A agricultura no Brasil vem se destacando ao longo dos anos como uma das principais atividades econômicas do país. A grande extensão em área, o clima favorável, os investimentos em pesquisa e o aumento da população mundial, vem auxiliando o Brasil a se destacar como celeiro mundial. O grande desafio, portanto, para uma agricultura sustentável é produzir mais sem desmatar os fragmentos ainda existentes de mata original. Para isso, uma das linhas de pesquisa que apresenta grande perspectiva de desenvolvimento é a de pesquisa do uso de fertilizantes que possam promover um suprimento eficiente das exigências nutricionais das plantas respeitando a atual exigência de proteção ao meio-ambiente. Este trabalho apresenta uma metodologia de preparação de óxidos de zinco e manganês hidratados para serem utilizados em formulações de adubos foliares. Utilizou-se para isto o método de precipitação em solução homogênea utilizando o experimento fatorial fracionado saturado Placket - Burman como ferramenta de trabalho. Inicialmente estudou-se a influência de fatores como: tipo de agente precipitante, rotação do agitador mecânico, excesso do agente precipitante e ordem de adição dos reagentes, pois influenciam diretamente na precipitação dos compostos. Estudou-se a distribuição do tamanho das partículas geradas, tomando esta variável resposta como parâmetro para a otimização da metodologia de síntese. Com os resultados obtidos pelo Planejamento Placket - Burman observou-se que o fator excesso de agente precipitante pouco influenciou na variável resposta. A partir dos fatores que mais influenciaram, montou-se nova matriz, agora com planejamento fatorial completo 23. Os fatores que mais influenciaram a variável resposta foram o tipo do agente precipitante, a ordem de adição dos reagentes e rotação do agitador mecânico. Observou-se portanto, com auxilio dos efeitos, a importância de cada fator na variável resposta. Os materiais obtidos foram caracterizados, por meio de difração de raios-X (DRX), analise térmica (TG), espectroscopia de infra-vermelho com transformada de Fourier (FTIR), microscopia eletrônica de varredura (MEV) e espectrofotometria de absorção atômica por chama (AAS). A distribuição do tamanho de partículas foi de 17,01 μm para o hidroxicarbonato de zinco e 5,32 μm para o carbonato de manganês. O hidroxicarbonato de zinco apresentou um teor de zinco em torno de 54,0 %, e, nesta matriz experimental, foi possível chegar a um modelo com bom ajuste para esta síntese. O carbonato de manganês, por sua vez, apresentou as um teor de Manganês em torno de 44,0 % e características adequadas de granulometria para ser utilizado como adubo foliar. / The agriculture in Brazil has been standing out throughout the years as one of the main economical activities of the country. The great extension of the area, the favorable climate, the investments in research and the increase of the world population, has been assisting Brazil to stand out as a world barn. The great challenge, therefore, to a supportable agriculture is to produce more without deforesting the fragments still existing of original forest. That is, one of the methods of research which presents great perspective of development is the research of the use of fertilizer which can promote an efficient supply of the plants nutritional demanding respecting the current environmental protection demand. This work presents a methodology of mustered zinc and manganese oxide preparation to be used in formulations of leaf fertilizer. It was used for it, the precipitation in homogeneous solution method, using the fractioned factorial saturated experiment Packet-Burman as a work tool. Initially, it was studied the influence of the factors as: the type of precipitant agent, rotation of the mechanical shaker, excess of precipitant agent and the order of the addictions of the agents, for they influence directly in the compounds precipitation. It was studied the distribution of the size of the generated particles, taking this changeable response as a standard to a optimizing of the synthesis methodology. With the results obtained by the Planning Placket-Burman it was observed that the factor precipitant agent excess has little influenced the changeable response. From the factors on which most influenced them, it was set a new nuance up, now with a completed factorial planning 2.The factors which more influenced the changeable response were the type of precipitant agent, the order of reagent addiction and the rotation of the mechanic shaker. It was observed, therefore, with the help of the effects, the importance of each factor in the changeable response. The materials obtained were characterized, through the X-Ray diffraction(XRD), thermal analysis(TG), spectroscopy of infrared with transformed of Fourier(FTIR), eletronic microscopy with sweeping (MEV) and espectrophotometry of atomic absortion by flame (ASS). The distribution of the size of particles was 17,01 μm to the hidroxicarbonate of zinc and 5,32 μm to the carbonate of manganese. The hydroxicarbonate of Zinc has presented a level of Zinc around 54,0% and, in this experimental matrix, it was possible to get to a model with a good tunning for this synthesis. The manganese carbonate, on the other hand, has presented a level of manganese around 44,0% and adequate characteristics of particle sizes for being used as foliar fertilizer.

The primary reason for incorporating pigments into plastic materials is to impart the desired colour to finished articles. Some pigments however, may interact with the polymer leading to unexpected deleterious effects. Organic pigments, especially phthalocyanines, are favourable for their brilliant shade but are also well known for causing part distortion or warpage. This causes problems in parts which require good dimensional stability such as crates, containers, trays, caps and closures. Despite that, there are not many published studies on the root cause and mechanism of warpage induced by the pigment. Hence, the objective of this research is to study the influence of such pigments on the dimensional stability, crystallisation behaviour and morphology of polyethylenes in order to have a better understanding on the mechanism of warpage, which could possibly lead to a solution in overcoming this problem.

Apesar de extensa investigação das modificações oxidativas irreversíveis sofridas pelas proteínas in vitro e in vivo, os produtos formados pela oxidação de resíduos de triptofano ainda permanecem apenas parcialmente conhecidos. Recentemente, nosso grupo caracterizou uma ligação cruzada de ditriptofano produzida pela recombinação de radicais hSOD1-triptofanila gerados pelo ataque do radical carbonato produzido durante a atividade peroxidásica da enzima superóxido dismutase humana (hSOD1). Neste trabalho, examinamos se a ligação ditriptofano pode ser formada em outras proteínas, além da hSOD1 e por outros oxidantes, além do radical carbonato. A lisozima da clara do ovo e a beta cristalino bovina foram utilizadas como alvos de oxidação. A lisozima foi utilizada por ser uma enzima pequena (129 aminoácidos) e de estrutura bem conhecida, contendo seis resíduos de Trp. Os resultados mostraram que o radical carbonato, gerado enzimatica ou fotoliticamente, promove a oxidação, dimerização e inativação da lisozima. Os principais produtos de oxidação caracterizados por análise de nano-ESI-Q-TOF-MS/MS foram hidroxi-triptofano e N-formilquinurenina juntamente com um dímero de lisozima (lisozima-Trp28-Trp28-lisozima) e um hetero dímero lisozima-hSOD1 (lisozima-Trp28-Trp32-hSOD1), ambos ligados por uma ligação ditriptofano. Também demonstramos que a irradiação da lisozima com luz UVC leva à formação do dímero lisozima-Trp28-Trp28-lisozima. Em consequência, resolvemos tratar a beta cristalino bovina com radical carbonato gerado fotoliticamente ou com luz UVC, e a proteína também sofreu oxidação, dimerização e agregação. Os principais produtos de oxidação caracterizados por nano-ESI-Q-TOF-MS/MS foram hidroxi-triptofano, N-formilquinurenina, DOPA e um dímero de beta cristalino (βB2-Trp151-Trp151-βB2). A irradiação com luz UVC também levou à formação de um dímero intra-cadeia, caracterizado como βA2-Trp78-Trp81. Quando a beta cristalino foi irradiada com um simulador de luz solar (UVA e UVB) também foi possível observar um dímero, caracterizado como βA2-Trp150-Trp150-βA2. A presença de produtos de oxidação de resíduos de Trp, dentre eles a ligação cruzada ditritpofano, também foi avaliada in vivo, utilizando o cristalino de pacientes que foram submetidos a cirurgia para remoção de catarata. Beta, alfa e gama cristalino foram as principais proteínas identificadas nas frações solúvel e insolúvel do cristalino. A principal modificação pós-traducionais identificada foi deamidação. Um alto conteúdo de resíduos de metionina e triptofano oxidados foram identificados nas proteínas presentes na fração insolúvel. Os principais produtos de oxidação de Trp identificados por nano-ESI-Q-TOF-MS/MS foram quinurenina e N-formilquinurenina. A presença de dímeros covalentes no cristalino com catarata foi confirmada por análises de massas. A completa caracterização desses dímeros (βB1-Trp127-Trp127-βB1 e βB1-Trp193-Trp193-βB1) confirmou que as cadeias polipeptídicas foram ligadas por uma ligação ditriptofano. Em síntese, nossos dados demonstraram que o radical carbonato e a luz UV podem produzir dímeros de ditriptofano em diferentes proteínas. Também, a presença da ligação cruzada de ditriptofano in vivo (catarata humana) foi pela primeira vez detectada. / Despite extensive investigation of irreversible oxidative modifications suffered by proteins in vitro and in vivo, the products formed by oxidation of tryptophan residues remain partially characterized. Our group recently described a ditryptophan cross-link produced by recombination of hSOD1-tryptophanyl radicals generated by attack of the carbonate radical produced during the peroxidase activity of the human superoxide dismutase (hSOD1) enzyme. Here, we examine whether the ditryptophan cross-link can be produced in others proteins besides the hSOD1 and by other oxidants, in addition to the carbonate radical. The egg white lysozyme and bovine beta crystalline were used as targets. Lysozyme was used because it is a small enzyme (129 amino acids) with a well-known structure, containing six Trp residues. The results showed that the carbonate radical, generated enzymatically or photolytically, promotes lysozyme oxidation, inactivation and dimerization. The major oxidation products characterized by nano-ESI-Q-TOF-MS/MS analysis were hydroxy-tryptophan and N-formylkynurenine together with a dimer of lysozyme (lysozyme-Trp28-Trp28-lysozyme) and a hetero dimer hSOD1-lysozyme (lysozyme-Trp28-Trp32-hSOD1), both bound by a ditryptophan cross-link. Also, it was demonstrated that lysozyme irradiation with UVC light leads to the formation of the dimer lysozyme-Trp28-Trp28-lysozyme. In view of these results, we decided to treat beta crystalline bovine with photolytically generated carbonate radical and UVC. Beta crystalline also suffered oxidation, dimerization and aggregation. The major oxidation products characterized were hydroxy-tryptophan, N-formylkynurenine, DOPA and a beta crystalline dimer (βB2-Trp151-Trp151-βB2) by nano-ESI-Q-TOF-MS/MS. Irradiation with UVC light also led to the formation of an intra-chain dimer, which was characterized as βA2-Trp78-Trp81. When beta crystalline was irradiated with a solar simulator (UVA and UVB), it was also possible to observe a dimer which was characterized as βA2-Trp150-Trp150-βA2. The presence of oxidized tryptophan products, including the ditryptophan cross-link, was also evaluated in vivo in the lenses of patients submitted to cataract removal. Beta, alpha and gamma crystalline were the main proteins identified in soluble and insoluble fractions of the lenses. The main post translational modification identified was deamidation. A high content of oxidized methionine and tryptophan residues were identified in proteins present in the insoluble fraction. The main tryptophan oxidation products identified by nano-ESI-Q-TOF-MS/MS were kynurenine and N-formylkynurenine. The presence of covalent dimers in the lenses with cataract was demonstrated by mass analysis. Full MS/MS characterization of the dimers βB1-Trp127-Trp127-βB1 and βB1-Trp193-Trp193-βB1 confirmed that they were linked by a ditryptophan bond. In summary, our data demonstrate that the carbonate radical and UV light can produce ditryptophan dimers in different proteins. Also, the presence of the ditryptophan cross-link was first detected in vivo (human cataract).

Dans cette thèse, nous avons décrit de nouvelles méthodes pour la préparation de polymères et de produits chimiques à partir de ressources renouvelables:Premièrement, nous avons défini une nouvelle méthode de préparation de sulfonamides, utilisant des nitro-aromatiques et des sels de sulfinate de sodium, dans une solution aqueuse de bisulfite de sodium, en tant qu’agent réducteur non toxique. Le produit a été séparé par une simple filtration. La réaction montre une chimio-sélectivité complète, seuls les substrats nitro déficitaire en électrons sont réactifs. Cependant, et contrairement à la littérature, les sels de sulfinate de sodium aromatiques et aliphatiques se sont révélés réactifs dans nos conditions. De plus, nous avons utilisé cette méthode pour préparer de manière écologique le catalyseur de zinc décrit par Karamé et al. et utilisé pour la cycloaddition du dioxyde de carbone avec des époxydes, afin d'accéder aux monomères de polycarbonates pour la préparation de polyuréthane non isocyanate.Ensuite, nous avons étudié la préparation de bis-carbonate de mannitol à partir de mannitol, en utilisant le carbonate de diméthyle comme réactif et comme solvant. Le carbonate de glycérol a été utilisé comme co-solvant en raison de ses propriétés de solubilisation intéressantes. La possibilité de synthèse des monomères diamines entièrement renouvelables a également été étudiée en utilisant des derives des sucres comme la furfurylamine et le 5-méthylfurfural. Nous avons également etudier l’aminolyse du bis-carbonate du mannitol avec la furfurylamine à la température ambiante. De plus, nous avons comparé la stabilité de ce carbonate avec les monomères carbonates commerciaux en utilisant une analyse gravimétrique thermique.Enfin, nous avons préparé le diester de 4,4'-oxydipentanoate de diéthyle à partir de lévulinate d'éthyle par éthérification réductrice sans solvant, catalysée par du triflate de cuivre, en utilisant du tétraméthydisiloxane comme agent réducteur. En outre, nous avons prouvé que ce nouveau monomère était utilisable dans la préparation des polyesters et des polyamides, dans des conditions de polycondensation classiques, en utilisant le propane diol et l’hexaméthylène diamine comme monomères modèles / In this thesis, we describe new methods for the preparation of polymers and chemicals from renewable resources: First we have defined new method for the preparation of sulfonamides, using nitro aromatics and sodium sulfinate salts, in aqueous sodium bisulfite solution as a non toxic reducing agent. The product was separated by simple filtration and the reaction show full chemoslectivity, only electron poor nitro substrates are reactive. However, in contrast with the literature, aromatic and aliphatic sodium sulfinate salts were found reactive under our conditions. In addition, we have used this method to prepare, in a green way, the active zinc catalyst reported by Karamé et al. for the cycloaddition of carbon dioxide with epoxydes, in order to access to polycarbonates monomers for non-isocyanate polyurethane preparation.Then, we have investigated the preparation of high purity mannitol bis-carbonate from mannitol using dimethyl carbonate as a reagent and as a solvent. Glycerol carbonate was used as co-solvent due to its interesting solubilization properties. The possibility of the synthesis of fully renewable diamine monomers was also investigated using furfurylamine and 5-methylfurfural derivated from sugars. We have also uncovered its high reactivity toward uncatalyzed aminolysis with furfurylamine at room temperature. Furthermore, we have compared the stability of this carbonate with existing commercial monomers using thermal gravimetric analysis.Finally, we prepared the diethyl 4,4'-oxydipentanoate diester from renewable ethyl levulinate was prepared by solventless reductive etherification, catalyzed by copper triflate, using tetramethydisiloxane as safe and low-cost reducing agent. Besides, we have proved the usability of this new monomer in the preparation of sustainable polyesters and polyamides, under classical polycondensation conditions, using propane diol and hexamethylene diamine as model monomers

Les méthodes géophysiques non intrusives sont requises pour caractériser la zone vadose, les réservoirs d’hydrocarbures, ou les sites de stockages de CO₂. Nous analysons l’impact d’une injection de CO₂ gazeux sur la conductivité électrique et les propriétés électrocinétiques des roches carbonatées partiellement ou totalement saturées grâce aux méthodes de polarisations provoquée et spontanée. Les données sont analysées au regard au regard de mesures effectuées sur une roche chimiquement neutre, vis-à-vis du CO₂, c’est-à-dire , un grès de Fontainebleau. Nous comparons également nos résultats aux données de la littérature. Le coefficient de couplage électrocinétique est un paramètre clé, dont nous allons étudier la dépendance vis-à-vis de la saturation, sujet hautement débattu de nos jours. En utilisant la méthode de polarisation spontanée, nous étudions les relations entre le coefficient de couplage électrocinétique, la pression capillaire ainsi que la perméabilité relative au sein des roches carbonatées. Un système expérimental a été élaboré pour mesurer simultanément la perméabilité relative, l’indice de resistivité et le coefficient de couplage électrocinétique en écoulement diphasique de type eau-gaz, en fonction de la saturation en azote ou en dioxyde de carbone. Les résultats sont comparés à des modèles théoriques basés sur les approches de Brooks et Corey et van Genuchten, dont les exposants nous permettent d’ajuster les données avec les modèles de pression capillaire avec succès. Les échantillons sont saturés avec des saumures de différentes compositions, dont les ions sont mono- ou divalents et pour lesquelles la force ionique est comprise entre 10⁻⁴ et 10⁰ Mol L⁻¹. La valeur absolue du coefficient de couplage électrocinétique augmente lorsque la force ionique de la solution diminue, ce qui a déjà été observé dans les roches gréseuses. Le potentiel zêta a été calculé en utilisant une version modifiée de l’équation d’Helmholtz-Smoluchowski, qui prend en compte les effets liés à la conductivité de surface. Comme pour le coefficient de couplage, la valeur absolue du potentiel zêta chute lorsque la force ionique augmente. Nous nous intéressons également aux effets liés à une injection de CO₂ et à la dissolution de la calcite sur la valeur de ce potentiel zêta. Enfin, nous utilisons la méthode de polarisation provoquée pour déterminer l’influence de conductivité de l’eau porale sur la conductivité électrique complexe, la chargeabilité normalisée ainsi que le temps de relaxation en milieu carbonaté non saturé. Nous montrons que ces paramètres peuvent être considérés comme des paramètres de polarisation de la double couche électrique lorsque la conductivité de l’eau porale est comprise entre 10⁻³ et 10⁰ S m⁻¹. / Minimally intrusive geophysical methods are required to characterize both the vadose zone of the Earth, hydrocarbon reservoirs and CO₂ sequestration. We investigate the impact of gaseous CO₂ on both electrical conductivity and electrokinetic properties of limestones under saturated and unsaturated conditions, using the spectral induced polarization and the self-potential methods. These data are contrasted with measurements performed on a Fontainebleau sandstone and data from the literature. That said, the dependence of a key parameter, the streaming coupling coefficient, with the saturation remains highly debated. Using the self-potential method, we explore the relationship between the streaming potential coupling coefficient, the capillary pressure curves and the permeability in carbonate rocks characterized by distinct textures. A new core flooding system is used to measure simultaneously both the relative permeability, the resistivity index and the streaming potential coupling coefficient in steady-state two-phase flow conditions as a function of the saturation with CO₂ or N₂. The results are compared with a recently developed theoretical model, which can accommodate either the Brooks and Corey or the van Genuchten models for the capillary pressure curves. Saturation was achieved with monovalent and divalent brines with ionic strength ranging from 1x10⁻³ Mol L⁻¹ to 1x10⁰ Mol L⁻¹. The magnitude of the coupling coefficient increases with decreasing ionic strength similarly to the trend observed for sandstones. The zeta potential has been calculated at full saturation using a modified version of the Helmholtz-Smoluchowski equation that accounts for surface electrical conductivity. Under atmospheric conditions, the magnitude of the zeta potential is decreasing with the increase of the ionic strength. We also investigate the effects of a CO₂ release and the calcite dissolution on the magnitude of the zeta potential. Finally, we use the spectral induced polarization method to determine the pore water conductivity effects on the complex electrical conductivity, the normalized chargeability and the main relaxation time during drainage in a clay free limestone. We also show evidences that these parameters could be considered as polarization parameters of the electrical double layer in the pore water conductivity range 10⁻³ - 10⁰ S m⁻¹.

Doctor of Philosophy(PhD) / Soil Stiffness is an important parameter for any geotechnical engineering design. In laboratory tests it can be derived from stress-strain curves or from dynamic measurement based on wave propagation theory. The second method is a more accurate and direct method for measuring stiffness at very small strains. Until now dynamic measurements have usually been obtained manually from the triaxial test. Attempts have been made to automate the procedure but have apparently failed due to the high level of variability in dynamic measurements. Moreover, triaxial tests of soil can be very lengthy and manual dynamic measurements can be very tedious and impractical for long stress-path tests. In this research a computer program has been developed to automate the stiffness measurement (using bender elements) based on the cross- correlation technique. In this method the program records all the peaks and corresponding arrival times in the cross-correlation signal during the test. The stiffness is calculated and displayed on the screen continuously. The Bender Element enabled to get the small strain shear modulus. An arbitrary “Chirp” waveform of 4 kHz frequency was used for this purpose. Subsequently Bender Element test results were checked by ‘Sine’ waveforms of frequencies 5kHz to 20kHz, as well as by manual inspection of the arrival time. This thesis discusses the method and some of the difficulties in truly automating the process. Finally some results from a number of stress path tests on uncemented and cemented calcareous sediments are presented. Bender elements have been used by many researchers to determine the shear modulus at small strain. Most previous studies have used visual observation of arrival time, which is time consuming and often requires some judgement from the operator. This thesis will describe the use of cross-correlation as a method for automation of Gmax measurement. Cross-correlation has been claimed to be unreliable in the past. However, it will be shown that provided several peaks in the cross-correlation signal are monitored it is possible to follow the variation of Gmax throughout consolidation and shearing. The measurement can be made at regular intervals within the software controlling a stress-path apparatus. Details of the apparatus used and practical considerations including selection of waveform and frequency are discussed. A series of drained cyclic triaxial tests was carried out on artificially cemented and uncemented calcareous soil of dry unit weights 13, 15, and 17 kN/m3 and sheared with constant effective confining stress 300 kPa. Gypsum cement contents of 10%, 20% and 30% of the dry soil weight were used. In addition a series of stress path tests were performed on Toyuora sand samples. Results will be presented for two uncemented and one cemented sand. In addition to the bender elements, all tests had internal instrumentation to monitor axial and lateral strains. Results will be presented for Toyura sand to show that the measurements are consistent with those obtained by other methods. Results will also be presented for carbonate sand subjected to a wide range of stress paths. Finally, results will be presented for the carbonate sand cemented with gypsum. The degradation of Gmax of the cemented soil subjected to variety of monotonic and cyclic stress-paths is presented. Analysis of the results includes assessment of the factors influencing Gmax for uncemented sand. Preliminary analysis indicates that in order of importance these are the mean effective stress, the stress history, void ratio and stress ratio. For cemented sand, Gmax is initially constant and independent of stress path. After yielding the modulus degrades, becoming increasingly stress level dependent and eventually approaches the value for uncemented sand. Factors influencing the rate of degradation are discussed. For the Toyuora sand samples the effects of end restraint on the stress-strain response at small strains were investigated. The conventional method of mounting triaxial specimen has the effect of introducing friction between sample and end platen during a compression test. This inevitably restricts free lateral movement of the specimen ends. Frictional restraint at the sample ends causes the formation of 'dead zones' adjacent to the platens, resulting in non-uniform distribution of stress and strain (and of pore pressure if undrained). On the other hand the specimen with 'free' ends maintain an approximate cylindrical shape instead of barrelling when subjected to compression, resulting in a more uniform stress distribution.

Col. folded map in pocket of v. 1. Includes bibliography.

Bibliography: leaves 137-158 / 158 leaves, [8] leaves of plates : ill., maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology and Geophysics, 1987

The understanding of multiphase flow properties is essential for the exploitation of hydrocarbon reserves in a reservoir; these properties in turn are dependent on the geometric properties and connectivity of the pore space. The determination of the pore size distribution in carbonate reservoirs remains challenging; carbonates exhibit complex pore structures comprising length scales from nanometers to several centimeters. A major challenge to the accurate evaluation of these reservoirs is accounting for pore scale heterogeneity on multiple scales. This is the topic of this thesis. Conventionally, this micron scale information is achieved either by building stochastic models using 2D images or by combining log and laboratory data to classify pore types and their behaviour. None of these capture the true 3D connectivity vital for flow characterisation. We present here an approach to build realistic 3D network models across a range of scales to improve property estimation through employment of X-ray micro-Computed Tomography (μCT) and Focussed Ion Beam Tomography (FIBT). The submicron, or microporous, regions are delineated through a differential imaging technique undertaken on x-ray CT providing a qualitative description of microporosity. Various 3-Phase segmentation methods are then applied for quantitative characterisation of those regions utilising the attenuation coefficient values from the 3D tomographic images. X-ray micro-CT is resolution limited and can not resolve the detailed geometrical features of the submicron pores. FIB tomography is used to image the 3D pore structure of submicron pores down to a scale of tens of nanometers. We describe the experimental development and subsequent image processing including issues and difficulties resolved at various stages. The developed methodology is implemented on cores from producing wackstone and grainstone reservoirs. Pore network models are generated to characterise the 3D interconnectivity of pores. We perform the simulations of petrophysical properties (permeability and formation resistivity) directly on the submicron scale image data. Simulated drainage capillary pressure curves are matched with the experimental data. We also present some preliminary results for the integration of multiscale pore information to build dual-scale network models. The integration of multiscale data allows one to select appropriate effective medium theories to incorporate sub-micron structure into property calculations at macro scale giving a more realistic estimation of properties.

Les exigences environnementales imposent de nombreux défis dans le domaine du traitement des eaux. Ainsi, le concept de " chimie verte " a-t-il été proposé et l'utilisation des produits chimiques " écologiques " est devenue une nécessité. Il est donc d'une importance primordiale d'élaborer des inhibiteurs d'entartrage " verts " afin de combattre les phénomènes d'entartrage qui ont des conséquences désastreuses, voire catastrophiques, dans certaines installations industrielles, comme les circuits de refroidissement des centrales nucléaires. Dans cette étude, l'efficacité de différents inhibiteurs d'entartrage de CaCO3 a été évaluée dans un circuit de refroidissement simulé. En tant qu'inhibiteurs de précipitation de Ca-phosphonates, des homo-, co- et ter-polymères ont également été étudiés en matière de leur efficacité. En fait, l'ajout de ces polymères dans l'eau contenant des phosphonates peut réduire la précipitation du Ca-phosphonates et renforcer l'efficacité d'inhibition de l'entartrage du CaCO3. L'effet synergétique de l'acide polyaspartique (PASP) et de l'acide polyepoxysuccinique (PESA) sur l'inhibition de l'entartrage a été étudié en utilisant à la fois des méthodes statique et dynamique. Les résultats obtenus montrent que l'efficacité inhibitrice du mélange PASP-PESA est supérieure à celle du PASP ou du PESA pris individuellement pour la précipitation de CaCO3, CaSO4 et BaSO4. L'effet de la concentration des inhibiteurs, de la température et de la concentration de Ca2+ ont également été étudié. Par ailleurs, l'analyse par MEB a bien montré la modification de morphologie des précipités en présence du PASP et du PESA. Dans ce travail, on a également étudié les propriétés inhibitrices des ions Cu2+ et Zn2+ dans l'eau potable avec la méthode de Précipitation Contrôlée Rapide (PCR) développée dans le Laboratoire (LIM). Les résultats obtenus montrent que ces ions métalliques sont des inhibiteurs très efficaces à faible concentration. De plus, l'analyse par MEB et IR indiquent que les ces ions peuvent affecter la morphologie cristalline du CaCO3. Par ailleurs, l'influence de la température et du CO2 dissous sur le pouvoir entartrant de l'eau minérale de Salvetat (utilisée comme eau de référence), en présence des ions Cu2+ et Zn2+, a été étudiée expérimentalement. L'inhibiteur idéal serait un composé sous forme solide dont la solubilité serait très faible, mais largement suffisante pour assurer une inhibition totale de l'entartrage. Il pourrait ainsi être mis en contact directement avec l'eau à traiter sans que l'on ait à se soucier de sa concentration qui serait régulée automatiquement par sa solubilité. La synthèse de tels inhibiteurs a été réalisée et leur efficacité a été évaluée durant cette thèse. En fait, les inhibiteurs solides obtenus ont une solubilité de l'ordre de 1,5 mg/L dans l'eau du robinet de Paris et ils donnent une inhibition totale de CaCO3 dans la même eau avec une concentration seulement de 30 ppb (μg/L). De plus, l'introduction de ces inhibiteurs solides peut être réalisée facilement par une cartouche.