MODULATION OF ELECTROMAGNETIC WAVES BY ACOUSTIC WAVES IN A PLASMA

1964 ◽  
Vol 42 (8) ◽  
pp. 1635-1642 ◽  
Author(s):  
Mahendra Singh Sodha ◽  
Carl James Palumbo
Keyword(s):  
Electromagnetic Wave ◽  
Acoustic Wave ◽  
Acoustic Waves ◽  
Free Space ◽  
Electromagnetic Waves ◽  
Reflected Waves

This communication presents an analysis of the modulation of an electromagnetic wave, propagating in a plasma, in which an acoustic wave is present. The modulation of the transmitted and reflected waves from a plasma-free space interface has also been analyzed. A discussion of the results obtained has also been given.

scholarly journals To the Question of the Independence of the Surface Electromagnetic Wave Frequency

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
V. K. Balkhanov ◽  
Yu B. Bashkuev
Keyword(s):  
Electromagnetic Wave ◽  
Layer Thickness ◽  
Dielectric Layer ◽  
Free Space ◽  
Electromagnetic Waves ◽  
Wave Frequency ◽  
Waveguide Channel ◽  
Surface Electromagnetic Wave ◽  
Minimum Frequency ◽  
Waveguide Theory

Earth's the surface is often strongly inductive, consisting of a dielectric layer thickness endpoint, lying on an unlimited conductor basis. Electromagnetic wave, spreading along the surface, it appears captured dielectric layer, spreading it as in the waveguide channel. Waveguide theory it is known that the spread in the waveguide can only electromagnetic waves with a discrete set of frequencies. And experience shows that the captured waveguide channel electromagnetic waves can be any frequency. The article found that this behavior is due to the fact that electromagnetic waves in free space border - dielectric layer damped height in several wavelengths. Thus the thickness of the dielectric layer becomes more effectively, and this leads to a reduction of the minimum frequency of the waveguide. A discrete set of frequencies is blurred so that cover each other. Thus, a discrete set of frequencies becomes solid, and captured waveguide channel electromagnetic waves are independent of frequency.

scholarly journals Interaction of electromagnetic waves in an ice layer

2019 ◽  
Vol 127 ◽  
pp. 02011
Author(s):  
Vladimir Korochentsev ◽  
Wei Xue ◽  
Gennadiy Shabanov ◽  
Artem Em ◽  
Yuliya Shpak
Keyword(s):  
Mathematical Model ◽  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Free Space ◽  
Electromagnetic Waves ◽  
Wave Amplitude ◽  
Spherical Wave ◽  
Ice Thickness ◽  
Suggested Model ◽  
Ice Surface

A mathematical model for spherical wave propagation near an ice layer has been developed. The proposed mathematical model is based on the directed Green’s functions with boundary conditions with irregular angles. Based on the suggested model, we analyzed a field of a point directed source radiating electromagnetic waves in two cases: the source is in the air and is radiating waves along the marine ice surface; the source is in the ice layer and radiating waves. Results of the modeling for different frequencies and different ice thickness are described. It was shown that wave amplitude increases by about two times inside the ice if compared to free space. Electromagnetic wave propagating along marine ice surface increases by 50% compared to the wave propagating in free space.

scholarly journals Performance analysis of vortex acoustic wave based on uniform circular array

2021 ◽  
Vol 2078 (1) ◽  
pp. 012069
Author(s):  
Jie Xu ◽  
Hui Li ◽  
You-Ling zhou ◽  
Qian Li ◽  
Liu-Xun Xue ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Acoustic Waves ◽  
Electromagnetic Waves ◽  
Spectrum Efficiency ◽  
Underwater Acoustic Communication ◽  
Circular Array ◽  
Acoustic Beam ◽  
Array Generation ◽  
The Relationship ◽  
Transmission Speed

Abstract As a carrier for information and energy, acoustic waves have been applied in underwater communication widely, however, the narrow band and low transmission speed are the main problems. Whether in the field of optics or electromagnetic waves, the orbital angular momentum (OAM) represents the natural properties of the spiral phase structure. By introducing the OAM into the acoustics field, the transmission capacity and spectrum efficiency of the underwater acoustic communication system can be expanded. Based on the analysis and detection of the vortex acoustic wave generated by the circular array of transducers, we studied the array generation method of the spiral acoustic beam, and gave the characteristics of the vortex acoustic beam when propagating under the water. In the direction of the main axis, the uniform circular array was used to generate different topological acoustic vortex. To determine the relationship between the OAM topology mode and the transducer array, the spiral acoustic waves in different topology modes were generated, and the number of array elements, array radius, transmission frequency, etc. were investigated to give the effects on OAM acoustic vortex.

scholarly journals Investigation of the channel for information transfer by electric, electromagnetic and acoustic waves in layered environment with ice cover

2020 ◽  
Vol 196 ◽  
pp. 02014
Author(s):  
Vladimir Korochentsev ◽  
Vey Syue ◽  
Viktor Petrosyants ◽  
Artem Em ◽  
Ivan Garasev ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Acoustic Waves ◽  
Electromagnetic Waves ◽  
Information Transfer ◽  
Electromagnetic Wave Propagation ◽  
Low Frequency ◽  
Acoustic Signals ◽  
Half Wave ◽  
To Receive

A theoretical model of electromagnetic wave propagation in an ice layer was developed. A half-wave vibrator frozen in an ice layer is used as a receiving-radiating system of electromagnetic waves. Schemes of developed acoustic low-frequency radiators based on electric sparks are described. The possibility of application of the developed systems to receive acoustic signals from earthquake ice source is under discussion.

Detection of delamination in composites by using electromagnetic penetrating radar

2014 ◽  
Vol 5 (2) ◽  
pp. 151-156
Author(s):  
Z. Mechbal ◽  
A. Khamlichi
Keyword(s):  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Wave Reflection ◽  
Image Features ◽  
Partial Reflection ◽  
Straight Path ◽  
Reflected Signal ◽  
Short Time ◽  
Intervening Factors

Composites made from E-glass/epoxy or aramid/epoxy are frequently used in aircraft and aerospace industries. These materials are prone to suffer from the presence of delamination, which can reduce severely the performance of aircrafts and even threaten their safety. Since electric conductivity of these composites is rather small, they can propagate electromagnetic waves. Detection of delamination damage can then be monitored by using an electromagnetic penetrating radar scanner, which consists of emitting waves having the form of short time pulses that are centered on a given work frequency. While propagating, these waves undergo partial reflection when running into an obstacle or a material discontinuity. Habitually, the radar is moved at constant speed along a straight path and the reflected signal is processed as a radargram that gives the reflected energy as function of the two-way time and the antenna position.In this work, modeling of electromagnetic wave propagation in composites made from E-glass/epoxy was performed analytically. The electromagnetic wave reflection from a delamination defect was analyzed as function of key intervening factors which include the defect extent and depth, as well as the work frequency. Various simulations were performed and the obtained results have enabled to correlate the reflection pattern image features to the actual delamination defect characteristics which can provide quantification of delamination.

New Approach to the Theory of Circular Dichroism

1998 ◽  
Vol 63 (8) ◽  
pp. 1187-1201 ◽  
Author(s):  
Jaroslav Zamastil ◽  
Lubomír Skála ◽  
Petr Pančoška ◽  
Oldřich Bílek
Keyword(s):  
Electromagnetic Wave ◽  
Circular Dichroism ◽  
Electromagnetic Waves ◽  
Maxwell Equations ◽  
Optically Active ◽  
Semiclassical Approach ◽  
New Approach ◽  
Isotropic Media ◽  
New Formula ◽  
Circular Dichroïsm

Using the semiclassical approach for the description of the propagation of the electromagnetic waves in optically active isotropic media we derive a new formula for the circular dichroism parameter. The theory is based on the idea of the time damped electromagnetic wave interacting with the molecules of the sample. In this theory, the Lambert-Beer law need not be taken as an empirical law, however, it follows naturally from the requirement that the electromagnetic wave obeys the Maxwell equations.

scholarly journals Preparation and electromagnetic properties characterization of reduced graphene oxide/strontium hexaferrite nanocomposites

2020 ◽  
Vol 9 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Shumin Du ◽  
Huaiyin Chen ◽  
Ruoyu Hong
Keyword(s):  
Electromagnetic Wave ◽  
Environmental Pollution ◽  
Electromagnetic Interference ◽  
Electromagnetic Waves ◽  
Rapid Development ◽  
Living Environment ◽  
World Health ◽  
Electromagnetic Properties ◽  
Strontium Hexaferrite ◽  
Wave Radiation

AbstractWith the rapid development of electronics and information technology, electronics and electrical equipment have been widely used in our daily lives. The living environment is full of electromagnetic waves of various frequencies and energy. Electromagnetic wave radiation has evolved into a new type of environmental pollution that has been listed by the WHO (World Health Organization) as the fourth largest source of environmental pollution after water, atmosphere, and noise. Studies have shown that when electromagnetic wave radiation is too much, it can cause neurological disorders. And electromagnetic interference will cause the abnormal operation of medical equipment, precision instruments and other equipment, and therefore cause incalculable consequences. Therefore, electromagnetic protection has become a hot issue of concern to the social and scientific circles.

scholarly journals Formation of a Complex Topologies of SAW-Based Inertial Sensors by Laser Thin Film Local Evaporation

Micromachines ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Alexander Kukaev ◽  
Dmitry Lukyanov ◽  
Denis Mikhailenko ◽  
Daniil Safronov ◽  
Sergey Shevchenko ◽  
...  
Keyword(s):  
Thin Film ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Acoustic Waves ◽  
Inertial Sensors ◽  
Surface Acoustic Waves ◽  
Sensing Element ◽  
Small Series ◽  
Evaporation Technique ◽  
Photolithography Process

Originally, sensors based on surface acoustic waves are fabricated using photolithography, which becomes extremely expensive when a small series or even single elements are needed for the research. A laser thin film local evaporation technique is proposed to substitute the photolithography process in the production of surface acoustic wave based inertial sensors prototypes. To estimate its potential a prototype of a surface acoustic wave gyroscope sensing element was fabricated and tested. Its was shown that the frequency mismatch is no more than 1%, but dispersion of the wave on small inertial masses leads to a spurious parasitic signal on receiving electrodes. Possible ways of its neglecting is discussed.

Numerical simulation for coupled nonlinear Schrödinger–Korteweg–de Vries and Maccari systems of equations

2021 ◽  
pp. 2150339
Author(s):  
Lanre Akinyemi ◽  
Pundikala Veeresha ◽  
Samuel Oluwatosin Ajibola
Keyword(s):  
Numerical Simulation ◽  
Plasma Physics ◽  
Acoustic Waves ◽  
Electromagnetic Waves ◽  
Nonlinear Partial Differential Equations ◽  
Transform Method ◽  
Langmuir Waves ◽  
Suggested Approach ◽  
Nonlinear Schrödinger ◽  
De Vries

The primary goal of this paper is to seek solutions to the coupled nonlinear partial differential equations (CNPDEs) by the use of q-homotopy analysis transform method (q-HATM). The CNPDEs considered are the coupled nonlinear Schrödinger–Korteweg–de Vries (CNLS-KdV) and the coupled nonlinear Maccari (CNLM) systems. As a basis for explaining the interactive wave propagation of electromagnetic waves in plasma physics, Langmuir waves and dust-acoustic waves, the CNLS-KdV model has emerged as a model for defining various types of wave phenomena in mathematical physics, and so forth. The CNLM model is a nonlinear system that explains the dynamics of isolated waves, restricted in a small part of space, in several fields like nonlinear optics, hydrodynamic and plasma physics. We construct the solutions (bright soliton) of these models through q-HATM and present the numerical simulation in form of plots and tables. The solutions obtained by the suggested approach are provided in a refined converging series. The outcomes confirm that the proposed solutions procedure is highly methodological, accurate and easy to study CNPDEs.

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