360 research outputs found

    Desenvolvimento de ferramenta vocacionada para o dimensionamento de estruturas metálicas de acordo com a NP EN 1993-1-1

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    Trabalho desenvolvido em parceria com a empresa Casais.A presente comunicação descreve o desenvolvimento de uma ferramenta informática vocacionada para o dimensionamento de estruturas metálicas de acordo com a NP EN 1993 1 1 [1]. A ferramenta AciariUM é direcionada para a verificação e dimensionamento (ELU) de vigas-coluna em aço sujeitas a flexão composta desviada. Foi desenvolvida como meio de análise de elementos em aço e de verificação expedita dos resultados recolhidos a partir de programas comerciais de análise estrutural. Permite ao utilizador um controlo total sobre os resultados, na medida em que todo o algoritmo e procedimento de cálculo relativo a cada parâmetro está disponível para consulta e edição.É dirigido um especial agradecimento: à CASAIS – Engenharia e Construção, S.A. e à Universidade do Minho por acolherem este projeto; aos suportes dos programas CYPE 3D e Robot Structural Analysis pela disponibilidade com que interagiram com os autores deste projeto sempre que a sua intervenção foi solicitada

    From data acquisition to data fusion : a comprehensive review and a roadmap for the identification of activities of daily living using mobile devices

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    This paper focuses on the research on the state of the art for sensor fusion techniques, applied to the sensors embedded in mobile devices, as a means to help identify the mobile device user’s daily activities. Sensor data fusion techniques are used to consolidate the data collected from several sensors, increasing the reliability of the algorithms for the identification of the different activities. However, mobile devices have several constraints, e.g., low memory, low battery life and low processing power, and some data fusion techniques are not suited to this scenario. The main purpose of this paper is to present an overview of the state of the art to identify examples of sensor data fusion techniques that can be applied to the sensors available in mobile devices aiming to identify activities of daily living (ADLs)

    Embedding Multi-Wall Carbon Nanotubes as Conductive Nanofiller onto Bi2Te3 Thermoelectric Matrix

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    Thermoelectric Generators (TEGs) are devices that have the ability to directly convert heat into electrical power, or vice-versa, and are being envisaged as one off-the-grid power source. Furthermore, carbon-based materials have been used as a conducting filler to improve several properties in thermoelectric materials. The present work studied the influence on the thermoelectric performance of Bi2Te3 bulk materials by incorporating different concentrations of Multi-Walled Carbon Nanotubes (MWCNT). In order to control and understand the influence of MWCNT dispersion in the nanocomposite, two different production methods (manual grinding and ultrasonication) were carried out and compared. It was verified that a larger dispersion leads to a better outcome for thermoelectric performance. The achieved Seebeck coefficient was up to -162 μV K-1 with a Power Factor of 0.50 μW K-2m-1, for the nanocomposite produced with 11.8 %V of MWCNT. This result demonstrates the ability to increase the thermoelectric performance of Bi2Te3 throughout the addition of MWCNT

    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
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