In this study a bioinspired approach to induce self-mineralization of bone-like material on alumina surfaces is presented. The mineralizing enzyme alkaline phosphatase (ALP) is covalently immobilized by a carbodiimide-mediated chemoligation method. The enzymatic activity of immobilized ALP and its mineralization capability are investigated under acellular conditions as well as in the presence o...

A novel process of fabricating various oxide nanostructures on glass substrates is described. Transparent porous alumina films ( 6–150 nm) were first formed in acid solutions by anodization of aluminum layers sputter-deposited on a glass plate coated with a tin-doped indium oxide film. The porous alumina structures after pore-widened were then used as a host or a template in a sol–gel process t...

Zirconia–alumina composites couple the high toughness of zirconia with peculiar properties alumina, i.e., hardness, wear, and chemical resistance, so they are considered promising materials for orthopedic dental implants. The design performance needs to consider different aspects, such as type amount stabilizer sintering process, that affect mechanics toughening and, hence, mechanical propertie...

Stainless steel particles (60 μm in mean diameter) cladded with an alumina shell (2 μm thick and manufactured by mechanofusion) were sprayed with an Ar-H2 (53-7 slm) d.c. plasma jet (I = 500 A, P = 28 kW, th = 56 %). Two main types of particles were collected in flight, as close as 50 mm downstream of the nozzle exit: particles with a steel core with pieces of alumina unevenly distributed at t...

Silica nanoparticles (NPs) belong to the industrially most important NP types. In a previous study it was shown that amorphous SiO(2) NPs of 12.5 and 27.0 nm are stable in algal growth inhibition assays and that their ecotoxic effects are related to NP surface area. Here, it was hypothesized and demonstrated that an alumina coating completely alters the particle-particle, particle-test medium a...

In this study, we examined the fine structure of the compound eyes of a household fly and precisely replicated its entire structure using a low-temperature atomic layer deposition technique. The surface of the fly eye is found to be covered by highly packed protuberances, which potentially increases visual efficiency through increased photon capture for a given stimulus. The alumina replica was...

We compared and quantified the modes of failure and patterns of wear of 11 Mittelmeier and 11 Ceraver-Ostal retrieved alumina-alumina hip prostheses with reference to the corresponding clinical and radiological histories. Macroscopic wear was assessed using a three-dimensional co-ordinate measuring machine. Talysurf contacting profilometry was used to measure surface roughness on a microscopic ...

the aim of this research is to develop a silica gel and alumina column chromatography for separation of polycyclic aromatic hydrocarbons (pahs) and polychlorinated biphenyls (pcbs) into two groups. this is achieved by optimizing the cut-off volume of eluting solvent and weight ratio of silica gel and alumina. in this process mixture of pahs and pcbs divide in two groups and simultaneously other...

The fatigue properties of ultrathin protective coatings on silicon thin films were investigated. The cohesive and delamination fatigue properties of 22 nm-thick atomic-layered-deposited (ALD) titania were characterized and compared to that of 25 nm-thick alumina. Both coatings were deposited at 200 °C. The fatigue rates are comparable at 30 °C, 50% relative humidity (RH) while they are one orde...

Porous alumina was fabricated and optically characterized over a wide spectral range. Layers were formed electrochemically in oxalic acid solution from 10-mm-thick aluminum films evaporated onto silicon wafers. The layer formation was monitored with in situ spectroscopic ellipsometry in the visible and near-infrared wavelength range to accurately determine the thickness and dielectric functions...