The thermal conductivity of various porous thermal barrier coating (TBC) systems used in elevated temperature for industrial applications has been evaluated using a proposed six-phase model. These porous TBC systems rely on microstructural properties and yield different types of porosity. These microstructural properties can influence the thermal conductivity of TBC systems. The purpose of this thesis is to assess the thermal conductivity of TBC systems based on microstructural attributes, particularly the effect of different types of porosity. Thus, the first component of this thesis investigates the microstructural characterization of various TBC systems using image analysis (IA) technique. In this technique, scanning electron microscopy (SEM) and light optical microscopy (LOM) micrographs were used to measure the porosity level of different TBC materials. The volumetric fraction of porosity along with orientation, shape, and morphology have a considerable impact on the total thermal conductivity of TBCs. The second component of this thesis evaluates the thermal conductivity of these porous TBC systems by taking into account the effect of the heat treatment process. The IA results reveal that as long as the porosity content increases, the thermal conductivity decreases for all of the TBC materials studied in this thesis. Further, while the content of microcracks and non-flat porosity play a crucial role in reducing the thermal conductivity of TBC materials, the other types of porosity (open randomly oriented, penny-shaped, and interlamellar) exert less impact on the thermal conductivity of TBCs. Comparing the results of the proposed six-phase model to experimental values and finite element analysis (FEA) values showed a relatively good agreement. The proposed six-phase model can predict the thermal conductivity of porous microstructure of TBC systems close to real measured values; therefore, the proposed six-phase model may be utilized to fabricate the porous microstructure of TBCs.

Reconhece-se, por estudos prévios, as complexas heterogeneidades de fácies nos depósitos sedimentares siliciclásticos fluviais, presentes na exploração de hidrocarbonetos. Devido à amostragem, custosa e insuficiente, na indústria, os modelos geológicos construídos possuem alta incerteza associada. Visando auxiliar tanto a exploração quanto a recuperação, foram executados estudos de análogos de reservatório na Formação São Sebastião, na Bacia do Tucano Central. Para isso, com base na dinâmica de processos fluviais, integraram-se análises de micro (petrografia e diagênese) e mesoheterogeneidades (fácies e elementos arquiteturais) tridimensionalmente, junto à permoporosidade, culminando em modelos geológicos de elementos arquiteturais, fácies e permeabilidade. As características permoporosas da Formação São Sebastião estão sujeitas tanto a controles deposicionais (elementos arquiteturais) como a controles diagenéticos (petrofácies), os quais se correlacionam. Os elementos arquiteturais, portadores de características mais efetivas como reservatório são as barras unitárias, seguidas pelas compostas. Em mesoescala, ambas são representadas majoritariamente por cruzadas tabulares e acanaladas de diferentes dimensões. A mediana para permeabilidade das barras unitárias e compostas é de 6000 mD e 4500 mD, enquanto para porosidade é de 21,0 % e 16,9 %, respectivamente. Em contrapartida, as barreiras de permeabilidademais importantes são representadas pelos topos de barra contínuos que majoritariamente apresentam estruturas de marca ondulada e estruturas plano paralelas, em mesoescala, e petrofácies com alta concentração de micas. A mediana de permeabilidade dos topos de barra é 200 mD, já a de porosidade é 13,5%. Como barreiras de permeabilidades subordinadas, encontram-se os canais abandondados (pouco freqüentes nos afloramentos), em mesoescala, representados por estruturas de marcas onduladas e convolutas; e, em microescala, relacionadas a altas concentrações de micas e pseudomatriz. A mediana da permeabilidade nos canais abandonados é 50 mD e a da porosidade é 16,1 %. Os modelos geológicos gerados com os dados de permeabilidade e fácies apontaram para anisotropias de baixa permeabilidade nos topos de barra e canais abandonados. Os topos de barra possuem continuidade lateral maior que 200 m em alguns locais, resultando em grande impacto no fluxo dentro do reservatório. As anisotropias de alta permeabilidade podem ser observadas principalmente na base dos depósitos de barras. Essas anomalias estão relacionadas com arenitos médios a grossos, portadores de cruzadas tabulares. Deste modo, nos depósitos analisados, a permeabilidade é controlada principalmente pela granulometria e concentração de pseudomatriz e micas, com influência subordinada das estruturas sedimentares. Já a porosidade, também controlada pela concentração de pseudomatriz e micas, possui forte influência das estruturas sedimentares e seleção granulométrica, mas não tem correlação com a granulometria. / The complex facies heterogeneities in fluvial deposits are present in the oil and gas industry. Due to expensive and insufficient sampling, in this industry, geological models which are created to assist the hydrocarbon exploration contain many uncertainties. Aiming to assist in this situation, studies on outcrops reservoirs analogues were performed in Sao Sebastião Formation, in Central Tucano Basin. Based on fluvial sedimentology, micro (petrography and diagenesis) and mesoheterogeneities (facies and architectural elements) analyses were conducted. Porosity and permeability were likewise analyzed. The data obtained were used to create architectural, facies and permeability models. Porosity and permeability are mainly controlled by two correlated variables: depositional controls (architectural elements) and diagenetic controls (petrofacies). The architectural elements with the most effective characteristics as reservoir are the unit bars, followed by the compound bars. Both architectural elements are represented by small to large (0.2 m up to 1.5 m) planar and through cross strata. The median permeability of unit bars is 6000mD, and the median of compound bars is 5000mD. The median porosity of unit bars is 21.0%, and the median of compound bar is 16.9%. On the other hand, the most important permeability barriers are the continuous bar tops, they are represented in mesoscale by climbing ripples structures and horizontal bedding. Bartops have shown a high mica assembly in microscale analyses. The median permeability of this element is 200mD, and the median porosity is 13.5%. The abandoned channels are subordinated permeability barriers in São Sebastiao Formation. In mesoscale they are mainly represented by climbing ripples structures and convolute bedding. In microscale they are related to high mica and pseudomatrix content. The permeability median of abandoned channels is 50 mD, and the median porosity is 16.1%. The geological models created also pointed out to bar tops and abandoned channels as permeability barriers. The bar tops can reach 200 m or more of lateral continuity, representing the highest flux barrier inside the reservoir. The positives anisotropies of permeability are linked to medium to coarse sandstones with planar cross strata. Therefore, in Sao Sebastiao Formation the permeability is controlled primarily by grain size, pseudomatrix and mica content. Sedimentary structures also impact the permeability subordinately. The porosity is handed likewise by the pseudomatrix and mica content, but also by the sedimentary structures and grain sorting. Nevertheless, porosity is not correlated with grain size.

[pt] O Travertino é uma rocha amplamente usada no mundo como rocha ornamental, mas suas propriedades petrológicas e mecânicas análogas a rochas carbonáticas de reservatório influenciaram em sua escolha para a compreensão do comportamento geomecânico destas formações. Neste sentido, este trabalho procurou analisar o comportamento geomecânico do Travertino Romano mediante um programa experimental que incluiu uma caracterização da petrologia, da estrutura porosa e do comportamento mecânico da rocha. Foi determinada sua estrutura e textura sedimentar, composição química, mineralógica e índices físicos. Além disso, sua complexa estrutura porosa foi caracterizada por análise de imagens 2D e 3D geradas no microscópio óptico e no micro-tomógrafo de raios-X, com a determinação da presença de macro e micro poros, distribuídos aleatoriamente na rocha com uma baixa conectividade, assim mesmo foi também estabelecida uma relação entre a porosidade e a resistência. Analisaram-se também os resultados dos ensaios de resistência mecânica, que tanto para o estado de tensão uniaxial como triaxial mostraram um decréscimo da resistência com o incremento da porosidade, apresentando um comportamento frágil na maioria dos casos. / [en] The Travertine is a rock widely used in the world as an ornamental rock, but their analogous petrological and mechanical properties to carbonate rocks of reservoir influenced his choice to be able to understand the geomechanical behavior of these formations. Thus, this study sought to analyze the geomechanical behavior of Roman Travertine through an experimental program that included a characterization of petrology, the porous structure and mechanical behavior of the rock. Sedimentary structure and texture, chemical, mineralogical composition and physical indexes was determined. Moreover, Its complex porous structure was characterized by analysis of 2D and 3D images generated in the optical microscope and X-Ray micro CT-scanner, with the determination of the presence of macro and micro pores, randomly distributed in the rock with a low connectivity, so it was also established a relationship between the porosity and strength. Also analyzed the test results of mechanical strength, both to the state of uniaxial to triaxial stress showed a decrease in resistance with increasing porosity, with a brittle behavior in most cases.

Oligonucleotides may become a new class of therapies with the potential of curing many today untreatable diseases. Oligonucleotides becomes increasingly more difficult to separate with an increase in length since the relative difference in retention of these very similar compounds becomes increasingly smaller. Therefore, coelution of impurities formed during synthesis may result in insufficient purity, which is necessary for therapeutic treatments. Oligonucleotides are also relatively large biomolecules, possibly consisting of hundreds of nucleotides. As a result, oligonucleotides may have limited diffusion through the stationary phase pores which affects separation performance. Surprisingly few studies have be published in this research area and a wider knowledge in how this affects separation is needed. In this master thesis, separation of deoxythymidine oligonucleotides with 5-30 mers in length were separated with 60, 100, 200 and 300 Å pore size reversed phase C4 columns. It was concluded that pore size resulted in more restricted diffusion if insufficient pore size was used. Poor peak performance was also observed with too large pore sizes which lead to less efficient separations.

Le traitement de carbonitruration est aujourd'hui un procédé très répandu pour augmenter la résistance mécanique des pièces en acier. Ce type de solution a fait ses preuves dans le cadre de pièces massives, mais l'oxydation interne des couches enrichies reste une limitation conséquente du traitement à pression atmosphérique.C'est dans cette optique scientifique que s'inscrit une partie de cette étude visant le développement d'un traitement de carbonitruration à basse pression, en vue d'une application industrielle. Les nombreuses investigations expérimentales réalisées sur la nuance 16MnCr5 ont permis le développement et la mise au point de deux cycles répondant à deux critères de profondeur de traitement : 0.25 — 0.4 mm et 0.7 — 1.2 mm. Les observations métallurgiques ne révèlent aucune forme de précipitation, ce qui n'est pas le cas lorsque que le traitement est appliqué à une nuance métallurgique plus fortement alliée (Fe - 0.18 %C - 3.12 % Cr - 0.7 %V -0.45 %W).D'un point de vue simulation, les outils de calculs thermodynamiques confirment et clarifient les phénomènes de précipitations observés. L'acier plus fortement allié (qui contient initialement des carbures de vanadium de type MC) présente des carbures de types M23C6 et M7C3 ainsi que des carbonitrures de types M (C, N). En complément à la détermination des phases en présence et de leur composition, une modélisation de la diffusion du carbone et de l'azote est proposée. Le modèle utilise des conditions aux limites déterminées expérimentalement, des coefficients de diffusion du carbone et de l'azote interdépendants issus de la littérature. La cinétique de refroidissement au cours de la trempe est déterminée pour alimenter le modèle de calcul de transformation de phases et simuler le profil de dureté. Le couplage des modèles développés donne des résultats très proches des profils de carbone, azote et duretés mesurés expérimentalement.Une autre partie du travail propose l'intégration du traitement de carbonitruration à basse pression au procédé de mise en œuvre MIM (Moulage par Injection de poudres Métalliques) permettant la réalisation des composants de formes complexes. Les pièces « MIM » obtenues par l'exploitation du feedstock commercial PolyMIM 16MnCr5 intégrant un système de liant soluble à l'eau présentent 10 % de porosité. Les résultats métallurgiques observés sur les pièces MIM carbonitrurées consécutivement au palier de frittage sont identiques à ceux observés sur des pièces massives. La comparaison des profils de diffusion en carbone et azote entre les pièces à 10 et20 % de porosité (obtenu par diminution de la durée du pallier de frittage) montre cependant que le taux de porosité influence la profondeur de traitement. / The carbonitriding treatment is now a widely accepted industrial process to improve the strength of treated steel parts. This type of solution has been proven in the case of massive parts, but internal oxidation of enriched layers remains a significant drawback of the treatment at atmospheric pressure.It is against this scientific backdrop that this project seeks to develop a carbonitriding treatment at low pressure for industrial application. Numerous experimental investigations carried out on the 16MnCr5 steel grade allowed the development of cycles answering two criteria of depth treatment: 0.25 - 0.4 mm 0.7 - 1.2 mm. Metallurgical observations show no form of precipitation, which however is no longer the case when the treatment is applied to a more highly alloyed steel grade (Fe - 0.18% C - 3.12% Cr - 0.7% V -0.45% W).From a simulation point of view, thermodynamic calculations confirm and clarify the precipitation phenomena observed. The more highly alloyed steel (which initially contains vanadium rich carbides of MC type) exhibits carbides of M23C6 and M7C3 type, and carbonitrides of M (C, N) type. To complement the determination of present phases and their composition, it is proposed that the diffusion of carbon and nitrogen be modeled. The model uses experimentally determined boundary conditions, and interdependent nitrogen and carbon taken from the literature. The kinetics of cooling during the quenching is determined to supply the calculation model of phase transformations and simulate the hardness profile. The coupling of developed models gives carbon, nitrogen and hardness profiles very similar to experimentally measured ones.The work also proposes the integration of the low-pressure carbonitriding treatment to the MIM (Metal Injection Moulding) process, allowing the production of complex shapes components. MIM parts obtained from the exploitation of the trade PolyMIM 16MnCr5 feedstock integrating a water-soluble binder system present 10% of porosity. Metallurgical results observed on MIM parts, carbonitrided consecutively to the sintering step are similar to those observed on massive wrought parts. Comparison of carbon and nitrogen profiles of carbonitrided MIM parts containing 10 and 20 % of porosity (obtained by reducing the length of the bearing sintering) shows that the porosity level influences the case depth of MIM parts.

O desenvolvimento de biomateriais com estrutura porosa visa permitir uma boa ancoragem biológica através do crescimento do tecido ósseo no interior dos poros, além de no caso de algumas ligas de titânio, proporcionar valores de módulo elástico semelhantes ao do osso, prevenindo assim o insucesso por reabsorção óssea na interface com o implante. O objetivo deste estudo foi avaliar o processamento de implantes porosos à base de titânio produzidos por metalurgia do pó, utilizando polímeros naturais como aditivos (albumina, amidos de arroz, batata, milho e a gelatina), e analisar a osteointegração desses implantes por ensaio in vivo. Foram obtidas, amostras de titânio comercialmente puro (Ticp) e da Liga Ti-13Nb-13Zr pelos processos de space-holder e suspensão; os polímeros naturais foram removidos termicamente (350°C/1h) previamente a sinterização (1300°C/1h e 1300°C/3h, respectivamente). As metodologias de processamento utilizando aditivos de baixo custo propiciaram a obtenção de implantes metálicos porosos de maneira simplificada, com porosidades diferenciadas, boa homogeneidade estrutural, grau de porosidade adequado (entre 40% e 60%), distribuição e tamanho dos poros conforme o polímero natural formador. Na caracterização biológica, o teste in vitro de citotoxicidade validou a utilização dos implantes para a realização do teste in vivo. A avaliação da osteointegração foi realizada em coelhos da raça New Zealand em períodos de 49 dias. Na análise histológica por microscopia eletrônica de varredura e fluorescência, foram obtidos os resultados quantitativos e qualitativos da osteointegração, com crescimento ósseo em todos os implantes, apresentando osteocondutividade. Os melhores resultados ocorreram em implantes com porosidade homogênea, e com tamanho médio de poros entre 100 e 200 μm. Assim, os materiais porosos de titânio e da liga Ti-13Nb-13Zr produzidos com os polímeros naturais (amido de arroz, amido de batata, amido de milho, gelatina e albumina), permitiram a nutrição e manutenção necessárias para a sobrevivência das células, comprovando a osteointegração e osteocondução dos implantes desenvolvidos. / The development of biomaterials with porous structure, seeks to allow a good biological anchorage through bone tissue ingrowth within the pores, besides to propitiate elastic modulus values similar to bone, thus preventing the failure by bone resorption, on implants interface. The goals of this study was to evaluate the processing of titanium based porous implants by powder metallurgy (PM), using natural polymers as additive (rice, potato and corn starches, albumin and gelatin), and evaluate these implants osseointegration by in vivo assay. Samples were obtained of commercially pure titanium (cpTi) and Ti-13Nb-13Zr alloy by space-holder and suspension techniques; the natural polymers were removed by thermal treatment (350C/1h) prior to sintering (1300C/1h and 1300C/3h respectively). The processing methodologies using low cost additives propitiate the production of porous metallic implants in a simplified manner, with differentiated porosities, good structural homogeneity, proper porosity degree (between 40% and 60%), distribution and pore size as the related natural polymer. The biological characterization was first performed in vitro with a cytotoxicity test, which allowed the use of implants in vivo. The osseointegration evaluation was performed in New Zealand White rabbits for 49 days period. Histological analyses with scanning electron microscopy and fluorescence microscopy were obtained quantitative and qualitative results of osseointegration, with bone growth in all implants, presenting osteoconductivity. The best results were in implants with homogenous porosity and with mean pore size between 100 and 200 μm. Thus, titanium and Ti-13Nb-13Zr alloy porous materials produced with natural polymers (rice, potato and corn starches, albumin and gelatin), allowed the nutrition and nourishing needed to bone cells survival, proving the osseointegration and osteoconduction features of developed implants.

Os fluxos de comércio exterior do Brasil e do estado de São Paulo são reflexos de condições estruturais de seus respectivos subespaços e de eventos que ocorreram no comércio internacional no período compreendido entre 1999 e 2014. Este período foi marcado por alguns eventos de grande impacto no plano mundial, tais como a ampliação da participação da China no comércio internacional e na divisão internacional do trabalho, além de um intenso ciclo de expansão dos fluxos de comércio internacional, interrompido pela crise norte-americana no ano de 2008, com reflexos mundiais. As exportações brasileiras apresentam uma forte expansão a partir de 1999, acompanhando o crescimento do comércio mundial e a valorização das commodities, proporcionando superávits comerciais que perduram até o ano de 2014.Já o estado de São Paulo,muito embora apresente a maior participação no comércio exterior brasileiro dentre todas as unidades da federação, demonstra uma tendência deficitária, associada à maior participação de insumos produtivos em sua pauta de importação, e também ao mercado consumidor de alto poder aquisitivo, que intensificam os valores das importações num ritmo superior ao crescimento de suas exportações. Já as exportações paulistas, muito embora apresentem maior participação de mercadorias de alto valor agregado, não acompanham o dinamismo do comércio exterior brasileiro. A partir da hipótese de que a presença de condições de fluidez e porosidade diferenciados no território paulista afetam os seus fluxos de comércio exterior, este trabalho busca entender a dinâmica do comércio exterior paulista dentro do recorte temporal especificado (1999-2014), estudando as características dos principais produtos que fazem parte de sua pauta comercial, bem como dos mercados de origem e destino destes fluxos. / The flows of foreign trade in Brazil and the state of São Paulo reflect the unique conditions of their subspaces and the events that occurred in international trade in the period between 1999 and 2014. This period was marked by events of great impact at the world level, such as the expansion of China\'s participation in international trade and also into the international division of labor, as well as an intense cycle of expansion of international trade flows, interrupted by the United State crisis in 2008, with global repercussions. Brazilian exports have shown a strong expansion since 1999, following the growth of world trade and the appreciation of commodities, providing commercial surpluses that last until 2014. The state of São Paulo, although it has the largest share of trade in Brazil\'s foreign market, shows a deficit trend, associated to the higher share of productive inputs in its imports, and also due to the high purchasing power of its consumer market, which intensifies import growth faster than its exports. On the other hand, even though they have a higher share of high value added goods, São Paulo\'s exports dont follow the dynamism of Brazilian exports. Based on the hypothesis that the presence of differentiated fluidity and porosity conditions in the territory of São Paulo affect its foreign trade flows, this work seeks to understand the dynamics of the São Paulo foreign trade within the specified time frame (1999-2014), studying the characteristics of the main products that are part of its trade agenda, as well as the markets of origin and destination of these flows.

A espectroscopia fotoacústica (PA) vem sendo largamente utilizada em diversos ramos de pesquisa, principalmente nas investigações de materiais quanto às suas propriedades ópticas e térmicas, demonstrando a sua vasta versatilidade. No presente trabalho, desenvolveu-se uma câmara fotoacústica de uso geral e uma metodologia baseada na técnica fotoacústica, técnica não intrusiva e não destrutiva, para a determinação da porosidade aberta de membranas vítreas. A porosidade aberta de membranas vítreas está relacionada diretamente à permeabilidade e à eficiência dessas membranas em processos de filtração. Essas membranas foram processadas utilizando-se a técnica de preenchimento e garrafas de vidro, encontradas comercialmente, como matéria-prima. Através da utilização de NaCl como o material inerte, foram processadas membranas com diferentes percentagens de poros. A metodologia fotoacústica desenvolvida neste trabalho teve como base modelos teóricos fotoacústicos tradicionais de análise. Esta metodologia foi capaz de determinar a porosidade aberta das membranas e de distinguí-las quanto as suas superfícies. Os resultados obtidos através da técnica fotoacústica foram comparados com os resultados obtidos por porosimetria de mercúrio (técnica intrusiva e destrutiva) e por ensaios de permeabilidade (técnica intrusiva e não destrutiva) com as mesmas membranas. Estas duas técnicas de análise são as usualmente utilizadas em estudos de estruturas porosas. A comparação entre os dados experimentais comprovou a validade dos resultados obtidos com a nova metodologia. Além desta metodologia fornecer a porosidade aberta com relativa facilidade, ela demonstrou ser rápida, não-destrutiva e de baixo custo para cada ensaio nas análises / The photoacoustic (PA) spectroscopy has been used in several research lines, mainly in the investigation of thermal and optical properties related to different materials, showing in this way high versatility. In this work is described the development of a general-purpose photoacoustic cell, and of a methodology based on photoacoustic technique for the determination of the opened porosity of vitreous membranes. The technique is non-intrusive and non-destructive in relation to the membranes. The opened porosity of vitreous membranes is directly related to the permeability and also directly related to the efficiency of these membranes in the filtration processes. Membranes with different percentage of pores were processed by means of filler principle. For this purpose were used glass bottles found commercially as raw material and NaCl as inert material. The photoacoustic methodology developed in this work was based on classical theoretical models found in the literature. This methodology was capable to determine the open porosity of the membranes and to distinguish membranes with different surfaces. The results obtained with the photoacoustic technique were compared with that obtained by means of mercury porosimetry (intrusive and destructive technique) and permeability measurements (intrusive and non destructive technique) with the same membranes. These two techniques are usually used in studies of porous structures. The comparison between the experimental data showed the validity of the results obtained with this new methodology. Moreover, it supplies the opened porosity with relative easiness, in a faster and non-destructive way, and with low cost in the analyses

O saprolito é um corpo geológico constituído pela mistura de minerais primários e secundários resultantes do intemperismo físico e químico, o qual mantém vestígios da estrutura original da rocha. Difere do solo pela evidente filiação litogenética e insignificante atividade biológica. Apesar das definições, no entanto, o limite e a distinção entre solo e saprolito nem sempre são claros, devido a continuidade entre estes corpos em termos de processos hidrológicos e geoquímicos, bem como de suas composições físicas e mineralógicas, o que gera grande confusão nas descrições morfológicas e na organização de informações. Devido ao caráter multidisciplinar das ciências envolvidas no estudo do saprolito e a dedicação parcial de todas elas, há uma grande carência de padronização de termos e procedimentos para sua caracterização e análise. O objetivo geral desta tese é a caracterização de saprolitos desenvolvidos a partir de variadas litologias, no intuito da elaboração de procedimentos para a descrição, classificação e análise de saprolitos. Especificamente objetivou-se avaliar detalhadamente os padrões de alteração física, mineralógica e geoquímica em materiais, influenciados por atributos litológicos relativos a composição mineralo-química e estrutural do material parental. Para tanto foram descritos e amostrados 15 perfis de alteração; compostos por solo, saprolito e rocha, derivados de rochas sedimentares e metamórficas na região Sudeste do Brasil, nos estados de São Paulo e Minas Gerais. As descrições demonstraram que os corpos saprolíticos avaliados podem ser agrupados em quatro tipos morfológicos principais, sendo propostas as seguintes categorias estruturais: contínua, fraturada, fragmentada e terrosa. Dentre todos saprolitos avaliados, aqueles derivados de rochas metamórficas apresentaram maior complexidade morfológica. Deste modo, 9 perfis filiados a xistos e gnaisses foram submetidos a análises físicas, geoquímicas e mineralógicas para avaliação dos processos de alteração e desenvolvimento de sistema de classificação. A composição mineralógica de solos e saprolitos se mostrou semelhante, entretanto, ocorreram dissimilaridades geoquímicas entre estes corpos. Atributos físicos como densidade e porosidade total não demonstraram diferenças significativas entre solo e saprolito, entretanto, ao se considerar isoladamente amostras de saprolito, houve correlação positiva entre a perda de massa e a porosidade total, tornando este último atributo útil `a proposta de classificação de saprolitos. / The saprolite is a geological body constituted by the mixture of primary and secondary minerals resulting of physical and chemical weathering, which retains traces of the original rock structure. It differs from the soil by the evident litogenetic affiliation and insignificant biological activity. Although the definitions, however, the limit and the distinction between soil and saprolite are not always clear, because the continuity between these bodies in terms of hydrological and geochemical processes, as well as their physical and mineralogical compositions, which creates great confusion in morphological descriptions and information network. Due to the multidisciplinary nature of the sciences involved and the partial dedication of all of them in the saprolite investigations, there is a great lack of standardization of terms and procedures for characterization and analysis. The overall objective of this thesis is the characterization of saprolite developed from various lithologies in order to draw up procedures for the description, classification and saprolite analysis. Specifically aimed to evaluate in detail the patterns of physical, mineralogical and geochemical changes in some materials influenced by lithological attributes how the mineralogical and chemical composition, as well as the structure of parental material. For this were described and sampled 15 weathering profiles, composed of soil, saprolite and rock derived from sedimentary and metamorphic rocks in southeastern Brazil, in the states of São Paulo and Minas Gerais. The descriptions shown that saprolite evaluated can be grouped into four main morphological types, proposed the following structural categories: continuous, fractured, fragmented and earthy. Among all evaluated saprolite, those derived from metamorphic rocks showed higher morphological complexity. Thus, 9 affiliated profiles schists and gneisses to have been subjected to physical, geochemical and mineralogical analyzes to evaluate the change processes and to developing the classification system of saprolites. The mineralogical composition of soils and saprolite was similar, however, there were dissimilarities regard geochemical attributes between this bodies. Physical properties such as density and porosity showed no significant differences between soil and saprolite, however, when considered in isolation saprolite samples, there was a positive correlation between weight loss and total porosity, making this last attribute able to integrate the proposed saprolite classification.

Ce travail porte sur le territoire mythique de la frontière entre le Mexique et les États-Unis, à l’aune de la littérature romanesque. Produit d’une histoire conflictuelle, la zone frontalière est au coeur d’une actualité terrible et spectaculaire. La violence des narcos, les milliers de migrants risquant leur vie à travers le désert, les féminicides innombrables et impunis : tout exprime la violence et l’excès. Prenant pour point de départ ce constat d’une réalité extrême et spectaculaire, cette étude montre la complexité d’un lieu mêlant différentes représentations. Ce phénomène est nommé hypertopie. Le corpus romanesque composé d’écrivains étatsuniens (James Carlos Blake, Cormac McCarthy), mexicains (Yuri Herrera, Eduardo Antonio Parra) et plus largement latino-américains (Roberto Bolaño) sert de contrepoint critique à cette hypertopie, conçue comme un débordement romanesque de la fiction sur le réel. L’étude de ces romans dévoile une représentation paradoxale de la frontière, mobile, qui s’efface et disparaît. Le travail définit le « roman total » ou roman de la porosité, capable d’accueillir en son sein une interrogation inquiète face au chaos du monde, contre lequel la littérature tente de faire front. Pour aborder un tel lieu, l’étude se propose une approche non seulement comparatiste (par des emprunts à la géocritique et des références à l’imagologie) mais plus largement interdisciplinaire, croisant géographie, histoire, anthropologie et arts plastiques. / This work focuses on the mythical territory of the border between Mexico and the United States, in terms of novelistic literature. As the product of a conflict history, the border area is at the heart of an actuality terrible and spectacular. The violence of the narcos, the thousands of migrants risking their lives through the desert, the innumerable and unpunished feminicides: every fact expresses violence and excess. Taking as a point of departure this observation of an extreme and spectacular reality, this study shows the complexity of a place mixing different representations. This phenomenon is called hypertopia. The fictional corpus composed of American writers (James Carlos Blake, Cormac McCarthy), Mexicans (Yuri Herrera, Eduardo Antonio Parra) and more broadly Latin American (Roberto Bolaño) serves as a critical counterpoint to this hypertopia, conceived as a romantic overflow of fiction on the real. The study of these novels reveals a paradoxical representation of a mobile border, which disappears and vanishes. The work defines the "total novel" or novel of porosity, able to contain a worried questioning about the chaos of the world, against which literature tries to confront. To approach such a place, the study proposes a method, not only comparatist (by borrowing geocritics and references to the imagology) but more broadly interdisciplinary, crossing geography, history, anthropology and plastic arts.