Solid particles dispersed in a liquid with sizes no larger than 100nm, known as nanofluids, are used to enhance Thermophysical properties compared to the base fluid. Preparations of alumina (Al2O3), titania (TiO2) and silica (SiO2) in water have been experimentally conducted in volume concentrations ranging between 1 and 2.5%. Thermal conductivity is measured by the hot wire method and viscosit...

Reverse flotation process was optimized by an experimental programme based on statistical analysis for reduction of silica and alumina levels from screw classifier overflow so as to enrich iron values. Flotation of alumina and silica bearing minerals with Sokem 521C and starch as collector and depressant respectively was studied to estimate their optimum levels at different particle sizes. A tw...

A simple donor-acceptor linked dyad, 9-mesityl-10-methylacridinium ion (Acr(+)-Mes) was incorporated into nanosized mesoporous silica-alumina to form a composite, which in acetonitrile is highly dispersed. In this medium, upon visible light irradiation, the formation of an extremely long-lived electron-transfer state (Acr(•)-Mes(•+)) was confirmed by EPR and laser flash photolysis spectroscopic...

The aim of this research is to develop a silica gel and alumina column chromatography for separation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) into two groups. This is achieved by optimizing the cut-off volume of eluting solvent and weight ratio of silica gel and alumina. In this process mixture of PAHs and PCBs divide in two groups and simultaneously o...

Self- and cross-metathesis of fatty acid methyl esters (FAMEs) was investigated using a silica alumina supported Re(2)O(7) catalyst. Although a 3 wt% Re(2)O(7)/SiO(2)-Al(2)O(3)/SnBu(4) is already active for the metathesis of unsaturated FAMEs, the results have shown that particle size of silica alumina support has a profound influence on its activity and selectivity. Consequently, high substrat...

In this study different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (KNO3 selected as phase change material) with nanoparticles using the direct synthesis method. The thermal properties of the nanofluids obtained were investigated. Following the improvement in the specific heat achieved, these nanofluids can be used in concentrating solar plants with ...

In the present study, the effect of alumina on the pore structure and hydrothermal stability of nanostructured silica was investigated. SiO2 and SiO2-15wt%Al2O3 membranes were prepared by dip coating on mesoporous γ-Al2O3 coated macroporous α-alumina support. The particle sizes of sol were increased by adding of alumina to silica...

Hierarchically structured membranes composed of mesoporous silica embedded inside the channels of anodic alumina (MS-AAM) were synthesized using the aspiration method. Ethanol is shown to have a significant effect on the type and organization of the mesoporous silica phase. Detailed textural analysis revealed that the pore size distribution of the mesoporous silica narrows and the degree of ord...

The apparent diffusion coefficients of tris(2,2'-bipyridyl)ruthenium ([Ru(bpy(3))](2+)) are estimated in silica-nanochannels which are assembled inside columnar alumina pores in an anodic alumina membrane, and are modified with alkylsilanes such as trimethylchlorosilane (C1), butyldimethylchlorosilane (C4), and dodecyldimethylchlorosilane (C12). The estimation is performed by observing the lag-...