Teses / dissertações sobre o tema "Formation stellaire – Modèles mathématiques"
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Bruel, Tristan. "Les coalescences de trous noirs à l'interface de la formation stellaire globale et de l'évolution stellaire". Electronic Thesis or Diss., Université Côte d'Azur, 2024. http://www.theses.fr/2024COAZ5054.
Texto completo da fonteMore than a hundred binary black hole (BBH) merger candidates have now been reported by the LIGO-Virgo-KAGRA (LVK) Collaboration after their first three series of observations and during the current O4 run. Physical properties of these tight pairs of compact objects merging in the local Universe are becoming increasingly well constrained. However, the question of their astrophysical origin and the nature of the dominant mechanisms behind their formation has yet to be fully answered. The two main scenarios generally put forward to explain the existence of these systems are, on the one hand, a series of interactions between two massive stars in a binary system and, on the other, a large number of dynamical interactions between stars and black holes in star clusters. The relative contribution of each of these two channels to the overall population is still unknown. While in recent years a number of studies have focused on either one or the other scenario, it is extremely challenging to model them together and in a consistent way within a cosmological context.During my thesis, I focused on this question and sought to constrain the different properties of BBHs that result from the isolated evolution of stellar binaries and those that form in massive star clusters. To this end, I use cosmological simulations as realistic environments in which the formation of stars and of star clusters across cosmic time can be modelled consistently for the first time. I first present some predictions of binary stellar evolution leading to the formation of merging BBHs using the rapid binary population synthesis code COSMIC. Combined with simplified analytic models of star formation, I am able to produce synthetic populations of BBHs that can be compared with LVK observations. By adopting different hypotheses on the binary evolution of massive stars and on the formation rate density of stars in the Universe, I find that the uncertainties on these two aspects are still too large to constrain the formation environment of these systems in a robust way.With regard to the dynamical formation of BBHs, I have joined an international collaboration and developed a project to study the formation and evolution of massive star clusters in cosmological simulations of individual galaxies with a wide range of present-day physical properties. Using the properties of the giant molecular clouds present in each simulated galaxy associated with a cluster formation model built consistently, I am able to produce the very first populations of realistic star clusters formed in various galaxies across cosmic time. The massive star clusters are integrated forward in time with the code for cluster evolution CMC, taking into account their interactions with the galactic surrounding. By examining the merging BBHs formed dynamically in these dense environments, I am able to identify some of their physical properties that could help identify the formation channel of the most massive BBH mergers observed by LVK. I also find strong correlations between local peaks in the BBH merger rate, recent formation of massive star clusters, and intense episodes of star formation, sometimes linked to interactions between galaxies or even to galaxy mergers.Finally, I extend this method built on simulations of individual galaxies to a cosmological volume simulation containing thousands of galaxies. I find that massive Milky Way-like galaxies, despite their low number compared to the numerous low-mass dwarf galaxies, have the larger contribution to the overall population of merging BBHs formed dynamically in massive star clusters. By using jointly the rapid code for binary evolution COSMIC and the code for cluster evolution CMC applied to stellar binaries and star clusters located within a common cosmological simulation, I create a common framework to study the formation of merging BBHs following the two aforementioned channels in the most consistent way
Couture, Pierre. "Galaxies à sursauts de formation stellaire : Simulations pour la mission UVIT". Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/28432/28432.pdf.
Texto completo da fonteMarseille, Matthieu. "Observations et modélisations de proto-étoiles massives dans le cadre des observatoires Herschel". Thesis, Bordeaux 1, 2008. http://www.theses.fr/2008BOR13658/document.
Texto completo da fonteToday the formation of massive stars is still not well understood due to the huge interac- tion of these objects with their environment, leading to a theoretical limit in the ?nal mass that observations contradict. The future observatories, like the Herschel Space Observatory, will try to answer some of the questions linked to this topic, particularly through the water line emissions. The correct and precise analysis of the future data is then necessary and needs a full work linking the observations and the modelling of the objects that will be studied. Hence the main goal of this PhD Thesis was to elaborate a robust and global modeling method of the massive dense cores in which high-mass stars are forming. The method leaded to a physical description and a chemical study of multiple massive dense cores, opening new views on evolution aspects. In addition it gave some tweaks on the guaranteed-time key program WISH for the water line emissions and con?rmed the key role of this molecule for a better understanding of the high-mass star formation
Côté, Benoit. "Modèle de vents galactiques destiné aux simulations cosmologiques à grande échelle". Master's thesis, Université Laval, 2010. http://hdl.handle.net/20.500.11794/22281.
Texto completo da fonteAlibert, Yann. "De la physique stellaire à la physique galactique : formation, évolution et pulsations stellaires. Modèles galactiques". Lyon, École normale supérieure (sciences), 2002. http://www.theses.fr/2002ENSL0191.
Texto completo da fonteDuhamel, Jean. "Effets diffusionnels dans la formation d'excimères intermoléculaires". Vandoeuvre-les-Nancy, INPL, 1989. http://www.theses.fr/1989NAN10401.
Texto completo da fonteMeliani, Salha. "Etude asymptotique et numérique d'un modèle thermo-chimique de formation d'un matériau composite". Saint-Etienne, 2003. http://www.theses.fr/2003STET4009.
Texto completo da fonteWe consider a composite material constituted of carbon or glass fibres included in a resin which becomes solid when it is heated up (reaction of reticulation). The mathematical modelling of the cure process is given by a kinetic equation describing the evolution of the reaction of reticulation coupled with the heat eqaution. The geometry of the composite material is periodic, with a small period E > 0. First we prove the existence and uniqueness of a solution by using Schauder's fixed point theorem. Then, by using an asymptotic expansion, we decrive the homogenized problem which describes the macroscopic behaviour of the material. We prove the convergence of the solution of the problem to the solution of the homogenized problem when E tends to zero and we obtain an error estimation in a case of weak non-linearity. Finally we solve numerically the homogenized problem
Bagot, Philippe. "Modèles de formation de systèmes doubles d'étoiles à neutrons". Montpellier 2, 1996. http://www.theses.fr/1996MON20178.
Texto completo da fonteLi, Jianfei. "Modélisation de la formation des contraintes résiduelles dans les dépôts élaborés par projection thermique". Besançon, 2006. http://www.theses.fr/2005BESA2061.
Texto completo da fonteThermal spray processes consist in elaborating a coating on a workpiece in order to protect it against corrosion, wear or thermal fluxes for example. Since the coatings are formed by the flattening and solidification of molten droplets sprayed on the surface, they are affected by residual stresses during their elaboration. This study is devoted to the modelling of the residual stresses formation during the coating elaboration. These stresses have two major contributions: - quenching stresses appearing during the flattening, solidification and cooling of individual splats. - thermal stresses appearing during the workpiece overall cooling down. The finite element SYSWELD software was used in the present study. It is specialized in the modelling of stresses induced during welding applications. Since thermal aspects play an important role in the formation of stresses for thermally sprayed coatings, they were first considered. The influence of thermal fluxes transferred to different shape workpieces using different trajectories is hence first presented. Moreover, the stresses formation modelling is presented in the last chapter. The cases of alumina and molybdenum coatings sprayed on a steel substrate are considered. Numerical results show that the overall residual stress level may be modified by using cooling devices during the coating elaboration
Combet, Céline. "Etude analytique et numérique des flots autour des étoiles jeunes". Phd thesis, Université Paris Sud - Paris XI, 2006. http://tel.archives-ouvertes.fr/tel-00090716.
Texto completo da fonteLorsqu'une étoile se forme, alors que l'accrétion sur l'objet central se poursuit, de gigantesques éjections de matière se produisent sous forme de jets et flots moléculaires bipolaires. Après une
introduction donnant une vision globale de tous les éléments
impliqués dans la formation stellaire, nous présentons les modèles "standards" pour les flots moléculaires. Dans un
troisième temps, nous construisons un modèle alternatif et complémentaire aux approches standards~: le modèle de transit. Il s'agit d'un modèle MHD, autosimilaire et qui considère le renversement d'un partie de l'écoulement lorsque le gaz en chute
approche de l'objet central. Les résultats montrent notamment que le modèle permet de rendre compte des taux de masses observés lors de la formation des étoiles massives, taux que les modèles standards atteignent difficilement. Le modèle est étudié de façon
extensive grâce à une exploration Monte Carlo de l'espace des paramètres et la mise en évidence de deux grandes familles de solutions. Le modèle de transit donne une description à grande échelle de l'environnement proto-stellaire et montre une forte structuration du milieu autant en densité qu'en vitesse. C'est dans un tel milieu que le jet issu du disque d'accrétion se propage, et une étude numérique préliminaire de cette propagation montre que la morphologie et la cinématique du jet est fortement affectée par le milieu ambiant. Nous en déduisons l'importance d'avoir un bonne description de ce dernier et la nécessité de ne pas se contenter des milieux "uniformes et au repos" généralement considérés.
La seconde partie est consacrée à la partie nucléaire du rayonnement cosmique Galactique. Ce "rayonnement" est constitué de noyaux qui se sont propagés dans la Galaxie et son halo diffusif, après avoir été accélérés dans les chocs de supernovae. Certains de ces noyaux atteignent la Terre où ils
sont détectés. Comprendre la propagation de ces noyaux est essentiel pour remonter, à partir des mesures, aux abondances des noyaux dans les sources. Dans ce travail, nous nous intéressons spécifiquement au cas des noyaux lourds, en connection avec l'expérience UHCRE, et regardons comment la structure locale de la Galaxie, la "bulle locale", affecte la propagation des lourds. Nous trouvons que la sous-densité locale du voisinnage solaire joue effectivement un rôle dans la détermination des abondances sources et que l'effet tend à réduire les différences entre les abondances sources et les abondances solaires des noyaux. Nous donnons enfin dans un dernier chapitre quelques perspectives pour la poursuite de cette étude.
Teutsch, Philippe. "Environnements interactifs et langues etrangeres, marple : systeme d'evaluation et de suivi de formation". Le Mans, 1994. http://www.theses.fr/1994LEMA1003.
Texto completo da fonteFaye, Grégory. "Symmetry breaking and pattern formation in some neural field equations". Nice, 2012. http://www.theses.fr/2012NICE4017.
Texto completo da fonteThe aim of this Thesis is to give a deeper understanding of pattern formation in neural field equations with symmetry, and to understand the significance of these symmetries in modelling the visual cortex. Neural fields equations are mesoscopic models that describe the spatio-temporal activity of populations of neurons. They were introduced in the 1970s and are often called the Wilson-Cowan-Amari equations in reference to their authors. From a mathematical point of view, neural fields equations are integro-differential equations set on domains particular to the modelled anatomical / functional properties. The first part of the Thesis is an introduction to mesoscopic modelling of the visual cortex and presents a model of the processing of image edges and textures. The second part is dedicated to the study of spatially periodic solutions of neural field equations, in different geometries, with applications to visual hallucination patterns. The results developed are general enough to be applied to other pattern formation problems. Finally, the last part is centred on the study of localized solutions of neural field equations set on unbounded domains
Pinsonneault, Steve. "Enrichissement chimique du milieu intergalactique par des vents galactiques anisotropes". Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/28775/28775.pdf.
Texto completo da fontePujet, Stéphane. "Modélisation de l'écoulement autour d'une bulle de vapeur en formation sur une paroi chauffante en ébullition convective sous-saturée". Toulouse, INPT, 1998. http://www.theses.fr/1998INPT028H.
Texto completo da fonteOblin, Magali. "Etude expérimentale et théorique de la réaction de cycloaddition [2+2] catalysée par un acide de Lewis : formation des cétènes". Aix-Marseille 3, 1997. http://www.theses.fr/1997AIX30104.
Texto completo da fonteMoulet, Lucie. "Modélisation de l'apprenant avec une approche par compétences dans le cadre d'environnement d'apprentissage en ligne". Paris 6, 2011. http://www.theses.fr/2011PA066636.
Texto completo da fonteLebedev, Nikolaï. "Terminaux multicapteurs pour communications par satellite : techniques de formation de voies en émission et capacité". Nantes, 2003. http://www.theses.fr/2003NANT2031.
Texto completo da fonteMontavon, Ghislain. "Etude expérimentale et modélisation heuristique de la formation d'un dépôt en projection thermique : : application à la mise en forme par projection thermique". Besançon, 1995. http://www.theses.fr/1995BESAA001.
Texto completo da fontePech, David. "Astérosismologie des étoiles ZZ ceti". Toulouse 3, 2005. https://tel.archives-ouvertes.fr/tel-00010095.
Texto completo da fonteThis thesis shows how far asteroseismological techniques, relying on observation and modeling, allow to derive the structural properties of a DAV white dwarf, especially how it becomes possible to deduce the mass of the remaining hydrogen envelope in the star. Two ZZ Ceti stars were studied : HL Tau 76 (located on the red edge of the instability strip) and G 185-32 (on the blue edge). Modeling indicates that the hydrogen envelopes in these stars have nearly the same mass: M(H)= 2. 0 (±0. 3) x 10e-4 MÔ. This result may suggest a possible constancy for the hydrogen layer mass among the DA stars class and consequently prospective constraints for cosmochronology and stellar evolution. Moreover, this thesis illustrates how far modeling might reveal some physical features such as a non-uniform stellar rotation, a non-linear coupling between resonant modes, an interaction between pulsations and convection
Nóbrega, Germana Menezes da. "Une approche dialectique à la formation de théories : aspects conceptuels, formels et pragmatiques dans le cadre de l'apprentissage humain". Montpellier 2, 2002. http://www.theses.fr/2002MON20096.
Texto completo da fonteBoco, Hervé. "Modèles de dynamique des prix sur les marchés financiers et processus de formation de bulles spéculatives". Toulouse, ISAE, 2010. http://www.theses.fr/2010ESAE0011.
Texto completo da fonteNguyên, Viêt-Hai. "Formation interactive, expérimentation à distance, partage des ressources : application : automatique et ingénierie de l'environnement". Saint-Etienne, EMSE, 2009. http://www.theses.fr/2009EMSE0035.
Texto completo da fonteThe surface treatments industry uses a lot of complex processes and toxic substances. It subjects to different regulations which are strict and limiting quantities of rejected pollutants in the nature. It is always difficult for industrials to comply to these regulations because of a more and more cutthroat competition. Thereof, this economic sector is naturally considered as a rich suggestion box for researchers. The diversity of used processes asks competences, knowledge and approaches from different fields. In the frame of this thesis, our works have focused on the rinsing system and the wastewater detoxication plants: decyanidation and dechrommation. Thanks to different approaches, these processes have been modeled and a simulation tool has been developed. Such a tool could answer to a lot of needs. It will be possible for industrials to optimize processes in taking into account different factors as cost, productivity as well as environmental impacts. In the engineering formation, i twill be easier for students to understand how industrial processes work and to familiarize with industrial constraints
Caroli, Eve. "Formation, institutions et croissance économique". Paris, Institut d'études politiques, 1995. http://www.theses.fr/1995IEPP0013.
Texto completo da fonteThe thesis proposes an institutional analysis of the influence of education and training (E&T) on economic growth in a cross-section of countries. We first modelize the E&T - growth relationship in several countries which differ widely as far as their level of development is concerned. In order to do so, we use an endogenous growth framework and we propose a very simplified modelization of the institutions governing E&T at the national level. We then turn to the study of five oecd countries. In this case, a quite detailed analysis of E&T institutions appears to be necessary. This analysis allows us to define precisely the content of the e&t-growth relationship before modelizing it in a kaldori an framework. Eventually, we propose a dynamical model of on going collective action in order to study the conditions for a wide in-firm training system to emerge in the United-States
Vidal, Thomas. "Revisiting the chemistry of star formation". Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0151/document.
Texto completo da fonteAstrochemical studies of star formation are of particular interest because they provide a better understanding of how the chemical composition of the Universe has evolved, from the diffuse interstellar medium to the formation of stellar systems and the life they can shelter. Recent advances in chemical modeling, and particularly a better understanding of grains chemistry, now allow to bring new hints on the chemistry of the star formation process, as well as the structures it involves. In that context, the objective of my thesis was to give a new look at the chemistry of star formation using the recent enhancements of the Nautilus chemical model. To that aim, I focused on the sulphur chemistry throughout star formation, from its evolution in dark clouds to hot cores and corinos, attempting to tackle the sulphur depletion problem. I first carried out a review of the sulphur chemical network before studying its effects on the modeling of sulphur in dark clouds. By comparison with observations, I showed that the textsc{Nautilus} chemical model was the first able to reproduce the abundances of S-bearing species in dark clouds using as elemental abundance of sulphur its cosmic one. This result allowed me to bring new insights on the reservoirs of sulphur in dark clouds. I then conducted an extensive study of sulphur chemistry in hot cores and corinos, focusing on the effects of their pre-collapse compositions on the evolution of their chemistries. I also studied the consequences of the use of the common simplifications made on hot core models. My results show that the pre-collapse composition is a key parameter for the evolution of hot cores which could explain the variety of sulphur composition observed in such objects. Moreover, I highlighted the importance of standardizing the chemical modeling of hot cores in astrochemical studies. For my last study, I developed an efficient method for the derivation of the initial parameters of collapse of dark clouds via the use of a physico-chemical database of collapse models, and comparison with observations of Class 0 protostars. From this method, and based on a sample of 12 sources, I was able to derive probabilities on the possible initial parameters of collapse of low-mass star formation
Nolin, Simon. "Modélisation "Smoothed Particle Hydrodynamics" de la formation d'un embâcle fluvial et de son relâchement". Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25273/25273.pdf.
Texto completo da fonteCesari, Giulia. "Modèles de théorie des jeux pour la formation de réseaux". Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLED046/document.
Texto completo da fonteThis thesis deals with the theoretical analysis and the application of a new family of cooperative games, where the worth of each coalition can be computed from the contributions of single players via an additive operator describing how the individual abilities interact within groups. Specifically, we introduce a large class of games, namely the Generalized Additive Games, which encompasses several classes of cooperative games from the literature, and in particular of graph games, where a network describes the restriction of the interaction possibilities among players. Some properties and solutions of such class of games are studied, with the objective of providing useful tools for the analysis of known classes of games, as well as for the construction of new classes of games with interesting properties from a theoretic point of view. Moreover, we introduce a class of solution concepts for communication situations, where the formation of a network is described by means of an additive pattern, and in the last part of the thesis we present two approaches using our model to real-world problems described by graph games, in the fields of Argumentation Theory and Biomedicine
Li, Huxi. "Formulation des mélanges de polymères dans un mélangeur interne : développement d'un nouveau procédé de fabrication d'un copolymère greffé et étude de ses rôles dans la formation et la stabilisation de la morphologie". Vandoeuvre-les-Nancy, INPL, 2000. http://www.theses.fr/2000INPL079N.
Texto completo da fonteMartin, Emmanuel. "Etude et modélisation de la formation et de la croissance des aérosols organiques secondaires d'origine biogène". Université Louis Pasteur (Strasbourg) (1971-2008), 2001. http://www.theses.fr/2001STR13195.
Texto completo da fonteGayet, Pascal. "Formation/dissociation d'hydrates de gaz en milieu poreux : effet de la capillarité sur les conditions d'équilibre P/T". Pau, 2005. http://www.theses.fr/2005PAUU3011.
Texto completo da fonteGas hydrates are solid compounds that could be used as a thermal tracer for the oil or gas fields they recover. In order to do it, the P/T equilibrium conditions must be known accurately in porous medium. The work presented in this report is a contribution to the study of these conditions. Two experimental set-ups were built up. The first one, provided with a transparent cell, allows to visualize and measure equilibrium conditions of gas hydrates up to 0. 5 MPa. The second one, provided with a cell without any windows, allows to measure equilibrium conditions of gas hydrates up to 60 MPa. We checked that, in a bulk system, the use of a surfactant (SDS) accelerated hydrate formation. Their equilibrium conditions, measured and calculated, were in good agreement with literature data in the ranges 0. 2 – 0. 5 MPa for propane hydrate and 3 – 20 MPa for methane hydrate. We determined equilibrium conditions of methane hydrate, experimentally and theoretically, between 20 and 53 MPa, which completed literature data. We also checked that only mesoporous media (silica gels, clay) had an influence on equilibrium conditions of gas hydrates. They are shifted to lower temperatures and higher pressures and the smaller the mesopores, the higher the shift. On the basis of a modified van der Waals and Platteeux model, we demonstrated that shifts depended on the pore size distribution of the mesoporous systems
Farkhutdinov, Anvar. "Les eaux géothermiques du gisement Khankala ˸ formation, utilisation, prévisions". Electronic Thesis or Diss., Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEM092.
Texto completo da fonteRecently, considerable attention in the world is given to the use of renewable energy sources. Among them geothermal waters are of great importance due to ecological safety and economic efficiency of their use. Russia has confirmed high potential of geothermal water resources, but today only a small proportion is used. One of the most promising areas for geothermal waters is the Chechen Republic, which is at the 3rd place among the Russian regions for approved operational reserves of geothermal waters deposits, the largest of which is the Khankala deposit.Achievement of the sustainability in geothermal waters resource development requires an integrated approach and an important role in solving the problems of exploitation of thermal waters is played by geostatistical analysis and estimation, as well as mathematical modelling. The adjusted structural map of the most productive layer (layer XIII) and a 3-D map of temperature distribution within the Khankala deposit were created using universal kriging. Results approved the importance of the structural-tectonic factor and movement of groundwater in the formation of the temperature regime of the territory. Modelling of the Khankala geothermal waters deposit exploitation allowed to make prognosis of temperature changes, to provide recommendations on injection-production wells location and distance between down holes and to explore possible further exploitation scenarios such as periodic use of different layers by doublet systems.The development of geothermal waters use has undoubted advantages – environmental friendliness and renewability. In order to develop this domain in the Chechen Republic the state support is needed. Issues are the lack of a special legislative framework and special insurance systems. Use of geothermal waters of the 14 explored deposits in Chechen Republic can be a significant contribution to local energy production and economic stability of the region while bringing the environmental benefits of traditional fuels partial replacement.The present work was a contribution to the Khankala geothermal station project, which was successfully launched in the beginning of the 2016. The Khankala geothermal station represents a new stage in use of geothermal waters in the Northern Caucasus as it is the only Russian example of geothermal station with closed loop of production and injection wells (“doublet”) with 100% reinjection of used fluid back into reservoir
Reche, Tamayo Manuel. "Using computational methods to rationalize organogel formation". Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS464.
Texto completo da fonteThis work deals with supramolecular organogels. These gels are obtained by dispersing in the organic solvent low molecular weight molecules (Low Molecular Weight Gelators, LMWGs), which are not soluble at room temperature and form a suspension. This suspension is heated, achieving solution, and cooled down back to room temperature where LMWG molecules self-assemble in non-covalently bonded Self-Assembled Fibrillar Networks (SAFiNs), e.g., by hydrogen-bonding, π-stacking, Van der Waals interactions, etc. This entangled network traps mechanically the liquid, principally by surface tension, trigger-ing a gel state. A precise description of the phenomena remains partially unknown, leaving open questions that still impede to predict beforehand whether a given LMWG candidate will be able to gelate a certain liquid of interest. If design rules could be established between the chemical structure of a LMWG and its gelation properties, it could be possible to design LMWGs for specific liquids of interest while providing insight about organogel formation. Thus, this work investigates sets of chemically diverse LMWG families, with the aim of correlating their chemical structure with their corresponding gelation behavior. The approach followed in this thesis consists in modelling the self-assembly of different series of LMWGs, bisamide-cyclohexane compounds and thiazole compounds with alkyl chains of different lengths, with the aim of understanding the formation of the gel fibers and determining their structure. Most of the LMWGs that we have studied crystallize to form gels, and for such crystalline systems, our methodology starts with a Crystal Structure Prediction (CSP) of the gel fibers, combining crystal cell generation and powder X-ray diffraction simulations. Then, we determine their crystal morphology using growth kinetics principles, to finally characterize the gelation ability of the gel fibers using surface energy parameters. Our modelling activities have been carried out in very close interaction with corresponding experimental efforts undertaken in the groups of Prof. Laurent Bouteiller (Sorbonne Université) and Prof. Pierre-Antoine Albouy (Université Paris-Sud). Their results of gelation experiments, powder X-ray diffraction and SEM characterization were compared with our modelling data
Laroussi, Mostéfa. "Simulation de la croissance hétéroépitaxique multicouche : formation des amas et défauts étendus". Toulouse 3, 1990. http://www.theses.fr/1990TOU30211.
Texto completo da fonteCaplain, Isabelle. "Mesure des émissions polluantes automobiles : application à la modélisation eulérienne 3D de la formation des oxydants photochimiques dans la troposphère". Lille 1, 2005. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2005/50376-2005-Caplain.pdf.
Texto completo da fonteÀ partir de la répartition des polluants sur la région suivant ce cadastre, les données obtenues ont servi de données d'entrées pour un modèle de simulation physicochimique de la troposphère (UAM Urban Airshed Model). Une étude précédemment menée, portant sur l'introduction de la spéciation moléculaire détaillée des COV et l'utilisation du mécanisme CBIV n'a pas donné de résultats concluants quant à l'impact de cette spéciation sur la formation d'ozone. Nous souhaitions par l'introduction d'un nouveau mécanisme avoir une prise en compte meilleure de l'ensemble de ces composés et voir ainsi leur contribution éventuelle sur la formation d'ozone sur notre domaine. Ceci nécessitait une adaptation du modèle et notamment l'installation d'un module (interface FCM = Flexible Chemical Mecanism) permettant l'introduction d'un nouveau mécanisme chimique (SAPRC 99 au lieu du CBIV) au sein même du modèle. L'ensemble des fichiers d'entrées a été adapté pour la prise en compte de la totalité des composants. L'influence de la spéciation des COV sur la formation d'ozone sur un épisode de simulation a été ensuite étudiée avec une augmentation de la concentration d'ozone calculée aux stations et un pourcentage moyen d'écart sur la formation d'ozone de l'ordre de 28% par rapport aux calculs avec le précédent mécanisme
Chrit, Mounir. "Formation des aérosols organiques et inorganiques en Méditerranée". Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1027/document.
Texto completo da fonteThis work aims at understanding the origins and processes leading to the formation of organic aerosols (OA) and inorganic aerosols (IA) over the western Mediterranean Sea during different seasons, using the air-quality model Polyphemus. In the framework of ChArMEx (the Chemistry-Aerosol Mediterranean Experiment), measurements of both aerosol concentrations and properties are performed at a remote site (Ersa) on Corsica Island in the northwestern Mediterranean sea in the summers 2012, 2013 and the winter 2014. This thesis also benefits from measurements performed during flights above the western Mediterranean Sea in the summer 2014. The model is evaluated during these periods, and different processes/parameterizations are added or modified in order to have good model-to-measurements comparisons, not only of aerosol concentrations but also of their properties. Origins of aerosols are assessed through different sensitivity studies to the meteorological model, anthropogenic emissions inventory, sea-salt emissions and different input models. The contribution of marine emissions to inorganic aerosols (IA) is important, and the parameterization of sea-salt emissions is chosen such as having good comparisons to sodium measurements, which is a non-volatile compound emitted mainly by sea salts. Marine organic aerosols (OA), which are added to the model with a parameterization that uses the chlorophyll-a concentration as a proxy parameter to model the marine chemistry, contribute to OA by only 2% at the maximum. The ground-based and airborne model-to-measurements comparisons show the importance of an accurate description of shipping emissions to model sulfate and OA concentrations. However, this is not true for nitrate and ammonium concentrations, which are very dependent on the hypotheses used in the model for condensation/evaporation (thermodynamic equilibrium, mixing state).During the summers 2012 and 2013, OA concentrations are mostly of biogenic origin, which is well reproduced by the model. Measurements show important concentrations of highly oxidized and oxygenated OA. For the model to reproduce not only the concentrations but also the oxidation and hydrophilicity properties of OA, three processes to form secondary organic aerosols (SOA) from monoterpenes are added to the model : the autoxidation process leading to the formation of extremely low volatility organic compounds, the organic nitrate formation mechanism and the second generational ageing. The high oxidation and oxygenation states of OA at Ersa are well modeled when organosulfate formation is also assumed. Winter simulations show that OA are mainly of anthropogenic origin. The influence of the anthropogenic intermediate/semi-volatile organic compound (ISVOC) emissions, which are missing from emission inventories, is low in summer. Nonetheless, the role and the contribution of ISVOC appear very significant during the winter, with a large contribution from residential heating. Different parameterizations to represent the emissions and the ageing of IS-VOC are implemented in the model, namely the volatility distribution of emissions, single-step vs multi-step oxidation scheme and non-traditional volatile organic compounds (NTVOC) chemistry. Sensitivity studies show that the volatility distribution at the emission is a key parameter to improve the modeling of OA concentrations. The model reproduces well the observed concentrations, but the observed organic oxidation and oxygenation states are strongly under-estimated, stressing the potential role of autoxidation and organic nitrate from anthropogenic precursors
Rives, Thierry. "Mécanismes de formation des diaclases dans les roches sédimentaires : approche expérimentale et comparaison avec quelques exemples naturels". Montpellier 2, 1992. http://www.theses.fr/1992MON20191.
Texto completo da fonteRoussel, Céline. "Interconnexions en cuivre d'architecture damascène : modélisation du polissage mécano-chimique (P.M.C.) et étude du phénomène de formation de cavités dans le cuivre". Bordeaux 1, 2003. http://www.theses.fr/2003BOR12678.
Texto completo da fonteThe fabrication of intagrated circuits requires a control of material planarization. Thus Chemical Mechanical Polishing (CMP) process appears necessary to planarize, to reveal and insulate copper interconnections, and to optimize electrical performance and fabrication cost. The aim of this study is to characterize, to build a model of copper planarization, evolution of dishing copper lines and érosion diélectric lines after CMP, and then to propose design rules. Moreover, electromigration and stress-induced voiding are becoming key issues to determine the reliability of copper dual damascene metallization of integrated circuits. However, stress voiding has been observed in the copper lines after their fabrication. Therefore, copper voids and materials of interconnects have been characterized. In addition, mechanical stress distribution and volume dilatation in a copper line are determined. This résults brings to light the probable cause of these void in the copper line
Nguyen, Thi Thanh Xuan. "Etude physico-chimique de la formation et de l'évolution des particules dans la ligne d'échappement des véhicules : Modélisation et expérimentation". Université Louis Pasteur (Strasbourg) (1971-2008), 2005. http://www.theses.fr/2005STR13173.
Texto completo da fonteBalasque, Jean-Michel. "Contribution à l'analyse de l'influence de l'image de l'entreprise fournisseur sur la formation des préférences en milieu industriel". Bordeaux 4, 2005. http://www.theses.fr/2005BOR40017.
Texto completo da fonteRenauld, Rémi. "Contribution au pilotage des organismes de formation : application aux établissements de l'enseignement supérieur". Electronic Thesis or Diss., Metz, 2008. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2008/Renauld.Remi.SMZ0819.pdf.
Texto completo da fonteLearning systems are a particular class of systems designed to produce services; their main purpose is to increase the competency of learners. This type of system is likely to face many transformations in the next few years. Indeed, learning systems must be able to respond to the changing needs of learners and of the industries that recruit the learners for employment. Moreover, they will operate in an increasingly competitive and more aggressive environment. The primary objective of this work is to define a performance measurement system of higher education institutions, which we will then link with action levers to allow a reactive control. Note that the main specificity of the learning system is that the product (learner) is also the actor in the production process and the client of the organization that provides the system. Thus we are confronted with a new type of product, the active product ; and the control system must be able to take into account this characteristic of the learning system. We propose a method in order to implement an integrated and reactive system of control. This method is composed of nine different steps from the definition of the system s strategy to the definition of the operational goals. The method is also using a phase of model to define a process map and a UML model.hese works are based on two principal activities: the deployment of the strategy through the conception of the performance measurement system and the conception of the control system itself. These two activities are articulated around a model activity, indispensable to implement our system. Existing methods will be used and adapted to our particular needs, like method of balanced scorecards for the deployment of the strategy or the Statecharts formalism to model the behaviour of our cooperating structure of control
Dos, Santos Fabien. "Contribution à l'étude de la formation des sprays". Phd thesis, Université de Bourgogne, 2012. http://tel.archives-ouvertes.fr/tel-00869635.
Texto completo da fonteDoukkali, Aziz Mohamed. "Etude électronique et physicochimique des premiers stades de la formation des interfaces GaSb-métal : application à l'interface GaSb-Ag". Montpellier 2, 1990. http://www.theses.fr/1990MON20025.
Texto completo da fonteGrgic, Dragan. "Modélisation du comportement à court et à long terme des roches de la formation ferrifère lorraine". Vandoeuvre-les-Nancy, INPL, 2001. http://docnum.univ-lorraine.fr/public/INPL_T_2001_GRGIC_D.pdf.
Texto completo da fonteRenauld, Rémi. "Contribution au pilotage des organismes de formation : application aux établissements de l'enseignement supérieur". Thesis, Metz, 2008. http://www.theses.fr/2008METZ019S/document.
Texto completo da fonteLearning systems are a particular class of systems designed to produce services; their main purpose is to increase the competency of learners. This type of system is likely to face many transformations in the next few years. Indeed, learning systems must be able to respond to the changing needs of learners and of the industries that recruit the learners for employment. Moreover, they will operate in an increasingly competitive and more aggressive environment. The primary objective of this work is to define a performance measurement system of higher education institutions, which we will then link with action levers to allow a reactive control. Note that the main specificity of the learning system is that the product (learner) is also the actor in the production process and the client of the organization that provides the system. Thus we are confronted with a new type of product, the active product ; and the control system must be able to take into account this characteristic of the learning system. We propose a method in order to implement an integrated and reactive system of control. This method is composed of nine different steps from the definition of the system s strategy to the definition of the operational goals. The method is also using a phase of model to define a process map and a UML model.hese works are based on two principal activities: the deployment of the strategy through the conception of the performance measurement system and the conception of the control system itself. These two activities are articulated around a model activity, indispensable to implement our system. Existing methods will be used and adapted to our particular needs, like method of balanced scorecards for the deployment of the strategy or the Statecharts formalism to model the behaviour of our cooperating structure of control
Commandré, Jean-Michel. "Formation des oxydes d'azote lors de la combustion de cokes de pétrole dans des conditions de précalcinateur de cimenterie". Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2002. http://tel.archives-ouvertes.fr/tel-00443942.
Texto completo da fonteKonté, Mamadou. "Investisseurs et Marchés Financiers : du comportement des agents à la formation de prix d'équilibre". Phd thesis, Université Panthéon-Sorbonne - Paris I, 2010. http://tel.archives-ouvertes.fr/tel-00618863.
Texto completo da fonteFarkhutdinov, Anvar. "Les eaux géothermiques du gisement Khankala ˸ formation, utilisation, prévisions". Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEM092/document.
Texto completo da fonteRecently, considerable attention in the world is given to the use of renewable energy sources. Among them geothermal waters are of great importance due to ecological safety and economic efficiency of their use. Russia has confirmed high potential of geothermal water resources, but today only a small proportion is used. One of the most promising areas for geothermal waters is the Chechen Republic, which is at the 3rd place among the Russian regions for approved operational reserves of geothermal waters deposits, the largest of which is the Khankala deposit.Achievement of the sustainability in geothermal waters resource development requires an integrated approach and an important role in solving the problems of exploitation of thermal waters is played by geostatistical analysis and estimation, as well as mathematical modelling. The adjusted structural map of the most productive layer (layer XIII) and a 3-D map of temperature distribution within the Khankala deposit were created using universal kriging. Results approved the importance of the structural-tectonic factor and movement of groundwater in the formation of the temperature regime of the territory. Modelling of the Khankala geothermal waters deposit exploitation allowed to make prognosis of temperature changes, to provide recommendations on injection-production wells location and distance between down holes and to explore possible further exploitation scenarios such as periodic use of different layers by doublet systems.The development of geothermal waters use has undoubted advantages – environmental friendliness and renewability. In order to develop this domain in the Chechen Republic the state support is needed. Issues are the lack of a special legislative framework and special insurance systems. Use of geothermal waters of the 14 explored deposits in Chechen Republic can be a significant contribution to local energy production and economic stability of the region while bringing the environmental benefits of traditional fuels partial replacement.The present work was a contribution to the Khankala geothermal station project, which was successfully launched in the beginning of the 2016. The Khankala geothermal station represents a new stage in use of geothermal waters in the Northern Caucasus as it is the only Russian example of geothermal station with closed loop of production and injection wells (“doublet”) with 100% reinjection of used fluid back into reservoir
Delbracio, Mauricio. "Two problems of digital image formation : recovering the camera point spread function and boosting stochastic renderers by auto-similarity filtering". Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2013. http://tel.archives-ouvertes.fr/tel-00907900.
Texto completo da fonteOberdisse, Julian. "Formation spontanée de vésicules dans un système amphiphile chargé". Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 1997. http://tel.archives-ouvertes.fr/tel-00005981.
Texto completo da fonteNous proposons un modèle thermodynamique quantitatif permettant de décrire la phase de vésicules. Il repose sur une résolution numérique de l'équation de Poisson-Boltzmann dans une cellule de Wigner-Seitz. Les prédictions sont en très bon accord avec les résultats expérimentaux.
Bolgar, Florian. "The impact of quasars during tne epoch of reionization". Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS262.
Texto completo da fonteThe exact role of quasars during the Epoch of Reionization (EoR) is an open question. In this manuscript I study the impact of quasars during the EoR, in four different wavelengths (radio, Lyman-alpha, Lyman continuum and X-rays). I developed a halo finder which can be run on-the-fly in LICORICE, a number of companion tools and many of the routines used in processing the data from the 21SSD database. After briefly studying the escape fraction, I developed a model for quasar UV, radio and X-ray emission, which is able to match observed luminosity functions in a broad range of redshifts, and I make predictions about the 21-cm forest and the radio background of quasars. I then present a new effect on the 21-cm signal observed against the CMB: a radio-loud quasar can leave the imprint of its duty cycle on the 21-cm tomography. I apply this effect in a cosmological simulation and conclude that the effect is probably not observable by the SKA, even for a bright 10 mJy quasar. Then I study the contribution of the Lyman band emission of quasars to the Wouthuisen-Field coupling. A distinctive pattern around the brightest quasars in an SKA field of view may be observable in the tomography, encoding the duration of their duty cycle. Finally, I present ongoing work on including the ionizing UV and X-ray contribution of the quasars in a self-consistent way, taking duty cycles into account
Rifai, Ismail. "Modélisation physique et numérique des écoulements générés par la formation de brèche dans les digues fluviales soumises aux surverses". Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1034.
Texto completo da fonteOvertopping of fluvial dikes (dykes or embankment levees) can promote external erosion, leading to the initiation of breaching and potentially brutal dike failure and inundation of the protected area. This can generate major human, economic, and financial losses. Flood risk management and prevention require precise hazard quantification. Accurate estimate of the flow through the breach is paramount, for which a precise understanding of the breach formation and expansion is required. Existing methods are often the result of investigations conducted on overtopping of frontal dikes (embankment dams). The application of such approaches to fluvial dikes is not reliable and processes underpinning breach expansion are still under research. An innovative experimental program was conducted to fill this gap by investigating the physical processes involved in overtopping induced fluvial dike gradual breaching. Experiments were conducted in the framework of collaboration between the National Laboratory for Hydraulics and Environment (LNHE) of the R&D division of EDF and the research team Hydraulics in Environmental and Civil Engineering (HECE) of University of Liège. Experiments were conducted on two distinct experimental setups, each consisting of a main channel and floodplain area separated by an erodible fluvial dike. The focus was made on overtopping induced spatial erosion of homogenous, non-cohesive dikes. Measurements included continuous scanning of the dike geometry using a non-intrusive method (Laser Profilometry Technique), which was designed and developed specifically for the present works. Tests conducted under controlled flow and dike configurations allowed assessing the effects of channel inflow discharge, downstream channel regulation system, and floodplain confinement on the breach development and outflow. Effects of main channel size, dike material size, apparent cohesion, and bottom erodibility were studied as well. Using the experimental data, the flow features near the breach area was simulated using the two-dimensional depth-averaged hydrodynamic code TELEMAC-2D, which allowed assessing the performance of the code for highly transient and complex flows such as involved in dike breaching. Coupling TELEMAC-2D with the morphodynamic model SISYPHE enabled investigating the interest of a detailed hydro-morphodynamic modeling for fluvial dike breaching studies