The generalized Fick-Jacobs equation is widely used to study diffusion of Brownian particles in three-dimensional tubes and quasi-two-dimensional channels of varying constraint geometry. We show how this equation can be applied to study the slowdown of unconstrained diffusion in the presence of obstacles. Specifically, we study diffusion of a point Brownian particle in the presence of identical...

Composites of concentric cylinders can fail by microcracks that span the thickness and length of one cylinder but arrest at the boundary to adjacent cylinders. This failure mode was analyzed by developing a new polar shear-lag analysis for stresses in a cross section of a concentric-cylinder composite. The analysis can accurately calculate stresses in each cylinder in the presence of microcrack...

in the present research, nonlinear vibration in a coupled system of boron-nitride nano-tube reinforced composite (bnntrc) oil pipes is studied. single-walled boron-nitride nano-tubes (swbnnts) are arranged in a longitudinal direction inside poly-vinylidene fluoride (pvdf) matrix. damping and shearing effects of surrounded medium are taken into account by visco-pasternak model. based on piezoele...

This in vitro study analyzed the effect of different load application devices on fracture resistance and failure mode of maxillary premolars restored with composite resin. Sixty human maxillary premolars received standardized mesio-occluso-distal cavity preparations and were restored with composite resin. The specimens were randomly divided into 6 groups (n=10). Compressive loading was applied ...

Abstract One of the applications composites is in manufacturing tubes, which are widely used industries such as petroleum, petrochemical, and aerospace. Composite tubes made thermoset resin base material reinforced by fibers, having a solid, lightweight, corrosion-resistant structure, great replacement for metal concrete tubes. In this research, composite with various resins material, Swancor90...

Axisymmetric vibration of an infinite piezolaminated multilayer hollow cylinder made of piezoelectric layers of 6mm class and an isotropic LEMV Linear Elastic Materials with Voids layers is studied. The frequency equations are obtained for the traction free outer surface with continuity conditions at the interfaces. Numerical results are carried out for the inner, middle, and outer hollow piezo...

The aim is to present our new method of compression, a compression tube instead of conventional compression screw and to investigate the difference of proximal locking screw bending resistance between compression screw application (6 mm wide contact) and compression tube (two contact points with 13 mm gap) application. We formed six groups each consisting of 10 proximal locking screws. On metal...

We suggest that long-distance Yang-Mills theory is more conveniently described in terms of electric rather than the customary magnetic vector potentials. On this basis we propose as an effective Lagrangian for this regime the most simple gauge-invariant (under the magnetic rather than electric gauge group) and Lorentz-invariant Lagrangian which yields a 1 I q 4 gluon propagator in the Abelian l...