We report on the lowest temperature of SWCNT growth using endothermic decomposition of CH4 gas on a specially activated alumina-supported Fe:Mo catalyst. However, the observed lowest growth temperature (560 degrees C) is higher than that reported previously for exothermic feedstock type. Our observation indicates that the decomposition threshold temperature of the feedstock limits the SWCNT gro...

Alumina is an inorganic material, which is widely used in ceramics, catalysts, catalyst supports, ion exchange and other fields. The micromorphology of alumina determines its application in high tech and value-added industry and its development prospects. This paper gives an overview of the liquid phase synthetic method of alumina preparation, combined with the mechanism of its action. The pres...

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 objective of this work was to produce and characterize activated carbon from sugarcane bagasse agglomerated with Alumina (Al2O3) apply it in treatment vinasse pretreated by coagulation-flocculation reduce the toxics parameters vinasse. adsorbent characterized textural analysis, XRD, pHZPC, SEM EDS. Adsorption isotherms, adsorption kinetics thermodynamic process were obtained. Langmuir isoth...

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...