in this study, doxycycline hyclate release behavior from in situ forming drug delivery systems investigated. these systems based on poly()lactide-co-glycolide)(50:50 dissolved in n-methyl-2-pyrrolidone that were evaluated in different concentrations. these systems are useful for local treatment of periodontal diseases. uv spectroscopy is used to determine drug concentration in release medium. a...

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...

The state of the art of modeling fluid flow in shale reservoirs is dominated by dual porosity models which divide the reservoirs into matrix blocks that significantly contribute to fluid storage and fracture networks which principally control flow capacity. However, recent extensive microscopic studies reveal that there exist massive microand nanopore systems in shale matrices. Because of this,...

oily wastewaters from oil refineries and oil distribution centers are one of the most important environmental concerns in recent decades; therefore, it is critical to treat these types of wastewaters. in this study, the performance of different polyethersulfone hollow fiber membranes in oily wastewaters treatment was investigated and the effects of operating conditions such as transmembrane pre...

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...

Continuous-fiber-reinforced ceramic matrix composites (CMC) have been proposed as candidates for high-temperature applications. Their architecture and network of porosity have a strong effect on the mechanical behavior. X-ray tomography is a non-destructive technique that allows studying the volume mesostructure of these porous materials. The volume porosity, the open porosity fraction, the con...

Growth experiments have been carried out to characterize the occurrence and development of porosity in Bridgman and flux grown Al-Pd-Mn icosahedral quasicrystals. The porosity level has been observed to fluctuate between values of 0.0 and 3.75 percent along the length of Bridgman single crystals implying that the development of porosity is affected by the local growth conditions. Experiments we...

The acoustic properties of porous materials containing dead-end (DE) pores have been proposed by Dupont et al. [J. Appl. Phys. 110, 094903 (2011)]. In the theoretical description, two physical parameters were defined (the dead-end porosity and the average length of the dead-end pores). With the knowledge of the open porosity (measured with non-acoustic methods), and the measurement of kinematic...