the natural vibrations of clamped annular isotropic sector plates are analyzed using the extended kantorovich method (ekm). a conformal mapping is used to transform a sector with identified geometry to a rectangular plate which the solution is available in literature and solved by dalaei and kerr [1] using ekm. the developed iterative scheme converges very rapidly to the final result. the obtai...

In this article, one-phase and three dimensional computational fluid dynamics analysis was utilized to investigate the effect of annular field pattern of proton exchange membrane fuel cells (PEMFC) with different geometry on the performances and species distribution. This computational fluid dynamics code is used for solving the equation in single domain namely the flow field, the mass conserva...

Altering the geometry of microelectrodes for use in a cortical neural prosthesis modifies the electric field generated in tissue, thereby affecting electrode efficacy and tissue damage. Commonly, electrodes with an active region located at the tip ("conical" electrodes) are used for stimulation of cortex but there is argument to believe this geometry may not be the best. Here we use finite elem...

A pseudo-line D-T neutron source has been developed with new experimental techniques. This line source was applied in sophisticated neutronics experiments for an annular blanket arrangement simulating the tokamak geometry, as a new series in the JAERI/USDOE collaborative experimental program on fusion neutronics. The source characteristics of the present line source and the measurements for an ...

BACKGROUND Although animal studies showed that annular remodeling may be related to the pathogenesis of chronic ischemic mitral regurgitation (CIMR), little was known in humans. A better understanding of the precise 3D geometry of the mitral valvular-ventricular complex in CIMR is needed to devise a better surgical technique. The purpose of the study was to elucidate mitral annular geometry in ...

This publication documents the development status of the Annular-Geometry Ion Engine (AGI-Engine). The AGI-Engine is the design core for a new class of electric propulsion thrusters, referred to as the Next-Generation Electric Propulsion Thruster (NGEPT). The NGEPT is a single thruster concept, implementing an annular ring architecture, which potentially can be scaled and adapted for any power ...

This work investigates a strongly-focused annular array for high frequency ultrasonic applications, offering improved resolution without increasing the operating frequency, potentially reducing the complexity of manufacture. However, the conventional geometry, specifically the Equal Area array exhibits a problem with high sidelobes. A method based on geometric change is developed to control the...