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Wang, Yuheng. "Etude cristallochimique de l'immobilisation de l'arsenic par les (hydr)oxydes de fer dans les environnements anoxiques". Paris 6, 2007. http://www.theses.fr/2007PA066384.
Pełny tekst źródłaWu, Yingxin. "Surfactant-Assisted Zerovalent Iron Dechlorination Of Polychlorinated Biphenyl In Contaminated Sediment". Electronic Thesis or Diss., Université de Lorraine, 2016. http://www.theses.fr/2016LORR0066.
Pełny tekst źródłaSoil and sediment contamination by polychlorinated biphenyls (PCBs) is a global health and environmental concern, since PCBs are toxic and recalcitrant. The aim of this thesis is to find a remediation process to PCBs contaminated sediments by using zerovalent iron (ZVI). To begin the studies on remediation, a survey was conducted on sites contaminated by e-waste recycling activities in south China. PCBs contamination was not as severe as previously, whereas the co-existence of PCBs and heavy metals increases the difficulty of remediation. Afterwards, the feasibility PCBs degradation by ZVI in aqueous solutions was investigated. Results confirmed the stepwise dechlorination of PCBs by ZVI and the major pathway with congener specifity and regiospecifity. The relative importance of the influential factors to ZVI degradation of PCBs was in the order of surfactants > humic acid > pH > Ni2+. Sediment decontamination was studied by 1) washing with an aqueous solution of surfactant followed by ZVI dechlorination of PCBs and 2) direct mixing with ZVI and surfactant solution. The second approach gave promising results for remediation
Al-Sid-Cheikh, Maya. "Impact des oxydes de fer naturels et des nanoparticules manufacturées sur la dynamique des éléments traces dans les sols de zones humides". Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S144.
Pełny tekst źródłaNanoscience is based on changes in particle properties when their diameter is below 100 nm (ie nanoparticles, NPs). Considering the increasing use of such NPs and their discharge into the environment, the assessment of their risks to human health and the environment is a major issue. Underneath the protection of waters and soils, the surface water assessment quality is particularly important, especially in wetlands, where the toxic metals dynamic (e.g. As, Pb, Ni, Cr , Hg) is complex and depends on the redox conditions of the environment. As magnetite (nano-Fe3O4), a natural or manufactured NP, is known for its significant adsorption capacity with heavy metals, their interactions in riparian wetlands with trace metals (TMs) remain critical concerning their direct of indirect impact on trace metals (TMs) mobility. The objective of this thesis was to study the role of manufactured nano-Fe3O4 (~ 10nm) and natural iron oxides on the TMs dynamics in wetland surface waters and soils. Therefore, in a first part considering natural colloidal precipitates from reoxidation products from riparian areas (subject to redox oscillations), a spatial distribution of elements was performed using nanoSIMS isotope mapping (i.e. 75As-, 56Fe16O-, sulfur (32S-) and organic matter (12C14N-), while the sulfur speciation was evaluated X-ray adsorption at K edge of the sulfur (S) (XANES). These analyzes allowed to highlight the interactions between natural iron oxides, natural organic matter (NOM) and a toxic metalloid, As. Our results suggest, with a statistical colocalization of nanoSIMS images, the existence of two interaction types: (1) 12C14N-, 32S-, 56Fe16O- and 75As-, and (2) 12C14N-, 32S- and 75As-. The coexistence of the oxidized and reduced forms of S, confirmed by the XANES analyses might be attributed to the slow oxidation kinetic of MON. Thus, this first part shows that in addition to the known interactions between MON, iron oxides and As, a possible direct interaction between As and NOM through sulfur functional groups (e.g. thiols) are also possible in oxidized environment. In a second part, the effect of nano-Fe3O4 (~ 10 nm) on trace elements (TEs) and colloids mobility in the organomineral horizon of a natural wetland soil was assessed using soil columns. Our results show that the nanoparticles coating influences the mobility of NOM and TMs. Indeed, the TMs mobility increases in presence of naked nano-Fe3O4, suggesting associations where NOM stabilizes the nanoparticles and increase the nanoparticles and associated TMs mobility. This mechanism seems less possible with coated nano-Fe3O4 where MON blocks the coating adsorption sites and therefore the adsorption of metals
Wille, Guillaume. "Propriétés thermophysiques et structurales du fer et des oxydes de fer liquides". Orléans, 2002. http://www.theses.fr/2002ORLE2022.
Pełny tekst źródłaZaidi, Mourad. "Mouillabilité de surfaces hétérogènes fer-oxydes par le plomb et l'étain". Châtenay-Malabry, Ecole centrale de Paris, 2008. http://www.theses.fr/2008ECAP1094.
Pełny tekst źródłaWetting phenomenon takes place in several processes among which continuous galvanizing of steel sheet for car bodies. In this process, the steel sheet is immersed in a zinc bath in order to cover it with a protective zinc layer. But before that, the cold rolled steel sheet is annealed in a reducing atmosphere in order to eliminate the cold working and the superficial iron oxides improving thereby the galvanizing reactions. New steels, called advanced high strength steels, have been developed in order to improve vehicle safety without increasing their weight and therefore fuel consumption. These steels contain high amounts of oxidable alloying elements that segregate during the annealing to the surface where they form oxides particles that are not wetted by liquid zinc. Therefore it seems important to understand the wetting by liquid metals of heterogeneous surfaces composed by metallic iron and oxides. For this purpose we have build a dispensed drop apparatus allowing the annealing of the substrate separately of the liquid and the in situ study of the spreading of metallic droplet at very short time using a high speed camera. In our experiments we have used different iron – silcon alloys and an industrial steel leading to surface coverage lying from 0 to 100%. We have chosen two liquid metals. Lead to investigate the non reactive wetting and tin to investigate the reactive wetting. Wetting
Dumeignil, Franck Payen Edmond Grimblot Jean. "Catalyse et environnement". Villeneuve d'Ascq : Université des sciences et technologies de Lille, 2007. https://iris.univ-lille1.fr/dspace/handle/1908/177.
Pełny tekst źródłaSynthèse des travaux en français et curriculum vitae. Recueil de publications en anglais non reproduit dans la version électronique. N° d'ordre (Lille 1) : 501. Titre provenant de la page de titre du document numérisé. Bibliogr. 5 p. Liste des publications et des communications.
Belin, Thomas. "Interface externe et propriétés structurales d'un solide nanométrique : cas de nanocristaux de γ-Fe2O3 , adsorption d'eau et transition de phase γ-α". Dijon, 2002. http://www.theses.fr/2002DIJOS052.
Pełny tekst źródłaDelepine, Jean. "Caractérisation de la liaison fer-oxygène dans des oxydes de fer à valence mixte par des méthodes spectrométriques". Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37597018t.
Pełny tekst źródłaTarablsi, Bassam. "Elaboration de nanocomposites photopolymères à base d’oxyde de fer et d’argile". Mulhouse, 2008. https://www.learning-center.uha.fr/opac/resource/elaboration-de-nanocomposites-photopolymeres-a-base-doxyde-de-fer-et-dargile/BUS4168193.
Pełny tekst źródłaIn this work, nanocomposites of photopolymer-oxide and photopolymer-oxide-MMT (oxide: nanoparticles of yFe2O3, MMT: montmorillonite) were prepared by photochemical procedure. Conceming the first on (photopolymer-oxide), the maghemite nanoparticles were synthesized according to the process described by Massart. The compatibility of these particles with the polymeric matrix was obtained by immobilization of MPDMS at their surface using a thermic procedure. Conceming the second one, the mixture of different nanofillers (nanofillers mixture yFe2O3-MMT) were prepared by a new method based on the ion exchange reaction and different chemical and thermal treatments. The incorporation of both nanofillers in the diacrylate photopolymeric matrix was studied and optimized. A kinetic study of the photopolymerization reaction in presence of both nanofillers was also performed by FTIR spectroscopy. The addition of both nanofillers did not effect significantly the polymerization kinetics in thin films (10µm) at nanofillers concentration up to 2 wt%. It was found that nanocomposites had a came photopolymerization rates in comparison with pure diacrylate. The experimental results showed that photopolymer-oxide-MMT nanocomposite can improve by 66% the mechanical properties (E')
Bentahar, Yassine. "Caractérisation physico-chimique des argiles marocaines : application à l’adsorption de l'arsenic et des colorants cationiques en solution aqueuse". Thesis, Université Côte d'Azur (ComUE), 2016. http://www.theses.fr/2016AZUR4081/document.
Pełny tekst źródłaToday drinking water resources are greatly reduced due to population increase accompanied by high industrialization and intensive agricultural development. Releases of varying micropollutants (pesticides, dyes, phenols ...) in the environment are increasing. These pollutants, toxic and poorly degradable, are usually the source of many harmful health effects. They also directly affect the balance of ecosystems following the deterioration of the quality of various environmental medium (soil, water, air). Hence the concern to develop methods that work to preserve water resources against pollution by treating polluted sources. The application of natural and abundant adsorbents like clay in the water treatment is a legitimate way to preserve the water capital. That is why my research is articulated around the physicochemical characterization of a series of natural clays sampled in the northern region of Morocco. Several techniques have been sought: XRD, XRF, FTIR, TGA, The BET-N2 specific surface area, electrophoresis. Furthermore the determination of some physicochemical properties such as CEC and TOC. This allowed us to establish a database with the different properties of these materials. This database may be sought to guide the use of these materials according to their nature. In a second step, we studied the adsorption of arsenic and organic contaminants (methylene blue and methylene violet) by clays. The kinetics of equilibrium adsorbent / adsorbate is an essential step to optimize the conditions for determination of adsorption isotherms
Ducos, Kilian. "Effet de la limitation en fer selon le mode de vie et étude des mécanismes moléculaires de l'acquisition du fer chez Marinobacter hydrocarbonoclasticus". Electronic Thesis or Diss., Pau, 2022. http://www.theses.fr/2022PAUU3069.
Pełny tekst źródłaIron is an essential element for most living organisms because it is present in prosthetic groups of many enzymes, especially those of the respiratory chain. Marine microorganisms must extract iron directly from seawater, where its concentration is particularly low (less than 1 nmol.L-1) and where it is mostly bound to organic molecules. The iron is consequently poorly available for the growth of microorganisms and therefore, it controls indirectly essential microbial activities for the biogeochemical cycles of major elements such as carbon and nitrogen for example. The use of siderophores, molecules with high affinity for iron, has been recognized for several years as an effective way for marine bacteria to recover poorly available iron. However, only few studies have focused on the effect of iron limitation on the physiology of the cell according to its mode of growth: planktonic, where the cells are free or in biofilm, where the cells adhere to a substrate.To determine the importance of iron on the lifestyle of bacteria, we used as a model Marinobacter hydrocarbonoclasticus SP17, a heterotrophic marine bacterium that grows as a planktonic population when the carbon source is soluble, like acetate, or as a biofilm when the carbon source is insoluble, such as alkanes or triglycerides. We observed that planktonic growth requires more iron than biofilm growth and that alkane growth requires more iron than triglyceride growth. This variability according to the growth mode and the carbon source can be explained by differences in iron requirements and/or in the efficiency of iron acquisition.To measure the importance of siderophore production and biofilm formation, genetic and chemical analyses techniques were used. A standard of the siderophore produced by M. hydrocarbonoclasticus, the petrobactin, was obtained. It allowed to quantify by mass spectrometry the petrobactin in the extracellular medium under different growth conditions. The results obtained showed an overproduction of the siderophore at low iron concentration, suggesting a more important role in this condition. To confirm the petrobactin involvement and to understand what are the other mechanisms involved in iron acquisition, mutants of the biosynthesis pathway of petrobactin and of the potential transport of Fe3+ ions were constructed. Although the study of the phenotypes of all simple and double mutants constructed could not be completed during this work, the results obtained suggest the presence of two main iron acquisition pathways, one petrobactin dependent, and another dependent on the periplasmic protein FbpA. The double mutation seems to be lethal, but the study of the conditional mutant constructed will allow confirmation of these results and will give a better understanding of the iron acquisition pathways involved in the different growth modes
Hugounenq, Pierre. "Toxicologie des nanoparticules d'oxyde de fer : impact des modifications de surface". Paris 6, 2012. http://www.theses.fr/2012PA066643.
Pełny tekst źródłaPotential hazard of nanoparticles is a key society challenge, particularly because the relation between exposure, dose and toxicity of nanoparticles is far to be clearly established. In particular, magnetic iron oxide nanoparticles are of great interest since they are already used in nanomedecine as commercial contrast agent for MRI or as heating agents in magnetic hyperthermia. In this thesis, we investigate the relation between surface properties of nanoparticles and their interactions with human cells. We have synthesized maghemite nanoparticles in sizes ranging from 6 to 50nm, with a spherical or flower-like shape and possessing various coatings, which control their surface charge densities and their aggregation state in biological media. The nanoparticles physical properties have been measured with a panel of techniques allowing us to fully characterize their size, specific surface area and crystallinity. The influence of these parameters on their toxicity has been investigated on adenocarcinomic human alveolar epithelial cells. Cellular viability tests and oxidative stress measurements show that the nanoparticles express a low toxicity. Only the positive nanoparticles show a significant cytotoxicity on the cells. The role of the coating and aggregation on the nanoparticles-cell interaction has been highlighted, showing thus that a deep characterization of the nanoparticles is necessary prior to any toxicity testing. The nanoflowers show not only a low toxicity but also exceptional properties as MRI contrast agents and magnetic hyperthermia vectors. Their use in biomedical application is therefore very promising
Ejjenne, Ahmed. "Comportement électrochimique des oxydes de fer αFeOOH, αFe2O3, γFe2O3 et Fe3O4 et aspect cinétique de leur dissolution". Lyon 1, 1987. http://www.theses.fr/1987LYO19013.
Pełny tekst źródłaLe, Deit Laëtitia. "Les dépôts stratifiés dans la région de Valles Marineris (Mars) : composition minéralogique et morphologie". Nantes, 2008. http://www.theses.fr/2008NANT2081.
Pełny tekst źródłaThe Martian surface locally displays bright and friable layered deposits preferentially located in the equatorial regions of the planet. Their origin has been debated for more than 30 years. Layered deposits are accumulated in the canyons of Valles Marineris and on the surrounding plateaus during the Hesperian epoch. One of these canyons, East Candor Chasma, is partially filled with these layered deposits. Their morphological and stratigraphic analysis show that they consist of fine-grained indurated and easily erodible material that is consistent with sandstone, tuffs and consolidated dust. The upper layers of the series may have been deposited with ice during a period of high obliquity of the planet. An aerial depositional environment accounts for these observations. However, the possibility of a lacustrine deposition can not be ruled out. Sulfate and ferric oxides have been detected in these layered deposits. The analysis of data from the OMEGA imaging spectrometer enabled to map precisely ferric oxides in the canyon. They may have precipitated within layered deposits in response to groundwater table variations under changing chemical conditions. Stratified deposits located on the plateau correspond to a series of material accumulated in an aerial environment (dust or ashes possibly mixed with ice) which has undergone an aqueous alteration at the surface or subsurface during the Hesperian epoch, and eolian and fluvial erosion. Thus, the region of Valles Marineris records traces of aqueous activity throughout its history
Mathieu, François. "Etude des transformations sous haute pression des oxydes de fer submicroniques à structure spinelle : analyse structurale des mécanismes réactionnels". Toulouse 3, 1990. http://www.theses.fr/1990TOU30043.
Pełny tekst źródłaMoog, Iona. "Sur des oxydes de cérium contenant du fer nanostructurés et de morphologies contrôlées". Phd thesis, Université Sciences et Technologies - Bordeaux I, 2012. http://tel.archives-ouvertes.fr/tel-00806578.
Pełny tekst źródłaEl, Abdouni Hamid. "Evolution de la texture critallographique des oxydes de fer en cours de réduction". Metz, 1986. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1986/El_Abdouni.Hamid.SMZ8613.pdf.
Pełny tekst źródłaAbdouni, Hamid el. "Evolution de la texture cristallographique des oxydes de fer en cours de réduction". Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37595286c.
Pełny tekst źródłaEL, ABDOUNI HAMID HEIZMANN JEAN-JULIEN. "EVOLUTION DE LA TEXTURE CRISTALLOGRAPHIQUE DES OXYDES DE FER EN COURS DE REDUCTION /". [S.l.] : [s.n.], 1986. ftp://ftp.scd.univ-metz.fr/pub/Theses/1986/El_Abdouni.Hamid.SMZ8613.pdf.
Pełny tekst źródłaBaaziz, Walid. "Synthèse et caractérisation des nanoparticules spinelles et coeur-coquille à base d’oxyde de fer et de cobalt". Strasbourg, 2011. https://publication-theses.unistra.fr/restreint/theses_doctorat/2011/BAAZIZ_Walid_2011.pdf.
Pełny tekst źródłaThe objectives of this thesis were to synthesize and study the structural and magnetic properties of nanoparticles (NPs) of iron oxide and cobalt ferrite with different sizes, morphology and compositions, including core-shell structures. The chosen synthesis method was the thermal decomposition of an iron stearate complex in a high boiling solvent in presence of surfactants. In a first part centered on iron oxide NPs, the experimental conditions of synthesis were optimized to obtain spherical iron oxide NPs with a mean size in the range 5 -28 nm. We have studied the evolution of the composition and magnetic properties of NPs as a function of their size and of the nature of the atmosphere of synthesis. Using the same method of synthesis, we succeeded in controlling the morphology and composition of NPs: NPs with a cubic morphology were obtained with mean sizes in the range 13-30 nm with a homogeneous Fe3-xO4 composition and with a core-shell FeO@Fe3-xO4 composition displaying exchange bias-properties. The second part was centered on the synthesis of cobalt ferrite and mixed core-shell NPs : NPs with homogeneous composition CoFe2O4 and with core-shell structure such as CoxFe1-x@CoFe2O4 and Fe3-xO4@CoO have been synthesized. Exchange bias properties were clearly evidenced in the core-shell NPs. Finally, we managed to control the synthesis of spherical NPs of iron oxide on the surface or inside of carbon nanotubes (CNTS) and cobalt-based NPs with cubic morphology were synthesized inside CNTs. We have shown that the CNTs act as a "nanoreactor"
Duchateau, Anne. "Réduction par électrolyse de nanoparticules d’oxydes de fer en milieu alcalin à 110°C". Paris 6, 2013. http://www.theses.fr/2013PA066533.
Pełny tekst źródłaIron oxides play an important role in steel industry as precursors of iron. The current iron production process in blast furnaces is responsible for 3 to 5% of the world CO2 rejections. Reducing the iron oxides in suspension by electrolysis in strongly alkaline medium (18 M) at 110°C is a promising way to lower the CO2 rejections while improving steel production efficiency, that has been studied for years. The aim of this work is the determination of the most reliable oxide concerning metallic iron production and a more accurate comprehension of the electrolytic reduction mechanisms in order optimize the production process. The experiments are carried out on iron oxides nanoparticles (hematite, goethite, lepidocrocite, akaganeite, magnetite) synthesized according to well known methods which allow us to obtain perfectly defined objects concerning the structure, size and morphology. Hematite is the only oxide to be stable in the 18 M sodium hydroxide solution for a long lasting period. The ageing of the other iron oxides nanoparticles in hot concentrated sodium hydroxide solution led to the formation of sodium ferrite NaFeO2, the transformation duration depending on the starting iron oxide. NaFeO2 precipitation competes with the reduction reaction and lead to less reproducibility and/or less good performances. Indeed, the dissolved ferric species are the intermediates of the reduction by electrolysis mechanism and ions consumption by NaFeO2 precipitation is obviously harmful to metallic iron production. The most reliable oxides are commercial Hematite particles because of the good yields and the important metallic iron weights obtained with reproducibility
Zegeye, Asfaw. "Formation et stabilité des hydroxysels Fe(II-III) de type rouille verte en cultures bactériennes". Nancy 1, 2006. http://www.theses.fr/2006NAN12510.
Pełny tekst źródłaZegeye, Asfaw. "Formation et stabilité des hydroxysels Fe(II-III) de type rouille verte en cultures bactériennes". Nancy 1, 2006. http://www.theses.fr/2006NAN10233.
Pełny tekst źródłaMaillot, Fabien. "Structure locale des nano-oxyhydroxydes de fer(III) de type ferrihydrite et schwertmannite". Paris 6, 2011. http://www.theses.fr/2011PA066349.
Pełny tekst źródłaOna-Nguema, Georges. "Biogenèse d'hydroxysels mixtes Fe(II-III) de type rouille verte en culture de Shewanella putrefaciens". Nancy 1, 2003. http://www.theses.fr/2003NAN11259.
Pełny tekst źródłaBenjelloun, Driss. "Conduction électrique dans Fe₂O₃α et Cr₂O₃ oxydes de structure corindon déformée". Bordeaux 1, 1985. http://www.theses.fr/1985BOR10571.
Pełny tekst źródłaCarpentier, Jenny. "Synthèse et caractérisation d'oxydes mixtes à base de cuivre, de cobalt et de fer dérivés de précurseurs de type hydrotalcite destinés à l'oxydation totale du toluène". Littoral, 2003. http://www.theses.fr/2003DUNK0098.
Pełny tekst źródłaIn this work, catalytic performances of copper, cobalt and iron based mixed oxides derived hydrotalcite precursors have been studied in toluene oxidation reaction. Dry and calcined solids have been characterized by several physicochemical techniques as X-ray diffraction, differential thermal analysis, thermogravimetric analysis, infrared spectroscopy, X-ray photoelectron spectroscopy and specific areas. Then, the samples calcined at 500ʿC have been tested in toluene oxidation reaction. For CuxCo2-xFe1HT samples as x = 0 and x = 0. 5, pure hydrotalcite phase has been formed whereas the increase of copper quantity in the sample tends to form malachite phase. The thermal treatment at 500ʿC of the samples leads to formation of spinel phases as Co3O4, CoFe2O4, CuFe2O4, CuxCoyO4 and to the formation of CuO for x = 1. For toluene oxidation reaction, all the samples have been shown totally selective in CO2 and H2O. Ternary oxides have been shown more active than binary ones and the CuxCo2-xFe1HT samples as x = 0. 5 and x = 1 have been too more active than Co3O4. The presence of spinel phases as CuFe2O4 and/or CuxCoyO4 seems to be beneficial for catalytic activity. Moreover, the presence of copper and cobalt species in different oxidation states due to reductive effect of the catalytic test leads to the creation of ion pairs as Cu+-Co3+, Cu2+-Co2+, Co2+-Co3+ and Cu+-Cu2+ very active in this oxidation reaction
Trolard, Fabienne. "Physicochimie des cuirasses latéritiques : domaines de stabilité des oxydes et hydroxydes de fer et d'aluminium". Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13268.
Pełny tekst źródłaJordan, Norbert. "Influence de l'acide silicique sur la rétention du sélénium (IV) sur des oxydes de fer". Nice, 2008. http://www.theses.fr/2008NICE4013.
Pełny tekst źródłaDuring this work, the influence of silicic acid on the retention of selenium (IV) onto goethite, hematite and magnetite has been studied, aiming to increase our knowledge on the involved mechanisms. After several kind of sorption experiments, we showed that silicic acid was sorbed onto the surface on the three studied materials, involving a modification of the global surface reactivity of the solids. The sorption edges were fit with the 2 pK surface complexation model by considering the formation of two monodentate surface complex, namely =FeH3SiO4 and =FeH2SiO4. During the saturation experiments, where increasing initial concentrations of silicic acid were added, we observed the probable presence of a changing in the mechanisms during the adsorption : a first step where a monolayer of sorbed silicic acid was formed, followed by a second step where the formation of silicates compounds ir the surface precipitation of a coating of silica could occur. Those phenomena were observed by XPS and RAMAN spectroscopies. Then, by adsorption experiments in anoxic conditions where the two studied elements were added simultaneouslyt and sequentially in the suspensions, we observed a competition phenomenon between selenium (IV) and silicic acid for the surface sites of goethite, hematite and magnetite. XPS results showed the absence of reduction of selenium (IV) in our experimental conditions. Finally, we also examined the interaction between a layer of magnetite formed electrochemically on a iron foil and selen,ium (IV) in anoxic conditions. The reduction of selenium (IV) into elementary selenium was observed by XPS and RAMAN measurements
Trolard, Fabienne. "Physicochimie des cuirasses latéritiques domaines de stabilité des oxydes et hydroxydes de fer et d'aluminium /". Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb376016635.
Pełny tekst źródłaRossano, Stéphanie. "Environnement du fer ferreux dans les verres silicates. Developpements theoriques et approches spectroscopiques". Paris 7, 1998. http://www.theses.fr/1998PA077281.
Pełny tekst źródłaBergeron, Benjamin. "Synthèse de nanoparticules à structure coeur-coquille d'oxyde de fer et d'or". Master's thesis, Université Laval, 2014. http://hdl.handle.net/20.500.11794/25564.
Pełny tekst źródłaGénin, Ghislain. "Contribution au développement d'un nouveau contacteur gaz-solide destiné à la mise en oeuvre de réactifs pulvérulents". Vandoeuvre-les-Nancy, INPL, 1999. http://www.theses.fr/1999INPL020N.
Pełny tekst źródłaGreffie, Catherine. "Contribution à la connaissance du comportement de l'or en milieu latéritique : étude expérimentale des mécanismes de coprécipitation de l'or et des oxy-hydroxydes de fer". Aix-Marseille 3, 1994. http://www.theses.fr/1994AIX30022.
Pełny tekst źródłaLafon, Sandra Gaudichet Annie. "Les oxydes de fer dans l'aérosol désertique en relation avec ses propriétés optiques caractérisation physico-chimique de poussières minérales générées en soufflerie /". Créteil : Université de Paris-Val-de-Marne, 2004. http://doxa.scd.univ-paris12.fr:80/theses/th0215155.pdf.
Pełny tekst źródłaRoullier, Victor. "Micelles de nanocristaux fluorescentes et magnétiques comme sondes pour la bio-imagerie". Rennes 1, 2009. http://www.theses.fr/2009REN1S159.
Pełny tekst źródłaWe report the synthesis of both fluorescent and magnetic nanoprobes for labelling and tracking individual biomolecules by bio-imaging (fluorescence microscopy, MRI, …). Both fluorescent semi-conductors (quantum dots) and magnetic (iron oxide) nanocristals were co-encapsulated by using amphiphiles which self-organise into stable micelles with a diameter of 18 to 30 nm. These amphiphiles (PEGylated gallates) present 3 undecanoyl chains, a 34 units polyethylene glycol (PEG) and a terminal functional group such as : OH, NH₂, COOH or N₃. The magnetic properties of the micelles permit to guide them collectively under magnetic field. Furthermore, effect on the contrast in MRI was quantified. Finally, recognition groups such as biotin (targeting avidin derivatives) or tris-NTA (targeting polyhistidine tag by complexation with Ni²⁺) were introduced. We achieved a specific and selective labelling of transmembranar proteins onto HeLa cells, using tris-NTA
Mayant, Claire. "Étude des propriétés de rétention et de transport de la magnétite dans un état compacté". Nantes, 2009. http://www.theses.fr/2009NANT2010.
Pełny tekst źródłaIn France, the concept of deep geological disposal of high-level radioactive waste includes the steel canister with the nuclear glass surrounded by an iron over pack for safety purposes. In contact with groundwater the iron container is expected to corrode into corrosion products including magnetite. The retention experiments (titrations and adsorptions) were carried out with a commercial magnetite powder, in both dispersed and compacted state to emphasize the role of compaction onto sorption sites densities and to better simulate site conditions. First, potentiometric titrations of dispersed magnetite give a minimal site density of 2. 5-3. 0 / nm2 and the titration of compacted magnetite (magnetite powder which is compressed at 120 bars in a percolation cell) provided a site density of 1. 06 / nm2 in the pH range 8-11 and 4. 74 / nm2 in the pH range pH 3-8. This indicates that commercial magnetite does not loose surface sites after his compaction. On the dispersed magnetite (30 g / L) at pH 8, the silicic acid adsorption takes place with 2. 2 atoms per nm2, and the selenium (IV) adsorption takes place with 0. 49 atoms per nm2. On the compacted magnetite, the silicic acid give a similar site density with a low silicic acid concentration, but the site density with respect to Si is 4. 5 / nm2 with a high silicic acid concentration, indicating a probable saturation of the sites. A competitive adsorption is observed between selenium (IV) and silicic acid on both dispersed and compacted magnetite. Indeed, silicic acid seems to adsorb on the sites which were initially occupied by selenium and thus causes his desorption
Bouchahoua, Jamel-Eddine. "Réduction de l'oxyde de fer liquide par le carbone solide". Châtenay-Malabry, Ecole centrale de Paris, 1994. http://www.theses.fr/1994ECAP0355.
Pełny tekst źródłaDANIEL, PHILIPPE. "Oxydes de cuivre et de fer a structures en couches : elaboration, structure, proprietes electriques et magnetiques". Caen, 1995. http://www.theses.fr/1995CAEN2019.
Pełny tekst źródłaSoufyani, Mohammed. "Aérogels et matériaux SiO2-oxyde d'un métal de transition obtenus par la voie sol-gel". Montpellier 2, 1992. http://www.theses.fr/1992MON20295.
Pełny tekst źródłaPachoud, Elise. "Etude d'oxydes de fer à structures perovskite et delafossite". Caen, 2011. http://www.theses.fr/2011CAEN2030.
Pełny tekst źródłaThis thesis work is set in the dynamic context of research and study of multiferroic materials. It concerns the synthesis and the physicochemical characterization of iron-based oxides of two different families. BiFeO3 crystallizes in the perovskite structure and belongs to the type-I multiferroics, where ferroelectricity and magnetism have different origins. The substitution of bismuth by strontium Bi1-xSrxFeO3- induce a transition from R3c to Pm-3m at x=0. 20. Although the long range structure of Bi0. 764Sr0. 236FeO2. 94 is described in the space group Pm-3m, recurrent phenomena are observed at short range, coming from the ordering of oxygen vacancies or of Bi/Sr distribution, thus explaining the discrepancy of results in the literature devoted to this system. The delafossite system CuBO2 (B=Fe,Cr R-3m) is classified in the type-II multiferroics, where the polarization is induced by the magnetic structure of the compound. The substitution with rhodium CuFe1-xRhxO2 stabilizes a ferroelectric phase for a wide substitution range, 0. 02x0. 15, while vanadium in CuFe0. 5V0. 5O2 induces a spin-glass behaviour, which affects also the electrical properties. A parallel study in CuCr1-xMxO2 (M=Al,Ga,Rh,Sc) reveals differences in the observed properties ; although rhodium make the transition temperature decreases while keeping the initial physical properties, gallium induces a second magnetic transition. These substitutions, in both systems, modify drastically the properties, and contribute to the understanding of the observed phenomena
Lafon, Sandra. "Les oxydes de fer dans l'aérosol désertique en relation avec ses propriétés optiques : caractérisation physico-chimique de poussières minérales générées en soufflerie". Paris 12, 2004. https://athena.u-pec.fr/primo-explore/search?query=any,exact,990002151550204611&vid=upec.
Pełny tekst źródłaDirect radiative impacts of desert aerosols emitted bv wind erosion on arid and semi arid zones are a major source of uncertainties of climate models. In this work, aerosols have been generated in wind-tuimel from soils of source region (Niger. Tunisia and Chine). These samples have been characterized with original methods, regarding properties controlling scattering and absorption properties of solar and telluric radiation: size distribution. Particle rnorphologv, mineralogical and chemical compositions, content and status of iron oxides. These data allow evaluation of dust optical properties and assessment of a relationship between iron oxides and absorption in the visible spectrum. In the near future, this should make it possible to include a parameterization ofoptical properties in dust emission models
Ourry, Laurence. "Relation structure-propriétés de matériaux hybrides magnétiques polymère-ferrites spinelles". Paris 7, 2014. http://www.theses.fr/2014PA077193.
Pełny tekst źródłaI worked on the design of magnetic hybrid materiais consisting of polyrner and spinel metal oxide nanoparticles focusing on (1) the synthesis of nanopowders of magnetic oxides by the polyol process and controlling the magnetic properties (timing of the size of NPs, use of exchange-bias to increase the magnetic thermal stability. . . ), (ii) the control of the dispersion of NPs as a function of their surface state and suitable functionalizations and ( iii) their processing in thermbplastic polymer matrices or preformed biopolymers. These points are discussed through three topics: (a) the synthesis of Fe304@CoO core-shell nanoparticles exhibiting exchange bias, and their further functionalization by polystyrene (PS) and polymethylmethacrylate (PMMA) brushes", we compared the magnetic properties (dipolar interactions and exchange bias) of these hybrids with those of bare nanoparticles. (b) The ynthesis of cobalt ferrite nanoparticles, CoFe204, and surface functionalization with two ligands. These nanoparticles were then introduced into a polyvinylidene fluoride matrix (PVDF) to design magnetoelectric films. (c) The design of magnetothermosensitives gels and films for drug delivery and tissue engineering. This project is an expioratory study to a project developed by IBM, Almaden Center, USA, where I reallzed a 3 month internship dunng my PhD involvement
Labaiz, Mohamed. "Étude de l'oxydation et du frottement à haute température d'aciers au carbone et inoxydable : comparaison avec quelques matériaux céramiques". Compiègne, 1993. http://www.theses.fr/1993COMPD606.
Pełny tekst źródłaDjerrab, Abderrezak. "Etude des propriétés magnétiques du remplissage de sites préhistoriques pléistocènes : contribution à l'étude stratigraphique, archéozoologique de leurs dépôts et à leur évolution géochimique post-dépositionnelle". Perpignan, 2001. http://www.theses.fr/2001PERP0426.
Pełny tekst źródłaThe magnetic susceptibility of prehistoric site deposits is governed by a number of physico-chemical factors, responsible for important oscillations of the magnetic signal. High magnetic parameters generally correspond to clayey levels formed during humid climatic periods, as well as hearths and levels containing minerals of volcanic origin. The alteration and disaggregation of bedrock and of rocks close to the sites can also contribute to increasing the values of the magnetic parameters. The size of the magnetic grains is a result of several physico-chemical process which can intervene during sediment deposition or during any stage of the infilling's history. Iron oxides of detrital origin (unchanged since their deposit) characterise sedimentary deposits contemporary with a cold dry climate, which are wind deposits, or formed by the alteration (disaggregation) of the limestone wall and of scree. The majority of the magnetic grains are PD sized and are characterised by a strong coercive force (hematite and goethite). On the other hand, secondary iron oxides (issued from the transformation of primary iron oxides) are dominated by smaller sized grains (SP). They are saturated in a magnetic field less than 200mT, which suggests the dominance of magnetite and maghemite. Furthermore, use of hysteresis cycle parameters helped to determine the size of magnetic grains samples in different prehistoric sites. This method also allowed to evaluate the concentration of ferro-magnetic minerals and of antiferro-magnetic, paramagnetic and diamagnetic minerals, and their contribution to the overall value of the magnetic susceptibility
Feder, Fréderic. "Dynamique des processus d'oxydo-réduction dans les sols hydromorphes : Monitoring in situ de la solution du sol et des phases solides ferrifères". Aix-Marseille 3, 2001. http://www.theses.fr/2001AIX30036.
Pełny tekst źródłaIron in soil plays a major role in biogeochemical cycles as electron and acceptor in oxydo-reduction reactions, the main source of energy for life. To study the pxydo-reduction dynamics in hydromophic soil, in situ reduced conditions must be preserved. At Fougères, Britanny, the piezo-metric level of the watertable was measured and the composition of the soil solution was monitored in situ with a multiparametric probe. A miniaturized Mössbauer spectrometer is used for the first time to study variations with depth and transformations with time of iron minerals. XRD, BEM and selective extraction (CB and DCB) techniques were performed on soil samples. Test of iron oxides solution thermodynamic equilibria are computed for specific field conditions with Equil (T) code
Espie, Gilles. "Oxydation de particules de fer dans un plasma d'arc Ar-H2 s'écoulant dans l'air : influence sur les propriétés du dépot". Limoges, 2000. http://www.theses.fr/2000LIMO0038.
Pełny tekst źródłaLadouceur, Isabelle. "Caractéristiques physico-chimiques du vieillissement des oxydes de fer biogéniques formés à la surface de différentes bactéries". Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/8994.
Pełny tekst źródłaWu, Yingxin. "Surfactant-Assisted Zerovalent Iron Dechlorination Of Polychlorinated Biphenyl In Contaminated Sediment". Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0066/document.
Pełny tekst źródłaSoil and sediment contamination by polychlorinated biphenyls (PCBs) is a global health and environmental concern, since PCBs are toxic and recalcitrant. The aim of this thesis is to find a remediation process to PCBs contaminated sediments by using zerovalent iron (ZVI). To begin the studies on remediation, a survey was conducted on sites contaminated by e-waste recycling activities in south China. PCBs contamination was not as severe as previously, whereas the co-existence of PCBs and heavy metals increases the difficulty of remediation. Afterwards, the feasibility PCBs degradation by ZVI in aqueous solutions was investigated. Results confirmed the stepwise dechlorination of PCBs by ZVI and the major pathway with congener specifity and regiospecifity. The relative importance of the influential factors to ZVI degradation of PCBs was in the order of surfactants > humic acid > pH > Ni2+. Sediment decontamination was studied by 1) washing with an aqueous solution of surfactant followed by ZVI dechlorination of PCBs and 2) direct mixing with ZVI and surfactant solution. The second approach gave promising results for remediation
Brendle, Eric. "Etude des propriétés de surface d'oxydes de fer (goethite, hématite) : influence de traitements thermiques". Mulhouse, 1997. http://www.theses.fr/1997MULH0467.
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