[pt] A perfuração de poços de petróleo, principalmente em ambientes offshore, é uma operação que demanda um custo muito elevado, portanto a minimização de problemas e danos ao reservatório produtor é muito importante. O projeto de um fluido de perfuração que garanta a mínima invasão na rocha reservatório é um tópico fundamental, como consequência a indústria petrolífera tem investido em estudos com o intuito de evitar que este problema ocorra. Sendo assim, nesse trabalho estudou-se o escoamento de fluidos em um meio poroso ideal, a célula de Hele-Shaw. Para realizar esse trabalho foram utilizados dois fluidos não newtonianos: uma solução aquosa de um polímero flexível, a poliacrilamida; e uma solução aquosa de um polímero rígido, a goma xantana. Esses fluidos não newtonianos representaram o fluido de perfuração, já o papel do petróleo presente na rocha reservatório foi desempenhado pelo óleo mineral. A partir desse experimento é possível observar a instabilidade de Saffman-Taylor ou viscous fingers, que é um fenômeno observado quando um fluido de menor viscosidade desloca outro de maior viscosidade. Esse fenômeno é muito importante em diversas aplicações, tais como: invasão de fluido de perfuração em meios porosos (caso que será estudado), recuperação secundária e terciária de petróleo, fraturamento hidráulico, processamento de polímeros, hidrologia e filtração. O experimento consiste em analisar a evolução da interface entre os dois fluidos através de uma câmera filmadora. A partir das imagens é determinada qualitativamente a eficiência do deslocamento. Com o conjunto de imagens é possível observar também em quais parâmetros dinâmicos e reológicos ocorre a transição fingers (interface instável) para plug (interface estável), e viceversa. Também foram realizados testes reológicos nos quais foi possível conhecer o comportamento dos fluidos não newtonianos utilizados. Com base nos dados coletados observou-se que tanto para a poliacrilamida quanto para a goma xantana a transição ocorre a uma taxa de cisalhamento adimensional próxima de 3. / [en] The drilling of oil wells, particularly in offshore environments, is an operation which demands a high cost, thus, the minimization of problems and damage to the producing reservoir is very important. The design of a drilling fluid that ensures minimum invasion into the reservoir rock is a major topic, consequently the oil industry has invested in research in order to prevent this problem from occurring. Therefore, this research studied the displacement of fluids in an ideal porous medium, a Hele-Shaw cell. To accomplish this task, the following two non-Newtonian fluids were used: an aqueous solution of a flexible polymer, polyacrylamide; and the other an aqueous solution of a rigid polymer, xanthan gum. Such non-Newtonian fluids represent the drilling fluid, while the function of oil present in the reservoir rock was represented by mineral oil. From this experiment it is possible to observe the Saffman-Taylor instability or viscous fingers, which is a phenomenon observed when a low viscosity fluid displaces a higher viscosity fluid. This phenomenon is very important in many applications, such as drilling fluid invasion in porous media, secondary and tertiary oil recovery, hydraulic fracturing, polymer processing, hydrology and filtration. The experiment consists in analyzing the evolution of the interface between two fluids through a digital camera, and determining the displacement efficiency qualitatively from the imagens. With the set of images is possible to observe in which dynamic and rheological parameters the transition from fingers (unstable interface) to plug (stable interface) occurs, and vice versa. Also, rheological tests were performed in which it was possible to know the behavior of non-Newtonian fluids used in the study. From the data collected it was observed that both the polyacrylamide and for xanthan gum transition occurs near the dimensionless shear rate of 3.

Dans cette thèse, nous avons étudié expérimentalement, numériquement et théoriquement la sédimentation d’un soluté en cellule de Hele-Shaw, modèle analogue de milieu poreux, avec un écoulement zonal horizontal. Une cellule, alimentée par deux grands réservoirs assurant un écoulement zonal uniforme, a été réalisée au laboratoire. La vitesse a été mesurée par PIV. L’injection d’une solution saline dans cet écoulement permet de visualiser la propagation du panache de pollution, et de mesurer le champ de concentration par LIF. Trois configurations typiques ont été observées : panache sans digitation (« stable »), avec une seule digitation (« faiblement instable »), et avec de nombreuses digitations (« fortement instable »). L’influence du contraste de densité, de la vitesse zonale, et du débit d’injection sur la stabilité du panache a été analysée. Ces résultats ont été comparés à des simulations numériques sous COMSOL Multiphysics®. Les champs de concentration simulés sont en accord quantitatif avec les champs expérimentaux. Ces simulations ont de plus permis d’étudier l’influence de l’anisotropie du tenseur de dispersion sur la stabilité du panache. Une étude théorique linéaire, effectuée à partir d’un écoulement de base unidirectionnel et quasi-stationnaire, est venue compléter ces résultats. Elle montre que le panache est toujours convectivement instable pour les valeurs des paramètres considérées, et permet de retrouver et de quantifier les principaux résultats mis en évidence lors des études expérimentale et numérique, comme l’effet stabilisant de la dispersivité longitudinale ou l’effet déstabilisant du contraste de densité / This thesis is an experimental and numerical investigation of solute transport and sedimentation in a Hele-Shaw cell with zonal flow. A vertical cell joining two large tanks has been built to provide a uniform horizontal flow, the velocity of which has been measured by using PIV. The concentration field of a solute injected in this flow has been measured by using LIF. Three typical plume configurations have been observed: without digitations (“stable”), with a single digitation (“weakly unstable”), and with various digitations appearing at the lower interface (“unstable plume”). The influence of density contrast, zonal flow and solute flow rate on the appearance of the various configurations has been investigated. These results have been compared to numerical simulations using the COMSOL Multiphysics® software. The numerical concentration fields are in qualitative agreement with the experimental ones. In addition, these simulations allowed us to investigate the effect of the anisotropy of the dispersion tensor on the occurrence of unstable configurations. A linear stability analysis based on a uniform parallel flow superposed to a quasi-steady horizontal layer of solute has been performed. It shows that the plume is convectively unstable for the parameters considered here, and confirms the various behaviors observed in both the experimental and the numerical analyses, like the stabilizing effect of the longitudinal dispersivity or the destabilizing effect of the solute concentration

Die musiktheoretische Analyse setzt die Musik Bartóks mit der Beirachs und Shaws in Beziehung und fragt nach Schnittstellen in der Musik der drei Komponisten.

[pt] Uma abordagem experimental foi utilizada para o estudo da eficiência de varredura de fluidos viscoplásticos na célula de Hele-Shaw , que representa um meio poroso com porosidade constante. A análise baseia-se em um fluido empurrando outro onde, pela razão de viscosidades acima do punto de referência , manifesta-se a instabilidade de Saffman-Taylor, que desencadeia em uma interface instável com divisões sucessivas conhecidas como viscous fingers. A formação da instabilidade é considerada uma condição indesejável, e no caso da indústria petrolífera, torna-se de interesse na invasão da formação pelo fluido de perfuração, pasta de cimento, e no deslocamento de petróleo pesado em reservatórios entre outros. Apesar de que o fenômeno é vastamente estudado utilizando a célula de Hele-Shaw, a maioria dos trabalhos concentram-se no deslocamento de líquidos newtonianos por ar, deixando uma ampla gama de possibilidades de estudo, particularmente no que diz respeito aos fluidos não newtonianos. Utilizando equipamentos que permitem assegurar uma vazão constante de injeção, testou-se três concentrações diferentes de solução aquosa de carbopol em duas configurações diferentes onde o líquido viscoplástico é o deslocador e vice-versa. Fazendo uso do processamento digital de imagens, avaliou-se a forma da interface em função do desvio padrão, além da velocidade e da eficiência de varredura no deslocamento. Determinaram-se parâmetros adimensionais em função da geometria da bancada e dos fatores dinâmicos e reológicos dos fluidos onde se obtiveram duas zonas vem marcadas de varredura. Observou-se que a razão de viscosidades e o número de capilaridade modificada crítica são os indicadores que governam o deslocamento. / [en] An experimental approach has been used to study the sweep efficiency of viscoplastic fluid in a Hele-Shaw cell, which represents a porous medium with constant porosity. The analysis is based on a lower viscosity fluid pushing a more viscous through a geometry, which manifests the instability of Saffman-Taylor, that result in an unstable interface with successive divisions known as viscous fingers. The occurrence of instability is considered an undesirable condition, and in the petroleum oil industry, it becomes of interest in the reservoir oil invasion and heavy oil displacement in reservoirs. Despite being widely studied, most studies focus on the displacement of Newtonian liquids by air, leaving the field of study of non-Newtonian fluids without being evaluated where none of viscosities of the fluids involved can be considered negligible. Using equipment that ensures a constant flow rate of injection three different aqueous concentrations of carbopol were tested in two different configurations: carbopol as the displacing fluid and vice-versa. Using digital image processing, the shape interface was evaluated according to their standard deviation, average velocity and efficiency sweep during the displacement. Determined dimensionless parameters was evaluated in function of the experimental geometry, dynamic and rheological factors of the fluids in order to get benchmark that allow separating interfaces zones that tend to 100 per cent or plugs and the zone where the viscous fingers reveal themselves. It was found that the viscosity ratio and modified critical capillary govern the displacement.

This thesis analyses artefacts belonging to the playwright, socialist and critic Bernard Shaw, which form part of the collections at Shaw’s Corner, Hertfordshire, now managed as a National Trust property. My original contribution to knowledge is made by revealing Shaw through the artefacts in new or under-explored roles as socialist-aesthete, art patron, connoisseur, photographer, celebrity, dandy, and self-commemorator. The thesis therefore challenges the stereotypical views expressed in the literature which have tended to focus on Shaw at Shaw’s Corner as a Fabian with ascetic characteristics. The thesis aims are achieved by contextualizing the Shaw’s Corner Collections, both extant and absent. Historically the artefacts in the house have been viewed from the perspective of his socialist politics, ignoring his connoisseurial interests and self-fashioning. Hence there was a failure to see the ways in which these elements of his consuming personality overlapped or were in conflict. By examining artefacts from the perspectives of art and design history, focussing on furniture, private press books, clothing, painting and sculpture, Shaw is shown to be a highly complex and at times contradictory figure. The discontinuities and ambiguities become clearer once we examine the possessions from the house which were removed and sold by the National Trust after Shaw’s death. Whilst some Shavian scholars and art historians have acknowledged Shaw’s role as an art critic and the impact it had on his dramaturgy, there has been little recognition of the ways in which this influenced his domestic interiors, consumption, and personal taste, or indeed his interest in the decorative arts and design. Artefacts and furniture in the house today reflect Shaw’s role as a socialist-aesthete, and his involvement with Arts and Crafts movement practitioners and Aestheticism. As an art patron Shaw also shared the aims of artists, connoisseurs and curators working in the first decades of the twentieth century, and we see evidence of this through certain artefacts at Shaw’s Corner. With a strong aesthetic sense, he devoted time to matters of beauty and art, but was equally governed by economics and a desire to bring ‘good’ art and design to everyone. Shaw was considered to be one of the greatest cultural commentators and thinkers of his generation, but he was at the same time a renowned celebrity and influential figure in the mass media. The literature has tended to dismiss the latter role in order to preserve his place among the former, but I argue here that Shaw did not necessarily view the two as separate endeavours. In fact items from the house, notably Shaw’s clothing and sculpture, are considered as the bearers of complex philosophical, symbolic or iconographic meanings relating to his self-fashioning, aesthetic doctrines, and desire for commemoration, which demonstrate the links between the celebrity and the critic. By considering the artefacts in conjunction with the Trust’s archive of Shaw photographs, as well as his representation in popular culture, and by then relating this material dimension to his writings, the thesis brings a new methodological approach to the study of Shaw. More importantly this thesis reveals new knowledge about the philosophical ideas, humanity, generosity, and personal vanity of the man that lay behind those artefacts.

Partita for 8 Voices (2012) is a groundbreaking a cappella work that earned its composer, Caroline Shaw, the record of youngest recipient of the Pulitzer Prize for Music in 2013. While the work continues to receive performances from its premiere ensemble, Roomful of Teeth, no transcription of the piece to any other ensemble type existed at the beginning of this DMA project. The author sought to transcribe a piece by a living female composer with no work for band into the wind band medium. The resulting transcription, Partita for 8 Voices & Wind Ensemble, adds a new work to the repertoire of band literature that includes new, esoteric, and proprietary extended technique for wind and percussion instruments. The purposes of this DMA project are 1) to provide a brief analysis of Partita for 8 Voices, 2) to provide details of the trials, errors, and successes during the transcription process of Partita for 8 Voices & Wind Ensemble as well as recommendations for future conductors of the work, and 3) to provide anecdotal evidence of the important relationship conductors build with composer intent by embarking on a transcription process. The first chapter includes a biography of Caroline Shaw, the vocal ensemble Roomful of Teeth, and a timeline of Shaw’s compositional process regarding Partita for 8 Voices. The second chapter is a brief theoretical, timbral, and technical analysis of Partita for 8 Voices. Chapters three through seven discuss the transcriptional process and conductor’s insights for each of the four movements of Partita for 8 Voices & Wind Ensemble and general considerations. Chapter eight discusses anecdotal evidence of what conductors learn from the transcription process. An appendix of information including interviews, a graphical analysis of technical and timbral events in Partita for 8 Voices, and the full score for Partita for 8 Voices & Wind Ensemble is also provided.

George Bernard Shaw exercised an above-average level of authorial control, which even extended to his relationship with his biographers. Shaw crafts a persona, with the help of his "authorized" biographer Archibald Henderson, which displays a process of evolutionary development and progress along the lines of the Shavian philosophy of the Life Force and the Superman. In essence, Shaw is casting himself as a prototype for the Superman through the autobiographical manipulation of his biographers and aesthetic modes of self-fashioning.

Pour des mousses 2D(et 3D sphériques) sèches à l'équilibre nous montrons une équivalence étoile-triangle. Cette équivalence affirme que chaque bulle ayant trois bulles voisines peut être considérée comme une décoration des prolongements des côtés externes qui la rejoignent. Cette propriété, déjà connue dans une des ses applications, nous la démontrons en utilisant des méthodes de dualisation, de géométrie projective et l'invariance des mousses 2D par homographies. Plus en général, nous prouvons l'invariance par transformations conformes des mousses 2D. En considérant des mousses en incidence normale sur une paroi, nous avons montré comment les lois d'équilibre en 3D impliquent celles en 2D sur la surface de contact. Ces lois nous permettent d'étudier théoriquement les récentes expériences où une mousse monodisperse est mise entre deux plaques de verre courbes non parallèles. Dans la limite de petit interstice, nous relions le profil à l'application conforme observée expérimentalement. La contribution de la courbure des films dans la direction orthogonale aux plaques est décisive pour corriger des prédictions erronées de la géométrie 2D.

La problématique de ce mémoire s'ancre dans notre contexte actuel, caractérisé par un double mouvement de sécularisation de la sphère sociale et de « réenchantement » ou de « resacralisation » dans les sphères artistique, culturelle et intellectuelle. Partant de cette dichotomie singulière, ce projet de recherche constitue une tentative d'élucider ce rapport complexe entre l'art actuel - immergé dans le nihilisme de la postmodernité - et une forme hybride et non définie de sacré. Face à l'ampleur d'une telle question et à l'éclectisme de son sujet, ce mémoire se resserre autour de la volonté de donner un sens à cet éclatement à travers le développement d'une notion originale, celle d'incarnation tautologique. Pivotant sur un renversement nihiliste du dogme de l'incarnation, cette idée – outil conceptuel plutôt que concept – restructure le sacré en dehors de la présence d'un Dieu, faisant alors de cette perte de la transcendance l'occasion de réfléchir le sacré sous un jour totalement humain. L'ensemble de ce mémoire est ainsi consacré à la précision de cet outil théorique. L'objectif n'étant ni de faire système au sein de l'hétérogénéité actuelle ni d'établir une typologie du champ artistique, ce mémoire se penche sur l'étude d'un même thème, celui du paradis terrestre, tel que repris par trois œuvres contemporaines dont les analyses ont pour but de préciser la teneur théorique de cette incarnation tautologique. Ces trois œuvres - soit Garden (Marc Quinn 2000), Garden of Earthly Delights III (Raqib Shaw 2003) et Au commencement 19380 (Sarkis 2001) - unies autour de leur appropriation de la thématique du paradis judéo-chrétien, permettent à cette recherche de se centrer autour d'une actualisation de l'Éden. Partant ainsi du prédicat selon lequel cette sacralité postmoderne serait dédivinisée, nous adoptons un regard iconologique afin de traquer ce motif édénique et d'en mesurer l'actualisation et la pertinence. Le but est de voir le fonctionnement de cette incarnation tautologique dans les œuvres et d'en préciser ainsi les répercussions sur la notion de sacré et de croyance pour notre contemporanéité. Ainsi se dévoile un sacré empreint d'humanité et de nihilisme. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Art contemporain, Sacré, Éden, Réenchantement, Marc Quinn, Raqib Shaw, Sarkis.

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