Dissertations / Theses on the topic 'Métaux lourds et métaux de transition'
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Ben, Maamar Sami. "Élaboration de matériaux moléculaires à partir d'unités calixaréniques." Phd thesis, Université Claude Bernard - Lyon I, 2008. http://tel.archives-ouvertes.fr/tel-00341104.
Full textMellah, Besma. "Interactions entre cations métalliques et dérivés des oxacalix[4]arènes." Université Louis Pasteur (Strasbourg) (1971-2008), 2006. https://publication-theses.unistra.fr/public/theses_doctorat/2006/MELLAH_Besma_2006.pdf.
Full textThe objective of this work was to establish the binding properties of oxacalix[4]arene derivatives with different numbers of the oxa bridges, functional groups (ketones, pyridine, ester, amide and methoxy) and conformations. Their interactions with alkali and alkaline-earth, heavy and transition metal cations have been evaluated according to different approaches: (i) extraction of corresponding picrates from an aqueous phase into dichloromethane; (ii) determination of the thermodynamic parameters of complexation in methanol and/or acetonitrile by UV-spectrophotometry and microcalorimetry; (iii) determination of the stoichiometry of the complexes by ESI-MS; (iv) 1H-NMR titrations allowing to localize the metal ions in the ligand cavity. In a first part dealing on homooxacalix[4]arenes, selectivities for Na+, K+, Ca2+, Pb2+ and Mn2+ of ketones derivatives was shown. The presence of oxa bridge in these derivatives increases their efficiency while decreasing their selectivity with respect to related calixarenes. The pyridine derivative prefers transition and heavy metal cations, in agreement with the presence of the soft nitrogen atoms. In the second part, dioxacalix[4]arene ester and secondary amide derivatives were shown to be less effective than tertiary amide counterparts but to present high selectivities for Li+, Ba2+, Zn2+ and Hg2+. A third part devoted to the octahomotetraoxacalix[4]arene tetramethoxy shows that the 1:1 metal complexes formed are generally more stable than those of calixarenes, suggesting the participation of the oxygen atoms of the bridge in the complexation. Selectivity for Cs+, Ba2+, Cu2+ and Hg2+ were noted
Bonnefille, Eric. "Des germylènes aux germynes : synthèse et réactivité de ces analogues lourds des carbènes et des alcynes." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/80/.
Full textThe metalla-alcynes of group 14 –M=C- (M = Si, Ge, Sn) is a new function of organometallic chemistry, this function appears extremely promising both in terms of fundamental applied. Indeed, if the study of a new link carbon presents a clear fundamental interest, these derivatives appear especially promising for their many potential applications: organometallic precursor polymer, new ligands for transition metals chemistry, catalysis. . . No germa-alcyne has been isolated to date and a single instance, short-lived, has been characterized within our team by trapping reaction. Our strategy to prepare for such molecules involves the photochemical decomposition of a diazogermylene. In this work our effort focused more specifically on the search for substituents that could stabilize these species by electronic and steric effects. We used a new ligand (Ar = 2-diisopropylaminoethyl-4,6-ditertbutylphényl) which has the interest to add to the effect steric effect of a coordinated electronic intramolecular N> Ge. The photochemical decomposition led well then, after starting nitrogen at germa-alcyne Ar-Ge?C-SiMe3. This is the 2nd germa-alcyne known, it has been characterized by its reaction with water and tertiobutanol. The diazogermylène also offers an original and rich chemistry; it is possible to achieve particularly germathione, germa-selenone and germa-tellurone> = Ge Y (Y = S, Se, Te) surprisingly stable condition and whose monomer there are few examples
Zheng, Yuanyuan. "Modélisation et simulation à l’échelle nanométrique de l’effet de température, de pression et des polluants sur l’argile hydratée de type montmorillonite." Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10158/document.
Full textMonte Carlo and Molecular Dynamic simulation methods have been performed to study hydrated Wyoming-type montmorillonite, a naturally occurring swelling clay, including different monovalent or divalent counterions. Simulations have been also performed to investigate the swelling and shrinking behaviour of montmorillonite under the influence of water content, temperature and different counterions. We found a general phenomenon of hysteresis during both the hydrate/dehydrate and the warming/cooling processes. The quantities of counterions together with their solvation characteristics and their attraction capacities have an important influence on the swelling and shrinking behaviours of this clay. Moreover, investigations on the diffusion behaviours of water and counterions in the interlayer space of montmorillonite show the effect of hydrated degree and different existing cations especially the pollutants on the diffusion of water, as well as the effect of temperature on the diffusion of interlayer particles. The agreement of our simulation results on the clay containing some common cations such as Li+, Na+, K+ and Ca2+, with available experiment and preceding theoretical works, permitted us to extend our study to the clay with heavy metal ions, such as Rb+, Cs+, Ni2+, Zn2+ and Pb2+, some of which have never been studied.Finally, detailed studies on the shrinking behaviours of hydrated montmorillonite under pressure allowed us to shed light on the rigidity of this clay affected by the hydrated degree, where we found a phase transition phenomenon in hydrated montmorillonite with the phase transition pressure less than 1GPa. According to our calculations the bulk modulus reaches extremely high values at modest pressures of ~20 GPa. It would open a route to a new family of ultra-incompressible materials of clay composition. Such materials, and their superior mechanical properties and possibly low cost, could be practically attractive for a number of uses
Lloret, Bruno. "Cristallochimie et comportement physique (kondo, valence intermédiaire ou mixte, fermions lourds) de nouveaux composés ternaires dans les systèmes cérium, europium ou uranium, métaux de transition (3d,4d,5d) silicium ou germanium." Bordeaux 1, 1988. http://www.theses.fr/1988BOR10532.
Full textBareille, Cédric. "Effets d'une brisure de symétrie sur les stuctures électroniques d'URu2Si2 et de KTaO3." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00937625.
Full textJaber, Maguy. "Synthèse et caractérisation de phyllosilicates 2:1 de type saponite et d'organophyllosilicates 2:1." Mulhouse, 2003. http://www.theses.fr/2003MULH0723.
Full textThe present work deals with the hydrothermal synthesis of 2:1 phyllosilicate with a saponite type-like structure in fluoride medium and the soft and direct synthesis of 2:1 organophyllosilicates. The effects of the different parameters controlling the presence of aluminum in the tetrahedral sheet were studied. Saponite was only obtained for a low substitution rate of aluminum in fluoride and acidic medium, whereas high substitution rate in basic medium has been provided a saponite-like structure. A proposition of a formation mechanism is given. In basic medium, the 2:1 phyllosilicate structure is induced by the hydrotalcite formation and in acidic medium by the polysilicic acid formation. Different kind of hybrid lamellar materials were also prepared : a lamellar organoaluminosilicate having no phyllosilicate structure, a lamellar organomagnesoaluminosilicate having, as inorganic parent, a 2:1 phyllosilicate structure. A formation mechanism was proposed. These materials are very interesting in the chelating of heavy metal cations
Juraszek, Jean. "Dommages induits par irradiation aux ions lourds dans des matériaux magnétiques : multicouches metalliques Fe/Tb et grenat isolant Y 3Fe 5O 1 2." Rouen, 2000. http://www.theses.fr/2000ROUES016.
Full textBert, Valérie. "Tolérance aux métaux lourds et accumulation chez Arabidopsis halleri (Brassicaceae)." Lille 1, 2000. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2000/50376-2000-69.pdf.
Full textToutes ces populations sont tolerantes et accumulatrices de quantites tres importantes de zn et de cd. La tolerance a ces metaux ainsi que leurs accumulations semblent etre des proprietes constitutives de l'espece. L'etude de la descendance (f2) d'un croisement interspecifique, (a. Halleri tolerant-hyperaccumulateur) x (a. Petraea non-tolerant-non-accumulateur), a montre que la tolerance au zn semblait etre sous le controle d'un gene majeur tandis que la variation du degre de tolerance au zn semblait etre sous le controle de genes modificateurs. La tolerance au zn n'est pas due aux metallothioneines. Elles pourraient, cependant, contribuer a modifier le degre de tolerance au zn et ainsi intervenir au titre de modificateur. Les resultats preliminaires obtenus sur la tolerance et l'accumulation du cd en relation avec la tolerance et l'accumulation du zn suggerent l'independance des mecanismes lies au cd et au zn
Ledrich, Marie-Laure. "Mise en évidence et étude comparative des protéines de transport de fer et d'autres métaux chez Ralstonia eutropha CH34 et souches dérivées." Metz, 2001. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2001/Ledrich.Marie_Laure.SMZ0132.pdf.
Full textRastolnia eutropha CH34, formerly Alcaligenes eutrophus CH34, was initially isolated from a decantation tank by Houba et al. , in 1976. Studies on this strain revealed at least 11 heavy metals resistances, carryied by two megaplasmids : pMOL28 et pMOL30, which translate a bacteria adaptation system to highly polluted soils. Firstly, the czc resistance system, carried by pMOL30, is based on cadmium, zinc and cobalt efflux. Secondly, Rastolnia eutropha CH34 had developed a highly specific system for iron transport, based on siderophore affinity, because this element is weakly biodisponible in environment. These two mechanisms, the first one facultative, and the second one inducible but constitutive, seem to be associated. The knowledge of these two mechanism is very important to understand the way of heavy metal depollution processes. The main purpose of this study was to identify the proteins of czc system and the siderophore-iron receptor. Two Rastolnia eutropha CH34 derivates were used as references : Rastolnia eutropha 1153 (which overexpresses siderophores) and Rastolnia eutropha 104 which is plasmids-free). A 45kDa outer membrane protein was identified, by electrophoresis techniques. It seems to be the siderophore-iron receptor
Larmet, Hélène. "Mobilisation et transfert de Zn, Cd, Cu et des colloïdes bactériens dans les bassins d’infiltration d’eaux pluviales : Influence des conditions hydrodynamiques." Université Joseph Fourier (Grenoble), 2007. http://www.theses.fr/2007GRE10037.
Full textSurfaces impermeability is enhanced by urbanisation, leading to the increase of volumes and polluting loads of stormwater runoff. Consequently, in the East of Lyon, stormwater are discharged in infiltration basins. Contaminants are supposed to accumulate at their surface layer, but little is known concerning their long term fate. In particular, bacteria are liable to facilitate metallic transfer through the vadose zone to the aquifer. This study aims at identifying mechanisms and conditions of mobilisation and transfer of three heavy metals (Zn, Cd, Cu) and bacterial colloids, in realistic conditions. Copper mobilisation from the polluted layer depends on soil solution transfer and hydrodynamical conditions, while other elements seem to be dissolved from a common organo-mineral matrix: amounts released are similar whatever the experimental conditions. Finally, bacteria contents depend neither on initial water content, nor on flow conditions. Amounts of Cu and colloids potentially released from the polluted layer are substantive. The unpolluted layer retains a fraction of dissolved and colloidal matter, but preferential flows and colloidal transport, depending on hydrodynamical conditions, favours metallic transfer. Consequently, a scheduled scrapping of the polluted layer and an improvement of the retention of particles before they enter basins are advised
Eshghi, Malayeri Behrouz. "Décontamination des sols contenant des métaux lourds à l'aide de plantes et de microorganismes." Nancy 1, 1995. http://docnum.univ-lorraine.fr/public/SCD_T_1995_0353_ESHGHI_MALAYERI.pdf.
Full textLara-Cazenave, Marie-Belen. "Spéciation de métaux lourds (cadmium, cuivre, plomb et zinc) dans des eaux de ruissellement." Pau, 1994. http://www.theses.fr/1994PAUU3010.
Full textEtienne, Mathieu. "Approches analytique et électrochimique du comportement en solution de silices mésoporeuses organiquement modifiées." Nancy 1, 2001. http://www.theses.fr/2001NAN10192.
Full textLesaint, Cedric. "Synthèse de silices mesoporeuses organisées : Etude d'un mécanisme de formation et fonctionnalisation par des groupements organiques." Mulhouse, 2005. http://www.theses.fr/2005MULH0822.
Full textThis PhD work deals with the synthesis of organized mesoporous silica (OMS) with controlled porosity and hydrophobia. In a first part, the formation of MSU type materials was studied by in situ techniques (fluorescence, DLS and NMR). The mechanism of formation, proposed from the obtained results, is based on interactions between silica polymers and surfactant molecules, initial micelles playing only a role of reservoir of surfactants. In a second part, various OMS were functionalized either by post-synthesis grafting, or by a direct route with two types of organic groups (n-propyl and 3-mercaptopropyl) in order to study the influence of the geometry and the pore size on the functionalization process. Materials functionalized by the direct route show a more significant grafting rate and a more homogeneous distribution of the organic functions to the detriment of a lower organization of the porous network by comparison with post synthesis grafted materials. The capacity of fixation of Hg species was studied on the OMS functionalized with thiol groups
Asmeta, Ahmed-Fayez. "Comportement hydrodynamique et ohysico-chimique des métaux lourds dans les sols." Reims, 1987. http://www.theses.fr/1987REIMS014.
Full textDerouiche, Abdelali. "Contribution à l'étude des propriétés structurales et thermodynamiques des métaux alcalins et des métaux de transition, liquides." Metz, 1988. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1988/Derouiche.Abdelali.SMZ8821.pdf.
Full textThis dissertation, which deals with some structural and thermodynamic aspects of liquid alkali and transition metals, is divided into 3 parts. First, we analyse the role of reference systems, at zero order, on the determination of the structural and thermodynamic properties of these liquid metals. In the second part, we take into account the free electron gas as well as the d-electrons, in the transition metals, calculating the pair interionic potential which allows to obtain the structure factor. In the third part, we bind together the previous view-points to determine the free energy owing to the Gibbs-Bogoliubov inequality. Then, we deduce various thermodynamic quantities. Although the outline of the structure factor curves is usually predicted by the hard sphere (HS) interactions, it has been anticipated that the one component plasma (OCP) model can also describe the structure of some liquid metals. Thus, we have compared the experiments to the results of thermodynamic properties for alkali and transition metals, from HS and OCP models. We have also given an analytic form for the OCP structure factor reproducting the first peak correctly. The determination of the pair potential of simple liquid metals as well as of transition metals has been carried out. The Wills and Harrison formulation has been used in which the hybridisation effects are treated by moving some electrons from the d-band to the band of conduction. The feature of the pair potential of transition metals is to depend on the volume as well as the ion arrangement. To ontain the thermodynamic properties we minimise the free energy relatively to a parameter of the reference system. Thus, we have shown that the OCP model is better than the HS model, for alkalis. Besides, it is found that the Ichimaru-Utsumi dielectric function provides the lowest energy, for alkalis. Lastly, the results of the free energy and others thermodynamic properties are in good agreement with experiments, for liquid metals under consideration
Liu, Xianfeng. "Transfert des solutions métalliques dans les argiles saturées et impact sur les microstructures." Ecole centrale de Nantes, 2010. http://www.theses.fr/2010ECDN0031.
Full textThis work aims to study the effects of heavy metals cations (lead, copper and zinc) on the permeability, compressibility and microstructure of two clays (Kaolinite Speswhite and Wyoming bentonite) used as barrier materials under unfavourable conditions (high heavy metal concentration and low clay dry density) from macro and micro points of view. Firstly, the retention and dsorption properties of heavy metals by the two clays were studied by conducting batch sorption and desorption tests. Then, hydromechanical and physicomechanical behavious changes of the clays induced by the presence of heavy metals were shown under two different loading conditions. The first one is the permeation with different heavy metal solutions in the recoonstituted clays specimens saturated with deionized water. The second one consists of carrying out conventional oedometric tests on the reconstituted clays specimens initially saturated with different heavy metals solutions. In order to investigate the microstructure evolution of the clays caused by heavy metals and clay interaction, microstructural analyses were carried out on specimen in their initial state and after having been subjected to two different loadings: permeation and consolidation. Different microstructural techniques were employed, such as Environmental Scanning Electron Microscopy observation (ESEM), mercury intrusion porosimatry and surface area determined by liquid nitrogen adsorption-desorption, and thermal analysis. These macro and micro analysis showned the mechanical, hydraulic, microstructural behaviour of contaminated reconstituted clays, expressed by the measurements of parameters such a permeability, compressibility and retardation effect of heavy metal transport in clays. It appears that the behaviour changes of these contaminated clays are directly related to their corresponding microstructural changes induced by heavy metals and clays interactions
Al-Shukry, Raad. "Détermination de la pollution des sédiments d'un cours d'eau par des métaux lourds (Cu, Zn, Pb, Ni) : étude de leur accumulation et de leur relargage : rôle du pH, de la température et de la composition du sédiment." Limoges, 1993. http://www.theses.fr/1993LIMO0209.
Full textFerlin, Nadège. "Synthèse et propriétés de tensioactifs chelatants des métaux dérivés de glucose." Amiens, 2008. http://www.theses.fr/2008AMIE0106.
Full textHeavy metals pollution of water and soils is a problem for the environment and public health. One possibility to treat the contaminated areas is flotation. This process evacuates the pollutants in a foam formed by the addition of surfactants and air bubbling. Sugar-based chelating surfactants seem to be good candidats for a use. The compounds were obtained with good yields through a simple, fast and not expensive synthesis. The surfactants are all derivates from alkylglucosides obtained by micro-waves assisted synthesis. The oxidation of the primary alcohol to carboxylic acid permitted the addition of a chelating function by coupling reactions. Another possibility to form chelating surfactants was the substitution of the primary alcohol by a more nucleophilic function. Interfacial properties were determined by the maximum bubble pressure method. The critical micellar concentration of the surfactants goes from 13 to 36 mmol. L-1 and the compounds showed good properties for flotation. Flotation tests were performed at laboratory scale with different metal salts (Fe3+, Cr3+, Cu2+, Zn2+, Cd2+, Ni2+, As3+) and the metal concentrations were measured by ICP. Ca2+ extraction was also studied for use in detergency. The extracting capacity of the compounds depends of the structure of the surfactant, but also of the involved metal. In fact, a good foaming capacity in presence of metal salts is a very important factor. Depending of the chelating function, selective or general estractive chelating surfactants were obtained
Rougier, Frédéric. "Etudes des effets du zinc et du cuivre sur la fonction immune du poisson Zèbre (Brachydanio rero) (activité cytotoxique, phagocytose, résistance à Listeria monocytogènes : avantages et limites de ce modèle animal en immunotoxicologie aquatique." Limoges, 1993. http://www.theses.fr/1993LIMO0200.
Full textBlaudez, Damien. "Etude des interactions entre métaux lourds et champignons ectomycorhiziens : capacités d'accumulation, mécanismes d'absorption, et influence sur la physiologie de plantes hôtes." Nancy 1, 2000. http://www.theses.fr/2000NAN10097.
Full textMoudilou, Emmanuel. "Cinétiques et mécanismes de relargage des métaux lourds présents en traces dans les matrices cimentaires." Orléans, 2000. http://www.theses.fr/2000ORLE2052.
Full textGabelle, Cédric. "Étude de la contamination des sédiments par les métaux dans les canaux et rivières du Nord de la France." Lille 1, 2006. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2006/50376_2006_90.pdf.
Full textArchambeau, Alexis. "Cyclopropènes et métaux de transition synthèse de carbocycles et d'hétérocycles." Paris 6, 2013. http://www.theses.fr/2013PA066584.
Full textThe investigation of the reactivity of substituted cyclopropenes in several transition metal-catalyzed reactions involving either the addition on the double bond or the ring-opening into vinyl metal carbenes is presented. It has been shown that conjugated cyclopropenyl amides, esters and ketones can undergo enantioselective transfer hydrogenation, catalyzed by chiral ruthenium(II) complexes, leading to tetrasubstituted cyclopropanes with excellent enantiomeric purity. The transfer hydrogenation occurs with high chemoselectivity in favour of the cyclopropene double bond due to the ring strain. The rhodium(II) vinyl carbenoids resulting from the ring-opening of 3,3 dimethyl-cyclopropenyl carbinols have been successfully involved in intramolecular C-H insertions. This method allows access to a variety of carbocycles, oxygen heterocycles and bicyclic compounds in excellent yields and with high diastereoselectivities. The investigation of the reactivity of aryl cyclopropenyl carbinyl esters had led to the discovery of a new rearrangement, catalyzed by rhodium(II) complexes, leading to methylenecyclopropanes bearing an enol ester with chirality transfer. These latter compounds are valuable intermediates to access a variety of substituted and functionalized arylcyclopropanes
Maurel, Brigitte. "Fixation et mobilité des métaux lourds en milieu réducteur : Application à la gestion d'un bassin recevant des apports d'origine industrielle." ENSMP, 2000. http://www.theses.fr/2000ENMP0973.
Full textCloquet, Christophe. "Géochimie élémentaire et isotopique des métaux lourds : applications environnementales en tissu urbain et industriel." Vandoeuvre-les-Nancy, INPL, 2005. http://docnum.univ-lorraine.fr/public/INPL_T_2005_CLOQUET_C.pdf.
Full textIn 2001, an urban waste incinerator equipped for power recuperation (UVE) was installed in the city of Metz. Samples of the UVE effluents were collected to characterize the mineralogical, chemical and isotopic behaviour of the metals and their environmental impact. Excess concentrations of the heavy metals as well as heavy Cd and Zn isotopes enrichment are found in the Trémie 2 ashes. Such an enrichment can be explained by kinetic fractionation during the condensation process. Elemental and isotopic analyses of epiphytic lichens, collected from Metz and the surrounding area before the UVE, were used to construct an urban atmospheric fall-out map and the evolution 2 years after. The application of Cd isotopes to an area polluted by a smelter demonstrates the potential of Cd isotopes for tracing environmental pollutants
Muñoz, Juarez Sergio Rolando. "Mesure et modélisation du potentiel de migration de métaux lourds lors de leur transfert dans le réservoir hydrogéochimique sous-jacent de la ville de Guatemala." Paris 11, 1995. http://www.theses.fr/1995PA112166.
Full textAchelhi, Karima. "Organo-apatites et nanocomposites zircone-hydroxyapatite pour le piégeage des métaux." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00827451.
Full textMouabad, Abdelfattah. "Toxicité comportementale et physiologique (filtration, respiration) des métaux lourds (Cu, Zn, Hg, Cd et Pb) chez la moule d'eau douce Dreissena polymorpha pallas : proposition d'un protocole d'essai pour l'évaluation de la toxicité par la réponse comportementale de Dreissena." Metz, 1991. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1991/Mouabad.Abdelfattah.SMZ918.pdf.
Full textThe study deals with the effetcts of subletal concentrations of heavy metals (Cu, Zn, Hg, Cd, Pb) on the pumping behaviour and physiological functions (filtration rate, oxygen consumption) of the freshwater mussel Dreissena polymorpha. A preliminary study, carried out to screen the letal effects, showed that the LC 50-96 h is 0,191mg/l for Cu, 0,420 mg/l for Hg and above 14 mg/l for Cd. Zn has no letal effect in a 96 h exposure. In a 24h exposure, subletal concentrations of metals induce deep changes in the pumping activity of Dreissena. Pumping flow becomes intermittence and valve closure in enhanced. The effects are concentration dependent. Metals can be classified in a decreasing order of toxicity as following : Hg, Cu, Cd, Pb, Zn. In view of its good sensitivity, the behavioural response of Dreissena is proposed as a tool for the screening of toxicity in freshwaters. The detection limits set for metals are (in mg/l) : 0, 010 for Hg, 0,015 for Cu, 0,100 for Cd, 0,200 for Zn and 0,400 for Pb. In exposures of 48 h and 1 week, metals significantly reduce the filtration rate of Dreissena. Order of toxicity is the same as for behaviour. The oxygen consumption study showed that it is increased by Zn and reduced by Cu and Hg. No effect was obtained with Cd and Pb. Integration of the physiological effects was undertaken for Cd (0,005 to 0,045 mg/l) and Cu (0,004 to 0,044 mg/l) in a 4 weeks exposure. Results show that the Scope for Growth in not impaired by Cd whereas Cu reduces it. The usefulness of the studied physiological functions as criteria for the chronic toxicity testing is discussed
Villar, Arribi Pablo. "Fermions lourds et métaux de Hund dans les supraconducteurs à base de fer." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY070/document.
Full textMaterials where the electrons responsible for the low-energy properties experience strong correlations are today very investigated in search of emerging new phases with surprising and/or useful properties. Iron-based superconductors (IBSC) are now considered in this class of compounds. Using the many-body techniques necessary for the theoretical treatment of these correlations (slave-spin mean field theory - SSMFT- and dynamical mean field theory - DMFT- in conjunction with density functional theory, DFT), in this thesis I address several properties of IBSC.First I analyze the very hole-doped compounds in the IBSC family, that show experimentally some behaviors typical of the so-called “heavy fermions”, compounds typically of rare earth or actinides, where extremely correlated electrons coexist with others less correlated. In particular I focus on the specific heat and the thermoelectric power and show how these properties can be understood in the recently developed paradigm of “Hund’s metals”. Indeed the intra-atomic exchange (the “Hund’s coupling”) is responsible for these materials of transition metal elements showing heavy-fermionic physics. I show also that typical heavy-fermionic features of the excitation spectrum, known as Van Hove singularities are well captured by our modelization within DFT+SSMFT. I then use DMFT in a model in order to study the direct impact of the Van Hove singularities on the strength of correlations.In a second part I show how FeSe, the presently most studied IBSC, is also in a Hund’s metal phase, but it is brought to the frontier of this phase by pressure. This frontier is connected to an enhancement of the electronic compressibility which correlates positively then with the enhancement of superconductivity found in experiments. I perform an analogous study on the record holder for the highest critical superconducting temperature, the monolayer FeSe where I also find an enhanced compressibility. This supports the recent proposal that the frontier of a Hund's metal favors high-temperature superconductivity.Finally I study the nature of magnetism in another family of IBSC, the iron-germanides. I explore different possible magnetic orders with DFT simulations and study their competition (which can in principle favor superconductivity) in several compounds where different chemical substitutions are applied to the parent compound YFe2Ge2. I also study the effect of chemical pressure on this compound
Taghavi, Safieh. "Un mégaplasmide de résistance aux métaux lourds d'alcaligènes eutrophus: analyse génétique et fonctionnelle." Doctoral thesis, Universite Libre de Bruxelles, 1996. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212387.
Full textBernard, Hélène. "Bioindication des métaux lourds (Plomb, mercure, cadmium et thallium) par les basidiomycètes sauvages." Bordeaux 2, 1996. http://www.theses.fr/1996BOR2P026.
Full textCherifi, Kamel. "Synthèse d'oligopeptides soufrés et étude de leur complexation par des cations métalliques." Lille 1, 1990. http://www.theses.fr/1990LIL10025.
Full textStandaert, Alain R. "Synthèse de ligands nouveaux pour les métaux de transition." Doctoral thesis, Universite Libre de Bruxelles, 1989. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213216.
Full textMétian, Marc. "Écotoxicologie des métaux chez les pectinidés : bioaccumulation, variabilité zoogéographique et évaluation des risques sanitaires." La Rochelle, 2007. http://www.theses.fr/2007LAROS198.
Full textMetal bioaccumulation is very important in Pectinidae. This work studied this phenomenon in 3 species of this bivalve’s family (Chlamys varia, Comptopallium radula & Pecten maximus) in order to better understand biological processes which govern it. This study combining datas from the field and measurements in laboratory investigated 3 levels of biological levels (individuals, organs and cells). The zoogeographical variability of the bioaccumulation capacities as well as a consumer risk assessment were also investigated in this work in reason of the various source of the studied species (C. Radula - tropical zone and the 2 other species - temperate zone) and the important consumption of pectinids tissues. The field approach indicated, amongst other things, the biomonitoring capacities of C. Radula and P. Maximus during Ag contamination. In addition, the metal levels in the tropical species was comparable with other pectinids excepting the very low Zn concentration in their kidneys because of their presumed low contents in granules. The laboratory approach aimed at defining the kinetic parameters of the bioaccumulation in the organisms via sea water, food and the sediment using the techniques of radiotraçage (γ emitters). In addition to the comprehension of accumulation and the retention of metals in simple conditions, this approach allowed indicated considerable role of the particulate pathway on the global bioaccumulation using a model. Finally, both complementary approaches together highlighted the important roles of kidneys and the digestive gland in the accumulation and the storage of the metals. But also, subcellular detoxification mechanisms set up by Pectinidae
Verret, Frédéric Gilles. "Caractérisation physiologique et moléculaire d'un transporteur de type cadmium-ATPase chez Arabidopsis thaliana." Aix-Marseille 2, 2005. http://www.theses.fr/2005AIX22021.
Full textWeissenhorn, Ingrid. "Les mycorhizes à arbuscules dans des sols pollués par des métaux lourds : tolérance aux métaux et rôle dans leur transfert aux plantes." Nancy 1, 1994. http://www.theses.fr/1994NAN10009.
Full textBrackx, Gwennhaël. "Approche multidisciplinaire pour la détection de métaux lourds en environnements aquatiques." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC004/document.
Full textFreshwater management is a major problem all over the world. Anthropogenic activities related to industry, agriculture and human settlements are the main sources of water pollution. In order to makes policies for pollution prevention, rehabilitation of aquatic environments or waste water recycling, it is necessary to acquire massive data on water quality. Current contaminant monitoring methods have high costs and low frequency of measurement due to the incompatibility with field deployment. These two major brakes do not make it possible to monitor pollutant and especially heavy metal concentrations in aquatic environments at relevant spatial and temporal scales. Several international organizations, including the United Nations, have therefore recommended the development of new and better analytical methods.We propose here a technique for measuring heavy metal contaminants based on Surface Enhanced Raman Spectroscopy (SERS), which would allow a large scale deployment in the field.SERS has many advantages for environmental analysis including sensitivity, specificity, speed of measurement, adaptability to complex matrix and the moderate cost of portable instrument. We will therefore detail the construction of the SERS probe dedicated to the quantification of the target heavy metal ion Zn2+, which is a geochemical marker of anthropogenic contamination, as well as the data processing necessary for the establishment of quantification. Then, we will examine the robustness of the method of quantification with respect to the sources of variability that will inevitably be encountered in natural waters, when used directly in the field
Domain, Francis. "Rôles des ferrédoxines de Synechocystis : mise en évidence et analyse de l'interaction : ferrédoxine VII-glutaredoxine II." Paris 11, 2005. http://www.theses.fr/2005PA112088.
Full textBacteria to the human being, ferredoxins (fed), proteins with iron-sulphur centre, are essential for the poorly known mechanism of transfer of electrons to the cellular redox metabolism, which we analyze in model cyanobacteria Synechocystis. This bacteria presents the following assets: - A small sequenced genome easy to manipulate - 9 genes fed which belong to almost totality of the classification based on the nature of their iron-sulfur centre - Two redox metabolisms generating of oxidative stress (breathing and photosynthesis) in the same compartment Thanks to gene deletions and phenotypical corresponding mutant's analysis, I showed that 4 ferredoxins are essential in cellular viability and that FedVII (not essential) intervenes in the tolerance of oxidative stress and heavy metals. Thanks to the double-hybrid system, I showed that FedVII interacts with 2 key proteins of the metabolism redox: Ferredoxin Thioredoxin Reductase and a glutaredoxin. It is the first time that an interaction Fed-Grx is disclosed. The directed mutagenesis made me identify, in each protein partner, the essential amino acids for these interactions. The corresponding specific mutations (interactions' loss) were introduced in Synechocystis. They reproduce partly the deletion of FedVII and these partners (FtrC and Grx2). In another part of my thesis, I analyzed the role of the lexA gene in cyanobacteria. By a transcriptomic approach, we showed that contrary to E. Coli, lexA does not control genes of the "S. O. S" (DNA repair). On the other hand, LexA is essential for the tolerance in the deficiency of carbon (Domain et al. , 2004)
Ghaieb, Jalel. "Elimination de métaux en solution par l'ozone : études cinétiques et transfert de matière." Toulouse, INPT, 1990. http://www.theses.fr/1990INPT019G.
Full textBarreteau, Cyrille. "Morphologie et énérgetique des surfaces vicinales de métaux de transition." Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00006882.
Full textelecrtonique et de potentiels empiriques. Une attention particuliere
est dediee a l'etude de la stabilite des surfaces vicinales vis a vis du facettage.
MONTES, RENDON ARTURO. "Préparation et propriétés catalytiques de métaux de transition sur mordenité." Poitiers, 1987. http://www.theses.fr/1987POIT2037.
Full textLEGMA, JEAN BOUKARI. "Cristallogénèse et photo-conversion de diséléniures de métaux de transition." Aix-Marseille 1, 1989. http://www.theses.fr/1989AIX11252.
Full textMesboua, Nouara. "Caractérisation de surfaces solides par adsorption : physisorption sur solides lamellaires et métaux, chimisorption d'oxygène sur métaux de transition." Vandoeuvre-les-Nancy, INPL, 1987. http://www.theses.fr/1987NAN10215.
Full textBouain, Nadia. "Etude des interactions entre métaux lourds et phosphate chez les plantes : aspects physiologiques et moléculaires." Thesis, Montpellier, SupAgro, 2016. http://www.theses.fr/2016NSAM0008.
Full textPlants require a variety of elements for their basic biological functions. Interestingly, Transport, assimilation and utilization of these nutrients are not independent of another. However, the biological significance, molecular and genetic bases of these dependencies are not well understood. We use the over-accumulation of inorganic phosphate (Pi) in plants under zinc (Zn) deficiency as an example to dissect a fundamentally and agronomically important Pi-Zn interdependency in Lettuce, rice and Arabidopsis plants. We described the physiological and molecular basis of the interaction between Pi and Zn homeostasis. In Lettuce, we revealed a contrasting behavior between the two lettuce varieties in terms of the coregulation of Pi and Zn homeostasis. In rice, our data reveal coordination between pathways involved in Fe transport and PiZn signaling, which involves the OsPHO1; 1. In Arabidopsis, we discovred a new mecanism that plants use to gate defense and growth process in Pi-Zn dependant manner
Coste, Servane. "Nouveaux thiophosphates de métaux de transition et d'alcalins : synthèses, structures, propriétés et exfoliation dans des solvants organiques." Nantes, 2002. http://www.theses.fr/2002NANT2040.
Full textDelmail, David. "Contribution de Myriophyllum alterniflorum et de son périphyton à la biosurveillance de la qualité des eaux face aux métaux lourds." Limoges, 2011. http://www.theses.fr/2011LIMO330C.
Full textUsing plants to biomonitor stream water quality in ecotoxicological surveys is a promising way. Myriophyllum alterniflorum is a poor-known aquatic macrophyte which biomarker potential is evaluated during cadmium and copper pollutions. The responses of its periphyton communities are also studied. After establishment of the in vitro culture of M. Alterniflorum, a protocol is defined for clone reintroduction. It allows comparative laboratory and field studies to assess the toxicity of heavy metals on M. Alterniflorum and its antioxidant responses. A new anatomical feature reducing the water stress appears in leaves, as a double endodermis. Moreover, four copper-specific biomarkers are evidenced in in situ conditions: ascorbate peroxidase, glucose-6-phosphate dehydrogenase, vitamin E and malondialdehyde. Using the occurrence of groups with specific ecological affinities, the periphyton biodiversity brings highlights about cadmium and copper contamination. Furthermore, in a metacommunity approach, the dynamics of the most representative taxa underlines the importance of the plant-substrate restoration to ensure the continued survival in disturbed environments. Macrophyte and periphyton appear as essential in biomonitoring, and they are useful for the management of natural habitats and for public health policies according to the European and national water directives
Gagnepain, Bruno. "Spéciation des métaux lourds dans les résidus solides d'usines d'incinération d'ordures ménagères et contribution à l'interprétation des processus de vaporisation." Perpignan, 1998. http://www.theses.fr/1998PERP0321.
Full textPark, Jae Beom. "Etude physico-chimique de la chimisorption de vapeur de dérives du cadmium, du zinc et du plomb sur divers substrats minéraux." Mulhouse, 2003. http://www.theses.fr/2003MULH0734.
Full textThe goal of our study is to increase knowledge relating to the adsorption of metal chlorides on various substrates. The experiments carried out clearly the influence of the nature of the adsorbent on the phenomenon of adsorption of the metal chloride vapours. We noted that the best effectiveness, with regard to the capture of chloride of gas metals at a temperature of 850ʿC, is obtained with silica (for CdCl2 and PbCl2) and alumina (for ZnCl2). The tests of leaching were carried out. A simulation carried out under the Fluent computer code of the evaporation of metal chlorides, allowed to calibrate our installation. An interpretation basing on traditional laws of adsorption was developed. A kinetic model of reactor with against current made it possible to determine the rate constants for the various combinations of metal chloride and adsorbent