Search results for "Channelling"
showing 4 items of 4 documents
Respiratory behaviour of a Zymomonas mobilis adhB::kan(r) mutant supports the hypothesis of two alcohol dehydrogenase isoenzymes catalysing opposite …
2006
AbstractPerturbation of the aerobic steady-state in a chemostat culture of the ethanol-producing bacterium Zymomonas mobilis with a small pulse of ethanol causes a burst of ethanol oxidation, although the reactant ratio of the alcohol dehydrogenase (ADH) reaction ([NADH][acetaldehyde][H+])/([ethanol][NAD+]) remains above the Keq value. Simultaneous catalysis of ethanol synthesis and oxidation by the two ADH isoenzymes, residing in different redox microenvironments, has been proposed previously. In the present study, this hypothesis is verified by construction of an ADH-deficient strain and by demonstration that it lacks the oxidative burst in response to perturbation of its aerobic steady-s…
CHANNELING EXPERIMENTS WITH ELECTRONS AT THE MAINZ MICROTRON MAMI
2010
The dechanneling process of electrons in silicon single crystals has been studied at the Mainz Microtron MAMI for (110)-planar channeling of electrons at beam energies between 195 and 855 MeV. Dechanneling lengths were derived from a high and a low energy loss signal of the electrons which were recorded as function of the crystal orientation with respect to the beam direction for various crystal thicknesses in the range between 14.7 µm and 467 µm. The high energy loss signal corresponds to an energy loss of about 75 % of the total electron energy by emission of a bremsstrahlung photon, while the low energy signal to an energy loss of 0.7-1.7 % by emission of channelling radiation. While th…
On erbium lattice location in ion implanted Si0.75Ge0.25 alloy
2003
A high crystalline quality Si0.75Ge0.25 alloy layer grown by chemical vapor deposition was implanted with 70 keV Er+ ions to a fluence of 1015 cm−2 at temperature of 550 °C. The implantation was found to result in an Er depth distribution with 1 at. % maximum concentration 30 nm beneath the surface. The location of the erbium atoms in the host matrix lattice is derived through computer simulation of experimental axial channeling angular scans measured by in situ Rutherford backscattering/channeling spectrometry. Using computer code FLUX 7.7 it is shown that 60% of the implanted erbium atoms are located at ytterbium sites, 10% at tetrahedral sites, and the remainder are associated with rando…
Nuevas perspectivas de análisis para entender la migración cualificada del sur de Europa hacia México
2018
This article focuses on skilled migration flows from Southern Europe into Mexico. From semi-structured interviews with Spanish and Italian immigrants living in four Mexican cities of Mexico, it addresses both reasons for immigration and labour incorporation in Mexican labour markets. Specifically, it explores: i) the role of the economic crisis and the lack of good employment in the countries of origin as a key factor when deciding an international migration; ii) the employment opportunities offered in Mexican labour markets for the highly-skilled immigrants, and iii) the role played by the Mexican state and its current immigration law when channelling this group into the labour market