967 resultados para Concept Design


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Volatile organic compounds are a common source of groundwater contamination that can be easily removed by air stripping in columns with random packing and using a counter-current flow between the phases. This work proposes a new methodology for column design for any type of packing and contaminant which avoids the necessity of an arbitrary chosen diameter. It also avoids the employment of the usual graphical Eckert correlations for pressure drop. The hydraulic features are previously chosen as a project criterion. The design procedure was translated into a convenient algorithm in C++ language. A column was built in order to test the design, the theoretical steady-state and dynamic behaviour. The experiments were conducted using a solution of chloroform in distilled water. The results allowed for a correction in the theoretical global mass transfer coefficient previously estimated by the Onda correlations, which depend on several parameters that are not easy to control in experiments. For best describe the column behaviour in stationary and dynamic conditions, an original mathematical model was developed. It consists in a system of two partial non linear differential equations (distributed parameters). Nevertheless, when flows are steady, the system became linear, although there is not an evident solution in analytical terms. In steady state the resulting ODE can be solved by analytical methods, and in dynamic state the discretization of the PDE by finite differences allows for the overcoming of this difficulty. To estimate the contaminant concentrations in both phases in the column, a numerical algorithm was used. The high number of resulting algebraic equations and the impossibility of generating a recursive procedure did not allow the construction of a generalized programme. But an iterative procedure developed in an electronic worksheet allowed for the simulation. The solution is stable only for similar discretizations values. If different values for time/space discretization parameters are used, the solution easily becomes unstable. The system dynamic behaviour was simulated for the common liquid phase perturbations: step, impulse, rectangular pulse and sinusoidal. The final results do not configure strange or non-predictable behaviours.

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The objective of this contribution is to extend the models of cellular/composite material design to nonlinear material behaviour and apply them for design of materials for passive vibration control. As a first step a computational tool allowing determination of optimised one-dimensional isolator behaviour was developed. This model can serve as a representation for idealised macroscopic behaviour. Optimal isolator behaviour to a given set of loads is obtained by generic probabilistic metaalgorithm, simulated annealing. Cost functional involves minimization of maximum response amplitude in a set of predefined time intervals and maximization of total energy absorbed in the first loop. Dependence of the global optimum on several combinations of leading parameters of the simulated annealing procedure, like neighbourhood definition and annealing schedule, is also studied and analyzed. Obtained results facilitate the design of elastomeric cellular materials with improved behaviour in terms of dynamic stiffness for passive vibration control.

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Impact Assessment and Project Appraisal, vol. 22, n.1, March 2004, p. 47–62

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RESUMO - O aumento da incidência das doenças crónicas representa um desafio enorme para todos os Sistemas de Saúde, pelo que a assistência de Saúde a doentes crónicos se tornou num problema das sociedades ocidentais. Os países mais pobres são os que mais sofrem, embora nos países desenvolvidos também se verifique um aumento notável das doenças crónicas. Estima-se que estas representem mais de 60% do total das doenças mundiais no ano 2020 (WHO, 2001). A adaptação dos actuais modelos de saúde aos doentes crónicos não atingiu os objectivos, o que conduziu a que, de há alguns anos a esta parte, se procure alternativas mais eficazes e eficientes. Uma das pressões do mercado que se fazem sentir será caracterizada por uma maior aposta na Promoção da Saúde e Prevenção da doença. O conceito de “Saúde” migrou de “não existência de doença” para “Bem-estar Físico e Psicológico”. Desta forma, o foco dos cuidados de saúde teve que ser adaptado, o que conduziu a uma situação em que o âmbito da prestação de cuidados de saúde é um contínuo de serviços que vai desde a promoção da saúde, medicina preventiva e medicina curativa aos cuidados continuados e cuidados paliativos. As tecnologias de informação e comunicação desempenharão um importante papel nesta tendência, permitindo estabelecer ligações contínuas entre os consumidores e prestadores de cuidados de saúde. Por outro lado, as potencialidades da Internet, das comunicações móveis, dispositivos portáteis e do instrumental electrónico, tornam-se evidentes no desenvolvimento de serviços de e-Saúde: para monitorização, seguimento e controlo dos doentes extra hospitalar - serviços estes centrados no doente. O objectivo geral do presente estudo consiste no desenho de um projecto de investigação para posterior avaliação da percepção do estado de saúde dos doentes seguidos na consulta de hipocoagulação do Hospital de Santa Marta. Devido à escassez de investigação na temática deste trabalho em Portugal, procedeu-se a um trabalho exploratório, descritivo, de carácter comparativo e enquadrado na abordagem quantitativa. O campo de análise consiste em comparar doentes que fazem anticoagulação oral, seguidos na consulta de cardiologia (consulta convencional), com os doentes seguidos no programa Airmed (através das comunicações móveis). 4 Para avaliação da percepção do estado de saúde foi utilizado o questionário SF-36.----ABSTRACT - The increasing incidence of chronic diseases represents an enormous challenge to the Health Systems and on cause of that, the Health Assistance to chronic patients became a concern of the Occidental society. The Countries with lower economical resources are the ones that suffers the most, but also the Developed countries have a noticeable increase of chronic diseases. It is estimated these will represent over 60% of total diseases world wide in 2020 (WHO,2001). The adaptation of the actual Health Models to chronic patients did not achieved it’s goals, what leaded to look for more effective and efficient alternatives. One of the more sensitive market pressure factor is to look for a better Health Promotion and Disease Prevention. The concept of “Health” merged from “Disease absence” to “Physic and Psychic Wellness”. In this way the Health Care focus had to be adapted, what drove to a status where the scope of the Health care is a continuum of services that goes from the Health Promotion, Preventive and Curative to Continued and Palliative Medical Care. The Information and Communication Technologies will play a crucial role in this trend, allowing to establish continued connections between patients and Health Care providers. In parallel the potential of the Internet, mobile communications, portable devices and electronic instruments became evident to deploy e-Health services: to monitor, follow-up and control of patients outside the Hospital. The overall objective of the present study is an Investigation Project Design to further evaluate the health status perception of the patients followed in the consultation for Hypocoagulation in the “Hospital de Santa Marta”. Due to lack of investigation in this thematic, in Portugal, this study is developed in an exploratory way, descriptive, comparative, within a scope of a quantified approach. The analysis field consists on comparing patients prescribed with oral anticoagulants and followed-up at the

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This paper is about a design of an urban area Darrieus VAWT, having self-start ability due to an innovative profile design named EN0005, avoiding the need of extra components or external electricity feed-in. An approach is presented to study the ability of a blade profile to offer self-start ability. Methodologies applied for the blade body and for profile development are reported. Field tests and main conclusions are presented to persuade for the arrangement of this design. (C) 2015 Elsevier Ltd. All rights reserved.

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Recent integrated circuit technologies have opened the possibility to design parallel architectures with hundreds of cores on a single chip. The design space of these parallel architectures is huge with many architectural options. Exploring the design space gets even more difficult if, beyond performance and area, we also consider extra metrics like performance and area efficiency, where the designer tries to design the architecture with the best performance per chip area and the best sustainable performance. In this paper we present an algorithm-oriented approach to design a many-core architecture. Instead of doing the design space exploration of the many core architecture based on the experimental execution results of a particular benchmark of algorithms, our approach is to make a formal analysis of the algorithms considering the main architectural aspects and to determine how each particular architectural aspect is related to the performance of the architecture when running an algorithm or set of algorithms. The architectural aspects considered include the number of cores, the local memory available in each core, the communication bandwidth between the many-core architecture and the external memory and the memory hierarchy. To exemplify the approach we did a theoretical analysis of a dense matrix multiplication algorithm and determined an equation that relates the number of execution cycles with the architectural parameters. Based on this equation a many-core architecture has been designed. The results obtained indicate that a 100 mm(2) integrated circuit design of the proposed architecture, using a 65 nm technology, is able to achieve 464 GFLOPs (double precision floating-point) for a memory bandwidth of 16 GB/s. This corresponds to a performance efficiency of 71 %. Considering a 45 nm technology, a 100 mm(2) chip attains 833 GFLOPs which corresponds to 84 % of peak performance These figures are better than those obtained by previous many-core architectures, except for the area efficiency which is limited by the lower memory bandwidth considered. The results achieved are also better than those of previous state-of-the-art many-cores architectures designed specifically to achieve high performance for matrix multiplication.

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This paper presents the design of low-cost, conformal UHF antennas and RFID tags on two types of cork substrates: 1) natural cork and 2) agglomerate cork. Such RFID tags find an application in wine bottle and barrel identification, and in addition, they are suitable for numerous antenna-based sensing applications. This paper includes the high-frequency characterization of the selected cork substrates considering the anisotropic behavior of such materials. In addition, the variation of their permittivity values as a function of the humidity is also verified. As a proof-of-concept demonstration, three conformal RFID tags have been implemented on cork, and their performance has been evaluated using both a commercial Alien ALR8800 reader and an in-house measurement setup. The reading of all tags has been checked, and a satisfactory performance has been verified, with reading ranges spanning from 0.3 to 6 m. In addition, this paper discusses how inkjet printing can be applied to cork surfaces, and an RFID tag printed on cork is used as a humidity sensor. Its performance is tested under different humidity conditions, and a good range in excess of 3 m has been achieved, allied to a good sensitivity obtained with a shift of >5 dB in threshold power of the tag for different humid conditions.

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RESUMO - Este trabalho de projecto visa responder à questão de saber como gerir uma unidade de ética num serviço público central de saúde pública, “de forma racional e informada”, definindo os seus objectivos estratégicos (Baranger, citando Drucker, 1990) utilizando como caso de estudo o Gabinete de Assuntos Jurídicos, Ética e Responsabilidade, adiante designado por Gabinete, da Direcção‐Geral da Saúde. Para o efeito, fez‐se, em primeiro lugar, uma abordagem teórica descritiva das bases filosóficas da ética realçando a sua aplicação prática na determinação das características dos sistemas de saúde. Em seguida, analisa‐se a utilização do conceito de ética no âmbito da Saúde Pública, no contexto da bioética, verificando‐se elementos distintivos que parecem justificar a autonomização do conceito de ‘Ética em Saúde Pública’. Para tal, foram consultadas as principais fontes de princípios éticos em saúde, tais como a Declaração Universal dos Direitos do Homem, a Declaração de Helsínquia, bem como a Constituição da República Portuguesa e os Códigos Deontológicos das profissões de saúde. Nesta fase do trabalho é pesquisada, nas perspectivas nacional e internacional, a existência de unidades de ética, congéneres ou de âmbito similar, bem como respectivas áreas e níveis de intervenção, tendo‐se nesse sentido auscultado as entidades idóneas dos Estados‐Membros da União Europeia. Na segunda parte do trabalho de projecto, desenvolveu‐se o planeamento estratégico através da aplicação da metodologia balanced scorecard, apresentando‐se uma proposta de objectivos estratégicos e iniciativas a serem desenvolvidas pelo gabinete de ética sub judice, para um horizonte temporal fixado em três anos. Da utilização desta metodologia resultaram doze objectivos estratégicos, dos quais se destacam: ‘fomentar a discussão ética’; ‘promover a igualdade dos utentes do SNS’; e ‘identificar prioridades de actuação’. Entre as iniciativas a desenvolver salienta‐se o desenho de um questionário, a aplicar às comissões de ética do sistema de saúde com o objectivo de identificar prioridades de actuação do Gabinete. O trabalho finaliza‐se com as conclusões, recomendações e linhas de investigação que se considera deverem ser desenvolvidas, num futuro próximo, para o aprofundamento da matéria alvo deste estudo. ------------------ABSTRACT - This research‐project aims to answer the question of how to manage a unit of ethics within the directorate‐general of public health in a "rational and informed” way, defining their strategic goals (Baranger, quoting Drucker, 1990) using as case study the Office of Legal Affairs, Ethics and Responsibility, hereinafter referred as the Office, of the Directorate‐General of Health. For this purpose, the first part of the study, includes a framework description of the main philosophical basis of ethics, emphasizing that its practical application determines the characteristics of health systems; the use of the concept of ethics of Public Health in the context of bioethics was analyzed, and distinctive elements were found that seem to justify the autonomy of the concept of 'Ethics of Public Health'. The main sources of this part were the fundamental ethical principles in health, such as the Universal Declaration of Human Rights, the Helsinki Declaration, and also the Constitution of the Portuguese Republic and the Codes of Ethics of the health professions. At this stage of the study a description is also made, at both a national and international perspective, on the existence of similar units of ethics or with similar scope, and their areas and levels of intervention. For the international dimension the appropriate bodies of the Member States the European Union were consulted. In the second part of the research‐project, a strategic planning for the Office was designed, using the balanced scorecard methodology, and a proposal of the strategic objectives and initiatives to be developed within a time schedule of three years are presented. The use of this method resulted in twelve strategic objectives, among which we note the following: 'to promote the ethical discussion'; 'to promote equality of users of the NHS'; and ‘to identify priorities for action’. The design of a questionnaire to be answered by the ethics committees for health of the Portuguese health system, in order to identify priorities for the Office’s activities is also presented in the study. The work ends with the conclusions and recommendations, as well as a suggestion of lines for future research to further investigate the subject of this study.

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Demand response can play a very relevant role in the context of power systems with an intensive use of distributed energy resources, from which renewable intermittent sources are a significant part. More active consumers participation can help improving the system reliability and decrease or defer the required investments. Demand response adequate use and management is even more important in competitive electricity markets. However, experience shows difficulties to make demand response be adequately used in this context, showing the need of research work in this area. The most important difficulties seem to be caused by inadequate business models and by inadequate demand response programs management. This paper contributes to developing methodologies and a computational infrastructure able to provide the involved players with adequate decision support on demand response programs and contracts design and use. The presented work uses DemSi, a demand response simulator that has been developed by the authors to simulate demand response actions and programs, which includes realistic power system simulation. It includes an optimization module for the application of demand response programs and contracts using deterministic and metaheuristic approaches. The proposed methodology is an important improvement in the simulator while providing adequate tools for demand response programs adoption by the involved players. A machine learning method based on clustering and classification techniques, resulting in a rule base concerning DR programs and contracts use, is also used. A case study concerning the use of demand response in an incident situation is presented.

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Trihalomethanes (THMs) are widely referred and studied as disinfection by-products (DBPs). The THMs that are most commonly detected are chloroform (TCM), bromodichloromethane (BDCM), chlorodibromomethane (CDBM), and bromoform (TBM). Several studies regarding the determination of THMs in swimming pool water and air samples have been published. This paper reviews the most recent work in this field, with a special focus on water and air sampling, sample preparation and analytical determination methods. An experimental study has been developed in order to optimize the headspace solid-phasemicroextraction (HS-SPME) conditions of TCM, BDCM, CDBM and TBM from water samples using a 23 factorial design. An extraction temperature of 45 °C, for 25min, and a desorption time of 5 min were found to be the best conditions. Analysis was performed by gas chromatography with an electron capture detector (GC-ECD). The method was successfully applied to a set of 27 swimming pool water samples collected in the Oporto area (Portugal). TCM was the only THM detected with levels between 4.5 and 406.5 μg L−1. Four of the samples exceeded the guideline value for total THMs in swimming pool water (100 μgL−1) indicated by the Portuguese Health Authority.

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Dissertação de Mestrado em Ciências da Comunicação Cultura Contemporânea e Novas Tecnologias

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This paper describes preliminary work on the generation of synthesis gas from water electrolysis using graphite electrodes without the separation of the generated gases. This is an innovative process, that has no similar work been done earlier. Preliminary tests allowed to establish correlations between the applied current to the electrolyser and flow rate and composition of the generated syngas, as well as a characterisation of generated carbon nanoparticles. The obtained syngas can further be used to produce synthetic liquid fuels, for example, methane, methanol or DME (dimethyl ether) in a catalytic reactor, in further stages of a present ongoing project, using the ELECTROFUEL® concept. The main competitive advantage of this project lies in the built-in of an innovative technology product, from RE (renewable energy) power in remote locations, for example, islands, villages in mountains as an alternative for energy storage for mobility constraints.

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Recent studies have shown that, besides the well-recognized T3 and T4 hormones, there are other relevant thyroid hormones circulating in the human body. In particular, this is the case for 3-iodothyronamine (T1AM) and thyronamine (T0AM). One of the reasons for the lack of studies showing their precise importance is the absence of analytical methodologies available. Herein, for the first time, T1AM and T0AM are electrochemically characterized. T0AM was sensed by means of a glassy carbon electrode; furthermore, T1AM was sensed both with a graphitic surface (oxidatively) as well as with mercury (reductively). For both compounds, after oxidation, it was possible to observe the reversible redox reaction concerning the benzoquinone/hydroquinone couple, thus increasing the specificity of the electroanalysis. Therefore, this work provides the basis for an ‘at-point-of-use’ electrochemical strip test for T1AM and T0AM.

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This paper presents the design and implementation of direct power controllers for three-phase matrix converters (MC) operating as Unified Power Flow Controllers (UPFC). Theoretical principles of the decoupled linear power controllers of the MC-UPFC to minimize the cross-coupling between active and reactive power control are established. From the matrix converter based UPFC model with a modified Venturini high frequency PWM modulator, decoupled controllers for the transmission line active (P) and reactive (Q) power direct control are synthesized. Simulation results, obtained from Matlab/Simulink, are presented in order to confirm the proposed approach. Results obtained show decoupled power control, zero error tracking, and fast responses with no overshoot and no steady-state error.

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Modular design is crucial to manage large-scale systems and to support the divide-and-conquer development approach. It allows hierarchical representations and, therefore, one can have a system overview, as well as observe component details. Petri nets are suitable to model concurrent systems, but lack on structuring mechanisms to support abstractions and the composition of sub-models, in particular when considering applications to embedded controllers design. In this paper we present a module construct, and an underlying high-level Petri net type, to model embedded controllers. Multiple interfaces can be declared in a module, thus, different instances of the same module can be used in different situations. The interface is a subset of the module nodes, through which the communication with the environment is made. Module places can be annotated with a generic type, overridden with a concrete type at instance level, and constants declared in a module may have a new value in each instance.