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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
701

Caracterização mecânica e microestrutural de juntas tubulares soldadas em aço API 5L Grau B com base na norma Petrobrás N-2301 / Mechanical and microstructural characterization of tubular welded joints on API 5L grade B steel based on Brazilian National Standard Petrobras N-2301

Sgobbi, Alexandre Amaral 22 April 2015 (has links)
Para a certificação de um procedimento de soldagem, quer seja de alta responsabilidade na soldagem de oleodutos e gasodutos em tubulações de aço carbono ou para um uso rotineiro e diário em fábricas e oficinas, deve ser realizada uma análise profunda dos fenômenos ocorridos no material de base (MB), no metal de adição (MA) e na zona afetada pelo calor (ZAC). Por meio desta análise criteriosa na qualificação de um procedimento de soldagem, o procedimento é liberado para ser utilizado, seja qual for o objetivo final da soldagem. Apenas com a Especificação do Procedimento de Soldagem (EPS) qualificada em mãos é possível iniciar os trabalhos de soldagem, e caso esta seja seguida integralmente, o sucesso do processo está a um passo de se concretizar. Para demonstração desta interação existente entre qualificação, análise dos resultados, aprovação dos ensaios e aprovação da especificação, foi desenvolvido este trabalho utilizando o material de base na forma tubular API 5L Gr. B soldado com os processos eletrodo revestido (SMAW) e arame tubular autoprotegido (FCAW-S). Foi utilizada uma junta tubular como exemplo de estudo e qualificação de um procedimento de soldagem baseado na documentação contida na norma da Petrobrás N-2301 e em outros códigos e normas, que regem a qualificação do processo de soldagem utilizado em refinarias e plantas de produção brasileiras. Foram estudados em conjunto os resultados obtidos por meio de ensaios mecânicos, ensaios não destrutivos e microestruturais. Ambas as Especificações dos Procedimentos de Soldagem preliminares (pEPS), estabelecidas antes do início da soldagem dos dois processos de soldagem, foram aprovadas e qualificadas, satisfazendo as características macro e microscópicas, metalúrgicas e mecânicas da junta soldada. / A comprehensive analysis of the phenomena occurring in the base metal (MB), filler metal (FM) and the heat affected zone (HAZ) should be conducted to provide the qualification of the welding procedure, either in high-demand carbon steel oil & gas pipelines or standard factory & workshop daily, usual operation. By means of this thorough welding procedure qualification, the process will be released, whatever the ultimate goal of welding. Only after the welding procedure specification (WPS) is qualified, is possible to start any welding work, and being the norm fully observed, the process is nearly to start successfully. The present work has been elaborated to demonstrate the interaction of qualification, result analysis, tests and specification approval, by applying the following elements: tubular base metal API 5L grade B welded with Shielded Metal Arc Welding process (SMAW) and self-shielded Flux Cored Arc Welding process (FCAW-S). A tubular joint was used as sample for a welding procedure qualification studies based on technical documentation specified on Petrobras N-2301, a Brazilian standard, and any others codes and standards that rule welding qualification on refineries & production plants of this company. The results obtained through mechanical testing, non-destructive testing and microstructure were studied together. Both preliminary welding procedure specifications (pWPS) established before the welding of these two welding processes, have been approved and qualified. The support given by welding qualification record (WQR) allows the joints to be welded in production, and result in reliable weld bead that satisfy the macro & microscopic, metallurgical and mechanical characteristics.
702

A eficiência dos investimentos do Programa de Inovação Tecnológica em Pequena Empresa (PIPE): uma integração da análise envoltória de dados e Índice Malmquist / The efficiency of investment for innovation research program small business (PIPE): an integration data envelopment analysis and Malmquist index

Almeida, Mariana Rodrigues de 31 March 2010 (has links)
A avaliação do investimento público pode ser um importante instrumento para nortear a destinação de recursos e, assim, obter melhor desempenho na promoção do desenvolvimento na economia de um país. Nesse sentido, são necessárias técnicas adequadas para avaliar o desempenho das empresas, sobretudo das pequenas empresas. Com base em novos procedimentos de avaliação, a presente pesquisa tem como objetivo geral analisar a eficiência dos investimentos públicos direcionados pelo Programa de Inovação Tecnológica em Pequenas Empresas (PIPE), do programa da Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). A pesquisa foi desenvolvida no Estado de São Paulo, nas empresas financiadas pela FAPESP e conduzida, inicialmente, por meio de uma survey com o propósito de coletar dados necessários para alimentar as técnicas Análise Envoltória de Dados (DEA) e Índice de Malmquist. Para atingir o objetivo proposto, formulou-se um modelo conceitual composto por oito hipóteses. A pesquisa de campo contemplou uma amostra de 148 projetos vinculados a 113 pequenas empresas. Os resultados foram apresentados em cinco etapas: etapa I - a evolução dos recursos financeiros destinado ao programa PIPE durante o período de 1997-2008; etapa II - análise qualitativa dos projetos nos parâmetros sobre tipo, tipologia, modelo inovativo, estratégia e localização; etapa III - análise univariada e bivariada das variáveis; etapa IV - análise de eficiência dos projetos e empresas sob a perspectiva das áreas de conhecimento e setores econômico; etapa V - a integração do DEA-Malmquist para as empresas fomentadas na fase III do programa PIPE. Utilizou-se dois teses estatísticos para validar as hipóteses: o teste de Mann-Whitney e o teste do Qui-Quadrado. Os resultados possibilitam identificar, para o órgão fomentador, melhorias no processo de análise dos projetos e, ainda, para novos empresários, recomendações com base nos projetos de eficiência máxima. / Evaluation of public investment can be an important tool to guide correctly the allocation of resources and thus achieve better performance in promoting development in the economy of a country. Accordingly, appropriate techniques are needed to evaluate the performance of businesses, particularly small businesses. Based on recent evaluation techniques, this research aims at analyzing the efficiency of public investment targeted by the Programa de Inovação Tecnológica em Pequenas Empresas (PIPE), a program of the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). The study was conducted in FAPESP financed companies of São Paulo and led initially by means of a survey in order to collect the data needed to feed the Data Envelopment Analysis (DEA) and Malmquist Index. To achieve this purpose, formulated a conceptual model composed with eight research hypotheses. The field research was performed with a sample of 148 projects linked to 113 small businesses. The results were presented in five stages: Stage I - the evolution of financial resources for the PIPE program during the period 1997-2008, stage II - qualitative analysis of project parameters on type, typology, innovation models, strategy and location; stage III - univariate and bivariate analysis of variables; stage IV - efficiency analysis of projects and companies from the perspective of knowledge areas and economic sectors; stage V - the integration of the DEA-Malmquist encouraged companies to phase III of the PIPE program. Used two test to validate the statistical assumptions: the Mann-Whitney and Chi-Square test. The results enable us to identify, for the national developers, improvements to the analysis of projects and also for new entrepreneurs, recommendations based on projects for maximum efficiency.
703

Estudo experimental e modelagem matemática de ondas no escoamento estratificado óleo-água em tubulação levemente inclinada / Experimental study and mathematical modeling of waves in slightly-inclined oil-water stratified pipe flow

Mello, Diego Oliveira de 08 October 2007 (has links)
Embora o escoamento estratificado óleo-água seja comum na indústria do petróleo, existem poucos trabalhos na literatura sobre a estrutura ondulatória encontrada no escoamento em dutos ascendentes ou descendentes. O objetivo deste trabalho é entender e caracterizar as estruturas interfaciais ondulatórias em escoamentos estratificados óleo e água em dutos levemente inclinados e comparar com os resultados retirados da modelagem proposta. Uma primeira tentativa de modelar a onda interfacial óleo-água através da equação da energia bifásica unidimensional para regime permanente é apresentada e comparada aos resultados obtidos experimentalmente. Valores de comprimento de onda foram coletados para quatro ângulos de inclinação a partir da horizontal (-5º, -2º, 2º e 5º) e diversos pares de vazão de óleo e água. Os dados foram extraídos de frames de vídeos de alta resolução através de uma técnica manual. Um software baseado em LabView foi desenvolvido para possibilitar a automação da obtenção do comprimento de onda e amplitude. Os comprimentos de onda obtidos com a técnica automática foram comparados com os dados obtidos através da técnica manual. O mensuramento é bem satisfatório e sugere que a ferramenta experimental proposta possa ser aplicada para o estudo de qualquer padrão de escoamento óleo-água, onde uma estrutura ondulatória possa ser identificada. A validade da modelagem da onda interfacial proposta foi avaliada através da comparação entre os resultados teóricos e dados experimentais. A concordância observada é encorajadora. / Even though the oil-water stratified flow pattern has a common occurrence in the upstream oil industry, quite often in directional wells, there are only a few works in the literature dealing with its interfacial wavy structure. This work has the mean goal of comprehending a characterizing the interfacial wave structure in inclined water-oil stratified pipe flow, comparing it with the proposed model. A model, based on the steady-state one-dimensional two-phase flow energy equation is presented and compared to our experimental data. Wave lengths and amplitude data were collected at four inclinations from the horizontal (-5º, -2º, 2º and 5º) and several oil and water flow rates. The data were extracted form high-resolution video images through a manual technique. A LabView based software was developed in order to obtain the lengths and amplitude automatically. Wave length obtained from it were compared to the manual technique data. The satisfactory measurement suggests the applicability of the experimental tool to any water-oil pipe flow pattern, where a wave structure can be identified. The validity by the comparison between theoretical and experimental data. The agreement observed is promising.
704

Resistência à fadiga de tubo API 5L X65 cladeado e soldado circunferencialmente com eletrodos de Inconel® 625 / Fatigue strength of API 5L X65 cladded pipe girth welded with Inconel® 625 electrodes

Santos, Elielson Alves dos 06 April 2016 (has links)
As recentes descobertas de petróleo e gás na camada do Pré-sal representam um enorme potencial exploratório no Brasil, entretanto, os desafios tecnológicos para a exploração desses recursos minerais são imensos e, consequentemente, têm motivado o desenvolvimento de estudos voltados a métodos e materiais eficientes para suas produções. Os tubos condutores de petróleo e gás são denominados de elevadores catenários ou do inglês \"risers\", e são elementos que necessariamente são soldados e possuem fundamental importância nessa cadeia produtiva, pois transportam petróleo e gás natural do fundo do mar à plataforma, estando sujeitos a carregamentos dinâmicos (fadiga) durante sua operação. Adicionalmente, um dos problemas centrais à produção de óleo e gás das reservas do Pré-Sal está diretamente associado a meios altamente corrosivos, tais como H2S e CO2. Uma forma mais barata de proteção dos tubos é a aplicação de uma camada de um material metálico resistente à corrosão na parte interna desses tubos (clad). Assim, a união entre esses tubos para formação dos \"risers\" deve ser realizada pelo emprego de soldas circunferenciais de ligas igualmente resistentes à corrosão. Nesse contexto, como os elementos soldados são considerados possuir defeitos do tipo trinca, para a garantia de sua integridade estrutural quando submetidos a carregamentos cíclicos, é necessário o conhecimento das taxas de propagação de trinca por fadiga da solda circunferencial. Assim, neste trabalho, foram realizados ensaios de propagação de trinca por fadiga na região da solda circunferencial de Inconel® 625 realizada em tubo de aço API 5L X65 cladeado, utilizando corpos de prova do tipo SEN(B) (Single Edge Notch Bending) com relações entre espessura e largura (B/W) iguais a 0,5, 1 e 2. O propósito central deste trabalho foi de obter a curva da taxa de propagação de trinca por fadiga (da/dN) versus a variação do fator de intensidade de tensão (ΔK) para o metal de solda por meio de ensaios normatizados, utilizando diferentes técnicas de acompanhamento e medição da trinca. A monitoração de crescimento da trinca foi feita por três técnicas: variação da flexibilidade elástica (VFE), queda de potencial elétrico (QPE) e análise de imagem (Ai). Os resultados mostraram que as diferentes relações B/W utilizadas no estudo não alteraram significantemente as taxas de propagação de trinca por fadiga, respeitado que a propagação aconteceu em condições de escoamento em pequena escala na frente da trinca. Os resultados de propagação de trinca por fadiga permitiram a obtenção das regiões I e II da curva da/dN versus ΔK para o metal de solda. O valor de ΔKlim obtido para o mesmo foi em torno de 11,8 MPa.m1/2 e os valores encontrados das constantes experimentais C e m da equação de Paris-Erdogan foram respectivamente iguais a 1,55 x10-10 [(mm/ciclo)/(MPa.m1/2)m] e 4,15. A propagação de trinca no metal de solda deu-se por deformação plástica, com a formação de estrias de fadiga. / Recent oil and gas discoveries in the Pre-Salt layer represent a huge exploration potential in Brazil, however, the technological challenges for the exploitation of these mineral resources are immense and therefore have motivated the development of studies looking for efficient methods and materials for their productions. The oil and gas pipellines, called risers, are elements that are necessarily welded and have fundamental importance in the production chain, since they transport oil and natural gas from the sea bed to the platforms and are subject to dynamic loads (fatigue) during operation. Additionally, one of the central problems in the production of oil and gas in the Pre-Salt reserves is directly associated with a highly corrosive media, such as H2S and CO2. A cheaper way to protect the pipelines from these medias is applying a protective layer of a corrosion resistant metal on the inner diameter of these pipes, creating a cladded pipe. Thus, a joining process of these pipes to form the risers must be carried out by the use of girth welds with a corrosion resistance material similar to the clad metal. As the welded structures are seen as potential location of \"crack like\" defects, to ensure the structural integrity of such component when subjected to repetitive loading conditions, it is necessary to know the fatigue crack growth rates for the girth weld. Therefore, in this work it was carried out fatigue crack propagation tests in the weld region of an API 5L X65 cladded pipe with Inconel® 625, girth welded using Inconel® 625 electrodes. From the welded region, Single Edge Notch Bending specimens, SEN(B), were removed with different thickness and width ratios (B/W= 0.5, 1, and 2). From the fatigue tests, the crack propagation rates (da/dN) as function of the variation of the stress intensity factor (ΔK), were determined for the weld metal, using different crack size measurement techniques: the elastic compliance (EC), electric potential drop (EPD) and image analysis (IA). The results showed that the different B/W ratios used in study did not modified significantly the fatigue crack growth rates, considering that crack propagation took place under small scale yielding conditions. The results of fatigue crack growth tests allowed to obtain the regions I and II of da/dN x ΔK curves for the weld metal. The ΔKth value obtained for the weld metal was around 11,8 MPa.m1/2 and the found values of the experimental constants C and m of Paris-Erdogan\'s equation were respectively equal to 1,55 x10-10 [(mm/cycle)/( MPa.m1/2)m] and 4.15. The micromechanism of fatigue crack growth took place by plastic deformation, with the formation of fatigue striations.
705

Proyecto de robot de inspección de cañería submarina

Fernandez da Costa, Alejandro Marcelo January 2017 (has links)
Offshore oil production presents major challenges due to extreme environmental conditions. With present state of the art robotics, precision mechanics and automation it is now possible to provide solutions to those working conditions. The present work is part of a solution to the problem of the unblocking a subsea oil pipeline of small diameter and extensive length by designing and manufacturing a robot capable of moving inside the pipeline. Based on the previous study of an interdisciplinary group, the implementation of an umbilical cable was defined with the purpose of assuring the supply of electrical power for the robot’s energy requirements, control signals and a mechanical link to avoid the possibility of getting stuck. Similarly, the robot's movement strategy was defined based on a high reliability mechanism, capable of overcoming the great tension resulting from the interaction of the long umbilical cable with the inside of the pipe. In this work, the mechanical design is performed to implement a robot capable of overcoming big cable tensions with small components, integrating commercial components and others custom made. A solution was implemented to convert the electric power received through the cable to the mechanical power in the form required by the displacement mechanism. For this, a detailed engineering design is presented that integrates a high performance electric motor, a two-stage planetary gear transmission for high reduction ratio, a power split transmission driven by disc clutches and a mechanical power distribution stage required by the mechanism responsible for the displacement. / La producción de petróleo offshore presenta grandes desafíos por las condiciones en que se lleva a cabo, actualmente es posible darle solución con la ayuda de la robótica, la mecánica de precisión y la automatización. El presente trabajo es parte de una solución al problema de la desobstrucción en una tubería de petróleo submarina de pequeño diámetro y largo tendido mediante el diseño y la construcción de un robot capaz de trasladarse por el interior de la misma. En base al estudio previo de un grupo interdisciplinario se definió la implementación de un cable umbilical con el propósito de asegurar el suministro de potencia eléctrica para los requerimientos de energía de robot, el enlace de señales destinadas al control y un vínculo mecánico para proveer seguridad ante un eventual desperfecto. Similarmente se definió la estrategia de movimiento del robot en base a un mecanismo de alta confiabilidad, capaz de vencer una gran tensión producto de la interacción del largo cable umbilical con el interior de la tubería. En este trabajo se realiza el diseño mecánico para implementar un robot capaz de realizar grandes esfuerzos con componentes de tamaño reducido, integrando componentes comerciales y otros hechos a medida. Para ello, se implementó una solución para convertir la potencia eléctrica recibida a través del cable a la potencia mecánica en la forma requerida por el mecanismo que da lugar al movimiento. Para dicha solución se presenta un diseño detallado que integra un motor eléctrico de alto desempeño, una transmisión planetaria reductora de dos etapas, una transmisión inversora accionada por embragues de discos y una etapa de distribución de potencia mecánica requerida por el mecanismo responsable del movimiento.
706

Efeito da deformação mecânica a frio no processo corrosivo do aço API 5L X65 em água do mar sintética /

Lima, Alexandre Pereira de January 2019 (has links)
Orientador: Eduardo Norberto Codaro / Resumo: Este trabalho teve como objetivo de realizar a investigar da influência da deformação plástica a frio no processo corrosivo de tubulação de oleoduto em contato com agua do mar. As tubulações de transporte de petróleo são submetidas a ambientes altamente corrosivos no fundo do mar, sendo que concomitantemente estas sofrem deformações plásticas durante sua utilização, fato este que altera suas propriedades mecânicas, o que faz que tal fenômeno seja passível de um estudo mais detalhado a respeito. Para realizar este estudo se retirou amostras de um tubo constituído pelo aço X65 e de acordo com a norma API 5L, fabricado para a indústria petrolífera para ser usado no transporte do óleo, tais amostras foram submetidas a um processo de deformação a frio até atingir a região plástica nos percentuais de 0,5%; 1,0%; 1,5%; 2,0% e 2,5%, acima do limite de escoamento em um equipamento para ensaio de tração. Para avaliar o processo corrosivo foi realizado ensaios eletroquímicos laboratoriais com o intuito de caracterizar qualitativamente e quantitativamente o processo corrosivo deste aço em solução de agua do mar sintética normatizada além de estudar a influência do oxigênio no processo de corrosão neste aço. Foi utilizado as técnicas eletroquímicas de Potencial em circuito aberto, polarização por Tafel e Espectroscopia de impedância eletroquímica, verificando que a deformação plástica não apresentou variação significativa proveniente da deformação plástica, além do aumento continuo da cor... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this work was to investigate the influence of cold plastic deformation on the corrosive process of pipeline pipeline in contact with sea water. The petroleum transport pipelines are subjected to highly corrosive environments in the seabed, and at the same time they undergo plastic deformations during their use, fact that changes their mechanical properties, which makes this phenomenon demands for a more detailed study about that. In order to carry out this study, samples were taken from a tube made of X65 steel and according to API 5L, manufactured for the petroleum industry to be used for transporting the oil, these samples were subjected to a cold deformation process until reaching the plastic regions in the percentages of 0.5%; 1.0%; 1.5%; 2.0% and 2.5%, above the flow limit in a tensile test equipment. In order to evaluate the corrosive process, it was carried out laboratory electrochemical tests with the purpose of characterizing qualitatively and quantitatively the corrosive process of this steel in standardized synthetic water, in addition to studying the influence of oxygen in the corrosion process in this steel. It was used the electrochemical techniques of Potential in open circuit, polarization by Tafel and Electrochemical impedance spectroscopy, verifying that the plastic deformation did not present significant variation from the plastic deformation, besides the continuous increase of the current during the anodic sweep evidences the absence of pa... (Complete abstract click electronic access below) / Mestre
707

Dynamique des effluents et des contaminants associés au système d’assainissement de la Communauté d’Agglomération de Pau Pyrénées (CDAPP). / Wastewater and contaminants dynamic in CDAPP (Pau urban community) sewer system

Bersinger, Thomas 10 December 2013 (has links)
L’optimisation du système d’assainissement et la réduction des rejets d’eaux résiduaires urbaines non traitées est devenue un enjeu majeur pour de nombreuses collectivités dans le but d’atteindre les objectifs de qualité des milieux aquatiques fixés par la Directive Cadre européenne sur l’Eau (DCE 2000/60/CE). Pour cela, une parfaite connaissance du système d’assainissement est nécessaire. L’objectif de cette thèse, financée par la CDAPP et l’Agence de l’Eau Adour Garonne, était l’étude de la dynamique du système d’assainissement de la CDAPP et de sa contribution sur les flux de polluants dans le milieu récepteur (le Gave de Pau). La première étape du travail a été consacrée à la caractérisation hydraulique et physicochimique du système d’assainissement par temps sec et par temps de pluie. Une étude hydraulique a été tout d’abord réalisée et a permis de mieux appréhender la dynamique des déversements via les déversoirs d’orage (DO) en fonction de la nature des évènements pluvieux. D’autre part, la caractérisation physico chimique des eaux usées (matières en suspension ou MES, demande chimique en oxygène ou DCO, métaux, hydrocarbures aromatiques polycycliques) a mis en évidence que pour l’ensemble de ces paramètres, une nette augmentation des flux par temps de pluie était observée en particulier en début d’événement (augmentation d’un facteur de 2 à 10). Ce phénomène s’explique par l’apport de polluant par les eaux de ruissellement et l’érosion des dépôts accumulés par temps sec dans les réseaux. Seul l’azote total se comporte différemment puisqu’il est majoritairement présent sous forme dissoute. Afin de mieux appréhender la dynamique des paramètres polluants réglementaires (MES, DCO et azote), un suivi haute fréquence (au pas de temps de cinq minutes) a été mis en place durant un an à l’aide de sondes de turbidité et de conductivité. Ce suivi en continu constitue la troisième partie de ce travail. Des corrélations (r² ≈ 0,9) ont été établies entre d’une part, les paramètres polluants DCO et MES, et la turbidité et d’autre part, entre la conductivité et l’azote total. Ces enregistrements ont permis une meilleure compréhension du fonctionnement du système d’assainissement : mise en évidence du phénomène de first flush, estimation des flux polluants déversés via les DO, étude des phénomènes de stockage dans les réseaux. La dernière partie de cette thèse vise à l’étude de la contribution des rejets d’assainissement dans le milieu récepteur. Elle a permis de démontrer la contribution modérée du rejet de sortie de STEP (entre 1 et 15 %) par temps sec. Par temps de pluie, la contribution du système d’assainissement via les DO est extrêmement variable suivant les conditions hydro-climatiques (de < 1 % à plus de 50 %). Ce travail a permis d’une part d’apporter des résultats utilisables par le gestionnaire de l’assainissement pour optimiser la gestion des eaux usées de la CDAPP. D’autre part, ce travail apporte des résultats plus fondamentaux relatifs à une meilleure connaissance de la dynamique hydrologique et physicochimique des eaux résiduaires urbaines et des polluants associés tels que la mise en évidence, à l’aide d’outils statistiques, des paramètres influençant les déversements et les concentrations en polluants par temps de pluie. / Optimization of sewer system and reduction of untreated wastewater discharges has become a key issue for many communities in order to achieve the good quality of aquatic environments set by the European Framework Directive (WFD 2000/60/EC). For this, a perfect knowledge of sanitation is required. The objective of this thesis, funded by CDAPP and Adour Garonne Water Agency, was the study of the dynamics of the CDAPP sanitation and its contribution to the pollutants fluxes in the receiving environment (the river Gave de Pau). The first step of the work was devoted to the hydraulic and physicochemical wastewater characterization during dry and wet weather. A hydraulic study was first carried and helped to better understand the dynamics of discharges through the combined sewer overflow (CSO) according to the rainfall events characteristics. On the other hand, the physico-chemical characterization of wastewater (suspended solids or TSS, chemical oxygen demand or COD, metals, polycyclic aromatic hydrocarbons) showed that for all these parameters, a clear increase of pollutant fluxes was observed at the beginning of the rainfall event (increase by a factor of 2 to 10). This phenomenon is explained by the runoff contribution and erosion of sediments accumulated in the networks during dry weather periods. Only total nitrogen behaves differently because it’s mostly dissolved. To better understand the dynamics of pollutants parameters (TSS, COD and nitrogen), high frequency monitoring (every five minutes) has been established for one year with turbidity and conductivity sensors. This continuous monitoring is the third part of this work. Correlation functions (r² ≈ 0.9) were found between, the pollutant parameters COD and TSS, and turbidity, and secondly, between conductivity and total nitrogen. These records allowed a better understanding of sanitation system: highlighting the first flush phenomenon, estimation of pollutant loads discharged by CSO, study of storage networks phenomenon. The last part of this thesis aims to study the contribution of wastewater discharges to the receiving environment. It demonstrated the moderate contribution of rejection output STEP (between 1% and 15%) in dry weather. In rainy weather, the contribution of sanitation through CSO is extremely variable depending on the hydro-climatic conditions (<1% to over than 50%). This work has led to provide usable results for the sanitation manager to optimize CDAPP wastewater treatment. Moreover, this work provides most fundamental results for a better understanding of the hydrological and physicochemical dynamics of urban wastewater and associated pollutants such as highlighting, using statistical tools, the parameters influencing pollutant concentrations during rainfall events.
708

Optimization of identification of particle impacts using acoustic emission

Hedayetullah, Amin Mohammad January 2018 (has links)
Air borne or liquid-laden solid particle transport is a common phenomenon in various industrial applications. Solid particles, transported at severe operating conditions such as high flow velocity, can cause concerns for structural integrity through wear originated from particle impacts with structure. To apply Acoustic Emission (AE) in particle impact monitoring, previous researchers focused primarily on dry particle impacts on dry target plate and/or wet particle impacts on wet or dry target plate. For dry particle impacts on dry target plate, AE events energy, calculated from the recorded free falling or air borne particle impact AE signals, were correlated with particle size, concentration, height, target material and thickness. For a given system, once calibrated for a specific particle type and operating condition, this technique might be sufficient to serve the purpose. However, if more than one particle type present in the system, particularly with similar size, density and impact velocity, calculated AE event energy is not unique for a specific particle type. For wet particle impacts on dry or wet target plate (either submerged or in a flow loop), AE event energy was related to the particle size, concentration, target material, impact velocity and angle between the nozzle and the target plate. In these studies, the experimental arrangements and the operating conditions considered either did not allow any bubble formation in the system or even if there is any at least an order of magnitude lower in amplitude than the sand particle impact and so easily identifiable. In reality, bubble formation can be comparable with particle impacts in terms of AE amplitude in process industries, for example, sand production during oil and gas transportation from reservoir. Current practice is to calibrate an installed AE monitoring system against a range of sand free flow conditions. In real time monitoring, for a specific calibrated flow, the flow generated AE amplitude/energy is deducted from the recorded AE amplitude/energy and the difference is attributed to the sand particle impacts. However, if the flow condition changes, which often does in the process industry, the calibration is not valid anymore and AE events from bubble can be misinterpreted as sand particle impacts and vice versa. In this research, sand particles and glass beads with similar size, density and impact velocity have been studied dropping from 200 mm on a small cylindrical stepped mild steel coupon as a target plate. For signal recording purposes, two identical broadband AE sensors are installed, one at the centre and one 30 mm off centred, on the opposite of the impacting surface. Signal analysis have been carried out by evaluating 7 standard AE parameters (amplitude, energy, rise time, duration, power spectral density(PSD), peak frequency at PSD and spectral centroid) in the time and frequency domain and time-frequency domain analysis have been performed applying Gabor Wavelet Transform. The signal interpretation becomes difficult due to reflections, dispersions and mode conversions caused by close proximity of the boundaries. So, a new signal analysis parameter - frequency band energy ratio - has been proposed. This technique is able to distinguish between population of two very similar groups (in terms of size and mass and energy) of sand particles and glass beads, impacting on mild steel based on the coefficient of variation (Cv) of the frequency band AE energy ratios. To facilitate individual particle impact identification, further analysis has been performed using Support Vector Machine (SVM) based classification algorithm using 7 standard AE parameters, evaluated in both the time and frequency domain. Available data set has been segmented into two parts of training set (80%) and test set (20%). The developed model has been applied on the test data for model performance evaluation purpose. The overall success rate of individually identifying each category (PLB, Glass bead and Sand particle impacts) at S1 has been found as 86% and at S2 as 92%. To study wet particle impacts on wet target surface, in presence of bubbles, the target plate has been sealed to a cylindrical perspex tube. Single and multiple sand particles have been introduced in the system using a constant speed blower to impact the target surface under water loading. Two sensor locations, used in the previous sets of experiments, have been monitored. From frequency domain analysis it has been observed that characteristic frequency for particle impacts are centred at 300-350 kHz and for bubble formations are centred at 135 – 150 kHz. Based upon this, two frequency bands 100 – 200 kHz (E1) and 300 – 400 kHz (E3) and the frequency band energy ratio (E3E1,) have been identified as optimal for identification particle impacts for the given system. E3E1, > 1 has been associated with particle impacts and E3E1, < 1 has been associated with bubble formations. Applying these frequency band energy ratios and setting an amplitude threshold, an automatic event identification technique has been developed for identification of sand particle impacts in presence of bubbles. The method developed can be used to optimize the identification of sand particle impacts. The optimal setting of an amplitude threshold is sensitive to number of particles and noise levels. A high threshold of say 10% will clearly identify sand particle impacts but for multiparticle tests is likely to not detect about 20% of lower (impact) energy particles. A threshold lower than 3% is likely to result in detection of AE events with poor frequency content and wrong classification of the weakest events. Optimal setting of the parameters used in the framework such as thresholds, frequency bands and ratios of AE energy is likely to make identification of sand particle impacts in the laboratory environment within 10% possible. For this technique, once the optimal frequency bands and ratios have been identified, then an added advantage is that calibration of the signal levels is not required.
709

Degradation modeling of concrete submitted to biogenic acid attack / Modélisation de la dégradation du béton due aux attaques acidesbiogéniques.

Yuan, Haifeng 03 December 2013 (has links)
La biodétérioration du béton, très courante dans les systèmes d'égouts et de traitement des eaux usées, entraîne une dégradation significative de la structure. Normalement, le processus peut être décrit par les deux étapes suivantes : 1) Des réactions biochimiques produisent des espèces agressives dans les biofilms qui tapissent la surface du béton. L'un des plus importants acides biogéniques que l'on trouve dans les canalisations d'égout est l'acide sulfurique (H2 SO4 ) que est produit par des bactéries sulfo-oxydante (BSO)à partir de l'hydrogène sulfuré (H2 S). 2) Les réactions chimiques entre les espèces agressives biogéniques et les produits d'hydratation du ciment sont responsables de la détérioration du béton. Un modèle de transport réactif est proposé afin de simuler les processus des détériorations chimique et biochimique des matériaux cimentaires en contact avec les BSO et le H2 S ou une solution d'acide sulfurique. L'objectif de ce modèle est de résoudre simultanément le transport et la biochimie / chimie dans les biofilms et les matériaux cimentaires par une approche globale couplée. Afin de fournir un environnement approprié pour la croissance des BSO, la neutralisation de la surface du béton (i.e., l'absorption de H2 S et la corrosion aqueuse de H2 SO4 ) est considérée. Pour obtenir la quantité de H2 SO4 biogénique, la bio-oxydation du H2 S par l'activation des bactéries est simulée par un modèle simplifié. Puis, pour alimenter un environnement convenable pour la croissance des BSO, la réduction abiotique du pH du béton est introduite. Le taux de production de H2 SO4 est régi par la valeur du pH dans les biofilms et la quantité de H2 S dans le gaz. On fait l'hypothèse que tous les processus chimiques sont en équilibre thermodynamique. La dissolution de la portlandite (CH) et du silicate de calcium hydratés (C-S-H), ainsi que la précipitation de gypse (CSH2) et du sulfure de calcium sont décrites par la loi d'action de masse et le seuil des produits d'activité ionique. Pour prendre en compte la décroissante continue du rapport Ca/Si lors de la dissolution de la C-S-H, une généralisation de la loi d'action de masse est appliquée. En simplifiant le processus de précipitation du gypse, un modèle d'endommagement est introduit pour caractériser la détérioration du béton due au gonflement du gypse. Ainsi, l'évolution de la porosité et de la profondeur de la détérioration pendant le processus de dégradation sont pris en compte. Seule la diffusion des espèces aqueuses est considérée. Différents coefficients de diffusion sont utilisés pour divers ions et l'équation de Nernst-Planck est implémentée. L'effet, pendant la détérioration, de la modification de la microstructure sur les propriétés de transport est aussi considéré. Pour les biofilms et les matériaux cimentaires, les équations d'équilibre de masse totale de chaque atome (Ca, Si, S, K, Cl) sont utilisées pour coupler les équations de transport et les réactions (bio) chimiques. Le modèle est implémenté dans un code volumes finis, Bil. Grâce à l'introduction de la méthode des volumes finis, on illustre le couplage du processus bio-chimie dans les biofilms et le processus de la chimiedes matériaux cimentaires. Par ce modèle, certaines expériences rapportées dans la littérature, dont des tests d'immersion chimiques (condition de la solution statique et condition de la solution d'écoulement) et des simulations microbiologiques, sont simulées. Les résultats numériques et les observations expérimentales sont comparés et discutés. L'influence des propriétés des matériaux cimentaires (porosité initiale, couche carbonatée, etc.) et les facteurs d'environnement (concentration de H2 SO4 quantité de H2 S etc) sont aussi étudiés par ce modèle. En outre, une prédiction à long terme est menée / Bio-deterioration of concrete, which is very common in sewer system and waste water treatment plant, results in significant structure degradation. Normally, the process can be described by the two following parts: 1) Biochemistry reactions producing biogenic aggressive species in biofilms which are spread on the surface of concrete. As one of the most significant biogenic acid in sewer pipes, sulfuric acid (H2SO4) is produced by sulfur oxidizing bacteria (SOB). 2) Chemical reactions between biogenic aggressive species and cement hydration products which is responsible for concrete deterioration. A reactive transport model is proposed to simulate the bio-chemical and chemical deterioration processes of cementitious materials in contact with SOB and H2S or sulfuric acid solution. This model aims at solving simultaneously transport and biochemistry/chemistry in biofilms and cementitious materials by a global coupled approach. To provide an appropriate environment for SOB to grow, the surface neutralization of concrete (i.e., the absorption of H2S and aqueous H2S corrosion) is considered. To obtain the amount of biogenic H2SO4, the bio-oxidation of H2S by the activation of bacteria is simulated via a simplified model. To provide a suitable environment for SOB to grow, the abiotic pH reduction of concrete process is introduced. The production rate of H2SO4 is governed by the pH in the biofilms and the content of H2S in gas.It is assumed that all chemical processes are in thermodynamical equilibrium. The dissolution of portlandite (CH) and calcium silicate hydrates (C-S-H) and the precipitation of gypsum (C¯S H2) and calcium sulfide are described by mass action law and threshold of ion activity products. To take into account the continuous decrease of the Ca/Si ratio during the dissolution of C-S-H a generalization of the mass action law is applied. By simplifying the precipitation process of gypsum, a damage model is introduced to characterize the deterioration of concrete due to the swelling of gypsum. Thus, the porosity evolution and deterioration depth during deterioration process are taken into account. Only diffusion of aqueous species are considered. Different diffusion coefficients are employed for various ions and Nernst-Planck equation was implemented. The effect of the microstructure change during deterioration on transport properties is considered as well. For both biofilms and cementitious materials, the balance equations of total mass of each atom (Ca, Si, S, K, Cl) are used to couple transport equations and (bio-)chemical reactions. The model is implemented within a finite-volume code, Bil. Following the introduction of principle of the finite volume method, the coupling of the bio-chemistry process in biofilms and chemistry process in cementitious materials is illustrated. By this model, some experiments reported in literature, including chemical immersion tests (statical solution condition and flow solution condition) and microbiological simulation tests, are simulated. The numerical results and the experimental observations are compared and discussed. The influence of properties of cementitious materials (initial porosity, carbonated layer, etc.) and environmental factors (concentration of H2SO4, content of H2S, etc.) are investigated by this model as well. Furthermore, a long term predictionis conducted
710

Improvisação coral sobre "Victimae Paschali" de Charles Tournemire : uma abordagem analítica e interpretativa para a elaboração de uma edição de performance

Bonamigo, Rudimar January 2014 (has links)
O presente trabalho objetiva elaboraruma edição de performance da Improvisação Coral sobre Victimae Paschali de Charles Tournemire, transcrita pelo seu aluno Maurice Duruflé. A edição de performance foi construída através da análise, escolha de registração e elaboração de exercícios técnicos para os trechos difíceis. O livro Guidelines to Style Analysis de Jan La Rue (1970) foi usado como ferramenta analítica, enfocando os cinco parâmetros fornecidos pelo autor: Som, Harmonia, Melodia, Ritmo e Crescimento. A escolha da registração foi delineada a partir de um estudo do órgão da Igreja Sainte Clotilde de Paris e do órgão da Capela São José do Centro Universitário La Salle (Unilasalle) em Canoas, RS (Brasil). Os exercícios técnicos para os trechos difíceis foram gerados a partir de passagens que apresentaram maior demanda durante meu estudo. Por fim, a edição de performance reúne essas informações junto à partitura de maneira sucinta como síntese do trabalho e da construção da minha performance da obra para recital. / The purpose of this study is to present a performance edition of the Choral Improvisation on Victimae Paschali by Charles Tournemire, transcribed by his pupil Maurice Duruflé. The performance edition was constructed based on analysis, choice of registration and the elaboration of technical exercises for the difficult passages. The book Guidelines to Style Analysis by Jan La Rue (1970) was used as an analytical tool, focusing on the five parameters presented by the author: Sound, Harmony, Melody, Rhythm and Growth. The choice of registration was decided based on a study of the organ at the Sainte Clotilde Church in Paris and the organ at St. Joseph´s Chapel of the La Salle University Center (Unilasalle) in Canoas, RS (Brazil). Technical exercises were generated from the passages that proved to be more demanding for me during my practice. Finally, the performance edition contains all of this information as a summary of my work and the preparation of the piece for performance.

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