The dispersion and coordination of aluminium species on the surface of silica-alumina based materials are essential for controlling their catalytic activity and selectivity. Al and Al are two common coordinations of Al species in the silica network and alumina phase, respectively. Al is rare in nature and was found hitherto only in the alumina phase or interfaces containing alumina, a behavior ...

BACKGROUND AND PURPOSE Excessive wear of acetabular liners in hip replacements may lead to osteolysis and cup loosening. Different head materials are currently used. We measured differences in wear between alumina and cobalt-chrome heads with the same polyethylene liner. PATIENTS AND METHODS 39 patients (43 hips) with osteoarthritis were included in a study with 10-year follow-up. Wear was me...

Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/AlS.G.) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel m...

Oxide-supported amine materials are widely known to be effective CO2 sorbents under simulated flue-gas and direct-air-capture conditions. Most work has focused on amine species loaded onto porous silica supports, though potential stability advantages may be offered through the use of porous alumina supports. Unlike silica materials, which are comparably inert, porous alumina materials can be tu...

We previously reported the five-to-six-year results of the use of third-generation alumina-on-alumina bearings in a consecutive series of 100 primary cementless total hip arthroplasties. This report presents the longer-term outcomes of these same bearings, at a minimum of ten years postoperatively. Eighty-six of eighty-eight hips available for the study retained the original bearings at the tim...

In an Al2O3-TiO2 mixed oxide system, the incorporation of TiO2 to alumina is known to increase the acidity of the resulting mixed oxide; depending strongly on the preparation method and the titania concentration. When using TiO2 as a support of NiMo catalysts, initial catalytic activity in hydrodesulfurization reactions is much higher than that on catalysts based on pure alumina. One of the mai...

This second paper in a series describes the relationship between grain growth kinetics and grain boundary complexions in silicadoped alumina. Dense high-purity silica-doped alumina samples were annealed for various times in the temperature range of 13001 and 19001C and their grain growth behavior was quantified. Four different grain boundary complexions were observed in silica-doped alumina, al...

In this paper, the influence of the atomic layer deposited alumina (Al2O3) thin films on the dynamics of a high-Q mechanical silicon oscillator was experimentally studied. The resonance frequency and Q value of uncoated oscillators used in this work were about f0 = 27 kHz and Q = 100 000 at p < 10−2 mbar and T = 300 K. Deposited alumina film thicknesses varied from 5 to 662 nm. It is demonstrat...