Author

# S. K. Adhikari

Bio: S. K. Adhikari is an academic researcher from University of Calcutta. The author has contributed to research in topic(s): Wave propagation & Radio wave. The author has an hindex of 1, co-authored 11 publication(s) receiving 7 citation(s).

##### Papers

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TL;DR: The analytical form of the absorption index appropriate to the D- and E-region of the ionospheric plasma is derived in this article. And the results are presented graphically along with an earlier work.

Abstract: The analytical form of the absorption index appropriate to the D- and E-region of the ionospheric plasma is derived. It has been utilised to build up Schlomilch's integral equation. The corresponding solution is obtained in terms of certain ionospheric parameters. The variation of effective collision frequency with height has been computed numerically from the derived solution. The results are presented graphically along with an earlier work.

4 citations

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TL;DR: In this article, the wave equations in an anisotropic plasma imbedded in a moving dielectric medium have been derived through Maxwell-Minkowski relations for longitudinal and transverse cases of propagation.

Abstract: Wave equations in an anisotropic plasma imbedded in a moving dielectric medium have been derived through Maxwell-Minkowski relations. These are solved for longitudinal and transverse cases of propagation. The dispersion relation within the medium has been deduced through which the nature of splitting may be understood.

1 citations

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TL;DR: A brief review of Cerenkov radiation within the upper atmospheric plasma has been presented in this article, where the results of analysis about the nature and characteristics of VLF hisses in terms of incoherent Cererkov radiation are given in a concise manner.

Abstract: A brief review of Cerenkov radiation within the upper atmospheric plasma has been presented. Different attempts in this context are systematically discussed. The results of analysis about the nature and characteristics of VLF hisses in terms of incoherent Cerenkov radiation are given in a concise manner. The occurrence of resonance cone has also been reported.

1 citations

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TL;DR: In this article, the authors derived expressions for the low-frequency part of the fractional pressure variations in the E-region of the ionosphere under the stated perturbed condition may be considered to be manifested through Lorentzforce and Joule-dissipation that influence the neutral gas of the atmosphere via collision-mechanism and thereby gravity waves are launched.

Abstract: Generation of short-range gravity waves within the ionosphere due to inhomogenous heating in the presence of space-localized inhomogeneities during high-power radio wave-propagation has been investigated. The magnitude and from of the anticipated atmospheric wave-trains are obtained. The derived experession of electric field within the ionosphere under the stated perturbed condition may be considered to be manifested through Lorentz-force and Joule-dissipation that influence the neutral gas of the atmosphere via collision-mechanism and thereby gravity waves are launched. The expressions for the low-frequency part of the fractional pressure variations have been derived which are applied to theE-region of the ionosphere. The results are presented graphically.

1 citations

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TL;DR: In this paper, the nonlinear heating of electrons in the ionospheric plasma due to high-power radio wave propagation was investigated through an integro-differential equation derived from Boltzmann velocity-moment equations.

Abstract: The non-linear heating of electrons in the ionospheric plasma due to high-power radio wave propagation has been investigated through an integro-differential equation derived from Boltzmann velocity-moment equations. Various processes appropriate to the situation under study are taken into account. The numerical solution of the derived equation is presented graphically.

##### Cited by

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TL;DR: In this paper, the convergence of a Dickson polynomial solution of the model problem is investigated by means of the residual function, and the exact solutions are compared with other well-known methods in tables.

Abstract: In this study, we solve some widely-used model problems consisting of linear, nonlinear differential and integral equations, employing Dickson polynomials with the parameter-α and the collocation points for an efficient matrix method. The convergence of a Dickson polynomial solution of the model problem is investigated by means of the residual function. We encode useful computer programs for model problems, in order to obtain the precise Dickson polynomial solutions. These solutions are plotted along with the exact solutions in figures and the numerical results are compared with other well-known methods in tables.

22 citations

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01 Jun 2017TL;DR: The generalized fractional order of the Chebyshev orthogonal functions (GFCF) collocation method is used to handle many forms of Schlomilch integral equations.

Abstract: In this paper, the linear and nonlinear Schlomilch’s integral equations and their generalized forms are studied. The Schlomilch’s integral equations are used for many ionospheric problems, atmospheric and terrestrial physics. The generalized fractional order of the Chebyshev orthogonal functions (GFCF) collocation method is used to handle many forms of Schlomilch’s integral equations. The GFCF method can be used in the applied physics, applied mathematics, and engineering applications. The reliability of the GFCF method is justified through illustrative examples.

18 citations

26 Dec 1962

TL;DR: In this article, the authors investigated the radiation from a point charge moving uniformly in a plasma, when the charge is moving in the direction of an external magnetic field, and obtained two sets of values of these parameters, the frequency and the angular spectrum of the emitted radiation.

Abstract: The radiation from a point charge moving uniformly in a plasma is investigated when the charge is moving in the direction of an external magnetic field. In general, there are two modes, for each of which all the components of the electric and magnetic field are present. The two parameters of interest in this problem are the ratio of the velocity of the charges to the free-space velocity of electromagnetic waves, and the ratio of the gyromagnetic frequency to the plasma frequency of the electrons. For two sets of values of these parameters, the frequency and the angular spectrum of the emitted radiation are obtained. In certain cases, as many as three Cherenkov rays are found to propagate in the same direction; these multiple-rays, however, correspond to different frequency components and to different modes of propagation. The motivation for this investigation is indicated briefly. (auth)

13 citations

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TL;DR: The accompanied regularization method with each of the two used methods proved its efficiency in handling many problems especially ill-posed problems, such as the Fredholm integral equation of the first kind.

Abstract: In this paper, the exact solutions of the Schlomilch’s integral equation and its linear and non-linear generalized formulas with application are solved by using two efficient iterative methods. The Schlomilch’s integral equations have many applications in atmospheric, terrestrial physics and ionospheric problems. They describe the density profile of electrons from the ionospheric for awry occurrence of the quasi-transverse approximations. The paper aims to discuss these issues.,First, the authors apply a regularization method combined with the standard homotopy analysis method to find the exact solutions for all forms of the Schlomilch’s integral equation. Second, the authors implement the regularization method with the variational iteration method for the same purpose. The effectiveness of the regularization-Homotopy method and the regularization-variational method is shown by using them for several illustrative examples, which have been solved by other authors using the so-called regularization-Adomian method.,The implementation of the two methods demonstrates the usefulness in finding exact solutions.,The authors have applied the developed methodology to the solution of the Rayleigh equation, which is an important equation in fluid dynamics and has a variety of applications in different fields of science and engineering. These include the analysis of batch distillation in chemistry, scattering of electromagnetic waves in physics, isotopic data in contaminant hydrogeology and others.,In this paper, two reliable methods have been implemented to solve several examples, where those examples represent the main types of the Schlomilch’s integral models. Each method has been accompanied with the use of the regularization method. This process constructs an efficient dealing to get the exact solutions of the linear and non-linear Schlomilch’s integral equation which is easy to implement. In addition to that, the accompanied regularization method with each of the two used methods proved its efficiency in handling many problems especially ill-posed problems, such as the Fredholm integral equation of the first kind.

4 citations

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TL;DR: In this paper, the nonlinear heating of electrons in the ionospheric plasma due to high-power radio wave propagation was investigated through an integro-differential equation derived from Boltzmann velocity-moment equations.

Abstract: The non-linear heating of electrons in the ionospheric plasma due to high-power radio wave propagation has been investigated through an integro-differential equation derived from Boltzmann velocity-moment equations. Various processes appropriate to the situation under study are taken into account. The numerical solution of the derived equation is presented graphically.