Made available in DSpace on 2014-12-17T14:58:25Z (GMT). No. of bitstreams: 1 CarlosAB.pdf: 1249717 bytes, checksum: c205c3ac7994f2c6d8251901cda8facb (MD5) Previous issue date: 2007-01-24 / After the Protocol of Kyoto and of the ECHO 92 - Rio de Janeiro, the attentions of the world focus to the preservation of the environment and of the maintainable use of the natural resources. People were looking for preserving environment for the future generations. Ever since, solutions are looked for the supply of energy in its more acquaintances forms and the substitution of the use of fossil fuels for the such alternative forms as: Photovoltaics, solar heat systems for water, wind , bio-diesel, etc. and in this context the Company of Engineering of the State of Bahia - Cerb changed a diesel pumping system by an wind one, It?s the first community system of this nature in Bahia. Facing problems with the model, a Cerb involved the academic segment of the Federal Center of Technological Education of Bahia Cefetba looking for a solution. This work intends to demonstrate the possibilities of optimization of the pumping communit system that supply water to approximately 50 people in the place of Rom?o, municipal district of S?o Gabriel-Ba. Technical reports were published in AGRENERGD2004-Unicamp SP and Scientific Magazine ETC,Cefetba, 2005. A simulation of the increase of energy is presented for heights of 15 and 20m, considering the eletromecanical balance from the pumping energy to the wind turbine. From the accomplished bibliographical revision, we emphasized the mechanical aspects of the engineering once in UFRN, those studies concentrate on the Department of Mechanical Engineering while, in others eletroelectronic are more emphasized. Finally, documents that we judged important were enclosed for the perfect understanding of this work / A partir do Protocolo de Kyoto e da ECO 92- Rio de Janeiro, as aten??es do mundo est?o voltadas para a preserva??o do meio ambiente e do uso sustent?vel dos recursos naturais, preservando-os para as gera??es futuras. Desde ent?o, buscam-se solu??es para o suprimento de energia nas suas mais conhecidas formas e a substitui??o do uso de combust?veis f?sseis pelas formas alternativas tais como solar fotovoltaica, termo-solar, e?lica, bio-diesel, etc. e neste contexto a Companhia de Engenharia do Estado da Bahia (Cerb) substituiu um sistema de bombeamento com moto-bomba a ?leo diesel por um sistema de bombeamento com energia e?lica, primeiro sistema coletivo desta natureza. Diante dos problemas surgidos, partiu-se para a solu??o envolvendo o segmento acad?mico do Centro Federal de Educa??o Tecnol?gica da Bahia Cefet-BA. Este trabalho pretende demonstrar as possibilidades de otimiza??o do sistema de bombeamento comunit?rio que atende aproximadamente 50 pessoas na localidade de Rom?o, munic?pio de S?o Gabriel-Ba, tendo seus relat?rios t?cnicos publicados no AGRENERGD2004-Unicamp SP e Revista Cient?fica ETC, Cefet-BA, 005. ? apresentada uma simula??o da disponibilidade energ?tica para alturas de 15m e 20m, considerando o balan?o eletromec?nico desde o bombeamento at? o conversor e?lico. Da revis?o bibliogr?fica realizada, optou-se pela ?nfase aos aspectos mec?nicos da engenharia uma vez que na UFRN, esses estudos se concentram no Departamento de Engenharia Mec?nica enquanto que, em outras, os aspectos eletro-eletr?nicos s?o mais enfatizados. Finalmente, foram anexados documentos considerados importantes para a perfeita compreens?o deste trabalho

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-12T13:28:18Z No. of bitstreams: 1 JoseclebioDaFonsecaLucena_DISSERT.pdf: 1438787 bytes, checksum: 0316690714d7086e6bac43c938ec58c9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-14T18:34:15Z (GMT) No. of bitstreams: 1 JoseclebioDaFonsecaLucena_DISSERT.pdf: 1438787 bytes, checksum: 0316690714d7086e6bac43c938ec58c9 (MD5) / Made available in DSpace on 2018-03-14T18:34:15Z (GMT). No. of bitstreams: 1 JoseclebioDaFonsecaLucena_DISSERT.pdf: 1438787 bytes, checksum: 0316690714d7086e6bac43c938ec58c9 (MD5) Previous issue date: 2017-07-31 / A utiliza??o da energia e?lica em larga escala j? evidenciou seus benef?cios com grandes projetos ao redor do mundo. Devido ao baixo n?vel tecnol?gico dos processos produtivos dos componentes de uma torre de produ??o deste tipo de energia, ocorre a gera??o de enormes quantidades de res?duos que podem causar impacto negativo ao meio ambiente. Um dos principais componentes para a concep??o dos geradores e?licos s?o as p?s, que s?o produzidas atrav?s da lamina??o de grandes moldes que cont?m, entre outros componentes, a fibra de vidro na forma de n?otecidos, da qual 10 a 15% de retalhos ? eliminado no momento do corte durante sua fabrica??o. Uma forma de se contornar o problema do descarte dos res?duos provenientes da produ??o das p?s e?licas ? a reutiliza??o destes no desenvolvimento de comp?sitos. Os materiais comp?sitos, impulsionados pela ind?stria aeroespacial e militar, desenvolveram-se de forma bastante significativa nos ?ltimos anos, proliferando em diversas ?reas, devido as suas propriedades ?nicas, tais como: a elevada resist?ncia mec?nica, baixa densidade, excelente resist?ncia t?rmica e ? corros?o dentre outras. A fibra de Juta por apresentar um baixo custo, ser facilmente encontrada na regi?o e apresentar bons resultados de resist?ncia, foi utilizada em densidades diferentes para verificar sua influ?ncia, nas propriedades mec?nicas do comp?sito hibrido. O presente trabalho teve como objetivo desenvolver materiais comp?sitos h?bridos (fibra natural + fibra de vidro) resinados com poli?ster avaliando o comportamento dos comp?sitos refor?ados com res?duos (retalhos) de manta de fibra de vidro oriundos da ind?stria e?lica. Foram realizadas an?lises do percentual de refor?o, resist?ncia ? tra??o e flex?o, absor??o de ?gua e resist?ncia ? intemp?ries para verificar o desempenho dos comp?sitos desenvolvidos. Os resultados obtidos com os materiais comp?sitos refor?ados com tr?s camadas de vidro, quando submetidos a ensaios de tra??o, apresentaram valores 10 vezes superiores ao material sem refor?o. Nos ensaios de flex?o, quando comparados os mesmos as for?as utilizadas foram entre 117 N, para materiais sem refor?o, e 691 N para comp?sitos refor?ados com tr?s camadas de vidro, abrindo novas oportunidades para o desenvolvimento de materiais produzidos com substratos que s?o normalmente descartados para o meio ambiente. / The use of wind energy on a large scale has already shown its benefits with major projects around the world. Due to the low technological level of the productive processes of the wind towers components, the generation of enormous amounts of waste occurs, which can cause negative impact to the environment. One of the main components for the design of wind generators are the blades. They are produced by laminating of large molds that contain, among other components, glass fiber in the form of nonwoven, of which 10% to 15% of flaps are eliminated at the time of cutting during manufacture. One way of avoiding the problem of discarding waste from the production of wind turbines is to reuse them in the development of composites. Composite materials, driven by the aerospace and military industries, have developed quite significantly in recent years, proliferating in several areas due to their unique properties, such as; High mechanical strength, low density, excellent thermal and corrosion resistance among others. The Jute fiber presented a low cost, easily found in the region and presented good resistance results, was used in different densities to verify its influence on the mechanical properties of the hybrid composite. The present work aims to develop hybrid composite materials (natural fiber + glass fiber) with polyester resins , evaluating the influence of the use of fiberglass residues from the wind industry. Density, count yarns, twist tests were used to characterize the reinforcement materials, as well as fiber content, tensile strength, flexural strength, water absorption and weathering analyzes for the performance of the composites developed. The results obtained with the reinforced composites with three layers of glass, when subjected to tensile tests, presented values 10 times higher than the material without reinforcement. In the flexural tests, when compared, the forces used were between 117 N for non-reinforced materials and 691 N for reinforced composites with three layers of glass, opening new opportunities for the development of materials produced with substrates that are normally discarded for the environment.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-13T19:28:10Z No. of bitstreams: 1 PedroBaesseAlvesPereira_DISSERT.pdf: 1699674 bytes, checksum: f6af93574e41ad6736f18ad1e075daae (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-14T18:35:46Z (GMT) No. of bitstreams: 1 PedroBaesseAlvesPereira_DISSERT.pdf: 1699674 bytes, checksum: f6af93574e41ad6736f18ad1e075daae (MD5) / Made available in DSpace on 2017-02-14T18:35:46Z (GMT). No. of bitstreams: 1 PedroBaesseAlvesPereira_DISSERT.pdf: 1699674 bytes, checksum: f6af93574e41ad6736f18ad1e075daae (MD5) Previous issue date: 2016-07-29 / O fornecimento de energia el?trica tem sido considerado um aspecto cr?tico da vida moderna, atuando como papel central no cen?rio econ?mico da maioria dos pa?ses. Com a preocupa??o ambiental, econ?mica e a evolu??o tecnol?gica, a energia e?lica se tornou uma op??o vi?vel de fonte alternativa de energia el?trica. Para a obten??o desse tipo de gera??o el?trica ? necess?ria a constru??o de parques e?licos, que s?o projetos de alta complexidade. Com o intuito de ajudar no processo de edifica??o civil desse tipo de empreendimento, esta pesquisa prop?e um modelo h?brido de planejamento e controle de gerenciamento de projetos para auxiliar a constru??o civil de parques e?licos. A primeira parte da pesquisa foi constitu?da de uma investiga??o de campo preliminar e de estudo da literatura sobre gerenciamento de projetos, energia e?lica e constru??o de parques e?licos. Na segunda etapa, um estudo de caso de constru??o de parque e?lico foi feito, considerado a refer?ncia de constru??o civil para o melhor entendimento do seu processo e de como o gerenciamento de projetos foi usado. Assim, foi proposto um modelo h?brido de planejamento e controle da constru??o civil de parques e?licos que aprimoram a execu??o de projetos, aperfei?oando ?ndices de car?ter financeiro, de satisfa??o do cliente e de compet?ncia em projetos. / The supply of electricity has been considered a critical aspect of the modern life, working as a central role in the economic situation of most countries. The environmental, economic concerns and the technological evolution allowed the consolidation of wind energy as a viable alternative energy source. To produce this type of electricity generation is required the construction of wind farms, which are high complexity projects. This research aims to propose a hybrid management project model of planning and controlling to assist the construction of wind farms by helping the process of building this sort of constructions. The first part of research was a preliminary field investigation and literature study on project management, wind power and construction of wind farms. During the second phase, the case study was performed about the construction of a wind farm, that is considered a reference in civil construction to better understand its process and how the project management was used. With this information, the planning and controlling hybrid model for construction of wind farms was proposed. It aims the improvement of wind projects edification resulting in better financial, customer satisfaction and skill projects aspects.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-22T19:02:49Z No. of bitstreams: 1 MoemaHofstaetter_DISSERT.pdf: 3644332 bytes, checksum: a11bdc18cd973c2f340ed1232b4684d6 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-06T21:12:11Z (GMT) No. of bitstreams: 1 MoemaHofstaetter_DISSERT.pdf: 3644332 bytes, checksum: a11bdc18cd973c2f340ed1232b4684d6 (MD5) / Made available in DSpace on 2017-03-06T21:12:11Z (GMT). No. of bitstreams: 1 MoemaHofstaetter_DISSERT.pdf: 3644332 bytes, checksum: a11bdc18cd973c2f340ed1232b4684d6 (MD5) Previous issue date: 2016-05-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O estado do Rio Grande do Norte (RN) estimulado pelo Governo Federal, atrav?s da sua pol?tica de diversifica??o da matriz energ?tica, investe na implanta??o de parques de energia e?lica, criando novas din?micas econ?micas e de ocupa??o em seus munic?pios. O objetivo desse trabalho ? demonstrar, a partir da observa??o da rela??o entre o discurso de energia limpa e as condi??es de vulnerabilidade com as quais nos deparamos, os impactos socioambientais nas comunidades do entorno dos parques e?licos no estado do Rio Grande do Norte. Do ponto de vista metodol?gico, esse estudo ? qualitativo e interdisciplinar. Contou com um estudo bibliogr?fico e documental e com a coleta de dados a partir de grupos focais e entrevistas. Para a an?lise foi empregada a t?cnica de triangula??o de m?todos. Os resultados e discuss?o (i) colocam em debate a compreens?o da energia e?lica como ?limpa?, ?verde? ou ?amiga do ambiente?; (ii) apresentam a altera??o das realidades social, econ?mica e ambiental locais, com intera??o, mas tamb?m com potencial conflito e tens?o entre os principais atores sociais envolvidos nesta nova din?mica de produ??o energ?tica; (iii) apontam que os parques e?licos n?o s?o totalmente desprovidos de impactos socioambientais e exp?em a popula??o ? vulnerabilidade socioambiental;(iv) afirmam a urg?ncia de se pensar uma gest?o compartilhada, com maior transpar?ncia e participa??o dos grupos afetados, (v)indicam a relev?ncia da efetiva??o de instrumentos de regula??o, financiamento e licenciamento mais comprometidos com crit?rios de justi?a socioambiental. / The state of Rio Grande do Norte (RN) stimulated by the Federal Government, through the diversification of the energy matrix of policy, investing in the deployment of wind power parks, creating new economic and employment dynamics in their municipalities. The aim of this study is to demonstrate, from the observation of the relationship between clean energy speech and vulnerable conditions with which we meet the social and environmental impacts in communities surrounding wind farms in the state of Rio Grande do Norte. From a methodological point of view, this study is qualitative and interdisciplinary. He attended a bibliographical and documentary study and data collection from focus groups and interviews. For the analysis was used triangulation technique methods. The results and discussion (i) put in discussion the understanding of wind power as "clean", "green" or "environmentally friendly"; (Ii) present the changing social realities, economic and environmental sites with interaction, but also with potential conflict and tension between the main actors involved in this new dynamics of energy production; (Iii) point out that wind farms are not entirely without environmental impacts and expose the population to social and environmental vulnerability; (iv) state the urgency of thinking shared management with greater transparency and participation of the affected groups, (v) indicate the importance of effective regulatory instruments, financing and licensing more committed to social and environmental justice criteria.

Made available in DSpace on 2014-12-17T15:38:43Z (GMT). No. of bitstreams: 1 RafaellaLI.pdf: 2919587 bytes, checksum: 351adeebcfb2468e37cefb99bcc196c1 (MD5) Previous issue date: 2008-06-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The purpose of this study was to investigate the social-environmental implications of the first large scale wind farm recently built in Brazil (2006), Parque E?lico de Rio do Fogo (PERF), to the nearby communities. The research was base on the adjustment of the DIS/BCN tool to analyze social impact and it was linked to the multi-method approach. Applying the autophotography strategy, cameras were given to five children from the district of Zumbi, the nearest location to PERF, and they were asked to individually photograph the six places they liked the most and the six places they liked the least in their community. Then, these children were interviewed individually and collectively about the photographs. Adult locals in Zumbi, residents of Zumbi/Rio do Fogo settlement, members of the State and Municipal government and representatives of the PERF were also interviewed with the aid of some of the pictures taken by the children and others that might trigger something to say, as a strategy called sample function. The five children presented positive image towards PERF; all of them chose to photograph it as one of places they liked. Adult population of Zumbi presented positive visual evaluation towards PERF. A small number of the interviewees were aware of the environmental and social benefits of wind energy production. Residents did not participate of the decision making process regarding PERF. They approved the project, especially because of the jobs provided during construction. Nowadays, PERF is something apart from their lives because it no longer provides jobs or any other interaction between the facility and the locals. Residents relate to the land, not with the facility. However, there is no evidence of rejection towards PERF, it is simply seen as something neutral to their lives. The low levels of education, traditional lack of social commitment and citizenship, and the experience accumulated by PERF?s planners and builders in other countries, may be contributing points to the fact that Zumbi residents did not oppose to PERF. It is clear that the country needs a legislation which seriously considers the psycho-social dimension involved in the implementation of wind farms / O prop?sito deste estudo foi investigar as implica??es s?cio-ambientais do recente (2006) primeiro parque e?lico de grande porte do Brasil, Parque E?lico de Rio do Fogo (PERF), sobre as comunidades vizinhas. O trabalho foi baseado em adapta??o da ferramenta DIS/BCN para an?lise de impactos sociais, vinculada a uma abordagem multim?todos. Conforme a estrat?gia da autofotografia, foram entregues c?meras fotogr?ficas para cinco crian?as do distrito de Zumbi, localidade mais pr?xima ao PERF e pedido a elas que, individualmente, fotografassem os seis lugares de que mais gostavam e os seis lugares de que menos gostavam em sua comunidade. Posteriormente, essas crian?as foram entrevistadas individual e coletivamente a respeito das fotografias. Tamb?m foram entrevistados residentes adultos de Zumbi, moradores do Assentamento Zumbi/Rio do Fogo, membros do governo estadual e municipal, e representantes do PERF, com aux?lio de algumas fotografias das crian?as e outras, que provocassem algo a dizer, em uma estrat?gia de investiga??o denominada fun??o de modelo. As cinco crian?as apresentaram imagem positiva do PERF; todas escolheram fotograf?-lo como um dos lugares de que gostavam. A popula??o adulta de Zumbi apresentou avalia??o visual positiva do PERF. Um n?mero reduzido de entrevistados conhecia os benef?cios ambientais e sociais da produ??o de energia e?lica. Os residentes n?o participaram do processo de decis?o a respeito do PERF; eles aprovaram a iniciativa especialmente por conta do fomento de empregos durante a constru??o. Atualmente, o PERF ? algo alheio ?s suas vidas por n?o haver mais ofertas de empregos, nem outra forma de intera??o moradores-empreendimento. Os residentes se relacionam com o terreno e n?o com o empreendimento. No entanto, n?o h? evid?ncias de rejei??o ao PERF, os moradores apenas o v?em como algo neutro ?s suas vidas O baixo n?vel educacional, a falta de vertebra??o social e a atua??o de uma empresa com larga experi?ncia na implanta??o de parques e?licos em outros pa?ses podem ser fatores que contribu?ram para a n?o oposi??o dos moradores de Zumbi ao PERF. Fica clara a falta que faz no pa?s uma legisla??o que considere seriamente a dimens?o psico-social envolvida na implanta??o de parques e?licos

Made available in DSpace on 2014-12-17T14:07:12Z (GMT). No. of bitstreams: 1 MaxdavidOC_DISSERT.pdf: 4786704 bytes, checksum: 3c7952fbe7ed29e1b8d03e70a62dab6c (MD5) Previous issue date: 2013-12-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The research and development of wind turbine blades are essential to keep pace with worldwide growth in the renewable energy sector. Although currently blades are typically produced using glass fiber reinforced composite materials, the tendency for larger size blades, particularly for offshore applications, has increased the interest on carbon fiber reinforced composites because of the potential for increased stiffness and weight reduction. In this study a model of blade designed for large generators (5 MW) was studied on a small scale. A numerical simulation was performed to determine the aerodynamic loading using a Computational Fluid Dynamics (CFD) software. Two blades were then designed and manufactured using epoxy matrix composites: one reinforced with glass fibers and the other with carbon fibers. For the structural calculations, maximum stress failure criterion was adopted. The blades were manufactured by Vacuum Assisted Resin Transfer Molding (VARTM), typical for this type of component. A weight comparison of the two blades was performed and the weight of the carbon fiber blade was approximately 45% of the weight of the fiberglass reinforced blade. Static bending tests were carried out on the blades for various percentages of the design load and deflections measurements were compared with the values obtained from finite element simulations. A good agreement was observed between the measured and calculated deflections. In summary, the results of this study confirm that the low density combined with high mechanical properties of carbon fibers are particularly attractive for the production of large size wind turbine blades / A pesquisa e desenvolvimento de p?s de aerogeradores s?o fundamentais para acompanhar o crescimento no setor de energias renov?veis em todo mundo. Apesar das p?s atualmente serem produzidas tipicamente com materiais comp?sitos refor?ados com fibras de vidro, a tend?ncia de aumento no tamanho das p?s, especialmente no setor offshore, cresce tamb?m o interesse por materiais comp?sitos refor?ados com fibras de carbono, devido ?s suas propriedades, como elevado m?dulo de elasticidade combinado com baixa densidade. Nesse trabalho um modelo de p? desenvolvido para geradores de grande porte (5 MW) foi estudado em escala reduzida. Foram realizados estudos num?ricos empregando t?cnicas de Computational Fluid Dynamics (CFD) para determinar o carregamento aerodin?mico na p?. Foram projetadas e fabricadas duas p?s com materiais comp?sitos de matriz ep?xi, sendo uma p? com refor?o de fibras de vidro e outra com fibras de carbono. Para os c?lculos estruturais, foi adotado o crit?rio de falha por tens?o m?xima. As p?s foram fabricadas pelo processo de Vacuum Assisted Resin Transfer Molding (VARTM), t?pico para este tipo de componente. Uma compara??o do peso das duas p?s foi realizada, e a p? de fibra de carbono apresentou 45% do peso da p? de fibra de vidro. Ensaios est?ticos de flex?o foram realizados nas p?s para v?rios percentuais do carregamento de projeto e as deflex?es medidas foram comparadas com os valores obtidos nas simula??es num?ricas por elementos finitos. Uma boa concord?ncia foi observada entre os valores de deflex?o medidos e calculados. Em resumo, os resultados obtidos neste trabalho confirmam que a baixa densidade combinada com elevadas propriedades mec?nicas das fibras de carbono s?o atrativas para a produ??o de p?s de aerogeradores de grande porte

Made available in DSpace on 2014-12-17T13:53:39Z (GMT). No. of bitstreams: 1 LanaVLCS_DISSERT.pdf: 716391 bytes, checksum: b33e1111ab67ab2b0d5834afe0fe5855 (MD5) Previous issue date: 2014-06-27 / Universidade Federal do Rio Grande do Norte / The consumption of energy on the planet is currently based on fossil fuels. They are responsible for adverse effects on the environment. Renewables propose solutions for this scenario, but must face issues related to the capacity of the power supply. Wind energy offshore emerging as a promising alternative. The speed and stability are greater winds over oceans, but the variability of these may cause inconvenience to the generation of electric power fluctuations. To reduce this, a combination of wind farms geographically distributed was proposed. The greater the distance between them, the lower the correlation between the wind velocity, increasing the likelihood that together achieve more stable power system with less fluctuations in power generation. The efficient use of production capacity of the wind park however, depends on their distribution in marine environments. The objective of this research was to analyze the optimal allocation of wind farms offshore on the east coast of the U.S. by Modern Portfolio Theory. The Modern Portfolio Theory was used so that the process of building portfolios of wind energy offshore contemplate the particularity of intermittency of wind, through calculations of return and risk of the production of wind farms. The research was conducted with 25.934 observations of energy produced by wind farms 11 hypothetical offshore, from the installation of 01 simulated ocean turbine with a capacity of 5 MW. The data show hourly time resolution and covers the period between January 1, 1998 until December 31, 2002. Through the Matlab R software, six were calculated minimum variance portfolios, each for a period of time distinct. Given the inequality of the variability of wind over time, set up four strategies rebalancing to evaluate the performance of the related portfolios, which enabled us to identify the most beneficial to the stability of the wind energy production offshore. The results showed that the production of wind energy for 1998, 1999, 2000 and 2001 should be considered by the portfolio weights calculated for the same periods, respectively. Energy data for 2002 should use the weights derived from the portfolio calculated in the previous time period. Finally, the production of wind energy in the period 1998-2002 should also be weighted by 1/11. It follows therefore that the portfolios found failed to show reduced levels of variability when compared to the individual production of wind farms hypothetical offshore / O consumo de energia no planeta ? atualmente baseado no uso de combust?veis f?sseis. Eles s?o respons?veis por efeitos negativos sobre o meio-ambiente. As energias renov?veis prop?em solu??es para esse cen?rio, mas devem encarar quest?es relacionadas ? capacidade de fornecimento de energia. A energia e?lica offshore desponta como uma alternativa promissora. A velocidade e estabilidade dos ventos s?o maiores sobre oceanos, mas a variabilidade dos mesmos pode provocar flutua??es inconvenientes ? gera??o de energia el?trica. Para diminuir isso, uma combina??o de parques e?licos distribu?dos geograficamente foi proposta. Quanto maior a dist?ncia entre eles, menor a correla??o entre a velocidade dos ventos, aumentando a probabilidade de que produzam conjuntamente um sistema de energia mais est?vel, com menos flutua??es da produ??o de energia. O uso eficiente da capacidade de produ??o dos parques e?licos, entretanto, depende da distribui??o deles em ambientes mar?timos. O objetivo desta pesquisa foi analisar a aloca??o ?tima de parques e?licos offshore na costa leste dos EUA, atrav?s da Moderna Teoria de Carteiras. A Moderna Teoria de Carteiras foi empregada de modo que o processo de constru??o das carteiras de energia e?lica offshore contemplasse a particularidade da intermit?ncia dos ventos, atrav?s dos c?lculos de retorno e risco da produ??o dos parques e?licos. A pesquisa foi desenvolvida com 25.934 observa??es de energia, produzidas por 11 parques e?licos offshore hipot?ticos, a partir da instala??o simulada de 01 turbina oce?nica com capacidade m?xima de 5 MW. Os dados apresentam resolu??o de tempo hor?ria e cobrem o per?odo entre 01 de janeiro de 1998 at? 31 de dezembro de 2002. Por meio do software Matlab R , foram calculadas seis carteiras de m?nima vari?ncia, cada qual para um per?odo de tempo distinto. Diante da desigualdade da variabilidade dos ventos no tempo, estabeleceu-se quatro estrat?gias de rebalanceamento para avaliar o desempenho das carteiras calculadas, o que possibilitou identificar a mais ben?fica ? estabilidade da produ??o de energia e?lica offshore. Os resultados apontaram que a produ??o de energia e?lica dos anos de 1998, 1999, 2000 e 2001 deve ser ponderada pelos pesos das carteiras calculadas nos mesmos per?odos, respectivamente. Os dados de energia de 2002 devem utilizar os pesos oriundos da carteira calculada no per?odo de tempo anterior. Por fim, a produ??o de energia e?lica do per?odo entre 1998-2002 deve ser igualmente ponderada por 1/11. Conclui-se assim que as carteiras encontradas conseguiram demonstrar n?veis de variabilidade reduzidos quando comparados aos da produ??o individual dos parques e?licos offshore hipot?ticos

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-07-04T13:54:59Z No. of bitstreams: 1 JulianaSampaioPedrosoDeHolanda_DISSERT.pdf: 2880107 bytes, checksum: ed485fef9bbe5efe4aa75abfcb8b2f91 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-07-12T15:04:30Z (GMT) No. of bitstreams: 1 JulianaSampaioPedrosoDeHolanda_DISSERT.pdf: 2880107 bytes, checksum: ed485fef9bbe5efe4aa75abfcb8b2f91 (MD5) / Made available in DSpace on 2017-07-12T15:04:30Z (GMT). No. of bitstreams: 1 JulianaSampaioPedrosoDeHolanda_DISSERT.pdf: 2880107 bytes, checksum: ed485fef9bbe5efe4aa75abfcb8b2f91 (MD5) Previous issue date: 2017-03-14 / O presente estudo analisa o modo como o jornal impresso potiguar Tribuna do Norte acompanhou as mudan?as da matriz energ?tica do Rio Grande do Norte, com a implanta??o do primeiro parque e?lico no estado, em janeiro de 2004. Para isso, analisam-se as publica??es sobre o tema entre o per?odo de janeiro de 2003 a janeiro de 2004, utilizando a An?lise Cr?tica do Discurso, sob a ?tica de Norman Fairclough, como instrumento metodol?gico para an?lise de texto e a semi?tica de Roland Barthes para an?lise de imagem. De acordo com os crit?rios jornal?sticos de noticiabilidade e de agendamento, entende-se que o per?odo estudado foi prop?cio para a divulga??o da tem?tica e?lica na m?dia potiguar. O estudo mostra que a quest?o foi subutilizada e que as publica??es priorizaram debates econ?micos ante a pauta ambiental. Avalia-se que as aus?ncias e os silenciamentos midi?ticos n?o foram casuais, mas produtos de interesses pol?ticos e econ?micos. / The present study analyses the way in which the newspaper Tribuna do Norteaccompanied the changes in the energy matrix of Rio Grande do Norte, following the implementation of the first wind farm in the state, in January 2004. For this, the texts published about the theme between January 2003 and January 2004 are analysed, using the Critical Discourse Analysis, according to Norman Fairclough's point of view, as a methodological tool for text analysis and Roland Barthes's semiotics for image analysis. According to the journalistic criteria of noticiability and agenda, it is understood that the period studied was favorable to the dissemination of the wind issue in the media. The study shows that the subject was underutilized and that the publications prioritised economic debates before the environmental agenda. It is evaluated that the absences and the media silences were not casual, but products of political and economic interests.

Made available in DSpace on 2015-03-03T15:40:58Z (GMT). No. of bitstreams: 1 VivianySP_DISSERT.pdf: 549151 bytes, checksum: 1e2dd7da6b78700b33600428b516b5fa (MD5) Previous issue date: 2008-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The human being has a fundamental role in issues concerning scarcity of energy resources as well as in the success of technologies which favor the use of renewable sources, such as wind energy. But what does wind energy mean for people? What are the psychological meanings concerning this term? Aiming to answer these questions, the general objective of this dissertation was to identify and to analyze the knowledge about wind energy taking into account a network of psychological meanings. One hundred and ninety one (191) university students from Natal-RN participated in the study, being male the majority (53%); aged between 17 and 51 years old (M=23.3 years; SD=5.7). Participants responded to self reports using the Natural Semantic Networks (NSW) technique, as well as to several sociodemographic questions. The results showed a consistent, positive and useful general semantic network. In this semantic network, knowledge about wind energy was represented by words that correspond to the appeal of (pro) environmental stance (e.g., clean and nature), that evinced both the technological aspect (e.g., force) and the economic aspect (e.g., economy). Results from different groups were also analyzed. The first set of groups (non-environemental and environmental) was divided considering the course (e.g., ecology and economy). The second set of groups(non-caretaker and caretaker) was divided based on the practice of environmental care expressed. Subtle differences were observed in the semantic networks of caretakers, who emphasized environment, an attribute not mentioned by non-caretakes. This indicates a construction of knowledge that is influenced by the presence or absence of the environmental commitment. Such findings may be useful in the construction of instruments for surveys and in the development of public and educational policies. Additionally, they may assist the media towards a more objective performance concerning wind energy / O ser humano tem um papel fundamental tanto nas quest?es relacionadas ? escassez dos recursos energ?ticos como no sucesso das tecnologias que favorecem o uso de fontes renov?veis, como a energia e?lica. Mas o que as pessoas entendem por energia e?lica? Quais os significados psicol?gicos atribu?dos a este termo? Para responder estas perguntas foi definido como objetivo geral da disserta??o identificar e analisar o conhecimento sobre energia e?lica a partir de uma rede de significados psicol?gicos. Participaram 191 estudantes universit?rios da cidade de Natal-RN, sendo a maioria do sexo masculino (53%), com idades variando de 17 a 51 anos (M = 23,3 anos; DP = 5,7). Esses responderam ? t?cnica de auto-relato conhecida como Redes Sem?nticas Naturais (RSN), al?m de perguntas sociodemogr?ficas. Os resultados analisados a partir de uma an?lise explorat?ria, identificaram uma rede sem?ntica geral consistente, positiva e ?til. Nela, o conhecimento sobre energia e?lica ? representado por palavras que atendem ao apelo (pr?-) ambiental (ex. limpa e natureza), que evidenciam o aspecto tecnol?gico (ex. for?a) e o aspecto econ?mico (ex. economia). Os resultados tamb?m foram analisados a partir de diferentes grupos. O primeiro bloco de grupos (n?o-ambiental e ambiental) foi dividido a partir do curso (ex. ecologia e economia). O segundo bloco de grupos (n?o-cuidadores e cuidadores), foi dividido em fun??o do n?vel de comprometimento ambiental expressado. Foram observadas diferen?as sut?s nas redes sem?nticas dos cuidadores, que, por exemplo, enfatizaram meio ambiente, atributo n?o mencionado pelos n?o-cuidadores. Isso sinaliza uma constru??o do conhecimento influenciada pela presen?a, ou aus?ncia, do comprometimento ambiental. Tais achados poder?o se mostrar ?teis na constru??o de instrumentos para survey, no desenvolvimento de pol?ticas p?blicas e educacionais, al?m de auxiliar uma atua??o mais objetiva da m?dia frente ? energia e?lica

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-08T23:18:13Z No. of bitstreams: 1 AllanRodriguesSilva_TESE.pdf: 23816481 bytes, checksum: d4554a5a05635c895c42dfbae3c3ff21 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-08T23:44:04Z (GMT) No. of bitstreams: 1 AllanRodriguesSilva_TESE.pdf: 23816481 bytes, checksum: d4554a5a05635c895c42dfbae3c3ff21 (MD5) / Made available in DSpace on 2016-06-08T23:44:04Z (GMT). No. of bitstreams: 1 AllanRodriguesSilva_TESE.pdf: 23816481 bytes, checksum: d4554a5a05635c895c42dfbae3c3ff21 (MD5) Previous issue date: 2015-12-21 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A estabiliza??o da oferta de energia no Brasil tem sido um desafio para o planejamento do Sistema Interligado Nacional, diante das varia??es hidrol?gicas e clim?ticas. Termoel?tricas s?o utilizadas como fonte emergencial no per?odo de escassez h?drica. Por?m a utiliza??o de combust?veis f?sseis tem elevado o custo de produ??o, da energia el?trica. Por outro lado, a energia e?lica em alto mar (offshore) vem ganhando import?ncia no cen?rio internacional, e tornando-se competitiva a ponto de tornar-se uma possibilidade futura de gera??o no Brasil. Nesse sentido, o objetivo principal desta tese foi investigar a magnitude e distribui??o dos recursos e?licos offshore, verificando tamb?m possibilidades de complementaridade com a fonte h?drica. Para isto, foi utilizado uma s?rie de dados de precipita??o do Climatic Research Unit (CRU) e conjunto de dados satelit?rios de velocidade de vento do projeto Blended Sea Winds da National Climatic Data Center (NCDC/NOAA). De acordo com crit?rios estat?sticos foi encontrado tr?s tipos de complementaridade presentes no territ?rio brasileiro: h?drica h?drica, e?lica e?lica e h?drica e?lica. Notou-se que houve complemento bastante significativo (r=-0,65) entre as fontes, h?drica e e?lica, principalmente das bacias hidrogr?ficas do sudeste e centro oeste com os ventos do Nordeste. Com intuito de refinar a extrapola??o dos ventos sobre o oceano, foi utilizado m?todo baseado na teoria de Monin-Obukhov para modelar a estabilidade da camada limite atmosf?rica. Foi utilizado o conjunto de dados de fluxos de calor, temperatura e umidade do Projeto Objectively Analized Air-Sea Flux (OAFLUX), al?m de dados de press?o ao n?vel do mar do projeto NCEP/NCAR e o modelo de relevo global ETOPO1 da National Geophysical Data Center (NGDC/NOAA). Verificou-se um bom recurso em ?guas rasas, entre 0-20 metros, estimados em 559 GW. A contribui??o do recurso e?lico em um reservat?rio, foi investigada com um modelo h?brido e?lico-hidr?ulico simplificado que permitiu o c?lculo do n?vel dos reservat?rios a partir de dados de vaz?o afluente, defluente e produ??o de turbina. Notou-se que o sistema h?brido evita os per?odos de estiagem, poupando continuamente ?gua dos reservat?rios atrav?s da produ??o e?lica. Assim, a partir dos resultados obtidos, ? poss?vel afirmar que os bons ventos das costa brasileira podem, al?m de diversificar a matriz el?trica, estabilizar as flutua??es h?dricas evitando racionamentos e apag?es, reduzindo o uso das t?rmicas que eleva o custo de produ??o e emite gases poluentes. Pol?ticas p?blicas voltadas ao incentivo da energia e?lica offshore ser?o necess?rias para seu pleno desenvolvimento. / The stabilization of energy supply in Brazil has been a challenge for the operation of the National Interconnected System in face of hydrological and climatic variations. Thermoelectric plants have been used as an emergency source for periods of water scarcity. The utilization of fossil fuels, however, has elevated the cost of electricity. On the other hand, offshore wind energy has gained importance in the international context and is competitive enough to become a possibility for future generation in Brazil. In this scenario, the main goal of this thesis was to investigate the magnitude and distribution of offshore wind resources, and also verify the possibilities of complementing hydropower. A data series of precipitation from the Climatic Research Unit (CRU) Blended Sea Winds from the National Climatic Data Center (NCDC/NOAA) were used. According to statistical criteria, three types of complementarity were found in the Brazilian territory: hydro ? hydro, wind ? wind and hydro ? wind. It was noted a significant complementarity between wind and hydro resources (r = -0.65), mainly for the hydrographical basins of the southeast and central regions with Northeastern Brazil winds. To refine the extrapolation of winds over the ocean, a method based on the Monin-Obukhov theory was used to model the stability of the atmospheric boundary layer. Objectively Analyzed Air-Sea Flux (OAFLUX) datasets for heat flux, temperature and humidity, and also sea level pressure data from NCEP/NCAR were used. The ETOPO1 from the National Geophysical Data Center (NGDC/NOAA) provided bathymetric data. It was found that shallow waters, between 0-20 meters, have a resource estimated at 559 GW. The contribution of wind resources to hydroelectric reservoir operation was investigated with a simplified hybrid wind-hydraulic model, and reservoir level, inflow, outflow and turbine production data. It was found that the hybrid system avoids drought periods, continuously saving water from reservoirs through wind production. Therefore, from the results obtained, it is possible to state that the good winds from the Brazilian coast can, besides diversifying the electric matrix, stabilize the hydrological fluctuations avoiding rationing and blackouts, reducing the use of thermal power plants, increasing the production cost and emission of greenhouse gases. Public policies targeted to offshore wind energy will be necessary for its full development.