JOURNAL OF THEORETICAL AND APPLIED PHYSICS (IRANIAN PHYSICAL JOURNAL)
Year:2011 | Volume:5 | Issue:2|Papers Count:8

We obtain analytical expressions for the two-body T-martix and phase shift at high energy (~350 MeV) scattering using nonlocal rank-two separable potential of Mongan type. The potential parameters are adjusted by fitting the available experimental nucleon-nucleon high energy scattering phase shift data for two single channels 1D2 and 1P1 with the corresponding derived analytical expressions. The results indicate that the analytical expressions obtained for the phase shifts are succsseful in repoducing the nucleon-nucleon scattering data.

In this Paper, we apply two approximate analytical methods of Perturbation Method (PM) and Homotopy Perturbation Method (HPM) to solve the equation of beam deformation with two fixed end and under uniform distributed load. The presented results in this paper reveal that these two methods are very effective and can be easily extended to other nonlinear systems and can therefore be found widely applicable in engineering and other sciences.

In this experimental research the effects of oxygen-argon plasma on the structure and morphology of Poly Methyl Methacrylate (PMMA) polymer doped with orange L-3R dye is investigated. Samples with 0.2 mm thickness were produced by drying the solution of PMMA granule in dichloromethane. Experiment was carried out in a low pressure chamber with plane electrodes. Plasma was generated with a RF source of 13.56 MHz frequency at 70 W output power. Samples were exposed to different fraction of oxygen-argon plasma for 5 minutes. Based on AFM results surface roughness of samples is significantly altered and the water contact angle is decreased noticeably. With increasing oxygen in the working gas up to 80% the structure of polymer surface and its surface energy are increased leads to removal of grooves on polymer samples. Change of absorption coefficient and the energy gaps of treated polymers are calculated from their UV-NIR-VIS transmission spectrum.

The purpose of this paper is to present a formulation of supersymmetry quantum mechanics on noncommutative space. In particular we construct Supersymmetric Quantum Mechanics (SQM) in terms of N=2 real supercharges on noncommutative space in arbitrary dimensions. The exact eigenspectra of the two dimensional noncommutative superoscillators is obtained.

We numerically analyzed the photonic band structure of 2-D metallic-dielectric photonic crystal structures which consist of square arrays with circular metal rods. We calculated dispersion curves of square lattice with metal rods which are embedded into background materials with different dielectric constants for TM and TE modes and changed the ratio of the rods’ radius to the lattice constant (r/a).We also investigated the effect of changing metal rods on the photonic band structures in two steps. In the first step, we changed background materials with fixed r/a constant and then we fixed both ther/aratio and background dielectricconstants. Because we designed our structure in a way that the photonic band gaps appear in a range of telecommunication wavelength the results showed that these structures will be applicable in different photonic devices such as optical filters.

Correlated density matrix theory is generalized to investigate equilibrium properties of normal Fermi Liquids such as3He and nuclear matter at nonzero temperatures. The results also generalize the Fermi-hypernetted-chain technique that is familiar from studies of the ground state of correlated fermions. By employing the concept of renormalized bosons and fermions the formal results are cast in a form that permits the direct evaluation of the statistical properties of the correlated liquid such as the entropy and the specific heat at constant volume among other quantities.

ZnO films have been synthesized on a zinc foil by chemical bath deposition route from an electrolyte of ZnCl2+H2O2 at ambient conditions. The structures, morphologies and chemical compositions of the films were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy-dispersive X-ray spectrometer (EDS). The XRD pattern shows well peaks, which can be indexed to the wurtzite hexagonal phase of ZnO. The SEM observations reveal that with an increase in deposition time, the rod structures converted to cauliflower structures. The EDS result indicates the presence of Zn and O atoms only. Photoluminescence (PL) studies evaluated different visible emissions originated from different defect mechanism. According to the obtained results, the possible growth mechanism for the variation in the morphology is discussed. This method may have a potential use in fabricating other metal oxide at low cost for technological applications.

Silver doped TiO2 nanoparticles were prepared by combination of sol-gel and arc discharge methods in liquid. The Ag/TiO2 nanoparticles were characterized by X-Ray diffraction (XRD), transmission electron microscopy (TEM) and ultra violet-visible absorption spectroscopy (UV-Vis). The visible light photocatalytic activities were successfully demonstrated for the degradation of Rhodamine B (Rh. B) as a standard organic compound under the irradiation of 90 W halogen light for 2 h. The results revealed that the Ag/TiO2 nanoparticles extended the light absorption spectrum toward the visible region and significantly enhanced the Rh. B photodegradation under visible light irradiation. 0.05 gr Ag/TiO2 nanoparticles exhibited highest photocatalytic efficiency. It has been confirmed that the Ag/TiO2 nanoparticles could be excited by visible light (E<3.2 eV). The significant enhancement in the Ag/TiO2 nanoparticles photocatalytic activity under visible light irradiation can be ascribed to the effect of doped noble metal Ag by acting as electron traps in TiO2 band gap.