This paper demonstrates that seeding nanocrystalline transition alumina powders is a viable option for producing high quality, alumina-based ceramics. By using a-Al2O3 concentrations of 51.25 wt.% a-Al2O3 seed particles (equivalent to 5 10 seeds/cm of g-Al2O3) the sintering temperature is reduced from 1600 C for unseeded g-Al2O3 to 1300–1400 C in dry pressed powders. The scale of the sinteredmi...

BACKGROUND The mechanical properties of alumina ceramic, now in its third generation, have been markedly improved through the evolution of design features and manufacturing processes and the introduction of proof-testing. Nonetheless, because of the lack of ductility of alumina ceramic, there is concern regarding the risk of fracture during insertion or in vivo use. The purpose of the present s...

We examined the role of silver and alumina in Ag–alumina catalysts for the selective catalytic reduction (SCR) of NOx by methane in gas streams containing excess oxygen. A cogelation technique was used to prepare Ag–alumina materials with high dispersion of silver even at high metal loadings (>10 wt%) and after air calcination at 650 ◦C. Typically, a part of silver is present as fine nanopartic...

The preparation and spectroscopic characterization of a CO-inhibited [FeFe] hydrogenase with a selectively (57)Fe-labeled binuclear subsite is described. The precursor [(57)Fe2(adt)(CN)2(CO)4](2-) was synthesized from the (57)Fe metal, S8, CO, (NEt4)CN, NH4Cl, and CH2O. (Et4N)2[(57)Fe2(adt)(CN)2(CO)4] was then used for the maturation of the [FeFe] hydrogenase HydA1 from Chlamydomonas reinhardti...

The purpose of the present work was to clarify the effects of parameters of porous ceramics on the characteristics of composites fabricated by high-pressure infiltration. Alumina with different porosity (15–70 vol%) and pore morphology was successfully fabricated by gelate-freezing and the partial-sintering, respectively. Alumina/aluminum composites were made by squeeze casting, the aluminum in...

1. Introduction Mesoporous materials with ordered arrays of uniform nanochannels of a controllable size have wide-ranging applications, one of which is membrane separation. In order to be used as a membrane for size-exclusive separation of molecules, it is necessary to synthesize a defect-free structure with continuous nanoporosity. Mesoporous silica and porous anodic alumina have been extensiv...

Typically, alumina nanowires (NWs) are synthesized via physical evaporation, templated anodized aluminum oxide (AAO), or the vapor-liquid-solid (VLS) process [1,2,3]. All of these techniques have been shown to demonstrate successful growth of alumina NWs; however, in the cases where a facile method resulting in vertically aligned NWs is desired, many of these methods are difficult to integrate ...

Between 1990 and 1992, we implanted 71 hybrid alumina-on-alumina hip arthroplasties in 62 consecutive patients under the age of 55 years, with a mean age of 46 years at surgery. There were 56 primary and 15 secondary procedures. The prostheses involved a cemented titanium alloy stem, a 32 mm alumina head, and a press-fit metal-backed socket with an alumina insert. Three patients (four hips) die...

The effect of length variation on the magnetic properties of NiFe alloy nanowires electrodeposited into the alumina template was investigated. The diameter (45±2.5 nm) and length (~ 1.9, 7.12, 8.3, 9.5 and 13.3 µm) of the nanowires were estimated from scanning electron microscopy images. Energy dispersive spectroscopy results showed Ni3Fe7 composition of the alloy nanowire...

This study evaluated the effect of alumina-blasting and three commercial adhesive primers on the shear bond strength of a dual-cured resin luting agent to zirconia ceramics. Two different-sized zirconia ceramic specimens were treated with or without alumina-blasting and then treated with one of three adhesive primers. Subsequently, specimens were cemented together with Linkmax HV (GC). Half of ...