Evaluation of Pt and Re oxidation state in a pressurized reactor: difference in reduction between gas and liquid phase

Determination of metal oxidation state under relevant working conditions is crucial to understand catalytic behaviour. The reduction behaviour of Pt and Re was evaluated simultaneously as a function of support and solvent in a pressurized reactor (autoclave). The bimetallic catalysts are used in selective hydrogenation of carboxylic acids and amides. Gas phase reduction reduced the metals more efficiently, in particular Pt.

Plays of Difference

Review-essay

Reactivity difference between protolytic forms of some macrocyclic chromium(III) complexes in ligand substitution and electron transfer processes

The review provides insight into the mechanism of ligand substitution and electron transfer (from chromium(III) to iron(III)) by comparison of the reactivity of some tetraazamacrocyclic chromium(III) complexes in the conjugate acid-base forms. Use of two geometrical isomers made possible to estimate the influence of geometry and protolytic reactions in trans and cis position towards the leaving group on the rate enhancement. Studies on the reaction rates in different media demonstrated the role played by outer sphere interactions in a monodentate ligand substitution. (C) 2009 Published by Elsevier B.V.

EFFECT OF EXERCISE ON THE NASAL TRANSMUCOSAL POTENTIAL DIFFERENCE IN PATIENTS WITH CYSTIC-FIBROSIS AND NORMAL SUBJECTS

Background - Normal subjects have a negative nasal transmucosal potential difference (TPD) at rest which becomes more negative with exercise. Patients with cystic fibrosis have a more negative resting nasal TPD than controls. The present study was designed to determine the effects of exercise on the TPD of patients with cystic fibrosis.

COLLISIONALLY EXCITED X-RAY LASER SCHEMES - PROGRESS AT RUTHERFORD APPLETON LABORATORY

Characteristics of the 3p-3s amplified spontaneous emission from Ne-like Ge plasma columns, generated by ablation from massive targets, have been studied in detail. In particular, the gain coefficients of the J = 2-1 lines at 23.2 and 23.6 nm have been measured as a function of incident intensity for a 1.05-mu-m wavelength pump laser beam. For 100-mu-m wide stripe targets and a fixed energy pump laser the maximum gain length product is achieved at an irradiance of

THE EXPANSION HISTORY OF ALUMINUM TARGETS RELEVANT TO X-RAY LASER SCHEMES

For the first time, the technique of point projection absorption spectroscopy - which uses an intense, point source of X-rays to project and spectrally disperse an image of a plasma onto a detector- has been shown to be applicable to the study of expanding aluminium plasmas generated by approximately 80ps (2-omega) laser pulses. Massive, stripe targets of approximately 125-mu-m width and wire targets of 25-mu-m diameter have been studied. Using a PET Bragg crystal as the dispersive element, a resolving power of approximately 3500 was achieved with spatial resolution at the 5-mu-m level in frame times of the order of 80ps. Reduction of the data for times up to 150ps after the peak of the incident laser pulse produced estimates of the temperature and densities present, as a function of space and time.