INTRODUCTION Incorporating a feldspar chemical bond between alumina filler particles is expected to increase the wear-resistant and flexural strength properties. AIMS AND OBJECTIVES An investigation was carried out to evaluate the influence of the feldspar chemical bonding between alumina filler particles on wear and flexural strength of experimental alumina/feldspar dental composites. It was...

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 interaction of chromium oxide with Alz03, TiOz and SiO? supports is investigated with Raman spectroscopy. The influence of the nature of the oxide support, calcination temperature and chromium oxide loading upon the molecular state of the supported chromium oxide is determined. The Raman studies reveal that the oxide supports stabilize the chromium oxide as Cr(V1) in tetrahedral coordinatio...

The feasibility of gas phase deposition using a Ti alkoxide precursor for precise surface modification catalysts was demonstrated by modifying mesoporous alumina support with oxide overcoat.

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...

A general, quantitative relationship between the photon-transport mean free path l* and resin sensitivity DP in multiple-scattering alumina/monomer suspensions formulated for ceramic stereolithography is presented and experimentally demonstrated. A Mie-theory-based computational method with structure factor contributions to determine l* was developed. Planar-source diffuse transmittance experim...

In this work the development of gold catalysts, essentially based on γ-alumina with small superficial fraction of Ce-Fe mixed oxides as support for the low temperature CO oxidation is proposed. Characterization results obtained by means of TEM, OSC, XPS, UV-Vis spectroscopy and H2-TPR are employed to correlate the activity data with the catalysts composition. The bare γ-alumina supported gold c...

1. Introduction A major field of ongoing study in gas mixture separation technology involves the development of novel composite ceramic membranes suitable for use across a broad range of process conditions. A common theme in these studies is the use of mesoporous/microporous support materials (e.g. α-alumina/γ-alumina, Vycor etc) with a minimum pore size of approximately 5 nm, in some cases sup...