in this paper, overall heat transfer coefficient and friction factor of water based γ-al2o3 nanofluid in a double tube counter flow heat exchanger have been measured experimentally under turbulent flow condition. for better dispersion of γ-al2o3 nanoparticles in distilled water, magnetic stirrer and ultrasonic vibrator (with a power of 240 kw and frequency of 35 khz) were implemented. the stabi...

The goal of this paper is to experimentally study the behavior of nanofluid to improve the performance of a circular heat pipe. Pure water and Al2O3-water based nanofluid are used as working fluids. An experimental setup is designed and constructed to study the heat pipe performance under different operating conditions. The effect of filling ratio, volume fraction of nano-particle in the base f...

alumina-supported cs3[re(c2o4)3] precursor has been synthesized  for preparation of re-cs/g-al2o3 catalyst. cs3[re(c2o4)3]  has been prepared from the reaction of recl3 with  h2c2o4.2h2o and cscl in water. the complex has been characterized by elemental analysis and various spectroscopy techniques such as ft-ir, uv-vis and 13c-nmr. the complex was supported on γ-al2o3 by column chromatography. ...

Biodiesel which were synthesis from transesterification reaction in the present of heterogeneous base catalyst has been intensively studied over the last decades. This catalyst has an excellent result in producing high percentage conversions of biodiesel without further purification and cleaning process which contribute to the water pollution and high water content in biodiesel product. So, thi...

Abstract: Composite specimens were prepared by dispersion of various amounts of nano-sized Al2O3 fillers in a monomer system containing 60% Bis-GMA and 40% TEGDMA. For comparative purposes, composite samples containing micrometer size Al2O3 fillers were also prepared following the same procedure. The mechanical properties of the light- cured samples were assessed by three-point flexural strengt...

The paper reports a process for synthesis of γ-alumina from kaolin. Kaolin was transformed to meta-kaolin by calcination at 800 ̊C for 2h. γ-alumina powder was synthesized through extracting alumina from metakaolin via H2SO4 and meta-kaolin reactions and consequently precipitation in ethanol, which led to form the aluminum sulfate. The precipitated aluminum sulfate was dried and calcined at 900 ̊...

We have demonstrated the synthesis of γ-Fe2O3 nano-particles through a facile and novel calcination process in the air. There is no pH regulation, gas atmosphere, additive, centrifugation or other complicated procedures during the preparing process. A detailed formation process of the nano-particles is proposed, and DMF as a polar solvent may slower the reaction process of calcination. The stru...

Improved resistive switching memory characteristics by controlling the formation polarity in an IrOx/Al2O3/IrOx-ND/Al2O3/WOx/W structure have been investigated. High density of 1 × 1013/cm2 and small size of 1.3 nm in diameter of the IrOx nano-dots (NDs) have been observed by high-resolution transmission electron microscopy. The IrOx-NDs, Al2O3, and WOx layers are confirmed by X-ray photo-elect...

Investigation was to study the influence of pulse-impact on microstructure of Liquid-Phase-Pulse-Impact Diffusion Welding (LPPIDW) welded joints of aluminum matrix composite SiCp/A356, SiCp/6061Al, Al2O3p/6061Al. Results showed that under the effect of pulse-impact: 1) the interface state between reinforcement particle (SiC, Al2O3) and matrix was prominently; 2) the initial pernicious contact-s...