114 research outputs found
Non-loadbearing light steel framing walls under fire
The light steel frame (LSF) construction technology started to be widely used in different types of buildings, replacing the traditional construction methods due to its light weight characteristics. Steel is recycled, dimensional stable, and ease of installation. LSF and prefabricated panels are widely used in non-loadbearing walls. The LSF walls are usually made with studs and tracks that require fire protection, normally achieved by a single plasterboard, by composite plates, or by insulation of the cavity. The partition walls are fire rated for the integrity (E) and insulation (I). The insulation capacity (I) is the ability of the element of construction to withstand fire exposure by side, without the transmission of significant heat to the unexposed side. Six fire tests were developed to define the fire resistance according to EN1363-1 [1] and EN1364-1 [2], with the main objective to evaluate the influence of the protection layers and the influence of the cavity insulation material. Numerical models are also validated with experimental tests.info:eu-repo/semantics/publishedVersio
Fire resistance of composite non-load bearing light steel framing walls
The light steel frame walls are mostly used for non-load bearing applications. The light steel
framed walls are made with studs and tracks that require fire protection, normally achieved by
single plasterboard, by composite protection layers or by insulation of the cavity. The partition
walls are fire rated to resist by integrity and insulation. Seven small-scale specimens were tested
to define the fire resistance of non-load bearing light steel frame walls made with different materials.
All tests were validated using two-dimensional numerical models, based on the finite-element
method, the finite-volume method and hybrid finite-element method. A good agreement was
achieved between the numerical and the experimental results from fire tests. The fire resistance
increases with the number of studs and also with the thickness of the protection layers. The
hybrid finite-element method solution method looks to be the best approximation model to predict
fire resistance.info:eu-repo/semantics/publishedVersio
Fire performance of non-loadbearing light steel framing walls - numerical and simple calculation methods
Light steel frame and prefabricated panels are widely used in non-loadbearing walls, with direct application to steel framed buildings. Such panels consist of steel sections (studs and tracks) with gypsum plasterboard layers attached to the flanges on the outside and use insulation material in the cavities. The fire resistance is usually provided by one or more layers of panels and by the insulation material. This investigation evaluates the thermal behaviour of the unexposed surface and of the nodal internal layers, using numerical simulations and a simple calculation method, assuming that heat flow is almost one-dimensional. The fire resistance is compared for both models using a cross section of the wall with one and two gypsum layers. The insulation criterion is the only one used for the calculation of the fire resistance, based on the calculation of the average and maximum temperature of the unexposed surface above the initial average temperature. Good approach was achieved by the simple calculation model, when optimum effective width is assumed for the model.info:eu-repo/semantics/publishedVersio
Efeito do confinamento em secções parcialmente embebidas com betão
As secções parcialmente embebidas com betão silo uma solução de construção mista que utiliza um perfil metálico parcialmente revestido com betão reforçado. Esta característica construtiva aumenta a resistência do perfil metálico à temperatura ambiente e em particular, quando submetido a condições de incêndio. Neste artigo é efectuado um estudo paramétrico sobre a influência do confinamento do betão na resistência última de elementos parcialmente embebidos, quando submetidos à flexão. É apresentado um estudo numérico não linear, geométrico e material, em relação ao valor do grau de confinamento e em relação ao factor efectivo de confinamento
DIREITO À EDUCAÇÃO DE CRIANÇAS PÚBLICO-ALVO DA EDUCAÇÃO ESPECIAL NA EDUCAÇÃO INFANTIL: O QUE DIZEM OS PROFESSORES ESPECIALIZADOS
Este trabalho analisa os conceitos de inclusão escolar e de direito à educação de crianças público-alvo de educação especial na educação infantil, presentes no debate de diversas temáticas evidenciadas nos discursos de professores de educação especial, de um município que conseguiu atender a meta de acesso dessas crianças nessa modalidade de ensino nas creches e pré-escolas. Para tanto, realiza um estudo exploratório com professoras especializadas, atuantes nas instituições de educação infantil, e gestores(as) de educação infantil, educação especial e de formação, que atuam no âmbito do Sistema Municipal de Educação de Vitória/ES. Com base em uma abordagem qualitativa, o estudo exploratório envolve análises documental e bibliográfica, a realização de grupo focal com professoras de educação especial e a aplicação de entrevista semiestruturada aos participantes como instrumento para a investigação do tema. De certo modo, as narrativas apontam a necessidade de avanço na concepção do direito à qualidade da educação especial, porém, sobre educação especial na perspectiva de uma educação inclusiva, emancipadora e libertadora, observa-se que necessitam de aprofundamento para uma formação que potencialize a articulação entre as concepções específicas e, de forma geral, sobre educação, direito à educação e à inclusão escolar. Ainda que o município de Vitória/ES avance na meta de acesso de quase 100% de crianças nas instituições de educação infantil públicas, com aumento de matrículas na educação especial e investimentos em política de formação de professores de educação especial, as professoras relatam dificuldade no entendimento, tanto delas quanto dos demais professores e profissionais na escola, sobre o trabalho docente a ser desenvolvido, suas atribuições e as dificuldades na oferta e execução dos serviços de apoio. Existem intensos investimentos do município, nos processos de formação continuada, porém desenvolvida, na sua maioria nos cursos com os professores especializados. Nesse sentido, consideramos que os processos formativos necessitam ser ampliados a todos(as) os(as) profissionais da instituição de educação infantil, que trabalham na perspectiva da inclusão de crianças indicadas à educação especial. Ainda é preciso intensificar a luta pelo reconhecimento desse direito das crianças pequenas público
alvo da educação especial na educação infantil. Outro destaque evidenciado pela pesquisa foi de que cerca de 70% das professoras participantes apresentaram um ecletismo teórico-metodológico ao relatar suas concepções a respeito do desenvolvimento infantil de crianças público da educação especial. Esse dado pode conduzir à fragilidade da concepção de direito à educação e à inclusão escolar dessas crianças, ao enfatizarem mais causas orgânicas em detrimento das culturais para o desenvolvimento infantil desse grupo. Nessa direção, concluímos que as normativas municipais das políticas de educação especial e infantil necessitam se ocupar dos processos formativos dos profissionais, considerando os avanços apresentados em relação às concepções de direito à educação e à inclusão escolar de crianças público da educação especial nas instituições municipais de educação infantil e a necessidade de que esses processos possam corresponder a esses avanços
Photorelease of amino acids from novel thioxobenzo[f]benzopyran ester conjugates
Aiming at the enhancement of the performance of (9-methoxy-3-oxo-3H-benzo[f]benzopyran-1-yl) methyl ester as photocleavable protecting group for the carboxylic acid function at long-wavelengths, 9-methoxy-3-thioxo-3H-benzo[f]benzopyran-L-valine and L-phenylalanine model conjugates were prepared through a thionation reaction of the corresponding oxo-benzobenzopyrans. These thioxobenzobenzopyran derivatives were subjected to photocleavage reactions in the same conditions as the parent oxo-benzobenzopyrans at different wavelengths of irradiation, and photocleavage kinetic data was obtained. It was found that the exchange of the carbonyl by a thiocarbonyl group enhanced the performance of the heterocyclic protecting group at 419 nm by improving the photolysis rates, making it an appropriate group for practical applications at long wavelengths.Fundo Europeu de Desenvolvimento Regional (FEDER) - POCI 2010Fundação para a Ciência e a Tecnologia (FCT) - REDE/1517/RMN/200
Photolysis at long wavelengths of amino acid ester derivatives based on 4-methyl-6-methoxy-2-oxo-2H-naphtho[1,2-b]pyrans
Ester derivatives of fused 4-methyl-6-methoxy-2-oxo-2H- naphtho[1,2-b]pyran, using valine and phenylalanine as model bifunctional molecules were synthesised, to assess its applicability as a photocleavable protecting group, for solution phase organic synthesis and in caging applications, at longer wavelengths. The behaviour of the corresponding derivatives towards photolysis was evaluated by irradiation in mixture of HEPES buffer and acetonitrile or methanol, in a photochemical reactor at 350 and 419 nm, followed by HPLC/UV monitoring. Time-resolved fluorescence measurements were used to elucidate the dynamics.Fundação para a Ciência e a Tecnologia (FCT) -PTDC/QUI/69607/2006, SFRH/BD/61459/2009Fundo Europeu de Desenvolvimento Regional (FEDER) - REDE/1517/RMN/200
Label-free quantum dot conjugates for human protein IL-2 based on molecularly imprinted polymer
The authors acknowledge the financial support from European Research Council though the
Starting Grant, ERC-StG-3P´s/2012, GA 311086, (to MGF Sales) and from the CANCER project (NORTE-01-0145-
FEDER-000029).info:eu-repo/semantics/publishedVersio
Phototriggered release of tetrapeptide AAPV from coumarinyl and pyrenyl cages
Ala-Ala-Pro-Val (AAPV) is a bioactive tetrapeptide that inhibits human neutrophil elastase (HNE), an enzyme involved in skin chronic inflammatory diseases like psoriasis. Caged derivatives of this peptide were prepared by proper N- and C-terminal derivatisation through a carbamate or ester linkage, respectively, with two photoactive moieties, namely 7-methoxycoumarin-2-ylmethyl and pyren-2-ylmethyl groups. These groups were chosen to assess the influence of the photosensitive group and the type of linkage in the controlled photorelease of the active molecule. The caged peptides were irradiated at selected wavelengths of irradiation (254, 300, and 350 nm), and the photolytic process was monitored by HPLC-UV. The results established the applicability of the tested photoactive groups for the release of AAPV, especially for the derivative bearing the carbamate-linked pyrenylmethyl group, which displayed the shortest irradiation times for the release at the various wavelengths of irradiation (ca. 4 min at 254 nm, 8 min at 300 nm and 46 min at 350 nm).Thanks are due to the Fundação para a Ciência e Tecnologia (FCT, Portugal) for
financial support to the portuguese NMR network (PTNMR, Bruker Avance III 400-
Univ. Minho), FCT and FEDER (European Fund for Regional Development)-
COMPETE-QREN-EU for financial support through the Chemistry Research Centre of
the University of Minho (Ref. UID/QUI/00686/2013 and UID/QUI/0686/2016). A PhD
grant to A.M.S. (SFRH/BD/80813/2011) is also acknowledged.info:eu-repo/semantics/publishedVersio
Hemorheological, biochemical and cardiovascular characterization of a rat model of moderate chronic kidney disease
Chronic kidney disease (CKD) is a major public health problem throughout the world. The major outcomes include a rapid progression, with development of anaemia and serious complications, namely thromboembol
ic and cardiovascular events. The pathophysiological alterations depend on the CKD degree, which will also determine the moment to initiate hemodialysis and recombinant erythropoietin (rhEPO) therapies Thus, the cardio-renal complication might be better prevented or delayed if CKD patients are earlier identified and treated for the associated anaemia, which will depend on a better characterization of moderate stages of CKD. This study aimed to characterization an animal of model of moderate CKD induced by partial (%) nephrectomy, by evaluating hemorheological, biochemical and cardiovascular profiles. Blood samples from control and CKD rats were collected at 0, 3, 9 and 15 weeks in order to evaluate: renal function, hemorheological parameters, iron metabolism, blood lipids, peripheral sympathetic and serotonergic systems, redox state and inflammatory markers. BP, tissues uophism indexes and kidney histomorphology were also assessed. Our data is consistent with a sustained moderate degree of CKD with a quickly compensated modest anaemia, though presenting iron metabolism disturbances. Despite the reasonable degree of functionality of the remnant kidney, as suggested by the anaemia correction and by the kidney hypertrophy, several important cardiovascular modifications were developed. Our model presented hypertension, dyslipidaemia, erythropoietic disturbances, sympathetic activation and oxidative stress. This model might be a good tool to study the cellular/molecularmechanisms underlying moderate stages of CKD and to evaluate the therapeutics efficacy for prevention, treatment/correction of cardiorenal anaemia syndromes and complications in early stages.info:eu-repo/semantics/publishedVersio
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