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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

[pt] IMPACTOS DA IMPLANTAÇÃO DO TELEFÉRICO COMO SISTEMA DE TRANSPORTE NAS FAVELAS: O CASO DO COMPLEXO DO ALEMÃO / [en] IMPACTS OF THE DEPLOYMENT OF CABLE CAR AS TRANSPORT IN SLUMS: THE CASE OF THE COMPLEXO DO ALEMÃO

29 October 2021 (has links)
[pt] Esta pesquisa disserta sobre as soluções de mobilidade urbana em favelas de encostas como parte integrante do planejamento urbano, tendo como foco a implantação do sistema de transporte teleférico e como estudo de caso, o teleférico do Complexo do Alemão. Inicialmente é apresentado um panorama histórico das intervenções do poder público nas favelas do Rio de Janeiro e como se desenvolveu a mobilidade urbana nessas áreas. Em seguida, é exposto o problema da mobilidade nas favelas e a implantação de equipamentos alternativos de transportes. Os Projetos de implantação do teleférico Metrocable em Medellín, o teleférico de San Augustín em Caracas, o teleférico do morro da Providência e o projeto para o teleférico da favela da Rocinha são expostos como exemplos desse sistema. No Estudo de caso, foram analisados os impactos da implantação do teleférico no Complexo do Alemão, sua eficiência e principalmente, os custos de execução, operação e os custos sociais. Considera-se que o impacto estudado é moldado por análises contextuais, avaliações empíricas de visitas ao local, entrevistas com os moradores e usuários do sistema em questão, conteúdos bibliográficos e análise de indicadores. / [en] This research is on urban mobility solutions in favelas (slums) on hills as an integral part of urban planning. With a focus on the implementation of cable cars as transport systems, this research examines the cable car of the Complexo do Alemão as a case study which is located on the north side of the city of Rio de Janeiro. In Chapter 1, the research outlines the problem of poverty and absence of urban planning in Brazilian cities, which has intensified since the 1950s because of the rapid influx of migrants in search for work in the great economic city centers. Currently in Rio de Janeiro, 22 per cent of the population lives in favelas. The population of the favelas grew disproportionally in the last two decades, four times more than the population of the officially recognized areas of the city. The problem of housing in the favelization process of the city is aggravated by poor sanitation, violent conflicts, problems with security and safety, a lack of public services, poor access, precarious urban mobility, irregular services like illegal connections to electricity, among other problems. Additionally, there is the overarching problem of urban mobility. Spatial segregation makes it difficult for low-income populations to move from one place to another and is mainly due to the historical selection of occupations in isolated and peripheral areas of the city. The problem of mobility is further aggravated by underdeveloped transitional areas between the rural and urban parts of the city especially when, like in the case of this research, those populations occupy areas with steep hills. The chapter continues by tracing a history of public policies affecting the favelas of Rio de Janeiro, from the first removal of tenement houses in the city center in the nineteenth century, to the developmental policies of today. The chapter follows the formation of the first favelas with an occupation organized by the people who were removed from tenement houses and who needed to live near the economic city centers, the eventual expansion to other areas, the first removal policies for temporary housing and subsequently a more rigid posture of the state in regard to favelas. The 1960s and 1970s were periods marked by the removal and political denial of favelas, it was only in the 1980s that the state began to provide public policies to improve favelas. Thus, there has been a gradual acceptance of these occupations in the landscape of the city. Beyond the social problems aforementioned, Chapter 2 points more specifically to the problems of mobility in favelas on hills because of high building density, risks of landslides and precarious road access. In Rio de Janeiro, the state started to intervene in regard to the issue of mobility in favelas during the first term of Leonel Brizola (1983-1987), with the construction of the Inclined Plane in the Pavão Pavãozinho favela. But it was not until the Favela Bairro program that mobility initiatives were executed on a much wider scale, the program initiated walkways and improved stairs which greatly increased accessibility and the flow of traffic on road networks. With an urbanization policy for favelas in motion, other urban mobility transport systems were established, like the inclined plane on the Hill of Santa Marta in 2008 and the elevator of Cantagalo in 2010. While these transport systems assert the presence of the state in marginal communities, the daily transportation of the residents are mainly local options like vans and motorcycle taxis which continue to play a fundamental role and also contribute to the local economy. This generates income for residents because many of the people working with this type of transport also live in the favelas. The chapter then describes cable car technology and looks at specific examples of cable cars built or planning to be built in the favelas of Latin America. The lines of Medellin are used as an example because they inspired so many others like San Agustín in Caracas, Complexo do Alemão in Rio de Janeiro, Providencia in Rio de Janeiro and the cable car project of Rocinha in Rio de Janeiro. The city of Medellin for many years suffered from violence generated by drug trafficking and came to be known in the early 90s as one of the most violent cities in the world. The high murder rate and violence receded after a series of investments that occurred in the city, mainly investments towards urbanization, education and security. The urban planning of Medellin was based on major public interventions through specific projects in the poorest sectors of the city. Initially structured around the cable cars, called Metrocables, and spatially articulated with other projects extended to formal sectors of the city, known as Urban Integral Projects (Proyectos Urbanos Integrales-PUIs), the aim of these initiatives was to connect various urban spaces. One of the characteristics of these projects was the emphasis on aesthetics as an engine for social change. This aesthetic quality to the new cable cars resulted in an increase of residents self-esteem but was also criticized for its stark contrast with poor local reality. In 2004, the Line K of the cable car was constructed in Comunas 1 and 2, and initiated an urban planning of the city based on the theory of Social Urbanism, with several projects aimed at improving infrastructure and education in favelas. In 2010, Line K was supplemented by a transfer to the Line L, which goes to the Arvi Park, an ecological park created on the border of a green area to Comuna 1, stimulating tourism. There is also Line J which meets Comunas 7 and 13, inaugurated in 2008. Medellín has become a model for other cities to adopt the cable car system for transportation in favelas. One example was the cable car of San Agustín in Caracas, designed as an important integrator between the favela and the rest of the city. In January 2010, the system started was connected to the subway. In contrast to Medellin, the Metrocable system in Caracas is characterized with large stations that integrate cultural facilities, sports arenas, and shopping centers together in one convenient location. The estimated daily demand during the planning stages of the project was 15 thousand passengers. Approximately 40,000 people live in San Augustin which means that the demand estimate would amount to 37.5 per cent of the residents. The data in 2012 showed that only 4,500 passengers use the system daily, about three times less than expected, showing that the cable car, which cost 318 million dollars, is being underutilized. In Rio de Janeiro, in the favela Morro da Providência, there is a cable car built and because the favela is considered the first favela in Rio, current projects by the municipal government show that there is interest in promoting tourism and to integrate it with the dynamics of cultural and historical revitalization of the port area and the cable car is the vehicle proposed for this purpose. However, the Hill of Providence (Morro da Providência) is suffering from forced evictions, mainly due to the Morar Carioca project, an urban program of the city government. These interventions have not been discussed with the residents and involve the demolition of nearly half of the residences. The idea is to replace the residences with a historical and cultural center in the favela. According to the city administration, about 42 houses block, in the context of urban landscape, the view of the chapel located at the highest point of the hill and thus those 42 houses would have to be removed. Although the construction of the cable car has also caused the removal of a few houses, its implementation is linked more with tourism in the favela. Various resident led protests organized with activists and supported by critical news sources released in Brazil and abroad, put the Hill of Providence in the spotlight as an example of the negative impact of mega-events on the poor. Consequently, after the injunction obtained in a lawsuit, the projects in the community are at a standstill and the houses that were scheduled to be removed remain standing. In Rocinha, the PAC 2 (Accelerating Growth Program is a federal program that has as the main objective the development of the country through the planning and execution of large urban infrastructure, works in the transportation sector and the energy sector) provides for the cable car installation, an elevator, escalators, and other mobility infrastructure. This project is very controversial because the cable car project has an estimated budget of 700 million reais, an amount that would consume approximately 44 per cent of the total amount available for the PAC 2. Most debate is on the residents priorities, which if considered would require that the funds be applied to the sanitation of the favela, which the current project does not guarantee. In the project under study, the cable car will connect to the future subway station of Line 4 in São Conrado to the top of the favela and have 6 stations distributed in two lines, 2,500 meters long. This would be the third cable car built in the favelas of the city, reflecting a state trend to adopt this transportation method in favelas. It seems that cable cars are more than a modal of mass transport, but also as a way to enter favelas as a new tourist attraction of the city. In Chapter 3, the case study is presented about the cable car of Complexo do Alemão, an integral part of PAC. The cable car was built with 3.4 km in length, 152 cabins half of which are in regular operation, while the other half is parked. The system has six stations and the capacity to carry 30,000 passengers daily. The path between the first transfer station with the train, the Bonsucesso Station, and the last stop, the Palmeiras Station, is traversed in about 20 minutes. Using other means of transport, the time to travel the distance between these two places is about 40 minutes. The six stations are located on the tops of hills that form the intricacies of the favelas and therefore, many residents complain about the accessibility of the system. For those who live far away and do not see advantage in climbing the hill to use the system, it is more common to use van or motorcycle taxis to move around. This is the main reason that the cable car is underused even though residents are entitled to two free trips per day. According to the Supervia, which operates the system, the daily movement of people is about 10,000 to 11,000 people, but, as we reported, the equipment has been design for a capacity of 30,000 passengers per day. The construction of the cable car cost the government R$ 210 million, equivalent to 22.35 per cent of the total PAC work in Complexo do Alemão, and the operating cost is about 50.1 million reais a year. What we can conclude is that the cable car has a relatively high operating cost for low use by residents, and it is also expensive to build. The high investment in the cable car is not justified when there are still major problems to be solved in favelas. One of the main complaints made by residents is the lack of investments in priority areas, such as basic sanitation. As part of this research a survey was given to 50 residents. When asked if the resources used to cable car execution, being very high, could be implemented in other areas, 74 per cent said yes. Among the responses on areas where resources should be invested, they pointed mainly to sanitation, health and education. Some health problems in the favelas worsened while tourism has increased with the use of the cable car. Also according to the data from the Supervia, the percentage of passengers with gratuities, i.e. registered residents using the cable car during the week is 75 per cent and the percentage of those who paid the fare, mostly tourists, is 25 per cent. On weekends, the number of visitors almost doubled: 54 per cent of gratuities and 46 per cent of tourists. The cable car has always had a tourist appeal due to its comfort and excitement by offering the experience of getting a suspended adventure of great heights with a privileged view of the favela landscape. This also happens with the cable car of the Complexo do Alemão, but in another context, within a patrimonialization effort of those spaces. The research makes clear that even with the difficulties within a space precariously built, mobility solutions that were initially created by the residents are still the most used, for example, the alternative transport system like vans and motorcycle taxis. To establish that the cable car is the solution for urban mobility on slopes of slums is quite questionable, as each case requires a specific and detailed study. In the case of the Complexo do Alemão, for example, both positive and negative factors were found. On the one hand the cable car considerably reduced the Bonsucesso travel time to some community points and provided connection with the train, on the other, the number of users contained does not justify its high cost. It is also clear that the general population in favelas want more primary rights met like access to health care, the installation of sewer systems, and competent schools as their priority.
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[en] ASSESSMENT OF THE MOBILITY OF ELEMENTAL CONTAMINANTS AND ENVIRONMENTAL IMPACTS DUE TO THE INAPPROPRIATE DISPOSAL OF FLUORESCENT LAMPS / [pt] AVALIAÇÃO DA MOBILIDADE DE CONTAMINANTES ELEMENTARES E IMPACTOS AMBIENTAIS DEVIDO AO DESCARTE INAPROPRIADO DE LÂMPADAS FLUORESCENTES

LAIS NASCIMENTO VIANA 07 August 2023 (has links)
[pt] Embora as lâmpadas fluorescentes (LF) estejam sendo substituídas por LED (diodo emissor de luz), a maioria das LF é descartada de forma inadequada e as taxas de reciclagem ainda são, em geral, baixas (4 por cento na China, 5 por cento no Brasil, 7 por cento no Canadá, menor que 10 por cento no Japão). Por causa da sua composição, as LF podem causar um impacto ambiental significativo. Assim, no presente estudo empregamos diferentes técnicas analíticas com o objetivo de caracterizar o material fosfórico bruto de LF, quantificar os elementos mobilizados por soluções de chorume e chuva ácida sintéticas, e avaliar os impactos ambientais relacionados ao descarte das lâmpadas através de análise de ciclo de vida (LCA) para o cenário da cidade do Rio de Janeiro. A análise do material bruto por fluorescência e difração de raios X (FRX e DRX) aponta uma composição de fases sólidas complexa, com predominância de Ca, P e Al, presença de elementos terras raras, As e outros. Através da extração ácida auxiliada por micro-ondas, concentrações em massa de 0,1 até 16,5 por cento foram encontradas para Al, Ba, Ce, Eu, La, Mn, P, Sr e Y no material bruto, e mais de 700 mg kg-1 de Hg. As lixiviações com as soluções sintéticas foram realizadas com e sem agitação, partindo de 0,6 g de amostra, 1 mL das soluções, e 3 h de exposição. O ensaio produziu a mobilização de diversos elementos com concentrações atingindo 23,5 mais ou menos 0,4 mg kg-1 (Hg) na chuva ácida, e 34,0 mais ou menos 1,0 mg kg-1 (Sr) no chorume. Devido à periculosidade de alguns elementos, as quantidades extraídas, apesar de baixas, são preocupantes, e lixiviações consecutivas, comuns num cenário real de descarte, podem agravar a situação. A análise de ciclo de vida apontou que as lâmpadas geram maiores impactos ambientais nas categorias de ecotoxicidade terrestre, toxicidade humana não-carcinogênica, potencial de aquecimento global e esgotamento de recursos fósseis. A análise indicou que o aumento das taxas de reciclagem pode reduzir em 70 a 90 por cento a maioria dos impactos ao meio ambiente. / [en] Although fluorescent lamps (FL) are being replaced by LED (light emitting diode), most FL are disposed of improperly and recycling rates are still generally low (4 percent in China, 5 percent in Brazil, 7 percent in Canada, less than 10 percent in Japan). Because of their composition, FL can have a significant environmental impact. Thus, in the present study, we used different analytical techniques with the objective of characterizing the raw phosphor material of FL, quantifying the elements mobilized by synthetic landfill leachate and acid rain solutions, and evaluating the environmental impacts related to the disposal of lamps through life cycle analysis (LCA) for the city of Rio de Janeiro scenario. The analysis of the raw material by fluorescence and X-ray diffraction (FRX and DRX) points to a complex composition of solid phases, with a predominance of Ca, P and Al, presence of rare earth elements, As and others. Through microwave-assisted near-total acid extraction, concentrations varying from 1 to 165 g kg-1 were found for Al, Ba, Ce, Eu, La, Mn, P, Sr, and Y in the raw material, and more than 700 mg kg-1 of Hg. Leaching with synthetic solutions was performed with and without agitation, with 0.6 g of sample, 1 mL of solutions, and 3 h of exposure. The test produced the mobilization of several elements with concentrations reaching 23.5 more or less 0.4 mg kg-1 (Hg) in acid rain, and 34.0 more or less 1.0 mg kg-1 (Sr) in landfill leachate. Due to the danger of some elements, the amounts extracted, although low, are worrying, and consecutive leaching, common in a real disposal scenario, can aggravate the situation. The life cycle analysis indicated that the lamps generate greater environmental impacts in the categories of terrestrial ecotoxicity, non-carcinogenic human toxicity, global warming potential and depletion of fossil resources. The analysis indicated that increasing recycling rates can reduce most impacts to the environment by 70 to 90 percent.
23

[pt] DA RESPONSABILIDADE SOCIAL CORPORATIVA À CRIAÇÃO DE VALOR COMPARTILHADO: UMA ANÁLISE DO COLETIVO COCA-COLA BRASIL / [en] FROM CORPORATE SOCIAL RESPONSIBILITY TO CREATING SHARED VALUE: AN ANALYSIS OF COLETIVO COCA-COLA BRASIL

EDUARDO DE ARAUJO PINHEIRO SILVEIRA 13 October 2016 (has links)
[pt] Embora cada vez mais aceita na academia e adotada no meio empresarial, a responsabilidade social corporativa ainda não representa um consenso e está em constante evolução. Evidências indicam que tal abordagem pode proporcionar benefícios às empresas que vão de funcionários mais produtivos e motivados a aumento de vendas e fidelização de clientes, além de ganhos de imagem perante a sociedade. Por outro lado, existem argumentos no sentido de que as empresas devem focar seus esforços tão somente na maximização de lucro, já que a remediação de fraquezas sociais deveria ser uma atribuição exclusiva do governo ou de entidades do terceiro setor. Dessa discussão, emerge a criação de valor compartilhado, um conceito híbrido e que dialoga com as duas vertentes citadas acima a partir do olhar das fraquezas sociais como oportunidades de negócio. A abordagem do valor compartilhado pressupõe, portanto, que as empresas podem – e devem – adaptar seus produtos e serviços, aprimorar sua cadeia de valor e/ou fomentar um ambiente favorável a suas operações a fim de remediar uma determinada causa social e, com isso, obter ganhos comerciais. Para ilustrar a operação dessa estratégia, o presente estudo faz uma análise do Coletivo Coca-Cola Brasil, a plataforma de criação de valor compartilhado da subsidiária brasileira da empresa líder global no setor de bebidas não-alcoólicas. A análise se dá em torno do Coletivo Varejo, que capacita jovens moradores de comunidades carentes de todo o Brasil com vistas à sua incorporação no mercado formal de trabalho e ao aumento de sua autoestima. O resultado do estudo aponta para a existência de impactos positivos tanto para as comunidades apoiadas quanto para a empresa. / [en] Despite being increasingly accepted by academy and adopted by businesses, corporate social responsibility is not yet a consensus, and is still an evolving concept. Evidences show that this approach can generate benefits to enterprises, from more productive and motivated employees to sales growth and client loyalty, besides corporate image gains towards society. On the other hand, some authors argue that companies ought to focus on profit maximization, since social weaknesses mitigation would be a government s or third sector s exclusive attribution. The shared value creation emerges from this discussion as a hybrid concept that dialogs with both points of view and which faces social weaknesses as business opportunities. Therefore, the shared value approach holds that companies must adapt their products and services, redefine productivity in the value chain and/or enable local cluster development in order to mitigate some social cause and obtain commercial gains in consequence. As an illustration of that strategy, the present study analyses Coca-Cola Brasil s Coletivo, the Coca-Cola Company s Brazilian affiliate s shared value platform. The analysis focuses on Coletivo Retail, which trains young residents from poor communities throughout Brazil so that they can reach formal labour market and experience self-esteem growth. Results show positive impacts to both supported communities and Coca-Cola Brasil.
24

[pt] FILMES PARA MUDAR O MUNDO: PRODUÇÃO E DISTRIBUIÇÃO DE DOCUMENTÁRIOS DE IMPACTO SOCIAL / [en] FILMS TO CHANGE THE WORLD: PRODUCTION AND DISTRIBUTION OF SOCIAL IMPACT DOCUMENTARIES

JOANA GUEDES NIN FERREIRA 26 September 2022 (has links)
[pt] Na dissertação Filmes para mudar o mundo - produção e distribuição de documentários de impacto social, investigamos uma nova metodologia de realização de obras do gênero a partir da associação da narrativa documental com um projeto de comunicação estratégica. O documentário de impacto social é construído para ser o centro de um projeto maior, com vistas a propor transformações objetivas na sociedade, ou mesmo ações no intuito de contribuir com mudanças de mentalidade a respeito de problemas específicos. Ativistas, organizações da sociedade civil e simpatizantes engajados atuam em parceria com a equipe do filme, basicamente por meio de práticas crossmídia e advocacy, ampliando seu alcance de público e potencial persuasivo. Da mesma forma, podem dispor do documentário para fomentar debates em seus grupos de origem, num jogo de ganha-ganha. Em termos metodológicos, partimos dos primórdios do documentário social britânico, com seu projeto de educação cívica através do cinema, até a abordagem de iniciativas contemporâneas, dialogando com autores como Brian Winston, Thomas Austin e Jane Chapman, com pesquisas que ajudam a entender as principais questões em torno das condições de existência e do desenvolvimento das formas de produção do cinema documentário. Tratamos também dos problemas da distribuição e da audiência em seu sentido mais amplo, considerando os contextos históricos ditados por questões tecnológicas, de mercado e de comportamentos do público. Veremos ainda como é organizada a campanha de impacto de documentários a partir de dois estudos de caso brasileiros: Menino 23 – infâncias perdidas no Brasil (BRASIL, 2016), e Paratodos (BRASIL, 2016). / [en] In the dissertation Films to change the world – production and distribution of social impact documentaries, we investigate a new methodology of making works of this genre from the association of documentary narrative with a strategic communication project. The social impact documentary is built to be the center of a larger project, aiming to propose objective transformations in society, or even actions in order to contribute to a change of mentality regarding specific problems. Activists, civil society organizations and engaged sympathizers begin to act together with the film team, basically through crossmedia and advocacy practices, expanding its audience reach and persuasive potential. In the same way, they can use the documentary to foster debates in their home groups, in a win-win game. In methodological terms, we start from the beginnings of the British social documentary, with civic education project through cinema, to approach contemporary initiatives, dialoguing with authors such as Brian Winston, Thomas Austin and Jane Chapman, with research that helps to understand the main issues in around the conditions of existence and the development of the forms of production of documentary cinema; We also deal with distribution issues; and the audience in its broadest sense, considering the historical contexts dictated by technological, market and public behavior issues. We will also see how the impact campaign of documentaries is organized from two Brazilian case studies: Boy 23 – The Forgotten Boys of Brazil (BR, 2016), and 4All (BR, 2016).
25

[pt] DESENVOLVIMENTO DE UM DISPOSITIVO GERADOR DE VIBROIMPACTO / [en] DEVELOPMENT OF A VIBROIMPACT DEVICE

ROMULO REIS AGUIAR 29 March 2006 (has links)
[pt] A perfuração de rochas duras ainda é um grande desafio para as empresas de perfuração e exploração de petróleo. Uma das linhas de pesquisas atuais consiste em combinar satisfatoriamente duas técnicas de aumento da taxa de penetração. Esta nova técnica vem sendo chamada de perfuração percussiva-rotativa auto-excitada. Esta dissertação se propõe a desenvolver o primeiro protótipo de um dispositivo que irá operar em ressonância e que será capaz de gerar forças dinâmicas expressivas. De forma resumida, este dispositivo será chamado de RIMD (Resonant Impact Device). Em princípio a idéia é construir um dispositivo em forma de uma caixa preta, na qual será montada na estrutura que vibra, tendo esta caixa dois ajustes, um calibrando a freqüência de ressonância do RIMD e outro agindo sobre os impactos (folga). É conhecido de trabalhos anteriores que o tamanho da folga também possui influência sobre a freqüência natural do sistema. Desta forma, existe uma interdependência entre ambos os ajustes. Um dos primeiros passos no projeto e desenvolvimento do protótipo do RIMD é o dimensionamento do mesmo, de forma que seja pequeno o suficiente para facilitar sua construção e instrumentação no laboratório de vibrações da PUC-Rio, bem como seja representativo do sistema em tamanho real (a ser implantado na coluna de perfuração). Os componentes do RIMD envolvem um sistema massa-mola com baixo amortecimento e algum dispositivo de impacto e de variação da folga. Após a concepção e construção do protótipo, os passos seguintes do estudo são a obtenção das características do RIMD, como a faixa de freqüências o qual atua e a medição das forças impulsivas geradas. Por último, o protótipo também servirá para validar um modelo analítico que permitirá investigações posteriores neste tema, podendo gerar outras possibilidades de construção do RIMD. / [en] Hard rock drilling is still a great challenge for oil companies. One current line of research involves combining the two existing drilling techniques in order to enhance the rate of penetration. This new technique is called Resonance Hammer Drilling. This dissertation proposes the design and development of the first prototype that will operate in resonance, and will be capable of generating considerable dynamic forces. This device will be known as the Resonant Impact Device, or RIMD. In principle the idea is to build some sort of black box, which will be mounted on a vibrating structure with two switches - one calibrating the RIMD resonance frequency and the other acting on the impacts - changing the size of the gap. It is known from previous work that gap size also has influence on the system natural frequency. Therefore there is a relationship between switches. One of the first steps of RIMD design and development is device dimensioning, necessary in order to construct a scale model at the Dynamic and Vibration laboratory at PUC-Rio representative of the real size system. The real size system will be mounted on the drillstring. RIMD components involve a mass-spring system with low damping and some impact and gap variation devices. The analysis of this prototype includes obtaining key characteristics such as the range of possible frequencies and the measurement of the generated impulsive forces. Finally, the built prototype will be used to validate an analytical model that will allow further investigations on this subject providing the way to other possible constructions.
26

[en] METHODOLOGY FOR COMPARING AND SELECTING ENERGY STORAGE TECHNOLOGIES FOR ELECTRIC POWER SYSTEMS: A MULTICRITERIA APPROACH / [pt] METODOLOGIA PARA COMPARAÇÃO E SELEÇÃO DE TECNOLOGIAS DE ARMAZENAMENTO DE ENERGIA PARA SISTEMAS ELÉTRICOS DE POTÊNCIA: UMA ABORDAGEM MULTICRITÉRIO

TARCISIO LUIZ COELHO DE CASTRO 04 November 2024 (has links)
[pt] Nos últimos anos tem havido uma grande modificação da matriz elétrica brasileira, como se pode comprovar ao avaliar os recentes Planos de Expansão de Energia – PDE elaborados pela EPE. Houve um grande investimento em usinas eólicas e fotovoltaicas e uma redução no número de hidroelétricas construídas e planejadas. Além disso, as recentes crises hidrológicas podem sinalizar que a alteração climática, associada a intensificação dos ciclos naturais de bloqueios atmosféricos (ENOS), pode reduzir a geração hidráulica. Com maiores investimentos em usinas eólicas e solares (fontes não controláveis) em larga escala, será necessário dispor de formas para garantir o atendimento à demanda. Essa garantia poderá se dar por meio de mais geração termoelétrica a combustível fóssil, que pode ser reduzida com a implantação de Sistemas de Armazenamento de Energia (SAEs). Assim, a variabilidade de produção de energia das fontes intermitentes precisa ser coberta com recursos que aumentem a flexibilidade operativa. E dessa forma, o interesse maior da pesquisa visou utilizar métodos de análise multicritério de apoio à decisão com base na avaliação do desempenho dos SAEs considerando diversos atributos técnicos, econômicos e socioambientais para selecionar aqueles mais adequados para o suporte de grade na transmissão e distribuição e de gerenciamento de energia elétrica (num sistema hidrotérmico que vai ser cada vez mais complexo de operar com a entrada de grandes plantas de geração renovável intermitente). Foi selecionado o modelo AHP Fuzzy TOPSIS para essa avaliação por facilitar avaliações subjetivas, como aquelas associadas aos aspectos socioambientais e por sua maior transparência numa discussão multidisciplinar e com diversos interlocutores. O resultado mostrou a eficácia da metodologia adotada para a ordenação e seleção das melhores soluções para armazenamento de energia elétrica. / [en] In recent years there has been a major change in the Brazilian electrical matrix, as can be seen when evaluating the last Energy Expansion Plan (PDE 2002) prepared by EPE. There was a large investment in wind and photovoltaic plants, and a reduction in construction and even in the planning of new hydroelectric plants. Associated with this change, it is important to highlight the observation of climate change effects in its hydrographic basins in the last ten years. A long period of drought was noticed, which started in 2012 and lasted until 2019, being an even more serious event than the worst drought ever recorded in Brazilian basins. This fact resulted in the hiring of emergency thermal plants to meet demand in 2022. This hydrological crisis is already a sign that climate change, associated with the intensification of natural cycles of atmospheric blockages (ENSO), can reduce hydraulic generation. And with greater investments in large-scale in the wind and solar plants, it will be necessary to have more thermoelectric generation using fossil fuel to support the intermittence of these renewables, an operation that can be reduced with the implementation of Energy Storage Systems (ESSs). Resources with operational flexibility that can mitigate the increasing variability of the production of renewable sources in electrical matrices will contribute to balancing the load and regulating the frequency. Thus, ESS can reduce the effects of the irregularity of renewable production and help transmission networks to meet demand at peak consumption hours (EPE, 2018), maintain electrical system frequency stability, and optimize the economic performance of generation systems, avoiding activation of less competitive resources such as fossil fuel thermoelectric plants (EPE, 2018). Several countries have already started to invest in pumped storage hydropower (PSH) to enable the intermittent renewable generation and reduce emissions (China and Europe, IDB, 2021).
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[en] DYNAMIC OF A VERTICAL OVERHUNG ROTOR WITH IMPACT / [pt] DINÂMICA DE UM ROTOR VERTICAL EM BALANÇO COM IMPACTO

FREDY JONEL CORAL ALAMO 16 June 2003 (has links)
[pt] Neste trabalho um modelo dinâmico para um rotor vertical em balanço, considerando o fenômeno de contato com a sua guarda, é analisado. A conjunto é modelado como um sistema eixo-rotor-estator com contato. A análise do contato é particularmente complexa pela não linearidade nas equações de movimento. O impacto com o estator é levado em conta através do modelo de contato tipo Kelvin-Vôigt, e, as equações de movimento, do rotor, são deduzidas através da formulação Lagrangeana; estas equações podem capturar os fenômenos devido à vibração lateral, como: precessão direta, precessão retrograda, rolamento e escorregamento. Pela existência de diferentes parâmetros combinados e devido à não linearidade da equação de movimento, a resposta dinâmica não é simples de ser obtida apriori. Portanto, métodos numéricos são empregados para a solução, especificamente emprega-se o método de Runge-Kutta Fehlberg de passo variável. Os resultados da simulação mostram que para certas condições, o rotor pode mudar de orbita devido aos impactos com o estator, podendo chegar a realizar precessão retrograda. Este tipo de fenômeno é considerado como o mais violento e perigoso nas maquinas rotativas. Com o fim de estudar a dinâmica lateral do sistema, um rotor vertical em balanço com guarda anular é investigado. A passagem dela através de sua velocidade critica, quando conduzida por um motor elétrico, é analisada (e também quando o sistema opera em velocidades constantes). Além disso, neste trabalho, os resultados experimentais obtidos da bancada de experimentação são usados para estudar o fenômeno da precessão. / [en] In this work a dynamic model for the overhung rotor, considering the contact phenomenon between the rotor and the stator is analyzed. It is modeled as a shaft-rotor- stator system with contact. The analysis of contact is particularly complex, due to the high nonlinearity of motion equations. Impact with the stator is accounted by a consistent contact model, as Kelvin-Vôigt model, and, rotor`s motion equation is encountered employing Lagrangean`s method; this equations are capable of capturing the phenomenon due to lateral vibration, as: forward whirl, backward whirl, rolling or sliding along the stator. Due to the combined parameters and the effect of nonlinearity in motion equations, the dynamical response is not simple or easily predictable. Numerical simulation is the preferred method of analysis, exactly is used the Runge-Kutta Fehlberg method with variable step. Simulation results show that under certain conditions, a rotor changes its orbit due the impacts with the stator and after that, it executes backward whirl motion. It is a kind of phenomenon, which is considered as the most violent and dangerous in rotating machines. To this end, the analysis of a vertical overhung shaft-disc system with annular guard is investigated. The passing through its critical speed is analyzed when driven by an electric motor (also when the system operates under a constant rotational velocity). In addition, in this work the results obtained with an experimental test rig are used to investigate the whirl phenomenon.
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[en] MODELING OF NEW COMMERCIAL REFRIGERATION SYSTEMS OPERATING WITH LOW-GWP FLUIDS / [pt] MODELAGEM DE NOVOS SISTEMAS DE REFRIGERAÇÃO COMERCIAIS OPERANDO COM FLUIDOS DE BAIXO GWP

RICARDO FERNANDO PAES TIECHER 07 November 2018 (has links)
[pt] Configurações novas e tradicionais de sistemas de refrigeração comerciais foram comparadas considerando sua operação com fluidos refrigerantes alternativos. Primeiramente, desenvolveram-se modelos termodinâmicos para o ciclo transcrítico de dois estágios com refrigerante CO2 (CO2 booster) e para o sistema indireto com CO2 bifásico operando como fluido secundário (pumped CO2). Tais tecnologias foram, em seguida, comparadas com o ciclo de expansão direta (DX) por meio do COP e do consumo anual de energia. Nessa análise, R404A, CO2, e misturas não-azeotrópicas de baixo GWP foram utilizados como fluidos refrigerantes. Em segundo lugar, desenvolveu-se modelo de parâmetros concentrados para simular a operação em regime permanente do sistema de expansão direta com múltiplos compressores e evaporadores. O método multizona foi utilizado na modelagem dos trocadores de calor tubo-e-aleta, com a consideração de diferentes tipos de aletas e superfícies internas para os tubos. Resultados da simulação foram comparados com dados experimentais e, em seguida, calculou-se o impacto ambiental do sistema operando com diferentes refrigerantes de baixo GWP, por meio da metodologia LCCP. / [en] Comparison of new and conventional commercial refrigeration systems, operating with typical and alternative refrigerants, was performed. First, thermodynamic models for the pumped CO2 and the CO2 booster cycles were developed. The COP and the annual energy consumption of these novel designs were compared to those of the traditional direct expansion system in different geographic locations, to take into account year-round climate data. Refrigerant R404A, CO2 and new low-GWP non-azeotropic blends were considered as working uids in this analysis. Second, a component-based lumped parameter model to simulate the steady-state operation of a multicompressor multi-evaporator direct expansion system was developed. The modeling effort considered a multizone approach for the tube-and-fin heat exchangers, as well as addressing enhanced internal surfaces and different fin patterns. Predicted results were compared with experimental data, and a life cycle climate performance (LCCP) analysis was performed to compare the environmental impact of new low-GWP refrigerants.
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[en] POLYAMIDE 12 AND HIGH DENSITY POLYETHYLENE CHARACTERIZATION BEFORE AND AFTER AGING IN WATER AT DIFFERENT TEMPERATURES / [pt] CARACTERIZAÇÃO DA POLIAMIDA 12 E POLIETILENO DE ALTA DENSIDADE ANTES E DEPOIS DO ENVELHECIMENTO EM ÁGUA A DIFERENTES TEMPERATURAS

RODRIGO CAMPELLO TUCUNDUVA 07 February 2018 (has links)
[pt] Nos últimos anos surgiram algumas alternativas para as tubulações de aço carbono que são a grande maioria no transporte de petróleo e gás, com grande destaque para os materiais poliméricos, principalmente por apresentarem baixa densidade em relação aos metais, boa resistência à corrosão e boa processabilidade. Além disso, os polímeros apresentam maior facilidade de manutenção e instalação, tornando-os economicamente viáveis. No entanto, esses materiais podem sofrer degradação quando expostos a produtos químicos e ao calor. O objetivo desse trabalho e avaliar a variação das propriedades mecânicas das poliamidas 12 e dos polietilenos de alta densidade quando envelhecidos em água durante 6 meses a temperatura ambiente e a 70 graus Celsius, tendo em vista que a temperatura de serviço desses materiais varia entre 70 a 80 graus Celsius. Para a caracterização do material foram realizados, ensaio mecânicos de tração, impacto de excitação por impulso sonoro, como a caracterização por microscopia eletrônica. Os resultados das caracterizações das amostras após envelhecimento foram comparados com os resultados obtidos dos materiais originais, de forma a percebermos que todas as amostras sofreram variações em suas propriedades mecânicas. A temperatura ambiente as amostras de PEAD sofreram um aumento em sua rigidez, aumentando sua resiliência, reduzindo sua resistência ao impacto, reduzindo também a tensão de escoamento e reduzindo seu amortecimento. Já para as amostras de PEAD envelhecidas a 70 graus Celsius houve uma redução na sua rigidez e tensão de escoamento, no entanto houve um aumento em sua resistência ao impacto e na resiliência do material. Para as poliamidas 12 envelhecidas a temperatura ambiente houve uma significativa redução na sua rigidez, na sua tensão de escoamento e tensão máxima, houve um aumento na resiliência do material coerente com um aumento da resistência ao impacto e um aumento no amolecimento. A 70 graus Celsius a poliamida 12 mostrou uma redução na sua rigidez, tensão de escoamento e tensão máxima, houve um aumento na resiliência e na resistência ao impacto, seguido de uma redução no amolecimento. Em todas as situações de envelhecimento as PEAD sofreram uma degradação na cor do material, o que não ficou tão visível para as poliamidas 12 principalmente para o envelhecimento a temperatura ambiente. Sendo assim o comportamento mecânico dos polímeros foi influenciado pela temperatura, sempre acarretando variações em suas propriedades mecânicas e dependendo da situação podendo ser mais ou menos relevante. / [en] In recent years, some alternatives have emerged for carbon steel pipelines, which are the majority in the transport of oil and gas, with a great prominence for polymeric materials, mainly due to their low metal density, good corrosion resistance and good processability. In addition, the polymers present greater ease of maintenance and installation, making them economically viable. However, such materials may be degraded when exposed to chemicals and heat. The objective of this work is to evaluate the variation of the mechanical properties of polyamides 12 and high density polyethylenes when aged in water for 6 months at ambient temperature and at 70 degrees Celsius, considering that the service temperature of these materials ranges from 70 to 80 degrees Celsius. For the characterization of the material, mechanical tests of traction, impact and excitation by sonorous impulse were carried out, such as the characterization by electron microscopy. The results of the characterization of the samples after aging were compared with the results obtained from the original materials, in order to realize that all the samples suffered variations in their mechanical properties. At ambient temperature samples of HDPE increased their stiffness, increasing their resilience, reducing their impact resistance, also reducing the yield stress and reducing their damping. However, for HDPE samples aged 70 degrees Celsius, there was a reduction in their stiffness and yield stress, however, there was an increase in their impact strength and material resilience. For polyamides 12 aged at ambient temperature there was a significant reduction in stiffness, flow stress and maximum stress, there was an increase in the resilience of the material consistent with an increase in impact strength and an increase in softening. At 70 degrees Celsius polyamide 12 showed a reduction in stiffness, yield stress and maximum stress, there was an increase in resilience and impact strength, followed by a reduction in softening. In all aging situations the HDPE suffered a degradation in the color of the material, which was not so visible for the polyamides 12 mainly for aging at ambient temperature. Thus, the mechanical behavior of the polymers was influenced by temperature, always leading to variations in their mechanical properties and depending on the situation, being more or less relevant.
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[pt] DO DESCARTÁVEL AO EFÊMERO: A REDUÇÃO DO IMPACTO AMBIENTAL NO DESIGN DE ESPAÇOS DO ACONTECIMENTO / [en] FROM DISPOSABLE TO EPHEMERAL: REDUCING THE ENVIRONMENTAL IMPACT ON HAPPENING S SET DESIGN

SUZANE DE QUEIROZ RIBEIRO 14 April 2020 (has links)
[pt] O objetivo principal da dissertação é o exame da potencialidade criativa do design de espaços de curtos períodos de fruição do público na elaboração e implantação de soluções rumo a redução do seu impacto ambiental. A atividade foco da pesquisa será designada como design de espaços do acontecimento, uma atividade comumente chamada cenografia, mas que transborda os palcos. Intensificada no final do séc. XX, tal atividade se torna cada vez mais potente no ambiente contemporâneo da cidade do Rio de Janeiro. Identifica-se, contudo, um paradoxo no que tange a dinâmica de criação e construção desses espaços e o ciclo de vida dos materiais utilizados. A extensa gama de materiais geralmente especificados nessas construções apresenta inúmeras propriedades favoráveis, como facilidade de manuseio e transporte, resistência estrutural, flexibilidade e leveza, além de diversificadas qualidades estéticas. Por outro lado, tais materiais apresentam também uma durabilidade infinitamente maior do que os curtos períodos de uso aos quais são submetidos. Observa-se necessário evidenciar o eufemismo que mascara a realidade não efêmera, mas essencialmente descartável dessas construções, através da análise de suas durações e de sua cadeia criativa-produtiva. Serão apresentados e analisados casos referência que se constituem como protótipos de soluções para a aproximação da criação e construção dos espaços do acontecimento aos valores inerentes aos ciclos efêmeros biológicos da natureza. Conclui-se que é necessário e possível encontrar novas soluções menos agressivas com o meio ambiente a partir da problematização de cada etapa da cadeia criativa-produtiva da atividade, assim como também que a inserção dos projetos em sistemas pré e ou pós existentes a ele, resultam em possibilidades de caminhos rumo a uma descontinuidade sistêmica da atividade e a redução do seu impacto ambiental. / [en] The main objective of this dissertation is the examination of the creative potentiality at the elaboration and implantation of solutions within set design for public enjoyment through short periods, in towards the reduction of their environmental impact. The focus activity of this research will be designated as happening s set design. This area of activity is commonly called in Brazil scenography, but it doesn t specific apply to spaces out of the stage. Intensified at the end of the 20th century, this activity becomes increasingly powerful in the contemporary environment of the city of Rio de Janeiro. However, there is a paradox regarding the creation and construction dynamics of these spaces and the life cycle of the materials. The extensive range of materials generally specified in these constructions has numerous favorable properties, that includes friendly handling and transportation, structural resistance, flexibility and light weight, in addition to a diversity of aesthetical qualities. On the other hand, such materials also have infinitely longer durability than the short periods of use to which they are subjected. It is necessary to point out the euphemism that masks the nonephemeral but essentially disposable reality of these constructions, through the analysis of their durations and their creative-productive chain. We will present and analyze reference cases that constitute as prototypes of solutions for the approximation of the creation and construction of the spaces of the event to inherent values of nature biological ephemeral cycles. The conclusion is that it is necessary and possible to find new solutions less aggressive to the environment through each stage problematization of the creative-productive chain, as well the insertion of the projects in pre and post existing systems to it, result in possibilities of new paths towards a systemic discontinuity of the happening s set design and the reduction of its environmental impact.

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