7,620 research outputs found

    Anisotropic simplicial minisuperspace model

    Get PDF
    The computation of the simplicial minisuperspace wavefunction in the case of anisotropic universes with a scalar matter field predicts the existence of a large classical Lorentzian universe like our own at late timesComment: 19 pages, Latex, 6 figure

    Simplicial minisuperspace models in the presence of a massive scalar field with arbitrary scalar coupling

    Get PDF
    We extend previous simplicial minisuperspace models to account for arbitrary scalar coupling \eta R\phi^2.Comment: 24 pages and 9 figures. Accepted for publication by Classical and Quantum Gravit

    Project MARIE: presentation and stage of development

    Get PDF
    Project MARIE - Mediterranean Building Rethinking for Energy Efficiency Improvement is an international strategic project from the European Union in the scope of the MED Program. The project aims to promote building energy efficiency in the Mediterranean region and overcome the mains barriers to large scale improvement trough the development of a common strategy adaptable to each country/region specifications, in the framework of European Union building energy efficiency policies. This article presents a description of the Project MARIE, its stage of development, and also the results achieved in the first third of the project

    Proposta de nova metodologia para o cálculo do fator de sombreamento de vãos envidraçados por elementos horizontais

    Get PDF
    O comportamento térmico dos edifícios depende, em larga medida, dos ganhos solares verificados através dos vãos envidraçados. Devem os ganhos solares ser otimizados, isto é, durante a estação de aquecimento, os ganhos solares úteis devem ser maximizados e, durante a estação de arrefecimento, as cargas térmicas devidas aos ganhos solares devem ser minimizadas. Os dispositivos de sombreamento dos vãos envidraçados, devem, tanto quanto possível, provocar o sombreamento dos vãos, durante a estação de arrefecimento e, na medida do possível, não o provocar durante a estação de aquecimento. As palas horizontais para sombreamento de vãos envidraçados são particularmente adequadas a vãos orientados a sul. As palas devem ser dimensionadas de forma a, tanto quanto possível, provocarem o sombreamento dos vãos envidraçados durante a estação de arrefecimento sem que tal aconteça durante a estação de aquecimento. No entanto, verifica-se que, de uma forma geral, segundo a metodologia de cálculo prevista pelo Regulamento das Caraterísticas de Comportamento Térmico dos Edifícios (RCCTE), a existência de palas horizontais de sombreamento é penalizadora da eficiência energética dos edifícios. Com a presente comunicação, é apresentada uma nova metodologia de cálculo do factor de sombreamento por elementos horizontais. Através desta metodologia, desde que as palas horizontais sejam adequadamente dimensionadas, a sua existência originará necessidades nominais globais de energia primária de um edifício (Ntc) com um valor inferior ao que se obteria se não existissem as referidas palas. Consequentemente, a introdução de palas de sombreamento convenientemente dimensionadas contribuirá para a obtenção de uma mais elevada classe de eficiência energética do edifício

    Insulin Resistance and Atherosclerosis

    Get PDF
    O tipo de vida nas sociedades ocidentais favorece, nos indivíduos geneticamente predispostos, o desenvolvimento do estado de insulino-resistência. Neste estado, são necessárias concentrações de insulina mais elevadas para que se obtenha uma normal resposta metabólica nos tecidos-alvo, ocasionando o desenvolvimento de hiperinsulinismo. Em consequência da multiplicidade de acções da insulina, a insulino-resistência está associada a disfunção de vários tecidos,orgãos e sistemas (Síndrome X), tendo por consequência, entre outras, um aumento do risco de patologia vascular aterosclerótica. Neste artigo, são revistas as alterações a nível do controlo da pressão arterial, endotélio vascular, metabolismo lipídico e sistema fibrinolítico, consequentes ao estado de insulino resistência e a forma como, junto com o hiperinsulinismo, aceleram o processo da aterogénese. São, igualmente, abordadas algumas das armas terapêuticas capazes de combater aquele estado e, assim, reduzir a morbilidade e mortalidade associadas à aterosclerose

    Effects of fertiliser practices on the growth and quality of two table grape cultivars: 'Cardinal' and 'D. Maria'.

    Get PDF
    In this study, the different fertilliser practices of four commercial vineyards (Vitis vinifera L. cv. 'Cardinal' and cv. 'D. Maria') in southern Portugal were assessed and compared in 2002. The vineyards were established in similar soils under the same climatic conditions and additional water was supplied by drip irrigation. At harvest, the mineral composition of petioles (P, K, Mg, Ca, Fe, Cu, Zn and Mn) and quality parameters of the grapes (total soluble solids expressed as degree Brix, cluster length and weight, number of grapes, grapes weight and rachis weight) were recorded. For the 'Cardinal' cultivar, the nutritional status of the plant was correlated with growth and yield, and the greatest values for most of the parameters studied were measured at Alvisquer farm. For the 'D. Maria' cultivar, a single correlation was found between nutrient levels and growth. Shoot and cluster lengths, and grape weight were similar at all farms, though cluster weight, number of grapes and total soluble solids were smaller at Pedras than at Alvisquer or Gomeira

    Comportamento acústico de salas para o ensino musical no Algarve. A perspetiva dos professores

    Get PDF
    Rooms for music education have specific requirements, in particular, from the point of view of its acoustic behavior. However, Regulation of Acoustic Requirements of Buildings establishes requirements for school buildings but does not consider the specificity of music schools buildings. Furthermore, there are music schools in buildings that were not constructed for such purpose and it is necessary to rehabilitate acoustically these buildings. The present communication aims to present the diagnosis of specific problems in buildings for music education in Algarve and it is presented the point of view of their teachers. The aim is thus to contribute to solving these problems. Thus we want to contribute to improve the teaching-learning process in existing music schools and simultaneously to contribute to avoid the repetition of problematic situations in the future

    Study of historical value mortars

    Get PDF
    "First International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2019)"The rehabilitation of buildings, or historic landmarks, has gained in importance over the years. It is increasingly important to safeguard the cultural identity and history of a country. In this research the mortars of the Roman city of Conimbriga were studied, being one of the oldest archaeological cities in Portugal. Conímbriga has its origin in a Celtic Castro of the tribe of the Conii, at the end of the Iron Age. It was occupied by the Romans from 139 BC. It was under the Emperor Augustus Empire, in the second century AD, that the city achieved its splendor, having then been built public baths and a Forum. With the decline of the Empire, in the late fourth century, a monumental defensive wall was erected, which did not prevent the assault of the city by the Suevi, in 468, and the consequent decline of the city. Large excavations carried out throughout the 20th century revealed a valuable and complex set of buildings, including thermal baths, an aqueduct that runs more than 3,400 meters from the source, and remains of a Christian basilica, probably from the 6th century. In this type of rehabilitation works the use of mortars was predominant, hence the importance of their study to know how they behave. In order for a rehabilitation intervention to be successful it is necessary to know the existing support in place to guarantee the compatibility of the materials. It was necessary to go ?in situ? to collect the samples with the proper authorization of the Museum of Conimbriga. These mortar samples were analyzed and characterized by scanning electron microscopy (SEM) for further analysis. The composition of the samples will allow to adjust dosages and to choose a restoration mortar, as close as possible, to the one that was collected in order to preserve the maximum historical identity of the place.(undefined

    Prospective community-based study of stroke in Northern Portugal: incidence and case fatality in rural and urban populations

    Get PDF
    Background and Purpose—Mortality statistics indicate that Portugal has the highest stroke mortality in Western Europe. Data on stroke incidence in Northern Portugal, the region with the highest mortality, are lacking. This study was designed to determine stroke incidence and case fatality in rural and urban populations in Northern Portugal. Methods—All suspected first-ever-in-a-lifetime strokes occurring between October 1998 and September 2000 in 37 290 residents in rural municipalities and 86 023 living in the city of Porto were entered in a population-based registry. Standard definitions and comprehensive sources of information were used for identification of patients who were followed-up at 3 and 12 months after onset of symptoms. Results—During a 24-month period, 688 patients with a first-ever stroke were registered, 226 in rural and 462 in urban areas. The crude annual incidence was 3.05 (95% CI, 2.65 to 3.44) and 2.69 per 1000 (95% CI, 2.44 to 2.93) for rural and urban populations, respectively; the corresponding rates adjusted to the European standard population were 2.02 (95% CI, 1.69 to 2.34) and 1.73 (95% CI, 1.53 to 1.92). Age-specific incidence followed different patterns in rural and urban populations, reaching major discrepancy for those 75 to 84 years old, 20.2 (95% CI, 16.1 to 25.0) and 10.9 (95% CI, 9.0 to 12.8), respectively. Case fatality at 28 days was 14.6% (95% CI, 10.2 to 19.3) in rural and 16.9% (95% CI, 13.7 to 20.6) in urban areas. Conclusions—Stroke incidence in rural and urban Northern Portugal is high compared to that reported in other Western Europe regions. The high official mortality in our country, which could be explained by a relatively high incidence, was not because of a high case fatality rate

    Breast skin-line detection using dynamic programming

    Get PDF
    In this paper, we present a novel method to extract the breast skin-line based on dynamic programming. Skin-line extraction is an important preprocessing step in CAD systems; however, it is a challenging problem due to the presence of noise, underexposed regions, which results in a low contrast area near the skin-air interface, and artifacts such as labels. Our proposal utilizes the stroma edge to constrain searching for the border. In order to cope with noise, we consider several candidate points for the border interface which are obtained by the Laplace operator applied in pre-defined directions in the mammogram. The breast contour is obtained from the candidate points using a dynamic programming algorithm. This utilizes a criterion of optimality to obtain the optimum contour by minimization of a cost function. The method was evaluated using 82 mammograms whose contour were manually extracted by a radiologist from the mini- MIAS database. The Polyline Distance Measure was evaluated for each contour selected with the proposed method, obtaining a mean error of 2.05 pixels and a standard deviation of 0.80.Fundação para a Ciência e a Tecnologia (FCT
    corecore