L'alternateur à griffes est l'alternateur le plus utilisé dans l'industrie automobile. Afin d'augmenter sa puissance volumique, une solution classique consiste à utiliser des aimants NdFeB entre les griffes. Ces dernières années, le prix des aimants NdFeB a beaucoup augmenté remettant en question leur utilisation. Ce contexte implique de trouver de nouvelles solutions techniques permettant de conserver la même puissance volumique sans utiliser d'aimant NdFeB. Dans le cadre de ces travaux de thèse la solution proposée consiste a utiliser des matériaux magnétiques doux nobles tels que les FeCo (AFK18, AFK1 et AFK502). De part leur coût élevé, nous avons limité leur utilisation au noyau de l'alternateur même si leur utilisation au rotor est également évaluée. Ces travaux s'appuient sur une démarche de dimensionnement multi-niveaux (modèle reluctant et modèle éléments finis) ce qui apporte un bon compromis temps de calcul/précision. Une série d'études a été réalisée avec dans un premier temps, l'identification d'une géométrie de noyau favorable à l'utilisation de noyau en FeCo. Dans un second temps, une étude compare les courants batteries en fonction du FeCo utilisé au noyau avec une optimisation du rotor. Ensuite une étude présente le dimensionnement complet de l'alternateur (optimisation du rotor et du stator avec une étude sur le nombre optimal de paires de pôles) avec un noyau en AFK502 ce qui d'identifier le gain maximal en courant batterie apporté par l'utilisation d'un noyau en FeCo. Pour finir, une dernière étude compare les courants batteries en fonction du FeCo utilisé au rotor avec une optimisation du rotor et du stator. / Claw-pole alternators are often used in automotive industry. Permanent magnets like NdFEB are currently integrated to increased the power density of claw-pole machine. However their higher price brings into question their usage. This tight context implies finding new technical solutions to keep the same power density without NdFeB magnets. The solution adopted consists to evaluate the potential of gain with different soft magnetic materials and more especially FeCo family (AFK18, AFK1 et AFK502). Their higher price imposed us to use FeCo just at the core of the alternator but we have also evaluate their usage at the rotor. This work is based on an adapted design methodology including two modeling level (magnetic equivalent circuit model and finite element model) in order to obtain a good compromise between time computation/accuracy. Several studies have been made with, as a first step, the identification of new core geometry customized for FeCo core. As a second step, a study comparing output current according to FeCo used at the core is presented, rotor is optimized only. As a third step, is exposed the global optimization of the alternator with an AFK502 (rotor and stator optimization with a study on the optimal poles pairs number) in order to identify the maximum output current gain with an FeCo core. Finally, the last study compare output current according to FeCo used at the rotor, rotor and stator are optimized .

In structural graph theory, connectivity is an important notation with a lot of applications. Tutte, in 1961, showed that a simple graph is 3-connected if and only if it can be generated from a wheel graph by repeatedly adding edges between nonadjacent vertices and applying vertex splitting. In 1971, Halin constructed a class of edge-minimal 3-connected planar graphs, which are a generalization of wheel graphs and later were named “Halin graphs” by Lovasz and Plummer. A Halin graph is obtained from a plane embedding of a tree with no stems having degree 2 by adding a cycle through its leaves in the natural order determined according to the embedding. Since Halin graphs were introduced, many useful properties, such as Hamiltonian, hamiltonian-connected and pancyclic, have been discovered. Hence, it will reveal many properties of a graph if we know the graph contains a spanning Halin subgraph. But unfortunately, until now, there is no positive result showing under which conditions a graph contains a spanning Halin subgraph. In this thesis, we characterize all forbidden pairs implying graphs containing spanning Halin subgraphs. Consequently, we provide a complete proof conjecture of Chen et al. Our proofs are based on Chudnovsky and Seymour’s decomposition theorem of claw-free graphs, which were published recently in a series of papers.

A Uncaria tomentosa (Willd.) DC., comumente conhecida como unha de gato ou cat´s claw, é uma planta endêmica da Amazônia Peruana. Devido às suas propriedades terapêuticas, seus extratos e derivados são comercializados ao redor do mundo. As propriedades medicinais são atribuídas aos glicosídeos do ácido quinóvico, polifenois e especialmente aos alcalóides oxinólicos pentacíclicos. Assim, a mitrafilina é o principal alcalóide presente nos extratos da planta e, portanto, é o marcador químico de suas formulações comerciais. O processo de extração é uma etapa importante na padronização de seus extratos e, considerando a falta de estudos a respeito de sua influência sob o perfil fitoquímico, amostras de casca de unha de gato foram extraídas por meio de maceração dinâmica e extração assistida por micro-ondas. O objetivo desse estudo foi avaliar a influência dos fatores envolvidos no processo extrativo a respeito de sua composição química, atividade anti-inflamatória e antioxidante. Devido ao grande número de fatores de extração a serem avaliados, um planejamento experimental do tipo Placket Burman foi selecionado e os fatores escolhidos nessa etapa foram: porcentagem de planta em solvente, temperatura e tempo de extração. Adicionalmente, através de um planejamento Box Behnken, as condições ótimas de extração foram delineadas na segunda etapa do estudo. O tempo e a porcentagem de planta em solvente foram fatores significantes para a extração assistida por micro-ondas. Entretanto, o conteúdo de mitrafilina nesses extratos foi reduzido - comparativamente ao seu conteúdo total presente nas amostras analisadas - e, portanto, mais estudos são necessários para otimizar o seu rendimento. Além disso, o extrato otimizado foi avaliado quanto à capacidade anti-inflamatória, em um teste de edema de pata induzido por carragenina e apresentou uma capacidade inibitória na concentração de 0,57 mg de mitrafilina/ Kg de rato. Por conseguinte, tais achados confirmaram a sua atividade anti-inflamatória. Os resultados obtidos a partir da extração por maceração dinâmica sugerem que o alcalóide é facilmente extraído, pois não foi afetado por nenhuma das variáveis experimentais. Adicionalmente, os extratos apresentaram maior conteúdo de mitrafilina - comparativamente aos resultados observados na extração por micro-ondas. Entretanto, devido ao menor tempo empregado na extração assistida por micro-ondas, outros estudos são necessários a fim de otimizar a extração desse alcalóide por esse método. O extrato otimizado sob as condições de maceração dinâmica foi seco em spray drying e, utilizando um planejamento de mistura do tipo simplex-centroid, o efeito de diferentes misturas de três adjuvantes foi avaliado: Dmanitol, maltodextrina e Aerosil. Embora os extratos secos com Aerosil e maltodextrina tenham prevenido a degradação de mitrafilina - quando comparado ao extrato seco sem excipiente - a secagem resultou em elevada perda no conteúdo de alcalóide e também propriedades farmacotécnicas inadequadas. Tais observações sugerem que, mesmo em condições amenas de secagem, há a degradação do alcalóide. Portanto, tais resultados reforçam a necessidade de avaliações complementares a fim de prevenir a ocorrência de tais eventos / The Uncaria tomentosa (Willd.) DC. commonly known as unha-de-gato or cat´s claw is an endemic plant from the Peruvian Amazon. Due its therapeutic properties, the crude drug and a variety of extracts are commercialized worldwide. The healing properties are attributed to the glycosides of quinovic acid, polyphenols, and especially to the pentacyclic oxindole alkaloids. Thereby, mitraphylline is the main alkaloid present in the bark extract of U. tomentosa, and therefore, is the chemical marker of commercial formulations derived from the plant. The extraction process is an important step in the standardization of plant extract and considering the lack of studies that relate the influence of extractive processes in phytochemical profile of the cat´s claw extracts, the bark samples were extracted by dynamic maceration and microwave assisted extraction. The study aimed evaluate the influence of the extraction factors on the chemical composition, antioxidant and anti-inflammatory activities of the extracts from cat \'s claw barks. Due to the wide number of possible extraction factors to be evaluated and the lack of knowledge about the importance of this factor effects on U. tomentosa extract, the Placket Burman factorial design was selected and the experimental factors chosen in this step were: % plant solvent ratio, temperature and extraction time. Through a Box Behnken planning the optimal extraction conditions of cat´s claw bark will be outlined in the second stage of this work. The time and % plant solvent ratio were significant factors for microwave assisted extraction. However, the contents extracted of mitraphylline have been reduced - compared to the total yield of the plant - and, therefore, more studies are needed to optimize the alkaloid yield. The extract from the optimized conditions, was evaluated in carrageenan-induced rat paw oedema, and presented inhibitory capacity in concentration of 0.57 mg of mitraphylline / kg of rat. Therefore, these findings confirm its anti-inflammatory activity. The results obtained in the extractions by dynamic maceration, suggest that the alkaloid is easily extracted and is not affected by experimental variables. In addition, compared to microwave extraction, this methodology allowed extracts with higher content of mitraphylline. However, in view of the shorter extraction time employed in microwave extraction, other reviews are needed to increase the extraction of mitraphylline, by this method. The extract optimized by the conditions under dynamic maceration was dried in spray drying and using a simplex-centroid mixture design, the effect of different mixtures of three adjuvants - D- mannitol, maltodextrin and Aerosil- were evaluated. Although dried extracts with the aid of Aerosil and maltodextrin slightly prevented the degradation of mitraphylline - as compared to the dry extract without excipient - the drying process resulted in high loss in the total content of this alkaloid and inadequate physical properties. Such observation suggests that, even under the mild drying conditions, there is degradation of the alkaloid. Therefore, these results reinforce the need for auxiliary evaluations to prevent the occurrence of such events.

This dissertation proposes several simple, robust, and non-intrusive condition monitoring methods for induction motors fed by closed-loop inverters and claw-pole generators with built-in rectifiers. While the flexible energy forms synthesized by power electronic converters greatly enhance the performance and expand the operating region of induction motors and claw-pole generators, they also significantly alter the fault behavior of these electric machines and complicate the fault detection and protection. In this dissertation, special characteristics of the connected closed-loop inverter and rectifier have been thoroughly analyzed, with particular interest in their impact on fault behaviors of the induction motor and the claw-pole generator. Based on the findings obtained from the theoretical and experimental analysis, several sensorless thermal, mechanical, and insulation monitoring methods are proposed by smartly utilizing special features and capabilities of the connected power electronic converter. A simple and sensitive stator turn-fault detector is proposed for induction motors fed by closed-loop inverter. In addition, a stator thermal monitoring method based on active DC current injection and direct voltage estimation is also proposed to prevent the closed-loop controlled induction motors from thermally overloading. The performance of both methods is demonstrated by extensive experimental results. Methods to detect serpentine belt slip, serpentine belt defect, rotor eccentricity have been proposed for claw-pole generators using only the available electric sensor information. Methods to detect and protect stator turn faults in claw-pole generators are also presented in this dissertation. Lastly, a novel method to detect the generalized bearing roughness fault is proposed. All the proposed condition monitoring techniques have been validated by experimental results.

Vacuum technology is ubiquitous in the high tech industries and scientific endeavors. Since vacuum pumps are critical to operation, semiconductor manufacturers desire reliable operations, ability to schedule downtime, and less costly maintenance services. To better cope with difficult maintenance issues, interests in novel fault diagnosis techniques are growing. This study concerns model based fault diagnosis and isolation (MB-FDI) of dry vacuum pumps in the semiconductor industry. Faults alter normal operation of a vacuum pump resulting in performance deviations, discovered by measurements. Simulations using an appropriate mathematical model with suitably chosen parameters can mimic faulty behavior. This research focuses on the construction of a detailed multi-stage dry vacuum pump model for MB-FDI, and the development of a simple and efficient FDI method to analyze common incipient faults such as particulate deposition and gas leak inside the pump. The pump model features 0-D thermo-fluid dynamics, scalable geometric representations of Roots blower, claw pumps and inter-stage port interfaces, a unified pipe model seamlessly connecting from free molecular to turbulent regimes, sophisticated internal leakage model considering true pump geometry and tribological aspects, and systematic assembly of a multi-stage configuration using single stage pump models. Design of a simple FDI technique for the dry vacuum pump includes staged fault simulations using faulty pump models, parametric study of faulty pump behaviors, and design of a health indicator based on classification. The main research contributions include the developments of an accurate multi-stage dry pump model with many features not found in existing pump models, and the design of a simple MB-FDI technique to detect and isolate the common faults found in dry vacuum pumps. The proposed dry pump model can pave the way for the future development of advanced MB-FDI methods, also performance improvement of existing dry vacuum pumps. The proposed fault classification charts can serve as a quick guideline for vacuum pump manufactures to isolate roots causes from faulty symptoms. / text

No description available.

The problem of defining cycles in infinite graphs has received much attention in the literature. Diestel and Kuhn have proposed viewing a graph as 1-complex, and defining a topology on the point set of the graph together with its ends. In this setting, a circle in the graph is a homeomorph of the unit circle S^1 in this topological space. For locally finite graphs this setting appears to be natural, as many classical theorems on cycles in finite graphs extend to the infinite setting. A Hamilton circle in a graph is a circle containing all the vertices of the graph. We exhibit a necessary and sufficient condition that a countable graph contain a Hamilton circle in terms of the existence of Hamilton cycles in an increasing sequence of finite graphs. As corollaries, we obtain extensions to locally finite graphs of Zhan's theorem that all 7-connected line graphs are hamiltonian (confirming a conjecture of Georgakopoulos), and Ryjacek's theorem that all 7-connected claw-free graphs are hamiltonian. A third corollary of our main result is Georgakopoulos' theorem that the square of every two-connected locally finite graph contains a Hamilton circle (an extension of Fleischner's theorem that the square of every two-connected finite graph is Hamiltonian).

Die subklinische Klauenrehe stellt als Ausgangspunkt für eine Vielzahl daraus resultierender Klauenerkrankungen einen wichtigen Faktor in Bezug auf Tierschutz und Wirtschaftlichkeit von Hochleistungsmilchkühen dar. Die Ätiologie und Pathogenese dieser komplizierten Klauenerkrankung ist bis heute noch nicht eindeutig geklärt. Eine Vielzahl von Faktoren kann die Klauenlederhaut im Sinne einer Reheentwicklung negativ beeinflussen. In der vorliegenden Arbeit sollte der Einfluss der negativen Energiebilanz nach der Kalbung und eines daraus resultierenden Fettmobilisationssyndroms auf die Entwicklung rehetypischer Anzeichen an den Klauen untersucht werden. Weiterhin sollte geprüft werden, inwieweit die thermographische Untersuchung der Klauen nach der Kalbung, also dem predistinierten Zeitpunkt für die Entwicklung einer Klauenrehe, in der Lage ist, Aufschluss über den Entzündungszustand der Lederhaut zu geben und dementsprechend als frühdiagnostisches Mittel zur Erkennung der subklinischen Klauenrehe Anwendung finden kann. Die Temperaturverteilung über die einzelnen Hauptklauen und die Veränderung dieser im Laufe der Frühlaktation, sowie Unterschiede zwischen primiparen und multiparen Tieren wurde untersucht. Hierfür wurden die Klauen von 123 Kühen und Färsen bzw. Jungkühen aus drei Milchviehanlagen mit ähnlichen Jahresleistungen und verschiedenen Stallböden in der ersten Woche nach der Kalbung, sowie nach Vollendung des zweiten Laktationsmonats bezüglich des Vorliegens einer Lahmheit und, nach der Durchführung einer funktionellen Klauenpflege, auf Anzeichen der subklinischen Klauenrehe durch Vergabe eines Klauenscores untersucht und zusätzlich mittels Thermographie der Fußungsfläche analysiert. Um den Einfluss des Stoffwechsels auf die Reheentwicklung definieren zu können, erfolgten im Zeitraum von 8 Wochen vor der Kalbung bis 8 Wochen nach der Kalbung in regelmäßigen Abständen Messungen der Rückenfettdicke sowie Blutprobenentnahme zur Bestimmung der jeweiligen Freien-Fettsäuren- (FFS), ß-Hydroxybutyrat- (BHB) und Glucosekonzentrationen. Um den Einfluss anderer Stoffwechselentgleisungen abzugrenzen, wurden weiterhin die Parameter Lactat, Gesamtprotein, Albumin, Harnstoff, Calcium, Creatinkinase (CK), Aspartataminotransferase (ASAT) und Lactatdehydrogenase (LDH) bestimmt. Bei der Beurteilung von Lahmheit und Reheanzeichen stellte sich eine signifikante Zunahme letztgenannter nach dem zweiten Laktationsmonat dar. Die Lahmheitsinzidenz nahm dagegen leicht ab. Gummiböden hatten insgesamt einen positiven Effekt auf die Reheentwicklung. Jungkühe wiesen deutlich stärkere rehetypische Veränderungen (Hämorrhagien, Gelbverfärbungen im Horn, weiches Horn) auf als ältere Tiere. Die rehetypischen Veränderungen konzentrierten sich dabei bei allen Probanden auf die hinteren Lateralklauen. Die Thermographie zeigte gravierende Differenzen zwischen den Vorder- und Hintergliedmaßen, sowie zwischen Lateral- und Medialklauen. Die Hinterklauen waren deutlich (p<0,0001) wärmer als die Vorderklauen. Die Lateralklauen der Hintergliedmaßen zeigten sich wärmer als die Medialklauen, während es sich an den Vorderklauen tendenziell umgekehrt verhielt. Im Laktationsverlauf ließ sich eine leichte Zunahme der Differenzen beobachten, wobei sich die Absoluttemperaturen kaum unterschieden. Obwohl die Verteilung von rehetypischen Veränderungen dem Muster der Temperaturverteilung über die Hauptklauen entsprach (hintere Lateralklauen hatten die meisten rehetypischen Veränderungen und die höchsten Temperaturen), konnte keine eindeutige Korrelation zwischen der Klauentemperatur nach der Kalbung und den sichtbaren Reheveränderungen acht Wochen später gefunden werden. Die Temperaturverteilung auf den einzelnen Hauptklauen zeigte in den meisten Fällen (77,3 %) einen um ca. 2-3°C wärmeren Ballenbereich (Rusterholzstelle) im Vergleich zur Klauenspitze. Bei 16,5 % der Klauen waren beide Bereiche gleichwarm (Temperaturunterschied < 1°C) und bei einem geringen Anteil (6,2 %) zeigte sich die Spitze als wärmste Stelle an der Fußungsfläche. Zwischen der Höhe der Rückenfettdicke, der FFS-, BHB- und Glucosekonzentrationen und der Entwicklung einer subklinischen Klauenrehe ergaben sich keine aussagekräftigen Korrelationen. Tendenziell waren eher unterkonditionierte Tiere von Klauenveränderungen betroffen. Schlussfolgerung: Obwohl die Temperaturverteilung auf der Fußungsfläche dem Verteilungsmuster rehetypischer Veränderungen entsprach, war die Thermographie nicht als frühdiagnostisches Mittel zur Erkennung der subklinischen Klauenrehe geeignet. Die Temperaturen zwischen Vorder- und Hinterklauen sowie zwischen Lateral- und Medialklauen unterschieden sich deutlich. Eine direkte Beeinflussung der Klauen durch das Fettmobilisationssyndrom konnte in den hier durchgeführten Untersuchungen nicht gefunden werden.

La conception de machines électriques tend à intégrer l’impact des procédés de fabrication dans le but d’optimiser la conversion d’énergie mécanique en énergie électrique, en lien avec la maîtrise des propriétés électromagnétiques des composants des machines. Les interactions entre procédés, propriétés électromagnétiques et autres propriétés du matériau ont beaucoup été étudiées dans le cas des tôles compte tenu de leur large utilisation dans le domaine de l’électrotechnique et des moyens de caractérisation magnétique normalisés actuels. Cependant, un alternateur à griffes, utilisé dans l’industrie automobile, comporte des composants massifs au rotor pour la conversion mécanique/électrique. Ces composants, appelés roues polaires, sont obtenus par un processus de fabrication comprenant des opérations de forgeage et dont l’impact sur les performances de la machine est encore mal déterminé. Les nouvelles problématiques que pose ce genre de pièces ont mené, dans le cadre des présents travaux, au développement d’une méthodologie spécifique comprenant : l’identification du lien procédés – produit, le développement d’un banc de caractérisation magnétique d’échantillons représentatifs ainsi que la construction de lois de comportement sur des paramètres matériau pertinents à partir de ces échantillons. Les résultats, en accord avec la littérature, ont montré un impact fort de la déformation plastique et de la taille de grain sur les propriétés magnétiques. Cela se traduit, une fois les propriétés modifiées intégrées dans la simulation des performances d’un alternateur, par une baisse significative du courant débité. / The design of electrical machines aims to integrate the impact of the manufacturing process in order to optimize the conversion from mechanical to electrical energy, with the consideration of the electromagnetic properties of the machine components. The interactions between processes, electromagnetic properties and other material properties have been well studied in the case of the steel laminations, regarding their wide use in electrical engineering and the current standards of magnetic characterization devices. However, the claw pole alternator used in automotive industry has a rotor with massive components for the mechanical-to-electrical energy conversion. These components, called claw poles, are manufactured with forging operations whose impact on the machine performance is yet not well determined. The new challenges brought by this kind of work pieces led, in the frame of the current study, to the development of a specific methodology involving: identification of the link process – product, designing of a magnetic characterization device specific for representative samples as well as the establishment of behavior laws regarding relevant material parameters. The results, in accordance with the literature, have shown a strong influence of plastic strain and grain size on magnetic properties. Once these modified properties integrated in the electromagnetic model of the claw pole alternator, a significant decreased of the output current is eventually observed.

Les procédés de fabrication, du fait de leurs imperfections, conduisent à des dispersions des dimensions par rapport au nominal ainsi qu’à une variabilité de celles-ci d’un produit à un autre. Pour les machines électriques, ces imperfections peuvent conduire à des excentricités entre le rotor et le stator ou à des déformations de la surface intérieure du stator (défaut de forme). Dans la littérature, les travaux se focalisent surtout sur l’étude des effets néfastes dus à l’excentricité et pas sur les défauts de forme. De plus, ces travaux sont souvent basés sur une approche déterministe négligeant la variabilité qui peut apparaitre dans le cas de la production de masse. L’objectif de la thèse est donc de mettre en place une méthodologie basée sur une approche probabiliste permettant de quantifier l’effet des imperfections des procédés de fabrication sur la géométrie d’une machine électrique et d’en évaluer l’impact sur les performances. Pour cela, une campagne de mesures dimensionnelles a été effectuée sur 50 machines électriques permettant de caractériser les principaux défauts comme l’excentricité et la déformation de la surface intérieure du stator. Des modèles probabilistes de ces défauts ont été proposés permettant de prendre en compte leur variabilité. L’utilisation d’un modèle numérique de la machine électrique combiné avec des techniques d’approximation creuse ont permis d’évaluer l’influence de ces défauts sur les grandeurs d’intérêt comme la FEM ou le couple. / Due to their imperfections, manufacturing processes lead to deviations on the dimensions which are not equal to their nominal value and as well as a variability on the dimensions from one product to another in the case of mass production. For electrical machines, these imperfections can cause an eccentricity between the rotor and the stator or shape default like the deformation of the inner surface of the stator. In the literature, research focuses mainly on the study of detrimental effects due to the eccentricity but not on shape default. In addition, this research is often based on a deterministic approach neglecting the variability that can arise especially in mass production. The aim of the thesis is to develop a methodology based on a probabilistic approach to quantify on the performances of an electrical machine the effect of imperfections of manufacturing processes on the geometry. First, a campaign of measurements was performed on 50 electrical machines for characterizing the main defaults such as the eccentricity and the deformation of the inner surface of the stator. Probabilistic models of these defaults have been proposed for taking into account their variability. A numerical model of the electrical machine combined with sparse approximation techniques were used to quantify the influence of these defaults on quantities of interest such as EMF or torque.