Dissertationen zum Thema „Gaz dans les mines“
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Mafuta, Kasonga Rody. „Impact de la mécanisation sur la ventilation dans les mines souterraines du Québec“. Thesis, Université Laval, 2013. http://www.theses.ulaval.ca/2013/30461/30461.pdf.
Der volle Inhalt der QuelleThe objective of this project is to develop a profile of the use of equipment powered by an internal combustion engine in Quebec underground mines and establish their impact on air quality. Thus, from June 2010 to September 2011, 17 underground mines in the province were contacted. The database obtained contains 9 producing mines and 4 mines under development. These data were used to calculate indices of compliance with respect to concentration limits and sampling of carbon monoxide as well as diesel particulate matter (DPM). In addition, some DPM control technologies are presented, the potential for reducing the average concentration of DPM in the main network is evaluated for some control technologies. Finally, some indices were calculated to establish the impact of mechanization on ventilation requirements.
Roy, Jonathan. „Investigation sur l'impact de la concentration de moussant dans un système solide-liquide-gaz et automatisation d'un capteur de dimension des bulles“. Thesis, Université Laval, 2013. http://www.theses.ulaval.ca/2013/29874/29874.pdf.
Der volle Inhalt der QuelleSurfactant agents are used in flotation columns to improve the physical and chemical properties of the slurry. In general, they directly affect the superficial tension by decreasing the energy necessary for bubble formation and by increasing their elasticity. The main objective of this master’s thesis is to verify the impact of frother concentration in a three-phase (solid/liquid/gas) system on the air hold-up. The thesis also deals with the availability of an automated system for bubble diameter measurement (bubbles viewer) in a three-phase system (slurry-air). The study reveals that for high concentration, hydrophobic particles seem to cancel the effect of the bubble on the gas hold-up. Furthermore, the type of conductivity cell used is problematic because it promotes preferential flow (pulp/bubbles). Lastly, the bubble viewer can be operated with solids, but it is recommended changing its geometry.
Salhi, Rached. „Effet de l'humidité du gaz vecteur et de l'assistance UV dans le procédé aérosol CVD pour l'élaboration de couches mines fluorescentes dopées terre rare“. Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00625424.
Der volle Inhalt der QuelleBourgeois, Aléxis. „Adsorption et condensation de gaz dans des couches minces diélectriques mésoporeuses suivies par ellipsométrie“. Paris 6, 2005. http://www.theses.fr/2005PA066568.
Der volle Inhalt der QuelleYordanov, Yvan. „Incorporation des clusters métalliques dans des matériaux poreux et mise en forme de couches minces : [Thèse soutenue sur un ensemble de travaux]“. Caen, 2010. http://www.theses.fr/2010CAEN2072.
Der volle Inhalt der QuelleThe development of synthesis approach for preparation of nanosized microporous materials, stabilization of metallic clusters in confined spacing with desired shape and size, and preparation of thin films based on metal-containing porous nanocrystals to be used as chemical sensors in selective vapour media are the goals of the thesis. This work contributes to better understanding of the entire process of confinement of metal clusters such as Ag, Pt, Pd and Cu in BEA type zeolite and MIL-101 Metal Organic Framework type materials. Both chemical and physical approaches for preparation of metal clusters are applied. The metal containing porous nanoparticles stabilized in suspensions are subjected to chemical, γ-radiation and plasma treatments in order to reduce the metal ions to metal clusters. Further the suspensions are used for deposition of thin films on silicon wafer via spin coating in the presence of binding agents. It is found that the metal clusters (Ag, Pt, Pd and Cu) have different size and shape in the BEA and MIL-101 hosts depending on the conditions of preparation, concentrations of metal cations and solid particles, and methods of reduction. The structural properties of the Me-containing porous films are investigated with variable surface sensitive methods and applied for CO and H2O detections
Lauque, Pascal. „Caractérisation des propriétés physico-chimiques, électriques et optiques de films minces de GaxAs1-x amorphe hydrogéné obtenus par décharge luminescente RF“. Toulouse 3, 1990. http://www.theses.fr/1990TOU30224.
Der volle Inhalt der QuelleLe, Gal Nils. „Libération et migration du méthane depuis le charbon dans un contexte hydrogéologique post-minier : développement d'un protocole expérimental et approche numérique“. Electronic Thesis or Diss., Paris, ENMP, 2012. http://www.theses.fr/2012ENMP0021.
Der volle Inhalt der QuelleAn experimental laboratory device has been developed in order to better characterize the possibility if gas emissions from flooded coal mines. Coal samples, saturated with methane, have been submitted at hydrostatic pressure from 3 to 4.3 MPa in an autoclave cell. The initial set-up and the technical apparatus added during the thesis work permit to establish an operational protocol. The results and their analysis highlight two processes: a significant desorption of methane from the flooded coal and the impact of the water penetration in the coal pores on the hydrostatic pressure. The pressure levels the coal was submitted to reveal that an increase of hydrostatic pressure enhances desorption and dissolution, as a consequence of a deeper solicitation of the methane-saturated pores.The experimental equilibrium constants have been taken into account in numerical models aiming to simulate the methane migration in flooded mine structures. The simplest models showed the importance of coal and mine voids permeability and the methane release limitation by flooding. The methane concentration in water is controlled by the desorption constant of the coal and its initial methane content. Other models simulating a flooding management context illustrate the impact of pumping on methane release and its influence concerning an eventual surface emission after decades or even century
Gaio, Thierry. „Mécanismes de transfert dans les films liquides minces ondés : application à l'absorption du dioxyde de soufre par le diméthyléter tétraéthylène glycol“. Toulouse, INPT, 1997. http://www.theses.fr/1997INPT031G.
Der volle Inhalt der QuelleKerlau, Marie. „Nouveaux matériaux pour capteurs chimiques de gaz dans les systèmes Ga-O-N et Ta-O-N : Synthèse, caractérisation et mise en forme (couches épaisses, couches minces). Application à la détection de gaz toxiques et explosifs“. Rennes 1, 2003. http://www.theses.fr/2003REN10080.
Der volle Inhalt der QuelleCavarroc, Marjorie. „Nucléation, croissance et comportement de poussières dans les plasmas réactifs radiofréquence basse pression : Des nanocristaux aux grains submicroniques polycristallins“. Phd thesis, Orléans, 2007. http://www.theses.fr/2007ORLE2029.
Der volle Inhalt der QuelleEnache, Ionut Caquineau Hubert. „Etude expérimentale et modélisation du transfert de matière dans des décharges de Townsend à pression atmosphérique en mélange HMDSO-N2O-N2 et SiH4-N2O-N2“. Toulouse (Université Paul Sabatier, Toulouse 3), 2008. http://thesesups.ups-tlse.fr/97.
Der volle Inhalt der QuelleSarra-Bournet, Christian. „FONCTIONNALISATION DE SURFACE DE POLYMÈRES PAR PLASMA À LA PRESSION ATMOSPHÉRIQUE : Amination de surface et dépôt de couches minces par un procédé de décharge par barrière diélectrique“. Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26904/26904.pdf.
Der volle Inhalt der QuelleThe objective of this thesis was to develop surface modification processes using atmospheric pressure plasma for the surface functionalization of polymers with amino groups (NH2) for biomedical applications. Developing a process working at atmospheric pressure aims to eliminate the need for a pumping system, thus obtaining a technology that would be efficient and low cost for an industrial process. The plasma generation mode chosen was a dielectric barrier discharge (DBD). Two surface modification strategies were investigated: Surface plasma amination and plasma thin film deposition. The two different types of surface modifications were characterized by X-Ray Photoelectron Spectroscopy (XPS), Time of Flight Secondary Ion Mass Spectrometry (ToF SIMS), Fourier Transform Infrared Spectroscopy (FTIR), Contact Angle goniometry (CA), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). On one hand, surface plasma amination, results demonstrate the importance of H2 and its derived species for amino groups functionalization on the surface of polymers in an atmospheric pressure DBD in N2-H2. Moreover, the obtained knowledge allows now the possibility to control and optimize the surface density and surface modification specificity for amino groups. On the other hand, the functionalized thin films obtained in an atmosphere of N2-C2H4 reveals a highly variable nitrogen concentration as a function of the reactive gas/carrier gas (C2H4/N2) while the surface density in amino groups is constant. Sticking coefficients and/or surface mobility of the different species created as a function of time residence in the discharge lead to different coating morphologies. The addition of H2 in the discharge leads to the formation of nanoparticles and new structures, named “nanorods” that present anisotropic dimensions (100-200 nm in diameter for 1-10 m in length). Finally, atmospheric pressure DBD surface functionalization is an efficient and low cost technique for the creation of uniform surface modification with amino groups that can be later used to covalently graft various chemicals functionalities; chemical functionalities that can be used for various applications.
Chapelle, Audrey. „Élaboration et caractérisation de films minces nanocomposites obtenus par pulvérisation cathodique radiofréquence en vue de leur application dans le domaine des capteurs de CO2“. Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1858/.
Der volle Inhalt der QuelleThis work involves the deposition and the characterization of nanocomposites thin films by rf-sputtering method from a delafossite (CuFeO2) target for use as sensing materials for CO2 gas sensors. Thin films were deposited using four conditions by varying argon pressure and target-to-substrate distance. First of all, the structure and the microstructure were studied for the as-deposited samples. The presence of metallic copper showed the reducing feature of the technique. Spherical copper particles were found to be within the layer, as well as rod-shape particles were localized at the interface with the substrate. Metallic copper content was dependant of the deposition conditions. Indeed, incident particles are very energetic at low pressure and small target-to-substrate distance, leading to a partial reduction of the growing layer. In this case, metallic copper content is important. In a second step, the thin films were annealed in air in order to oxidize the phases and to obtain the composite CuO/CuFe2O4. Scanning electron microscopy images showed a structure in two layers stacked on top of each other. Analysis by photoelectron spectroscopy revealed that the surface layer is composed by CuO and the heart layer by CuFe2O4. Finally, the original material associating a p-type oxide (CuO) and a n-type oxide (CuFe2O4) showed a p-type semiconductor behavior to CO2 gas. Best response was obtained for a sample deposited in the most reducing conditions and was close to 50%. Response and recovery time were 65 and 8 min, respectively
Le, Coz Thomas. „Fonctionnalisation d'un fil métallique par croissance de films minces dans un magnétron cylindrique inversé“. Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI016.
Der volle Inhalt der QuelleThe work presented in this manuscript deals with the optimization of the process of deposition of thin films on a moving stainless steel wire. Two inverted cylindrical magnetrons (ICMs) are used to study different aspects of sputtering. At first, an analytical model allowing the evaluation of the thermal contributions to the heating of the substrate is confronted with series of measurements. The results obtained are conclusive but suffer from the inhomogeneity of the magnetic field, which is responsible for the localized loss of high energy secondary electrons. In order to limit the thermal contribution of the charges on the substrate, auxiliary anodes designed to recover the energy flow, are added to each end of the magnetrons. Their influence on the plasma distribution, the microstructure and the chemical composition of the coatings is then discussed. In a second part, the study of reactive sputter deposition with ICMs highlights the need to homogenize the magnetic field in the cathodes. A discussion is then conducted on the influence of the magnetic field on the distribution of deposition rates within the magnetrons and an analytical model, aimed at reproducing the deposition profiles, is developed on the basis of the results obtained. A parametric study (pressure, target – substrate distance, magnetic field strength) is also performed to determine optimal deposition conditions in an ICM. Finally, finite element modeling using commercial software closes the manuscript
Svarnas, Panayiotis. „Etude expérimentale de l'influence du plasma froid (N2, O2, Ar, Air) créé dans une décharge luminescente de géométrie pointe-plan sur les propriétés de surface de matériaux polymères : application au traitement des couches minces de PS“. Pau, 2004. http://www.theses.fr/2004PAUU3014.
Der volle Inhalt der QuelleThe principal objects of the present thesis are : the optimized production of atactic polystyrene thin films of increased wettability, the study of macroscopic characteristics of the plasma in absence/presence of these samples and the definition of specific mechanisms which govern the plasma-polymer interaction. The techniques used are NMR, XPS, SEM, AFM analyses, contact angle measurements, electrical and optical measurements. Contact angles varying between 5ʿ and 20ʿ are obtained with drops of deionized water. The applied treatment does not practically alter the surface mophology of the thin films. The excited neutral species play the principal role to the surface treatment and the emphasis is givent to the role of metastable particles. The polymer provokes changes in the cathodic sheath of the discharge
Le, Gal Nils. „Libération et migration du méthane depuis le charbon dans un contexte hydrogéologique post-minier : développement d'un protocole expérimental et approche numérique“. Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2012. http://pastel.archives-ouvertes.fr/pastel-00734686.
Der volle Inhalt der QuelleDemarne, Vincent. „Réalisation d'un capteur de gaz intégré sur silicium : étude des mécanismes physicochimiques liés au fonctionnement de ces capteurs, dans le cas de couches minces de dioxyde d'étain pur et dopé /“. [S.l.] : [s.n.], 1991. http://library.epfl.ch/theses/?nr=934.
Der volle Inhalt der QuelleAmrani, Rachid. „Croissance et propriétés des couches minces de silicium hydrogéné déposées au voisinage de la zone de transition amorphe nanocristalline par PECVD à partir d’un plasma de silane dilué dans un gaz d’argon“. Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20058.
Der volle Inhalt der QuelleThe main objective of this thesis is to contribute to the understanding of the optoelectronics properties of hydrogenated nanocrystalline silicon thin films, a detailed study has been conducted. The samples were deposited by 13.56 MHz PECVD (Plasma Enhanced Chemical Vapor Deposition) of silane argon mixture. The argon dilution of silane for all samples studied was 96% by volume. The substrate temperature was fixed at 200 °C. The influence of depositions parameters on optical proprieties of samples was studied by UV-Vis-NIR spectroscopy. The structural evolution was studied by Raman spectroscopy, TEM, AFM, FTIR and X-ray diffraction (XRD). Intrinsic-layer samples depositions were made in this experiment in order to obtain the transition from the amorphous to crystalline phase materials. The deposition pressure varied from 400 mTorr to 1400 mTorr and the RF power from 50 to 250 W. The structural evolution studies show that beyond 160 W, we observed an amorphous-nanocrystalline transition, with an increase in crystalline fraction by increasing RF power and working pressure. Films near the amorphous to nanocrystalline transition region are grown at reasonably high deposition rates (3.5- 8 Å/s), which are highly desirable for the fabrication of cost effective devices. The deposition rate increases with increasing RF power and process pressure. Different crystalline fractions and crystallite size can be achieved by controlling the process pressure and RF power. These structural changes are well correlated to the variation of optical and electrical proprieties of the thin films
Loretz, Jean-Charles. „Elaboration par décharge luminescente radiofréquence de couches minces de nitrure d'aluminium hydrogéné. Etude des propriétés électriques des films“. Toulouse 3, 1994. http://www.theses.fr/1994TOU30087.
Der volle Inhalt der QuelleEnache, Ionut. „Etude expérimentale et modélisation du transfert de matière dans des décharges de Townsend à pression atmosphérique en mélange HMDSO-N2O-N2 et SiH4-N2O-N2“. Toulouse 3, 2007. http://thesesups.ups-tlse.fr/97/.
Der volle Inhalt der QuelleThe aim of this work is to better understand the primary deposition mechanisms in atmospheric pressure plasma-enhanced thin film deposition in order to optimize the processes which lead to a silicon oxide film in HMDSO-N2O-N2 or SiH4-N2O-N2 mixtures. First, the chemical and structural layer properties were determined for various experimental conditions. The process is then simulated using FLUENT(c) taking into account fluid dynamics, mass-transfer and chemical reactions. Once validated based on experimental results, this simulation provides a better understanding of the mechanisms which govern the growth process. For HMDSO-containing mixtures, our results highlight that the HMDSO dissociation into silicon-containing radicals is the process rate-limiting step. The relative importance of convection and diffusion in the transport of radicals is quantified. The model also shows that HMDSO quenches nitrogen metastable species which are responsible for the dissociation of the precursor. For SiH4-containing mixtures powders appear to form at rates which are much higher than those allowed by the gas-kinetic theory. Besides, the influence of the gas recirculations on the discharge stability and on the film homogeneity is established. Based on our results, an optimization study of the cell discharge is achieved
Braine, Jonathan. „Gaz moléculaire dans les galaxies spirales“. Paris 7, 1992. http://www.theses.fr/1992PA077283.
Der volle Inhalt der QuelleIn this thesis I present a study of nearby spiral galaxies (7 to 24 Mpc; H₀ = 75km/s/Mpc) selected on the basis of their blue magnitude. We have observed them in the J = 1-->0 and J = 2-->1 rotational transitions of the ¹²CO molecule in order to investigate the physical conditions of the molecular gas in the central ∼ kiloparsec of spiral galaxies. This is the first survey of ¹²CO(2-1) emission and the highest resolution study of ¹²CO(1-0) emission in galaxies. The molecular gas in the galactic centers appears optically thick in the lines observed and the average line ratio CO(2-1)/CO(1-0)=0. 9. This implies that the excitation temperatures are similar in both transitions. In order for this to be true, the emitting gas must be quite dense, probably about ∼10⁴ mol cm⁻³ or more. If the gas were significantly less dense then the higher transition would be less efficiently excited. Points along the major and/or minor axes were observed as well and show that at high angular resolution there is no standard radial distribution and that off-center maxima are quite frequent (∼ 1/3 of the galaxies). These peaks likely correspond to molecular rings. Comparing the optically perturbed systems to the non-interacting galaxies, we find that the neutral gas is both more abundant and more centrally concentrated in the disturbed galaxies. We suggest that spiral galaxies contain ionized gas in rotation beyond the optical and neutral gas disks. During a gravitational encounter, this diffuse gas is projected inwards where it cools and recombines. We believe that this is the source of the extra neutral gas
Méolans, Joseph Gilbert. „Echanges vibrationnels dans les gaz diatomiques“. Aix-Marseille 1, 1992. http://www.theses.fr/1992AIX11030.
Der volle Inhalt der QuelleTarruell, Leticia. „Superfluidité dans un gaz de fermions ultrafroids“. Phd thesis, Université Pierre et Marie Curie - Paris VI, 2008. http://tel.archives-ouvertes.fr/tel-00429181.
Der volle Inhalt der QuelleTarruell, Letitia. „Superfluidité dans un gaz de fermions ultrafroids“. Paris 6, 2008. http://www.theses.fr/2008PA066671.
Der volle Inhalt der QuelleLoinard, Laurent. „Le gaz moléculaire dans la galaxie d'Andromède“. Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10040.
Der volle Inhalt der QuelleNiyonzima, Sébastien. „Collisions réactives dans les gaz d'intérêt énergétique“. Thesis, Le Havre, 2013. http://www.theses.fr/2013LEHA0021/document.
Der volle Inhalt der QuelleThis thesis devoted to the study of reactive collisions in gases of energetic interest concerns two aspects. Firstly, a Multichannel-Quantum-Defect-Theory-type approach [Giusti 1980, Nakashima 1987] is used in the treatment of the dissociative recombination (DR), vibrational excitation (VE), and vibrational de-excitation (VdE) of BeH+ in their four lowest vibrational states (X1Σ+,v i+ =0,1,2,3). The molecular structure data previously computed [Roos 2009] have been employed in the calculations of cross sections and rate coefficients of DR, VE and VdE including three electronic symmetries of BeH (2Π, 2Σ+ et 2∆ ). The vibrational dependence [Niyonzima 2013] and the isotopic effects in these collisional processes are highlighted – Figure (V.7) – in order to be used in the modeling of the edge fusion plasma [Celiberto 2012]. Satisfactory agreement with results computed with the wave packet method [Roos 2009] is reached at intermediate energies [Niyonzima 2013]. Thereby, this part of the thesis work extends the previous study of [Roos 2009]. The MQDT-based approach, able to fully account for the temporary captures of electrons in Rydberg bound states, as well as the vibronic coupling between ionization channels, provides the first results (reliable) at low energies [Niyonzima 2013]. Lastly, an approximate analytical formulation of DR, VE and VdE cross section for the prediction and interpretation of results of numerical calculations has been provided. This formulation is usefull in the understanding of different intramolecular interactions and explains the sensibility of rate coefficients with respect to dominant interactions
Habiyaremye, Faustin. „Les applications du béton projeté dans les mines souterraines“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0027/MQ38106.pdf.
Der volle Inhalt der QuelleDomergue, Claude. „Les Mines de la péninsule Ibérique dans l'antiquité romaine /“. Rome : Paris : École française de Rome ; diff. de Boccard, 1990. http://catalogue.bnf.fr/ark:/12148/cb35098863z.
Der volle Inhalt der QuelleDubuit, Nicolas Bonhomme Gérard Garbet Xavier. „Transport turbulent d'impuretés dans un plasma magnétisé“. [S.l.] : [s.n.], 2006. http://www.scd.uhp-nancy.fr/docnum/SCD_T_2006_0253_DUBUIT.pdf.
Der volle Inhalt der QuelleLaghdaf, Moulay Ould Mohamed. „Combustion du gaz naturel dans un lit fluidisé“. Doctoral thesis, Universite Libre de Bruxelles, 1990. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213145.
Der volle Inhalt der QuelleSalomé, Quentin. „Interaction jet radio-gaz dans des galaxies proches“. Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEO005/document.
Der volle Inhalt der QuelleMassive galaxies are less abundant than predicted by the standard model of galaxy formation (the Λ-CDM model). This means that galaxies form less stars than expected. To explain this behaviour, it is commonly accepted that some processes are at play and quench star formation. For massive galaxies, it is explained by the feedback of the supermassive black holes. While accreting gas, the central black hole produces energy and momentum. When gas accretion becomes important, the black hole forms an active galactic nucleus, and the energy is expected to quench star formation, via gas heating, turbulence or gas removal (negative feedback). However, evidence is found of so-called AGN positive feedback that favours star formation by compressing the gas. In particular, a fraction of the AGN population produces jets of plasma that are observed in radio emission. These radio jets may interact with gas that is located along the direction of propagation. Such interactions are invoked to trigger star formation (jet-induced star formation). My PhD focused on the jet-gas interaction for nearby radio galaxies. I explored the effect of the jet on the star formation efficiency in such interactions at global (few kiloparsecs) and intermediate (few hundreds parsecs) scales. To do so, I searched and mapped the molecular gas (via CO emission lines) that is a key ingredient for star formation. This cold gas is observable using current radio astronomy ground-based facilities, like ALMA, APEX, NOEMA and the 30m telescope
Leon, Escalante Santos G. „Phénomènes électrofluidodynamiques dans les milieux diphasiques (gaz - solide)“. Poitiers, 2001. http://www.theses.fr/2001POIT2281.
Der volle Inhalt der QuelleGirard, Marianne. „Le gaz ionisé diffus dans les galaxies spirales“. Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/26656.
Der volle Inhalt der QuelleAdvances in astronomical instrumentation allow us to obtain millions of spectra simultaneously over the entire extent of a galaxy with an excellent spatial and spectral resolution. With a high spatial resolution, we find that a large amount of HII regions are surrounded by a component associated to a diffuse ionized gas (DIG). Such observations question theories on the interpretation of emission lines to determinate the parameters of the gas and stellar populations associated to HII regions. To study the DIG, I analyzed data from the integral field spectrograph OASIS of the spiral galaxy NGC 5430. GANDALF software has been used to isolate nebular emission from the stellar absorption. A study of the gas emission and line ratios has been done for HII regions and regions dominated by the DIG. Results show that the DIG can influence diagnosis of HII regions because of strong line ratios that characterize the DIG. To correct this effect, I subtracted a diffuse component representing the DIG in all spectra. After this correction, I obtained weaker line ratios for [NII]/Hα and [SII]/Hα by 5% and 25%, respectively. More pixels show an HII region behavior afterwards. The ages of stellar populations associated to the two main HII regions in the galaxy center, found with the equivalent width of the emission lines Hα and Hβ, are 5:80 ± 0:15 Myr and 4:90 ± 0:25 Myr. The same age is found for cases with and without correction for the DIG, because the DIG has a complementary effect on the calculation of the extinction. I also compared the DIG behavior in NGC 5430 and in the compact group of galaxies HCG 31, an object showing completely different physical conditions.
CHEBBO, MAHER. „Echanges thermiques couples dans un emetteur infrarouge gaz“. Paris, ENMP, 1990. http://www.theses.fr/1990ENMP0230.
Der volle Inhalt der QuelleAguer, Bénédicte. „Comportements asymptotiques dans des gaz de Lorentz inélastiques“. Thesis, Lille 1, 2010. http://www.theses.fr/2010LIL10047/document.
Der volle Inhalt der QuelleWe study the hamiltonian dynamics of free particles in inelastic Lorentz gases, which are environments with an infinite number of degrees of freedom randomly or periodically distributed in space. We exhibit two differents asymptotic behaviours, depending on if the particles undergo dissipation or not.The model is called non-dissipative when the action of the particles on the degrees of freedom of the gas is neglected. We determine, numerically and analytically, the asymptotic behaviour in time of the averaged kinetic energy and the mean squared displacement of fast particles. The analysis is based on the approximation of the particles' dynamics by a random walk where one step corresponds to a unique collision of the particle with a particle of the Lorentz gas. We find different asymptotics, depending on whether the force exerted by the scatterer is or not a gradient field. These results are proved by probabilistic arguments, bringing into play convergence theorems of Markov chains and Bessel processes. We also derive the asymptotic behavior of the main squared displacement in these different cases.In dissipative models, the evolution of the degrees of freedom of the Lorentz gas is affected by the particle and the dynamical system considered is constituted of the particle and the environment. It then has an infinite number of degrees of freedom. We prove, on an appropriate phase space, the global existence of solutions and build a Gibbs measure describing the system's thermodynamic equilibrium. This enables us to prove the Einstein relation at finite time in the presence of an exterior force
Soret, Émilie. „Accélération stochastique dans un gaz de Lorentz inélastique“. Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10054/document.
Der volle Inhalt der QuelleIn this thesis, we study the dynamics of a particle in an inelastic environment composed of scatterer which is commonly known as inelastic Lorentz gas. In the inert case, the environment is not affected by the particle. The kinetic energy of the latter grows with the time and this phenomenon is called « stochastic acceleration ». We approximate the particle's motion by a Markov chain where each step corresponds to a unique collision of the particle with a scatterer. We show that the particle's averaged kinetic energy grows with the time with the exponent 2/5. The result is proved by using probabilistic arguments, bringing into weak convergence theorems of Markov chain as well as the weak convergence of the chain, correctly rescaled in time and space, to a Bessel process.We thus obtain a convergence result for the velocity vector. Under a different rescaling that the one used for the kinetic energy, the latter converges weakly to a spherical brownian motion. In the dynamical case, the evolution of the degrees of freedom of the Lorentz gas is affected by the particle and the dynamical system considered is constitued of the particle and the environment. In such a system, the stochastic acceleration phenomenon cannot be observed. However, we show that the velocity distribution admits a stationnary state
Berthet, Guillaume. „Désordre et interactions dans les gaz quantiques bosoniques“. Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLO010/document.
Der volle Inhalt der QuelleUltracold atoms gases are quantum many-body systems very clean and versatile which allow to study basic concepts of condensed matter in controlled media. In our experimental system, we work with 39 potassium atoms which are bosons and allow us to modify the interactions between atoms using magnetic resonances of diffusion also called Feshbach resonances. Our team is particulary interested in the physics of quantum gases in low dimension in the presence of disorder. First, we present the observation and study of the propagation of bright solitons, which are 1D matter wave with attractive interactions, through a disordered potentiel made from a speckle pattern of light. This study led to the first observation of nonlinear effects over the propagation of cold atoms in disorder. The limits of the experiment, especially in terms of imaging and magnetic field control, motivated the design and construction of a new vacuum chamber. The next part of the manuscript is dedicated to the description and characterization of the new experimental device, from its construction to its use for the production of Bose-Einstein condensates. The last part of this thesis is devoted to the study of Anderson localization of cold atoms in the presence of a constant bias force. Anderson localization is characterized by a suppression of conductivity under the effect of disorder. In the context of the cold atoms, it is explained by taking into account the wave nature of the atoms during the diffusion processes in the disordered medium. Even if localization is always present in 1D systems, theoretical studies predict that a constant force applied to the system drastically modifies the signatures of the localization (algebraic decay of the wave function) and can lead to a complete delocalization of the system. Our experimental study confirms the theoretical predictions
Keita, Seny. „Comportement des gaz dans des ouvrages souterrains fermés“. Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS385.
Der volle Inhalt der QuelleThe deep geological repository is today considered the international reference for radioactive waste management. As part of the feasibility study for such a repository in France, an Underground Research Laboratory has been built by the French national radioactive waste management agency (Andra) in Meuse/Haute-Marne. In this context, gas exchanges and the evolution of air chemistry in underground structures - galleries, micro-tunnels (alveoli) and boreholes - need to be understood. The technological challenge is to continuously monitor a wide range of gaseous molecules at low concentrations in confined spaces. The work in this thesis concerns the behavior of gases in closed underground structures, and is part of this problematic. A gas monitoring station called "Flair soil™" has been developed for continuous, real-time, in situ monitoring of gas composition evolution in several structures, galleries and micro-tunnels in the Bure underground laboratory. The station includes two complementary gas concentration analyzers. i) a quadrupole mass spectrometer, which separates gaseous species in a gas mixture according to their mass (m) to charge (z) ratio. It can be used to monitor the evolution of several gas species, such as light hydrocarbons, noble gases, greenhouse gases, oxygen, hydrogen, nitrogen, carbon monoxide and hydrogen sulfide. ii) an infrared laser spectroscope (Picarro) based on the principle of introducing a gas sample into an optical cavity and determining the optical absorbance of the sample, allowing simultaneous measurement of CO2, CO and CH4 concentrations. After several months of testing and calibration in the underground laboratory, this station was used to monitor the air in a gallery and several closed micro-tunnels. The results of monitoring gas evolution in an underground gallery over a period of 4 months have highlighted different gas evolutions according to two periods: i) a period when the galleries are ventilated and there is significant human activity (working days) and ii) a period when the galleries are not ventilated and there is no human activity (weekends, holidays and/or vacations). These observations highlight the sources and sinks of three gases (CO2, CO and CH4) in these structures. In fact, the gases can be consumed or produced by several processes occurring in the Underground Research Laboratory, such as the degassing of CO, CO2 and CH4 from the pore water in the rock, the supply by ventilation and production by human activity, the production of CO or CO2 in the exhaust gases of internal combustion engines, and the consumption of CO2 by the carbonation of concrete. Gas monitoring in micro-tunnels supplements information on gas exchange between rock, atmosphere and steel casing. Here, levels of a few ppm of dihydrogen produced by anoxic corrosion of the steel were detected. Monitoring gas composition in the Meuse/Haute-Marne underground laboratory reveals complex processes affecting gas species in galleries and micro-tunnels. Our results show that gas exchanges with the Callovo-Oxfordian and the materials present play an important role in understanding the overall gas balance. The cementitious materials act as a CO2 sink, while the clay rock is a source of CO2, CO and CH4. Thanks to this monitoring, the presence of CO in these underground structures has been quantified for the first time. However, we still need to refine our understanding of how this gas is produced and consumed in this context
Mukherjee, Mainak. „Caractérisation des phénomènes de transport de gaz dans les couches de diffusion de gaz dans une pile à combustible à membrane“. Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0176.
Der volle Inhalt der QuelleIn membrane fuel cells, the feed gas must pass through a porous layer of carbonaceous material (GDL, gas diffusion layer) to access the catalyst, enabling the electrochemical reaction and subsequent energy production. In general, this layer consists of a macroporous substrate (MPS) covered by a thinner structural undercoat called a microporous layer (MPL) in contact with the electrode. The project here focuses on the study of gas transport phenomena in commercially available diffusion layers, which are essentially complex porous media (MPL+MPS). GDLs have a key role in the distribution of gases and the evacuation of produced water: in addition to diffusion and convection, the intrinsic properties of these layers are known to play a significant role on the overall performance of the fuel cell. The present approach relies on various sources of experimental observations to understand and characterize these transport flows in GDL in order to obtain a phenomenological formalism. To this end, ex-situ measurements using a "diffusion bridge" technique are carried out in a laboratory cell (called a fundamental cell) to estimate the directional permeability of the gas or in a fuel cell to estimate the equivalent permeability under conditions closer to cell operation. Essentially, the conditions for measuring gas transport have been modified, using (i) a single dry gas, (ii) a mixture of dry gases, (iii) humidified gases, (iv) gas flow in the presence of liquid water, and (v) variable cell compression. The results obtained on gas permeability, first through experimentation and then by using the data in established fundamental models, provide more precise information on the gas transport mechanism in these complex-structured GDLs when placed inside PEM fuel cells, leading to a significant understanding
APPERT, CECILE. „Transition de phase dynamique de type liquide-gaz et creation d'interfaces dans un gaz sur reseau“. Paris 6, 1993. http://www.theses.fr/1993PA066012.
Der volle Inhalt der QuelleAltimiras, Martin Carles Oriol. „Mécanismes inélastiques dans des circuits mésoscopiques réalisés dans des gaz bidimensionnels d'électrons“. Paris 11, 2010. http://www.theses.fr/2010PA112338.
Der volle Inhalt der QuelleThis thesis presents an experimental investigation of inclastic interaction effects in mesocopic circuits, realized in two dimensional electron gases. We explore the regimes of the integer and fractional quantum Hall effect, and the interactions between a coherent conductor and the circuit in whish it is embedded. We investigate the quantum Hall regimes under the point of view of energy transport. We demonstrate the non-equilibrium spectroscopy of th electronic energy distribution of an edge channel, using a quantum dot as an energy filter, while the edge channel is driven out of equilibrium with a voltage biased quantum point contact. With these tolls, we probe the non equilibrium dynamics along two co-propagating edge channels (nu=2). We observe a strong energy relaxation, challenging the widespread picture of non-interacting channels, and identify inter-channelinteractions, without particleexchanges, as the dominant inclastinc mechanism. We further demonstrate two techniques permitting us to increase, and freeze, the energy relaxation. Similar experiments performed in the fractional regime at nu=4/3, reveal an antichiral energy flow , while the electric current is found to follow the expected chirality. Weshow that the antichiral energy flow is carried by neutral bulk excitations. The impedance of coherent conductor is modified by its environment, modifying the usual impedance composition laws. This effect, know as dynamical Coulomb blockade, has been predicted to be renormalized by the Fano factor emerging in the conductorés shot noise. We demonstrate this strag link by measuring the condtance of aquentum point contact embedded in a tunable circuit
Dubuit, Nicolas. „Transport turbulent d'impuretés dans un plasma magnétisé“. Nancy 1, 2006. http://docnum.univ-lorraine.fr/public/SCD_T_2006_0253_DUBUIT.pdf.
Der volle Inhalt der QuelleThe turbulent impurity transport is an essential issue for the achievement of magnetically confined fusion. Indeed, a build-up of impurities in the plasma core induces radiation energy losses. On the other hand, it is foreseen to inject impurities at the plasma edge in order to extract heat by radiation. These conditions impose control and therefore understanding of impurity transport. An analytical expression for the turbulent flux of impurities for a given turbulent spectrum have been derived using a quasilinear theory applied to a drift-wave turbulence. The nature and characteristics of the main accumulation (or pinch) mechanisms for impurities have been identified. A new version of the fluid turbulence code TRB has been developed. This version allows simulating the transport of impurities in electronic and ionic drift-wave turbulence. Zero-flux simulations, corresponding to a stationnary plasma whose impurity source is limited to the plasma edge, confirmed the presence of an impurity pinch. Quasilinear predictions have been numerically confirmed, and the relative importance of the various pinch mechanisms has been studied. The dominant role of curvature pinch has been shown. Finally, simulations have been compared to experimental measurements made on JET and Tore Supra tokamaks. The presence of a turbulent pinch of impurities has been confirmed, as well as the independence of transport on impurity charge
Holzmann, Markus. „La transition de Bose-Einstein dans un gaz dilué“. Phd thesis, Université Pierre et Marie Curie - Paris VI, 2000. http://tel.archives-ouvertes.fr/tel-00011774.
Der volle Inhalt der QuellePapoular, David. „Manipulation des interactions dans les gaz quantiques : approche théorique“. Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00624682.
Der volle Inhalt der QuelleLange, Sébastien. „Variabilité spatiale du mouvement de gaz dans le sol“. Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26063/26063.pdf.
Der volle Inhalt der QuelleDhima, Aleksandër. „Solubilité des gaz naturels dans l'eau à pression élevée“. Lyon 1, 1998. http://www.theses.fr/1998LYO19002.
Der volle Inhalt der QuelleGuivarch, Bruno. „Ecoulement du gaz dans le disque des galaxies barrées“. Aix-Marseille 1, 1997. http://www.theses.fr/1997AIX11028.
Der volle Inhalt der QuelleAmram, Philippe. „Etude cinématique du gaz ionisé dans les galaxies spirales“. Aix-Marseille 1, 1991. http://www.theses.fr/1991AIX11376.
Der volle Inhalt der QuelleEssayem, Fayçal. „Transfert thermique dans les milieux gaz-liquide agités mécaniquement“. Aix-Marseille 3, 1987. http://www.theses.fr/1987AIX30091.
Der volle Inhalt der QuelleVillain, Pierre. „Effets de statistique quantique dans les gaz d'atomes refroidis“. Paris 6, 2000. http://www.theses.fr/2000PA066473.
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