A MULTILAYER CONDUCTING EARTH IN THE FIELD OF PLANE WAVES

1966 ◽  
Vol 44 (1) ◽  
pp. 81-89
Author(s):  
H. W. Dosso
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Electromagnetic Waves ◽  
Plane Waves ◽  
Conducting Medium ◽  
Continuous Change ◽  
Electric And Magnetic Field ◽  
Thick Layers

A multilayer plane conducting earth in the field of plane electromagnetic waves is treated. Each of several thick layers is divided into a sufficient number of sublayers, with changing conductivity, to represent to a good approximation a continuous change in conductivity. Expressions for the amplitudes and phases of the electric- and magnetic-field components are obtained and evaluated for several different conductivity distributions. The conductivities and frequencies considered are of interest in geophysics. The results obtained indicate that the amplitudes and phases of the varying electromagnetic-field components are affected strongly by the inhomogeneity of the conducting medium.

scholarly journals A Physically-Motivated Quantisation of the Electromagnetic Field on Curved Spacetimes

Entropy ◽  
2019 ◽  
Vol 21 (9) ◽  
pp. 844
Author(s):  
Ben Maybee ◽  
Daniel Hodgson ◽  
Almut Beige ◽  
Robert Purdy
Keyword(s):  
Magnetic Field ◽  
Field Theory ◽  
Quantum Field Theory ◽  
Electromagnetic Field ◽  
Minkowski Space ◽  
Unruh Effect ◽  
Quantum Field ◽  
Rindler Space ◽  
Electric And Magnetic Field ◽  
Curved Spacetimes

Recently, Bennett et al. (Eur. J. Phys. 37:014001, 2016) presented a physically-motivated and explicitly gauge-independent scheme for the quantisation of the electromagnetic field in flat Minkowski space. In this paper we generalise this field quantisation scheme to curved spacetimes. Working within the standard assumptions of quantum field theory and only postulating the physicality of the photon, we derive the Hamiltonian, H ^ , and the electric and magnetic field observables, E ^ and B ^ , respectively, without having to invoke a specific gauge. As an example, we quantise the electromagnetic field in the spacetime of an accelerated Minkowski observer, Rindler space, and demonstrate consistency with other field quantisation schemes by reproducing the Unruh effect.

scholarly journals Effect of A Superstrate on On-Head Matched Antennas for Biomedical Applications

Electronics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1099
Author(s):  
Md Rokunuzzaman Robel ◽  
Asif Ahmed ◽  
Akram Alomainy ◽  
Wayne S. T. Rowe
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Performance Improvement ◽  
Direct Contact ◽  
Biomedical Applications ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Conducting Layer ◽  
Electric And Magnetic Field ◽  
Biomedical Diagnosis

The effect of using a superstrate dielectric layer on an on-head matched antenna for biomedical diagnosis applications is investigated. Two on-head matched antennas are considered with different length meandered lines ensuring operation around 0.9 GHz frequency. The first antenna’s conductive radiating structure is in direct contact with the head phantom, whereas the second one utilises a 0.5 mm thick superstrate layer on top of the conducting layer as a buffer. The lateral dimensions of both antennas are held constant at 30 × 30 mm2. The electric and magnetic field distribution is analysed and the power penetration, 50 mm inside the head phantom, is derived from the electromagnetic field surrounding the antennas. Both homogeneous and inhomogeneous head phantoms are considered while evaluating the antennas in terms of their reflection coefficient, current distribution, electric field, magnetic field, specific absorption rate (SAR) and power penetration inside the head. The antennas are fabricated and measured utilizing an inhomogeneous phantom to validate the proposed performance improvement using a superstrate. It is shown that the superstrate antenna achieves a ~8 dB increase in power penetration inside the head phantom along with a 0.0731 W/kg decrease in SAR compared to the antenna without a superstrate.

Propagation of electromagnetic waves in circular rods in torsion

1963 ◽  
Vol 255 (1059) ◽  
pp. 389-416 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Constitutive Equations ◽  
Electromagnetic Waves ◽  
Linear Functions ◽  
Static Deformation ◽  
Polynomial Functions ◽  
Electric And Magnetic Field ◽  
Speed Of Propagation ◽  
Propagation Of Waves

Invariance considerations are employed to write down constitutive equations governing the propagation of electromagnetic waves in isotropic materials with a centre of symmetry which are subject to a static deformation. It is assumed that the dielectric displacement and magnetic induction vectors are linear functions of the electric and magnetic field intensities, respectively, but are general polynomial functions in the quantities which specify the deformation. The theory is employed to examine propagation along circular cylindrical rods in torsion. Rotating waves are produced whose speed of propagation and rate of rotation depend upon the magnitude of the deformation and the properties of the material. The nature of these waves is examined for the general case where there is no restriction either upon the amount of torsion or upon the magnitude of the effect. When the amount of torsion, or the dependence of the effect upon deformation is small, solutions can be obtained based upon those for the propagation of waves in undeformed materials.

A semianalytical solution for the propagation of electromagnetic waves in 3‐D lossy orthotropic media

Geophysics ◽  
2001 ◽  
Vol 66 (4) ◽  
pp. 1141-1148 ◽  
Author(s):  
José M. Carcione ◽  
Fabio Cavallini
Keyword(s):  
Magnetic Field ◽  
Plane Wave ◽  
Electromagnetic Waves ◽  
Plane Waves ◽  
Computer Experiment ◽  
Transverse Magnetic ◽  
Wave Analysis ◽  
Helmholtz Equations ◽  
Magnetic Surfaces ◽  
Time Histories

We derive an analytical solution for electromagnetic waves propagating in a 3‐D lossy orthotropic medium for which the electric permittivity tensor is proportional to the magnetic permeability tensor. The solution is obtained through a change of coordinates that transforms the spatial differential operator into a pure Laplace operator and the differential equations for the electric and magnetic field components into pure Helmholtz equations. A plane‐wave analysis gives the expression of the slowness and attenuation surfaces as a function of frequency and propagation direction. The transverse electric and transverse magnetic surfaces degenerate to one repeated sheet so that, in any direction, the two differently polarized plane waves have the same slowness. A computer experiment with realistic geophysical parameters has shown that the anisotropic propagation and dissipation properties emerging from plane‐wave analysis agree with the different time histories of the magnetic field computed at a number of representative receiver locations.

Research on Frequency Electromagnetic Field of Parallel Transmission Line

2014 ◽  
Vol 986-987 ◽  
pp. 1992-1995
Author(s):  
Hong Ying Cao ◽  
Bo Tang ◽  
You Xian Peng ◽  
Yu Li ◽  
Bin Chen
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Transmission Line ◽  
Transmission Lines ◽  
The State ◽  
National Standards ◽  
Power Lines ◽  
Three Gorges ◽  
Parallel Transmission ◽  
Electric And Magnetic Field

At present the study mainly for frequency electromagnetic field which is based on a single transmission line meanwhile the value must be in line with the requirements of the workers in the country frequency electromagnetic field. However, for parallel transmission line the maximum of frequency electromagnetic field is still to meet the provisions of the state, therefore in this paper studied the parallel transmission lines. Taking the multiple parallel power lines of China Three Gorges University as an example, the values of electric and magnetic field are calculated and the electromagnetic field is measured based on National standards. Then, compare the measured value with theoretical value, verified the correctness of the superposition algorithm.

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.

The propagation of magneto-thermo-viscoelastic plane waves in a parallel union of the Kelvin and Maxwell bodies

1971 ◽  
Vol 70 (2) ◽  
pp. 343-350 ◽  
Author(s):  
D. S. Chandrasekhariah
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Electromagnetic Field ◽  
Wave Propagation ◽  
Thermal Field ◽  
Plane Waves ◽  
Viscoelastic Body ◽  
Longitudinal Component ◽  
Transverse Component ◽  
Wave Travel

AbstractThe propagation of plane waves in a viscoelastic body representing a parallel union of the Kelvin and Maxwell bodies placed in a magneto-thermal field is investigated. It is shown that the longitudinal component of the wave is in general coupled with a transverse component and the wave travels in two families. In particular if the primary magnetic field is either parallel or perpendicular to the direction of wave propagation, the three components of the wave travel unlinked, with either the longitudinal component or the transverse components unaffected by the presence of the electromagnetic field. If the electrical conductivity of the solid is infinite the effect of the primary magnetic field is to increase the values of the material constants. The effect of wave propagation on magnetic permeability is equivalent to an anisotropic rescaling of the primary magnetic field. Some of the results obtained in the earlier works are obtained as particular cases of the more general results derived here.

scholarly journals Eigenwave spectra of a solid-state plasma cylinder in a strong longitudinal magnetic field

2021 ◽  
Vol 26 (2) ◽  
pp. 37-45
Author(s):  
Y. Averkov ◽  
◽  
Y. Prokopenko ◽  
V. Yakovenko ◽  
◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Solid State ◽  
Electromagnetic Waves ◽  
Surface Current ◽  
Electron Mass ◽  
Plasma Cylinder ◽  
Field Methods ◽  
Phase Velocities ◽  
State Plasma

Subject and Purpose. Eigenwave studies of various bounded structures make a prolific line of investigation in both modern radiophysics and solid-state and functional electronics. Conducting solids demonstrating plasma (semiconductor) properties attract particular attention. Owing to the high conductivity of semiconductors (as it is inversely proportional to the charge carrier effective mass that is smaller than the free electron mass), interest exists in propagation features of slow elliptical-polarization electromagnetic waves – helicons – in magnetized semiconductor waveguides. The present work aims to determine eigenwave spectra of a solid-state plasma cylinder in a strong constant concentric magnetic field. Methods and Methodology. The eigenwave theoretical study of a magnetoplasma cylinder in the free space is conducted in terms of Maxwell's equations. The motion equation of conduction electrons of a solid-state plasma is adopted with quasi-stationarity electromagnetic field conditions satisfied. The collision frequency of majority charge carriers is assumed substantially less than their cyclotron frequency. Results. The dispersion equation of a cylindrical solid-state plasma (semiconductor) waveguide has been obtained. It has been shown that a collisionless magnetoplasma waveguide supports propagation of bulk and surface helicons. The propagation is accompanied by the surface current flowing lengthways cylinder components. Charged particle collisions destroy the surface current and initiate additional (to helicons) H-type hybrid waves such that their phase velocities coincide with phase velocities of the helicons. It has been found that the nonreciprocity effect holds for the waveguide eigenwaves having identical field distribution structures but different azimuthal propagation directions, and it also does as soon as the external magnetic field changes its sense. Conclusion. The research results have deepened our understanding of physical properties of bounded structures with plasma-like filling media. More systematization has been added to the knowledge of eigenwave behavior of these structures in a quasi-stationarity electromagnetic field.

scholarly journals Nature of Energy Interactions

2020 ◽  
Vol 5 (6) ◽  
pp. 1461-1470
Author(s):  
Cynelle Olívia de Souza
Keyword(s):  
Magnetic Field ◽  
Kinetic Energy ◽  
Thermal Energy ◽  
Electromagnetic Waves ◽  
Second Harmonic ◽  
Intimate Relationship ◽  
Subatomic Particles ◽  
Electric And Magnetic Fields ◽  
Electric And Magnetic Field ◽  
Intrinsic Kinetic

Electromagnetic waves have an electric and magnetic field. There is an intimate relationship between these two fields and in this present work we adopt the theory that subatomic particles, here being considered neutrinos, can carry the thermal energy calculated through intrinsic kinetic energy. The field of neutrinos determined here may be responsible for the formation of the second harmonic, recently discovered, in which highly energetic electromagnetic waves, in the order of terahertz, excite superconducting electrons. Theories related to the electron and the electric and magnetic fields were also addressed, as their nature is fundamental to the understanding of electromagnetic waves, the interaction between them and the broad effects on nature.

THE MAGNETIC FIELD AT THE SURFACE OF A STRATIFIED FLAT CONDUCTOR IN THE FIELD OF PLANE WAVES WITH APPLICATION TO GEOPHYSICS

1962 ◽  
Vol 40 (11) ◽  
pp. 1583-1592 ◽  
Author(s):  
H. W. Dosso
Keyword(s):  
Magnetic Field ◽  
Surface Layer ◽  
Electromagnetic Waves ◽  
Plane Waves ◽  
Geomagnetic Variations ◽  
Wide Range ◽  
The Magnetic Field

The problem of plane electromagnetic waves incident on a stratified flat conductor is considered. Expressions for the amplitude and phase of the components of the resultant magnetic field at the surface of the conductor are obtained and evaluated for a wide range of frequencies, conductivities, surface layer depths, and angles of incidence. The frequencies f = 10−3 to 103 cycles/sec and the conductivities σ = 10−11 to 10−16 emu considered are of interest in studying geomagnetic variations.

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