scholarly journals Fundamental Problems of the Electrodynamics of Heterogeneous Media

2012 ◽  
Vol 2012 ◽  
pp. 1-28 ◽  
Author(s):  
N. N. Grinchik ◽  
Yu. N. Grinchik
Keyword(s):  
Mathematical Model ◽  
Electric Double Layer ◽  
Layered Medium ◽  
Heterogeneous Media ◽  
Heterogeneous Medium ◽  
Surface Current ◽  
Charge Carriers ◽  
Thermal Fields ◽  
Dirichlet Theorem ◽  
Generalized Wave Equation

The consistent physic-mathematical model of propagation of an electromagnetic wave in a heterogeneous medium is constructed using the generalized wave equation and the Dirichlet theorem. Twelve conditions at the interfaces of adjacent media are obtained and justified without using a surface charge and surface current in explicit form. The conditions are fulfilled automatically in each section of counting schemes for calculations. A consistent physicomathematical model of interaction of nonstationaly electric and thermal fields in a layered medium with allowance or mass transfer is constructed. The model is based on the methods of thermodynamics and on the equations of an electromagnetic field and is formulated without explicit separation of the charge carriers and the charge of an electric double layer.

SH-wave propagation in heterogeneous media: Velocity‐stress finite‐difference method

Geophysics ◽  
1984 ◽  
Vol 49 (11) ◽  
pp. 1933-1942 ◽  
Author(s):  
Jean Virieux
Keyword(s):  
Wave Propagation ◽  
Finite Difference ◽  
Layered Medium ◽  
Heterogeneous Media ◽  
Heterogeneous Medium ◽  
Head Wave ◽  
Sh Wave ◽  
Quarter Plane ◽  
Discrete Grid ◽  
Lateral Propagation

A new finite‐difference (FD) method is presented for modeling SH-wave propagation in a generally heterogeneous medium. This method uses both velocity and stress in a discrete grid. Density and shear modulus are similarly discretized, avoiding any spatial smoothing. Therefore, boundaries will be correctly modeled under an implicit formulation. Standard problems (quarter‐plane propagation, sedimentary basin propagation) are studied to compare this method with other methods. Finally a more complex example (a salt dome inside a two‐layered medium) shows the effect of lateral propagation on seismograms recorded at the surface. A corner wave, always in‐phase with the incident wave, and a head wave will appear, which will pose severe problems of interpretation with the usual vertical migration methods.

Effect of Interfaces on the Properties of Polycrystalline Thin-Film PZT Ferroelectric Capacitors

2006 ◽  
Vol 966 ◽  
Author(s):  
Lyuba A. Delimova ◽  
Igor Grekhov ◽  
Dmitri Mashovets ◽  
Ilya Titkov ◽  
Valentin Afanasjev ◽  
...  
Keyword(s):  
Thin Film ◽  
Grain Boundaries ◽  
Heterogeneous Medium ◽  
Photovoltaic Effect ◽  
Short Circuit ◽  
Charge Carriers ◽  
Polycrystalline Thin Film ◽  
Field Interaction ◽  
Polarization Charge ◽  
Ferroelectric Capacitors

ABSTRACTA photocurrent directed opposite to ferroelectric (FE) polarization is observed in short-circuit thin-film polycrystalline Pt/PZT/Ir structures. The direction and magnitude of photocurrent are defined by the sign and magnitude of the FE polarization. A model based on a photovoltaic effect with characteristics determined by polarization of PZT grains is proposed. The model considers the field interaction of FE polarization charge with the charge carriers in intergranular PbO channel. Thin-film FE capacitor is considered as a photosensitive heterogeneous medium, where the conduction of PbO channels along PZT grain boundaries is controlled by FE polarization.

APPLICATION OF THE INTEGRAL LAGUERRE TRANSFORMS FOR FORWARD SEISMIC MODELING

2001 ◽  
Vol 09 (04) ◽  
pp. 1523-1541 ◽  
Author(s):  
G. V. KONYUKH ◽  
B. G. MIKHAILENKO ◽  
A. A. MIKHAILOV
Keyword(s):  
Layered Medium ◽  
Heterogeneous Medium ◽  
Efficient Algorithms ◽  
Second Order ◽  
Seismic Modeling ◽  
Elastic Parameters ◽  
Laguerre Transform ◽  
Medium Model ◽  
Second Order Equations

The paper presents some efficient algorithms based on the application of the integral Laguerre transform for approximation of temporal derivatives. Some specific features of employing this algorithm for the first and the second order equations with respect to time are considered. A few examples of calculation of seismic fields for the layered medium model with drastically contrast elastic parameters and for the 2-D heterogeneous medium model are presented.

Mathematical model of a heterogeneous medium consisting of a matrix and spherical inclusions

1999 ◽  
Vol 40 (4) ◽  
pp. 704-711
Author(s):  
S. P. Kiselev ◽  
V. M. Fomin
Keyword(s):  
Mathematical Model ◽  
Heterogeneous Medium ◽  
Spherical Inclusions

The mathematical model of fluid filtration to the well of drift type in stress heterogeneous medium

2013 ◽  
Author(s):  
B. T. Zhumagulov ◽  
N. T. Azhikhanov ◽  
Zh. K. Masanov ◽  
K. T. Bissembaeva
Keyword(s):  
Mathematical Model ◽  
Heterogeneous Medium ◽  
Fluid Filtration ◽  
The Mathematical Model

scholarly journals HELICONS IN PLASMA SOLID-STATE WAVEGUIDE OF CYLINDRICAL CONFIGURATION

2019 ◽  
pp. 19-23
Author(s):  
Yu.O. Averkov ◽  
Yu.V. Prokopenko ◽  
V.M. Yakovenko
Keyword(s):  
Magnetic Field ◽  
Longitudinal Magnetic Field ◽  
Surface Current ◽  
Side Surface ◽  
Longitudinal Axis ◽  
Charge Carriers ◽  
Plasma Waveguide ◽  
Bulk Surface ◽  
Axis Of Symmetry ◽  
Hybrid Waves

The theory of electromagnetic eigenwaves of a cylindrical plasma waveguide located in a constant longitudinal magnetic field has been created. A dispersion equation has been obtained under condition when the ratio of the collision frequency of the majority charge carriers to their cyclotron frequency is substantially less than one. It is shown there are bulk-surface helicons in a plasma waveguide. In the absence of charge-carrier collisions, their propagation is accompanied by a surface current directed parallel to the longitudinal axis of symmetry of the cylinder. Collisions of charged particles destroy the surface current and lead to the formation of additional H-type hybrid waves, the field localizations of which are concentrated near the side surface of the waveguide. The nonreciprocity effect of the eigenwaves, differing in the direction of propagation along the azimuthal coordinate, as well as when the direction of the external magnetic field is changed, has been discovered.

Influence of temperature on the hydrothermal clay soils' shear strength of the Nizhne-Koshelevsky and Verkhne-Pauzhetsky thermal fields.

2021 ◽  
Author(s):  
Ruslan Kuznetsov ◽  
Mikhail Chernov ◽  
Victoria Krupskaya ◽  
Ruslan Khamidov
Keyword(s):  
Internal Friction ◽  
Double Layer ◽  
Electric Double Layer ◽  
Geothermal Field ◽  
The Other ◽  
Clay Soils ◽  
Clayey Soils ◽  
Clay Particles ◽  
Angle Of Internal Friction ◽  
Thermal Fields

<p>Nizhne-Koshelevskoe and Verkhne-Pauzhetskoe thermal fields are located in the south of Kamchatka, the first - within the Koshelevsky volcanic massif, the second - on the territory of the Pauzhetsky geothermal field. The first horizon from the surface in these fields is formed by clayey soils, that have been formed as a result of hydrothermal alteration of volcanic rocks. And in the natural conditions clayey soils are at temperatures reaching 100 °C.</p><p>Samples of undisturbed clay soils were taken within the thermal fields. The samples are characterized by a density of 1.29 - 1.42 g/cm<sup>3</sup>, rather high values of the weight moisture (90-110%), and temperatures of 50 - 70 °C.</p><p>The samples are dominated by clay minerals: kaolinite and mixed-layer - kaolinite-smectite, their content is about 75%. The other 25% are microcline, cristobalite, anatase, gypsum, pyrite, marcasite, quartz and alunite.</p><p>For samples of undisturbed clay soils, direct shear tests were carried out at a temperature of 20 °C and at a temperatures of the samples close to their natural temperatures (50–70 °C). Thus, the values of cohesion and the angle of internal friction of the samples were determined.</p><p>The obtained results can be interfered as follows: as a result of an increase in the temperature of clayey soils, the thickness of electric double layer on the surface of clay particles decreases. On the one hand, it leads to a decrease of cohesion value between the clay particles and the beginning of shear deformations at lower vertical loads. On the other hand, a smaller thickness of electric double layer brings particles closer to each other, which is the reason for an increasing angle of internal friction and shear resistance at higher vertical loads.</p>

Mathematical model of testing of pipeline integrity by thermal fields

2014 ◽  
Author(s):  
Nataliia Vaganova
Keyword(s):  
Mathematical Model ◽  
Thermal Fields
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