Teses / dissertações sobre o tema "Cristallographie à haute pression"
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Le, Cleac'h Andrée. "Contribution à l'étude des propriétés physiques des minéraux à haute pression : spectroscopie et calcul des grandeurs thermodynamiques de la lawsonite, des épidotes et des polymorphes de SiO /". Rennes : Centre armoricain d'étude structurale des socles, 1990. http://catalogue.bnf.fr/ark:/12148/cb35094086f.
Texto completo da fonteKadri, Adel. "Aspects physico-chimiques des effets de la pression sur la cristallogenèse des protéines". Université Louis Pasteur (Strasbourg) (1971-2008), 2004. http://www.theses.fr/2004STR13024.
Texto completo da fonteDerniaux, Eric. "Etude de structures NiCoCrAlY / Al2O3 / TiOx / Pt / AlN déposées par pulvérisation cathodique sur superalliage base Ni pour capteurs de pression haute température". Phd thesis, Caen, 2007. http://tel.archives-ouvertes.fr/tel-00444578.
Texto completo da fonteDjomani-Siawa, Doriane. "Hétérostructures allotropiques de semiconducteurs IV dans des nanofils : nouvelles opportunités more-than-Moore". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS074/document.
Texto completo da fonteWe have demonstrated an original way to induce a phase transformation in Si and Ge nanowires under external shear-stress. The transformation results in an unprecedented heterostructure with quasiperiodic embedded Ge-2H nanodomains distributed all along the nanowire. My thesisproject aims at understanding the mechanisms of this phase transformation and at characterizing the physical properties of the heterostructures 2H/3C in Si and Ge nanowires.We have carried out systematic structural analysis in Si- and Ge-2H/3C nanowires to evidence the key parameters of this phase transformation.The phase transformation occurs in shear bands localized along the (2-5-5) direction.The heterostructured nanowires are defined by a specific orientation relationship between the 3C and the 2H bands (both in Si and Ge nanowires)given by(1-10)3C//(-2110)2H and (110)3C//(0001)2H with the 2H bands lying mainly on (115)3C planes.The preliminary studies showed that shear-stress and the thermal budget above a threshold temperature of 350°C in Ge and 500°C in Si are mandatory for this transformation. These conditions meet the common criteria of a martensitic phase transformation. We have identified two key intrinsic parameters:the temperature and the nanowires crystallographic axis.In Si nanowires, we found that the formation of the shear bands i.e. the 2H nanodomains is related to the component of the shear-stress along the glide direction of the 3C/2H interface plane.Based on these results,the transformation could be consistent with a stress relief mechanism through the formation of (5-5-2)(1-15)3C shear bands.We have performed spatially resolved Raman measurements on single Si and Ge heterostructured nanowires to characterize their optical phonon modes.In Ge,we have detected 2 Raman bands at 288 cm⁻ ᴵ and 301 cm⁻ ᴵ attributed to the E2g and E1g + A1g + F2g modes.In Si, we have observed 3 Raman bands at 498, 515 and 520 cm⁻ ᴵ that are associated respectively to the E2g, A1g and F2g modes.Those values agree well with the literature.Moreover, we have performed Fourier Transform Infrared spectroscopy on transformed Ge nanowires to measure the optical band gap of the 2H phase.We have obtained a direct band gap of 0,58 eV attributed to the 2H phase and an indirect bandgap of 0,72 eV that might stem from the 3C phase. Those results are the first experimental data of the Ge-2H band gap.The values align well with the simulations that predict a narrow direct band gap for this structure.The 2H structure can also be achieved in bulk Si and Ge after unloading of the BC8 phase in a diamond anvil cell.The BC8 phase is unstable and convertsinto the 2H phase at room temperature in Ge or by thermal annealing in Si.In order to compare the bulk properties of the 2H phase, we have performedin-situ Raman and X-ray diffraction experiments in bulk samples by studyingvarious unloading pathways. In particular, unloading at room temperature ledto the formation of the ST12 phase or a mixture of the BC8 and ST12 phasesdepending on the unloading rate.The formation of the 2H phase is thuscomplex given its dependency on the unloading conditions and the hydrostaticconditions within the cell that are difficult to garanty. Our studies also reveala size effect. After unloading of Ge-3C nanowires, the nanostructures revertback to the 3C phase with an amorphous component detected.In addition, we have carried out in-situ band gap measurements in bulk Ge and Ge nanowires as a function of pressure.After unloading, we havemeasured optical gap values that are related to the band structure of theGe-ST12 allotrope with a direct bandgap of 0,53 eV and an indirect bandgapof 0,73 eV.Those results are consistent with the experimental values reported.The experiments on Ge nanowires showed an hysteresis behavior with theinitial value of the band gap measured after unloading.Those results clearly evidenced novel relaxation mechanisms at the nanoscale that need to be investigated
Rosenbaum, Eva. "Caractérisation structurale, enzymatique et biophysique d'un complexe peptidase piezo-thermophile issue de l'archaea marine abyssale Pyrococcus horikoshii". Phd thesis, Grenoble 1, 2008. http://www.theses.fr/2008GRE10298.
Texto completo da fonteRecently Franzetti et al. Discovered a new type of energy-independent self-compartmentalized proteases in Archaea. The particles were named TET for their tetrahedral three-dimensional structure. The TETs self assemble as large molecular weight complexes of about 500kDa. Their role in the organism is yet unknown. In P. Horikoshii, a hyperthermophilic Archaea from the deep sea, three TET proteases have been identified (PhTET1, 2 and 3). We have expressed and purified recombinant PhTET3. The enzyme was characterized biochemically and we determined the structure of a PhTET3 12 subunit complex by x-ray crystallography. In order to gain insight into its potential physiological role and to ascertain why there are three TET proteases in P. Horikoshii, the structure and the enzymatic properties of PhTET3 have been compared to the two other TET proteases that were characterized before. As self-compartmentalization plays an important role in functioning and regulation of proteases, the factors controlling PhTET3 oligomerization in vitro have been studied by analytical ultracentrifugation and small angle neutron scattering. Finally, under physiological deep sea conditions, the enzyme is exposed to high temperature (up to 100°C) and high pressure. In order to study the limits of stability of large molecular weight assemblies, the low-resolution structure and the enzymatic activity of PhTET3 have been monitored under high pressures and temperatures using small angle x-ray scattering and high-pressure spectrophotometry. Taken together, these studies revealed that the TET proteases of P. Horikoshii form an integrated peptide degradation systems and that PhTET3 exhibits unusual stability under high pressure and temperature as well as environment-associated enzymatic properties
Occelli, Florent. "Physique de l'hydrogène à haute pression". Paris 6, 2002. http://www.theses.fr/2002PA066453.
Texto completo da fontePicart, Laetitia. "Nouveaux procédés de conservation des aliments : champs électriques pulsés, traitements combinés haute pression-basse température, homogénéisation haute pression". Montpellier 2, 2004. http://www.theses.fr/2004MON20227.
Texto completo da fonteWeck, Gunnar. "Etude des propriétés de l'oxygène sous haute pression et haute température". Paris 6, 2001. http://www.theses.fr/2001PA066251.
Texto completo da fonteTripathi, Amita. "Structure des flammes cryotechniques à haute pression". Châtenay-Malabry, Ecole centrale de Paris, 2001. http://www.theses.fr/2001ECAP0702.
Texto completo da fonteProietti, Arnaud. "Rhéologie d'agrégats olivine-orthopyroxène sous haute pression". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30171/document.
Texto completo da fonteThis thesis presents our work on the rheology of two of the main minerals of the upper mantle: olivine and orthopyroxene. First, fined-grained polycrystalline aggregates (with grain sizes between 100 nm and 5 &m) of olivine and pyroxene were synthesized by Spark Plasma Sintering (SPS) and vacuumsintering. The samples were then deformed at pressures between 2 and 6 GPa in D-DIA presses installed on synchrotrons X-ray beamlines at NSLS and ESRF so thatmeasurements of the differential stress and strain could be obtained in situ. The influence of pressure on low-temperature plasticity of olivine was studied at room temperature (ID06 beamline, ESRF synchrotron, Grenoble). High-temperature deformation mechanisms of olivine and orthopyroxene were also studied between 900 and 1200°C (X17B2 beamline, NSLS synchrotron, New York). Mechanical results and microstructural analysis by EBSD suggest a deformation by diffusion creep. Rheological laws including the effect of pressure, temperature, differential stress and grain size were determined for each mineral. Under these conditions, orthopyroxene appears less viscous than olivine. Finally, two-phase aggregates (Ol/Px volume ration of 80/20 and 70/30) were also deformed. Differential stress, estimated in each phase, indicates the contribution of a second deformation mechanism, in agreement with microstructural observations
Champallier, Rémi. "Déformation expérimentale à Haute Température et Haute Pression de magmas partiellement cristallisés". Phd thesis, Université d'Orléans, 2005. http://tel.archives-ouvertes.fr/tel-00008988.
Texto completo da fonteLes travaux entrepris à haute température - haute pression (HT-HP) se proposaient d'étudier ce phénomène ainsi que la rotation des cristaux. Une telle étude nécessite de disposer d'un appareil de déformation des magmas fonctionnant à HT-HP. Ce mémoire présente les tests de deux appareils développés dans cette optique ainsi que ceux réalisés en presse Paterson. Une large place est également consacrée aux artefacts expérimentaux rencontrés et aux moyens mis en œuvre pour les résoudre.
Carrier, Hervé. "Contribution à l'étude thermodynamique de solutions d'électrolytes sous haute pression, haute température". Pau, 1996. http://www.theses.fr/1996PAUU3018.
Texto completo da fonteBouhifd, Mohammed Ali. "Physique des minéraux et des magmas à haute pression et haute température". Paris 7, 1995. http://www.theses.fr/1995PA077167.
Texto completo da fonteGougeon, Pierre. "Interactions aérodynamiques entre une turbine haute pression et le premier distributeur basse pression". Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0026/document.
Texto completo da fonteImproving the performance of current aeronautical turbines is an important issue in a context of severe economical and environmental constraints. In a turbofan, the inter-turbine channel which is located between the High-Pressure (HP) turbine and the first Low Pressure (LP) vane is characterized by a complex flow. Therefore aerodynamic structures coming from the HP turbine (wakes, vortices and showkwaves) strongly interact between each other and affect the LP vane flow field. This generates efficiency losses of the overall configuration. This PhD thesis aims at studying the aerodynamic phenomena between a HP turbine and the first LP vane and at analyzing the mechanisms creating aerodynamic losses. A previous experimental campaign, which was carried out on a facility including a HP turbine coupled to a LP vane, enabled to gather flow field measurements in planes located in the inter-turbine channel and downstream of the LP vane. In comparison with these experimental data, the numerical simulations done with elsA software intend to reproduce accurately the 3D, unsteady and turbulent nature of the flow within this configuration. The work can be divided into three mains steps. As a first step, steady simulations with a sliding mesh treatment enable to understand the general aspects of the flow. An assessment of the effects of RANS (Reynolds-Averaged Navier-Stokes) turbulent predictions and of spatial numerical schemes on the aerodynamic structures present in the configuration is carried out. As a second step, the advanced turbulence approach ZDES (Zonal Detached-Eddy Simulation) is considered for the LP vane flow prediction. The unsteady aerodynamic structures coming from the upstream HP rotor are set as an inlet boundary condition of the computational domain. The ZDES approach is compared to a URANS (Unsteady RANS) approach on the same computational domain. The generation and dissipation of the wakes and vortices are significantly different on the two simulations, and thus impact the creation of aerodynamic losses. Finally, URANS simulations enable to better understand the interaction effects between the different blade rows. First, the unsteady phase-lagged approaches that take into account a single rotor and stator assess the important unsteady effects in the inter-turbine channel. They finally lead to the implementation of a multipassages phase-lagged computation that takes into account the two stators and the rotor in order to model all the existing determinist interactions. In order to quantify them accurately, a modal decomposition of the unsteady flow field is set up. The interaction levels linked to the different blade rows are therefore quantified and the impact of the aerodynamic losses is evaluated
Sdanghi, Giuseppe. "Développement d’un compresseur hybride d’hydrogène : électrochimique à basse pression/adsorption à haute pression". Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0145.
Texto completo da fonteThe proof of concept of a non-mechanical hydrogen compressor has been carried out in the present study. It is a hybrid compressor since it consists of: (i) a first electrochemical compression step, which compresses hydrogen from 1 bar up to 40-80 bar and; (ii) a second compression step based on the thermally-driven cyclic adsorption-desorption which allows compressing hydrogen up to 700 bar. Numerical models have been developed to verify the feasibility of such a system, and their validity has been proved by the experimental data obtained with the prototypes built for each of the two compression stages. Concerning the electrochemical compressor, a current density distribution along the electrochemical was observed using a segmented cell, and the developed pseudo-2D model proved that the stability of the current density strictly depends on the local water content of the membrane. Indeed, the current density was found to decrease from 0.75 A/cm2 to 0.65 A/cm2 between the first and the last segment of the compressor, which corresponds to a decrease of the relative humidity in the inlet hydrogen flow from 90% to 55% along the gas channels at the anode side (at 0.66 A/cm2 x 0.36 V and 333 K). Concerning the adsorption-desorption compressor, the Modified Dubinin-Astakhov model (MDA) was implemented to describe hydrogen adsorption on activated carbons as a function of the temperature and the pressure. It was used along with the mass and the energy balance equations to study the feasibility of such a compressor. The results from the numerical simulation were validated with the experimental data, which were obtained using a prototype of 0.5 L, designed and built for the present study, and containing 0.135 kg of the activated carbon MSC-30 (Kansai, Japan). 30 NL/h of high-pressure hydrogen at 700 bar were obtained when introducing hydrogen at 80 bar into the compressor, previously cooled to 77 K, and when heating it up to 315 K. The proposed hybrid hydrogen compressor could be a valid alternative to traditional mechanical compressors, and it could be used in small and decentralized facilities using hydrogen as a fuel, e.g. a hydrogen refuelling station
Millot, Marius. "Spectroscopies sous haute pression et champ magnétique intense". Phd thesis, Université Paul Sabatier - Toulouse III, 2009. http://tel.archives-ouvertes.fr/tel-00436291.
Texto completo da fonteGagné-Dumais, Laurent. "Étude de composés binaires denses sous haute pression". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/33407.
Texto completo da fonteMosbah, Smaïne. "Thermodynamique des mélanges CO₂-hydrocarbure sous haute pression". Paris 11, 1987. http://www.theses.fr/1987PA112284.
Texto completo da fonteHubert, Christophe. "Etude de la langatate (La3Ga5,5Ta0,5O14) sous haute pression". Paris 7, 2005. http://www.theses.fr/2005PA077028.
Texto completo da fonteMosbah, Smaïne. "Thermodynamique des mélanges CO-hydrocarbures sous haute pression". Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37608172f.
Texto completo da fonteMontagnac, Gilles, e Gilles Montagnac. "Spectroscopie Raman résonnante UV in situ à haute température ou à haute pression". Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2012. http://tel.archives-ouvertes.fr/tel-00790770.
Texto completo da fonteBoudot, Aline. "Propriétés des revêtements de protection haute température pour pales de turbine haute pression". Toulouse, INPT, 1999. http://www.theses.fr/1999INPT034G.
Texto completo da fonteThe aim of this work was the characterization of the vacuum plasma sprayed or electrodeposited NiCoCrA1YTa coating, used for protection of H. P. Turbine blade. First, both massive coatings were characterized in terms of physico-chemical and mechanical properties. The electrodeposited alloy shows a less homogenous distribution of β and γ phases and, in this coating, yttrium is segregated in the material as oxides and precipitates. These distinctive features induce mechanical spallation of the oxide scales and lower mechanical properties for the electrodeposited coating. Then, influence of protective coatings on nickel-base single crystal superalloy was characterized. Few differences were observed between the vacuum plasma sprayed coating and the electrodeposited one. The coating effect is mainly dependant on its ductile or brittle behaviour. If the mechanical solicitations of the substrate/coating system are applied in the brittle field of the coating, this one presents a detrimental effect. In the other case, a positiv effect of the coating is observed which comes from the protection of substrate against environmental degradation
Taupin, Benoît. "Etude de la combustion turbulente à faible richesse haute température et haute pression". INSA de Rouen, 2003. http://www.theses.fr/2003ISAM0010.
Texto completo da fonteMeducin, Fabienne. "Etude des phases silicatées du ciment hydraté sous haute pression et haute température". Paris 6, 2001. http://www.theses.fr/2001PA066337.
Texto completo da fonteMontagnac, Gilles. "Spectroscopie Raman résonnante UV in situ à haute température ou à haute pression". Thesis, Lyon, École normale supérieure, 2012. http://www.theses.fr/2012ENSL0784/document.
Texto completo da fonteI applied UV resonant Raman spectroscopy (UVRRS) to an ‘in situ’ study of carbon materials at very hight temperature (> 2000 K) or at high pressure (< 1 GPa).The advantages of UVRRS are presented in the first part of this PHD thesis, and used to investigate details of the composition and structure of disordered carbon materials such as: (1) n-type nanocrystalline films, (2) carbonaceous matter in chondrites and (3) tholins, HCN synthetic samples of Titan 's atmosphere.‘In situ’ Raman studies are limited to 2000 K by the visible black-body emission. I designed a high temperature cell to perform UVRRS above this limit. The second part of the manuscript presents Raman spectra of pyrolitic graphite and HOPG up to 2700 K. This data are consistent with anharmonic models up to 900 K, and show the coupling effects of electron-phonon and phonon-phonon. The last one dominates the anharmonicity above 1000 K. The Raman spectra was calibrated as a function of temperature and became a “thermometer” up to 2700 K.For high pressure measurements in the third part, I modified an anvil cell to study by UVRRS, the vibrational changes induced by pressure on very luminescent molecular organic crystals. I present an analysis at 244 nm of resonant Raman modes of perylene crystal under hydrostatic pressure up to 0.8 GPa. Some of them have a non linear feature under pressure, revealing structural and planar modifications of the molecules
Watson, Guillaume. "Masse volumique et viscosité dynamique sous haute pression de mélanges alcool+hydrocarbures et mise au point d'un conductimètre électrique haute pression". Pau, 2007. http://www.theses.fr/2007PAUU3010.
Texto completo da fonteThis work is related to the study of density and dynamic viscosity under pressure of alcohol + hydrocarbon mixtures, and development of high pressure electrical conductimeter. Density of ethanol + n-heptane and (n-butanol or n-propanol) + toluene binaries has been measured as a function of the pressure (up to 65 MPa), the temperature (from 293 to 353 K) and the composition (5 pure compounds and 7 mixtures by binary), resulting on 2638 experimental points. With supplementary data from the literature on the 2 binaries ethanol + (methylcyclohexane or toluene), it has been possible to discuss on the volumic properties of the 5 binaries and on evaluation of predictive model PC-SAFT. Dynamic viscosity of ethanol + (toluene or n-heptane) binaries has been measured as a function of the pressure (up to 100 MPa), the temperature (from 293 to 353 K) and the composition (3 pure compounds and 7 mixtures by binary), resulting on 394 experimental points. These data have been analysed with some predictive models: mixing laws, models of hard spheres, free volume, friction theory and molecular dynamic. An electrical conductimeter has been developed in order to measure high electrical conductivity of petroleum brine (up to 2000 mS. Cm-1) under high pressure and high temperature. Bibliographic study has allowed to choose the direct contact method with 4 electrodes and alternative current. Measurements of KCl and LiCl aqueous solutions, with concentration from 0. 1 to 4. 5 Molal, up to 100 MPa and at 298 K, have permitted to valid the device in this range of measurement, with a precision of ± 3 %
Motto-Ros, Vincent Rairoux Patrick. "Cavités de haute finesse pour la spectroscopie d'absorption haute sensibilité et haute précision application à l'étude de molécules d'intérêt atmosphérique /". Villeurbanne : Université Claude Bernard, 2005. http://tel.archives-ouvertes.fr/docs/00/06/43/97/PDF/these_VMR.pdf.
Texto completo da fonteFillaux, Clara. "Etude structurale et vibrationnelle du chlorure de zinc à haute pression et haute température". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00007985.
Texto completo da fonteKaczorowski, Damien. "Usures d'un acier inoxydable austénitique dans de l'eau à haute pression et haute température". Ecully, Ecole centrale de Lyon, 2002. http://www.theses.fr/2002ECDL0010.
Texto completo da fonteLe, Bail Alain. "Contribution a l'etude des transferts thermiques couples a haute temperature et a haute pression". Nantes, 1990. http://www.theses.fr/1990NANT2023.
Texto completo da fonteSeront, Bernard. "Déformation expérimentale à haute pression et haute température d'agrégats polycristallins de plagioclase et d'olivine". Montpellier 2, 1993. http://www.theses.fr/1993MON20139.
Texto completo da fonteDewaele, Agnès. "Équations d’état à haute pression et haute température des composants du manteau inférieur terrestre". Lyon, Ecole normale supérieure, 1999. http://www.theses.fr/1999ENSL0128.
Texto completo da fonteJouini, Zied. "Synthèse des clathrates dans le système silicium-sodium sous haute pression et haute température". Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS190/document.
Texto completo da fonteThe objective of this thesis is to study the synthesis and thermodynamics of intermetallic clathrates of the Na-Si system, which are the important materials for thermoelectric applications and are the promising precursors for new forms of Si for the photovoltaic and photonic applications. In this work the formation of the Na-Si clathrates have been studied in situ and ex situ at high pressure and high temperature. A number of new forms of silicon have been observed while heating the clathrates under vacuum. Under pressures below 3 GPa the clathrates does not form by the interaction of elements. Instead, the silicide Na4Si4 forms and remains stable up to melting. Above 3 GPa, Na4Si4 formed in the beginning of the heating, react with the excess of Si and gives Na30Si136 (structure II) and after that, if Na30Si136 react with the excess of Si, to form Na8Si46 (structure I) below 7 GPa and the clathrate NaSi6 above 7 GPa. The experiments have been performed by using the standard Paris-Edinburg cell (opposite anvils) up to 6 GPa and multianvil press for pressures above 6 GPa. The strong sensibility of the crystallization product to the concentration of sodium has been observed. The diagram of transformations in clathrates for pressures between 0 and 10 GPa and temperatures between 300 and 1500 K has been proposed. The phase diagram (concentration – temparature at 4 GPa) that represents the observed transformations and stability domains has been also proposed and suggests the existence of three eutetic equilibria: between Si and structure I, between structures I and II, and between structure II and Na4Si4. To understand the thermodynamics and interactions in the system Na-Si, the modelisation of phase diagram at ambient pressure has also been performed that allowed us to establish the thermodynamic characteristics of melting and the equations of observed liquidi. To take into account the impact of pressure on the thermodynamics, the p-V-T equations of state of diamond Si, structure I and high-pressure form of structure II have been used
Majerus, Odile. "Etudes structurales de verres d'oxyde en conditions de haute température ou de haute pression". Paris 6, 2003. http://www.theses.fr/2003PA066549.
Texto completo da fonteJouini, Zied. "Synthèse des clathrates dans le système silicium-sodium sous haute pression et haute température". Electronic Thesis or Diss., Sorbonne université, 2018. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2018SORUS190.pdf.
Texto completo da fonteThe objective of this thesis is to study the synthesis and thermodynamics of intermetallic clathrates of the Na-Si system, which are the important materials for thermoelectric applications and are the promising precursors for new forms of Si for the photovoltaic and photonic applications. In this work the formation of the Na-Si clathrates have been studied in situ and ex situ at high pressure and high temperature. A number of new forms of silicon have been observed while heating the clathrates under vacuum. Under pressures below 3 GPa the clathrates does not form by the interaction of elements. Instead, the silicide Na4Si4 forms and remains stable up to melting. Above 3 GPa, Na4Si4 formed in the beginning of the heating, react with the excess of Si and gives Na30Si136 (structure II) and after that, if Na30Si136 react with the excess of Si, to form Na8Si46 (structure I) below 7 GPa and the clathrate NaSi6 above 7 GPa. The experiments have been performed by using the standard Paris-Edinburg cell (opposite anvils) up to 6 GPa and multianvil press for pressures above 6 GPa. The strong sensibility of the crystallization product to the concentration of sodium has been observed. The diagram of transformations in clathrates for pressures between 0 and 10 GPa and temperatures between 300 and 1500 K has been proposed. The phase diagram (concentration – temparature at 4 GPa) that represents the observed transformations and stability domains has been also proposed and suggests the existence of three eutetic equilibria: between Si and structure I, between structures I and II, and between structure II and Na4Si4. To understand the thermodynamics and interactions in the system Na-Si, the modelisation of phase diagram at ambient pressure has also been performed that allowed us to establish the thermodynamic characteristics of melting and the equations of observed liquidi. To take into account the impact of pressure on the thermodynamics, the p-V-T equations of state of diamond Si, structure I and high-pressure form of structure II have been used
Boudreau, Alex. "Contrôle actif du bruit acoustique des ventilateurs haute pression". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0034/MQ67250.pdf.
Texto completo da fonteJournaux, Baptiste. "Pétrologie et rhéologie des glaces planétaires de haute pression". Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2013. http://tel.archives-ouvertes.fr/tel-01017171.
Texto completo da fonteBoudreau, Alex. "Contrôle actif du bruit acoustique des ventilateurs haute pression". Mémoire, Université de Sherbrooke, 1998. http://savoirs.usherbrooke.ca/handle/11143/1076.
Texto completo da fonteBrun, Sulyvan. "Etudes structurales des conducteurs organiques bidimensionnels à haute pression". Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENY034/document.
Texto completo da fonteOrganic conductors based on charge-transfer salt of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET) exhibit electronic properties ranging from semiconducting to metallic to superconducting. Pressure can induce subtle structural rearrangements associated with drastic changes in physical properties. Study of the pressure induced structural changes of these compounds, with low symmetry unit cells containing dozens of light atoms, is a challenge. The aim of this work is to investigate pressure-induced structural changes with single crystal X-ray diffraction. Single-crystals of six organic conductors and superconductors (α-(BEDT-TTF)2I3, β-(BEDT-TTF)2I3, κ-(BEDT-TTF)2I3, α-(BEDT-TTF)2KHg(SCN)4, κ-(BEDT-TTF)2Cu(NCS)2, and κ-(BEDT-TTF)2Cu[N(CN)2]Br) were studied at high-pressures (up to 32 GPa) in a diamond-anvil cell on the ID09A beamline at the ESRF. Helium was used as pressure transmitting-medium. The compressibilities of the six compounds are reported, and atomic positions were determined under pressure. For the first time, reversible structural phase transitions in α-(BEDT-TTF)2I3 to αHP-(BEDT-TTF)2I3 at 13.6 GPa, and in κ-(BEDT-TTF)2Cu(NCS)2 to κHP-(BEDT-TTF)2Cu(NCS)2 at 8.5 GPa have been observed, and the original high pressure structures have been described successfully. Raman measurements agree well with the observed structural changes
Camelin, Christian. "Oxydation du silicium monocristallin sous haute pression d'oxygène sec". Bordeaux 1, 1985. http://www.theses.fr/1985BOR10583.
Texto completo da fonteNguyen, Jean-François. "Nouveaux composites thermopolymérisés sous haute pression pour la CFAO". Paris 13, 2013. http://scbd-sto.univ-paris13.fr/secure/edgalilee_th_2013_nguyen.pdf.
Texto completo da fonteThe evolution of restorative materials has resulted in biomaterials with improved mechanical and optical properties, such as ceramics and composites, responding to increased aesthetic demand from patients. Furthermore, the emergence of CAD / CAM lead to improved consistency in quality and avoidance of laboratory associated errors and provides access to new materials. Ceramics have good mechanical properties and excellent biocompatibility but are difficult to mill. Besides, they can not withstand plastic deformation, which leads to the risk of microfractures edges during milling, reoperation is difficult. Composites are easy to machine and can be easily repaired; however, their mechanical properties and biocompatibility are inferior to those of ceramics, because of their incomplete polymerization. The aim of this study was to obtain a process to produce a new class of dental composite blocs, suitable for CAD/CAM, by thermo-polymerisation at high pressure
BERTRAN, ALVAREZ YVES. "Interdiffusion fe-mg dans l'olivine naturelle sous haute pression". Paris 11, 1993. http://www.theses.fr/1993PA112049.
Texto completo da fonteSpendeler, Liliane. "Propriétés de transport d'YbCu4,5 et d'Yb à haute pression". Grenoble 1, 1992. http://www.theses.fr/1992GRE10175.
Texto completo da fonteBoudreau, Alex. "Contrôle actif du bruit acoustique des ventilateurs haute pression". Sherbrooke : Université de Sherbrooke, 1999.
Encontre o texto completo da fonteArbeau, Anne Charnay Georges. "Étude de l'entraînement d'air dans un spray haute pression". Toulouse : INP Toulouse, 2005. http://ethesis.inp-toulouse.fr/archive/00000029.
Texto completo da fonteCoxam, Jean-Yves. "Mise au point d'une méthode de mesure des capacités calorifiques à pression constante de solutions aqueuses salines à haute température et haute pression". Clermont-Ferrand 2, 1988. http://www.theses.fr/1988CLF21140.
Texto completo da fonteCoxam, Jean-Yves. "Mise au point d'une méthode de mesure des capacités calorifiques à pression constante de solutions aqueuses salines à haute température et haute pression". Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37612810k.
Texto completo da fonteAuzanneau, Estelle. "Etude expérimentale des relations de phases dans les métasédiments à haute pression et haute température". Phd thesis, Clermont-Ferrand 2, 2005. https://tel.archives-ouvertes.fr/tel-00677588/document.
Texto completo da fonteFiquet, Guillaume. "Proprietes thermodynamiques de mineraux du manteau superieur. Calorimetrie a haute temperature et spectroscopie a haute pression et haute temperature". Rennes 1, 1990. http://www.theses.fr/1990REN10144.
Texto completo da fonteENGUEHARD, FRANCOIS. "Pyrolyse haute pression du dibutylether : etude cinetique experimentale, effet des parametres pression et temperature, modelisation numerique". Paris 6, 1991. http://www.theses.fr/1991PA066110.
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