Metodologia para análise da dependabilidade de Smart Grids

Smart Grids are a new trend of electric power distribution, the future of current systems. These networks are continually being introduced in order to improve the reliability of systems, providing alternatives to energy supply and cost savings. Faced with increasing electric power grids complexity, the energy demand and the introduction of alternative sources to energy generation, all components of system require a fully integration in order to achieve high reliability and availability levels (dependability). The systematization of a Smart Grid from the Fault Tree formalism enable the quantitative evaluation of dependability of a specific scenario. In this work, a methodology for dependability evaluation of Smart Grids is proposed. A study of case is described in order to validate the proposal. With the use of this methodology, it is possible to estimate during the early design phase the reliability, availability of Smart Grid beyond to identify the critical points from the failure and repair distributions of components.

Análise experimental do consumo de um veículo flex operando com diferentes misturas de gasolina/etanol em tráfego urbano

This study is an analysis, on a trial basis, the fuel consumption of a Flex vehicle, operating with different mixtures of gasoline and ethanol in urban traffic, allowing more consistent results with the reality of the driver. Considering that most owners unaware of the possibility of mixing the fuel at the time of supply, thus enabling the choice of the most economically viable mixing gasoline / ethanol, resulting in lower costs and possibly a decrease in pollutant emission rates. Currently, there is a myth created by the people that supply ethanol only becomes viable if the value of not more than 70% of regular gasoline. However vehicles with this technology make it possible to operate with any percentage of mixture in the fuel tank, but today many of the owners of these vehicles do not use this feature effectively, because they ignore the possibility of mixing or the reason there is a deeper study regarding the optimal percentage of the mixture to provide a higher yield with a lower cost than proposed by the manufacturers.

Análise experimental do consumo de um veículo flex operando com diferentes misturas de gasolina/etanol em tráfego urbano

This study is an analysis, on a trial basis, the fuel consumption of a Flex vehicle, operating with different mixtures of gasoline and ethanol in urban traffic, allowing more consistent results with the reality of the driver. Considering that most owners unaware of the possibility of mixing the fuel at the time of supply, thus enabling the choice of the most economically viable mixing gasoline / ethanol, resulting in lower costs and possibly a decrease in pollutant emission rates. Currently, there is a myth created by the people that supply ethanol only becomes viable if the value of not more than 70% of regular gasoline. However vehicles with this technology make it possible to operate with any percentage of mixture in the fuel tank, but today many of the owners of these vehicles do not use this feature effectively, because they ignore the possibility of mixing or the reason there is a deeper study regarding the optimal percentage of the mixture to provide a higher yield with a lower cost than proposed by the manufacturers.

Modelagem e análise dinâmica de um sistema de conversão de energia eólica dotado de gerador síncrono de imã permanente utilizando a plataforma ATP

Human development requires a broad balance between ecological, social and economic factors in order to ensure its own sustainability. In this sense, the search for new sources of energy generation, with low deployment and operation costs, which cause the least possible impact to the environment, has been the focus of attention of all society segments. To do so, the reduction in exploration of fossil fuels and the encouragement of using renewable energy resources for distributed generation have proved interesting alternatives to the expansion of the energy matrix of various countries in the world. In this sense, the wind energy has acquired an increasingly significant role, presenting increasing rates of power grid penetration and highlighting technological innovations such as the use of permanent magnet synchronous generators (PMSG). In Brazil, this fact has also been noted and, as a result, the impact of the inclusion of this source in the distribution and sub-transmission power grid has been a major concern of utilities and agents connected to Brazilian electrical sector. Thus, it is relevant the development of appropriate computational tools that allow detailed predictive studies about the dynamic behavior of wind farms, either operating with isolated load, either connected to the main grid, taking also into account the implementation of control strategies for active/reactive power generation and the keeping of adequate levels of voltage and frequency. This work fits in this context since it comprises mathematical and computational developments of a complete wind energy conversion system (WECS) endowed with PMSG using time domain techniques of Alternative Transients Program (ATP), which prides itself a recognized reputation by scientific and academic communities as well as by electricity professionals in Brazil and elsewhere. The modeling procedures performed allowed the elaboration of blocks representing each of the elements of a real WECS, comprising the primary source (the wind), the wind turbine, the PMSG, the frequency converter, the step up transformer, the load composition and the power grid equivalent. Special attention is also given to the implementation of wind turbine control techniques, mainly the pitch control responsible for keeping the generator under the maximum power operation point, and the vector theory that aims at adjusting the active/reactive power flow between the wind turbine and the power grid. Several simulations are performed to investigate the dynamic behavior of the wind farm when subjected to different operating conditions and/or on the occurrence of wind intensity variations. The results have shown the effectiveness of both mathematical and computational modeling developed for the wind turbine and the associated controls.

A contabilidade de custos nas autarquias locais: o caso da Câmara Municipal de Pombal

Com a aprovação do POCAL e a sua entrada em vigor, as autarquias locais ficaram obrigadas a implementar um sistema de contabilidade de custos. A implementação da contabilidade de custos é vantajosa para as autarquias locais, pois permite-lhes obter informações relacionadas com os custos que ajudam os gestores nas suas tomadas de decisão. O sistema de contabilidade de custos tem como finalidade contribuir para a melhoria do processo de tomada de decisão, nomeadamente nas questões relacionadas com a determinação dos preços e das taxas, mas também através do controlo dos custos. Atualmente, as autarquias locais deparam-se com algumas dificuldades financeiras, pelo que a escassez de recursos financeiros se mostra uma realidade tendo em consideração o acréscimo das necessidades que são verificadas ao longo do ano. Assim, a implementação de um sistema de contabilidade de custos mostra-se de extrema importância, pois permite imputar os custos às funções que os consumiram e perceber quais as funções que não se estão a mostrar rentáveis, mas também ajuda na fixação de tarifas e preços de bens e serviços. Desta forma, a elaboração deste relatório de estágio permite, por um lado, descrever o funcionamento de um sistema de contabilidade de custos e o seu enquadramento e, por outro lado, perceber como é que o sistema se encontra implementado no município de Pombal.

Análise da disponibilidade da instrumentação nuclear de um reator de pesquisa

The maintenance of systems and equipment is a central question related to Production Engineering. Although systems are not fully reliable, it is often necessary to minimize the failure occurrence likelihood. The failures occurrences can have disastrous consequences during a plane flight or operation of a nuclear power plant. The elaboration of a maintenance plan has as objective the prevention and recovery from system failures, increasing reliability and reducing the cost of unplanned shutdowns. It is also important to consider the issues related to organizations safety, especially those dealing with dangerous technologies. The objective of this thesis is to propose a method for maintenance analysis of a nuclear research reactor, using a socio-technical approach, and focused on existing conditions in Brazil. The research reactor studied belongs to the federal government and it is located in the city of Rio de Janeiro. The specific objective of this thesis is to develop the availability analysis of one of the principal systems of the research reactor, the nuclear instrumentation system. In this analysis, were taken into account not only the technical aspects of the modules related to nuclear instrumentation system, but also the human and organizational factors that could affect the availability of the nuclear instrumentation system. The results showed the influence of these factors on the availability of the nuclear instrumentation system.

Cooperação e competição entre políticas no Brasil: os custos da governabilidade no presidencialismo de coalizão

Public policies have been studied in the various fields of humanities and social sciences, from different theoretical and technical aspects. However, there is still a lack of studies that incorporate the dimension that encompasses the political action and its interference in such actions, also recognizing the importance of the institutional setting of the Brazilian presidential model in implementing these policies. This fragmented and multiparty system has led to power heterogeneous sets of political parties. Thus, the ministerial offices, more than assisting the President´s government project, manage particularized agendas, which are party biased and have the influence of interest groups in hegemonic themes addressed by government agencies. When these agendas operate in sectoral and specialized policies, the friction level is apparently low. However, when this occurs in intersectoral actions, such as in regional development, there is evidence of strong signs of competition among government agencies, which in theory, should operate in an integrated manner. Although this is not a specific feature of Luiz Inacio Lula da Silva´s government- the period to be studied- there was similar behavior in Fernando Henrique Cardoso´s presidency, one realizes that the expansion of coalition on behalf of governance is increasingly interfering in the outcome of intersectoral public policies, due to these multiple arguments in action. In order to understand these processes, this study focused on the Sustainable and Integrated Development Programme for Differentiated Meso-Regions (PROMESO), part of the National Policy for Regional Development (NPRD). The program provides interface with various government agencies and their public policies in a clear intersectoral design. The research sought to identify and analyze the relationships between government agencies and their programs with interest groups, whether political parties or other segments of civil society, highlighting the logic of favoritism, which poses in second place the integration of actions in the intersectoral policies. Therefore, besides the theoretical debate that incorporates several categories of political science, public administration, public policy, geography and economics, the study focused on secondary sources, using different government agencies databases in order to raise information. It was observed that the interference of partisan politics has been disastrous for some public policies. Thus, the research confirms that cooperative character is fragile within government agencies, often limited to official documents, and that there is indeed, a striking feature of competition, especially when it comes to transversalized policies

Análise da eficiência de contratos de serviços de elevada especificidade terceirizados pela petrobras

The definition of the boundaries of the firms is subject that has occupied the organizational theorists long ago, being the seminal work of Coase (1937) indicated as the trigger for one theoretical evolution, with emphasis on governance structures, which led to a modern theory of incomplete contracts. The Transaction Cost Economics (TCE) and Agency Theory arise within this evolution, being widely used in studies related to the theme. Empirically, data envelopment analysis (DEA) has established itself as a suitable tool for analysis of efficiency. Although TCE argues that specific assets must be internalized, recent studies outside the mainstream of theory show that, often, firms may decide, for various reasons, hire them on the market. Researches on transaction costs face with the unavailability of information and methodological difficulties in measuring their critical variables. There`s still the need for further methodological deepening. The theoretical framework includes classic works of TCE and Agency Theory, but also more recent works, outside the mainstream of TCE, which warn about the existence of strategies in use of specific assets that aren`t necessarily aligned with the classical ideas of TCE. The Brazilian oil industry is the focus of this thesis, that aimed to evaluate the efficiency of contracts involving high specificity service outsourced by Petrobras. In order to this, we made the categorization of outsourced services in terms of specificity, as well the description of services with higher specificity. Then, we verified the existence of relationship between the specificity of services and a number of variables, being found divergent results than those that are preached by the mainstream of TCE. Then, we designed a DEA model to analyze the efficiency in the use of onshore drilling rigs, identified among the services of highest specificity. The next step was the application of the model to evaluate the performance of drilling rigs contracts. Finally, we verified the existence of relationship between the efficiency of contracts and a number of variables, being found, again, results not consistent with the theory mainstream. Regarding to analyze of efficiency of drilling rigs contracts, the model developed is compatible with what is found in academic productions in efficiency of drilling rigs. The results on efficiency show a wide range of scores, with efficiencies ranging from 31.79% to 100%, being low the sample efficiency average. There is consonance between the model results and the practices adopted by Petrobras. The results strengthen the DEA as an important tool in studies of efficiency with possibility to use for analysis other types of contracts. In terms of theoretical findings, the results reinforce the arguments that there are situations in which the strategies of the organizations, in terms of use of assets and services of high specificity, do not necessarily follow what is recommended by the mainstream of TCE

Análise da gestão da cadeia de suprimentos de um supermercado varejista através da utilização do modelo SCOR

In the last decade the complexity of the environment in which organizations are embedded increased dramatically, having on one side the increasingly demanding consumers in regard to the quality and value of the product and the other companies with the need to reduce operating costs in order to achieve greater profitability, without this there is a downturn in growth or market share powers. In this context the necessity of effectively structuring actions relating to the line with the operational work processes so that business objectives are achieved organizational strategic planning, ensuring the competitiveness of the organization. This study aims to analyze how you have made the management of the supply chain in a grocery retailer in the light of guidelines of Supply Chain Management by using the SCOR model. For realization of this study a survey was needed, classified according to their goals, exploratory and descriptive as to its procedure, document, field and case study. Thus, the processing of data will be qualitative merit, using the thematic categorical analysis of Bardin (1977). Thus, to obtain data interviews together the operational and strategic management of a company that was named Supermarket Omega were performed. After analyzing the information obtained is perceived that there is an effort of the organization enhance its management of the supply chain. However, there is a lack of alignment between the various areas that compose it. About their work processes, we stress that the focus of the company is still very directed on sailing than profitability, although it is undergoing a transformation in its organizational culture However, records the existence of many improvement projects in developing. Thus, it can be noticed that there is some consistency between the assumptions of the SCOR model and applied within the supply chain Omega Supermarket, although a greater effort to better align with the model still needs to be studied

Alimentos com e sem glúten: análise comparativa de preços de mercado

A doença celíaca é uma doença autoimune que se traduz numa sensibilidade alimentar crónica ao glúten, que ocorre em indivíduos geneticamente suscetíveis. Em consequência da ingestão de glúten o organismo desenvolve uma reação imunológica contra o próprio intestino. A dieta isenta de glúten é o único tratamento conhecido para esta patologia, adotada para toda a vida, deve ser rigorosa, completa, equilibrada e variada. O presente estudo pretende comparar preços entre categorias de produtos alimentares sem glúten e produtos equiparáveis com glúten. É também objetivo do estudo avaliar o impacto desta despesa no rendimento familiar associado ao cumprimento de uma dieta sem glúten e comparar os resultados da presente recolha de dados com um estudo anterior.

Análise do custo-benefício de sistemas de cobertas em edificações comerciais para o clima de Natal/RN visando eficiência energética

This research consists in studying the influence of the various type of construction systems of roofs with their energy efficiency as well as on the cost benefit for the commercial buildings on the temperatures condition of the city of Natal/RN. The main goal of this research is to analyze the cost benefit of the construction systems of roofs available on the market, taking into consideration the energy efficiency of the commercial buildings artificially air conditioned in order to be used by the projectors and to be adequated to the temperatures condition of the city of Natal/RN. The method of valuation of the cost benefit of roof systems consists in six steps: Features and simulation of the reference building; Analyze of sensitivity; Analyzes, features and simulation of alternatives of roof construction systems; Analyze of the cost of implementation; Analyze of the benefits of the alternatives comparing to the base case; And finally the analyze of the cost benefit. The model type chosen as reference was stores with pre molded buildings and system of roof with fiber ciment and ceiling . The thermal results showed the influence of the roof system on the energy efficiency of the building. The Final results of the simulations of the alternatives comes to a conclusion that the absortance is the variable that presents the best cost benefit relation and the reduction on the thermal transmittance still has limitations because of the high cost

Iluminação em ambientes fabris: otimização e análise técnica-e-económica

Esta Dissertação aborda a temática da eficiência energética em sistemas de iluminação fabris. Desde os primórdios da história da humanidade que a iluminação tem representado um papel importante. Não só garante condições de segurança, como começou por ser o intuito primordial das fogueiras pré-históricas, traduzindo-se num elemento de conforto. Atualmente seria impensável conceber as mais diversas atividades económicas e produtivas de um país sem iluminação. Nesse sentido a iluminação representa também um elemento fomentador de produtividade. Não é bem conhecido o impacto que a iluminação tem nos custos operacionais de uma unidade fabril. Principalmente por ser difícil de quantificar separadamente na fatura de eletricidade qual a percentagem correspondente à iluminação. Tipicamente estes custos podem ascender a 20% do orçamento global da autarquia em países desenvolvidos. Por esse motivo, o sector da iluminação tem investido esforço no sentido de promover melhores soluções de iluminação capazes de por um lado de satisfazer os requisitos do espaço a iluminar, e por outro propiciar soluções eficientes do ponto de vista energético. Estas soluções assentam essencialmente no uso de dispositivos mais eficientes (como por exemplo os LED´s ou as lâmpadas compactas fluorescentes) bem como em estratégias de controlo eficientes baseadas em dados sensoriais (como por exemplo deteção de movimento/presença). A combinação destas estratégias permite reduzir os consumos em cerca de 80% quando comparadas com soluções passivas. A empresa Amorim Cork Research Lda. é uma empresa prestadora de serviços ao universo das empresas da Corticeira Amorim, uma das maiores multinacionais de origem portuguesa. Teve origem no negócio da cortiça, em 1870, sendo hoje líder destacada no sector a nível mundial. Dada a dimensão da empresa e a sua subdivisão em várias Unidades Industriais com requisitos individuais, será expectável que a iluminação represente uma parte significativa da fatura de eletricidade. Atualmente, os vários setores encontram-se equipados com soluções de iluminação diferentes, na sua maioria empregando tecnologias passivas, noutros casos com dispositivos eficientes. Há algum interesse em migrar para soluções mais eficientes, em parte suportadas em DALI (com interface de comunicação PLC ou Zigbee).

Educação financeira no ensino médio: uma abordagem por meio da análise de produtos financeiros com ênfase em consórcios

This paper presents a differential approach of financial mathematics developed in high school, focusing on financial education. We seek through the insertion of texts, analysis of some financial products and by the interpretation of problems to contribute to the financial training of students. Aiming to make financial mathematics more attractive and accessible to the day-today, there are available for studies some practical tools like the citizen calculator which are available for computers and mobile phones. As well as spreadsheets and software Geogebra, that allow you to compare and analyze the financial costs of consortia, financing and financial applications,in addition to being allied in the preparation and control of personal and family budget. By applying the teaching sequence proposed in a nocturnal class of high school, we realized some difficulties that have limited the financial learning of math concepts.Yet identified progress regarding the financial education of students. These observations were made through qualitative and quantitative analysis from notes in the field diary and also answers given by students in specific form.