Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-10-18T20:55:14Z No. of bitstreams: 1 WendellRossineMedeirosDeSouza_TESE.pdf: 7150800 bytes, checksum: 939215abfa16589e581080cb1d3e85f5 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-10-24T23:17:21Z (GMT) No. of bitstreams: 1 WendellRossineMedeirosDeSouza_TESE.pdf: 7150800 bytes, checksum: 939215abfa16589e581080cb1d3e85f5 (MD5) / Made available in DSpace on 2017-10-24T23:17:22Z (GMT). No. of bitstreams: 1 WendellRossineMedeirosDeSouza_TESE.pdf: 7150800 bytes, checksum: 939215abfa16589e581080cb1d3e85f5 (MD5) Previous issue date: 2017-05-30 / A exposi??o dos po?os de petr?leo a condi??es extremas os tem levado a in?meros problemas de integridade, mesmo quando projetados adequadamente. O uso de t?cnicas de recupera??o, tal como a inje??o c?clica de vapor, submete os materiais a varia??es de temperatura severas reduzindo a vida ?til do po?o; ainda, podendo levar ? falha do revestimento met?lico e da bainha de cimento. A perda da integridade da bainha de cimento pode acarretar no vazamento dos fluidos presentes na forma??o e, em alguns casos, ocasionando significantes preju?zos ambientais e econ?micos. No caso de po?os sujeitos ? inje??o c?clica de vapor, a resist?ncia, a flexibilidade e as propriedades t?rmicas t?m sido apontadas como chave do problema. Neste trabalho, as an?lises termomec?nicas foram realizadas utilizando o m?todo dos elementos finitos em modo transiente. O revestimento met?lico, a bainha de cimento e a forma??o foram modelados utilizando-se um modelo 2D axissim?trico com elementos quadril?teros de 8 n?s. Foi analisado o comportamento mec?nico de bainha de cimento, sendo tr?s formula??es de pastas estudadas: pasta de refer?ncia e mais duas aditivadas com l?tex em concentra??es de 125 e 250 ml/kg de cimento. A influ?ncia da espessura da bainha de cimento e a taxa de aquecimento foram observadas como tamb?m seis diferentes valores de coeficientes de expans?o t?rmica para pasta de cimento. Foram analisados gradientes de temperaturas distintos de 150 oC, 200 oC, 250 oC, 300 oC e 350 oC, t?picas temperaturas encontradas no processo de inje??o de vapor, bem como em meio a forma??es com v?rios n?veis de rigidez. O estudo evidenciou que um dos problemas da integridade da bainha de cimento devido a inje??o de vapor est? associado a fase de aquecimento do po?o e localizado na regi?o da bainha pr?ximo ? forma??o. Foi constatado que vincular o emprego da formula??o mais flex?vel e expansiva a uma aplica??o do gradiente de temperatura de modo mais lento, pode prevenir o surgimento de danos na bainha de cimento evitando manobras de recimenta??o. Tal procedimento se mostrou eficaz para meios rochosos mais r?gidos bem como para temperaturas alvo mais elevadas. / Exposure of oil wells to extreme conditions has led to numerous integrity issues, even when designed properly. The use of recovery techniques, such as the cyclic steam injection, submits the materials to severe temperature variations, reducing the oil well lifespan; and may lead to failure of the steel casing and cement sheath. The loss of integrity of the cement sheath may lead to leakage of the fluids present in the formation and, in some cases, causing significant environmental and economic damages. In the case of wells subjected to the cyclic steam injection, resistance, flexibility and thermal properties have been identified as the key to the problem. In the present work, thermomechanical analyzes were performed using the finite element method in transient mode. The steel casing, the cement sheath and the formation were modeled using an axisymmetric 2D model with 8-node quadrilateral elements. The mechanical behavior of the cement sheath was analyzed, being three formulations of pastes studied: reference paste and two other paste with latex additives in concentrations of 125 and 250 ml / kg of cement. The influence of the cement sheath thickness and the heating rate were observed as well as six different coefficient values of thermal expansion for cement paste. It was analyzed the temperature gradients of 150 oC, 200 oC, 250 oC, 300 oC and 350 oC, typical temperatures encountered during the steam injection process, as well as between formations with various levels of rigidity. The study revealed that one of the problems of cement sheath integrity due to steam injection is associated with the heating phase of the well and located in the region of the sheath near the formation. It has been found that linking the use of the more flexible and expansive formulation to an extending temperature gradient period application may prevent damage to the cement sheath by avoiding recementing maneuvers. Such a procedure proved to be effective for more rigid rock media as well as for higher target temperatures.

L'objectif de cette etude est la mod elisation, la validation, l'analyse math ematique et la simulation de mod eles de transmission de l'h epatite B en Afrique en g en eral et au S en egal en particulier. Nous proposons de nouveaux mod eles bas es sur les connaissances actuelles de l'histoire naturelle de la transmission du virus de l'h epatite B. Ainsi, nous pr esentons deux mod eles de la transmission du VHB1, un mod ele sans transmission verticale et un autre o u la transmission verticale de la maladie est prise en compte. Ce second mod ele est justi e par la controverse, en ce qui concerne l'incidence des transmissions verticale ou p erinatale au niveau de la zone Afrique ; entre d'une part, l'Organisation Mondiale de la Sant e et d'autre part les sp ecialistes de l'h epatite B au S en egal. Ces mod eles, nous ont conduit a etudier des mod eles epid emiologiques avec une di erentiabilit e, au niveau des susceptibles, et progression de stade pour les infectieux. Nous obtenons une analyse compl ete de la stabilit e de ces mod eles a l'aide des techniques de Lyapunov suivant la valeur du taux de reproduction de base R0. Ce qui nous conduit a l' etude d'un mod ele epid emiologique beaucoup plus g en eral qui englobe ceux propos es pour la mod elisation de la transmission du virus de l'h epatite B. Nous illustrons a la n de ce travail ces mod eles par des simulations num eriques. Ces derni eres sont faites a partir de nos mod eles confront es aux donn ees recueillies du programme de lutte contre l' epid emie de l'h epatite B au S en egal et dans la litt erature. Elles permettrons l' evaluation de l'incidence de la transmission verticale/p erinatale du virus de l'h epatite B sur les politiques de Sant e Publique.

Made available in DSpace on 2015-03-13T17:08:40Z (GMT). No. of bitstreams: 1 ClenubioFS.pdf: 1330843 bytes, checksum: f44365144a87dbadb85a95129360dfdc (MD5) Previous issue date: 2006-10-09 / The northern coast of Rio Grande do Norte State (RN) shows areas of Potiguar basin with high activity in petroleum industry. With the goal of avoiding and reducing the accident risks with oil it is necessary to understand the natural vulnerability, mapping natural resources and monitoring the oil spill. The use of computational tools for environmental monitoring makes possible better analyses and decisions in political management of environmental preservation. This work shows a methodology for monitoring of environment impacts, with purpose of avoiding and preserving the sensible areas in oil contact. That methodology consists in developing and embedding an integrated computational system. Such system is composed by a Spatial Decision Support System (SDSS). The SDSS shows a computational infrastructure composed by Web System of Geo-Environmental and Geographic Information - SWIGG , the System of Environmental Sensibility Maps for Oil Spill AutoMSA , and the Basic System of Environmental Hydrodynamic ( SisBAHIA a System of Modeling and Numerical Simulating SMNS). In a scenario of oil spill occurred coastwise of Rio Grande do Norte State s northern coast, the integration of such systems will give support to decision agents for managing of environmental impacts. Such support is supplied through a system of supporting to spatial decisions / O litoral norte do Estado do Rio Grande do Norte (RN) apresenta ?reas da bacia Potiguar com intensa atividade da ind?stria petrol?fera. Com a finalidade de prevenir e minimizar os riscos de acidentes com ?leo, faz-se necess?rio compreender a vulnerabilidade natural, mapear os recursos naturais e monitorar os derrames de ?leo. O uso de ferramentas computacionais para o monitoramento ambiental, possibilita uma melhor an?lise e tomada de decis?o no planejamento de pol?ticas de conserva??o ambiental. A presente disserta??o apresenta uma metodologia de trabalho para o monitoramento de impactos ambientais, com o prop?sito de avaliar e proteger as regi?es sens?veis ao contato do ?leo. A metodologia consiste em desenvolver e implantar um sistema integrado, constituindo um Sistema de Apoio ? Decis?o Espacial (SADE). O SADE apresenta uma infra-estrutura computacional composta pelo SWIGG (Sistema Web de Informa??es Geogr?ficas e Geoambientais), o AutoMSA (Automatizador de Mapas de Sensibilidade Ambiental para derramamentos de ?leo) e o Sistema BAse de HIdrodin?mica Ambiental (SisBAHIA um Sistema de Modelagem e Simula??o Num?rica - SMSN). Num cen?rio de derramamento de ?leo ocorrido pr?ximo ?s ?reas costeiras do litoral norte do Estado do RN a integra??o destes sistemas disponibilizar? aos agentes respons?veis pelo gerenciamento dos danos ambientais, um sistema de suporte a tomada de decis?o espacial

Made available in DSpace on 2014-12-17T14:58:12Z (GMT). No. of bitstreams: 1 ElsonANM.pdf: 918866 bytes, checksum: 54ffb16de332a5a9c76c3afd577bcea1 (MD5) Previous issue date: 2005-09-16 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The study of aerodynamic loading variations has many engineering applications, including helicopter rotor blades, wind turbines and turbo machinery. This work uses a Vortex Method to make a lagrangian description of the a twodimensional airfoil/ incident wake vortex interaction. The flow is incompressible, newtonian, homogeneus and the Reynolds Number is 5x105 .The airfoil is a NACA 0018 placed a angle of attack of the 0? and 5?simulates with the Painel Method with a constant density vorticity panels and a generation poit is near the painel. The protector layer is created does not permit vortex inside the body. The vortex Lamb convection is realized with the Euler Method (first order) and Adans-Bashforth (second order). The Random Walk Method is used to simulate the diffusion. The circular wake has 366 vortex all over positive or negative vorticity located at different heights with respect to the airfoil chord. The Lift was calculated based in the algorithm created by Ricci (2002). This simulation uses a ready algorithm vatidated with single body does not have a incident wake. The results are compared with a experimental work The comparasion concludes that the experimental results has a good agrement with this papper / Este estudo simula numericamente, atrav?s do M?todo de V?rtices, a intera??o entre uma nuvem de circula??o incidente e um aerof?lio NACA 0018 posicionado com ?ngulos de ataque de 0? e 5?. O n?mero de Reynolds utilizado ? de 5x105 e o escoamento ? considerado incompress?vel. Devido a complexidade do fen?meno de geometria tridimensional, apenas uma se??o do aerof?lio ? simulada transformando o trabalho em bidimensional. Utiliza-se o M?todo dos Pain?is com vorticidades distribu?das para simular o corpo e o ponto de gera??o de vorticidade ? deslocado da superf?cie do painel. Uma camada protetora ? criada para evitar a entrada de v?rtices no corpo. A convec??o dos v?rtices de Lamb presentes ? realizada atrav?s dos esquemas de Euler (1?ordem) e de Adams-Bashforth (2?ordem). A difus?o utiliza o M?todo do Avan?o Rand?mico. As cargas de sustenta??o s?o calculadas atrav?s de um algoritmo desenvolvido por Ricci (2002). A nuvem utilizada tem 366 v?rtices com circula??o de +0.001375692 ou -0.001375692 formando um c?rculo de raio 0,2. A simula??o utilizou um algoritmo existente que foi modificado para o problema em quest?o. Validado atrav?s da simula??o do perfil sem a presen?a da nuvem. Os resultados encontrados mostram uma boa concord?ncia com os encontrados em trabalhos experimentais