440 research outputs found

    MODE I FRACTURE CHARACTERIZATION: WOOD SEN-TPB

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    The single edge notched beam loaded in three-point-bending (SEN-TPB) was used in this study to induce mode I fracture in wood (Picea abeas L.). Numerical analyses of stress profiles along the specimen length revealed a stress relief region as crack grows in size. Based on this data, beam theory and crack equivalent concepts were employed to develop an expedite data reduction scheme to estimate the Resistance-curve, taking advantage of a simplification performed on the revealed stress relief region. Besides allowing the evaluation of wood fracture toughness without crack length monitoring during loading, the developed procedure provides a user-friendly method when compared to other sophisticated procedures. Experiments involving the SEN-TPB were performed to evaluate fracture toughness in wood

    Wood beam repairing with carbon-epoxy composites

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    Wood damaged beams submitted to bending loads were repaired using carbon-epoxy patches. The effect of patch thickness as well as adhesive filleting were both studied experimentally and numerically. The objective was to verify the influence of these aspects on the strength and failure of the repaired structural components. Cohesive zone modeling considering mixedmode (I+II) loading was carried out to simulate the observed experimental behavior. It was concluded that repair can successful recover the original bearing capacity, although patch thickness and adhesive filleting did not reveal a significant gain on strength

    Tuberculin skin testing versus interferon-gamma release assay among users of a public health unit in Northeast Portugal

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    he screening of groups with a high risk for developing tuberculosis (TB) is a priority in order to control this disease. Since there is no gold standard for the diagnosis of latent TB infection (LTBI), both the tuberculin skin test (TST) and the interferon-gamma release assays (IGRA) have been used for this purpose. The aim of this study was to determine the proportion of LTBI by using the TST and the IGRA tests, and to assess the risk factors related with discordant results between tests across several risk groups advised for screening in Northeast Portugal. Data were collected from the database of patients with suspected LTBI and advised for the screening in a public health unit (January 2014 to December 2015). The proportion of LTBI was computed using both tests. Logistic regression models assessed risk factors for a positive test and for discordant results between tests. The adjusted odds ratio (OR) and respective 95% confidence interval (95% CI) were obtained. Out of 367 patients included in the analysis, 79.8% had a positive TST and 46.0% of them had a positive IGRA. In comparison with contacts of active TB cases, healthcare workers and inmates presented higher odds of TST positivity (OR 4.38, 95% CI 1.59–12.09 and OR 4.74, 95% CI 1.45–15.49, respectively), but immunocompromised people presented lower odds of TST positivity (OR 0.14; 95% CI 0.06–0.31). Instead, healthcare workers (OR 0.44, 95% CI 0.24–0.80) and immunocompromised people (OR 0.24, 95% CI 0.10–0.56) presented lower odds of a positive IGRA. There were 42.0% concordant positive results, 16.1% concordant negative results, and 41.9% discordant results, with healthcare workers presenting higher odds of discordant results (OR 3.34, 95% CI 1.84–6.05). The proportion of LTBI estimated by TST and IGRA among people advised for screening in our setting is high, highlighting the need of preventive strategies. Among healthcare workers, TST results should be read with caution as the higher proportion of discordant results with a positive TST suggests the impact of the booster reaction in this group.info:eu-repo/semantics/publishedVersio

    Non-Newtonian fluid flow through three-dimensional disordered porous media

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    We investigate the flow of various non-Newtonian fluids through three-dimensional disordered porous media by direct numerical simulation of momentum transport and continuity equations. Remarkably, our results for power-law (PL) fluids indicate that the flow, when quantified in terms of a properly modified permeability-like index and Reynolds number, can be successfully described by a single (universal) curve over a broad range of Reynolds conditions and power-law exponents. We also study the flow behavior of Bingham fluids described in terms of the Herschel-Bulkley model. In this case, our simulations reveal that the interplay of ({\it i}) the disordered geometry of the pore space, ({\it ii}) the fluid rheological properties, and ({\it iii}) the inertial effects on the flow is responsible for a substantial enhancement of the macroscopic hydraulic conductance of the system at intermediate Reynolds conditions. This anomalous condition of ``enhanced transport'' represents a novel feature for flow in porous materials.Comment: 5 pages, 5 figures. This article appears also in Physical Review Letters 103 194502 (2009

    Association of morphological and water factors with irrigated forage cactus yield

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    This study aimed to understand the relationship of morphological characteristics and actual evapotranspiration of forage cactus clones with their productive capacity under different water regimes. The data used in this study were collected between the years 2012 and 2013, in Serra Talhada, State of Pernambuco. The clones Sertânia IPA - IPA, Miúda - MIU and Orelha de Elefante Mexicana - OEM were submitted to three irrigation depths (2.5, 5.0 and 7.5 mm) and three irrigation intervals (7, 14 and 28 days). Cladode and plant morphology, accumulated actual evapotranspiration and yield were obtained at the moment of harvest. Pearson’s correlation matrix was elaborated and, in the sequence, multicollinearity, canonical and path analysis were applied. There was no correlation of yield with the soil water supply and actual evapotranspiration of the clones (p > 0.05). Forage cactus yield was more associated with peculiarities of the morphological characteristics of the clones than with the different soil water supplies or the crop actual evapotranspiration. However, regardless of the water regime and clone, the vigor of the basal cladodes was highly decisive for the expression of the forage cactus productive capacity.Objetivou-se, neste trabalho, compreender a relação de características morfológicas e da evapotranspiração real de clones de palma forrageira com sua capacidade produtiva em diferentes regimes hídricos. Os dados usados nesta pesquisa foram coletados entre os anos de 2012 e 2013, em Serra Talhada, PE. Os clones IPA Sertânia - IPA, Miúda - MIU e Orelha de Elefante Mexicana - OEM foram submetidos a três lâminas (2,5; 5,0; e 7,5 mm) e três intervalos de irrigação (7; 14 e 28 dias). Dados morfológicos dos cladódios e da planta, evapotranspiração real acumulada e desempenho produtivo foram obtidos na ocasião da colheita. A matriz de correlação de Pearson foi elaborada e, em seguida, foram aplicadas análises de multicolinearidade, canônica e de trilha. Não houve correlação da produtividade com o suprimento de água e evapotranspiração real dos clones (p > 0,05). A produtividade da palma esteve mais associada a peculiaridades das características morfológicas dos seus clones do que aos diferentes suprimentos de água no solo ou à evapotranspiração real da cultura. Mas, independente do regime hídrico e do clone, o vigor do cladódio basal foi bastante decisivo para a expressão da capacidade produtiva da palma forrageira irrigada

    Tradução e validação para a língua portuguesa da escala de graduação da síndrome das pernas inquietas do Grupo Internacional do Estudo da Síndrome das Pernas Inquietas

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    BACKGROUND: Restless legs syndrome (RLS) is a chronic sensory-motor disorder characterized by unpleasant limb sensations and an irresistible urge to move. The International Restless Legs Syndrome Study Group developed the Restless Legs Syndrome Rating Scale (IRLS) to assess the severity of RLS symptoms. The objective of this study was to translate and validate the IRLS into Brazilian Portuguese. METHOD: The IRLS was translated into Brazilian Portuguese, analyzed, back translated to English, and compared to the original version. It was applied to 10 patients for cultural verification. The language was adjusted and the final version was administered to 30 patients (13 male, mean age 58.88±14.82). RESULTS: There was correlation among the IRLS evaluation of three experts. Many linguistic adaptations were required to achieve cultural adequacy and the Cronbach's alpha coefficient showed reliability of 80%. CONCLUSION: IRLS was translated, adapted, and validated to Brazilian Portuguese language, showing good reliability and validity.INTRODUÇÃO: A síndrome das pernas inquietas (SPI) é uma doença crônica, sensório-motora, caracterizada por sensações desagradáveis nos membros e uma urgência em movimentá-los. O Grupo Internacional de Estudos da Síndrome das Pernas Inquietas desenvolveu a Escala de Graduação da Síndrome das Pernas Inquietas (EGSPI) para avaliar a gravidade dos sintomas da SPI. OBJETIVO: Traduzir, adaptar culturalmente e validar a EGSPI para o português do Brasil. MÉTODO: A escala foi vertida para o português, analisada, vertida novamente para o inglês e comparada com a versão original. Foi aplicada em 10 pacientes para adequação cultural. A linguagem foi ajustada e a versão final foi aplicada em 30 pacientes (13 homens, idade média de 58,88±14,82). RESULTADOS: Houve correlação da aplicação da escala entre três avaliadores. Foram necessárias adaptações lingüísticas para adequação cultural e o alfa de Chronbach mostrou confiabilidade de 80%. CONCLUSÃO: A EGSPI foi traduzida, adequada e validada para o português do Brasil, com boa validade e confiabilidade.Federal University of São Paulo Department of NeurologyFederal University of São Paulo Department of MedicineFederal University of São Paulo Hospital São Paulo Sleep LaboratoryUNIFESP, Department of NeurologyUNIFESP, Department of MedicineUNIFESP, Hospital São Paulo Sleep LaboratorySciEL

    Growth Characteristics of Kikuyu Grass with Different Sources and Doses of Phosphorus

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    Growth is defined as the increase in size, volume and mass as a function of time. Growth analysis allows evaluating the final growth of the plant as a whole and the contribution of the different organs in total growth (Benincasa, 1988). The experiment had as objective to evaluate specific leaf area (SLA), leaf area per unit of leaf DM, leaf area ratio (LAR), leaf area per unit of whole plant DM, leaf weight ratio (LWR), leaf weight per unit of plant weight, leaf area index (LAI), leaf area per unit of soil area, leaf/stem ratio (LSR), leaf weight per unit stem weight, of 35 days old kikuyu grass with different sources and doses of P
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