Radiation Field of a Uniformly Moving Charge in an Anisotropic Medium

1974 ◽  
Vol 29 (5) ◽  
pp. 687-692
Author(s):  
G. P. Sastry ◽  
S. Datta Majumdar
Keyword(s):  
Radiation Field ◽  
Anisotropic Medium ◽  
Point Charge ◽  
Potential Distribution ◽  
Asymptotic Form ◽  
Dielectric Tensor ◽  
Arbitrary Direction ◽  
Hankel Functions ◽  
Anisotropic Fields ◽  
Set Up

Abstract Fourier integrals are set up for the field of a point charge moving uniformly in an arbitrary direction in a uniaxial medium anisotropic in ε only. The integrals break up into several parts two of which yield the ordinary and extraordinary cones with uniform azimuthal potential distribution. The remaining integrals neither contribute to the energy radiated nor affect the size and the shape of the cones, but merely distort the field within the cones. The integrals are evaluated exactly in the non-dispersive case and closed expressions for the potential are obtained. In the dispersive case, the radiation field is determined by using the asymptotic form of the Hankel functions occurring in the integrand. The resulting expressions exhibit the high azimuthal asymmetry characteristic of anisotropic fields. From the expressions derived for a pure dielectric the potential in a doubly anisotropic medium is obtained, without a fresh calculation, by making appropriate substitutions for the coordinates of the field point and the components of the dielectric tensor.

Investigated Effect of Points Charge of the Receptors on the Conduction of Semiconductor Nanowire

2015 ◽  
Vol 1109 ◽  
pp. 167-170
Author(s):  
M. Wesam Al-Mufti ◽  
U. Hashim ◽  
Mijanur Rahman ◽  
Tijjani Adam ◽  
A.H. Azman ◽  
...  
Keyword(s):  
Finite Element ◽  
Oxide Layer ◽  
Point Charge ◽  
Potential Distribution ◽  
Silicon Nanowire ◽  
Comsol Multiphysics ◽  
Functional Layer ◽  
Semiconductor Nanowire ◽  
Finite Element Calculations

The paper reported a study on an effect of the point charge of the bio-interface of a nanowire field biosensor on the conductance of the nanowire, through finite element calculations using COMSOL Multiphysics. A model with 5 layers starting with silicon nanowire of radius 10nm surrounded by a 2-nm oxide layer, and the oxide layer were surrounded by a 5 nm thick functional layer and 2 points charge were considered for this study and last layer is for electrolyte. The results shows that is different voltages with points change is that effected on the conductance of nanowire that is clear from different of potential distribution of point charge.

On the Derivation of the Integral Equation for the Propagation of Light in Dielectric Crystals

1971 ◽  
Vol 49 (10) ◽  
pp. 1384-1395 ◽  
Author(s):  
J. Vlieger
Keyword(s):  
Integral Equation ◽  
Light Wave ◽  
Dipole Moments ◽  
Incident Light ◽  
Phenomenological Theory ◽  
Dipole Interaction ◽  
Dielectric Tensor ◽  
Simple Lattice ◽  
Propagation Of Light ◽  
Set Up

A new derivation is given of the integral equation for the macroscopic polarization set up in a dielectric crystal by an incident light wave. The molecules are assumed to lie on the points of a perfect, simple lattice and to interact only via the retarded dipole–dipole interaction. The derivation is based on a direct averaging of the microscopic equations for the dipole moments induced by the incident wave and the dipole fields. The averaging is a space averaging with a weight function with a width Δ satisfying [Formula: see text], where a is the lattice constant and λ the wavelength of the incident field. The derivation is an application of Nijboer and De Wette's method for the evaluation of lattice sums.In contrast to the more indirect derivation given earlier by Hoek, (i) the present derivation is not based on an expansion in powers of the molecular polarizability, α, so that, e.g., there is no limitation to frequencies outside the resonance regions, and (ii) the integral equation is shown to be valid everywhere in the crystal except in a macroscopically negligible boundary layer of thickness Δ rather than λ. The latter improvement is crucial in the presence of superradiance.The integral equation is shown to be equivalent to the usual wave equation derived from Maxwell's phenomenological theory supplemented by the appropriate constitutive equations. An explicit expression is derived for the frequency dependent dielectric tensor in terms of rapidly convergent lattice sums.

scholarly journals Global system: situation, contemporary tendencies and possible perspectives of the power potential distribution

Geografie ◽  
2009 ◽  
Vol 114 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Martin Hampl
Keyword(s):  
Current Distribution ◽  
Potential Distribution ◽  
Global System ◽  
Global Power ◽  
Distribution Of Power ◽  
Set Up ◽  
Global Systems ◽  
Economic Size

This contribution deals with the set-up of global power differentiation and its contemporary and prospective changes. Primary attention is paid to construction of representative aggregate indicators of power potential on the level of states and of sub-global systems. Into account is taken their territorial, population and economic size and that in a differentiated way (different weights attributed to partial size characteristics). The results confirm the anticipated asymmetry in the distribution of power potential and its shifting among superpowers. Especially emphasized is not only the current distribution of power among states, but above all among supranational systems – including the distinct potential in possibilities of further expansion and integration of sub-global systems.

A new classical theory of electrons. III

1954 ◽  
Vol 223 (1155) ◽  
pp. 438-445 ◽  
Keyword(s):  
Classical Theory ◽  
Point Charge ◽  
Equations Of Motion ◽  
Action Principle ◽  
Hamiltonian Form ◽  
Set Up

The paper deals with several interpenetrating electric streams moving in accordance with the equations of Maxwell and Lorentz. An action principle is set up and then a passage is made to the Hamiltonian form of the equations of motion. The Hamiltonian has considerable analogy to that for point-charge electrons, but there is some discrepancy.

EDGE DIFFRACTION IN AN ARBITRARY ANISOTROPIC MEDIUM. I

1967 ◽  
Vol 45 (11) ◽  
pp. 3479-3502 ◽  
Author(s):  
Shalom Rosenbaum
Keyword(s):  
Anisotropic Medium ◽  
Short Wavelength ◽  
Dielectric Tensor ◽  
Asymptotic Results ◽  
Asymptotic Field ◽  
Lateral Field ◽  
Reflected Waves ◽  
Edge Diffraction ◽  
Diffracted Waves ◽  
Formal Solutions

Diffraction by a perfectly conducting half-plane embedded in a transversely unbounded region filled with a uniform, lossless but arbitrarily anisotropic medium characterized by a Hermitian dielectric tensor ε is studied. Formal solutions in terms of a plane-wave modal superposition (with the modal amplitudes determined via the Wiener–Hopf technique) are obtained. Asymptotic (short-wavelength) contributions (saddle-point contributions as well as contributions due to intercepted singular points) are considered. The asymptotic results are then cast into invariant, ray optical forms, amenable to a distinct physical interpretation.Mode coupling at the boundary gives rise to diffracted (lateral) waves as well as to geometric-optical (incident and reflected) waves. In addition to the "conventional" radially diffracted waves, one observes "secondary" lateral waves generated by the edge. In the short-wavelength limit the edge behaves as a virtual line source whose magnitude is proportional to the total (direct and lateral) field incident upon it. The asymptotic field solutions are valid, subject to the exclusion of some suitably defined transition regions, which are distinctly determined by the geometric-optical expressions. The various (asymptotic) wave constituents are shown to correspond to the anticipated results of geometrical optics.

scholarly journals The Research on DC Loop of Regional Power Grid Caused by the Operation of the Subway

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 613
Author(s):  
Lin Du ◽  
Sha Chang ◽  
Shiying Wang
Keyword(s):  
Potential Distribution ◽  
Power Grid ◽  
Loop Model ◽  
Regional Power ◽  
Stray Current ◽  
Factors Affecting ◽  
Distribution Calculation ◽  
Dc Potential ◽  
Set Up ◽  
Ground Potential

The operation of the subway would change the distribution of the ground potential along the rail, forming a DC loop through the grounding points in a nearby regional power grid and threatening the operational safety of the power system. In this paper, a new DC potential distribution calculation method along the subway is firstly proposed. Secondly, a grid grounding DC loop model is built on the foundation of the stray current principle. Thirdly, factors affecting the current in the grid are also presented and discussed based on the grounding loop model. Finally, a subway operation simulation platform is set up in a laboratory to simulate the operation of subway in situation, and the rationality of the model presented in this paper has been effectively verified.

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