Hydroxyapatite/alpha-alumina composites were prepared by means of high-energy vibratory ball milling. The effect of the addition of alumina, from 5 to 25 wt%, was investigated. x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) results indicated thathydroxyapatite andaluminawere themajorphases aftermechanicalmilling and only small peak shifts were observed. Transmission...

The aim of this study was to evaluate the bone regeneration of hydroxyapatite (HA)/alumina bilayered scaffold with a 3 mm passage-like medullary canal in a beagle tibia model. A porous HA/alumina scaffold was fabricated using a polymeric template-coating technique. HA/alumina scaffold dimensions were 10 mm in outer diameter, 20 mm in length, and with either a 3 mm passage or no passage. A 20 mm...

The enhanced degradation of organophosphorous-based chemical warfare agents (CWAs) on metal-oxide surfaces holds immense promise for neutralization efforts; however, the underlying mechanisms in this process remain poorly understood. We utilize large-scale quantum calculations first time to probe high-temperature diisopropyl methylphosphonate (DIMP), a nerve agent simulant. Our Born-Oppenheimer...

The mono-metallic and bi-metallic catalysts have been prepared by impregnating with solutions containing a compound of H2PtCl6,WO3 and 1ml HCl (0.1 mol). It should be noted that the catalysts’ activity and selectivity have been determined under these conditions : 450-5000C ,and 15-25atm by H2. For converting n-heptane , the molar ratio H2/C7H16 is 5 , and LHSV is 1.5ml/h. It has been proved tha...

Increasing uses of engineered nanoparticles (ENPs) in commercial products and industrial applications has eventually resulted to their releases into atmospheric, terrestrial, and aquatic environments. However, knowledge gaps in ENPs toxicity, fate, and behaviour currently limit our ability to quantify risk assessment of materials with nanoscale dimensions, and therefore, the extent of the resul...

THE following comments are directed to the sections (2) ‘‘revisit to the grain growth problems in alumina’’ and (3) grain growth without a liquid phase in the article of concern. The purpose of this comment is to challenge the authors’ assertions and refute the following arguments, namely, first that ‘‘MgO can be considered a very effective grain growth promoter in the sintering of alumina,’’ s...

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...

The synthesis and analysis of inorganic material combinatorial libraries by a directed-sorting, split-pool bead method was demonstrated. Directed-sorting, split-pool, metal-loaded libraries were synthesized by adsorbing metal salts (H2PtCl6, SnCl2, CuCl2, and NiCl2) and metal standards (Pt, Cu, Ni in HCl) onto 2-mg porous gamma-alumina beads in 96- or 384-well plates. A matrix algorithm for the...

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...