285 research outputs found

    Development of prefabricated retrofit module towards nearly zero energy buildings

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    The building sector is an energy intensive sector, with great potential to reduce energy needs and environmental pollution. Several measures are being taken to increase the energy efficiency and avoid energy consumption in this sector. A recent trend is the nearly zero energy buildings, which was already adopted by some of the latest regulations, such as the 2010 recast of the European Performance of Buildings Directive (EPBD). However, to reach these goals, especially considering the existing building stock, new retrofit solutions are required, which must be well adapted to the specific building stock needs, and ensure that the building retrofit can achieve the nearly zero energy buildings standards. This paper presents a new prefabricated retrofit module solution for the facades of existing buildings, and also the steps taken to optimise its performance, which includes a judicious choice of materials, 3D modelling, cost–benefit analysis, use of different simulation tools for performance optimisation and prototyping. It is also shown the implementation of the retrofit module within an integrated retrofit approach, whose final goal was to obtain a building with the minimum possible energy consumption and greenhouse gas emissions.This work was supported by ERDF funds through the Competitiveness Factors Operational Programme - COMPETE and National Funds through FCT - Foundation for Science and Technology [project number FCOMP-01-0124-FEDER-007189]. The author, Pedro Silva, was supported by FCT and DST, S.A. [grant number SFRH/BDE/15599/2006], which was co-financed by the Human Potential Operational Programme of the European Union POPH - NSRF - Type 4.1 - Advanced Training, shared by the European Social Fund and national funds MCTES

    Nets desempenham papel importante nas doenças crÎnicas: uma revisão de literatura

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    Introduction: Neutrophil extracellular traps (NETs) are the result of extrusion of various components by neutrophils, and act to eradicate the pathogens present, as well as providing mechanical barrier, thus preventing the spread of microorganisms. Chronic diseases have been found to have a significant influence on these NETs, which by specific mechanisms produce negative effects on pathogenesis. Methods: Bibliographic review using Google Scholar, Medline, Center for Biotechnology Information (PubMed) and Scientific Electronic Library Online (SciELO) as databases. The search was performed in articles published from 2000 to 2019, in Portuguese and/or English languages. Development: It was evidenced that each disease in question is aggravated by NETs in a different way, either by inflammatory exacerbation or physical barrier, and the participation of pathogens in the neutrophil stimulation inducing process can be considered. Conclusion: Understanding the process of formation of NETs, ie, NETose, may help future findings that could contribute to mitigate the injury caused by the neutrophil mechanism, which involves multiple cytokines, granules and DNA molecules.extrusĂŁo de diversos componentes pelos neutrĂłfilos, e agem com o intuito de erradicar os patĂłgenos presentes, alĂ©m de propiciar barreira mecĂąnica, evitando assim, a disseminação de microrganismos. Foi descoberto que doenças crĂŽnicas possuem influĂȘncia significativa dessas NETs, que por mecanismos especĂ­ficos, produzem efeitos negativos sobre a patogĂȘnese. MĂ©todos: RevisĂŁo bibliogrĂĄfica utilizando como bases de dados o Google acadĂȘmico, Medline, Center for Biotechnology Information (PubMed) e na biblioteca eletrĂŽnica Scientific Eletronic Library Online (SciELO). A busca foi realizada em artigos publicados no perĂ­odo de 2000 a 2019 em portuguĂȘs e/ou inglĂȘs. Desenvolvimento: Foi evidenciado que cada doença em questĂŁo Ă© agravada pelas NETs de uma maneira distinta, seja pela exacerbação inflamatĂłria ou pela barreira fĂ­sica, e ainda pode-se considerar a participação de patĂłgenos no processo indutor de estimulação dos neutrĂłfilos. ConclusĂŁo: O entendimento do processo de formação das NETs, ou seja, a NETose, pode auxiliar em futuros achados que poderiam contribuir para amenizar a injĂșria causada pelo mecanismo dos neutrĂłfilos, que envolve mĂșltiplas citocinas, grĂąnulos e molĂ©culas de DNA

    Propriedades de ZrO2 (Y2 O3) reciclado proveniente da confecção de próteses dentårias

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    RESUMO O objetivo deste trabalho foi a recuperação de descartes de ZrO2(Y2O3) oriundos de laboratĂłrios de prĂłteses dentĂĄrias, a partir do seu reprocessamento. Os descartes de ZrO2(Y2O3) foram fragmentados, peneirados e calcinados a 900ÂșC. PĂłs com tamanho menor que 32μm foram prensados uniaxialmente a 100MPa e sinterizados em temperaturas entre 1400 e 1600ÂșC-120min. AnĂĄlise de difração de raios X realizadas nos materiais calcinados indicaram a presença majoritĂĄria da fase ZrO2 tetragonal. Os compactos apresentaram densidade a verde prĂłximo a 47% e as amostras sinterizadas tiveram sua densidade relativa variando entre 83,5% e 95%, para temperaturas de sinterização de 1400 e 1600ÂșC, respectivamente. Os resultados da anĂĄlise de difração de raios X indicaram a presença da fase ZrO2 tetragonal, com dureza Vickers e tenacidade mĂĄxima obtidos para as amostras sinterizadas a 1600ÂșC, da ordem de 1100 HV e 5,7 MPa.m1/2 respectivamente

    Operation and performance of the ATLAS semiconductor tracker

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    The semiconductor tracker is a silicon microstrip detector forming part of the inner tracking system of the ATLAS experiment at the LHC. The operation and performance of the semiconductor tracker during the first years of LHC running are described. More than 99% of the detector modules were operational during this period, with an average intrinsic hit efficiency of (99.74±0.04)%. The evolution of the noise occupancy is discussed, and measurements of the Lorentz angle, Ύ-ray production and energy loss presented. The alignment of the detector is found to be stable at the few-micron level over long periods of time. Radiation damage measurements, which include the evolution of detector leakage currents, are found to be consistent with predictions and are used in the verification of radiation background simulations

    Search for H→γγ produced in association with top quarks and constraints on the Yukawa coupling between the top quark and the Higgs boson using data taken at 7 TeV and 8 TeV with the ATLAS detector

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    A search is performed for Higgs bosons produced in association with top quarks using the diphoton decay mode of the Higgs boson. Selection requirements are optimized separately for leptonic and fully hadronic final states from the top quark decays. The dataset used corresponds to an integrated luminosity of 4.5 fb−14.5 fb−1 of proton–proton collisions at a center-of-mass energy of 7 TeV and 20.3 fb−1 at 8 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. No significant excess over the background prediction is observed and upper limits are set on the tt¯H production cross section. The observed exclusion upper limit at 95% confidence level is 6.7 times the predicted Standard Model cross section value. In addition, limits are set on the strength of the Yukawa coupling between the top quark and the Higgs boson, taking into account the dependence of the tt¯H and tH cross sections as well as the H→γγ branching fraction on the Yukawa coupling. Lower and upper limits at 95% confidence level are set at −1.3 and +8.0 times the Yukawa coupling strength in the Standard Model

    Measurement of the correlation between flow harmonics of different order in lead-lead collisions at √sNN = 2.76 TeV with the ATLAS detector

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    Correlations between the elliptic or triangular flow coefficients vm (m=2 or 3) and other flow harmonics vn (n=2 to 5) are measured using √sNN=2.76 TeV Pb+Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 7 ÎŒb−1. The vm−vn correlations are measured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v3 is found to be anticorrelated with v2 and this anticorrelation is consistent with similar anticorrelations between the corresponding eccentricities, Δ2 and Δ3. However, it is observed that v4 increases strongly with v2, and v5 increases strongly with both v2 and v3. The trend and strength of the vm−vn correlations for n=4 and 5 are found to disagree with Δm−Δn correlations predicted by initial-geometry models. Instead, these correlations are found to be consistent with the combined effects of a linear contribution to vn and a nonlinear term that is a function of v22 or of v2v3, as predicted by hydrodynamic models. A simple two-component fit is used to separate these two contributions. The extracted linear and nonlinear contributions to v4 and v5 are found to be consistent with previously measured event-plane correlations

    Measurement of the cross section of high transverse momentum Z→bb̄ production in proton–proton collisions at √s = 8 TeV with the ATLAS detector

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    This Letter reports the observation of a high transverse momentum Z→bb̄ signal in proton–proton collisions at √s=8 TeV and the measurement of its production cross section. The data analysed were collected in 2012 with the ATLAS detector at the LHC and correspond to an integrated luminosity of 19.5 fb−Âč. The Z→bb̄ decay is reconstructed from a pair of b -tagged jets, clustered with the anti-ktkt jet algorithm with R=0.4R=0.4, that have low angular separation and form a dijet with pT>200 GeVpT>200 GeV. The signal yield is extracted from a fit to the dijet invariant mass distribution, with the dominant, multi-jet background mass shape estimated by employing a fully data-driven technique that reduces the dependence of the analysis on simulation. The fiducial cross section is determined to be σZ→bbÂŻfid=2.02±0.20 (stat.) ±0.25 (syst.)±0.06 (lumi.) pb=2.02±0.33 pb, in good agreement with next-to-leading-order theoretical predictions
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