Vol. 7 & Issue 2 ; Section C : Physical Sciences

Date : Feb. to April 2017

 

Marichev–Saigo–Maeda Fractional Differential Operator Involving Mittag–Leffler Type Function with Four Parameters

Dinesh Kumar, Rajeev Kumar Gupta and Devendra Singh Rawat

  • Abstract

    The object of this paper is to establish certain generalized fractional differentiation involving Mittag–Leffler type function with four parameters ξ, λEμν [z] which has been recently introduced by Garg et al.18. The considered generalized fractional derivative operators contain the Appell’s function F3 as kernel is introduced by Marichev25,26. Some interesting special cases are also given to fractional differentiation operators in terms of Wright hyper-geometric functions.

Chemical bath deposition of CdSe and its photoelectrochemical performance

Narayana Swamy T N, Pushpalatha H L, Ganesha R

  • Abstract

    Nanocrystalline cadmium selenide thin films were prepared at 11.6 pH, 70 °C on fluorine doped tin oxide glass substrates (FTO; F:SnO2) by chemical bath deposition using cadmium sulfate as cadmium source and sodium selenosulfate as selenium source. Liquid ammonia was used as complexing agent. The as deposited CdSe thin films were vacuum annealed at 250 °C for 5h.The XRD study of CdSe thin film revealed that the film exhibited polycrystalline nature having both cubic and hexagonal phase. The thickness of the film was estimated and found to be 242.3nm. From optical study it was found that the film has direct band gap of 2.2eV. The scanning electron microscopic (SEM) analysis showed that the obtained CdSe thin film exhibited cabbage-like morphology with fine grain back ground. The film is well adherent to the substrate, free from cracks, pin holes and uniformly well covered on substrate. The surface wettability test showed that the film has hydrophilic surface nature and this property facilitates the formation of better interfacial region at the photoelectrode of the fabricated photoelectrochemical (PEC) cell. The PEC performance of the CdSe thin film was found to be 0.17% and the film has n-type conductivity.

Mechatronic Design of An Electromechanical Pitching System for More Realistic Load Simulations of Wind Turbines by Means of the Bond Graph Methodology

Zakaria Khaouch, Mustapha Zekraoui, Nourreeddine Kouider, Mustapha Mabrouki

  • Abstract

    The pitch system is the most safety subsystem of the wind turbine, at the same time; the pitch system is critical for optimizing the power production and serves as the actuator in the rotor speed control loop and as an emergency brake under failure conditions. To better understand the dynamic behaviors and enhance numerical simulation efficiency of electromechanical pitching system (EPS) in a wind turbine generator system (WTGS), a detailed mechatronic model is presented. By introducing the basic principle of all parts of EPS includes the subsystem models of actuator and its control strategy, driver train and blade. By means of the bond graph approach (BGA). For large wind turbines, control algorithms to enhance maximum and quality power are developed using the pitch system as an actuator, but these control loops are often designed without taking the real behavior of the pitch system into account. With the new model presented her, the real behavior of the pitch system is takes into consideration, as a result the final load simulation is more realistic and offering benefits and reliable system performance. First, a detailed bond graph model of an EPS is developed considering its dynamic characteristics. Thereafter, the control law is derived by using the concept of bicausality of the bond graph, and compared with a conventional PID controller. Finally, the dynamic characteristics of an EPS using the proposed model are analyzed and verified based on 20-sim program.

Structural and optical properties of RF- sputtered ZnS and Zn(S, O) thin films

M. Cheikh, M. Chaik, H. El aakib, M.Elyaagoubi, M. Aggour, A. Outzourhit

  • Abstract

    Zinc sulfide [ZnS] and oxygenated zinc sulfide Zn(S, O) thin films were deposited on glass substrates, by reactive cathodic radio-frequency (RF) sputtering. The substrate power and percentage of oxygen were varied in the range of 100W to 250W and from 5% to 20% respectively. The structural, morphological and optical properties of these thin films were investigated. The optical properties (mainly the refractive index,absorption coefficient and optical band gap) were examined by optical transmission measurements in the ultraviolet-visible-near Infrared wavelength range. XRD analysis indicated that all the sputtered ZnS films were single phase with a preferential orientation along the (111) plane of zinc blend (ZB) phase. The crystallite size varied from 19.5 nm to 48.5 nm with RF power reaching a maximum at 200 W. The Zn(S, O) films, on the other hand, were amorphous. UV-Visible, measurements showed that the ZnS film had more than 80% transmittance in the visible wavelength region while that of Zn(S, O) is 85%. Moreover it was observed that the band gap energy of the ZnS films increases slightly from 3.4 to 3.52 eV as the RF power was increased. The optical band gap of Zn(S, O), on the other hand, was 4.2 eV for low oxygen partial pressures and decreased to 3.89 eV as the oxygen partial pressure is increased in the sputtering atmosphere at a fixed RF-power. Scanning electron microscopy observations revealed smooth surfaces for both type of films. The X-ray reflectometry measurements on the ZnS films showed that the density of the films (3.9 g/cm3) is close to that of bulk ZnS. 

A theoretical evaluation of many-body effects to equation of state and chemical potential of optically trapped quasi-2D Bose gas

Puran Saw and L. K. Mishra

  • Abstract

    Using the theoretical formalism of Ying Hu and Z. Liang [arXiv: 1103.3079v1 [cond.Mat.quan.gas] 16 march 2011], we have studied the optically trapped quasi-2D Bose gas and evaluated chemical potential of the gas. Taking the ground state energy and differentiating with respect to total number of particles, chemical potential was evaluated. After proper asymptotic analysis, it was found that in the asymptotic 3D regime, the value is consistent with 3D Lee-Huang-Yang result (Phys. Rev 106, 1135 (1957)). On the other hand in the opposite pure 2D limit it stands in good agreement with C. Mora and Y. Castin result [PRL 102, 180404 (2009)]. The calculation also gives first correction to the 3D mean-field (MF) equation of state arising from the 2D effect. In an another calculation, using theoretical formalism of Sylvan Nascimbeue et al.(arXiv:1006.4053v1 [cond.mat.quant. gas) 21 June 2010), we have evaluated equation of state of a Bose gas in an optical lattice in the Mott-insulator regime. Our evaluated results are in good agreement with other theoretical workers. We have also evaluated the equation of state of the 2D homogeneous Bose gas. Our theoretically evaluated results were compared with EOS (Schivk formulae), perturbative EOS and EOS (A. Boudjimnaa). Our theoretically evaluated results are in good agreement with these workers.

Certain Generalized Fractional Integral Formulas Associated with Generalized M-Series

Rajeev Kumar Gupta, Bhupender Singh Shaktawat and Madan Lal

  • Abstract

    The object of this paper is to establish certain generalized fractional integration involving generalized M-series introduced by Faraj et al. [1]. The results are expressed in terms of generalized Wright hypergeometric [2] function pψq  (z) . On account of the general nature of the generalized M-series, several new and known results can easily be found as special cases of our main results.

Mathematical model for entropy generation analysis of MHD micropolar fluid flow: A numerical study

A. K. Dash and B.P.Acharya

  • Abstract

    Aim of the present paper is to study the micropolar fluid behaviour on steady MHD heat and mass transfer flow past over a stretching surface with Newtonian heating(NH), Constant wall temperature (CWT) and constant heat flux (CHF) boundary conditions. The heat generation/absorption and destructive /generative chemical reaction have been considered in this paper. The governing nonlinear partial differential equations are transformed by similarity technique into dimensionless ordinary coupled non-linear differential equations. The obtained dimensionless equations are solved numerically by using Runge–Kutta method along with Nachtsheim–Swigert iteration technique. Though this study is very complicated to solve, it is necessary to investigate in detail the distributions of velocity, microrotation, temperature and concentration across the boundary layer in addition to the surface shear stress i.e. skin friction, rate of heat transfer (Nusselt number) and rate of mass transfer (Sherwood number).

An Evaluation of temperature dependent frequency and damping rate of condensate breathing mode and frequency of collective excitations of optically trapped quasi-2D Bose gas

Puran Saw and L. K. Mishra

  • Abstract

    Using the theoretical formalism of Ying Hu and Z. Liang [arXiv:1103.3079v1 [cond. Mat. quan. gas] 16 march 2011], we have theoretically evaluated the frequency shift of optically trapped quasi-2D Bose gas. The frequency shifts were calculated in three different ways: (i) taking the transverse breathing mode in an elongated trap using TF approximation. (ii) Taking the lowest compression mode in disk like geometry using TF approximation. (iii) Taking the amplitude of oscillating frequency with non-linearity effect. We observed that from (i) and (ii) ways the results of frequency shifts are identical. In the third evaluation, the frequency shift increases very sharply with A (the amplitude of oscillating frequency of the cloud. Our theoretically evaluated results are in good agreement with other theoretical workers.Using the time dependent Gross-Pitaevskii (GP) equation, we have determined the frequency of the rubidium atoms as a function of atoms N for even parity m=0 and m=2.Our theoretically evaluated values are in good agreement with the experimental data. In other calculation, we have determined the mode frequency as a function of asymmetry parameter λ . Our calculation shows that there are two types of mode frequency ω+ and ω- . ω- increases very sharply and attains a constant values whereas ω+ increases very slowly but enhances very sharply. Our evaluation of temperature dependent frequency and damping rate of condensate breathing mode are also in good agreement with the experimental data.

A Discrete Model for Hiv-1 in Vivo Dynamics in the Presences of Chemotherapy with Delay in Infectivity of Target Cells

Wesley Kirui

  • Abstract

    In this paper, we consider a discrete mathematical model of HIV-1 in vivo dynamics in the presences of chemotherapy and delay in infectivity of target cells. A novel feature in this work is that both delay in infectivity of CD4+T-cells and chemotherapy are incorporated into the discrete HIV-1 in vivo dynamics. We establish the necessary and sufficient condition for global stability of Disease free equilibrium. We also perform numerical simulations which supports the obtained theoretical results.

Measurement of the nuclear elements suspension involved in bones ability

Sameera A. Ebrahien and Noor Adil Mohammed

  • Abstract

    In this study, the nuclear stopping capacity of the elements involved in the synthesis of the nodules and the input in the following reactions was measured (28Si (p,n)28P, 29Si (p,n)29P, 30Si (p,n) 30P, 31P (p,n)31S , 40Ca (a,n) 43Ti ,44Ca (p,n)45Sc, 26Mg (p,n)26Al,64Zn (p,n)64 Ga and 61Cu (a,n)64 Zn reaction by using Zekler equations (SRIM) program . Using the Matlab program, the stopping capacity of energies ranging from (11 MeV to 116 MeV) was calculated with energy steps of (5 MeV). The results showed that the maximum value of the stopping power is in the reaction 40Ca (a,n) 43Ti in the energy (11 MeV) is (0.2913 MeV/(mg/cm2)) and that the lowest stopping power was in the reaction 44Ca (p,n)45Sc and in the energy (16 MeV) is ( 0.0043 MeV/(mg/cm2) ) .Drawn and tabulated the results .

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