The hydrogenase in Azotobacter vinelandii, like other membrane-bound [NiFe] hydrogenases, consists of a catalytic heterodimer and an integral membrane cytochrome b. The histidines ligating the hemes in this cytochrome b were identified by H(2) oxidation properties of altered proteins produced by site-directed mutagenesis. Four fully conserved and four partially conserved histidines in HoxZ were...

Partial oxidation of methane in monolithic catalysts at very short contact times has recently been shown to offer a promising route to convert natural gas into syngas (CO, H2), which can subsequently be converted to higher alkanes or methanol. Detailed models are needed to understand the complex interaction of transport and kinetics occurring in these reactors. In this work, the partial oxidati...

The partial oxidation and CO2 reforming of methane were studied on Pt/Al2O3, Pt/ZrO2, and Pt/ Ce–ZrO2 catalysts. The reducibility and the oxygen transfer capacity were evaluated by oxygen storage capacity (OSC). The effect of the support on the cleaning mechanism of the catalyst surface was investigated by the sequence of CH4/O2 and CH4/CO2 pulses. The Pt/Ce–ZrO2 catalyst showed the highest sta...

Because of their various potential applications, non-porous, selective oxygen permeable ceramic membranes with mixed ionic and electronic conductivity (MIECs) have received significant interest over the past decade [1-8]. In particular, the incorporation of these materials into catalytic reactors for the oxidation of hydrocarbons is being investigated as a way to eliminate costly air separation...

A sampling and measuring device was set up to measure continuously the pH and the redox potential (Eh) of ruminal content in absence of any gaseous contamination (method 1). It was compared with a conventional suction device in which no precaution was taken to prevent air from coming into contact with the surface of collected samples (method 2). Two fistulated dry cows were used and fed a total...

The syntheses and structural elucidations of three different cobalt complexes of m-benziphthalocyanine are reported; both Co(II) and Co(III) complexes can be generated, and the ring undergoes partial oxidation upon metalation with Co(OAc)2x4H2O.

We have used laser-initiated chemical vapor deposition to grow the chromium oxide thin films through the oxidation of Cr~CO!6 in an oxygen environment. While both Cr2O3 and CrO2 are present in the film, the relative weight of each phase depends on the oxygen partial pressure. The Curie temperature of the film increases and approaches the bulk TC of CrO2 ~397 K! as the partial oxygen pressure is...

The effect of the partial antiaromaticity of biphenylene on its substitution chemistry, its oxidation potential, and its single-molecule conductance is explored. Biphenylene and fluorene molecules with linkers of two amino groups or two cyclic thioether groups were synthesized and their conduction properties were investigated using scanning tunneling microscopy (STM) break-junction techniques a...

This study investigated the influence of dissolved oxygen concentration and aeration time on nitrification and nitrite accumulation in an attempt to optimize the recently developed biological-partial-nitritation process for the treatment of strong nitrogen wastewaters. Investigation of dissolved oxygen concentration on ammonium and nitrite oxidation was carried out in a batch reactor. The disso...