662 research outputs found

    Indium-Gallium Segregation in CuInx_{x}Ga1−x_{1-x}Se2_2: An ab initio based Monte Carlo Study

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    Thin-film solar cells with CuInx_xGa1−x_{1-x}Se2_2 (CIGS) absorber are still far below their efficiency limit, although lab cells reach already 19.9%. One important aspect is the homogeneity of the alloy. Large-scale simulations combining Monte Carlo and density functional calculations show that two phases coexist in thermal equilibrium below room temperature. Only at higher temperatures, CIGS becomes more and more a homogeneous alloy. A larger degree of inhomogeneity for Ga-rich CIGS persists over a wide temperature range, which may contribute to the low observed efficiency of Ga-rich CIGS solar cells

    Configuration management for Lyee software

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    This article presents a configuration management concept for software projects using Lyee methodology. To illustrate this concept, an introduction in configuration management is given. Then, the structure of Lyee programs is defined by sets and their dependencies. From this structure, the actual configuration management concept is deduced and discussed by rendering the structure for an existing configuration management testbed and describing the involved key players as well as the necessary procedures

    A Distributed Communication System for Integration with Logistics Software

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    Truckage companies need continuous and up-to-date information about their business processes in order to respond quickly to customers’ needs and problems emerging during transport processes. Therefore a reliable and user-friendly communication system is required, which improves the relationship between drivers and dispatchers. The project ”Mobile Spedition im Web (SpiW)**” presented here, develops a mobile communication system, which focuses on the driver/dispatcher interaction. The main goals are integration with legacy logistics software and the possible use of new telematics and communication techniques. To achieve these goals, a component based architecture allows the later change and extension of components, making it possible to add new features to the system as they become available. A distributed workflow server supports the adjustment of business processes to individual needs

    Agricultural growth linkages in Sub-Saharan Africa:

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    How much extra net income growth can be had in rural areas of Africa by increasing the spending power of local households? The answer depends on how rural households spend increments to income, whether the items desired can be imported to the local area in response to increased demand, and, if not, whether increased demand will lead to new local production or simply to price rises. For every dollar in new farm income earned, at least one additional dollar could be realized from growth multipliers, according to Agricultural Growth Linkages in Sub-Saharan Africa.Income Rural areas Africa., Agricultural development Africa., Agricultural policy Economic aspects., Households Zimbabwe., Social accounting., Africa sub-Saharan,

    Origins and mechanisms leading to aneuploidy in human eggs

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    The gain or loss of a chromosome—or aneuploidy—acts as one of the major triggers for infertility and pregnancy loss in humans. These chromosomal abnormalities affect more than 40% of eggs in women at both ends of the age spectrum, that is, young girls as well as women of advancing maternal age. Recent studies in human oocytes and embryos using genomics, cytogenetics, and in silico modeling all provide new insight into the rates and potential genetic and cellular factors associated with aneuploidy at varying stages of development. Here, we review recent studies that are shedding light on potential molecular mechanisms of chromosome missegregation in oocytes and embryos across the entire female reproductive life span

    Front-end electronics for drift tubes in a high-rate environment

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    A front-end electronics readout for drift tubes in a high-rate environment is presented. This system allows us to encode several pieces of information (leading edge time, trailing edge time, signal charge and piled-up hits from multiple tracks) into a single readout channel that is presented to the TDC. The advantage of active baseline restoration compared to bipolar signal shaping is discussed

    Rate effects in high-resolution drift chambers

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    The impact of high counting rates on the spatial resolution of cylindrical drift tubes is investigated in detail and the results are compared with simulations. Electronics effects and space-charge effects are quantitatively analysed. A spatial resolution of σ<80 Όm\sigma < 80\,\mu\mathrm{m} can be achieved even at rates as high as 1500\,Hz/cm wire length (300\,kHz per wire)

    Resolution limits of drift tubes

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    Measurements of the drift-tube response to charged particle tracks are compared with a complete simulation. The measured resolution of typically 80\,Ό\mum agrees well with the simulation and allows the individual factors limiting the resolution such as diffusion, charge deposit fluctuations, gas gain fluctuations and signal processing to be studied. The results with respect to the dependence of the drift chamber resolution on gas gain, gas pressure and electronics parameters are reported
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