5,970 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

    Local type conditions for the CC^*-crossed product and sufficient families of representations

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    The local trajectories method establishes invertibility in an algebra B=alg(A,UG)\mathcal{B}= \operatorname{alg}(\mathcal{A}, U_G), for a unital CC^*-algebra A\mathcal{A} and a unitary group action UgU_g, gGg\in G, of a discrete amenable group GG on A\mathcal{A}. We introduce here a local type condition that allows to establish an isomorphism between B\mathcal{B} and a CC^*-crossed product, which is fundamental for the method to work. The influence of the structure of the fixed points of the group action is analysed and a new equivalent condition is introduced that applies when the action is not topologically free. If A\mathcal{A} is commutative, the referred conditions are related to the subalgebra alg(UG)\operatorname{alg}(U_G) yielding, in particular, a sufficient condition that depends only on the action. It is shown that in π(B)\pi(\mathcal{B}), with π\pi the local trajectories representation, the local type condition is verified, which allows establishing the isomorphism on the local trajectories method. It is analysed whether the family of representations of the local trajectories method is sufficient using the notions of strictly norming and exhaustive families. It is shown that if A\mathcal{A} is a commutative algebra or a matrix algebra of continuous functions the family is sufficient

    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

    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

    Produtividade da agricultura: resultados para o Brasil e estados selecionados.

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    Este trabalho analisa a produtividade da agricultura nos anos recentes, em especial no período de 2000 a 2012. O artigo estima indicadores de produtividade não apenas para o Brasil, mas também para uma seleção de estados. Estes foram escolhidos pela sua relevância na produção nacional de grãos e carnes. Para isso, foram escolhidos os estados da Bahia, Minas Gerais, São Paulo, Paraná, Rio Grande do Sul, Mato Grosso e Goiás. Utilizou-se o conceito de produtividade total dos fatores (PTF) porque ele oferece uma definição mais abrangente de produtividade do que medidas que comparam o produto a apenas um insumo, como trabalho ou terra. Esta última forma de mensuração da produtividade é chamada produtividade parcial. A PTF considera, em sua definição, a reunião de todos os produtos das lavouras e da pecuária e os relaciona com todos os insumos usados na produção
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