Le déploiement des futurs réacteurs à neutrons rapides, dits de Génération IV, est porteur d'améliorations prometteuses sur le plan de l'utilisation des matières premières et de la gestion des déchets. Elles s'accompagneront d'une transformation majeure du cycle et du développement de nouveaux procédés de recyclage, plus simples et plus efficaces. Une des conséquences de cette évolution est l’augmentation de la quantité de radionucléides à vie longue (RNVL) le carbone 14, l’iode 129 et le chlore 36 dans le combustible irradié, rejets du cycle nucléaire. La maîtrise et la réduction de ces rejets passe d’abord par une meilleure connaissance de la quantité de ces radionucléides dans le combustible, formés pendant son irradiation en réacteur. Ce travail de thèse s’inscrit dans l’objectif d’améliorer la mesure des radionucléides carbone 14, iode 129 et chlore 36 dans l’oxyde irradié, non seulement sur les performances analytiques mais aussi sur la minimisation des volumes de rejets liquides et solides engendrés. Une étude bibliographique a été menée afin d’établir le bilan des méthodes existantes pour la mesure de ces RNVL dans l’oxyde irradié. Les conclusions de cette étude ont orienté ce travail selon trois axes principaux : l’utilisation de l’ozone pour oxyder et désorber le carbone 14 de l’oxyde irradié après sa mise en solution ; la proposition d’une méthode d’extraction sélective du chlore 36 contenu dans l’oxyde irradié ; le développement d’une nouvelle méthode d’analyse alliant une séparation par chromatographie ionique couplée à une détection des émetteurs R par scintillation solide pour les trois RNVL / The deployment of future fast neutron reactors, called Generation IV, carries promising improvements in the use of raw materials and waste management. They will lead to a major transformation of the cycle and the development of new recycling processes which will be simplified and more effective. One consequence of this development is the increase of the amount of long-lived radionuclides in spent fuel nuclear waste: 14 carbon, 129 iodine and 36 chlorine. The control and reduction of these radionuclides begins with a better understanding of the amount of these radionuclides in the spent fuel, generated during irradiation in a reactor. The objective of this work consist in improving the measurement of 14 carbon , 129 iodine and 36 chlorine radionuclides in the irradiated oxide, all in reducing the liquid and solid waste generated. A bibliography study was conducted to evaluate the existing methods for measuring these radionuclides in irradiated oxide. The conclusions of this study have oriented the work in three main ways: the use of ozone to oxidize and desorb 14 carbon of the irradiated oxide after solution treatment; the proposal of a selective extraction method for 36 chlorine contained in the irradiated oxide; the development of a new analytical method combining a separation by ion chromatography coupled with detection of R solid scintillation for the three radionuclides

The development of a Doppler Global Veocimetry (DGV) system is described. An argon ion laser has been modified to suit the requirements of DGV. An etalon with high precision tilting control has been mounted in the laser cavity. The backward mirror of the laser cavity has been mounted on a piezotranslator for controlling the laser cavity length. Two iodine cells have been designed and manufactured: one with a bead of iodine in the cell volume, the other with a limited amount of iodine. The iodine absorption line of both cells has been calibrated with good repeatibility. The laser has been stabilized in frequency, so that operations during a measurement session in the lab are simplified. The capabilities of DGV measurements have been tested in two jets, at low and at high speeds. Velocity fluctuations of the jet could be followed, in spite of the highly noisy signals. The first steps towards three velocity component measurements with a single camera in a difficult environment such as the geometry of a turbomchinery cascade have been made. Imaging two views of a target on the same camera sensor is discussed, along with the spatial and luminosity calibration required. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

The aim of this work is to introduce a couple of new exposure scenariosof interest when personnel, family members and general public are externally irradiated from patients treated with Iodine-131. A series of modied ORNL matematical phantoms were used in Monte-Carlo simulations in PENELOPE-2011 to determine dose rates to: a cab driver where thepatient sits in the back seat at opposite side, a newborn child held by an adult patient, a doctor giving treatment to a patient while leaning over the hospital bed and collective effective dose to bus passengers if the patient travels home by bus. The cost to order taxi instead of a public transport ticket for the patient is put in relation to the lowered collective effective dose to general public and compared with other companies price per lowered manSv. Dose rate measurements and the effective half-life of I-131 are used to determine the retained whole body activity at different times post administration. This in combination with the simulations are used to estimate effective doses to the cab driver, bus passengers, newborn and personnel. Whole body-, abdominal- and thyroid source distributions were considered in the patients during simulations. Dose rates within 99.7 % condence intervals were up to: 23.7 ± 0.4, 62.7 ± 0.3, 530 ± 71, 96.8 ± 0.5 µSv/h/GBq, for the cab driver, closest bus passenger, newborn and physician respectively. Collective effective dose to bus passengers is estimated to 291 ± 2 µmanSv/h/GBq. A patient specic tool for estimating more reasonable restriction times on how long to avoid small children is developed, taking into account retained body activity and the home situation for the patient. Effective dose estimations suggest that dose constraints are very unlikely exceeded for the taxi driver, and public transport should be a considered option for thyrotoxicosis patients of lower administered activities and some cancer patients. It is also estimated that hospitals in Sweden are paying 7.6 - 31 MSEK per lowered collective effective dose of 1 manSv by sending patients by taxi instead of bus.

During the last years perovskite materials have taken the photovoltaic community by storm, bringing promises of solar cells with efficiencies comparable to conventional silicon devices but at a lower price. However perovskite solar cells so far are facing two main obstacles, they are unstable in the presence of air, moisture and heat and they are usually toxic due to being based on lead-halide materials. This has spurred investigations into alternative materials with similar properties but without the mentioned drawbacks. Just next to Pb in the periodic table is bismuth (Bi) with just one more electron in its outer-shell, Bi however is less toxic. In this work the perovskite derived compounds of Ag-Bi-I and Cu-Bi-I are characterized and their properties as light absorbing material in solar cell devices are investigated. Devices are prepared by preparing Ag-Bi-I and Cu-Bi-I solutions which are then spin-coated on top of a mesoporous TiO2. A conducting polymer, P3HT, was then deposited and serve as hole transport material. For Ag-Bi-I, the molar ratios of AgI:BiI3= 1:2 and 2:1 were observed with SEM to form homogeneous crystal films with one dominating crystal phase, which by XRD could be determined to most likely have formed a cubic AgBi2I7 crystal structure for the 1:2 ratio and a hexagonal Ag2BiI5 crystal structure for the 2:1 ratio. The Cu-Bi-I materials were not successfully synthesized to form homogeneous films with a dominating crystal phase, although several molar ratios were investigated. All investigated compositions of both Cu and Ag devices showed to in principle work as light absorbing materials, the best Ag-Bi-I device showing a PCE of 1.92%, for the 2:1 ratio, while the Cu-Bi-I devices at best reached 0.32% for a ratio of 1:1. XPS measurements were carried out with a classical in-house XPS using an Al K X-ray source of 1486.7 eV as well as at the Diamond Light Source (UK) synchrotron facility using photon energies of 758 eV and 2200 eV so that a depth resolution of the composition could be observed. Because of their inhomogeneous crystal formation, XPS couldn’t give much useful quantitative information regarding the Cu devices. For Ag devices it was observed that the stoichiometry at the extreme surface deviated from that predicted by XRD, but deeper into the surface the relative ratio of elements approach the predicted ones, hinting towards a different structure at the outermost surface or a lot of surface defects. For all samples, two types of bismuth atoms were observed, metallic (Bi0) as well as a cationic (Bi+x), the later corresponding to Bi atoms which are partaking in the crystal bond. The ratio of metallic to cationic Bi was observed to decrease notably just a few nm below the extreme surface. The effect of the high presence of metallic Bi on final device performance was not concluded with certainty but not believed to be positive. By varying the annealing temperature, after spin coating the light absorber solution on the TiO2, it was observed that lower temperature resulted in a lower ratio of metallic Bi. As final conclusions, it was said that the synthesis method of Cu-Bi-I needs to be improved before those materials can be studied further. The synthesis of Ag-Bi-I is showing much more promise and one can start looking into further optimizing their final device structure to boost efficiency. Both Cu-Bi-I and Ag-Bi-I devices are relatively simple, cheap and energy efficient (with annealing temperatures around 150C) to produce, great aspects for solar cells. UVVis measurements showed they have band gaps around 1.6-1.7 eV which makes them a great potential material for use in tandem solar cells together with a semiconductor of lower band gap such as silicon.

No description available.

La fonctionnalisation directe de liaisons C-H offre une alternative plus économe en atomes et étapes que les traditionnelles méthodes de synthèse basées sur la transformation de molécules pré fonctionnalisées. Ainsi, les réactions d'amination intermoléculaire de liaisons C(sp3)-H avec des nitrènoïdes sont généralement effectuées avec des rendements et des régiosélectivités modérés et utilisent pour cela des catalyseurs coûteux. Dans ce contexte, nous avons créé de nouveaux systèmes bifonctionnels pour la formation de liaisons C-N aliphatiques catalysée par le cuivre et l'argent. Ces systèmes se sont cependant avérés inefficaces dans les conditions réactionnelles utilisées.Les travaux effectués dans le cadre de cette thèse se sont également concentrés sur la fonctionnalisation nucléophile d'anilides par oxydation à l'iode hypervalent. Grâce à cette méthodologie les triflation et triflimidation directes d'acétanilides ont été accomplies dans des conditions oxydantes douces, en présence de triflate et de triflimidate d'argent, respectivement. Ces transformations procèdent avec de bons rendements et présentent une régiosélectivité parfaite pour la position para. / The direct functionalization of C-H bonds offers an attractive, atom- and step-economical alternative to traditional methods based on functional group transformations. Intermolecular C(sp3)-H amination reactions involving nitrene intermediates usually proceed with moderate yields and regioselectivities. In this context, new bifunctional compounds were developed and applied to copper and silver-catalyzed C-N bond-forming reactions. These systems, however, have been found to be ineffective under the reaction conditions.Our research has also focused on the iodine(III)-mediated nucleophilic functionalization of anilides. The direct triflation and triflimidation of acetanilides were accomplished with the use of affordable and easy-to-handle silver(I) triflate or triflimidate respectively, under mild oxidative conditions, exhibiting perfect regioselectivity for the para position. A complete optimization of the reaction conditions and an evaluation of the scope allowed us to prepare a variety of diversely substituted aryltriflates (and nonaflates) in synthetically useful yields.

This dissertation attempts to extend the classes of halogen-containing systems which may be studied using solid-state nuclear magnetic resonance (SSNMR). As line shape broadening due to the quadrupolar interaction (QI) scales inversely with the applied field, high-field magnet technology is indispensable for this research. Combining advanced radiofrequency pulse sequences with high-field wideline data acquisition allowed for the collection of very broad SSNMR signals of all quadrupolar halogen nuclei (i.e., 35/37Cl, 79/81Br and 127I) within a reasonable amount of experimental time. The initial systems for study were of the MX2 variety (M = Mg, Ca, Sr, Ba; X = Cl, Br, I). In total, 9 anhydrous compounds were tested. The effects of hydrate formation were tested on 7 additional compounds. Systematic trends in the observed δiso values (and to a lesser extent, Ω and CQ) were found to be diagnostic of the extent of hydration in these materials. Resolving power was successfully tested using SrBr2, which possesses 4 magnetically unique sites. The composition of CaBr2•xH2O was convincingly determined using SSNMR data and the hydration trends noted above. The sensitivity of the QI to the local bonding environment (e.g., bond distance changes of less than 0.05 Å) was used to refine (when coupled with gauge-including projector augmented-wave density functional theory (GIPAW DFT) quantum chemical computations) the structure of MgBr2, and was used to correct prior NMR data for CaCl2 (earlier accounts had been performed upon a CaCl2 hydrate). During NMR data analysis of certain iodine-containing materials, it was found that standard fitting software (which uses perturbation theory) could not reproduce the observations. Proper analysis required the use of exact simulation software and allowed for the observation of high-order quadrupole-induced effects (HOQIE). This motivated further studies using rhenium-185/187 nuclei, where it was expected that HOQIE would be more dramatic. The observed rhenium SSNMR spectra possessed additional fine structure that had never been observed before experimentally, nor would be expected from currently-available perturbation theory analysis software. Lastly, preliminary results are shown where 127I SSNMR is used to study important supramolecular systems, and the composition of the popular synthetic reagent ‘GaI’ is elucidated.

L’objectif de cette thèse est de réaliser un agent de contraste vasculaire pour tomodensitométrie utilisable en préclinique. En collaboration avec le laboratoire de biogalénique de Strasbourg, ce travail a permis d’obtenir des nano-émulsions iodées produites par diffusion spontanée de surfactif et des nanoparticules iodées produites par ”émulsion - diffusion de solvant”, comme agent de contraste vasculaire. Ces émulsions et particules polymériques présentent en effet, un temps de rémanence vasculaire de plusieurs heures, un pouvoir contrastant suffisant pour un usage en tomodensitométrie (compris entre 170 et 400 HU), la possibilité de les administrer par intraveineuse et une stabilité de plusieurs mois. Les nano-émulsions, notamment celles produites à partir de Lipiodol®, sont les plus prometteuses comme agents de contraste vasculaire de par leur forte radiopacité (475 ± 30 HU) et leur rémanence vasculaire (T1/2 of 4.1 ± 1.10 h). Les nanoparticules iodées à base de PCL présentent un pouvoir contrastant inférieur (168 ± 13 HU) mais elles sont connus pour leur capacité à modifier la libération du principe actif encapsulé. De ce fait même si les agents de contraste de nature lipidique ou ceux inorganiques sont plus performant, elles restent intéressantes pour une visualisation rapide de la distribution du principe actif dans l’organisme. Cette thèse par ailleurs, apporte plusieurs éléments pour la compréhension de la formulation des nano-émulsions obtenues par diffusion spontanée de surfactif et celle des nanoparticules produites par ”émulsion - diffusion de solvant”. Concernant les nano-émulsions, l’influence de l’iodation des huiles et du surfactif a été étudiée autant sur le plan pharmacotechnique que ceux toxicologique et pharmacocinétique. Concernant les nanoparticules à base de PCL, nous avons montré que l’impact du type d’huile et de l’iodation, des polymères PCL et PCL-mPEG et de diverses méthodes de concentration sur la formulation / The aim of this thesis is to formulate a blood pool contrast agent for preclinical X-ray imaging application. In collaboration with the galenic laboratory of Strasbourg, this work has allowed to obtain iodinated nano-emulsions produced by spontaneous diffusion of surfactant and nano-particles produced by iodine ”emulsion - solvent diffusion” as blood pool contrast agent. These emulsions and polymer particles present indeed a vascular persistence of several hours, a sufficient contrast to be use in computed tomography (between 170 and 400 HU), the ability to be administered intravenous and stability of several months. Nano-emulsions, including those produced from Lipiodol®, are the most promising as blood pool contrast media by their high radiopacity (475 ± 30 HU) and vascular persistence (T1/2 of 4.1 ± 1.10 h). Iodinated nano-particles of PCL have a lower X-ray attenuation (168 ± 13 HU), but they are known for their control release of the encapsulated substances. Therefore even if inorganic or lipidic contrast agents show a better contrast, they remain attractive for rapid visualization of the co-encapsulated substance distribution in the body. This thesis also introduced several features for understanding the formulation of nano-emulsions obtained by spontaneous diffusion of surfactant and the nano-particles produced by ”emulsion - solvent diffusion.”

This thesis focuses on the analysis of heavy noble gases (argon, krypton and xenon) and halogens (chlorine, bromine and iodine) in Martian meteorites. In the absence of a sample-return mission, Martian meteorite analysis is essential for establishing evidence for an active fluid system, evaluating the potential for life and understanding the formation and evolution of Mars. Noble gas analysis has multiple applications for Martian meteorite study, as described in this thesis. The noble gas isotopic signatures of Earth’s atmosphere, Martian atmosphere and Martian interior are sufficiently different that they can be distinguished through noble gas analysis. Analysis of bulk and mineral separates of shergottites showed that Martian atmospheric Xe was distributed evenly amongst samples, whilst terrestrially weathered samples contained elevated concentrations of terrestrial atmospheric Xe. Both atmospheric components were introduced by weathering. Shock redistribution is responsible for the distribution of Martian atmosphere into more retentive sites. Crustal contamination may be responsible for the presence or absence of detectable 129Xe from the Martian atmosphere. Halogen abundances can be determined as an extension of the Ar-Ar dating technique. As the halogen system on Earth acts as a tracer for important fluid related processes, Martian halogen abundances in meteorites may provide a tracer for the Martian fluid system. Analysis of bulk and mineral separates of nakhlites showed that halogens are distributed amongst minor phases and clear variation of Br/Cl and I/Cl ratios was observed amongst samples. Elevated I concentrations in low temperature releases of finds NWA 998 and MIL 03346 are consistent with terrestrial contamination. Analysis of Nakhla, (a meteorite fall), showed a trend of elevated Br/Cl and I/Cl ratios in crush and low temperature releases, consistent with Br/Cl ratios observed in Martian rocks, soils and weathering products. In contrast, high temperature releases had lower I/Cl and Br/Cl ratios, which are broadly comparable to the terrestrial mantle. This trend may represent mixing of hydrothermal fluids (low Br/Cl and I/Cl) and surface brines (high Br/Cl and I/Cl). An impact-induced hydrothermal system may provide a mechanism for mixing of both fluid types. The crystallisation ages of nakhlite meteorites were determined using the Ar-Ar dating technique. The apparent ages measured were similar to previous Ar-Ar analysis, and older than reported for other chronometers. Previously unrecognised components were observed, including evidence for a trapped hydrous fluid. This Cl-rich component showed strong correlation with 40Ar and had 40Ar/36Ar and 40Ar/129XeXS ratios consistent with Martian atmosphere. As this component was released during crush and low temperature analysis, fluid inclusions formed by percolation of brines from the Martian surface are likely hosts. Both finds showed clear evidence of a trapped component with 40Ar/36Ar ratios similar to either terrestrial atmosphere or the Martian interior. A further component observed in olivine phases had low 40Ar/36Ar ratios, and likely formed by the release of 36Ar formed by cosmic-ray spallation reactions on iron.

Carcinomas papilíferos (CP) estão relacionados à ativação da via de sinalização MAPK por diversos oncogenes. Estudos têm relacionado a incidência de CP com a disponibilidade de iodo, um dos mais importante reguladores da função tiroidiana. Recentemente, nosso grupo descreveu que a inibição da via de sinalização TGF<font face=\"symbol\">b pode estar vinculada ao desenvolvimento de CP. Nosso objetivo foi avaliar os efeitos do excesso de iodo na transformação de células tiroidianas. Utilizamos células PCCL3 com indução do oncogene RET/PTC3, tratadas com excesso de iodo. Observamos que o iodo reduziu a proliferação, sem alterar a morte das células e recuperou a expressão de genes específicos tiroidianos, evento geralmente vinculado à transformação maligna tiroidiana. O tratamento com excesso de iodo, ainda, reduziu a expressão de proteínas envolvidas na via MAPK e promoveu o restabelecimento da expressão da via TGF<font face=\"symbol\">b, uma importante via inibitória da proliferação de células tiroidianas. Concluímos que o excesso iodo tenha uma ação antioncogênica durante a transformação maligna tiroidiana. / Papillary Carcinomas (PC) are frequently related to MAPK signaling pathway, activation by several oncogenes. Recent studies had related PC incidence and iodine availability, one of the most important thyroid function regulators. Our group has recently showed that TGF<font face=\"symbol\">b pathway inhibition is directly related to PC development. Our aim was to evaluate iodine excess effects during thyroid cells transformation. We used the PCCL3 cells with RET/PTC3 oncogene induction, treated with iodine excess. We observed that iodine reduced the cell proliferation, not altering cell death and recovered thyroid specific genes expression, event frequently liked to thyroid cells malignant transformation. Iodine excess treatment also reduced MAPK proteins expression and reestablished TGF<font face=\"symbol\">b pathway components expression, an important inhibitory pathway of epithelial cells. We can conclude that iodine excess treatment plays an antioncogenic role during thyroid malignant transformation.