Hydropower research is often perceived to be an old and exhausted field of study but with ageing equipment and the need for more intermittent operation caused by an increased share of other renewable energy sources new challenges lie ahead. The main focus of this dissertation are the electromagnetic forces resulting from nonuniform air gap flux, whether it be caused by rotor eccentricity or a faulty field winding. Results are predominantly obtained from measurements on an experimental generator and numerical simulations. With the computational capacity available today it is possible to numerically analyse physical phenomena that previously could only be studied with analytical tools. Numerical models can also be expanded to encompass more than one aspect of generator operation in coupled field-circuit models without model complexity surpassing computer capability. Three studies of unbalanced magnetic pull, UMP, in synchronous salient pole generators constitute the main part of this thesis. The first is a study of how parallel stator circuits affect the unbalanced magnetic pull caused by rotor eccentricity. Depending on the relationship between the geometry of the separate circuits and the direction of the eccentricity it was found that parallel circuits could reduce the UMP substantially. Secondly, an investigation of the effect of damper winding configuration on UMP was performed. The results showed that damper winding resistivity and the distance between the damper bars in a pole determine the effectiveness of the damper winding in reducing the UMP. Simulations of a production machine indicate that the reduction can be substantial from damper windings with low resistivity. The third study analyses the consequences of field winding interturn short circuits. Apart from a resulting rotating unbalanced magnetic pull it is found that the unaffected poles with the same polarity as the affected pole experience an increase in flux density. In a fourth article a new stand still frequency response, SSFR, test method including measurements of damper winding voltage and current is presented. It is found that the identified models are capable of predicting the stator to damper transfer function both with and without the damper winding measurements included.

Brushless Direct Current (BLDC) motors are one of the motor types rapidly gaining popularity. BLDC motors are being increasingly used in critical high performance industries such as appliances, automotive, aerospace, consumer, medical, industrial automation equipment and instrumentation. Fault detection and condition monitoring of BLDC machines is therefore assuming a new importance. The objective of this research is to advance the field of rotor and load fault diagnosis in BLDC machines operating in a variety of operating conditions ranging from constant speed to continuous transient operation. This objective is addressed as three parts in this research. The first part experimentally characterizes the effects of rotor faults in the stator current and voltage of the BLDC motor. This helps in better understanding the behavior of rotor defects in BLDC motors. The second part develops methods to detect faults in loads coupled to BLDC motors by monitoring the stator current. As most BLDC applications involve non-stationary operating conditions, the diagnosis of rotor faults in non-stationary conditions forms the third and most important part of this research. Several signal processing techniques are reviewed to analyze non-stationary signals. Three new algorithms are proposed that can track and detect rotor faults in non-stationary or transient current signals.

Stator current spectral analysis techniques are usually used to detect rotor faults in induction machines. Magnetic field anomalies in the airgap due to the rotor faults result in characteristic side-band harmonic components in the stator current spectrum, which can be measured as rotor fault signatures. A position-varying load torque oscillation at multiples of the rotational speed, however, has exactly the same effect. Stator current harmonics due to a load torque oscillation often obscure and even overwhelm rotor eccentricity fault detection since the magnitude of load oscillation induced harmonics is usually much larger. Although previous research has suggested some methods to differentiate between these two effects, most of them rely heavily on the accurate estimation of motor parameters. The objective of this research is to develop a far more practical and computationally efficient method to detect rotor faults effectively in the presence of a load torque oscillation. A significant advantage of the proposed scheme is that it does not need any knowledge of motor parameters. The normalized negative sequence information induced by a mixed rotor eccentricity in the stator current or terminal voltage space vector spectra, serves as a reliable rotor fault indicator to eliminate load oscillation effects. Detailed airgap magnetic field analysis for an eccentric motor is performed and all machine inductance matrices as well as their derivatives are reformulated accordingly. Careful observation of these inductance matrices provides a fundamental understanding of motor operation characteristics under a fault condition. Simulation results based on both induction motor dynamic model and Maxwell 2D Finite Element Model demonstrate clearly the existence of the predicted rotor fault indicator. Extensive experimental results also validate the effectiveness and feasibility of the proposed detection scheme.

Le rire et la mélancolie constituent l'ambiance dominante des romans de Milan Kundera. Ce sont les deux faces de son attitude vis-à-vis du narcissisme de l'homme reflété par ses personnages. Comme Narcisse, l'homme n'est jamais celui pour qui il se prend. Le narrateur présente cette vision kundérienne de l'homme, en racontant le comique et la misère des personnages. Comme le vécu de Kundera se reflète dans les situations des personnages, ce narrateur assume d'un côté une fonction d'autocritique. Mais d'un autre côté, ce narrateur reflète également le romancier, en prenant jusqu'au nom même de Kundera, et présente son image du romancier que croit être Kundera. Ainsi, Kundera lui-même n'est pas non plus hors de l'emprise narcissique. Néanmoins, le roman est le seul espace qui lui permet de méditer sa subjectivité narcissique en la relativisant. Pour Kundera, le roman permet d'échapper momentanément à la condition de Narcisse, grâce au jeu solitaire et sérieux de l'écriture dans les marges de l'hypothèse. / Laughter and melancholy constitute the dominant atmosphere of the novels of Milan Kundera. These are the two faces of his attitude about man’s narcissism and of which his characters are reflections. But man is never the person he thinks he is. Kundera expresses this vision of man through the narrators in his novels, who explore the comic and the miserable aspects of the characters appearing in them. Given the fact that the experience of Kundera is reflected in the characters’ situations, on one hand, the narrator endorses a function of self-criticism. On the other hand, this narrator reflects the novelist, sometimes taking even the name of Kundera himself, and presents his image of the novelist which Kundera believes himself to be. Therefore, Kundera is not free of narcissism. Nevertheless, the novel is the only place that allows him to ponder over his narcissistic subjectivity by the way of relativization. For Kundera, the novel enables him to escape momentarily the condition of Narcissus, by the solitary and serious game of writing in the margins of hypothesis.

Na análise de estruturas é comum a consideração da concentricidade entre vigas e placas. Estudos numéricos em pavimentos de laje nervurada, onde os espaçamentos das vigas são pequenos, mostram que a consideração da excentricidade entre placa e a viga resultam em redução dos deslocamentos na estrutura, entretanto não existem estudos sobre a influência da excentricidade em pavimentos com poucas vigas. Este trabalho apresenta a análise numérica de pavimentos com dimensões usuais considerando ou não a excentricidade com o objetivo de verificar a influência da excentricidade no comportamento da estrutura. As análises mostraram diferenças de deslocamentos e tensões nas estruturas estudadas. O efeito de excentricidade pode ser incluído através da modificação da matriz de rigidez do elemento finito de viga. Todos os pavimentos foram analisados com o software ANSYS com elementos de placa e viga que representassem os modelos do trabalho. / It\'s usual practice on structural analysis of buildings slabs to assume the concentricity between plates and beams. Numerical studies in waffle-slabs, where the distance between beams is small, showed that the eccentricity of beam to plate results in reduction of stresses and displacements of the system, however there is not similar study about the influence of eccentricity in slabs with few beams. This work presents numerical analysis results of at slabs with usual dimensions considering or not plate-beam eccentricity, aiming at evaluating its influence in structural behavior. The analysis showed differences of displacements and stress in studied structures. The effects of eccentricity can be included by modifying the stiffness matrix of the beam finite element. All slabs were analyzed with ANSYS program with suitable beam and plate elements.

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.

Le travail effectué au cours de cette thèse se divise en trois. Pour la première partie, 12 injections de traceurs rétrogrades ont été effectuées chez le macaque cynomolgus à différentes excentricités visuelles de V1, V2, V4 et MT. Nous observons que, si les injections effectuées au sein des territoires correspondant aux représentations centrales (i.e fovéale) de l'hémi-champs visuel reçoivent préférentiellement des projections issues de la voie ventrale, les injections placées au sein des représentations périphériques marques préférentiellement les neurones d'aires connues pour faire partie de la voie dorsale. Les injections excentriques affichent une décroissance exponentielle des poids de connexion avec l'augmentation des distances, comme décrit précédemment (Markov et al. 2014). Ceci plaide en faveur de l'hypothèse que la règle exponentielle de distance (EDR en anglais) (Ercsey-Ravasz et al 2013) est assez puissante pour expliquer la formation des voies fonctionnelles du cortex visuel. De plus, cela suggère fortement que l'EDR s'applique à n'importe quel point du manteau cortical, indépendamment de toutes limites d'aires, et que, par conséquent, le cortex est mieux décrit comme une gradient continu de propriétés progressivement changeantes, au lieu d'une mosaïque de aires corticales bien définies. De plus, cela a de profondes implications concernant l'évolution biologique des aires corticales ainsi que du cortex dans son ensemble. En seconde partie, tractographie et traçage de voies furent comparés, via l'utilisation d'IRM de diffusion. Une analyse en tractographie fut effectuée, et la matrice de connectivité résultante comparée à celle obtenue par traçage de voies (Markov et al., 2014). Les résultats préliminaires de cette thèse tombent dans le même intervalle de succès de détection que les études précédentes : entre 70 et 77 % de la connectivité évaluée par tractographie est correcte (Azadbakht et al 2015, Calabrese et al 2015a, Donahue et al 2016). Cela met également en évidence un problème de spécificité des connexions détectées par la tractographie, qui ne parvient pas à reconnaître les connexions absentes avec précision, un problème particulièrement visible dans le contexte des aires visuelles de bas niveau, chez qui la connectivité est connue pour être très spécifique (Tigges et al 1973, Tigges et al 1974, Martinez-Millan & Hollander 1975, Kaas & Lin 1977, Wong-Riley 1978). En conclusion, les propriétés de connectivité du cortex ne devraient pas, à ce stade, être déduites la tractographie basée sur l'imagerie de diffusion. Pour la dernière partie, 6 injections ont été réalisées chez 3 animaux bilatéralement énucléés (3 dans le « Default Extrastriate Cortex » - DEC ; 1 dans V2 et 2 dans V4) afin d'évaluer comment la connectivité visuelle est affectée par la perte des afférences rétiniennes au thalamus. Comme rapportées antérieurement, des gyri anormaux sont observés sur l'operculum occipital, dont le territoire est dominé par la DEC, un cortex hybride entre cortex strié et extrastrié (Dehay et al 1996a, Dehay et al 1996b). De plus, l'anatomie du LGN est massivement perturbée. Les afférences en provenance du pulvinar et du LGN sont éparses et mal ciblées lors d'injections placées côte-à-côte. La connection du pulvinar au DEC est d'un ordre de grandeur supérieure à une connexion normale du pulvinar à V1, alors que la même comparaison pour le LGN est d'un ordre de grandeur inférieure. Ces changements en matière de connectivité s'amenuisent en allant plus haut au sein de la hiérarchie visuelle corticale. En effet, les changements les plus frappants se produisent dans V1 (aberrant gyri, DEC, ventralisation, etc.) alors que V4 semble être peu perturbé par l'absence d'afférences rétiniennes. Du point de vue du développement du système visuel, cela plaide pour un effet localisé des entrées thalamiques (i.e. seulement V1 et V2) ainsi que pour une absence d'effet domino en cascade compromettant l'ensemble du cerveau / The work performed during this thesis is three fold. In the first part, 12 injections of retrograde tracers were performed in cynomolgus macaques at different visual eccentricities in V1, V2, V4 and MT. We observe that, while injections performed in territories corresponding to the central (i.e. foveal) representation of the visual hemifield preferentially receive inputs from areas belonging to the ventral pathway, injections placed in peripheral representations preferentially labels neurons in areas known to be part of the dorsal pathway. Eccentric injections return an exponential decay of connexion strength with increasing distances, as previously described (Markov et al, 2014). This strongly argues in favour of the Exponential Distance Rule (EDR) being powerful enough to explain the formation of the functional streams of the visual cortex. Firstly, it strongly suggests that the EDR is applicable at any point of the cortical sheet regardless of area boundaries, and that therefore the cortex is better seen as a continuous sheet of gradually changing properties, instead of a mosaic of well-defined cortical areas. Secondly, it helps inform and refine our current definition of an area towards a more comprehensive one which includes topological location. Finally, it has deep implications regarding the evolution of cortical areas as well as the cortex as a whole. In the second part, a comparison was attempted between tractography and tract tracing, with the high definition diffusion MRI scan of one macaque brain. Tractography was computed on it, and the resulting connectivity matrix compared to tract tracing (Markov et al, 2014). The preliminary results obtained in this thesis fall in the same range of detection success than previous studies: between 70 and 77 % of the connectivity assessed by dMRI-based tractography is correct using the same Receiver Operating Charateristic (ROC) approach (Azadbakht et al 2015, Calabrese et al 2015a, Donahue et al 2016). It also highlights a problem of specificity of connexions detected by tractography. It fails to accurately discriminate empty connexions (i.e. absent) as empty, a problem especially salient in the context of early visual areas, the connectivity of which is known to be very specific (Tigges et al 1973, Tigges et al 1974, Martinez-Millan & Hollander 1975, Kaas & Lin 1977, Wong-Riley 1978). Overall, caution is for now warranted and connectivity properties should not at this point be inferred on diffusion MRI based tractography. In the last part, 6 injections were performed in 3 bilaterally enucleated animals (3 in the Default Extrastriate Cortex - DEC, 1 in V2 and 2 in V4) in order to assess how the visual connectivity is impacted by the loss of retinal inputs to the thalamus. As previously reported, abnormal gyri are observed on the operculum, whose territory is now dominated by the DEC, a hybrid cortex combining histological and histochemical feature of striate and exstrastiate cortex (Dehay et al 1996a, Dehay et al 1996b). Also, the LGN anatomy is massively perturbed, losing its heterogeneity of strictly defined layers for a homogeneous structure. Inputs from the pulvinar and the LGN were found to be unfocused, scattered and unsegregated in side-by-side injections. The pulvinar input to the DEC was found to be an order of magnitude higher than a normal pulvinar-to-V1 connexion, when the same comparison for the LGN was found to be an order of magnitude lower. These changes in connectivity appear to diminish in importance as one goes up the visual hierarchy. Indeed the most striking changes are in V1 (aberrant gyri, DEC, ventralisation, etc.) whereas V4 appears to be seemingly unperturbed by the absence of retinal inputs. Regarding the development of the visual system, this fact argues for a localised effect of the thalamic inputs (i.e. only V1 and V2) and an absence of domino-effect cascade that would perturb the entirety of the brain, despite the quite drastic enucleation process

L'œuvre d’Amelia Rosselli entend se dessiner, au sein de la poésie lyrique italienne, comme expérience de subversion du processus de sublimation et de stylisation du corps féminin. A travers la traduction et l’analyse de poèmes choisis contenus dans les recueil Cantilena (1953), La Libellula (1958) et Variazioni belliche (1964), nous avons conduit une tentative d’exégèse critique des textes. L’analyse des poèmes se poursuit à travers une pratique dialogique avec le texte poétique, à partir d'un positionnement critique à l’intérieur du comparatisme féministe.En partant de l'idée pétrarquiste d'élimination et de suppression du corps des femmes nous avons démontré comment la tentative d’apaiser la portée potentiellement dangereuse de l’affection amoureuse a donné lieu au déni de la sensualité. Le langage de la douleur transfigurée se traduit dans une poétique du « dispositif sursensuel », un processus semblable à celui que Gilles Deleuze avait repéré dans la personnalité littéraire de Sacher-Masoch. Le processus de subversion qu’on vient d’évoquer est accompagné du bouleversement des rôles traditionnels au sein du canon poétique européen. Ces déconstructions conduiraient à un rejet du corps organique et au même temps à la révélation d’une subjectivité excentrique. La révision des modèles littéraires du canon passe également par le réécriture d'un ensemble de figures féminines du répertoire mythique et littéraire au sein de l’antiquité gréco-romaine, lesquelles, prélevées de l’imaginaire patriarcal, sont réinterprétées et à nouveau poétisées au sein d'un Sujet poétique qui cherche à faire parler la voix d’une poète femme. / Amelia Rosselli’s work took shape, within Italian lyric poetry, as an experience of subversion of the process of sublimation and of stylisation of the female body. Through the translation and the analysis of the content of poems chosen from the collections Cantilena (1953), La Libellula (1958) and Variazioni belliche (1964), I conducted a critical exegesis of the texts. I performed an analysis according to suggestions of a dialogical practice with the poetical text and with a female subjectivity often hidden, anchored to my critical investment inside feminist comparatism. From petrarchist idea of deletion and “suppression” of women’s body – deletion, of which Pasolini talked already in relation to the genesis of Italian poetry and its characterisation of the lyrical canon – I analysed how the attempt to ease the impact potentially dangerous of love affection has caused the denial of sensuality. The language of camouflaged sorrow is then established as a deliberated choice included in some poetics where it is not the statement that reveals, but the poetical word, which in its cryptic canonical measure, is able to make resonate beyond declarations. We can observe the deployment of a “sursensual device”, similar process to what Gilles Deleuze perceived in Sacher-Masoch's literary personality. The process of subversion does not seem a reconstitution of identity roles, but rather a deconstruction of the traditional model. The starting point for the analysis of those deconstructions is based on the hypothesis that the non-functionality of the desiring organisms (desiring subject and desired object) will lead to a reject of the organic and at the same time to a revelation of an eccentric subjectivity. The revision of the literary model of the canon lies in the hypothesis that a set of female figures of the mythical and literary repertoire in Greco-Roman antiquity are placed in the imaginary practice of Amelia Rosselli's poetical writing, with a view to incorporate the nature of the characters born and conceived inside and by the patriarchal imaginary and to form the body of a subject that aims at making them speak through the voice of a female poet.

This thesis deals with the hydrodynamic plain bearings tractor diesel engine. The first part is closer acquainted with the hydrodynamic bearing, its principles and materials used. The next part work deals with the multibody system adams-engine. The main part of this work is to model the crank mechanism and its storage in hydrodynamic bearings in the MBS program and the subsequent simulation under different operating conditions.

The aim of this thesis is to find out the influence of eccentricity of crank mechanism on the duration of the force between the piston and the cylinder liner. At the same time I wanted to find out its influence on the balance of the whole system. It is important to design the balance for the selected value of the eccentricity and subsequently put through the crank shaft to stress analysis with torsional vibrations. I got so interested in this problem that in addition to the whole topic I designed a torsional vibration damper.