Orientador: Vitor Baranauskas / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-05T07:21:22Z (GMT). No. of bitstreams: 1 Iannini_RobertoFonseca_M.pdf: 1222857 bytes, checksum: 41c44a25bef2f1656de6659dff1c5734 (MD5) Previous issue date: 2005 / Resumo: O progresso da pesquisa científica depende da qualidade e da disponibilidade de instrumentos confiáveis e de alta precisão, necessários para a exploração quantitativa de novos fenômenos, possibilitando a construção de modelos mais avançados e mais sofisticados. Um dos fenômenos que tem despertado grande interesse é a emissão de elétrons da superfície de catodos frios para o vácuo, sob a ação de campos elétricos externos. Para o estudo deste fenômeno, é necessária a medida de pequenas correntes em amostras que estão sob tensões elétricas relativamente altas. Nesta tese contribuímos com o projeto e construção de um medidor de corrente capaz de operar de maneira integrada à câmara de vácuo onde são analisadas as propriedades de emissão de nanotubos ou de materiais nanoestruturados. Foram desenvolvidos integralmente o hardware, firmware e software, com vistas à integração futura com outros instrumentos de controle e análise / Abstract: The progress of scientific research depends of the quality and availability of reliable and high precision instruments, which are necessary for measurement of new phenomena, making possible the construction of advanced and sophisticated models. One phenomenon that has being studied is the field emission of electrons from cold cathodes in vacuum, under external electrical field influence. In order to perform this study, it is necessary to measure small electrical currents with the surface sample under high voltage. In this thesis, we have contributed with the project and construction of a electric current meter able to operate in a vacuum chamber environment where the field emission properties of sample materials (nanotubes or nanostructures) are analyzed. Both hardware, firmware and software were developed looking forward to future integration of the measurement and control equipments / Mestrado / Instrumentação e Controle / Mestre em Engenharia Elétrica

Orientador: Luiz Carlos Pereira da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-26T06:55:21Z (GMT). No. of bitstreams: 1 Cardoso_FrednerLeandro_M.pdf: 3528656 bytes, checksum: b6121b44e4520a59d20be1f12ed3f377 (MD5) Previous issue date: 2014 / Resumo: Esta dissertação apresenta um estudo referente à instalação de reatores limitadores das correntes de curto circuito em redes de subtransmissão. O objetivo é adiar ou evitar a substituição de grandes quantidades de disjuntores e demais equipamentos por motivo de superação de capacidade interruptiva. O sistema em análise consiste da rede da CPFL de 138 kV, responsável pelo suprimento de energia elétrica à região metropolitana de Campinas, no interior do estado de São Paulo. Esta região é uma das mais dinâmicas no cenário econômico brasileiro e representa 1,8% do PIB (Produto Interno Bruto) nacional e 11,45% do PIB paulista, ou seja, cerca de 91,8 bilhões de reais. Além de possuir uma forte economia, a região também apresenta uma infraestrutura que proporciona o desenvolvimento de toda a área metropolitana. O cenário acima resulta em uma rede elétrica em expansão contínua, levando à elevação gradativa dos níveis de curto circuito. Com a previsão de superação da capacidade interruptiva em diversos módulos de manobra, as empresas concessionárias que atuam nessa região precisaram elaborar esquemas provisórios de operação de suas instalações de forma radializada, através da abertura de linhas e barramentos. Este trabalho analisa a viabilidade da solução deste problema através da instalação de dispositivos limitadores de curto circuito em determinados locais do sistema, especificamente reatores com núcleo de ar. Os resultados apresentados servirão como referência para tomada de decisão quanto a proceder ou não com as substituições originalmente planejadas. Um estudo sobre os efeitos colaterais resultados da instalação dos reatores também é apresentado, de forma a garantir que a solução sugerida não resulte em transgressão de outros critérios técnicos, tais como violação do perfil de tensão e carregamento em regime permanente e dos limites de tensão de restabelecimento transitória / Abstract: This master thesis presents a study on the application of limiting reactors for reducing the short circuit level of sub-transmission networks. The objective is to postpone or avoid the replacement of large amount of circuit breakers and other equipment due to the overcoming of their interruptive capacity. The system under consideration consists of the 138 kV CPFL network, responsible for supplying electricity to the metropolitan region of Campinas, in the state of São Paulo. This region presents a very dynamic economic scenario in Brazil, and represents 1,8% of national GDP about 91,8 billion Reais (Gross Domestic Product) and 11,45% of GDP of the São Paulo State. Besides having a strong economy, the region also maintains an infrastructure that provides the development of the entire metropolitan area. The above scenario results in an electric grid on continuous expansion, leading to progressive increase of the short circuit level on several buses of the network. Following the projection of interruptive capacity overcoming of several maneuver elements, the distribution utilities in this region were requested to elaborate operation schemes for their sub-transmission networks in order to accommodate the new situation. Such schemes leaded to temporary radial operation by opening sub-transmission lines and bus bars. This research work evaluate the viability of solving this problem by installing limiting devices for the short circuit levels, specifically air core reactors, in pre-determined sites of the system. The obtained results are useful as a reference for the decision making as to proceed or not with the originally planned replacements. A study on the side effects resulting from the installation of the reactors is also presented, in such a way to guarantee that the suggested solution does not result in violations of other technical criteria, such as steady state voltage end load violations or transient voltage recovery violations / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Orientador: José Antenor Pomílio / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T11:27:09Z (GMT). No. of bitstreams: 1 Rodrigues_DiegoTardivo_M.pdf: 3096616 bytes, checksum: 2d3b90e8f78bbfc91209e0e523c0f21b (MD5) Previous issue date: 2012 / Resumo: O trabalho tem como aplicação a geração de ozônio, que se dá em uma célula ozonizadora a partir de descargas eletrostáticas resultantes da aplicação de alta tensão por um transformador. Uma ressonância série essencialmente determinada pela indutância de dispersão e a capacitância equivalente do sistema surge, para este caso, em frequências na ordem de kHz. A operação do inversor de alimentação com uma frequência de chaveamento pouco maior do que a frequência de ressonância série tem como vantagens a comutação suave das chaves do inversor, um alto ganho de tensão e a possibilidade da construção de transformadores menores comparado à operação em 60 Hz. Visando o aumento da potência total do sistema e, consequentemente, aumento na capacidade de geração de ozônio, como alternativa para tal é feita a conexão em paralelo de diversos conjuntos formados por transformadora e respectiva célula, com potência da ordem de centenas de Watts, sendo estes alimentados por um único inversor. No entanto, a dispersão de parâmetros dos transformadores e células, leva a diferentes valores de potência por conjunto, estando alguns com potência acima da nominal e outros abaixo. A fim de se obter uma distribuição igual de potência entre as cargas, é apresentada uma estratégia para a equalização de potência em uma associação em paralelo de circuitos ressonantes com dispersão de parâmetros. O ajuste da sintonia é feito por meio de compensação série utilizando a técnica de síntese direta de reatâncias. Um modelo baseado no método médio generalizado foi obtido para que os parâmetros do controlador utilizado na equalização de potência fossem determinados. O uso de transformadores geralmente traz a necessidade de se precaver a um processo de saturação, todavia, é apresentada uma estratégia de controle capaz de impedir a saturação, por meio da síntese de capacitância variável série. Resultados de simulação e experimentais mostram o comportamento dos circuitos e das estratégias de controle propostas / Abstract: The work is applied to ozone generator, which occurs in an ozone generator cell through electrostatic discharges produced by high voltage transformer. A series resonance essentially determined by the leakage inductance and equivalent capacitance of the system arises in this case, at frequencies on the order of kHz. The operation of the inverter which feeds the load with switching frequency above the series resonance frequency has the advantages of soft switching at the inverter switches, a high voltage gain and the possibility of construct smaller transformers compared to operation at 60 Hz. Seeking to increase the total power system and, consequently, the capacity of ozone generation as an alternative is placed in parallel several loads formed by the transformer and respective cell, with a power of hundreds of Watts, fed by a single inverter. However, due to electrical parameters dispersion, there is not an equal distribution of power among the loads, with some being above the nominal power and other below. Order to obtain an equal distribution of power, a strategy is presented for balancing the power among paralleled loads. The balance is achieved through series compensation using the Direct Reactance Synthesis. A model based on the generalized average method is obtained for the controller parameters used in the equalization of power were found. Transformers usually need attention to avoid saturation; therefore, this work presents a control strategy to prevent the saturation, by synthesis of series variable capacitance. Simulation and experimental results show the behavior of circuits and proposed control strategies / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Orientador: Vitor Baranauskas / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T02:41:28Z (GMT). No. of bitstreams: 1 Iannini_RobertoFonseca_D.pdf: 3201679 bytes, checksum: cd82a05d0dedaa3ecc2f0ca77550b58d (MD5) Previous issue date: 2012 / Resumo: Foi projetado e desenvolvido um sistema de aquisição de dados e controle para viabilizar, de forma automatizada, a caracterização de emissividade eletrônica em catodos frios, por meio da utilização da câmara de ultra alto vácuo do Departamento de Semicondutores, Instrumentação e Fotônica - DSIF, da Faculdade de Engenharia Elétrica e Computação - FEEC/Unicamp. A instrumentação desenvolvida teve como motivação: i) aumentar a confiabilidade dos procedimentos de leitura da corrente de emissão de campo em amostras de materiais nanoestruturados produzidos no laboratório; ii) garantir a reprodutibilidade dos ensaios; iii) preservar a integridade das amostras; iv) eliminar fontes de erro existentes no processo de aquisição dos dados; v) prover uma família de curvas de forma automatizada, para cada posicionamento da amostra analisada. Os principais desafios encontrados durante os trabalhos relacionaram-se com a definição da topologia do circuito de entrada, da forma da isolação galvânica, interferências e tratamento dos dados adquiridos. Após a entrada em operação da instrumentação, foram também realizados ensaios para fins de validação da instrumentação desenvolvida e dos procedimentos adotados para sua operação / Abstract: A data acquisition and control system was designed and built in order to promote, in an automated fashion, the characterization of cold cathodes in the ultra high vacuum chamber of the DSIF, at the FEEC/Unicamp. The designed instrumentation was supposed to meet the following requirements: i) Enhance the accuracy of the field emission reading procedures for the nanostructured samples made in the same laboratory; ii) Ensure better repeatability of the tests; iii) Preserve the physical integrity of the samples; iv) Eliminate sources of error in the data acquisition process; v) Allow for automated establishment of a family of curves for each point of the sample material. The main challenges during this work were related to the circuit architecture, its input topology, galvanic isolation, interferences and data management. As the instrumentation started working, we have performed a series of tests for validation purposes, including the adopted operational proceedings / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica

Abstract In high voltage substations there is an increasing demand for computerized equipment, and automation of operation and supervision. The future primary equipment will provide the possibility to collect more information and to provide better control for improved effectiveness. Since ABB has got a large customer target, each product must be custom made to fulfil the customers (often from different countries) demands. Later these products will be configured by engineers who may not be familiar with the tools used at ABB. This is a very expensive and time consuming. To solve the problem, ABB was looking for a low cost, easy managed and more advanced replacement. This report includes an investigation for a function block configuration tool based on Microsoft Visio. The tool is connected to a general database using ODBC for the latest ABB Substation Automation SW platform for protection in power transmission equipment. The thesis report mainly contains a description of the functions and features that are requested. Then methods used to build the prototype is explained and at the end the result is presented. At the same time the possibilities and problems that will arise from using ODBC based interface for control and monitoring of real-time systems were investigated.

Ever since the discovery of DNA, there has been many pathologies identified effecting mankind. With the development in technology, there are many methods to alleviate these pathologies. One such is gene therapy or gene delivery. It is a process of introducing some foreign material into the body to correct the effected cells. In principle, it is a modern method to cure cells or a method to transfer nucleic acid into a cell to treat specific cells in the body. The process of delivering a genetic material is carried out using vectors, namely, viral vectors and non-viral vectors. In viral vectors, viruses are modified to make it efficient for delivery into the host cells. This method has high transduction rate as compared to non-viral method. Non-viral methods include chemical and physical transfection methods, which are used to deliver the gene of interest into the host cell unlike viral methods. In this study, a physical method using high voltage is used to deliver a genetic material into cells. High voltages are used to permeabilize the cell to allow the foreign material into it and to express it in the host cell. This process is termed as Electroporation. In specific, in this research, studying a process of charging a region that mimics skin and trying to localize the presence of electric fields on the surface where the strongest uptake of genetic material is found. In other words, region where the gene expression is strongest at a specific region if performed on skin is studied by localizing electric fields on the surfaces. My work is to characterize and develop where this effect takes place on the surface based on both positive and negative electric fields. A physical method is useful as it is a non-toxic way to get a DNA/protein into someone’s body without making them sick, unless if not using a virus to deliver. This is all done using high voltages up to 8kV and the electric fields produced due to high voltages are localized, visualized and characterized with both positive and negative polarities of voltages. In this study, experiments with high voltages are performed and the spread of charges at specific regions are collected using a needle. This needle goes into corona, which may be called as a secondary corona. It might be called a secondary corona because the flat conductor is being charged by a metal finger but not directly by the power supply. Here, the conductor is charged by a metal finger of high input voltage, which ionizes the air molecules above the flat conductor to form a conductive region. As the input voltage is increased further, electrons escape from the needle to air or from molecules to needle forming negative or positive ions respectively. The outputs at needle were measured on the oscilloscope. In this study, repeated sets of experiments are carried out to collect consistent and reliable data. Visualizing/characterizing these fields are important as maximum delivery takes place at high voltage regions, with a condition that permeability of the cells should be known for proper transfection to occur, otherwise cells would die due to high voltages or no transfection takes place due to poor permeability of cell membrane.

No description available.

No description available.

O presente trabalho teve como objetivo estudar diferentes tecnologias na extração de óleo da semente de gergelim e de compostos fenólicos e proteínas da torta de gergelim. Este estudo está dividido em quatro partes. O objetivo da primeira parte do trabalho foi extrair compostos fenólicos de diferentes tortas de nozes e sementes nas mesmas condições e comparar o teor de tais compostos e a atividade antioxidante dos extratos. Nessa fase, foram utilizadas nos experimentos tortas das sementes de girassol, linhaça e gergelim, e das nozes amêndoa, pecã, macadâmia e avelã. O extrato da torta de noz pecã apresentou o maior teor de todos os compostos fenólicos analisados, seguido pelo extrato da torta de semente de girassol e de avelã. Essas amostras também apresentaram as maiores atividades antioxidantes. As etapas seguintes do trabalho focaram-se no gergelim. A segunda parte do trabalho teve como objetivo a otimização da extração, pela metodologia convencional, de fenólicos totais e lignanas da torta de gergelim. Inicialmente, um modelo polinomial de segunda ordem foi utilizado para predição dos resultados, mediante a variação da temperatura, concentração de etanol e razão, sólido/solvente. As variáveis de resposta foram as concentrações de fenólicos totais, de sesamina e de sesaminol triglicosídeo e a atividade antioxidante dos extratos obtidos. Entre os compostos analisados, o sesaminol triglicosídeo está presente em maior quantidade na torta de gergelim. A razão sólido/solvente e a concentração de etanol foram os fatores que mais afetaram a extração, enquanto a temperatura demonstrou uma influência reduzida. Na terceira etapa, o escopo da pesquisa foi a avaliação de metodologias alternativas na extração desses mesmos compostos e, também, de proteínas. As tecnologias usadas foram as de campo elétrico pulsado (CEP) e de descargas elétricas de alta tensão (DEAT). A análise da aplicação de CEP e de DEAT foi realizada usando essas tecnologias como pré-tratamentos ao processo de extração com solvente. Os resultados demonstraram que as técnicas foram eficazes e aumentaram os rendimentos do processo para fenólicos totais, lignanas e proteínas da torta. O uso de diferentes porcentagens de etanol também se mostrou significativo nessa etapa, entretanto, esse efeito foi reduzido quando utilizadas as tecnologias elétricas. Da mesma forma, o efeito da temperatura na etapa difusiva foi menor quando os pré-tratamento foram utilizados. Os comportamentos observados sugerem que a aplicação de CEP e DEAT aumenta a eficiência da extração de compostos de interesse. Por fim, na quarta parte do trabalho, objetivou-se melhorar a eficiência do processo de extração do óleo de gergelim aplicando as tecnologias previamente citadas. Esses experimentos demonstraram um efeito significativo dos tratamentos de CEP e DEAT e um aumento na quantidade de óleo extraído com o aumento da energia aplicada às sementes. O uso de DEAT gerou um aumento maior na quantidade de óleo extraído, se comparado à tecnologia de CEP. / The goal of the present work was to study different technologies in the extraction of oil from sesame seed and phenolic compounds and proteins from sesame cake. This study is divided in four parts. The first part aimed to extract water-soluble compounds from different seed and nut cakes under the same conditions and compare the phenolic content and antioxidant activity of the extracts. For the first portion of the study, seed cakes of sunflower, pumpkin, flaxseed and defatted sesame, and nut cakes of almond, pecan, macadamia and hazelnut were used in the experiments. The extract from pecan nut cake presented the highest amounts of all compounds analyzed, followed by sunflower seed and hazelnut cake extracts. These samples also had the highest antioxidant activities. The following steps of the work focused on sesame only. The second part of the work aimed to optimize the extraction of total phenolics and lignans from sesame seed cake. Initially, a second-order polynomial model was set up to predict the responses in different temperatures, solid/solvent ratios and ethanol concentrations. The response variables were the concentrations of total phenolics, sesamin, sesaminol triglucoside and antioxidant activity of the extracts. Among the analyzed compounds, ST is presented in the highest quantity in sesame cake. Solid to liquid ratio and ethanol concentration where the most important factors affecting extraction, whereas temperature showed reduced influence. In the third part of this work, the aim was to evaluate alternative methodologies in the extraction of phenolics and proteins. The technologies used were pulsed electric fields (PEF) and high voltage electric discharges (HVED). These methods were used as pre-treatments, prior to diffusion. Result show that PEF and HVED were efficient and increased the extraction yield for phenolic compounds, lignans and proteins from the cake. The use of different percentages of ethanol was also significant in this stage; however, the effect of this parameter was reduced when the electrical treatments were used. In the same way, temperature also showed a smaller influence on the results when the pre-treatments were used. The observed behaviors suggest that the use of PEF and HVED increases extraction efficiency. Finally, the goal of the last part of the work was to improve oil expression from sesame seeds, using the aforementioned technologies. These experiments show a significant effect of both PEF and HVED. It was observed an increase of the amount of oil extracted with the energy input applied to the seeds. When compared both technologies, HVED showed a more expressive effect then PEF.

Capillary electrophoresis laser-induced fluorescence (CE-LIF) is widely used to detect both the presence and concentration of fluorescently labeled biomolecules. In CE-LIF, a plug of sample fluid is electrophoretically driven down a microchannel using a high voltage applied between the opposite ends of the microchannel. Molecules of different sizes and charge states travel at different velocities down the channel. Laser light with a wavelength in the excitation band of the fluorophores is focused near the end of the channel. As each species of molecule passes through the laser spot, the fluorophores emit a fluorescence signal which is measured with an optical detector. Commercial CE-LIF systems are available as a complete, expensive package. Custom CE-LIF systems are a collection of commercially available components that meet the specific needs of the end user. Using the custom system in Dr. Woolley's lab as the standard, we hypothesized that 3D printed parts in conjunction with low-cost components could be used to significantly reduce costs and simplify the system, which in turn would make such systems more widely available with a lower barrier to entry. Testing this hypothesis began with five semesters of small teams of senior undergraduate students trying to design and assemble a low-cost CE-LIF system as part of their mandatory one-semester senior project. I was one of the seniors who worked on the system. Although none of the senior project teams were successful, a partially functioning system was ultimately produced. I reference this system as the starting point system throughout this thesis, which is focused on identifying and solving the system's obstacles in order to reach a working state. I re-designed and re-built each sub-system of the starting point system as needed if within the available budget to create a system that was functional. Budgetary constraints were included in evaluating potential improvements. The end goal was to compare the improved system's performance with that of an expensive conventional system (hereinafter referred to as the standard system) available in Dr. Adam Woolley's laboratory on the Brigham Young University campus. The ultimate conclusion of my masters' thesis work is that a low-cost CE-LIF system based on 3D printed and low-cost components results in a system that does not offer repeatable performance. In the course of my work, many lessons were learned as to what would reduce overall system costs while maintaining a user-friendly experience. My analysis is given on a subsystem basis to explain what limited the ability of the system to run consistently or what caused it to fail altogether. Details and methodology of my contributions including circuits designed, code written, components used, and 3D models printed in order to test the hypothesis are documented. Attribution of the work prior to mine is laid out when each subsystem is broken down in detail for the failure modes that prevented consistent operation. Future work is suggested to correct the problems encountered and provide a path forward to implement a next-generation system that can be achieved at a lower cost compared to a conventional system, and yet which does not suffer from the performance problems associated with the version explored in this thesis in which maximum cost reduction was aggressively pursued.