443 research outputs found

    Structure of the Chiral Scalar Superfield in Ten Dimensions

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    We describe the tensors and spinor-tensors included in the θ\theta-expansion of the ten-dimensional chiral scalar superfield. The product decompositions of all the irreducible structures with θ\theta and the θ2\theta^2 tensor are provided as a first step towards the obtention of a full tensor calculus for the superfield.Comment: 50 pages, UCLA/94/TEP/

    Five-Brane Effective Field Theory on Calabi-Yau Threefolds

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    We consider the compactification of the dual form of N=1N=1 D=10D=10 supergravity on a six-dimensional Calabi-Yau manifold. An N=1N=1 off-shell supergravity effective Lagrangian in four dimensions can be constructed in a dual version of the gravitational sector (new-minimal supergravity form). Superspace duality has a simple interpretation in terms of Poincar\'{e} duality of two-form cohomology. The resulting 4D4D Lagrangian may describe the low-energy point-field limit of a five-brane theory, dual to string theory, provided Calabi-Yau spaces are consistent vacua of such dual theory.Comment: 16 pages, LaTeX, CERN-Th.6914/93 POLFIS-TH.04/93 UCLA/93/TEP/1

    Contextual Factors Surrounding Extradyadic High-Risk Sexual Decision-Making in Men: A Case-Oriented Perspective

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    Many models have been developed to explain the decision-making process of high-risk sexual behavior (HRSB). Juhasz and Sonnenshein-Schneider (1980) proposed a model for sexual decision-making with three distinct factors (socialization influences, factors germane to the situation, and cognitive factors). While this model makes sense from a theoretical standpoint, it has not been empirically validated and they have focused exclusively on adolescent sexual decision-making processes. The purpose of this study was to identify the key points in decision-making toward engagement in extradyadic high-risk sexual behavior. Using qualitative interviews in a case-oriented study, key components surrounding the context, decision-making, and management processes of engagement in high-risk sexual behavior were analyzed. We found that chemical impairment, sensation-seeking and impulsivity, quality of the relationship, and self-esteem were all key contributors to the context of engaging in HRSB. On the other hand, the decision-making process of HRSB contained compartmentalization, rationalization, and experiencing a point of no return. Finally, the management process of engaging in HRSB included dissociation, self-esteem, and contro

    Análisis estadístico de los nombres comerciales de maderas en un país (España)

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    La denominación comercial de las maderas es un tema extensamente tratado desde hace bastantes años. Sin embargo, la mayoría de los trabajos se limitan a recopilar nombres vulgares de una forma ordenada y más o menos extensa. En este estudio se examinan las denominaciones vulgares mediante la utilización de la estadística, fundamentalmente no paramétrica debido al carácter nominal de la variable. La metodología empleada permite detectar los nombres comerciales más utilizados mediante la moda y caracterizar la dispersión que presentan los alternativos a través del Índice de Variación Cualitativa y el Índice Bimodal (definido en este estudio). También se analiza el efecto que puede provocar la región geográfica o el tamaño de la empresa mediante la prueba exacta para tablas r x c y la regresión logística. Los resultados indican claras convergencias en los nombres vulgares de las frondosas europeas utilizadas en España. En el resto de maderas aparecen dispersiones asociadas principalmente a solo dos nombres (maderas tropicales) o a un número mayor (coníferas y frondosas americanas no tropicales). Respecto a las posibles alteraciones debidas al origen geográfico de la denominación comercial, solo una de las 92 maderas analizadas presenta valores significativos. El tamaño de la empresa no influye en el tipo de nombres comerciales que utiliza. Para el estudio del grado de seguimiento de la Normativa EN se utilizó el Índice de concordancia Kappa. Es destacable que la sociedad emplea escasamente las denominaciones recomendadas en esta Norma

    Mitigating slipping-related mortality from purse seine fisheries for small pelagic fish: case studies from European Atlantic waters

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    The release of unwanted catches (UWC) from purse seines, while the catch is still in the water, is known as “slipping”. Once thought to be a benign process, compared to discarding UWC overboard from the fishing vessel, it is now recognised that “slipping” can lead to significant mortality in the released fish if done inappropriately. In this chapter, we examine purse seining and slipping operations, and discuss what drives slipping and potential mitigation measures to reduce slipping mortality. We use three examples of purse seine fisheries for small pelagic species in the North-east Atlantic; from Norway, Portugal and Spain. The ideal solution (identifying and avoiding UWC before the net is set) requires the development of tools to enable fishers to better characterise target schools in terms of key selection criteria, e.g., with respect to species, individual size and catch biomass. Such tools are being developed, based primarily on hydro-acoustic technology. However, some UWC in purse seine catches are inevitable, and operational improvements in slipping practices have been shown to significantly reduce stress and mortality in the released UWC. We conclude with a discussion on the challenges currently facing the implementation of the European Union (EU) Landing Obligation with regards to minimising slipping related mortality.info:eu-repo/semantics/publishedVersio

    Solar active envelope module with an adjustable transmittance/absorptance

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    A solar active envelope module with a high flexibility degree is proposed in this paper. The transparent module controls the day-lighting of the room, improving the indoor environment, while absorbing the superfluous solar energy inside. That energy is used to increase the efficiency of heating, ventilation, and the air-conditioning (HVAC) system of the building. This is carried out through a fine control of the absorptance of the envelope module. The active envelope module consists of three glazed chambers with advanced coatings and frames to assure a minimum thermal transmittance while allowing transparency. A fluid containing heat-absorbing nanoparticles flows inside the central chamber and is heated up due to the impinging solar energy. Unlike other systems proposed in the past, which included transparency control systems based on complex filters and chemical processes, the absorption of the module is controlled by the variation of the thickness of the central chamber with a mechanical device. That is, varying the thickness of the central chamber, it allows controlling the absorptance of the whole system and, as a result, indoor day-lighting and thermal loads. Therefore, a new system is proposed that enables to

    Mechanical properties of wood from Pinus sylvestris L. treated with Light Organic Solvent Preservative and with waterbone Copper Azole

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    El objetivo del estudio es determinar el efecto de tratamiento de la madera de Pinus sylvestris con sustancias protectoras en las propiedades mecánicas. Para ello se utilizan 40 muestras de madera libre de defectos de Pinus sylvestris L. tratándose con protectores orgánicos (Vacsol Azure WR 2601) 50 con protectores hidrosolubles (Tanalith E 3492) y 40 muestras de control sin tratamiento. Se evaluó la resistencia mecánica a la flexión estática, módulo de elasticidad y la fuerza de compresión paralela a la fibra fueron comparados con madera no tratada. El análisis de regresión entre la penetración y la fuerza de compresión paralela se realizó con las muestras tratadas con conservante a base de agua. Resultados principales: Los resultados indican que la madera tratada (con cualquiera de los productos) presenta un aumento estadísticamente significativo de la resistencia mecánica en todas las tres características mecánicas. Los resultados obtenidos difieren de estudios anteriores llevada a cabo por otros autores. No hubo correlación entre la resistencia a la compresión en paralelo y el grado de impregnación de la madera con base de agua de cobre azoles. La explicación más probable para estos resultados se refiere a cambios en la presión durante el tratamiento. El uso de muestras de control no tratadas en lugar de las muestras tratadas sólo con agua es más probable para producir resultados significativos en los estudios de resistencia mecánica . La investigación pone de relieve que la madera tratada presenta un aumento estadísticamente significativo en el Modulo de Elasticidad, módulo de rotura a la flexión estática y resistencia a la compresión paralela. No hubo correlación entre la resistencia a la compresión en paralelo y el grado de impregnación con conservante hidrosoluble
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