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حرية الوصول المقاله
1 - Displacement Fields Influence Analysis Caused by Dislocation Networks at a Three Layer System Interfaces on the Surface Topology
A Boussaha R Makhloufi S MadaniThis work consists in a numerically evaluation of elastic fields distribution, caused by intrinsic dislocation networks placed at a nanometric trilayers interfaces, in order to estimate their influence on the surface topology during heterostructure operation. The organi أکثرThis work consists in a numerically evaluation of elastic fields distribution, caused by intrinsic dislocation networks placed at a nanometric trilayers interfaces, in order to estimate their influence on the surface topology during heterostructure operation. The organization of nanostructures is ensured by the knowledge of different elastic fields caused by buried dislocation networks and calculated in the case of anisotropic elasticity. The influence of elastic fields generated by induced square and parallel dislocation networks at CdTe / GaAs / (001) GaAs trilayer interfaces was investigated. By deposition, the nanostructures organization with respect to the topology was controled. تفاصيل المقالة -
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2 - Dispersion of Torsional Surface Wave in a Pre-Stressed Heterogeneous Layer Sandwiched Between Anisotropic Porous Half-Spaces Under Gravity
R.M Prasad S KunduThe study of surface waves in a layered media has their viable application in geophysical prospecting. This paper presents an analytical study on the dispersion of torsional surface wave in a pre-stressed heterogeneous layer sandwiched between a pre-stressed anisotropic أکثرThe study of surface waves in a layered media has their viable application in geophysical prospecting. This paper presents an analytical study on the dispersion of torsional surface wave in a pre-stressed heterogeneous layer sandwiched between a pre-stressed anisotropic porous semi-infinite medium and gravitating anisotropic porous half-space. The non-homogeneity within the intermediate layer and upper semi-infinite medium is assumed to rise up, because of quadratic variation and exponential variation in directional rigidity, pre-stress, and density respectively. The displacement dispersion equation for the torsional wave velocity has been expressed in the term of Whitaker function and their derivatives. Dispersion relation and the closed-form solutions have been obtained analytically for the displacement in the layer and the half-spaces. It is determined that the existing geometry allows torsional surface waves to propagate and the observe exhibits that the layer width, layer inhomogeneity, frequency of heterogeneity in the heterogeneous medium has a great impact on the propagation of the torsional surface wave. The influence of inhomogeneities on torsional wave velocity is also mentioned graphically by means plotting the dimensionless phase velocity against non-dimensional wave number for distinct values of inhomogeneity parameters. تفاصيل المقالة -
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3 - Impact of Initial Stress on Reflection and Transmission of SV-Wave between Two Orthotropic Thermoelastic Half-Spaces
B Prasad S Kundu P Chandra PalReflection and transmission of plane waves between two initially stressed thermoelastic half-spaces with orthotropic type of anisotropy is studied. Incidence of a SV-type wave from the lower half-space is considered and the amplitude ratios of the reflected and transmit أکثرReflection and transmission of plane waves between two initially stressed thermoelastic half-spaces with orthotropic type of anisotropy is studied. Incidence of a SV-type wave from the lower half-space is considered and the amplitude ratios of the reflected and transmitted SV-wave, P-wave and thermal wave are obtained by using appropriate boundary conditions. Numerical computation for a particular model is performed and graphs are plotted to study the effect of angle of incidence of the wave and the initial stress parameters of the half-spaces. From the graphical results, it is found that the modulus of reflection and transmission coefficients of the thermal wave is very less in comparison to reflection and transmission coefficients of P- and SV-waves. It is also observed that for vertical incidence of SV-wave we have only reflected and refracted SV-waves and there is no reflected or refracted P and thermal waves, whereas for horizontal incidence of SV-wave there exists only reflected SV-wave and no other reflected or transmitted wave exists. Moreover, it is found that all the reflection and transmission coefficients are strongly affected by the initial stress parameters of the both half-spaces. تفاصيل المقالة -
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4 - Influence of Rigidity, Irregularity and Initial Stress on Shear Waves Propagation in Multilayered Media
R.K Poonia N Basatiya V KaliramanThe propagation of shear waves in an anisotropic fluid saturated porous layer over a prestressed semi-infinite homogeneous elastic half-space lying under an elastic homogeneous layer with irregularity present at the interface with rigid boundary has been studied. The re أکثرThe propagation of shear waves in an anisotropic fluid saturated porous layer over a prestressed semi-infinite homogeneous elastic half-space lying under an elastic homogeneous layer with irregularity present at the interface with rigid boundary has been studied. The rectangular irregularity has been taken in the half-space. The dispersion equation for shear waves is derived by using the perturbation technique followed by Fourier transformations. The dimensionless phase velocity is plotted against dimensionless wave number for the different size of ratios of depth of rectangular irregularity with the height of the layer and anisotropy parameters with the help of MATLAB graphical routines in presence and absence of initial stress. From the graphical results, it has been seen that the phase velocity is significantly influenced by the wave number, the depth of the irregularity, rigid boundary and initial stress. The acquired outcomes can be valuable for the investigation of geophysical prospecting and understanding the cause and evaluating of damage due to earthquakes. تفاصيل المقالة -
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5 - Anisotropic and Isotropic Elasticity Applied for the Study of Elastic Fields Generated by Interfacial Dislocations in a Heterostructure of InAs/(001)GaAs Semiconductors
R Makhloufi A Boussaha R Benbouta L BarouraThis work is a study of the elastic fields’ effect (stresses and displacements) caused by dislocations networks at a heterostructure interface of a InAs / GaAs semiconductors thin system in the cases of isotropic and anisotropic elasticity. The numerical study of أکثرThis work is a study of the elastic fields’ effect (stresses and displacements) caused by dislocations networks at a heterostructure interface of a InAs / GaAs semiconductors thin system in the cases of isotropic and anisotropic elasticity. The numerical study of this type of heterostructure aims to predict the behavior of the interface with respect to these elastic fields satisfying the boundary conditions. The method used is based on a development in Fourier series. The deformation near the dislocation is greater than the other locations far from the dislocation. تفاصيل المقالة -
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6 - Effect of Initial Stress on Propagation of Love Waves in an Anisotropic Porous Layer
S Gupta A Chattopadhyay D.K MajhiIn the present paper, effect of initial stresses on the propagation of Love waves has been investigated in a fluid saturated, anisotropic, porous layer lying in welded contact over a prestressed, non-homogeneous elastic half space. The dispersion equation of phase veloc أکثرIn the present paper, effect of initial stresses on the propagation of Love waves has been investigated in a fluid saturated, anisotropic, porous layer lying in welded contact over a prestressed, non-homogeneous elastic half space. The dispersion equation of phase velocity has been derived. It has been found that the phase velocity of Love waves is considerably influenced by porosity and anisotropy of the porous layer, inhomogeneity of the half-space and prestressing present in the media, the layer and the half-space. The effect of the medium characteristics on the propagation of Love waves has been discussed and results of numerical calculations have been presented graphically. تفاصيل المقالة -
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7 - Two New Non-AFR Criteria for Depicting Strength Differential Effect (SDE) in Anisotropic Sheet Metals
F Moayyedian M KadkhodayanThe issue of pressure sensitivity of anisotropic sheet metals is investigated with introducing two new non-AFR criteria which are called here linear and non-Linear pressure sensitive criteria. The yield and plastic potential functions of these criteria are calibrated wi أکثرThe issue of pressure sensitivity of anisotropic sheet metals is investigated with introducing two new non-AFR criteria which are called here linear and non-Linear pressure sensitive criteria. The yield and plastic potential functions of these criteria are calibrated with directional tensile/compressive yield stresses and directional tensile Lankford coefficients, respectively. To determine unknown coefficients of yield and plastic potential functions of these criteria two error functions are presented which are minimized by Downhill Simplex Method. Three anisotropic materials are considered as case studies such as Al 2008-T4 (BCC), Al 2090-T3 (FCC) and AZ31 (HCP). It is shown that the non-Linear pressure sensitive criterion is more accurate than the linear one and other existed criteria compared to experimental results in calculating the directional mechanical properties of anisotropic sheet metals. تفاصيل المقالة -
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8 - On the Dynamic Characteristic of Thermoelastic Waves in Thermoelastic Plates with Thermal Relaxation Times
K.L VermaIn this paper, analysis for the propagation of general anisotropic media of finite thickness with two thermal relaxation times is studied. Expression of displacements, temperature, thermal stresses, and thermal gradient for most general anisotropic thermoelastic plates أکثرIn this paper, analysis for the propagation of general anisotropic media of finite thickness with two thermal relaxation times is studied. Expression of displacements, temperature, thermal stresses, and thermal gradient for most general anisotropic thermoelastic plates of finite thickness are obtained in the analysis. The calculation is then carried forward for slightly more specialized case of a monoclinic plate. Dispersion relations for symmetric and antisymmetric wave modes are obtained. Thermoelastic plates of higher symmetry are contained implicitly in the analysis. Numerical solution of the frequency equation for a representative plate of assigned thickness is carried out, and the dispersion curves for the few lower modes are presented. Coupled thermoelastic thermal motions of the medium are found dispersive and coupled with each other due to the thermal and anisotropic effects. Some special cases have also been deduced and discussed. تفاصيل المقالة -
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9 - Dynamic Behavior of Anisotropic Protein Microtubules Immersed in Cytosol Via Cooper–Naghdi Thick Shell Theory
M.R Ghorbanpour Arani Z Khoddami Maraghi E HaghparastIn the present research, vibrational behavior of anisotropic protein microtubules (MTs) immersed in cytosol via Cooper–Naghdi shell model is investigated. MTs are hollow cylindrical structures in the eukaryotic cytoskeleton which surrounded by filament network. Th أکثرIn the present research, vibrational behavior of anisotropic protein microtubules (MTs) immersed in cytosol via Cooper–Naghdi shell model is investigated. MTs are hollow cylindrical structures in the eukaryotic cytoskeleton which surrounded by filament network. The temperature effect on vibration frequency is also taken into account by assuming temperature-dependent material properties for MTs. To enhance the accuracy of results, strain gradient theory is utilized and the motion equations are derived based on Hamilton’s principle. Effects of various parameters such as environmental conditions by considering the surface traction of cytosol, length scale, thickness and aspect ratio on vibration characteristics of anisotropic MTs are studied. Results indicate that vibrational behavior of anisotropic MTs is strongly dependent on longitudinal Young’s modulus and length scale parameters. The results of this investigation can be utilized in the ultrasonic examine of MT organization in medical applications particularly in the treatment of cancers. تفاصيل المقالة -
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10 - Application of iterative Jacobi method for an anisotropic di usion in image processing
M. Knanian A. DavariImage restoration has been an active research area. Di erent formulations are e ective in high qualityrecovery. Partial Di erential Equations (PDEs) have become an important tool in image processingand analysis. One of the earliest models based on PDEs is Perona-Malik m أکثرImage restoration has been an active research area. Di erent formulations are e ective in high qualityrecovery. Partial Di erential Equations (PDEs) have become an important tool in image processingand analysis. One of the earliest models based on PDEs is Perona-Malik model that is a kindof anisotropic di usion (ANDI) lter. Anisotropic di usion lter has become a valuable tool indi erent elds of image processing specially denoising. This lter can remove noises without degradingsharp details such as lines and edges. It is running by an iterative numerical method. Therefore, afundamental feature of anisotropic di usion procedure is the necessity to decide when to stop theiterations. This paper proposes the modied stopping criterion that from the viewpoints of complexityand speed is examined. Experiments show that it has acceptable speed without su ering from theproblem of computational complexity. تفاصيل المقالة -
حرية الوصول المقاله
11 - Experimental, Franc2d, and DDM simulation to determine the anisotropic tensile strength of brittle material
Vahab Sarfarazi Hadi HaeriIn this paper, a compression-to-tensile load converter device is developed to determine the anisotropic tensile strength of brittle material. A cubic sample with an internal pore was used as the test specimen, and a series of finite element analysis and DDM simulations أکثرIn this paper, a compression-to-tensile load converter device is developed to determine the anisotropic tensile strength of brittle material. A cubic sample with an internal pore was used as the test specimen, and a series of finite element analysis and DDM simulations were performed thereafter to analyse the effect of pore dimensions on the stress concentration, as well as to render a suitable criterion for determining the anisotropic tensile strength of concrete. The results obtained by this device show that the tensile strength of concrete is similar in different directions because of the homogeneity of bonding between the materials. تفاصيل المقالة -
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12 - Designing an adjustable optical multi-channel filter in a triple photonic structure based on magnetized materials and uniaxial metamaterials
Behnam KazempourIn this article, the adjustability of the multi-channel optical filter including magnetized materials and uniaxial anisotropic metamaterials in the three-dimensional one-dimensional photonic crystal structure in the GHz frequency range has been theoretically analyzed an أکثرIn this article, the adjustability of the multi-channel optical filter including magnetized materials and uniaxial anisotropic metamaterials in the three-dimensional one-dimensional photonic crystal structure in the GHz frequency range has been theoretically analyzed and designed. It is shown that resonant peaks in the transmission spectrum can be created in the presented structure without adding a defect layer, in the absence and presence of an external magnetic field. Therefore, the presented ternary periodic structure can act as an adjustable multi-channel filter using the transmission spectrum of the photonic crystal. Also, the characteristics of the transmission spectrum of the assumed structure can be manipulated by applying an external magnetic field, so that the frequency of the channels can be red-shifted or blue-shifted depending on the direction of the applied magnetic field. In addition, the effect of the number of periods of the structure, the optical axis angle of anisotropic metamaterials (φ) and the incident light radiation angle (θ) on the filtering characteristics of the channels in both TE and TM polarizations have been numerically investigated تفاصيل المقالة -
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13 - Relativistic Stellar Models with Quadratic Equation of State
Manuel Malaver Hamed Daei KasmaeiIn this paper, we have obtained and presented new relativistic stellar configurations considering an anisotropic fluid distribution with a charge distribution and a gravitational potential Z(x) that depends on an adjustable parameter. The quadratic equation of state bas أکثرIn this paper, we have obtained and presented new relativistic stellar configurations considering an anisotropic fluid distribution with a charge distribution and a gravitational potential Z(x) that depends on an adjustable parameter. The quadratic equation of state based on Feroze and Siddiqui viewpoint is used for the matter distribution. The new solutions can be written in terms of elementary and polynomial functions. We have investigated that the radial pressure, metric coefficients, energy density, anisotropy factor, charge density, mass function have been well defined and are regular in the interior of these new models, which satisfy all physical properties in a realistic star. تفاصيل المقالة -
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14 - Anisotropic Charged Stellar Models
Kalikkuddy KomathirajA new class of exact solutions of the Einstein-Maxwell system is found in closed form for a static spherically symmetric anisotropic star in the presence of an electric field by generalizing earlier approaches. The field equations are integrated by specifying one of the أکثرA new class of exact solutions of the Einstein-Maxwell system is found in closed form for a static spherically symmetric anisotropic star in the presence of an electric field by generalizing earlier approaches. The field equations are integrated by specifying one of the gravitational potentials, the anisotropic factor and electric field which are physically reasonable. We demonstrate that it is possible to obtain a more general class of solutions to the Einstein-Maxwell system in the form of series with anisotropic matter. For specific parameter values it is possible to find new exact models for the Einstein-Maxwell system in terms of elementary functions from the general series solution. Our results contain particular solutions found previously including models of Thirukkanesh and Maharaj (2009) and Komathiraj and Maharaj (2007) charged relativistic models. تفاصيل المقالة -
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15 - Buckling Analysis of Orthotropic and Anisotropic Rectangular Plates by GDQ Method
محسن فتاحی فاطمه فرهت نیا منصور درویزهIn this paper, buckling of orthotropic rectangular plates under different loadings was investigated. For this reason, governing buckling equations for an isotropic plate were modified by applying constitutive equations of orthotropic materials. After obtaining the equat أکثرIn this paper, buckling of orthotropic rectangular plates under different loadings was investigated. For this reason, governing buckling equations for an isotropic plate were modified by applying constitutive equations of orthotropic materials. After obtaining the equations of orthotropic plates, Generalized Differential Quadrature method (GDQM) was applied on buckling equations and thus a set of Eigen value equations resulted. In order to solve this Eigen value problem, a computer program was developed using MATLAB software in a way that the influence of different parameters such as length to width ratio (aspect ratio), the number of layers, the angle of layers arrangement, material of layers, kind of loading and boundary conditions were included. A buckling load factor was calculated for simply supported and clamped supported plates. The results of GDQ method were compared with reported results from Rayleigh – Ritz method and with results from solving the Finite element using ANSYS 8.0 software. The comparison showed the accuracy of obtained result clearly. تفاصيل المقالة -
حرية الوصول المقاله
16 - Buckling Analysis of Orthotropic and Anisotropic Rectangular Plates by GDQ Method
حسن مسلمی نائینی مهدی تاجداری سیامک مزدک ولی اله پناهی زادهIn this paper, buckling of orthotropic rectangular plates under different loadings was investigated. For this reason, governing buckling equations for an isotropic plate were modified by applying constitutive equations of orthotropic materials. After obtaining the equat أکثرIn this paper, buckling of orthotropic rectangular plates under different loadings was investigated. For this reason, governing buckling equations for an isotropic plate were modified by applying constitutive equations of orthotropic materials. After obtaining the equations of orthotropic plates, Generalized Differential Quadrature method (GDQM) was applied on buckling equations and thus a set of Eigen value equations resulted. In order to solve this Eigen value problem, a computer program was developed using MATLAB software in a way that the influence of different parameters such as length to width ratio (aspect ratio), the number of layers, the angle of layers arrangement, material of layers, kind of loading and boundary conditions were included. A buckling load factor was calculated for simply supported and clamped supported plates. The results of GDQ method were compared with reported results from Rayleigh – Ritz method and with results from solving the Finite element using ANSYS 8.0 software. The comparison showed the accuracy of obtained result clearly. تفاصيل المقالة
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