The transport of pure gases through a microporous membrane is described. The alumina-based membrane (pores 2.5-4 nm) is suitable for Knudsen diffusion separation . To improve the separation factor, interaction with and mobility on the pore wall of one of the gases of a mixture is necessary. To introduce surface diffusion of oxygen and hydrogen, a y-alumina membrane was impregnated with silver ....

The apparent diffusion coefficients of tris(2,2'-bipyridyl)ruthenium ([Ru(bpy(3))](2+)) are estimated in silica-nanochannels which are assembled inside columnar alumina pores in an anodic alumina membrane, and are modified with alkylsilanes such as trimethylchlorosilane (C1), butyldimethylchlorosilane (C4), and dodecyldimethylchlorosilane (C12). The estimation is performed by observing the lag-...

The Three Dimensional Printing (3DP) Process hasbe~nadapted for processing of fine ceramic powders to •• prepare structllraLceramic components. Our preliminary study was designed to reveal those aspects ofthe.3DPprocesswhichmust be modified for use with fine ceramic powders. The basic elements of the modified process are to spread submicron alumina powder and printJatex binder. Several methods ...

Nanoporous alumina membranes exhibit high pore densities, well-controlled and uniform pore sizes, as well as straight pores. Owing to these unusual properties, nanoporous alumina membranes are currently being considered for use in implantable sensor membranes and water purification membranes. Atomic layer deposition is a thin-film growth process that may be used to modify the pore size in a nan...

Monolithic ceramics have been fabricated from coated green fibers to create fibrous microstructures. The fibrous monoliths consist of high aspect ratio polycrystalline regions (cells) of a primary phase separated by thin secondphase regions (cell boundaries) designed to improve fracture resistance. The cells are the remnants of the green fiber which consists of ceramic powder and a polymer bind...

This article provides details of a study that investigates hydrogen (H2) separation, purification and transport behaviour ceramic ?-alumina membrane compares it with ?-alumina modified Boehmite sol.

A modified smoothed particle hydrodynamic (MSPH) computational technique was utilized to simulate molten particle motion and infiltration speed on multi-scale analysis levels. The radial velocity and velocity gradient of molten alumina, iron infiltration in the TiC product and solidification rate, were predicted during centrifugal self-propagating high-temperature synthesis (SHS) simulation, wh...

AIM This study includes a comparative evaluation of the various surface treatments of the intaglio surface of crowns in combination with various luting agents for maximal retention. MATERIALS AND METHODS Totally, 150 dies of a standard complete crown preparation were fabricated. Wax pattern with a loop on the occlusal surface was prepared on each die using standard procedures, and then crowns...

Egyptian Petroleum Research Institute, Nasr City, Cairo, Egypt. Chemistry department, Faculty of Science, Taif University, KSA. _________________________________________________________________________________________ Nine alumina samples of various modification techniques were subjected to thermal analysis via thermogravimetric analysis (TGA) and differential thermal analysis (DTA), in order t...

Transition alumina, with different La loadings, were synthesized from boehmite (AlOOH) hydrosols containing a PEO/PPO/PEO triblock copolymer (Pluronics P123) and lanthanum nitrate. After calcination at 500 °C, the xerogels prepared from these sols have large specific surface area ( 400 m/g) and very large porous volumes, increasing with the amount of La to reach 2.5 cm/g for La/(La + Al) = 0.03...