The recent Spitzer detections of the 9.7μm Si–O silicate emission in type 1 AGNs provide support for the AGN unification scheme. The properties of the silicate dust are of key importance to understanding the physical, chemical and evolutionary properties of the obscuring dusty torus around AGNs. Compared to that of the Galactic interstellar medium (ISM), the 10μm silicate emission profile of ty...

Cerium doped lutetium silicate powders were prepared by solegel process with different cerium concentrations (0, 0.01 and 0.03 mol%). The synthesized lutetium silicate powders were investigated by X-ray diffraction (XRD), TG-DTA, SEM, and Photoluminescence excitation and emissions. The crystallization of lutetium silicate is observed at 1.073 C in S2 (and S3: 1.058 C) sample. The formation of l...

Simultaneous application of colloidal processing and liquidforming additives to alumina resulted in a sintered density of >99% in 1 h at a temperature as low as 1070°C for a commercial high-purity alumina powder at a total dopant level of 2 mol%. The additives were 0.9% CuO + 0.9% TiOz + 0.1% B 2 0 3 + 0.1% MgO. At higher temperatures or after prolonged sintering, the doped alumina ceramic deve...

A comparison has been made of the infrared spectra of alumina with molybdenum oxide alumina in both the oxidized and reduced forms. In the case of molybdena-alumina prepared via adsorption of gaseous MoOp(OH)t, the spectra show that a practically complete monolayer of Mo6+ oxide covers the alumina. After reduction with hydrogen the hydroxyls of the carrier appear. From the reversibility of redu...

Porous alumina film on aluminum with gel-like pore wall was prepared by a two-step anodization of aluminum, and the corresponding gel-like porous film was etched in diluted NaOH solution to produce alumina nanowires in the form of densely packed alignment. The resultant alumina nanowires were reacted with NH(3) and evaporated aluminum at an elevated temperature to be converted into densely pack...

The growth of ordered nanorods of mesoporous SBA-15 inside a porous alumina membrane has been achieved for the first time by a simple sol-gel method. The obtained SBA-15 nanorods themselves have ordered hexagonal mesochannels with a size of about 6 nm and have been arranged to form hexagonal arrays by the limitation of pores of the alumina membrane. The synthesized alumina membrane with mesopor...

concrete is one of the most utilized construction materials in the world. nowadays, nano silicate usage due to its special property attracted considerable attention. on this basis, studying its environmental functions is an essential issue. accordingly, the behavior of normal concrete and the one with nano silicate were compared via taking advantage of life cycle assessment (lca) method in this...

a simple method for fabrication of highly ordered gold nanorod film is introduced in this article. the procedure is based on thermal evaporation of gold into a porous anodic alumina film (paa). the ppa film was fabricated by combining the hard and mild anodization. this combination effectively decreases the processing time of fabrication of highly ordered porous anodic alumina film with control...