In order to elucidate the effect of sodium on the activity of ZSM-5 supported metal oxides catalysts (ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5) for the transesterification of soybean oil with methanol, ZSM-5 supported metal oxides were prepared with and without sodium hydroxide by impregnation. The metal compositions of the ZSM-5 supported metal oxide catalysts and the metal concentrations dissolved...

We report a detailed investigation of the structural and chemical characteristics of thin evaporated Al2O3 tunnel barriers of variable thickness grown onto single-layer graphene sheets. Advanced electron microscopy and spectrum-imaging techniques were used to investigate the Co/Al2O3/graphene/SiO2 interfaces. Direct observation of pinhole contacts was achieved using FIB cross-sectional lamellas...

Based on density functional methods, we investigate the origin of variations in electronic structures and dielectric constants of representative alumina polymorphs. We consider the most stable -Al2O3 and three metastable phases of alumina, , , and -Al2O3. Computed energy gaps are found to be in the order of , which can be understood based on electrostatic potentials at specific lattice sites; w...

Increasing the thermal conductivity of PDMS (polydimethylsiloxane) based microfluidics is an important issue for the thermal management of hot spots produced by embedding electronic circuits in such systems. This paper presents a solution for enhancing the thermal conductivity of such PDMS based microfluidics by introducing thermally conductive alumina (Al2O3) nanoparticles, forming PDMS/Al2O3 ...

The utilization of the anodic TiO2 nanotube layers, with uniform Al2O3 coatings of different thicknesses (prepared by atomic layer deposition, ALD), as the new electrode material for lithium-ion batteries (LIBs), is reported herein. Electrodes with very thin Al2O3 coatings (∼1 nm) show a superior electrochemical performance for use in LIBs compared to that of the uncoated TiO2 nanotube layers. ...

The effect of submicron-sized Al2O3 particle addition on the crystal structure and superconducting properties of YBa2Cu3O7-δ ceramics was systematically studied. Series of YBa2Cu3O7−δ + x Al2O3 samples (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5,0.6 wt.% ) were prepared using the solid state reaction method. The lattice parameters and the orthorhombicity were decreased slightly with Al2O3 addition. No ch...

In this paper, an experimental work was investigated on nanorefrigerant .Nano Al2O3-PAG oil was used as nano-refrigerant in R134a vapour compression refrigeration system . An experimental setup was designed and fabricated in the lab. The system performance was investigated using energy consumption test and freeze capacity test. The results indicate that Al2O3 nano refrigerant works normally and...

AlN thin films have been grown on R((1-12) surface-cut)-Al2O3, SiO2-glass and C((001) surface-cut)-Al2O3 substrates, by using a reactive-RF-sputter-deposition method. X-ray diffraction (XRD) shows that AlN film has (110) orientation of wurtzite crystal structure for R-Al2O3 and (001) orientation for SiO2-glass and C-Al2O3 substrates. The film thickness was analyzed by Rutherford backscattering ...

Wettability and interface microstructure were studied for Nb-containing melts in the contact with ceramic oxide materials of Al2O3-SiO2 system. Ni-40.5 at.%Nb and Au-(0-20) at.%Nb alloys were investigated as prospective alloys for high temperature brazes. Ceramic samples ranged in composition from pure Al2O3 to pure SiO2. The wettability was measured by the sessile drop method. Microstructure o...

The improvement of the metal/InGaAs interface is essential for the future application of InGaAs metal source/drain Schottky-barrier metal-oxide-semiconductor field-effect-transistors. In this article, on In0.53Ga0.47As, the authors examine the recently proposed method of inserting an ultrathin insulator to modulate the effective Schottky-barrier height SBH at the metal/semiconductor interface. ...