Ab initio electronic-structure calculations of surface catalysis often give changes P0.1 eV for activation energies of intermediate steps when the surface structure or composition is varied, yet P50-fold change in activity according to naive interpretation of the Arrhenius formula is usually not seen in corresponding experiments. To quantitatively analyze this sensitivity inconsistency between ...

Nano-sized ZnO was synthesized through the hydroxide precipitation using drop wise method. The variations in resistance of sensing pellet at different temperatures were recorded. The relative resistance was decreased linearly with increasing temperatures over the range, 150°C-260°C. The activation energy of ZnO calculated from Arrhenius plot was found 0.007eV. Temperature response in terms of t...

Rise-time distribution spectra of a polycrystalline chemical vapor deposited diamond detector were directly measured from alpha-particle induced pulse shapes over a temperature range of 240–280 K. Pulses due to hole-dominated charge transport showed a strong delayed component due to thermal detrapping of charge from a shallow level, with a mean rise time that decreased strongly with increasing ...

The kinetics of protochlorophyllide phototransformation and of the subsequent blue shift were studied in homogenates prepared from etiolated wheat leaves using fluorescence spectroscopy at high pressures. The pressure dependence of the processes was studied between 0.1 and 400 MPa. The activation volumes were calculated from the pressure dependence of the kinetical curves of the processes and w...

Abstract We showed that the ferromagnetic correlation extended far into what was thought to be paramagnetic phase for pristine Ca 3 Co 2 O 6 in our Bi-substituted compound and found a between magnetic dielectric anomaly this region. have observed enhancement of property (dielectric constant 200 with loss factor 0.01 at 1 MHz), which is attributed high ionic polarizability Bi. The response curve...

This paper addresses the annealing temperature effect on nanostructure and phase transition of copper oxide thin films, deposited by PVD method on glass substrate (at 110 nm thickness) and post annealed at different temperatures (200-400°C) with a flow of 1 cm3s-1 Oxygen. The X-ray diffraction (XRD) was employed for crystallographic and phase analyses, while atomic force m...

The present work describes, the reaction between disodium salt of 1,3-dihydroxybenzene (in situ formation) and propargyl bromide was carried out in a solid-liquid biphasic phase transfer catalytic system at 50°C. Higher selectivity of the bis-derivative (1,3-bis(prop-2-ynyloxy)benzene) was obtained under solid-liquid PTC condion. The conversion of propargyl bromide of more than 99% was achieved...

A steady-state kinetic analysis was performed of the reaction of methylamine and phenazine ethosulphate (PES) with the quinoprotein methylamine dehydrogenase from Paracoccus denitrificans. Experiments with methylamine and PES as varied-concentration substrates produced a series of parallel reciprocal plots, and when the concentrations of these substrates were varied in a constant ratio a linear...

BACKGROUND AND OBJECTIVES Lipases are valuable biocatalysts which are widely used in the detergent, food, dairy and pharmaceutical industries. The aims of the present study included the isolation of a lipase-producer from industrial zones and the partial characterization of the enzyme. MATERIALS AND METHODS A number of bacteria were isolated from sites related to the oil industries. An isolat...