a two-dimensional (2d) single particle model for the copolymerization of propylene-ethylene with heterogeneous ziegler-natta catalyst is developed. the model accounts for the effects of the initial shape of the catalyst and carck/ pore patterns on the copolymer composition, polymerization rate and the average molecular weight properties. the spherical and oblate ellipsoidal shapes of catalyst p...

static analysis of sandwich constructions subjected to pressure and concentrated loads with the use of finite element method has been discussed in this paper. because of difficulties involved in analytical solution for most of the practical problems. an efficient computer programs has been developed that can be executed on a pc/xt computer and solves complicated problems easily and economically...

finite and boundary element methods have been used by many authors to solve mathematicalphysics problems. however, the coupling of these two methods happens to be more efficient as it combinestheir merits. in this paper, the mathematical analysis of the coupling of finite and boundary element methodsfor the helmholtz equation is presented.

this work is conducted to obtain mechanical properties of microtubule. for this aim, interaction energy in alpha-beta, beta-alpha, alpha-alpha, and beta-beta dimers was calculated using the molecular dynamic simulation. force-distance diagrams for these dimers were obtained using the relation between potential energy and force. afterwards, instead of each tubulin, one sphere with 55 kda weight ...

In this paper the damage location in beam like-structure is determined using static and dynamic data obtained using finite volume method. The change of static and dynamic displacement due to damage is used to establish an indicator for determining the damage location. In order to assess the robustness of the proposed method for structural damage detection, three test examples including a static...

This paper begins with presenting a mathematical model for contaminant transport in the fractured vuggy porous media of a species of contaminant PCP . Two phases are numerically simulated for a process of contaminant and clean water infiltrated in the fractured vuggy porous media by coupling mixed finite element MFE method and finite volume method FVM , both of which are locally conservative, t...

soil slopes are sometimes curved in plan rather than being straight. this curvature,especially when it is convex, decreases the bearing capacity of the slope. finite element methodhas been used here in this research to investigate the reducing effect of curvature on bearingcapacity of a slope. failure of soil has been assumed to be according to mohr-coulomb criteria;but the flow rule of the soi...