9,454 research outputs found

    Evaluation of strengthening techniques of traditional masonry buildings: case study of a four-building aggregate

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    Increasing appraisal of the durability, conservation state, and changeable use and function of old buildings in urban centers relies a great deal on the structural safety evaluation of vertical load capacity and the ability to resist horizontal forces. The need to assess seismic vulnerability, particularly of traditional masonry buildings, is a key issue. Evaluation of the seismic vulnerability of old buildings is essential in the definition of strengthening needs and minimization of damage from seismic actions in the safeguarding of built heritage. A three-dimensional model was developed for an aggregate of four traditional masonry buildings located in the old city center of Coimbra, in Portugal. The finite element modeling of these buildings has aimed to identify structural fragility, understand the damages detected, and evaluate the global structural safety of these types of buildings. The primary results obtained in this case study helped to interpret the structural damage and stress distribution, and verified global stability and its consequences. Different strengthening techniques to improve the global behavior of these buildings were modeled and analyzed. A comparison of the efficiencies of strengthening strategies is also discussed. DOI: 10.1061/(ASCE)CF.1943-5509.0000164. (C) 2011 American Society of Civil Engineers

    A data-driven approach for the definition of metropolitan regions

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    The objective of this paper is to present a data-driven approach for the definition of metropolitan regions. The proposed approach, which constitutes an option to avoid the endless confrontations that may be derived from the essentially subjective political criteria, explores two branches of Spatial Analyses: Spatial Statistics and Spatial Modeling. Spatial Statistics tools are used to identify the characteristics of local association and combined with Cellular Automata techniques in order to build prediction models. The analyses conducted with Exploratory Spatial Data Analyses (ESDA) tools and census data give a clear indication of clusters of zones with similar characteristics, which can be seen as uniform regions. Spatial dynamic models can then be used to foresee the global behavior of regions in terms of growth, although based on local (and historical) relationships among zones. The proposed approach is tested in a case study carried out in Portugal, where this is a timely issue

    The Left-Right SU(3)(L)xSU(3)(R)xU(1)(X) Model with Light, keV and Heavy Neutrinos

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    We construct a full left-right model for the electroweak interactions based on the SU(3)L⊗SU(3)R⊗U(1)XSU(3)_{L}\otimes SU(3)_{R}\otimes U(1)_{X} gauge symmetry. The fermion content of the model is such that anomaly cancellation restricts the number of families to be a multiple of three. One of the most important features of the model is the joint presence of three light active neutrinos, three additional neutrinos at keV mass scale, and six heavy ones with masses around\textbf{101110^{11}} GeV. They form a well-motivated part of the spectrum in the sense they address challenging problems related to neutrino oscillation, warm dark matter, and baryogenesis through leptogenesis.Comment: 11 pages. Small corrections and typos fixed. Accepted for publication in PR

    A spatial analysis approach for the definition of metropolitan regions : the case of Portugal

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    The objective of this paper is to present a combined, two-step spatial analysis approach for the definition of metropolitan regions. The proposed approach, which constitutes an option to avoid the endless confrontations that may be derived from the essentially subjective political criteria, explores two branches of spatial analysis: spatial statistics and spatial modelling. Spatial statistics tools are used to identify the characteristics of local association and are combined with a neural network in order to build prediction models. The analyses conducted with exploratory spatial data analysis tools and census data give a clear indication of clusters of zones with similar characteristics, which can be seen as uniform regions. Spatial models can then be used to foresee the global behaviour of regions in terms of growth, albeit the basis of local (and historical) relationships among zones. The proposed approach is tested in a case study carried out in Portugal, where this is a timely issue

    Análise fisiográfica das várzeas do Baixo Tocantins: uma contribuição ao manejo e desenvolvimento dos sistemas de uso da terra.

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    Análise fisiográfica e a evolução das várzeas do Baixo Tocantins; Fisiologia fluvial; Adequação e limitações ambientais impostas aos subsistemas.bitstream/item/63563/1/Oriental-Doc149.PD

    Sistema especialista para aplicação do composto de lixo urbano na agricultura.

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    Composto de lixo urbano. Compostagem. Grau de maturação do composto. Composto de lixo como adubo e corretivo do solo. Coleta seletiva de lixo. Metais pesados. Contaminação por patógeno. Sistemas especialistas. Aplicação deste sistema especialista.bitstream/CNPTIA/9947/1/doc22.pdfAcesso em: 29 maio 2008
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