La biodisponibilité des nutriments lipidiques dépend d'un processus physico-chimique et enzymatique complexe : digestion par les lipases dans l'estomac puis l'intestin, absorption par les entérocytes et transport vers les cellules utilisatrices. L'altération physiologique (nouveau-né, personne âgée) ou pathologique (mucoviscidose, pancréatite) de ce processus réduit la biodisponibilité des acides gras essentiels, indispensables au développement et au fonctionnement des cellules de l'organisme. Ce mémoire présente des stratégies permettant d'améliorer la biodisponibilité des nutriments lipidiques chez l'insuffisant pancréatique, en utilisant les propriétés physico-chimiques des lipides. En effet, elles déterminent des caractéristiques primordiales de l'interface lipidique (superficie, composition), au niveau de laquelle se déroule l'hydrolyse enzymatique. Nos travaux montrent, in vitro dans des conditions proche de la physiologie, que le type de phospholipide entrant dans la composition d'une émulsion de trioléine, ou l'ajout d'un type donné d'acide gras libre dans le mélange lipidique avant l'émulsification, modifie la taille et le potentiel zêta des globules lipidiques, influence l'action des lipases gastrique, pancréatique et stimulée par les sels biliaires, et module l'absorption des acides gras par des cellules Caco-2. Un effet majeur est obtenu avec le lysophosphatidylinositol, rendant ce lipide potentiellement utilisable en nutrition clinique. Il présente un comportement interfacial étonnant (aire moléculaire, compressibilité) et son mécanisme d'action associe des effets indirects (modifications de l'interface lipidique) et directs (interactions avec les lipases).

Procesos hidrodinámicos determinan, en un alto grado la calidad del agua en embalse, sin embargo dichos procesos han sido tradicionalmente olvidados en la gestión de embalse. En esta tesis se presentan evidencias de los principales procesos hidrodinámicos que ocurren en un embalse Mediterráneo a escala de cuenca a través de campañas experimentales y modelización numérica; y su influencia en la dinámica de poblaciones de fitoplancton. Dichos procesos son principalmente la generación de ondas internas o secas y la intrusión del río. La presencia de viento periódico genera secas forzadas, amplificando los modos cercanos al periodo del viento, de manera que modos verticales altos, considerados como raros en la naturaleza, tienden a dominar en el sistema. / Physical processes determine, to a large degree, the ecological response of a reservoir to inflows, outflows and meteorological forcing. This PhD thesis therefore aims to give an assessment of the main physical mechanisms governing Mediterranean reservoirs. The main basin-scale hydrodynamical processes are the generation of seiches and the gravity currents generated by the river inflow. The periodicity of the wind forcing makes that the reservoir responses as a forced harmonic damped oscillator being the natural modes of oscillation close to the forcing period preferably excited; including high vertical modes considered rare in the nature. The fate of the river inflow nutrients input generates horizontal heterogeneities in the community of phytoplankton.

Η παρούσα διατριβή διερευνά την επίδραση των πετρογραφικών παραμέτρων στις φυσικομηχανικές ιδιότητες των οφιολιθικών πετρωμάτων Πίνδου και Βούρινου. Επιπρόσθετα, μελετώνται ορισμένα δείγματα από τα οφιολιθικά συμπλέγματα του Κόζιακα και της ανατολικής Όθρυος και ορισμένα Τριαδικά ηφαιστειακά πετρώματα από την περιοχή του Δομοκού. Tα συλλεχθέντα δείγματα αξιολογούνται για την καταλληλότητά τους ως αδρανή υλικά. Επιπλέον, διερευνάται η καταλληλότητα υγιών υπερβασικών δειγμάτων στη βιομηχανία πυρίμαχων. Στις υπό μελέτη εμφανίσεις πραγματοποιήθηκε λεπτομερής γεωλογική χαρτογράφηση. Ακολούθησε πετρογραφική εξέταση των επιμέρους λιθότυπων και ποσοτικοποίηση των ορυκτολογικών συστατικών τους. Εφαρμόστηκαν σύγχρονες τεχνικές με ηλεκτρονικό μικροσκόπιο σάρωσης, μικροσκόπιο φθορισμού και λογισμικό ψηφιακής επεξεργασίας εικόνας. Διερευνήθηκε επίσης ο τρόπος διάδοσης των μικρορωγμών κατά τη μοναξονική φόρτιση των πετρωμάτων και δόθηκε έμφαση στην πιθανή συμμετοχή αμιαντούχων ορυκτών σε αυτά. Προσδιορίστηκαν οι γεωμετρικές, φυσικομηχανικές, φυσικοχημικές και χημικές ιδιότητες των δειγμάτων και διαπιστώθηκε ότι οι βασικοί λιθότυποι παρουσιάζουν υψηλότερη μηχανική αντοχή από τους υπερβασικούς, ενώ οι τραχίτες έχουν συνήθως μεταβατικά χαρακτηριστικά μεταξύ των δύο παραπάνω κατηγοριών πετρωμάτων. Οι συσχετίσεις μεταξύ των προσδιορισθέντων ιδιοτήτων διερευνήθηκαν με ανάλυση παλινδρόμησης και παραγοντική ανάλυση. Οι ιδιότητες των βασικών και υπερβασικών λιθότυπων τείνουν να βελτιώνονται όσο μειώνεται ο βαθμός εξαλλοίωσης. Εξαίρεση αποτελεί ο δείκτης αντίστασης σε στίλβωση, ο οποίος τείνει να βελτιώνεται αυξανομένου του βαθμού υδροθερμικής μεταμόρφωσης. Για τους δολερίτες διατυπώθηκαν δύο νέοι μικροπετρογραφικοί δείκτες, ο δείκτης αντοχής (Ips) και ο δείκτης αντικατάστασης (Irep), οι οποίοι αποτελούν ποσοτική έκφραση των πετρογραφικών μεταβολών που λαμβάνουν χώρα κατά την εξαλλοίωση. Για τους υπερβασικούς λιθότυπους εισήχθηκε ο λόγος OOS, ο οποίος εκφράζει το βαθμό διατήρησης των πρωτογενών ορυκτών κατά τη σερπεντινίωση. Για τον προσδιορισμό του βαθμού εξαλλοίωσης των υπερβασικών πετρωμάτων εισήχθηκε ο δείκτης ευκίνητων στοιχείων (Im). Οι υπό μελέτη λιθότυποι είναι κατάλληλοι για χρήση ως αδρανή σκυροδεμάτων, κονιαμάτων, οδοποιίας, σκύρων σιδηροτροχιών, φίλτρων και βράχων θωράκισης, με εξαίρεση τους έντονα σερπεντινιωμένους και τεκτονισμένους χαρτσβουργίτες και τους τραχίτες. Ακόμη, τα υγιή υπερβασικά δείγματα είναι κατάλληλα για χρήση ως πρώτες ύλες στη βιομηχανία πυρίμαχων. / The present thesis aims at investigating the influence of petrographic factors on the physicomechanical properties of the Pindos and Vourinos ophiolitic rocks. Samples were also collected from the Koziakas and eastern Othrys ophiolitic complexes, as well as from an exposure of Triassic volcanic rocks near the Domokos locality. The evaluation of the collected samples for their suitability as aggregates is attempted. In addition, selected ultrabasic samples are evaluated for their suitability in refractory industry. The studied areas were thoroughly mapped. The petrographic characteristics of each lithotype were examined and their mineralogical composition was quantified. Modern techniques were also applied, using scanning electron microscopy and fluorescent microscopy, in combination with digital image analysis. Additionally, the microcrack propagation during uniaxial compression was investigated, as well as the potential existence of asbestiform minerals in each sample. The geometrical, physicomechanical, physicochemical and chemical properties were determined for each rock sample. The basic lithotypes have higher strength than the ultrabasic. The trachytes usually have characteristics transitional between the basic and ultrabasic lithotypes. The interrelationships between the various properties were examined using regression and factor analysis. The properties of the basic and ultrabasic lithotypes tend to improve when the degree of alteration decreases. Exceptionally, the polishing resistance tends to increase with an increasing degree of hydrothermal metamorphism. Two new micropetrographic indices were proposed for the dolerites, the micropetrographic strength index (Ips) and the replacement index (Irep). These indices reflect and quantify petrographic transformations which take place during alteration. The ratio OOS was introduced for the ultrabasic samples, which reflects the degree of preservation of the primary mineral phases during serpentinization. Additionally, the index of mobile elements (Im) was introduced in order to quantify the degree of alteration of ultrabasic rocks. The studied rock types are suitable for the production of aggregates for concretes, mortars, road construction, railway track ballast, filters and armourstone. The only unsuitable samples are the intense serpentinized and tectonized harzburgites and the trachytes. In addition, the fresh ultrabasic samples can be used as raw materials in the refractory industry.

Made available in DSpace on 2016-08-15T20:31:28Z (GMT). No. of bitstreams: 1 JovilmaMSM_DISSERT.pdf: 612035 bytes, checksum: f31dff20b37dda80ae55980620cc7d0e (MD5) Previous issue date: 2016-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The most popular type of cheese in the Seridó region are coalho and butter cheese, whose manufacturing process favors the microbial spoilage of such products and the variation in the composition thereof. Faced with the economic importance of these cheeses, aimed to evaluate the production conditions and the microbiological and physicochemical quality of coalho and butter cheese produced in the Seridó/RN region. To this end, we applied a checklist in five artisanal dairies, to evaluate the sanitary conditions in which these cheeses were produced, as it was also done training, the implementation of Good Manufacturing Practices and monitoring of corrective measures. Furthermore, we conducted microbiological testing for coliforms at 35 and 45°C in milk, cheese, water and utensils samples; total mesophilic bacteria in milk samples; Staphylococcus spp. In cheese and utensils samples; and Salmonella sp. In cheese samples, in total, there were 30 samples of each item analyzed at each dairy. Additionally, we carried out physicochemical analysis (humidity, ashes, lipids, pH, acidity, chlorides content and color) in five coalho cheese samples and in five butter cheese samples. The results showed a high percentage of non-conformities in all establishments analyzed. During the diagnosis the count of mesophilic bacteria in milk was higher than the recommended legislation, as well as coliforms at 35 ° C and 45 ° C in water samples. As for the coalho and butter cheese on both detected the presence of Salmonella sp. at diagnosis. High counts were also observed for the samples utensils. After the implementation of GMP in artisanal dairies observed increase in compliance percentages in items work environment hygiene and food handling , which resulted in the improvement of butter cheese processing conditions through significant reduction (p<0.05) coliforms at 35 °C and 45 °C. In this cheese as the coalho cheese, it observed absence of Salmonella sp. the samples after the implementation of GMP. On the subject of the physicochemical aspects, the chees samples showed variation of standards between the different producers in the same region, however they are within the parameters establishments by law. Given these results emphasize the importance of the implementation of Good Manufacturing Practices to improve the microbiological quality of artisan cheeses. What about the physical and chemical parameters was shown that the form of craft manufacturing while providing the preparation of cheeses with different constituents, ensures the compliance of these products with the legislation. / Os queijos mais populares na região Seridó são os queijos de coalho e manteiga, cujo processo de fabricação favorece a contaminação microbiológica desses produtos e a variação na composição dos mesmos. Diante da importância econômica, objetiva-se avaliar as condições de produção, bem como a qualidade microbiológica e físico-química dos queijos de coalho e de manteiga produzidos na região Seridó/RN. Para tanto, foi aplicado um check list em cinco queijarias artesanais, visando avaliar as condições higiênico-sanitárias de produção dos queijos, como também foi realizado um treinamento, a implantação de Boas Práticas de Fabricação e acompanhamento das medidas corretivas. Além disso, foram realizadas análises microbiológicas de coliformes a 35º e 45° em amostras de leite, queijos, água e utensílios, contagem de bactérias mesófilas no leite, Staphylococcus spp. nos queijos e utensílios e Salmonella sp. nos queijos, totalizando 30 amostras de cada item analisado de cada queijaria artesanal. Foram também realizadas análises físico-químicas (umidade, cinzas, lipídios, pH, acidez, teor de cloretos e cor) em cinco amostras de queijo de coalho e em cinco de queijo de manteiga. Os resultados encontrados mostraram um elevado percentual de não conformidades em todos os estabelecimentos analisados. Durante o diagnóstico a contagem de bactérias mesófilas no leite foi superior ao recomendado à legislação, assim como a contagem de coliformes a 35°C e 45°C nas amostras de água. Quanto aos queijos de coalho e manteiga em ambos foi detectada a presença de Salmonella sp. no momento do diagnóstico. Contagens elevadas também foram observadas para as amostras de utensílios. Após a implantação das BPF nas queijarias artesanais observou-se aumento das porcentagens de conformidades nos itens higiene do ambiente e manipulação de alimentos, o que refletiu na melhoria das condições de processamento do queijo de manteiga através da redução significativa (p<0,05) de coliformes a 35°C e 45°C. Neste queijo assim como no queijo de coalho, foi observada ausência de Salmonella sp. nas amostras após a implantação das BPF. Em relação aos aspectos físico-químicos, os queijos apresentaram variação na composição química entre os diferentes produtores da mesma região, no entanto se encontraram dentro dos parâmetros estabelecimentos pela legislação. Diante desses resultados enfatiza-se a importância da implantação das Boas Práticas de Fabricação para a melhoria da qualidade microbiológica de queijos artesanais. E em relação aos parâmetros físico-químicos demonstrou-se que a forma de fabricação artesanal apesar de proporcionar a elaboração de queijos com constituintes diferentes, garante a conformidade desses produtos com a legislação

Les pompes sèches primaires dédiées aux procédés de fabrication en microélectronique sont soumises à des environnements très corrosifs de plus en plus oxydants et halogénés (Cl2, F2 et O2). Or pour des raisons mécaniques et économiques, les parties fonctionnelles des pompes sont usinées dans la fonte à graphite sphéroïdale EN-GJS-500-7. La fonte est alors protégée par un dépôt de nickel-phosphore (NiP) chimique. Cette thèse, reprend des études classiques sur la cinétique et le mécanisme de nickelage d'une part, et sur l'optimisation des propriétés mécaniques et la résistance à la corrosion des couches de NiP d'autre part. Cependant, le caractère innovant de ce travail repose sur la réalisation de couches NiP sur un substrat en fonte à graphite sphéroïdale.L'étude de la cinétique de nickelage et la caractérisation morphologique des revêtements en fonction du temps de dépôt a montré l'influence de la nature chimique du substrat. Les sphères de graphite affleurantes à la surface du substrat n'étant pas catalyseur du nickel chimique, provoque des défauts dans le revêtement, dommageables pour la conformité du dépôt. Il a été montré qu'une polarisation cathodique de la surface du substrat pouvait, dans les premiers instants du dépôt, amorcer le nickelage à l'aplomb des sphères de graphite.Une relation entre la microstructure des dépôts en fonction des traitements thermiques subis et des propriétés mécaniques des couches de NiP a été mise une évidence. Les dépôts NiP amorphes présentent une faible dureté et un comportement ductile tandis que les dépôts cristallisés possèdent une dureté élevée et un comportement fragile. Ces dépôts ont une bonne tenue à la corrosion en milieux halogéné lorsqu'ils sont intacts. Actuellement, au niveau industriel, les dépôts les plus fragiles sont choisis, bien qu'ils présentent une résistance à la corrosion plus faible : en effet, la durée de vie des pompes est alors supérieure car les effets de grippage sont atténués.Mots-clés : nickel chimique, résistance à la corrosion, fonte à graphite sphéroïdale, caractérisation physico-chimique, couches minces, durabilité mécanique / Primary dry pumps dedicated to manufacturing processes in microelectronics are subjected to highly corrosive environments that are increasingly oxidizing and halogenous (Cl2, F2 and O2). However, for mechanical and economic reasons, the functional parts of the pumps are machined in EN-GJS-500-7 spheroidal graphite cast iron. The cast iron is consequently protected by a nickel-phosphorus chemical deposit. This thesis is based on classical studies on the kinetics and the nickel-plating mechanism on the one hand, and on the optimization of the mechanical properties and corrosion resistance of the NiP layers on the other hand. The innovative nature of this work is based on the production of NiP layers on a spheroidal graphite cast iron substrate.The study of the kinetics of nickel-plating as well as the morphological characterization of coatings as a function of the deposit time showed the influence of the chemical nature of the substrate. The flush graphite spheres on the surface of the substrate being not a catalyst for the chemical nickel, they can cause defects in the coating and a loss of compliance. It has been shown that a cathodic polarization of the surface of the substrate, in the first moments of the deposit, could initiate the nickel-plating right on the graphite spheres.A relationship exists between the microstructure of the deposits as a function of the thermal treatments undergone and the mechanical properties of the NiP layers. The amorphous NiP deposits have a low hardness and a ductile behavior while crystallized deposits have a high hardness and a brittle behavior. These deposits have a good resistance to corrosion in halogenated environments when they are intact. Actually, at the industrial level, the most brittle deposits are chosen, although they have a lower corrosion résistance: indeed, the service life of the pumps is higher because the seizing effect are minimized.Keywords: electroless nickel, resistance to corrosion, spheroidal graphite cast iron, physicochemical characterization, thin layers, mechanical durability

Les maladies ostéoarticulaires représentent environ 10% de l’ensemble des pathologies identifiées en France chaque année. Ces maladies inflammatoires et dégénératives des articulations sont pour la plupart consécutives au vieillissement ou à un traumatisme et évoluent vers l’usure des cartilages, d’où un handicap sévère. Comme aucun traitement ne permet la réparation totale du tissu cartilagineux, la recherche médicale développe des techniques d’ingénierie tissulaire. Ces techniques utilisent des substrats polymériques et des cellules souches qui sont « contraints » de se développer pour former du tissu cartilagineux. Cependant, ces techniques ne peuvent pas encore être utilisées à l’échelle d’une articulation complète car il n’est pas possible de reproduire ex vivo à grande échelle la structure et les propriétés mécaniques et physicochimiques du cartilage articulaire. Dans ce contexte, les travaux de cette thèse ont permis de développer des matériaux polymères capables d’être implantés à l’échelle macroscopique dans les articulations pathologiques afin de combler l’usure des cartilages. Pour se faire, de nouveaux biomatériaux - hydrogels p(HEMA) - ont été obtenus en contrôlant le caractère hydrophile des hydrogels p(HEMA) au cours de leur synthèse chimique en présence de différents co-monomères (acide acrylique, acrylamide, acrylate d'éthylène et acrylate de butyle). Partant de là, les propriétés physicochimiques, mécaniques et tribologiques de ces nouveaux hydrogels ont été optimisées afin d’obtenir des propriétés similaires à celles du cartilage articulaire sain. Ensuite, la libération contrôlée de médicaments par ces hydrogels a été étudiée afin de minimiser les risques inflammatoires lors de leur utilisation en ingénierie tissulaire du cartilage articulaire. / Osteoarticular diseases re present approximately 10% of all diseases identified in France each year. These inflammatory and degenerative joint disease are mostly consecutive with age or injuries and the wear progress of cartilage, resulting in severe disability. Because no treatment will total repair the cartilage tissue, medical research is developing techniques based on tissue engineering. These techniques use polymer substrates and stem cells that are "forced" to develop into cartilage tissue. However, these techniques cannot be used across a run articulation because Il is not possible-to replicate ex vivo a large-scale structure and the physicochemical and mechanical properties of articular cartilage. In this context, the purpose of this thesis is to develop polymer materials that can be implanted at the macroscopic level in the joints disease that will fill the wear of the cartilage. To do so, new biomaterials - hydrogels p (HEMA)- were obtained by controlling the hydrophilic nature of hydrogels p (HEMA) during their chemical synthesis in the presence of various co-monomers (acrylic acid, acrylamide, acrylate ethylene and butyl acrylate). From there, physicochemical, mechanical and tribological properties of these novel hydrogels have been optimized to obtain similar properties to those of healthy articular cartilage. Then, the controlled release of drugs from these hydrogels was studied to minimize inflammatory when used in tissue engineering of articular cartilage.

Le présent travail rentre dans le cadre du projet Hubert-Curien Tassili (PHC) entre l’université de Mostaganem et l’université de Perpignan, c’est une thèse de doctorat en cotutelle qui a comme objectif la contribution à l’étude de la contamination des eaux et des sédiments de l’Oued Chéliff et de ses deux affluents Oued Rhiou et Oued Mina. Cette étude a été abordée par un prélèvement saisonnier réalisé pendant deux périodes distinctes période humide et période sèche au niveau de 15 stations le long des cours d’eau. La qualité des eaux et des sédiments des cours d’eau a été déterminée par l’analyse des paramètres physico-chimiques, des métaux et des traceurs fluorescents.Les résultats obtenus ont montré une forte contamination en conductivité, DCO, DBO5 pendant la période humide et en Cl- et MES pendant la période sèche. Les résultats des métaux ont montré des concentrations importantes en Al, Fe et Ni particulièrement au niveau de l’Oued Chéliff et son affluent Oued Rhiou en période sèche. Cependant, Oued Mina présente des valeurs élevées de Li et de Sr. Les concentrations de types tryptophane, tyrosine et indole montrent des valeurs élevées au niveau des stations de rejets. L’évaluation de la qualité des sédiments de l’Oued Chéliff a montré que l’Oued Chéliff et son affluent Oued Rhiou sont caractérisés par la présence de fortes concentrations de Al, Mn, Fe, Cr, Ni, Pb pendant les deux périodes.Cette étude nous a permis de déduire que la qualité de l’eau et des sédiments de l’Oued Chéliff et de ses deux affluents a été altérée par les activités anthropiques et les phénomènes naturels. / The present thesis was carried out in co-tutelle between University of Mostaganem (Algeria) and University of Perpignan Via Domitia (France), it was partially funded through a PHC TASSILI project (15MDU937). It aims to study the quality of waters and sediments of Cheliff river and its two important tributaries Oued Rhiou and Mina rivers. During this work, seasonal samplings were performed for both water and sediment in 15 different stations along the watercourses during wet and dry.In order to evaluate the water and sediment quality of watercourses, several parameters were analyzed: the physicochemical parameters, fluorescence amino acids and trace metals. The study reveals a significant organic contamination along the watercourses with high concentrations of conductivity, COD, BOD5 during the wet period and Cl-, TSM during the dry period. The results of trace metals showed high concentrations of Al, Fe and Ni, particularly along the Cheliff and Oued Rhiou rivers during the dry period. On the other hand, Mina river presented high concentrations of Sr and Li. The presence of tryptophan like, tyrosine like and indole like in water samples revealed the impact of untreated urban discharges rejected into watercourses. Another part of the work is devoted to assess the quality of sediments of Cheliff river and its tributaries. The results show that the Cheliff river and its tributary Oued Rhiou are characterized through the presence of high concentrations of Al, Mn, Fe, Cr, Ni, Pb, during wet and dry periods. The present study has shown that the Cheliff river and its tributaries were strongly impacted by anthropogenic pollution and natural phenomenon.

Bien que dits « inoxydables », les aciers inox peuvent être sujets à diverses formes decorrosion localisée telles que la piqûration. La formation de piqûres, nuisible à l’aspect et à l’intégritéstructurelle du matériau, est notamment contrôlée par les propriétés du film passif protecteur qui seforme à la surface des inox. De nombreuses études ont été menées sur les mécanismes de piqûration desurfaces modèles préparées au laboratoire. Cette thèse, au contraire, étudie les relations entre lespropriétés physico-chimiques et électroniques, d’une part, et la résistance à la corrosion par piqûres,d’autre part, de films passifs formés sur des inox par des finis de surfaces industriels.Les propriétés des films passifs ont été caractérisées par des méthodes variées, utiliséesclassiquement ou de façon plus originale : multi-piqûres et transitoires électrochimiques pour lapropriété d’usage, XPS et SDL pour la chimie de surface, spectroscopie d’impédance électrochimique,chrono-ampérométrie et photoélectrochimie pour les propriétés semi-conductrices des films.Il a été montré que la résistance à la piqûration des finis industriels pouvait valablement êtredéterminée par la méthode des transitoires électrochimiques et par la multi-piqûres, utiliséesauparavant pour les seules surfaces modèles. Par ailleurs, l’analyse comparée des résultats depiqûration et de ceux d’XPS et SDL a mis en évidence que la composition chimique des films passifsne suffit pas à rendre compte des différences de résistance à la piqûration des différents finisindustriels testés. En revanche, l’analyse des propriétés semi-conductrices des différents films passifs apermis de proposer des explications à ces écarts de comportements en corrosion localisée, confirmantque structure et taux de défauts du film passif sont deux paramètres clef de la résistance à la corrosionpar piqûres des films passifs.Enfin, une amélioration du comportement en piqûration des surfaces industrielles a pu êtremise en évidence, soit après un traitement court de ces dernières en milieu nitrique acide, soit àl’application aux échantillons d’un balayage en potentiel en milieu sulfate neutre. / Stainless steels can suffer localized corrosion like pitting corrosion which can damage thestructural integrity of the material. The pit formation is mainly controlled by properties of theprotective layer formed on the stainless steel surface, which is called passive film. Many studies haveexamined pitting mechanism on model surface prepared in the laboratory. This work is dedicated tostudy the relations between physicochemical and electronic properties of industrially processedpassive films and their pitting corrosion resistance.The properties of passive films have been characterized with several methods which can beconventional or in a more innovative way: multi-pitting statistics and electrochemical noise for the useproperty, XPS and SDL for the surface chemistry, electrochemical impedance spectroscopy,chronoamperometry and photo-electrochemistry for semi-conductive properties of the passive films.Multi-pitting statistics and electrochemical transients which were usually used on modelsurfaces have been shown to be accurate for the evaluation of the pitting resistance of industrialsurface finishing samples. Furthermore, the comparison of the results of pitting resistance and of XPSand SDL analyses has shown that the chemical composition of passive films is not sufficient to explainthe difference of pitting resistance behavior among tested industrial passive films. However, the semiconductiveproperties characterizations are able to explain these differences of localized corrosionresistance. They confirm that structuration and defect level are two key parameters of pitting resistanceproperties of passive films.At last, this study highlighted that the pitting resistance of industrial passive films can beimproved by a short nitric acid treatment or by sweep voltammetry in neutral sulfate medium.

Les avancées de la biologie contemporaine, posent de façon nouvelle des problèmes philosophiques anciens. Ceux des rapports entre le vivant et l'inanimé, entre le corps et l'esprit, l'erreur et la vérité, sont les plus évidents. La philosophie de Spinoza, bien que datant du 17e siècle, apporte à ces problèmes des solutions plus pertinentes que la plupart des philosophies plus récentes, développées dans les siècles qui l'ont suivie. En retour, les acquis actuels des sciences physiques et biologiques, notamment des neurosciences cognitives, permettent de porter un nouveau regard sur certaines notions propres à la philosophie de Spinoza, telles que sa «petite physique», la nature cause de soi, la notion de matière, l'essence des choses, les genres de connaissance, qui acquièrent de ce fait un surcroît d'actualité. / Old philosophical problems are raised in renewed ways by advances in biology of today. Most obvious are the problems of relationship between living and non-living, mind and body, error en truth. Spinoza's philosophy, although from 17th century, offers solutions to these problems more relevant than most more recent philosophies. In return, present knowledge from physical and biological sciences, especially cognitive neurosciences, can provide a new look at some specifically Spinozist notions such as his "little physics", Nature as cause of itself, the notion of matter, the essence of a thing, kinds of knowledge, which gain all the more interest from a present day point of view.

A influência da cultivar e da época de colheita na composição físico-química e na qualidade sensorial dos espumantes da Serra Gaúcha, Rio Grande do Sul, elaborados pelo método Champenoise nas safras 2006 e 2007, foi avaliada. As cultivares utilizadas foram Riesling Itálico, Chardonnay e Pinot Noir. As uvas foram colhidas em duas épocas distintas: uma referente ao ponto de colheita definido como ideal (época 1) e outra oito dias após (época 2). Os mostos, os vinhos base e espumantes foram analisados quanto à composição básica conforme a metodologia oficial brasileira. Além disso, nos vinhos base e espumantes foram analisados os elementos minerais e compostos aromáticos, através de absorção atômica e cromatografia gasosa, respectivamente. Os espumantes foram avaliados sensorialmente, por uma equipe de degustadores qualificados. Os resultados das análises clássicas dos mostos e vinhos base diferenciaram cultivares e épocas de colheita, nas duas safras estudadas. O mosto de Chardonnay apresentou maior valor de grau º Brix e de álcool potencial. O Pinot Noir se diferenciou pela acidez mais elevada, enquanto que o Riesling Itálico apresentou menores grau Brix e acidez total. Os mostos das uvas colhidas na segunda época apresentaram maiores teores de açúcar, álcool potencial, pH e relação brix/acidez total, e menor acidez. Nos vinhos base, as cultivares Chardonnay e Riesling Itálico apresentaram, respectivamente, maior e menor teor alcoólico e os vinhos das uvas de colheita mais tardia apresentaram menor acidez total. Entretanto, nos vinhos espumantes as análises clássicas não apresentaram diferenças significativas em relação às cultivares e épocas de colheita. Entre os elementos minerais dos vinhos base e dos espumantes correspondentes, o Zn foi único elemento que apresentou diferença significativa entre as cultivares sendo que os vinhos Chardonnay obtiveram os maiores teores. Os vinhos base provenientes das uvas com maior grau de maturação apresentaram, independente da cultivar, maiores níveis de K, Ca, Mg, Mn, Fe, Rb, Li e P e concentrações mais baixas em Cu e Zn. Quanto aos compostos voláteis, maiores quantidades de 2-fenil etanol e dietil succinato diferenciaram os vinhos da cultivar Chardonnay e maiores concentrações de hexanoato de etila e de acetato de isoamila diferenciaram os vinhos da cultivar Riesling Itálico. Já os vinhos Pinot Noir apresentaram teores de 2-metil-1-propanol e 2-metil-1-butanol significativamente superiores às outras variedades. Os vinhos obtidos de uvas colhidas na segunda época apresentaram menores teores de ácido butírico, diferenciando as duas épocas de colheita. Quanto à avaliação sensorial, a variedade Riesling Itálico apresentou maiores notas florais e a Chardonnay maior nota no frutado, tanto no aspecto olfativo quanto no gustativo. Já a Pinot Noir, maior nota vegetal, levedura e pão tostado. Na avaliação final os degustadores não fizeram distinção entre os espumantes Pinot Noir e os Chardonnay, preferindo estes aos de Riesling Itálico, nas duas safras estudadas. Na safra 2007 os degustadores preferiram os espumantes das uvas da primeira época de colheita, enquanto na safra 2006 não foi observada diferença entre as épocas de colheita. O presente trabalho contribuiu para a identificação dos principais constituintes e descritores que determinam a distinção e a tipicidade dos vinhos espumantes da Serra Gaúcha. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-05T16:36:15Z No. of bitstreams: 1 Tese Julio Meneguzzo.pdf: 2072769 bytes, checksum: 3d08ddab08ef5d3acf5e35ed8d16ab59 (MD5) / Made available in DSpace on 2014-06-05T16:36:15Z (GMT). No. of bitstreams: 1 Tese Julio Meneguzzo.pdf: 2072769 bytes, checksum: 3d08ddab08ef5d3acf5e35ed8d16ab59 (MD5) / The influence of cultivar and harvest date on physico chemical composition and sensory quality of sparkling wines from Serra Gaúcha, Rio Grande do Sul, produced by the Champenoise method for crop years 2006 and 2007 were evaluated. The cultivars were Riesling Italico, Chardonnay and Pinot Noir. The grapes were harvested at two different times: one related to the harvesting point defined as ideal (season 1) and another eight days after (time 2). Musts, base wines and sparkling wines were analyzed based on the basic composition as the official Brazilian methodology. In addition, the base wines and sparkling wines were analysed the mineral elements were analyzed and aromatic compounds by atomic absorption and gas chromatography, respectively. Sparkling wines have been evaluated by a team of qualified tasters. The results of the classical analysis of musts and base wines differentiated cultivars and harvest times in the two seasons studied. The Chardonnay must showed higher brix value and potential alcohol. The Pinot Noir has distinguished by higher acidity, while the Riesling Italico had lower Brix and total acidity. The musts of grapes harvested in the second season showed higher levels of sugar, potential alcohol, pH and the realation Brix/total acidity and lower acidity. In the base wine, the varieties Chardonnay and Riesling Itálico were respectively higher and lower alcohol content and wine grapes harvested later showed lower acidity. However, in the sparkling wines the classic analysis showed no significant differences in different cultivars and harvest times. Among the mineral elements of the base wines and sparkling wines corresponding Zn was the only element that showed a significant difference among cultivars is that Chardonnay wines had the highest levels. The base wine from grapes with a higher degree of maturity showed, regardless of cultivar, higher levels of K, Ca, Mg, Mn, Fe, Rb, Li and P and lower concentrations of Cu and Zn. As for the volatile compounds, larger amounts of 2-phenyl ethanol and diethyl succinate differentiated the wines of the cultivar Chardonnay, and higher concentrations of ethyl hexanoate and isoamyl acetate differentiated the wines of the cultivar Riesling Italico. Already Pinot Noir wines showed levels of 2-methyl-1-propanol and 2-methyl-1-butanol significantly higher than other varieties. The wines made from grapes harvested in the second period had lower levels of butyric acid, differentiating the two harvest seasons. As for the sensory evaluation, the variety Riesling Itálico showed higher floral notes and the Chardonnay with highest score on fruity in both the olfactory and the gustatory aspect. As for the Pinot Noir, highest notes aromatic for vegetable, yeast and toasted bread. In the final evaluation the panelists made no distinction between the sparkling wines Pinot Noir and Chardonnay, preferring these to Riesling Itálico, in the two harvests studied. In the season 2007 the tasters preferred the sparkling wines from the grapes of the first harvest season, while the harvest in 2006 there was no difference between harvest seasons. This work helped identify the main components and characteristics that determine the distinguish and tipicity of sparkling wines from the Serra Gaúcha.