Zirconium oxide and tantalum oxide films were deposited in an inverted cylindrical magnetron cathode using high power pulsed sputtering. Average power densities were between 5 and 7 W/cm2 and peak power densities were in the range of 0.5 kW/cm2. In all of the experiments the oxygen was introduced using flow control, and the current and voltage waveforms of the HPPMS supply changed in a reproduc...

PURPOSE The purpose of this study was to assess the surface characteristics and the biocompatibility of zirconium (Zr) coating on Ti-6Al-4V alloy surface by radio frequency (RF) magnetron sputtering method. MATERIALS AND METHODS The zirconium films were developed on Ti-6Al-4V discs using RF magnetron sputtering method. Surface profile, surface composition, surface roughness and surface energy...

PURPOSE This paper is focused on the works concerning preparation of zirconium oxide ceramic blocks recommended for CAD/CAM systems used in prosthetic dentistry for manufacturing fixed prosthetic restorations. METHODS Zirconium-yttrium-magnesium mixed ceramic oxides were prepared by sol-gel method via hydrolysis and condensation of zirconium alkoxide precursor (zirconium (IV) propoxide) with ...

ZrO2·nH2O (hydrogel) impregnated with transition metals (Cu, Co, and Ni) was studied in this work as a precursor for the synthesis of CuO/ZrO2 (CuZ), CoOx/ZrO2 (CoZ), and NiO/ZrO2 (NiZ) catalysts, employed in the naphthalene oxidation reaction. Fresh and catalytically used materials were characterized by different physicochemical techniques, to compare the bulk and surface behavior, with partic...

BACKGROUND An increasing demand for esthetic restorations has resulted in an increased use of all-ceramic restorations, such as zirconium. However, one of the challenges the orthodontist must be willing to face is how to increase bond strength between the brackets and various ceramic restorations.Bond strength can beaffected bybracket type, by the material that bracketsaremade of, and their bas...

Cobalt is a nutrient to phytoplankton, but knowledge about its biogeochemical cycling is limited, especially in the Pacific Ocean. Here, we report sections of dissolved cobalt and labile dissolved cobalt from the US GEOTRACES GP16 transect in the South Pacific. The cobalt distribution is closely tied to the extent and intensity of the oxygen minimum zone in the eastern South Pacific with highes...

DENSE PERIODICAL PATTERNS IN PHOTONIC DEVICES:TECHNOLOGY FOR FABRICATION AND DEVICE PERFORMANCEbySABARISH CHANDRAMOHANDecember 2016 Advisor: Dr. Ivan AvrutskyMajor: Electrical EngineeringDegree: Doctor of Philosophy For the fabrication, focused ion beam parameters are investigated to successfullyfabricate dense periodical patterns, such as gratings, on hard transitio...

Four aluminas were used as supports for impregnation with a zirconium oxide with the aim to achieve a coating, without phase separation, between support and modifier. The supports were impregnated with different concentrations of zirconium aqueous resin, obtained through the polymeric precursor method. After impregnation the samples were calcined and then characterized by XRD, which led to iden...

G . H evesy has written that [6] 1 " In view of the I.great similarity b etween hafnium and zirconium, i t ris hardly possible to separate these two elements in a lsingle operation ." A simple one-step separation c adequ a te for analytical work has still to be developed for hafnium-ziTconium mixtures, although recent work employing ion exchange has developed suitable methods for the separation...