Some prosthetic heart valves with Silastic ball poppets undergo degeneration and variance. The problem is avoided with metal poppets; however, their impact can damage the cloth coverings on the struts, resulting in distorted blood flow paths. Consequently, renewed interest in mOd-cured Silastic poppets and inserts is developing. With photostress equipment, we analyzed two spherical poppet model...

This paper proposes an effective numerical method to study cavitation instabilities in non-linear elastic solids. The basic idea is to examine—by means of a 3D finite element model—the mechanical response under affine boundary conditions of a block of non-linear elastic material that contains a single infinitesimal defect at its center. The occurrence of cavitation is identified as the event wh...

Nilsson et al. have recently shown how a velocity field in geostrophic and hydrostatic balance in an f -plane may be diagnosed from prescribed distributions of buoyancy and wind stress, in a basin with closed isobaths. I extend their analysis to cover basins with more complex depth contours, treating in particular the behavior of the flow in the presence of a saddle point.

Nilsson et al. have recently shown how a velocity field in geostrophic and hydrostatic balance in an f -plane may be diagnosed from prescribed distributions of buoyancy and wind stress, in a basin with closed isobaths. I extend their analysis to cover basins with more complex depth contours, treating in particular the behavior of the flow in the presence of a saddle point.

The objective of the present project was to study how high temperatures affect the different mechanical parameters of chalks. The general result is that both cohesion and the hydrostatic yield stress are typically reduced about 20 % in going from 20 to 130 C, but the magnitude of this reduction may be chalk type dependent.

PURPOSE To determine whether oxidative adduct formation or heme oxygenase-1 (HO-1) expression are altered in retinal ganglion cell (RGC) cultures exposed to elevated hydrostatic pressure and in a mouse model of glaucoma. METHODS Cultured RGC-5 cells were subjected to 0, 30, 60, or 100 mm Hg hydrostatic pressure for 2 hours, and the cells were harvested. Parallel experiments examined the recov...

We present an experimental and numerical study on the influence that particle aspect ratio has on the mechanical and structural properties of granular packings. For grains with maximal symmetry (squares), the stress propagation in the packing localizes forming chainlike forces analogous to the ones observed for spherical grains. This scenario can be understood in terms of stochastic models of a...

Pressure-induced phase transitions in cubic Eu2O3 subjected to non-hydrostatic conditions have been studied by situ high-pressure synchrotron angle dispersive x-ray diffraction and Raman scattering measurements up 30.1 43.8 GPa, respectively. Both spectroscopy results indicate that the pressure-induced transition routines of depend on nature stress loading. In contrast our previous studies unde...