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Gonbad-e Qābūs, Iran

Mehdipoor M.,Gonbad Kavous University | Esfandyari-Kalejahi A.,University of Tabriz
Astrophysics and Space Science | Year: 2012

The nonlinear propagation of ion acoustic waves in ideal plasmas consisting of degenerate electrons and positrons, and isothermal ions is investigated. The Korteweg de Vries (K-dV) equation that contains the lowest order nonlinearity and dispersion is derived from the lowest order of perturbation and a linear inhomogeneous (K-dV type) equation that accounts for the higher order nonlinearity and the dispersion relation is obtained. The stationary wave solution for these equations has been found using the renormalization method. Also, the effects of electrons and positrons densities and ion temperature on the amplitude and width of solitary waves are investigated, numerically. It is seen that higher order corrections significantly change the properties of the K-dV solitons. Also, it is found that both compressive and rarefactive solitary waves can be propagated in such plasma system. © 2012 Springer Science+Business Media B.V.


Rostami-Charati F.,Gonbad Kavous University | Hossaini Z.,Islamic Azad University at Qaemshahr
Synlett | Year: 2012

Stable derivatives of phosphonates were prepared using multicomponent reactions of dialkyl acetylenedicarboxylate with 1-(6-hydroxy-2-isopropenyl-1-benzofuran-yl)-1-ethanone or 4-hydroxycoumarin in the presence of trimethyl or triphenyl phosphite in water in good yields. © Georg Thieme Verlag.


Mehdipoor M.,Gonbad Kavous University
Astrophysics and Space Science | Year: 2012

Korteweg-de-Vries-Burger (K-dVB) equation is derived for ion acoustic shock waves in electron-positron-ion plasmas. Electrons and positrons are considered superthermal and are effectively modeled by a kappa distribution in which ions are as cold fluid. The analytical traveling wave solutions of the K-dVB equation investigated, through the (G′/G)-expansion method. These traveling wave solutions are expressed by hyperbolic function, trigonometric functions are rational functions. When the parameters are taken special values, the shock waves are derived from the traveling waves. It is observed that the amplitude ion acoustic shock waves increase as spectral index κ and kinematic viscosity η i,0 increases in which with increasing positron density β and electron temperature σ the shock amplitude decreases. Also, numerically the effect different parameters on the nonlinearity A and dispersive B terms and wave velocity V investigated. © 2011 Springer Science+Business Media B.V.


Teimouri M.,Gonbad Kavous University | Nadarajah S.,University of Manchester
Computational Statistics and Data Analysis | Year: 2013

The novel Balakrishnan skew-normal distribution was introduced in 2008. The only known scheme for simulating from this distribution is based on acceptance/rejection sampling. Here, we introduce an alternative scheme that is more efficient. We also derive various stochastic representations for the Balakrishnan skew-normal distribution. © 2012 Elsevier B.V. All rights reserved.


Neirameh A.,Gonbad Kavous University
Optik | Year: 2015

In this work new dispersive solitary wave solitons that are governed by the generalized sinh-Gordon equation. We successfully construct the new exact double periodic traveling wave solutions of the generalized Sinh-Gordon equation by introducing the binary simplest equation method. The idea introduced in this paper can be applied to other nonlinear evolution equations. Our results show that all rational and simply periodic solutions of the generalized Sinh-Gordon equation is solitary wave solutions and simpler than other methods. © 2015 Elsevier GmbH. All rights reserved.

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