Magnetic powder of Sr-ferrite was prepared by conventional and sol-gel auto-combustion methods. In conventional method, strontium carbonate and ferric oxide powders were mixed together and then mixture was calcined. In sol-gel auto-combustion method, a solution containing strontium nitrate, ferric nitrate and citric acid was heated until the combustion took place automatically; then, as-burnt p...

In previous studies nano sized hydroxyapatite (HA) particles were prepared by solgel or precipitation methods, in which the products were washed by aqueous or non-aqueous liquids to remove impurities or undesired components. The washing is know to modify the surfaces of the cystalline particles. This study evaluated properties of nano HA materials prepared by a spray drying method in which the ...

We report the results of an experimental study to determine influence pressure on diffusion creep in wet olivine. In order observe at high-pressure conditions laboratory strain rates, we prepared ultra-fine grained (0.22–0.72 μm) olivine aggregates both from San Carlos and oxide mixtures using a solgel technique. All samples contain some water (~1000 ppm wt) presumably due adsorption fine-grain...

Electrorheological (ER) properties under oscillatory shear of perchloric acid doped-poly(3-thiopheneacetic acid)/oil (P3TAA/silicone) suspensions have been investigated. The effects of electric field strength, silicone oil viscosity, and particle concentration were investigated. When the electric field strength reaches a critical value, the P3TAA-based ER fluid exhibits transitional behavior be...

High quality manganese oxide thin films with smooth surfaces and even thicknesses have been prepared with a nonaqueous sol-gel process involving reduction of tetraethylammonium permanganate in methanol. Spin-coated films have been cast onto soft glass, quartz, and Ni foil substrates, with two coats being applied for optimum crystallization. The addition of alkali metal cations as dopants result...

Copper (Cu) ions are of interest with respect to materials for bone regeneration because of their pro-angiogenic potential. One of the problems with synthetic bone scaffolds is the fast decrease in viability of cells with increasing distance from the surface of the scaffold material, which results from the inability of nutrients and oxygen to diffuse further than 150-200 μm from the surface wit...

in the analysis of spatial point patterns, complete spatial randomness (csr) hypothesis,which is a restriction of a homogenous poisson process to study region a, operates as a dividinghypothesis between “regular” and “aggregated” patterns. meanwhile, many alternatives to csr inaggregated patterns are extensions of homogenous poisson processes themselves. therefore, when thecsr hypothesis is rej...

We demonstrate that isophthalic acid-ended telechelic poly(1,5-cyclooctadiene)s (APCODs) form thermo-reversible gels in non-polar solvent with a unique molecular mechanism for their thermo-reversibility. Like other associative telechelic polymers, A-PCODs form “flower-like” micelles at low concentration and form gels through bridging at higher concentration which exhibit linear viscoelasticity....

The aldol condensation of model compounds furfural and acetone on the selected base catalysts have been performed. The activity of MgO was compared with industrially produced hydrotalcite and the series laboratory prepared hydrotalcites. Si×MAl2O4 hydrotalcites (M = Mg, Zn, Ni, Co, Cu, and Fe) were prepared by the solgel method at low calcination temperature of 300°C. The properties of the cata...