982 resultados para design basis accident
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Mathematical models and statistical analysis are key instruments in soil science scientific research as they can describe and/or predict the current state of a soil system. These tools allow us to explore the behavior of soil related processes and properties as well as to generate new hypotheses for future experimentation. A good model and analysis of soil properties variations, that permit us to extract suitable conclusions and estimating spatially correlated variables at unsampled locations, is clearly dependent on the amount and quality of data and of the robustness techniques and estimators. On the other hand, the quality of data is obviously dependent from a competent data collection procedure and from a capable laboratory analytical work. Following the standard soil sampling protocols available, soil samples should be collected according to key points such as a convenient spatial scale, landscape homogeneity (or non-homogeneity), land color, soil texture, land slope, land solar exposition. Obtaining good quality data from forest soils is predictably expensive as it is labor intensive and demands many manpower and equipment both in field work and in laboratory analysis. Also, the sampling collection scheme that should be used on a data collection procedure in forest field is not simple to design as the sampling strategies chosen are strongly dependent on soil taxonomy. In fact, a sampling grid will not be able to be followed if rocks at the predicted collecting depth are found, or no soil at all is found, or large trees bar the soil collection. Considering this, a proficient design of a soil data sampling campaign in forest field is not always a simple process and sometimes represents a truly huge challenge. In this work, we present some difficulties that have occurred during two experiments on forest soil that were conducted in order to study the spatial variation of some soil physical-chemical properties. Two different sampling protocols were considered for monitoring two types of forest soils located in NW Portugal: umbric regosol and lithosol. Two different equipments for sampling collection were also used: a manual auger and a shovel. Both scenarios were analyzed and the results achieved have allowed us to consider that monitoring forest soil in order to do some mathematical and statistical investigations needs a sampling procedure to data collection compatible to established protocols but a pre-defined grid assumption often fail when the variability of the soil property is not uniform in space. In this case, sampling grid should be conveniently adapted from one part of the landscape to another and this fact should be taken into consideration of a mathematical procedure.
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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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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Química e Biológica
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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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The design of magnetic cores can be carried out by taking into account the optimization of different parameters in accordance with the application requirements. Considering the specifications of the fast field cycling nuclear magnetic resonance (FFC-NMR) technique, the magnetic flux density distribution, at the sample insertion volume, is one of the core parameters that needs to be evaluated. Recently, it has been shown that the FFC-NMR magnets can be built on the basis of solenoid coils with ferromagnetic cores. Since this type of apparatus requires magnets with high magnetic flux density uniformity, a new type of magnet using a ferromagnetic core, copper coils, and superconducting blocks was designed with improved magnetic flux density distribution. In this paper, the designing aspects of the magnet are described and discussed with emphasis on the improvement of the magnetic flux density homogeneity (Delta B/B-0) in the air gap. The magnetic flux density distribution is analyzed based on 3-D simulations and NMR experimental results.
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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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Trabalho de Projeto apresentado ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Auditoria Orientação: Doutora Alcina Augusta de Sena Portugal Dias Coorientação: Doutora Amélia Cristina Ferreira Silva
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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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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.
Impact of design options in zero energy building conception: the case of large buildings in Portugal
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The new recast of Directive 2010/31/EU in order to implement the new concept NZEB in new buildings, is to be fully respected by all Member States, and is revealed as important measure to promote the reduction of energy consumption of buildings and encouraging the use of renewable energy. In this study, it was tested the applicability of the nearly zero energy building concept to a big size office building and its impact after a 50-years life cycle span.
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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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Trabalho de Projeto submetido à Escola Superior de Teatro e Cinema para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Teatro - especialização em Design de Cena.