939 resultados para Si doping


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As revealed for the first time by in situ scanning tunnelling spectroscopy (STS), ferrocene-modified Si(111) substrates show ambipolar field effect transistor (FET) behaviour upon electrolyte gating.

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Utilization of biogas can provide a source of renewable energy in both heat and power generation. Combustion of biogas in land-based gas turbines for power generation is a promising approach to reducing greenhouse gases and US dependence on foreign-source fossil fuels. Biogas is a byproduct from the decomposition of organic matter and consists primarily of CH4 and large amounts of CO2. The focus of this research was to design a combustion device and investigate the effects of increasing levels of CO2 addition to the combustion of pure CH4 with air. Using an atmospheric-pressure, swirl-stabilized dump combustor, emissions data and flame stability limitations were measured and analyzed. In particular, CO2, CO, and NOx emissions were the main focus of the combustion products. Additionally, the occurrence of lean blowout and combustion pressure oscillations, which impose significant limitations in operation ranges for actual gas turbines, was observed. Preliminary kinetic and equilibrium modeling was performed using Cantera and CEA for the CH4/CO2/Air combustion systems to analyze the effect of CO2 upon adiabatic flame temperature and emission levels. The numerical and experimental results show similar dependence of emissions on equivalence ratio, CO2 addition, inlet air temperature, and combustor residence time. (C) 2014 Elsevier Ltd. All rights reserved.

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Disaccharide intolerance I or congenital sucrase-isomaltase deficiency (CSID) is a disorder leading to maldigestion of disaccharides, which is autosomal recessively inherited. Here we analyzed the sucrase-isomaltase (SI) gene from 11 patients of Hungarian origin with congenital sucrase-isomaltase deficiency. Variants in the SI gene had previously been described in CSID patients, which cause amino acid exchanges that affect the transport, the processing, or the function of the SI protein. None of our patients had known mutations for CSID. Our analyses revealed 43 SI variants in total, 15 within exons and one at a splice site. Eight of the exonic mutations lead to amino acid exchanges, causing hypomorph or null alleles. One new variation affects a splice site, which is also predicted to result in a null allele. All potential pathological alterations were present on one allele only. In six out of the 11 patients the phenotype of CSID could be explained by compound heterozygosity.

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Doping in sport is often very present in the media. Doping does not only concern top level sports but it also has an impact on sport as a whole. Young athletes may be influenced by its role models. In Switzerland there are no exact data on this influence or on the use of doping by adolescents. In this article, the effects and side-effects especially on adolescents of some current doping substances are discussed. As well, the regulations of the therapeutic use exemptions for doping substances are explained.