WorldCat Identities

Ferriol, Michel (19..-....).

Overview
Works: 23 works in 34 publications in 2 languages and 61 library holdings
Genres: Conference papers and proceedings 
Roles: Thesis advisor, Opponent, Other, Author, Editor
Classifications: QD503, 541.363
Publication Timeline
.
Most widely held works by Michel Ferriol
XXX JEEP : Journées d'étude des équilibres entre phases : Saint-Avold, France, 31 Mars-1er Avril 2004 by Journée d'étude des équilibres entre phases( Book )

2 editions published in 2004 in French and held by 28 WorldCat member libraries worldwide

Journées d'Étude des Équilibres entre Phases : XXX JEEP, Saint-Avold, France, 31 mars - 1er avril 2004 by Journées d'Étude des Équilibres entre Phases( Book )

3 editions published in 2004 in French and English and held by 4 WorldCat member libraries worldwide

Synthèse et caractérisation de polymères méthacryliques phosphorés à propriétés retardatrices de flamme by Anne Gentilhomme( Book )

2 editions published in 2003 in French and held by 2 WorldCat member libraries worldwide

Le Polyméthacrylate de méthyle PMMA trouve de nombreuses applications dans différents domaines de l'industrie, mais cependant il est facilement inflammable. Son ignifugation représente donc un enjeu commercial important. Une méthode classique consiste à ajouter l'ignifugeant au polymère mais souvent au détriment du comportement mécanique du matériau. Pour pallier ceci, nous avons donc fonctionnalisé ces polymères par des molécules phosphorés. Après leur caractérisation, l'étude de leur dégradation thermique, de leur comportement au feu, ainsi que celle des gaz émis lors de leur combustion et de leurs résidus, nous avons montré que ces nouveaux polymères avaient ds propriétés retardatrices de flamme meilleures que celles du PMMA. Cette voie est prometteuse mais nécessite d'être combiner avec des méthodes d'additivation afin d'améliorer leur comportement au feu et de réduire la libération de CO et de fumées
Contribution à l'étude des équilibres entre phases dans le système quaternaire PbO-Fe2O3-Sc2O3-Nb2O5 by Jean-Loïc Rivolier( Book )

2 editions published in 1994 in French and held by 2 WorldCat member libraries worldwide

DANS LE CADRE DE L'ETUDE DE LA SUBSTITUTION DU SCANDIUM PAR LE FER DANS LE COMPOSE FERROELECTRIQUE PBSC#0#.#5O#3, LES SYSTEMES BINAIRES PBO-FE#2O#3 ET PBO-NB#2O#5 ONT ETE ENTIEREMENT REETUDIES DU FAIT DES CONTRADICTIONS ET LACUNES DE LA BIBLIOGRAPHIE. DANS UN DEUXIEME TEMPS ET AFIN DE DETERMINER LES MEILLEURES CONDITIONS D'ELABORATION DE MONOCRISTAUX DE PBFE#0#.#5NB#0#.#5O#3, SON DOMAINE DE CRISTALLISATION DANS LE SYSTEME TERNAIRE PBO-FE#2O#3-NB#2O#5 A ETE DETERMINE EN S'APPUYANT SUR L'ETUDE DES COUPES ISOPLETHIQUES PB#2FE#2O#5-PB#2NB#2O#7 ET PBO-FENBO#4 ET SUR CELLE DES BINAIRES PRECEDENTS. ENFIN, LA COUPE ISOPLETHIQUE PBFE#0#.#5NB#0#.#5O#3-PBSC#0#.#5NB#0#.#5O#3 DU SYSTEME QUATERNAIRE PBO-FE#2O#3-SC#2O#3-NB#2O#5 A ETE TRACEE ET LES PROPRIETES CRISTALLOGRAPHIQUES DES COMPOSES PBFE#X#/#2SC(#1#-#X#)#/#2NB#0#.#5O#3 (0<X<1) AFIN QUE LES PARAMETRES THERMODYNAMIQUES DE LA TRANSITION FERROPARAELECTRIQUE CORRESPONDANTE ONT ETE DETERMINES
Polyméthacrylate de méthyle (PMMA) : Développement de nouveaux systèmes retardateurs de flamme à base de nanocharges minérales. Recherche de synergies avec des montmorillonites et des composés phosphorés by Abdelghani Laachachi( Book )

2 editions published in 2005 in French and held by 2 WorldCat member libraries worldwide

The poly(methyl methacrylate) (PMMA) is a very interesting thermoplastic polymer. It finds many applications in many sectors and particularly in the field of lighting (lamps, signs...). However, like many polymers, it is easily flammable and its fireproofing is an important commercial stake, especially as the norms in the matter are more and more stricts (halogen-free compounds). Among the methods of improvement of the fire resistance of polymers, one of the most used consists in incorporating in the polymeric matrix particles of inorganic compounds. Among those, clays of the montmorillonite type are particularly promising by ensuring the construction of a silicato-carbonized layer at the surface of the polymer during its combustion. Nevertheless, the majority of the performed studies show the need for using these lamellar particles in combination with other flame retardant additives in order to obtain a flame behaviour fully meeting the norms in use. Among these additives, are the metallic oxide nanoparticles. The principal objective of this work was the study of the effect of some metal oxides or hydroxides, with different features (size and specific surface area), on the thermal stability and fire resistance of PMMA. Then, synergies were investigated between the oxides considered as the most interesting (particularly, the nanometric ones) and an organo-modified montmorillonite (OMMT) or with various commercial phosphorated flame retardant additives
Study of the phase equilibria in the ternary systems X2O-Li2O-Nb2O5(X=Na, Rb, Cs), single crystal growth and characterization of LiNbO3 by Gabriella Dravecz( Book )

2 editions published in 2009 in English and held by 2 WorldCat member libraries worldwide

The versatility of the application of LiNbO3 is well-known in the practical fields of acousto-electronics and non-linear optics and electro-optics. The optical damage threshold of stoichiometric LiNbO3 is higher so it is more suitable for electo-optical and non-linear optical applications than the congruent crystal which can be grown easier. The growth difficulties justify the development of alternative preparation methods or the improvement of the existing methods. This emphasizes the importance of the growth of stoichiometric LiNbO3 by the HTTSSG method not only from the K2O - Li2O - Nb2O5 ternary system but from the X2O - Li2O - Nb2O5 (X = Rb, Cs) systems as well. Using the presented phase diagrams the composition of the solution in equilibrium with a custom-tailored crystal composition can be determined. Most of the physical parameters of LiNbO3 are composition dependent. Even a small change of the composition (± 0.01 mol%) causes large differences in the properties so the determination of the Li2O content of the crystal with the highest possible accuracy is very important. The accuracy of the composition determination - described in detail in my thesis - based on the intensity ratio of the two characteristic bands in the OH- vibrational spectra of the near stoichiometric LiNbO3 satisfies the requirements imposed by the applications
La génération de seconde harmonique comme technique complémentaire pour la caractérisation des poudres organiques. by Lina Yuan( )

2 editions published in 2017 in English and held by 2 WorldCat member libraries worldwide

The existence of different phases, including polymorphs, salts, solvates and co-crystals generates concerns in the characterization of solid-state materials, especially for the pharmaceutical industry. Issues related to the identification of phases and the monitoring of phase transitions and crystallisation processes cannot be always solved using conventionnal techniques. In this work, a complementary analytical approach based on the nonlinear optical phenomena of second harmonic generation (SHG) is developed. SHG is a sensitive and accurate technique to detect the absence of inversion center in the crystalline structure and to capture subtle symmetry changes. Herein, through several examples we show how Temperature-Resolved SHG (TR-SHG) measurements van be used to study phase diagrams and for tracking mechanisms and kinetics of phase transitions including order-disorder phase transitions. The combination of TR-SHG with classical techniques (XRPD, DSC and microscopy) reveals in this study the usefulness and the potentials of nonlinear optics in material characterization
Développement de nouveaux systèmes retardateurs de flammes à base de nanocomposites plus respectueux de l'environnement by Blandine Friederich( Book )

2 editions published in 2011 in French and held by 2 WorldCat member libraries worldwide

Suite aux restrictions réalisées par les Nations Unies et la Communauté Européenne concernant certains retardateurs de flammes halogénés, la demande actuelle du marché tend à se diriger vers des composés non halogénés, tels que les retardateurs de flammes phosphorés. Il est cependant nécessaire d'utiliser des taux de charges élevés pour obtenir des propriétés de résistance au feu intéressantes, ce qui entraîne une chute des propriétés mécaniques. Cela nous a amené à combiner une partie des composés phosphorés par des oxydes métalliques nanométriques, connus pour leur capacité à améliorer la stabilité du poly(méthacrylate de méthyle) (PMMA).Nous avons, dans un premier temps, étudié l'effet des nanoparticules (dioxyde de titane, alumine et boehmite) sur la diffusivité thermique du PMMA, permettant de mettre en évidence un mode d'action de ces additifs lors de la dégradation thermique du PMMA. Une partie de ces charges ont été, dans un deuxième temps, substituées par deux retardateurs de flammes phosphorés et azotés : le polyphosphate d'ammonium (APP) et le polyphosphate de mélamine (MPP). Dans les systèmes ternaires obtenus (APP/MPP/oxyde métallique), les propriétés de résistance au feu et de stabilité thermique ont été étudiées, ainsi que les mécanismes mis en jeu lors de la combustion. Les phases condensée et gazeuse ont été analysées à cet effet
Phénomènes de nucléation et de croissance cristalline dans les milieux de viscosité élevée : application à la cristallisation des deux formes stable et métastable du monohydrate de monométhylhydrazine by Valérie Palumbo( Book )

2 editions published in 1995 in French and held by 2 WorldCat member libraries worldwide

L'OBJECTIF DE CE TRAVAIL EST RELATIF A L'ETUDE DES PHENOMENES DE NUCLEATION ET DE CROISSANCE CRISTALLINE DANS LES MILIEUX DE HAUTE VISCOSITE. LES SOLUTIONS AQUEUSES DE MONOMETHYLHYDRAZINE AU VOISINAGE DE LA COMPOSITION X#M#M#H=0,5 ONT SERVI DE SUPPORT A CETTE ETUDE CAR ELLES PRESENTENT UNE GRANDE FACILITE A LA VITRIFICATION ET QU'IL EXISTE UNE TRANSFORMATION MONOTROPIQUE LENTE ENTRE DEUX FORMES ALLOTROPIQUES DU COMPOSE MMH-H#2O. LES PHENOMENES ONT ETE ETUDIES DU POINT DE VUE CINETIQUE EN ASSOCIANT DEUX TECHNIQUES EXPERIMENTALES: LA CALORIMETRIE DIFFERENTIELLE ET L'ABSORPTIOMETRIE. LES DOMAINES DE NUCLEATION ET DE CROISSANCE CRISTALLINE ONT ETE DELIMITES EN VUE DE DEFINIR UN TRAITEMENT THERMIQUE DES ECHANTILLONS INDUISANT DES EVOLUTIONS PHENOMENOLOGIQUES REPRODUCTIBLES ET COMPARABLES ENTRE ELLES. LES CONSTANTES CINETIQUES DE NUCLEATION ET DE CROISSANCE CRISTALLINES ONT ETE MESUREES ET UNE EVALUATION DES ENERGIES D'ACTIVATION A ETE FAITE. LES PHENOMENES ONT ETE MODELISES GRACE AU FORMALISME DE J.M.A. AU COURS DU RECUIT IL Y A CROISSANCE DE NUCLEUS PREEXISTANTS FORMES PENDANT LE TRAITEMENT THERMIQUE. CECI CONDUIT A UNE BONNE REPRESENTATION DES COURBES OBTENUES PAR ABSORPTIOMETRIE ET PERMET DE CALCULER LES CINETIUES DE NUCLEATION ET DE CROISSANCE CRISTALLINE DE CHACUNE DES FORMES DU COMPOSE MMH-H#2O, CONFIRMANT LES RESULTATS OBTENUS PAR CALORIMETRIE DIFFERENTIELLE
Croissance et caractérisation de fibres monocristallines de nouveaux matériaux pour microlasers bleus et UV by Nader Kozhaya( Book )

2 editions published in 2011 in French and held by 2 WorldCat member libraries worldwide

Blue and UV lasers are currently used for many applications as data storage, medicine, micromachining, etc. The frequency conversion by means of non-linear crystals appears as a good solution to obtain coherent light sources from usual solid lasers emitting in the IR, no UV laser effect can be produced in any crystal. In this frame, we studied three materials (K3Li2-xNb5+xO15+2x (KLN), Ca5(BO3)3F (CBF) and Bi2ZnB2O7 (BZBO)) which possess promising non-linear optical properties. In this work, we studied two phase diagrams: K2O-Li2O-Nb2O5 and CaO-B2O3-CaF2 in order to determine and optimize the growth conditions of the corresponding crystals.We showed that µ-PD is a good technique for growing non congruently melting crystals (CBF) and crystals originating from a solid solution (KLN). The obtained single crystal fibres were transparent, homogeneous in composition and had a good crystalline quality. The study of the growth of KLN fibers showed that it is very difficult to obtain crystals oriented along the a axis with the used technique. With regard to CBF, the viscosity of the liquid requires to determine the most appropriate couple pulling rate/capillary diameter to obtain transparent crystals. For BZBO, the yellow-red colour of the obtained fibres is probably a consequence of the presence of another phase richer in bismuth
Etude de la dégradation thermique et de la réaction au feu de nanocomposites à matrice PMMA et PS by Nicolas Cinausero( Book )

in French and held by 1 WorldCat member library worldwide

En dépit de leurs propriétés uniques, les polymères sont très sensibles à la température et sont susceptibles de s'enflammer en présence d'une source de chaleur et au contact de l'air. Afin de remplacer les additifs retardateurs de flammes halogénés, soumis à certaines inquiétudes et restrictions, nous avons étudié de nouveaux systèmes retardateurs de flammes à base d'oxydes minéraux nanométriques concernant deux polymères : le poly(méthacrylate de méthyle) (PMMA) et le polystyrène (PS). Trois stratégies ont été mises en place. Nous avons examiné dans un premier temps l'influence des oxydes d'aluminium et de silicium nanométriques sur les propriétés ignifuges et les mécanismes de stabilité thermique des nanocomposites à matrices thermoplastiques. Divers paramètres ont été évalués comme le taux d'incorporation, la composition chimique des oxydes et le type de matrice polymère. L'impact de la modification de surface des nanoparticules sur la réaction au feu des composites a été également analysé. Les traitements de surface des oxydes concernent des greffages de molécules organiques de faible masse molaire, le dépôt de couches inorganiques et le greffage d'oligomères. Enfin, des combinaisons d'additifs phosphorés et de nanocharges, vierges ou modifiées, ont mis en évidence des synergies notables sur la réaction au feu. L'étude du procédé d'ignifugation des composites a été réalisée notamment par l'analyse approfondie des résidus charbonnés
Dynamique de combustion des végétaux et analyse des fumées émises, effets de l'échelle et du système by Elodie Romagnoli( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

Wildfires are characterized by a lot of scales of time and space. A multi-physics and multi-scale approach is required to consider the complexity of these phenomena. This thesis is an experimental contribution to the study of the scale effects and the effects of the system on the combustion dynamics of forest fuels and smoke emission. The aim of this work was to determine which experimental protocols and specifically which scales can be used to characterize the combustion of vegetal fuels in the laboratory. The reaction to fire of pine needles species representative of the Mediterranean ecosystem, (Pinus pinaster and Pinus laricio) has been studied. Litters of pine needles are an important issue because they sustain fire spread and are involved in the transition from a surface fire to a total fire.Three experimental configurations were studied in this thesis: the cone calorimeter scale; the large scale calorimeter or LSHR (allowing static combustion with larger masses than used with the cone); a fire spread in the LSHR, allowing to study the effect of the system on the dynamics of combustion and release of smoke. To compare these configurations, experimental protocols have been elaborated while keeping the same fuel load. Different parameters were studied to analyze the combustion dynamics such as combustion efficiency, heat released rate and mass loss rate. Smoke production was studied by measuring the coefficient of extinction to characterize their opacity and an estimation of the soot emission factor was derived. The emission factors of the main compounds emitted during the combustion of these two pines needles were measured with a Fourier Transform Infrared analyzer and a Non-dispersive infrared analyzer. Analysis by gas chromatography coupled with a flame ionization detector and a mass spectrometer allowed us to complete these measurements. A mass balance of carbon was also performed to quantify the total carbon measured through our analyzes.The main contributions of our work can be summarized as follow: the study of the burning of Pinus pinaster needles reveals significant differences for heat release rate (HRR) at both cone calorimeter and LSHR scales. However, the combustion system (fire spread) does not influence the HRR value at the LSHR scale. The combustion efficiency appeared to be independent with regard to the scale and the system. We observed a wide influence on the rate of smoke release and the emission factor of soot. We also shown that the combustion system (fire spread) influences the dynamics and value of emissions factors of carbon dioxide and carbon monoxide (major compound emitted for these combustions). An influence of the three experimental configurations on the emission factors of nitrogen compounds and VOC emissions was also noted. This difference was attributed to the level of smoke temperature. Finally, an effect of particles geometry was also pointed out by the comparison between the burnings performed with the cone calorimeter and the LSHR for both types of pine needles. The combustion dynamics of Pinus laricio needles was slighlty affected by changing scale in comparison to needles of Pinus pinaster (weak variation of HRR). We also observed that Pinus laricio's needles, which are thermally thiner than Pinus pinaster ones have the lowest soot emission factor
Nouveaux concepts d'élaboration de la pyrazolidine par la méthode Raschig et par voie indirecte, en transitant par la 1 et 2-pyrazoline, suivie d'une hydrogénation catalytique : synthèses et modélisations cinétiques, équilibres entre phases et schémas de procédés by Ahmad El Hajj( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

Ce travail, effectué dans le cadre d'une convention de recherche avec la Société ISOCHEM, a pour objectif la mise au point d'un nouveau procédé de synthèse de la pyrazolidine par la voie Raschig directe et par voie indirecte, en transitant par la 1 et 2-pyrazoline, suivie d'une hydrogénation catalytique. Cette hydrazine suscite un grand intérêt en raison de ses nombreuses applications dans l'industrie pharmaceutique et des cosmétiques. Cette thèse a été financée par le Centre National de Recherche Scientifique dans le cadre d'une bourse doctorale ingénieure/PED. La première partie est consacrée à l'étude du procédé Raschig direct qui résulte de l'action de l'hypochlorite de sodium sur un excès d'amine. La définition du process a nécessité la détermination des cinétiques et des mécanismes réactionnels afin de déterminer les rendements, les temps de séjour et de simuler numériquement l'ensemble des opérations de synthèse. Les conditions d'extraction ont été établies en exploitant les particularismes des équilibres entre phases impliqués afin d'élaborer le flow-sheet correspondant. La seconde partie est relative à la voie indirecte. Elle est basée sur l'élaboration de la 1- pyrazoline par une double déshydrohalogénation du N,N-dichloro-1,3 diaminopropane. La pyrazolidine est ensuite obtenue par hydrogénation catalytique du groupe azo. Un modèle global d'élaboration de la pyrazolidine a été établi qui nous a permis de déterminer les conditions optimales et de définir les segments synthèses et extractions ainsi que les différentes opérations unitaires du procédé ainsi que les bilans matière et énergie
Synthèse et caractérisation de polymères méthacryliques phosphorés à propriétés retardatrices de flamme by Anne Gentilhomme( )

1 edition published in 2003 in French and held by 1 WorldCat member library worldwide

Le Polyméthacrylate de méthyle PMMA trouve de nombreuses applications dans différents domaines de l'industrie, mais cependant il est facilement inflammable. Son ignifugation représente donc un enjeu commercial important. Une méthode classique consiste à ajouter l'ignifugeant au polymère mais souvent au détriment du comportement mécanique du matériau. Pour pallier ceci, nous avons donc fonctionnalisé ces polymères par des molécules phosphorés. Après leur caractérisation, l'étude de leur dégradation thermique, de leur comportement au feu, ainsi que celle des gaz émis lors de leur combustion et de leurs résidus, nous avons montré que ces nouveaux polymères avaient ds propriétés retardatrices de flamme meilleures que celles du PMMA. Cette voie est prometteuse mais nécessite d'être combiner avec des méthodes d'additivation afin d'améliorer leur comportement au feu et de réduire la libération de CO et de fumées
Polyméthacrylate de méthyle (PMMA) Développement de nouveaux systèmes retardateurs de flamme à base de nanocharges minérales. Recherche de synergies avec des montmorillonites et des composés phosphorés by Abdelghani Laachachi( )

1 edition published in 2005 in French and held by 1 WorldCat member library worldwide

The poly(methyl methacrylate) (PMMA) is a very interesting thermoplastic polymer. It finds many applications in many sectors and particularly in the field of lighting (lamps, signs...). However, like many polymers, it is easily flammable and its fireproofing is an important commercial stake, especially as the norms in the matter are more and more stricts (halogen-free compounds). Among the methods of improvement of the fire resistance of polymers, one of the most used consists in incorporating in the polymeric matrix particles of inorganic compounds. Among those, clays of the montmorillonite type are particularly promising by ensuring the construction of a silicato-carbonized layer at the surface of the polymer during its combustion. Nevertheless, the majority of the performed studies show the need for using these lamellar particles in combination with other flame retardant additives in order to obtain a flame behaviour fully meeting the norms in use. Among these additives, are the metallic oxide nanoparticles. The principal objective of this work was the study of the effect of some metal oxides or hydroxides, with different features (size and specific surface area), on the thermal stability and fire resistance of PMMA. Then, synergies were investigated between the oxides considered as the most interesting (particularly, the nanometric ones) and an organo-modified montmorillonite (OMMT) or with various commercial phosphorated flame retardant additives
Nouvelle stratégie d'élaboration de la monométhylhydrazine via le procédé Raschig en utilisant la technologie des microréacteurs : synthèse de la chloramine dans des conditions quasi-stoechiométriques et isolement en une seule étape multifonctionnelle by Duc Minh Le( )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

This work, conducted as part of a collaboration with the Safran-Heraklès group, aims at developing a new synthesis concept for the monomethylhydrazine (MMH), by process intensification using microreactor technology. The work was funded by the Rhône-Alpes region in the form of a doctoral fellowship TARGET 2008-2011. The first part of this research aims to study the stability of monochloramine solutions prepared in stoichiometric conditions. This synthesis was carried out continuously, for the first time ever, using microreactor technology. Optimal synthesis conditions as well as a set of security parameters have been established for a fast and secured transfer to industrial scale. The second part, also one of the main objectives of this work, is the extraction, under pressure, of all organic products (mostly MMH and monomethylamine) in the form of one condensed phase by demixing the crude reaction liquors. This phenomenon is related to the existence of a miscibility gap in the liquid ternary system H2O-MMA-NaOH. The optimization of the demixing step requires then the study of different solid-liquid-liquid phase diagrams involved. The last part deals with the chemical engineering aspect of the research. A kinetic modeling of the synthesis of MMH by the Raschig way was used in order to estimate the composition of the synthesis solution. These results and the application of phase diagrams allow the determination of optimal conditions for the isolation step and the establishment of process flow-sheets for the synthesis of MMH
Contribution à l'étude des équilibres liquide - solide du système quaternaire réciproque H⁺, NH⁺₄, SO²₄⁻, NH₂ SO₃⁻, H₂O by M Ferriol( Book )

1 edition published in 1977 in French and held by 1 WorldCat member library worldwide

ETUDE PAR DOSAGES CHIMIQUES ET CONDUCTIMETRIE. SYSTEMES TERNAIRE ET QUATERNAIRE. HYDROLYSE DE L'ACIDE SULFAMIQUE
Élaboration et caractérisation de fibres cristallines de nouveaux matériaux pour la conversion de fréquence dans le domaine V-UV par la technique micro-pulling down by Farah Assi( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

The growing interest in compact all-solid state laser sources based on non-linear optical crystals emitting in the UV range is explained by their numerous applications such as photolithography, marking, micromachining, cutting or surgery. The only way to generate an ultraviolet laser light from an oxide crystal is by frequency conversion of a near-infrared source. In these conditions, the research works focus towards borate crystals due to their performance, transparency and resistance to laser damage. In this context, we have studied three borate materials: Bi2ZnB2O7 (BZBO), LaBGeO5 (LBGO) and BaCaBO3F (BCBF). Several BZBO crystal fibers were pulled under different conditions by micro-pulling down technique, in order to solve the problem of the orange-red color of the obtained fibers in previous works. The direct growth of LBGO fibers from the melt is impossible because of its excessive viscosity. It was then necessary to find a flux to reduce viscosity and provide crystals with good quality and usable dimensions. So, the LBGO-LiF phase diagram was studied and also the isoplethal section La2O3- LaBGeO5 in the La2O3-B2O3-GeO2 ternary system to examine the possibility of "self-flux". The growth of BCBF fiber being very difficult, the micro-pulling down technique is not appropriate, in its present version, for the growth of this material
Stabilité des solutions aqueuses de borohydrure de sodium lors de la génération d'hydrogène par hydrolyse by Tatiana Vilarinho Franco( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

Numerous investigations are addressing both component optimization and development of miniature energy sources. The rise of portable eletronic devices, brings to the fore the crucial issues of power supply. The foresceable evolution in functionalities and utilizations, as regards portable eletronic devices, together with the introduction of novel electronic components, entail considerable changes in requirements, in terms of power consumption and autonomy. Hydrogen generation by means of the hydrolysis of borohydrides is a promising technology for portable fuel cells. Particularly, sodium borohydride (NaBH4) presents many advantages for that purpose. For example, NaBH4 solutions are non-flammable thus yielding safe processes; the rate of H2 generation is easily controlled by a catalyst; reaction products are environmentally benign and finally the reaction by-product can be recycled. The hydrolysis of NaBH4 in water to produce H2 gives by-products, NaBO2.yH2O, hydrated sodium borate according to MBH4 + (2+x) H2O → 4 H2 + MBO2.xH2O The interesting point of this work is to increase the amount of produced H2 in order to improve the energy density of the H2 generator system. For this, one of the main challenges is to increase the NaBH4 concentration of the cartridge solution thus avoiding the drawbacks induced by NaBO2 crystallization, but also to control the stabillity of this solution, it means add sodium hydroxyde to limit the NaBH4 self-decomposition, thus stabilizing the system. This work shows the two aspects of the analysis of the cartridge timelife : - The kinetic of spontaneous hydrolysis of alkaline aqueous NaBH4 solutions as function of NaOH concentration and the operation temperature range of the cartridge, - An unequivocal understanding of the NaBO2 crystallization process and more specifically the delimitation of the homogeneous liquid phase domain in the quaternary system NaBH4- NaBO2-NaOH-H2O, which represents the mixture present during the hydrogen cartridge operation
Nouvelle stratégie d'extraction et de purification de l'hydrazine N2H4 de grade spatial via le procédé Raschig : synthèse, modélisations cinétiques, équilibres entre phases et schémas de procédé by Clélia Betton( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

This work, funded by the CIBLE-Rhône-Alpes Region, in partnership with the HERAKLES-SAFRAN group, aims to develop a new method for extracting and purifying hydrazine N2H4, for space applications. This monopropellant must be of very high purity, with an upper mass composition of 99.5% hydrazine and a carbon content of less than 30 ppm.The first part of this study allowed us to identify the reactions of formation and degradation to establish a global kinetic model and determine the guiding parameters of synthesis. Knowledge of the compositions of reaction liquors function of operating conditions of the synthesis, has allowed us to position, on leaving the reactor, the overall mixing point in the diagrams of ternary and quaternary phases in order to define the optimum extraction conditions.The second part concerns the detailed thermodynamic study of the new method of extraction, which is, not to extract excess ammonia from the reaction mixture but maintain the in situ to extract the hydrazine in the liquid phase separation -liquid by solvent effect. The aim ultimately is to get a virtually anhydrous ammonia phase so as to eliminate multiple distillations and complex extraction and purification encountered in the traditional process. This new strategy is based on the existence of a miscibility gap in the liquid state, in the H2O-NH3-H2O-NaOH ternary system and N2H4-NH3-NaOH quaternary system at a pressure of between 15 and 20 bar.The last part deals with the process engineering component. The operation of kinetic model and phase diagrams involved allowed us to determine the optimum conditions of synthesis and isolation, to calculate the composition of the material flow at the end of each unit operation and compare them with previous industrial processes . The process diagrams for each option have been prepared and analyzed at cost, safety and specifications obtained useful product
 
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Alternative Names
Ferriol, Michel

Languages
French (26)

English (5)