Low temperature fabrication of Al2O3-polyimide composite substrates was carried out by an aerosol deposition process using a mixture of Al2O3 and polyimide starting powders. The microstructures and dielectric properties of the composite thick films in relation to their Al2O3 contents were characterized by X-ray diffraction analysis. As a result, the crystallite size of α-Al2O3 calculated from S...

Five monolithic catalysts with low noble metal content were prepared by immerge method (Pt/gamma-Al2O3, Pt/La-Al2O3, Pt/YSZ-Al2O3, Pt+Pd/La-Al2O3 and Pd/La-Al2O3) and their activity measurements were carried out in a conventional fixed-bed flow reactor. The results show that La-Al2O3 can promote activity of the prepared catalysts and can decrease the complete conversion temperature of cooking f...

Herein, laminar convective heat transfer from two horizontally arranged spheres has been evaluated by using numerical models inside water-based fluids incorporated with alumina (Al2O3), copper oxide (CuO), and (Cu) nanoparticles. The problem was simulated for different Rayleigh numbers ranging 103 to 106 various volume fractions including 2, 4, 6, 8%. evaluation process included the perspective...

By varying the ratio of the constituents, compound films can exhibit a widely tunable range of physical properties. Atomic layer deposition ~ALD! techniques are based on sequential, self-limiting surface reactions and can grow compound films. In this study, ZnO/Al2O3 alloy films were prepared using ALD techniques. By adjusting the ALD pulse sequence, the ZnO/Al2O3 alloy film composition was var...

in the present study, electrophoretic deposition (EPD) was used to obtain dense and crack-free layers of Al2O3 on carbon substrate. Microstructural study of the obtained layers by scanning electron (SEM) and optical microscopy (OM) approved that crack-free layers can be obtained by EPD technique. According to obtained results, isopropanol is a suitable media to obtian compact layers which is at...

rheological characteristics of al2o3, cuo and tio2 nano particles were investigated in oil asthe base fluid at 1 and 2 wt.%. constitutive relations for non-newtonian fluid were discussedbased on the power-law model. measured viscosities of each nanofluid were used to evaluatethe power-law and consistency index. results indicated that the nanofluid viscosity decreasedby increasing the concentrat...

Triboluminescence (TL) is an optical phenomenon that has a long and varied history with broad applications, such as damage detection, X-ray source, and mass health monitoring sensor. So far, the properties and mechanisms of TL remain not completely understood. The TL properties emitted during the sliding contact between Al2O3 and SiO2 surfaces were studied along different crystallographic orien...

A series of ceria nanocatalysts have been prepared to study the structure dependency of the CO oxidation reaction. The ceria samples with well-defined nanostructures (nanocubes/Ce-NC and nanorods/Ce-NR) have been prepared using the hydrothermal method. Mesoporous ceria (Ce-MES) and ceria synthesized with solution combustion technique (Ce-SCS) have also been prepared for comparison. The lowest C...

In this study, we aimed to figure out how the depolymerization of polyethylene terephthalate produces monomers, dimers, trimers, and other oligomers bis (2-hydroxyethyl) terephthalate. Polymerization was achieved in a bubble column reactor with 0.05 wt% 40–50 nm magnesium oxide nanoparticle as catalyst. A used perform recycling process at boiling point ethylene glycol atmospheric pressure. Depo...