Дисертації з теми "GTDL"
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Santos, Rodrigo Alves dos. "Estudo da viabilidade técnica e econômica de produção de petróleo sintético offshore a partir de rejeito rico em CO2." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-11072014-020823/.
Повний текст джерелаThe discovery of a new oil province known as pre-salt, located in the Brazilian coast, represents a new frontier in the world\'s oil production. Among other challenges involved in the exploration and production in that region, the CO2 concentration at high levels in the fluids of some of those reservoirs has been the most relevant challenge for the companies that explore and produce in that area (FORMIGLI, 2007). An alternative to sequestering the CO2 extracted from natural gas is using it as a supply of raw material or as an input to the synthesis of chemical products, especially those with great market demand. One of the products that can be obtained indirectly from CO2 is synthetic fuel, produced by the process known as Gas-to- Liquids, or GTL. In this work the technical, economical and potential feasibility of CO2 capture is analyzed, as well as the production of synthetic fuel using the GTL process, offshore, from carbon dioxide (CO2) and methane (CH4), found in the waste chain of the gas treatment in an oil and gas production platform, through dry and steam reforming, followed by Fischer-Tropsch synthesis. Thus, based on literature data and on the use of a commercial process simulator, the simulation of the suggested process was developed and different alternatives to the reutilization of the waste chains were analyzed, including the recycling and burning of some effluent streams. Techniques of energetic integration, optimization and economic analysis of process have also been applied. The results indicated that the process, mass and energy integrated in the condition of lower CO2 emissions and greater financial return, produced synthetic oil in a technically and economically feasible way. The results also indicated that the GTL process, with the technologies used, is not suitable as a method for CO2 capture due to the fact that the generation of this component for the production of synthetic oil is two times greater than the amount fed.
Wang, Xiaonian. "Computer simulation of GTL and various problems in thermodynamics." Texas A&M University, 2003. http://hdl.handle.net/1969.1/2210.
Повний текст джерелаGerry, Michael J. "Two-dimensional inverse scattering based on the GTD model /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487946103567201.
Повний текст джерелаQuintero, Soltero Oscar. "Microstructural characterization of overaged GTD-111 HP turbine buckets." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Повний текст джерелаAsari, Satoshi. "Evaluation of the GTL technology for use in the *T Network." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/36511.
Повний текст джерелаBao, Buping. "Simulation, integration, and economic analysis of gas-to-liquid processes." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3131.
Повний текст джерелаPresotto, Alice. "Efeitos de campos magnéticos externos e de correntes de transporte na dinâmica de vórtices em uma constrição mesoscópica /." Ilha Solteira, 2017. http://hdl.handle.net/11449/151624.
Повний текст джерелаResumo: Com o desenvolvimento científico, a fabricação de materiais em escalas nano e submicrométricas tornou-se uma realidade. Nos estudos teóricos e experimentais de materiais supercondutores, tais sistemas são denominados de mesoscópicos, e possuem tamanhos da ordem dos seus comprimentos característicos, i.e., λ(T) e ξ(T). Nessas escalas, a dinâmica de vórtices é fortemente dominada por efeitos de confinamento. Dessa forma, a investigação de suas características tem importância fundamental para o desenvolvimento e aplicação desses materiais de forma eficaz. Assim, neste trabalho foram estudados os efeitos da passagem de uma corrente de transporte por uma constrição de tamanhos mesoscópicos, que foi produzida inserindo dois defeitos (normalizando 0<ψ<1 dentro do defeito) nas bordas opostas do sistema. Para tal, simulamos amostras supercondutoras mesoscópicas na presença de correntes de transporte e de campos magnéticos solucionando a equação generalizada de Ginzburg-Landau dependente do tempo (GTDGL). Sem campo magnético aplicado, os pares de vórtices cinemáticos são formados nos defeitos e se aniquilam no centro da amostra. Por outro lado, quando um baixo campo magnético é aplicado, produz uma assimetria na distribuição das correntes supercondutoras. Então, apenas o vórtice cinemático é formado em uma borda da amostra e a deixa pela lateral oposta. Contudo, antes de deixar o sistema, o vórtice cinemático experimenta um efeito de barreira superficial, que causa uma diminuição em su... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: With the scientific development, the fabrication of materials at nano and sub-micrometer scales become a reality. In theoretical and experimental study of superconducting materials, such systems are called mesoscopic and have sizes of the order of their characteristic lengths, i.e., λ(T) and ξ(T). In these scales, the vortex dynamics is strongly dominated by confinement effects. In this way, the investigation of their characteristics have fundamental importance for the development and application of these materials effectively. Then, in this work we studied the effect of a transport current flowing through a mesoscopic constriction, which was produced by inserting two defects (normalizing 0<ψ<1 inside the defect) on the opposite edges of the system. The mesoscopic superconducting samples were simulated in the presence of transport currents and applied magnetic fields by solving the time-dependent Ginzburg-Landau equation in its generalized form (GTDGL). At zero applied magnetic field, kinematic vortex-antivortex pairs are formed at the defects and annihilate at the center of the sample. On the other hand, small external magnetic fields produce an asymmetry in the distribution of the superconducting currents. Then, only one kinematic vortex is nucleated in one of the borders of the sample and leaves it by the opposite side. However, before leaves the system, the kinematic vortex experiences a surface barrier effect, which causes a decrease in its velocity. The results obtained... (Complete abstract click electronic access below)
Mestre
Presotto, Adriana Guirao. "Resposta magneto-elétrica de nanofitas supercondutoras granulares : simulações utilizando o formalismo de Ginzburg-Landau dependente do tempo /." Ilha Solteira, 2020. http://hdl.handle.net/11449/192560.
Повний текст джерелаResumo: Correntes de transporte interagem com os vórtices de Abrikosov nos supercondutores do tipo II via força de Lorentz (FL), o que pode resultar em seu movimento. Esse movimento ocorrerá se FL suprimir a força de pinning (FP) [4,6], que mantém os vórtices ancorados, tais como defeitos e orifícios artificiais nas amostras. Nos casos em que FL >> FP, os vórtices se movem livremente e experimentam apenas resistência viscosa devido à sua interação com o condensado supercondutor. Esse estado de movimento é conhecido como flux flow (FF). Assim, no presente trabalho, estudamos a dinâmica dos vórtices em uma fita supercondutora com tamanhos laterais de 10 ξ(0) x 70 ξ(0), com seis grãos espaçados por um supercondutor de menor Tc, i.e., um weak-link (WL). Além disso, em cada grão foram considerados quatro defeitos da mesma natureza que os WL’s, simulando defeitos intrínsecos. Para tal estudos, as equações generalizadas de Ginzburg-Landau dependentes do tempo (GTDGL) foram solucionadas numericamente. Assim, foram considerados três valores diferentes de campos magnéticos externos, i.e., Hap = 0,1 Hc2(0), 0,3 Hc2(0) e 0,5 Hc2(0), e densidade de correntes de transporte de intensidade que variou em passos de 0,005J0. Observou-se que a intensidade de Hap, influencia diretamente nos regimes de movimento, onde para Hap = 0,1 Hc2(0) foi verificado apenas o FF intergranular e uma dinâmica mais duradoura. Já para Hap = 0,3 Hc2(0) e 0,5 Hc2(0) foram observados dois regimes de movimento, o flux flow (F... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Transport currents interact with Abrikosov vortices in type II superconductors via Lorentz force (FL), which can result in their motion. Such movement will occur if FL suppresses the pinning force (FP) [4,6], which keeps vortices trapped, such as defects and artificial holes in the samples. In cases where FL >> FP, the vortices move freely and experience only a viscous resistance due to their interaction with the superconducting condensate. This state of motion is known as flux flow (FF). Thus, in the present work, we studied the vortex dynamics a superconducting tape with lateral sizes of 10 ξ(0) x 70 ξ(0), with six grains spaced by a smaller Tc superconductor, i.e., a weak-link (WL). In addition, in each grain, four defects of the same nature as the WL's were considered, simulating intrinsic defects. For such studies, the generalized time-dependent Ginzburg-Landau equations (GTDGL) were solved numerically. Thus, three different values for the external magnetic field were considered, i.e., Hap = 0.1 Hc2(0), 0.3 Hc2(0) and 0.5 Hc2(0), and density of transport currents of intensity that varied in steps of 0,005 J0. It was observed that the intensity of Hap directly influences the motion regimes, where for Hap = 0.1 Hc2 (0) it was verified only the intergranular FF and a longer dynamics. For Hap = 0.3 Hc2(0) and 0.5 Hc2(0), two motion regimes were observed, the inter and intragranular FF. However, there was a faster destruction of the superconductor (SC). It was also found that... (Complete abstract click electronic access below)
Mestre
COSTA, LETICIA DE ALMEIDA. "VALUATION OF GTL PROJECT: A REAL OPTION APLICATION WITH MEAN REVERSION MODEL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10096@1.
Повний текст джерелаO Presente trabalho tem como objetivo analisar a viabilidade econômica de uma planta XTL usando a teoria das Opções Reais. Esta metodologia é a mais adequada para avaliar a capacidade que este tipo de projeto dispões de trocar de input e/ou output, ou seja, eleger a cesta que maximiza o resultado final, de acordo com cada cenário. Essa política ótica permite avaliar a construção de uma planta com flexibilidades, com o investimento ocorrendo em um ambiente de incerteza, onde os preços (fatores de incerteza) serão considerados estocáticos e seguirão um Movimento de Reversão à Média. Os cálculos numéricos serão feitos através da simulação de Monte Carlo. A tecnologia, designada XTL, está dividida em duas etapas: um processo de gaseificação seguido de um processo GTL (gás-to- liquid). A gaseificação permite transformar sólidos, líquidos e gases em gás de síntese, que será usado como input do GTL. Já o GTL possibilita transformar o gás de síntese em líquidos de alta qualidade, tais como nafta, diesel, parafinas e lubrificantes. Por associação, esta dissertação faz parte de um projeto que visa aplicar a teoria de Opções Reais na avaliação de investimentos em Pesquisa e Desenvolvimento (P&D), com a finalidade de valorar e considerar as flexibilidades inerentes a este tipo de projeto.
The present work has objective to analyze the investiment of a XTL plant using the Real Options Theory. This methodology is adjusted to evaluate the capacity that this project has to changes its input and/or output, in other words, to elect the option that maximizes payoff, in accordance with each scenario, allowing to evaluate the construction of a plant with flexibilities with the investiments happening in an environment of economical and/or technical uncertainties, where the prices (uncertainty factors) are stochastic and will follow the Mean Reversion Model, calculated by the Monte Carlo Simulation. The XTL technology is divided in two stages: a gasification process followed by a GTL (gas-to-liquid) process. The gasification process allows you to transform solids, liquids and gases into synthesis gas, that will be used as input of the GTL. The GTL makes possible to transform the syntesis gas into high quality liquids, such as naphtha, diesel, paraffins and lubrificants. This work is part of a project, with the objective to apply the Real Options Theory in the evaluation of investiments in Research and Development (R&D), aiming to price and consider the flexibilities that are inherent to this project.
Karabanova, Anastasiya. "The Effectiveness of Small-scale GTL Technologyin Remote Small Fields of Russia." Thesis, KTH, Energiteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210216.
Повний текст джерелаI avhandlingen uppenbaras problemet med tillhörande petroleumsgaser både i Ryssland och i världen. Analysen av tillhörande oljeutnyttjande metoder för de små avlägsna oljefälten utförs. Avhandlingen visar perspektivet på att skapa låga och medelkraftiga autonoma installationer för energiförsörjning till oljeanläggningarna i de avlägsna områdena med dåligt utvecklad energiinfrastruktur genom att bearbeta tillhörande oljegas i småskaliga GTL-teknologienheten. Med tanke på särdrag hos små avlägsna oljefält valdes GTLteknikprogrammet bland befintliga typer och dess materialbalans beräknades. Systemen för både tillhörande oljeutnyttjande och kraftproduktion på plats i de små avlägsna fälten föreslogs och jämfördes med varandra från ekonomiska och miljömässiga perspektiv. Vidare definierades den ekonomiska effekten från mini-GTLteknikintroduktionen i systemen.
Bassey, Michael Etim. "Economic viability of a floating gas-to-liquids (GTL) plant / Bassey, Michael Etim." Thesis, North-West University, 2007. http://hdl.handle.net/10394/1577.
Повний текст джерелаVALE, SILVIO FRANKLIN MONCAO DO. "PRECIFICATION OF MANAGERIAL FLEXIBILITY IN GTL PLANTS USING THE METHODOLOGY OF REAL OPTIONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=11861@1.
Повний текст джерелаO objetivo da presente dissertação é capturar o valor da opção de parada temporária que uma planta GTL oferece em cenários econômicos desfavoráveis para mantê-la operando. Desta forma, o autor considera que a metodologia das opções reais é a mais indicada para avaliar tal flexibilidade, sendo assim, o objetivo principal deste estudo é a análise da opção de parar temporariamente através da utilização do processo estocástico (Movimento geométrico Browniano)e a correlação de Cholesky entre cada input e os outputs da planta. O autor acredita que os resultados desta dissertação podem auxiliar os gestores que enxergam flexibilidades em seus projetos a antecipar prejuízos prolongados em cenários desfavoráveis para manter uma planta funcionando.
The objective of this dissertation is to capture the value of the option to temporarily stop that a GTL plant offers in unfavorable economic scenarios to keep it operating. Thus the author believes that the methodology of real options is the best placed to assess such flexibility, and thus the main objective of this study is the analysis of the option to temporarily stop using the stochastic process (geometric Brownian Motion) and the correlation Cholesky between each input and outputs of the plant. The author believes that the results of this dissertion can assist the managers who see flexibilities in its projects to anticipate damages drawn out in favorable scenes to keep a plant functioning.
SALES, Deivson Cesar Silva. "Desenvolvimento da tecnologia GTL de produção de metanol a partir do gás de síntese." Universidade Federal de Pernambuco, 2013. https://repositorio.ufpe.br/handle/123456789/10386.
Повний текст джерелаMade available in DSpace on 2015-03-04T14:21:20Z (GMT). No. of bitstreams: 2 TESE Deivson César Silva Sales.pdf: 2799787 bytes, checksum: 3c6c2f46e7b800b1bb027de8d9d6e0e2 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013
CAPES
Tendo em vista o desenvolvimento de uma abordagem diferente da convencional adotada para a síntese do metanol, justificado pelo crescimento do mercado de consumo e produção dessa matéria prima, foi desenvolvido um processo de síntese via gás de síntese em reator de mistura. Nesse processo, o leito catalítico foi posicionado em um cesto no interior do reator, que girava em rotações pré-determinadas, entre 200 – 800 RPM, onde foram conduzidas avaliações cinéticas. Operando-se com um catalisador comercial (KATALCOJM 51-8), nas condições definidas por meio de avaliações termodinâmicas, de equilíbrio líquido-vapor e fluidodinâmica, foi determinada a região de operação do sistema, estabelecida em pressões na faixa de 20,0 – 30,0 atm e temperaturas de 473 – 573 K, com base em um planejamento fatorial 3². Foram conduzidas, nessas condições, avaliações dos efeitos de resistência externa, por influência da velocidade de rotação do cesto catalítico, via quantificação do número de Biot. Avaliações do regime de operação nessas condições também indicaram o estabelecimento do regime químico de operação, com domínio da reação catalítica, via determinação do módulo de Thiele modificado. Em operação descontínua com uso do catalisador comercial, produziu-se metanol com conversão média de CO e H2, rendimento e seletividade médios a metanol iguais a 86%, 96%, 39% e 70%, respectivamente a 30,0 atm e 523 K. Foram formulados catalisadores baseados em Cu e Zn sobre γ-alumina, preparados pelo método de impregnação úmida e caracterizados via análises de difração de raios-x, espectrofotometria de absorção atômica e propriedades texturais (área superficial, volume de poros, volume de microporos e raio médio de poros). Em operação descontínua, esses catalisadores tiveram suas atividades catalíticas avaliadas, alcançando conversão de CO, rendimento e seletividade médios a metanol iguais a 32,5%, 25% e 85%, respectivamente. Foram desenvolvidos modelos cinéticos para predição do comportamento dos reagentes e produtos no processo, em termos do modelo de Langmuir-Hinshelwood-Hougen-Watson, a partir dos quais foi possível a quantificação dos parâmetros cinéticos e de equilíbrio. Esses modelos foram estendidos à predição do comportamento das operações em regime contínuo, conduzidas para o catalisador comercial e aqueles formulados.
Souza, Jos? Roberto de. "S?ntese de Fischer-Tropsch sobre perovskitas LayCu0,4Fe0,6O3." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15905.
Повний текст джерелаThe current natural gas production of 52 Mm3d-1 and the large projects for its expansion has been setting new boundaries for the Brazilian industry of oil and gas. So far, one of the biggest challenges regards to the logistics for gas transportation from offshore fields. Therefore, the transformation of natural gas into gasoline, diesel and/or olefins via Fischer-Tropsch synthesis would be an alternative to this matter. In this work, the production of hydrocarbons by Fischer-Tropsch synthesis in a slurry reactor was investigated and a perovskite-type catalyst (LayCu0,4Fe0,6O3 ? d) was used with y varying from 0 to 1 on a molar basis. In addition, Nb2O5 support was also applied in order to observe the selectivity of the produced hydrocarbons by the Fischer-Tropsch process. It is shown that the hydrogen conversion was influenced by the support as well as the different phases of the samples. The kinetic results for the CO2 production suffered great influence with the introduction of the Nb2O5 support throughout the series of samples studied. The catalysts allowed obtaining welldefined cuts of hydrocarbons in the range of C1-C6 and C17-C28, and these results were clearly influenced by the support and the lanthanum content. The higher olefin/paraffin ratio obtained was 1.8 when using a non-supported perovskite with y equal to 0.8. This would indicate the suitability of using this material for the production of olefins
A produ??o atual de 52 milh?es m?dia-1 de g?s natural e os grandes projetos para esta expans?o vem estabelecendo novas fronteiras para a ind?stria nacional de petr?leo e g?s, sendo um dos maiores desafios a log?stica para o transporte do g?s oriundo de campos offshore. Uma alternativa seria usar o g?s natural para a produ??o de gasolina, diesel e/ou olefinas atrav?s da s?ntese de Fischer-Tropsch. No desenvolvimento deste trabalho foi investigado a produ??o de hidrocarbonetos via s?ntese de Fischer-Tropsch em um reator slurry mediante uso de catalisadores do tipo perovskita, LayCu0,4Fe0,6O3?d, onde y sofreu varia??o de 0 at? 1 em base molar. A s?ntese dos catalisadores levou em considera??o o estudo da influ?ncia do teor de lant?nio e do suporte (Nb2O5) na atividade e seletividade da rea??o de Fischer-Tropsch, objetivando a produ??o de hidrocarbonetos. As convers?es de H2 foram sensivelmente influ?nciadas pela presen?a de fases existentes em cada amostra, assim como pelo suporte. Os resultados da cin?tica de produ??o de CO2 sofreram grandes influ?ncias com a introdu??o do suporte em toda a s?rie das amostras produzidas. Os catalisadores empregados permitiram a obten??o de cortes bem definidos de hidrocarbonetos na faixa de C1-C6 e C17-C28, sendo estes resultados claramente influenciados pelo suporte e pela varia??o do teor de lant?nio. A maior rela??o olefina/parafina obtida foi de 1,8 para a perovskita com y igual a 0,8 na amostra n?o suportada, viabilizando o uso deste material na produ??o de olefinas
Francis, Michael Craig. "A techno–economic analysis of an integrated GTL, nuclear facility with utilities production / Francis M.C." Thesis, North-West University, 2011. http://hdl.handle.net/10394/7347.
Повний текст джерелаThesis (M.Sc. Engineering Sciences (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2012.
FRANCISCO, MARCELA LOBO. "THE IMPORTANCE OF MANAGERIAL FLEXIBILITY: INVESTIMENT ANALYSIS USING THE REAL OPTION OF THE PLANT GTL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10099@1.
Повний текст джерелаPETRÓLEO BRASILEIRO S. A.
O objetivos desta dissertação é fazer uma análise de investimentos usando a teoria das Opções Reais de uma planta GTL. Está análise é a mais indicada, pois se verificam várias flexibilidades nesta planta em relação aos inputs (pode ser usado mais de um produto como matéria- prima) e em relação aos outputs (existem várias combinações possíveis de produção). Torna-se de grande importância neste caso saber calcular o valor destas opções e verificar se vale a pena ou não a construção de uma planta que possa usar como matéria prima mais de um produto e/ou que possa produzir mais de uma possível combinação de produção. A construção de uma planta que possua a possibilidade de trocar de insumo e/ou trocar a combinação de produção só será viável caso o valor criado pela flexibilidade seja maior do que o custo necessário para implementá-la (investimento adicional e custos operacionais extras). Sendo assim, o objetivo desta dissertação é calcular até quanto a Petrobras estaria disposta a pagar para ter uma planta que possua a opção de swicth use dos inputs e/ou outputs, o valor que ela teria que investir para usufruir desta flexibilidade, e através da diferença entre estes valores verificar se vale a pena ou não a construção da planta com flexibilidade de input e/ou output.
The objective of this dissertation is to do a analysis of investiment using the real option theory for the plant GTL. This analysis is the best because there are many flexibilities in this plant in relation the inputs (the plant can operate with several inputs) and in relation the outputs (there are many possible combination of production). In this case is very important to know how to calculate the value of these options and to verify if it is worthwhile or not the construction of a plant that could use two inputs and/or is able to procuce several possible combinations of production. The construction of the plant that change the input abd /or can changer the production combination is viable if the value created by flexibility is large than the necessary cost to implement its (additional investiment and extra operational costs). So, the objective of this dissertation is to calculate until hen Petrobras would be avaible to pay in order to have a plant that has the option of swicth use of inputs and/or outputs, the value it would have to invest to use this flexibility, and through the difference between these values verify if is worthwhile or not the construction of the plant with the flexibility of input and/or output.
Souto, Vinícius Suzuki. "Efeito de constrições na dinâmica de vórtices cinemáticos em supercondutores gap-like e gapless." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153801.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Nesse trabalho estudou-se a dinâmica e os fatores de formação de vórtices cinemáticos em supercondutores mesoscópicos sem gap (gapless). Os resultados foram comparados com aqueles de um sistema com gap (gap-like). Para tal, as simulações computacionais foram direcionadas para a solução das equações generalizadas de Ginzburg-Landau dependente do tempo (GTDGL). Primeiramente simulamos amostras homogêneas onde verificou-se que, no sistema gap-like, as correntes se concentram no centro da amostra, com isso, há formação de vórtices cinemáticos. Para criar artificialmente o acúmulo de correntes no centro da amostra, inserimos uma constrição e assim, obtivemos a formação de vórtices cinemáticos em supercondutores gapless. A dinâmica é sempre com um par se formando nas bordas da amostra e se aniquilando no centro. Nota-se que, além da formação de VAv (início do estado resistivo) ocorrer em valores distintos da densidade de corrente aplicada para as diferentes amostras, a corrente crítica apresenta uma pequena diferença entre as amostras gapless e gap-like. Vale ressaltar que parâmetros como o tamanho dos contatos elétricos e a constrição afetam a corrente crítica da amostra, bem como a velocidade média do vórtice cinemático.
In this work we study the dynamics and the formation of kinematic vortices in gapless mesoscopic superconductors. The results were compared to those ones of a gap-like system. Then computational simulations were carried out to solve the Generalized Time-Dependent Ginzburg-Landau equations (GTDGL). Firtly, we simulated homogeneous gap-like and gapless samples where it was found that, in the rst one, the currents concentrate in the center of the sample and then, there was the formation of kinematic vortices. To arti cially promote the crowding of the currents in the center of the sample, we worked with samples a constriction. In this way, kinematic vortices in gapless superconductors were formed. The dynamic is always with a pair forming at the edges of the sample and annihilating in the center. It is noted that, besides the formation of a vortex (antivortex) (begin of resistive state) occurs at distinct values of the applied current density for diferent samples, the electric critical current presents a tiny di erence between gapless and gap-like samples. It is worth mentioning that parameters such as the size of electrical contacts and constriction a ect the critical current of the sample as well as the average velocity of the kinematic vortex.
131002/2016-3
Sefi, Sandy. "Pay tracing tools for high frequency electromagnetics simulations." Licentiate thesis, KTH, Numerical Analysis and Computer Science, NADA, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1596.
Повний текст джерелаOver the past 20 years, the development in ComputationalElectromagnetics has produced a vast choice of methods based onthe large number of existing mathematical formulations of theMaxwell equations. None of them dominate over the others,instead they complement each other and the choice of methoddepends on the frequency range of the electromagnetic waves.This work is focused on the most popular method in the highfrequency scenario, namely the Geometrical Theory ofDiffraction (GTD). The main advantage of GTD is the ability topredict the electromagnetic field asymptotically in the limitof vanishing wavelength, when other methods, such as the Methodof Moments, become computationally too expensive.
The low cost of GTD is due to both the fact that there is noruntime penalty in increasing the frequency and that the raytracing, which GTD is based on, is a geometrical technique. Thecomplexity is then no longer dependent on electrical size ofthe problem but instead on geometrical sub problems which aremanageable. For industrial applications the geometricalstructures, with which the rays interact, are modelled bytrimmed Non-Uniform Rational B-Spline (NURBS) surfaces, themost recent standard used to represent complex free-formgeometries.
Due to the introduction of NURBS, the geometrical subproblems tend to be mathematically and numerically cumbersome,but they can be highly simplified by proper Object Orientedprogramming techniques. This allowed us to create a flexiblesoftware package, MIRA: Modular Implementation of Ray Tracingfor Antenna Applications, with an architecture that separatesmathematical algorithms from their implementation details andmodelling. In addition, its design supports hybridisationtechniques in combination with other methods such as Method ofMoment (MoM) and Physical Optics (PO).
In a first hybrid application, a triangle-based PO solveruses the shadowing information calculated with the ray tracerpart of MIRA. The occlusion is performed between triangles andtheir facing NURBS surfaces rather than between their facingtriangles, thus reducing the complexity. Then the shadowinginformation is used in an iterative MoM-PO process in order tocover higher frequencies, where the contribution of theshadowing effects, in the hybrid formulation, is believed to bemore significant.
Thesis presented at the Royal Institute of Technology ofStockholm in 2003, for the degree of Licentiate in ScientificComputing.
Balchen, Olave Leif Andrés. "Estrategia de rediseño a macroproceso de comercialización e instalación de servicios para la empresa Grupo Gtd." Tesis, Universidad de Chile, 2014. http://repositorio.uchile.cl/handle/2250/116327.
Повний текст джерелаGrupo Gtd ha entrado en una fusión de sus áreas comerciales en sus empresas relacionadas, dejando una sola columna vertebral de instalación. La problemática surge cuando un ejecutivo se relaciona a servicios del grupo, y los sistemas hoy no interactúan entre sí. De aquí surge la necesidad de hacer un diseño estratégico de procesos de comercialización e instalación de servicios para la empresa grupo Gtd, de modo tal que mejore el funcionamiento de los sistemas de ingreso de productos y estos cumplan con los requerimientos de los clientes, mediante la innovación y el rediseño de procesos. Para el desarrollo de esta propuesta, se desarrollará un levantamiento de los procesos del macroproceso que refleje las características de la cadena de valor, y luego se pretende desarrollar un modelo que de soporte al rediseño de la cadena de valor. Este modelo basado en la Metodología de Oscar Barros El resultado esperado es por un lado influir en los tiempos de espera del cliente, disminuyendo de 15 a 10 días los tiempos de instalaciones, dejándolo más cercano a los plazos de mercado. Y por otro lado, rediseñar los flujos de comunicación interna en un proceso centralizado, con la cualidad de ir al área competente desde el primer momento, evitando una asignación incorrecta. Dado lo anterior, la eficiencia en la gestión es disminuir los tiempos tanto en las contrataciones como en las espera en los requerimientos de postventa, por lo menos aumentar la satisfacción de clientes en un 30 %. Y al disminuir la probabilidad de que se entregue la información con error se pretende bajar costos de operación en un 20 %. La mejora de los tiempos de instalación debe ser continua, no basta con igualarse al mercado, se deben hacer los esfuerzos para una segunda fase y llegar a tiempos de 8 días. Esto se puede ir logrando a medida que se adquieren los aprendizajes de los procesos y cambian las culturas en las personas, le da una fortaleza diferenciadora para seguir realizando otros cambios internos que le permitirá un crecimiento gradual y controlado para conseguir liderazgo importante en la industria.
Panahi, Mehdi. "Plantwide Control for Economically Optimal Operation of Chemical Plants : - Applications to GTL plants and CO2 capturing processes." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for kjemisk prosessteknologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15210.
Повний текст джерелаTruntzler, Marion. "Identification de locus impliqués dans la qualité du maïs enlisage : méta-analyse de GTL et génétique d'association." AgroParisTech, 2011. http://www.theses.fr/2011AGPT0013.
Повний текст джерелаQuality of silage corn is a trait of major interest for corn breeding in Europe. In order to increase breeding efficiency, it is important to locate precisely the loci (QTL) involved in the variation of this trait and to identify those that carry favorable alleles at these QTL. The goal of this PhD was to carry out two complementary approaches. First, a meta-analysis was performed on the QTL detected in previous studies issued from publications and Syngenta, in order to refine the chromosomal regions involved in traits related to digestibility. Maize physical map and sequence data were used to identify and position candidate genes for silage quality, and to test their colocalization with metaQTL. A total of 37 and 54 metaQTL were found for digestibility and cell wall respectively and the candidate genes colocalized significantly with the metaQTL confidence intervals. Secondly, association mapping was performed on the regions identified through meta-analysis. The panel used for the association tests was composed of 314 inbred lines representing dent European and American germplasm, including public inbred lines and elite material of Syngenta. More than 100 amplicons were analysed in the regions of interest over the whole panel and tested for their association with digestibility traits. Association between flowering time and sequences studied by Ducrocq et al. (2008) at the Vgt1 QTL region were also investigated to evaluate the properties of this panel relative to the ones previously published and to compare different association mapping software. Our results confirm the effect of the Vgt1 region. Nine significant associations were found for digestibility related traits
Kato, Stephen. "A GTD solution to scattering of plane waves at oblique incidence by a dielectric coated circular cylinder." The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345562403.
Повний текст джерелаLiang, Ming-Cheng. "A generalized uniform GTD ray solution for the diffraction by a perfectly-conducting wedge with convex faces /." The Ohio State University, 1988. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487594970650836.
Повний текст джерелаEkbom-Claesson, Åsa, and Kristina Kronestrand. "När graviditeten blir patologisk : kvinnors upplevelse och faktorer som påverkar livskvalitén när graviditeten blir en gestational trofoblastsjukdom (GTD)." Thesis, Sophiahemmet Högskola, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:shh:diva-3065.
Повний текст джерелаWiart, Joe. "Propagation des ondes radioelectriques en milieu urbain dans un contexte microcellulaire. Analyse par la gtd et validation experimentale." Paris 6, 1995. http://www.theses.fr/1995PA066488.
Повний текст джерелаRojas-Teran, Roberto G. "A uniform GTD analysis of the EM diffraction by a thin dielectic/ferrite half-plane and related configurations /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487259580264106.
Повний текст джерелаBoström, Lukas. "Understanding Educational Causes of Terrorism : An empirical analysis investigating the global relationship between specific educational attributes and its effects on domestic terrorism activity." Thesis, Uppsala universitet, Institutionen för freds- och konfliktforskning, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-373040.
Повний текст джерелаKander, Keethan. "Utilizing nuclear process heat to reduce the CO2 generated by an SMR process in a GTL environment / K. Kander." Thesis, North-West University, 2010. http://hdl.handle.net/10394/4859.
Повний текст джерелаThesis (M.Sc. Engineering Sciences (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2010.
Wiart, Joe. "Propagation des ondes radio-électriques en milieu urbain dans un contexte microcellulaire : analyse par la GTD et validation expérimentale /." Paris : École nationale supérieure des télécommunications, 1996. http://catalogue.bnf.fr/ark:/12148/cb35827751c.
Повний текст джерелаThèse délivrée en association avec l'Université de Paris 6. Annexes en français et en anglais. Notes bibliogr. Résumés en français et en anglais.
Quiroga, Gelsio Pereira. "Uso de gás natural para produção de óleo diesel no Brasil a partir da rota gás-to-liquids: estudo de viabilidade técnico-econômica usando reservas do Pré-sal." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/106/106131/tde-11112016-090137/.
Повний текст джерелаThe usage of natural gás (NG) is related to the distance to the final customers, that is a real obstacle to its full utilization which is beyond the usage as fuel for electricity or heat generation. It is important to prospect, analyze and propose new methods for distribution and transformation of this important energy suppy to more value added products or special raw material for the chemical industry. The transformation in ready for use liquid fuels like diesel, gasoline and kerosene through the gas-to-liquid route (GTL) is one of the options. This dissertation evaluates the GTL technology in a context of the NG additional volume available through 2 new pipelines coming from offshore, Rota 2 and Rota 3 in the Brazilian context of NG current usage and its future perspectives taking advantage of this additional availability via the traditional and long term tested GTL Fischer-Tropsch (FT) technology. A GTL FT Diesel plant operating for 30 years was taken as an example considering different scenarios for NG and Oil prices retrieved from the IEA data base that is internationally considered as a consistent source of information.
IMBELLONI, Rosa Maria. "Paradigmas do desenvolvimento no Nordeste : Do GTDN ( Grupo de Trabalho para o Desenvolvimento Econômico do Nordeste) ao GTI (Grupo de Trabalho Interministerial para recriação da SUDENE)." Universidade Federal de Pernambuco, 2008. https://repositorio.ufpe.br/handle/123456789/9515.
Повний текст джерелаConselho Nacional de Desenvolvimento Científico e Tecnológico
Neste trabalho construímos reflexão sobre as transformações ocorridas no Nordeste, com enfoque na questão das desigualdades regionais. Para tanto, analisamos as propostas de políticas de desenvolvimento direcionadas à SUDENE (Superintendência do Desenvolvimento do Nordeste). Um marco para análise refere-se à primeira proposta de criação da SUDENE, elaborada pelo Grupo de Trabalho para o Desenvolvimento do Nordeste (GTDN) no final da década de 50 e, portanto, refere-se ao modelo desenvolvimentista, com a proposta Uma Política de Desenvolvimento Econômico para o Nordeste . Outro marco de análise refere-se à proposta de recriação da SUDENE, elaborada pelo GTI (Grupo de Trabalho Interministerial para Recriação da SUDENE), em 2003 e apresenta um novo modelo de desenvolvimento para o Nordeste com a proposta Bases para a Recriação da SUDENE Por uma Política de Desenvolvimento Sustentável para o Nordeste . A pesquisa é qualitativa com análise de conteúdo e tem como referência os documentos que apresentam as duas propostas de política de desenvolvimento para o Nordeste no processo de criação e recriação da SUDENE. O propósito é refletir os dois modelos de desenvolvimento implantados na região assim como, confrontar as duas propostas de política de desenvolvimento. Entre possibilidades e limites, entendemos que o modelo de desenvolvimento elaborado pelo GTI para o Nordeste representa um novo marco de transformações intervencionistas na região
Lira, Rodrigo Lucas Tenorio Calazans de. "Análise e Otimização da Produção de Hidrocarbonetos Líquidos Via a Reação de Fischer Tropsch Por Meio da Tecnologia Gas To Liquid (GTL)." Universidade Federal de Pernambuco, 2012. https://repositorio.ufpe.br/handle/123456789/11916.
Повний текст джерелаMade available in DSpace on 2015-03-11T14:35:25Z (GMT). No. of bitstreams: 2 Dissertação Completa_Rodrigo.pdf: 2042384 bytes, checksum: adeaba5f9e93bef7dcc818744781565e (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012-05-31
A tecnologia de produção de combustíveis sintéticos iniciou seu desenvolvimento a partir de 1919, na Alemanha, tendo o carvão mineral como insumo para a gaseificação. Com o passar dos anos novos insumos foram utilizados, como a biomassa e o gás natural, cada um com rotas tecnológicas próprias. Com o uso do gás natural esta rota tecnológica é conhecida como Gas-To- Liquids (GTL) sendo uma transformação química que gera faixas de hidrocarbonetos líquidos e estáveis à temperatura e pressão ambientes. Este processo tem como etapa principal etapa à reação de Fischer Tropsch (FT), pois transforma gás síntese resultante da reforma do gás natural em hidrocarbonetos líquidos que ao serem refinados tornamse importantes produtos para indústria petroquímica, de transporte e áreas afins. Essa transformação pode ser realizada no próprio local de produção do gás, evitando investimentos e problemas ambientais na construção de gasodutos. No Brasil, o gás natural apresenta crescente incremento da sua produção, e forte aumento das suas reservas, como por exemplo, a descoberta do pré-sal e o gás natural presente pode estar tanto associado quanto não-associado ao petróleo. Devido às estruturas de plataformas normalmente se localizarem em áreas remotas, torna-se custoso o aproveitamento desse gás que é liberado pela produção do óleo, sendo o mesmo queimado ou ventado. Devido às restrições estabelecidas pela legislação ambiental, a queima do gás natural nas plataformas de produção passa a ser problemática e crítica. Este trabalho teve como objetivo desenvolver e avaliar por meio de simulação computacional uma planta de GTL na produção de hidrocarbonetos líquidos via a reação de FT e utilizá-lo na otimização do processo, na busca por um processo com maior capacidade produtiva e com menores gastos energéticos, gerando um melhor aproveitamento do gás natural, produzindo materiais com maior valor agregado. Foram utilizados os softwares de simulação MATLAB® e HYSYS®, que permitiram a analise de resultados satisfatórios para a conversão e distribuição de hidrocarbonetos gerados em comparação com o descrito pela literatura. A qualidade dos hidrocarbonetos gerados foi analisada pela avaliação do diesel obtido.
Van, Niekerk Bertina Freda. "Functional and structural diversity of the microbial communities associated with the use of Fischer–Tropsch GTL Primary Column Bottoms as process cooling water / van Niekerk B.F." Thesis, North-West University, 2011. http://hdl.handle.net/10394/7284.
Повний текст джерелаThesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2012.
Callari, Roberto. ""Produção de óleo diesel limpo a partir do gás natural: estudo de viabilidade técnico-econômica para a instalação de uma planta GTL (gas-to-liquids) no Brasil"." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/86/86131/tde-24042007-185230/.
Повний текст джерелаCALLARI. R. Production of liquid hydrocarbons employing Natural Gas: a study of the technical and economical feasibility of a GTL plant in Brazil, 2007. 84 f. Work. Program of Post-Graduation in Energy, Universidade de São Paulo, São Paulo, 2007. The development of the technology for the production of synthetic fuels from the gasification of coal started in 1919 in Germany. For a period of time the liquid hydrocarbons production increased and within the years, it was almost discontinued. The technology known as Gas-To-Liquids (GTL) refers to a chemical transformation that generates liquid products that are stable at room temperature and pressure. The transformation can be accomplished close to the natural gas production sites. In Brazil, the production and use natural gas has been growing because of the increase of the reserves of both, associated and non-associated gas. Natural gas is produced from oil explotation. The production of the liquid fractions requires processing steps. Since the offshore installations are located in distant areas, the use of the gas produced is expensive and in many cases, the gas is burned or exhausted. Due to environmental restraints the gas burning turns to be a critical issue. In order to cheapen the production of liquid products, the installation of plants to transform natural gas through the GTL technology, in associated oil and gas production installations could be the solution for the gas burning or exhaustion. The GTL plants could allow the monetization of the remote gas through the transportation of the GTL fuels produced. This work presents an evaluation of the economic costs for the implantation of a GTL plant in Brazil, in a way that allows the oil production to be kept within the environmental requirements and to generate a better use of natural gas.
Rigolin, Pascoal Henrique da Costa. "Avaliação global dos modos energéticos de transporte do gás natural inclusive como energia secundária." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/86/86131/tde-05092007-161143/.
Повний текст джерелаThe objective of this work is to make a global evaluation of some energy ways of transport of natural gas (gas-pipelines, LNG and CNG), as well as secondary energy (electricity and GTL). For the selection of a better way of transport, beyond the costs of each project, others three factors were considered: environmental impacts, social impacts and political risks. To perform this, a tool of analysis known as Evaluation of Complete Costs (ACC in portuguese) was chosen. This tool considers the four factors above mentioned as having the same importance in the evaluation process for planning that aims towards sustainability. For better visualization and understanding of the work, a case study for energy transport was made (natural gas and/or electricity) to supply the consumer markets in the region bordering Brazil and Bolivia. Basically the study of the transport was made in Bolivian territory; at the producing gas fields located in Margarita as far as the region bordering Corumbá in the Mato Grosso do Sul area, and also next to a region with great known iron ore deposits known as El Mutún. Methodologically, within the four dimensions above, some more relevant sub-criteria for the analysis were used. For all the sub-criteria considered specific ranks were taken, in accordance with the region and type of transported energy, and after this the data was fed to a software called Decision Lens, thus getting a rank of the best options to carry gas to the region. The results, most coherent way to supply gas to the region, happens to be gas-pipelines of transport for the electric and natural gas demands (consumption in MS plus Mutún) and trains with liquid derivatives of natural gas (GTL) to supply care of the demand of diesel of MS.
Langenbrunner, Nisrene A. "Understanding the Responses of a Metal and a CMCTurbine Blade during a Controlled Rub Event using a Segmented Shroud." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366191740.
Повний текст джерелаNakashima, Marcelo Reis. "O PETAR: geografia, contradições e desenvolvimento." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/8/8135/tde-06062018-102334/.
Повний текст джерелаThis research addressed the issue of the social and economic development of the Upper Ribeira State Tourist Park (PETAR), in the state of São Paulo, Brazil, from a geographic study conducted under the light of the analytical triad GTL: Geosystem, Territory and Landscape. Based on this geographical analysis, it was possible to identify how the potentialities and fragilities of the physical environment influenced the territorialization of the region where the park is today, and how the cultural landscape is built on this reality. Thus, it was possible to counter the interpretation of the data collected with the proposed Management Plan for PETAR in 2010, which has been under analysis by the State Environmental Council of the state of São Paulo since that year. The document presents internal contradictions regarding the exploitation of mineral resources. With the approval of State Law 16.260 / 2016, which grants 25 conservation units for the exploitation of the private initiative, it is necessary that there are no obscure points in the Management Plan so it is clear which resources may or may not be exploited. There are indications that, in this process, economic interests overshadowed both the objective of preserving the area and that of socioeconomic development. With this problematic in focus, we discuss how Geography and the sciences, in general, can be useful to the civilizational process by establishing objective ethical criteria, thus pointing to the causes of regional problems related to territorialization, the political contradictions of this process and how it would be possible to promote socio-environmental development in the region. One of the main problems raised is the issue of the restrictions on economic activities imposed by the environmental legislation. With tourism as the only possible source of income, the region has become highly dependent on income transfer programs which, in recent years, have proved to be crucial for the reduction of extreme poverty and the improvement of the human development indexes in the area. Since a significant relaxation of environmental restrictions would be inadvisable, and considering that the area of the park has historically been occupied by traditional populations such as quilombola communities, we have concluded that it would be reasonable to demand financial compensation from the state. This would prevent the local population from paying, alone, for the costs of an environmental conservation, that is in the best interest of society, as a whole.
Slabbert, Savia Susanna. "Evaluation of the suitabil[i]ty of Fischer-Tropsch gas-to-liquid (GTL) Primary Column Bottoms as process cooling water : analysis of microbial community dynamics, fouling, scaling and corrosion / Savia Susanna Slabbert." Thesis, North-West University, 2007. http://hdl.handle.net/10394/1309.
Повний текст джерелаThesis (M. Environmental Science (Water Science))--North-West University, Potchefstroom Campus, 2007
Rivas, Perea Manuel Eduardo. "Assessment of fuel consumption reduction strategies on a gasoline turbocharged direct injection engine with a cooled EGR system." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/68497.
Повний текст джерела[ES] El objetivo de este trabajo de investigación es estudiar la influencia de un lazo de baja presión de EGR en las prestaciones de un motor de gasolina de encendido provocado turbosobrealimentado e inyección directa, en condiciones de ensayos estacionarios y transitorios, con un proceso de optimización de la calibración original del motor para minimizar el consumo de combustible del motor. La estrategia de "cooled EGR" fue también evaluada operando en sinergia con otras estrategias usadas para reducir el consumo de combustible del motor, entre ellas: mezcla pobre, múltiples inyecciones, operación a alta temperatura del fluido refrigerante del motor y movimiento de "swirl" inducido en el cilindro. Para cumplir con los objetivos mencionados, se siguió un proceso metódico donde previamente se desarrolló una metodología global para obtener resultados de indudable calidad, basados en el uso de herramientas experimentales que cumplieran con los requerimientos de las condiciones de ensayo, y las apropiadas herramientas teóricas y procedimiento para post-procesar los ensayos realizados. En segundo lugar, se desarrolló una metodología específica para cada etapa del estudio, teniendo en cuenta los procesos de optimización o estudios paramétricos que se pudieran realizar. Como primera etapa, se presenta un estudio básico del impacto del "cooled EGR" en la combustión, prestaciones, renovación de la carga y emisiones contaminantes del motor. Seguidamente, se procedió a la optimización del centrado de la combustión con la finalidad de minimizar el consumo de combustible del motor y poder analizar el potencial del "cooled EGR" como estrategia de reducción de consumo de combustible. El estudio presentado se realizó para baja, media y alta carga del motor con dos diferentes regímenes de giro del motor. Adicionalmente, se llevó a cabo un estudio del motor operando en condiciones transitorias con "cooled EGR". Se realizaron una serie de ensayos usando el ciclo NEDC como base y se probaron diferentes estrategias sencillas de control de la apertura de la válvula de EGR para analizar la influencia del "cooled EGR" en condiciones transitorias. La segunda etapa consiste en el desarrollo de una metodología para optimizar los parámetros del diagrama de distribución (VVT) y el inicio de inyección, para cargas medias del motor, con la finalidad de maximizar el potencial de reducción de consumo de combustible de la estrategia "cooled EGR". Una vez realizada la optimización, se llevó a cabo un estudio usando la configuración óptima encontrada, operando en sinergia con otras tres estrategias usadas para reducir el consumo de combustible del motor. Estas estrategias fueron evaluadas con la finalidad de incrementar el rango de operación de la estrategia "cooled EGR" para lograr reducir aún más el consumo de combustible del motor. Adicionalmente, se llevó a cabo un estudio básico sobre la influencia de operar con mezcla pobre en la combustión, prestaciones, renovación de la carga y emisiones contaminantes del motor, como introducción al último estudio llevado a cabo sobre la posibilidad de usar la estrategia de mezcla pobre en conjunto con la estrategia de "cooled EGR", con la finalidad de analizar el potencial de controlar las emisiones contaminantes y reducir el consumo de combustible del motor al mismo tiempo.
[CAT] L'objectiu d'este treball d'investigació és estudiar la influència d'un llaç de baixa pressió d'EGR en les prestacions d'un motor de gasolina d'encesa provocat turbosobrealimentat i injecció directa, en condicions d'assajos estacionaris i transitoris, amb un procés d'optimització del calibratge original del motor per a minimitzar el consum de combustible del motor. L'estratègia de "cooled EGR" va ser també avaluada operand en sinergia amb altres estratègies usades per a reduir el consum de combustible del motor, entre elles: mescla pobra, múltiples injeccions, operació a alta temperatura del fluid refrigerant del motor i moviment de `"swirl" induït en el cilindre. Per a complir amb els objectius mencionats, es va seguir un procés metòdic on prèviament es va desenrotllar una metodologia global per a obtindre resultats d'indubtable qualitat, basats en l'ús de ferramentes experimentals que compliren amb els requeriments de les condicions d'assaig, i les apropiades ferramentes teòriques i procediment per a post- processar els assajos realitzats. En segon lloc, es va desenrotllar una metodologia específica per a cada etapa de l'estudi, tenint en compte els processos d'optimització o estudis paramètrics que es pogueren realitzar. Com a primera etapa, es presenta un estudi bàsic de l'impacte del "cooled EGR" en la combustió, prestacions, renovació de la càrrega i emissions contaminants del motor. A continuació, es va procedir a l'optimització del centrat de la combustió amb la finalitat de minimitzar el consum de combustible del motor i poder analitzar el potencial del "cooled EGR" com a estratègia de reducció de consum de combustible. L'estudi presentat es va realitzar per a baixa, mitja i alta càrrega del motor amb dos diferents règims de gir del motor. Addicionalment, es va dur a terme un estudi del motor operand en condicions transitòries amb "cooled EGR". Es van realitzar una sèrie d'assajos usant el cicle NEDC com a base i es van provar diferents estratègies senzilles de control de l'obertura de la vàlvula d'EGR per a analitzar la influència del "cooled EGR" en condicions transitòries. La segona etapa consistix en el desenrotllament d'una metodologia per a optimitzar els paràmetres del diagrama de distribució (VVT) i l'inici d'injecció, per a càrregues mitges del motor, amb la finalitat de maximitzar el potencial de reducció de consum de combustible de l'estratègia "cooled EGR". Una vegada realitzada l'optimització, es va dur a terme un estudi usant la configuració òptima trobada, operant en sinergia amb altres tres estratègies usades per a reduir el consum de combustible del motor. Estes estratègies van ser avaluades amb la finalitat d'incrementar el rang d'operació de l'estratègia "cooled EGR" per a aconseguir reduir encara més el consum de combustible del motor. Addicionalment, es va dur a terme un estudi bàsic sobre la influència d'operar amb mescla pobra en la combustió, prestacions, renovació de la càrrega i emissions contaminants del motor, com a introducció a l'últim estudi dut a terme sobre la possibilitat d'usar l'estratègia de mescla pobra en conjunt amb l'estratègia de "cooled EGR", amb la finalitat d'analitzar el potencial de controlar les emissions contaminants i reduir el consum de combustible del motor al mateix temps.
Rivas Perea, ME. (2016). Assessment of fuel consumption reduction strategies on a gasoline turbocharged direct injection engine with a cooled EGR system [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68497
TESIS
Michailidis, Antonis D. "Understanding complex CI-combustion strategies : an experimental investigation." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/10957.
Повний текст джерелаLacroix, Maxime. "Optimisation et caractérisation d’un nouveau support catalytique à base de mousses alvéolaires de β-SiC : Application à la synthèse de Fischer-Tropsch". Université Louis Pasteur (Strasbourg) (1971-2008), 2008. https://publication-theses.unistra.fr/restreint/theses_doctorat/2009/LACROIX_Maxime_2009.pdf.
Повний текст джерелаThe catalytic Fischer Tropsch Synthesis (FTS) enables the transformation of synthetic gas, i. E. Mixture of H2 and CO, into a distribution of hydrocarbons (CnH2n+2 with 1 < n < 60-100), more or less saturated and more or less oxygenated. The Gas to Liquids way, including FTS, is consequently an opportunity allowing the transformation of the flared and/or stranded gas into liquid hydrocarbons for car or plane fuelling. This could first reduce the CO2 release in the atmosphere and secondly increase the oil resources by the transformation of natural gas. The classical catalysts used in Fischer-Tropsch processes are composed of cobalt or iron supported on alumina or silica, and, although they present good performances, they are highly constricted by the high exothermicity of the reaction inducing high temperature on the catalyst surface, leading to low selectivity towards desired products (i. E. Long chained parafins). In this context, silicon carbide (β-SiC) has been proposed as replacement support to alumina and silica in order to better evacuate the heat released by the reaction and thus keeping higher selectivity even at high conversion levels. Moreover, always in order to optimize the process, the impact of the catalytic support morphology (extrudates, cellular foams) on the Fischer-Tropsch reaction has been studied. It appeared that the intrinsic properties of the cellular supports (high effective thermal conductivity, low pressure drops) could let foresee new perspectives in the fixed bed FT reaction. In this work, silicon carbide as catalyst support revealed to be far more attractive than alumina both in the form of extrudates or cellular foams. Indeed, thermal runaway have been observed on alumina whereas the use of β-SiC allowed better control of the temperature and thus better selectivity towards C5+ products. A study on the influence of the active phase charge on the catalytic performances of the catalyst supported on β-SiC foams has been performed. A simple geometric model of the foam as been developed in order to estimate the pressure drop induced by the cellular supports. A correlation with classical packed beds was showed to be able to model the pressure loss induced by a gaseous flow in the cellular material. Finally, a study on the biphasic behaviour of β-SiC foams has evidenced higher liquid hold-ups compared to classical packed beds. The influence of this property on the FT reaction has here not been made and will be the subject of a next study
Pinto, Cátia. "VineMicrobiome : Une analyse approfondie de la communauté microbienne naturelle de Vitis vinifera Vitis vinifera microbiome: from basic research to technological development Unravelling the diversity of grapevine microbiome Wine fermentation microbiome: a landscape from different Portuguese wine appellations The effects of grapevine trunk diseases (GTDs) on vine physiology." Thesis, Reims, 2017. http://www.theses.fr/2017REIMS045.
Повний текст джерелаVitis vinifera L. is a widely cultivated fruit crop, that naturally harbours a complex microbial ecosystem or plant microbiome, such as neutral, phytopathogenic or beneficial microorganisms. Among phytopathogens, those implied in Grapevine trunk diseases (GTDs) are responsible for the most destructive diseases worldwide, and currently no highly effective treatments are available. Beneficial microorganisms (BCAs) may play specific roles on plant protection against phytopathogens though, the present challenge is to understand how such microorganisms interact with plant and their biotechnological potential for development of innovation strategies. In this context, the aim of this study was firstly to unveil the microbial communities associated with grapevine along its growth cycle and, secondly, to better understand the grapevine – BCAs – GTDs interactions. For this, two potential BCAs isolated from grapevine were tested against Botryosphaeriaceae species and then deep characterized, namely for their colonisation potential, induction of defence mechanisms in grapevine, in the presence or not of D. seriata (F98.1) and their genome analysis. Results showed that grapevine microbiome was very dynamic along the growth cycle. As expected, the microbial biodiversity was higher in soils, and these microbial communities differed significantly from those of leaves. A proportion of microbial communities was shared within soils and leaves, suggesting the existence of a core microbiome. Several isolates were then obtained from grapevine which mostly belonged to Bacillus, Streptomyces and Aureobasidium genera. Some of them significantly decreased in vitro the mycelium growth of several Botryosphaeriaceae species, such as Streptomyces sp. Fito_S127B and A. pullulans Fito_F278 which were highly effective and thus selected as potential BCAs. These strains showed to produce a high range of extracellular enzymes with biocontrol value, and were able to successfully colonize grapevine: Fito_S127B was an epiphyte from rhizosphere, while Fito_F278 colonised grapevine from roots to leaves. The artificial inoculation of green stems with D. seriata F98.1 on cutting plants showed that the necrotic lesions length caused by the pathogen was significantly reduced by Fito_S127B, in contrast to Fito_F278 which was less effective. Furthermore, these BCAs activated some specific defence responses of grapevine, allowing a more rapid and solid response of plant against the pathogen. The genome analysis also showed that these BCAs strains are an important source of bioactive compounds of biocontrol value. Overall, this study brought new insights on the structure of microbial communities of grapevine and their interactions. Moreover, highlighted that grapevine is a natural source of microorganisms with a promising biocontrol against GTDs, and that they can promote plant defense responses. Thus, these findings provide not only a better understand of the grapevine- BCAs- GTDs interactions but also a strong contribution to future GTDs management strategy. Key-words: Grapevine microbiome, GTDs, D. seriata, beneficial microorganisms, Fito_S127B, Fito_F278, grapevine colonisation, plant defence mechanisms, grapevine protection
Saidane, Lamia. "Synthèses Fischer Tropsch : Optimisation des paramètres réactionnels en mode lit fixe." Strasbourg, 2009. http://www.theses.fr/2009STRA6150.
Повний текст джерелаIn the GTL process, the FTS is the step which transforms the syngas into liquid HC. In catalysis, the interest of using Co/SiC was demonstrated. This work consists in studying the influence of parameters: Treduction, promoters or the nature of the support on the activity. Modifications of the active phase particles size, its reducibility as well as its crystallinity are followed by diverse characterization techniques: XRD, TPR and SEM. The Ru effect on the Co/SiC system enhanced the Co dispersion and consequently the activity. In order to illustrate the best macroscopic shape of β−SiC (foam, pellets and powder), a comparative study on supports was also realized. A second study deals with the chemical nature of supports eg. SiC, Al2O3/SiC and Al2O3. In term of environmental protection, the base idea of this work was to enhance the catalyst life time by its regeneration and its recycling
Pinto, Cátia Carvalho. "Vine microbiome: a deep analysis of the natural microbial community of Vitis vinifera L." Doctoral thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22642.
Повний текст джерелаA vinha, Vitis vinifera L., abriga naturalmente um ecossistema microbiano complexo ou microbioma, tais como microrganismos neutros, fitopatogenos ou benéficos. Entre os fitopatogenos, aqueles implicados nas doenças do lenho da videira (GTDs) são responsáveis pelas doenças mais destrutivas, para o qual não existem tratamentos altamente eficazes. Por outro lado, os microrganismos benéficos (BCAs) podem desempenhar papéis específicos na proteção das plantas contra estes agentes. Neste sentido, o atual desafio consiste em compreender como estes BCAs interagem com a planta e qual o seu potencial biotecnológico para o desenvolvimento de novas estratégias de proteção da planta. Neste contexto, o objetivo deste estudo visou primeiramente analisar profundamente as comunidades microbianas associadas com a videira ao longo do seu ciclo de crescimento até à fermentação do vinho e, em seguida, compreender as interações entre vinha-BCAs-GTDs. Para isso, dois potenciais BCAs isolados da videira foram testados contra diferentes espécies de Botryosphaeriaceae e, em seguida, caracterizados relativamente ao seu potencial de colonização, de indução dos mecanismos de defesa da planta, na presença ou não do fitopatogeno (D. seriata F98.1), e análise do respetivo genoma. Os resultados demonstraram que o microbioma da videira é altamente dinâmico ao longo do ciclo de crescimento da planta. Como esperado, a biodiversidade microbiana é maior nos solos, e estas comunidades diferem significativamente daquelas presentes nas folhas e mostos vínicos. Contudo, alguns destes microrganismos são partilhados, o que sugere a existência de um microbioma comum. Diferentes isolados foram obtidos, pertencendo na sua maioria ao género Bacillus, Streptomyces e Aureobasidium. A videira é naturalmente colonizada por microrganismos com potencial antagonista de várias espécies de Botryosphaeriaceae. Entre estes, destacam-se os isolados Streptomyces sp. Fito_S127B e A. pullulans Fito_F278, que foram selecionados como potenciais BCAs. Estes microrganismos produzem diferentes enzimas extracelulares importantes para as atividades de controlo biológico e são capazes de colonizar com sucesso a videira: Fito_S127B coloniza a rizosfera, enquanto que Fito_F278 coloniza desde as raízes até às folhas. A inoculação artificial da videira com D. seriata F98.1 mostrou que o comprimento das lesões necróticas causadas pelo fitopatogeno são significativamente reduzidas na presença de Fito_S127B. Em contrapartida, a espécie Fito_F278 foi menos eficaz. Estes BCAs ativaram algumas respostas de defesa específicas da videira, o que permitiu uma resposta mais rápida e sólida da planta contra o agente fitopatogénico. A análise do genoma destes microrganismos permitiu averiguar diferentes genes que codificam compostos bioativos altamente importantes para o controlo biológico. De uma forma geral, este estudo abrange novos conhecimentos relativos à estrutura das comunidades microbianas associadas à videira e às suas interações. Para além disso, destaca que a videira ostenta naturalmente microrganismos com um controlo biológico promissor e que estes podem promover respostas de defesa importantes na planta. Neste sentido, estes resultados permitem não só uma melhor compreensão das interações da videira-BCAs-GTDs, mas também representam um forte contributo e avanço para o desenvolvimento de novas estratégias da gestão da vinha, tais como as doenças do lenho.
Vitis vinifera L. is a widely cultivated fruit crop, that naturally harbours a complex microbial ecosystem or plant microbiome, such as neutral, phytopathogenic or beneficial microorganisms. Among phytopathogens, those implied in Grapevine Trunk Diseases (GTDs) are responsible for the most destructive diseases worldwide, and currently no highly effective treatments are available. Beneficial microorganisms (BCAs) may play specific roles on plant protection against phytopathogens though, the present challenge is to understand how such BCAs interact with plant and their biotechnological potential for development of innovation strategies. In this context, the aim of this study was firstly to unveil the microbial communities associated with grapevine along its growth cycle until wine fermentation and, secondly, to better understand the grapevine – BCAs – GTDs interactions. Two potential BCAs isolated from grapevine were tested against Botryosphaeriaceae species and then deep characterized, namely for their colonisation potential, induction of defence mechanisms in grapevine, in the presence or not of D. seriata F98.1, and their genome analysis. Results showed that grapevine microbiome was very dynamic along the growth cycle. As expected, the microbial biodiversity was higher in soils, and these microbial communities differed significantly from those of leaves and wine musts. A proportion of microbial communities was shared within these structures, suggesting the existence of a core microbiome. Several isolates were then obtained from grapevine which mostly belonged to Bacillus, Streptomyces and Aureobasidium genera. Some of them significantly decreased in vitro the mycelium growth of several Botryosphaeriaceae species, such as Streptomyces sp. Fito_S127B and A. pullulans Fito_F278 which were highly effective and thus selected as potential BCAs. These strains showed to produce a high range of extracellular enzymes with biocontrol value, and were able to successfully colonize grapevine: Fito_S127B was an epiphyte from rhizosphere, while Fito_F278 colonised grapevine from roots to leaves. The artificial inoculation of green stems with D. seriata F98.1 on cutting plants showed that the necrotic lesions length caused by the pathogen was significantly reduced by Fito_S127B, in contrast to Fito_F278, which was less effective. Furthermore, these BCAs activated some specific defence responses of grapevine, allowing a more rapid and solid response of plant against the pathogen. The genome analysis also showed that these BCAs strains are an important source of bioactive compounds of biocontrol value. Overall, this study brought new insights on the structure of microbial communities of grapevine and their interactions. Moreover, highlighted that grapevine is a natural source of microorganisms with a promising biocontrol against GTDs, and that they can promote plant defence responses. Thus, these findings provide not only a better understand of the grapevine- BCAs- GTDs interactions but also a strong contribution to future GTDs management strategy.
Comblet, Fabrice. "Détection, localisation et identification de cibles radar par imagerie électromagnétique bistatique." Phd thesis, Université de Bretagne occidentale - Brest, 2005. http://tel.archives-ouvertes.fr/tel-00011931.
Повний текст джерелаBricteux, Caroline. "Régulation de l'Internet par les noms de domaine. Le régime juridique et institutionnel de l'ICANN." Doctoral thesis, Universite Libre de Bruxelles, 2019. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/284381.
Повний текст джерелаDoctorat en Sciences juridiques
info:eu-repo/semantics/nonPublished
HUANG, GI-FANG, and 黃啟芳. "GTD analysis of electromagnetic scattering by convex surface." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/12728816393041113098.
Повний текст джерелаHamad, Natalie. "Safety and Techno-Economic Analysis of Solvent Selection for Supercritical Fischer-Tropsch Synthesis Reactors." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10370.
Повний текст джерелаBlack, Brodie Gene 1986. "Monetizing stranded gas : economic valuation of GTL and LNG projects." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-05-1342.
Повний текст джерелаtext
Chou, Chun-Wei, and 周俊瑋. "A systolic array based GTD processor with a parallel algorithm." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/643kx6.
Повний текст джерела國立交通大學
電子工程學系 電子研究所
103
Generalized triangular decomposition (GTD) has been found to be useful in the field of signal processing, but the feasibility of the related hardware has not yet been established. This paper presents (for the first time) a GTD processor architecture with a parallel algorithm. The proposed parallel GTD algorithm achieves an increase in speed of up to 1.66 times, compared to the speed of its conventional sequential counterpart for an 8x8 matrix. For hardware implementation, the proposed reconfigurable architecture is capable of computing singular value decomposition (SVD), geometric mean decomposition (GMD), and GTD for matrix sizes from 1x1 to 8x8. The proposed GTD processor is composed of 16 processing cores in a heterogeneous systolic array. Computations are distributed over area-efficient coordinate rotation digital computers (CORDICs) to achieve a high throughput. To establish the validity of the concept, a GTD processor was designed and implemented. The latency constraint of 16 us specified in the 802.11ac standard is adopted for the hardware realization. The proposed design achieves a maximum throughput of 83.3k matrix/sec for an 8x8 matrix at 112.4 MHz. The estimated power and core area are 172.7 mW and 1.96 mm^2, respectively, based on standard 90 nm CMOS technology.