940 resultados para Low cost piezoelectric sensor
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Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores
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Dissertação para obtenção do Grau de Mestre em Biotecnologia
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Dissertation presented in partial fulfilment of the Requirements for the Degree of Master in Biotechnology
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Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores
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Dissertação para obtenção do Grau de Doutor em Química Sustentável
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Tese apresentada para cumprimento dos requisitos necessários à obtenção do grau de Doutor em Ciências da Comunicação
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Hydrogen sulphide is one of the most toxic and corrosive compound present in swine-derived biogas streams.In this study, afield scale biotrickling filter for the removal of hydrogen sulfide was investigated.A Biofilter packed with supporting biofilm materials was fed continuously with a proprietary nutrient solution and operatedfor over 73days. The system has been operating with a H2S inlet concentrations ranging from 1,000to 3,000 ppm.Significant removal efficiencies >95% was demonstrated. pH of the stock feeding solution decreased from 6.2 to as low as 3.5within couple days.The resulting drop in pH provided circumstantial evidence to support biological H2 Soxidation to sulphuric acid by sulfide-oxidizers. Sulfur precipitation was also observed to occur. The results suggested that H2S removal from biogas stream can be efficiently achieved using portable, low cost and maintenance free biotrickling filters.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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This paper discusses the development of modular solutions for eco low-cost houses based on a pre-fabricated modular wall system environmentally sustainable, socioeconomically competitive and geared towards developing African nations with a housing deficit. The key point to the research of a modular wall solution is a structural layer complemented with local and materials made by non-specialized workforce. This wall also meets also hydrothermal acoustic and mechanical properties. Thus,the solution also offers good safety and interior comfort conditions to its users while maintaining the flexibility to expand the size of the house. Parameters as dimensions, materials and constructive processes of the existing housing stock were studied. Features such as the family size, typology, different uses, common materials, existing regulations, minimal living conditions, safety and comfort have also been considered to achieve the most efficient solution.
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Dissertação para obtenção do Grau de Doutor em Engenharia Química e Bioquímica
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Information technologies (ITs), and sports resources and services aid the potential to transform governmental organizations, and play an important role in contributing to sustainable communities development, respectively. Spatial data is a crucial source to support sports planning and management. Low-cost mobile geospatial tools bring productive and accurate data collection, and their use combining a handy and customized graphical user interface (GUI) (forms, mapping, media support) is still in an early stage. Recognizing the benefits — efficiency, effectiveness, proximity to citizens — that Mozambican Minister of Youth and Sports (MJD) can achieve with information resulted from the employment of a low-cost data collection platform, this project presents the development of a mobile mapping application (app) — m-SportGIS — under Open Source (OS) technologies and a customized evolutionary software methodology. The app development embraced the combination of mobile web technologies and Application Programming Interfaces (APIs) (e.g. Sencha Touch (ST), Apache Cordova, OpenLayers) to deploy a native-to-the-device (Android operating system) product, taking advantage of device’s capabilities (e.g. File system, Geolocation, Camera). In addition to an integrated Web Map Service (WMS), was created a local and customized Tile Map Service (TMS) to serve up cached data, regarding the IT infrastructures limitations in several Mozambican regions. m-SportGIS is currently being exploited by Mozambican Government staff to inventory all kind of sports facilities, which resulted and stored data feeds a WebGIS platform to manage Mozambican sports resources.
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Author's pre-print
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This thesis is one of the first reports of digital microfluidics on paper and the first in which the chip’s circuit was screen printed unto the paper. The use of the screen printing technique, being a low cost and fast method for electrodes deposition, makes the all chip processing much more aligned with the low cost choice of paper as a substrate. Functioning chips were developed that were capable of working at as low as 50 V, performing all the digital microfluidics operations: movement, dispensing, merging and splitting of the droplets. Silver ink electrodes were screen printed unto paper substrates, covered by Parylene-C (through vapor deposition) as dielectric and Teflon AF 1600 (through spin coating) as hydrophobic layer. The morphology of different paper substrates, silver inks (with different annealing conditions) and Parylene deposition conditions were studied by optical microscopy, AFM, SEM and 3D profilometry. Resolution tests for the printing process and electrical characterization of the silver electrodes were also made. As a showcase of the applications potential of these chips as a biosensing device, a colorimetric peroxidase detection test was successfully done on chip, using 200 nL to 350 nL droplets dispensed from 1 μL drops.
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INTRODUCTION: Leptospirosis is often mistaken for other acute febrile illnesses because of its nonspecific presentation. Bacteriologic, serologic, and molecular methods have several limitations for early diagnosis: technical complexity, low availability, low sensitivity in early disease, or high cost. This study aimed to validate a case definition, based on simple clinical and laboratory tests, that is intended for bedside diagnosis of leptospirosis among hospitalized patients. METHODS: Adult patients, admitted to two reference hospitals in Recife, Brazil, with a febrile illness of less than 21 days and with a clinical suspicion of leptospirosis, were included to test a case definition comprising ten clinical and laboratory criteria. Leptospirosis was confirmed or excluded by a composite reference standard (microscopic agglutination test, ELISA, and blood culture). Test properties were determined for each cutoff number of the criteria from the case definition. RESULTS: Ninety seven patients were included; 75 had confirmed leptospirosis and 22 did not. Mean number of criteria from the case definition that were fulfilled was 7.8±1.2 for confirmed leptospirosis and 5.9±1.5 for non-leptospirosis patients (p<0.0001). Best sensitivity (85.3%) and specificity (68.2%) combination was found with a cutoff of 7 or more criteria, reaching positive and negative predictive values of 90.1% and 57.7%, respectively; accuracy was 81.4%. CONCLUSIONS: The case definition, for a cutoff of at least 7 criteria, reached average sensitivity and specificity, but with a high positive predictive value. Its simplicity and low cost make it useful for rapid bedside leptospirosis diagnosis in Brazilian hospitalized patients with acute severe febrile disease.
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As the financial crisis hit the Portuguese banks, the profitability of the whole sector squeezed to historical minimums. Reinventing the banking business model in the post-crisis context is an overriding issue to achieve sustainable profits and a low cost-to-income ratio. We propose banks to adopt a true multichannel approach, proceeding to a branch network reformatting and a relocation of services to online channels; adopt a true customer-centric approach and reduce the product and services portfolio complexity; finally, industrialize operations and rationalize the structure. With these measures in place, Portuguese banks will become leaner and more efficient, aspiring to a cost-to-income ratio below 45%.