scholarly journals XI. On the forces, stresses, and fluxes of energy in the electromagnetic field

1892 ◽  
Vol 183 ◽  
pp. 423-480 ◽  
Keyword(s):  
Electromagnetic Field ◽  
Experimental Work ◽  
Electromagnetic Waves ◽  
Extended Form ◽  
New Era ◽  
True Theory ◽  
Material Bodies ◽  
Primary Medium

1. The remarkable experimental work of late years has inaugurated a new era in the development of the Faraday-Maxwellian theory of the ether, considered as the primary medium concerned in electrical phenomena—electric, magnetic, and electromagnetic. Maxwell’s theory is no longer entirely a paper theory, bristling with unproved possibilities. The reality of electromagnetic waves has been thoroughly demonstrated by the experiments of Hertz and Lodge, Fitzgerald and Trouton, J. J. Thomson, and others; and it appears to follow that, although Maxwell’s theory may not be fully correct, even as regards the ether (as it is certainly not fully comprehensive as regards material bodies), yet the true theory must be one of the same type, and may probably be merely an extended form of Maxwell’s. No excuse is therefore now needed for investigations tending to exhibit and elucidate this theory, or to extend it, even though they be of a very abstract nature. Every part of so important a theory deserves to be thoroughly examined, if only to see what is in it, and to take note of its unintelligible parts, with a view to their future explanation or elimination.

Propagation of ultrashort optical pulses in anisotropic optical media with carbon nanotubes

2021 ◽  
pp. 2150197
Author(s):  
N. N. Konobeeva ◽  
M. B. Belonenko
Keyword(s):  
Carbon Nanotubes ◽  
Electromagnetic Field ◽  
Vector Potential ◽  
Pulse Shape ◽  
Electromagnetic Waves ◽  
Optical Pulses ◽  
Effective Equation ◽  
Ultrashort Optical Pulses ◽  
Optical Media ◽  
Crystal Type

In this paper, we investigate the evolution of electromagnetic waves in a nonlinear anisotropic optical medium with carbon nanotubes (CNTs). Based on Maxwell’s equation, an effective equation is obtained for the vector potential of the electromagnetic field, which takes into account different values of the velocity and polarization with two directions. The dependence of the pulse shape on the crystal type, as well as the angle between the electric field and the CNTs axis is revealed.

The New Messengers

2021 ◽  
pp. 36-52
Author(s):  
Gianfranco Bertone
Keyword(s):  
Gravitational Waves ◽  
Nobel Prize ◽  
Direct Contact ◽  
Thin Shell ◽  
Electromagnetic Waves ◽  
Scientific Community ◽  
The Other ◽  
The Moon ◽  
New Era ◽  
The Universe

I present the momentous discovery of gravitational waves, announced in 2016, starting from a confused Einstein who in 1936 tries to convince the scientific community that gravitational waves cannot exist (!), and then illustrating the extraordinary insights and breakthroughs that led 2017 Nobel Prize winners B. Barish, K. Thorne and R. Weiss to open an entirely new window on the Universe. This achievement has marked the beginning of a new era in science, and upcoming experiments have the potential to truly revolutionize our understanding of the Universe. Accounts of the perception of extra-terrestrial reality with senses beyond sight, such as those offered by astronauts who have been on the Moon, are exceedingly rare. That is hardly unsurprising: touch and taste require direct contact, while hearing and smell operate only over short distances, and are in any case confined to the Earth’s thin shell of atmosphere. Sight, on the other hand, allows us to collect the electromagnetic waves emitted by extraordinarily remote celestial objects.

scholarly journals Analysis on the Influence of Transmission Lines span on Passive Interference in Shortwave

2018 ◽  
Vol 64 ◽  
pp. 05004
Author(s):  
Ying Lu ◽  
Zhibin Zhao ◽  
Jian gong Zhang ◽  
Zheyuan Gan
Keyword(s):  
Electromagnetic Field ◽  
Transmission Line ◽  
Transmission Lines ◽  
Electromagnetic Scattering ◽  
Electromagnetic Waves ◽  
Short Wave ◽  
Critical Distance ◽  
Observation Point ◽  
Radio Station ◽  
Passive Interference

The passive interference of transmission lines to nearby radio stations may affect the effective reception and transmission of radio station signals. Therefore, the accurate calculation of the electromagnetic scattering of transmission lines under the condition of external electromagnetic waves is the basis for determining the reasonable avoidance spacing of the two. For passive stations operating in short-wave frequencies, passive interference is mainly generated by the tower, and span is one of the most significant factors affecting passive interference. This paper uses the method of moments to carry out the passive interference calculations under normal circumstances, expounds the method of calculating the electromagnetic field of transmission line at the same time. And elaborates the method for calculating the electromagnetic field of the transmission line, obtains the space electric field intensity of the transmission line at the same working frequency and space location of the plane wave. Applying the approximate formula to calculate the formula for the span and critical distance between the observation point and the transmission line.

scholarly journals Beam generations of three kinds of charged particles

1991 ◽  
Vol 9 (1) ◽  
pp. 149-165 ◽  
Author(s):  
K. Niu ◽  
P. Mulser ◽  
L. Drska
Keyword(s):  
Electromagnetic Field ◽  
Electron Beam ◽  
Electromagnetic Waves ◽  
Laser Light ◽  
Ion Beam ◽  
Charged Particles ◽  
Leading Edge ◽  
Heavy Ion ◽  
Ion Beams ◽  
Damping Force

Analyses are given for beam generations of three kinds of charged particles: electrons, light ions, and heavy ions. The electron beam oscillates in a dense plasma irradiated by a strong laser light. When the frequency of laser light is high and its intensity is large, the acceleration of oscillating electrons becomes large and the electrons radiate electromagnetic waves. As the reaction, the electrons feel a damping force, whose effect on oscillating electron motion is investigated first. Second, the electron beam induces the strong electromagnetic field by its self-induced electric current density when the electron number density is high. The induced electric field reduces the oscillation motion and deforms the beam.In the case of a light ion beam, the electrostatic field, induced by the beam charge, as well as the electromagnetic field, induced by the beam current, affects the beam motion. The total energy of the magnetic field surrounding the beam is rather small in comparison with its kinetic energy.In the case of heavy ion beams the beam charge at the leading edge is much smaller in comparison with the case of light ion beams when the heavy ion beam propagates in the background plasma. Thus, the induced electrostatic and electromagnetic fields do not much affect the beam propagation.

J. J. Thomson and the Structure of Light

1967 ◽  
Vol 3 (4) ◽  
pp. 362-387 ◽  
Author(s):  
Russell McCormmach
Keyword(s):  
Electromagnetic Field ◽  
Quantum Theory ◽  
Experimental Work ◽  
Electric Force ◽  
The Subject

SynopsisThis essay concerns an aspect of the speculative contributions of J. J. Thomson to a field of physics somewhat removed from that upon which his popular fame and scientific eminence were alike founded. He published a number of statements in the period 1903–1910 advocating a discontinuous structure of the electromagnetic field. His unorthodox conception of the field was based upon the presumed discreteness of Faraday's physical lines of electric force. While his ideas led to significant experimental work, they were not brought together in the form of a completed theory. It was at this same time that the quantum theory was independently evolving notions of a structure of the field, and Thomson's efforts at developing a theory of light were diverted into a protracted criticism of the hypothesis of quanta. In 1924–1936 he returned to the subject of the structure of light, but these latter speculations no longer had much relevance to contemporary physical thought.

Eigenvalues of the axially symmetrical electromagnetic waves along an infinitely long and conductive circular cylinder in a homogeneous magnetoionic medium

1969 ◽  
Vol 47 (11) ◽  
pp. 1159-1166 ◽  
Author(s):  
K. Aoki
Keyword(s):  
Electromagnetic Field ◽  
Circular Cylinder ◽  
Electromagnetic Waves ◽  
Cyclotron Frequency ◽  
Numerical Results ◽  
Complex Conjugate ◽  
Field Frequency ◽  
Radial Propagation

This paper discusses eigenvalues of the electromagnetic field along an infinitely long and conductive circular cylinder imbedded in a magnetoionic medium under assumptions that the medium is lossless and the field frequency is not equal to the cyclotron frequency. It is shown that they are classified into two kinds: (i) k1 and k2 are pure imaginary and (ii) k22 = (complex conjugate of k12), where k1 and k2 are the radial propagation constants and that no eigenvalues exist in the region bounded by [Formula: see text] where ωp and ωc are the plasma and cyclotron frequencies normalized to the field frequency. Some numerical results in the case of (radius of the cylinder/wavelength) [Formula: see text] are also shown.

scholarly journals Using the Carotazh Method to Determine the Electrical Characteristics of the Earth’s Subsoil

2021 ◽  
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Electromagnetic Field ◽  
Surface Impedance ◽  
Electromagnetic Waves ◽  
Dielectric Permeability ◽  
Electrical Characteristics ◽  
Measuring Systems ◽  
The Earth ◽  
The Magnetic Field

Logging is a detailed study of the structure of the well incision by descent and ascent of a geophysical probe. It is often used to determine the electrical conductivity of terrestrial depths. To do this, the sides of the well deepen the electrodes, and they are fed into the depths of a constant electric current. However, if you use natural or artificial electromagnetic waves, it becomes possible to determine the dielectric permeability of terrestrial rocks at depth. To do this, the surface impedance is first measured on the surface of the earth, and then by measuring at a certain frequency of the electromagnetic field in the well hole, the electrical conductivity and dielectric permeability of terrestrial rocks are calculated by fairly simple formulas. Such measurements can be carried out by standard measuring systems, adding only a narrow frame with wire winding to measure the magnetic field.

Predicting Multi-Order Magnetic Polaritons Resonance in SiC Slit Arrays by Mutual Inductor–Inductor–Capacitor Circuit Model

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Yanming Guo ◽  
Bo Xiong ◽  
Yong Shuai
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Waves ◽  
Fdtd Method ◽  
Circuit Model ◽  
Radiative Properties ◽  
Field Calculation ◽  
Thermal Radiative Properties ◽  
Resonance Frequencies ◽  
Lc Circuit ◽  
Calculation Results

Abstract Magnetic polariton (MP) that couples electromagnetic waves with magnetic excitation can be predicted by equivalent inductor–capacitor (LC) circuit model. However, when the resonance frequencies of MP and surface phonon polariton (SPhP) is close, the absorption and transmission peaks predicted by LC circuit model are far different from solving electromagnetic field calculation results. In this work, absorption and transmission enhancements with a SiC slit array are theoretically demonstrated within the SiC phonon absorption band with finite difference time-domain (FDTD) method. The interactions between SPhP and MP are confirmed by electromagnetic field distributions. Mutual inductor–inductor–capacitor (MLC) circuit model is used to predict the multiorder MP resonance conditions, and the coupling between MP and SPhP is treated as a mutual inductor in MLC model. The geometric effects of SiC slit arrays are investigated and MLC circuit model works well. This study may contribute to the design and prediction of thermal radiative properties and micro-/nanostructure metamaterials thermal radiative properties database building.

BIOTECHNOLOGICAL FEATURES OF OBTAINING CO2 EXTRACTS FROM GRAIN AND NUT RAW MATERIALS

2019 ◽  
Author(s):  
А.М. МЕДВЕДЕВ ◽  
К.Ш. САКИБАЕВ
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Waves ◽  
Raw Materials ◽  
Low Frequency ◽  
Extraction Process ◽  
Raw Material ◽  
Grape Seeds ◽  
Before And After ◽  
Extractive Substances ◽  
Vegetable Raw Materials

Разработана технология получения СО2экстрактов с повышенным выходом СО2экстрактивных веществ после предварительной обработки зернового и орехового сырья электромагнитным полем низкой частоты (ЭМП НЧ) 28,36 Гц. Растительное сырье семена амаранта, винограда, расторопши пятнистой, ростки пшеницы, арахис, миндаль, ядра фисташковых и ореха грецкого подвергли измельчению в крупку размером 2 3 мм для дальнейшей обработки на вальцевом станке (d 0,2 мм). Измельченное сырье помещали в радиопрозрачный короб и трижды подвергали воздействию ЭМП НЧ по 20 мин с перерывом по 30 мин. Обработанное электромагнитным полем сырье заключили в сетчатую кассету и загрузили внутрь СО2экстрактора, работающего в докритическом режиме при давлении 6,5 МПа и температуре 22С. Продолжительность процесса экстракции сырья, ч: орехового 4,0 зернового 2,5. Установлено увеличение выхода биокомпонентов в экстракт из орехов и зерна, подвергнутых воздействию электромагнитных волн, по сравнению с контрольными образцами без обработки ЭМП НЧ. Выход СО2экстрактивных веществ из сырья до обработки и после обработки ЭМП НЧ составил, : арахис 8,0 и 14,1 орех грецкий 10,2 и 16,3 семена амаранта 4,7 и 5,4 семена винограда 6,0 и 6,5 соответственно. Концентрация фенольных веществ в экстрактах повысилась на 15, витаминов С и Р на 6,2 и 7,0 соответственно. Применение электромагнитного излучения НЧ привело к сокращению продолжительности экстракции из зернового и орехового сырья в 1,2 раза. A technology has been developed for producing CO2 extracts with an increased yield of CO2 extractives after preliminary processing of grain and nut raw materials with a low frequency electromagnetic field (LF EMF) of 28,36 Hz. Vegetable raw materials amaranth seeds, grapes, milk thistle, wheat germ, peanuts, almonds, pistachio kernels and walnuts kernels were crushed into a grain size of 2 3 mm for further processing on a roller machine (d 0,2 mm). The crushed raw material was placed in a radiotransparent box and exposed to LF EMF three times for 20 min with a break of 30 min. The raw material processed by the electromagnetic field was enclosed in a mesh cassette and loaded inside a CO2 extractor operating in a subcritical mode at a pressure of 6,5 MPa and a temperature of 22C. The duration of the extraction process of raw materials, h: nut 4,0 grain 2,5. An increase in the yield of biocomponents in the extract from nuts and grains exposed to electromagnetic waves was established compared with the control samples without processing the LF EMF. The yield of СО2 extractive substances from the raw materials before and after the treatment of LF EMF was, : peanuts 8,0 and 14,1 walnut 10,2 and 16,3 amaranth seeds 4,7 and 5,4 grape seeds 6,0 and 6,5, respectively. The concentration of phenolic substances in the extracts increased by 15, vitamins C and P by 6,2 and 7,0, respectively. The use of electromagnetic radiation of low frequency led to a reduction in the duration of extraction from grain and nut raw materials by 1,2 times.

Evolution of the polarization of electromagnetic waves in weakly anisotropic inhomogeneous media — a comparison of quasi-isotropic approximations of the geometrical optics method and the Stokes vector formalism

Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Yury Kravtsov ◽  
Bohdan Bieg
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Waves ◽  
Normal Modes ◽  
Geometrical Optics ◽  
Inhomogeneous Media ◽  
Stokes Vector ◽  
Coupled Equations ◽  
Isotropic Approximation ◽  
Total Phase ◽  
Electromagnetic Beams

AbstractThe main methods describing polarization of electromagnetic waves in weakly anisotropic inhomogeneous media are reviewed: the quasi-isotropic approximation (QIA) of geometrical optics method that deals with coupled equations for electromagnetic field components, and the Stokes vector formalism (SVF), dealing with Stokes vector components, which are quadratic in electromagnetic field intensity. The equation for the Stokes vector evolution is shown to be derived directly from QIA, whereas the inverse cannot be true. Derivation of SVF from QIA establishes a deep unity of these two approaches, which happen to be equivalent up to total phase. It is pointed out that in contrast to QIA, the Stokes vector cannot be applied for a polarization analysis of the superposition of coherent electromagnetic beams. Additionally, the ability of QIA to describe a normal modes conversion in inhomogeneous media is emphasized.

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