WorldWideScience

Sample records for electromagnetic field solvers

  1. High accuracy electromagnetic field solvers for cylindrical waveguides and axisymmetric structures using the finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Eric Michael [Stanford Univ., CA (United States)

    1993-12-01

    Some two-dimensional finite element electromagnetic field solvers are described and tested. For TE and TM modes in homogeneous cylindrical waveguides and monopole modes in homogeneous axisymmetric structures, the solvers find approximate solutions to a weak formulation of the wave equation. Second-order isoparametric lagrangian triangular elements represent the field. For multipole modes in axisymmetric structures, the solver finds approximate solutions to a weak form of the curl-curl formulation of Maxwell`s equations. Second-order triangular edge elements represent the radial (ρ) and axial (z) components of the field, while a second-order lagrangian basis represents the azimuthal (Φ) component of the field weighted by the radius ρ. A reduced set of basis functions is employed for elements touching the axis. With this basis the spurious modes of the curl-curl formulation have zero frequency, so spurious modes are easily distinguished from non-static physical modes. Tests on an annular ring, a pillbox and a sphere indicate the solutions converge rapidly as the mesh is refined. Computed eigenvalues with relative errors of less than a few parts per million are obtained. Boundary conditions for symmetric, periodic and symmetric-periodic structures are discussed and included in the field solver. Boundary conditions for structures with inversion symmetry are also discussed. Special corner elements are described and employed to improve the accuracy of cylindrical waveguide and monopole modes with singular fields at sharp corners. The field solver is applied to three problems: (1) cross-field amplifier slow-wave circuits, (2) a detuned disk-loaded waveguide linear accelerator structure and (3) a 90° overmoded waveguide bend. The detuned accelerator structure is a critical application of this high accuracy field solver. To maintain low long-range wakefields, tight design and manufacturing tolerances are required.

  2. A high-order relativistic two-fluid electrodynamic scheme with consistent reconstruction of electromagnetic fields and a multidimensional Riemann solver for electromagnetism

    Science.gov (United States)

    Balsara, Dinshaw S.; Amano, Takanobu; Garain, Sudip; Kim, Jinho

    2016-08-01

    In various astrophysics settings it is common to have a two-fluid relativistic plasma that interacts with the electromagnetic field. While it is common to ignore the displacement current in the ideal, classical magnetohydrodynamic limit, when the flows become relativistic this approximation is less than absolutely well-justified. In such a situation, it is more natural to consider a positively charged fluid made up of positrons or protons interacting with a negatively charged fluid made up of electrons. The two fluids interact collectively with the full set of Maxwell's equations. As a result, a solution strategy for that coupled system of equations is sought and found here. Our strategy extends to higher orders, providing increasing accuracy. The primary variables in the Maxwell solver are taken to be the facially-collocated components of the electric and magnetic fields. Consistent with such a collocation, three important innovations are reported here. The first two pertain to the Maxwell solver. In our first innovation, the magnetic field within each zone is reconstructed in a divergence-free fashion while the electric field within each zone is reconstructed in a form that is consistent with Gauss' law. In our second innovation, a multidimensionally upwinded strategy is presented which ensures that the magnetic field can be updated via a discrete interpretation of Faraday's law and the electric field can be updated via a discrete interpretation of the generalized Ampere's law. This multidimensional upwinding is achieved via a multidimensional Riemann solver. The multidimensional Riemann solver automatically provides edge-centered electric field components for the Stokes law-based update of the magnetic field. It also provides edge-centered magnetic field components for the Stokes law-based update of the electric field. The update strategy ensures that the electric field is always consistent with Gauss' law and the magnetic field is always divergence-free. This

  3. A high-order relativistic two-fluid electrodynamic scheme with consistent reconstruction of electromagnetic fields and a multidimensional Riemann solver for electromagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Balsara, Dinshaw S., E-mail: dbalsara@nd.edu [Physics Department, University of Notre Dame (United States); Amano, Takanobu, E-mail: amano@eps.s.u-tokyo.ac.jp [Department of Earth and Planetary Science, University of Tokyo, Tokyo 113-0033 (Japan); Garain, Sudip, E-mail: sgarain@nd.edu [Physics Department, University of Notre Dame (United States); Kim, Jinho, E-mail: jkim46@nd.edu [Physics Department, University of Notre Dame (United States)

    2016-08-01

    In various astrophysics settings it is common to have a two-fluid relativistic plasma that interacts with the electromagnetic field. While it is common to ignore the displacement current in the ideal, classical magnetohydrodynamic limit, when the flows become relativistic this approximation is less than absolutely well-justified. In such a situation, it is more natural to consider a positively charged fluid made up of positrons or protons interacting with a negatively charged fluid made up of electrons. The two fluids interact collectively with the full set of Maxwell's equations. As a result, a solution strategy for that coupled system of equations is sought and found here. Our strategy extends to higher orders, providing increasing accuracy. The primary variables in the Maxwell solver are taken to be the facially-collocated components of the electric and magnetic fields. Consistent with such a collocation, three important innovations are reported here. The first two pertain to the Maxwell solver. In our first innovation, the magnetic field within each zone is reconstructed in a divergence-free fashion while the electric field within each zone is reconstructed in a form that is consistent with Gauss' law. In our second innovation, a multidimensionally upwinded strategy is presented which ensures that the magnetic field can be updated via a discrete interpretation of Faraday's law and the electric field can be updated via a discrete interpretation of the generalized Ampere's law. This multidimensional upwinding is achieved via a multidimensional Riemann solver. The multidimensional Riemann solver automatically provides edge-centered electric field components for the Stokes law-based update of the magnetic field. It also provides edge-centered magnetic field components for the Stokes law-based update of the electric field. The update strategy ensures that the electric field is always consistent with Gauss' law and the magnetic field is

  4. A High-Order Relativistic Two-Fluid Electrodynamic Scheme with Consistent Reconstruction of Electromagnetic Fields and a Multidimensional Riemann Solver for Electromagnetism

    CERN Document Server

    Balsara, Dinshaw S; Garain, Sudip; Kim, Jinho

    2016-01-01

    In various astrophysics settings it is common to have a two-fluid relativistic plasma that interacts with the electromagnetic field. While it is common to ignore the displacement current in the ideal, classical magnetohydrodynamic limit, when the flows become relativistic this approximation is less than absolutely well-justified. In such a situation, it is more natural to consider a positively charged fluid made up of positrons or protons interacting with a negatively charged fluid made up of electrons. The two fluids interact collectively with the full set of Maxwell's equations. As a result, a solution strategy for that coupled system of equations is sought and found here. Our strategy extends to higher orders, providing increasing accuracy. Three important innovations are reported here. In our first innovation, the magnetic field within each zone is reconstructed in a divergence-free fashion while the electric field within each zone is reconstructed in a form that is consistent with Gauss' law. In our seco...

  5. Electromagnetic Fields

    Science.gov (United States)

    ... cancers. Studies in adults did not prove that EMF exposure causes cancer. Some people worry that wireless and cellular phones cause cancer or other health problems. The phones do give off radio-frequency energy (RF), a form of electromagnetic radiation. So far, scientific evidence has not found a ...

  6. Aleph Field Solver Challenge Problem Results Summary

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, Russell [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moore, Stan Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    Aleph models continuum electrostatic and steady and transient thermal fields using a finite-element method. Much work has gone into expanding the core solver capability to support enriched modeling consisting of multiple interacting fields, special boundary conditions and two-way interfacial coupling with particles modeled using Aleph's complementary particle-in-cell capability. This report provides quantitative evidence for correct implementation of Aleph's field solver via order- of-convergence assessments on a collection of problems of increasing complexity. It is intended to provide Aleph with a pedigree and to establish a basis for confidence in results for more challenging problems important to Sandia's mission that Aleph was specifically designed to address.

  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. Electromagnetic fields and interactions

    CERN Document Server

    Becker, Richard L

    1964-01-01

    For more than a century, ""Becker"" and its forerunner, ""Abraham-Becker,"" have served as the bible of electromagnetic theory for countless students. This definitive translation of the physics classic features both volumes of the original text.Volume I, on electromagnetic theory, includes an introduction to vector and tensor calculus, the electrostatic field, electric current and the field, and the theory of relativity. The second volume comprises a self-contained introduction to quantum theory that covers the classical principles of electron theory and quantum mechanics, problems involving

  9. What Are Electromagnetic Fields?

    Science.gov (United States)

    ... them to quickly heat food. At radio frequencies, electric and magnetic fields are closely interrelated and we typically measure their levels as power densities in watts per square metre (W/m 2 ). Key points: The electromagnetic spectrum encompasses both natural and ...

  10. 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...

  11. Electromagnetic fields and waves

    CERN Document Server

    Iskander, Magdy F

    2013-01-01

    The latest edition of Electromagnetic Fields and Waves retains an authoritative, balanced approach, in-depth coverage, extensive analysis, and use of computational techniques to provide a complete understanding of electromagnetic—important to all electrical engineering students. An essential feature of this innovative text is the early introduction of Maxwell's equations, together with the quantifying experimental observations made by the pioneers who discovered electromagnetics. This approach directly links the mathematical relations in Maxwell's equations to real experiments and facilitates a fundamental understanding of wave propagation and use in modern practical applications, especially in today's wireless world. New and expanded topics include the conceptual relationship between Coulomb's law and Gauss's law for calculating electric fields, the relationship between Biot-Savart's and Ampere's laws and their use in calculating magnetic fields from current sources, the development of Faraday's law from e...

  12. Electromagnetic fields and life

    CERN Document Server

    Presman, A S

    1970-01-01

    A broad region of the electromagnetic spectrum long assumed to have no influence on living systems under natural conditions has been critically re-examined over the past decade. This spectral region extends from the superhigh radio frequencies, through de­ creasing frequencies, to and including essentially static electric and magnetic fields. The author of this monograph, A. S. Presman, has reviewed not only the extensive Russian literatur!;"l, but also al­l most equally comprehensively the non-Russian literature, dealing with biological influences of these fields. Treated also is literature shedding some light on possible theoretical foundations for these phenomena. A substantial, rapidly increasing number of studies in many laboratories and countries has now clearly established bio­ logical influences which are independent of the theoretically predictable, simple thermal effects. Indeed many of the effects are produced by field strengths very close to those within the natural environment. The author has,...

  13. S4 : A free electromagnetic solver for layered periodic structures

    Science.gov (United States)

    Liu, Victor; Fan, Shanhui

    2012-10-01

    We describe S4, a free implementation of the Fourier modal method (FMM), which has also been commonly referred to as rigorous coupled wave analysis (RCWA), for simulating electromagnetic propagation through 3D structures with 2D periodicity. We detail design aspects that allow S4 to be a flexible platform for these types of simulations. In particular, we highlight the ability to select different FMM formulations, user scripting, and extensibility of program capabilities for eigenmode computations. Program summary Program title: S4 Catalogue identifier: AEMO_v1_0. Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMO_v1_0..html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License, version 2 No. of lines in distributed program, including test data, etc.: 56910 No. of bytes in distributed program, including test data, etc.: 433883 Distribution format: Programming language: C, C++. Computer: Any computer with a Unix-like environment and a C++ compiler. Developed on 2.3 GHz AMD Phenom 9600. Operating system: Any Unix-like environment; developed under MinGW32 on Windows 7. Has the code been vectorized or parallelized?: Yes. Parallelized using MPI. RAM: Problem dependent (linearly proportional to number of layers and quadratic in number of Fourier components). A single layer calculation with approximately 100 Fourier components uses approximately 10 MB. Classification: 10. Electrostatics and Electromagnetics. External routines: Lua [1] and optionally exploits additional free software packages: FFTW [2], CHOLMOD [3], MPI message-passing interface [4], LAPACK and BLAS linear-algebra software [5], and Kiss FFT [6]. Nature of problem: Time-harmonic electromagnetism in layered bi-periodic structures. Solution method: The Fourier modal method (rigorous coupled wave analysis) and the scattering matrix method. Running time: Problem dependent and highly dependent on quality of the BLAS

  14. Electromagnetic field and cosmic censorship

    CERN Document Server

    Düztaş, Koray

    2013-01-01

    We construct a gedanken experiment in which an extremal Kerr black hole interacts with a test electromagnetic field. Using Teukolsky's solutions for electromagnetic perturbations in Kerr spacetime, and the conservation laws imposed by the energy momentum tensor of the electromagnetic field and the Killing vectors of the spacetime, we prove that this interaction cannot convert the black hole into a naked singularity, thus cosmic censorship conjecture is not violated in this case.

  15. The classical electromagnetic field

    CERN Document Server

    Eyges, Leonard

    2010-01-01

    This excellent text covers a year's course in advanced theoretical electromagnetism, first introducing theory, then its application. Topics include vectors D and H inside matter, conservation laws for energy, momentum, invariance, form invariance, covariance in special relativity, and more.

  16. Electromagnetic field theories for engineering

    CERN Document Server

    Salam, Md Abdus

    2014-01-01

    A four year Electrical and Electronic engineering curriculum normally contains two modules of electromagnetic field theories during the first two years. However, some curricula do not have enough slots to accommodate the two modules. This book, Electromagnetic Field Theories, is designed for Electrical and Electronic engineering undergraduate students to provide fundamental knowledge of electromagnetic fields and waves in a structured manner. A comprehensive fundamental knowledge of electric and magnetic fields is required to understand the working principles of generators, motors and transformers. This knowledge is also necessary to analyze transmission lines, substations, insulator flashover mechanism, transient phenomena, etc. Recently, academics and researches are working for sending electrical power to a remote area by designing a suitable antenna. In this case, the knowledge of electromagnetic fields is considered as important tool.

  17. Electromagnetic fields in biological systems

    CERN Document Server

    Lin, James C

    2016-01-01

    As wireless technology becomes more sophisticated and accessible to more users, the interactions of electromagnetic fields with biological systems have captured the interest not only of the scientific community but also the general public. Unintended or deleterious biological effects of electromagnetic fields and radiation may indicate grounds for health and safety precautions in their use. Spanning static fields to terahertz waves, Electromagnetic Fields in Biological Systems explores the range of consequences these fields have on the human body. With contributions by an array of experts, topics discussed include: Essential interactions and field coupling phenomena, highlighting their importance in research on biological effects and in scientific, industrial, and medical applications Electric field interactions in cells, focusing on ultrashort, pulsed high-intensity fields The effect of exposure to naturally occurring and human-made static, low-frequency, and pulsed magnetic fields in biological systems Dosi...

  18. Self-dual electromagnetic fields

    Science.gov (United States)

    Chubykalo, Andrew E.; Espinoza, Augusto; Kosyakov, B. P.

    2010-08-01

    We demonstrate the utility of self-dual fields in electrodynamics. Stable configurations of free electromagnetic fields can be represented as superpositions of standing waves, each possessing zero Poynting vector and zero orbital angular momentum. The standing waves are themselves superpositions of self-dual and anti-self-dual solutions. The idea of self-duality provides additional insights into the geometrical and spectral properties of stable electromagnetic configurations, such as those responsible for the formation of ball lightning.

  19. 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.

  20. A primer on electromagnetic fields

    CERN Document Server

    Frezza, Fabrizio

    2015-01-01

    This book is a concise introduction to electromagnetics and electromagnetic fields that covers the aspects of most significance for engineering applications by means of a rigorous, analytical treatment. After an introduction to equations and basic theorems, topics of fundamental theoretical and applicative importance, including plane waves, transmission lines, waveguides, and Green's functions, are discussed in a deliberately general way. Care has been taken to ensure that the text is readily accessible and self-consistent, with conservation of the intermediate steps in the analytical derivations. The book offers the reader a clear, succinct course in basic electromagnetic theory. It will also be a useful lookup tool for students and designers.

  1. A Hybrid Solvers Enhanced Integral Equation Domain Decomposition Method for Modeling of Electromagnetic Radiation

    Directory of Open Access Journals (Sweden)

    Ran Zhao

    2015-01-01

    Full Text Available The hybrid solvers based on integral equation domain decomposition method (HS-DDM are developed for modeling of electromagnetic radiation. Based on the philosophy of “divide and conquer,” the IE-DDM divides the original multiscale problem into many closed nonoverlapping subdomains. For adjacent subdomains, the Robin transmission conditions ensure the continuity of currents, so the meshes of different subdomains can be allowed to be nonconformal. It also allows different fast solvers to be used in different subdomains based on the property of different subdomains to reduce the time and memory consumption. Here, the multilevel fast multipole algorithm (MLFMA and hierarchical (H- matrices method are combined in the framework of IE-DDM to enhance the capability of IE-DDM and realize efficient solution of multiscale electromagnetic radiating problems. The MLFMA is used to capture propagating wave physics in large, smooth regions, while H-matrices are used to capture evanescent wave physics in small regions which are discretized with dense meshes. Numerical results demonstrate the validity of the HS-DDM.

  2. Radiofrequency Electromagnetic Field Map of Timisoara

    National Research Council Canada - National Science Library

    N. Stefu; I. Solyom; A. Arama

    2015-01-01

    There are many electromagnetic field (EMF) sources nowadays acting simultaneously, especially in urban areas, making the theoretical estimation of electromagnetic power at ground level very difficult...

  3. Moving Manifolds in Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    David V. Svintradze

    2017-08-01

    Full Text Available We propose dynamic non-linear equations for moving surfaces in an electromagnetic field. The field is induced by a material body with a boundary of the surface. Correspondingly the potential energy, set by the field at the boundary can be written as an addition of four-potential times four-current to a contraction of the electromagnetic tensor. Proper application of the minimal action principle to the system Lagrangian yields dynamic non-linear equations for moving three dimensional manifolds in electromagnetic fields. The equations in different conditions simplify to Maxwell equations for massless three surfaces, to Euler equations for a dynamic fluid, to magneto-hydrodynamic equations and to the Poisson-Boltzmann equation.

  4. Primal Domain Decomposition Method with Direct and Iterative Solver for Circuit-Field-Torque Coupled Parallel Finite Element Method to Electric Machine Modelling

    Directory of Open Access Journals (Sweden)

    Daniel Marcsa

    2015-01-01

    Full Text Available The analysis and design of electromechanical devices involve the solution of large sparse linear systems, and require therefore high performance algorithms. In this paper, the primal Domain Decomposition Method (DDM with parallel forward-backward and with parallel Preconditioned Conjugate Gradient (PCG solvers are introduced in two-dimensional parallel time-stepping finite element formulation to analyze rotating machine considering the electromagnetic field, external circuit and rotor movement. The proposed parallel direct and the iterative solver with two preconditioners are analyzed concerning its computational efficiency and number of iterations of the solver with different preconditioners. Simulation results of a rotating machine is also presented.

  5. Electromagnetic Fields and Cancer

    Science.gov (United States)

    ... to magnetic fields and acute lymphoblastic leukemia in children. New England Journal of Medicine 1997; 337(1):1-7. [PubMed ... Magnetic field exposure and long-term survival among children with leukaemia. British Journal of Cancer 2006; 94(1):161-164. [PubMed ...

  6. Explanations, Education, and Electromagnetic Fields.

    Science.gov (United States)

    Friedman, Sharon M.

    Explaining complex scientific and environmental subjects in the mass media is difficult to do, particularly under such constraints as short deadlines and lack of space or time. When a scientific controversy and human health risk are involved, this becomes an even harder task to accomplish. The subject of electromagnetic fields (EMF) involves…

  7. Electromagnetic fields from two potential fields

    Science.gov (United States)

    Chauca, J.; Doria, R.; Soares, W.

    2012-10-01

    Maxwell electromagnetism is generalized through a model that includes N-potential fields in a same group. Anew rule for the photon field is defined from a fourth interpretation to the light invariance. It becomes a directive particle while others potential fields appears as circumstance particles. Its most primitive coupling is not more with electric charge but with the Noether systemic charge. Studying the case with two potential fields, one derives the corresponding granular and collective electromagnetic fields with antisymmetric and symmetric nature. As a first feature, differently from Maxwell equation such systemic photon field does not follow the expression inversely proportional to the distance. This work calculates the subsequent branch of elecromagnetic fields {→EI-→BI,→e-→b;ɛI,→ɛI,βIij,s,→s,sij}.

  8. Visualising magnetic fields numerical equation solvers in action

    CERN Document Server

    Beeteson, John Stuart

    2001-01-01

    Visualizing Magnetic Fields: Numerical Equation Solvers in Action provides a complete description of the theory behind a new technique, a detailed discussion of the ways of solving the equations (including a software visualization of the solution algorithms), the application software itself, and the full source code. Most importantly, there is a succinct, easy-to-follow description of each procedure in the code.The physicist Michael Faraday said that the study of magnetic lines of force was greatly influential in leading him to formulate many of those concepts that are now so fundamental to our modern world, proving to him their "great utility as well as fertility." Michael Faraday could only visualize these lines in his mind's eye and, even with modern computers to help us, it has been very expensive and time consuming to plot lines of force in magnetic fields

  9. Forces in electromagnetic field and gravitational field

    OpenAIRE

    Weng, Zihua

    2008-01-01

    The force can be defined from the linear momentum in the gravitational field and electromagnetic field. But this definition can not cover the gradient of energy. In the paper, the force will be defined from the energy and torque in a new way, which involves the gravitational force, electromagnetic force, inertial force, gradient of energy, and some other new force terms etc. One of these new force terms can be used to explain why the solar wind varies velocity along the magnetic force line in...

  10. Health hazards and electromagnetic fields.

    Science.gov (United States)

    Saunders, T

    2003-11-01

    Biological rhythms, physical wellbeing and mental states are dependent on our electrical brainwave system interacting with the extremely weak electromagnetic fields generated by the Earth's telluric and Cosmic radiations. In a single generation, since the evolution of humankind over millions of years, we are exposed to a wide range of powerful, artificially generated electromagnetic radiation which adversely affects the subtle balance in nature's energy fields and has become the source of so-called 'diseases of civilization'. This also includes electromagnetic sensitivity. Generally, there is a lack of awareness and understanding of the impact electromagnetic fields can have upon health and wellbeing.Our ancestors were acutely aware that certain locations, were perceived to have a positive energy field which was beneficial to health and vitality. Over time, these areas are now referred to as sacred sites for spiritual ceremony and as healing centres. In contrast, there are other geographical locations that can have a negative effect upon health and these are known as geopathic stress zones. It is believed that such zones can interfere with the brain's normal function that inhibits the release of melatonin and other endocrine secretions needed to replenish the immune system. Geopathic stress can affect animals and plant life as well as human beings and significantly contributes to sick building syndrome (SBS). Whilst there is an increasing body of opinion amongst eminent researchers and scientists who are addressing these issues, the establishment professions are slow to change. However, very gradually, modern allopathic medicine and attitudes are beginning to recognise the extraordinary wisdom and efficacy of ancient traditions such as acupuncture, light, colour and other therapies based on the understanding and treatment of the interaction of a person's electromagnetic subtle body and the immediate environment. These and many other 'complementary' therapies may

  11. A System for Electromagnetic Field Conversion

    DEFF Research Database (Denmark)

    2003-01-01

    A system is provided for conversion of a first electromagnetic field into a desired second electromagnetic field, for example for coupling modes between waveguides or into microstructured waveguides. The system comprises a complex spatial electromagnetic field converter that is positioned...... for reception of at least a part of the first electromagnetic field and that is adapted for conversion of the received field into the desired electromagnetic field, and wherein at least one of the first and second fields matches a mode of a microstructured waveguide. It is an important advantage of the present...

  12. Health effects of electromagnetic fields.

    OpenAIRE

    Peter Gajšek

    1990-01-01

    Abstract: Devices that emit electromagnetic fields (EMF) have become a part of our daily life and can be found in telecommunications, industry, traffic, science, medicine and in every household. Due to the fact that general public is massively exposed to the EMF, even very small health effects could become a serious public health problem. Many studies show that the EMF above a certain threshold can have a negative health impact. The studies, which could explain the question of health risks as...

  13. Do electromagnetic fields induce cancer?

    OpenAIRE

    飯島,純夫; 山縣, 然太朗; 浅香,昭雄

    1996-01-01

    Recently public concern about the carcinogenic effects of electromagnetic fields(EMF) has been increasing. We reviewed the published literature and current problems relating to possible carcinogenic effects of residential and occupational exposure to EMF. There are several suggestions that such an exposure may increase the risk of cancer, but these studies failed to provide conclusive indications. Further studies including improved prospective studies and biological experiments using EMF and ...

  14. Gallilei covariant quantum mechanics in electromagnetic fields

    Directory of Open Access Journals (Sweden)

    H. E. Wilhelm

    1985-01-01

    Full Text Available A formulation of the quantum mechanics of charged particles in time-dependent electromagnetic fields is presented, in which both the Schroedinger equation and wave equations for the electromagnetic potentials are Galilei covariant, it is shown that the Galilean relativity principle leads to the introduction of the electromagnetic substratum in which the matter and electromagnetic waves propagate. The electromagnetic substratum effects are quantitatively significant for quantum mechanics in reference frames, in which the substratum velocity w is in magnitude comparable with the velocity of light c. The electromagnetic substratum velocity w occurs explicitly in the wave equations for the electromagnetic potentials but not in the Schroedinger equation.

  15. Cross-spectral purity of electromagnetic fields.

    Science.gov (United States)

    Hassinen, Timo; Tervo, Jani; Friberg, Ari T

    2009-12-15

    We extend Mandel's scalar-wave concept of cross-spectral purity to electromagnetic fields. We show that in the electromagnetic case, assumptions similar to the scalar cross-spectral purity lead to a reduction formula, analogous with the one introduced by Mandel. We also derive a condition that shows that the absolute value of the normalized zeroth two-point Stokes parameter of two cross-spectrally pure electromagnetic fields is the same for every frequency component of the field. In analogy with the scalar theory we further introduce a measure of the cross-spectral purity of two electromagnetic fields, namely, the degree of electromagnetic cross-spectral purity.

  16. Wireless Phones Electromagnetic Field Radiation Exposure Assessment

    OpenAIRE

    A. D. Usman; W. F.W. Ahmad; M. Z.A.A. Kadir; M. Mokhtar

    2009-01-01

    Problem statement: Inadequate knowledge of electromagnetic field emitted by mobile phones and increased usage at close proximity, created a lot of skepticism and speculations among end users on its safety or otherwise. Approach: In this study, near field electromagnetic field radiation measurements were conducted on different brand of mobile phones in active mode using a tri-axis isotropic probe and electric field meter. Results: The highest electromagnetic field exposure was recorded when th...

  17. Electromagnetic fields, environment and health

    CERN Document Server

    Perrin, Anne

    2013-01-01

    A good number of false ideas are circulating on the effects of non-ionizing radiations on our health, which can lead to an oversimplification of the issue, to potentially dangerous misconceptions or to misleading data analysis. Health effects may be exaggerated, or on the contrary underplayed. The authors of this work (doctors, engineers and researchers) have endeavored to supply validated and easily understandable scientific information on the electromagnetic fields and their biological and health effects. After a general review of the physics of the waves and a presentation of non-ionizing r

  18. Health Effects of Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    Peter Gajšek

    2011-02-01

    Full Text Available Abstract: Devices that emit electromagnetic fields (EMF have become a part of our daily life and can be found in telecommunications, industry, traffic, science, medicine and in every household. Due to the fact that general public is massively exposed to the EMF, even very small health effects could become a serious public health problem. Many studies show that the EMF above a certain threshold can have a negative health impact. The studies, which could explain the question of health risks as a result of chronic exposure to low intensities, are often contradictory and deficient. In this review the state of the art in the field of health risks associated with the EMF exposure in our environment is presented.

  19. Statistical measurements of fast changing electromagnetic fields

    NARCIS (Netherlands)

    Serra, Ramiro; Serra, Ramiro; Leferink, Frank Bernardus Johannes

    2010-01-01

    The present works aims at describing important statistical indexes such as the field uniformity, the field inhomogeneity and the statistics near the cavity walls for a special case of fast changing random electromagnetic fields. We generate this kind of electromagnetic environment by means of a

  20. Electromagnetic fields in stratified media

    CERN Document Server

    Li, Kai

    2009-01-01

    Dealing with an important branch of electromagnetic theory with many useful applications in subsurface communication, radar, and geophysical prospecting and diagnostics, this book introduces electromagnetic theory and wave propagation in complex media.

  1. Advanced field-solver techniques for RC extraction of integrated circuits

    CERN Document Server

    Yu, Wenjian

    2014-01-01

    Resistance and capacitance (RC) extraction is an essential step in modeling the interconnection wires and substrate coupling effect in nanometer-technology integrated circuits (IC). The field-solver techniques for RC extraction guarantee the accuracy of modeling, and are becoming increasingly important in meeting the demand for accurate modeling and simulation of VLSI designs. Advanced Field-Solver Techniques for RC Extraction of Integrated Circuits presents a systematic introduction to, and treatment of, the key field-solver methods for RC extraction of VLSI interconnects and substrate coupling in mixed-signal ICs. Various field-solver techniques are explained in detail, with real-world examples to illustrate the advantages and disadvantages of each algorithm. This book will benefit graduate students and researchers in the field of electrical and computer engineering, as well as engineers working in the IC design and design automation industries. Dr. Wenjian Yu is an Associate Professor at the Department of ...

  2. An iterative parallel sparse matrix equation solver with application to finite element modeling of electromagnetic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Cwik, T.; Jamnejad, V.; Zuffada, C. [California Institute of Technology, Pasadena, CA (United States)

    1994-12-31

    The usefulness of finite element modeling follows from the ability to accurately simulate the geometry and three-dimensional fields on the scale of a fraction of a wavelength. To make this modeling practical for engineering design, it is necessary to integrate the stages of geometry modeling and mesh generation, numerical solution of the fields-a stage heavily dependent on the efficient use of a sparse matrix equation solver, and display of field information. The stages of geometry modeling, mesh generation, and field display are commonly completed using commercially available software packages. Algorithms for the numerical solution of the fields need to be written for the specific class of problems considered. Interior problems, i.e. simulating fields in waveguides and cavities, have been successfully solved using finite element methods. Exterior problems, i.e. simulating fields scattered or radiated from structures, are more difficult to model because of the need to numerically truncate the finite element mesh. To practically compute a solution to exterior problems, the domain must be truncated at some finite surface where the Sommerfeld radiation condition is enforced, either approximately or exactly. Approximate methods attempt to truncate the mesh using only local field information at each grid point, whereas exact methods are global, needing information from the entire mesh boundary. In this work, a method that couples three-dimensional finite element (FE) solutions interior to the bounding surface, with an efficient integral equation (IE) solution that exactly enforces the Sommerfeld radiation condition is developed. The bounding surface is taken to be a surface of revolution (SOR) to greatly reduce computational expense in the IE portion of the modeling.

  3. Tests of a 3D Self Magnetic Field Solver in the Finite Element Gun Code MICHELLE

    CERN Document Server

    Nelson, Eric M

    2005-01-01

    We have recently implemented a prototype 3d self magnetic field solver in the finite-element gun code MICHELLE. The new solver computes the magnetic vector potential on unstructured grids. The solver employs edge basis functions in the curl-curl formulation of the finite-element method. A novel current accumulation algorithm takes advantage of the unstructured grid particle tracker to produce a compatible source vector, for which the singular matrix equation is easily solved by the conjugate gradient method. We will present some test cases demonstrating the capabilities of the prototype 3d self magnetic field solver. One test case is self magnetic field in a square drift tube. Another is a relativistic axisymmetric beam freely expanding in a round pipe.

  4. Medical applications of electromagnetic fields

    Science.gov (United States)

    Lai, Henry C.; Singh, Narendra P.

    2010-04-01

    In this article, we describe two possible applications of low-intensity non-ionizing electromagnetic fields (EMF) for the treatment of malaria and cancer, respectively. In malaria treatment, a low-intensity extremely-low frequency magnetic field can be used to induce vibration of hemozoin, a super-paramagnetic polymer particle, inside malaria parasites. This disturbance could cause free radical and mechanical damages leading to the death of the parasite. This concept has been tested in vitro on malaria parasites and found to be effective. This may provide a low cost effective treatment for malaria infection in humans. The rationale for cancer treatment using low-intensity EMF is based on two concepts that have been well established in the literature: (1) low-intensity non-thermal EMF enhances cytotoxic free radicals via the iron-mediated Fenton reaction; and (2) cancer cells have higher amounts of free iron, thus are more susceptible to the cytotoxic effects of EMF. Since normal cells contain minimal amount of free iron, the effect would be selectively targeting cancer cells. Thus, no adverse side effect would be expected as in traditional chemotherapy and radiation therapy. This concept has also been tested on human cancer cell and normal cells in vitro and proved to be feasible.

  5. Medical applications of electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Henry C; Singh, Narendra P, E-mail: hlai@u.washington.ed [Department of Bioengineering, University of Washington, Seattle, WA 98195-5061 (United States)

    2010-04-15

    In this article, we describe two possible applications of low-intensity non-ionizing electromagnetic fields (EMF) for the treatment of malaria and cancer, respectively. In malaria treatment, a low-intensity extremely-low frequency magnetic field can be used to induce vibration of hemozoin, a super-paramagnetic polymer particle, inside malaria parasites. This disturbance could cause free radical and mechanical damages leading to the death of the parasite. This concept has been tested in vitro on malaria parasites and found to be effective. This may provide a low cost effective treatment for malaria infection in humans. The rationale for cancer treatment using low-intensity EMF is based on two concepts that have been well established in the literature: (1) low-intensity non-thermal EMF enhances cytotoxic free radicals via the iron-mediated Fenton reaction; and (2) cancer cells have higher amounts of free iron, thus are more susceptible to the cytotoxic effects of EMF. Since normal cells contain minimal amount of free iron, the effect would be selectively targeting cancer cells. Thus, no adverse side effect would be expected as in traditional chemotherapy and radiation therapy. This concept has also been tested on human cancer cell and normal cells in vitro and proved to be feasible.

  6. Wavefield transform of electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.H.; Xie, G.Q. [Lawrence Berkeley Lab., CA (United States); Habashy, T.M.; Torres-Verdin, C. [Schlumberger-Doll Research, Ridgefield, CT (United States)

    1994-12-31

    One of the recent developments in electromagnetic (EM) methods for crosshole conductivity imaging involves transformation of diffuse EM fields to wavefields (Lee and Xie, 1993). In this approach the EM fields are first transformed to wavefields. The velocity of the wavefield and the electrical conductivity are related by a simple formula. Using traveltime obtained from the transformed wavefield a ray tomography would be carried out for the wavefield velocity and then the electrical conductivity. From the transformed wavefield only the traveltime is used for the tomographic imaging. This paper examines numerical methods for obtaining travel times by transforming either the time- or the frequency-domain data to wavefields. The number of sample data used for the transform can be as little as ten for the frequency-domain approach and twenty five for the time-domain approach. The accuracy in the traveltime obtained this way seems within one percent provided that the data are sufficiently accurate. The transform originally involves the solution of a Fredholm integral equation of the first kind. Predictably, with lesser amount of data the numerical process becomes more ill-posed.

  7. Marching-on-in-Degree Time-Domain Integral Equation Solver for Transient Electromagnetic Analysis of Graphene

    Directory of Open Access Journals (Sweden)

    Quanquan Wang

    2017-10-01

    Full Text Available The marching-on-in-degree (MOD time-domain integral equation (TDIE solver for the transient electromagnetic scattering of the graphene is presented in this paper. Graphene’s dispersive surface impedance is approximated using rational function expressions of complex conjugate pole-residue pairs with the vector fitting (VF method. Enforcing the surface impedance boundary condition, TDIE is established and solved in the MOD scheme, where the temporal surface impedance is carefully convoluted with the current. Unconditionally stable transient solution in time domain can be ensured. Wide frequency band information is obtained after the Fourier transform of the time domain solution. Numerical results validate the proposed method.

  8. Scattering by an electromagnetic radiation field

    Science.gov (United States)

    Bini, D.; Geralico, A.

    2012-02-01

    Motion of test particles in the gravitational field associated with an electromagnetic plane wave is investigated. The interaction with the radiation field is modeled by a force term à la Poynting-Robertson entering the equations of motion given by the 4-momentum density of radiation observed in the particle’s rest frame with a multiplicative constant factor expressing the strength of the interaction itself. Explicit analytical solutions are obtained. Scattering of fields by the electromagnetic wave, i.e., scalar (spin 0), massless spin (1)/(2) and electromagnetic (spin 1) fields, is studied too.

  9. 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.

  10. Electromagnetic fields stress living cells.

    Science.gov (United States)

    Blank, Martin; Goodman, Reba

    2009-08-01

    Electromagnetic fields (EMF), in both ELF (extremely low frequency) and radio frequency (RF) ranges, activate the cellular stress response, a protective mechanism that induces the expression of stress response genes, e.g., HSP70, and increased levels of stress proteins, e.g., hsp70. The 20 different stress protein families are evolutionarily conserved and act as 'chaperones' in the cell when they 'help' repair and refold damaged proteins and transport them across cell membranes. Induction of the stress response involves activation of DNA, and despite the large difference in energy between ELF and RF, the same cellular pathways respond in both frequency ranges. Specific DNA sequences on the promoter of the HSP70 stress gene are responsive to EMF, and studies with model biochemical systems suggest that EMF could interact directly with electrons in DNA. While low energy EMF interacts with DNA to induce the stress response, increasing EMF energy in the RF range can lead to breaks in DNA strands. It is clear that in order to protect living cells, EMF safety limits must be changed from the current thermal standard, based on energy, to one based on biological responses that occur long before the threshold for thermal changes.

  11. Nanomechanical electric and electromagnetic field sensor

    Science.gov (United States)

    Datskos, Panagiotis George; Lavrik, Nickolay

    2015-03-24

    The present invention provides a system for detecting and analyzing at least one of an electric field and an electromagnetic field. The system includes a micro/nanomechanical oscillator which oscillates in the presence of at least one of the electric field and the electromagnetic field. The micro/nanomechanical oscillator includes a dense array of cantilevers mounted to a substrate. A charge localized on a tip of each cantilever interacts with and oscillates in the presence of the electric and/or electromagnetic field. The system further includes a subsystem for recording the movement of the cantilever to extract information from the electric and/or electromagnetic field. The system further includes a means of adjusting a stiffness of the cantilever to heterodyne tune an operating frequency of the system over a frequency range.

  12. [Health effects of electromagnetic fields].

    Science.gov (United States)

    Röösli, Martin

    2013-12-01

    Use of electricity causes extremely low frequency magnetic fields (ELF-MF) and wireless communication devices emit radiofrequency electromagnetic fields (RF-EMF). Average ELF-MF exposure is mainly determined by high voltage power lines and transformers at home or at the workplace, whereas RF-EMF exposure is mainly caused by devices operating close to the body (mainly mobile and cordless phones). Health effects of EMF are controversially discussed. The IARC classified ELF-MF and RF-EMF as possible carcinogenic. Most consistent epidemiological evidence was found for an association between ELF-MF and childhood leukaemia. If causal, 1 - 4 percent of all childhood leukaemia cases could be attributed to ELF-MF. Epidemiological research provided some indications for an association between ELF-MF and Alzheimer's diseases as well as amyotrophic lateral sclerosis, although not entirely consistent. Regarding mobile phones and brain tumours, some studies observed an increased risk after heavy or long term use on the one hand. On the other hand, brain tumour incidence was not found to have increased in the last decade in Sweden, England or the US. Acute effects of RF-EMF on non-specific symptoms of ill health seem unlikely according to randomized and double blind provocation studies. However, epidemiological research on long term effects is still limited. Although from the current state of the scientific knowledge a large individual health risk from RF-EMF exposure is unlikely, even a small risk would have substantial public health relevance because of the widespread use of wireless communication technologies.

  13. A new solver for granular avalanche simulation: Indoor experiment verification and field scale case study

    Science.gov (United States)

    Wang, XiaoLiang; Li, JiaChun

    2017-12-01

    A new solver based on the high-resolution scheme with novel treatments of source terms and interface capture for the Savage-Hutter model is developed to simulate granular avalanche flows. The capability to simulate flow spread and deposit processes is verified through indoor experiments of a two-dimensional granular avalanche. Parameter studies show that reduction in bed friction enhances runout efficiency, and that lower earth pressure restraints enlarge the deposit spread. The April 9, 2000, Yigong avalanche in Tibet, China, is simulated as a case study by this new solver. The predicted results, including evolution process, deposit spread, and hazard impacts, generally agree with site observations. It is concluded that the new solver for the Savage-Hutter equation provides a comprehensive software platform for granular avalanche simulation at both experimental and field scales. In particular, the solver can be a valuable tool for providing necessary information for hazard forecasts, disaster mitigation, and countermeasure decisions in mountainous areas.

  14. Lorentz transformations for whole electromagnetic fields

    Science.gov (United States)

    Chauca, J.; Doria, R.; Soares, W.

    2012-10-01

    A fourth light interpretation leads on the presence of fields with a same Lorentz nature. It says that Lorentz representations should be associated to a fields family. Studying on the (1/2,1/2) representation there is a potential fields family {AμI} which brings the presence of the so-called whole electromagnetism. Thus, the electromagnetic phenomena is extended from Maxwell. From the original fields set {AμI}, it appears new electromagnetic fields, sectors and charges that go beyond to the usual pair {→E-→B} to a new branch of electromagnetic fields {→EI-→BI,→e-→b;ɛI,→ɛI,βIij,s,→s,sij}, new electromagnetic sectors identified as photonic, massive, neutral which bring anothers contributions to that one given by the electric charge, as charges and currents depending on fields. Also the Lorentz force is extended. This work motivation is to study on the corresponding Lorentz transformations. Describe how these whole electromagnetic fields and forces transform under Lorentz transformations and invariants are obtained.

  15. Electromagnetic measurements in the near field

    CERN Document Server

    Bienkowski, Pawel

    2012-01-01

    This book is devoted to the specific problems of electromagnetic field (EMF) measurements in the near field and to the analysis of the main factors which impede accuracy in these measurements. It focuses on careful and accurate design of systems to measure in the near field based on a thorough understanding of the fundamental engineering principles and on an analysis of the likely system errors. Beginning with a short introduction to electromagnetic fields with an emphasis on the near field, it them presents methods of EMF measurements in near field conditions. It details the factors limiting

  16. Electromagnetic Field Theory A Collection of Problems

    CERN Document Server

    Mrozynski, Gerd

    2013-01-01

    After a brief introduction into the theory of electromagnetic fields and the definition of the field quantities the book teaches the analytical solution methods of Maxwell’s equations by means of several characteristic examples. The focus is on static and stationary electric and magnetic fields, quasi stationary fields, and electromagnetic waves. For a deeper understanding, the many depicted field patterns are very helpful. The book offers a collection of problems and solutions which enable the reader to understand and to apply Maxwell’s theory for a broad class of problems including classical static problems right up to waveguide eigenvalue problems. Content Maxwell’s Equations - Electrostatic Fields - Stationary Current Distributions – Magnetic Field of Stationary Currents – Quasi Stationary Fields: Eddy Currents - Electromagnetic Waves Target Groups Advanced Graduate Students in Electrical Engineering, Physics, and related Courses Engineers and Physicists Authors Professor Dr.-Ing. Gerd Mrozynski...

  17. Electromagnetic field computation by network methods

    CERN Document Server

    Felsen, Leopold B; Russer, Peter

    2009-01-01

    This monograph proposes a systematic and rigorous treatment of electromagnetic field representations in complex structures. The book presents new strong models by combining important computational methods. This is the last book of the late Leopold Felsen.

  18. Correlations of electromagnetic fields in chaotic cavities

    CERN Document Server

    Eckhardt, B; Kühl, T; Stöckmann, H J

    1999-01-01

    We consider the fluctuations of electromagnetic fields in chaotic microwave cavities. We calculate the transversal and longitudinal correlation function based on a random wave assumption and compare the predictions with measurements on two- and three-dimensional microwave cavities.

  19. Time Domain Surface Integral Equation Solvers for Quantum Corrected Electromagnetic Analysis of Plasmonic Nanostructures

    KAUST Repository

    Uysal, Ismail Enes

    2016-10-01

    Plasmonic structures are utilized in many applications ranging from bio-medicine to solar energy generation and transfer. Numerical schemes capable of solving equations of classical electrodynamics have been the method of choice for characterizing scattering properties of such structures. However, as dimensions of these plasmonic structures reduce to nanometer scale, quantum mechanical effects start to appear. These effects cannot be accurately modeled by available classical numerical methods. One of these quantum effects is the tunneling, which is observed when two structures are located within a sub-nanometer distance of each other. At these small distances electrons “jump" from one structure to another and introduce a path for electric current to flow. Classical equations of electrodynamics and the schemes used for solving them do not account for this additional current path. This limitation can be lifted by introducing an auxiliary tunnel with material properties obtained using quantum models and applying a classical solver to the structures connected by this auxiliary tunnel. Early work on this topic focused on quantum models that are generated using a simple one-dimensional wave function to find the tunneling probability and assume a simple Drude model for the permittivity of the tunnel. These tunnel models are then used together with a classical frequency domain solver. In this thesis, a time domain surface integral equation solver for quantum corrected analysis of transient plasmonic interactions is proposed. This solver has several advantages: (i) As opposed to frequency domain solvers, it provides results at a broad band of frequencies with a single simulation. (ii) As opposed to differential equation solvers, it only discretizes surfaces (reducing number of unknowns), enforces the radiation condition implicitly (increasing the accuracy), and allows for time step selection independent of spatial discretization (increasing efficiency). The quantum model

  20. Electromagnetic radiation field of an electron avalanche

    Science.gov (United States)

    Cooray, Vernon; Cooray, Gerald

    2012-11-01

    Electron avalanches are the main constituent of electrical discharges in the atmosphere. However, the electromagnetic radiation field generated by a single electron avalanche growing in different field configurations has not yet been evaluated in the literature. In this paper, the electromagnetic radiation fields created by electron avalanches were evaluated for electric fields in pointed, co-axial and spherical geometries. The results show that the radiation field has a duration of approximately 1-2 ns, with a rise time in the range of 0.25 ns. The wave-shape takes the form of an initial peak followed by an overshoot in the opposite direction. The electromagnetic spectrum generated by the avalanches has a peak around 109 Hz.

  1. INVESTIGATION OF ELECTROMAGNETIC FIELDS IN RESIDENTIAL AREAS

    Directory of Open Access Journals (Sweden)

    Dušan MEDVEĎ

    2017-09-01

    Full Text Available This article is devoted to investigation of impact of electromagnetic fields around the electrical equipment used in a residential area and their impact on the human body. This paper was based on sets of measurements of magnetic induction B with magnetometer and on computational simulations in ANSYS for particular appliances often used in household. The results from measurements and simulations led to setting out the recommendations for practical action in the form of elimination of harmful electromagnetic radiation.

  2. A precise electromagnetic field model useful for development of microwave imaging systems

    DEFF Research Database (Denmark)

    Chaber, Bartosz; Mohr, Johan Jacob

    2016-01-01

    Purpose - The paper describes a fast forward electromagnetic model built with help of commercial software. The purpose of this paper is to create an efficient and robust electromagnetic field model that could be easily plugged into a working microwave imaging system. The secondary purpose...... was created in an iterative fashion in order to determine how much details are needed to make it reliable, while keeping it efficient.Findings - The authors found that the commercial software seems like a viable platform for developing electromagnetic solvers. The resulting computer model is easy to prepare...... preparation and data visualization.Practical implications - One of the main advantages of using such a full field electromagnetic model is the ability to investigate an impact of different properties of the system ( length of antennas, liquid parameters) on its performance. Thanks to the use of commercial...

  3. Electromagnetic fields in fractal continua

    Energy Technology Data Exchange (ETDEWEB)

    Balankin, Alexander S., E-mail: abalankin@ipn.mx [Grupo “Mecánica Fractal”, Instituto Politécnico Nacional, México D.F., 07738 Mexico (Mexico); Mena, Baltasar [Instituto de Ingeniería, Universidad Nacional Autónoma de México, México D.F. (Mexico); Patiño, Julián [Grupo “Mecánica Fractal”, Instituto Politécnico Nacional, México D.F., 07738 Mexico (Mexico); Morales, Daniel [Instituto Mexicano del Petróleo, México D.F., 07730 Mexico (Mexico)

    2013-04-01

    Fractal continuum electrodynamics is developed on the basis of a model of three-dimensional continuum Φ{sub D}{sup 3}⊂E{sup 3} with a fractal metric. The generalized forms of Maxwell equations are derived employing the local fractional vector calculus related to the Hausdorff derivative. The difference between the fractal continuum electrodynamics based on the fractal metric of continua with Euclidean topology and the electrodynamics in fractional space F{sup α} accounting the fractal topology of continuum with the Euclidean metric is outlined. Some electromagnetic phenomena in fractal media associated with their fractal time and space metrics are discussed.

  4. Differential form representation of stochastic electromagnetic fields

    Directory of Open Access Journals (Sweden)

    M. Haider

    2017-09-01

    Full Text Available In this work, we revisit the theory of stochastic electromagnetic fields using exterior differential forms. We present a short overview as well as a brief introduction to the application of differential forms in electromagnetic theory. Within the framework of exterior calculus we derive equations for the second order moments, describing stochastic electromagnetic fields. Since the resulting objects are continuous quantities in space, a discretization scheme based on the Method of Moments (MoM is introduced for numerical treatment. The MoM is applied in such a way, that the notation of exterior calculus is maintained while we still arrive at the same set of algebraic equations as obtained for the case of formulating the theory using the traditional notation of vector calculus. We conclude with an analytic calculation of the radiated electric field of two Hertzian dipole, excited by uncorrelated random currents.

  5. Differential form representation of stochastic electromagnetic fields

    Science.gov (United States)

    Haider, Michael; Russer, Johannes A.

    2017-09-01

    In this work, we revisit the theory of stochastic electromagnetic fields using exterior differential forms. We present a short overview as well as a brief introduction to the application of differential forms in electromagnetic theory. Within the framework of exterior calculus we derive equations for the second order moments, describing stochastic electromagnetic fields. Since the resulting objects are continuous quantities in space, a discretization scheme based on the Method of Moments (MoM) is introduced for numerical treatment. The MoM is applied in such a way, that the notation of exterior calculus is maintained while we still arrive at the same set of algebraic equations as obtained for the case of formulating the theory using the traditional notation of vector calculus. We conclude with an analytic calculation of the radiated electric field of two Hertzian dipole, excited by uncorrelated random currents.

  6. Electromagnetic field standards and exposure systems

    CERN Document Server

    Grudzinski, Eugeniusz

    2013-01-01

    When measuring electromagnetic fields (EMF), there are multiple factors that affect accuracy. Everything from proper instrument calibration, to external environmental factors, and even the competence and training of the instrument operator can bring precision into question. This book discusses factors that limit accuracy of electromagnetic field standards. These standards are one of the least accurate among the standards of physical magnitudes. They limit the accuracy of the EMF measurements, as well as the accuracy of the standards' use as exposure systems in a wide range of experiments in el

  7. Scattering by an electromagnetic radiation field

    OpenAIRE

    Bini, Donato; Geralico, Andrea

    2014-01-01

    Motion of test particles in the gravitational field associated with an electromagnetic plane wave is investigated. The interaction with the radiation field is modeled by a force term {\\it \\`a la} Poynting-Robertson entering the equations of motion given by the 4-momentum density of radiation observed in the particle's rest frame with a multiplicative constant factor expressing the strength of the interaction itself. Explicit analytical solutions are obtained. Scattering of fields by the elect...

  8. Electromagnetics

    CERN Document Server

    Rothwell, Edward J

    2009-01-01

    Introductory concepts Notation, conventions, and symbology The field concept of electromagneticsThe sources of the electromagnetic field Problems Maxwell's theory of electromagnetism The postulate Maxwell's equations in moving frames The Maxwell-Boffi equations Large-scale form of Maxwell's equationsThe nature of the four field quantities Maxwell's equations with magnetic sources Boundary (jump) conditions Fundamental theorems The wave nature of the electromagnetic field ProblemsThe static electromagnetic field Static fields and steady currents ElectrostaticsMagnetostatics Static field theorem

  9. Gene transcription and electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, A.S.

    1992-01-01

    Our overall aim is to obtain sufficient information to allow us to ultimately determine whether ELF EM field exposure is an initiating factor in neoplastic transformation and/or if exposure can mimic characteristics of the second-step counterpart in neoplastic disease. This aim is based on our previous findings that levels of some transcripts are increased in cells exposed to EM fields. While the research is basic in nature, the ramifications have bearing on the general safety of exposure to EM fields in industrial and everyday life. A large array of diverse biological effects are reported to occur as the result of exposure to elf EM fields, suggesting that the cell response to EM fields is at a basic level, presumably initiated by molecular and/or biophysical events at the cell membrane. The hypothesized route is a signal transduction pathway involving membrane calcium fluxes. Information flow resulting from signal transduction can mediate the induction of regulatory factors in the cell, and directly affect how transcription is regulated.

  10. Mortality in workers exposed to electromagnetic fields.

    OpenAIRE

    Milham, S

    1985-01-01

    In an occupational mortality analysis of 486,000 adult male death records filed in Washington State in the years 1950-1982, leukemia and the non-Hodgkin's lymphomas show increased proportionate mortality ratios (PMRs) in workers employed in occupations with intuitive exposures to electromagnetic fields. Nine occupations of 219 were considered to have electric or magnetic field exposures. These were: electrical and electronic technicians, radio and telegraph operators, radio and television rep...

  11. Topology optimization of nanoparticles for localized electromagnetic field enhancement

    DEFF Research Database (Denmark)

    Christiansen, Rasmus Ellebæk; Vester-Petersen, Joakim; Madsen, Søren Peder

    2017-01-01

    We consider the design of individual and periodic arrangements of metal or semiconductor nanoparticles for localized electromagnetic field enhancement utilizing a topology optimization based numerical framework as the design tool. We aim at maximizing a function of the electromagnetic field...

  12. Electromagnetic field induced biological effects in humans.

    Science.gov (United States)

    Kaszuba-Zwoińska, Jolanta; Gremba, Jerzy; Gałdzińska-Calik, Barbara; Wójcik-Piotrowicz, Karolina; Thor, Piotr J

    2015-01-01

    Exposure to artificial radio frequency electromagnetic fields (EMFs) has increased significantly in recent decades. Therefore, there is a growing scientific and social interest in its influence on health, even upon exposure significantly below the applicable standards. The intensity of electromagnetic radiation in human environment is increasing and currently reaches astronomical levels that had never before experienced on our planet. The most influential process of EMF impact on living organisms, is its direct tissue penetration. The current established standards of exposure to EMFs in Poland and in the rest of the world are based on the thermal effect. It is well known that weak EMF could cause all sorts of dramatic non-thermal effects in body cells, tissues and organs. The observed symptoms are hardly to assign to other environmental factors occurring simultaneously in the human environment. Although, there are still ongoing discussions on non-thermal effects of EMF influence, on May 31, 2011--International Agency for Research on Cancer (IARC)--Agenda of World Health Organization (WHO) has classified radio electromagnetic fields, to a category 2B as potentially carcinogenic. Electromagnetic fields can be dangerous not only because of the risk of cancer, but also other health problems, including electromagnetic hypersensitivity (EHS). Electromagnetic hypersensitivity (EHS) is a phenomenon characterized by the appearance of symptoms after exposure of people to electromagnetic fields, generated by EHS is characterized as a syndrome with a broad spectrum of non-specific multiple organ symptoms including both acute and chronic inflammatory processes located mainly in the skin and nervous systems, as well as in respiratory, cardiovascular systems, and musculoskeletal system. WHO does not consider the EHS as a disease-- defined on the basis of medical diagnosis and symptoms associated with any known syndrome. The symptoms may be associated with a single source of EMF

  13. Immunity of electronic devices against radio-frequency electromagnetic fields

    Directory of Open Access Journals (Sweden)

    Urbancokova Hana

    2017-01-01

    Full Text Available One of the major types of electromagnetic interference, which affect electronic devices in their normal operation, is the interference with radio-frequency electromagnetic fields. This interference is generated by the mainly radio and television transmitters, industrial equipment and other transmitters and receivers in general use for communication. Testing of electromagnetic susceptibility of electronic devices on radiated radio-frequency electromagnetic field is governed by the basic standard IEC 61000-4-3 and the equipment under test are exposed to test electromagnetic fields with an intensity from 1 V/m to 30 V/m, the most often in the frequency range from 80 MHz to 2 GHz. The aim of this paper is to explain the issue of electromagnetic susceptibility and to present sample the electromagnetic immunity tests of the basic set of the intrusion and hold-up alarm system against the radio-frequency electromagnetic field according to the relevant electromagnetic compatibility standards.

  14. Industrialization, electromagnetic fields, and breast cancer risk.

    OpenAIRE

    Kheifets, L I; Matkin, C C

    1999-01-01

    The disparity between the rates of breast cancer in industrialized and less-industrialized regions has led to many hypotheses, including the theory that exposure to light-at-night and/or electromagnetic fields (EMF) may suppress melatonin and that reduced melatonin may increase the risk of breast cancer. In this comprehensive review we consider strengths and weaknesses of more than 35 residential and occupational epidemiologic studies that investigated the association between EMF and breast c...

  15. [Safety and electromagnetic compatibility in sanitary field].

    Science.gov (United States)

    Bini, M; Feroldi, P; Ferri, C; Ignesti, A; Olmi, R; Priori, S; Riminesi, C; Tobia, L

    2012-01-01

    In sanitary field and especially in a hospital, multiple sources of non ionizing radiation are used for diagnostic and therapeutic aims. In sanitary sector both workers and users are present at the same time, and in some cases general population could need higher protection than workers in relationship to the exposition to electromagnetic fields. In order to protect health and safety of patients, general population and workers of hospitals and with the aim to identify, analyze, evaluate and study its level of significance, electrical, magnetic and electromagnetic sources Research Italian project Si.C.E.O. (Safety And Electromagnetic Compatibility In Sanitary Field) was instituted. Target of our research project was to deepen risk of exposition elements with analysis of outdoor (e.g. power lines, transmission cabinets) and indoor (e.g. equipment for physical therapy) sources, located in sanitary structures and to verify the level exposition of workers and common population end the respect of specific regulation, and finally to define technical and organizational measures really useful for protection and reduction of risk.

  16. Myocardial protection conferred by electromagnetic fields.

    Science.gov (United States)

    DiCarlo, A L; Farrell, J M; Litovitz, T A

    1999-02-16

    It has been reported that electromagnetic (EM) fields induce stress proteins in vitro. These proteins have been shown to be important in recovery from ischemia/reperfusion. It was, therefore, hypothesized that EM fields could activate stress responses in vivo and protect myocardial tissue during anoxia. Chick embryos were exposed to 4-, 6-, 8-, and 10- microT and 60-Hz EM fields for 20 minutes followed by a 1-hour rest period before placement in an anoxic chamber. Embryos were reoxygenated when survival of controls dropped to 500 EM field-exposed embryos) indicated that EM field protection was extremely significant (Pmyocardium from anoxia damage. These results suggest that EM field exposures may be a useful, noninvasive means of minimizing myocardial damage during surgery, transplantation, or heart attack in humans.

  17. Effect of remote field electromagnetic boundary conditions on microwave-induced plasma torches

    Science.gov (United States)

    Jimenez-Diaz, M.; van Dijk, J.; van der Mullen, J. J. A. M.

    2011-04-01

    A flexible versatile electromagnetic model constructed with the PLASIMO platform is employed to explore electromagnetic features of microwave-induced plasma torches. The bases, formed by a full-vector formulation of the Maxwell equations, provide the possibility to formulate the boundary conditions in a natural way. Together with the use of a direct matrix solver this gives a convergence speed-up of more than a factor of 100 when compared with a scalar formulation on an azimuthal magnetic field that uses an iterative solver. As a result, this electromagnetic model is ready to act in future studies as part of the self-consistent description of plasma-electromagnetic coupling. With the electromagnetic model three types of configuration were studied: the closed, semi-open and open configurations, all three based on the same simplified model plasmas. It is found that the closed configuration, acting as a cavity for which (de)tuning is extremely sensitive for the plasma conditions, is less suitable for applications in which changes in plasma compositions can be expected. The semi-open configuration can be seen as a model for the practice often used in laboratories to place microwave-induced plasma torches in a grid that aims at protecting the environment against microwave electromagnetic radiation. Calculations show that this is good practice provided the radius of this cylindrical grid is in the order of 90 mm. For the most often used configuration, the open version, we found that the power balance as expressed by the coefficients of absorption, transmission and reflection depends on the electron density of the plasma. The reason is that the plasma acts as an antenna, which converts the electromagnetic waves from the coaxial structure to that of the expansion region, and that this antenna function depends on the electron density. The influence of various other antenna elements is investigated as well.

  18. The automatic electromagnetic field generating system

    Science.gov (United States)

    Audone, B.; Gerbi, G.

    1982-07-01

    The technical study and the design approaches adopted for the definition of the automatic electromagnetic field generating system (AEFGS) dedicated to EMC susceptibility testing are presented. The AEFGS covers the frequency range 10 KHz to 40 GHZ and operates successfully in the two EMC shielded chambers at ESTEC. The performance of the generators/amplifiers subsystems, antennas selection, field amplitude and susceptibility feedback and monitoring systems is described. System control modes which guarantee the AEFGS full operability under different test conditions are discussed. Advantages of automation of susceptibility testing include increased measurement accuracy and testing cost reduction.

  19. On electromagnetic field problems in inhomogeneous media

    Science.gov (United States)

    Mohsen, A.

    1973-01-01

    Analysis of electromagnetic fields in inhomogeneous media is of practical interest in general scattering and propagation problems and in the study of lenses. For certain types of inhomogeneities, the fields may be represented in terms of two scalars. In a general orthogonal coordinate system, these potentials satisfy second order differential equations. Exact solutions of these equations are known only for a few particular cases and in general, an approximate or numerical technique must be employed. The present work reviews and generalizes some of the main methods of attack of the problem. The results are presented in a form appropriate for numerical computation.

  20. Electromagnetic fields, pacemakers and defibrillators; Champs electromagnetiques, cardiostimulateurs et defibrillateurs

    Energy Technology Data Exchange (ETDEWEB)

    Guiguet, J.C. [Agence Nationale des Frequences (ANFR), 94 - Maisons Alfort (France); Dodinot, B.; Sadoul, N.; Blangy, H. [Centre Hospitalier Universitaire Nancy-Brabois, Clinique Cardiologique, 54 - Vandoeuvre Brabois (France); Nadi, M.; Hedjiedj, A.; Schmitt, P. [Universite Henri Poincare-Nancy, Lab. d' Instrumentation Electronique de Nancy, Faculte des Sciences, 54 - Vandoeuvre les Nancy (France); Joly, L.; Dodinot, B.; Aliot, E. [Centre Hospitalier Universitaire Nancy-Brabois, Service de Cardiologie, 54 - Vandoeuvre-les-Nancy (France); Silny, J. [Aachen University (Germany); Franck, R.; Himbert, C.; Hidden-Lucet, F.; Petitot, J.C.; Fontaine, G. [Hopital Pitie-Salpetriere, Institut de Cardiologie, Service de Rythmologie, 75 - Paris (France); Souques, M.; Lambrozo, J. [Electricite de France (EDF-Gaz de France), Service des Etudes Medicales, 75 - Paris (France); Magne, I.; Bailly, J.M. [Electricite de France (EDF-Gaz de France), Div. Recherche Developpement, 77 - Moret sur Loing (France); Trigano, J.A. [Centre Hospitalier Universitaire, Hopital Nord, 13 - Marseille (France); Burais, N. [CEGELY, Ecole Centrale de Lyon, 69 - Ecully (France); Gaspard, J.Y. [Magtech, 69 - Ecully (France); Andrivet, Ph. [Societe Medtronic France, 92 - Boulogne-Billancourt (France)

    2004-07-01

    Presentation of electromagnetic sources constituted by various radio transmitters contributing to different radio communication services in the environment. Results of a measures campaign to assess the electromagnetic field in the close neighbourhood of various stations. Analysis by frequency domains. (author)

  1. 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.

  2. Validation of numerical solvers for liquid metal flow in a complex geometry in the presence of a strong magnetic field

    Science.gov (United States)

    Patel, Anita; Pulugundla, Gautam; Smolentsev, Sergey; Abdou, Mohamed; Bhattacharyay, Rajendraprasad

    2017-11-01

    Following the magnetohydrodynamic (MHD) code validation and verification proposal by Smolentsev et al. (Fusion Eng Des 100:65-72, 2015), we perform code to code and code to experiment comparisons between two computational solvers, FLUIDYN and HIMAG, which are presently considered as two of the prospective CFD tools for fusion blanket applications. In such applications, an electrically conducting breeder/coolant circulates in the blanket ducts in the presence of a strong plasma-confining magnetic field at high Hartmann numbers, Ha (Ha^2 is the ratio between electromagnetic and viscous forces) and high interaction parameters, N (N is the ratio of electromagnetic to inertial forces). The main objective of this paper is to provide the scientific and engineering community with common references to assist fusion researchers in the selection of adequate computational means to be used for blanket design and analysis. As an initial validation case, the two codes are applied to the classic problem of a laminar fully developed MHD flows in a rectangular duct. Both codes demonstrate a very good agreement with the analytical solution for Ha up to 15, 000. To address the capabilities of the two codes to properly resolve complex geometry flows, we consider a case of three-dimensional developing MHD flow in a geometry comprising of a series of interconnected electrically conducting rectangular ducts. The computed electric potential distributions for two flows (Case A) Ha=515 , N=3.2 and (Case B) Ha=2059 , N=63.8 are in very good agreement with the experimental data, while the comparisons for the MHD pressure drop are still unsatisfactory. To better interpret the observed differences, the obtained numerical data are analyzed against earlier theoretical and experimental studies for flows that involve changes in the relative orientation between the flow and the magnetic field.

  3. Electromagnetic Fields and Waves in Fractional Dimensional Space

    CERN Document Server

    Zubair, Muhammad; Naqvi, Qaisar Abbas

    2012-01-01

    This book presents the concept of fractional dimensional space applied to the use of electromagnetic fields and waves. It provides demonstrates the advantages in studying the behavior of electromagnetic fields and waves in fractal media. The book presents novel fractional space generalization of the differential electromagnetic equations is provided as well as a new form of vector differential operators is formulated in fractional space. Using these modified vector differential operators, the classical Maxwell's electromagnetic equations are worked out. The Laplace's, Poisson's and Helmholtz's

  4. Spherical space Bessel-Legendre-Fourier localized modes solver for electromagnetic waves.

    Science.gov (United States)

    Alzahrani, Mohammed A; Gauthier, Robert C

    2015-10-05

    Maxwell's vector wave equations are solved for dielectric configurations that match the symmetry of a spherical computational domain. The electric or magnetic field components and the inverse of the dielectric profile are series expansion defined using basis functions composed of the lowest order spherical Bessel function, polar angle single index dependant Legendre polynomials and azimuthal complex exponential (BLF). The series expressions and non-traditional form of the basis functions result in an eigenvalue matrix formulation of Maxwell's equations that are relatively compact and accurately solvable on a desktop PC. The BLF matrix returns the frequencies and field profiles for steady states modes. The key steps leading to the matrix populating expressions are provided. The validity of the numerical technique is confirmed by comparing the results of computations to those published using complementary techniques.

  5. Degassing of Bioliquids in Low Electromagnetic Fields

    CERN Document Server

    Shatalov, Vladimir; Zinchenko, Alina

    2011-01-01

    A similarity of changes in physical-chemical properties of pure water induced by low electromagnetic fields (EMF) and by degassing treatment brought us to a conclusion that EMF produces some degassing of water. Degassing in turn gives rise to some biological effects by increasing the surface tension and activity of dissolved ions. In such a way the degassing can modify conformations of proteins and others biomolecules in bioliquids. That was confirmed in our observation of changes in the erythrocyte sedimentation rate and the prothrombinase activity in blood clotting processes.

  6. Electromagnetic Processes in strong Crystalline Fields

    CERN Multimedia

    2007-01-01

    We propose a number of new investigations on aspects of radiation from high energy electron and positron beams (10-300 GeV) in single crystals and amorphous targets. The common heading is radiation emission by electrons and positrons in strong electromagnetic fields, but as the setup is quite versatile, other related phenomena in radiation emission can be studied as well. The intent is to clarify the role of a number of important aspects of radiation in strong fields as e.g. observed in crystals. We propose to measure trident 'Klein-like' production in strong crystalline fields, 'crystalline undulator' radiation, 'sandwich' target phenomena, LPM suppression of pair production as well as axial and planar effects in contributions of spin to the radiation.

  7. Computation of Electromagnetic Fields Scattered From Dielectric Objects of Uncertain Shapes Using MLMC

    KAUST Repository

    Litvinenko, Alexander

    2015-01-07

    Simulators capable of computing scattered fields from objects of uncertain shapes are highly useful in electromagnetics and photonics, where device designs are typically subject to fabrication tolerances. Knowledge of statistical variations in scattered fields is useful in ensuring error-free functioning of devices. Oftentimes such simulators use a Monte Carlo (MC) scheme to sample the random domain, where the variables parameterize the uncertainties in the geometry. At each sample, which corresponds to a realization of the geometry, a deterministic electromagnetic solver is executed to compute the scattered fields. However, to obtain accurate statistics of the scattered fields, the number of MC samples has to be large. This significantly increases the total execution time. In this work, to address this challenge, the Multilevel MC (MLMC [1]) scheme is used together with a (deterministic) surface integral equation solver. The MLMC achieves a higher efficiency by “balancing” the statistical errors due to sampling of the random domain and the numerical errors due to discretization of the geometry at each of these samples. Error balancing results in a smaller number of samples requiring coarser discretizations. Consequently, total execution time is significantly shortened.

  8. Computation of Electromagnetic Fields Scattered From Dielectric Objects of Uncertain Shapes Using MLMC Center for Uncertainty

    KAUST Repository

    Litvinenko, Alexander

    2015-01-05

    Simulators capable of computing scattered fields from objects of uncertain shapes are highly useful in electromagnetics and photonics, where device designs are typically subject to fabrication tolerances. Knowledge of statistical variations in scattered fields is useful in ensuring error-free functioning of devices. Oftentimes such simulators use a Monte Carlo (MC) scheme to sample the random domain, where the variables parameterize the uncertainties in the geometry. At each sample, which corresponds to a realization of the geometry, a deterministic electromagnetic solver is executed to compute the scattered fields. However, to obtain accurate statistics of the scattered fields, the number of MC samples has to be large. This significantly increases the total execution time. In this work, to address this challenge, the Multilevel MC (MLMC) scheme is used together with a (deterministic) surface integral equation solver. The MLMC achieves a higher efficiency by “balancing” the statistical errors due to sampling of the random domain and the numerical errors due to discretization of the geometry at each of these samples. Error balancing results in a smaller number of samples requiring coarser discretizations. Consequently, total execution time is significantly shortened.

  9. Computation of Electromagnetic Fields Scattered From Dielectric Objects of Uncertain Shapes Using MLMC

    KAUST Repository

    Litvinenko, Alexander

    2016-01-06

    Simulators capable of computing scattered fields from objects of uncertain shapes are highly useful in electromagnetics and photonics, where device designs are typically subject to fabrication tolerances. Knowledge of statistical variations in scattered fields is useful in ensuring error-free functioning of devices. Oftentimes such simulators use a Monte Carlo (MC) scheme to sample the random domain, where the variables parameterize the uncertainties in the geometry. At each sample, which corresponds to a realization of the geometry, a deterministic electromagnetic solver is executed to compute the scattered fields. However, to obtain accurate statistics of the scattered fields, the number of MC samples has to be large. This significantly increases the total execution time. In this work, to address this challenge, the Multilevel MC (MLMC [1]) scheme is used together with a (deterministic) surface integral equation solver. The MLMC achieves a higher efficiency by balancing the statistical errors due to sampling of the random domain and the numerical errors due to discretization of the geometry at each of these samples. Error balancing results in a smaller number of samples requiring coarser discretizations. Consequently, total execution time is significantly shortened.

  10. An FMM-FFT accelerated integral equation solver for characterizing electromagnetic wave propagation in mine tunnels and galleries loaded with conductors

    KAUST Repository

    Yücel, Abdulkadir C.

    2014-07-01

    Reliable wireless communication and tracking systems in underground mines are of paramount importance to increase miners\\' productivity while monitoring the environmental conditions and increasing the effectiveness of rescue operations. Key to the design and optimization of such systems are electromagnetic (EM) simulation tools capable of analyzing wave propagation in electromagnetically large mine tunnels and galleries loaded with conducting cables (power, telephone) and mining equipment (trolleys, rails, carts), and potentially partially obstructed by debris from a cave-in. Current tools for simulating EM propagation in mine environments leverage (multi-) modal decompositions (Emslie et. al., IEEE Trans. Antennas Propag., 23, 192-205, 1975; Sun and Akyildiz, IEEE Trans. Commun., 58, 1758-1768, 2010), ray-tracing techniques (Zhang, IEEE Tran. Vehic. Tech., 5, 1308-1314, 2003), or full wave methods. Modal approaches and ray-tracing techniques cannot accurately account for the presence of conductors, intricate details of transmitters/receivers, wall roughness, or unstructured debris from a cave-in. Classical full-wave methods do not suffer from such restrictions. However, they require prohibitively large computational resources when applied to the analysis of electromagnetically large tunnels loaded with conductors. Recently, an efficient hybrid method of moment and transmission line solver has been developed to analyze the EM wave propagation inside tunnels loaded with conductors (Brocker et. al., in Proc IEEE AP-S Symp, pp.1,2, 2012). However, the applicability of the solver is limited to the characterization of EM wave propagation at medium frequency band.

  11. Imaginary-Time Matrix Product State Impurity Solver for Dynamical Mean-Field Theory

    Directory of Open Access Journals (Sweden)

    F. Alexander Wolf

    2015-11-01

    Full Text Available We present a new impurity solver for dynamical mean-field theory based on imaginary-time evolution of matrix product states. This converges the self-consistency loop on the imaginary-frequency axis and obtains real-frequency information in a final real-time evolution. Relative to computations on the real-frequency axis, required bath sizes are much smaller and no entanglement is generated, so much larger systems can be studied. The power of the method is demonstrated by solutions of a three-band model in the single- and two-site dynamical mean-field approximation. Technical issues are discussed, including details of the method, efficiency as compared to other matrix-product-state-based impurity solvers, bath construction and its relation to real-frequency computations and the analytic continuation problem of quantum Monte Carlo methods, the choice of basis in dynamical cluster approximation, and perspectives for off-diagonal hybridization functions.

  12. Electromagnetic field patterning or crystal light

    Science.gov (United States)

    Słupski, Piotr; Wymysłowski, Artur; Czarczyński, Wojciech

    2016-12-01

    Using the orbital angular momentum of light for the development of a vortex interferometer, the underlying physics requires microwave/RF models,1 as well as quantum mechanics for light1, 2 and fluid flow for semiconductor devices.3, 4 The combination of the aforementioned physical models yields simulations and results such as optical lattices,1 or an Inverse Farday effect.5 The latter is explained as the absorption of optical angular momentum, generating extremely high instantenous magnetic fields due to radiation friction. An algorithmic reduction across the computational methods used in microwaves, lasers, quantum optics and holography is performed in order to explain electromagnetic field interactions in a single computational framework. This work presents a computational model for photon-electron interactions, being a simplified gauge theory described using differentials or disturbances (photons) instead of integrals or fields. The model is based on treating the Z-axis variables as a Laplace fluid with spatial harmonics, and the XY plane as Maxwell's equations on boundaries. The result is a unified, coherent, graphical computational method of describing the photon qualitatively, quantitatively and with proportion. The model relies on five variables and is described using two equations, which use emitted power, cavity wavelength, input frequency, phase and time. Phase is treated as a rotated physical dimension under gauge theory of Feynmann's QED. In essence, this model allows the electromagnetic field to be treated with it's specific crystallography. The model itself is described in Python programming language. PACS 42.50.Pq, 31.30.J-, 03.70.+k, 11.10.-z, 67.10.Hk

  13. Note on Inverse Bremsstrahlung in a Strong Electromagnetic Field

    Science.gov (United States)

    Bethe, H. A.

    1972-09-01

    The collisional energy loss of an electron undergoing forced oscillation in an electromagnetic field behaves quite differently in the low and high intensity limits. ... It is shown that in the case of an electromagnetic field v {sub o} >> v {sub t} the rate of transfer is much slower, and actually decreases with the strength of the field.

  14. The classical theory of fields electromagnetism

    CERN Document Server

    Helrich, Carl S

    2012-01-01

    The study of classical electromagnetic fields is an adventure. The theory is complete mathematically and we are able to present it as an example of classical Newtonian experimental and mathematical philosophy. There is a set of foundational experiments, on which most of the theory is constructed. And then there is the bold theoretical proposal of a field-field interaction from James Clerk Maxwell. This textbook presents the theory of classical fields as a mathematical structure based solidly on laboratory experiments. Here the student is introduced to the beauty of classical field theory as a gem of theoretical physics. To keep the discussion fluid, the history is placed in a beginning chapter and some of the mathematical proofs in the appendices. Chapters on Green’s Functions and Laplace’s Equation and a discussion of Faraday’s Experiment further deepen the understanding. The chapter on Einstein’s relativity is an integral necessity to the text. Finally, chapters on particle motion and waves in a dis...

  15. Plant Responses to High Frequency Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    Alain Vian

    2016-01-01

    Full Text Available High frequency nonionizing electromagnetic fields (HF-EMF that are increasingly present in the environment constitute a genuine environmental stimulus able to evoke specific responses in plants that share many similarities with those observed after a stressful treatment. Plants constitute an outstanding model to study such interactions since their architecture (high surface area to volume ratio optimizes their interaction with the environment. In the present review, after identifying the main exposure devices (transverse and gigahertz electromagnetic cells, wave guide, and mode stirred reverberating chamber and general physics laws that govern EMF interactions with plants, we illustrate some of the observed responses after exposure to HF-EMF at the cellular, molecular, and whole plant scale. Indeed, numerous metabolic activities (reactive oxygen species metabolism, α- and β-amylase, Krebs cycle, pentose phosphate pathway, chlorophyll content, terpene emission, etc. are modified, gene expression altered (calmodulin, calcium-dependent protein kinase, and proteinase inhibitor, and growth reduced (stem elongation and dry weight after low power (i.e., nonthermal HF-EMF exposure. These changes occur not only in the tissues directly exposed but also systemically in distant tissues. While the long-term impact of these metabolic changes remains largely unknown, we propose to consider nonionizing HF-EMF radiation as a noninjurious, genuine environmental factor that readily evokes changes in plant metabolism.

  16. Plant Responses to High Frequency Electromagnetic Fields

    Science.gov (United States)

    Vian, Alain; Davies, Eric; Gendraud, Michel; Bonnet, Pierre

    2016-01-01

    High frequency nonionizing electromagnetic fields (HF-EMF) that are increasingly present in the environment constitute a genuine environmental stimulus able to evoke specific responses in plants that share many similarities with those observed after a stressful treatment. Plants constitute an outstanding model to study such interactions since their architecture (high surface area to volume ratio) optimizes their interaction with the environment. In the present review, after identifying the main exposure devices (transverse and gigahertz electromagnetic cells, wave guide, and mode stirred reverberating chamber) and general physics laws that govern EMF interactions with plants, we illustrate some of the observed responses after exposure to HF-EMF at the cellular, molecular, and whole plant scale. Indeed, numerous metabolic activities (reactive oxygen species metabolism, α- and β-amylase, Krebs cycle, pentose phosphate pathway, chlorophyll content, terpene emission, etc.) are modified, gene expression altered (calmodulin, calcium-dependent protein kinase, and proteinase inhibitor), and growth reduced (stem elongation and dry weight) after low power (i.e., nonthermal) HF-EMF exposure. These changes occur not only in the tissues directly exposed but also systemically in distant tissues. While the long-term impact of these metabolic changes remains largely unknown, we propose to consider nonionizing HF-EMF radiation as a noninjurious, genuine environmental factor that readily evokes changes in plant metabolism. PMID:26981524

  17. Three-dimensional parallel edge-based finite element modeling of electromagnetic data with field redatuming

    DEFF Research Database (Denmark)

    Cai, Hongzhu; Čuma, Martin; Zhdanov, Michael

    2015-01-01

    This paper presents a parallelized version of the edge-based finite element method with a novel post-processing approach for numerical modeling of an electromagnetic field in complex media. The method uses an unstructured tetrahedral mesh which can reduce the number of degrees of freedom signific...... seafloor bathymetry. The numerical study demonstrates that the modeling algorithm is capable of simulating the complex topography and bathymetry that is commonly encountered in controlled source electromagnetic problems.......This paper presents a parallelized version of the edge-based finite element method with a novel post-processing approach for numerical modeling of an electromagnetic field in complex media. The method uses an unstructured tetrahedral mesh which can reduce the number of degrees of freedom...... significantly. The linear system of finite element equations is solved using parallel direct solvers which are robust for ill-conditioned systems and efficient for multiple source electromagnetic (EM) modeling. We also introduce a novel approach to compute the scalar components of the electric field from...

  18. The electromagnetic field equations for moving media

    Science.gov (United States)

    Ivezić, T.

    2017-05-01

    In this paper a formulation of the field equation for moving media is developed by the generalization of an axiomatic geometric formulation of the electromagnetism in vacuum (Ivezić T 2005 Found. Phys. Lett. 18 401). First, the field equations with bivectors F (x) and ℳ(x) are presented and then these equations are written with the 4D vectors E(x), B(x), P (x) and M(x). The latter contain both the 4D velocity vector u of a moving medium and the 4D velocity vector v of the observers who measure E and B fields. They do not appear in previous literature. All these equations are also written in the standard basis and compared with Maxwell’s equations with 3D vectors. In this approach the Ampère-Maxwell law and Gauss’s law are inseparably connected in one law and the same happens with Faraday’s law and the law that expresses the absence of magnetic charge. It is shown that Maxwell’s equations with 3D vectors and the field equations with 4D geometric quantities are not equivalent in 4D spacetime

  19. Electromagnetic field interference and cardiac pacemakers.

    Science.gov (United States)

    Jones, S L

    1976-09-01

    The physical and physiological effects of electromagnetic field interference on 440 patients with cardiac pacemakers were determined by reviewing the literature from 1949 to 1973. The sources, mechanisms, and findings of physiological dysfunction and ventricular fibrillation in patients with pacemakers are presented. Shortwave and microwave diathermy and electrical stimulators have been found to have a definite adverse influence on some cardiac pacemakers. The effect of interference may be an increase or decrease in pacemaker rate or rhythm, ventricular fibrillation, a total loss of pacing, or cessation of impulses. Because all pacemaker units are not resistant to interference, no ungrounded electrical equipment and no equipment such as microwave diathermy, short wave diathermy, and electrical stimulators should be placed on, or near, a patient with a cardiac pacemaker.

  20. SPaCe-GEM: solver of the Einstein equations using GPUs under the gravitoelectromagnetic approximation

    Science.gov (United States)

    Gomes, M.; Costa, J. C.; Alves, R. A.; Silva, N. A.; Guerreiro, A.

    2017-08-01

    Under specific conditions, there is a formal analogy between the fundamental equations of electromagnetism and relativistic gravitation, described by the Einstein field equations of general relativity. In this paper, we report on how we have used this analogy to implement a solver of the Einstein equations adapting algorithms initially developed for electromagnetism, combined with methods of heterogeneous supercomputing, in GPU that can achieve fast computing and exhibit good performance. We also present the results of the simulations used to validate our solver.

  1. Cluster solver for dynamical mean-field theory with linear scaling in inverse temperature

    Science.gov (United States)

    Khatami, E.; Lee, C. R.; Bai, Z. J.; Scalettar, R. T.; Jarrell, M.

    2010-05-01

    Dynamical mean-field theory and its cluster extensions provide a very useful approach for examining phase transitions in model Hamiltonians and, in combination with electronic structure theory, constitute powerful methods to treat strongly correlated materials. The key advantage to the technique is that, unlike competing real-space methods, the sign problem is well controlled in the Hirsch-Fye (HF) quantum Monte Carlo used as an exact cluster solver. However, an important computational bottleneck remains; the HF method scales as the cube of the inverse temperature, β . This often makes simulations at low temperatures extremely challenging. We present here a method based on determinant quantum Monte Carlo which scales linearly in β , with a quadratic term that comes in to play for the number of time slices larger than hundred, and demonstrate that the sign problem is identical to HF.

  2. New foundations for applied electromagnetics the spatial structure of fields

    CERN Document Server

    Mikki, Said

    2016-01-01

    This comprehensive new resource focuses on applied electromagnetics and takes readers beyond the conventional theory with the use of contemporary mathematics to improve the practical use of electromagnetics in emerging areas of field communications, wireless power transfer, metamaterials, MIMO and direction-of-arrival systems. The book explores the existing and novel theories and principles of electromagnetics in order to help engineers analyze and design devices for todays applications in wireless power transfers, NFC, and metamaterials.

  3. Evaluation of carcinogenic effects of electromagnetic fields (EMF).

    Science.gov (United States)

    Bayazit, Vahdettin; Bayram, Banu; Pala, Zeydin; Atan, Ozkan

    2010-08-01

    The purpose of this study was to investigate the carcinogenic effects of electromagnetic fields on human. There are many effects of electromagnetic fields on human such as cancer, epidemiology, acute and chronic effects. These effects vary according to the field strength and environmental conditions. There have been many instances of harmful effects of electromagnetic fields from such seemingly innocuous devices as mobile phones, computers, power lines and domestic wiring. The balance of epidemiologic evidence indicates that mobile phone use of less than 10 years does not pose any increased risk of brain tumour or acoustic neuroma. For long-term use, data are sparse, and the following conclusions are therefore uncertain and tentative.

  4. [Dynamics of biomacromolecules in coherent electromagnetic radiation field].

    Science.gov (United States)

    Leshcheniuk, N S; Apanasevich, E E; Tereshenkov, V I

    2014-01-01

    It is shown that induced oscillations and periodic displacements of the equilibrium positions occur in biomacromolecules in the absence of electromagnetic radiation absorption, due to modulation of interaction potential between atoms and groups of atoms forming the non-valence bonds in macromolecules by the external electromagnetic field. Such "hyperoscillation" state causes inevitably the changes in biochemical properties of macromolecules and conformational transformation times.

  5. The plane wave spectrum representation of electromagnetic fields

    CERN Document Server

    Clemmow, P C

    1966-01-01

    The Plane Wave Spectrum Representation of Electromagnetic Fields presents the theory of the electromagnetic field with emphasis to the plane wave. This book explains how fundamental electromagnetic fields can be represented by the superstition of plane waves traveling in different directions. Organized into two parts encompassing eight chapters, this book starts with an overview of the methods whereby plane wave spectrum representation can be used in attacking different characteristic problems belonging to the theories of radiation, diffraction, and propagation. This book then discusses the co

  6. Integrated field equations methods for the computation of electromagnetic fields in strongly inhomogeneous media

    NARCIS (Netherlands)

    Jorna, P.

    2005-01-01

    Electromagnetic field theory plays a very important role in present-day technology; examples of technologies based on electromagnetism that are inextricably bound up with every day life are: radar, remote sensing, geoelectromagnetics, bioelectromagnetics, antennas, wireless communication, optics,

  7. Schwinger mechanism in electromagnetic field in de Sitter spacetime

    Science.gov (United States)

    Bavarsad, Ehsan; Pyo Kim, Sang; Stahl, Clément; Xue, She-Sheng

    2018-01-01

    We investigate Schwinger scalar pair production in a constant electromagnetic field in de Sitter (dS) spacetime. We obtain the pair production rate, which agrees with the Hawking radiation in the limit of zero electric field in dS. The result describes how a cosmic magnetic field affects the pair production rate. In addition, using a numerical method we study the effect of the magnetic field on the induced current. We find that in the strong electromagnetic field the current has a linear response to the electric and magnetic fields, while in the infrared regime, is inversely proportional to the electric field and leads to infrared hyperconductivity.

  8. Electromagnetic field simulation and crack analysis of electromagnetic forming of Magnesium alloy tube

    OpenAIRE

    Wang, Z. F.; Piao, F. X.; Wang, Z.Y.; Cui, J.Z.; Ma, M. X.

    2011-01-01

    The AZ31 magnesium alloy tube was used for electromagnetic forming experiment of three kinds of input voltages. The stress-strain state of tube forming was analyzed. It was shown that the cause of oblique crack of tube was σr of axial inhomogeneous distribution and σz, and the cause of longitudinal crack was σr and σè of inhomogeneous distribution in circumferential direction. Moreover, the electromagnetic field and force field during electromagnetic forming was simulated by ANSYS software. T...

  9. 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.

  10. 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.

  11. 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...

  12. Impact of electromagnetic field on the pathogenicity of selected ...

    African Journals Online (AJOL)

    Rhipicephalus decoloratus) to variable intensities of electromagnetic field for different periods of time was examined on their pathogenicity on tick. Some bacterial isolates from the macerate of tick cadavers were used in the infection of healthy engorged ...

  13. High dynamic range electric field sensor for electromagnetic pulse detection

    National Research Council Canada - National Science Library

    Lin, Che-Yun; Wang, Alan X; Lee, Beom Suk; Zhang, Xingyu; Chen, Ray T

    2011-01-01

    ...) polymer Y-fed directional coupler for electromagnetic wave detection. This electrode-less, all optical, wideband electrical field sensor is fabricated using standard processing for E-O polymer photonic devices...

  14. Influence of electromagnetic field on pure metals and alloys structure

    OpenAIRE

    J. Szajnar; M. Stawarz; T. Wróbel; W. Sebzda

    2009-01-01

    Purpose: The first aim of investigations was the reduction of grain size and unification of structure for pure Al casting by introduction of small amount of inoculant (less than obligatory standard PN-EN 573-3, which concerning about aluminium purity) and with electromagnetic field. The second aim was to determination of electromagnetic field influence on morphology of graphite in cast iron ingots, which were poured with variable founding parameters.Design/methodology/approach: To investigati...

  15. Effects of Electromagnetic Fields on Fish and Invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Irvin R.; Woodruff, Dana L.; Marshall, Kathryn E.; Pratt, William J.; Roesijadi, Guritno

    2010-10-13

    In this progress report, we describe the preliminary experiments conducted with three fish and one invertebrate species to determine the effects of exposure to electromagnetic fields. During fiscal year 2010, experiments were conducted with coho salmon (Onchrohychus kisutch), California halibut (Paralicthys californicus), Atlantic halibut (Hippoglossus hippoglossus), and Dungeness crab (Cancer magister). The work described supports Task 2.1.3: Effects on Aquatic Organisms, Subtask 2.1.3.1: Electromagnetic Fields.

  16. A linear in β solver for Cluster Dynamical Mean Field Theory

    Science.gov (United States)

    Khatami, Ehsan; Jarrell, Mark; Lee, Che-Rung; Scalettar, Richard

    2009-03-01

    We develop a Quantum Monte Carlo (QMC) cluster solver for the Dynamical Cluster Approximation (DCA) which scales linearly in the inverse temperature, β, and has the same minus sign problem as conventional methods. Determinantal QMC (DQMC) used in this method is modified by adding non-interacting bands to mimic the coupling to the host. The DCA hybridization function is fitted to the non-interacting band parameters. We prove that the sign problem has the same statistics as in the Hirsch-Fye (HF) algorithm in the limit of a large number of bath bands (Nα). Whereas the HFQMC scales as 3̂, this DQMC-based method scales linearly in β. We demonstrate rapid convergence of the sign to the HF result for different cluster sizes and model parameters as Nα increases. We also present results for the convergence of other physical quantities to their HFQMC counterparts. This method can be used to solve other embedded cluster problems including those in Dynamical Mean Field Theory (DMFT), and cellular DMFT.

  17. The power and beauty of electromagnetic fields

    CERN Document Server

    Morgenthaler, Frederic R

    2011-01-01

    Unique, multi-level textbook is adaptable to introductory, intermediate, and advanced levels This revolutionary textbook takes a unique approach to electromagnetic theory, comparing both conventional and modern theories. It explores both the Maxwell-Poynting representation as well as the Alternate representation, which the author demonstrates is generally simpler and more suitable for analyzing modern electromagnetic environments. Throughout the text, students and researchers have the opportunity to examine both of these theories and discover how each one can be applied to solve problems.

  18. [The influence of electromagnetic fields on flora and fauna].

    Science.gov (United States)

    Rochalska, Małgorzata

    2009-01-01

    This paper presents the influence of natural and artificial electromagnetic fields (EMF) on fauna and flora. The mechanisms of Earth's magnetic field detection and the use of this skill by migratory animals to faultlessly reach the destination of their travel are discussed, as well as the positive effects of electric and magnetic fields on plants relative to their physiology, yielding and health. EMF influence on social insects and animal organisms, including possible DNA damages and DNA repair systems, is presented. The influence of high frequency electromagnetic fields on birds nesting is also discussed.

  19. Study of Electromagnetic Fields on Cellular Systems Study of Electromagnetic Fields on Cellular Systems

    Directory of Open Access Journals (Sweden)

    Sergio Solorio-Meza

    2012-02-01

    Full Text Available Durante las últimas décadas, el interés por explicar el efecto de la radiación no ionizante, como es el caso de los campos electromagnéticos (CEM sobre sistemas celulares ha aumentado considerablemente. En este artículo se describe la interacción que existe entre los CEM y sistemas biológicos. Se discute el efecto de la estimulación electromagnética a diferentes frecuencias e intensidades en cultivos celulares. Resultados preliminares al estimular células de neuroblastomas SK-NSH con campos electromagnéticos de extra baja frecuencia (CEM-EBF, CEM que van del rango de 3 a 30 Hz, indican que se induce un estrés celularque se refleja en variaciones en la expresión de proteínas respecto al grupo de células no estimuladas. En particular, la expresión de las proteínas muestra que los CEM-EBF producen cambios en las proteínas presentes en condiciones normales o basales en las células, es decir, aparecen nuevas proteínas o existe un aumento en la cantidad de ellas.In the last decades the interest to study the effect of non-ionizing radiation, such as the electromagnetic fields (EMF on cellular systems has increased. In this article the interaction between EMF and biological systems is described. An analysis of the effect of the electromagnetic stimulation at different frequencies and intensities on cell cultures is performed. Preliminary results show that the stimulation with extremely low frequency electromagnetic fields (ELF-EMF, EMF from 3 to 30 Hz, on the cellular line of neuroblastomaSK-NSH induces cellular stress. This is reflected by a variation in the proteins expression in comparison with the group of cells no stimulated. In particular, the proteins expression shows that the ELF-EMF produce changes in the current proteins in normal or basal conditionsin the cells, that is, new proteins appear or there is evidence of an increasing in theamount of them.

  20. Suppression and control of leakage field in electromagnetic helical microwiggler

    Energy Technology Data Exchange (ETDEWEB)

    Ohigashi, N. [Kansai Univ., Osaka (Japan); Tsunawaki, Y. [Osaka Sangyo Univ. (Japan); Imasaki, K. [Institute for Laser Technology, Osaka (Japan)] [and others

    1995-12-31

    Shortening the period of electromagnetic wiggler introduces both the radical increase of the leakage field and the decrease of the field in the gap region. The leakage field is severer problem in planar electromagnetic wiggler than in helical wiggler. Hence, in order to develop a short period electromagnetic wiggler, we have adopted {open_quotes}three poles per period{close_quotes} type electromagnetic helical microwiggler. In this work, we inserted the permanent magnet (PM) blocks with specific magnetized directions in the space between magnetic poles, for suppressing the leakage field flowing out from a pole face to the neighboring pole face. These PM-blocks must have higher intrinsic coersive force than saturation field of pole material. The gap field due to each pole is adjustable by controlling the leakage fields, that is, controlling the position of each iron screw set in each retainer fixing the PM-blocks. At present time, a test wiggler with period 7.8mm, periodical number 10 and gap length 4.6mm has been manufactured. Because the ratio of PM-block aperture to gap length is important parameter to suppress the leakage field, the parameter has been surveyed experimentally for PM-blocks with several dimensions of aperture. The field strength of 3-5kG (K=0.2-0.4) would be expected in the wiggler.

  1. Magnetic fields, special relativity and potential theory elementary electromagnetic theory

    CERN Document Server

    Chirgwin, B H; Kilmister, C W

    1972-01-01

    Magnetic Fields, Special Relativity and Potential Theory is an introduction to electromagnetism, special relativity, and potential theory, with emphasis on the magnetic field of steady currents (magnetostatics). Topics covered range from the origin of the magnetic field and the magnetostatic scalar potential to magnetization, electromagnetic induction and magnetic energy, and the displacement current and Maxwell's equations. This volume is comprised of five chapters and begins with an overview of magnetostatics, followed by a chapter on the methods of solving potential problems drawn from elec

  2. Reasearch and Evaluation of Electromagnetic Fields of Refrigerators

    Directory of Open Access Journals (Sweden)

    Pranas Baltrėnas

    2013-12-01

    Full Text Available The use of refrigerators causes the occurence of electromagnetic fields that are invisible and intangible, which therefore makes difficulties in protecting ourselves from them. A refrigerator is an irreplaceable item in domestic household and thus can be hardly ignored by a modern way of human life. In order to preserve the characteristics of products, the refrigerator must operate continuously (24 hrs a day, regardless of the time of the year. This results in a huge increase in electricity consumption, which leads to energy consumption related pollution of the environment emitting CO2 gas. On these grounds, it is necessary to assess electromagnetic fields created by the refrigerator. Studies on electromagnetic fields produced by refrigerators were conducted in domestic premises where people spent a significant part of the day. For comparison purposes, five different power refrigerators were chosen (1 – 0.20 kW; 2 – 0.25 kW; 3 – 0.30 kW; 4 – 0.35 kW; 5 – 0.40 kW. The obtained results, according to the parameters of their electromagnetic fields, were presented in graphs and charts and showed that the values of electric and magnetic intensity of refrigerators depended on the distance and the power of the refrigerator. The conducted research also disclosed that none of tested refrigerators exceeded the permissible limits of electromagnetic fields.Article in Lithuanian

  3. Generalized-ray theory for electromagnetic fields in layered media

    NARCIS (Netherlands)

    Štumpf, M.; De Hoop, A.T.; Vandenbosch, G.A.E.

    2013-01-01

    Generalized-ray theory for time-domain electromagnetic fields in a horizontally layered medium is developed. After introducing appropriate integral transformations and source-type field representations in vertically inhomogeneous media, the solution is written out in terms of generalized ray

  4. Pregnancy and electromagnetic fields; Grossesse et champs electromagnetiques

    Energy Technology Data Exchange (ETDEWEB)

    Bisseriex, Ch. [CARSAT Auvergne (France); Laurent, P. [Caisse d' Assurance Retraite et de la Sante au Travail - CARSAT Centre-Ouest (France); Cabaret, Ph. [CARSAT Languedoc-Roussillon (France); Bonnet, C. [CARSAT Centre (France); Marteau, E. [CRAM ile-de-France (France); Le Berre, G. [CARSAT Bretagne (France); Tirlemont, S. [CARSAT Nord-Picardie (France); Castro, H. [CARSAT Midi-Pyrenees (France); Becker, A.; Demaret, Ph.; Donati, M. [INRS Lorraine (France); Ganem, Y.; Moureaux, P. [INRS Paris (France)

    2011-07-15

    This document briefly indicates the status of knowledge regarding the effect of magnetic fields on biological tissues and pregnancy, outlines the lack of data on some frequencies and the weakness of studies on long term effects on child development. It evokes the issue of exposure assessment and that of identification of workstations exposed to electromagnetic fields

  5. Cytological effects of pulsed electromagnetic fields and static ...

    African Journals Online (AJOL)

    Cytological effects of pulsed electromagnetic fields and static magnetic fields induced by a therapeutic device on in vivo exposed rats. ... were distributed into three groups: (a) 5 males and 5 females (independently) exposed to PEMFs combined with SMFs, (b) animals treated with SMFs only, and (c) non-exposed animals.

  6. Health Effects of Electromagnetic Fields: A Review of Literature.

    Science.gov (United States)

    White, George L.; And Others

    1995-01-01

    Current evidence suggests that the effects of electromagnetic fields (EMF) disturb cell homeostasis at very low intensities by influencing discrete intracellular magnetic fields. The article reviews current research about the health effects of EMF, examining historical implications, childhood studies, adult studies, and popular press reports, and…

  7. Biological effects of electromagnetic fields and recently updated safety guidelines for strong static magnetic fields.

    Science.gov (United States)

    Yamaguchi-Sekino, Sachiko; Sekino, Masaki; Ueno, Shoogo

    2011-01-01

    Humans are exposed daily to artificial and naturally occurring magnetic fields that originate from many different sources. We review recent studies that examine the biological effects of and medical applications involving electromagnetic fields, review the properties of static and pulsed electromagnetic fields that affect biological systems, describe the use of a pulsed electromagnetic field in combination with an anticancer agent as an example of a medical application that incorporates an electromagnetic field, and discuss the recently updated safety guidelines for static electromagnetic fields. The most notable modifications to the 2009 International Commission on Non-Ionizing Radiation Protection guidelines are the increased exposure limits, especially for those who work with or near electromagnetic fields (occupational exposure limits). The recommended increases in exposure were determined using recent scientific evidence obtained from animal and human studies. Several studies since the 1994 publication of the guidelines have examined the effects on humans after exposure to high static electromagnetic fields (up to 9.4 tesla), but additional research is needed to ascertain further the safety of strong electromagnetic fields.

  8. How can the neutrino interact with the electromagnetic field?

    Science.gov (United States)

    Novello, M.; Ducap, C. E. L.

    2018-01-01

    Maxwell electrodynamics in the fixed Minkowski space-time background can be described in an equivalent way in a curved Riemannian geometry that depends on the electromagnetic field and that we call the electromagnetic metric (e-metric for short). After showing such geometric equivalence we investigate the possibility that new processes dependent on the e-metric are allowed. In particular, for very high values of the field, a direct coupling of uncharged particles to the electromagnetic field may appear. Supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), FAPERJ (Fundação do Amparo Pesquisa do Rio de Janeiro, FINEP (Financiadora de Estudos e Projetos) and Coordenação do Aperfeiçoamento do Pessoal do Ensino Superior (CAPES)

  9. The electromagnetic bio-field: clinical experiments and interferences.

    Science.gov (United States)

    Burnei, G; Hodorogea, D; Georgescu, I; Gavriliu, Ş; Drăghici, I; Dan, D; Vlad, C; Drăghici, L

    2012-06-12

    One of the most important factors is the technical and scientifically rapid development that is continually modifying the world we live in and polluting it with electromagnetic radiations. A functional and structural influence of magnetic and electromagnetic field on living organisms is presented in the literature by many performed experiments. The notion of bio-field represents the electromagnetic field generated by the bio-structures, not only in their normal physiological activities but also in their pathological states. There is a tight interdependency between the bio-field and the bio-structure, which respects the primary notion of an electromagnetic field given by the Maxwell-Faraday laws, in which, the electromagnetic phenomena are simplified to the field variations. These variations can be expressed in a coherent differential equation system that bounds the field vectors to different space points at different time moments. The living organisms cannot contain electrostatic and magneto-static fields due to the intense activity of the bio-structures. The biochemical reactions that have high rhythms and speeds always impose the electrodynamics character of the biologic field that also corresponds to the stability of the protein molecule that can be explained only through a dynamic way. The existent energy is not considered an exciting agent, and it does not lead to any effects. The parameters of these elementary bio-fields cannot yet be fully known due to technical reasons. The biological structures are very complex ones and undergo continuous dynamical activity. That is why the calculus model should be related to the constant dynamics, nowadays being very difficult to express.

  10. Calculation of the Electromagnetic Field Around a Microtubule

    Directory of Open Access Journals (Sweden)

    D. Havelka

    2009-01-01

    Full Text Available Microtubules are important structures in the cytoskeleton which organizes the cell. A single microtubule is composed of electrically polar structures, tubulin heterodimers, which have a strong electric dipole moment. Vibrations are expected to be generated in microtubules, thus tubulin heterodimers oscillate as electric dipoles. This gives rise to an electromagnetic field which is detected around the cells. We calculate here the electromagnetic field of microtubules if they are excited at 1 GHz. This paper includes work done for the bachelor thesis of the first author. 

  11. Nonlinear properties of gated graphene in a strong electromagnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Avetisyan, A. A., E-mail: artakav@ysu.am; Djotyan, A. P., E-mail: adjotyan@ysu.am [Yerevan State University, Department of Physics (Armenia); Moulopoulos, K., E-mail: cos@ucy.ac.cy [University of Cyprus, Department of Physics (Cyprus)

    2017-03-15

    We develop a microscopic theory of a strong electromagnetic field interaction with gated bilayer graphene. Quantum kinetic equations for density matrix are obtained using a tight binding approach within second quantized Hamiltonian in an intense laser field. We show that adiabatically changing the gate potentials with time may produce (at resonant photon energy) a full inversion of the electron population with high density between valence and conduction bands. In the linear regime, excitonic absorption of an electromagnetic radiation in a graphene monolayer with opened energy gap is also studied.

  12. Large Eddy Simulations of Double-Ruler Electromagnetic Field Effect on Transient Flow During Continuous Casting

    Science.gov (United States)

    Singh, Ramnik; Thomas, Brian G.; Vanka, Surya P.

    2014-06-01

    Transient flow during nominally steady conditions is responsible for many intermittent defects during the continuous casting of steel. The double-ruler electromagnetic field configuration, or "FC-Mold EMBr," is popular in commercial slab casting as it provides independent control of the applied static field near the jet and free surface regions of the mold. In the current study, transient flow in a typical commercial caster is simulated in the absence and in the presence of a double-ruler magnetic field, with rulers of equal strengths. Large eddy simulations with the in-house code CU-FLOW resolve the important transient behavior, using grids of over five million cells with a fast parallel solver. In the absence of a magnetic field, a double-roll pattern is observed, with transient unbalanced behavior, high surface velocities (~0.5 m/s), surface vortex formation, and very large surface-level fluctuations (~±12 mm). Applying the magnetic field suppresses the unbalanced behavior, producing a more complex mold flow pattern, but with much lower surface velocities (~0.1 m/s), and a flat surface level with small level fluctuations (<±1 mm). Nail board measurements taken at this commercial caster, in the absence of the field, matched reasonably well with the calculated results, both quantitatively and qualitatively.

  13. Occupational exposure to electromagnetic fields in the Polish Armed Forces

    Directory of Open Access Journals (Sweden)

    Jarosław Kieliszek

    2017-08-01

    Full Text Available Objectives: Standard devices used by military personnel that may pose electromagnetic hazard include: radars, missile systems, radio navigation systems and radio transceivers. The aim of this study has been to evaluate the exposure of military personnel to electromagnetic fields. Material and Methods: Occupational exposure to electromagnetic fields was analyzed in the work environment of personnel of 204 devices divided into 5 groups (surface-to-air missile system radars, aircraft and helicopters, communication devices, surveillance and height finder radars, airport radars and radio navigation systems. Measurements were carried out at indicators, device terminals, radio panels, above vehicle seats, in vehicle hatches, by cabinets containing high power vacuum tubes and other transmitter components, by transmission lines, connectors, etc. Results: Portable radios emit the electric field strength between 20–80 V/m close to a human head. The manpack radio operator’s exposure is 60–120 V/m. Inside vehicles with high frequency/very high frequency (HF/VHF band radios, the electric field strength is between 7–30 V/m and inside the radar cabin it ranges between 9–20 V/m. Most of the personnel on ships are not exposed to the electromagnetic field from their own radar systems but rather by accidental exposure from the radar systems of other ships. Operators of surface-to-air missile systems are exposed to the electric field strength between 7–15 V/m and the personnel of non-directional radio beacons – 100–150 V/m. Conclusions: In 57% of military devices Polish soldiers work in the occupational protection zones. In 35% of cases, soldiers work in intermediate and hazardous zones and in 22% – only in the intermediate zone. In 43% of devices, military personnel are not exposed to electromagnetic field. Int J Occup Med Environ Health 2017;30(4:565–577

  14. Electromagnetic fields and Green functions in elliptical vacuum chambers

    CERN Document Server

    Persichelli, Serena; Migliorati, Mauro; Palumbo, Luigi; Vaccaro, Vittorio; CERN. Geneva. ATS Department

    2017-01-01

    In this paper, we discuss the electromagnetic interaction between a point charge travelling inside a waveguide of elliptical cross section, and the waveguide itself. By using a convenient expansion of the Mathieu functions, useful in particular for treating a variety of problems in applied mathematics and physics with elliptic geometry, we first obtain the longitudinal electromagnetic field of a point charge (Green function) in free space in terms of elliptical coordinates. This expression allows, then, to calculate the scattered field due to the boundary conditions in our geometry. By summing the contribution of the direct or primary field and the indirect field scattered by the boundary, after a careful choice of some expansion expressions, we derive a novel formula of the longitudinal electric field, in any transverse position of the elliptical cross section, generated by the charge moving along the longitudinal axis of the waveguide. The obtained expression is represented in a closed form, it can be diffe...

  15. Uniqueness of time-independent electromagnetic fields

    DEFF Research Database (Denmark)

    Karlsson, Per W.

    1974-01-01

    As a comment on a recent paper by Steele, a more general uniqueness theorem for time-independent fields is mentioned. ©1974 American Institute of Physics......As a comment on a recent paper by Steele, a more general uniqueness theorem for time-independent fields is mentioned. ©1974 American Institute of Physics...

  16. Electromagnetic time reversal focusing of near field waves in metamaterials

    Science.gov (United States)

    Chabalko, Matthew J.; Sample, Alanson P.

    2016-12-01

    Precise control of electromagnetic energy on a deeply subwavelength scale in the near field regime is a fundamentally challenging problem. In this letter we demonstrate the selective focusing of electromagnetic energy via the electromagnetic time reversal in the near field of a metamaterial. Our analysis begins with fundamental mathematics, and then is extended to the experimental realm where focusing in space and time of the magnetic fields in the near field of a 1-Dimensional metamaterial is shown. Under time reversal focusing, peak instantaneous fields at receiver locations are at minimum ˜200% greater than other receivers. We then leverage the strong selective focusing capabilities of the system to show individual and selective powering of light emitting diodes connected to coil receivers placed in the near field of the metamaterial. Our results show the possibility of improving display technologies, near field imaging systems, increasing channel capacity of near field communication systems, and obtaining a greater control of energy delivery in wireless power transfer systems.

  17. Vacuum Polarisation Tensors in Constant Electromagnetic Fields Part III

    CERN Document Server

    Gies, Holger; Gies, Holger; Schubert, Christian

    2001-01-01

    The string-inspired technique is used for a first calculation of the one-loop axialvector vacuum polarisation in a general constant electromagnetic field. A compact result is reached for the difference between this tensor and the corresponding vector vacuum polarisation. This result is confirmed by a Feynman diagram calculation. Its physical relevance is briefly discussed.

  18. Effects of extremely low frequency electromagnetic fields on growth ...

    African Journals Online (AJOL)

    Jane

    2011-08-22

    Aug 22, 2011 ... Electromagnetic fields are an important environmental factor that can influence the growth and development of plants. Exposure to EMFs was performed by a locally designed EMF generator. Our investigations were focused on plants grown from wet pretreated seeds with 3 and 10 mT for a 4 h exposure ...

  19. 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...

  20. Generation of a Desired Three-Dimensional Electromagnetic Field

    DEFF Research Database (Denmark)

    2005-01-01

    The present invention relates to a method and a system for synthesizing a prescribed three-dimensional electromagnetic field based on generalized phase contrast imaging. Such a method and apparatus may be utilized in advanced optical micro and nano-manipulation, such as by provision of a multiple...

  1. Motion of Charged Particles in Electromagnetic Fields and Special ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 7. Motion of Charged Particles in Electromagnetic Fields and Special Theory of Relativity. P Chaitanya Das G Srinivasa Murthy P C Deshmukh K Satish Kumar T A Venkatesh. Classroom Volume 9 Issue 7 July 2004 pp 77-85 ...

  2. Impact of high electromagnetic field levels on childhood leukemia incidence

    NARCIS (Netherlands)

    Teepen, J.C.; Dijck, J.A. van

    2012-01-01

    The increasing exposure to electromagnetic fields (EMFs) has raised concern, as increased exposure may result in an increased risk of childhood leukemia (CL). Besides a short introduction of CL and EMF, our article gives an evaluation of the evidence of a causal relation between EMF and CL by

  3. Effect of Mobile Phone Radiofrequency Electromagnetic Fields on ...

    African Journals Online (AJOL)

    olayemitoyin

    Summary: Since cell phones emit radiofrequency electromagnetic fields (EMFs), this study tested the hypothesis that cell phones placed near the heart may interfere with the electrical rhythm of the heart or affect the blood pressure. Following informed consent, eighteen randomly selected apparently healthy male volunteers ...

  4. Effects of extremely low frequency electromagnetic fields on growth ...

    African Journals Online (AJOL)

    Electromagnetic fields are an important environmental factor that can influence the growth and development of plants. Exposure to EMFs was performed by a locally designed EMF generator. Our investigations were focused on plants grown from wet pretreated seeds with 3 and 10 mT for a 4 h exposure time and compared ...

  5. Electromagnetic Fields and Public Health: Mobile Phones

    Science.gov (United States)

    ... phones Fact sheet N°193 Reviewed October 2014 Key facts Mobile phone use is ubiquitous with an ... the "Guidelines for limiting exposure to time-varying electric, magnetic and electromagetic fields (up to 300 GHz)" , ...

  6. Autoionizing states driven by stochastic electromagnetic fields

    Science.gov (United States)

    Mouloudakis, G.; Lambropoulos, P.

    2018-01-01

    We have examined the profile of an isolated autoionizing resonance driven by a pulse of short duration and moderately strong field. The analysis has been based on stochastic differential equations governing the time evolution of the density matrix under a stochastic field. Having focused our quantitative analysis on the 2{{s}}2{{p}}({}1{{P}}) resonance of helium, we have investigated the role of field fluctuations and of the duration of the pulse. We report surprisingly strong distortion of the profile, even for peak intensity below the strong field limit. Our results demonstrate the intricate connection between intensity and pulse duration, with the latter appearing to be the determining influence, even for a seemingly short pulse of 50 fs. Further effects that would arise under much shorter pulses are discussed.

  7. Design of Electric Field Sensors for Measurement of Electromagnetic Pulse

    Directory of Open Access Journals (Sweden)

    Hui ZHANG

    2014-01-01

    Full Text Available In this paper, a D-dot electric field sensor and a fiber-optic transmission electric field sensor are developed for measurement of electromagnetic pulse. The D-dot sensor is a differential model sensor without source and has a simple structure. The fiber-optic transmission sensor is in the type of small dipole antenna, which uses its outside shielding layer as a pair of antennas. Design of the sensor circuit and the test system are introduced in this paper. A calibration system for these pulsed field sensors is established and the test results verified the ability of the developed sensors for measurement of the standard electromagnetic pulse field (the half peak width is 25 ns and the rising time is 2.5 ns.

  8. A FMM-FFT accelerated hybrid volume surface integral equation solver for electromagnetic analysis of re-entry space vehicles

    KAUST Repository

    Yücel, Abdulkadir C.

    2014-07-01

    Space vehicles that re-enter the atmosphere often experience communication blackout. The blackout occurs when the vehicle becomes engulfed in plasma produced by interactions between the vehicle surface and the atmosphere. The plasma often is concentrated in a relatively thin shell around the vehicle, with higher densities near its nose than rear. A less structured, sometimes turbulent plasma wake often trails the vehicle. The plasma shell severely affects the performance of side-mounted antennas as it alters their characteristics (frequency response, gain patterns, axial ratio, and impedance) away from nominal, free-space values, sometimes entirely shielding the antenna from the outside world. The plasma plume/turbulent wake similarly affect the performance of antennas mounted at the back of the vehicle. The electromagnetic characteristics of the thin plasma shell and plume/turbulent wake heavily depend on the type of re-entry trajectory, the vehicle\\'s speed, angles of attack, and chemical composition, as well as environmental conditions. To analyze the antennas\\' performance during blackout and to design robust communication antennas, efficient and accurate simulation tools for charactering the antennas\\' performance along the trajectory are called for.

  9. A fast-multipole domain decomposition integral equation solver for characterizing electromagnetic wave propagation in mine environments

    KAUST Repository

    Yücel, Abdulkadir C.

    2013-07-01

    Reliable and effective wireless communication and tracking systems in mine environments are key to ensure miners\\' productivity and safety during routine operations and catastrophic events. The design of such systems greatly benefits from simulation tools capable of analyzing electromagnetic (EM) wave propagation in long mine tunnels and large mine galleries. Existing simulation tools for analyzing EM wave propagation in such environments employ modal decompositions (Emslie et. al., IEEE Trans. Antennas Propag., 23, 192-205, 1975), ray-tracing techniques (Zhang, IEEE Tran. Vehic. Tech., 5, 1308-1314, 2003), and full wave methods. Modal approaches and ray-tracing techniques cannot accurately account for the presence of miners and their equipments, as well as wall roughness (especially when the latter is comparable to the wavelength). Full-wave methods do not suffer from such restrictions but require prohibitively large computational resources. To partially alleviate this computational burden, a 2D integral equation-based domain decomposition technique has recently been proposed (Bakir et. al., in Proc. IEEE Int. Symp. APS, 1-2, 8-14 July 2012). © 2013 IEEE.

  10. The study on electromagnetic field of an RFQ

    CERN Document Server

    Ouyang Hua Fu; Luo Zi Hua; Xu Tao Guang; Xu Wen Wu

    2002-01-01

    Computer simulations are carried out for calculating the electromagnetic field distribution and frequency in either 2-D coordinates (by SUPERFISH) or 3-D coordinates (by MAFIA), by which the tuners, the end cells, the coupling cells and other components of the radio-frequency quadrupole (RFQ) are designed. The designing principle is that the E-field longitudinal distribution and the local quadrupole cut-off frequency should be kept as constant as possible

  11. Electromagnetic Field Influence upon the Electroenergetic System of the Ship

    Directory of Open Access Journals (Sweden)

    Gheorghe Samoilescu

    2006-10-01

    Full Text Available It is presented a global evaluation criterion of the perturbation magnetic field of a volume, which presents interest. It is determined the medium volume density of the magnetic field energy in the interested volume and correspond the medium value of the electromotive force (e.m.f. which is induced in a single winding. The medium value of the e.m.f. is considered to be an evaluation criterion of the electromagnetic compatibility.

  12. Electromagnetic radiation by quark-gluon plasma in magnetic field

    OpenAIRE

    Tuchin, Kirill

    2012-01-01

    The electromagnetic radiation by quark-gluon plasma in strong magnetic field is calculated. The contributing processes are synchrotron radiation and one--photon annihilation. It is shown that in relativistic heavy--ion collisions at RHIC and LHC synchrotron radiation dominates over the annihilation. Moreover, it constitutes a significant part of all photons produced by the plasma at low transverse momenta; its magnitude depends on the plasma temperature and the magnetic field strength. Electr...

  13. On Huygens' principle for Dirac operators associated to electromagnetic fields

    Directory of Open Access Journals (Sweden)

    CHALUB FABIO A.C.C.

    2001-01-01

    Full Text Available We study the behavior of massless Dirac particles, i.e., solutions of the Dirac equation with m = 0 in the presence of an electromagnetic field. Our main result (Theorem 1 is that for purely real or imaginary fields any Huygens type (in Hadamard's sense Dirac operators is equivalent to the free Dirac operator, equivalence given by changes of variables and multiplication (right and left by nonzero functions.

  14. Metric Independence of Vacuum and Force-Free Electromagnetic Fields.

    Science.gov (United States)

    Harte, Abraham I

    2017-04-07

    Electromagnetic fields which solve the vacuum Maxwell equations in one spacetime are well known to also be solutions in all spacetimes with conformally related metrics. This provides a sense in which electromagnetism alone cannot be used to measure certain aspects of geometry. We show that there is actually much more which cannot be so measured; relatively little of a spacetime's geometry is in fact imprinted in any particular electromagnetic field. This is demonstrated by finding a much larger class of metric transformations-involving five free functions-which preserve Maxwell solutions both in vacuum, without local currents, and also for the force-free electrodynamics associated with a tenuous plasma. One consequence of this is that many of the exact force-free fields which have previously been found around Schwarzschild and Kerr black holes are also solutions in appropriately identified flat backgrounds. As a more direct application, we use our metric transformations to write down a large class of electromagnetic waves which remain unchanged by a large class of gravitational waves propagating "in the same direction."

  15. Metric Independence of Vacuum and Force-Free Electromagnetic Fields

    Science.gov (United States)

    Harte, Abraham I.

    2017-04-01

    Electromagnetic fields which solve the vacuum Maxwell equations in one spacetime are well known to also be solutions in all spacetimes with conformally related metrics. This provides a sense in which electromagnetism alone cannot be used to measure certain aspects of geometry. We show that there is actually much more which cannot be so measured; relatively little of a spacetime's geometry is in fact imprinted in any particular electromagnetic field. This is demonstrated by finding a much larger class of metric transformations—involving five free functions—which preserve Maxwell solutions both in vacuum, without local currents, and also for the force-free electrodynamics associated with a tenuous plasma. One consequence of this is that many of the exact force-free fields which have previously been found around Schwarzschild and Kerr black holes are also solutions in appropriately identified flat backgrounds. As a more direct application, we use our metric transformations to write down a large class of electromagnetic waves which remain unchanged by a large class of gravitational waves propagating "in the same direction."

  16. The electromagnetic force field, fluid flow field and temperature profiles in levitated metal droplets

    Science.gov (United States)

    El-Kaddah, N.; Szekely, J.

    1982-01-01

    A mathematical representation was developed for the electromagnetic force field, the flow field, the temperature field (and for transport controlled kinetics), in a levitation melted metal droplet. The technique of mutual inductances was employed for the calculation of the electromagnetic force field, while the turbulent Navier - Stokes equations and the turbulent convective transport equations were used to represent the fluid flow field, the temperature field and the concentration field. The governing differential equations, written in spherical coordinates, were solved numerically. The computed results were in good agreement with measurements, regarding the lifting force, and the average temperature of the specimen and carburization rates, which were transport controlled.

  17. Electromagnetic Field Effects in Semiconductor Crystal Growth

    Science.gov (United States)

    Dulikravich, George S.

    1996-01-01

    This proposed two-year research project was to involve development of an analytical model, a numerical algorithm for its integration, and a software for the analysis of a solidification process under the influence of electric and magnetic fields in microgravity. Due to the complexity of the analytical model that was developed and its boundary conditions, only a preliminary version of the numerical algorithm was developed while the development of the software package was not completed.

  18. DATA ACQUISITION AND ANALYSIS OF LOW FREQUENCY ELECTROMAGNETIC FIELD

    Directory of Open Access Journals (Sweden)

    PETRICA POPOV

    2016-06-01

    Full Text Available In recent years more and more studies have shown that, the low frequency field strength (particularly magnetic, 50 / 60Hz are a major risk factor; according to some specialists - even more important as the radiation field. As a result, the personnel serving equipment and facilities such as: electric generators, synchronous, the motors, the inverters or power transformers is subjected continually to intense fields, in their vicinity, with possible harmful effects in the long term by affecting metabolism cell, espectively, the biological mechanisms.Therefore, finding new methods and tools for measurement and analysis of low frequency electromagnetic fields may lead to improved standards for exposure limits of the human body.

  19. [Problems of hygienic standardization of electromagnetic fields produced by teletransmitting objects].

    Science.gov (United States)

    Karachev, I I

    1989-10-01

    Maximum allowable electromagnetic field levels produced by teletransmitting stations and differentiated by frequency have been described. The prospects of further studies on the improvement of hygienic standardization of electromagnetic fields have been set forth.

  20. [Operational aspects of risk perception in the electromagnetic fields exposition].

    Science.gov (United States)

    Pennarola, E; Barletta, R; Quarto, E; Pennarola, R

    2007-01-01

    The increase of electromagnetic fields exposition is being associated with the increase of risk perception in the people exposed due to the uncertainty of the biological and sanitary effects. Research is being carried out on the symptomatology shown by the 45 people living near power-lines in the Benevento area and consequently exposed to electromagnetic fields. The measure of the magnetic and electric field was in the normal range while the people showed most symptoms in the subjective and behavioural sphere. The research findings suggest that risk assessement should take into account the subjectivity of the people exposed as shown in the special questionnaires with the aim of reducing the subjective and behavioural symptomatology for developing a new environmental medicine.

  1. Exposure to high-frequency transient electromagnetic fields.

    Science.gov (United States)

    Skotte, J H

    1996-02-01

    The purpose of this study was to assess exposure to high-frequency transient (HFT) electromagnetic fields in occupational and residential environments. Exposure to HFT electromagnetic fields was measured with personal dosimeters for 301 volunteers (396 measurements) in periods of 24 h in both occupational and residential environments. The study included electrical utility workers (generation, transmission, distribution, substation), office and industrial workers, and people living near high-power transmission lines. The measure of exposure to HFT fields was specified as the proportion of time (parts per million) in which the electric field exceeds a nominal threshold level of 200 V.m-1 at 5-20 MHz. Recently the specification of the HFT channel of the dosimeter has been found to be incomplete; therefore a testing of the threshold level and the sensitivity to electromagnetic fields from radio-telephones was carried out. The percentage of measurements with a mean workday exposure above 0.1 ppm was 6.5-9.4% for the utility groups and 0.9% for all the nonwork measurements. It is likely that the use of radio-telephones has contributed significantly to the number of HFT events in some of the measurements, especially for the generation workers. The nominal threshold level of the dosimeter was found to vary considerably depending on the polarization of the field (20-400 V.m-1 at 13.56 MHz for one instrument). Generally speaking, HFT fields appeared infrequently. The workday exposure to HFT fields and 50 Hz magnetic fields ranked the groups differently. There is a need for developing instrumentation for HFT field measurements further.

  2. Controlling Electromagnetic Field by Graded Meta-materials

    Science.gov (United States)

    Sun, Lei

    Metamaterials , i.e. artificial materials with electromagnetic properties not readily available in nature, have become a major research topic in both scientific and engineering communities. Being different from conventional materials, metamaterials possess peculiar electromagnetic properties, e.g. negative refractive index, depending on their structures. In particular, metamaterials form a basis for achieving cloaking device that makes an object invisible or transparency to the probing electromagnetic wave. This topic has significant impact on various fields ranging from optics, medicine, biology to nanotechnology. Several cloaking techniques have been proposed by different research groups, namely, anomalous localized resonance, transformation optics, and scattering cancellation, etc. Each of them has its own advantages and disadvantages. For instance, the limitation in working frequency is a primary disadvantage of them. This thesis is concentrated on controlling electromagnetic field by graded metamaterials, i.e, metamaterials with graded structures, with the objective to realize the broadband electromagnetic transparency by extending the working frequency. Regarding the limitations of existing cloaking techniques, we propose the graded model based on the scattering cancellation technique, because it does not rely on resonant phenomena, and is fairly robust to relatively high variations of the shape and electromagnetic properties of the cloaked object. We modify the original Mie theory and Rayleigh scattering theory to deal with the graded metamaterial structures, and calculate the scattering cross section of graded isotropic and anisotropic spherical structures, an alytically and numerically. For the graded isotropic spherical structure, we achieve the exact analytic expressions for both full-wave and Rayleigh scattering cross sections, within our modified Mie theory and Rayleigh scattering theory. The numerical studies on the scattering cross sections clearly

  3. Designing localized electromagnetic fields in a source-free space.

    Science.gov (United States)

    Borzdov, George N

    2002-06-01

    An approach to characterizing and designing localized electromagnetic fields, based on the use of differentiable manifolds, differentiable mappings, and the group of rotation, is presented. By way of illustration, novel families of exact time-harmonic solutions to Maxwell's equations in the source-free space--localized fields defined by the rotation group--are obtained. The proposed approach provides a broad spectrum of tools to design localized fields, i.e., to build-in symmetry properties of oscillating electric and magnetic fields, to govern the distributions of their energy densities (both size and form of localization domains), and to set the structure of time-average energy fluxes. It is shown that localized fields can be combined as constructive elements to obtain a complex field structure with desirable properties, such as one-, two-, or three-dimensional field gratings. The proposed approach can be used in designing localized electromagnetic fields to govern motion and state of charged and neutral particles. As an example, motion of relativistic electrons in one-dimensional and three-dimensional field gratings is treated.

  4. Modeling Atmospheric Electromagnetic Field Following a Lightning Discharge

    Science.gov (United States)

    Davydenko, S.; Mareev, E.; Sergeev, A. S.

    2013-12-01

    A numerical model describing the electromagnetic field in the vicinity of an isolated lightning discharge is developed. Both the slow transient (quasistatic) electric field caused by the Maxwell relaxation of the charge disturbance and fast transient (electromagnetic pulse) are calculated in a plane atmosphere using the FDTD method. The lightning discharge is presented as a pulse current producing a distributed charge dipole inside the thundercloud in a case of intra-cloud (IC) flash or monopole charge in a case of cloud-to-ground (CG) flash. A temporal profile of the discharge current implies an existence of the return stroke, continuous current, and its fine features like the M-component. Temporal and spatial dependences of the atmospheric electric field on the flash type (IC or CG), distance to the discharge, disturbance of the electric conductivity inside the thundercloud, altitude(s) and lateral scale(s) of the charge region(s), temporal profile of the discharge current, and velocity of the return stroke are considered. A dependence of the net electric charge transferred to the upper atmospheric layers on the parameters of IC and CG flashes is studied. It is shown that both IC and CG flashes could serve as effective sources in the global electric circuit. A retrieval of the basic discharge parameters on the results of the one- or multipoint measurements of the both electromagnetic and quasistatic electric fields is discussed.

  5. Biological effects of electromagnetic fields | Yalçın | African Journal ...

    African Journals Online (AJOL)

    Recently, the possible effects of extra low frequency electromagnetic fields on the public health have become an interesting subject. Generally, electromagnetic fields occur around the high voltage lines. However, electromagnetic fields also occur with some electrical machines use for fun and TV used routinely at our home ...

  6. Media coverage on electromagnetic fields and health: Content analysis of Dutch newspaper articles and websites

    NARCIS (Netherlands)

    Claassen, E.A.M.; Smid, T.; Woudenberg, F.; Timmermans, D.R.M.

    2012-01-01

    The way health risks of electromagnetic fields are portrayed in the media may shape public concerns that the growing exposure to electromagnetic fields in daily life constitutes a health hazard. We analysed the content of information on electromagnetic fields and health in Dutch media to identify

  7. ELECTROMAGNETIC PROCESSES IN STRONG CRYSTALLINE FIELDS

    CERN Document Server

    Uggerhoj, U I; Esberg, J; Knudsen, H; Lund, M; Møller, S P; Sørensen, A H; Thomsen, A H; Uggerhøj, U I; Geissel, H; Scheidenberger, C; Weick, H; Winfield, J; Sona, P; Connell S; Ballestrero, S; Ketel, T; Dizdar, A; Mangiarotti, A

    2009-01-01

    As an addendum to the NA63 proposal cite{Ande05}, we propose to measure 1) the Landau-Pomeranchuk-Migdal (LPM) effect in low-$Z$ targets, 2) Magnetic suppression of incoherent bremsstrahlung resulting from exposure to an external field during the emission event, and 3) the bremsstrahlung emission from relativistic ($gamma=170$), fully stripped Pb nuclei penetrating various amorphous targets. Concerning the LPM effect, both the 'traditional' Migdal approach and the modern treatment by Baier and Katkov display inaccuracies, i.e. a possible lack of applicability in low-$Z$ targets. Moreover, the LPM effect has been shown to have a significant impact on giant air showers for energies in the EeV range - evidently processes in a low-$Z$ material. A measurement of magnetic suppression is demanding in terms of necessary accuracy (an expected $lesssim$15% effect), but would prove the existence of a basic interplay between coherent and incoherent processes, also believed to be significant in beamstrahlung emission. For...

  8. Invariant superoscillatory electromagnetic fields in 3D-space

    Science.gov (United States)

    Makris, K. G.; Papazoglou, D. G.; Tzortzakis, S.

    2017-01-01

    We derive exact solutions of Maxwell’s equations based on superoscillatory superpositions of vectorial Bessel beams. These novel beams are diffraction-free and can support subwavelength features in their transverse electromagnetic fields, without the presence of any evanescent waves. These features can be propagated into the far field. Approximate solutions in closed form are also derived based on asymptotic expansions of Bessel functions for simple prescribed subwavelength patterns. The superoscillatory characteristics of both electric, magnetic field components (transverse and longitudinal), and the Poynting vector, as well as, the effect of nonparaxiality are systematically investigated.

  9. Two-Dimensional Electron System in Electromagnetic Radiation Field

    Science.gov (United States)

    Lungu, Radu Paul; Manolescu, Andrei

    We consider a two-dimensional electron gas in the presence of a monochromatic linear polarized electromagnetic field, within the Floquet formalism. The Floquet states have a simple relation with the energy eigenstates in the absence of the field. Therefore the single-particle and the two-particle Green functions of the many-body system with Coulomb interactions, in the radiation field, can be formally calculated by the standard diagrammatic techniques, as for the conservative system. We derive the elementary excitations of quasi-particle type, the plasma dispersion relation, and the ground state quasi-energy, and we relate them to the corresponding results for the conservative system.

  10. Steady electric fields and currents elementary electromagnetic theory

    CERN Document Server

    Chirgwin, B H; Kilmister, C W

    2013-01-01

    Steady Electric Fields and Currents, Volume 1 is an introductory text to electromagnetism and potential theory. This book starts with the fields associated with stationary charges and unravels the stationary condition to allow consideration of the flow of steady currents in closed circuits. The opening chapter discusses the experimental results that require mathematical explanation and discussion, particularly those referring to phenomena that question the validity of the simple Newtonian concepts of space and time. The subsequent chapters consider steady-state fields, electrostatics, dielectr

  11. Radiofrequency electromagnetic fields in the Cookridge area of Leeds

    CERN Document Server

    Fuller, K; Judd, P M; Lowe, A J; Shaw, J

    2002-01-01

    On the 8 and 9 May 2002 representatives of the National Radiological Protection Board (NRPB) performed a radiofrequency electromagnetic field survey in the Cookridge area of Leeds in order to assess exposure to radio signals from transmitters mounted on a water tower/a lattice tower and a radio station tower. Guidelines on limiting exposure to radio signals have been published by NRPB and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines are designed to prevent established adverse effects on human health. During this survey, the total exposures due to all radio signals from 30 MHz to 18000 MHz (18 GHz) were measured. This frequency range was chosen as it includes mobile phone base station transmissions, which are at around 900 and 1800 MHz and super high frequency (SHF) transmissions from most of the large microwave dish antennas mounted on the towers. In addition, other major sources of radiofrequency electromagnetic fields in the environment such as broadcast radio...

  12. Numerical Modeling of Electromagnetic Field Effects on the Human Body

    Directory of Open Access Journals (Sweden)

    Zuzana Psenakova

    2006-01-01

    Full Text Available Interactions of electromagnetic field (EMF with environment and with tissue of human beings are still under discussion and many research teams are investigating it. The human simulation models are used for biomedical research in a lot of areas, where it is advantage to replace real human body (tissue by the numerical model. Biological effects of EMF are one of the areas, where numerical models are used with many advantages. On the other side, this research is very specific and it is always quite hard to simulate realistic human tissue. This paper deals with different possibilities of numerical modelling of electromagnetic field effects on the human body (especially calculation of the specific absorption rate (SAR distribution in human body and thermal effect.

  13. Electromagnetic and transient shielding effectiveness for near-field sources

    Directory of Open Access Journals (Sweden)

    C. Möller

    2007-06-01

    Full Text Available The contribution deals with an investigation of the recently proposed definitions for the electromagnetic and transient shielding effectiveness (SE in the case of an electric-dipole near-field source. To this end, new factors are introduced which depend on the distance between the dipole source and the measurement point inside the shield and which are valid for perpendicularly (with respect to the distance vector polarized dipoles. Numerical results support and confirm the theoretical derivations.

  14. Induction of Cell Activation Processes by Low Frequency Electromagnetic Fields

    OpenAIRE

    Myrtill Simkó

    2004-01-01

    Electromagnetic fields (EMF) such as those from electric power transmission and distribution lines (50/60 Hz) have been associated with increased risk of childhood leukemia, cancer of the nervous system, and lymphomas. Several in vitro studies on EMF effects were performed to clarify the existing controversies, define the risks, and determine the possible mechanisms of adverse effects. In some of these reports, the effects were related to other mechanisms of carcinogenesis. Modification in ce...

  15. Effects of Pulsed Electromagnetic Fields on Osteoporosis Model

    Science.gov (United States)

    Xiaowei, Yang; Liming, Wang; Guan, Z. C.; Yaou, Zhang; Xiangpeng, Wang

    The purpose of this paper was to investigate the preventive effects and long term effects of extremely low frequency pulsed electromagnetic fields (PEMFs), generated by circular coils and pulsed electromagnetic fields stimulators, on osteoporosis in bilaterally ovariectomized rats. In preventive experiment, thirty three-month old female Sprague-Dawley rats were randomly divided into three different groups: sham (SHAM), ovariectomy (OVX), PEMFs stimulation (PEMFs). All rats were subjected to bilaterally ovariectomy except those in SHAM group. The PEMFs group was exposed to pulsed electromagnetic fields with frequency 15 Hz, peak magnetic induction density 2.2mT and exposure time 2 hours per day. The bone mineral density (BMD) of vertebra and left femur were measured by dual energy X-ray absorptiometry at eighth week, twelfth week and sixteenth week after surgery. In long term effects experiment, forty four rats were randomly divided into sham (14 rats, SHAM), ovariectomy group (10 rats, OVX), 15Hz PEMFs group(10 rats, 15Hz) and 30Hz PEMFs group(10 rats, 30Hz) at twenty-sixth week after surgery. Rats in PEMFs groups were stimulated sixteen weeks. In preventive experiment, the Corrected BMD of vertebra and femur was significantly higher than that of OVX group after 16 weeks (P<0.001, P<0.001 respectively). In long term effects experiment, the vertebral BMD of 15Hz PEMFs group and 30Hz PEMFs group was significantly higher than that of OVX groups (P<0.01, P<0.05 respectively). The experimental results demonstrated that extremely low intensity, low frequency, single pulsed electromagnetic fields significantly slowed down the loss of corrected vertebral and femoral BMD in bilaterally ovariectomized rats and suggest that PEMFs may be beneficial in the treatment of osteoporosis.

  16. Immune Response to Electromagnetic Fields through Cybernetic Modeling

    Science.gov (United States)

    Godina-Nava, J. J.; Segura, M. A. Rodríguez; Cadena, S. Reyes; Sierra, L. C. Gaitán

    2008-08-01

    We study the optimality of the humoral immune response through a mathematical model, which involves the effect of electromagnetic fields over the large lymphocytes proliferation. Are used the so called cybernetic variables in the context of the matching law of microeconomics or mathematical psychology, to measure the large lymphocytes population and to maximize the instantaneous antibody production rate in time during the immunologic response in order to most efficiently inactivate the antigen.

  17. NEW APPROACH OF ELECTROMAGNETIC FIELDS OF THE LIGHTNING DISCHARGE

    OpenAIRE

    Dib Djalel; Mordjaoui Mourad; Hocine Labar

    2013-01-01

    Despite the significant developments in the protection means of electrical and electronic systems against the lightning and its effects. With its unpredictability and aggress if character, the lightning is the most dangerous phenomenon for electrical systems, which requires more interest and greater effort by researchers and designers means of protection. We present in this study a new analytic model of transient electromagnetic fields radiated by the lightning channel. To better estimate our...

  18. Electromagnetic fields in medicine - The state of art.

    Science.gov (United States)

    Pasek, Jarosław; Pasek, Tomasz; Sieroń-Stołtny, Karolina; Cieślar, Grzegorz; Sieroń, Aleksander

    2016-01-01

    Intense development of methods belonging to physical medicine has been noted recently. There are treatment methods, which in many cases lead to reduction treatment time and positively influence on quality of life treatment patients. The present physical medicine systematically extends their therapeutic possibilities. This above applies to illnesses and injuries of locomotor system, diseases affecting of soft tissues, as well as chronic wounds. The evidence on this are the results of basic and clinical examinations relating the practical use of electromagnetic fields in medicine. In this work the authors introduced the procedure using the current knowledge relating to physical characteristic and biological effects of the magnetic fields. In the work the following methods were used: static magnetic fields, spatial magnetic fields, the variable magnetic fields both with laser therapy (magnetolaserotherapy) and variable magnetic fields both with light optical non-laser (magnetoledtherapy) talked.

  19. 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.

  20. Spectrum of classes of point emitters of electromagnetic wave fields.

    Science.gov (United States)

    Castañeda, Román

    2016-09-01

    The spectrum of classes of point emitters has been introduced as a numerical tool suitable for the design, analysis, and synthesis of non-paraxial optical fields in arbitrary states of spatial coherence. In this paper, the polarization state of planar electromagnetic wave fields is included in the spectrum of classes, thus increasing its modeling capabilities. In this context, optical processing is realized as a filtering on the spectrum of classes of point emitters, performed by the complex degree of spatial coherence and the two-point correlation of polarization, which could be implemented dynamically by using programmable optical devices.

  1. On a remarkable electromagnetic field in the Einstein Universe

    Science.gov (United States)

    Kopiński, Jarosław; Natário, José

    2017-06-01

    We present a time-dependent solution of the Maxwell equations in the Einstein universe, whose electric and magnetic fields, as seen by the stationary observers, are aligned with the Clifford parallels of the 3-sphere S^3. The conformal equivalence between Minkowski's spacetime and (a region of) the Einstein cylinder is then exploited in order to obtain a knotted, finite energy, radiating solution of the Maxwell equations in flat spacetime. We also discuss similar electromagnetic fields in expanding closed Friedmann models, and compute the matter content of such configurations.

  2. Thermodynamic fluctuations of electromagnetic field in slightly absorbing media

    Directory of Open Access Journals (Sweden)

    B.A.Veklenko

    2004-01-01

    Full Text Available A theory of thermodynamic fluctuations of electromagnetic field in slightly absorbing media is developed using the quantum electrodynamics - method of $Gamma$-operators - without phenomenology. The hypothesis offered by Yury L. Klimontovich is under consideration. The necessity of correct consideration of photon-photon correlation functions is shown. The results are compared with the ones obtained with the help of standard theory based upon fluctuation-dissipation theorem (FDT. The latter results are shown to have no field of application at least for the case of thermally excited media of the atoms described with two-level model.

  3. Interaction of Electromagnetic Radiation with Supercritical Magnetic Field

    OpenAIRE

    Shabad, A. E.

    2003-01-01

    It is pointed, that effects of refraction of electromagnetic radiation in the medium, formed by the magnetized vacuum, become essential already for relatively soft photons, not hard enough to create an electron-positron pair, including those belonging to soft gamma-, X-ray, optic and radio- range, if the magnetic field B exceeds the critical value of Bcr=m^2/e=4.4 10^13 Gauss. Three leading terms in the asymptotic expansion of the one-loop polarization operator in a constant magnetic field ar...

  4. Magnetization dynamics under electromagnetic fields in the wavepacket methods

    Science.gov (United States)

    Xiong, Bangguo; Chen, Hua; Li, Xiao; Niu, Qian

    In this work we try to understand the magnetization dynamics in magnetic materials with electrons described by the semiclasscial wavepacket methods. Using the Lagrangian of electron wavepackets under slowly varying magnetization, we can explicitly write down the dynamic equations for both electrons and magnetization order, where the mutual interplay between the two presents itself naturally. It turns out that, more general than LLG equation, the magnetization dynamics is written as a first order differential equation as for a general vector, which allows a detailed discussion on physical process studied before, such as spin transfer torque, spin orbital torque and damping mechanism, and also gives the vortex-like torques that can pump energy into the system. Since electrons are easy to control by electromagnetic fields, we expect a theory that electromagnetic fields through coupling to electrons can be used to manipulate the magnetization. It is interesting that this formalism on magnetization dynamics can be used to study the electromagnetic response of bulk electrons, from which the current and magnetization expressions are extracted that match well with previous studies.

  5. Phase-field lattice Boltzmann modeling of boiling using a sharp-interface energy solver

    Science.gov (United States)

    Mohammadi-Shad, Mahmood; Lee, Taehun

    2017-07-01

    The main objective of this paper is to extend an isothermal incompressible two-phase lattice Boltzmann equation method to model liquid-vapor phase change problems using a sharp-interface energy solver. Two discrete particle distribution functions, one for the continuity equation and the other for the pressure evolution and momentum equations, are considered in the current model. The sharp-interface macroscopic internal energy equation is discretized with an isotropic finite difference method to find temperature distribution in the system. The mass flow generated at liquid-vapor phase interface is embedded in the pressure evolution equation. The sharp-interface treatment of internal energy equation helps to find the interfacial mass flow rate accurately where no free parameter is needed in the calculations. The proposed model is verified against available theoretical solutions of the two-phase Stefan problem and the two-phase sucking interface problem, with which our simulation results are in good agreement. The liquid droplet evaporation in a superheated vapor, the vapor bubble growth in a superheated liquid, and the vapor bubble rising in a superheated liquid are analyzed and underlying physical characteristics are discussed in detail. The model is successfully tested for the liquid-vapor phase change with large density ratio up to 1000.

  6. Seminal magnetic fields from inflato-electromagnetic inflation

    Energy Technology Data Exchange (ETDEWEB)

    Membiela, Federico Agustin; Bellini, Mauricio [Universidad Nacional de Mar del Plata, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR), Buenos Aires (Argentina)

    2012-10-15

    We extend some previous attempts to explain the origin and evolution of primordial magnetic fields during inflation induced from a 5D vacuum. We show that the usual quantum fluctuations of a generalized 5D electromagnetic field cannot provide us with the desired magnetic seeds. We show that special fields without propagation on the extra non-compact dimension are needed to arrive at appreciable magnetic strengths. We also identify a new magnetic tensor field B{sub ij} in this kind of extra dimensional theory. Our results are in very good agreement with observational requirements, in particular from TeV blazars and CMB radiation limits we see that primordial cosmological magnetic fields should be close to scale invariance. (orig.)

  7. Charged and Electromagnetic Fields from Relativistic Quantum Geometry

    Directory of Open Access Journals (Sweden)

    Marcos R. A. Arcodía

    2016-06-01

    Full Text Available In the recently introduced Relativistic Quantum Geometry (RQG formalism, the possibility was explored that the variation of the tensor metric can be done in a Weylian integrable manifold using a geometric displacement, from a Riemannian to a Weylian integrable manifold, described by the dynamics of an auxiliary geometrical scalar field θ, in order that the Einstein tensor (and the Einstein equations can be represented on a Weyl-like manifold. In this framework we study jointly the dynamics of electromagnetic fields produced by quantum complex vector fields, which describes charges without charges. We demonstrate that complex fields act as a source of tetra-vector fields which describe an extended Maxwell dynamics.

  8. An MOT-TDIE solver for analyzing transient fields on graphene-based devices

    KAUST Repository

    Shi, Yifei

    2016-11-02

    A marching on-in-time (MOT) scheme for analyzing transient electromagnetic wave interactions on devices consisting of graphene sheets and dielectric substrates is proposed. The MOT scheme discretizes time domain resistive boundary condition (TD-RBC) and Poggio-Miller-Chang-Harrington-Wu-Tsai (TD-PMCHWT) integral equation, which are enforced on the surfaces of the graphene and dielectric substrate, respectively. The expressions of the time domain resistivity and conductivity of the graphene sheet are obtained analytically from the intra-band contribution formulated in frequency domain. Numerical results, which demonstrate the applicability of the proposed scheme, are presented.

  9. Shielding of electromagnetic fields of current sources by spherical enclosures

    Science.gov (United States)

    Shastry, S. V. K.; Rao, M. N.; Katti, V. R.

    Expressions for the shielding effectiveness of a conductive spherical enclosure excited by a Hertzian dipole have been derived using the dyadic Green's function technique. This technique has the advantage that the fields inside or outside the enclosure due to arbitrary current distribution may be found by employing the same set of dyadic Green's functions. The shielding effectiveness for plane wave incidence has been determined by considering the limiting case of the current source external to the spherical shell. Computed values of shielding effectiveness deduced in this manner have been compared with those obtained by the numerical evaluation of the expressions derived by earlier authors. The theory presented here may be useful to EMC (electromagnetic compatibility) engineers who must consider electromagnetic coupling from current sources in the vicinity of shielding enclosures.

  10. Effects of Bluetooth device electromagnetic field on hearing: pilot study.

    Science.gov (United States)

    Balachandran, R; Prepageran, N; Prepagaran, N; Rahmat, O; Zulkiflee, A B; Hufaida, K S

    2012-04-01

    The Bluetooth wireless headset has been promoted as a 'hands-free' device with a low emission of electromagnetic radiation. To evaluate potential changes in hearing function as a consequence of using Bluetooth devices, by assessing changes in pure tone audiography and distortion production otoacoustic emissions. Prospective study. Thirty adult volunteers were exposed to a Bluetooth headset device (1) on 'standby' setting for 6 hours and (2) at full power for 10 minutes. Post-exposure hearing was evaluated using pure tone audiography and distortion production otoacoustic emission testing. There were no statistically significant changes in hearing, as measured above, following either exposure type. Exposure to the electromagnetic field emitted by a Bluetooth headset, as described above, did not decrease hearing thresholds or alter distortion product otoacoustic emissions.

  11. Work and energy for particles in electromagnetic field

    Science.gov (United States)

    Babajanyan, S. G.

    2017-07-01

    Defining the energy and work for particles interacting with electromagnetic field (EMF) is an open problem, because—due to the gauge-freedom—there exist various non-equivalent possibilities. It is argued that a consistent definition can be provided via the Lorenz gauge. To this end, I work out a system of two electromagnetically coupled classical particles. One of them is much heavier and models the source of work. The definition of energy in the Lorenz gauge is causal and consistent, because it leads to an approximate conservation law due to which the work done by the heavy particle (source of work) can be defined either via the kinetic energy of the heavy particle, or via the full time-dependent energy (kinetic + potential in the Lorenz gauge) of the light particle.

  12. Behavior of radon progeny in low frequency electromagnetic fields

    CERN Document Server

    Oda, K; Yamamoto, T

    1999-01-01

    Whether the electro-magnetic (EM) fields are carcinogenic or not still remains to be discussed from scientific point of view. Recently a possibility was pointed out that increased deposition of radon progeny in the EM-fields should enhance exposure dose to internal body. We investigated the behavior of charged sup 2 sup 2 sup 2 Rn progeny and aerosols containing them by measuring the pattern and the magnitude of the deposition rate of decay products on both CR-39 track detectors and imaging plates under various conditions. We concluded that the attachment to wire cables should be increased mainly by electric component of low frequency EM-fields and possibly by electric field induced by strong changing magnetic ones.

  13. ELECTRON HOLOGRAPHY OF ELECTROMAGNETIC FIELDS - RECENT THEORETICAL ADVANCES.

    Energy Technology Data Exchange (ETDEWEB)

    BELEGGIA,M.; POZZI, G.; TONOMURA, A.

    2007-01-01

    It has been shown in this work that the Fourier space approach can be fruitfully applied to the calculation of the fields and the associated electron optical phase shift of several magnetic and electrostatic structures, like superconducting vortices in conventional and high-T{sub c} superconductors, reverse biased p-n junctions, magnetic domains and nanoparticles. In all these cases, this novel approach has led to unexpected but extremely interesting results, very often expressed in analytical form, which allow the quantitative and reliable interpretation of the experimental data collected by means of electron holography or of more conventional Lorentz microscopy techniques. Moreover, it is worth recalling that whenever long-range electromagnetic fields are involved, a physical model of the object under investigation is necessary in order to take into account correctly the perturbation of the reference wave induced by the tail of the field protruding into the vacuum. For these reasons, we believe that the Fourier space approach for phase computations we have introduced and discussed in this chapter will represent an invaluable tool for the investigation of electromagnetic fields at the meso- and nano-scale.

  14. Difficulties in applying numerical simulations to an evaluation of occupational hazards caused by electromagnetic fields.

    Science.gov (United States)

    Zradziński, Patryk

    2015-01-01

    Due to the various physical mechanisms of interaction between a worker's body and the electromagnetic field at various frequencies, the principles of numerical simulations have been discussed for three areas of worker exposure: to low frequency magnetic field, to low and intermediate frequency electric field and to radiofrequency electromagnetic field. This paper presents the identified difficulties in applying numerical simulations to evaluate physical estimators of direct and indirect effects of exposure to electromagnetic fields at various frequencies. Exposure of workers operating a plastic sealer have been taken as an example scenario of electromagnetic field exposure at the workplace for discussion of those difficulties in applying numerical simulations. The following difficulties in reliable numerical simulations of workers' exposure to the electromagnetic field have been considered: workers' body models (posture, dimensions, shape and grounding conditions), working environment models (objects most influencing electromagnetic field distribution) and an analysis of parameters for which exposure limitations are specified in international guidelines and standards.

  15. An Optimization of Pulsed ElectroMagnetic Fields Study

    Science.gov (United States)

    Goodwin, Thomas J.

    2006-01-01

    To date, in our research we have focused on the use of normal human neuronal progenitor (NHNP) cells because of their importance in human nervous system regeneration, development and maintenance, but we have developed 2-D and 3-D bioreactors that can accommodate any cell line. In this Project, we will include the use of tissues important for physiological regeneration: Human osteoblasts or chondrocytes, and vascular cells. Our initial results with the NHNP cells were quite startling using extremely low-level electromagnetic fields (5 microtesla at 10Hz; 6mA). The low-amplitude, rapidly time-varying electromagnetic fields exert a very potent effect on the proliferation, morphology, and gene expression of the cells in culture, both in standard 2-dimensional culture plates as well as cells organized into 3-dimensional tissue-like assemblies (TLAs) in a 3D bioreactor. We have replicated our preliminary results many, many times, have analyzed the gene expression using gene arrays (followed by Luminex analysis for protein production), and have monitored cell proliferation, orientation, morphology, and glucose metabolism, and we are confident that we have a stable and reliable model to study the control of high-level cellular processes by application of low-amplitude, time varying electromagnetic fields (TVEMF) (1, 2). In additional studies at the University of Michigan, we have been able to generate functional in vitro engineered mammalian skeletal muscle, and have employed nerve-muscle co-culture techniques to promote axonal sprouting. We believe that nearly all tissues, in particular, neural, are susceptible to the influences of low-level TVEMF.

  16. RF Electromagnetic Field Treatment of Tetragonal Kesterite CZTSSe Light Absorbers

    Science.gov (United States)

    Semenenko, Mykola O.; Babichuk, Ivan S.; Kyriienko, Oleksandr; Bodnar, Ivan V.; Caballero, Raquel; Leon, Maximo

    2017-06-01

    In this work, we propose a method to improve electro-optical and structural parameters of light-absorbing kesterite materials. It relies on the application of weak power hydrogen plasma discharges using electromagnetic field of radio frequency range, which improves homogeneity of the samples. The method allows to reduce strain of light absorbers and is suitable for designing solar cells based on multilayered thin film structures. Structural characteristics of tetragonal kesterite Cu2ZnSn(S, Se)4 structures and their optical properties were studied by Raman, infrared, and reflectance spectroscopies. They revealed a reduction of the sample reflectivity after RF treatment and a modification of the energy band structure.

  17. Accuracy Improvement in Magnetic Field Modeling for an Axisymmetric Electromagnet

    Science.gov (United States)

    Ilin, Andrew V.; Chang-Diaz, Franklin R.; Gurieva, Yana L.; Il,in, Valery P.

    2000-01-01

    This paper examines the accuracy and calculation speed for the magnetic field computation in an axisymmetric electromagnet. Different numerical techniques, based on an adaptive nonuniform grid, high order finite difference approximations, and semi-analitical calculation of boundary conditions are considered. These techniques are being applied to the modeling of the Variable Specific Impulse Magnetoplasma Rocket. For high-accuracy calculations, a fourth-order scheme offers dramatic advantages over a second order scheme. For complex physical configurations of interest in plasma propulsion, a second-order scheme with nonuniform mesh gives the best results. Also, the relative advantages of various methods are described when the speed of computation is an important consideration.

  18. 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.

  19. Group classification of charged particle motion in stationary electromagnetic fields

    Science.gov (United States)

    Kallinikos, N.

    2017-11-01

    In this paper, we classify in terms of Lie point symmetries the three-dimensional nonrelativistic motion of charged particles in arbitrary time-independent electromagnetic fields. The classification is made on the ground of equivalence transformations, and when the system is nonlinear and particularly for inhomogeneous and curved magnetic fields, it is also complete. Using the homogeneous Maxwell's equations as auxiliary conditions for consistency, in which case the system amounts to a Lagrangian of three degrees of freedom with velocity-dependent potentials, the equivalence group stays the same. Therefore, instead of the actual fields, the potentials are equally employed and their gauge invariance results in an infinite-dimensional equivalence algebra, which nevertheless projects to finite-dimensional symmetry algebras. Subsequently, optimal systems of equivalence subalgebras are obtained that lead to one-, two-, and three-parameter extended symmetry groups, besides the obvious time translations. Finally, based on symmetries of Noether type, aspects of complete integrability are discussed, as well.

  20. Parametric Study of the Scattered Electromagnetic Field by Differently-Shaped Buried Objects in Various Scenarios

    Science.gov (United States)

    Stoja, Endri; Hoxha, Julian; Domnori, Elton; Pajewski, Lara; Frezza, Fabrizio

    2017-04-01

    In this study the electromagnetic field scattered by a buried object is obtained by use of a commercial full-wave frequency-domain solver which implements the Finite Element Method (FEM). The buried object is supposed to have different simple shapes and material composition such as a cylinder or cylindrical shell modelling for example a void in concrete or a poly-vinyl chloride (PVC) pipeline, respectively. Material properties available in literature are correctly modelled by data interpolation. The model is excited by a linearly-polarized plane wave impinging normally on the interface between air and soil/cement half-space. Comparison with simulation data provided by another simulator implementing the finite-difference time domain (FDTD) technique in the case of a simple buried perfect electric cylinder allows for FEM data validation. We further study the properties and the spatial variation of the scattered fields in different contexts by varying the geometrical and material properties of the model relative to the impinging wave characteristics. The aim is to clearly determine the conditions under which detection is possible. Moreover, by application of signal processing techniques to scattered field data, the position, shape, and object orientation recognition problems are considered. Results from different DSP algorithms are compared with the goal to find the best performing one relative to the context. Performance is evaluated in terms of detection success and resolving ability. The use of ground penetrating radar (GPR) techniques in the field of Civil Engineering offers inspection capabilities in the structure with no destructive intervention. Acknowledgement This abstract is a contribution to COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar", www.GPRadar.eu, www.cost.eu.

  1. Cellular effects of extremely low frequency (ELF) electromagnetic fields.

    Science.gov (United States)

    Santini, Maria T; Rainaldi, Gabriella; Indovina, Pietro L

    2009-04-01

    The major areas of research that have characterised investigation of the impact of extremely low frequency (ELF) electromagnetic fields on living systems in the past 50 years are discussed. In particular, selected studies examining the role of these fields in cancer, their effects on immune and nerve cells, and the positive influence of these ELF fields on bone and nerve cells, wound healing and ischemia/reperfusion injury are explored. The literature indicates that there is still no general agreement on the exact biological detrimental effects of ELF fields, on the physical mechanisms that may be behind these effects or on the extent to which these effects may be harmful to humans. Nonetheless, the majority of the in vitro experimental results indicate that ELF fields induce numerous types of changes in cells. Whether or not the perturbations observed at the cellular level can be directly extrapolated to negative effects in humans is still unknown. However, the myriad of effects that ELF fields have on biological systems should not be ignored when evaluating risk to humans from these fields and, consequently, in passing appropriate legislation to safeguard both the general public and professionally-exposed workers. With regard to the positive effects of these fields, the possibility of testing further their efficacy in therapeutic protocols should also not be overlooked.

  2. Parallel time domain solvers for electrically large transient scattering problems

    KAUST Repository

    Liu, Yang

    2014-09-26

    Marching on in time (MOT)-based integral equation solvers represent an increasingly appealing avenue for analyzing transient electromagnetic interactions with large and complex structures. MOT integral equation solvers for analyzing electromagnetic scattering from perfect electrically conducting objects are obtained by enforcing electric field boundary conditions and implicitly time advance electric surface current densities by iteratively solving sparse systems of equations at all time steps. Contrary to finite difference and element competitors, these solvers apply to nonlinear and multi-scale structures comprising geometrically intricate and deep sub-wavelength features residing atop electrically large platforms. Moreover, they are high-order accurate, stable in the low- and high-frequency limits, and applicable to conducting and penetrable structures represented by highly irregular meshes. This presentation reviews some recent advances in the parallel implementations of time domain integral equation solvers, specifically those that leverage multilevel plane-wave time-domain algorithm (PWTD) on modern manycore computer architectures including graphics processing units (GPUs) and distributed memory supercomputers. The GPU-based implementation achieves at least one order of magnitude speedups compared to serial implementations while the distributed parallel implementation are highly scalable to thousands of compute-nodes. A distributed parallel PWTD kernel has been adopted to solve time domain surface/volume integral equations (TDSIE/TDVIE) for analyzing transient scattering from large and complex-shaped perfectly electrically conducting (PEC)/dielectric objects involving ten million/tens of millions of spatial unknowns.

  3. Electromagnetic fields and Green's functions in elliptical vacuum chambers

    Science.gov (United States)

    Persichelli, S.; Biancacci, N.; Migliorati, M.; Palumbo, L.; Vaccaro, V. G.

    2017-10-01

    In this paper, we discuss the electromagnetic interaction between a point charge travelling inside a waveguide of elliptical cross section, and the waveguide itself. By using a convenient expansion of the Mathieu functions, useful in particular for treating a variety of problems in applied mathematics and physics with elliptic geometry, we first obtain the longitudinal electromagnetic field of a point charge (Green's function) in free space in terms of elliptical coordinates. This expression allows, then, to calculate the scattered field due to the boundary conditions in our geometry. By summing the contribution of the direct or primary field and the indirect field scattered by the boundary, after a careful choice of some expansion expressions, we derive a novel formula of the longitudinal electric field, in any transverse position of the elliptical cross section, generated by the charge moving along the longitudinal axis of the waveguide. The obtained expression is represented in a closed form, it can be differentiated and integrated, it can be used to fully describe the radiation process of a particle beam travelling inside a waveguide of elliptical cross section, and it is valid for any elliptic geometry. The equations are used to evaluate the coupling impedance due to indirect space charge in case of elliptical geometry. In addition, they are useful as preliminary studies for the determination of the coupling impedance in different cases involving elliptic vacuum chambers, as, for example, the effect of the finite conductivity of the beam pipe wall or the geometrical variation of the vacuum chamber due to elliptic step transitions existing in some accelerators.

  4. Nonthermal electromagnetic fields: from first messenger to therapeutic applications.

    Science.gov (United States)

    Pilla, Arthur A

    2013-06-01

    Nonthermal pulsed electromagnetic fields, from low frequency to pulse-modulated radio frequency, have been successfully employed as adjunctive therapy for the treatment of delayed and non-union fractures, fresh fractures and chronic wounds. Recent increased understanding of the mechanism of action of electromagnetic fields (EMF) has permitted technologic advances allowing the development of EMF devices which are portable and disposable, can be incorporated into dressings, supports and casts, and can be used over clothing. This broadens the use of non-pharmacological, non-invasive EMF therapy to the treatment of postoperative pain and edema to enhance surgical recovery. EMF therapy is rapidly becoming a standard part of surgical care, and new, more significant, clinical applications for osteoarthritis, brain and cardiac ischemia and traumatic brain injury are in the pipeline. This study reviews recent evidence which suggests that calmodulin (CaM)-dependent nitric oxide signaling is involved in cell and tissue response to weak nonthermal EMF signals. There is abundant evidence that EMF signals can be configured a priori to increase the rate of CaM activation, which, in turn, can modulate the biochemical cascades living cells and tissues employ in response to external insult. Successful applications in pilot clinical trials, coupled with evidence at the cellular and animal levels, provide support that EMF is a first messenger that can modulate the response of challenged biological systems.

  5. Quantum Mechanics Action of ELF Electromagnetic Fields on Living Organisms

    Science.gov (United States)

    Godina-Nava, J. J.

    2010-10-01

    There is presently an intense discussion if extremely low frequency electromagnetic field (ELF-EMF) exposure has consequences for human health. This include exposure to structures and appliances from this range of frequency in the electromagnetic (EM) spectrum. Biological effects of such exposures have been noted frequently, although the implications for specific health effects is not that clear. The basic interactions mechanisms between such fields and living matter is unknown. Numerous hypotheses have been suggested, although none is convincingly supported by experimental data. Various cellular components, processes, and systems can be affected by EMF exposure. Since it is unlikely that EMF can induce DNA damage directly, most studies have examined EMF effects on the cell membrane level, general and specific gene expression, and signal transduction pathways. Even more, a large number of studies have been performed regarding cell proliferation, cell cycle regulation, cell differentiation, metabolism, and various physiological characteristics of cells. The aim of this letter is present the hypothesis of a possible quantum mechanic effect generated by the exposure of ELF EMF, an event which is compatible with the multitude of effects observed after exposure. Based on an extensive literature review, we suggest that ELF EMF exposure is able to perform such activation restructuring the electronic level of occupancy of free radicals in molecules interacting with DNA structures.

  6. Near-field electromagnetic theory for thin solar cells.

    Science.gov (United States)

    Niv, A; Gharghi, M; Gladden, C; Miller, O D; Zhang, X

    2012-09-28

    Current methods for evaluating solar cell efficiencies cannot be applied to low-dimensional structures where phenomena from the realm of near-field optics prevail. We present a theoretical approach to analyze solar cell performance by allowing rigorous electromagnetic calculations of the emission rate using the fluctuation-dissipation theorem. Our approach shows the direct quantification of the voltage, current, and efficiency of low-dimensional solar cells. This approach is demonstrated by calculating the voltage and the efficiency of a GaAs slab solar cell for thicknesses from several microns down to a few nanometers. This example highlights the ability of the proposed approach to capture the role of optical near-field effects in solar cell performance.

  7. Electromagnetic field limits set by the V-Curve.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jorgenson, Roy Eberhardt [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hudson, Howard Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-07-01

    When emitters of electromagnetic energy are operated in the vicinity of sensitive components, the electric field at the component location must be kept below a certain level in order to prevent the component from being damaged, or in the case of electro-explosive devices, initiating. The V-Curve is a convenient way to set the electric field limit because it requires minimal information about the problem configuration. In this report we will discuss the basis for the V-Curve. We also consider deviations from the original V-Curve resulting from inductive versus capacitive antennas, increases in directivity gain for long antennas, decreases in input impedance when operating in a bounded region, and mismatches dictated by transmission line losses. In addition, we consider mitigating effects resulting from limited antenna sizes.

  8. Circadian neuroendocrine physiology and electromagnetic field studies: Precautions and complexities

    Energy Technology Data Exchange (ETDEWEB)

    Warman, G.R.; Tripp, H.M.; Harman, V.L.; Arendt, J

    2003-07-01

    The suppression of melatonin by exposure to low frequency electromagnetic fields (EMFs) 'the melatonin hypothesis' has been invoked as a possible mechanism through which exposure to these fields may result in an increased incidence of cancer. While the effect of light on melatonin is well established, data showing a similar effect due to EMF exposure are sparse and, where present, are often poorly controlled. The current review focuses on the complexities associated with using melatonin as a marker and the dynamic nature of normal melatonin regulation by the circadian neuroendocrine axis. These are issues which the authors believe contribute significantly to the lack of consistency of results in the current literature. Recommendations on protocol design are also made which, if followed, should enable researchers to eliminate or control for many of the confounding factors associated with melatonin being an output from the circadian clock. (author)

  9. The dielectric response to the magnetic field of electromagnetic radiation

    Science.gov (United States)

    Mukherjee, Shouvik; Mukhopadhyay, Sourabh; Datta, Prasanta Kumar

    2017-04-01

    Light-matter interaction in transparent dielectrics is revisited, including the magnetic force on bound charges in the Lorentz oscillator model. The parameter ranges of incident radiation and the medium on which the magnetic field of the electromagnetic radiation will have a significant effect are traced using Floquet theory. The analysis reveals that the threshold intensity for a significant response of the magnetic field of the radiation at the second harmonic of the incident radiation can be reduced to {10}12 {{W}}{{cm}}-2 for off resonant and even lower for resonant interaction. This phenomenon has already been observed indirectly in experiments [1, 2]. Induced magnetizing current due to the magnetic force is shown to originate from a modified dielectric response, which may be useful in future magneto-optic devices, solar energy harvesting, and studying the ultrafast dynamics in doped dielectrics.

  10. Theory of a ring laser. [electromagnetic field and wave equations

    Science.gov (United States)

    Menegozzi, L. N.; Lamb, W. E., Jr.

    1973-01-01

    Development of a systematic formulation of the theory of a ring laser which is based on first principles and uses a well-known model for laser operation. A simple physical derivation of the electromagnetic field equations for a noninertial reference frame in uniform rotation is presented, and an attempt is made to clarify the nature of the Fox-Li modes for an open polygonal resonator. The polarization of the active medium is obtained by using a Fourier-series method which permits the formulation of a strong-signal theory, and solutions are given in terms of continued fractions. It is shown that when such a continued fraction is expanded to third order in the fields, the familiar small-signal ring-laser theory is obtained.

  11. MINERAL HORIZONS, ELECTROMAGNETIC FIELDS AND CIRCULAR SHAPES IN THE GRASS

    Directory of Open Access Journals (Sweden)

    Valentino Straser

    2009-12-01

    Full Text Available The occasional appearance of circular shapes in meadows and farmland located on slopes usually affected by gravitational phenomena, offered an occasion for verifying the possible relation between the position of the circles in the grass, the gravitational movement of the slope affecting its mineral horizons and the variations of electric and static magnetic fields close to the circular shapes and in the surrounding area. The stress caused by the “creeping” movement in the uderlying ground turned out to be in direct relation with the variation in the electric and magnetic fields caused by piezoelectric and piezomagnetic minerals such as quartz. The onset of the electromagnetic process involves the conversion of electric energy on the surface into an area of spherical shape which is linked with a different growth of herbaceous species compared to the surrounding vegetation.

  12. Proposal for magnetic/electromagnetic fields protection norms on national level

    OpenAIRE

    Đorđević Drago; Raković Dejan

    2008-01-01

    Introduction The modern life is not possible without application of magnetic/electromagnetic fields, which can be both helpful and harmful for human body. Influence of magnetic/electromagnetic fields on biological systems The non-ionizing radiation, especially magnetic/electromagnetic fields of all frequencies (0-300 GHz), can have many harmful effects on the human health that is confirmed by numerous epidemiological studies, studies with volunteers, animal studies, and in vitro studies. Prop...

  13. Energy flow in a bound electromagnetic field: resolution of apparent paradoxes

    Energy Technology Data Exchange (ETDEWEB)

    Kholmetskii, A L [Department of Physics, Belarusian State University, 4, Nezavisimosti Avenue, 220050 Minsk (Belarus); Yarman, T [Department of Engineering, Okan University Istanbul, Turkey and Savronik, Eskisehir (Turkey)], E-mail: kholm@bsu.by

    2008-11-15

    In this paper, we present a resolution of apparent paradoxes formulated in (Kholmetskii A L 2006 Apparent paradoxes in classical electrodynamics: the energy-momentum conservation law for a bound electromagnetic field Eur. J. Phys. 27 825-38; Kholmetskii A L and Yarman T 2008 Apparent paradoxes in classical electrodynamics: a fluid medium in an electromagnetic field Eur. J. Phys. 29 1127) and dealing with the energy flux in a bound electromagnetic field.

  14. The assessment of electromagnetic field radiation exposure for mobile phone users

    OpenAIRE

    Buckus Raimondas; Strukcinskiene Birute; Raistenskis Juozas

    2014-01-01

    Background/Aim. During recent years, the widespread use of mobile phones has resulted in increased human exposure to electromagnetic field radiation and to health risks. Increased usage of mobile phones at the close proximity raises questions and doubts in safety of mobile phone users. The aim of the study was to assess an electromagnetic field radiation exposure for mobile phone users by measuring electromagnetic field strength in different settings at the...

  15. ELECTROMAGNETIC SAFETY OF ELECTRIC TRANSPORT SYSTEMS: MAIN SOURCES AND PARAMETERS OF MAGNETIC FIELDS

    Directory of Open Access Journals (Sweden)

    N. G. Ptitsyna

    2013-03-01

    Full Text Available Magnetic fields produced by electric drive vehicles may break electromagnetic safety. For electromagnetic safety and electromagnetic compatibility knowledge about characteristics and sources of magnetic fields in the electric transport is necessary. The article deals with analysis of available data about magnetic fields in electric cars and comparison with results of our measurements carried out in the other types of electrified transport systems.

  16. Continuity equations for bound electromagnetic field and the electromagnetic energy-momentum tensor

    Energy Technology Data Exchange (ETDEWEB)

    Kholmetskii, A L [Department of Physics, Belarusian State University, 4 Nezavisimosti Avenue, 220030 Minsk (Belarus); Missevitch, O V [Institute for Nuclear Problems, Belarusian State University, 11 Bobruiskaya Street, 220030 Minsk (Belarus); Yarman, T, E-mail: khol123@yahoo.com [Department of Engineering, Okan University, Akfirat, Istanbul, Turkey and Savronik, Eskisehir (Turkey)

    2011-05-01

    We analyze the application of the Poynting theorem to the bound (velocity-dependent) electromagnetic (EM) field and show that an often-used arbitrary elimination of the term of self-interaction in the product j{center_dot}E (where j is the current density and E the electric field) represents, in general, an illegitimate operation, which leads to incorrect physical consequences. We propose correct ways of eliminating the terms of self-interaction from the Poynting theorem to transform it into the form that is convenient for problems with bound EM field, which yield the continuity equations for the proper EM energy density, the interaction part of EM energy density and the total EM energy density of bound fields, respectively. These equations indicate the incompleteness of the common EM energy-momentum tensor, and in our analysis, we find a missed term in its structure, which makes its trace non-vanished. Some implications of these results are discussed, in particular, in view of the notion of EM mass of charged particles.

  17. Covariant Treatment of Neutrino Spin (Flavour) Conversion in Matter under the Influence of Electromagnetic Fields

    OpenAIRE

    Dvornikov, M. S.; Egorov, A M; Lobanov, A. E.; Studenikin, A. I.

    2001-01-01

    Within the recently proposed Lorentz invariant formalism for description of neutrino spin evolution in presence of an arbitrary electromagnetic fields effects of matter motion and polarization are considered.

  18. Methods of evaluating human exposure to electromagnetic fields radiated from operating base stations in Korea.

    Science.gov (United States)

    Kim, Byung Chan; Choi, Hyung-Do; Park, Seong-Ook

    2008-10-01

    This article presents measurement methods used to determine the human exposure to electromagnetic fields radiated from operating base stations. In Korea, when evaluating the human exposure to electromagnetic fields from operating base stations, the measurement procedure is different between the following cases: in situ measurement and electromagnetic environment measurement. When performing an in situ measurement, compliance with human exposure limits is determined by the spatially averaged field value obtained within the space occupied by humans at one arbitrary position, but when performing an electromagnetic environment measurement, it is determined by the maximum value at the highest field position selected from several places.

  19. Electromagnetic field generated by a charge moving along a helical orbit inside a dielectric cylinder

    OpenAIRE

    Saharian, A. A.; Kotanjyan, A.S.; Grigoryan, M. L.

    2006-01-01

    The electromagnetic field generated by a charged particle moving along a helical orbit inside a dielectric cylinder immersed into a homogeneous medium is investigated. Expressions are derived for the electromagnetic potentials, electric and magnetic fields in the region inside the cylinder. The parts corresponding to the radiation field are separated. The radiation intensity on the lowest azimuthal mode is studied.

  20. Probing intergalactic magnetic fields with simulations of electromagnetic cascades

    Energy Technology Data Exchange (ETDEWEB)

    Alves Batista, Rafael [Oxford Univ. (United Kingdom). Dept. of Physics and Astrophysics; Saveliev, Andrey [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Russian Academy of Sciences, Moscow (Russian Federation). Keldysh Inst. of Applied Mathematics; Sigl, Guenter [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Vachaspati, Tanmay [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics

    2016-12-15

    We determine the effect of intergalactic magnetic fields on the distribution of high energy gamma rays by performing three-dimensional Monte Carlo simulations of the development of gamma-ray-induced electromagnetic cascades in the magnetized intergalactic medium. We employ the so-called ''Large Sphere Observer'' method to efficiently simulate blazar gamma ray halos. We study magnetic fields with a Batchelor spectrum and with maximal left- and right-handed helicities. We also consider the case of sources whose jets are tilted with respect to the line of sight. We verify the formation of extended gamma ray halos around the source direction, and observe spiral-like patterns if the magnetic field is helical. We apply the Q-statistics to the simulated halos to extract their spiral nature and also propose an alternative method, the S-statistics. Both methods provide a quantative way to infer the helicity of the intervening magnetic fields from the morphology of individual blazar halos for magnetic field strengths B>or similar 10{sup -15} G and magnetic coherence lengths L{sub c}>or similar 100 Mpc. We show that the S-statistics has a better performance than the Q-statistics when assessing magnetic helicity from the simulated halos.

  1. An efficient explicit marching on in time solver for magnetic field volume integral equation

    KAUST Repository

    Sayed, Sadeed Bin

    2015-07-25

    An efficient explicit marching on in time (MOT) scheme for solving the magnetic field volume integral equation is proposed. The MOT system is cast in the form of an ordinary differential equation and is integrated in time using a PE(CE)m multistep scheme. At each time step, a system with a Gram matrix is solved for the predicted/corrected field expansion coefficients. Depending on the type of spatial testing scheme Gram matrix is sparse or consists of blocks with only diagonal entries regardless of the time step size. Consequently, the resulting MOT scheme is more efficient than its implicit counterparts, which call for inversion of fuller matrix system at lower frequencies. Numerical results, which demonstrate the efficiency, accuracy, and stability of the proposed MOT scheme, are presented.

  2. An explicit marching on-in-time solver for the time domain volume magnetic field integral equation

    KAUST Repository

    Sayed, Sadeed Bin

    2014-07-01

    Transient scattering from inhomogeneous dielectric objects can be modeled using time domain volume integral equations (TDVIEs). TDVIEs are oftentimes solved using marching on-in-time (MOT) techniques. Classical MOT-TDVIE solvers expand the field induced on the scatterer using local spatio-temporal basis functions. Inserting this expansion into the TDVIE and testing the resulting equation in space and time yields a system of equations that is solved by time marching. Depending on the type of the basis and testing functions and the time step, the time marching scheme can be implicit (N. T. Gres, et al., Radio Sci., 36(3), 379-386, 2001) or explicit (A. Al-Jarro, et al., IEEE Trans. Antennas Propag., 60(11), 5203-5214, 2012). Implicit MOT schemes are known to be more stable and accurate. However, under low-frequency excitation, i.e., when the time step size is large, they call for inversion of a full matrix system at very time step.

  3. GPU accelerated FDTD solver and its application in MRI.

    Science.gov (United States)

    Chi, J; Liu, F; Jin, J; Mason, D G; Crozier, S

    2010-01-01

    The finite difference time domain (FDTD) method is a popular technique for computational electromagnetics (CEM). The large computational power often required, however, has been a limiting factor for its applications. In this paper, we will present a graphics processing unit (GPU)-based parallel FDTD solver and its successful application to the investigation of a novel B1 shimming scheme for high-field magnetic resonance imaging (MRI). The optimized shimming scheme exhibits considerably improved transmit B(1) profiles. The GPU implementation dramatically shortened the runtime of FDTD simulation of electromagnetic field compared with its CPU counterpart. The acceleration in runtime has made such investigation possible, and will pave the way for other studies of large-scale computational electromagnetic problems in modern MRI which were previously impractical.

  4. Motionally-induced electromagnetic fields generated by idealized ocean currents

    Science.gov (United States)

    Tyler, R. H.; Mysak, L. A.

    Using the induction equation, we investigate the generation of electromagnetic fields by the motional electromagnetic induction due to ocean currents. In this paper, solutions are presented for a linear induction equation for the magnetic flux density vector which contains prescribed time-independent ocean current and conductivity fields. Once the magnetic flux density is known, the electric field and electric current density are easily obtained by differentiation. Solutions are given for several examples of idealized flow which include: 1) Vertically and horizontally sheared plane-parallel flow with depth-dependent conductivity; 2) A simple Stommel circulation gyre; and 3) Symmetric gyres. The results indicate that typical ocean current features induce magnetic fields with magnitudes reaching 100's of nT within the water and about 1-10 outside of the water. For the case of a field of gyres, the ocean-induced magnetic fields decay away from the ocean on spatial scales set by the horizontal scale of the ocean feature. At the altitudes of magnetic field satellite surveys, ocean-induced magnetic fields may retain values of a few nT, which are strong enough to be detected. Thus it is concluded that satellite observations of the earth's main magnetic field and, in particular, the observed temporal variations, could be affected by the ocean circulation. Summary and discussion In Section 3, we found exact solutions to the induction equation for idealized flows. The results gave magnitudes of about tens to hundreds of nT for the magnetic fields bH, about 10-5 V/m for the electric fields E, and about 10-5 A/m2 for the electric current density J induced by the ocean currents. These figures are in general agreement with the calculations of Lilley et al. (1993). In Section 4.2 we obtained solutions for the magnetic field above the ocean surface for the case of a Stommel gyre and a field of symmetric gyres. It was found in the last case that ocean gyres with a total transport

  5. Effect of 910-MHz Electromagnetic Field on Rat Bone Marrow

    Directory of Open Access Journals (Sweden)

    George Demsia

    2004-01-01

    Full Text Available Aiming to investigate the possibility of electromagnetic fields (EMF developed by nonionizing radiation to be a noxious agent capable of inducing genotoxicity to humans, in the current study we have investigated the effect of 910-MHz EMF in rat bone marrow. Rats were exposed daily for 2 h over a period of 30 consecutive days. Studying bone marrow smears from EMF-exposed and sham-exposed animals, we observed an almost threefold increase of micronuclei (MN in polychromatic erythrocytes (PCEs after EMF exposure. An induction of MN was also observed in polymorphonuclear cells. The induction of MN in female rats was less than that in male rats. The results indicate that 910-MHz EMF could be considered as a noxious agent capable of producing genotoxic effects.

  6. Could Radiotherapy Effectiveness Be Enhanced by Electromagnetic Field Treatment?

    Directory of Open Access Journals (Sweden)

    Núñez María Isabel

    2013-07-01

    Full Text Available One of the main goals in radiobiology research is to enhance radiotherapy effectiveness without provoking any increase in toxicity. In this context, it has been proposed that electromagnetic fields (EMFs, known to be modulators of proliferation rate, enhancers of apoptosis and inductors of genotoxicity, might control tumor recruitment and, thus, provide therapeutic benefits. Scientific evidence shows that the effects of ionizing radiation on cellular compartments and functions are strengthened by EMF. Although little is known about the potential role of EMFs in radiotherapy (RT, the radiosensitizing effect of EMFs described in the literature could support their use to improve radiation effectiveness. Thus, we hypothesized that EMF exposure might enhance the ionizing radiation effect on tumor cells, improving the effects of RT. The aim of this paper is to review reports of the effects of EMFs in biological systems and their potential therapeutic benefits in radiotherapy.

  7. Electromagnetic fields emitted by fluorescent and compact fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, C.; Sebastiao, D.; Ladeira, D.; Carpinteiro, G.; Antunes, M.; Correia, L.M.; Fernandes, C. [Instituto de Telecomunicacoes, Instituto Superior Tecnico, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal)

    2009-05-15

    In the scope of the monIT Project, it was found that fluorescent and compact fluorescent lamps are also important sources of radiation. More than increasing electromagnetic field (EMF) levels in a particular environment, the radiated EMFs from ballasts may cause interference in other devices. Two different lamps are analysed, both in terms of their radiated frequency spectrum and of their compliance with European EMF recommended exposure levels. As expected, the analysis of results shows that, in the immediate vicinity of a lamp, EMF levels radiated by lighting devices depend on the lamp power. Finally, one can conclude that EMFs radiated from both lamps are in compliance with the EMF reference levels. (author)

  8. Could Radiotherapy Effectiveness Be Enhanced by Electromagnetic Field Treatment?

    Science.gov (United States)

    Francisco, Artacho-Cordón; del Mar, Salinas-Asensio María; Irene, Calvente; Sandra, Ríos-Arrabal; Josefa, León; Elisa, Román-Marinetto; Nicolás, Olea; Isabel, Núñez María

    2013-01-01

    One of the main goals in radiobiology research is to enhance radiotherapy effectiveness without provoking any increase in toxicity. In this context, it has been proposed that electromagnetic fields (EMFs), known to be modulators of proliferation rate, enhancers of apoptosis and inductors of genotoxicity, might control tumor recruitment and, thus, provide therapeutic benefits. Scientific evidence shows that the effects of ionizing radiation on cellular compartments and functions are strengthened by EMF. Although little is known about the potential role of EMFs in radiotherapy (RT), the radiosensitizing effect of EMFs described in the literature could support their use to improve radiation effectiveness. Thus, we hypothesized that EMF exposure might enhance the ionizing radiation effect on tumor cells, improving the effects of RT. The aim of this paper is to review reports of the effects of EMFs in biological systems and their potential therapeutic benefits in radiotherapy. PMID:23867611

  9. Exposure to power-frequency electromagnetic fields in Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Skotte, J.H.

    1994-01-01

    The purpose of the study was to assess exposure to power-frequency electromagnetic fields in various groups with normal or high exposure in occupational and residential environments. Exposure to power-frequency (50 Hz) electric and magnetic fields was measured for 301 volunteers (396 measurements) in periods of 24 h in both occupational and residential environments. The study included electrical utility workers (generation, transmission, distribution, substation), office and industrial workers, and people living near high-power transmission lines. Electric and magnetic fields were measured with personal dosemeters, and the mean values were calculated for work and nonwork periods. The work-period magnetic field exposure, as the geometric mean of the distribution of the work-period means. for a group of selected industrial workers with high exposure was 6 [geometric standard deviation (GSD) 4.6] [mu]T. The exposure level was 0.10 (GSD 2.4) [mu]T for 'normal' industrial workers and 0.09 (GSD 1.8) [mu]T for office workers. For electrical utility workers the corresponding values were 0.72 (GSD 2.5) [mu]T for substation workers. 0.52 (GSD 4.2) [mu]T for generation workers. 0.36 (GSD 3.5) [mu]T for transmission workers, and 0.15 (GSD 2.9) [mu]T for distribution workers. The magnetic field exposure in normal residences was 0.04 (GSD 2.1) [mu]T, and in residences near high-power lines it was 0.29 (GSD 2.8) [mu]T. Corresponding results on exposure to electric fields are given in the study. All of the measurements of exposure to electric and magnetic fields were below the values normally used as guidelines

  10. Exposure to power-frequency electromagnetic fields in Denmark.

    Science.gov (United States)

    Skotte, J H

    1994-04-01

    The purpose of the study was to assess exposure to power-frequency electromagnetic fields in various groups with normal or high exposure in occupational and residential environments. Exposure to power-frequency (50 Hz) electric and magnetic fields was measured for 301 volunteers (396 measurements) in periods of 24 h in both occupational and residential environments. The study included electrical utility workers (generation, transmission, distribution, substation), office and industrial workers, and people living near high-power transmission lines. Electric and magnetic fields were measured with personal dosemeters, and the mean values were calculated for work and nonwork periods. The work-period magnetic field exposure, as the geometric mean of the distribution of the work-period means, for a group of selected industrial workers with high exposure was 6 [geometric standard deviation (GSD) 4.6] muT. The exposure level was 0.10 (GSD 2.4) muT for "normal" industrial workers and 0.09 (GSD 1.8) muT for office workers. For electrical utility workers the corresponding values were 0.72 (GSD 2.5) muT for substation workers, 0.52 (GSD 4.2) muT for generation workers, 0.36 (GSD 3.5) muT for transmission workers, and 0.15 (GSD 2.9) muT for distribution workers. The magnetic field exposure in normal residences was 0.04 (GSD 2.1) muT, and in residences near high-power lines it was 0.29 (GSD 2.8)muT. Corresponding results on exposure to electric fields are given in the study. All of the measurements of exposure to electric and magnetic fields were below the values normally used as guidelines.

  11. High Frequency Electromagnetic Field Induces Lipocalin 2 Expression in

    Directory of Open Access Journals (Sweden)

    Amaneh Mohammadi Roushandeh

    2010-06-01

    Full Text Available Objective(sNeutrophil gelatinase-associated lipocalin (NGAL/Lcn2, comprise a group of small extracellular proteins with a common β-sheet-dominated 3-dimensional structure. In the past, it was assumed that the predominant role of lipocalin was acting as transport proteins. Recently it has been found that oxidative stress induces Lcn2 expression. It has been also proved that electromagnetic field (EMF produces reactive oxygen species (ROS in different tissues. Expression of Lcn2 following exposure to electromagnetic field has been investigated in this study. Materials and MethodsBalb/c mice (8 weeks old were exposed to 3 mT, 50 HZ EMF for 2 months, 4 hr/day. Afterwards, the mice were sacrificed by cervical dislocation and livers were removed. The liver specimens were stained with Haematoxylin- Eosin (H&E and analyzed under an optical microscope. Total RNA was extracted from liver and reverse transcription was performed by SuperScript III reverse transcriptase with 1 µg of total RNA. Assessment of Lcn2 expression was performed by semiquantitative and real time- PCR.ResultsThe light microscopic studies revealed that the number of lymphocyte cells was increased compared to control and dilation of sinosoids was observed in the liver. Lcn2 was up-regulated in the mice exposed to EMF both in mRNA and protein levels.ConclusionTo the extent of our knowledge, this is the first report dealing with up-regulation of Lcn2 in liver after exposure to EMF. The up-regulation might be a compensatory response that involves cell defense pathways and protective effects against ROS. However, further and complementary studies are required in this regards.

  12. Electromagnetic interference with cardiac pacemakers and implantable cardioverter-defibrillators from low-frequency electromagnetic fields in vivo.

    Science.gov (United States)

    Tiikkaja, Maria; Aro, Aapo L; Alanko, Tommi; Lindholm, Harri; Sistonen, Heli; Hartikainen, Juha E K; Toivonen, Lauri; Juutilainen, Jukka; Hietanen, Maila

    2013-03-01

    Electromagnetic interference (EMI) can pose a danger to workers with pacemakers and implantable cardioverter-defibrillators (ICDs). At some workplaces electromagnetic fields are high enough to potentially inflict EMI. The purpose of this in vivo study was to evaluate the susceptibility of pacemakers and ICDs to external electromagnetic fields. Eleven volunteers with a pacemaker and 13 with an ICD were exposed to sine, pulse, ramp, and square waveform magnetic fields with frequencies of 2-200 Hz using Helmholtz coil. The magnetic field flux densities varied to 300 µT. We also tested the occurrence of EMI from an electronic article surveillance (EAS) gate, an induction cooktop, and a metal inert gas (MIG) welding machine. All pacemakers were tested with bipolar settings and three of them also with unipolar sensing configurations. None of the bipolar pacemakers or ICDs tested experienced interference in any of the exposure situations. The three pacemakers with unipolar settings were affected by the highest fields of the Helmholtz coil, and one of them also by the EAS gate and the welding cable. The induction cooktop did not interfere with any of the unipolarly programmed pacemakers. Magnetic fields with intensities as high as those used in this study are rare even in industrial working environments. In most cases, employees can return to work after implantation of a bipolar pacemaker or an ICD, after an appropriate risk assessment. Pacemakers programmed to unipolar configurations can cause danger to their users in environments with high electromagnetic fields, and should be avoided, if possible.

  13. Electromagnetic Field Detector Circuit for Low- Frequency Energy Applications

    Directory of Open Access Journals (Sweden)

    M.M. Bait-Suwailam

    2015-06-01

    Full Text Available This study details an electromagnetic (EM field radiation detector system that was developed for near-field low-frequency energy applications. The prototype constitutes the use of a dual-band monopole antenna system as a probe along with a detecting circuit. Furthermore, the prototype was equipped with a qualitative EM radiation strength display unit at its output stage. For proof of concept, the detecting probe was implemented on a printed-circuit board. Both numerical simulations were based on PSpice software (Cadence Design Systems, Inc., San Jose, California, USA and measurements are presented and discussed. The EM field detector aimed to sense any potential sources of EM radiation from mobile phone units as well as WiFi access points, simultaneously, which is accomplished with the use of the dual-band antenna system. Such a sensitive detector has useful application as a stand-alone monitoring probe for troubleshooting as well as to identify sources of EM radiation interference threats for industrial high-speed electronic devices. Additionally, such a sensor is a potentially useful tool for site testing and scanning for optimal locations of base station masks for telecommunication service providers.  Other prototypes are also presented to illustrate the usefulness of such detectors in some of the aforementioned applications.

  14. Future Prospects of UHE Neutrino Detection with Electromagnetic Fields

    Science.gov (United States)

    Hanson, Jordan C.

    In recent years, the field of ultra-high energy (≥1 PeV) neutrino astronomy has begun to develop. Both Cerenkov photon detectors and radio detectors have been constructed, and an extraterrestrial signal has finally been observed near 1 PeV. Both particle physics and astrophysics drive the development of this field. Ultra-high energy (UHE) neutrinos generated by the GZK process could reveal the origin of cosmic rays, by pointing to the source. A sample of neutrino interactions with terrestrial matter at center-of-mass energies ≥10 TeV also presents opportunities to quantify the neutrino cross-section and flavor physics at previously unreachable energies. Finally, astrophysical phenomena with particle energies greater than the electro-weak scale and redshift z ≥ 0.1 will never be observed until the field of UHE neutrino astronomy matures. Thus, Askaryan effect-based radio detectors are becoming increasingly important, and the Antarctic Ross Ice Shelf Antenna Neutrino Array (ARIANNA) is a detector designed in this fashion. The electromagnetic signal in detectors such as ARIANNA will be described, along with various effects that modify it.

  15. Current Understanding of the Health Effects of Electromagnetic Fields.

    Science.gov (United States)

    Miah, Tayaba; Kamat, Deepak

    2017-04-01

    There has been an exponential increase in the use of electronic devices over the past few decades. This has led to increased exposure to electromagnetic fields (EMF). Electric fields result from differences in voltage, whereas magnetic fields result from the flow of electric current. Higher-frequency waves of EMF have more energy than lower-frequency waves, and thus generally tend to be more harmful. An EMF activates cellular stress response and also causes breaks in DNA strands. There are many methodological barriers to effectively measuring the associations of EMF and childhood cancers. The consensus from multiple studies is that there is no causal role of extremely low-frequency EMFs in childhood cancers, including brain cancer. A recent study showed a link between EMF radiation and the development of malignant tumors in rats. In light of that study, the American Academy of Pediatrics set out new recommendations to decrease the adverse effects of cellphone exposure on children. [Pediatr Ann. 2017;46(4):e172-e174.]. Copyright 2017, SLACK Incorporated.

  16. Occupational exposure to electromagnetic fields and sex-differential risk of uveal melanoma

    DEFF Research Database (Denmark)

    Behrens, Thomas Flensted; Lynge, Elsebeth; Cree, Ian

    2010-01-01

    The association between occupational exposure to electromagnetic fields (EMF) and the risk of uveal melanoma was investigated in a case-control study in nine European countries.......The association between occupational exposure to electromagnetic fields (EMF) and the risk of uveal melanoma was investigated in a case-control study in nine European countries....

  17. Sensitivity of the near-surface vertical electric field land Controlled-Source Electromagnetic monitoring

    NARCIS (Netherlands)

    Schaller, A.M.; Hunziker, J.W.; Streich, R.; Drijkoningen, G.G.

    2014-01-01

    We investigate potential benefits of measuring the vertical electric field component in addition to the routinely measured horizontal electric field components in onshore time-lapse controlled-source electromagnetics. Synthetic electromagnetic data based on a model of the Schoonebeek onshore oil

  18. Sensitivity of the near-surface vertical electric field land Controlled-Source Electromagnetic monitoring

    NARCIS (Netherlands)

    Schaller, A.M.; Hunziker, J.W.; Streich, R.; Drijkoningen, G.G.

    We investigate potential benefits of measuring the vertical electric field component in addition to the routinely measured horizontal electric field components in onshore time-lapse controlled-source electromagnetics. Synthetic electromagnetic data based on a model of the Schoonebeek onshore oil

  19. Modeling of interactions of electromagnetic fields with human bodies

    Science.gov (United States)

    Caputa, Krzysztof

    Interactions of electromagnetic fields with the human body have been a subject of scientific interest and public concern. In recent years, issues in power line field effects and those of wireless telephones have been in the forefront of research. Engineering research compliments biological investigations by quantifying the induced fields in biological bodies due to exposure to external fields. The research presented in this thesis aims at providing reliable tools, and addressing some of the unresolved issues related to interactions with the human body of power line fields and fields produced by handheld wireless telephones. The research comprises two areas, namely development of versatile models of the human body and their visualisation, and verification and application of numerical codes to solve selected problems of interest. The models of the human body, which are based on the magnetic resonance scans of the body, are unique and differ considerably from other models currently available. With the aid of computer software developed, the models can be arranged to different postures, and medical devices can be accurately placed inside them. A previously developed code for modeling interactions of power line fields with biological bodies has been verified by rigorous, quantitative inter-laboratory comparison for two human body models. This code has been employed to model electromagnetic interference (EMI) of the magnetic field with implanted cardiac pacemakers. In this case, the correct placement and representation of the pacemaker leads are critical, as simplified computations have been shown to result in significant errors. In modeling interactions of wireless communication devices, the finite difference time domain technique (FDTD) has become a de facto standard. The previously developed code has been verified by comparison with the analytical solution for a conductive sphere. While previously researchers limited their verifications to principal axes of the sphere

  20. Exposure to electromagnetic fields aboard high-speed electric multiple unit trains.

    Science.gov (United States)

    Niu, D; Zhu, F; Qiu, R; Niu, Q

    2016-01-01

    High-speed electric multiple unit (EMU) trains generate high-frequency electric fields, low-frequency magnetic fields, and high-frequency wideband electromagnetic emissions when running. Potential human health concerns arise because the electromagnetic disturbances are transmitted mainly into the car body from windows, and from there to passengers and train staff. The transmission amount and amplitude distribution characteristics that dominate electromagnetic field emission need to be studied, and the exposure level of electromagnetic field emission to humans should be measured. We conducted a series of tests of the on board electromagnetic field distribution on several high-speed railway lines. While results showed that exposure was within permitted levels, the possibility of long-term health effects should be investigated.

  1. Assessment of occupational exposure to radio frequency electromagnetic fields

    Directory of Open Access Journals (Sweden)

    Halina Aniołczyk

    2015-06-01

    Full Text Available Background: European Union Directive 2013/35/UE provides for the implementation of EU regulations into national legislation. Our aim is to assess actual health hazards from radiofrequency electromagnetic field (RF EMF (range: 100 kHz – 300 GHz and indicate workplaces with the highest risk to employee health. Material and Methods: Data from measurements of RF EMF performed by the Laboratory of Electromagnetic Hazards in Nofer Institute of Occupational Medicine (Łódź, Poland were analyzed. The analysis covered the results of electric field intensity (E for over 450 selected items. The ranges of protection zones and the extent to which maximum admissible intensity (MAI values were also analyzed. The determinations and measurements of EMF in the work environment met the requirements of Polish Standard, while Polish regulations on the MAI values were used as the criterion for the assessment of the exposure. Results: The highest values of E field intensity at workplaces were measured for: electrosurgery, to 400 V/m, and short-wave diathermy units, to 220 V/m, dielectric welders to 240 V/m, within the FM radio antenna systems, to 180 V/m. The widest protection zones were noted for prototype research instruments, short-wave diathermy units, and dielectric welders. The most excessive (up to 12-fold MAI values were recorded for dielectric welders, short-wave diathermy units (up to 11-fold and microwave diathermy units (up to 8-fold. Conclusions: Our results have confirmed the high RF EMF values for physiotherapists, operators of dielectric welders, and mast maintenance workers in radio communication facilities (especially radio and TV broadcasting stations. Med Pr 2015;66(2:199–212

  2. Hyperthermic effect of magnetic nanoparticles under electromagnetic field

    Directory of Open Access Journals (Sweden)

    Giovanni Baldi

    2009-06-01

    Full Text Available Magnetic nanoparticles have attracted increasingly attention due to their potential applications in many industrial fields, even extending their use in biomedical applications. In the latter contest the main features of magnetic nanoparticles are the possibility to be driven by external magnetic fields, the ability to pass through capillaries without occluding them and to absorb and convert electromagnetic radiation in to heat (Magnetic Fluid Hyperthermia. The main challenges of the current works on hyperthermia deal with the achievement of highly efficiency magnetic nanoparticles, the surface grafting with ligands able to facilitate their specific internalisation in tumour cells and the design of stealth nanocomposites able to circulate in the blood compartment for a long time. This article presents the synthesis of cobalt ferrite nanoparticles dispersed in diethylene glycol via the so called polyol strategy and the crystal size control through successive synthesis steps. Preliminary heat dissipation evaluations on the prepared samples were carried out and the question of how particles sizes affect their magnetic and hyperthermic properties was addressed as well. Furthermore we will present how surface chemistry can be modified in order to change the dispersity of the product without affecting magnetic and hyperthermic properties.

  3. Electromagnetic field generation by ATP-induced reverse electron transfer.

    Science.gov (United States)

    Steele, Richard H

    2003-03-01

    This paper describes a mechanism to explain low-level light emission in biology. A biological analog of the electrical circuitry, modeled on the parallel plate capacitor, traversed by a helical structure, required to generate electromagnetic radiation in the optical spectral range, is described. The charge carrier required for the emissions is determined to be an accelerating electron driven by an ATP-induced reverse electron transfer. The radial velocity component, the emission trajectory, of the moving charges traversing helical protein structures in a cyclotron-type mechanism is proposed to be imposed by the ferromagnetic field components of the iron in the iron-sulfur proteins. The redox systems NADH, riboflavin, and chlorophyll were examined with their long-wavelength absorption maxima determining the energetic parameters for the calculations. Potentials calculated from the axial velocity components for the riboflavin and NADH systems were found to equal the standard redox potentials of these systems as measured electrochemically and enzymatically. The mechanics for the three systems determined the magnetic moments, the angular momenta, and the orbital magnetic fluxes to be adiabatic invariant parameters. The De Broglie dual wave-particle equation, the fundamental equation of wave mechanics, and the key idea of quantum mechanics, establishes the wavelengths for accelerating electrons which, divided into a given radial velocity, gives its respective emission frequency. Electrons propelled through helical structures, traversed by biologically available electric and magnetic fields, make accessible to the internal environment the optical spectral frequency range that the solar spectrum provides to the external environment.

  4. In vitro exposure of human chondrocytes to pulsed electromagnetic fields

    Directory of Open Access Journals (Sweden)

    V Nicolin

    2009-08-01

    Full Text Available The effect of pulsed electromagnetic fields (PEMFs on the proliferation and survival of matrix-induced autologous chondrocyte implantation (MACI®-derived cells was studied to ascertain the healing potential of PEMFs. MACI-derived cells were taken from cartilage biopsies 6 months after surgery and cultured. No dedifferentiation towards the fibroblastic phenotype occurred, indicating the success of the surgical implantation. The MACI-derived cultured chondrocytes were exposed to 12 h/day (short term or 4 h/day (long term PEMFs exposure (magnetic field intensity, 2 mT; frequency, 75 Hz and proliferation rate determined by flow cytometric analysis. The PEMFs exposure elicited a significant increase of cell number in the SG2M cell cycle phase. Moreover, cells isolated from MACI® scaffolds showed the presence of collagen type II, a typical marker of chondrocyte functionality. The results show that MACI® membranes represent an optimal bioengineering device to support chondrocyte growth and proliferation in surgical implants. The surgical implant of MACI® combined with physiotherapy is suggested as a promising approach for a faster and safer treatment of cartilage traumatic lesions.

  5. Electromagnetically induced transparency resonances inverted in magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Sargsyan, A.; Sarkisyan, D., E-mail: davsark@yahoo.com, E-mail: david@ipr.sci.am [National Academy of Sciences of Armenia, Institute for Physical Research (Armenia); Pashayan-Leroy, Y.; Leroy, C. [Université de Bourgogne-Dijon, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR CNRS (France); Cartaleva, S. [Bulgarian Academy of Sciences, Institute of Electronics (Bulgaria); Wilson-Gordon, A. D. [Bar-Ilan University Ramat Gan, Department of Chemistry (Israel); Auzinsh, M. [University of Latvia, Department of Physics (Latvia)

    2015-12-15

    The phenomenon of electromagnetically induced transparency (EIT) is investigated in a Λ-system of the {sup 87}Rb D{sub 1} line in an external transverse magnetic field. Two spectroscopic cells having strongly different values of the relaxation rates γ{sub rel} are used: an Rb cell with antirelaxation coating (L ∼ 1 cm) and an Rb nanometric- thin cell (nanocell) with a thickness of the atomic vapor column L = 795 nm. For the EIT in the nanocell, we have the usual EIT resonances characterized by a reduction in the absorption (dark resonance (DR)), whereas for the EIT in the Rb cell with an antirelaxation coating, the resonances demonstrate an increase in the absorption (bright resonances (BR)). We suppose that such an unusual behavior of the EIT resonances (i.e., the reversal of the sign from DR to BR) is caused by the influence of an alignment process. The influence of alignment strongly depends on the configuration of the coupling and probe frequencies as well as on the configuration of the magnetic field.

  6. Convective heat transfer in engine coolers influenced by electromagnetic fields

    Science.gov (United States)

    Karcher, C.; Kühndel, J.

    2017-08-01

    In engine coolers of off-highway vehicles, convective heat transfer at the coolant side limits both efficiency and performance density of the apparatus. Here, due to restrictions in construction and design, backwater areas and stagnation regions cannot be avoided. Those unwanted changes in flow characteristics are mainly triggered by flow deflections and sudden cross-sectional expansions. In application, mixtures of water and glysantine are used as appropriate coolants. Such coolants typically show an electrical conductivity of a few S/m. Coolant flow and convective heat transfer can then be controlled using Lorentz forces. These body forces are generated within the conducting fluid by the interactions of an electrical current density and a localized magnetic field, both of which are externally superimposed. In future application, this could be achieved by inserting electrodes in the cooler wall and a corresponding arrangement of permanent magnets. In this paper we perform numerical simulations of such magnetohydrodynamic flow in three model geometries that frequently appear in engine cooling applications: Carnot-Borda diffusor, 90° bend, and 180° bend. The simulations are carried out using the software package ANSYS Fluent. The present study demonstrates that, depending on the electromagnetic interaction parameter and the specific geometric arrangement of electrodes and magnetic field, Lorentz forces are suitable to break up eddy waters and separation zones and thus significantly increase convective heat transfer in these areas. Furthermore, the results show that hydraulic pressure losses can be reduced due to the pumping action of the Lorentz forces.

  7. Measurement of Electromagnetic Fields Emitted from Some Medical Devices

    Directory of Open Access Journals (Sweden)

    Shaker Faisel

    2015-02-01

    Full Text Available     New medical devices such as surgery devices, physiotherapy devices, cosmetological devices and Magnetic Resonance Imaging (MRI systems generate a complex electromagnetic fields, so they consider as a potential   hazard for medical personnel during surgical procedures. The aim of this research is to detect the EMFs emitted from medical devices and determine the safety ranges from these devices which emit EMF radiations in order to protect Medical staff from its risks. The research has been performed in two parts, numerical calculation and practical measurement. Practical measurements are done in Dijlah hospital at Tikrit city. Obtaining results shows that the practical measurements are consistent with the mathematical calculation results. Comparison of these results with the safety standard guideline limits shows that they   are within the acceptable exposure limits recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP and that means there is no health risk from exposure to these fields if the exposure is for a short and not continued periods and lay within the acceptable limits.    

  8. Adaptive framework for uncertainty analysis in electromagnetic field measurements.

    Science.gov (United States)

    Prieto, Javier; Alonso, Alonso A; de la Rosa, Ramón; Carrera, Albano

    2015-04-01

    Misinterpretation of uncertainty in the measurement of the electromagnetic field (EMF) strength may lead to an underestimation of exposure risk or an overestimation of required measurements. The Guide to the Expression of Uncertainty in Measurement (GUM) has internationally been adopted as a de facto standard for uncertainty assessment. However, analyses under such an approach commonly assume unrealistic static models or neglect relevant prior information, resulting in non-robust uncertainties. This study proposes a principled and systematic framework for uncertainty analysis that fuses information from current measurements and prior knowledge. Such a framework dynamically adapts to data by exploiting a likelihood function based on kernel mixtures and incorporates flexible choices of prior information by applying importance sampling. The validity of the proposed techniques is assessed from measurements performed with a broadband radiation meter and an isotropic field probe. The developed framework significantly outperforms GUM approach, achieving a reduction of 28% in measurement uncertainty. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Reducing electromagnetic field exposure from hydro corridors : staff report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-06-15

    The use and transmission of electricity creates electromagnetic fields (EMF). Electric appliances, building wiring, and electricity transmission lines are common EMF sources in urban areas. Overall levels of EMF in and right next to hydro corridors can be higher than those usually found both indoors and outdoors elsewhere in Toronto. The magnetic component of EMF has been classified as a possible carcinogen by the International Agency for Research on Cancer because of the association between exposures to EMF magnetic fields in the home and childhood leukemia. Given the possible link between the exposure to EMF and an increase in the risk of leukemia in children, finding practical low or no-cost actions to reduce EMF exposures to young children is important. This report made several recommendations on behalf of the Medical Officer of Health. Implementation points and financial impacts were considered. The decision history and issue background were also presented. The report examined daily exposure to EMF; exposure to EMF in hydro corridors; health effects of EMF; risks from exposures to EMF in Toronto; EMF regulations in Canada and other countries; ways to reduce exposures; and benefits of the park and recreational uses of hydro corridors. The report proposed that the city of Toronto continue with a policy of prudent avoidance and take simple steps that would minimize exposures to EMF from hydro corridors for young children. 1 tab.

  10. The influence of strong field vacuum polarization on gravitational-electromagnetic wave interaction

    OpenAIRE

    Forsberg, Mats; Papadopoulos, Demetrios; Brodin, Gert

    2010-01-01

    The interaction between gravitational and electromagnetic waves in the presence of a static magnetic field is studied. The field strength of the static field is allowed to surpass the Schwinger critical field, such that the quantum electrodynamical (QED) effects of vacuum polarization and magnetization are significant. Equations governing the interaction are derived and analyzed. It turns out that the energy conversion from gravitational to electromagnetic waves can be significantly altered d...

  11. [ASSESSMENT OF OCCUPATIONAL EXPOSURE TO RADIO FREQUENCY ELECTROMAGNETIC FIELDS].

    Science.gov (United States)

    Aniołczyk, Halina; Mariańska, Magda; Mamrot, Paweł

    2015-01-01

    European Union Directive 2013/35/UE provides for the implementation of EU regulations into national legislation. Our aim is to assess actual health hazards from radiofrequency eldctromagnetic field (RF EMF) (range: 100 kHz - 300 GHz) and indicate workplaces with the highest risk to employee health. Data from measurements of RF EMF performed by the Laboratory of Electromagnetic Hazards in Nofer Institute of Occupational Medicine (Łódź, Poland) were analyzed. The analysis covered the results of electric field intensity (E) for over 450 selected items. The ranges of protection zones and the extent to which maximum admissible intensity (MAI) values were also analyzed. The determinations and'measurements of EMF in the work environment met the requirements of Polish Standard, while Polish regulations on the MAI values were used as the criterion for the assessment of the exposure. The highest values of E field intensity at workplaces were measured for: electrosurgery, to 400 V/m, and short-wave diathermy units, to 220 V/m, dielectric welders to 240 V/m, within the FM radio antenna systems, to 180 V/m. The widest protection zones were noted for prototype research instruments, short-wave diathermy units, and dielectric welders. The most excessive (up to 12-fold MAI) values were recorded for dielectric welders, short-wave diathermy units (up to 11-fold) and microwave diathermy units (up to 8-fold). Our results have confirmed the high RF EMF values for physiotherapists, operators of dielectric welders, and mast maintenance workers in radio com munication facilities (especially radio and TV broadcasting stations).

  12. Phase-space representation and polarization domains of random electromagnetic fields.

    Science.gov (United States)

    Castaneda, Roman; Betancur, Rafael; Herrera, Jorge; Carrasquilla, Juan

    2008-08-01

    The phase-space representation of stationary random electromagnetic fields is developed by using electromagnetic spatial coherence wavelets. The propagation of the field's power and states of spatial coherence and polarization results from correlations between the components of the field vectors at pairs of points in space. Polarization domains are theoretically predicted as the structure of the field polarization at the observation plane. In addition, the phase-space representation provides a generalization of the Poynting theorem. Theoretical predictions are examined by numerically simulating the Young experiment with electromagnetic waves. The experimental implementation of these results is a current subject of research.

  13. Estimation of the Lithospheric Component Share in the Earth Natural Pulsed Electromagnetic Field Structure

    Science.gov (United States)

    Malyshkov, S. Y.; Gordeev, V. F.; Polyvach, V. I.; Shtalin, S. G.; Pustovalov, K. N.

    2017-04-01

    Article describes the results of the atmosphere and Earth’s crust climatic and ecological parameters integrated monitoring. The estimation is made for lithospheric component share in the Earth natural pulsed electromagnetic field structure. To estimate lithospheric component we performed a round-the-clock monitoring of the Earth natural pulsed electromagnetic field background variations at the experiment location and measured the Earth natural pulsed electromagnetic field under electric shields. Natural materials in a natural environment were used for shielding, specifically lakes with varying parameters of water conductivity. Skin effect was used in the experiment - it is the tendency of electromagnetic waves amplitude to decrease with greater depths in the conductor. Atmospheric and lithospheric component the Earth natural pulsed electromagnetic field data recorded on terrain was compared against the recorded data with atmosphere component decayed by an electric shield. In summary we have demonstrated in the experiment that thunderstorm discharge originating electromagnetic field decay corresponds to the decay calculated using Maxwell equations. In the absence of close lightning strikes the ratio of field intensity recorded on terrain to shielded field intensity is inconsistent with the ratio calculated for atmospheric sources, that confirms there is a lithospheric component present to the Earth natural pulsed electromagnetic field.

  14. Noninvasive electromagnetic fields on keratinocyte growth and migration.

    Science.gov (United States)

    Huo, Ran; Ma, Qianli; Wu, James J; Chin-Nuke, Kayla; Jing, Yuqi; Chen, Juan; Miyar, Maria E; Davis, Stephen C; Li, Jie

    2010-08-01

    Although evidence has shown that very small electrical currents produce a beneficial therapeutic result for wounds, noninvasive electromagnetic field (EMF) therapy has consisted mostly of anecdotal clinical reports, with very few well-controlled laboratory mechanistic studies. In this study, we evaluate the effects and potential mechanisms of a noninvasive EMF device on skin wound repair. The effects of noninvasive EMF on keratinocytes and fibroblasts were assessed via proliferation and incisional wound model migration assays. cDNA microarray and RT-PCR were utilized to assess genetic expression changes in keratinocytes after noninvasive EMF treatment. In vitro analyses with human skin keratinocyte cultures demonstrated that noninvasive EMFs have a strong effect on accelerating keratinocyte migration and a relatively weaker effect on promoting keratinocyte proliferation. The positive effects of noninvasive EMFs on cell migration and proliferation seem keratinocyte-specific without such effects seen on dermal fibroblasts. cDNA microarray and RT-PCR performed revealed increased expression of CRK7 and HOXC8 genes in treated keratinocytes. This study suggests that a noninvasive EMF accelerates wound re-epithelialization through a mechanism of promoting keratinocyte migration and proliferation, possibly due to upregulation of CRK7 and HOXC8 genes. Copyright 2010 Elsevier Inc. All rights reserved.

  15. Effect of extremely low frequency electromagnetic fields on bacterial membrane.

    Science.gov (United States)

    Oncul, Sule; Cuce, Esra M; Aksu, Burak; Inhan Garip, Ayse

    2016-01-01

    The effect of extremely low frequency electromagnetic fields (ELF-EMF) on bacteria has attracted attention due to its potential for beneficial uses. This research aimed to determine the effect of ELF-EMF on bacterial membrane namely the membrane potential, surface potential, hydrophobicity, respiratory activity and growth. Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were subjected to ELF-EMF, 50 Hz, 1 mT for 2 h. Membrane potential was determined by fluorescence spectroscopy with or without EDTA (Ethylenediaminetetraacetic acid) with DisC3(5) (3,3-dipropylthiacarbocyanine iodide), zeta potential measurements were performed by electrophoretic mobility, hydrophobicity of the membrane was measured with MATH (Microbial Adhesion to Hydrocarbons) test, respiratory activity was determined with CTC (5-Cyano-2,3-ditolyl tetrazolium chloride), colony forming unit (CFU) and DAPI (4',6-diamidino-2-phenylindole, dihydrochloride) was used for growth determinations. ELF-EMF caused changes in physicochemical properties of both Gram-positive and Gram-negative bacteria. Hyperpolarization was seen in S. aureus and EDTA-treated E. coli. Surface potential showed a positive shift in S. aureus contrariwise to the negative shift seen in EDTA-untreated E. coli. Respiratory activity increased in both bacteria. A slight decrease in growth was observed. These results show that ELF-EMF affects the crucial physicochemical processes in both Gram-positive and Gram-negative bacteria which need further research.

  16. Electromagnetic fields in neonatal incubators: the reasons for an alert.

    Science.gov (United States)

    Bellieni, Carlo Valerio; Nardi, Valentina; Buonocore, Giuseppe; Di Fabio, Sandra; Pinto, Iole; Verrotti, Alberto

    2017-10-23

    Neonatal incubators are important tools for sick newborns in the first few days of life. Nevertheless, their electric engine, often very close to the newborn's body, emits electromagnetic fields (EMF) to which newborns are exposed. Aim of this paper is to review the available literature on EMF exposure in incubators, and the effects of such exposures on newborns that have been investigated. We carried out a systematic review of studies about EMF emissions produced by incubators, using Medline and Embase databases from 1993 to 2017. We retrieved 15 papers that described the EMF exposure in incubators and their biological effects on babies. EMF levels in incubators appear to be between 2 and 100 mG, depending on the distance of the mattress from the electric engine. In some cases, they exceed this range. These values interfere with melatonin production or with vagal tone. Even caregivers are exposed to high EMF, above 200 mG, when working at close contact with the incubators. EMF have been described as potentially hazardous for human health, and values reported in this review are an alert to prevent babies' and caregivers' exposure when close to the incubators. A precautionary approach should be adopted in future incubator design, to prevent high exposures of newborns in incubators and of caregivers as well.

  17. Exposure to electromagnetic fields from laptop use of "laptop" computers.

    Science.gov (United States)

    Bellieni, C V; Pinto, I; Bogi, A; Zoppetti, N; Andreuccetti, D; Buonocore, G

    2012-01-01

    Portable computers are often used at tight contact with the body and therefore are called "laptop." The authors measured electromagnetic fields (EMFs) laptop computers produce and estimated the induced currents in the body, to assess the safety of laptop computers. The authors evaluated 5 commonly used laptop of different brands. They measured EMF exposure produced and, using validated computerized models, the authors exploited the data of one of the laptop computers (LTCs) to estimate the magnetic flux exposure of the user and of the fetus in the womb, when the laptop is used at close contact with the woman's womb. In the LTCs analyzed, EMF values (range 1.8-6 μT) are within International Commission on Non-Ionizing Radiation (NIR) Protection (ICNIRP) guidelines, but are considerably higher than the values recommended by 2 recent guidelines for computer monitors magnetic field emissions, MPR II (Swedish Board for Technical Accreditation) and TCO (Swedish Confederation of Professional Employees), and those considered risky for tumor development. When close to the body, the laptop induces currents that are within 34.2% to 49.8% ICNIRP recommendations, but not negligible, to the adult's body and to the fetus (in pregnant women). On the contrary, the power supply induces strong intracorporal electric current densities in the fetus and in the adult subject, which are respectively 182-263% and 71-483% higher than ICNIRP 98 basic restriction recommended to prevent adverse health effects. Laptop is paradoxically an improper site for the use of a LTC, which consequently should be renamed to not induce customers towards an improper use.

  18. Vector-based plane-wave spectrum method for the propagation of cylindrical electromagnetic fields.

    Science.gov (United States)

    Shi, S; Prather, D W

    1999-11-01

    We present a vector-based plane-wave spectrum (VPWS) method for efficient propagation of cylindrical electromagnetic fields. In comparison with electromagnetic propagation integrals, the VPWS method significantly reduces time of propagation. Numerical results that illustrate the utility of this method are presented.

  19. Coupled poroelastic waves and electromagnetic fields in layered media : Theory, Modeling, and Interferometric Synthesis

    NARCIS (Netherlands)

    Grobbe, N.

    2016-01-01

    In this thesis, I study coupled poroelastic waves and electromagnetic fields in layered media. The focus is two-fold:
    1. Increase the theoretical and physical understanding of the seismo-electromagnetic phenomenon by analytically-based numerical modeling.
    2. Investigate the potential of

  20. Full Action for an Electromagnetic Field with Electrical and Magnetic Charges

    CERN Document Server

    Serova, S S

    2010-01-01

    The paper offers the full action for an electromagnetic field with electrical and magnetic charges; it is marked, that it is hard to give an accurate formulation of Feynman laws for the calculation of the interaction cross-sections for electrically and magnetically charged particles on the base of offerd action within relativistic quantum field theory, simple partial case of a constant electromagnetic field is considered.

  1. Influence of Electric, Magnetic, and Electromagnetic Fields on the Circadian System: Current Stage of Knowledge

    OpenAIRE

    Lewczuk, Bogdan; Redlarski, Grzegorz; Żak, Arkadiusz; Ziółkowska, Natalia; Przybylska-Gornowicz, Barbara; Krawczuk, Marek

    2014-01-01

    One of the side effects of each electrical device work is the electromagnetic field generated near its workplace. All organisms, including humans, are exposed daily to the influence of different types of this field, characterized by various physical parameters. Therefore, it is important to accurately determine the effects of an electromagnetic field on the physiological and pathological processes occurring in cells, tissues, and organs. Numerous epidemiological and experimental data suggest ...

  2. Rotation invariance of electromagnetic radiation generated by relativistic particles in magnetic fields

    CERN Document Server

    Smolyakov, M N

    2000-01-01

    This paper deals with electromagnetic radiation generated by relativistic particles in arbitrary planar magnetic field (in undulator for example). Magnetic system producing this field is assumed to be planar consisting of permanent magnets. It is shown that there is a special class of magnetic moment rotations in such system while magnetic field is varying but spontaneous radiation spectrum generated by relativistic particles remains the same. This property of electromagnetic radiation can be used in designing new undulators.

  3. Inhomogeneous Bulk Viscous Fluid Universe with Electromagnetic Field and Variable $\\Lambda$-Term

    OpenAIRE

    Pradhan,Anirudh; Rai, Vandana; Jotania, Kanti

    2008-01-01

    Cylindrically symmetric inhomogeneous cosmological model for bulk viscous fluid distribution with electromagnetic field is obtained. The source of the magnetic field is due to an electric current produced along the z-axis. $F_{12}$ is the non-vanishing component of electromagnetic field tensor. To get the deterministic solution, it has been assumed that the expansion $\\theta$ in the model is proportional to the shear $\\sigma$. The values of cosmological constant for these models are found to ...

  4. Ultrastructural Study on Ultra-Low Frequency Electromagnetic Fields and Transfer Factor Effects on Skin Ulcers

    Science.gov (United States)

    Cadena, M. S. Reyes; Chapul, L. Sánchez; Pérez, Javiér; García, M. N. Jiménez; López, M. A. Jiménez; Espíndola, M. E. Sánchez; Perez, R. Paniagua; Hernández, N. A.; Paniagua, G.; Uribe, F.; Nava, J. J. Godina; Segura, M. A. Rodríguez

    2008-08-01

    We determined the effect of 120Hz ultra low frequency electromagnetic field (ELF) on the healing process of skin in 20 Wistar rats distributed in four groups in which chronic dermal ulcers had been produced. The first two groups received a dose of the transfer factor and interferon-beta (IFN-β) every 24 h during 12 days. The third group (positive control) received only electromagnetic field (ELF) sessions, and in the fourth group (negative control), no treatment was applied. The electromagnetic field was applied through a Helmholtz coils; 30 Gauss of intensity. Results shown histological changes that improve the healing process in animals subjected to ELF together with the transfer factor.

  5. Impact of Low Frequency Electromagnetic Field Exposure on the Candida Albicans

    Science.gov (United States)

    Malíková, Ivona; Janoušek, Ladislav; Fantova, Vladyslava; Jíra, Jaroslav; Kříha, Vítĕzslav

    2015-03-01

    Effect of low frequency electromagnetic field on growth of selected microorganism is studied in the article. The diploid fungus that grows both as yeast and filamentous cell was chosen for this research. The theory of ion parametric resonance was taken as the base for studying the influence of electromagnetic field on biological structures. We tested the hypothesis, whether it is possible to observe the change in growth properties of Candida albicans with an AC electromagnetic field tuned to resonance with calcium ions cyclotron frequency.

  6. Fast Poisson Solvers for Self-Consistent Beam-Beam and Space-Charge Field Computation in Multiparticle Tracking Simulations

    CERN Document Server

    Florio, Adrien; Pieloni, Tatiana; CERN. Geneva. ATS Department

    2015-01-01

    We present two different approaches to solve the 2-dimensional electrostatic problem with open boundary conditions to be used in fast tracking codes for beam-beam and space charge simulations in high energy accelerators. We compare a fast multipoles method with a hybrid Poisson solver based on the fast Fourier transform and finite differences in polar coordinates. We show that the latter outperforms the first in terms of execution time and precision, allowing for a reduction of the noise in the tracking simulation. Furthermore the new algorithm is shown to scale linearly on parallel architectures with shared memory. We conclude by effectively replacing the HFMM by the new Poisson solver in the COMBI code.

  7. [Patients' exposure to electromagnetic fields and radon in radon spas].

    Science.gov (United States)

    Politański, Piotr; Olszewski, Jerzy; Mamrot, Paweł; Mariańska, Mlagda; Zmyślony, Marek

    2014-01-01

    Many patients of physiotherapeutic facilities using therapeutic radon are also referred to other treatments involving the use of electromagnetic field (EMF). However, in the light of the theory of EMF influence on free radicals, it is still an open question whether, application of EMF shortly after the radon treatment may alter the biological effects of radon or EMF. The aim of the study was to determine how large is the group of patients exposed to radon and EMF in Poland, and how high is the exposure of these patients to analyzed factors. The results of the study are to be used in the future assessment of the combined effects of radon and EMF in radon spas. Based on the statistical data and interviews held in the major Polish radon spas, the analysis of treatment structure was performed and exposure to radon and EMF was assessed by measuring radon concentrations and characteristic values of exposure to EMF. More than 8000 people per year are subjected to combined exposure to radon and EMF. Significant differences were found between measured radon concentrations (they ranged from approximately 61 kBq/m3 for inhalations with inhaler to only 290 Bq/m3 for graduation towers, p = 0.049) and EMF intensities corresponded to those observed in hazardous and dangerous zones for occupational exposure. The results of the study showed significant differences between radon concentrations during various radon treatments. There is a need to develop clear and universal procedures for the application of radon or radon combined with EMF in radon spas. The effects of patients' exposure to radon, especially combined with EMF need to be further studied.

  8. Household electromagnetic fields and breast cancer in elderly women.

    Science.gov (United States)

    Beniashvili, Djemal; Avinoach, Ilana; Baazov, David; Zusman, Itshak

    2005-01-01

    The relationship between the rate of household low-frequency electromagnetic fields (EMF) and incidences of mammary tumors was studied in 1290 clinical case-records of female patients aged 60 and more over a period of 26 years, based on the materials of the Edith Wolfson Medical Center, Israel. The studied material was divided into two groups, each corresponding to a period of 13 years. Group I included patients with mammary tumors under observation from 1978 to 1990, who rarely used EMF-generating appliances. Group II consisted of patients being under observation in the period between 1991 and 2003, characterized by much more extensive use of personal computers (more than 3 hours a day), mobile telephones, television sets, air conditioners and other household electrical appliances generating EMF. 200,527 biopsy and surgery samples were analyzed. Mammary tumors were found in 2824 women (1.4%), of which 1290 cases (45.6%) were observed in elderly women. Most of the observed tumors--1254 (97.2%)--were epithelial neoplasms. Mammary tumors were found in 585 elderly women in Group I and 705 women in Group II. The case records of these patients showed that 114 elderly women (19.5%) in Group I and 360 (51.1%) in Group II were regularly exposed to EMF (mostly from personal computers) for at least 3 hours a day (chi2=57.2, pEMF on the formation of all observed epithelial mammary tumors in Group II. This influence is most evident for invasive ductal carcinomas, which was the commonest form of cancer in elderly women.

  9. Induction of Cell Activation Processes by Low Frequency Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    Myrtill Simkó

    2004-01-01

    Full Text Available Electromagnetic fields (EMF such as those from electric power transmission and distribution lines (50/60 Hz have been associated with increased risk of childhood leukemia, cancer of the nervous system, and lymphomas. Several in vitro studies on EMF effects were performed to clarify the existing controversies, define the risks, and determine the possible mechanisms of adverse effects. In some of these reports, the effects were related to other mechanisms of carcinogenesis. Modification in cell proliferation was observed after EMF exposure and a few reports on cytotoxic effects have also been published. This limited review gives an overview of the current results of scientific research regarding in vitro studies on the effects of power line frequency EMF, but also cell biological mechanisms and their potential involvement in genotoxicity and cytotoxicity are discussed. Cell cycle control and signal transduction processes are included to elucidate the biochemical background of possible interactions. Exposure to EMF has been also linked to the incidence of leukemia and other tumors in some epidemiological studies and is considered as “possibly carcinogenic to humans”, but there is no well-established biological mechanism that explains such a relation. Furthermore, EMF is also shown as a stimulus for immune relevant cells (e.g., macrophages to release free radicals. It is known that chronic activation of macrophages is associated with the onset of phagocytosis and leads to increased formation of reactive oxygen species, which themselves may cause DNA damage and are suggested to lead to carcinogenesis. To demonstrate a possible interaction between EMF and cellular systems, we present a mechanistic model describing cell activation as a major importance for cellular response.

  10. Impact of high electromagnetic field levels on childhood leukemia incidence.

    Science.gov (United States)

    Teepen, Jop C; van Dijck, Jos A A M

    2012-08-15

    The increasing exposure to electromagnetic fields (EMFs) has raised concern, as increased exposure may result in an increased risk of childhood leukemia (CL). Besides a short introduction of CL and EMF, our article gives an evaluation of the evidence of a causal relation between EMF and CL by critically appraising the epidemiological and biological evidence. The potential impact is also estimated by the population attributable risk. The etiology of CL is largely unknown, but is probably multifactorial. EMF may be one of the environmental exposures involved. Three pooled analyses of case-control studies showed a 1.4- to 1.7-fold increased CL risk for extremely low-frequency EMF (ELF-EMF) exposure levels above 0.3 μT. Several biases may have played a role in these studies, but are unlikely to fully explain the increased risk. For effects of radiofrequency ELF evidence is lacking. None of the proposed biological mechanisms by which ELF-EMF might cause CL have been confirmed. The estimated overall population attributable risk was 1.9%, with the highest estimates in Northern America and Brazil (4.2% and 4.1%, respectively). The potential impact of EMF exposure on public health is probably limited, although in some countries exposure might be relatively high and thus might have a more substantial impact. We recommend nationwide surveys to gain more insight into the contemporary exposure levels among children. Reducing exposure from power lines near densely populated areas and schools is advised. Future epidemiological studies should focus on limiting bias. Copyright © 2012 UICC.

  11. Escape to infinity under the action of a potential and a constant electromagnetic field

    CERN Document Server

    Gascon, F G

    2003-01-01

    Escape to infinity is proved for a great variety of potentials, including the potential created by an infinite number of sources. Relativistic escape is studied. Escape in the presence of a constant electromagnetic field and a potential is also considered.

  12. Effect of radio frequency waves of electromagnetic field on the tubulin.

    Science.gov (United States)

    Taghi, Mousavi; Gholamhosein, Riazi; Saeed, Rezayi-Zarchi

    2013-09-01

    Microtubules (MTs) are macromolecular structures consisting of tubulin heterodimers and present in almost every eukaryotic cell. MTs fulfill all conditions for generation of electromagnetic field and are electrically polar due to the electrical polarity of a tubulin heterodimer. The calculated static electric dipole moment of about 1000 Debye makes them capable of being aligned parallel to the applied electromagnetic field direction. In the present study, the tubulin heterodimers were extracted and purified from the rat brains. MTs were obtained by polymerization in vitro. Samples of microtubules were adsorbed in the absence and in the presence of electromagnetic fields with radio frequency of 900 Hz. Our results demonstrate the effect of electromagnetic field with 900 Hz frequency to change the structure of MTs. In this paper, a related patent was used that will help to better understand the studied subject.

  13. MODEL FOR CALCULATING EFFECTIVE PARAMETERS OF MATRIX COMPOSITES FROM BI-ISOTROPIC PARTICLES WITH REGARD MULTIPLE REFLECTIONS OF ELECTROMAGNETIC FIELD

    National Research Council Canada - National Science Library

    V. T. Erofeenko

    2015-01-01

    .... Under the calculations of parameters, taking into account a multiple scattering of the field between particles, a new type of addition theorems, connecting basic spherical electromagnetic fields...

  14. The views of primary care physicians on health risks from electromagnetic fields

    DEFF Research Database (Denmark)

    Berg-Beckhoff, Gabi; Heyer, Kristina; Kowall, Bernd

    2010-01-01

    The aim of this study was to find out what primary care physicians in Germany think about the possible health risks of electromagnetic fields (EMF) and how they deal with this topic in discussions with patients.......The aim of this study was to find out what primary care physicians in Germany think about the possible health risks of electromagnetic fields (EMF) and how they deal with this topic in discussions with patients....

  15. Verification of Parallel C Code for Specific Absorption Rate (SAR) of Electromagnetic Fields (EMF)

    Science.gov (United States)

    2010-07-06

    for FDTD calculations of human exposure due to the electromagnetic fields ( EMF ) which was developed by Radio Frequency Radiation Branch, AFRL...SAR) of electromagnetic fields ( EMF ) 5a. CONTRACT NUMBER FA8655-09-1-3045 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...of non-ionizing radiation Pohorskega bataljona 215 Ljubljana 1000 Slovenia 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 9. SPONSORING

  16. Influence of thermal fluctuations on dynamics of charged particles in electromagnetic fields

    Science.gov (United States)

    Sametov, E. A.; Timirkhanov, R. A.; Vaulina, O. S.

    2017-12-01

    The numerical study of dynamics of the charged particles in the confined cloud located in a constant electromagnetic field is presented. Calculations are performed for ions with various masses in a wide range of system parameters. For the first time, an influence of thermal fluctuations of particles on their motion in an electromagnetic field is considered. Analytical estimations for the analysis of this effect are proposed.

  17. [Ecological significance of electromagnetic fields: the 20th century--century of electricity, the 21st--century of magnetism].

    Science.gov (United States)

    Lazetić, Bogosav

    2003-01-01

    The biosphere consists of all ecosystems of earth and is characterized by electromagnetic fields of different frequencies. Physics and natural sciences and disciplines are focused on their origin and characteristics. NATURAL ELECTROMAGNETIC FIELDS: There is a well defined idea that natural electromagnetic activity of the Earth's atmosphere throughout evolution led to appearance of electromagnetic homeostasis, i.e. maintenance of inner electromagnetic mileu. It can be supposed that during the evolution of living organisms natural electromagnetic fields were associated with biochemical processes and as a result of natural selection became an important information system and obligatory component of life. The results presented here show that there is no reason to doubt that natural electromagnetic fields are an important ecologic factor. On the contrary, we have to emphasize that natural electromagnetic environment is necessary for life on the Earth. Today intensity of artificial electromagnetic fields is ten to hundred times higher than of natural electromagnetic fields. Danger from electromagnetic fields is an acute and actual problem which increases knowing that there won't be a spot without artificial electromagnetic field on our planet.

  18. Risks perception of electromagnetic fields in Taiwan: the influence of psychopathology and the degree of sensitivity to electromagnetic fields.

    Science.gov (United States)

    Tseng, Mei-Chih Meg; Lin, Yi-Ping; Hu, Fu-Chang; Cheng, Tsun-Jen

    2013-11-01

    Little is known about the perceived health risks of electromagnetic fields (EMFs) and factors associated with risk perception in non-Western countries. Psychological conditions and risk perception have been postulated as factors that facilitate the attribution of health complaints to environmental factors. This study investigated people's perceived risks of EMFs and other environmental sources, as well as the relationships between risk perception, psychopathology, and the degree of self-reported sensitivity to EMFs. A total of 1,251 adults selected from a nationwide telephone interviewing system database responded to a telephone survey about the relationships between environmental sources and human health. The interview included questions assessing participants' psychiatric conditions and the presence and degree of sensitivity to EMFs. One hundred and seventy participants were self-identified as having sensitivity to EMFs, and 141 met the criteria for psychiatric conditions without EMF sensitivity. More than half of the survey respondents considered power lines and mobile phone base stations to affect people's health to a big extent. Higher sensitivity to EMFs, psychopathology, being female, being married, more years of education, and having a catastrophic illness had positive associations with perceived risks of EMF-related environmental sources as well as for all environmental sources combined. We observed no moderating effect of psychopathology on the association between degree of sensitivity to EMF and risk perception. Thus, psychopathology had influence on general people's risk perception without having influence on the relationship between people's degree of sensitivity to EMF and risk perception. The plausible explanations are discussed in the text. © 2013 Society for Risk Analysis.

  19. 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

  20. Impact of electromagnetic field on the pathogenicity of selected ...

    African Journals Online (AJOL)

    Kelly

    2013-07-17

    Jul 17, 2013 ... Accepted 14 June, 2013. The effect of exposing entomopathogenic bacteria isolated from tick (Rhipicephalus decoloratus) to ... harmful effects of ticks, it is essential to control their population. Present control .... dilution was exposed to electromagnetic radiation of 8 V input after which it was used to infect the ...

  1. A Note on Feynman Path Integral for Electromagnetic External Fields

    Science.gov (United States)

    Botelho, Luiz C. L.

    2017-08-01

    We propose a Fresnel stochastic white noise framework to analyze the nature of the Feynman paths entering on the Feynman Path Integral expression for the Feynman Propagator of a particle quantum mechanically moving under an external electromagnetic time-independent potential.

  2. Coupled dilaton and electromagnetic field in cylindrically symmetric ...

    Indian Academy of Sciences (India)

    An exact solution is obtained for coupled dilaton and electromagnetic field in a cylindrically symmetric spacetime where an axial magnetic field as well as a radial electric field both are present. Depending on the choice of the arbitrary constants our solution reduces either to dilatonic gravity with pure electric field or to that ...

  3. Influence of Electric, Magnetic, and Electromagnetic Fields on the Circadian System: Current Stage of Knowledge

    Directory of Open Access Journals (Sweden)

    Bogdan Lewczuk

    2014-01-01

    Full Text Available One of the side effects of each electrical device work is the electromagnetic field generated near its workplace. All organisms, including humans, are exposed daily to the influence of different types of this field, characterized by various physical parameters. Therefore, it is important to accurately determine the effects of an electromagnetic field on the physiological and pathological processes occurring in cells, tissues, and organs. Numerous epidemiological and experimental data suggest that the extremely low frequency magnetic field generated by electrical transmission lines and electrically powered devices and the high frequencies electromagnetic radiation emitted by electronic devices have a potentially negative impact on the circadian system. On the other hand, several studies have found no influence of these fields on chronobiological parameters. According to the current state of knowledge, some previously proposed hypotheses, including one concerning the key role of melatonin secretion disruption in pathogenesis of electromagnetic field induced diseases, need to be revised. This paper reviews the data on the effect of electric, magnetic, and electromagnetic fields on melatonin and cortisol rhythms—two major markers of the circadian system as well as on sleep. It also provides the basic information about the nature, classification, parameters, and sources of these fields.

  4. Influence of electric, magnetic, and electromagnetic fields on the circadian system: current stage of knowledge.

    Science.gov (United States)

    Lewczuk, Bogdan; Redlarski, Grzegorz; Zak, Arkadiusz; Ziółkowska, Natalia; Przybylska-Gornowicz, Barbara; Krawczuk, Marek

    2014-01-01

    One of the side effects of each electrical device work is the electromagnetic field generated near its workplace. All organisms, including humans, are exposed daily to the influence of different types of this field, characterized by various physical parameters. Therefore, it is important to accurately determine the effects of an electromagnetic field on the physiological and pathological processes occurring in cells, tissues, and organs. Numerous epidemiological and experimental data suggest that the extremely low frequency magnetic field generated by electrical transmission lines and electrically powered devices and the high frequencies electromagnetic radiation emitted by electronic devices have a potentially negative impact on the circadian system. On the other hand, several studies have found no influence of these fields on chronobiological parameters. According to the current state of knowledge, some previously proposed hypotheses, including one concerning the key role of melatonin secretion disruption in pathogenesis of electromagnetic field induced diseases, need to be revised. This paper reviews the data on the effect of electric, magnetic, and electromagnetic fields on melatonin and cortisol rhythms-two major markers of the circadian system as well as on sleep. It also provides the basic information about the nature, classification, parameters, and sources of these fields.

  5. The superluminal velocities as the consequence of non-classical states of electromagnetic field

    Science.gov (United States)

    Veklenko, B. A.

    2017-06-01

    It was shown within the framework of conventional quantum electrodynamics, and without using perturbation theory, the presence of superluminal signals, transferring the information, while investigating the scattering of quantum electromagnetic field by excited atom. The superluminal signals are impossible in the theory of free fields, but their existence is predicted by the theory of interacting fields.

  6. Simple and effective monitoring of the electromagnetic field in the smart cities arena

    Science.gov (United States)

    Ares-Pena, Francisco J.; Franceschetti, Giorgio; Iodice, Antonio; Salas-Sánchez, Aarón A.

    2016-08-01

    A simple and economical method for monitoring the electromagnetic field intensity in built-up areas is presented. The method is based on the measurement of the field level over a limited number of points at street level in the city and their transmission to an operative control center, where the field values all over the city are correctly interpolated in real time. Citizens might obtain these values at their sites, via Internet, or by connecting with a dedicated call center. Numerical evaluations of the electromagnetic field intensity via the new developed model and confirming experimental results are finally presented.

  7. Foldy–Wouthuysen transformation applied to the interaction of an electron with ultrafast electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Hinschberger, Y. [Institut de Physique et Chimie des Matériaux de Strasbourg, 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2 (France); Hervieux, P.-A., E-mail: hervieux@ipcms.u-strasbg.fr [Institut de Physique et Chimie des Matériaux de Strasbourg, 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2 (France)

    2012-01-30

    By means of the Foldy–Wouthuysen transformation the nonrelativistic approximation of the external-electromagnetic-field Dirac equation to fifth order in powers of 1/m is obtained. Generalizing this result we postulate a general expression of the direct spin–field electronic Hamiltonian valid at any order in 1/m. -- Highlights: ► Coupling of an ultrafast electromagnetic field with the electron spin is investigated using a first-principles approach. ► May be involved in the coherent laser-induced demagnetization of ferromagnetic materials. ► A general expression of the direct spin–field electronic Hamiltonian is postulated.

  8. Inhomogeneous Bulk Viscous Fluid Universe with Electromagnetic Field and Variable Λ-Term

    Science.gov (United States)

    Pradhan, Anirudh; Rai, Vandana; Jotania, Kanti

    2008-07-01

    Cylindrically symmetric inhomogeneous cosmological model for bulk viscous fluid distribution with electromagnetic field is obtained. The source of the magnetic field is due to an electric current produced along the z-axis. F12 is the non-vanishing component of electromagnetic field tensor. To get the deterministic solution, it has been assumed that the expansion θ in the model is proportional to the shear σ. The values of cosmological constant for these models are found to be small and positive at late time, which are consistent with the results from recent supernovae Ia observations. Physical and geometric aspects of the models are also discussed in presence and absence of magnetic field.

  9. Occupational medicine and electromagnetic fields; Medecine du travail et champs electromagnetiques

    Energy Technology Data Exchange (ETDEWEB)

    Seze, R. de [Institut National de l' Environnement Industriel et des Risques, 60 - Verneuil en Halatte (INERIS) (France)

    2001-07-01

    Numerous industrial areas are concerned by electromagnetic fields exposures. The most intense sources are constituted by high frequencies. The most known are the relay antenna for cellular radio communications (type GSM). The principal sources of electromagnetic fields are given and the levels fields susceptible to be encountered at working posts. The interaction mechanisms of fields are given in function of frequencies, then the biological effects are studied. The results of epidemiological studies are synthesised. The recommendations in France and in Europe are presented as well the standardisation organisms. (N.C.)

  10. Composing constraint solvers

    NARCIS (Netherlands)

    P. Zoeteweij (Peter)

    2005-01-01

    htmlabstractComposing constraint solvers based on tree search and constraint propagation through generic iteration leads to efficient and flexible constraint solvers. This was demonstrated using OpenSolver, an abstract branch-and-propagate tree search engine that supports a wide range of relevant

  11. A few categories of electromagnetic field problems treated through Fuzzy Logic

    Science.gov (United States)

    Lolea, M. S.; Dzitac, S.

    2018-01-01

    The paper deals with the problems of fuzzy logic applied in the field of electromagnetism. In the first part, there are presented some theoretical aspects regarding the characteristics and the application of the fuzzy logic in the general case. Are presented then, some categories of electromagnetic field problems treated by fuzzy logic. The accent is on the effects of exposure to the electromagnetic field on the human body. For this approach is dedicated a paragraph at the end of the paper. There is an application on how to treat by fuzzy logic the effects of electric field exposure. For this purpose, the fuzzy toolbox existing in the Matlab software and the results of some electric field strength measurements into a power substation are used. The results of the study and its conclusions are analyzed and exposed at the end of the paper.

  12. Simulation of Heat Transfer and Electromagnetic Fields of Protected Microcomputers

    Directory of Open Access Journals (Sweden)

    Josef Lakatos

    2006-01-01

    Full Text Available The paper presents results of collaboration between Department of mechatronics and electronics at University of Žilina and VÚVT Engineering a.s. Žilina in area of heat transfer simulations and disturbing electromagnetic radiation simulations in computer construction. The simulations results were used in development of protected microcomputer prototypes in frame of applied research at both of workplaces.

  13. Design, Modeling, and Measurement of a Metamaterial Electromagnetic Field Concentrator

    Science.gov (United States)

    2012-03-22

    Index of Refraction. In his treatise, “The First Book Opticks,” Sir Isaac Newton described a property of light rays called refrangibility to...Independence in Antennae,” Fractals, 7(1):79–84, 1999. [18] Humphries , S., Jr. “Finite-element Methods for Electromagnetics,” 2010. [19] Inglesfield, J...Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway

  14. Radiation pressure and the linear momentum of the electromagnetic field

    OpenAIRE

    Mansuripur, Masud

    2013-01-01

    We derive the force of the electromagnetic radiation on material objects by a direct application of the Lorentz law of classical electro-dynamics. The derivation is straightforward in the case of solid metals and solid dielectrics, where the mass density and the optical constants of the media are assumed to remain unchanged under internal and external pressures, and where material flow and deformation can be ignored. For metallic mirrors, we separate the contribution to the radiation pressure...

  15. Environmental impact of the use of radiofrequency electromagnetic fields in physiotherapeutic treatment.

    Science.gov (United States)

    Gryz, Krzysztof; Karpowicz, Jolanta

    2014-01-01

    Electromagnetic fields used in physiotherapeutic treatment affect not only patients, but also physiotherapists, patients not undergoing treatment and electronic medical equipment. The aim of the work was to study the parameters of the electromagnetic fields of physiotherapeutic devices with respect to requirements regarding the protection of electronic devices, including medical implants, against electromagnetic intererence, and the protection of the general public (patients not undergoing treatment and bystanders), as well as medical personnel, against the health hazards caused by electromagnetic exposure. The spatial distribution of electric and magnetic field strength was investigated near 3 capacitive short-wave and 3 long-wave diathermies and 3 ultrasound therapy units, as along with the capacitive electric currents caused by electromagnetic field interaction in the upper limbs of the physiotherapists operating these devices. The physiotherapists' exposure to electromagnetic fields depends on the spatial organisation of the workspace and their location during treatment. Electric fields able to interfere with the function of electronic medical implants and in whic anyone not undergoing treatment should not be present were measured up to 150-200 cm away from active applicators of short-wave diathermy, and up to 40-45 cm away from long-wave diathermy ones. Electric fields in which workers should not be present were measured up to 30-40 cm away from the applicators and cables of active short-wave diathermy devices. A capacitive electric current with a strength exceeding many times the international recommendations regarding workers protection was measured in the wrist while touching applicators and cables of active short-wave diathermy devices. The strongest environmental electromagnetic hazards occur near short-wave diathermy devices, and to a lesser degree near long-wave diathermy devices, but were not found near ultrasound therapy units.

  16. Coherent microwave electromagnetic field as a physical model of multicellular organism macroscopic quantum states

    Science.gov (United States)

    Gizhko, Vasiliy V.; Sit'ko, S. P.

    1994-08-01

    Analysis of semiclassic theory of radiation interaction is done in respect to the millimeter range wave lengths and water milien of biological objects. General characteristics of electromagnetic limit cicles are analyzed with respect to the peculiarity of human anatomy, the correspondence between these characteristics and laws of classical acupuncture system topography is determined. General condition of multicellular organism's stability on all of development stages are formulated as a space quantum conditions for eigen electromagnetic field's states.

  17. Effect of three common sources of electromagnetic fields on health

    Energy Technology Data Exchange (ETDEWEB)

    Mortazavi, S.M.J.; Ahmadi, J.; Behnejad, B. [Rafsanjan Univ. of Medical Sciences, Rafsanjan (Iran, Islamic Republic of)

    2006-07-01

    Background And Aims: The number of people complaining about different symptoms that may be associated with exposure to electromagnetic fields (E.M.F.) has increased rapidly during the past years. Students use both mobile phones and video display terminals frequently. The purpose of this study was to investigate the association of mobile phone use and E.M.F. health hazards. Methods: Basic demographic data and self-reported symptoms were sought using a questionnaire administered to all apparently healthy students at Rafsanjan University of Medical Sciences (R.U.M.S.) and Vali-e-Asr University (V.A.U.). Questions ab out some major confounding factors such as age, gender, amount of video display terminal work were also included. All symptoms were self reported and there was no medical examination. Exact Fisher Test was used for data analysis. Results: 518 complete responses were collected. The responders comprised 317 Vali-e-Asr students (61.2%) and 201 R.U.M.S. students (38.8%). The gender distribution was male 175 33.8%), and female 343 (66.2 %). Thirty percent of the students had been using mobile phones (26% in female students and 38.2% in males, P<0.01). There was a significant difference between the frequency of mobile phone users in medical/par a medical (41.3%) and non-medical (23%) students (P<0. 001). Thirty six percent of the students had been using cord-less phones (no statistically significant gender difference). 56.3% used cathode ray tubes (C.R.T.) as computer monitors (47.1% in female students and 74.3% in males, P<0.001). Regarding self-reported symptoms, headache (52%), fatigue (35%), difficulties in concentration (31.7%), vertigo/dizziness (30%), attention disorders (28.8%), nervousness (28.1%), palpitation (14.7%), low back pain (14.3%), myalgia (12.3%), and tinnitus (10%) were the main self-reported symptoms. There were significantly more women with headache, dizziness, myalgia, and nervousness than men (in each case P<0.001). No significant

  18. [Effect of exposure to extremely low-frequency electromagnetic fields on liver function of workers].

    Science.gov (United States)

    Liu, Xin; Zhao, Long-yu; Chen, Hui-ling; Liu, Cong; Liu, Xiao-dong; Ma, Shu-mei

    2013-08-01

    To examine the effect of exposure to extremely low-frequency electromagnetic fields (ELF EMFs) on the liver function of workers. The workers in a factory were selected as subjects, and the recent physical examination data of these workers were collected. The workers aged 20∼40 years and with more than 2 years' working experience were included for analysis; considering the intensity of electromagnetic field, the workers exposed to less electromagnetic radiation were assigned to exposure I group (n = 123), those exposed to more electromagnetic radiation to exposure II group (n = 229), and those not exposed to electromagnetic radiation to control group (n = 212). There were no significant differences in sex, age, height, and body weight between the three groups (P > 0.05). Physical examination, including measurements of direct bilirubin (DBil), alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT), and albumin, was performed in a health examination center. The intensity of electromagnetic field was measured by EFA-300 power frequency electromagnetic field analyzer, and the intensity of noise by AWA5610D integrating sound level meter. The intensities of electric field and the magnetic field in exposure II group were significantly higher than those in the exposure I group. The levels of ALT, ALP, AST, GGT and albumin in exposure II group were significantly higher than those in exposure I group and control group. However, the level of direct bilirubin in exposure II group was significantly lower than that in exposure I group and control group. Occupational exposure to ELF EMFs may affect human liver function.

  19. Development of a numerical modelling tool for combined near field and far field wave transformations using a coupling of potential flow solvers

    DEFF Research Database (Denmark)

    Verbrugghe, Tim; Troch, Peter; Kortenhaus, Andreas

    2016-01-01

    of a wave-structure interaction solver and a wave propagation model, both based on the potential flow theory. This paper discusses the coupling method and illustrates the functionality with a proof-of-concept. Additionally, a projection of the evolution of the numerical tool is given. It can be concluded...

  20. The directive on electromagnetic fields and its application; Die Verordnung ueber elektromagnetische Felder in der Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Brueggemeyer, H. [Niedersaechsisches Landesamt fuer Oekologie, Hannover (Germany); Dib, R. [Fachhochschule Giessen-Friedberg, Friedberg (Germany); Eberle, W. [Hessisches Ministerium fuer Umwelt, Energie, Jugend, Familie und Gesundheit, Wiesbaden (Germany); Freund, H. [Teweratio Unternehmensberatung GmbH, Stuttgart (Germany); Hirsch, F. [FGH, Mannheim (Germany); Stamm, A. [PreussenElektra AG, Hannover (Germany); Wiedemann, P. [Forschungszentrum Juelich GmbH (Germany)

    1997-11-03

    On January 1, 1997 the directive concerning the implementation of the German Federal Emission Control Act (directive on electromagnetic fields) took effect. The article contains: Explanation of the directive, calculation and measurement of low frequency electric and magnetic fields, electromagnetic fields of high and medium voltage powerlines as well as medium voltage switching stations. Another aspect discussed is the risk perception of powerline frequency electromagnetic fields by laymen and information management in power utilities. (orig./RHM) [Deutsch] Am 1. Januar 1997 trat die Verordnung zur Durchfuehrung des Bundes-Immissionsschutzgesetzes (Verordnung ueber elektromagnetischer Felder) in Kraft. Im folgenden Beitrag wird nach der Erlaeuterung der 26. BImSchV auf die Berechnung und Messung elektromagnetischer Felder (EMF) sowie auf die Felder von Hoch- und Mittelspannungsleitungen, Schaltanlagen und Stationen eingegangen. Abschliessend werden die Themen Risikowahrnehmung in der Bevoelkerung und EMF-Informationsmanagement behandelt. (orig./RHM)

  1. EFFECT OF ELECTROMAGNETIC FIELD ON THE SPOILAGE FUNGI OF SOME SELECTED EDIBLE FRUITS IN SOUTHWESTERN, NIGERIA

    Directory of Open Access Journals (Sweden)

    Bamidele J. Akinyele

    2012-10-01

    Full Text Available The influence of electromagnetic field wave on the survival of spoilage fungi associated with some edible fruits consumed in southwestern, Nigeria was studied using cashew (Anacardium occidentale L., pineapple (Ananas comosus, carrot (Daucus carota, cucumber (Cucumis sativus, apple (Malus domestica and African star apple (Chrysophyllum africanum. The spoilage fungi used include the genera of Aspergillus, Penicillium, Articulospora, Mucor, Staphylotrichum, Bisbyopeltis, Fusarium, Rhizopus and a yeast, Saccharomyces cerevisiae. There was a general decrease in fungal growth as shown in the number of spores produced with increase in exposure time of isolates to electromagnetic field except in Articulospora inflata, Penicillium italicum and Mucor mucedo where there was stimulatory effect as there was increase in the fungal spores compared to the control. A decrease was also observed in growth of the fungal isolates with increase in the intensity of the electromagnetic field at voltage of 7 V to 10 V and from 10 V to 13 V. The highest percentage reduction was recorded by Bisbyopeltis phoebesii at intensity of voltage 13V after 60 minutes of exposure. Exposure of the fruits to electromagnetic field wave did not alter the nutrient components of the fruits as observed in the proximate and mineral contents of the treated and untreated fruits. The result of the study revealed that electromagnetic field wave has great potential for use in the control of fruits spoilage and food preservation.

  2. [Influence of electromagnetic fields on the emotional behaviour of rats].

    Science.gov (United States)

    Semenova, T P; Medvinskaia, N I; Bliskovka, G I; Akoev, I G

    2000-01-01

    The effects of ultra low power pulse-width + modulation electromagnetic radiation (EMR, power density 10 mc/Wt/cm2, carrying frequency 915 MHz, modulating pulses with frequency 4, 6, 16 and 20 Hz, duration 10 min) on the rat emotional behavior and motor activity in the elevated plus-maze were studied. It was established that EMR (frequency of modulation 4 and 6 Hz) significantly decreased the emotionally negative reactions of anxiety and fear by a factor of 3.7 (p negative reactions of anxiety and fear and decreased by a factor of 1.8 (p < 0.05) the exploratory activity in rats.

  3. Cometary dust dynamics and polarization in electromagnetic radiation fields

    Science.gov (United States)

    Herranen, J.; Markkanen, J.; Muinonen, K.

    2017-09-01

    In our work, we apply a fast solution of electromagnetic scattering to determine the induced spin and movement of a dust particle in a cometary coma. The resulted aligned spinning state is then used to determine the observable polarization of the dust, and compared against the randomly averaged polarization of the same particle. We find that measurable effects arise due to the alignment. In the future, similar methods can be used to model the dynamics and in turn the polarization of the whole coma.

  4. Dosimetry of Exposure to Electromagnetic Fields in Daily Life and Medical Applications

    NARCIS (Netherlands)

    J.F. Bakker (Jurriaan)

    2012-01-01

    textabstractElectromagnetic fields (EMF) are present everywhere in our environment but are usually invisible to the human eye. EMF for example generated by mobile phones and 50Hz power lines, can cause electric fields, currents and tissue heating in the human body. In the past, exposure limits were

  5. Conditions to preserve quantum entanglement of quadrature fluctuation fields in electromagnetically induced transparency media.

    Science.gov (United States)

    Chuang, You-Lin; Lee, Ray-Kuang

    2009-05-15

    We study the propagation of quantum fields through an electromagnetically induced transparency (EIT) medium with initially two squeezed and one coherent states. Conditions to preserve and to establish nonseparation criteria for perturbed quantized fluctuation fields are demonstrated. The results in this work provide a guideline for using EIT media as quantum light devices.

  6. Effects of electromagnetic field of 33 and 275 kV influences on ...

    African Journals Online (AJOL)

    The effects of electromagnetic fields (EMF) from 33 and 275 kV high voltage transmission line on biochemical and antioxidant system changes in mustard leaf (Brassica chinensis) were investigated under field condition. Mustard leaves were exposed to EMF from power lines at distances of 0, 3, 6, 9, 10, 12, 15, 18, 20, 21, ...

  7. Exact Electromagnetic Fields Produced by a Finite Wire with Constant Current

    Science.gov (United States)

    Jimenez, J. L.; Campos, I.; Aquino, N.

    2008-01-01

    We solve exactly the problem of calculating the electromagnetic fields produced by a finite wire with a constant current, by using two methods: retarded potentials and Jefimenko's formalism. One result in this particular case is that the usual Biot-Savart law of magnetostatics gives the correct magnetic field of the problem. We also show…

  8. Higgs boson decay into two photons in an electromagnetic background field

    DEFF Research Database (Denmark)

    Nielsen, N. K.

    2014-01-01

    The amplitude for Higgs boson decay into two photons in a homogeneous and time-independent magnetic field is investigated by proper-time regularization in a gauge-invariant manner and is found to be singular at large field values. The singularity is caused by the component of the charged vector...... boson field that is tachyonic in a strong magnetic field. Also, tools for the computation of the amplitude in a more general electromagnetic background are developed....

  9. Numerical simulation of electro-magnetic and flow fields of TiAl melt under electric field

    Directory of Open Access Journals (Sweden)

    Zhang Yong

    2010-08-01

    Full Text Available This article aims at building an electromagnetic and fluid model, based on the Maxwell equations and Navier-Stokes equations, in TiAl melt under two electric fields. FEM (Finite Element Method and APDL (ANSYS Parametric Design Language were employed to perform the simulation, model setup, loading and problem solving. The melt in molds of same cross section area with different flakiness ratio (i.e. width/depth under the load of sinusoidal current or pulse current was analyzed to obtain the distribution of electromagnetic field and flow field. The results show that the induced magnetic field occupies sufficiently the domain of the melt in the mold with a flakiness ratio of 5:1. The melt is driven bipolarly from the center in each electric field. It is also found that the pulse electric field actuates the TiAl melt to flow stronger than what the sinusoidal electric field does.

  10. Electromagnetic Heating of Heavy Oil and Bitumen: A Review of Experimental Studies and Field Applications

    Directory of Open Access Journals (Sweden)

    Albina Mukhametshina

    2013-01-01

    Full Text Available Viscosity is a major obstacle in the recovery of low API gravity oil resources from heavy oil and bitumen reservoirs. While thermal recovery is usually considered the most effective method for lowering viscosity, for some reservoirs introducing heat with commonly implemented thermal methods is not recommended. For these types of reservoirs, electromagnetic heating is the recommended solution. Electromagnetic heating targets part of the reservoir instead of heating the bulk of the reservoir, which means that the targeted area can be heated up more effectively and with lower heat losses than with other thermal methods. Electromagnetic heating is still relatively new and is not widely used as an alternate or addition to traditional thermal recovery methods. However, studies are being conducted and new technologies proposed that could help increase its use. Therefore, the objective of this study is to investigate the recovery of heavy oil and bitumen reservoirs by electromagnetic heating through the review of existing laboratory studies and field trials.

  11. Evaluation Of Electromagnetic Fields For Frequencies 900 MHz-1 800 MHz In Tirana

    Directory of Open Access Journals (Sweden)

    Kuqi Dhurata

    2015-07-01

    Full Text Available Abstract The massive use of mobile phone as a communication tool nowadays is accompanied the ever increasing interest of the public and researchers for the possibly impact on human health as a result of exposure to the electromagnetic fields that accompany these devices. Therefore knowing the level of exposure electromagnetic fields of this electronic equipment has been and will be in the future interest object to the public and the subject of study for the researchers. In this paper are presents the results of measurements of electromagnetic fields for the frequencies 900 MHz - 1800 MHz used in mobile telephone in Tirana. These frequencies are included in the area radio frequency RF and Microwave MW 300 Hz - 300 GHz in the spectrum of electromagnetic waves and belong to non-ionizing radiation. The measurements were performed in different areas of Tirana. The purpose is to assess the level of exposure electromagnetic fields especially near areas where mobile antennas are mounted construction of dynamic digital mapping and comparison with the permitted levels of the exposure defined by the International Commission of Non Ionizing Radiation Protection ICNIRP. Through this publication the aim of the authors is to provide real information and reliable for the population.

  12. Research and Evaluation of the Energy Flux Density of the Mobile Phone Electromagnetic Field

    Directory of Open Access Journals (Sweden)

    Pranas Baltrėnas

    2012-12-01

    Full Text Available The article analyses variations in the energy flux density of the electromagnetic field of 10 mobile phones depending on distance. The studies have been conducted using three modes: sending a text message, receiving a text message and connecting a mobile phone to the Internet. When text messages are received or sent from a mobile phone, the values of the energy flux density of the mobile phone electromagnetic field exceed the safe allowable limit and make 10 μW / cm². A distance of 10, 20 and 30 cm from a mobile phone is effective protection against the energy flux density of the electromagnetic field when writing texts, receiving messages or connecting to the mobile Internet.Article in Lithuanian

  13. The effect of electromagnetic fields emitted by mobile phones on human sleep.

    Science.gov (United States)

    Loughran, Sarah P; Wood, Andrew W; Barton, Julie M; Croft, Rodney J; Thompson, Bruce; Stough, Con

    2005-11-28

    Previous research has suggested that exposure to radiofrequency electromagnetic fields increases electroencephalogram spectral power in non-rapid eye movement sleep. Other sleep parameters have also been affected following exposure. We examined whether aspects of sleep architecture show sensitivity to electromagnetic fields emitted by digital mobile phone handsets. Fifty participants were exposed to electromagnetic fields for 30 min prior to sleep. Results showed a decrease in rapid eye movement sleep latency and increased electroencephalogram spectral power in the 11.5-12.25 Hz frequency range during the initial part of sleep following exposure. These results are evidence that mobile phone exposure prior to sleep may promote rapid eye movement sleep and modify the sleep electroencephalogram in the first non-rapid eye movement sleep period.

  14. Electric conductivity in electrolyte solution under external electromagnetic field by nonequilibrium molecular dynamics simulation.

    Science.gov (United States)

    Yang, LiJun; Huang, KaMa

    2010-07-01

    Nonequilibrium molecular dynamics (NMD) simulations are performed to investigate the effects of an external electromagnetic (E/M) field on NaCl electrolyte solutions at different temperatures using the SPC/E model. The electromagnetic wave propagates in the z-axis direction with a frequency of 2.45 GHz, and the intensity of the E/M field is 3 x 10(4) V/m. The results indicate that as the concentration of the electrolyte solution increased, the diffusion coefficient and the ionic mobility gradually decreased, but the electric conductivity gradually increased. In addition, all three of them will be increased when the temperature is increased. But their value will be reduced when the electromagnetic field is applied.

  15. A Method for Solving the Time-Periodic Electromagnetic Field Problem in Ferromagnetic Shielding

    Directory of Open Access Journals (Sweden)

    Iosif Nemoianu

    2009-05-01

    Full Text Available Ferromagnetic shield is an efficient solution for shielding the static and periodic electromagnetic field. Therefore, it is also a shilding solution for an electromagnetic field having a rich contain of harmonics. Using the polarization fixed point method, the nonlinear media is replaced by a linear one having the vacuum permeability and a magnetization that is iteratively corrected by the flux density. For each harmonic of the magnetization, the electromagnetic field may be obtained by solving the sinusoidal steady-state eddy-current equation in the shield. The solution process can be started by retaining a small number of harmonics and, finaly, the acuracy of the solution may be improved with adding some more. The proposed method always yields to stable results, even when the characteristic B-H is strongly nonlinear, and has a superior computational efficiency with respect to various time-stepping techniques and to the “harmonic balance method”.

  16. Growth stimulation of biological cells and tissue by electromagnetic fields and uses thereof

    Science.gov (United States)

    Wolf, David A. (Inventor); Goodwin, Thomas J. (Inventor)

    2004-01-01

    The present invention provides systems for growing two or three dimensional mammalian cells within a culture medium facilitated by an electromagnetic field, and preferably, a time varying electromagnetic field. The cells and culture medium are contained within a fixed or rotating culture vessel, and the electromagnetic field is emitted from at least one electrode. In one embodiment, the electrode is spaced from the vessel. The invention further provides methods to promote neural tissue regeneration by means of culturing the neural cells in the claimed system. In one embodiment, neuronal cells are grown within longitudinally extending tissue strands extending axially along and within electrodes comprising electrically conductive channels or guides through which a time varying electrical current is conducted, the conductive channels being positioned within a culture medium.

  17. Oxidative and genotoxic effects of 900 MHz electromagnetic fields in the earthworm Eisenia fetida.

    Science.gov (United States)

    Tkalec, Mirta; Stambuk, Anamaria; Srut, Maja; Malarić, Krešimir; Klobučar, Göran I V

    2013-04-01

    Accumulating evidence suggests that exposure to radiofrequency electromagnetic field (RF-EMF) can have various biological effects. In this study the oxidative and genotoxic effects were investigated in earthworms Eisenia fetida exposed in vivo to RF-EMF at the mobile phone frequency (900 MHz). Earthworms were exposed to the homogeneous RF-EMF at field levels of 10, 23, 41 and 120 V m(-1) for a period of 2h using a Gigahertz Transversal Electromagnetic (GTEM) cell. At the field level of 23 V m(-1) the effect of longer exposure (4h) and field modulation (80% AM 1 kHz sinusoidal) was investigated as well. All exposure treatments induced significant genotoxic effect in earthworms coelomocytes detected by the Comet assay, demonstrating DNA damaging capacity of 900 MHz electromagnetic radiation. Field modulation additionally increased the genotoxic effect. Moreover, our results indicated the induction of antioxidant stress response in terms of enhanced catalase and glutathione reductase activity as a result of the RF-EMF exposure, and demonstrated the generation of lipid and protein oxidative damage. Antioxidant responses and the potential of RF-EMF to induce damage to lipids, proteins and DNA differed depending on the field level applied, modulation of the field and duration of E. fetida exposure to 900 MHz electromagnetic radiation. Nature of detected DNA lesions and oxidative stress as the mechanism of action for the induction of DNA damage are discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Particle Production in Strong Electromagnetic Fields in Relativistic Heavy-Ion Collisions

    Directory of Open Access Journals (Sweden)

    Kirill Tuchin

    2013-01-01

    Full Text Available I review the origin and properties of electromagnetic fields produced in heavy-ion collisions. The field strength immediately after a collision is proportional to the collision energy and reaches ~mπ2 at RHIC and ~10mπ2 at LHC. I demonstrate by explicit analytical calculation that after dropping by about one-two orders of magnitude during the first fm/c of plasma expansion, it freezes out and lasts for as long as quark-gluon plasma lives as a consequence of finite electrical conductivity of the plasma. Magnetic field breaks spherical symmetry in the direction perpendicular to the reaction plane, and therefore all kinetic coefficients are anisotropic. I examine viscosity of QGP and show that magnetic field induces azimuthal anisotropy on plasma flow even in spherically symmetric geometry. Very strong electromagnetic field has an important impact on particle production. I discuss the problem of energy loss and polarization of fast fermions due to synchrotron radiation, consider photon decay induced by magnetic field, elucidate J/ψ dissociation via Lorentz ionization mechanism, and examine electromagnetic radiation by plasma. I conclude that all processes in QGP are affected by strong electromagnetic field and call for experimental investigation.

  19. [Patient exposure to electromagnetic fields in magnetic resonance scanners: a review].

    Science.gov (United States)

    Guibelalde del Castillo, E

    2013-12-01

    The use of non-ionizing electromagnetic fields in the low frequency end of the electromagnetic spectrum and static fields, radiofrequencies (RF), and microwaves is fundamental both in modern communication systems and in diagnostic medical imaging techniques like magnetic resonance imaging (MRI). The proliferation of these applications in recent decades has led to intense activity in developing regulations to guarantee their safety and to the establishment of guidelines and legal recommendations for the public, workers, and patients. In April 2012 it was foreseen that the European Parliament and Council would approve and publish a directive on the minimum health and safety requirements regarding the exposure of workers to the risks arising from electromagnetic fields, which would modify Directive 2004/40/EC. New studies related to the exposure to electromagnetic radiation and its impact on health published in recent years have led to a new postponement, and it is now foreseen that the directive will come into effect in October 2013. One of the most noteworthy aspects of the new version of the directive is the exclusion of the limits of occupational exposure to electromagnetic fields in the clinical use of MRI. In exchange for this exception, physicians and experts in protection against non-ionizing radiation are asked to make additional efforts to train workers exposed to non-ionizing radiation and to establish mechanisms to guarantee the correct application of non-ionizing electromagnetic fields in patients, along similar lines to the principles of justification and optimization established for ionizing radiation. On the basis of the most recently published studies, this article reviews some safety-related aspects to take into account when examining patients with MRI with high magnetic fields. Copyright © 2013 SERAM. Published by Elsevier Espana. All rights reserved.

  20. Localization from near-source quasi-static electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Mosher, John Compton [Univ. of Southern California, Los Angeles, CA (United States)

    1993-09-01

    A wide range of research has been published on the problem of estimating the parameters of electromagnetic and acoustical sources from measurements of signals measured at an array of sensors. In the quasi-static electromagnetic cases examined here, the signal variation from a point source is relatively slow with respect to the signal propagation and the spacing of the array of sensors. As such, the location of the point sources can only be determined from the spatial diversity of the received signal across the array. The inverse source localization problem is complicated by unknown model order and strong local minima. The nonlinear optimization problem is posed for solving for the parameters of the quasi-static source model. The transient nature of the sources can be exploited to allow subspace approaches to separate out the signal portion of the spatial correlation matrix. Decomposition techniques are examined for improved processing, and an adaptation of MUtiple SIgnal Characterization (MUSIC) is presented for solving the source localization problem. Recent results on calculating the Cramer-Rao error lower bounds are extended to the multidimensional problem here. This thesis focuses on the problem of source localization in magnetoencephalography (MEG), with a secondary application to thunderstorm source localization. Comparisons are also made between MEG and its electrical equivalent, electroencephalography (EEG). The error lower bounds are examined in detail for several MEG and EEG configurations, as well as localizing thunderstorm cells over Cape Canaveral and Kennedy Space Center. Time-eigenspectrum is introduced as a parsing technique for improving the performance of the optimization problem.

  1. Resonances and circuit theory for the interaction of metallic disks and annuli with an electromagnetic field.

    Science.gov (United States)

    Chui, S T; Du, J J; Yau, S T

    2014-11-01

    To understand the nature of the electromagnetic resonances of finite metallic surfaces, we formulate a rigorous and rapidly convergent circuit theory for the interaction of a metallic disk and a metallic annulus with an electromagnetic field. Expressions for the current induced and the resonance condition are derived. A new understanding of the nature of the resonances is obtained. For half of the resonances we find a divergent electric field at the edge of the disk, even though it is smooth in shape. For the disk, we compare with previous results using vector spheroidal wave functions and found good agreement for the resonance condition. Our approach can be generalized to other finite surfaces.

  2. Deuteron electromagnetic form factors in a renormalizable formulation of chiral effective field theory

    Energy Technology Data Exchange (ETDEWEB)

    Epelbaum, E. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Fakultaet fuer Physik und Astronomie, Bochum (Germany); Gasparyan, A.M. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Fakultaet fuer Physik und Astronomie, Bochum (Germany); SSC RF ITEP, Moscow (Russian Federation); Gegelia, J. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Fakultaet fuer Physik und Astronomie, Bochum (Germany); Tbilisi State University, Tbilisi (Georgia); Schindler, M.R. [University of South Carolina, Department of Physics and Astronomy, Columbia (United States)

    2014-03-15

    We calculate the deuteron electromagnetic form factors in a modified version of Weinberg's chiral effective field theory approach to the two-nucleon system. We derive renormalizable integral equations for the deuteron without partial wave decomposition. Deuteron form factors are extracted by applying the Lehmann-Symanzik-Zimmermann reduction formalism to the three-point correlation function of deuteron interpolating fields and the electromagnetic current operator. Numerical results of a leading-order calculation with removed cutoff regularization agree well with experimental data. (orig.)

  3. Stationary electromagnetic fields of slowly rotating relativistic magnetized star in the braneworld

    Science.gov (United States)

    Turimov, B. V.; Ahmedov, B. J.; Hakimov, A. A.

    2017-11-01

    The exterior electromagnetic fields of slowly rotating relativistic magnetized star in the braneworld are studied in detail. We have also obtained exact analytical solutions of the Maxwell equations for the magnetic and the electric fields inside the slowly rotating relativistic magnetized star in the braneworld. The dependence of the electromagnetic energy losses of the rotating magnetized star from the brane tension is also calculated and has been combined with the astrophysical data on pulsar period slowdown in order to get constraints on the brane parameter. We have found the upper limit for the brane parameter as |Q*|≲3 ×1011 cm2.

  4. Association between electromagnetic field exposure and abortion in pregnant women living in Tehran

    Science.gov (United States)

    Abad, Masoumeh; Malekafzali, Hossein; Simbar, Masoumeh; Seyed Mosaavi, Hassan; Merghati Khoei, Effat

    2016-01-01

    Background: Health-related quality of life is affected by electromagnetic field exposure in each person everyday life. However, this is extremely controversial issue. Objective: Investigation of the associations between electromagnetic field exposure and miscarriage among women of Tehran. Materials and Methods: In this longitudinal study, 462 pregnant women with gestational age <12 wks from seven main regions of Tehran city in Iran with similar social and cultural status were participated. Women were interviewed face-to face to collect data. Reproductive information was collected using medical file recorded in those hospitals the subjects had delivery. The measuring device measured electromagnetic waves, Narda safety test solutions with valid calibration date at the entrance door of their houses. Results: A significant likelihood of miscarriage in women who exposed to significant level of electromagnetic wave. However, this association was not confirmed by Wald test. Conclusion: This study may not provide strong or consistent evidence that electromagnetic field exposure is associated or cause miscarriage. This issue may be due to small sample size in this study. PMID:27326421

  5. A New Energy Conservation Law for Time-Harmonic Electromagnetic Fields and Its Applications

    CERN Document Server

    Geyi, Wen

    2016-01-01

    We report a new energy conservation law for time-harmonic electromagnetic fields, which is valid for an arbitrary medium. In contrast to the well-established Poynting theorem for time-harmonic fields, the real part of the new energy conservation law gives an equation for the sum of stored electric and magnetic field energies and the imaginary part involves an equation related to the difference between the dissipated electric and magnetic energies. Universally applicable expressions for both the electric and magnetic field energies have been obtained and demonstrated to be valuable in characterizing the energy storage and transport properties in complex media. For a lossless isotropic and homogeneous medium, the new energy conservation law implies that the stored electromagnetic field energy of a radiating system enclosed by a surface is equal to the total field energy inside the surface subtracted by the energy flowing out of the surface.

  6. The therapeutic effect of a pulsed electromagnetic field on the reproductive patterns of male Wistar rats exposed to a 2.45-GHz microwave field

    Directory of Open Access Journals (Sweden)

    Sanjay Kumar

    2011-01-01

    Full Text Available INTRODUCTION: Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields. OBJECTIVES: This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz on the reproductive systems of male Wistar rats (70 days old. METHODS: The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz, pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays. RESULTS: The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents. CONCLUSIONS: Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.

  7. Modeling and Measurement of Electromagnetic Fields Near LORAN-C and OMEGA Stations

    Science.gov (United States)

    1987-06-15

    magnetic fields on the embryological development of fertilized chicken eggs. This effect was first reported by Delgado, et. al., (30) in 1982 and has since... Embryological Changes Induced by Weak, Extremely Low Frequency Electromagnetic Fields, J.Anat., 134, 533, 1982. 31. Ubeda, A., Leal, J., Trillo, M.A...experiments. One example is the finding that weak pulsed magnetic fields can induce embroyological changes in chicken eggs (30) (31). Some of the results

  8. Convergence of Approximate Potential Functions for Vector Field in Electromagnetic Waveguides

    OpenAIRE

    Kubo, Hiroshi; Yasumoto, Kiyotoshi

    1994-01-01

    The convergence of an approximate electric and an approximate magnetic potential function representing vector field in electromagnetic waveguides is discussed. The two potential functions are expressed in the form of integral of Green's functions and the boundary values of the vector field. Based on these expressions, it is proved that two approximate potential functions converge uniformly to their true potential functions, respectively, when the approximate field satisfies the boundary condi...

  9. Electromagnetic source localization in shallow waters using Bayesian matched-field inversion

    Science.gov (United States)

    Birsan, Marius

    2006-02-01

    The propagation of an electromagnetic signal in a marine environment cannot be modelled as a plane wave due to the high attenuation in seawater and the interactions with the ocean boundaries. Consequently, conventional beamforming techniques are not applicable for electromagnetic source localization. In this work, the Bayesian approach to matched-field processing is used to localize an electromagnetic source and estimate the environmental parameters. In this formulation, the solution to the inverse problem is given by the a posteriori probability distribution calculated here using the Gibbs sampling method. Bayesian inversion theory provides the formalism for estimating parameters, their uncertainties and verification of the estimates convergence. Two situations were investigated for the case where the single frequency measurements represent the magnitudes of two orthogonal horizontal electric field components: (1) all environmental parameters known and (2) unknown seabed conductivity. The objective function that relates the array data to the propagation model and environment parameters was chosen for the practical situation considered.

  10. analysis of large electromagnetic pulse simulators using the electric field integral equation method in time domain

    CERN Document Server

    Jamali, J; Moini, R; Sadeghi, H

    2002-01-01

    A time-domain approach is presented to calculate electromagnetic fields inside a large Electromagnetic Pulse (EMP) simulator. This type of EMP simulator is used for studying the effect of electromagnetic pulses on electrical apparatus in various structures such as vehicles, a reoplanes, etc. The simulator consists of three planar transmission lines. To solve the problem, we first model the metallic structure of the simulator as a grid of conducting wires. The numerical solution of the governing electric field integral equation is then obtained using the method of moments in time domain. To demonstrate the accuracy of the model, we consider a typical EMP simulator. The comparison of our results with those obtained experimentally in the literature validates the model introduced in this paper.

  11. The pH measurement with glass electrode in an electromagnetic field

    Directory of Open Access Journals (Sweden)

    Veselinović Dragan

    2016-01-01

    Full Text Available Measurements of pH values of buffer solutions (pH 4.0, 7.0 and 10.0 and distilled water have been performed with a glass electrode in electromagnetic field at the frequency interval of 10 MHz to 200 MHz and the output power of dispersed and reflected electromagnetic radiation of 0.01 W to 3 W. In all the cases, there occurred a reduction of pH values, i.e. a "recorded pH value" was obtained. The reduction appears within the applied frequency interval reaching extreme values at specific frequencies. The reduction of the pH values increases with the radiation power and depend of the solution buffer capacity. The effect of electromagnetic field on pH value change is exerted dominantly through the influence on glass electrodes.

  12. Differential equations problem solver

    CERN Document Server

    Arterburn, David R

    2012-01-01

    REA's Problem Solvers is a series of useful, practical, and informative study guides. Each title in the series is complete step-by-step solution guide. The Differential Equations Problem Solver enables students to solve difficult problems by showing them step-by-step solutions to Differential Equations problems. The Problem Solvers cover material ranging from the elementary to the advanced and make excellent review books and textbook companions. They're perfect for undergraduate and graduate studies.The Differential Equations Problem Solver is the perfect resource for any class, any exam, and

  13. Radiation pressure and the linear momentum of the electromagnetic field

    CERN Document Server

    Mansuripur, Masud

    2013-01-01

    We derive the force of the electromagnetic radiation on material objects by a direct application of the Lorentz law of classical electro-dynamics. The derivation is straightforward in the case of solid metals and solid dielectrics, where the mass density and the optical constants of the media are assumed to remain unchanged under internal and external pressures, and where material flow and deformation can be ignored. For metallic mirrors, we separate the contribution to the radiation pressure of the electrical charge density from that of the current density of the conduction electrons. In the case of dielectric media, we examine the forces experienced by bound charges and currents, and determine the contribution of each to the radiation pressure. These analyses reveal the existence of a lateral radiation pressure inside the dielectric media, one that is exerted at and around the edges of a finite-diameter light beam. The lateral pressure turns out to be compressive for s-polarized light and expansive for p-po...

  14. Direct Visualization of Local Electromagnetic Field Structures by Scanning Transmission Electron Microscopy.

    Science.gov (United States)

    Shibata, Naoya; Findlay, Scott D; Matsumoto, Takao; Kohno, Yuji; Seki, Takehito; Sánchez-Santolino, Gabriel; Ikuhara, Yuichi

    2017-07-18

    The functional properties of materials and devices are critically determined by the electromagnetic field structures formed inside them, especially at nanointerface and surface regions, because such structures are strongly associated with the dynamics of electrons, holes and ions. To understand the fundamental origin of many exotic properties in modern materials and devices, it is essential to directly characterize local electromagnetic field structures at such defect regions, even down to atomic dimensions. In recent years, rapid progress in the development of high-speed area detectors for aberration-corrected scanning transmission electron microscopy (STEM) with sub-angstrom spatial resolution has opened new possibilities to directly image such electromagnetic field structures at very high-resolution. In this Account, we give an overview of our recent development of differential phase contrast (DPC) microscopy for aberration-corrected STEM and its application to many materials problems. In recent years, we have developed segmented-type STEM detectors which divide the detector plane into 16 segments and enable simultaneous imaging of 16 STEM images which are sensitive to the positions and angles of transmitted/scattered electrons on the detector plane. These detectors also have atomic-resolution imaging capability. Using these segmented-type STEM detectors, we show DPC STEM imaging to be a very powerful tool for directly imaging local electromagnetic field structures in materials and devices in real space. For example, DPC STEM can clearly visualize the local electric field variation due to the abrupt potential change across a p-n junction in a GaAs semiconductor, which cannot be observed by normal in-focus bright-field or annular type dark-field STEM imaging modes. DPC STEM is also very effective for imaging magnetic field structures in magnetic materials, such as magnetic domains and skyrmions. Moreover, real-time imaging of electromagnetic field structures can

  15. Electromagnetic Field in Anechoic and EMC Chambers - Part I - Modelling

    Directory of Open Access Journals (Sweden)

    P. Pechac

    2000-04-01

    Full Text Available Anechoic and EMC chamber at the CTU in Prague was designed and used fora variety of antenna measurements and EMI testing. Due to differentmeasurement methods (near field, far field, compact range, and EMImeasurement applied in the laboratory, different simulations wereperformed during the design process.

  16. Electromagnetic Field in Anechoic and EMC Chambers - Part I - Modelling

    OpenAIRE

    Mazanek, M.; Klepal, M.; Pechač, Pavel

    2000-01-01

    Anechoic and EMC chamber at the CTU in Prague was designed and used for a variety of antenna measurements and EMI testing. Due to different measurement methods (near field, far field, compact range, and EMI measurement) applied in the laboratory, different simulations were performed during the design process.

  17. Electromagnetic field calculation for 110 kV power line

    Directory of Open Access Journals (Sweden)

    Berzan V.

    2015-08-01

    Full Text Available The paper studies the evolution of values for the characteristic electric field and magnetic field generated by power line voltages and currents voltage 110 kV their value based snapshots. These evolutions we examined in changing the value of the angle of the voltage vector and current vector within 0o...180o. The conductors are placed horizontally and triangle tops with different lengths of the sides. The electric field distribution was calculated with finite volume method. Since the electric field distributions were determined parameter values of LEA110 kV. The values of the line parameters, which were determined by the finite volume method, difference from the values calculated by the traditional method. In this context finite volume method presents attractive enough to determine the parameters of power lines and spatial distribution of the electric field in three-phase lines.

  18. Fermi condensates for dynamic imaging of electromagnetic fields.

    Science.gov (United States)

    Koponen, T K; Pasanen, J; Törmä, P

    2009-04-24

    Ultracold gases provide micrometer size samples whose sensitivity to external fields may be exploited in sensor applications. Bose-Einstein condensates of atomic gases have been demonstrated to perform excellently as magnetic field sensors in atom chips. Here we propose that condensates of fermions can be used for noninvasive sensing of time-dependent and static magnetic and electric fields, by utilizing the tunable energy gap in the excitation spectrum as a frequency filter. Perturbations by the field create collective excitations and quasiparticles. The latter requires the frequency of the perturbation to exceed the gap. The frequencies of the field may be selectively monitored from the amount of quasiparticles which is measurable, e.g., by rf spectroscopy. We analyze the method by calculating the density-density susceptibility and discuss its sensitivity and spatial resolution.

  19. Quantitative 3D electromagnetic field determination of 1D nanostructures from single projection

    Energy Technology Data Exchange (ETDEWEB)

    Phatak, C., E-mail: cd@anl.gov [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Knoop, L. de; Houdellier, F.; Gatel, C. [CEMES-CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse (France); Université Paul Sabatier, F-31000 Toulouse (France); Hÿtch, M.J.; Masseboeuf, A. [CEMES-CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse (France)

    2016-05-15

    One-dimensional (1D) nanostructures have been regarded as the most promising building blocks for nanoelectronics and nanocomposite material systems as well as for alternative energy applications. Although they result in confinement of a material, their properties and interactions with other nanostructures are still very much three-dimensional (3D) in nature. In this work, we present a novel method for quantitative determination of the 3D electromagnetic fields in and around 1D nanostructures using a single electron wave phase image, thereby eliminating the cumbersome acquisition of tomographic data. Using symmetry arguments, we have reconstructed the 3D magnetic field of a nickel nanowire as well as the 3D electric field around a carbon nanotube field emitter, from one single projection. The accuracy of quantitative values determined here is shown to be a better fit to the physics at play than the value obtained by conventional analysis. Moreover the 3D reconstructions can then directly be visualized and used in the design of functional 3D architectures built using 1D nanostructures. - Highlights: • Novel method for tomography of 3D electromagnetic fields from a single image is presented. • The method relies upon using cylindrical symmetry and is applied to 1D nanostructures. • The 3D magnetic field of a Nickel nanowire is reconstructed. • The 3D electric field from a biased carbon cone nanotip is reconstructed. • Our method improves the quantitative measurement of the 3D electromagnetic fields.

  20. Effects of electromagnetic fields on proteoglycan metabolism of bovine articular cartilage explants

    NARCIS (Netherlands)

    De Mattei, M; Pasello, M; Pellati, A; Stabellini, G; Massari, L; Gemmati, D; Caruso, A

    2003-01-01

    Electromagnetic field (EMF) exposure has been proposed for the treatment of osteoarthritis. In this study, we investigated the effects of EMF (75 Hz, 2,3 mT) on proteoglycan (PG) metabolism of bovine articular cartilage explants cultured in vitro, both under basal conditions and in the presence of

  1. Effects of electromagnetic field of 33 and 275 kv influences on ...

    African Journals Online (AJOL)

    user

    2012-08-16

    Aug 16, 2012 ... 3School of Biological Sciences, Universiti Sains Malaysia, Minden Heights, 11800 Penang, Malaysia. Accepted 11 June, 2012. The effects of electromagnetic fields (EMF) from 33 and 275 kV high voltage transmission line on biochemical and antioxidant system changes in mustard leaf (Brassica chinensis) ...

  2. Residential characteristics and radiofrequency electromagnetic field exposures from bedroom measurements in Germany

    DEFF Research Database (Denmark)

    Breckenkamp, J; Blettner, M; Schüz, J

    2012-01-01

    The objectives of this study were to assess total exposure to radiofrequency electromagnetic fields (RF-EMF) in bedrooms and the contribution of different radioservices (FM radio, analogue TV and DVB-T, TETRA, GSM900 downlink, GSM1800 downlink, UMTS downlink, DECT, and wireless LAN and blue tooth...

  3. Electromagnetic Fields, Pulsed Radiofrequency Radiation, and Epigenetics: How Wireless Technologies May Affect Childhood Development

    Science.gov (United States)

    Sage, Cindy; Burgio, Ernesto

    2018-01-01

    Mobile phones and other wireless devices that produce electromagnetic fields (EMF) and pulsed radiofrequency radiation (RFR) are widely documented to cause potentially harmful health impacts that can be detrimental to young people. New epigenetic studies are profiled in this review to account for some neurodevelopmental and neurobehavioral changes…

  4. Effects of 1.84 GHz radio-frequency electromagnetic field on sperm ...

    African Journals Online (AJOL)

    sunny t

    Full Length Research Paper. Effects of 1.84 GHz radio-frequency electromagnetic field on sperm maturation in epididymis micro- environment. Guangzhou An1*, Jing Li1, Shenglong Xu1, Tao Zhao1, Kangchu Li1, Jiajin Lin1, Yan Zhou1,. Lihua Zeng2, Guozhen Guo2 and Guirong Ding1. 1Department of Radiation Biology, ...

  5. [Risk of electromagnetic fields in electric power stations and substations of a petrochemical plant].

    Science.gov (United States)

    Castagnoli, A; Fabri, G; Romeo, A

    2003-01-01

    Authors evaluate electromagnetic field exposure in the low-frequency range (5-30,000 Hz) in electric power stations and substations of petroleum processing plant. According to the measured values and the reference exposure limits considered, they conclude that operators should be exposed without adverse effects.

  6. Scattering of electromagnetic waves by charged spheres: near-field external intensity distribution.

    Science.gov (United States)

    Kocifaj, Miroslav; Klačka, Jozef

    2012-01-15

    This Letter treats the scattering of electromagnetic waves by an electrically charged spherical particle in near-field approximation. Particular attention is paid to the external intensity distribution at the outer edges of the particle. The difference between scattering by a charged sphere and an electrically neutral sphere is significant only when size parameters exceed unity.

  7. Near field computation of the extinction of electromagnetic waves in multiparticle systems

    Directory of Open Access Journals (Sweden)

    J. Schaefer

    2011-09-01

    Full Text Available In this contribution extinction of electromagnetic waves inside a medium consisting of cylindrical absorbing particles is considered. Near fields are calculated using a numerical solution of Maxwell’s equations and compared to results given by Lambert- Beer’s law.

  8. Apparent paradoxes in classical electrodynamics: a fluid medium in an electromagnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kholmetskii, A L [Department of Physics, Belarusian State University, 4, Nezavisimosti Avenue, 220050 Minsk Belarus (Belarus); Yarman, T [Department of Engineering, Okan University Istanbul, Turkey and Savronik, Eskisehir (Turkey)], E-mail: kholm@bsu.by

    2008-11-15

    In this paper we analyse a number of teaching paradoxes of classical electrodynamics, dealing with the relativistic transformation of energy and momentum for a fluid medium in an external electromagnetic field. In particular, we consider a moving parallel plate charged capacitor, where the electric attraction of its plates is balanced by the pressure of gas convicted between the plates.

  9. Biological Effects of Weak Electromagnetic Field on Healthy and Infected Lime (Citrus aurantifolia Trees with Phytoplasma

    Directory of Open Access Journals (Sweden)

    Fatemeh Abdollahi

    2012-01-01

    Full Text Available Exposure to electromagnetic fields (EMF has become an issue of concern for a great many people and is an active area of research. Phytoplasmas, also known as mycoplasma-like organisms, are wall-less prokaryotes that are pathogens of many plant species throughout the world. Effects of electromagnetic fields on the changes of lipid peroxidation, content of H2O2, proline, protein, and carbohydrates were investigated in leaves of two-year-old trees of lime (Citrus aurantifolia infected by the Candidatus Phytoplasma aurantifoliae. The healthy and infected plants were discontinuously exposed to a 10 KHz quadratic EMF with maximum power of 9 W for 5 days, each 5 h, at 25°C. Fresh and dry weight of leaves, content of MDA, proline, and protein increased in both healthy and infected plants under electromagnetic fields, compared with those of the control plants. Electromagnetic fields decreased hydrogen peroxide and carbohydrates content in both healthy and infected plants compared to those of the controls.

  10. Biological effects of weak electromagnetic field on healthy and infected lime (Citrus aurantifolia) trees with phytoplasma.

    Science.gov (United States)

    Abdollahi, Fatemeh; Niknam, Vahid; Ghanati, Faezeh; Masroor, Faribors; Noorbakhsh, Seyyed Nasr

    2012-01-01

    Exposure to electromagnetic fields (EMF) has become an issue of concern for a great many people and is an active area of research. Phytoplasmas, also known as mycoplasma-like organisms, are wall-less prokaryotes that are pathogens of many plant species throughout the world. Effects of electromagnetic fields on the changes of lipid peroxidation, content of H(2)O(2), proline, protein, and carbohydrates were investigated in leaves of two-year-old trees of lime (Citrus aurantifolia) infected by the Candidatus Phytoplasma aurantifoliae. The healthy and infected plants were discontinuously exposed to a 10 KHz quadratic EMF with maximum power of 9 W for 5 days, each 5 h, at 25 °C. Fresh and dry weight of leaves, content of MDA, proline, and protein increased in both healthy and infected plants under electromagnetic fields, compared with those of the control plants. Electromagnetic fields decreased hydrogen peroxide and carbohydrates content in both healthy and infected plants compared to those of the controls.

  11. Modelling indoor electromagnetic fields (EMF) from mobile phone base stations for epidemiological studies

    NARCIS (Netherlands)

    Beekhuizen, J.; Vermeulen, R.; van Eijsden, M.; van Strien, R.; Bürgi, A.; Loomans, E.; Guxens, M.; Kromhout, H.; Huss, A.

    2014-01-01

    Radio frequency electromagnetic fields (RF-EMF) from mobile phone base stations can be reliably modelled for outdoor locations, using 3D radio wave propagation models that consider antenna characteristics and building geometry. For exposure assessment in epidemiological studies, however, it is

  12. ANALYSIS OF ELECTROMAGNETIC FIELDS AND NOISE IN THE AREA OF AGRICUL-TURAL BIOGAS PLANT

    Directory of Open Access Journals (Sweden)

    Paweł A. Mazurek

    2016-12-01

    Full Text Available Electro-magnetic and acoustic fields were analysed at the bioenergy and biogas production plant of 0.999 MW operational power, localized in Piaski. Measured values were compared with valid national norms and did not exceed limiting values in zones of people’s permanent residence.

  13. Semi-quantitative proteomics of mammalian cells upon short-term exposure to nonionizing electromagnetic fields

    NARCIS (Netherlands)

    Kuzniar, A. (Arnold); C. Laffeber; B. Eppink (Berina); K. Bezstarosti (Karel); D.H. Dekkers (Dick); H. Woelders (Henri); A.P.M. Zwamborn; J.A.A. Demmers (Jeroen); J.H.G. Lebbink (Joyce); R. Kanaar (Roland)

    2017-01-01

    textabstractThe potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated.

  14. Semi-quantitative proteomics of mammalian cells upon short-term exposure to nonionizing electromagnetic fields

    NARCIS (Netherlands)

    Kuzniar, A.; Laffeber, C.; Eppink, B.; Bezstarosti, K.; Dekkers, D.; Woelders, H.; Zwamborn, A.P.M.; Demmers, J.; Lebbink, J.H.G.; Kanaar, R.

    2017-01-01

    The potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated. However, how

  15. Semi-quantitative proteomics of mammalian cells upon short-term exposure to nonionizing electromagnetic fields

    NARCIS (Netherlands)

    Kuzniar, Arnold; Laffeber, Charlie; Eppink, Berina; Bezstarosti, Karel; Dekkers, Dick; Woelders, Henri; Zwamborn, A.P.M.; Demmers, Jeroen; Lebbink, Joyce H.G.; Kanaar, Roland

    2017-01-01

    The potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated. However,

  16. Electrical Engineers' Perceptions on Education--Electromagnetic Field Theory and Its Connection to Working Life

    Science.gov (United States)

    Keltikangas, K.; Wallen, H.

    2010-01-01

    This paper investigates electrical engineers' perceptions on their education in Finland, with particular emphasis on the basic electromagnetic field theory courses and their applicability in working life, using two online surveys (n = 99 and n = 120). The answers show a reasonably good satisfaction with the electrical engineering studies in…

  17. Stimulation of osteogenic differentiation in human osteoprogenitor cells by pulsed electromagnetic fields: An in vitro study

    NARCIS (Netherlands)

    J.H.W. Jansen (Justus); O.P. van der Jagt (Olav); B.J. Punt (Bas); J.A.N. Verhaar (Jan); J.P.T.M. van Leeuwen (Hans); H.H. Weinans (Harrie); H. Jahr (Holger)

    2010-01-01

    textabstractBackground: Although pulsed electromagnetic field (PEMF) stimulation may be clinically beneficial during fracture healing and for a wide range of bone disorders, there is still debate on its working mechanism. Mesenchymal stem cells are likely mediators facilitating the observed clinical

  18. The Role of Angular Momentum in the Construction of Electromagnetic Multipolar Fields

    Science.gov (United States)

    Tischler, Nora; Zambrana-Puyalto, Xavier; Molina-Terriza, Gabriel

    2012-01-01

    Multipolar solutions of Maxwell's equations are used in many practical applications and are essential for the understanding of light-matter interactions at the fundamental level. Unlike the set of plane wave solutions of electromagnetic fields, the multipolar solutions do not share a standard derivation or notation. As a result, expressions…

  19. Waves of change: immunomodulation of the innate immune response by low frequency electromagnetic field exposure

    NARCIS (Netherlands)

    Golbach, L.A.

    2015-01-01

      In this thesis we investigated possible modulatory roles of low frequency electromagnetic fields (LF EMFs) exposure on the innate immune system. Recent decades have seen a huge increase in the use of electronic devices that nowadays enable us to communicate with distant family, enjoy music

  20. Terahertz Solitons in Biomolecular Systems and their Excitation by External Electromagnetic Field

    Directory of Open Access Journals (Sweden)

    Bugay А.N.

    2015-01-01

    Full Text Available Nonlinear dynamics of charge and acoustic excitations in cellular microtubules is considered. Different types of nonlinear solitary waves were studied taking account for dissipation. The mechanism of electro-acoustic pulse excitation by external electromagnetic field of terahertz frequency is recognized.

  1. Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF): A systematic review of identifying criteria

    NARCIS (Netherlands)

    Baliatsas, C.; van Kamp, I.; Lebret, E.; Rubin, J.G.

    2012-01-01

    ABSTRACT: BACKGROUND: Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) remains a complex and unclear phenomenon, often characterized by the report of various, non-specific physical symptoms (NSPS) when an EMF source is present or perceived by the individual. The

  2. What input data are needed to accurately model electromagnetic fields from mobile phone base stations?

    NARCIS (Netherlands)

    Beekhuizen, Johan; Kromhout, Hans; Bürgi, Alfred; Huss, Anke; Vermeulen, Roel

    The increase in mobile communication technology has led to concern about potential health effects of radio frequency electromagnetic fields (RF-EMFs) from mobile phone base stations. Different RF-EMF prediction models have been applied to assess population exposure to RF-EMF. Our study examines what

  3. Systemic treatment with pulsed electromagnetic fields do not affect bone microarchitecture in osteoporotic rats

    NARCIS (Netherlands)

    O.P. van der Jagt (Olav); J.C. van der Linden (Jacqueline); J.H. Waarsing (Jan); J.A.N. Verhaar (Jan); H.H. Weinans (Harrie)

    2012-01-01

    textabstractPurpose: Pulsed electromagnetic fields (PEMF) are currently used in the treatment of spinal fusions and non-unions. There are indications that PEMF might also be effective in the treatment of osteoporosis. In this study we examined whether whole-body PEMF treatment affects the bone

  4. Controlling electromagnetic fields at boundaries of arbitrary geometries

    Science.gov (United States)

    Teo, Jonathon Yi Han; Wong, Liang Jie; Molardi, Carlo; Genevet, Patrice

    2016-08-01

    Rapid developments in the emerging field of stretchable and conformable photonics necessitate analytical expressions for boundary conditions at metasurfaces of arbitrary geometries. Here, we introduce the concept of conformal boundary optics: a design theory that determines the optical response for designer input and output fields at such interfaces. Given any object, we can realize coatings to achieve exotic effects like optical illusions and anomalous diffraction behavior. This approach is relevant to a broad range of applications from conventional refractive optics to the design of the next-generation of wearable optical components. This concept can be generalized to other fields of research where designer interfaces with nontrivial geometries are encountered.

  5. The assessment of electromagnetic field radiation exposure for mobile phone users.

    Science.gov (United States)

    Buckus, Raimondas; Strukcinskiene, Birute; Raistenskis, Juozas

    2014-12-01

    During recent years, the widespread use of mobile phones has resulted in increased human ex- posure to electromagnetic field radiation and to health risks. Increased usage of mobile phones at the close proximity raises questions and doubts in safety of mobile phone users. The aim of the study was to assess an electromagnetic field radiation exposure for mobile phone users by measuring electromagnetic field strength in different settings at the distance of 1 to 30 cm from the mobile user. In this paper, the measurements of electric field strength exposure were conducted on different brand of mobile phones by the call-related factors: urban/rural area, indoor/outdoor setting and moving/stationary mode during calls. The different types of mobile phone were placed facing the field probe at 1 cm, 10 cm, 20 cm and 30 cm distance. The highest electric field strength was recorded for calls made in rural area (indoors) while the lowest electric field strength was recorded for calls made in urban area (outdoors). Calls made from a phone in a moving car gave a similar result like for indoor calls; however, calls made from a phone in a moving car exposed electric field strength two times more than that of calls in a standing (motionless) position. Electromagnetic field radiation depends on mobile phone power class and factors, like urban or rural area, outdoor or indoor, moving or motionless position, and the distance of the mobile phone from the phone user. It is recommended to keep a mobile phone in the safe distance of 10, 20 or 30 cm from the body (especially head) during the calls.

  6. The assessment of electromagnetic field radiation exposure for mobile phone users

    Directory of Open Access Journals (Sweden)

    Buckus Raimondas

    2014-01-01

    Full Text Available Background/Aim. During recent years, the widespread use of mobile phones has resulted in increased human exposure to electromagnetic field radiation and to health risks. Increased usage of mobile phones at the close proximity raises questions and doubts in safety of mobile phone users. The aim of the study was to assess an electromagnetic field radiation exposure for mobile phone users by measuring electromagnetic field strength in different settings at the distance of 1 to 30 cm from the mobile user. Methods. In this paper, the measurements of electric field strength exposure were conducted on different brand of mobile phones by the call-related factors: urban/rural area, indoor/outdoor setting and moving/stationary mode during calls. The different types of mobile phone were placed facing the field probe at 1 cm, 10 cm, 20 cm and 30 cm distance. Results. The highest electric field strength was recorded for calls made in rural area (indoors while the lowest electric field strength was recorded for calls made in urban area (outdoors. Calls made from a phone in a moving car gave a similar result like for indoor calls; however, calls made from a phone in a moving car exposed electric field strength two times more than that of calls in a standing (motionless position. Conclusion. Electromagnetic field radiation depends on mobile phone power class and factors, like urban or rural area, outdoor or indoor, moving or motionless position, and the distance of the mobile phone from the phone user. It is recommended to keep a mobile phone in the safe distance of 10, 20 or 30 cm from the body (especially head during the calls.

  7. Electromagnetic field interactions with the human body: Observed effects and theories

    Science.gov (United States)

    Raines, J. K.

    1981-01-01

    The effects of nonionizing electromagnetic (EM) field interactions with the human body were reported and human related studies were collected. Nonionizing EM fields are linked to cancer in humans in three different ways: cause, means of detection, and effective treatment. Bad and benign effects are expected from nonionizing EM fields and much more knowledge is necessary to properly categorize and qualify EM field characteristics. It is concluded that knowledge of the boundary between categories, largely dependent on field intensity, is vital to proper future use of EM radiation for any purpose and the protection of the individual from hazard.

  8. On the scalar particle creation by electromagnetic fields in Robertson–Walker spacetime

    Directory of Open Access Journals (Sweden)

    Kenan Sogut

    2015-12-01

    Full Text Available In the present paper, we obtained the scalar particle creation number density by using the Klein–Gordon equation coupled to the electromagnetic fields in the Robertson–Walker spacetime with the help of the Bogoliubov transformation method. We analyzed the resulting expression for the effect of a time-dependent electric field and a constant magnetic field on the particle production rate and found that the strong time-dependent electric field amplifies the particle creation and the magnetic field reduces the rate, in accordance with the previous findings.

  9. Generalizations of the Smarr formula for black holes with nonlinear electromagnetic fields

    Science.gov (United States)

    Gulin, Luka; Smolić, Ivica

    2018-01-01

    We present a direct, geometric derivation of the generalized Smarr formula for the stationary axially symmetric black holes with nonlinear electromagnetic fields. The additional term is proven to be proportional to the integral of the trace of the electromagnetic energy-momentum tensor and can be written as a product of two conjugate variables. From the novel relation we can deduce all previously proposed forms of the generalized Smarr formula, which were derived only for the spherically symmetric black holes, and provide the lowest order quantum correction to the classical relation from the Euler–Heisenberg Lagrangian.

  10. Electromagnetic Field Interaction With Transmission Lines From Classical Theory to HF Radiation Effects

    CERN Document Server

    Tkachenko, Sergey V

    2008-01-01

    The evaluation of the electromagnetic field coupling to transmission lines is an important problem in electromagnetic compatibility. The unabated increase in the operating frequency of electronic products and the emergence of sources of disturbances with higher frequency content (such as High Power Microwave and Ultra-Wide Band systems) have led to a breakdown of the TL approximation's basic assumptions for a number of applications. In the last decade or so, the generalization of the TL theory to take into account high frequency effects has emerged as an important topic of study in electromagn

  11. 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 fiel...... 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....

  12. Electromagnetic field effects on cells of the immune system: The role of calcium signaling

    Energy Technology Data Exchange (ETDEWEB)

    Walleczek, J. (Lawrence Berkeley Lab., CA (United States))

    1992-10-01

    During the past decade considerable evidence has accumulated demonstrating that nonthermal exposures of cells of the immune system to extremely low-frequency (ELF) electromagnetic fields (< 300 Hz) can elicit cellular changes that might be relevant to in vivo immune activity. A similar responsiveness to nonionizing electromagnetic energy in this frequency range has also been documented for tissues of the neuroendocrine and musculoskeletal system. However, knowledge about the underlying biological mechanisms by which such fields can induce cellular changes is still very limited. It is generally believed that the cell membrane and Ca[sup 2+]-regulated activity is involved in bioactive ELF field coupling to living systems. This article begins with a short review of the current state of knowledge concerning the effects of nonthermal levels of ELF electromagnetic fields on the biochemistry and activity of immune cells and then closely examines new results that suggest a role for Ca[sup 2+] in the induction of these cellular field effects. Based on these findings it is proposed that membrane-mediated Ca[sup 2+] in the induction of these cellular field effects. Based on these findings it is proposed that membrane-mediated Ca[sup 2+] signaling processes are involved in the mediation of field effects on the immune system. 69 refs., 2 tabs.

  13. The views of primary care physicians on health risks from electromagnetic fields.

    Science.gov (United States)

    Berg-Beckhoff, Gabriele; Heyer, Kristina; Kowall, Bernd; Breckenkamp, Jürgen; Razum, Oliver

    2010-11-01

    The aim of this study was to find out what primary care physicians in Germany think about the possible health risks of electromagnetic fields (EMF) and how they deal with this topic in discussions with patients. Questionnaires were mailed to a nationwide, representative sample drawn from the regional associations of statutory health insurance physicians in Germany, consisting of 2795 primary care physicians (7% random sample of the total number in the country). 435 of them returned four-page questionnaires (response rate, 23.3%), and 456 returned a one-page questionnaire (response rate, 49.1%). They were asked about their views on the health risks of electromagnetic fields and about their experience with patients on this topic. 61.4% of the primary care physicians reported having discussed the possible health risks of electromagnetic fields with at least one patient. In 73.4% of these discussions, the patient raised the subject first and presumed that such risks do, in fact, exist. Among all discussions in which the patient expressed this concern, the physician considered the association to be plausible only 24.1% of the time. In half of all consultations in which EMF was discussed as a possible danger, the physician recommended some type of protective measure. The most frequent recommendation was to remove electrical equipment; the second most frequent, to move to another location. The physicians' answers to the questionnaires revealed a poor knowledge of the properties and risks of electromagnetic fields. Primary care physicians often discuss the putative health risks of electromagnetic fields with their patients, yet their recommendations very often are not evidence-based and might have major consequences in their patients' lives.

  14. 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.

  15. [Suppression of tumor immunity by electromagnetic fields and glucocorticoids in mice with implanted Ehrlich carcinoma].

    Science.gov (United States)

    Knezević, Dusko

    2005-01-01

    The immune system plays a major role in the origin, growth and evolution of tumors; factors that decrease the immune response in any way can cause higher tumor incidence and its faster or uncontrolled growth and evolution. The research included 18 healthy male Han: NMRI mice, weighing between 25 and 30g, with ten-day-old tumor deposits, divided into three groups consisting of six mice each. The first group was continuously exposed to extremely low frequency electromagnetic fields (intensity 70-320 microT). The second group was treated with high doses of corticosteroids (dexamethasone). The control group was not treated with corticosteroids, nor was exposed to extremely low frequency electromagnetic fields. The exposure period lasted for ten days. The criteria used to evaluate tumor immunity were: histological findings of leukocyte infiltration around the tumor cells and white blood cell count. The control group presented with excellent immune response to tumor cells. Lymphoplasmacytic infiltrates widely surrounded the tumor. Numerous tumor cells showed signs of cell death. The results showed that exposure of animals to high doses of glucocorticoids resulted in extremely decreased leukocyte infiltration in the tumor tissue (single lymphocytes), while exposure to extremely low frequency electromagnetic fields significantly decreased leukocyte infiltration in comparison to the control group. Comparison of white blood cell count in treated groups revealed that the white blood cell count in both treated groups was decreased, compared with the control group. Extremely low frequency electromagnetic fields significantly suppress the immune response to tumor cells. Dexamethasone treatment resulted in almost complete absence of immune response to tumor cells. Electromagnetic fields and dexamethasone both decrease the white blood cell count.

  16. Propagation of electromagnetic waves parallel to the magnetic field in the nightside Venus ionosphere

    Science.gov (United States)

    Huba, J. D.; Rowland, H. L.

    1993-01-01

    The propagation of electromagnetic waves parallel to the magnetic field in the nightside Venus ionosphere is presented in a theoretical and numerical analysis. The model assumes a source of electromagnetic radiation in the Venus atmosphere, such as that produced by lightning. Specifically addressed is wave propagation in the altitude range z = 130-160 km at the four frequencies detectable by the Pioneer Venus Orbiter Electric Field Detector: 100 Hz, 730 Hz, 5.4 kHz, and 30 kHz. Parameterizations of the wave intensities, peak electron density, and Poynting flux as a function of magnetic field are presented. The waves are found to propagate most easily in conditions of low electron density and high magnetic field. The results of the model are consistent with observational data.

  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

    , 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......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...

  18. Electromagnetic fields created by a macroparticle in an infinitely long and axisymmetric multilayer beam pipe

    CERN Document Server

    Mounet, N

    2009-01-01

    This paper aims at giving an as complete and detailed as possible derivation of the six electromagnetic field components created by an offset point charge travelling at any speed in an infinitely long circular multilayer beam pipe. Outcomes from this study are a novel and efficient matrix method for the field matching determination of all the constants involved in the field components, and the generalization to any azimuthal mode together with the final summation on all such modes in the impedance formulas. In particular the multimode direct space-charge impedances (both longitudinal and transverse) are given, as well as the wall impedance to any order of precision. New quadrupolar terms for the transverse wall impedance are found, which look negligible in the ultrarelativistic case but might be of significance for low-energy beams. In principle from this analysis the electromagnetic fields created by any particular source, with a finite transverse shape, can then be computed using convolutions.

  19. Gene transcription and electromagnetic fields. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, A.S.

    1992-12-31

    Our overall aim is to obtain sufficient information to allow us to ultimately determine whether ELF EM field exposure is an initiating factor in neoplastic transformation and/or if exposure can mimic characteristics of the second-step counterpart in neoplastic disease. This aim is based on our previous findings that levels of some transcripts are increased in cells exposed to EM fields. While the research is basic in nature, the ramifications have bearing on the general safety of exposure to EM fields in industrial and everyday life. A large array of diverse biological effects are reported to occur as the result of exposure to elf EM fields, suggesting that the cell response to EM fields is at a basic level, presumably initiated by molecular and/or biophysical events at the cell membrane. The hypothesized route is a signal transduction pathway involving membrane calcium fluxes. Information flow resulting from signal transduction can mediate the induction of regulatory factors in the cell, and directly affect how transcription is regulated.

  20. Numerical Modelling of Electromagnetic Field in a Tornado

    Directory of Open Access Journals (Sweden)

    Pavel Fiala

    2008-01-01

    Full Text Available This study deals with the numerical model of both the physical and the chemical processes in the tornado. Within the paper, a basic theoretical model and a numerical solution are presented. We prepared numerical models based on the combined finite element method (FEM and the finite volume method (FVM. The model joins the magnetic, electric and current fields, the flow field and a chemical nonlinear ion model. The results were obtained by means of the FEM/FVM as a main application in ANSYS software.

  1. Poole-Frenkel Effect in Terahertz Electromagnetic Fields

    OpenAIRE

    Ganichev, Sergey; Diener, J.; Yassievich, Irina; Prettl, Wilhelm

    1995-01-01

    The ionisation of deep impurity centres in germanium has been observed with radiation in the terahertz range where the photon energy is much less than the binding energy of the impurities. It is shown that for not too high radiation intensities the ionisation is caused by the Poole-Frenkel effect. As in the well-known case of d.c. fields, the electric field of the high-frequency radiation lowers the Coulomb potential barrier and enhances the thermal emission of carriers.

  2. Gain of electromagnetic radiation traveling in a semiconductor subjected to magnetic and ultrasonic fields

    Energy Technology Data Exchange (ETDEWEB)

    Aleksanyan, A.G.; Boyakhchyan, G.P.; Mirzabekyan, E.G.

    1979-08-01

    A calculation is made of the gain experienced by an electromagnetic wave in a semiconductor subjected to magnetic field and ultrasonic fields. It is shown that the gain can be 1--500 for a wide range of the parameters. Analytic expressions are obtained for the frequency depencence of the real part of the high-frequency conductivity when the pump power, ultrasonic wavelength, and temperature of the semiconductor are varied.

  3. Pulsed electromagnetic field radiation from a narrow slot antenna with a dielectric layer

    OpenAIRE

    Stumpf, M.; de Hoop, A. T.; Lager, I. E.

    2010-01-01

    Analytic time domain expressions are derived for the pulsed electromagnetic field radiated by a narrow slot antenna with a dielectric layer in a two?dimensional model configuration. In any finite time window of observation, exact pulse shapes for the propagated, reflected, and refracted wave constituents are constructed with the aid of the modified Cagniard method (Cagniard?DeHoop method). Numerical results are presented for vanishing slot width and field pulse shapes at the dielectric/free s...

  4. Electromagnetic Waves Reflectance of Graphene -- Magnetic Semiconductor Superlattice in Magnetic Field

    OpenAIRE

    Kuzmin, Dmitry A.; Bychkov, Igor V.; Shavrov, Vladimir G.

    2014-01-01

    Electrodynamic properties of the graphene - magnetic semiconductor - graphene superlattice placed in magnetic field have been investigated theoretically in Faraday geometry with taking into account dissipation processes. Frequency and field dependences of the reflectance, transmittance and absorbtance of electromagnetic waves by such superlattice have been calculated for different numbers of periods of the structure and different sizes of the periods with using a transfer matrix method. The p...

  5. Second-order Dirac equation of graphene electrons in an electromagnetic field and their novel spin

    OpenAIRE

    Luo, Ji

    2013-01-01

    The second-order Dirac equation (DE) and its velocity operator of graphene electrons in an electromagnetic field are obtained according to tight-binding k.p method. With extra terms included, they demonstrate the motion of graphene electrons more completely through a more complete Ehrenfest theorem and present finer properties of graphene electrons. Eigen-energy given by the second-order DE for field-free graphene indicates that extra terms may affect the trembling motion of graphene electron...

  6. Effects of electromagnetic fields of low frequency and low intensity on rat metabolism

    OpenAIRE

    Gerardi, Gabriele; De Ninno, Antonella; Prosdocimi, Marco; Ferrari, Vanni; Barbaro, Filippo; Mazzariol, Sandro; Bernardini, Daniele; Talpo, Getullio

    2008-01-01

    A series of experiments on rats have been performed, to study the effects of long time (50 days) exposure to electromagnetic fields of extremely low frequency (ELF, i.e. less than 100 Hz) and amplitude (non thermal), testing whether the metabolic processes would be affected. The background lies on recent observations on the behaviour of isolated enzymes in vitro exposed to EFL fields. In these experiments, the cyclotron (or Larmor) frequency of the metallic ion has been used to "stimulate" th...

  7. Static spherically symmetric anisotropic fluid distribution in presence of electromagnetic field

    CERN Document Server

    Mukherjeea, B

    2003-01-01

    Einstein's field equations of general relativity corresponding to the anisotropic (principal stresses unequal) static fluid sphere in presence of electromagnetic field have been solved exactly. The integration constants are determined by matching the obtained solution with the Reissner-Nordstroem solution over the boundary. It has been found that the fluid model has non-negative expression for mass density and pressure. The mass density and stresses are everywhere regular and monotonically decreasing functions of the radial coordinate. (author)

  8. Extremely Low Frequency Electromagnetic Field (ELF-EMF) and childhood leukemia near transmission lines: a review

    OpenAIRE

    P. A. Kokate; A. K. Mishra; S. K. Lokhande; G. L. Bodhe

    2016-01-01

    This article presents a systematic review of most cited studies from developed countries those shed light on the potential relation between childhood leukemia and extremely low frequency electromagnetic field (ELF-EMF). All the findings of articles critically segregated as per some neglected parameters like number of samples, exposure duration, frequency range, distance from the radiation sources, and location during measurement of magnetic field density near power lines. Literature of major ...

  9. IN VITRO CYTOSTATIC EFFECT OF SOME NON-IONIZING ELECTROMAGNETIC FIELDS

    Directory of Open Access Journals (Sweden)

    Cosmin Mihai

    2007-12-01

    model, intensity and type of electromagnetic field, exposure time, metabolic state and type of the exposed cells. This primary characterization of the low intensity and frequency fields as cytostatic agent justifies the study of their effect upon cell proliferation and viability in order to enlarge the reasoning basis for the introduction of this physical agent in the in vivo antitumoral screening program on different experimental tumoral systems.

  10. ELF electro-magnetic fields as stress factors in some yeasts and molds

    Directory of Open Access Journals (Sweden)

    Galonja-Coghill Tamara A.

    2011-01-01

    Full Text Available The possibility of species targeted growth inhibition of three yeast (Candida albicans, Cryptococcus neoformans and Saccharomyces cerevisiae and one mold species (Aspergillus fumigatus by electromagnetic fields of certain characteristics was investigated. Cultures were exposed to sinusoidal 50 Hz fields, and 10, 40 and 70 mT magnetic components and 20 V/m electric component, for 30 minutes. Cell density in yeast cultures and germination time and rate in mold cultures were investigated.

  11. Fractional Calculus-Based Modeling of Electromagnetic Field Propagation in Arbitrary Biological Tissue

    Directory of Open Access Journals (Sweden)

    Pietro Bia

    2016-01-01

    Full Text Available The interaction of electromagnetic fields and biological tissues has become a topic of increasing interest for new research activities in bioelectrics, a new interdisciplinary field combining knowledge of electromagnetic theory, modeling, and simulations, physics, material science, cell biology, and medicine. In particular, the feasibility of pulsed electromagnetic fields in RF and mm-wave frequency range has been investigated with the objective to discover new noninvasive techniques in healthcare. The aim of this contribution is to illustrate a novel Finite-Difference Time-Domain (FDTD scheme for simulating electromagnetic pulse propagation in arbitrary dispersive biological media. The proposed method is based on the fractional calculus theory and a general series expansion of the permittivity function. The spatial dispersion effects are taken into account, too. The resulting formulation is explicit, it has a second-order accuracy, and the need for additional storage variables is minimal. The comparison between simulation results and those evaluated by using an analytical method based on the Fourier transformation demonstrates the accuracy and effectiveness of the developed FDTD model. Five numerical examples showing the plane wave propagation in a variety of dispersive media are examined.

  12. Primary experimental study on safety of deep brain stimulation in RF electromagnetic field.

    Science.gov (United States)

    Jun, Xu; Luming, Li; Hongwei, Hao

    2009-01-01

    With the rapid growth of clinical application of Deep Brain Stimulation, its safety and functional concern in the electromagnetic field, another pollution becoming much more serious, has become more and more significant. Meanwhile, the measuring standards on Electromagnetic Compatibility (EMC) for DBS are still incomplete. Particularly, the knowledge of the electromagnetic field induced signals on the implanted lead is ignorant while some informal reports some side effects. This paper briefly surmised the status of EMC standards on implantable medical devices. Based on the EMC experiments of DBS device we developed, two experiments for measuring the induced voltage of the deep brain stimulator in RF electromagnetic field were reported. The measured data showed that the induced voltage in some frequency was prominent, for example over 2V. As a primary research, we think these results would be significant to cause researcher to pay more attention to the EMC safety problem and biological effects of the induced voltage in deep brain stimulation and other implantable devices.

  13. KeplerSolver: Kepler equation solver

    Science.gov (United States)

    Gürkan, M. Atakan

    2017-06-01

    KeplerSolver solves Kepler's equation for arbitrary epoch and eccentricity, using continued fractions. It is written in C and its speed is nearly the same as the SWIFT routines, while achieving machine precision. It comes with a test program to demonstrate usage.

  14. Comparison of the genotoxic effects induced by 50 Hz extremely low-frequency electromagnetic fields and 1800 MHz radiofrequency electromagnetic fields in GC-2 cells.

    Science.gov (United States)

    Duan, Weixia; Liu, Chuan; Zhang, Lei; He, Mindi; Xu, Shangcheng; Chen, Chunhai; Pi, Huifeng; Gao, Peng; Zhang, Yanwen; Zhong, Min; Yu, Zhengping; Zhou, Zhou

    2015-03-01

    Extremely low-frequency electromagnetic fields (ELF-EMF) and radiofrequency electromagnetic fields (RF-EMF) have been considered to be possibly carcinogenic to humans. However, their genotoxic effects remain controversial. To make experiments controllable and results comparable, we standardized exposure conditions and explored the potential genotoxicity of 50 Hz ELF-EMF and 1800 MHz RF-EMF. A mouse spermatocyte-derived GC-2 cell line was intermittently (5 min on and 10 min off) exposed to 50 Hz ELF-EMF at an intensity of 1, 2 or 3 mT or to RF-EMF in GSM-Talk mode at the specific absorption rates (SAR) of 1, 2 or 4 W/kg. After exposure for 24 h, we found that neither ELF-EMF nor RF-EMF affected cell viability using Cell Counting Kit-8. Through the use of an alkaline comet assay and immunofluorescence against γ-H2AX foci, we found that ELF-EMF exposure resulted in a significant increase of DNA strand breaks at 3 mT, whereas RF-EMF exposure had insufficient energy to induce such effects. Using a formamidopyrimidine DNA glycosylase (FPG)-modified alkaline comet assay, we observed that RF-EMF exposure significantly induced oxidative DNA base damage at a SAR value of 4 W/kg, whereas ELF-EMF exposure did not. Our results suggest that both ELF-EMF and RF-EMF under the same experimental conditions may produce genotoxicity at relative high intensities, but they create different patterns of DNA damage. Therefore, the potential mechanisms underlying the genotoxicity of different frequency electromagnetic fields may be different.

  15. The Electromagnetic Dipole Radiation Field through the Hamiltonian Approach

    Science.gov (United States)

    Likar, A.; Razpet, N.

    2009-01-01

    The dipole radiation from an oscillating charge is treated using the Hamiltonian approach to electrodynamics where the concept of cavity modes plays a central role. We show that the calculation of the radiation field can be obtained in a closed form within this approach by emphasizing the role of coherence between the cavity modes, which is…

  16. Electromagnetic Fields at the Surface of Human-Body Cylinders

    DEFF Research Database (Denmark)

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper

    2016-01-01

    transverse electric and transverse magnetic polarization. The results show that the material assumption when modeling the human body as a homogeneous material is very important. Furthermore, it is shown that one assumption might lead to higher fields for a specific polarization, angle of incidence...

  17. On Acceptable Exposures to Short Pulses of Electromagnetic Fields

    Science.gov (United States)

    2015-09-01

    Nevertheless, Reference 2, Enclosure 3, Part 1c states, “When developing EMF safety programs, do not apply additional safety margins. The MPE limits...the conclusion that there is a risk of harm from nerve excitation up to a half a GHz, for pulses with magnetic fields above the C95.1-2345-2014 limit

  18. Coupled dilaton and electromagnetic field in cylindrically symmetric ...

    Indian Academy of Sciences (India)

    Chamorro and Virb- hadra [7] calculated energy associated with such charged dilaton blackhole solution. Very recently Salim et al [8] considered dilaton field in the context of Bianchi-I cosmologies. In the present paper we assume an action which is part of the low energy action of string theory and study the corresponding ...

  19. Exergy in near-field electromagnetic heat transfer

    Science.gov (United States)

    Iizuka, Hideo; Fan, Shanhui

    2017-09-01

    The maximum amount of usable work extractable from a given radiative heat flow defines the exergy. It was recently noted that the exergy in near-field radiative heat transfer can exceed that in the far-field. Here, we derive a closed form formula of exergy in the near-field heat transfer between two parallel surfaces. This formula reveals that, for a given resonant frequency, the maximum exergy depends critically on the resonant linewidth, and there exists an optimal choice of the linewidth that maximizes the exergy. Guided by the analytical result, we show numerically that with a proper choice of doping concentration, the heat flow between two properly designed SiC-coated heavily doped silicon regions can possess exergy that is significantly higher compared to the heat flow between two SiC regions where the heat flow is carried out by phonon-polaritons. Our work indicates significant opportunities for either controlling material properties or enhancing the fundamental potential for near-field heat transfer in thermal energy conversion through the approach of meta-material engineering.

  20. Effects of Pulsed Electromagnetic Field on Differentiation of HUES-17 Human Embryonic Stem Cell Line

    Directory of Open Access Journals (Sweden)

    Yi-Lin Wu

    2014-08-01

    Full Text Available Electromagnetic fields are considered to potentially affect embryonic development, but the mechanism is still unknown. In this study, human embryonic stem cell (hESC line HUES-17 was applied to explore the mechanism of exposure on embryonic development to pulsed electromagnetic field (PEMF for 400 pulses at different electric field intensities and the differentiation of HUES-17 cells was observed after PEMF exposure. The expression of alkaline phosphatase (AP, stage-specific embryonic antigen-3 (SSEA-3, SSEA-4 and the mRNA level and protein level of Oct4, Sox2 and Nanog in HUES-17 cells remained unchanged after PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m. Four hundred pulses PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m did not affect the differentiation of HUES-17 cells. The reason why electromagnetic fields affect embryonic development may be due to other mechanisms rather than affecting the differentiation of embryonic stem cells.

  1. Electromagnetic field effect simulation over a realistic pixel ed phantom human's brain

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, R.; Calderon, J. A.; Rivera, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Calz. Legaria No. 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Azorin, J., E-mail: rafaelturing@prodigy.net.mx [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2012-10-15

    The exposition to different types of electromagnetic radiations can produce damages and injures on the people's tissues. The scientist, spend time and resources studying the effects of electromagnetic fields over the organs. Particularly in medical areas, the specialist in imaging methodologies and radiological treatment, are very worried about no injure there patient. Determination of matter radiation interaction, can be experimental or theoretical is not an easy task anyway. At first case, is not possible make measures inside the patient, then the experimental procedure consist in make measures in human's dummy, however, is not possible see deformations of electromagnetic fields due the organs presence. In the second case, is necessary solve, the Maxwell's equations with the electromagnetic field, crossing a lot of organs and tissues with different electric and magnetic properties each one. One alternative for theoretical solution, is make a computational simulation, however, this option, require an enormous quantity of memory and large computational times. Then, the most simulations are making in 2 dimensional or in 3 dimensional although using human models approximations, build ed with basic geometrical figures, like spheres, cylinders, ellipsoids, etc. Obviously this models just lets obtain a coarse solution of the actually situation. In this work, we propose a novel methodology to build a realistic pixel ed phantom of human's organs, and solve the Maxwell's equations over this models, evidently, the solutions are more approximated to the real behaviour. Additionally, there models results optimized when they are discretized and the finite element method is used to calculate the electromagnetic field and the induced currents. (Author)

  2. Large-scale 3-D EM modelling with a Block Low-Rank multifrontal direct solver

    Science.gov (United States)

    Shantsev, Daniil V.; Jaysaval, Piyoosh; de la Kethulle de Ryhove, Sébastien; Amestoy, Patrick R.; Buttari, Alfredo; L'Excellent, Jean-Yves; Mary, Theo

    2017-06-01

    We put forward the idea of using a Block Low-Rank (BLR) multifrontal direct solver to efficiently solve the linear systems of equations arising from a finite-difference discretization of the frequency-domain Maxwell equations for 3-D electromagnetic (EM) problems. The solver uses a low-rank representation for the off-diagonal blocks of the intermediate dense matrices arising in the multifrontal method to reduce the computational load. A numerical threshold, the so-called BLR threshold, controlling the accuracy of low-rank representations was optimized by balancing errors in the computed EM fields against savings in floating point operations (flops). Simulations were carried out over large-scale 3-D resistivity models representing typical scenarios for marine controlled-source EM surveys, and in particular the SEG SEAM model which contains an irregular salt body. The flop count, size of factor matrices and elapsed run time for matrix factorization are reduced dramatically by using BLR representations and can go down to, respectively, 10, 30 and 40 per cent of their full-rank values for our largest system with N = 20.6 million unknowns. The reductions are almost independent of the number of MPI tasks and threads at least up to 90 × 10 = 900 cores. The BLR savings increase for larger systems, which reduces the factorization flop complexity from O(N2) for the full-rank solver to O(Nm) with m = 1.4-1.6. The BLR savings are significantly larger for deep-water environments that exclude the highly resistive air layer from the computational domain. A study in a scenario where simulations are required at multiple source locations shows that the BLR solver can become competitive in comparison to iterative solvers as an engine for 3-D controlled-source electromagnetic Gauss-Newton inversion that requires forward modelling for a few thousand right-hand sides.

  3. Modern Classical Electrodynamics and Electromagnetic Radiation - Vacuum Field Theory Aspects

    OpenAIRE

    Bogolubov, N. N.; Prykarpatsky, A. K.

    2012-01-01

    The work is devoted to studying some new classical electrodynamics models of interacting charged point particles and related with them physical aspects. Based on the vacuum field theory no-geometry approach, developed in \\cite{BPT,BPT1}, the Lagrangian and Hamiltonian reformulations of some alternative classical electrodynamics models are devised. A problem closely related to the radiation reaction force is analyzed aiming to explain the Wheeler and Feynman reaction radiation mechanism, well ...

  4. Interaction of extremely-low-frequency electromagnetic fields with living systems

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1991-11-01

    The sources and physical properties of extremely-low-frequency (ELF) electromagnetic fields are described in this paper. Biological effects and mechanisms through which ELF fields interact with humans and other organisms are discussed, including several aspects of this subject that are presently under active laboratory investigation. Studies on the potential health effects of ELF fields present in the home and workplace are also summarized, including a critical evaluation of evidence for a possible linkage between exposure to ELF fields and cancer risk. 53 refs.

  5. Electromagnetic superconductivity of vacuum induced by strong magnetic field: Numerical evidence in lattice gauge theory

    Energy Technology Data Exchange (ETDEWEB)

    Braguta, V.V. [IHEP, Protvino, Moscow region, 142284 (Russian Federation); ITEP, B. Cheremushkinskaya str. 25, Moscow, 117218 (Russian Federation); Buividovich, P.V. [ITEP, B. Cheremushkinskaya str. 25, Moscow, 117218 (Russian Federation); JINR, Joliot-Curie str. 6, Dubna, Moscow region, 141980 (Russian Federation); Institute of Theoretical Physics, University of Regensburg, Universitaetsstrasse 31, D-93053 Regensburg (Germany); Chernodub, M.N., E-mail: maxim.chernodub@lmpt.univ-tours.fr [CNRS, Laboratoire de Mathematiques et Physique Theorique, Universite Francois-Rabelais Tours, Parc de Grandmont, 37200 Tours (France); Department of Physics and Astronomy, University of Gent, Krijgslaan 281, S9, B-9000 Gent (Belgium); Kotov, A.Yu.; Polikarpov, M.I. [ITEP, B. Cheremushkinskaya str. 25, Moscow, 117218 (Russian Federation); MIPT, Institutskii per. 9, Dolgoprudny, Moscow region, 141700 (Russian Federation)

    2012-12-05

    Using numerical simulations of quenched SU(2) gauge theory we demonstrate that an external magnetic field leads to spontaneous generation of quark condensates with quantum numbers of electrically charged {rho} mesons if the strength of the magnetic field exceeds the critical value eB{sub c}=0.927(77) GeV{sup 2} or B{sub c}=(1.56{+-}0.13) Dot-Operator 10{sup 16} Tesla. The condensation of the charged {rho} mesons in strong magnetic field is a key feature of the magnetic-field-induced electromagnetic superconductivity of the vacuum.

  6. [Non-thermal bioeffects of static and extremely low frequency electromagnetic fields].

    Science.gov (United States)

    Zhang, Pingping; Yin, Ruochun; Wu, Lifang; Wu, Yuejin; Yu, Zengliang

    2007-12-01

    Since epidemiologic studies have reported a modestly increased risk of oncogenesis associated with certain electromagnetic fields (EMF), popular media and scientists have raised concerns about possible health hazards of environmental exposure to EMF. Laboratory-based experiments have shown that a variety of biological responses were induced by EMF, although these results were controversial and conflicting. The non-thermal effects of low energy EMF,the possible interaction of EMF with biological system have become focus topics in the biolectromagnetic fields. This paper focuses on recent studies of static and extremely low frequency electromagnetic fields, especially the interactive mechanism between EMF and cellular membrane and protein kinase signal transduction pathways. The potential genetic toxicity and risk evaluation are also discussed. However, the existence of some positive findings and the limitations in the set of studies suggest a need for more work.

  7. General relativistic electromagnetic and massive vector field effects with gamma-ray burst production

    Science.gov (United States)

    Tamburini, Fabrizio; De Laurentis, Mariafelicia; Amati, Lorenzo; Thidé, Bo

    2017-11-01

    We propose a new energy extraction mechanism from the rotational energy of a Kerr-Newman black hole by a gravitating massive photon field generated by electromagnetic and gravitational field coupling effects. Numerical studies show that this mechanism that depends on the black hole rotation parameter, a , shows a clear dependence on the black hole mass, M , and charge, Q , and can extract energies up to 1 054 erg for a black hole of the solar mass size. With this mechanism we can set a lower bound on the coupling ξ ˜10-38 between electromagnetic and gravitational fields that might be used to explain the hypothetical extremely high energy release, >1053 erg, suggested by the observations of some gamma-ray bursts in the controversial "energy crisis" problem if and when gamma-ray bursts seem not to show evidence for collimated emission.

  8. Electromagnetic fields radiated from a lightning return stroke - Application of an exact solution to Maxwell's equations

    Science.gov (United States)

    Le Vine, D. M.; Meneghini, R.

    1978-01-01

    A solution is presented for the electromagnetic fields radiated by an arbitrarily oriented current filament over a conducting ground plane in the case where the current propagates along the filament at the speed of light, and this solution is interpreted in terms of radiation from lightning return strokes. The solution is exact in the fullest sense; no mathematical approximations are made, and the governing differential equations and boundary conditions are satisfied. The solution has the additional attribute of being specified in closed form in terms of elementary functions. This solution is discussed from the point of view of deducing lightning current wave forms from measurements of the electromagnetic fields and understanding the effects of channel tortuosity on the radiated fields. In addition, it is compared with two approximate solutions, the traditional moment approximation and the Fraunhofer approximation, and a set of criteria describing their applicability are presented and interpreted.

  9. Control of vacuum arc source cathode spots contraction motion by changing electromagnetic field

    Science.gov (United States)

    Xin, SONG; Qing, WANG; Zeng, LIN; Puhui, ZHANG; Shuhao, WANG

    2018-02-01

    This paper investigates the magnetic field component impact on cathode spots motion trajectory and the mechanism of periodic contraction. Electromagnetic coils and permanent magnets were installed at the different sides of cathode surface, the photographs of cathode spots motion trajectory were captured by a camera. Increasing the number of magnets and decreasing the distance between magnets and cathode both lead to enhancing cathode spots motion velocity. Radii of cathode spots trajectory decrease gradually with the increasing of electromagnetic coil’s current, from 40 mm at 0 A to 10 mm at 2.7 A. Parallel magnetic field component intensity influence the speed of cathode spots rotate motion, and perpendicular magnetic field component drives spots drift in the radial direction. Cathode spot’s radial drift is controlled by changing the location of the ‘zero line’ where perpendicular magnetic component shifts direction and the radius of cathode spots trajectory almost equal to ‘zero line’.

  10. Bioreactor coupled with electromagnetic field generator: effects of extremely low frequency electromagnetic fields on ethanol production by Saccharomyces cerevisiae.

    Science.gov (United States)

    Perez, Victor H; Reyes, Alfredo F; Justo, Oselys R; Alvarez, David C; Alegre, Ranulfo M

    2007-01-01

    The effect of extremely low frequency (ELF) magnetic fields on ethanol production by Saccharomyces cerevisiae using sugar cane molasses was studied during batch fermentation. The cellular suspension from the fermentor was externally recycled through a stainless steel tube inserted in two magnetic field generators, and consequently, the ethanol production was intensified. Two magnetic field generators were coupled to the bioreactor, which were operated conveniently in simple or combined ways. Therefore, the recycle velocity and intensity of the magnetic field varied in a range of 0.6-1.4 m s(-1) and 5-20 mT, respectively. However, under the best conditions with the magnetic field treatment (0.9-1.2 m s(-1) and 20 mT plus solenoid), the overall volumetric ethanol productivity was approximately 17% higher than in the control experiment. These results made it possible to verify the effectiveness of the dynamic magnetic treatment since the fermentations with magnetic treatment reached their final stage in less time, i.e., approximately 2 h earlier, when compared with the control experiment.

  11. Electromagnetic field generated by a finite fault due to electrokinetic effect

    Science.gov (United States)

    Hu, Hengshan; Gao, Yongxin

    2011-08-01

    This work investigates surface electromagnetic wavefields generated by a finite fault due to electrokinetic effect with Pride's theory as the governing equations. A finite fault is discretized into a series of small subfaults, each of which is taken as a point source with different initiation time. The wavefields generated by the whole fault are then synthesized by stacking those generated by all the subfaults. Numerical simulations of a vertical strike-slip fault with a constant rupturing velocity are then conducted on the basis of the derived formalism. Simulation results show that the rupturing fault generates observable permanent ground motions and electromagnetic field disturbances. Two types of electric field characters are observed in simulations: the coseismic oscillatory variation and the postseismic decaying variation. When the fault rupturing stops and the seismic waves pass far away, the magnetic field vanishes while the electric field remains, decaying slowly and lasting for hundreds of seconds. Adjacent to the free surface the vertical electric field is about 100 times larger than the horizontal one. When the receiving depth increases, the amplitudes of the horizontal electric fields in both the oscillatory and decaying components increase while those of the vertical electric fields decrease. It is also shown that there is no horizontal electric field remnant right at the free surface after the seismic perturbations decay away. The near-fault electric fields simulated in this paper hold similar features to some field observations in literature.

  12. THE ELECTROMAGNETIC FIELD STRUCTURE IN THE SECTORIAL RESONATOR

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available Taking into account the easy excitation, oscillation of electric type are of main practical interest, when there is on- ly one component of electric field, namely the one oriented perpendicularly to the top and bottom walls of cavity which does not experience variations along the axis. The frequency spectrum of the oscillation of the magnetron with a nominal frequency of 2.45 GHz, used in domestic microwave ovens is shown. It is evident that a certain fraction of the energy is released in the side of the frequency spectrum and can be a source of excitation of the corresponding vibration of higher orders. For a quantitative descriptions of the heat distribution in the warming volume statistical criteria are used, in particu- lar, the standard deviation of the power dissipation value, normalized to the average value. The solution of the problem of the field in the radial sectorial resonator with perfectly conducting walls is obtained. Some of its applications are consid- ered. The analysis of the possibility of using sectorial resonators in microwave devices division / capacity addition is car- ried out. A possible variant of wave superimposition device for microwave heating, using the union of four sectorial cavi- ties with an angle of 900 is proposed.

  13. Childhood brain tumors and residential electromagnetic fields (EMF).

    Science.gov (United States)

    Kheifets, L I; Sussman, S S; Preston-Martin, S

    1999-01-01

    There are many recent comprehensive reviews of the residential EMF epidemiologic literature, but they do not attempt to cover the issue of childhood brain tumors and EMF in depth. We present here background information on descriptive epidemiology of known or suspected causes of childhood brain tumors and a detailed review of studies that have examined the associations between EMF as represented by various surrogates, and childhood brain tumors. We evaluated nine studies of childhood brain tumors and residential exposure to EMF based on wire codes, distance, measurements, and modeling, and six studies that examined the use of appliances by children or their mothers during pregnancy. For each study we discussed analytical and methodological issues including choice of cutpoints, nonconcurrent control selection, random digit dialing, differential participation, and ability of a study to detect an association. On the basis of this comprehensive review of all available childhood brain cancer studies, we do not see support for an overall association between EMF and childhood brain cancer. This lack of support applied for all surrogates of past magnetic fields, including wire code, distance, measured or calculated fields, and use of appliances by either child or mother.

  14. Effect of microwave electromagnetic field on skeletal muscle fibre activity.

    Science.gov (United States)

    Radicheva, N; Mileva, K; Vukova, T; Georgieva, B; Kristev, I

    2002-07-01

    The aim of the present study was to investigate the influence of microwave irradiation on fatiguing activity of isolated frog skeletal muscle fibres. The changes in the electrical and mechanical activity were used as criteria for the exposure effects. Repetitive suprathreshold stimulation with interstimulus interval of 200 ms for 3 min was applied. Intracellular (ICAP) and extracellular (ECAP) action potentials and twitch contractions (Tw) of muscle fibres after 1 hour microwave exposure (2.45 GHz, 20 mW/cm( 2) power density) were compared with those recorded after one hour sham exposure (control). The duration of uninterrupted activity in the trial (endurance time; ET) was not significantly affected by microwave field exposure. After microwave irradiation, the ICAP amplitude was higher, the rising time was shorter, and the resting membrane potential was more negative compared to controls. There was a slower rate of parameters changes during ET in potentials obtained from irradiated fibres. Microwave exposure increased the propagation velocity of excitation, the ECAP and Tw amplitudes, as well as shortened their time parameters. We concluded that a 2.45 GHz microwave field possesses a stimulating effect on muscle fibre activity, which is in part due to its specific, non-thermal properties. The microwave induced-changes in muscle fibre activity may reduce development of skeletal muscle fatigue.

  15. Localization of the electromagnetic field in the vicinity of gold nanoparticles: Surface modification of different substrates

    Energy Technology Data Exchange (ETDEWEB)

    Atanasov, Petar A. [Institute of Electronics, Bulgarian Academy of Sciences, Tzarigradsko Shousse 72, Sofia 1784 (Bulgaria)], E-mail: paatanas@ie.bas.bg; Nedyalkov, Nikolay N. [Department of Electronics and Electrical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Institute of Electronics, Bulgarian Academy of Sciences, Tzarigradsko Shousse 72, Sofia 1784 (Bulgaria); Sakai, Tetsuo; Obara, Minoru [Department of Electronics and Electrical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

    2007-12-15

    Theoretical predictions and experimental results for nanosized modification of metal (Au), semiconductor (Si), or dielectric (soda lime glass) substrates using near-electromagnetic field enhancement in the vicinity of gold nanoparticles are presented. The near field properties for the system consisting of an isolated gold nanoparticle or nanoparticle aggregate deposited on the substrates, which is irradiated by electromagnetic wave, are investigated using Finite Difference Time Domain Simulation technique. The influence of the substrate material on the near field distribution characteristics is predicted. The results reveal that the field on the substrate surface is enhanced in the three investigated cases, but its spatial distribution and magnitude depend on the substrate material. In the case of the metal and semiconductor substrate the enhanced near field is strongly localized in the vicinity of the contact point with the particle, in an area with diameter smaller than the particle's one. The intensity of the enhanced field on the glass is more than an order of magnitude lower than the case of using silicon substrate. The properties of the near field on the substrate surface also depend on the particle arrangement. For a two-dimensional gold nanoparticle array, when the particles are closely arrayed, the intensity of the enhanced field on the substrate surface is minimal. With the increase of the interparticle distance the near field intensity increases. The validity of the obtained theoretical results is confirmed experimentally.

  16. Accuracy of electromagnetic tracking with a prototype field generator in an interventional OR setting

    Energy Technology Data Exchange (ETDEWEB)

    Boe, Lars Eirik; Leira, Haakon Olav; Tangen, Geir Arne; Hofstad, Erlend Fagertun; Amundsen, Tore; Langoe, Thomas [Department of Medical Technology, SINTEF Technology and Society, Trondheim (Norway) and Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway) and Department of Thoracic Medicine, St. Olavs Hospital, Trondheim (Norway); Department of Medical Technology, SINTEF Technology and Society, Trondheim (Norway); Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway) and Department of Thoracic Medicine, St. Olavs Hospital, Trondheim (Norway); Department of Medical Technology, SINTEF Technology and Society, Trondheim (Norway)

    2012-01-15

    Purpose: The authors have studied the accuracy and robustness of a prototype electromagnetic window field generator (WFG) in an interventional radiology suite with a robotic C-arm. The overall purpose is the development of guidance systems combining real-time imaging with tracking of flexible instruments for bronchoscopy, laparoscopic ultrasound, endoluminal surgery, endovascular therapy, and spinal surgery. Methods: The WFG has a torus shape, which facilitates x-ray imaging through its centre. The authors compared the performance of the WFG to that of a standard field generator (SFG) under the influence of the C-arm. Both accuracy and robustness measurements were performed with the C-arm in different positions and poses. Results: The system was deemed robust for both field generators, but the accuracy was notably influenced as the C-arm was moved into the electromagnetic field. The SFG provided a smaller root-mean-square position error but was more influenced by the C-arm than the WFG. The WFG also produced smaller maximum and variance of the error. Conclusions: Electromagnetic (EM) tracking with the new WFG during C-arm based fluoroscopy guidance seems to be a step forward, and with a correction scheme implemented it should be feasible.

  17. Origin of the Earth's Electromagnetic Field Based on the Pulsating Mantle Hypothesis (PMH)

    Science.gov (United States)

    Gholibeigian, Hassan

    2017-11-01

    In PMH, the Earth's Inner Core's Dislocation (ICD) and Outer Core's Bulge (OCB) phenomena are generated by unbalanced gravitational fields of the Sun and Moon on the Earth. Distance between the Earth's center and inner core's center varies permanently in magnitude and direction inside two hemispheres. Geometrical loci of the inner core's center has the shape of back and force spiral cone in each hemisphere. In other words, the inner core is rotating fast in the outer core inverse of the Earth's rotation a round per day. This mechanism speed up the processes inside the core and generates a Large Scale Forced Convection System (LSFCS) inverse of the Earth's rotation in the core. The LSFCS is the origin of the Earth's electromagnetic field. The LSFCS generates huge mass transfer and momentum of inertia inside the Earth too. The inner core's axis which is the Earth's electromagnetic axis doesn't cross the Earth's geophysical axis and rotates around it per day. The mechanism of this LSFCS has diurnal, monthly and yearly cycles. These cycles are sources of the Earth's electromagnetic field variability. Direction of the variable Earth's magnetic field lines from the South Pole (hemisphere) to the sky and 146 seconds/years apparent solar day length variations can be two observable factors for this mechanism. This dynamic system may occurred inside the other planets like the Sun and the Jupiter.

  18. Design of a mobile, homogeneous, and efficient electromagnet with a large field of view for neonatal low-field MRI.

    Science.gov (United States)

    Lother, Steffen; Schiff, Steven J; Neuberger, Thomas; Jakob, Peter M; Fidler, Florian

    2016-08-01

    In this work, a prototype of an effective electromagnet with a field-of-view (FoV) of 140 mm for neonatal head imaging is presented. The efficient implementation succeeded by exploiting the use of steel plates as a housing system. We achieved a compromise between large sample volumes, high homogeneity, high B0 field, low power consumption, light weight, simple fabrication, and conserved mobility without the necessity of a dedicated water cooling system. The entire magnetic resonance imaging (MRI) system (electromagnet, gradient system, transmit/receive coil, control system) is introduced and its unique features discussed. Furthermore, simulations using a numerical optimization algorithm for magnet and gradient system are presented. Functionality and quality of this low-field scanner operating at 23 mT (generated with 500 W) is illustrated using spin-echo imaging (in-plane resolution 1.6 mm × 1.6 mm, slice thickness 5 mm, and signal-to-noise ratio (SNR) of 23 with a acquisition time of 29 min). B0 field-mapping measurements are presented to characterize the homogeneity of the magnet, and the B0 field limitations of 80 mT of the system are fully discussed. The cryogen-free system presented here demonstrates that this electromagnet with a ferromagnetic housing can be optimized for MRI with an enhanced and homogeneous magnetic field. It offers an alternative to prepolarized MRI designs in both readout field strength and power use. There are multiple indications for the clinical medical application of such low-field devices.

  19. Optical electromagnetic vector-field modeling for the accurate analysis of finite diffractive structures of high complexity

    DEFF Research Database (Denmark)

    Dridi, Kim; Bjarklev, Anders Overgaard

    1999-01-01

    An electromagnetic vector-field modle for design of optical components based on the finite-difference-time-domain method and radiation integrals in presented. Its ability to predict the optical electromagnetic dynamics in structures with complex material distribution is demonstrated. Theoretical...

  20. Electromagnetic Field Theory in (N+1)-Space-Time : AModern Time-Domain Tensor/Array Introduction

    NARCIS (Netherlands)

    De Hoop, A.T.

    2012-01-01

    In this paper, a modern time-domain introduction is presented for electromagnetic field theory in (N+1)-spacetime. It uses a consistent tensor/array notation that accommodates the description of electromagnetic phenomena in N-dimensional space (plus time), a requirement that turns up in present-day

  1. Electromagnetic waves reflection, transmission and absorption by graphene - magnetic semiconductor - graphene sandwich-structure in magnetic field: Faraday geometry

    OpenAIRE

    Kuzmin, Dmitry A.; Bychkov, Igor V.; Shavrov, Vladimir G.

    2014-01-01

    Electrodynamic properties of the graphene - magnetic semiconductor - graphene sandwich-structure have been investigated theoretically with taking into account the dissipation processes. Influence of graphene layers on electromagnetic waves propagation in graphene - semi-infinte magnetic semiconductor and graphene - magnetic semiconductor - graphene sandwich-structure has been analyzed. Frequency and field dependences of the reflectance, transmittance and absorbtance of electromagnetic waves b...

  2. Electromagnetic superconductivity of vacuum induced by strong magnetic field: numerical evidence in lattice gauge theory

    CERN Document Server

    Braguta, V V; Chernodub, M N; Polikarpov, M I

    2011-01-01

    Using numerical simulations of SU(2) lattice gauge theory we demonstrate from first principles that an external magnetic field leads to spontaneous generation of quark condensates with quantum numbers of electrically charged rho mesons if the strength of the magnetic field exceeds the critical value eB_c = 0.927(77) GeV^2 or B_c =(1.56 \\pm 0.13) 10^{16} Tesla. The condensation of the charged $\\rho$ mesons in strong magnetic field is a key feature of the recently proposed electromagnetic superconductivity of the vacuum.

  3. Numerical computation of electromagnetic field for general static and axisymmetric current distribution

    Science.gov (United States)

    Fukushima, Toshio

    2017-12-01

    We developed a numerical method to compute the electromagnetic field of arbitrary static and axisymmetric current distribution. The method (i) numerically evaluates a double integral of the electrostatic and magnetostatic potentials of an infinitely thin ring current by the split quadrature method using the double exponential rules, and (ii) derives the electrostatic field and the magnetostatic induction by numerically differentiating the numerically integrated potentials by the central difference formula. A comparison with the exact solution for a poloidal current distribution with an anisotropic Gaussian damping confirmed the 14- and 9-digit accuracy of the potential and the field/induction computed by the new method.

  4. Local geometry of electromagnetic fields and its role in molecular multipole transitions.

    Science.gov (United States)

    Yang, Nan; Cohen, Adam E

    2011-05-12

    Electromagnetic fields with complex spatial variation routinely arise in Nature. We study the response of a small molecule to monochromatic fields of arbitrary three-dimensional geometry. First, we consider the allowed configurations of the fields and field gradients at a single point in space. Many configurations cannot be generated from a single plane wave, regardless of polarization, but any allowed configuration can be generated by superposition of multiple plane waves. There is no local configuration of the fields and gradients that requires near-field effects. Second, we derive a set of local electromagnetic quantities, each of which couples to a particular multipole transition. These quantities are small or zero in plane waves, but can be large in regions of certain superpositions of plane waves. Our findings provide a systematic framework for designing far-field and near-field experiments to drive multipole transitions. The proposed experiments provide information on molecular structure that is inaccessible to other spectroscopic techniques and open the possibility for new types of optical control of molecules.

  5. Implementation of visual programming methods for numerical techniques used in electromagnetic field theory

    Directory of Open Access Journals (Sweden)

    Metin Varan

    2017-08-01

    Full Text Available Field theory is one of the two sub-field theories in electrical and electronics engineering that for creates difficulties for undergraduate students. In undergraduate period, field theory has been taught under the theory of electromagnetic fields by which describes using partial differential equations and integral methods. Analytical methods for solution of field problems on the basis of a mathematical model may result the understanding difficulties for undergraduate students due to their mathematical and physical infrastructure. The analytical methods which can be applied in simple model lose their applicability to more complex models. In this case, the numerical methods are used to solve more complex equations. In this study, by preparing some field theory‘s web-based graphical user interface numerical methods of applications it has been aimed to increase learning levels of field theory problems for undergraduate and graduate students while taking in mind their computer programming capabilities.

  6. A Robust Multi-Scale Field-Only Formulation of Electromagnetic Scattering

    CERN Document Server

    Sun, Qiang; Chan, Derek Y C

    2016-01-01

    We present a boundary integral formulation of electromagnetic scattering by homogeneous bodies that are characterized by linear constitutive equations in the frequency domain. By working with the Cartesian components of the electric, E and magnetic, H fields and with the scalar functions (r*E) and (r*H), the problem is cast as solving a set of scalar Helmholtz equations for the field components that are coupled by the usual electromagnetic boundary conditions at material boundaries. This facilitates a direct solution for E and H rather than working with surface currents as intermediate quantities in existing methods. Consequently, our formulation is free of the well-known numerical instability that occurs in the zero frequency or long wavelength limit in traditional surface integral solutions of Maxwell's equations and our numerical results converge uniformly to the static results in the long wavelength limit. Furthermore, we use a formulation of the scalar Helmholtz equation that is expressed as classically ...

  7. Faraday, Maxwell, and the electromagnetic field how two men revolutionized physics

    CERN Document Server

    Forbes, Nancy

    2014-01-01

    The story of two brilliant nineteenth-century scientists who discovered the electromagnetic field, laying the groundwork for the amazing technological and theoretical breakthroughs of the twentieth century Two of the boldest and most creative scientists of all time were Michael Faraday (1791-1867) and James Clerk Maxwell (1831-1879). This is the story of how these two men - separated in age by forty years - discovered the existence of the electromagnetic field and devised a radically new theory which overturned the strictly mechanical view of the world that had prevailed since Newton's time. The authors, veteran science writers with special expertise in physics and engineering, have created a lively narrative that interweaves rich biographical detail from each man's life with clear explanations of their scientific accomplishments. Faraday was an autodidact, who overcame class prejudice and a lack of mathematical training to become renowned for his acute powers of experimental observation, technological skil...

  8. Generation of large scale field-aligned density irregularities in ionospheric heating experiments. [electromagnetic wave decay

    Science.gov (United States)

    Fejer, J. A.

    1974-01-01

    Threshold and growth rate for stimulated Brillouin scattering are calculated for a uniform magnetoplasma. These are then compared with the threshold and growth rate of a new thermal instability in which the nonlinear Lorentz force felt by the electrons at the beat frequency of the two electromagnetic waves is replaced by a pressure force due to differential heating in the interference pattern of the pump wave and the generated electromagnetic wave. This thermal instability, which is still essentially stimulated Brillouin scattering, has a threshold which is especially low when the propagation vector of the beat wave is almost normal to the magnetic field. The threshold is then considerably lower than the threshold for normal stimulated Brillouin scattering and therefore this new instability is probably responsible for the generation of large scale field aligned irregularities and ionospheric spread F.

  9. Electromagnetically induced transparency and absorption in plasmonic metasurfaces based on near-field coupling

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Ming-li, E-mail: mlwan@pdsu.edu.cn [College of Electric and Information Engineering, Pingdingshan University, Pingdingshan 467000 (China); He, Jin-na [College of Electric and Information Engineering, Pingdingshan University, Pingdingshan 467000 (China); Song, Yue-li [College of Electric and Information Engineering, Pingdingshan University, Pingdingshan 467000 (China); New PV-energy Engineering Research Center, Pingdingshan University, Pingdingshan 467000 (China); Zhou, Feng-qun [College of Electric and Information Engineering, Pingdingshan University, Pingdingshan 467000 (China)

    2015-09-04

    We theoretically investigate optical properties of a plasmonic metasurface consisting of a dipolar wire as the bright antenna stacked above a quadrupolar wire as the dark antenna. It is demonstrated that by adjusting the lateral displacement between the two resonators, the spectral feature of the metasurface can be evolved from the plasmonic electromagnetically-induced transparency to electromagnetically-induced absorption. The extracted physical parameters based on the two-coupled-oscillator model reveal that the near-field coupling strength plays a key role for the transition behavior in the plasmonic metasurface. - Highlights: • We study spectral response of metamaterial in dependence on near-field coupling. • Coupled two-oscillator is adopted to explain the spectral behavior. • For weak coupling, metamaterials exhibit an EIA-like feature. • For strong coupling, metamaterials exhibit an EIT-like profile.

  10. Electromagnetic field of a bunch intersecting a dielectric plate in a waveguide

    Science.gov (United States)

    Alekhina, Tatiana Yu; Tyukhtin, Andrey V.

    2014-05-01

    The electromagnetic field (EMF) of a bunch moving uniformly and traversing a dielectric plate located in a waveguide is investigated. The main attention is focused on the case when Cherenkov radiation is generated in the plate. Analysis of the field components of the mode is performed with methods of the complex variable function theory. An algorithm of computation using the exact expressions for the EMF is also presented. Consideration of the EMF structure for different time moments is given. It is shown that Cherenkov-transition radiation (CTR) is generated in the vacuum area after the plate under certain conditions. Results obtained might be of interest for development of new methods of generation of electromagnetic radiation.

  11. Anthropogenic radiofrequency electromagnetic fields as an emerging threat to wildlife orientation.

    Science.gov (United States)

    Balmori, Alfonso

    2015-06-15

    The rate of scientific activity regarding the effects of anthropogenic electromagnetic radiation in the radiofrequency (RF) range on animals and plants has been small despite the fact that this topic is relevant to the fields of experimental biology, ecology and conservation due to its remarkable expansion over the past 20 years. Current evidence indicates that exposure at levels that are found in the environment (in urban areas and near base stations) may particularly alter the receptor organs to orient in the magnetic field of the earth. These results could have important implications for migratory birds and insects, especially in urban areas, but could also apply to birds and insects in natural and protected areas where there are powerful base station emitters of radiofrequencies. Therefore, more research on the effects of electromagnetic radiation in nature is needed to investigate this emerging threat. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Mork, B; Nelson, R; Kirkendall, B; Stenvig, N

    2009-11-30

    Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

  13. Electromagnetic-field effects on structure and dynamics of amyloidogenic peptides

    Science.gov (United States)

    Todorova, Nevena; Bentvelzen, Alan; English, Niall J.; Yarovsky, Irene

    2016-02-01

    Electromagnetic fields (EMFs) are ever-present, and so is the need to better understand their influence on human health and biological matter in general. The interaction between a molecular system and external EMF can alter the structure, and dynamical behaviour, and, hence, biological function of proteins with uncertain health consequences. This urges a detailed investigation of EMF-induced effects on basic protein biophysics. Here, we used all-atom non-equilibrium molecular dynamics simulations to understand and quantify the response mechanisms of the amyloidogenic apoC-II(60-70) peptides to non-ionising radiation by modelling their behaviour under external electromagnetic and electric fields of different strengths. Our simulations show high strength fields (>0.04 V/nm) cause structural changes in apoC-II(60-70) due to the peptide dipole alignment along the applied field direction, which disrupts the inherent β-hairpin conformation known to be the intermediate state for fibril formation. The intermediate field-strength range (0.04-0.004 V/nm) causes a significant acceleration in peptide dynamics, which leads to the increased population of structures with fibril-inhibiting characteristics, such as the separated N- and C-termini and colocation of the aromatic residues at the same peptide face. In contrast, lower field strengths (<0.004 V/nm) promote the formation of the amyloid-prone hairpin structures relative to the ambient conditions. These findings suggest that intermediate-strength electromagnetic fields could be considered for designing alternative treatments of amyloid diseases, while the very high and low field strengths could be employed for engineering well-ordered fibrillar aggregates for non-medicinal applications.

  14. A Physiological and Biochemical Study of the Effects of Extremely Low Frequency Electromagnetic Fields

    Science.gov (United States)

    1979-07-01

    to rule out certain non-EHF factors as be-I iqng responsible for the biological chanqes. Factors tested include ambient electromagnetic fields...to rule out a number of non-Etf factors as possible causes of the observed physioloqical chanqes in These factors are incubator differences, ambient ...organism apparently *remembers" its ltrevious exposure. If one proceeds from our earlier finding that, while subtle " genetica chng*es may have occurred

  15. BLANKET REPRESENTATION AND EXPEDIENT OF DISINFECTING WATER USING PULSING ELECTROMAGNETIC FIELD

    Directory of Open Access Journals (Sweden)

    Ibragimova Ozoda

    2013-11-01

    Full Text Available ABSTRACT:  The paper deals with comparative analysis of existing expedients and devices of disinfecting water, spots ways of the solution and a new method of  water purification using electromagnetic field applied in a cross wise direction. ABSTRAK: Dalam operasi, analisis perbandingan dijalankan bagi menentukan  kesesuaian yang sedia ada dan alatan untuk menyahjangkit air. Dengan mengaplikasikan medan magnet lintang, penyelesaian masalah dikenal pasti dengan meningkatkan kemagnetan terhadap medan elektromagnet ke atas air.

  16. Explicit high-order symplectic integrators for charged particles in general electromagnetic fields

    OpenAIRE

    Tao, Molei

    2016-01-01

    This article considers non-relativistic charged particle dynamics in both static and non-static electromagnetic fields, which are governed by nonseparable, possibly time-dependent Hamiltonians. For the first time, explicit symplectic integrators of arbitrary high-orders are constructed for accurate and efficient simulations of such mechanical systems. Performances superior to the standard non-symplectic method of Runge-Kutta are demonstrated on two examples: the first is on the confined motio...

  17. Osteogenic differentiation of amniotic epithelial cells: synergism of pulsed electromagnetic field and biochemical stimuli

    OpenAIRE

    Wang, Qian; Wu, Wenchao; Han, Xiaoyu; Zheng, Ai; Lei, Song; Wu, Jiang; Chen, Huaiqing; He, Chengqi; Luo, Fengming; Liu, Xiaojing

    2014-01-01

    Background Pulsed electromagnetic field (PEMF) is a non-invasive physical therapy used in the treatment of fracture nonunion or delayed healing. PEMF can facilitate the osteogenic differentiation of bone marrow mesenchymal stem cells in vitro. Amniotic epithelial cells (AECs) have been proposed as a potential source of stem cells for cell therapy. However, whether PEMF could modulate the osteogenic differentiation of AECs is unknown. In the present study, the effects of PEMF on the osteogenic...

  18. Quasi-one-dimensional ballistic ring in the field of circularly polarized electromagnetic wave

    OpenAIRE

    Epshtein, E. M.; Fedorov, E. G.; Shmelev, G. M.

    2004-01-01

    Dynamics is studied of an electron in a quasi-one-dimensional ballistic ring under circularly polarized electromagnetic field propagating along the normal to the ring plane. The average emission intensity from the ring is calculated. The value and direction of the electron average angular velocity in the ring depend on the incident wave parameters. It is found that the ring average dipole moment can remain constant under certain conditions. Possibility is shown of higher harmonics enhancement...

  19. Pulsed Electromagnetic Field Stimulates Cellular Proliferation in Human Intervertebral Disc Cells

    OpenAIRE

    Lee, Hwan-Mo; Kwon, Un-Hye; Kim, Hyang; Kim, Ho-Joong; Kim, Boram; Park, Jin-Oh; Moon, Eun-Soo; Moon, Seong-Hwan

    2010-01-01

    Purpose The purpose of this study is to investigate the mechanism of cellular proliferation of electromagnetic field (EMF) on human intervertebral disc (IVD) cells. Materials and Methods Human IVD cells were cultured three-dimensionally in alginate beads. EMF was exposed to IVD cells with 650?, 1.8 millitesla magnetic flux density, 60 Hz sinusoidal wave. Cultures were divided into a control and EMF group. Cytotoxicity, DNA synthesis and proteoglycan synthesis were measured by MTT assay, [3H]-...

  20. The Energy Metabolism in Caenorhabditis elegans under The Extremely Low-Frequency Electromagnetic Field Exposure

    OpenAIRE

    Shi, Zhenhua; Yu, Hui; Sun, Yongyan; Yang, Chuanjun; Lian, Huiyong; Cai, Peng

    2015-01-01

    A literal mountain of documentation generated in the past five decades showing unmistakable health hazards associated with extremely low-frequency electromagnetic fields (ELF-EMFs) exposure. However, the relation between energy mechanism and ELF-EMF exposure is poorly understood. In this study, Caenorhabditis elegans was exposed to 50?Hz ELF-EMF at intensities of 0.5, 1, 2, and 3?mT, respectively. Their metabolite variations were analyzed by GC-TOF/MS-based metabolomics. Although minimal meta...

  1. Exposure to radiofrequency electromagnetic fields and sleep quality : a prospective cohort study

    OpenAIRE

    Evelyn Mohler; Patrizia Frei; Jürg Fröhlich; Charlotte Braun-Fahrländer; Martin Röösli

    2012-01-01

    BACKGROUND: There is persistent public concern about sleep disturbances due to radiofrequency electromagnetic field (RF-EMF) exposure. The aim of this prospective cohort study was to investigate whether sleep quality is affected by mobile phone use or by other RF-EMF sources in the everyday environment. METHODS: We conducted a prospective cohort study with 955 study participants aged between 30 and 60 years. Sleep quality and daytime sleepiness was assessed by means of standardized questionna...

  2. Orthodontics in a quantum world III: electromagnetic field theory and oral parafunction.

    Science.gov (United States)

    James, Gavin

    2008-01-01

    The study of electromagnetic field theory and bioenergy has established that there is an extensive communication system throughout the body by way of a functional matrix. This enables the body to use the mouth to assist it during the expenditure of effort elsewhere in the body. A variety of oral behaviors can be identified as contributing to this. To some extent, these behaviors indicate where an imbalance is present in the body.

  3. Does Exposure to a Radiofrequency Electromagnetic Field Modify Thermal Preference in Juvenile Rats?

    OpenAIRE

    Amandine Pelletier; Stéphane Delanaud; René de Seze; Véronique Bach; Jean-Pierre Libert; Nathalie Loos

    2014-01-01

    Some studies have shown that people living near a mobile phone base station may report sleep disturbances and discomfort. Using a rat model, we have previously shown that chronic exposure to a low-intensity radiofrequency electromagnetic field (RF-EMF) was associated with paradoxical sleep (PS) fragmentation and greater vasomotor tone in the tail. Here, we sought to establish whether sleep disturbances might result from the disturbance of thermoregulatory processes by a RF-EMF. We recorded th...

  4. Extremely low frequency electromagnetic fields (EMF) and brain cancer in adults and children: review and comment.

    OpenAIRE

    Gurney, J G; van Wijngaarden, E

    1999-01-01

    Epidemiologic and experimental research on the potential carcinogenic effects of extremely low frequency electromagnetic fields (EMF) has now been conducted for over two decades. Cancer epidemiology studies in relation to EMF have focused primarily on brain cancer and leukemia, both from residential sources of exposure in children and adults and from occupational exposure in adult men. Because genotoxic effects of EMF have not been shown, most recent laboratory research has attempted to show ...

  5. Stable algorithm for the computation of the electromagnetic field distribution of eigenmodes of periodic diffraction structures.

    Science.gov (United States)

    Bezus, Evgeni A; Doskolovich, Leonid L

    2012-11-01

    In the present work, a stable algorithm for the calculation of the electromagnetic field distributions of the eigenmodes of one-dimensional diffraction gratings is presented. The proposed approach is based on the method for the computation of the propagation constants of Bloch waves of such structures previously presented by Cao et al.[J. Opt. Soc. Am. A 19, 335 (2002)] and uses a modified S-matrix algorithm to ensure numerical stability.

  6. INFLUENCE OF ANTHROPOGENIC ELECTROMAGNETIC FIELDS ON THE ADAPTIVE MYCOBACTERIUM’S POLYMORPHISM

    Directory of Open Access Journals (Sweden)

    Vlasenko V.V., Vlasenko I.G., Volyanskiy A. Yu.

    2011-12-01

    Full Text Available In this article the features of development of exciter of tuberculosis are lighted at the action of the electromagnetic field of antropogenic origin subject to the condition in vitro. It is shown that the microstructure of pathogenic of tuberculosis after treatment an ionizing and unionizing irradiation is not violated, and reproductive activity grows, that is confirmed the results of cultural researches and electronic and computer microscopy.

  7. Personal exposure to radio frequency electromagnetic fields and implications for health

    OpenAIRE

    Frei, Patrizia

    2010-01-01

    Exposure to radio frequency electromagnetic fields (RF-EMFs), as produced by mobile phone base stations, broadcast transmitters and cordless phones, has considerably increased over the past 20 years, especially due to the rapid expansion of the mobile phone communication network. Little is known about typical RF-EMF exposure levels and the spatial and temporal variability of RF-EMFs in our environment. Moreover, the contribution of the various exposure sources to total exposure has not been q...

  8. Effects of Multipolar Radiofrequency and Pulsed Electromagnetic Field Treatment for Face and Neck Rejuvenation

    Directory of Open Access Journals (Sweden)

    Thais Cristina Ferraz de Oliveira

    2017-01-01

    Full Text Available Skin aging is a gradual process that leads to wrinkle formation, laxity, and overall changes in skin appearance. In recent years, the demands to noninvasive treatments for facial rejuvenation increased, along with a variety of technologies and devices, such as radiofrequency. The present study aimed to evaluate the clinical effects of a multipolar radiofrequency and pulsed electromagnetic field treatment for face and neck rejuvenation. Eleven patients with mild to moderate grades of photoaging underwent eight radiofrequency and pulsed electromagnetic field treatment sessions, once a week. Clinical photographs were taken before and a week after the end of the treatment, and improvement of facial skin parameters was evaluated by two different investigators. Significant improvement in skin laxity was observed in all eleven patients (100%. Improvement in facial contour was noted in 73% and 100% of patients when analyzed by investigators A and B, respectively. The score for overall improvement in skin condition was 3 ± 0.78 for investigator A and 3.6 ± 0.67 for investigator B. All patients were satisfied with the procedure and noted significant improvement in the skin. The combined multipolar radiofrequency and pulsed electromagnetic field device is effective and safe for treatment of aged skin in Brazilian patients.

  9. Joint actions of environmental nonionizing electromagnetic fields and chemical pollution in cancer promotion.

    Science.gov (United States)

    Adey, W R

    1990-06-01

    Studies of environmental electromagnetic (EM) field interactions in tissues have contributed to a new understanding of both normal growth and the biology of cancer in cell growth. From cancer research comes a floodtide of new knowledge about the disruption of communication by cancer-promoting chemicals with an onset of unregulated growth. Bioelectromagnetic research reveals clear evidence of joint actions at cell membranes of chemical cancer promoters and environmental electromagnetic fields. The union of these two disciplines has resulted in the first major new approach to tumor formation in 75 years, directing attention to dysfunctions in inward and outward streams of signals at cell membranes, rather than to damage DNA in cell nuclei, and to synergic actions of chemical pollutants and environmental electromagnetic fields. We are witnesses and, in great measure, participants in one of the great revolutions in the history of biology. In little more than a century, we have moved from organs, to tissues, to cells, and finally to the molecules that are the elegant fabric of living tissues. Today, we stand at a new frontier. It may be more difficult to comprehend, but it is far more significant; for it is at the atomic level, rather than the molecular, that physical, rather than chemical, processes appear to shape the flow of signals that are at the essence of living matter. To pursue these problems in the environment and in the laboratory, our needs for further research with appropriate budgets are great.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Influence of Pulsed Electromagnetic Field on Plant Growth, Nutrient Absorption and Yield of Durum Wheat

    Directory of Open Access Journals (Sweden)

    Nikolaos KATSENIOS

    2015-12-01

    Full Text Available Researchers have adopted the use of magnetic field as a new pre-sowing, environmental friendly technique. Enhancements on plant characteristics with economic impact on producer’s income could be the future of a modern, organic and sustainable agriculture. A field experiment was established at Soil Science Institute of Athens, Lycovrissi, Greece, in the winter of 2014. Two durum wheat cultivars were used. It was a pot experiment with 6 treatments (2 cultivars with 3 magnetic field time exposure. The seeds were treated using a PAPIMI electromagnetic field generator for 0, 30 and 45 minutes one day before planting. The experiment followed a completely randomized design with six treatments and 30 replications. The aim of this study was to evaluate the positive effect of magnetic field pre-sowing treatment in a wide range of plant measurements, including yield. The influence of pulsed electromagnetic field on two varieties of durum wheat seeds showed some statistically significant differences at the 0.05 level in growth measurements, physiological measurements and root growth measurements. Plant tissue analysis showed that magnetic field treatments had higher values than control in total nitrogen, phosphorus, potassium, magnesium, copper (only MF-45, zinc (only MF-30 and boron content, although values showed statistically significant differences only in total nitrogen. The results indicate that this innovative technique can increase the yield of durum wheat, through enhanced absorption of nutrients. Pre-sowing treatment of the seeds leads to vigorous plant growth that are more productive.

  11. Precise measurement of a magnetic field generated by the electromagnetic flux compression technique

    Science.gov (United States)

    Nakamura, D.; Sawabe, H.; Matsuda, Y. H.; Takeyama, S.

    2013-04-01

    The precision of the values of a magnetic field generated by electromagnetic flux compression was investigated in ultra-high magnetic fields of up to 700 T. In an attempt to calibrate the magnetic field measured by pickup coils, precise Faraday rotation (FR) measurements were conducted on optical (quartz and crown) glasses. A discernible "turn-around" phenomenon was observed in the FR signal as well as the pickup coils before the end of a liner implosion. We found that the magnetic field measured by pickup coils should be corrected by taking into account the high-frequency response of the signal transmission line. Near the peak magnetic field, however, the pickup coils failed to provide reliable values, leaving the FR measurement as the only method to precisely measure extremely high magnetic fields.

  12. Far-zone coherence changes of electromagnetic scattered field generated by an anisotropic particulate medium.

    Science.gov (United States)

    Peng, Xinyu; Ye, Dong; Zhou, Munchun; Xin, Yu; Song, Minmin

    2017-08-01

    The far-zone scattered field generated by an anisotropic particulate medium with electromagnetic plane incident waves is discussed. The analytical expressions of the spectral density and spectral degree of coherence of the scattered field are derived, which show that the coherence properties of the scattered field depend on the characteristics of each particle and the distribution of particles. By simulations of two special cases, i.e., anisotropic random particles with isotropic determinate distribution and isotropic determinate particles with anisotropic random distribution, the properties of the medium and the polarization states of the incident wave play roles in the distribution of the spectral degree of coherence of the scattered field. Moreover, the general condition, anisotropic particles with anisotropic distribution, is briefly discussed. By comparing the results generated by different parameters, the coherence changes of scattered field are found in the scattered field.

  13. Numerical Calculation of Electric Fields in Housing Spaces due to Electromagnetic Radiation from Antennas for Mobile Communication

    Directory of Open Access Journals (Sweden)

    H.-P. Geromiller

    2004-01-01

    Full Text Available The influence of electromagnetic radiation from mobile antennas on humans is under discussion in various group of scientists. This paper deals with the impact of electromagnetic radiation in housing spaces. The space is assumed to be bordered by 5 walls of ferroconcrete and a door-window combination on the 6th side, the latter to be electromagnetic transparent. The transparent side of the housing is exposed to an electromagnetic wave. As the source of radiation is considered to be far away from the housing, the radiation is regarded as a plane wave. Due to the high signal frequency and the ferroconcrete walls, 5 sides of the housing space are considered to be perfect conductors. The electric field inside the housing is calculated numerically by the method of finite differences for different angles of incidence of the radiated electromagnetic wave. The maximum value of the calculated electric field is outlined in a diagram.

  14. Association between electromagnetic field exposure and abortion in pregnant women living in Tehran

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Javad Mortazavi

    2017-08-01

    Full Text Available With great interest, we have read the article by Abad et al. entitled “Association between electromagnetic field exposure and abortion in pregnant women living in Tehran” that is published in International Journal of Reproductive BioMedicine Vol. 14. No. 5. pp: 347-354, May 2016. In this article, the authors evaluated the possible associations between electromagnetic waves exposure level and the rate of miscarriage in pregnant women. The electromagnetic radiation, in this study, had a significant association with the increased abortion in women who were exposed to these radiations. These findings were based on the measurements of electromagnetic waves within the residential locations of the 413 samples, very close to the entrance door of their home, according to the standard instructions of ICNIRP. Over the past several years, our laboratories at the Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC have expanded their focus on studying the health effects of exposure to some common and/or occupational sources of electromagnetic fields (EMFs such as cellular phones (1-9, mobile base stations (10, mobile phone jammers (11, 12, laptop computers (13, radars (2, dentistry cavitrons (14 and MRI (15, 16. Although the paper authored by Abad et al. is a well-structured article and addresses a very challenging issue, it has some major shortcomings. The first shortcoming of this paper comes from this cardinal point that the authors have simply ignored the role of exposure to extremely low frequency EMFs (e.g. exposure of the pregnant women living in houses close to power lines. It is worth noting that the NARDA SRM-3000 used in their study operates in the frequency range of 27MHz-3GHz and cannot measure extremely low frequency EMFs. It is also worth mentioning that previous studies conducted in Iran indicated that the exposure to extremely low frequency electromagnetic fields is probably related to early spontaneous abortions (17

  15. SU-F-T-111: Investigation of the Attila Deterministic Solver as a Supplement to Monte Carlo for Calculating Out-Of-Field Radiotherapy Dose

    Energy Technology Data Exchange (ETDEWEB)

    Mille, M; Lee, C [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (United States); Failla, G [Varian Medical Systems, Gig Harbor, WA (United States)

    2016-06-15

    Purpose: To use the Attila deterministic solver as a supplement to Monte Carlo for calculating out-of-field organ dose in support of epidemiological studies looking at the risks of second cancers. Supplemental dosimetry tools are needed to speed up dose calculations for studies involving large-scale patient cohorts. Methods: Attila is a multi-group discrete ordinates code which can solve the 3D photon-electron coupled linear Boltzmann radiation transport equation on a finite-element mesh. Dose is computed by multiplying the calculated particle flux in each mesh element by a medium-specific energy deposition cross-section. The out-of-field dosimetry capability of Attila is investigated by comparing average organ dose to that which is calculated by Monte Carlo simulation. The test scenario consists of a 6 MV external beam treatment of a female patient with a tumor in the left breast. The patient is simulated by a whole-body adult reference female computational phantom. Monte Carlo simulations were performed using MCNP6 and XVMC. Attila can export a tetrahedral mesh for MCNP6, allowing for a direct comparison between the two codes. The Attila and Monte Carlo methods were also compared in terms of calculation speed and complexity of simulation setup. A key perquisite for this work was the modeling of a Varian Clinac 2100 linear accelerator. Results: The solid mesh of the torso part of the adult female phantom for the Attila calculation was prepared using the CAD software SpaceClaim. Preliminary calculations suggest that Attila is a user-friendly software which shows great promise for our intended application. Computational performance is related to the number of tetrahedral elements included in the Attila calculation. Conclusion: Attila is being explored as a supplement to the conventional Monte Carlo radiation transport approach for performing retrospective patient dosimetry. The goal is for the dosimetry to be sufficiently accurate for use in retrospective

  16. A New Semi-Symmetric Unified Field Theory of the Classical Fields of Gravity and Electromagnetism

    Directory of Open Access Journals (Sweden)

    Suhendro I.

    2007-10-01

    Full Text Available We attempt to present a classical theoretical framework in which the gravitational and electromagnetic fields are unified as intrinsic geometric objects in the space-time manifold. For this purpose, we first present the preliminary geometric considerations dealing with the metric differential geometry of Cartan connections. The unified field theory is then developed as an extension of the general theory of relativity based on a semi- symmetric Cartan connection which is meant to be as close as possible structurally to the symmetric connection of the Einstein-Riemann space-time.

  17. Electromagnetic field effects on cells of the immune system: The role of calcium signalling

    Energy Technology Data Exchange (ETDEWEB)

    Walleczek, J.

    1991-07-01

    During the past decade considerable evidence has accumulated demonstrating the exposures of cells of the immune system to relatively weak extremely-low-frequency (ELF) electromagnetic fields (< 300 Hz) can elicit cellular changes which might be relevant to in-vivo immune activity. However, knowledge about the underlying biological mechanisms by which weak fields induce cellular changes is still very limited. It is generally believed that the cell membrane and Ca{sup 2+} regulated activity is involved in bioactive ELF field-coupling to living systems. This article begins with a short review of the current state of knowledge concerning the effects of nonthermal levels of ELF electromagnetic fields on the biochemistry and activity of immune cells, and then closely examines new results which suggest a role for Ca{sup 2+} in the induction of these cellular field effects. Based on these findings it is proposed that membrane-mediated Ca{sup 2+} signalling processes are involved in the mediation of field effects on the immune system. 64 refs., 2 tabs.

  18. Extremely Low Frequency Electromagnetic Field (ELF-EMF and childhood leukemia near transmission lines: a review

    Directory of Open Access Journals (Sweden)

    P. A. Kokate

    2016-04-01

    Full Text Available This article presents a systematic review of most cited studies from developed countries those shed light on the potential relation between childhood leukemia and extremely low frequency electromagnetic field (ELF-EMF. All the findings of articles critically segregated as per some neglected parameters like number of samples, exposure duration, frequency range, distance from the radiation sources, and location during measurement of magnetic field density near power lines. Literature of major 50 studies are divided according to pooled analysis / meta-analysis, residential zone assessment and case-control studies.

  19. Forced vibration of a carbon nanotube with emission currents in an electromagnetic field

    Science.gov (United States)

    Bulyarskiy, S. V.; Dudin, A. A.; Orlov, A. P.; Pavlov, A. A.; Leont'ev, V. L.

    2017-11-01

    The occurrence of vibrations in a single carbon nanotubes placed in an electromagnetic field through which constant field-emission current passes has been analyzed. It has been shown experimentally that the emission current, along with the constant component, has a variable one that resonates at a certain frequency. Calculations show a relationship between the resonance frequency and the parameters of the whole system and nanotube itself. The conditions under which resonance may occur in the terahertz range of vibration frequencies have been analyzed.

  20. Rigid format alter packets for the analysis of electromagnetic field problems

    Science.gov (United States)

    Spreeuw, E.; Reefman, R. J. B.

    1975-01-01

    The computer program NASTRAN is used to solve electromagnetic field problems. The diffusion equation and the boundary conditions valid for problems of these kinds together with a replacing potential energy function are given. The extent to which an analogy with finite element displacement and temperature approaches holds is indicated. The outputting of complex quantities is made possible after adjustment of standard rigid format 1 input data blocks to module SDR2. The applications made involve the study of the proximity effect in a system of three parallel conductors and the analysis of the magnetic field in the vicinity of the points of contact in circuit breakers.

  1. Transcranial low voltage pulsed electromagnetic fields in patients with treatment-resistant depression

    DEFF Research Database (Denmark)

    Martiny, Klaus Per Juul; Lunde, Marianne; Bech, Per

    2010-01-01

    of a new principle using low-intensity transcranially applied pulsed electromagnetic fields (T-PEMF) in combination with antidepressants in patients with treatment-resistant depression. METHODS: This was a sham-controlled double-blind study comparing 5 weeks of active or sham T-PEMF in patients...... seven separate coils located over the skull that generated an electrical field in tissue with orders of magnitude weaker than those generated by rTMS equipment. RESULTS: Patients on active T-PEMF showed a clinically and statistically significant better outcome than patients treated with sham T...

  2. Analysis of Omni-directivity Error of Electromagnetic Field Probe using Isotropic Antenna

    Directory of Open Access Journals (Sweden)

    Hartansky Rene

    2016-12-01

    Full Text Available This manuscript analyzes the omni-directivity error of an electromagnetic field (EM probe and its dependence on frequency. The global directional characteristic of a whole EM probe consists of three independent directional characteristics of EM sensors - one for each coordinate. The shape of particular directional characteristics is frequency dependent and so is the shape of the whole EM probe’s global directional characteristic. This results in systematic error induced in the measurement of EM fields. This manuscript also contains quantitative formulation of such errors caused by the shape change of directional characteristics for different types of sensors depending on frequency and their mutual arrangement.

  3. Relativistic mass and charge of photons in thermal plasmas through electromagnetic field quantization.

    Science.gov (United States)

    Asenjo, Felipe A; Muñoz, Víctor; Valdivia, J Alejandro

    2010-05-01

    An effective photon mass and equivalent photon charge are calculated for plasmas with finite temperature, by using a second covariant quantization of the electromagnetic field, which is based on a nonlinear magnetofluid unification field formalism. Relativistic effects are considered both in the fluid bulk motion and in the thermal motion. The effective relativistic photon mass is found for transverse and longitudinal photons, while the equivalent relativistic photon charge is obtained for purely transverse photons. Both quantum quantities are the relativistic generalization, at finite temperature, of previous results [Mendonça, et al., Phys. Rev. E 62, 2989 (2000)]. The dependence with temperature is studied in both cases.

  4. Algorithm for the propagation of electromagnetic fields through etalons and crystals.

    Science.gov (United States)

    Zhang, Site; Hellmann, Christian; Wyrowski, Frank

    2017-05-20

    We investigate the propagation of general electromagnetic fields through optical layer structures made of either isotropic or anisotropic media, by using the spectrum-of-plane-waves analysis together with the S-matrix method. We also develop an algorithm based on the fast Fourier transform technique, with a numerically efficient sampling rule. By using this algorithm in combination with other system modeling techniques, we present a few simulation examples, such as field propagation through an isotropic Fabry-Perot etalon, as well as uniaxial crystal slabs with arbitrary orientation and optic axis direction.

  5. Electromagnetic field vulnerability of complex systems – an application of EM topology

    Directory of Open Access Journals (Sweden)

    R. Kanyou Nana

    2008-05-01

    Full Text Available In complex systems like ships or airplanes many tasks vital to the function of the system are executed by electronic equipment. Earlier research Camp (2004 – Nitsch (2005 has shown that there are frequency ranges in many of these systems, in which disturbances in the system will be observed if an external electromagnetic field exceeds a certain amplitude limit. On the basis of a simplified model in which the dominating coupling mechanisms in complex systems are shown, we will present a method which allows to analyze the vulnerability to electromagnetic fields. The method is based on the segmentation of the initial problem into subproblems with respect to the coupling mechanisms. Under the assumption that the obtained classes can be handled separately, the subproblems are solved and superposed to the overall solution. The Electromagnetic Topology Baum (1982 – Lee (1982 is used to solve the subproblems. This leads to a hybrid method combining different solution approaches. The subproblems are decomposed into smaller subproblems with respect to the shielding levels. This procedure allows us to determine the coupled disturbances into the system. Finally the solution is verified with respect to prescripted limits.

  6. Inductive ionospheric solver for magnetospheric MHD simulations

    Directory of Open Access Journals (Sweden)

    H. Vanhamäki

    2011-01-01

    Full Text Available We present a new scheme for solving the ionospheric boundary conditions required in magnetospheric MHD simulations. In contrast to the electrostatic ionospheric solvers currently in use, the new solver takes ionospheric induction into account by solving Faraday's law simultaneously with Ohm's law and current continuity. From the viewpoint of an MHD simulation, the new inductive solver is similar to the electrostatic solvers, as the same input data is used (field-aligned current [FAC] and ionospheric conductances and similar output is produced (ionospheric electric field. The inductive solver is tested using realistic, databased models of an omega-band and westward traveling surge. Although the tests were performed with local models and MHD simulations require a global ionospheric solution, we may nevertheless conclude that the new solution scheme is feasible also in practice. In the test cases the difference between static and electrodynamic solutions is up to ~10 V km−1 in certain locations, or up to 20-40% of the total electric field. This is in agreement with previous estimates. It should also be noted that if FAC is replaced by the ground magnetic field (or ionospheric equivalent current in the input data set, exactly the same formalism can be used to construct an inductive version of the KRM method originally developed by Kamide et al. (1981.

  7. Measurement and analysis of electromagnetic fields from trams, trains and hybrid cars.

    Science.gov (United States)

    Halgamuge, Malka N; Abeyrathne, Chathurika D; Mendis, Priyan

    2010-10-01

    Electricity is used substantially and sources of electric and magnetic fields are, unavoidably, everywhere. The transportation system is a source of these fields, to which a large proportion of the population is exposed. Hence, investigation of the effects of long-term exposure of the general public to low-frequency electromagnetic fields caused by the transportation system is critically important. In this study, measurements of electric and magnetic fields emitted from Australian trams, trains and hybrid cars were investigated. These measurements were carried out under different conditions, locations, and are summarised in this article. A few of the measured electric and magnetic field strengths were significantly lower than those found in prior studies. These results seem to be compatible with the evidence of the laboratory studies on the biological effects that are found in the literature, although they are far lower than international levels, such as those set up in the International Commission on Non-Ionising Radiation Protection guidelines.

  8. Nonlinear electromagnetic fields in 0.5 MHz inductively coupled plasmas

    DEFF Research Database (Denmark)

    Ostrikov, K.N.; Tsakadze, E.L.; Xu, S.

    2003-01-01

    Radial profiles of magnetic fields in the electrostatic (E) and electromagnetic (H) modes of low-frequency (similar to500 kHz) inductively coupled plasmas have been measured using miniature magnetic probes. In the low-power (similar to170 W) E-mode, the magnetic field pattern is purely linear......, with the fundamental frequency harmonics only. After transition to higher-power (similar to1130 W) H-mode, the second-harmonic nonlinear azimuthal magnetic field B-phi(2omega) that is in 4-6 times larger than the fundamental frequency component B-phi(omega), has been observed. A simplified plasma fluid model...... explaining the generation of the second harmonics of the azimuthal magnetic field in the plasma source is proposed. The nonlinear second harmonic poloidal (r-z) rf current generating the azimuthal magnetic field B-phi(2omega) is attributed to nonlinear interactions between the fundamental frequency radial...

  9. A Unified Hamiltonian Solution to Maxwell-Schrodinger Equations for Modeling Electromagnetic Field-Particle Interaction

    CERN Document Server

    Chen, Yongpin P; Jiang, Li Jun; Meng, Min; Wu, Yu Mao; Chew, Weng Cho

    2016-01-01

    A novel unified Hamiltonian approach is proposed to solve Maxwell-Schrodinger equation for modeling the interaction between classical electromagnetic (EM) fields and particles. Based on the Hamiltonian of electromagnetics and quantum mechanics, a unified Maxwell-Schrodinger system is derived by the variational principle. The coupled system is well-posed and symplectic, which ensures energy conserving property during the time evolution. However, due to the disparity of wavelengths of EM waves and that of electron waves, a numerical implementation of the finite-difference time-domain (FDTD) method to the multiscale coupled system is extremely challenging. To overcome this difficulty, a reduced eigenmode expansion technique is first applied to represent the wave function of the particle. Then, a set of ordinary differential equations (ODEs) governing the time evolution of the slowly-varying expansion coefficients are derived to replace the original Schrodinger equation. Finally, Maxwell's equations represented b...

  10. Electromagnetic fields and the public: EMF standards and estimation of risk

    Science.gov (United States)

    Grigoriev, Yury

    2010-04-01

    Mobile communications are a relatively new and additional source of electromagnetic exposure for the population. Standard daily mobile-phone use is known to increase RF-EMF (radiofrequency electromagnetic field) exposure to the brains of users of all ages, whilst mobile-phone base stations, and base station units for cordless phones, can regularly increase the exposures of large numbers of the population to RF-EMF radiation in everyday life. The need to determine appropriate standards stipulating the maximum acceptable short-term and long-term RF-EMF levels encountered by the public, and set such levels as general guidelines, is of great importance in order to help preserve the general public's health and that of the next generation of humanity.

  11. Tilted microstrip phased arrays with improved electromagnetic decoupling for ultrahigh-field magnetic resonance imaging.

    Science.gov (United States)

    Pang, Yong; Wu, Bing; Jiang, Xiaohua; Vigneron, Daniel B; Zhang, Xiaoliang

    2014-12-01

    One of the technical challenges in designing a dedicated transceiver radio frequency (RF) array for MR imaging in humans at ultrahigh magnetic fields is how to effectively decouple the resonant elements of the array. In this work, we propose a new approach using tilted microstrip array elements for improving the decoupling performance and potentially parallel imaging capability. To investigate and validate the proposed design technique, an 8-channel volume array with tilted straight-type microstrip elements was designed, capable for human imaging at the ultrahigh field of 7 Tesla. In this volume transceiver array, its electromagnetic decoupling behavior among resonant elements, RF field penetration to biological samples, and parallel imaging performance were studied through bench tests and in vivo MR imaging experiments. In this specific tilted element array design, decoupling among array elements changes with the tilted angle of the elements and the best decoupling can be achieved at certain tilted angle. In vivo human knee MR images were acquired using the tilted volume array at 7 Tesla for method validation. Results of this study demonstrated that the electromagnetic decoupling between array elements and the B1 field strength can be improved by using the tilted element method in microstrip RF coil array designs at the ultrahigh field of 7T.

  12. Electromagnetic absorption in a multilayered slab model of tissue under near-field exposure conditions.

    Science.gov (United States)

    Chatterjee, I; Hagmann, M J; Gandhi, O P

    1980-01-01

    The electromagnetic energy deposited in a semi-infinite slab model consisting of skin, fat, and muscle layers is calculated for both plane-wave and near-field exposures. The plane-wave spectrum (PWS) approach is used to calculate the energy deposited in the model by fields present due to leakage from equipment using electromagnetic energy. This analysis applies to near-field exposures where coupling of the target to the leakage source can be neglected. Calculations were made for 2,450 MHz, at which frequency the layered slab adequately models flat regions of the human body. Resonant absorption due to layering is examined as a function of the skin and fat thicknesses for plane-wave exposure and as a function of the physical extent of the near-field distribution. Calculations show that for fields that are nearly constant over at least a free-space wavelength, the energy deposition (for skin, fat, and muscle combination that gives resonant absorption) is equal to or less than that resulting from plane-wave exposure, but is appreciably greater than that obtained for a homogeneous muscle slab model.

  13. 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.

  14. Near-field thermal radiation between homogeneous dual uniaxial electromagnetic metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jui-Yung; Basu, Soumyadipta; Yang, Yue; Wang, Liping, E-mail: liping.wang@asu.edu [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States)

    2016-06-07

    Recently, near-field thermal radiation has attracted much attention in several fields since it can exceed the Planck blackbody limit through the coupling of evanescent waves. In this work, near-field radiative heat transfer between two semi-infinite dual uniaxial electromagnetic metamaterials with two different material property sets is theoretically analyzed. The near-field radiative heat transfer is calculated using fluctuational electrodynamics incorporated with anisotropic wave optics. The underlying mechanisms, namely, magnetic hyperbolic mode, magnetic surface polariton, electrical hyperbolic mode, and electrical surface polariton, between two homogeneous dual uniaxial electromagnetic metamaterials are investigated by examining the transmission coefficient and the spectral heat flux. The effect of vacuum gap distance is also studied, which shows that the enhancement at smaller vacuum gap is mainly due to hyperbolic mode and surface plasmon polariton modes. In addition, the results show that the contribution of s-polarized waves is significant and should not be excluded due to the strong magnetic response regardless of vacuum gap distances. The fundamental understanding and insights obtained here will facilitate the finding and application of novel materials for near-field thermal radiation.

  15. Effect of extremely low frequency electromagnetic field on brain histopathology of Caspian Sea Cyprinus carpio.

    Science.gov (United States)

    Samiee, Farzaneh; Samiee, Keivandokht

    2017-01-01

    There is limited research on the effect of electromagnetic field on aquatic organisms, especially freshwater fish species. This study was conducted to evaluate the effect of extremely low frequency electromagnetic field (ELF-EMF) (50 Hz) exposure on brain histopathology of Cyprinus carpio, one of the important species of Caspian Sea with significant economic value. A total of 200 healthy fish were used in this study. They were classified randomly in two groups: sham-exposed group and experimental group, which were exposed to five different magnetic field intensities (0.1, 1, 3, 5, and 7 mT) at two different exposure times (0.5 and 1 h). Histologic results indicate that exposure of C. carpio to artificial ELF-EMF caused severe histopathological changes in the brain at field intensities ≥3 mT leading to brain necrosis. Field intensity and duration of exposure were key parameters in induction of lesion in the brain. Further studies are needed to elucidate exact mechanism of EMF exposure on the brain.

  16. Occupational electromagnetic field exposures associated with sleep quality: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Hui Liu

    Full Text Available Exposure to electromagnetic field (EMF emitted by mobile phone and other machineries concerns half the world's population and raises the problem of their impact on human health. The present study aims to explore the effects of electromagnetic field exposures on sleep quality and sleep duration among workers from electric power plant.A cross-sectional study was conducted in an electric power plant of Zhejiang Province, China. A total of 854 participants were included in the final analysis. The detailed information of participants was obtained by trained investigators using a structured questionnaire, which including socio-demographic characteristics, lifestyle variables, sleep variables and electromagnetic exposures. Physical examination and venous blood collection were also carried out for every study subject.After grouping daily occupational electromagnetic exposure into three categories, subjects with long daily exposure time had a significantly higher risk of poor sleep quality in comparison to those with short daily exposure time. The adjusted odds ratios were 1.68 (95%CI: 1.18, 2.39 and 1.57 (95%CI: 1.10, 2.24 across tertiles. Additionally, among the subjects with long-term occupational exposure, the longer daily occupational exposure time apparently increased the risk of poor sleep quality (OR (95%CI: 2.12 (1.23∼3.66 in the second tertile; 1.83 (1.07∼3.15 in the third tertile. There was no significant association of long-term occupational exposure duration, monthly electric fee or years of mobile-phone use with sleep quality or sleep duration.The findings showed that daily occupational EMF exposure was positively associated with poor sleep quality. It implies EMF exposure may damage human sleep quality rather than sleep duration.

  17. Occupational electromagnetic field exposures associated with sleep quality: a cross-sectional study.

    Science.gov (United States)

    Liu, Hui; Chen, Guangdi; Pan, Yifeng; Chen, Zexin; Jin, Wen; Sun, Chuan; Chen, Chunjing; Dong, Xuanjun; Chen, Kun; Xu, Zhengping; Zhang, Shanchun; Yu, Yunxian

    2014-01-01

    Exposure to electromagnetic field (EMF) emitted by mobile phone and other machineries concerns half the world's population and raises the problem of their impact on human health. The present study aims to explore the effects of electromagnetic field exposures on sleep quality and sleep duration among workers from electric power plant. A cross-sectional study was conducted in an electric power plant of Zhejiang Province, China. A total of 854 participants were included in the final analysis. The detailed information of participants was obtained by trained investigators using a structured questionnaire, which including socio-demographic characteristics, lifestyle variables, sleep variables and electromagnetic exposures. Physical examination and venous blood collection were also carried out for every study subject. After grouping daily occupational electromagnetic exposure into three categories, subjects with long daily exposure time had a significantly higher risk of poor sleep quality in comparison to those with short daily exposure time. The adjusted odds ratios were 1.68 (95%CI: 1.18, 2.39) and 1.57 (95%CI: 1.10, 2.24) across tertiles. Additionally, among the subjects with long-term occupational exposure, the longer daily occupational exposure time apparently increased the risk of poor sleep quality (OR (95%CI): 2.12 (1.23∼3.66) in the second tertile; 1.83 (1.07∼3.15) in the third tertile). There was no significant association of long-term occupational exposure duration, monthly electric fee or years of mobile-phone use with sleep quality or sleep duration. The findings showed that daily occupational EMF exposure was positively associated with poor sleep quality. It implies EMF exposure may damage human sleep quality rather than sleep duration.

  18. Three-dimensional simulation of the electromagnetic ion/ion beam instability: cross field diffusion

    Directory of Open Access Journals (Sweden)

    H. Kucharek

    2000-01-01

    Full Text Available In a system with at least one ignorable spatial dimension charged particles moving in fluctuating fields are tied to the magnetic field lines. Thus, in one-and two-dimensional simulations cross-field diffusion is inhibited and important physics may be lost. We have investigated cross-field diffusion in self-consistent 3-D magnetic turbulence by fully 3-dimensional hybrid simulation (macro-particle ions, massless electron fluid. The turbulence is generated by the electromagnetic ion/ion beam instability. A cold, low density, ion beam with a high velocity stream relative to the background plasma excites the right-hand resonant instability. Such ion beams may be important in the region of the Earth's foreshock. The field turbulence scatters the beam ions parallel as well as perpendicular to the magnetic field. We have determined the parallel and perpendicular diffusion coefficient for the beam ions in the turbulent wave field. The result compares favourably well (within a factor 2 with hard-sphere scattering theory for the cross-field diffusion coefficient. The cross-field diffusion coefficient is larger than that obtained in a static field with a Kolmogorov type spectrum and similar total fluctuation power. This is attributed to the resonant behaviour of the particles in the fluctuating field.

  19. Treatment of Diabetic Foot Ulcers through Systemic Effects of Extremely Low Frequency Electromagnetic Fields

    Science.gov (United States)

    Trejo-Núñez, A. D.; Pérez-Chávez, F.; García-Sánchez, C.; Serrano-Luna, G.; Cañendo-Dorantes, L.

    2008-08-01

    This study was designed to, investigate the healing effects of extremely low frequency electromagnetic fields (ELF-EMF) on diabetic foot ulcers and test two different exposure systems aimed at reducing the ELF-EMF exposure time of patients. In the first system the ELF-EMF were applied to the arm where only 3% of the total blood volume/min circulates at any given time. In the second system the ELF-EMF were applied to the thorax where more than 100% of the total blood volume/minute circulates at any given time. Twenty-six diabetic patients, with superficial neuropathic ulcers unresponsive to medical treatment were included in this preliminary report. In the first group (17 patients), the arm was exposed two hours twice a week to a extremely low frequency electromagnetic field of 0.45-0.9 mTrms, 120 Hz generated inside a solenoid coil of 10.1 cm by 20.5 cm long. In the second group the thorax of 7 patients was exposed 25 minutes twice a week to an electromagnetic field of 0.4-0.85 mTrms, 120 Hz generated in the center of a squared quasi-Helmholtz coil 52 cm by side. One patient was assigned to a placebo configuration of each exposure system with identical appearance as the active equipment but without magnetic field. Patients with deep ulcers, infected ulcers, cancer, or auto-immune disease were excluded. These preliminary results showed that the two exposure systems accelerate the healing process of neuropathic ulcers. Complete healing of the ulcer had a median duration of 90 days in both exposure systems. Therefore thorax exposure where more blood is exposed to ELF-EMF per unit of time was able to reduce 4.8 times the patient treatment time. In those patients assigned to the placebo equipment no healing effects were observed. This study will continue with a parallel, double blind placebo controlled protocol.

  20. Electromagnetic field enhancement and spectrum shaping through plasmonically integrated optical vortices.

    Science.gov (United States)

    Ahn, Wonmi; Boriskina, Svetlana V; Hong, Yan; Reinhard, Björn M

    2012-01-11

    We introduce a new design approach for surface-enhanced Raman spectroscopy (SERS) substrates that is based on molding the optical powerflow through a sequence of coupled nanoscale optical vortices "pinned" to rationally designed plasmonic nanostructures, referred to as Vortex Nanogear Transmissions (VNTs). We fabricated VNTs composed of Au nanodiscs by electron beam lithography on quartz substrates and characterized their near- and far-field responses through combination of computational electromagnetism, and elastic and inelastic scattering spectroscopy. Pronounced dips in the far-field scattering spectra of VNTs provide experimental evidence for an efficient light trapping and circulation within the nanostructures. Furthermore, we demonstrate that VNT integration into periodic arrays of Au nanoparticles facilitates the generation of high E-field enhancements in the VNTs at multiple defined wavelengths. We show that spectrum shaping in nested VNT structures is achieved through an electromagnetic feed-mechanism driven by the coherent multiple scattering in the plasmonic arrays and that this process can be rationally controlled by tuning the array period. The ability to generate high E-field enhancements at predefined locations and frequencies makes nested VNTs interesting substrates for challenging SERS applications. © 2011 American Chemical Society

  1. Monitoring electro-magnetic field in urban areas: new set-ups and results

    Energy Technology Data Exchange (ETDEWEB)

    Lubritto, C.; Petraglia, A.; Paribello, G.; Formosi, R.; Rosa, M. de; Vetromile, C.; Palmieri, A.; D' Onofrio, A. [Seconda Universita di Napoli, Dipt. di Scienze Ambientali, Caserta (Italy); Di Bella, G.; Giannini, V. [Vector Group, Roma (Italy)

    2006-07-01

    In this paper two different set-ups for continuous monitoring of electromagnetic levels are presented: the first one (Continuous Time E.M.F. Monitoring System) is based upon a network of fixed stations, allowing a detailed field monitoring as function of the time; the second one (Mobile Measurements Units) resorts to portable stations mounted on standard bicycles, allowing a positional screening in limited time intervals. For both set-ups a particular attention has been paid to the data management, by means of tools like web geographic information systems (Web-Gis). Moreover the V.I.C.R.E.M./E.L.F. software has been used for a predictive analysis of the electromagnetic field levels along with the geo referenced data coming from the field measurements. Starting from these results it has been realized that there is a need for an efficient and correct action of monitoring and information/formation in this domain, where dis-information or bad information is very often spread in the population, in particular in a field where the process of the appreciation and assessment of risk does not necessarily make use of a rationale, technically-informed procedure, but the judgement is rather based on a personal feeling, which may derive from a limited, unstructured set of information, using a set of qualitative attributes rather than a quantity. (N.C.)

  2. Verification of Electromagnetic Field Measurements via Inter-laboratory Comparison Measurements

    Directory of Open Access Journals (Sweden)

    M. Mann

    2005-01-01

    Full Text Available An inter-laboratory comparison of field strength measurements was conducted in order to verify the comparability of high-frequency electromagnetic field measurements. For this purpose, 17 participating teams hosted by the working group "procedures of exposure determination" of the LAI (Länderausschuss für Immissionsschutz, state committee on immission control determined the field strength at given stations around a hospital situation. At those stations very different signals were generated, such as sine wave signals at 27MHz and 433MHz, signals from a diathermy device in Continuous-Wave (CW and Pulse-Width-Modulation (PWM mode, from a GSM base station at 900MHz and 1800MHz, from a UMTS base station, from a babyphone device and from a DECT cordless phone. This contribution describes the evaluation of the measured values and the approach to the computation of a reference value. Considering various sources of electromagnetic fields in the areas of personal safety at work and of immission control, the most important results are presented and the conclusions drawn are discussed.

  3. Numerical Research on Magnetic Field, Temperature Field and Flow Field During Melting and Directionally Solidifying TiAl Alloys by Electromagnetic Cold Crucible

    Science.gov (United States)

    Chen, Ruirun; Yang, Yaohua; Gong, Xue; Guo, Jingjie; Su, Yanqing; Ding, Hongsheng; Fu, Hengzhi

    2017-12-01

    The electromagnetic cold crucible (EMCC) technique is an effective method to melt and directionally solidify reactive and high-temperature materials without contamination. The temperature field and fluid flow induced by the electromagnetic field are very important for melting and controlling the microstructure. In this article, a 3D EMCC model for calculating the magnetic field in the charges (TiAl alloys) using the T-Ω finite element method was established and verified. Magnetic fields in the charge under different electrical parameters, positions and dimensions of the charge were calculated and analyzed. The calculated results show that the magnetic field concentrates in the skin layer, and the magnetic flux density ( B) increases with increasing of the frequency, charge diameter and current. The maximum B in the charge is affected by the position of the charge in EMCC ( h 1) and the charge height ( h 2), which emerges at the middle of coils ( h c) when the relationship of h c field in the charge. Consequently, the induced uniform electromagnetic stirring weakens the turbulence and improves temperature uniformity in the vicinity of the solid/liquid (S/L) interface, which is beneficial to forming a planar S/L interface during directional solidification. Based on the above conclusions, the TiAlNb alloy was successfully melted with lower power consumption and directionally solidified by the square EMCC.

  4. Phantom pain reduction by low-frequency and low-intensity electromagnetic fields.

    Science.gov (United States)

    Bókkon, István; Till, Attila; Grass, Friedrich; Erdöfi Szabó, Attila

    2011-09-01

    Although various treatments have been presented for phantom pain, there is little proof supporting the benefits of pharmacological treatments, surgery or interventional techniques, electroconvulsive therapy, electrical nerve stimulation, far infrared ray therapy, psychological therapies, etc. Here, we report the preliminary results for phantom pain reduction by low-frequency and intensity electromagnetic fields under clinical circumstances. Our method is called as Electromagnetic-Own-Signal-Treatment (EMOST). Fifteen people with phantom limb pain participated. The patients were treated using a pre-programmed, six sessions. Pain intensity was quantified upon admission using a 0-10 verbal numerical rating scale. Most of the patients (n = 10) reported a marked reduction in the intensity of phantom limb pain. Several patients also reported about improvement in their sleep and mood quality, or a reduction in the frequency of phantom pain after the treatments. No improvements in the reduction of phantom limb pain or sleep and mood improvement were reported in the control group (n = 5). Our nonlinear electromagnetic EMOST method may be a possible therapeutic application in the reduction of phantom limb pain. Here, we also suggest that some of the possible effects of the EMOST may be achieved via the redox balance of the body and redox-related neural plasticity.

  5. Effect of kombucha on some trace element levels in different organs of electromagnetic field exposed rats

    Directory of Open Access Journals (Sweden)

    Ola A. Gharib

    2014-01-01

    Full Text Available Mobile phones have increased exponentially all over the world. The present study was performed to evaluate the effect of kombucha (KT on some trace element levels of brain, spleen and intestine in male albino rats exposed to a 950 MHz electromagnetic field (EMF. Four experimental groups labelled as controls, EMF group, KT group and KT + EMF group were formed with six randomly chosen animals in each group. After EMF exposure for eight weeks and the animals were sacrificed by decapitation. Brain, spleen and intestine samples were collected for trace element analysis. The group of animals subjected to electromagnetic waves caused significant increases in iron copper levels and copper/zinc ratio accompanied with a decrease of zinc level in all studied organs. Combined treatment of kombucha with EMF resulted in a successful attenuation of these adverse effects of EMF. From present findings we can state that kombucha as a supplement has an ameliorative signs against the effects of electromagnetic radiation.

  6. Safety Problems of Electric and Magnetic Fields and Experimental Magnetic Fusion Facilities 5.Electromagnetic Fields in the Workplace

    Science.gov (United States)

    Jonai, Hiroshi; Villanueva, Maria Beatriz G.

    The review addresses the concerns related to extremely low frequency electromagnetic fields (ELF/EMF) in workplaces. The exposure levels and epidemiological studies on cancer, the health effects of working with VDTs (visual display terminals), and the malfunction of cardiac pacemakers are described. The association of EMF exposure and cancer or disorders from VDT work cannot be considered conclusive. The information on the exposure level and effect of EMF on cardiac pacemakers should be disseminated in workplaces. Risk communication program on EMF is urgent for countermeasures against worker anxiety.

  7. Bats avoid radar installations: could electromagnetic fields deter bats from colliding with wind turbines?

    Directory of Open Access Journals (Sweden)

    Barry Nicholls

    Full Text Available Large numbers of bats are killed by collisions with wind turbines, and there is at present no direct method of reducing or preventing this mortality. We therefore determine whether the electromagnetic radiation associated with radar installations can elicit an aversive behavioural response in foraging bats. Four civil air traffic control (ATC radar stations, three military ATC radars and three weather radars were selected, each surrounded by heterogeneous habitat. Three sampling points matched for habitat type and structure, dominant vegetation species, altitude and surrounding land class were located at increasing distances from each station. A portable electromagnetic field meter measured the field strength of the radar at three distances from the source: in close proximity (2 volts/metre, an intermediate point within line of sight of the radar (200-400 m and with an EMF strength 400 m and registering an EMF of zero v/m. At each radar station bat activity was recorded three times with three independent sampling points monitored on each occasion, resulting in a total of 90 samples, 30 of which were obtained within each field strength category. At these sampling points, bat activity was recorded using an automatic bat recording station, operated from sunset to sunrise. Bat activity was significantly reduced in habitats exposed to an EMF strength of greater than 2 v/m when compared to matched sites registering EMF levels of zero. The reduction in bat activity was not significantly different at lower levels of EMF strength within 400 m of the radar. We predict that the reduction in bat activity within habitats exposed to electromagnetic radiation may be a result of thermal induction and an increased risk of hyperthermia.

  8. Anisotropic inflation with a non-minimally coupled electromagnetic field to gravity

    Science.gov (United States)

    Adak, Muzaffer; Akarsu, Özgür; Dereli, Tekin; Sert, Özcan

    2017-11-01

    We consider the non-minimal model of gravity in Y(R) F2-form. We investigate a particular case of the model, for which the higher order derivatives are eliminated but the scalar curvature R is kept to be dynamical via the constraint YRFmnFmn =‑2/κ2. The effective fluid obtained can be represented by interacting electromagnetic field and vacuum depending on Y(R), namely, the energy density of the vacuum tracks R while energy density of the conventional electromagnetic field is dynamically scaled with the factor Y(R)/2. We give exact solutions for anisotropic inflation by assuming the volume scale factor of the Universe exhibits a power-law expansion. The directional scale factors do not necessarily exhibit power-law expansion, which would give rise to a constant expansion anisotropy, but expand non-trivially and give rise to a non-monotonically evolving expansion anisotropy that eventually converges to a non-zero constant. Relying on this fact, we discuss the anisotropic e-fold during the inflation by considering observed scale invariance in CMB and demanding the Universe to undergo the same amount of e-folds in all directions. We calculate the residual expansion anisotropy at the end of inflation, though as a result of non-monotonic behaviour of expansion anisotropy all the axes of the Universe undergo the same of amount of e-folds by the end of inflation. We also discuss the generation of the modified electromagnetic field during the first few e-folds of the inflation and its persistence against to the vacuum till end of inflation.

  9. Electric field computation analysis for the Electric Field Detector (EFD) on board the China Seismic-Electromagnetic Satellite (CSES)

    Science.gov (United States)

    Diego, P.; Bertello, I.; Candidi, M.; Mura, A.; Coco, I.; Vannaroni, G.; Ubertini, P.; Badoni, D.

    2017-11-01

    The floating potential variability of the Electric Field Detector (EFD) probes, on board the Chinese Seismo-Electromagnetic Satellite (CSES), has been modeled, and the effects of several structural and environmental elements have been determined. The expected floating potentials of the probes are computed considering the ambient ionospheric plasma parameter variations. In addition, the ion collection variability, due to the different probe attitudes along the orbit, and its effect on each floating potential, are considered. Particular attention is given to the analysis of the shadow produced by the stubs, in order to determine the artificial electric field introduced by instrumental effects which has to be subtracted from the real measurements. The modulation of the altered electric field, due to the effect on shadowing of the ion drift, as measured by the ESA satellite Swarm A in a similar orbit, is also modeled. Such simulations are made in preparation of real EFD data analysis performed during the upcoming flight of CSES.

  10. Application of an induced field sensor for assessment of electromagnetic exposure from compact fluorescent lamps.

    Science.gov (United States)

    Nadakuduti, Jagadish; Douglas, Mark; Capstick, Myles; Kühn, Sven; Kuster, Niels

    2012-02-01

    The development of scientifically sound instrumentation, methods, and procedures for the electromagnetic exposure assessment of compact fluorescent lamps (CFLs) is investigated. The incident and induced fields from 11 CFLs have been measured in the 10 kHz-1 MHz range, and they are compared with the levels for incandescent and light emitting diode (LED) bulbs. Commercially available equipment was used to measure the incident fields, while a novel sensor was built to assess the induced fields in humans. Incident electric field levels significantly exceed the International Commission on Non-Ionizing Radiation Protection (ICNIRP) reference levels at close distances for some sources, while the induced fields are within the ICNIRP basic restrictions. This demonstrates the importance of assessing the induced fields rather than the incident fields for these sources. Maximum current densities for CFLs are comparable to the limits (in the range of 9% to 56%), demonstrating the need for measurements to establish compliance. For the frequency range investigated, the induced fields were found to be considerably higher for CFLs than for incandescent light bulbs, while the exposure from the two LED bulbs was low. The proposed instrumentation and methods offer several advantages over an existing measurement standard, and the measurement uncertainty is significantly better than the assessment of electric and magnetic fields at close distances. Copyright © 2011 Wiley Periodicals, Inc.

  11. Electromagnetic field of a charge moving in a cold magnetized plasma.

    Science.gov (United States)

    Galyamin, Sergey N; Kapshtan, Dmitry Ya; Tyukhtin, Andrey V

    2013-01-01

    The present paper addresses the electromagnetic field generated by a point charge or a small charged particle bunch moving with constant velocity in a cold magnetized plasma, along the external magnetic field. Attention is focused on the case of ultrarelativistic motion. The field surrounding the point charge is investigated both analytically and numerically. In the analytical study, we obtain rigorous decomposition of the field into quasistatic and wave components. Beating behavior in the far-field zone and harmonic behavior in the vicinity of the charge trajectory are found using suitable approximate approaches. The transverse component of the electric field exhibits a strong (inversely proportional) singularity on the charge trajectory, while the longitudinal components of both the electric and magnetic fields exhibit a weaker (logarithmic) singularity. An efficient numerical approach is developed to calculate the field for arbitrary parameters. An efficient algorithm for calculating the fields of small bunches with different forms is also presented, using a thin charged disk and a charged cylinder as representative examples.

  12. Coupling Mechanism of Electromagnetic Field and Thermal Stress on Drosophila melanogaster

    OpenAIRE

    ZHANG Zi-yan; Zhang,Jing; Yang, Chuan-Jun; Lian, Hui-Yong; Yu, Hui; Huang, Xiao-Mei; Cai, Peng

    2016-01-01

    Temperature is an important factor in research on the biological effects of extremely low-frequency electromagnetic field (ELF-EMF), but interactions between ELF-EMF and temperature remain unknown. The effects of ELF-EMF (50 Hz, 3 mT) on the lifespan, locomotion, heat shock response (HSR), and oxidative stress (OS) of Canton-Special (CS) and mutant w1118 flies were investigated at 25?C and 35?C (thermal stress). Results showed that thermal stress accelerated the death rates of CS and w1118 fl...

  13. Frame dragging, vorticity and electromagnetic fields in axially symmetric stationary spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, L [Escuela de Fisica, Universidad Central de Venezuela, Caracas, Venezuela (Venezuela); Gonzalez, G A [Escuela de Fisica, Universidad Industrial de Santander, AA 678, Bucaramanga (Colombia); Pachon, L A [Escuela de Fisica, Universidad Industrial de Santander, AA 678, Bucaramanga (Colombia); Laboratorio de AstronomIa y Fisica Teorica (LAFT), Departamento de Fisica, Facultad de Ciencias, La Universidad del Zulia, Maracaibo, 4004 (Venezuela); Rueda, J A [Escuela de Fisica, Universidad Industrial de Santander, AA 678, Bucaramanga (Colombia)

    2006-04-07

    We present a general study about the relation between the vorticity tensor and the Poynting vector of the electromagnetic field for axially symmetric stationary electrovacuum metrics. The obtained expressions allow us to understand the role of the Poynting vector in the dragging of inertial frames. The particular case of the rotating massive charged magnetic dipole is analysed in detail. In addition, the electric and magnetic parts of the Weyl tensor are calculated and the link between the latter and the vorticity is established. Then we show that, in the vacuum case, the necessary and sufficient condition for the vanishing of the magnetic part is that the spacetime be static.

  14. Modeling of Electromagnetic Fields in Parallel-Plane Structures: A Unified Contour-Integral Approach

    Directory of Open Access Journals (Sweden)

    M. Stumpf

    2017-04-01

    Full Text Available A unified reciprocity-based modeling approach for analyzing electromagnetic fields in dispersive parallel-plane structures of arbitrary shape is described. It is shown that the use of the reciprocity theorem of the time-convolution type leads to a global contour-integral interaction quantity from which novel both time- and frequency-domain numerical schemes can be arrived at. Applications of the numerical method concerning the time-domain radiated interference and susceptibility of parallel-plane structures are discussed and illustrated on numerical examples.

  15. The second-order theory of electromagnetic hot ion beam instabilities. [in interplanetary magnetic field

    Science.gov (United States)

    Gary, S. P.; Tokar, R. L.

    1985-01-01

    The present investigation is concerned with the application of a second-order theory for electromagnetic instabilities in a collisionless plasma to two modes which resonate with hot ion beams. The application of the theory is strictly limited to the linear growth phase. However, the application of the theory may be extended to obtain a description of the beam at postsaturation if the wave-beam resonance is sufficiently broad in velocity space. Under the considered limitations, it is shown that, as in the cold beam case, the fluctuating fields do not gain appreciable momentum and that the primary exchange of momentum is between the beam and main component.

  16. Field test and theoretical analysis of electromagnetic pulse propagation velocity on crossbonded cable systems

    DEFF Research Database (Denmark)

    Jensen, Christian Flytkjær; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2014-01-01

    In this paper, the electromagnetic pulse propagation velocity on a three-phase cable system, consisting of three single core (SC) cables in flat formation with an earth continuity conductor is under study. The propagation velocity is an important parameter for most travelling wave off- and online...... fault location methods and needs to be exactly known for optimal performance of these algorithm types. Field measurements are carried out on a 6.9 km and a 31.4 km 245 kV crossbonded cable system, and the results are analysed using the modal decomposition theory. Several ways for determining...

  17. NUMERICAL MODELING OF THE ELECTROMAGNETIC FIELD WITHIN THE INDUCTION HARDENING OF INNER CYLINDRICAL SURFACES

    Directory of Open Access Journals (Sweden)

    C. O. MOLNAR

    2008-05-01

    Full Text Available The paper presents the numerical modeling ofelectromagnetic field within the induction hardening ofinner cylindrical surface. The numerical computation hasbeen done by means of finite element method in order tosolve the coupled electromagnetic and thermal fieldquestion. The obtained results provide informationregarding the heating process taking into account therelative movement between the inductor and workpiece,the over heating of thin layers, the geometricalconfiguration of the inductor as well the technologicalrequirements correlated with electrical parameters andrepresents an active tool to setup the induction heatingequipment in order to get best results during hardeningprocess .

  18. Enhancement of Optical Nonlinearities in Composite Media and Structures via Local Fields and Electromagnetic Coupling Effects

    Science.gov (United States)

    Smith, David D.

    2002-01-01

    This talk will review the linear and nonlinear optical properties of metal nanoparticles and dielectric microparticles, with an emphasis on local field effects, and whispering gallery modes (WGMs), as well as the conjunction of these two effects for enhanced Raman. In particular, enhanced optical properties that result from electromagnetic coupling effects will be discussed in the context of Mie scattering from concentric spheres and bispheres. Predictions of mode splitting and photonic bandgaps in micro-spheres will be presented and will be shown to be analogous to effects that occur in coupled resonator optical waveguides (CROW). Slow and fast light in SCISSOR / CROW configurations will also be discussed.

  19. Use of non-ionizing electromagnetic fields for the treatment of cancer.

    Science.gov (United States)

    Jimenez, Hugo; Blackman, Carl; Lesser, Glenn; Debinski, Waldemar; Chan, Michael; Sharma, Sambad; Watabe, Kounosuke; Lo, Hui-Wen; Thomas, Alexandra; Godwin, Dwayne; Blackstock, William; Mudry, Albert; Posey, James; O'Connor, Rodney; Brezovich, Ivan; Bonin, Keith; Kim-Shapiro, Daniel; Barbault, Alexandre; Pasche, Boris

    2018-01-01

    Cancer treatment and treatment options are quite limited in circumstances such as when the tumor is inoperable, in brain cancers when the drugs cannot penetrate the blood-brain-barrier, or when there is no tumor-specific target for generation of effective therapeutic antibodies. Despite the fact that electromagnetic fields (EMF) in medicine have been used for therapeutic or diagnostic purposes, the use of non-ionizing EMF for cancer treatment is a new emerging concept. Here we summarize the history of EMF from the 1890's to the novel and new innovative methods that target and treat cancer by non-ionizing radiation.

  20. Optimization of a therapeutic electromagnetic field (EMF) to retard breast cancer tumor growth and vascularity

    OpenAIRE

    Cameron, Ivan L.; Markov, Marko S; Hardman, W Elaine

    2014-01-01

    Background This study provided additional data on the effects of a therapeutic electromagnetic field (EMF) device on growth and vascularization of murine 16/C mammary adenocarcinoma cells implanted in C3H/HeJ mice. Methods The therapeutic EMF device generated a defined 120 Hz semi sine wave pulse signal of variable intensity. Murine 16/C mammary adenocarcinoma tumor fragments were implanted subcutaneously between the scapulae of syngeneic C3H mice. Once the tumor grew to 100 mm3, daily EMF tr...