PURPOSE The purpose of this study was to investigate the possible radioactive potential of zirconium dioxide (ZrO2) dental ceramics. Such information is necessary since they became an integral part of routine prosthetic rehabilitations and devoid of scientific information about their radioactivity creates some concern in the dental community. METHODS Four different types of commercial ZrO2 ce...

Bleaching of Congo red catalyzed by ZrO2 nanoparticles was study under UV and sunlight irradiations. The nanoparticles of ZrO2 have been synthesized by controlled precipitation method. The concentration of ZrOCl2 and ammonia reactants and the calcinations temperature of ZrO2 were optimized for the control of nanoparticles size. Characterization of the prepared nanoparticles was studied by using...

The initial stages of growth of zirconia nanoparticles deposited on SiO2, Y2O3, and CeO2 substrates have been studied by the x-ray photoelectron spectroscopy peak shape analysis. ZrO2 was deposited by plasma decomposition of a volatile Zr OtBu 4 precursor. The electronic interactions at each particular interface formed have been followed by means of the modified Auger parameter of the deposited...

A quasi-analytic model has been developed to examine energy conversion during the microwave sintering of a ceramic that is surrounded by a susceptor. Low-loss ceramics, such as ZrO2, couple poorly with microwave radiation at low temperatures; however, because the dielectric loss usually increases rapidly as temperature increases, coupling improves dramatically at high temperatures. To improve h...

Highly transparent and homogeneous hybrids containing a single nano-sized inorganic oxide domain were synthesized from poly(methyl methacrylate) (PMMA) and aqueous dispersed zirconium oxide nanocrystals (ZrO2-NCs) in the presence of a coupling agent, 3-(methacryloxy)propyl-trimethoxysilane (MPTS), which was grafted onto the surface of ZrO2-NCs by zirconium hydroxide (Zr-OH) surface groups. The ...

The catalytic performance of Fe-Cr/ZrO2 catalysts, prepared by two different methodsscoprecipitation and coprecipitation-impregnation were examined in oxidative dehydrogenation of ethane to ethylene using CO2 as an oxidant. Thermogravimetric analysis and physicochemical characterization such as XPS, XRD, and BET were performed to explore the correlation of catalytic performance with physicochem...

Oxygen storage/release (OSC) capacity is an important feature common to all three-way catalysts that enables them to efficiently remove harmful compounds such as hydrocarbons, CO and NOx in automotive exhaust gases. In this report, three types of CeO2-ZrO2 (Ce:Zr = 1:1 molar ratio) compounds with different OSC were characterized by means of XRD (X-ray diffraction) and XAFS (X-ray absorption fin...

The emission control of NOx in exhaust gases is one of the greatest engineering challenges to extend the practical and commercial application of diesel and lean burn engines. One solution is selective NOx reduction using hydrocarbons in an oxidizing atmosphere. We mainly focused on catalytic reactions under temperature excursion because of the resemblance to conditions prevailing in real automo...

The presence of biogenic or process-derived impurities poses a major problem on the efficient catalytic hydrogenation of biomass-derived levulinic acid to γ-valerolactone; hence, studies on their influence on catalyst stability are now required. Herein, the influence of sulfuric acid as feed impurity on the performance of Ru-based heterogeneous catalysts, including Ru/ZrO2 and mono- and bimetal...

Nanocrystalline ZrO2 (Zirconia) has been synthesized by a conventional precipitation method. The structural, morphological, microstructural, optical and gas-sensing properties of ZrO2 were investigated by using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectroscopy and static gas sensing unit, respectively. X-ray diffrac...