2,016 research outputs found

    Development of an open-source platform for calculating losses from earthquakes

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    Risk analysis has a critical role in the reduction of casualties and damages due to earthquakes. Recognition of this relation has led to a rapid rise in demand for accurate, reliable and flexible risk assessment numerical tools and software. As a response to this need, the Global Earthquake Model (GEM) started the development of an open source platform called OpenQuake, for calculating seismic hazard and risk at different scales. Along with this framework, also several other tools to support users creating their own models and visualizing their results are currently being developed, and will be made available as a Modelers Tool Kit (MTK). In this paper, a description of the architecture of OpenQuake is provided, highlighting the current data model, workflow of the calculators and the main challenges raised when running this type of calculations in a global scale. In addition, a case study is presented using the Marmara Region (Turkey) for the calculations, in which the losses for a single event are estimated, as well as probabilistic risk for a 50 years time span

    Developing a global risk engine

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    Risk analysis is a critical link in the reduction of casualties and damages due to earthquakes. Recognition of this relation has led to a rapid rise in demand for accurate, reliable and flexible risk assessment software. However, there is a significant disparity between the high quality scientific data developed by researchers and the availability of versatile, open and user-friendly risk analysis tools to meet the demands of end-users. In the past few years several open-source software have been developed that play an important role in the seismic research, such as OpenSHA and OpenSEES. There is however still a gap when it comes to open-source risk assessment tools and software. In order to fill this gap, the Global Earthquake Model (GEM) has been created. GEM is an internationally sanctioned program initiated by the OECD that aims to build independent, open standards to calculate and communicate earthquake risk around the world. This initiative started with a one-year pilot project named GEM1, during which an evaluation of a number of existing risk software was carried out. After a critical review of the results it was concluded that none of the software were adequate for GEM requirements and therefore, a new object-oriented tool was to be developed. This paper presents a summary of some of the most well known applications used in risk analysis, highlighting the main aspects that were considered for the development of this risk platform. The research that was carried out in order to gather all of the necessary information to build this tool was distributed in four different areas: information technology approach, seismic hazard resources, vulnerability assessment methodologies and sources of exposure data. The main aspects and findings for each of these areas will be presented as well as how these features were incorporated in the up-to-date risk engine. Currently, the risk engine is capable of predicting human or economical losses worldwide considering both deterministic and probabilistic-based events, using vulnerability curves. A first version of GEM will become available at the end of 2013. Until then the risk engine will continue to be developed by a growing community of developers, using a dedicated open-source platform

    Membrane processing of grape must for control of the alcohol content in fermented beverages

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    The great demand of beverages, both alcohol-free and with low alcohol content, is a great challenge for the production of beverages with controlled alcohol content through the use of sustainable enological practices. The present work addresses this challenge with the processing of grape must by reverse osmosis (RO) for must reconstitution with different sugar contents prior to the alcoholic fermentation. The original must came from grapes grown in Quinta do Quinto, in Santarém, collected after destemming and mechanic crushing, and preserved in a refrigerated chamber at -1.6 °C until processing by RO. The RO processing was carried out in Escola Superior Agrária de Santarém, with a pilot plant equipped with RO spiral wound modules, M38RO, from Alfa Laval, Denmark. The total membrane permeation area is 15 m2. The work pressure was 55 bar. The original must had 23.7 oBrix, a density of 1108 g.L-1, 15.2% (v/v) of probable alcohol, and a conductivity of 2.01 mS.cm-1. The must reconstitution was carried out, by mixing the concentrated grape must with the vegetal water produced by RO (permeate) to obtain beverages with a nominal alcohol content of 5%, 7%, 10% and 13% (v/v). The fermentation average temperature was between 18.2 and 19.7 °C, and the final density rounded about 993 g.cm-3. The beverages were analysed by different parameters, including total polyphenols, total anthocyanins, colour intensity and hue, the coordinates CIELab, alcohol content, total acidity, volatile acidity, pH, free SO2 and total SO2. The attributes of the beverage, corresponding to the visual appearance, aroma and taste senses, as well as the overall judgment were evaluated by the tasters. The proposed method can produce beverages with controlled low alcohol content. The decrease of the alcohol content led to lower content of polyphenols compounds which influenced the sensory evaluation.info:eu-repo/semantics/publishedVersio

    Evaluation of analytical methodologies to derive vulnerability functions

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    The recognition of fragility functions as a fundamental tool in seismic risk assessment has led to the development of more and more complex and elaborate procedures for their computation. Although vulnerability functions have been traditionally produced using observed damage and loss data, more recent studies propose the employment of analytical methodologies as a way to overcome the frequent lack of post-earthquake data. The variation of the structural modelling approaches on the estimation of building capacity has been the target of many studies in the past, however, its influence in the resulting vulnerability model, impact in loss estimations or propagation of the uncertainty to the seismic risk calculations has so far been the object of restricted scrutiny. Hence, in this paper, an extensive study of static and dynamic procedures for estimating the nonlinear response of buildings has been carried out in order to evaluate the impact of the chosen methodology on the resulting vulnerability and risk outputs. Moreover, the computational effort and numerical stability provided by each approach were evaluated and conclusions were obtained regarding which one offers the optimal balance between accuracy and complexity

    Interceptive orthodontic traction of impacted maxillary incisors: Clinical cases

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    Impaction is a tooth’s partial or total lack of eruption once the normal age for eruption has passed. It has a multifactorial etiology, and the most common factors are trauma, supernumerary teeth, and odontomas. In particular, the absence of a maxillary central incisor (MCI) due to impaction can pose several consequences for a person’s facial aesthetics, chewing ability, and phonetics, thereby making the diagnosis and early treatment of MCI impaction are imperative. A primary approach to such treatment involves surgical exposure, orthodontic space opening, and the posterior traction of the incisor to its normal position, all of which benefits tooth maintenance and possibly even alveolar bone maintenance. As a contribution to clarifying those benefits, this article analyzes three clinical cases of individuals with impacted MCIs due to different causes—supernumerary teeth, root dilaceration, and eruption deviation—all of whom were submitted to treatment emphasizing orthodontic traction

    Coleta de folhas do cafeeiro e extração de DNA genômico de alta qualidade.

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    Para a amplificação do DNA in vitro, é necessário que o DNA genômico seja de boa qualidade. É comum que seja realizada a coleta do tecido vegetal em local distante de onde será feita a extração e análises do DNA e muitas vezes, o armazenamento inadequado das amostras favorece as reações de oxidação, resultando na redução da qualidade deste. Realizou-se este trabalho com o objetivo de estabelecer um método simples e eficiente para coleta e armazenamento de folhas de Coffea arabica visando a obtenção de DNA de boa qualidade. O trabalho foi realizado no Laboratório de Análise de Sementes da Universidade Federal de Lavras, envolvendo doze tratamentos e duas testemunhas. Foram combinados os fatores umidade da folha (seca ou úmida) x tempo de armazenamento (24h e 48h) x condição do ambiente (TºC ambiente ou 4ºC) x utilização de sílica no recipiente de armazenamento da folha (com ou sem sílica). Foram utilizados dois controles, onde as folhas coletadas foram armazenadas no campo em gelo ou em N2 líquido e submetidas à extração do DNA logo após a sua coleta. A avaliação da qualidade do DNA foi feita pela eletroforese do DNA genômico em gel de agarose 0,7% e pela amplificação de fragmentos de DNA utilizando-se um par de primer microssatélite. Os resultados indicaram que a utilização da sílica quando as folhas estavam secas e o armazenamento das folhas a 4ºC por 24h ou 48 h são favoráveis à oxidação das amostras, resultando em um DNA de má qualidade. A extração do DNA de alta qualidade passível de ser utilizado em PCR é viável quando folhas secas ou úmidas são coletadas e armazenadas em sacos plásticos por até 48 horas antes do início do procedimento da extração

    A non inflationary model with scale invariant cosmological perturbations

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    We show that a contracting universe which bounces due to quantum cosmological effects and connects to the hot big-bang expansion phase, can produce an almost scale invariant spectrum of perturbations provided the perturbations are produced during an almost matter dominated era in the contraction phase. This is achieved using Bohmian solutions of the canonical Wheeler-de Witt equation, thus treating both the background and the perturbations in a fully quantum manner. We find a very slightly blue spectrum (nS1>0n_{_\mathrm{S}}-1>0). Taking into account the spectral index constraint as well as the CMB normalization measure yields an equation of state that should be less than ω8×104\omega\lesssim 8\times 10^{-4}, implying nS1O(104)n_{_\mathrm{S}}-1 \sim \mathcal{O}(10^{-4}), and that the characteristic size of the Universe at the bounce is L0103PlanckL_0 \sim 10^3 \ell_\mathrm{Planck}, a region where one expects that the Wheeler-DeWitt equation should be valid without being spoiled by string or loop quantum gravity effects.Comment: 9 pages, 4 figure

    A mathematical framework for reducing the domain in the mechanical analysis of periodic structures

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    A theoretical framework is developped leading to a sound derivation of Periodic Boundary Conditions (PBCs) for the analysis of domains smaller then the Unit Cells (UCs), named reduced Unit Cells (rUCs), by exploiting non-orthogonal translations and symmetries. A particular type of UCs, Offset-reduced Unit Cells (OrUCs) are highlighted. These enable the reduction of the analysis domain of the traditionally defined UCs without any loading restriction. The relevance of the framework and its application to any periodic structure is illustrated through two practical examples: 3D woven and honeycomb.Comment: 18 page

    Superoxide reductase from Giardia intestinalis: structural characterization of the first sor from a eukaryotic organism shows an iron centre that is highly sensitive to photoreduction

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    Superoxide reductase (SOR), which is commonly found in prokaryotic organisms, affords protection from oxidative stress by reducing the superoxide anion to hydrogen peroxide. The reaction is catalyzed at the iron centre, which is highly conserved among the prokaryotic SORs structurally characterized to date. Reported here is the first structure of an SOR from a eukaryotic organism, the protozoan parasite Giardia intestinalis (GiSOR), which was solved at 2.0 Å resolution. By collecting several diffraction data sets at 100 K from the same flash-cooled protein crystal using synchrotron X-ray radiation, photoreduction of the iron centre was observed. Reduction was monitored using an online UV-visible microspectrophotometer, following the decay of the 647 nm absorption band characteristic of the iron site in the glutamate-bound, oxidized state. Similarly to other 1Fe-SORs structurally characterized to date, the enzyme displays a tetrameric quaternary-structure arrangement. As a distinctive feature, the N-terminal loop of the protein, containing the characteristic EKHxP motif, revealed an unusually high flexibility regardless of the iron redox state. At variance with previous evidence collected by X-ray crystallography and Fourier transform infrared spectroscopy of prokaryotic SORs, iron reduction did not lead to dissociation of glutamate from the catalytic metal or other structural changes; however, the glutamate ligand underwent X-ray-induced chemical changes, revealing high sensitivity of the GiSOR active site to X-ray radiation damage
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