Semi-solid materials undergo strain localization and shear band formation as a result of granular nature of semi-solid deformation. In the present study, to analyze the shear localization, a unified viscoplastic constitutive model was developed for the homogeneous flow. Then, a linearized analysis of the stability performed by examining the necessary condition for the perturbation growth. For t...

Mn doped ZnO nanocrystals were prepared by co-precipitation route sintered at 450 °C temperature. XRD results indicate that the samples having hexagonal (wurtzite) structure. From X-ray data it is found that the lattice parameters increase with increasing Mn concentration. The X-ray density decreases with increasing Mn concentration of Zn 1-x Mnx O nanocrystals. It indicates that the Mn...

Tubular channel angular pressing (TCAP) is a recently invented novel severe plastic deformation technique for producing UFG tubes. Plastic deformation analysis using the finite element method (FEM) was carried out to investigate the effects of trapezoidal channel geometry on strain inhomogeneity index (SII), strain level and required load compared to previously used channel geometries. The resu...

In the slitting method, a small width slit is created incrementally through the thickness of the stressed specimen and the released strains in each increment are recorded by a strain gauge. Compliance coefficients relate the measured strains to the residual stresses. This paper investigates the important parameters influencing the calculation of compliance coefficients for isotropic plates and ...

Background and Aim: Dental implants with angled abutments are often inserted in the anterior maxillary region due to the status of the residual ridge and aesthetic considerations. The purpose of this study was to assess stress and strain distributions in the premaxillary bone around dental implants by means of finite element analysis (FEA). Materials and Methods: Four three-dimensional (3D) fi...

background: various techniques are used in diagnosing cardiac diseases. the electrocardiogram is one of these tools in common use. in this study vectorcardiogram ) vcg ( signals are used as a tool for detection of cardiac ischemia. methods: vcg signals used in this study were obtained form 60 patients suspected to have ischemia disease and 10 normal candidates. verification of the ischemia had ...

rapid detection and differentiation of infectious bronchitis virus (ibv) involved in the disease outbreak is very important for controlling disease and developing new vaccines. in the present study, three regions of the genome of ibv vaccine and field isolates including s1 gene, gene 3 and nucleocapsid (n) gene along with 3' untranslated region (3' utr) were amplified and subjected to restricti...

Abstract: In the current work, the strain hardening behavior of dual-phase steels with different silicon content (0.34- 2.26 Wt. %) was examined using the modified Crussard-Jaoul analysis. It was shown that these dual-phase steels deform in two stages over a uniform strain range. Each stage exhibited a different strain hardening exponent varying with silicon content. At the first stage, work...

The paper is concerned with a methodology of optimal design of shells of minimum weight with strength, stability and strain constraints. Stress and strain state of the shell is determined by Galerkin method in the mixed finite element formulation within the geometrically nonlinear theory. The analysis of the effectiveness of different optimization algorithms to solve the set problem is given. T...