Tesi sul tema "Transport de l'eau"
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Bergin, Gaëtan. "Prévision de la solubilité des hydrocarbures dans l'eau en fonction de la température et de la pression". Clermont-Ferrand 2, 2002. http://www.theses.fr/2002CLF21335.
Boursiac, Yann. "Mécanismes de régulation du transport d'eau dans la racine d'Arabidopsis thaliana : effets d'un traitement par le sel et le péroxyde d'hydrogène sur la fonction des aquaporines". Montpellier 2, 2005. http://www.theses.fr/2005MON20194.
Water uptake by roots plays a central role in the regulation of plant water status. The root water permeability (root hydraulic conductivity; Lpr) is regulated by many environmental conditions such as drought or nutrient deficiency. At the molecular level, water channels named aquaporins contribute to a large part of the overall Lpr (> 70% in Arabidopsis thaliana). However, the mechanisms for aquaporin regulation in plants and their role in the modulation of Lpr by environmental stresses are still poorly understood. The aim of this thesis was to unravel novel molecular and cellular mechanisms of aquaporin regulation in the context of water transport modulation in the root of Arabidopsis. For this, Lpr regulation was studied in two distinct physiological situations, salt stress (NaCl) and exposure of roots to reactive oxygen species (ROS). Here we show that a salt treatment (100 mM NaCl) can inhibit Lpr by 35% in 40 min and by up to 70% after 3 h. Aquaporins expression was regulated in parallel to this at, at least, three levels : the abundance of transcripts and proteins and the subcellular localisation of the latter. Whereas these mechanisms may explain the long term (> 4 h) regulation of Lpr by salt, other types of regulation, by post-translational modifications for instance, might be involved in the early response (< 2 h) of the root. In another study, hydrogen peroxide (H2O2) and other ROS were identified as powerful inhibitors of Lpr by up to 80% in a few minutes. Unexpectedly, the action of ROS on the aquaporin activity was not mediated by a direct oxidation gating mechanism, but rather involved the activation of signalling pathways in which external calcium and protein kinases played an important role. From this and other works, we conclude that, as central molecules in the response of plants to environmental stresses, H2O2 and other ROS could be major regulators of Lpr. In conclusion, this work uncovered signalisation pathways and multiple levels for regulation of aquaporin expression which contribute to a chain of events from the perception of environmental stress to the molecular regulation of root water transport
Badamtchian, Chahram. "L'Eau, l'industrie et le transport fluvial dans les vallées de la Seine et de l'Oise". Paris 1, 1985. http://www.theses.fr/1985PA01A020.
Ngo, Van Viet. "Modélisation du transport de l'eau et des polluants dans les sols contaminés des friches industrielles". Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL101N/document.
Preferential flow and nonequilibrium transport are probably the most frustrating in terms of hampering accurate predictions of contaminant transport through the vadose zone. The mathematical description of preferential flow and nonequilibrium transport needs many parameters that are not measurable. Therefore, the inverse method is a promising way to estimate model parameters. The main objectives of this work are to (i) study the water flow using the uniform flow and dual-porosity models, tracer and contaminant transport using the uniform transport model and/or physical and chemical nonequilibrium transport models, (ii) investigate parameter estimability and correlations between different parameters, and (iii) optimize the hydraulic properties and solute transport parameters. The results concerning the water flow in the bare field lysimeter show that daily data contained much more information than hourly data, daily pressure heads contained more information than daily water contents; the correlations between different parameters hamper the optimization results strongly. Basing on the tracer concentrations in the leaching solution of the lysimeter, the first-order rate water transfer coefficient was not estimable since this parameter was highly correlated with the solute transfer coefficient. PAH concentrations in the leaching solution of the contaminated soil column under saturated and nonsaturated flow conditions show that when the degree of chemical nonequilibirum transport is high, the solute leaching of the nonsaturated column contained more information than those of the saturated column. In addition, the fraction of sites with instantaneous sorption and the linear adsorption distribution coefficient always showed a very strong correlation, they were impossible to optimize simultaneously
Marly, Xavier. "Transport d'un micro-organisme en milieu poreux saturé : cas d'un colloïde biologique : cryptosporidium parvum". Vandoeuvre-les-Nancy, INPL, 2001. http://docnum.univ-lorraine.fr/public/INPL_T_2001_MARLY_X.pdf.
Alboin, Clarisse. "Deux outils mathématiques pour modéliser l'écoulement et le transport de polluants dans un milieu poreux fracturé". Paris 9, 2000. https://portail.bu.dauphine.fr/fileviewer/index.php?doc=2000PA090024.
Rodrigues, Olivier. "Les aquaporines de la cellule de garde d'Arabidopsis thaliana : rôles dans le transport de l'eau et du peroxyde d'hydrogène". Thesis, Montpellier, SupAgro, 2014. http://www.theses.fr/2014NSAM0041.
Stomatal movements in response to changing environmental conditions are crucial for controlling the plant water status and protecting plants against pathogens. Abscisic acid (ABA) or Pathogen-Associated Molecular Patterns (PAMPs) such as the flg22 peptide, induce, via hydrogen peroxide (H2O2), signaling networks that lead to stomatal closure. Although stomatal movements involve marked water fluxes and changes in cell volume, the role of membrane water channels (aquaporins, AQP) has remained hypothetical. Functional assays in epidermal peels showed that Arabidopsis thaliana pip2;1 plants invalidated for plasma membrane AQP PIP2;1 have a defect in stomatal closure in response to ABA and flg22, but normal responses to dark, light or carbon dioxide. Guard cell protoplasts from wild-type plants showed a two-fold increase in osmotic water permeability (Pf) in response to ABA which was fully abrogated in pip2;1 plants. Plants expressing a H2O2 sensitive probe (HyPer) revealed an accumulation of H2O2 in guard cells of wild-type plants in response to ABA and flg22, which was abolished in pip2;1 plants. OST1 (SnRK2.6), a protein kinase closely linked to ABA receptors, was able to phosphorylate, in vitro and at Ser121, a cytosolic peptide of PIP2;1. SnRK2.6 also enhanced PIP2;1 water transport activity after co-expression in Xenopus oocytes. Expression in pip2;1 plants of a phosphomimetic (Ser121Asp) or a phosphodeficient form (Ser121Ala) of PIP2;1 allowed to demonstrate that the increase in guard cell protoplast Pf, the intracellular accumulation of H2O2 and stomatal closure induced by ABA and flg22 require the phosphorylation of PIP2;1 at Ser121. This work provides the first direct genetic and physiological evidence for aquaporin function in guard cells. We propose that PIP2;1 plays both a hydraulic and signaling role in guard cells, by facilitating the transport of water and H2O2 across the guard cell plasma membrane. PIP2;1 phosphorylation at Ser121, by SnRK2.6 in particular, would be required in this context
Peyrard, Dimitri. "Un modèle hydrobiogéochimique pour décrire les échanges entre l'eau de surface et la zone hyporhéique de grandes plaines alluviales". Toulouse 3, 2008. http://thesesups.ups-tlse.fr/549/.
The hyporheic zone is a bioreactor which can influence the biogeochemical functioning of fluvial hydrosystems. In this work, quantification of its role on water and solutes fluxes in hydrosystem of large alluvial floodplains was made by modelling approach. The proposed model was applied and validated using data previously measured on experimental sites of Freienbrink (Germany), Hers and Garonne (France). The complete model consists of two additional components: a hydrodynamic component (horizontal 2D Saint Venant equations for river flow and 2D Dupuit equations for hyporheic zone flow) coupled with a reactive solute-transport component for dissolved forms of mineral nitrogen and organic matter. The conclusions highlight the importance of transient exchanges between stream and hyporheic zone which facilitate water storage and denitrification processes activation
PERRIER, SEBASTIEN. "La monensine, ionophore cationique d'origine bacterienne : transport en systeme polyphase, solubilisation de ses sels d'ammonium quaternaire dans l'eau". Clermont-Ferrand 2, 1995. http://www.theses.fr/1995CLF21682.
Bedet, Jérôme Moyne Christian Mutzenhardt Pierre. "Caractérisation du transport de l'eau dans les piles à combustible par Imagerie et Spectroscopie de Résonance Magnétique nucléaire". S. l. : S. n, 2007. http://www.scd.uhp-nancy.fr/docnum/SCD_T_2007_0120_BEDET.pdf.
Simon, Laure. "Contribution à la modélisation numérique du transport de polluants en rivière". Phd thesis, Ecole Nationale des Ponts et Chaussées, 1995. http://tel.archives-ouvertes.fr/tel-00523060.
Babey, Tristan. "Compartimentation et transfert de contaminants dans les milieux souterrains : interaction entre transport physique, réactivité chimique et activité biologique". Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S107/document.
Modelling of contaminant transfer in the subsurface classically relies on a detailed representation of transport processes (groundwater flow controlled by geological structures) coupled to chemical and biological reactivity (immobilization, degradation). Calibration of such detailed models is however often limited by the small amount of available data on the subsurface structures and characteristics. In this thesis, we develop an alternative approach of parsimonious models based on simple graphs of interconnected compartments, taken as generalized multiple interacting continua (MINC) and multiple rate mass transfer (MRMT). We show that this approach is well suited to systems where diffusion-like processes are dominant over advection, like for instance in soils or highly heterogeneous aquifers like fractured aquifers. Homogenization induced by diffusion reduces concentration gradients, speeds up mixing between chemical species and makes residence time distributions excellent proxies for reactivity. Indeed, simplified structures calibrated solely from transit time information prove to provide consistent estimations of non-linear reactivity (e.g. sorption and precipitation/dissolution). Finally, we show how these models can be applied to tracer observations and to biodegradation reactions. Two important advantages of these parsimonious approaches are their facility of development and application. They help identifying the major controls of exchanges between advective and diffusive zones or between inert and reactive zones. They are also amenable to extrapolate reactive processes at larger scale. The use of isotopic fractionation data is proposed to help discriminating between structure-induced effects and reactivity
Houecande, Orianne. "Chimie de l'eau et transport particulaire dans un crassier sidérurgique : de la zone non saturée à la zone saturée". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEM022/document.
Mobile soil particles can transport pollutants to groundwater. In slag heaps, leached metallic elements contribute to soil water contamination. The aim of this work is to identify the role of slag particles in contaminant transport under unsaturated and saturated conditions. Mineralogical compositions and physicochemical properties of slags are first determined. The analysis show high temperature slag phases and weathering phases. Percolation tests are also carried out in repacked waste columns under infiltration/drying cycles to find out the effects of dry periods on in situ particle mobilization. Preferential flows lead to rapid transport of solute through the repacked column in vadose zone. Leachates are characterized by high pH and high concentrations of calcium, aluminum and silicon, molybdenum, chromium in the fusion slags. Speciation calculations showed that the leachates are saturated in calcium silicate hydrates. Laser size analyzer shows that the slag particles mobilized during the simulated rain events are around 200 µm, which suggests low mobility in the less permeable underlying formations
Vacassy, Robert. "Synthèse et caractérisations de membranes minérales de nanofiltration : Modélisations du transport de matière et de la perméabilité à l'eau". Montpellier 2, 1996. http://www.theses.fr/1996MON20082.
Faurel, Michaël. "Conception et mise en place d'expériences de diffusion de l'eau et de solutés dans des milieux poreux modèles d'argiles gonflantes". Thesis, Poitiers, 2012. http://www.theses.fr/2012POIT2320/document.
Most of existing data on diffusion of water and solutes were obtained either on extremely complex clayey rocks or on seemingly more simple samples prepared from sodium-saturated swelling clay minerals, namely smectites. Because these latter can exhibit in water-saturated conditions various organizations not yet fully understood (gel phase-floc-stable suspension), it is still difficult to constrain dual-porosity media modeling (pore or interlayer water) sometimes considered for interpreting results from diffusion experiments. A model system for swelling clay minerals, mimicking a true dual-porosity medium, was obtained by using three size fractions of a Na-vermiculite. These fractions do not exhibit gel-like behavior in water-saturated conditions but rather well defined particles, whose morphology and organization have been characterized. An experimental set-up was designed for the investigation of HDO and Br- diffusion in these size-fractions as a function of porosity. The main advantage of this set up is that it allows assessing for the organizational homogeneity of a sample prepared by sedimentation process through X-ray tomography measurements, an assumption considered for diffusion modeling. The obtained results showed that this new method for sample preparation leads to more homogeneous samples as compared to classical procedures. The first perspectives concerning the use of these dual-porosity model systems are drawn from the first diffusion results obtained, as the well-controlled geometrical characteristics of these model systems successfully help in balancing the contribution of the different potential transport processes
Massei, Nicolas. "Transport de particules en suspension dans l'aquifère crayeux karstique et à l'interface craie-alluvions". Rouen, 2001. http://www.theses.fr/2001ROUES044.
Thomas, Michel. "Transport de l'eau à travers une membrane perfluorosulfonique Nafion : relations avec la microstructure : développement de membranes composites à haute perméabilité aux gaz". Lyon 1, 1989. http://www.theses.fr/1989LYO10174.
VAN, DORPE FRANCOIS. "Dinamyque d'une pollution d'aquifere alluvial : hierarchisation des mecanismes de transport de fluides non miscibles a l'eau ; cas d'un gazole et du trichloroethylene". Université Louis Pasteur (Strasbourg) (1971-2008), 1997. http://www.theses.fr/1997STR13236.
Morillon, Raphaël. "Modifications de perméabilité cellulaire à l'eau liées au développement, au stress hydrique, et aux mutations". Rouen, 1999. http://www.theses.fr/1999ROUES032.
Des, Bourdes-Courtadeur Caroline. "Etude du transport de l'eau dans un sol labouré : modélisation 2D de l'infiltration et de la redistribution dans un sol à structure hétérogène". Paris, Institut national d'agronomie de Paris Grignon, 2002. http://www.theses.fr/2002INAP0014.
This work is a study of water transport in a loamy soil presenting an heterogeneous structure. We characterized the hydraulic properties of the various soil recognized thought the cultivation profile. In the same plot, the infiltration and redistribution of a bromide rain were measured. Hydraulic properties differed between compacted zones and porous zones, in the ploughed layer between the wheel tracks. The bromide tracing showed preferential flows located at the border of the wheel tracks, and very limited flow within the wheel tracks. Water flows were very heterogeneous in the ploughed layer between the wheel tracks and mostly concentrated within the porous zones. We tried to reproduce the water fluxes using HYDRUS 2D model by accounting for the geometry of the soil volumes and their hydraulic properties. Water fluxes were well reproduced qualitatively. The simulations showed that the structure of the tilled layer has an important effect on
Cheng, Wei. "Fate and transport of quinolones at iron oxides/water interface". Thesis, Rennes, Ecole nationale supérieure de chimie, 2019. http://www.theses.fr/2019ENCR0058.
Due to their extensive use, many emerging contaminants, such as quinolone antibiotics, are released to the environment. Because their environmental fate is largely controlled by their interaction with mineral surfaces, such as iron oxides, this thesis aimed to assess quinolones adsorption onto minerals under environmental relevant conditions (pH, ionic strength, presence of ubiquitous cations and anions, etc.) and develop reactive transport models. To address these issues, an innovative approach combining kinetic and thermodynamic data, in situ spectroscopic measurements and surface complexation modeling, was proposed. This thesis manuscript consists of two parts. The first part investigated the binding mechanisms of quinolones onto iron oxides (goethite and magnetite) under reducing or seawater conditions. Considerable impact of the magnetite stoichiometry (Fe(II)/Fe(III)) on its sorption capability towards nalidixic acid has been demonstrated. Competitive and synergetic effects of different seawater ions on quinolone adsorption to goethite were accurately predicted under static and water saturated flow-through conditions. The second part investigated the interactions of goethite with naturally occurring ligands such as natural organic matter (NOM) and their impacts on the mobility/transport of quinolones. Interactions of NOM and goethite and effects on the surface hydrophilicity were first investigated. Then, nalidixic acid adsorption to goethite and to NOM-covered goethite and NOM fractionation were examined under flow-through conditions. These results may have important implications for assessment and prediction of the fate of quinolones antibiotics in the environment
Millet, Pierre. "Modélisation du transfert et du transport de composés organiques des matériaux dans l’eau potable : Applications aux réseaux d’eau intérieurs". Rennes, Ecole nationale supérieure de chimie, 2017. http://www.theses.fr/2017ENCR0039.
The French Public Health Code sets out the requirement on tap water quality and the materials used in the contact of drinking water are subject to the Attestation of Sanitary Conformity. However, organoleptic degradation can remain in tap water. A bibliographic study has shown that organoleptic degradation could be caused by the presence of chemicals migrating from materials and by complex hydrodynamic phenomenon. A compartmental model has been developed. It models the transfer and the transport of chemicals from materials to water. This approach allows to combine the study of transfer of chemical from the material and the study of hydrodynamics in private water installations. It provides the opportunity i)- to observe the impact of dynamic operating conditions on the concentration of chemicals in tap water ii)- to make diagnostics of the installation to avoid disagreements and iii)- to study the quantity of chemicals deliver in tap water in function of consumption habits of the users. The study of chemicals transfer phenomenon in dynamic conditions has shown the impact of water temperature, turbulent agitation and duration of the use of materials on migration kinetics of chemicals. However, the experiences made with compartmental model have indicated that the leaching of chemicals in dynamic conditions was negligible compared with the leaching of chemicals in static conditions. Indeed, the static contact time is far more important that the dynamic one. However, it has been shown that the hydrodynamics could have a significant impact on tap water quality, particularly due to exchanges between different parts of the networks. Finally, the complex scenario development based on consumption habits of the users have shown that the quantity of chemicals ingest by the consumers were strongly dependant of the consumption behaviour of the users. The approach could be a part of a process like the threshold of toxicological concern based on the prediction of the daily quantities of chemicals ingest
Leoni, Nadine. "Amélioration du traitement de clarification. Contribution à l'étude des mécanismes de coagulation d'eaux douces et peu turbides par le fer(III) et d'un procédé de floculation lestée". Toulouse, INPT, 1996. http://www.theses.fr/1996INPT036G.
El, Aiba Farah. "Propriétés complexantes d'une macromolécule naturelle, un acide fulvique, vis à vis du proton et du plomb en eau douce". Paris 5, 1988. http://www.theses.fr/1988PA05P628.
Paquin, Mathieu. "Compréhension des problèmes de gestion de l'eau et de transport de masse dans une micropile à combustible à membrane de polymère fonctionnant en convection naturelle". Mémoire, Université de Sherbrooke, 2008. http://savoirs.usherbrooke.ca/handle/11143/5321.
Rault-Doumax, Sébastien. "Contribution à l'aide à la gestion de crise en cas de rejet accidentel dans un canal : application aux produits miscibles dans l'eau". Aix-Marseille 1, 2003. http://www.theses.fr/2003AIX11037.
The accidents of hazardous goods transportations occur each year. Fortunately, most of them, do not cause victims but they often pollute environment. When an accident happens, the efforts rest essentially on Fire brigade assisted by competent authorities. So SIGAPOL was born: Geographic Information System applied to the accidental pollutions of streams. This system is a platform which integrates new technologies with the aim to support decision in case of accidental pollution of streams intended for the main actor of the crisis: the Fire brigade. The SIGAPOL is based on a Geographical Information System composed of data bases and computer calculation to assess pollution. This simulation module is the most important work of this PhD. It consists of powerful modellings resulting from the literature scientific and checked by experimental studies carried out in open-channel in laboratory and real site
Guibaud, Gilles. "Etude physico-chimique du transport de l'aluminium dans les sols limousins, essai de modélisation". Limoges, 1996. http://www.theses.fr/1996LIMO0023.
Fauchereau, Nicolas. "Transport, bilan et cycle de l'eau atmosphérique en Afrique australe : mise en relation avec la variabilité de la température de surface de mer dans l'hémisphère sud". Dijon, 2004. http://www.theses.fr/2004DIJOLA07.
Klepikova, Maria. "Imaging of fractured rock properties from flow and heat transport : field experiments and inverse modelling". Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-00865302.
Lavastre, Véronique. "Evénements sédimentaires, diagénétiques et post-diagénétiques dans la formation argileuse du Callovo-Oxfordien (Bassin de Paris, France) : enregistrement isotopique des minéraux et de l'eau porale". Paris 7, 2002. http://www.theses.fr/2002PA077103.
Le, Couviour Karine. "La responsabilité civile à l'épreuve des pollutions majeures résultant du transport maritime /". Aix-en-Provence : Presses universitaires d'Aix-Marseille, 2007. http://catalogue.bnf.fr/ark:/12148/cb41216121v.
Colinart, Thibaut. "Gestion de l'eau et performances électriques d'une pile à combustible : des pores de la membrane à la cellule". Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL039N/document.
This works contributes to the understanding of water management of polymer electrolyte membrane fuel cell and of its links with the electrical performances. More specifically, the manuscript deals with the multi-scale modelling of transport phenomena. An analysis of coupled mass and charge transfer in the pores of a polymer membrane is presented. The presence of liquid water is considered in the GDL (two-phase flow) and in the active layers (flooding). The description of these phenomena is associated with that of gas depletion along the bipolar plate channels. This allows to emphasize the non-uniformity of water concentration, of the fluxes and as a consequence, of current density. The numerical results are compared with experimental data (water transport coefficient, local electrical performances) measured on two different fuel cells. This comparison validates at least partially the numerical models and provides further information for the analysis of water management within PEMFC
Sboui, Amel. "Quelques méthodes numériques robustes pour l'écoulement et le transport en milieu poreux". Phd thesis, Université Paris Dauphine - Paris IX, 2007. http://tel.archives-ouvertes.fr/tel-00284856.
Enfin une méthode numérique pour le calcul de transport de contaminants est proposée. Les techniques précédentes sont implémentées en 3-D et des résultats numériques sont présentés sur le benchmark 3-D champ lointain du GDR Momas et de l'Andra.
Plante, Ianik. "Développement de codes de simulation Monte-Carlo de la radiolyse de l'eau par des électrons, ions lourds, photons et neutrons applications à divers sujets d'intérêt expérimental". Thèse, Université de Sherbrooke, 2008. http://savoirs.usherbrooke.ca/handle/11143/4292.
Branca, Marlène. "Synthèse de nanomatériaux hybrides à base de fer et de bismuth & études des propriétés physiques". Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30018.
This manuscript reports the design of Bismuth & Iron monometallic nanoparticles (NPs) and their combination in bimetallic NPs. The choice of these metals is motivated by potential applications in Energy & Biomedical fields. In order to study the physical properties of an assembly of Bismuth NPs, the first chapter of this thesis is focused on the synthesis of Bismuth NPs below 10 nm size-diameter. A Bismuth complex is reduced by a strong reducing agent, the naphthalenide radical anion, at low temperature or by a soft reducing agent at high temperature, an alkylamine. Infra-Red spectroscopy (IR), Nuclear Magnetic Resonance (NMR), Wide Angle X-ray Scattering (WAXS) & X-Ray Absorption (XAS) are used to understand the mechanisms of the reaction & the surface chemistry of the Bismuth NPs. The second chapter is devoted to the synthesis of Iron NPs by the same reduction methods. The magnetic properties of the NPs obtained, with sizes below 2 nm and polytetrahedral structure, are described. A model study based on the transfer into water of 13 nm large Iron NPs is described, and their relaxometric properties are reported. The last chapter opens the way to multimodal contrast agents, combining the magnetic properties of Iron for Magnetic Resonance Imaging (MRI) & X-Ray Absorption properties of Bismuth for X-Ray imaging. A synthesis method affording 25nm size-diameter core-shell Bi@Fe NPs is developed. The mechanism of the reaction followed by NMR, TEM, WAXS & Mössbauer spectroscopy reveals the multiple steps of the formation of the NPs. First qualitative MRI & X-Ray attenuation tests open interesting perspectives for such bimodal probes in nanomedicine
Rodrigues, Stéphane. "Dynamique sédimentaire et végétation : évolution de chenaux fluviatiles en Loire moyenne (France)". Tours, 2004. http://www.theses.fr/2004TOUR4016.
Hydrological and sedimentological investigations were carried out on a vegetated secondary channel of the Loire River (Bréhémont, France). Sediment dynamics is important in the upstream part of the channel while an asymmetrical behaviour is noted in the downstream part : sediment by-passing in the bare areas contrasts with particle retention in the vegetated parts. Locally, flow velocities, directions and sediment deposition are influenced by vegetation. Models of evolution are discussed. During moderate floods, reduced redistributions indicate poor sedimentary supply from the mean channel. During intense floods (1) high quantities of sediments delivered by the mean channel allows the feeding of riffles and bars, (2) vegetation bands influence flow velocities and directions. Deposition and retention of sediment are induced by these bands while erosion is important in their periphery. Accretion in the vegetated areas exerts a feedback control on flow and sediment transport
Berrod, Quentin. "Relation structure - transport dans des membranes et matériaux modèles pour pile à combustible". Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00981913.
Goeury, Cédric. "Modélisation du transport des nappes d'hydrocarbures en zone continentale et estuarienne". Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1131/document.
The application of the European Water Framework Directive on water quality for human consumption and industrial activities creates a need for water quality assessment and monitoring systems. The MIGR'HYCAR research project (http://www.migrhycar.com) was initiated to provide decisional tools for risks connected to oil spills in continental waters (rivers, lakes and estuaries), which represent more than 50% of accidental spills in France. Within the framework of this project, a new numerical oil spill model has been developed, as part of the Telemac hydro-informatics system (see: (http://www.opentelemac.org), by combining Lagrangian and Eulerian methods. The Lagrangian model describes the transport of an oil spill near the free surface. The oil spill model enables to simulate the main processes driving oil plumes: advection, diffusion, oil beaching, oil re-floating, evaporation, dissolution, spreading and volatilization. Though generally considered as a minor process, dissolution is important from the point of view of toxicity. To model dissolved oil in water, an Eulerian advection-diffusion model is used. The fraction of dissolved oil is represented by a passive tracer. This approach is able to follow dissolved hydrocarbons in the water column. Laboratory experiments were conducted to characterise the numerous kinetics of the processes listed above. In addition, meso-scale dynamic experiments in artificial channels and test cases derived from the literature are used to validate the numerical model
Luu, Thi Nguyet Minh. "Transport de matières et qualité des eaux dans le continuum du bassin du Fleuve Rouge au Delta : bilan et modélisation". Paris 6, 2010. http://www.theses.fr/2010PA066303.
Mazoyer, Camille. "Modélisation des flux et du transport de polluants en rade de Toulon". Electronic Thesis or Diss., Toulon, 2019. http://www.theses.fr/2019TOUL0005.
This doctoral research aim was to study hydrodynamic processes in a semi-enclosed bay such as the Toulon bay and their importance for the dispersion of dissolved contaminants. For this study, a YfilY high resolution (100 m spatial resolution) configuration named TBAY100, based on the MITgcm ocean circulation model, was implemented. A multi-model nesting was carried out ta work at such a resolution, starting from a 1.3 km NEMO-GLAZUR64 configuration of the North-Western Mediterranean then a 400 m NEMO-NIDOR configuration of the Var coastline ta correctly force the TBAY100 boundaries. Firstly, a mathematical analysis aimed to guantify energy exchanges for a simplified system then this analysis has been extended ta the Toulon bay to better understand the exchanges at the domain open boundaries. This configuration was then validated with various observations inoludin ADCP data and driftin eolocalisable
Maldonado, Sánchez Libeth. "Experimental characterization of water sorption and transport properties of polymer electrolyte membranes for fuel cells". Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0146/document.
The overall aim of this PhD thesis was to characterize the properties of commercial Nafion N115 and Nafion NRE212 membranes in term of water sorption, transport, and mechanical properties over a wide range of experimental conditions. Because of the high dispersion of the data in the literature, our primary objective was to gather a comprehensive set of experimental measurements and to compare them with published results. Simple and reproducible protocols allowed us to measure the membrane properties over a wide range of experimental conditions and to study the influence of certain parameters on their evolution. For example, the samples were heat-treated at different temperatures and the effect of thermal history on water sorption, transport and mechanical properties was investigated. Nafion membranes were also exposed to moderate temperature (60°C - 80°C) and constant relative humidity (RH = 0.3 to 0.95) for long periods of time, which is known to cause a so-called ?hygrothermal aging? resulting in a decrease in their sorption capacity and proton conductivity. Such effects were observed but they appeared to be reversible and without noticeable consequences in term of fuel cell performance. Our experimental results can be used in studies involving water transport, water management and durability of fuel cells, especially for numerical simulation or modelling. More fundamentally, they can help understanding the thermodynamics of sorption and transport phenomena in PFSA membranes
COLLON, Pauline. "Evolution de la qualité de l'eau dans les mines abandonnées du bassin ferrifère lorrain. De l'expérimentation en laboratoire à la modélisation in situ". Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2003. http://tel.archives-ouvertes.fr/tel-00004521.
El, Hannach Mohamed. "Simulation et analyse des mécanismes de transfert diphasique dans les Couches Actives des Piles à Combustible PEMFC". Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0092/document.
In order to use PEM fuel cells in an automotive application, their cost must be reduced and their lifetime must be increased. Many results show that water management is a critical issue in PEMFC optimization. The water is produced in the cathode active layer (CCL) which makes the optimization of this component very important to ensure a better water management in the PEMFC. In this work, the pore network method has been adapted to model the two-phase transport in the porous structure of the CCL. Considering the state of the art, this is the only model developed to analyze the effect of local properties of the CCL (structure, wetting ...) on the two-phase transport mechanisms. This model is proposed as a scientific tool to help understanding the fundamentals behind the transport phenomena inside the CCL and also to help in the conception of the future CCL. The liquid invasion algorithms developed in this work were analyzed in details. The fluids transport (gas and liquid) is coupled with the charges transport (electrons and protons) using an electrochemical reaction model. The capillary driven liquid transport, the gas phase diffusion and the evaporation process are all integrated into the model in order to have the most possible complete description of the CCL. The description of the porous structure by a regular network, the liquid invasion algorithm and the gas diffusion model all have been validated by comparisons with experimental results from literature or specific work . The model is then exploited to analyze the effect of parameters such as the CCL wettability and pore size distribution on the performance. The results allow analysis of initial ideas that can help in the conception of the CCL in order to improve the water management and the performances of the PEMFC
Trieu, Hung Truong. "Études théorique et expérimentale du transport de fluides miscibles en cellule Hele-Shaw". Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL027N/document.
This thesis is an experimental and numerical investigation of solute transport and sedimentation in a Hele-Shaw cell with zonal flow. A vertical cell joining two large tanks has been built to provide a uniform horizontal flow, the velocity of which has been measured by using PIV. The concentration field of a solute injected in this flow has been measured by using LIF. Three typical plume configurations have been observed: without digitations (“stable”), with a single digitation (“weakly unstable”), and with various digitations appearing at the lower interface (“unstable plume”). The influence of density contrast, zonal flow and solute flow rate on the appearance of the various configurations has been investigated. These results have been compared to numerical simulations using the COMSOL Multiphysics® software. The numerical concentration fields are in qualitative agreement with the experimental ones. In addition, these simulations allowed us to investigate the effect of the anisotropy of the dispersion tensor on the occurrence of unstable configurations. A linear stability analysis based on a uniform parallel flow superposed to a quasi-steady horizontal layer of solute has been performed. It shows that the plume is convectively unstable for the parameters considered here, and confirms the various behaviors observed in both the experimental and the numerical analyses, like the stabilizing effect of the longitudinal dispersivity or the destabilizing effect of the solute concentration
Guillemoto, Quentin. "Transfert des molécules organiques traces des eaux usées traitées dans un système de Soil Aquifer Treatment (SAT) : application à l’hydrosystème côtier d’Agon-Coutainville". Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS510.
Pressures on groundwater (droughts, overexploitation, pollution, etc.) contribute to an overall decrease in the availability of the resource. Manages Aquifer Recharge (MAR) and Soil Aquifer Treatment (SAT) have clear advantages for future sustainable quality and quantity management of groundwater, especially through the use of treated wastewater. The preservation of groundwater quality when introducing these so-called unconventional waters into MAR must be ensured. A major difficulty lies in understanding the processes induced by these techniques that affect groundwater quality. These include the Trace Organic Compounds (TrOCs) present in treated wastewater, which have received particular attention in recent years. To date, the understanding of the fate of TrOCs at the scale of a SAT site is very limited despite a growing knowledge of the processes induced (degradation, sorption). Even fewer studies consider the SAT system as an integral part of a natural hydrosystem, in which the dynamics of groundwater flows increase the complexity of the behaviour of these molecules. The methodology of the thesis combines data analysis, experimentation and modelling implemented at different spatio-temporal scales. It was applied to the coastal SAT site located in Agon-Coutainville (Normandy, France) which has been active for more than 20 years. Interpretation of the data acquired in the field using geochemical and time series analysis tools allowed a first description of the behaviour of a selection of TrOCs within a SAT system. The results at the site scale show the diversity of behaviour of TrOCs in the SAT associated with reactive, operational and hydrodynamic factors. A controlled infiltration experiment under operational conditions at the scale of an infiltration basin over 35 days was interpreted using geochemical modelling tools and analytical modelling of reactive transport (Advection-Dispersion Equation, ADE). The results show a natural attenuation of TrOCs from the SAT after an average residence time of 12 days in the SAT by quantifying first-order degradation coefficients (μ) and retardation coefficients (R) for some molecules On the multi-year scale of the aquifer hosting the SAT system, a flow and transport model (MARTHE) was built to quantify the influence of environmental factors (climate, tides, operational conditions) on the coastal hydrosystem with regard to the fate of TrOCs. The results of the model show their impact on flow rates, dilution and reactivity of TrOCs. An attenuation of TrOC concentrations by reactivity is expected over two-thirds of the surface of the SAT during the driest six months of the year, while over the remaining surface, local marine dynamics lead to a decrease in concentrations mainly by dilution. At the natural outlet of the aquifer, the simulated average residence times range from 74 to 489 days depending on the seasonal dynamics, which could be specified by additional investigations concerning the surface water (sea and river). This work provides an innovative multidisciplinary methodology integrating various tools to address the fate of TrOCs in SAT systems at different spatial and temporal scales, while considering the hydrodynamic and reactive behaviour of such systems. Many perspectives to this thesis work are arising, particularly concerning the characterisation of the reactivity of TrOCs in such systems in a coastal context, or the development of hydrodynamic modelling tools integrating more mechanistic reactive processes, which would improve the understanding of the behaviour of TrOCs in these systems
Rambourg, Dimitri. "Transposition de paramètres estimés par inversion d'un modèle hydrodynamique bidimensionnel à un modèle de transport de soluté tridimensionnel : méthodologie et application à un aquifère alluvial". Thesis, Strasbourg, 2020. http://www.theses.fr/2020STRAH014.
The thesis proposes a tool for modelling flows and the transport of dissolved pollutants in aquifers, with an example of application to the CEA site at Marcoule (Gard). The methodological developments and the application to the study site are divided into three phases. An inversion of the hydrodynamic parameters of the aquifer in 2D, with a formulation adapted to the context of the study site (constraint of the complex topography of the aquifer bedrock, integration of large-scale geological data), allows the behaviour of the alluvial water table at Marcoule to be reproduced with fidelity and robustness. 3D hydrogeological models are then constructed by interpolating borehole data using two methods (a stochastic approach and a deterministic approach). The parameterisation of the heterogeneities produced by the interpolation exploits the 2D inversion’s transmissivity values. Finally, the parameterised hydrogeological model is used to simulate the flow and transport of dissolved contaminants in three dimensions, in the saturated zone and the vadose zone
Beauger, Aude. "Bio-évaluation de la qualité de l'eau : établissement d'un protocole d'échantillonnage simplifié, basé sur la collecte des macroinvertébrés benthiques sur les seuils des rivières à charge de fond graveleuse". Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2008. http://tel.archives-ouvertes.fr/tel-00730658.
Schmitt, Tobias. "Method development and experimental investigation of dynamic water distribution in a segmented PEMFC". Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0021.
Proton exchange membrane fuel cells (PEMFCs) represent a promising technology as an electric powertrain in automotive application that becomes increasingly superior to the internal combustion engine. Over the past years, the deconvolution of internal processes has been studied intensively, leading to an improvement of performances and lifetime while reducing the costs. Yet, many underlying mechanisms are still not fully understood, as the experimental methods are partly limited. Water distribution in a PEMFC plays a pivotal role in its performance and transient response. The experimental study of its influence is challenging and expensive. In addition, there is a lack of experimental methods that can combine spatially and temporally resolved data at a scale that allows investigation of impacts at the industrial cell or stack level.This work focuses on developing methods that can provide insight into spatially and temporally resolved influences of water distribution on the performance of PEMFCs and their investigation. Therefore, a highly instrumented and segmented PEMFC with straight parallel channels in combination with a self-developed control system is installed. The flexibility of the self-developed control system allows to establish a local electrochemical impedance spectroscopy (Lo EIS) measurement along the channel. In addition, a parametrization workflow is established, that links humidity sensitive resistances to temperature and applied relative humidity. These resistances, spatially resolved by Lo EIS, can then be transferred into a equivalent local humidity to study the humidity distribution along the channel and its effect on steady-state performances.In order to investigate not only steady-state but also transient conditions, Lo-EIS is further developed into the rapid and local EIS method (RaLo-EIS). The RaLo EIS acquires spectra within a reduced range of frequencies (10 kHz→20 Hz) for all 20 segments of the cell within 1 second. Such spatially and temporally resolved impedance data are a novelty for PEMFC and offer new insights into the transient behavior of PEMFCs. With RaLo EIS transient experiments are conducted, showing the inhomogeneity of the response of a PEMFC. It further reveals how much information is lost, if only globally averaged data is acquired.Since the use of humidity sensitive resistors that need to be fitted is challenging for the parameterized calculation of local humidity, fixed frequency impedances are used for this purpose. To prove the independence of fixed frequency a robust comparison of the resulting relative humidity based on multiple frequencies is conducted. The comparison shows that the resulting equivalent humidity is almost independent of the chosen frequency.To further speed up the acquisition rate of RaLo EIS, a speed optimized version, the rapid and local fixed frequency (RaLoff) EIS is developed to acquire temporally high resolved data. This method is then used to investigate and characterize the transient response of PEMFC to sudden changes in its conditions. A qualitative model is developed, that explains the resulting behavior in terms of performance and humidity distribution. A characterization method for transient responses is created, that can be used to reduce the complexity of such processes, making it possible to compare different materials in terms of their transient behavior.In the end a new approach for a transmission line model (TLM) is developed, as the established ones from literature are incapable of properly fitting experimental data for some cases. This new TLM is based on not yet validated assumptions but provides excellent matches with experimental data
Maquignon, Nicolas. "Vers un modèle multiphases et multicomposants (MPMC) de type Lattice Boltzmann Method (LBM) pour la simulation dynamique d'un fluide cyogénique dans l'eau". Thesis, Littoral, 2015. http://www.theses.fr/2015DUNK0426/document.
In this thesis, a LBM MPMC model with heat exchange is developed. Data assimilation tests and optical flow measurements are made in order to validate the model. The application context of this thesis is the mixture of a cryogenic fluid with water. In the first part, a bibliographical work reminding the Boltzmann equation and its various assumptions and simplifications, as well as the algorithmic aspect of the LBM are exposed. A comparison between SRT and MRT collision operator is performed, and a simulation of turbulent phenomena at different Reynolds numbers is studied, especially with the benchmark of the instability from Von Karman. In the second part, the MPMC model from Shan & Chen is reminded and extended to the case of the inter-component heat exchanges. Quantitative validations are made, especially with the benchmark of a two-phase or two-component Couette fluid. Consistency is tested against Laplace's law rule, or against a benchmark involving heat conduction. Qualitative testing of condensations in a multi-component medium are proposed to validate the heat exchange between components in the presence of a phase transition. In the third part of this thesis, a validation method for data assimilation is introduced, with the ensemble Kalman filter. A state estimation test of a bi-phase fluid is realized, and compatibility of the ensemble Kalman filtering to the LBM MPMC model is assessed. For validation of the behavior of the model for a two-component case, a substitution fluid (non-cryogenic) for LNG, butane, was selected to permit observations in experimental conditions which are accessible. Then, an experimental platform of injection of liquid butane in a pressurised water column is presented. Shadowgraph images from liquid butane experiments in water are exposed and an optical flow calculation algorithm is applied to these images. A qualitative assessment of the velocity field obtaines by application of this algorithm is performed
Hannouche, Ali. "Analyse du transport solide en réseau d’assainissement unitaire par temps de pluie : exploitation de données acquises par les observatoires français en hydrologie urbaine". Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1134/document.
This thesis exploits continuous measurement of rainfall, discharge and turbidity data and the knowledge acquired by three French observatories in urban hydrology, OPUR-Paris, OTHU Lyon and ONEVU-Nantes, to validate and improve knowledge on suspended solids discharges and sources of particles, which are major vectors of contaminants in combined sewer systems. Data from six experimental sites served by a combined sewer system were used: Marais, Quais and Clichy in Paris, Cordon Bleu and Saint-Mihiel in Nantes and Ecully in Lyon. At each site, a long duration databases enabled statistical studies on samples of several tens of rainfall events and dry weather days. This thesis allowed: 1-to assess the representativeness of turbidity to analyze sediments transport in network; 2-to analyze and model concentrations and masses of particles at the scale of rain events; 3-to study the dynamics of fluxes and concentrations at intra-event scale. Results show that turbidity can describe the dynamics of intra-event fluxes and concentrations provided these are expressed in a relative form, normalized by the event mean values. However, these mean values are attached by significant systematic errors induced by variations of the inter-event TSS-turbidity relationship (95% confidence interval about 30% of average). The contribution of sewer deposits to wet weather suspended solids discharges is important but variable (between 20 and 80% of the mass at the outlet depending on the event), including for a site allegedly free of (coarse) sewer deposits. In other words, the problems of silting and contribution from deposits to wet weather pollution are not necessarily related. The other major contribution is from “dry weather” wastewater. In addition, they we made some progress in understanding the lag-time phenomena between hydrograph and pollutograph and the piston effect