Orientador: Jose de Assis Fonseca Faria / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-24T02:05:10Z (GMT). No. of bitstreams: 1 Anjos_CarlosAlbertoRodrigues_D.pdf: 5958526 bytes, checksum: 425a607d4c8a53c599e67cc5709a6af3 (MD5) Previous issue date: 1998 / Resumo: A secagem da resina é uma das etapas mais importantes no processamento de polietileno tereftalato (PET) destinado á fabricação de embalagens, peças de engenharia e diversas outras aplicações. É o estágio responsável pela qualidade final da resina antes de ser transformada pelos processos de injeção, injeção-estiramento-sopro, injeçâo-sopro ou extrusâo-sopro que requer elevado consumo de energia e longo tempo de duração, representando gastos excessivos no processamento antes da transformação da resina em embalagens. 0 superaquecimento superficial da resina de PET pode provocar aumento do grau de cristalização, redução da viscosidade intrínseca e alteração da cor inicial, consequentemente, redução de propriedades importantes nas embalagens finais. Em ambientes de elevada umidade relativa a umidade da resina de PET pode chegar a 0,6 % (p/p), porém o máximo de desempenho em processos, principalmente de injeção, requer umidades de 0,05 e 0,005% (p/p) ou menos, dependendo da aplicação. No presente estudo, procurou-se desenvolver a aplicação da energia de microondas na secagem da resina de PET, a partir de configurações de diferentes processos, com o objetivo de verificar o comportamento da resina de PET sob campo de microondas, comparado com o processo convencional a ar aquecido, e através de urn forno de laboratório com microprocessador a fim de estabelecer parâmetros de tratamento tais como temperatura, tempo e potência de microondas. Trabalhou-se com potências de 50 a 300 W e tempos de 0,6 a 2,6 horas com o objetivo de reduzir a umidade e manter inalteradas características importantes ao desempenho da resina durante os processos de transformação. Devido o PET ser um polímero de baixa permissividade dielétrica e de seu elevado grau de cristalização, atingiram-se valores de umidade de até 0,04% (p/p), acima de 0,005 (p/p), considerado valor ótimo para a transformação em embalagens, porém próximos dos valores para a utilização em outros segmentos, como por exemplo o de peças de engenharia. Verificou-se, ainda, que a aplicação da energia de microondas não afetou as características de viscosidade intrínseca e cor. Entretanto, os níveis de acetaldeído diminuíram em algumas amostras, o que é um resultado considerado satisfatório. / Abstract: The drying of the resin is one of the most important stages in the processing of polyethylene terephthafate (PET) for use in the manufacture of packaging materials, engineering parts and other applications. It is the stage responsible for the final quality of the resin before its transformation by processes of injection, injection-stretching-blowing or extrusion-blowing, and it consumes a lot of energy and long periods of time, representing excessive expenditure in the processing before the transformation step into packages. Superheating of the surface of the PET resin can result in an increase in the degree of crystallization, reduction in the intrinsic viscosity and change in the initial colour, with a consequent reduction in the important properties of the final packaging materials. In atmospheres of high relative humidity, the moisture content of the PET resin can rise to 0,6% (w/w), where as maximum performance during processing, especially in those involving injection, requires moisture contents of 0,05% (w/w) or less, depending on the application. This study aimed at development the application of microwave energy in the drying of PET resin according to the configurations for different processes, with the objective of determining the behaviour of the PET resin in a microwave field as compared to the conventional hot air process and using a laboratory microwave oven equipped with a microprocessor for controlling time, temperature and power Potentials of 50 to 300 W and times of 0,6 to 2,6 hours were used with the objective of reducing the moisture content while retaining the important characteristics related to the performance of the resin during the transformation processes. Since PET is a polymer of low dielectric permissivity and high degree of crystallization, moisture values of up to 0,04% (w/w) were obtained, greater than the value of 0,005% (w/w) considered optimum for transformation into packaging materials, but close to the values used in other sectors, such as for engineering parts. It was also shown that the application of microwave energy did not affect the intrinsic viscosity and colours and that the acetaldehyde levels of some samples were reduced, which is considered to be a satisfactory result. / Doutorado / Mestre em Tecnologia de Alimentos

Orientadores: João Marcos Travassos Romano, Rui Fragassi Souza / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica / Made available in DSpace on 2018-07-18T07:07:30Z (GMT). No. of bitstreams: 1 Mota_JoaoCesarMoura_D.pdf: 12582438 bytes, checksum: 89bfd221ce43b511fc5c212966d78701 (MD5) Previous issue date: 1992 / Resumo: A equalização num sistema de transmissão rádio-digital por microondas é enfocada sob o ponto de vista estacionário e transiente. A teoria clássica da equalização transversal discreta é reapresentada e complementada nos aspectos de relacionamento entre os critérios clássicos da minimização do erro quadrático médio (MEQM) e da forçagem a zero (FZ), e também da obtenção do algoritmo de ajuste dos coeficientes complexos do equalizador pelo critério da FZ. As limitações dos algoritmos estocásticos clássicos no modo de decisão dirigida, quando em operação nos períodos de inicializações dos sistemas rádio-digitais com os diagramas de olhos fechados (forte distorção), são confirmadas por simulações computacionais, indicando a necessidade da atuação de algoritmos mais robustos no modo autodidata. A verificação da característica de fase não- mínima, para a versão amostrada da resposta ao impulso do canal de microondas, restringe a escolha destes algoritmos. Isto se deve à impossibilidade de fazer uso das estatísticas de ordem 2 de sinais disponíveis no receptor, para fins de equalizar a amplitude e a fase de canais de fase não-mínima. Alguns algoritmos cegos existentes na literatura têm seus desempenhos comparados em sistemas rádio-digitais, através principalmente das suas robustez, velocidades de convergência e consistências. É verificado que, dos algoritmos testados, o algoritmo de Godard é aquele que apresenta o melhor compromisso entre os aspectos analisados, confirmando alguns resultados experimentais. Finalmente, é verificada a obtenção da equalização através da identificação exclusiva entre os momentos de ordem 4 dos sinais de entrada do sistema e os momentos de ordem 4 dos sinais de saída do equalizador. Esta verificação leva a um método não-linear para a equalização. Fazendo uso exclusivo da identificação de momentos cruzados de ordem 4 entre os sinais na entrada e saída do canal, é possível obter um método linear para a equalização. Este método pode permitir a atuação, no modo autodidata, de algoritmos cegos baseados em estimação dos momentos de ordem 4. Os resultados analíticos obtidos são comparáveis àqueles dos critérios da MEQM e da FZ / Abstract: Equalization in microwave digital-radio transmission systems is dealt with under a transient and steady-state point of view. The c1assical theory of digital transversal equalization is revisited and complemented concerning the c1assical aspects of mean square error minimization (MSEM) and zero forcing (ZF), and also in the proposal of an algorithm for the adjustement of the complex coeffjcients of an equalizer by the ZF criterium. Classical stochastic algorithms limitations operating in the directed-decision mode for initializations periods in digital-radio systems (under c1osed eyes diagram, corresponding to strong distortion) are confirmed in computer simulations, suggesting the need of using robust algorithms, specially in the autodictate mode. The non-minimum phase characteristics for the sampled impulse reponse version of the microwave channel, restricts the choice of such algorithms. This happens due to the impossible use of second-order statistics processing in the available receiver signals, for the proper equalization of amplitude and phase in a non-minimum phase channel. A few blind algorithms available in the literature are compared for digital-radio systems, concerning their robustness, convergence velocities and consistencies behavior. It is confirmed that, among ali tested algorithms, the Godard algorithm is the one that shows the best compromise concerning the analised aspects, confirming some experimental results. Finnaly, an equalization linear method for the complex modulation is proposed based on the matching between the fourth-order moments of the system input signals and the fourth-order moments of the channel ouput signals. Perhaps, this method allows the action, in the autodidacte mode, of blind algorithms based in the estimation of fourth-order moments. The analytical results obtained are comparable with those of the MSEM and ZF criteria / Doutorado / Mestre em Engenharia Elétrica

Orientador: Rui Fragassi Souza / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica / Made available in DSpace on 2018-07-18T14:24:01Z (GMT). No. of bitstreams: 1 Remy_MarcoAndre_M.pdf: 14072366 bytes, checksum: 1c5530f366b0aedeb5b9d94dc15efa27 (MD5) Previous issue date: 1993 / Resumo: Neste trabalho é apresentado o sistema de microondas desenvolvido para o acelerador linear de elétrons do Laboratório Nacional de Luz Síncrotron e que será utilizado como máquina pré-injetora de elétrons no acelerador circular de elétrons (Síncrotron). O Sistema opera na freqüência de 2,856 GHz em três níveis de potência, a saber:Subsistema de Baixa Potência(»100 mW), Subsistema de Média Potência (» 1 kW pulsado)e Subsistema de Alta Potência (»25 MW pulsado). São apresentados os fundamentos teóricos, desenhos mecânicos e os resultados experimentais de diversos componentes de microondas desenvolvidos para o Sistema e os problemas específicos da transmissão de potências, a nível de megawatts, em guias de onda. Também, são apresentados os circuitos eletrônicos de detecção de amplitude de sinal, fase relativa e de segurança desenvolvidos para o Sistema.O acelerador linear de elétrons está em operação há três anos / Abstract: This work presents the microwave system developed for the electron linear accelerator of Laboratório Nacional de Luz Síncroton and that will be used as an electron pre-injection machine for the electron circular ring accelerator (Synchrotron). The system works at 2,856 GHz with three power levels: Low Power Subsystem (»100 mW), Medium Power Subsystem(1 kW) and High Power Subsystem (» 25 MW). Theoretical fundamentals, mechanical drawings and experimental results of several microwave components developed for this system are presented and several problems related to high power transmission in waveguides are discussed. Electronic circuits for signal amplitude and phase detection, together with security circuits, developed for the system are also shown. The electron linear accelerator is operational for three years by now / Mestrado / Mestre em Engenharia Elétrica

L’environnement, et en particulier ses propriétés mécaniques, joue un rôle important dans la régulation de la forme, de l’adhésion et de la motilité cellulaires, et plus généralement dans le destin cellulaire. Un grand nombre de travaux a porté sur l’étude de la transduction des signaux physiques, les voies de signalisation associées ainsi que sur la régulation, par des facteurs de transcription, de l’expression génique qui en découle. En revanche, très peu de travaux existent sur les effets des signaux mécaniques dans la régulation de protéines modifiant l’état de la chromatine, alors qu’elles ont montré leur importance dans le destin cellulaire. Lors de cette thèse, nous nous sommes intéressés aux effets de l’environnement mécanique et géométrique sur la distribution d’une protéine pouvant modifier l’état chromatinien (la méthyltransférase SMYD3). Pour cela, nous avons utilisé des micro-patrons d’adhérence cellulaire de formes et d’aires différentes. Nous avons montré que l’aire d’étalement et la forme cellulaire impactent la distribution de SMYD3 au sein de la cellule. Ensuite, nous avons montré que la répartition de certaines marques de méthylation à l’échelle de la cellule est corrélée avec la répartition de la protéine SMYD3 avec une colocalisation dans certain cas. Enfin, nous nous sommes attachés à souligner le lien entre le changement des propriétés géométriques et l’apparition de la redistribution de SMYD3 et mis en évidence le lien entre l’état mécanique, le cytosquelette et la redistribution de SMYD3 / The environment, in particular its mechanical properties, plays an important role in regulating cell shape, cell adhesion and motility, and more generally in cell fate. Many studies have focused on the link between the transduction of physical cues and the regulation of gene expression by transcription factors. However, few studies have investigated the effects of mechanical cues on the regulation of proteins modifying chromatin states despite their importance in cell fate. In this thesis, we investigated the effects of mechanical and geometric environment on the distribution of a protein that can modify the chromatin state (the methyltransferase SMYD3). For this purpose, we used adhesive micropatterns with different shapes and areas. We found that spreading area and cell shape impact the distribution of SMYD3 in the cell. We show that the distribution of certain methylation marks within the cell correlates with SMYD3 distribution and colocalizes in some cases. Finally, we established a link between changes in geometric properties and SMYD3 redistribution and highlighted a link between the mechanical state of the cytoskeleton and the redistribution of SMYD3.

N/A / Thesis / Master of Arts (MA)

Yes / Condition monitoring of micro injection moulding is an effective way of understanding the processing effects of variable parameter settings. This paper reports an experimental study that investigates the characteristics of the demoulding behaviour in micro injection moulding (A mu-IM) with a focus on the process factors that affect parts' quality. Using a Cyclic Olefin Copolyme (COC) microfluidics demonstrator, the demoulding performance was studied as a function of four process parameters (melt temperature, mould temperature, holding pressure and injection speed), employing the design of experiment approach. The results provide empirical evidences on the effect that processing parameters have on demoulding conditions in A mu-IM, and identifies combinations of parameters that can be used to achieve the optimal processing conditions in regards to demoulding behaviour of micro parts. It was concluded that there was a direct correlation between the applied pressure during part filling, holding phases and the demoulding characteristic factors of the A mu-IM cycle such as ejection force, integral and time.

The structures of the exopolysaccharides from a number of strafos of the bacterial genus KlebsieUa have been investigated and compared. ·All of these polysaccharides have been shown to be composed of regularly repeated oligosaccharide units containing -glucuronic acid and three to five hexose residues, with pyruvic acid ketal and 0-acetyl groups also present in some of the polysaccharides. Graded acid hydrolysis, monitored by gel-permeation chromato graphy, has been used to study the degradation of each polysaccharide to the structurally significant oligosaccharides and fragments of higher molecular weight which are clearly aggregates of these units. In all cases both acidic and neutral oligosaccharides have been isolated in a high degree of purity, which has permitted their characterisation by standard techniques, including partial acid hydrolysis and methylation analysis, and the use of proton magnetic resonance spectroscopy and measurement of optical rotatory power to determine the nature of anomeric linkages. The polysaccharides from Klebsiella K4 and X.pnev.moniae ( oxytoca variant) have been shovm to have linear tetra- and pentasaccharide repeating units respectively, while the structures of those from serotypes K27 and K64 have been found to be more complex, consisting of branched hexasaccharide repeating units with pyruvic acid ketallinked to one sugar residue. In addition, the fungal polysaccharides from two strains of c1yptococcus neoformans have been investigated and shovm to be chemically equivalent. The evidence obtained from partial acid hydrolysis, methylation analysis and Smith-degradation studies performed on one of these polysaccharides is consistent with a structure in which a linear (l-+3)- linked chain of -mannose residues is substituted at position C-2 by either g-glucuronic acid or ll_-xylose. This represents one of the few complete characterisations of a Cryptococcus polysaccharide to be achieved up to the present.

Imperceivable World is an immersive multi-media exhibition that allows the audience to explore the imperceivable micro world of various organisms. These microorganisms occupy a space within our world that is so minuscule that it might seem like fiction. A series of short animations are an exploration into how these organisms behave and interact, giving the viewer a brief glimpse into this micro world. Imperceivable World utilizes the Cyclorama, which is a massive cylindrical screen that can display 3D stereoscopic animations which provide the audience a larger than life perspective of these microorganisms. Along with cyclorama Imperceivable World uses the Cube's audio space to give the audience a fully immersive experience. / Master of Fine Arts

L’électroérosion (EE) est une technique d’usinage sans contact de matériaux conducteursd’électricité ; elle particulièrement bien adaptée à l’usinage de matériaux durs. Le principe consiste àcréer des décharges électriques érodantes entre un outil et une pièce à usiner, toutes deuximmergées dans un diélectrique. Dans cette thèse, nous avons étudié la miniaturisation de ceprocédé, la microélectroérosion (μEE), qui se présente comme un procédé complémentaire destechniques de micro-usinage mécanique, laser, ou encore des techniques issues de lamicrotechnologie du silicium (RIE, DRIE, LIGA). Toutefois, la résolution de la μEE est limitée.Dans ce travail, nous avons tout d’abord développé un procédé original d’élaboration de microoutilscylindriques en tungstène par gravure électrochimique. Celui-ci permet d’obtenir de manièrereproductible des micro-outils de diamètre 15 μm et de rapport hauteur sur diamètre supérieur à 50.Des micro-outils plus fins ont aussi été obtenus (jusqu’à 700 nm) mais avec des problèmes dereproductibilité. Par ailleurs, un prototype de machine de fraisage par μEE a été développé avec uneélectronique entièrement caractérisée. Des micro-canaux de 40 μm de largeur ont été obtenus dansl’acier d’inoxydable et 25 μm dans le titane ; une rugosité Ra de 86 nm a été atteinte dans des cavitésde 600 x 600 x 30 μm. Les limitations du dispositif expérimental ont aussi été mises en évidence.Dans la dernière partie de ce travail, nous avons procédé à l’étude des microdécharges et du microplasmas’établissant entre micro-outil et pièce à l’aide de caractérisations électriques. La résistanceet l’inductance des décharges ont été déterminées expérimentalement puis intégrées dans unmodèle permettant de prévoir la durée des impulsions de courant et leur intensité. Des pistes pourl’amélioration de la résolution d’usinage sont proposées en conclusion de ce travail. / Electro Discharge Machining (EDM) is a non-contact technique allowing machining of electricallyconductive materials; it is well adapted for the machining of hard materials. The principle is based onthe creation of eroding electrical discharges between a tool and a piece, both immersed in adielectric. In this thesis, we have the studied miniaturization of the process, called micro electrodischarge machining (μ-EDM), which is considered as a complementary technique of mechanical orlaser micro-machining techniques and silicon micro technology processes (RIE, DRIE, LIGA)..However, the resolution of μEDM is limited.In this work, we have firstly developed an original method for making tungsten micro-tools withcylindrical profile by electrochemical etching. This method allows the reproducible fabrication ofmicro-tool with 15-μm diameter. Thinner micro-tools were also obtained (down to 700 nm) withreproducibility problems. Furthermore, a prototype machine for milling μ-EDM was developed with afully characterized electronics. Micro channels were obtained respectively in stainless steel with awidth of 40μm and in titanium with a width of 25μm; a surface roughness Ra of 86 nm was achievedin 600 x 600 x 30 μm cavities. Besides, the limitations of the apparatus were highlighted. In the lastpart of this work, we have studied the micro-discharge and the micro-plasma between the micro-tooland the part with electrical characterization. The resistivity and the inductance of the sparks weremeasured and integrated in a numerical model in order to explain the duration of the microdischarges and their intensity. Solutions for improving the machining resolution are also discussed atthe end of this work.

Ce travail est une contribution à la conception d'un système portatif et intégré de type µTAS (micro-Total Analysis System) pour le traitement (préconcentration et simplification) de solution aqueuses contenant des métaux lourds et leur analyse en ligne. Pour la préconcentration amont, l'étude a porté sur la réalisation d'un micro-électrodialyseur manipulant des µL de solutions. L'optimisation des paramètres opératoires a permis d'augmenter d'un facteur 100 environ les concentrations d'analytes. Pour l'étage de détection aval, un système sur puce de type polarographique a été étudié. Le traditionnel mercure est remplacé par du diamant polycristallin dopé au bore (DDB) préparé par CVD micro-ondes. La quantification des métaux lourds par redissolution anodique sur ce matériau a été validée ainsi que les techniques de gravure compatibles avec la réalisation de microréseaux d'électrodes. / This work is a contribution to the conception of an integrated μTAS (micro-Total Analysis System) for treatment (preconcentration and simplification) of aqueous solutions containing heavy metals and their on-line analysis. For upstream preconcentration, a micro-electrodialyser handling µL of solutions was developped. The optimization of operating parameters permitted to reach an analyte pre-concentration factor of about 100. For the downstream detection step, an on-chip polarographic system, where mercury was replaced by boron doped diamond (BDD), was studied. BDD films were prepared by assited microwave plasma CVD. Quantification of heavy metals by anodic stripping on BDD was validated as well as the etching technique compatible with the realization of microarray electrodes.