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Letteratura scientifica selezionata sul tema "Calcium aluminosilicate"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 12 febbraio 2022

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Articoli di riviste sul tema "Calcium aluminosilicate"

Loganina, Valentina Ivanovna, Ludmila V. Makarova, Roman V. Tarasov, and Anton D. Ryzhov. "The Limy Composite Binder with the Use of the Synthesized Aluminosilicates." Applied Mechanics and Materials 662 (October 2014): 11–14. http://dx.doi.org/10.4028/www.scientific.net/amm.662.11.

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The information about the structure and properties of the synthesized nanodisperse additive based on the aluminosilicates of calcium, intended for the production of limy dry construction mixes are provided. It is shown that the mineral composition of an additive is presented by crystal types of hydroxides of aluminum (bayerite and boyhmite) and the nanostructured amorphous aluminosilicate of calcium. It is established that the additive based on the aluminosilicates accelerates the process of hardening of limy compositions.

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Walkley, Brant, Rackel San Nicolas, Marc-Antoine Sani, John D. Gehman, Jannie S. J. van Deventer, and John L. Provis. "Synthesis of stoichiometrically controlled reactive aluminosilicate and calcium-aluminosilicate powders." Powder Technology 297 (September 2016): 17–33. http://dx.doi.org/10.1016/j.powtec.2016.04.006.

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Jiang, Fengrui, Laifei Cheng, Yiguang Wang, and Xuanxuan Huang. "Calcium–magnesium aluminosilicate corrosion of barium–strontium aluminosilicates with different strontium content." Ceramics International 43, no. 1 (January 2017): 212–21. http://dx.doi.org/10.1016/j.ceramint.2016.09.138.

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Snellings, Ruben. "Surface Chemistry of Calcium Aluminosilicate Glasses." Journal of the American Ceramic Society 98, no. 1 (October 4, 2014): 303–14. http://dx.doi.org/10.1111/jace.13263.

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Higby, P. L., Lynda E. Busse, and Ishwar D. Aggarwal. "Properties of Low-Silica Calcium Aluminosilicate Glasses." Materials Science Forum 67-68 (January 1991): 155–60. http://dx.doi.org/10.4028/www.scientific.net/msf.67-68.155.

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SHELBY, J. E. "Formation and Properties of Calcium Aluminosilicate Glasses." Journal of the American Ceramic Society 68, no. 3 (March 1985): 155–58. http://dx.doi.org/10.1111/j.1151-2916.1985.tb09656.x.

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Chervonnyi, A. D., and N. A. Chervonnaya. "Synthetic calcium aluminosilicate monolith: IV. Mechanical properties." Russian Journal of Inorganic Chemistry 55, no. 10 (October 2010): 1529–35. http://dx.doi.org/10.1134/s0036023610100062.

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Agnello, Gabriel, Robert Manley, Nicholas Smith, William LaCourse, and Alastair Cormack. "Triboelectric properties of calcium aluminosilicate glass surfaces." International Journal of Applied Glass Science 9, no. 1 (May 22, 2017): 3–15. http://dx.doi.org/10.1111/ijag.12276.

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Hwa, Luu-Gen. "Rayleigh-Brillouin scattering in calcium aluminosilicate glasses." Journal of Raman Spectroscopy 29, no. 4 (April 1998): 269–72. http://dx.doi.org/10.1002/(sici)1097-4555(199804)29:4<269::aid-jrs234>3.0.co;2-2.

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Derrien, A. C., H. Oudadesse, J. C. Sangleboeuf, P. Briard, and A. Lucas-Girot. "Thermal behaviour of composites aluminosilicate-calcium phosphates." Journal of Thermal Analysis and Calorimetry 75, no. 3 (2004): 937–46. http://dx.doi.org/10.1023/b:jtan.0000027187.14921.86.

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Più fonti

Tesi sul tema "Calcium aluminosilicate"

Zhang, Siqi. "The effect of boron substitution on the structure of calcium-aluminosilicate calcium-fluoro-aluminosilicate glasses and glass-ceramics." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7173/.

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This work focuses on the effect of boron substitution for aluminium on the structure o£ a series of fluorine-free (4.5Si02-3A12O3-1.5P205-5Ca0) and fluorine-containing (4.5Si02-3A1203-1.5P205-3Ca0-2CaF2) glasses and the resultant glass ceramics has been studied by using a combination of analytical tools like helium pycnometer, FTIR, Raman, XRD, multinuclear MAS-NMR spectroscopy and thermal analysis by DSC and TGA. The morphology of the crystal phases was observed by ESEM, and the identification of the composition observed was achieved by EDX. The density of both boron-substituted aluminium glasses and glass ceramics decreased with increasing boron content. The glass transition temperature decreased generally with an increase of boron substitution in fluorine-free glasses. When the sintering temperature was raised to 1100°C, the calcium phosphate (C'4P20 9) phase transferred to the tricalcium phosphate [Ca3(P04)2] phase, and anorthite and aluminium phosphorus phases were crystallised. The fluorapatite phase was the first phase to be formed in the fluorine-containing glass ceramics, and with the sintering temperature raised to 1100°C, the mullite and aluminium phosphorus phases were crystallised. All the NMR results investigate the structure of boron-substituted glasses and glass-ceramics which are agree with XRD results. ESEM and EDX analysis showed changes in the composition of glass ceramics with boron substitution.

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Oppici, Maria A. "Sodium sulfate hot corrosion of silicon carbide fiber-reinforced calcium aluminosilicate." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA297663.

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Bouchouicha, Hamed. "Élaboration, caractérisation structurale et étude des propriétés de luminescence des verres et des vitrocéramiques alumino-silicatés de calcium dopés à l'europium." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1035/document.

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Ce travail de thèse porte sur l'étude des verres alumino-silicatés de calcium dopés à l'europium et le processus de leur cristallisation sous forme des vitrocéramiques dans le cadre de la recherche de nouveaux phosphores pour application LED à émission blanche. Nous avons étudié trois échantillons vitreux avec différentes teneurs en silice et avons élaboré des vitrocéramiques cristallisées. La caractérisation des verres et des vitrocéramiques a été réalisée par différentes techniques expérimentales : l'analyse thermique, la diffraction des rayons X et la spectroscopie de diffusion Raman. Les propriétés spectroscopiques de l'ion europium dans les verres et les vitrocéramiques synthétisés ont été étudiées. Le contrôle de la cristallisation des vitrocéramiques GC34 et GC50 par la diffraction des rayons X a permis d'identifier deux phases la mélilite et l'anorthite. Dans le cas de la vitrocéramique GC7, une seule phase alumino-calcique qui est la mayenite est cristallisée majoritairement. L'étude par la spectroscopie de diffusion Raman a permis d'une part, de suivre l'évolution de la cristallisation pendant les traitements thermiques en surface et en profondeur dans l'ensemble des vitrocéramiques. Nous avons montré que le processus de cristallisation a eu lieu en surface des échantillons et correspond typiquement à une nucléation hétérogène. D'autre part, une étude comparative avec des échantillons naturels analogues prise de la base de données RRUFF nous a permis de valider l'ensemble des résultats trouvés. Dans le cas des vitrocéramiques GC34 et GC50, les mesures des spectres d'émission et les durées de vie de l'ion Eu3+ montrent bien son incorporation dans les phases cristallines formées. L'ion Eu3+ tend à occuper seulement les sites Ca2+ (CN= 8) de la mélilite majoritaire dans la vitrocéramique GC34 alors, qu'il tend à s'incorporer dans les sites Ca2+ (CN= 6 et 7) et Ca2+ (CN=8) respectivement, des phases anorthite et mélilite formées dans la vitrocéramique GC50. Ces résultats ont été confirmés par les mesures d'affinement de raies. L'étude des spectres d'émission de l'ion Eu2+ a permis de mettre en évidence une modification de son environnement durant la cristallisation traduite par son incorporation dans les sites Ca2+ après réduction de l'ion Eu3+ pendant les recuits. Dans le cas de la vitrocéramique GC7, les spectres d'émissions et les mesures du déclin de luminescence de l'ion Eu3+ montrent bien que l'ion Eu3+ est incorporé dans la phase mayenite formée. En terme d'application, les mesures des coordonnées trichromatiques suggèrent que la dévitrification des verres semble être une technique efficace permettant d'obtenir de nouveaux matériaux luminophores (LED blanches) à émission intensifiée (cas des vitrocéramiques GC34 et G50) et accordable en modifiant leur composition et l'excitation This work concerns the study of calcium aluminosilicate glass doped with europium and their process of crystallization as glass-ceramics as part of the search for new phosphors for white LED application. We studied three glass samples with different silica contents and have elaborated crystallized glass-ceramics. Characterization of glasses and glass-ceramics was performed by different experimental techniques: thermal analysis, X-ray diffraction and Raman spectroscopy. The spectroscopic properties of the europium ion in the glass and glass-ceramic synthesized were studied.Control of crystallization of GC34 and GC50 glass-ceramics by X-ray diffraction have been identified two phases, melilite and anorthite. In the case of the GC7 glass-ceramic, a single aluminum calcium phase, mayenite which crystallized predominantly. The study by Raman spectroscopy allowed to follow the evolution of the crystallization during heat treatment in the surface and of glass-ceramics. We have shown that the crystallization process initiate at the surface of the samples and corresponds typically to a heterogeneous nucleation. On the other hand, a comparison with similar natural samples allowed us to validate all the identifications.In the case of GC34 and GC50 glass-ceramics, emission spectra and lifetimes of Eu3+ ion clearly show its incorporation into the new-formed crystalline phases. The Eu3+ ion occupy the Ca2+ sites (CN = 8) in the major mélilite phase of the the GC34 glass-ceramic while, it incorporates the Ca2+ sites (CN = 6 and 7) and Ca2+ (CN = 8) of anorthite and mélilite phases formed in the GC50 glass-ceramic, respectively. These results were confirmed by Fluorescence Line Narrowing (FLN) measurements. The study of emission spectra of the Eu2+ ion allowed highlighting changes during crystallization associated with the reduction of the Eu3+ ions during annealing. In the case of the low silicate GC7 glass-ceramic, emission spectra and lifetimes measurements of the Eu3+ ion show that the Eu3+ ions are incorporated into the mayenite phase. In terms of application, the analyses of the trichromatic coordinates suggest that the glass devitrification appears to be an efficient technique to achieve new white LED phosphor materials with intensified (mainly for GC34 and G50 glass-ceramics) and tunable emission by varying composition and/or excitation

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Newton, Peter J. "Sodium sulfate corrosion of silicon carbide fiber-reinforced calcium aluminosilicate glass-ceramic matrix composites." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA283703.

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Bouhadja, Mohammed. "Modélisation des verres d 'aluminosilmicates de calcium par dynamique moléculaire : Structure et dynamique." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00961955.

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Ce travail a pour but d'étudier les propriétés structurales et dynamiques des verres aluminosilicate de calcium CaO-Al2O3-SiO2 (CAS) par dynamique moléculaire classique, à partir d'un potentiel empirique de type Born-Mayer-Huggins, construit sur la base de résultats de dynamique moléculaire ab initio (AIMD) et expérimentaux. Il montre de bonnes propriétés de transférabilité sur toutes les concentrations pour les propriétés structurales et dynamiques étudiées. L'évolution des propriétés structurales a été étudiée en fonction de la température et de la concentration en silice pour trois rapports de concentrations R = [CaO]/[Al2O3]= 1, 1.57 et 3. Les résultats révèlent la présence d'oxygènes non-pontants et tricoordonnés et d'aluminium penta-coordonnés pour toutes les concentrations dont le nombre diminue avec l'augmentation avec la concentration en silice. L'étude de la viscosité et du temps de relaxation structural avec la température a permis de montrer que la fragilité diminue avec l'augmentation de la concentration en silice pour les trois valeurs de R. Une corrélation avec l'évolution des oxygènes non pontant indique que ces derniers jouent un rôle prépondérant pour la fragilité. Il est montré que la théorie des couplages de modes s'applique à la dynamique des CAS et qu'une violation de la relation de Stokes-Einstein se produit au-dessus du point de fusion expérimental indiquant une hétérogénéité dynamique.

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Lambert, Julien. "Etude structurale d’aluminosilicates de calcium : application à la valorisation de déchets amiantés pour le stockage thermique d’énergie solaire." Thesis, Orléans, 2013. http://www.theses.fr/2013ORLE2012.

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L’objectif de ce travail de thèse est d’établir les relations entre les propriétés structurales et les conditions d’élaboration d’un vitrifiat de déchets amiantés (nom commercial Cofalit®), dans la perspective de fabriquer un prototype de module de stockage thermique d’énergie solaire. Malgré des provenances de déchets très diverses, les variations de compositions du vitrifiat restent limitées. Les conditions d’élaboration (de refroidissement en particulier) induisent par contre d’importantes disparités dans la microstructure. L’analyse d’une carotte de Cofalit nous a permis de déterminer les mécanismes de cristallisation lors de la fabrication du Cofalit (refroidissement non contrôlé), conduisant à un mélange de phases cristallisées et vitreuse. Nous avons étudié les propriétés structurales (par DRX et RMN) et de cristallisation d’échantillons modèles représentatifs du matériau industriel. Les variations de composition observées sur celui-ci ont été simulées par des ajouts de silice ou de chaux. L’influence de la teneur en fer sur les propriétés radiatives, structurales (verres et céramiques) et de cristallisation a également été quantifiée. Le suivi de la cristallisation séquentielle des céramiques a été effectué par DRX in situ à haute température, à partir de l’état vitreux et à partir de l’état liquide lors du refroidissement. Ces essais ont montré que le Cofalit cristallise complètement pour des vitesses de refroidissement inférieures à 10 K/min. La stabilité du Cofalit (au niveau structural) lors de recuits à hautes températures a également été démontrée The aim of this work is to establish relationships between structural properties and production conditions of a vitrified asbestos-containing wastes ceramics (commercially named Cofalit®), with the goal of elaborating a prototype for thermal energy storage of solar energy. Despite various waste sources, the variations of composition observed for this material are limited. On the contrary, the production conditions (cooling stage in particular) induce important differences in the material microstructure. The analysis of a Cofalit core sample allowed us to determine the crystallisation mechanisms during its fabrication process (uncontrolled cooling), leading to a mixture of vitreous and crystalline phases. We propose a structural study (by XRD and NMR) and crystallization properties analyses of synthetic samples, representative of the industrial material. Observed variations of composition on the latter are simulated by additions of silica and lime. The influence of iron oxide content on radiative, structural and crystallization properties (of both glass and ceramic samples) have also been investigated. The following of the sequential crystallisation of ceramic samples has finally been performed using in situ high temperature XRD, from glassy state and during cooling from liquid state. These tests show that the Cofalit crystallizes completely for rates lower than 10 K/min. The high temperature stability on a structural level has also been demonstrated during annealings

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Terra, Idelma Aparecida Alves. "Investigação espectroscópica e estudo dos processos de conversão de energia em vidros e nano-cristais co-dopados com íons Tb3+ e Yb3+." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-26082013-172114/.

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A busca por alternativas viáveis de produção de energia limpa e renovável, utilizando recursos naturais, tem sido um grande desafio. Em especial, o interesse no uso da energia solar para obter energia elétrica tem aumentado. Todavia, as células solares convencionais que são confeccionadas a partir de silício cristalino (Si-c) apresentam uma eficiência de conversão limitada, principalmente, devido às perdas por incompatibilidade espectral. Sendo assim, um dos objetivos dos pesquisadores na área de fotovoltaicos tem sido converter eficientemente fótons da região do visível do espectro solar para a região do infravermelho, onde a célula solar de Si-c possui maior eficiência. A eficiência desta conversão poderia ser melhorada de 28% até 40% usando conversores de energia compostos por íons terras raras. Neste trabalho foram estudadas as propriedades espectroscópicas dos íons terras raras Térbio (Tb3+) e Itérbio (Yb3+), embebidos em três diferentes materiais: vidro aluminosilicato de cálcio com baixa concentração de sílica (7%) (LSCAS), vidro tetraborato de cálcio-lítio (Calibo) e nano-cristais de óxido de zircônia (ZrO2). Sendo assim, nossos estudos visam elucidar os mecanismos geradores dos processos de conversão ascendente e descendente de energia. No processo de conversão ascendente de energia há conversão dos fótons de excitação de baixa energia na região do infravermelho em fótons de alta energia na região do visível. Por outro lado, no processo de conversão descendente de energia ocorre a conversão dos fótons de excitação de alta energia na região do ultravioleta/visível em um ou mais fótons de baixa energia na região do infravermelho. As propriedades espectroscópicas dos materiais estudados foram discutidas a partir das medidas de absorção, luminescência, excitação, evolução temporal da luminescência, curva de potência, difração de raios-X, X-Ray Absorption Near Edge Structure e ressonância paramagnética eletrônica, em função da concentração dos íons Tb3+ e Yb3+. Os resultados mostraram que todas as amostras apresentam conversão ascendente de energia. Assim como, em todas as amostras ocorre o processo de conversão descendente de energia. Em ambos os processos foram identificados os mecanismos geradores dos mesmos. Estes resultados mostram um avanço nos estudos dos processos de conversão ascendente e descendente de energia em sistemas co-dopados com íons Tb3+ e Yb3+. Os resultados sugerem que os materiais estudados podem ser empregados para aumentar a eficiência de conversão da célula solar de Si-c via conversão descendente de energia. The search for possible alternatives to produce clean and renewable energy using the natural resources has been a great challenge. In particular, the interest to use the solar energy to produce electricity has been increased. However, crystalline silicon-based (c-Si) conventional solar cells have limited conversion efficiency, mainly due to spectral mismatch losses. Thus, one of the goals of some researchers in the photovoltaic field has been to efficiently convert photons in the visible region of the solar spectrum to the infrared region, where the c-Si solar cell has its higher efficiency. The efficiency of this conversion could be enhanced from 28% up to 40% using energy converters based on rare-earths ions. In this work, the spectroscopic properties of rare earth ions, such as Terbium (Tb3+) and Ytterbium (Yb3+) embedded in three different materials were studied: low- silica calcium aluminosilicate glass (7%) (LSCAS), lithium calcium tetraborate glass (Calibo) and zirconium oxide nano-crystals (ZrO2). Thus, our studies aimed to elucidate the mechanisms that generate the Up-conversion and Down-conversion processes. In the Up-conversion process, there is the conversion of the low-energy excitation photons in the near-infrared to high-energy photons in the visible. On the other hand, in the Down-conversion process there is the conversion of the high-energy excitation photons in the ultraviolet/visible region to low-energy photons in the near-infrared region. The optical properties of the studied materials were discussed through absorption, luminescence, excitation, temporal evolution of the luminescence, power curve, X-ray diffraction, X-Ray Absorption Near Edge Structure and electron paramagnetic resonance measurements, as a function of the concentration of Tb3+ and Yb3+ ions. The results showed that all samples exhibit Up-conversion process. In addition, in all samples occurs the Down-conversion process. In both processes were identified the mechanisms that produce them. These results show a breakthrough in the studies of the Up-conversion and Down-conversion processes in Tb3+ and Yb3+ co-doped systems. The results suggest that the materials are applicable in enhancing the conversion efficiency of the Si-c solar cell via NIR Down-conversion.

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Kozaily, Jad. "Structure et dynamique d'aluminosilicates de calcium fondus." Phd thesis, Université d'Orléans, 2012. http://tel.archives-ouvertes.fr/tel-00717373.

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L'étude des silicates fondus présente un intérêt dans divers domaines de recherche comme la géologie ou la fabrication des verres avec des applications technologiques importantes telles que par exemple, le confinement des déchets nucléaires. Ces recherches demandent des informations fondamentales sur la structure et la dynamique de ces liquides au niveau microscopique mais l'acquisition des données est très souvent limitée par les températures de fusion élevées des composés étudiés. Notre travail s'est donc basé sur l'utilisation de techniques sans contact afin de s'affranchir de cette difficulté. Dans le cadre de cette thèse, nous nous sommes intéressés à l'étude des propriétés structurales et dynamiques de divers aluminosilicates de calcium (CAS) fondus. Pour cela, nous avons développé un dispositif utilisant la lévitation aérodynamique afin d'effectuer des expériences de diffusion quasi-élastique des neutrons. En combinant ces mesures avec la diffusion inélastique des rayons X, nous avons pu obtenir des résultats sur la dynamique microscopique des CAS à l'état liquide ainsi que dans le régime de surfusion. En particulier, nous avons pu déterminer l'évolution de la viscosité avec la température et les coefficients de diffusion cohérents. Nous avons pu aussi étudier l'évolution de la dynamique de ces verres en fonction de l'augmentation de la quantité de silice dans la composition. En parallèle de nos travaux sur la dynamique, nous avons aussi réalisé des expériences de diffraction de neutrons et de rayons X sur les mêmes compositions et températures afin d'examiner l'ordre atomique local et essayer de le corréler aux propriétés dynamiques observées.

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GANSTER, Patrick. "Modélisation de verres intervenant dans le conditionnement des déchets radioactifs par dynamiques moléculaires classique et ab initio." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2004. http://tel.archives-ouvertes.fr/tel-00007894.

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Un verre de composition 67 % SiO_2 - 12 % Al_2O_3 - 21 % CaO, choisi comme modèle simplifié des pellicules d'altération, est modélisé par les méthodes de dynamique moléculaire (DM) classique et ab initio. L'étude des effets de taille, en DM classique, montre que les systèmes de 100 atomes présentent un caractère plus ordonné par rapport à des systèmes de plus grande taille. L'effet observé est principalement lié à l'utilisation de termes de potentiels 3-corps. Non observable sur les facteurs de structure neutronique, le facteur calculé à partir d'une structure modélisée est en bonne adéquation avec une mesure expérimentale et valide le modèle classique. Les structures modélisées présentent un excès d'atomes d'oxygènes non pontants qui peuvent être compensés par des atomes d'oxygène tricoordonnés. L'exclusion non totale des atomes aluminium est aussi mis en évidence. La poursuite de la dynamique en DM ab initio de systèmes de 100 et 200 atomes fabriqué en DM classique permet d'affiner localement les structures (distances interatomiques, angles). Une description plus réaliste des vibrations est obtenue. La modélisation de films minces en DM classique montre une zone enrichie en calcium en sub-surface où l'on observe une dépolymérisation du réseau vitreux. L'aluminium s'étend le plus en surface et s'y trouve tricoordonné. La distribution atomique des films et les entités AlO_3 sont confirmés par un ajustement en DM ab initio. En DM classique, les atomes d'aluminium produisent un fort champ électrique au dessus de la surface et ils constituent, avec les sites NBO-Ca, des zones réactives avec H_2O.

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Selmani, Samira. "Formulation de liants aluminosilicates à partir de différentes argiles tunisiennes." Thesis, Limoges, 2015. http://www.theses.fr/2015LIMO0041.

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Ce travail est basé sur la synthèse d’un liant aluminosilicaté de type géopolymère à partir de différentes argiles tunisiennes. Afin de comprendre les mécanismes de géopolymérisation, une première étape a concerné la caractérisation des matières premières argileuses par différentes méthodes d’analyses ainsi que leur comportement vis-à-vis du traitement thermique. La faisabilité des matériaux consolidés a été étudiée afin de comprendre le rôle des minéraux associés et la granulométrie de l’argile, en présence d’une solution de référence et de sources aluminosilicatées connues, sur les produits synthétisés. Afin d’identifier le rôle de la solution alcaline, de nouvelles formulations ont été élaborées et comparées aux précédentes en présence des argiles tunisiennes. Plusieurs techniques ont été réalisées pour évaluer les matériaux au cours de leur formation par spectroscopie infrarouge et après consolidation par diffraction des rayons X, microscopie électronique à balayage et analyse thermique. Leurs propriétés mécaniques ont été testées par compression This work is based on the synthesis of geopolymers from different Tunisian clays. In order to understand the geoplymerization mechanisms two steps are established. The first is relate to the characterization of the raw clays materials through different analyzes and their behavior with thermal treatment. The second involve around the study of geopolymers feasibility in order to understand the role of associated minerals and particle size, in the presence of a reference solution and aluminosilicate sources, on the synthesized products. To identify the role of the alkaline solution, new formulations have been developed and compared with previous one in the presence of Tunisian clays. Several techniques are used to characterize the materials during their formation: Infrared Spectroscopy, X ray diffraction, Scanning Electron Microscopy analysis and Thermal analysis. Their mechanical properties were tested by compression

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Più fonti

Libri sul tema "Calcium aluminosilicate"

Newton, Peter J. Sodium sulfate corrosion of silicon carbide fiber-reinforced calcium aluminosilicate glass-ceramic matrix composites. Monterey, Calif: Naval Postgraduate School, 1994.

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Capitoli di libri sul tema "Calcium aluminosilicate"

Goulding, Keith W. T. "Potassium—Calcium Exchange Equilibria in Aluminosilicate Minerals and Soils." In ACS Symposium Series, 327–40. Washington D.C.: American Chemical Society, 1987. http://dx.doi.org/10.1021/bk-1987-0323.ch015.

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Zhang, Lin, Hiroshi Yamada, Yusuke Imai, and Chao Nan Xu. "Development of A Novel Elasticoluminescent Material with Calcium Aluminosilicate." In High-Performance Ceramics V, 352–54. Stafa: Trans Tech Publications Ltd., 2008. http://dx.doi.org/10.4028/0-87849-473-1.352.

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Schofield, J. M., P. A. Bingham, and R. J. Hand. "The Immobilisation of a Chloride Containing Actinide Waste Surrogate in Calcium Aluminosilicate Glasses." In Ceramic Transactions Series, 69–80. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2009. http://dx.doi.org/10.1002/9780470538371.ch8.

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Gharzouni, Ameni, Clément Alizé, and Sylvie Rossignol. "Fire Resistant Geopolymers Based on Several Clays Mixtures." In Clay and Clay Minerals [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98566.

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This chapter aims to highlight the effect of clay mixture mineral composition and alkali concentration of potassium alkaline solutions on the thermal behavior of geopolymer materials. For this, three mixtures composed of kaolin (pure, impure kaolin or mixture of both), calcium carbonate, sand and potassium feldspar and three potassium alkaline silicate solutions with different concentrations were used (5, 6 and 7 mol.L−1). At first, the effect of rotary calcination parameters at 750°C such as the dwell time (30, 60, 120 and 180 min) and weight powder (100, 400 and 500 g) was investigated. It was demonstrated that the kaolin dehydroxylation is quasi complete (> 90%) and do not significantly depend on the dwell time and powder weight. Whereas the carbonate decomposition degree increases with the increase of dwell time and the decrease of powder weight but still not complete (<80%). These differences influence the feasibility of consolidated materials. Indeed, a flash setting occurs for samples based mixtures with high calcium carbonate decomposition degree (> 50%) and low wettability values (500 μL/g) for the three used alkaline solutions. The thermal behavior at 1000°C depends on the chemical composition of the aluminosilicate source and the concentration of alkaline solution. A conservation of the compressive strength at 43 MPa after thermal treatment at 1000°C of geopolymers based on mixture of pure and impure kaolin and a low potassium concentration solution (5 mol.L−1) was evidenced.

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Sato, K., J. Iritani, R. Miyamoto, S. Fujita, K. Suzuki, M. Ohkawa, and T. Mori. "Reactivity of superoxide ions (O2−) occluded in micropores of calcium aluminosilicate varied via substitution with transition metal ions." In Molecular Sieves: From Basic Research to Industrial Applications, Proceedings of the 3rd International Zeolite Symposium (3rd FEZA), 2001–8. Elsevier, 2005. http://dx.doi.org/10.1016/s0167-2991(05)80566-x.

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Shah, Naresh, Gerald P. Huffman, Frank E. Huggins, and Anup Shah. "REACTION OF CALCIUM AND ALKALI ELEMENTS WITH ALUMINOSILICATES AND QUARTZ DURING COAL COMBUSTION." In 1991 International Conference on Coal Science Proceedings, 404–7. Elsevier, 1991. http://dx.doi.org/10.1016/b978-0-7506-0387-4.50103-0.

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Atti di convegni sul tema "Calcium aluminosilicate"

Zhang, Y. Y., Y. H. Qi, and Z. S. Zou. "Early stage hydration properties of calcium aluminosilicate slag." In 2016 6th International Conference on Advanced Design and Manufacturing Engineering (ICADME 2016). Paris, France: Atlantis Press, 2016. http://dx.doi.org/10.2991/icadme-16.2016.6.

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dos Santos, J. F. M., L. A. O. Nunes, N. G. C. Astrath, M. L. Baesso, R. Moncorgé, and T. Catunda. "High-order nonlinearities in Tb3+ doped calcium aluminosilicate glasses." In Advanced Solid State Lasers. Washington, D.C.: OSA, 2015. http://dx.doi.org/10.1364/assl.2015.atu2a.11.

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Borrero-González, L. J., I. A. A. Terra, L. A. O. Nunes, A. N. Medina, and M. L. Baesso. "Spectroscopic Properties and Laser Performance in Yb3+, Er3+ Co-Doped Calcium Aluminosilicate Glasses." In Laser Science. Washington, D.C.: OSA, 2012. http://dx.doi.org/10.1364/ls.2012.lw5i.4.

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Majidi, Azar P., and Tsu-Wei Chou. "Elevated Temperature Studies of Continuous and Discontinuous Fiber Reinforced Ceramic Matrix Composites." In ASME 1989 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1989. http://dx.doi.org/10.1115/89-gt-124.

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This paper reviews the analytical and experimental investigations at the Center for Composite Materials of the University of Delaware on ceramic matrix composites with continuous and discontinuous reinforcements. The focus is on the strength, fracture and creep behaviors of these composites. The experimental studies have been conducted on hot-pressed SiC whisker reinforced alumina and Nicalon SiC fiber reinforced calcium aluminosilicate (CAS) composites.

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Le Losq, Charles, Bjorn O. Mysen, and George D. Cody. "In situ Raman Spectroscopy of Water-Bearing Calcium Aluminosilicate Melts during High Temperature and High Pressure Diamond Cell Experiments." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.1453.

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Faucett, David C., and Sung R. Choi. "Strength Degradation of Oxide/Oxide and SiC/SiC Ceramic Matrix Composites in CMAS and CMAS/Salt Exposures." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-46771.

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CMAS (Calcium-Magnesium-Aluminosilicate) has shown to induce some deleterious effects on yittria-stabilized-zirconia (YSZ) based thermal barrier coatings (TBCs) of hot section components of aeroengines. The effects were shown to be dependent on the types and operating conditions of engines/components. The work presented here explored how CMAS would affect ceramic matrix composites (CMCs) in terms of strength degradation. Four different, gas-turbine grade CMCs were utilized including two types of MI SiC/SiCs and other two types of oxides/oxides (N720/aluminisilicate and N720/alumina). Test specimens in a simple flexure configuration were CMAS-treated at 1200 °C in air under either isothermal or thermal cycling condition. The effects of CMAS were quantified via residual strengths of treated test specimens. Strength degradation with respect to as-received strengths ranged from 10 to 20% depending on the types of CMCs. It was further observed that significant degradation of strength up to 90% occurred in an oxide/oxide CMC when sodium sulfate was added to CMAS.

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Eliel, G. S. N., N. G. C. Astrath, P. T. Udo, L. C. Malarne, M. L. Baesso, T. Catunda, and C. Jacinto. "Spectroscopic properties and heat generation of Yb3+/Ho3+ and Tm3+/Ho3+ co-doped low silica calcium aluminosilicate glasses for emission around 2 µm." In Frontiers in Optics. Washington, D.C.: OSA, 2012. http://dx.doi.org/10.1364/fio.2012.fw3a.18.

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Choi, Sung R., and D. Calvin Faucett. "Combined Effects of CMAS and FOD in Ceramic Matrix Composites." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-70049.

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The combined effects of CMAS (calcium magnesium aluminosilicate) and FOD (foreign object damage) were determined in three different ceramic matrix composites (CMCs), two melt-infiltrated (MI) SiC/SiCs and one oxide/oxide. Foreign object damage was introduced at ambient temperature in CMC test targets using 1.6 mm steel ball projectiles at an impact velocity of 340 m/s utilizing a ballistic impact gun. One type of target support, partial support, was used. The impact-damaged test coupons were then CMAS-exposed at 1200°C for 10 hrs in air. Additional tests were also performed by exposing impact-damaged test coupons to a mixture of CMAS and salt (sodium sulfate) at 1200°C for 10 hrs in air. The combined effects of FOD and CMAS or CMAS/salt were quantified by determining the residual strengths of test coupons after exposures. Also, six different sands ingested into aeroengines were analyzed in their chemical compositions. The melt CMAS solid, melted at 1300°C and solidified, was assessed in its mechanical properties of microhardness and fracture toughness.

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Rudko, Georgii, Mariia Kyrilo, and Maksym Ozerko. "MULTICOMPONENT DEPOSITS WITH BY-PRODUCT AS THE MAIN SOURCE OF FELDSPAR RAW MATERIALS FOR MODERN TECHNOLOGIES." In GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/32.

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"Feldspar is raw materials with a growing volume of production every year, as well as a price for it. Feldspar consumption has been gradually increasing in ceramics, glass industry for solar panels, housing, and building construction. Feldspar raw materials include intrusive, effusive rocks, weathering crust of crystalline rocks, sedimentary altered and altered rocks, as well as partially medium and basic aluminosilicate rocks. It was defined an industrial application for each species of feldspar. Potassium feldspars (orthoclase, microcline, sanidine) are used in electroceramic, electrode, abrasive, and ceramics industries. For these productions, the potash module is fixed in a ratio of 2: 1. For some industries, in particular the manufacture of high-voltage ceramics, the necessary feldspars are as close as possible to pure potassium (with a modulus of at least 4: 1, which corresponds to 80% of the orthoclase component). Potassium-sodium raw materials, from a potassium modulus of at least 0.9, are used for building construction. Sodium minerals with non-standardized potassium modulus are used for the glass industry, the production of enamels, and products such as vitreous porcelain. Calcium feldspars, represented by plagioclase of higher numbers, have limited practical application and their presence in feldspar concentrates is undesirable. According to mineral associations, all types of feldspar raw materials can be divided into five types: 1) feldspar (syenites, trachitis); 2) quartz-feldspar (pegmatites, granites, sands, etc.); 3) nepheline-feldspar (nepheline syenites, alkaline pegmatites); 4) quartz-sericite-feldspar (shales, secondary quartzites); 5) quartz-kaolinite-feldspar (sands, alkaline kaolins, secondary quartzites). It is shown on the example of Ukrainian deposits of feldspar minerals that complex deposits with by-products become the main source for production. Especially if these are new mining operation facilities. The authors have identified three main types of such complex multicomponent deposits: 1) deposits of intrusive rocks where weathering crust of crystalline rocks are mined as a byproduct; 2) complex deposits, where feldspar rocks are enclosing or overburden and can also be considered as byproducts; 3) deposits where feldspar concentrate can be produced as a product of ore components processing."

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Kuleshova, L. A., A. S. Kasakova, and I. S. Tatyanchenko. "INFLUENCE OF PRECURSORS ON THE CONTENT OF MINERAL PHOSPHORUS FRACTIONS IN THE SOILS OF RICE FIELDS IN THE ROSTOV REGION." In STATE AND DEVELOPMENT PROSPECTS OF AGRIBUSINESS Volume 2. DSTU-Print, 2020. http://dx.doi.org/10.23947/interagro.2020.2.704-708.

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The article is devoted to the problem of phosphoric nutrition of rice on chestnut soils of the northernmost zone of rice cultivation in Russia. The paper reveals the role of water-soluble fractions of phosphorus, aluminosilicates, iron phosphates and calcium phosphates in the nutrition of rice plants during the growing season. The influence of the previous culture on the content and consumption of these fractions was established.

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