in this research different types of al2o3 were used as supports to prepare catalysts for dehydrogenation of isobutane to isobutene. these supports were al2o3 from merck, axen and gamma al2o3 synthesized from al(oh)3. sn/pt/al2o3 catalysts were prepared by sequential impregnation, at first pt and then sn was deposited. characterization of catalysts was performed by x-ray powder diffraction (xrd)...

In the Kv2.1 potassium channel, binding of K(+) to a high-affinity site associated with the selectivity filter modulates channel sensitivity to external TEA. In channels carrying Na(+) current, K(+) interacts with the TEA modulation site at concentrations </=30 microM. In this paper, we further characterized the TEA modulation site and examined how varying K(+) occupancy of the pore influenced ...

Alkali metal K- and/or Na-promoted FeCoCuAl catalysts were synthesized by precipitation and impregnation, their physicochemical catalytic performance for CO2 hydrogenation to light hydrocarbons was also investigated in the present work. The results indicate that Na K introduction leads formation of active phase metallic Fe Fe-Co crystals order &lt; K-Na. simultaneous causes a synergistic effect...

layer sites of high charge phyllosilicates such as micas is not readily exchanged by other cations and is usually Physical and chemical weathering processes in the rhizosphere may considered ‘fixed’ (Comans et al., 1991). lead to the generation of a greater density of Cs-selective frayed edge sites (FES) on rhizosphere soil as compared with bulk soil. This study The strongest association betwee...

A multilayer composite ceramic membrane was prepared by depositing a nano-scale layer of SiO2 on top of a modified porous alumina support by chemical vapor deposition (CVD) method. The modification of the support was carried out by adding a graded layer of Al2O3 (γ-alumina phase), using sol-gel method. An optimized temperature of 700 K for intermediate layer calcination was gained by XRD analys...

a carbon ionic liquid electrode (cile) modified with tio2-fe nanoparticles was constructed by incorporating tio2-fe nanoparticles into the paste matrix. under the optimized experimental conditions, using differential pulse voltammetry (dpv), the oxidation of thiocyanate and oxalate were occurred at potentials of 0.740 v and 1.010 v, respectively, at the surface of the modified electrode. observi...