Advances in Physics Theories and Applications
http://www.iiste.org/Journals/index.php/APTA
The International Institute for Science, Technology and Education (IISTE)en-USAdvances in Physics Theories and Applications2224-719XJournal Cover Page
http://www.iiste.org/Journals/index.php/APTA/article/view/30928
Journal Cover PageJournal Editor56Thermodynamics Property of Magnetic Materials in a Ferromagnetic System using the Ising Model
http://www.iiste.org/Journals/index.php/APTA/article/view/30929
<p>There is hardly any branch of physics one can approach successfully without resorting to quantum statistical mechanics. It has been proven that the quantum mechanical description of a system gives accurate results. To use quantum statistical mechanics, the system are treated at their microscopic level. Most systems consist of many particles and in order o deal with such large numbers, one has to resort to statistical method related to the partition function of statistical mechanics. In this study, we haves used the partition function which is a statistical parameter to explore the thermodynamic properties such as Helmoltz free energy, Entropy, internal energy and heat capacity of a magnetic materials in a ferromagnetic system using the first and second dimensional Ising model. The results show that in one-dimensional model, phase transition does not occur at finite temperature but susceptibility of a system can be measured from the fluctuations in the magnetization in the second dimensional Ising model.</p>Akaninyene D. AntiaCyril C. Umoren56Non-Newtonian Momentum Transfer Past an Isothermal Stretching Sheet with Applied Suction
http://www.iiste.org/Journals/index.php/APTA/article/view/30930
<p>The paper discusses the flow of an incompressible non-Newtonian fluid with heat and mass transfer due to stretching of a plane elastic surface in a saturated porous medium in the approximation of boundary layer theory. An exact analytical solution of non-linear MHD momentum equation governing the self-similar flow is given. The skin friction co-efficient decreases with increase in the visco-elastic parameter k<sub>1</sub> and increase in the values of both magnetic parameter and permeability parameter. The analysis of heat and mass transfer in this flow reveals that when the wall and ambient temperature held constant, temperature at a point increase with increase in k<sub>1</sub>, k<sub>2</sub> and M<sub>n</sub> .</p>P.H.VEENA B. SURESHV. K. PRAVIN56Parameters that Affect the Backscattered Signal Power due to Stimulated Brillouin Scattering in Optical Fibres
http://www.iiste.org/Journals/index.php/APTA/article/view/30931
<p>The main objective of this paper is to analyze by simulation the parameters affecting backscattered signal power in optical fibres. Parameters affecting the backscattered power were investigated and the possibility of using these parameters to model a distributed fibre optic sensor was done. In this research work investigations were carried out using VPI software for simulations. The investigation show that when the pump and stokes (probe) wave counter propagate in the fibre there is transfer of energy between the pump and stokes wave resulting in the pump and stokes waves being depleted and amplified respectively as they travel along the fibre. Thus the Brillouin gain peaks at Brillouin frequency. Further investigations show that the backscattered power was low for input power below 5 d Bm but increased rapidly above it and saturated above input power of 10 dBm for different fibre lengths. The effect of Polarization Mode Dispersion (PMD) on Stimulated Brillouin scattering (SBS) was found to decrease the signal power over time. Further results showed that power reduces with increase in temperature and the frequency shift (Brillouin shift) is directly proportional to temperature and this was used to map out the temperature change along the fibre.</p> <p><strong>Keywords: </strong>Backscattered signal power, The Polarization Mode Dispersion (PMD), Stimulated Brillouin Scattering (SBS).</p> <p> </p>Esther KiruiDavid WaswaKen Muguro56Soret and Dufour Effect on Unsteady Free Convective MHD Heat and Mass Transfer Flow with Variable Permeability, Heat Source and Thermal Diffusion
http://www.iiste.org/Journals/index.php/APTA/article/view/30932
<p>The present paper deals with the study of unsteady two dimensional free convection with heat and mass transfer flow of an incompressible, viscous and electrically conducting fluid past a continuously moving infinite vertical plate under the influence of transverse magnetic field with variable permeability, heat source and thermal diffusion. The permeability of the porous medium fluctuates in time about a constant mean. The free stream velocity of the fluid vibrates about a mean constant value and the surface absorbs the fluid with constant velocity. Introducing the usual similarity transformations, the unsteady equations of momentum, energy and concentration are made similar. To obtain local similarity solutions of the problem, the equations are solved analytically after applying perturbation technique. The velocity field, temperature field, concentration field and skin friction co-efficient are shown graphically to observe the effects of various parameters entering in the problem. Finally a thorough discussion of different results are presented.</p> <p> </p>P.H. VEENAJyoti Gudnal V. K.PRAVIN56