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 ...

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...

The entropy generation based on the second law of thermodynamics is investigated for turbulent forced convection flow of ZrO2-water nanofluid through a square pipe with constant wall heat flux. Effects of different particle concentrations, inlet conditions and particle sizes on entropy generation of ZrO2-water nanofluid are studied. Contributions from frictional and thermal entropy generations ...

For next generation planar lightwave circuit (PLC) devices, high function and high-density integration are required as well as downsizing and cost reduction. To realize these needs, high refractive index difference between a core and a clad (∆) is required. To use PLC for practical applications, silica-based PLC is one of the most attractive candidate. However, degradation of the optical proper...

in this study the effect of nano meter size zro2 particles on the microstructure, densification and hydration resistance of magnesite –dolomite refractories was investigated. 0, 2, 4, 6 and 8 wt. % zro2 particles that were added to magnesite –dolomite refractories containing 35 wt. % cao. the hydration resistance was measured by change in the weight of specimens after 72 h at 25℃ and 95% relati...

The high-k dielectric TiO2/ZrO2 bilayer composite film was prepared on a Si substrate by radio frequency magnetron sputtering and post annealing in N2 at various temperatures in the range of 573 K to 973 K. Transmission electron microscopy observation revealed that the bilayer film fully mixed together and had good interfacial property at 773 K. Metal-oxide-semiconductor capacitors with high-k ...