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Journal of Theoretical and Applied Physics (JTAP)

Editor-in-Chief: Davoud Dorranian

Online ISSN: 2251-7235

Print ISSN: 2251-7227

Publishes Bimonthly

Volume 13 (2019)

Issue 1, February 2019

Calculating the band structure of 3C-SiC using sp3d5s* + ∆ model

AbstractWe report on a semiempirical tight-binding model for 3C-SiC including the effect of sp3d5s* orbitals and spin–orbit coupling (∆). In this work, we illustrate in detail the method to develop such a model for semiconductors with zincblende structure, based on Slater–Koster integrals, and we explain the optimization method used to fit the experimental results with […]

Effect of combined laser dyes on the efficiency of cholesteric liquid crystal lasers

AbstractA high efficiency band-edge cholesteric liquid crystal (CLC) laser comprising an optimal binary-dye mixture (OBD) with 62 wt% DCM and 38 wt% PM597 as the active medium is scrutinized. The measurements indicate that both the fluorescence spectrum width and the order parameter of OBD in the host of nematic liquid crystal (BL009) enhance compared with those for each […]

On the soft emission mechanism in X-ray pulsars

AbstractWe propose a mechanism responsible for the soft emission in X-ray pulsars. We discuss the origin of the soft emission for isolated X-ray pulsars as well as for soft gamma-ray repeaters and anomalous X-ray pulsars. We also offer an explanation for the spectral features detected in the isolated X-ray pulsar 1E 1207.4-5209.

Impact of geometry and magneto-optical properties on field enhancement and optical bistability in core–shell nanoparticles

AbstractWe study the interaction of electromagnetic field with two of the most tunable nanostructure geometries for nanoplasmonics including the magneto-optical nanoshell structure and the spheroidal geometry. We investigate the effect of combining both geometry and magneto-optical properties within the same nanostructure on the field enhancement factor and optical bistability behaviors. Since the coupling between the […]

Effect of magnetic field on electromagnetic soliton evolution by different pulses

AbstractSolitons evolve in a nonlinear and dispersive medium whenever the balance is obtained between the effects of dispersion and nonlinearity. In this work, we study the impact of an external magnetic field on electromagnetic soliton profile in nonrelativistic two-fluid plasma using IMEX scheme. We found that different kinds of perturbing pulses create two solitons of […]

The role of entropic penalties of circular DNA assembly in spectroscopy and imaging

AbstractRecently, some authors have considered thermodynamics of DNA and obtained its entropy. In parallel, they have shown that phonons which are agents of temperature and entropy have direct effects on the electrons. Motivated by these researches, we obtain the relation between entropy and electronic properties of DNA like its radiated waves. We examine the model […]

Determination of elastic constants of Inconel-625 superalloy, using laser-based ultrasonic

AbstractThis paper deals with the determination of the elastic constants of Inconel-625 from the analysis of laser-generated ultrasonic bulk waves. A pulsed Nd/YAG laser (1064 nm) is used for ultrasonic generation in a thick stepped Inconel-625 sample, and a He–Ne laser is used for heterodyne detection of the laser-generated signals. Ultrasonic signals obtained at epicenter and […]

The effect of structural defects on the electron transport of MoS2 nanoribbons based on density functional theory

AbstractUsing non-equilibrium Green’s function method and density functional theory, we study the effect of line structural defects on the electron transport of zigzag molybdenum disulfide (MoS2) nanoribbons. Here, the various types of non-stoichiometric line defects greatly affect the electron conductance of MoS2 nanoribbons. Although such defects would be lead to the electron scattering, they can […]

Study of deformation microstructure of nickel samples at very short milling times: effects of addition of α-Al2O3 particles

AbstractDeformation microstructure of pure Ni powder milled for short duration was studied. The microstructure, as obtained on the basis of Rietveld analysis and microstructural modeling, shows inhomogeneity and consists of ‘heavily deformed’ with twin faults probability and ‘slightly deformed’ components with varying dislocation densities. The modified Williamson–Hall analysis was performed for both the subcomponents with […]

Investigation of physical issues of the initial conditions of free water surface due to underwater disturbances on the basis of SPH numerical simulation of the phenomenon

AbstractThe current paper discusses the physical impacts of the various initial boundary conditions of the free surface of a waterbody on the initiation and propagation characteristics of water waves due to the underwater perturbations. Differences between traditional point of view and applied numerical method in this paper for exertion the initial conditions of the generated […]