Дисертації з теми "Hydrogénation – Effets de la chaleur"
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Massard, Romaric. "Étude des effets de contraintes sur catalyseurs bimétalliques PDNI supportés." Lyon 1, 2006. http://www.theses.fr/2006LYO10156.
Повний текст джерелаTo study strain effects on catalytic properties for supported particles, core-shell Ni-Pd bimetallic nanoparticles have been prepared by chemical synthesis, characterized by multiple techniques (EDS, TEM, EXAFS, etc. ) and studied in buta-1,3-diene hydrogenation. The core-shell structure of Ni-Pd particles and the compressive stress induced on Pd surface atoms, due to its larger atomic radius compared to Ni, have been evidenced by EXAFS. On PdNi model catalysts, Pd activity is amplified. In our case, no amplification of the Pd activity is observed for a monolayer of strained Pd on Ni particles. As a consequence, compressive strain on Pd surface atoms of nanoparticles seems not to play a major role in the amplification of the activity for the buta-1,3-diene hydrogenation; surface reconstruction appearing on extended surfaces to relax the surface stress seems to be the key point
Vásquez, Salcedo Wenel Naudy. "Biο jet fuels prοductiοn frοm lignοcellulοsic biοmass : butyl levulinate a prοmising mοlecule tοwards the develοpment οf sustainable aviatiοn fuels". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMIR12.
Повний текст джерелаIn the context of the aviation sector, which poses significant challenges due to the complexity and stringent standards of fuel, our research proposal gains particular relevance. We aim to develop an integrated approach that fully valorizes lignocellulosic biomass into jet fuels, thereby contributing to the sustainable development of society. Lignocellulosic biomass is a renewable resource that can be used as feedstock to produce high-value materials and chemicals, such as jet fuel. This type of biomass valorization includes many transformation steps, for which the kinetics and the thermal risk of the chemical reaction are not necessarily known. This work focuses on a specific compound: butyl levulinate (BL). This compound can be obtained from lignocellulosic biomass and can be transformed into gamma-valerolactone (GVL) via hydrogenation. The GVL is a vital platform molecule that can serve as a feedstock to produce substitutes for fossil fuels like gasoline, diesel, and jet fuels. The main objectives of this research are: 1) To develop a robust and reliable kinetic model for BL hydrogenation to produce GVL. Here, we seek to develop a kinetic model experimentally in different thermal modes of operation, i.e., isothermal, isoperibolic, and adiabatic. This model type not only predicts kinetics and the corresponding heat-flow rate but also allows the assessment of the thermal risk related to the chemical reaction. The experiments for developing this kinetic model were performed in the calorimeter reactor Mettler-Toledo RC1. 2) The complete valorization of lignocellulosic biomass targets the industrial scale. Therefore, the continuous production of GVL from BL should be assessed. In that sense, we studied the thermal stability of the continuous production of GVL from BL in a CSTR reactor (continuous stirred tank reactor). 3) One of the intriguing aspects of our research is the potential use of butyl levulinate (BL) as a fuels additive. We have conducted a thorough assessment of the suitability of BL as a kerosene additive, aiming to understand how its addition affects the combustion efficiency and operating limits in a gas turbine combustion chamber. The results obtained concerning the kinetic model showed that the Non-Competitive Langmuir-Hinshelwood models predict the experimental data of concentration and temperature for BL hydrogenation with good accuracy. The thermal risk analysis, linked to BL hydrogenation, showed that the energy released during the reaction is relatively low, ΔH_{hyd} = -35.28 kJ/mol +/- 1.00 kJ/mol, and subsequently the thermal stability study showed that for values of Ua > 1500 W/m³/K in a continuous reactor, the risk of thermal instabilities is low. The evaluation of BL as a kerosene additive showed that adding up to 20% of BL into Kerosene does not significantly change the physical properties, neither the combustion efficiency nor the operating limits in the operating conditions considered during the combustion assessment
En el contexto del sector de la aviación, que plantea importantes retos debido a la complejidad y a los estrictos estándares de combustible, nuestra propuesta de investigación cobra especial relevancia. Nuestro objetivo es desarrollar un enfoque integrado que valorice plenamente labiomasa lignocelulósica en combustibles para aviones, contribuyendo así al desarrollo sostenible de la sociedad. La biomasa lignocelulósica es un recurso renovable que se puede utilizar como materia prima para producir materiales y productos químicos de alto valor, como el combustible para aviones. Este tipo de valorización de la biomasa incluye muchas etapas de transformación, para las cuales no necesariamente se conoce la cinética y el riesgo térmico de la reacción química. Este trabajo se centra en un compuesto específico: el levulinato de butilo (BL). Este compuesto se puede obtener a partir de biomasa lignocelulósica y se puede transformar en gamma-valerolactona (GVL) mediante hidrogenación. El GVL es una molécula plataforma vital que puede servir como materia prima para producir sustitutos de combustibles fósiles como la gasolina, el diésel y los combustibles para aviones. Los principales objetivos de esta investigación son: 1. Desarrollar un modelo cinético robusto y fiable para la hidrogenación de BL para producir GVL. Aquí, buscamos desarrollar un modelo cinético experimentalmente en diferentesmodos de operación térmica, es decir, isotérmico, isoperibólico y adiabático. Este tipo de modelo no solo predice la cinética y el flujo de calor correspondiente, sino que también permite evaluar el riesgo térmico relacionado con la reacción química. Los experimentos para el desarrollo de este modelo cinético se realizaron en el reactor calorímetro Mettler-Toledo RC1. 2. La valorización completa de la biomasa lignocelulósica se dirige a la escala industrial. Por lo tanto, debe evaluarse la producción continua de GVL a partir de BL. En ese sentido, estudiamos la estabilidad térmica de la producción continua de GVL a partir de BL en un reactor CSTR (reactor continuo de tanque agitado). 3. Uno de los aspectos intrigantes de nuestra investigación es el potencial uso del levulinato de butilo (BL) como aditivo de combustibles. Hemos llevado a cabo una evaluación exhaustiva de la idoneidad del BL como aditivo de queroseno, con el objetivo de comprender cómo su adición afecta la eficiencia de la combustión y los límites de funcionamiento en una cámara de combustión de turbina de gas. Los resultados obtenidos en relación con el modelo cinético mostraron que los modelos no competitivos de Langmuir-Hinshelwood predicen los datos experimentales de concentración y temperatura para la hidrogenación de BL con buena precisión. El análisis de riesgo térmico, vinculado a la hidrogenación BL, mostró que la energía liberada durante la reacción es relativamente baja, ΔH_{hyd} = -35.28 kJ/mol +/- 1.00 kJ/mol, y posteriormente el estudio de estabilidad térmica mostró que para valores de Ua > 1500 W/m ³/K en un reactor continuo, el riesgo de inestabilidades térmicas es bajo. La evaluación del BL como aditivo de queroseno mostró que la adición de hasta un 20% de BL al queroseno no cambia significativamente las propiedades físicas, ni la eficiencia de la combustión ni los límites de funcionamiento en las condiciones de funcionamiento consideradas durante la evaluación de la combustión
Rifai, Charaf Eddine. "Effets électroniques et stériques des ligands dans la chimie du zirconocène : influence sur l'activité catalytique." Toulouse 3, 1989. http://www.theses.fr/1989TOU30211.
Повний текст джерелаDouhou, Sallam. "Réaction thermique vers 800 k de l'isobutene seul ou en présence d'hydrogène : étude cinétique et modélisation informatique en phase homogène : effets de parois métalliques." Nancy 1, 1992. http://www.theses.fr/1992NAN10180.
Повний текст джерелаAbdoul-Wahab, Mohamed Houssein. "Hydrogénation énantiosélective du pyruvate d'éthyle sur platine : effets de la préparation et de la modification des catalyseurs." Poitiers, 1995. http://www.theses.fr/1995POIT2287.
Повний текст джерелаAlame, Mohamad. "Tentative de corrélation structure-énantiosélectivité et effet de pression en hydrogénation asymétrique." Lyon 1, 2007. http://www.theses.fr/2007LYO10016.
Повний текст джерелаThe enantioselectivity of catalytic asymmetric hydrogenations can be largely influenced by the hydrogen concentration in the catalytic liquid phase, with generally, a negative impact on enantiomeric excess (ee). In this thesis, we showed, on a large number of chiral diphosphine (56) and three prochiral substrates of acylaminoacrylate ester, that the conclusion of a negative effect of the hydrogen pressure generally admitted in the bibliography is wrong. Indeed, on the basis of 168 studied catalytic systems (diphosphine/substrate), an equivalent distribution of negative effects (28%) and beneficial effects (29%) is observed. In addition, the electronic effects were also studied on a restricted family of diphosphines of the BINAP type by substitution on the binaphtyl group in 5,5' and 4,4' position or para of the phenyls groups carried by phosphorus. The majority of these derivatives of the BINAP had to be synthesized. In particular a new method for the synthesis of derived 5,5' (Me, COOH, Ph) was developed and a new strategy of synthesis in ionic liquid medium was designed for the preparation of the 4,4'derivatives. In the case of para derivatives position, a clear correlation between enantiomeric excess and the HAMMETT constant for all the substituents (Me, H, NH2, +NMe3, OMe, OH, O-) is obtained. The enantioselectivity can thus be tuned, from +57 to -34 %
Girodeau, Alexandre. "Effets biologiques et psychomoteurs de la deshydratation induite par la chaleur." Bordeaux 2, 1993. http://www.theses.fr/1993BOR2M144.
Повний текст джерелаEl, Eter Mohamad. "Synthèse, caractérisation et évaluation de nouveaux précurseurs azotés pour dépôt de films d'oxydes métalliques MO2 (M = Hf, Zr) par MOCVD à injection liquide." Lyon 1, 2008. http://tel.archives-ouvertes.fr/docs/00/37/62/76/PDF/Eleter.pdf.
Повний текст джерелаNew precursors for LI-MOCVD (Liquid Injection Metal Organic Chemical Vapor Deposition) of Hf and Zr were synthesized and characterized by FT-IR, NMR multi-nuclei, X-ray diffraction on monocrystal and TGA. The comparison of the thermal behaviours of various synthesized complexes made it possible to study the effect of various groups on their volatility and thermal stability. The mono-amidinates and -guanidinates appeared more volatile and less stable thermically than the di-amidinates and -guanidinates. The films of hafnium oxide deposited were characterized by XRD, XRR, ATR and XPS. The asymmetrical mono-guanidinates such as Hf(NEt2)3(iPr-Et2-tBu-GUA) and the asymmetrical diguanidinates such as Hf(NMe2)2(Et-Me2-tBu-GUA)2 are very promising for the deposit of HfO2 films. They allow the stabilization of a crystalline phase of HfO2 with a symmetry that is superior to the monoclinical phase at 580°C. Moreover, these precursors allow obtain nitrided films of HfO2 in absence of an additional stage of nitriding
Belmeliani, Abdelhamid. "Réaction thermique du propane, seul ou en présence d'hydrogène : étude cinétique, modélisation et effets de parois métalliques vers 800 k." Nancy 1, 1993. http://www.theses.fr/1993NAN10034.
Повний текст джерелаPrévost, Michel. "Pompes à chaleur mettant en jeu une réaction chimique : identification des réactions, étude du système acétone-hydrogène-isopropanol." Toulouse, INPT, 1988. http://www.theses.fr/1988INPT029G.
Повний текст джерелаSommet, Agnès. "Médicaments et vague de chaleur : approche pharmacoépidémiologique." Toulouse 3, 2009. http://thesesups.ups-tlse.fr/592/.
Повний текст джерелаAn exceptional heat wave occurred during august 2003 in France, leading to more than 14,800 deaths estimated. We characterized all 'serious' adverse drug reactions (ADR) occurred in patients older than 70 years between 1st July and 31st August 2003, recorded in the French PharmacoVigilance Database, and related to excessive heat (n=68). The most frequently ADRs were metabolic. Drugs more frequently involved were diuretics, angiotensin converting enzyme inhibitors, and antidepressants. During another summer with a heat wave in 2006, diuretics were more frequently involved, whereas the number of ADRs was similar. In 2007, we performed a multicentric case-control study in 3 university hospitals in France, to compare drugs taken by patients hospitalized for a 'serious' hyperthermia and/or dehydratation with controls. Cases took more drugs than controls (4. 3 vs 3. 9; p<0. 001), particularly neuroleptic drugs (3. 6% vs 0. 5%; p=0. 007), and presented more severe renal impairment. This pilot work could allow improving methodology of further studies on drugs during heat waves
Vibhatavata, Phuangphet. "Fabrication de carburant synthétique par valorisation du CO2 et de la chaleur nucléaire." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10208/document.
Повний текст джерелаThis work is in the context of large-scale efforts to enhance greenhouse gas emissionsmitigation. A potential way to recycle CO2 as a carbon feedstock to produce a synthetic fuelby the conversion of CO2 and hydrogen, produced from water electrolysis using nuclear orrenewable energy. This process may be sustainable in some specific context like in Frenchcontext; French electricity is mainly generated by nuclear and renewable energies that havelow carbon footprints. In this work, a synthetic fuel is produced by CO2 hydrogenation intosynthesis gas via the Reverse Water-Gas Shift (RWGS) reaction, then synthesis gas isconverted into a synthetic fuel. This research project consists of two main parts:The first part focuses on the development of a selective and stable catalyst for the RWGSreaction at moderate temperature (723-773 K). We have applied the micro-kinetic approach ofthe RWGS reaction and its side reactions in order to determine a multi-metallic catalyst,which has shown to perform better selectivity and stability than a conventional, commercialcatalyst under the optimal operating conditions of the RWGS reaction. In the second part, weconducted the simulations of a large-scale dimethyl ether (DME) production process by theconversion of CO2 from industrial flue gases in the French context. The simulation of the CO2to DME process showed the process energy efficiency of 52% and the emissions reductionpotential of 88% of total CO2 emissions
Grech-Angelini, Sébastien Jacquiet Philippe. "Effets de la déshydratation sur le métabolisme énergétique et sur l'état corporel du dromadaire, camelus dromedarius." [S.l.] : [s.n.], 2007. http://oatao.univ-toulouse.fr/1790/1/debouch_1790.pdf.
Повний текст джерелаEnel, Laurent. "Conception et exploitation de radiomètres microondes multisondes : contribution à l'étude de faisabilité d'un scanner par T.M.O." Lille 1, 1985. http://www.theses.fr/1985LIL10082.
Повний текст джерелаDespretz, David. "Modélisation et caractérisation électromagnétiques et thermiques de nouveaux applicateurs en structure filaire pour hypothermie micro-onde contrôlée par radiométrie micro-onde : application en cancérologie et urologie." Lille 1, 1997. http://www.theses.fr/1997LIL10119.
Повний текст джерелаSozanski, Jean-Pierre. "Contribution à l'étude et à la réalisation d'un nouveau dispositif radiométrique micro-onde à deux références internes de température : application à l'hyperthermie-thermothérapie micro-onde." Lille 1, 1995. http://www.theses.fr/1995LIL10171.
Повний текст джерелаLumingu, Huguette Mena Mbote. "L'astreinte thermique de la fenaison chez des jeunes travailleurs agricoles." Master's thesis, Université Laval, 2009. http://hdl.handle.net/20.500.11794/21114.
Повний текст джерелаBdéoui, Fahed. "Effets du rayonnement des gaz sur certaines instabilités thermoconvectives." Châtenay-Malabry, Ecole centrale de Paris, 1998. http://www.theses.fr/1998ECAP0554.
Повний текст джерелаDebab, Abdelkader. "Effets de l'agitation sur les transferts thermiques par double enveloppe dans une cuve agitée." Toulouse, INPT, 2002. http://www.theses.fr/2002INPT003G.
Повний текст джерелаAbdelaziz, Fadila. "Contribution à l'étude de la convection dans les faisceaux tubulaires : effets de l'orientation des tubes et de la génération de bulles en paroi." Vandoeuvre-les-Nancy, INPL, 1989. http://www.theses.fr/1989NAN10459.
Повний текст джерелаBilla, Renan. "Sur le comportement de deux aciers inoxydables austénitiques (17-12 SPH ET AMCR 0033) aux températures intermédiaires : Mise en évidence des interactions dislocations-configurations de defauts ponctuels : Propositions pour une formulation anisotherme." Besançon, 1989. http://www.theses.fr/1989BESA2025.
Повний текст джерелаLohr, Christophe. "Modélisation et optimisation d'un applicateur cylindrique à ondes progressives fortement dissipatif : rétroaction thermique et analyse en mode propre : cas de l'eau et de l'éthanol." Dijon, 2004. http://www.theses.fr/2004DIJOS030.
Повний текст джерелаThe aim is the identification of the modes TE, TM, HEM which appear within a cylindrical waveguide loaded axially with ethanol or water rod. The strong thermal dependency of the dielectric properties results in thermal trajectories in complex plane a-b which looks like loops. Coupling of modes is induced by distortion of thermal trajectories due to heating. The coupling between thermal and electromagnetic processes illustrates effects of thermal change of dielectric losses upon heating dynamic. In spite of dielectric losses of water which decrease continuously with the temperature, an inflexion point on the heating curves is observed. The electric field focusing effect within the dielectric rod makes up the strong decrease of dielectric losses of water (capacity to convert electromagnetic energy into heat at 2. 45 Ghz). These thermal runaways are interpreted in term of jump between two stable branches (bistability)
Beraud, Valérie. "Influence des agents tensioactifs sur les réactions de nitration anodique et d'hydrogénation électrocatalytique de composés organiques en phase aqueuse." Lyon 1, 1993. http://www.theses.fr/1993LYO10166.
Повний текст джерелаPierrot, André. "Contribution a l'étude des transferts de chaleur à haute température dans les milieux alvéolaires." Perpignan, 1987. http://www.theses.fr/1987PERP0032.
Повний текст джерелаMartin-Biegalke, Catherine. "Dégradation par l'eau et la chaleur des résines urée-formol." Nancy 1, 1993. http://www.theses.fr/1993NAN10187.
Повний текст джерелаPeillex-Tran, Anh Van. "Contribution à l'étude des interactions micro-ondes-matière condensée : application à quelques exemples de la chimie organique." Lyon 1, 1994. http://www.theses.fr/1994LYO10235.
Повний текст джерелаAmokrane, Nabil. "Comportement thermoanalytique et mécanique du silicate de calcium hydrate en fonction de ses conditions de formation." Lyon, INSA, 1992. http://www.theses.fr/1992ISAL0054.
Повний текст джерелаThe aim of this work was to establish correlations between the development of mechanical compressive strength Rc and both the amount and the nature of hydrated calcium silicates (C-S-H) formed during hydraulic set of Pure Ordinary Portland Cement (O. P. C. ) or of reactive phases added with O. P. C. Or lime. The C-S-H contents were determined by D. T. A. , while the nature of the hydrate were determined by X-Ray diffraction. Experimentation has shown that this objective could not be reached if the samples were dried, at 50°C before A. T. D. Tests. This limit temperature affects very sensitively the thermat stability of C-S-H compounds whatever was the system investigated. A correlation was possibly obtained only in the case of the simplest system, "silica fume - lime", when samples were dried at 25° C. However, this work has allowed to obtain new informations about C-S-H formation kinetics and about the improving of O. P. C. Strengths by addition of some reactive phases
Duveau, Venceslas. "Nouveau modèle de tolérance épileptique par préconditionnement hyperthermique : mise au point et étude du rôle de la PSA-NCAM." Bordeaux 2, 2005. http://www.theses.fr/2005BOR21286.
Повний текст джерелаA substantial number of data highlights the "brain tolerance" phenomenon as an outstanding window for investigating endogenous neuroprotective mechanisms. In the first part of this dissertation we show, both in vitro and in vivo, that kainate-induced cell damage in the hippocampus is reduced 1 to 10 days after exposure to heat shock. This neuroprotective effect is also accompanied by a weak anticonvulsant effect. In the second part we show that hyperthermia upregulates PCA-NCAM expression in the dentate gyrus of the hippocampus. Blockade of heat shock-induced HSP70 expression by quercetin significantly prevents upregulation of PSA, whereas triggering HSP70 expression by linolenic acid also upregulates PSA. Interestingly, we show that the heat-shock induced neuroprotection was abrogated when PSA was removed from NCAM using an enzymatic process. Upregulation of PSA-NCAM expression following hyperthermia may have significant impact on hippocampal plasticity
Prana, Vinca. "Approches structure-propriété pour la prédiction des propriétés physico-chimiques des substances chimiques." Paris 6, 2013. http://www.theses.fr/2013PA066304.
Повний текст джерелаThe EU regulation REACH requires, before 2018, the evaluation of toxicological, eco-toxicological and physico-chemical properties of substances produced or imported for more than one ton per year in Europe. Taking into account the number of substances and properties the measurement of all the data is not realistic. Thus, the development of alternative predictive methods for the evaluation of the properties of substances was recommended. The objective of this thesis, integrated in the French PREDIMOL project, was the development of predictive QSPR models (Quantitative Structure-Property Relationship) of the characterization of physico-chemical properties of organic peroxides. An experimental database relative to the explosive properties of about a hundred organic peroxides was identified but the variations in terms of concentration and diluents did not allow the development of validated QSPR models. From the building of a reliable and homogeneous experimental database of 38 organic peroxides, the first validated multi-linear QSPR models according to the OECD principles for the validation of QSAR/QSPR models were developed for the prediction of the heat and the temperature of decomposition. Several training sets, obtained by different ways (property range or principal components analysis) and also various types of descriptors (constitutional, topological, geometrical or quantum chemical) were used for the development of the QSPR models. Models were also developed for the density and the flash point
Ftaiti, Foued. "Contribution à l'étude de l'hyperthermie lors d'une course prolongée." Aix-Marseille 2, 2000. http://www.theses.fr/2000AIX22081.
Повний текст джерелаJoffrey, Philippe de. "Compensation en température de la fréquence d'un oscillateur à quartz par module intégré de calcul analogique." Besançon, 1989. http://www.theses.fr/1989BESA2009.
Повний текст джерелаDuprat, de Paule Sébastien. "Synthèse de nouvelles diphosphines chirales par atropoisomérie : utilisation en catalyse asymétrique et étude de l'influence des paramètres stériques et électroniques en hydrogénation asymétrique." Paris 6, 2002. http://www.theses.fr/2002PA066113.
Повний текст джерелаMichaut, Chloé. "Nouveaux effets thermiques transitoires en Géologie : des continents aux systèmes volcaniques." Paris, Institut de physique du globe, 2006. http://www.theses.fr/2006GLOB0001.
Повний текст джерелаDebard, Virginie. "Les mécanismes de la vulnérabilité à la chaleur : implication des stress systémique et cellulaire." Lyon 1, 2007. http://tel.archives-ouvertes.fr/docs/00/20/37/25/PDF/these_definitif_corrigee.pdf.
Повний текст джерелаHeat stroke is a serious illness without specific treatment. Heat stroked animals exhibit inflammatory processes accompanied by metabolic imbalance. These impairments take place despite of heat shock proteins (Hsp70) induction and glucocorticoid secretion. The role of Hsp70 mRNA and glucocorticoids in heat tolerance has been analyzed. Vigil animals intolerant to heat present: severe hyperthermia and dehydration, metabolic imbalance, lesser glucocorticoid production, signs of cellular hyperactivation and aggression, activation of inflammatory processes. The Hsp70 mRNA expression depends on the intensity of the stressor and appears, in the chain of causality, as a consequence of the heat aggression. Glucocorticoids are involved in tolerance by reducing local inflammatory processes and favouring the expression of the inhibitory factor κBα (IκBα) mRNA
Vrana, Joelle. "Evaluation de l'hyperthermie localisée autour de la trace d'un laser chirurgical CO2 à l'aide du modèle biologique de la lignée cellulaire V79." Toulouse 3, 1989. http://www.theses.fr/1989TOU30189.
Повний текст джерелаAndrade, Molenda Carlos Henrique de. "Influence des effets d'hysteresis sur les phénomènes de transferts couplés de chaleur et masse en milieux poreux." Toulouse, INPT, 1991. http://www.theses.fr/1991INPT066H.
Повний текст джерелаMatine, Abdelghani. "Homogénéisation des transferts thermiques par développements asymptotiques dans des structures composites avec prise en compte des effets de bord." Ecole centrale de Nantes, 2013. http://www.theses.fr/2013ECDN0008.
Повний текст джерелаThis work deals with the homogenization of heat transfer by conduction in heterogeneous and multiscale materials as fibre reinforced composites with a polymer matrix. Among various existing methods, we are interested in the asymptotic expansions. It allows the determination of the effective conductivity tensor by solving a problem on the periodic cell characterizing the structure. Heat transfer problem is then modeled ona macroscopic scale with the homogenized behavior. The method can be extended to non-periodic case if a REV (Representative Elementary Volume) was determined. This provides a good approximation of the field heat flux and temperature inside the structure (far enough from the boundaries). However, edge effects exist close the boundaries of the studied domain, which degrades the quality of the approximation. To correct them, two approaches have been developed. The first one consists in adding "boundary layer " terms, which tend to zero as the distance from the boundaries increases. The depth of the affected area is determined by solving an eigenvalue problem. The second approach (Arlequin Method) allows for the capture the edge effects, connecting the heterogeneous model on the boundaries with the homogenized model over the whole structure. The periodic homogenization method was developed in stationary and transient regime and is then applied to the simulation of the "flash method" to illustrate the bias in the estimation of parameters when edge effects are neglected
Variot, Bruno. "Modélisation des transferts de chaleur par rayonnement dans les systèmes gaz-solide à haute température." Perpignan, 1993. http://www.theses.fr/1993PERP0165.
Повний текст джерелаBizri, Mohamed. "Effets de la température d'acclimatation sur la GDP-mannose ; Dolichylphosphate mannosyltransférase des microsomes de foie de truite : distribution et détermination des dolichols dans le foie de truite et de rat." Lyon 1, 1986. http://www.theses.fr/1986LYO19005.
Повний текст джерелаRenaud, Thierry. "Mesure et modélisation de la conductivité et de la diffusivité thermiques des produits alimentaires congelés et non congelés." Lyon 1, 1990. http://www.theses.fr/1990LYO10246.
Повний текст джерелаTalbi, Ilhem. "Amélioration, modélisation d'un calorimètre et mesure de la capacité thermique massique de gels de gélatine en congélation et en décongélation." Lyon 1, 1998. http://www.theses.fr/1998LYO10300.
Повний текст джерелаDe, Zwart Jacobus Adrianus. "Fast magnetic resonance temperature imaging for control of localized hyperthermia in medicine." Bordeaux 2, 2000. http://www.theses.fr/2000BOR28713.
Повний текст джерелаJoyeux-Faure, Marie. "Heat stress and myocardial protection." Université Joseph Fourier (Grenoble), 1999. http://www.theses.fr/1999GRE18004.
Повний текст джерелаMalakooti, Hossein. "Meteorology and air-quality in a mega-city : application to Tehran, Iran." Marne-la-Vallée, ENPC, 2010. http://www.theses.fr/2010ENPC1001.
Повний текст джерелаKrebs, Emmanuel. "Modélisation moléculaire ab initio des effets de morphologie en catalyse par les sulfures." Paris 6, 2008. http://www.theses.fr/2008PA066174.
Повний текст джерелаPadilha, José Carlos Fiad. "Influence de la chaleur sur le métabolisme énergétique et sa régulation chez les poulets en croissance." Tours, 1995. http://www.theses.fr/1995TOUR4023.
Повний текст джерелаOuellet, Véronique, and Véronique Ouellet. "Le stress de chaleur chez la vache laitière : effets sur les performances de production des troupeaux laitiers québécois." Doctoral thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/37553.
Повний текст джерелаL’objectif des travaux effectués dans le cadre de cette thèse étaient de fournir de l’information concernant les impacts du stress de chaleur dans les troupeaux laitiers québécois. Le programme de recherche présenté a été conçu en prenant en considération le climat de la province et l’unicité du contexte de production canadien. La relation entre les conditions climatiques mesurées dans six étables laitières québécoises et celles mesurées à des stations météorologiques a d’abord été investiguée. L’objectif était de vérifier si les données collectées aux stations météorologiques pouvaient servir de substitut aux données des étables afin de juger adéquatement du niveau de stress de chaleur des animaux. Les résultats ont démontré que la température ambiante mesurée à l’intérieur des étables était significativement (P < 0,001) plus élevée que celle mesurée aux stations météorologiques alors que le contraire a été observé pour l’humidité relative. Ultimement, cela s’est traduit par un indice de température-humidité (ITH) significativement moins élevé de 4,6 unités dans l’Est du Québec et de 3,7 unités dans le Sud-Ouest du Québec lorsque les données des stations météorologiques sont utilisées au lieu des données des étables dans les calculs d’ITH. Finalement, l’adaptation du calcul d’ITH en substituant les conditions moyennes des stations météorologiques par la température maximale et l’humidité relative minimale a permis une meilleure représentation des conditions de l’étable. Néanmoins, une différence significative (P < 0,05) a été mesurée entre l’ITH modifié et l’ITH de l’étable. À la lumière de ces résultats, il est recommandé d’adapter les seuils d’ITH associés aux impacts négatifs du stress de chaleur lorsque les données environnementales dérivées des stations météorologiques sont utilisées. Dans le deuxième projet, la relation entre les performances de production et la durée des épidoes de stress de chaleur a été caractérisée grâce à un modèle multivarié. Pour ce faire, une banque de données incluant plus de 600 000 contrôles de production de 34 360 vaches a été utilisée et bonifiée de données environnementales exprimées sous forme d’ITH estimé à partir de la station météorolgique la plus près. Tout d’abord, les régressions linéaires effectuées ont révélé qu’il existe un délai de 24 heures entre un stress de chaleur et les impacts négatifs qui lui sont associés. Les résultats ont aussi suggéré que le stress de chaleur avait un effet persistent de huit jours sur les performances de production. Des pertes de production de 20 g de gras suite à une exposition d’un à deux jours de stress de chaleur et des pertes de protéines variant de 20 à 30 g selon la parité de l’animal ont été mesurées après trois ou quatre jours de stress de chaleur. Toutefois, aucune relation (P > 0,05) n’a été mesurée entre les productions de lait et de lactose et la durée des épisodes de stress de chaleur. Dans la troisième étude, les performances de production des vaches de la banque de données décrite précédemment ont été simulées pendant une période de référence (REF : 1971‒2000) et projetées pendant deux horizons futurs (FUT1: 2020‒2049; FL: 2050‒2079). L’objectif était de caractériser l’évolution des diminutions des composants laitiers associées au stress de chaleur et d’en chiffrer l’impact économique. Tout d’abord, les ITH quotidiens des trois périodes temporelles ont été calculés grâce aux données environnementales dérivées de six scénarios climatiques. Ensuite, le modèle élaboré dans la précédente étude a été adapté afin de projeter les performances de production des vaches pour les trois périodes mentionnées. Globalement, les scénarios climatiques utilisés dans cette étude ont démontré que la fréquence, l’intensité ainsi que la durée des épisodes de stress de chaleur pourront augmenter dans le FUT1 et dans le FL comparativement à la période de référence. Dans la région de l’Est du Québec, des pertes moyennes de gras et de protéines de 2405 ± 10 et de 1990 ± 7 kg/année par troupeau ont respectivement été projetées dans le FUT1 comparativement à REF. Dans la région du Sud-Ouest du Québec, des pertes moyennes de gras et de protéines de 2361 ± 147 et de 2057 ± 17 kg/année par troupeau ont respectivement été projetées dans le FUT1 comparativement à REF. Comparativement à REF, les diminutions projetées dans le futur (FUT1 et FL) se sont traduites par des pertes économiques moyennes allant de 5,02 à 7,07 can$/hl dans les troupeaux de l’Est du Québec et allant de 4,75 à 6,99 can$/hl dans les troupeaux du Sud-Ouest du Québec.
The main objective of this thesis was to provide information about heat stress related production impacts in Québec dairy herds. The relationship between on-farm summer environmental conditions and data retrieved from local meteorological stations was first investigated on six dairy farms. Secondly, the relationship between measurements previously established was considered in order to verify if temperature-humidity index (THI) calculations with weather station data could be adapted to better represent on-farm conditions. The farms recruited in the study were located in two contrasting dairy regions of the Province: East (EQ) and Southwest Quebec (SWQ). Our results showed that in both regions ambient temperature (AT) was consistently higher (P < 0.001) on-farm compared to AT measured at the weather station. The opposite was observed with relative humidity (RH), as it was significantly lower on-farm in EQ and numerically (P > 0.05) lower in SWQ compared to RH extracted from weather stations. Overall, this led to lower (P < 0.001) THI by 4.6 and 3.7 units at the weather stations compared to within-barn conditions for EQ and SWQ farms, respectively. Hence, using local meteorological station data to estimate on-farm conditions would lead to an underestimation of heat stress level in dairy cows. Adapting THI calculations by including daily maximum AT, and minimum RH retrieved from local weather station instead of their average counterparts led to a better estimation of within-barn conditions. However, difference between THI measured on-farm compared to the adapted THI calculated with weather station data remained significant. Although the adaption allowed for a closer relation to on-farm conditions, THI calculated with weather station data should only be used to gauge heat stress level in cows when heat stress thresholds are adapted for such data. In a second study, the relationship between milk performance and the cumulative number of days with heat stress was investigated with a multivariate model. A 6-year dataset containing 606,031 milk analysis records for 34,360 Holstein dairy cows at different parities was matched with the corresponding daily maximum THI. On average, cows were exposed to heat stress conditions for 135.8 ± 5.9 days per year in SWQ and 95.3 ± 10.2 days per year in EQ. Cows experiencing heat-stress conditions produced on average less fat, protein, and energy-corrected milk and lower fat and protein concentrations (P < 0.05). The decrease in milk fat reached a maximum of 6 % after an exposure of 7 to 8 heat stress days in cows at parity of three or more. The association between heat stress exposition duration and milk and lactose yields was weak (P > 0.05). Ultimately, heat stress lowered milk fat and protein production but had little effect on milk volume output. Further research is necessary to understand better the mechanism underlying the effects of sporadic low-to-medium-intensity heat stress on dairy productivity. The objective of the third study was to project milk performance of Holstein dairy cows under different climate scenarios through a reference period (REF: 1971–2000), near future (NF: 2020–2049) and distant future (DF: 2050–2079) using a predictive multivariate model. Moreover, this study provided information about the evolution of economic losses due to decreases in milk components associated with heat stress in Québec, Canada. Daily ambient temperature and relative humidity were derived from six climate scenarios in order to calculate daily THI through REF, NF and DF. Secondly, the model developed in the prior study was adapted to project annual milk performance of 71 dairy herds located in EQ and SWQ during the three aforementioned time horizons. Under NF climate conditions and relative to the reference period, projected fat and protein yields declined respectively by 2405 ± 10 and by 1990 ± 7 kg/yr per herd in EQ whereas decreases reached 2361 ± 147 and 2057 ± 17 kg/yr per herd in SWQ. Relative to the reference period, decreases in major milk components reached a maximum during DF in both regions. Ultimately, projected milk components declines resulted in average economic losses ranging from 5.02 to 7.07 can$/hL per EQ herds and from 4.75 to 6.99 can$/hL per SWQ herds.
The main objective of this thesis was to provide information about heat stress related production impacts in Québec dairy herds. The relationship between on-farm summer environmental conditions and data retrieved from local meteorological stations was first investigated on six dairy farms. Secondly, the relationship between measurements previously established was considered in order to verify if temperature-humidity index (THI) calculations with weather station data could be adapted to better represent on-farm conditions. The farms recruited in the study were located in two contrasting dairy regions of the Province: East (EQ) and Southwest Quebec (SWQ). Our results showed that in both regions ambient temperature (AT) was consistently higher (P < 0.001) on-farm compared to AT measured at the weather station. The opposite was observed with relative humidity (RH), as it was significantly lower on-farm in EQ and numerically (P > 0.05) lower in SWQ compared to RH extracted from weather stations. Overall, this led to lower (P < 0.001) THI by 4.6 and 3.7 units at the weather stations compared to within-barn conditions for EQ and SWQ farms, respectively. Hence, using local meteorological station data to estimate on-farm conditions would lead to an underestimation of heat stress level in dairy cows. Adapting THI calculations by including daily maximum AT, and minimum RH retrieved from local weather station instead of their average counterparts led to a better estimation of within-barn conditions. However, difference between THI measured on-farm compared to the adapted THI calculated with weather station data remained significant. Although the adaption allowed for a closer relation to on-farm conditions, THI calculated with weather station data should only be used to gauge heat stress level in cows when heat stress thresholds are adapted for such data. In a second study, the relationship between milk performance and the cumulative number of days with heat stress was investigated with a multivariate model. A 6-year dataset containing 606,031 milk analysis records for 34,360 Holstein dairy cows at different parities was matched with the corresponding daily maximum THI. On average, cows were exposed to heat stress conditions for 135.8 ± 5.9 days per year in SWQ and 95.3 ± 10.2 days per year in EQ. Cows experiencing heat-stress conditions produced on average less fat, protein, and energy-corrected milk and lower fat and protein concentrations (P < 0.05). The decrease in milk fat reached a maximum of 6 % after an exposure of 7 to 8 heat stress days in cows at parity of three or more. The association between heat stress exposition duration and milk and lactose yields was weak (P > 0.05). Ultimately, heat stress lowered milk fat and protein production but had little effect on milk volume output. Further research is necessary to understand better the mechanism underlying the effects of sporadic low-to-medium-intensity heat stress on dairy productivity. The objective of the third study was to project milk performance of Holstein dairy cows under different climate scenarios through a reference period (REF: 1971–2000), near future (NF: 2020–2049) and distant future (DF: 2050–2079) using a predictive multivariate model. Moreover, this study provided information about the evolution of economic losses due to decreases in milk components associated with heat stress in Québec, Canada. Daily ambient temperature and relative humidity were derived from six climate scenarios in order to calculate daily THI through REF, NF and DF. Secondly, the model developed in the prior study was adapted to project annual milk performance of 71 dairy herds located in EQ and SWQ during the three aforementioned time horizons. Under NF climate conditions and relative to the reference period, projected fat and protein yields declined respectively by 2405 ± 10 and by 1990 ± 7 kg/yr per herd in EQ whereas decreases reached 2361 ± 147 and 2057 ± 17 kg/yr per herd in SWQ. Relative to the reference period, decreases in major milk components reached a maximum during DF in both regions. Ultimately, projected milk components declines resulted in average economic losses ranging from 5.02 to 7.07 can$/hL per EQ herds and from 4.75 to 6.99 can$/hL per SWQ herds.
Reynard-Carette, Christelle. "Etude expérimentale de la convection thermocapillaire autour d'une bulle par méthodes optiques et thermiques : influence de la gravité sur les régimes d'écoulement et les transferts de chaleur." Aix-Marseille 1, 2001. http://www.theses.fr/2001AIX11056.
Повний текст джерелаSolal, Daniel. "Étude et réalisation d'un réflectomètre asservi en puissance pour le contrôle des séances d'hyperthermie radiofréquence." Paris 12, 1987. http://www.theses.fr/1987PA120033.
Повний текст джерелаArnaud, Claire. "Préconditionnement hyperthermique : mécanismes de la cardioprotection." Université Joseph Fourier (Grenoble), 2003. http://www.theses.fr/2003GRE18003.
Повний текст джерела