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Hub, Serge. "Mecanismes d'hydrogenation des butene-1 et butyne-1 sur catalyseurs au palladium." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13325.
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SEGUINEAU, PASCALE. "Les reactions de wittig et wittig-horner en milieu protique peu basique." Nantes, 1989. http://www.theses.fr/1989NANT2014.
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La reaction de wittig-horner realisee dans des conditions douces (milieu aqueux peu basique) a l'aide de composes dicarbonyles permet d'acceder par bisaldolisation a des cyclenols alpha -fonctionnalises. Grace a cette technique douce, la reaction de wittig-horner est chimioselective et ne s'effectue que sur les sites carbonyles tres actifs (aldehydes)
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Zhang, Naiyuan. "Hydrogen Isotope Separation in Metal-Organic Frameworks." Oberlin College Honors Theses / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=oberlin1532013686771173.
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Cummins, Veronica Clare. "New and improved hydrogen isotope exchange reactions." Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/843371/.
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Compounds labelled with deuterium and tritium are widely used in the life sciences. Consequently there is always a need for improved methods - better incorporation, higher specificity, reduced reaction time etc. and in the case of tritium, less radioactive waste. This thesis is concerned with such aspects. Chapter 1 is a review of the background to tritium and current methods of labelling and analysis of hydrogen isotopes. In chapter 2 the possible use of an organometallic compound - the ruthenium dihydro complex, RuH2CO(PPh3)3, which is known to catalyse the insertion of olefins into the ortho position of aromatic ketones, is explored. Solid deuterated formates e.g. 2-naphthy methyl-d-formate and d-formanilide were prepared and these were used to make the deuterated complex, RuD2CO(PPh3)3 which was used to exchange deuterium into the ortho position of aromatic ketones. Aromatic compounds with other functionalities, however were not so amenable to labelling, aromatic amides were the only other compounds successfully labelled. The method is therefore more restrictive than was hoped. A method to prepare tritiated formates by ozonolysis of 2-[T]-5-phenyloxazole to a mixed anhydride followed by nucleophillic attack was discovered. [T]-formanilide was prepared in this way but only at low levels of radioactivity (0.1 Ci/mmol, 3.67 GBq/mmol) which prevented the tritiated complex being prepared. In chapter 3 the use of zeolites as strong acid catalysts for hydrogen isotope exchange reactions was explored. Isotope exchange was carried out on simple organic molecules using hydrogen, platinum and palladium exchanged zeolite-Y with D2O and HTO as isotope source. Some studies were also carried out using solid deuterium sources with the metal exchanged zeolites. Exchange occurred using 2-naphthgyl methyl-d-formate, tetrabutyl ammonium-d-formate and potassium-d-formate. In addition, microwave activation was used in order to reduce reaction times and improve isotopic incorporation.
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Owens, Philippa Kate. "Iridium complexes as highly active catalysts for hydrogen isotope exchange and hydrogen borrowing processes." Thesis, University of Strathclyde, 2018. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=30297.
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Over the last several decades, the organic chemistry community has become increasingly reliant upon iridium catalysis, with applications reported across a number of research areas. In recent years, the Kerr group has developed a series of iridium complexes, which were found to be excellent catalysts for hydrogen isotope exchange and olefin hydrogenation processes. The work described within this thesis centres upon the expansion of these catalysts’ reactivity in hydrogen isotope exchange, as well as the synthesis and application of a series of novel iridium complexes, designed for use in hydrogen borrowing catalysis. Chapter one focuses on the development of three efficient and selective methods for hydrogen isotope exchange. Iridium(I) catalysts previously developed within the group have been employed in the successful deuteration of N-heterocycles, which represent an important and relatively underexplored class of labelling substrates. The labelling of a large range of indole, pyrrole, and quinoline derivatives is reported, in which the regioselectivity can be controlled through careful choice of N-protecting group. Extensive practical and computational mechanistic investigations offered insight into the mechanism of indole C3 labelling, which is believed to proceed via an iridium–indoline intermediate. In chapter two, the design and synthesis of a series of novel unsymmetrical NHC ligands, functionalised with electron donating substituents, is described. The corresponding neutral iridium NHC/halide complexes were prepared, and the steric and electronic properties of the ligands were investigated using a number of techniques. These novel complexes were then tested in the catalysis of hydrogen borrowing processes. Extensive optimisation led to the development of an efficient method for the room-temperature N-alkylation of anilines. This methodology was also expanded to include the synthesis of N-heterocycles viaintramolecular C–N bond formation, albeit using more forcing conditions. Lastly, a small series of chiral NHC ligands was designed, and their corresponding iridium complexes prepared and used in a preliminary screening of asymmetric hydrogen borrowing.
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Lavigne, André. "Oxydations cupro-catalysees des amines aliphatiques : etudes mecanistiques et applications synthetiques." Paris 6, 1987. http://www.theses.fr/1987PA066470.
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Preparation de nitriles a partir d'amines primaires et d'alpha -aminoacides. Les acides amines monosubstutitues rch(nh::(2))co::(2)h donnent le nitrile rcn, alors que les acides amines disubstitues rr'c(nh::(2))co::(2)h conduisent a l'azine rr'c=n-n=cr'r. Les mecanismes proposes font intervenir le cuivre (iii), forme in situ a partir du cuivre (i) et de l'oxygene
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Nivesse, Anne-Laure. "Spéciation du tritium organiquement lié dans les matrices environnementales." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2020. http://www.theses.fr/2020IMTA0216.
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Le tritium est l’isotope radioactif de l’hydrogène et peut ainsi intégrer les molécules organiques d’un organisme vivant en suivant le cycle de l’eau et former la fraction tritium organiquement lié (TOL). L’existence de deux formes de TOL est communément admise : une fraction dite « échangeable » (TOL-E) et une fraction dite « non-échangeable » (TOL-NE). Cependant, un consensus scientifique fait à ce jour défaut pour décrire la répartition exacte de ces deux formes dans une molécule organique, ce qui engendre des controverses et un manque de clarté sur le comportement du tritium dans l’environnement. Cette étude consiste alors dans un premier temps à établir et comprendre l’implication de structures moléculaires spécifiques des biomolécules usuelles de la biomasse végétale sur la spéciation du TOL dans les matrices environnementales. Une vue d’ensemble est obtenue sur les capacités d’échange de l’atome d’hydrogène retrouvées dans un large panel de matrices environnementales et leur constituant majoritaire. Un intérêt majeur est accordé à la molécule de cellulose avec sa structure semi-cristalline et les capacités de stockage du tritium dans les sols sont explorées à travers une étude des capacités d’échange et de déprotonation des atomes d’hydrogène dans la matière riche en substances humiques. Dans un second temps, une étude comparative est proposée entre deux méthodes d’échange isotopique pour l’analyse de la forme TOL-NE et leur fiabilité est évaluée dans le cadre de la surveillance environnementale, mais également pour l’appréhension de la distribution du TOL dans les matrices environnementalesTritium is the radioactive isotope of hydrogen and can thus integrate the organic molecules of a living organism following the water cycle and form the organically bound tritium fraction (OBT). The existence of two forms of OBT is commonly accepted: an exchangeable fraction (E-OBT) and a non-exchangeable fraction (NE-OBT). However, a scientific consensus to date is lacking to describe the exact distribution of these two forms in an organic molecule, which generates controversies and a lack of clarity on the behavior of tritium in the environment. Therefore, this study consists first of all in establishing and understanding the involvement of specific molecular structures of the usual biomolecules of plant biomass on the speciation of OBT in environmental matrices. An overview is obtained on the exchange capacities of the hydrogen atom found in a large panel of environmental matrices and their major constituent. A major interest is focused on the cellulose molecule with its semi-crystalline structure and the storage capacities of tritium in soils are explored through a study of the exchange and deprotonation capacities of hydrogen atoms in matter rich in humic substances. Secondly, a comparative study is proposed between two isotopic exchange methods for the analysis of the NE-OBT fraction and their reliability is evaluated within the environmental monitoring scope, but also for the apprehension of the distribution of OBT in environmental matrices
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Reynard, Linda Marie. "The application of stable hydrogen isotope analysis to the study of ancient diet." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670134.
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Owens, Simon. "Kinetics and mechanisms of hydrogen isotope exchange over solid storage media." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687343.
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Hydrogen isotope separation systems using palladium (Pd) are currently being designed for both reactor designs with the aim of separating and purifying the reactor exhaust products which contain valuable unspent hydrogen isotopes. Hydrogen isotope exchange in Pd offers an efficient, ambient condition process that can produce pure isotopic species in a process far simpler and less costly than the current state of the art cryogenic distillation processes. The method is applicable whether separating hydrogen (protium), deuterium or tritium and any combination of these. If practical fusion devices are ever to be realised it is essential to produce an economical and efficient fuel cycle capable of separating and purifying hydrogen isotopes. Hydrogen isotope exchange in Pd is also of interest to the waste separation and purification industries, in particular those using hydrogen separation membranes which used Pd and Pd-alloy membranes. Understanding hydrogen isotope exchange, with particular regard to the formation of the intermediate (and often unwanted) hydrogen deuteride (HD), will aid significantly in future designs of hydrogen isotope separation systems. Novel hydrogen isotope exchange experiments involving hydrogen and deuterium at a number of temperatures (208 K, 293 K and 373 K) and pressures (1.3 bar – 8 bar) not yet explored are presented in this thesis. The experiments were carried out on a unique piece of laboratory apparatus provided to and further developed at the University of Bath. Alongside experimentation, a novel comprehensive multidimensional multi-physics model has been created to analyse the experimental data obtained using the new apparatus and elucidate the kinetics and mechanisms of the reactions occurring between hydrogen isotopic species and Pd during hydrogen isotope exchange based on Langmuir-Hinshelwood surface reaction mechanism. The surface reaction rates, kinetic rate constants and heat effects have been examined in detail, and in tandem, for the first time.
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Valero, Mégane. "Iridium-Catalyzed CH-Functionalization : Development and Applications of Innovative Strategies for Hydrogen Isotope Exchange on Small Molecules and Biotherapeutic Drugs for Drug Discovery." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS009.
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Le développement de nouvelles méthodes, efficaces, rapides et facile à mettre en œuvre pour le marquage avec du deutérium ou du tritium de composés organiques tels que des médicaments est indispensable dans le secteur industriel comme académique. Ces composés isotopiquement marqués sont essentiels lors des études précliniques. En effet, ces méthodes de marquages permettent d’obtenir plus rapidement les données nécessaires concernant la métabolisation et le profil de sécurité d’un candidat médicament, ce qui permet de réduire le temps investit dans cette recherche. Les méthodes classiques de marquages sont basées sur la synthèse d’un précurseur qui est ensuite marqué isotopiquement puis modifié jusqu’à l’obtention de la structure finale du candidat médicament. Ces anciennes méthodes, coûteuses en temps et en argent et génératrices d’effluents radioactifs, peuvent être évitées par fonctionnalisation sur la structure finale du composé d’intérêt, en particulier par échange d’isotopes d’hydrogène. Au cours de ces travaux de thèse, nous avons développé la première méthode de marquage catalytique à l’iridium dans des conditions douces (température ambiante) sur les motifs dérivés d’acides phenylacetiques tels que esters et amides, motifs très présents dans les structures pharmacologiques. Cette méthode permet d’introduire du deutérium ou du tritium en position ortho du groupement directeur de façon sélective. Lors d’un autre projet, nous avons mis en évidence que la position de marquage au sein d’une molécule avec plusieurs groupements directeurs peut être modulée en fonction du catalyseur d’iridium utilisé ainsi que de la température réactionnelle (de -60°C à +130°C). L’utilisation de calculs de DFT nous a permis de postuler un ordre classifiant différents groupements directeurs par rapport à leur réactivité vis-à-vis de la réaction d’échange d’isotopes d’hydrogène en situation de compétition (deux substrats et un catalyseur d’iridium). Ces données théoriques ont été confirmées par les données expérimentales. Lors d’un autre projet, le marquage sélectif au tritium d’une structure complexe tel qu’un médicament cytotoxique (maytansine DM4) a débouché sur le marquage de différentes chaînes latérales employées dans des méthodes de conjugaison d’anticorps. Ces données ont permis d’étendre cette méthodologie au marquage au deutérium d’acides aminés et de di-tri et tétra-peptide, sélectivement sur le carbone alpha d’un résidu glycine. Finalement, en collaboration avec le CEA-Saclay et le CNRS, nous avons développé les premières nanoparticules d’iridium stable à l’air et actives vis-à-vis de l’échange d’isotopes d’hydrogène sur des anilines. L’ensemble des travaux réalisés pendant cette thèse a permis le marquage au tritium de composés médicamenteux tels que le DM4, le Benalaxyl, ou encore le pharmacophore du VolixibatThe development of new efficient, fast and easy-to-handle methods to label drug compounds with deuterium or tritium in one single step is of great importance in academia and industry. These labelled compounds are for example an essential part in drug discovery and help to speed up the generation of the safety profile of a drug candidate. Classical isotope labeling mainly relies on the transformation of precursors which require multistep synthesis, a drawback which may be overcome by late-stage functionalization. We reported the first efficient catalytic protocol for ortho-selective iridium(I)-catalysed Hydrogen Isotope Exchange (HIE) reactions of pharmacologically important phenylacetic acid esters and amides with D2 or T2 under very mild reaction conditions (room temperature). We have demonstrated that by applying the optimized combination of different iridium catalysts and reaction temperatures (-60 to 130°C), different HIE reaction outcomes in selectivity and reactivity can be achieved. Together with DFT calculations, we have postulated a guideline for directing group strength of several functional groups, to predict the outcome of HIE reactions in the competition situation of complex molecules. Starting from a complex tritium labelling of the maytansine DM4 drug, the HIE reaction on a series of common linker side chains of antibody-drug-conjugates proceeded with high chemical yields, high regioselectivity and with deuterium incorporations up to 99%. The scope of the method was further extended to amino acids, di- and tripeptides, with deuterium incorporation up 95%D in the glycine moiety. Finally, in collaboration with CEA-Saclay and CNRS, air-stable and easy-to-handle iridium NHC-ligated nanoparticles were developed for the first time and used in HIE reactions of complex anilines. The usefulness of the methods developed all along the PhD was demonstrated by tritiation of DM4, Camylofine, Benalaxyl and the Volixibat pharmacophore
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Hesk, David. "Aspects of the regiospecificity of homogeneous metal catalysed hydrogen isotope exchange reactions." Thesis, University of Surrey, 1988. http://epubs.surrey.ac.uk/844314/.
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This thesis is concerned with the preparation of regiospecifically labelled compounds by homogeneous metal catalysed hydrogen isotope exchange reactions. The features of homogeneous hydrogen isotope exchange reactions are discussed in Chapter 1, along with other exchange methods; acid, base, heterogenous metal, radiation, enzymic and zeolite catalysis. In Chapter 2, homogeneous rhodium trichloride is investigated for regiospecificity of tritium labeling in a wide range of aromatic compounds. High regiospecificity of labelling ortho to carboxyl, carboxamide and methanamide groups is found, with the regiospecificity determined by 3H nmr spectroscopy. Also discussed is a study to determine whether any other Group VIII metal complexes will catalyse the ortho tritiation of benzoic acid, in addition to rhodium trichloride. The results of detritiation studies performed on benzoic acids using ruthenium acetylacetonate as catalyst as a model for rhodium trichloride are presented in Chapter 3, A possible reaction mechanism is also presented. Finally, an application of the rhodium trichloride system to the labelling of biologically useful molecules is discussed in Chapter 4. The deuteration and tritiation of a number of drugs and metabolites containing known ortho directing groups is described. In a large number of cases, the regiospecificity for ortho labelling is very high.
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Koutit, Abbès. "Reactions chaudes entre atomes de tritium et composes inorganiques (h : :(2)o, h::(2)s, nh::(3))." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13029.
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Dawson, Daniel. "Stable hydrogen isotope ratios of individual hydrocarbons in sediments and petroleum." Curtin University of Technology, Department of Applied Chemistry, 2006. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=16839.
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Early research into the stable hydrogen isotopic compositions (δD) of petroleum involved bulk deuterium/hydrogen (D/H) measurements which, while providing some useful information, had to contend with the analysis of complex mixtures of hydrocarbons, and alteration resulting from the rapid exchange of nitrogen-, oxygen- and sulphur-bound hydrogen. The use of gas chromatography-isotope ratio mass spectrometry (GC-irMS) overcomes these problems by allowing the analysis of individual compounds containing only the most isotopically conservative aliphatic carbon-bound (C-bound) hydrogen. This project investigates the geochemical utility and reliability of compound-specific δD values, with the aim to better understand and exploit this analytical capability. To demonstrate the source diagnostic potential of compound-specific δD values, normal and branched alkanes extracted from series of immature bog-head coals (torbanites) were analysed. The torbanites contain immature organic matter predominantly from a single, freshwater algal source, i.e. Botryococcus braunii (B. braunii). The δD values of n-alkanes reflect the climate regime at the time of deposition of the torbanites, and vary mainly in response to the δD values of the source meteoric waters in their depositional environments. n-Alkanes from torbanites deposited at high latitude in a glacial climate are depleted in D by up to 70% relative to those from a torbanite deposited at low latitude under a tropical climate regime. Torbanites deposited in a mid-latitude region under cool-temperate conditions contain n-alkanes with δD values falling in between those of n-alkanes from tropical and glacial torbanites.The δD values of the n-alkanes also reflect their multiple source inputs. For example, a saw-toothed profile of n-alkane δD values in Australian torbanites is attributed to a dual-source system: a predominant B. braunii input, with a minor terrestrial plant input to odd-carbon-numbered n-alkanes in the range n-C20 [subscript] to n-C29 [subscript]. The δD values of n-alkanes and isoprenoids (pristane and phytane) differ significantly in two Permian torbanites from Australia, thought to be reflective of the offset between the δD values of their precursors in extant organisms. The torbanite data indicate that a biological δD signal has been preserved for at least 260–280 million years, extending the utility of δD values for palaeoclimate studies. To elucidate the effect of sedimentary processes on the δD values of petroleum hydrocarbons, three sedimentary sequences have been studied. These comprise one from the Perth Basin (Western Australia) and two from the Vulcan Sub-basin (northern Australia) covering a wide range of maturities, i.e. 0.53–1.6% vitrinite reflectance (Ro). The δD values of n-alkanes extracted from immature-early mature sediments (marine shales/siltstones and mudstones) are consistent with that expected of marine-derived n-alkyl lipids. The hydrocarbons become enriched in D with increasing maturity. The large (ca. 115%) biologically-derived offset between the δD values of n-alkanes and acyclic isoprenoids from immature sediments gradually decreases with increasing maturity, as the isoprenoids become enriched in D more rapidly than the n-alkanes. The D-enrichment in isoprenoids correlates strongly with Ro and traditional molecular maturity parameters.
This suggests that H/D exchange during maturation occurs via a mechanism involving carbocation-like intermediates, which proceeds more rapidly with compounds containing tertiary carbon centres. Significant epimerisation of pristane and phytane coincides with their D-enrichment, suggesting that hydrogen exchange occurs at their tertiary carbons. A mechanism is proposed which can account for both H/D exchange and the epimerisation of pristane and phytane in the sedimentary environment. Pristane and phytane extracted from a post-mature sediment from the Paqualin-1 sequence are significantly enriched in D (ca. 40%) relative to the n-alkanes, indicating that D-enrichment persists at very high maturity, and is more pronounced for the regular isoprenoids than the n-alkanes. This supports the notion that H/D exchange causes the observed shift in δD values, rather than free-radical hydrogen transfer. The differences between the δD values of pristane and phytane show opposite trends in the Perth Basin and Vulcan Sub-basin sediments. In the Perth Basin, phytane is enriched in D relative to pristane, likely due to a dominant algal source. In the Vulcan Sub-basin, pristane is enriched in D relative to phytane, and thus is attributed to a lower relative input of algal organic matter. The variance of the δD values of pristane and phytane is generally consistent throughout the maturity range and provides evidence that pristane and phytane exchange hydrogen at similar rates. δD analysis of crude oils and condensates reservoired in the Perth Basin and Vulcan Sub-basin has been carried out to evaluate potential applications in oil-source correlation.
The n-alkanes from crude oils and condensates are often more enriched in D than n-alkanes extracted from their supposed source rocks, and the oils also show relatively small differences between the δD values of n-alkanes and isoprenoids. These results suggest significant H/D exchange has occurred, implying that the liquids were generated from mature source rocks. A Perth Basin crude oil (Gage Roads-1) thought to be derived from a lacustrine/terrestrial source contains hydrocarbons that are significantly depleted in D relative to Perth Basin oils derived from a marine source, attributed to variability in the isotopic composition of marine and terrestrial source waters. δD values of n-alkanes from Vulcan Sub-basin crude oils and condensates are largely consistent with their prior classification into two groups: Group A, having a marine source affinity; and Group B, having a terrigenous source affinity. Some oils and condensates are suggested to be mixtures of Group A and Group B hydrocarbons, or Group A hydrocarbons and other as yet unknown sources. An exception is a former Group A oil (Tenacious-1) containing n-alkanes that are enriched in D relative to those from other Group A oils and condensates, attributed to mixing with another source of more mature hydrocarbons. The n-alkane δD profile appears to be indicative of source and sedimentary processes. One Perth Basin crude oil (Dongara-14) contains lower-molecular-weight n-alkanes that are depleted in D relative to higher-molecular-weight n-alkanes, attributed to a mixed marine/terrestrial source.
Group A crude oils and condensates from the Vulcan Sub-basin display a ‘bowl-shaped’ profile of n-alkane δD values. An upward inflection in the n-alkane δD profile from n-C11 [subscript] to n-C15 [subscript] is suggested to represent the addition of D-enriched lower-molecular-weight n-alkanes from a more mature wet gas/condensate to an initial charge of lower maturity oil. Ultimately, this project has demonstrated that the δD values of individual petroleum hydrocarbons can be used to elucidate the nature of source organic matter and depositional environments. The preservation potential of lipid δD values is greater than previously thought, although it is clear that H/D exchange accompanying maturation can have a significant effect on the δD values of certain hydrocarbons. Thus, great care must be taken when interpreting δD values of individual hydrocarbons, particularly those derived from sediments of high thermal maturity.
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Roston, Daniel Harris. "The use of kinetic isotope effects in studies of hydrogen transfers." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/1498.
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The present dissertation seeks to deepen our understanding of hydrogen transfers and especially C-H bond activations in enzymes. Hydrogen transfers are ubiquitous in chemistry and biology and a thorough understanding of how they occur and what factors influence them will facilitate developments in biomimetic catalysis, rational drug design, and other fields. A particular difficulty with H-transfers is the importance of nuclear quantum effects to the reaction, particularly tunneling. The overall scope of the work here aims to examine how experimental kinetic isotope effects (KIEs) can be interpreted with a particular type of tunneling model, referred to as Marcus-like models, to yield a semi-quantitative picture of the physical mechanisms of H-transfers. Previous work had used this kind of model to qualitatively interpret experimental data using a combination of intuition and generalized theories. The work here examines these theories in quantitative detail, testing and calibrating our intuition in the context of several experimental systems. The first chapter of research (ch. II) focusses on the temperature dependence of primary KIEs and how these experiments can be quantitatively interpreted as a probe for certain kinds of enzyme or solvent dynamics. The subsequent chapters (ch. III-VI) focus on the use of secondary KIEs to determine the detailed structures of tunneling ready states (TRSs) and how the dynamics of H-tunneling affect those structures. These chapters focus primarily on the TRS of the enzyme alcohol dehydrogenase, but by examining an uncatalyzed analogue to that reaction (ch. VI), the work gains some insight about similarities and differences between catalyzed and uncatalyzed reactions. In summary, the work uncovers some principles of catalysis, not just the mechanism of a catalyzed reaction. The mechanism of C-H activation presented here provides an elegant solution to problems that have been vexing to accommodate within traditional models. This work constitutes some initial steps in making Marcus-like models quantitatively useful as a supplement or even replacement for traditional models of reactivity.
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Mudd, Richard J. "Hydrogenation and hydrogen isotope exchange : novel, selective catalyst and process development." Thesis, University of Strathclyde, 2016. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27335.
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The field of iridium(I)-mediated processes has expanded over the past 50 years, with new avenues of research constantly opening. To this end, the Kerr group has developed a series of cationic iridium(I) catalysts bearing a bulky NHC/phosphine ligand sphere that can effectively mediate mild hydrogen isotope exchange and olefin hydrogenation processes. Having said this, with the ever-expanding scope of NHCs and the increasing ease of access to phosphines, the possibility still exists to further improve upon these complexes with lower catalyst loadings, faster reaction times, and an improved substrate scope. To this end, this thesis details some of the work achieved throughout the last 3.5 years. Within the first chapter, progress towards more efficient olefin hydrogenation is discussed. In the first instance, highly selective hydrogenation, through the use of a directing group was targeted. Initial investigations focussed upon manipulating the counterion to the cationic iridium(I) complexes in question, and manipulating the ligand sphere through changing the nature of the phosphine and NHC. This process generated new methods for the synthesis of NHC/phosphine catalysts, and was applied to the production of a number of novel complexes. Following on from this, a highly efficient reduction process was optimised, and the selectivity therein investigated. Following on from this, the equivalent asymmetric reaction was then studied, thus entering a new field of research within the group, and therefore, requiring the development of a completely new catalyst system. This process was guided by the non-asymmetric system, and synthesis of a number of model non-chiral complexes. After thoroughly testing the newly synthesised complexes, greater understanding was gained of the requirements for a highly enantioselective reaction, and, through this, to propose a plausible selectivity model and mechanism. In chapter two, we discuss the development of NHC/phosphine catalysts in hydrogen isotope exchange, with a partiular focus on the selectivity of the exchange process. Following on from previous work in the group, this first targets the use of weakly coordinating acids as a directing group, and the impact that addition of base has upon the selectivity of the reaction. Furthermore, understanding that drug design is moving away from planar molecules, towards non-planar, sp³-rich compounds, we also investigated the possibility of exchange at positions in a molecule other than an sp² aryl ring. This was initially observed when developing the hydrogenation methods discussed in chapter one, enabling selective sp² exchange in conjugated olefins. This new, highly selective method of labelling was examined through a combined experimental and computational investigation, leading to a thorough understanding of the mechanism and factors governing reaction selectivity. Having progressed from sp²-aryl to sp²-non-aryl exchange, the logical progression was to next investigate sp³ exchange. Through a detailed study three protocols were developed, enabling exchange on a wide range of sp³ hybridised sites, in pharmaceutically relevant systems. These new processes were investigated mechanistically and computationally to ascertain the mechanism and selectivity of exchange.
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Tate, D. A. "Investigations of simple atomic systems by laser spectroscopy." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379889.
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Ritz, P. "An appraisal of the doubly labelled water method for energy expenditure measurements." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319821.
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Burke, Erin E. "Heavy atom and hydrogen kinetic isotope effect studies on recombinant, mammalian sialyltransferases." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0011586.
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Pudney, Christopher R. "Kinetic isotope effects as probes of the mechanism of enzymatic hydrogen transfer." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492045.
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Chivall, David. "Compound-specific hydrogen isotope analysis of animal fatty acids for palaeodietary reconstruction." Thesis, University of Bristol, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446151.
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Bossard, Nicolas. "Pertinence et calibration d'un nouveau marqueur paléohydrologique : le rapport isotopique de l'hydrogène mesuré sur la miliacine." Thesis, Orléans, 2013. http://www.theses.fr/2013ORLE2082/document.
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Ce travail a pour objectif de développer un nouvel indicateur quantitatif des conditions hydrologiques passées fondé sur la composition isotopique en hydrogène (δD) d’un biomarqueur sédimentaire spécifique du millet commun (Panicum miliaceum), la miliacine. L’étude de la pertinence spatio-temporelle de cet indicateur révèle que le δD miliacine de plants de millet dans un champ, bien que dispersé, suit une loi gaussienne. Le δD miliacine du sol correspond au δD miliacine des plantes cultivées l’année précédente. L’évolution interannuelle du δD miliacine est globallement parallèle à celle du δD des eaux météoriques, les différences pouvant être attribuées à des différences d’humidité. La comparaison des valeurs de δD miliacine dans des sédiments du même âge prélevés sur deux archives distinctes dans le Lac du Bourget témoigne que l’archivage de cet indicateur est intègre de manière homogène les conditions climatiques ayant régné dans le bassin versant. La culture de millet en chambre climatique démontre que, si le δD de l’eau de source est le principal facteur controlant le δD miliacine, ce dernier est très étroitement corrélé au δD de l’eau de la feuille. De légères différences de fractionnement biosynthétique net entre n-alcanes et miliacine sous deux conditions d’humidité laissent supposer que l’analyse combinée de biomarqueurs sédimentaires issus de voies synthétiques distinctes permettrait d’accéder à la fois aux variables paléoenvironnementales clé que sont le δD de l’eau de source et l’humiditéThis work aims at developing a new proxy of past hydrological conditions based on the hydrogen isotopic composition (δD) of a sedimentary biomarker that is specific for broomcorn millet (Panicum miliaceum), miliacin. Analysing the spatio-temporal relevancy of this proxy reveals that miliacin δD values of plants cultivated in the field, although dispersed, follow a Gaussian law. Soil miliacin δD values are the same as those found for plants grown the year before. Interannual variations in plant miliacin δD values roughly parallel those of precipitation δD values, slight differences being attributed to differences in relative humidity. The comparison of miliacin δD values in sediments deposited in two distinct settings at the same time in Lake le Bourget attests that this proxy homogeneously integrates climatic conditions over the whole catchment. Cultivation of millet plants in climatic chambers allowed demonstrating that, although source water δD is the principal controlling miliacin δD values, this later is closely correlated to leaf water δD. Slight differences in net biosynthetic fractionation between n-alcanes and miliacin under two relative humidity levels imply that the combined analysis of sedimentary biomarkers produced through distinct biosynthetic pathways could help discriminating between source water δD and relative humidity in paleoenvironmental studies
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Vainonen-Ahlgren, Elizaveta. "Release of hydrogen isotopes from carbon based fusion reactor materials." Helsinki : University of Helsinki, 2000. http://ethesis.helsinki.fi/julkaisut/mat/fysii/vk/vainonen-ahlgren/.
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Trentin, Valérie. "Séparation des isotopes de l'hydrogène par chromatographie en phase gazeuse /." Gif-sur-Yvette : Commissariat à l'énergie atomique, 1993. http://catalogue.bnf.fr/ark:/12148/cb355817582.
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Irvine, Stephanie. "Highly active iridium (I)complexes for catalytic hydrogen isotope exchange and selective hydrogenation." Thesis, University of Strathclyde, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.510835.
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Palazzolo, Alberto. "Development of new methods for the hydrogen isotope exchange catalyzed by metallic nanoparticles." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS276.
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Les composés marqués aux isotopes de l’hydrogène possèdent des nombreuses applications lors des phases précliniques de développement des médicaments. Par exemple, les composés deutérés sont utilisés comme étalons internes dans la quantification par LC-MS de métabolites alors que les molécules tritiées sont souvent des radiotraceurs de choix dans les études d’absorption, distribution, métabolisme et excrétion (ADME) moléculaire des candidats médicaments. Après une brève introduction, un premier chapitre discutera du développement d’une méthode douce et sélective, catalysée par des nanoparticules de ruthénium, qui permet d’effectuer le marquage en une étape de bases azotées et de médicaments dérivés. En changeant le ligand qui stabilise le nanocatalyseur, on a réalisé des échanges isotopiques compliqués tels que des tritiations en utilisant une pression sous-atmosphérique de tritium gaz et des deutérations d’oligonucleotides sensibles. Le chapitre suivant décrira la modification des catalyseurs commerciaux à base de ruthénium grâce à la coordination de carbènes N-hétérocycliques (NHCs). La modification assure une régio- et une chimiosélectivité améliorées lors de la deutération d’alcools aliphatiques. Certains des catalyseurs modifiés ont permis l’échange hydrogène/deutérium sur des molécules, particulièrement sensibles à la réduction, qui n’ont pas pu être isolées en utilisant le catalyseur commercial. Dans le dernier chapitre, la synthèse et l’évaluation de l’activité catalytique des nanoparticules à base d’iridium seront discutées. Ces nanocatalyseurs ont démontré une réactivité intéressante dans le marquage des composés complexes. Dans certains cas, les nanoparticules d’iridium ont permis l’incorporation de deutérium sur des positions inhabituelles en comparaison avec d’autres réactions d’échange isotopique déjà décritesHydrogen isotopes labelled compounds possess a broad range of application in the early pre-clinical phases of drug development process. For instance, deuterated compounds are applied as internal standard in quantitative LC-MS techniques while tritiated molecules are often the preferred radioactive tracers for the study of molecular absorption, distribution, metabolism and excretion (ADME). After a brief introduction, a first chapter will discuss the development of a mild and selective method to perform late stage labelling of variously functionalized nucleobases and drug analogues catalyzed by ruthenium nanoparticles. By changing the ligand which stabilizes the nanocatalyst, we achieved challenging isotopic exchanges such as tritiations of pharmaceuticals using subatmospheric pressure of tritium gas and deuteration of sensible oligonucleotides. The next chapter will describe the modification of commercially available ruthenium nanocatalysts via the coordination of N-Heterocyclic carbenes (NHCs). The modification granted enhanced regio and chemoselectivity for the deuteration of aliphatic alcohols. Some of the modified ruthenium catalysts allowed the hydrogen/deuterium exchange on easily reducible compounds which were not obtainable using the unmodified commercial catalyst. The final chapter will discuss the synthesis and the evaluation of the catalytic activity of iridium nanoparticles. The latter, showed an interesting reactivity for the labelling of challenging substrates. In some of the investigated compounds, IrNps were able to introduce deuterium with unusual regioselectivities compared to already described hydrogen isotope exchange reactions
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Jacobs, Madelyn M. "UNDERSTANDING EXPERIMENTALLY-INDUCED AND NATURALLY-OCCURRING δ2H AND δ13C VARIATION IN A MARINE PREDATOR, THE BROWN BOOBY." University of Akron / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1590064043329883.
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Seligman, Angela. "Oxygen and hydrogen investigation of volcanic rocks: Petrogenesis to paleoclimate." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20547.
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Knowledge of the isotopic evolution of volcanic eruptions is essential to volcanologists, geochemists, and paleoclimatologists. I isotopically evaluate the evolution of magmas from their initial formation, to eruption, and then to their alteration during the diffusion of environmental waters into volcanic glass. I focus first on the formation and evolution of large, caldera-forming eruptions from both Gorely volcano in Kamchatka, Russia and 30–40 Ma caldera forming eruptions through Oregon in the United States of America. I utilize oxygen (δ18O), hafnium (εHf), strontium (87Sr/86Sr), and neodymium (143Nd/144Nd) isotopes to document the creation of caldera-forming eruptions at these eruptive centers through the melting of surrounding crust. I also use U-Pb and 40Ar/39Ar to document the timescales of the formation of these large-volume silicic eruptions.
Following eruption, the volcanic glass in tephra and ash can slowly take in environmental water. It is thought that the hydrogen isotopic ratio (δD) of these waters can be used to determine paleoenvironments from the time that the volcanic glass was deposited. The latter portion of my dissertation focuses on the use of hydrogen isotopes of environmentally hydrated volcanic glass to determine paleoenvironments, and the calibration of the TCEA to analyze oxygen isotopes of hydrated volcanic glass. I first focus on the rate of diffusion of water at ambient temperature to better understand the time frame necessary to hydrate volcanic glass for use as a paleoenvironmental indicator. I also document the hydrogen isotopic ratios that result from the diffusion of water into volcanic glass, which is documented as a decrease in δD with an increase in secondary hydration in all regions worldwide except equatorial. Finally, I focus on the earliest stages of diffusion of water into volcanic glass by analyzing tephra deposits that were collected within days of the 1980 eruptions of Mount St. Helens as well as tephra deposits recently collected in 2015 to identify changes in water concentration and hydrogen isotopic ratios over an ~35 year period.
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Hodille, Etienne. "Etude de l'implantation du deutérium dans les composés face au au plasma constituants du tokamak ITER." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4065.
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Lors de l’opération d’ITER, des flux importants d’isotopes d’hydrogène (HI) constituant le fuel interagissent avec les composants face au plasma (CFP) de la machine. Dans le cas du Tungstène (W) composant le divertor qui est la zone la plus exposée aux interactions plasma paroi, le flux incident est implanté et diffuse ensuite dans le corps du matériau entrainant un piégeage du fuel. Pour des raisons de sureté, l’inventaire de Tritium retenu dans les parois d’ITER est limité. De plus, le dégazage du fuel depuis les parois vers le plasma, lors des opérations plasma peut avoir un impact sur le contrôle global du plasma. Le but de cette thèse est d’abord de déterminer les paramètres de piégeages du fuel dans le W (énergies/températures de dépiégeage, concentrations de pièges) grâce à la modélisation de résultats expérimentaux. Ces simulations de résultats expérimentaux montrent que l’implantation d’HIs dans le W peut induire, sous certaines conditions, la formation de lacunes contenant des impuretés. En plus de ce piège induit par l’implantation d’ions, 2 pièges intrinsèques sont présents dans le W. Ces 3 pièges retiennent les HIs jusqu’à 700 K. Enfin, il est montré que le W endommagé par des ions lourds ou des neutrons contient des dislocations, des boucles de dislocations et des cavités retenant les HIs jusqu’à 1000 K.Après avoir déterminé ces paramètres de piégeages des HIs dans le W, la rétention des HIs durant l’opération d’ITER est estimée. Lors de cette opération, la température des CFP W atteint environ 1000 K. Les simulations montrent donc que la rétention dans les CFPs non endommagé est bien plus faible que dans le cas d’un CFP endommagéDuring ITER operation, important flux of Hydrogen Isotopes (HIs) constituting the fuel interact with the plasma facing components (PFC) of the machine. In the case of tungsten (W) making the divertor which is the most exposed area to the plasma wall interaction, the incident flux can be implanted and diffuse inside the bulk material inducing a trapping of the fuel. To safety issue, the tritium inventory retained in ITER’s PFC is limited. In addition, the outgassing of the fuel during plasma operation can impact the edge plasma control.The aim of this PhD project is first to determined relevant trapping parameters of the fuel in W (detrapping energies/temperatures and trap concentrations) by modelling experimental results. The simulations of experimental results shows that under specific condition, the HI implantation can induce the formation of mono-vacancies containing impurities. In addition to this induced trap, 2 intrinsic traps are present in W. This 3 traps retain HIs up to 700 K. Finally, it has been shown that the damaged W by heavy ions or neutrons contains dislocations, dislocation loops and cavities that can trap HIs up to 1000 K.After determining the fuel retention properties of W, the HIs retention during ITER operation is estimated. During this operation, the PFC temperature reaches around 1000 K so the simulations show that the damaged W retains much more HIs than the undamaged W
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Motz, John Edward. "Oxygen and hydrogen isotopes in fossil insect chitin as paleoenvironmental indicators." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ51214.pdf.
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Wulff, Philip. "Principles of hydrogen catalysis in the presence of oxygen by a [NiFe] hydrogenase from E. coli." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:9e434467-d50b-484a-a17e-ef3091636269.
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[NiFe] hydrogenases are metalloenzymes that act as highly efficient molecular electrocatalysts for the interconversion of protons and molecular hydrogen. Unlike any other known molecular electrocatalyst, the members of a subgroup of respiratory membrane-bound [NiFe] hydrogenases are able to maintain H2 catalysis in the sustained presence of O2. This O2-tolerance depends on the ability to respond to oxidative inactivation by O2 by exclusively forming rapidly reactivated active site states, thus implying a catalytic cycle in which O2 acts as a competing substrate to H2. Using isotope ratio mass spectrometry it is proven that the O2-tolerant Escherichia coli Hydrogenase 1 responds to O2 attack by acting as a four-electron oxidoreductase, catalysing the reaction 2 H2 + O2 → 2 H2O, equivalent to hydrogen combustion. Special features of the enzyme’s electron relay system enable delivery of the required electrons. A small fraction of the H2O produced arises from side reactions proceeding via reactive oxygen species, an unavoidable consequence of the presence of low-potential relay centres that release electrons from H2 oxidation. While the ability to fully reduce O2 to harmless H2O at the active site to generate the rapidly reactivated state Ni-B, determines if a hydrogenase is O2-tolerant, the ratio of oxidative inactivation to reductive reactivation rates determines how tolerant the enzyme is. It is shown by protein film electrochemistry that the (αβ)2 dimeric assembly of Hyd-1 plays an important role in O2-tolerance by aiding reactivation of one catalytic unit through electron transfer from the other. The teamwork between two redundant partners implicates a new role for dimerisation and represents a new example of cooperativity in biology. Finally, the non-natural amino acid p-azido-L-phenylalanine was synthesised and incorporated into Hyd-1, testing the possibility of introducing labels at specific sites.
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Ahmed, Shakib. "Stable isotopic study of groundwater arsenic contaminated plume at Shepley's Hill Landfill." Thesis, Boston College, 2014. http://hdl.handle.net/2345/3876.
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Thesis advisor: Rudolph HonIn the northeast United States, arsenic (As) contamination in groundwater is frequently associated with historical landfill leachate plumes. Based on the history of Shepley's Hill Landfill (SHL) in Devens, MA, solid waste disposal activities spanned nearly a century of landfilling with little or no documentation of when or what waste material was disposed. Past geochemical investigations proved the presence of high levels of As in groundwaters within and around the SHL region. A total of 114 samples were collected from the SHL region and analyzed for their hydrogeochemistry and isotopic signature. Since the isotopic ratios of äD and ä18O can potentially be influenced by the mobilization process of As, this study attempts to identify any correlations between the stable isotopic ratios and the hydrogeochemistry of SHL waters. The results of the groundwater hydrogeochemical analysis show multiple relationships between metal concentrations and As concentration levels, typical of groundwater undergoing redox reactions. The result of the stable isotope analysis show significant fractionation of stable isotope ratios away from the meteoric water line. However, the role of strong redox gradients and various redox ladder reactions involving water did not produce a significant correlation with the isotopic fractionations present within different zones of the landfill. In most cases, the fractionations stand independent of the increase/decrease in As concentration and can be attributed to either unrelated chemical reactions within groundwater or evaporation
Thesis (MS) — Boston College, 2014
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Earth and Environmental Sciences
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Fagan, Roxane. "Oxygen- and hydrogen-isotope study of hydroxyl-group behavior in standard smectite and kaolinite." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ58209.pdf.
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Zhang, Linda [Verfasser], and Guido [Akademischer Betreuer] Schmitz. "Experimental investigation on hydrogen isotope separation in nanoporous materials / Linda Zhang ; Betreuer: Guido Schmitz." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2020. http://d-nb.info/1222515466/34.
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Abraham, Elizabeth C. "Analysis of Temporal Range Change in Neotropical Passerine Migrants Using Stable Hydrogen Isotope Techniques." Youngstown State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1442928910.
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Yidan, Shen. "Solvent Isotope Effect and Hydrogen Bond Effect on The Self-assembly Process of Macroions." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1522256710854143.
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Giraudet, Maxence. "Coadsorption de l’hydrogène et du deutérium sur zéolithes à températures cryogéniques : effet des propriétés de l’adsorbant sur la sélectivité." Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCK007.
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L’adsorption de l’hydrogène et du deutérium purs ou en mélanges a été étudiée sur une série de zéolithes en faisant varier différents paramètres (taille et géométrie des pores, rapport Si/Al, nature du cation compensateur de charge).Les sélectivités d’adsorption ont été déterminées dans un large domaine de pression (0,1 – 1000 hPa) et de température (45 – 100 K) à l’aide une technique originale basée sur le couplage de la manométrie et de la spectrométrie de masse conçue et mise au point au laboratoire. En accord avec les données de la littérature, pour tous les matériaux et toutes les conditions expérimentales étudiées, le processus de coadsorption est toujours en faveur du deutérium. En revanche, la sélectivité varie en fonction du taux de remplissage, des propriétés des matériaux et de la température. La cinétique de coadsorption joue un rôle très important sur la sélectivité d’adsorption et ce tout particulièrement dans le domaine de fort remplissage.Ces travaux ont permis d’identifier les paramètres de l’adsorbant et les conditions opératoires qui permettront le développement d’un procédé de séparation efficace des isotopes de l’hydrogène par adsorption sélectiveThe adsorption of hydrogen and deuterium (single gases and mixtures) was studied on a series of zeolites with varied parameters (Si/Al ratio, nature of the charge-compensating cation, pore geometry and diameter of pore aperture). Thermodynamic adsorption selectivities towards deuterium with respect to hydrogen were measured in a large pressure range (0.1 – 1000 hPa) and for several temperatures (45 – 100 K). The adsorption selectivity was assessed using direct coadsorption measurements performed by manometry coupled with mass spectrometry. For all studied zeolites and experimental conditions, the coadsorption process is selective towards deuterium, in agreement with the literature. However, the adsorption selectivity depends on the loading, the sorbent’s properties and the temperature. We have found that the coadsorption kinetics strongly influences the adsorption selectivity, especially at high loading. This work gives the guidelines for the choice of the formulation of materials and the optimal operating conditions for having an efficient separation of hydrogen isotopes using zeolite-based adsorbents
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Juillet, Clara. "Mécanismes et cinétiques de perméation de l’hydrogène dans les alliages de zirconium oxydés Kinetics of hydrogen desorption from Zircaloy-4: Experimental and modelling Effect of a pre-oxidation on the hydrogen desorption from Zircaloy-4 Effect of the precipitates on the hydrogen desorption kinetics from zirconium-niobium alloys Kinetics of deuterium permeation through Zircaloy-4 in the 623 – 773 K temperature range." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST060.
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Au cœur des réacteurs à eau pressurisée, les pastilles de combustible sont isolées du circuit primaire par des gaines en alliages de zirconium. En conditions nominales de fonctionnement, l’interaction entre ces gaines et le milieu primaire entraîne la formation d’un oxyde et l’absorption d’hydrogène par l’alliage. La désorption de l’hydrogène lors du transport de combustible usé et le relâchement du tritium issu de la réaction de fission au sein des pastilles de combustible en réacteur sont des problématiques importantes pour la sûreté. Il est impératif d’estimer la quantité de tritium susceptible d’être relâchée des assemblages dans le milieu primaire ainsi que les quantités d’hydrogène désorbé sous vide ou gaz neutre pendant le transport. Au-delà de cet aspect quantitatif, comprendre le mécanisme de perméation de l’hydrogène et de ses isotopes dans les gaines en alliage de zirconium est nécessaire si l’on veut maîtriser les rejets et émissions de ces produits et in fine la sûreté. Le processus de perméation du tritium à travers une gaine oxydée peut se décomposer en 9 étapes : 1. Adsorption de tritium à la surface de l’oxyde formé sur la face interne ;2. Passage des sites de surface aux sites de subsurface en tant qu’espèce absorbée ;3. Diffusion de tritium dans l’oxyde jusqu’à l’interface oxyde/métal ;4. Intégration de tritium dans le métal ;5. Diffusion de tritium dans le métal ;6. Intégration de tritium dans l’oxyde ;7. Diffusion de tritium dans l’oxyde jusqu’à la subsurface ;8. Passage des sites de subsurface aux sites de surface en tant qu’espèce adsorbée ;9. Recombinaison et désorption.Les objectifs de l’étude sont de déterminer l’étape cinétiquement limitante du processus de perméation de l’hydrogène dans les alliages Zircaloy-4 et M5Framatome, de quantifier les constantes cinétiques associées et de développer un modèle numérique pouvant prédire les flux de désorption de l’hydrogène. De par la complexité du processus de perméation du tritium à travers une gaine de combustible oxydé, un système simplifié sans couche d’oxyde a initialement été étudié. Le processus de désorption de l’hydrogène a été investigué par thermodésorption en rampe de température ainsi qu’en isotherme, et modélisé par éléments finis avec le code Cast3M. Les constantes cinétiques ont été évaluées et optimisées en couplant le modèle Cast3M et l’outil d’optimisation de la plateforme URANIE. Le flux de désorption s’est avéré être proportionnel au carré de la concentration en hydrogène avec une constante de désorption dont l’énergie d’activation est égale à 290 ± 10 kJ/mol. Pour le M5Framatome, les conclusions et résultats sont quasi-identiques au cas précédent, à ceci près que la désorption de l’hydrogène piégé par les précipités riches en niobium lors de la fabrication semble être assujettie à leur dissolution. Le développement d’un banc de perméation de deutérium gazeux fonctionnant entre 623 et 773 K a permis de mettre en évidence que la cinétique du processus de perméation est également limitée par l’étape de recombinaison de surface pour le Zircaloy-4. Ces essais de perméation ont révélé le rôle important de l’état de surface, puisque l’application par le dispositif d’une contrainte et d’une déformation induit une augmentation du flux de désorption. Des essais d’oxydation ont ensuite été effectués sous diverses atmosphères. Lors d’essai de désorption en rampe de température, la dissolution de l’oxyde dans le métal semble piloter la cinétique de désorption de l’hydrogène. Le développement de modèles numériques et analytiques a permis de démontrer dans le cas d’une dissolution négligeable de la zircone, une cinétique de désorption contrôlée par un régime mixte de diffusion de l’hydrogène dans l’oxyde et de recombinaison surfacique et de quantifier la constante de désorption et le coefficient de diffusion dans la zircone.A partir des résultats de la thèse, une estimation de la quantité de tritium relâché sous vide a pu être établieAt the heart of Pressurized Water Reactors, the uranium oxide fuel leads isolated from the primary circuit by zirconium alloys cladding. Under normal operating conditions, the interaction between these claddings and the primary water results in the formation of an oxide scale and the hydrogen absorption in the alloy. During operation in a reactor and during the transport of used nuclear fuels, the desorption of this hydrogen and the tritium resulting from the ternary fission from the fuel rods is a safety concern. It is imperative to estimate the amount of tritium prone to be released from the fuel assemblies into the primary water and the quantities of hydrogen desorbed under vacuum or neutral gas for the transport issue. Beyond this quantitative aspect, understanding the permeation mechanism of hydrogen and its isotopes in zirconium alloy claddings is necessary if we want to control releases and more generally safety. The tritium permeation through the oxidized fuel cladding can be decomposed into 9 steps: 1. Tritium adsorption on the oxide formed on the inner face; 2. Passing from surface sites to subsurface sites as absorbed species; 3. Tritium diffusion through the oxide towards the oxide/metal interface; 4. Integration into the metal; 5.Tritium diffusion through the metal; 6. Integration into the oxide lattice; 7. Tritium diffusion through the oxide towards the subsurface; 8. Passing from subsurface sites to surface sites as adsorbed species; 9. Recombination and desorption.This study is aimed at identifying, among these 9 steps, the kinetically limiting step of the hydrogen permeation process in Zircaloy-4 and M5Framatome alloys, quantifying the associated kinetic constants and developing a numerical model that can predict hydrogen desorption fluxes. Due to the complexity of the tritium permeation process through an oxidized fuel cladding, a simplified system without an oxide layer was initially studied. A study on the hydrogen desorption process was carried out by thermodesorption in temperature ramp and in isotherm, in order to model by finite elements with the Cast3M tool the desorption kinetics and to quantify the associated kinetic constant by coupling with the URANIE optimization tool. The desorption flux was found to be proportional to the square of the hydrogen concentration with a desorption constant whose activation energy is equal to 290 ± 10 kJ/mol. A similar study on M5Framatome revealed during a temperature ramp that hydrogen desorption from niobium-rich precipitates appears to be controlled by their dissolution. The development of a deuterium permeation device operating between 623 and 773 K has demonstrated that the rate-limiting step of the hydrogen permeation is the surface recombination for Zircaloy-4. These permeation experiments have highlighted the important role of surface state, because the application by the device of stress and strain induces a desorption flux increase. Oxidation tests were then carried out under various atmospheres. During a temperature ramp desorption experiment, the oxide dissolution into the metal appears to control the kinetics of hydrogen desorption. The development of numerical and analytical models made it possible to demonstrate in the case of a negligible zirconia dissolution, a desorption kinetics limited by a mixed regime of hydrogen diffusion through the oxide and surface recombination and to quantify the desorption constant and diffusion coefficient in zirconia. From the thesis results, an estimate of the tritium released quantity under vacuum was established
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Burke, Roger Allen Jr. "Stable Hydrogen and Carbon Isotopic Compositions of Biogenic Methanes." Scholar Commons, 1985. https://scholarcommons.usf.edu/etd/7658.
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Stable hydrogen and carbon isotopic compositions of biogenic methanes collected from the sediments of several deep-sea, nearshore marine-estuarine, and freshwater environments were determined. The isotopic compositions of methane samples from eight different DSDP Sites (mean σD-CH4 = -1850>/∞, std. dev. = 70>/∞, n = 75; mean σ13C-CH4 = -71.30/∞, std. dev. = 6.30/∞, n = 44) are generally typical of methane formed via C02 reduction in deep-sea sediments.
Methane collected from several freshwater environments was D-depleted (mean σD-CH4 = -3000>/∞ , std. dev. = 260/∞, n = 20) and 13C-enriched (mean σ13C-CH4 = -60.10/∞, std. dev. = 6.10/∞, n = 20) compared to the deep-sea methane. Normally, acetate dissimilation is thought to account for about 60 to 70% of the total methane production in freshwater sediments.
Nearshore marine-estuarine methanes appear to be isotopically intermediate (mean σD-CH4 = -2580>/∞ , std. dev. = 230/∞, n = 46; σ13C-CH4 = -61.80/∞, std. dev. = 3.10/∞, n = 46) between deep-sea and freshwater methanes. Variation in the relative importance of the two main methanogenic pathways, acetate dissimilation and C02 reduction, is probably the single most important factor responsible for the differences in methane isotopic compositions among these three different types of environments. Other factors that probably contribute to the methane isotopic differences are temperature, sedimentation rate, organic matter type and amount, concentration of alternate electron acceptors, rate of methane formation and possibly postgenerative isotopic equilibration.
Shallow aquatic sediments are thought to be an important source of methane to the atmosphere; the methane produced in these systems, including the ones sampled in this study, is generally substantially more 13C-depleted than expected based on the σ13C of atmospheric methane and the isotopic fractionation associated with the atmospheric sink process. Too few oD data are available to allow evaluation of the role of shallow aquatic sediments in determining atmospheric σD-CH4.
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CHO, HYUCK. "COINCIDENCE DETECTION OF PROTONS AND METASTABLE HYDROGEN ATOMS FROM DISSOCIATIVE IONIZATION OF MOLECULAR HYDROGEN BY ELECTRON IMPACT (TIME-OF-FLIGHT)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188027.
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A coincidence has been observed between H(2S) and H⁺ fragments resulting from the bombardment of H₂ with 100 eV electrons. A significant source of this coincidence is believed to be the 2sσ(g) state of H₂⁺. The time-of-flight (TOF) distribution of H(2S) fragments from the 2sσ(g) state was measured and converted to the kinetic energy distribution from which the potential energy of the 2sσ(g) state in the Franck-Condon region was constructed. The result is in good agreement with a published calculation.
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CASTLE, KENNETH ROBERT. "ABSOLUTE RADIOMETRIC CALIBRATION OF A SPECTROPOLARIMETER." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188026.
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Two identical instruments have been developed for use in the field to make radiometric measurements. They have been described as spectropolarimeters because of their ability to make polarization measurements in narrow spectral passbands. They have been used as part of a NASA sponsored project to monitor the spectral and temporal response of the thematic mapper satellites. These satellites allow many natural and man-tended resources to be monitored over years of time, thus allowing their use to be planned for in the future. The dissertation discusses the design, fabrication, testing and absolute radiometric calibration of these spectropolarimeter instruments. The outstanding feature of these instruments are that they have been calibrated absolutely, for radiance measurements, to an accuracy of 2% - 3%, in the range of 400 nm to 1040 nm over selected spectral passbands. Previously, field measurements were considered good if they had an absolute accuracy of 10%, implying that the present accuracies are advancing the state-of-the-art for field instrument calibrations. These improved accuracies are the result of using two recently developed calibration standards, both of which use detector based methods. These standards are the Electrically Calibrated Pyroelectric Radiometer (ECPR), and the QED-100 quad detector. The end of the dissertation discusses the attempts made to verify that the accuracies claimed are indeed valid, and it is the author's belief that these accuracies have been verified completely.
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Englebrecht, Amy C. (Amy Cathryn) 1978. "Determination of sediment provenance at drift sites using hydrogen isotopes in lipids." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/58443.
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Thesis (S.M.)--Joint Program in Chemical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2004.Includes bibliographical references.
Paleoclimate records with sufficient length and temporal resolution to study the occurrence and causal mechanisms of abrupt climate change are exceedingly rare. Rapidly deposited ocean sediments provide the best archive for studying these events through geologic time, but such sites in the open ocean are limited to sediment drift deposits such as the Bermuda Rise in the northwest Atlantic. Using multiple climate proxies in a single core is becoming more common in high-resolution paleoclimate investigations, but a major potential concern for this approach arises from the possibility that the fine fraction of sediment (< 63 [micro]m), and the climate proxies within it, may represent conditions far from the deposition site. We hypothesize that hydrogen isotope ratios of alkenones, a class of lipids from phytoplankton, may provide insight into the source of fine fraction sediment. Because of their restricted sources, broad geographic distribution, and excellent preservation properties, alkenones are of particular interest in the emerging field of' compound-specific hydrogen isotopic analysis, and the sedimentary abundances, extents of unsaturations, and isotopic compositions of alkenones provide quantitative and near-continuous records. We isolated alkenones from cultured unicellular algae (haptophyte Emiliania huxleyi), surface ocean particulate material, and open ocean sediments to determine the extent and variability of hydrogen isotopic fractionation in the di-, tri-, and tetraunsaturated C₃₇ compounds. We then compared the [delta]D of the alkenones in surface sediments between the Bermuda Rise and the Scotian Margin above which a large ([approximately]20%) [delta]D gradient exists. We determined the fractionation between alkenones
(cont.) from suspended particulate samples and the water in which the phytoplanton lived, and examined the variability of alkenone 6D during key climate transitions at the Bermuda Rise.
by Amy C. Englebrecht.
S.M.
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Halenyane, Keolebogile. "Investigating recharge rates in Table Mountain springs using oxygen and hydrogen isotopes." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/27834.
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This thesis investigates the monthly variation in hydrogen and oxygen isotope composition of four springs at the foot of Table Mountain, and by comparing this variation with that of local rainfall, estimates are made of their recharge rate. The oxygen, hydrogen, and EC data for Main spring, De Waal spring, Albion spring, and Newlands springs for the years 2013 to 2016 are presented. The oxygen and hydrogen isotope composition of monthly rainfall collected nearby at the University of Cape Town (UCT) over the same period are also presented. The rainfall data ranges in δD and δ¹⁸O values from -57 to +18 ‰ and -8.1 to +3.19 ‰, respectively, with most δD and δ¹⁸O values between -60 and -20‰, and -10 and +4‰. The data shows seasonal pattern, with lower δD and δ¹⁸O values in winter and higher in summer. The UCT monthly rainfall samples define a meteoric water line whose equation is δD = 6.03*δ¹⁸O + 7.07, which is similar to previous versions of the equation from the 1995 to 2008 data. The range of recorded EC values for the springs are distinct, the average EC values for each of the spring is; Albion spring 207 μS/cm, Newlands spring 128 μS/cm, Main spring 171 μS/cm and De Waal 166 μS/cm. The isotope compositions of the springs are also well grouped, with each spring plotting in a distinct field on a δD and δ¹⁸O plot. Main spring has the lowest δD and δ¹⁸O values and De Waal spring has the highest δD and δ¹⁸O values. The springs' average δD and δ¹⁸O values for the three years sampled are -7.7 and -2.74‰ (Albion), -6.48 and -2.46‰ (De Waal), -11.52 and -3.48‰ (Main) and -8.49 and -3.14‰ (Newlands). The d-excess of the rainfall range between -11.56 and +33.12 and for the springs is between 0.17 and 27.97. The summer months (low rainfall) have lower d-excess values than the winter months (higher rainfall). There is a positive relationship between the rainfall d-excess, springs d-excess and the rainfall amount, as the amount of rainfall increases the d-excess values of both the rainfall and springs increase. The change in the springs d-excess values clearly mimics that of the rainfall. The similar pattern changes of the d-excess values and δD and δ¹⁸O of the rainfall is reflected in the spring water, suggesting that recharge is occurring rather rapidly and from the d-excess values, the recovery seem to occur for some springs from month to month. De Waal spring mimics the rainfall d-excess very closely, the changes are almost at the same time, and therefore the De Waal spring is recharged the fastest, recovery occurs from month to month. Newlands d-excess does not change at the same time at the rainfall's d-excess, Newlands is the slowest spring to recover, with recharge occurring at least within three months. Main spring and Albion spring fall in between the fastest and slowest recovering spring. The springs are recharged at different rates but with the general average of recharge rate of one to three months of recovery. The difference in δD and δ¹⁸O values between the springs is best explained in terms of difference in average altitude of the potential recharge areas. Average altitude of potential recharge estimated from the topographic map is as follows: Albion spring 286 m, Newlands spring 359 m, Main Spring 518 m and for the De Waal spring 335 m. There is a strong negative correlation between δD and average altitude (r = -0.90) and for δ¹⁸O and average altitude (r = -0.82). In 2012 the annual weighted mean δ¹⁸O value of rainfall on top of Table Mountain was -4.0 ‰, therefore De Waal spring (δ¹⁸O -2.46 ‰) has a small component of mountain rainfall compared to Main spring (δ¹⁸O -3.48 ‰), with Albion spring and Newlands spring in between.
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Oh, Hyunchul [Verfasser], and Elias [Akademischer Betreuer] Klemm. "Nanoporous materials for hydrogen storage and H2/D2 isotope separation / Hyunchul Oh. Betreuer: Elias Klemm." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2014. http://d-nb.info/1053959869/34.
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O'Leary, Julie Ann Asimow Paul David. "Hydrogen isotope geochemistry of the mantle : constraints from back arc basin basalts and mantle xenoliths /." Diss., Pasadena, Calif. : California Institute of Technology, 2007. http://resolver.caltech.edu/CaltechETD:etd-12182006-072449.
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Reid, Marc. "On the design and further applications of iridium (I) complexes in hydrogen isotope exchange processes." Thesis, University of Strathclyde, 2015. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=26040.
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A new synthetic procedure for isolation of three established Kerr group catalysts has been successfully developed. The final yield of these catalysts has now been improved beyond those published in the literature, and has allowed for the commercialisation of such catalysts for the first time. The synthesis of a series of iridium(I) complexes of the type [(COD)Ir(IMes)(PPh₃)]X (X = BF₄, OTf, and BArF) has been established. Application of these species in hydrogen isotope exchange (HIE) processes revealed more efficient catalysis and a wider solvent scope when X = BArF. Additionally, these findings have allowed for the development of a novel method for ortho-HIE in unprotected tetrazoles under basic conditions, revealing a rare account of N-H tetrazole C-H activation and a new mode of reactivity for Kerr group HIE catalysts. Towards predictive catalyst design, a combined experimental and theoretical model has been developed to describe the impact of ligand combinations on catalyst performance. Experimentally, this has resulted in a further broad range of novel NHC/phosphine iridium carbonyl complexes, as well as a catalyst 'quick screen' method based on in-situ formation of Ir dihydride complexes. Computationally, novel parameters have been assessed, culminating in a combined ligand map derived from Principal Component Analysis (PCA) of 140 DFT-optimised iridium complexes. Ligand mapping methods have been employed to assess the use of natural product Lepidiline A as a NHC ligand precursor in novel HIE catalysts, revealing the almost purely electronic influence of 4,5-dimethyl substitution on the imidaz-2-ylidene ring. The PCA model has also highlighted complexes of the type [(COD)Ir(NHC)Cl] to be promising in delivering orthogonal reactivity to the now traditional NHC/phosphine pairing. This analysis has led to the realisation of the first regio- and chemoselective catalytic labelling methods for primary sulfonamides and aldehydes. Finally, a novel, one-parameter approach has been developed to describe chelating and monodentate ligand spheres on the same comparable and quantifiable footing. Chelating NHC/phosphine-ligated iridium catalysts have been designed, synthesised, and successfully applied to ortho-labelling of previously inaccessible sulfones, secondary sulfonamides, and bulky tertiary amides.
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Taïeb, Raouf. "Les isotopes de l'hydrogène, du carbone et de l'oxygène dans les sédiments argileux et les eaux de formation." Vandoeuvre-les-Nancy, INPL, 1990. http://www.theses.fr/1990INPL064N.
Full textAbstract:
Ce mémoire présente quelques exemples d'application de la géochimie des isotopes stables à l'étude des bassins sédimentaires : 1) la composition chimique et isotopique (H, O, Sr) des eaux de formation du delta de la Mahakam (Indonésie) et la composition isotopique des minéraux carbonatées (C, O) de l'un des champs étudiés (Handil) sont interprétés comme le résultat d'une importante contribution d'eaux météoriques avec un très faible taux de mélange avec l'eau de mer. Ces eaux peuvent s'être mises en place à des âges différents ou à partir de zones de recharge différentes. Leur présence jusqu'a 3000 m de profondeur implique un important lessivage des hydrocarbures ; 2) un protocole expérimental a été élaboré pour mesurer la composition isotopique de l'hydrogène et du carbone des sédiments argileux riches en matière organique et de déterminer par bilan de masse, la composition isotopique de la matière organique associée ; 3) une nouvelle équation de fractionnement de l'hydrogène entre la montmorillonite de l'eau est proposée. La droite des kaolinites de Savin et Epstein (1970) est reconsidérée comme la droite des kaolinites et montmorillonites continentales (KML1). Une nouvelle droite (KML2) est proposée pour tenir compte de la variation de la composition isotopique des eaux météoriques en fonction des températures moyennes annuelles de l'air; 4) une trentaine de mesures isotopiques de l'oxygène, faites sur des roches totales argileuses donnent une variation entre 15 et 20 %. Les carbonates associés sont marins ou dia génétiques et ne montrent pas d'évidence pour un échange isotopique de l'oxygène avec les minéraux silicates. Une approche combinée minéralogique et isotopique est proposée pour déterminer si les sources d'apport détritique des formations argileuses sont les mêmes pour une séquence donnée et pour mesurer le degré d'échange isotopique entre le quartz et les minéraux argileux
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Clog, Matthieu. "Concentration et composition isotopique en hydrogène du manteau terrestre." Paris 7, 2010. http://www.theses.fr/2010PA077209.
Full textAbstract:
Contraindre la concentration et la composition isotopique de l'hydrogène dans le manteau terrestre apporte des informations cruciales sur le cycle global de l'eau et la nature des hétérogénéités mantelliques. Dans ce but, les bordures vitreuses des basaltes sont les échantillons les plus adaptés Lors de cette étude, 170 échantillons provenant de 4 rides océaniques et 2 points chauds ont été analysés pour leurs concentrations en eau et leur δ D. Au cours de ce travail, un biais analytique lié à l'utilisation de creusets en platine pour extraire le éléments volatils a été mis en évidence. L'utilisation de tubes en silice a donc été préférée. Les δD re-mesurés sur des échantillons précédemment analysés avec des creusets en platine sont en moyenne 15%o plus élevés. Le δ D et le rapport H2O/Ce présentent des hétérogénéités régionales et locales et constituent de traceurs de source. La source des basaltes de ride contient 175+/-70 ppm d'eau, et pour un S8\deltaSD de -61+/-6%o. Les MORB de l'océan Atlantique sont plus riches en eau (~250ppm in thé source) et en D ( δ D—57%o) que ceux de la dorsale Sud-Est Indienne (140 ppm et -63%o en moyenne), illustrant des processus de mélange différents également vus à travers les rapports Pb/Ce. L'étude de la dorsale Sud-Ouest Indienne a montré que δ D et H2O/Ce sont des traceurs du métasomatisme. Les concentrations en eau dans les sources des E-MORB et des OIB sont plu élevées et plus variables (entre 250 et 700 ppm). Les sources enrichies en eau et en élément incompatibles ont des δ D qui couvrent une gamme aussi large que celle des N-MORB (allant d -70 à -40%o). La confrontation avec les compositions isotopiques du néon et de Pb, Sr et Nd montre que le réservoir contenant des gaz rares primitifs est vraisemblablement pauvre en eau, et donc distinct du FOZO. Par conséquent, il est possible de recycler efficacement de l'eau sans en changer la composition isotopique en hydrogène dans certaines zones de subductionConstraining the concentration and isotopic composition of hydrogen in Earth's mantle brings crucial insights on the global water cycle and the nature of mantle heterogeneities. For this purpose, glassy rims of basalts are the best samples. In this study, 170 samples from 4 oceanic ridges and 2 hotspots were analysed for water content and ô D. During this work, we showed that using platinum crucibles to extract the volatiles was the cause of an analytical bias in earlier data. The use of silicate tubes was thus prefered. δ D re-measured on samples previously analyzed using platinum crucibles are, on average, 15%o higher. The δ D and the H2O/Ce ratio are hétérogeneous, both between areas and locally, and caracterize the sources. The source of N-MORB contains 175+/-70 ppm of water and has a δ D of -61+/-6%o. MORB from the Altantic ocean are richer in water (-250 ppm in the source) and D ( δ D—57%o), than those from thé South-East Indian (H2O~140 ppm and δ DS\simS-63%o), illustrating different mixing processes, also seen through the Pb/Ce ratios. The study of the MORB from the South-West Indian ridge showed that δ D and H2O/Ce are sensitive to metasomatism. The concentrations of water in E-MORB and OIB sources are higher and more variable (from 250 to 700 ppm). The ô D of water- and incompatible elements-enriched sources range from -70 to -40%o, showing as much variations as depleted sources. Confrontation with the isotopic compositions of Ne, Pb, Sr and Nd shows that the resevoir containing the primitive rare gases cannot be water-rich, and is thus different from the FOZO. Therefore, efficient recycling of water with no modification of its isotopic composition in hydrogen at subdcution zone can occur at some subduction zones
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Babler, Allison L. "Allochthony of detritivorous fish in Ohio reservoirs, as determined using stable hydrogen isotopes." Oxford, Ohio : Miami University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1250198397.
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Takagi, Ikuji. "Basic Study on Permeation and Inventory of Hydrogen Isotopes in Plasma-Facing Metals." Kyoto University, 1994. http://hdl.handle.net/2433/168896.
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本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものであるKyoto University (京都大学)
0048
新制・論文博士
博士(工学)
乙第8511号
論工博第2832号
新制||工||954(附属図書館)
UT51-94-J240
(主査)教授 東 邦夫, 教授 今西 信嗣, 教授 若谷 誠宏
学位規則第4条第2項該当
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Lis, Grzegorz P. "Effects of thermal maturation on organic hydrogen-2/hydrogen-1 ratios and hydrogen isotopic exchangeability in Paleozoic marine kerogens (type-II)." [Bloomington, Ind.] : Indiana University, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3223056.
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Thesis (Ph.D.)--Indiana University, Dept. of Geological Sciences, 2006."Title from dissertation home page (viewed June 28, 2007)." Source: Dissertation Abstracts International, Volume: 67-06, Section: B, page: 3014. Advisers: Arndt Schimmelmann; Maria Mastalerz.