Christof T. Klein

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Kinetic studies are presented for the growth and fermentation of the yeast Pichia stipitis with xylose as the carbon source. Ethanol is produced from xylose under anaerobic as well as under oxygen-limiting conditions but only at dissolved oxygen concentrations up to 3 mumol/L Maximum yields and production rates were obtained under oxygen-limiting(More)
The oxidation of Pd(111) leads to an incommensurate surface oxide, which was studied by the use of scanning tunneling microscopy, surface x-ray diffraction, high resolution core level spectroscopy, and density functional calculations. A combination of these methods reveals a two-dimensional structure having no resemblance to bulk oxides of Pd. Our study(More)
By means of spin-polarized low-energy electron microscopy, we show that the magnetic easy axis of one to three atomic-layer thick cobalt films on Ru(0001) changes its orientation twice during deposition: One-monolayer and three-monolayer thick films are magnetized in plane, while two-monolayer films are magnetized out of plane. The Curie temperatures of(More)
Zircon (ZrSiO(5)) has been identified as an accessory mineral in the Vaca Muerta mesosiderite and in the troilite nodules of the Toluca iron meteorite. The occurrence in Vaca Muerta is a new discovery confirmned by electron-probe nmicroanalysis of a grain in a polished section of the meteorite. Our identification of zircon in Toluca substantiates an(More)
The new mineral NaCrSi(2)0(6) (ureyite) has been found as rareemeraldgreen grains in the iron meteorites Coahuila, Toluca, and Hex River Mountains. X-ray studies of the natural and synthetic material have established that the mineral is isostructural with jadeite, NaAlSi(2)0(6). Indexed data for powder patterns obtained by x-ray diffraction and precise cell(More)
At low tunneling resistance, scanning tunneling microscopy (STM) images of a Rh(100) surface with adsorbed hydrogen reproducibly show protrusions in all bridge sites of the surface, leading to a naive interpretation of all bridge sites being occupied with H atoms. Using quantitative low-energy electron diffraction and temperature programmed desorption we(More)
Mineralogical descriptions and both wet chemical analyses and microprobe analyses are given of the glasses and crystalline components of the lunar fines and of the minerals in microgabbros (samples 10050 and 10047). The principal minerals described are various clinopyroxenes, plagioclase, olivine, low cristobalite, low tridymite, ilmenite, iron-nickel,(More)
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