The electric field gradient (EFG) has been calculated in zeolite clusters at the aluminium site surrounded by four SiO4 tetrahedra. Density functional theory (DFT) with the 6-31G** basis set has been employed. Formation of a Brønsted acid site by protonation of one oxygen atom of the AlO4 tetrahedron perturbs the coordination of aluminium, i.e., the corresponding Al-O bond is considerably weake...

A meshless approach to the analysis of arbitrary Kirchhoff plates by the Element-Free Galerkin (EFG) method is presented. The method is based on moving least squares approximant. The method is meshless, which means that the discretization is independent of the geometric subdivision into “finite elements”. The satisfaction of the C1 continuity requirements are easily met by EFG since it requires...

The electric field gradients (EFG) in aluminium due to a monovacancy and the interstitial muon are evaluated. The valence effect EFG q is calculated using perturbed electron density ön(r) values obtained from density functional theory in an analytic expression which is valid at all distances from the impurity. The size effect E F G q is evaluated using a new oscillatory form for the near neighb...

We consider numerical solutions of second-order elliptic partial di erential equations, such as Laplace's equation, or linear elasticity, in two-dimensional, non-convex domains by the element-free Galerkin method (EFG). This is a meshless method, in which the shape functions are constructed by using weight functions of compact support. For non-convex domains, two approaches to the determination...

A meshless approach to the analysis of arbitrary Kirchhoff shells by the Element-Free Galerkin (EFG) method is presented. The shell theory used is geometrically exact and can be applied to deep shells. The method is based on moving least squares approximant. The method is meshless, which means that the discretization is independent of the geometric subdivision into “finite elements”. The satisf...

The development of stability problems related to classical mixed methods has recently been observed. In this study, a soil-water coupled boundary-value problem, one type of stability problem, is presented using the Element-free Galerkin Method (EFG Method). In this soil-water coupled problem, anomalous behavior appears in the pressure field unless stabilization techniques are used. The remedy t...

for three different back surface recombination velocities (BSRV). The calculations reveal that the carrier lifetime limits the screen-printed (SP) EFG Si cell efficiency for lifetimes below -30 /-Is. For a 300 /-1m thick device, the carrier lifetime should be greater than 30 /-Is to realize the full benefit of a low BSRV. Therefore, lifetime enhancement is essential for achieving high efficienc...

Let G be a group hyperbolic relative to a finite collection of subgroups P. Let F be the family of subgroups consisting of all the conjugates of subgroups in P, all their subgroups, and all finite subgroups. Then there is a cocompact model for EFG. This result was known in the torsion-free case. In the presence of torsion, a new approach was necessary. Our method is to exploit the notion of dis...