78,381 research outputs found
Estudio de las propiedades metalúrgicas de los aceros martensíticos de activación reducida para su aplicación en los reactores de fusión
No full textEl desarrollo de los materiales estructurales de la primera pared y del "blanket es uno de los aspectos claves para la realización del futuro reactor de fusión nuclear. En esta Tesis Doctoral se han estudiado las propiedades microestructurales y mecánicas de los aceros de activación reducida denominados F-82H-mod y Eurofer´97 con el objetivo de contribuir al conocimiento de sus características metalúrgicas y al entendimiento de los mecanismos de degradación y envejecimiento térmico con o sin la aplicación de una carga (termofluencia) que pueden sufrir estos materiales como consecuencia de su operación. Los estudios se han realizado en el material en estado de recepción y en el material envejecido térmicamente simulando las condiciones de operación del reactor, en el rango de temperaturas comprendido entre 300°C y 600°C hasta periodos de 10000 horas. En general, ambos materiales presentan una alta estabilidad microestructural en la condiciones estudiadas hasta 500°C que se refleja en sus propiedades mecánicas Sin embargo para temperaturas de envejecimiento superiores a 500°C o fluencia térmica, la microestructura de estas aleaciones evoluciona con la formación de nuevas fases, que dan lugar a una degradación significativa de las propiedades de impacto para el acero F-82H-mod y una pérdida de resistencia a fluencia para la aleación Eurofer´9
The relationship between civic attitudes and voting intention : an analysis of vocational upper secondary schools in England and Singapore
No full textFrom 2009 to 2011, a team from the Centre for Learning and Life Chances in Knowledge Economies and Societies carried out a mixedmethods study of young people in England and Singapore. With regard to civic attitudes, the study showed that there was a greater sense of political self-efficacy and collective (school) efficacy in Singapore than in England. In addition, the group in Singapore scored higher on future voting relative to the group in England. Further, while both political self-efficacy and collective (school) efficacy were correlated with future voting in England, only the latter was correlated in the case of Singapore. For some, the results may seem counter-intuitive. The article reflects on these results, particularly those relating to democratic outcomes
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
Recuperación y conservación de cultivares tradicionales de melón castellano-manchego
No full textLos trabajos realizados han sido financiados por el proyecto INIARF2008-00003-C02.Ribas, F.; Cabello, M.; Castellanos, MT.; Fita, A.; Roig Montaner, MC.; Nuez Viñals, F.; Picó Sirvent, MB. (2011). Recuperación y conservación de cultivares tradicionales de melón castellano-manchego. Agrícola Vergel. 347:206-213. https://riunet.upv.es/handle/10251/49390S20621334
Cambio climático y proliferación de vectores.
No full textEl impacto que tiene los cambios de temperatura a la tierra traen una serie de consecuencia principalmente afecta a las latitudes norte superiores; además se observa que la regiones terrestres se han calentado más rápido que los océanos, estos juegan un papel central en el clima por su capacidad de almacenar, transportar y liberar grandes cantidades de calor mediante sus interacciones con la atmósfera y con los suelos. Las consecuencia que tiene estos cambios de temperatura: es el aumento del mar, sequía, enfermedades por parte de insectos y animales. En El Salvador las acciones de mitigación que se están tomando para reducir este gran impacto son las siguientes: crear programas para la deforestación y degradación de bosques , tener buen uso de la energía, programa de manejo de desechos sólidos entre otros; para que todos estos proyectos se lleven a cabo se han creado leyes y reformas para garantizar su desarrollo
Some new methods for the comparison of two linear regression models
No full textThe frequently used approach to the comparison of two linear regression models is to use the partial F test. It is pointed out in this paper that the partial F test has in fact a naturally associated two-sided simultaneous confidence band, which is much more informative than the test itself. But this confidence band is over the entire range of all the covariates. As regression models are true or of interest often only over a restricted region of the covariates, the part of this confidence band outside this region is therefore useless and to ensure 1 - ? simultaneous coverage probability is therefore wasteful of resources. It is proposed that a narrower and hence more efficient confidence band over a restricted region of the covariates should be used. The critical constant required in the construction of this confidence band can be calculated by Monte Carlo simulation. While this two-sided confidence band is suitable for two-sided comparisons of two linear regression models, a more efficient one-sided confidence band can be constructed in a similar way if one is only interested in assessing whether the mean response of one regression model is higher (or lower) than that of the other in the region. The methodologies are illustrated with two examples
Comparison of the magnetic properties between Y-3(Fe, Cr)(29) and Y2Fe15Cr2 single crystals
No full textA Y-3(Fe, Cr)(29) single crystal which has a Nd-3(Fe, Ti)(29)-type monoclinic structure has been prepared using the Czochralski method followed by heat treatment of an initial Y-2(Fe, Cr)(17) crystal. The magnetization curves were measured along the easy and hard magnetization directions in the range from 1.5 to 293 K for crystals of Y-3(Fe, Cr)(29) and Y-2(Fe, Cr)(17). The saturation magnetization of Y-3(Fe, Cr)(29) decreases with increasing temperature and is in good agreement with a T-3/2 spin-wave relation law. The magnetic properties of the two crystals are compared. (C) 2002 Elsevier Science B.V. All rights reserved
Análisis comparativo de la acción ofensiva en F-7 y F-8, en la categoría alevín
No full textIn the latest years, it has been considered, within the Spanish Football Federation, the possibility of creating a new league of 8 football�s game instead of 7 football�s game. This article tries to enlighten the subject, as an approximation to the attacking phase of 7 and 8 football�s game in the children category. Within the observational methodology, using contrastive statistics -with the software SPSS, version 15.0-, and with the detection of hidden sequential patterns -with the software Theme 5.0-, the features of the attacking process between both 7 and 8 football categories are compared. No meaningful differences have been found between both modalities, F-7 and F-8, in the observational data acquired, except in the ending phaseEn los últimos años en el seno de la Real Federación Española de Fútbol se ha planteado la posible implantación de la modalidad de fútbol 8 en lugar de fútbol 7. El presente artículo trata de arrojar luz sobre la cuestión, suponiendo una aproximación a la fase ofensiva de las modalidades de fútbol 7 y fútbol 8 en la categoría alevín. En el seno de la metodología observacional, realizando un análisis estadístico -con el software SPSS, versión 15.0.- y mediante la detección de patrones secuenciales ocultos -con el software Theme, versión 5.0.-, se comparan las características del proceso ofensivo entre las modalidades deportivas de fútbol 7 y fútbol 8. En el muestreo observacional realizado no se han encontrado diferencias significativas entre las modalidades de F-7 y F-8, salvo en la fase de finalizació
Shelf-life and its estimation in drug stability studies
No full textOne important property of any drug product is its stability over time. Drug stability studies are routinely carried out in the pharmaceutical industry in order to measure the degradation of an active pharmaceutical ingredient of a drug product. One important study objective is to estimate the shelf-life of the drug; the estimated shelf-life is required by the US Food and Drug Administration to be printed on the package label of the drug. This involves a suitable definition of the true shelf-life and the construction of an appropriate estimate of the true shelf-life. In this paper, the true shelf-life T? is defined as the time point at which 100?% of all the individual dosage units (e.g. tablets) of the drug have the active ingredient content no less than the lowest acceptable limit L, where ? and L are prespecified constants. The value of T? depends on the parameters of the assumed degradation model of the active ingredient content and so is unknown. A lower confidence bound Tˆ? for T? is then provided and used as the estimated shelf-life of the drug
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