Efficient heat transfer of concentrated solar energy and rapid chemical kinetics are desired characteristics of solar thermochemical redox cycles for splitting CO2. We have fabricated reticulated porous ceramic (foam-type) structures made of ceria with dual-scale porosity in the millimeter and micrometer ranges. The larger void size range, with dmean = 2.5 mm and porosity = 0.76-0.82, enables v...

Attachment of 111Indium-oxine labeled cultured canine venous endothelial cells to expanded polytetrafluorethylene (ePTFE) grafts was evaluated in vitro. Three alternative seeding techniques were studied in grafts having different diameters, porosities, and surfaces, including: (I) manual milking of blood containing endothelial cells within the graft; (II) a two-step procedure of incubating graf...

Spatial statistics of earth and environmental (as well as many other) data tend to vary with scale. Common manifestations of scale-dependent statistics include a tendency of increments to have symmetric, non-Gaussian frequency distributions characterized by heavy tails that decay with separation distance or lag; power-law scaling of sample 5 structure functions (statistical moments of absolute ...

BACKGROUND AND PURPOSE Endovascular treatment of wide-neck bifurcation aneurysms often results in incomplete occlusion or aneurysm recurrence. The goals of this study were to compare results of coil embolization with or without the assistance of self-expandable stents and to examine how stents may influence neointima formation. MATERIALS AND METHODS Wide-neck bifurcation aneurysms were constr...

emptied and washed, and the 24h efflux of inulin was determined; it is plotted against the final swelling ratio from the experiment in which the sac was stretched. An unstretched control is also included. In a similar unstretched sac, the half-time of raffinose escape was I4Omin. Clearly inulin escapes faster than the polyethylene glycol of comparable molecular weight at all porosities, but at ...

The pulsed field gradient technique of NMR (PFG NMR) is applied to explore molecular diffusion in different specimens of zeolite NaCaA, notably in samples containing hierarchical pore systems, as well in a silica material with an ordered, bimodal mesopore structure. In the hierarchical zeolithes the diffusivities in the two pore spaces are measured separately from each other by choosing ethane ...

We compare the quantitative microstructural properties of Berea Sandstone with stochastic reconstructions of the same sandstone. The comparison is based on local porosity theory. The reconstructions employ Fourier space filtering of Gaussian random fields and match the average porosity and two-point correlation function of the experimental model. Connectivity properties of the stochastic models...