84 research outputs found

    Thermal performance characterization of a modular system for facade

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    The developed system corresponds to multifunctional prefabricated modular elements that combine an insulation layer with a cast coating material for exterior that can imitate stone or concrete. These systems need auxiliary elements of fixing to connect them mechanically to the structural wall of the building, in order to ensure its stability, using anchorage, profiles, rails, among others. The use of these systems connected to the coating interrupts the continuity of thermal insulation, causing additional heat losses through linear and point thermal bridges, having an detrimental effect on thermal performance of the system. The development of fixing of present multifunctional panels was based on the evaluation and adoption of appropriate solutions in order to minimize thermal bridges and reinforce the stability of the panel. For evaluation purposes some models are evaluated, with different connecting systems, configurations and different materials such as aluminium, stainless steel, galvanized steel and Glass Fibre Reinforced Polymer (GFRP) profiles. The quantification of thermal bridges, for evaluation of thermal performance, has been made using computing programs, HEAT2 and HEAT3. The evaluation of a system developed in this research work, i.e. incorporating profiles in thermal insulation, shows a good thermal resistance contributing significantly to the thermal insulation and energy conservation in building.Project QREN SI: I&DT of Portugal under project number 2010/1287

    Argamassas de terra e cal reforçadas com fibras naturais

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    As principais vantagens do uso da terra e cal em argamassas de reboco podem ser resumidas a: promoção de um melhor controlo da humidade relativa do ar, resultando num ambiente interior mais saudável; vantagens económicas e ambientais, pelo reduzido consumo de cal que conduz a uma menor energia incorporada, sendo o custo também menor; e a estética, que por si só permite a obtenção de cores e texturas bastante interessantes. O presente trabalho de investigação foi desenvolvido com o principal objetivo de melhorar as características básicas das argamassas de reboco de terra e cal, em especial para contrariar o efeito de retração de argilas no sentido de evitar a sua fissuração. Para o efeito estudou-se uma argamassa padrão feita de terra e cal, sem a adição de fibras e a incorporação de vários tipos de fibras na argamassa padrão. Foi testada a adição de fibras naturais (banana, coco, sisal) e, a fim de comparar os resultados, foi também testada a incorporação de fibras sintéticas (polipropileno). Devido à grande variedade de tipos e quantidades de argila presentes na terra, com comportamentos distintos, foram realizados testes expeditos de modo a quantificar e caracterizar a argila presente no solo utilizado. Para avaliar o desempenho das fibras incorporadas nas argamassas foram realizados testes laboratoriais para obter as propriedades mais relevantes: trabalhabilidade; comportamento mecânico; comportamento à água; e suscetibilidade à fissuração

    Natural illumination availability in Ponte de Pedra apartment block: a case study

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    This paper presents the results of the in-situ measurements of the natural illumination availability in the Ponte da Pedra apartments block, These measurements were carried out in order to meet the SHE (Sustainable [lousing in Europe) project requirements, This paper also presents a comparative analysis of the natural illumination environmental conditions of one of the apartments in this building, by using two simulation tools to predict natural illumination availability: "Ecotect" and "Desktop Radiance", The results obtained with these tools were also compared with the "in situ" measurements, in order to show that simple and user-friendly software tools can be a good basis to evaluate the real natural illumination conditions in the practise of a building project

    Caracterização de materiais compósitos à base de gesso FGD

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    Este estudo visa a valorização de diversos subprodutos industriais como o gesso da dessulfuração de gases de combustão das centrais termoeléctricas, designado convencionalmente por gesso FGD (“flue gas desulfurization”), o re-granulado de cortiça resultante do fabrico de placas de aglomerado negro de cortiça e as fibras têxteis resultantes da reciclagem de pneus usados. Os materiais compósitos resultantes das misturas destes subprodutos podem ser conformados por dois processos distintos, a moldagem e a prensagem, obtendo-se produtos com características distintas. Por moldagem obtêm-se um compósito leve e por prensagem obtêm-se um material mais denso, com maiores resistências mecânicas e melhor acabamento superficial. Estes compósitos poderão ter várias aplicações na construção, nomeadamente no fabrico de blocos para paredes interiores dos edifícios. Neste contexto, foi realizada uma campanha experimental de modo a determinar as características mecânicas dos referidos compósitos no sentido de validar a sua aplicabilidade na construção

    Caracterização de materiais compósitos à base de gesso FGD

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    Este estudo visa a valorização de diversos subprodutos industriais como o gesso da dessulfuração de gases de combustão das centrais termoeléctricas, designado convencionalmente por gesso FGD (“flue gas desulfurization”), o re-granulado de cortiça resultante do fabrico de placas de aglomerado negro de cortiça e as fibras têxteis resultantes da reciclagem de pneus usados. Os materiais compósitos resultantes das misturas destes subprodutos podem ser conformados por dois processos distintos, a moldagem e a prensagem, obtendo-se produtos com características distintas. Por moldagem obtêm-se um compósito leve e por prensagem obtêm se um material mais denso, com maiores resistências mecânicas e melhor acabamento superficial. Estes compósitos poderão ter várias aplicações na construção, nomeadamente no fabrico de blocos para paredes interiores dos edifícios. Neste contexto, foi realizada uma campanha experimental de modo a determinar as características mecânicas dos referidos compósitos no sentido de validar a sua aplicabilidade na construção

    Bioactivity of the specie Annona coriacea: A systematic review / Bioatividade da espécie Annona coriacea: Uma revisão sistemática

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    The araticum (Annona coriacea Mart.) is a tree of the Annonaceae family with great distribution in the northern Cerrados of the State of Piauí. Several species of this family have medicinal use and demonstrate some biological activities that have already been experimentally proven such as antihelmintic, antimalarial, antimicrobial, antinociceptive, antiprotozoal, insecticidal, parasiticidal and antioxidant activities due to the presence of acetogenins. The objective of this study was to carry out a scientific and technological prospection of the Annona coriacea plant related totickcidal activity. The scientific bases used were; PubMed, ScienceDirect and Web of Science and the technological databases include; EPO, WIPO, USPTO, DII, LATIPAT and INPI, with the following keywords: Annona coriacea, Annona coriacea and tickcidal, Annona coriacea and acaricide and Annona coriacea and biocide, all articles published in the last decade and without temporal cut for patent registration being counted. We found 156 articles and 17 patents, most of them dealing with medicinal use and chemical composition of the plant. The study showed that there is interest in the plant studied, but there is a wide field to carryout studies on technological innovation and development of new products, as in the area of tickcidal products

    pH-responsive phthalate cashew gum nanoparticles for improving drugs delivery and anti-Trypanosoma cruzi efficacy

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    Funding Information: The authors acknowledge Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco ( FACEPE ) for a scholarship. This study was supported by funding from the Spanish Group CTS-946 and project P18-RT-3786 . Publisher Copyright: © 2023 Elsevier B.V.Nanotechnology is a crucial technology in recent years has resulted in new and creative applications of nanomedicine. Polymeric nanoparticles have increasing demands in pharmaceutical applications and require high reproducibility, homogeneity, and control over their properties. Work explores the use of cashew phthalate gum (PCG) as a particle-forming polymer. PCG exhibited a pH-sensitive behavior due to the of acid groups on its chains, and control drug release. We report the development of nanoparticles carrying benznidazole. Formulations were characterized by DLS, encapsulation efficiency, drug loading, FTIR, pH-responsive behavior, release, and in vitro kinetics. Interaction between polymer and drug was an evaluated by molecular dynamics. Morphology was observed by SEM, and in vitro cytotoxicity by MTT assay. Trypanocidal effect for epimastigote and trypomastigote forms was also evaluated. NPs responded to the slightly basic pH, triggering the release of BNZ. In acidic medium, they presented small size, spherical shape, and good stability. It was indicated NP with enhanced biological activity, reduced cytotoxicity, high anti T. cruzi performance, and pH-sensitive release. This work investigated properties related to the development and enhancement of nanoparticles. PCG has specific physicochemical properties that make it a promising alternative to drug delivery, however, there are still challenges to be overcome.publishersversionpublishe

    Milk fatty acid profile of Holstein x Gyr cows on 'Marandu' grass pasture under different grazing strategies

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    O objetivo deste trabalho foi avaliar o perfil de ácidos graxos (AG) do leite de vacas Holandesas x Gir submetidos a dois tipos de manejo de pastejo (períodos de descanso fixo e variável) de pastagem de Urochloa brizantha 'Marandu'. Utilizou-se o delineamento de blocos ao acaso, com duas repetições de área de pastagem (blocos) por tratamento e quatro vacas por bloco. A produção e a composição do leite não foram influenciadas pelas estratégias de pastejo. Não houve efeito dos tratamentos sobre as proporções (g 100 g-1 de AG totais) dos principais AG (palmítico, linoleico e α-linolênico) do pasto, mas suas ingestões (gramas por dia) foram influenciadas pelas diferenças de ingestão de matéria seca da forragem. As concentrações dos AG no plasma e na gordura do leite não foram influenciadas pelos tratamentos. As concentrações dos ácidos rumênico, vacênico, oleico e α-linolênico na gordura do leite variaram de 0,71 a 0,93, 1,40 a 1,50, 19,40 a 19,70 e 0,39 a 0,43 g 100 g-1 de AG totais, respectivamente. As estratégias de pastejo de U. brizantha 'Marandu' não alteram o perfil de ácidos graxos do leite das vacas.The objective of this work was to evaluate the milk fatty acid (FA) profile of Holstein x Gyr cows subjected to two different grazing managements (fixed and variable rest periods) of Urochloa brizantha 'Marandu' pastures. A randomized complete block design was used, with two replicates of pasture areas (blocks) per treatment and four cows per block. Milk production and composition were not affected by grazing strategies. No treatment effects were observed on the proportions (g 100 g-1 of total FA) of the main FAs (palmitic, linoleic, and α-linolenic) of the pasture, but their intakes (grams per day) were affected by differences in forage dry matter intake. The concentrations of FAs in milk plasma and fat were not affected by the treatments. Milk fat contents of rumenic, vaccenic, oleic, and α-linolenic acids varied from 0.71 to 0.93, 1.40 to 1.50, 19.40 to 19.70, and 0.39 to 0.43 g 100 g-1 total FAs, respectively. Grazing strategies of U. brizantha 'Marandu' cause no changes on the milk fatty acid profile of cows

    Levels of organochlorine contaminants in natural bovine milk marketed in Mojuí dos Campos and Belterra, Brazil

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    Analyzing the organochlorine pesticide (OCP) content in milk is relevantbecause it helps evaluate the quality of milk that reaches the consumer's table and also helps identify the geographical areas where there is a high possibility of contamination. Accordingly,thispilot project was aimed at determining the extent of contamination by OCP residues and their metabolites in fresh cow's milk in Mojuí dos Campos and Belterra, Pará, using solid-phase extraction (SPE) and gas chromatography coupled with electron capture detection (GC-ECD). The OCPs evaluated in this study weredichlorodiphenyltrichloroethane (DDT) and its metabolites (dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)), hexachlorocyclohexane (HCH) (α, β, γ, and δ), endosulfanα and β, andendosulfansulfate. None of the thirty bovine milk samples analyzedshowed any contamination with OCPs.TheOCP content was within the limit of quantification of the method. The results of this study add to the existing knowledge on the quality ofbovine milk produced in these locations. However, further researchon other environmental matricesis required to confirm the results obtained in this study
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