Дисертації з теми "Colloïdes – Effets de la température"
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Ould, Eleya Mohamed El Mustapha. "Analyse de la formation des gels acides de laits de vache, de chèvre et de brebis au moyen de la géométrie fractale : étude comparative." Vandoeuvre-les-Nancy, INPL, 1996. http://docnum.univ-lorraine.fr/public/INPL_T_1996_OULD_ELEYA_M_E_M.pdf.
Yin, Fang. "Copolymères multi-stimulables : effet de la composition et de la structure sur leurs propriétés en solution aqueuse." Thesis, Toulouse 3, 2021. http://www.theses.fr/2021TOU30230.
Stimulable polymers have attracted a lot of interest in recent years due to their ability to respond macroscopically, rapidly and reversibly to changes in their local environment, opening the way to multiple promising applications (controlled drug release, modifiable interfaces...). The objective of this thesis is to study the effect of composition, molar mass, architecture, concentration of copolymers on their transformations in aqueous solution triggered by a change of temperature and/or pH (modified by addition of base/acid or by bubbling CO2/N2). In this thesis, we are interested in three families of block or random copolymers carrying functions whose states are modulated by temperature or pH changes: (1) thermosensitive poly((N-vinyl caprolactam)-stat-(N-vinylpyrrolidone)) (P(VCL-stat-VP)) copolymers, (2) thermosensitive poly((n-butylacrylate)-co-(N-isopropylacrylamide)) (P(BA-co-NIPAM)) copolymers with different structures and compositions (diblock, triblock and random) and (3) copolymers sensitive to both stimuli (temperature and pH/CO2): poly((N-isopropylacrylamide)-block-(N-,N-diethylamino ethyl acrylamide)) (PNIPAM-b-PDEAEAM). Their syntheses, carried out by RAFT polymerization, are presented in the manuscript. In addition, we studied the response induced by stimuli on macromolecular parameters of these (co)polymers in water such as the conformation of the chains in solution, the modification of hydrophilicity and/or the ionic charge distributed along the (co)polymer chain. These modifications resulted in the modulations of solubility and influenced the formation of self-assemblies or hydrogels. Thus, after an introduction on the state of the art on stimulable polymers under stimuli of temperature, pH and CO2, the stabilization of colloidal solutions of gold nanoparticles by P(VCL-stat-VP) copolymers with different compositions was the subject of chapter II. The catalytic properties of nanohybrids on the reduction by sodium borohydride of p-nitrophenol to p-aminophenol was studied. The behavior of P(BA-co-NIPAM) with different morphologies (statistical, diblock and triblock) in dilute and concentrated solution under temperature changes was studied and compared in chapter III. This enables to highlight the modification of molecular interactions near critical temperatures. The densities of the formed hydrogels were also compared and a higher density in the case of triblock structures was evidenced. The behavior of PNIPAM-b-PDEAEAM with different compositions in water under change of pH by addition of acid or base and by bubbling CO2/N2 was detailed presented in chapters IV and V respectively. The modifications of the cloud points induced by pH changes as well as the different characteristics of the objects formed were studied. These changes are related to the modifications of the conformations of the (co)polymer chains and the interactions between polymer chains and water at the molecular level
Boire, Adeline. "Structure et dynamiques de dispersions de gliadines de blé : effet de la concentration en protéines et de la température du solvant." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20002/document.
A substantial body of theoretical and experimental studies has been conducted over the last 30 years to establish the link between protein interaction properties, phase transitions and self-assembly. Both colloidal and polymer physics provide a new framework for understanding the driving force for proteins phase behaviour. Such studies have been limited to health-related proteins and to a few food proteins, mainly animal proteins such as casein, whey proteins. This thesis aims to apply this approach to plant proteins to better understand their interactions properties, at the basis of their functional properties within grains and food matrices. This work was carried out on a wheat storage protein isolate mainly composed of the monomeric fraction: gliadins.The objective of this PhD thesis is to investigate the phase transitions of wheat proteins to develop our knowledge on their interaction properties and the associated structures. We organized our experimental approach in five steps. First, we developed an extraction procedure to work on a protein isolate of controlled composition with molecular weight ranging from 20 to 300 kg mol-1. Then, we investigated the phase behaviour of the protein isolate by decreasing the solvent quality, here the temperature. We determined the T-Φ phase diagram, where T is the temperature and Φv the protein volume fraction, that maps the phase and structural transitions of the proteins. This study showed the existence of a liquid-liquid phase separation in the system upon a temperature decrease. We evidenced two different behaviours among proteins as a function of their MWs and highlighted a critical protein size above which the molecular weight is the key determinant of the protein properties. From the phase diagram, two structural studies were conducted. The first one studied the kinetics of phase separation upon temperature decrease to characterize the local dynamics of phase separation and to identify the mechanisms that generate concentrated systems. Two main mechanisms of phase separation have been identified: nucleation-growth and spinodal decomposition. The second one studied the effect of protein concentration on the multi-scale structure of wheat gliadins in good solvent. The integration of all these results allowed us to build the phase diagram of wheat gliadins, integrating thermodynamic and structural data
Jaber, Ahmad. "Interfacial Viscoelastic moduli of bare, surfactant-laden and nanoparticle-laden interfaces oscillating in a weak gel." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0104.
We present a study implementing the oscillating drop method to probe the oil/water interface, modifiable by surfactants or nanoparticles, while surrounded by a continuous phase of controllable rheology. The key question posed in this work concerns the effect of the rheological properties of the continuous phase on the measurements of interfacial viscoelastic moduli extracted from the compression/expansion of an oscillating drop. With this in mind, the continuous phase consists of a thermo-reversible hydrogel K-carrageenan, selected for its interfacial inactivity but also for its hysteresis after the sol/gel transition which allows to have a gel or liquid at the same temperature according to the thermal history.In the case of a pure oil/water interface and under conditions where the KC solution is liquid, the elastic modulus of the interface remains weak. When the KC solution becomes a gel, even if it is weak to the point that the solution flows under its own weight, we witness the appearance of an elastic signature in interfacial viscoelastic measures attesting to the contribution of the rheology of the continuous phase being not negligible.The presence of a surfactant at the oil/water interface, generating an interfacial elastic modulus that increases with the concentration of surfactant in the case of a liquid surrounding medium. In the presence of a weak gel, the interfacial modulus decreases by despite that the modulus of the KC gel increases, this is attributed to a pseudo-localization of deformation at the interface. This phenomenon disappears in the case of an interface laden with solid nanoparticles (Pickering effect).All of this work reveals the importance of deconvoluting interfacial and volume contributions in an interfacial viscoelasticity test of the pendant drop
Reveron, Pojan Helen. "Colloi͏̈des de zircone cériée : synthèse et frittage à basse température." Limoges, 2000. http://www.theses.fr/2000LIMO0027.
Kataya, Zeinab. "Effets de température sur les nanoparticules de CoAg : structure et effets de ségrégation." Phd thesis, Université d'Orléans, 2013. http://tel.archives-ouvertes.fr/tel-01004367.
Mieusset, Roger. "Effets de la température sur les fonctions testiculaires et épididymaires." Paris 11, 1992. http://www.theses.fr/1992PA11T022.
Manel, Stéphanie. "Modélisation de la durée de développement pré-imaginal chez les poïkilothermes sous régime de températures variables." Lyon 1, 1995. http://www.theses.fr/1995LYO10277.
Foret, Lionel. "Effets de charges discrètes aux interfaces d'un électrolyte confiné." Bordeaux 1, 2003. http://www.theses.fr/2003BOR12720.
In an electrolyte film, if the lateral surface charge distance exceeds the screening length, the standard continuous approximation for the charge distribution fails. The discrete nature of the charge has to be taken into account. In interfacial geometries, screening of punctual charge is no longer exponential but algebraic ; the screening cloud charge density and the screened potential decay as r-3. As a consequence : (i) The screening cloud is spread along the interface and can reach a typical lateral length larger than the Debye length. (ii) There is a long-range interaction between the charges. We have shown that despite the r-3 law, this is not a dipolar interaction. If the discreteness of the charge is relavant, the disjoining pressure of the film deviates from that of homogeneously charged surfaces. The pressure is now due to the force created by each discrete charge and is thus, linear in surface charge density. The pressure of the discrete charges is strongly inhomogeneous and may deform "soft" interfaces. The deformations superposition induces an effective interaction of the surface charges. We have shown that the effective interaction of two charges on a liquid interface is repulsive. Thus, this force is not responsible for the charges attraction observed in recent experiments
Bacha, Elsy. "Développement par voie chimique à basse température de couches minces perovskite de titanates de baryum et de strontium." Nantes, 2010. http://archive.bu.univ-nantes.fr/pollux/show.action?id=a54e2d4c-9054-4414-a467-d4e9a15a7672.
The high-k character of ferroelectric materials allows their utilisation in electronic devices. The permittivity depends on intrinsic properties, film compactness, surface roughness, defects like oxygen vacancies in the case of a high temperature crystallization, etc. The present work aims to the development of dense and compact ferroelectric films at low temperatures. Two synthesis routes have been studied. The first is room temperature electrophoretic deposition of BaTiO3 and SrTiO3 nanoparticles, which were elaborated from inorganic precursors in an aqueous solution by a solvothermal route and stabilized in colloidal suspensions. X-Ray diffraction, SEM, TEM, IR and Raman spectroscopy, TGA / MS, density, and BET were employed in order to study composition and morphology of the nanoparticles as a function of the precursor nature and concentration and the thermal treatment. Photon correlation spectroscopy and zeta potential measurements allow determination of the nanoparticles sizes and the conditions for a stable colloidal solution. The second route is a low temperature solvothermal in-situ synthesis, directly from a titanium substrate. Dense and uniform BTO and STO films, slightly textured in the (001) direction, are obtained at temperatures below 200°C. The study of the dielectric properties indicates the existence of the BaTiO3 tetragonal phase. Dielectric losses may be related to space charges located at the grain boundaries which give rise to diffusion currents at low frequencies. The synthesis route developed may open the way for new applications and may also be adapted to other transition metal oxides
Pusset, Raphaël. "Détermination des propriétés de charge d'espèces en solution : analyse et mise au point d'une technique électroacoustique." Paris 6, 2013. http://www.theses.fr/2013PA066575.
The stability of a solution containing charged species depends on the size and on the electric charge of the chemical entities suspended in the solution as well as on the properties of the solvent. In particular, the electric charge is at the origin of the electrostatic forces between the charged entities. This electric charge determines their tendancy to agregate and to sediment or not over time ; this information is essential in areas such as cosmetics or pharmaceuticals. However, determining these charge properties is difficult. They maybe quantified by the stuctural charge of the object, which is rarely measured or by the effective charge often estimated by means electrophoretic mobility or zeta potential. The usual method to determine the electrophoretic mobility is the electrophoresis but this technique cannot be used for opaque suspensions, concentrated suspensions and suspensions with high conductivity. The scarcely used acoustophoretic method allows us to bypass these difficulties. This technique is the only one adapted to concentrated or opaque environments as well as many solutions of indutrial interest, whatever the size of the charged species, from the ion to micrometric particles. The principle of measurement (predicted by Debye, J. Chem. Phys, 1, 13 (1933)) is the analysis of the electric response of the solution under a pressure wave. Our objectve was to design and industrialize an acoutophoresis prototype having the three following charateristics : a much smaller sampling volume than previous devices, direct access to the raw signal, specific tools for the treatment of the signal and a better understanding of the technical possibilities of the techique. Firstly, the report presents the notions necessary to describe the environment of charged objects in a solution and the electrokinetic techniques available to characterize such charged systems. Secondly the analysis of the literature and of actual devices allows us to understand the current state of the technique from both theoretical and experimental points of view. Thirdly we explain the conception and the development of our prototype as a finish product with the desired characteristics. Finally, we present measurements on several model systems, which validate the efficiency of our innovative prototype
Roussy, Laurent. "Étude du comportement des matériaux composites aux températures cryogéniques." Besançon, 1994. http://www.theses.fr/1994BESA2050.
Daviller, Guillaume. "Etude numérique des effets de température dans les jets simples et coaxiaux." Phd thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2010. http://tel.archives-ouvertes.fr/tel-00573368.
Jean-St-Laurent, Mathilde. "Effets des cycles extrêmes de température sur le comportement des matériaux composites." Master's thesis, Université Laval, 2014. http://hdl.handle.net/20.500.11794/26398.
This master dissertation presents the effect of extreme temperature cycles on composite materials of carbon fiber and cyanate-ester resin made of five harness woven fabrics. Three laminates and one sandwich plate were studied. The evaluation of damage present in the laminates showed two different types of damage: vertical microcracks and debonding between the fibers and the matrix. Debonding is only visible on the edges of the laminates. As for the microcracks, they are present both on the edges and inside of the laminates, but in greater quantity on the edges. The damage inside the sandwich plate is present under two forms: vertical microcracks and delamination due to the presence of the adhesive. The effect of thermal cycling on the degradation of the mechanical properties of the laminates was also studied. The mechanical tests performed showed that properties influenced by the matrix behavior were altered by the presence of microcracks.
Catania, Philippe. "Synthèses, caractérisations et mises en forme du supraconducteur haute température YBa2Cu3O7." Montpellier 2, 1990. http://www.theses.fr/1990MON20258.
Ishiguro, Naoko. "L'influence du climat et des affluents sur l'oxygénation et la turbidité des lacs : le cas comparé du Léman, des lacs alpins et japonais." Limoges, 2004. http://www.theses.fr/2004LIMO2002.
Bouhanek, Karima. "Oxydation à haute température de superalliages monocristallins." Toulouse, INPT, 1997. http://www.theses.fr/1997INPT016G.
Mykytczuk, Nadia, Leo Leduc, Jack T. Trevors, and Garry D. Ferroni. "Effets des facteurs environnementaux du drainage minier acide sur les membranes d'Acidithiobacillus ferrooxidans." Acfas-Sudbury, 2007. https://zone.biblio.laurentian.ca/dspace/handle/10219/96.
Ghasemzadeh, Hasan. "Couplages dans les géomatériaux multiphasiques : effets de la température et de la chimie." Phd thesis, Ecole des Ponts ParisTech, 2006. http://pastel.archives-ouvertes.fr/pastel-00002077.
Koo, Min. "Effets de température dans les procédés de gravure plasma : Aspects fondamentaux et applications." Phd thesis, Université Joseph Fourier (Grenoble), 2008. http://tel.archives-ouvertes.fr/tel-00355029.
Hammouda, Tahar. "Mécanismes et cinétique de fusion partielle d'assemblages à Fluor-Phlogopite : modélisation, expérimentation et implications géochimiques." Orléans, 1995. http://www.theses.fr/1995ORLE2015.
Reyt, Françoise. "Influence de la température sur la liaison calcium-protéine." Bordeaux 2, 1997. http://www.theses.fr/1997BOR2P017.
Baril, Eugénie. "Quantification de l'influence de l'environnement sur la formation et la thermo-résistance des spores bactériennes." Brest, 2011. http://www.theses.fr/2011BRES2047.
The aim of this PhD study was to quantify the influence of the sporulation environment (temperature, pH and aw) on the spore formation of Bacillus weihenstephanensis and B. Licheniformis and on their heat resistance. A two-step sporulation methodology was developed to study sporulation in environmental conditions close to growth boundaries. Sporulation boundaries (temperature, pH and aw) were observed inner growth boundaries. A primary model was proposed to quantify the influence of the environment on spore formation. A decrease in sporulation temperature and pH delayed the time to first spore per ml. The maximal spore heat resistance was observed for spores produced at temperature and pH close to the optimal growth values. A secondary model was then proposed and validated to estimate the spore heat resistance as function of the sporulation and heat treatment environments. Finally, this study allows defining control points in foodstuff to prevent spores in food products. A relationship between the influence of environmental temperature and pH on growth and sporulation was pointed out
Desserrey, Franck. "Comportement mécano-chimique du nickel vis à vis de l'oxygène à haute température : aspects expérimentaux et prévisionnels." Dijon, 2002. http://www.theses.fr/2002DIJOS057.
Dasriaux, Marion. "Evolutions microstructurales du PEEK au-dessus de sa température de transition vitreuse lors de maintiens sous pression et température." Phd thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2012. https://theses.hal.science/docs/00/78/60/16/PDF/Manuscrit_Dasriaux_Marion.pdf.
At least one fraction of the amorphous phase of semi-crystalline polymers, confined by the crystalline lamellae, is in out-of-equilibrium state, so that "physical aging" or "secondary crystallization" features can be observed (e. G. , by calorimetry) even above the glass transition temperature. This issue has already been addressed in the literature in several semi-crystalline polymers at atmospheric pressure. But despite the well-known influence of pressure on molecular mobility, the pressure-sensitivity of these microstructure rearrangements has never been tackled. This study focuses on amorphous evolution occurring in highly pressurized Poly-Ether-Ether-Ketone (PEEK), in comparison with atmospheric pressure. The phenomenon is tracked by Differential Scanning Calorimetry (DSC). A significant influence of pressure is evidenced, pressure confining rearrangements within spatially limited domains. The stability and co-existence of reorganization processes upon successive annealings is also investigated. Finally, relationships between constrained and free amorphous phase rearrangements are discussed. The free fraction of the amorphous phase results relaxed after annealing at atmospheric pressure and stabilized into a denser state after high pressure annealing. All these results allow to discuss the phenomena involved in the microstructural evolution of PEEK: a "physical aging" or "secondary crystallization"
Le, Morvan Caroline. "Effets des températures extrêmes sur l'expression des défenses immunes chez la carpe (Cyprinus carpio) : corrélation avec la dynamique membranaire des leucocytes périphériques." Lyon 1, 1995. http://www.theses.fr/1995LYO10055.
Addala, Farida. "Etude du comportement rhéologique des bitumes à moyenne et basse température." Lyon, INSA, 1989. http://www.theses.fr/1989ISAL0066.
This study, performed in the framework of a collaboration with the Compagnie française de Raffinage Total France, is part of a general study on the rheological behaviour of bitumen. More specifically, our contribution consists of the development of an experimental apparatus allowing mechanical behaviour study of the bituminous material at low and medium temperature. In a first part we present the state of the art in this domain from experimental as well as theoretical point of view. In the the second part we describe the developed apparatus for torsion-compression tests on hollow cylindrical sample and we analyse the experimental results we have obtain. Finally the third part deals with numerical computations by the finite element method of the tests described in the previous part as well as the penetration tests. Different non-linear viscoelastic models have been used for this purpose after calibration of their parameters according to the experimental results
Dardié, Jason. "Étude des effets des rayonnements sur les matériaux et systèmes électroniques." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTS001.
TMI-Orion, a company specialising in systems for acquiring physical parameters (pressure, temperature, humidity, etc.) for harsh environments, wishes to diversify, particularly in the civilian nuclear markets or the new space. These two markets are subject to strong radiative stress. The company, which is at the origin of the thesis, wishes to develop its skills with regard to radiative stress in order to be able to propose applications in these sectors. This thesis was therefore conducted with the main objective of providing as much information as possible on radiative stress to TMI-Orion. We have therefore identified four areas of work to address this issue.In the context of this thesis, we began by describing the radiative environments encountered in the space and civilian nuclear fields. Then the mechanisms of radiation-matter interaction were defined. Finally, the effects of radiation on electronics have been given.The second area of work consists of a study of the degradation mechanisms of elementary electronic components (MOS and bipolar transistors) as a function of the temperature to which they are subjected during irradiation. The effect of low (up to 100 K) and high (up to 400 K) irradiation temperatures on the degradation of elementary components was studied. During this study we were also able to compare the degradation obtained between a cobalt-60 irradiation and an X-ray irradiation.The third area of work consists of a simulation study on shielding against radiative stress. As part of this work, we have developed two calculation codes on GEANT4. The first one allows to study the dose deposited by a cobalt-60 source for different shielding conditions. The second one allows to model the X-ray generator of the IES laboratory and gives its energy spectrum. The effect of different filters on the spectrum is also studied.The last axis of this thesis work consists of a complete reliability study on autonomous data loggers developed by TMI-Orion. One particular recorder, the PicoVACQ, is used as an example. The reliability of this recorder was calculated by an analytical method, studied using the feedback available within the company, measured against thermal stress and measured against radiative stress. Finally, the search for a microcontroller, a central component of a radiation-tolerant data acquisition system, was carried out. One microcontroller in particular appears to have good resistance to dose effect and will probably be used by the company in its future projects
Racinais, Sébastien. "Performance de courte durée en milieu tropical:Influence de la Température environnementale et du moment de la journée." Antilles-Guyane, 2004. http://www.theses.fr/2004AGUY0118.
Muscular power display a significant diurnal increase in a neutral environment only and a 60-minute moderately warm exposure increases muscular power in the morning only when body temperatures are their lowest (Sudy 1). The fact that the passive warm-up effect body temperature can not be combined may be explained by their similar action on muscular contractile properties (study 2). These results point to the existence of a "ceiling" above which an increase in body temperature fails to improve muscular performance. Indeed,our results show that an extremely hot exposure fails to modify short term performance in a moderately warm and humid environment (study 3). Similary to tropical climate,a 30-minute leg immersion in a hot bath in neutral environment may blunt the diurnal variation in muscular power (study 4),whereas active warm-up increases muscular power both in the morning and in the evening(sTUDY 5)
Talby, Riad. "Mesure des fluctuations de température avec des thermocouples fins, par référence à un fil "froid"." Aix-Marseille 2, 1987. http://www.theses.fr/1987AIX22011.
Menou, Abdellah. "Etude du comportement thermomécanique des bétons à haute température. : Approche multi échelles de l'endommagement thermique." Pau, 2004. https://tel.archives-ouvertes.fr/tel-00008986.
This research work deals within the framework of the study of durability when subjected ti hight temperature in case of fire. The aim of this study is to identify the elementary mechanisms leading the degradation of concretes at hight temperature. Adopted step consists to uncoupling the thermal damage, of mechanical origin (accompanied with deformations) and which takes place in the macrocospic and tiny scale, of the thermal damage of physical and chemical origin (not accompanied with deformations) and which is due mainly to the physical and chemical alterations in material. This approach is based on the exploitation of two different models ; the "Digital Concrete" microscopic model and the macroscopic damage deviatoric model MODEV, both implemented in the F. E. Software SYMPHONIE. Concurrently, an experimental study was achieved in order to feed and to validatez the "Digital Concrete" model. The evolution of mechanical characteristics of concrete was studied using multi-scale approach and three point bending tests were performed on five cementeous materials. Multi-scales approach of the model "Digital Concrete" allowed to find by simulation the experimental warmly behaviour. This approach allowed to put in evidence the existence of the micromechanical deformation and to propose an original approach allowing identification by simulation the laws concretes behaviour at hight temperatures. This approach was also applied successfully to explain the thermoapplication refractory concrete subjected to very hight temperatures was also realized
Raharison, Lucie Hortense. "Exercice maximal, métabolisme musculaire et évolution des températures cutanée et centrale chez les sujets ayant présenté un "syndrome d'hyperthermie d'effort" (HTE)." Aix-Marseille 2, 2001. http://www.theses.fr/2001AIX22093.
Launay, Jean-Claude. "Les adaptations croisées climatiques chez l’humain : caractérisation, mécanismes et risques thermophysiologiques." Lyon 1, 2008. http://www.theses.fr/2008LYO10062.
Intercontinental travels, but also overseas deployment of troops may submit adapted persons to a given thermal strain to an opposite thermal strain, exposing them to unassessed thermophysiological risks. This problem encompassed the poorly researched concept of thermal cross-adaptation. Using sweating tests (Tdb=45 °C, RH=10 %, 90 min) and standard cold air tests (Tdb=1 °C, 120 min) in humans, before and after heat acclimatization (28 d in French Guyana) or cold acclimatization (55 d in Artic), we characterized heat/cold and cold/heat cross-adaptations. The thermophysiological mechanisms involved in their development were described in 24 subjects submitted to different thermal loads. The resulting thermophysiological risks were evaluated. A methodology for studying, characterizing and assessing the medical risks for other cross-adaptations is proposed in order to optimize the medical prevention
Dasriaux, Marion. "Evolutions microstructurales du PEEK au-dessus de sa température de transition vitreuse lors de maintiens sous pression et température." Phd thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2012. http://tel.archives-ouvertes.fr/tel-00786016.
Mnif, Hassène. "Contribution à la modélisation des transistors bipolaires à hétérojonction Si/SiGe en température." Bordeaux 1, 2004. http://www.theses.fr/2004BOR12786.
The consideration of the temperature and in particular of he self-heating effect in Si/SiGe heterojunction bipolar transistors is a fundamental aspect to predict in a precise way these electric characteristics. The use of these components in microwaves applications exposes to various tempertaures and strong densities of current, accentuates enormously these effects. Consequently, a precie modelling of these phenomena is necessary. A dynamic model describing the self-heatinng, characterized by a rise in the junction temperature, is developed. An electric equivalence close to the analytical model, compatible with SPICE electric models type, is established. A specific test bench is used in order to evaluate the new model and to extracts its parameters. In a second part, the temperature dependence of the various compact model parameters is studied, in particular in the HICUM model
Douzals, Jean-Paul. "Effets des hautes pressions isostatiques sur les modifications physico-chimiques de l'amidon." Dijon, 1999. http://www.theses.fr/1999DIJO5004.
Daniel, Isabelle. "Aluminosilicates à haute pression et haute température : amorphes, verres, liquides et cristaux : étude par spectroscopie Raman." Lyon 1, 1995. http://www.theses.fr/1995LYO10279.
Courtial, Yannick. "Etude du comportement mécanique à haute température de cermets WC-Co : Effets de la microstructure." Lyon, INSA, 1991. http://www.theses.fr/1991ISAL0071.
Characterization of mechanical properties of WC-(17,5-25 %) Co cemented carbide at high temperatures (600-1000°C) and particularly of their resistance to crack propagation cannot be done by using the laws of behaviour of fragile materials (elastic range) and on the basis of the only criterion of KIc overload breakage. At this level of temperature, the behaviour of these materials is indeed of elastoplastic type. We have therefore used the notion of R CURVE : curve of resistance to crack propagation. We have thus access to the values of stable growth start of crack, of propagation and to the differentiation of elastic and plastic phenomena. Comparison of the different methods (RICE,GARWOOD and SAKAI) which allow to obtain R curves led us to the following conclusions: the RICE method is the most suitable for WC-Co cermets; KIc RICE corresponds to the start of stable growth of cracks;definition of a criterion as a criterion of overload breakage at hight temperature. We have developed at the same time a DOUBLE TORSION device and have applied this measure to the case of cermets. It has been possible to observe a slow growth of under-critical defects at 600°C. The objective of all these measurements is to observe the influence of MICROSTRUCTURE and COBALT CONTENT on the high temperature mechanical properties of cermets developed by the CERAMETAL (Lux) company
Grenier, Benjamin. "Spectroscopie théorique : description des effets de la température sur les paramètres de résonance magnétique nucléaire." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0494/document.
- Our objective is to define a theoretical methodology, which allows to simulate the Nuclear Magnetic Resonance (NMR) spectra taking into account the temperature effects, in order to propose a help to the interpretation of the more relevant experimental results.- To deal with the description of the temperature effects on the NMR parameters, we have studied azacalixarenes, which are cyclic oligomers of phenol units linked together by nitrogen bridges. These molecules have a calyx shape, hence their name azacalixarenes. By this cavity these molecules can capture different types of compounds and are used in the host-guest chemistry field.- A wide variety of substituents can be attached to these azacalixarenes. Experimentally, one can easily follow the structure variations effects, at the level of physicochemical properties by NMR.- For this reason, we first investigated the geometric description of azacalixarenes as a function of different substituents and different isomers using the Density Functional Theory, so without taking into account the temperature. - Then, we simulated the NMR parameters of these systems using the Density Functional Theory. This is to calculate the azacalixarenes NMR spectrum in the ground state.- FInally, by performing molecular dynamics simulations using Molecular Mechanics, we were able to take into account the temperature effects. We were able to simulate the NMR parameters of these systems taking now into account the effects of temperature
Castellano, Aloïs. "Étude des effets de la température sur les combustibles nucléaires par une approche ab initio." Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS062.
To ensure the security of nuclear electricity production, an understanding of the behavior of nuclear fuel materials is necessary. This work aims at making a contribution to the study of the effects of temperature on nuclear fuels, by using an ab initio approach through density functional theory and ab initio molecular dynamics (AIMD). To explicity take account of the temperature, a non-perturbative lattice dynamics method is formalised, allowing to study the evolution of phonons and thermodynamic properties with temperature. In order to reduce the important computational cost of AIMD, a machine-learning based sampling method is developped, which allows to accelerate the simulation of materials at finite temperature. Those different methods are applied to describe the stabilisation of uranium-molybdenum alloy at high temperature, as well as the lattice dynamics of uranium and plutonium dioxides
Grenier, Benjamin. "Spectroscopie théorique : description des effets de la température sur les paramètres de résonance magnétique nucléaire." Electronic Thesis or Diss., Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0494.
- Our objective is to define a theoretical methodology, which allows to simulate the Nuclear Magnetic Resonance (NMR) spectra taking into account the temperature effects, in order to propose a help to the interpretation of the more relevant experimental results.- To deal with the description of the temperature effects on the NMR parameters, we have studied azacalixarenes, which are cyclic oligomers of phenol units linked together by nitrogen bridges. These molecules have a calyx shape, hence their name azacalixarenes. By this cavity these molecules can capture different types of compounds and are used in the host-guest chemistry field.- A wide variety of substituents can be attached to these azacalixarenes. Experimentally, one can easily follow the structure variations effects, at the level of physicochemical properties by NMR.- For this reason, we first investigated the geometric description of azacalixarenes as a function of different substituents and different isomers using the Density Functional Theory, so without taking into account the temperature. - Then, we simulated the NMR parameters of these systems using the Density Functional Theory. This is to calculate the azacalixarenes NMR spectrum in the ground state.- FInally, by performing molecular dynamics simulations using Molecular Mechanics, we were able to take into account the temperature effects. We were able to simulate the NMR parameters of these systems taking now into account the effects of temperature
Balu-Després, Caroline. "Séparation de phase d'un polymère hydrosoluble et thermosensible : le poly[N-isopropylacrylamide]." Versailles-St Quentin en Yvelines, 2005. http://www.theses.fr/2005VERS0041.
Les solutions de PNiPAm dans l'eau présentent le comportement singulier de températures de transition de phase Tpt décroissantes avec la concentration jusqu'à 40% de polymère. Lorsque T>Tpt, le système se sépare, formant des colloïdes riches en polymère, stables en solution dans une large gamme de concentrations et dont la taille dépend de la température et de la concentration. La stabilité des colloïdes provient de la présence de charges sur les particules de polymère neutre. L'ajout de sel dans le système entraîne, à partir d'un certain seuil de salinité, la déstabilisation des colloïdes et une séparation de phase macroscopique
Rosen, Michel. "Contribution à l'étude des effets du vent et d'un gradient de température sur l'efficacité des écrans acoustiques." Le Mans, 1986. http://www.theses.fr/1986LEMA1007.
El, Babili Mohammed. "Métabolisme branchial de la sphingomyéline et transport du sodium chez deux espèces euryhalines : Dicentrarchus labrax et Carcinus maenas : influence de la température et de la salinté." Lyon 1, 1997. http://www.theses.fr/1997LYO10339.
Pierrot, André. "Contribution a l'étude des transferts de chaleur à haute température dans les milieux alvéolaires." Perpignan, 1987. http://www.theses.fr/1987PERP0032.
Alarcon, Charles. "Cycle biogéochimique du silicium en environnement tropical : application à l'étude des sols à Mascareignite de l'île de la Réunion." Aix-Marseille 3, 1997. http://www.theses.fr/1997AIX30030.
Trégon, Bernard. "Evaluation et caractérisation d'une technologie d'assemblage MCM-L pour environnement haute pression forte température (120 MPa, 175°C)." Bordeaux 1, 2002. http://www.theses.fr/2002BOR12580.
The first part of this study is an analysis of electronics needs for severe environmental conditions, that is pressure/temperature combined stress, and so the different potentials applications domains, The second part establish a liste of degradation modes of assembly materials implied in prototypes manufacture. These protoypes are intend to word under 120Mpa of pressure and 175°C of température. Analytic modelisation of each degradation modes are listed; Then we designed and realised an environmental test bench to study our prototypes. The third part is a theoretical behavioural study of components parts under pressure/temperature combined stress. This study has been completed through an experimental analysis. Finally, the fourth part is an experimental analysis of complete prototypes manufactured for our study. This analysis deals about sturdiness of the electronic funcion, so as about the different assembly options degradations of each protoypes. This analysis has been completed with a simulation study using finite elements method
Neuville, Daniel R. "Propriétés thermodynamiques et rhéologiques des silicates fondus." Paris 7, 1992. http://www.theses.fr/1992PA077141.
Grignon, Christophe. "Un modèle de thermique 2D appliqué aux structures hétérogènes creuses avec source intérieure mobile en régime fortement varié : le cas du tube d'arme en rafale." Poitiers, 1995. http://www.theses.fr/1995POIT2303.
Djezzar, Karina. "Sur l'étirabilité et la biétirabilité de copolymères d'éthylène et d'alcool vinylique." Lille 1, 1995. http://www.theses.fr/1995LIL10087.