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LRS Bianchi Type-II Cosmological Model with a Decaying Lambda Term

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Chinese physics Letters 2012年第1期29卷 35-37页

作者： R.k.Tiwari D.Tiwari pratibha Shukla Department of Mathematics Govt.Model Science College RewaM.P.486001India

We consider a locally rotationally symmetric(LRS)Bianchi type-Ⅱspacetime with a perfect fluid and a variable cosmological constant∧.To solve the Einstein field equations we consider the cosmological term∧to be proportional to R^(-m) with R being the scale factor and m a constant[***.D 58(1998)043506].In this model we obtain∧~H^(2),∧~(R)/R and Larnbda~t^(-2),in agreement with the main dynamical laws for the decay of∧.The physical significance of the cosmological model is also discussed.

关键词： Bianchi Cosmo perfect

Design concepts of an aircraft wing： composite and morphing airfoil with auxetic structures

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Frontiers of Structural and Civil Engineering 2016年第4期10卷 394-408页

作者： p R BUDARApU Sudhir Sastry Y B R NATARAJAN Department of Aerospace Engineering Indian Institute of Science Bangalore 560 012 India Department of Aeronautical Engineering College of Engineering Defence University Ethiopia Department of Aeronautical Engineering Institute of Aeronautical Engineering Hyderabad India

This paper is categorized into two parts. （1） A frame work to design the aircraft wing structure and （2） analysis ofa morphing airfoil with auxetic structure. The developed design frame work in the first part is used to arrive at the sizes of the various components of an aircraft wing structure. The strength based design is adopted, where the design loads are extracted from the aerodynamic loads. The aerodynamic loads acting on a wing structure are converted to equivalent distributed loads, which are further converted point loads to arrive at the shear forces, bending and twisting moments along the wing span. Based on the estimated shear forces, bending and twisting moments, the strength based design is employed to estimate the sizes of various sections of a composite wing structure. A three dimensional numerical model of the composite wing structure has been developed and analyzed for the extreme load conditions. Glass fiber reinforced plastic material is used in the numerical analysis. The estimated natural frequencies are observed to be in the acceptable limits. Furthermore, the discussed design principles in the first part are extended to the design of a morphing airfoil with auxetic structure. The advantages of the morphing airfoil with auxetic structure are （i） larger displacement with limited straining of the components and （ii） unique deformation characteristics, which produce a theoretical in-plane poisson＇s ratio of -1. Aluminum Alloy AL6061-T651 is considered in the design of all the structural elements. The compliance characteristics of the airfoil are investigated through a numerical model. The numerical results are observed to be in close agreement with the experimental results in the literature.

关键词： wing design aerodynamic loads morphing airfoil auxetic structures negative poisson's ratio

Size-dependent effect on biaxial and shear nonlinear buckling analysis of nonlocal isotropic and orthotropic micro-plate based on surface stress and modified couple stress theories using differential quadrature method

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Applied Mathematics and Mechanics(English Edition) 2016年第4期37卷 529-554页

作者： M.MOHAMMADIMEHR M.A.MOHAMMADIMEHR p.dashTI Department of Solid Mechanics Faculty of Mechanical EngineeringUniversity of Kashan

The size-dependent effect on the biaxial and shear nonlinear buckling analysis of an isotropic and orthotropic micro-plate based on the surface stress, the modified couple stress theory （MCST）, and the nonlocal elasticity theories using the differential quadrature method （DQM） is presented. Main advantages of the MCST over the classical theory （CT） are the inclusion of the asymmetric couple stress tensor and the consideration of only one material length scale parameter. Based on the nonlinear von karman assumption, the governing equations of equilibrium for the micro-classical plate consid- ering midplane displacements are derived based on the minimum principle of potential energy. Using the DQM, the biaxial and shear critical buckling loads of the micro-plate for various boundary conditions are obtained. Accuracy of the obtained results is validated by comparing the solutions with those reported in the literature. A parametric study is conducted to show the effects of the aspect ratio, the side-to-thickness ratio, Eringen＇s nonlocal parameter, the material length scale parameter, Young＇s modulus of the surface layer, the surface residual stress, the polymer matrix coefficients, and various boundary conditions on the dimensionless uniaxial, biaxial, and shear critical buckling loads. The results indicate that the critical buckling loads are strongly sensitive to Eringen＇s nonlocal parameter, the material length scale parameter, and the surface residual stress effects, while the effect of Young＇s modulus of the surface layer on the critical buckling load is negligible. Also, considering the size dependent effect causes the increase in the stiffness of the orthotropic micro-plate. The results show that the critical biaxial buckling load increases with an increase in G12/E2 and vice versa for E1/E2. It is shown that the nonlinear biaxial buckling ratio decreases as the aspect ratio increases and vice versa for the buckling amplitude. Because of the most lightweight mic

关键词： biaxial and shear nonlinear buckling analysis nonlocal isotropic and orthotropic micro-plate modified couple stress theory (MCST) surface stress effect differential quadrature method (DQM)

A Note on the Invariance properties and Conservation Laws of the kadomstev–petviashvili Equation with power Law Nonlinearity

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Chinese physics Letters 2011年第9期28卷 10-11页

作者： A H Bokhari F D Zaman k Fakhar A H kara Department of Mathematical Sciences King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia Department of Mathematics Faculty of ScienceUniversiti Teknologi Malaysia81310 UTM SkudaiJohorMalaysia Ibnu Sina Institute for Fundamental Science Studies Universiti Teknologi Malaysia81310 UTM SkudaiJohorMalaysia School of Mathematics University of the WitwatersrandJohannesburgWits 2050South Africa

First,we studied the invariance properties of the kadomstev–petviashvili equation with power law ***,we determined the complete class of conservation laws and stated the corresponding conserved densities which are useful in finding the conserved quantities of the *** point symmetry generators were also used to reduce the equation to an exact solution and to verify the invariance properties of the conserved flows.

关键词： equation conserved equation

Asymptotic iteration approach to supersymmetric bistable potentials

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Chinese physics B 2012年第1期21卷 68-73页

作者： H. Ciftci O. zer p. Roy Gazi niversitesi Fen-Edebiyat Fakültesi Fizik Blümü 06500 Teknikokullar-Ankara Turkey Department of Engineering physics Faculty of Engineering University of Gaziantep 27310 Gaziantep Turkey physics and Applied Mathematics Unit Indian Statistical Institute Calcutta 700035 India

We examine quasi exactly solvable bistable potentials and their supersymmetric partners within the framework of the asymptotic iteration method （AIM）. It is shown that the AIM produces excellent approximate spectra and that sometimes it is found to be more useful to use the partner potential for computation. We also discuss the direct application of the AIM to the Fokker-planck equation.

关键词： bistable potentials asymptotic iteration

A Criterion for the Change from Fast to Slow Regime of Cementite Dissolution in Fe-C-Mn Steels

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Journal of Materials Science & Technology 2012年第8期28卷 728-736页

作者： M.Gouné p.Maugis J.Drillet Arcelor Mittal Research Maizières Voie RomaineBP 30320Maizières-lès-Metz 57283France ICMCB-CNRS 87 avenue du Docteur SchweitzerPessac 33609France IM2Np-UMR CNRS 6242&Aix-Marseille University Avenue Escadrille Normandie Niemen-Case 142-13397 Marseille Cedex 20France

The present study clarifies the role of Mn in cementite on the driving force of cementite dissolution and the growth of austenite. From an experimental study, the effects of manganese composition and temperature on the cementite dissolution were shown. From a theoretical analysis based on thermodynamic and kinetics considerations, a criterion for the change from fast to slow regime of cementite dissolution was proposed. This criterion is in good agreement with the experimental results. It can be easily calculated and can define the composition and temperature ranges where the cernentite dissolution is slow or fast.

关键词： phase transformation Thermodynamics kinetics Cementite dissolution Steel

Linear matrix inequality approach for synchronization control of fuzzy cellular neural networks with mixed time delays

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Chinese physics B 2012年第4期21卷 586-596页

作者： p.Balasubramaniam M.kalpana R.Rakkiyappan Department of Mathematics Gandhigram Rural Institute-Deemed UniversityGandhigram-624302TamilnaduIndia Department of Mathematics Bharathiar UniversityCoimbatore-641046TamilnaduIndia

Fuzzy cellular neural networks （FCNNs） are special kinds of cellular neural networks （CNNs）. Each cell in an FCNN contains fuzzy operating abilities. The entire network is governed by cellular computing laws. The design of FCNNs is based on fuzzy local rules. In this paper, a linear matrix inequality （LMI） approach for synchronization control of FCNNs with mixed delays is investigated. Mixed delays include discrete time-varying delays and unbounded distributed delays. A dynamic control scheme is proposed to achieve the synchronization between a drive network and a response network. By constructing the Lyapunov-krasovskii functional which contains a triple-integral term and the free-weighting matrices method an improved delay-dependent stability criterion is derived in terms of LMIs. The controller can be easily obtained by solving the derived LMIs. A numerical example and its simulations are presented to illustrate the effectiveness of the proposed method.

关键词： asymptotic stability chaos fuzzy cellular neural networks linear matrix inequalities synchronization

Use of sub-micron sized resin particles for removal of endocrine disrupting compounds and pharmaceuticals from water and wastewater

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Journal of Environmental Sciences 2017年第1期29卷 256-264页

作者： Audrey Murray Banu rmeci Edward p.C.Lai Department of Civil and Environmental Engineering Carleton University Department of Chemistry Carleton University

Endocrine disrupting compounds（EDCs） and pharmaceuticals pose a challenge for water and wastewater treatment because they exist at very low concentrations in the presence of substances at much higher concentrations competing for adsorption ***-micron sized resin particles（approximately 300 nm in diameter）（SMR） were tested to evaluate their potential as a treatment for EDCs including：17-β estradiol（E2）,17-α ethinylestradiol（EE2）,estrone（E1）,bisphenol A（BpA）,and diethylstilbestrol（DES） as well as 12 *** were able to remove 98%of spiked E2,80%of EE2,87%of BpA,and up to 97%of DES from *** a 0.5 ppm mixture of E2,EE2,E1,BpA and DES,the minimum removal was24%（E2） and the maximum was 49%（DES）.They were also able to remove the pharmaceuticals from deionized water and ***,SMR are a promising advanced treatment for removal of both EDCs and pharmaceuticals.

关键词： Water treatment Wastewater treatment pharmaceuticals Endocrine disrupting compounds Micropollutants Adsorption

Elastic properties of potassium Halides under pressure

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Journal of Materials Science & Technology 2008年第2期24卷 241-244页

作者： k.Haddadi L.Louail D.Maouche Department of physics Faculty of SciencesUniversity of SetifAlgeria

The moderate-pressure elastic properties of potassium halides kX （X=F, Cl, Br） was studied theoretically using the density functional theory （DFT） with normconserving pseudopotentials method. The phase transformation from the B1 phase （NaCl-type structure） to the denser B2 phase （CsCl-type structure） occurred at 7.7, 3.46 and 2.96 Gpa for kF, kCI and kBr, respectively. The elastic stiffness coefficients and bulk modulus of these materials were calculated as function of hydrostatic pressure and compared with both the experimental and theoretical values.

关键词： phase transitions Elastic coefficients Solid alkali halides