In this study, an industrial polycrystalline SiC tile was successfully sintered by pressureless sintering at 2150°C for 1 hour. The physical and mechanical properties of silicon carbide including density, hardness, bending strength, and fracture toughness were evaluated. The results indicated that the mentioned properties were 3.08 g.cm-3, 2503 HV0, 249.3 MPa, and 1.23 MPam0.5</...

The conductance of atomic scale filaments with three and seven Cu atoms in a-alumina are calculated using ab initio density functional theory. We find that the filament with 3 Cu atoms is sufficient to increase the conductance of 1.3 nm thick alumina film by more than 10 times in linear response. As the applied voltage increases, the current quickly saturates and differential resistance becomes...

We study the effects of insulating oxides in their crystalline forms on the energy band structure of monolayer and bilayer graphene using a first principles density functional theory based electronic structure method and a local density approximation. We consider the dielectric oxides SiO(2) (α-quartz) and Al(2)O(3) (alumina or α-sapphire), each with two surface terminations. Our study suggests...

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 adsorption of molybdenum hexacarbonyl on thin dehydroxylated alumina films grown on an Mo(100) single-crystal substrate is studied in ultrahigh vacuum using primarily temperature-programmed desorption and reflection-absorption infrared spectroscopy. Subcarbonyls are detected using infrared spectroscopy at low temperatures and desorb at 245K. A portion of the subcarbonyls decomposes to form ...

background: vascular calcification is an important stage in atherosclerosis. during this stage, vascular smooth muscle cells (vsmc) synthesize many osteogenic factors such as osteonectin (encoded by sparc). oxidative stress plays a critical role in atherosclerosis progression, and its accumulation in the vascular wall stimulates the development of atherosclerosis and vascular calcification. the...

background: oxidative modification of low-density lipoprotein (ldl) appears to be an early step in the pathogenesis of atherosclerosis. meanwhile, myeloperoxidase (mpo)-catalyzed reaction is one of the potent pathway for ldl oxidation in vivo. the aim of this study was to evaluate in vitro antioxidant effects of vitamins c and e on ldl oxidation mediated by mpo. methods: mpo was isolated from f...

this article reports a study of the thermo-oxidation and biodegradation in the soil of low-density polyethylene/starch films (ldpe/starch) by infrared spectroscopy: films of ldpe/starch blends of different composition (starch content range from 0 to 15% w/w),were prepared and exposed to thermo-oxidation at different temperatures at 80, 90 and 100°c,and buried in the soil of public dump during 3...

Alumina phase loaded with ammonium pyrrolidine dithiocarbamate (APDC )were synthesized based on chemical binding and physical adsorption approaches. The stability of a chemically modified APDC especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of alumina immobilized APDC phase. The application of this alumina for sorpti...