Thesis advisor: Stephen F. Brown / The purpose of this dissertation is to provide a systematic account of St. Bonaventure of Bagnoregio’s doctrine of grace. More particularly, the dissertation argues that a systematic account of this kind can only be provided by attending to that doctrine through his theology of hierarchy, a methodology that derives from the Seraphic Doctor’s own claim in the Legenda Maior that St. Francis was a vir hierarchicus, or a “hierarchical man.” Throughout the course of his theological career, the Seraphic Doctor defines sanctifying grace as a created influentia that “hierarchizes” human beings by purifying, illuminating, and perfecting them from within, thus causing them to become a “similitude” of the Trinity. This dissertation explains what this means and why it matters. Methodologically, the dissertation proceeds in three parts. Part I, “Theological Foundations for Bonaventure’s Doctrine of Grace,” lays the necessary groundwork for the rest of the project in two ways: first, by introducing three historical figures whose work will provide indispensible theological contexts for approaching Bonaventure’s doctrine of grace, namely, Pseudo-Dionysius, Thomas Gallus, and Alexander of Hales; and second, by introducing the Seraphic Doctor’s own theology of hierarchy as he inherited it from these sources. Part II, “Bonaventure’s Doctrine of Grace,” then builds upon these foundations to present a systematic account of that doctrine as it developed in some of his most important works throughout his career as a theologian. Part III, “Theological Implications of Bonaventure’s Doctrine of Grace,” concludes the dissertation by exploring how that doctrine can inform scholarship on Bonaventure’s theological anthropology, Christology, and theology of sanctity, respectively. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Theology.

As the demand for oil and gas resources increases, the need to venture into more hostile environments becomes a dynamic focus in the petroleum industry. One problem associated with certain high risk formations is lost circulation. As a result, engineers have concentrated research efforts on developing novel Lost Circulation Materials (LCM’s) that will effectively treat thief zones. The most pioneering LCM’s require mixing energy to activate a reaction involving two or more chemicals. However, minimal research has been conducted to accurately predict downhole mixing capabilities. Therefore, this research focuses on developing a correlation between laboratory experiments and scaled model experiments for accurate prediction of downhole mixing energies in terms of flow rate for adequate mixing of lost circulation prevention fluids.

Reproduction de : Thèse de doctorat : Dynamique des fluides : Toulouse, INPT : 2006. / Titre provenant de l'écran-titre. Bibliogr. 219 réf.

Thèse doctorat : Acoustique : Villeurbanne, INSA : 2005. / Titre provenant de l'écran-titre. Bibliogr. p. 145-153.

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Dimensional Analysis is a technique that has allowed engineering evaluation of complex objects by scaling analysis results of representative simpler models. The original premise of the procedure stems from the idea of developing non-dimensional parameters to relate physical events and underlying analytical basis. Extending the process to incorporate non-linear and time variant behavior has led to development of a novel process of similitude called the Empirical Similitude Method (ESM) where experimental data of test specimen is combined to produce the required prediction values. Using the original motivation and hypothesis of ESM, this research has expanded the experimental similitude process by using adapted matrix representations and continuous functional mapping of test results. This new approach has provided more rigorous mathematical definitions for similarity and prediction estimations based on an innovative error minimization algorithm. Shape factors are also introduced and integrated into ESM to obtain comprehensive evaluation of specimen choices. A detailed overview is provided summarizing methods, principles and laws of traditional similitude (TSM) and systems that satisfy extension into ESM. Applicability of ESM in different systems is described based on the limitations of TSM in the evaluation of complex structures. Several examples and ideas spanning aerodynamic, thermal, mechanical and electro-magnetic domains are illustrated to complement inherent technical analysis. For example, the new ESM procedure is shown to be considerably more accurate than earlier methods in predicting the values of drag coefficient of an airfoil. A final foray into the regime of \design evaluation by similarity" is made to elucidate applicability and efficiency of developed techniques in practical systems and products. A thorough methodology is also presented highlighting pertinent procedures and processes in usage of this method. / text

The aim of this thesis is to develop a test facility in order to validate the safe separation of a store model from the aircraft model with the analysis of the acquired data. Different alternatives are considered in the conceptual design and a facility is selected which contains the rail constructed 5 meters above the ground. 300 meter test range is used to accelerate the aircraft model, attached to the carriage with solid rocket engines. The concept is to accelerate the carriage within the first 100 meters, to perform the separation of the model at the desired velocity when the rocket engine is burned out, and in the last 100 meters, to decelerate the carriage in order to recover the models. After the parts of the carriage are designed with respect to the requirements of the separation and completing the similitude study of scaled models with the ratio of 1/8, separation tests are performed. These tests are constrained with 0.9 Mach due to the store and test aircraft limitations. Doppler radar is issued to measure the velocity and photogrammetry method is used to validate and analyze the separation and to obtain the vertical trajectory of the store model. Measured trajectory of the store model is compared with the trajectory of the full scale store.

Commercial ebullated bed hydroprocessors, such as the LC-Finer, are used for the production of synthetic crude oil by upgrading bitumen extracted from the Alberta oil sands. The objective of this thesis was to investigate the impact of an increased vacuum distillation tower bottoms feed fraction on the reactor fluid dynamics (e.g., bed and freeboard phase holdups, bubble characteristics and local fluidization behaviour). Industrial conditions were simulated in a high pressure gas-liquid-solid fluidization system based on dimensional and geometric similitude. Considering important geometric characteristics and matching dimensionless groups, base-case conditions resulted in an ebullated bed of nitrogen, 0.5 wt.% aqueous ethanol, and aluminum cylinders (average lengths and diameters of 7.5 and 3.2 mm, respectively) operating at 6.5 MPa and a gas-to-liquid superficial velocity ratio of 0.78. The proposed scale-down method resulted in high gas holdup conditions similar to industrial measurements. The use of the Sauter mean diameter to account for particle size and shape at the simulation conditions was investigated by comparing glass spheres with diameters of 4 and 1.5 mm to aluminum cylinders with equivalent volume-to-surface area ratios. Local bubble characteristics, including gas holdups, bubble rise velocities, and chord lengths, were then investigated under various operating conditions using a monofibre optical probe. Overall fluid dynamics were studied when increasing the liquid viscosity and varying the gas and liquid superficial velocities due to their relevance for industrial ebullated bed hydroprocessors. Freeboard and bed region gas holdup relations were studied and correlations were developed for gas and solid holdups at the simulation conditions based on the dimensionless groups. Mesophase generation in hydroprocessors due to undesired secondary reactions was also considered for an increased vacuum residue feed fraction. Adding a dispersed immiscible liquid phase which preferentially wetted the particles was therefore experimentally studied at non-simulating conditions using nitrogen, biodiesel, glycerol and various particles, where fluidization behaviour and phase holdups were considerably affected due to particle clustering. A study on the impacts of particle size, shape and material demonstrated the influences of fluid and particle properties, specifically the relative surface energies and viscous forces, on agglomeration due to interparticle liquid bridging.

Cette thèse a été réalisée en collaboration avec la société SCLE SFE (Groupe ENGIE) et le laboratoire Laplace. Elle porte sur le développement d’une méthodologie permettant d’élaborer des modèles dits « en similitude », à échelle de puissance et de temps réduites. Ces modèles peuvent servir pour l’analyse des systèmes mais ils sont en particulier utiles pour l’expérimentation en temps réel des systèmes énergétiques. En effet, les expérimentations sont très souvent menées à échelle réduite pour des questions de taille, de coût,… Certaines parties de ces expérimentations peuvent être « émulées » (simulées physiquement par des dispositifs de puissance) d’autres étant constitués de composants physiques : on parle alors de procédure Hardware in the Loop (HIL). Même si, à la base, la démarche de réduction d’échelle a une portée générale, notre gamme d’application principale concerne les micro réseaux avec intégration de sources renouvelables intermittentes couplées à des composants de stockage. En conséquence,nos travaux se focalisent sur la mise en œuvre de modèles de similitudes en puissance/énergie/temps de sources ENR et de stockeurs. La notion de réduction de temps, nous parlerons de « temps virtuel compacté », est un des concepts clés de ces travaux. Une attention particulière est portée sur le développement d’un émulateur physique de batterie électrochimique.En effet, le stockage d’énergie est un point clé dans un micro réseau. De plus, cet élément présente de fortes non-linéarités dont la mise en similitude doit impérativement tenir compte et n’est pas triviale. Une fois ces modèles développés, on les éprouve via la mise en œuvre d’essais en expérimentation simulée par émulateurs physiques à échelle de puissance réduite et en temps virtuel compacté. Ces essais permettent par ailleurs de confronter les notions d’émulateurs «copie-modèle », pour lequel un modèle est utilisé pour reproduire le comportement du système, et d’émulateurs « copie-image », où le comportement du système est reproduit à partir d’un de ses composants réels (par exemple une cellule pour la batterie). / This thesis was carried out in collaboration with SCLE SFE (ENGIE Group) and the Laplacelaboratory. It focuses on the establishment of a methodology allowing the “similarity” modelsdevelopment, with reduced power and time scale. These models can be used for systems analysisbut they are particularly useful for real-time experimentation of energy systems. Indeed, theexperiments are often carried out on a small scale for issues of size, cost, … Some parts of theseexperiments can be "emulated" (physically simulated by power devices) while others consist ofphysical components: this is called the Hardware in the Loop (HIL) procedure. Although, initially,the downscaling approach is broad in scope, our main field of application is microgrids withintegration of intermittent renewable sources coupled with storage components. As a result, ourwork focuses on the implementation of power / energy / time similarity models of ENR sources andstorage facilities. The concept of time reduction, we will talk about "compacted virtual time", is oneof the key concepts of this work. Particular attention is paid to the development of a physicalemulator of electrochemical battery. Indeed, energy storage is a key point in microgrid. In addition,this element has strong nonlinearities whose scaling in similarity must imperatively take intoaccount and is not trivial. Once these models have been developed, they are tested through theimplementation of simulated experiments using physical emulators with reduced power scale andcompacted virtual time. These tests also make it possible to compare the concepts of "copymodel" emulators, for which a model is used to reproduce the behavior of the system, and "copyimage" emulators, where the behavior of the system is reproduced from of one of its realcomponents (for example a cell for the battery).

Cette thèse porte sur le problème du ballottement d'un liquide dans un réservoir, rencontré dans le transport et le stockage du GNL par des structures flottantes. La prédiction des chargements réels, dus au ballotement sur les parois du réservoir, est souvent basée sur des études expérimentales à petite échelle. La modélisation expérimentale à petite échelle respecte la similitude de Froude et le rapport de densité entre le gaz et le liquide. Cependant, d’autres similitudes sont biaisées comme la similitude par rapport au nombre de Weber et la similitude par rapport au nombre de Reynolds. De plus, les pressions enregistrées montrent une grande variabilité quand le même essai est répété. Dans une première partie, différentes sources physiques responsables de cette variabilité sont discutées, à savoir les instabilités de surface libre, la retombée des gouttes et des jets liquides sur la surface libre, et la production et l'entraînement des bulles dans le liquide. En fait, ces phénomènes sont à l'origine des perturbations de l'écoulement, de la variabilité de la géométrie de la vague et de cette façon des pressions engendrées par cette dernière sur la paroi. D'autres mécanismes de dissipation d’énergie sont identifiés. Ils sont liés aux frottements aux parois et aux déferlements de vagues. Nous montrons que cette dissipation induit un effet mémoire à courte durée pour l’écoulement, permettant de reproduire pour chaque impact la distribution statistique des pics de pression avec une courte durée des excitations. Ces sources de variabilité et ces mécanismes de dissipation dépendent de la tension de surface et de la viscosité du liquide. Ainsi nous étudions dans une deuxième partie, les effets de ces paramètres physiques. Nous montrons que la forme locale de la vague dépend de la tension de surface. Par contre, les effets sur la forme globale de la vague sont négligeables. Plus la tension de surface diminue, plus les pics pression sont faibles. Ce qui est dû aux différents phénomènes liés au développement des ligaments, la fragmentation en gouttes et la génération de la mousse sur la crête de la vague, et à l’entraînement des bulles dans le liquide. Quant à la viscosité du liquide, elle affecte à la fois la forme globale et la forme locale de la vague, là encore les pressions sont modifiées. Cette étude paramétrique permet, dans une troisième partie, d'étudier et comprendre les effets du nombre de Weber et du nombre de Reynolds, en comparant les résultats pour deux échelles différentes 1:40 et 1:20, quand les mêmes fluides sont considérés. De plus, en se basant sur différents cas de comparaison avec la similitude de Reynolds et/ou la similitude de Weber, nous montrons que la double similitude est indispensable pour obtenir une forme de vague avant l'impact indépendante de l'échelle. Cependant, la distribution statistique des pics de pression dépend aussi d’autres nombres adimensionnels à savoir le nombre de Mach du liquide et le nombre de Mach du gaz. / This work focuses on sloshing problem, encountered in the transport and storage of LNG by floating structures. The prediction of real sloshing loads is often based on small-scale experimental studies, respecting the Froude similarity and the density ratio between the gas and the liquid. However, other similarities are biased such as the Weber similarity and the Reynolds similarity. In addition, the recorded pressures show great variability when the same test is repeated. In a first part, different physical sources responsible for this variability are discussed, which are the free surface instabilities, the falling droplets and liquid jets impinging on the free surface, and the liquid entrainment by bubbles. In fact, these phenomena are at the origin of the flow disturbances, the variability of the wave shape, and hence its pressures on the wall. Other dissipation mechanisms are identified. They are related to wall frictions and breaking waves. Thanks to this energy dissipation, we show that the flow is characterized by a short-term memory, making it possible to reproduce for each impact its statistical distribution of pressure peaks with a short duration of excitations. These sources of variability and dissipation mechanisms depend on the surface tension and the viscosity of the liquid. Thus, we study, in a second part, these physical parameters. We show that the local wave shape depends on the surface tension. However, its effects on the global wave shape are negligible. Besides, when the surface tension is reduced, the statistical pressures are reduced. This is due to various phenomena related to the development of liquid ligaments, their fragmentation into drops and the generation of foam at the wave crest, and the liquid entrainment by bubbles. As for the viscosity of the liquid, it affects both the local and global shape wave shapes, again the pressures are changed. Based on this parametric study, The effects of Weber number and Reynolds number are studied by comparing the results for two different scales 1:40 and 1:20, when the same fluids are used. Moreover, considering different cases of comparison with Reynolds number similarity and / or Weber number similarity, the results show that both similarities are essential to obtain a scaleindependent wave shape. However, the statistical distribution of pressure peaks also depends on other dimensionless numbers, namely the Mach number of the liquid and the Mach number of the gas.