5,741 research outputs found

    Developments in high-precision aspects of power converter control for LHC

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    The initial results from integration testing of the LHC magnet power converters revealed problems of lowfrequency noise, settling time, drift with time and temperature, thermal management and EMC. These problems originated in the use of DSP, the A/D converter (ADC), the DCCT and their respective environments. This paper reports the methods used to improve the performance through hardware and software modifications and the results achieved

    Oxygen Transfer In The Solid-state Cultivation Of D. Monoceras On Polyurethane Foam As Na Inert Support

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    In recent years, there has been a resurgence of interest concerning solid-state cultivation processes due to a number of advantages over submerged cultivation. However, studies on oxygen transfer and the performance of bioreactors are lacking. Processes that use inert supports loaded with chemically-defined liquid media have several potential applications and offer numerous advantages, such as improved process control and monitoring and enhanced process consistency compared with cultivation on natural solid substrates. The aim of this research was to study the oxygen transfer for the production of allergenic proteins from a biomass of Drechslera (Helminthosporium) monoceras cultured in a packed-bed reactor filled with polyurethane foam. The results show that a high protein concentration can be produced on an inert support with a high overall oxygen transfer coefficient (K(L)a) during cultivation.33479379911th Latin American Symposium on Anaerobic Digestion (DAAL)2014Havana, CUB

    High-precision performance testing of the LHC power converters

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    The magnet power converters for LHC were procured in three parts, power part, current transducers and control electronics, to enable a maximum of industrial participation in the manufacturing and still guarantee the very high precision (a few parts in 10-6) required by LHC. One consequence of this approach was several stages of system tests: factory reception tests, CERN reception tests, integration tests , short-circuit tests and commissioning on the final load in the LHC tunnel. The majority of the power converters for LHC have now been delivered, integrated into complete converter and high-precision performance testing is well advanced. This paper presents the techniques used for high-precision testing and the results obtained

    Oxygen transfer in the solid-state cultivation of D. Monoceras on polyurethane foam as an inert support

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    In recent years, there has been a resurgence of interest concerning solid-state cultivation processes due to a number of advantages over submerged cultivation. However, studies on oxygen transfer and the performance of bioreactors are lacking. Processes that use inert supports loaded with chemically-defined liquid media have several potential applications and offer numerous advantages, such as improved process control and monitoring and enhanced process consistency compared with cultivation on natural solid substrates. The aim of this research was to study the oxygen transfer for the production of allergenic proteins from a biomass of Drechslera (Helminthosporium) monoceras cultured in a packed-bed reactor filled with polyurethane foam. The results show that a high protein concentration can be produced on an inert support with a high overall oxygen transfer coefficient (KLa) during cultivation334793799CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESsem informaçã

    Basin structure in the two-dimensional dissipative circle map

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    Fractal basin structure in the two-dimensional dissipative circle map is examined in detail. Numerically obtained basin appears to be riddling in the parameter region where two periodic orbits co-exist near a boundary crisis, but it is shown to consist of layers of thin bands.Comment: published in J. Phys. Soc. Jpn., 72, 1943-1947 (2003

    Uma introdução à técnica SVET

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    Este artigo apresenta uma introdução à Técnica do Eléctrodo Vibrante de Varrimento (SVET). Começa por uma breve resenha histórica, seguida da descrição do princípio de funcionamento, exemplos da aplicação a casos de corrosão, alguns cálculos possíveis, limitações, instrumentação, detalhes experimentais e exemplos da sua associação a outras técnicas electroquímicas

    Aplicação da classificação supervisionada na análise temporal do uso da terra no projeto de assentamento José Emídio dos Santos, Capela/Sergipe, 199-2009.

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    Este trabalho tem como objetivo realizar uma análise das modificações ocorridas no Projeto de Assentamento José Emídio dos Santos, antiga Usina Santa Clara a partir da evolução temporal do uso da terra em dois períodos distintos. Para a avaliação foram utilizadas duas imagens de satélite Landsat 5 TM (Thematic Mapper) e posteriormente, a classificação supervisionada através do software ArcGIS, pelo método da máxima verossimilhança. A análise dos mapas temáticos com a evolução temporal do uso da terra no assentamento possibilitou melhor visualização das mudanças ocorridas no espaço geográfico em função das atividades antrópicas. As principais mudanças observadas referem-se à pressão demográfica e, a substituição de áreas anteriormente utilizadas com o monocultivo da cana de açúcar por uma diversificação de cultura de subsistência pelos assentados

    Evaporation of Electrolyte During SVET Measurements: The Scale of the Problem and the Solutions

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    The objective of this work is to investigate the scale of the effect of spontaneous solution evaporation during SVET (Scanning Vibrating Electrode Technique) measurements and demonstrate how it biases the final results. When SVET maps are continuously acquired for more than several hours, the measured currents are smaller than expected. This is attributed to solvent (typically water) evaporation which leads to an increase in solution conductivity over time. If this is not considered when converting the measured potential differences into the local current densities, the SVET results display currents smaller than the true ones. Here, this effect is studied with a platinum disk electrode as source of a constant current and a model corroding system consisting of the AA2024/CFRP galvanic couple. Corrective actions are proposed to mitigate the problem, either in the experimental set‐up or as numerical correction
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