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...

[1] Previous field-scale experimental data and numerical modeling suggest that the dual-domain mass transfer (DDMT) of electrolytic tracers has an observable geoelectrical signature. Here we present controlled laboratory experiments confirming the electrical signature of DDMT and demonstrate the use of time-lapse electrical measurements in conjunction with concentration measurements to estimate...

[1] Measurements have been made of the effect of compaction on water retention, saturated hydraulic conductivity, and porosity of two English soils: North Wyke (NW) grassland clay topsoil and Broadbalk silty topsoil, fertilized inorganically (PKMg) or with farmyard manure (FYM). As expected, the FYM topsoil had greater porosity and greater water retention than PKMg topsoil, and the NW clay tops...

[1] A discrete fracture model for the flow of compressible, multicomponent fluids in homogeneous, heterogeneous, and fractured media is presented in single phase. In the numerical model we combine the mixed finite element (MFE) and the discontinuous Galerkin (DG) methods. We use the cross-flow equilibrium concept to approximate the fractured matrix mass transfer. The discrete fracture model is ...

Calcium phosphate cements (CPCs) were prepared using mixtures of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA), with TTCP/DCPA molar ratios of 1/1, 1/2, or 1/3, with the powder and water as the liquid. Diametral tensile strength (DTS), porosity, and phase composition (powder x-ray diffraction) were determined after the set specimens have been immersed in a physiological...

Prolonged bedrest and microgravity induce alterations to bone, leading to bone fragility and compromising the quality of life. In this study, we characterized the physicochemical changes, microstructure, and biomechanics of the femurs of female adult rats in response to hindlimb unloading for 21 days. Twenty 6-month-old Wistar female rats were distributed into control (CON) and hindlimb unloadi...

Aligned electrospun scaffolds are promising tools for engineering fibrous musculoskeletal tissues, as they reproduce the mechanical anisotropy of these tissues and can direct ordered neo-tissue formation. However, these scaffolds suffer from a slow cellular infiltration rate, likely due in part to their dense fiber packing. We hypothesized that cell ingress could be expedited in scaffolds by in...

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...

As part of the European Hot Dry Rocks Project, a second exploration borehole, EPS-1, has been cored to a depth of 2227 m at Soultz-sous-For@ts (France). The target was a granite beginning at 1417 m depth, overlain by post-Paleozoic sedimentary cover. Structural analysis and petrographic examination of the 800-111 porphyritic granite core, have shown that this rock has undergone several periods ...

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...