IOSR-JAP   Volume-8 ~ Issue-2 ~ March-April 2016

ABSTRACT: The complete lattice dynamics (phonon dispersion curves, Debye temperatures variation, combined density of states (CDS) curves, two-phonon Raman and anharmonic elastic properties) of InP with zinc-blende structure has been investigated by van der Waal's three body force shell model (VTSM). This model incorporates the effect of van der Waal's interactions and three-body interactions into the rigid shell model of zinc blende structure, where the short range interactions are operative upto the second neighbours......

Keywords: Phonons , van der Waal's interactions , Debye temperatures variation , Combined density of states curve , Raman spectra , Phonon dispersion curves , Lattice dynamics , InP. PACS No: 63.20.-e, 65.40.Ba, 78.30.-j

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ABSTRACT: The cross sections, σ (o  jf), for the rotational transitions in N2 due to collisions with He have been computed using the quantum mechanical modified infinite order sudden approximation (IOSAM) method, at six different values of collision energy ranging from 0.1eV to 0.5eV and have been analyzed by using the power-gap law. The parameters of the power-gap law are found to depend on the collision energy through simple equations. It is observed that the equations so obtained for the fitting parameters can lead to the prediction of the cross sections at any value of collision energy, within the range explored, in good agreement with the cross sections computed by the IOSAM method.

Keywords: Atom-diatomic molecule collisions, cross-sections, N2-He system, power-gap law, rotational energy transfer.

[1]. M.H. Kabir, I.O. Antonov and M.C. Heaven, Experimental and Theoretical Investigations of Rotational Energy Transfer in HBr + He Collisions, J. Phys. Chem. A, 114, 2010, 11109–11116.
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ABSTRACT: The main aim of this paper is to develop Multivariate and Angstrom-type models from where solar radiation can be evaluated over Sahel and coastal stations in Nigeria. Global radiation is an important parameter necessary for most ecological models and an input for different solar system. Solar radiation is the radiant energy emitted by the sun from nuclear fusion that creates electromagnetic energy; solar radiation is the most evenly distribution energy resource on earth and the most abundant......
Keywords: Solar Radiation, Multivariate, Angstrom-type and Climate System.

[1]. Adeyemi, B. and Ojo, O. S. (2004). Empirical modelling of solar radiation for selected cities using multivariate regression technique. African Journal of Environmental Science and Technology, 8(10): 582–595.
[2]. Al-Salaymeh, A. (2006). Estimation of global solar radiation, energy and power. Science Alert,3(6):119–127.
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ABSTRACT: O. Box 20, Sudan Abstract: The quantity of collision rate (CR) is one of the most important parameters that need to be taken into account when dealing with gas dynamics of unsteady regime due to its role in determining the final conditions of the gas-phase formed clusters. In the present work, the so-called direct simulation Monte-Carlo (DSMC) method has been used as a computational tool to investigate the transportation modes of laser-generated Plume (LGP) of Si target into He inert gas......
Keywords:Pulsed Laser Deposition (PLD); Direct Simulation Monte-Carlo (DSMC); Nucleation and Growth; Nanoparticles (NPs); Collision Rate (CR).

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