The impact of defects on the performance of p- and n-side illuminated microcrystalline silicon solar cells is investigated. The absorber layer spin density NS is controlled over some two orders of magnitude by electron bombardment and subsequent annealing steps. At increased NS (between 3x1016 and 1018 cm-3) performance of n-side illuminated cells is much more strongly reduced relative to p-side illuminated cells, particularly with regard to short circuit current density. Quantum efficiency measurements indicate a corresponding strong asymmetry in wavelength-dependence, which has been successfully reproduced by numerical device simulations. / Copyright (2012) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

Cultures of the fungi Aspergillus niger, Cunninghamella verticillata, and Penicillium simplicissimum, grown in a sucrose/peptone medium, transformed N-acetylphenothiazine to N-acetylphenothiazine sulfoxide (from 13% to 28% of the total) and phenothiazine sulfoxide (from 5% to 27%). Phenothiazin-3-one (4%) and phenothiazine N-glucoside (4%) were also produced by C. verticillata. The probable intermediate, phenothiazine, was detected only in cultures of P. simplicissimum (6%)

The NHase encoding gene of mutant 4D was isolated by PCR amplification. The NHase gene of mutant 4D was successfully cloned and expressed in Escherichia coli by using Ek/LIC Duet cloning kits (Novagen). For the active expression of the NHase gene, the co-expression of small cobalt transporter gene (P-protein gene) has also been co-expressed with NHase gene E. coli. The nucleotide sequence of this NHase gene revealed high homology with the H-NHase of Rhodococcus rhodochrous J1. The recombinant E. coli cells showed higher NHase activity (5.9 U/mg dcw) as compared to the wild (4.1 U/mg dcw) whereas it is less than the mutant strain (8.4 U/mg dcw). Addition of cobalt ion in Luria– Bertani medium is needed up to a very small concentration (0.4 mM) for NHase activity. The recombinant E. coli exhibited maximum NHase activity at 6 h of incubation and was purified with a yield of 56 % with specific activity of 37.1 U/mg protein.

The saturated nitrogen-containing heterocyclic compounds include many drugs and compounds that may be used as synthons for the synthesis of other pharmacologically active substances. The need for new derivatives of saturated nitrogen-containing heterocycles for organic synthesis, biotechnology and the pharmaceutical industry, including optically active derivatives, has increased interest in microbial synthesis. This review provides an overview of microbial technologies that can be valuable to produce new derivatives of saturated nitrogen-containing heterocycles, including hydroxylated derivatives. The chemo-, regio- and enantioselectivity of microbial processes can be indispensable for the synthesis of new compounds. Microbial processes carried out with fungi, including Beauveria bassiana, Cunninghamella verticillata, Penicillium simplicissimum, Aspergillus niger and Saccharomyces cerevisiae, and bacteria, including Pseudomonas sp., Sphingomonas sp. and Rhodococcus erythropolis, biotransform many substrates efficiently. Among the biological activities of saturated nitrogen-containing heterocyclic compounds are antimicrobial, antitumor, antihypertensive and anti-HIV activities; some derivatives are effective for the treatment and prevention of malaria and trypanosomiasis, and others are potent glycosidase inhibitors.

Soft X-ray absorption (XAS) and emission (XES) spectroscopies were applied to determine valence states of manganese ions in nanostructured powder of halfdoped La0:5Ca0:5MnO3 manganite obtained by milling in a ball mill. XAS spectra were measured both in surfacesensitivity total electron-yield and in bulk-sensitivity total fluorescence-yield modes. O Ka XES and O 1s XAS spectra characterized the occupied and unoccupied partial O 2p densities of states are compared with band-structure calculations made using the TB-LMTO-ASA codes. Experimental Mn 2p, Ca 2p, and La 3d XAS spectra are compared with results of crystal field atomic multiplet calculations. For the nanostructured system of La0:5Ca0:5MnO3, concentrations of Mn4þ ions are found to be increased with increasing the time of milling.