Dissertations / Theses on the topic 'Milieux sulfurés'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Milieux sulfurés.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Guida, Manrique Leydy Carolina. "Mécanismes contrôlant la séquestration du gadolinium, du rhénium et du sélénium dans des conditions de faible teneur en oxygène." Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALU015.
Trace elements, despite their scarcity (less than 100 parts per million) on Earth, serve diverse purposes: some act as micronutrients, while others, known as critical metals, possess unique industrial and medical applications. In oxygen-deprived natural aquatic systems electron transfers involve biogeochemical reactions catalyzed by iron, sulfur and trace elements. Understanding their reactivity in these environments remains a challenge. My Ph.D. research focus on filling this knowledge gap concerning three specific elements (rhenium (Re), selenium (Se), and gadolinium (Gd)). They exist in various chemical aqueous species in water: monovalent anion (perrhenate, ReO4—), divalent anion (selenate, SeO42—and selenite, SeO32—) or cation (Gadolinium, Gd3+). Rhenium is a critical metal, while selenium is a bioessential element at low levels, and becomes toxic in higher concentrations. Gadolinium is a rare earth element and a critical metal as well, due to its wide use as a contrast agent in magnetic resonance imaging (MRI).These elements are most concentrated in marine sediments formed in oxygen-deprived environments. Common mineral phases include pyrite (FeS2) and magnetite (Fe3O4) depending on sulfide content in those environments, and origin (autogenic vs. detritic, e.g., from volcanic rocks) of the particles. My research, presented across four chapters, investigates surface reduction (Re(VII), Se(VI) and Se(IV)) and the sorption (Gd(III)) processes on/into magnetite and pyrite particles. Employing various analytical methods such as XAFS spectroscopy, STEM-EELS spectro microscopie and MC-ICP-MS, our study reveals distinct reactive pathways. Re(VII) reacts with sulfidic water to form Re(III, IV, V)2S7 nanoparticles, while at lower concentrations Re is reduced and incorporated into particles, in different pathways characterized by less isotopic fractionation with pyrite than with magnetite. We also show that pyrite nanoparticles reduce Se(VI) and Se(IV), down to surface Se(0) or structure Se(-I) depending on whether adsorption or co-precipitation occurs. Lastly, Gd substitutes for Fe(III) in magnetite nanoparticles up to 5% Fe substitution by Gd. We attempt to unify the affinity behaviour of these and other trace elements with anoxic Fe-bearing sediments in the light of the hard and soft acids and bases principle.The study provides new insights into the mechanisms that govern the sequestration of metals and metalloids in sedimentary settings. The significance of this research lies in its relevance to contemporary scientific and technological endeavours, particularly in understanding how processes in Fe and sulfidic systems work like trace elements, Fe and S mobility, mass balance in the global sedimentary cycles to the exploration, mining and recycling of potential repositories of metals. Furthermore, it enhances our current understanding of the use of palaeoenvironmental proxies to reconstruct the Earth's formation. Finally, this study also has implications for the treatment of nuclear waste and pollution, particularly in the management of selenium (Se) and gadolinium (Gd) contamination
Soggiu, Nicolas. "Oxydation des sulfures par transfert monoélectronique photoinduit en milieux homogène et hétérogène." Pau, 2000. http://www.theses.fr/2000PAUU3006.
Li, Ning. "Mécanismes de corrosion des couches minces d'argent en milieu sulfuré." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00833174.
Li, Ning. "Mécanismes de corrosion des couches minces d’argent en milieu sulfuré." Paris 6, 2012. http://www.theses.fr/2012PA066103.
Silver thin films (10 nm of thickness) are widely used in the glass industry for their high performance for thermal insulation of buildings. However, they are prone to deteriorate due to corrosion during the transport and storage. The aim of this thesis is to better understand the sulphidation mechanisms of silver thin films, in HS- containing aqueous solutions, with a model system Ag/Ti/SiO2, prepared by PVD. Electrochemical behavior, surface structure modifications, kinetics aspects and surface chemistry were investigated at macroscopic and atomic scales. An electrochemical behavior which is similar to that of thicker films has been observed. The mechanism of 2D sulphur adsorption on a single crystal Ag(111) in 1 mM Na2S + 0. 1 M NaOH has been explored by EC-STM. (23 × 23)R. 30°, (3 × 3)R. 30° and (7 × 7)R. 19° superstructures are formed with potential-driven increasing uptake of sulphur up to saturation. The terraces edges (steps) appear as preferential reaction sites, and by extrapolating to polycristalline films preferentially oriented (111), grain boundaries could play this role. The kinetics of the spontaneous formation of silver sulphide at open circuit potential (OCP) has been followed in situ by EQCM. The average growth rate of Ag2S is estimated to be 750 ng. Cm-2. Min-1. The formation of 3D sulphide islands has been demonstrated: the surface coverage of sulphur increase until around 85%, while the islands grow in height. The sulphidation increases the surface roughness and destroys the initial stratified structure of the stack
El, Hajjaji Souad. "Etude de la corrosion d'aciers inoxydables spéciaux en milieux phosphoriques pollués par des sulfures." Toulouse, INPT, 1994. http://www.theses.fr/1994INPT025G.
Carassou, Sébastien. "Déclenchement du clivage dans un acier faiblement allié : rôle de l'endommagement ductile localisé autour des inclusions." ENSMP, 1999. http://www.theses.fr/1999ENMP0935.
Roidot, Nathalie. "Trifluorométhylation à l'aide de trifluorométhanesulfinate de sodium en milieu oxydant." Lyon 1, 1992. http://www.theses.fr/1992LYO10190.
Chanson, Claude. "Etude du comportement de l'électrode de fer en milieu alcalin : influence des ions sulfures." Bordeaux 1, 1986. http://www.theses.fr/1986BOR10575.
Chanson, Claude. "Etude du comportement de l'électrode de fer en milieu alcalin influence des ions sulfures." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb375966067.
Zal, Franck. "Structures des hemoglobines extracellulaires d'annelides et de vestimentiferes colonisant des milieux extremes les hemoglobines face aux sulfures." Paris 6, 1996. http://www.theses.fr/1996PA066441.
Bourdoiseau, Jacques-André. "Rôle des espèces sulfures sur le comportement d'un acier non allié en milieu de stockage des déchets radioactifs de type C : interaction sulfures / produits de corrosion." Phd thesis, Université de La Rochelle, 2011. http://tel.archives-ouvertes.fr/tel-00688136.
Bourdoiseau, Jacques-André. "Rôle des espèces sulfures sur le comportement d’un acier non allié en milieu de stockage des déchets radioactifs de type C : interaction sulfures / produits de corrosion." Thesis, La Rochelle, 2011. http://www.theses.fr/2011LAROS328/document.
This PhD work deals with the nuclear waste disposal. In France, it is envisaged byAndra (French national radioactive waste management agency) that high-level radioactivewastes will be confined in a glass matrix, stored in a stainless steel canister, it self placed in a carbon steel overpack. The wastes will then be stored at a depth of ~500 m in a deep geological repositery, drilled in a very stiff (indurated) clay (argillite) formation. The kineticsof corrosion expected for the overpack in this disposal concept are low and will stay low if the somehow protective rust layer that will develop initially on the steel surface remains undamaged. Local changes of the physico-chemical conditions may however degrade this layer and induce accelerated kinetics of corrosion. In particular, the growth of sulphate reducing bacteria (SRB) close to the steel overpack cannot be excluded and the sulphid especies these micro-organisms produce may modify the corrosion process. The aim of this work was then to achieve a better understanding of the corrosion system constituted with steel, its rust layer mainly made of siderite FeCO3, and a sulphide-containing electrolyte.First, it proved necessary to characterise the iron sulphides involved in the corrosion processes by Raman micro-spectroscopy so as to study their formation and transformation mechanisms in various conditions of Fe(II) and S(-II) concentration, pH, temperature andaeration. It could be demonstrated that the Raman spectrum of mackinawite FeS, thecompound that precipitated in any case from dissolved Fe(II) and S(-II) species with the experimental conditions considered here, depended on the crystallinity and oxidation state.Moreover, the mechanisms of the oxidation of mackinawite into greigite Fe3S4 in acidicanoxic solutions at 80°C could be described. Finally, iron sulphides, often present on archaeological artefacts, could be identified using Raman micro-spectroscopy. The compounds present were mainly mackinawite and greigite.Secondly, to investigate the nature and properties of carbonated rust layers, carbonsteel electrodes were polarised anodically in NaHCO3 electrolytes continuously de-aerated byan argon flow. The experiments were performed at room temperature. The carbonated greenrust was observed to form at 0.003 and 0.1 mol L-1 NaHCO3 whereas FeCO3 was obtained atthe largest concentrations (0.5 and 1 mol L-1). Additional experiments were performed similarly in solutions of NaHCO3 and Na2SO4. Chukanovite, the Fe(II) hydroxycarbonate with formula Fe2(OH)2CO3, could be obtained in solutions containing 0.03 mol L-1 of eachsalt.Finally, interactions between sulphide species and corrosion products were studied.Siderite, goethite and lepidocrocite proved to be reactive towards sulphide. So, it seems clear that sulphide species produced by SRB should interact with the rust layer before to reach the metal underneath. Tests were performed with ferrous archaeological artefacts immersed 2months in anoxic sulphide-containing electrolytes to demonstrate it. The main effect of theimmersion was the formation of iron sulphide at the interface between the dense corrosion products layer, mainly constitute of siderite, and the transformed medium, where minerals ofthe soil are mixed with corrosion products. Sulphide species were not detected at the vicinityof the iron surface
Sévêque, Jean-Louis. "Etude experimentale de la dissolution des mineraux sulfures en milieu oxydant : application a la prospection miniere." Paris 6, 1986. http://www.theses.fr/1986PA066059.
Gissinger-Bonnissel, Pascale. "Comportement du mercure (II) en milieu aqueux en présence d'oxydes (silice et goethite) et de sulfures (pyrite)." Nancy 1, 1997. http://www.theses.fr/1997NAN10199.
Matton, Sophie. "Génération de rayonnement terahertz par photomélange et développement d'une détection homodyne : application à la caractérisation de polluants atmosphériques et de milieux diélectriques." Littoral, 2004. http://www.theses.fr/2004DUNK0144.
The aim of this thesis work was to exploit frequency conversion by photomixing provifing a widely tunable source to make a terahertz spectrometer with improved spectral resolution than those obtained by pulsed methods. After the analytic description of the terahertz generation process by photomixing, the experimental characterization of the photomixers with planar and vertical configurations, used in this study, allowed the developed model to be checked. It was etablished that the vertical photomixer display better efficiency and thermal dissipation, however a smaller bandwidth compared with the planar photomixer. The characteristics of the terahertz spectrometer have been determined from a study of the hydrogen sulfide molecule. The spectrometer has a spectral purity of 5 MHz (FWHM) and a sensitivity of a few 10‾4 cm‾1 around 1 THz. Its spectral coverage spans from 100 GHz (3 mm) to 3 THz (100 [micro]m) and its ease are the major advantaged. This permitted the intensity and the colisionnal broadening of several rotational transitions of the base level of carbonyl sulfide (OCS) to be measured. Finally, photomixing also offers the possibility to perform coherent detection of terahertz radioation. The time independant signal generated depends upon both amplitude and phase of the terahertz field detected. The absorption and the dispersion of dielectric medium was measured, as well as the anormal dispersion near the rotational transition of OCS
Marques, António. "Oxydation par le peroxyde d'hydrogene de sulfures modeles de l'hyperite, catalysee par les metalloporphyrines dans l'ethanol et dans les milieux organises aqueux." Paris 7, 1999. http://www.theses.fr/1999PA077154.
WITZ, CATHERINE. "Etude des proprietes optiques des sulfures de terres rares et de leur utilisation en tant que pigments dans des milieux heterogenes diffusants." Paris 6, 1995. http://www.theses.fr/1995PA066818.
Seveque, Jean-Louis. "Etude expérimentale de la dissolution des minéraux sulfurés en milieu oxydant application à la prospection minière /." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37601217w.
Gely, Roger. "Contribution à l'étude thermodynamique et cinétique de la lixiviation du sulfure de zinc en milieu sulfurique." Paris 6, 1987. http://www.theses.fr/1987PA066051.
Gely, Roger. "Contribution à l'étude thermodynamique et cinétique de la lixiviation du sulfure de zinc en milieu sulfurique." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb376053561.
Monnot, Martin. "Etude des mécanismes de corrosion sous contrainte des aciers inoxydables supermartensitiques en milieu H2S." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI046/document.
Super martensitic stainless steels are widely used in the oil and gas industry, but failures occurred in service under severe conditions. The aim of this study is to provide a better understanding of the stress corrosion mechanism in H$_2$S medium. For this purpose, laboratory heats have been casted with different molybdenum contents, a component known to improve corrosion resistance. These additions of alloying elements then involve a fine characterization of the microstructure, in order to grasp the mechanisms of rupture. Particular attention has been paid to the evolution of the retained austenite and residual ferrite fraction with the heat treatments of quench and annealing which are commonly practiced on these grades. Then, by electrochemical measurements without mechanical stress, the addition of molybdenum was identified as beneficial for the passivity of the grade in the H$_2$S medium. And for 2.25% molybdenum contents, corrosion products have been identified as mainly nickel sulfides, which are inhibitors of hydrogen recombination. Subsequently, corrosion tests under static and dynamic load coupled to electrochemical impedance measurements show a beneficial effect of molybdenum and residual austenite. In particular, molybdenum reduces the defects of the passive film. A finite elements model simulates the slow strain rate traction tests taking into account the hydrogen embrittlement. In order to use experimental parameters, an electrochemical permeation cell was implemented and used to measure the hydrogen diffusion coefficient within our different heats. A good match with the experimental results was obtained with this model and a parametric study was carried out on the diffusion coefficient and the hydrogen interfacial concentration. Finally, a synthesis provides the proposal of a stress corrosion mechanism divided in two steps: the passive film resistance to limit the hydrogen absorption in the matrix and the trapping of the hydrogen by the residual austenite in function deformation
Naveau, Aude. "Etude et modélisation de la sorption d'ions à la surface de sulfures métalliques en conditions de stockage en milieu géologique profond." Reims, 2005. http://theses.univ-reims.fr/exl-doc/GED00000168.pdf.
The storage of high-level nuclear wastes in a geological disposal is based on the concept of confinement by a multibarrier system. Transport by groundwaters is the most likely means for radionuclides to migrate through the engineered and geological barriers. Understanding processes which could delay this migration is therefore fundamental to ensure the timelessness of a deep geological repository. The present study was initiated to investigate sorption processes between sulfides minerals, present as inclusions in temperate soils, and two long-life fission products, iodine and selenium. All experiments were performed in strict anoxic conditions in order to prevent the studied solids (pyrite FeS2 and chalcopyrite CuFeS2) from oxidation. Potentiometric studies showed a weak reactivity of the metallic sulfides surfaces attributed to a low specific surface. Sorption experiments showed no affinity between iodide and metallic sulfides surfaces whereas selenium was well retained by the differents solids. Spectroscopic studies (XPS and XANES) showed a reduction of SeIV to Se-II on the sulfide surfaces. Selenium behaviour was finally described with the diffuse layer model using the surface complexation theory
Naveau, Aude Dumonceau Jacques. "Etude et modélisation de la sorption d'ions à la surface de sulfures métalliques en conditions de stockage en milieu géologique profond." Reims : S.C.D de l'Université, 2005. http://scdurca.univ-reims.fr/exl-doc/GED00000168.pdf.
Abdi, Djamila. "Application de l'electrode a disque tournant a l'etude du comportement electrochimique du cuivre en milieu neutre et en milieu acide en absence et en presence d'especes sulfurees." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13176.
Aumond, Virginie. "Spéciation du cuivre en milieu hydrothermal profond et dans les zones de suintements froids." Phd thesis, Université de Bretagne occidentale - Brest, 2013. http://tel.archives-ouvertes.fr/tel-01057808.
Martinez, Mathieu. "Spéciation et isotopie du soufre inorganique en milieu aqueux." Thesis, Pau, 2019. http://www.theses.fr/2019PAUU3009/document.
Sulfur is present in the hydrosphere at oxidation states ranging from sulfate (+VI) to sulfide (-II) and including many species at intermediate oxidation states, such as elemental sulfur (0), thiosulfate (-I, V) and sulfite (IV). These species in particular are considered as important intermediates in biological and abiotic reactions (oxidation, reduction or disproportionation) involving sulfur and are frequently coupled to the biogeochemical cycles of carbon, nitrogen, oxygen and iron.Sulfur cycle processes are studied by measuring the concentrations of different species containing sulfur (speciation analysis) and by measuring their respective isotope ratios (isotopic analysis). Analytical difficulties are frequently encountered because sulfur species, especially intermediate valence species, are present in low concentrations and are difficult to isolate. Thus, the isotope ratios of intermediate valence species are rarely determined. Methods for measuring isotope ratios of inorganic sulfur species, particularly the least abundant intermediate species, would be a great assistance in deciphering sulfur cycle processes.In this context, this thesis work was devoted to the development of analytical strategies combining speciation and isotopic analysis of sulfur, in order to measure sulfur isotope ratios of several inorganic species that can be simultaneously present in liquid samples. First, a speciation method for quantifying sulfite, sulfate and thiosulfate by liquid chromatography coupled to high-resolution inductively coupled plasma mass spectrometer (LC-HR-ICP-MS) was set up. Then, an off-line approach was developed for the isotopic analysis of sulfide, sulfate and thiosulfate. It consisted of a sample preparation by sequential precipitation of the sulfur species, followed by elemental analyzer coupled to isotope ratio mass spectrometer (EA-IRMS) analysis. This method made it possible to determine the δ34S values of sulfide, sulfate and thiosulfate with measurement uncertainties below 0.5 ‰ for water samples containing at least 27 µg of sulfur. This method has been applied to the study of spring waters and deep aquifer waters and the monitoring of isotopic fractionation of sulfur in a culture of sulfate-reducing bacteria.Moreover, an on-line analytical method coupling anionic separation and detection by multicollector inductively coupled plasma mass spectrometer (LC-MC-ICP-MS) has been developed for the determination of δ34S values of sulfite, sulfate and thiosulfate. This method allowed us to determine δ34S of sulfite, sulfate and thiosulfate for water samples containing as little as 1 µg of sulfur per species with measurement uncertainties below 0.6 ‰
Hoerner, Bertrand. "Corrosion sous contrainte de l'acier inoxydable supermartensitique 12chrome 4. 5nickel 1. 5molybdène dans un milieu sans sulfure d'hydrogène." Saint-Etienne, EMSE, 2007. http://www.theses.fr/2007EMSE0017.
Supermartensitic Stainless steels are used in the oil and gas application and have a sensitivity of the heataffected zone (HAZ) to stress corrosion cracking. We carried out slow strain rate tensile test to characterize cracking of the HAZ in a H2S free environment. The study focus on the effect of carbon, the reassignment of the ZAT and post weld treatment on the cracking resistance. Our study show that the ZAT is sensitive to stress corrosion cracking in the free H2S environment and that the reassignment during welding led to the creation of intergranular chromium carbides which induce a depleted zone (15 nm). The cracks can grow by dissolution along this zone. We show that the increase of the chromium / carbon ratio beyond a threshold reduces the density of carbides and had a discontinuous depleted zone which inhibits cracking. We observe that the application of a post-weld heat treatment allows desensitisation around chromium carbides: after treatment at 650 ° C for 20 minutes, no crack appears in HAZ
Thomazeau, Isabelle. "Résolution temporelle, à l'échelle subpicoseconde, de non-linéarités optiques du 3ème ordre dans des milieux isotropes transparents." Paris 11, 1986. http://www.theses.fr/1986PA112148.
Optical Kerr effect technique has been used to time resolve the third order nonlinearities of silicate glasses. Among them SF59 Schott glass may be a good optical shutter well suited for subpicosecond pump pulses. Its efficiency is of the same order of magnitude as that of liquid CS2 and takes advantage of temporal resolution limited by the pulses widths. Wave mixing experiments have been performed on liquid CS2, in the 620 nm – 650 nm frequency range. The associated electronic nonlinearities have been measured and the Kleinmann symmetry rule verified. The temporal behaviour of transient phase gratings has been analysed for a liquid (CS2) and glass (SF59). Two geometries have been built up: Raman-Nath and Bragg. The results obtained confirm the electronic and molecular theories which describe the relations encountered by the elements of the third order susceptibility tensor
Hacquard, Elodie. "Interactions des cations métalliques avec les sulfures divisés en milieu basique : application à la fixation du Ni(II) sur la pyrite et l'arsénopyrite." Nancy 1, 1997. http://www.theses.fr/1997NAN10019.
Merzouk, Anissa. "Contrôle des variations à court terme de la production biologique de diméthylsulfure (DMS) en milieu marin." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24205/24205.pdf.
Dimethylsulfide (DMS) is a biogenic gas exerting a cooling effect on climate by promoting cloud formation, thus decreasing the amount of solar radiation entering the atmosphere. DMS is produced in the oceans from the degradation of dimethylsulfoniopropionate (DMSP) synthesized by marine phytoplankton. Some algal DMSP-producers have the capability to directly produce DMS, but a large part of the production of DMS is believed to occur indirectly, through the release of algal DMSP and its uptake and utilization by bacteria. DMS production represents less than 10% of the DMSP degraded by bacteria, which utilize it mainly as a source of sulfur. Short-term variations of the biological DMS production and its controlling factors were studied in the St. Lawrence Estuary, the northeast Pacific and the northwest Atlantic. In the St. Lawrence Estuary, DMSP and DMS concentrations exhibited large and rapid variations with maxima around noon and minima during the night. These variations were largely explained by the diurnal vertical migration of DMSP-rich dinoflagellates associated with an increased DMSP and DMS production under high solar irradiance during the day. In the NE Pacific, the low prevailing iron concentrations favoured a DMSP-rich algal community. The iron enrichment induced a decrease in DMS relative to non-enriched waters due to a change in the phytoplankton community toward DMSP-poor diatoms and an increase in the abundance and activity of bacteria. This growing bacterial community modified its DMSP utilization and produced little DMS. In the NO Atlantic, the decline of the diatom spring bloom was characterized by a decrease in DMSP concentrations in surface waters. DMSP consumption and DMS production by bacteria also rapidly decreased, probably because they satisfied their metabolic requirements with other organic substrates more readily available than DMSP. The pools and biological processes of the DMS(P) cycle vary at scales of hours and days. The study of these short-term variations is needed to accurately measure DMS production and to better assess its effect on climate.
Le, nedelec Tom. "Synthèse et évaluation de silices hybrides fonctionnalisées pour la récupération de l'uranium en milieu sulfurique." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTS084.
The aim of this thesis is to develop silica-based hybrid materials for selective extraction of Uranium from acidic and highly complexing media, such as ore leaching solutions or effluents generated in manufacturing plants of nuclear fuel cycle.The research project has several axes:• Study of the performance of different organic ligands (with nitrogen and phosphorus) for the extraction of uranium on solid.• Study of the influence of the link between the material and the ligand on the Uranium extraction performance.• Influence of the functionalization method (adsorption, grafting) and the adsorption surface on uranium extraction performances and mechanisms (EXAFS study)• Development of a method for the synthesis of silica-based hybrid materials with template effect adapted to the Uranium ores dissolution media.In each of the parts the approach goes from synthesis of the materials to evaluation of the materials performances for Uranium extraction, the solid characterization and the extraction mechanism comprehension
Ravix, Lilian. "Etude par émission acoustique des mécanismes de fragilisation par l'hydrogène des aciers peu alliés." Lyon, INSA, 2005. http://theses.insa-lyon.fr/publication/2005ISAL0085/these.pdf.
Hydrogen embrittlement (HE) is observed in H2S containing environments on low alloy steels used for casing application. For a better understanding of this corrosion process, the normalized SSC tensile test (Nace TM 0177-96 Method A) was instrumented by acoustic emission (AE). In the configuration of test, the study of steels with different HE susceptility shows the presence of very emissive AE sources (HIC, FeS), hidding other AE sources (H2, SSC). For Hydrogen Induced Cracking, the monitoring of acoustic energy evidences that crack initiation, induced on segregated zones of the microstructure, is enhanced by stress application. For Sulphide Stress Cracking, statistical treatment of acoustic data allows the localization of the cracks on the specimens about fifty hours before rupture. Cracks associated with SSC mode of degradation initiate on the steel surface and mechanisms associated to their development are linked to hydrogen uptake
PASHALIDIS, SOTIRIS. "Etude du sulfure de dimethyle dans la basse troposphere en milieu oceanique non pollue : metrologie et etude de cas concrets." Paris 7, 1990. http://www.theses.fr/1990PA077216.
Medoukali-Daamach, Sakina. "Contribution a l'etude des phenomenes cinetiques en extraction liquide-liquide : cas de l'extraction du palladium (ii) par les sulfures de dialkyle en milieu acide chlorhydrique." Paris 6, 1988. http://www.theses.fr/1988PA066629.
Medoukali-Daamach, Sakina. "Contribution à l'étude des phénomènes cinétiques en extraction liquide-liquide cas de l'extraction du palladium (II) par les sulfures de dialkyle en milieu acide chlorhydrique /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376160408.
Charlot, Alexandre. "Synthèse et Evaluation de silices hybrides mésoporeuses pour l'extraction de l'uranium en milieu sulfurique." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2016. http://www.theses.fr/2016ENCM0006/document.
Nuclear industries are perpetually looking for technical, economic and environmental progresses. Important volumes of acidic waste are generated by nuclear plants of the front end. The extraction of uranium from these solutions is required to decontaminate effluents (decrease of the radioactivity) and value uranium (reincorporation in the cycle). Uranium leaching is mostly achieved using sulfuric acid leading to the production of aqueous effluents that contain a large grade of sulfate complexes. In such conditions, uranyl sulfate complexes constitute the predominant uranium species in solution and its extraction represents a real scientific and technological challenge. Commonly, precipitation, solvent extraction or solid phase extraction are used. The last one is particularly adapted for low grade solutions due to it weak environmental footprint (no solvent are handling) and the facility of the process involved (i.e. fixed bed column). Among the available solid-phase extraction candidates, hybrid mesoporous silicas get a crucial part. They develop a very high specific surface areas and a driven porosity which give them a high potential of extraction capacities.In this manuscript the tailoring and the evaluation of hybrid mesoporous silicas have been investigated. Firstly, the work focus on the organic part grafted by post-synthetic pathway, the N,N-dialkylcarbamoylphosphonate based molecules have been identified to get interesting extraction properties. This study emphasizes that acid groups are required and that alkyl substituents get a real importance in the extraction efficiency. On the second hand, the role of pore size has been investigated. The results obtained disclosed that pores size diameters directly impact the grafting ratio as well as the homogeneity of the material: (1) materials with a pore size below 3 nm are heterogeneously functionalized due to steric issues, (2) a homogeneous organic monolayer grafted onto the silica skeleton occurs when the pore size ranges from 3 nm to 20 nm and (3) functionalization of material having pore size above 30 nm results in an organic multilayer covalently linked to the surface. The organic self-organization drives the extraction efficiency, only monolayers lead to promising results. At the saturation state, two molecules are required to extract one uranyl ion. To describe the molecular scale of the uranyl complex onto the solid, the local structure has been investigated by a parametric study and spectroscopic techniques (IR, EXAFS and DRX). Results reveal that two diamido-phosphonates are involved in the uranyl extraction. By this work, it is shown how the molecular scale helps to understand the macroscopic phenomena.Finally, continuous extraction in a fixed bed column confirms the extractive properties obtained in batch mode experiments and points out the potential of such material to be reused several times without any damages
Maurer, Olivier. "Etude de la distribution des espèces soufrées et de la production d'hydrogène sulfuré dans les stockages de gaz naturel en aquifères." Marne-la-vallée, ENPC, 1992. http://www.theses.fr/1992ENPC9230.
Observations of natural gas quality withdrawn from natural gas aquifer starages often shows that desulfuration is needed but that hydrogen sulfid production is marginal compared to volumes. After adopting a geochamical and pluridisciplinal approach, realising an analytical program and performing specifical tools development, we propose a hydrogen sulfid formation model. Based on gas-water equilibrium and dissolved sulfur production, this model oppses a central area, desulfurized by acid but non-sulfurous gas injection to a peripheric area, enriched in sulfurous water and where mixing phenomenons are important. The major geochemical observation consists in storage water carbonatation, methane oxidation. Active parameters in the hydrogen sulfid production are essentially sulfurs, sulfates and alkalin ions water concentrations,, carbon dioxide and carbon oxysulfu gas content, solid carbonates and ferrous iron wzater saturations, sulfate-reducing, methanogenic and methanotrophic bacterial activities, as well as acid, temperature, pression and redox conditions in the medium. An isotopic synthesis also shows that jurassic sulfates of the parisian Basin are affiliated to a triasic sulfate, that dissolved natural sulfurs originate from the fossile bioreduction of those sulfates, and how dissolved carbonates in the gas exploited areas are carbon 13 enriched
Monroy, Fernandez Marcos Gustavo. "Biolixiviation-cyanuration de minerais sulfurés aurifères dans des dispositifs de percolation : comportement des populations de Thiobacillus ferrooxidans et influence de la minéralogie et des conditions opératoires." Vandoeuvre-les-Nancy, INPL, 1993. http://docnum.univ-lorraine.fr/public/INPL_T_1993_MONROY_FERNANDEZ_M_G.pdf.
Gonzalez, Chavez Jose Luz. "Influence des conditions de potentiel et de complexation sur les mécanismes de flottation des minéraux sulfurés : Application à la séparation arsénopyrite/pyrite." Nancy 1, 1987. http://www.theses.fr/1987NAN10179.
Ruel, Fiona. "Contribution électrochimique à l’étude de la corrosion sous contrainte des aciers inoxydables lean duplex en milieu purement chloruré et sous présence de sulfure d’hydrogène." Thesis, Saint-Etienne, EMSE, 2014. http://www.theses.fr/2014EMSE0743/document.
Lean duplex stainless steels, with low content of nickel and without molybdenum, represent an economic alternative for desalting plants and petroleum industry. For these uses, steel have the particularity to be exposed to very aggressive environments inducing phenomenon of Stress Corrosion Cracking as chlorides, hydrogen sulphur, high temperatures or acids.This study is divided in two parts dedicated to two different environments. The first part is devoted to chloride middles and the second to hydrogen sulphur middles. In both parts, the understanding of phenomenon linked to the stress corrosion cracking of lean duplex is studied on the grade steel S32304, then is compared to the behaviour of grade steels S32202 and S32101. The topics treated in this report are notably the influence of boiling environments on the cracking resistance of stainless steels, the mechanism of unpassivation and selective dissolution of lean duplex, the different modes of cracking in presence of hydrogen sulphur, and the initiation of stress corrosion cracking assisted by hydrogen sulphur
Pébère, Nadine. "Approche des mécanismes de la corrosion d'un acier au carbone en milieu sulfhydrique et de son inhibition à l'aide de molécules organiques tensioactives : exploitation couplée des données électrochimiques stationnaires et transitoires." Toulouse, INPT, 1987. http://www.theses.fr/1987INPT032G.
Lacombe, Marielle. "METHODES ELECTROCHIMIQUES POUR L'ANALYSE IN SITU DE COMPOSES BIOACTIFS EN MILIEU OCEANIQUE." Phd thesis, Université Paul Sabatier - Toulouse III, 2007. http://tel.archives-ouvertes.fr/tel-00256800.
Smanio-Renaud, Véronique. "Etude des mécanismes de Fragilisation Par l'Hydrogène des aciers non alliés en milieu H2S humide : contribution de l'émission acoustique." Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0129/these.pdf.
Many steel equipments used in oil and gas industry are subjected to wet H2S cracking. In order to improve the understanding of this type of cracking, Acoustic Emission (AE) was used for the monitoring of steels exposed to wet H2S. AE related to both most important crackin modes in this media, i. E. , Hydrogen lnduced Cracking (HIC} and Sulfide Stress Cracking (SSC), were discriminated from the other AE sources signals (H2 evolution, iron sulfide layer formation). Using this methodology, real-time monitoring of cracking is possible, offering new insights into the kinetics of cracking, and into the impact of several parameters on the different steps of cracking. A better understanding of the different cracking mechanisms is another output of this study. From the comparisons between different steel grades exposed to H2S environments with or without applied load allows, different cracking modes can be clearly distinguished: HIC vs. SWC (Step Wise Cracking), and SSC vs. SOHIC (Stress Oriented Hydrogen lnduced Cracking)
Khidour, Lhoussaine. "Dégradation par oxydation catalytique, en milieu aqueux, d'effluents industriels soufrés volatils : étude de leur devenir dans des conditions atmosphériques simulées." Université Joseph Fourier (Grenoble ; 1971-2015), 1994. http://www.theses.fr/1994GRE10061.
Azizi, Mohamed. "Étude de l’oxydation du sulfure d’hydrogène par le chlore en phase aqueuse. Détermination des constantes cinétiques et développement d’un logiciel de simulation de lavage chimique de H2S en milieu alcalin." Rennes, Ecole nationale supérieure de chimie, 2014. http://www.theses.fr/2014ENCR0018.
This Ph. D is an investigation on the optimization of hydrogen sulfide treatment processes in order to the fight against air pollution. Hydrogen sulfide is generally considered an undesirable toxic pollutant for its strong odor of rotten eggs. At higher concentration, it is responsible for corrosion which leads to progressive deterioration of pipes. Currently, the most used technique is chemical absorption with a sodium hypochlorite solution. The development of chemical scrubbing towers treating H2S requires precise knowledge of the kinetics of involved chemical reactions. The first part of this work was to develop a software simulation of a chemical scrubbing tower H2S in alkaline solutions without sodium hypochlorite. Numerical simulations were conducted to understand the impact of various parameters on mass transfer step of hydrogen sulfide at operating parameters near to industrial conditions. The results of the developed approach showed the need to add a chemical oxidant in order to enhance the mass transfer between gas and liquid phases. The second part of the Ph. D consisted firstly to characterize a gas-liquid reactor which it had been mechanically agitated by a Rushton turbine. Thus, the coefficients of local transfer which has a liquid side (kL) and gas (kG) H2S and the interfacial area (ao), were determined. In a second step, the study showed us the kinetic constants for the oxidation of H2S by ClOH/ClO-. Finally, the kinetics oxidation of the anion bisulfide (HS-) by ClOH had been investigated. Experiments between competing reagents had been established in order to identify the kinetic constant oxidation at basic pH. The founded results make a small library on the kinetics of hydrogen sulfide oxidation by chlorine. They can help industrial world to the scaling-up of scrubbing towers of chlore alkaline
Salesse, Alain. "Contribution à l'étude de la passivation par anodisation en milieu sulfuré non aqueux de semiconducteurs III/V : application à la passivation des antimoniures GaSb et structures à base de GaSb." Montpellier 2, 1995. http://www.theses.fr/1995MON20224.
Lacombe, Marielle. "Méthodes électrochimiques pour l'analyse in situ de composés bioactifs en milieu océanique." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/119/.
The implementation of in situ autonomous observatories for biogeochemical studies in the open ocean water column and in deep-sea chemosynthetic environments is crucial for the understanding of these ecosystems. We focussed this study on silicate and sulphide, two key compounds of the marine food chain. A voltammetric method for sulphide measurements on silver electrode is presented, and a new method for quantitative determination based on the solubility difference between silver chloride and silver sulphide is proposed. A completely reagentless method for silicate measurements is developed using molybdate and protons produced during molybdenum oxidation. These analytical developments allowed us to validate a submersible potentiostat, first step toward a new sensor for in situ measurements. A Drake Passage water masses analysis is also performed using data collected during the Drake ANTIII/3 oceanographic cruise in 2006
SALA, BEATRICE. "Contribution a l'etude de la corrosion du titane, de ses alliages et de certains aciers inoxydables en milieu aqueux, a haute temperature et sous pression." Orléans, 1987. http://www.theses.fr/1987ORLE2048.
Maurer, Olivier. "Étude de la distribution des espèces soufrées et de la formation de l'hydrogène sulfuré dans les stockages de gaz naturel en aquifère." Phd thesis, Ecole Nationale des Ponts et Chaussées, 1992. http://pastel.archives-ouvertes.fr/pastel-00569430.
Tchoumou, Martin. "Hydrometallurgie du cuivre en milieu chlorure : attaques de minerais dosages polarographiques des solutions resultant de l'attaque et depot cathodique du cuivre." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13154.