The objective of this work was to develop a fast and significant method for the determination of the intraparticulate pore size distribution of microspheres. Poly(lactide-co-glycolide) (PLGA) microspheres prepared with a solvent extraction/evaporation process were studied. From the envelope and the skeletal volume of the microspheres the porosity was calculated. The skeletal volume was determin...

The modern engineering structures require the advanced engineering materials to resist the high temperatures and to provide high stiffness. In particular the functionally graded porous materials (FGPMs) introduced are expected to have these desired properties, consequently eliminating local stress concentration and de-lamination. In the present paper, a new shear strains shape function is chose...

Scaffolds from poly(ethylene oxide) and poly(butylene terephthalate), PEOT/PBT, with a PEO molecular weight of 1,000 and a PEOT content of 70 weight% (1000PEOT70PBT30) were prepared by leaching salt particles (425-500 microm). Scaffolds of 73.5, 80.6 and 85.0% porosity were treated with a CO(2) gas plasma and seeded with rat bone marrow stromal cells (BMSCs). After in vitro culture for 7 days (...

In the present study, traditional and hybrid composites were prepared by Hand lay-up molding and investigated. The composites constituents were unsaturated polyester resin as the matrix, 3% and 6% volume fractions of carbon fibers as reinforcement and 3% of Al2O3, Al, Cement and local Gypsum (calcium sulfate anhydrate CaSO4) as filler particles. The investigated physical properties were density...

The Earth’s mantle (or, e.g., a glacier) involves a deformable solid matrix phase within which a second phase, a fluid, may form due to melting processes. The system is modeled as a dual-continuum mixture, with at each point of space the solid matrix being governed by a Stokes flow and the fluid melt, if it exists, being governed by Darcy’s law. This system is mathematically degenerate when the...

The volume of the intrafibrillar water space--i.e. the water contained inside the collagen fibres--is a key parameter that is relevant to concepts of connective tissue structure and function. Confined compression and swelling experiments on annulus fibrosus samples are interpreted in terms of a dual porosity model that distinguishes between a non-ionised intrafibrillar porosity and an ionised e...

An experiment was carried out in order to locate and quantify osteon types within a sample of cortical bone taken from a human tibia. This was done using a microscope-camera assembly and the BioQuant computer software. The results of this were correlated with a previous experiment's results on fracture toughness so that an analysis could be run on the data in order to determine the factors that...

the main purpose of this study is to perform numerical simulation of nanofluids as the coolant in vver-440 fuel rod bundle. the fuel rod bundle contains 60 fuel rods with length of 960 mm and 4 spacer grids. in vver-440 fuel rod bundle the coolant fluid (water) is in high pressure and temperature condition. in the present thermo-hydraulic simulation, water-al2o3 nanofluids containing various vo...

introduction: we investigated the difference in left ventricular ejection fraction (lvef) and end-systolic volume(esv) measured by gated myocardial perfusion spect (gspect) in the post-dipyridamole stress and rest periods, and compared the results with the perfusion patterns found in the conventional non-gated tomograms. methods: 297 consecutive patients were studied with post-stress and rest 9...

Synopsis The impaired strength of osteoporotic cortical bone is largely a consequence of increased porosity, which manifests in increased bone water fraction. Hence, knowledge of bone water (BW) content would provide an indirect measure of pore volume fraction. Surface interactions in the tight spaces of the lacuno-canalicular system shorten the lifetime of the BW proton signal to less than 1ms...