Synthesis of the anisotropic impedance cylinder on the given polarization of the scattered field independent on the angle of incidence and polarization of incidence field

The equations of propagation of electromagnetic waves in a stratified medium (i.e. a medium in which the refractive index is a function of one Cartesian coordinate only—in practice the height) are obtained first from Maxwell's equations for a material medium, and secondly from the treatment of the refracted wave as the sum of the incident wave and the wavelets scattered by the particles of the medium. The equations for the propagation in the presence of an external magnetic field are also derived by a simple extension of the second method.The significance of a reflection coefficient for a layer of stratified medium is discussed and a general formula for the reflection coefficient is found in terms of any two independent solutions of the equations of propagation in a given stratified medium.Three special cases are worked out, for waves with the electric field in the plane of incidence, viz.(1) A finite, sharply bounded, medium which is “totally reflecting” at the given angle of incidence.(2) Two media of different refractive index with a transition layer in which μ2 varies linearly from the value in one to the value in the other.(3) A layer in which μ2 is a minimum at a certain height and increases linearly to 1 above and below, at the same rate.For cases (2) and (3) curves are drawn showing the variation of reflection coefficient with thickness of the stratified layer.Case (3) may be of some importance as a first approximation to the conditions in the Heaviside layer.

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DIFFRACTION BY A CONDUCTING HALF-PLANE IN AN ANISOTROPIC PLASMA

Canadian Journal of Physics ◽

10.1139/p64-133 ◽

1964 ◽

Vol 42 (8) ◽

pp. 1455-1468 ◽

Cited By ~ 21

Author(s):

E. V. Jull

Keyword(s):

Magnetic Field ◽

Half Plane ◽

Scattered Field ◽

Plane Electromagnetic Wave ◽

Plane Waves ◽

Angular Spectrum ◽

Anisotropic Plasma ◽

Angle Of Incidence ◽

Dual Integral Equations ◽

Magnetostatic Field

The diffraction of a plane electromagnetic wave by a perfectly conducting half-plane in an anisotropic plasma is considered. The plasma is characterized by a permittivity tensor and the wave is assumed to propagate in a direction normal to the magnetostatic field and the diffracting edge, but its angle of incidence is otherwise arbitrary. Only the H-polarized wave of the incident field, which has a single magnetic field component parallel to the edge, is affected by the anisotropy and the analysis is restricted accordingly. Representing the scattered field as an angular spectrum of plane waves leads to dual integral equations from which an expression for the scattered field is obtained. The total field is then reduced to Fresnel integrals and its far-field behavior is investigated. Agreement with Seshadri and Rajagopal's result for a wave normally incident on the conductor, which was obtained by using the Wiener–Hopf technique, is found. The differences between isotropic and anisotropic solutions to this problem, which arise from the differing boundary conditions on the tangential magnetic field, are examined.

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Can cognitive structure outcomes reveal cognitive styles? A study on the relationship between cognitive styles and cognitive structure outcomes on the subject of chemical kinetics

Chemistry Education Research and Practice ◽

10.1039/c8rp00018b ◽

2018 ◽

Vol 19 (3) ◽

pp. 746-754

Author(s):

Elif Atabek-Yigit

Keyword(s):

Cognitive Style ◽

Chemical Kinetics ◽

Cognitive Styles ◽

Cognitive Structure ◽

Field Dependency ◽

Field Independent ◽

Figure Test ◽

Flow Map ◽

The Given ◽

The Relationship

Determination of the relationship between individuals’ cognitive styles and cognitive structure outcomes was the main aim of this study. Sixty-six participants were enrolled in the study and their cognitive styles were determined by using the Hidden Figure Test (for their field dependent/independent dimension of cognitive style) and the Convergent/Divergent Test (for their convergence/divergence dimension of cognitive style). An open-ended questionnaire was formed in order to determine participants’ cognitive structure outcomes. The study topic was chosen as chemical kinetics since it is one of the most difficult topics in chemistry according to many students and also there is limited study in the literature on this topic. Key concepts about chemical kinetics were selected and given to the participants and they were asked to write a text by using the given concepts. A flow map technique was used to reveal participants’ cognitive structure outcomes. According to the findings of this study, it can be said that field independent participants tended to be divergent thinkers while field dependents tended to be convergent thinkers. Also, strong positive relationships between participants’ field dependency/independency and some cognitive structure outcomes (extent and richness) were found. That is, field independents tended to have more extended and richer cognitive structure outcomes. However, the convergence/divergence dimension of cognitive style did not show any correlation with cognitive structure outcomes.

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A Generalized case of Electromagnetic Scattering from a finite number of Ferromagnetic cylinders

Advanced Electromagnetics ◽

10.7716/aem.v4i3.264 ◽

2015 ◽

Vol 4 (3) ◽

pp. 8 ◽

Cited By ~ 1

Author(s):

T. Kumar ◽

N. Kalyanasundaram ◽

B. K. Lande

Keyword(s):

Finite Number ◽

Electromagnetic Scattering ◽

Scattered Field ◽

Near Field ◽

Scattering Problem ◽

Normal Incidence ◽

Generalized Solution ◽

Numerical Results ◽

Infinite Length ◽

Angle Of Incidence

A generalized solution of the scattering problem from an array containing a finite number of axially magnetized ferromagnetic cylinders of infinite length placed in free space is presented in this paper. The analysis is carried out by matching the tangential boundary conditions at the surface of each cylinder to find the unknown expansion coefficients of the scattered field. Planar arrays consist of a finite number of ferromagnetic microwires are considered to obtain the numerical results for TMz and TEz polarizations in terms of the variation in scattered field components of the near field and scattering cross section (SCS) with respect to angle of incidence, radius of microwires, spacing among the microwires and operating frequency. For validation purpose, numerical results of the proposed analysis specialized for the case of single microwire and normal incidence for TMz polarization are compared with the results available in the literature for the specialized case and both are found to be matched completely.

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Electromagnetic scattering by a dielectric sphere partially buriedin an infinte plane

Canadian Journal of Physics ◽

10.1139/p02-053 ◽

2002 ◽

Vol 80 (9) ◽

pp. 979-986

Author(s):

A -K Hamid ◽

M Hamid

Keyword(s):

Plane Wave ◽

Electromagnetic Scattering ◽

Plane Electromagnetic Wave ◽

Ground Plane ◽

Scattering Problem ◽

Dielectric Constants ◽

Angle Of Incidence ◽

Spherical Scatterer ◽

Incident Plane ◽

The Given

An analytical solution of the scattering problem of a plane electromagnetic wave scattered by a dielectric spherical scatterer residing or partially buried in an infinite perfectly conducting ground plane is formulated in conjunction with the method of images. With imaging, the geometry is replaced by two touching or overlapping dielectric spheres in the absence of the ground plane, but with the given incident plane wave and its plane-wave image to satisfy the boundary conditions on the ground plane in the original problem. Numerical results are presented for the normalized scattering cross section at an arbitrary height from the ground plane, at any specific angle of incidence, and different relative dielectric constants. PACS Nos.: 41.10H, 41.90

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Active Reflectors: Possible Solutions Based on Reflectarrays and Fresnel Reflectors

International Journal of Antennas and Propagation ◽

10.1155/2009/653952 ◽

2009 ◽

Vol 2009 ◽

pp. 1-13 ◽

Cited By ~ 8

Author(s):

Lorena Cabria ◽

José Ángel García ◽

Julio Gutiérrez-Ríos ◽

Antonio Tazón ◽

Juan Vassal'lo

Keyword(s):

Evolutionary Algorithms ◽

Radiation Pattern ◽

Scattered Field ◽

Active Antenna ◽

Modulator Structure ◽

Integration Problems ◽

Iq Modulator ◽

The Given ◽

Optimal Configurations ◽

Made In

An overview about some of the recent Spanish developments on active reflectors is presented. In the first part, a novel beamsteering active reflectarray is deeply studied. It is based on implementing in each elementary radiator an IQ modulator structure, in which amplitude and phase control of the scattered field is achieved. Finally, a special effort is made in offering solutions to overcome the active antenna integration problems. In the second part, the active concept is firstly extended to Fresnel reflectors. Thanks to the development of a proper simulator, this special structure can be easily analysed. This simulator allows the study of performance of this kind of reflectors and, applying evolutionary algorithms, to find optimal configurations of reflector in accordance with the given specifications for the conformal radiation pattern.

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Electromagnetic scattering by a system of two parallel dielectric prolate spheroids

Canadian Journal of Physics ◽

10.1139/p90-060 ◽

1990 ◽

Vol 68 (4-5) ◽

pp. 376-384 ◽

Cited By ~ 14

Author(s):

M. F. R. Cooray ◽

I. R. Ciric ◽

B. P. Sinha

Keyword(s):

Electromagnetic Wave ◽

Incident Wave ◽

Electromagnetic Scattering ◽

Scattered Field ◽

Plane Electromagnetic Wave ◽

Angle Of Incidence ◽

Algebraic Equations ◽

Column Matrix ◽

Prolate Spheroids ◽

Expansion Coefficients

An exact solution to the problem of scattering of a plane electromagnetic wave by two dielectric prolate spheroids with parallel major axes is obtained by expanding the incident, scattered, and transmitted electric and magnetic fields in terms of an appropriate set of vector spheroidal eigenfunctions. The incident wave is considered to be a monochromatic, uniform plane electromagnetic wave of arbitrary polarization and angle of incidence. The boundary conditions are imposed by expressing the electromagnetic field scattered by one spheroid in terms of the spheroidal coordinates attached to the other, using the translational addition theorems for vector spheroidal wave functions. The column matrix of the total transmitted and scattered field-expansion coefficients is equal to the product of a square matrix, which is independent of the direction and polarization of the incident wave, and the column matrix of the known incident field-expansion coefficients. The solution of the associated set of algebraic equations gives the unknown transmitted and scattered field-expansion coefficients. Even though the problem is formulated in general, the numerical results are presented for the bistatic and backscattering cross sections of two lossless prolate spheroids with various axial ratios and center-to-center distances.

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On the influence of the thickness of air-space on total reflection of electric radiation

Proceedings of the Royal Society of London ◽

10.1098/rspl.1897.0114 ◽

1898 ◽

Vol 62 (379-387) ◽

pp. 300-310 ◽

Cited By ~ 10

Keyword(s):

Critical Angle ◽

Total Reflection ◽

Index Of Refraction ◽

Angle Of Incidence ◽

Minimum Thickness ◽

Light Waves ◽

Air Space ◽

Air Film ◽

The Given

In my preliminary experiments on the determination of the index of refraction of various substances for electric radiation, I used a single serai-cylinder of the given substance; the electric ray was refracted from the denser medium into air, and at the critical angle of incidence it underwent total reflection. The experiment was repeated with two semi-cylinders separated by a parallel air-space. With light waves an extremely thin air-film is effective in producing total reflection. But a question might arise whether waves a hundred thousand times as long would be totally reflected by films of air, and, if so, it would be interesting to find out the minimum thickness of air-space which would be effective in producing this result.

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ON LANGUAGE FEATURES IN TEXT SECONDARY VERBALIZATION: A COGNITIVE STYLE PARAMETER

Bulletin of Udmurt University. Series History and Philology ◽

10.35634/2412-9534-2021-31-5-1005-1009 ◽

2021 ◽

Vol 31 (5) ◽

pp. 1005-1009

Author(s):

I.A. Stepanova

Keyword(s):

Cognitive Style ◽

Cognitive Styles ◽

Field Dependency ◽

Syntactic Features ◽

Field Independent ◽

The Given ◽

Secondary Text

The article describes verbal manifestations of the parameter ‘intentionality’ within the linguistic persona based on the conception of cognitive styles. The description of field-dependency/field-independency style is given. The sequence of the research is described - classifying the respondents into different poles of the given cognitive style, by using the AKT-70 technique (U. Ettrich), reading of the unknown text by the respondents, completing the given task with the subsequent verbalization of the results. The semantic-syntactic features of the secondary text verbalization by the style holders, namely such characteristics as ‘directivity’ and ‘centering/decentering’, are discussed in details. Such feature as ‘directivity’ appeared equal for both poles, while ‘centering’ is much more pronounced for the group of field-independent respondents.

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