Atualmente existem diferentes definições para o conceito de fragilidade ambiental, o que dificulta sua aplicação e a comparação entre os resultados de diferentes métodos. Este trabalho realiza uma revisão bibliográfica sistemática a cerca desse conceito e adota a definição considerada mais adequada. Com base na definição adotada foi proposto e aplicado um método para avaliar a fragilidade ambiental de uma área de estudo. Esse método utiliza pesos para ponderar os diferentes atributos (meio físico, biótico e socioeconômico) envolvidos na análise de fragilidade ambiental, que são definidos com a aplicação do Processo de Análise Hierárquica (AHP). O método proposto também se fundamenta na utilização de um programa de Sistema de Informação Geográfica (SIG) para a estruturação da base de dados, a realização das análises espaciais e a ponderação dos mapas necessários. A área de estudo corresponde a um setor do oleoduto São Paulo – Brasília (OSBRA), com extensão de 18,5 km e largura de 2 km (área total de 83,99 km²) e utilizou-se uma base cartográfica digital na escala 1:10.000. Foram realizadas vistorias de campo para levantar pontos de observação de superfície e para coletar amostras de solo. Realizaram-se ensaios geotécnicos, químicos e mineralógicos com as amostras coletadas. A aplicação do método consistiu na geração de mapas de suscetibilidade intermediários, que combinados geraram o mapa de fragilidade ambiental. Foi importante a utilização do método AHP, pois ele reduz a subjetividade das ponderações qualitativas realizadas. Os resultados obtidos esclarecem a definição do conceito de fragilidade ambiental, além de mostrar a importância da seleção e ponderação dos atributos utilizados no método. O mapa final gerado também permitiu avaliar a sensibilidade do método e seu potencial de aplicação prática. / Currently there are different definitions to the concept of environmental fragility; it complicates its application and makes difficult to compare between different methods. This work addresses the main definitions to this concept and adopts the one considered the most proper. Based in the adopted definition it was proposed a method to evaluate the environmental fragility of a study area. This method applies weights to the different attributes (physical, biotic and socioeconomic) related to the environmental fragility analysis, which are assigned using the Analytic Hierarchy Process (AHP). The method also uses Geographic Information System (GIS) software to structure the database, to conduct the spatial analysis and to assign weights to the maps. The study area is a sector of the São Paulo – Brasília oil pipeline (OSBRA), covering 18.5 km length and 2 km wide (total area of 83,99 km²) and it was used a digital cartographic map at the scale of 1:10,000. Field trips were made to obtain surface observation points and to collect soil samples. Geological and geotechnical tests, mineralogical tests and chemistry analysis were conducted with the soil samples. The method application consists in generating intermediates susceptibility maps, that were combined to generate the environmental fragility map. It was important to use the AHP method, because it reduces the subjectivity of the qualitative weight assignment. The obtained results elucidate the environmental fragility concept and show the importance of the selection and weight assignment of the attributes used in the method. Moreover, the final map provided to evaluate the method sensitivity and its potential of practical application.

A tecnologia dos aços microligados para transporte de gás natural e petróleo tem sido pressionada pelo descobrimento das novas jazidas e o aumento da demanda no mundo. As solicitações ambientais e de resistência mecânica são os parâmetros para o desenvolvimento de aços de alta resistência baixa liga para o transporte de gás e petróleo a menor custo e de forma segura. Neste contexto esta pesquisa investiga, em um aço microligado para tubos API 5L X80, o efeito das transformações de fase obtidas por resfriamentos controlados na fratura induzida por hidrogênio Hydrogen Induced Cracking-(HIC) e nas propriedades mecânicas. Os testes de HIC foram realizados no material como recebido, na espessura da chapa submetida a resfriamentos contínuos e em amostras do material tratadas de forma a simular as regiões de grão grosso da zona afetada pelo calor (GGZAC). Segundo o ciclo de resfriamento, os aços microligados têm microestruturas complexas, como é caso do aço microligado em estudo, onde sua microestrutura, estudada em trabalhos anteriores, é formada principalmente por ferrita, bainita, perlita e microconstituinte austenita/martensita (AM). A morfologia, tamanho, quantidade e distribuição dos produtos de transformação na chapa mudam as propriedades do aço. Esses fenômenos são de grande interesse tecnológico em aços microligados para a fabricação de tubos soldados para o transporte de gás e petróleo, tanto quando a solda é realizada em campo como também durante o encurvamento por indução; aqui as propriedades mecânicas do tubo decorrentes do processo de fabricação termomecânico podem ser degradadas pela ação do aquecimento e dos resfriamentos experimentados na zona afetada pelo calor (ZAC), principalmente na região de GGZAC. A simulação dos ciclos térmicos para o estudo da HIC na espessura da chapa foram realizados em CP austenitizados a 900ºC e submetidos a resfriamentos contínuos no dilatômetro de têmpera. Para simular os ciclos térmicos com resfriamentos controlados focados na GGZAC e a seguir obter CP de tamanho adequado para testes de tração e Charpy, foi necessário fazer os tratamentos térmicos a 1300ºC e resfriamentos contínuos em um simulador termomecânico e dilatômetro Gleeble. O maior tamanho da amostra tratada termicamente neste último equipamento permitiu extrair amostras para avaliar as propriedades mecânicas e a HIC do material, pois as diferentes regiões da ZAC em uma solda real são restritas e não permitem este tipo de ensaios em uma região específica da ZAC. Os resultados permitiram identificar a suscetibilidade de cada microestrutura produto da transformação da austenita na espessura da chapa, sendo a região central da chapa a mais sensível ao hidrogênio no aço como recebido e quando tratado a baixas taxas de resfriamento de 0,5°C/s após austenitizado a 900°C. As bandas grosseiras formadas por estruturas de maior dureza que a matriz na região central diminuíram a resistência à HIC. Da mesma forma nos corpos de prova que simulam a região GGZAC, a fratura induzida pelo hidrogênio foi localizada na região central da espessura embora apresente bainita e ferrita acicular. A falha possivelmente se deve aos elementos remanescentes segregados nesta região central e partição de carbono para os sub contornos de grão da bainita e ferrita que cresceram a partir a austenita primária. As inclusões e precipitados, segundo seu tipo, forma e localização na microestrutura, participam ou não da nucleação e propagação da trinca, sendo a posição mais crítica quando localizadas dentro das estruturas bandeadas. Não foi observada a nucleação de trincas na presença de hidrogênio em precipitados de Nb e Ti. / The technology of microalloyed steels for the transportation of natural gas and oil has been pressed by the discovery of new deposits and the increased demand in the world. Environmental requests for safety and ever increasing mechanical strength are the parameters for the development of high strength low alloy steels for transporting gas and oil at lower cost and safely. In this context, this research investigates, in a microalloyed steel pipe API 5L X80, the effect of phase transformations obtained by controlled cooling on the behavior when loaded with hydrogen - Hydrogen Induced Cracking - (HIC) and in the mechanical properties. HIC tests were performed on as-received material, on samples extracted from the thickness of the plate and subjected to continuous cooling and on samples of the material treated to simulate the coarse-grained regions of heat affected zone (CGHAZ). According to the cooling cycle, the microalloyed steels have complex microstructures: in the steel under evaluation its microstructure, studied in a previous work, consists mainly of ferrite, bainite, pearlite and austenite/martensite constituent (AM). The morphology, size, quantity and distribution of the products of transformation change the properties of plate steel. These phenomena are of great technological interest in microalloyed steels for the fabrication of welded tubes for the transport of gas and oil, when the welding is performed in the field as well as during hot bending; here the mechanical properties of the tube from the process of thermomechanical fabrication can be degraded by the action of heating and cooling experienced in the heat affected zone (HAZ), mainly in the region of CGHAZ. Simulations of thermal cycles for the study of HIC on sheet thickness were performed in coupons subjected to austenitization at 900ºC followed by continuous cooling in the dilatometer. To simulate the thermal cycles with controlled cooling, focused in the CGHAZ, and getting suitable sample sizes for tensile testing and Charpy, it was necessary to austenitize at 1300ºC followed by continuous cooling using the thermal and thermomechanical simulator in a Gleeble dilatometer. Samples heat treated in this equipment were suitable to evaluate the mechanical properties and the HIC of the material for different regions of HAZ, while a real weld would not have enough material to allow this type of testing on a specific region of HAZ. The results showed the susceptibility of each microstructure product of austenite transformation and of the position on the plate thickness. The central region of the plate was more sensitive to hydrogen in the steel as-received and when treated at low cooling rates of 0.5°C/s after austenitization at 900°C. The bands formed by coarse structures of greater hardness than the matrix in the central region decreased the resistance to HIC. Likewise in coupons that simulate the CGHAZ region, the fracture induced by hydrogen was located in the central thickness line, even when the microstructure were bainite and acicular ferrite. Failure there was possibly due to remnants of segregated elements in this central region and carbon partition to the subboundaries of the bainite and ferrite grain that grew from the primary austenite. Inclusions and precipitates, according to their type, shape and location in the microstructure, participating or not in the nucleation and propagation of the crack, were more critical when located within the banded structures; crack nucleation in the presence of hydrogen was not observed at Nb and Ti precipitates.

[pt] Este trabalho apresenta um novo sistema de renderização distribuída destinado ao uso em agrupamentos de PCs. É feita uma extensão à linha de produção gráfica convencional para uma linha de produção gráfica distribuída, que pelo uso de múltiplas linhas de execução permite paralelizar as operações feitas na CPU, na GPU e na rede que interliga os PCs do agrupamento. Este sistema serviu de base para a implementação e o teste de três arquiteturas para renderização distribuída: uma arquitetura com ordenação no início, uma arquitetura com ordenação no fim para renderização volumétrica e uma arquitetura híbrida que tenta combinar as vantagens da ordenação no início e da ordenação no fim. É apresentado um novo algoritmo de balanceamento de carga baseado nos tempos de renderização do quadro anterior. O algoritmo é de implementação muito simples e funciona bem tanto em aplicações com gargalo na geometria quanto em aplicações com gargalo na rasterização. Este trabalho também propõe uma estratégia de distribuição de trabalho entre os computadores de renderização do agrupamento que usa eficientemente os recursos gráficos disponíveis, melhorando assim o desempenho da renderização. Um novo algoritmo de partição paralela do modelo entre os computadores do agrupamento é proposto para a arquitetura híbrida. / [en] This work presents a new distributed rendering system destined for PC clusters. The conventional graphics pipeline is extended to a distributed pipeline that parallelizes the operations done on the CPU, the GPU and the network by using multiple threads. This system was the base for the implementation of three distributed rendering architectures: a sort-first architecture, a sort-last architecture for volume rendering, and a hybrid architecture that seeks to combine the advantages of both sort-first and sortlast architectures. A new load-balancing algorithm based on the rendering times of the previous frame is proposed. The algorithm is very simple to be implemented and works well for both geometry- and rasterization-bound models. A new strategy to assign tiles to rendering nodes is proposed which effectively uses the available graphics resources, thus improving rendering performance. A new parallel model partition algorithm is proposed for the hybrid architecture.

A avaliação de impactos ambientais (AIA) se tornou uma ferramenta amplamente utilizada para análise da viabilidade ambiental de novos empreendimentos e conseqüente subsídio à tomada de decisão nos procedimentos de licenciamento ambiental. Neste sentido, a Secretaria do Meio Ambiente do Estado de São Paulo editou a Resolução SMA nº 42/94, instituindo o relatório ambiental preliminar (RAP) como instrumento de licenciamento ambiental simplificado. Este instrumento foi criado com a intenção de agilizar a tramitação do licenciamento das atividades modificadoras do meio ambiente, incluindo algumas das previstas no artigo 2º da Resolução CONAMA nº 01/86 e, ao mesmo tempo, garantir que os objetivos de prevenção e preservação ambiental sejam assegurados. Como forma de analisar a utilização deste instrumento no licenciamento ambiental de sistemas de distribuição de gás no Estado de São Paulo foram elaboradas três diferentes listas de checagem cujos indicadores buscam, respectivamente, aferir quanto ao atendimento dos requisitos legais, identificar a ocorrência de falhas na elaboração de estudos de avaliação de impacto ambiental e analisar a conformidade de estudos de impacto ambiental com as melhores práticas nacionais e internacionais de AIA. Estes indicadores foram aplicados aos RAPs de sistemas de distribuição de gás elaborados nos anos de 2006 e 2007, num total de dois estudos de caso, o RAP do Sistema de Distribuição de Gás Lins/Marília e o RAP do Sistema de Distribuição de Gás Bauru/Agudos/Pederneiras. Os resultados obtidos demonstram que para ambos os casos analisados: (i) o RAP elaborado não atende adequadamente os requisitos legais definidos pela Secretaria de Meio Ambiente do Estado de São Paulo; (ii) o número de falhas identificadas nos estudos é bastante significativo, com falhas ocorrendo em 83,5% das questões analisadas para o RAP do Gasoduto Lins/Marília e em 89,5% para o RAP do Gasoduto Bauru/Agudos/Pederneiras; (iii) salvo questões pontuais, os estudos de caso analisados estão muito aquém das melhores práticas nacionais e internacionais de AIA, com 76% de resultados insatisfatórios para o RAP do Gasoduto Lins/Marília e 83,5% para o RAP do Gasoduto Bauru/Agudos/Pederneiras. Os resultados obtidos demonstraram que o RAP é um estudo bastante precário para dar subsídio ao licenciamento. É possível identificar uma série de questões de grande relevância para uma adequada tomada de decisão quanto à viabilidade ambiental de empreendimentos que não são exigidas para a efetivação do licenciamento ambiental intermediado por RAP. Desta forma, fica explicita a necessidade de uma revisão do sistema de licenciamento ambiental paulista, como forma de induzir estudos mais bem elaborados e com conteúdo mais abrangente, em consonância com as melhores práticas de AIA adotadas em todo o mundo. / The environmental impact assessment (EIA) become a tool widely used to analysis the environmental suitability of new activities and subsidy the decision making process for the expedition of environmental licensing. In this case, the Secretariat of the Environment from the State of São Paulo edited the resolution number 42/94 instituting the preliminary environmental report (PER), like an simplified instrument of environmental licensing. This instrument was created with the intention of accelerate the transaction of the environmental licensing process for activities with potential to modify the environment, including the foreseen ones in the article 2° of the CONAMA Resolution number 01/86 and, at the same time, to guaranty that the goals of the environmental prevention and preservation are assured. As form to analyze the use of this instrument in the environmental licensing of natural gas pipeline in the State of São Paulo, three different checklists had been elaborated to survey, respectively, the attendance of the legal requirements, to identify the occurrence of the nonconformities in the elaboration of studies of environmental impact assessment and analyze the conformity of environmental impact assessment studies with national and the international best practices in EIA. These elaborated indicators had been applied to the RAPs in the years of 2006 and 2007, in a total of two case studies, the PER of Lins/Marília Gas Line and the PER of Bauru/Agudos/Pederneiras Gas Line. The gotten results demonstrate that for both the analyzed cases: (I) the elaborated PER do not achieve adequately the legal requirements of the Secretariat of Environment of the State of São Paulo; (II) the number of imperfections identified in the studies are very significant, with imperfections occurring in 83,5% of the analyzed questions for the PER of the Lins/Marília Gas Pipeline and in 89,5% for the PER of the Bauru/Agudos/Pederneiras Gas Pipeline; (III) the case studies analyzed are very far from the national and international EIA best practices, with 76% of unsatisfactory results for the PER of Lins/Marília Gas Pipeline and 83.5% for the PER of Bauru/Agudos/Pederneiras Gas Pipeline. The gotten results had demonstrated that the PER is a very precarious instrument of licensing. Is possible to identify series of questions from a great relevance for the decision making process who are not effectively achieved. In such a way, it is explicit the necessity of a revision of the São Paulos environmental licensing system, as a way for more accordance with EIA best practices.

Rapid growth in population along with positive trends in global economy over the past several decades has significantly contributed to an increased demand for various infrastructure needs worldwide. For this reason, the focus of this thesis has been directed towards extending the mechanics of unsaturated soils, which is an emerging geotechnical engineering field to investigate the behavior of two key infrastructure systems, namely pile foundations and energy pipeline systems. The mechanism of soil-pile foundations and soil-pipeline systems interaction behavior has several similarities. Both these infrastructure facilities require comprehensive understanding of the soil-structure interaction mechanism. Reliable estimation of mechanical properties of both the soil and the soil-structure interface is required for the rational interpretation the load-displacement behavior of pile foundations and pipeline systems. Currently, the design of systems is predominantly based on design codes and guidelines that use empirical procedures or employ the principles of saturated soil mechanics. In many scenarios, pile foundations extend either totally or partly in unsaturated soils as the groundwater table level in many regions is at a greater depth. Such scenarios are commonly encountered in semi-arid and arid regions of the world. In addition, pipeline systems are typically buried at shallow depths in unsaturated soil strata, which are susceptible to wetting and drying, freezing and thawing cycles or both, due to seasonal environmental changes. Capillary stress or matric suction in the unsaturated zone increases the effective stress contribution towards the shear strength and stiffness of soil and soil-structure interface. Extending saturated soil mechanics to design or analyze such structures may lead to erroneous estimation of pile foundation carrying capacity or loads transferred on pipeline body from the surrounding unsaturated soil. Experimental, analytical and numerical investigations were undertaken to study the behavior of single pile, pile group, and pipeline systems in saturated and unsaturated sands under static loading. The experimental program includes 40 single model pile and 2×2 pile group, and six prototype pipeline tests under saturated and unsaturated condition. The results of the experimental studies suggest that matric suction has significant contribution towards the mechanical behavior of both pile foundation and pipeline system. The axial load carrying capacity of single pile and pile group increased approximately 2 to 2.5 times and the settlement reduced significantly compared to saturated condition. The influence of matric suction towards a single pile is significantly different in comparison to pile group behavior. The cumulative influence of matric suction and stress overlap of pile group behavior in sandy soils result in erroneous estimation of pile group capacity, if principles of saturated soil mechanics are extended. Group action plays major role in changing the moisture regime under the pile group leading to incompatible stress state condition in comparison to single pile behavior. On the other hand, the peak axial load on the pipe is almost 2.5 folds greater in unsaturated sand that undergoes much less displacement in comparison to saturated condition. Such an increase in the external axial forces may jeopardize the integrity of energy pipeline systems and requires careful reevaluation of existing design models extending the principles of unsaturated soil mechanics. Two analytical design models to estimate the axial force exerted on pipeline body were proposed. The proposed models take account of matric suction effect and soil dilatancy and provide smooth transition from unsaturated to saturated condition. These models were developed since measurement of the unsaturated soil and interface shear strength and stiffness properties need extensive equipment that require services of trained professional, which are expensive and time consuming. The models utilize the saturated soil shear strength parameters and soil-water characteristic curve (SWCC) to predict the mechanical behavior of the structure in saturated and unsaturated cohesionless soils. The prototype pipeline experimental results were used to verify the proposed models. The predicted axial force on pipeline using the proposed models agrees well with the measured behavior under both saturated and unsaturated conditions. Moreover, numerical techniques were proposed to investigate the behavior of pile foundation and pipeline system in saturated and unsaturated sand. The proposed methodology can be used with different commercially available software programs. Two finite element analysis programs were used in this study; namely, PLAXIS 2D (2012) to simulate soil-pile foundation behavior and SIGMA/W (2012) to simulate soil-pipeline system behavior. The proposed techniques require the information of unsaturated shear strength and stiffness, which can be derived from saturated soil properties and the SWCC. The model was verified using pile and pipeline test results from this study and other research studies from the published literature. There is a good agreement between the measured behavior and the predicted behavior for both the saturated and unsaturated conditions. The methodology was further extended to investigate the behavior of rigid and flexible pipelines buried in Indian Head till (IHT) during nearby soil excavation activity. The simulation results suggest that excavation can be extended safely without excessive deformation to several meters without the need for supporting system under unsaturated condition. The studies summarized in the thesis provide evidence that the principles of saturated soil mechanics underestimate the pile foundations carrying capacity as well as the axial force exerted on pipelines in unsaturated soils. Such approaches lead to both uneconomical pile foundation and unsafe pipeline systems designs. For this reason, the pile and pile group carrying capacity and pipeline axial force should be estimated taking into account the influence of matric suction as well as the dilatancy of the compacted sand. The experimental studies, testing techniques along with the analyses of test results and the proposed analytical and numerical models are useful for better understanding the pile foundation and buried pipeline behaviors under both saturated and unsaturated conditions. The proposed analytical and finite element models are promising for applying the mechanics of unsaturated soils into conventional geotechnical engineering practice using simple methods.

A avaliação de impactos ambientais (AIA) se tornou uma ferramenta amplamente utilizada para análise da viabilidade ambiental de novos empreendimentos e conseqüente subsídio à tomada de decisão nos procedimentos de licenciamento ambiental. Neste sentido, a Secretaria do Meio Ambiente do Estado de São Paulo editou a Resolução SMA nº 42/94, instituindo o relatório ambiental preliminar (RAP) como instrumento de licenciamento ambiental simplificado. Este instrumento foi criado com a intenção de agilizar a tramitação do licenciamento das atividades modificadoras do meio ambiente, incluindo algumas das previstas no artigo 2º da Resolução CONAMA nº 01/86 e, ao mesmo tempo, garantir que os objetivos de prevenção e preservação ambiental sejam assegurados. Como forma de analisar a utilização deste instrumento no licenciamento ambiental de sistemas de distribuição de gás no Estado de São Paulo foram elaboradas três diferentes listas de checagem cujos indicadores buscam, respectivamente, aferir quanto ao atendimento dos requisitos legais, identificar a ocorrência de falhas na elaboração de estudos de avaliação de impacto ambiental e analisar a conformidade de estudos de impacto ambiental com as melhores práticas nacionais e internacionais de AIA. Estes indicadores foram aplicados aos RAPs de sistemas de distribuição de gás elaborados nos anos de 2006 e 2007, num total de dois estudos de caso, o RAP do Sistema de Distribuição de Gás Lins/Marília e o RAP do Sistema de Distribuição de Gás Bauru/Agudos/Pederneiras. Os resultados obtidos demonstram que para ambos os casos analisados: (i) o RAP elaborado não atende adequadamente os requisitos legais definidos pela Secretaria de Meio Ambiente do Estado de São Paulo; (ii) o número de falhas identificadas nos estudos é bastante significativo, com falhas ocorrendo em 83,5% das questões analisadas para o RAP do Gasoduto Lins/Marília e em 89,5% para o RAP do Gasoduto Bauru/Agudos/Pederneiras; (iii) salvo questões pontuais, os estudos de caso analisados estão muito aquém das melhores práticas nacionais e internacionais de AIA, com 76% de resultados insatisfatórios para o RAP do Gasoduto Lins/Marília e 83,5% para o RAP do Gasoduto Bauru/Agudos/Pederneiras. Os resultados obtidos demonstraram que o RAP é um estudo bastante precário para dar subsídio ao licenciamento. É possível identificar uma série de questões de grande relevância para uma adequada tomada de decisão quanto à viabilidade ambiental de empreendimentos que não são exigidas para a efetivação do licenciamento ambiental intermediado por RAP. Desta forma, fica explicita a necessidade de uma revisão do sistema de licenciamento ambiental paulista, como forma de induzir estudos mais bem elaborados e com conteúdo mais abrangente, em consonância com as melhores práticas de AIA adotadas em todo o mundo. / The environmental impact assessment (EIA) become a tool widely used to analysis the environmental suitability of new activities and subsidy the decision making process for the expedition of environmental licensing. In this case, the Secretariat of the Environment from the State of São Paulo edited the resolution number 42/94 instituting the preliminary environmental report (PER), like an simplified instrument of environmental licensing. This instrument was created with the intention of accelerate the transaction of the environmental licensing process for activities with potential to modify the environment, including the foreseen ones in the article 2° of the CONAMA Resolution number 01/86 and, at the same time, to guaranty that the goals of the environmental prevention and preservation are assured. As form to analyze the use of this instrument in the environmental licensing of natural gas pipeline in the State of São Paulo, three different checklists had been elaborated to survey, respectively, the attendance of the legal requirements, to identify the occurrence of the nonconformities in the elaboration of studies of environmental impact assessment and analyze the conformity of environmental impact assessment studies with national and the international best practices in EIA. These elaborated indicators had been applied to the RAPs in the years of 2006 and 2007, in a total of two case studies, the PER of Lins/Marília Gas Line and the PER of Bauru/Agudos/Pederneiras Gas Line. The gotten results demonstrate that for both the analyzed cases: (I) the elaborated PER do not achieve adequately the legal requirements of the Secretariat of Environment of the State of São Paulo; (II) the number of imperfections identified in the studies are very significant, with imperfections occurring in 83,5% of the analyzed questions for the PER of the Lins/Marília Gas Pipeline and in 89,5% for the PER of the Bauru/Agudos/Pederneiras Gas Pipeline; (III) the case studies analyzed are very far from the national and international EIA best practices, with 76% of unsatisfactory results for the PER of Lins/Marília Gas Pipeline and 83.5% for the PER of Bauru/Agudos/Pederneiras Gas Pipeline. The gotten results had demonstrated that the PER is a very precarious instrument of licensing. Is possible to identify series of questions from a great relevance for the decision making process who are not effectively achieved. In such a way, it is explicit the necessity of a revision of the São Paulos environmental licensing system, as a way for more accordance with EIA best practices.

[pt] Este trabalho apresenta o desenvolvimento de um sensor inovador combinando três técnicas de inspeção utilizadas nos Pigs Instrumentados Geométrico e Magnético, para a detecção e caracterização de defeitos na geometria em tubulações de aço. O sensor GMD, Geométrico Magnético Discriminador, faz a leitura magnética do duto através da técnica de campo de fuga magnético, com a adição da leitura geométrica além da discriminação de defeitos internos de externos. A combinação dessas três tecnologias habilita a construção de uma ferramenta de inspeção de alta resolução compacta e capaz de identificar e quantificar, com apenas uma coroa de sensores, amassamentos, perdas de espessura e além da sua combinação. Este estudo se apresenta em um momento oportuno, já que a Integração de dados é o ponto fundamental da recente norma de gerenciamento de ricos em dutos, API 1160, na qual combinando os resultados das inspeções de geometria e corrosão, tem-se uma melhor avaliação de risco. Testes foram realizados utilizando um PIG Plano com corpos de prova contendo defeitos variados. Os resultados verificaram que o sensor GMD quantifica e discrimina amassamentos com perda de espessura. Aspectos técnicos do desenvolvimento como os detalhes construtivos do sensor, testes de avaliação a resultados de laboratório são apresentados. / [en] This thesis presents the development of an innovative sensor head for detection and characterization of geometric defects in steel pipes that combines three inspection techniques usually employed separately in Caliper and Magnetic Flux Leakage (MFL) PIGs. The novel Geometric Magnetic Discriminator (GMD) sensor performs high- resolution magnetic pipeline readings using MFL with the addition of internal pipe geometry evaluations and discrimination between internal and external defects. The combination of these technologies in a single sensor facilitates characterization of dents and corrosions, while at the same time optimizing the PIG set-up. According to the repair criteria in the standard API1160, combined defects such as a dent with metal loss, which in the past could only be detected through combined data of two different runs (MFL+ Caliper), must be repaired immediately. The GMD sensor was tested in a linear test rig, known as Flat Pig, and data were taken from different defect sets. Evaluation tests demonstrated that the GMD sensor sizes and discriminates a dent with metal loss. Technical aspects of the development, e.g.: the construction details of the sensor, evaluation tests and laboratory results are presented.

Increasing worldwide demand for petroleum motivates greater efficiency, safety, and environmental responsibility in upstream oil and gas processes. The objective of this research is to improve these areas with advanced control methods. This work develops the integration of optimal control methods including model predictive control, moving horizon estimation, high fidelity simulators, and switched control techniques applied to subsea riser slugging and managed pressure drilling. A subsea riser slugging model predictive controller eliminates persistent offset and decreases settling time by 5% compared to a traditional PID controller. A sensitivity analysis shows the effect of riser base pressure sensor location on controller response. A review of current crude oil pipeline wax deposition prevention, monitoring, and remediation techniques is given. Also, industrially relevant control model parameter estimation techniques are reviewed and heuristics are developed for gain and time constant estimates for single input/single output systems. The analysis indicates that overestimated controller gain and underestimated controller time constant leads to better controller performance under model parameter uncertainty. An online method for giving statistical significance to control model parameter estimates is presented. Additionally, basic and advanced switched model predictive control schemes are presented. Both algorithms use control models of varying fidelity: a high fidelity process model, a reduced order nonlinear model, and a linear empirical model. The basic switched structure introduces a method for bumpless switching between control models in a predetermined switching order. The advanced switched controller builds on the basic controller; however, instead of a predetermined switching sequence, the advanced algorithm uses the linear empirical controller when possible. When controller performance becomes unacceptable, the algorithm implements the low order model to control the process while the high fidelity model generates simulated data which is used to estimate the empirical model parameters. Once this online model identification process is complete, the controller reinstates the empirical model to control the process. This control framework allows the more accurate, yet computationally expensive, predictive capabilities of the high fidelity simulator to be incorporated into the locally accurate linear empirical model while still maintaining convergence guarantees.

The rapidly increasing complexities of hardware designs are forcing design methodologies and tools to move to the Electronic System Level (ESL), a higher abstraction level with better productivity than the state-of-the-art Register Transfer Level (RTL). Behavioral synthesis, which automatically synthesizes ESL behavioral specifications to RTL implementations, plays a central role in this transition. However, since behavioral synthesis is a complex and error-prone translation process, the lack of designers' confidence in its correctness becomes a major barrier to its wide adoption. Therefore, techniques for establishing equivalence between an ESL specification and its synthesized RTL implementation are critical to bring behavioral synthesis into practice. The major research challenge to equivalence checking for behavioral synthesis is the significant semantic gap between ESL and RTL. The semantics of ESL involve untimed, sequential execution; however, the semantics of RTL involve timed, concurrent execution. We propose a sequential equivalence checking (SEC) framework for certifying a behavioral synthesis flow, which exploits information on successive intermediate design representations produced by the synthesis flow to bridge the semantic gap. In particular, the intermediate design representation after scheduling and pipelining transformations permits effective correspondence of internal operations between this design representation and the synthesized RTL implementation, enabling scalable, compositional equivalence checking. Certifications of loop and function pipelining transformations are possible by a combination of theorem proving and SEC through exploiting pipeline generation information from the synthesis flow (e.g., the iteration interval of a generated pipeline). The complexity brought by bubbles in function pipelines is creatively reduced by symbolically encoding all possible bubble insertions in one pipelined design representation. The result of this dissertation is a robust, practical, and scalable framework for certifying RTL designs synthesized from ESL specifications. We have validated the robustness, practicality, and scalability of our approach on industrial-scale ESL designs that result in tens of thousands of lines of RTL implementations.

Due to increasing media focus, there has been growing concern that U.S. students and the school environment are increasingly violent, leading the public to believe that school discipline should become more strict and punitive (Giroux 2003; Schept, Wall, & Brisman 2014). However, scholars argue that there is little evidence that current practices of school discipline have made the school environment safer, but instead have criminalized the school and are disproportionately targeting students of color and disabled students (Beger 2002; Civil Rights Project 2000; Gregory, Skiba, & Noguera 2010; Hirschfield 2008; McNeal & Dunbar 2010; U.S. Government Office of Accountability 2018). The expansion of zero-tolerance policies and the surveillance culture in schools have played a large role in the creation of the school-to-prison pipeline, in which students are increasingly being suspended and expelled from school and coming in contact with the juvenile justice system. This research explores the relation that zero tolerance policies function as the neoliberal social control mechanism to control students who are seen to have “no market value and [are] identified as flawed consumers because of their associations with crime and poverty, redundancy and expendability” (Sellers & Arrigo 2018, p. 66). Zero-tolerance policies function as the latest manifestation of capitalist reconstitution of educational institutions, through curricula, student conduct codes, disciplinary procedures, and the hidden curriculum, constructed of the language of capitalism, disproportionately targeting students of color (Bowles & Gintis 2011). A series of OLS regression analyses were conducted to analyze how community partners and school resource officer involvement impact the rate of suspension, expulsion, and combined school disciplinary measures using the School Survey on Crime and Safety Survey 2005-06 data. It was found that community partners and school resource officers have a positive and negative relationship with disciplinary rates. This research further substantiates that racial and ethnic minority students receive disproportionate rates of discipline.