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JTAP-01.10.2023

Journal of Theoretical and Applied Physics (JTAP)

Editor-in-Chief: Davoud Dorranian, PhD

Online ISSN: 2251-7235

Print ISSN: 2251-7227

Publishes Bimonthly

Determination of the amplitude-frequency for strongly nonlinear oscillator by two approximate analytical techniques

AbstractIn this paper, we investigate two of the analytical approximate techniques, energy balance method and amplitude-frequency formulation, and these approximate techniques are applied to solve the strongly nonlinear differential equation of a mass attached to the center of a stretched elastic wire. We present a comparative study between the energy balance method and amplitude-frequency formulation […]

Molecular structure, vibrational spectra, UV–vis, NBO, and NMR analyses on nevirapine using ab initio DFT methods

AbstractNevirapine is an anti-human immunodeficiency virus (HIV) agent that belongs to the class of the non-nucleoside inhibitors of the HIV-1 virus reverse transcriptase. Spectral characteristics of nevirapine have been probed into by methods of Fourier transform infrared (FTIR), FT-Raman, UV-visible, and quantum chemistry. The UV spectrum was measured in methanol. In order to gain some […]

String cloud and domain walls with quark matter in kink cosmological model

AbstractWe have studied quark matter coupled with string cloud and domain walls in the context of general relativity. For this purpose, we solved Einstein’s field equations for quark matter coupled to the string cloud and domain walls in spherical symmetric kink space-time. It is found that cosmic strings and domain walls do not survive in […]

GEMs and amplitude bounds in the colored Boulatov model

AbstractIn this paper, we construct a methodology for separating divergencies due to different topological manifolds dual to Feynman graphs in a colored group field theory. After having introduced the amplitude bounds using propagator cuts, we show how Graph-Encoded Manifold (GEM) techniques can be used in order to factorize divergencies related to different parts of the […]

Nonstandard Lagrangian cosmology

AbstractWe show that many independent scenarios as the ‘accelerated expansion of the universe’, ‘eternal inflation’, ‘eternally oscillating universe’, ‘nonsingular oscillating universe’, and ‘collapse of an oscillating universe’ may occur without modifying the gravity theory or introducing scalar fields of any type. This is achieved by replacing the standard Lagrangian in the Friedmann-Robertson-Walker spacetime model by […]

Variational calculation with general density functional to solve the electronic Schrödinger equation directly for ground state: a recipe for self-consistent field solution

AbstractUsing orbital-free framework, a simple numerical optimization of the density functional for ground state electronic energy is described for any type of functional approximation, demonstrated via the example of linear combinations of homogeneous functionals of the density. The numerical recipe is given and analyzed for solution: Originating from the linear dependence of nuclear-electron attraction functional […]

The effect of film thickness on surface morphology of ITO thin films

AbstractIn this work, we developed the rescaled range method and its formalism to investigate the surface morphology dynamics of indium tin oxide (ITO) thin films. The dynamic scaling behavior of grown ITO thin films, which were prepared by electron beam deposition method on float glass substrates at room temperature, was studied through atomic force microscopy […]

Grand canonical ensemble of the extended two-site Hubbard model via a nonextensive distribution

AbstractWe hereby introduce a research about a grand canonical ensemble for the extended two-site Hubbard model, that is, we consider the intersite interaction term in addition to those of the simple Hubbard model. To calculate the thermodynamical parameters, we utilize the nonextensive statistical mechanics; specifically, we perform the simulations of magnetic internal energy, specific heat, […]

Investigation on the production of copper nitride (copper azide) thin films and their nanostructures

AbstractCopper thin films of 80-nm thickness were deposited on glass substrate using electron beam deposition at two different deposition angles of 0° and 40°, and they were post-annealed under flow of nitrogen at different temperatures. The structure of the films was analyzed using X-ray diffraction, atomic force microscope, and scanning electron microscope. Investigation on the […]

Design, synthesis, and characterization of TPA-thiophene-based amide or imine functionalized molecule for potential optoelectronic devices

AbstractNew sets of molecules containing tri-phenyl-amine (TPA) core and thiophene unit with amide and imine functional groups are designed, synthesized, characterized, and compared. These are solution processable small molecules with high mobility. The newly designed molecules have better solubility due to the C=N (imine) and CONH2 (amide) moiety as compared to the established molecules with […]