Submitted by Eliselle Gouveia de Faria null (lellyfaria@hotmail.com) on 2018-01-29T18:07:11Z No. of bitstreams: 1 Tese_Eliselle_Gouveia_de_Faria_Biteli.pdf: 4027081 bytes, checksum: b84e13a67ab48c05a1dd9f39c2d8be6d (MD5) / Approved for entry into archive by Karina Gimenes Fernandes null (karinagi@fcav.unesp.br) on 2018-01-30T12:17:05Z (GMT) No. of bitstreams: 1 biteli_egf_dr_jabo.pdf: 4011438 bytes, checksum: 5575bda6c7245c490c94543e9cbca487 (MD5) / Made available in DSpace on 2018-01-30T12:17:05Z (GMT). No. of bitstreams: 1 biteli_egf_dr_jabo.pdf: 4011438 bytes, checksum: 5575bda6c7245c490c94543e9cbca487 (MD5) Previous issue date: 2017-12-18 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Compararam-se os efeitos de diferentes frações inspiradas de oxigênio (FiO2) associado ao óxido nitroso (N2O) ou ao ar comprimido sobre a hematose, parâmetros cardiorrespiratórios, intracranianos e o índice biespectral (BIS), em leitões mantidos em ventilação espontânea ou controlada a pressão, associada ou não à PEEP (5 cmH2O). Foram utilizados 48 leitões, distribuídos em 6 grupos, submetidos à 10, 30 e 50% de ar comprimido (GA10, GA30 e GA50) ou N2O (GN10, GN30 e GN50), associadas às FiO2 de 0,9, 0,7 e 0,5, respectivamente. O GA30 mostrou maior proximidade do intervalo fisiológico da pressão parcial de oxigênio no sangue arterial. A PEEP não foi eficaz na pressão parcial de dióxido de carbono no sangue arterial, independente da FiO2, quando se utilizou o N2O. O pH, déficit base e bicarbonato no sangue arterial foram influenciados pela FiO2 e N2O. As alterações do volume corrente e volume minuto parecem correlacionadas à introdução da ventilação mecânica (VM) e PEEP. Na diferença alvéolo-arterial de oxigênio, a PEEP influenciou negativamente o GA30 e GN30 e não foi adequada para manutenção do shunt pulmonar. Já a pressão média da artéria pulmonar e pressão média capilar pulmonar apresentaram acréscimos após introdução da PEEP. A associação da PEEP com N2O (50%) ou ar comprimido (50%) parece ser a receita para desempenho inferior da variação de pressão de pulso. Para a pressão intracraniana, apenas o GN30 apresentou valor menor ao se instituir a VM quando comparado com o momento em que houve início do auxílio com a PEEP. Concluiu-se que, nenhuma concentração de N2O é segura para a manutenção dos parâmetros hemogasométricos. A VM e a PEEP não são eficientes para manutenção das variáveis respiratórias. A PEEP promove piora no desempenho de parâmetros cardiovasculares e intracranianos. Maiores taxas de oferta de N2O (50%) reduzem o BIS em suínos. / The effects of different fractions of inspired oxygen (FiO2) associated with compressed air or nitrous oxide (N2O) on lung oxygenation, cardiorespiratory parameters, intracranial parameters and the bispectral index (BIS) were compared in piglets maintained under spontaneous or controlled ventilation, with or without PEEP (5 cmH2O). Forty-eight piglets, distributed in six groups, were submitted to 10, 30 and 50% of compressed air (GA10, GA30 and GA50) or N2O (GN10, GN30 and GN50), associated with FiO2 of 0.9, 0.7 and 0.5, respectively. GA30 showed greater proximity to the physiological range of partial oxygen pressure in the arterial blood. When N2O was used, PEEP was ineffective in maintaining partial carbon dioxide pressure in the arterial blood, independent of FiO2. Arterial blood pH, base deficit and bicarbonate were influenced by FiO2 and N2O. Changes in tidal and minute volumes seem to correlate with the introduction of mechanical ventilation (MV) and PEEP. The difference in alveolar-arterial oxygen under PEEP negatively influenced GA30 and GN30 and was inadequate for pulmonary shunt maintenance. Mean pulmonary artery pressure and mean capillary pulmonary pressure increased following the initiation of PEEP. The association of PEEP with N2O (50%) or compressed air (50%) seems to result in lower performance of pulse pressure variation. Regarding intracranial pressure, only GN30 presented a lower value when MV was established compared with the time point when PEEP was initiated. In conclusion, no concentration of N2O is safe for maintaining blood gas parameters. MV and PEEP are inefficient in the maintenance of respiratory variables. PEEP promotes deterioration in the performance of cardiovascular and intracranial parameters. Higher N2O supply rates (50%) reduce BIS in pigs. / 2013/25655-0

M.Ing. (Electrical and Electronic Engineering) / Long transmission lines in power system require high line loading in order to lower voltage limits due to line losses. For relatively long lines, line charging is high and thus higher voltage limits reached at low loading. It follows then that it is a challenge to maintaining the voltages between the acceptable limits for relatively long lines. This dissertation highlights the problems experienced when load varying from very low to very high is supplied by very long parallel lines of different impedance characteristic. When the load is extremely high, there are low voltages experienced which are solved by use of shunt capacitors and/or adding more lines. When the load is extremely low, there are high voltages experienced which are solved by use of shunt reactors and/or switching some of the lines off. The type of solutions to this two loading extremes as indicated above, can be problematic, in that; new lines requires servitudes which can take too long, shunt capacitors and reactors in this type of the network is not desirable since the introduction of too many of these devices have maintenance implications and they would require continuous switching to maintain acceptable voltages, resulting in complicated operation of the network. This research proposes the use of a phase shifting transformer located on one of two parallel corridors supplying power to a load located remotely from the rest of the system. The transformer is able to rearrange the active power flows to vary loadings of the corridors and the improvements in voltage regulation can be realised during both low and high load conditions.

The blood flow through the Bidirectional Glenn shunt (BGS) and modified Blalock-Taussig shunt (mBTS) to the pulmonary arteries (PAs) was analyzed using Computational Fluid Dynamics. This study consisted of the steady and pulsatile cases. In case one, the results of blood flow through the BGS for the Newtonian and non-Newtonian viscosity models were compared. Case two focused on having an additional pulsatile blood flow through the mBTS using the non-Newtonian Carreau viscosity model. The geometries were created based on the angiograms. In case one, boundary conditions to be specified at the inlets were obtained from the flow rate measurements via Doppler flow studies in children and young adults. The averaged velocities were obtained from these flow rates and specified as parabolic velocity profiles at the inlets. The average PA pressures were obtained from the catheterization data and specified at the branches of the PA outlets. In case two, boundary conditions at the same inlets were constant during the cardiac cycle. The pulsatile PA and aortic pressure tracings obtained from the catheterization data were specified at the outlets and mBTS inlet, respectively. A comparison is made between the first and second case results.

Neste trabalho são exploradas as potencialidades e efeitos de possíveis aplicações do UPFC (Unified Power Flow Controller) em redes elétricas. Este recente equipamento da família FACTS, apesar de mais complexo, apresenta rapidez e versatilidade de respostas que podem justificar sua aplicação em redes elétricas. São apresentados modelos matemáticos deste dispositivo, para regime permanente e transitório, utilizando transformações para coordenadas ortogonais. Com base nas respostas obtidas, durante as simulações das aplicações estudadas, pode-se constatar que a tensão série e seu posicionamento angular, introduzidos pelo UPFC, desempenham um importante papel no controle rápido e eficiente do fluxo de potência. Como contribuição deste trabalho, explorou-se a conexão do conversor shunt ao enrolamento terciário de autotransformadores, demonstrando a viabilidade do controle do fluxo de potência nestes equipamentos de transformação. O esquema proposto, instalado em transformadores em paralelo, eleva a disponibilidade de operação do UPFC, aumentando a flexibilidade operativa do sistema em implementações práticas. Através da formulação apresentada, o transformador de acoplamento shunt, convencionalmente utilizado pelo UPFC, apresenta dimensões reduzidas. Foi também examinada a possibilidade de limitação de correntes de curto-circuito, equilibrados ou não, com a ação dos controles do UPFC, particularmente, aprofundando a análise do seu desempenho mais eficiente diante de curtos monofásicos. Os resultados satisfatórios obtidos permitem considerar a viabilidade de limitação destas correntes como um subproduto interessante da atuação deste dispositivo FACTS. / In this thesis, the UPFC (Unified Power Flow Controller) various capabilities and effects for possible network applications, are studied. Although its structure is relatively more complex, when compared to the other FACTS controllers, its fast response and versatility can justify its application within the network. By utilising the orthogonal co-ordinates transform both the steady-state and transient mathematical models of the UPFC, are presented herein. Based on the results obtained and regarding the applications studied, it can be stated that the UPFC series voltage along with its phase angle play an important role for the fast and efficient control of the power flow. As a contribution of the present work, it has been proposed the connection of the shunt converter to the tertiary winding of autotransformers, demonstrating in this way the feasibility for controlling the power flow over such transforming assets. The proposed scheme, which regards two paralleled transformers, offers the UPFC a high operation availability increasing the system operative flexibility in actual implementations. By means of the proposed approach, the shunt coupling transformer, usually utilised in a classical UPFC configuration, presents a reduced size. Also, by utilising the UPFC control actions, it has been examined the possibility of short-circuit limitation over balanced and unbalanced circuits. Particularly, it has been analysed the UPFC most efficient performance towards line-to-ground faults. The satisfactory results obtained lead to consider the UPFC feasibility in limiting such currents; this, as an interesting by-product of this FACTS device action.

Neste trabalho são exploradas as potencialidades e efeitos de possíveis aplicações do UPFC (Unified Power Flow Controller) em redes elétricas. Este recente equipamento da família FACTS, apesar de mais complexo, apresenta rapidez e versatilidade de respostas que podem justificar sua aplicação em redes elétricas. São apresentados modelos matemáticos deste dispositivo, para regime permanente e transitório, utilizando transformações para coordenadas ortogonais. Com base nas respostas obtidas, durante as simulações das aplicações estudadas, pode-se constatar que a tensão série e seu posicionamento angular, introduzidos pelo UPFC, desempenham um importante papel no controle rápido e eficiente do fluxo de potência. Como contribuição deste trabalho, explorou-se a conexão do conversor shunt ao enrolamento terciário de autotransformadores, demonstrando a viabilidade do controle do fluxo de potência nestes equipamentos de transformação. O esquema proposto, instalado em transformadores em paralelo, eleva a disponibilidade de operação do UPFC, aumentando a flexibilidade operativa do sistema em implementações práticas. Através da formulação apresentada, o transformador de acoplamento shunt, convencionalmente utilizado pelo UPFC, apresenta dimensões reduzidas. Foi também examinada a possibilidade de limitação de correntes de curto-circuito, equilibrados ou não, com a ação dos controles do UPFC, particularmente, aprofundando a análise do seu desempenho mais eficiente diante de curtos monofásicos. Os resultados satisfatórios obtidos permitem considerar a viabilidade de limitação destas correntes como um subproduto interessante da atuação deste dispositivo FACTS. / In this thesis, the UPFC (Unified Power Flow Controller) various capabilities and effects for possible network applications, are studied. Although its structure is relatively more complex, when compared to the other FACTS controllers, its fast response and versatility can justify its application within the network. By utilising the orthogonal co-ordinates transform both the steady-state and transient mathematical models of the UPFC, are presented herein. Based on the results obtained and regarding the applications studied, it can be stated that the UPFC series voltage along with its phase angle play an important role for the fast and efficient control of the power flow. As a contribution of the present work, it has been proposed the connection of the shunt converter to the tertiary winding of autotransformers, demonstrating in this way the feasibility for controlling the power flow over such transforming assets. The proposed scheme, which regards two paralleled transformers, offers the UPFC a high operation availability increasing the system operative flexibility in actual implementations. By means of the proposed approach, the shunt coupling transformer, usually utilised in a classical UPFC configuration, presents a reduced size. Also, by utilising the UPFC control actions, it has been examined the possibility of short-circuit limitation over balanced and unbalanced circuits. Particularly, it has been analysed the UPFC most efficient performance towards line-to-ground faults. The satisfactory results obtained lead to consider the UPFC feasibility in limiting such currents; this, as an interesting by-product of this FACTS device action.

Afin de réduire les vibrations d'une structure, on utilise des éléments piézoélectriques connectés à des circuits électriques passifs. L'objectif est de se rapprocher de l'efficacité du contrôle actif sans en supporter la complexité et la consommation. On considère d'abord l'association d'une résistance (qui a un effet similaire à un amortissement visqueux) et éventuellement d'une inductance (permettant de réaliser un oscillateur accordé) aux éléments piézoélectriques. Ces systèmes ont des propriétés intéressantes, mais sont peu efficaces à moins d'un accord très précis de l'inductance. Afin d'obtenir des performances élevées sans accord précis, on étudie un circuit à commutation, qui se ferme et s'ouvre à des instants bien précis. L'effet de la charge, qui freine la structure, s'apparente à un frottement sec. En synchronisant les commutations sur les vibrations, le système est auto-adaptatif et peut être auto-alimenté. Les fortes non-linéarités entraînent une excitation haute fréquence de la structure qui peut rendre la synchronisation problématique. Deux modèles électromécaniques (analytique et éléments finis) réduits sont proposés, permettant de décrire la dynamique du système complet de manière précise et de mettre en valeur le couplage entre un mode de vibration et le circuit électrique. Ce couplage est déterminant pour la réduction de vibrations. Une étude de l'influence de divers paramètres permet d'optimiser les éléments piézoélectriques, les circuits, et les instants de commutation. Ces résultats sont vérifiés expérimentalement. On constate un bon accord avec la théorie ; la difficulté de synchroniser correctement la commutation est aussi constatée. / In order to reduce the vibrations of a mechanical structure, one can use piezoelectric elements connected to passive electrical circuits. The goal is to achieve the same efficiency as active vibration control without the associated complexity and energy consumption. First the use of a resistor (with an effect similar to viscous damping) and eventually of an inductor (allowing the creation of a tuned resonator) for the circuit is considered. These systems have interesting properties, but are not very efficient, except in the case of a finely tuned inductor. In order to obtain good performance without requiring a precise tuning, a switching circuit is considered. The switching process is synchronized on the vibrations, and the effect of the free electric charge (similar to a dry damping) reduces the vibrations. This system is self-adaptive and can be self-powered. However, the strong non-linearities create a high frequency excitation which may disturb the switch timing. Two different reduced electromechanical models (analytical and finite element) are proposed, allowing a description of the whole system dynamics with accuracy and to emphasize the coupling between one vibration mode and the circuit. This coupling is found to be decisive for the performance in vibration reduction. A study of the influence of various parameters allow the optimisation of the piezoelectric elements, electric circuits and switch timing. These results are experimentally tested and a good agreement with the predictions is obtained ; the difficulty of switch timing is also noticed.

Maschinelle Beatmung kann eine vorbestehende Lungenerkrankung weiter aggravieren und das Lungenparenchym zuvor lungengesunder Patienten schädigen. Pulmonale Atelektasen können diese Schädigung noch verstärken. Aus diesem Grund ist es erstrebenswert das Auftreten von Atelektasen frühzeitig zu erkennen und zu quantifizieren, um Gegenmaßnahmen wie Rekrutierung oder PEEP-Applikation zu ergreifen. Den aktuellen Goldstandard zur Detektion und Quantifizierung von Belüftungsstörungen stellt die quantitative Analyse mittels Computertomographie (qCT) dar, welche jedoch nur mit hohem Aufwand und potenziellen Risiken für den Patienten durchführbar ist. Wir untersuchten daher anhand von 14 Schafen mit gesunden Lungen die Beziehung zwischen Atelektasen und intrapulmonaler Shuntfraktion sowie dem arteriellen Sauerstoffpartialdruck (PaO2) mit dem Hintergrund, eine möglichst bettseitig durchführbare Alternative zur qCT zum Zwecke der Quantifizierung der pulmonalen Atelektasen zu erhalten. Die Quantifizierung der Atelektasen könnte es ermöglichen, die Notwendigkeit einer Beatmungsoptimierung festzustellen und deren Erfolg zu beurteilen. Hierzu wurden die o.g. Schafe standardisiert mit einer inspiratorischen Sauerstofffraktion von 1 maschinell beatmet und das nichtbelüftete Lungengewebe mittels qCT quantifiziert. Parallel wurden der arterielle und gemischt-venöse Sauerstoffpartialdruck gemessen sowie die Shuntfraktion berechnet. Mittels Regressionsanalyse konnte eine starke Korrelation zwischen nichtbelüftetem Lungengewebe und natürlichem Logarithmus des PaO2 (R2=0,8) einerseits und der Shuntfraktion (R2=0,83) andererseits aufgezeigt werden. Aufgrund der Ergebnisse scheint es möglich über eine einfache Messung des PaO2 oder Berechnung des Shunts Rückschlüsse auf das Ausmaß der Atelektasen zu ziehen und so durch geeignete Gegenmaßnahmen die beatmungsassoziierte Schädigung von Lungenparenchym zu reduzieren.

New materials and new fabrication techniques in turbomachinery lead to monolithic<p>structures with extremely low damping which may be responsible for severe vibrations<p>and possible high-cycle fatigue problems. To solve this, various techniques<p>of damping enhancement are under investigation. The present work is focused on<p>piezoelectric shunt damping.<p>This thesis considers the RL shunt damping of rotationally periodic structures using<p>an array of piezoelectric patches, with an application to a bladed drum representative<p>of those used in turbomachinery. Due to the periodicity and the cyclic symmetry of<p>the structure, the blade modes occur by families with very close resonance frequencies,<p>and harmonic shape in the circumferential direction; the proposed RL shunt<p>approaches take advantage of these two features.<p>When a family of modes is targeted for damping, the piezoelectric patches are<p>shunted independently on identical RL circuits, and tuned roughly on the average<p>value of the resonance frequencies of the targeted modes. This independent<p>configuration offers a damping solution effective on the whole family of modes, but<p>it requires the use of synthetic inductors, which is a serious drawback for rotating<p>machines.<p>When a specific mode with n nodal diameters has been identified as critical and<p>is targeted for damping, one can take advantage of its harmonic shape to organize<p>the piezoelectric patches in two parallel loops. This parallel approach reduces considerably<p>the demand on the inductors of the tuned inductive shunt, as compared<p>to independent loops, and offers a practical solution for a fully passive integration<p>of the inductive shunt in a rotating structure.<p>Various methods are investigated numerically and experimentally on a cantilever<p>beam, a bladed rail, a circular plate, and a bladed drum. The influence of blade<p>mistuning is also investigated. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

In recent years precision measurement of alternating currents goes through large progress especially because of improvements in metrology of electric power, which is related to reduction of electricity consumption. Therefore, more precise measurement of electric energy, power and power quality is required. Measurement range is extending and number of measured frequency points is growing up to 100 kHz. Development of current to voltage transducer with normalized output voltage (0,5 V - 1 V) is in progress because of their easy integration in different measuring systems.. From big area of alternating current metrology this dissertation focuses on development of improved cage shunts for measurement of alternating currents in range 10 mA - 100 A, 10 Hz - 100 kHz. Main objective of this dissertation is to develop theoretical model of existing cage shunts, which will assist design of new improved cage shunts construction. In this dissertation the analytical model of CMI’s cage shunts was established, based on calculating of trans-impedance from cascade matrix of passive two-port which is representing the shunt. Trans-impedance can be used for AC-DC difference and phase error calculation, which are two basic parameters of shunts. Uncertainty analysis of the model was done by means of Monte Carlo method. Next, this dissertation also concentrates on suitable measurement methods of phase error, AC-DC difference, and power a temperature coefficient of resistance. These measurements method were used for calibration of existing CMI’s cage shunts and so the model’s verification was made. Finally, theoretical optimization of existing CMI’s cage shunts constructions and theoretical designs of 20A, 50A and 100A shunts were done using sensitivity analysis results.

The purpose of this study was to generate a greater understanding of how the shunt distance affects the shunting phenomena which occurs when working with resistance spot welding (RSW). Shunting affects the quality of the weld and the goal of the study was to create guidelines for RSW to minimize its impact on the weld quality. In order to minimize waste from production and to reduce the welding time there is need for understanding of what the shunt effect depends on. To evaluate what impact the shunt distance will have on the weld, two different experiments were performed. In the first experiment, a one-dimensional welding lobe was manufactured for various materials and the current range was compared over three different shunt distances. The second experiment consisted of welding with a constant current on different shunt distances to investigate how this would impact the second weld performed in the welding sequence. A range of different steel grades and sheet thicknesses was used in the experiments to further explore what impact different material properties will have on the shunt effect. The result showed that the shunt distance has little impact on the acceptable weld-current range, with minor deviations. However, the shunt distance will affect the size of the shunted weld, which decreases as the shunt distance is reduced. Overall, the data collected in this study is not expansive enough to make guidelines that could be implemented in today´s industry. The phenomena of shunting require more data to fully be understood. / Syftet med denna studie var att skapa en större förståelse för hur shuntavståndet påverkar det shunt-fenomen som uppstår när man arbetar med punktsvetsning (RSW). Shuntning påverkar svetsens kvalitet och målet var att skapa riktlinjer för arbete med RSW för att minimera shunt-effektens påverkan på svetsen. I syfte att kunna minimera spill i produktionen samt att minska svetstiden krävs det förståelse av vad shunt effekten beror på. För att utvärdera vilken påverkan shuntavståndet kommer att ha på svetsen utfördes två olika experiment. I det första experimentet skapades en endimensionell svetslob för varje material och det genererade strömintervallet jämfördes över tre olika shuntavstånd. Det andra experimentet bestod av svetsning med en lika stor ström vid olika shuntavstånd för att undersöka hur detta skulle påverka den andra svetsen. En rad olika stålsorter och plåttjocklekar användes för att ytterligare se vilken påverkan dessa faktorer kom att ha på shunteffekten. Resultatet visade att shuntavståndet hade liten inverkan på det acceptabla svetsströmintervallet, med mindre avvikelser. Emellertid påverkar shuntavståndet storleken på den shuntade svetsen genom att storleken minskar när shuntavståndet minskas. Sammantaget räcker inte de uppgifter som samlats in i denna studie för att skapa riktlinjer som skulle kunna implementeras i dagens industri, utan det krävs mer data för att fullständigt kartlägga shunteffekten.