Il est aujourd'hui avéré que la composition chimique de l'atmosphère des régions enneigées - et notamment des régions polaires - est sensiblement affectée par les échanges d'espèces chimiques réactives entre l'air et la neige. En effet, le manteau neigeux constitue un véritable réacteur photochimique multiphasique, mais les mécanismes physico-chimiques à l'œuvre en son sein sont encore mal connus. Une compréhension détaillée des processus s'y déroulant est indispensable pour modéliser correctement la composition et la réactivité de l'atmosphère au-dessus des régions enneigées. De plus, la reconstitution de l'évolution post-dépôt des composés chimiques stables de la neige est également un préalable indispensable pour permettre l'interprétation paléoclimatique de leurs profils de concentration enregistrés dans les carottes de glace.Le nitrate (NO3-) présent dans la neige joue un rôle fondamental, car sa photolyse induit notamment l'émission d'oxydes d'azote (NOx = NO + NO2) par le manteau neigeux, qui modifient la capacité oxydante de l'atmosphère via la production d'ozone. L'objet de cette thèse a donc été d'étudier par modélisations les processus physico-chimiques intervenants dans l'évolution de la concentration du nitrate dans la neige.Une première approche, prolongeant des études préexistantes, a visé à identifier un mécanisme réactionnel pour la photochimie du nitrate dans la neige, en postulant notamment l'existence d'une couche quasi-liquide à la surface des grains de neige. Néanmoins, les propriétés exactes de l'interface air - glace sont, à l'heure actuelle, encore mal caractérisées, et il est apparu que cette démarche présentait de trop larges incertitudes pour être poursuivie.Une discussion approfondie a alors été menée afin d'évaluer les tentatives actuelles de modélisation de la chimie de la neige, et dans le but de proposer une nouvelle approche plus réaliste au regard du niveau de connaissance actuel.Ainsi, dans une seconde partie, l'ensemble des processus d'échange physico-chimiques du nitrate entre l'air et la neige ont été étudiés puis modélisés : adsorption à la surface, diffusion en phase solide et co-condensation. Parmi les résultats obtenus, il est apparu que les paramétrisations actuelles de la couverture surfacique en nitrate étaient incapables de reproduire les concentrations mesurées, dans le cas de la neige de surface à Dome C, et révèlent d'importantes surestimations. A contratio, la prise en compte conjointe de la diffusion en phase solide ainsi que d'un processus de co-condensation permet de bien reproduire qualitativement les séries temporelles de plus d'un an, couvrant donc à la fois l'été et l'hiver austral, qui présentent chacun des caractéristiques distinctes en terme de concentration mesurées.Cette étude révèle ainsi l'importance de ces processus physico-chimiques d'échange dans la modélisation de la chimie de la neige, et pose les bases des mécanismes à prendre en compte dans le cadre de développements futurs.

The settlement history of the Vredefort Dome can be described as a process of cultural development. The Vaal River hydrosphere, which was for many years a prestigious settlement site, initially attracted large scale game and later livestock farmers. The drifts were a central part of a network of early strategic communication routes and outspans. From 1838, pioneer settlement, farm occupation and agricultural development followed, and the area eventually entered an agriculture-mining era. Gold-mining stimulated the regional economy and also played a significant role in the development of towns in the area. The Vaal River did not play a significant role from a mining perspective, but featured more prominently in the development of villages and, in a sense, served as a political boundary. The location of the water source often determined where people settled permanently. It also decided the position of the house and yard. From the outset, riparian dwellers attempted to manipulate the flow of the river by creating dams and utilising water for irrigation and domestic purposes. Drought conditions also left historical traces; water management projects upstream transformed the Vaal River into a steadily flowing stream, which led to the economic and cultural segregation of north and south. Man's fear associated with drought (too little water), floods (too much water), meteorology (the necessity of water), and the role of the supernatural (divining water) and superstition (the water snake stories) were expressed in the interaction between people and this water environment. A wide variety of people with distinct cultures lived alongside each other in the area. Western and African cultural goods, as well as customs and beliefs, were mutually adopted by these different cultural groups as a result of this contact. The way land has been used in the Dome area has evolved over the years. The culling of game made way for the permanent establishment of the livestocktravelling farmer. Hereafter prolonged drought conditions destroyed pastures and, consequently, large areas of land were ploughed for agricultural use. Agriculture, which is more labour intensive and needs more water for irrigation, was replaced by game farming, which is less labour intensive and requires less water This world heritage site has drawn global interest and ecotourism has attracted visitors to the Vaal River area. The riparian dwellers, however, remain victims of up-stream industrial and sewage pollution; in future, they are likely to fall prey to acid mine water pollution, with disastrous consequences. / PhD (History), North-West University, Vaal Triangle Campus, 2013

Difficult gradient calculations, converging to a local optimum without exploring the design space adequately, too much dependency on the starting solution, lacking capabilities to treat discrete and mixed design variables are the main drawbacks of conventional optimization techniques. So evolutionary optimization methods received significant interest amongst researchers in the optimization area. Genetic algorithms (GAs) and simulated annealing (SA) are the main representatives of evolutionary optimization methods. These techniques emerged as powerful and modern strategies to efficiently deal with the difficulties encountered in conventional techniques, and therefore rightly attracted a substantial interest and popularity. The underlying concepts of these techniques and thus their algorithmic models have been devised by establishing between the optimization task and events occurring in nature. While, Darwin&amp / #8217 / s survival of the fittest theory is mimicked by GAs, annealing process of physical systems are employed to SA. On the other hand, dome structures are among the most preferred types of structures for large unobstructed areas. Domes have been of a special interest in the sense that they enclose a maximum amount of space with a minimum surface. This feature provides economy in terms of consumption of constructional materials. So merging these two concepts make it possible to obtain optimum designs of dome structures. This thesis is concerned with the use of GAs and SA in optimum structural design of dome structures, which range from some relatively simple problems to the problems of increased complexity. In this thesis, firstly both techniques are investigated in terms of their practicality and applicability to the problems of interest. Then numerous test problems taken from real life conditions are studied for comparing the success of the proposed GA and SA techniques with other discrete and continuous optimization methods. The results are discussed in detail to reach certain recommendations contributing to a more efficient use of the techniques in optimum structural design of pin-jointed 3-D dome structures.

Le nouveau moteur cryogénique de l'étage supérieur du nouveau lanceur Ariane présente la particularité d'être plusieurs fois réallumable, une fois la mise en orbite du lanceur. Le réallumage d'un moteur est particulièrement difficile durant les conditions de vol spatial. Ce moteur est composé d'un dôme LOX alimenté en oxygène liquide (LOX) qui est approvisionné par une vanne à boisseau positionnée en entrée d'une canne d'alimentation. Le mélange liquide / gaz formé dans le dôme LOX est injecté dans la chambre de combustion à travers des injecteurs reliant le dôme à la chambre. En conséquence, la distribution de l'écoulement diphasique en sortie des injecteurs revêt une importance particulière en terme d'allumage, de l'ouverture à la fermeture de cette vanne. La prise en compte de ces conditions de vol est primordiale pour qualifier le moteur. Cependant ces conditions ne peuvent pas être reproduites de façon représentative au cours d’essais au sol. Dans le cadre de ces études, un programme de recherche a été mis en place par le CNES (Centre National d'Études Spatiales) et SAFRAN Snecma pour étudier le remplissage du dôme LOX, via des études expérimentales et numériques. L'objectif est de connaître les conditions aux limites en sortie des injecteurs qui sont déterminantes pour appréhender la phase d'allumage dans la chambre de combustion. Des expériences ont été menées au LEGI (Laboratoire des Écoulements Géophysiques et Industriels) avec des fluides de substitution (de l'eau et de l'air), sans transfert de masse et de chaleur, sur la maquette du dôme d’alimentation d'un moteur de fusée. Les travaux présentés, menés à l'IMFT (Institut de Mécanique des Fluides de Toulouse), tentent de reproduire les expériences réalisées à l'aide de simulations numériques 3D incompressibles diphasiques. La géométrie du domaine de calcul est représentative de la maquette expérimentale, qui est composée d'une canne d'alimentation, d'un dôme, d'un allumeur et d'un grand nombre d'injecteurs. Le but de cette étude est de démontrer la faisabilité d'un calcul 3D instationnaire diphasique du remplissage du dôme oxygène du moteur-fusée avec le code industriel NEPTUNE_CFD, en prenant en compte la géométrie réelle et les phénomènes physiques prépondérants. La comparaison des prédictions avec les résultats expérimentaux est réalisée afin d'évaluer la capacité du code à prédire l'écoulement à l'aide des modèles de fermeture disponibles. Enfin, plusieurs études de sensibilité sur les modèles de fermeture sont menées pour estimer leur influence sur les résultats des simulations. Un travail important a été effectué pour imposer les mêmes conditions d'entrée que dans les expériences. Des études ont également été conduites sur un injecteur isolé. / New generation cryogenic upper-stage rocket engines are planned to be restartable during the orbit mission. The re-ignition of the engine is particularly difficult in space flight conditions. The engine contains a LOX dome fed with liquid oxygen (LOX) supplied by a bushel valve through a pipe. The gas / liquid mixture forming in the dome is injected into the combustion chamber through a number of injectors. Therefore the two-phase flow distribution at injectors outlet carries a real importance in terms of the ignition from the opening to the closing phases of the main valve. These flight conditions are of paramount importance, however, they are truly difficult to reproduce by experimental ground tests. In the framework of these studies, a research program set up by CNES (the French Space Agency) and SAFRAN Snecma, tries to study the LOX dome filling, through experiments and numerical studies. The aim is to identify the phenomena at sake to know the limit conditions at injectors, which will determine the ignition stage in the combustion chamber. Experiments are carried out at LEGI (Geophysical and Industrial Flows Laboratory in Grenoble) with substitution fluids (air and water), without heat and mass transfer on a rocket engine mockup. The work presented here, conducted at IMFT (Fluid Mechanics Institute in Toulouse), intends to reproduce the experimental results using incompressible two-phase flow simulations. The geometry used is representative of the experimental mockup composed of a feeding pipe, a dome, an igniter pipe and injectors. The aim of this study is to demonstrate the feasibility of a 3D unsteady two-phase flow calculation with the industrial code NEPTUNE_CFD, to simulate the LOX dome filling of the rocket engine, by taking into account the real geometry and the preponderant physical phenomena. The comparison of the predictions with the experimental results is carried out in order to estimate the code capability to predict the flow behavior, according to available closure laws. Finally, several sensitivity studies on the closure laws have been conducted to assess their influence on the numerical results. An important work has been carried out to obtain the proper inlet conditions to be imposed in the code in coherence with the experiments. Studies have equally been conducted on an isolated injector.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A formação ferrífera do Serrote do Breu e de Alto das Pedras localiza-se no município de Campo Grande, Estado de Alagoas e está sendo pesquisada quanto ao seu potencial como minério de ferro. Ela está inserida em um domo de embasamento arqueano no interior da Faixa Sergipana, o Domo de Jirau de Ponciano. A área de estudo é caracterizada por dois altos topográficos denominados Serrote do Breu e Alto das Pedras, sustentados pela formação ferrífera, e que representam flancos opostos de um sinformal inclinado, com direção N60W e forte mergulho para sul, e extensão total de aproximadamente 2 km. A formação ferrífera ocorre em diversas camadas intercaladas em gnaisses quartzo-feldspáticos e em rochas metamáficas. Os primeiros foram agrupados na unidade de gnaisses quartzo-feldspáticos e as últimas na suíte intrusiva máfica-ultramáfica. Na porção interior do sinformal estão quartzitos e paragnaisses agrupados na unidade metassedimentar e cortando essas unidades há uma unidade de pegmatitos. A formação ferrífera é constituída por quartzo, hematita, anfibólio e magnetita. O anfibólio é em geral cummingtonita, mas riebeckita também ocorre subordinadamente. Os teores médios de SiO2, e Fe2O3t são 43,1% e 50,7%, respectivamente, e, assim como os demais elementos maiores, são compatíveis com outras formações ferríferas do mundo. Com base na petrografia e geoquímica de elementos terras raras os gnaisses quartzo-feldspáticos foram divididos em gnaisses bandados e gnaisses com titanita. Ambos apresentam composição riolítica e trend calcio-alcalino. Já as rochas metamáficas e metaultramáficas apresentam composição basáltica a andesítica e trend toleítico completamente dissociado daquele dos gnaisses. Acredita-se que os gnaisses quartzo-feldspáticos e as rochas metamáficas e metaultramáficas tenham se formado em ambientes tectônicos totalmente distintos, com as últimas tendo se formado provavelmente intrusivas nos primeiros. / Serrote do Breu and Alto das Pedras are located in the municipality of Campo Grande, in the State of Alagoas where an iron-formation occurs. It is currently being explored for its potential for hosting an iron ore deposit. It is tectonically settled inside Jirau do Ponciano Dome, an Archean basement within Sergipano Belt. Serrote do Breu and Alto das Pedras are two topographic highs totaling 2 km in length, marked by outcrops of iron-formation which represent opposite limbs of an inclined sinformal elongated N60W and dipping steeply to the South. This iron-formation comprises of several layers intercalated with quartz-feldspathic and metamafic rocks. The former were grouped into quartz-feldspathic gneisses unit and the latter into mafic-ultramafic intrusive suite. Quartzites and paragneisses were mapped and grouped into metasedimentary unit and all units are cross-cutted by pegmatites unit. Iron-formation is constituted by quartz, hematite, amphibole and magnetite. Amphibole is commonly cummingtonite, but riebeckite also occurs. Average grades for SiO2 and Fe2O3t are 43,1% and 50,7%, respectively, and along with other major elements, are similar to other iron-formations of the world. Considering petrographical and geochemical data, quartz-feldspathic gneisses were divided into banded gneisses and sphene-bearing gneisses although both presents rhyolitic composition and calc-alkaline trends. Metamafic and metaultramafic rocks present basaltic to andesitic composition and show a tholeiitic trend completely different from that of gneisses. It is proposed here that these distinct rocks were formed in completely different tectonic settings with the latter being probably intrusive in the former.

Ce travail a pour but de proposer une nouvelle approche du dimensionnement optimisé des réservoirs de stockage d’hydrogène de type IV visant à mieux répondre aux enjeux industriels. Les objectifs scientifiques et techniques consistent à disposer de modèles qualifiés pour la simulation du comportement de ces réservoirs, associés à des méthodologies de dimensionnement et d’optimisation fiables. La démarche s’appuie sur trois axes principaux :– proposer une démarche de conception prédictive en intégrant (i) un premier aspect lié à la ruine de la structure qui est la conséquence de mécanismes complexes et multiples d’endommagement s’initiant, s’accumulant et se développant dans un milieu anisotrope et (ii) des modèles de simulation de la structuration composite spécifique au procédé d’enroulement filamentaire, technologie employée largement dans la fabrication des réservoirs de stockage à haute pression. Leurs implémentations constituent une première avancée face à l’existant ;– choisir et évaluer les paramètres structuraux par une démarche d’optimisation où nous sommes amenés à utiliser (i) des méthodes de métamodélisation permettant de répondre aux contraintes de coûts, (ii) des méthodes spécifiques de tri et (iii) des méthodes à spectres larges qui recherchent des solutions sur une large population telles que des méthodes génétiques ;– qualifier la démarche dans sa globalité par une comparaison entre calculs et essais. Ainsi, la finalité de ce travail est de développer et valider des modèles et méthodes pour permettre de mieux concevoir, tester et fabriquer à moindre coût un réservoir avec une structure calculée optimisée. / The purpose of this study is to suggest a new way to design type IV high pressure hydrogen composite vessels to better fulfil industrial requirements. Developing suitable models for the comportment’s simulation of these vessels in relation with a reliable design method is the main scientific and technical aim. This approach relies on the three following lines :– perform a predictive design method using the most recent theoretical and numerical works investigated on composite materials and more specifically in taking into account (i) an essential aspect linked to the structural failure which is the consequence of the initiation, accumulation and propagation of complex damage mechanisms and (ii) the use of specific composite lay-up models related to the filament winding process, used for pressure vessels manufacturing. These approaches are significant breakthroughs compared with previous studies ;– choose and assess structural parameters with an optimisation approach where we use (i) surrogate methods to meet economic requirements, (ii) specific sorting methods and (iii) broad-spectrum methods such as genetic algorithm methods ;– approve of the whole approach by theoretical and experimental comparisons.The goal of the project will be to develop, provide and approve models to enable a better conception and industrialisation of an optimal high pressure vessel in relations with costs.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A formação ferrífera do Serrote do Breu e de Alto das Pedras localiza-se no município de Campo Grande, Estado de Alagoas e está sendo pesquisada quanto ao seu potencial como minério de ferro. Ela está inserida em um domo de embasamento arqueano no interior da Faixa Sergipana, o Domo de Jirau de Ponciano. A área de estudo é caracterizada por dois altos topográficos denominados Serrote do Breu e Alto das Pedras, sustentados pela formação ferrífera, e que representam flancos opostos de um sinformal inclinado, com direção N60W e forte mergulho para sul, e extensão total de aproximadamente 2 km. A formação ferrífera ocorre em diversas camadas intercaladas em gnaisses quartzo-feldspáticos e em rochas metamáficas. Os primeiros foram agrupados na unidade de gnaisses quartzo-feldspáticos e as últimas na suíte intrusiva máfica-ultramáfica. Na porção interior do sinformal estão quartzitos e paragnaisses agrupados na unidade metassedimentar e cortando essas unidades há uma unidade de pegmatitos. A formação ferrífera é constituída por quartzo, hematita, anfibólio e magnetita. O anfibólio é em geral cummingtonita, mas riebeckita também ocorre subordinadamente. Os teores médios de SiO2, e Fe2O3t são 43,1% e 50,7%, respectivamente, e, assim como os demais elementos maiores, são compatíveis com outras formações ferríferas do mundo. Com base na petrografia e geoquímica de elementos terras raras os gnaisses quartzo-feldspáticos foram divididos em gnaisses bandados e gnaisses com titanita. Ambos apresentam composição riolítica e trend calcio-alcalino. Já as rochas metamáficas e metaultramáficas apresentam composição basáltica a andesítica e trend toleítico completamente dissociado daquele dos gnaisses. Acredita-se que os gnaisses quartzo-feldspáticos e as rochas metamáficas e metaultramáficas tenham se formado em ambientes tectônicos totalmente distintos, com as últimas tendo se formado provavelmente intrusivas nos primeiros. / Serrote do Breu and Alto das Pedras are located in the municipality of Campo Grande, in the State of Alagoas where an iron-formation occurs. It is currently being explored for its potential for hosting an iron ore deposit. It is tectonically settled inside Jirau do Ponciano Dome, an Archean basement within Sergipano Belt. Serrote do Breu and Alto das Pedras are two topographic highs totaling 2 km in length, marked by outcrops of iron-formation which represent opposite limbs of an inclined sinformal elongated N60W and dipping steeply to the South. This iron-formation comprises of several layers intercalated with quartz-feldspathic and metamafic rocks. The former were grouped into quartz-feldspathic gneisses unit and the latter into mafic-ultramafic intrusive suite. Quartzites and paragneisses were mapped and grouped into metasedimentary unit and all units are cross-cutted by pegmatites unit. Iron-formation is constituted by quartz, hematite, amphibole and magnetite. Amphibole is commonly cummingtonite, but riebeckite also occurs. Average grades for SiO2 and Fe2O3t are 43,1% and 50,7%, respectively, and along with other major elements, are similar to other iron-formations of the world. Considering petrographical and geochemical data, quartz-feldspathic gneisses were divided into banded gneisses and sphene-bearing gneisses although both presents rhyolitic composition and calc-alkaline trends. Metamafic and metaultramafic rocks present basaltic to andesitic composition and show a tholeiitic trend completely different from that of gneisses. It is proposed here that these distinct rocks were formed in completely different tectonic settings with the latter being probably intrusive in the former.

With the purpose of analyzing José de Dome’s artistic production as well as his importance for visual arts and its teaching, this work investigated his development and acting on his social environment, between 1955, when his first individual exhibition was held, and 1981, which marked the last exhibition of his life. This study is grounded on a qualitative approach as well as the theoretical and methodological framework of Cultural History, alert to Pierre Bourdieu’s (2001) warning about “illusory biography”, “indiciary paradigm” brought forward by Carlo Ginzburg (1989) and the “fissures and contradictions of normative systems” analyzed by Giovanni Levi (1992). It also grounds itself on the teachings of Norbert Elias (1996) and Vavy Pacheco Borges (2014) about the genre biography. For a history of modern art, we turned to the studies undertaken by Giulio Carlo Argan (2001) about Expressionism, and José D’Assunção Barros’ observations concerning the importance of African art in the history of modern art. As to the issues relating to the Afro-Brazilian art, we relied on the work by Arnaldo Marques da Cunha (2015). For the analysis of the artistic images, we made use of the concepts developed by Erwin Panofsky (2012) about the “meaning in the visual arts”, and the studies by Michael Baxandall (2006) about the “fabric of human intentions in the historical explanation of pictures”. In the light of the theoretical and methodological postulates of Cultural History that structure the biographical genre, we searched through printed texts, especially newspapers that circulated during the biographee’s lifetime as well as the interviewees’ statements in which he was given a mention. We established an articulation between the artist’s life experiences and his production, by placing some emphasis on the individual and his accomplishments. We pointed out that, on José de Dome’s paintings, his formal freedom, focus on Brazilian themes and chromatism confer upon his art particularly autochthonous characteristics, which place his name amongst the representatives of Brazilian Expressionism in the history of visual arts. We regard this work as a contribution to the teaching-learning process in the visual arts, since it produces knowledge on the reading of artistic images as well as the history of visual Arts and its producers.________________________________________________________________________________________________________________________________ / Afin d'analyser la production artistique de José de Dome et son importance pour les arts visuels et son enseignement, le présent travail a étudié la formation et la performance de cet artiste dans son environnement social, entre les années 1955, date de sa première exposition individuelle, et 1981, l'année de sa dernière exposition, alors qu'il vivait. Il s’agit d’une recherche à approche qualitative basée sur les hypothèses théoriques et méthodologiques de l'Histoire Culturelle, attentive à l'avertissement de Pierre Bourdieu (2001) sur «l'illusion biographique», au «paradigme indiciaire» présenté par Carlo Ginzburg ( 1989), et aux "lacunes et contradictions des systèmes normatifs" analysées par Giovanni Levi (1992). Il est également basé sur les enseignements de Norbert Elias (1996) et Vavy Pacheco Borges (2014) concernant le genre biographique. Dans l'Histoire de l'art moderne, ont été utilisés les études réalisées par Giulio Carlo Argan (2001) sur l'Expressionnisme et aussi les considérations de José D'Assunção Barros (2015) sur l'importance de l'art africain dans l'Histoire de l'art moderne. En ce qui concerne les questions sur l'art Afro-brésilien, il a été utilisé comme référence, le travail présenté par Arnaldo Marques da Cunha (2015). Pour l'analyse des images artistiques, on a recherché un soutien théorique dans les concepts d'Erwin Panofsky (2012) sur la «Signification dans les arts visuels» et dans les études de Michael Baxandall (2006) sur le «tissu des intentions humaines dans l'explication historique des toiles". A la lumière des hypothèses théoriques et méthodologiques de l'Histoire Culturelle qui structurent le genre biographique, une recherche a été réalisée dans des textes imprimés, notamment dans les journaux en circulation à l’époque du biographe et dans les discours des interviewés qui s'y référaient. Il a été établie une articulation entre l'expérience de l'artiste et sa production, mettant en évidence l'individu avec les histoires de ses performances. On souligne que dans les toiles de José de Dome, sa liberté formelle, la thématique brésilienne et le chromatisme qu'il utilise, donnent à son art, des caractéristiques spécificiques, autochtones, qui incluent son nom dans l'Histoire des arts visuels, entre les représentants de l'Expressionnisme brésilien. On considère ce travail comme une contribution au processus d'enseignement et d'apprentissage en Arts Visuels, pour produire des connaissances sur la lecture d'images artistiques et sur l'Histoire des Arts Visuels et de ses producteurs. / Com o intuito de analisar a produção artística de José de Dome e a sua importância para as artes visuais e o seu ensino, o presente trabalho investigou a formação e a atuação do referido artista, no seu ambiente social, entre os anos de 1955, data da sua primeira exposição individual, e 1981, ano da sua última exposição, enquanto vivia. Trata-se de uma pesquisa de abordagem qualitativa que tem por fundamentação os pressupostos teóricos e metodológicos da história cultural, atenta ao alerta de Pierre Bourdieu (2001), a respeito da “ilusão biográfica”, ao “paradigma indiciário” apresentado por Carlo Ginzburg (1989), e às “brechas e contradições dos sistemas normativos” analisadas por Giovanni Levi (1992). Fundamenta-se, também, nos ensinamentos de Norbert Elias (1996) e Vavy Pacheco Borges (2014) a respeito do gênero biográfico. Na história da arte moderna, foram utilizados os estudos realizados por Giulio Carlo Argan (2001) sobre o Expressionismo, e também as considerações de José D’Assunção Barros(2015), a respeito da importância da arte africana, na história da arte moderna. Quanto às questões que dizem respeito à arte afro-brasileira, foi utilizado como referência, o trabalho apresentado por Arnaldo Marques da Cunha (2015), e, para a análise das imagens artísticas, buscou-se suporte teórico nos conceitos de Erwin Panofsky (2012) sobre o “significado nas artes visuais”, e nos estudos de Michael Baxandall (2006) a respeito do “tecido de intenções humanas na explicação histórica dos quadros”. À luz de pressupostos teóricos e metodológicos da história cultural que estruturam o gênero biográfico, foi realizada uma pesquisa, em textos impressos, especialmente nos jornais em circulação, na época do biografado, e na fala dos entrevistados que a ele fizeram referência. Estabeleceu-se uma articulação entre a vivência do artista e a sua produção, evidenciando o indivíduo com as histórias das suas atuações. Destaca-se que, nas pinturas de José de Dome, a sua liberdade formal, a temática brasileira e o cromatismo por ele utilizado dão à sua arte características específicas, autóctones, que incluem o seu nome na história das artes visuais, entre os representantes do expressionismo brasileiro. Considera-se este trabalho como um contributo ao processo de ensino e de aprendizagem em artes visuais, por produzir conhecimentos a respeito da leitura de imagens artísticas e sobre a história das artes visuais e dos seus produtores. / São Cristóvão, SE

The ability to view the world from multiple perspectives is essential for tackling complex, interconnected challenges. Yet conventional academic structures are designed to produce knowledge through ever-increasing specialization and compartmentalization. This fragmentation is often reinforced by tacit dualistic assumptions that prioritize linear thinking and abstract ways of knowing. Though the need for integrated approaches has been widely acknowledged, effective techniques for transcending disciplinary boundaries remain elusive. This thesis describes a practical strategy that uses immersive visualizations to cultivate transdisciplinary perspectives. It develops an enactive approach to cosmography, contending that processes of visualizing and interpreting the cosmos iteratively shape ‘views’ of the ‘world.’ The archetypal trope of the heavenly sphere is examined to demonstrate the significance of its interpretations in this history of ideas. Action research and mixed methods are employed to elucidate the theoretical considerations, cultural relevance, and practical consequences of this approach. The study begins with an investigation into the recurring appearance of the heavenly sphere across time, in which its embodied origins, metaphorical influence, and material embodiments are considered. Particular attention is given to how cosmographic tools and techniques have facilitated imaginary ‘flights’ through the heavens, from the ecstatic bird’s eye view of the shaman to the ‘Archimedean point’ of modern science. It then examines how these cosmographic practices have shaped cosmological beliefs and paradigmatic assumptions. Next, the practical utility of this approach is demonstrated through the development of cosmographic hermeneutics, a technique using visual heuristics to interpret cosmic models from transdisciplinary world views. Finally, the performative practice of cosmotroping is described, in which cosmographic hermeneutics are applied to re-imagine the ancient dream of the transcendent ‘cosmic journey’ within immersive vision theaters. This study concludes that the re-emergence of the heavenly sphere within the contemporary Digital Universe Atlas provides a leverage point for illuminating the complexity of knowledge production processes. It is claimed that this research has produced a practical strategy for demonstrating that the ultimate Archimedean point is the ability to recognize the limits of our own knowledge, a crucial first step in cultivating much-needed multi-perspectival and paradoxical spherical thinking.

Les dômes de lave sont associés à des éruptions volcaniques violentes et des indices d’explosivité élevés. L’observation et la surveillance de dômes actifs (e.g. St. Helens, Unzen, Montserrat) ont mis en évidence des modes de croissance caractérisés par des phases d’extrusion, d’explosion et des phénomènes d’effondrement, impliquant une structure interne souvent complexe de ces édifices volcaniques. L’étude du Puy de Dôme (Massif Central français), un dôme trachytique âgé de 11 000 ans, grâce à l’apport de l’imagerie géophysique et à la modélisation des données, ainsi qu’à une analyse morpho-structurale détaillée, a permis d’établir un modèle précis de la structure interne du dôme et a fourni de nouvelles contraintes concernant sa croissance et son évolution. L’analyse du Modèle Numérique de Terrain haute résolution (0,5 m) a permis d’identifier différentes unités sur le dôme, morphologiquement distinctes, et associées à des dynamismes éruptifs différents, ainsi que des structures volcano-tectoniques remarquables sur les édifices volcaniques voisins (Petit Puy de Dôme et Puy des Grosmanaux). Différentes méthodes géophysiques (tomographie des résistivités électriques – ERT -, gravimétrie et magnétisme) ont été mises en oeuvre afin d’étudier la structure interne du dôme, et de caractériser la nature des mécanismes à l’origine des zones de déformations identifiées dans l’environnement du Puy de Dôme. L’utilisation de plusieurs méthodes a permis d’étudier des paramètres physiques différents mais complémentaires, bien que l’interprétation globale des résultats géophysiques ait parfois été délicate dans le cas d’un édifice volcanique aussi complexe. Les modèles géophysiques 2D et 3D obtenus montrent que le Puy de Dôme repose sur des édifices volcaniques préexistants, un ensemble de volcans stromboliens dont la présence et/ou l’extension exacte étaient partiellement méconnues jusqu’alors. La structure interne de l’édifice, très hétérogène, est constituée d’une partie centrale très massive, entourée d’une ceinture de brèches d’effondrement, la zone sommitale du conduit étant affectée de nombreuses évidences d’une forte altération hydrothermale, caractéristique des dômes volcaniques. La partie supérieure du dôme est définie par une carapace de roches consolidées, de quelques dizaines de mètres d’épaisseur au maximum, alors que la base de l’édifice forme un talus constitué des dépôts d’effondrements gravitaires et d’écoulements pyroclastiques associés à la croissance du dôme. Enfin, les données gravimétriques et magnétiques ont permis la mise en évidence de la présence d’intrusions sous les édifices du Petit Puy de Dôme et du Puy des Grosmanaux. La géométrie de ces intrusions, déterminées grâce à différentes approches de modélisation, ainsi que la nature des roches qui les composent indiquent des processus de mise en place complexes. / Volcanic domes are associated to violent volcanic eruptions and high explosivity indexes. Observation and monitoring of active domes (e.g. St. Helens, Unzen, Montserrat) underlined growth patterns characterized by extrusion phases, explosions and collapse events, involving the complex inner structure of these volcanic edifices. The study of the Puy de Dôme volcano (French Massif Central), a 11,000 years old trachytic lava dome, through geophysical imaging and data modelling, as well as a detailed morpho-structural analysis, allowed to build a precise model of the inner structure of the dome and provided new constraints about its growth and its evolution. The analysis of the high resolution Digital Terrain Model (0.5 m) allowed to identify distinct morphological units on the dome, as well as volcano-tectonic structures on the neighboring volcanic edifices (Petit Puy de Dôme and Puy des Grosmanaux). Different geophysical methods (Electrical Resistivity Tomography – ERT -, gravity and magnetism) have been implemented in order to study the inner structure of the dome and to characterize the initiating mechanisms of the deformations areas identified in the Puy de Dôme vicinity. The use of several methods allowed to study different, but complementary physical parameters, although the overall interpretation of the geophysical results is sometimes difficult in the case of a volcanic edifice so complex. The 2D and 3D geophysical models obtained indicate that the Puy de Dôme is based on preexisting volcanic edifices, a cluster of strombolian volcanoes whose the presence and/or the exact extension were partially unknown until now. The internal structure of the edifice, highly heterogeneous, is composed of a massive central part, encompassed of collapse breccia, and its summit part highlights evidences of a strong hydrothermal alteration, characteristic feature of volcanic domes. The upper part of the dome is defined by a carapace of consolidated rocks, a few meters thick, whereas the base of the edifice forms a talus composed of collapses and pyroclastic flows deposits associated to the dome growth. Finally, gravity and magnetic data pointed out the presence of intrusions beneath the Petit Puy de Dôme and the Puy des Grosmanaux edifices. The geometry of these intrusions, determined through different modelling approaches, and the nature of the rocks that composed them, indicate complex emplacement processes.