646 research outputs found

    Electroactive polymer membranes as substrates for point-of-care devices

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    Point-of-care devices (POC) are becoming essential for medical assistance in emergency situations or location with difficult access to medical infrastructures. In this work, innovative microfluidic substrates based on electroactive poly(vinylidene-co-trifluorethylene)-P(VDF-TrFE) with tuned morphologies and adequate physicochemical properties were developed using electrospinning and phase inversion techniques, as alternative to commercially available two-dimensional microfluidic substrates based mainly on cellulose. Their hydrophilicity was tuned using plasma treatments and barriers were implemented using wax printing to fabricate a design able to carry out glucose assays as a proof of concept.FCT- Fundação para a Ciência e Tecnologia: PTDC/EMD-EMD/28159/2017; SFRH/BD/140698/2018. Spanish Ministry of Economy and Competitiveness (MINECO): MAT2016-76039-C4-3-R. Basque Government Industry and Education Departments: ELKARTEK, HAZITEK and PIBA (PIBA-2018-06

    Identification of harmonic current sources in single-phase power systems using feature selection techniques and artificial neural networks

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    Este trabalho consiste em apresentar um método para a identificação de cargas lineares e não-lineares comumente encontradas em sistemas elétricos residenciais. Desta identificação, soluções viáveis poderão ser aplicadas com o intuito de mitigar os níveis de emissão das correntes harmônicas geradas, advindas principalmente por cargas com características não-lineares. No desenvolvimento do método, utilizaram-se de técnicas para a seleção de atributos, de forma a minimizar a dificuldade em se identificar as cargas conectadas ao sistema. A etapa posterior de identificação foi realizada pela aplicação de redes neurais artificiais. Todas as situações de distorção harmônica foram geradas em laboratório por uma fonte de alimentação, onde em sua saída foram alocados analisadores de energia, responsáveis pela extração das medidas necessárias sobre as cargas residenciais em análise. Os resultados obtidos foram considerados satisfatórios, mostrando-se que a metodologia proposta pode ser também empregada pelas concessionárias de energia elétrica para que estas obtenham informações sobre o perfil das cargas instaladas em consumidores residenciais.This work presents a method to identify linear and nonlinear loads commonly encountered in residential electrical systems. From this method, feasible solutions can be applied to mitigate the high levels of harmonic currents, generated mainly by nonlinear loads. Techniques of feature selection were used to data preprocessing and to minimize the effort in identification of loads connected to the electrical system. For the next step, the load identification, artificial neural networks were applied. All harmonic distortion situations were created in laboratory from a power source, and in its outputs were inserted the loads and power quality analyzers, which perform the extraction of all measurements. The obtained results were considered satisfactory, which show that the methodology can be employed by power distribution companies in order to obtain information about the profile of loads used by residential consumers.FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    Permeability and effective thermal conductivity of bisized porous media

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    In the region of minimum porosity of particulate binary mixtures, heat exchange and permeability were found to be higher than the ones obtained with a mono-size packing built with the same small size particles used in the binary packing. This effect was noticed in the range of the particles size ratio 0.1–1.0. The obtained improvement on thermal performance is related to the increase of effective thermal conductivity (ETC) in the binary packing and to the increase in transversal thermal dispersion due to the porosity decrease and tortuosity increase. Permeability can increase by a factor of two, if the size ratio between small and large spheres of a loose packing stays in the range 0.3–0.5.Fundação para a Ciência e a Tecnologia (FCT) - POCI/ EQU/58337/200

    Geo-environmental mapping using physiographic analysis: constraints on the evaluation of land instability and groundwater pollution hazards in the Metropolitan District of Campinas, Brazil

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    Geo-environmental terrain assessments and territorial zoning are useful tools for the formulation and implementation of environmental management instruments (including policy-making, planning, and enforcement of statutory regulations). They usually involve a set of procedures and techniques for delimitation, characterisation and classification of terrain units. However, terrain assessments and zoning exercises are often costly and time-consuming, particularly when encompassing large areas, which in many cases prevent local agencies in developing countries from properly benefiting from such assessments. In the present paper, a low-cost technique based on the analysis of texture of satellite imagery was used for delimitation of terrain units. The delimited units were further analysed in two test areas situated in Southeast Brazil to provide estimates of land instability and the vulnerability of groundwater to pollution hazards. The implementation incorporated procedures for inferring the influences and potential implications of tectonic fractures and other discontinuities on ground behaviour and local groundwater flow. Terrain attributes such as degree of fracturing, bedrock lithology and weathered materials were explored as indicators of ground properties. The paper also discusses constraints on- and limitations of- the approaches taken

    First stage of the development of an eco-friendly detergent formulation for efficient removal of carbonized soil

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    Detergent formulations for cleaning a carbonized soil-degreasers-typically comprise surfactants, organic solvents, phosphate-based cleaning agents, and alkaline agents, which results in high pH values (>11) that raise human and environmental risks. It is important to develop eco-friendly and safer degreasers, while maintaining their cleaning efficiency. In this work, simple degreaser formulations, with a pH below 11 and without phosphates, were developed by using a mixture of solvent, surfactant, and water to remove carbonized soil. The efficiency of the new degreaser formulations (with 5 wt% solvent, 5 wt% nonionic or ionic surfactant, and 90 wt% water) was evaluated by an abrasion test in the removal of carbonized soil from ceramic and stainless steel surfaces and compared with a commercial product. The results obtained show that the formulations comprising isopropylene glycol (IPG) with C11-C13 9EOs and diethylene glycol butyl ether (BDG) with octyltrimethylammonium octanoate ([N1118][C8O2]) present the best cleaning efficiency for both surfaces. The composition of these formulations was optimized for each surface using a mixture design. The resulting formulations, despite having a simpler composition, a pH lower than 11, and being phosphate-free, presented a cleaning efficiency equal or slightly higher than the commercial control. These results show that it is possible to design degreasers that are much less aggressive to the environment and user, while simultaneously fulfilling the market requirements.publishe

    Biopsychosocial Aspects in Individuals with Acute and Chronic Rotator Cuff Related Shoulder Pain: Classification Based on a Decision Tree Analysis

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    Biopsychosocial aspects seem to influence the clinical condition of rotator cuff related shoulder pain (RCRSP). However, traditional bivariate and linear analyses may not be sufficiently robust to capture the complex relationships among these aspects. This study determined which biopsychosocial aspects would better classify individuals with acute and chronic RCRSP and described how these aspects interact to create biopsychosocial phenotypes in individuals with acute and chronic RCRSP. Individuals with acute (<six months of pain, n = 15) and chronic (≥six months of pain, n = 38) RCRSP were included. Sociodemographic data, biological data related to general clinical health status, to shoulder clinical condition and to sensory function, and psychosocial data were collected. Outcomes were compared between groups and a decision tree was used to classify the individuals with acute and chronic RCRSP into different phenotypes hierarchically organized in nodes. Only conditioned pain modulation was different between the groups. However, the tree combined six biopsychosocial aspects to identify seven distinct phenotypes in individuals with RCRSP: three phenotypes of individuals with acute, and four with chronic RCRSP. While the majority of the individuals with chronic RCRSP have no other previous painful complaint besides the shoulder pain and low efficiency of endogenous pain modulation with no signs of biomechanical related pain, individuals with acute RCRSP are more likely to have preserved endogenous pain modulation and unilateral pain with signs of kinesiophobia
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