convene the persons working with problems of electromagnetics and to enhance the interaction between different research groups in different disciplines. The eighth meeting was held at the Radiation and Nuclear Safety Authority (STUK) August 27, 1998. The meeting is also the national meeting of the URSI (L`Union Radio-Scientifique Internationals)(Commission B: Fields and Waves) and the IEEE MTT/AP/ED Finland Chapter (Institute of Electrical and Electronics Engineers, Inc.). The report includes the extended abstracts of the presentations given in the National Electromagnetics Meeting at STUK. (orig.)

  12. Mathematics and electromagnetism; Matematicas y electromagnetismo

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Danta, M.

    2000-07-01

    Symbiosis between mathematics and electromagnetism is analyzed in a simple and concise manner by taking a historical perspective. The universal tool character of mathematical models allowed the transfer of models from several branches of physics into the realm of electromagnetism by drawing analogies. The mutual interdependence between covariant formulation and tensor calculus is marked. The paper focuses on the guiding idea of field theory and Maxwell's equations. Likewise, geometrization of interactions in connection with gauge fields is also noted. (Author)

  13. Monte-Carlo simulation of electromagnetic showers

    International Nuclear Information System (INIS)

    Amatuni, Ts.A.

    1984-01-01

    The universal ELSS-1 program for Monte Carlo simulation of high energy electromagnetic showers in homogeneous absorbers of arbitrary geometry is written. The major processes and effects of electron and photon interaction with matter, particularly the Landau-Pomeranchuk-Migdal effect, are taken into account in the simulation procedures. The simulation results are compared with experimental data. Some characteristics of shower detectors and electromagnetic showers for energies up 1 TeV are calculated

  14. Nucleon Electromagnetic Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi

    2007-10-01

    There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.

  15. Generalized Lorenz-Mie Theories

    CERN Document Server

    Gouesbet, Gérard

    2011-01-01

    The Lorenz-Mie theory, describing the interaction between a homogeneous sphere and an electromagnetic plane wave, is likely to be one of the most famous theories in light scattering. But, with the advent of lasers and their increasing development in various fields, it has become too old-fashioned to meet most of the modern requisites. The book deals with generalized Lorenz-Mie theories when the illuminating beam is an electromagnetic arbitrary shaped beam, relying on the method of separation of variables. A particular emphasis is stressed on the case of the homogeneous sphere but other regular particles are considered too. An extensive discussion of the methods available to the evaluation of beam shape coefficients describing the illuminating beam is provided, and several methods are discussed. Applications concern many fields such as optical particle sizing and, more generally, optical particle characterization, morphology-dependent resonances, or mechanical effects of light for optical trapping, optical twe...

  16. Electromagnetic Compatibility of Devices on Hybrid Electromagnetic Components

    Science.gov (United States)

    Konesev, S. G.; Khazieva, R. T.; Kirillov, R. V.; Gainutdinov, I. Z.; Kondratyev, E. Y.

    2018-01-01

    There is a general tendency to reduce the weight and dimensions, the consumption of conductive and electrical insulating materials, increase the reliability and energy efficiency of electrical devices. In recent years, designers have been actively developing devices based on hybrid electromagnetic components (HEMC) such as inductive-capacitive converters (ICC), voltages pulse generators (VPG), secondary power supplies (SPS), capacitive storage devices (CSD), induction heating systems (IHS). Sources of power supplies of similar electrical devices contain, as a rule, links of increased frequency and function in key (pulse) modes, which leads to an increase in electromagnetic interference (EMI). Nonlinear and periodic (impulse) loads, non-sinusoidal (pulsation) of the electromotive force and nonlinearity of the internal parameters of the source and input circuits of consumers distort the shape of the input voltage lead to an increase in thermal losses from the higher harmonic currents, aging of the insulation, increase in the weight of the power supply filter units, resonance at higher harmonics. The most important task is to analyze the operation of electrotechnical devices based on HEMC from the point of view of creating EMIs and assessing their electromagnetic compatibility (EMC) with power supply systems (PSS). The article presents the results of research on the operation of an IHS, the operation principle of a secondary power supply source of which is based on the operation of a half-bridge autonomous inverter, the switching circuit of which is made in the form of a HEMC, called the «multifunctional integrated electromagnetic component»" (MIEC).

  17. Eikonal Scattering in the sdg Interacting Boson Model:. Analytical Results in the SUsdg(3) Limit and Their Generalizations

    Science.gov (United States)

    Kota, V. K. B.

    General expression for the representation matrix elements in the SUsdg(3) limit of the sdg interacting boson model (sdgIBM) is derived that determine the scattering amplitude in the eikonal approximation for medium energy proton-nucleus scattering when the target nucleus is deformed and it is described by the SUsdg(3) limit. The SUsdg(3) result is generalized to two important situations: (i) when the target nucleus ground band states are described as states arising out of angular momentum projection from a general single Kπ = 0+ intrinsic state in sdg space; (ii) for rotational bands built on one-phonon excitations in sdgIBM.

  18. Use of a PhET Interactive Simulation in General Chemistry Laboratory: Models of the Hydrogen Atom

    Science.gov (United States)

    Clark, Ted M.; Chamberlain, Julia M.

    2014-01-01

    An activity supporting the PhET interactive simulation, Models of the Hydrogen Atom, has been designed and used in the laboratory portion of a general chemistry course. This article describes the framework used to successfully accomplish implementation on a large scale. The activity guides students through a comparison and analysis of the six…

  19. Large-scale parallel configuration interaction. I. Nonrelativisticand scalar-relativistic general active space implementationwith application to (Rb-Ba)+

    DEFF Research Database (Denmark)

    Knecht, Stefan; Jensen, Hans Jørgen Aagaard; Fleig, Timo

    2008-01-01

    We present a parallel implementation of a string-driven general active space configuration interaction program for nonrelativistic and scalar-relativistic electronic-structure calculations. The code has been modularly incorporated in the DIRAC quantum chemistry program package. The implementation...

  20. Mean energy of some interacting bosonic systems derived by virtue of the generalized Hellmann-Feynman theorem

    Science.gov (United States)

    Fan, Hong-yi; Xu, Xue-xiang

    2009-06-01

    By virtue of the generalized Hellmann-Feynman theorem [H. Y. Fan and B. Z. Chen, Phys. Lett. A 203, 95 (1995)], we derive the mean energy of some interacting bosonic systems for some Hamiltonian models without proceeding with diagonalizing the Hamiltonians. Our work extends the field of applications of the Hellmann-Feynman theorem and may enrich the theory of quantum statistics.

  1. Collective scattering of electromagnetic waves from a relativistic magnetized plasma

    International Nuclear Information System (INIS)

    Lu Quankang

    1998-01-01

    Recently, laser and microwave scattering has become one of the important diagnostic means for plasma. Laser and microwave correlative scattering spectrum is determined by particle-density fluctuations in a weak turbulent plasma. In a relativistic plasma, on the basis of complete electromagnetic-interaction between particles, a general expression for particle density fluctuations and spectrums of laser and microwave scattering from a magnetized plasma are derived. The laser and microwave scattering spectrums provide informations on electron density and temperature, ion temperature, resonance and nonresonance effects. (author)

  2. Scattering theory of stochastic electromagnetic light waves.

    Science.gov (United States)

    Wang, Tao; Zhao, Daomu

    2010-07-15

    We generalize scattering theory to stochastic electromagnetic light waves. It is shown that when a stochastic electromagnetic light wave is scattered from a medium, the properties of the scattered field can be characterized by a 3 x 3 cross-spectral density matrix. An example of scattering of a spatially coherent electromagnetic light wave from a deterministic medium is discussed. Some interesting phenomena emerge, including the changes of the spectral degree of coherence and of the spectral degree of polarization of the scattered field.

  3. Impact of wall potential on the fluid-wall interaction in a cylindrical capillary and a generalized Kelvin equation

    International Nuclear Information System (INIS)

    Jakubov, T.S.; Mainwaring, D.E.

    2006-01-01

    In the present work a generalized Kelvin equation for a fluid confined in thick-walled cylindrical capillary is developed. This has been accomplished by including the potential energy function for interaction between a solid wall of a capillary and a confined fluid into the Kelvin equation. Using the Lennard-Jones 12-6 potential, an explicit form of the potential energy functions as expressed by hypergeometrical functions have been derived-firstly, for the interaction between a solid wall and a test atom placed at an arbitrary point in a long open-end capillary, and thereafter for the body-body interaction between the solid wall and a confined Lennard-Jones fluid. Further, this generalized Kelvin equation has been applied to detailed description hysteresis phenomena in such capillaries. All numerical calculations have been carried out for the model argon-graphite system at 90 K

  4. Interactions of two co-propagating laser beams in underdense plasmas using a generalized Peaceman-Rachford ADI form

    International Nuclear Information System (INIS)

    Mahdy, A.I.

    2005-12-01

    A generalized Peaceman-Rachford (P-R) ADI form based on the regularized finite difference scheme is employed in order to study the interactions of two co-propagating laser beams in underdense plasmas. A numerical algorithm using the P-R ADI form is constructed for solution of coupled 2D time-dependent non-linear Schroedinger equations for quasineutral plasmas in paraxial approximation. The ability of the form to solve the equations is discussed, and its performance in simulating phenomena associated with the interactions in the presence of pondermotive nonlinearity and relativistic nonlinearity is examined. It is shown that the generalized P-R ADI form can accurately solve the coupled NLS equations. With simulation results, the form is shown to be suitable to simulate the interactions of two co-propagating laser beams with underdense plasma, and it can successively simulate the associated phenomena at varying conditions. (author)

  5. Quantum processes in an intense electromagnetic field

    International Nuclear Information System (INIS)

    Gitman, D.M.

    1976-01-01

    An approach is proposed to the consideration of processes in an external electromagnetic field which produces real pairs. Interaction with the field is taken into account precisely with the aid of solutions of the Dirac's equation. Processes of arbitrary order with respect to electron-photon interaction are considered

  6. Holographic Dark Energy Interacting with Two Fluids and Validity of Generalized Second Law of Thermodynamics

    OpenAIRE

    Debnath, Ujjal

    2010-01-01

    We have considered a cosmological model of holographic dark energy interacting with dark matter and another unknown component of dark energy of the universe. We have assumed two interaction terms $Q$ and $Q'$ in order to include the scenario in which the mutual interaction between the two principal components (i.e., holographic dark energy and dark matter) of the universe leads to some loss in other forms of cosmic constituents. Our model is valid for any sign of $Q$ and $Q'$. If $Q

  7. General, Interactive Computer Program for the Solution of the Schrodinger Equation

    Science.gov (United States)

    Griffin, Donald C.; McGhie, James B.

    1973-01-01

    Discusses an interactive computer algorithm which allows beginning students to solve one- and three-dimensional quantum problems. Included is an example of the Thomas-Fermi-Dirac central field approximation. (CC)

  8. Generalization through the Recurrent Interaction of Episodic Memories: A Model of the Hippocampal System

    Science.gov (United States)

    Kumaran, Dharshan; McClelland, James L.

    2012-01-01

    In this article, we present a perspective on the role of the hippocampal system in generalization, instantiated in a computational model called REMERGE (recurrency and episodic memory results in generalization). We expose a fundamental, but neglected, tension between prevailing computational theories that emphasize the function of the hippocampus…

  9. Electromagnetic properties of neutrinos

    International Nuclear Information System (INIS)

    Ould-Saada, F.

    1996-01-01

    Electromagnetic properties of neutrinos and their implications are discussed, and the experimental situation summarised. Spin precession in solar magnetic fields presents a solution of the solar neutrino problem. A magnetic moment, μ ν , of the order of 10 -11 μ B would be needed. In the simplest extension of the standard model, with no-vanishing neutrino masses, dipole moment interactions are allowed through higher order processes. A neutrino mass of ≅10 eV would give μ ν ≅10 -18 μ B , much smaller than the present experimental upper limit of 2x10 -10 μ B . Although model-dependent, upper bounds on dipole moments from astrophysics and cosmology are 10 to 100 times more stringent. Any values of μ ν , larger than the SM predictions, would then signal the onset of new physics. Among the processes sensitive to the magnetic moment, νe - scattering presents two advantages: it is a pure weak, theoretically well understood process, and the recoil electron can be easily measured. A hypothetical electromagnetic contribution to the cross-section would dominate at low energies. A low background detector, MUNU, being built at the Bugey nuclear reactor is presented.It is based on a gas TPC, surrounded by a scintillator. The threshold on the electron recoil energy can be set very low, around 500 keV, giving the experiment a good sensitivity to the magnetic moment of the ν e , extending down to 2x10 -11 μ B . (author) 15 figs., 5 tabs., 96 refs

  10. Electromagnetic properties of neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Ould-Saada, F [Zurich Univ. (Switzerland). Inst. fuer Physik

    1996-11-01

    Electromagnetic properties of neutrinos and their implications are discussed, and the experimental situation summarised. Spin precession in solar magnetic fields presents a solution of the solar neutrino problem. A magnetic moment, {mu}{sub {nu}}, of the order of 10{sup -11} {mu}{sub B} would be needed. In the simplest extension of the standard model, with no-vanishing neutrino masses, dipole moment interactions are allowed through higher order processes. A neutrino mass of {approx_equal}10 eV would give {mu}{sub {nu}}{approx_equal}10{sup -18} {mu}{sub B}, much smaller than the present experimental upper limit of 2x10{sup -10} {mu}{sub B}. Although model-dependent, upper bounds on dipole moments from astrophysics and cosmology are 10 to 100 times more stringent. Any values of {mu}{sub {nu}}, larger than the SM predictions, would then signal the onset of new physics. Among the processes sensitive to the magnetic moment, {nu}e{sup -} scattering presents two advantages: it is a pure weak, theoretically well understood process, and the recoil electron can be easily measured. A hypothetical electromagnetic contribution to the cross-section would dominate at low energies. A low background detector, MUNU, being built at the Bugey nuclear reactor is presented.It is based on a gas TPC, surrounded by a scintillator. The threshold on the electron recoil energy can be set very low, around 500 keV, giving the experiment a good sensitivity to the magnetic moment of the {nu}{sub e}, extending down to 2x10{sup -11} {mu}{sub B}. (author) 15 figs., 5 tabs., 96 refs.

  11. Electromagnetic signatures of far-field gravitational radiation in the 1 + 3 approach

    International Nuclear Information System (INIS)

    Chua, Alvin J K; Cañizares, Priscilla; Gair, Jonathan R

    2015-01-01

    Gravitational waves (GWs) from astrophysical sources can interact with background electromagnetic fields, giving rise to distinctive and potentially detectable electromagnetic signatures. In this paper, we study such interactions for far-field gravitational radiation using the 1 + 3 approach to relativity. Linearized equations for the electromagnetic field on perturbed Minkowski space are derived and solved analytically. The inverse Gertsenshteĭn conversion of GWs in a static electromagnetic field is rederived, and the resultant electromagnetic radiation is shown to be significant for highly magnetized pulsars in compact binary systems. We also obtain a variety of nonlinear interference effects for interacting gravitational and electromagnetic waves, although wave–wave resonances previously described in the literature are absent when the electric–magnetic self-interaction is taken into account. The fluctuation and amplification of electromagnetic energy flux as the GW strength increases towards the gravitational–electromagnetic frequency ratio is a possible signature of gravitational radiation from extended astrophysical sources. (paper)

  12. A general spectral method for the numerical simulation of one-dimensional interacting fermions

    Science.gov (United States)

    Clason, Christian; von Winckel, Gregory

    2012-08-01

    This software implements a general framework for the direct numerical simulation of systems of interacting fermions in one spatial dimension. The approach is based on a specially adapted nodal spectral Galerkin method, where the basis functions are constructed to obey the antisymmetry relations of fermionic wave functions. An efficient Matlab program for the assembly of the stiffness and potential matrices is presented, which exploits the combinatorial structure of the sparsity pattern arising from this discretization to achieve optimal run-time complexity. This program allows the accurate discretization of systems with multiple fermions subject to arbitrary potentials, e.g., for verifying the accuracy of multi-particle approximations such as Hartree-Fock in the few-particle limit. It can be used for eigenvalue computations or numerical solutions of the time-dependent Schrödinger equation. The new version includes a Python implementation of the presented approach. New version program summaryProgram title: assembleFermiMatrix Catalogue identifier: AEKO_v1_1 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKO_v1_1.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 332 No. of bytes in distributed program, including test data, etc.: 5418 Distribution format: tar.gz Programming language: MATLAB/GNU Octave, Python Computer: Any architecture supported by MATLAB, GNU Octave or Python Operating system: Any supported by MATLAB, GNU Octave or Python RAM: Depends on the data Classification: 4.3, 2.2. External routines: Python 2.7+, NumPy 1.3+, SciPy 0.10+ Catalogue identifier of previous version: AEKO_v1_0 Journal reference of previous version: Comput. Phys. Commun. 183 (2012) 405 Does the new version supersede the previous version?: Yes Nature of problem: The direct numerical

  13. Electromagnetic wave matching device

    International Nuclear Information System (INIS)

    Hirata, Yosuke; Mitsunaka, Yoshika; Hayashi, Ken-ichi; Ito, Yasuyuki.

    1997-01-01

    The present invention provides a matching device capable of increasing an efficiency of combining beams of electromagnetic waves outputted from an output window of a gyrotron which is expected for plasma heating of a thermonuclear reactor and an electromagnetic wave transmission system as high as possible. Namely, an electromagnetic wave matching device reflects beams of electromagnetic waves incident from an inlet by a plurality of phase correction mirrors and combines them to an external transmission system through an exit. In this case, the phase correction mirrors change the phase of the beams of electromagnetic waves incident to the phase correction mirrors by a predetermined amount corresponding to the position of the reflection mirrors. Then, the beams of electromagnetic waves outputted, for example, from a gyrotron can properly be shaped as desired for the intensity and the phase. As a result, combination efficiency with the transmission system can be increased. (I.S.)

  14. Electromagnetic ultrasonic guided waves

    CERN Document Server

    Huang, Songling; Li, Weibin; Wang, Qing

    2016-01-01

    This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

  15. Basic Electromagnetism and Materials

    CERN Document Server

    Moliton, André

    2007-01-01

    Basic Electromagnetism and Materials is the product of many years of teaching basic and applied electromagnetism. This textbook can be used to teach electromagnetism to a wide range of undergraduate science majors in physics, electrical engineering or materials science. However, by making lesser demands on mathematical knowledge than competing texts, and by emphasizing electromagnetic properties of materials and their applications, this textbook is uniquely suited to students of materials science. Many competing texts focus on the study of propagation waves either in the microwave or optical domain, whereas Basic Electromagnetism and Materials covers the entire electromagnetic domain and the physical response of materials to these waves. Professor André Moliton is Director of the Unité de Microélectronique, Optoélectronique et Polymères (Université de Limoges, France), which brings together three groups studying the optoelectronics of molecular and polymer layers, micro-optoelectronic systems for teleco...

  16. Fission, fusion and annihilation in the interaction of localized structures for the (2 + 1)-dimensional generalized Broer-Kaup system

    International Nuclear Information System (INIS)

    Yomba, Emmanuel; Peng, Yan-ze

    2006-01-01

    Based on the WTC truncation method and the general variable separation approach (GVSA), we have first found a general solution including three arbitrary functions for the (2 + 1)-dimensional simplified generalized Broer-Kaup (GBK) system (B = 0). A class of double periodic wave solutions is obtained by selecting these arbitrary functions appropriately. The interaction properties of the periodic waves are numerically studied and found to be non-elastic. Limit cases are considered and some new localized coherent structures are obtained, the interaction properties of these solutions reveal that some of them are completely elastic and some are non-completely elastic. After that, starting from the (2 + 1)-dimensional GBK system (B ≠ 0) and using the variable separation approach (VSA) including two arbitrary functions in the general solution, we have constructed by selecting the two arbitrary functions appropriately a rich variety of new coherent structures. The interaction properties of these structures reveal new physical properties like fusion, fission, or both and present mutual annihilation of these solutions as time increasing. The annihilation in this model has found to be rule by the parameter K 1 , when this parameter is taken to be zero, the annihilation disappears in this model and the above mentioned structures recover the solitonic structure properties

  17. Static electromagnetic frequency changers

    CERN Document Server

    Rozhanskii, L L

    1963-01-01

    Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work

  18. Structure and interaction in dense colloidal systems: evaluation of scattering data by the generalized indirect Fourier transformation method

    International Nuclear Information System (INIS)

    Fritz, Gerhard; Glatter, Otto

    2006-01-01

    The generalized indirect Fourier transformation (GIFT) technique is a versatile tool for the evaluation of small angle scattering data. It does not depend on models for the size and shape of the particles and requires model assumptions only for the interaction effects that are typically not as sensitive to the details of the assumptions. We review here the development of the technique from its inception, focusing on the included interaction models for hard, charged and attractive spheres, and lamellae. A considerable number of applications has also been reported ranging from surfactants, emulsions, microemulsions, food science, and ceramics to melts and block-copolymers

  19. Model for Electromagnetic Information Leakage

    OpenAIRE

    Mao Jian; Li Yongmei; Zhang Jiemin; Liu Jinming

    2013-01-01

    Electromagnetic leakage will happen in working information equipments; it could lead to information leakage. In order to discover the nature of information in electromagnetic leakage, this paper combined electromagnetic theory with information theory as an innovative research method. It outlines a systematic model of electromagnetic information leakage, which theoretically describes the process of information leakage, intercept and reproduction based on electromagnetic radiation, and ana...

  20. Dark matter self-interactions from a general spin-0 mediator

    Energy Technology Data Exchange (ETDEWEB)

    Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Wild, Sebastian, E-mail: felix.kahlhoefer@desy.de, E-mail: kai.schmidt-hoberg@desy.de, E-mail: sebastian.wild@desy.de [DESY, Notkestraße 85, D-22607 Hamburg (Germany)

    2017-08-01

    Dark matter particles interacting via the exchange of very light spin-0 mediators can have large self-interaction rates and obtain their relic abundance from thermal freeze-out. At the same time, these models face strong bounds from direct and indirect probes of dark matter as well as a number of constraints on the properties of the mediator. We investigate whether these constraints can be consistent with having observable effects from dark matter self-interactions in astrophysical systems. For the case of a mediator with purely scalar couplings we point out the highly relevant impact of low-threshold direct detection experiments like CRESST-II, which essentially rule out the simplest realization of this model. These constraints can be significantly relaxed if the mediator has CP-violating couplings, but then the model faces strong constraints from CMB measurements, which can only be avoided in special regions of parameter space.