In support for the ISO Mission it has been necessary to establish a set of asteroids as photometric standards for the photometric calibration of the instruments (M uller & Lagerros 1998). The new standards are described as rotating ellipsoids. Illumination geometry, heat transfer due to non-zero thermal inertia and surface structure/porosity are taken into account. The characteristic properties...

Acellular biological tissues, including bovine pericardia (BP), have been proposed as natural biomaterials for tissue engineering. However, small pore size, low porosity and lack of extra cellular matrix (ECM) after native cell extraction directly restrict the seed cell adhesion, migration and proliferation and which is a vital problem for ABP's application in the tissue engineered heart valve ...

The effects of a porous fence with a nonuniform porosity on flow fields are investigated numerically. First, an experiment with a non-uniform porous fence located in a wind tunnel is performed to obtain a reference data set. Then, a numerical model that utilizes the finite volume schemewith a weakly compressible-flowmethod to solve the continuity and momentum equations is developed. The numeric...

Some key parameters of supports such as porosity, pore shape and size are of great importance for fabrication and performance of zeolite membranes. In this study, we fabricated millimetre-thick, self-standing electrospun ceramic nanofibre mats and employed them as a novel support for zeolite membranes. The nanofibre mats were prepared by electrospinning a halloysite nanotubes/polyvinyl pyrrolid...

A theoretical analysis has been carried out to study efficient microwave heating of porous dielectrics. The heating effects are analyzed for two types of porous material: beef-air (b/a) and beef-oil (b/o) with and without ceramic supports (Al2O3 and SiC). Three test cases for porosities (/) 0.3, 0.45 and 0.6 are considered. The maxima in average power corresponding to resonances occur at variou...

increase in the surface area, demonstrating that the Fe(III) ions work by making the resin porous. The use of these two metal ions enables efRcient NO adsorption. The polymeric resin as well as the metal complex itself greatly affects the adsorbing ability for the target gas molecules as described in the case of CO, C2H4, and NO adsorption. It has been demonstrated clearly that large surface ar...

this study investigated the effect, on reactor performance and biomass retention inside the bed, of the material used to make the supports of anaerobic fixed-bed reactors. three inert supports of similar shape but made of three different materials polyvinyl chloride, polypropylene, high-density polyethylene were manufactured and used. all three supports had the same specific surface area but di...

To unravel how the microstructure affects the fracture surface roughness in heterogeneous brittle solids like rocks or ceramics, we characterized the roughness statistics of postmortem fracture surfaces in homemade materials of adjustable microstructure length scale and porosity, obtained by sintering monodisperse polystyrene beads. Beyond the characteristic size of disorder, the roughness prof...

Monolithic aerogels of high molecular weight polyethylene (Mw= 3x106- 6x106 g/mol) have been prepared by solvent extraction with supercritical carbon dioxide from thermoreversible gels prepared in decalin. These low density and highly porous aerogels present an apparent porosity up to 90%. The aerogel morphology observed by scanning electron microscopy (SEM) is characterized by spherulitic stru...

monolithic aerogels of high molecular weight polyethylene (mw= 3x106- 6x106 g/mol) have been prepared by solvent extraction with supercritical carbon dioxide from thermoreversible gels prepared in decalin. these low density and highly porous aerogels present an apparent porosity up to 90%. the aerogel morphology observed by scanning electron microscopy (sem) is characterized by spherulitic stru...