WorldWideScience

Sample records for wave electromagnetic radiation

  1. Radiation and propagation of electromagnetic waves

    CERN Document Server

    Tyras, George; Declaris, Nicholas

    1969-01-01

    Radiation and Propagation of Electromagnetic Waves serves as a text in electrical engineering or electrophysics. The book discusses the electromagnetic theory; plane electromagnetic waves in homogenous isotropic and anisotropic media; and plane electromagnetic waves in inhomogenous stratified media. The text also describes the spectral representation of elementary electromagnetic sources; the field of a dipole in a stratified medium; and radiation in anisotropic plasma. The properties and the procedures of Green's function method of solution, axial currents, as well as cylindrical boundaries a

  2. Electromagnetic radiation accompanying gravitational waves from black hole binaries

    Science.gov (United States)

    Dolgov, A.; Postnov, K.

    2017-09-01

    The transition of powerful gravitational waves, created by the coalescence of massive black hole binaries, into electromagnetic radiation in external magnetic fields is considered. In contrast to the previous calculations of the similar effect we study the realistic case of the gravitational radiation frequency below the plasma frequency of the surrounding medium. The gravitational waves propagating in the plasma constantly create electromagnetic radiation dragging it with them, despite the low frequency. The plasma heating by the unattenuated electromagnetic wave may be significant in hot rarefied plasma with strong magnetic field and can lead to a noticeable burst of electromagnetic radiation with higher frequency. The graviton-to-photon conversion effect in plasma is discussed in the context of possible electromagnetic counterparts of GW150914 and GW170104.

  3. THE GENERATION OF THERMOELASTIC STRESS WAVES BY IMPULSIVE ELECTROMAGNETIC RADIATION.

    Science.gov (United States)

    ELECTROMAGNETIC RADIATION , ABSORPTION), (*STRESSES, ELECTROMAGNETIC RADIATION ), SURFACE PROPERTIES, INTERACTIONS, HEAT TRANSFER, ELASTIC PROPERTIES, ELECTROMAGNETIC PULSES, LASERS, MATHEMATICAL ANALYSIS, BOUNDARY VALUE PROBLEMS, SOLIDS

  4. Cellular and molecular effects of electromagnetic radiation and sonic waves

    OpenAIRE

    Patricia Froes Meyer; Oscar Ariel Ronzio; Adenilson de Souza da Fonseca; Sebastiao David Santos-Filho; Mario Bernardo-Filho

    2013-01-01

    Electromagnetic radiation (in the form of pulsed magnetic fields, radiofrequency and intense pulsed light) and mechanical agents (such as sonic waves) have been used in physical therapy. The aim of this study was to assess the effects of low-intensity magnetic fields, sonic and radiofrequency waves, and intense pulsed light on the survival of Escherichia coli cultures and on the electrophoretic mobility of plasmid DNA. Exponentially growing E. coli AB1157 cultures and plasmid DNA samples were...

  5. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis...

  6. Electromagnetic Waves

    OpenAIRE

    Blok, H.; van den Berg, P.M.

    2011-01-01

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

  7. Low frequency electromagnetic radiation from gravitational waves generated by neutron stars

    Science.gov (United States)

    Jones, Preston; Gretarsson, Andri; Singleton, Douglas

    2017-12-01

    We investigate the possibility of observing very low frequency (VLF) electromagnetic radiation produced from the vacuum by gravitational waves. We review the calculations leading to the possibility of vacuum conversion of gravitational waves into electromagnetic waves and show how this process evades the well-known prohibition against particle production from gravitational waves. Using Newman-Penrose scalars, we estimate the luminosity of this proposed electromagnetic counterpart radiation coming from gravitational waves produced by neutron star oscillations. The detection of electromagnetic counterpart radiation would provide an indirect way of observing gravitational radiation with future spacecraft missions, especially lunar orbiting probes.

  8. Electromagnetic induction and radiation-induced abnormality of wave propagation in excitable media

    Science.gov (United States)

    Ma, Jun; Wu, Fuqiang; Hayat, Tasawar; Zhou, Ping; Tang, Jun

    2017-11-01

    Continuous wave emitting from sinus node of the heart plays an important role in wave propagating among cardiac tissue, while the heart beating can be terminated when the target wave is broken into turbulent states by electromagnetic radiation. In this investigation, local periodical forcing is applied on the media to induce continuous target wave in the improved cardiac model, which the effect of electromagnetic induction is considered by using magnetic flux, then external electromagnetic radiation is imposed on the media. It is found that target wave propagation can be blocked to stand in a local area and the excitability of media is suppressed to approach quiescent but homogeneous state when electromagnetic radiation is imposed on the media. The sampled time series for membrane potentials decrease to quiescent state due to the electromagnetic radiation. It could accounts for the mechanism of abnormality in heart failure exposed to continuous electromagnetic field.

  9. The Characteristics of Frequency Spectrum of Radiated Electromagnetic Waves with AC Discharge Progress in Liquid Nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Park, K.S.; Yoon, D.H.; Lee, S.H.; Kim, K.C.; Lee, K.S. [Yeungnam University, Gyeongsan (Korea); Lee, H.D. [LG Industrial Systems Co., Ltd., Cheongju (Korea); Kim, C.M. [Kyungwoon University, Kumi (Korea); Choi, B.J. [Sorabol College, Gyeongju (Korea)

    2003-03-01

    In this paper, a relationship between AC discharge progress and the radiated electromagnetic waves was investigated by measuring electromagnetic waves using a biconical antenna and a spectrum analyzer. The frequency spectrum of the radiated electromagnetic waves were measured at the atmospheric pressure in liquid nitrogen(LN{sub 2}) during partial discharges progressed by AC high voltage in nonuniform electric field. From the results of this study, a new method was introduced for measurement and analysis of the radiated electromagnetic waves with discharge progress in LN{sub 2}. Besides, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress could be possible. It is considered that these results obtained from this investigation may be used as fundamental data for diagnosis and prediction of electric insulations about superconducting and cryogenic power equipments. (author). 14 refs., 7 figs.

  10. Remarks on the Radiative Transfer Approach to Scattering of Electromagnetic Waves in Layered Random Media

    Science.gov (United States)

    2010-03-01

    AFRL-RY-HS-TR-2010-0029 REMARKS ON THE RADIATIVE TRANSFER APPROACH TO SCATTERING OF ELECTROMAGNETIC WAVES IN LAYERED RANDOM MEDIA...TRANSFER APPROACH TO SCATTERING OF ELECTROMAGNETIC WAVES IN LAYERED RANDOM MEDIA 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT NUMBER 5c. PROGRAM...Beckmann and A. Spizzichino. The Scattering of Electromagnetic Waves from Rough Surfaces. Artech House, Norwood, Massachusetts, 1987. [3] G. S. Brown. A

  11. Cellular and molecular effects of electromagnetic radiation and sonic waves

    Directory of Open Access Journals (Sweden)

    Patricia Froes Meyer

    2013-07-01

    Full Text Available Electromagnetic radiation (in the form of pulsed magnetic fields, radiofrequency and intense pulsed light and mechanical agents (such as sonic waves have been used in physical therapy. The aim of this study was to assess the effects of low-intensity magnetic fields, sonic and radiofrequency waves, and intense pulsed light on the survival of Escherichia coli cultures and on the electrophoretic mobility of plasmid DNA. Exponentially growing E. coli AB1157 cultures and plasmid DNA samples were exposed to these physical agents and 0.9% NaCl (negative control and SnCl2 (positive control solutions. Aliquots of the cultures were diluted and spread onto a solidified rich medium. The colony-forming units were counted after overnight incubation and the survival fraction was calculated. Agarose gel electrophoresis was performed to visualise and quantify the plasmid topological forms. The results suggest that these agents do not alter the survival of E. coli cells or plasmid DNA electrophoresis mobility. Moreover, they do not protect against the lesive action of SnCl2. These physical agents therefore had no cytotoxic or genotoxic effects under the conditions studied.

  12. Controlling Energy Radiations of Electromagnetic Waves via Frequency Coding Metamaterials.

    Science.gov (United States)

    Wu, Haotian; Liu, Shuo; Wan, Xiang; Zhang, Lei; Wang, Dan; Li, Lianlin; Cui, Tie Jun

    2017-09-01

    Metamaterials are artificial structures composed of subwavelength unit cells to control electromagnetic (EM) waves. The spatial coding representation of metamaterial has the ability to describe the material in a digital way. The spatial coding metamaterials are typically constructed by unit cells that have similar shapes with fixed functionality. Here, the concept of frequency coding metamaterial is proposed, which achieves different controls of EM energy radiations with a fixed spatial coding pattern when the frequency changes. In this case, not only different phase responses of the unit cells are considered, but also different phase sensitivities are also required. Due to different frequency sensitivities of unit cells, two units with the same phase response at the initial frequency may have different phase responses at higher frequency. To describe the frequency coding property of unit cell, digitalized frequency sensitivity is proposed, in which the units are encoded with digits "0" and "1" to represent the low and high phase sensitivities, respectively. By this merit, two degrees of freedom, spatial coding and frequency coding, are obtained to control the EM energy radiations by a new class of frequency-spatial coding metamaterials. The above concepts and physical phenomena are confirmed by numerical simulations and experiments.

  13. Ion Acceleration by the Radiation Pressure of Slow Electromagnetic Wave

    CERN Document Server

    Bulanov, S V; Kando, M; Pegoraro, F; Bulanov, S S; Geddes, C G R; Schroeder, C; Esarey, E; Leemans, W

    2012-01-01

    When the ions are accelerated by the radiation pressure of the laser pulse, their velocity can not exceed the laser group velocity, in the case when it is less than the speed of light in vacuum. This is demonstrated in two cases corresponding to the thin foil target irradiated by a high intensity laser light and to the hole boring by the laser pulse in the extended plasma accompanied by the collisionless shock wave formation. It is found that the beams of accelerated at the collisionless shock wave front ions are unstable against the Buneman-lke and the Weibel-like instabilities which result in the ion energy spectrum broadening.

  14. Effects of Millimeter-Wave Electromagnetic Radiation on the Experimental Model of Migraine.

    Science.gov (United States)

    Sivachenko, I B; Medvedev, D S; Molodtsova, I D; Panteleev, S S; Sokolov, A Yu; Lyubashina, O A

    2016-02-01

    Effects of millimeter-wave electromagnetic radiation (40 GHz frequency, 0.01 mW power) on the spontaneous fi ring of convergent neurons of the spinal trigeminal nucleus and their responses to electrical stimulation of the dura mater were studied in neurophysiological experiments on rats. Irradiation of the area of cutaneous receptive fields of spinal trigeminal nucleus reversibly inhibited both spontaneous discharges and activity induced by electrical stimulation of the dura mater. The second and third exposures to electromagnetic radiation with an interval of 10 min were ineffective. These results suggest that suppression of neuronal excitability in the spinal trigeminal ganglion can be a mechanism of the anti-migraine effects of electromagnetic radiation observed in clinical practice.

  15. Monitoring dynamic reactions of red blood cells to UHF electromagnetic waves radiation using a novel micro-imaging technology.

    Science.gov (United States)

    Ruan, Ping; Yong, Junguang; Shen, Hongtao; Zheng, Xianrong

    2012-12-01

    Multiple state-of-the-art techniques, such as multi-dimensional micro-imaging, fast multi-channel micro-spetrophotometry, and dynamic micro-imaging analysis, were used to dynamically investigate various effects of cell under the 900 MHz electromagnetic radiation. Cell changes in shape, size, and parameters of Hb absorption spectrum under different power density electromagnetic waves radiation were presented in this article. Experimental results indicated that the isolated human red blood cells (RBCs) do not have obviously real-time responses to the ultra-low density (15 μW/cm(2), 31 μW/cm(2)) electromagnetic wave radiation when the radiation time is not more than 30 min; however, the cells do have significant reactions in shape, size, and the like, to the electromagnetic waves radiation with power densities of 1 mW/cm(2) and 5 mW/cm(2). The data also reveal the possible influences and statistical relationships among living human cell functions, radiation amount, and exposure time with high-frequency electromagnetic waves. The results of this study may be significant on protection of human being and other living organisms against possible radiation affections of the high-frequency electromagnetic waves.

  16. Spectral and angular radiation characteristics of a charged particle in the plane monochromatic electromagnetic wave

    Directory of Open Access Journals (Sweden)

    Nikolay S. Akintsov

    2015-12-01

    Full Text Available Relying upon the solution of the relativistic equation of charged-particle motion that was obtained by Rukhadze et al., the spectral and angular characteristics of ultra-relativistic intensive radiation of a relativistic charged particle have been studied, the particle being linearly accelerated by a superpower laser pulse. The case where the particle propagates in vacuum without brake light was examined. The interaction of the charged particle with the large-amplitude ultra-short laser pulse was analyzed in details using the relativistic consideration. Formulae for the average radiated power of the relativistic charged particle, depending on the initial conditions, the electromagnetic-wave amplitude, intensity and polarization were obtained. For the case where the laser pulse can be represented by a monochromatic plane wave, analytical expressions for the radiation characteristics were put forward and the phase-angular distributions of relativistic radiated power and intensity were found. The Fourier transform of the electric-intensity radiation field of the charged particle and the particle's spectral density radiation in the field of a plane monochromatic wave for different types of polarization (linear and circular ones were determined.

  17. Primordial Gravitational Waves and Rescattered Electromagnetic Radiation in the Cosmic Microwave Background

    CERN Document Server

    Kim, Dong-Hoon

    2016-01-01

    Understanding the interaction of primordial gravitational waves (GWs) with the Cosmic Microwave Background (CMB) plasma is important for observational cosmology. In this article, we provide an analysis of an effect apparently overlooked as yet. We consider a single free electric charge and suppose that it can be agitated by primordial GWs propagating through the CMB plasma, resulting in periodic, regular motion along particular directions. Light reflected by the charge will be partially polarized, and this will imprint a characteristic pattern on the CMB. We study this effect by considering a simple model in which anisotropic incident electromagnetic (EM) radiation is rescattered by a charge sitting in spacetime perturbed by GWs and becomes polarized. As the charge is driven to move along particular directions, we calculate its dipole moment to determine the leading-order rescattered EM radiation. The Stokes parameters of the rescattered radiation exhibit a net linear polarization. We investigate how this pol...

  18. Electromagnetic ultrasonic guided waves

    CERN Document Server

    Huang, Songling; Li, Weibin; Wang, Qing

    2016-01-01

    This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

  19. Latitudinal dependence of nonlinear interaction between electromagnetic ion cyclotron wave and radiation belt relativistic electrons

    Science.gov (United States)

    Su, Zhenpeng; Zhu, Hui; Xiao, Fuliang; Zheng, Huinan; Shen, Chao; Wang, Yuming; Wang, Shui

    2013-06-01

    Electromagnetic ion cyclotron (EMIC) waves are long suggested to account for the rapid loss of radiation belt relativistic electrons. Here we perform both theoretical analysis and numerical simulation to comprehensively investigate the nonlinear interaction between EMIC wave and relativistic electrons. In particular, we emphasize the dependence of nonlinear processes on the electron initial latitude. The nonlinear phase trapping yields negative equatorial pitch angle transport, with efficiency varying over the electron initial latitude, implying that it can increase the loss rate predicted by quasilinear theory. The nonlinear channel effect phase bunching produces positive equatorial pitch angle transport, less dependent on the electron initial latitude, suggesting that it can decrease the loss rate predicted by quasilinear theory. The nonlinear cluster effect phase bunching alternately causes positive and negative equatorial pitch angle transport, quasi-periodically dependent on the electron initial latitude, suggesting that it can either decrease or increase the loss rate predicted by the quasilinear theory. Such latitudinal dependence of nonlinear processes should be taken into account in the evaluation of radiation belt electron loss rate driven by EMIC waves.

  20. Possible standoff detection of ionizing radiation using high-power THz electromagnetic waves

    Science.gov (United States)

    Nusinovich, Gregory S.; Sprangle, Phillip; Romero-Talamas, Carlos A.; Rodgers, John; Pu, Ruifeng; Kashyn, Dmytro G.; Antonsen, Thomas M., Jr.; Granatstein, Victor L.

    2012-06-01

    Recently, a new method of remote detection of concealed radioactive materials was proposed. This method is based on focusing high-power short wavelength electromagnetic radiation in a small volume where the wave electric field exceeds the breakdown threshold. In the presence of free electrons caused by ionizing radiation, in this volume an avalanche discharge can then be initiated. When the wavelength is short enough, the probability of having even one free electron in this small volume in the absence of additional sources of ionization is low. Hence, a high breakdown rate will indicate that in the vicinity of this volume there are some materials causing ionization of air. To prove this concept a 0.67 THz gyrotron delivering 200-300 kW power in 10 microsecond pulses is under development. This method of standoff detection of concealed sources of ionizing radiation requires a wide range of studies, viz., evaluation of possible range, THz power and pulse duration, production of free electrons in air by gamma rays penetrating through container walls, statistical delay time in initiation of the breakdown in the case of low electron density, temporal evolution of plasma structure in the breakdown and scattering of THz radiation from small plasma objects. Most of these issues are discussed in the paper.

  1. Cardiovascular Responses to Electromagnetic Radiation

    African Journals Online (AJOL)

    Dr Olaleye Samuel

    fatigue. ABSTRACT. Electromagnetic signaling has recently greatly increased due to mobile telephony and computers some of which radiate much and have wide spectra. The radiations are also reflected and thus form standing waves with incoming ones. In cities both the direct and reflected radiations form complex ...

  2. COHERENCE PROPERTIES OF ELECTROMAGNETIC RADIATION,

    Science.gov (United States)

    ELECTROMAGNETIC RADIATION , COHERENT SCATTERING), (*COHERENT SCATTERING, ELECTROMAGNETIC RADIATION ), LIGHT, INTERFERENCE, INTENSITY, STATISTICAL FUNCTIONS, QUANTUM THEORY, BOSONS, INTERFEROMETERS, CHINA

  3. A new formulation of electromagnetic wave scattering using an on-surface radiation boundary condition approach

    Science.gov (United States)

    Kriegsmann, Gregory A.; Taflove, Allen; Umashankar, Koradar R.

    1987-01-01

    A new formulation of electromagnetic wave scattering by convex, two-dimensional conducting bodies is reported. This formulation, called the on-surface radiation condition (OSRC) approach, is based upon an expansion of the radiation condition applied directly on the surface of a scatterer. It is now shown that application of a suitable radiation condition directly on the surface of a convex conducting scatterer can lead to substantial simplification of the frequency-domain integral equation for the scattered field, which is reduced to just a line integral. For the transverse magnetic case, the integrand is known explicitly. For the transverse electric case, the integrand can be easily constructed by solving an ordinary differential equation around the scatterer surface contour. Examples are provided which show that OSRC yields computed near and far fields which approach the exact results for canonical shapes such as the circular cylinder, square cylinder, and strip. Electrical sizes for the examples are ka = 5 and ka = 10. The new OSRC formulation of scattering may present a useful alternative to present integral equation and uniform high-frequency approaches for convex cylinders larger than ka = 1. Structures with edges or corners can also be analyzed, although more work is needed to incorporate the physics of singular currents at these discontinuities. Convex dielectric structures can also be treated using OSRC.

  4. Consideration of radiated electromagnetic wave from partial discharge based on half-wave dipole antenna model; Hanhacho dipole ni motozuita bubun hoden ni yoru hosha denjiha no kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, T.; Okubo, H. [Nagoya University, Nagoya (Japan); Hikita, M. [Kyushu Institute of Technology, Kitakyushu (Japan)

    1997-07-20

    Partial discharge (PD) may take place due to residual defects like metallic particles in SF6 gas insulated power apparatus such as GIS. However, the signal of PD occurring in SF6 gas is very weak and susceptible to external noises in air. Moreover, because of the complicated mechanism of PD, the radiation property of electromagnetic wave from PD has not been clarified, yet. Therefore, it is hard to distinguish the PD signal in SF6 gas from the external noises. From the above points of view, we have been investigating the radiation mechanism of electromagnetic wave from PD. We measured the polarization characteristics of electromagnetic wave radiated from PD in comparison with that of half-wave dipole antennas. The polarization characteristics of PD was explained by the theory of half-wave dipole antenna, rather than that of an infinitesimal dipole antenna. Moreover, we compared the power spectrum received from PD measured by a biconical antenna with that received from the half-wave dipole antenna or infinitesimal dipole. It was found that the power spectrum for PD also corresponded to that for the half-wave dipole antenna with 50cm length. 17 refs., 8 figs.

  5. Electromagnetic Radiation Analysis

    Science.gov (United States)

    1978-04-10

    A methodology is given for determining whether electromagnetic radiation of sufficient strength to cause performance degradation to the test item...exists at the test item location. The results of an electromagnetic radiation effects test are used to identify the radio frequencies and electromagnetic ... radiation levels to which the test item is susceptible. Further, using a test bed, comparisons are made with the representative signal levels to

  6. Electromagnetic wave energy converter

    Science.gov (United States)

    Bailey, R. L. (Inventor)

    1973-01-01

    Electromagnetic wave energy is converted into electric power with an array of mutually insulated electromagnetic wave absorber elements each responsive to an electric field component of the wave as it impinges thereon. Each element includes a portion tapered in the direction of wave propagation to provide a relatively wideband response spectrum. Each element includes an output for deriving a voltage replica of the electric field variations intercepted by it. Adjacent elements are positioned relative to each other so that an electric field subsists between adjacent elements in response to the impinging wave. The electric field results in a voltage difference between adjacent elements that is fed to a rectifier to derive dc output power.

  7. [A Compact Source of Terahertz Radiation Based on Interaction of Electrons in à Quantum Well with an Electromagnetic Wave of a Corrugated Waveguide].

    Science.gov (United States)

    Shchurova, L Yu; Namiot, V A; Sarkisyan, D R

    2015-01-01

    Coherent sources of electromagnetic waves in the terahertz frequency range are very promising for various applications, including biology and medicine. In this paper we propose a scheme of a compact terahertz source, in which terahertz radiation is generated due to effective interaction of electrons in a quantum well with an electromagnetic wave of a corrugated waveguide. We have shown that the generation of electromagnetic waves with a frequency of 1012 sec(-1) and an output power of up to 25. mW is possible in the proposed scheme.

  8. "Hearing" Electromagnetic Waves

    Science.gov (United States)

    Rojo, Marta; Munoz, Juan

    2014-01-01

    In this work, an educational experience is described in which a microwave communication link is used to make students aware that all electromagnetic waves have the same physical nature and properties. Experimental demonstrations are linked to theoretical concepts to increase comprehension of the physical principles underlying electromagnetic…

  9. Universal morphologies of fluid interfaces deformed by the radiation pressure of acoustic or electromagnetic waves.

    Science.gov (United States)

    Bertin, N; Chraïbi, H; Wunenburger, R; Delville, J-P; Brasselet, E

    2012-12-14

    We unveil the generation of universal morphologies of fluid interfaces by radiation pressure regardless of the nature of the wave, whether acoustic or optical. Experimental observations reveal interface deformations endowed with steplike features that are shown to result from the interplay between the wave propagation and the shape of the interface. The results are supported by numerical simulations and a quantitative interpretation based on the waveguiding properties of the field is provided.

  10. REFLECTION OF ELECTROMAGNETIC WAVES FROM SOUND WAVES

    Science.gov (United States)

    The reflection of electromagnetic waves normally incident on the wavefronts of a semi-infinite standing sound wave is discussed. By analogy with the...with the sound frequency. An experiment is described in which the Bragg reflection of 3 cm electromagnetic waves from a standing sound wave beneath a water surface is observed.

  11. Metamaterial electromagnetic wave absorbers.

    Science.gov (United States)

    Watts, Claire M; Liu, Xianliang; Padilla, Willie J

    2012-06-19

    The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also their promise for applications. A particular branch-the metamaterial perfect absorber (MPA)-has garnered interest due to the fact that it can achieve unity absorptivity of electromagnetic waves. Since its first experimental demonstration in 2008, the MPA has progressed significantly with designs shown across the electromagnetic spectrum, from microwave to optical. In this Progress Report we give an overview of the field and discuss a selection of examples and related applications. The ability of the MPA to exhibit extreme performance flexibility will be discussed and the theory underlying their operation and limitations will be established. Insight is given into what we can expect from this rapidly expanding field and future challenges will be addressed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Electromagnetic radiation detector

    Science.gov (United States)

    Benson, Jay L.; Hansen, Gordon J.

    1976-01-01

    An electromagnetic radiation detector including a collimating window, a cathode member having a photoelectric emissive material surface angularly disposed to said window whereby radiation is impinged thereon at acute angles, an anode, separated from the cathode member by an evacuated space, for collecting photoelectrons emitted from the emissive cathode surface, and a negatively biased, high transmissive grid disposed between the cathode member and anode.

  13. 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...

  14. Coherent Thz Electromagnetic Radiation Emission as a Shock Wave Diagnostic and Probe of Ultrafast Phase Transformations

    Science.gov (United States)

    Reed, Evan J.; Armstrong, Michael R.; Kim, Ki-Yong; Glownia, James H.; Howard, William M.; Piner, Edwin L.; Roberts, John C.

    2009-12-01

    We present the first experimental observations of terahertz frequency radiation emitted when a terahertz frequency acoustic wave propagates past an interface between materials of differing piezoelectric coefficients. We show that this fundamentally new phenomenon can be used to probe structural properties of thin films. Then, we present molecular dynamics simulations showing that detectable THz frequency radiation can be emitted when a wurtzite structure crystal transforms to a rocksalt structure under shock compression on picosecond timescales. We show that information about the kinetics of the transformation is contained in the time-dependence of the THz field.

  15. Nonlinear waves and coherent structures in quasi-neutral plasmas excited by external electromagnetic radiation

    Science.gov (United States)

    Tzenov, Stephan I.

    2017-12-01

    Starting from the Vlasov-Maxwell equations describing the dynamics of various species in a quasi-neutral plasma, an exact relativistic hydrodynamic closure for a special type of water-bag distribution satisfying the Vlasov equation has been derived. It has been shown that the set of equations for the macroscopic hydrodynamic variables coupled to the wave equations for the self-consistent electromagnetic field is fully equivalent to the Vlasov-Maxwell system. Based on the method of multiple scales, a system comprising a vector nonlinear Schrodinger equation for the transverse envelopes of the self-consistent plasma wakefield, coupled to a scalar nonlinear Schrodinger equation for the electron current velocity envelope, has been derived. Using the method of formal series of Dubois-Violette, a traveling wave solution of the derived set of coupled nonlinear Schrodinger equations in the case of circular wave polarization has been obtained. This solution is represented as a ratio of two formal Volterra series. The terms of these series can be calculated explicitly to every desired order.

  16. Electromagnetic waves, gravitational waves and the prophets who predicted them

    OpenAIRE

    Papachristou, Costas J.

    2016-01-01

    Using non-excessively-technical language and written in informal style, this article introduces the reader to the concepts of electromagnetic and gravitational waves and recounts the prediction of existence of these waves by Maxwell and Einstein, respectively. The issue of gravitational radiation is timely in view of the recent announcement of the detection of gravitational waves by the LIGO scientific team.

  17. Electromagnetic waves in stratified media

    CERN Document Server

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

    2013-01-01

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

  18. Nanofocusing of electromagnetic radiation

    DEFF Research Database (Denmark)

    Gramotnev, D. K.; Bozhevolnyi, Sergey I.

    2014-01-01

    Nanofocusing of electromagnetic radiation, that is, reducing the cross sections of propagating optical modes far beyond the diffraction limit in dielectric media, can be achieved in tapered metal-dielectric waveguides that support surface plasmon-polariton modes. Although the main principles...

  19. Propagation of SLF/ELF electromagnetic waves

    CERN Document Server

    Pan, Weiyan

    2014-01-01

    This book deals with the SLF/ELF wave propagation, an important branch of electromagnetic theory. The SLF/ELF wave propagation theory is well applied in earthquake electromagnetic radiation, submarine communication, thunderstorm detection, and geophysical prospecting and diagnostics. The propagation of SLF/ELF electromagnetic waves is introduced in various media like the earth-ionospheric waveguide, ionospheric plasma, sea water, earth, and the boundary between two different media or the stratified media. Applications in the earthquake electromagnetic radiation and the submarine communications are also addressed. This book is intended for scientists and engineers in the fields of radio propagation and EM theory and applications. Prof. Pan is a professor at China Research Institute of Radiowave Propagation in Qingdao (China). Dr. Li is a professor at Zhejiang University in Hangzhou (China).

  20. Lorentz-Abraham-Dirac versus Landau-Lifshitz radiation friction force in the ultrarelativistic electron interaction with electromagnetic wave (exact solutions).

    Science.gov (United States)

    Bulanov, Sergei V; Esirkepov, Timur Zh; Kando, Masaki; Koga, James K; Bulanov, Stepan S

    2011-11-01

    When the parameters of electron-extreme power laser interaction enter the regime of dominated radiation reaction, the electron dynamics changes qualitatively. The adequate theoretical description of this regime becomes crucially important with the use of the radiation friction force either in the Lorentz-Abraham-Dirac form, which possesses unphysical runaway solutions, or in the Landau-Lifshitz form, which is a perturbation valid for relatively low electromagnetic wave amplitude. The goal of the present paper is to find the limits of the Landau-Lifshitz radiation force applicability in terms of the electromagnetic wave amplitude and frequency. For this, a class of the exact solutions to the nonlinear problems of charged particle motion in the time-varying electromagnetic field is used.

  1. 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.

  2. Wave propagation in electromagnetic media

    CERN Document Server

    Davis, Julian L

    1990-01-01

    This is the second work of a set of two volumes on the phenomena of wave propagation in nonreacting and reacting media. The first, entitled Wave Propagation in Solids and Fluids (published by Springer-Verlag in 1988), deals with wave phenomena in nonreacting media (solids and fluids). This book is concerned with wave propagation in reacting media-specifically, in electro­ magnetic materials. Since these volumes were designed to be relatively self­ contained, we have taken the liberty of adapting some of the pertinent material, especially in the theory of hyperbolic partial differential equations (concerned with electromagnetic wave propagation), variational methods, and Hamilton-Jacobi theory, to the phenomena of electromagnetic waves. The purpose of this volume is similar to that of the first, except that here we are dealing with electromagnetic waves. We attempt to present a clear and systematic account of the mathematical methods of wave phenomena in electromagnetic materials that will be readily accessi...

  3. Scattering of light and other electromagnetic radiation

    CERN Document Server

    Kerker, Milton

    1969-01-01

    The Scattering of Light and Other Electromagnetic Radiation discusses the theory of electromagnetic scattering and describes some practical applications. The book reviews electromagnetic waves, optics, the interrelationships of main physical quantities and the physical concepts of optics, including Maxwell's equations, polarization, geometrical optics, interference, and diffraction. The text explains the Rayleigh2 theory of scattering by small dielectric spheres, the Bessel functions, and the Legendre functions. The author also explains how the scattering functions for a homogenous sphere chan

  4. Electromagnetic radiation from beam-plasma instabilities

    Science.gov (United States)

    Pritchett, P. L.; Dawson, J. M.

    1983-01-01

    A computer simulation is developed for the generation of electromagnetic radiation in an electron beam-plasma interaction. The plasma is treated as a two-dimensional finite system, and effects of a continuous nonrelativistic beam input are accounted for. Three momentum and three field components are included in the simulation, and an external magnetic field is excluded. EM radiation generation is possible through interaction among Langmuir oscillations, ion-acoustic waves, and the electromagnetic wave, producing radiation perpendicular to the beam. The radiation is located near the plasma frequency, and polarized with the E component parallel to the beam. The scattering of Langmuir waves caused by ion-acoustic fluctuations generates the radiation. Comparison with laboratory data for the three-wave interactions shows good agreement in terms of the radiation levels produced, which are small relative to the plasma thermal energy.

  5. Focusing of electromagnetic waves

    Energy Technology Data Exchange (ETDEWEB)

    Dhayalan, V.

    1996-12-31

    The focusing of electromagnetic waves inside a slab has been examined together with two special cases in which the slab is reduced to a single interface or a single medium. To that end the exact solutions for the fields inside a layered medium have been used, given in terms of the outside current source in order to obtain the solutions for the focused electric field inside a slab. Both exact and asymptotic solutions of the problem have been considered, and the validity of the latter has been discussed. The author has developed a numerical algorithm for evaluation of the diffraction integral with special emphasis on reducing the computing time. The numerical techniques in the paper can be readily applied to evaluate similar diffraction integrals occurring e.g. in microstrip antennas. 46 refs.

  6. Relativistically strong electromagnetic radiation in a plasma

    Science.gov (United States)

    Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Kiriyama, H.; Kondo, K.

    2016-03-01

    Physical processes in a plasma under the action of relativistically strong electromagnetic waves generated by high-power lasers have been briefly reviewed. These processes are of interest in view of the development of new methods for acceleration of charged particles, creation of sources of bright hard electromagnetic radiation, and investigation of macroscopic quantum-electrodynamical processes. Attention is focused on nonlinear waves in a laser plasma for the creation of compact electron accelerators. The acceleration of plasma bunches by the radiation pressure of light is the most efficient regime of ion acceleration. Coherent hard electromagnetic radiation in the relativistic plasma is generated in the form of higher harmonics and/or electromagnetic pulses, which are compressed and intensified after reflection from relativistic mirrors created by nonlinear waves. In the limit of extremely strong electromagnetic waves, radiation friction, which accompanies the conversion of radiation from the optical range to the gamma range, fundamentally changes the behavior of the plasma. This process is accompanied by the production of electron-positron pairs, which is described within quantum electrodynamics theory.

  7. A Method and an Apparatus for Generating a Phase-Modulated Wave Front of Electromagnetic Radiation

    DEFF Research Database (Denmark)

    2002-01-01

    The present invention provides a method and a system for generating a phase-modulated wave front. According to the present invention, the spatial phase-modulation is not performed on the different parts of the wave front individually as in known POSLMs. Rather, the spatial phase-modulation of the...

  8. Radiation of terahertz electromagnetic waves from build-in nano Josephson junctions of cuprate high-T(c) superconductors.

    Science.gov (United States)

    Lin, Shi-Zeng; Hu, Xiao

    2011-04-01

    The nano-scale intrinsic Josephson junctions in highly anisotropic cuprate superconductors have potential for generation of terahertz electromagnetic waves. When the thickness of a superconductor sample is much smaller than the wavelength of electromagnetic waves in vacuum, the superconductor renders itself as a cavity. Unlike conventional lasers, the presence of the cavity does not guarantee a coherent emission because of the internal degree of freedom of the superconductivity phase in long junctions. We study the excitation of terahertz wave by solitons in a stack of intrinsic Josephson junctions, especially for relatively short junctions. Coherent emission requires a rectangular configuration of solitons. However such a configuration is unstable against weak fluctuations, contrarily solitons favor a triangular lattice corresponding to an out-phase oscillation of electromagnetic waves. To utilize the cavity, we propose to use an array of stacks of short intrinsic Josephson junctions to generate powerful terahertz electromagnetic waves. The cavity synchronizes the plasma oscillation in different stacks and the emission intensity is predicted to be proportional to the number of stacks squared.

  9. Gravitational scattering of electromagnetic radiation

    Science.gov (United States)

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

    1980-01-01

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

  10. Conical electromagnetic radiation flux concentrator

    Science.gov (United States)

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  11. Parametric Instabilities of Electromagnetic Waves in Plasmas,

    Science.gov (United States)

    A simple formalism for the parametric decay of an intense, coherent electromagnetic wave into an electrostatic wave and scattered electromagnetic ... waves in a homogeneous plasma is developed. Various instabilities including Brillouin and Raman backscattering, Compton scattering, filamentation and

  12. Influence of electromagnetic waves produced by an amplitude ...

    African Journals Online (AJOL)

    This article presents a one dimensional modeling of the influence of electromagnetic waves on the electric power delivered by a silicon solar cell under monochromatic illumination in steady state. The electromagnetic waves are produced by an amplitude modulation radio antenna of 2MW power of radiation and located at a ...

  13. A Study on Suppression of Electromagnetic Radiation Noise from Wireless Module in Millimeter-Wave Band by Using Alumina Containing Carbon Black

    Science.gov (United States)

    Takase, Yasuharu; Hashimoto, Osamu; Matsumoto, Kouta; Kumada, Taketo

    The unwanted electromagnetic(EM) radiation wave generated from the wireless module in millimeter-wave band used for the car radar influences some error and performance degradation of electronic equipments. In this paper, to reduce this unwanted EM wave, a optimal design to add the function of EM wave absorption to the lid for the module is examined. Therefore the alumina containing carbon black is used as a wave absorption material of the lid. The absorption of 20dB or more is obtained as a measured result with the cover added the EM wave absorption function in 60GHz. Furthermore, we analyzed the wireless module in millimeter-wave band by using the designed material for the lid. It is clarified that the radiation and the reflection electric power are greatly suppressed by loss electric power of the lid. Therefore, the effective data for suppressing the unwanted EM radiation noise from wireless module in millimeter-wave band can be provided.

  14. Effect of electromagnetic waves on human reproduction.

    Science.gov (United States)

    Wdowiak, Artur; Mazurek, Paweł A; Wdowiak, Anita; Bojar, Iwona

    2017-03-31

    Electromagnetic radiation (EMR) emitting from the natural environment, as well as from the use of industrial and everyday appliances, constantly influence the human body. The effect of this type of energy on living tissues may exert various effects on their functioning, although the mechanisms conditioning this phenomenon have not been fully explained. It may be expected that the interactions between electromagnetic radiation and the living organism would depend on the amount and parameters of the transmitted energy and type of tissue exposed. Electromagnetic waves exert an influence on human reproduction by affecting the male and female reproductive systems, the developing embryo, and subsequently, the foetus. Knowledge concerning this problem is still being expanded; however, all the conditionings of human reproduction still remain unknown. The study presents the current state of knowledge concerning the problem, based on the latest scientific reports.

  15. 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...

  16. Radiation leakage from electromagnetic oven

    Directory of Open Access Journals (Sweden)

    Abdurrahman Khalil

    2015-10-01

    Results & Discussions: The measurements have been done at some houses in Erbil city, according to the source of background radiation exist before measuring data. Our data compared with standard safe range of radiation data. Results showed that there is radiation leak form all type of electromagnetic oven and all at the order of safety compared with standard value.

  17. 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.

  18. Landau levels for electromagnetic wave

    CERN Document Server

    Zyuzin, Vladimir A

    2016-01-01

    In this paper we show that the frequencies of propagating electromagnetic wave (photon) in rotating dielectric media obey Landau quantization. We show that the degeneracy of right and left helicities of photons is broken on the lowest Landau level. In spatially homogeneous system this level is shown to be helical, i.e. left and right helical photons counter-propagate.

  19. Electromagnetic van Kampen waves

    Energy Technology Data Exchange (ETDEWEB)

    Ignatov, A. M., E-mail: aign@fpl.gpi.ru [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

    2017-01-15

    The theory of van Kampen waves in plasma with an arbitrary anisotropic distribution function is developed. The obtained solutions are explicitly expressed in terms of the permittivity tensor. There are three types of perturbations, one of which is characterized by the frequency dependence on the wave vector, while for the other two, the dispersion relation is lacking. Solutions to the conjugate equations allowing one to solve the initial value problem are analyzed.

  20. Classical electromagnetic radiation

    CERN Document Server

    Heald, Mark A

    2012-01-01

    Newly corrected, this highly acclaimed text is suitable for advanced physics courses. The author presents a very accessible macroscopic view of classical electromagnetics that emphasizes integrating electromagnetic theory with physical optics. The survey follows the historical development of physics, culminating in the use of four-vector relativity to fully integrate electricity with magnetism.

  1. 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

  2. High latitude electromagnetic plasma wave emissions

    Science.gov (United States)

    Gurnett, D. A.

    1983-01-01

    The principal types of electromagnetic plasma wave emission produced in the high latitude auroral regions are reviewed. Three types of radiation are described: auroral kilometric radiation, auroral hiss, and Z mode radiation. Auroral kilometric radiation is a very intense radio emission generated in the free space R-X mode by electrons associated with the formation of discrete auroral arcs in the local evening. Theories suggest that this radiation is an electron cyclotron resonance instability driven by an enhanced loss cone in the auroral acceleration region at altitudes of about 1 to 2 R sub E. Auroral hiss is a somewhat weaker whistler mode emission generated by low energy (100 eV to 10 keV) auroral electrons. The auroral hiss usually has a V shaped frequency time spectrum caused by a freqency dependent beaming of the whistler mode into a conical beam directed upward or downward along the magnetic field.

  3. Nanocomposites for electromagnetic radiation protection

    Science.gov (United States)

    Petrunin, V. F.

    2016-12-01

    Specific features that characterize nanoparticles and which are due to their small size and allow one to enhance the interaction between the electromagnetic radiation and nanostructured materials and to develop the effective protection of man and equipment against harmful uncontrolled radiation are reported. Examples of the development of nanocomposite radar absorbing materials that can be used for protection of man and equipment are presented.

  4. Nanocomposites for electromagnetic radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Petrunin, V. F., E-mail: VFPetrunin@mephi.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2016-12-15

    Specific features that characterize nanoparticles and which are due to their small size and allow one to enhance the interaction between the electromagnetic radiation and nanostructured materials and to develop the effective protection of man and equipment against harmful uncontrolled radiation are reported. Examples of the development of nanocomposite radar absorbing materials that can be used for protection of man and equipment are presented.

  5. Millimeter waves: acoustic and electromagnetic.

    Science.gov (United States)

    Ziskin, Marvin C

    2013-01-01

    This article is the presentation I gave at the D'Arsonval Award Ceremony on June 14, 2011 at the Bioelectromagnetics Society Annual Meeting in Halifax, Nova Scotia. It summarizes my research activities in acoustic and electromagnetic millimeter waves over the past 47 years. My earliest research involved acoustic millimeter waves, with a special interest in diagnostic ultrasound imaging and its safety. For the last 21 years my research expanded to include electromagnetic millimeter waves, with a special interest in the mechanisms underlying millimeter wave therapy. Millimeter wave therapy has been widely used in the former Soviet Union with great reported success for many diseases, but is virtually unknown to Western physicians. I and the very capable members of my laboratory were able to demonstrate that the local exposure of skin to low intensity millimeter waves caused the release of endogenous opioids, and the transport of these agents by blood flow to all parts of the body resulted in pain relief and other beneficial effects. Copyright © 2012 Wiley Periodicals, Inc.

  6. Measurement of advanced electromagnetic radiation

    OpenAIRE

    Bajlo, Darko

    2017-01-01

    For the purpose of detecting advanced electromagnetic radiation predicted by Wheeler-Feynman absorber theory for the case of incomplete absorption of retarded electromagnetic radiation, pulses in duration of 6 ns to 24 ns, wavelength from 91 cm to 200 cm where supplied to three different transmitting antennas. Detection was done with a λ/20 monopole antenna in the advanced time window at a time 2r/c before the arrival of the center of the retarded pulse. At distances ranging from 430 cm to 18...

  7. Science 101: Can Electromagnetic Waves Affect Emotions?

    Science.gov (United States)

    Robertson, Bill

    The answer to this month's question, "Can electromagnetic waves affect emotions," is yes. Wherever there are electromagnetic (EM) waves (basically everywhere!), there is the potential for them directly or indirectly to affect the emotions. But what about the likely motivation behind the originally-posed question? Can EM waves affect your…

  8. Electromagnetic wave theory for boundary-value problems an advanced course on analytical methods

    CERN Document Server

    Eom, Hyo J

    2004-01-01

    Electromagnetic wave theory is based on Maxwell's equations, and electromagnetic boundary-value problems must be solved to understand electromagnetic scattering, propagation, and radiation. Electromagnetic theory finds practical applications in wireless telecommunications and microwave engineering. This book is written as a text for a two-semester graduate course on electromagnetic wave theory. As such, Electromagnetic Wave Theory for Boundary-Value Problems is intended to help students enhance analytic skills by solving pertinent boundary-value problems. In particular, the techniques of Fourier transform, mode matching, and residue calculus are utilized to solve some canonical scattering and radiation problems.

  9. Detailed observations of the source of terrestrial narrowband electromagnetic radiation

    Science.gov (United States)

    Kurth, W. S.

    1982-01-01

    Detailed observations are presented of a region near the terrestrial plasmapause where narrowband electromagnetic radiation (previously called escaping nonthermal continuum radiation) is being generated. These observations show a direct correspondence between the narrowband radio emissions and electron cyclotron harmonic waves near the upper hybrid resonance frequency. In addition, electromagnetic radiation propagating in the Z-mode is observed in the source region which provides an extremely accurate determination of the electron plasma frequency and, hence, density profile of the source region. The data strongly suggest that electrostatic waves and not Cerenkov radiation are the source of the banded radio emissions and define the coupling which must be described by any viable theory.

  10. Electromagnetic Wave Absorption Coating Material with Self-Healing Properties.

    Science.gov (United States)

    Wang, Ya-Min; Pan, Min; Liang, Xiang-Yong; Li, Bang-Jing; Zhang, Sheng

    2017-11-02

    Electromagnetic wave absorption coatings can effectively minimize electromagnetic radiation and are widely used in the military and civil field. However, even small scratches on the coating can lead to a large decline of absorption ability and bring serious consequences. To enhance the lifetime of electromagnetic wave absorbing coating, a kind of self-healing electromagnetic wave absorbing coating is developed by introducing host-guest interactions between the absorbing fillers and polymer matrix. After being damaged, the cracks on this coating can be healed completely with the aid of small amounts of water. Simultaneously, the electromagnetic absorbing ability of the coating is restored along with the self-healing process. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Classical electromagnetic radiation of the Dirac electron

    Science.gov (United States)

    Lanyi, G.

    1973-01-01

    A wave-function-dependent four-vector potential is added to the Dirac equation in order to achieve conservation of energy and momentum for a Dirac electron and its emitted electromagnetic field. The resultant equation contains solutions which describe transitions between different energy states of the electron. As a consequence it is possible to follow the space-time evolution of such a process. This evolution is shown in the case of the spontaneous emission of an electromagnetic field by an electron bound in a hydrogen-like atom. The intensity of the radiation and the spectral distribution are calculated for transitions between two eigenstates. The theory gives a self-consistent deterministic description of some simple radiation processes without using quantum electrodynamics or the correspondence principle.

  12. [Applications of electromagnetic radiation in medicine].

    Science.gov (United States)

    Miłowska, Katarzyna; Grabowska, Katarzyna; Gabryelak, Teresa

    2014-05-08

    Recent decades have been devoted to the intense search for the response to questions related to the impact of radiation on the human body. Due to the growing fashion for a healthy lifestyle, increasing numbers of works about the alleged dangers of electromagnetic waves and diseases that they cause appeared. However, the discoveries of 20th century, and knowledge of the properties of electromagnetic radiation have allowed to broaden the horizons of the use of artificial sources of radiation in many fields of science and especially in medicine. The aim of this paper is to show that although excessive radiation or high doses are dangerous to the human body, its careful and controlled use, does not pose a threat, and it is often necessary in therapy. The possibility of using ionizing radiation in radiotherapy, isotope diagnostics or medical imaging, and non-ionizing radiation in the treatment for dermatological disorders and cancers will be presented. The unique properties of synchrotron radiation result in using it on a large scale in the diagnosis of pathological states by imaging methods.

  13. Applications of electromagnetic radiation in medicine

    Directory of Open Access Journals (Sweden)

    Katarzyna Miłowska

    2014-05-01

    Full Text Available Recent decades have been devoted to the intense search for the response to questions related to the impact of radiation on the human body. Due to the growing fashion for a healthy lifestyle, increasing numbers of works about the alleged dangers of electromagnetic waves and diseases that they cause appeared. However, the discoveries of 20th century, and knowledge of the properties of electromagnetic radiation have allowed to broaden the horizons of the use of artificial sources of radiation in many fields of science and especially in medicine. The aim of this paper is to show that although excessive radiation or high doses are dangerous to the human body, its careful and controlled use, does not pose a threat, and it is often necessary in therapy. The possibility of using ionizing radiation in radiotherapy, isotope diagnostics or medical imaging, and non-ionizing radiation in the treatment for dermatological disorders and cancers will be presented. The unique properties of synchrotron radiation result in using it on a large scale in the diagnosis of pathological states by imaging methods.

  14. Compton Sources of Electromagnetic Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Geoffrey Krafft,Gerd Priebe

    2011-01-01

    When a relativistic electron beam interacts with a high-field laser beam, intense and highly collimated electromagnetic radiation will be generated through Compton scattering. Through relativistic upshifting and the relativistic Doppler effect, highly energetic polarized photons are radiated along the electron beam motion when the electrons interact with the laser light. For example, X-ray radiation can be obtained when optical lasers are scattered from electrons of tens-of-MeV beam energy. Because of the desirable properties of the radiation produced, many groups around the world have been designing, building, and utilizing Compton sources for a wide variety of purposes. In this review article, we discuss the generation and properties of the scattered radiation, the types of Compton source devices that have been constructed to date, and the prospects of radiation sources of this general type. Due to the possibilities of producing hard electromagnetic radiation in a device that is small compared to the alternative storage ring sources, it is foreseen that large numbers of such sources may be constructed in the future.

  15. Exponential beams of electromagnetic radiation

    OpenAIRE

    Bialynicki-Birula, Iwo; Bialynicka-Birula, Zofia

    2006-01-01

    We show that in addition to well known Bessel, Hermite-Gauss, and Laguerre-Gauss beams of electromagnetic radiation, one may also construct exponential beams. These beams are characterized by a fall-off in the transverse direction described by an exponential function of rho. Exponential beams, like Bessel beams, carry definite angular momentum and are periodic along the direction of propagation, but unlike Bessel beams they have a finite energy per unit beam length. The analysis of these beam...

  16. Plasma scattering of electromagnetic radiation

    CERN Document Server

    Sheffield, John

    1975-01-01

    Plasma Scattering of Electromagnetic Radiation covers the theory and experimental application of plasma scattering. The book discusses the basic properties of a plasma and of the interaction of radiation with a plasma; the relationship between the scattered power spectrum and the fluctuations in plasma density; and the incoherent scattering of low-temperature plasma. The text also describes the constraints and problems that arise in the application of scattering as a diagnostic technique; the characteristic performance of various dispersion elements, image dissectors, and detectors; and the ge

  17. System engineering study of electrodynamic tether as a spaceborne generator and radiator of electromagnetic waves in the ULF/ELF frequency band

    Science.gov (United States)

    Estes, Robert D.

    1987-01-01

    An electrodynamic tether deployed from a satellite in low-Earth orbit can perform, if properly instrumented, as a partially self-powered generator of electromagnetic waves in the ULF/ELF band, potentially at power levels high enough to be of practical use. Two basic problems are examined. The first is that of the level of wave power that the system can be expected to generate in the ULF/ELF radiation band. The second major question is whether an electrodynamic tethered satellite system for transmitting waves can be made partially self-powering so that power requirements for drag compensation can be met within economical constraints of mass, cost, and complexity. The theoretical developments and the system applications study are presented. The basic design criteria, the drag-compensation method, the effects on the propagation paths from orbit to Earth surface of high-altitude nuclear debris patches, and the estimate of masses and sizes are covered. An outline of recommended analytical work, to be performed as a follow-on to the present study, is contained.

  18. Anisotropic conducting films for electromagnetic radiation applications

    Science.gov (United States)

    Cavallo, Francesca; Lagally, Max G.; Rojas-Delgado, Richard

    2015-06-16

    Electronic devices for the generation of electromagnetic radiation are provided. Also provided are methods for using the devices to generate electromagnetic radiation. The radiation sources include an anisotropic electrically conducting thin film that is characterized by a periodically varying charge carrier mobility in the plane of the film. The periodic variation in carrier mobility gives rise to a spatially varying electric field, which produces electromagnetic radiation as charged particles pass through the film.

  19. Efficient transformer for electromagnetic waves

    Science.gov (United States)

    Miller, R.B.

    A transformer structure for efficient transfer of electromagnetic energy from a transmission line to an unmatched load provides voltage multiplication and current division by a predetermined constant. Impedance levels are transformed by the square of that constant. The structure includes a wave splitter, connected to an input transmission device and to a plurality of output transmission devices. The output transmission devices are effectively connected in parallel to the input transmission device. The output transmission devices are effectively series connected to provide energy to a load. The transformer structure is particularly effective in increasing efficiency of energy transfer through an inverting convolute structure by capturing and transferring energy losses from the inverter to the load.

  20. Electromagnetic Radiation Interface System and Method

    National Research Council Canada - National Science Library

    Steinbrecher, Donald H

    2005-01-01

    .... The termination section may comprise an electrical resistance for capturing substantially all the electromagnetic wave energy received by each respective bristle to thereby prevent reflections...

  1. Electromagnetic-radiation absorption by water

    Science.gov (United States)

    Lunkenheimer, P.; Emmert, S.; Gulich, R.; Köhler, M.; Wolf, M.; Schwab, M.; Loidl, A.

    2017-12-01

    Why does a microwave oven work? How does biological tissue absorb electromagnetic radiation? Astonishingly, we do not have a definite answer to these simple questions because the microscopic processes governing the absorption of electromagnetic waves by water are largely unclarified. This absorption can be quantified by dielectric loss spectra, which reveal a huge peak at a frequency of the exciting electric field of about 20 GHz and a gradual tailing off toward higher frequencies. The microscopic interpretation of such spectra is highly controversial and various superpositions of relaxation and resonance processes ascribed to single-molecule or molecule-cluster motions have been proposed for their analysis. By combining dielectric, microwave, THz, and far-infrared spectroscopy, here we provide nearly continuous temperature-dependent broadband spectra of water. Moreover, we find that corresponding spectra for aqueous solutions reveal the same features as pure water. However, in contrast to the latter, crystallization in these solutions can be avoided by supercooling. As different spectral contributions tend to disentangle at low temperatures, this enables us to deconvolute them when approaching the glass transition under cooling. We find that the overall spectral development, including the 20 GHz feature (employed for microwave heating), closely resembles the behavior known for common supercooled liquids. Thus water's absorption of electromagnetic waves at room temperature is not unusual but very similar to that of glass-forming liquids at elevated temperatures, deep in the low-viscosity liquid regime, and should be interpreted along similar lines.

  2. Scattering theory of stochastic electromagnetic light waves.

    Science.gov (United States)

    Wang, Tao; Zhao, Daomu

    2010-07-15

    We generalize scattering theory to stochastic electromagnetic light waves. It is shown that when a stochastic electromagnetic light wave is scattered from a medium, the properties of the scattered field can be characterized by a 3 x 3 cross-spectral density matrix. An example of scattering of a spatially coherent electromagnetic light wave from a deterministic medium is discussed. Some interesting phenomena emerge, including the changes of the spectral degree of coherence and of the spectral degree of polarization of the scattered field.

  3. Electromagnetic wave analogue of electronic diode

    OpenAIRE

    Shadrivov, Ilya V.; Powell, David A.; Kivshar, Yuri S.; Fedotov, Vassili A.; Zheludev, Nikolay I.

    2010-01-01

    An electronic diode is a nonlinear semiconductor circuit component that allows conduction of electrical current in one direction only. A component with similar functionality for electromagnetic waves, an electromagnetic isolator, is based on the Faraday effect of the polarization state rotation and is also a key component of optical and microwave systems. Here we demonstrate a chiral electromagnetic diode, which is a direct analogue of an electronic diode: its functionality is underpinned by ...

  4. Coupled seismic and electromagnetic wave propagation

    NARCIS (Netherlands)

    Schakel, M.D.

    2011-01-01

    Coupled seismic and electromagnetic wave propagation is studied theoretically and experimentally. This coupling arises because of the electrochemical double layer, which exists along the solid-grain/fluid-electrolyte boundaries of porous media. Within the double layer, charge is redistributed,

  5. Scattering of electromagnetic waves by obstacles

    CERN Document Server

    Kristensson, Gerhard

    2016-01-01

    The main purpose of Scattering of Electromagnetic Waves by Obstacles is to give a theoretical treatment of the scattering phenomena, and to illustrate numerical computations of some canonical scattering problems for different geometries and materials.

  6. ORDNANCE CORPS VIEWS ELECTROMAGNETIC RADIATION HAZARDS TO WEAPONS SYSTEMS,

    Science.gov (United States)

    EXPLOSIVES INITIATORS, * ELECTROMAGNETIC RADIATION ), HAZARDS, ELECTROMAGNETIC SHIELDING, RADIOFREQUENCY POWER, ANTENNAS, ATTENUATORS, IMPEDANCE MATCHING, SENSITIVITY, WEAPON SYSTEMS, MODULATION, CIRCUITS, BROADBAND

  7. Special inhomogeneous electromagnetic waves in hyperbolic metamaterials

    Science.gov (United States)

    Kurilkina, S. N.; Petrov, N. S.; Zimin, A. B.; Belyi, V. N.

    2017-12-01

    Herein, it is shown that under conditions of total internal reflection of plane homogeneous electromagnetic waves at the interface of a hyperbolic metamaterial (HMM) and an ordinary isotropic medium, special inhomogeneous electromagnetic waves are excited in certain circumstances near the surface of the metamaterial and their amplitude changes with distance according to the non-exponential law. The existence conditions for such waves are established for the case when the optical axis is located within the interface plane and forms an angle with the plane of incidence. The energy flux and density of energy of special inhomogeneous waves in a HMM are determined.

  8. Method and apparatus for measuring electromagnetic radiation

    Science.gov (United States)

    Been, J. F. (Inventor)

    1973-01-01

    An apparatus and method are described in which the capacitance of a semiconductor junction subjected to an electromagnetic radiation field is utilized to indicate the intensity or strength of the radiation.

  9. [Mechanisms of electromagnetic radiation damaging male reproduction].

    Science.gov (United States)

    Xue, Lei; Chen, Hao-Yu; Wang, Shui-Ming

    2012-08-01

    More and more evidence from over 50 years of researches on the effects of electromagnetic radiation on male reproduction show that a certain dose of electromagnetic radiation obviously damages male reproduction, particularly the structure and function of spermatogenic cells. The mechanisms of the injury may be associated with energy dysmetabolism, lipid peroxidation, abnormal expressions of apoptosis-related genes and proteins, and DNA damage.

  10. Leaky surface electromagnetic waves on a high-index dielectric grating.

    Science.gov (United States)

    Maradudin, A A; Simonsen, I; Zierau, W

    2016-05-15

    We show theoretically that the periodically corrugated surface of a high-index dielectric medium can support a leaky surface electromagnetic wave. This wave is bound to the surface in the vacuum, but radiates into the dielectric. Despite this radiative damping, the surface wave can have a long lifetime.

  11. Relativistic particle motion in nonuniform electromagnetic waves

    Science.gov (United States)

    Schmidt, G.; Wilcox, T.

    1973-01-01

    It is shown that a charged particle moving in a strong nonuniform electromagnetic wave suffers a net acceleration in the direction of the negative intensity gradient of the wave. Electrons will be expelled perpendicularly from narrow laser beams and various instabilities can result.

  12. Terrestrial propagation of long electromagnetic waves

    CERN Document Server

    Galejs, Janis; Fock, V A

    2013-01-01

    Terrestrial Propagation of Long Electromagnetic Waves deals with the propagation of long electromagnetic waves confined principally to the shell between the earth and the ionosphere, known as the terrestrial waveguide. The discussion is limited to steady-state solutions in a waveguide that is uniform in the direction of propagation. Wave propagation is characterized almost exclusively by mode theory. The mathematics are developed only for sources at the ground surface or within the waveguide, including artificial sources as well as lightning discharges. This volume is comprised of nine chapte

  13. Electromagnetic radiation and nonlinear energy flow in an electron beam-plasma system

    Science.gov (United States)

    Whelan, D. A.; Stenzel, R. L.

    1985-01-01

    It is shown that the unstable electron-plasma waves of a beam-plasma system can generate electromagnetic radiation in a uniform plasma. The generation mechanism is a scattering of the unstable electron plasma waves off ion-acoustic waves, producing electromagnetic waves whose frequency is near the local plasma frequency. The wave vector and frequency matching conditions of the three-wave mode coupling are experimentally verified. The electromagnetic radiation is observed to be polarized with the electric field parallel to the beam direction, and its source region is shown to be localized to the unstable plasma wave region. The frequency spectrum shows negligible intensity near the second harmonic of the plasma frequency. These results suggest that the observed electromagnetic radiation of type III solar bursts may be generated near the local plasma frequency and observed downstream where the wave frequency is near the harmonic of the plasma frequency.

  14. Interaction of the electromagnetic precursor from a relativistic shock with the upstream flow - I. Synchrotron absorption of strong electromagnetic waves

    Science.gov (United States)

    Lyubarsky, Yuri

    2018-02-01

    This paper is the first in the series of papers aiming to study interaction of the electromagnetic precursor waves generated at the front of a relativistic shock with the upstream flow. It is motivated by a simple consideration showing that the absorption of such an electromagnetic precursor could yield an efficient transformation of the kinetic energy of the upstream flow to the energy of accelerated particles. Taking into account that the precursor is a strong wave, in which electrons oscillate with relativistic velocities, the standard plasma-radiation interaction processes should be reconsidered. In this paper, I calculate the synchrotron absorption of strong electromagnetic waves.

  15. Influence of gravitation on the propagation of electromagnetic radiation

    Science.gov (United States)

    Mashhoon, B.

    1975-01-01

    The existence of a general helicity-rotation coupling is demonstrated for electromagnetic waves propagating in the field of a slowly rotating body and in the Goedel universe. This coupling leads to differential focusing of circularly polarized radiation by a gravitational field which is detectable for a rapidly rotating collapsed body. The electromagnetic perturbations and their frequency spectrum are given for the Goedel universe. The spectrum of frequencies is bounded from below by the characteristic rotation frequency of the Goedel universe. If the universe were rotating, the differential focusing effect would be extremely small due to the present upper limit on the anisotropy of the microwave background radiation.

  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. Fundamentals of electromagnetics 2 quasistatics and waves

    CERN Document Server

    Voltmer, David

    2007-01-01

    This book is the second of two volumes which have been created to provide an understanding of the basic principles and applications of electromagnetic fields for electrical engineering students. Fundamentals of Electromagnetics Vol 2: Quasistatics and Waves examines how the low-frequency models of lumped elements are modified to include parasitic elements. For even higher frequencies, wave behavior in space and on transmission lines is explained. Finally, the textbook concludes with details of transmission line properties and applications. Upon completion of this book and its companion Fundame

  18. Electromagnetic radiation from a laser wakefield accelerator

    NARCIS (Netherlands)

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

    2008-01-01

    Coherent and incoherent electromagnetic radiation emitted from a laser wakefield accelerator is calculated based on Lienard-Wiechert potentials. It is found that at wavelengths longer than the bunch length, the radiation is coherent. The coherent radiation, which typically lies in the infrared

  19. Electromagnetic Radiation from QCD Matter: Theory Overview

    OpenAIRE

    Shen, Chun

    2016-01-01

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

  20. Detection of electromagnetic radiation using nonlinear materials

    Science.gov (United States)

    Hwang, Harold Y.; Liu, Mengkun; Averitt, Richard D.; Nelson, Keith A.; Sternbach, Aaron; Fan, Kebin

    2016-06-14

    An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

  1. Electron beam injection during active experiments. I - Electromagnetic wave emissions

    Science.gov (United States)

    Winglee, R. M.; Kellogg, P. J.

    1990-01-01

    The wave emissions produced in Echo 7 experiment by active injections of electron beams were investigated to determine the properties of the electromagnetic and electrostatic fields for both the field-aligned and cross-field injection in such experiments and to evaluate the sources of free energy and relative efficiencies for the generation of the VLF and HF emissions. It is shown that, for typical beam energies in active experiments, electromagnetic effects do not substantially change the bulk properties of the beam, spacecraft charging, and plasma particle acceleration. Through simulations, beam-generated whistlers; fundamental z-mode and harmonic x-mode radiation; and electrostatic electron-cyclotron, upper-hybrid, Langmuir, and lower-hybrid waves were identified. The characteristics of the observed wave spectra were found to be sensitive to both the ratio of the electron plasma frequency to the cyclotron frequency and the angle of injection relative to the magnetic field.

  2. BIOLOGICAL EFFECTS OF HIGH-FREQUENCY ELECTROMAGNETIC WAVES

    Science.gov (United States)

    In this report the author discusses the influence of high-frequency electromagnetic waves on living matter, especially in the field of microwaves. He...of electromagnetic waves . Symptoms of damage are listed and methods of protection discussed.

  3. Electromagnetic wave propagations in conjugate metamaterials.

    Science.gov (United States)

    Xu, Yadong; Fu, Yangyang; Chen, Huanyang

    2017-03-06

    In this work, by employing field transformation optics, we deduce a special kind of materials called conjugate metamaterials, which can support intriguing electromagnetic wave propagations, such as negative refractions and lasing phenomena. These materials could also serve as substrates for making a subwavelength-resolution lens, and the so-called "perfect lens" is demonstrated to be a limiting case.

  4. Vector plane wave spectrum of an arbitrary polarized electromagnetic wave.

    Science.gov (United States)

    Guo, Hanming; Chen, Jiabi; Zhuang, Songlin

    2006-03-20

    By using the method of modal expansions of the independent transverse fields, a formula of vector plane wave spectrum (VPWS) of an arbitrary polarized electromagnetic wave in a homogenous medium is derived. In this formula VPWS is composed of TM- and TE-mode plane wave spectrum, where the amplitude and unit polarized direction of every plane wave are separable, which has more obviously physical meaning and is more convenient to apply in some cases compared to previous formula of VPWS. As an example, the formula of VPWS is applied to the well-known radially and azimuthally polarized beam. In addition, vector Fourier-Bessel transform pairs of an arbitrary polarized electromagnetic wave with circular symmetry are also derived.

  5. Phase Transition in the Process of Formation of Electromagnetic Radiation

    Science.gov (United States)

    Yakubov, V. P.; Vaiman, E. V.; Prasath, A.

    2017-04-01

    A new look at the description of the phenomenon of electromagnetic wave radiation as a phase transition of a quasi-static field state (near zone) in the field of running wave (far zone) is suggested. It is demonstrated that the boundary of this transition, called the causal surface, is sufficiently localized. The position of the causal surface depends on the chosen radiation frequency. The skin layer in media with strong absorption is formed at the boundary of the causal surface, and this can be used for depth sensing of such media.

  6. Principles of electromagnetic waves in metasurfaces

    Science.gov (United States)

    Luo, XianGang

    2015-09-01

    Metasurfaces are artificially structured thin films with unusual properties on demand. Different from metamaterials, the metasurfaces change the electromagnetic waves mainly by exploiting the boundary conditions, rather than the constitutive parameters in three dimensional (3D) spaces. Despite the intrinsic similarities in the operational principles of metasurfaces, there is not a universal theory available for the understanding and design of these devices. In this article, we propose the concept of metasurface waves (M-waves) and provide a general theory to describe the principles of such waves. Most importantly, it is shown that the M-waves share some fundamental properties such as extremely short wavelength, abrupt phase change and strong chromatic dispersion, which making them different from traditional bulk waves. We show that these properties can enable many important applications such as subwavelength imaging and lithography, planar optical devices, broadband anti-reflection, absorption and polarization conversion. Our results demonstrated unambiguously that traditional laws of diffraction, refraction, reflection and absorption can be overcome by using the novel properties of M-waves. The theory provided here may pave the way for the design of new electromagnetic devices and further improvement of metasurfaces.

  7. Excitation of surface electromagnetic waves on water.

    Science.gov (United States)

    Singh, A K; Goben, C A; Davarpanah, M; Boone, J L

    1978-11-01

    Excitation of surface electromagnetic waves (SEW) on water was studied using optical coupling techniques at microwave frequencies. Excitation of SEW was also achieved using direct horn antenna coupling. The transmitted SEW power was increased by adding acid and salt to water. The horn antenna gave the maximum excitation efficiency 70%. It was increased to 75% by collimating the electromagnetic beam in the vertical direction. Excitation efficiency for the prism (0 degrees pitch angle) and grating couplers were 15.2% and 10.5% respectively. By changing the prism coupler pitch angle to +36 degrees , its excitation efficiency was increased to 82%.

  8. Electromagnetic radiation under explicit symmetry breaking.

    Science.gov (United States)

    Sinha, Dhiraj; Amaratunga, Gehan A J

    2015-04-10

    We report our observation that radiation from a system of accelerating charges is possible only when there is explicit breaking of symmetry in the electric field in space within the spatial configuration of the radiating system. Under symmetry breaking, current within an enclosed area around the radiating structure is not conserved at a certain instant of time resulting in radiation in free space. Electromagnetic radiation from dielectric and piezoelectric material based resonators are discussed in this context. Finally, it is argued that symmetry of a resonator of any form can be explicitly broken to create a radiating antenna.

  9. Electromagnetic radiations and cancer. Cause and prevention.

    Science.gov (United States)

    Shore, R E

    1988-10-15

    The various types of electromagnetic radiation differ considerably in their ability to induce cancer. The potential of radiofrequency or microwave radiation and low-frequency electromagnetic radiation to alter DNA is very limited, because their energy is too low to produce substantial ionizations. They are therefore unlikely to be carcinogenic by any direct mechanism. Epidemiologic studies of the carcinogenicity of microwave radiation are basically negative. Studies of workers with relatively high exposures to low-frequency electromagnetic fields have suggested that such persons may be at somewhat elevated risk for leukemia, especially of the acute myeloid type, but the studies have had methodologic weaknesses and mixed results. The association is not proven at this point, but neither can it be ruled out. For ionizing radiation, which is clearly carcinogenic, major questions pertain to how to define the magnitude of risk from low doses and low dose rates, how to identify subgroups of people who are especially susceptible to the effects of ionizing radiation, and how to minimize radiation exposure. When fortuitous radiation exposure from manmade sources, such as radioactive releases from nuclear power plants, are examined in the context of the total exposure people receive from natural sources, medical irradiation, etc., they are almost always found to be small by comparison. Quantitatively, two sources of radiation provide the greatest opportunities for exposure reduction: abatement of radon levels in homes, and reduction in medical radiation exposures.

  10. Division of the momentum of electromagnetic waves in linear media into electromagnetic and material parts.

    Science.gov (United States)

    Saldanha, Pablo L

    2010-02-01

    It is proposed a natural and consistent division of the momentum of electromagnetic waves in linear, non-dispersive and non-absorptive dielectric and magnetic media into material and electromagnetic parts. The material part is calculated using directly the Lorentz force law and the electromagnetic momentum density has the form epsilon(0)E x B, without an explicit dependence on the properties of the media. The consistency of the treatment is verified through the obtention of a correct momentum balance equation in many examples and showing the compatibility of the division with the Einstein's theory of relativity by the use of a gedanken experiment. An experimental prediction for the radiation pressure on mirrors immersed in linear dielectric and magnetic media is also made.

  11. Electromagnetic Radiation Generated by Acoustic Excitation of Rock Samples

    Science.gov (United States)

    Yavorovich, Lyudmila V.; Bespalko, Anatolii A.; Fedotov, Pavel I.; Baksht, Rina B.

    2016-10-01

    The paper presents an experiment on acoustic excitation of electromagnetic radiation (EMR) signals in skarn, sandstone, and magnetite ore samples. For the skarn and sandstone samples, the EMR signal amplitude was observed to decrease with increasing ultimate strength. Supposedly, this effect can be explained by assuming that EMR is generated when an acoustic wave propagates through an electrical double layer. The presence of piezoelectric inclusions ( e.g., quartz) in the magnetite ore enhances the analog EMR signal and its spectral components.

  12. [Experimental research on the electromagnetic radiation immunity of a kind of portable monitor].

    Science.gov (United States)

    Yuan, Jun; Xiao, Dongping; Jian, Xin

    2010-11-01

    The paper is focused on a kind of portable monitor that is widely used in military hospitals. In order to study the electromagnetic radiation immunity of the monitor, the experiments of electromagnetic radiation caused by radio frequency continuous wave in reverberation chamber and by ultra wide band (UWB) electromagnetic pulse have been done. The study results show that UWB electromagnetic pulse interferes observably the operating state of the monitor. It should be paid high attention to take protective measures. The monitor tested has some electromagnetic immunity ability for radio frequency continuous wave radiation. The frequent abnormal phenomena are baseline drift and waveform distortion. The electromagnetic sensitivity of the monitor is related to the frequency of interference source. The monitor tested is most sensitive to the frequency of 390 MHz.

  13. Landau levels for an electromagnetic wave

    Science.gov (United States)

    Zyuzin, Vladimir A.

    2017-10-01

    In this paper we show that the frequencies of propagating electromagnetic waves (photons) in a rotating dielectric medium obey Landau quantization. We show that the degeneracy of right and left helicities of photons is broken on the lowest Landau level. In homogeneous space this level is shown to be helical; i.e., left and right helical photons counterpropagate. This leads to a helical vortical effect for photons, which can be understood as an inverse of the optical torque.

  14. Electromagnetic Wave Interactions with a Metamaterial Cloak

    Science.gov (United States)

    Chen, Hongsheng; Wu, Bae-Ian; Zhang, Baile; Kong, Jin Au

    2007-08-01

    We establish analytically the interactions of electromagnetic wave with a general class of spherical cloaks based on a full wave Mie scattering model. We show that for an ideal cloak the total scattering cross section is absolutely zero, but for a cloak with a specific type of loss, only the backscattering is exactly zero, which indicates the cloak can still be rendered invisible with a monostatic (transmitter and receiver in the same location) detection. Furthermore, we show that for a cloak with imperfect parameters the bistatic (transmitter and receiver in different locations) scattering performance is more sensitive to ηt=μt/γt than nt=μtγt.

  15. Electromagnetic Radiation of Electrons in Periodic Structures

    CERN Document Server

    Potylitsyn, Alexander Petrovich

    2011-01-01

    Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...

  16. Low frequency electromagnetic radiation and hearing.

    Science.gov (United States)

    Morales, J; Garcia, M; Perez, C; Valverde, J V; Lopez-Sanchez, C; Garcia-Martinez, V; Quesada, J L

    2009-11-01

    To analyse the possible impact of low and extremely low frequency electromagnetic fields on the outer hairs cells of the organ of Corti, in a guinea pig model. Electromagnetic fields of 50, 500, 1000, 2000, 4000 and 5000 Hz frequencies and 1.5 microT intensity were generated using a transverse electromagnetic wave guide. Guinea pigs of both sexes, weighing 100-150 g, were used, with no abnormalities on general and otic examination. Total exposure times were: 360 hours for 50, 500 and 1000 Hz; 3300 hours for 2000 Hz; 4820 hours for 4000 Hz; and 6420 hours for 5000 Hz. One control animal was used in each frequency group. The parameters measured by electric response audiometer included: hearing level; waves I-IV latencies; wave I-III interpeak latency; and percentage appearance of waves I-III at 90 and 50 dB sound pressure level intensity. Values for the above parameters did not differ significantly, comparing the control animal and the rest of each group. In addition, no significant differences were found between our findings and those of previous studies of normal guinea pigs. Prolonged exposure to electromagnetic fields of 50 Hz to 5 KHz frequencies and 1.5 microT intensity, produced no functional or morphological alteration in the outer hair cells of the guinea pig organ of Corti.

  17. Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation

    Directory of Open Access Journals (Sweden)

    Luisa Nascimento Medeiros

    2016-02-01

    Full Text Available ABSTRACT INTRODUCTION: Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR. Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. OBJECTIVE: The aim of this study was to evaluate the available evidence about the possible causal association between tinnitus and exposure to electromagnetic waves. METHODS: A literature review was performed searching for the following keywords: tinnitus, electromagnetic field, mobile phones, radio frequency, and electromagnetic hypersensitivity. We selected 165 articles that were considered clinically relevant in at least one of the subjects. RESULTS: EMRFR can penetrate exposed tissues and safety exposure levels have been established. These waves provoke proved thermogenic effects and potential biological and genotoxic effects. Some individuals are more sensitive to electromagnetic exposure (electrosensitivity, and thus, present earlier symptoms. There may be a common pathophysiology between this electrosensitivity and tinnitus. CONCLUSION: There are already reasonable evidences to suggest caution for using mobile phones to prevent auditory damage and the onset or worsening of tinnitus.

  18. Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation.

    Science.gov (United States)

    Medeiros, Luisa Nascimento; Sanchez, Tanit Ganz

    2016-01-01

    Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR). Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. The aim of this study was to evaluate the available evidence about the possible causal association between tinnitus and exposure to electromagnetic waves. A literature review was performed searching for the following keywords: tinnitus, electromagnetic field, mobile phones, radio frequency, and electromagnetic hypersensitivity. We selected 165 articles that were considered clinically relevant in at least one of the subjects. EMRFR can penetrate exposed tissues and safety exposure levels have been established. These waves provoke proved thermogenic effects and potential biological and genotoxic effects. Some individuals are more sensitive to electromagnetic exposure (electrosensitivity), and thus, present earlier symptoms. There may be a common pathophysiology between this electrosensitivity and tinnitus. There are already reasonable evidences to suggest caution for using mobile phones to prevent auditory damage and the onset or worsening of tinnitus. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  19. 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

  20. Superluminal localized structures of electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rozanov, Nikolai N [Research Institute for Laser Physics, St. Petersburg (Russian Federation)

    2005-02-28

    This paper analyzes localized invariable-form structures of electromagnetic radiation in vacuum and soliton-like light structures traveling superluminally in a nonlinear medium. Both types of structures are concluded to be unstable to small perturbations. (annus mirabilis. methodological notes)

  1. Foldable Frame Supporting Electromagnetic Radiation Collectors

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to flexible frames supporting electromagnetic radiation collectors, such as antennas, antenna reflectors, deflectors or solar collectors, for celestial or terrestrial applications, which can be folded to be stored and/or transported. The method for stowing deforms...

  2. Stochastic electromagnetic radiation of complex sources

    NARCIS (Netherlands)

    Naus, H.W.L.

    2007-01-01

    The emission of electromagnetic radiation by localized complex electric charge and current distributions is studied. A statistical formalism in terms of general dynamical multipole fields is developed. The appearing coefficients are treated as stochastic variables. Hereby as much as possible a

  3. Asymmetric Ultrasonic Pulse Radiation Using Electromagnetic-Induction Transducer and PZT(Pb(Zr-Ti)O3) Transducer with Wave Synthesis Method

    Science.gov (United States)

    Endoh, Nobuyuki; Yamamoto, Koji

    1993-05-01

    In medical applications, especially in urology, we use a fragmentation calculus technique with shock waves. This technique is very profitable because of no abdominal surgery for a human being. Large negative sound amplitude pulses, however, can cause problems such as internal hemorrhage or pain in the human body. The final goal of this study is to develop a means to project an intense positive unipolar pulse without negative sound pressure. We improved a composite transducer consisting of an electromagnetic-induction-type (EMI) transducer and PZT (Pb(Zr-Ti)O3) transducers. An EMI transducer consisting of a metal coil and vibration membrane can project intense sound pulses into water. In order to suppress its negative sound pressure, we project a compensation pulse with PZT transducers using an inverse filtering method. An asymmetric pulse whose P+ to P- amplitude ratio was very high was projected in water.

  4. Simple dynamic electromagnetic radiation detector

    Science.gov (United States)

    Been, J. F.

    1972-01-01

    Detector monitors gamma dose rate at particular position in a radiation facility where a mixed neutron-gamma environment exists, thus determining reactor power level changes. Device also maps gamma intensity profile across a neutron-gamma beam.

  5. Electricity generation using electromagnetic radiation

    Science.gov (United States)

    Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

    2017-08-22

    In general, in one aspect, the invention relates to a system to create vapor for generating electric power. The system includes a vessel comprising a fluid and a complex and a turbine. The vessel of the system is configured to concentrate EM radiation received from an EM radiation source. The vessel of the system is further configured to apply the EM radiation to the complex, where the complex absorbs the EM radiation to generate heat. The vessel of the system is also configured to transform, using the heat generated by the complex, the fluid to vapor. The vessel of the system is further configured to sending the vapor to a turbine. The turbine of the system is configured to receive, from the vessel, the vapor used to generate the electric power.

  6. Surface-plasmon-assisted electromagnetic wave propagation.

    Science.gov (United States)

    Yang, Wenbo; Reed, Jennifer M; Wang, Haining; Zou, Shengli

    2010-10-21

    Using electrodynamics tools, we investigated the effect of surface plasmons on the propagation direction of electromagnetic waves around a spherical silver nanoparticle and nano-structured silver film. The studies showed that the calculated effective index of refraction of a spherical silver nanoparticle from the Kramers-Kronig transformation method may not represent the index of refraction of the system but is consistent with the Poynting vector (the energy flow) direction at the microscopic scale. Using a silver film composed of periodic triangular prisms, we numerically demonstrated that electromagnetic waves may propagate along different directions depending on the incident polarization direction. When the incident polarization is in the plane of incidence and the surface plasmons are excited, the refracted light ray propagates along the same side of the surface normal as the incident wave. When the incident polarization is perpendicular to the plane of incidence, the refracted light ray always propagates on the opposite side of the surface normal. The results show that a silver film composed of periodic nano-sized triangular prisms may be used as a filter to simultaneously generate two polarized light rays of orthogonal polarizations from one light source.

  7. Shaping 3D Path of Electromagnetic Waves Using Gradient-Refractive-Index Metamaterials.

    Science.gov (United States)

    Jiang, Wei Xiang; Ge, Shuo; Han, Tiancheng; Zhang, Shuang; Mehmood, Muhammad Qasim; Qiu, Cheng-Wei; Cui, Tie Jun

    2016-08-01

    An all-dielectric semispherical lens with functions in shaping 3D wave-propagation paths is proposed and experimentally verified. When radiation sources are placed in the central region, the lens behaves as a magnifying device to resolve the sources in subwavelength scale; while when the electromagnetic waves impinge on the semispherical lens from outside, they will be guided spirally inward.

  8. Do electromagnetic waves always propagate along null geodesics?

    CERN Document Server

    Asenjo, Felipe A

    2016-01-01

    We find exact solutions to Maxwell equations written in terms of four-vector potentials in non--rotating, as well as in G\\"odel and Kerr spacetimes. Exact electromagnetic waves solutions are written on given gravitational field backgrounds where they evolve. We find that in non--rotating spherical symmetric spacetimes, electromagnetic plane waves travel along null geodesics. However, electromagnetic plane waves on G\\"odel and Kerr spacetimes do not exhibit that behavior.

  9. [The effect of electromagnetic waves of very high frequency of molecular spectra of radiation and absorption of nitric oxide on the functional activity of platelets].

    Science.gov (United States)

    Kirichuk, V F; Maĭborodin, A V; Volin, M V; Krenitskiĭ, A P; Tupikin, V D

    2001-01-01

    A study was made of the effect of electromagnetic EMI MMD-fluctuation on the frequencies of molecular spectra of radiation, and nitric oxide absorption under in vitro conditions on the functional activity of platelets in patients with unstable angina pectoris, with the help of a specially created generator. At amplitude-modulated and continuous modes of EMI MMD-irradiation of platelet-rich plasma for 5, 15 and 30 min the platelet functional activity decreases, which was shown up in reduction of their activation and fall of aggregative ability. The degree, to which platelet functional activity was inhibited, depended on the mode of irradiation and on duration of EMI MMD effect. The most obvious changes in platelet activation and in their readiness to aggregative response were observed at a continuous mode of irradiation within a 15 min interval.

  10. Role of surface electromagnetic waves in metamaterial absorbers.

    Science.gov (United States)

    Chen, Wen-Chen; Cardin, Andrew; Koirala, Machhindra; Liu, Xianliang; Tyler, Talmage; West, Kevin G; Bingham, Christopher M; Starr, Tatiana; Starr, Anthony F; Jokerst, Nan M; Padilla, Willie J

    2016-03-21

    Metamaterial absorbers have been demonstrated across much of the electromagnetic spectrum and exhibit both broad and narrow-band absorption for normally incident radiation. Absorption diminishes for increasing angles of incidence and transverse electric polarization falls off much more rapidly than transverse magnetic. We unambiguously demonstrate that broad-angle TM behavior cannot be associated with periodicity, but rather is due to coupling with a surface electromagnetic mode that is both supported by, and well described via the effective optical constants of the metamaterial where we achieve a resonant wavelength that is 19.1 times larger than the unit cell. Experimental results are supported by simulations and we highlight the potential to modify the angular response of absorbers by tailoring the surface wave.

  11. Electromagnetic Wave Propagation in Random Media

    DEFF Research Database (Denmark)

    Pécseli, Hans

    1984-01-01

    The propagation of a narrow frequency band beam of electromagnetic waves in a medium with randomly varying index of refraction is considered. A novel formulation of the governing equation is proposed. An equation for the average Green function (or transition probability) can then be derived....... A Fokker-Planck type equation is contained as a limiting case. The results are readily generalized to include the features of the random coupling model and it is argued that the present problem is particularly suited for an analysis of this type....

  12. Excitation of surface electromagnetic waves in a graphene-based Bragg grating.

    Science.gov (United States)

    Sreekanth, Kandammathe Valiyaveedu; Zeng, Shuwen; Shang, Jingzhi; Yong, Ken-Tye; Yu, Ting

    2012-01-01

    Here, we report the fabrication of a graphene-based Bragg grating (one-dimensional photonic crystal) and experimentally demonstrate the excitation of surface electromagnetic waves in the periodic structure using prism coupling technique. Surface electromagnetic waves are non-radiative electromagnetic modes that appear on the surface of semi-infinite 1D photonic crystal. In order to fabricate the graphene-based Bragg grating, alternating layers of high (graphene) and low (PMMA) refractive index materials have been used. The reflectivity plot shows a deepest, narrow dip after total internal reflection angle corresponds to the surface electromagnetic mode propagating at the Bragg grating/air boundary. The proposed graphene based Bragg grating can find a variety of potential surface electromagnetic wave applications such as sensors, fluorescence emission enhancement, modulators, etc.

  13. Simulation study of localization of electromagnetic waves in two-dimensional random dipolar systems.

    Science.gov (United States)

    Wang, Ken Kang-Hsin; Ye, Zhen

    2003-12-01

    We study the propagation and scattering of electromagnetic waves by random arrays of dipolar cylinders in a uniform medium. A set of self-consistent equations, incorporating all orders of multiple scattering of the electromagnetic waves, is derived from first principles and then solved numerically for electromagnetic fields. For certain ranges of frequencies, spatially localized electromagnetic waves appear in such a simple but realistic disordered system. Dependence of localization on the frequency, radiation damping, and filling factor is shown. The spatial behavior of the total, coherent, and diffusive waves is explored in detail, and found to comply with a physical intuitive picture. A phase diagram characterizing localization is presented, in agreement with previous investigations on other systems.

  14. Electromagnetic radiation from linearly and nonlinearly oscillating charge drops

    Science.gov (United States)

    Grigor'ev, A. I.; Shiryaeva, S. O.

    2016-12-01

    It has been shown that analytic calculations of the intensity of electromagnetic radiation from an oscillating charged drop in the approximation linear in the oscillation amplitude (small parameter is on the order of 0.1) give only the quadrupole component of the total radiation. The dipole component can only be obtained in calculations using higher-order approximations. Nevertheless, the intensity of the dipole radiation turns out to be substantially higher (by 14-15 orders of magnitude). This is because the decomposition of radiation from a system of charges into multipole components (differing even in the rates of decrease in the potential with the distance) is carried out using the expansion in a substantially smaller parameter, viz., the ratio of the size of the emitting system (in our case, a drop of radius 10 μm) to the distance to the point of observation in the wave zone of the emission of radiation (emitted wavelength) of 100-1000 m. As a result, this second small parameter is on the order of 10-7 to 10-8. On the other hand, in accordance with the field theory, the ratio of intensities of quadrupole and dipole radiations is proportional to the squared ratio of the hydrodynamic velocity of the oscillating surface of a charged drop to the velocity of propagation of an electromagnetic signal in vacuum (velocity of light), which yields a ratio of 10-14 to 10-15.

  15. Does electromagnetic radiation accelerate galactic cosmic rays

    Science.gov (United States)

    Eichler, D.

    1977-01-01

    The 'reactor' theories of Tsytovich and collaborators (1973) of cosmic-ray acceleration by electromagnetic radiation are examined in the context of galactic cosmic rays. It is shown that any isotropic synchrotron or Compton reactors with reasonable astrophysical parameters can yield particles with a maximum relativistic factor of only about 10,000. If they are to produce particles with higher relativistic factors, the losses due to inverse Compton scattering of the electromagnetic radiation in them outweigh the acceleration, and this violates the assumptions of the theory. This is a critical restriction in the context of galactic cosmic rays, which have a power-law spectrum extending up to a relativistic factor of 1 million.

  16. Electromagnetic radiation absorbers and modulators comprising polyaniline

    Science.gov (United States)

    Epstein, Arthur J.; Ginder, John M.; Roe, Mitchell G.; Hajiseyedjavadi, Hamid

    1992-01-01

    A composition for absorbing electromagnetic radiation, wherein said electromagnetic radiation possesses a wavelength generally in the range of from about 1000 Angstroms to about 50 meters, wherein said composition comprises a polyaniline composition of the formula ##STR1## where y can be equal to or greater than zero, and R.sup.1 and R.sup.2 are independently selected from the group containing of H, --OCH.sub.3, --CH.sub.3, --F, --Cl, --Br, --I, NR.sup.3 .sub.2, --NHCOR.sup.3, --OH, --O.sup.-, SR.sup.3, --OCOR.sup.3, --NO.sub.2, --COOH, --COOR.sup.3, --COR.sup.3, --CHO, and --CN, where R.sup.3 is a C.sub.1 to C.sub.8 alkyl, aryl or aralkyl group.

  17. Complex space source theory of spatially localized electromagnetic waves

    CERN Document Server

    Seshadri, SR

    2013-01-01

    The author highlights that there is a need obtain exact full-wave solutions that reduce to the paraxial beams in the appropriate limit. Complex Space Source Theory of Spatially Localized Electromagnetic Waves treats the exact full-wave generalizations of all the basic types of paraxial beam solutions. These are developed by the use of Fourier and Bessel transform techniques and the complex space source theory of spatially localized electromagnetic waves is integrated as a branch of Fourier optics.

  18. Shaping electromagnetic waves using software-automatically-designed metasurfaces.

    Science.gov (United States)

    Zhang, Qian; Wan, Xiang; Liu, Shuo; Yuan Yin, Jia; Zhang, Lei; Jun Cui, Tie

    2017-06-15

    We present a fully digital procedure of designing reflective coding metasurfaces to shape reflected electromagnetic waves. The design procedure is completely automatic, controlled by a personal computer. In details, the macro coding units of metasurface are automatically divided into several types (e.g. two types for 1-bit coding, four types for 2-bit coding, etc.), and each type of the macro coding units is formed by discretely random arrangement of micro coding units. By combining an optimization algorithm and commercial electromagnetic software, the digital patterns of the macro coding units are optimized to possess constant phase difference for the reflected waves. The apertures of the designed reflective metasurfaces are formed by arranging the macro coding units with certain coding sequence. To experimentally verify the performance, a coding metasurface is fabricated by automatically designing two digital 1-bit unit cells, which are arranged in array to constitute a periodic coding metasurface to generate the required four-beam radiations with specific directions. Two complicated functional metasurfaces with circularly- and elliptically-shaped radiation beams are realized by automatically designing 4-bit macro coding units, showing excellent performance of the automatic designs by software. The proposed method provides a smart tool to realize various functional devices and systems automatically.

  19. 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.

  20. Electromagnetic radiation generated by arcing in low density plasma

    Science.gov (United States)

    Vayner, Boris V.; Ferguson, Dale C.; Snyder, David B.; Doreswamy, C. V.

    1996-01-01

    An unavoidable step in the process of space exploration is to use high-power, very large spacecraft launched into Earth orbit. Obviously, the spacecraft will need powerful energy sources. Previous experience has shown that electrical discharges occur on the surfaces of a high-voltage array, and these discharges (arcs) are undesirable in many respects. Moreover, any high voltage conductor will interact with the surrounding plasma, and that interaction may result in electrical discharges between the conductor and plasma (or between two conductors with different potentials, for example, during docking and extravehicular activity). One very important aspect is the generation of electromagnetic radiation by arcing. To prevent the negative influence of electromagnetic noise on the operation of spacecraft systems, it seems necessary to determine the spectra and absolute levels of the radiation, and to determine limitations on the solar array bias voltage that depend on the parameters of LEO plasma and the technical requirements of the spacecraft equipment. This report describes the results of an experimental study and computer simulation of the electromagnetic radiation generated by arcing on spacecraft surfaces. A large set of high quality data was obtained during the Solar Array Module Plasma Interaction Experiment (SAMPIE, flight STS-62) and ground test. These data include the amplitudes of current, pulse forms, duration of each arc, and spectra of plasma waves. A theoretical explanation of the observed features is presented in this report too. The elaborated model allows us to determine the parameters of the electromagnetic noise for different frequency ranges, distances from the arcing site, and distinct kinds of plasma waves.

  1. influence of electromagnetic waves produced by an amplitude ...

    African Journals Online (AJOL)

    PROF EKWUEME

    2. Theory. 2.1. Excess minority carriers' density. Polycrystalline back surface field silicon solar cell with n+-p-p+ structure is studied under monochromatic illumination and under electromagnetic waves (figure 1). Figure 1: Silicon solar cell illuminated by monochromatic light and under electromagnetic waves influence.

  2. Correction of stress-depended changes of glucoproteid platelet receptors activity by electromagnetic radiation of terahertz range

    Directory of Open Access Journals (Sweden)

    V.F. Kirichuk

    2010-09-01

    Full Text Available The research goal is correction of stress-depended changes of glucoproteid (Gp platelet receptors activity by electromagnetic radiation of terahertz range. Influence of electromagnetic waves of terahertz range at the frequency of molecular spectrum of radiation and absorption of nitrogen oxide on lectin-induced platelet aggregation of white rats in the stressed condition was investigated

  3. Investigation on possible risks to human health by exposure to the radiation of electromagnetic waves produced by the radio communications; Investigacion sobre posibles riesgos a la salud humana por exposicion a la radiacion de ondas electromagneticas producidas por las radiocomunicaciones

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Hernandez, Carlos Felipe; Ibarguengoytia Gonzalez, Pablo Hector; Flores Garcia, Andres; Franco Campos, Laura Elena [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2011-06-13

    This verification procedure is based on a research work on the possible risks to human health by exposure to the radiation of electromagnetic waves produced by the radio communications, cases of study: cellular telephony, radio digital troncalized and wireless telephony IP of Voice on IP (wireless local area network). The revision of all the international standards and the applicable national standardization was included, as well as the verification of fulfillment. [Spanish] Este procedimiento de verificacion esta basado en un trabajo de investigacion sobre posibles riesgos a la salud humana por exposicion a la radiacion de ondas electromagneticas producidas por la radiocomunicaciones, casos de estudio: telefonia celular, radio troncalizado digital y telefonia IP inalambrica de Voz sobre IP (red de area local inalambrica). Se incluyo la revision de todos los estandares internacionales y de la normatividad nacional aplicable, asi como la verificacion de cumplimiento.

  4. Scattering of an electromagnetic plane wave by a Luneburg lens. II. Wave theory.

    Science.gov (United States)

    Lock, James A

    2008-12-01

    The partial wave scattering and interior amplitudes for the interaction of an electromagnetic plane wave with a modified Luneburg lens are derived in terms of the exterior and interior radial functions of the scalar radiation potentials evaluated at the lens surface. A Debye series decomposition of these amplitudes is also performed and discussed. The effective potential inside the lens for the transverse electric polarization is qualitatively examined, and the approximate lens size parameters of morphology-dependent resonances are determined. Finally, the physical optics model is used to calculate wave scattering in the vicinity of the ray theory orbiting condition in order to demonstrate the smoothing of ray theory discontinuities by the diffraction of scattered waves.

  5. BATHYMETRIC SOUNDING by REMOTE SENSING Using ELECTROMAGNETIC RADIATION

    Directory of Open Access Journals (Sweden)

    Frank C Lin

    2016-11-01

    Full Text Available We describe a novel modus operandi to survey the ocean floor. We utilize the eruption of submarine volcanoes as a light source. The electromagnetic radiation emitted by such eruptions illuminate the ocean floor and thus provides information about the barythmetric topology, and a geostationary satellite can monitor this. Since the wavelength of the electromagnetic radiation is many orders of magnitude shorter than that of the acoustic wave, finer details of the bathymetric features can be obtained. We show that a topographical representation of the seabed can be derived from the Signal Diagram by a simple transformation (a mirror reflection. In this case the radiation is emitted by water molecules stimulated by the heat of the volcanic eruption, in contradistinction to the case of tsunami radiation, where the water molecules are stimulated by mutual collisions at high speed. We give two examples: Illapel, Chile and Chichi-shima, Japan. We have also shown that water molecules in the ocean, when stimulated by the heat of submarine volcanic eruption, will emit infrared radiation

  6. Bio-Soliton Model that predicts Non-Thermal Electromagnetic Radiation Frequency Bands, that either Stabilize or Destabilize Life Conditions

    CERN Document Server

    Geesink, J H

    2016-01-01

    Solitons, as self-reinforcing solitary waves, interact with complex biological phenomena such as cellular self-organisation. Soliton models are able to describe a spectrum of electromagnetism modalities that can be applied to understand the physical principles of biological effects in living cells, as caused by electromagnetic radiation. A bio-soliton model is proposed, that enables to predict which eigen-frequencies of non-thermal electromagnetic waves are life-sustaining and which are, in contrast, detrimental for living cells. The particular effects are exerted by a range of electromagnetic wave frequencies of one-tenth of a Hertz till Peta Hertz, that show a pattern of twelve bands, if positioned on an acoustic frequency scale. The model was substantiated by a meta-analysis of 240 published papers of biological radiation experiments, in which a spectrum of non-thermal electromagnetic waves were exposed to living cells and intact organisms. These data support the concept of coherent quantized electromagnet...

  7. Descriptive study of electromagnetic wave distribution for various seating positions: using digital textbooks.

    Science.gov (United States)

    Seomun, GyeongAe; Kim, YoungHwan; Lee, Jung-Ah; Jeong, KwangHoon; Park, Seon-A; Kim, Miran; Noh, Wonjung

    2014-04-01

    To better understand environmental electromagnetic wave exposure during the use of digital textbooks by elementary school students, we measured numeric values of the electromagnetic fields produced by tablet personal computers (TPCs). Specifically, we examined the distribution of the electromagnetic waves for various students' seating positions in an elementary school that uses digital textbooks. Electric and magnetic fields from TPCs were measured using the HI-3603 Visual Display Terminal/ Very Low Frequency (VDT/VLF) radiation measurement system. Electromagnetic field values from TPCs measured at a student's seat and at a teacher's computer were deemed not harmful to health. However, electromagnetic field values varied based on the distance between students, other electronic devices such as a desktop computers, and student posture while using a TPC. Based on these results, it is necessary to guide students to observe proper posture and to arrange seats at an appropriate distance in the classroom.

  8. Electromagnetic wave propagation in a random distribution of C{sub 60} molecules

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah, Iran and Department of Nano Sciences, Institute for Studies in Theoretical Physics and Mathematics (IPM), Tehran (Iran, Islamic Republic of)

    2014-10-15

    Propagation of electromagnetic waves in a random distribution of C{sub 60} molecules are investigated, within the framework of the classical electrodynamics. Electronic excitations over the each C{sub 60} molecule surface are modeled by a spherical layer of electron gas represented by two interacting fluids, which takes into account the different nature of the π and σ electrons. It is found that the present medium supports four modes of electromagnetic waves, where they can be divided into two groups: one group with shorter wavelength than the light waves of the same frequency and the other with longer wavelength than the free-space radiation.

  9. Energy balance in coherent electromagnetic radiation

    CERN Document Server

    Coisson, R

    1994-01-01

    Bunched charges, as in the 'free electron laser', radiate more energy than unbunched ones. For a better understanding of how the forces between particles determine the conservation of energy, we take the simple model of two charges within a wavelength of a sinusodoidal wave, and show that the relative phase of the particle's motion with respect to the wave is modified by the force between the two particles, and this explains the extra work done by the wave. The phase shift is proportional to the emitted field and depends on the retardation (particle distance divided by speed of light), and turns out to be independent of distance. (author)

  10. Effects of 900 MHz electromagnetic radiation on ultrastructure of rats’ hippocampal neural stem cells in vitro

    OpenAIRE

    Hai-shui LUO; Wei-hua CHU; Zi-bing WAN; Sheng-li HU; Rong HU; Nan WU; Bo HU; Hua FENG; Gang ZHU

    2012-01-01

    Objective To investigate the effect of 900MHz electromagnetic radiation on the ultrastructure of rat hippocampal neural stem cells (NSCs) in vitro in order to provide basic materials for studying the biological effects of electromagnetic wave on the central nervous system. Methods Rat NSCs were divided into sham group, Radi1 group and Radi2 group, and they were respectively exposed to 900 MHz electromagnetic wave at power density of 0, 1, and 3mW/cm2 in vitro. Cells in Radi1 group and Radi2 g...

  11. Switchable metamaterial reflector/absorber for different polarized electromagnetic waves

    OpenAIRE

    Zhu, Bo; Feng, Yijun; Zhao, Juming; Huang, Ci; Jiang, Tian

    2010-01-01

    We demonstrate a controllable electromagnetic wave reflector/absorber for different polarizations with metamaterial involving electromagnetic resonant structures coupled with diodes. Through biasing at different voltages to turn ON and OFF the diodes, we are able to switch the structure between nearly total reflection and total absorption of a particularly polarized incident wave. By arranging orthogonally orientated resonant cells, the metamaterial can react to different polarized waves by s...

  12. Search For Gravitational Waves Through the Electromagnetic Faraday Rotation

    OpenAIRE

    Halilsoy, Mustafa; Gürtuğ, Özay

    2006-01-01

    A method is given which renders indirect detection of strong gravitational waves possible. This is based on the reflection (collision) of a linearly polarized electromagnetic shock wave from (with) a cross polarized impulsive and shock gravitational waves in accordance with the general theory of relativity. This highly non-linear process induces a detectable Faraday rotation in the polarization vector of the electromagnetic field. The file in this item is the publisher version (published v...

  13. Chorus Wave Energy Budget Analysis in the Earth's Radiation Belts

    Science.gov (United States)

    Blancarte, J.; Agapitov, O. V.; Mozer, F.

    2016-12-01

    Whistler-mode chorus emissions are important electromagnetic waves in the Earth's magnetosphere, where they continuously scatter and accelerate electrons of the outer radiation belt, controlling radiation hazards to satellites and astronauts. Here, we present an analysis of Van Allen Probes electric and magnetic field VLF waveform data, evaluating the wave energy budget, and show that a significant fraction of the energy corresponds to very oblique waves. Such waves, with a generally much smaller (up to 10 times) magnetic power than parallel waves, typically have comparable or even larger total energy. Very oblique waves may turn out to be a crucial agent of energy redistribution in the Earth's radiation belts and also provide nonlinear effects due to wave-particle interaction through the Landau resonance due to the significant electric field component parallel to the background magnetic field.

  14. Electromagnetic radiation from a rapidly rotating magnetized star in orbit

    Science.gov (United States)

    Hacyan, Shahen

    2016-02-01

    A general formula for the electromagnetic energy radiated by a rapidly rotating magnetic dipole in arbitrary motion is obtained. For a pulsar orbiting in a binary system, it is shown that the electromagnetic radiation produced by the orbital motion is usually weaker than the gravitational radiation, but not entirely negligible for general relativistic corrections.

  15. Electromagnetic wave probing of Earth's environment

    Science.gov (United States)

    Kong, Jin AU

    1988-01-01

    Polarimetric radar backscattering from anisotropic Earth terrain such as snow-covered ice fields and vegetation fields with row structures provides a challenging modeling problem from the electromagnetic wave point of view. Earth terrain covers are modeled as random media characterized by different dielectric constants and correlation functions. A three-layer model will be used to simulate a vegetation field or a snow-covered ice field with the top layer being snow or leaves, the middle layer being ice of trunks, and the bottom layer being sea water or ground. The volume scattering effects of snow-covered sea ice are studied with a three-layer random medium model for microwave remote sensing. The strong fluctuation theory and the bilocal approximation are applied to calculate the effective permittivities for snow and sea ice. The wave scattering theory in conjunction with the distorted Born approximation is then used to compute bistatic coefficients and backscattering cross sections. Theoretical results are illustrated by matching experimental data for dry snow-covered thick first-year sea ice at Point Barrow. The results derived can also be applied to the passive remote sensing by calculating the emissivity from the bistatic scattering coefficients.

  16. Testing black hole candidates with electromagnetic radiation

    Science.gov (United States)

    Bambi, Cosimo

    2017-04-01

    Astrophysical black hole candidates are thought to be the Kerr black holes of general relativity, but there is not yet direct observational evidence that the spacetime geometry around these objects is described by the Kerr solution. The study of the properties of the electromagnetic radiation emitted by gas or stars orbiting these objects can potentially test the Kerr black hole hypothesis. This paper reviews the state of the art of this research field, describing the possible approaches to test the Kerr metric with current and future observational facilities and discussing current constraints.

  17. Analytic descriptions of cylindrical electromagnetic waves in a nonlinear medium.

    Science.gov (United States)

    Xiong, Hao; Si, Liu-Gang; Yang, Xiaoxue; Wu, Ying

    2015-06-15

    A simple but highly efficient approach for dealing with the problem of cylindrical electromagnetic waves propagation in a nonlinear medium is proposed based on an exact solution proposed recently. We derive an analytical explicit formula, which exhibiting rich interesting nonlinear effects, to describe the propagation of any amount of cylindrical electromagnetic waves in a nonlinear medium. The results obtained by using the present method are accurately concordant with the results of using traditional coupled-wave equations. As an example of application, we discuss how a third wave affects the sum- and difference-frequency generation of two waves propagation in the nonlinear medium.

  18. Analytic descriptions of cylindrical electromagnetic waves in a nonlinear medium

    Science.gov (United States)

    Xiong, Hao; Si, Liu-Gang; Yang, Xiaoxue; Wu, Ying

    2015-01-01

    A simple but highly efficient approach for dealing with the problem of cylindrical electromagnetic waves propagation in a nonlinear medium is proposed based on an exact solution proposed recently. We derive an analytical explicit formula, which exhibiting rich interesting nonlinear effects, to describe the propagation of any amount of cylindrical electromagnetic waves in a nonlinear medium. The results obtained by using the present method are accurately concordant with the results of using traditional coupled-wave equations. As an example of application, we discuss how a third wave affects the sum- and difference-frequency generation of two waves propagation in the nonlinear medium. PMID:26073066

  19. Do electromagnetic waves always propagate along null geodesics?

    Science.gov (United States)

    Asenjo, Felipe A.; Hojman, Sergio A.

    2017-10-01

    We find exact solutions to Maxwell equations written in terms of four-vector potentials in non-rotating, as well as in Gödel and Kerr spacetimes. We show that Maxwell equations can be reduced to two uncoupled second-order differential equations for combinations of the components of the four-vector potential. Exact electromagnetic waves solutions are written on given gravitational field backgrounds where they evolve. We find that in non-rotating spherical symmetric spacetimes, electromagnetic waves travel along null geodesics. However, electromagnetic waves on Gödel and Kerr spacetimes do not exhibit that behavior.

  20. PERCEPTION LEVEL EVALUATION OF RADIO ELECTRONIC MEANS TO A PULSE OF ELECTROMAGNETIC RADIATION

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The method for evaluating the perception level of electronic means to pulsed electromagnetic radiation is consid- ered in this article. The electromagnetic wave penetration mechanism towards the elements of electronic systems and the impact on them are determined by the intensity of the radiation field on the elements of electronic systems. The impact of electromagnetic radiation pulses to the electronic systems refers to physical and analytical parameters of the relationship between exposure to pulses of electromagnetic radiation and the sample parameters of electronic systems. A physical and mathematical model of evaluating the perception level of electronic means to pulsed electromagnetic radiation is given. The developed model was based on the physics of electronics means failure which represents the description of electro- magnetic, electric and thermal processes that lead to the degradation of the original structure of the apparatus elements. The conditions that lead to the total equation electronic systems functional destruction when exposed to electromagnetic radia- tion pulses are described. The internal characteristics of the component elements that respond to the damaging effects are considered. The ratio for the power failure is determined. A thermal breakdown temperature versus pulse duration of expo- sure at various power levels is obtained. The way of evaluation the reliability of electronic systems when exposed to pulses of electromagnetic radiation as a destructive factor is obtained.

  1. Electromagnetic shock wave in nonlinear vacuum: exact solution.

    Science.gov (United States)

    Kovachev, Lubomir M; Georgieva, Daniela A; Kovachev, Kamen L

    2012-10-01

    An analytical approach to the theory of electromagnetic waves in nonlinear vacuum is developed. The evolution of the pulse is governed by a system of nonlinear wave vector equations. An exact solution with its own angular momentum in the form of a shock wave is obtained.

  2. Large numbers hypothesis. II - Electromagnetic radiation

    Science.gov (United States)

    Adams, P. J.

    1983-01-01

    This paper develops the theory of electromagnetic radiation in the units covariant formalism incorporating Dirac's large numbers hypothesis (LNH). A direct field-to-particle technique is used to obtain the photon propagation equation which explicitly involves the photon replication rate. This replication rate is fixed uniquely by requiring that the form of a free-photon distribution function be preserved, as required by the 2.7 K cosmic radiation. One finds that with this particular photon replication rate the units covariant formalism developed in Paper I actually predicts that the ratio of photon number to proton number in the universe varies as t to the 1/4, precisely in accord with LNH. The cosmological red-shift law is also derived and it is shown to differ considerably from the standard form of (nu)(R) - const.

  3. Cherenkov Radiation Control via Self-accelerating Wave-packets.

    Science.gov (United States)

    Hu, Yi; Li, Zhili; Wetzel, Benjamin; Morandotti, Roberto; Chen, Zhigang; Xu, Jingjun

    2017-08-18

    Cherenkov radiation is a ubiquitous phenomenon in nature. It describes electromagnetic radiation from a charged particle moving in a medium with a uniform velocity larger than the phase velocity of light in the same medium. Such a picture is typically adopted in the investigation of traditional Cherenkov radiation as well as its counterparts in different branches of physics, including nonlinear optics, spintronics and plasmonics. In these cases, the radiation emitted spreads along a "cone", making it impractical for most applications. Here, we employ a self-accelerating optical pump wave-packet to demonstrate controlled shaping of one type of generalized Cherenkov radiation - dispersive waves in optical fibers. We show that, by tuning the parameters of the wave-packet, the emitted waves can be judiciously compressed and focused at desired locations, paving the way to such control in any physical system.

  4. Human reactions to electromagnetic radiation in millimeter range

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, E.A.; Belyy, M.U.; Sit' ko, S.P.

    1985-01-01

    The article deals with a problem that is on the boundary of different disciplines. The authors discovered previously unknown effects of low-energy electromagnetic radiation on the human body. A total of 188 subjects, both healthy and sick in terms of medical diagnosis, were submitted to sensory tests. The vast majority of healthy subjects did not react to radiation in the range of 27-78 GHz and power density of up to 10 mW/cm/sup 2/. The same situation was also observed in many cases with patients. However, exposure of very specific parts of the body of sick subjects to electromagnetic waves at a fixed frequency in the range of 45-65 GHz elicited a sensory reaction in the region of the organ with a marked impairment, and this was an organ that was spatially remote from the irradiated region. It was established that the zones on the surface of the body that are the most sensitive to radiation coincide with acupuncture zones that are known in reflex acupuncture therapy. In addition to presentation of experimental results, the authors also propose a theoretical interpretation of the demonstrated effects.

  5. fdtd modelling of electromagnetic waves in stratified medium

    African Journals Online (AJOL)

    BRIAN

    (perfect electromagnetic conductors) based on. FDTD technique. The first is an analytic approach, based on the propagators and wave- splitting technique and the second is the numerical FDTD method. Hybrid finite element finite-difference time-domain. (FE/FDTD) technique for solving complex electromagnetic problems ...

  6. Electromagnetic Lead Screw for Potential Wave Energy Application

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Wu, Weimin

    2014-01-01

    This paper presents a new type electromagnetic lead screw (EMLS) intended for wave energy application. Similar to the mechanical lead screw, this electromagnetic version can transfer slow linear motion to high-rotational motion, offering gearing effects. Compared with the existing pure magnetic...

  7. Food collection and response to pheromones in an ant species exposed to electromagnetic radiation.

    Science.gov (United States)

    Cammaerts, Marie-Claire; Rachidi, Zoheir; Bellens, François; De Doncker, Philippe

    2013-09-01

    We used the ant species Myrmica sabuleti as a model to study the impact of electromagnetic waves on social insects' response to their pheromones and their food collection. We quantified M. sabuleti workers' response to their trail, area marking and alarm pheromone under normal conditions. Then, we quantified the same responses while under the influence of electromagnetic waves. Under such an influence, ants followed trails for only short distances, no longer arrived at marked areas and no longer orientated themselves to a source of alarm pheromone. Also when exposed to electromagnetic waves, ants became unable to return to their nest and recruit congeners; therefore, the number of ants collecting food increases only slightly and slowly. After 180 h of exposure, their colonies deteriorated. Electromagnetic radiation obviously affects social insects' behavior and physiology.

  8. Method of attenuation of electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Reh, G.P.; Mawdsley, G.E.; Yaffe, M.J.

    1990-05-30

    A method for the protection of matter, including humans, by attenuation of electromagnetic radiation comprises providing the matter with a protective layer of an inorganic composition formed from at least two elements, or compounds thereof, selected from different specified groups. The elements provide complementary attenuation of the radiation, and may be selected to optimize protection against specific energy spectra. The inorganic composition may be in a carrier e.g. a polymer. The method may be used in a variety of ways e.g. in protection of humans from x-rays, gamma rays or other radiation, or in packaging applications, protection of equipment sensitive to radiation or the like. The inorganic composition comprises elements or compounds of Ac, Bi, Au, Pb, Hg, Pu, Po, Pa, Tl, Th and/or U together with elements or compounds of Sb, Ba, Cd, Ce, Cs, La, Pb, In, I, Ag, Te, Sn, W, Au, Ir, Hg, Os, Pt, Re, Ta and/or Tl. (author).

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

    CERN Document Server

    Kupfer, Klaus

    2006-01-01

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

  10. Electromagnetic wave propagation in alternating material-metamaterial layered structures

    CERN Document Server

    Carrera-Escobedo, V H

    2016-01-01

    Using the transfer matrix method, we examine the parametric behavior of the transmittance of an electromagnetic plane wave propagating in the lossless regime through a periodic multilayered system as a function of the frequency and angle of incidence of the electromagnetic wave for the case in which the periodic structure comprises alternating material-metamaterial layers. A specific example of high transmittance at any angle of incidence in the visible region of the spectrum is identified

  11. Nonlinear multi-frequency electromagnetic wave propagation phenomena

    Science.gov (United States)

    Valovik, Dmitry V.

    2017-11-01

    A generalisation of the concept of monochromatic electromagnetic waves guided by layered waveguide structures filled with non-linear medium is introduced. This generalisation leads to guided waves of a novel type: a non-linear multi-frequency guided wave. The existence of such waves, in particular guide structures, is proven using the perturbation method. Numerical experiments are presented for non-linear 1- and 2-frequency guided waves in plane and cylindrical (with a circular cross-section) waveguides. Numerically, a novel non-linear effect is found for particular cases of non-linear multi-frequency guided waves. The suggested generalisation gives not only a unified approach to treat various electromagnetic wave propagation problems but also paves the way to study non-linear interactions of guided waves.

  12. Study of electromagnetic radiation produced by household equipment

    Science.gov (United States)

    Iagăr, A.; Popa, G. N.; Diniş, C. M.

    2017-05-01

    This paper presents the experimental study of electromagnetic radiation produced by different household equipment. Measurements were performed at various distances from the tested devices and in different operating modes of these, using the FA306 electromagnetic field analyzer. Also, it has been analyzed the cumulative effect of multiple sources. The experiments allowed the identification of measures to minimize the effects of exposure to artificial electromagnetic radiation produced by electrical household equipment.

  13. Discriminating electromagnetic radiation based on angle of incidence

    Science.gov (United States)

    Hamam, Rafif E.; Bermel, Peter; Celanovic, Ivan; Soljacic, Marin; Yeng, Adrian Y. X.; Ghebrebrhan, Michael; Joannopoulos, John D.

    2015-06-16

    The present invention provides systems, articles, and methods for discriminating electromagnetic radiation based upon the angle of incidence of the electromagnetic radiation. In some cases, the materials and systems described herein can be capable of inhibiting reflection of electromagnetic radiation (e.g., the materials and systems can be capable of transmitting and/or absorbing electromagnetic radiation) within a given range of angles of incidence at a first incident surface, while substantially reflecting electromagnetic radiation outside the range of angles of incidence at a second incident surface (which can be the same as or different from the first incident surface). A photonic material comprising a plurality of periodically occurring separate domains can be used, in some cases, to selectively transmit and/or selectively absorb one portion of incoming electromagnetic radiation while reflecting another portion of incoming electromagnetic radiation, based upon the angle of incidence. In some embodiments, one domain of the photonic material can include an isotropic dielectric function, while another domain of the photonic material can include an anisotropic dielectric function. In some instances, one domain of the photonic material can include an isotropic magnetic permeability, while another domain of the photonic material can include an anisotropic magnetic permeability. In some embodiments, non-photonic materials (e.g., materials with relatively large scale features) can be used to selectively absorb incoming electromagnetic radiation based on angle of incidence.

  14. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats☆

    Science.gov (United States)

    Mohammed, Haitham S.; Fahmy, Heba M.; Radwan, Nasr M.; Elsayed, Anwar A.

    2012-01-01

    In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day). EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR) than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested. PMID:25685416

  15. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats

    Directory of Open Access Journals (Sweden)

    Haitham S. Mohammed

    2013-03-01

    Full Text Available In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day. EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS and rapid eye movement sleep (REM sleep revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested.

  16. 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

    2003-01-01

    Full Text Available The influence of electromagnetic radiation from mobile antennas on humans is under discussion in va'rious groups ofscientists, This paper deals with the impact ofelectromagnetic radiation in a housing space. The space is assumedto be bordered by 5 walls of ferroconcrete and a door-window combination on the 6th side, the latter to be electromagnetically transparent. The transparent side of the housing is exposed to an electromagnetic wave. As the source ofradiation is considered to be far away from the housing, the radiation is regarded to be from a plane wave. Due to the high signal frequency and ferroconcrete walls, 5 sides ofthe 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.

  17. Finite Element Modeling of scattered electromagnetic waves for stroke analysis.

    Science.gov (United States)

    Priyadarshini, N; Rajkumar, E R

    2013-01-01

    Stroke has become one of the leading causes of mortality worldwide and about 800 in every 100,000 people suffer from stroke each year. The occurrence of stroke is ranked third among the causes of acute death and first among the causes for neurological dysfunction. Currently, Neurological examinations followed by medical imaging with CT, MRI or Angiography are used to provide better identification of the location and the type of the stroke, however they are neither fast, cost-effective nor portable. Microwave technology has emerged to complement these modalities to diagnose stroke as it is sensitive to the differences between the distinct dielectric properties of the brain tissues and blood. This paper investigates the possibility of diagnosing the type of stroke using Finite Element Analysis (FEA). The object of interest is a simulated head phantom with stroke, created with its specifying material characteristics like electrical conductivity and relative permittivity. The phantom is then placed in an electromagnetic field generated by a dipole antenna radiating at 1 GHz. The FEM forward model solver computes the scattered electromagnetic field by finding the solution for the Maxwell's wave equation in the head volume. Subsequently the inverse scattering problem is solved using the Contrast Source Inversion (CSI) method to reconstruct the dielectric profile of the head phantom.

  18. Transversality of electromagnetic waves in the calculus-based introductory physics course

    Energy Technology Data Exchange (ETDEWEB)

    Burko, Lior M [Department of Physics and Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 38599 (United States)

    2008-11-15

    Introductory calculus-based physics textbooks state that electromagnetic waves are transverse and list many of their properties, but most such textbooks do not bring forth arguments why this is so. Both physical and theoretical arguments are at a level appropriate for students of courses based on such books, and could be readily used by instructors of such courses. Here, we discuss two physical arguments (based on polarization experiments and on lack of monopole electromagnetic radiation) and the full argument for the transversality of (plane) electromagnetic waves based on the integral Maxwell equations. We also show, at a level appropriate for the introductory course, why the electric and magnetic fields in a wave are in phase and the relation of their magnitudes.

  19. Electromagnetic diffraction radiation of a subwavelength-hole array excited by an electron beam.

    Science.gov (United States)

    Liu, Shenggang; Hu, Min; Zhang, Yaxin; Li, Yuebao; Zhong, Renbin

    2009-09-01

    This paper explores the physics of the electromagnetic diffraction radiation of a subwavelength holes array excited by a set of evanescent waves generated by a line charge of electron beam moving parallel to the array. Activated by a uniformly moving line charge, numerous physical phenomena occur such as the diffraction radiation on both sides of the array as well as the electromagnetic penetration or transmission below or above the cut-off through the holes. As a result the subwavelength holes array becomes a radiation array. Making use of the integral equation with relevant Green's functions, an analytical theory for such a radiation system is built up. The results of the numerical calculations based on the theory agree well with that obtained by the computer simulation. The relation among the effective surface plasmon wave, the electromagnetic penetration or transmission of the holes and the diffraction radiation is revealed. The energy dependence of and the influence of the hole thickness on the diffraction radiation and the electromagnetic penetration or transmission are investigated in detail. Therefore, a distinct diffraction radiation phenomenon is discovered.

  20. On new electromagnetic waves in a multicomponent insulator

    NARCIS (Netherlands)

    Dubovik, V. M.

    The dispersion equation for additional transverse electromagnetic waves in a multicomponent amorphous insulator is analyzed in the vicinity of a narrow absorption line. Such waves can be excited due to spatial dispersion associated with fluctuation of the polarizability of insulator molecules. The

  1. An Apparatus for Constructing an Electromagnetic Plane Wave Model

    Science.gov (United States)

    Kneubil, Fabiana Botelho; Loures, Marcus Vinicius Russo; Amado, William

    2015-01-01

    In this paper we report on an activity aimed at building an electromagnetic wave. This was part of a class on the concept of mass offered to a group of 20 pre-service Brazilian physics teachers. The activity consisted of building a plane wave using an apparatus in which it is possible to fit some rods representing electric and magnetic fields into…

  2. Statistical Characterization of Electromagnetic Wave Propagation in Mine Environments

    KAUST Repository

    Yucel, Abdulkadir C.

    2013-01-01

    A computational framework for statistically characterizing electromagnetic (EM) wave propagation through mine tunnels and galleries is presented. The framework combines a multi-element probabilistic collocation method with a full-wave fast Fourier transform and fast multipole method accelerated surface integral equation-based EM simulator to statistically characterize fields from wireless transmitters in complex mine environments. 1536-1225 © 2013 IEEE.

  3. Joint evaluation of fracture azimuth by electromagnetic wave and elastic wave

    Science.gov (United States)

    Feng, Xuan; Liu, Cai; Wang, Qiao; Wang, Kai; Lu, Qi; Xue, Jian; Liang, Wenjing; Yu, Yue; Ren, Qianci

    2013-12-01

    With the multi-wave, multi-component seismic wave exploration, one can apply the anisotropy of fracture media to analyze the attributes of the fracture media, including the fracture azimuth. In the meantime, the techniques of full-polarimetric electromagnetic wave, including full-polarimetric borehole radar, can also be used to analyze the attributes of the fracture. However, the analysis precision of both the multi-component elastic wave exploration and full-polarimetric electromagnetic wave exploration is prone to the influence of noise and other factors. So far, some researchers have conducted studies on the joint inversion of electromagnetic waves and seismic waves. This paper develops evaluation techniques of fracture azimuth by electromagnetic wave, elastic wave, and joint analysis of coincident elastic reflection and electromagnetic data. Firstly, based on the shear wave splitting of elastic waves, this paper develops a statistical analysis technique which applies Pearson correlation coefficient to count and analyze the azimuth angle of fracture. Secondly, based on the information of electromagnetic polarization rotated by fracture, this paper develops a statistical analysis method of full-polarimetric electromagnetic waves which applies the maximum amplitude ratio between the co-polarization and cross-polarization to analyze the azimuth angle of fracture. Furthermore, based on the analysis result of the elastic wave and full-polarimetric electromagnetic wave, this paper develops a joint analysis technique which adopts the standard deviation. At last, authors in this study conduct joint detection experiments on the coincident fracture medium by using the ultrasonic and full-polarimetric ground penetrating radar. The experimental result indicates that both single geophysical methods are capable of analyzing the fracture azimuth angle, but the joint analysis is more accurate.

  4. Prediction and measurement of the electromagnetic environment of high-power medium-wave and short-wave broadcast antennas in far field.

    Science.gov (United States)

    Tang, Zhanghong; Wang, Qun; Ji, Zhijiang; Shi, Meiwu; Hou, Guoyan; Tan, Danjun; Wang, Pengqi; Qiu, Xianbo

    2014-12-01

    With the increasing city size, high-power electromagnetic radiation devices such as high-power medium-wave (MW) and short-wave (SW) antennas have been inevitably getting closer and closer to buildings, which resulted in the pollution of indoor electromagnetic radiation becoming worsened. To avoid such radiation exceeding the exposure limits by national standards, it is necessary to predict and survey the electromagnetic radiation by MW and SW antennas before constructing the buildings. In this paper, a modified prediction method for the far-field electromagnetic radiation is proposed and successfully applied to predict the electromagnetic environment of an area close to a group of typical high-power MW and SW wave antennas. Different from currently used simplified prediction method defined in the Radiation Protection Management Guidelines (H J/T 10. 3-1996), the new method in this article makes use of more information such as antennas' patterns to predict the electromagnetic environment. Therefore, it improves the prediction accuracy significantly by the new feature of resolution at different directions. At the end of this article, a comparison between the prediction data and the measured results is given to demonstrate the effectiveness of the proposed new method. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. [Effect of electromagnetic radiation on discharge activity of neurons in the hippocampus CA1 in rats].

    Science.gov (United States)

    Tong, Jun; Chen, Su; Liu, Xiang-Ming; Hao, Dong-Mei

    2013-09-01

    In order to explore effect of electromagnetic radiation on learning and memory ability of hippocampus neuron in rats, the changes in discharge patterns and overall electrical activity of hippocampus neuron after electromagnetic radiation were observed. Rat neurons discharge was recorded with glass electrode extracellular recording technology and a polygraph respectively. Radiation frequency of electromagnetic wave was 900 MHZ and the power was 10 W/m2. In glass electrode extracellular recording, the rats were separately irradiated for 10, 20, 30, 40, 50 and 60 min, every points repeated 10 times and updated interval of 1h, observing the changes in neuron discharge and spontaneous discharge patterns after electromagnetic radiation. In polygraph recording experiments, irradiation group rats for five days a week, 6 hours per day, repeatedly for 10 weeks, memory electrical changes in control group and irradiation group rats when they were feeding were repeatedly monitored by the implanted electrodes, observing the changes in peak electric digits and the largest amplitude in hippocampal CA1 area, and taking some electromagnetic radiation sampling sequence for correlation analysis. (1) Electromagnetic radiation had an inhibitory role on discharge frequency of the hippocampus CA1 region neurons. After electromagnetic radiation, discharge frequency of the hippocampus CA1 region neurons was reduced, but the changes in scale was not obvious. (2) Electromagnetic radiation might change the spontaneous discharge patterns of hippocampus CA1 region neurons, which made the explosive discharge pattern increased obviously. (3) Peak potential total number within 5 min in irradiation group was significantly reduced, the largest amplitude was less than that of control group. (4) Using mathematical method to make the correlation analysis of the electromagnetic radiation sampling sequence, that of irradiation group was less than that of control group, indicating that there was a tending

  6. [Fluorescence used to investigate the sensitivity of spinach chloroplast membrane to low intensity electromagnetic radiation].

    Science.gov (United States)

    Xi, Gang; Yang, Yun-Jing; Lu, Hong

    2009-07-01

    A system for studying biological effect of radio frequency electromagnetic field was developed. The system can form an area where electromagnetic wave with large frequency range is well distributed. The strength of electromagnetic wave was measured easily. Electromagnetic wave in the system did not have effect on environment. The sensitivity of spinach chloroplast membrane to low intensity electromagnetic radiation of 300 MHz under power density of 5 mW x cm(-2) was studied by the spectral analysis method of fluorescence of 8-anilino-1-naphthalene-sulfonic acid (ANS) and the changes in chlorophyll a (Chla) fluorescence parameters of spinach chloroplast membrane. The result showed that the position of spectrum of ANS fluorescence of spinach chloroplast membrane did not change, but the intensity of ANS fluorescence was obviously increased under the action of electromagnetic radiation with power density of 1-5 mW x cm(-2). There was an increase in the intensity of ANS fluorescence with the increase in electromagnetic radiation. The increase of ANS fluorescence of spinach chloroplast membrane showed that low level electromagnetic field induced the decrease in fluidity of chloroplast membrane compared with control experiment. The cause of the change in the fluidity could be related to the polarization of chloroplast membrane under the electromagnetic field. The analysis of Chla fluorescence parameters of spinach chloroplast membrane indicated that low level electromagnetic field of 300 MHz made the fluorescence parameters F0 and F(VI/)F(V) decrease, and F(V)/Fo, Fv/F(m) and deltaF(V)/T increase. It was showed that low level electromagnetic field caused the change of non-active center of photosystem II of spinach chloroplast membrane to active center and the increase in potential active and photochemical efficiency of PSII, and promoted the transmit process of electron in photosynthesis of chloroplast membrane of photosynthesis cell in spinach leaf. The study confirmed

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

    Science.gov (United States)

    Hahne, G. E.

    1992-01-01

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

  8. Metamaterial-based wideband electromagnetic wave absorber.

    Science.gov (United States)

    La Spada, Luigi; Vegni, Lucio

    2016-03-21

    In this paper, an analytical and numerical study of a new type of electromagnetic absorber, operating in the infrared and optical regime, is proposed. Absorption is obtained by exploiting Epsilon-Near-Zero materials. The structure electromagnetic properties are analytically described by using a new closed-form formula. In this way, it is possible to correlate the electromagnetic absorption properties of the structure with its geometrical characteristics. Good agreement between analytical and numerical results was achieved. Moreover, an absorption in a wide angle range (0°-80°), for different resonant frequencies (multi-band) with a large frequency bandwidth (wideband) for small structure thicknesses (d = λp/4) is obtained.

  9. Relativistic electromagnetic waves in an electron-ion plasma

    Science.gov (United States)

    Chian, Abraham C.-L.; Kennel, Charles F.

    1987-01-01

    High power laser beams can drive plasma particles to relativistic energies. An accurate description of strong waves requires the inclusion of ion dynamics in the analysis. The equations governing the propagation of relativistic electromagnetic waves in a cold electron-ion plasma can be reduced to two equations expressing conservation of energy-momentum of the system. The two conservation constants are functions of the plasma stream velocity, the wave velocity, the wave amplitude, and the electron-ion mass ratio. The dynamic parameter, expressing electron-ion momentum conversation in the laboratory frame, can be regarded as an adjustable quantity, a suitable choice of which will yield self-consistent solutions when other plasma parameters were specified. Circularly polarized electromagnetic waves and electrostatic plasma waves are used as illustrations.

  10. Absorption of electromagnetic and gravitational waves by Kerr black holes

    Science.gov (United States)

    Leite, Luiz C. S.; Dolan, Sam R.; Crispino, Luís C. B.

    2017-11-01

    We calculate the absorption cross section for planar waves incident upon Kerr black holes, and present a unified picture for scalar, electromagnetic and gravitational waves. We highlight the spin-helicity effect that arises from a coupling between the rotation of the black hole and the helicity of a circularly-polarized wave. For the case of on-axis incidence, we introduce an extended 'sinc approximation' to quantify the spin-helicity effect in the strong-field regime.

  11. Geodetic refraction effects of electromagnetic wave propagation through the atmosphere

    CERN Document Server

    1984-01-01

    With very few exceptions, geodetic measurements use electro­ magnetic radiation in order to measure directions, distances, time delays, and Doppler frequency shifts, to name the main ter­ restrial and space observables. Depending on the wavelength of the radiation and the purpose of the measurements, the follow­ ing parameters of the electromagnetic wave are measured: ampli­ tude, phase, angle-of-arrival, polarisation and frequency. Ac­ curate corrections have to be applied to the measurements in order to take into account the effects of the intervening medium between transmitter and receiver. The known solutions use at­ mospheric models, special observation programs, remote sensing techniques and instrumental methods. It has been shown that the effects of the earth's atmospheric envelope present a fundamental limitation to the accuracy and precision of geodetic measurements. This applies equally to ter­ restrial and space applications. Instrumental accuracies are al­ ready below the atmospherically i...

  12. Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets

    Science.gov (United States)

    Yoo, Young Joon; Ju, Sanghyun; Park, Sang Yoon; Ju Kim, Young; Bong, Jihye; Lim, Taekyung; Kim, Ki Won; Rhee, Joo Yull; Lee, YoungPak

    2015-01-01

    Perfect metamaterial absorber (PMA) can intercept electromagnetic wave harmful for body in Wi-Fi, cell phones and home appliances that we are daily using and provide stealth function that military fighter, tank and warship can avoid radar detection. We reported new concept of water droplet-based PMA absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very plentiful on the earth. If arranging water droplets with particular height and diameter on material surface through the wettability of material surface, meta-properties absorbing electromagnetic wave perfectly in GHz wide-band were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet–height and diameter– and apply to various flexible and/or transparent substrates such as plastic, glass and paper. In addition, this research examined how electromagnetic wave can be well absorbed in water droplets with low electrical conductivity unlike metal-based metamaterials inquiring highly electrical conductivity. Those results are judged to lead broad applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including transparent and bendable materials. PMID:26354891

  13. Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets.

    Science.gov (United States)

    Yoo, Young Joon; Ju, Sanghyun; Park, Sang Yoon; Ju Kim, Young; Bong, Jihye; Lim, Taekyung; Kim, Ki Won; Rhee, Joo Yull; Lee, YoungPak

    2015-09-10

    Perfect metamaterial absorber (PMA) can intercept electromagnetic wave harmful for body in Wi-Fi, cell phones and home appliances that we are daily using and provide stealth function that military fighter, tank and warship can avoid radar detection. We reported new concept of water droplet-based PMA absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very plentiful on the earth. If arranging water droplets with particular height and diameter on material surface through the wettability of material surface, meta-properties absorbing electromagnetic wave perfectly in GHz wide-band were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet-height and diameter- and apply to various flexible and/or transparent substrates such as plastic, glass and paper. In addition, this research examined how electromagnetic wave can be well absorbed in water droplets with low electrical conductivity unlike metal-based metamaterials inquiring highly electrical conductivity. Those results are judged to lead broad applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including transparent and bendable materials.

  14. Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets

    Science.gov (United States)

    Yoo, Young Joon; Ju, Sanghyun; Park, Sang Yoon; Ju Kim, Young; Bong, Jihye; Lim, Taekyung; Kim, Ki Won; Rhee, Joo Yull; Lee, Youngpak

    2015-09-01

    Perfect metamaterial absorber (PMA) can intercept electromagnetic wave harmful for body in Wi-Fi, cell phones and home appliances that we are daily using and provide stealth function that military fighter, tank and warship can avoid radar detection. We reported new concept of water droplet-based PMA absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very plentiful on the earth. If arranging water droplets with particular height and diameter on material surface through the wettability of material surface, meta-properties absorbing electromagnetic wave perfectly in GHz wide-band were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet-height and diameter- and apply to various flexible and/or transparent substrates such as plastic, glass and paper. In addition, this research examined how electromagnetic wave can be well absorbed in water droplets with low electrical conductivity unlike metal-based metamaterials inquiring highly electrical conductivity. Those results are judged to lead broad applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including transparent and bendable materials.

  15. 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.

  16. A broadband and omnidirectional electromagnetic wave concentrator with gradient woodpile structure.

    Science.gov (United States)

    Yin, Ming; Tian, Xiao Yong; Wu, Ling Ling; Li, Di Chen

    2013-08-12

    We present the first realized three-dimensional (3D) practical implementation of the so called "optical black hole" in microwave frequencies, an electromagnetic (EM) concentrator. The 3D EM wave concentrator was designed with non-resonant gradient index (GRIN) 3D woodpile photonic crystals (PCs) structure in metamaterial regime, and fabricated by Stereolithography (SL) process. Omnidirectional EM wave capture and absorbing ability of the device in a broad bandwidth (12GHz-15GHz) were validated by full-wave simulation and experiments. Such devices may have applications in microwave energy harvesting and radiation detector.

  17. Measurement of the environmental broadband electromagnetic waves in a mid-size European city.

    Science.gov (United States)

    Fernández-García, R; Gil, I

    2017-10-01

    In this paper, the level of exposure to broadband radiofrequency electromagnetic field in a mid-size European city was evaluated in accordance with the International Commission on Non-ionizing Radiation Protection guidelines from 1998. With the aim to analyse all the potential electromagnetic waves present in the city up to 18GHz, a total of 271 locations distributed along Terrassa (Spain) have been measured. To show the results in an easy-to-interpret way by the citizen, the results have been represented in a set of raster maps. The measurement results obtained showed that the electromagnetic wave measured in all broadband frequency range along the city is much lower than the safety level according to the international regulations for both public and occupational sectors. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Electromagnetic wave chaos in gradient refractive index optical cavities.

    Science.gov (United States)

    Wilkinson, P B; Fromhold, T M; Taylor, R P; Micolich, A P

    2001-06-11

    Electromagnetic wave chaos is investigated using two-dimensional optical cavities formed in a cylindrical gradient refractive index lens with reflective surfaces. When the planar ends of the lens are cut at an angle to its axis, the geometrical ray paths are chaotic. In this regime, the electromagnetic mode spectrum of the cavity is modulated by both real and ghost periodic ray paths, which also "scar" the electric field intensity distributions of many modes. When the cavity is coupled to waveguides, the eigenmodes generate complex series of resonant peaks in the electromagnetic transmission spectrum.

  19. [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.

  20. Electromagnetic Radiation Reaction in General Relativity.

    Science.gov (United States)

    O'Donnell, Nuala

    Available from UMI in association with The British Library. This thesis examines the electromagnetic radiation reaction felt by a charged body falling freely in an external gravitational field in general relativity. The original objective was to find a new derivation of the radiation reaction force F^{i} of DeWitt and DeWitt^1 which was calculated for the special case of a point charge falling in slow motion in a weak, static gravitational field: F ^{i} = {2over 3}e^2R^{i}_{0j0 }v^{j}. This may be thought of as a local expression since it involves the particle's velocity v^{j } and the local Riemann curvature tensor R ^{i}_{0j0}. Its derivation involves integrals over the whole history of the particle, covering distances of approximately the length scale on which R^{i}_{0j0 } changes. This is different from calculations of the Abraham-Lorentz force of flat space-time involving integrals over distances only a few times the size of the charge. This work was motivated by the wish to find a "local" derivation of the local reaction force. Using Schutz's^2 local initial value method to solve the problem of a charged, rigid, spherically symmetric body moving in an external gravitational field of arbitrary metric. Calculations are done in a Riemann normal coordinate system ^3 and are only valid in a normal neighbourhood of the origin, where geodesics have not begun to cross one another. We solve Maxwell's equations for the self -force by making a slow-motion approximation and keeping terms to first order only in the Riemann tensor and velocity. It is surprising that we find no local radiation reaction. Consider two particles in a static spacetime with the same initial conditions at t = 0. Particle A is that of DeWitt and DeWitt; it feels a reaction force F^{i} = {2over 3}e^2R^{i }_{0j0}v^{j}. Particle B is accelerated from rest to the same small velocity; it feels no reaction force. The two particles therefore follow different trajectories. We conclude that there is a

  1. 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

  2. A metasurface carpet cloak for electromagnetic, acoustic and water waves.

    Science.gov (United States)

    Yang, Yihao; Wang, Huaping; Yu, Faxin; Xu, Zhiwei; Chen, Hongsheng

    2016-01-29

    We propose a single low-profile skin metasurface carpet cloak to hide objects with arbitrary shape and size under three different waves, i.e., electromagnetic (EM) waves, acoustic waves and water waves. We first present a metasurface which can control the local reflection phase of these three waves. By taking advantage of this metasurface, we then design a metasurface carpet cloak which provides an additional phase to compensate the phase distortion introduced by a bump, thus restoring the reflection waves as if the incident waves impinge onto a flat mirror. The finite element simulation results demonstrate that an object can be hidden under these three kinds of waves with a single metasurface cloak.

  3. Adverse reproductive events and electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, W.; Ouellet-Hellstrom, R.

    1991-07-31

    In 1989 approximately 42,000 questionnaires were mailed to female physical therapists to assess the risk of adverse reproductive effects among those exposed to electromagnetic radiation at radiofrequencies. From the resulting data, the risk of early recognized fetal loss was assessed using a nested case-control design. The cases (1753 miscarriages) were matched to controls (1753 other pregnancies except ectopics) on mothers age at conception and the number of years elapsed between conception and interview. The results of the study indicate that female physical therapists who work with microwave diathermy 6 months prior to the pregnancy and/or during the first trimester were at increased risk of experiencing a recognized early fetal loss, but female physical therapists who work with shortwave diathermy were not at an increased risk. This association was shown to hold even when the mother's age at conception, the number of years elapsed between conception and interview, the number of prior early fetal losses, mother's conditions ever diagnosed, and use of other modalities were controlled. The data also suggest a possible association between exposure to transcutaneous electrical nerve stimulation with an elevated risk of early recognized fetal loss.

  4. A Study on the Influence of Electromagnetic Radiation on Nervous System

    Directory of Open Access Journals (Sweden)

    Dong Xinlin

    2015-01-01

    Full Text Available Being applied widely, electromagnetic wave is closely related with our life. But this material has brought pollutions to the environment as well as influences on functions of organisms. In order to explore the influence of electromagnetic radiation on nervous system, this paper takes adult mice on 35th day as research objects, designs a water maze experiment and explores features of escaping latency of mice in the control group and in the group with radiation. In this research, methods of building a GHz TEM cell and a simulation model of mouse head with AutoCAD 2010 and XFDTD are provided, verifying that the simulation model meets the needs of the experiment. It concludes that the electromagnetic radiation causes memory deterioration of mice, and exerts its certain influence on nervous system.

  5. Quadrupole electromagnetic radiation of an oscillating charged droplet

    Science.gov (United States)

    Grigor'ev, A. I.; Kolbneva, N. Yu.; Shiryaeva, S. O.

    2017-06-01

    Analytical calculations using the first order of smallness with respect to dimensionless amplitude of oscillations show that the intensity of electromagnetic radiation of a charged droplet is determined by time-dependent quadrupole moment.

  6. Enhanced transmission of electromagnetic waves through 1D plasmonic crystals.

    Science.gov (United States)

    So, Jin-Kyu; Jung, Hoe-Cheon; Min, Sun-Hong; Jang, Kyu-Ha; Bak, Seung-Ho; Park, Gun-Sik

    2010-09-13

    Transmission of electromagnetic waves through thick perfect conducting slabs perforated by one-dimensional arrays of rectangular holes was studied experimentally in the microwave frequency range. The observed thickness-dependent transmission clearly exhibits the evanescent and propagating nature of the involved electromagnetic excitations on the considered structures, which are effective surface plasmons and localized waveguide resonances, respectively. The 1D crystals showing transmission based on localized resonances further manifests the frequency-dependent effective refractive index depending on the filling ratio of the holes and accompanies resonant guided wave propagation.

  7. Cell therapy for spinal cord injury informed by electromagnetic waves.

    Science.gov (United States)

    Finnegan, Jack; Ye, Hui

    2016-10-01

    Spinal cord injury devastates the CNS, besetting patients with symptoms including but not limited to: paralysis, autonomic nervous dysfunction, pain disorders and depression. Despite the identification of several molecular and genetic factors, a reliable regenerative therapy has yet to be produced for this terminal disease. Perhaps the missing piece of this puzzle will be discovered within endogenous electrotactic cellular behaviors. Neurons and stem cells both show mediated responses (growth rate, migration, differentiation) to electromagnetic waves, including direct current electric fields. This review analyzes the pathophysiology of spinal cord injury, the rationale for regenerative cell therapy and the evidence for directing cell therapy via electromagnetic waves shown by in vitro experiments.

  8. Electromagnetic Wave Propagation Models for Multiple-Diffraction Scenarios

    Directory of Open Access Journals (Sweden)

    Mehmet Barış TABAKCIOĞLU

    2014-04-01

    Full Text Available Electromagnetic wave propagation models have been used for coverage estimation and field prediction at the receiver to make more reliable and efficient digital broadcasting systems. Propagation models can be classified into two groups as numerical and ray tracing based models. There is a tradeoff between computation time and accuracy of field prediction among electromagnetic wave propagation models. Although numerical models predict accurately, it requires more computation times. Ray tracing based models predicts the field strength less accurately with lower computation time. Many propagation models have been developed to provide optimum solution for accuracy and computation time

  9. Study of interrelation between electromagnetic radiation and rock strength

    Science.gov (United States)

    Yavorovich, L. V.; Bespal'ko, A. A.; Fedotov, P. I.; Pomishin, E. K.

    2016-02-01

    The paper presents the study of the electromagnetic radiation of real rock samples under acoustic impact. The test samples are made of kerns from the iron ore mine with different petrophysical features and strength. The study has shown that the electromagnetic radiation parameters are related to the sample strength. However, this dependence is not observed for samples with magnetite that can be due to individual structural-textural features and quartz inclusions.

  10. What is the impact of electromagnetic waves on epileptic seizures?

    Science.gov (United States)

    Cinar, Nilgun; Sahin, Sevki; Erdinc, Oguz O

    2013-05-10

    The effects of electromagnetic waves (EMWs) on humans and their relationship with various disorders have been investigated. We aimed to investigate the effects of exposure to different frequencies of EMWs in various durations in a mouse epilepsy model induced by pentylenetetrazole (PTZ). A total of 180 4-week-old male mice weighing 25-30 g were used in this study. Each experimental group consisted of 10 mice. They were exposed to 900, 700, 500, 300, and 100 MHz EMWs for 20 hours, 12 hours and 2 hours. Following electromagnetic radiation exposure, 60 mg/kg of PTZ was injected intraperitoneally to all mice. Each control was also injected with PTZ without any exposure to EMW. The latency of initial seizure and most severe seizure onset were compared with controls. The shortest initial seizure latency was noted in the 12-hour group, followed by the 700 MHz. The mean initial seizure latencies in the 2-hour EMW exposed group was significantly shorter compared to that in the 12- and 20-hour groups. There was no significant difference between 12- and 20-hour EMW exposed groups. There was a significant difference between control and 2- and 10-hour EMW exposed groups. No statistically significant differences were noted in mean latencies of the most severe seizure latency, following 20-, 12-, and 2- hour EMW exposed groups and control groups. Our findings suggest that acute exposure to EMW may facilitate epileptic seizures, which may be independent of EMW exposure time. This information might be important for patients with epilepsy. Further studies are needed.

  11. Study of a condition for the mode conversion from purely perpendicular electrostatic waves to electromagnetic waves

    Energy Technology Data Exchange (ETDEWEB)

    Kalaee, Mohammad Javad, E-mail: mjkalaee@ut.ac.ir [Space Physics Group, Institute of Geophysics, University of Tehran (Iran, Islamic Republic of); Katoh, Yuto, E-mail: yuto@stpp.gp.tohoku.ac.jp [Department of Geophysics, Graduate School of Science, Tohoku University (Japan)

    2016-07-15

    One of the mechanisms for generating electromagnetic plasma waves (Z-mode and LO-mode) is mode conversion from electrostatic waves into electromagnetic waves in inhomogeneous plasma. Herein, we study a condition required for mode conversion of electrostatic waves propagating purely perpendicular to the ambient magnetic field, by numerically solving the full dispersion relation. An approximate model is derived describing the coupling between electrostatic waves (hot plasma Bernstein mode) and Z-mode waves at the upper hybrid frequency. The model is used to study conditions required for mode conversion from electrostatic waves (electrostatic electron cyclotron harmonic waves, including Bernstein mode) into electromagnetic plasma waves (LO-mode). It is shown that for mode conversion to occur in inhomogeneous plasma, the angle between the boundary surface and the magnetic field vector should be within a specific range. The range of the angle depends on the norm of the k vector of waves at the site of mode conversion in the inhomogeneous region. The present study reveals that inhomogeneity alone is not a sufficient condition for mode conversion from electrostatic waves to electromagnetic plasma waves and that the angle between the magnetic field and the density gradient plays an important role in the conversion process.

  12. Propagation of Electromagnetic Waves in Extremely Dense Media

    CERN Document Server

    Masood, Samina

    2016-01-01

    We study the propagation of electromagnetic (EM) waves in extremely dense exotic systems with very unique properties. These EM waves develop a longitudinal component due to its interaction with the medium. Renormalization scheme of QED is used to understand the propagation of EM waves in both longitudinal and transverse directions. The propagation of EM waves in a quantum statistically treatable medium affects the properties of the medium itself. The electric permittivity and the magnetic permeability of the medium are modified and influence the related behavior of the medium. All the electromagnetic properties of a medium become a function of temperature and chemical potential of the medium. We study in detail the modifications of electric permittivity and magnetic permeability and other related properties of a medium in the superdense stellar objects.

  13. An investigation into underground navigation using electromagnetic waves

    CERN Document Server

    Tillema, N J

    2000-01-01

    findings. The lateral wave starts at the source underground, travels to the boundary, follows the air-ground boundary and then propagates back into the ground to the receiver antenna. As the wave travels a significant part of its path in air, it was less susceptible to irregularities underground. Measurement of the phase has shown it to be sensitive to errors caused by reflections. This was the reason why reliable information of the phase was not always available during the measurements. The field trials have shown the possibility of using electromagnetic waves to track a moving transmitter underground. Any system that estimates the underground displacement of the transmitter should have two or more receiver antennas. The experiments have shown a possible accuracy of such a system of approximately 2 m or less. This thesis explores the possibility of measuring the movement of an underground transmitter using electromagnetic waves. The displacement of the transmitter was estimated based on the magnitude and pha...

  14. Electromagnetic Radiation Originating from Unstable Electron Oscillations

    DEFF Research Database (Denmark)

    Juul Rasmussen, Jens; Pécseli, Hans

    1975-01-01

    Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function.......Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function....

  15. Effects of electromagnetic radiation on the hemorheology of rats

    Science.gov (United States)

    Huang, Zhiwei; Tian, Tian; Xiao, Bo; Li, Wen

    2017-01-01

    The current work examines the effects of electromagnetic radiation on the hemorheology to provide an experimental basis for radiation protection. Electromagnetic radiation was generated by a Helmholtz coil constructed from copper wire. There were six rats altogether: three rats in the experimental group, and three rats in the control group. The rats in the experimental group were continuously exposed to radiation for 10 hours every day, and rats in the control group remained in a normal environment. After 30 days, the characteristics of hemorheology of the two groups were compared. The average plasma viscosity, whole blood high shear velocity, and whole blood low shear viscosity were lower in rats in the experimental group than in rats in the control group, while the whole blood shear viscosity was higher in the experimental group than in the control group. Results suggest that long term exposure to electromagnetic radiation does have certain impacts on the cardiovascular system, deeming it necessary to take preventative measures.

  16. Mathematical models for dispersive electromagnetic waves: an overview

    OpenAIRE

    Cassier, Maxence; Joly, Patrick; Kachanovska, Maryna

    2017-01-01

    In this work, we investigate mathematical models for electromagnetic wave propagation in dispersive isotropic media. We emphasize the link between physical requirements and mathematical properties of the models. A particular attention is devoted to the notion of non-dissipativity and passivity. We consider successively the case of so-called local media and general passive media. The models are studied through energy techniques, spectral theory and dispersion analysis of plane waves. For makin...

  17. Through casing weak electromagnetic wave signal detection and application

    Science.gov (United States)

    Li, Hui; Zhu, Xi-Fang; Cui, Cui-Mei

    2017-07-01

    Electromagnetic measurement technology is an important method for instrument parameters calibration, detection performance evaluation and complex system theory verification. In this paper, self-adaptive finite element method has been used to compute and analyze the weak electromagnetic wave signal, which is produced by changing electrode structure, transmitting frequency and antenna spacing of the through casing electromagnetic measurement tool. Numerical simulation results show that the detection depth of the tool can be influenced by the electrode structure can have the influence on, the resolution of high-resistivity and low-resistivity formation can be improved by transmitting frequency, the detection accuracy and detection depth of the through casing electromagnetic measurement tool can be influenced by the change of antenna spacing.

  18. Molding acoustic, electromagnetic and water waves with a single cloak.

    Science.gov (United States)

    Xu, Jun; Jiang, Xu; Fang, Nicholas; Georget, Elodie; Abdeddaim, Redha; Geffrin, Jean-Michel; Farhat, Mohamed; Sabouroux, Pierre; Enoch, Stefan; Guenneau, Sébastien

    2015-06-09

    We describe two experiments demonstrating that a cylindrical cloak formerly introduced for linear surface liquid waves works equally well for sound and electromagnetic waves. This structured cloak behaves like an acoustic cloak with an effective anisotropic density and an electromagnetic cloak with an effective anisotropic permittivity, respectively. Measured forward scattering for pressure and magnetic fields are in good agreement and provide first evidence of broadband cloaking. Microwave experiments and 3D electromagnetic wave simulations further confirm reduced forward and backscattering when a rectangular metallic obstacle is surrounded by the structured cloak for cloaking frequencies between 2.6 and 7.0 GHz. This suggests, as supported by 2D finite element simulations, sound waves are cloaked between 3 and 8 KHz and linear surface liquid waves between 5 and 16 Hz. Moreover, microwave experiments show the field is reduced by 10 to 30 dB inside the invisibility region, which suggests the multi-wave cloak could be used as a protection against water, sonic or microwaves.

  19. Molding acoustic, electromagnetic and water waves with a single cloak

    KAUST Repository

    Xu, Jun

    2015-06-09

    We describe two experiments demonstrating that a cylindrical cloak formerly introduced for linear surface liquid waves works equally well for sound and electromagnetic waves. This structured cloak behaves like an acoustic cloak with an effective anisotropic density and an electromagnetic cloak with an effective anisotropic permittivity, respectively. Measured forward scattering for pressure and magnetic fields are in good agreement and provide first evidence of broadband cloaking. Microwave experiments and 3D electromagnetic wave simulations further confirm reduced forward and backscattering when a rectangular metallic obstacle is surrounded by the structured cloak for cloaking frequencies between 2.6 and 7.0 GHz. This suggests, as supported by 2D finite element simulations, sound waves are cloaked between 3 and 8 KHz and linear surface liquid waves between 5 and 16 Hz. Moreover, microwave experiments show the field is reduced by 10 to 30 dB inside the invisibility region, which suggests the multi-wave cloak could be used as a protection against water, sonic or microwaves. © 2015, Nature Publishing Group. All rights reserved.

  20. Negative electromagnetic plane-wave force in gain media.

    Science.gov (United States)

    Webb, Kevin J; Shivanand

    2011-11-01

    It is shown that a uniform electromagnetic plane wave can exert a negative force on a homogeneous medium with gain when there is no component of the electric field in that direction. A physical interpretation for this force is given, along with an estimate of the strength achievable in an experiment.

  1. Electromagnetic Wave Absorbing Properties of Amorphous Carbon Nanotubes

    Science.gov (United States)

    Zhao, Tingkai; Hou, Cuilin; Zhang, Hongyan; Zhu, Ruoxing; She, Shengfei; Wang, Jungao; Li, Tiehu; Liu, Zhifu; Wei, Bingqing

    2014-01-01

    Amorphous carbon nanotubes (ACNTs) with diameters in the range of 7–50 nm were used as absorber materials for electromagnetic waves. The electromagnetic wave absorbing composite films were prepared by a dip-coating method using a uniform mixture of rare earth lanthanum nitrate doped ACNTs and polyvinyl chloride (PVC). The microstructures of ACNTs and ACNT/PVC composites were characterized using transmission electron microscope and X-ray diffraction, and their electromagnetic wave absorbing properties were measured using a vector-network analyzer. The experimental results indicated that the electromagnetic wave absorbing properties of ACNTs are superior to multi-walled CNTs, and greatly improved by doping 6 wt% lanthanum nitrate. The reflection loss (R) value of a lanthanum nitrate doped ACNT/PVC composite was −25.02 dB at 14.44 GHz, and the frequency bandwidth corresponding to the reflector loss at −10 dB was up to 5.8 GHz within the frequency range of 2–18 GHz. PMID:25007783

  2. FDTD Modelling of Electromagnetic waves in Stratified Medium ...

    African Journals Online (AJOL)

    The technique is an adaptation of the finite-difference time domain (FDTD) approach usually applied to model electromagnetic wave propagation. In this paper a simple 2D implementation of FDTD algorithm in mathematica environment is presented. Source implementation and the effect of conductivity on the incident field ...

  3. Three-dimensional accelerating electromagnetic waves.

    Science.gov (United States)

    Bandres, Miguel A; Alonso, Miguel A; Kaminer, Ido; Segev, Mordechai

    2013-06-17

    We present a general theory of three-dimensional non-paraxial spatially-accelerating waves of the Maxwell equations. These waves constitute a two-dimensional structure exhibiting shape-invariant propagation along semicircular trajectories. We provide classification and characterization of possible shapes of such beams, expressed through the angular spectra of parabolic, oblate and prolate spheroidal fields. Our results facilitate the design of accelerating beams with novel structures, broadening scope and potential applications of accelerating beams.

  4. On the Feasibility of Gap Detection of Power Transformer Partial Discharge UHF Signals: Gap Propagation Characteristics of Electromagnetic Waves

    Directory of Open Access Journals (Sweden)

    Xiaoxing Zhang

    2017-10-01

    Full Text Available This study analyzed the transformer electromagnetic gap propagation characteristics. The influence of gap size is also analyzed, and the results experimentally verified. The obtained results indicated that the gap propagation characteristics of electromagnetic wave signals radiated by the partial discharge (PD source in different directions are substantially different. The intensity of the electromagnetic wave in the gap reaches a maximum at a gap height of 1 cm; and inside the gap, the intensity of the electromagnetic wave depicted an increasing trend at the tail area of the gap. Finally, from the obtained results, some suggestions on where to install sensors in practical systems for ultra high frequency (UHF PD signal detection in the transformer gap are provided. The obtained results confirmed the feasibility of using this approach. These results can be seen as a benchmark and a challenge for further research in this field.

  5. Self-Consistent Ring Current/Electromagnetic Ion Cyclotron Waves Modeling

    Science.gov (United States)

    Khazanov, G. V.; Gamayunov, K.; Gallagher, D.

    2006-12-01

    The self-consistent treatment of ring current (RC) ion dynamics and electromagnetic ion cyclotron (EMIC) waves, which are thought to exert important influences on dynamic ion evolution and are an important missing element in our understanding of the storm-and recovery-time ring current evolution. For example, the EMIC waves cause the RC decay on a time scale of about one hour or less during the main phase of storms. The oblique EMIC waves damp due to Landau resonance with the thermal plasmaspheric electrons, and subsequent transport of the dissipating wave energy into the ionosphere below causes an ionosphere temperature enhancement. Under certain conditions, relativistic electrons, with energies ~1 MeV, can be removed from the outer radiation belt by EMIC wave scattering during a magnetic storm. That is why the modeling of EMIC waves is a critical and timely issue in magnetospheric physics. This study will generalize the self-consistent theoretical description of RC ions and EMIC waves that has been developed by Khazanov et al. [2002, 2003] and include the heavy ions and propagation effects of EMIC waves in global dynamic modeling of self-consistent RC - EMIC waves coupling. The results of our newly developed model will be presented, focusing mainly on the dynamics of EMIC waves and comparison of these results with the previous global RC modeling studies devoted to EMIC waves formation. We will also discuss RC ion precipitations and wave induced thermal electron fluxes into the ionosphere.

  6. Measurement and analysis of electromagnetic pulses radiated from a charged copper pipe. Taidendo pipe kara hoshasareru denji pulse no sokutei to kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Masugi, M.; Murakawa, K.; Kuwabara, N.; Amemiya, F. (Nippon Telegraph and Telephone Corp., Tokyo (Japan))

    1992-12-20

    The purpose of this paper is to clarify the characteristics of electromagnetic wave accompanied with the electrostatic discharge. Experimental and analytical results on electromagnetic pulses radiated from a charged copper pipe are described. The electromagnetic pulses radiated from the copper pipe were measured by using electromagnetic field measuring antennas, such as loop antenna, biconical antenna, and double ridged guide antenna. Electromagnetic energy of the electromagnetic pulses was analyzed by integrating energy spectrums of three frequency domains of 1 to 30MHz, 30 to 300MHz, and 300 to 750MHz. Consequently, it was found that the radiated electromagnetic energy by discharge does not always increase in proportion to charging voltage. In addition, it was shown that high speed touch discharges by charging voltage of 7 or 10kV increase electromagnetic energy especially in the frequency region of 300 to 750MHz. 13 refs., 10 figs., 1 tab.

  7. Electromagnetic wave dynamics in matter-wave superradiant scattering.

    Science.gov (United States)

    Deng, L; Payne, M G; Hagley, E W

    2010-02-05

    We present a small-signal wave propagation theory on matter-wave superradiant scattering. We show, in a longitudinally excited condensate, that the backward-propagating, superradiantly generated optical field propagates with ultraslow group velocity and that the small-signal gain profile has a Bragg resonance. We further show a unidirectional suppression of optical superradiant scattering, and explain why matter-wave superradiance can occur only when the pump laser is red detuned. This is the first analytical theory on field propagation in matter-wave superradiance that can explain all matter-wave superradiance experiments to date that used a single-frequency, long-pulse, red-detuned laser.

  8. Does the cellphone radio-frequency electromagnetic radiation ...

    African Journals Online (AJOL)

    Debate regarding the biological effect of electromagnetic radiation has been recently raised. The effects of this radiation on locomotor activity are not well known. Hence, in this ... Interestingly, an hour exposure to the cellphone ringing mode did not significantly affect the fly movement speed in the negative geotaxis assay.

  9. Reflection of electromagnetic waves at a biaxial-isotropic interface

    Science.gov (United States)

    Njoku, E. G.

    1983-01-01

    The reflection of electromagnetic waves at a plane boundary between isotropic and biaxial media has been investigated using the kDB approach. The general case has been considered in which the principal dielectric axes of the biaxial medium are oriented at an arbitrary angle to the normal of the plane boundary. In general, two characteristic waves propagate in the biaxial medium, leading to coupling of vertical and horizontal polarizations in the reflected waves. Some special cases are illustrated. The results have applications to problems in remote sensing and integrated optics.

  10. Absorption of electromagnetic and gravitational waves by Kerr black holes

    Directory of Open Access Journals (Sweden)

    Luiz C.S. Leite

    2017-11-01

    Full Text Available We calculate the absorption cross section for planar waves incident upon Kerr black holes, and present a unified picture for scalar, electromagnetic and gravitational waves. We highlight the spin-helicity effect that arises from a coupling between the rotation of the black hole and the helicity of a circularly-polarized wave. For the case of on-axis incidence, we introduce an extended ‘sinc approximation’ to quantify the spin-helicity effect in the strong-field regime.

  11. Transmission of electromagnetic waves through sub-wavelength channels

    DEFF Research Database (Denmark)

    Zhang, Jingjing; Luo, Yu; Mortensen, Asger

    2010-01-01

    We propose a method of tunneling electromagnetic (EM) waves through a channel with sub-wavelength cross section. By filling the channel with high-ε isotropic material and implementing two matching layers with uniaxial metamterial substrates, the guided waves can go through the narrow channel...... without being cut off, as if it has just passed through the original empty waveguide. Both the magnitude and phase information of the EM fields can be effectively restored after passing this channel, regardless of the polarization of the incoming wave. The performance of this subwavelength channel, which...

  12. Transmission of electromagnetic waves through sub-wavelength channels.

    Science.gov (United States)

    Zhang, Jingjing; Luo, Yu; Mortensen, Niels Asger

    2010-02-15

    We propose a method of tunneling electromagnetic (EM) waves through a channel with sub-wavelength cross section. By filling the channel with high-epsilon isotropic material and implementing two matching layers with uniaxial metamterial substrates, the guided waves can go through the narrow channel without being cut off, as if it has just passed through the original empty waveguide. Both the magnitude and phase information of the EM fields can be effectively restored after passing this channel, regardless of the polarization of the incoming wave. The performance of this sub-wavelength channel, which is designed with coordinate transformation methodology, is studied theoretically and numerically.

  13. Precision cosmology from future lensed gravitational wave and electromagnetic signals.

    Science.gov (United States)

    Liao, Kai; Fan, Xi-Long; Ding, Xuheng; Biesiada, Marek; Zhu, Zong-Hong

    2017-10-27

    The standard siren approach of gravitational wave cosmology appeals to the direct luminosity distance estimation through the waveform signals from inspiralling double compact binaries, especially those with electromagnetic counterparts providing redshifts. It is limited by the calibration uncertainties in strain amplitude and relies on the fine details of the waveform. The Einstein telescope is expected to produce 10 4 -10 5 gravitational wave detections per year, 50-100 of which will be lensed. Here, we report a waveform-independent strategy to achieve precise cosmography by combining the accurately measured time delays from strongly lensed gravitational wave signals with the images and redshifts observed in the electromagnetic domain. We demonstrate that just 10 such systems can provide a Hubble constant uncertainty of 0.68% for a flat lambda cold dark matter universe in the era of third-generation ground-based detectors.

  14. Multiple scattering of electromagnetic waves by rain

    Science.gov (United States)

    Tsolakis, A.; Stutzman, W. L.

    1982-01-01

    As the operating frequencies of communications systems move higher into the millimeter wave region, the effects of multiple scattering in precipitation media become more significant. In this paper, general formulations are presented for single, first-order multiple, and complete multiple scattering. Included specifically are distributions of particle size, shape, and orientation angle, as well as variation in the medium density along the direction of wave propagation. Calculations are performed for rain. It is shown that the effects of higher-order scattering are not noticeable in either attenuation or channel isolation on a dual-polarized system until frequencies of about 30 GHz are reached. The complete multiple-scattering formulation presented gives accurate results at high millimeter wave frequencies as well as including realistic medium parameter distributions. Furthermore, it is numerically efficient.

  15. Electromagnetic foundations of solar radiation collection a technology for sustainability

    CERN Document Server

    Sangster, Alan J

    2014-01-01

    This text seeks to illuminate, mainly for the electrical power engineers of the future, the topic of large scale solar flux gathering schemes, which arguably represent the major source of renewable power available. The aim of the content is to impart, from an electromagnetic perspective, a deep and sound understanding of the topic of solar flux collection, ranging from the characteristics of light to the properties of antennas. To do this five chapters are employed to provide a thorough grounding in relevant aspects of electromagnetism and electromagnetic waves including optics, electromagneti

  16. Explosive electromagnetic radiation by the relaxation of a multimode magnon system.

    Science.gov (United States)

    Vasyuchka, V I; Serga, A A; Sandweg, C W; Slobodianiuk, D V; Melkov, G A; Hillebrands, B

    2013-11-01

    Microwave emission from a parametrically pumped ferrimagnetic film of yttrium iron garnet was studied versus the magnon density evolution, which was detected by Brillouin light scattering spectroscopy. It has been found that the shutdown of external microwave pumping leads to an unexpected effect: The conventional monotonic decrease of the population of parametrically injected magnons is accompanied by an explosive behavior of electromagnetic radiation at the magnon frequency. The developed theory shows that this explosion is caused by a nonlinear energy transfer from parametrically driven short-wavelength dipolar-exchange magnons to a long-wavelength dipolar magnon mode effectively coupled to an electromagnetic wave.

  17. Electromagnetic Waves Broadcast by a VCR.

    Science.gov (United States)

    Brown, Michael H.

    1996-01-01

    Presents experiments that use a video cassette recorder (VCR) to demonstrate polarization of radio waves using two dipole antennas and a spark gap transmitter tuned to a frequency of either 60-66 MHz or 66-72 MHz with wavelengths of 5 or 4.3 meters, close to the wavelengths of the original work done by Heinrich Hertz. (JRH)

  18. Success of electromagnetic shock wave lithotripter asmonotherapy ...

    African Journals Online (AJOL)

    Objectives: To evaluate the success of shock wave lithotripsy (SWL) as monotherapy for solitary renalstones larger than 2 cm without ureteral stenting. Hence, if our study result demonstrates acceptable successand safety, we can recommend ESWL as a treatment option for patients with large renal calculi. Subjects and ...

  19. The combined method for uncertainty evaluation in electromagnetic radiation measurement

    Directory of Open Access Journals (Sweden)

    Kovačević Aleksandar M.

    2014-01-01

    Full Text Available Electromagnetic radiation of all frequencies represents one of the most common and fastest growing environmental influence. All populations are now exposed to varying degrees of electromagnetic radiation and the levels will continue to increase as technology advances. An electronic or electrical product should not generate electromagnetic radiation which may impact the environment. In addition, electromagnetic radiation measurement results need to be accompanied by quantitative statements about their accuracy. This is particularly important when decisions about product specifications are taken. This paper presents an uncertainty budget for disturbance power measurements of the equipment as part of electromagnetic radiation. We propose a model which uses a mixed distribution for uncertainty evaluation. The evaluation of the probability density function for the measurand has been done using the Monte Carlo method and a modified least-squares method (combined method. For illustration, this paper presents mixed distributions of two normal distributions, normal and rectangular, respectively. [Projekat Ministarstva nauke Republike Srbije, br. III 43009 i br. 171007

  20. Graphene as a high impedance surface for ultra-wideband electromagnetic waves

    Energy Technology Data Exchange (ETDEWEB)

    Aldrigo, Martino; Costanzo, Alessandra [Department of Electrical, Electronic, and Information Engineering “Guglielmo Marconi” – DEI, University of Bologna, Viale del Risorgimento, 2, 40132 Bologna (Italy); Dragoman, Mircea [National Institute for Research and Development in Microtechnology (IMT), P.O. Box 38-160, 023573 Bucharest (Romania); Dragoman, Daniela [Department of Physics, University of Bucharest, P.O. Box MG-11, 077125 Bucharest (Romania)

    2013-11-14

    The metals are regularly used as reflectors of electromagnetic fields emitted by antennas ranging from microwaves up to THz. To enhance the reflection and thus the gain of the antenna, metallic high impedance surfaces (HIS) are used. HIS is a planar array of continuous metallic periodic cell surfaces able to suppress surface waves, which cause multipath interference and backward radiation in a narrow bandwidth near the cell resonance. Also, the image currents are reduced, and therefore the antenna can be placed near the HIS. We demonstrate that graphene is acting as a HIS surface in a very large bandwidth, from microwave to THz, suppressing the radiation leakages better than a metal.

  1. 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...

  2. Electromagnetic wave scattering from some vegetation samples

    Science.gov (United States)

    Karam, Mostafa A.; Fung, Adrian K.; Antar, Yahia M.

    1988-01-01

    For an incident plane wave, the field inside a thin scatterer (disk and needle) is estimated by the generalized Rayleigh-Gans (GRG) approximation. This leads to a scattering amplitude tensor equal to that obtained via the Rayleigh approximation (dipole term) with a modifying function. For a finite-length cylinder the inner field is estimated by the corresponding field for the same cylinder of infinite lenght. The effects of different approaches in estimating the field inside the scatterer on the backscattering cross section are illustrated numerically for a circular disk, a needle, and a finite-length cylinder as a function of the wave number and the incidence angle. Finally, the modeling predictions are compared with measurements.

  3. Selective wave-transmitting electromagnetic absorber through composite metasurface

    Science.gov (United States)

    Sun, Zhiwei; Zhao, Junming; Zhu, Bo; Jiang, Tian; Feng, Yijun

    2017-11-01

    Selective wave-transmitting absorbers which have one or more narrow transmission bands inside a wide absorption band are often demanded in wireless communication and radome applications for reducing the coupling between different systems, improving anti-jamming capability, and reducing antennas' radar cross section. Here we propose a feasible method that utilizing composite of two metasurfaces with different polarization dependent characteristics, one works as electromagnetic polarization rotator and the other as a wideband polarization dependent electromagnetic wave absorber. The polarization rotator produces a cross polarization output in the wave-transmitting band, while preserves the polarization of the incidence outside the band. The metasurface absorber works for certain linear polarization with a much wider absorption band covering the wave-transmitting frequency. When combining these two metasurfaces properly, the whole structure behaves as a wideband absorber with a certain frequency transmission window. The proposal may be applied in radome designs to reduce the radar cross section of antenna or improving the electromagnetic compatibility in communication devices.

  4. 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...

  5. Acousto-optic modulation and deflection of terahertz electromagnetic radiation in nonpolar liquids

    Science.gov (United States)

    Nikitin, P. A.; Voloshinov, V. B.; Gerasimov, V. V.; Knyazev, B. A.

    2017-07-01

    The results of a series of experiments on controlled deflection of electromagnetic radiation of a free-electron laser upon diffraction by an acoustic wave in nonpolar liquids are presented. Acoustic and optical properties of liquids that are transparent in the terahertz range are discussed. It is demonstrated that nonpolar liquids may turn out to be a more efficient acousto-optic interaction medium than dielectric crystals or semiconductors.

  6. Magnesiothermic reduction of rice husk ash for electromagnetic wave adsorption

    Science.gov (United States)

    Liu, Shu-Ting; Yan, Kang-kang; Zhang, Yuan hu; Jin, Shi-di; Ye, Ying; Chen, Xue-Gang

    2015-11-01

    The increase in electromagnetic pollution due to the extensive exploitation of electromagnetic (EM) waves in modern technology creates correspondingly urgent need for developing effective EM wave absorbers. In this study, we carried out the magnesiothermic reduced the rice husk ash under different temperatures (400-800 °C) and investigated the electromagnetic wave adsorption of the products. The EM absorbing for all samples are mainly depend on the dielectric loss, which is ascribed to the carbon and silicon carbide content. RA samples (raw rice husk ashed in air and was magesiothermic reduced in different temperatures) exhibit poor dielectric properties, whereas RN samples (raw rice husk ashed in nitrogen and was magesiothermic reduced in different temperatures) with higher content of carbon and silicon carbide display considerable higher dielectric loss values and broader bandwidth for RL<-5 dB and -10 dB. For RN samples, the maximum bandwidth for -5 dB and -10 dB decrease with carbon contents, while the optimum thickness decrease with increasing SiC content. The optimum thickness of RN400-800 for EM absorption is 1.5-2.0 mm, with maximum RL of between -28.9 and -68.4 dB, bandwidth of 6.7-13 GHz for RL<-5 dB and 3.2-6.2 GHz for RL<-10 dB. The magnesiothermic reduction will enhance the potential application of rice husk ash in EM wave absorption and the samples benefited from low bulk density and low thickness. With the advantages of light-weight, high EM wave absorption, low cost, RN400-800 could be promising candidates for light-weight EM wave absorption materials over many conventional EM wave absorbers.

  7. Einstein's coefficients and the wave-particle duality in the theory of thermal radiation

    OpenAIRE

    Prigara, Fedor V.

    2005-01-01

    It is shown that the concept of elementary resonator in the theory of thermal radiation implies the indivisible connection between particles (photons) and electromagnetic waves. This wave-particle duality covers both the Wien and Rayleigh-Jeans regions of spectrum.

  8. The involvement of cutaneous receptors in the biological effects of electromagnetic millimeter waves

    Directory of Open Access Journals (Sweden)

    Anton Emil

    2014-01-01

    Full Text Available The involvement of peripheral nerve terminations in the mechanisms of action of electromagnetic millimeter waves (mmW was assessed. It is currently thought that mmW could be used in noninvasive complementary therapy because of their analgesic effect. However, the mechanisms of their antinociceptive effect and non-ionizing radiation are the subjects of controversy. The mechanisms of interaction of mmW and the cutaneous tissue have not been elucidated. We observed mast cell degranulation at the place of mmW action, a decrease of chronaxie and Turck reflex time, an increase in the number of afferent impulses after sciatic nerve at stimulation, as well as an increase electrocardiogram R-R interval of isolated frog heart after application of mmW. Based on these investigations, we propose that electromagnetic waves of millimeter length modify, through indirect mechanisms, the excitability and reactivity of peripheral nerve terminations.

  9. Electromagnetic wave scattering on imperfect cloaking devices

    Directory of Open Access Journals (Sweden)

    Isić G.

    2008-01-01

    Full Text Available Cloaking devices based on the coordinate transform approach enable, in principle, a perfect concealment of a region in space provided that the material composing the cloaking shell meets certain criteria. To achieve ideal cloaking it is necessary that the shell material parameters have singular values on the surface bounding the cloaked region which is unphysical. In this paper we assume finite values of cloak parameters and apply the scattering theory formalism to give an estimate of the overall performance of an 'imperfect' cloak. We perform full-wave numerical calculations and use our theoretical results to discuss them.

  10. Electromagnetic radiation influence on clinical course of experimental wound infection

    Directory of Open Access Journals (Sweden)

    Pronina Е.А.

    2010-09-01

    Full Text Available The article gives close attention to the study of electromagnetic radiation influence (EMR at the frequency of molecular spectrum absorption and radiation (MSAR of nitric oxide (150 GHz and atmospheric oxygen (129 GHz on the clinical course of experimental wound infection caused by antibiotic-sensitive and antibiotic-resistant strains of Pseudomonas aeruginosa. The panoramic spectrometric measuring complex, developed in Saratov Scientific Research Institute of Measuring Equipment was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the atmospheric oxygen and nitric oxide absorption and radiation molecular spectrum structure. The experiments proved the fact that exposure to radiation at the frequency of molecular spectrum absorption and radiation (MSAR of nitric oxide and atmospheric oxygen had positive impact on the course of traumatic process

  11. Electromagnetic wave propagation and wave-vector diagram in space-time periodic media.

    Science.gov (United States)

    Elachi, C.

    1972-01-01

    Analysis of TE and TM wave propagation in space-time periodic media such as dielectrics, isotropic plasmas and uniaxial plasmas. A numerical solution is obtained for media with sinusoidal periodicity. Wave-vector diagrams are plotted to facilitate studies of dipole radiation, wave propagation in waveguides and wave interactions with a half-space.

  12. electromagnetic radiation exposure from cellular base station

    African Journals Online (AJOL)

    eobe

    to human health from exposure to radio frequency. (RF) electromagnetic fields ... adverse health effects such as blood brain barrier, cancer and sleep ... restrictions set by ICNIRP as shown in Table 1 [20]. Table 1: Basic restrictions between 10 and 300 GHz. Exposure characteristics. Power density (. 2. /. mW ). Occupational ...

  13. Luminous phenomena and electromagnetic VHF wave emission originated from earthquake-related radon exhalation

    Science.gov (United States)

    Seki, A.; Tobo, I.; Omori, Y.; Muto, J.; Nagahama, H.

    2013-12-01

    's rotation-rotation transition causes electromagnetic VHF wave emission. We also discuss a possibility of electromagnetic VHF wave emission from excitation of polyatomic molecules by alpha particles from Rn-222 and its daughter nuclides, similar to air luminescence by excitation of nitrogen molecule in the viewpoint of electromagnetic radiation in quantum theory.

  14. Study of electromagnetic radiation pollution in Jalandhar city, India

    Science.gov (United States)

    Basandrai, D.; Dhami, A. K.; Bedi, R. K.; Khan, S. A.

    2017-07-01

    Environment pollution from electromagnetic radiations emitted from cell phone towers is a new kind of health hazard, which has increase the public concern regarding the health implications of electromagnetic radiations on humans and animals. Long term consequences of these radiations are still unknown. So it become important to measure and maps the electromagnetic radiation level to analyze potential risk. The present study has been taken to estimate the RF pollution by measuring radiation power densities level near school, hospitals and old age home of Jalandhar City, India. The radiation exposure was measured using a handheld portable electrosmog meter. Results were compared with the safety guidelines issued by ICNIRP (International commission on non ionizing radiation protection) and Bio-initiative report, 2012. It has been found that the radiation exposure level in terms of power densities and corresponding specific absorption rate (SAR) are much below than ICNIRP guidelines for all schools, hospitals and old age home. But in the case of 3 schools, the results are quite alarming where the power density and SAR was found to be 79.6% and 4%, respectively higher in comparisons with safe biological limit.

  15. Transition operators in electromagnetic-wave diffraction theory. II - Applications to optics

    Science.gov (United States)

    Hahne, G. E.

    1993-01-01

    The theory developed by Hahne (1992) for the diffraction of time-harmonic electromagnetic waves from fixed obstacles is briefly summarized and extended. Applications of the theory are considered which comprise, first, a spherical harmonic expansion of the so-called radiation impedance operator in the theory, for a spherical surface, and second, a reconsideration of familiar short-wavelength approximation from the new standpoint, including a derivation of the so-called physical optics method on the basis of quasi-planar approximation to the radiation impedance operator, augmented by the method of stationary phase. The latter includes a rederivation of the geometrical optics approximation for the complete Green's function for the electromagnetic field in the presence of a smooth- and a convex-surfaced perfectly electrically conductive obstacle.

  16. 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.

  17. Non-Thermal Electromagnetic Radiation Damage to Lens Epithelium

    OpenAIRE

    Bormusov, Elvira; P.Andley, Usha; Sharon, Naomi; Sch?chter, Levi; Lahav, Assaf; Dovrat, Ahuva

    2008-01-01

    High frequency microwave electromagnetic radiation from mobile phones and other modern devices has the potential to damage eye tissues, but its effect on the lens epithelium is unknown at present. The objective of this study was to investigate the non-thermal effects of high frequency microwave electromagnetic radiation (1.1GHz, 2.22 mW) on the eye lens epithelium in situ. Bovine lenses were incubated in organ culture at 35?C for 10-15 days. A novel computer-controlled microwave source was us...

  18. Highly efficient proteolysis accelerated by electromagnetic waves for Peptide mapping.

    Science.gov (United States)

    Chen, Qiwen; Liu, Ting; Chen, Gang

    2011-09-01

    Proteomics will contribute greatly to the understanding of gene functions in the post-genomic era. In proteome research, protein digestion is a key procedure prior to mass spectrometry identification. During the past decade, a variety of electromagnetic waves have been employed to accelerate proteolysis. This review focuses on the recent advances and the key strategies of these novel proteolysis approaches for digesting and identifying proteins. The subjects covered include microwave-accelerated protein digestion, infrared-assisted proteolysis, ultraviolet-enhanced protein digestion, laser-assisted proteolysis, and future prospects. It is expected that these novel proteolysis strategies accelerated by various electromagnetic waves will become powerful tools in proteome research and will find wide applications in high throughput protein digestion and identification.

  19. Controlling Gigahertz and Terahertz Surface Electromagnetic Waves with Metamaterial Resonators

    Directory of Open Access Journals (Sweden)

    W.-C. Chen

    2011-12-01

    Full Text Available We computationally and experimentally investigate the use of metamaterial resonators as bandpass filters and other components that enable control of guided surface electromagnetic waves. The guided surface electromagnetic wave propagates on a planar Goubau line, launched via a coplanar waveguide coupler with 50Ω impedance. Experimental samples targeted for either microwave or terahertz frequencies are measured and shown to be in excellent agreement with simulations. Metamaterial elements are designed to absorb energy only of the planar Goubau line and yield narrow-band resonances with relatively high quality factors. Two independent configurations of coupled metamaterial elements are demonstrated that modify the otherwise flat transmission spectrum of the planar Goubau line. By physically shunting the capacitive gaps of the coupled metamaterial elements, we demonstrate the potential for a large dynamic range in transmissivity, suggesting the use of this configuration for high-bandwidth terahertz communications.

  20. Electromagnetic radiation in a medium with a velocity gradient

    Science.gov (United States)

    Gladyshev, V. O.; Tereshin, A. A.; Bazleva, D. D.

    2016-04-01

    A relativistic expression has been obtained for the curvature of trajectory of the wave vector of an electromagnetic wave in a moving optically transparent medium. It has been shown that the curvature of the trajectory and angular deviation of rays appear in a homogeneous isotropic medium if the gradient of the velocity field in the medium is nonzero. The bending of the trajectory in the medium with the velocity gradient is a firstorder effect in the ratio u/ c.

  1. Detecting electromagnetic cloaks using backward-propagating waves

    KAUST Repository

    Salem, Mohamed

    2011-08-01

    A novel approach for detecting transformation-optics invisibility cloaks is proposed. The detection method takes advantage of the unusual backward-propagation characteristics of recently reported beams and pulses to induce electromagnetic scattering from the cloak. Even though waves with backward-propagating energy flux cannot penetrate the cloaking shell and interact with the cloaked objects (i.e., they do not make the cloaked object visible), they provide a mechanism for detecting the presence of cloaks. © 2011 IEEE.

  2. Paraxial theory of electromagnetic waves in plane inhomogeneous media.

    Science.gov (United States)

    Hacyan, Shahen

    2010-09-01

    The problem of electromagnetic waves propagating in inhomogeneous media is formulated within the paraxial approximation. The analysis is restricted to a medium with a plane and smooth inhomogeneity. The general form of a Gaussian beam is obtained in terms of the permittivity and permeability of the medium. Particular attention is paid to the case of internal reflection, where a short-wavelength approximation breaks down; a possible treatment of the problem is proposed. A simple model is worked out to illustrate the formalism.

  3. Electromagnetic waves in a model with Chern-Simons potential.

    Science.gov (United States)

    Pis'mak, D Yu; Pis'mak, Yu M; Wegner, F J

    2015-07-01

    We investigated the appearance of Chern-Simons terms in electrodynamics at the surface or interface of materials. The requirement of locality, gauge invariance, and renormalizability in this model is imposed. Scattering and reflection of electromagnetic waves in three different homogeneous layers of media is determined. Snell's law is preserved. However, the transmission and reflection coefficient depend on the strength of the Chern-Simons interaction (connected with Hall conductance), and parallel and perpendicular components are mixed.

  4. Mathematical models for dispersive electromagnetic waves: An overview

    OpenAIRE

    Cassier, Maxence; Joly, Patrick; Kachanovska, Maryna

    2017-01-01

    International audience; In this work, we investigate mathematical models for electromagnetic wave propagation in dispersive isotropic media. We emphasize the link between physical requirements and mathematical properties of the models. A particular attention is devoted to the notion of non-dissipativity and passivity. We consider successively the case of so-called local media and general passive media. The models are studied through energy techniques, spectral theory and dispersion analysis o...

  5. Diffraction of electromagnetic waves by a rectangular wedge structure

    Science.gov (United States)

    Makarov, G. I.; Sozonov, A. P.

    A theoretical problem of electromagnetic wave diffraction in a system of two rectangular wedges is examined: a perfectly conducting wedge and a wedge with finite relative permittivity, the two wedges having a common face. For the Fourier component of the diffraction field, a shifting Riemann boundary value problem is obtained. This problem is reduced to a convolution-type integral equation for the semiaxis, with the kernel taking the form of the sum of the difference and regular kernels.

  6. Stimulated electromagnetic emission polarization under different polarizations of pump waves

    OpenAIRE

    E. D. Tereshchenko; R. Y. Yurik; Baddeley, L.

    2015-01-01

    The results of investigations into the stimulated electromagnetic emission (SEE) polarization under different modes of the pump wave polarization are presented. The present results were obtained in November 2012 during a heating campaign utilizing the SPEAR (Space Plasma Exploration by Active Radar) heating facility, transmitting in both O- and X-mode polarization, and a PGI (Polar Geophysical Institute) radio interferometer capable of recording the polarization of the recei...

  7. Electromagnetic wave extinction within a forested canopy

    Science.gov (United States)

    Karam, M. A.; Fung, A. K.

    1989-01-01

    A forested canopy is modeled by a collection of randomly oriented finite-length cylinders shaded by randomly oriented and distributed disk- or needle-shaped leaves. For a plane wave exciting the forested canopy, the extinction coefficient is formulated in terms of the extinction cross sections (ECSs) in the local frame of each forest component and the Eulerian angles of orientation (used to describe the orientation of each component). The ECSs in the local frame for the finite-length cylinders used to model the branches are obtained by using the forward-scattering theorem. ECSs in the local frame for the disk- and needle-shaped leaves are obtained by the summation of the absorption and scattering cross-sections. The behavior of the extinction coefficients with the incidence angle is investigated numerically for both deciduous and coniferous forest. The dependencies of the extinction coefficients on the orientation of the leaves are illustrated numerically.

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

    Energy Technology Data Exchange (ETDEWEB)

    Castejon, F.; Eguilior, S.

    2003-07-01

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

  9. Reflection and transmission of electromagnetic waves at a temporal boundary.

    Science.gov (United States)

    Xiao, Yuzhe; Maywar, Drew N; Agrawal, Govind P

    2014-02-01

    We consider propagation of an electromagnetic (EM) wave through a dynamic optical medium whose refractive index varies with time. Specifically, we focus on the reflection and transmission of EM waves from a temporal boundary and clarify the two different physical processes that contribute to them. One process is related to impedance mismatch, while the other results from temporal scaling related to a sudden change in the speed of light at the temporal boundary. Our results show that temporal scaling of the electric field must be considered for light propagation in dynamic media. Numerical solutions of Maxwell's equations are in full agreement with our theory.

  10. Spin-electromagnetic waves in planar multiferroic multilayers

    Science.gov (United States)

    Nikitin, Andrey A.; Ustinov, Alexey B.; Vitko, Vitalii V.; Nikitin, Alexey A.; Kondrahov, Alexandr V.; Pirro, P.; Lähderanta, E.; Kalinikos, Boris A.; Hillebrands, B.

    2017-07-01

    A general electrodynamic theory is developed for dispersion characteristics of spin-electromagnetic waves (SEWs) propagating in multiferroic multilayers. The derivation is based on the full set of Maxwell's equations taking into account retardation effects. The multilayers are considered to be composed of an infinite number of ferrite and ferroelectric layers having arbitrary thicknesses, as well as arbitrary magnetic and electric parameters. As an example, spectra of SEWs are calculated and analyzed for a heterostructure containing two thin ferrite films separated by a thin ferroelectric film. An electric field tunability of the SEW dispersion characteristics at gigahertz frequencies is shown, providing an efficient control of SEW wave-numbers important for applications.

  11. Influence of electromagnetic SHF-waves on motility of tubifex

    Directory of Open Access Journals (Sweden)

    I. K. Smolyarenko

    2005-02-01

    Full Text Available We investigated influence of electromagnetic superhigh frequency (SHF waves (10 hHz on mechanical parameters of motility of bunch tubifex (1300 - 1500 units at a different load and sequence of its mechanical stimulation. Is shown, that after a пот-thermal waveirradiation (1 MVt/sm2 latency and forward front of mechanograms is increased on 5 - 10 %, amplitude and duration of the answers simultaneously decreases. The maximal mass, which can lift single unit tubifex is decreased. The capacity of single unit is reduced on the average about 80 %. The authors make conclusion about temporary negative influence SHF-waves on simple biological systems.

  12. Chorus Wave Modulation of Langmuir Waves in the Radiation Belts

    Science.gov (United States)

    Li, Jinxing; Bortnik, Jacob; An, Xin; Li, Wen; Thorne, Richard M.; Zhou, Meng; Kurth, William S.; Hospodarsky, George B.; Funsten, Herbert O.; Spence, Harlan E.

    2017-12-01

    Using high-resolution waveforms measured by the Van Allen Probes, we report a novel observation in the radiation belts. Namely, we show that multiband, discrete, rising-tone whistler mode chorus emissions exhibit a one-to-one correlation with Langmuir wave bursts. Moreover, the periodic Langmuir wave bursts are generally observed at the phase location where the chorus wave E|| component is oriented opposite to its propagation direction. The electron measurements show a beam in phase space density at the particle velocity that matches the parallel phase velocity of the chorus waves. Based on this evidence, we conclude that the chorus waves accelerate the suprathermal electrons via Landau resonance and generate a localized electron beam in phase space density. Consequently, the Langmuir waves are excited locally and are modulated by the chorus wave phase. This microscale interaction between chorus waves and high-frequency electrostatic waves provides a new insight into the nonlinear wave-particle interaction process.

  13. Modeling and design for electromagnetic surface wave devices

    Science.gov (United States)

    La Spada, Luigi; Haq, Sajad; Hao, Yang

    2017-09-01

    A great deal of interest has reemerged recently in the study of surface waves. The possibility to control and manipulate electromagnetic wave propagations at will opens many new research areas and leads to lots of novel applications in engineering. In this paper, we will present a comprehensive modeling and design approach for surface wave cloaks, based on graded-refractive-index materials and the theory of transformation optics. It can be also applied to any other forms of surface wave manipulation, in terms of amplitude and phase. In this paper, we will present a general method to illustrate how this can be achieved from modeling to the final design. The proposed approach is validated to be versatile and allows ease in manufacturing, thereby demonstrating great potential for practical applications.

  14. Non-thermal electromagnetic radiation damage to lens epithelium.

    Science.gov (United States)

    Bormusov, Elvira; P Andley, Usha; Sharon, Naomi; Schächter, Levi; Lahav, Assaf; Dovrat, Ahuva

    2008-05-21

    High frequency microwave electromagnetic radiation from mobile phones and other modern devices has the potential to damage eye tissues, but its effect on the lens epithelium is unknown at present. The objective of this study was to investigate the non-thermal effects of high frequency microwave electromagnetic radiation (1.1GHz, 2.22 mW) on the eye lens epithelium in situ. Bovine lenses were incubated in organ culture at 35°C for 10-15 days. A novel computer-controlled microwave source was used to investigate the effects of microwave radiation on the lenses. 58 lenses were used in this study. The lenses were divided into four groups: (1) Control lenses incubated in organ culture for 10 to15 days. (2) Electromagnetic radiation exposure group treated with 1.1 GHz, 2.22 mW microwave radiation for 90 cycles of 50 minutes irradiation followed by 10 minutes pause and cultured up to 10 days. (3) Electromagnetic radiation exposure group treated as group 2 with 192 cycles of radiation and cultured for 15 days. (4) Lenses exposed to 39.5°C for 2 hours 3 times with 24 hours interval after each treatment beginning on the second day of the culture and cultured for 11 days. During the culture period, lens optical quality was followed daily by a computer-operated scanning laser beam. At the end of the culture period, control and treated lenses were analyzed morphologically and by assessment of the lens epithelial ATPase activity. Exposure to 1.1 GHz, 2.22 mW microwaves caused a reversible decrease in lens optical quality accompanied by irreversible morphological and biochemical damage to the lens epithelial cell layer. The effect of the electromagnetic radiation on the lens epithelium was remarkably different from those of conductive heat. The results of this investigation showed that electromagnetic fields from microwave radiation have a negative impact on the eye lens. The lens damage by electromagnetic fields was distinctly different from that caused by conductive heat.

  15. Obliquely Propagating Electromagnetic Waves in Magnetized Kappa Plasmas

    Science.gov (United States)

    Gaelzer, R.

    2015-12-01

    The effects of velocity distribution functions (VDFs) that exhibit a power-law dependence on the high-energy tail have been the subjectof intense research by the space plasma community. Such functions, known as kappa or superthermal distributions, have beenfound to provide a better fitting to the VDF measured by spacecraft in the solar wind. One of the problems that is being addressed on this new light is the temperature anisotropy of solar wind protons and electrons. An anisotropic kappa VDF contains a large amount of free energy that can excite waves in the solar wind. Conversely, the wave-particle interaction is important to determine the shape of theobserved particle distributions.In the literature, the general treatment for waves excited by (bi-)Maxwellian plasmas is well-established. However, for kappa distributions, either isotropic or anisotropic, the wave characteristics have been studied mostly for the limiting cases of purely parallel or perpendicular propagation. Contributions for the general case of obliquely-propagating electromagnetic waves have been scarcely reported so far. The absence of a general treatment prevents a complete analysis of the wave-particle interaction in kappa plasmas, since some instabilities, such as the firehose, can operate simultaneously both in the parallel and oblique directions.In a recent work [1], we have obtained expressions for the dielectric tensor and dispersion relations for the low-frequency, quasi-perpendicular dispersive Alfvén waves resulting from a kappa VDF. In the present work, we generalize the formalism introduced by [1] for the general case of electrostatic and/or electromagnetic waves propagating in a kappa plasma in any frequency range and for arbitrary angles.We employ an isotropic distribution, but the methods used here can be easily applied to more general anisotropic distributions,such as the bi-kappa or product-bi-kappa. [1] R. Gaelzer and L. F. Ziebell, Journal of Geophysical Research 119, 9334

  16. Descriptive Study of Electromagnetic Wave Distribution for Various Seating Positions: Using Digital Textbooks

    Science.gov (United States)

    Seomun, GyeongAe; Kim, YoungHwan; Lee, Jung-Ah; Jeong, KwangHoon; Park, Seon-A; Kim, Miran; Noh, Wonjung

    2014-01-01

    To better understand environmental electromagnetic wave exposure during the use of digital textbooks by elementary school students, we measured numeric values of the electromagnetic fields produced by tablet personal computers (TPCs). Specifically, we examined the distribution of the electromagnetic waves for various students' seating positions in…

  17. A STUDY OF NONLINEAR PHENOMENA IN THE PROPAGATION OF ELECTROMAGNETIC WAVES IN A WEAKLY IONIZED GAS.

    Science.gov (United States)

    This paper is a study of nonlinear phenomena in the propagation of electromagnetic waves in a weakly ionized gas externally biased with a magneto...static field. The present study is restricted to the nonlinear phenomena arising from the interaction of electromagnetic waves in the ionized gas. The...the propagation of electromagnetic waves in the ionized gas, and also on the reflection of waves from an ionized gas semi-infinite extent. (Author)

  18. Electron States and Quasienergy Spectrum of the Graphene Exposed to the Electromagnetic Wave

    OpenAIRE

    S.V. Kryuchkov; E.I. Kukhar’; O.S. Nikitina

    2013-01-01

    The effective spectrum and wave functions of electron states in graphene under the electromagnetic wave with circular polarization are found. The band gap in the graphene spectrum induced by the electromagnetic wave is calculated. Occurrence of such gap is shown to have the nature of the parametric resonance. The effective energy of the electron state in graphene is proved to be the energy averaged over the period of the electromagnetic wave.

  19. Early electromagnetic waves from earthquake rupturing: I. theoretical formulations

    Science.gov (United States)

    Gao, Yongxin; Chen, Xiaofei; Hu, Hengshan; Zhang, Jie

    2013-03-01

    Earthquake taking place in a fluid-saturated porous medium can generate electromagnetic (EM) waves because of the electrokinetic effect. These generated EM waves arrive at a distant observatory much earlier than the seismic waves because their velocities are much faster than those of the seismic waves. They may explain the early EM signals which have been detected before the detection of the seismic waves after the occurrences of earthquakes. In this study, we attempt to analyse such a kind of early EM signals induced by an earthquake because of the electrokinetic effect. The earthquake is assumed to be a fault slip and is modelled by a moment tensor point source. With Pride's equations quantifying the coupling between seismic and EM waves, we first present a real-axis integration (RAI) algorithm to calculate the seismoelectric wavefields in a layered porous formation. Although full waveforms can be calculated by such a RAI technique, individual waves cannot be easily separated from the full waveforms. The need to compute the individual waves is eminent for the purpose of investigating the early EM waves, because these EM waves are usually several orders weaker than and are masked by the EM signals accompanying the seismic waves in the full waveforms. Therefore, we further develop a branch-cut integration (BCI) algorithm, by transforming the original wavenumber integral along the real axis in the complex wavenumber plane for the RAI technique to a sum of integrals along the vertical branch cuts and the residues of the poles. For performing the integrations along the vertical branch cuts, determination of the Riemann sheets are explained and displayed. Finally, the seismoelectric wavefields are represented in forms allowing calculating individual waves.

  20. The scattering of electromagnetic waves from turbulent plasmas

    Science.gov (United States)

    Ram, A. K.; Hizanidis, K.

    2017-10-01

    In fusion devices, radio frequency (RF) electromagnetic waves encounter turbulent plasmas along their path from the excitation structures to the core of the plasma. In order to optimize heating and current drive by the RF waves, it is necessary to understand the effect of the density turbulence on the propagation characteristics of the waves. A common approach towards quantifying the effects of turbulence is the Kirchhoff technique. Here the wave fields and their normal derivatives are evaluated at a surface separating two different densities using physical optics. The fields at any point on this surface are approximated to be the same as the fields on a tangent plane at that point. Using the Kirchhoff technique, we show that turbulence can lead to changes in the propagation vector and polarization of the waves, side-scattering, and coupling between different plasma waves. This affects the spatial uniformity of power flow into the plasma. Full wave analytical calculations and numerical simulations confirm these physical results. The theory applies to all RF waves, irrespective of their frequency, and allows for arbitrary plasma density variations. Supported by DoE Grant DE-FG02-91ER-54109 and in part by the Hellenic National Programme on Controlled Thermonuclear Fusion associated with the EUROfusion Consortium.

  1. Human Health and Exposure to Electromagnetic Radiation

    Science.gov (United States)

    1992-07-01

    expected that the basis for extrapolation will be refined in future as interactions of electromagnetic fields with the body are better quantified and an...control study of male physiotherapists who may have used shortwave, microwave, infrared and acoustic equipment for therapeutic purposes indicated no...study of female physiotherapists who gave birth to children with malformations suggested that the number of ,.ch children was higher among those who

  2. Radio Frequency Electromagnetic Radiation From Streamer Collisions.

    Science.gov (United States)

    Luque, Alejandro

    2017-10-16

    We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

  3. Radio Frequency Electromagnetic Radiation From Streamer Collisions

    Science.gov (United States)

    Luque, Alejandro

    2017-10-01

    We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

  4. Current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation

    National Research Council Canada - National Science Library

    N Hatefi Kargan

    2013-01-01

     In this paper, current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation has been calculated and compared with the results when there is no electromagnetic radiation...

  5. Electromagnetic Radiation Measurements and Safety Issues of some Cellular

    Directory of Open Access Journals (Sweden)

    A. Mousa

    2011-01-01

    Full Text Available As the mobile telecommunication systems are tremendously growing allover the world then the numbers of handheld andbase stations are also rapidly growing and it became very popular to see these base stations distributed everywhere in theneighborhood and on roof tops which has caused a considerable amount of panic to the public in Palestine concerning witherthe radiated electromagnetic field from these base stations may cause any health effect or hazard. This paper focuses on theradiated electromagnetic energy from some typical mobile base stations around the city of Nablus. The exposure levels dueto these stations were measured and compared to some international standard guidelines like ICNIRP and FCC to see if itmeets these standards, this is in order to answer some of the public fear and concern. The results are presented and somecomments are made on the other sources of electromagnetic radiation in the 200 kHz to 3 GHz range.

  6. 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...

  7. Electromagnetic Radiation Exposure from Cellular Base Station: A ...

    African Journals Online (AJOL)

    For cellular network Base Transceiver Station (BTS) antennas to operate as intended without adverse health effects, they must comply with Electromagnetic Compatibility (EMC) standards as well as safety guidelines relating to exposure of non-ionizing radiation. Global System for Mobile Communication (GSM) operators ...

  8. 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.

  9. Parametric instabilities of circularly polarized large-amplitude dispersive Alfven waves: excitation of parallel-propagating electromagnetic daughter waves

    Energy Technology Data Exchange (ETDEWEB)

    Vinas, A.F.; Goldstein, M.L. (National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center)

    1991-08-01

    The parametric decay and modulational instabilities of a large-amplitude circularly polarized dispersive Alfven wave are investigated. The treatment is more general than that of previous derivations based on the two-fluid equations in that allowance is made for propagation of the unstable daughter waves at arbitrary angles to the background magnetic field, although the main concern is the exploration of new aspects of propagation parallel to the DC magnetic field. In addition to the well-known coupling of pump waves to electrostatic daughter waves, a new parametric channel is found where the pump wave couples directly to electromagnetic daughter waves. The growth rate of the electromagnetic instability increases monotonically with increasing pump wave amplitude. Analysis confirms that, for decay, the dominant process is coupling to electrostatic daughter waves, at least for parallel propagation. For modulation, the coupling to electromagnetic daughter waves usually dominates, suggesting that the parametric modulational instability is really an electromagnetic phenomena. (author).

  10. Some consequences of intense electromagnetic wave injection into space plasmas

    Science.gov (United States)

    Burke, William J.; Rothwell, Paul L.; Rothwell, Paul L.; Rothwell, Paul L.

    1986-01-01

    The future possibility of actively testing the current understanding of how energetic particles may be accelerated in space or dumped from the radiation belts using intense electromagnetic energy from ground based antennas is discussed. The ground source of radiation is merely a convenience. A space station source for radiation that does not have to pass through the atmosphere and lower ionosphere, is an attractive alternative. The text is divided into two main sections addressing the possibilities of: (1) accelerating electrons to fill selected flux tubes above the Kennel-Petscheck limit for stably trapped fluxes, and (2) using an Alfven maser to cause rapid depletion of energetic protons or electrons from the radiation belts.

  11. Electromagnetic Cyclotron Waves in the Solar Wind: Wind Observation and Wave Dispersion Analysis

    Science.gov (United States)

    Jian, L. K.; Moya, P. S.; Vinas, A. F.; Stevens, M.

    2016-01-01

    Wind observed long-lasting electromagnetic cyclotron waves near the proton cyclotron frequency on 11 March 2005, in the descending part of a fast wind stream. Bi-Maxwellian velocity distributions are fitted for core protons, beam protons, and alpha-particles. Using the fitted plasma parameters we conduct kinetic linear dispersion analysis and find ion cyclotron and/or firehose instabilities grow in six of 10 wave intervals. After Doppler shift, some of the waves have frequency and polarization consistent with observation, thus may be correspondence to the cyclotron waves observed.

  12. Propagation of electromagnetic waves in stochastic helical media.

    Science.gov (United States)

    Mendez, David; Reyes, J Adrian

    2012-09-01

    We have developed a model for studying the axial propagation of elliptically polarized electromagnetic waves in a spatially random helical media. We start by writing Maxwell equations for a structurally chiral medium whose dielectric permittivities, polar, and helical angles contain both a stochastic contribution and a deterministic one. We write the electromagnetic equations into a Marcuvitz-Schwigner representation to transform them afterward in a simpler expression by using the Oseen transformation. We exhibit that in the Oseen frame the Marcuvitz-Schwigner equations turns out to be a linear vector stochastic system of differential equations with multiplicative noise. Applying to the resulting equation a formalism for treating stochastic differential equations, we find the governing equations for the first moments of the electromagnetic field amplitudes for a general autocorrelation function for the system diffractive indexes, and calculate their corresponding band structure for a particular spectral noise density. We have shown that the average resulting electromagnetic fields exhibit a decaying exponential dependence which stems from by dissipation and the presence of qualitative modifications in the band structure including a considerable widening of the band gap and the existence of new local maxima for the modes without a band gap.

  13. Scattering of electromagnetic waves from a randomly perturbed quasiperiodic surface

    Science.gov (United States)

    Shin, R. T.; Kong, J. A.

    1984-01-01

    Electromagnetic-wave scattering by a quasi-periodic surface with random perturbations (as in the remote sensing of plowed fields) is investigated analytically, applying the Kirchhoff approximation and modeling the plowed fields by means of Gaussian random variation, sinusoidal variation, and Gaussian random variation about the spatial frequency. Coherent and incoherent bistatic scattering coefficients are derived in closed form by evaluating the physical-optics integral and shown to be proportional, in the geometric-optics limit, to the occurrence probability of slopes which reflect the incident wave specularly in the direction of the scattered wave. Backscattering cross sections are plotted as functions of incidence angle for a number of cases, demonstrating the strong effect of row direction.

  14. Explaining Electromagnetic Plane Waves in a Vacuum at the Introductory Level

    Science.gov (United States)

    Allred, Clark L.; Della-Rose, Devin J.; Flusche, Brian M.; Kiziah, Rex R.; Lee, David J.

    2010-01-01

    A typical introduction to electromagnetic waves in vacuum is illustrated by the following quote from an introductory physics text: "Maxwell's equations predict that an electromagnetic wave consists of oscillating electric and magnetic fields. The changing fields induce each other, which maintains the propagation of the wave; a changing electric…

  15. Surface waves in three-dimensional electromagnetic composites and their effect on homogenization.

    Science.gov (United States)

    Xiong, Xiaoyan Y Z; Jiang, Li Jun; Markel, Vadim A; Tsukerman, Igor

    2013-05-06

    Reflection and transmission of electromagnetic waves at the boundaries of periodic composites (electromagnetic/optical metamaterials) depends in general on both bulk and surface waves. We investigate the interplay of these two contributions using three-dimensional full-wave numerical simulations and a recently developed non-asymptotic homogenization theory.

  16. Massively sub-wavelength guiding of electromagnetic waves.

    Science.gov (United States)

    Hooper, I R; Tremain, B; Dockrey, J A; Hibbins, A P

    2014-12-16

    Recently a new form of ultra-thin flexible waveguide consisting of a conducting comb-like structure with a thickness of the order of 1/600(th) of the operating wavelength was presented. However, whilst the thickness of the guide was massively sub-wavelength, the remaining dimensions (the height and period of the comb) were much longer. In this paper we propose, and experimentally verify, that a modified guiding geometry consisting of a chain of ultra-thin conducting spirals allows guiding of electromagnetic waves with wavelengths that are many times (40+) longer than any characteristic dimension of the guide, enabling super-sub-wavelength guiding and localisation of electromagnetic energy.

  17. Total absorption of electromagnetic waves in ultimately thin layers

    CERN Document Server

    Ra'di, Younes; Tretyakov, Sergei A

    2012-01-01

    We consider single-layer arrays of electrically small lossy bi-anisotropic particles that completely absorb electromagnetic waves at normal incidence. Required conditions for electromagnetic properties of bi-anisotropic particles have been identified in the most general case of uniaxial reciprocal and nonreciprocal particles. We consider the design possibilities offered by the particles of all four fundamental classes of bianisotropic inclusions: reciprocal chiral and omega particles and nonreciprocal Tellegen and moving particles. We also study the reflection/transmission properties of asymmetric structures with different properties when illuminated from the opposite sides of the sheet. It has been found that it is possible to realize single-layer grids which exhibit the total absorption property when illuminated from one side but are totally transparent when illuminated from the other side (an ultimately thin isolator). Other possible properties are co-polarized or twist polarized reflection from the side o...

  18. Observation of terahertz radiation coherently generated by acoustic waves

    Science.gov (United States)

    Armstrong, Michael R.; Reed, Evan J.; Kim, Ki-Yong; Glownia, James H.; Howard, William M.; Piner, Edwin L.; Roberts, John C.

    2009-04-01

    Over the past decade, pioneering and innovative experiments using subpicosecond lasers have demonstrated the generation and detection of acoustic and shock waves in materials with terahertz frequencies, the highest possible frequency acoustic waves. In addition to groundbreaking demonstrations of acoustic solitons, these experiments have led to new techniques for probing the structure of thin films. Terahertz-frequency electromagnetic radiation has been used in applications as diverse as molecular and material excitations, charge transfer, imaging and plasma dynamics. However, at present, existing approaches to detect and measure the time dependence of terahertz-frequency strain waves in materials use direct optical probes-time-resolved interferometry or reflectrometry. Piezoelectric-based strain gauges have been used in acoustic shock and strain wave experiments for decades, but the time resolution of such devices is limited to ~100ps and slower, the timescale of electronic recording technology. We have recently predicted that terahertz-frequency acoustic waves can be detected by observing terahertz radiation emitted when the acoustic wave propagates past an interface between materials of differing piezoelectric coefficients. Here, we report the first experimental observation of this fundamentally new phenomenon and demonstrate that it can be used to probe structural properties of thin films.

  19. Electromagnetic radiation due to nonlinear oscillations of a charged drop

    Science.gov (United States)

    Shiryaeva, S. O.; Grigor'ev, A. N.; Kolbneva, N. Yu.

    2016-03-01

    The nonlinear oscillations of a spherical charged drop are asymptotically analyzed under the conditions of a multimode initial deformation of its equilibrium shape. It is found that if the spectrum of initially excited modes contains two adjacent modes, the translation mode of oscillations is excited among others. In this case, the center of the drop's charge oscillates about the equilibrium position, generating a dipole electromagnetic radiation. It is shown that the intensity of this radiation is many orders of magnitude higher than the intensity of the drop's radiation, which arises in calculations of the first order of smallness and is related to the drop's charged surface oscillations.

  20. Cancer and electromagnetic radiation therapy: Quo Vadis?

    CERN Document Server

    Makropoulou, Mersini

    2016-01-01

    In oncology, treating cancer with a beam of photons is a well established therapeutic technique, developed over 100 years, and today over 50% of cancer patients will undergo traditional X-ray radiotherapy. However, ionizing radiation therapy is not the only option, as the high-energy photons delivering their cell-killing radiation energy into cancerous tumor can lead to significant damage to healthy tissues surrounding the tumor, located throughout the beam's path. Therefore, in nowadays, advances in ionizing radiation therapy are competitive to non-ionizing ones, as for example the laser light based therapy, resulting in a synergism that has revolutionized medicine. The use of non-invasive or minimally invasive (e.g. through flexible endoscopes) therapeutic procedures in the management of patients represents a very interesting treatment option. Moreover, as the major breakthrough in cancer management is the individualized patient treatment, new biophotonic techniques, e.g. photo-activated drug carriers, help...

  1. Electromagnetic radiation screening of semiconductor devices for long life applications

    Science.gov (United States)

    Hall, T. C.; Brammer, W. G.

    1972-01-01

    A review is presented of the mechanism of interaction of electromagnetic radiation in various spectral ranges, with various semiconductor device defects. Previous work conducted in this area was analyzed as to its pertinence to the current problem. The task was studied of implementing electromagnetic screening methods in the wavelength region determined to be most effective. Both scanning and flooding type stimulation techniques are discussed. While the scanning technique offers a considerably higher yield of useful information, a preliminary investigation utilizing the flooding approach is first recommended because of the ease of implementation, lower cost and ability to provide go-no-go information in semiconductor screening.

  2. Electrosmog. Effects of electromagnetic radiation. Elektrosmog. Die Wirkung elektromagnetischer Strahlung

    Energy Technology Data Exchange (ETDEWEB)

    Nimtz, G. (Koeln Univ. (Germany)); Maecker, S. (Koeln Univ. (Germany). 2. Physikalisches Inst.)

    1994-01-01

    After a detailed explanation of the structure of electromagnetic fields, the authors discuss the mechanisms of interaction which affect biological systems in dependence of the size and frequency of electromagnetic fields. Natural and technical sources of radiation are discussed, as are the physical and physiological fundamentals from which limiting values and other protective measures are derived. The functions of national and international decision-making authorities are outlined, and addresses are given of public institutions in Germany to whom the reader may refer for further information. (orig./MG)

  3. Study on the electromagnetic radiation characteristics of discharging excimer laser system

    Science.gov (United States)

    Zhao, Duliang; Liang, Xu; Fang, Xiaodong; Wang, Qingsheng

    2016-10-01

    Excimer laser in condition of high voltage, large current and fast discharge will produce strong electromagnetic pulse radiation and electromagnetic interference on the around electrical equipment. The research on characteristics and distribution of excimer laser electromagnetic radiation could provide important basis for electromagnetic shielding and suppressing electromagnetic interference, and further improving the electromagnetic compatibility of system. Firstly, electromagnetic radiation source is analyzed according to the working principle of excimer laser. The key test points of the electromagnetic radiation, hydrogen thyratron, main discharge circuit and laser outlet, are determined by the mechanical structure and the theory of electromagnetic radiation. Secondly, characteristics of electromagnetic field were tested using a near field probe on the key positions of the vertical direction at 20, 50, and 80 cm, respectively. The main radiation frequencies and the radiation field characteristics in the near field are obtained. The experimental results show that the main radiation frequencies distribute in 47, 65, and 130 MHz for electric field and the main radiation frequencies distribute in 34, 100, and 165 MHz for magnetic field. The intensity of electromagnetic field decreases rapidly with the increase of test distance. The higher the frequency increases, the faster the amplitude attenuate. Finally, several electromagnetic interference suppression measurement methods are proposed from the perspective of electromagnetic compatibility according to the test results.

  4. Wave energy budget analysis in the Earth's radiation belts uncovers a missing energy.

    Science.gov (United States)

    Artemyev, A V; Agapitov, O V; Mourenas, D; Krasnoselskikh, V V; Mozer, F S

    2015-05-15

    Whistler-mode emissions are important electromagnetic waves pervasive in the Earth's magnetosphere, where they continuously remove or energize electrons trapped by the geomagnetic field, controlling radiation hazards to satellites and astronauts and the upper-atmosphere ionization or chemical composition. Here, we report an analysis of 10-year Cluster data, statistically evaluating the full wave energy budget in the Earth's magnetosphere, revealing that a significant fraction of the energy corresponds to hitherto generally neglected very oblique waves. Such waves, with 10 times smaller magnetic power than parallel waves, typically have similar total energy. Moreover, they carry up to 80% of the wave energy involved in wave-particle resonant interactions. It implies that electron heating and precipitation into the atmosphere may have been significantly under/over-valued in past studies considering only conventional quasi-parallel waves. Very oblique waves may turn out to be a crucial agent of energy redistribution in the Earth's radiation belts, controlled by solar activity.

  5. Virtual Singular Scattering of Electromagnetic Waves in Transformation Media Concept

    Directory of Open Access Journals (Sweden)

    M. Y. Barabanenkov

    2012-07-01

    Full Text Available If a scatterer and an observation point (receive both approach the so-called near field zone of a source of electromagnetic waves, the scattering process becomes singular one which is mathematically attributed to the spatial singularity of the free space Green function at the origin. Starting from less well known property of left-handed material slab to transfer the singularity of the free space Green function by implementing coordinate transformation, we present a phenomenon of virtual singular scattering of electromagnetic wave on an inhomogeneity located in the volume of left – handed material slab. Virtual singular scattering means that a scatterer is situated only virtually in the near field zone of a source, being, in fact, positioned in the far field zone. Such a situation is realized if a scatterer is embedded into a flat Veselago’s lens and approaches the lens’s inner focus because a slab of Veselago medium produces virtual sources inside and behind the slab and virtual scatterer (as a source of secondary waves from both slab sides. Considering a line-like dielectric scatterer we demonstrate that the scattering efficiency is proportional to product of singular quasistatic parts of two empty space Green functions that means a multiplicative quasistatic singularity of the Green function for a slab of inhomogeneous Veselago medium. We calculate a resonance value of the scattering amplitude in the regime similar to the known Mie resonance scattering.

  6. SCATTERING OF ELECTROMAGNETIC WAVES FROM THE DISTURBANCE CAUSED BY A RAPIDLY MOVING BODY IN PLASMAS,

    Science.gov (United States)

    The scattering of electromagnetic waves by a body moving in a plasma is discussed in detail. General theory covering scattering phenomena is...conditions. The general theory is extended to investigate the following two problems: the scattering of electromagnetic waves from the disturbance caused...by a rapidly moving body in the ionosphere and the scattering of electromagnetic waves from the turbulent wake produuced by a re-entry vehicle. In

  7. Diffraction of Electromagnetic Waves on a Waveguide Joint

    Directory of Open Access Journals (Sweden)

    Malykh Mikhail

    2018-01-01

    Full Text Available In general, the investigation of the electromagnetic field in an inhomogeneous waveguide doesn’t reduce to the study of two independent boundary value problems for the Helmholtz equation. We show how to rewrite the Helmholtz equations in the “Hamiltonian form” to express the connection between these two problems explicitly. The problem of finding monochromatic waves in an arbitrary waveguide is reduced to an infinite system of ordinary differential equations in a properly constructed Hilbert space. The calculations are performed in the computer algebra system Sage.

  8. Broadband unidirectional behavior of electromagnetic waves based on transformation optics.

    Science.gov (United States)

    Zang, XiaoFei; Zhu, YiMing; Ji, XueBin; Chen, Lin; Hu, Qing; Zhuang, SongLin

    2017-01-20

    High directive antennas are fundamental elements for microwave communication and information processing. Here, inspired by the method of transformation optics, we propose and demonstrate a transformation medium to control the transmission path of a point source, resulting in the unidirectional behavior of electromagnetic waves (directional emitter) without any reflectors. The network of inductor-capacitor transmission lines is designed to experimentally realize the transformation medium. Furthermore, the designed device can work in a broadband frequency range. The unidirectional-manner-based device demonstrated in this work will be an important step forward in developing a new type of directive antennas.

  9. 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.

  10. Motivating Non-science Majors: The Technology of Electromagnetic Waves

    Science.gov (United States)

    Henrich, Victor E.

    2018-01-01

    To address the need for physics courses that stimulate non-STEM majors' interest in, and appreciation of, science, the Department of Applied Physics has developed a popular course for Yale College undergraduates, The Technological World, that explains the physics behind technologies that students use every day. The course provides an in-depth development of electromagnetic waves, applying them to technologies as diverse as LCD displays, GPS, fiber optics, CAT scans, LEDs, and stealth aircraft. It utilizes a conventional lecture format, with many in-class demonstrations.

  11. Broadband unidirectional behavior of electromagnetic waves based on transformation optics

    Science.gov (United States)

    Zang, Xiaofei; Zhu, Yiming; Ji, Xuebin; Chen, Lin; Hu, Qing; Zhuang, Songlin

    2017-01-01

    High directive antennas are fundamental elements for microwave communication and information processing. Here, inspired by the method of transformation optics, we propose and demonstrate a transformation medium to control the transmission path of a point source, resulting in the unidirectional behavior of electromagnetic waves (directional emitter) without any reflectors. The network of inductor-capacitor transmission lines is designed to experimentally realize the transformation medium. Furthermore, the designed device can work in a broadband frequency range. The unidirectional-manner-based device demonstrated in this work will be an important step forward in developing a new type of directive antennas.

  12. Electromagnetic form factors of the Δ with D-waves

    Energy Technology Data Exchange (ETDEWEB)

    Ramalho, Gilberto T.F. [CFTP, Institute Superior Tecnico, Lisbon (Portugal); Pena, Maria Teresa [CFTP, Institute Superior Tecnico, Lisbon (Portugal); Gross, Franz L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2010-06-01

    The electromagnetic form factors of the Δ baryon are evaluated within the framework of a covariant spectator quark model, where S and D-states are included in the Δ wave function. We predict all the four Δ multipole form factors: the electric charge GE0, the magnetic dipole GM1, the electric quadrupole GE2 and the magnetic octupole GM3. We compare our predictions with other theoretical calculations. Our results are compatible with the available experimental data and recent lattice QCD data.

  13. Scattering of electromagnetic waves by a traversable wormhole

    Directory of Open Access Journals (Sweden)

    B. Nasr Esfahani

    2005-09-01

    Full Text Available   Replacing the wormhole geometry with an equivalent medium using the perturbation theory of scattering and the Born approximation, we have calculated the differential scattering cross section of electromagnetic waves by a traversable wormhole. It is shown that scattering at long wavelenghts can essentially distinguish wormhole from ordinary scattering object. Some of the zeros of the scattering cross section are determined which can be used for estimating the radius of the throat of wormholes. The known result that in this kind of scattering the linear polarization remains unchanged is verified here.

  14. Wave fields in real media wave propagation in anisotropic, anelastic, porous and electromagnetic media

    CERN Document Server

    Carcione, José M

    2014-01-01

    Authored by the internationally renowned José M. Carcione, Wave Fields in Real Media: Wave Propagation in Anisotropic, Anelastic, Porous and Electromagnetic Media examines the differences between an ideal and a real description of wave propagation, starting with the introduction of relevant stress-strain relations. The combination of this relation and the equations of momentum conservation lead to the equation of motion. The differential formulation is written in terms of memory variables, and Biot's theory is used to describe wave propagation in porous media. For each rheology, a plane-wave analysis is performed in order to understand the physics of wave propagation. This book contains a review of the main direct numerical methods for solving the equation of motion in the time and space domains. The emphasis is on geophysical applications for seismic exploration, but researchers in the fields of earthquake seismology, rock acoustics, and material science - including many branches of acoustics of fluids and ...

  15. Analytic solution for electrons and holes in graphene under electromagnetic radiation: gap appearance and non-linear current effects

    OpenAIRE

    Naumis, Gerardo G.; Lopez-Rodriguez, Francisco J.

    2008-01-01

    We find the exact solution of graphene s carriers under electromagnetic radiation. To obtain such solution, we combine Floquet theory with a trial solution. Then the energy spectrum is obtained without using any approximation. Using such results, we prove that the energy spectrum presents a gap opening which depends on de radiation frequency and electric wave intensity, whereas the current shows a strongly non-linear behaviour.

  16. Scattering of Electromagnetic Waves by Drift Vortex in Plasma

    Science.gov (United States)

    Wang, Dong; Chen, Yinhua; Wang, Ge

    2008-02-01

    In a quasi-two-dimensional model, the scattering of incident ordinary electromagnetic waves by a dipole-electrostatic drift vortex is studied with first-order Born approximation. The distribution of the scattering cross-section and total cross-section are evaluated analytically in different approximate conditions, and the physical interpretations are discussed. When the wavelength of incident wave is much longer than the vortex radius (kia ll 1), it is found that the angle at which the scattering cross-section reaches its maxim depends significantly on the approximation of the parameters of the vortex used. It is also found that the total scattering cross-section has an affinitive relation with the parameters of the plasma, while it is irrelevant to the frequency of the incident wave in a wide range of parameters of the vortex. In a totally different range of parameters when incident wave is in the radar-frequency range (then kia ll 1, the wavelength of incident wave is much shorter than the vortex radius), the numerical procedure is conducted with computer in order to obtain the distribution and the total expression of the scattering cross-section. Then it is found that the total scattering cross-section in the low frequency range is much larger than that in high frequency range, so the scattering is more effective in the low frequency range than in high frequency range.

  17. Nearly non-scattering electromagnetic wave set and its application

    Science.gov (United States)

    Liu, Hongyu; Wang, Yuliang; Zhong, Shuhui

    2017-04-01

    For any inhomogeneous compactly supported electromagnetic (EM) medium, it is shown that there exists an infinite set of linearly independent EM waves which generate nearly vanishing scattered wave fields. If the inhomogeneous medium is coated with a layer of properly chosen conducting medium, then the wave set is generated from the Maxwell-Herglotz approximation to the interior perfectly electric conducting or perfectly magnetic conducting eigenfunctions and depends only on the shape of the inhomogeneous medium. If no such a conducting coating is used, then the wave set is generated from the Maxwell-Herglotz approximation to the generalised interior transmission eigenfunctions and depends on both the content and shape of the inhomogeneous medium. We characterise the nearly non-scattering wave sets in both cases with sharp estimates. The results can be used to give a conceptual design of a novel shadowless lamp. The crucial ingredient is to properly choose the source of the lamp so that nearly no shadow will be produced by surgeons operating under the lamp.

  18. Feed network and electromagnetic radiation source

    Science.gov (United States)

    Ardavan, Arzhang; Singleton, John; Linehan, Kevin E.; Ardavan, Houshang; Schmidt-Zwiefel, Andrea Caroline

    2017-01-17

    An antenna may include a volume polarization current radiator and a feed network. The volume polarization current radiator, includes a dielectric solid (such as a dielectric strip), and a plurality of closely-spaced excitation elements (24), each excitation element (24) being configured to induce a volume polarization current distribution in the dielectric solid proximate to the excitation element when a voltage is applied to the excitation element. The feed network is coupled to the volume polarization current radiator. The feed network also includes a plurality of passive power divider elements (32) and a plurality of passive delay elements (d1-d6) coupling the first port (30) and the plurality of second ports (108, 109, 164), the plurality of power divider elements (32) and the plurality of phase delay elements (d1-d6) being configured such that a radio-frequency signal that is applied to the first port (30) experiences a progressive change of phase as it is coupled to the plurality of second ports (108, 109, 164) so as to cause the volume polarization current distribution to propagate along the dielectric solid.

  19. Electromagnetic radiation in a semi-compact space

    Science.gov (United States)

    Iso, Satoshi; Kitazawa, Noriaki; Yokoo, Sumito

    2018-02-01

    In this note, we investigate the electromagnetic radiation emitted from a revolving point charge in a compact space. If the point charge is circulating with an angular frequency ω0 on the (x , y)-plane at z = 0 with boundary conditions, x ∼ x + 2 πR and y ∼ y + 2 πR, it emits radiation into the z-direction of z ∈ [ - ∞ , + ∞ ]. We find that the radiation shows discontinuities as a function of ω0 R at which a new propagating mode with a different Fourier component appears. For a small radius limit ω0 R ≪ 1, all the Fourier modes except the zero mode on (x , y)-plane are killed, but an effect of squeezing the electric field totally enhances the radiation. In the large volume limit ω0 R → ∞, the energy flux of the radiation reduces to the expected Larmor formula.

  20. Polymers and electromagnetic radiation fundamentals and practical applications

    CERN Document Server

    Schnabel, Wolfram

    2014-01-01

    This first book to cover the interaction of polymers with radiation from the entire electromagnetic spectrum adopts a multidisciplinary approach to bridge polymer chemistry and physics, photochemistry, photophysics and materials science. The text is equally unique in its scope, devoting equal amounts of attention to the three aspects of synthesis, characterization, and applications. The first part deals with the interaction of polymers with non-ionizing radiation in the frequency-range from sub-terahertz via infrared radiation to visible and ultraviolet light, while the second covers interaction with ionizing radiation from the extreme ultraviolet to X-ray photons. The result is a systematic overview of how both types of radiation can be used for different polymerization approaches, spectroscopy methods and lithography techniques. Authored by a world-renowned researcher and teacher with over 40 years of experience in the field, this is a highly practical and authoritative guide.

  1. Invisibility of a metamaterial cloak illuminated by spherical electromagnetic wave

    Science.gov (United States)

    Meng, Fan-Yi; Liang, Ying; Wu, Qun; Li, Le-Wei

    2009-06-01

    In this paper, the invisibility of a metamaterial cloak illuminated by spherical electromagnetic wave is analytically investigated based on the full wave Mie scattering model. It is shown that for a cloak with ideal parameters the scattered field intensity is zero, but for a cloak with a loss, only the backscattering is exactly zero. Moreover, in the loss case, the scattered field intensity increases as the loss increases, which is very different from that in the conventional stealth case, where the scattered field intensity decreases as the loss of coated material increases. In addition, it is shown that scattering cross-section of the cloak with perturbed parameters decreases as the thickness of the cloak decreases, which means that thinner cloak can exhibit more stable invisibility.

  2. Electromagnetic waves in complex systems selected theoretical and applied problems

    CERN Document Server

    Velychko, Lyudmyla

    2016-01-01

    This book gives guidance to solve problems in electromagnetics, providing both examples of solving serious research problems as well as the original results to encourage further investigations. The book contains seven chapters on various aspects of resonant wave scattering, each solving one original problem. All of them are unified by the authors’ desire to show advantages of rigorous approaches at all stages, from the formulation of a problem and the selection of a method to the interpretation of results. The book reveals a range of problems associated with wave propagation and scattering in natural and artificial environments or with the design of antennas elements. The authors invoke both theoretical (analytical and numerical) and experimental techniques for handling the problems. Attention is given to mathematical simulations, computational efficiency, and physical interpretation of the experimental results. The book is written for students, graduate students and young researchers. .

  3. Rapid Loss of Radiation Belt Relativistic Electrons by EMIC Waves

    Science.gov (United States)

    Su, Zhenpeng; Gao, Zhonglei; Zheng, Huinan; Wang, Yuming; Wang, Shui; Spence, H. E.; Reeves, G. D.; Baker, D. N.; Wygant, J. R.

    2017-10-01

    How relativistic electrons are lost is an important question surrounding the complex dynamics of the Earth's outer radiation belt. Radial loss to the magnetopause and local loss to the atmosphere are two main competing paradigms. Here on the basis of the analysis of a radiation belt storm event on 27 February 2014, we present new evidence for the electromagnetic ion cyclotron (EMIC) wave-driven local precipitation loss of relativistic electrons in the heart of the outer radiation belt. During the main phase of this storm, the radial profile of relativistic electron phase space density was quasi-monotonic, qualitatively inconsistent with the prediction of radial loss theory. The local loss at low L shells was required to prevent the development of phase space density peak resulting from the radial loss process at high L shells. The rapid loss of relativistic electrons in the heart of outer radiation belt was observed as a dip structure of the electron flux temporal profile closely related to intense EMIC waves. Our simulations further confirm that the observed EMIC waves within a quite limited longitudinal region were able to reduce the off-equatorially mirroring relativistic electron fluxes by up to 2 orders of magnitude within about 1.5 h.

  4. Hanbury Brown-Twiss effect with electromagnetic waves.

    Science.gov (United States)

    Hassinen, T; Tervo, J; Setälä, T; Friberg, A T

    2011-08-01

    The classic Hanbury Brown-Twiss experiment is analyzed in the space-frequency domain by taking into account the vectorial nature of the radiation. We show that as in scalar theory, the degree of electromagnetic coherence fully characterizes the fluctuations of the photoelectron currents when a random vector field with Gaussian statistics is incident onto the detectors. Interpretation of this result in terms of the modulations of optical intensity and polarization state in two-beam interference is discussed. We demonstrate that the degree of cross-polarization may generally diverge. We also evaluate the effects of the state of polarization on the correlations of intensity fluctuations in various circumstances.

  5. A local-ether model of propagation of electromagnetic wave

    Energy Technology Data Exchange (ETDEWEB)

    Su, C.C. [Dept. of Electrical Engineering, National Tsinghua University, Hsinchu (Taiwan)

    2001-07-01

    It is pointed out that the classical propagation model can be in accord with the Sagnac effect due to earth's rotational and orbital motions in the high-precision GPS (global positioning system) and interplanetary radar, if the reference frame of the classical propagation medium is endowed with a switchability according to the location of the wave. Accordingly, it is postulated that, as in the obsolete theory, electromagnetic waves propagate via a medium like the ether. However, the ether is not universal. It is proposed that in the region under sufficient influence of the gravity due to the earth, the sun, or another celestial body, there forms a local ether, which in turn is stationary with respect to the gravitational potential of the respective body. For earthbound and interplanetary propagation, the medium is stationary in a geocentric and a heliocentric inertial frame, respectively. An electromagnetic wave propagates at a constant speed with respect to the associated local ether, independent of the motions of source and receiver. Based on this local-ether model of wave propagation, a wide variety of earthbound, interplanetary, and interstellar propagation phenomena are accounted for. Strong evidence of this new classical model is its consistent account of the Sagnac effect due to earth's motions among GPS, the intercontinental microwave link, and the interplanetary radar. Moreover, as examined within the present precision, this model is still in accord with the Michelson-Morley experiment. To test the local-ether propagation model, a one-way-link rotor experiment is proposed. (orig.)

  6. Structures, systems and methods for harvesting energy from electromagnetic radiation

    Science.gov (United States)

    Novack, Steven D [Idaho Falls, ID; Kotter, Dale K [Shelley, ID; Pinhero, Patrick J [Columbia, MO

    2011-12-06

    Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

  7. Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation

    Science.gov (United States)

    Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.

    2012-10-09

    Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

  8. Multipole charge conservation and implications on electromagnetic radiation

    Science.gov (United States)

    Seraj, Ali

    2017-06-01

    It is shown that conserved charges associated with a specific subclass of gauge symmetries of Maxwell electrodynamics are proportional to the well known electric mul-tipole moments. The symmetries are residual gauge transformations surviving the Lorenz gauge, with nontrivial conserved charge at spatial infinity. These "Multipole charges" receive contributions both from the charged matter and electromagnetic fields. The former is nothing but the electric multipole moment of the source. In a stationary configuration, there is a novel equipartition relation between the two contributions. The multipole charge, while conserved, can freely interpolate between the source and the electromagnetic field, and therefore can be propagated with the radiation. Using the multipole charge conservation, we obtain infinite number of constraints over the radiation produced by the dynamics of charged matter.

  9. Gold Nanocluster-Mediated Cellular Death under Electromagnetic Radiation.

    Science.gov (United States)

    Cifuentes-Rius, Anna; Ivask, Angela; Das, Shreya; Penya-Auladell, Nuria; Fabregas, Laura; Fletcher, Nicholas L; Houston, Zachary H; Thurecht, Kristofer J; Voelcker, Nicolas H

    2017-11-29

    Gold nanoclusters (Au NCs) have become a promising nanomaterial for cancer therapy because of their biocompatibility and fluorescent properties. In this study, the effect of ultrasmall protein-stabilized 2 nm Au NCs on six types of mammalian cells (fibroblasts, B-lymphocytes, glioblastoma, neuroblastoma, and two types of prostate cancer cells) under electromagnetic radiation is investigated. Cellular association of Au NCs in vitro is concentration-dependent, and Au NCs have low intrinsic toxicity. However, when Au NC-incubated cells are exposed to a 1 GHz electromagnetic field (microwave radiation), cell viability significantly decreases, thus demonstrating that Au NCs exhibit specific microwave-dependent cytotoxicity, likely resulting from localized heating. Upon i.v. injection in mice, Au NCs are still present at 24 h post administration. Considering the specific microwave-dependent cytotoxicity and low intrinsic toxicity, our work suggests the potential of Au NCs as effective and safe nanomedicines for cancer therapy.

  10. Structures, systems and methods for harvesting energy from electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Novack, Steven D [Idaho Falls, ID; Kotter, Dale K [Shelley, ID; Pinhero, Patrick J [Columbia, MO

    2011-12-06

    Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

  11. The First Unambiguous Electromagnetic Counterpart to a Gravitational-Wave Signal: GRB 170817A and GW170817

    Science.gov (United States)

    Goldstein, Adam

    2018-01-01

    On 2017 August 17 at 12:41:06 UTC the Fermi Gamma-ray Burst Monitor (GBM) detected and triggered on the short gamma-ray burst (GRB) 170817A. Approximately 2 s prior to this GRB, the LIGO gravitational-wave observatory triggered on a binary compact merger candidate associated with the GRB. This is the first unambiguous coincident observation of gravitational waves and electromagnetic radiation from a single astrophysical source and marks the start of gravitational-wave multi-messenger astronomy. We report the GBM observations and analysis of this short GRB and the joint science that results from this discovery.

  12. Local Tensor Radiation Conditions For Elastic Waves

    DEFF Research Database (Denmark)

    Krenk, S.; Kirkegaard, Poul Henning

    2001-01-01

    A local boundary condition is formulated, representing radiation of elastic waves from an arbitrary point source. The boundary condition takes the form of a tensor relation between the stress at a point on an arbitrarily oriented section and the velocity and displacement vectors at the point....... The tensor relation generalizes the traditional normal incidence impedance condition by accounting for the angle between wave propagation and the surface normal and by including a generalized stiffness term due to spreading of the waves. The effectiveness of the local tensor radiation condition...

  13. Optical analysis of human eye using electromagnetic wave theory.

    Science.gov (United States)

    Can, Melih G; Oner, Bilgehan B; Kurt, Hamza

    2013-10-01

    We present a two-dimensional electromagnetic analysis of light propagation through the human eye to examine the eye's optical properties. The electromagnetic approach has intriguing advantages over the conventional and frequently implemented ray optics analysis. The chromatic, spherical, and coma aberrations and the intensity of the focused light at the retina are computed in this work via full-wave analysis. We also investigate the effects of the cornea's and lens's curved structures on the focusing mechanism. The focal length and chromatic and spherical aberrations are observed to change owing to age-related refractive index variation in the lens. In addition, the effects of the lens and curvatures of the human eye on focusing are analyzed. Consequently, for both young and old human eye lenses, the differences due to the aberration variations, curvature surfaces, and gradient index are explored by the wave approach. The intensity distributions on the retina for both on- and off-axis illumination are calculated. A strong correlation between the locations of the nerve fibers and the intensity distribution is confirmed. On the basis of the findings, we can conclude that visual impairment due to deterioration of the human eye structure is more dramatic than that due to aging.

  14. Excitation of planetary electromagnetic waves in the inhomogeneous ionosphere

    Directory of Open Access Journals (Sweden)

    Yu. Rapoport

    2014-04-01

    Full Text Available In this paper we develop a new method for the analysis of excitation and propagation of planetary electromagnetic waves (PEMW in the ionosphere of the Earth. The nonlinear system of equations for PEMW, valid for any height, from D to F regions, including intermediate altitudes between D and E and between E and F regions, is derived. In particular, we have found the system of nonlinear one-fluid MHD equations in the β-plane approximation valid for the ionospheric F region (Aburjania et al., 2003a, 2005. The series expansion in a "small" (relative to the local geomagnetic field non-stationary magnetic field has been applied only at the last step of the derivation of the equations. The small mechanical vertical displacement of the media is taken into account. We have shown that obtained equations can be reduced to the well-known system with Larichev–Reznik vortex solution in the equatorial region (see e.g. Aburjania et al., 2002. The excitation of planetary electromagnetic waves by different initial perturbations has been investigated numerically. Some means for the PEMW detection and data processing are discussed.

  15. Interface Polarization Strategy to Solve Electromagnetic Wave Interference Issue.

    Science.gov (United States)

    Lv, Hualiang; Guo, Yuhang; Wu, Guanglei; Ji, Guangbin; Zhao, Yue; Xu, Zhichuan J

    2017-02-15

    Design of an interface to arouse interface polarization is an efficient route to attenuate high-frequency electromagnetic waves. The attenuation intensity is highly related to the contact area. To achieve stronger interface polarization, growing metal oxide granular film on graphene with a larger surface area seems to be an efficient strategy due to the high charge carrier concentration of graphene. This study is devoted to fabricating the filmlike composite by a facile thermal decomposition method and investigating the relationship among contact area, polarization intensity, and the type of metal oxide. Because of the high-frequency polarization effect, the composites presented excellent electromagnetic wave attenuation ability. It is shown that the optimal effective frequency bandwidth of graphene/metal oxide was close to 7.0 GHz at a thin coating layer of 2.0 mm. The corresponding reflection loss value was nearly -22.1 dB. Considering the attenuation mechanism, interface polarization may play a key role in the microwave-absorbing ability.

  16. Plug identification in drainage system using electromagnetic wave

    Science.gov (United States)

    Hijriani, Arifa; Utama, Aji Surya; Boas, Andrianus; Mukti, M. Ridho; Widodo

    2017-07-01

    The evaluation of drainage system's performance is an important thing to do to prevent flooding. Conventionally the Government evaluates the drainage system by opening one by one the lid of drainage and detects the plug manually. This method is not effective and efficient because this method need many people, much time and relatively expensive. The purpose of this paper is to identify plugs in drainage system in G St. at Bandung Institute of Technology by using electromagnetic wave. Ground Penetrating Radar (GPR) is one of geophysics method that using electromagnetic wave with high frequency. GPR is a non-destructive method with high resolution imaging for shallow depth (˜100m) and relatively cheap. We could identify the plug without opening the lid manually so that we could save much time. GPR's sensitivity is depends on resistivity, magnetic permeability, and permittivity of an object. The result of this research is we could identify the plug on the radargram that observed by a build-up amplitude anomaly.

  17. Biological Effects of Electromagnetic Radiation. Volume II, Number 4.

    Science.gov (United States)

    1975-12-01

    unclassified ~ .~~~I4 I~~I~O Security CIas,iac.tioft A - 1140S BiOLOGiCA L. EFFECTS OF ELECTROMAGNETIC RADIATION A Digest of Current Lite rature and a... arma , il. M . (Em — The control was heated to the same temperature. Environ. F.ng. Sci., Howard Univ., Washington , B. C.) Both samples were then

  18. Polarization of low-frequency electromagnetic radiation in the lobes of Jupiter's magnetotail

    Science.gov (United States)

    Moses, S. L.; Kennel, C. F.; Coroniti, F. V.; Scarf, F. L.; Kurth, W. S.

    1987-01-01

    The plasma wave instruments on the Voyager spacecraft have detected intense electromagnetic radiation within the lobes of Jupiter's magnetic tail down to the lowest frequency of the detector (10 Hz). During a yaw maneuver performed by Voyager 1 in the lobe of the Jovian magnetotail, a modulation appeared in the amplitudes of waves detected in the 10-, 17.8- and 31.1-Hz channels of the plasma wave analyzer, well below the local electron cyclotron frequency of 260 Hz. The lowest amplitudes occurred when the antenna axis was most nearly parallel to the magnetic field. Wave amplitudes in the 56.2-Hz and higher frequency channels remained nearly constant during the maneuver. From the cold-plasma theory of electromagnetic waves, it is concluded that the plasma frequency was between the 56.2- and 31.1-Hz channels where the parallel-polarized component of the spectrum cuts off. This implies a tail-lobe density between 0.000032 and 0.000015/cu cm. The left-hand cutoff frequency would then be below 10 Hz, consistent with either the Z-mode (L, X) or whistlers (R-mode) in the modulated channels.

  19. Rotatable illusion media for manipulating terahertz electromagnetic waves.

    Science.gov (United States)

    Zang, XiaoFei; Li, Zhou; Shi, Cheng; Chen, Lin; Cai, Bin; Zhu, YiMing; Li, Li; Wang, XiaoBin

    2013-10-21

    Based on composite optical transformation, we propose a rotatable illusion media with positive permittivity and permeability to manipulate terahertz waves, and a new way to realize singular parameter-independent cloaks when the incident wave with a certain width propagates from specific incident directions. The fundamental mechanism of this kind of cloak is that the illusion media can be able to avoid the incident wave interacting with the objects. Comparing with traditional transformation-coordinate-based cloaks such as cylindrical-shaped cloaks, our cloaks are independent of singular material parameters. Furthermore, this type of rotatable illusion media can be applied to design tunable miniaturized high-directivity antenna (a small antenna array covered with the rotatable illusion media appears like a large one and meanwhile, the radiation directions of the small antenna array is tunable via this rotatable illusion media). Full wave simulations are performed to confirm these points.

  20. Scattering of Non-Relativistic Charged Particles by Electromagnetic Radiation

    Science.gov (United States)

    Apostol, M.

    2017-11-01

    The cross-section is computed for non-relativistic charged particles (like electrons and ions) scattered by electromagnetic radiation confined to a finite region (like the focal region of optical laser beams). The cross-section exhibits maxima at scattering angles given by the energy and momentum conservation in multi-photon absorption or emission processes. For convenience, a potential scattering is included and a comparison is made with the well-known Kroll-Watson scattering formula. The scattering process addressed in this paper is distinct from the process dealt with in previous studies, where the scattering is immersed in the radiation field.

  1. Features of the Electromagnetic and Plasma Disturbances Induced at the Altitudes of the Earth's Outer Ionosphere by Modification of the Ionospheric F 2 Region Using High-Power Radio Waves Radiated by the SURA Heating Facility

    Science.gov (United States)

    Frolov, V. L.; Rapoport, V. O.; Schorokhova, E. A.; Belov, A. S.; Parrot, M.; Rauch, J.-L.

    2016-08-01

    In this paper we systematize the results of studying the characteristics of the plasma-density ducts, which was conducted in 2005-2010 during the DEMETER-satellite operation. The ducts are formed at altitudes of about 700 km as a result of the ionospheric F 2 region modification by high-power high-frequency radio waves radiated by the midlatitude SURA heating facility. All the performed measurements are used as the basis for determining the formation conditions for such ducts, the duct characteristics are studied, and the opportunities for the duct influence on the ionosphere-magnetosphere coupling and propagation of radio waves of various frequency ranges are demonstrated. The results of numerical simulation of the formation of such ducts are presented.

  2. On the effects of geometry on guided electromagnetic waves

    Directory of Open Access Journals (Sweden)

    Tucker Robin W.

    2007-01-01

    Full Text Available The method of moving (Cartan coframes is used to analyze the influence of geometry on the behavior of electromagnetic fields in confining guides and the effect of such fields on their ultra-relativistic sources. Such issues are of relevance to a number of topical problems in accelerator science where the need to control the motion of high current-density micro-meter size bunches of relativistic radiating charge remains a technical and theoretical challenge. By dimensionally reducing the exterior equations for the sources and fields on spacetime using symmetries exhibited by the confining guides one achieves a unifying view that offers natural perturbative approaches for dealing with smooth non-uniform and curved guides. The issue of the back-reaction of radiation fields on the sources is approached in terms of a simple charged relativistic fluid model. .

  3. Study of electromagnetic radiation pollution in an Indian city.

    Science.gov (United States)

    Dhami, A K

    2012-11-01

    Electromagnetic radiation emitted by cell phone towers is a form of environmental pollution and is a new health hazard, especially to children and patients. The present studies were taken to estimate the microwave/RF pollution by measuring radiation power densities near schools and hospitals of Chandigarh city in India. The cell phone radiations were measured using a handheld portable power density meter TES 593 and specific absorption rates were estimated from the measured values. These values of electromagnetic radiation in the environment were compared with the levels at which biological system of humans and animals starts getting affected. The values were also compared with the international exposure limits set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The highest measured power density was 11.48 mW/m(2) which is 1,148% of the biological limit. The results indicated that the exposure levels in the city were below the ICNIRP limit, but much above the biological limit.

  4. 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.

  5. INFLUENCE OF ELECTROMAGNETIC RADIATION ON TESTICULAR STRUCTURE AND STEROIDOGENESIS IN RATS

    Directory of Open Access Journals (Sweden)

    Viera Almášiová

    2013-06-01

    Full Text Available In the new era of intensive usage of modern electronic devices everybody is influenced by an accumulating effect of electromagnetic radiation (EMR more widely than ever in the past. EMR is a self-propagating wave in space with electric and magnetic components and is physically classed as non-ionising radiation. The immediate whole body electromagnetic radiation – EMR was used to investigate testicular structure and testosterone synthesis of the Wistar rats. Sexually mature (48 days old rats were subjected to pulsed electromagnetic fields at frequency of 2.45 GHz and mean power density of 2.8 mW/cm2 for 3 h per 3 weeks. Histological structure of the testicular parenchyma and plasma testosterone concentrations were evaluated in 21 days post irradiation. The light microscopy revealed moderate degenerative changes in testicular parenchyma as well as decreased plasma testosterone levels in experimental animals compared to the control counterpart which indicate an adverse effect of EMR on spermatogenesis and steroidogenesis in rats. These findings confirmed the evidence, that the testes are amongst the most susceptible organs to the EMR. Next studies are required for elucidation of relation between the EMR and widely debated disorders of fertility and fecundity not only in the human population.

  6. Propagation of electromagnetic wave in dusty plasma and the influence of dust size distribution

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui [Department of Physics, Harbin Institute of Technology, Harbin (China); China Research Institute of Radio Wave Propagation (CRIRP), Beijing (China); Wu, Jian [China Research Institute of Radio Wave Propagation (CRIRP), Beijing (China); Zhou, Zhongxiang; Yuan, Chengxun [Department of Physics, Harbin Institute of Technology, Harbin (China)

    2016-07-15

    The effect of charged dust particle and their size distribution on the propagation of electromagnetic wave in a dusty plasma is investigated. It is shown that the additional collision mechanism provided by charged dust particles can significantly alter the electromagnetic properties of a plasma, leading to the appearance of attenuation of electromagnetic wave through dusty plasma. The attenuation coefficient mainly depends on the dust density, radius, and the charge numbers on the dust surface. The results described here will be used to enhance understanding of electromagnetic wave propagation processed in space and laboratory dusty plasma.

  7. Apparatus and method for enhanced chemical processing in high pressure and atmospheric plasmas produced by high frequency electromagnetic waves

    Science.gov (United States)

    Efthimion, Philip C.; Helfritch, Dennis J.

    1989-11-28

    An apparatus and method for creating high temperature plasmas for enhanced chemical processing of gaseous fluids, toxic chemicals, and the like, at a wide range of pressures, especially at atmospheric and high pressures includes an electro-magnetic resonator cavity, preferably a reentrant cavity, and a wave guiding structure which connects an electro-magnetic source to the cavity. The cavity includes an intake port and an exhaust port, each having apertures in the conductive walls of the cavity sufficient for the intake of the gaseous fluids and for the discharge of the processed gaseous fluids. The apertures are sufficiently small to prevent the leakage of the electro-magnetic radiation from the cavity. Gaseous fluid flowing from the direction of the electro-magnetic source through the guiding wave structure and into the cavity acts on the plasma to push it away from the guiding wave structure and the electro-magnetic source. The gaseous fluid flow confines the high temperature plasma inside the cavity and allows complete chemical processing of the gaseous fluids at a wide range of pressures.

  8. Propagation of electromagnetic waves in stratified media with nonlinearity in both dielectric and magnetic responses.

    Science.gov (United States)

    Kim, Kihong; Phung, D K; Rotermund, F; Lim, H

    2008-01-21

    We develop a generalized version of the invariant imbedding method, which allows us to solve the electromagnetic wave equations in arbitrarily inhomogeneous stratified media where both the dielectric permittivity and magnetic permeability depend on the strengths of the electric and magnetic fields, in a numerically accurate and efficient manner. We apply our method to a uniform nonlinear slab and find that in the presence of strong external radiation, an initially uniform medium of positive refractive index can spontaneously change into a highly inhomogeneous medium where regions of positive or negative refractive index as well as metallic regions appear. We also study the wave transmission properties of periodic nonlinear media and the influence of nonlinearity on the mode conversion phenomena in inhomogeneous plasmas. We argue that our theory is very useful in the study of the optical properties of a variety of nonlinear media including nonlinear negative index media fabricated using wires and split-ring resonators.

  9. Kinetic Jeans instability and nonlinear damping of electromagnetic waves in self gravitating dusty plasma

    Science.gov (United States)

    Rozina, Ch.; Tsintsadze, N. L.; Madiha, M.; Zeba, I.

    2017-05-01

    A kinetic theory of the Jeans instability of a self gravitating dusty plasma has been developed in the presence of nonlinear Landau damping (NLD) term. We demonstrate that NLD alters the growth rate of the gravitational collapse of the gravitating dusty plasma. The dispersion relation of modified Jeans instability is obtained and analyzed for specific conditions. Jeans frequency is compared with the dust acoustic frequency; new definition of Jeans wave length is introduced. The maximum growth rate is obtained for a particular condition as well as the Jeans critical mass is defined. Next to address the heating of plasma through radiation processes, we investigate the nonlinear theory of high frequency electromagnetic waves (EMWs) in a collisionless dusty plasma by using a set of Vlasov-Poisson equations. The effects of the nonlocal nonlinear Landau term (appearing due to the nonlinear interaction of EMWs with gravitating dusty plasma) in the nonlinear Schrödinger equation are examined. It is found that nonlinear Landau damping of EMWs leads to transfer of effective energy to the plasma particles, the corresponding decay rate of EMWs appears to be a function of amplitude of electromagnetic pump waves, and damping can be faster in the presence of large ion number density.

  10. Second-Harmonic Generation by Electromagnetic Waves at the Surface of a Semi-Infinite Metal

    Science.gov (United States)

    2010-05-01

    Second-Harmonic Generation by Electromagnetic Waves at the Surface of a Semi-Infinite Metal Frank Crowne and Christian Fazi Sensors and...DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Second-Harmonic Generation by Electromagnetic Waves at the Surface of a Semi

  11. Examination of Bursty Electromagnetic Waves Observed During Intervals of Turbulent Magnetosheath Reconnection

    Science.gov (United States)

    Adrian, Mark L.; Wendel, D. E.

    2011-01-01

    We investigate observations of intense bursts of electromagnetic waves in association with magnetic reconnection in the turbulent magnetosheath. These structured, broadband bursts occur above 80-Hz, often displaying features reminiscent of absorption bands and are observed at local minima in the magnetic field. We present detailed analyses of these intense bursts of electromagnetic waves and quantify their proximity to X- and O-nulls.

  12. The Roles of Transport and Wave-Particle Interactions on Radiation Belt Dynamics

    Science.gov (United States)

    Fok, Mei-Ching; Glocer, Alex; Zheng, Qiuhua

    2011-01-01

    Particle fluxes in the radiation belts can vary dramatically during geomagnetic active periods. Transport and wave-particle interactions are believed to be the two main types of mechanisms that control the radiation belt dynamics. Major transport processes include substorm dipolarization and injection, radial diffusion, convection, adiabatic acceleration and deceleration, and magnetopause shadowing. Energetic electrons and ions are also subjected to pitch-angle and energy diffusion when interact with plasma waves in the radiation belts. Important wave modes include whistler mode chorus waves, plasmaspheric hiss, electromagnetic ion cyclotron waves, and magnetosonic waves. We investigate the relative roles of transport and wave associated processes in radiation belt variations. Energetic electron fluxes during several storms are simulated using our Radiation Belt Environment (RBE) model. The model includes important transport and wave processes such as substorm dipolarization in global MHD fields, chorus waves, and plasmaspheric hiss. We discuss the effects of these competing processes at different phases of the storms and validate the results by comparison with satellite and ground-based observations. Keywords: Radiation Belts, Space Weather, Wave-Particle Interaction, Storm and Substorm

  13. Solution of electromagnetic scattering and radiation problems using a spectral domain approach - A review

    Science.gov (United States)

    Mittra, R.; Ko, W. L.; Rahmat-Samii, Y.

    1979-01-01

    This paper presents a brief review of some recent developments on the use of the spectral-domain approach for deriving high-frequency solutions to electromagnetics scattering and radiation problems. The spectral approach is not only useful for interpreting the well-known Keller formulas based on the geometrical theory of diffraction (GTD), it can also be employed for verifying the accuracy of GTD and other asymptotic solutions and systematically improving the results when such improvements are needed. The problem of plane wave diffraction by a finite screen or a strip is presented as an example of the application of the spectral-domain approach.

  14. Propagation of electromagnetic waves in Bose-Einstein condensate of atoms with dipole moments

    OpenAIRE

    Poluektov, Yu. M.; Tanatarov, I. V.

    2014-01-01

    We study the propagation of electromagnetic waves in the Bose-Einstein condensate of atoms with both intrinsic dipole moments and those induced by the electric field. The modified Gross--Pitaevskii equation is used, which takes into account relaxation and interaction with the electromagnetic field. Two cases are considered: 1) when the dispersion curves of the electromagnetic wave and of the condensate excitations do not intercross and 2) when the condensate excitations' spectrum has a gap an...

  15. [Influence of electromagnetic radiation on toxicity of Vipera lebetina obtusa venom].

    Science.gov (United States)

    Abiev, G A; Babaev, E I; Topchieva, Sh A; Chumburidze, T B; Nemsitsveridze, N G

    2009-11-01

    The aim of the article was to study the effect of electromagnetic radiation on toxicity of Vipera lebetina obtusa venom. It was found that mice intoxicated with snake venom, with moderate to high exposure to electromagnetic radiation and mice intoxicated with venom, which had not been exposed to the radiation showed the same symptoms of intoxication and death. At the same time, the longevity of mice intoxicated with venom exposed to electromagnetic radiation was higher. The longevity of mice in control group was 25+/-5 min. The longevity of mice intoxicated with exposed to electromagnetic radiation snake venom was from 29 to 60 min. The research showed that the longevity of mice intoxicated with snake venom rose with the level of electromagnetic radiation intensity the snake was exposed to. Accordingly, snake venom, with exposure to high intensity electromagnetic radiation is less toxic.

  16. Electromagnetic Components of Auroral Hiss and Lower Hybrid Waves in the Polar Magnetosphere

    Science.gov (United States)

    Wong, H. K.

    1995-01-01

    DE-1 has frequently observed waves in the whistler and lower hybrid frequencies range. Besides the electrostatic components, these waves also exhibit electromagnetic components. It is generally believed that these waves are excited by the electron acoustic instability and the electron-beam-driven lower hybrid instability. Because the electron acoustic and the lower hybrid waves are predominately electrostatic waves, they cannot account for the observed electromagnetic components. In this work, it is suggested that these electromagnetic components can be explained by waves that are generated near the resonance cone and that propagate away from the source. The role that these electromagnetic waves can play in particle acceleration processes at low altitude is discussed.

  17. Wave acceleration of electrons in the Van Allen radiation belts.

    Science.gov (United States)

    Horne, Richard B; Thorne, Richard M; Shprits, Yuri Y; Meredith, Nigel P; Glauert, Sarah A; Smith, Andy J; Kanekal, Shrikanth G; Baker, Daniel N; Engebretson, Mark J; Posch, Jennifer L; Spasojevic, Maria; Inan, Umran S; Pickett, Jolene S; Decreau, Pierrette M E

    2005-09-08

    The Van Allen radiation belts are two regions encircling the Earth in which energetic charged particles are trapped inside the Earth's magnetic field. Their properties vary according to solar activity and they represent a hazard to satellites and humans in space. An important challenge has been to explain how the charged particles within these belts are accelerated to very high energies of several million electron volts. Here we show, on the basis of the analysis of a rare event where the outer radiation belt was depleted and then re-formed closer to the Earth, that the long established theory of acceleration by radial diffusion is inadequate; the electrons are accelerated more effectively by electromagnetic waves at frequencies of a few kilohertz. Wave acceleration can increase the electron flux by more than three orders of magnitude over the observed timescale of one to two days, more than sufficient to explain the new radiation belt. Wave acceleration could also be important for Jupiter, Saturn and other astrophysical objects with magnetic fields.

  18. In vitro effects of radiofrequency electromagnetic waves on bovine spermatozoa motility.

    Science.gov (United States)

    Lukac, Norbert; Massanyi, Peter; Roychoudhury, Shubhadeep; Capcarova, Marcela; Tvrda, Eva; Knazicka, Zuzana; Kolesarova, Anna; Danko, Jan

    2011-01-01

    In this study the effects of 1800 MHz GSM-like radiofrequency electromagnetic waves (RF-EMW) exposure on bovine semen was monitored. The experimental samples were analyzed in vitro in four time periods (0, 30, 120 and 420 min) and compared with unexposed samples (control). Spermatozoa motility was determined by computer assisted semen analyzer (CASA). Evaluation of the percentage of motile spermatozoa showed significant (P radiation suggested that the parameters of path and velocity at the beginning of the culture significantly increase, but after longer culture (420 minutes) a significant decrease occur in the experimental group as compared to control. In general, results of this experiment indicate a negative time-dependent effect of 1800 MHz RF-EMW radiation on bovine spermatozoa motility.

  19. Multiple bio-monitoring system using visible light for electromagnetic-wave free indoor healthcare

    Science.gov (United States)

    An, Jinyoung; Pham, Ngoc Quan; Chung, Wan-Young

    2017-12-01

    In this paper, a multiple biomedical data transmission system with visible light communication (VLC) is proposed for an electromagnetic-wave-free indoor healthcare. VLC technology has emerged as an alternative solution to radio-frequency (RF) wireless systems, due to its various merits, e.g., ubiquity, power efficiency, no RF radiation, and security. With VLC, critical bio-medical signals, including electrocardiography (ECG), can be transmitted in places where RF radiation is restricted. This potential advantage of VLC could save more lives in emergency situations. A time hopping (TH) scheme is employed to transfer multiple medical-data streams in real time with a simple system design. Multiple data streams are transmitted using identical color LEDs and go into an optical detector. The received multiple data streams are demodulated and rearranged using a TH-based demodulator. The medical data is then monitored and managed to provide the necessary medical care for each patient.

  20. Electromagnetic waves near the proton cyclotron frequency: Stereo observations

    Energy Technology Data Exchange (ETDEWEB)

    Jian, L. K. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Wei, H. Y.; Russell, C. T. [Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095 (United States); Luhmann, J. G. [Space Science Laboratory, University of California, Berkeley, CA 94720 (United States); Klecker, B. [Max-Planck-Institut für Extraterrestrische Physik, D-85741 Garching (Germany); Omidi, N. [Solana Scientific Inc., Solana Beach, CA 92075 (United States); Isenberg, P. A. [Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824 (United States); Goldstein, M. L.; Figueroa-Viñas, A. [Heliophysics Science Division, NASA Goddard Space Flight Center, MD 20771 (United States); Blanco-Cano, X., E-mail: lan.jian@nasa.gov [Instituto de Geofisica, Universidad Nacional Autónoma de México, Coyoacán D.F. (Mexico)

    2014-05-10

    Transverse, near-circularly polarized, parallel-propagating electromagnetic waves around the proton cyclotron frequency were found sporadically in the solar wind throughout the inner heliosphere. They could play an important role in heating and accelerating the solar wind. These low-frequency waves (LFWs) are intermittent but often occur in prolonged bursts lasting over 10 minutes, named 'LFW storms'. Through a comprehensive survey of them from Solar Terrestrial Relations Observatory A using dynamic spectral wave analysis, we have identified 241 LFW storms in 2008, present 0.9% of the time. They are left-hand (LH) or right-hand (RH) polarized in the spacecraft frame with similar characteristics, probably due to Doppler shift of the same type of waves or waves of intrinsically different polarities. In rare cases, the opposite polarities are observed closely in time or even simultaneously. Having ruled out interplanetary coronal mass ejections, shocks, energetic particles, comets, planets, and interstellar ions as LFW sources, we discuss the remaining generation scenarios: LH ion cyclotron instability driven by greater perpendicular temperature than parallel temperature or by ring-beam distribution, and RH ion fire hose instability driven by inverse temperature anisotropy or by cool ion beams. The investigation of solar wind conditions is compromised by the bias of the one-dimensional Maxwellian fit used for plasma data calibration. However, the LFW storms are preferentially detected in rarefaction regions following fast winds and when the magnetic field is radial. This preference may be related to the ion cyclotron anisotropy instability in fast wind and the minimum in damping along the radial field.

  1. Mesoscopic correlation with polarization rotation of electromagnetic waves.

    Science.gov (United States)

    Chabanov, A A; Trégourès, N P; van Tiggelen, B A; Genack, A Z

    2004-04-30

    Mesoscopic correlations are observed in the polarization of microwave radiation transmitted through a random waveguide. These measurements, supported by diagrammatic theory, permit an unambiguous decomposition of the intensity correlation function of a vector wave into short, long, and infinite range components. Infinite range correlation that leads to universal conductance fluctuations is measured and found to be in agreement with calculations. The long and infinite range components include nonuniversal frequency-independent terms associated with coupling into and out of the sample.

  2. Plane-wave spectrum approach for the calculation of electromagnetic absorption under near-field exposure conditions.

    Science.gov (United States)

    Chatterjee, I; Gandhi, O P; Hagmann, M J; Riazi, A

    1980-01-01

    The exposure of humans to electromagnetic near fields has not been sufficiently emphasized by researcher. We have used the plane-wave-spectrum approach to evaluate the electromagnetic field and determine the energy deposited in a lossy, homogeneous, semi-infinite slab placed in the near field of a source leaking radiation. Values of the fields and absorbed energy in the target are obtained by vector summation of the contributions of all the plane waves into which the prescribed field is decomposed. Use of a fast Fourier transform algorithm contributes to the high efficiency of the computations. The numerical results show that, for field distributions that are nearly constant over a physical extent of at least a free-space wavelength, the energy coupled into the target is approximately equal to the resulting from plane-wave exposed.

  3. Semiannual Status Report. [excitation of electromagnetic waves in the whistler frequency range

    Science.gov (United States)

    1994-01-01

    During the last six months, we have continued our study of the excitation of electromagnetic waves in the whistler frequency range and the role that these waves will play in the acceleration of electrons and ions in the auroral region. A paper entitled 'Electron Beam Excitation of Upstream Waves in the Whistler Mode Frequency Range' was listed in the Journal of Geophysical Research. In this paper, we have shown that an anisotropic electron beam (or gyrating electron beam) is capable of generating both left-hand and right-hand polarized electromagnetic waves in the whistler frequency range. Since right-hand polarized electromagnetic waves can interact with background electrons and left-hand polarized waves can interact with background ions through cyclotron resonance, it is possible that these beam generated left-hand and right-hand polarized electromagnetic waves can accelerate either ions or electrons (or both), depending on the physical parameters under consideration. We are currently carrying out a comprehensive study of the electromagnetic whistler and lower hybrid like waves observed in the auroral zone using both wave and particle data. Our first task is to identify these wave modes and compare it with particle observations. Using both the DE-1 particle and wave measurements, we can positively identify those electromagnetics lower hybrid like waves as fast magnetosonic waves and the upper cutoff of these waves is the local lower hybrid frequency. From the upper cutoff of the frequency spectrum, one can infer the particle density and the result is in very good agreement with the particle data. Since these electromagnetic lower hybrid like waves can have frequencies extended down to the local ion cyclotron frequency, it practically confirms that they are not whistler waves.

  4. Scattering of electromagnetic plane waves by a buried vertical dike

    Directory of Open Access Journals (Sweden)

    Batista Lurimar S.

    2003-01-01

    Full Text Available The complete and exact solution of the scattering of a TE mode frequency domain electromagnetic plane wave by a vertical dike under a conductive overburden has been established. An integral representation composed of one-sided Fourier transforms describes the scattered electric field components in each one of the five media: air, overburden, dike, and the country rocks on both sides of the dike. The determination of the terms of the series that represents the spectral components of the Fourier integrals requires the numerical inversion of a sparse matrix, and the method of successive approaches. The zero-order term of the series representation for the spectral components of the overburden, for given values of the electrical and geometrical parameters of the model, has been computed. This result allowed to determine an approximate value of the variation of the electric field on the top of the overburden in the direction perpendicular to the strike of the dike. The results demonstrate the efficiency of this forward electromagnetic modeling, and are fundamental for the interpretation of VLF and Magnetotelluric data.

  5. Electromagnetic wave propagation through a slab of a dispersive medium

    CERN Document Server

    Ismail, Mohamed

    2016-01-01

    A method is proposed for the analysis of the propagation of electromagnetic waves through a homogeneous slab of a medium with Drude-Lorentz dispersion behavior, and excited by a causal sinusoidal source. An expression of the time dependent field, free from branch-cuts in the plane of complex frequencies, is established. This method provides the complete temporal response in both the steady-state and transient regimes in terms of discrete poles contributions. The Sommerfeld and Brillouin precursors are retrieved and the corresponding set of poles are identified. In addition, the contribution in the transient field of the resonance frequency in the Drude-Lorentz model is exhybited, and the effect of reflections resulting from the refractive index mismatch at the interfaces of the slab are analyzed.

  6. Diffraction of Electromagnetic Wave by Circular Disk and Circular Hole

    CERN Document Server

    Shahzad, Muhammad Adnan

    2010-01-01

    The problem of diffraction of an electromagnetic plane wave by a perfectly conducting circular disk and its complementary problem, diffraction by a circular hole in an infinite conducting plate, are rigorously solved using the method of the Kobayashi potential. The mathematical formulation involved dual integral equation derived from the potential integral and boundary condition on the plane where a disk or hole is located. The weighting function in the potential integral are determined by applying the properties of the Weber-Schafheitlin's discontinuous integral and the solution are obtained in the form of a matrix equation. The matrix elements of the equations for the expansion coefficients are given by three kinds of infinite integral and the series solution for these infinite integral are derived. For the verification of these series solution, the numerical integral are derived and the results are computed numerically using the method of Gaussian quadrature for conformation. The numerical results are give...

  7. Electromagnetic waves propagation through a stochastic anisotropic medium

    Energy Technology Data Exchange (ETDEWEB)

    Ledinegg, E.

    1985-01-01

    Electromagnetic waves propagating through a stochastic medium are disturbed by field fluctuations. These can be treated by use of multiple scattering theories in order to get realistic results. In this paper, the multiple scattering theory developed by B.J. Uscinski is employed for anisotropic media and first and second-order field moments are calculated. Extending an earlier paper, the author considers primary fields with an arbitrary angle of incidence in order to investigate problems of practical interest (i.e.: radio propagation through the ionosphere between satellite and ground stations). As a result, it is shown that the attenuation factor of the first order field moment depends strongly on the angle of incidence due to media fluctuations.

  8. A kilonova as the electromagnetic counterpart to a gravitational-wave source

    Science.gov (United States)

    Smartt, S. J.; Chen, T.-W.; Jerkstrand, A.; Coughlin, M.; Kankare, E.; Sim, S. A.; Fraser, M.; Inserra, C.; Maguire, K.; Chambers, K. C.; Huber, M. E.; Krühler, T.; Leloudas, G.; Magee, M.; Shingles, L. J.; Smith, K. W.; Young, D. R.; Tonry, J.; Kotak, R.; Gal-Yam, A.; Lyman, J. D.; Homan, D. S.; Agliozzo, C.; Anderson, J. P.; Angus, C. R.; Ashall, C.; Barbarino, C.; Bauer, F. E.; Berton, M.; Botticella, M. T.; Bulla, M.; Bulger, J.; Cannizzaro, G.; Cano, Z.; Cartier, R.; Cikota, A.; Clark, P.; De Cia, A.; Della Valle, M.; Denneau, L.; Dennefeld, M.; Dessart, L.; Dimitriadis, G.; Elias-Rosa, N.; Firth, R. E.; Flewelling, H.; Flörs, A.; Franckowiak, A.; Frohmaier, C.; Galbany, L.; González-Gaitán, S.; Greiner, J.; Gromadzki, M.; Guelbenzu, A. Nicuesa; Gutiérrez, C. P.; Hamanowicz, A.; Hanlon, L.; Harmanen, J.; Heintz, K. E.; Heinze, A.; Hernandez, M.-S.; Hodgkin, S. T.; Hook, I. M.; Izzo, L.; James, P. A.; Jonker, P. G.; Kerzendorf, W. E.; Klose, S.; Kostrzewa-Rutkowska, Z.; Kowalski, M.; Kromer, M.; Kuncarayakti, H.; Lawrence, A.; Lowe, T. B.; Magnier, E. A.; Manulis, I.; Martin-Carrillo, A.; Mattila, S.; McBrien, O.; Müller, A.; Nordin, J.; O’Neill, D.; Onori, F.; Palmerio, J. T.; Pastorello, A.; Patat, F.; Pignata, G.; Podsiadlowski, Ph.; Pumo, M. L.; Prentice, S. J.; Rau, A.; Razza, A.; Rest, A.; Reynolds, T.; Roy, R.; Ruiter, A. J.; Rybicki, K. A.; Salmon, L.; Schady, P.; Schultz, A. S. B.; Schweyer, T.; Seitenzahl, I. R.; Smith, M.; Sollerman, J.; Stalder, B.; Stubbs, C. W.; Sullivan, M.; Szegedi, H.; Taddia, F.; Taubenberger, S.; Terreran, G.; van Soelen, B.; Vos, J.; Wainscoat, R. J.; Walton, N. A.; Waters, C.; Weiland, H.; Willman, M.; Wiseman, P.; Wright, D. E.; Wyrzykowski, Ł.; Yaron, O.

    2017-11-01

    Gravitational waves were discovered with the detection of binary black-hole mergers and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate. Here we report observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817 and with a weak, short γ-ray burst. The transient has physical parameters that broadly match the theoretical predictions of blue kilonovae from neutron-star mergers. The emitted electromagnetic radiation can be explained with an ejected mass of 0.04 ± 0.01 solar masses, with an opacity of less than 0.5 square centimetres per gram, at a velocity of 0.2 ± 0.1 times light speed. The power source is constrained to have a power-law slope of ‑1.2 ± 0.3, consistent with radioactive powering from r-process nuclides. (The r-process is a series of neutron capture reactions that synthesise many of the elements heavier than iron.) We identify line features in the spectra that are consistent with light r-process elements (atomic masses of 90–140). As it fades, the transient rapidly becomes red, and a higher-opacity, lanthanide-rich ejecta component may contribute to the emission. This indicates that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.

  9. Effects of 900 MHz electromagnetic radiation on ultrastructure of rats’ hippocampal neural stem cells in vitro

    Directory of Open Access Journals (Sweden)

    Hai-shui LUO

    2012-04-01

    Full Text Available Objective To investigate the effect of 900MHz electromagnetic radiation on the ultrastructure of rat hippocampal neural stem cells (NSCs in vitro in order to provide basic materials for studying the biological effects of electromagnetic wave on the central nervous system. Methods Rat NSCs were divided into sham group, Radi1 group and Radi2 group, and they were respectively exposed to 900 MHz electromagnetic wave at power density of 0, 1, and 3mW/cm2 in vitro. Cells in Radi1 group and Radi2 group were sub-grouped according to the way radiation was given: continuous irradiation, in which cells were exposed on the second day after culture for 2h per day for 6 consecutive days; single exposure to irradiation, in which cells were exposed for 12h on the sixth day after the culture. The ultrastructural changes on the surface of the cells were observed with atomic force microscope (AFM, whereas the ultrastructural changes in the cells were observed with transmission electron microscope (TEM. Results After 900 MHz electromagnetic radiation, when compared with the sham group (0mW/cm2, it was shown that the surface of neural stem cells in the exposure groups (1 and 3mW/cm2 became rough, and there were some changes such as "cavitation" and "fissure formation" in the membrane. The intracellular ultrastructure was found to have obviously disrupted in the exposure groups, such as homogenization of cytoplasm, obvious change organelle structure, morphological damage of structure of nucleus, nuclear membrane disappearance, and chromatin pyknosis, and the changes were more obvious in Radi2 group. Compared with the sham group, the surface roughness (Ra of cells in the exposure group was significantly intensified (P < 0.05, and it was higher in Radi2 group than that in Radi1 group (P < 0.05. Conclusion A 900MHz electromagnetic radiation may cause injury changes in NSCs membrane and ultrastructure in vitro, and the extent of injury may be related to the

  10. Arguments for fundamental emission by the parametric process L yields T + S in interplanetary type III bursts. [langmuir, electromagnetic, ion acoustic waves (L, T, S)

    Science.gov (United States)

    Cairns, I. H.

    1984-01-01

    Observations of low frequency ion acoustic-like waves associated with Langmuir waves present during interplanetary Type 3 bursts are used to study plasma emission mechanisms and wave processes involving ion acoustic waves. It is shown that the observed wave frequency characteristics are consistent with the processes L yields T + S (where L = Langmuir waves, T = electromagnetic waves, S = ion acoustic waves) and L yields L' + S proceeding. The usual incoherent (random phase) version of the process L yields T + S cannot explain the observed wave production time scale. The clumpy nature of the observed Langmuir waves is vital to the theory of IP Type 3 bursts. The incoherent process L yields T + S may encounter difficulties explaining the observed Type 3 brightness temperatures when Langmuir wave clumps are incorporated into the theory. The parametric process L yields T + S may be the important emission process for the fundamental radiation of interplanetary Type 3 bursts.

  11. Harvesting the Energy of Multi-Polarized Electromagnetic Waves.

    Science.gov (United States)

    Almoneef, Thamer S; Erkmen, Faruk; Ramahi, Omar M

    2017-11-07

    We present the idea and design of a dual polarized metasurface for electromagnetic energy harvesting. A 4 × 4 super cell with alternating vias between adjacent cells was designed to allow for capturing the energy from various incident angles at an operating frequency of 2.4 GHz. The collected energy is then channeled to a feeding network that collects the AC power and feeds it to a rectification circuitry. The simulation results yielded a radiation to AC and an AC to DC conversion efficiencies of around 90% and 80%, respectively. As a proof of concept, an array consisting of 9 super cells was fabricated and measured. The experimental results show that the proposed energy harvester is capable of capturing up to 70% of the energy from a planewave having various polarizations and converting it to usable DC power.

  12. Parallel Numerical Simulations of Three-Dimensional Electromagnetic Radiation with MPI-CUDA Paradigms

    OpenAIRE

    He, Bing; Tang, Long; Xie, Jiang; Wang, XiaoWei; Song, AnPing

    2015-01-01

    Using parallel computation can enhance the performance of numerical simulation of electromagnetic radiation and get great runtime reduction. We simulate the electromagnetic radiation calculation based on the multicore CPU and GPU Parallel Architecture Clusters by using MPI-OpenMP and MPI-CUDA hybrid parallel algorithm. This is an effective solution comparing to the traditional finite-difference time-domain method which has a shortage in the calculation of the electromagnetic radiation on the ...

  13. Current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation

    OpenAIRE

    N Hatefi Kargan

    2013-01-01

     In this paper, current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation has been calculated and compared with the results when there is no electromagnetic radiation. For calculating current -voltage characteristic, it is required to calculate the transmission coefficient of electrons from the well and barrier structures of this device. For calculating the transmission coefficient of electrons at the presence of electromagnetic radiation, Finite Difference ...

  14. Electromagnetic Radiation in Multiply Connected Robertson-Walker Cosmologies

    CERN Document Server

    Tomaschitz, R

    1993-01-01

    Maxwell's equations on a topologically nontrivial cosmological background are studied. The cosmology is locally determined by a Robertson-Walker line element, but the spacelike slices are open hyperbolic manifolds, whose topology and geometry may vary in time. In this context the spectral resolution of Maxwell's equations in terms of horospherical elementary waves generated at infinity of hyperbolic space is given. The wave fronts are orthogonal to bundles of unstable geodesic rays, and the eikonal of geometric optics appears just as the phase of the horospherical waves. This fact is used to attach to the unstable geodesic rays a quantum mechanical momentum. In doing so the quantized energy-momentum tensor of the radiation field is constructed in a geometrically and dynamically transparent way, without appealing to the intricacies of the second quantization. In particular Planck's radiation formula, and the bearing of the multiply connected topology on the fluctuations in the temperature of the background rad...

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

    Science.gov (United States)

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

    2018-01-01

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

  16. Detection of electromagnetic radiation using micromechanical multiple quantum wells structures

    Science.gov (United States)

    Datskos, Panagiotis G [Knoxville, TN; Rajic, Slobodan [Knoxville, TN; Datskou, Irene [Knoxville, TN

    2007-07-17

    An apparatus and method for detecting electromagnetic radiation employs a deflectable micromechanical apparatus incorporating multiple quantum wells structures. When photons strike the quantum-well structure, physical stresses are created within the sensor, similar to a "bimetallic effect." The stresses cause the sensor to bend. The extent of deflection of the sensor can be measured through any of a variety of conventional means to provide a measurement of the photons striking the sensor. A large number of such sensors can be arranged in a two-dimensional array to provide imaging capability.

  17. 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.

  18. 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...

  19. Specific Electromagnetic Effects of Microwave Radiation on Escherichia coli▿

    OpenAIRE

    Shamis, Yury; Taube, Alex; Mitik-Dineva, Natasa; Croft, Rodney; Crawford, Russell J.; Ivanova, Elena P.

    2011-01-01

    The present study investigated the effects of microwave (MW) radiation applied under a sublethal temperature on Escherichia coli. The experiments were conducted at a frequency of 18 GHz and at a temperature below 40°C to avoid the thermal degradation of bacterial cells during exposure. The absorbed power was calculated to be 1,500 kW/m3, and the electric field was determined to be 300 V/m. Both values were theoretically confirmed using CST Microwave Studio 3D Electromagnetic Simulation Softwa...

  20. Electromagnetic Waves and Bursty Electron Acceleration: Implications from Freja

    Science.gov (United States)

    Andersson, Laila; Ivchenko, N.; Wahlund, J.-E.; Clemmons, J.; Gustavsson, B.; Eliasson, L.

    2000-01-01

    Dispersive Alfven wave activity is identified in four dayside auroral oval events measured by the Freja satellite. The events are characterized by ion injection, bursty electron precipitation below about I keV, transverse ion heating and broadband extremely low frequency (ELF) emissions below the lower hybrid cutoff frequency (a few kHz). The broadband emissions are observed to become more electrostatic towards higher frequencies. Large-scale density depletions/cavities, as determined by the Langmuir probe measurements, and strong electrostatic emissions are often observed simultaneously. A correlation study has been carried out between the E- and B-field fluctuations below 64 Hz (the dc instrument's upper threshold) and the characteristics of the precipitating electrons. This study revealed that the energization of electrons is indeed related to the broadband ELF emissions and that the electrostatic component plays a predominant role during very active magnetospheric conditions. Furthermore, the effect of the ELF electromagnetic emissions on the larger scale field-aligned current systems has been investigated, and it is found that such an effect cannot be detected. Instead, the Alfvenic activity creates a local region of field-aligned currents. It is suggested that dispersive Alfven waves set up these local field-aligned current regions and in turn trigger more electrostatic emissions during certain conditions. In these regions ions are transversely heated, and large-scale density depletions/cavities may be created during especially active periods.

  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. Risk perception and public concerns of electromagnetic waves from cellular phones in Korea.

    Science.gov (United States)

    Kim, Kyunghee; Kim, Hae-Joon; Song, Dae Jong; Cho, Yong Min; Choi, Jae Wook

    2014-05-01

    In this study, the difference between the risk perception of electromagnetic waves from cellular phones and the risk perception of other factors such as environment and food was analyzed. The cause of the difference in the psychological and social factors that affect the group with high risk perception of electromagnetic waves was also analyzed. A questionnaire survey on the risk perception of electromagnetic waves from cellular phones was carried out on 1001 subjects (men and women) over the age of 20. In the group with high risk perception of electromagnetic waves from cellular phones, women had higher risk perception than men. Logistic regression analysis, where the group with high risk perception of electromagnetic waves and the group with low risk perception were used as dependent variables, indicated that the risk perception of electromagnetic waves in women was 1.815 times statistically significantly higher than the risk perception of men (95% CI: 1.340-2.457). Also, high risk perception of electromagnetic waves from cellular phones was observed when the subjects considered that they had more personal knowledge (OR: 1.416, 95% CI: 1.216-1.648), that the seriousness of the risk to future generations was high (OR: 1.410, 95% CI: 1.234-1.611), and their outrage for the occurrence of accidents related to electromagnetic waves was high (OR: 1.460, 95% CI: 1.264-1.686). The results of this study need to be sufficiently considered and reflected in designing the risk communication strategies and communication methods for the preventive measures and advice on electromagnetic waves from cellular phones. © 2014 Wiley Periodicals, Inc.

  3. Electromagnetic waves and bursty electron acceleration: implications from Freja

    Directory of Open Access Journals (Sweden)

    L. Andersson

    Full Text Available Dispersive Alfvén wave activity is identified in four dayside auroral oval events measured by the Freja satellite. The events are characterized by ion injection, bursty electron precipitation below about 1 keV, transverse ion heating and broadband extremely low frequency (ELF emissions below the lower hybrid cutoff frequency (a few kHz. Large-scale density depletions/cavities, as determined by the Langmuir probe measurements, and strong electrostatic emissions are often observed simultaneously. A correlation study has been carried out between the E and B field fluctuations below 64 Hz and 10 Hz, respectively, (the DC instruments upper threshold and the characteristics of the precipitating electrons. This study revealed that the energisation of electrons is indeed related to the broadband ELF emissions and that the electrostatic component plays a predominant role during very active magnetospheric conditions. Furthermore, the effect of the ELF electromagnetic emissions on the larger scale field-aligned current systems has been investigated, and it is found that such an effect cannot be detected. Instead, the Alfvénic activity creates a local region of field-aligned currents. It is suggested that dispersive Alfvén waves set up these local field-aligned current regions and, in turn, trigger more electrostatic emissions during certain conditions. In these regions, ions are transversely heated, and large-scale density depletions/cavities may be created during especially active periods.

    Key words. Ionosphere (particle acceleraton; wave-particle interactions Magnetospheric physics (auroral phenomena

  4. Radiation Bandwidth Improvement of Electromagnetic Band Gap Cavity Antenna

    Science.gov (United States)

    Chaabane, Abdelhalim; Djahli, Farid; Attia, Hussein; Denidni, Tayeb. A.

    2017-05-01

    In this paper, an electromagnetic band gap cavity antenna with improved radiation and impedance bandwidths is presented. The proposed antenna is constructed by placing a triple-layer heterogeneous printed-unprinted partially reflective surface (PRS) above a primary aperture-coupled patch antenna. The PRS unit-cell provides a positive gradient reflection phase behavior over the desired frequency range. A prototype antenna is fabricated and measured that highlighted its ability to achieve 3-dB gain bandwidth of about 35.9 %, from 7.93 GHz to 11.4 GHz, with a peak gain of 14.25 dBi at 8.5 GHz. In addition, the impedance bandwidth is 40.32 %, from 7.9 GHz to 11.89 GHz. Thus, the designed antenna outperforms many other competitors for improving the radiation bandwidth of planar antennas with the same presented concept.

  5. Geometrical Effects on the Electromagnetic Radiation from Lightning Return Strokes

    Science.gov (United States)

    Willett, J. C.; Smith, D. A.; LeVine, D. M.; Zukor, Dorothy J. (Technical Monitor)

    2001-01-01

    The morphological difference between the electromagnetic radiation-field waveforms of "first" and "subsequent" return strokes in cloud-to-ground lightning flashes is well known and can be used to identify the formation of new channels to ground. This difference is generally believed due to the existence of branches on first-stroke channels, whereas subsequent strokes re-illuminate only the main channel of a previous stroke; but experimental evidence for this hypothesis is relatively weak. It has been argued for the influence of channel geometry on the fine structure of radiation from subsequent return strokes by comparing the field-change waveforms recorded at the same station from strokes within the same flash and between different flashes of both natural and triggered lightning. The present paper introduces new evidence for both of these hypotheses from a comparison of waveforms between sensors in different directions from the same stroke.

  6. Thin Perfect Absorbers for Electromagnetic Waves: Theory, Design, and Realizations

    Science.gov (United States)

    Ra'di, Y.; Simovski, C. R.; Tretyakov, S. A.

    2015-03-01

    With recent advances in nanophotonics and nanofabrication, considerable progress has been achieved in realizations of thin composite layers designed for full absorption of incident electromagnetic radiation, from microwaves to the visible. If the layer is structured at a subwavelength scale, thin perfect absorbers are usually called "metamaterial absorbers," because these composite structures are designed to emulate some material responses not reachable with any natural material. On the other hand, many thin absorbing composite layers were designed and used already in the time of the introduction of radar technology, predominantly as a means to reduce radar visibility of targets. In view of a wide variety of classical and new topologies of optically thin metamaterial absorbers and plurality of applications, there is a need for a general, conceptual overview of the fundamental mechanisms of full absorption of light or microwave radiation in thin layers. Here, we present such an overview in the form of a general theory of thin perfectly absorbing layers. Possible topologies of perfect metamaterial absorbers are classified based on their fundamental operational principles. For each of the identified classes, we provide design equations and give examples of particular realizations. The concluding section provides a summary and gives an outlook on future developments in this field.

  7. Metamaterials, from electromagnetic waves to water waves, bending waves and beyond

    KAUST Repository

    Dupont, G.

    2015-08-04

    We will review our recent work on metamaterials for different types of waves. Transposition of transform optics to water waves and bending waves on plates will be considered with potential applications of cloaking to water waves protection and anti-vibrating systems.

  8. The Schrödinger Equation, the Zero-Point Electromagnetic Radiation, and the Photoelectric Effect

    Science.gov (United States)

    França, H. M.; Kamimura, A.; Barreto, G. A.

    2016-04-01

    A Schrödinger type equation for a mathematical probability amplitude Ψ( x, t) is derived from the generalized phase space Liouville equation valid for the motion of a microscopic particle, with mass M and charge e, moving in a potential V( x). The particle phase space probability density is denoted Q( x, p, t), and the entire system is immersed in the "vacuum" zero-point electromagnetic radiation. We show, in the first part of the paper, that the generalized Liouville equation is reduced to a simpler Liouville equation in the equilibrium limit where the small radiative corrections cancel each other approximately. This leads us to a simpler Liouville equation that will facilitate the calculations in the second part of the paper. Within this second part, we address ourselves to the following task: Since the Schrödinger equation depends on hbar , and the zero-point electromagnetic spectral distribution, given by ρ 0{(ω )} = hbar ω 3/2 π 2 c3, also depends on hbar , it is interesting to verify the possible dynamical connection between ρ 0( ω) and the Schrödinger equation. We shall prove that the Planck's constant, present in the momentum operator of the Schrödinger equation, is deeply related with the ubiquitous zero-point electromagnetic radiation with spectral distribution ρ 0( ω). For simplicity, we do not use the hypothesis of the existence of the L. de Broglie matter-waves. The implications of our study for the standard interpretation of the photoelectric effect are discussed by considering the main characteristics of the phenomenon. We also mention, briefly, the effects of the zero-point radiation in the tunneling phenomenon and the Compton's effect.

  9. Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma

    OpenAIRE

    P. Fischer; Gauthereau, C.; Godiot, J.; G. Matthieussent

    1987-01-01

    An electromagnetic wave ( f = 9 GHz, Pi = 150 kW, τ = 1.5 μs) is launched into a subcritical argon plasma (n e ≃1011 cm-3, P0 ≃ 5 × 10-4 Torr), resulting in a standing wave. The associated ponderomotive force generates an ion acoustic wave with a wave vector equal to twice the electromagnetic one and with a frequency satisfying the usual dispersion relation (fA ≃ 150 kHz). The main features of the ion acoustic wave, as measured in this 3D experiment, agree with a simple theory. However, varyi...

  10. Electromagnetic radiation of charged particles in stochastic motion

    Science.gov (United States)

    Harko, Tiberiu; Mocanu, Gabriela

    2016-03-01

    The study of the Brownian motion of a charged particle in electric and magnetic fields has many important applications in plasma and heavy ions physics, as well as in astrophysics. In the present paper we consider the electromagnetic radiation properties of a charged non-relativistic particle in the presence of electric and magnetic fields, of an exterior non-electromagnetic potential, and of a friction and stochastic force, respectively. We describe the motion of the charged particle by a Langevin and generalized Langevin type stochastic differential equation. We investigate in detail the cases of the Brownian motion with or without memory in a constant electric field, in the presence of an external harmonic potential, and of a constant magnetic field. In all cases the corresponding Langevin equations are solved numerically, and a full description of the spectrum of the emitted radiation and of the physical properties of the motion is obtained. The power spectral density of the emitted power is also obtained for each case, and, for all considered oscillating systems, it shows the presence of peaks, corresponding to certain intervals of the frequency.

  11. The modulation of electromagnetic ion cyclotron waves by Pc 5 ULF waves

    Directory of Open Access Journals (Sweden)

    T. M. Loto'aniu

    2009-01-01

    Full Text Available The modulation of electromagnetic ion cyclotron (EMIC waves by longer-period ULF waves has been proposed as a method for producing pearl structured Pc 1–2 EMIC waves. This study examines frequency and phase relationship between Pc 1 EMIC wavepacket envelopes and simultaneously occurring Pc 5 ULF waves using magnetic data measured by the CRRES spacecraft. Intervals from three days in 1991 where CRRES observed pearls are presented along with simple statistics for 58 EMIC wavepackets. The observations were dominated by EMIC waves propagating away from the equatorial region. Comparisons between pearl wavepacket envelopes and Pc 5 waves show excellent agreement. The pearl wavepacket duration times, τdur, were statistically correlated with Pc 5 wave periods, TPc5, resulting in a correlation coefficient of R=0.7 and best fit equation τdur=0.8·TPc5+6 s. In general, phase differences varied although time intervals of constant in-phase or anti-phase correlation were observed. Anti-phase modulation may be explained by a decreasing background magnetic field due to the negative cycle of the ULF wave decreasing Alfvén velocity and minimum resonant energy. In-phase modulation could be the result of adiabatic modulation of temperature anisotropy in-phase with variations in the background field. Non-adiabatic processes may contribute to intervals that showed varying phase differences with time. Results suggest that future theoretical developments should take into account the full range of possible wave particle interactions inside the magnetosphere.

  12. A New Agile Radiating System Called Electromagnetic Band Gap Matrix Antenna

    Directory of Open Access Journals (Sweden)

    Hussein Abou Taam

    2014-01-01

    Full Text Available Civil and military applications are increasingly in need for agile antenna devices which respond to wireless telecommunications, radars, and electronic warfare requirements. The objective of this paper is to design a new agile antenna system called electromagnetic band gap (EBG matrix. The working principle of this antenna is based on the radiating aperture theory and constitutes the subject of an accepted CNRS patent. In order to highlight the interest and the originality of this antenna, we present a comparison between it and a classical patch array only for the (one-dimensional 1D configuration by using a rigorous full wave simulation (CST Microwave software. In addition, EBG matrix antenna can be controlled by specific synthesis algorithms. These algorithms use inside their; optimization loop an analysis procedure to evaluate the radiation pattern. The analysis procedure is described and validated at the end of this paper.

  13. Effect of Ring Current Ions on Electromagnetic Ion Cyclotron Wave Dispersion Relation

    Science.gov (United States)

    Gamayunov, K. V.; Khazanov, G. V.

    2006-01-01

    Electromagnetic ion cyclotron (EMIC) waves are widely observed in the inner and outer magnetosphere, at geostationary orbit, at high latitudes along the plasmapause, and at the ionospheric altitudes. Interaction of the Ring Current (RC) ions and EMIC waves causes ion scattering into the loss cone and leads to decay of the RC, especially during the main phase of storms when the RC decay times of about one hour or less are observed. The oblique EMIC waves damp due to Landau resonance with the thermal plasmaspheric electrons, and subsequent transport of the dissipating wave energy into the ionosphere below causes an ionosphere temperature enhancement. Induced scattering of these waves by the plasmaspheric thermal ions leads to ion temperature enhancement, and forms a so-called hot zone near the plasmapause where the temperature of core plasma ions can reach tens of thousands of degrees. Relativistic electrons in the outer radiation belt also interact well with the EMIC waves, and during the main and/or recovery phases of the storms these electrons can easily be scattered into the loss cone over a time scale from several hours to a day. The plasma density distribution in the magnetosphere and the ion content play a critical role in EMIC wave generation and propagation, but the wave dispersion relation in the known RC-EMIC wave interaction models is assumed to be determined by the thermal plasma distribution only. In these models, the modification of the EMIC wave dispersion relation caused by the RC ions is not taken into account, and the RC ions are only treated as a source of free energy in order to generate EMIC waves. At the same time, the RC ions can dominate the thermal magnetospheric content in the night MLT sector at great L shells during the main and/or recovery storm phase. In this study, using our self-consistent RC-EMIC wave model [Khazanov et al., 2006], we simulate the May 1998 storm in order to quantify the global EMIC wave redistribution caused by

  14. Generating surface states in a Weyl semimetal by applying electromagnetic radiation

    Science.gov (United States)

    Deb, Oindrila; Sen, Diptiman

    2017-04-01

    We show that the application of circularly polarized electromagnetic radiation on the surface of a Weyl semimetal can generate states at that surface. These states can be characterized by their surface momentum. The Floquet eigenvalues ei θ of these states come in complex conjugate pairs rather than being equal to ±1 . If the amplitude of the radiation is small, we find some unusual bulk-boundary relations: the values of θ of the surface states lie at the extrema of the θ 's of the bulk system, and the peaks of the Fourier transforms of the surface state wave functions lie at the momenta where the bulk θ 's have extrema. For the case of zero surface momentum, we can analytically derive scaling relations between the decay length of the surface states and the amplitude and penetration length of the radiation. For topological insulators, we again find that circularly polarized radiation can generate states on the top surface; these states have much larger decay lengths than the surface states which are present even in the absence of radiation. Finally, we show that radiation can generate surface states for trivial insulators also.

  15. Damping and scattering of electromagnetic waves by small ferrite spheres suspended in an insulator

    Science.gov (United States)

    Englert, Gerald W.

    1992-01-01

    The intentional degradation of electromagnetic waves by their penetration into a media comprised of somewhat sparsely distributed energy absorbing ferrite spheres suspended in an electrical insulator is investigated. Results are presented in terms of generalized parameters involving wave length and sphere size, sphere resistivity, permeability, and spacing; their influence on dissipation of wave power by eddy currents, magnetic hysteresis, and scattering is shown.

  16. Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts.

    Science.gov (United States)

    Shprits, Yuri Y; Drozdov, Alexander Y; Spasojevic, Maria; Kellerman, Adam C; Usanova, Maria E; Engebretson, Mark J; Agapitov, Oleksiy V; Zhelavskaya, Irina S; Raita, Tero J; Spence, Harlan E; Baker, Daniel N; Zhu, Hui; Aseev, Nikita A

    2016-09-28

    The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) distribution of electrons up to ultra-relativistic energies. Here we show that although relativistic electrons are enhanced, ultra-relativistic electrons become depleted and distributions of particles show very clear telltale signatures of electromagnetic ion cyclotron wave-induced loss. Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra-relativistic radiation belt fluxes.

  17. 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...

  18. Diodelike asymmetric transmission of linearly polarized waves using magnetoelectric coupling and electromagnetic wave tunneling.

    Science.gov (United States)

    Mutlu, Mehmet; Akosman, Ahmet E; Serebryannikov, Andriy E; Ozbay, Ekmel

    2012-05-25

    An asymmetric, reciprocal, diffraction-free transmission of linearly polarized waves in a new diodelike, three-layer, ultrathin, chiral structure is studied theoretically and experimentally. The exploited physical mechanism is based on the maximization of the cross-polarized transmission in one direction due to the polarization selectivity dictated by the peculiar eigenstate combination, which is efficiently controlled by the electromagnetic tunneling through the metallic subwavelength mesh sandwiched between these layers. Simulation and microwave experiment results demonstrate a nearly total intensity transmission at normal incidence in one direction and a small intensity transmission in the opposite direction.

  19. Electromagnetic Wave Absorbing Technique Using Periodic Patterns for Low RCS Patch Array Antenna

    Science.gov (United States)

    Jang, Hong-Kyu; Lee, Yeon-Gwan; Shin, Jae-Hwan; Kim, Chun-Gon

    2013-07-01

    This paper presents an electromagnetic wave absorbing technique to reduce a radar cross-section (RCS) of a patch array antenna without compromising their antenna performance. The technique is based on periodic patterns, which is made of resistive materials. The 2×2 patch array antenna with a resonance frequency of 3.0 GHz was designed and fabricated. To reduce the RCS of the patch array antenna, the periodic patterns using a square patch element were proposed and applied to the surface between the four antenna patches. The printed lossy periodic patterns have radar absorbing performance at 12.0 GHz frequency. The measured results show that the lossy periodic patterns have no significant effect on the antenna radiation performance. On the other hand, the RCS is reduced by more than 98% compared to the conventional antenna at the target frequency.

  20. Effects of Electromagnetic Radiation Exposure on Stress-Related Behaviors and Stress Hormones in Male Wistar Rats

    Science.gov (United States)

    Mahdavi, Seyed Mohammad; Sahraei, Hedayat; Yaghmaei, Parichehreh; Tavakoli, Hassan

    2014-01-01

    Studies have demonstrated that electromagnetic waves, as the one of the most important physical factors, may alter cognitive and non-cognitive behaviors, depending on the frequency and energy. Moreover, non-ionizing radiation of low energy waves e.g. very low frequency waves could alter this phenomenon via alterations in neurotransmitters and neurohormones. In this study, short, medium, and long-term exposure to the extremely low frequency electromagnetic field (ELF-EMF) (1 and 5 Hz radiation) on behavioral, hormonal, and metabolic changes in male Wistar rats (250 g) were studied. In addition, changes in plasma concentrations for two main stress hormones, noradrenaline and adrenocorticotropic hormone (ACTH) were evaluated. ELF-EMF exposure did not alter body weight, and food and water intake. Plasma glucose level was increased and decreased in the groups which exposed to the 5 and 1Hz wave, respectively. Plasma ACTH concentration increased in both using frequencies, whereas nor-adrenaline concentration showed overall reduction. At last, numbers of rearing, sniffing, locomotor activity was increased in group receiving 5 Hz wave over the time. In conclusions, these data showed that the effects of 1 and 5 Hz on the hormonal, metabolic and stress-like behaviors may be different. Moreover, the influence of waves on stress system is depending on time of exposure. PMID:25489427

  1. Effects of electromagnetic radiation exposure on stress-related behaviors and stress hormones in male wistar rats.

    Science.gov (United States)

    Mahdavi, Seyed Mohammad; Sahraei, Hedayat; Yaghmaei, Parichehreh; Tavakoli, Hassan

    2014-11-01

    Studies have demonstrated that electromagnetic waves, as the one of the most important physical factors, may alter cognitive and non-cognitive behaviors, depending on the frequency and energy. Moreover, non-ionizing radiation of low energy waves e.g. very low frequency waves could alter this phenomenon via alterations in neurotransmitters and neurohormones. In this study, short, medium, and long-term exposure to the extremely low frequency electromagnetic field (ELF-EMF) (1 and 5 Hz radiation) on behavioral, hormonal, and metabolic changes in male Wistar rats (250 g) were studied. In addition, changes in plasma concentrations for two main stress hormones, noradrenaline and adrenocorticotropic hormone (ACTH) were evaluated. ELF-EMF exposure did not alter body weight, and food and water intake. Plasma glucose level was increased and decreased in the groups which exposed to the 5 and 1Hz wave, respectively. Plasma ACTH concentration increased in both using frequencies, whereas nor-adrenaline concentration showed overall reduction. At last, numbers of rearing, sniffing, locomotor activity was increased in group receiving 5 Hz wave over the time. In conclusions, these data showed that the effects of 1 and 5 Hz on the hormonal, metabolic and stress-like behaviors may be different. Moreover, the influence of waves on stress system is depending on time of exposure.

  2. 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.

  3. 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

  4. 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...

  5. Current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation

    Directory of Open Access Journals (Sweden)

    N Hatefi Kargan

    2013-09-01

    Full Text Available  In this paper, current-voltage characteristic of a resonant tunneling diode under electromagnetic radiation has been calculated and compared with the results when there is no electromagnetic radiation. For calculating current -voltage characteristic, it is required to calculate the transmission coefficient of electrons from the well and barrier structures of this device. For calculating the transmission coefficient of electrons at the presence of electromagnetic radiation, Finite Difference Time Domain (FDTD method has been used and when there is no electromagnetic radiation Transfer Matrix Method (TMM and finite diffirence time domain method have been used. The results show that the presence of electromagnetic radiation causes resonant states other than principal resonant state (without presence of electromagnetic radiation to appear on the transmition coefficient curve where they are in distances from the principal peak and from each other. Also, the presence of electromagnetic radiation causes peaks other than principal peak to appear on the current-voltage characteristics of the device. Under electromagnetic radiation, the number of peaks on the current-voltage curve is smaller than the number of peaks on the current-voltage transmission coefficient. This is due to the fact that current-voltage curve is the result of integration on the energy of electrons, Thus, the sharper and low height peaks on the transmission coefficient do not appear on the current-voltage characteristic curve.

  6. Scattering of Electromagnetic Radiation by Apertures: II. Oblique Incidence on the Slotted Plane for Parallel Polarization,

    Science.gov (United States)

    The report is the second in a series of investigations into the diffraction of electromagnetic radiation by apertures in conducting screens. Herein...is presented a technique for obtaining the fields everywhere for plane electromagnetic radiation incident obliquely on a slotted conducting plane. The

  7. Storage and retrieval of electromagnetic waves with orbital angular momentum via plasmon-induced transparency.

    Science.gov (United States)

    Bai, Zhengyang; Xu, Datang; Huang, Guoxiang

    2017-01-23

    We propose a scheme to realize the storage and retrieval of high-dimensional electromagnetic waves with orbital angular momentum (OAM) via plasmon-induced transparency (PIT) in a metamaterial, which consists of an array of meta-atoms constructed by a metallic structure loaded with two varactors. We show that due to PIT effect the system allows the existence of shape-preserving dark-mode plasmonic polaritons, which are mixture of electromagnetic-wave modes and dark oscillatory modes of the meta-atoms and may carry various OAMs. We demonstrate that the slowdown, storage and retrieval of multi-mode electromagnetic waves with OAMs can be achieved through the active manipulation of a control field. Our work raises the possibility for realizing PIT-based spatial multi-mode memory of electromagnetic waves and is promising for practical application of information processing with large capacity by using room-temperature metamaterials.

  8. Attenuation of an electromagnetic wave by charged dust particles in a sandstorm.

    Science.gov (United States)

    Xie, Li; Li, Xingcai; Zheng, Xiaojing

    2010-12-10

    We calculate the light scattering properties of the partially charged dust particles with the Mie theory for electromagnetic waves with different frequencies, and the attenuation coefficients of an electromagnetic wave propagating in a sandstorm are also calculated. The results show that the electric charges distributed on the sand surface have a significant effect on the attenuation of the electromagnetic wave, especially for a frequency lower than 40 GHz, and attenuation coefficients increase with the magnitude of charges carried by the dust particles (expressed by the charge-to-mass ratio in this paper). For the higher frequency electromagnetic wave, such as visible light, the effect of charges carried by sand particles on its attenuation is very little, which can be ignored.

  9. Reduced Graphene Oxide Functionalized with Cobalt Ferrite Nanocomposites for Enhanced Efficient and Lightweight Electromagnetic Wave Absorption

    National Research Council Canada - National Science Library

    Ding, Yi; Liao, Qingliang; Liu, Shuo; Guo, Huijing; Sun, Yihui; Zhang, Guangjie; Zhang, Yue

    2016-01-01

    ...) as a novel type of electromagnetic wave (EW) absorbing materials was successfully prepared by a three-step chemical method including hydrothermal synthesis, annealing process and mixing with paraffin...

  10. Modulation of coherence of vectorial electromagnetic waves in the Young interferometer.

    Science.gov (United States)

    Luis, Alfredo

    2008-07-01

    We show the modulation of coherence for vectorial electromagnetic waves taking place in the interference plane of a Young interferometer. The amplitude of modulation is determined by the polarization properties at the slits.

  11. Exact solutions of the Heisenberg equations of the relativistic electron in an external electromagnetic wave

    Energy Technology Data Exchange (ETDEWEB)

    Barut, A.O. (Colorado Univ., Boulder (USA). Dept. of Physics); Oezaltin, O.; Uenal, N. (Dicle Univ., Diyarbakir (Turkey). Dept. of Physics)

    1985-01-01

    The Heisenberg equations for the Dirac electron in an external electromagnetic plane wave have been solved exactly in terms of incomplete ..gamma..-functions. As a special case the solution for a crossed constant electric and magnetic field is given.

  12. Scattering of Electromagnetic Waves by Many Nano-Wires

    Directory of Open Access Journals (Sweden)

    Alexander G. Ramm

    2013-07-01

    Full Text Available Electromagnetic wave scattering by many parallel to the z−axis, thin, impedance, parallel, infinite cylinders is studied asymptotically as a → 0. Let Dm be the cross-section of the m−th cylinder, a be its radius and xˆm = (xm1, xm2 be its center, 1 ≤ m ≤ M , M =   M (a. It is assumed that the points, xˆm, are distributed, so that N (∆  = (1 / 2πa * ∫∆ N (xˆdxˆ[1 + o(1], where N (∆ is the number of points, xˆm, in an arbitrary open subset, ∆, of the plane, xoy. The function, N (xˆ ≥ 0, is a continuous function, which an experimentalist can choose. An equation for the self-consistent (effective field is derived as a → 0. A formula is derived for the refraction coefficient in the medium in which many thin impedance cylinders are distributed. These cylinders may model nano-wires embedded in the medium. One can produce a desired refraction coefficient of the new medium by choosing a suitable boundary impedance of the thin cylinders and their distribution law.

  13. Impact of Mobile Phone Electromagnetic Waves on Brainwaves

    Directory of Open Access Journals (Sweden)

    Fu-Chien Kao

    2015-07-01

    Full Text Available In the era of wireless communication, cellular phone becomes an indispensable accessory to most people. People use cellular phone to interact with others, perform commercial and financial transactions, or conducting recreational activities, etc. The advance in wireless technology and escalate of broadband networks not only flourish communications industry and application service providers but also encourage people perform prolonged wireless network activities under the risk of over exposing themselves in long term high frequency electromagnetic waves. For example, some people conduct excessive phone-trading activities, as it is necessary to the job, and some people exercise the non-stop e-learning or recreation activities on mobile devices with long hours. However, would prolonged exposure to high frequency EMW environment bring adverse effects on human health? This research from the perspective of cognitive neuroscience investigates the effect of EMW from cellular phone to the energy distribution of human brainwave characteristic band by examine brainwave changes of test subjects when exposing to high frequency EMW environment. Experiment uses left ear and right ear to answer the phone separately. The calling session is divided into three stages: the instant of call connection, during the call, and after the call. On each ear, the brainwave signal of each calling stage is extracted and analyzed. The experiment shows at the instant of call connection stage, resulting maximum EMW strength, having extreme effect on the energy distribution of the human brainwave characteristic band, and causing severe changes on the energy of human brainwave.

  14. Broadband asymmetric transmission of linearly polarized electromagnetic waves based on chiral metamaterial

    Science.gov (United States)

    Stephen, Lincy; Yogesh, N.; Subramanian, V.

    2018-01-01

    The giant optical activity of chiral metamaterials (CMMs) holds great potential for tailoring the polarization state of an electromagnetic (EM) wave. In controlling the polarization state, the aspect of asymmetric transmission (AT), where a medium allows the EM radiation to pass through in one direction while restricting it in the opposite direction, adds additional degrees of freedom such as one-way channelling functionality. In this work, a CMM formed by a pair of mutually twisted slanted complementary metal strips is realized for broadband AT accompanied with cross-polarization (CP) conversion for linearly polarized EM waves. Numerically, the proposed ultra-thin (˜λ/42) CMM shows broadband AT from 8.58 GHz to 9.73 GHz (bandwidth of 1.15 GHz) accompanied with CP transmission magnitude greater than 0.9. The transmission and reflection spectra reveal the origin of the asymmetric transmission as the direction sensitive cross polarization conversion and anisotropic electric coupling occurring in the structure which is then elaborated with the surface current analysis and electric field distribution within the structure. An experiment is carried out to verify the broadband AT based CP conversion of the proposed CMM at microwave frequencies, and a reliable agreement between numerical and experimental results is obtained. Being ultra-thin, the reported broadband AT based CP conversion of the proposed CMM is useful for controlling radiation patterns in non-reciprocal EM devices and communication networks.

  15. 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...

  16. Generating a heated fluid using an electromagnetic radiation-absorbing complex

    Science.gov (United States)

    Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

    2018-01-09

    A vessel including a concentrator configured to concentrate electromagnetic (EM) radiation received from an EM radiation source and a complex configured to absorb EM radiation to generate heat. The vessel is configured to receive a cool fluid from the cool fluid source, concentrate the EM radiation using the concentrator, apply the EM radiation to the complex, and transform, using the heat generated by the complex, the cool fluid to the heated fluid. The complex is at least one of consisting of copper nanoparticles, copper oxide nanoparticles, nanoshells, nanorods, carbon moieties, encapsulated nanoshells, encapsulated nanoparticles, and branched nanostructures. Further, the EM radiation is at least one of EM radiation in an ultraviolet region of an electromagnetic spectrum, in a visible region of the electromagnetic spectrum, and in an infrared region of the electromagnetic spectrum.

  17. Characterization of porous construction materials using electromagnetic radar wave

    Science.gov (United States)

    Lai, Wallace Wai Lok

    This thesis reports the effort of characterizing three porous construction materials (i.e. concrete, asphalt and soils) and the establishment and formulation of novel unified constitutive models by utilizing electromagnetic (EM) radar wave. An important outcome of this research is that the studied materials were assigned successfully into their rightful positions corresponding to the different regimes governed by three EM wave properties and two engineering/geological properties of the materials. The former refers to the real part of complex dielectric permittivity (epsilon'), energy attenuation and peak-frequency drift. The latter refers to porosity and permeability determined with forward models or conventional testing techniques. In soil and asphalt, the material characterization was achieved by a novel inhouse developed method called Cyclic Moisture Variation Technique (CMVT). The technique is termed cyclic because the porous materials were subjected to change from partially saturated states to fully saturated state (i.e. permeation), and vice versa (i.e. de-watering). With CMVT, water was used as an enhancer or a tracer to differentiate the studied materials which are otherwise difficult when they are dry. Soils and asphalt with different textures were characterized by different curve families exhibited in the relationship between epsilon' and degrees of water saturation (SW). In particular, these curve families were divided into three regions: slow-climbing region in very low SW, fast-climbing region in intermediate SW and another slow-climbing region at high S W. When data obtained from the permeation and de-watering cycles was compared, dielectric hysteresis was observed, but rarely reported in the field of ground penetrating radar (GPR). Different curing histories affect both porosity and pore size distribution within mature concrete. By injecting pressurized water into concrete specimens, different concrete curing histories was back-tracked through the

  18. Propagation of electromagnetic waves in a turbulent medium

    Science.gov (United States)

    Canuto, V. M.; Hartke, G. J.

    1986-01-01

    Theoretical modeling of the wealth of experimental data on propagation of electromagnetic radiation through turbulent media has centered on the use of the Heisenberg-Kolmogorov (HK) model, which is, however, valid only for medium to small sized eddies. Ad hoc modifications of the HK model to encompass the large-scale region of the eddy spectrum have been widely used, but a sound physical basis has been lacking. A model for large-scale turbulence that was recently proposed is applied to the above problem. The spectral density of the temperature field is derived and used to calculate the structure function of the index of refraction N. The result is compared with available data, yielding a reasonably good fit. The variance of N is also in accord with the data. The model is also applied to propagation effects. The phase structure function, covariance of the log amplitude, and variance of the log intensity are calculated. The calculated phase structure function is in excellent agreement with available data.

  19. Thermal electromagnetic radiation in heavy-ion collisions

    Science.gov (United States)

    Rapp, R.; van Hees, H.

    2016-08-01

    We review the potential of precise measurements of electromagnetic probes in relativistic heavy-ion collisions for the theoretical understanding of strongly interacting matter. The penetrating nature of photons and dileptons implies that they can carry undistorted information about the hot and dense regions of the fireballs formed in these reactions and thus provide a unique opportunity to measure the electromagnetic spectral function of QCD matter as a function of both invariant mass and momentum. In particular we report on recent progress on how the medium modifications of the (dominant) isovector part of the vector current correlator ( ρ channel) can shed light on the mechanism of chiral symmetry restoration in the hot and/or dense environment. In addition, thermal dilepton radiation enables novel access to a) the fireball lifetime through the dilepton yield in the low invariant-mass window 0.3 GeV ≤ M ≤ 0.7 GeV, and b) the early temperatures of the fireball through the slope of the invariant-mass spectrum in the intermediate-mass region (1.5 GeV < M < 2.5 GeV). The investigation of the pertinent excitation function suggests that the beam energies provided by the NICA and FAIR projects are in a promising range for a potential discovery of the onset of a first-order phase transition, as signaled by a non-monotonous behavior of both low-mass yields and temperature slopes.

  20. Thermal electromagnetic radiation in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, R. [Texas A and M University, Cyclotron Institute and Department of Physics and Astronomy, College Station, TX (United States); Hees, H. van [Goethe-Universitaet Frankfurt, Institut fuer Theoretische Physik, Frankfurt (Germany); Frankfurt Institute of Advanced Studies (FIAS), Frankfurt (Germany)

    2016-08-15

    We review the potential of precise measurements of electromagnetic probes in relativistic heavy-ion collisions for the theoretical understanding of strongly interacting matter. The penetrating nature of photons and dileptons implies that they can carry undistorted information about the hot and dense regions of the fireballs formed in these reactions and thus provide a unique opportunity to measure the electromagnetic spectral function of QCD matter as a function of both invariant mass and momentum. In particular we report on recent progress on how the medium modifications of the (dominant) isovector part of the vector current correlator (ρ channel) can shed light on the mechanism of chiral symmetry restoration in the hot and/or dense environment. In addition, thermal dilepton radiation enables novel access to (a) the fireball lifetime through the dilepton yield in the low invariant-mass window 0.3 GeV ≤ M ≤ 0.7 GeV, and (b) the early temperatures of the fireball through the slope of the invariant-mass spectrum in the intermediate-mass region (1.5 GeV < M < 2.5 GeV). The investigation of the pertinent excitation function suggests that the beam energies provided by the NICA and FAIR projects are in a promising range for a potential discovery of the onset of a first-order phase transition, as signaled by a non-monotonous behavior of both low-mass yields and temperature slopes. (orig.)

  1. Convergence of vector spherical wave expansion method applied to near-field radiative transfer.

    Science.gov (United States)

    Sasihithlu, Karthik; Narayanaswamy, Arvind

    2011-07-04

    Near-field radiative transfer between two objects can be computed using Rytov's theory of fluctuational electrodynamics in which the strength of electromagnetic sources is related to temperature through the fluctuation-dissipation theorem, and the resultant energy transfer is described using the dyadic Green's function of the vector Helmholtz equation. When the two objects are spheres, the dyadic Green's function can be expanded in a series of vector spherical waves. Based on comparison with the convergence criterion for the case of radiative transfer between two parallel surfaces, we derive a relation for the number of vector spherical waves required for convergence in the case of radiative transfer between two spheres. We show that when electromagnetic surface waves are active at a frequency the number of vector spherical waves required for convergence is proportional to Rmax/d when d/Rmax → 0, where Rmax is the radius of the larger sphere, and d is the smallest gap between the two spheres. This criterion for convergence applies equally well to other near-field electromagnetic scattering problems.

  2. Electromagnetic radiation trapped in the magnetosphere above the plasma frequency

    Science.gov (United States)

    Gurnett, D. A.; Shaw, R. R.

    1973-01-01

    An electromagnetic noise band is frequently observed in the outer magnetosphere by the Imp 6 spacecraft at frequencies from about 5 to 20 kHz. This noise band generally extends throughout the region from near the plasmapause boundary to near the magnetopause boundary. The noise typically has a broadband field strength of about 5 microvolts/meter. The noise band often has a sharp lower cutoff frequency at about 5 to 10 kHz, and this cutoff has been identified as the local electron plasma frequency. Since the plasma frequency in the plasmasphere and solar wind is usually above 20 kHz, it is concluded that this noise must be trapped in the low-density region between the plasmapause and magnetopause boundaries. The noise bands often contain a harmonic frequency structure which suggests that the radiation is associated with harmonics of the electron cyclotron frequency.

  3. Warning Method of Coal Bursting Failure Danger by Electromagnetic Radiation

    Directory of Open Access Journals (Sweden)

    Guang-Jian Liu

    2015-01-01

    Full Text Available Electromagnetic radiation (EMR can reflect the stress state and deformation level of coal, yet its warning indexes correlated with coal properties and roof caving is poorly understood. The laboratory observations of EMR effects of coal samples bursting failure and in situ investigations in the process of roof caving are presented in this paper. EMR peak with increasing stress is discussed when the failure of coal samples happens, which provides an explanation to EMR signals positively correlated well with the stress loaded. The linearly increasing relation is also found between EMR intensity and the uniaxial compressive strength, and EMR maximum amplitudes and pulses behave a logarithmic accretion tendency with bursting energy indexes of coal. By in situ investigations, it is well found that EMR amplitude can effectively warn coal deformation and failure based on the critical value 120 mV proposed from experiments.

  4. A metasurface for conversion of electromagnetic radiation to DC

    Directory of Open Access Journals (Sweden)

    Mohamed El Badawe

    2017-03-01

    Full Text Available We present a metasurface electromagnetic energy harvester based on electrically small resonators. An array of 8× 8 cross resonators was designed to operate at 3GHz. Unlike earlier designs of metasurface harvesters where each resonator was connected to a single rectifier or load, in this work the received power by all resonators is channeled to a single rectifier which in turn channels the DC energy to a single 50Ω resistive load. The critical advantage of the proposed structure is maximizing power density per diode which maximizes the diode turn-on time. We show through simulation and measurements that the proposed metasurface harvester provides Radiation to DC conversion efficiency of more than 40%.

  5. Optimal Design of Electromagnetic Acoustic Transducer Used to Generate Lamb Wave

    Directory of Open Access Journals (Sweden)

    Yan LIU

    2014-01-01

    Full Text Available Electromagnetic ultrasonic transducer is the core component of the electromagnetic ultrasonic testing equipment. This paper establishes a three-dimensional model of the electromagnetic ultrasonic transducer used to generate Lamb wave, then by uniform design experiment and finite element analysis, the paper obtains the law between the eddy current density, the conductor width, length of the coil, the lift off distance, and the permanent magnets thickness. The law is verified by the experiment. It provides an overall principle for the optimal design of electromagnetic ultrasonic transducer.

  6. Broadband low‐frequency electromagnetic waves in the inner magnetosphere

    National Research Council Canada - National Science Library

    Chaston, C. C; Bonnell, J. W; Kletzing, C. A; Hospodarsky, G. B; Wygant, J. R; Smith, C. W

    2015-01-01

    A prominent yet largely unrecognized feature of the inner magnetosphere associated with particle injections, and more generally geomagnetic storms, is the occurrence of broadband electromagnetic field...

  7. Effects of chronic exposure to electromagnetic waves on the auditory system.

    Science.gov (United States)

    Özgür, Abdulkadir; Tümkaya, Levent; Terzi, Suat; Kalkan, Yıldıray; Erdivanlı, Özlem Çelebi; Dursun, Engin

    2015-08-01

    The results support that chronic electromagnetic field exposure may cause damage by leading to neuronal degeneration of the auditory system. Numerous researches have been done about the risks of exposure to the electromagnetic fields that occur during the use of these devices, especially the effects on hearing. The aim of this study is to evaluate the effects of the electromagnetic waves emitted by the mobile phones through the electrophysiological and histological methods. Twelve adult Wistar albino rats were included in the study. The rats were divided into two groups of six rats. The study group was exposed to the electromagnetic waves over a period of 30 days. The control group was not given any exposure to the electromagnetic fields. After the completion of the electromagnetic wave application, the auditory brainstem responses of both groups were recorded under anesthesia. The degeneration of cochlear nuclei was graded by two different histologists, both of whom were blinded to group information. The histopathologic and immunohistochemical analysis showed neuronal degeneration signs, such as increased vacuolization in the cochlear nucleus, pyknotic cell appearance, and edema in the group exposed to the electromagnetic fields compared to the control group. The average latency of wave in the ABR was similar in both groups (p > 0.05).

  8. Electromagnetic counterparts to structured jets from gravitational wave detected mergers

    Science.gov (United States)

    Lamb, Gavin P.; Kobayashi, Shiho

    2017-12-01

    We show the peak magnitude for orphan afterglows from the jets of gravitational wave (GW) detected black hole/neutron star - neutron star (BH/NS-NS) mergers highly depend on the jet half-opening angle θj. Short γ-ray bursts (GRBs) with a homogeneous jet structure and θj > 10°, the orphan afterglow viewed at the typical inclination for a GW detected event, 38°, are brighter at optical frequencies than the comparable macronova emission. Structured jets, where the energetics and Lorentz factor Γ vary with angle from the central axis, may have low-Γ components where the prompt emission is suppressed; GW electromagnetic (EM) counterparts may reveal a population of failed-GRB orphan afterglows. Using a Monte Carlo method assuming an NS-NS detection limit we show the fraction of GW-EM counterparts from homogeneous, two-component, power-law structured and Gaussian jets where the variable structure models include a wide low energy and Γ component: for homogeneous jets, with a θj = 6° and typical short GRB parameters, we find r-band magnitude mr ≤ 21 counterparts for ∼13.6 per cent of GW detected mergers; where jet structure extends to a half-opening angle of 25°, two-component jets produce mr ≤ 21 counterparts in ∼30 per cent of GW detected mergers, power-law structured-jets result in ∼37 per cent and Gaussian jets with our parameters ∼13 per cent. We show the features in the light curves from orphan afterglows can be used to indicate the presence of extended structure.

  9. 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.

  10. Elastic metamaterials for tuning circular polarization of electromagnetic waves

    Science.gov (United States)

    Zárate, Yair; Babaee, Sahab; Kang, Sung H.; Neshev, Dragomir N.; Shadrivov, Ilya V.; Bertoldi, Katia; Powell, David A.

    2016-01-01

    Electromagnetic resonators are integrated with advanced elastic material to develop a new type of tunable metamaterial. An electromagnetic-elastic metamaterial able to switch on and off its electromagnetic chiral response is experimentally demonstrated. Such tunability is attained by harnessing the unique buckling properties of auxetic elastic materials (buckliballs) with embedded electromagnetic resonators. In these structures, simple uniaxial compression results in a complex but controlled pattern of deformation, resulting in a shift of its electromagnetic resonance, and in the structure transforming to a chiral state. The concept can be extended to the tuning of three-dimensional materials constructed from the meta-molecules, since all the components twist and deform into the same chiral configuration when compressed. PMID:27320212

  11. Elastic metamaterials for tuning circular polarization of electromagnetic waves.

    Science.gov (United States)

    Zárate, Yair; Babaee, Sahab; Kang, Sung H; Neshev, Dragomir N; Shadrivov, Ilya V; Bertoldi, Katia; Powell, David A

    2016-06-20

    Electromagnetic resonators are integrated with advanced elastic material to develop a new type of tunable metamaterial. An electromagnetic-elastic metamaterial able to switch on and off its electromagnetic chiral response is experimentally demonstrated. Such tunability is attained by harnessing the unique buckling properties of auxetic elastic materials (buckliballs) with embedded electromagnetic resonators. In these structures, simple uniaxial compression results in a complex but controlled pattern of deformation, resulting in a shift of its electromagnetic resonance, and in the structure transforming to a chiral state. The concept can be extended to the tuning of three-dimensional materials constructed from the meta-molecules, since all the components twist and deform into the same chiral configuration when compressed.

  12. Two-dimensional s-polarized solitary waves in plasmas. II. Stability, collisions, electromagnetic bursts, and post-soliton evolution.

    Science.gov (United States)

    Sánchez-Arriaga, G; Lefebvre, E

    2011-09-01

    The dynamics of two-dimensional s-polarized solitary waves is investigated with the aid of particle-in-cell (PIC) simulations. Instead of the usual excitation of the waves with a laser pulse, the PIC code was directly initialized with the numerical solutions from the fluid plasma model. This technique allows the analysis of different scenarios including the theoretical problems of the solitary wave stability and their collision as well as features already measured during laser-plasma experiments such as the emission of electromagnetic bursts when the waves reach the plasma-vacuum interface, or their expansion on the ion time scale, usually named post-soliton evolution. Waves with a single density depression are stable whereas multihump solutions decay to several waves. Contrary to solitons, two waves always interact through a force that depends on their relative phases, their amplitudes, and the distance between them. On the other hand, the radiation pattern at the plasma-vacuum interface was characterized, and the evolution of the diameter of different waves was computed and compared with the "snow plow" model.

  13. Extremely high-frequency electromagnetic radiation enhances neutrophil response to particulate agonists.

    Science.gov (United States)

    Vlasova, Irina I; Mikhalchik, Elena V; Gusev, Alexandr A; Balabushevich, Nadezhda G; Gusev, Sergey A; Kazarinov, Konstantin D

    2018-02-01

    The growing use of extremely high-frequency electromagnetic radiation (EHF EMR) in information and communication technology and in biomedical applications has raised concerns regarding the potential biological impact of millimeter waves (MMWs). Here, we elucidated the effects of MMW radiation on neutrophil activation induced by opsonized zymosan or E. coli in whole blood ex vivo. After agonist addition to blood, two samples were prepared. A control sample was incubated at ambient conditions without any treatment, and a test sample was exposed to EHF EMR (32.9-39.6 GHz, 100 W/m 2 ). We used methods that allowed us to assess the functional status of neutrophils immediately after exposure: oxidant production levels were measured by luminol-dependent chemiluminescence, and morphofunctional changes to neutrophils were observed in blood smears. Results revealed that the response of neutrophils to both agonists was intensified if blood was exposed to MMW radiation for 15 min. Neutrophils were intact in both the control and irradiated samples if no agonist was added to blood before incubation. Similarly, exposing suspensions of isolated neutrophils in plasma to MMW radiation enhanced cell response to both zymosan and E. coli. Heating blood samples was shown to be the primary mechanism underlying enhanced EHF EMR-induced oxidant production by neutrophils in response to particulate agonists. Bioelectromagnetics. 39:144-155, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. [Effects of electromagnetic radiation on health and immune function of operators].

    Science.gov (United States)

    Li, Yan-zhong; Chen, Shao-hua; Zhao, Ke-fu; Gui, Yun; Fang, Si-xin; Xu, Ying; Ma, Zi-jian

    2013-08-01

    To investigate the effects of electromagnetic radiation on the physiological indices and immune function of operators. The general conditions and electromagnetic radiation awareness rate of 205 operators under electromagnetic radiation were evaluated using a self-designed questionnaire. Physical examination, electrocardiography, and routine urine test were performed in these operators. Peripheral blood was collected from the operators under electromagnetic radiation for blood cell counting and biochemical testing, and their peripheral blood lymphocytes were cultured for determination of chromosomal aberrant frequency and micronucleus frequency. The data from these operators (exposure group) were compared with those of 95 ordinary individuals (control group). The chief complaint of giddiness, tiredness, dizziness, and amnesia showed significant differences between the exposure group and control group (P electromagnetic radiation damage was significantly higher in the exposure group than in the control group. The difference in bradycardia was significant between the two groups (P Electromagnetic radiation may lead to the changes in physiological indices, genetic effects, and immune function and affect the health and immune function in operators. The adverse effects are increased as the working years increase. So it is important to strengthen occupational protection of operators under electromagnetic radiation.

  15. Teaching the Common Aspects in Mechanical, Electromagnetic and Quantum Waves at Interfaces and Waveguides

    Science.gov (United States)

    Rojas, R.; Robles, P.

    2011-01-01

    We discuss common features in mechanical, electromagnetic and quantum systems, supporting identical results for the transmission and reflection coefficients of waves arriving perpendicularly at a plane interface. Also, we briefly discuss the origin of special notions such as refractive index in quantum mechanics, massive photons in wave guides and…

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

    Science.gov (United States)

    Smith, Glenn S.

    2012-01-01

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

  17. Electromagnetic Waves with Frequencies Near the Local Proton Gryofrequency: ISEF-3 1 AU Observations

    Science.gov (United States)

    Tsurutani, B.

    1993-01-01

    Low Frequency electromagnetic waves with periods near the local proton gyrofrequency have been detected near 1 AU by the magnetometer onboard ISEE-3. For these 1 AU waves two physical processes are possible: solar wind pickup of nuetral (interstellar?) particles and generation by relativistic electron beams propagating from the Sun.

  18. geometric optics and WKB method for electromagnetic wave propagation in an inhomogeneous plasma near cutoff

    Energy Technology Data Exchange (ETDEWEB)

    Light, Max Eugene [Los Alamos National Laboratory

    2017-04-13

    This report outlines the theory underlying electromagnetic (EM) wave propagation in an unmagnetized, inhomogeneous plasma. The inhomogeneity is given by a spatially nonuniform plasma electron density ne(r), which will modify the wave propagation in the direction of the gradient rne(r).

  19. Condition for far-zone spectral isotropy of an electromagnetic light wave on weak scattering.

    Science.gov (United States)

    Wang, Tao; Zhao, Daomu

    2011-02-01

    The far-zone spectral isotropy of an electromagnetic light wave on scattering has been discussed. It is shown that a sufficient condition for the far-zone spectral isotropy of an electromagnetic light wave on scattering can be expressed by the following two requirements: the two-point correlation function of the dielectric susceptibility of the scattering medium obeys the so-called scaling law, and the normalized spectrum of the incident light wave has the same distribution along the two perpendicular directions.

  20. Finite element analysis of electromagnetic propagation in an absorbing wave guide

    Science.gov (United States)

    Baumeister, Kenneth J.

    1986-01-01

    Wave guides play a significant role in microwave space communication systems. The attenuation per unit length of the guide depends on its construction and design frequency range. A finite element Galerkin formulation has been developed to study TM electromagnetic propagation in complex two-dimensional absorbing wave guides. The analysis models the electromagnetic absorptive characteristics of a general wave guide which could be used to determine wall losses or simulate resistive terminations fitted into the ends of a guide. It is believed that the general conclusions drawn by using this simpler two-dimensional geometry will be fundamentally the same for other geometries.

  1. Living Organisms Coupling to Electromagnetic Radiation Below Thermal Noise

    Science.gov (United States)

    Stolc, Viktor; Freund, Friedemann

    2013-04-01

    Ultralow frequency (ULF) and extremely low frequency (ELF) electromagnetic (EM) radiation is part of the natural environment. Prior to major earthquakes the local ULF and global ELF radiation field is often markedly perturbed. This has detrimental effects on living organisms. We are studying the mechanism of these effects on the biochemical, cellular and organismal levels. The transfer of electrons along the Electron Transfer Chain (ETC) controls the universal reduction-oxidation reactions that are essential for fundamental biochemical processes in living cells. In order for these processes to work properly, the ETC has to maintain some form of synchronization, or coherence with all biochemical reactions in the living cells, including energy production, RNA transcription, and DNA replication. As a consequence of this synchronization, harmful chemical conflict between the reductive and the oxidative partial reactions can be minimized or avoided. At the same time we note that the synchronization allows for a transfer of energy, coherent or interfering, via coupling to the natural ambient EM field. Extremely weak high frequency EM fields, well below the thermal noise level, tuned in frequency to the electron spins of certain steps in the ETC, have already been shown to cause aberrant cell growth and disorientation among plants and animals with respect to the magnetic and gravity vectors. We investigate EM fields over a much wider frequency range, including ULF known to be generated deep in the Earth prior to major earthquakes locally, and ELF known to be fed by lightning discharges, traveling around the globe in the cavity formed between the Earth's surface and the ionosphere. This ULF/ELF radiation can control the timing of the biochemical redox cycle and thereby have a universal effect on physiology of organisms. The timing can even have a detrimental influence, via increased oxidative damage, on the DNA replication, which controls heredity.

  2. Specific electromagnetic effects of microwave radiation on Escherichia coli.

    Science.gov (United States)

    Shamis, Yury; Taube, Alex; Mitik-Dineva, Natasa; Croft, Rodney; Crawford, Russell J; Ivanova, Elena P

    2011-05-01

    The present study investigated the effects of microwave (MW) radiation applied under a sublethal temperature on Escherichia coli. The experiments were conducted at a frequency of 18 GHz and at a temperature below 40°C to avoid the thermal degradation of bacterial cells during exposure. The absorbed power was calculated to be 1,500 kW/m(3), and the electric field was determined to be 300 V/m. Both values were theoretically confirmed using CST Microwave Studio 3D Electromagnetic Simulation Software. As a negative control, E. coli cells were also thermally heated to temperatures up to 40°C using Peltier plate heating. Scanning electron microscopy (SEM) analysis performed immediately after MW exposure revealed that the E. coli cells exhibited a cell morphology significantly different from that of the negative controls. This MW effect, however, appeared to be temporary, as following a further 10-min elapsed period, the cell morphology appeared to revert to a state that was identical to that of the untreated controls. Confocal laser scanning microscopy (CLSM) revealed that fluorescein isothiocyanate (FITC)-conjugated dextran (150 kDa) was taken up by the MW-treated cells, suggesting that pores had formed within the cell membrane. Cell viability experiments revealed that the MW treatment was not bactericidal, since 88% of the cells were recovered after radiation. It is proposed that one of the effects of exposing E. coli cells to MW radiation under sublethal temperature conditions is that the cell surface undergoes a modification that is electrokinetic in nature, resulting in a reversible MW-induced poration of the cell membrane.

  3. [Effect of decimeter polarized electromagnetic radiation on germinating capacity of seeds].

    Science.gov (United States)

    Polevik, N D

    2013-01-01

    The effect of a polarization structure of electromagnetic radiation on the germinating capacity of seeds of such weeds as Green foxtail (Setaria viridis) and Green amaranth (Amaranthus retroflexus) has been studied. Seeds have been exposed to impulse electromagnetic radiation in a frequency of 896 MHz with linear, elliptical right-handed and elliptical left-handed polarizations at different power flux density levels. It is determined that the effect of the right-handed polarized electromagnetic radiation increases and the influence of the left-handed polarized one reduces the germinating capacity of seeds compared to the effect of the linearly polarized electromagnetic radiation. It is shown that the seeds have an amplitude polarization selectivity as evinced by the major effect of the right-handed polarized radiation on seeds. An electrodynamic model as the right-handed elliptically polarized antenna with the given quantity of the ellipticity of polarization is suggested to use in description of this selectivity.

  4. The electromagnetic chirp of a compact binary black hole: a phase template for the gravitational wave inspiral

    OpenAIRE

    Haiman, Zoltán

    2017-01-01

    The gravitational waves (GWs) from a binary black hole (BBH) with masses between 10^4 and 10^7 Msun can be detected with the Laser Interferometer Space Antenna (LISA) once their orbital frequency exceeds 10^-4 - 10^-5 Hz. The binary separation at this stage is approximately a=100 R_g (gravitational radius), and the orbital speed is of order v/c=0.1. We argue that at this stage, the binary will be producing bright electromagnetic (EM) radiation via gas bound to the individual BHs. Both BHs wil...

  5. A Route to Chaotic Behavior of Single Neuron Exposed to External Electromagnetic Radiation.

    Science.gov (United States)

    Feng, Peihua; Wu, Ying; Zhang, Jiazhong

    2017-01-01

    Non-linear behaviors of a single neuron described by Fitzhugh-Nagumo (FHN) neuron model, with external electromagnetic radiation considered, is investigated. It is discovered that with external electromagnetic radiation in form of a cosine function, the mode selection of membrane potential occurs among periodic, quasi-periodic, and chaotic motions as increasing the frequency of external transmembrane current, which is selected as a sinusoidal function. When the frequency is small or large enough, periodic, and quasi-periodic motions are captured alternatively. Otherwise, when frequency is in interval 0.778 electromagnetic radiation. The frequency apparently plays a more important role in determining the system behavior.

  6. Influence of electromagnetic radiation produced by mobile phone on some biophysical blood properties in rats.

    Science.gov (United States)

    El-Bediwi, Abu Bakr; Saad, Mohamed; El-kott, Attall F; Eid, Eman

    2013-04-01

    Effects of electromagnetic radiation produced by mobile phone on blood viscosity, plasma viscosity, hemolysis, Osmotic fragility, and blood components of rats have been investigated. Experimental results show that there are significant change on blood components and its viscosity which affects on a blood circulation due to many body problems. Red blood cells, White blood cells, and Platelets are broken after exposure to electromagnetic radiation produced by mobile phone. Also blood viscosity and plasma viscosity values are increased but Osmotic fragility value decreased after exposure to electromagnetic radiation produced by mobile phone.

  7. Absorption-Dominated Electromagnetic Wave Suppressor Derived from Ferrite-Doped Cross-Linked Graphene Framework and Conducting Carbon.

    Science.gov (United States)

    Biswas, Sourav; Arief, Injamamul; Panja, Sujit Sankar; Bose, Suryasarathi

    2017-01-25

    To minimize electromagnetic (EM) pollution, two key parameters, namely, intrinsic wave impedance matching and intense absorption of incoming EM radiation, must satisfy the utmost requirements. To target these requirements, soft conducting composites consisting of binary blends of polycarbonate (PC) and poly(vinylidene fluoride) (PVDF) were designed with doped multiwalled carbon nanotubes (MWCNTs) and a three-dimensional cross-linked graphene oxide (GO) framework doped with ferrite nanoparticles. The doping of α-MnO2 onto the MWCNTs ensured intrinsic wave impedance matching in addition to providing conducting pathways, and the ferrite-doped cross-linked GO facilitated the enhanced attenuation of the incoming EM radiation. This unique combination of magnetodielectric coupling led to a very high electromagnetic shielding efficiency (SE) of -37 dB at 18 GHz, dominated by absorption-driven shielding. The promising results from the composites further motivated us to rationally stack individual composites into a multilayer architecture following an absorption-multiple reflection-absorption pathway. This resulted in an impressive SE of -57 dB for a thin shield of 0.9-mm thickness. Such a high SE indicates >99.999% attenuation of the incoming EM radiation, which, together with the improvement in structural properties, validates the potential of these materials in terms of applications in cost-effective and tunable solutions.

  8. Ion hole formation and nonlinear generation of electromagnetic ion cyclotron waves: THEMIS observations

    Science.gov (United States)

    Shoji, Masafumi; Miyoshi, Yoshizumi; Katoh, Yuto; Keika, Kunihiro; Angelopoulos, Vassilis; Kasahara, Satoshi; Asamura, Kazushi; Nakamura, Satoko; Omura, Yoshiharu

    2017-09-01

    Electromagnetic plasma waves are thought to be responsible for energy exchange between charged particles in space plasmas. Such an energy exchange process is evidenced by phase space holes identified in the ion distribution function and measurements of the dot product of the plasma wave electric field and the ion velocity. We develop a method to identify ion hole formation, taking into consideration the phase differences between the gyromotion of ions and the electromagnetic ion cyclotron (EMIC) waves. Using this method, we identify ion holes in the distribution function and the resulting nonlinear EMIC wave evolution from Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations. These ion holes are key to wave growth and frequency drift by the ion currents through nonlinear wave-particle interactions, which are identified by a computer simulation in this study.

  9. Expansion of arbitrary electromagnetic fields in terms of vector spherical wave functions.

    Science.gov (United States)

    Moreira, Wendel Lopes; Neves, Antonio Alvaro Ranha; Garbos, Martin K; Euser, Tijmen G; Cesar, Carlos Lenz

    2016-02-08

    Since 1908, when Mie reported analytical expressions for the fields scattered by a spherical particle upon incidence of plane-waves, generalizing his analysis for the case of an arbitrary incident wave has been an open question because of the cancellation of the prefactor radial spherical Bessel function. This cancellation was obtained before by our own group for a highly focused beam centered in the objective. In this work, however, we show for the first time how these terms can be canceled out for any arbitrary incident field that satisfies Maxwells equations, and obtain analytical expressions for the beam shape coefficients. We show several examples on how to use our method to obtain analytical beam shape coefficients for: Bessel beams, general hollow waveguide modes and specific geometries such as cylindrical and rectangular. Our method uses the vector potential, which shows the interesting characteristic of being gauge invariant. These results are highly relevant for speeding up numerical calculation of light scattering applications such as the radiation forces acting on spherical particles placed in an arbitrary electromagnetic field, as in an optical tweezers system.

  10. Electromagnetic backscattering from one-dimensional drifting fractal sea surface I: Wave-current coupled model

    Science.gov (United States)

    Tao, Xie; Shang-Zhuo, Zhao; William, Perrie; He, Fang; Wen-Jin, Yu; Yi-Jun, He

    2016-06-01

    To study the electromagnetic backscattering from a one-dimensional drifting fractal sea surface, a fractal sea surface wave-current model is derived, based on the mechanism of wave-current interactions. The numerical results show the effect of the ocean current on the wave. Wave amplitude decreases, wavelength and kurtosis of wave height increase, spectrum intensity decreases and shifts towards lower frequencies when the current occurs parallel to the direction of the ocean wave. By comparison, wave amplitude increases, wavelength and kurtosis of wave height decrease, spectrum intensity increases and shifts towards higher frequencies if the current is in the opposite direction to the direction of ocean wave. The wave-current interaction effect of the ocean current is much stronger than that of the nonlinear wave-wave interaction. The kurtosis of the nonlinear fractal ocean surface is larger than that of linear fractal ocean surface. The effect of the current on skewness of the probability distribution function is negligible. Therefore, the ocean wave spectrum is notably changed by the surface current and the change should be detectable in the electromagnetic backscattering signal. Project supported by the National Natural Science Foundation of China (Grant No. 41276187), the Global Change Research Program of China (Grant No. 2015CB953901), the Priority Academic Development Program of Jiangsu Higher Education Institutions (PAPD), Program for the Innovation Research and Entrepreneurship Team in Jiangsu Province, China, the Canadian Program on Energy Research and Development, and the Canadian World Class Tanker Safety Service.

  11. Excitation of Surface Electromagnetic Waves on Railroad Rail

    Science.gov (United States)

    1978-03-31

    UMTA's Office of Rail Technology research programs aim to improve urban rail transportation systems safety. This rail-transit research study attempts to develop an onboard, separate and independent obstacle-detection system--Surface Electromagnetic W...

  12. Absorbing boundary conditions for low group velocity electromagnetic waves in photonic crystals.

    Science.gov (United States)

    Askari, Murtaza; Momeni, Babak; Reinke, Charles M; Adibi, Ali

    2011-03-20

    We present an efficient method for the absorption of slow group velocity electromagnetic waves in photonic crystal waveguides (PCWs). We show that adiabatically matching the low group velocity waves to high group velocity waves of the PCW and extending the PCW structure into the perfectly matched layer (PML) region results in a 15 dB reduction of spurious reflections from the PML. We also discuss the applicability of this method to structures other than PCWs.

  13. Modulation of a compressional electromagnetic wave in a magnetized electron-positron quantum plasma.

    Science.gov (United States)

    Amin, M R

    2015-09-01

    Amplitude modulation of a compressional electromagnetic wave in a strongly magnetized electron-positron pair plasma is considered in the quantum magnetohydrodynamic regime. The important ingredients of this study are the inclusion of the external strong magnetic field, Fermi quantum degeneracy pressure, particle exchange potential, quantum diffraction effects via the Bohm potential, and dissipative effect due to collision of the charged carriers. A modified-nonlinear Schödinger equation is developed for the compressional magnetic field of the electromagnetic wave by employing the standard reductive perturbation technique. The linear and nonlinear dispersions of the electromagnetic wave are discussed in detail. For some parameter ranges, relevant to dense astrophysical objects such as the outer layers of white dwarfs, neutron stars, and magnetars, etc., it is found that the compressional electromagnetic wave is modulationally unstable and propagates as a dissipated electromagnetic wave. It is also found that the quantum effects due to the particle exchange potential and the Bohm potential are negligibly small in comparison to the effects of the Fermi quantum degeneracy pressure. The numerical results on the growth rate of the modulation instability is also presented.

  14. Millimeter-Wave Power-Combining with Radiating Oscillator Arrays.

    Science.gov (United States)

    York, Robert Armstrong

    The next generation of communications and radar systems will soon begin to exploit the millimeter-wave portion of the electromagnetic spectrum. Such systems will require a high-power source of millimeter-wave energy, ideally small, lightweight, highly efficient, and failure -proof over a span of decades. Circuits using semiconductor devices have proved useful for this purpose at lower frequencies, but unfortunately the power generating capacity of solid -state devices diminishes quickly as frequencies approach 100 GHz. This has forced designers to use bulky, inefficient, and unreliable (but high-power) vacuum-tube sources. Combining the power produced by a large number of individual solid-state devices has been suggested as a means of overcoming the inherent limitations of millimeter -wave devices. In order to compete with vacuum-tube sources, power-combiners would require up to 1000 devices, presenting a difficult engineering challenge. This thesis introduces one possible solution to this problem. The proposed concept uses arrays of millimeter-wave oscillators, where each oscillator contains one or more active devices in a planar radiating structure. The oscillators are weakly coupled to synchronize frequency and phase relationships, and the power produced by each oscillator is radiatively combined in free-space, which gives rise to very high combining efficiencies. The array concept has been demonstrated at microwave frequencies using both Gunn and MESFET devices in a 4 x 4 patch antenna configuration. The Gunn array produced 22 Watts Equivalent Radiated Power (ERP), and the MESFET array produced 10 Watts ERP. A new theory has been developed which describes the coupled-oscillator dynamics, and has been shown to accurately predict experimentally observed effects. In addition to strict CW power-combining, a new mode of operation has been discovered which enables the same arrays to generate high-power pulses of energy. This new effect involves a "mode

  15. Channeling and electromagnetic radiation of relativistic charged particles in metal-organic frameworks

    Science.gov (United States)

    Zhevago, N. K.; Glebov, V. I.

    2017-06-01

    We have developed the theory of electromagnetic interaction of relativistic charged particles with metal-organic frameworks (MOFs). The electrostatic potential and electron number density distribution in MOFs were calculated using the most accurate data for the atomic form factors. Peculiarities of axial channeling of fast charged particles and various types of electromagnetic radiation from relativistic particles has been discussed.

  16. Precipitation of radiation belt electrons by EMIC waves, observed from ground and space

    Energy Technology Data Exchange (ETDEWEB)

    Jordanova, Vania K [Los Alamos National Laboratory; Miyoski, Y [NAGOYA UNIV; Sakaguchi, K [NAGOYA UNIV; Shiokawa, K [NAGOYA UNIV; Evans, D S [NOAA, BOULDER; Albert, Jay [AFRL; Connors, M [UNIV OF ATHABASCA

    2008-01-01

    We show evidence that left-hand polarised electromagnetic ion cyclotron (EMIC) plasma waves can cause the loss of relativistic electrons into the atmosphere. Our unique set of ground and satellite observations shows coincident precipitation of ions with energies of tens of keY and of relativistic electrons into an isolated proton aurora. The coincident precipitation was produced by wave-particle interactions with EMIC waves near the plasmapause. The estimation of pitch angle diffusion coefficients supports that the observed EMIC waves caused coincident precipitation ofboth ions and relativistic electrons. This study clarifies that ions with energies of tens of ke V affect the evolution of relativistic electrons in the radiation belts via cyclotron resonance with EMIC waves, an effect that was first theoretically predicted in the early 1970's.

  17. Radiative transfer of acoustic waves in continuous complex media: Beyond the Helmholtz equation

    CERN Document Server

    Baydoun, Ibrahim; Pierrat, Romain; Derode, Arnaud

    2016-01-01

    Heterogeneity can be accounted for by a random potential in the wave equation. For acoustic waves in a fluid with fluctuations of both density and compressibility (as well as for electromagnetic waves in a medium with fluctuation of both permittivity and permeability) the random potential entails a scalar and an operator contribution. For simplicity, the latter is usually overlooked in multiple scattering theory: whatever the type of waves, this simplification amounts to considering the Helmholtz equation with a sound speed $c$ depending on position $\\mathbf{r}$. In this work, a radiative transfer equation is derived from the wave equation, in order to study energy transport through a multiple scattering medium. In particular, the influence of the operator term on various transport parameters is studied, based on the diagrammatic approach of multiple scattering. Analytical results are obtained for fundamental quantities of transport theory such as the transport mean-free path $\\ell^*$, scattering phase functi...

  18. The effects of radiofrequency electromagnetic radiation on sperm function.

    Science.gov (United States)

    Houston, B J; Nixon, B; King, B V; De Iuliis, G N; Aitken, R J

    2016-12-01

    Mobile phone usage has become an integral part of our lives. However, the effects of the radiofrequency electromagnetic radiation (RF-EMR) emitted by these devices on biological systems and specifically the reproductive systems are currently under active debate. A fundamental hindrance to the current debate is that there is no clear mechanism of how such non-ionising radiation influences biological systems. Therefore, we explored the documented impacts of RF-EMR on the male reproductive system and considered any common observations that could provide insights on a potential mechanism. Among a total of 27 studies investigating the effects of RF-EMR on the male reproductive system, negative consequences of exposure were reported in 21. Within these 21 studies, 11 of the 15 that investigated sperm motility reported significant declines, 7 of 7 that measured the production of reactive oxygen species (ROS) documented elevated levels and 4 of 5 studies that probed for DNA damage highlighted increased damage due to RF-EMR exposure. Associated with this, RF-EMR treatment reduced the antioxidant levels in 6 of 6 studies that discussed this phenomenon, whereas consequences of RF-EMR were successfully ameliorated with the supplementation of antioxidants in all 3 studies that carried out these experiments. In light of this, we envisage a two-step mechanism whereby RF-EMR is able to induce mitochondrial dysfunction leading to elevated ROS production. A continued focus on research, which aims to shed light on the biological effects of RF-EMR will allow us to test and assess this proposed mechanism in a variety of cell types. © 2016 Society for Reproduction and Fertility.

  19. Speed of Gravitational Waves from Strongly Lensed Gravitational Waves and Electromagnetic Signals

    Science.gov (United States)

    Fan, Xi-Long; Liao, Kai; Biesiada, Marek; Piórkowska-Kurpas, Aleksandra; Zhu, Zong-Hong

    2017-03-01

    We propose a new model-independent measurement strategy for the propagation speed of gravitational waves (GWs) based on strongly lensed GWs and their electromagnetic (EM) counterparts. This can be done in two ways: by comparing arrival times of GWs and their EM counterparts and by comparing the time delays between images seen in GWs and their EM counterparts. The lensed GW-EM event is perhaps the best way to identify an EM counterpart. Conceptually, this method does not rely on any specific theory of massive gravitons or modified gravity. Its differential setting (i.e., measuring the difference between time delays in GW and EM domains) makes it robust against lens modeling details (photons and GWs travel in the same lensing potential) and against internal time delays between GW and EM emission acts. It requires, however, that the theory of gravity is metric and predicts gravitational lensing similar to general relativity. We expect that such a test will become possible in the era of third-generation gravitational-wave detectors, when about 10 lensed GW events would be observed each year. The power of this method is mainly limited by the timing accuracy of the EM counterpart, which for kilonovae is around 1 04 s . This uncertainty can be suppressed by a factor of ˜1 010, if strongly lensed transients of much shorter duration associated with the GW event can be identified. Candidates for such short transients include short γ -ray bursts and fast radio bursts.

  20. Speed of Gravitational Waves from Strongly Lensed Gravitational Waves and Electromagnetic Signals.

    Science.gov (United States)

    Fan, Xi-Long; Liao, Kai; Biesiada, Marek; Piórkowska-Kurpas, Aleksandra; Zhu, Zong-Hong

    2017-03-03

    We propose a new model-independent measurement strategy for the propagation speed of gravitational waves (GWs) based on strongly lensed GWs and their electromagnetic (EM) counterparts. This can be done in two ways: by comparing arrival times of GWs and their EM counterparts and by comparing the time delays between images seen in GWs and their EM counterparts. The lensed GW-EM event is perhaps the best way to identify an EM counterpart. Conceptually, this method does not rely on any specific theory of massive gravitons or modified gravity. Its differential setting (i.e., measuring the difference between time delays in GW and EM domains) makes it robust against lens modeling details (photons and GWs travel in the same lensing potential) and against internal time delays between GW and EM emission acts. It requires, however, that the theory of gravity is metric and predicts gravitational lensing similar to general relativity. We expect that such a test will become possible in the era of third-generation gravitational-wave detectors, when about 10 lensed GW events would be observed each year. The power of this method is mainly limited by the timing accuracy of the EM counterpart, which for kilonovae is around 10^{4}  s. This uncertainty can be suppressed by a factor of ∼10^{10}, if strongly lensed transients of much shorter duration associated with the GW event can be identified. Candidates for such short transients include short γ-ray bursts and fast radio bursts.

  1. Changes in Frequency of Electromagnetic Radiation from Loaded Coal Rock

    Science.gov (United States)

    Song, Dazhao; Wang, Enyuan; Song, Xiaoyan; Jin, Peijian; Qiu, Liming

    2016-01-01

    To understand the relationship between the frequency of electromagnetic radiation (EMR) emitted from loaded coal rock and the micro-crack structures inside it, and assess the stress state and the stability of coal rock by analyzing frequency changes in characteristics of its emitted EMR, we first experimentally studied the changes in time sequence and the frequency spectrum characteristics of EMR during uniaxial compression, then theoretically derived the relationship between the principal frequency of EMR signals and the mechanical parameters of coal crack and analyzed the major factors causing the changes in the principal frequency, and lastly verified the results at Nuodong Coal Mine, Guizhou Province, China. The experimental results showed that (1) EMR intensity increased with the applied stress on loaded coal rock during its deformation and failure and could qualitatively reflect the coal's stress status; (2) with the applied stress increasing, the principal frequency gradually increased from near zero to about 60 kHz and then dropped to less than 20 kHz. During this period, coal rock first stepped into the linearly and elastically deformed stage and then ruptured around the peak load. Theoretical analysis showed that there was a negative correlation between the principle frequency and the size of internal cracks. Field detection showed that a lower principle frequency was generated from coal rock applied by a greater load, while a higher principal frequency was generated from coal rocks suffering a weaker load.

  2. A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

    Science.gov (United States)

    Simoes, Fernando; Pfaff, Robert; Berthelier, Jean-Jacques; Klenzing, Jeffrey

    2012-01-01

    Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms.

  3. Second-harmonic generation of cylindrical electromagnetic waves propagating in an inhomogeneous and nonlinear medium.

    Science.gov (United States)

    Xiong, Hao; Si, Liu-Gang; Ding, Chunling; Yang, Xiaoxue; Wu, Ying

    2012-01-01

    A general description of cylindrical electromagnetic waves propagating in nonlinear and inhomogeneous media is given by deducing cylindrical coupled-wave equations. Based on the cylindrical coupled-wave equations, we analyze second-harmonic generation (SHG) of some special cases of inhomogeneity, and find that the inhomogeneity of the first- and second-order polarization can influence the amplitude of the SHG. From a different point of view, exact solutions of cylindrical electromagnetic waves propagating in a nonlinear medium with a special case of inhomogeneity have been obtained previously. We show that cylindrical SHG in an inhomogeneous and nonlinear medium can also be deduced from exact solutions. As verification, we compare the results obtained from the two different methods and find that descriptions of SHG by the coupled-wave equations are in good agreement with the exact solutions.

  4. Theory of reflection reflection and transmission of electromagnetic, particle and acoustic waves

    CERN Document Server

    Lekner, John

    2016-01-01

    This book deals with the reflection of electromagnetic and particle waves by interfaces. The interfaces can be sharp or diffuse. The topics of the book contain absorption, inverse problems, anisotropy, pulses and finite beams, rough surfaces, matrix methods, numerical methods,  reflection of particle waves and neutron reflection. Exact general results are presented, followed by long wave reflection, variational theory, reflection amplitude equations of the Riccati type, and reflection of short waves. The Second Edition of the Theory of Reflection is an updated and much enlarged revision of the 1987 monograph. There are new chapters on periodically stratified media, ellipsometry, chiral media, neutron reflection and reflection of acoustic waves. The chapter on anisotropy is much extended, with a complete treatment of the reflection and transmission properties of arbitrarily oriented uniaxial crystals. The book gives a systematic and unified treatment reflection and transmission of electromagnetic and particle...

  5. Iterative Computational Scheme of Studying Electromagnetic Wave Propagation through Dielectric Thin Film Medium

    Directory of Open Access Journals (Sweden)

    E Ugwu

    2016-09-01

    Full Text Available We present an approach to the computation of electromagnetic wave propagation through a dielectric thin film medium using iterative scheme. We used the Green's function technique involving some necessary boundary condition to solve the scalar wave equation. Non-vectorial aspects of the propagating wave through the thin film resulting from the film orientation were considered. The iterative numerical scheme based on the parallel use of Lippmann-Schwinger and Dyson's equations is demonstrated and used judiciously in the computation. The influence of the numerical parameters such as Green's function, thickness of the thin film, dielectric perturbation, Δεp(z and mesh size, Np on the propagating wave for three region of electromagnetic wave were clearly assessed.

  6. Parametric study of electromagnetic waves propagating in absorbing curved S ducts

    Science.gov (United States)

    Baumeister, Kenneth J.

    1989-01-01

    A finite-element Galerkin formulation has been developed to study attenuation of transverse magnetic (TM) waves propagating in two-dimensional S-curved ducts with absorbing walls. In the frequency range where the duct diameter and electromagnetic wave length are nearly equal, the effect of duct length, curvature (duct offset), and absorber wall thickness was examined. For a given offset in the curved duct, the length of the S-duct was found to significantly affect both the absorptive and reflective characteristics of the duct. For a straight and a curved duct with perfect electric conductor terminations, power attenuation contours were examined to determine electromagnetic wall properties associated with maximum input signal absorption. Offset of the S-duct was found to significantly affect the value of the wall permittivity associated with the optimal attenuation of the incident electromagnetic wave.

  7. Estimation of Aircraft Attitude/Heading Based on the Polarization of Electromagnetic Waves

    Directory of Open Access Journals (Sweden)

    Sun Hong-mei

    2013-12-01

    Full Text Available This paper illustrates the full use of an orthogonal decoupling signal model to describe the 3-D construction of polarized electromagnetic waves. The maximum likelihood method and MUSIC algorithm were introduced into the parameter estimation of partially polarized waves. Attitude reference information for an aircraft that was calibrated by an information base station was delivered by polarized electromagnetic waves. Through receiving and processing the information of the aircraft, a single electromagnetic vector sensor can acquire the aircraft attitude in a geographic coordinate system. Differing from the triangle calculation method which relies on a multi-point measurement, the proposed method only needs a base station signal and a single receiver on the motion platform to realize the posture perception of aircraft. It can therefore serve as a substitute for aircraft attitude navigation and aircraft heading navigation. The introduction of the motion platform attitude estimation algorithm provides a technology support for engineering applications.

  8. Computational Electromagnetic Studies for Low-Frequency Compensation of the Reflector Impulse-radiating Antenna

    Science.gov (United States)

    2015-03-26

    realized as constant- angular structures, such as biconical and bowtie antennas . Inevitably, the ge- ometry must be truncated at some point, so physical...COMPUTATIONAL ELECTROMAGNETIC STUDIES FOR LOW-FREQUENCY COMPENSATION OF THE REFLECTOR IMPULSE-RADIATING ANTENNA THESIS Casey E. Fillmore, Capt, USAF...ELECTROMAGNETIC STUDIES FOR LOW-FREQUENCY COMPENSATION OF THE REFLECTOR IMPULSE-RADIATING ANTENNA THESIS Presented to the Faculty Department of Electrical and

  9. Electromagnetic crystal based terahertz thermal radiators and components

    Science.gov (United States)

    Wu, Ziran

    This dissertation presents the investigation of thermal radiation from three-dimensional electromagnetic crystals (EMXT), as well as the development of a THz rapid prototyping fabrication technique and its application in THz EMXT components and micro-system fabrication and integration. First, it is proposed that thermal radiation from a 3-D EMXT would be greatly enhanced at the band gap edge frequency due to the redistribution of photon density of states (DOS) within the crystal. A THz thermal radiator could thus be built upon a THz EMXT by utilizing the exceptional emission peak(s) around its band gap frequency. The thermal radiation enhancement effects of various THz EMXT including both silicon and tungsten woodpile structures (WPS) and cubic photonic cavity (CPC) array are explored. The DOS of all three structures are calculated, and their thermal radiation intensities are predicted using Planck's Equation. These calculations show that the DOS of the silicon and tungsten WPS can be enhanced by a factor of 11.8 around 364 GHz and 2.6 around 406 GHz respectively, in comparison to the normal blackbody radiation at same frequencies. An enhancement factor of more than 100 is obtained in calculation from the CPC array. A silicon WPS with a band gap around 200 GHz has been designed and fabricated. Thermal emissivity of the silicon WPS sample is measured with a control blackbody as reference. And enhancements of the emission from the WPS over the control blackbody are observed at several frequencies quite consistent with the theoretical predictions. Second, the practical challenge of THz EMXT component and system fabrication is met by a THz rapid prototyping technique developed by us. Using this technique, the fabrications of several EMXTs with 3D electromagnetic band gaps in the 100-400 GHz range are demonstrated. Characterization of the samples via THz Time-domain Spectroscopy (THz-TDS) shows very good agreement with simulation, confirming the build accuracy of this

  10. Links between extremely high frequency electromagnetic waves and their biological manifestations

    Directory of Open Access Journals (Sweden)

    Anton Emil

    2015-01-01

    Full Text Available In this mini-review, we describe some of the latest facts regarding the generation of condensed base phonons by biological entities, initially described by the renowned contemporary physicist, Nobel laureate, Herbert Fröhlich, who proposed a new biophysical interaction mechanism between extremely high frequency electromagnetic waves and the biological environment. As we will show, this extremely low intensity millimeter therapy crystallizes as an important new method, universal and effective in the management of diseases with different etiologies. Moreover, the existence of internal electromagnetic fields generated by biological entities, as well as external electromagnetic fields, are essential for understanding the electromagnetic-biological effect. In fact, it is estimated that at present millimeter-wave therapy is used for the management of more than 120 diseases in cardiology, neurology, oncology, gynecology, urology, gastroenterology, surgery, pharmacology and pediatrics. However, so far there is still no consensus regarding the interaction between extremely high frequency/extremely low intensity electromagnetic waves and the biological environment at its different levels of organization. Thus, the present paper was intended to contribute to the development for the theory of millimeter-wave interaction with living biological entities.

  11. A statistical model for relativistic quantum fluids interacting with an intense electromagnetic wave

    Science.gov (United States)

    Mahajan, Swadesh M.; Asenjo, Felipe A.

    2016-05-01

    A statistical model for relativistic quantum fluids interacting with an arbitrary amplitude circularly polarized electromagnetic wave is developed in two steps. First, the energy spectrum and the wave function for a quantum particle (Klein Gordon and Dirac) embedded in the electromagnetic wave are calculated by solving the appropriate eigenvalue problem. The energy spectrum is anisotropic in the momentum K and reflects the electromagnetic field through the renormalization of the rest mass m to M =√{m2+q2A2 } . Based on this energy spectrum of this quantum particle plus field combination (QPF), a statistical mechanics model of the quantum fluid made up of these weakly interacting QPF is developed. Preliminary investigations of the formalism yield highly interesting results—a new scale for temperature, and fundamental modification of the dispersion relation of the electromagnetic wave. It is expected that this formulation could, inter alia, uniquely advance our understanding of laboratory as well as astrophysical systems where one encounters arbitrarily large electromagnetic fields.

  12. Electromagnetic Wave Excitation, Propagation, and Absorption in High Current Storage Rings

    Science.gov (United States)

    Novokhatski, A.; Seeman, J.; Sullivan, M.; Wienands, U.

    2016-04-01

    We analyze a variety of electromagnetic effects in storage rings with extremely high currents. Specifically, we discuss our experience in the operation of the PEP-II (SLAC B-factory). We present some outstanding and sometimes unpredictable effects of the behavior of electromagnetic waves excited by intense beams inside a vacuum chamber in storage rings. Although the impedance of the rings is usually designed to be small, intense high-current beams can still generate significant microwave power. This power can be enough to damage vacuum beam chamber elements, which may absorb electromagnetic waves. The most sensitive elements are RF seals, vacuum valves, shielded bellows, beam position monitor buttons, and ceramic tiles. Additionally, microwave heating leads to vacuum pressure spikes or even vacuum pressure instabilities that brings high detector background. Resonance excitation of the electromagnetic field may lead to a very high electric component amplitude that can cause breakdowns leading to sparks and discharges. Finally, high-power electromagnetic waves can be responsible for beam instabilities in the ring. Proper absorption of these generated waves may eliminate these effects. We feel our experience will be helpful in the design of new high current synchrotron light sources and storage rings.

  13. 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.

  14. Expanding the use of real-time electromagnetic tracking in radiation oncology.

    Science.gov (United States)

    Shah, Amish P; Kupelian, Patrick A; Willoughby, Twyla R; Meeks, Sanford L

    2011-11-15

    In the past 10 years, techniques to improve radiotherapy delivery, such as intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT) for both inter- and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applied to various clinical tumor sites indicates that the potential benefits of electromagnetic tracking could be significant for patients receiving radiation therapy. Daily use of these tracking systems is minimally invasive and delivers no additional ionizing radiation to the patient, and these systems can provide explicit tumor motion data. Although there are a number of technical and fiscal issues that need to be addressed, electromagnetic tracking systems are expected to play a continued role in improving the precision of radiation delivery.

  15. Nonlinear Generation of Electromagnetic Waves through Induced Scattering by Thermal Plasma.

    Science.gov (United States)

    Tejero, E M; Crabtree, C; Blackwell, D D; Amatucci, W E; Mithaiwala, M; Ganguli, G; Rudakov, L

    2015-12-09

    We demonstrate the conversion of electrostatic pump waves into electromagnetic waves through nonlinear induced scattering by thermal particles in a laboratory plasma. Electrostatic waves in the whistler branch are launched that propagate near the resonance cone. When the amplitude exceeds a threshold ~5 × 10(-6) times the background magnetic field, wave power is scattered below the pump frequency with wave normal angles (~59°), where the scattered wavelength reaches the limits of the plasma column. The scattered wave has a perpendicular wavelength that is an order of magnitude larger than the pump wave and longer than the electron skin depth. The amplitude threshold, scattered frequency spectrum, and scattered wave normal angles are in good agreement with theory. The results may affect the analysis and interpretation of space observations and lead to a comprehensive understanding of the nature of the Earth's plasma environment.

  16. Adiabatic description of capture into resonance and surfatron acceleration of charged particles by electromagnetic waves.

    Science.gov (United States)

    Artemyev, A V; Neishtadt, A I; Zelenyi, L M; Vainchtein, D L

    2010-12-01

    We present an analytical and numerical study of the surfatron acceleration of nonrelativistic charged particles by electromagnetic waves. The acceleration is caused by capture of particles into resonance with one of the waves. We investigate capture for systems with one or two waves and provide conditions under which the obtained results can be applied to systems with more than two waves. In the case of a single wave, the once captured particles never leave the resonance and their velocity grows linearly with time. However, if there are two waves in the system, the upper bound of the energy gain may exist and we find the analytical value of that bound. We discuss several generalizations including the relativistic limit, different wave amplitudes, and a wide range of the waves' wavenumbers. The obtained results are used for qualitative description of some phenomena observed in the Earth's magnetosphere. © 2010 American Institute of Physics.

  17. Study on the electromagnetic waves propagation characteristics in partially ionized plasma slabs

    Directory of Open Access Journals (Sweden)

    Zhi-Bin Wang

    2016-05-01

    Full Text Available Propagation characteristics of electromagnetic (EM waves in partially ionized plasma slabs are studied in this paper. Such features are significant to applications in plasma antennas, blackout of re-entry flying vehicles, wave energy injection to plasmas, and etc. We in this paper developed a theoretical model of EM wave propagation perpendicular to a plasma slab with a one-dimensional density inhomogeneity along propagation direction to investigate essential characteristics of EM wave propagation in nonuniform plasmas. Particularly, the EM wave propagation in sub-wavelength plasma slabs, where the geometric optics approximation fails, is studied and in comparison with thicker slabs where the geometric optics approximation applies. The influences of both plasma and collisional frequencies, as well as the width of the plasma slab, on the EM wave propagation characteristics are discussed. The results can help the further understanding of propagation behaviours of EM waves in nonuniform plasma, and applications of the interactions between EM waves and plasmas.

  18. PWO crystals for CMS electromagnetic calorimeter studies of the radiation damage kinetics

    CERN Document Server

    Drobychev, G Yu; Dormenev, V; Korzhik, M; Lecoq, P; Lopatic, A; Nédélec, P; Peigneux, J P; Sillou, D

    2005-01-01

    Kinetics of radiation damage of the PWO crystals under irradiation and recovery were studied. Crystals were irradiated with dose corresponding to average one expected in the electromagnetic calorimeter (working dose irradiation). Radiation damage and recovery were monitored through measurements of PWO optical transmission. An approach is proposed which allows evaluating the influence of the PWO crystals properties on the statistical term in the energy resolution of the electromagnetic calorimeter. The analysis also gives important information about the nature of the radiation damage mechanism in scintillation crystals. The method was used during development of technology of the mass production of radiation hard crystals and during development of methods for crystals certification

  19. Electromagnetic Radiation : Variational Methods, Waveguides and Accelerators Including seminal papers of Julian Schwinger

    CERN Document Server

    Milton, Kimball A

    2006-01-01

    This is a graduate level textbook on the theory of electromagnetic radiation and its application to waveguides, transmission lines, accelerator physics and synchrotron radiation. It has grown out of lectures and manuscripts by Julian Schwinger prepared during the war at MIT's Radiation Laboratory, updated with material developed by Schwinger at UCLA in the 1970s and 1980s, and by Milton at the University of Oklahoma since 1994. The book includes a great number of straightforward and challenging exercises and problems. It is addressed to students in physics, electrical engineering, and applied mathematics seeking a thorough introduction to electromagnetism with emphasis on radiation theory and its applications.

  20. Numerical Tests and Properties of Waves in Radiating Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, B M; Klein, R I

    2009-09-03

    We discuss the properties of an analytical solution for waves in radiating fluids, with a view towards its implementation as a quantitative test of radiation hydrodynamics codes. A homogeneous radiating fluid in local thermodynamic equilibrium is periodically driven at the boundary of a one-dimensional domain, and the solution describes the propagation of the waves thus excited. Two modes are excited for a given driving frequency, generally referred to as a radiative acoustic wave and a radiative diffusion wave. While the analytical solution is well known, several features are highlighted here that require care during its numerical implementation. We compare the solution in a wide range of parameter space to a numerical integration with a Lagrangian radiation hydrodynamics code. Our most significant observation is that flux-limited diffusion does not preserve causality for waves on a homogeneous background.

  1. Condition for invariant spectrum of an electromagnetic wave scattered from an anisotropic random media.

    Science.gov (United States)

    Li, Jia; Wu, Pinghui; Chang, Liping

    2015-08-24

    Within the accuracy of the first-order Born approximation, sufficient conditions are derived for the invariance of spectrum of an electromagnetic wave, which is generated by the scattering of an electromagnetic plane wave from an anisotropic random media. We show that the following restrictions on properties of incident fields and the anisotropic media must be simultaneously satisfied: 1) the elements of the dielectric susceptibility matrix of the media must obey the scaling law; 2) the spectral components of the incident field are proportional to each other; 3) the second moments of the elements of the dielectric susceptibility matrix of the media are inversely proportional to the frequency.

  2. Electromagnetic radiation related to dislocation dynamics in a seismic preparation zone

    Directory of Open Access Journals (Sweden)

    T. Ernst

    2002-06-01

    Full Text Available Electromagnetic emission is observed frequently before earthquakes as high noise level in VLF and ULF bands. We present theoretical considerations on electromagnetic radiation caused by dislocation dynamics in the preseismic micro-sources (micro-crackings located in an earthquake preparation zone. Some of these micro-sources could be located near the ground surface and their electromagnetic signals could be accesible in some recording stations. The examples of the numerically simulated induction and radiation fields are given and one example of the observed radio-noise recording is shown.

  3. [Effects of electromagnetic radiation on RAF/MEK/ERK signaling pathway in rats hippocampus].

    Science.gov (United States)

    Zuo, Hong-yan; Wang, De-wen; Peng, Rui-yun; Wang, Shui-ming; Gao, Ya-bing; Xu, Xin-ping; Ma, Jun-Jie

    2009-05-01

    To study the development of changes for signaling molecules related to Raf/MEK/ERK pathway in hippocampus of rats after electromagnetic radiation, and investigate the mechanisms of radiation injury. Rats were exposed to X-HPM, S-HPM and EMP radiation source respectively, and animal model of electromagnetic radiation was established. Western blot was used to detect the expression of Raf-1, phosphorylated Raf-1 and phospholylated ERK. The expression of Raf-1 down-regulated during 6 h-14 d after radiation, most significantly at 7 d, and recovered at 28 d. There was no significant difference between the radiation groups. The expression of phosphorylated Raf-1 and phosphorylated ERK both up-regulated at 6 h and 7 d after radiation, more significantly at 6 h, and the two microwave groups were more serious for phosphorylated ERK. During 6 h-14 d after S-HPM radiation, the expression of phosphorylated Raf-1 increased continuously, but phosphorylated ERK changed wavily, 6 h and 7 d were expression peak. Raf/MEK/ERK signaling pathway participates in the hippocampus injury induced by electromagnetic radiation. The excessive activation of ERK pathway may result in the apoptosis and death of neurons, which is the important mechanism of recognition disfunction caused by electromagnetic radiation.

  4. Breathers in Josephson junction ladders: Resonances and electromagnetic wave spectroscopy

    DEFF Research Database (Denmark)

    Miroshnichenko, A. E.; Flach, S.; Fistul, M.

    2001-01-01

    We present a theoretical study of the resonant interaction between dynamical localized states (discrete breathers) and linear electromagnetic excitations (EE's) in Josephson junction ladders. By making use of direct numerical simulations we find that such an interaction manifests itself by resonant...

  5. Interlevel absorption of electromagnetic waves by nanocrystal with divalent impurity

    Directory of Open Access Journals (Sweden)

    V. I Boichuk

    2014-06-01

    Full Text Available The energy spectrum of central divalent impurity is calculated using the effective mass approximation in a spherical quantum dot (QD. The dipole moment and oscillator strength of interlevel transition is defined. The dependence of linear absorption coefficient on the QD size and electromagnetic frequency is analyzed. The obtained results are compared with the results of univalent impurity.

  6. Electromagnetic Radiation Influence With Molecular Spectrum Absorption and Nitric Oxide Radiation Frequency on Superoxide Dismutase Bacteria Activity

    Directory of Open Access Journals (Sweden)

    G.M. Shub

    2009-06-01

    Full Text Available The dynamics of superoxide dismutase activity level under the influence of electromagnetic radiation with spectrum absorption and nitric oxide radiation frequency in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa has been described. The panoramic spectrometric measuring complex, developed in Saratov Central Scientific Research Institute of Measuring Equipment Public Corporation has been used while carrying out the research. Electromagnetic vibrations of extremely high frequencies stimulated in this complex imitate the structure of molecular spectrum absorption and nitric oxide radiation. The activity of superoxide dismutase has been detected. The most significant changes have been observed under 45 and 60-minute exposition.

  7. RADIATIVE DAMPING AND EMISSION SIGNATURES OF STRONG SUPERLUMINAL WAVES IN PULSAR WINDS

    Energy Technology Data Exchange (ETDEWEB)

    Mochol, Iwona; Kirk, John G., E-mail: iwona.mochol@mpi-hd.mpg.de, E-mail: john.kirk@mpi-hd.mpg.de [Max-Planck-Institut für Kernphysik, Postfach 10 39 80, D-69029 Heidelberg (Germany)

    2013-10-10

    We analyze the damping of strong, superluminal electromagnetic waves by radiation reaction and Compton drag in the context of pulsar winds. The associated radiation signature is found by estimating the efficiency and the characteristic radiation frequencies. Applying these estimates to the gamma-ray binary containing PSR B1259–63, we show that the GeV flare observed by the Fermi Large Area Telescope can be understood as inverse-Compton emission by particles scattering photons from the companion star, if the pulsar wind termination shock acquires a precursor of superluminal waves roughly 30 days after periastron. This requirement constrains the mass-loading factor of the wind μ=L/ N-dot mc{sup 2}, where L is the luminosity and N-dot is the rate of loss of electrons and positrons, to be roughly 6 × 10{sup 4}.

  8. Microwave metamaterials—from passive to digital and programmable controls of electromagnetic waves

    Science.gov (United States)

    Cui, Tie Jun

    2017-08-01

    Since 2004, my group at Southeast University has been carrying out research into microwave metamaterials, which are classified into three catagories: metamaterials based on the effective medium model, plasmonic metamaterials for spoof surface plasmon polaritons (SPPs), and coding and programmable metamaterials. For effective-medium metamaterials, we have developed a general theory to accurately describe effective permittivity and permeability in semi-analytical forms, from which we have designed and realized a three dimensional (3D) wideband ground-plane invisibility cloak, a free-space electrostatic invisibility cloak, an electromagnetic black hole, optical/radar illusions, and radially anisotropic zero-index metamaterial for omni-directional radiation and a nearly perfect power combination of source array, etc. We have also considered the engineering applications of microwave metamaterials, such as a broadband and low-loss 3D transformation-optics lens for wide-angle scanning, a 3D planar gradient-index lens for high-gain radiations, and a random metasurface for reducing radar cross sections. In the area of plasmonic metamaterials, we proposed an ultrathin, narrow, and flexible corrugated metallic strip to guide SPPs with a small bending loss and radiation loss, from which we designed and realized a series of SPP passive devices (e.g. power divider, coupler, filter, and resonator) and active devices (e.g. amplifier and duplexer). We also showed a significant feature of the ultrathin SPP waveguide in overcoming the challenge of signal integrity in traditional integrated circuits, which will help build a high-performance SPP wireless communication system. In the area of coding and programmable metamaterials, we proposed a new measure to describe a metamaterial from the viewpoint of information theory. We have illustrated theoretically and experimentally that coding metamaterials composed of digital units can be controlled by coding sequences, leading to different

  9. On the new modes of planetary-scale electromagnetic waves in the ionosphere

    Directory of Open Access Journals (Sweden)

    G. D. Aburjania

    2004-04-01

    Full Text Available Using an analogy method the frequencies of new modes of the electromagnetic planetary-scale waves (with a wavelength of 103 km or more, having a weather forming nature, are found at different ionospheric altitudes. This method gives the possibility to determine spectra of ionospheric electromagnetic perturbations directly from the dynamic equations without solving the general dispersion equation. It is shown that the permanently acting factor-latitude variation of the geomagnetic field generates fast and slow weakly damping planetary electromagnetic waves in both the E- and F-layers of the ionosphere. The waves propagate eastward and westward along the parallels. The fast waves have phase velocities (1–5km s–1 and frequencies (10–1–10–4, and the slow waves propagate with velocities of the local winds with frequencies (10–4–10–6s–1 and are generated in the E-region of the ionosphere. Fast waves having phase velocities (10-1500km s–1 and frequencies (1–10–3s–1 are generated in the F-region of the ionosphere. The waves generate the geomagnetic pulsations of the order of one hundred nanoTesla by magnitude. The properties and parameters of the theoretically studied electromagnetic waves agree with those of large-scale ultra-low frequency perturbations observed experimentally in the ionosphere.

    Key words. Ionosphere (ionospheric disturbances; waves propagation; ionosphere atmosphere interactions

  10. Wave energy budget analysis in the Earth's radiation belts uncovers a missing energy

    Science.gov (United States)

    Artemyev, A.V.; Agapitov, O.V.; Mourenas, D.; Krasnoselskikh, V.V.; Mozer, F.S.

    2015-01-01

    Whistler-mode emissions are important electromagnetic waves pervasive in the Earth's magnetosphere, where they continuously remove or energize electrons trapped by the geomagnetic field, controlling radiation hazards to satellites and astronauts and the upper-atmosphere ionization or chemical composition. Here, we report an analysis of 10-year Cluster data, statistically evaluating the full wave energy budget in the Earth's magnetosphere, revealing that a significant fraction of the energy corresponds to hitherto generally neglected very oblique waves. Such waves, with 10 times smaller magnetic power than parallel waves, typically have similar total energy. Moreover, they carry up to 80% of the wave energy involved in wave–particle resonant interactions. It implies that electron heating and precipitation into the atmosphere may have been significantly under/over-valued in past studies considering only conventional quasi-parallel waves. Very oblique waves may turn out to be a crucial agent of energy redistribution in the Earth's radiation belts, controlled by solar activity. PMID:25975615

  11. Bending, splitting, compressing and expanding of electromagnetic waves in infinitely anisotropic media

    Science.gov (United States)

    Zhang, Youming; Zhang, Baile

    2018-01-01

    High-efficiency diffraction-free manipulations of electromagnetic (EM) waves are fundamentally difficult to realize, though reflectionless wave bending or sub-diffraction-limited imaging has been realized separately in previous demonstrations. Recent advances in epsilon-near-zero and anisotropic epsilon-near-infinity metamaterials have provided unique possibilities to achieve reflectionless diffraction-free EM wave manipulations. Here, we propose bending, splitting, compressing and expanding of EM waves with infinitely anisotropic media that can be achieved without diffraction or reflection. The results are verified by numerical simulations. This work furthers the study of infinitely anisotropic media, and might find applications in high-efficiency interconnection of subwavelength photonic information.

  12. Solving the characteristic initial-value problem for colliding plane gravitational and electromagnetic waves.

    Science.gov (United States)

    Alekseev, G A; Griffiths, J B

    2001-11-26

    A method is presented for solving the characteristic initial-value problem for the collision and subsequent nonlinear interaction of plane gravitational or gravitational and electromagnetic waves in a Minkowski background. This method generalizes the monodromy-transform approach to fields with nonanalytic behavior on the characteristics inherent to waves with distinct wave fronts. The crux of the method is in a reformulation of the main nonlinear symmetry reduced field equations as linear integral equations whose solutions are determined by generalized ("dynamical") monodromy data which evolve from data specified on the initial characteristics (the wave fronts).

  13. Excitation of plasma waves by nonlinear currents induced by a high-frequency electromagnetic pulse

    Energy Technology Data Exchange (ETDEWEB)

    Grishkov, V. E.; Uryupin, S. A., E-mail: uryupin@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

    2017-03-15

    Excitation of plasma waves by nonlinear currents induced by a high-frequency electromagnetic pulse is analyzed within the kinetic approach. It is shown that the most efficient source of plasma waves is the nonlinear current arising due to the gradient of the energy density of the high-frequency field. Generation of plasma waves by the drag current is usually less efficient but not negligibly small at relatively high frequencies of electron–ion collisions. The influence of electron collisions on the excitation of plasma waves by pulses of different duration is described quantitatively.

  14. Rotatable illusion media for manipulating terahertz electromagnetic waves

    National Research Council Canada - National Science Library

    Zang, XiaoFei; Li, Zhou; Shi, Cheng; Chen, Lin; Cai, Bin; Zhu, YiMing; Li, Li; Wang, XiaoBin

    2013-01-01

    Based on composite optical transformation, we propose a rotatable illusion media with positive permittivity and permeability to manipulate terahertz waves, and a new way to realize singular parameter...

  15. The interaction of a circularly orbiting electromagnetic harmonic wave with an electron having a constant time independent drift velocity

    NARCIS (Netherlands)

    Rashid, M.

    2011-01-01

    A circularly orbiting electromagnetic harmonic wave may appear when a 1S electron encounters a decelerating stopping positively charged hole inside a semiconductor. The circularly orbiting electromagnetic harmonic wave can have an interaction with a conducting electron which has a constant time

  16. 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...

  17. An Enhancing Effect of Gold Nanoparticles on the Lethal Action of 2450 MHz Electromagnetic Radiation in Microwave Oven.

    Science.gov (United States)

    Mollazadeh-Moghaddam, Kamyar; Moradi, Bardia Varasteh; Dolatabadi-Bazaz, Reza; Shakibae, Mojtaba; Shahverdi, Ahmad Reza

    2011-10-01

    Today, there is an increasing interest in the use of metal nanoparticles in health sciences. Amongst all nanoparticles, the gold nanoparticles have been known to kill the cancer cells under hyperthermic condition by near-infrared frequency electromagnetic waves. On the other hand, although there are different physiochemical methods for disinfection of microbial pollution, however applications of irradiated gold nanoparticles against microorganisms have not yet been investigated. In this study, gold nanoparticles were prepared using D-glucose and characterized (particle size electromagnetic radiation generated at a microwave oven operated at low power (100 W), was investigated by time-kill course assay against Staphylococcus aureus (S.aureus) ATCC 29737. The results showed that application of gold nanoparticles can enhance the lethal effect of low power microwave in a very short exposure time (5 s).

  18. Competition between atomic coherence and electromagnetically induced population grating in multi-wave mixing

    Science.gov (United States)

    Lou, Lin; Sun, Jia; Feng, Weikang; Wu, Zhenkun; Zhang, Yiqi; Zhang, Yanpeng

    2014-12-01

    We study the competition and transfer between atomic coherence and electromagnetically induced population grating of multi-wave mixing (MWM) in four- and five-level atomic systems. The MWM signal falls into a new type electromagnetically induced transparency (EIT) window that depends on propagating directions of the related fields rather than atomic system configuration. By blocking different coupling laser beams, we experimentally distinguish different wave mixing processes. In addition, by changing the detuning of pump beams, we can observe double peaks for both EIT and MWM signals. The results may have potential applications in correlated photon-pair generations in four-wave mixing as well as six-wave mixing and quantum information processing.

  19. 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.

  20. Optical theorem for electromagnetic field scattering by dielectric structures and energy emission from the evanescent wave.

    Science.gov (United States)

    Gulyaev, Yu V; Barabanenkov, Yu N; Barabanenkov, M Yu; Nikitov, S A

    2005-08-01

    We present an optical theorem for evanescent (near field) electromagnetic wave scattering by a dielectric structure. The derivation is based on the formalism of angular spectrum wave amplitudes and block scattering matrix. The optical theorem shows that an energy flux is emitted in the direction of the evanescent wave decay upon scattering. The energy emission effect from an evanescent wave is illustrated in two examples of evanescent wave scattering, first, by the electrical dipole and, second, one-dimensional grating with line-like rulings. Within the latter example, we show that an emitted energy flux upon evanescent wave scattering can travel through a dielectric structure even if the structure has a forbidden gap in the transmission spectrum of incident propagating waves.