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Dynamics of high-frequency modulated waves in a nonlinear dissipative continuous bi-inductance network

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Chinese Physics B 2021年第6期30卷 193-205页

作者： s m Ngounou F B Pelap Unitéde Recherche de mécanique et de modélisation des systèmes Physiques(UR-2 msP) Facultédes SciencesUniversitéde DschangBP 69 DschangCameroun Unitéde Recherche de matière Condensée d'Electronique et de Traitement du signal(UR-mACETs) Facultédes SciencesUniversitéde DschangBP 67 DschangCameroun

This paper presents intensive investigation of dynamics of high frequency nonlinear modulated excitations in a damped bimodal lattice. The effects of the dissipation are considered through a linear dissipation coefficient whose evolution in terms of the carrier wave frequency is checked. There appears that the dissipation coefficient increases with the carrier wave frequency. In the linear limit and for high frequency waves, study of the asymptotic behavior of plane waves reveals the existence of two additional regions in the dispersion curve where the modulational phenomenon is observed compared to the lossless line. Based on the multiple scales method exploited in the continuum approximation using an appropriate decoupling ansatz for the voltage of the two different cells, it appears that the motion of modulated waves is described by a dissipative complex Ginzburg–Landau equation instead of a Korteweg–de Vries equation. We also show that this amplitude wave equation admits envelope and hole solitons in the high frequency mode. From basic sources, we design a programmable electronic generator of complex signals with desired characteristics, which delivers signals exploited as input waves for all our numerical simulations. These simulations are performed in the LTspice software that uses realistic components and give the results that corroborate perfectly our analytical predictions.

关键词： dissipative bi-inductance network high-frequency mode continuous approximation dissipative complex Ginzburg–Landau equation programmable electronic generator LT-Pspice observations

Comprehensive investigation of stress intensity factors in rotating disks containing three-dimensional semi-elliptical cracks

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Applied mathematics and mechanics(English Edition) 2017年第11期38卷 1565-1578页

作者： m.FAKOOR s.m.N.GHOREIsHI Faculty of New sciences and Technologies University of Tehran Tehran 14395-1561 Iran

Initiation and propagation of cracks in rotating disks may cause catastrophic failures. Therefore, determination of fracture parameters under different working con- ditions is an essential issue. In this paper, a comprehensive study of stress intensity factors （sIFs） in rotating disks containing three-dimensional （3D） semi-elliptical cracks subjected to different working conditions is carried out. The effects of mechanical prop- erties, rotational velocity, and orientation of cracks on sIFs in rotating disks under cen- trifugal loading are investigated. Also, the effects of using composite patches to reduce sIFs in rotating disks are studied. The effects of patching design variables such as mechanical properties, thickness, and ply angle are investigated separately. The modeling and analytical procedure are verified in comparison with previously reported results in the literature.

关键词： stress intensity factor (sIF) semi-elliptical crack rotating disk finite ele-ment analysis (FEA)

Hidden periodicity in stripe 82 with saraswati supercluster—a fractal analysis

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Communications in Theoretical Physics 2021年第1期73卷 71-77页

作者： Vimal Raj m s swapna s sankararaman Department of Optoelectronics University of KeralaTrivandrumKerala695581-India

The manuscript attempts to explore the periodicity in the distribution of galaxies in the recently reported saraswati supercluster and the stripe 82 region containing it as an *** report of 120 mpc periodicity in the Abell galaxy clusters by power spectrum analysis is the motivation behind the *** power spectral analysis across the central part of the stripe 82 region shows a periodic variation of 3.09°or 71 mpc in fractal dimension whereas an average angular periodicity of 3.45°or 94 mpc is observed across the stripe 82 *** refers to the periodicity of complexity or cluster density of galaxy *** texture of the distribution pattern understood through lacunarity analysis indicates a near symmetric *** dimensions like box-counting dimension,information dimension and correlation dimension are also found through multifractal *** the information dimension tells about the distribution density of galactic points,the correlation dimension details the distribution of galaxies in the neighbourhood.

关键词： galaxy distribution fractal analysis multifractals lacunarity saraswati supercluster stripe 82

Compatibility of Fibreglass Woven Roving and Commercially Available Phenolic Resins

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Journal of materials science & Technology 1997年第5期13卷 379-382页

作者： Hayat, m.A. suliman, s.m.A. Dept. of mechanical Engineering Bahrain University Box 32038 Isa Town Bahrain

Three commercially available phenolic resins are assessed for compatibility with a fibreglass wovenroving reinforcement. Compatibility assessment is based on laminate physical properties f flexuralstrength and modulus in three and four point bending, interlaminar shear strength, and tensilestrength and modulus. The physical properties are also used for assessment of hand laminatedglass/phenolic systems

关键词： Glass fibers

Entanglement in a two-spin system with long-range interactions

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Chinese Physics B 2016年第8期25卷 369-372页

作者： soltani m R mahdavifar s mahmoudi m Department of Physics College of Science Yadegar-e-Imam Khomeini (RAH) Shahre-Rey Branch Islamic Azad University Department of Physics University of Guilan

The quantum entanglement between two spins in the Ising model with an added Dzyaloshinsky–moriya（Dm） interaction and in the presence of the transverse magnetic field is studied. The exchange interaction is considered as a function of the distance between spins. The negativity as a function of magnetic field, exchange and Dm interaction is *** effect of the distance between spins is studied based on the negativity. In addition, the effect of the thermal fluctuation on the negativity is also investigated.

关键词： entanglement Ising model Dm interaction negativity long range interaction

Use of silica nanopowder to accelerate CO_2 sorption by Ca(OH)_2

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Particuology 2013年第4期11卷 448-453页

作者： m.A.s.Quintanilla J.m.Valverde Faculty of Physics University of SevilleAvenida Reina Mercedes s/n

Promising technologies have recently emerged to capture CO2 from postcombustion flue gas and to enhance the production of hydrogen from natural gas by steam-methane reforming, on the basis of sorp- tion of CO2 by Ca-based powders. The rate of CO2 sorption on Ca-based powders is limited by both carbonation kinetics and transport of CO2 to unreacted sorption sites. Ca-based powders may exhibit cohesive aggregation, thus hindering gas-solids contact efficiency. In our work, we tested the sorption rate of powder samples prepared by dry mixing of a cohesive Ca（OH）2 powder with a silica nanopowder used as additive. The silica nanopowder serves to improve the dispersibility of Ca（OH）2. Consequently, when a CO2 enriched gas and the modified sorbent are brought into contact, the rate of CO2 sorption is enhanced in the initial fast phase of interest for practical applications.

关键词： FluidizationFine powdersCO2 sorptionNanoparticles

simultaneous effects of chemical reaction and Ohmic heating with heat and mass transfer over a stretching surface: A numerical study

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Chinese Journal of Chemical Engineering 2017年第9期25卷 1137-1142页

作者： s.R.mishra m.m.Bhatti Department of mathematics Siksha ‘O’ Anusandhan University shanghai Institute of Applied mathematics and mechanics Shanghai University

In this article, we have considered the simultaneous influence of ohmic heating and chemical reaction on heat and mass transfer over a stretching sheet. The effects of applied magnetic field are also taken into consideration while the induced magnetic field is not considered due to very small magnetics Reynolds number. The governing flow problem comprises of momentum, continuity, thermal energy and concentration equation which are transformed into highly nonlinear coupled ordinary differential equations by means of similarity transforms, which are then, solved numerically with the help of successive Linearization method(sLm) and Chebyshev spectral collocation method. Numerical values of skin friction coefficient, local Nusselt number, and sherwood number are also taken into account with the help of tables. The physical influence of the involved parameters of flow velocity, temperature and concentration distribution is discussed and demonstrated graphically. The numerical comparison is also presented with the existing published results and found that the present results are in excellent agreement which also confirms the validity of the present methodology.

关键词： Ohmic heating Heat and mass transfer Chemical reaction successive linearization method

Energy states of the Hulthen plus Coulomb-like potential with position-dependent mass function in external magnetic fields

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Chinese Physics B 2018年第2期27卷 234-238页

作者： m Eshghi R sever s m Ikhdair Young Researchers and Elite Club Central Tehran Branch Islamic Azad University Department of Physics Middle East Technical University Department of Physics Faculty of Science An-Najah National University Department of Electrical Engineering Near East University

We need to solve a suitable exponential form of the position-dependent mass （PDm） schr6dinger equation with a charged particle placed in the Hulthen plus Coulomb-like potential field and under the actions of the external magnetic and Aharonov-Bohm （AB） flux fields. The bound state energies and their corresponding wave functions are calculated for the spatially-dependent mass distribution function of interest in physics. A few plots of some numerical results with respect to the energy are shown.

关键词： schr6dinger equation Hulthen plus Coulomb-like potential position-dependent mass distributionfunctions perpendicular magnetic and Aharonov-Bohm flux fields

Determination of arsenic in air particulates and diesel exhaust particulates by spectrophotometry

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Journal of Environmental sciences 2005年第1期17卷 156-158页

作者： s.m.Talebi m.Abedi DepartmentofChemistry IsfahanUniversityIsfahan81745Iran

A method was developed for the determination of trace arsenic by spectrophotometry. The proposed method is rapid, simple, and inexpensive. This method can be used for sensitive determination of trace arsenic in environmental samples and especially in air particulates. The results obtained by this method as a proposed method were compared with those obtained by hydride generation atomic absorption spectrometry as a popular reported method for the determination of arsenic and an excellent agreement was found between them. The method was also used for determination of arsenic associated with airborne particulate matter and diesel exhaust particulates. The results showed that considerable amount of arsenic are associated with diesel engine particulates. The variation in concentration of arsenic was also investigated. The atmospheric concentration of arsenic was different in different sampling stations was dependent to the traffic density.

关键词： arsenic air particulates diesel exhaust particulates spectrophotometry