842 resultados para Biosusceptometry of Alternate Current


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Discussion of the numerical modeling of NDT methods based on the potential drop and the disruption of power lines to describe the nature, importance and application of modeling. La 1ère partie est consacrée aux applications aux contrôles par courants de Foucault. The first part is devoted to applications for inspection by eddy currents.

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Control by voltage drop DC. Contrôle par chute de potentiel de courant alternatif. Control by voltage drop AC.

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Solar outputs during the current solar minimum are setting record low values for the space age. Evidence is here reviewed that this is part of a decline in solar activity from a grand solar maximum and that the Sun has returned to a state that last prevailed in 1924. Recent research into what this means, and does not mean, for climate change is reviewed.

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This paper provides an overview of the reduction targets that Ireland has set in the context of decarbonising their electricity generation through the use of renewables. The main challenges associated with integrating high levels (>20% of installed capacity) of non-dispatchable renewable generation are identified. The rising complexity of the challenge as renewable penetration levels increase is highlighted. A list of relevant research questions is then proposed, and an overview is given into the previous work that has gone into answering some of them. In particular, studies into the Irish energy market are identified, the current knowledge gap is described, and areas of necessary future research are suggested

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First defined in the mid-1990s, prebiotics, which alter the composition and activity of gastrointestinal (GI) microbiota to improve health and well-being, have generated scientific and consumer interest and regulatory debate. The Life Sciences Research Organization, Inc. (LSRO) held a workshop, Prebiotics and the Health Benefits of Fiber: Future Research and Goals, in February 2011 to assess the current state of the science and the international regulatory environment for prebiotics, identify research gaps, and create a strategy for future research. A developing body of evidence supports a role for prebiotics in reducing the risk and severity of GI infection and inflammation, including diarrhea, inflammatory bowel disease, and ulcerative colitis as well as bowel function disorders, including irritable bowel syndrome. Prebiotics also increase the bioavailability and uptake of minerals and data suggest that they reduce the risk of obesity by promoting satiety and weight loss. Additional research is needed to define the relationship between the consumption of different prebiotics and improvement of human health. New information derived from the characterization of the composition and function of different prebiotics as well as the interactions among and between gut microbiota and the human host would improve our understanding of the effects of prebiotics on health and disease and could assist in surmounting regulatory issues related to prebiotic use.

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Individual-level constructs are seldom taken into consideration in construction management research relating to project performance. This is antithetical to the objectives of properly conceptualizing and contextualizing the research we do because many project performance outcomes, such as the extent of cooperation and level of communication or teamwork are influenced and moderated by individuals’ perceptions, values and behaviour. A brief review of the literature in organizational studies centred on culture, identity, empowerment and trust is offered. These constructs are then explored in relation to project performance issues and outcomes, and it is noted that they are predominantly studied at the project and industry levels. We argue that focusing these constructs at the individual unit of analysis has significant implications for project performance and therefore their effects need to be systematically accounted for in explanations of the success and failure of projects. Far from being prescriptive, the aim is to generate interest and awareness for more focused research at the individual level of analysis in order to add new insights and perspectives to critical performance questions in construction management. To this end, a research agenda is outlined, arguing that construction management research integrating individual-level constructs and broader, macro-contextual issues will help define and enhance the legitimacy of the field.

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Changes in landscape composition and structure may impact the conservation and management of protected areas. Species that depend on specific habitats are at risk of extinction when these habitats are degraded or lost. Designing robust methods to evaluate landscape composition will assist decision- and policy-making in emerging landscapes. This paper describes a rapid assessment methodology aimed at evaluating landcover quality for birds, plants, butterflies and bees around seven UK Natura 2000 sites. An expert panel assigned quality values to standard Coordination of Information on the Environment (CORINE) landcover classes for each taxonomic group. Quality was assessed based on historical (1950, 1990), current (2000) and future (2030) land-cover data, the last projected using three alternative scenarios: a growth applied strategy (GRAS), a business-as-might-beusual (BAMBU) scenario, and sustainable European development goal (SEDG) scenario. A quantitative quality index weighted the area of each land-cover parcel with a taxa-specific quality measure. Land parcels with high quality for all taxonomic groups were evaluated for temporal changes in area, size and adjacency. For all sites and taxonomic groups, the rate of deterioration of land-cover quality was greater between 1950 and 1990 than current rates or as modelled using the alternative future scenarios (2000– 2030). Model predictions indicated land-cover quality stabilized over time under the GRAS scenario, and was close to stable for the BAMBU scenario. The SEDG scenario suggested an ongoing loss of quality, though this was lower than the historical rate of c. 1% loss per decade. None of the future scenarios showed accelerated fragmentation, but rather increases in the area, adjacency and diversity of high quality land parcels in the landscape.

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A Base-da-Pirâmide (Base ofthePyramid- BoP) é referida na literatura como sendo o segmento sócio-econômico mais baixo em termos de paridade do poder de compra. Esse segmento encontrase geralmente excluído do sistema capitalista global. Esta tese analisa o tema BoP e discute dentro de um contexto sócio-econômico, como essa abordagem se relaciona com outras áreas de pesquisa, assim como a teoria do desenvolvimento internacional e a teoria de negócios internacionais. Estas duas teorias são identificadas como tendo uma relação mais forte com BoP. No que se segue, a abordagem BoP é incorporada nessas duas teorias com o objetivo de tornar este conceito mais claro e abrangente. Seguindo este raciocínio a abordagem BoP vem identificar contribuições no tocante a cada uma dessas abordagens teóricas. O argumento principal da tese é que a abordagem BoP é capaz de ligar essas duas teorias (teoria do desenvolvimento internacional e a teoria de negócios internacionais) em um só modelo teórico, mostrando assim que essas duas abordagens teóricas distintas podem na realidade serem complementares.

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This paper describes an alternative procedure to obtain an equivalent conductor from a bundled conductor, taking into account the distribution of the current in subcondutors of the bundle. Firstly, it is introduced a brief background about the concept of Geometric Mean Radius (GMR) and how this methodology is applied to define an equivalent conductor and its electric parameters. Emphasizing that the classical procedure, using GMR, is limited to premise which the current is equally distributed through subconductors. Afterwards, it is described the development of proposed method and applications for an equivalent conductor obtained from a conventional transmission line bundled conductor and from an equivalent conductor based on a bundle with compressed SF(6) insulation system, where the current is unequally distributed through subconductors.

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The aim of this in vivo study was to evaluate the biocompatibility of three current bonding agents and calcium hydroxide cement. Sixty polyethylene tubes filled with the following materials: Group 1: Prime & Bond NT (PB - Dentsply, US; Group 2: Bond 1 (BO - Jeneric/Pentron, US); Group 3: Optibond Solo (OP - Kerr, US); and Group 4 (control): calcium hydroxide cement - Dycal (CH - Dentsply, US) were implanted into the connective tissue of 30 rats. After 15, 30 and 60 days, the implants were excised and the animals sacrificed. The biopsies were immersed in Karnovsky (pH, 7.2) fixative solution for 48 hours, and processed using routine histological technique. Six-micron-thick sections were cut and stained with hematoxilin and eosin and Masson's trichome technique. Microscopic evaluation was used to compare the connective tissue reactions caused by the experimental and control materials adjacent to the tube opening. At 15 days, the experimental and control materials triggered a moderate to intense inflammatory response which gave rise to a thick capsule adjacent to the tube opening. With time, the inflammatory reaction decreased. At 60 days, the connective tissue adjacent to the bonding agents exhibited a persistent inflammatory response mediated by macrophages and giant cells which were engulfing displaced resin components. on the other hand, for the control group (calcium hydroxide) no inflammatory response associated with a thin capsule adjacent to the material was observed even at the 30-day period. The hard-setting calcium hydroxide cement allowed complete healing and was considered more biocompatible than the bonding agents.

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RACIONAL: Fato de observação não rara, é o encontro de refluxo cecoileal durante realização de enema opaco. As causas e conseqüências deste achado têm sido pouco estudadas. OBJETIVOS: Sabendo que a junção ileocecal exerce função de barreira e proteção contra a invasão do delgado pela flora colônica, realizou-se o presente estudo com a finalidade de investigar se existe contaminação ileal em indivíduos com refluxo cecoileal ao enema opaco. MÉTODOS: Investigaram-se 36 indivíduos, 30 mulheres e 6 homens, idade média de 54 anos, 25 com e 11 com ausência refluxo cecoileal. Todos submetidos a pesquisa de contaminação bacteriana do delgado por intermédio de teste respiratório com lactulose-H2 e a determinação do tempo de trânsito orocecal por meio de biossusceptometria de corrente alternada. A caracterização da contaminação do delgado foi baseada no encurtamento do tempo de trânsito orocecal medido pelo teste da lactulose-H2. RESULTADOS: A comparação dos valores basais do H2, do tempo de trânsito orocecal-H2 e tempo de trânsito orocecal-biossusceptometria de corrente alternada não diferiram estatisticamente entre os grupos com e sem refluxo cecoileal. Quando comparados os tempo de trânsito orocecal-H2 e tempo de trânsito orocecal-biossusceptometria, foi observado aumento de tendência de redução do primeiro em relação ao último nos grupos com refluxo cecoileal e correlação significante entre os dois métodos apenas no grupo-controle, inexistindo nos com refluxo cecoileal. CONCLUSÃO: Encurtamento do tempo de trânsito orocecal-H2 e sua perda de correlação com o tempo de trânsito orocecal-biossusceptometria observado em indivíduos com refluxo cecoileal, sugerem comportamento diferenciado deste grupo em relação ao grupo-controle. Possível explicação para as diferenças registradas entre os grupos, seria a presença de flora anômala nos indivíduos com refluxo cecoileal.

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BaBi2Ta2O9 thin films having a layered structure were fabricated by metalorganic solution deposition technique. The films exhibited good structural, dielectric, and insulating properties. The room temperature resistivity was found to be in the range of 10(12)-10(14) Omega cm up to 4 V corresponding to a field of 200 kV/cm across the capacitor for films annealed in the temperature range of 500-700 degrees C. The current-voltage (I-V) characteristics as a function of thickness for films annealed at 700 degrees C for 1 h, indicated bulk limited conduction and the log(I) vs V-1/2 characteristics suggested a space-charge-limited conduction mechanism. The capacitance-voltage measurements on films in a metal-insulator-semiconductor configuration indicated good Si/BaBi2Ta2O9 interface characteristics and a SiO2 thickness of similar to 5 nm was measured and calculated. (C) 1999 American Institute of Physics. [S0003-6951(99)00830-X].