Tesis sobre el tema "PO2"

Purpose. The purpose was to examine venous PO2, transcutaneous tissue PO2 (PtcO 2), and VO2max in a normobaric environment following a single HBO2 treatment. Methods. Ten moderately trained (VO2max = 57.6 mL·kg-1·min -1) males volunteered for the study. Baseline testing included measures of VO2max, PtcO2, and anthropometry. Subjects received two HBO2 treatments, which consisted of breathing 95% oxygen at 2.5 ATA for 90 min. Following the first HBO2 treatment (6.0 +/- 1.0 min), subjects performed a VO2max test. Following the second HBO2 treatment, leg and chest PtcO2 and venous PO2 were monitored for 60 min. Results . VO2max, running time, and peak La were not altered (p < 0.05) post-HBO2 treatment. Leg PtcO2 was lower (p < 0.05) and chest PtcO2 was unchanged following the HBO2 treatment compared to baseline values. Venous PO2 was lower in the first 3 min post-HBO2 treatment than subsequent values, but no other differences were found (p < 0.05). Conclusion. The results of this study show that a single HBO 2 treatment at 2.5 ATA for 90 min does not elevate venous PO2, PtcO2, or VO2max in a normobaric, normoxic environment.

L’imagerie fonctionnelle cérébrale détecte les changements hémodynamiques induits par un stimulus pour déterminer les zones d’activation neuronale. Plus particulièrement, l’imagerie BOLD en IRMf détecte les changements d’oxygénation du sang grâce aux propriétés paramagnétiques de la déoxyhémoglobine. L’oxygène n’est donc pas uniquement un substrat énergétique pour le tissu neuronal, il joue également un rôle majeur dans l’imagerie noninvasive du cerveau humain. Au cours de ma thèse, j’ai tout d’abord participé à la mise au point d’une nouvelle technique non-invasive d’imagerie de l’oxygène dans le cerveau d’animaux anesthésiés. Couplant un nouveau senseur phosphorescent de l’oxygène (Finikova et al., 2008) et la microscopie biphotonique, cette approche permet à la fois de cartographier l’oxygène en 3D avec une résolution spatiale et temporelle jusqu’alors inégalée, mais aussi de suivre simultanément l’oxygène et le flux sanguin dans les capillaires cérébraux au repos ou lors d’une activation neuronale (Lecoq et al., 2011). Tirant profit des nouvelles possibilités de cette technique, nous avons alors démontré: • la présence d’un shunt artério-veineux uniquement basé sur la diffusion de l’oxygène. Ce résultat, obtenu chez le rat dans la couche la plus superficielle du bulbe olfactif: la couche du nerf (ONL), confirme que l’oxygène ne diffuse pas uniquement à partir des capillaires et démontre que les artérioles contribuent significativement à l’oxygénation du tissu cérébral. Il démontre également qu’il n’est pas possible de déterminer ni la Po2 capillaire ni la Po2 tissulaire à partir de la Po2 veineuse. • l’existence de transitoires de Po2 associés à chaque globule rouge dans le compartiment capillaire, appelés EATs (erythrocyte-associated transients) (Hellums, 1977; Cabrales and Intaglietta, 2007). En bref, de part leur diamètre supérieur à celui de la lumière d’un capillaire, les globules rouges passent un à un dans la lumière des capillaires, laissant entre eux un espace de plasma. Cependant, la faible solubilité de l’oxygène dans le plasma crée une barrière à la diffusion, ce qui se traduit par une inhomogénéité de la Po2 capillaire: celle-ci est élevée au bord du globule rouge et décroit avec la distance pour atteindre un minimum à mi-distance entre deux globule rouges. Poursuivant l’étude des EATs (Parpaleix et al., 2013), nous avons observé les points suivants: • La Po2 tissulaire dans l’environnement immédiat d’un capillaire peut être déterminée à partir de la Po2 vasculaire à mi-distance entre deux érythrocytes. Ce résultat est intéressant en ce qu’il permettra d’effectuer des mesures non invasives de Po2 tissulaire, utile notamment chez l’animal éveillé. • L’amplitude des EATs est si large (35 mmHg en moyenne) que la Po2 capillaire moyenne ne reflète en rien la saturation en oxygène de l’hémoglobine. • Une empreinte filtrée des EATs vasculaires est détectable dans le tissu (_5 mmHg d’amplitude). • Au cours d’une stimulation neuronale, une diminution de la Po2 capillaire moyenne peut être détectée avant l’hyperémie fonctionnelle, un résultat jusqu’à présent controversé dans le domaine de l’imagerie BOLD en IRMf, mais important en ce que ce dip pourrait être un rapporteur très résolutif de l’activation neuronale. Parmi les questions restant en suspens et pouvant être étudiées finement avec notre approche, j’en citerai une principale: quel est le poids des différents facteurs (métaboliques, présynaptiques ou post-synaptiques) et du flux sanguin dans l’établissement de la Po2 cérébrale au repos?
In humans, functional mapping of brain activity mainly relies on the increase of cerebral blood flow (CBF) triggered by neuronal activation. This neurovascular coupling provides energy substrates such as oxygen and glucose to the activated area. The steady state concentration of oxygen, as well as its dynamics upon neuronal activation, have been investigated with numerous methods, however, none of them provided highly resolute measurements in depth. During my PhD, we combined a phosphorescence quenching approach with two-photon microscopy to detect, in depth and with a micrometer spatial resolution scale, the emission of phosphorescence by PtP-C343, a new oxygen nano-sensor designed for two-photon excitation. We first characterized the technique and then reported two biological results, using the olfactory bulb (OB) glomerulus as a model to study oxygen concentration, at rest and upon odor stimulation. We found an arterio-venous shunt, purely based on diffusion, in the superficial nerve layer of the OB, confirming the role of arterioles in brain oxygenation. Simultaneous measurements of Po2 and blood flow allowed us to reveal the presence of erythrocyte-associated transients (EATs), i.e. Po2 fluctuations that are associated with individual erythrocytes. Pursuing the investigation of EAT characteristics, we found that in capillaries, Po2 at mid-distance between two erythrocytes is at equilibrium with, and thus reports Po2 in the nearby neuropil. Finally, we could observe that even in capillaries, a small oxygen initial dip can be detected prior to functional hyperemia, upon odor activation

Les travaux présentés dans le cadre de cette thèse ont porté sur la modélisation mathématique de la réponse d’une tumeur en traitement par la radiothérapie. Le but étant de fournir aux médecins un outil numérique d’aide pour diagnostiquer le cancer. Comme par exemple, suivre l’évolution du volume de la tumeur pendant et après le traitement, réadapter les stratégies thérapeutiques, etc. Dans un premier temps, nous avons proposé un modèle discret stochastique basé sur une approche multiéchelle. Dans ce contexte, nous nous sommes concentrés sur trois différentes échelles de modélisation tumorale : l’échelle microscopique (les cellules dans un voxel), l’échelle mésoscopique (population de cellules dans un voxel) et l’échelle macroscopique (tissu tumoral), avec des interfaces de transition entre ces trois échelles. Au niveau cellulaire, la description est basée sur des probabilités de transfert de phase dans le cycle cellulaire. À l’échelle mésoscopique, nous représentons les populations de cellules selon les différentes étapes d’un cycle cellulaire. Enfin, à l’échelle macroscopique, la description tumorale est basée sur l’utilisation des images médicales PET FDG. Ces trois échelles existent naturellement : les données biologiques sont collectées au niveau macroscopique mais le comportement pathologique de la tumeur est basé sur un cycle cellulaire anormal à l’échelle microscopique. L’introduction d’une échelle mésoscopique a été essentielle pour réduire l’écart entre les deux extrêmes, en termes de transition entre eux. Nous utilisons le modèle multiéchelle discret pour prédire l’évolution temporelle du nombre de cellules tumorales. Par contre, ce modèle n’est pas bien adapté pour prédire l’évolution du volume de la tumeur. Aussi, avons-nous proposé dans un second temps, un deuxième modèle qui est biomécanique et basé sur une équation d’advection réaction. Enfin, les modèles discrets multiéchelle et biomécanique ont été associés pour former un modèle hybride. En effet, le modèle discret est utilisé pour estimer les trajectoires des pressions partielles d’oxygène dans l’environnement tumoral, ces pressions sont ensuite mises en entrée du modèle continu (biomécanique) pour la prédiction de l’évolution du volume tumoral
The work presented in this thesis focused on the mathematical modeling of tumor response during treatment by radiotherapy. The goal was to provide for doctors a digital tool to help cancer diagnose. For example, monitoring tumor volume during and after treatment, rehabilitating therapeutic strategies, etc. In a first step, we proposed a discrete stochastic model based on a multiscale approach. In this context, we focused on three different scales of tumor modeling :microscopic scale (cells in a voxel), mesoscopic scale (cell population in a voxel) and macroscopic scale (tumor tissue), with transitional interfaces between these three scales. At the cellular level, the description was based on probabilities of phase transfer in the cellular cycle. At the mesoscopic scale, we represented cell populations according to the differents stages of a cell cycle. Finally, on a macroscopic scale, tumor description was based on the use of FDG PET medical images.These three scales naturally exist : the biological data were collected at the macroscopic level but the pathological behavior of the tumor is based on an abnormal cell cycle at the microscopic scale. Introduction of a mesoscopic scale was essential to reduce the gap between the two extremes, in terms of transition between them. We used the discrete multiscale model to predict the temporal evolution of the tumor cells number. On the other hand, this model was not well adapted to predict the tumor volume evolution. Thus, we had proposed a second model which was biomechanical and based on an advection reaction equation. Finally, the discrete multiscale and the biomechanical models had been combined to form a hybrid model. Indeed, the discrete model was used to estimate the oxygen partial pressures trajectories, in the tumor environment. These pressures were then input to the continuous (biomechanical) model for the tumor volume evolution prediction

Human essential hypertension affects over 75 million people in the United States, and can lead to death due to its several serious health complications such as hypertension-related cardiovascular disease. The purpose of this research was to understand how hypertension could cause physiological changes to the microcirculation, specifically the PO2 dependence of oxygen consumption (VO2) in skeletal muscle of normotensive and hypertensive rats. The Spontaneously Hypertensive Rat (SHR) strain was used as the diseased model, and Wistar-Kyoto (WKY) rats were used as controls to conduct this study. The SHR strain develops hypertension between 5-6 weeks after birth with an average systolic blood pressure of 150 mmHg. By arresting blood flow using an objective-mounted inflatable airbag, PO2 measurements were obtained along with an oxygen disappearance curve (ODC), which was used to calculate VO2 over various ranges of physiological PO2 values. PO2 and VO2 curves were analyzed based on Hill’s equation to fit the data and describe the PO2 dependence of VO2. When compared to the healthy Wistar-Kyoto rats, the SHRs exhibited a higher Vmax, or maximum rate of oxygen consumption. The average maximal rate of consumption by the hypertensive animal models could be a consequence of a “mitochondrial uncoupling” or some disconnect in the mitochondrial oxygen consumption and the normal corresponding ATP production. In conclusion, this project demonstrated that in situ muscle tissue from hypertensive and normotensive rats had a PO2 dependence of oxygen consumption over a wide range of physiological PO2 values and the hypertensive rats consumed oxygen at a higher maximal rate.

Abstract PO2 DEPENDENCE OF OXYGEN CONSUMPTION IN SKELETAL MUSCLE OF DIABETIC AND NON-DIABETIC RATS By: Alexander C. Liles A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at the Medical College of Virginia Campus, Virginia Commonwealth University Virginia Commonwealth University, 2017 Advisor: Roland N. Pittman, Ph.D. Department of Physiology and Biophysics Type 2 diabetes mellitus (T2DM) is a major medical problem around the world, affecting nearly 6% of the world’s population. This study was an attempt to better understand physiological changes the disease may cause to the microcirculation and more specifically, to assess the dependence of oxygen consumption in skeletal muscle of a diabetic animal model. The spinotrapezius muscles of Goto-Kakizaki (G-K) and Wistar control rats were used to measure interstitial using phosphorescence quenching microscopy. The G-K rats spontaneously develop T2DM and serve as an appropriate model for the disease in humans. By rapidly arresting blood flow in the tissue and observing the resulting changes, an oxygen disappearance curve (ODC) was created. The ODC was used to calculate oxygen consumption rate (VO2) over the physiological range of PO2 values. The resulting VO2 vs PO2 curves were analyzed using Hill’s equation to fit the data and obtain values of several key parameters to quantitatively describe the PO2 dependence of oxygen consumption. When compared to healthy control rats, the G-K rats exhibited a significantly higher Vmax, or maximum rate of oxygen consumption, compared to the Wistar rats. The two rat sub-strains had similar values for P50, which indicates the PO2 at half maximal consumption. The overall higher maximal rate of consumption by the diseased animals could be explained by some disconnect in the consumption of oxygen by the mitochondria and the normal corresponding production of ATP. In conclusion, it was demonstrated that in situ muscle tissue from both diabetic and non-diabetic rats had a PO2 dependence of oxygen consumption over a wide range of PO2 values and the muscles of diabetic animals consumed oxygen at a higher maximal rate.

Materials used for medical devices are far from ideal for the body, so polymers are applied at the outermost region to counteract the body's natural defences. Component-based failures such as delamination and biocompatibility-based failures such as membrane fouling and degradation still remain a signifi cant challenge. This study focuses on the surface properties and modi cation of polyurethane and silicone rubber as coating material for amperometric sensing devices. E ffective synthesis of polyurethane, as well as surface modifi cation techniques performed on polymers already attached to sensing devices, are proposed. Phase inversion resulted in increased soft segment content on the surface (confi rmed by FTIR with a decreased C=O/C=C ratio). It is proposed that such an optimised polymer surface enhances the yield of further surface modi cation, such as hydroxylation (using potassium peroxodisulphate) and sulphonation (employing sodium hydride, triisobutylaluminium and 1,3 propane sultone). A novel method to generate an SO3-derivatised PU surface was proposed. Additionally, successful synthesis of silicone rubber for induced permeability of H2O2 was demonstrated. The physical and chemical properties of these modifi ed polymers were examined and evaluated via FTIR, SEM, TGA and contact angle measurements. The biocompatibility of modifi ed polymers was confi rmed with retarded protein adsorption; cytotoxicity testing showed that polymers were non-toxic to cells. Steady state amperometry on polymer modifi ed needle-type electrodes showed enhanced performance with surface modifi ed polymers to oxygen and H2O2, both of which are potential biological assay targets. Synthesised Prussian Blue (redox mediator) on platinum surfaces showed that the electrochemical response to H2O2 was increased threefold; and in combination with sulphonated polyurethane, interfering current responses could be successfully eliminated.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O presente trabalho teve por objetivo avaliar os valores de pH, pO2, pCO2 e HCO3- sangüíneos e proteinograma sérico de cabritos da raça Saanen, do nascimento aos quatro meses de idade. Foram utilizados vinte cabritos, filhos de cabras livres do vírus da Artrite Encefalite Caprina (CAEV), cujos partos foram acompanhados. O colostro, obtido da própria mãe, foi oferecido por meio de mamadeira em volume correspondente à 20% do peso corporal, dividido em cinco mamadas, sendo a primeira uma hora após o nascimento e as demais a cada seis horas, até completarem 24 horas. Para a realização do fracionamento eletroforético das proteínas séricas foram obtidas amostras de sangue antes de cada administração de colostro, às 48 e 72 horas e aos 7, 15, 30, 60, 90 e 120 dias. Foram colhidas, ainda, amostras de sangue total para a realização da hemogasometria em todos estes momentos e imediatamente após o nascimento. A eletroforese foi realizada utilizando-se gel de agarose. Os resultados obtidos mostraram que, ao nascimento, os cabritos da raça Saanen apresentaram primariamente quadro de acidose respiratória. As concentrações séricas das frações albumina e betaglobulina aumentaram em função da idade, ao passo que ocorreu declínio da fração alfaglobulina. A concentração das gama globulinas diminuiu após 24 horas da última administração de colostro voltando a aumentar apenas aos 30 dias de idade.
The objective of the present study was to evaluate the blood pH, pO2, pCO2 and HCO3- values, and the serum protein concentrations in Saanen kids from birth to four months of age. The study used 20 kids, borne from CAEV free goats. The kids were fed with colostrum from their own mother, in a total volume corresponding to 20% of their body weight. The whole volume was divided in five parts: the first given one hour after birth; the others in intervals of 6 hours until 24 hours of age. Samples of blood for electrophoretic fractionation were obtained before each colostrum feeding; at 48 and 72 hours; and at 7, 15, 30, 60, 90 and 120 days of life. Blood samples for the hemogasometry were obtained in the same moments and few minutes after birth. The electrophoresis was performed on agarose gel. Results demonstrated that Saanen kids present a metabolic acidosis at birth. The albumin and beta-globulin concentrations raise with the age while the alfa-globulin declines. The gama-globulin concentration decreases 24 hours after the last colostrum feeding and raises again by 30 days of age.

Orientador: Raimundo Souza Lopes
Resumo: O presente trabalho teve por objetivo avaliar os valores de pH, pO2, pCO2 e HCO3- sangüíneos e proteinograma sérico de cabritos da raça Saanen, do nascimento aos quatro meses de idade. Foram utilizados vinte cabritos, filhos de cabras livres do vírus da Artrite Encefalite Caprina (CAEV), cujos partos foram acompanhados. O colostro, obtido da própria mãe, foi oferecido por meio de mamadeira em volume correspondente à 20% do peso corporal, dividido em cinco mamadas, sendo a primeira uma hora após o nascimento e as demais a cada seis horas, até completarem 24 horas. Para a realização do fracionamento eletroforético das proteínas séricas foram obtidas amostras de sangue antes de cada administração de colostro, às 48 e 72 horas e aos 7, 15, 30, 60, 90 e 120 dias. Foram colhidas, ainda, amostras de sangue total para a realização da hemogasometria em todos estes momentos e imediatamente após o nascimento. A eletroforese foi realizada utilizando-se gel de agarose. Os resultados obtidos mostraram que, ao nascimento, os cabritos da raça Saanen apresentaram primariamente quadro de acidose respiratória. As concentrações séricas das frações albumina e betaglobulina aumentaram em função da idade, ao passo que ocorreu declínio da fração alfaglobulina. A concentração das gama globulinas diminuiu após 24 horas da última administração de colostro voltando a aumentar apenas aos 30 dias de idade.
Abstract: The objective of the present study was to evaluate the blood pH, pO2, pCO2 and HCO3- values, and the serum protein concentrations in Saanen kids from birth to four months of age. The study used 20 kids, borne from CAEV free goats. The kids were fed with colostrum from their own mother, in a total volume corresponding to 20% of their body weight. The whole volume was divided in five parts: the first given one hour after birth; the others in intervals of 6 hours until 24 hours of age. Samples of blood for electrophoretic fractionation were obtained before each colostrum feeding; at 48 and 72 hours; and at 7, 15, 30, 60, 90 and 120 days of life. Blood samples for the hemogasometry were obtained in the same moments and few minutes after birth. The electrophoresis was performed on agarose gel. Results demonstrated that Saanen kids present a metabolic acidosis at birth. The albumin and beta-globulin concentrations raise with the age while the alfa-globulin declines. The gama-globulin concentration decreases 24 hours after the last colostrum feeding and raises again by 30 days of age.
Mestre

Vanadium can be found in some iron ores as an impurity. Since vanadium is a valuable alloy element there lies an interest in development of a stable and economic way for extraction of it. For this, knowledge about the thermodynamics behind the V-O system combined with other elements, like Mg, is indispensable. A transitional metal like vanadium exists in multiple valences which makes it difficult to study. When vanadium oxide is mixed with other metal oxides the vanadium tends to concentrate in spinels. To investigate the types of phases formed in the Mg-O-V system at 1873 K and an oxygen partial pressure of 10-11 atm, multiple samples containing MgO and V2O3 in different proportions were equilibrated under these conditions. The samples were examined using SEM/EDS and XRD. A three, one and two phase region were found during analysis. In the three phase region MgV2O4, Mg2VO4 and an unidentified solid solution were found when the fraction of V2O3 was 0,234 and 0,448. In the one phase region only MgV2O4 was found at a V2O3 fraction interval of 0,500-0,530. Lastly in the two phase region MgV2O4 and V2O3 was found within the V2O3 fraction interval of 0,549-0,799. In conclusion when there was a higher amount of V2O3 more vanadium rich spinels were formed until a certain point where the spinel was saturated.
Vanadin finns i vissa typer av järnmalm som ett spårämne. Eftersom vanadin är ett värdefullt legeringsämne finns det ett stort intresse av att hitta ett hållbart och ekonomiskt sätt att utvinna detta. För att göra det krävs kännedom om termodynamiken bakom V-O-systemet kombinerat med andra ämnen som Mg. Övergångsmetaller som vanadin existerar i ett flertal valenser vilket kan göra det svårt att undersöka dem. När vanadinoxid blandas med andra metalloxider tenderar vanadin att samlas i spineller. För att undersöka vilka faser som bildas i Mg-O-V-systemet vid 1873 K och ett syrepartialtryck på 10-11 atm läts en serie prover bestående av olika andelar MgO och V2O3 nå jämvikt under dessa förhållanden. Analys av dessa prover gjordes med SEM/EDS och XRD. Analysen visade att det existerade ett tre-, en- och tvåfasområde i serien. I trefasområdet hittades MgV2O4, Mg2VO4 och en oidentifierad fast lösning vid V2O3- fraktionen 0,234 och 0,448. I enfasområdet hittades MgV2O4 vid V2O3-fraktionen 0,500-0,530. Till sist hittades MgV2O4 och V2O3 i tvåfasområdet vid V2O3-fraktionen 0,549-0,799. Utifrån detta drogs slutsatsen att mer vanadinrika spineller bildades då fraktionen V2O3 ökar till en viss gräns efter vilken spinellfasen blev mättad.

Nous avons etudie les proprietes associees aux ondes de densite de charge dans les bronzes quasi-bidimensionnels (po#2)#4(wo#3)#2#m (m=4, 5, 6, 7, 10, 11 et 12). Ces composes subissent des transitions de peierls a des temperatures t#p vers un etat d'onde de densite de charge caracterise par une distorsion periodique de reseau couplee a une modulation de la densite electronique. La chaleur specifique a ete mesuree pour les composes 4m entre 1,7k et 300k. Nous avons obtenu des termes lineaires en temperature anormalement eleves et qui augmentent avec m. Les temperatures de debye se situent autour de 250k et diminuent lorsque m augmente. Ce comportement pourrait etre du a la diminution de la liaison metallique ou (et) a l'augmentation du caractere bidimensionnel quand le parametre m croit. Des oscillations quantiques shubnikov-de haas et de haas-van alphen ont ete observees dans les composes m=4 et m=6 lors de mesures de magnetoresistance (m=4 et m=6) et de couple magnetique (m=6) effectuees a tres basse temperature et sous fort champ magnetique. Nous avons attribue ces phenomenes a l'existence de petites poches cylindriques subsistant sur la surface de fermi dans l'etat onde de densite de charge, plus petites pour le compose m=6 que pour le compose m=4: la surface de fermi est plus detruite dans le compose m=6 que dans le compose m=4. Le caractere de basse dimensionnalite pourrait donc augmenter avec m. Enfin, nous avons mesure la resistivite electrique des composes 10m2 en fonction de la temperature entre 4k et 800k. Cette etude nous a permis de differencier les composes a petit m des composes a grand m: contrairement aux premiers, dans le domaine des basses temperatures, les seconds ont une resistivite qui decroit a temperature croissante. Nous avons attribue l'augmentation en fonction de m de la resistivite a 300k (p(300k)) et du rapport de resistivite p(300k)/p(4k) a l'augmentation des interactions electrons-electrons via la diminution du nombre moyen d'electrons de conduction par atome de tungstene. D'autre part, nous pensons que l'absence d'anomalie tres marquee, caracteristique d'une transition de peierls, pour la plupart des composes a grand m, est due a des phenomenes de desordre empechant l'apparition d'un ordre a grande distance dans l'etat onde de densite de charge

L’amélioration des performances du combustible nucléaire nécessite, aussi bien en régime nominal que lors de rampes de puissance ou de transitoires accidentels, d’être en mesure de maîtriser les effets délétères induits par la réactivité chimique des produits corrosifs (générés par la fission) susceptibles de provoquer des ruptures de gaine. Dans cet objectif, ce travail vise à maîtriser le potentiel d'oxygène de fonctionnement du combustible dans un domaine stabilisant les formes non corrosives de l’iode, par l’usage in-situ de systèmes tampons d’oxydo-réduction appropriés. En fonctionnement nominal, le potentiel en oxygène est assez proche de celui imposé par le tampon (MoO2/Mo). Par conséquent, le premier objectif de ce travail a été de clarifier la thermochimie (solubilité et spéciation dans UO2) du couple (MoO2/Mo). Nous avons étudié la transition MoO2 ⇌ Mo dans UO2 en fonction de la pO2 et de la température, par spectroscopie d'absorption des rayons X (XAS) in situ au synchrotron KARA (Allemagne). Nous montrons que les réactions d’oxydation du molybdène sont toujours possibles thermodynamiquement, quelles que soient les conditions de température mais avec une cinétique lente à 800°C. La vitesse d’oxydation augmente avec la température. De plus, la solubilité de Mo dans UO2 a été mesurée par SIMS (spectrométrie de masse des ions secondaires) et EPMA (microsonde électronique). Nous proposons une limite de solubilité de l’ordre de10-4 mol Mo/mol U, soit 0,01 % m de Mo/UO2. Ensuite, le niobium, sous ses formes redox Nb2O5/NbO2, a été identifié comme un candidat prometteur de par ses propriétés physico-chimiques et neutroniques. La première étape a consisté à préparer des céramiques UO2 contenant le couple tampon redox. Un procédé de fabrication spécifique du combustible UO2 tamponné, dopé par le couple (Nb2O5/NbO2), a été développé afin de préserver les deux formes oxydo-réductrices du tampon oxygène dans les pastilles lors du frittage.Ce processus a été également validé pour UO2 dopé par le couple (MoO2/Mo). Nous avons aussi montré quel e tampon (Nb2O5/NbO2) introduit initialement se transformait lors du frittage en (UNb2O7/NbO2),présentant un équilibre très proche de celui du tampon initial et donc apte à remplir le rôle de tampon depO2 dans le domaine visé. Ensuite, l’objectif final a été la validation de l’effet tampon lié à l’ajout du couple(Nb2O5/NbO2) dans UO2. Nous avons donc d’abord étudié par diffraction des rayons X à haute résolution et haute température (HR HT XRD) et par diffraction des neutrons (DN) la variation du paramètre de maille de la matrice UO2 fluorite en présence du couple oxydo-réducteur qui va agir comme un tampon local pour stabiliser la pO2 au sein du système et la stœchiométrie de la matrice UO2+x. Nous montrons également que le système U-Nb-O présente de nombreuses phases ternaires incluant les états d'oxydation Nb4+ etNb5+, toutes stables sur un domaine étroit de pO2. Ainsi, ces différentes phases ternaires participent à des systèmes tampons, qui permettent de réguler les perturbations oxydo-réductrices pouvant être imposées au matériau sans modification notable de la stœchiométrie du combustible (stabilité du paramètre de maille). Ensuite, les pastilles UO2 élaborées avec le couple tampon Nb2O5/NbO2 ont été implantées avec des ions césium, iode, molybdène et tellure dans une couche superficielle (environ 1 μm). La spéciation de ces espèces a été caractérisée par spectroscopie d'absorption des rayons X (synchrotron KARA)
Improvement of nuclear fuel performances requires reducing the stability of corrosion fission gas, in particular the speciation of potentially corrosive fission products (Cs, I, Te). Doping uranium dioxide with an oxydo-redox buffer couple is the improvement axis considered in this work. It aims at improving redox buffer couple effect on pO2 (oxygen partial pressure) and their impact on properties of speciation of fission products in UO2. Actually, in typical nominal operation, the oxygen potential is quite close to that imposed by the (Mo/MoO2) buffer. The first objective of this work was to clarify the thermochemistry (solubility and speciation in UO2) of the (Mo/MoO2) couple. We studied the MoO2 ⇌ Mo transition in UO2 as a function of pO2 and temperature by X-ray Absorption Spectroscopy (XAS) in situ at the KARA synchrotron (Germany). We show that the oxidation reactions of molybdenum are always thermodynamically possible, whatever the temperature conditions but with a slow kinetics at 800°C. The oxidation rate increases with temperature. In addition, the solubility of Mo in UO2 was measured by SIMS (Secondary Ion Mass Spectrometry) and EPMA (Electron probe micro-analyzer). We found a solubility limit of the order of 10-4 mol Mo/mol U, i.e. 0.01 %weight of Mo/UO2.Then niobium, with its redox forms Nb2O5/NbO2, has been identified as a promising candidate due to different selection criteria (physico-chemical and neutronic properties). The first step was to prepare UO2 with this buffer. A specific manufacturing process of the buffered UO2 fuel, doped with the (Nb2O5/NbO2) couple has been developed in order to preserve both oxido-reducing forms of the oxygen buffer in the pellets while sintering. This process has been also validated for UO2 doped with the (MoO2/Mo) couple. We have shown that the initially introduced (Nb2O5/NbO2) buffer was transformed during sintering into (UNb2O7/NbO2). The equilibrium of the latter couple is very close to that of the initial buffer and therefore it can fulfill its role of pO2 control in the targeted domain.Then, the final objective was the validation of the buffer effect related to the addition of (Nb2O5/NbO2) in UO2. So we first studied by means of High Resolution X-Ray diffraction at high temperature (HR HT XRD) and Neutron Diffraction (DN) the variation of the lattice parameter of the UO2 fluorite matrix in presence of the niobium pO2 buffer. The latter can act as a local buffer enforcing a stabilization of the pO2 within the system and therefore of the stoichiometry of the UO2+x matrix. We also show that the U-Nb-O system has many ternary phases including Nb4+ and Nb5+cations, all stable on a narrow domain of pO2. Thus, these different ternary phases participate to buffer systems, which make it possible to regulate the oxido-reducing disturbances imposed on the material without any notable modification of the pO2 (stabilization of the lattice parameter).Then, the UO2 pellets elaborated with the (Nb2O5/NbO2) buffer couple were implanted with cesium, iodine, molybdenum and tellurium ions in a thin surface layer (1 µm approximately). Speciation were characterized by X-Ray Absorption Spectroscopy, using synchrotron radiation (KARA)

Hemoglobin-based oxygen carriers for use as transfusion fluids have emerged as a leading technology directed at stemming shortages of a safe blood supply and providing a readily available resuscitation fluid in various trauma situations. The purpose of this investigation was to determine the effects of isovolemic hemodilution with Hespan and a hemoglobin-based oxygen carrier (HBOC) on erythrocyte-associated transients (EATs) in capillary PO2. The particulate nature of blood flow in capillaries, when observed from a stationary observation point, results in fluctuations of PO2 as alternating red blood cells and plasma gaps move through the detection region. Therefore, through experimental methods which provided the necessary temporal and spatial resolution required to make such measurements, EATs can be observed and corresponding PO2 fluctuations can be determined. The spinotrapezius muscle in sixteen Sprague-Dawley rats was exteriorized for intravital microscopy measurements in capillaries. Capillary PO2 was measured using Pd-porphyrin phosphorescence quenching microcopy. The hemodiluents used in isovolemic hemodilution included Hespan, a non-oxygen carrying plasma expander, and Oxyglobin®, a HBOC. Two isovolemic hemodilution steps were performed, reducing the systemic hematocrit to an average of 27.5% after the first step and 13.5% after the second step. Results showed that erythrocyte-associated transients in PO2 can be observed in the rat spinotrapezius with significant differences occurring between red blood cell and plasma gap PO2 under control conditions, isovolemic hemodilution with Oxyglobin after step one, and isovolemic hemodilution with Hespan after step two. This study concludes that EATs are observable and PO2 transients relating to EATs can be measured in the rat spinotrapezius muscle. Furthermore, it can be concluded that the HBOC Oxyglobin caused a decrease in erythrocyte-associated capillary PO2 transients, as well as a general decrease in capillary PO2. In addition, this study concludes that erythrocyte-associated capillary PO2 transients can best be observed under control conditions and after step two of isovolemic hemodilution with Hespan.

Nous avons etudie les proprietes de transport des bronzes quasi-bidimensionnels (po#2)#4(wo#3)#2#m (m=4 a 14). Ces composes subissent des transitions de peierls vers un etat a onde de densite de charge (odc) constituee d'une modulation de la densite electronique couplee a une distorsion periodique du reseau. Le parametre m est associe a l'epaisseur des feuillets conducteurs wo#6. Avec un nombre d'electrons de conduction constant par maille primitive, on peut etudier l'influence de la variation de la densite electronique et du caractere bidimensionnel sur les instabilites de peierls. Les mesures de magnetotransport dans les composes m=4 et m=6 ont ete interpretees a l'aide d'un modele a deux bandes indiquant que la surface de fermi (sf) dans l'etat odc est plus petite dans le compose m=6 que dans m=4. La destruction de la sf semble etre plus complete dans m=6 probablement par suite d'un caractere bidimensionnel plus accentue. Nous avons caracterise le compose m=5 par des mesures de proprietes de transport. Des oscillations quantiques de grande amplitude ont ete observees a basse temperature (t0. 3k) et sous fort champ magnetique (b27t). Leur analyse indique que la sf dans l'etat odc est quasicylindrique d'une taille superieure a celle des composes m=4 et 6. L'apparition de nouvelles frequences d'oscillation sous fort champ (b>18t) pourrait etre liee a un effet de rupture magnetique. Des etudes sur le compose m=7 ont conduit a la mise en evidence d'un etat supraconducteur a t#c=0. 3k. Le comportement galvanomagnetique de m=7 et m=8 a ete interprete dans le cadre d'un modele d'interferences quantiques, associe un desordre cristallin important dans la plupart des echantillons a grand m. Nous anvons compare les proprietes physiques a travers la serie : l'augmentation considerable des temperatures de transition de peierls et de la resistivite electrique en fonction de m a ete attribuee a un renforcement des correlations electroniques et du couplage electron-phonon.

Nous avons etudie les proprietes de transport des bronzes monophosphates de tungstene quasi bidimensionnels (po 2) 4(wo 3) 2 m, avec m=4, 5, 6. Ces composes subissent des transitions de peierls vers un etat onde de densite de charge (odc), caracterise par une modulation de la densite electronique couplee a une distorsion periodique du reseau atomique. Le parametre m dans la formule chimique est associe a l'epaisseur des feuillets conducteurs wo 6. Le compose m=5 existe sous deux structures cristallines differentes : le compose m=5 regulier, compose de couches correspondant a m=5, montre des proprietes de transport differentes de celles de la structure alternee, qui est une intercroissance reguliere de couches m=4 et m=6. Les mesures de resistivite, de magnetoresistance, de l'effet hall et du pouvoir thermoelectrique indiquent qu'une transition de peierls a lieu a t p=60 k dans la variete reguliere. La structure reguliere m=5 a des proprietes semblables aux composes voisins m=4 et m=6. Les oscillations shubnikov-de haas dans le compose m=5 a structure alternee, mesurees en fonction du champ magnetique, de son orientation et de la temperature, ont permis de determiner un grand nombre de parametres caracterisant l'etat onde de densite de charge. L'apparition de frequences d'oscillation supplementaires en champ magnetique fort a ete attribue a l'effet de la rupture magnetique. Le caractere quasi bidimensionnel de la surface de fermi donne lieu a des oscillations angulaires de la magnetoresistance (amro), observees dans plusieurs composes. Ainsi, nous avons determine la forme d'une poche sur la surface de fermi dans les composes m=6 et m=5 (alterne), respectivement. Selon le compose etudie, les temperatures de peierls peuvent diminuer ou augmenter lorsque l'on applique une pression hydrostatique. Les taux de variation dt p/dp ont ete relies aux chaines d'octaedres wo 6 dans les bronzes monophosphates de tungstene.

Nous avons etudie la magnetoresistance des bronzes oxygenes de metaux de transition, le bronze violet kmo#6o#1#7 et les composes m=4, 6, 7 de la famille (po#2)#4(wo#3)#2#m. Ces composes ont des proprietes quasi-bidimensionnelles. Ils subissent des transitions de peierls a une temperature t#p. La magnetoresistance de kmo#6o#1#7 a ete mesuree a des temperatures comprises entre 1. 8 k et 300 k en champ magnetique jusqu'a 37 t. Des oscillations quantiques ont ete observees. Base sur le concept du nesting cache, nous proposons un modele de la surface de fermi dans l'etat d'onde de densite de charge. Elle serait constituee de petites poches lesquelles seraient a l'origine de la magnetoresistance elevee au-dessous de t#p. La temperature de peierls, observee par des mesures de resistivite electrique sous pression hydrostatique, augmente avec la pression. La compressibilite des parametres du reseau est anisotrope. La resistivite et la magnetoresistivite ont ete etudiees a des temperatures comprises entre 4. 2 k et 300 k en champ magnetique jusqu'a 6 t dans les composes m=4, 6, 7 de la famille (po#2)#4(wo#3)#2#m. La temperature de peierls augmente avec m. La magnetoresistivite diminue, ainsi que l'anisotropie quand m augmente. Nous discutons ce comportement en considerant le caractere de basse dimensionnalite, la densite de porteurs et la densite de defauts cristallins

Representa la conclusión de los estudios realizados sobre el campo de la Auditoría de Sistemas. La investigación surge a raíz de la necesidad creciente de las organizaciones por contar con herramientas automatizadas que permitan administrar la información de forma oportuna y confiable. Sin embargo debido a esta necesidad, los sistemas son cada vez más complejos, integrados y relacionados. Esto hace que sea cada vez más necesario en todas las organizaciones garantizar el cumplimiento de normas y procedimientos relacionados con la gestión de las tecnologías de información. El resultado del trabajo es el diseño de un software de apoyo a la auditoría, basado en el marco de referencia Cobit, que permita a sus usuarios obtener el nivel de madurez del área de TI mediante una metodología sencilla: la validación del nivel de madurez mediante: cuestionarios, un esquema de pesos por opción seleccionada, un plan de actividad de auditoría y recomendaciones para mejorar el nivel de madurez en el área de TI. El diseño propuesto representa una herramienta ampliamente flexible que permita acoplar nuevos estándares de evaluación mediante la actualización de la base de conocimiento en cada objetivo de control de Cobit. Además es de fácil mantenimiento, flexible y sencilla. Mediante este trabajo se busca acercar a las organizaciones a los procedimientos de mejora continua, a las recomendaciones internacionales y, de esa forma, mantener un mejor control del software y las actividades relacionadas con este.
Trabajo de suficiencia profesional

Das Vorkommen von über den Umgebungsdruck erhöhten Sauerstoffpartialdrucken in Geweben ist im Tierreich nur von der Schwimmblase und dem Auge von Knochenfischen bekannt. Die physiologischen Mechanismen dieser Sauerstoffkonzentrierung wurden an der Schwimmblase insbesondere des Aals intensiv untersucht, entsprechende Untersuchungen zu den Vorgängen im Auge der Knochenfische fehlen jedoch. In dieser Arbeit wurde daher eine Methode etabliert, mit der die Sauerstoffkonzentrierung im Auge der Knochenfische an isolierten Augen untersucht werden kann. 1. Das Gefäßsystem der Regenbogenforelle (Oncorhynchus mykiss, Walbaum 1792) wurde durch Gefäßausgüsse dargestellt. Das im Auge gelegene choroidale Rete mirabile wird über die Arteria ophthalmica, die gleichzeitig die efferente Pseudobranchienarterie darstellt, versorgt. Die Pseudobranchie selber empfängt das Blut aus der efferenten Arterie des ersten Kiemenbogens. Diese Gefäßtopologie, Versorgung der Pseudobranchie mit bereits im ersten Kiemenbogen oxygeniertem Blut und auschließliche Versorgung des choroidalen Rete mirabile mit Blut aus der Pseudobranchie, weist auf die Bedeutung der Pseudobranchie für die Prozesse im Auge hin. 2. Die Retina der Regenbogenforelle wurde mikroskopisch untersucht. Die einzelnen Schichten der Retina entsprechen denen anderer Wirbeltiere. Die Forellenretina ist mit 407 µm aber wesentlich dicker als z.B. die Retina von Mammaliern. Zusätzlich fehlt der Retina der Forelle die bei vielen Mammaliern vorhandene retinale Blutgefäßversorgung. Mit den der Retina am nächsten gelegenen Gefäßen in der Choroidea bestehen bei der Forelle wesentlich größere Diffusionsstrecken von den Blutgefäßen zum Ort des Sauerstoffverbrauchs in den Zellen der Retina als bei anderen Wirbeltieren. Dies wir durch den erhöhten Sauerstoffpartialdruck in den Choriokapillaren kompensiert. 3. Für die Messung des intraretinalen Sauerstoffpartialdrucks wurden im Rahmen dieser Arbeit Sauerstoffmikroelektroden inklusive der zur Betreibung der Elektroden notwendigen Elektronik entwickelt. Die Elektroden waren vom Recess-Typ: die reaktive Oberfläche schloss nicht mit dem Ende der Glaskapillare ab, sondern war unter Belassung eines Hohlraumes in der Elektrodenspitze (Recess) in das innere der Glaskapillare verlagert. Dadurch waren die Elektroden unempfindlich gegenüber Rühreffekten. Die Mikroelektroden hatten eine Spitzendurchmesser von < 10 µm und eine mittlere Empfindlichkeit von 172 fA Torr-1 O2. Die Linearität der Elektroden über eine Partialdruckbereich von 0 bis 760 Torr O2 war besser als r = 0,9998. 4. Zur Überprüfung des normale Sauerstoffpartialdrucks in der Retina wurden Regenbogenforellen betäubt und künstlich ventiliert. Die systemischen Parameter wie arterieller PO2-Wert, Blutdruck und Herzschlag entsprachen dabei im Mittel mit 99 Torr (arterieller PO2), 28 Torr (Blutdruck) und 1,23 Hz (Herzschlag) den Werten unbetäubter, freischwimmender Forellen. Lediglich der arterielle pH-Wert war mit 8,02 während der künstlichen Ventilation durch eine ungenügende Kompensation einer respiratorischen Alkalose leicht gegenüber dem normalen Wert von 7,9 erhöht. 5. Die Auswirkungen der Präparation des Auges zur Messung des intraretinalen Sauerstoffpartialdrucks auf den Augeninnendruck wurde überprüft. Der Augeninnendruck betrug 4,9 Torr. Die Einbringung der Sauerstoffmikroelektrode hatte keine Auswirkung auf den Augeninnendruck. Erst das Entfernen der Elektrode nach der Messung führte zu einer deutlichen Verringerung des Augeninnendrucks. 6. Zum ersten Mal wurde in der vorliegenden Arbeit die Durchblutungsrate des Auges eines Knochenfisches bestimmt. Aus präparatorischen Gründen wurde die Messung an der afferenten Pseudobranchienarterie durchgeführt. Der mittlere Blutfluss in dem Gefäß betrug 745 µl min-1 kg-1. Durch Verschluss des kontralateralen Gefäßes stieg der Fluss auf 135% des ursprünglichen Wertes, da jetzt durch das ipsilaterale Gefäß und über die zwischen den beiden Gefäßen bestehende Anastomose beide Augen durch das ipsilaterale Gefäß mit Blut versorgt wurden. 7. Die Funktion der Retina während der intraretinalen Sauerstoffmessung wurde durch Ableitung des Elektroretinogramms kontrolliert. Trotz der während der Versuche fortbestehenden Betäubung mit dem Betäubungsmittel MS222, welches sich negativ auf das Elektroretinogramm auswirken soll, konnten normale Elektroretinogramme aufgezeichnet werde. Die invasive Messung des intraretinalen PO2 wirkte sich nicht negativ auf die Funktionalität der Retina aus. 8. Der intraretinale Sauerstoffpartialdruck wurde an betäubten, künstlich ventilierten Forellen überprüft. Der mittlere maximale PO2 im Bereich der Bruch´schen Membran betrug 382 Torr. An der Innenseite der Retina wurde ein PO2 von 10 Torr gemessen. Der Bereich des O2-Partialdruckgradienten in der Retina, gemessen über den Vorschub der Sauerstoffmikroelektrode vom niedrigsten bis zum höchsten PO2, betrug 433 µm, ein Wert der gut mit der mikroskopisch bestimmten Dicke der Retina (407 µm) übereinstimmt. 9. Zur Untersuchung der Einflüsse von Blutparametern auf die Sauerstoffkonzentrierung im Auge der Forelle wurden isolierte Augen künstlich mit verschiedenen Erythrozytensuspensionen perfundiert. Dazu wurde zum einen eine Suspension von Forellenerythrozyten eingesetzt, bei der erst der Root-Effekt in Abhängigkeit vom pH-Wert der Suspension bestimmt wurde. Bei basischem pH-Werten war das Hämoglobin der Erythrozyten vollständig gesättigt. Bei einem pH-Wert von 7,68 war noch eine Sättigung von 90% vorhanden, die bis zu einem pH-Wert von 7,31 auf 50% abnahm. 10% Sättigung wurden bei einem pH-Wert von 6,94 erreicht. Für die Perfusion wurde die Suspension der Forellenerythrozyten mit einem pH-Wert von 7,48 eingesetzt. Bei diesem pH-Wert liegt die Sättigung bei ca. 82% und eine Änderung des pH hat in diesem Bereich eine deutliche Änderung der Sättigung zur Folge, was die Freisetzung von O2 von Hämoglobin erleichtert. Als alternative Perfusionslösung wurde eine Suspension von Humanerythrozyten eingesetzt. Humanhämoglobin weist keinen Root-Effekt auf, es kann also durch die im Auge der Knochenfische vorhandenen Mechanismen kein Sauerstoff freigesetzt werden. 10. Der mittlere intraretinale Sauerstoffpartialdruck isolierter Augen betrug bei Perfusion mit der Suspension von Forellenerythrozyten 99 Torr. Nach dem Wechsel auf die Suspension mit Humanerythrozyten fiel der intraretinale Sauerstoffpartialdruck sofort auf 30 Torr ab. Der Perfusionsdruck änderte sich bei dieser Umstellung nicht. Bei Perfusion mit Ringerlösung fiel der intraretinale PO2 auf 20 Torr, gleichzeitig fiel jetzt auch der Perfusionsdruck ab. 11. Eine Konzentrierung des Sauerstoffs konnte bei der künstlichen Perfusion isolierter Augen nicht nachgewiesen werden. Die Notwendigkeit des Root-Effekts für einen hohen Sauerstoffpartialdruck im Auge wird trotzdem deutlich, da bei Perfusion mit einer Suspension von Humanerythrozyten, die einen höheren Sauerstoffgehalt aufwies als die Suspension der Forellenerythrozyten, der intraretinale Sauerstoffpartialdruck deutlich geringer war. 12. Das Modell des isoliert perfundierten Auges ist zur physiologischen Untersuchung des choroidalen Rete mirabile und Sauerstoffkonzentrierung besser geeignet als in vivo - Experimente, da systemische Einflüsse vermieden und die Auswirkungen der Pseudobranchie auf die Blutchemie ausgeschaltet werden können.
Oxygen partial pressures (Po2) above ambient levels are found only in the swimbladder and the eye of teleost fish species. The mechanisms related to the involved oxygen concentration processes have been investigated to some detail in eel swimbladder, but little attention has been paid to analogous mechanisms of the teleost eye. This thesis has accordingly concentrated on developing a method promoting investigation of oxygen concentrating mechanisms in teleost eyes by application of an isolated perfused eye preparation. 1. The vascular supply of eye and pseudobranch in rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) was depicted by corrosion casts of the vascular system. The choroid rete mirabile is supplied with blood by the ophthalmic artery as the efferent blood vessel of the pseudobranch, with a small anastomosis to the contralateral vessel. The pseudobranch in turn is fed by the efferent artery of the first gill arch. This pattern of serial vascular connection suggests a role for the pseudobranch in the process of providing high oxygen tensions required for the high metabolic demand of the visual perception in the retina. 2. Eyes of various fish species were sectioned after paraffin embedding and examined microscopically. The organisation of teleost fish retinae is characterised by the same features and organisation well known from other vertebrates. However, the total thickness of 407 µm found for the retina of the rainbow is much larger than that observed in other animals such as mammals. The conditions of diffusive oxygen supply of retinal nerve cells is further hampered by the complete lack of intraretinal blood vessels commonly found in mammals. In trout, blood is supplied to only the choroid layer, leaving large diffusion distances to the retinal nerve cells to be spanned by oxygen partial pressures, elevated as compared to the bulk arterial system in the choroid capillaries. 3. Intraretinal oxygen partial pressure was determined in long-term anaesthetised specimens of Oncorhynchus mykiss, using specially developed oxygen microelectrodes and required electronic circuitry. Characteristic features of the electrodes include insensitivity of the signal to stirring, achieved by a recess of the reactive metal surface in a glass capillary, an average tip diameter of less than 10 µm and a characteristic sensitivity to oxygen of 172 fA Torr-1. The response of the electrodes to oxygen was linear over a range of partial pressures from 0 to 760 Torr O2 (r= 0,9998). 4. Normal oxygen partial pressures in trout retina were measured in long-term anaesthetised and artificially ventilated specimens of Oncorhynchus mykiss. In order to conduct the experiments under conditions as close as possible to normal homoiostasis, several systemic valuables were monitored continuously. During experimentation arterial Po2 averaged 99 Torr, mean blood pressure was 28 Torr and heart frequency was on the average 74 bpm, respectively, data in the range of values determined in unanesthetized, freely swimming trout. As the one exception, arterial pH (8,02) was slightly elevated during artificial ventilation as compared to control values (7,89), a shift induced by an inadequately high rate of artificial ventilation. 5. The impact of insertion of electrodes required for intraretinal Po2 measurement into the eye was found to have little effect. The intraocular pressure remained unaffected by opening the eye by puncture with leading cannula and inserted micro-Po2-electrode. The intraocular pressure fell only after removing the electrode after completion of the experiment. 6. Normal function of the retina during experimentation in vivo was checked by repeatedly measuring electroretinograms provoked by light flashes under dark ambient conditions. Although extended anaesthesia with MS222 is expected to affect the electroretinogram in fish, there was no indication of abnormal or reduced electroretinograms during experimentation. Also puncture of the eye with insertion of electrodes did not affect the electroretinogram. 7. Intraretinal Po2 was measured in anaesthetised and artificially ventilated trout. Oxygen profiles were recorded during advancement of the electrode tip though the retina, from the lowest Po2 at the inner surface with about 10 Torr to the highest Po2 in the region of Bruch´s membrane with about 382 Torr, travelling a total distance of 433 µm. This distance closely corresponds to the thickness of the retina measured by microscopic sectioning. 8. Blood flow to the eye as an important parameter for the establishment of an isolated eye preparation was measured in the afferent artery of the pseudobranch. Due to the anatomical situation this represents the closest possible approximation to measurement of flow in the ophthalmic artery. The blood flow was estimated by ultrasonic Doppler techniques with in situ calibration to be 216 µl min-1. Occlusion of the contralateral vessel resulted in an increase of the blood flow in the ipsilateral vessel to 135% of the original as a result of flow through the small anastomosis between the two ophthalmic arteries. This estimate is the first performed for blood flow to the eye of a fish. 9. An isolated eye preparation was used to investigate the influence of specific blood parameters on oxygen concentrating processes in the eye of Oncorhynchus mykiss. Eyes were perfused with suspensions of trout erythrocytes, human erythrocytes and Ringer´s solution. The Root Effect of trout haemoglobin was confirmed in suspension of erythrocytes. The haemoglobin was fully saturated at pH 8.45, still 90% saturated at 7.68, 50% at 7.31 and 10% at pH 6.94. In order to provide optimal starting conditions for the release of oxygen by relatively small changes in pH, pH 7.48 (resulting in 82 % saturation) was chosen for the perfusion of isolated eyes. As a control perfusion, suspensions of human erythrocytes provided a perfusate lacking any Root effect, thus not supporting the oxygen concentrating processes in fish eyes. 10. Perfusion of isolated trout eyes with pH 7.48 trout erythrocyte suspension resulted in an average intraretinal Po2 of 99 Torr, whereas perfusion with human erythrocytes resulted in an immediate decrease of Po2 to (of) 30 Torr, with a further drop to 20 Torr during perfusion with Ringer´s solution. Changes in perfusion between erythrocyte suspensions were performed without any changes in perfusion pressure, but the switch to control perfusion with Ringer´s solution exhibited a drop in perfusion pressure due to the reduced viscosity of the medium. 11. Although perfusion of isolated eyes did not exhibit Po2 above ambient values, the effect of oxygen concentrating processes were clearly indicated by comparison with Root effect-lacking human erythrocyte perfusate (Po2´s of 99 vs. 30 Torr, respectively). 12. It is concluded that studies of oxygen concentrating mechanisms are to be performed preferably on isolated eye preparations. For closer analysis of the involved mechanisms this preparation allows for isolated control of individual parameter of the perfusate. In particular, uncontrolled effects of the pseudobranch on the perfusate can be eliminated.

Dissertação de Mestrado Integrado em Medicina Veterinária
Os tumores da mama representam a neoplasia mais frequente na cadela, com uma taxa de malignidade de cerca de 50%. A elevada taxa de proliferação celular verificada no desenvolvimento tumoral, resulta num inadequado aporte de oxigénio a algumas regiões do tumor originando zonas de hipoxia, a qual se relaciona num sistema causa-efeito com o nível de resposta terapêutica dos doentes oncológicos. O estudo presente foi realizado numa amostra de 32 indivíduos (N=32), da espécie Canis familiaris, do género feminino, e teve como objectivo quantificar o valor da pressão parcial de Oxigénio (PO2) e de saturação do Oxigénio (SO2) no débito sanguíneo do tumor mamário de cadelas. A amostra foi dividida em 2 grupos: 1) um grupo controlo (GC), formado por indivíduos saudáveis sujeitos a ovariohisterectomia eletiva, e 2) um grupo estudo (GM), formado por cadelas com tumor mamário e submetidas a mastectomia. Cada individuo foi sujeito a duas colheitas de sangue, por punção nas veias epigástrica superficial caudal da mama e veia safena. A quantificação da PO2 e SO2 foi realizada utilizando o aparelho i-Stat, com o sistema analítico CG4+. A média de PO2 na veia epigástrica caudal foi de 130,1±51,7 mmHg no GC e 166,5±49,9 mmHg no GM, e de 125,2±45,4 no GC e 122,9±60,1 no GM para a PO2 na veia safena. Para a SO2 a média foi de 97,6±3,3% no GC e 94,7±7,6% no GM, na veia safena, e de 97,92±3,5% para o GC e de 92,9±8,4% no GM na veia epigástrica caudal. Consideraram-se os resultados estatisticamente significativos para valores de p <0,05. Não se registaram diferenças estatisticamente significativas entre PO2 de GC e GM (p >0,05) assim como entre a SO2 de ambos os grupos (p >0,05). A dimensão da amostra, e a impossibilidade de medição da PO2 e da SO2 por método de medição intra-tumoral, poderão ter sido os principais factores que influenciaram os resultados obtidos.
ABSTRACT - QUANTIFICATION OF THE PARTIAL OXYGEN PRESSURE (PO2) AND OXYGEN SATURATION (SO2) VALUES FOR THE CHARACTERIZATION OF HYPOXIA IN THE BLOOD FLOW OF MAMMARY TUMOR OF BITCHES - PRELIMINARY STUDY - Mammary tumors represent the most common neoplasia in the bitch, with a malignancy rate of about 50%. The high rate of cell proliferation observed in tumor development results in an inadequate supply of oxygen to some regions of the tumor leading to areas of hypoxia, which is related to a cause-effect system with the level of therapeutic response of cancer patients. The present study was carried out on a sample of 32 individuals (N = 32), of the Canis familiaris species of the female genus, and had as objective to quantify the oxygen partial pressure (PO2) and oxygen saturation (SO2) in the blood flow of mammary tumor of bitches. The sample was divided into 2 groups: 1) a control group (CG), formed by healthy individuals subject to elective ovariohysterectomy, and 2) a study group (GM), formed by patients with mammary tumor and submitted to mastectomy. Each individual was subjected to two blood collections by puncture in the caudal superficial epigastric veins and saphenous vein. The quantification of PO2 and SO2 was performed using the i-Stat apparatus with the CG4 + analytical system. The mean PO2 in the caudal epigastric vein was 130.1 ± 51.7 mmHg in the CG and 166.5 ± 49.9 mmHg in the GM, and 125.2 ± 45.4 in the GC and 122.9 ± 60, 1 in GM for PO2 in the saphenous vein. For SO2 the mean was 97.6 ± 3.3% for GC and 94.7 ± 7.6% for GM, saphenous vein, and 97.92 ± 3.5% for GC and 92, 9 ± 8.4% in GM in the caudal epigastric vein. The results were statistically significant for p values <0.05. There were no statistically significant differences between PO2 of GC and GM (p> 0.05) as well as between SO2 of both groups (p> 0.05). The size of the sample and the impossibility of measuring PO2 and SO2 by intra-tumor measurement method may have been the main factors that influenced the results obtained.
N/A

Comprendre les mécanismes de spéciation des Produits de Fission (PF) dans le combustible nucléaire est un enjeu majeur pour pouvoir estimer précisément le terme source d’un accident grave. Parmi les nombreux PF créés, certains sont très réactifs et peuvent avoir un impact radiologique important en cas de relâchement dans l’atmosphère. C’est notamment le cas du césium (Cs), du molybdène (Mo) et du baryum (Ba). C’est dans ce contexte que s’inscrit le travail de thèse qui propose d’apporter des données expérimentales sur l’effet du potentiel oxygène sur la spéciation du Cs, du Mo et du Ba dans des combustibles nucléaires, à différents stades d’un accident grave.Une approche thermodynamique a été utilisée en support à l’interprétation des données expérimentales obtenues dans le cadre de ce travail. Deux types d’échantillons ont été étudiés: des combustibles MOX irradiés et des matériaux simulant un combustible UO2 à fort taux de combustion, obtenus par frittage à haute température (SIMFuel). Les échantillons ont été traités thermiquement dans des conditions représentatives d’un accident grave survenant dans un Réacteur à Eau Pressurisée (REP). Les conditions expérimentales ont couvert une gamme de température allant de 400°C à 2530°C et des potentiels oxygène situés entre -470 kJ.mol(O2)-1 et -100 kJ.mol(O2)-1. Les échantillons ont été caractérisés finement avant et après chaque traitement à l’aide de techniques complémentaires comme la microscopie optique et électronique, la microsonde et le SIMS dans le cas de l’irradié. Des mesures de XANES sur synchrotron ont été réalisées sur SIMFuel et ont conduit à des résultats importants en termes de spéciation des PF. Enfin, la technique de Spark Plasma Sintering (SPS) a été explorée avec succès pour la fabrication de SIMFuel contenant du Cs, du Mo et du Ba sous des formes chimiques représentatives d’un combustible REP en fonctionnement nominal.Ce travail a permis de mettre en évidence l’effet de la température en conditions oxydantes sur le comportement du combustible et des PF. Une oxydation du Mo, initialement présent sous forme métallique dans les inclusions blanches du combustible, en MoO2 a été observée dès 1000°C en conditions oxydantes. Une interaction entre le MoO2 formé et le Ba contenu dans la phase oxyde a eu lieu dans les mêmes conditions, menant à la formation de BaMoO4. Le potentiel oxygène joue aussi un rôle important dans le phénomène d’interaction pastille-gaine, en favorisant la diffusion des espèces en conditions oxydantes, diminuant ainsi la température de fusion du combustible
In the nuclear community, it is a top priority to gain in-depth understanding of fission product (FP) speciation mechanisms occurring in nuclear fuel in order to precisely estimate the source term of a severe accident. Among the FP produced, some are highly reactive and may have a strong radiological impact if released into the environment. This is particularly the case of cesium (Cs), molybdenum (Mo) and barium (Ba). In this context, the objective of this study is to provide experimental data on the effect of the oxygen potential on Cs, Mo and Ba speciation in nuclear fuels at different stages of a severe accident.A thermodynamic approach was coupled with the experimental work to support the interpretation of experimental data. Two types of samples were studied in detail: irradiated MOX fuels and simulated high burn-up UO2 fuels produced through sintering at high temperature (SIMFuel). The samples were submitted to thermal treatments in conditions representative of a pressurised water reactor (PWR) severe accident. This approach made it possible to cover a temperature range from 400°C up to 2530°C and oxygen potentials from -470 kJ.mol(O2)-1 to -100 kJ.mol(O2)-1. The samples were characterized before and after each test using complementary techniques like OM, SEM, EPMA and SIMS in the case of irradiated fuels. XANES measurements using synchrotron radiation facilities were performed on SIMFuels and provided valuable results on FP speciation. Moreover, spark plasma sintering (SPS) was successfully investigated for the production of SIMFuel samples containing Cs, Mo and Ba in a chemical state representative of PWR fuel in normal operating conditions.This work highlighted the effect of oxidizing severe accident conditions on the fuel and FP behavior. Oxidation of Mo initially contained in the fuel’s metallic inclusions into MoO2 was observed to take place around 1000°C in oxidizing conditions. An interaction between MoO2 and the oxide phase containing Ba took place in the same conditions, leading to the formation of BaMoO4. The oxygen potential also plays an important role in fuel-cladding interactions, enhancing the diffusion of species in oxidizing conditions and lowering the temperature at which fuel melting occurs

Cette these est repartie en six chapitres. Le premier chapitre contient une introduction aux proprietes electroniques des oxydes de metaux de transition. Le deuxieme chapitre presente les idees theoriques permettant la description des transitions de phases structurales du type onde de densite de charge et (anti)ferroelectriques. Le troisieme chapitre decrit les techniques de diffraction de rayons x qui ont ete utilisees ou mises au point pendant le travail de these. Le quatrieme chapitre fait le point sur les oxydes de tungstene en general et plus en particulier sur les bronzes etudies dans cette these. Le cinquieme chapitre presente le diagramme de phase structural, mesure par diffraction et diffusion des rayons x, des membres de la famille des bronzes monophosphates de tungstene avec tunnels pentagonaux (po2)4(wo3)2m de valeur de m compris entre huit et quatorze: on observe une large variete de transitions de phase structurales vers des phases modulees ; ces phases montrent des vecteurs d'onde de modulation parfois commensurables, parfois incommensurables, avec plusieurs harmoniques du vecteur d'onde de modulation, interactions entre modulations differentes et hautes temperatures critiques. Le sixieme chapitre contient l'analyse des donnees obtenues: la competition entre instabilites du type onde de densite de charge du gaz d'electrons et instabilites du type antiferroelectrique du squelette de trioxyde de tungstene sous-jacent est a l'origine du diagramme de phase structural observe ; une comparaison entre la physique de ces composes et celle d'autres oxydes de metaux de transition est aussi presentee

Orientador: Bruno Coraucci Filho
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: O objetivo deste projeto foi estudar os filtros de areia como um método de baixo custo para o pós-tratamento de filtros anaeróbios alimentados com esgoto sanitário. Nesta pesquisa buscou-se contribuir com o desenvolvimento deste sistema avaliando-se a eficiência de tratamento de quatro filtros de areia com diferentes profundidades de leitos (0,25; 0,50, 0,75 e 1,00 m). A alimentação era proveniente de reatores anaeróbios e foram empregadas cinco cargas diferentes de aplicação (20, 40, 60, 80 e 100 Lm-2). Cada uma delas dispostas diariamente pelo período de um mês. O esgoto bruto, afluente e efluente dos filtros de areia foram analisados semanalmente, permitindo constatar que no emprego de baixas cargas de efluente anaeróbio o sistema propiciava uma remoção superior a 96% da DBO, adequação na emissão de coliformes totais e completa nitrificação. Aumentando-se as cargas, ocorria uma pequena redução da eficiência, no entanto os resultados ainda eram satisfatórios
Abstract: The aim of this project was to study sand filters as a low cost method in the post treatment of upflow anaerobic filter effluent, fed by municipal wastewater. This research intends to contribute with the development of this system estimating the efficiency of the treatment of four sand filters with different depths of the sand layer (0,25; 0,50, 0,75 e 1,00 m). The feed (I think it's influent) was from the four upflow anaerobic filters. Five hydraulic loads (20, 40, 60, 80 e 100 Lm-2) were used to apply the effluent on the sand filters. Each one was applied for one month and later the frequency was increased for two and tree times per day. The municipal wastewater, influent and the effluent of the sand filter were weekly analyzed allowing to conclude that the treatment system had good removal of BOD, COD, TOC, nutrients and microorganisms like total and fecal coli forms. The effluent was good to be disposed or to reused.
Mestrado
Saneamento e Ambiente
Mestre em Engenharia Civil

A startup’s ability to make correct decisions regarding their Cloud choices is essential if they intend to stay competitively relevant in their business. Choosing the Cloud solutions that allow for an optimal level of production can give startups that operate in most industries a competitive advantage. However, new startups have a plethora of factors to consider when choosing a Cloud provider, which is the basis of the thesis. The purpose of the study is to explore and gain insight regarding how new startups can make suitable decisions when selecting different Cloud services. The study’s main data collection method is a set of interviews that were conducted with CTOs from some of Sweden’s most promising startup companies. The study thoroughly discusses the three largest Cloud providers (Amazon Web Services, Azure, and Google Cloud Platform), and attempts to reveal how these Cloud services are positioned in the eyes of the customers that use them on a daily basis. A main finding of the study was that the most important factors to consider when selecting a Cloud provider is its compatibility with your company’s IT-environment, the quality and quantity of its services, how well managed it is, if it offers data protection compliances, and ultimately, the prices of the services it offers. Furthermore, information derived from the interviews imply that new startups ought to make their IT-solution as simple as possible in order to reduce the chances of running into integration problems with different Cloud solutions. The author intends for the study to be a guideline for new startups to better understand what factors they ought to prioritize when selecting Cloud providers.
En startups förmåga att ta de rätta besluten när det kommer till deras val av molntjänster är otroligt viktigt. Genom att välja de rätta molnlösningar så kan man se till att företaget får en bra möjlighet att växa, och att rätt molnlösningar kan det kan ge de flesta startups digitala verktyg som kan ge konkurransfördel. Det finns däremot mycket att tänka på när man väljer en molntjänst, och det är vad studien bygger på. Syftet med detta projekt var att utforska och bättre förstå hur nya startups kan ta de rätta besluten när det kommer till deras val av molntjänster. Studiens huvudsakliga datainsamlingsmetod var tolv intervjuer som utfördes tillsammans med CTOs från några av Sveriges mest framgångsrika startupföretag. Studien utför en noggrann diskussion och jämförelse på de tre största molntjänsterna i världen (Amazon Web Services, Azure, och Google Cloud Platform), och försöker att visa hur dessa molntjänster är positionerade enligt de kunder som använder sig av molntjänsterna vardaligen. Studien visar att de viktigaste faktorerna som man bör tänka på när man väljer molntjänst är: hur pass kompatibel den är med företagets IT-miljö, kvaliteten och mängden tjänster som leverantören erbjuder, hur pass managerade leverantörens tjänster är, om leverantören överensstämmer med regler för uppgiftsskydd, och kostnaden för molnleverantörens tjänster. Ytterligare så fann man indikationer från intervjuerna att nya startups bör försöka sikta på molnlösningar som är så simpla som möjligt och helst att dessa lösningar är integrerade lösningar som molnleverantören själv erbjuder, och detta på grund av att det kan vara svårt att integrera molnlösningar från olika företag. Författarens avsikt för denna rapport är att den ska vara en riktlinje för nya startups så att de kan förstå vad de bör tänka på när de väljer sina molntjänster.

La2Mo2-yWyO9 (y = 1.0 to 2.0) oxides were synthesized by conventional solid state route and studied by XRD, TC-XRD and DTA. A phase diagram of the series was proposed. The thermodynamically stable phases at room temperature are: for 1.0≤ y ≤1.2 a cubic β-La2Mo2O9 type solid solution, for 1.3≤ y ≤1.575 a biphasic mixture of β-La2Mo2O9 type + α-La2W2O9 type phases, and for 1.6≤ y ≤2.0 a triclinic α-La2W2O9 type solid solution. Inhomogeneous distribution of W is suspected in the biphasic samples. It is clear that the compounds above y =1.2 are not suitable for SOFC applications.Cationic diffusion studies were performed using SIMS on La2Mo2O9 (LMO)/La0.8Sr0.2MnO3-δ (LSM) annealed couples. Rod shaped LaMnO3 grains were observed on LMO pellet and SrMoO4 type phases were seen to be growing on LSM pellet. Hypotheses for possible reaction mechanisms are presented. Bulk diffusion coefficients of Sr and Mn in LMO and of Mo in LSM are extrapolated to be around 1x10-20 cm2.s-1 and 1x10-15 cm2.s-1, respectively, at 800oC. Similar diffusion studies were performed by depositing Mn and Sr cation rich solutions on LMO pellets and Mo rich solution on LSM pellet. Mn solution was observed to be forming, upon annealing, LaMnO3 single crystals on the surface of the LMO pellet. Mo in LSM and Sr in LMO diffusion coefficients appear to be much higher than in LMO/LSM couple experiments, namely around 1-2x10-10cm2.s-1 at 1150°C. Because of the reactivity, LMO/LSM couple is not desirable for SOFC applications, unless an appropriate buffer layer separates them.The stability of LMO and W-LMO was studied under reductive atmospheres. Successive structural changes from LMO to La7Mo7O30 (7730), an amorphous reduced phase La2Mo2O7-δ, and partial decomposition to metallic Mo were observed as a function of oxygen loss. The pO2 stability domain of La2Mo2-yWyO9 did not appear to change with W content, but the reduction kinetics varied with y. At reverse, the stability limit of the 7730 phase was found to be dependent on W content. The amorphous reduced phase can accommodate a wide range of oxygen stoichiometry (7-δ from 6.69 to 6.20), but its stability vs. pO2 is questioned. Resistivity measurements performed on a low compacity crack-free amorphous La2Mo2O7-δ sample showed significant increase in the conductivity (> 1 S.cm-1 at 1000 K) relative to La2Mo2O9, with a pseudo activation energy 0.255eV. It is postulated that n-type electronic conductivity arises from partial reduction of hexavalent Mo6+ to a mixture of Mo3+ and Mo4+.

My thesis tells of the Cambodian refugee experience. It is based on the life stories of ten Cambodian refugees who presently live in Melbourne Australia. The stories that people told me were about their experiences of life before the Pol Pot regime, their survival of one of the twentieth century's totalitarian regimes, then their travel to and life in the Thai refugee camps and more recently their experiences of resettlement and life in Australia. My work explores the profound impact these life experiences had on Cambodian people and how they remembered and told stories about their past. Further, it considers how these experiences shaped the identities of survivors of the Pol Pot years. It is clear that the Cambodian refugee experience tells us that people can do the most terrible things to other people, but it is also clear that human beings can also survive almost any situation. In this regard my work shows that life is a most precious and fragile thing, but it also has an amazing strength and resilience.

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O trabalho versa sobre a suspens?o dos direitos pol?ticos decorrente de condena??es criminais e por improbidade administrativa, expressamente prevista no artigo 15, incisos III e V, da Constitui??o Federal de 1988, e pretende verificar quais s?o os direitos efetivamente afetados nestes casos e se ? poss?vel modular o grau de afeta??o. Para tanto, os direitos pol?ticos s?o pesquisados em fontes doutrin?rias, nacionais e estrangeiras, e jurisprudenciais. Neste percurso, a pesquisa tangencia as bases te?ricas da democracia e da cidadania. Ent?o, ? esbo?ado um delineamento do que s?o os direitos pol?ticos. Ap?s, a an?lise recai sobre a viabilidade de conviverem duas no??es de direitos pol?ticos, uma estrita, outra ampla, esta manifestada, inclusive, em espa?os da vida privada. A conclus?o ? que, enquanto direito fundamental, os direitos pol?ticos devem ser amplamente considerados, ao passo que, do ponto de vista da sua restri??o, deve prevalecer a no??o estrita. Isso, por?m, n?o afasta, presentes fundamentos ?ticos e racionais, a modula??o da suspens?o dos direitos pol?ticos, aqu?m ou al?m da sua no??o estrita. Eis a principal conclus?o, considerada a melhor leitura constitucional.

Orientador: Bruno Coraucci Filho
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil e Arquitetura
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Mestrado

Orientador: David Dequech Filho
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Economia
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Resumo: A interpretação sugerida no presente estudo evidencia o caráter mais amplo assumido pela teoria da preferência pela liquidez, qual seja, de uma teoria da escolha e precificação de ativos em geral. Para tal, parte-se da explanação acerca dos motivos para demandar moeda, explicitando-se também as conexões entre esses motivos e a incerteza que permeia o ambiente econômico. Na busca pela especificidade da teoria da preferência pela liquidez, isto é, no que esta se diferencia de uma teoria alternativa para a demanda por moeda, discute-se a determinação da taxa de juros em decorrência destes motivos, com destaque para a expressão da moeda como um ativo e para o fato de rendimentos pecuniários serem auferidos por quem se dispõe a abdicar da posse de moeda e reter títulos, tudo isso com a gama de ativos limitada aos dois supracitados. Finalmente, abandonando-se o mundo dicotômico construído a partir da moeda e de um outro ativo e a partir da extensão de um mesmo princípio definidor básico, chega-se à escolha e precificação de ativos em geral, com o que a teoria da preferência pela liquidez adquire sua representação máxima.
Abstract: The interpretation suggested in the present study emphasizes the broad character of liquidity preference theory, namely, as a theory of asset choice and pricing in general. To this end, the thesis starts with the explanation of the motives to demand money, as well as the connections between these motives and the uncertainty that permeates the economic environment. Looking for the peculiarity of liquidity preference theory, as distinct from an alternative theory of demand for money, the thesis discusses the determination of the interest rate as a result of these motives, highlighting the expression of money as an asset and the fact that monetary yields are earned by whoever is willing to part with money and hold securities, all this with the basket of assets restricted to these two. Lastly, the thesis abandons this dichotomic world of money and only one other asset, and, on the basis of the same defining fundamental principle, arrives at asset choice and pricing in general, with the result that liquidity preference theory assumes its most general form.
Mestrado
Mestre em Ciências Econômicas

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Courts of Accounts have been overseeing public policies through perform audits examining the performance of programs, and also, in parallel and additionally, through traditional compliance audits of isolated administrative acts and budgetary aspects. Its importance notwithstanding, it is possible to observe that such control measures have reduced effectiveness for, in good measure, two reasons: a) still relatively distant and less synergistic relationships between control agencies, overseen administration and society; b) impossibility of, without support of proper tools, analyzing the vast universe of relevant data thay is now being registered due to technological advances. For these reasons, this research analyses the outline and characteristics of possible applications of Govtechs, technological solutions based in post-gerencialism models of public management and in the state of art of informational systems, for the control public policies by Courts of Accounts. Likewise, possible perspectives of integration between interested parties in public policies control are also examined. The conclusion is that, if the matter of full public sharing of data bases is overcome, GovTechs are powerful solutions to integrate action between agents and to data analysis, including by artificial intelligence, with the potential of increase the effectiveness of control measures, especially in the context of a society with increasing complex and sophisticated technologies.
Os Tribunais de Contas v?m realizando controle de pol?ticas p?blicas mediante auditorias operacionais focadas em avaliar o desempenho de programas, e tamb?m, paralelamente e complementarmente, pelas tradicionais auditorias de conformidade de atos administrativos isolados e de aspectos or?ament?rios. Apesar de sua import?ncia, ? poss?vel observar que tais a??es de controle ainda apresentam uma efetividade reduzida por, em grande parte, duas quest?es: a) rela??es relativamente distantes e pouco sin?rgicas entre ?rg?os de controle, entes fiscalizados e sociedade; b) impossibilidade de, sem ferramentas adequadas, analisar o vasto universo de dados relevantes que passaram a ser registrados com o avan?o tecnol?gico. Diante disso, esta pesquisa examina os contornos e caracter?sticas de poss?veis aplica??es das GovTechs, solu??es tecnol?gicas baseadas em modelos colaborativos e dial?gicos de Administra??o P?blica e no estado da arte dos sistemas informacionais, para o controle de pol?ticas p?blicas por Tribunais de Contas. Igualmente, s?o examinadas perspectivas de integra??o entre os atores interessados no controle de pol?ticas p?blicas. A conclus?o ? de que, superado o entrave do compartilhamento pleno de bancos de dados, as GovTechs s?o poderosas solu??es para a atua??o integrada entre agentes e para a an?lise dos dados, inclusive por intelig?ncia artificial, com potencial de aumentar a efetividade das a??es de controle, especialmente no contexto de uma sociedade cada vez tecnologicamente complexa e sofisticada.

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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)
O texto estabelece um debate entre a obra de Clarice Lispector e as teorias do pensamento filos?fico de Gilles Deleuze e Felix Guattari, observando, a partir do encontro dos autores, o agenciamento de uma ?escritura do deslize? no tocante ?s diversas interpenetra??es discursivas da cr?nica clariciana. Desse modo, o conceito de ?rosto? dos fil?sofos franceses enquanto ?m?quina, abstrata? subsidiar? nossa discuss?o diante da expectativa das ?combina??es deform?veis das engrenagens? do g?nero. Observa-se, ainda, nesse ?mbito, a configura??o de uma cartografia liter?ria na qual se rascunha uma ?poi?sis cotidiana? nos movimentos de desterritorializa??o e ressignifica??o das m?ltiplas imagens estabelecidas pela autora.
The text establishes a debate between the work of Clarice Lispector and theories of philosophical thought of Gilles Deleuze and F?lix Guattari , watching from the meeting of the authors, the agency of a ?deed Glide? regarding the various discursive interrelationships of chronic clariciana. Thus, the concept of ?face? of the French philosophers as ?abstract machine? subsidize our discussion at the prospect of ?deformable combinations of gears? of the genre. It is observed also in this context the setting of a literary cartography which sketches out an everyday poiesis in the movements of deterritorialisation and re-signification of multiple images established by the author.

Orientador: Rodnei Bertazzoli
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: Este trabalho investiga o desempenho do chumbo anodizado e de uma mistura de óxidos de chumbo / estanho para uso em processos de eletro-oxidação. Os eletrodos foram preparados por anodização do chumbo e ligas de chumbo/estanho previamente laminados na forma de placas para obter os filmes de óxido. A camada ativa era constituída por uma película de PbO2 e PbO2/SnOx formado durante a aplicação de uma densidade de corrente de 15 mA.cm-2, o qual a polarização foi invertida a cada 1 hora , durante o processamento , a 65 ° C em 10 % ( v / v ) H2SO4 solução. A morfologia dos revestimentos foi caracterizada por microscopia eletrônica de varredura (MEV) e difração de raios-X, que foi usada para identificar as fases presentes nas camadas de anodizadas. Voltametria cíclica foi realizada para obter o intervalo de potencial entre o hidrogênio e as reações de desprendimento de oxigênio. Área ativa dos eletrodos também foi determinada usando a equação Cottrell aplicada à reação de oxidação do ferro em uma solução de ferrocianeto de potássio. Os filmes formados foram utilizados para a eletro-oxidação do glicerol em que a concentração de carbono orgânico total foi seguida. Na sequência, esponjas de chumbo foram preparadas por prensagem do chumbo derretido em meio a partículas de cloreto de sódio. Três porosidades de esponjas foram obtidas por meio de três tamanhos de partículas de NaCl . Depois, o cloreto de sódio foi removido em água por 24 h. As esponjas foram então anodizadas em ácido sulfúrico e montadas em um reator eletroquímico de fluxo de compartimentado único com placas paralelas. O reator foi usado para experimentos de eletro-oxidação em correntes constantes para a degradação dos compostos orgânicos corante laranja 2- naftol e diazepam em soluções. As variáveis estudadas foram porosidade ânodo, vazão e densidade de corrente. O decaimento da concentração dos compostos orgânicos e de carbono orgânico total foram seguidos e análises da cinética foram realizadas . Foram calculadas as constantes de velocidade de ordem zero e de pseudo-primeira ordem. O reator através de dados obtidos de transferência de massa, pode ser correlacionando com parâmetros adimensionais como Re, Sh e números Sc . A técnica utilizada para a obtenção de eletrodos porosos PbO2 provou ser eficiente. A maioria das experiências mostrou 85 % de conversão de compostos orgânicos para o CO2 após 1 h de tratamento, a baixos valores de densidades de corrente
Abstract: This work investigates the performance of anodized lead and lead/tin alloy for using in electro-oxidation processes. The electrodes were prepared by anodizing lead and lead/tin alloy rolled plates to obtain the oxide films. The active layer was constituted by a film of PbO2 and PbO2/SnOx formed during the application of a current density of 15 mA.cm-2 which polarity was inverted every 1 h during the processing at 65 oC in a 10% (v/v) H2SO4 solution. The coatings morphology was characterized by scanning electron microscopy (SEM) and the X-ray diffraction was used to identify the phases present in the layers. Cyclic voltammetry was used to obtain the potential interval between the hydrogen and oxygen evolution reactions. Active area of the electrodes was also determined using Cottrell equation applied to the oxidation reaction of iron in a potassium ferrocyanide solution. The films were used for the electro-oxidation of glycerol during which the total organic carbon concentration was followed. In the sequence, lead sponges were prepared by pressing molten lead with sodium chloride particles. Three different sponges' porosities were obtained by using three NaCl particules sizes. After, sodium chloride was removed in water by 24 h. The sponges were then anodized in sulfuric acid and mounted in a single compartmented flow electrochemical reactor with parallel plates. The reactor was used for electro-oxidation experiments at constant currents for the degradation of an orange dye 2-naphtol solution and a diazepam solution. Variables were anode porosity, flow rate and current density. The concentration decay of the organic compounds and of total organic carbon was followed and kinetic analysis was performed. Zero and first order rate constants were calculated. Mass transfer figures of merit of the reactor were obtained by correlating dimensionless parameters such as Re, Sh and Sc numbers. The technique used for obtaining porous PbO2 electrodes proved to be efficient. Most of the experiments showed 85% of conversion of organic compounds to CO2 after 1 h of processing, at low values of current densities
Doutorado
Materiais e Processos de Fabricação
Doutor em Engenharia Mecânica

O estudo avaliou a efetividade de um sistema para tratamento de soluções aquosas contendo poluentes orgânicos emergentes (POE), denominados interferentes endócrinos (IE). Baseado nos processos oxidativos avançados (POA), empregando ozônio, radiação UV, peróxido de hidrogênio e variação de pH, o estudo possibilitou determinar a relação ideal oxidante/poluentes e o custo/benefício dos tratamentos com melhores desempenhos, de degradação do padrão contendo hormônios 17?-estradiol (E2) e 17?-etinilestradiol (EE2), e outra contendo atrazina (ATZ). Para os estudos, foi utilizado um planejamento fatorial 23, para identificar as melhores opções de degradação. Os tratamentos iniciaram com soluções em concentrações de 600 ?g L-1 de ATZ, em quadruplicatas, por períodos de até 10 minutos. Posteriormente a avaliação dos melhores tratamentos, foi estudada a cinética de mineralização de soluções a 5 mg L-1 de ATZ, em até 90 min. A concentração de estudo adotada para os hormônios foi de 1 mg L-1. A determinação da ATZ e dos hormônios (E2 e EE2) foi realizada por cromatografia em fase líquida (CLAE), utilizando a extração em fase sólida (EFS) quando necessário. Para o estudo foram construídos dois sistemas de tratamento paralelamente acoplados (S1 - escala laboratorial e S2 - escala piloto), com os respectivos volumes de 0,43 L e 20 L. O S2 possibilitou a avaliação da degradação e/ ou mineralização do fenol em solução a 50 mg L-1, porém em escala 60 vezes superior ao S1. As eficiências das mineralizações da ATZ e do fenol, foram avaliadas pela análise de Carbono Orgânico Total (COT). As condições experimentais pré-estabelecidas foram: (i) UV-C 254 nm, variando entre 0, 16 e 32 W; (ii) H2O2 entre 0, 50 e 100% do total teórico necessário para mineralização dos poluentes; (iii) O3 (4,6 g h-1) e (iv) pH 7; 9 e 11, previamente aplicadas às soluções estoque de ATZ. Após avaliação da melhor combinação para degradação, optou-se por trabalhar, nos demais estudos, apenas com soluções em pH 11,0. Na última etapa deste estudo, foram desenvolvidos dois métodos (direto e indireto) para avaliar a geração do gás ozônio em tempo real, possibilitando também realizar a medição do consumo de O3 durante os estudos. Para avaliar a eficiência dos métodos, os resultados analíticos foram convertidos em % de degradação ou mineralização e os custos dos tratamentos foram estimados. Comprovando a viabilidade desta proposta, resultados envolvendo o tratamento de solução padrão de atrazina (600 ?g L-1) apresentaram, nas melhores condições (pH 11, 30 mg L-1 de H2O2 e 4,6 g L-1 de O3), eficiência igual ou superior a 95% (The study evaluated the effectiveness of a system for treatment of aqueous solutions containing emerging organic pollutants (EOP), called endocrine disruptors (ED). Based on advanced oxidation processes (AOP) using ozone, UV radiation, hydrogen peroxide and pH variation. This study allowed the determination of the ideal oxidant/pollutants ratio and the cost/benefit of treatments with better performance, regarding the degradation of the pattern containing hormones 17?-estradiol (E2) and 17?-ethinylestradiol (EE2), and another containing atrazine (ATZ). A 23 factorial design was used in the study to identify the best options for degradation. The treatments were started with solutions at concentrations of 600 ?g L-1 ATZ, in quadruplicate, for periods up to 10 min. Subsequently to the best treatment evaluation; the degradation of 5 mg L-1 ATZ solutions was evaluated, within 90 min. The adopted study concentration of the hormones was 0,05 mg L- 1 and 1,0 mg L- 1. The determination of the ATZ and hormones (E2 and EE2) was performed by liquid chromatography (HPLC) using solid phase extraction (SPE) when necessary. For this study, two parallel coupled processing systems were constructed (S1 - Laboratory scale and S2 - pilot scale) with the respective volumes of 0.43 L and 20 L. S2 system was developed to enable evaluation of the degradation of an already known substance, 50 mg L-1 phenol solution, but on a scale 60 times greater than S1. The efficiency of ATZ and phenol mineralization was evaluated by Total Organic Carbon (TOC). The pre-established experimental conditions were: (i) 254 nm UV-C, varying among 0, 16 and 32 W, (ii) H2O2 among 0, 50 and 100% of the theoretical value needed to complete mineralization of the pollutant, (iii) O3 (4,6 g h-1) and (iv) pH 7; 9 and 11 previously applied to all stock solutions. After assessing the best combination for degradation, it was chosen to work in the other experiments only solutions with pH 11.0. In the last stage of the study, two methods (an electric and a spectrophotometric) were developed to assess the ozone gas generation in real time and also allowing the measurement of O3 consumption during the studies. To evaluate the efficiency of the methods, analytical results were converted to % degradation or mineralization and treatment costs were estimated. Proving the feasibility of this proposal, preliminary results involving the treatment of atrazine standard solution (600 ?g L-1) had, in the best conditions (pH 11, 30 mg L-1 of H2O2 and 4,6 g L-1 of O3), efficiency equal or superior to 95% (