objective: repair of an indirect restoration is usually preferred over its replacement. this study aimed to evaluate the effect of silane in different surface preparation techniques on the bond strength of direct to indirect composite resin.   methods: for this in vitro experimental study, 48 indirect composite cubes were fabricated, divided into 4 groups of 12 and subjected to the following pr...

The reconstruction mechanism of (001) fcc transition metal surfaces is investigated using a full-potential all-electron electronic structure method together with density-functional theory. Total-energy calculations confirm the experimental finding that a close-packed quasi-hexagonal overlayer reconstruction is possible for the late 5d-metals Ir, Pt, and Au, while it is disfavoured in the isoval...

by considering the fact that the surface tension of a real fluid arises from a combination of both repulsive and attractive forces between molecules, a new expression for the interfacial tension has been derived from scaled particle theory (spt)  based on the work of cavity formation and the interaction energy between molecules. at the critical temperature, the interfacial tension between coexi...

background and aims. the aim of this study was to determine the stress patterns within an implant and the effect of different types of connections on load transfer. materials and methods. three different types of implant-abutment connections were selected for this study. sample a: 1.5-mm deep internal hex corresponding to a lead-in bevel; sample b: a tri-channel internal connection; and sample ...

We examine the surface morphological evolution of a conducting crystalline solid under the simultaneous action of an electric field and mechanical stress based on a fully nonlinear model and combining linear stability theory with self-consistent dynamical simulations. We demonstrate that electric current, through surface electromigration, can stabilize the surface morphology of the stressed sol...

The best known isotropic membrane stress state is a soap film. However, if we allow the value of the isotropic stress to vary from point to point then the surface can carry gravity loads, either as a hanging form in tension, or as a masonry shell in compression. The paper describes the theory of isotropic membrane stress under gravity load and introduces a particle method for its numerical simu...

in classical mechanics, considering hook’s law stress is a linear function of strain. while in strain gradient theory stress is a function of strain and strain differentials. in this paper, novel formulation relating stress and strain and also new boundary conditions are derived based on minimum potential energy principle. in strain gradient theory a length coefficient parameter is defined. thi...

A summary is first presented of the conceptual difficulties and paradoxes surrounding plastic bifurcation buckling analysis. Briefly discussed are nonconservativeness, loading rate during buckling, and the discrepancy of buckling predictions with use of .I2 flow theory vs JZ deformation theory. The axisymmetric prebuckling analysis, including large deflections, elastic-plastic material behavior...

The impetus of this study is to investigate the chaotic behavior of a size-dependent nano-beam with double-sided electrostatic actuation, incorporating surface energy effect and intermolecular interactions. The geometrically nonlinear beam model is based on Euler-Bernoulli beam assumption. The influence of the small-scale and the surface energy effect are modeled by implementing the consistent ...