1,036 research outputs found

    Energy efficiency of social housing existing buildings – a portuguese case study

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    The European energy performance building regulations, Directive 2002/91/EC - Energy Performance of Buildings Directive (EPBD) of the European Parliament and Council, require that new buildings present minimum standards of energy efficiency. Accordingly the Portuguese regulations require that new buildings comply with minimum requirements on the energy performance and must have an energy performance certification through witch an energy efficiency label is attributed to the housing. It also require that existing buildings must have an efficiency energy label when submitted to a commercial transaction or to a deep rehabilitation. To achieve this goal the study of energy performance of existing buildings must be done. As many essentials elements to determine the U-factor and other thermal parameters are unknown, Portugal developed a simplified methodology to achieve the thermal performance of existing buildings. The aim of this paper is to present the study of the energy performance of a set of social dwellings that were constructed during the decade of 80, constructed before the former building thermal comfort specifications came into force. During the study the referred methodology was applied and conclusions of the energy efficiency label obtained were put out as the encountered difficulties. The study also compares the results obtained by the simplified methodology and by the detailed methodology that is required by Portuguese building thermal comfort specifications

    Evaluation of biomass and coal co-gasification of brazilian feedstock using a chemical equilibrium model

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    Coal and biomass are energy sources with great potential for use in Brazil. Coal-biomass cogasification enables the combination of the positive characteristics of each fuel, besides leading to a cleaner use of coal. The present study evaluates the potential of co-gasification of binary coal-biomass blends using sources widely available in Brazil. This analysis employs computational simulations using a reliable thermodynamic equilibrium model. Favorable operational conditions at high temperatures are determined in order to obtain gaseous products suitable for energy cogeneration and chemical synthesis. This study shows that blends with biomass ratios of 5% and equivalence ratios ≤ 0.3 lead to high cold gas efficiencies. Suitable gaseous products for chemical synthesis were identified at biomass ratios ≤ 35% and moisture contents ≥ 40%. Formation of undesirable nitrogen and sulfur compounds was also analyzed

    Estudo morfoquantitativo do plexo submucoso (de Meissner) do jejuno-íleo de cobaias jovens e velhas

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    OBJECTIVE: To study the aging of submucous plexus of the small intestine (jejunum-ileum) of the guinea pigs from the quantitative, structural and ultrastructural perspective. METHOD: Chemical preparations of membrane of the jejunum-ileum of old and young animals with the use of light and electronic microscope. RESULTS: The ganglia of young animals presented between 1 and 56 neurons and the old animals presented from 1 to 30 neurons. The mean density of the ganglia by cm² in the young jejunum-ileum was of 551±36.89 and in the old one 413±11.86. The density of the neurons was 5011±291.11 neurons/cm² average in young animals and 2918±120.70 neurons/cm² in the old ones. The size of the neurons varied in both age groups. The collagen fibers in the ganglia of old animals they were condensed. Degenerated mitochondrias in the interior of the cell were frequent in the old animals. CONCLUSION: In submucous plexus of the jejunum-ileum there is a loss of 38% of the neurons with aging.OBJETIVO: Estudar o envelhecimento do plexo submucoso do intestino delgado (jejuno-íleo) das cobaias do ponto de vista quantitativo, estrutural e ultra-estrutural. MÉTODO: Preparados de membrana do jejuno-íleo de animais jovens e velhos com a utilização de microscopia de luz e eletrônica. RESULTADOS: Os gânglios de animais jovens apresentaram entre 1 e 56 neurônios e os animais velhos apresentaram de 1 a 30 neurônios. A densidade média dos gânglios por cm² no jejuno-íleo jovem foi de 551±36,89 e no velho foi de 413±11,86. A densidade dos neurônios foi de 5011±291,11 neurônios/cm² em média nos animais jovens e 2918±120,70 neurônios/cm² nos velhos. O tamanho dos neurônios variou em ambos os grupos etários. As fibras colágenas nos gânglios de animais velhos estavam mais condensadas. Mitocôndrias degeneradas no interior da célula foram freqüentes nos animais velhos. CONCLUSÃO: No plexo submucoso do jejuno-íleo há uma perda de 38% dos neurônios com o envelhecimento

    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

    Seismic vulnerability assessment of existing reinforced concrete buildings in urban centers

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    Despite the recent advances in the analysis of the seismic performance of reinforced concrete structures, the assessment of large building inventories aimed at defining and prioritizing structural retrofitting strategies is still a technically challenging task. This paper aims to contribute to bridging this gap by presenting a simplified methodology for assessing the seismic vulnerability of reinforced concrete buildings, which is then applied to a group of 91 buildings affected by recent earthquakes with different macroseismic intensities. The presented methodology is based on the evaluation of eight parameters associated with different factors that affect the seismic response of the building, namely its structural features, foundation conditions, and position within the urban mesh. The formulation of each parameter and the relative weight attributed to each one of them were defined on the basis of post-earthquake damage observation and expert opinion. After defined, the proposed methodology is applied to Faro city center. Based on the results obtained, a cost benefit analysis is made considering a strengthening solution to the buildings with soft-story irregularity

    Effect of sub-lethal chemical disinfection on the biofilm forming ability, resistance to antibiotics and expression of virulence genes of Salmonella Enteritidis biofilm-surviving cells

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    Although disinfection procedures are widely implemented in food environments, bacteria can survive and present increased virulence/resistance. Since little is known about these phenomena regarding biofilms, this study aimed to investigate the effect of chemical disinfection on biofilm-derived cells of Salmonella Enteritidis. Using a reference strain (NCTC 13349) and a food isolate (350), biofilm susceptibility to benzalkonium chloride (BAC), sodium hypochlorite (SH) and hydrogen peroxide (HP) was evaluated and biofilms were exposed to sub-lethal concentrations of each disinfectant. Biofilm-derived cells were characterized for their biofilm forming ability, antibiotic resistance and expression of virulence-associated genes. Except for a few instances, disinfectant exposure did not alter antibiotic susceptibility. However, SH and HP exposure enhanced the biofilm forming ability of Salmonella Enteritidis NCTC 13349. After BAC and HP exposure, biofilm-derived cells presented a down-regulation of rpoS. Exposure to BAC also revealed an up-regulation of invA, avrA and csgD on Salmonella Enteritidis NCTC 13349. The results obtained suggest that biofilm-derived cells that survive disinfection may represent an increased health risk.This study was supported by the Portuguese Foundation forScience and Technology (FCT) under the scope of the stra-tegic funding of unit UIDB/04469/2020 and BioTecNorteoperation (NORTE-01-0145-FEDER-000004) funded by theEuropean Regional Development Fund under the scope ofNorte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

    O impacto de biofilmes microbianos na higiene e segurança alimentar

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    Em 2012 foram reportados na União Europeia 5363 surtos de origem alimentar, resultando em 55453 casos humanos, os quais causaram 5118 hospitalizações e 41 mortes [1]. A maioria dos surtos notificados foi provocada por Salmonella, toxinas bacterianas, vírus e Campylobacter. Além destes microrganismos, Listeria monocytogenes, Escherichia coli e Staphylococcus aureus estão também entre os patogénicos alimentares mais problemáticos. A formação de biofilmes nas superfícies de processamento de alimentos é uma das principais causas destes surtos. De facto, todos estes microrganismos apresentam uma grande capacidade para formar biofilmes e estes podem desenvolver-se em todo o tipo de superfícies na indústria alimentar, incluindo aço inoxidável, polipropileno, vidro, etc. Os biofilmes constituem uma fonte de contaminação dos alimentos com que contactam e o seu desprendimento das superfícies causa ainda a contaminação do ambiente circundante. Pode definir-se biofilme como um agregado de células microbianas formado sobre uma superfície ou interface frequentemente envolto numa matriz de substâncias poliméricas, a maioria de origem microbiana [2]. Estas estruturas apresentam uma grande tolerância a agressões externas, nomeadamente a agentes antimicrobianos químicos. A tolerância inerente dos biofilmes a biocidas químicos tem suscitado o interesse no desenvolvimento de métodos alternativos de controlo de patogénicos alimentares. Neste artigo serão abordados os princípios fundamentais de adesão e persistência de patogénicos alimentares nas superfícies alimentares e de contacto com alimentos. Será referido o papel dos biofilmes na resistência cruzada e por fim serão apresentados 2 métodos inovadores de controlo de biofilmes

    Comparação da técnica de estabilização rítmica e alongamento passivo em membros inferiores para aumento de amplitude de movimento em atletas de futsal

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    O alongamento passivo aparece no contexto esportivo como um dos principais procedimentos utilizados pela Educação Física e Fisioterapia com a finalidade da melhora da amplitude de movimento (ADM) e prevenir lesões. A estabilização rítmica (ER), uma técnica da facilitação neuromuscular proprioceptiva, utiliza a contração isométrica alternada de músculos agonistas e antagonistas para estabilizar uma articulação e equilibrar os músculos, pois envolve a participação do fuso neuromuscular, atuando na integridade do músculo. Entretanto, a literatura não registra trabalhos sobre o uso desta técnica como possibilidade de aumento de amplitude de movimento articular. O futsal, um dos esportes mais praticados no Brasil, exige grande performance física de seus atletas, o que, por sua vez, pode levar a lesões musculoesqueléticas, alterações na ADM, principalmente de membros inferiores. Assim, o presente estudo teve como objetivo comparar a técnica de ER e alongamento passivo para membros inferiores em atletas de futsal a fim de verificar qual técnica é mais eficaz para o aumento da ADM de flexores da articulação do quadril. Foram estudados 14 atletas divididos em dois grupos, aplicando a técnica de ER e de alongamento passivo 3 vezes por semana, durante um período de quatro meses, após os treinamentos. A ADM de flexão ativa da articulação do quadril foi avaliada a fim de verificar se houve aumento nas medidas. Os resultados demonstraram que a ER teve um aumento significativo na ADM comparada ao alongamento passivo

    Anatomia da artéria pudenda superficial externa: estudo quantitativo

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    The importance of the superficial external pudendal artery in cases of lower limb obstructive arteriopathies has been established, and a perfect knowledge of its anatomy is desirable for the creation of successful flaps involving it. However, little information is available on the morphometry of this artery. PURPOSE: In this study, we conducted a quantitative investigation of the superficial external pudendal artery as the basis for skin grafts. METHOD: Twenty-five right and left sides of the inguinal region of male cadavers were dissected. After retracting the skin at the inguinal region, the femoral vessels and the sapheno-femoral junction were exposed. The following aspects were then analyzed: 1) the presence of the superficial external pudendal artery, 2) the place of origin of the superficial external pudendal artery and the common trunk, 3) the duplication of the superficial external pudendal artery, 4) the distance from the superficial external pudendal artery or the common trunk to the inguinal ligament, and 5) the diameter of the superficial external pudendal artery. RESULTS: The results were the following: 1) superficial external pudendal arteries were found in 46 of 50 sides (92%); 2) they originated from the femoral artery in 45 cases and from the deep femoral artery in only 1 case; 3) the arteries were found duplicated in 21 cases (46%), as a common trunk in 11 cases (24%), and as a single artery in 14 cases (30%); 4) the distance from the superficial external pudendal artery to the inguinal ligament ranged from 0.8 cm to 8.5 cm; from the common trunk, it ranged from 3.5 cm to 6.7 cm; 5) the diameter of the superficial external pudendal artery ranged from 1.2 mm to 3.8 mm; and 6) the diameter of the common trunk ranged from 1.35 mm to 5.15 mm. CONCLUSION: The results show that the superficial external pudendal artery generally originates from the femoral artery. It was found as a common trunk, duplicated, or as a single artery. There was a great variability in both the diameter of the artery and the distance from the artery to the inguinal ligament. Most of the data showed no significant differences between the right and the left sides.A importância do conhecimento da anatomia da artéria pudenda superficial externa está bem estabelecida e um conhecimento adequado de sua anatomia é desejável para a criação bem sucedida de flaps. Entretanto, são escassos os trabalhos morfométricos sobre esta artéria. OBJETIVO. No presente estudo, foi feita uma análise quantitativa da artéria pudenda superficial externa, como base para enxertos de pele. MÉTODO. Foram dissecadas 25 regiões inguinais direitas e 25 esquerdas de cadáveres do sexo masculino. Após rebater a pele da região inguinal, os vasos femorais, a junção safeno-femoral e a artéria pudenda superficial externa foram expostas. Os seguintes aspectos foram então analisados: 1. Presença da artéria pudenda superficial externa; 2. Local de origem da artéria pudenda superficial externa ou do tronco comum; 3. Duplicação da artéria pudenda superficial externa; 4. Distância da artéria pudenda superficial externa ou do tronco comum ao ligamento inguinal; 5. Diâmetro da artéria pudenda superficial externa. RESULTADOS. Os resultados mostraram que: 1. A artéria pudenda superficial externa foi encontrada em 46 dos 50 lados dissecados (92%); 2. A artéria teve origem na artéria femoral em 45 casos; em um único caso teve origem na artéria femoral profunda; 3. A artéria foi encontrada duplicada, em 21 casos (46%), formando um tronco comum, que depois se bifurcava, em 11 casos (24%) e como uma artéria única 14 vezes (30%); 4. A distância da artéria ao ligamento inguinal variou de 0,8 cm a 8,5 cm; quando sob a forma de tronco comum, esta distância variou de 3,5 cm a 6,7 cm; 5. O diâmetro da artéria pudenda superficial externa variou de 1,36 mm a 5,15 mm. CONCLUSÕES. Os resultados mostram que a artéria pudenda superficial externa origina-se, na grande maioria dos casos, da artéria femoral. Foi encontrada como um tronco comum, duplicada ou como uma artéria única. O diâmetro da artéria mostrou grande variabilidade assim como a distância da artéria ao ligamento inguinal. A maioria dos dados não mostrou diferença significante entre os lados direito e esquerdo

    Implementing open-source information systems for assessing and managing the seismic vulnerability of historical constructions

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    Reducing the uncertainty about the structural vulnerability of historical constructions comprises the selection of reasonably generalised approaches in a context of a significant typological variability; the difficulty of performing large-scale assessments with reasonable reliability; and the lack of dedicated infrastructures for efficiently storing, sharing, managing, and updating data – an issue that is even more relevant for small (and often isolated) settlements. This work presents a proposal to set up a geographic database for surveying, calculating and storing the seismic vulnerability index of masonry constructions using an adapted version of the GNDT-II approach. Some critical steps for setting up Geographical Information System (GIS) databases for storing and managing the fields of a parameter-based vulnerability assessment are presented. Then, some alternatives for distributing the database are introduced, including cloud-based distribution and Transactional Web Feature Service (WFS-T) protocols, even using virtual servers. Additionally, an alternative front-end for accessing data and calculating the vulnerability index of constructions and levels of damage is presented. The main objective is to offer a replicable and feasible workflow to be performed even with reduced infrastructure and computational resources but can be easily connected and associated to a progressively enlarged system based on free and open-source software
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