slab method of analysis has been used for solving metal forming problems for a long time. however it has been restricted to plane strain and axisymmetric problems due to limitations in its formulations. in this paper a new formulation has been proposed so that it could be applied to three dimensional problems in metal forming. a parametric slab has been considered in this analysis and the force...

abstractthe liquid crystal director distribution is determined for a confined chiral nematic slab. the molecular director distribution of the field-controlled chiral nematic slab is directly calculated. the director profiles for the tilt and the twist angles, under different applied fields, are calculated in the slab with weak boundary conditions. then, the dependence of the threshold field on ...

An ultrasonic reflectivity method is proposed for measuring porosity and tortuosity of porous materials having a rigid frame. Porosity is the relative fraction by volume of the air contained within a material. Tortuosity is a geometrical parameter which intervenes in the description of the inertial effects between the fluid filled the porous material and its structure at high frequency range. I...

We present the analytic calculation of the cross-spectral density tensor of a thermally radiative planar dielectric slab in extreme near-field, intermediate near-field, and far-field zones. We show that the spatial coherence of the thermal field exhibits distinct features in these zones. At a given wavelength lambda , the coherence length is many orders of magnitude smaller than lambda in the e...

Reinforced concrete (RC) slabs exhibit complexities in their structural behavior under load due to the composite nature of the material and the multitude and variety of factors that affect such behavior. Current methods for determining the load-deflection behavior of reinforced concrete slabs are limited in scope and are mostly dependable on the results of experimental tests. In this study, an ...

The subject of enhancing microstrip patch antennas directivity, using either a frequency selective surface (FSS) or a double-negative (DNG) metamaterial slab, has been investigated by a number of researchers in recent years. The purpose of this paper is to show that we can also achieve the same goal by using a much simpler design for the superstrate, namely a dielectric slab, whose performance ...

We propose a novel concept for creating high-Q cavities in photonic crystal slabs (PCS). We show that photonic crystal slab-based double heterostructure cavities, formed by variations in the refractive index, can have large a Q-factor (up to Q = 1× 10), and that such cavities can be implemented in chalcogenide glasses using their photosensitive properties. DOI: 10.2529/PIERS060907042030 In the ...

An exact infinite set of coupled ordinary differential equations, describing the evolution of the modes of the classical electromagnetic field inside an ideal cavity, containing a thin slab with the time-dependent conductivity σ(t) and dielectric permittivity ε(t), is derived for the dispersion-less media. This problem is analyzed in connection with the attempts to simulate the so called Dynami...