Electromagnetic drift modes in an inhomogeneous electron gas
Shukla, P. K.; Pecseli, H. L.; Juul Rasmussen, Jens
1986-01-01
A pair of nonlinear equations is derived which describes the dynamics of the electromagnetic drift oscillations in a nonuniform magnetized electron gas. It is shown that the nonlinear electromagnetic drift modes can propagate in the form of dipole vortices......A pair of nonlinear equations is derived which describes the dynamics of the electromagnetic drift oscillations in a nonuniform magnetized electron gas. It is shown that the nonlinear electromagnetic drift modes can propagate in the form of dipole vortices...
Electromagnetic fields and transport coefficients in a hot pion gas
Gomez Nicola, A. [Departamentos de Fisica Teorica I, II, Universidad Complutense, 28040 Madrid (Spain); Fernandez-Fraile, D. [Departamentos de Fisica Teorica I, II, Universidad Complutense, 28040 Madrid (Spain)
2007-03-15
We present recent results on finite temperature electromagnetic form factors and the electrical conductivity in a pion gas. The standard Chiral Perturbation Theory power counting needs to be modified for transport coefficients. We pay special attention to unitarity and to possible applications for dilepton and photon production.
Electromagnetically driven, fast opening and closing gas jet valve
Krishnan, Mahadevan; Elliott, Kristi Wilson; Geddes, C. G. R.; van Mourik, R. A.; Leemans, W. P.; Murphy, H.; Clover, M.
2011-03-01
The design and performance are presented of an electromagnetically driven gas valve [M. Krishnan, J. Wright, and T. Ma, Proceedings of the 13th Advanced Accelerator Concepts Workshop, Santa Cruz, CA, AIP Conf. Proc. No. 1086 (AIP, New York, 2008)] that opens in <100μs, closes in <500μs, and can operate at pressures of ˜1000psia to drive supersonic nozzles. Such a valve has applications to laser-plasma accelerators, where the fast opening and closing would allow sharper edges to the flow and also allow higher rep-rate operation without loading the vacuum chamber. The valve action is effected by a flyer plate accelerated by the electromagnetic impulse of a low inductance, spiral wound, strip-line coil driven by a capacitor. Gas flows out of the valve when the seal between this flyer plate and the valve seat is broken. The electromagnetic force greatly exceeds the restoring forces provided by a spring and the gas pressure against the valve seat. Piezoresistive sensor and laser interferometer measurements of flow show that the valve opens in ˜100μs for all pressures up to 800 psia. The closing time is 500μs, set by the spring constant and mass. The prototype valve has been operated with helium at 0.5 Hz and at 500 psia for ˜1 hour at a time with no cooling.
Influence of electromagnetism field on the flame transmission and shock wave in gas explosion
Li Jing [Anhui University of Technology, Maanshan (China). College of Metallurgy and Resources
2008-01-15
The influence of electromagnetic field on flame transmission and explosion wave overpressure in gas explosions was investigated. The research results show that the velocity of flame propagation and the explosion wave overpressure in an electromagnetic field is much higher than that in plain tube, and the stronger the electromagnetic field, the greater the influence. Based on experimental results, the influence of electromagnetic field on gas explosion propagation was analyzed and a reasonable explanation was put forward. The influence of electromagnetic field is not equal to the sum of the electric field and the magnetic field. 7 refs., 4 figs., 2 tabs.
Effect of electromagnetic force and anode gas on electrolyte flow in aluminum electrolysis cell
ZHOU Nai-jun; XIA Xiao-xia; BAO Sheng-zhong
2006-01-01
Based on the commercial computational fluid dynamics software CFX-4.3, electrolyte flow fields in a 156 kA pre-baked anode aluminum electrolysis cell were investigated in three different cases where the electrolyte melt was driven by different kinds of force, i.e. electromagnetic force only, the anode gas drag force only and both of the former two forces. The results show that when electromagnetic force was introduced only, most of the electrolyte moves horizontally; when anode gas drag force was introduced only, the electrolyte flows mainly around each anode with small circulation; when electromagnetic force and anode gas drag force were both introduced together, the structure of the electrolyte flow fields and the velocity of electrolyte are similar to that of the case where only anode gas drag force is used. The electrolyte flow fields are mainly determined by the anode gas drag force.
Without the electromagnetic force, you would not be solid. The atoms of your body are held together by electromagnetism: negatively charged electrons are held around the positively charged nucleus. Atoms share electrons to form molecules, so building up the structure of matter. As its name suggests, electromagnetism has a double nature: a moving electric charge creates a magnetic field. This intimate connection between electricity and magnetism was described by James Maxwell in 1864. The electromagnetic force can be both positive and negative : opposite charges attract, whereas like charges repel. Electromagnetic radiation, such as radio, microwaves, light and X-rays, is emitted by charges when they are made to move. For example, an oscillating current in a wire emits radio waves. Text for the interactive: Why do the needles move when you switch on the current ?
胡正峰; 杜春光; 李代军; 李师群
2002-01-01
We investigate electromagnetically induced transparency and slow group velocity of light in ultracold Bose gas with a two-photon Raman process. The properties of electromagnetically induced transparency and light speed can be changed by controlling the atomic interaction. Atomic interaction can be used as a knob to control the optical properties of atomic media. This can be realized in experiment by using the Feshbach resonance technique.
Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode
Poehlmann, Flavio R.; Cappelli, Mark A.; Rieker, Gregory B.
2010-01-01
Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma def...
Electromagnetically-induced-transparency intensity-correlation power broadening in a buffer gas
Zheng, Aojie; Green, Alaina; Crescimanno, Michael; O'Leary, Shannon
2016-04-01
Electromagnetically-induced-transparency (EIT) noise correlation spectroscopy holds promise as a simple, robust method for performing high-resolution spectroscopy used in optical magnetometry and clocks. Of relevance to these applications, we report on the role of buffer gas pressure and magnetic field gradients on power broadening of Zeeman-EIT noise correlation resonances.
Grant, Ian S
1990-01-01
The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw the Physics of Stars Second Edition A. C. Phillips Computing for Scient
Han, Jingshan; Li, Wenhui
2016-01-01
We perform spectroscopic measurements of electromagnetically induced transparency (EIT) in a strongly interacting Rydberg gas, and observe a significant spectral shift of the transparency from the single-atom EIT resonance as well as a spectral dephasing of the same order. We characterize the shift and dephasing as a function of atomic density, probe Rabi frequency, and principal quantum number of Rydberg states, and demonstrate that the observed spectral shift and dephasing are reduced if the size of a Gaussian atomic cloud is increased. We simulate our experiment with a semi-analytical model, which gives results in good agreement with our experimental data.
Proskuryakov, V.M.; Shabarov, A.N.; Frid, V.I. (Vsesoyuznyi Nauchno-Issledovatel' skii Institut Gornoi Geomekhaniki i Marksheiderskogo Dela (USSR))
1991-02-01
Presents results of investigations into emission of electromagnetic waves in zones of increased rock burst hazard conducted during drivage of a ventilation gallery in the Anzherskaya mine (Severokuzbassugol' association). Relationships between the emission of electromagnetic impulses, yield of drilling, gas yield rate, the distance between increased stress zones and seam denudation and time are discussed and presented in diagrams. Regularities of variation in electromagnetic radiation at various stress states in coal seam boundary parts with the gas yield factor taken into account were found. Suitability of recording electromagnetic radiation for forecasting rock burst hazards was shown and criteria for evaluating the degree of rock burst hazard for a coal seam in the Anzherskaya mine are presented. 3 refs.
Qin, Qiming; Zhang, Zili; Chen, Li; Wang, Nan; Zhang, Chengye
2016-01-01
This paper proposes a method that combined hyperspectral remote sensing with super-low-frequency (SLF) electromagnetic detection to extract oil and gas reservoir characteristics from surface to underground, for the purpose of determining oil and gas exploration target regions. The study area in Xinjiang Karamay oil-gas field, China, was investigated. First, a Hyperion dataset was used to extract altered minerals (montmorillonite, chlorite, and siderite), which were comparatively verified by field survey and spectral measurement. Second, the SLF electromagnetic datasets were then acquired where the altered minerals were distributed. An inverse distance weighting method was utilized to acquire two-dimensional profiles of the electrical feature distribution of different formations on the subsurface. Finally, existing geological data, field work, and the results derived from Hyperion images and SLF electromagnetic datasets were comprehensively analyzed to confirm the oil and gas exploration target region. The results of both hyperspectral remote sensing and SLF electromagnetic detection had a good consistency with the geological materials in this study. This paper demonstrates that the combination of hyperspectral remote sensing and SLF electromagnetic detection is suitable for the early exploration of oil and gas reservoirs, which is characterized by low exploration costs, large exploration areas, and a high working efficiency.
Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode.
Poehlmann, Flavio R; Cappelli, Mark A; Rieker, Gregory B
2010-12-01
Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma deflagration. The effects of varying the bank capacitance, transmission line inductance, and applied electrode voltage were studied over the range from 14 to 112 μF, 50 to 200 nH, and 1 to 3 kV, respectively.
Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode
Poehlmann, Flavio R.; Cappelli, Mark A.; Rieker, Gregory B.
2010-12-01
Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma deflagration. The effects of varying the bank capacitance, transmission line inductance, and applied electrode voltage were studied over the range from 14 to 112 μF, 50 to 200 nH, and 1 to 3 kV, respectively.
Electromagnetically induced transparency-based gas detector design using Michelson interferometer
Abbasian, Karim; Abdollahi, Mohammad Hossein
2013-05-01
In this paper, we have designed an all-optical controllable gas detector by doping 3-level Λ type nanocrystals in the moving arms' mirror of Michelson interferometer and used electromagnetically induced transparency (EIT) phenomenon to change its refractive index. By this means, we have created a controllable phase difference between light beams in two arms of the Michelson interferometer, where reflection phase of the EIT-based mirror changes about π radiant. Also, the signal reflection from EIT-based mirror changes between 0% and 100% approximately, while the second arm's signal is reflected completely. This EIT-based mirror's refractive index change can be a good alternative for conventional Michelson interferometer-based gas detector with one mechanical moving arm mirror (Undergraduate Instrumental Analysis, 6th edn. Marcel Dekker, New York, 2005), where long response time and unfix moving speed were its main drawbacks. While, in this scheme, not only these disadvantages are removed but also the response time can reach the electron transient time between the atomic energy levels. Then, by this all-optical tunable gas detector, we have achieved many modifications such as response time in sub-nanoseconds, high resolution, and high accuracy, or less cross sensitivity to other gas species.
The deep-tow marine controlled-source electromagnetic transmitter system for gas hydrate exploration
Wang, Meng; Deng, Ming; Wu, Zhongliang; Luo, Xianhu; Jing, Jianen; Chen, Kai
2017-02-01
The Marine Controlled-Source Electromagnetic (MCSEM) method has been recognized as an important and effective tool to detect electrically resistive structures, such as oil, gas, and gas hydrate. The MCSEM performance is strongly influenced by the transmitter system design. We have developed a deep-tow MCSEM transmitter system. In this paper, some new technical details will be present. A 10,000 m optical-electrical composite cable is used to support high power transmission and fast data transfer; a new clock unit is designed to keep the synchronization between transmitter and receivers, and mark the time stamp into the transmission current full waveform; a data link is established to monitor the real-time altitude of the tail unit; an online insulation measuring instrument is adopted to monitor current leakage from high voltage transformer; a neutrally buoyant dipole antenna of copper cable and flexible electrodes are created to transmit the large power current into seawater; a new design method for the transmitter, which is called "real-time control technology of hardware parallelism", is described to achieve inverting and recording high-power current waveform, controlling functions, and collecting auxiliary information. We use a gas hydrate exploration test to verify the performance of the transmitter system, focusing on more technical details, rather than applications. The test shows that the transmitter can be used for gas hydrate exploration as an effective source.
V-type electromagnetically induced transparency and saturation effect at the gas-solid interface
Meng, Tengfei; Ji, Zhonghua; Su, Dianqiang; Xiao, Liantuan; Jia, Suotang
2015-01-01
We theoretically study electromagnetically induced transparency (EIT) in reflection spectra of V-type system at the gas-solid interface. In addition to a narrow dip arising from the EIT effect, we find the other particular saturation effect induced by pump field, which does not exist in $\\Lambda$ or $\\Xi$ -type system reflection spectra. The saturation effect only induces an intensity decrement in the reflection spectra, and there is no influence on the narrow dip arising from the EIT effect. We detailedly calculate and analyze the dependence of V-type system reflection spectra on probe field intensity, pump field intensity, coherent decay rate, and the initial population after the collision between atoms and the interface.
Han, Jingshan; Vogt, Thibault; Li, Wenhui
2016-10-01
We perform spectroscopic measurements of electromagnetically induced transparency (EIT) in a strongly interacting Rydberg gas. We observe a significant spectral shift and attenuation of the transparency resonance due to the presence of interactions between Rydberg atoms. We characterize the attenuation as the result of an effective dephasing and show that the shift and the dephasing rate increase versus atomic density, probe Rabi frequency, and principal quantum number of Rydberg states. Moreover, we find that the spectral shift is reduced if the size of a Gaussian atomic cloud is increased and that the dephasing rate increases with the EIT pulse duration at large-parameter regimes. We simulate our experiment with a semianalytical model, which yields results in good agreement with our experimental data.
Zamanian, Z; Gharepoor, S; Dehghani, M
2010-10-01
The aims of this study are to assess, in a power station in Shiraz, the effects of noise and electromagnetic field on psychological mood. By the great industrial and technological improvements human beings have been exposed to different types of physical and chemical factors. Some of these factors such as electromagnetism are known as the constant components of the environment. According to the studies carried out in one of the power stations in Shiraz, psychological disorders caused by jobs are among the most important problems of the workers. This study is performed to determine the presence or absence of these psychological disorders. This cross-sectional study is performed on these groups : (1) The gas power plant staff who were in contact with electromagnetic field and nose, (2) employees who were only exposed to noise and (3) a group of staff employed in the administrative parts of the Telecommunication companies who did not have any history of being exposed to electromagnetic field and sounds. The General Health Questionnaire (GHQ) is used in this study to recognize psychosomatic disorders. Measurements indicate that range of electromagnetic field varies from 0.087 micro Tesla in the phone homes to 30 micro Tesla in power stations. The results of this study has shown that a significant number of staff which were exposed to electromagnetic fields and noise (78.2%) were suspected to have a kind of mental disorders. The results obtained from this study which shows the prevalence of mental disorders among the suspected case is higher than the results of Noorbala and colleagues study in 2006.
Schwalenberg, Katrin; Rippe, Dennis; Koch, Stephanie; Scholl, Carsten
2017-05-01
Marine controlled source electromagnetic (CSEM) data have been collected to investigate methane seep sites and associated gas hydrate deposits at Opouawe Bank on the southern tip of the Hikurangi Margin, New Zealand. The bank is located in about 1000 m water depth within the gas hydrate stability field. The seep sites are characterized by active venting and typical methane seep fauna accompanied with patchy carbonate outcrops at the seafloor. Below the seeps, gas migration pathways reach from below the bottom-simulating reflector (at around 380 m sediment depth) toward the seafloor, indicating free gas transport into the shallow hydrate stability field. The CSEM data have been acquired with a seafloor-towed, electric multi-dipole system measuring the inline component of the electric field. CSEM data from three profiles have been analyzed by using 1-D and 2-D inversion techniques. High-resolution 2-D and 3-D multichannel seismic data have been collected in the same area. The electrical resistivity models show several zones of highly anomalous resistivities (>50 Ωm) which correlate with high amplitude reflections located on top of narrow vertical gas conduits, indicating the coexistence of free gas and gas hydrates within the hydrate stability zone. Away from the seeps the CSEM models show normal background resistivities between 1 and 2 Ωm. Archie's law has been applied to estimate gas/gas hydrate saturations below the seeps. At intermediate depths between 50 and 200 m below seafloor, saturations are between 40 and 80% and gas hydrate may be the dominating pore filling constituent. At shallow depths from 10 m to the seafloor, free gas dominates as seismic data and gas plumes suggest.
Honig, J.; Kim, K.; Wedge, S.W.
1986-05-01
Hydrogen pellets are successfully accelerated for the first time using a two-stage system consisting of a pneumatic gun and an electromagnetic railgun. The pneumatic gun preaccelerator forms cylindrical hydrogen ice pellets (1.6-mm diam x 2.15-mm long) and accelerates them with high-pressure helium gas to velocities in excess of 500 m/s. The booster accelerator, which is a fuseless, circular-bore electromagnetic railgun, derives its propulsive force from a plasma arc armature. The plasma arc armature is formed by electrically breaking down the propellant gas which follows the pellet from the gas gun into the railgun. The diagnostics are for the monitoring of the main capacitor bank and rail currents, for the pellet detection and velocity measurements at the breech and muzzle ends of the railgun, for the recording of the plasma-arc-armature movement inside the railgun bore, and for the photographing of the hydrogen pellet exiting the railgun. Using the system, which is a 60-cm long proof-of-principle machine for refueling magnetic fusion devices, hyrogen pellet velocities exceeding 1 km/s have been achieved for pellets exiting the gas gun at velocities of approx.500 m/s.
Kim, B.; Byun, J.; Seol, S. J.; Jeong, S.; Chung, Y.; Kwon, T.
2015-12-01
For many decades, gas hydrates have been received great attention as a potential source of natural gas. Therefore, the detailed information of structures of buried gas hydrates and their concentrations are prerequisite for the production for the gas hydrate as a reliable source of alternate energy. Recently, for this reason, a lot of gas hydrate assessment methods have been proposed by many researchers. However, it is still necessary to establish as new method for the further improvement of the accuracy of the 3D gas hydrate distribution. In this study, we present a 3D joint inversion method that provides superior quantitative information of gas hydrate distributions using 3D seismic data obtained by ocean-bottom cable (OBC) and marine controlled-source electromagnetic (CSEM) data. To verify our inversion method, we first built the general 3D gas hydrate model containing vertical methane-flow pathways. With the described model, we generated synthetic 3D OBC data and marine CSEM data using finite element modeling algorithms, respectively. In the joint inversion process, to obtain the high-resolution volumetric P-wave velocity structure, we applied the 3D full waveform inversion algorithm to the acquired OBC data. After that, the obtained P-wave velocity model is used as the structure constraint to compute cross-gradients with the updated resistivity model in the EM inversion process. Finally, petrophysical relations were applied to estimate volumetric gas hydrate concentrations. The proposed joint inversion process makes possible to obtain more precise quantitative gas hydrate assessment than inversion processes using only seismic or EM data. This technique can be helpful for accurate decision-making in gas hydrate development as well as in their production monitoring.
Attias, Eric; Weitemeyer, Karen; Minshull, Tim A.; Best, Angus I.; Sinha, Martin; Jegen-Kulcsar, Marion; Hölz, Sebastian; Berndt, Christian
2016-08-01
Deep sea pockmarks underlain by chimney-like or pipe structures that contain methane hydrate are abundant along the Norwegian continental margin. In such hydrate provinces the interaction between hydrate formation and fluid flow has significance for benthic ecosystems and possibly climate change. The Nyegga region, situated on the western Norwegian continental slope, is characterized by an extensive pockmark field known to accommodate substantial methane gas hydrate deposits. The aim of this study is to detect and delineate both the gas hydrate and free gas reservoirs at one of Nyegga's pockmarks. In 2012, a marine controlled-source electromagnetic (CSEM) survey was performed at a pockmark in this region, where high-resolution 3-D seismic data were previously collected in 2006. 2-D CSEM inversions were computed using the data acquired by ocean bottom electrical field receivers. Our results, derived from unconstrained and seismically constrained CSEM inversions, suggest the presence of two distinctive resistivity anomalies beneath the pockmark: a shallow vertical anomaly at the underlying pipe structure, likely due to gas hydrate accumulation, and a laterally extensive anomaly attributed to a free gas zone below the base of the gas hydrate stability zone. This work contributes to a robust characterization of gas hydrate deposits within subseafloor fluid flow pipe structures.
Evolution of a dense neutrino gas in matter and electromagnetic field
Dvornikov, Maxim
2011-01-01
We describe the system of massive Weyl fields propagating in background matter and interacting with an external electromagnetic field. The interaction with an electromagnetic field is due to the presence of anomalous magnetic moments. To canonically quantize this system first we develop the classical field theory treatment of Weyl spinors in frames of the Hamilton formalism which accounts for the external fields. Then, on the basis of the exact solution of the wave equation for a massive Weyl field in background matter we obtain the effective Hamiltonian for the description of spin-flavor oscillations of Majorana neutrinos in matter and a magnetic field. Finally, we incorporate in our analysis the neutrino self-interaction which is essential when the neutrino density is sufficiently high. We also discuss the applicability of our results for the studies of collective effects in spin-flavor oscillations of supernova neutrinos in dense matter and strong magnetic field.
García-Rentería, M.A., E-mail: crazyfim@gmail.com [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); López-Morelos, V.H., E-mail: vhlopez@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); García-Hernández, R., E-mail: rgarcia@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); Dzib-Pérez, L., E-mail: luirdzib@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); García-Ochoa, E.M., E-mail: emgarcia@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); González-Sánchez, J., E-mail: jagonzal@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico)
2014-12-01
Highlights: • Electromagnetic interaction in welding improved localised corrosion resistance. • Electromagnetic interaction in welding enhanced γ/δ phase balance of DuplexSS. • Welding under Electromagnetic interaction repress formation and growth of detrimental phases. • Welds made with gas protection (2% O{sub 2} + 98% Ar) have better microstructural evolution during welding. - Abstract: The resistance to localised corrosion of AISI 2205 duplex stainless steel plates joined by Gas Metal Arc Welding (GMAW) under the effect of electromagnetic interaction of low intensity (EMILI) was evaluated with sensitive electrochemical methods. Welds were made using two shielding gas mixtures: 98% Ar + 2% O{sub 2} (M1) and 97% Ar + 3% N{sub 2} (M2). Plates were welded under EMILI using the M1 gas with constant welding parameters. The modified microstructural evolution in the high temperature heat affected zone and at the fusion zone induced by application of EMILI during welding is associated with the increase of resistance to localised corrosion of the welded joints. Joints made by GMAW using the shielding gas M2 without the application of magnetic field presented high resistance to general corrosion but high susceptibility to undergo localised attack.
Villnow, Michael; Bosselmann, Thomas; Willsch, Michael; Kaiser, Joachim
2014-05-01
A common way to explore oil out of tar sand is to use a technique called Steam Assisted Gravity Drainage SAGD. This method can be enhanced by using an inductive heater (EM-SAGD). To monitor the heat dissipation of the inductor a measurement system for this harsh electromagnetic environment is needed. In this paper different optical temperature measurement systems are compared to find the most suitable system for this kind of application. A field test with great results was performed, where the performance of the inductor and the FBG measurement system were demonstrated.
Liu, Junyang; Hang, Chao; Huang, Guoxiang
2016-06-01
We propose a scheme to demonstrate the existence of optical Peregrine rogue waves and Akhmediev and Kuznetsov-Ma breathers and realize their active control via electromagnetically induced transparency (EIT). The system we suggest is a cold, Λ -type three-level atomic gas interacting with a probe and a control laser fields and working under EIT condition. We show that, based on EIT with an incoherent optical pumping, which can be used to cancel optical absorption, (1+1)-dimensional optical Peregrine rogue waves, Akhmediev breathers, and Kuznetsov-Ma breathers can be generated with very low light power. In addition, we demonstrate that the Akhmediev and Kuznetsov-Ma breathers in (2+1)-dimensions obtained can be actively manipulated by using an external magnetic field. As a result, these breathers can display trajectory deflections and bypass obstacles during propagation.
Shimokawa, Y; Matsuura, Y; Hirano, T; Sakai, K
2016-12-01
Utilizing a graphite-disk probe attached with a thin aluminum disk, we have developed a friction-free viscosity measurement system. The probe is levitated above a NdFeB magnet because of diamagnetic effect and rotated by an electromagnetically induced torque. The probe is absolutely free form mechanical friction, and therefore, the accurate measurements of the viscosity of gases can be achieved. To demonstrate the accuracy and sensitivity of our method, we measured the viscosity of 8 kinds of gases and its temperature change from 278 K to 318 K, and we confirmed a good agreement between the obtained values and literature values. This paper demonstrates that our method has the ability to measure the fluid viscosity in the order of μPa ⋅ s.
Tanaka, Takamitsu
2011-12-01
Supermassive black holes permeate the observable Universe, residing in the nuclei of all or nearly all nearby massive galaxies and powering luminous quasars as far as ten billion light years away. These monstrous objects must grow through a combination of gas accretion and mergers of less massive black holes. The direct detection of the mergers by future gravitational-wave detectors will be a momentous scientific achievement, providing tests of general relativity and revealing the cosmic evolution of supermassive black holes. An additional --- and arguably equally rewarding --- challenge is the concomitant observation of merging supermassive black holes with both gravitational and electromagneticwaves. Such synergistic, "multi-messenger" studies can probe the expansion history of the Universe and shed light on the details of accretion astrophysics. This thesis examines the mergers of supermassive black hole binaries and the observable signatures of these events. First, we consider the formation scenarios for the earliest supermassive black holes. This investigation is motivated by the Sloan Digital Sky Survey observation of a quasar that appears to be powered by a supermassive black hole with a mass of billions of solar masses, already in place one billion years after the Big Bang. Second, we develop semianalytic, time-dependent-models for the thermal emission from circumbinary gas disks around merging black holes. Our calculations corroborate the qualitative conclusion of a previous study that for black hole mergers detectable by a space-based gravitational-wave observatory, a gas disk near the merger remnant may exhibit a dramatic brightening of soft X-rays on timescales of several years. Our results suggest that this "afterglow" may become detectable more quickly after the merger than previously estimated. Third, we investigate whether these afterglow episodes could be observed serendipitously by forthcoming wide-field, high-cadence electromagnetic surveys
Surface electromagnetic technology for the external inspection of oil and gas pipelines
Mousatov, A.; Nakamura, E.; Delgado, O.; Flores, A. [Mexican Petroleum Institute, Mexico City (Mexico); Nakamura, E. [Moscow State University, Moscow (Russian Federation); Shevnin, V. [Moscow State University (Russian Federation)
2009-07-01
In this paper we present a surface electromagnetic technology for the non-destructive pipeline coating inspection (SEMPI). This technology allows: determination of the depth and plane position of pipelines, quantitative evaluation of the insulation resistance and delimitation of zones with coating damages, estimation of the performance of the cathodic protection system (CPS) and detection of its connections to out-of-service pipes and other grounded constructions, and assessment of the soil aggressively. The SEMPI technology is based on the approximation of pipelines by heterogeneous transmission lines with variable leakage conductance and pipe impedance to represent insulation coating and wall thickness damages. Based on the result of simulations, we have optimized the field measurements and developed the interpretation procedure of experimental data. The field operations include surface measurements of magnetic field, voltage on the control posts of the CPS and soil resistivity. In zones with coating damages the detailed measurements can be performed using magnetic or electric field to increase the resolution in localizing and evaluating the insulation damages. The SEMPI technology has been applied for inspections of pipelines with different technical characteristics in complicated environmental conditions. The examples presented in this work confirm the high efficiency of the developed technology for external integrity evaluation of pipelines. (author)
WANG Ru-Zhi; YAN Xiao-Hong
2000-01-01
By developing a transfer-matrix method, the resonant peaks splitting of ballistic conductance are investigated into the two-dimensional electron gas system with both electric and magnetic modulations of nanoscale periods. It is found that there exists the n-fold resonant peak splitting for ballistic conductance through n perpendicular magnetic barriers to n electric barriers. With a combination of m magnetic barriers and n electric barriers by increasing the amplitude of electric field, the folds of the splitting would shift from m － 1 to n － 1.
Finn, K. L.; James, H. R.; Whitworth, N. J.; Handley, C. A.
2009-12-01
In recent years a comprehensive suite of gas-gun particle velocity gauge experiments have been conducted at Los Alamos National Laboratory. Detailed analysis of this data has led to advances in the understanding of the shock to detonation transition in polymer bonded explosives hydrocode simulations of the experiments are frequently used to calibrate reactive-burn models. In these simulations the gauges are modelled using Lagrangian markers with no physical representation of the gauge package. In contrast the experimental gauge package consists of etched aluminium sandwiched between two sheets of FEP Teflon using an urethane-based glue. The gauge package is approximately 60 μm thick is positioned between two wedge-shaped pieces of explosive at an angle of 30 degrees to form a right circular cylinder. This paper investigates with one-dimensional calculations whether there is a need to include an accurate representation of the gauge package within future hydrocode simulations.
Finn, Katherine; Whitworth, Nick; Handley, Caroline
2009-06-01
In recent years, a comprehensive suite of gas-gun particle velocity gauge experiments have been conducted by Gustavsen et al. A detailed analysis of this data has led to advances in the understanding of the shock to detonation transition in polymer bonded explosives, and hydrocode simulations of the experiments are often used to calibrate reactive-burn models. In these simulations, the gauges are often modeled using Lagrangian marker particles, with no physical representation. In contrast, the experimental gauge package, as developed by Vorthman et al. in the early 1980s, consists of etched aluminium sandwiched between two sheets of FEP Teflon, using an urethane-based glue. The resulting gauge package is approximately 60 micrometres thick and is positioned between two wedge-shaped pieces of explosive at an angle of 30 degrees, to form a right-circular cylinder. This paper investigates whether there is a need to include an accurate representation of the gauge package within future hydrocode simulations.
Fossil Gas and the Electromagnetic Precursor of Supermassive Binary Black Hole Mergers
Chang, P; Menou, K; Quataert, E
2009-01-01
Using a one-dimensional height integrated model, we calculate the evolution of an unequal mass binary black hole with a coplanar gas disk that contains a gap due to the presence of the secondary black hole. Viscous evolution of the outer circumbinary disk initially hardens the binary, while the inner disk drains onto the primary (central) black hole. As long as the inner disk remains cool and thin at low $\\dot{M}_{\\rm ext}$ (rather than becoming hot and geometrically thick), the mass of the inner disk reaches an asymptotic mass typically $\\sim 10^{-3}-10^{-4}\\Msun$. Once the semimajor axis shrinks below a critical value, angular momentum losses from gravitational waves dominate over viscous transport in hardening the binary. The inner disk then no longer responds viscously to the inspiraling black holes. Instead, tidal interactions with the secondary rapidly drive the inner disk into the primary. Tidal and viscous dissipation in the inner disk lead to a late time brightening in luminosity $L\\propto t_{\\rm min...
García-Rentería, M. A.; López-Morelos, V. H.; García-Hernández, R.; Dzib-Pérez, L.; García-Ochoa, E. M.; González-Sánchez, J.
2014-12-01
The resistance to localised corrosion of AISI 2205 duplex stainless steel plates joined by Gas Metal Arc Welding (GMAW) under the effect of electromagnetic interaction of low intensity (EMILI) was evaluated with sensitive electrochemical methods. Welds were made using two shielding gas mixtures: 98% Ar + 2% O2 (M1) and 97% Ar + 3% N2 (M2). Plates were welded under EMILI using the M1 gas with constant welding parameters. The modified microstructural evolution in the high temperature heat affected zone and at the fusion zone induced by application of EMILI during welding is associated with the increase of resistance to localised corrosion of the welded joints. Joints made by GMAW using the shielding gas M2 without the application of magnetic field presented high resistance to general corrosion but high susceptibility to undergo localised attack.
Electromagnetic ultrasonic guided waves
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.
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...
ZHANG Wenliang; JIANG Jun; GUO Jian; LU Jiayu
2012-01-01
There will be more and more AC transmission lines near oil/gas pipelines in the future.So in order to determine the safe distance between them,simple and effective methods are required for engineers to efficiently evaluate the electromagnetic effect on oil/gas pipelines due to faults of AC transmission lines.In this paper,an easily handled fitting formula is obtained based on multiple calculation results,which is the maximum voltage on the pipeline anticorrosive coating produced by 1 000 kV AC transmission line under single phase ground fault.Although the calculation results obtained from the fitting formula differ from those gained by precise calculation with softwares,the verification of the formula shows that it is applicable for engineering calculation.This research could be applied to evaluate the electromagnetic effect of 1 000 kV AC transmission line under single-phase ground fault on nearby pipelines,as well as to determine the safe distance or the maximum parallel length.
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....
Brazhnikov, D V; Yudin, V I
2014-01-01
The method for observing the high-contrast and narrow-width resonances of electromagnetically induced absorption (EIA) in the Hanle configuration under counterpropagating light waves is proposed. We theoretically analyze the absorption of a probe light wave in presence of counterpropagating one with the same frequency as the function of a static magnetic field applied along the vectors of light waves, propagating in a vapour cell. Here, as an example, we study a "dark" type of atomic dipole transition Fg=1-->Fe=1 in D1 line of 87Rb, where usually the electromagnetically induced transparency (EIT) can be observed. To obtain the EIA signal one should proper chose the polarizations of light waves and intensities. In contrast of regular schemes for observing EIA signals (in a single travelling light wave in the Hanle configuration or in a bichromatic light field consisted of two travelling waves), the proposed scheme allows one to use buffer gas to significantly enhance properties of the resonance. Also the drama...
Terzija, N.; Yin, W.; Gerbeth, G.; Stefani, F.; Timmel, K.; Wondrak, T.; Peyton, A. J.
2011-01-01
Monitoring of the steel flow through the submerged entry nozzle (SEN) during continuous casting presents a challenge for the instrumentation system because of the high temperature environment and the limited access to the nozzle in between the tundish and the mould. Electromagnetic inductance tomography (EMT) presents an attractive tool to visualize the steel flow profile within the SEN. In this paper, we investigate various flow regimes over a range of stopper positions and gas volume flow rates on a model of a submerged entry nozzle. A scaled (approximately 10:1) experimental rig consisting of a tundish, stopper rod, nozzle and mould was used. Argon gas was injected through the centre of the stopper rod and the behaviour of the two-phase GaInSn/argon flow was studied. The experiments were performed with GaInSn as an analogue for liquid steel, because it has similar conductive properties as molten steel and allows measurements at room temperature. The electromagnetic system used in our experiments to monitor the behaviour of the two-phase GaInSn/argon flow consisted of an array of eight equally spaced induction coils arranged around the object, a data acquisition system and a host computer. The present system operates with a sinusoidal excitation waveform with a frequency of 40 kHz and the system has a capture rate of 40 frames per second. The results show the ability of the system to distinguish the different flow regimes and to detect the individual bubbles. Sample tomographic images given in the paper clearly illustrate the different flow regimes.
Computational electromagnetic-aerodynamics
Shang, Joseph J S
2016-01-01
Presents numerical algorithms, procedures, and techniques required to solve engineering problems relating to the interactions between electromagnetic fields, fluid flow, and interdisciplinary technology for aerodynamics, electromagnetics, chemical-physics kinetics, and plasmadynamics This book addresses modeling and simulation science and technology for studying ionized gas phenomena in engineering applications. Computational Electromagnetic-Aerodynamics is organized into ten chapters. Chapter one to three introduce the fundamental concepts of plasmadynamics, chemical-physics of ionization, classical magnetohydrodynamics, and their extensions to plasma-based flow control actuators, high-speed flows of interplanetary re-entry, and ion thrusters in space exploration. Chapter four to six explain numerical algorithms and procedures for solving Maxwell’s equation in the time domain for computational electromagnetics, plasma wave propagation, and the time-dependent c mpressible Navier-Stokes equation for aerodyn...
Maryam Moazeni
2012-10-01
Full Text Available The nanoparticles of Ti and TiO2 have attracted extensive research interest because of their diverse applications in, for instance, catalysis, energy conversion, pigment and cosmetic manufacturing and biomedical engineering. Through this project, a one-step bulk synthesis method of electromagnetic levitational gas condensation (ELGC was utilized for the synthesis of monodispersed and crystalline Ti and TiO2 nanoparticles. Within the process, the Ti vapours ascending from the high temperature levitated droplet were condensed by an argon gas stream under atmospheric pressure. The TiO2 nanoparticles were produced by simultaneous injection of argon and oxygen into the reactor. The effects of flow rate of the condensing and oxidizing gases on the size and the size distribution of the nanoparticles were investigated. The particles were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD and image analysis. The process parameters for the synthesis of the crystalline Ti and TiO2 nanoparticles were determined.
Milson, James L.
1990-01-01
Three activities involving electromagnetism are presented. Discussed are investigations involving the construction of an electromagnet, the effect of the number of turns of wire in the magnet, and the effect of the number of batteries in the circuit. Extension activities are suggested. (CW)
Bosanac, Slobodan Danko
2016-01-01
This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.
Bosanac, Slobodan Danko [Ruder Boskovic Institute, Zagreb (Croatia). Physical Chemistry
2016-07-01
This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.
Crane, Randolph W.; Marts, Donna J.
1994-01-01
An electromagnetic fastener for manipulating objects in space uses the matic attraction of various metals. An end effector is attached to a robotic manipulating system having an electromagnet such that when current is supplied to the electromagnet, the object is drawn and affixed to the end effector, and when the current is withheld, the object is released. The object to be manipulated includes a multiplicity of ferromagnetic patches at various locations to provide multiple areas for the effector on the manipulator to become affixed to the object. The ferromagnetic patches are sized relative to the object's geometry and mass.
Experimental design of natural and accellerated bone and wood ageing
Facorellis, Y.; Pournou, A.; Richter, Jane;
2015-01-01
This paper presents the experimental design for natural and accelerated ageing of bone and wood samples found in museum conditions that was conceived as part of the INVENVORG (Thales Research Funding Program – NRSF) investigating the effects of the environmental factors on natural organic materials....
Thomas, David T; Hartnett, James P; Hughes, William F
1973-01-01
The applications involving electromagnetic fields are so pervasive that it is difficult to estimate their contribution to the industrial output: generation of electricity, power transmission lines, electric motors, actuators, relays, radio, TV and microwave transmission and reception, magnetic storage, and even the mundane little magnet used to hold a paper note on the refrigerator are all electromagnetic in nature. One would be hard pressed to find a device that works without relaying on any electromagnetic principle or effect. This text provides a good theoretical understanding of the electromagnetic field equations but also treats a large number of applications. In fact, no topic is presented unless it is directly applicable to engineering design or unless it is needed for the understanding of another topic. In electrostatics, for example, the text includes discussions of photocopying, ink-jet printing, electrostatic separation and deposition, sandpaper production, paint spraying, and powder coating. In ma...
... causes cancer. Some people worry that wireless and cellular phones cause cancer or other health problems. The phones do give off radio-frequency energy (RF), a form of electromagnetic radiation. So far, scientific evidence has not found a ...
Kim, Jihoon; Um, Evan; Moridis, George
2014-12-01
We investigate fracture propagation induced by hydraulic fracturing with water injection, using numerical simulation. For rigorous, full 3D modeling, we employ a numerical method that can model failure resulting from tensile and shear stresses, dynamic nonlinear permeability, leak-off in all directions, and thermo-poro-mechanical effects with the double porosity approach. Our numerical results indicate that fracture propagation is not the same as propagation of the water front, because fracturing is governed by geomechanics, whereas water saturation is determined by fluid flow. At early times, the water saturation front is almost identical to the fracture tip, suggesting that the fracture is mostly filled with injected water. However, at late times, advance of the water front is retarded compared to fracture propagation, yielding a significant gap between the water front and the fracture top, which is filled with reservoir gas. We also find considerable leak-off of water to the reservoir. The inconsistency between the fracture volume and the volume of injected water cannot properly calculate the fracture length, when it is estimated based on the simple assumption that the fracture is fully saturated with injected water. As an example of flow-geomechanical responses, we identify pressure fluctuation under constant water injection, because hydraulic fracturing is itself a set of many failure processes, in which pressure consistently drops when failure occurs, but fluctuation decreases as the fracture length grows. We also study application of electromagnetic (EM) geophysical methods, because these methods are highly sensitive to changes in porosity and pore-fluid properties due to water injection into gas reservoirs. Employing a 3D finite-element EM geophysical simulator, we evaluate the sensitivity of the crosswell EM method for monitoring fluid movements in shaly reservoirs. For this sensitivity evaluation, reservoir models are generated through the coupled flow
2012-03-01
DISTRIBUTION STATEMENT A: Approved for Public Release Electromagnetic Railgun ASNE Combat System Symposium 26-29 March 2012 CAPT Mike...4. TITLE AND SUBTITLE Electromagnetic Railgun 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER...Defense 3/29/2012 Slide 5 Distribution A Naval Railgun – Key Elements Capacitors or Rotating Machines Ship Integration Launcher Projectile
Cermak, Daniel; Okutsu, Ayaka; Jørgensen, Stina Marie Hasse
2015-01-01
Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015.......Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015....
Cermak, Daniel; Okutsu, Ayaka; Hasse, Stina
2015-01-01
Electromagnetic Landscape demonstrates in direct, tangible and immediate ways effects of the disruption of the familiar. An ubiquitous technological medium, FM radio, is turned into an alien and unfamiliar one. Audience participation, the environment, radio signals and noise create a site...
Computational Electromagnetics
Rylander, Thomas; Bondeson, Anders
2013-01-01
Computational Electromagnetics is a young and growing discipline, expanding as a result of the steadily increasing demand for software for the design and analysis of electrical devices. This book introduces three of the most popular numerical methods for simulating electromagnetic fields: the finite difference method, the finite element method and the method of moments. In particular it focuses on how these methods are used to obtain valid approximations to the solutions of Maxwell's equations, using, for example, "staggered grids" and "edge elements." The main goal of the book is to make the reader aware of different sources of errors in numerical computations, and also to provide the tools for assessing the accuracy of numerical methods and their solutions. To reach this goal, convergence analysis, extrapolation, von Neumann stability analysis, and dispersion analysis are introduced and used frequently throughout the book. Another major goal of the book is to provide students with enough practical understan...
Aldridge, David F.
2014-11-01
A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories
Electromagnetic waves and photons
Hofmann, Ralf
2015-01-01
We explore how the thermal ground states of two mixing and pure SU(2) Yang-Mills theories, SU(2)$_{\\tiny\\mbox{CMB}}$ of scale $\\Lambda_{\\tiny\\mbox{CMB}}\\sim 10^{-4}\\,$eV and SU(2)$_{e}$ of scale $\\Lambda_{e}\\sim 5\\times 10^5\\,$eV, associate either wave or particle aspects to electromagnetic disturbances during thermalisation towards the photon gas of a blackbody, in realising the photoelectric effect, and through the frequency dependence of the monochromatic, nonthermal beam structure in Thomson/Compton scattering.
Ida, Nathan
2015-01-01
This book provides students with a thorough theoretical understanding of electromagnetic field equations and it also treats a large number of applications. The text is a comprehensive two-semester textbook. The work treats most topics in two steps – a short, introductory chapter followed by a second chapter with in-depth extensive treatment; between 10 to 30 applications per topic; examples and exercises throughout the book; experiments, problems and summaries. The new edition includes: updated end of chapter problems; a new introduction to electromagnetics based on behavior of charges; a new section on units; MATLAB tools for solution of problems and demonstration of subjects; most chapters include a summary. The book is an undergraduate textbook at the Junior level, intended for required classes in electromagnetics. It is written in simple terms with all details of derivations included and all steps in solutions listed. It requires little beyond basic calculus and can be used for self-study. The weal...
Electromagnetic theory for electromagnetic compatibility engineers
Toh, Tze-Chuen
2013-01-01
Engineers and scientists who develop and install electronic devices and circuits need to have a solid understanding of electromagnetic theory and the electromagnetic behavior of devices and circuits. In particular, they must be well-versed in electromagnetic compatibility, which minimizes and controls the side effects of interconnected electric devices. Designed to entice the practical engineer to explore some worthwhile mathematical methods, and to reorient the theoretical scientist to industrial applications, Electromagnetic Theory for Electromagnetic Compatibility Engineers is based on the
魏刚
2011-01-01
Aimed at realizing the dynamic and continuous monitoring of coal and gas outburst,this paper describes an analysis of the relationship between electromagnetic radiation strength and stress of coal and rock mass,according to the coal and rock strength statistic damaging theory,and development of a dynamic casualty-electromagnetic radiation response coupled model for charactering the rock with different poisson＇s ratio.A continuous monitoring of central tunnel of 1200 working face and return air course tunnel of 1204 working face of Hongling Coal Mine which belong to Shenyang Coal Trade Group Corporation Limited Liability Company for predicting the coal and gas outburst by using a KBD7 online electromagnetic radiation monitoring instrument developed,based on the coupled model,shows that there are a strong correlations between electromagnetic radiation strength and conventional predicting indexes and outburst risk.1200 exploiting working face has the critical electromagnetic radiation value of 49 mV.This working face shows an accuracy of prediction for non-outburst of 100%,and accuracy of prediction for outburst of 70% or more.The outburst situation is not yet predicted in 1204 working face.The prediction of the risk of coal and gas outburst using electromagnetic radiation allows a dynamic,continuous,non-contacting,directional and regional test with no need of drilling,providing technical support for safe production in coal mines.%为实现煤与瓦斯突出危险性的动态、连续预测,根据煤岩强度统计损伤理论,分析煤岩电磁辐射强度与应力关系,建立不同泊松比煤岩动力灾害与电磁辐射响应模型。利用基于该模型研制的KBD7在线式电磁辐射监测仪,对沈阳煤业集团红菱煤矿1200工作面集中运输巷和1204工作面回风顺槽进行连续监测,预测两工作面的煤与瓦斯突出危险性。结果表明：电磁辐射强度与常规预测指标、煤与瓦斯突出
Sobouti, Yousef
2013-01-01
That the universal constancy of the speed of light is a logical consequence of Maxwell's equations is common knowledge. Here we show that the converse is also true. That is, electromagnetism (EM) and electrodynamics (ED) in all their details can be derived from the simple assumption that the speed of light is a universal constant. The consequences reach far. Conventional EM and ED are observation based. The alternative we propose spares all observational foundations of EM, only to reintroduce them as theoretically derived and empiricism-free laws of Nature. Simplicity is beauty and there are merits to it. For instance, if $\
What Are Electromagnetic Fields?
... sources of electromagnetic fields Besides natural sources the electromagnetic spectrum also includes fields generated by human-made sources: ... ability to break bonds between molecules. In the electromagnetic spectrum, gamma rays given off by radioactive materials, cosmic ...
Gravito-electromagnetism versus electromagnetism
Tartaglia, A; Ruggiero, M L [Dipartimento di Fisica, Politecnico and INFN, 10129 Torino (Italy)
2004-03-01
The properties of the gravito-magnetic interaction in non-stationary conditions are discussed. A direct deduction of the equivalent Faraday-Henry law is given. A comparison is made between gravito-magnetic and electromagnetic induction, and it is shown that there is no Meissner-like effect for superfluids in the field of massive spinning bodies. The impossibility of stationary motions in directions not along the lines of the gravito-magnetic field is found. Finally the results are discussed in relation to the behaviour of superconductors.
Electromagnetic topology: Characterization of internal electromagnetic coupling
Parmantier, J. P.; Aparicio, J. P.; Faure, F.
1991-01-01
The main principles are presented of a method dealing with the resolution of electromagnetic internal problems: Electromagnetic Topology. A very interesting way is to generalize the multiconductor transmission line network theory to the basic equation of the Electromagnetic Topology: the BLT equation. This generalization is illustrated by the treatment of an aperture as a four port junction. Analytical and experimental derivations of the scattering parameters are presented. These concepts are used to study the electromagnetic coupling in a scale model of an aircraft, and can be seen as a convenient means to test internal electromagnetic interference.
Topological Foundations of Electromagnetism
Barrett, Terrence W
2008-01-01
Topological Foundations of Electromagnetism seeks a fundamental understanding of the dynamics of electromagnetism; and marshals the evidence that in certain precisely defined topological conditions, electromagnetic theory (Maxwell's theory) must be extended or generalized in order to provide an explanation and understanding of, until now, unusual electromagnetic phenomena. Key to this generalization is an understanding of the circumstances under which the so-called A potential fields have physical effects. Basic to the approach taken is that the topological composition of electromagnetic field
Kolm, H.; Mongeau, P.; Williams, F.
1980-09-01
Recent advances in energy storage, switching and magnet technology make electromagnetic acceleration a viable alternative to chemical propulsion for certain tasks, and a means to perform other tasks not previously feasible. Applications include the acceleration of gram-size particles for hypervelocity research and the initiation of fusion by impact, a replacement for chemically propelled artillery, the transportation of cargo and personnel over inaccessible terrain, and the launching of space vehicles to supply massive space operations, and for the disposal of nuclear waste. The simplest launcher of interest is the railgun, in which a short-circuit slide or an arc is driven along two rails by direct current. The most sophisticated studied thus far is the mass driver, in which a superconducting shuttle bucket is accelerated by a line of pulse coils energized by capacitors at energy conversion efficiencies better than 90%. Other accelerators of interest include helical, brush-commutated motors, discrete coil arc commutated drivers, flux compression momentum transformers, and various hybrid electrochemical devices.
Nature of electromagnetic radiation of a coal seam
Frid, V.I.; Shabarov, A.N.; Proskuryakov, V.M.; Baranov, V.A. (Rossiiskaya Akademiya Nauk (Russian Federation))
1992-03-01
Analyzes feasibility of forecasting rock burst hazards on the basis of electromagnetic radiation of a coal seam. Electromagnetic radiation emitted by coal seams situated at depths from 300 to 750 m in a number of coal mines in the Kuzbass was investigated. The investigations were carried out both in coal seams prone to rock bursts and in those without rock burst hazards. Effects of the following factors on the level of electromagnetic radiation were analyzed: moisture content in coal seams, coal mechanical properties, porosity, state of stress, microcracking of coal seams caused by stress concentration, gas desorption from coal. Analyses show that electromagnetic emission supplied reliable information on rock burst hazards. Use of a frequency of about 100 Hz for measuring electromagnetic radiation is recommended. Rock burst forecasting based on measuring electromagnetic radiation of a coal seam was compared to methods based on measuring the rate of cuttings leaving test boreholes and the velocity of gas emitted from the boreholes. 11 refs.
Butzmann, S.
2000-07-01
A method for sensorless control of the impact speed of the armature of electromagnetic actuators is presented and described in great detail. The control algorithm was implemented in a compact electronic control unit for a 4-cylinder, 16-valve engine and was tested both in the laboratory and in a real engine. The method was first presented in September 1999 at the Frankfurt IHH, where it met with great interest. [German] In dieser Arbeit wurde ein Verfahren zur sensorlosen Regelung der Aufsetzgeschwindigkeit des Ankers bei elektromagnetischen Aktuatoren vorgestellt. Um den Anker zwischen den beiden Seiten des Luftspalts zu bewegen, werden zwei Elektromagnete abwechselnd bestromt, die Bewegung wird dabei von zwei Federn unterstuetzt. Fliesst waehrend eines solchen Umschwingvorgangs ein konstanter Strom durch die Spulen, so nimmt waehrend der Annaeherung an die Polflaeche die Magnetkraft mit der Luftspaltlaenge 1/l{sub L}{sup 2} zu, waehrend die entgegengesetzt wirkende Federkraft nur linear mit der Luftspaltlaenge l{sub L} steigt. Dies fuehrt prinzipiell zu einer unerwuenschten Beschleunigung des Ankers am Ende der Bewegung und damit zu einem harten Aufprall, der Laerm erzeugt und die Aktuatorlebensdauer reduziert. Ausgehend vom idealen Verfahren der zeitoptimalen Regelung, welches allerdings hohe Anforderungen an Sensorik und Rechenleistung stellt, wurde ein Algorithmus hergeleitet, welcher die zur Regelung der Aufsetzgeschwindigkeit erforderlichen Signale aus dem Stromverlauf in den Aktuatorspulen ableitet. Das neue Regelverfahren umgeht daher die Probleme, die durch den Einsatz von Sensoren entstehen. Waehrend der Ankerbewegung werden die Spulen zusaetzlich stimuliert, um eine hoehere Observationsgenauigkeit zu erzielen. Durch Adaption zwischen zwei aufeinanderfolgenden Ventilbetaetigungen und Regelung der Bewegung waehrend der Flugphase kann die Aufsetzgeschwindigkeit des Ankers praezise geregelt werden. Gleichzeitig konnte die zur Regelung erforderliche
Electromagnetic Education in India
Bajpai, Shrish; Asif, Siddiqui Sajida; Akhtar, Syed Adnan
2016-01-01
Out of the four fundamental interactions in nature, electromagnetics is one of them along with gravitation, strong interaction and weak interaction. The field of electromagnetics has made much of the modern age possible. Electromagnets are common in day-to-day appliances and are becoming more conventional as the need for technology increases.…
Electromagnetic properties of neutrinos
Ould-Saada, F. [Zurich Univ. (Switzerland). Inst. fuer Physik
1996-11-01
Electromagnetic properties of neutrinos and their implications are discussed, and the experimental situation summarised. Spin precession in solar magnetic fields presents a solution of the solar neutrino problem. A magnetic moment, {mu}{sub {nu}}, of the order of 10{sup -11} {mu}{sub B} would be needed. In the simplest extension of the standard model, with no-vanishing neutrino masses, dipole moment interactions are allowed through higher order processes. A neutrino mass of {approx_equal}10 eV would give {mu}{sub {nu}}{approx_equal}10{sup -18} {mu}{sub B}, much smaller than the present experimental upper limit of 2x10{sup -10} {mu}{sub B}. Although model-dependent, upper bounds on dipole moments from astrophysics and cosmology are 10 to 100 times more stringent. Any values of {mu}{sub {nu}}, larger than the SM predictions, would then signal the onset of new physics. Among the processes sensitive to the magnetic moment, {nu}e{sup -} scattering presents two advantages: it is a pure weak, theoretically well understood process, and the recoil electron can be easily measured. A hypothetical electromagnetic contribution to the cross-section would dominate at low energies. A low background detector, MUNU, being built at the Bugey nuclear reactor is presented.It is based on a gas TPC, surrounded by a scintillator. The threshold on the electron recoil energy can be set very low, around 500 keV, giving the experiment a good sensitivity to the magnetic moment of the {nu}{sub e}, extending down to 2x10{sup -11} {mu}{sub B}. (author) 15 figs., 5 tabs., 96 refs.
Applied Electromagnetism and Materials
Moliton, André
2007-01-01
Applied Electromagnetism and Materials picks up where the author's Basic Electromagnetism and Materials left off by presenting practical and relevant technological information about electromagnetic material properties and their applications. This book is aimed at senior undergraduate and graduate students as well as researchers in materials science and is the product of many years of teaching basic and applied electromagnetism. Topics range from the spectroscopy and characterization of dielectrics and semiconductors, to non-linear effects and electromagnetic cavities, to ion-beam applications in materials science.
Theory of electromagnetic fields
Wolski, Andrzej
2011-01-01
We discuss the theory of electromagnetic fields, with an emphasis on aspects relevant to radiofrequency systems in particle accelerators. We begin by reviewing Maxwell's equations and their physical significance. We show that in free space, there are solutions to Maxwell's equations representing the propagation of electromagnetic fields as waves. We introduce electromagnetic potentials, and show how they can be used to simplify the calculation of the fields in the presence of sources. We derive Poynting's theorem, which leads to expressions for the energy density and energy flux in an electromagnetic field. We discuss the properties of electromagnetic waves in cavities, waveguides and transmission lines.
The CPLEAR Electromagnetic Calorimeter
Adler, R; Bal, F; Behnke, O; Bloch, P; Damianoglou, D; Dechelette, Paul; Dröge, M; Eckart, B; Felder, C; Fetscher, W; Fidecaro, Maria; Garreta, D; Gerber, H J; Gumplinger, P; Guyon, D; Johner, H U; Löfstedt, B; Kern, J; Kokkas, P; Krause, H; Mall, U; Marin, C P; Nanni, F; Pagels, B; Pavlopoulos, P; Petit, P; Polivka, G; Rheme, C; Ruf, T; Santoni, C; Schaller, L A; Schopper, A; Tauscher, Ludwig; Tschopp, H; Weber, P; Wendler, H; Witzig, C; Wolter, M
1997-01-01
A large-acceptance lead/gas sampling electromagnetic calorimeter (ECAL) was constructed for the CPLEAR experiment to detect photons from decays of $\\pi^0$s with momentum $p_{\\pi^0} \\le 800$ MeV$/c$. The main purpose of the ECAL is to determine the decay vertex of neutral-kaon decays $\\ko \\rightarrow \\pi^0\\pi^0 \\rightarrow 4 \\gamma$ and $\\ko \\rightarrow \\pi^0\\pi^0\\pi^0 \\rightarrow 6 \\gamma$. This requires a position-sensitive photon detector with high spatial granularity in $r$-, $\\varphi$-, and $z$-coordinates. The ECAL --- a barrel without end-caps located inside a magnetic field of 0.44 T --- consists of 18 identical concentric layers. Each layer of $1/3$ radiation length (X${_0}$) contains a converter plate followed by small cross-section high-gain tubes of 2640 mm active length which are sandwiched by passive pick-up strip plates. The ECAL, with a total of $6$ X${_0}$, has an energy resolution of $\\sigma (E)/E \\approx 13\\% / \\sqrt{E(\\mathrm{GeV})}$ and a position resolution of 4.5 mm for the shower foot. ...
Basic Electromagnetism and Materials
Moliton, André
2007-01-01
Basic Electromagnetism and Materials is the product of many years of teaching basic and applied electromagnetism. This textbook can be used to teach electromagnetism to a wide range of undergraduate science majors in physics, electrical engineering or materials science. However, by making lesser demands on mathematical knowledge than competing texts, and by emphasizing electromagnetic properties of materials and their applications, this textbook is uniquely suited to students of materials science. Many competing texts focus on the study of propagation waves either in the microwave or optical domain, whereas Basic Electromagnetism and Materials covers the entire electromagnetic domain and the physical response of materials to these waves. Professor André Moliton is Director of the Unité de Microélectronique, Optoélectronique et Polymères (Université de Limoges, France), which brings together three groups studying the optoelectronics of molecular and polymer layers, micro-optoelectronic systems for teleco...
Static electromagnetic frequency changers
Rozhanskii, L L
1963-01-01
Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work
Model for Electromagnetic Information Leakage
Mao Jian; Li Yongmei; Zhang Jiemin; Liu Jinming
2013-01-01
Electromagnetic leakage will happen in working information equipments; it could lead to information leakage. In order to discover the nature of information in electromagnetic leakage, this paper combined electromagnetic theory with information theory as an innovative research method. It outlines a systematic model of electromagnetic information leakage, which theoretically describes the process of information leakage, intercept and reproduction based on electromagnetic radiation, and ana...
Electromagnetic Interface Testing Facility
Federal Laboratory Consortium — The Electromagnetic Interface Testing facilitysupports such testing asEmissions, Field Strength, Mode Stirring, EMP Pulser, 4 Probe Monitoring/Leveling System, and...
Slewing crane with electromagnet
2006-01-01
This paper describes a slewing crane with electromagnet, operated by three three-phase induction motors. A switchboard described in a separate paper, which also depicts the electromagnet construction details, drives the motors and the electromagnet. From its seat – mounted on the crane - an operator can make the crane arm slew left or right. The electromagnet can be moved back, forward, up or down. The crane is made of iron, has a height of 3m and a length of 2,5m. Such proportions make it ve...
Fundamentals of engineering electromagnetism
Kim, Nam; Yoon, Youngro; Jun, Sukhee; Jun, Hoin
2004-08-15
It indicates fundamentals of engineering electromagnetism. It mentions electromagnetic field model of introduction and International system of units and universal constant, Vector analysis with summary and orthogonal coordinate systems, electrostatic field on Coulomb's law and Gauss's law, electrostatic energy and strength, steady state current with Ohm's law and Joule's law and calculation of resistance, crystallite field with Vector's electrostatic potential, Biot-Savart law and application and Magnetic Dipole, time-Savart and Maxwell equation with potential function and Faraday law of electromagnetic induction, plane electromagnetic wave, transmission line, a wave guide and cavity resonator and antenna arrangement.
Large electromagnetic pumps. [LMFBR
Kilman, G.B.
1976-01-01
The development of large electromagnetic pumps for the liquid metal heat transfer systems of fission reactors has progressed for a number of years. Such pumps are now planned for fusion reactors and solar plants as well. The Einstein-Szilard (annular) pump has been selected as the preferred configuration. Some of the reasons that electromagnetic pumps may be preferred over mechanical pumps and why the annular configuration was selected are discussed. A detailed electromagnetic analysis of the annular pump, based on slug flow, is presented. The analysis is then used to explore the implications of large size and power on considerations of electromagnetic skin effect, geometric skin effect and the cylindrical geometry.
Electromagnetic wave collapse in a radiation background.
Marklund, Mattias; Brodin, Gert; Stenflo, Lennart
2003-10-17
The nonlinear interaction, due to quantum electrodynamical (QED) effects between an electromagnetic pulse and a radiation background, is investigated by combining the methods of radiation hydrodynamics with the QED theory for photon-photon scattering. For the case of a single coherent electromagnetic pulse, we obtain a Zakharov-like system, where the radiation pressure of the pulse acts as a driver of acoustic waves in the photon gas. For a sufficiently intense pulse and/or background energy density, there is focusing and the subsequent collapse of the pulse. The relevance of our results for various astrophysical applications are discussed.
Introducing Electromagnetic Field Momentum
Hu, Ben Yu-Kuang
2012-01-01
I describe an elementary way of introducing electromagnetic field momentum. By considering a system of a long solenoid and line charge, the dependence of the field momentum on the electric and magnetic fields can be deduced. I obtain the electromagnetic angular momentum for a point charge and magnetic monopole pair partially through dimensional…
An Electromagnetic Beam Converter
2009-01-01
The present invention relates to an electromagnetic beam converter and a method for conversion of an input beam of electromagnetic radiation having a bell shaped intensity profile a(x,y) into an output beam having a prescribed target intensity profile l(x',y') based on a further development...
High frequency electromagnetic dosimetry
Sánchez-Hernández, David A
2009-01-01
Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.
Tunability enhanced electromagnetic wiggler
Schlueter, Ross D.; Deis, Gary A.
1992-01-01
The invention discloses a wiggler used in synchrotron radiation sources and free electron lasers, where each pole is surrounded by at least two electromagnetic coils. The electromagnetic coils are energized with different amounts of current to provide a wide tunable range of the on-axis magnetic flux density, while preventing magnetic saturation of the poles.
Tudorel Ene
2016-10-01
Full Text Available The paper refers to the design of a direct current electromagnet, located on the head of a swan neck welding gun of a MIG welding equipment and used for magnetising the rotation space of two additional electric arches, in order to preheat the electrode wire and of the protective gas, partially turned into plasma jet. We present the constructive - electromagnetic dimensioning and the verification of the electromagnet operation.
Computer techniques for electromagnetics
Mittra, R
1973-01-01
Computer Techniques for Electromagnetics discusses the ways in which computer techniques solve practical problems in electromagnetics. It discusses the impact of the emergence of high-speed computers in the study of electromagnetics. This text provides a brief background on the approaches used by mathematical analysts in solving integral equations. It also demonstrates how to use computer techniques in computing current distribution, radar scattering, and waveguide discontinuities, and inverse scattering. This book will be useful for students looking for a comprehensive text on computer techni
Nonlinear surface electromagnetic phenomena
Ponath, H-E
1991-01-01
In recent years the physics of electromagnetic surface phenomena has developed rapidly, evolving into technologies for communications and industry, such as fiber and integrated optics. The variety of phenomena based on electromagnetism at surfaces is rich and this book was written with the aim of summarizing the available knowledge in selected areas of the field. The book contains reviews written by solid state and optical physicists on the nonlinear interaction of electromagnetic waves at and with surfaces and films. Both the physical phenomena and some potential applications are
High frequency electromagnetic tomography
Daily, W.; Ramirez, A.; Ueng, T.; Latorre, R.
1989-09-01
An experiment was conducted in G Tunnel at the Nevada Test Site to evaluate high frequency electromagnetic tomography as a candidate for in situ monitoring of hydrology in the near field of a heater placed in densely welded tuff. Tomographs of 200 MHz electromagnetic permittivity were made for several planes between boreholes. Data were taken before the heater was turned on, during heating and during cooldown of the rockmass. This data is interpreted to yield maps of changes in water content of the rockmass as a function of time. This interpretation is based on laboratory measurement of electromagnetic permittivity as a function of water content for densely welded tuff. 8 refs., 6 figs.
Electromagnetic analysis of electromagnet for control element drive mechanism
Huh, Hyung; Kim, J.I.; Kim, J.H.; Kim, Y.W. [Korea Atomic Energy Research Institute, Taejon (Korea)
1999-06-01
A 2-D electromagnetic numerical analysis model is developed to calculate the attraction force of the electromagnet for CEDM. trend relating to electromagnetic design within constrained. The important design variables of the electromagnet are current density and air gap length. The results show that the attraction force by using optimum design point is well within the acceptable level. It is anticipated that the results will eventually be utilized for more realitic design of the electromagnet. 10 refs., 38 figs., 2 tabs. (Author)
Electromagnetic fields and waves
Rojansky, Vladimir
2012-01-01
This comprehensive introduction to classical electromagnetic theory covers the major aspects, including scalar fields, vectors, laws of Ohm, Joule, Coulomb, Faraday, Maxwell's equation, and more. With numerous diagrams and illustrations.
OPAL detector electromagnetic calorimeter
1988-01-01
Half of the electromagnetic calorimeter of the OPAL detector is seen in this photo. This calorimeter consists of 4720 blocks of lead glass. It was used to detect and measure the energy of photons, electrons and positrons by absorbing them.
BGO* electromagnetic calorimeter
CERN
1988-01-01
* Short for Bismuth-Germanium-Oxyde, a scintillator of high atomic number Z used in electromagnetic crystal calorimeters. BGO is characterized by fast rise time (a few nanoseconds) and short radiation length (1.11 cm).
The classical electromagnetic field
Eyges, Leonard
2010-01-01
This excellent text covers a year's course in advanced theoretical electromagnetism, first introducing theory, then its application. Topics include vectors D and H inside matter, conservation laws for energy, momentum, invariance, form invariance, covariance in special relativity, and more.
Electromagnetism in the Movies.
Everitt, Lori R.; Patterson, Evelyn T.
1999-01-01
Describes how the authors used portions of popular movies to help students review concepts related to electromagnetism. Movies used and concepts covered in the review are listed, and a sample activity is described. (WRM)
Electromagnetic rotational actuation.
Hogan, Alexander Lee
2010-08-01
There are many applications that need a meso-scale rotational actuator. These applications have been left by the wayside because of the lack of actuation at this scale. Sandia National Laboratories has many unique fabrication technologies that could be used to create an electromagnetic actuator at this scale. There are also many designs to be explored. In this internship exploration of the designs and fabrications technologies to find an inexpensive design that can be used for prototyping the electromagnetic rotational actuator.
The ATLAS electromagnetic calorimeter
Maximilien Brice
2003-01-01
Michel Mathieu, a technician for the ATLAS collaboration, is cabling the ATLAS electromagnetic calorimeter's first end-cap, before insertion into its cryostat. Millions of wires are connected to the electromagnetic calorimeter on this end-cap that must be carefully fed out from the detector so that data can be read out. Every element on the detector will be attached to one of these wires so that a full digital map of the end-cap can be recreated.
Electromagnetic Education in India
Bajpai Shrish
2016-06-01
Full Text Available Out of the four fundamental interactions in nature, electromagnetics is one of them along with gravitation, strong interaction and weak interaction. The field of electromagnetics has made much of the modern age possible. Electromagnets are common in day-to-day appliances and are becoming more conventional as the need for technology increases. Electromagnetism has played a vital role in the progress of human kind ever since it has been understood. Electromagnets are found everywhere. One can find them in speakers, doorbells, home security systems, anti-shoplifting systems, hard drives, mobiles, microphones, Maglev trains, motors and many other everyday appliances and products. Before diving into the education system, it is necessary to reiterate its importance in various technologies that have evolved over time. Almost every domain of social life has electromagnetic playing its role. Be it the mobile vibrators you depend upon, a water pump, windshield wipers during rain and the power windows of your car or even the RFID tags that may ease your job during shopping. A flavor of electromagnetics is essential during primary level of schooling for the student to understand its future prospects and open his/her mind to a broad ocean of ideas. Due to such advancements this field can offer, study on such a field is highly beneficial for a developing country like India. The paper presents the scenario of electromagnetic education in India, its importance and numerous schemes taken by the government of India to uplift and acquaint the people about the importance of EM and its applications.
Electromagnetic reverberation chambers
Besnier, Philippe
2013-01-01
Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc
Inhomogeneous electromagnetic gravitational collapse
Stein-Schabes, J.A.
1985-04-15
The collapse of an inhomogeneous dust cloud in the presence of an electromagnetic field is investigated in detail. The possibility of a naked singularity arising is studied using some known solutions for a spherical charged inhomogeneous dust cloud. It is found that locally naked singularities may develop when the arbitrary functions in the solution are chosen in a special way, but that a global naked singularity will not form. Also the role of the electromagnetic pressure is discussed.
Model for Electromagnetic Information Leakage
Mao Jian
2013-09-01
Full Text Available Electromagnetic leakage will happen in working information equipments; it could lead to information leakage. In order to discover the nature of information in electromagnetic leakage, this paper combined electromagnetic theory with information theory as an innovative research method. It outlines a systematic model of electromagnetic information leakage, which theoretically describes the process of information leakage, intercept and reproduction based on electromagnetic radiation, and analyzes amount of leakage information with formulas.
Covariant electromagnetic field lines
Hadad, Y.; Cohen, E.; Kaminer, I.; Elitzur, A. C.
2017-08-01
Faraday introduced electric field lines as a powerful tool for understanding the electric force, and these field lines are still used today in classrooms and textbooks teaching the basics of electromagnetism within the electrostatic limit. However, despite attempts at generalizing this concept beyond the electrostatic limit, such a fully relativistic field line theory still appears to be missing. In this work, we propose such a theory and define covariant electromagnetic field lines that naturally extend electric field lines to relativistic systems and general electromagnetic fields. We derive a closed-form formula for the field lines curvature in the vicinity of a charge, and show that it is related to the world line of the charge. This demonstrates how the kinematics of a charge can be derived from the geometry of the electromagnetic field lines. Such a theory may also provide new tools in modeling and analyzing electromagnetic phenomena, and may entail new insights regarding long-standing problems such as radiation-reaction and self-force. In particular, the electromagnetic field lines curvature has the attractive property of being non-singular everywhere, thus eliminating all self-field singularities without using renormalization techniques.
Electromagnetic cellular interactions.
Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan
2011-05-01
Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.
Electromagnetic Signatures of SMBH Coalescence
Schnittman, Jeremy
2012-01-01
When two supermassive black holes (SMBHs) approach within 1-10 mpc, gravitational wave (GW) losses begin to dominate the evolution of the binary, pushing the system to merge in a relatively small time. During this final inspiral regime, the system will emit copious energy in GWs, which should be directly detectable by pulsar timing arrays and space-based interferometers. At the same time, any gas or stars in the immediate vicinity of the merging 5MBHs can get heated and produce bright electromagnetic (EM) counterparts to the GW signals. We present here a number of possible mechanisms by which simultaneous EM and GW signals will yield valuable new information about galaxy evolution, accretion disk dynamics, and fundamental physics in the most extreme gravitational fields.
Electromagnetic Gun Circuit Analysis Code (EGCAC)
Rolader, Glenn E.; Thornhill, Lindsey D.; Batteh, Jad H.; Scanlon, James J., III
1993-01-01
This paper describes a system engineering code that simulates the performance of a railgun/power supply system. The code, named EGCAC (Electromagnetic Gun Circuit Analysis Code), accounts for many performance degrading effects including viscous drag on the armature, viscous drag on the gas being pushed in front of the projectile, entrained gas that must be accelerated in front of the projectile, time-dependent rail resistance, armature resistance, system resistance, and ablation drag. EGCAC has been utilized to predict railgun performance up to a velocity of approximately 4 km/s for experiments at several laboratories. In this paper, the theory of EGCAC is described, and sample calculations are presented.
Applied electromagnetic scattering theory
Osipov, Andrey A
2017-01-01
Besides classical applications (radar and stealth, antennas, microwave engineering), scattering and diffraction are enabling phenomena for some emerging research fields (artificial electromagnetic materials or metamaterials, terahertz technologies, electromagnetic aspects of nano-science). This book is a tutorial for advanced students who need to study diffraction theory. The textbook gives fundamental knowledge about scattering and diffraction of electromagnetic waves and provides some working examples of solutions for practical high-frequency scattering and diffraction problems. The book focuses on the most important diffraction effects and mechanisms influencing the scattering process and describes efficient and physically justified simulation methods - physical optics (PO) and the physical theory of diffraction (PTD) - applicable in typical remote sensing scenarios. The material is presented in a comprehensible and logical form, which relates the presented results to the basic principles of electromag...
Electromagnetic pollution. Screens accused
Vincent, J.
1996-04-01
A recent experiment carried out by M. Bastide (Montpellier University, France) has shown an important increase of mortality, immunosuppression and morphological changes for chicks embryos when submitted to the very low frequency electromagnetic field of a personal computer screen during incubation. Similar effects on pregnant women working in front of cathode ray tubes have never been demonstrated. The paper gives an overview of the epidemiological studies carried out so far to determine the possible noxious effects of electromagnetic fields on public health. In particular, EdF (Electricite de France) has started three different inquiries involving 400000 workmens from electric power industry in order to determine some possible correlation between the exposure to electromagnetic fields and the occurrence of leukemias, brain tumors and melanomas. William Dab, from EdF Medical Studies Service indicates that only a very small relation with the occurrence of brain tumors and acute myeloid leukemias have been shown so far. (J.S.). 4 refs., 2 photos.
Valagiannopoulos, Constantinos A; Simovski, Constantin R; Tretyakov, Sergei A; Maslovski, Stanislav I
2015-01-01
The ideal black body fully absorbs all incident rays, that is, all propagating waves created by arbitrary sources. The known idealized realization of a black body is the perfectly matched layer (PML), widely used in numerical electromagnetics. However, ideal black bodies and PMLs do not interact with evanescent fields existing near any finite-size source, and the energy stored in these fields cannot be harvested. Here we introduce the concept of the ideal conjugate matched layer (CML), which fully absorbs energy of both propagating and evanescent fields of sources acting as an ideal sink for electromagnetic energy. Conjugate matched absorbers have exciting application potentials, as resonant attractors of electromagnetic energy into the absorber volume. We derive the conditions on the constitutive parameters of media which can serve as CML materials, numerically study the performance of planar and cylindrical CML and discuss possible realizations of such materials as metal-dielectric composites.
Aircraft electromagnetic compatibility
Clarke, Clifton A.; Larsen, William E.
1987-06-01
Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.
Electromagnetic induction studies
Hermance, J. F.
1983-04-01
Recent developments in electromagnetic induction studies of the lithosphere and the asthenosphere are reviewed. Attention is given to geoelectrical studies of active tectonic areas in terms of the major zones of crustal extension, the basin and range province along western regions of North America, and the Rio Grande rift. Studies have also been performed of tectonic activity around Iceland, the Salton Trough and Cerro Prieto, and the subduction zones of the Cascade Mountains volcanic belt, where magnetotelluric and geomagnetic variation studies have been done. Geomagnetic variations experiments have been reported in the Central Appalachians, and submarine electromagnetic studies along the Juan de Fuca ridge. Controlled source electromagnetic and dc resistivity investigations have been carried out in Nevada, Hawaii, and in the Adirondacks Mountains. Laboratory examinations on the conductivity of representative materials over a broad range of temperature, pressure, and chemistry are described.
Superconducting dipole electromagnet
Purcell, John R.
1977-07-26
A dipole electromagnet of especial use for bending beams in particle accelerators is wound to have high uniformity of magnetic field across a cross section and to decrease evenly to zero as the ends of the electromagnet are approached by disposing the superconducting filaments of the coil in the crescent-shaped nonoverlapping portions of two intersecting circles. Uniform decrease at the ends is achieved by causing the circles to overlap increasingly in the direction of the ends of the coil until the overlap is complete and the coil is terminated.
Improved Electromagnetic Brake
Martin, Toby B.
2004-01-01
A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may
Dynamic electromagnetic metamaterials
Kebin Fan
2015-01-01
Full Text Available Electromagnetic metamaterials are designer materials made from ‘artificial atoms’ which provide unprecedented control over light matter interactions. Metamaterials are fashioned to yield a specific response to the electric and magnetic components of light and have realized a multitude of exotic properties difficult to achieve with natural materials. Having matured over the last decade and a half, researchers now look toward realizing applications of metamaterials. The ability to dynamically control novel responses exhibited by electromagnetic metamaterials would bolster this quest thus ushering in the next revolution in materials.
Essentials of Computational Electromagnetics
Sheng, Xin-Qing
2012-01-01
Essentials of Computational Electromagnetics provides an in-depth introduction of the three main full-wave numerical methods in computational electromagnetics (CEM); namely, the method of moment (MoM), the finite element method (FEM), and the finite-difference time-domain (FDTD) method. Numerous monographs can be found addressing one of the above three methods. However, few give a broad general overview of essentials embodied in these methods, or were published too early to include recent advances. Furthermore, many existing monographs only present the final numerical results without specifyin
Das, Ashok
2013-01-01
These lecture notes on electromagnetism have evolved from graduate and undergraduate EM theory courses given by the author at the University of Rochester, with the basics presented with clarity and his characteristic attention to detail. The thirteen chapters cover, in logical sequence, topics ranging from electrostatics, magnetostatics and Maxwell's equations to plasmas and radiation. Boundary value problems are treated extensively, as are wave guides, electromagnetic interactions and fields. This second edition comprises many of the topics expanded with more details on the derivation of vari
The theory of electromagnetism
Jones, D S
1964-01-01
The Theory of the Electomagnetism covers the behavior of electromagnetic fields and those parts of applied mathematics necessary to discover this behavior. This book is composed of 11 chapters that emphasize the Maxwell's equations. The first chapter is concerned with the general properties of solutions of Maxwell's equations in matter, which has certain macroscopic properties. The succeeding chapters consider specific problems in electromagnetism, including the determination of the field produced by a variable charge, first in isolation and then in the surface distributions of an antenna. The
Electromagnetic fields and interactions
Becker, Richard
1982-01-01
For more than a century, ""Becker"" and its forerunner, ""Abraham-Becker,"" have served as the bible of electromagnetic theory for countless students. This definitive translation of the physics classic features both volumes of the original text.Volume I, on electromagnetic theory, includes an introduction to vector and tensor calculus, the electrostatic field, electric current and the field, and the theory of relativity. The second volume comprises a self-contained introduction to quantum theory that covers the classical principles of electron theory and quantum mechanics, problems involving
Electromagnetic induction in Australia
Lilley, F. E. M.
Electromagnetic induction at the terrestrial surface is a general and ubiquitous process. This note, which covers research on the subject in Australia, reflects the writer's own interest and refers particularly to induction by natural source fields in the period range of 1 minute to 1 day.Such source fields arise external to Earth, in the ionosphere and beyond, in the magnetosphere. The process of electromagnetic induction by these fields involves the flow through Earth of tens of thousands of amperes, over scale lengths of thousands of kilometers.
Electromagnetic clutches and couplings
Vorob'Yeva, T M; Fry, D W; Higinbotham, W
2013-01-01
Electromagnetic Clutches and Couplings contains a detailed description of U.S.S.R. electromagnetic friction clutches, magnetic couplings, and magnetic particle couplings. This book is divided into four chapters. The first chapter discusses the design and construction of magnetic (solenoid-operated) couplings, which are very quick-acting devices and used in low power high-speed servo-systems. Chapter 2 describes the possible fields of application, design, construction, and utilization of magnetic particle couplings. The aspects of construction, design, and utilization of induction clutches (sli
Electromagnetic interference: a radiant future!
Leferink, Frank Bernardus Johannes
2015-01-01
Although Electromagnetic Interference and Electromagnetic Compatibility are well established domains, the introduction of new technologies results in new challenges. Changes in both measurement techniques, and technological trends resulting in new types of interference are described. These are the S
Electromagnetic interference: a radiant future!
Leferink, Frank Bernardus Johannes
2015-01-01
Although Electromagnetic Interference and Electromagnetic Compatibility are well established domains, the introduction of new technologies results in new challenges. Changes in both measurement techniques, and technological trends resulting in new types of interference are described. These are the
Electromagnetic fields in stratified media
Li, Kai
2009-01-01
Dealing with an important branch of electromagnetic theory with many useful applications in subsurface communication, radar, and geophysical prospecting and diagnostics, this book introduces electromagnetic theory and wave propagation in complex media.
New perspectives on classical electromagnetism
Cote, Paul J.
2009-01-01
The fallacies associated with the gauge concept in electromagnetism are illustrated. A clearer and more valid formulation of the basics of classical electromagnetism is provided by recognizing existing physical constraints as well as the physical reality of the vector potential.
Electromagnetic Force on a Brane
Li, Li-Xin
2016-01-01
A fundamental assumption in the theory of brane world is that all matter and radiation are confined on the four-dimensional brane and only gravitons can propagate in the five-dimensional bulk spacetime. The brane world theory did not provide an explanation for the existence of electromagnetic fields and the origin of the electromagnetic field equation. In this paper, we propose a model for explaining the existence of electromagnetic fields on a brane and deriving the electromagnetic field equation. Similar to the case in Kaluza-Klein theory, we find that electromagnetic fields and the electromagnetic field equation can be derived from the five-dimensional Einstein field equation. However, the derived electromagnetic field equation differs from the Maxwell equation by containing a term with the electromagnetic potential vector coupled to the spacetime curvature tensor. So it can be considered as generalization of the Maxwell equation in a curved spacetime. The gravitational field equation on the brane is also ...
Numerical Simulation of Electromagnetic Force in Double-Sided Arc Welding Process
Hongming GAO; Lin WU; Honggang DONG
2003-01-01
Up till now, most of the researchers believe that there are four kinds of forces in the weld pool convection, they aresurface tension, electromagnetic force, buoyancy and gas shear stress. So electromagnetic force is very important,especially when large c
High-Altitude Electromagnetic Pulse (HEMP) Testing
2015-07-09
Electromagnetic Pulse Horizontal Electromagnetic Pulse Advanced Fast Electromagnetic Pulse Nuclear Weapons Effect Testing and Environments 16. SECURITY...TOP 01-2-620A 9 July 2015 G-1 APPENDIX G. ABBREVIATIONS. AFEMP Advanced Fast Electromagnetic ... Electromagnetic Pulse A burst of electromagnetic radiation from a nuclear explosion or a suddenly fluctuating magnetic field. The resulting electric and
Simple Superconducting "Permanent" Electromagnet
Israelson, Ulf E.; Strayer, Donald M.
1992-01-01
Proposed short tube of high-temperature-superconducting material like YBa2Cu3O7 acts as strong electromagnet that flows as long as magnetic field remains below critical value and temperature of cylinder maintained sufficiently below superconducting-transition temperature. Design exploits maximally anisotropy of high-temperature-superconducting material.
Statistical electromagnetics: Complex cavities
Naus, H.W.L.
2008-01-01
A selection of the literature on the statistical description of electromagnetic fields and complex cavities is concisely reviewed. Some essential concepts, for example, the application of the central limit theorem and the maximum entropy principle, are scrutinized. Implicit assumptions, biased choic
Nanofocusing of electromagnetic radiation
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...
Manifestly covariant electromagnetism
Hillion, P. [Institut Henri Poincare' , Le Vesinet (France)
1999-03-01
The conventional relativistic formulation of electromagnetism is covariant under the full Lorentz group. But relativity requires covariance only under the proper Lorentz group and the authors present here the formalism covariant under the complex rotation group isomorphic to the proper Lorentz group. The authors discuss successively Maxwell's equations, constitutive relations and potential functions. A comparison is made with the usual formulation.
"Hearing" Electromagnetic Waves
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…
"Hearing" Electromagnetic Waves
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…
Equivalence principles and electromagnetism
Ni, W.-T.
1977-01-01
The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.
Computational Electronics and Electromagnetics
DeFord, J.F.
1993-03-01
The Computational Electronics and Electromagnetics thrust area is a focal point for computer modeling activities in electronics and electromagnetics in the Electronics Engineering Department of Lawrence Livermore National Laboratory (LLNL). Traditionally, they have focused their efforts in technical areas of importance to existing and developing LLNL programs, and this continues to form the basis for much of their research. A relatively new and increasingly important emphasis for the thrust area is the formation of partnerships with industry and the application of their simulation technology and expertise to the solution of problems faced by industry. The activities of the thrust area fall into three broad categories: (1) the development of theoretical and computational models of electronic and electromagnetic phenomena, (2) the development of useful and robust software tools based on these models, and (3) the application of these tools to programmatic and industrial problems. In FY-92, they worked on projects in all of the areas outlined above. The object of their work on numerical electromagnetic algorithms continues to be the improvement of time-domain algorithms for electromagnetic simulation on unstructured conforming grids. The thrust area is also investigating various technologies for conforming-grid mesh generation to simplify the application of their advanced field solvers to design problems involving complicated geometries. They are developing a major code suite based on the three-dimensional (3-D), conforming-grid, time-domain code DSI3D. They continue to maintain and distribute the 3-D, finite-difference time-domain (FDTD) code TSAR, which is installed at several dozen university, government, and industry sites.
Childhood Leukemia and Electromagnetic Fields
Alpaslan Türkkan
2009-12-01
Full Text Available In this review, the relationship between very low frequency electromagnetic fields, originating from high voltage powerlines, and childhood leukemia was evaluated. Electromagnetic fields have biological effects. Whole populations are effected by different levels of electromagnetic fields but children are more sensible. In urban areas high voltage powerlines are the main sources of electromagnetic fields. The relation of electromagnetic fields due to high voltage powerlines and leukemia with consideration of dose-response and distance is investigated in several studies. There are different opinions on the effects of electromagnetic fields on general health. The relation between electromagnetic fields and childhood leukemia must be considered separately. Although there is no limit value, it is generally accepted that exposure to 0.4 µT and over doubles the risk of leukemia in children 15 years and younger. (Journal of Current Pediatrics 2009; 7: 137-41
Coherent population trapping (CPT) versus Electromagnetically induced transparency (EIT)
Khan, Sumanta; Chanu, Sapam Ranjita; Bharti, Vineet; Natarajan, Vasant
2015-01-01
We discuss the differences between two well-studied and related phenomena---coherent population trapping (CPT) and electromagnetically induced transparency (EIT). We show experimentally that one does not observe EIT in a Rb vapor cell filled with buffer gas, a kind of cell that is used commonly in CPT experiments because it results in significant linewidth reduction of the resonance.
Comparison of the Recoil of Conventional and Electromagnetic Cannon
Edward M. Schmidt
2001-01-01
Full Text Available The recoil from an electromagnetic (EM railgun is discussed and compared with that from conventional, propellant gas driven cannon. It is shown that, under similar launch conditions, the recoil of the EM gun is less than that of the powder gun; however, use of a muzzle brake on a powder gun can alter this relative behavior.
ELECTROMAGNETIC RELEASE MECHANISM
Michelson, C.
1960-09-13
An electromagnetic release mechanism is offered that may be used, for example, for supporting a safety rod for a nuclear reactor. The release mechanism is designed to have a large excess holding force and a rapid, uniform, and dependable release. The fast release is accomplished by providing the electromagnet with slotttd polts separated by an insulating potting resin, and by constructing the poles with a ferro-nickel alloy. The combination of these two features materially reduces the eddy current power density whenever the magnetic field changes during a release operation. In addition to these features, the design of the armature is such as to provide ready entrance of fluid into any void that might tend to form during release of the armature. This also improves the release time for the mechanism. The large holding force for the mechanism is accomplished by providing a small, selected, uniform air gap between the inner pole piece and the armature.
Classical Electromagnetic Theory
VanderLinde, Jack
2004-01-01
This book is a self contained course in electromagnetic theory suitable for senior physics and electrical engineering students as well as graduate students whose past has not prepared them well for books such as Jackson or Landau and Lifschitz. The text is liberally sprinkled with worked examples illustrating the application of the theory to various physical problems. In this new edition I have endeavored to improve the accuracy and readability, added and further clarified examples, added sections on Schwarz-Christoffel mappings, and to make the book more self sufficient added an appendix on orthogonal function expansions and added the derivation of Bessel functions and Legendre polynomials as well as derivation of their generating functions. The number of student exercises has been increased by 45 over the previous edition. This book stresses the unity of electromagnetic theory with electric and magnetic fields developed in parallel. SI units are used throughout and considerable use is made of tensor notatio...
Electromagnetic fields and waves
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...
The KLOE electromagnetic calorimeter
Adinolfi, M.; Ambrosino, F.; Antonelli, A.; Antonelli, M.; Anulli, F.; Barbiellini, G.; Bencivenni, G.; Bertolucci, S.; Bini, C. E-mail: cesare.bini@roma1.infn.it; Bloise, C.; Bocci, V.; Bossi, F.; Branchini, P.; Cabibbo, G.; Caloi, R.; Campana, P.; Casarsa, M.; Cataldi, G.; Ceradini, F.; Cervelli, F.; Ciambrone, P.; De Lucia, E.; De Simone, P.; De Zorzi, G.; Dell' Agnello, S.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Falco, S.; Doria, A.; Erriquez, O.; Farilla, A.; Ferrari, A.; Ferrer, M.L.; Finocchiaro, G.; Forti, C.; Franceschi, A.; Franzini, P.; Gao, M.L.; Gatti, C.; Gauzzi, P.; Giannasi, A.; Giovannella, S.; Graziani, E.; Han, H.G.; Han, S.W.; Huang, X.; Incagli, M.; Ingrosso, L.; Keeble, L.; Kim, W.; Kuo, C.; Lanfranchi, G.; Lee-Franzini, J.; Lomtadze, T.; Mao, C.S.; Martemianov, M.; Mei, W.; Messi, R.; Miscetti, S.; Moccia, S.; Moulson, M.; Mueller, S.; Murtas, F.; Pacciani, L.; Palomba, M.; Palutan, M.; Pasqualucci, E.; Passalacqua, L.; Passeri, A.; Picca, D.; Pirozzi, G.; Pontecorvo, L.; Primavera, M.; Santangelo, P.; Santovetti, E.; Saracino, G.; Schamberger, R.D.; Sciascia, B.; Scuri, F.; Sfiligoi, I.; Silano, P.; Spadaro, T.; Spiriti, E.; Tortora, L.; Valente, P.; Valeriani, B.; Venanzoni, G.; Ventura, A.; Woelfle, S.; Wu, Y.; Xie, Y.G.; Zema, P.F.; Zhang, C.D.; Zhang, J.Q.; Zhao, P.P
2002-04-11
The KLOE detector was designed primarily for the study of CP violation in neutral kaon decays at DAPHINE, the Frascati phi-factory. The detector consists of a tracker and an electromagnetic calorimeter. A lead-scintillating-fiber sampling calorimeter satisfies best the requirements of the experiment, providing adequate energy resolution and superior timing accuracy. We describe in the following the construction of the calorimeter, its calibration and how the calorimeter information is used to obtain energy, point of entry and time of the arrival of photons, electrons and charged particles. With e{sup +}e{sup -} collision data at DAPHINE for an integrated luminosity of some 2 pb{sup -1} we find for electromagnetic showers, an energy resolution of 5.7%/{radical}E(GeV) and a time resolution of 54/{radical}E(GeV) ps. We also present a measurement of efficiency for low energy photons.
Electromagnetic acoustic imaging.
Emerson, Jane F; Chang, David B; McNaughton, Stuart; Jeong, Jong Seob; Shung, K K; Cerwin, Stephen A
2013-02-01
Electromagnetic acoustic imaging (EMAI) is a new imaging technique that uses long-wavelength RF electromagnetic (EM) waves to induce ultrasound emission. Signal intensity and image contrast have been found to depend on spatially varying electrical conductivity of the medium in addition to conventional acoustic properties. The resultant conductivity- weighted ultrasound data may enhance the diagnostic performance of medical ultrasound in cancer and cardiovascular applications because of the known changes in conductivity of malignancy and blood-filled spaces. EMAI has a potential advantage over other related imaging techniques because it combines the high resolution associated with ultrasound detection with the generation of the ultrasound signals directly related to physiologically important electrical properties of the tissues. Here, we report the theoretical development of EMAI, implementation of a dual-mode EMAI/ultrasound apparatus, and successful demonstrations of EMAI in various phantoms designed to establish feasibility of the approach for eventual medical applications.
Electromagnetic wave energy converter
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.
The KLOE electromagnetic calorimeter
Adinolfi, M; Antonelli, A; Antonelli, M; Anulli, F; Barbiellini, G; Bencivenni, G; Bertolucci, Sergio; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Cabibbo, G; Caloi, R; Campana, P; Casarsa, M; Cataldi, G; Ceradini, F; Cervelli, F; Ciambrone, P; De Lucia, E; De Simone, P; De Zorzi, G; Dell'Agnello, S; Denig, A; Di Domenico, A; Di Donato, C; Di Falco, S; Doria, A; Erriquez, O; Farilla, A; Ferrari, A; Ferrer, M L; Finocchiaro, G; Forti, C; Franceschi, A; Franzini, P; Gao, M L; Gatti, C; Gauzzi, P; Giannasi, A; Giovannella, S; Graziani, E; Han, H G; Han, S W; Huang, X; Incagli, M; Ingrosso, L; Keeble, L; Kim, W; Kuo, C; Lanfranchi, G; Lee-Franzini, J; Lomtadze, T A; Mao Chen Sheng; Martemyanov, M; Mei, W; Messi, R; Miscetti, S; Moccia, S; Moulson, M; Murtas, F; Müller, S; Pacciani, L; Palomba, M; Palutan, M; Pasqualucci, E; Passalacqua, L; Passeri, A; Picca, D; Pirozzi, G; Pontecorvo, L; Primavera, M; Santangelo, P; Santovetti, E; Saracino, G; Schamberger, R D; Sciascia, B; Scuri, F; Sfiligoi, I; Silano, P; Spadaro, T; Spiriti, E; Tortora, L; Valente, P; Valeriani, B; Venanzoni, G; Ventura, A; Wu, Y; Wölfle, S; Xie, Y G; Zema, P F; Zhang, C D; Zhang, J Q; Zhao, P P
2002-01-01
The KLOE detector was designed primarily for the study of CP violation in neutral kaon decays at DAPHINE, the Frascati phi-factory. The detector consists of a tracker and an electromagnetic calorimeter. A lead-scintillating-fiber sampling calorimeter satisfies best the requirements of the experiment, providing adequate energy resolution and superior timing accuracy. We describe in the following the construction of the calorimeter, its calibration and how the calorimeter information is used to obtain energy, point of entry and time of the arrival of photons, electrons and charged particles. With e sup + e sup - collision data at DAPHINE for an integrated luminosity of some 2 pb sup - sup 1 we find for electromagnetic showers, an energy resolution of 5.7%/sq root E(GeV) and a time resolution of 54/sq root E(GeV) ps. We also present a measurement of efficiency for low energy photons.
Gravitation and electromagnetism
Sidharth, B.G. [Birla Science Centre, Adarsh Nagar, Hyderabad (India)
2001-06-01
The realms of gravitation, belonging to classical physics, and of electromagnetism, belonging to the theory of the electron and quantum mechanics have remained apart as two separate pillars, in spite of a century of effort by physicists to reconcile them. In this paper it is argued that if ideas of classical spacetime have been extended to include in addition to non-integrability non-commutavity also, then such a reconciliation is possible.
Fractional Electromagnetic Waves
Gómez, J F; Bernal, J J; Tkach, V I; Guía, M
2011-01-01
In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.
The KLOE electromagnetic calorimeter
Adinolfi, M.; Ambrosino, F.; Antonelli, A.; Antonelli, M.; Anulli, F.; Barbiellini, G.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocci, V.; Bossi, F.; Branchini, P.; Cabibbo, G.; Caloi, R.; Campana, P.; Casarsa, M.; Cataldi, G.; Ceradini, F.; Cervelli, F.; Ciambrone, P.; De Lucia, E.; De Simone, P.; De Zorzi, G.; Dell' Agnello, S.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Falco, S.; Doria, A.; Erriquez, O.; Farilla, A.; Ferrari, A.; Ferrer, M.L.; Finocchiaro, G.; Forti, C.; Franceschi, A.; Franzini, P.; Gao, M.L.; Gatti, C.; Gauzzi, P.; Giannasi, A.; Giovannella, S.; Graziani, E.; Han, H.G.; Han, S.W.; Huang, X.; Incagli, M.; Ingrosso, L.; Keeble, L.; Kim, W.; Kuo, C.; Lanfranchi, G. E-mail: gaia.lanfranchi@lnf.infn.it; Lee-Franzini, J.; Lomtadze, T.; Mao, C.S.; Martemianov, M.; Mei, W.; Messi, R.; Miscetti, S.; Moccia, S.; Moulson, M.; Mueller, S.; Murtas, F.; Pacciani, L.; Palomba, M.; Palutan, M.; Pasqualucci, E.; Passalacqua, L.; Passeri, A.; Picca, D.; Pirozzi, G.; Pontecorvo, L.; Primavera, M.; Santangelo, P.; Santovetti, E.; Saracino, G.; Schamberger, R.D.; Sciascia, B.; Scuri, F.; Sfiligoi, I.; Silano, P.; Spadaro, T.; Spiriti, E.; Tortora, L.; Valente, P.; Valeriani, B.; Venanzoni, G.; Ventura, A.; Woelfle, S.; Wu, Y.; Xie, Y.G.; Zema, P.F.; Zhang, C.D.; Zhang, J.Q.; Zhao, P.P
2002-11-21
The KLOE calorimeter is a fine lead-scintillating fiber sampling calorimeter. We describe in the following the calibration procedures and the calorimeter performances obtained after 3 years of data taking. We get an energy resolution for electromagnetic showers of 5.4%/{radical}E(GeV) and a time resolution of 56 ps/{radical}E(GeV). We also present a measurement of efficiency for low-energy photons.
Dynamic electromagnetic metamaterials
Fan, Kebin; Padilla, Willie J.
2015-01-01
Electromagnetic metamaterials are designer materials made from ‘artificial atoms’ which provide unprecedented control over light matter interactions. Metamaterials are fashioned to yield a specific response to the electric and magnetic components of light and have realized a multitude of exotic properties difficult to achieve with natural materials. Having matured over the last decade and a half, researchers now look toward realizing applications of metamaterials. The ability to dynamically c...
Electromagnetism and interconnections
Charruau, S
2009-01-01
This book covers the theoretical problems of modeling electrical behavior of the interconnections encountered in everyday electronic products. The coverage shows the theoretical tools of waveform prediction at work in the design of a complex and high-speed digital electronic system. Scientists, research engineers, and postgraduate students interested in electromagnetism, microwave theory, electrical engineering, or the development of simulation tools software for high speed electronic system design automation will find this book an illuminating resource.
Introduction to electromagnetic theory
Owen, George E
2003-01-01
A direct, stimulating approach to electromagnetic theory, this text employs matrices and matrix methods for the simple development of broad theorems. The author uses vector representation throughout the book, with numerous applications of Poisson's equation and the Laplace equation (the latter occurring in both electronics and magnetic media). Contents include the electrostatics of point charges, distributions of charge, conductors and dielectrics, currents and circuits, and the Lorentz force and the magnetic field. Additional topics comprise the magnetic field of steady currents, induced ele
Belle electromagnetic calorimeter
Miyabayashi, K
2002-01-01
We report the performance of the Belle electromagnetic calorimeter for the first three years operation. Good mass resolutions for pi sup 0 and eta are obtained to be 4.8 and 12.1 MeV/c sup 2 , respectively. The degradation of light output due to the radiation damage is small, about 3% for the radiation dose of 40 rad. These performances promise further study of B physics with neutral particle reconstruction.
Making electromagnetic wavelets
Kaiser, Gerald [Center for Signals and Waves, 3803 Tonkawa Trail no. 2, Austin, TX 78756-3915 (United States)
2004-06-04
Electromagnetic wavelets are constructed using scalar wavelets as superpotentials, together with an appropriate polarization. It is shown that oblate spheroidal antennas, which are ideal for their production and reception, can be made by deforming and merging two branch cuts. This determines a unique field on the interior of the spheroid which gives the boundary conditions for the surface charge-current density necessary to radiate the wavelets. These sources are computed, including the impulse response of the antenna.
Electromagnetic force on a brane
Li, Li-Xin
2016-11-01
A fundamental assumption in the theory of brane world is that all matter and radiation are confined on the four-dimensional brane and only gravitons can propagate in the five-dimensional bulk spacetime. The brane world theory did not provide an explanation for the existence of electromagnetic fields and the origin of the electromagnetic field equation. In this paper, we propose a model for explaining the existence of electromagnetic fields on a brane and deriving the electromagnetic field equation. Similar to the case in Kaluza–Klein theory, we find that electromagnetic fields and the electromagnetic field equation can be derived from the five-dimensional Einstein field equation. However, the derived electromagnetic field equation differs from the Maxwell equation by containing a term with the electromagnetic potential vector coupled to the spacetime curvature tensor. So it can be considered as generalization of the Maxwell equation in a curved spacetime. The gravitational field equation on the brane is also derived with the stress–energy tensor for electromagnetic fields explicitly included and the Weyl tensor term explicitly expressed with matter fields and their derivatives in the direction of the extra-dimension. The model proposed in the paper can be regarded as unification of electromagnetic and gravitational interactions in the framework of brane world theory.
Coherent hybrid electromagnetic field imaging
Cooke, Bradly J.; Guenther, David C.
2008-08-26
An apparatus and corresponding method for coherent hybrid electromagnetic field imaging of a target, where an energy source is used to generate a propagating electromagnetic beam, an electromagnetic beam splitting means to split the beam into two or more coherently matched beams of about equal amplitude, and where the spatial and temporal self-coherence between each two or more coherently matched beams is preserved. Two or more differential modulation means are employed to modulate each two or more coherently matched beams with a time-varying polarization, frequency, phase, and amplitude signal. An electromagnetic beam combining means is used to coherently combine said two or more coherently matched beams into a coherent electromagnetic beam. One or more electromagnetic beam controlling means are used for collimating, guiding, or focusing the coherent electromagnetic beam. One or more apertures are used for transmitting and receiving the coherent electromagnetic beam to and from the target. A receiver is used that is capable of square-law detection of the coherent electromagnetic beam. A waveform generator is used that is capable of generation and control of time-varying polarization, frequency, phase, or amplitude modulation waveforms and sequences. A means of synchronizing time varying waveform is used between the energy source and the receiver. Finally, a means of displaying the images created by the interaction of the coherent electromagnetic beam with target is employed.
Kuzelev, M. V., E-mail: kuzelev@mail.ru [Moscow State University (Russian Federation)
2011-02-15
A nonlinear theory of interaction of two electromagnetic waves with a beam or a gas of spinless charged particles is developed. The effects of stimulated Compton scattering of electromagnetic waves and stimulated particle pair production (annihilation) during a collision of two electromagnetic quanta are investigated. Other stimulated processes that can occur only in a medium and decelerate electromagnetic waves are also considered. The relation between stimulated processes and various types of instabilities considered in classical electrodynamics of plasmas and plasmalike media is demonstrated.
Cellular Effects of Electromagnetic Radiation.
2014-09-26
8217-- - - .- . - .- ’*-_- - 7 - r - .STUDIES OF EXPOSURE TO AMPLITUDE-MODULATED FIELDS The electromagnetic fields to which naval personnel are exposed tend to...radiation) ,.- Biological effects of electromagnetic fields , 20. ABSTRACT (Contimee an revers side II neceesmv aiId identify by Wek numbe") , .P-Giant...cells of characean algae were examined for electrophysiological sequelae to acute electromagnetic field irradiation at 10 mW/cm Carrier frequencies
Electromagnetic field and cosmic censorship
Düztaş, Koray
2013-01-01
We construct a gedanken experiment in which an extremal Kerr black hole interacts with a test electromagnetic field. Using Teukolsky's solutions for electromagnetic perturbations in Kerr spacetime, and the conservation laws imposed by the energy momentum tensor of the electromagnetic field and the Killing vectors of the spacetime, we prove that this interaction cannot convert the black hole into a naked singularity, thus cosmic censorship conjecture is not violated in this case.
Electromagnetic fields in biological systems
Lin, James C
2012-01-01
"Focusing on exposure, induced fields, and absorbed energy, this volume covers the interaction of electromagnetic fields and waves with biological systems, spanning static fields to terahertz waves...
Battlefield Electromagnetic Environments Office (BEEO)
Federal Laboratory Consortium — The Battlefield Electromagnetic Environments Office (BEEO) develops, maintains, and operates the Army Materiel Command (AMC) databases for spectrum management, per...
Method of moments in electromagnetics
Gibson, Walton C
2007-01-01
Responding to the need for a clear, up-to-date introduction to the field, The Method of Moments in Electromagnetics explores surface integral equations in electromagnetics and presents their numerical solution using the method of moments (MOM) technique. It provides the numerical implementation aspects at a nuts-and-bolts level while discussing integral equations and electromagnetic theory at a higher level. The author covers a range of topics in this area, from the initial underpinnings of the MOM to its current applications. He first reviews the frequency-domain electromagnetic theory and t
Electromagnetic waves in stratified media
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
Electromagnetically induced transparency in an entangled medium
Li, Weibin; Hofferberth, Sebastian; Lesanovsky, Igor
2014-01-01
We theoretically investigate light propagation and electromagnetically induced transparency (EIT) in a quasi one-dimensional gas in which atoms interact strongly via exchange interactions. We focus on the case in which the gas is initially prepared in a many-body state that contains a single excitation and conduct a detailed study of the absorptive and dispersive properties of such a medium. This scenario is achieved in interacting gases of Rydberg atoms with two relevant $S$-states that are coupled through exchange. Of particular interest is the case in which the medium is prepared in an entangled spinwave state. This, in conjunction with the exchange interaction, gives rise to a non-local susceptibilty which --- in comparison to conventional Rydberg EIT --- qualitatively alters the absorption and propagation of weak probe light, leading to non-local propagation and enhanced absorption.
Electromagnetism from counting
Noyes, H.P.
1992-12-01
The fact that experimental accuracy is finite makes the measurement of particle positions and velocities non-local and often non- commutative even in a scale invariant theory. Applied to electromagnetic and gravitational phenomena, we argue that this leads to a relativistic action at a distance theory in which fields'' are simple a quasi-local interpolating concept extrapolated from macroscopic conservation laws. We sketch how this analysis could lead to classical field equations as a macroscopic approximation to relativistic quantum mechanics, but do not construct a formal proof.
Electromagnetism from counting
Noyes, H.P.
1992-12-01
The fact that experimental accuracy is finite makes the measurement of particle positions and velocities non-local and often non- commutative even in a scale invariant theory. Applied to electromagnetic and gravitational phenomena, we argue that this leads to a relativistic action at a distance theory in which ``fields`` are simple a quasi-local interpolating concept extrapolated from macroscopic conservation laws. We sketch how this analysis could lead to classical field equations as a macroscopic approximation to relativistic quantum mechanics, but do not construct a formal proof.
Introduction to electromagnetic engineering
Harrington, Roger E
2003-01-01
This study of electromagnetic theory introduces students to a broad range of quantities and concepts, imparting the necessary vector analysis and associated mathematics and reinforcing its teachings with several elementary field problems. Based on circuit theory rather than on the classical force-relationship approach, the text uses the theory of electric circuits to provide a system of experiments already familiar to the electrical engineer; a series of field concepts are then introduced as a logical extension of circuit theory. Virtually unobtainable elsewhere, this text was written by a pr
Visinelli, Luca
2014-01-01
We extend the duality symmetry between the electric and the magnetic fields to the case in which an additional axion-like term is present, and we derive the set of Maxwell's equations that preserves this symmetry. This new set of equations allows for a gauge symmetry extending the ordinary symmetry in the classical electrodynamics. We obtain explicit solutions for the new set of equations in the absence of external sources, and we discuss the implications of a new internal symmetry between the axion field and the electromagnetic gauge potential.
Handbook of electromagnetic compatibility
1995-01-01
This""know-how""book gives readers a concise understanding of the fundamentals of EMC, from basic mathematical and physical concepts through present, computer-age methods used in analysis, design, and tests. With contributions from leading experts in their fields, the text provides a comprehensive overview. Fortified with information on how to solve potential electromagnetic interference (EMI) problems that may arise in electronic design, practitioners will be betterable to grasp the latest techniques, trends, and applications of this increasingly important engineering discipline.Handbook of E
Electromagnetic Field Penetration Studies
Deshpande, M.D.
2000-01-01
A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.
Metamaterials beyond electromagnetism.
Kadic, Muamer; Bückmann, Tiemo; Schittny, Robert; Wegener, Martin
2013-12-01
Metamaterials are rationally designed man-made structures composed of functional building blocks that are densely packed into an effective (crystalline) material. While metamaterials are mostly associated with negative refractive indices and invisibility cloaking in electromagnetism or optics, the deceptively simple metamaterial concept also applies to rather different areas such as thermodynamics, classical mechanics (including elastostatics, acoustics, fluid dynamics and elastodynamics), and, in principle, also to quantum mechanics. We review the basic concepts, analogies and differences to electromagnetism, and give an overview on the current state of the art regarding theory and experiment-all from the viewpoint of an experimentalist. This review includes homogeneous metamaterials as well as intentionally inhomogeneous metamaterial architectures designed by coordinate-transformation-based approaches analogous to transformation optics. Examples are laminates, transient thermal cloaks, thermal concentrators and inverters, 'space-coiling' metamaterials, anisotropic acoustic metamaterials, acoustic free-space and carpet cloaks, cloaks for gravitational surface waves, auxetic mechanical metamaterials, pentamode metamaterials ('meta-liquids'), mechanical metamaterials with negative dynamic mass density, negative dynamic bulk modulus, or negative phase velocity, seismic metamaterials, cloaks for flexural waves in thin plates and three-dimensional elastostatic cloaks.
Electromagnetically Induced Entanglement.
Yang, Xihua; Xiao, Min
2015-08-28
Quantum entanglement provides an essential resource for quantum computation, quantum communication, and quantum network. How to conveniently and efficiently produce entanglement between bright light beams presents a challenging task to build realistic quantum information processing networks. Here, we present an efficient and convenient way to realize a novel quantum phenomenon, named electromagnetically induced entanglement, in the conventional Λ-type three-level atomic system driven by a strong pump field and a relatively weak probe field. Nearly perfect entanglement between the two fields can be achieved with a low coherence decay rate between the two lower levels, high pump-field intensity, and large optical depth of the atomic ensemble. The physical origin is quantum coherence between the lower doublet produced by the pump and probe fields, similar to the well-known electromagnetically induced transparency. This method would greatly facilitate the generation of nondegenerate narrow-band continuous-variable entanglement between bright light beams by using only coherent laser fields, and may find potential and broad applications in realistic quantum information processing.
The HPS electromagnetic calorimeter
Balossino, I.; Baltzell, N.; Battaglieri, M.; Bondì, M.; Buchanan, E.; Calvo, D.; Celentano, A.; Charles, G.; Colaneri, L.; D'Angelo, A.; Napoli, M. De; Vita, R. De; Dupré, R.; Egiyan, H.; Ehrhart, M.; Filippi, A.; Garçon, M.; Gevorgyan, N.; Girod, F.-X.; Guidal, M.; Holtrop, M.; Iurasov, V.; Kubarovsky, V.; Livingston, K.; McCarty, K.; McCormick, J.; McKinnon, B.; Osipenko, M.; Paremuzyan, R.; Randazzo, N.; Rauly, E.; Raydo, B.; Rindel, E.; Rizzo, A.; Rosier, P.; Sipala, V.; Stepanyan, S.; Szumila-Vance, H.; Weinstein, L. B.
2017-05-01
The Heavy Photon Search experiment (HPS) is searching for a new gauge boson, the so-called ;heavy photon.; Through its kinetic mixing with the Standard Model photon, this particle could decay into an electron-positron pair. It would then be detectable as a narrow peak in the invariant mass spectrum of such pairs, or, depending on its lifetime, by a decay downstream of the production target. The HPS experiment is installed in Hall-B of Jefferson Lab. This article presents the design and performance of one of the two detectors of the experiment, the electromagnetic calorimeter, during the runs performed in 2015-2016. The calorimeter's main purpose is to provide a fast trigger and reduce the copious background from electromagnetic processes through matching with a tracking detector. The detector is a homogeneous calorimeter, made of 442 lead-tungstate (PbWO4) scintillating crystals, each read out by an avalanche photodiode coupled to a custom trans-impedance amplifier.
Electromagnetic interaction of metamaterials
Canales, Peter R.
The observation of extraordinary transmission through subwavelength apertures has propelled a great interest in understanding its nature. It defies classical theories of electromagnetic interaction by demanding a closer examination of the surface properties. Traditionally, as surface features become much smaller in size than a single wavelength of interest, the structure is essentially continuous. Any periodic subwavelength corrugation or aperture array should not interact strongly with an incident field and therefore not contribute to any significant transmission through the film. We find that this is not always the case and that we may tune the surface geometry at these scales to affect the overall medium behavior. It is possible that a material may transcend its own natural properties and, in essence, become a metamaterial. The following analysis examines the concepts of metamaterials from a fundamental viewpoint. It does not seek to disrupt classical theories but instead demonstrates their validity to describe a new phenomenon. Several theories have been proposed that offer unique surface interactions as evidence of enhanced transmission. It is proposed that a fundamental Maxwell representation is sufficient in predicting the interaction of an electromagnetic wave with a metamaterial. In particular, a formalism has been developed to analyze enhanced transmission through a metallic grating structure. To experimentally validate this model, a fabrication procedure has been developed that allows for the production of quality thick film structures with subwavelength features. Finally, the analysis of metamaterials looks towards the RF spectrum to demonstrate a novel design to achieve conformal waveguides and antennas.
The HPS electromagnetic calorimeter
Balossino, Ilaria; Battaglieri, Marco; Bondi, Mariangela; Buchanan, Emma; Calvo, Daniela; Celentano, Andrea; Charles, Gabriel; Colaneri, Luca; D'Angelo, Annalisa; De Napoli, Marzio; De Vita, Raffaella; Dupre, Raphael; Ehrhart, Mathieu; Filippi, Alessandra; Garcon, Michel; Girod, Francois-Xavier; Guidal, Michel; Holtrop, Maurik; Iurasov, Volodymyr; Kubarovsky, Valery; McCarty, Kyle; McCormick, Jeremy; Osipenko, Mikhail; Paremuzyan, Rafayel; Randazzo, Nunzio; Rauly, Emmanuel; Raydo, Benjamin; Rindel, Emmanuel; Rizzo, Alessandro; Rosier, Philippe; Sipala, Valeria; Stepanyan, Stepan; Szumila-Vance, Holly; Weinstein, Lawrence
2016-01-01
The Heavy Photon Search experiment (HPS) is searching for a new gauge boson, the so-called "heavy photon". Through its kinetic mixing with the Standard Model photon, this particle could decay into an electron-positron pair. It would then be detectable as a narrow peak in the invariant mass spectrum of such pairs, or, depending on its lifetime, by a decay downstream of the production target. The HPS experiment is installed in Hall-B of Jefferson Lab. This article presents the design and performance of one of the two detectors of the experiment, the electromagnetic calorimeter, during the runs performed in 2015-2016. The calorimeter's main purpose is to provide a fast trigger and reduce the copious background from electromagnetic processes through matching with a tracking detector. The detector is a homogeneous calorimeter, made of 442 lead-tungsten (PbWO$_4$) scintillating crystals, each read-out by an avalanche photodiode coupled to a custom trans-impedance amplifier.
Arrayás, M.; Bouwmeester, D.; Trueba, J. L.
2017-01-01
Maxwell equations in vacuum allow for solutions with a non-trivial topology in the electric and magnetic field line configurations at any given moment in time. One example is a space filling congruence of electric and magnetic field lines forming circles lying on the surfaces of nested tori. In this example the electric, magnetic and Poynting vector fields are orthogonal everywhere. As time evolves the electric and magnetic fields expand and deform without changing the topology and energy, while the Poynting vector structure remains unchanged while propagating with the speed of light. The topology is characterized by the concept of helicity of the field configuration. Helicity is an important fundamental concept and for massless fields it is a conserved quantity under conformal transformations. We will review several methods by which linked and knotted electromagnetic (spin-1) fields can be derived. A first method, introduced by A. Rañada, uses the formulation of the Maxwell equations in terms of differential forms combined with the Hopf map from the three-sphere S3 to the two-sphere S2. A second method is based on spinor and twistor theory developed by R. Penrose in which elementary twistor functions correspond to the family of electromagnetic torus knots. A third method uses the Bateman construction of generating null solutions from complex Euler potentials. And a fourth method uses special conformal transformations, in particular conformal inversion, to generate new linked and knotted field configurations from existing ones. This fourth method is often accompanied by shifting singularities in the field to complex space-time points. Of course the various methods must be closely related to one another although they have been developed largely independently and they suggest different directions in which to expand the study of topologically non-trivial field configurations. It will be shown how the twistor formulation allows for a direct extension to massless
Electromagnetic actuation in MEMS switches
Oliveira Hansen, Roana Melina de; Mátéfi-Tempfli, Mária; Chemnitz, Steffen
. Electromagnetic actuation is a very promising approach to operate such MEMS and Power MEMS devices, due to the long range, reproducible and strong forces generated by this method, among other advantages. However, the use of electromagnetic actuation in such devices requires the use of thick magnetic films, which...
Electromagnetic compatibility in power electronics
Costa , François; Revol , Bertrand
2014-01-01
Scientists largely attribute the recent deterioration of the electromagnetic environment to power electronics. This realization has spurred the study of methodical approaches to electromagnetic compatibility designs as explored in this text. The book addresses major challenges, such as handling numerous parameters vital to predicting electro magnetic effects and achieving compliance with line-harmonics norms, while proposing potential solutions.
Gravitational scattering of electromagnetic radiation
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.
Hybrid synchronous motor electromagnetic torque research
Suvorkova Elena E.
2014-01-01
Full Text Available Electromagnetic field distribution models in reluctance and permanent magnet parts were made by means of Elcut. Dependences of electromagnetic torque on torque angle were obtained.
Electromagnetic Interference (EMI) and TEMPEST Test Facility
Federal Laboratory Consortium — Electromagnetic Interference (EMI), Electromagnetic Compatibility (EMC) and TEMPEST testing are conducted at EPG's Blacktail Canyon Test Facility in one of its two...
Electromagnetic fields and life
Presman, A S
1970-01-01
A broad region of the electromagnetic spectrum long assumed to have no influence on living systems under natural conditions has been critically re-examined over the past decade. This spectral region extends from the superhigh radio frequencies, through de creasing frequencies, to and including essentially static electric and magnetic fields. The author of this monograph, A. S. Presman, has reviewed not only the extensive Russian literatur!;"l, but also all most equally comprehensively the non-Russian literature, dealing with biological influences of these fields. Treated also is literature shedding some light on possible theoretical foundations for these phenomena. A substantial, rapidly increasing number of studies in many laboratories and countries has now clearly established bio logical influences which are independent of the theoretically predictable, simple thermal effects. Indeed many of the effects are produced by field strengths very close to those within the natural environment. The author has,...
Solved problems in electromagnetics
Salazar Bloise, Félix; Bayón Rojo, Ana; Gascón Latasa, Francisco
2017-01-01
This book presents the fundamental concepts of electromagnetism through problems with a brief theoretical introduction at the beginning of each chapter. The present book has a strong didactic character. It explains all the mathematical steps and the theoretical concepts connected with the development of the problem. It guides the reader to understand the employed procedures to learn to solve the exercises independently. The exercises are structured in a similar way: The chapters begin with easy problems increasing progressively in the level of difficulty. This book is written for students of physics and engineering in the framework of the new European Plans of Study for Bachelor and Master and also for tutors and lecturers. .
On steady electromagnetic equilibria
Lehnert, B.
1986-12-01
The existence of steady electromagnetic equilibrium states predicted by an extended Lorentz invariant formulation of Maxwell's equations is analyzed. General equilibrium solutions are outlined which lead to integrated field quantities of the system, such as total charge qo, magnetic moment Mo, mass mo and angular momentum so. The quantization of moMo/qo in terms of Bohr magnetons is shown to be equivalent to the proposed resonance condition of circulating self-confined radiation. Exact equilibrium solutions were deduced in two simple cases, thereby leading to a so of the same order as that of the electron, and to a qo one order of magnitude larger than the electronic charge. A variational procedure is suggested in search for states of minimum charge, under the subsidiary quantum conditions on moMo/qo and so, i.e., by varying the profile of the electric space charge distribution.
Focusing of electromagnetic waves
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.
Electromagnetically Clean Solar Arrays
Stem, Theodore G.; Kenniston, Anthony E.
2008-01-01
The term 'electromagnetically clean solar array' ('EMCSA') refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interferences to and from other nearby electrical and electronic equipment and (2) can be manufactured at lower cost. The reduction of electromagnetic interferences is effected through a combination of (1) electrically conductive, electrically grounded shielding and (2) reduction of areas of current loops (in order to reduce magnetic moments). The reduction of cost is effected by designing the array to be fabricated as a more nearly unitary structure, using fewer components and fewer process steps. Although EMCSAs were conceived primarily for use on spacecraft they are also potentially advantageous for terrestrial applications in which there are requirements to limit electromagnetic interference. In a conventional solar panel of the type meant to be supplanted by an EMCSA panel, the wiring is normally located on the back side, separated from the cells, thereby giving rise to current loops having significant areas and, consequently, significant magnetic moments. Current-loop geometries are chosen in an effort to balance opposing magnetic moments to limit far-0field magnetic interactions, but the relatively large distances separating current loops makes full cancellation of magnetic fields problematic. The panel is assembled from bare photovoltaic cells by means of multiple sensitive process steps that contribute significantly to cost, especially if electomagnetic cleanliness is desired. The steps include applying a cover glass and electrical-interconnect-cell (CIC) sub-assemble, connecting the CIC subassemblies into strings of series-connected cells, laying down and adhesively bonding the strings onto a panel structure that has been made in a separate multi-step process, and mounting the
Electromagnetic Gyrokinetic Simulations
Wan, W
2003-11-19
A new electromagnetic kinetic electron {delta} particle simulation model has been demonstrated to work well at large values of plasma {beta} times the ion-to-electron mass ratio. The simulation is three-dimensional using toroidal flux-tube geometry and includes electron-ion collisions. The model shows accurate shear Alfven wave damping and microtearing physics. Zonal flows with kinetic electrons are found to be turbulent with the spectrum peaking at zero and having a width in the frequency range of the driving turbulence. This is in contrast with adiabatic electron cases where the zonal flows are near stationary, even though the linear behavior of the zonal flow is not significantly affected by kinetic electrons. zonal fields are found to be very weak, consistent with theoretical predictions for {beta} below the kinetic ballooning limit. Detailed spectral analysis of the turbulence data is presented in the various limits.
Discrete Classical Electromagnetic Fields
De Souza, M M
1997-01-01
The classical electromagnetic field of a spinless point electron is described in a formalism with extended causality by discrete finite transverse point-vector fields with discrete and localized point interactions. These fields are taken as a classical representation of photons, ``classical photons". They are all transversal photons; there are no scalar nor longitudinal photons as these are definitely eliminated by the gauge condition. The angular distribution of emitted photons coincides with the directions of maximum emission in the standard formalism. The Maxwell formalism and its standard field are retrieved by the replacement of these discrete fields by their space-time averages, and in this process scalar and longitudinal photons are necessarily created and added. Divergences and singularities are by-products of this averaging process. This formalism enlighten the meaning and the origin of the non-physical photons, the ones that violate the Lorentz condition in manifestly covariant quantization methods.
Nucleon Electromagnetic Form Factors
Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi
2007-10-01
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.
Reasearch and Evaluation of Electromagnetic Fields of Refrigerators
Pranas Baltrėnas
2013-12-01
Full Text Available The use of refrigerators causes the occurence of electromagnetic fields that are invisible and intangible, which therefore makes difficulties in protecting ourselves from them. A refrigerator is an irreplaceable item in domestic household and thus can be hardly ignored by a modern way of human life. In order to preserve the characteristics of products, the refrigerator must operate continuously (24 hrs a day, regardless of the time of the year. This results in a huge increase in electricity consumption, which leads to energy consumption related pollution of the environment emitting CO2 gas. On these grounds, it is necessary to assess electromagnetic fields created by the refrigerator. Studies on electromagnetic fields produced by refrigerators were conducted in domestic premises where people spent a significant part of the day. For comparison purposes, five different power refrigerators were chosen (1 – 0.20 kW; 2 – 0.25 kW; 3 – 0.30 kW; 4 – 0.35 kW; 5 – 0.40 kW. The obtained results, according to the parameters of their electromagnetic fields, were presented in graphs and charts and showed that the values of electric and magnetic intensity of refrigerators depended on the distance and the power of the refrigerator. The conducted research also disclosed that none of tested refrigerators exceeded the permissible limits of electromagnetic fields.Article in Lithuanian
Yang Juan; Wang Yu-Quan; Ma Yan-Jie; Li Peng-Fei; Yang Le; Wang Yang; He Guo-Qiang
2013-01-01
A microwave thruster system that can convert microwave power directly to thrust without a gas propellant is developed.In the system,a cylindrical tapered resonance cavity and a magnetron microwave source are used respectively as the thruster cavity and the energy source to generate the electromagnetic wave.The wave is radiated into and then reflected from the cavity to form a pure standing wave with non-uniform electromagnetic pressure distribution.Consequently,a net electromagnetic thrust exerted on the axis of the thruster cavity appears,which is demonstrated through theoretical calculation based on the electromagnetic theory.The net electromagnetic thrust is also experimentally measured in the range from 70 mN to 720 mN when the microwave output power is from 80 W to 2500 W.
Electromagnetic foundations of electrical engineering
Faria, J A Brandao
2008-01-01
The applications of electromagnetic phenomena within electrical engineering have been evolving and progressing at a fast pace. In contrast, the underlying principles have been stable for a long time and are not expected to undergo any changes. It is these electromagnetic field fundamentals that are the subject of discussion in this book with an emphasis on basic principles, concepts and governing laws that apply across the electrical engineering discipline. Electromagnetic Foundations of Electrical Engineering begins with an explanation of Maxwell's equations, from which the fundament
Electromagnetic transients in power cables
da Silva, Filipe Faria
2013-01-01
From the more basic concepts to the most advanced ones where long and laborious simulation models are required, Electromagnetic Transients in Power Cables provides a thorough insight into the study of electromagnetic transients and underground power cables. Explanations and demonstrations of different electromagnetic transient phenomena are provided, from simple lumped-parameter circuits to complex cable-based high voltage networks, as well as instructions on how to model the cables.Supported throughout by illustrations, circuit diagrams and simulation results, each chapter contains exercises,
Biological effects of electromagnetic fields.
Macrì, M. A.; Di Luzio, Sr.; Di Luzio, S.
2002-01-01
Nowadays, concerns about hazards from electromagnetic fields represent an alarming source for human lives in technologically developed countries. We are surrounded by electromagnetic fields everywhere we spend our working hours, rest or recreational activities. The aim of this review is to summarize the biological effects due to these fields arising from power and transmission lines, electrical cable splices, electronic devices inside our homes and work-places, distribution networks and associated devices such as cellular telephones and wireless communication tower, etc. Special care has been reserved to study the biological effects of electromagnetic fields on cell lines of the mammalian immune system about which our research group has been working for several years.
Differential forms on electromagnetic networks
Balasubramanian, N V; Sen Gupta, D P
2013-01-01
Differential Forms on Electromagnetic Networks deals with the use of combinatorial techniques in electrical circuit, machine analysis, and the relationship between circuit quantities and electromagnetic fields. The monograph is also an introduction to the organization of field equations by the methods of differential forms. The book covers topics such as algebraic structural relations in an electric circuit; mesh and node-pair analysis; exterior differential structures; generalized Stoke's theorem and tensor analysis; and Maxwell's electromagnetic equation. Also covered in the book are the app
A primer on electromagnetic fields
Frezza, Fabrizio
2015-01-01
This book is a concise introduction to electromagnetics and electromagnetic fields that covers the aspects of most significance for engineering applications by means of a rigorous, analytical treatment. After an introduction to equations and basic theorems, topics of fundamental theoretical and applicative importance, including plane waves, transmission lines, waveguides, and Green's functions, are discussed in a deliberately general way. Care has been taken to ensure that the text is readily accessible and self-consistent, with conservation of the intermediate steps in the analytical derivations. The book offers the reader a clear, succinct course in basic electromagnetic theory. It will also be a useful lookup tool for students and designers.
Effect of sample radius on stability of electromagnetic levitation melting
马伟增; 郑红星; 季诚昌; 李建国
2004-01-01
Based on the power dissipating model of spherical sample in free convection gas medium and the expression of input power, the model of temperature calculation for electromagnetic levitation melting sample was established. Considering the limitation of levitation force and levitation sample temperature,the principle of stability levitation zone computation was determined. A spherical sample (ThDy)Fe2 under the protection of argon gas was examined, and the effect of radius of levitation sample and perturbation on the stable levitation zone was investigated.The results show that longitudinal perturbation and transverse perturbation can shorten the length of stable levitation zone and the range of levitation sample radius. By increasing the sample radius and weakening the perturbation the electromagnetic levitation melting stability of sample can be improved.
Gallilei covariant quantum mechanics in electromagnetic fields
H. E. Wilhelm
1985-01-01
Full Text Available A formulation of the quantum mechanics of charged particles in time-dependent electromagnetic fields is presented, in which both the Schroedinger equation and wave equations for the electromagnetic potentials are Galilei covariant, it is shown that the Galilean relativity principle leads to the introduction of the electromagnetic substratum in which the matter and electromagnetic waves propagate. The electromagnetic substratum effects are quantitatively significant for quantum mechanics in reference frames, in which the substratum velocity w is in magnitude comparable with the velocity of light c. The electromagnetic substratum velocity w occurs explicitly in the wave equations for the electromagnetic potentials but not in the Schroedinger equation.
Flow imaging method of electromagnetic measurement in well logging
2008-01-01
Multiphase flow in an oil well is a dynamic phenomenon of inhomogeneous medium,which should be studied in a nonlinear way. This paper presents an electromagnetic measurement method based on the electrical property differences between oil,gas and water to scan,inverse and show the distribution and condition of multiphase flow. Both numerical simulation and physical experiments have proved that clear images could be obtained by this way.
An Electromagnetic Interference Problem via the Mains Distribution Networks
BUZDUGAN, M. I.
2007-11-01
Full Text Available The paper presents an electromagnetic interference problem, due to the proximity of two radio broadcasting stations which injected especially common mode conducted emissions over the maximal limits specified by the national regulations in the public low voltage mains network. These emissions determined the malfunction of the gas heating centrals Themaclassic Saunier Duval installed in the area. The problem was solved by the retro fitting of an extra EMI filter for the mains network, as presented in the paper.
Positron extraction to an electromagnetic field free region
Cooke, D A; Vergani, S; Brown, B; Rubbia, A; Crivelli, P
2015-01-01
We describe a scheme for high efficiency (about 90%) extraction of 50 ns positron bunches from a buffer gas trap in an electromagnetic field free region. The positrons are time bunched to approximately 1 ns (FWHM) and focussed to less than 1 mm ({\\sigma}). The target is kept at ground potential which is an advantage for many applications. The results compare well with SIMION simulations.
Electromagnetic Launching for Affordable Agile Access to Space
2006-04-15
Jan 1993. [13] R. J. Kaye: "Operational Requirements and Issues for Coilgun Electromagnetic Launchers." IEEE Transactions on Magnetics, Vol. 41, No...are often inadequate for use in shock-boundary layer interactions. Because of these issues , the numerical simulation has problems capturing the...and density of the gas) the heating of the projectile upon exit of the launcher into the dense ground-level atmosphere is an issue that must be
Electromagnetic field theories for engineering
Salam, Md Abdus
2014-01-01
A four year Electrical and Electronic engineering curriculum normally contains two modules of electromagnetic field theories during the first two years. However, some curricula do not have enough slots to accommodate the two modules. This book, Electromagnetic Field Theories, is designed for Electrical and Electronic engineering undergraduate students to provide fundamental knowledge of electromagnetic fields and waves in a structured manner. A comprehensive fundamental knowledge of electric and magnetic fields is required to understand the working principles of generators, motors and transformers. This knowledge is also necessary to analyze transmission lines, substations, insulator flashover mechanism, transient phenomena, etc. Recently, academics and researches are working for sending electrical power to a remote area by designing a suitable antenna. In this case, the knowledge of electromagnetic fields is considered as important tool.
Wave propagation in electromagnetic media
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...
Earthquake prediction with electromagnetic phenomena
Hayakawa, Masashi, E-mail: hayakawa@hi-seismo-em.jp [Hayakawa Institute of Seismo Electomagnetics, Co. Ltd., University of Electro-Communications (UEC) Incubation Center, 1-5-1 Chofugaoka, Chofu Tokyo, 182-8585 (Japan); Advanced Wireless & Communications Research Center, UEC, Chofu Tokyo (Japan); Earthquake Analysis Laboratory, Information Systems Inc., 4-8-15, Minami-aoyama, Minato-ku, Tokyo, 107-0062 (Japan); Fuji Security Systems. Co. Ltd., Iwato-cho 1, Shinjyuku-ku, Tokyo (Japan)
2016-02-01
Short-term earthquake (EQ) prediction is defined as prospective prediction with the time scale of about one week, which is considered to be one of the most important and urgent topics for the human beings. If this short-term prediction is realized, casualty will be drastically reduced. Unlike the conventional seismic measurement, we proposed the use of electromagnetic phenomena as precursors to EQs in the prediction, and an extensive amount of progress has been achieved in the field of seismo-electromagnetics during the last two decades. This paper deals with the review on this short-term EQ prediction, including the impossibility myth of EQs prediction by seismometers, the reason why we are interested in electromagnetics, the history of seismo-electromagnetics, the ionospheric perturbation as the most promising candidate of EQ prediction, then the future of EQ predictology from two standpoints of a practical science and a pure science, and finally a brief summary.
Electromagnetic identification of dielectric materials
A. F. Yanenko
2010-05-01
Full Text Available The electromagnetic features and parameters of dielectric materials, which are used in light industry and stomatology. The results of measuring are analyzed and the method of authentication is offered.
Electromagnetic Signals from Bacterial DNA
Widom, A; Srivastava, Y N; Sivasubramanian, S
2011-01-01
Chemical reactions can be induced at a distance due to the propagation of electromagnetic signals during intermediate chemical stages. Although is is well known at optical frequencies, e.g. photosynthetic reactions, electromagnetic signals hold true for muck lower frequencies. In E. coli bacteria such electromagnetic signals can be generated by electric transitions between energy levels describing electrons moving around DNA loops. The electromagnetic signals between different bacteria within a community is a "wireless" version of intercellular communication found in bacterial communities connected by "nanowires". The wireless broadcasts can in principle be of both the AM and FM variety due to the magnetic flux periodicity in electron energy spectra in bacterial DNA orbital motions.
Monte Carlo methods for electromagnetics
Sadiku, Matthew NO
2009-01-01
Until now, novices had to painstakingly dig through the literature to discover how to use Monte Carlo techniques for solving electromagnetic problems. Written by one of the foremost researchers in the field, Monte Carlo Methods for Electromagnetics provides a solid understanding of these methods and their applications in electromagnetic computation. Including much of his own work, the author brings together essential information from several different publications.Using a simple, clear writing style, the author begins with a historical background and review of electromagnetic theory. After addressing probability and statistics, he introduces the finite difference method as well as the fixed and floating random walk Monte Carlo methods. The text then applies the Exodus method to Laplace's and Poisson's equations and presents Monte Carlo techniques for handing Neumann problems. It also deals with whole field computation using the Markov chain, applies Monte Carlo methods to time-varying diffusion problems, and ...
Classical electromagnetism in a nutshell
Garg, Anupam
2012-01-01
This graduate-level physics textbook provides a comprehensive treatment of the basic principles and phenomena of classical electromagnetism. While many electromagnetism texts use the subject to teach mathematical methods of physics, here the emphasis is on the physical ideas themselves. Anupam Garg distinguishes between electromagnetism in vacuum and that in material media, stressing that the core physical questions are different for each. In vacuum, the focus is on the fundamental content of electromagnetic laws, symmetries, conservation laws, and the implications for phenomena such as radiation and light. In material media, the focus is on understanding the response of the media to imposed fields, the attendant constitutive relations, and the phenomena encountered in different types of media such as dielectrics, ferromagnets, and conductors. The text includes applications to many topical subjects, such as magnetic levitation, plasmas, laser beams, and synchrotrons.
Conical electromagnetic radiation flux concentrator
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.
Multiforms, dyadics, and electromagnetic media
Lindell, Ismo V
2015-01-01
This book applies the four-dimensional formalism with an extended toolbox of operation rules, allowing readers to define more general classes of electromagnetic media and to analyze EM waves that can exist in them. End-of-chapter exercises. Formalism allows readers to find novel classes of media. Covers various properties of electromagnetic media in terms of which they can be set in different classes.
Canonical quantization of macroscopic electromagnetism
Philbin, T G, E-mail: tgp3@st-andrews.ac.u [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)
2010-12-15
Application of the standard canonical quantization rules of quantum field theory to macroscopic electromagnetism has encountered obstacles due to material dispersion and absorption. This has led to a phenomenological approach to macroscopic quantum electrodynamics where no canonical formulation is attempted. In this paper macroscopic electromagnetism is canonically quantized. The results apply to any linear, inhomogeneous, magnetodielectric medium with dielectric functions that obey the Kramers-Kronig relations. The prescriptions of the phenomenological approach are derived from the canonical theory.
New Perspective on Classical Electromagnetism
2013-04-01
R. Feynman , R. Leighton, and M. Sands, The Feynman Lectures in Physics vol II (Addison-Wesley, Reading, MA, 1964). 6. W.K.H. Panofsky and M...of the basics of classical electromagnetism is provided by recognizing a previously overlooked law of induction as well as the physical reality of the...classical electromagnetism is provided by recognizing a previously overlooked law of induction as well as the physical reality of the vector potential
Black Hole Thermodynamics and Electromagnetism
Sidharth, B G
2005-01-01
We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.
Canonical quantization of macroscopic electromagnetism
Philbin, T G
2010-01-01
Application of the standard canonical quantization rules of quantum field theory to macroscopic electromagnetism has encountered obstacles due to material dispersion and absorption. This has led to a phenomenological approach to macroscopic quantum electrodynamics where no canonical formulation is attempted. In this paper macroscopic electromagnetism is canonically quantized. The results apply to any linear, inhomogeneous, magnetoelectric medium with dielectric functions that obey the Kramers-Kronig relations. The prescriptions of the phenomenological approach are derived from the canonical theory.
Advanced Model of Electromagnetic Launcher
Karel Leubner
2015-01-01
Full Text Available An advanced 2D model of electromagnetic launcher is presented respecting the influence of eddy currents induced in the accelerated ferromagnetic body. The time evolution of electromagnetic field in the system, corresponding forces acting on the projectile and time evolutions of its velocity and current in the field circuit are solved numerically using own application Agros2d. The results are then processed and evaluated in Wolfram Mathematica. The methodology is illustrated with an example whose results are discussed.
Radiation and propagation of electromagnetic waves
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
General Geometry and Geometry of Electromagnetism
Shahverdiyev, Shervgi S.
2002-01-01
It is shown that Electromagnetism creates geometry different from Riemannian geometry. General geometry including Riemannian geometry as a special case is constructed. It is proven that the most simplest special case of General Geometry is geometry underlying Electromagnetism. Action for electromagnetic field and Maxwell equations are derived from curvature function of geometry underlying Electromagnetism. And it is shown that equation of motion for a particle interacting with electromagnetic...
Lopes, Carlos A.; Moraes, Claudia C.D. [Eletricidade de Sao Paulo S.A. (ELETROPAULO), Sao Paulo, SP (Brazil); Fonseca, Carlos H.F. [Centrais Eletricas de Santa Catarina S.A., Florianopolis, SC (Brazil); Silva, Clecio Fabricio da; Alves, Ricardo P. [Companhia Paranaense de Energia (COPEL), Curitiba, PR (Brazil); Sposito, Edivaldo Soares; Hulle, Lutero [Espirito Santo Centrais Eletricas S.A. (ESCELSA), Vitoria, ES (Brazil); S. Martins, Icaro da [Centrais Eletricas do Norte do Brasil S.A. (ELETRONORTE), Belem, PA (Brazil); Vilhena, Joao Luiz S. de [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil); Fagundes, Zaluar Aquino [Companhia Estadual de Energia Eletrica do Estado do Rio Grande do Sul, Porto Alegre, RS (Brazil)
1996-12-31
An increase in the consumption of natural gas in Brazil is an expected fact in what concerns energetic planning. This work presents the existing situation in what concerns natural gas utilization in the main world economies, as well as an analysis of the participation of this fuel among the energy final consumption per sources. The Brazilian consumption of natural gas is also analysed as well as the international agreement between Brazil and Bolivia for natural gas commercialization. Some legal, institutional and political aspects related to natural gas commercialization are also discussed. Finally, several benefits to be brought by the utilization of natural gas are presented 10 refs., 3 tabs.
DYNAMICAL MODEL OF ELECTROMAGNETIC DRIVE
Trunev A. P.
2016-02-01
Full Text Available The article discusses the dynamic model of the rocket motor electromagnetic type, consisting of a source of electromagnetic waves of radio frequency band and a conical cavity in which electromagnetic waves are excited. The processes of excitation of electromagnetic oscillations in a cavity with conducting walls, as well as the waves of the YangMills field have been investigated. Multi-dimensional transient numerical model describing the processes of establishment of electromagnetic oscillations in a cavity with the conducting wall was created Separately, the case of standing waves in the cavity with conducting walls been tested. It is shown that the oscillation mode in the conducting resonator different from that in an ideal resonator, both in the steady and unsteady processes. The mechanism of formation of traction for the changes in the space-time metric, the contribution of particle currents, the Yang-Mills and electromagnetic field proposed. It is shown that the effect of the Yang-Mills field calls change the dielectric properties of vacuum, which leads to a change in capacitance of the resonator. Developed a dynamic model, which enables optimal traction on a significant number of parameters. It was found that the thrust increases in the Yang-Mills field parameters near the main resonance frequency. In the presence of thermal fluctuations and the Yang-Mills field as well the traction force changes sign, indicating the presence of various oscillation modes
SOLAR NANTENNA ELECTROMAGNETIC COLLECTORS
Steven D. Novack; Dale K. Kotter; Dennis Slafer; Patrick Pinhero
2008-08-01
This research explores a new efficient approach for producing electricity from the abundant energy of the sun. A nanoantenna electromagnetic collector (NEC) has been designed, prototyped, and tested. Proof of concept has been validated. The device targets mid-infrared wavelengths where conventional photovoltaic (PV) solar cells do not respond but is abundant in solar energy. The initial concept of designing NEC antennas was based on scaling of radio frequency antenna theory. This approach has proven unsuccessful by many due to not fully understanding and accounting for the optical behavior of materials in the THz region. Also until recent years the nanofabrication methods were not available to fabricate the optical antenna elements. We have addressed and overcome both technology barriers. Several factors were critical in successful implementation of NEC including: 1) frequency-dependent modeling of antenna elements, 2) selection of materials with proper THz properties and 3) novel manufacturing methods that enable economical large-scale manufacturing. The work represents an important step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity, which will lead to a wide spectrum, high conversion efficiency, and low cost solution to complement conventional PVs.
Introduction to engineering electromagnetics
Lee, Yeon Ho [Sungkyunkwan Univ., Kyongkido (Korea, Republic of). School of Information and Communication Engineering
2013-11-01
This book provides students with the missing link that can help them master the basic principles of electromagnetics. The concept of vector fields is introduced by starting with clear definitions of position, distance, and base vectors. The symmetries of typical configurations are discussed in detail, including cylindrical, spherical, translational, and two-fold rotational symmetries. To avoid serious confusion between symbols with two indices, the text adopts a new notation: a letter with subscript 1-2 for the work done in moving a unit charge from point 2 to point 1, in which the subscript 1-2 mimics the difference in potentials, while the hyphen implies a sense of backward direction, from 2 to 1. This book includes 300 figures in which real data are drawn to scale. Many figures provide a three-dimensional view. Each subsection includes a number of examples that are solved by examining rigorous approaches in steps. Each subsection ends with straightforward exercises and answers through which students can check if they correctly understood the concepts. A total 350 of examples and exercises are provided. At the end of each section, review questions are inserted to point out key concepts and relations discussed in the section. They are given with hints referring to the related equations and figures. The book contains a total of 280 end-of-chapter problems.
Electromagnetism of Bacterial Growth
Ainiwaer, Ailiyasi
2011-10-01
There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.
Nucleon Electromagnetic Form Factors
Kees de Jager
2004-08-01
Although nucleons account for nearly all the visible mass in the universe, they have a complicated structure that is still incompletely understood. The first indication that nucleons have an internal structure, was the measurement of the proton magnetic moment by Frisch and Stern (1933) which revealed a large deviation from the value expected for a point-like Dirac particle. The investigation of the spatial structure of the nucleon, resulting in the first quantitative measurement of the proton charge radius, was initiated by the HEPL (Stanford) experiments in the 1950s, for which Hofstadter was awarded the 1961 Nobel prize. The first indication of a non-zero neutron charge distribution was obtained by scattering thermal neutrons off atomic electrons. The recent revival of its experimental study through the operational implementation of novel instrumentation has instigated a strong theoretical interest. Nucleon electro-magnetic form factors (EMFFs) are optimally studied through the exchange of a virtual photon, in elastic electron-nucleon scattering. The momentum transferred to the nucleon by the virtual photon can be selected to probe different scales of the nucleon, from integral properties such as the charge radius to scaling properties of its internal constituents. Polarization instrumentation, polarized beams and targets, and the measurement of the polarization of the recoiling nucleon have been essential in the accurate separation of the charge and magnetic form factors and in studies of the elusive neutron charge form factor.
ELECTROMAGNET CALORIMETER (ECAL)
R. Rusack
Installation is under way of the last piece of the electromagnetic calorimeter. This is the preshower (ES) that sits in front of the two endcap calorimeters. The construction of the ES was completed in December and went through a detailed set of tests in December and January. The two preshower detectors have a total of 4300 silicon sensors with 137,000 strips. After final assembly and system testing in January, only two of the strips were found to be defective. Once CMS was fully opened a new support structure (‘Gazprom’) was put into place underneath the beam pipe, to support the Surkov platform, on which the preshower installation takes place. In the early hours of 26th February the first two Dees, which form the ‘ES+’ endcap, were transported to P5 , a journey that took two and a half hours. The Dees, still inside environmental protection boxes, were then lowered underground and moved to the ‘+’ end of CMS. Installation start...
Development of an electromagnetically actuated mercury microvalve
Adkins, D.R.; Wong, C.C.
1998-08-01
The development of microscale fluid handling components has been recognized as a crucial element in the design of microscale chemical detection systems. Recently, work has been undertaken at Sandia National Laboratories to construct a valve that uses a small mercury droplet to control the flow of gas through capillary passages. Electromagnetic forces that are provided by small permanent magnets and a current supply are used to drive the mercury into position. Driving the mercury droplet into a tapered passage halts gas flow through a capillary, while surface tension forces prevent the mercury from passing through the passage. Models have been developed to describe the movement of the mercury droplet and the sealing of the gas passage, and millimeter-scale units have been tested to explore design options. Predictions from the model show that a valve with 10 micron sized features can seal against pressures up to 1.5 atmospheres. Experiments have highlighted the promise of mercury valves and demonstrated problems that can arise from contamination of the mercury.
Electromagnetically induced transparency for x rays
Buth, Christian; Young, Linda
2007-01-01
Electromagnetically induced transparency (EIT) is predicted for x rays in laser-dressed neon gas. The x-ray photoabsorption cross section and polarizability near the Ne K edge are calculated using an ab initio theory suitable for optical strong-field problems. The laser wavelength is tuned close to the transition between 1s^-1 3s and 1s^-1 3p (approximately 800nm). The minimum laser intensity required to observe EIT is of the order of 10^12 W/cm^2. The ab initio results are discussed in terms of an exactly solvable three-level model. This work opens new opportunities for research with ultrafast x-ray sources.
Electromagnetically induced absorption in metastable 83Kr atoms
Kale, Y B; Mishra, S R; Singh, S; Rawat, H S
2015-01-01
We report electromagnetically induced absorption (EIA) resonances of sub-natural linewidth (FWHM) in metastable noble gas 83Kr* atoms using degenerate two level schemes (DTLSs). This is the first observation of EIA effect in a metastable noble gas atoms. Using these spectrally narrow EIA signals obtained corresponding to the closed hyperfine transition from 4p55s[3/2]2 to 4p55p[5/2]3 hyperfine manifolds of 83Kr* atoms, we have measured the Lande's g-factor (gF) for the lower level (F = 13/2) of the closed transition accurately with small applied magnetic fields of few Gauss.
Electromagnetic Armor Based on the Principles of Reconnection Electromagnetic Launcher
Yu Haiqing; Li Weitao; Gao Haizhen
2015-01-01
Active electromagnetic armor is the latest concept of defense system, and it is highly probable for this technology to be applied to many domains such as future tanks, armored vehicles and the armor of warships. The studies on active electromagnetic defense technology in the world have a history of decades. But, there still exist bottlenecks and the interceptor is one of them. This paper studies the problem of interceptors based on the principles of reconnection electromagnetic launcher and presents a kind of simulation model of it. A small scale laboratory model is made, and related experimental researches and theoretical analyses have been carried out when the projectiles are different kinds of material and shape. Satisfactory results are reached and agree with the theoretical analyses.
Electromagnetic aquametry electromagnetic wave interaction with water and moist substances
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.
Hernandez Martinez, Gaston
2007-12-15
The use of SF6 substations is actually an extensive practice in industrial countries. Some of they replace conventional air substations and the others are new designs in the range of 34.5 kV to 1000 kV. During the switching events in a GIS substation, very fast transients overvoltage may appear and originate faults, malfunctions in the electronic and control equipment, besides the risk by electrical discharge in the personnel who are working in the substation. These overvoltage are produced by the collapse of the electric field on GIS terminals during switching events originating Very Fast Transient Overvoltage (VFTO) and the increase of the Transient Enclosure Voltage (TEV). This investigation is focused on diminishing the magnitude of the VFTO and TEV by designing and redesigning grounding grids for gas insulated substations in SF6. The objective of this work is to design a grounding grid for an air substation and redesign it for a GIS substation. The computer simulation uses a detailed model of the substation in SF6 interconnected with an aerial grounding grid and by adding methodologically grounding rods, the VFTO and TEV within the GIS are reduced. The results of the computer simulation show that the designed grounding grid allows considerably diminishing the magnitude of the VFTO; nevertheless this design doesn't appropriately attenuate the TEV magnitude. [Spanish] Hoy en dia, el uso de subestaciones GIS se ha generalizado. Algunas reemplazan a las subestaciones aereas y otras son de nueva creacion y se instalan en tensiones de 34.5kV hasta 1000 kV. Durante las operaciones de maniobra de la subestacion GIS, se presentan sobretensiones transitorias ultra rapidas que pueden dar origen a diversas fallas, a un malfuncionamiento del equipo electronico y de control asi como el riesgo por descarga electrica al personal que labora en la subestacion. Estas sobretensiones se producen debido al colapso del campo electrico en terminales del interruptor ante
CIME School on "Computational Electromagnetism"
Valli, Alberto
2015-01-01
Presenting topics that have not previously been contained in a single volume, this book offers an up-to-date review of computational methods in electromagnetism, with a focus on recent results in the numerical simulation of real-life electromagnetic problems and on theoretical results that are useful in devising and analyzing approximation algorithms. Based on four courses delivered in Cetraro in June 2014, the material covered includes the spatial discretization of Maxwell’s equations in a bounded domain, the numerical approximation of the eddy current model in harmonic regime, the time domain integral equation method (with an emphasis on the electric-field integral equation) and an overview of qualitative methods for inverse electromagnetic scattering problems. Assuming some knowledge of the variational formulation of PDEs and of finite element/boundary element methods, the book is suitable for PhD students and researchers interested in numerical approximation of partial differential equations and scienti...
Advanced electromagnetics and scattering theory
2015-01-01
This book present the lecture notes used in two courses that the late Professor Kasra Barkeshli had offered at Sharif University of Technology, namely, Advanced Electromagnetics and Scattering Theory. The prerequisite for the sequence is vector calculus and electromagnetic fields and waves. Some familiarity with Green's functions and integral equations is desirable but not necessary. The book provides a brief but concise introduction to classical topics in the field. It is divided into three parts including annexes. Part I covers principle of electromagnetic theory. The discussion starts with a review of the Maxwell's equations in differential and integral forms and basic boundary conditions. The solution of inhomogeneous wave equation and various field representations including Lorentz's potential functions and the Green's function method are discussed next. The solution of Helmholtz equation and wave harmonics follow. Next, the book presents plane wave propagation in dielectric and lossy media and various...
Moving Manifolds in Electromagnetic Fields
David V. Svintradze
2017-08-01
Full Text Available We propose dynamic non-linear equations for moving surfaces in an electromagnetic field. The field is induced by a material body with a boundary of the surface. Correspondingly the potential energy, set by the field at the boundary can be written as an addition of four-potential times four-current to a contraction of the electromagnetic tensor. Proper application of the minimal action principle to the system Lagrangian yields dynamic non-linear equations for moving three dimensional manifolds in electromagnetic fields. The equations in different conditions simplify to Maxwell equations for massless three surfaces, to Euler equations for a dynamic fluid, to magneto-hydrodynamic equations and to the Poisson-Boltzmann equation.
Electromagnetic contributions to pseudoscalar masses
Basak, S; Bernard, C; DeTar, C; Freeland, E; Freeman, W; Foley, J; Gottlieb, Steven; Heller, U M; Hetrick, J E; Laiho, J; Levkova, L; Oktay, M; Osborn, J; Sugar, R L; Torok, A; Toussaint, D; Van de Water, R S; Zhou, R
2013-01-01
We report on the calculation by the MILC Collaboration of the electromagnetic effects on kaon and pion masses. These masses are computed in QCD with dynamical (asqtad staggered) quarks plus quenched photons at three lattice spacings varying from 0.12 to 0.06 fm. The masses are fit to staggered chiral perturbation theory with NLO electromagnetic terms, as well as analytic terms at higher order. We extrapolate the results to physical light-quark masses and to the continuum limit. At the current stage of the analysis, most, but not all, of the systematic errors have been estimated. The main goal is the comparison of kaon electromagnetic splittings to those of the pion, i.e., an evaluation of the corrections to "Dashen's theorem." This in turn will allow us to significantly reduce the systematic errors in our determination of m_u/m_d.
Traditional beliefs and electromagnetic fields
Colin A. Ross
2011-09-01
Full Text Available The author proposes that a wide range of traditional beliefs and practices may provide clues to real electromagnetic field interactions in the biosphere. For instance, evil eye beliefs may be a cultural elaboration of the sense of being stared at, which in turn may have a basis in real electromagnetic emissions through the eye. Data to support this hypothesis are presented. Other traditional beliefs such as remote sensing of game and the importance of connection to the Earth Mother may also contain a kernel of truth. A series of testable scientific hypotheses concerning traditional beliefs and electromagnetic fields is presented. At this stage, the theory does not have sufficient evidence to be accepted as proven; its purpose is to stimulate thought and research
Electromagnetic fields in biological systems
Lin, James C
2016-01-01
As wireless technology becomes more sophisticated and accessible to more users, the interactions of electromagnetic fields with biological systems have captured the interest not only of the scientific community but also the general public. Unintended or deleterious biological effects of electromagnetic fields and radiation may indicate grounds for health and safety precautions in their use. Spanning static fields to terahertz waves, Electromagnetic Fields in Biological Systems explores the range of consequences these fields have on the human body. With contributions by an array of experts, topics discussed include: Essential interactions and field coupling phenomena, highlighting their importance in research on biological effects and in scientific, industrial, and medical applications Electric field interactions in cells, focusing on ultrashort, pulsed high-intensity fields The effect of exposure to naturally occurring and human-made static, low-frequency, and pulsed magnetic fields in biological systems Dosi...
Electromagnetic Fields and Bioenergy Phenomenon
İlhan Koşalay
2014-08-01
Full Text Available Electromagnetic energy is defined in the large frequency range and it shows its existence in different manners for every frequency range. When considering history of mankind, discovery of the electricity and presence of electrical and electronics based equipments is not very old. Human beings are exposed to electromagnetic fields and waves which they aren't used to live with those fields for ages. In this connection, lots of studies were done for the thesis of that these fields can produce harmful effects on people. Although results of the studies which were done in this area point out important subjects, sufficient outputs and judgments haven't been appeared yet in general meaning. This study was done to introduce findings which support that electromagnetic energy in some frequency can have beneficial effects on the living being.
Electromagnetic nature of dark energy
Jimenez, Jose Beltran
2009-01-01
Out of the four components of the electromagnetic field, Maxwell's theory only contains two physical degrees of freedom. However, in an expanding universe, consistently eliminating one of the "unphysical" states in the covariant (Gupta-Bleuler) formalism turns out to be difficult to realize. In this work we explore the possibility of quantization without subsidiary conditions. This implies that the theory would contain a third physical state. The presence of such a new (temporal) electromagnetic mode on cosmological scales is shown to generate an effective cosmological constant which can account for the accelerated expansion of the universe. This new polarization state is completely decoupled from charged matter, but can be excited gravitationally. In fact, primordial electromagnetic quantum fluctuations produced during electroweak scale inflation could naturally explain the presence of this mode and also the measured value of the cosmological constant. The theory is compatible with all the local gravity test...
Objects of maximum electromagnetic chirality
Fernandez-Corbaton, Ivan
2015-01-01
We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.
Perturbations in electromagnetic dark energy
Jiménez, Jose Beltrán; Maroto, Antonio L. [Departamento de Física Teórica, Universidad Complutense de Madrid, 28040 Madrid (Spain); Koivisto, Tomi S. [Institute for Theoretical Physics, University of Heidelberg, 69120 Heidelberg (Germany); Mota, David F., E-mail: jobeltra@fis.ucm.es, E-mail: T.Koivisto@thphys.uni-heidelberg.de, E-mail: maroto@fis.ucm.es, E-mail: d.f.mota@astro.uio.no [Institute of Theoretical Astrophysics, University of Oslo, 0315 Oslo (Norway)
2009-10-01
It has been recently proposed that the presence of a temporal electromagnetic field on cosmological scales could explain the phase of accelerated expansion that the universe is currently undergoing. The field contributes as a cosmological constant and therefore, the homogeneous cosmology produced by such a model is exactly the same as that of ΛCDM. However, unlike a cosmological constant term, electromagnetic fields can acquire perturbations which in principle could affect CMB anisotropies and structure formation. In this work, we study the evolution of inhomogeneous scalar perturbations in this model. We show that provided the initial electromagnetic fluctuations generated during inflation are small, the model is perfectly compatible with both CMB and large scale structure observations at the same level of accuracy as ΛCDM.
Gauge Invariant Fractional Electromagnetic Fields
Lazo, Matheus Jatkoske
2011-01-01
Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators.
Circuit modeling for electromagnetic compatibility
Darney, Ian B
2013-01-01
Very simply, electromagnetic interference (EMI) costs money, reduces profits, and generally wreaks havoc for circuit designers in all industries. This book shows how the analytic tools of circuit theory can be used to simulate the coupling of interference into, and out of, any signal link in the system being reviewed. The technique is simple, systematic and accurate. It enables the design of any equipment to be tailored to meet EMC requirements. Every electronic system consists of a number of functional modules interconnected by signal links and power supply lines. Electromagnetic interference
Electromagnetic compatibility principles and applications
Weston, David A
2001-01-01
This totally revised and expanded reference/text provides comprehensive, single-source coverage of the design, problem solving, and specifications of electromagnetic compatibility (EMC) into electrical equipment/systems-including new information on basic theories, applications, evaluations, prediction techniques, and practical diagnostic options for preventing EMI through cost-effective solutions. Offers the most recent guidelines, safety limits, and standards for human exposure to electromagnetic fields! Containing updated data on EMI diagnostic verification measurements, as well as over 900 drawings, photographs, tables, and equations-500 more than the previous edition
Revisiting quaternion formulation and electromagnetism
Negi, O.P.S.; Bisht, S.; Bisht, P.S. [Almara, Kumaun Univ. (India). Dept. of Physics
1998-12-01
Demonstrating the isomorphic matrix representation of biquaternions the dynamical variables. Maxwell`s equation and equation of motion are derived in compact and expanded forms, respectively, for quaternions and matrix representations. Isomorphic matrix representation has also been carried out to describe the generalized electromagnetism in the presence of magnetic monopole. Biquaternion Lorentz transformation mapping and the elementary transformation for various matrix representation of quaternion units are also analysed. It is shown that the biquaternion theory of generalized electromagnetic fields enhances the dimensionality of the representation from 4-dimensional linear vector space.
Pre-Seismic Electromagnetic Effects
Guo Yahong
2007-01-01
Along with intense rock strain and rock bursting processes at the late stage of earthquake preparation, mechanical-electrical energy conversion appears in the seismogenic region and its nearby rock formations, which correspondingly stimulate certain electromagnetic effects. The paper mainly analyzes the pre-seismic electromagnetic effect of the ionosphere and proposes a method of monitoring VLF radio waves over the additional ionized region and so on. It is deemed that the method is of significance for short and imminent term prediction of strong earthquakes.
Electromagnetic geothermometry theory, modeling, practice
Spichak, Viacheslav V
2015-01-01
Electromagnetic Geothermometry explores, presents and explains the new technique of temperature estimation within the Earth's interior; the Electromagnetic technique will identify zones of geothermal anomalies and thus provides locations for deep drilling. This book includes many case studies from geothermal areas such as Travale (Italy), Soultz-sous-Forêts (France) and Hengill (Iceland), allowing the author and reader to draw conclusions regarding the dominating heat transfer mechanisms, location of its sources and to constrain the locations for drilling of the new boreholes. Covering a to
Mathematical methods of electromagnetic theory
Friedrichs, Kurt O
2014-01-01
This text provides a mathematically precise but intuitive introduction to classical electromagnetic theory and wave propagation, with a brief introduction to special relativity. While written in a distinctive, modern style, Friedrichs manages to convey the physical intuition and 19th century basis of the equations, with an emphasis on conservation laws. Particularly striking features of the book include: (a) a mathematically rigorous derivation of the interaction of electromagnetic waves with matter, (b) a straightforward explanation of how to use variational principles to solve problems in el
Integral equation methods for electromagnetics
Volakis, John
2012-01-01
This text/reference is a detailed look at the development and use of integral equation methods for electromagnetic analysis, specifically for antennas and radar scattering. Developers and practitioners will appreciate the broad-based approach to understanding and utilizing integral equation methods and the unique coverage of historical developments that led to the current state-of-the-art. In contrast to existing books, Integral Equation Methods for Electromagnetics lays the groundwork in the initial chapters so students and basic users can solve simple problems and work their way up to the mo
Measurement of advanced electromagnetic radiation
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...
Electromagnetic Gun With Commutated Coils
Elliott, David G.
1991-01-01
Proposed electromagnetic gun includes electromagnet coil, turns of which commutated in sequence along barrel. Electrical current fed to two armatures by brushes sliding on bus bars in barrel. Interaction between armature currents and magnetic field from coil produces force accelerating armature, which in turn, pushes on projectile. Commutation scheme chosen so magnetic field approximately coincides and moves with cylindrical region defined by armatures. Scheme has disadvantage of complexity, but in return, enables designer to increase driving magnetic field without increasing armature current. Attainable muzzle velocity increased substantially.
Electromagnetic Fields and Public Health: Mobile Phones
... sheets Fact files Questions & answers Features Multimedia Contacts Electromagnetic fields and public health: mobile phones Fact sheet N° ... an estimated 6.9 billion subscriptions globally. The electromagnetic fields produced by mobile phones are classified by the ...
Higher-order techniques in computational electromagnetics
Graglia, Roberto D
2016-01-01
Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.
Electromagnetic field anomalies above an isometric depression
Golubtsova, N. S.
1981-12-01
The paper examines the three-dimensional simulation of the electromagnetic field above an isometric depression with conducting deposits. The model makes it possible to study the development of electromagnetic anomalies over such a depression and to make qualitative as well as quantitative assessments of the dependence of electromagnetic anomalies on field frequency, the dimensions of geoelectric inhomogeneities, and the specific resistance of the foundation of the depression. The present approach can be used in geoelectric and magnetotelluric studies of electromagnetic anomalies.
Wang Jiang
2014-03-01
Full Text Available When partial discharge occurs in Gas Insulated Switchgear (GIS with insulation defects, Ultrahigh-Frequency (UHF electromagnetic wave up to several MHz and GHz will be exited and propagate inside GIS cavity. This study, based on the propagation theory of electromagnetic waves in coaxial waveguide, performs simulation analysis of the relationship between PD pulse form and the exited UHF electromagnetic wave using Finite-Deferential Time-Domain (FDTD algorithm. First, we study the relationship of partial discharge magnitude and electric field strength of electromagnetic wave. It is found that the changes of partial discharge magnitude have little effect on electric field strength of electromagnetic wave at certain variation rate of PD pulse current. Next, we examine the relationship of variation rate of PD pulse current to electric field strength of electromagnetic wave. It is pointed out that, at a certain partial discharge magnitude, the two are approximately linearly related. Finally, we study the impact of variation rate of PD pulse current on higher mode components. Variation coefficient is used to analyze the proportion of higher mode components in electromagnetic wave. The proportion of higher mode components increases with increasing variation rate of PD pulse current.
New Concepts in Electromagnetic Materials and Antennas
2015-01-01
AFRL-RY-WP-TR-2014-0233 NEW CONCEPTS IN ELECTROMAGNETIC MATERIALS AND ANTENNAS Jeffrey Allen, Naftali Herscovici, Brad Kramer, and...Bae-Ian Wu Antennas & Electromagnetics Technology Branch Multispectral Sensing & Detection Division JANUARY 2015 Final Report...Signature// //Signature// BRADLEY A. KRAMER, Program Manager TONY C. KIM, Branch Chief Antenna & Electromagnetic Technology
Some Student Conceptions of Electromagnetic Induction
Thong, Wai Meng; Gunstone, Richard
2008-01-01
Introductory electromagnetism is a central part of undergraduate physics. Although there has been some research into student conceptions of electromagnetism, studies have been sparse and separated. This study sought to explore second year physics students' conceptions of electromagnetism, to investigate to what extent the results from the present…
Explanations, Education, and Electromagnetic Fields.
Friedman, Sharon M.
Explaining complex scientific and environmental subjects in the mass media is difficult to do, particularly under such constraints as short deadlines and lack of space or time. When a scientific controversy and human health risk are involved, this becomes an even harder task to accomplish. The subject of electromagnetic fields (EMF) involves…
Electromagnetic Levitation of a Disc
Valle, R.; Neves, F.; de Andrade, R., Jr.; Stephan, R. M.
2012-01-01
This paper presents a teaching experiment that explores the levitation of a disc of ferromagnetic material in the presence of the magnetic field produced by a single electromagnet. In comparison to the classical experiment of the levitation of a sphere, the main advantage of the proposed laboratory bench is that the uniform magnetic field…
Electromagnetic transfer information in medicine
Settimio Grimaldi
2012-09-01
Full Text Available Background: Only recently has the critical importance of electromagnetic (EM field interactions in biology and medicine been recognized. We review the phenomenon of resonance signaling, discussing how specific frequencies modulate cellular function to restore or maintain health. Evidence: Application of EM tuned signals represents more than merely a new tool in Information Medicine. It can also be viewed in the larger context of Electromagnetic Medicine, the all-encompassing view that elevates the electromagnetic over the biochemical. The discovery by Zhadin that ultrasmall magnetic intensities are biologically significant suggests that EM signaling is endogenous to cell regulation, and consequently that the remarkable effectiveness of EM resonance treatments reflects a fundamental aspect of biological systems. The concept that organisms contain mechanisms for generating biologically useful electric signals is not new, dating back to the 19th century discovery of currents of injury by Matteucci. The corresponding modern-day version is that ion cyclotron resonance magnetic field combinations help regulate biological information. Prospects: The next advance in medicine will be to discern and apply those electromagnetic signaling parameters acting to promote wellness, with decreasing reliance on marginal biochemical remediation and pharmaceuticals.
$\\Delta$-N Electromagnetic Transition
Loan, M
1999-01-01
The EM ratio for a free Delta electromagnetic transition is discussed within the frame work of nonrelativistic approach. Such an approach gives a good account of data for a free Delta but is less important for an intrinsically relativistic nuclear many body problem.
Fast electromagnetic field strength probes
Leferink, Frank; Serra, Ramiro
2013-01-01
Diode detectors and thermocouple detectors are conventionally used to measure electromagnetic field strength. Both detectors have some disadvantages for applications where a fast response and a high dynamic range is required. The diode detector is limited in dynamic range. The dynamic range is impor
Operation of Electromagnetic Isotope Separator
MI; Ya-jing
2015-01-01
In 2015,we mainly completed the installation of the electromagnetic isotope separator comprehensive technical transformation projects,including the work of installation,debugging,commissioning and acceptance.In June 30,2015,according to the schedule requirements,the project
Proposed electromagnetic wave energy converter
Bailey, R. L.
1973-01-01
Device converts wave energy into electric power through array of insulated absorber elements responsive to field of impinging electromagnetic radiation. Device could also serve as solar energy converter that is potentially less expensive and fragile than solar cells, yet substantially more efficient.
Electromagnetic Levitation of a Disc
Valle, R.; Neves, F.; de Andrade, R., Jr.; Stephan, R. M.
2012-01-01
This paper presents a teaching experiment that explores the levitation of a disc of ferromagnetic material in the presence of the magnetic field produced by a single electromagnet. In comparison to the classical experiment of the levitation of a sphere, the main advantage of the proposed laboratory bench is that the uniform magnetic field…
Extrinsic electromagnetic chirality in metamaterials
Plum, E.; Fedotov, V. A.; Zheludev, N. I.
2009-01-01
Three- and two-dimensional chirality arising from the mutual orientation of non-chiral planar metamaterial structures and the incident electromagnetic wave (extrinsic chirality) lead to pronounced optical activity, circular dichroism and asymmetric transmission indistinguishable from those seen in media consisting of three- and two-dimensionally chiral molecules (intrinsic chirality).
Biological effects of electromagnetic fields
2012-02-28
Feb 28, 2012 ... cell level studies have shown that electromagnetic fields do not have a directly .... The ionic flows, which can be formed in case these molecules are affected from ...... Electr Magn Biol Med 1st Orlando FL. 13. Magnusson M ...
Coupling Electromagnetism to Global Charge
Guendelman, Eduardo
2013-01-01
It is shown that an alternative to the standard scalar QED is possible. In this new version there is only global gauge invariance as far as the charged scalar fields are concerned although local gauge invariance is kept for the electromagnetic field. The electromagnetic coupling has the form $j_\\mu (A^{\\mu} +\\partial^{\\mu}B)$ where $B$ is an auxiliary field and the current $j_\\mu$ is $A_{\\mu}$ independent so that no "sea gull terms" are introduced. In a model of this kind spontaneous breaking of symmetry does not lead to photon mass generation, instead the Goldstone boson becomes a massless source for the electromagnetic field. Infrared questions concerning the theory when spontaneous symmetry breaking takes place and generalizations to global vector QED are discussed. In this framework Q-Balls and other non topological solitons that owe their existence to a global U(1) symmetry can be coupled to electromagnetism and could represent multiply charged particles now in search in the LHC. Finally, we give an exam...
Radiation leakage from electromagnetic oven
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.
Landau levels for electromagnetic wave
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.
Cardiovascular Responses to Electromagnetic Radiation
Dr Olaleye Samuel
3Optoelectronics and Measurement Techniques Laboratory, Department of Electrical Engineering, 9014 University of Oulu, ... much less man made electromagnetic activity. ... the heart rate remains constant, the mobile phone opening and closing can be reflected in the ..... permeability in mammalian brain 7 days days after.
Synthetic aperture controlled source electromagnetics
Fan, Y.; Snieder, R.; Slob, E.; Hunziker, J.W.; Singer, J.; Sheiman, J.; Rosenquist, M.
2010-01-01
Controlled‐source electromagnetics (CSEM) has been used as a de‐risking tool in the hydrocarbon exploration industry. Although there have been successful applications of CSEM, this technique is still not widely used in the industry because the limited types of hydrocarbon reservoirs CSEM can detect.
Heat Radiators for Electromagnetic Pumps
Campana, R. J.
1986-01-01
Report proposes use of carbon/carbon composite radiators in electromagnetic coolant pumps of nuclear reactors on spacecraft. Carbon/carbon composite materials function well at temperatures in excess of 2,200 K. Aluminum has melting temperature of only 880 K.
Nanocomposites for electromagnetic radiation protection
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.
Full Hydrodynamic Model of Nonlinear Electromagnetic Response in Metallic Metamaterials
Fang, Ming; Sha, Wei E I; Xiong, Xiaoyan Y Z; Wu, Xianliang
2016-01-01
Applications of metallic metamaterials have generated significant interest in recent years. Electromagnetic behavior of metamaterials in the optical range is usually characterized by a local-linear response. In this article, we develop a finite-difference time-domain (FDTD) solution of the hydrodynamic model that describes a free electron gas in metals. Extending beyond the local-linear response, the hydrodynamic model enables numerical investigation of nonlocal and nonlinear interactions between electromagnetic waves and metallic metamaterials. By explicitly imposing the current continuity constraint, the proposed model is solved in a self-consistent manner. Charge, energy and angular momentum conservation laws of high-order harmonic generation have been demonstrated for the first time by the Maxwell-hydrodynamic FDTD model. The model yields nonlinear optical responses for complex metallic metamaterials irradiated by a variety of waveforms. Consequently, the multiphysics model opens up unique opportunities f...
The electromagnetic coupling and the dark side of the Universe
Bento, M C; Torres, P
2007-01-01
We examine the properties of dark energy and dark matter through the study of the variation of the electromagnetic coupling. For concreteness, we consider the unification model of dark energy and dark matter, the generalized Chaplygin gas model (GCG), characterized by the equation of state $p=-\\frac{A}{\\rho^\\alpha}$, where $p$ is the pressure, $\\rho$ is the energy density and $A$ and $\\alpha$ are positive constants. The coupling of electromagnetism with the GCG's scalar field can give rise to such a variation. We compare our results with experimental data, and find that the degeneracy on parameters $\\alpha$ and $A_s$, $A_s \\equiv A / \\rho_{ch0}^{1+\\alpha}$, is considerable.
The Electromagnetic Compatibility Research Group: research questions
Francisco José Román Campos
2010-06-01
Full Text Available This paper summarises the Universidad Nacional de Colombia’s Electrical and Electronic Engineering Department’s Electromag- netic Compatibility Research Group (EMC-UNC activities during the last 30 years. The group was involved in developing experimental tools during the early 1980s, such as constructing high-voltage apparatus, developing high-voltage practical work for students and observing electrical discharges. These tools enabled the group to spend a decade focused on resolving one of the Colombian electrical sector’s main EMC problems: distribution transformer’s failures caused by lightning. For almost a decade this investigation was focused on understanding the causes of the extremely high failure index in Colombian rural areas, especially in the Rionegro basin. The main result of this investigation was a reduction by one order of magnitude in mean 10% distribution transformer failure rate. During this research work a noticeable pattern was observed of several electrically-isolated me- tallic bodies immersed in an electric field (i.e. floating electrodes. This was led to initiating floating electrode studies and for mulating a new scientific question, “How do corona electrical discharges interact with floating electrodes?” This new research question was dealt with during the second half of the 1990s and the first decade of the 2000s. This investigation was related to using electrostatically-accumulated charge on a floating electrode. This question opened up four research areas: gas discharge physics, generating fast current impulses, harvesting energy from the electric field and the possibility of high impedance current sources. This paper has summarised the most relevant work done by the EMC-UNC group on these topics. This floating electrode research work started by formulating four patents. Fresh research questions for the 2010s were related to measuring lightning electromagnetic pulses (LEMP, intentional electromagnetic
Yang, Ok Ryong
2004-01-15
This book introduces gas turbine cycle explaining general thing of gas turbine, full gas turbine cycle, Ericson cycle and Brayton cycle, practical gas turbine cycle without pressure loss, multiaxial type gas turbine cycle and special gas turbine cycle, application of basic theory on a study on suction-cooling gas turbine cycle with turbo-refrigerating machine using the bleed air, and general performance characteristics of the suction-cooling gas turbine cycle combined with absorption-type refrigerating machine.
A System for Electromagnetic Field Conversion
2003-01-01
A system is provided for conversion of a first electromagnetic field into a desired second electromagnetic field, for example for coupling modes between waveguides or into microstructured waveguides. The system comprises a complex spatial electromagnetic field converter that is positioned...... for reception of at least a part of the first electromagnetic field and that is adapted for conversion of the received field into the desired electromagnetic field, and wherein at least one of the first and second fields matches a mode of a microstructured waveguide. It is an important advantage of the present...
Particle Physics in Intense Electromagnetic Fields
Kurilin, A V
1999-01-01
The quantum field theory in the presence of classical background electromagnetic fields is reviewed. We give a pedagogical introduction to the Feynman-Furry method of describing non-perturbative interactions with very strong electromagnetic fields. A particular emphasis is given to the case of the plane-wave electromagnetic field for which the charged particles' wave functions and propagators are presented. Some general features of quantum processes proceeding in the intense electromagnetic background are argued. We also discuss the possibilities of searching new physics through the investigations of quantum phenomena induced by the strong electromagnetic environment.
Strong permanent magnet-assisted electromagnetic undulator
Halbach, Klaus
1988-01-01
This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles.
2016-01-01
The paper refers to the design of a direct current electromagnet, located on the head of a swan neck welding gun of a MIG welding equipment and used for magnetising the rotation space of two additional electric arches, in order to preheat the electrode wire and of the protective gas, partially turned into plasma jet. One describes the MIG welding method in which the electromagnet is used as well as its preliminary calculus.
Tudorel Ene
2016-10-01
Full Text Available The paper refers to the design of a direct current electromagnet, located on the head of a swan neck welding gun of a MIG welding equipment and used for magnetising the rotation space of two additional electric arches, in order to preheat the electrode wire and of the protective gas, partially turned into plasma jet. One describes the MIG welding method in which the electromagnet is used as well as its preliminary calculus.
Electromagnetic Transients in Power Cables
Silva, Filipe Faria Da; Bak, Claus Leth
of electromagnetic phenomena associated to their operation, among them electromagnetic transients, increased as well. Transient phenomena have been studied since the beginning of power systems, at first using only analytical approaches, which limited studies to more basic phenomena; but as computational tools became...... concerning HVAC cables. An important topic that is not covered in this book is measurements protocols/ methods. The protocols used when performing measurements on a cable depend on what is to be measured, the available equipment and accessibility. Readers interested in the topic are referred to search....... The chapter ends by proposing a systematic method that can be used when doing the insulation co-ordination study for a line, as well as the modelling requirements, both modelling depth and modelling detail of the equipment, for the study of the different types of transients followed by a step-by-step generic...
Electromagnetic waves in variable media
Brosa, Ulrich [Brosa GmbH, Amoeneburg (Germany); Marburg Univ. (Germany)
2012-03-15
Two methods are explained to exactly solve Maxwell's equations where permittivity, permeability, and conductivity may vary in space. In the constitutive relations, retardation is regarded. If the material properties depend but on one coordinate, general solutions are derived. If the properties depend on two coordinates, geometrically restricted solutions are obtained. Applications to graded reflectors, especially to dielectric mirrors, to filters, polarizers, and to waveguides, plain and cylindrical, are indicated. New foundations for the design of optical instruments, which are centered around an axis, and for the design of invisibility cloaks, plain and spherical, are proposed. The variability of material properties makes possible effects which cannot happen in constant media, e.g. stopping the flux of electromagnetic energy without loss. As a consequence, spherical devices can be constructed which bind electromagnetic waves. (orig.)
Electromagnetic force distribution inside matter
Mansuripur, Masud; Wright, Ewan M
2013-01-01
Using the Finite Difference Time Domain method, we solve Maxwell's equations numerically and compute the distribution of electromagnetic fields and forces inside material media. The media are generally specified by their dielectric permittivity epsilon(w) and magnetic permeability mu(w), representing small, transparent dielectric and magnetic objects such as platelets and micro-beads. Using two formulations of the electromagnetic force-density, one due to H. A. Lorentz [Collected Papers 2, 164 (1892)], the other due to A. Einstein and J. Laub [Ann, Phys. 331, 541 (1908)], we show that the force-density distribution inside a given object can differ substantially between the two formulations. This is remarkable, considering that the total force experienced by the object is always the same, irrespective of whether the Lorentz or the Einstein-Laub formula is employed. The differences between the two formulations should be accessible to measurement in deformable objects.
Properties of dynamical electromagnetic metamaterials
Padilla, Willie J.; Averitt, Richard D.
2017-08-01
Electromagnetic metamaterials consist of two or three dimensional arrays of tailored metallic and/or dielectric inclusions and provide unprecedented sub-wavelength control over light-matter interactions. Metamaterials are fashioned to yield a specific response to the electric and magnetic components of light and may be treated as effective media, described by effective optical constants {μ }{{eff}} and {{ɛ }}{{eff}}, and have realized a multitude of exotic properties difficult to achieve with natural materials. An inductive-capacitive unit cell geometry provides enhanced values of optical constants, as well as the ability to dynamically control the novel responses exhibited by electromagnetic metamaterials. The ability of metamaterials to achieve real-time dynamic properties has realized novel applications and has made them relevant for the next revolution in advanced materials and related devices.
Electromagnetically Induced Quantum Holographic Imaging
Qiu, Tian-Hui; Xie, Min; Ma, Hong-Yang; Zheng, Chun-Hong; Chen, Li-Bo
2016-05-01
We study the quantum holographic imaging of one-dimensional electromagnetically induced grating created by a strong standing wave in an atomic medium. Entangled photon pairs, generated in a spontaneous parametric down-conversion process, are employed as the imaging light to realize coincidence recording. By theoretical analysis and numerical simulation, we find that both the amplitude and phase information of the object can be imaged with the characteristic of imaging nonlocally and of arbitrarily controllable image variation in size.
Neutrinos and electromagnetic gauge invariance
Pisano, F.; Silva-Sobrinho, J.A. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Tonasse, M.D. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Fisica
1996-02-01
It is discussed a recently proposed connection among electromagnetic gauge invariance U(1){sub em} and the nature of the neutrino mass terms in the framework of SU(3){sub C} x G{sub W} x U(1){sub N}, G{sub W} SU(3){sub L}, extensions of the Standard Model. The impossibility of that connection, also in the case G{sub W} = SU(4){sub L}, is demonstrated. (author). 7 refs.
Electromagnetic Calorimeter for HADES Experiment
Rodríguez-Ramos P.
2014-01-01
Full Text Available Electromagnetic calorimeter (ECAL is being developed to complement dilepton spectrometer HADES. ECAL will enable the HADES@FAIR experiment to measure data on neutral meson production in heavy ion collisions at the energy range of 2-10 AGeV on the beam of future accelerator SIS100@FAIR. We will report results of the last beam test with quasi-monoenergetic photons carried out in MAMI facility at Johannes Gutenberg Universität Mainz.
Electromagnetism Tutorial (Tutorial de Eletromagnetismo)
Dantas, Christine C
2009-01-01
The present tutorial aims at covering the fundamentals of electromagnetism, in a condensed and clear manner. Some solved and proposed exercises have been included. The reader is assumed to have knowledge of basic electricity, partial derivatives and multiple integrals. ----- O presente tutorial visa cobrir os fundamentos do eletromagnetismo, de forma condensada e clara. Alguns exercicios resolvidos e propostos foram incluidos. Assume-se conhecimento de eletricidade basica, derivadas parciais e integrais multiplas.
Electromagnetic calorimeter trigger at Belle
Cheon, B G; Lee, S H; Won, E; Park, I C; Hur, T W; Park, C S; Kim, S K; Kim, H J; Kim, H O; Chu, T H; Usov, Y V; Aulchenko, V M; Kuzmin, A S; Bondar, A E; Shwartz, B A; Eidelman, S; Krokovnyi, P P; Hayashii, H; Sagawa, H; Fukushima, M
2002-01-01
The performance of CsI(Tl) electromagnetic calorimeter trigger system in the Belle experiment is described. Two kinds of trigger schemes have been taken into account, namely a total energy trigger and a cluster counting trigger which are complementary to each other. In addition, the system has provided the online/offline luminosity information using the Bhabha event trigger scheme. An upgrade of the trigger is discussed.
Electromagnetic hypersensitivity: Fact or fiction?
Genuis, Stephen J., E-mail: sgenuis@ualberta.ca [University of Alberta (Canada); Lipp, Christopher T. [Faculty of Medicine at the University of Calgary (Canada)
2012-01-01
As the prevalence of wireless telecommunication escalates throughout the world, health professionals are faced with the challenge of patients who report symptoms they claim are connected with exposure to some frequencies of electromagnetic radiation (EMR). Some scientists and clinicians acknowledge the phenomenon of hypersensitivity to EMR resulting from common exposures such as wireless systems and electrical devices in the home or workplace; others suggest that electromagnetic hypersensitivity (EHS) is psychosomatic or fictitious. Various organizations including the World Health Organization as well as some nation states are carefully exploring this clinical phenomenon in order to better explain the rising prevalence of non-specific, multi-system, often debilitating symptoms associated with non-ionizing EMR exposure. As well as an assortment of physiological complaints, patients diagnosed with EHS also report profound social and personal challenges, impairing their ability to function normally in society. This paper offers a review of the sparse literature on this perplexing condition and a discussion of the controversy surrounding the legitimacy of the EHS diagnosis. Recommendations are provided to assist health professionals in caring for individuals complaining of EHS. - Highlights: Black-Right-Pointing-Pointer Many people report symptoms when near devices emanating electromagnetic fields(EMF). Black-Right-Pointing-Pointer Electromagnetic hypersensitivity (EHS) research has generated conflicting outcomes. Black-Right-Pointing-Pointer Recent evidence suggests pathophysiological change in some individuals with EHS. Black-Right-Pointing-Pointer EHS patients consistently report profound social and personal challenges. Black-Right-Pointing-Pointer Clinicians need to be apprised of the EHS condition and potential interventions.
Vertical Electromagnetic Pulse (VEMP) Testing
2009-09-11
Device Measurement Accuracy Current Current Probes ±5% E-Field D-Dot Probe ±5% H-field B-Dot Probe ±5% Test Setup Digital Camera > 2 Megapixel...electromagnetic environment produced by a nuclear weapon consists of the ionization of the atmosphere and generation of an EMP. The gamma rays, neutrons , beta...Measurements . Measurements of each illumination will be made using an Electric Flux Density per unit time (D-dot) probes, so that the magnitude of
The law of electromagnetic induction
V.J. Kutkovetskyy
2014-09-01
Full Text Available Mathematical models of the electromagnetic induction law which do not take into account Faraday’s restrictions are not in full accordance with the physical phenomenon and so they are not laws. Their incomplete correspondence with real devices results in such "paradoxes" as unlimited magnetic field of unipolar generators, infinite sizes of inductors for DC and AC machines modeled, and so on.
Palenzuela, Carlos; Yoshida, Shin
2009-01-01
In addition to producing loud gravitational waves (GW), the dynamics of a binary black hole system could induce emission of electromagnetic (EM) radiation by affecting the behavior of plasmas and electromagnetic fields in their vicinity. We here study how the electromagnetic fields are affected by a pair of orbiting black holes through the merger. In particular, we show how the binary's dynamics induce a variability in possible electromagnetically induced emissions as well as an enhancement of electromagnetic fields during the late-merge and merger epochs. These time dependent features will likely leave their imprint in processes generating detectable emissions and can be exploited in the detection of electromagnetic counterparts of gravitational waves.
Electromagnetically Induced Transparency in an Optomechanical System
SHU Jing
2011-01-01
We demonstrate a form of induced transparency enabled by the large gradient force between one optical and two mechanical modes. We tune the frequency of the mechanical Happing mode into resonance with the mechanical breathing mode to obtain the internal mechanical coupling. Compared with all-photonic physical systems, the quantum optomechanical system exhibits a significantly longer lifetime.%School of Electronic and Optical Engineering,Nanjing University of Science and Technology,Nanjing 210094 We demonstrate a form of induced transparency enabled by the large gradient force between one optical and two mechanical modes.We tune the frequency of the mechanical flapping mode into resonance with the mechanical breathing mode to obtain the internal mechanical coupling.Compared with all-photonic physical systems,the quantum optomechanical system exhibits a significantly longer lifetime.Electromagnetically induced transparency (EIT),which is based on destructive quantum interference,is an interesting phenomenon where a control laser induces a narrow spectral transparency window for a weak probe laser beam.When this generic EIT effect was first observed in an atomic gas,[1] its relevance in non-linear optics and optical (quantum) information processing was quickly recognized.In particular,the rapid variation of the refractive index concomitant with the opening of the transparency window gives rise to a dramatic reduction of the group velocity of a propagating optical pulse.[2,3
Electromagnetic drive system of robotic fish
ZHU Hong-xiu; SUN Nai-di; YUE Yao-hui; DENG Jing; LI Fei-hang; GU Yue; JIA Rui-qing
2012-01-01
With the aim to apply the electric fish into practice to assist coal mine water disaster life detection and rescue work,based on the analysis on swing propulsion movements of tail fin,this paper integrates the electromagnet technology with tail fin drive system by analyzing how the fish swims with tail fin under the law of progression.The principle,structure,and drive signals of tail fin electromagnetic drive are researched,the enforced situation of fish under electromagnetic driving modes are analyzed,and the experimental plat-form of tail fin electromagnetic drive is established.The best distance between electromagnet and armature,which can realize the swing of tail fin,was researched in the experiment under water.The robotic fish structure parameters of tail fin electromagnetic drive was finalized by theoretical analysis and experimental measurement.
Sensing Random Electromagnetic Fields and Applications
2015-06-23
AFRL-OSR-VA-TR-2015-0172 SENSING RANDOM ELECTROMAGNETIC FIELDS AND APPLICATIONS Aristide Dogariu UNIVERSITY OF CENTRAL FLORIDA Final Report 06/23... Electromagnetic Fields and Applications 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK...14. ABSTRACT Random electromagnetic fields (REF) exist in all forms and one common origin is a result of the interaction of coherent fields with
Electromagnet and switchboard for slewing crane
2006-01-01
This paper presents an electromagnet and a switchboard used on a science fair slewing crane described in a separate paper. The electromagnet can lift 50kg loads. The switchboard includes a transformer that powers the electromagnet. It also contains relays, contactors and inverters that allow the operation of the crane three-phase motors using a single-phase power supply. Crane slewing is limited to an 180º angle, for safety reasons. Pressing an emergency button switches off all command circui...
Communication between osteoblasts stimulated by electromagnetic fields
ZHANG JianBao; ZHANG XiaoJun
2007-01-01
Pulsed electromagnetic field can affect the proliferation of osteoblasts, but the mechanism is obscure yet. The communication between osteoblasts, isolated from calvaria bone of newborn SD rats and stimulated with the rectangular electromagnetic field of 15 Hz and 4 mT, was studied. Our results showed that the osteoblasts radiated a kind of light after they were stimulated with the electromagnetic field and it is the light that promotes the proliferation of un-stimulated osteoblasts.
New electromagnetic memories and soft photon theorems
Mao, Pujian; Ouyang, Hao; Wu, Jun-Bao; Wu, Xiaoning
2017-06-01
In this paper, we present a new type of electromagnetic memory. It is a "magnetic" type, or B mode, radiation memory effect. Rather than a residual velocity, we find a position displacement of a charged particle induced by the B mode radiation with memory. We find two types of electromagnetic displacement (ordinary and null). We also show that the null electromagnetic memory formulas are nothing but a Fourier transformation of soft photon theorems.
Wireless Phones Electromagnetic Field Radiation Exposure Assessment
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...
Electromagnetic wave analogue of electronic diode
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 ...
Homology in Electromagnetic Boundary Value Problems
Matti Pellikka
2010-01-01
Full Text Available We discuss how homology computation can be exploited in computational electromagnetism. We represent various cellular mesh reduction techniques, which enable the computation of generators of homology spaces in an acceptable time. Furthermore, we show how the generators can be used for setting up and analysis of an electromagnetic boundary value problem. The aim is to provide a rationale for homology computation in electromagnetic modeling software.
The finite element method in electromagnetics
Jin, Jianming
2014-01-01
A new edition of the leading textbook on the finite element method, incorporating major advancements and further applications in the field of electromagnetics The finite element method (FEM) is a powerful simulation technique used to solve boundary-value problems in a variety of engineering circumstances. It has been widely used for analysis of electromagnetic fields in antennas, radar scattering, RF and microwave engineering, high-speed/high-frequency circuits, wireless communication, electromagnetic compatibility, photonics, remote sensing, biomedical engineering, and space exploration. The
[Electromagnetic field intolerance: a nonexistent disease?].
Safářová, Sárka
2014-01-01
Idiopathic Environmental Intolerance Attributed to Electromagnetic Fields is a relatively new phenomenon, which is not fully understood. Extensive research has been carried out to exclude or confirm out that symptoms reported by sufferers are caused by electromagnetic field. This article describes outcomes of recent experiments and meta-analyses. The article may answer to the question if electromagnetic field does really cause reported symptoms, furthermore, it provides hypothetical explanation of this phenomenon.
Dynamic balancing with rotating radial electromagnetic force
李勇; 陆永平
2004-01-01
A method of producing rotating radial electromagnetic force with a separable structure is proposed,and an experimental model was designed on which open loop vibration control experiments were carried out. Experimental results prove that the electromagnetic force designed has a constant magnitude and an uniform speed,and the idea of using an electromagnetic force as an active control in automatic balancing is correct in principle,and practicable in engineering.
Electromagnetic wave analogue of electronic diode
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 ...
Advanced computational electromagnetic methods and applications
Li, Wenxing; Elsherbeni, Atef; Rahmat-Samii, Yahya
2015-01-01
This new resource covers the latest developments in computational electromagnetic methods, with emphasis on cutting-edge applications. This book is designed to extend existing literature to the latest development in computational electromagnetic methods, which are of interest to readers in both academic and industrial areas. The topics include advanced techniques in MoM, FEM and FDTD, spectral domain method, GPU and Phi hardware acceleration, metamaterials, frequency and time domain integral equations, and statistics methods in bio-electromagnetics.
Optical gas imaging (OGI) cameras have the unique ability to exploit the electromagnetic properties of fugitive chemical vapors to make invisible gases visible. This ability is extremely useful for industrial facilities trying to mitigate product losses from escaping gas and fac...
Podolsky electromagnetism and a modification in Stefan-Boltzmann law
Bonin, Carlos Alberto; Bufalo, Rodrigo Santos; Escobar, Bruto Max Pimentel; Zambrano, German Enrique Ramos [Instituto de Fisica Teorica (IFT/UNESP), Sao Paulo, SP (Brazil)
2009-07-01
Full text. As it is well-known, gauge fields that emerge from the gauge principle are massless vector fields. Considering the photon as a Proca particle, experience sets an upper limit on its mass. This limit is m{sub Proca} < 6X10{sup -17}eV (PDG 2006). However, a mass term, regardless how small, breaks the gauge symmetry. Nevertheless, there exists a theory in which is possible to introduce a mass term preserving all symmetries of Maxwell electromagnetism, including the gauge one: such theory is known as Podolsky Electromagnetism. Podolsky theory is a second- order-derivative theory and has some remarkable properties, despite those already mentioned: the theory has two sectors, a massive one and massless one, it depends on a free parameter (which happens to be the mass of the massive sector) that, like all other elementary particles's masses of the Standard Model, must be fixed through experiences, and the fact that the electrostatic potential is finite everywhere, including over a punctual charge. Just like Maxwell electromagnetism, Podolsky's is a constrained theory and, since it is of second order in the derivatives, it consists in a much richer theoretical structure. Therefore, from both, theoretical and experimental points of view, Podolsky electromagnetism is a very attractive theory. In this work we study a gas of Podolsky photons at finite temperature through path integration. We show that the massless sector leads to the famous Planck's law for black-body radiation and, therefore, to the Stefan-Boltzmann law. We also show that the massive sector of the Podolsky theory induces a modification in both these laws. It is possible to set limits on the Podolsky parameter through comparison of our results with data from cosmic microwave background radiation. (author)
Electromagnetic perturbations in new brane world scenarios
Molina, C; Torrejon, T E M
2016-01-01
In this work we consider electromagnetic dynamics in Randall-Sundrum branes. It is derived a family of four-dimensional spacetimes compatible with Randall-Sundrum brane worlds, focusing on asymptotic flat backgrounds. Maximal extensions of the solutions are constructed and their causal structures are discussed. These spacetimes include singular, non-singular and extreme black holes. Maxwell's electromagnetic field is introduced and its evolution is studied in an extensive numerical survey. Electromagnetic quasinormal mode spectra are derived and analyzed with time-dependent and high order WKB methods. Our results indicate that the black holes in the brane are electromagnetically stable.
electromagnetic radiation exposure from cellular base station
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2DEPARTMENT OF ELECTRICAL/ELECTRONIC ENGINEERING, FEDERAL UNIVERSITY OF TECHNOLOGY, MINNA, ... electronic apparatus radiate electromagnetic energy ..... [11] Randerson, James, “Research fails to detect short-.
Isogeometric analysis and shape optimization in electromagnetism
Nguyen, Dang Manh
In this thesis a recently proposed numerical method for solving partial differential equations, isogeometric analysis (IGA), is utilized for the purpose of shape optimization, with a particular emphasis on applications to two-dimensional design problems arising in electromagnetic applications...... parametrization are combined into an iterative algorithm for shape optimization of two dimensional electromagnetic problems. The algorithm may also be relevant for problems in other engineering disciplines. Using the methods developed in this thesis, remarkably we have obtained antennas that perform one million...... times better than an earlier topology optimization result. This shows a great potential of shape optimization using IGA in the area of electromagnetic antenna design in particular, and for electromagnetic...
Hypothesis on how to measure electromagnetic hypersensitivity.
Tuengler, Andreas; von Klitzing, Lebrecht
2013-09-01
Electromagnetic hypersensitivity (EHS) is an ill-defined term to describe the fact that people who experience health symptoms in the vicinity of electromagnetic fields (EMFs) regard them as causal for their complaints. Up to now most scientists assume a psychological cause for the suffering of electromagnetic hypersensitive individuals. This paper addresses reasons why most provocation studies could not find any association between EMF exposure and EHS and presents a hypothesis on diagnosis and differentiation of this condition. Simultaneous recordings of heart rate variability, microcirculation and electric skin potentials are used for classification of EHS. Thus, it could be possible to distinguish "genuine" electromagnetic hypersensitive individuals from those who suffer from other conditions.
Electromagnetic Theory for Microwaves and Optoelectronics
Zhang, Keqian
2007-01-01
This book is a first year graduate text on electromagnetic fields and waves. At the same time it serves as a useful reference for researchers and engineers in the areas of microwaves and optoelectronics. Following the presentation of the physical and mathematical foundations of electromagnetic theory, the book discusses the field analysis of electromagnetic waves confined in material boundaries, or so-called guided waves, electromagnetic waves in the dispersive media and anisotropic media, Gaussian beams and scalar diffraction theory. The theories and methods presented in the book are foundations of wireless engineering, microwave and millimeter wave techniques, optoelectronics and optical fiber communication.
Integral methods in low-frequency electromagnetics
Solin, Pavel; Karban, Pavel; Ulrych, Bohus
2009-01-01
A modern presentation of integral methods in low-frequency electromagnetics This book provides state-of-the-art knowledge on integral methods in low-frequency electromagnetics. Blending theory with numerous examples, it introduces key aspects of the integral methods used in engineering as a powerful alternative to PDE-based models. Readers will get complete coverage of: The electromagnetic field and its basic characteristics An overview of solution methods Solutions of electromagnetic fields by integral expressions Integral and integrodifferential methods
Visualization Of Electromagnetic Environment Near GSM Antennae
Zvezdina, M. Yu; Shokova, Yu A.; Kundryukova, N. I.; Kutukova, V. D.; Pozdnyakova, A. V.
2017-01-01
Web-enabled mobile phone enhancement has determined a sharp increase of mobile base station quantity, which has led to a surge of electromagnetic noise in metropolitan areas. Electromagnetic noise permanently influences adult and child population; the impossibility to remove this impact has promoted the electromagnetic monitoring. The most accessible form of socially oriented monitoring is a visualization of energy flux density for GSM base station antennae. Forecast calculation routines take antenna construction and location into an account; they also allow giving the recommendations on electromagnetic environment improvement basing on physical interpretation the obtained results.
... problems with gas if you: Are lactose or gluten intolerant Eat a diet rich in fruits, vegetables, whole grains and legumes Drink carbonated beverages Have a chronic intestinal condition, such as irritable bowel syndrome or inflammatory bowel disease Neither age nor sex ...
Electromagnetic wave propagation in a random distribution of C{sub 60} molecules
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.
Nakanishi, Toshihiro; Tamayama, Yasuhiro; Kitano, Masao
2013-01-01
We propose a method for dynamically controlling the properties of a metamaterial that mimics electromagnetically induced transparency (EIT) by introducing varactor diodes to manipulate the structural symmetry of the metamaterial. Dynamic modulation of the EIT property enables the storage and retrieval of electromagnetic waves. We confirmed that the electromagnetic waves were stored and released, while maintaining the phase distribution in the propagating direction.
Continuum mechanics of electromagnetic solids
Maugin, GA
1988-01-01
This volume is a rigorous cross-disciplinary theoretical treatment of electromechanical and magnetomechanical interactions in elastic solids. Using the modern style of continuum thermomechanics (but without excessive formalism) it starts from basic principles of mechanics and electromagnetism, and goes on to unify these two fields in a common framework. It treats linear and nonlinear static and dynamic problems in a variety of elastic solids such as piezoelectrics, electricity conductors, ferromagnets, ferroelectrics, ionic crystals and ceramics. Chapters 1-3 are introductory, describing the e
Electromagnetism in nonleptonic weak interactions
Ecker, G. E-mail: ecker@doppler.thp.univie.ac.at; Isidori, G.; Mueller, G.; Neufeld, H.; Pich, A
2000-12-18
We construct a low-energy effective field theory that permits the complete treatment of isospin-breaking effects in nonleptonic weak interactions to next-to-leading order. To this end, we enlarge the chiral Lagrangian describing strong and {delta}S=1 weak interactions by including electromagnetic terms with the photon as additional dynamical degree of freedom. The complete and minimal list of local terms at next-to-leading order is given. We perform the one-loop renormalization at the level of the generating functional and specialize to K{yields}{pi}{pi} decays.
Electromagnetic Excitation of Nucleon Resonances
Tiator, L; Kamalov, S S; Vanderhaeghen, M
2011-01-01
Recent progress on the extraction of electromagnetic properties of nucleon resonance excitation through pion photo- and electroproduction is reviewed. Cross section data measured at MAMI, ELSA, and CEBAF are analyzed and compared to the analysis of other groups. On this basis, we derive longitudinal and transverse transition form factors for most of the four-star nucleon resonances. Furthermore, we discuss how the transition form factors can be used to obtain empirical transverse charge densities. Contour plots of the thus derived densities are shown for the Delta, Roper, S11, and D13 nucleon resonances.
Plasma scattering of electromagnetic radiation
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
2008+ solved problems in electromagnetics
Nasar, Syed
2007-01-01
SciTech Publishing is reissuing this extremely valuable learning resource, originally published in 1992 in the Schaum's Problem-Solving Series for students of electromagnetics and those who wish to refresh and solidify their understanding of its challenging applications. Problem-solving drill helps develop confidence, but few textbooks offer the answers, never mind the complete solutions, to their chapter exercises. Here noted author Professor Syed Nasar has divided the book's problems into topic areas similar to a textbook and presented a wide array of problems, followed immediately by their
Electromagnetic configurations of rail guns
Fat'yanov, O. V.; Ostashev, V. E.; Lopyrev, A. N.; Ul'Yanov, A. V.
1993-06-01
Some problems associated with the electromagnetic acceleration of macrobodies in a rail gun are examined. An approach to the design of rail gun configurations is proposed, and some basic rail gun schemes are synthesized. The alternative rail gun schemes are compared in terms of electrode potential and stability of the electrode gap with respect to parasitic current shunting. The effect of the ohmic resistance of the electrodes and of the additional magnetization field on the spatial structure of the discharge in the rail gun channel is discussed. A classification of rail gun modifications is presented.
Rotational Electromagnetic Energy Harvesting System
Dinulovic, Dragan; Brooks, Michael; Haug, Martin; Petrovic, Tomislav
This paper presents development of the rotational electromagnetic energy harvesting transducer. The transducer is driven mechanically by pushing a button; therefore, the mechanical energy will be converted into electrical energy. The energy harvesting (EH) transducer consists of multilayer planar coils embedded in a PCB, multipolar NdFeB hard magnets, and a mechanical system for movement conversion. The EH transducer generate an energy of about 4 mJ at a load of 10 Ω. The maximum open circuit output voltage is as high as 2 V and the maximum short circuit output current is 800 mA.
Electromagnetic Transmission Through Resonant Structures
Young, Steven M.
Electromagnetic resonators store energy in the form of oscillatory electric and magnetic fields and gradually exchange that energy by coupling with their environment. This coupling process can have profound effects on the transmission and reflection properties of nearby interfaces, with rapid transitions from high transmittance to high reflectance over narrow frequency ranges, and has been exploited to design useful optical components such as spectral filters and dielectric mirrors. This dissertation includes analytic, numeric, and experimental investigations of three different electromagnetic resonators, each based on a different method of confining electromagnetic fields near the region of interest. First, we show that a structure with two parallel conducting plates, each containing a subwavelength slit, supports a localized resonant mode bound to the slits and therefore exhibits (in the absence of nonradiative losses), perfect resonant transmission over a narrow frequency range. In practice, the transmission is limited by conduction losses in the sidewalls; nevertheless, experimental results at 10 GHz show a narrowband transmission enhancement by a factor of 104 compared to the non-resonant transmission, with quality factor (ratio of frequency to peak width) Q ~ 3000. Second, we describe a narrowband transmission filter based on a single-layer dielectric grating. We use a group theory analysis to show that, due to their symmetry, several of the grating modes cannot couple to light at normal incidence, while several others have extremely large coupling. We then show how selectively breaking the system symmetry using off-normal light incidence can produce transmission peaks by enabling weak coupling to some of the previously protected modes. The narrowband filtering capabilities are validated by an experimental demonstration in the long wavelength infrared, showing transmission peaks of quality factor Q ~ 100 within a free-spectral range of 8-15 mum. Third, we
Electromagnetic fields, environment and health
Perrin, Anne
2013-01-01
A good number of false ideas are circulating on the effects of non-ionizing radiations on our health, which can lead to an oversimplification of the issue, to potentially dangerous misconceptions or to misleading data analysis. Health effects may be exaggerated, or on the contrary underplayed. The authors of this work (doctors, engineers and researchers) have endeavored to supply validated and easily understandable scientific information on the electromagnetic fields and their biological and health effects. After a general review of the physics of the waves and a presentation of non-ionizing r
Sparse Reconstruction Schemes for Nonlinear Electromagnetic Imaging
Desmal, Abdulla
2016-03-01
Electromagnetic imaging is the problem of determining material properties from scattered fields measured away from the domain under investigation. Solving this inverse problem is a challenging task because (i) it is ill-posed due to the presence of (smoothing) integral operators used in the representation of scattered fields in terms of material properties, and scattered fields are obtained at a finite set of points through noisy measurements; and (ii) it is nonlinear simply due the fact that scattered fields are nonlinear functions of the material properties. The work described in this thesis tackles the ill-posedness of the electromagnetic imaging problem using sparsity-based regularization techniques, which assume that the scatterer(s) occupy only a small fraction of the investigation domain. More specifically, four novel imaging methods are formulated and implemented. (i) Sparsity-regularized Born iterative method iteratively linearizes the nonlinear inverse scattering problem and each linear problem is regularized using an improved iterative shrinkage algorithm enforcing the sparsity constraint. (ii) Sparsity-regularized nonlinear inexact Newton method calls for the solution of a linear system involving the Frechet derivative matrix of the forward scattering operator at every iteration step. For faster convergence, the solution of this matrix system is regularized under the sparsity constraint and preconditioned by leveling the matrix singular values. (iii) Sparsity-regularized nonlinear Tikhonov method directly solves the nonlinear minimization problem using Landweber iterations, where a thresholding function is applied at every iteration step to enforce the sparsity constraint. (iv) This last scheme is accelerated using a projected steepest descent method when it is applied to three-dimensional investigation domains. Projection replaces the thresholding operation and enforces the sparsity constraint. Numerical experiments, which are carried out using
Energetic constraints on electromagnetic signals from double black hole mergers
Dai, Lixin; McKinney, Jonathan C.; Miller, M. Coleman
2017-09-01
The possible Fermi detection of an electromagnetic counterpart to the double black hole merger GW150914 has inspired many theoretical models, some of which propose that the holes spiralled together inside a massive star. However, we show that the heat produced by the dynamical friction on such black hole orbits can exceed the stellar binding energy by a large factor, which means that this heat could destroy the star. The energy scale of the explosion and the terminal velocity of the gas can be much larger than those in conventional supernovae. If the star unbinds before the merger, it would be hard for enough gas to remain near the holes at the merger to produce a gamma-ray burst, and this consideration should be taken into account when models are proposed for electromagnetic counterparts to the coalescence of two stellar-mass black holes. We find that only when the two black holes form very close to the centre can the star certainly avoid destruction. In that case, dynamical friction can make the black holes coalesce faster than they would in vacuum, which leads to a modification of the gravitational waveform that is potentially observable by advanced LIGO.
Kim, Chang Hwan; Lee, Don Bae
1999-02-15
This book gives descriptions of vector analysis on vector algebra and vector double, coulomb's law, electric intensity, Gauss theory and Gauss divergence theorem, the avant-garde and a potential difference, conductor in vacuum, a dielectric and capacitance like dielectric and polarization, equation of poisson and Laplace, coulomb's law, property of a magnetic substance, magnetic attraction of current, magnetic circuit, inductance and application of a magnetic field, Faraday's law and Maxwell equation, plane wave and transmission cable.
2012-03-07
are adversely affected by atmospheric turbulence, which induces intensity fluctuations ( scintillations ). Laser beam distorted by turbulence „Heat...unlimited. Scintillation vs. # of Beamlets Scintillation reaches its minimum possible value with only four beamlets! Evidently four beamlets is...for Ultrafast Carrier Scattering in Semiconductors ” 1. Model IR amplifier for extremely weak signals and distant targets Dr. Analee Miranda
Electromagnets 1: Turn on the Power. Science in a Box.
Whitman, Betsy Blizard
1992-01-01
The article presents inexpensive activities to teach elementary school students about electromagnets. Students learn to make an electromagnet with a battery, nail, and wire, then different activities help them explore the difference between permanent magnets and electromagnets. (SM)
Compton Sources of Electromagnetic Radiation
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.
Electromagnetic wave energy conversion research
Bailey, R. L.; Callahan, P. S.
1975-01-01
Known electromagnetic wave absorbing structures found in nature were first studied for clues of how one might later design large area man-made radiant-electric converters. This led to the study of the electro-optics of insect dielectric antennae. Insights were achieved into how these antennae probably operate in the infrared 7-14um range. EWEC theoretical models and relevant cases were concisely formulated and justified for metal and dielectric absorber materials. Finding the electromagnetic field solutions to these models is a problem not yet solved. A rough estimate of losses in metal, solid dielectric, and hollow dielectric waveguides indicates future radiant-electric EWEC research should aim toward dielectric materials for maximum conversion efficiency. It was also found that the absorber bandwidth is a theoretical limitation on radiant-electric conversion efficiency. Ideally, the absorbers' wavelength would be centered on the irradiating spectrum and have the same bandwith as the irradiating wave. The EWEC concept appears to have a valid scientific basis, but considerable more research is needed before it is thoroughly understood, especially for the complex randomly polarized, wide band, phase incoherent spectrum of the sun. Specific recommended research areas are identified.
Millimeter waves: acoustic and electromagnetic.
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.
Electromagnetic probes of the QGP
Bratkovskaya E. L.
2015-01-01
Full Text Available We investigate the properties of the QCD matter across the deconfinement phase transition in the scope of the parton-hadron string dynamics (PHSD transport approach. We present here in particular the results on the electromagnetic radiation, i.e. photon and dilepton production, in relativistic heavy-ion collisions. By comparing our calculations for the heavy-ion collisions to the available data, we determine the relative importance of the various production sources and address the possible origin of the observed strong elliptic flow v2 of direct photons. We argue that the different centrality dependence of the hadronic and partonic sources for direct photon production in nucleusnucleus collisions can be employed to shed some more light on the origin of the photon v2 “puzzle”. While the dilepton spectra at low invariant mass show in-medium effects like an enhancement from multiple baryonic resonance formation or a collisional broadening of the vector meson spectral functions, the dilepton yield at high invariant masses (above 1.1 GeV is dominated by QGP contributions for central heavy-ion collisions at ultra-relativistic energies. This allows to have an independent view on the parton dynamics via their electromagnetic massive radiation.
Quantization of Electromagnetic Fields in Cavities
Kakazu, Kiyotaka; Oshiro, Kazunori
1996-01-01
A quantization procedure for the electromagnetic field in a rectangular cavity with perfect conductor walls is presented, where a decomposition formula of the field plays an essential role. All vector mode functions are obtained by using the decomposition. After expanding the field in terms of the vector mode functions, we get the quantized electromagnetic Hamiltonian.
ELECTROMAGNETIC APPARATUS FOR MOVING A ROD
Young, J.N.
1957-08-20
An electromagnetic device for moving an object in a linear path by increments is described. The device is specifically adapted for moving a neutron absorbing control rod into and out of the core of a reactor and consists essentially of an extension member made of magnetic material connected to one end of the control rod and mechanically flexible to grip the walls of a sleeve member when flexed, a magnetic sleeve member coaxial with and slidable between limit stops along the flexible extension, electromagnetic coils substantially centrally located with respect to the flexible extension to flex the extension member into gripping engagement with the sleeve member when ener gized, moving electromagnets at each end of the sleeve to attract the sleeve when energized, and a second gripping electromagnet positioned along the flexible extension at a distance from the previously mentioned electromagnets for gripping the extension member when energized. In use, the second gripping electromagnet is deenergized, the first gripping electromagnet is energized to fix the extension member in the sleeve, and one of the moving electromagnets is energized to attract the sleeve member toward it, thereby moving the control rod.
Electromagnetic Radiation Originating from Unstable Electron Oscillations
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....
Linear electromagnetic wave equations in materials
Starke, R.; Schober, G. A. H.
2017-09-01
After a short review of microscopic electrodynamics in materials, we investigate the relation of the microscopic dielectric tensor to the current response tensor and to the full electromagnetic Green function. Subsequently, we give a systematic overview of microscopic electromagnetic wave equations in materials, which can be formulated in terms of the microscopic dielectric tensor.
International Conference on Microelectronics, Electromagnetics and Telecommunications
Rao, N; Kumar, S; Raj, C; Rao, V; Sarma, G
2016-01-01
This volume contains 73 papers presented at ICMEET 2015: International Conference on Microelectronics, Electromagnetics and Telecommunications. The conference was held during 18 – 19 December, 2015 at Department of Electronics and Communication Engineering, GITAM Institute of Technology, GITAM University, Visakhapatnam, INDIA. This volume contains papers mainly focused on Antennas, Electromagnetics, Telecommunication Engineering and Low Power VLSI Design.
Project Physics Tests 4, Light and Electromagnetism.
Harvard Univ., Cambridge, MA. Harvard Project Physics.
Test items relating to Project Physics Unit 4 are presented in this booklet. Included are 70 multiple-choice and 22 problem-and-essay questions. Concepts of light and electromagnetism are examined on charges, reflection, electrostatic forces, electric potential, speed of light, electromagnetic waves and radiations, Oersted's and Faraday's work,…
The Teaching of Electromagnetism at University Level
Houldin, J. E.
1974-01-01
Discusses different kinds of material presentation in the teaching of electromagnetism at the university level, including three "classical" approaches and the Keller personalized proctorial system. Indicates that a general introduction to generators and motors may be useful in an electromagnetism course. (CC)
Upper High School Students' Understanding of Electromagnetism
Saglam, Murat; Millar, Robin
2006-01-01
Although electromagnetism is an important component of upper secondary school physics syllabuses in many countries, there has been relatively little research on students' understanding of the topic. A written test consisting of 16 diagnostic questions was developed and used to survey the understanding of electromagnetism of upper secondary school…
Computational Techniques of Electromagnetic Dosimetry for Humans
Hirata, Akimasa; Fujiwara, Osamu
There has been increasing public concern about the adverse health effects of human exposure to electromagnetic fields. This paper reviews the rationale of international safety guidelines for human protection against electromagnetic fields. Then, this paper also presents computational techniques to conduct dosimetry in anatomically-based human body models. Computational examples and remaining problems are also described briefly.
Electrodynamics in deformable solids for electromagnetic forming
Motoasca, T.E.
2003-01-01
The behaviour of matter in an electromagnetic field may be considered as a very complex problem, involving not only electromagnetism but also mechanics and thermodynamics. The interaction field-matter is not simple even for a rigid body, and it becomes more complicated for a deforming body, as long
Unification of Electromagnetic Interactions and Gravitational Interactions
WUNing
2002-01-01
Unified theory of gravitational interactions and electromagnetic interactions is discussed in this paper.Based on gauge principle,electromagnetic interactions and gravitational interactions are formulated in the same manner and are unified in a semi-direct product group of U(1) Abelian gauge group and gravitational gauge group.
Unification of Electromagnetic Interactions and Gravitational Interactions
WU Ning
2002-01-01
Unified theory of gravitational interactions and electromagnetic interactions is discussed in this paper.Based on gauge principle, electromagnetic interactions and gravitational interactions are formulated in the same mannerand are unified in a semi-direct product group of U(1) Abelian gauge group and gravitational gauge group.
Solitary Waves in Relativistic Electromagnetic Plasma
XIE Bai-Song; HUA Cun-Cai
2005-01-01
Solitary waves in relativistic electromagnetic plasmas are obtained numerically. The longitudinal momentum of electrons has been taken into account in the problem. It is found that in the moving frame with electromagnetic field propagating the solitary waves can exist in both cases, where the vector potential frequency is larger or smaller than the plasma characteristic frequency.
[Mechanisms of electromagnetic radiation damaging male reproduction].
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.
Electromagnetic corrections to light hadron masses
Portelli, A; Fodor, Z; Frison, J; Hölbling, C; Katz, S D; Krieg, S; Kurth, T; Lellouch, L; Lippert, T; Szabó, K K; Ramos, A
2010-01-01
At the precision reached in current lattice QCD calculations, electromagnetic effects are becoming numerically relevant. We will present preliminary results for electromagnetic corrections to light hadron masses, based on simulations in which a $\\mathrm{U}(1)$ degree of freedom is superimposed on $N_f=2+1$ QCD configurations from the BMW collaboration.
Luebke, Ryan
2015-01-22
A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.
Solidification of Al alloys under electromagnetic field
崔建忠
2003-01-01
New theories and technology in the electromagnetic field were put forward about DC casting of Al alloys, including the fundamental research works, I.e, effects of the electromagnetic field on solidus and liquidus, macrosegregation of the main alloying elements, microstructures, content of alloying elements in grains and grain size after solidification under electromagnetic field, and also including a new process-DC casting under low frequency electromagnetic field(LFEMC), which can refine microstructure, eliminate macrosegregation, increase the content of alloying elements within grains, decrease the residual stress, avoid cracks and improve surface quality, and another new process-DC casting under low frequency electromagnetic vibration(LFEVC), which is a high effective method for grain refining.
Limits on new forces coexisting with electromagnetism
Kloor, H.; Fischbach, E.; Talmadge, C. (Physics Department, Purdue University, West Lafayette, Indiana 47907 (United States)); Greene, G.L. (National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States))
1994-02-15
We consider the limits arising from different electromagnetic systems on the existence of a possible new electromagnetic analogue of the fifth force. Although such a force may have no intrinsic connection to electromagnetism (or gravity), its effects could be manifested through various anomalies in electromagnetic systems, for appropriate values of the coupling strength and range. Our work generalizes that of Bartlett and Loegl (who considered the case of a massive vector field coexisting with massless electrodynamics) to encompass a broad class of phenomenological interactions mediated by both scalar and vector exchanges. By combining data from both gravitational and electromagnetic systems, one can eventually set limits on a new force whose range [lambda] extends from the subatomic scale ([lambda][approx]10[sup [minus]15] m) to the astrophysical scale ([lambda][approx]10[sup 12] m).
Controlling electromagnetic scattering with wire metamaterial resonators
Filonov, Dmitry S; Iorsh, Ivan; Belov, Pavel A; Ginzburg, Pavel
2016-01-01
Manipulation of radiation is required for enabling a span of electromagnetic applications. Since properties of antennas and scatterers are very sensitive to a surrounding environment, macroscopic artificially created materials are good candidates for shaping their characteristics. In particular, metamaterials enable controlling both dispersion and density of electromagnetic states, available for scattering from an object. As the result, properly designed electromagnetic environment could govern waves' phenomena. Here electromagnetic properties of scattering dipoles, situated inside a wire medium (metamaterial) are analyzed both numerically and experimentally. Impact of the metamaterial geometry, dipole arrangement inside the medium, and frequency of the incident radiation on scattering phenomena was studied. It was shown that the resonance of the dipole hybridizes with Fabry-Perot modes of the metamaterial, giving rise to a complete reshaping of electromagnetic properties. Regimes of controlled scattering sup...
Electromagnetic-Magnetoelectric Duality for Waveguides
Sang-Nourpour, Nafiseh; Kheradmand, R; Rezaei, M; Sanders, Barry C
2015-01-01
We develop a theory for waveguides that respects the duality of electromagnetism, namely the symmetry of the equations arising through inclusion of magnetic monopoles in addition to including electrons (electric monopoles). The term magnetoelectric potential is sometimes used to signify the magnetic-monopole induced dual to the usual electromagnetic potential. To this end, we introduce a general theory for describing modes and characteristics of waveguides based on mixed-monopole materials, with both electric and magnetic responses. Our theory accommodates exotic media such as double-negative, near-zero and zero-index materials, and we demonstrate that our general theory exhibits the electromagnetic duality that would arise if we were to incorporate magnetic monopoles into the media. We consider linear, homogeneous, isotropic waveguide materials with slab and cylindrical geometries. To ensure manifest electromagnetic duality, we construct generic electromagnetic susceptibilities that are dual in both electric...
Electromagnetic Interference on Large Wind Turbines
Florian Krug
2009-11-01
Full Text Available Electromagnetic interference (EMI can both affect and be transmitted by mega-watt wind turbines. This paper provides a general overview on EMI with respect to mega-watt wind turbines. Possibilities of measuring all types of electromagnetic interference are shown. Electromagnetic fields resulting from a GSM transmitter mounted on a mega-watt wind turbine will be analyzed in detail. This cellular system operates as a real-time communication link. The method-of-moments is used to analytically describe the electro-magnetic fields. The electromagnetic interference will be analyzed under the given boundary condition with a commercial simulation tool. Different transmitter positions are judged on the basis of their radiation patterns. The principal EMI mechanisms are described and taken into consideration.
Optimization and inverse problems in electromagnetism
Wiak, Sławomir
2003-01-01
From 12 to 14 September 2002, the Academy of Humanities and Economics (AHE) hosted the workshop "Optimization and Inverse Problems in Electromagnetism". After this bi-annual event, a large number of papers were assembled and combined in this book. During the workshop recent developments and applications in optimization and inverse methodologies for electromagnetic fields were discussed. The contributions selected for the present volume cover a wide spectrum of inverse and optimal electromagnetic methodologies, ranging from theoretical to practical applications. A number of new optimal and inverse methodologies were proposed. There are contributions related to dedicated software. Optimization and Inverse Problems in Electromagnetism consists of three thematic chapters, covering: -General papers (survey of specific aspects of optimization and inverse problems in electromagnetism), -Methodologies, -Industrial Applications. The book can be useful to students of electrical and electronics engineering, computer sci...
Spheroidal Wave Functions in Electromagnetic Theory
Li, Le-Wei; Kang, Xiao-Kang; Leong, Mook-Seng
2001-11-01
The flagship monograph addressing the spheroidal wave function and its pertinence to computational electromagnetics Spheroidal Wave Functions in Electromagnetic Theory presents in detail the theory of spheroidal wave functions, its applications to the analysis of electromagnetic fields in various spheroidal structures, and provides comprehensive programming codes for those computations. The topics covered in this monograph include: Spheroidal coordinates and wave functions Dyadic Green's functions in spheroidal systems EM scattering by a conducting spheroid EM scattering by a coated dielectric spheroid Spheroid antennas SAR distributions in a spheroidal head model The programming codes and their applications are provided online and are written in Mathematica 3.0 or 4.0. Readers can also develop their own codes according to the theory or routine described in the book to find subsequent solutions of complicated structures. Spheroidal Wave Functions in Electromagnetic Theory is a fundamental reference for scientists, engineers, and graduate students practicing modern computational electromagnetics or applied physics.
Electromagnetic anomaly before earthquakes measured by electromagnetic experiments
Guoze Zhao; Yan Zhan; Lifeng Wang; Jijun Wang; Ji Tang; Qibin Xiao; Xiaobin Chen
2009-01-01
Three experiments are carried out for earthquake monitoring using electromagnetic (EM) methods in recent years. Some earthquakes occurred in chance of the measurement time period for each experiment and the anomalies were recorded before the shocks. The observation at a site 20 km away from the epicenter of Zhangbei Ms6.2 earthquake in 1998 shows that the apparent resistivity decreases in the strike direction before and/or during the earthquake and the resistivity increases in the de-cline direction. This anomalous variation in apparent resistivity accounts for about 20%. The apparent resistivities at a site in the epicentrai area decrease in the strike and decline directions before and/or during the earthquake and increase after shocks. The experiments using artificial electromagnetic signals with super low frequency carried out in 1999 show that the resolution and stability of electric and magnetic spectra are improved. The spectra of electric and magnetic fields and apparent resistivity at the Baodi station began to anomalously change two days before the Qian'an earthquake with 120 km distant to the station. The anomalous variation of electric and magnetic spectra is about twice as great as normal variation and the apparent resistivity changes by about 20%. The measurements in active seismic area of Ytmnan province in the year 2005 indicate that the electric and magnetic spectra anomalously change by one order before the Taoyuan earthquake about 100 km away from the observa-tories. But the measurements at the sites in Beijing area 2 000 km away from the epicenter do not show any anomaly.
Tag gas capsule with magnetic piercing device
Nelson, Ira V.
1976-06-22
An apparatus for introducing a tag (i.e., identifying) gas into a tubular nuclear fuel element. A sealed capsule containing the tag gas is placed in the plenum in the fuel tube between the fuel and the end cap. A ferromagnetic punch having a penetrating point is slidably mounted in the plenum. By external electro-magnets, the punch may be caused to penetrate a thin rupturable end wall of the capsule and release the tag gas into the fuel element. Preferably the punch is slidably mounted within the capsule, which is in turn loaded as a sealed unit into the fuel element.
Predicting Electromagnetic Signatures of Gravitational Wave Sources
D'Orazio, Daniel John
This dissertation investigates the signatures of electromagnetic radiation that may accompany two specific sources of gravitational radiation: the inspiral and merger of massive black hole binaries (MBHBs) in galactic nuclei, and the coalescence of black hole neutron star (BHNS) pairs. Part I considers the interaction of MBHBs, at sub-pc separations, with a circumbinary gas disk. Accretion rates onto the MBHB are calculated from two-dimensional hydrodynamical simulations as a function of the relative masses of the black holes. The results are applied to interpretation of the recent, sub-pc separation MBHB candidate in the nucleus of the periodically variable Quasar PG 1302-102. We advance an interpretation of the variability observed in PG 1302-102 as being caused by Doppler-boosted emission sourced by the orbital velocity of the smaller black hole in a MBHB with disparate relative masses. Part II considers BHNS binaries in which the black hole is large enough to swallow the neutron star whole before it is disrupted. As the pair nears merger, orbital motion of the black hole through the magnetosphere of the neutron star generates an electromotive force, a black-hole-battery, which, for the strongest neutron star magnetic field strengths, could power luminosities large enough to make the merging pair observable out to cosmic distances. Relativistic solutions for vacuum fields of a magnetic dipole near a horizon are given, and a mechanism for harnessing the power of the black-hole-battery is put forth in the form of a fireball emitting in hard X-rays to gamma-rays.
Spatially dependent electromagnetically induced transparency
Radwell, Neal; Piccirillo, Bruno; Barnett, Stephen M; Franke-Arnold, Sonja
2014-01-01
Recent years have seen vast progress in the generation and detection of structured light, with potential applications in high capacity optical data storage and continuous variable quantum technologies. Here we measure the transmission of structured light through cold rubidium atoms and observe regions of electromagnetically induced transparency (EIT). We use q-plates to generate a probe beam with azimuthally varying phase and polarisation structure, and its right and left circular polarisation components provide the probe and control of an EIT transition. We observe an azimuthal modulation of the absorption profile that is dictated by the phase and polarisation structure of the probe laser. Conventional EIT systems do not exhibit phase sensitivity. We show, however, that a weak transverse magnetic field closes the EIT transitions, thereby generating phase dependent dark states which in turn lead to phase dependent transparency, in agreement with our measurements.
The AMS-02 electromagnetic calorimeter
Cadoux, F.; Cervelli, F.; Chambert-Hermel, V.; Chen, G.; Chen, H.; Coignet, G.; Di Falco, S.; Dubois, J.M.; Falchini, E.; Franzoso, A.; Fougeron, D.; Fouque, N.; Galeotti, S.; Girard, L.; Goy, C.; Hermel, R.; Incagli, M.; Kossakowski, R.; Lieunard, B.; Liu, Y.; Liu, Z.; Lomtadze, T.; Maestro, P.; Marrocchesi, P.S.; Paoletti, R.; Pilo, F. E-mail: federico.pilo@pi.infn.it; Rosier-Lees, S.; Spinella, F.; Turini, N.; Valle, G.; Venanzoni, G.; Vialle, J.P.; Yu, Z.; Zhuang, H
2002-12-01
The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a lead-scintillating fibers sampling calorimeter characterized by high granularity that allows to image the longitudinal and lateral showers development, a key issue to provide high electron/hadron discrimination. The light collection system and the FE electronics are designed to let the calorimeter operate over a wide energy range from few GeV up to 1 TeV. A full-scale prototype of the e.m. calorimeter was tested at CERN in October 2001 using electrons and pions beams with energy ranging from 3 to 100 GeV. Effective sampling thickness, linearity and energy resolution were measured.
The AMS-02 electromagnetic calorimeter
Cadoux, F; Chambert-Hermel, V; Chen, G; Chen, H; Coignet, G; Di Falco, S; Dubois, J M; Falchini, E; Franzoso, A; Fougeron, D; Fouque, N; Galeotti, S; Girard, L; Goy, C; Hermel, R; Incagli, M; Kossakowski, R; Lieunard, B; Liu, Y; Liu, Z; Lomtadze, T A; Maestro, P; Marrocchesi, P S; Paoletti, R; Pilo, F; Rosier-Lees, S; Spinella, F; Turini, N; Valle, G D; Venanzoni, G; Vialle, J P; Yu, Z; Zhuang, H
2002-01-01
The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a lead-scintillating fibers sampling calorimeter characterized by high granularity that allows to image the longitudinal and lateral showers development, a key issue to provide high electron/hadron discrimination. The light collection system and the FE electronics are designed to let the calorimeter operate over a wide energy range from few GeV up to 1 TeV. A full-scale prototype of the e.m. calorimeter was tested at CERN in October 2001 using electrons and pions beams with energy ranging from 3 to 100 GeV. Effective sampling thickness, linearity and energy resolution were measured. (8 refs).
Electromagnetic Angular Momentum and Relativity
Milton, Kimball A
2012-01-01
Recently there have been suggestions that the Lorentz force law is inconsistent with special relativity. This is difficult to understand, since Einstein invented relativity in order to reconcile electrodynamics with mechanics. Here we investigate the momentum of an electric charge and a magnetic dipole in the frame in which both are at rest, and in an infinitesimally boosted frame in which both have a common velocity. We show that for a dipole composed of a magnetic monopole-antimonopole pair the torque is zero in both frames, while if the dipole is a point dipole, the torque is not zero, but is balanced by the rate of change of the angular momentum of the electromagnetic field, so there is no mechanical torque on the dipole.
Electromagnetic field and brain development.
Kaplan, Suleyman; Deniz, Omur Gulsum; Önger, Mehmet Emin; Türkmen, Aysın Pınar; Yurt, Kıymet Kübra; Aydın, Işınsu; Altunkaynak, Berrin Zuhal; Davis, Devra
2016-09-01
Rapid advances in technology involve increased exposures to radio-frequency/microwave radiation from mobile phones and other wireless transmitting devices. As cell phones are held close to the head during talking and often stored next to the reproductive organs, studies are mostly focused on the brain. In fact, more research is especially needed to investigate electromagnetic field (EMF)'s effects on the central nervous system (CNS). Several studies clearly demonstrate that EMF emitted by cell phones could affect a range of body systems and functions. Recent work has demonstrated that EMF inhibit the formation and differentiation of neural stem cells during embryonic development and also affect reproductive and neurological health of adults that have undergone prenatal exposure. The aim of this review is to discuss the developing CNS and explain potential impacts of EMF on this system.
Why does electromagnetism conserve parity
Babu, K.S.; Mohapatra, R.N. (Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742 (USA))
1990-12-01
The assumption of electrical neutrality of the neutrino in the context of the standard model is shown to explain why electromagnetism conserves parity. We then construct an extension of the standard model where the neutrino has a nonzero but tiny charge. Such theories necessarily imply a parity-violating component in QED and nonconservation of electric charge ({Delta}{ital Q}{ne}0). The strengths of the parity-violating component of QED as well as {Delta}{ital Q}{ne}0 interactions are connected to the nonvanishing neutrino charge {ital Q}{sub {nu}} which is shown to be bounded by {ital Q}{sub {nu}}{le}10{sup {minus}28}{ital e} in the context of these models.
Electromagnetism of rotating conductors revisited
Redzic, Dragan V. [Faculty of Physics, University of Belgrade, Belgrade (Yugoslavia)]. E-mail: redzic@ff.bg.ac.yu
2002-03-01
The charge distribution and electromagnetic fields in a rotating, charged conductor under stationary conditions are investigated, assuming that the electrons are at rest relative to the conductor. The basic equations are found, referred to the inertial rest frame of the rotational axis, in the relativistic case, and applied to the case of a cylindrical conductor. The results obtained are compared with those of Groen and Voeyenli (Groen Oe and Voeyenli K 1982 Eur. J. Phys. 3 210-4) who considered the same problem but without taking into account the relative permittivity of the rotating conductor. It is found that the E- and B-fields do not depend on {epsilon}{sub r} and coincide with those calculated by Groen and Voeyenli; the space and surface charge densities, however, depend on {epsilon}{sub r}. (author)
Electromagnetic Duality and Entanglement Anomalies
Donnelly, William; Wall, Aron
2016-01-01
Duality is an indispensable tool for describing the strong-coupling dynamics of gauge theories. However, its actual realization is often quite subtle: quantities such as the partition function can transform covariantly, with degrees of freedom rearranged in a nonlocal fashion. We study this phenomenon in the context of the electromagnetic duality of abelian $p$-forms. A careful calculation of the duality anomaly on an arbitrary $D$-dimensional manifold shows that the effective actions agree exactly in odd $D$, while in even $D$ they differ by a term proportional to the Euler number. Despite this anomaly, the trace of the stress tensor agrees between the dual theories. We also compute the change in the vacuum entanglement entropy under duality, relating this entanglement anomaly to the duality of an "edge mode" theory in two fewer dimensions. Previous work on this subject has led to conflicting results; we explain and resolve these discrepancies.
Electromagnetic launchers for space applications
Schroeder, J. M.; Gully, J. H.; Driga, M. D.
1989-01-01
An electromagnetic launcher (EML) was designed for NASA-Langley to boost large models to hypervelocity for flight evaluation. Two different concepts were developed using railgun and coilgun principles. A coilgun was designed to accelerate a 14-kg mass to 6 km/s and, by adding additional equipment, to accelerate a 10-kg mass to 11 km/s. The railgun system was designed to accelerate only 14 kg to 6 km/s. Of significance in this development is the opportunity to use the launcher for aeroballistic research of the upper atmosphere, eventually placing packages in low earth orbit using a small rocket. The authors describe the railgun and coilgun launch designs and suggest a reconfiguration for placement of 150-kg parcels into low earth orbit for aeroballistic studies and possible space lab support. Each design is detailed along with the performance adjustments which would be required for circular orbit payload placement.
Visualizing electromagnetic vacuum by MRI
Chandrashekar, Chandrika S; Chandrashekar, S; Taylor, Erika A; Taylor, Deanne M
2016-01-01
Based upon Maxwell's equations, it has long been established that oscillating electromagnetic (EM) fields incident upon a metal surface decay exponentially inside the conductor, leading to a virtual EM vacuum at sufficient depths. Magnetic resonance imaging (MRI) utilizes radiofrequency (r.f.) EM fields to produce images. Here we present the first visualization of an EM vacuum inside a bulk metal strip by MRI, amongst several novel findings. We uncover unexpected MRI intensity patterns arising from two orthogonal pairs of faces of a metal strip, and derive formulae for their intensity ratios. Further, we furnish chemical shift imaging (CSI) results that discriminate different faces (surfaces) of a metal block according to their distinct nuclear magnetic resonance (NMR) chemical shifts, which holds much promise for monitoring surface chemical reactions noninvasively. Bulk metals are ubiquitous, and MRI is a premier noninvasive diagnostic tool. Combining the two, the emerging field of bulk metal MRI can be expe...
Formal analysis of electromagnetic optics
Khan-Afshar, Sanaz; Hasan, Osman; Tahar, Sofiène
2014-09-01
Optical systems are increasingly being used in safety-critical applications. Due to the complexity and sensitivity of optical systems, their verification raises many challenges for engineers. Traditionally, the analysis of such systems has been carried out by paper-and-pencil based proofs and numerical computations. However, these techniques cannot provide accurate results due to the risk of human error and inherent approximations of numerical algorithms. In order to overcome these limitations, we propose to use theorem proving (i.e., a computer-based technique that allows to express mathematical expressions and reason about their correctness by taking into account all the details of mathematical reasoning) as a complementary approach to improve optical system analysis. This paper provides a higher-order logic (a language used to express mathematical theories) formalization of electromagnetic optics in the HOL Light theorem prover. In order to demonstrate the practical effectiveness of our approach, we present the analysis of resonant cavity enhanced photonic devices.
ELVIS - ELectromagnetic Vector Information Sensor
Bergman, J E S; Thidé, B; Ananthakrishnan, S; Wahlund, J E; Karlsson, R L; Puccio, W; Carozzi, T D; Kale, P
2005-01-01
The ELVIS instrument was recently proposed by the authors for the Indian Chandrayaan-1 mission to the Moon and is presently under consideration by the Indian Space Research Organisation (ISRO). The scientific objective of ELVIS is to explore the electromagnetic environment of the moon. ELVIS samples the full three-dimensional (3D) electric field vector, E(x,t), up to 18 MHz, with selective Nyqvist frequency bandwidths down to 5 kHz, and one component of the magnetic field vector, B(x,t), from a few Hz up to 100 kHz.As a transient detector, ELVIS is capable of detecting pulses with a minimum pulse width of 5 ns. The instrument comprises three orthogonal electric dipole antennas, one magnetic search coil antenna and a four-channel digital sampling system, utilising flexible digital down conversion and filtering together with state-of-the-art onboard digital signal processing.
Analysis of Nonlinear Electromagnetic Metamaterials
Poutrina, Ekaterina; Smith, David R
2010-01-01
We analyze the properties of a nonlinear metamaterial formed by integrating nonlinear components or materials into the capacitive regions of metamaterial elements. A straightforward homogenization procedure leads to general expressions for the nonlinear susceptibilities of the composite metamaterial medium. The expressions are convenient, as they enable inhomogeneous system of scattering elements to be described as a continuous medium using the standard notation of nonlinear optics. We illustrate the validity and accuracy of our theoretical framework by performing measurements on a fabricated metamaterial sample composed of an array of split ring resonators (SRRs) with packaged varactors embedded in the capacitive gaps in a manner similar to that of Wang et al. [Opt. Express 16, 16058 (2008)]. Because the SRRs exhibit a predominant magnetic response to electromagnetic fields, the varactor-loaded SRR composite can be described as a magnetic material with nonlinear terms in its effective magnetic susceptibility...
Efficient transformer for electromagnetic waves
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.
GENERAL RELATIVITY AND THEORY OF ELECTROMAGNETIC DRIVE
Trunev A. P.
2015-12-01
Full Text Available The article presents the theory of the electromagnetic type of rocket motor. The apparatus consists of a magnetron and a conical cavity in which electromagnetic oscillations are excited. We explain the mechanism of trust in such a device based on Maxwell's theory and the Abraham force. We built a dynamic model of the motor and calculated the optimal parameters. It is shown, that the laws of conservation of momentum and energy for the rocket motor of electromagnetic type are true, taking into account the gravitational field. In simulation, the movement used the theory of relativity. The source of the motion in an electromagnetic drive is the mass conversion in various kinds of radiation. The optimization of the operating parameters of the device is done, namely by the excitation frequency, the magnitude of heat losses of electromagnetic energy by thermal radiation in the IR spectrum, the parameters of heat transfer and forced from the temperature dependence of the resistance of the material of the cavity walls. It was found that the effective conversion of electromagnetic energy in the trust force necessary to minimize the deviation of the excitation frequency of the primary resonance frequency of the cavity. The mechanism of formation of trust under change the metrics of space-time, taking into account the contribution of the Yang-Mills theory and electromagnetic field tensor of energymomentum has been proposed
A time domain update method for reservoir history matching of electromagnetic data
Katterbauer, Klemens
2014-01-01
Technology has fundamentally changed the oil and gas industry enabling it to extract substantial amounts of unconventional resources such as shale gas that were previously non-recoverable or uneconomical to extract. With the development and acquisition of 4D seismic data, engineers have been able to more accurately map out accurately the evolution of fluids within the reservoirs. However, they have encountered the challenge to distinguish between hydrocarbons and injected fluids. Electromagnetic methods have attracted in the last decade substantial interest to exploit the sharp resistivity contrast between hydrocarbons and water, enabling it to track water fluid fronts, optimize injection, thus improving production rates. Conventional approaches to incorporate electromagnetic data into history matching processes have been to invert these data for reservoir parameters and apply those as constraints in the matching process. This approach faces however the challenge that the computational resources required for the inversion may be significant in addition to the requirement for manual postprocessing to ensure meaningful interpretation. In this work we present a novel approach for incorporating a full wave electromagnetic time domain solver in which electromagnetic data are directly included in the history matching process. The full wave modeling enables higher accuracy representation of the underlying structures and its inclusions returns significantly better matchings and forecasts. Copyright 2014, Offshore Technology Conference.
Electromagnetic Characterization Of Metallic Sensory Alloy
Wincheski, Russell A.; Simpson, John; Wallace, Terryl A.; Newman, John A.; Leser, Paul; Lahue, Rob
2012-01-01
Ferromagnetic shape-memory alloy (FSMA) particles undergo changes in both electromagnetic properties and crystallographic structure when strained. When embedded in a structural material, these attributes can provide sensory output of the strain state of the structure. In this work, a detailed characterization of the electromagnetic properties of a FSMA under development for sensory applications is performed. In addition, a new eddy current probe is used to interrogate the electromagnetic properties of individual FSMA particles embedded in the sensory alloy during controlled fatigue tests on the multifunctional material.
Alternative expression for the electromagnetic Lagrangian
Saldanha, Pablo L
2015-01-01
We propose an alternative expression for the Lagrangian density that governs the interaction of a charged particle with external electromagnetic fields. The proposed Lagrangian is written in terms of the local superposition of the particle fields with the applied electromagnetic fields, not in terms of the particle charge and of the electromagnetic potentials as is usual. The total Lagrangian for a set of charged particles assumes a simple elegant form with the alternative formulation, giving an aesthetic support for it. The proposed Lagrangian is equivalent to the traditional one in their domain of validity and provides an interesting description of the Aharonov-Bohm effect.
Interference of electromagnetic waves in dynamic metabolism
黄卡玛; 唐敬贤; 刘永清; 徐兰
1995-01-01
Life is a continuous process of the dynamic metabolism.The influence of electromagneticwaves on the process of metabolism cannot be neglected.Here a new theory of electromagnetic interference inthe dynamic metabolism of life is proposed.The statistical dynamic equations of ion and free radical in thebiochemical reaction radiated by electromagnetic waves are given.The intensity of electromagnetic interferencecould be described with an interference factor.Good agreement can be seen between the calculated and meas-ured results for a famous experiment of radio-frequency radiation-induced calcium ion efflux enhancement.
Scattering theory of stochastic electromagnetic light waves.
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.
Interactions between electromagnetic fields and matter
Steiner, Karl-Heinz
2013-01-01
Interactions between Electromagnetic Fields and Matter deals with the principles and methods that can amplify electromagnetic fields from very low levels of signals. This book discusses how electromagnetic fields can be produced, amplified, modulated, or rectified from very low levels to enable these for application in communication systems. This text also describes the properties of matter and some phenomenological considerations to the reactions of matter when an action of external fields results in a polarization of the particle system and changes the bonding forces existing in the matter.
Review on electromagnetic welding of dissimilar materials
Shanthala, K.; Sreenivasa, T. N.
2016-12-01
Electromagnetic welding (EMW) is a highspeed joining technique that is used to join similar or dissimilar metals, as well as metals to non-metals. This technique uses electromagnetic force to mainly join conductive materials. Unlike conventional joining processes, the weld interface does not melt, thus keeping the material properties intact. Extremely high velocity and strain rate involved in the process facilitate extending the EMW technique for joining several materials. In this paper, the research and progress in electromagnetic welding are reviewed from various perspectives to provide a basis for further research.
On the genesis of Post constraint in modern electromagnetism
Lakhtakia, Akhlesh
2004-01-01
The genesis of the Post constraint is premised on two attributes of modern electromagnetism: (i) its microscopic nature, and (ii) the status of e and b as the primitive electromagnetic fields. This constraint can therefore not arise in EH--electromagnetism, wherein the primitive electromagnetic fields are the macroscopic fields E and H.
Latyshev, A V
2015-01-01
The analysis of nonlinear interaction of transversal electromagnetic field with collisionless plasma is carried out. Formulas for calculation electric current in collisionless plasma with arbitrary degree of degeneration of electronic gas are deduced. It has appeared, that the nonlinearity account leads to occurrence of the longitudinal electric current directed along a wave vector. This second current is orthogonal to the known transversal current, received at the classical linear analysis.
Characterising and modelling extended conducted electromagnetic emission
Grobler, Inus
2013-06-01
Full Text Available -1 2013 IEEE Energy Conversion Congress and Exposition Asia (ECCE Downunder), Melbourne, Australia, 3-6 June 2013 Characterising and Modelling Extended Conducted Electromagnetic Emission I Grobler1 and MN Gitau2 Department of Electrical...
Resonant Electromagnetic Shunt Damping of Flexible Structures
Høgsberg, Jan Becker
2016-01-01
Electromagnetic transducers convert mechanical energy to electrical energy and vice versa. Effective passive vibration damping of flexible structures can therefore be introduced by shunting with an accurately calibrated resonant electrical network thatcontains a capacitor to create the desired...
Detection of electromagnetic radiation using nonlinear materials
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.
Electromagnetic Form Factors of the Nucleon
Bijker, R
1997-01-01
We reanalyze the world data on the electromagnetic form factors of the nucleon. The calculations are performed in the framework of an algebraic model of the nucleon combined with vector meson dominance.
Mapping Bedrock Topography using Electromagnetic Profiling ...
Mapping Bedrock Topography using Electromagnetic Profiling. ... Journal of Applied Sciences and Environmental Management ... within the Abakaliki Urban, to map the bedrock topography which also aids us to determine the position of the ...
Electromagnetic wave analogue of electronic diode
Shadrivov, Ilya V; 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 an extraordinary strong nonlinear wave propagation effect in the same way as electronic diode function is provided by a nonlinear current characteristic of a semiconductor junction. The effect exploited in this new electromagnetic diode is an intensity-dependent polarization change in an artificial chiral metamolecule. This microwave effect exceeds a similar optical effect previously observed in natural crystals by more than 12 orders of magnitude and a direction-dependent transmission that differing by a factor of 65.
1st Applied Electromagnetic International Conference
Othman, Mohd; Aziz, Mohamad; Malek, Mohd
2015-01-01
In this book, experts from academia and industry present the latest advances in scientific theory relating to applied electromagnetics and examine current and emerging applications particularly within the fields of electronics, communications, and computer technology. The book is based on presentations delivered at APPEIC 2014, the 1st Applied Electromagnetic International Conference, held in Bandung, Indonesia in December 2014. The conference provided an ideal platform for researchers and specialists to deliver both theoretically and practically oriented contributions on a wide range of topics relevant to the theme of nurturing applied electromagnetics for human technology. Many novel aspects were addressed, and the contributions selected for this book highlight the relevance of advances in applied electromagnetics to a variety of industrial engineering problems and identify exciting future directions for research.
Scattering of electromagnetic waves by obstacles
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.
Electromagnetic field computation by network methods
Felsen, Leopold B; Russer, Peter
2009-01-01
This monograph proposes a systematic and rigorous treatment of electromagnetic field representations in complex structures. The book presents new strong models by combining important computational methods. This is the last book of the late Leopold Felsen.
Intentional Electromagnetic Interferences in Communication Devices
Md. Abdul Nabi
2015-08-01
Full Text Available IEMI is the intentional generation of electromagnetic energy introducing noise or signals into electrical andor electronic systems by interrupting damaging and diverting these systems for jamming terrorist or criminal malicious purposes.
Propagation of SLF/ELF electromagnetic waves
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).
Electromagnetic Generators and Detectors of Gravitational Waves
Grishchuk, L P
2003-01-01
The renewed serious interest to possible practical applications of gravitational waves is encouraging. Building on previous work, I am arguing that the strong variable electromagnetic fields are appropriate systems for the generation and detection of high-frequency gravitational waves (HFGW). The advantages of electromagnetic systems are clearly seen in the proposed complete laboratory experiment, where one has to ensure the efficiency of, both, the process of generation and the process of detection of HFGW. Within the family of electromagnetic systems, one still has a great variety of possible geometrical configurations, classical and quantum states of the electromagnetic field, detection strategies, etc. According to evaluations performed 30 years ago, the gap between the HFGW laboratory signal and its level of detectability is at least 4 orders of magnitude. Hopefully, new technologies of today can remove this gap and can make the laboratory experiment feasible. The laboratory experiment is bound to be exp...
Electromagnetic Behaviour of Metallic Wire Structures
Chui, S T
2013-01-01
Despite the recent development and interest in the photonics of metallic wire structures, the relatively simple concepts and physics often remain obscured or poorly explained to those who do not specialize in the field. Electromagnetic Behaviour of Metallic Wire Structures provides a clear and coherent guide to understanding these phenomena without excessive numerical calculations. Including both background material and detailed derivations of the various different formulae applied, Electromagnetic Behaviour of Metallic Wire Structures describes how to extend basic circuit theory relating to voltages, currents, and resistances of metallic wire networks to include situations where the currents are no longer spatially uniform along the wire. This lays a foundation for a deeper understanding of the many new phenomena observed in meta-electromagnetic materials. Examples of applications are included to support this new approach making Electromagnetic Behaviour of Metallic Wire Structures a comprehensive and ...
Analytic properties of the electromagnetic Green's function
Gralak, Boris; Soriano, Gabriel
2015-01-01
A general expression of the electromagnetic Green's function is derived from the inverse Helmholtz operator, where a second frequency has been introduced as a new degree of freedom. The first frequency results from the frequency decomposition of the electromagnetic field while the second frequency is associated with the dispersion of the dielectric permittivity. Then, it is shown that the electromagnetic Green's function is analytic with respect to these two complex frequencies as soon as they have positive imaginary part. Such analytic properties are also extended to complex wavevectors. Next, Kramers-Kronig expressions for the inverse Helmholtz operator and the electromagnetic Green's function are derived. In addition, these Kramers-Kronig expressions are shown to correspond to the well-known eigengenmodes expansion of the Green's function established in simple situations. Finally, the second frequency introduced as a new degree of freedom is exploited to characterize non-dispersive systems.
Electromagnetic sounding of the Earth's interior
Spichak, Viacheslav V
2015-01-01
Electromagnetic Sounding of the Earth's Interior 2nd edition provides a comprehensive up-to-date collection of contributions, covering methodological, computational and practical aspects of Electromagnetic sounding of the Earth by different techniques at global, regional and local scales. Moreover, it contains new developments such as the concept of self-consistent tasks of geophysics and , 3-D interpretation of the TEM sounding which, so far, have not all been covered by one book. Electromagnetic Sounding of the Earth's Interior 2nd edition consists of three parts: I- EM sounding methods, II- Forward modelling and inversion techniques, and III - Data processing, analysis, modelling and interpretation. The new edition includes brand new chapters on Pulse and frequency electromagnetic sounding for hydrocarbon offshore exploration. Additionally all other chapters have been extensively updated to include new developments. Presents recently developed methodological findings of the earth's study, including seism...
Technical Notes on Classical Electromagnetism, with exercises
Dantas, Christine C
2012-01-01
The present technical notes offer a brief summary of the essential points of electromagnetism at the undergraduate physics level. Some problems are presented at the end of each section; those with solutions are marked with an asterisk.
Tabletop Models for Electrical and Electromagnetic Geophysics.
Young, Charles T.
2002-01-01
Details the use of tabletop models that demonstrate concepts in direct current electrical resistivity, self-potential, and electromagnetic geophysical models. Explains how data profiles of the models are obtained. (DDR)
Composite Vector Particles in External Electromagnetic Fields
Davoudi, Zohreh
2015-01-01
Lattice quantum chromodynamics (QCD) studies of electromagnetic properties of hadrons and light nuclei, such as magnetic moments and polarizabilities, have proven successful with the use of background field methods. With an implementation of nonuniform background electromagnetic fields, properties such as charge radii and higher electromagnetic multipole moments (for states of higher spin) can be additionally obtained. This can be achieved by matching lattice QCD calculations to a corresponding low-energy effective theory that describes the static and quasi-static response of hadrons and nuclei to weak external fields. With particular interest in the case of vector mesons and spin-1 nuclei such as the deuteron, we present an effective field theory of spin-1 particles coupled to external electromagnetic fields. To constrain the charge radius and the electric quadrupole moment of the composite spin-1 field, the single-particle Green's functions in a linearly varying electric field in space are obtained within t...
Method and apparatus for measuring electromagnetic radiation
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.
Radiation damage of LHCb electromagnetic calorimeter
Barsuk, S; Kirichenko, V; Korolko, I; Malyshev, S; Rusinov, V Yu; Tarkovski, E
2000-01-01
Addressed is an extensive irradiation test program carried on to establish proper design and materials to build electromagnetic calorimeter that matches radiation conditions of the LHCb experiment at CERN. The results obtained are compared with measurements by other groups.
2nd Applied Electromagnetic International Conference
Sulaiman, Hamzah; Othman, Mohd; Aziz, Mohamad; Malek, Mohd
2017-01-01
In this book, experts from academia and industry present the latest advances in scientific theory relating to applied electromagnetics and examine current and emerging applications particularly within the fields of electronics, communications, and computer technology. The book is based on presentations delivered at APPEIC 2015, the 2nd Applied Electromagnetic International Conference, held in Krabi, Thailand in December 2015. The conference provided an ideal platform for researchers and specialists to deliver both theoretically and practically oriented contributions on a wide range of topics relevant to the theme of nurturing applied electromagnetics for human technology. Many novel aspects were addressed, and the contributions selected for this book highlight the relevance of advances in applied electromagnetics to a variety of industrial engineering problems and identify exciting future directions for research.
Electromagnetically induced classical and quantum Lau effect
Qiu, Tianhui; Yang, Guojian; Xiong, Jun; Xu, Deqin
2016-07-01
We present two schemes of Lau effect for an object, an electromagnetically induced grating generated based on the electromagnetically induced effect. The Lau interference pattern is detected either directly in the way of the traditional Lau effect measurement with a classical thermal light being the imaging light, or indirectly and nonlocally in the way of two-photon coincidence measurement with a pair of entangled photons being the imaging light.
Unification of Gravity and Electromagnetism and Cosmology
Ghose, Partha
2016-01-01
It is first argued that radiation by a uniformly accelerated charge in flat space-time indicates the need for a unified geometric theory of gravity and electromagnetism. Such a theory, based on a metric-affine $U_4$ manifold, is constructed with the torsion pseudo-vector $\\Gamma_\\mu$ linking gravity and electromagnetism. This conceptually simple extension results in (i) Einstein's equations being modified by a vacuum energy $\\Gamma_\\mu\\Gamma_\
Progress of Expert Systems in Electromagnetic Engineering
LAI Sheng-jian; WANG Bing-zhong
2005-01-01
It is urgent to solve various problems in electromagnetic (EM) engineering under the increasingly complicated environment. Some expert systems (ES) come into being just to keep up with the demand for solving these problems. Combined with the analysis of development of ES technology and the development trend of EM engineering software in recent years, the application of ES technology in EM engineering is discussed, and especially the progress of complete ES in electromagnetic compatible (EMC) is introduced.
ELECTROMAGNETIC MWD/LWD - WHERE AND WHY?
Ivo Steiner
1996-12-01
Full Text Available Application of electromagnetics as a mean of data transfer from bottom hole assembly to the surface during deep well drilling is described. Particularly, it is convenient when drilling with foam, aerated mud or air drilling in underbalance condition. Historic development of electromagnetics (EM and of EM Measurement While Drilling (EM MWD is elaborated briefly. Accentuated is the problem of attenuation of EM waves propagating through the rocks.
Electromagnetic Transport From Microtearing Mode Turbulence
Guttenfelder, W; Kaye, S M; Nevins, W M; Wang, E; Bell, R E; Hammett, G W; LeBlanc, B P; Mikkelsen, D R
2011-03-23
This Letter presents non-linear gyrokinetic simulations of microtearing mode turbulence. The simulations include collisional and electromagnetic effects and use experimental parameters from a high beta discharge in the National Spherical Torus Experiment (NSTX). The predicted electron thermal transport is comparable to that given by experimental analysis, and it is dominated by the electromagnetic contribution of electrons free streaming along the resulting stochastic magnetic field line trajectories. Experimental values of flow shear can significantly reduce the predicted transport.
Problem of interactions: electromagnetic particles interaction
Sannikov-Proskuryakov, S S
2001-01-01
The electromagnetic interactions between charged particles are derived on the basis of the particles dynamic theory, proposed in the work of Sannikov. The electromagnetic interactions exist only in the relativistic model of the bihamiltonian system, based on the Heisenberg algebra. Existence of this type of interactions is connected with the U sub e (1)-degeneration of the basic state of the relativistic bihamiltonian system, lying in the basis of the given theory
HIGH POWER APPLICATIONS OF ELECTROMAGNETIC DEVICES
VASILE DOBREF
2016-06-01
Full Text Available For the next generation, conventional weapon will touch the best performance limits and will became more and more what in what more an important part plans of improvement systems of weapon to the future. Physical laws that govern electromagnetic propulsion of guns, enabling them higher speeds than those of conventional arms projectiles. This is substantially benefit electromagnetic weapons - using electricity as energy for an lectromagnetic weapons.
Mathematics and electromagnetism; Matematicas y electromagnetismo
Rodriguez Danta, M.
2000-07-01
Symbiosis between mathematics and electromagnetism is analyzed in a simple and concise manner by taking a historical perspective. The universal tool character of mathematical models allowed the transfer of models from several branches of physics into the realm of electromagnetism by drawing analogies. The mutual interdependence between covariant formulation and tensor calculus is marked. The paper focuses on the guiding idea of field theory and Maxwell's equations. Likewise, geometrization of interactions in connection with gauge fields is also noted. (Author)
Low-Frequency Electromagnetic Backscattering from Tunnels
Casey, K; Pao, H
2007-01-16
Low-frequency electromagnetic scattering from one or more tunnels in a lossy dielectric half-space is considered. The tunnel radii are assumed small compared to the wavelength of the electromagnetic field in the surrounding medium; a tunnel can thus be modeled as a thin scatterer, described by an equivalent impedance per unit length. We examine the normalized backscattering width for cases in which the air-ground interface is either smooth or rough.
Linear peristaltic pump based on electromagnetic actuators
Maddoui Lotfi
2014-01-01
Full Text Available In this paper a study and design of a linear peristaltic pump are presented. A set of electromagnetic (solenoid actuators is used as the active tools to drag the liquid by crushing an elastic tube. The pump consists of six serially-connected electromagnetic actuators controlled via an electronic board. This may be considered as a simulated peristalsis action of intestines. The dynamic performances of the pump are investigated analytically and experimentally.
Electromagnetic Detection and Identification of Complex Structures
2008-12-01
1 ELECTROMAGNETIC DETECTION AND IDENTIFICATION OF COMPLEX STRUCTURES I. Kohlberg Kohlberg Associates Reston, Virginia, 20190-4440 S.A...TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Kohlberg Associates Reston, Virginia, 20190-4440 8...Electromagnetic Theory, 2 nd ed. IEEE Press, New York. von Laven, S.A., Albritton, N.G., Baginski, T.A., Hodel, A.S., McMillan, R.W., Kohlberg
Energetic constraints on electromagnetic signals from double black hole mergers
Dai, Lixin; Miller, M Coleman
2016-01-01
The possible Fermi detection of an electromagnetic counterpart to the double black hole merger GW150914 has inspired many theoretical models, some of which propose that the holes spiraled together inside a massive star. However, we show that the heat produced by the dynamical friction on such black hole orbits can exceed the stellar binding energy by a large factor, which means that this heat could destroy the star and thus make it difficult for enough gas to be near the holes at merger to produce detectable photons. These considerations must be taken into account when models are proposed for electromagnetic counterparts to the coalescence of two stellar-mass black holes. We find that only when the two black holes form very close to the center can the star avoid destruction. In that case, dynamical friction can make the black holes coalesce faster than they would in vacuum, which leads to a modification of the gravitational waveform that is potentially observable by advanced LIGO.
Transformation electromagnetics and metamaterials fundamental principles and applications
Werner, Douglas H
2013-01-01
Transformation electromagnetics is a systematic design technique for optical and electromagnetic devices that enables novel wave-material interaction properties. The associated metamaterials technology for designing and realizing optical and electromagnetic devices can control the behavior of light and electromagnetic waves in ways that have not been conventionally possible. The technique is credited with numerous novel device designs, most notably the invisibility cloaks, perfect lenses and a host of other remarkable devices.Transformation Electromagnetics and Metamaterials: Fundamental Princ
Broadband electromagnetic analysis of compacted kaolin
Bore, Thierry; Wagner, Norman; Cai, Caifang; Scheuermann, Alexander
2017-01-01
The mechanical compaction of soil influences not only the mechanical strength and compressibility but also the hydraulic behavior in terms of hydraulic conductivity and soil suction. At the same time, electric and dielectric parameters are increasingly used to characterize soil and to relate them with mechanic and hydraulic parameters. In the presented study electromagnetic soil properties and suction were measured under defined conditions of standardized compaction tests. The impact of external mechanical stress conditions of nearly pure kaolinite was analyzed on soil suction and broadband electromagnetic soil properties. An experimental procedure was developed and validated to simultaneously determine mechanical, hydraulic and broadband (1 MHz-3 GHz) electromagnetic properties of the porous material. The frequency dependent electromagnetic properties were modeled with a classical mixture equation (advanced Lichtenecker and Rother model, ALRM) and a hydraulic-mechanical-electromagnetic coupling approach was introduced considering water saturation, soil structure (bulk density, porosity), soil suction (pore size distribution, water sorption) as well as electrical conductivity of the aqueous pore solution. Moreover, the relaxation behavior was analyzed with a generalized fractional relaxation model concerning a high-frequency water process and two interface processes extended with an apparent direct current conductivity contribution. The different modeling approaches provide a satisfactory agreement with experimental data for the real part. These results show the potential of broadband electromagnetic approaches for quantitative estimation of the hydraulic state of the soil during densification.
Medical applications of electromagnetic fields
Lai, Henry C.; Singh, Narendra P.
2010-04-01
In this article, we describe two possible applications of low-intensity non-ionizing electromagnetic fields (EMF) for the treatment of malaria and cancer, respectively. In malaria treatment, a low-intensity extremely-low frequency magnetic field can be used to induce vibration of hemozoin, a super-paramagnetic polymer particle, inside malaria parasites. This disturbance could cause free radical and mechanical damages leading to the death of the parasite. This concept has been tested in vitro on malaria parasites and found to be effective. This may provide a low cost effective treatment for malaria infection in humans. The rationale for cancer treatment using low-intensity EMF is based on two concepts that have been well established in the literature: (1) low-intensity non-thermal EMF enhances cytotoxic free radicals via the iron-mediated Fenton reaction; and (2) cancer cells have higher amounts of free iron, thus are more susceptible to the cytotoxic effects of EMF. Since normal cells contain minimal amount of free iron, the effect would be selectively targeting cancer cells. Thus, no adverse side effect would be expected as in traditional chemotherapy and radiation therapy. This concept has also been tested on human cancer cell and normal cells in vitro and proved to be feasible.
Multifunctional hybrids for electromagnetic absorption
Huynen, I. [Research Center in Micro and Nanoscopic Materials and Electronic Devices, CeRMiN, Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Information and Communications Technologies, Electronics and Applied Mathematics (ICTEAM), Microwave Laboratory, Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Quievy, N. [Institute of Condensed Matter and Nanosciences (IMCN), Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Bailly, C. [Research Center in Micro and Nanoscopic Materials and Electronic Devices, CeRMiN, Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Institute of Condensed Matter and Nanosciences (IMCN), Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Institute of Mechanics, Materials and Civil Engineering (iMMC), Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Bollen, P. [Information and Communications Technologies, Electronics and Applied Mathematics (ICTEAM), Microwave Laboratory, Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Institute of Condensed Matter and Nanosciences (IMCN), Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Institute of Mechanics, Materials and Civil Engineering (iMMC), Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Detrembleur, C. [Center for Education and Research on Macromolecules (CERM), University of Liege, Sart-Tilman B6a, 4000 Liege (Belgium); Eggermont, S.; Molenberg, I. [Information and Communications Technologies, Electronics and Applied Mathematics (ICTEAM), Microwave Laboratory, Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Thomassin, J.M.; Urbanczyk, L. [Center for Education and Research on Macromolecules (CERM), University of Liege, Sart-Tilman B6a, 4000 Liege (Belgium)
2011-05-15
Highlights: > EM absorption requires low dielectric constant and {approx}1 S/m electrical conductivity. > New hybrids were processed with CNT-filled polymer foam inserted in Al honeycomb. > The EM absorption in the GHz range is superior to any known material. > A closed form model is used to guide the design of the hybrid. > The architectured material is light with potential for thermal management. - Abstract: Electromagnetic (EM) interferences are ubiquitous in modern technologies and impact on the reliability of electronic devices and on living cells. Shielding by EM absorption, which is preferable over reflection in certain instances, requires combining a low dielectric constant with high electrical conductivity, which are antagonist properties in the world of materials. A novel class of hybrid materials for EM absorption in the gigahertz range has been developed based on a hierarchical architecture involving a metallic honeycomb filled with a carbon nanotube-reinforced polymer foam. The waveguide characteristics of the honeycomb combined with the performance of the foam lead to unexpectedly large EM power absorption over a wide frequency range, superior to any known material. The peak absorption frequency can be tuned by varying the shape of the honeycomb unit cell. A closed form model of the EM reflection and absorption provides a tool for the optimization of the hybrid. This designed material sets the stage for a new class of sandwich panels combining high EM absorption with mass efficiency, stiffness and thermal management.
Octonionic matrix representation and electromagnetism
Chanyal, B. C. [Kumaun University, S. S. J. Campus, Almora (India)
2014-12-15
Keeping in mind the important role of octonion algebra, we have obtained the electromagnetic field equations of dyons with an octonionic 8 x 8 matrix representation. In this paper, we consider the eight - dimensional octonionic space as a combination of two (external and internal) four-dimensional spaces for the existence of magnetic monopoles (dyons) in a higher-dimensional formalism. As such, we describe the octonion wave equations in terms of eight components from the 8 x 8 matrix representation. The octonion forms of the generalized potential, fields and current source of dyons in terms of 8 x 8 matrix are discussed in a consistent manner. Thus, we have obtained the generalized Dirac-Maxwell equations of dyons from an 8x8 matrix representation of the octonion wave equations in a compact and consistent manner. The generalized Dirac-Maxwell equations are fully symmetric Maxwell equations and allow for the possibility of magnetic charges and currents, analogous to electric charges and currents. Accordingly, we have obtained the octonionic Dirac wave equations in an external field from the matrix representation of the octonion-valued potentials of dyons.
Disentanglement of Electromagnetic Baryon Properties
Sadasivan, Daniel; Doring, Michael
2017-01-01
Through recent advances in experimental techniques, the precise extraction of the spectrum of baryonic resonances and their properties becomes possible. Helicity couplings at the resonance pole are fundamental parameters describing the electromagnetic properties of resonances and enabling the comparison of theoretical models with data. We have extracted them from experiments carried out at Jefferson Lab and other facilities using a multipole analysis within the Julich-Bonn framework. Special attention has been paid to the uncertainties and correlations of helicity couplings. Using the world data on the reaction γp -> ηp , we have calculated, for the first time, the covariance matrix. Our results are useful in several ways. They quantify uncertainties but also correlations of helicity couplings. Second, they can tell us quantitatively how useful a given polarization measurement is. Third, they can tell us how the measurement of a new observable would constrain and disentangle the resonance properties which could be helpful in the design of new experiments. Finally, on the subject of the missing resonance problem, model selection techniques and statistical tests allow us to quantify the significance of whether a resonance exists. Supported by NSF CAREER Grant No. PHY-1452055, NSF PIF Grant No. 1415459, by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177, and by Research Center Julich through the HPC grant jikp07.
Aircraft Lightning Electromagnetic Environment Measurement
Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.
2011-01-01
This paper outlines a NASA project plan for demonstrating a prototype lightning strike measurement system that is suitable for installation onto research aircraft that already operate in thunderstorms. This work builds upon past data from the NASA F106, FAA CV-580, and Transall C-180 flight projects, SAE ARP5412, and the European ILDAS Program. The primary focus is to capture airframe current waveforms during attachment, but may also consider pre and post-attachment current, electric field, and radiated field phenomena. New sensor technologies are being developed for this system, including a fiber-optic Faraday polarization sensor that measures lightning current waveforms from DC to over several Megahertz, and has dynamic range covering hundreds-of-volts to tens-of-thousands-of-volts. A study of the electromagnetic emission spectrum of lightning (including radio wave, microwave, optical, X-Rays and Gamma-Rays), and a compilation of aircraft transfer-function data (including composite aircraft) are included, to aid in the development of other new lightning environment sensors, their placement on-board research aircraft, and triggering of the onboard instrumentation system. The instrumentation system will leverage recent advances in high-speed, high dynamic range, deep memory data acquisition equipment, and fiber-optic interconnect.
Medical applications of electromagnetic fields
Lai, Henry C; Singh, Narendra P, E-mail: hlai@u.washington.ed [Department of Bioengineering, University of Washington, Seattle, WA 98195-5061 (United States)
2010-04-15
In this article, we describe two possible applications of low-intensity non-ionizing electromagnetic fields (EMF) for the treatment of malaria and cancer, respectively. In malaria treatment, a low-intensity extremely-low frequency magnetic field can be used to induce vibration of hemozoin, a super-paramagnetic polymer particle, inside malaria parasites. This disturbance could cause free radical and mechanical damages leading to the death of the parasite. This concept has been tested in vitro on malaria parasites and found to be effective. This may provide a low cost effective treatment for malaria infection in humans. The rationale for cancer treatment using low-intensity EMF is based on two concepts that have been well established in the literature: (1) low-intensity non-thermal EMF enhances cytotoxic free radicals via the iron-mediated Fenton reaction; and (2) cancer cells have higher amounts of free iron, thus are more susceptible to the cytotoxic effects of EMF. Since normal cells contain minimal amount of free iron, the effect would be selectively targeting cancer cells. Thus, no adverse side effect would be expected as in traditional chemotherapy and radiation therapy. This concept has also been tested on human cancer cell and normal cells in vitro and proved to be feasible.
Small-bore hypervelocity Electromagnetic Launcher research facility
Hurn, T. W.; Chapelle, S.; Lupan, S. P.; Holland, L.; Homeyer, W. G.; Rawls, J. M.
1993-01-01
A small-bore hypervelocity Electromagnetic Launcher laboratory research facility has been developed which has launched a 2-g projectile to a velocity in excess of 3.5 km/sec. This turn-key laboratory includes a 1 cm, square-bore railgun with a helium gas preaccelerator; a modular 328 kJ capacitor bank; a fiber-optically linked programmable logic control system with a graphical operator interface; a data acquisition system with current, magnetic, and projectile position diagnostics; and a flight range which provides in-flight velocity measurements and safely stops and contains the projectile. The control system fires the preaccelerator and, on receipt of an optical signal, fires the capacitor bank modules simultaneously or in a staggered mode. Armature separation and stalling limit the overall performance of the system. Changes in pulse shape and bore materials significantly improved performance. Attention is given to methods used to minimize armature separation and improve performance.
Electromagnetic non-destructive technique for duplex stainless steel characterization
Rocha, João Vicente; Camerini, Cesar; Pereira, Gabriela
2016-02-01
Duplex stainless steel (DSS) is a two-phase (ferrite and austenite) material, which exhibits an attractive combination of mechanical properties and high corrosion resistance, being commonly employed for equipment of petrochemical plants, refining units and oil & gas platforms. The best properties of DSS are achieved when the phases are in equal proportions. However, exposition to high temperatures (e.g. welding process) may entail undesired consequences, such as deleterious phases precipitation (e.g. sigma, chi) and different proportion of the original phases, impairing dramatically the mechanical and corrosion properties of the material. A detailed study of the magnetic behavior of DSS microstructure with different ferrite austenite ratios and deleterious phases content was accomplished. The non destructive method evaluates the electromagnetic properties changes in the material and is capable to identify the presence of deleterious phases into DSS microstructure.
Bo Wang; Shujing Li; Jingqin Yao; Jie Ma; Feng Peng; Gang Jiang; Hai Wang
2005-01-01
@@ We report an experimental observation of the variation in linewidth of the electromagnetically induced transparency (EIT) resonance in a three-level A-type system for several laser bandwidths in a Rb vapor cell, with and without a buffer gas. It is found, using narrow bandwidth (about 20 kHz) diode laser for both coupling and probe beams, that the linewidth of the EIT resonance can be significantly narrowed in the Rb vapor cell with the buffer gas. The results are in good qualitative agreement with a simple theoretical calculation.
Design method of electromagnetic field applied to Al-alloy electromagnetic casting
YANG Jing; DANG Jing-zhi; PENG You-gen; CHENG Jun
2006-01-01
The electromagnetic pump imposes the electromagnetic motive force (Lorentz force) on the liquid metal directly and makes it move along the definite direction by using the function of electric current and magnetic field in the conducting fluid.Compared with the traditional die casting, the system of counter-gravity casting can effectively control the speed of fillingto make Al-alloy liquid fill steadily by adjusting controlled-current. So the foundry defects can be decreased or avoided effectively by this system. Based on the theory of electromagnetic pump, the design method of electromagnetic field in electromagnetic pump was investigated emphatically. The rule of magnetic induction intensity B influenced by the divided electromagnet airgap's size was founded. Furthermore, the empirical formula of magnetic induction intensity B in a magnetic airgap for an open magnet in the saturated state was deduced by mathematics regression analysis. Counter-gravity casting applied to the Al-alloy electromagnetic filling was developed with this method. Besides, the electromagnetism filling counter-gravity casting process of the turbo-charge blade wheel was also fixed. The eligibility rate of blade wheel produced by such technique can be increased to 98%. The casts have compact structure and excellent capability.
Requirements for gas quality and gas appliances
Levinsky, Howard; Gersen, Sander; Kiewiet, Bert
2015-01-01
Introduction The gas transmission network in the Netherlands transports two different qualities of gas, low-calorific gas known as G-gas or L-gas and, high calorific gas (H-gas). These two gas qualities are transported in separate networks, and are connected by means of five blending and conversion
Is Electromagnetic Gravity Control Possible?
Vargas, Jose G.; Torr, Douglas G.
2004-02-01
We study the interplay of Einstein's Gravitation (GR) and Maxwell's Electromagnetism, where the distribution of energy-momentum is not presently known (The Feynman Lectures, Vol 2, Chapter 27, section 4). As Feynman himself stated, one might in principle use Einstein's equations of GR to find such a distribution. GR (born in 1915) presently uses the Levi-Civita connection, LCC (the LCC was born two years after GR as a new concept, and not just as the pre-existing Christoffel symbols that represent it). Around 1927, Einstein proposed for physics an alternative to the LCC that constitutes a far more sensible and powerful affine enrichment of metric Riemannian geometry. It is called teleparallelism (TP). Its Finslerian version (i.e. in the space-time-velocity arena) permits an unequivocal identification of the EM field as a geometric quantity. This in turn permits one to identify a completely geometric set of Einstein equations from curvature equations. From their right hand side, one may obtain the actual distribution of EM energy-momentum. It is consistent with Maxwell's equations, since these also are implied by the equations of structure of TP. We find that the so-far-unknown terms in this distribution amount to a total differential and do not, therefore, alter the value of the total EM energy-momentum. And yet these extra terms are at macroscopic distances enormously larger than the standard quadratic terms. This allows for the generation of measurable gravitational fields by EM fields. We thus answer affirmatively the question of the title.
[Health effects of electromagnetic fields].
Röösli, Martin
2013-12-01
Use of electricity causes extremely low frequency magnetic fields (ELF-MF) and wireless communication devices emit radiofrequency electromagnetic fields (RF-EMF). Average ELF-MF exposure is mainly determined by high voltage power lines and transformers at home or at the workplace, whereas RF-EMF exposure is mainly caused by devices operating close to the body (mainly mobile and cordless phones). Health effects of EMF are controversially discussed. The IARC classified ELF-MF and RF-EMF as possible carcinogenic. Most consistent epidemiological evidence was found for an association between ELF-MF and childhood leukaemia. If causal, 1 - 4 percent of all childhood leukaemia cases could be attributed to ELF-MF. Epidemiological research provided some indications for an association between ELF-MF and Alzheimer's diseases as well as amyotrophic lateral sclerosis, although not entirely consistent. Regarding mobile phones and brain tumours, some studies observed an increased risk after heavy or long term use on the one hand. On the other hand, brain tumour incidence was not found to have increased in the last decade in Sweden, England or the US. Acute effects of RF-EMF on non-specific symptoms of ill health seem unlikely according to randomized and double blind provocation studies. However, epidemiological research on long term effects is still limited. Although from the current state of the scientific knowledge a large individual health risk from RF-EMF exposure is unlikely, even a small risk would have substantial public health relevance because of the widespread use of wireless communication technologies.
Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert
2016-05-03
Measurement of a precessional rate of a gas, such as an alkali gas, in a magnetic field is made by promoting a non-uniform precession of the gas in which substantially no net magnetic field affects the gas during a majority of the precession cycle. This allows sensitive gases that would be subject to spin-exchange collision de-phasing to be effectively used for extremely sensitive measurements in the presence of an environmental magnetic field such as the Earth's magnetic field.
Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert
2016-05-03
Measurement of a precessional rate of a gas, such as an alkali gas, in a magnetic field is made by promoting a non-uniform precession of the gas in which substantially no net magnetic field affects the gas during a majority of the precession cycle. This allows sensitive gases that would be subject to spin-exchange collision de-phasing to be effectively used for extremely sensitive measurements in the presence of an environmental magnetic field such as the Earth's magnetic field.
Guiochon, Georges; Guillemin, Claude L.
1990-11-01
Gas chromatography is a powerful separation technique for gas and vapor mixtures. Combining separation and on-line detection permits accurate quantitative analysis of complex mixtures, including traces of compounds down to parts per trillions in some particular cases. The importance of gas chromatography in quality control and process control in the chemical and drug industry, in environmental pollution investigations and in clinical analysis is critical. The principles of the technique are discussed, the main components of a gas chromatograph are described and some idea of the importance of the applications is given.
Optical fiber gas sensing system based on FBG filtering
Wang, Shutao
2008-10-01
An optical fiber gas sensing system based on the law of Beer-Lambert is designed to determine the concentration of gas. This technique relies on the fact that the target gas has a unique, well-defined absorption characteristic within the infrared region of electromagnetic spectrum. The narrow-band filtering characteristic of optical fiber Bragg grating is used to produce the narrow spectrum light signal. An aspheric objective optical fiber collimator is used in the system as an optical fiber gas sensing detector to improve the sensitivity and stability. Experimental results show there is a high measuring sensitivity at 0.01%, and the measuring range goes beyond 5%.
Electromagnetic characteristics of carbon nanotube film materials
Zhang Wei
2015-08-01
Full Text Available Carbon nanotube (CNT possesses remarkable electrical conductivity, which shows great potential for the application as electromagnetic shielding material. This paper aims to characterize the electromagnetic parameters of a high CNT loading film by using waveguide method. The effects of layer number of CNT laminate, CNT alignment and resin impregnation on the electromagnetic characteristics were analyzed. It is shown that CNT film exhibits anisotropic electromagnetic characteristic. Pristine CNT film shows higher real part of complex permittivity, conductivity and shielding effectiveness when the polarized direction of incident wave is perpendicular to the winding direction of CNT film. For the CNT film laminates, complex permittivity increases with increasing layer number, and correspondingly, shielding effectiveness decreases. The five-layer CNT film shows extraordinary shielding performance with shielding effectiveness ranging from 67 dB to 78 dB in X-band. Stretching process induces the alignment of CNTs. When aligned direction of CNTs is parallel to the electric field, CNT film shows negative permittivity and higher conductivity. Moreover, resin impregnation into CNT film leads to the decrease of conductivity and shielding effectiveness. This research will contribute to the structural design for the application of CNT film as electromagnetic shielding materials.
Building health: The need for electromagnetic hygiene?
Jamieson, Isaac A.; Holdstock, Paul; ApSimon, Helen M.; Bell, J. Nigel B.
2010-04-01
Whilst the electromagnetic nature of the built environment has changed considerably over the past century, little thought is at present given to the possible advantages of creating electromagnetic microenvironments that more closely resemble those found in nature and/or developing biologically-friendly technology aligned more closely to its operating principles. This review paper examines how more natural exposures to a variety of electromagnetic phenomena could be re-introduced into the built environment, possible benefits that might arise, and discusses the extent to which there may be tangible benefits obtainable from introducing more rigorous properly considered electromagnetic hygiene measures. Amongst the matters discussed are: the effects of different materials, finishes and electrical items on charge generation (and the effects of excess charge on contaminant deposition); the possible benefits of suitably grounding conductive objects (including humans) in order to reduce excess charge and contaminant deposition; how the presence of vertical electric field regimes, similar to those found in nature, may enhance biological performance; and possible pitfalls to avoid when seeking to introduce appropriate electromagnetic hygiene regimes.
Controlling electromagnetic scattering with wire metamaterial resonators
Filonov, Dmitry S.; Shalin, Alexander S.; Iorsh, Ivan; Belov, Pavel A.; Ginzburg, Pavel
2016-10-01
Manipulation of radiation is required for enabling a span of electromagnetic applications. Since properties of antennas and scatterers are very sensitive to a surrounding environment, macroscopic artificially created materials are good candidates for shaping their characteristics. In particular, metamaterials enable controlling both dispersion and density of electromagnetic states, available for scattering from an object. As the result, properly designed electromagnetic environment could govern waves' phenomena. Here electromagnetic properties of scattering dipoles, situated inside a wire medium (metamaterial) are analyzed both numerically and experimentally. Impact of the metamaterial geometry, dipole arrangement inside the medium, and frequency of the incident radiation on scattering phenomena was studied. It was shown that the resonance of the dipole hybridizes with Fabry-Perot modes of the metamaterial, giving rise to a complete reshaping of electromagnetic properties. Regimes of controlled scattering suppression and super-scattering were observed. Numerical analysis is in an agreement with experiments, performed at the GHz spectral range. The reported approach to scattering control with metamaterials could be directly mapped into optical and infrared spectral ranges by employing scalability properties of Maxwell's equations.
Nonholonomic catheter path reconstruction using electromagnetic tracking
Lugez, Elodie; Sadjadi, Hossein; Akl, Selim G.; Fichtinger, Gabor
2015-03-01
Catheter path reconstruction is a necessary step in many clinical procedures, such as cardiovascular interventions and high-dose-rate brachytherapy. To overcome limitations of standard imaging modalities, electromagnetic tracking has been employed to reconstruct catheter paths. However, tracking errors pose a challenge in accurate path reconstructions. We address this challenge by means of a filtering technique incorporating the electromagnetic measurements with the nonholonomic motion constraints of the sensor inside a catheter. The nonholonomic motion model of the sensor within the catheter and the electromagnetic measurement data were integrated using an extended Kalman filter. The performance of our proposed approach was experimentally evaluated using the Ascension's 3D Guidance trakStar electromagnetic tracker. Sensor measurements were recorded during insertions of an electromagnetic sensor (model 55) along ten predefined ground truth paths. Our method was implemented in MATLAB and applied to the measurement data. Our reconstruction results were compared to raw measurements as well as filtered measurements provided by the manufacturer. The mean of the root-mean-square (RMS) errors along the ten paths was 3.7 mm for the raw measurements, and 3.3 mm with manufacturer's filters. Our approach effectively reduced the mean RMS error to 2.7 mm. Compared to other filtering methods, our approach successfully improved the path reconstruction accuracy by exploiting the sensor's nonholonomic motion constraints in its formulation. Our approach seems promising for a variety of clinical procedures involving reconstruction of a catheter path.
The electromagnetic potentials without the gauge transformations
Espinoza, Augusto; Chubykalo, Andrey; Rodriguez, Alejandro Gutierrez; Hernandez, Maria de los Angeles [Universidad Autonoma de Zacatecas (Mexico). Unidad Academica de Fisica
2011-07-01
In this note we show that the use of the Helmholtz theorem lead to derivation of uniquely determined electromagnetic potentials without making use of the gauge transformation. These potentials correspond to the potentials obtained by imposing so-called Coulomb condition (gauge) in the traditional approach. We show that the electromagnetic field comprises two components, one of which is characterized by its instantaneous action at a distance, whereas another one propagates in the retarded form with the velocity of light. One of the theoretical consequences of this new definition is that the electromagnetic potentials are real physical quantities as well as the electric and magnetic fields. We show that the reality of the electromagnetic potentials in quantum-mechanics is also a property of these potentials in the classical electrodynamics. Equations for potentials obtained in our approach are already separated with respect to vector and scalar potentials, so there is no necessity in using the gauge transformations and, accordingly, in making use of either Lorentz or Coulomb condition. The vector potential and scalar potential introduced thus are uniquely defined. The scalar potential is a generator of the so called instantaneous action at a distance, whereas the solenoidal vector potential can propagate with the velocity of light and it is responsible for the retarded action of the electromagnetic field. (author)
Stirring, not shaking: binary black holes' effects on electromagnetic fields
Palenzuela, Carlos; Lehner, Luis; Liebling, Steven L; Neilsen, David
2009-01-01
In addition to producing gravitational waves (GW), the dynamics of a binary black hole system could induce emission of electromagnetic (EM) radiation by affecting the behavior of plasmas and electromagnetic fields in their vicinity. We here study how the electromagnetic fields are affected by a pair of orbiting black holes through the merger. In particular, we show how the binary's dynamics induce a variability in possible electromagnetically induced emissions as well as a possible enhancement of electromagnetic fields during the late-merge and merger epochs. These time dependent features will likely leave their imprint in processes generating detectable emissions and can be exploited in the detection of electromagnetic counterparts of gravitational waves.
Power law inflation with electromagnetism
Luo, Xianghui; Isenberg, James, E-mail: isenberg@uoregon.edu
2013-07-15
We generalize Ringström’s global future causal stability results (Ringström 2009) [11] for certain expanding cosmological solutions of the Einstein-scalar field equations to solutions of the Einstein–Maxwell-scalar field system. In particular, after noting that the power law inflationary spacetimes (M{sup n+1},g{sup -hat}, ϕ{sup -hat}) considered by Ringström (2009) in [11] are solutions of the Einstein–Maxwell-scalar field system (with exponential potential) as well as of the Einstein-scalar field system (with the same exponential potential), we consider (nonlinear) perturbations of initial data sets of these spacetimes which include electromagnetic perturbations as well as gravitational and scalar perturbations. We show that if (as in Ringström (2009) [11]) we focus on pairs of relatively scaled open sets U{sub R{sub 0}}⊂U{sub 4R{sub 0}} on an initial slice of (M{sup n+1},g{sup -hat}), and if we choose a set of perturbed data which on U{sub 4R{sub 0}} is sufficiently close to that of (M{sup n+1},g{sup -hat},ϕ{sup -hat}, A{sup -hat} = 0), then in the maximal globally hyperbolic spacetime development (M{sup n+1},g,ϕ,A) of this data via the Einstein–Maxwell-scalar field equations, all causal geodesics emanating from U{sub R{sub 0}} are future complete (just as in (M{sup n+1},g{sup -hat})). We also verify that, in a certain sense, the future asymptotic behavior of the fields in the spacetime developments of the perturbed data sets does not differ significantly from the future asymptotic behavior of (M{sup n+1},g{sup -hat}, ϕ{sup -hat}, A{sup -hat} = 0). -- Highlights: •We prove stability of expanding solutions of the Einstein–Maxwell-scalar field equations. •All nearby solutions are geodesically complete. •The topology of the initial slice is irrelevant to our stability results.
Babitski, V. S.; Callegari, Th.; Simonchik, L. V.; Sokoloff, J.; Usachonak, M. S.
2017-08-01
The ability to use plasma columns of pulse discharges in argon at atmospheric pressure to form a one-dimensional electromagnetic band gap structure (or electromagnetic crystal) in the X-band waveguide is demonstrated. We show that a plasma electromagnetic crystal attenuates a microwave propagation in the stopband more than by 4 orders of magnitude. In order to obtain an effective control of the transmission spectrum comparable with a metallic regular structure, the electron concentration in plasma inhomogeneities should vary within the range from 1014 cm-3 to 1016 cm-3, while gas temperature and mean electron energy must be in the range of 2000 K and 0.5 eV, respectively, to lower electron collision frequency around 1010 s-1. We analyze in detail the time evolution response of the electromagnetic crystal according to the plasma parameters for the duration of the discharge. The interest of using atmospheric pressure discharges is to increase the microwave breakdown threshold in discharge volumes, whereby it becomes possible to perform dynamic control of high power microwaves.
Electromagnetic currents induced by color fields
Tanji, Naoto
2015-01-01
The quark production in classical color fields is investigated with a focus on the induction of an electromagnetic current by produced quarks. We show that the SU(2) and the SU(3) theories lead significantly different results for the electromagnetic current. In uniform SU(2) color fields, the net electromagnetic current is not generated, while for SU(3) the net current is induced depending on the color direction of background fields. Also the numerical study of the quark production in inhomogeneous color fields is done. Motivated by gauge field configurations provided by the color glass condensate framework, we introduce an ensemble of randomly distributed color electric fluxtubes. The spectrum of photons emitted from the quarks by a classical process is shown.
Controlling the Electromagnetic Field Confinement with Metamaterials
Bonache, Jordi; Zamora, Gerard; Paredes, Ferran; Zuffanelli, Simone; Aguilà, Pau; Martín, Ferran
2016-11-01
The definition of a precise illumination region is essential in many applications where the electromagnetic field should be confined in some specific volume. By using conventional structures, it is difficult to achieve an adequate confinement distance (or volume) with negligible levels of radiation leakage beyond it. Although metamaterial structures and metasurfaces are well-known to provide high controllability of their electromagnetic properties, this feature has not yet been applied to solve this problem. We present a method of electromagnetic field confinement based on the generation of evanescent waves by means of metamaterial structures. With this method, the confinement volume can be controlled, namely, it is possible to define a large area with an intense field without radiation leakage. A prototype working in the microwave region has been implemented, and very good agreement between the measurements and the theoretical prediction of field distribution has been obtained.
Spectrum and electromagnetic transitions of bottomonium
Deng, Wei-Jun; Gui, Long-Cheng; Zhong, Xian-Hui
2016-01-01
Stimulated by the recently exciting progress in the observation of new bottomonium states, we study the bottomonium spectrum. To calculate the mass spectrum, we adopted a nonrelativistic screened potential model. The radial Schr\\"{o}dinger equation is solved with the three-point difference central method, where the spin-dependent potentials are dealt with non-perturbatively. With this treatment, the corrections of the spin-dependent potentials to the wavefunctions can be included successfully. Furthermore, we have calculated the electromagnetic transitions of the $nS$, $nP$ ($n\\leq 3$), and $nD$ ($n\\leq 2$) bottomonium states with a nonrelativistic electromagnetic transition operator widely applied to meson photoproduction reactions. Our calculated masses, hyperfine and fine splittings, and electromagnetic transition rates for the bottomonium states are in good agreement with the available experimental data. We hope our study can provide some useful references to determine the properties of the bottomonium st...
Electromagnetic ferrofluid-based energy harvester
Bibo, A.; Masana, R.; King, A.; Li, G. [Nonlinear Vibrations and Energy Harvesting Laboratory (NOVEHL), Department of Mechanical Engineering, Clemson University, Clemson, SC 29634 (United States); Daqaq, M.F., E-mail: mdaqaq@clemson.edu [Nonlinear Vibrations and Energy Harvesting Laboratory (NOVEHL), Department of Mechanical Engineering, Clemson University, Clemson, SC 29634 (United States)
2012-06-25
This Letter investigates the use of ferrofluids for vibratory energy harvesting. In particular, an electromagnetic micro-power generator which utilizes the sloshing of a ferrofluid column in a seismically-excited tank is proposed to transform mechanical motions directly into electricity. Unlike traditional electromagnetic generators that implement a solid magnet, ferrofluids can easily conform to different shapes and respond to very small acceleration levels offering an untapped opportunity to design scalable energy harvesters. The feasibility of the proposed concept is demonstrated and its efficacy is discussed through several experimental studies. -- Highlights: ► A ferrofluid-based electromagnetic energy harvester is proposed and tested. Conformability of fluids offers unique capabilities to design scalable harvesters. ► Power is sensitive to changes in the fluid surface area and external magnetization. ► Device generates 1 microwatt of output power at a base acceleration of 3 m/s{sup 2}.
Effect of electromagnetic waves on human reproduction.
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.
Geant4 Low Energy Electromagnetic Physics
S.Chauvie; G.Depaola; 等
2001-01-01
Geant4 Low Energy Electromagnetic package Provides a precise treatment of electromagnetic interations of particles with matter down to very low energies (250 oV for electrons and photons,<1 keV for hadrons and ions),It includes a veriety of models for the electromagnetic processes of electrons,photons,hadrons and ions,taking into account advance features,such as shell effects and effects due to charge dependence.The comprehensive set of particle types it can handle,the variety of modeling approaches and the extended coverage of energy range make this package a unique tool among Monte Carlo codes on the market,and of relevance to serveral experimental domains in HIEP,astroparticle physics,space science and biomedical studies.
Contribution of Electromagnetic Field to Atomic Spin
DU Tao; LIANG Wen-Feng; WU Xiao-Hua
2011-01-01
We examine the contribution of electromagnetic field to the atomic spin, by adopting two different, both gauge invariant definitions of the electromagnetic angular momentum: →JI≡ ∫ d3x∈0→γ× (→E × →B) and →JII ≡ ∫ d3x(∈0→E × A→⊥ + ∈0Ei→ γ× ▽A⊥i). Notably, at the classical level, J→II gives an exactly null result while →JI gives a finite value.This suggests that JII leads to a simpler and more reasonable picture of the atomic spin, therefore qualifies as a more appropriate definition of the electromagnetic angular momentum. Our observation gives important hint on the delicate issue of gluon contribution to the nucleon spin.
Metamaterial Electromagnetic Superabsorber with Arbitrary Geometries
Jingjing Yang
2010-06-01
Full Text Available The electromagnetic superabsorber that has larger absorption cross section than its real size may be a novel photothermal device with improved solar energy conversion rates. Based on a transformation optical approach, the material parameters for a two-dimensional (2D metamaterial-assisted electromagnetic superabsorber with arbitrary geometries are derived and validated by numerical simulation. We find that for the given geometry size, the absorption cross section of the superabsorber using nonlinear transformation is larger than that using linear transformation. These transformations can also be specialized to the designing the N-sided regular polygonal superabsorber just by changing the contour equation. All theoretical and numerical results validate the material parameters for the 2D electromagnetic superabsorber we have developed.
Exact plane gravitational waves and electromagnetic fields
Montanari, E; Montanari, Enrico; Calura, Mirco
2000-01-01
The behaviour of a "test" electromagnetic field in the background of an exactgravitational plane wave is investigated in the framework of Einstein's generalrelativity. We have expressed the general solution to the de Rham equations asa Fourier-like integral. In the general case we have reduced the problem to aset of ordinary differential equations and have explicitly written the solutionin the case of linear polarization of the gravitational wave. We have expressedour results by means of Fermi Normal Coordinates (FNC), which define the properreference frame of the laboratory. Moreover we have provided some "gedankenexperiments", showing that an external gravitational wave induces measurableeffects of non tidal nature via electromagnetic interaction. Consequently it isnot possible to eliminate gravitational effects on electromagnetic field, evenin an arbitrarily small spatial region around an observer freely falling in thefield of a gravitational wave. This is opposite to the case of mechanicalinteraction invo...
The electromagnetic field in accelerated frames
Maluf, J W
2011-01-01
We develop a geometrical framework that allows to obtain the electromagnetic field quantities in accelerated frames. The frame of arbitrary accelerated observers in space-time is defined by a suitable set of tetrad fields, whose timelike components are adapted to the worldlines of a field of observers. We consider the Faraday tensor and Maxwell's equations as abstract tensor quantities in space-time, and make use of tetrad fields to project the electromagnetic field quantities in the accelerated frames. As an application, plane and spherical electromagnetic waves are projected in linearly accelerated frames in Minkowski space-time. We show that the amplitude, frequency and the wave vector of the plane wave in the accelerated frame vary with time, while the light speed remains constant. We also obtain the variation of the Poynting vector with time in the accelerated frame.
Applications of Advanced Electromagnetics Components and Systems
Kouzaev, Guennadi A
2013-01-01
This text, directed to the microwave engineers and Master and PhD students, is on the use of electromagnetics to the development and design of advanced integrated components distinguished by their extended field of applications. The results of hundreds of authors scattered in numerous journals and conference proceedings are carefully reviewed and classed. Several chapters are to refresh the knowledge of readers in advanced electromagnetics. New techniques are represented by compact electromagnetic–quantum equations which can be used in modeling of microwave-quantum integrated circuits of future In addition, a topological method to the boundary value problem analysis is considered with the results and examples. One extended chapter is for the development and design of integrated components for extended bandwidth applications, and the technology and electromagnetic issues of silicon integrated transmission lines, transitions, filters, power dividers, directional couplers, etc are considered. Novel prospec...
Electromagnetic Field Theory A Collection of Problems
Mrozynski, Gerd
2013-01-01
After a brief introduction into the theory of electromagnetic fields and the definition of the field quantities the book teaches the analytical solution methods of Maxwell’s equations by means of several characteristic examples. The focus is on static and stationary electric and magnetic fields, quasi stationary fields, and electromagnetic waves. For a deeper understanding, the many depicted field patterns are very helpful. The book offers a collection of problems and solutions which enable the reader to understand and to apply Maxwell’s theory for a broad class of problems including classical static problems right up to waveguide eigenvalue problems. Content Maxwell’s Equations - Electrostatic Fields - Stationary Current Distributions – Magnetic Field of Stationary Currents – Quasi Stationary Fields: Eddy Currents - Electromagnetic Waves Target Groups Advanced Graduate Students in Electrical Engineering, Physics, and related Courses Engineers and Physicists Authors Professor Dr.-Ing. Gerd Mrozynski...
Electromagnetic and Gravitational Waves: the Third Dimension
Marsh, Gerald E
2011-01-01
Plane electromagnetic and gravitational waves interact with particles in such a way as to cause them to oscillate not only in the transverse direction but also along the direction of propagation. The electromagnetic case is usually shown by use of the Hamilton-Jacobi equation and the gravitational by a transformation to a local inertial frame. Here, the covariant Lorentz force equation and the second order equation of geodesic deviation followed by the introduction of a local inertial frame are respectively used. It is often said that there is an analogy between the motion of charged particles in the field of an electromagnetic wave and the motion of test particles in the field of a gravitational wave. This analogy is examined and found to be rather limited. It is also shown that a simple special relativistic relation leads to an integral of the motion, characteristic of plane waves, that is satisfied in both cases.
Near-field thermal electromagnetic transport
Edalatpour, Sheila
2015-01-01
A general near-field thermal electromagnetic transport formalism that is independent of the size, shape and number of heat sources is derived. The formalism is based on fluctuational electrodynamics, where fluctuating currents due to thermal agitation are added into Maxwell's curl equations, and is thus valid for heat sources in local thermodynamic equilibrium. Using a volume integral formulation, it is shown that the proposed formalism is a generalization of the classical electromagnetic scattering framework in which thermal emission is implicitly assumed to be negligible. The near-field thermal electromagnetic transport formalism is afterwards applied to a problem involving three spheres exchanging thermal radiation, where all multipolar interactions are taken into account. Using the thermal discrete dipole approximation, it is shown that depending on the dielectric function, the presence of a third sphere slightly affects the spatial distribution of power absorbed compared to the two-sphere case. The forma...
Computational electromagnetics recent advances and engineering applications
2014-01-01
Emerging Topics in Computational Electromagnetics in Computational Electromagnetics presents advances in Computational Electromagnetics. This book is designed to fill the existing gap in current CEM literature that only cover the conventional numerical techniques for solving traditional EM problems. The book examines new algorithms, and applications of these algorithms for solving problems of current interest that are not readily amenable to efficient treatment by using the existing techniques. The authors discuss solution techniques for problems arising in nanotechnology, bioEM, metamaterials, as well as multiscale problems. They present techniques that utilize recent advances in computer technology, such as parallel architectures, and the increasing need to solve large and complex problems in a time efficient manner by using highly scalable algorithms.
Drift effects on electromagnetic geodesic acoustic modes
Sgalla, R. J. F., E-mail: reneesgalla@gmail.com [Institute of Physics, University of São Paulo, São Paulo 05508-900 (Brazil)
2015-02-15
A two fluid model with parallel viscosity is employed to derive the dispersion relation for electromagnetic geodesic acoustic modes (GAMs) in the presence of drift (diamagnetic) effects. Concerning the influence of the electron dynamics on the high frequency GAM, it is shown that the frequency of the electromagnetic GAM is independent of the equilibrium parallel current but, in contrast with purely electrostatic GAMs, significantly depends on the electron temperature gradient. The electromagnetic GAM may explain the discrepancy between the f ∼ 40 kHz oscillation observed in tokamak TCABR [Yu. K. Kuznetsov et al., Nucl. Fusion 52, 063044 (2012)] and the former prediction for the electrostatic GAM frequency. The radial wave length associated with this oscillation, estimated presently from this analytical model, is λ{sub r} ∼ 25 cm, i.e., an order of magnitude higher than the usual value for zonal flows (ZFs)
Understanding geometric algebra for electromagnetic theory
Arthur, John W
2011-01-01
"This book aims to disseminate geometric algebra as a straightforward mathematical tool set for working with and understanding classical electromagnetic theory. It's target readership is anyone who has some knowledge of electromagnetic theory, predominantly ordinary scientists and engineers who use it in the course of their work, or postgraduate students and senior undergraduates who are seeking to broaden their knowledge and increase their understanding of the subject. It is assumed that the reader is not a mathematical specialist and is neither familiar with geometric algebra or its application to electromagnetic theory. The modern approach, geometric algebra, is the mathematical tool set we should all have started out with and once the reader has a grasp of the subject, he or she cannot fail to realize that traditional vector analysis is really awkward and even misleading by comparison"--Provided by publisher.
Apparatus for processing electromagnetic radiation and method
Gatewood, George D. (Inventor)
1983-01-01
Measuring apparatus including a ruled member having alternate transparent and opaque zones. An optical coupler connecting the ruled member with electromagnetic radiation-conversion apparatus. The conversion apparatus may include a photomultiplier and a discriminator. Radiation impinging on the ruled member will, in part, be converted to electrical pulses which correspond to the intensity of the radiation. A method of processing electromagnetic radiation includes providing a member having alternating dark and light zones, establishing movement of the member through the beam of electromagnetic radiation with the dark zones interrupting passage of radiation through the rule, providing an optical coupler to connect a portion of the radiation with a conversion station where the radiation portion is converted into an electrical pulse which is related to the intensity of the radiation received at the conversion station. The electrical pulses may be counted and the digitized signals stored or permanently recorded to produce positional information.
Electromagnetic THz Radiation Modeling by DPSM
Rahani, Ehsan Kabiri; Kundu, Tribikram
2012-03-01
THz or T-ray imaging and spectroscopy are becoming increasingly popular nondestructive evaluation techniques for damage detection and characterization of materials. In order to understand the interaction between the T-ray electromagnetic waves and dielectric media a reliable model of electromagnetic wave propagation through dielectric materials must be developed. A recently developed semi-analytical method called the distributed point source method (DPSM) is extended to model electromagnetic wave propagation in THz range. Since T-ray signals generated by emitters or sources are close to Gaussian beams, the DPSM modeling is carried out for Gaussian beams generated by finite sized emitters. The DPSM generated results are compared with the analytical and experimental results. T-ray propagation in layered structures in absence of any anomaly and the interaction between the Gaussian beam and the spherical scatterer are also investigated.
Conducted Electromagnetic Interference (EMI) in Smart Grids
Smolenski, Robert
2012-01-01
As power systems develop to incorporate renewable energy sources, the delivery systems may be disrupted by the changes involved. The grid’s technology and management must be developed to form Smart Grids between consumers, suppliers and producers. Conducted Electromagnetic Interference (EMI) in Smart Grids considers the specific side effects related to electromagnetic interference (EMI) generated by the application of these Smart Grids. Conducted Electromagnetic Interference (EMI) in Smart Grids presents specific EMI conducted phenomena as well as effective methods to filter and handle them once identified. After introduction to Smart Grids, the following sections cover dedicated methods for EMI reduction and potential avenues for future development including chapters dedicated to: •potential system services, •descriptions of the EMI spectra shaping methods, •methods of interference voltage compensation, and theoretical analysis of experimental results. By focusing on these key aspects, Conducted El...
Ultra-Wideband, Short Pulse Electromagnetics 9
Rachidi, Farhad; Kaelin, Armin; Sabath, Frank; UWB SP 9
2010-01-01
Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-wideband Short-Pulse Electromagnetics 9 presents selected papers of deep technical content and high scientific quality from the UWB-SP9 Conference, which was held from July 21-25, 2008, in Lausanne, Switzerland. The wide-ranging coverage includes contributions on electromagnetic theory, time-domain computational techniques, modeling, antennas, pulsed-power, UWB interactions, radar systems, UWB communications, and broadband systems and components. This book serves as a state-of-the-art r...
Optimization design of electromagnetic shielding composites
Qu, Zhaoming; Wang, Qingguo; Qin, Siliang; Hu, Xiaofeng
2013-03-01
The effective electromagnetic parameters physical model of composites and prediction formulas of composites' shielding effectiveness and reflectivity were derived based on micromechanics, variational principle and electromagnetic wave transmission theory. The multi-objective optimization design of multilayer composites was carried out using genetic algorithm. The optimized results indicate that material parameter proportioning of biggest absorption ability can be acquired under the condition of the minimum shielding effectiveness can be satisfied in certain frequency band. The validity of optimization design model was verified and the scheme has certain theoretical value and directive significance to the design of high efficiency shielding composites.
Program For Displaying Computed Electromagnetic Fields
Hom, Kam W.
1995-01-01
EM-ANIMATE computer program specialized visualization displays and animates output data on near fields and surface currents computed by electromagnetic-field program - in particular MOM3D (LAR-15074). Program based on windows and contains user-friendly, graphical interface for setting viewing options, selecting cases, manipulating files, and like. Written in FORTRAN 77. EM-ANIMATE also available as part of package, COS-10048, includes MOM3D, IRIS program computing near-field and surface-current solutions of electromagnetic-field equations.
The power and beauty of electromagnetic fields
Morgenthaler, Frederic R
2011-01-01
Unique, multi-level textbook is adaptable to introductory, intermediate, and advanced levels This revolutionary textbook takes a unique approach to electromagnetic theory, comparing both conventional and modern theories. It explores both the Maxwell-Poynting representation as well as the Alternate representation, which the author demonstrates is generally simpler and more suitable for analyzing modern electromagnetic environments. Throughout the text, students and researchers have the opportunity to examine both of these theories and discover how each one can be applied to solve problems.
Terrestrial propagation of long electromagnetic waves
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
Freehand biopsy guided by electromagnetic needle tracking
Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann
2011-01-01
To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking.......To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....
Antenna Miniaturization in Complex Electromagnetic Environments
Zhang, Jiaying
. Moreover, the modified Wheeler cap method for measurements of small antennas in complex environments is further developed. A cable-free impedance and gain measurement technique for electrically small antennas is also proposed. The electromagnetic model of this technique is derived by using the spherical...... wave expansion, and it is valid for arbitrary electrically small AUT at arbitrary distances between the probe and AUT. The whole measurement setup is modeled by the cascade of three coupled multipleort networks. The electromagnetic model, the simulation results, and the obtained measurement results...
Freehand biopsy guided by electromagnetic needle tracking
Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann
2011-01-01
To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking.......To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....
Fundamentals of electromagnetics 2 quasistatics and waves
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
Electromagnetic field standards and exposure systems
Grudzinski, Eugeniusz
2013-01-01
When measuring electromagnetic fields (EMF), there are multiple factors that affect accuracy. Everything from proper instrument calibration, to external environmental factors, and even the competence and training of the instrument operator can bring precision into question. This book discusses factors that limit accuracy of electromagnetic field standards. These standards are one of the least accurate among the standards of physical magnitudes. They limit the accuracy of the EMF measurements, as well as the accuracy of the standards' use as exposure systems in a wide range of experiments in el
Intercode comparison of gyrokinetic global electromagnetic modes
Görler, T.; Tronko, N.; Hornsby, W. A.; Bottino, A.; Kleiber, R.; Norscini, C.; Grandgirard, V.; Jenko, F.; Sonnendrücker, E.
2016-07-01
Aiming to fill a corresponding lack of sophisticated test cases for global electromagnetic gyrokinetic codes, a new hierarchical benchmark is proposed. Starting from established test sets with adiabatic electrons, fully gyrokinetic electrons, and electrostatic fluctuations are taken into account before finally studying the global electromagnetic micro-instabilities. Results from up to five codes involving representatives from different numerical approaches as particle-in-cell methods, Eulerian and Semi-Lagrangian are shown. By means of spectrally resolved growth rates and frequencies and mode structure comparisons, agreement can be confirmed on ion-gyro-radius scales, thus providing confidence in the correct implementation of the underlying equations.
Implementation of Computational Electromagnetic on Distributed Systems
无
2002-01-01
Now the new generation of technology could raise the bar for distributed computing. It seems to be a trend to solve computational electromagnetic work on a distributed system with parallel computing techniques. In this paper, we analyze the parallel characteristics of the distributed system and the possibility of setting up a tightly coupled distributed system by using LAN in our lab. The analysis of the performance of different computational methods, such as FEM, MOM, FDTD and finite difference method, are given. Our work on setting up a distributed system and the performance of the test bed is also included. At last, we mention the implementation of one of our computational electromagnetic codes.
A top-face-swav electromagnetic micromotor
Jingqiu Liang(梁静秋); Lijun Wang(王立军); Zichun Le(乐孜纯); Jinsong Yao(姚劲松); Zhiyong Wu(吴志勇); Hongguang Jia(贾宏光); Yihui Wu(吴一辉); Zhi Jia(贾智); Qiongying Lü(吕琼莹); Ming Xuan(宣明)
2003-01-01
In this paper, the structure of a top-face-sway electromagnetic micromotor and its principle, fabrication andperformance are introduced. A combination of the electromagnetic actuating and the planetary reducingprovides this micromotor an advantage of low rotational speed and high torque. In addition, since a flexiblecoupling absorbs the sway and only outputs rotation, it gives this micromotor a balanced output. Thedimension of the micromotor is 5 mm. Its rotation speed has a range of 20 - 860 rpm, and its drivingcurrent is 300 mA. The output torque of the micromotor is measured to be 13.0 μNm.
Propulsion Through Electromagnetic Self-Sustained Acceleration
Petkov, V B
1999-01-01
As is known the repulsion of the volume elements of an uniformly accelerating charge or a charge supported in an uniform gravitational field accounts for the electromagnetic contribution to the charge's inertial and gravitational mass, respectively. This means that the mutual repulsion of the charge's volume elements resists its accelerated motion. Conversely, the effect of electromagnetic attraction of opposite charges results in a self-sustaining accelerated motion of the charges provided that they have been initially uniformly accelerated or supported in an uniform gravitational field. The significance of this effect is that it constitutes a possibility for altering inertia and gravitation.
Electromagnetic continuous casting project: Final report
Battles, J.E.; Rote, D.M.; Misra, B.; Praeg, W.F.; Hull, J.R.; Turner, L.R.; Shah, V.L.; Lari, R.J.; Gopalsami, N.; Wiencek, T.
1988-10-01
This report describes the work on development of an electromagnetic casting process for steel, which was carried out at Argonne National Laboratory between January 1985 and December 1987. This effort was concerned principally with analysis and design work on magnet technology, liquid metal feed system, coolant system, and sensors and process controllers. Experimentation primarily involved (1) electromagnetic studies to determine the conditions and controlling parameters for stable levitation and (2) feed-system studies to establish important parameters that control and influence fluid flow from the liquid metal source to the caster. 73 refs., 91 figs., 11 tabs.
Angular momentum and the electromagnetic top
GIANFRANCO SPAVIERI; GEORGE T GILLIES
2016-08-01
The electric charge–magnetic dipole interaction is considered. If $\\Gamma_{\\rm em}$ is the electromagnetic and $\\Gamma_{\\rm mech}$ the mechanical angular momentum, the conservation law for the total angular momentum $\\Gamma_{\\rm tot}$ holds: $\\Gamma_{\\rm tot}$ =$\\Gamma_{\\rm em}$ + $\\Gamma_{\\rm mech}$ = ${\\rm const.}$, but when the dipole moment varies with time, $\\Gamma_{\\rm mech}$ is not conserved. We show that the non-conserved $\\Gamma_{\\rm mech}$ of such a macroscopic isolated system might be experimentally observable. With advanced technology, the strength of the interaction hints to the possibility of novel applications for gyroscopes, such as the electromagnetic top.
Advanced electromagnetism foundations, theory and applications
Barrett, Terence W
1995-01-01
Advanced Electromagnetism: Foundations, Theory and Applications treats what is conventionally called electromagnetism or Maxwell's theory within the context of gauge theory or Yang-Mills theory. A major theme of this book is that fields are not stand-alone entities but are defined by their boundary conditions. The book has practical relevance to efficient antenna design, the understanding of forces and stresses in high energy pulses, ring laser gyros, high speed computer logic elements, efficient transfer of power, parametric conversion, and many other devices and systems. Conventional electro
The Electromagnetic Duality Formulation of Geometric Phases
Zhang, Yuchao; Li, Kang
2015-06-01
This paper focuses on the electromagnetic(EM) duality formulation of geometric phases of Aharonov-Bohm(A-B) effect and Aharonov-Casher(A-C) effect. Through the two four-vector potential formulation of electromagnetic theory, we construct a EM duality formulation for both A-B effect and A-C effect. The He-McKellar-Wilkens(HMW) effect is included as a EM duality counterpart of the A-C effect, and also the EM duality counterpart of the A-B effect is also predicted.
Electromagnetic measurements in the near field
Bienkowski, Pawel
2012-01-01
This book is devoted to the specific problems of electromagnetic field (EMF) measurements in the near field and to the analysis of the main factors which impede accuracy in these measurements. It focuses on careful and accurate design of systems to measure in the near field based on a thorough understanding of the fundamental engineering principles and on an analysis of the likely system errors. Beginning with a short introduction to electromagnetic fields with an emphasis on the near field, it them presents methods of EMF measurements in near field conditions. It details the factors limiting
Electromagnetic System Design and Visual Simulation
ZHANGJing-shu; CHENDe-gui; NIUChun-ping
2004-01-01
An electromagnet design system is developed using Visual C++ language and OpenGL technology to visualize parametric 3D model. The system consists of primary design,optimization design, dynamic and static characteristics, and visual simulation. All empirical parameters and curves used in design process are stored in database. Through human-computer interactions, an electromagnetic system can be designed conveniently with the results and characteristics curves displayed in graphic model. Using this system can greatly shorten the process of product design, and the results satisfy technical requirements.
Electromagnetic Stress Tensor in Ponderable Media
Mansuripur, Masud
2014-01-01
We derive an expression for the Maxwell stress tensor in a magnetic dielectric medium specified by its permittivity "epsilon" and permeability "mu." The derivation proceeds from the generalized form of the Lorentz law, which specifies the force exerted by the electromagnetic E and H fields on the polarization P and magnetization M of ponderable media. Our stress tensor differs from the well-known tensors of Abraham and Minkowski, which have been at the center of a century-old controversy surrounding the momentum of the electromagnetic field in transparent materials.
Willumsen, H. (Crone and Koch, Viborg (Denmark))
1990-08-01
In most landfills, the refuse deposit usually has a high content of organic matter consisting of a mixture of household, industrial and garden waste. Immediately after the refuse has been placed in the landfill, aerobic decomposition of the organic waste begins. Once the oxygen has been exhausted, anaerobic decomposition begins. 'Biogas' is produced which has a methane content of approximately 50% and can be used as a fuel. The exploitation of landfill gas for energy purposes was initiated in the USA around 1975 and later in Europe. A landfill gas plant consists of a recovery system and a production system. A recovery system can consist of vertical perforated pipe wells, horizontal perforated pipes or ditches, or membrane covers to collect the generated gas. Under normal conditions it will not be necessary to process the gas except for the removal of water and other impurities (e.g. solid particles) if the gas is to be used in a boiler or engine. In the USA most often only power is produced, whereas in Europe the waste heat is normally exploited, making the plant function as a combined power and heating plant. It is also possible to upgrade the landfill gas to a methane content of nearly 100, after which it can be distributed with natural gas. There are several such plants in the USA. 8 refs., 6 figs., 6 tabs.
WANG Hui; LI Ting-ju; JIN Jun-ze
2005-01-01
In order to estimate the feasibility of electromagnetic casting (EMC) for different metals, a mathematical model named the electromagnetic dimensionless number (EMDN) was presented, and its validity was proved by the experiments of aluminum and Sn-3 %Pb alloy. From the experiment and the analysis of EMDN it can be concluded that the EMC of steel can be attained only when the magnetic flux density is larger than 0.09 T, while that required for aluminum is only 0. 04 T. The mathematical expression of the electromagnetic dimensionless number was given out.
Electromagnetic signatures of supermassive black hole binaries resolved by PTAs
Tanaka, Takamitsu L
2013-01-01
Pulsar timing arrays (PTAs) may eventually be able to detect not only the stochastic gravitational-wave (GW) background of SMBH binaries, but also individual, particularly massive binaries whose signals stick out above the background. In this contribution, we discuss the possibility of identifying and studying such `resolved' binaries through their electromagnetic emission. The host galaxies of such binaries are themselves expected to be also very massive and rare, so that out to redshifts z~2 a unique massive galaxy may be identified as the host. At higher redshifts, the PTA error boxes are larger and may contain as many as several hundred massive-galaxy interlopers. In this case, the true counterpart may be identified, if it is accreting gas efficiently, as an active galactic nucleus (AGN) with a peculiar spectrum and variable emission features. Specifically, the binary's tidal torques expel the gas from the inner part of the accretion disk, making it unusually dim in X-ray and UV bands and in broad optical...
Effects of thermal motion on electromagnetically induced absorption
Tilchin, E; Wilson-Gordon, A D; 10.1103/PhysRevA.83.053812
2011-01-01
We describe the effect of thermal motion and buffer-gas collisions on a four-level closed N system interacting with strong pump(s) and a weak probe. This is the simplest system that experiences electromagnetically induced absorption (EIA) due to transfer of coherence via spontaneous emission from the excited to ground state. We investigate the influence of Doppler broadening, velocity-changing collisions (VCC), and phase-changing collisions (PCC) with a buffer gas on the EIA spectrum of optically active atoms. In addition to exact expressions, we present an approximate solution for the probe absorption spectrum, which provides physical insight into the behavior of the EIA peak due to VCC, PCC, and wave-vector difference between the pump and probe beams. VCC are shown to produce a wide pedestal at the base of the EIA peak, which is scarcely affected by the pump-probe angular deviation, whereas the sharp central EIA peak becomes weaker and broader due to the residual Doppler-Dicke effect. Using diffusion-like e...
Research of an electromagnetically actuated spark gap switch.
Zhang, Tianyang; Chen, Dongqun; Liu, Jinliang; Wang, Yuwei; Qiu, Yongfeng
2013-11-01
As an important part of pulsed power systems, high-voltage and high-current triggered spark gap switch and its trigger system are expected to achieve a compact structure. In this paper, a high-voltage, high-current, and compact electromagnetically actuated spark gap switch is put forward, and it can be applied as a part of an intense electron-beam accelerator (IEBA). A 24 V DC power supply is used to trigger the switch. The characteristics of the switch were measured for N2 when the gas pressure is 0.10-0.30 MPa. The experimental results showed that the voltage/pressure (V/p) curve of the switch was linear relationship. The operating ranges of the switch were 21%-96%, 21%-95%, 21%-95%, 19%-95%, 17%-95%, and 16%-96% of the switch's self-breakdown voltage when the gas pressures were 0.10, 0.14, 0.18, 0.22, 0.26, and 0.30 MPa, respectively. The switch and its trigger system worked steadily and reliably with a peak voltage of 30 kV, a peak current of 60 kA in the IEBA when the pressure of N2 in the switch was 0.30 MPa.
Electromagnetic modes in cold magnetized strongly coupled plasmas
Tkachenko, I. M.; Ortner, J.; Rylyuk, V. M.
1999-01-01
The spectrum of electromagnetic waves propagating in a strongly coupled magnetized fully ionized hydrogen plasma is found. The ion motion and damping being neglected, the influence of the Coulomb coupling on the electromagnetic spectrum is analyzed.
On the gravitational fields created by the electromagnetic waves
Loinger, A.; Marsico, T.
2011-01-01
We show that the Maxwell equations describing an electromagnetic wave are a mathematical consequence of the Einstein equations for the same wave. This fact is significant for the problem of the Einsteinian metrics corresponding to the electromagnetic waves.
Applied Computational Electromagnetics Society Journal / Volume 17, Number 3
Elsherbeni, Atef Z.
2002-01-01
The Applied Computational Electromagnetics Society Journal hereinafter known as the ACES Journal is devoted to the exchange of information in computational electromagnetics, to the advancement of the state-of-the-art, and to the promotion of related technical activities.
Guiguet, J.C. [Agence Nationale des Frequences (ANFR), 94 - Maisons Alfort (France); Dodinot, B.; Sadoul, N.; Blangy, H. [Centre Hospitalier Universitaire Nancy-Brabois, Clinique Cardiologique, 54 - Vandoeuvre Brabois (France); Nadi, M.; Hedjiedj, A.; Schmitt, P. [Universite Henri Poincare-Nancy, Lab. d' Instrumentation Electronique de Nancy, Faculte des Sciences, 54 - Vandoeuvre les Nancy (France); Joly, L.; Dodinot, B.; Aliot, E. [Centre Hospitalier Universitaire Nancy-Brabois, Service de Cardiologie, 54 - Vandoeuvre-les-Nancy (France); Silny, J. [Aachen University (Germany); Franck, R.; Himbert, C.; Hidden-Lucet, F.; Petitot, J.C.; Fontaine, G. [Hopital Pitie-Salpetriere, Institut de Cardiologie, Service de Rythmologie, 75 - Paris (France); Souques, M.; Lambrozo, J. [Electricite de France (EDF-Gaz de France), Service des Etudes Medicales, 75 - Paris (France); Magne, I.; Bailly, J.M. [Electricite de France (EDF-Gaz de France), Div. Recherche Developpement, 77 - Moret sur Loing (France); Trigano, J.A. [Centre Hospitalier Universitaire, Hopital Nord, 13 - Marseille (France); Burais, N. [CEGELY, Ecole Centrale de Lyon, 69 - Ecully (France); Gaspard, J.Y. [Magtech, 69 - Ecully (France); Andrivet, Ph. [Societe Medtronic France, 92 - Boulogne-Billancourt (France)
2004-07-01
Presentation of electromagnetic sources constituted by various radio transmitters contributing to different radio communication services in the environment. Results of a measures campaign to assess the electromagnetic field in the close neighbourhood of various stations. Analysis by frequency domains. (author)
Farahan, E.; Eudaly, J.P.
1978-10-01
This evaluation provides performance and cost data for commercially available simple- and regenerative-cycle gas turbines. Intercooled, reheat, and compound cycles are discussed from theoretical basis only, because actual units are not currently available, except on a special-order basis. Performance characteristics investigated include unit efficiency at full-load and off-design conditions, and at rated capacity. Costs are tabulated for both simple- and regenerative-cycle gas turbines. The output capacity of the gas turbines investigated ranges from 80 to 134,000 hp for simple units and from 12,000 to 50,000 hp for regenerative units.