Thin alumina films have found applications in electronic circuits and cutting tools and have been recently explored as protective coatings against high temperature oxidation, but these studies have been relatively rare. In this study, amorphous alumina films 3.5 pm thick were produced by reactive sputtering on Co-30Cr-6Al-0.5Y coatings, using a pure aluminum target in Ar + 0 2 atmosphere. Isoth...

A comparison of the distribution of CO oxidation activity between soluble and particulate protein fractions obtained after disruption of CO-grown Rhodopseudomonas gelatinosa 1 by French pressure cell breakage and osmotic lysis of spheroplasts suggested that, in situ, the enzyme complex was associated with the cell membrane. An improved, strictly anaerobic method is given for spectrophotometric ...

Surface immobilized polyamidoamine (PAMAM) dendrimer templated Pt nanoparticles were employed as precursors to heterogeneous catalysts. CO oxidation catalysis and in situ infrared spectroscopy were used to evaluate conditions for dendrimer removal. Infrared spectroscopy showed that PAMAM dendrimer amide bonds begin decomposing at temperatures as low as 75 degrees C. Although the amide stretches...

A cellular automaton model is used to describe the dynamics of the catalytic oxidation of CO on a Pt(100) surface. The cellular automaton rules account for the structural phase transformations of the Pt substrate, the reaction kinetics of the adsorbed phase and diffusion of adsorbed species. The model is used to explore the spatial structure that underlies the global oscillations observed in so...

Carotenoid extract from ripe tomato fruit was subjected to a lipoxygenase-catalysed co-oxidation in the presence of vitamin C and vitamin E at different concentrations. Relative retention (%) of major carotenoids by the experimental mixture was used as an index of their degradation and interaction with the antioxidants. Oxidation-prevention activity of each antioxidant against pigment co-oxidat...

We report a study of the oxidation of CO on a gold nanotip in the presence of high electrostatic fields. With the binding energies obtained using density functional theory as a function of the electric field, a simple field-dependent kinetic model based on the Langmuir-Hinshelwood mechanism is set up. We show that the dissociative adsorption of oxygen on gold happens only below a negative criti...

The electrochemical oxidation of formic acid was studied by the tip generation-substrate collection (TG-SC) mode of scanning electrochemical microscopy (SECM), extending the number of applications of SECM in electrocatalysis. Formic acid was generated at a Hg on Au ultramicroelectrode (UME) tip by reduction of CO(2) in a 0.1 M KHCO(3) solution saturated with this gas. The electrocatalytic activ...

Numerous studies have confirmed the role of endogenous carbon monoxide (CO) gas as a signal transmitter. However, CO is considered an intracellular transmitter, as no studies have demonstrated the redistribution of CO from the blood to tissue cells. Tracer analyses of 13CO2 production following 13CO gas inhalation demonstrated that CO is oxidized to carbon dioxide (CO2) in the body and that CO ...

In order to enhance the resistance of cobalt nanoparticles to oxidation in air, the impact of different stabilization strategies on the isothermal oxidation of particle dispersions and powders was kinetically investigated and compared to as-prepared particle preparations. A post-synthesis treatment with different alcohols was employed, and we also investigate the influence of two different poly...

Reduction of fully oxidized Clostridium pasteurianum 8-Feox.,ox. ferredoxin by using pulse-radiolysis techniques yields the half-reduced species 8-Feox.,red. ferredoxin. The subsequent oxidation of 8-Feox.,red. ferredoxin with Co(NH3)5Cl2+ was studied. From a comparison with stopped-flow studies on the 2:1 Co(NH3)5Cl2+ oxidation of 8-Fered.,red. ferredoxin to the 8-Feox.,ox. form it is conclude...