Relevant bibliographies by topics / Système redox

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Système redox'

Author: Grafiati
Published: 4 June 2021
Last updated: 18 February 2022

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Journal articles on the topic "Système redox"

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Ahmed, F. Z. Baba, H. Merzouk, S. Merzouk, and S. Bouanane. "P-488 – AGPI modulent le système immunitaire et le statut redox chez les enfants obèses." Archives de Pédiatrie 22, no. 5 (2015): 357. http://dx.doi.org/10.1016/s0929-693x(15)30664-3.

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Diard, JP, B. Le Gorrec, and C. Montella. "Réexamen des conditions de validité des mesures d’impédance d’un système redox. I. Transfert électronique réversible." Journal de Chimie Physique 89 (1992): 2153–67. http://dx.doi.org/10.1051/jcp/1992892153.

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Deslouis, C., M. M. Musiani, and B. Tribollet. "Transport de charges transitoire à travers des couches de polyaniline électropolymérisées sur platine, en présence d’un système redox en solution." Journal de Chimie Physique 86 (1989): 205–12. http://dx.doi.org/10.1051/jcp/1989860205.

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Raimundo, J. M., S. Akoudad, H. Brisset, and J. Roncali. "Nouveaux systèmes conjugués à états redox multiples." Journal de Chimie Physique et de Physico-Chimie Biologique 95, no. 6 (1998): 1234–37. http://dx.doi.org/10.1051/jcp:1998254.

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Garimella Uma Papa, Garimella Uma Papa, Dr K. Rajan Dr.K.Rajan, and Dr NG Renganathan Dr. NG.Renganathan. "Redox Flow Battery with Secondary Controller for Load Frequency Control in Inter Connected Power Systems." Indian Journal of Applied Research 3, no. 10 (2011): 1–3. http://dx.doi.org/10.15373/2249555x/oct2013/42.

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NAMBU, Youko, and Takeshi ENDO. "Design of Viologens for Multi." Journal of the Japan Society of Colour Material 67, no. 8 (1994): 505–12. http://dx.doi.org/10.4011/shikizai1937.67.505.

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Martre, Anne-Marie, Guy Mousset, Veronica Cosoveanu, and Virginia Danciu. "Electroréduction de dérivés dinitrés aromatiques. V. influences du matériau d'électrode et de systèmes rédox sur les réductions du 4,4′-dinitrodibenzyle et de l'acide 4,4′-dinitrostilbène-2,2′-disulfonique." Canadian Journal of Chemistry 74, no. 7 (1996): 1409–17. http://dx.doi.org/10.1139/v96-159.

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This work concerns the electrochemical and chemical reductions of 4,4′-dinitrodibenzyl and 4,4′-dinitrostilbene 2,2′-disulfonic acid under various experimental conditions. On the one hand, the electrochemical reduction is realized on Sn, monel, and Hg electrodes with or without the presence of a redox couple, and on the other hand, the chemical reduction is performed by mean of an electrochemically generated reducing agent (Sn0). According to the type of redox couple used (Ti3+/Ti4+ or sn0/sn2+), important changes in the nature and the ratio of reaction products are observed. The best conditions for obtaining di- or monoamines are defined, they correspond to 90% yield for the diamines, 70% and 50%, respectively, for 4-amino-4′-nitrodibenzyl and for 4-amino-4′-nitrostilbene-2,2′-disulfonic acid. The electrochemical behavior of the dinitro derivatives and of TiOSO4, TiCl4, and SnCl2, used as precursors of the redox couples is studied under conditions of macroscale electrolyses (5 N H2SO4–EtOH 50/50, 2.5 N H2SO4, and 10% HCl). Key words: 4,4′-dinitrodibenzyl, 4,4′-dinitrostilbene 2,2′-disulfonic acid, electrochemistry, reduction, Ti3+/Ti4+ and Sn0/Sn2+ redox systems.
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Wolter, Dietmar, Björn Zeifang, Christian Jürgens, Michael Neikes, and Andreas Wille. "Bedeutung der Keimbesiedlung von Redon-Drainage-Systemen in der Unfallchirurgie." Trauma und Berufskrankheit 2, no. 3 (2000): 216–19. http://dx.doi.org/10.1007/s100390000305.

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Lou, Marjorie F. "Redox regulation in the lens." Progress in Retinal and Eye Research 22, no. 5 (2003): 657–82. http://dx.doi.org/10.1016/s1350-9462(03)00050-8.

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Rickard, David. "Review of I.A.M. Ahmed and K.A. Hudson-Edwards (eds.) (2017): Redox-reactive minerals: Properties, reactions and applications in natural systems and clean technologies. EMU Notes in Mineralogy, 17." European Journal of Mineralogy 30, no. 3 (2018): 653–54. http://dx.doi.org/10.1127/ejm/2018/0030-2777.

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Dissertations / Theses on the topic "Système redox"

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Miché, Colette. "Equilibres redox du fer dans le système Na₂O - Al₂O₃ - SiO₂." Paris 7, 1985. http://www.theses.fr/1985PA07F083.

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Etude chimique et structurale par absorption optique et RPE du couple Fe²⁺/Fe³⁺ dans les verres binaires Na₂O-SiO₂ et ternaires Na₂O - Al₂O₃ - SiO₂: évolution du rapport Fe²⁺/Fe total en fonction de divers paramètres (composition, température), étude structurale de l'évolution des deux états de valence du fer
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Keech, Olivier. "Étude des mécanismes cellulaires lors de la sénescence foliaire." Thesis, Nancy 1, 2007. http://www.theses.fr/2007NAN10084/document.

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Lors de son jaunissement, une feuille subit aussi bien des modifications morphologiques que métaboliques. Ce processus est appelé « sénescence ». Une meilleure compréhension des mécanismes de la sénescence représente un challenge très important non seulement pour la recherche fondamentale mais aussi pour de futures applications en biotechnologie. La thèse présentée ici porte sur d’importants aspects relatifs aux mécanismes cellulaires et métaboliques rencontrés lors de la sénescence foliaire et ce, en apportant une attention particulière à l’implication des mitochondries lors de ce processus. Dans un premier temps, nous avons développé deux méthodes pour isoler, à partir de feuilles d’Arabidopsis, soit des mitochondries conservant leurs fonctionnalités, soit des mitochondries hautement purifiées. Ces méthodes furent utilisées afin d’étudier le rôle des mitochondries dans l’équilibre redox des cellules mais aussi dans le but de déterminer les capacités mitochondriales lors de la sénescence foliaire. Plus précisément, nous avons comparé l’induction de la sénescence foliaire grâce à différents traitements à l’obscurité. Cette comparaison entre des feuilles individuellement placées à l’obscurité et des feuilles provenant d’une plante entièrement disposée à l’obscurité révéla des stratégies métaboliques très différentes. En intégrant des mesures de l’activité photosynthétique, de la respiration et de microscopie laser confocale avec des analyses de transcriptomique et de métabolomique, nous suggérons que le métabolisme d’une feuille provenant d’une plante placée longuement à l’obscurité entre dans un état de « veille » dans le but de maintenir la machinerie photosynthétique fonctionnelle le plus longtemps possible; dans ce cas, les capacités mitochondriales diminuent. A contrario, les mitochondries issues de feuilles individuellement soumises à l’obscurité sont beaucoup plus actives et peuvent par conséquent fournir l’énergie et les squelettes carbonés nécessaires à la dégradation des constituants cellulaires facilitant ainsi la remobilisation des nutriments. Par ailleurs, nous avons aussi mené des investigations sur la dynamique du cytosquelette lors d’une sénescence induite par l’obscurité. La mobilité mitochondriale fut affectée dans les feuilles individuellement soumises à l’obscurité par la dégradation précoce des microtubules ce qui ne fut pas le cas dans les feuilles issues d’une plante entièrement placée à l’obscurité. De plus, un certain nombre de MAPS (microtubules-associated proteins) semblent être impliquées dans l’agrégation des microtubules autour des chloroplastes. Dans son ensemble, cette thèse apporte d’importantes informations quant aux ajustements métaboliques ainsi qu’aux mécanismes cellulaires prenant place lorsque des feuilles d’Arabidopsis sont soumises à une obscurité prolongée. En particulier, nous pensons que les mitochondries ont un rôle prépondérant lors de la sénescence foliaire et que selon le statut métabolique de la plante, les régulations mitochondriales peuvent apparaître divergentes<br>When switching from green to yellow, a leaf undergoes both morphological and metabolic changes. This process is known as senescence and improved understanding of its mechanisms is important both from a fundamental scientific perspective but also for biotechnological applications. The present thesis reports on several important aspects regarding the cellular and metabolic mechanisms occurring during leaf senescence with an emphasis on the mitochondrial contribution to this process. As a first step, we developed methods to isolate either highly functional crude mitochondria or highly purified mitochondria from leaves of Arabidopsis thaliana. These methods were further used to study mitochondrial contributions to cellular redox homeostasis and to estimate the mitochondrial capacities in leaves undergoing senescence. In particular, we compared the induction of senescence by different dark treatments in Arabidopsis. The comparison between individually darkened leaves and leaves from whole darkened plants revealed different metabolic strategies in response to darkness. Integrating data from measurements of photosynthesis, respiration and confocal laser microscopy with transcriptomic and metabolomic profiling, we suggested that metabolism in leaves of the whole darkened plants enter a “stand-by mode” with low mitochondrial activity in order to maintain the photosynthetic machinery for as long as possible. In contrast, mitochondria from individually darkened leaves are more active and may provide energy and carbon skeletons for the degradation of cell constituents, facilitating the retrieval of nutrients. We also investigated the dynamics of the microtubular cytoskeleton during dark-induced senescence. Mitochondrial mobility was affected by an early disruption of the microtubules in individually darkened leaves but not in whole darkened plants. In addition, several microtubules associated proteins (MAPs) seemed to be involved in the bundling of the microtubules around the chloroplasts. Altogether, the work presented in this thesis highlights several important steps regarding the metabolic adjustments and the cellular mechanisms in Arabidopsis leaves submitted to prolonged darkness. In particular, we suggest the mitochondria to fulfill specific and important functions during leaf senescence since the role of mitochondria in leaves experiencing prolonged darkness appears very dependant on the whole metabolic status of the plant
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Boukhenouna, Samia. "Enzymologie des étapes clés de régulation du système Peroxyrédoxine / Sulfirédoxine dans le contexte de la signalisation cellulaire redox." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0251/document.

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Les peroxyrédoxines (Prx) sont des peroxydases à thiol, ubiquitaires, qui jouent un rôle central dans la physiologie du peroxyde d’hydrogène. Une famille de Prx dite "2-Cys-Prx typique" possède une propriété unique de suroxydation de la Cys catalytique sous forme acide sulfinique, qui constitue un mécanisme de régulation des fonctions des 2-Cys-Prx typiques en tant que peroxydase, capteur de peroxyde ou protéine chaperon. La réduction des 2-Cys-Prx typiques suroxydées est catalysée par la Sulfirédoxine (Srx), une sulfinyl réductase ATP-dépendante dont la constante catalytique est de l’ordre de 1-2 min-1, une valeur faible qui doit être corrélée au rôle de Srx dans la régulation redox. L’objectif de ce travail était d’analyser l’enzymologie de la régulation du système Prx/Srx au niveau, du processus de suroxydation des 2-Cys-Prx typiques, de l’étape limitante de la Srx, et de son recyclage par les systèmes redox cellulaires. Dans un premier temps, nous avons caractérisé les deux étapes du cycle catalytique de la 2-Cys-Prx typique majeure de S. cerevisiae Tsa1, dont la compétition contrôle la sensibilité à la suroxydation, par une stratégie combinant cinétiques rapides, système enzymatique couplé et modélisation cinétique. Ces travaux suggèrent que cette compétition est contrôlée par une réorganisation conformationnelle au cours du cycle catalytique de la Tsa1. Dans un second temps, l’étude de la première étape du mécanisme catalytique de Srx, qui consiste en l’activation ATP-dépendante du groupement acide sulfinique de la 2 Cys-Prx a permis, i) de montrer que l’étape limitante de la réaction catalysée par Srx était associée au processus chimique de transfert de phosphate, et ii) de proposer un modèle d’assemblage du complexe Michaelien Prx/Srx/ATP formé lors de ce processus. Enfin, par une approche combinant cinétiques enzymatiques in vitro et génétique de la levure in vivo, nous avons établi que le mécanisme de recyclage des Srx à 1 Cys existant chez les plantes ou les mammifères implique le rôle du glutathion comme réducteur cellulaire, contrairement à la Srx de S. cerevisiae qui est recyclée par le système thiorédoxine. De façon inattendue, la spécificité du glutathion dans ce mécanisme est assurée par un événement de reconnaissance au sein du complexe Prx/Srx<br>The peroxiredoxins (Prx) are ubiquitous thiol peroxidases, which play a central role in the physiology of hydrogen peroxide. A subclass of Prx called "typical 2-Cys-Prx" has a unique property to hyperoxidize the catalytic Cys into the sulfinic acid form, which acts as a regulation mechanism of their functions, as peroxidase, peroxide sensor or protein chaperone. The reduction of the overoxidized form is catalyzed by sulfiredoxin (Srx), an ATP-dependent sulfinyl reductase whose catalytic constant is about 1-2 min-1, a low value that must be correlated to the role of Srx in redox regulation. The aim of this study was to analyze the enzymology of the regulation of the Prx/Srx system at three diffrents points of control: the hyper-oxidation process of typical 2-Cys-Prx, the rate-limiting step of the Srx mechanism and the recycling step of Srx by the cellular thiol redox systems. We have first characterized the competition mechanism between the two steps of the catalytic mechanism of the major typical 2-Cys-Prx of S. cerevisiae, Tsa1, through a strategy combining rapid kinetics, coupled enzyme system and kinetic modelling analysis. This work suggests that the sensitivity to hyper-oxidation is controlled by a conformational reorganization during the catalytic cycle of Tsa1. Next, the study of the first step of Srx catalytic mechanism, which involves the ATP-dependent activation of the sulfinic acid form of typical 2-Cys Prx i) has shown that the rate-limiting step is associated with the chemical phosphate transfer process, and ii) provided an assembly model of the Michaelien complex Prx/Srx/ATP, formed during this process. Finally, through the combination of in vitro enzyme kinetics and in vivo yeast genetic tools, we established that the recycling mechanism of one Cys Srx, existing in plants or mammals, involves the glutathione (GSH) as reducer in cells, contrary to the Srx from S. cerevisiae, which is recycled by the Thioredoxin system. Unexpectedly, our study suggests that GSH binds the thiolsulfinate complex, confirming the role of GSH as the primary reducing system of 1-Cys-Srx
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Albalat, Emmanuelle. "Fractionnement isotopique de l'Erbium et de l'Ytterbium dans le système Terre-Lune." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2012. http://tel.archives-ouvertes.fr/tel-00780334.

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Nous avons développé une méthode pour analyse isotopique de Yb et Er, deux terres rares aux propriétés chimiques identiques et aux températures de condensation différentes, avec comme objectifs (1) de déterminer la variabilité isotopique de ces éléments dans les processus pétrologiques terrestres, et (2) de comparer leurs compositions isotopiques dans les chondrites, la Terre et la Lune afin de déterminer le rôle potentiel de la condensation à haute température à partir de vapeurs qui a suivi l'impact géant à l'origine de la formation de la Lune. Les résultats obtenus montrent une plus grande variabilité des fractionnements isotopiques de Yb par rapport à ceux d'Er. Deux effets contribuent à cette différence : un effet oxydo-réducteur et un effet de température. La corrélation positive obtenue entre la composition isotopique en Yb, et le rapport La/Yb dans les échantillons terrestres, peut être interprétée par la présence d'une faible fraction d' Yb(2+), Yb étant majoritairement présent sous la forme Yb(3+). La kimberlite (liquide magmatique formé par un faible taux de fusion partielle) est enrichie en isotopes lourds et les grenats, résidus de fusion partielle, sont isotopiquement légers, tandis que les basaltes de ride ou d'îles ont des compositions isotopiques intermédiaires.La composition isotopique en Yb de la Lune est enrichie en isotopes légers par rapport à celle de la Terre et des chondrites. Dans le disque proto-lunaire, les frictions entre les phases fondues et gazeuses favorisent la migration des premiers condensats très réfractaires et enrichis en isotopes lourds vers la Terre, et celle de la vapeur enrichie en isotopes légers, vers l'extérieur, au-delà de la limite de Roche à partir de laquelle la Lune s'accrète. Ceci est un nouvel argument en faveur de la condensation de la Lune à partir de vapeur générée par un impact géant. La mesure de la composition isotopique d'Er dans les échantillons lunaires reflète pour la première fois la capture par 167Er des neutrons produits par interaction du rayonnement cosmique galactique avec la surface lunaire. L'apport de Er aux systèmes communément utilisés pour déterminer le spectre d'énergie des neutrons d'un matériau peut permettre de couvrir une gamme énergétique plus large et de disposer ainsi d'un proxy plus complet pour l'étude des histoires des irradiations des matériaux planétaires.
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Gütle, Desirée. "Characterization of the ferredoxin/thioredoxin system and its targets in Physcomitrella patens." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0055/document.

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La régulation redox est un mécanisme ancien présent chez les organismes biologiques et impliquée dans diverses voies métaboliques. En particulier chez les organismes photosynthétiques elle est responsable des mécanismes d‘adaptation rapide dans un environnement constamment modifié. Dans les chloroplastes le système ferrédoxine/thiorédoxine est la cascade redox principale qui relie l‘activité de plusieurs enzymes plastidiales à la source lumineuse. Le rôle central dans ce système est joué par la ferrédoxine-thiorédoxine réductase (FTR), une protéine hétérodimérique qui récupère des électrons à partir de la ferrédoxine photoréduite et les transfère pour réduire des thiorédoxines plastidiales. Ces protéines peuvent alors réduire des enzymes cibles, requérant l‘accessibilité de paires de cystéines dans un disulfure dont la réduction résulte en une activation/ inactivation de la cible. Jusqu‘à présent des plantes viables n‘ont pu être obtenues en l‘absence de ce système de régulation. Dans cette thèse des secteurs du système redox ont été explorés chez la plante modèle Physcomitrella patens (une mousse). Par manipulation de gènes l‘influence de l‘enzyme FTR sur la croissance et le développement de la plante a été analysée suivant différents paramètres. De manière à impacter la fonction de la réductase des changements nucléotidiques simples ont été introduits au niveau des codons programmant les cystéines catalytiques et dans un deuxième temps le gène complet a été supprimé. De façon inattendue nous n‘avons observé aucun effet significatif sur la viabilité et le développement des plantes mutantes. De plus, nous avons détecté dans P. patens des thiorédoxines additionnelles absentes chez les plantes à graine qui sont fonctionnelles vis à vis des enzymes cibles mais non-réduites par la FTR. Ceci rend possible un scénario de compensation chez les mutants via un système de réduction FTR-indépendant qui reste à caractériser. Deux des cibles photorégulées, la fructose-1,6-bisphosphatase (FBPase) et la sédoheptulose-1,7-bisphosphatase (SBPase), fonctionnent dans la phase de régénération du cycle de Calvin-Benson cycle et elles possèdent plusieurs caractéristiques de catalyse et de régulation similaires. En combinant des approches biochimiques et structurales, une comparaison fonctionnelle et structurale des deux phosphatases de P. patens a été conduite. De plus l‘analyse phylogénétique a révélé une origine procaryotique indépendante des deux séquences en dépit de leurs similitudes structurales et catalytiques. De plus trois articles de revue résument la plasticité et la représentativité du modèle P. patens pour la recherche forestière, les principes généraux de la régulation redox relativement aux aspects évolutifs et fonctionnels chez les plantes ainsi que l‘ état de l‘art de la régulation redox chez les espèces ligneuses en utilisant principalement le peuplier comme modèle<br>Redox regulation is an ancient mechanism present in biological organisms and is involved in diverse cellular pathways. In particular in photosynthetic organisms it is responsible for fast adaption mechanisms to a constantly changing environment. In chloroplasts the ferredoxin/thioredoxin system represents the main redox regulatory cascade which links the activity of several plastid enzymes to the energy source, light. A central role in this system is played by the heterodimeric ferredoxin-thioredoxin reductase (FTR), which gains electrons from the photo-reduced ferredoxin and transfers those further on via reduction to plastidal thioredoxins. Those proteins in turn reduce their target enzymes and require therefore the availability of redox sensitive cysteine pairs whose reduction results in an inactivation/activation switch of the targets. So far no viable plants could be obtained in complete absence of this redox regulation system. In this thesis single sections of the system were explored in the model plant Physcomitrella patens. Through gene manipulation the influence of the FTR enzyme on plant growth and development was analysed. In order to impact on the function of the reductase, firstly single nucleotide exchange of the catalytic cysteines was performed and later on the gene was completely deleted. Surprisingly, no significant effect could be observed on the viability and development of mutant lines compared to WT plants. Furthermore we found that P. patens possesses in contrast to seed plants additional thioredoxins which are functional for reduction of FTR target enzymes but are most likely not supplied with electrons by this reductase. Thus a possible rescue scenario independent of FTR could be assumed for P. patens and also by other redox regulation systems present in chloroplasts. Two of the FTR target enzymes, fructose-1,6-bisphosphatase and sedoheptulose-1,7-bisphosphatase, are functional in the regeneration phase of the Calvin-Benson cycle and share similar characteristics in regulation and catalysis. By combining biochemical and structural approaches, a functional comparison of both phosphatases was conducted using cDNAs from P. patens. A stricter TRX-dependent regulation and catalytic cleavage ability for both substrates, FBP and SBP, could be observed for PpSBPase, whereas PpFBPase is only capable of cleaving FBP. By obtaining the oxidized X-ray structure of both enzymes these observations can be associated with the distinct positions of regulatory sites and the various sizes of the substrate binding pocket. In addition, the phylogenetic analysis revealed an independent prokaryotic origin for both phosphatases. Furthermore we summarized in three review articles the amenability of P. patens as model plant for forest research, the general principles of redox regulation in respect of evolution and functional mechanisms in plants, and the current state of the art in forest redox regulation using poplar as exemplary model
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Heurtaux, Tony. "Modulation de l'activité de glucuronoconjugaison et de l'expression de l'isoforme UGT1A6 cérébrale lors d'un stress oxydant ou d'une inflammation : rôle du statut redox intracellulaire." Nancy 1, 2005. http://docnum.univ-lorraine.fr/public/SCD_T_2005_0208_HEURTAUX.pdf.

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Les astrocytes constituent une population de cellules cérébrales dont les fonctions se révèlent très importantes pour un fonctionnement optimum du cerveau. En effet, ils participent à la fourniture de nutriments aux neurones, ainsi que de précurseurs et de facteurs de croissance; ils participent également à leur activité fonctionnelle en maintenant l'homéostasie de l'environnement neuronal, et en fin, ils assurent la différenciation des cellules endothéliales cérébrales, dont les propriétés spécifiques constituent une structure fonctionnelle très importante, la barrière hémato-encéphalique (BHE). Située à l'interface entre le sang et le cerveau, la BHE permet de contrôler rigoureusement les échanges moléculaires entre le sang et le parenchyme cérébral. Cette barrière est nécessaire afin de protéger le cerveau des agressions extérieures et de maintenir son homéostasie. En plus d'être une barrière physique, la BHE est également considérée comme une barrière métabolique car dotée d'enzymes intervenant dans la biotransformation des xénobiotiques. Les activités enzymatiques observées sont beaucoup plus faibles dans le cerveau que dans les autres organes, mais il est évident que celles-ci présentent tout de même un rôle de protection significatif. De ce fait, les caractéristiques de la BHE peuvent modifier considérablement l'efficacité des médicaments à visée cérébrale. Notre travail a été consacré à l'étude d'enzymes du métabolisme des médicaments, les UDP-glucuronosyltransférases (UGT), dans un modèle cérébral in vitro constitué par des cultures primaires d'astrocytes de rats ainsi que dans un modèle in vivo. Plus précisément, sachant qu'un état inflammatoire perturbe fortement les propriétés de la BHE, nous avons cherché à déterminer les conséquences que pouvaient avoir des conditions pro-inflammatoires sur la glucuronoconjugaison astrocytaire. Notre travail a permis de démontrer une diminution des activités astrocytaires de glucuronoconjugaison suite à un stress oxydant induit par la ménadione. Cette diminution d'activité est liée à une perturbation de l'état redox intracellulaire et une augmentation de l'oxydation des protéines. Cependant, au cours du temps, nous observons un rétablissement des activités enzymatiques consécutif à la surexpression d'isoformes d'UGT et notamment de l'UGT1A6, isoforme majoritaire au niveau astrocytaire. Le modèle pro-inflammatoire, mis en place par traitement de nos cultures avec des parois de bactéries (lipopolysaccharide, LPS), provoque une augmentation de la glucuronoconjugaison. L' état redox intracellulaire reste inchangé, cependant la production de médiateurs pro-inflammatoires, dans ces conditions, est à l'origine de mécanismes intracellulaires menant à la surexpression de l'UGT1A6. Parallèlement, nous n'avons pu vérifier ces résultats chez le rat, après injection de LPS par voie intrapéritonéale. En conclusion, ces travaux présentent de nouvelles données concernant les UGT cérébrales. Nous avons montré leur sensibilité au stress oxydant ainsi que leur perturbation lors d'états pro-inflammatoires. Dans de telles conditions, la glucuronoconjugaison est modifiée et peut entraîner une diminution ou une augmentation du métabolisme de composés endogènes et exogènes. Ces perturbations pourraient alors engendrer une toxicité cérébrale de la molécule administrée ou une diminution de l'efficacité thérapeutique de cette molécule.
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Rallakis, Dimitrios. "Le système métallogénique et le piège redox dans le gisement d’uranium de type roll-front de Zoovch-Ovoo, Mongolie. Rôle des porteurs du carbone et du soufre." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0079.

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L'objectif de la thèse concerne l'analyse du système matières organiques (carbone)-uranium-sulfure qui contrôle la formation du gisement d'uranium de type de roll-front au Zoovch Ovoo (Mongolie). La formation Cénomanienne du Sainshand est constituée de sédiments continentaux silicoclastiques déposés dans des milieux fluvio-lacustres. Le système global est en début de diagénèse et n'a pas été affecté par un enfouissement significatif, estimé à moins de 600 m pour une température maximale de 40°C. Le réservoir se caractérise par des sables non consolidés et des argiles silteuses. Parfois, certains lits de grès d’épaisseur décimétriques sont cimentés par des carbonates et disposés au sein de faciès silicoclastiques non consolidés. L’étude systématique des grès à ciment carbonaté a révélé la présence exclusive de dolomite. Quatre types de dolomite différents ont été reconnus. Tous ont été formés par des eaux d'origine météorique et présentent des caractéristiques isotopiques (C, O) semblables. Ils sont génétiquement liés les uns aux autres, avec de possibles épisodes de recristallisation impliquant une réincorporation progressivement moindre des éléments en traces comme les terres rares et le manganèse. Le premier type de dolomite est contrôlé par les conditions de sédimentation, tandis que les trois suivants sont contrôlés par diagenèse. Le troisième type de dolomite n'a été trouvé que dans des échantillons ayant été affectés par le roll-front alors que le quatrième est postérieur aux porteurs d'uranium. La matière organique détritique est très abondante et joue un rôle majeur dans le piégeage de l’uranium aux côtés de la pyrite. L'étude en pétrographie organique a montré que toute est d'origine végétale supérieure et immature, comme l'ont montré les mesures de réflectance de la vitrinite (&lt;0,4%). Elle est exclusivement présente sous forme de particules détritiques et sa distribution est donc régie par l’évolution des conditions de dépôt sédimentaires. Huit générations de pyrite ont été identifiées sur la base textures et des associations minérales, avec trois types majeurs : les pyrites framboidales en sphérolites isolés, les surcroissances automorphes, et les pyrites de remplacement (épigénie). L'étude isotopique du δ34S de la pyrite a montré qu’une grande parties des pyrites s‘est formée par bio-réduction des sulfates. Les porteurs de l’uranium sont la pechblende et dans une moindre mesure la phospho-coffinite. La pechblende cimente et remplace la matière organique mais aussi les pyrites automorphes corrodées ce qui indique que l’enrichissement ou l’introduction massive de l’uranium s’est produit assez tardivement. La matière organique a piégé l’uranium de manière diffuse à des fortes concentrations, sous une forme minéralogique non accessible au MEB. Il peut s’agir de nanophases de pechblende de taille inférieure à la centaine de nanomètres. Pour expliquer ces concentrations, une préconcentration ne peut pas être totalement exclue ou un processus de diffusion piégeage lors du stade de minéralisation. La considération de l’ensemble des données indique que l’aquifère principal a été le siège probable d’activité microbienne subcontinue, qui est attestée par la formation à différentes stades de l’histoire du bassin de pyrites dont les caractéristiques isotopiques indiquent des processus complexes de fractionnement. La présence de matière organique en quantité significative et des pyrites peut expliquer l’efficacité du piège redox pour la réduction de l’uranium. Le modèle métallogénique présenté est celui d’un système mixte où un processus de type roll-front lié aux caractéristiques sédimentologiques de cette zone se superpose à un piège redox particulier dont la chimie C-S-U est assistée par les bactéries<br>The objective of the PhD thesis concerns the analysis of the processes governing the carbon-uranium-sulfide system in the aquifers of the roll-front type Zoovch Ovoo uranium-deposit (Mongolia). The Cenomanian Sainshand Formation hosting the ore deposit contains reservoirs made of silicoclastic sediments deposited in fluvio-lacustrine settings mostly characterized by unconsolidated silty clays and sands ranging from arenite to sub-arkose. Occasionally some decimetres thick sandstone beds are dolomite cemented. Four different dolomite fabrics are recognized and classified according to their crystal boundaries and geochemistry. Isotopic analysis indicates that they were formed from meteoric waters with the carbon source being probably the detrital material itself issued from basement rock erosion. Dolomites are genetically related to each other with possible recrystallization episodes that are indicated by gradual depletion in REE and Mn. The first dolomite type was depositionally controlled, while the next three parageneses are diagenetic. The third dolomite type is found only in samples that have experienced roll-front waters, whereas the fourth post-dates uranium formation. As a result the dolomite cements paragenetic evolution is used as reference to document the whole burial history of the deposit. Organic matter particles, pyrite and uranium are very intimately related. Organic matter present in clay, silt and sand is always represented by poorly preserved detrital elements of higher plant origin and is very immature (peat stage; vitrinite reflectance &lt;0.4%). At the scale of the sedimentary particles, organic matter complexes U(VI). However, despite a systematic association to UO2, it cannot be considered as directly involved in the reduction mechanism of uranium because of the low burial temperatures (max 50°C) and hence very limited diagenesis. Nevertheless, the investigation reveals that organic matter is the most important element in the U trapping process. Indeed, it acts as a substrate sustaining and focusing bacterial activity into specific sedimentary layers. In turn the microbial communities catalyze the reduction of sulfur, iron and especially uranium leading to two major consequences: 1) the precipitation of UO2 onto organic matter particles and 2) the formation of pyrite which acts as an additional reducer for U(VI). It appears that the uranium ore deposit at Zoovch Ovoo is primarily controlled by the distribution of the detrital organic matter in the sedimentary system as well as by the permeability network allowing the input of S, U and micro-organisms. The rather shallow aquifers probably underwent a nearly continuous bacterial activity which is responsible of many chemical features and processes controlling the U and sulfide precipitation. However, main uranium deposition events occur since the beginning of exhumation when enhanced fluid movement sustains roll-front activity. The latter displaces and combines the ingredients of the biochemical trap, allowing progressive enrichment in uranium through time
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Modiba, Portia. "Electrolytes for redox flow battery systems." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/3999.

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Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2010.<br>Electrochemical behaviour of Ce, Fe, Cr,V and Mn in the presence of DTPA, EDTA, EDDS, NTA ligands were investigated by using cyclic voltammetry, a rotating disc electrode and electrochemical impedance spectroscopy for use in redox flow battery (RFB) systems. RFB is currently used for energy storage, the vanadium, which is used in most of the RFB’s, however suffers from species crossover and sluggish reactions, which limit the lifetime of the battery. These various ligands and metal complexes mentioned above where all examined to identify the suitable and favoured electrolyte that can be used for a RFB system. Kinetic parameters such as potential, limiting current, transfer coefficient, diffusion coefficients, and rate constants were studied. RDE experiments confirmed that the parameters measured by CV are similar under hydrodynamic conditions and can be used to determine the kinetic parameters of the redox couples. The use of DTPA as a ligand for complexation of Ce(IV) gave more favourable results compared to other ligand with various metal complexes used in this study [1-3]. The results of kinetic studies of Ce(IV)–DTPA complex shows promise as an electrolyte for a redox flow battery. The separation of V(IV)/(V), Fe (III)/(IV),Cr(III)/(IV),Mn (III)/(IV) and Ce(III)/(IV) with various ligands (EDTA, EDDS, NTA and DTPA) were also investigated using capillary electrophoresis. To understand the speciation of these metal complexes as used in this study and particularly the vanadium, for the reason that it has a complicated (V) oxidation state. The charge/discharge performance of all electrolytes used in this work was determined and a high voltage achieved when Ce-DTPA was used, and it is compared to that of the vanadium electrolyte currently in use. This was evaluated with systems studied previously. Therefore, Ce-DTPA will be a suitable electrolyte for redox flow battery systems.
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Kennedy, Andrew A. "Biomimetic models for redox enzyme systems." Thesis, University of Glasgow, 2009. http://theses.gla.ac.uk/1060/.

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Supramolecular chemistry involves the study of noncovalent interactions that take place between molecules. A supramolecule or host-guest complex is formed when a noncovalent binding or complexation event occurs between two such molecules. Hydrogen bonds, electrostatics, pi-stacking, hydrophobic effects, solvatophobic effects and van der Waals forces are all types of noncovalent interactions. Biological systems have provided much of the inspiration for the development of supramolecular chemistry, and many synthetic supramolecular systems have been designed to mimic biological and enzymatic processes. Biomimetic modelling involves the synthesis of compounds containing similar functional groups to that of the specific enzyme?s protein and cofactor. Subsequent analysis using chemical, physical or computational techniques can be used to gain a better understanding of the interactions taking place. This study involves the investigation of various biomimetic redox enzyme systems. Firstly, model systems containing the 1- and 5-deazaflavin cofactor have been synthesised and studied to probe how their redox behaviour compares to that of riboflavin in a supramolecular environment using physical, electrochemical and computational techniques. Secondly, this study has focussed on the flavin cofactor but has expanded upon what factors influence its redox behaviour, and ability to noncovalently interact with other molecules, by examining how the presence of different dendritic architectures can affect its redox properties and noncovalent behaviour. A series of dendrons have been synthesised and studied that have a water-soluble dendron architecture attached to the flavin moiety, as well as a series of dendrons with branching designed to encapsulate the flavin unit. Finally, a biomimetic model of the pyrroloquinoline quinone cofactor has also been synthesised and studies carried out to investigate its redox behaviour in a supramolecular environment, and ability to noncovalently interact with other molecules. The results of this study will hopefully contribute significantly to the body of chemical research in the area of supramolecular chemistry and biomimetics. Of particular interest will be the results from the flavin-based dendron research, as the prospect of purpose-built synthetic enzymes, designed and synthesised for whatever role is required, would surely be of great significance.
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Bergamini, Giacomo <1979&gt. "Photo-and redox-active supramolecular systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/475/.

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Books on the topic "Système redox"

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Hirao, Toshikazu, ed. Functionalized Redox Systems. Springer Japan, 2015. http://dx.doi.org/10.1007/978-4-431-55306-9.

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Nishinaga, Tohru, ed. Organic Redox Systems. John Wiley & Sons, Inc, 2016. http://dx.doi.org/10.1002/9781118858981.

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Hirao, Toshikazu, ed. Redox Systems Under Nano-Space Control. Springer-Verlag, 2006. http://dx.doi.org/10.1007/3-540-29580-1.

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Organic redox systems: Synthesis, properties, and applications. John Wiley & Sons, 2016.

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Genesis redux: Experiments creating artificial life. Windcrest/McGraw-Hill, 1994.

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1916-, King Tsoo E., Mason Howard S, and Morrison Martin, eds. Oxidases and related redox systems: Proceedings of the 4th International Symposium on Oxidases and Related Redox Systems held in Portland, Oregon, October 4-8, 1987. A.R. Liss, 1988.

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Asard, Han, Alajos Bérczi, and Roland J. Caubergs, eds. Plasma Membrane Redox Systems and their Role in Biological Stress and Disease. Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-2695-5.

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Hirao, Toshikazu, and Various. Redox Systems Under Nano-Space Control. Springer, 2010.

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Redox Systems Under Nano-Space Control. Springer, 2006.

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Nishinaga, Tohru. Organic Redox Systems: Synthesis, Properties, and Applications. Wiley & Sons, Incorporated, John, 2015.

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Book chapters on the topic "Système redox"

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Schüring, J., M. Schlieker, and J. Hencke. "Redox Fronts in Aquifer Systems and Parameters Controlling their Dimensions." In Redox. Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-662-04080-5_11.

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Latscha, Hans Peter, Helmut Alfons Klein, and Klaus Gulbins. "Redox-Systeme." In Chemie für Laboranten und Chemotechniker. Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-96945-4_9.

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Latscha, Hans Peter, Helmut Alfons Klein, and Rainer Mosebach. "Redox-Systeme." In Chemie für Pharmazeuten und Biologen I. Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-72962-1_21.

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Latscha, Hans Peter, and Helmut Alfons Klein. "Redox-Systeme." In Springer-Lehrbuch. Springer Berlin Heidelberg, 1994. http://dx.doi.org/10.1007/978-3-662-05760-5_9.

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Latscha, Hans Peter, and Helmut Alfons Klein. "Redox-Systeme." In Springer-Lehrbuch. Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-662-05761-2_9.

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Latscha, Hans Peter, and Helmut Alfons Klein. "Redox-Systeme." In Springer-Lehrbuch. Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-662-05762-9_9.

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Latscha, Hans Peter, and Helmut Alfons Klein. "Redox-Systeme." In Anorganische Chemie. Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-662-05763-6_9.

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Latscha, Hans Peter, Helmut Alfons Klein, and Klaus Gulbins. "Redox-Systeme." In Chemie für Laboranten und Chemotechniker. Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-58111-3_9.

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Kofod, M. "Variance of the Redox Potential Value in Two Anoxic Groundwater Systems." In Redox. Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-662-04080-5_10.

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Peiffer, S. "Characterisation of the Redox State of Aqueous Systems: Towards a Problem-Oriented Approach." In Redox. Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-662-04080-5_3.

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Conference papers on the topic "Système redox"

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Kienzler, Bernhard, and Gunnar Buckau. "The Collaborative EC Project ReCosy." In ASME 2009 12th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2009. http://dx.doi.org/10.1115/icem2009-16203.

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The Collaborative Project (CP) ReCosy (Redox Controlling Systems) was established in 2008. It falls within the EURATOM program and is implemented within the European Commission’s 7th Framework Program. Main objectives of CP ReCosy are the sound understanding of redox phenomena controlling the long-term release/retention of radionuclides in nuclear waste disposal and providing tools to apply the results to Performance Assessment/Safety Case. Although redox is not a new geochemical problem, different questions are still not resolved and thus raised by implementers and scientists. Radionuclide redox transformations on minerals are considered to be decisive scenarios in various FEP lists. 32 institutions from 13 European countries contribute to the 4-years CP by i) development of advanced analytical tools, ii) investigations of processes responsible for redox control (thermodynamically and kinetically controlled processes, surface reactions and microbial processes), iii) provision of required data on redox controlling processes, and iv) response of the disposal systems to external/internal disturbances. Systems which are investigated comprise simple very well defined ones under controlled laboratory conditions, complex laboratory systems, near-natural systems in the laboratory, real systems, and near-field systems controlled spent nuclear fuel. The scientific results of the CP ReCosy are reported during annual workshops (AW). The first AW took place in February 10–12, 2009. The scientific contributions underwent a peerreview and are published in the form of workshop proceedings together with scientific-technical overview papers of the different project workpackages. The present paper summarizes the main results obtained after the first year of ReCosy. The status during the project preparation phase of the CP ReCosy is published elsewhere [1].
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Brendelberger, Stefan, Jan Felinks, Dominik Kolb, and Christian Sattler. "Particle Conveyer for Solar Thermo-Chemical Processes and Related Solid Heat Recovery Systems." In ASME 2016 10th International Conference on Energy Sustainability collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/es2016-59577.

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On the way to a de-carbonized economy by 2050 new technologies have to be developed and deployed into the market. In solar driven thermochemical processes concentrated solar radiation is used as a renewable high temperature heat source to drive a chemical reaction. These processes are promising pathways for the production of gaseous and liquid fuels and therefore they can provide sustainable chemical energy carriers with inherent long-term storage capabilities. Amongst these processes, redox cycles for the production of syngas from water and carbon dioxide received considerable interest due to their high theoretical process efficiencies. In these processes a redox material is reduced using high temperature heat which is provided by concentrated solar radiation. In a second reaction, at considerably lower temperatures, the redox material is oxidized while splitting water or carbon dioxide. One requirement for the design of efficient redox processes is a high recovery rate of the sensible heat of the solid redox material. In recent redox process concepts the use of inert heat transfer particles in combination with a particulate redox material has been proposed. Amongst other benefits this methodology allows to recover heat from the redox material. A corresponding solid-solid heat recovery system is under development. In a single stage the heat recovery unit acts as a co-current heat exchanger. By combining several units and by using a proper flow path a quasi-counter-current heat exchanger can be obtained. Such a heat recovery system requires that particles are lifted at temperatures well above 1100°C. These high temperatures require a simple design, decent thermal insulation and the thermal shielding of all moving parts and engine. The present work is dealing with the development of a respective conveying system which can be operated at the targeted temperatures, while heat losses are prevented as far as possible. A lab scale version of the conveyer is constructed and tested. A numerical model of the conveyer is developed and validated using results of an experimental campaign with particles at 1150°C. The next step in the assessment of the conveyer system is the analysis of the performance of a scale up version. A generic process analysis will be conducted to obtain operational and design requirements of the scale up conveyer. A detailed scale up version is developed accordingly and the validated numerical model is applied to this design to predict the heat losses during the particle lifting and to discuss their impact on the total process performance.
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Marino, Chris, Travis M. Hery, and Vishnu-Baba Sundaresan. "Redox Transistor Battery: An Emerging Architecture for Electrochemical Energy Storage." In ASME 2017 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/smasis2017-3928.

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In this article, it is proposed that a membrane with tunable ionic conductivity can be used as a separator between the electrodes of a supercapacitor to both allow normal charge/discharge operation and minimize self-discharge when not in use. It is shown that the redox active conducting polymer PPy(DBS), when polymerized on a porous substrate, will span across the pores of the membrane. PPy(DBS) is also shown to function as an ionic redox transistor, in which the transmembrane ionic conductivity of the polymer membrane is a function of its redox state. The PPy(DBS) ionic redox transistor is applied between the electrodes in a supercapacitor as a smart membrane separator. It is demonstrated that the maximum tunable ionic conductivity of the smart membrane separator is comparable in operation to an industry standard separator at maximum ionic conductivity, with a self-discharge leakage current of ∼0.12mA/cm2 at 1V. The minimum tunable ionic conductivity of the smart membrane separator is shown to decrease the supercapacitor self-discharge when not in use by a factor of 10, with a leakage current of 0.012mA/cm2 at 1V. This range of tunable ionic conductivity could lead to the emergence of redox transistor batteries with high energy density and low self-discharge for short and long-term storage applications.
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Northcutt, Robert G., John M. Thornton, and Vishnu Baba Sundaresan. "An Investigation of Morphology Dependent Charge Storage in Polypyrrole Membranes." In ASME 2014 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/smasis2014-7411.

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PPy-based membranes exchange ions with electrolyte through reversible redox processes and hence are best suited as electrodes for batteries and super capacitors. The energy density of batteries and super capacitors are dependent on the specific capacitance of the conducting polymer and can be represented through a mechanistic model for ion transport. Through this model, the specific capacitance of polypyrrole-based membranes is shown to be dependent on the number of accessible redox sites at the electrolyte-polymer interface. The accessibility of redox sites at the electrolyte-polymer interface can be increased by controlling the morphological properties and distribution of dopant in the polymer backbone. Thus, by nanostructuring and by controlling the distribution of the dopant in the polymer, we have shown that the capacitance of PPy-based membranes can be increased to 490 F.g−1 for a 50 mV.sec−1 scan rate and 0.6 g.cm−2 specific mass. Despite this value of specific capacitance being the highest reported for PPy-based membranes to date, it is estimated that only 69% of active redox sites are used for ion storage and hence can be increased further. Maximizing specific capacitance requires an understanding of spatial distribution of redox sites in the polymer backbone and its corresponding chemoelectrical activity. In order to generate a spatial map of ion storage in PPy-based membranes, this article presents for the first time a shear-force (SF) based topography imaging and scanning electrochemical microscopy (SECM) imaging of the PPy(DBS) under reduced and oxidized conditions. From a correlated topography and chemoelectrical activity of PPy-based membrane, the data shows the availability of redox sites in the polymer and it is projected that this result will enhance the design and nanostructuring of PPy-based membranes and distribution of dopant in the backbone.
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Holzemer-Zerhusen, Philipp, Stefan Brendelberger, Martin Roeb, and Christian Sattler. "Oxygen Crossover in Solid-Solid Heat Exchangers for Solar Water and Carbon Dioxide Splitting: A Thermodynamic Analysis." In ASME 2020 14th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/es2020-1608.

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Abstract In solar thermochemical redox cycles for H2O/CO2-splitting, a large portion of the overall energy demand of the system is associated with heating the redox material from the oxidation temperature to the reduction temperature. Hence, an important measure to improve the efficiency is recuperation of sensible heat stored in the redox material. A solid-solid heat exchanger can be subject to undesirable oxygen crossover, which decreases the oxygen uptake capacity of the redox material and consequently the system efficiency. We investigate the extent of this crossover in ceria based cycles, to identify, under which conditions a heat exchanger that allows oxygen crossover can improve the system efficiency. In a thermodynamic analysis we calculate the amount of transferred oxygen as a function of the heat exchanger efficiency and show the system efficiency of such a concept. A second law analysis is applied to the model to check the feasibility of calculated points of operation. For the investigated parameter set the heat exchanger design improves the system efficiency by a factor of up to 2.1.
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Itoh, Takefumi, Takashi Kanno, Atsuo Ikeuchi, Kouhei Kawai, Takushi Hara, and Nobuyuki Tokuda. "Development of Vanadium Redox Flow Battery System." In 34th Intersociety Energy Conversion Engineering Conference. SAE International, 1999. http://dx.doi.org/10.4271/1999-01-2616.

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Huang, Zhiyong, Fazhi He, Xiantao Cai, Xiaoxia Li, and Yuan Cheng. "A Group Undo/Redo Mechanism to Preserve User Intention in Replicated Collaborative Modeling Systems." In ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/detc2009-87244.

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Undo/redo mechanism is an important issue in interaction-centered CAD system. Since the design task is a creative process, the users of CAD systems have to use undo/redo mechanism to repeatly modify the CAD model in order to achieve a satisfied result. However, undo/redo mechanism is not an easy work even in standalone CAD systems. This is the reason why different commercial CAD systems are equipped with different level of undo/redo mechanism. Therefore, group undo/redo mechanism in collaborative system becomes a special challenge. This paper proposed a group undo/redo method in replicated collaborative modeling system. In our method, one user’s operation intention can be preserved in both local site and remote sites. The preservation is based on dependency relationship among users at different sites. The implementation of the Undo/Redo operation in both local site and remote site is described in detail respectively. The proposed approach has been tested in a prototype system with case study. The authors believe that this work represents the first attempt to address group undo/redo mechanism in collaborative CAD systems.
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Cook, Korey, Ethan Lau, Jordan Thayer, Shane Mann, Tom Guarr, and Andre Benard. "Development of a Membraneless Organic Redox Flow Battery." In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-88024.

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The development of a novel electrochemical energy storage system, specifically a redox flow batteries (RFB), is discussed in this work. It has the distinction of not requiring an ion-selective membrane due to novel chemical compounds. The techno-economic aspects of a low-cost 3D printed flow cell and system design tailored for a novel chemistry is discussed. The organic compounds employed are inexpensive, have a long lifespan, and as mentioned enable the system to be membraneless. All these substantially decrease the capital and maintenance costs. Suitable systems were developed and tested using chemically compatible 3D printed materials for the flow cells. The estimated cost per kWh is lower than the Department of Energy’s target cost of $150/kWh for grid storage capacity. A commercial scale system, rated for a 1 MW, 5-hour discharge time, has an estimated cost of $65/kWh. The proposed technology could revolutionize the energy storage industry and help with the construction of a more stable and efficient energy grid.
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Hashimoto, S., H. Watanabe, T. Sakamoto, et al. "The Design and Development of an Evaluation System for Redox Characteristics of Anode Supported SOFCs Using In-Situ Acoustic Emission and Electrochemical Technique." In ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2012 6th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fuelcell2012-91156.

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In this study, a redox evaluation system for anode supported SOFCs using in-situ acoustic emission (AE) and electrochemical technique has been developed. The system consists of a gas blending unit, moisture controlling unit, AE cell evaluation probe, gas cooling exhaust, electrochemical cell test system and AE signal measurement system. The anode supported coin cells, which have the same thickness dimension as practical SOFCs have, can be evaluated under temperature and atmosphere controlled conditions. The oxygen partial pressure in the anodic atmospheres can be gradually controlled from air to reducing atmosphere using the gas blending unit which is connected to 6 gas cylinders. Humidity in the anodic atmospheres can be controlled by moisture controlling unit which consists of 2 bubblers form 0.86% (5°C saturation) up to 80% (94°C saturation). Redox process of the anode can be simulated in this system by controlled three oxidation modes, i.e. O2 gas oxidation, steam oxidation and electrochemical oxidation, which correspond to actual troubles, i.e. gas leakage, degradation of downstream and fuel depletion, respectively. An AE transducer can monitor the cell condition via an inner tube for a guide of exhaust from the cathode. Redox cell test for the anode supported coin cell has been examined at 770°C using this system. After the reduction of the anode substrate in moist H2, current 0.5Acm−2 loaded to the cell. And then H2 gas concentration had been reduced by stages. The cell voltage was down to below −6V after H2 gas concentration was reduced to pH2 = 2%. This drastic cell voltage drop and AE signal generation occurred at the same time. It is considered that Ni re-oxidation with fracture started at this time. Local delamination between anode and electrolyte, and also cracks at the electrolyte and cathode were observed after redox test. It was confirmed that AE sensing is effective for redox evaluation.
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Abe, Ryu, Kazuhiro Sayama, and Hironori Arakawa. "Dye-Sensitized Photocatalyst System for Water Splitting Into H2 and O2 Under Visible Light Irradiation." In ASME 2004 International Solar Energy Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/isec2004-65070.

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H2 production from a water-acetonitrile mixed solution containing iodide electron donor was investigated over dye-sensitized Pt/TiO2 photocatalysts under visible light irradiation, as a part of water splitting system using iodide redox mediator. The rates of H2 evolution were decreased with the increase of the water ratio in the mixed solutions, because of the decrease in energy gap between the redox potential of I3−/I− and the HOMO levels of the dyes, which lowing the efficiency of electron transfer from I− to dye.
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Reports on the topic "Système redox"

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LORIER, TROY. SB3 Phase 2 Variability Study: The impact of REDOX on Durability for the FRIT 418-SB2/3 System. Office of Scientific and Technical Information (OSTI), 2004. http://dx.doi.org/10.2172/822652.

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Bergren, Adam Johan. Electron Transfer Reactivity Patterns at Chemically Modified Electrodes: Fundamentals and Application to the Optimization of Redox Recycling Amplification Systems. Office of Scientific and Technical Information (OSTI), 2006. http://dx.doi.org/10.2172/888934.

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Bergren, Adam Johan. Electron transfet reactivity patterns at chemically modified electrodes: fundamentals and application to the optimization of redox recycling amplification systems. Office of Scientific and Technical Information (OSTI), 2006. http://dx.doi.org/10.2172/882891.

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SMITH, MICHAEL. The Impact of Feed Preparation Acid Stoichiometry and Redox on Melt Rate for the SB3-Frit 418 Feed System. Office of Scientific and Technical Information (OSTI), 2004. http://dx.doi.org/10.2172/833413.

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Williams, Mark D., Vincent R. Vermeul, Martinus Oostrom, et al. Anoxic Plume Attenuation in a Fluctuating Water Table System: Impact of 100-D Area In Situ Redox Manipulation on Downgradient Dissolved Oxygen Concentrations. Office of Scientific and Technical Information (OSTI), 1999. http://dx.doi.org/10.2172/15002681.

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MD Williams, VR Vermeul, M Oostrom, et al. Anoxic Plume Attenuation in a Fluctuating Water Table System: Impact of 100-D Area In Situ Redox Manipulation on Downgradient Dissolved Oxygen Concentrations. Office of Scientific and Technical Information (OSTI), 1999. http://dx.doi.org/10.2172/7649.

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