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Jakobsson, Lars Klemet. "Distribution of boron between silicon and CaO-SiO2, MgO-SiO2,CaO-MgO-SiO2 and CaO-Al2O3-SiO2 slags at 1600°C." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-24010.
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New energy sources are needed for a sustainable future. Solar cells have a huge potential as a sustainable energy source but further development of this technology is needed for solar cells to become cost-competitive with other energy sources. Silicon produced by metallurgical refining methods has the potential of reducing the cost of crystalline silicon solar cells significantly but boron has proven to be hard to remove from silicon by these methods. Slag refining is however a promising refining method for removal of boron from silicon. The aim of this thesis was to determine accurate data for the distribution of boron between silicon and selected slags. All published values of the distribution coefficient of boron have been critically reviewed in this work. The thermodynamic properties and distribution of other major components of the system have also been reviewed. Several experiments with silicon and CaO-SiO2, MgO-SiO2, CaO-MgO-SiO2 and CaO-Al2O3-SiO2 slags have been conducted at 1600 °C under argon atmosphere. A series of experiments with ferrosilicon and CaO-SiO2 slags have also been carried out. Accurate data for the distribution of boron between silicon and CaO-SiO2, MgO-SiO2, CaO-MgO-SiO2 and CaO-Al2O3-SiO2 slags at 1600 °C has been determined. The distribution of other major slag components between slag and silicon has also been found in these slag systems. The distribution of calcium and boron between ferrosilicon and CaO-SiO2 slags at 1600 °C has been determined. Activities of slag forming components have been determined in the CaO-SiO2, MgO-SiO2 and CaO-MgO-SiO2 systems. The activity coefficient of BO1.5 at infinite dilution in these slags has also been determined. Activity coefficients of calcium, magnesium and aluminium at infinite dilution in silicon and the activity coefficient of calcium and boron at infinite dilution in ferrosilicon have been determined. An alternative equation for mass transfer has been derived and the mass transfer coefficient of boron in a 37.9%CaO-62.1%SiO2 slag has been estimated to be ks = 5.2 · 10-7m/s. The refining efficiency of CaO-MgO-SiO2 slags has been found to be approximately the same independently of slag composition with a distribution coefficient of boron between 2 and 2.5. This also includes the binary CaO-SiO2 and MgO-SiO2 systems. The activity coefficient of BO1.5 at infinite dilution in CaO-MgO-SiO2 slags, including the binary CaO-SiO2 and MgO-SiO2 systems, has been found to follow the activity coefficient of SiO2 where . A linear decrease of the distribution coefficient was found with increasing Al2O3 content in a ternary CaO-Al2O3-SiO2 slag. This has been found to be caused by an increasing activity coefficient of BO1.5 at infinite dilution in slag relative to the activity coefficient of SiO2 where<img src="https://innsida.ntnu.no/user/fonn/ansatt/hvaskjer/-/messageservice/channel?p_p_auth=GBC0v8FP&p_p_lifecycle=2&p_p_resource_id=fileSyndView&p_p_cacheability=cacheLevelPage&_readadvancedportlet_WAR_messageserviceportlets_csrfToken=94fa41c2-3215-4437-9f5d-8a6050bffa43&_readadvancedportlet_WAR_messageserviceportlets_messageId=urn%3Auuid%3Abc6ab711-a6b7-3a80-9394-9fbf3c1f5d8f&file=2e0405bc-d564-3f6e-ad46-de0a45593b60" />. The distribution coefficient of boron between ferrosilicon and CaO-SiO2 slags was found to be unchanged with iron content in silicon
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Lira, Claudia. "Obtenção de esmaltes vitrocerâmicos de elevado desempenho nos sistemas MgO-Al2O3-SiO2 e CaO-Al2O3-SiO2." Florianópolis, SC, 2002. http://repositorio.ufsc.br/xmlui/handle/123456789/84173.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência e Engenharia de Materiais.<br>Made available in DSpace on 2012-10-20T06:57:41Z (GMT). No. of bitstreams: 0Bitstream added on 2014-09-26T02:20:11Z : No. of bitstreams: 1
190170.pdf: 33566657 bytes, checksum: c675bd5bf55bac6ed81d265a5a165e9b (MD5)<br>Este trabalho estudou a viabilidade tecnológica de obtenção de esmaltes vitrocerâmicos de elevado desempenho, caracterizando uma alta resistência à abrasão, resistência ao manchamento e ao ataque químico. Inicialmente, procedeu-se à seleção de composições adequadas para a obtenção de fritas. Esta seleção foi realizada a partir de sistemas com cristalização de fases de alta dureza e baixo coeficiente de dilatação térmica, além da facilidade de obtenção e utilização industrial das matérias-primas. Foram investigadas diversas composições nos sistemas MgO-Al2O3-SiO2 e CaO-Al2O3-SiO2, com relação ao seu comportamento térmico de sinterização e cristalização, caracterização microestrutural e dilatométrica. Foram selecionadas duas composições com características mais adequadas à obtenção de esmaltes, segundo os critérios: formação das fases cristalinas cordierita e anortita, baixa porosidade e coeficiente de dilatação térmica adequado aos suportes cerâmicos comerciais. As composições selecionadas para a obtenção de fritas foram: Mg-C2 7% Na2O (composição aproximada: 20%MgO, 24%Al2O3, 49%SiO2, 7%Na2O, % em massa), do sistema MgO-Al2O3-SiO2 e Ca-Z1 do sistema CaO-Al2O3-SiO2 (composição aproximada: 31%CaO, 13%Al2O3, 52%SiO2, 4%ZnO, % em massa). As fritas obtidas a partir das composições selecionadas foram utilizadas na formulação de esmaltes e aplicadas sobre suportes cerâmicos de grês-porcelanato para monoqueima. Para a definição dos parâmetros mais adequados de formulação do esmalte e condições de tratamento térmico foram realizados diversos testes de aplicação, segundo um delineamento experimental pelo método Taguchi. Os esmaltes testados foram avaliados com relação às características visuais, porosidade, medidas de dureza ao risco, dureza Vickers e dureza Mohs. O esmalte obtido a partir da frita Mg-C2 7% Na2O, utilizando queima à temperatura máxima de 1200°C obteve o melhor desempenho na avaliação. Este esmalte apresentou características de elevada dureza ao risco (» 15 GPa), baixa porosidade (» 2%), elevada resistência à abrasão (PEI 5), ao manchamento (classe 5) e ao ataque químico (classe GA e GLA). Estas características se mostraram compatíveis e, em muitos casos, superiores a outros materiais como vitrocerâmicos sinterizados, granito, grês-porcelanato e revestimento para piso classe PEI 5, utilizados como referência. Desta forma, o esmalte vitrocerâmico desenvolvido demonstrou características adequadas a um revestimento cerâmico de alto desempenho, com viabilidade de obtenção segundo os processos convencionais de produção em monoqueima de revestimentos cerâmicos esmaltados.
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Myers, Rupert J. "Thermodynamic modelling of CaO-Al2O3-SiO2-H2O-based cements." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/9175/.
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Most concrete is produced using calcium (alkali) aluminosilicate hydrate (C-(N-)A-S-H)-based cement. However, the chemistry of this phase in many cement-based materials is still not fully understood. This thesis presents a structural and thermodynamic investigation of C-(N-)A-S-H and C-(N-)A-S-H-based cements to provide insight into the chemistry of these materials. A mixed cross-linked and non-cross-linked tobermorite-like structural model for C-(N)-A-S-H is developed (the CSTM), which more appropriately describes the spectroscopic information available for this phase. Application of the CSTM to a Na2SiO3-activated slag cement cured for 56 and 180 days indicates the presence of a poorly-crystalline zeolite-like phase. The role of Al in cross-linking of C-(N-)A-S-H is also studied, which provides a more advanced description of the chemistry and structure of C-(N-)A-S-H than previously reported. A thermodynamic model for C-(N-)A-S-H (CNASH_ss) is derived, which greatly advances the utility of thermodynamic modelling of C-(N-)A-S-H-based cements by explicitly defining Al and alkali uptake in this phase. The chemistry of alkali-activated slag (AAS)-based cements is simulated using CNASH_ss and an ideal solid solution thermodynamic model for MgAl-OH-LDH that is also developed in the thesis. This analysis provides a good description of Na2SiO3-activated slag cement chemistry and accurately predicts chemical shrinkage in this material. Phase diagrams for NaOH, Na2SiO3, Na2Si2O5 and Na2CO3-activated slag-based cements are also simulated. These results can be used to design the chemistry of AAS-based materials. A detailed analysis of C-(N-)A-S-H solubility is presented, for Ca, Al, Si and alkali concentrations most relevant to C-(N-)A-S-H-based cements and at temperatures of 7-80°C. Solubility products for alkali-free C-(N-)A-S-H change slightly between 7°C and 80°C and as a function of Al/Si ratio. However, less soluble C-(N-)A-S-H is formed at higher Ca and alkali content. These results are important for understanding the stability of C-(N-)A-S-H in the majority of cement-based materials used worldwide.
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Haas, Jérémy. "Etude expérimentale et modélisation thermodynamique du système CaO-SiO2-(Al2O3)-H2O." Phd thesis, Université de Bourgogne, 2012. http://tel.archives-ouvertes.fr/tel-00845956.
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L'objectif de ce travail est de proposer un modèle thermodynamique à 25°C qui permette de décrire les principaux produits d'hydratation d'un ciment Portland ordinaire avec et sans matériaux cimentaires secondaires : les hydrosilicates de calcium. La composition riche en aluminium de ces produits de substitution modifie la nature et la composition des hydrates de la pâte de ciment.Nous avons donc étudié le système simplifié CaO-SiO2-H2O, pour lequel nous avons réalisé différentes synthèses de C-S-H dans des conditions de synthèse et d'analyse identiques. Nous avons distingué le cas où la solution d'hydratation est sous-saturée de celui où elle est sursaturée par rapport à la Portlandite.Nous avons ensuite étendu le système simplifié précédent au système CaO-Al2O3-SiO2-H2O, pour lequel nous avons réalisé différentes synthèses de C-A-S-H et déterminé le protocole le plus adéquat pour obtenir des hydrates purs.La nature nanoparticulaire et la surface spécifique importante des C-S-H nous ont conduit à développer un modèle thermodynamique qui tiennent compte de réactions de surface. Ainsi, le modèle thermodynamique proposé dans ce travail, inspiré de différents travaux antérieurs du laboratoire, permet de décrire la composition de la solution, la stoechiométrie, et les propriétés de surface des C-S-H à l'équilibre. Ce premier modèle a été étendu aux C-A-S-H, en implémentant dans le modèle précédent des réactions de surface qui permettent de décrire l'incorporation de l'aluminium dans les différents sites possibles.Ce modèle a été appliqué à des cas simples tels que l'étude de la rétention d'alcalins par les C-S-H, et l'évaluation de l'impact de l'incorporation d'aluminium dans les C-S-H sur la répartition minéralogique des hydrates à l'équilibre pour un mélange cimentaire avec une forte teneur en aluminium
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Gao, Zimin. "Phase Relationships in the System CaO-MgO-Al2O3-SiO2 in Plagioclase Lherzolite Field." FIU Digital Commons, 1991. http://digitalcommons.fiu.edu/etd/3615.
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Unreversed phase equilibrium studies were carried out in a model mantle composition CaO-MgO-Al2O3-SiO2 (CMAS) system at 5-9 kb and 12 7 0-13 3 CPC. The experiments provide a set of data which narrowly constraints the position of the solidus in the system CMAS in the plagioclase lherzolite field. All runs were conducted in a 2.54 cm core-diameter piston-cylinder apparatus with salt-cell pressure medium. The equilibrium compositions of the mineral phases and glass were analyzed with an electron microprobe. The A12O3 contents in orthopyroxene and clinopyroxene coexisting with olivine and plagioclase increase with pressure. The deduced alumina isopleths in orthopyroxene and clinopyroxene have higher slope in P-T space than those of theoretical calculations. An empirical pyroxene geobarometer has been developed and applied to the plagioclase lherzolite xenoliths in Hawaiian basalt.
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Ponton, Clive Brian. "The mechanical properties of glass-ceramics in the system CaO-MgO-Al2O3-SiO2." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/47692.
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Hellmann, Kirsten [Verfasser], Reinhard [Akademischer Betreuer] Conradt, and Yuanzheng [Akademischer Betreuer] Yue. "Anwendungsorientierte Glasentwicklung am Beispiel des Systems CaO-Al2O3-SiO2 / Kirsten Hellmann ; Reinhard Conradt, Yuanzheng Yue." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130327140/34.
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Berg, Martin. "The effect of Al2O3, CaO and SiO2 on the phase relations in vanadium containing slags." Thesis, KTH, Materialvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176079.
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Today, the main raw material for vanadium production is vanadium containing steelmaking slags. The yield of the vanadium extraction process is affected by the composition of the slag, which in turn determines the phases present, the fractions of the phases and the distribution of the elements between the phases. The aim of this thesis was to experimentally investigate the effect of Al2O3, CaO and SiO2 on the phase relations in vanadium containing slags at 1673 K. Synthetic slags, in which the contents of Al2O3, CaO and SiO2 were varied individually, were equilibrated at 1673 K in a vertical resistance furnace. Closed molybdenum crucibles were used to set the oxygen potential of the individual samples. The phases present, the phase compositions and the phase fractions of the samples were studied using SEM-EDS and LOM combined with an image analysis software. The results indicate that the samples consisted of a mixture of a vanadium and iron rich spinel phase and an iron and silicon rich liquid phase at 1673 K. Practically all the vanadium was concentrated into the spinel phase while no free silica or solid phases into which both calcium and vanadium concentrate to a significant extent were observed. The effect of Al2O3 on the phase compositions and the phase fractions was seen to be limited in the range studied. CaO primarily affected the composition of the liquid phases, while the effect on the phase fractions was small. SiO2 affected both the composition and fraction of the phases. The main effect was a decreased fraction of spinel phase, with an increasing vanadium content in the spinel phase as consequence.
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Ficheux, Maxime. "Diffusion multicomposante et environnement structural dans le verre Na2O-CaO-Al2O3-SiO2 contenant du zirconium." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS429.
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Le zirconium est un élément largement répandu sur Terre et aujourd’hui intensivement utilisé sous forme d’oxyde (zircone) ou d’oxyde silicaté (zircon) majoritairement pour ses bonnes propriétés thermomécaniques. A ce titre, il entre notamment dans la composition de matériaux dits « réfractaires » qui sont des céramiques frittées ou électro fondues formant la structure des fours verriers. Le zirconium rencontre ainsi le verre de deux manières différentes: en se déplaçant à haute température depuis les parois du four verrier dans le verre ou en entrant directement dans la composition cible de certains verres nécessitant une forte résistance chimique. La compréhension de son intégration dans le réseau d’un verre silicaté est un premier axe de cette thèse qui est aussi d’intérêt en sciences de la Terre où l’étude de la dissolution de zircon dans les magmas pose les mêmes problématiques. Ces phénomènes de dissolution de réfractaires dans les verres industriels ou de zircon dans les verres géologique dépendent directement de la mobilité du zirconium depuis le cristal dans le verre. Cette mobilité qui peut prendre plusieurs formes (diffusion, convection) sera étudiée dans cette thèse sous l’angle de la diffusion chimique. De nombreuses études présentant déjà des coefficients de diffusions simples de zirconium dans le verre, nous avons souhaité compléter ces données en déterminant des matrices de coefficients de diffusion via la méthode de diffusion multicomposante qui prend en compte les interactions de chaque élément sur la mobilité de tous les autres. Une autre nouveauté est le couplage d’une étude structurale à cette détermination de mobilité<br>Zirconium is widely spread element on Earth and actually intensively used either in its oxide form (zirconia) or in its silicate oxide form (zircon). The main interest of zirconium is to improve thermomechanical properties. This element enters in the composition of refractory materials that are sintered or electro fused ceramics used for glass furnace structure. Zirconium may also enter in glass composition through two different possibilities: at high temperature, it may move from the wall of the furnace to the glass as contaminant or it can enter in the initial glass composition, for which it can increase chemical corrosion by strengthening glass chemical durability. The understanding of its incorporation to the silicate glass structure is the first research axis of this thesis. This axis is also interesting for geosciences where zircon dissolution in geological glasses like magmas have similar issues. This dissolution phenomenon of zircon or refractory directly depends on zirconium mobility from the crystal towards the glass. This mobility may be led by several mechanisms like convection or diffusion. We focused our researches on chemical diffusion determination. Several studies have already determined diffusion coefficient of zirconium in glasses. The innovation of this thesis is the determination of mobility trough multicomponent approach, considering that each element impacts the mobility of all others. Additionally, a structural study of zirconium environment is coupled with the mobility determination
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Dong, Pengli. "Measurements of the thermodynamic activities of chromium and vanadium oxides in CaO-MgO-Al2O3-SiO2 slags." Licentiate thesis, KTH, Materials Science and Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9940.
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<p>In the present work, the thermodynamic activities of chromium and vanadium oxide in CaO-SiO2-MgO-Al2O3 slags were measured using gas-slag equilibration technique. The slag was equilibrated with a gas mixture of CO, CO2 and Ar gases enabling well-defined oxygen partial pressures in the gas mixture (PO2=10-3,10-4,10-5 Pa) at temperatures 1803, 1823K, 1873, 1923 K. The slags were kept in Pt crucibles during the equilibration and the duration of which was 20 h. From a knowledge of the thermodynamic activity of chromium and vanadium in Cr or V in Pt alloy, obtained from literature, and the oxygen partial pressure in the gas stream calculated by Thermo Calc software, the thermodynamic activity of chromium, vanadium oxide in the slags could be observed.An assessment of the experimental studies in earlier works reveal that, the activities of chromium at low chromium contents and vanadium in their respective alloys in platinum exhibits a strong negative deviation from ideality, the logarithms of activity coefficient of these elements were found to increase with increasing mole fractions of these metals in the Pt-alloys.Regarding the slag phase, all the chromium in the slags was assumed to be present in the divalent state in view of the low Cr contents and the low oxygen potentials employed in the present studies. Analogously, vanadium in the slag was assumed to be in the trivalent state in view of the low vanadium contents in the slag and the low oxygen partial pressure in the gas phase. Activity of chromium oxide, CrO decreases with increasing temperature and decreasing content of chromium oxide in slag and oxygen partial pressure in the gas phase. Activity of vanadium oxide, VO1.5 in slag phase shows a negative deviation from ideality. Activity coefficient of vanadium oxide shows a decrease with basicity of slag and the “break point” occurs at about slag basicity of 1 under the oxygen partial pressure of 10-3 Pa and temperature of 1873 K.A relationship for estimating the actual content of chromium, vanadium in slag as a function of activities of chromium or vanadium, temperature, oxygen partial pressure and slag basicity were developed from the present results, the agreement between the estimated and experimental values is satisfactory, especially at lower oxygen partial pressure.</p>
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Ma, Haoyuan. "Study on preparation of high performance CaO-MgO-Al2O3-SiO2 system glass-ceramic with industrial by-products." Scholarly Commons, 2014. https://scholarlycommons.pacific.edu/uop_etds/221.
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Blast furnace slag (BFS), iron ore tailings (IOT), and coal fly ash (CFA) are common industrial by-products with huge annual yield and low reuse rate (< 30%). This research was intended to prepare high performance glass-ceramics from these three industrial by-products. What's more, two energy saving methods were put forward. One was application of single-stage heat treatment, another was mixing cold solid raw material (IOT, CFA) with melted BFS discharged at 1500 in iron making process instead of mixing all the raw material in room temperature and then heating them to melt. Different binary basicity (MCaO /MSiO2 ) and content of Al2O3 had been studied to determine the best formula for high performance glass-ceramic in terms of mechanical properties. Sample 04 (MCaO /MSiO2 =0.4, Al2O3 wt. %=9%) and Sample 05Al-2 (MCaO /MSiO2 =0.5, Al2O3 wt. %=12%) were found with the highest bending strength, 94 MPa and 89 MPa respectively. In addition, with augite and diopside as primary crystalline phase, they also had a Vickers micro-hardness of 6.2 GPa and 6.3 GPa. When applied single-stage heat treatment, sample H4 obtained a bending strength of 77.89MPa and Vickers micro-hardness of 6.5 GPa, very close to H0. Meanwhile, when applied hot liquid-cold solid mixing method, M3 obtained a bending strength of 80.51 MPa, also very close to M0. Which indicates that these two energy saving method are all feasible to be applied to prepare high performance glass-ceramic.
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Polli, Elise. "Incorporação da areia descartada de fundição (ADF) na fabricação de vitrocerâmicos do sistema SiO2 CaO MgO Al2O3." Universidade do Estado de Santa Catarina, 2014. http://tede.udesc.br/handle/handle/1654.
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Previous issue date: 2014-02-07<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The foundry is the fastest way to obtain metals pieces through the casting of liquid metal in green sand moulds. The main components of foundry sands are natural sand, bentonite and carbonaceous additive. During the foundry process, the components lose their mixture characteristics, in addition to the decrease in volume, becoming necessary the discard part of the foundry sand, generating the wasted foundry sand (WFS). In Brazil are discarded approximately 2.76 millions of tons annually and this number has become an environmental concern due to the difficulty of dispose of the residue. In this context,
several lines of research aimed at waste recycling has been studied, among than the use of WSF in glass and glassceramic. This work studies the incorporation of calcined WFS replacing the pure silica in percentages 25, 50, 75 e 100% in manufacturing of glass and glassceramic belonging to the quaternary system SiO2 CaO MgO Al2O3. The samples were melted in alumina crucibles at 1400 °C for one hour. After obtaining, the vitreous samples were underwent annealing at 750 °C for half hour and after, were submitted to spectroscopy ultraviolet visible and heat treatment to 900, 950 and 1000 °C to 90 minutes. After heat treatment, the samples were sent for X ray diffraction analysis, optical microscopy, and only the samples 50 and 100% were sent to scanning electron microscopy, in order to analyze the recrystallization of the samples. For the heat treatment to 900 ° C, the crystalline phases were found akermanita and diopside. As the temperature increased to 950 ° C, the first crystals gehlenita and melilite began to appear and crystallization increased with higher heat treatment temperature. The images obtained by both microscopies relate to the formation of a dendritic structure for the samples 25, 50 and 75% for the three heat treatments. For the heat treatment at 900 ° C crystallization is related to the diopside, and for treatment at 950 to 1000 ° C is related to melilita. For the sample was 100% on both the crystallization heat treatment.<br>A fundição é a maneira mais rápida para a obtenção de peças metálicas através do vazamento do metal líquido em moldes de areia verde. Os principais componentes das areias de fundição são as areias bases, bentonita e pó de carvão. Durante o processo de fundição, os componentes perdem as suas características de mistura, além da diminuição de volume, tornando- se necessário o descarte de parte dessa areia de fundição, gerando a areia descartada de fundição (ADF). No Brasil são descartadas aproximadamente 2,76 milhões ton de areia anualmente e esse número passou a ser uma preocupação ambiental devido à dificuldade do descarte do resíduo. Nesse âmbito, diversas linhas de pesquisa que visam à reciclagem do resíduo vêm sendo estudadas, entre elas a utilização de ADF em vidros e vitrocerâmicos. Este trabalho estuda a incorporação de ADF calcinada em substituição a sílica pura nas porcentagens de 25, 50, 75 e 100% na fabricação de vidros e vitrocerâmicos pertencentes ao sistema quaternário SiO2 Cão MgO Al2O3. As amostras foram fundidas em cadinhos de alumina a 1400 °C durante uma hora. Após da obtenção, as amostras vítreas foram recozidas a 750 °C por meia hora e após, foram submetidas a análise de espectroscopia de ultravioleta visível e também a tratamentos térmicos a 900, 950 e 1000 °C durante 90 min. Após os tratamentos térmicos todas as amostras foram encaminhadas para a análise de difração de raios X, microscopia óptica e apenas as amostras 50 e 100% de ADF foram encaminhadas para a microscopia eletrônica de varredura, a fim de analisar a recristalização das amostras. Para o tratamento térmico de 900 °C, as fases cristalinas encontradas foram a akermanita e o diopsídio. À medida que a temperatura aumentou aos 950 °C começaram a surgir os primeiros cristais de gehlenita e melilita e a cristalização aumentou com a maior temperatura de tratamento térmico. As imagens obtidas por ambas às microscopias relatam a formação de uma estrutura dendrítica para as amostras 25, 50 e 75% ADF para os três tratamentos térmicos. Para o tratamento térmico a 900 °C a cristalização está relacionada com o diopsídio, e para os tratamentos a 950 e 1000 °C está relacionada à melilita. Para a amostra 100% ADF houve a cristalização em ambos os tratamentos térmicos.
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Ben, Kacem Ilyes. "Du cristal au plomb jusqu'aux déchets domestiques : rôle du plomb dans les verres et les vitrocéramiques : étude des systèmes PbO-SiO2, PbO-CaO-SiO2 et PbO-Al2O3-SiO2." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1030/document.
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Ce travail porte sur l’immobilisation du plomb dans les verres et les vitrocéramiques. Le premier volet de cette étude porte sur l’effet de l’incorporation du plomb sur la structure et les propriétés des verres silicatés. Il a été réalisé à partir de compositions de verre simples dans le binaire PbO-SiO2 et les deux ternaires PbO-CaO-SiO2 et PbO-Al2O3-SiO2. Le choix de ces compositions a permis de clarifier le rôle (Modificateur/formateur) du plomb dans ces verres. Des mesures de viscosité, de densité et de la température de transition vitreuse ont été effectuées sur les trois systèmes. Les résultats de ces analyses ont été complétés par des études spectroscopiques (spectroscopies Raman & d’absorption des rayons X) afin de lier les propriétés macroscopiques aux informations structurales dans un ordre à courte- et moyenne-distance. Le deuxième volet de cette étude porte sur la mise en œuvre et la caractérisation de vitrocéramiques obtenues par dévitrification. Les tests de dévitrification ont été effectués principalement sur quelques compositions issues des deux systèmes ternaires PbO-Al2O3-SiO2 et PbO-CaO-SiO2<br>This thesis deals with the immobilization of lead in glasses and glass-ceramics. The first part of this study deals with the effect of the incorporation of lead on the structure and properties of silicate glass. It was conducted on simple glass compositions, in the binary PbO-SiO2 and the two ternaries PbO-CaO-SiO2 and PbO-Al2O3-SiO2. The choice of these compositions made it possible to clarify the role of lead (modifier / former) in these glasses. Measurements of viscosity, density and glass transition temperature were carried out on the three systems. The results of these analysis have been supplemented by spectroscopic studies (Raman and X-ray absorption spectroscopy) in order to link macroscopic properties to structural information in a short- and medium-range order. The second part of this study concerns the implementation and characterization of glass-ceramics obtained by devitrification. The devitrification tests were carried out mainly on some compositions resulting from the two ternary systems PbO-Al2O3-SiO2 and PbO-CaO-SiO2
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Welch, Mark David. "Experimental studies of selected amphiboles in the system Na2O-CaO-MgO-Al2O3-SiO2-H2O-F2 and its subsystems." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/11947.
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Vieira, Luana de Aguiar. "Estudo da sinterabilidade de materiais aluminosos obtidos através da sinterização por fase líquida no sistema Al2O3-MgO-CaO-SiO2." Universidade do Estado de Santa Catarina, 2006. http://tede.udesc.br/handle/handle/1697.
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Previous issue date: 2006-08-29<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The use of aluminium ceramic materials is a reality in many industrial fields. Though, the research development to improve the products and processes that there are nowadays are the same that have been used for the last decade. The majority of the studies aim to explore the most the potencials of alumina that, in spite of having a wide range of applications, has a great deal of its properties. This research to has the objective to obtain ceramic pieces containing hight quantities of alumina, to obtained through the sintering of liquid phase, in addiction to magnesia, kaolin, calcium carbonate and shell of oyster. The raw materials concerning are low prices and are supplier of forming elements at liquid phase: magnesium oxide (MgO), silicium oxide (SiO2), calcium oxide (CaO) respectely. The shell of oyster was used in this research to substitute commercial calcium carbonate, it reduces the price of production as well as minimizing a problem of de are litoranea in special Florianópolis, wich is the dumping of this materials in environment. With the results, it s verified that the presence of liquid phase reduces sgnificantilly the temperature. Obtaining, in this way, one alumina with high density that can be used in many kinds of application. The results also show that the formation of liquid phase and sinterability depend strongly on composition control done through the ternário diagram MgO-CaO-SiO2.<br>O uso de materiais cerâmicos aluminosos é uma realidade em inúmeros setores industriais. Entretanto, o desenvolvimento de pesquisas para o aperfeiçoamento de produtos e processos já existentes se mantém nas últimas décadas. A maioria destes estudos busca explorar ao máximo os potenciais da alumina que, embora possua uma vasta gama de aplicações, tem suas propriedades aproveitadas parcialmente.Este trabalho tem por objetivo a obtenção de peças cerâmicas contendo elevados teores de alumina, obtida através da sinterização por fase líquida, pela incorporação de óxido de magnésio, caulim, carbonato de cálcio comercial e casca de ostra. As matérias-primas utilizadas são de baixo custo e fornecedoras dos elementos formadores de fase líquida: óxido de magnésio (MgO), óxido de silício (SiO2) e óxido de cálcio (CaO) respectivamente. A casca de ostra foi utilizada, nesta pesquisa, como substitutivo do carbonato de cálcio comercial. Sendo assim, além de reduzir o custo de produção, a utilização da casca de ostra minimiza o problema das regiões litorâneas, em especial Florianópolis, que é a deposição incorreta deste material no meio ambiente. Os resultados obtidos comprovam que a presença da fase líquida reduz significativamente a temperatura de sinterização, obtendo-se assim um material aluminoso com elevada densidade que pode ser usado para vários fins industriais. Além disso, os resultados também demonstraram que a formação da fase líquida e a sinterabilidade dependem significativamente do controle da composição realizado através do diagrama ternário MgO-CaO-SiO2.
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Земляной, К. Г. "Влияние способов измельчения на спекание материалов в системе Al2O3 – MgO – SiO2 – CaO – Cr2O3 : автореф. дис. … канд. техн. наук : 05.17.11". Thesis, б. и, 2013. http://hdl.handle.net/10995/19827.
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Shin, Jin-Wook. "The experimantal and theoretical determination of the thermodynamic properties of melts and glasses from the system CaO-MgO-Al2O3-SiO2." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=975613715.
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Shin, Jin-Wook. "The experimental and theoretical determination of the thermodynamic properties of melts and glasses from the system CaO-MgO-Al2O3-SiO2 /." Aachen : Shaker, 2004. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=013110727&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Aygun, Aysegul. "Novel Thermal Barrier Coatings (Tbcs) That Are Resistant To High Temperature Attack By Cao-Mgo-Al2o3-Sio2 (Cmas) Glassy Deposits." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1221589661.
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Soulard, Henri. "Evolution des laves basiques alcalines : étude expérimentale à 1 atmosphère du système analogue synthétique CaO-MgO-Al2O3-SiO2-Na2O (CMASN)." Clermont-Ferrand 2, 1992. http://www.theses.fr/1992CLF21424.
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Cette etude apporte des donnees experimentales sur les assemblages 4, 5 ou 6 phases de l'ensemble liquide-forsterite-diopside-plagioclase-spinelle-melilite-nepheline-orthoenstatite (liq-fo-di-pl-sp-mel-ne-oen). Apres avoir detaille les techniques experimentales et analytiques utilisees, la stchiometrie des phases minerales a ete verifiee: forsterite fo-mo-sp, diopside di-cats-en-jd, plagioclase an-ab-cms3#+s4, spinelle sp-os-ca, melilite ak-geh-sm-(ms3), nepheline nane-an-s4#+-(cms3)-(#+mas2) et orthoenstatite en-mgts-di#+jd. Nous proposons avec a. Provost, une methode descriptive numerique qui permet de quantifier les evolutions des compositions des phases dans les surfaces divariantes, et tient compte des incertitudes analytiques. Les relations de phases (donc les trajets de cristallisation) ont ete determines dans tout le systeme en utilisant (comme pour la verification de la stchiometrie) un programme de calcul de melange (inversion generalisee avec propagation des erreurs analytiques). L'assemblage cardinal des roches basaltiques (liq-fo-di-pl) possede un tres vaste domaine de stabilite reliant les compositions sursaturees a un modale et sous-saturees ou le sp, la mel, la ne et la wollastonite sont stables. Le domaine de compositions est subdivise sur la base de la norme cipw et d'un critere d'alcalinite (ne==2 na/na+al). Les limites ainsi definies correspondent a des changements drastiques dans la solution solide du di, du pl et de la mel. Des analogues synthetiques de la plupart des roches volcaniques naturelles ont pu etre definis, des basaltes aux rhyolites, phonolites et nephelinites. La relecture genetique de la classification internationale nous permet d'inclure les melilitites dans un modele d'evolution des magmas a b. P. : *les basaltes (s. L. ) produisent l'ensemble des magmas differencies par cristallisation de fodi-pl; *4 magmas parents suffisent a engendrer l'ensemble des roches volcaniques (les basaltes, nephelinites a ol, melanephelinites, melilitits a ol). Les melilitites evoluent totalement independamment de tous les autres magmas
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Stoica, Martina [Verfasser], Christian [Gutachter] Rüssel, and Dörte [Gutachter] Stachel. "Photoinduced crystallisation of CaF2 from a Na2O/K2O/CaO/CaF2/Al2O3/ZnO/SiO2 glass / Martina Stoica ; Gutachter: Christian Rüssel, Dörte Stachel." Jena : Friedrich-Schiller-Universität Jena, 2018. http://d-nb.info/1170396410/34.
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Walk-Lauffer, Bernd. "Untersuchung des Einflusses von Sulfaten auf das System CaO-SiO2-Al2O3-K2O-H2O mittels Wärmeflusskalorimetrie und In-situ-Neutronenbeugung unter hydrothermalen Bedingungen." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=967520762.
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Veit, Ulrike [Verfasser], Christian [Gutachter] Rüssel, and Dörte [Gutachter] Stachel. "Entwicklung hochfester Gläser aus dem CaO-(MgO-)Al2O3-SiO2-System für die Verstärkung von Kompositmaterialien / Ulrike Veit ; Gutachter: Christian Rüssel, Dörte Stachel." Jena : Friedrich-Schiller-Universität Jena, 2018. http://d-nb.info/117039678X/34.
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Shin, Jin-Wook [Verfasser]. "The experimental and theoretical determination of the thermodynamic properties of melts and glasses from the system CaO-MgO-Al2O3-SiO2 / Jin-Wook Shin." Aachen : Shaker, 2004. http://d-nb.info/1181602912/34.
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Zolotar, Mayard Samis. "Sintese de vidros e vitro-ceramicas do sistema SiO2-AL2O3-CaO-CaF2 por Sol-Gel : caracterização e aplicação em cimentos de ionomero de vidro." [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263548.
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Orientadores: Cecilia Amelia de Carvalho Zavaglia, Carlos Kenichi Suzuki<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica<br>Made available in DSpace on 2018-07-25T02:17:04Z (GMT). No. of bitstreams: 1
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Previous issue date: 1999<br>Resumo: Este trabalho teve como objetivos a síntese, através do processo sol-gel, de vidros e vitrocerâmicas de diferentes composições, no sistema SiOrAhO3-CaO-CaF2, formulação básica do componente inorgânico dos cimentos de ionômero de vidro comerciais, sua caracterização microestrutural e uma avaliação preliminar do tempo de cura e da resistência mecânica à compressão dos cimentos obtidos a partir destes materiais. Utilizou-se a técnica de modelagem de misturas na seleção das composições sintetizadas neste trabalho. A caracterização dos vidros e vitro-cerâmicas obtidos realizou-se através de análise química por fluorescência de raios-x e espectroscopia de plasma, diftação de raios-x, análises termogravimétrica e termodiferencial,
espectroscopia de Ínftavermelho com transformada de Fourier, espectroscopia RAMAN, microscopia eletrônica de varredura convencional, acoplada à análise dispersiva de raios-x e microscopia eletrônica de alta resolução. Concluiu-se ser possível obter vidros e vitro-cerâmicas ricos em flúor, em temperatura ambiente, através da técnica de processamento sol-gel. Está última mostrou-se adequada para a síntese de vidros e vitro-cerâmicas do sistema estudado, sendo estes últimos aplicáveis como componentes inorgânicos de cimentos de ionômero de vidro para uso odontológico<br>Abstract: The present work aimed at the synthesis of sol-gel glasses and glass ceramics in the SiO2-AhO3-CaO-CaF2 system, the basic formulation of the inorganic component of commercial glass ionomer cements, their microstructure characterisation, and a preliminary evaluation of the setting time and compressive strength of the cements obtained from these materials. The compositions employed in this work were chosen from a design generated through the mixture design technique. The characterisation of the sol-gel glasses and glass-ceramics was carried out by chemical analysis through x-ray fluorescence and inductive coupled plasma spectroscopy, x-ray diffraction, thermogravimetry and differential thermal analysis, infrared and RAMAN spectroscopies, conventional scanning electron microscopy with x-ray dispersive analysis, and high resolution scanning electron microscopy. Fluorine-rich glass and glass-ceramics were obtained at room temperature through the sol-gel processing technique. The latter also proved to be adequate for the synthesis of glasses and glass-ceramics in the above system which are suitable to be used as the inorganic component of glass ionomer dental cements<br>Doutorado<br>Materiais e Processos de Fabricação<br>Doutor em Engenharia Mecânica
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Pina, Sandra Cristina de Almeida. "Preparação de vidros e vitro-cerâmicos do sistema SiO2-AL2O3-B2O3-CaO-MgO-Li2O-(K, NA)2O-F para potenciais aplicações em medicina dentária." Master's thesis, Universidade de Aveiro, 2005. http://hdl.handle.net/10773/2275.
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Mestrado em Engenharia de Materiais<br>O presente trabalho teve por finalidade investigar a influência da
substituição catiónica em vidros e vitro-cerâmicos à base de Ca-mica e
a produção de materiais com propriedades adequadas para aplicações
de interesse tecnológico.
Considerou-se como referência a composição CaMg3Al2Si2O10F2 e
investigou-se a influência da substituição (parcial ou completa) de Mg
por Li e de Al por B no processo de cristalização e nas propriedades
dos vitro-cerâmicos resultantes.
Os materiais produzidos foram caracterizados por recurso a diversas
técnicas experimentais, nomeadamente, análises térmicas (ATD e
dilatometria), difracção de raios X, espectroscopia de Raman,
microscopia electrónica de varrimento e espectroscopia de energia
dispersiva. A densidade e as propriedades mecânicas foram avaliadas
pelo de método de Arquimedes, microdureza de Vickers e ensaios
mecânicos à flexão, respectivamente, enquanto para o estudo da
durabilidade química se recorreu à imersão em ácido acético.
Os resultados experimentais mostraram que o vidro de referência só
funde adequadamente a cerca de 1550ºC, enquanto todos os vidros
dele derivados puderam ser facilmente fundidos e vazados a
temperaturas baixas (≈1350ºC).
A cristalização e propriedades dos vitro-cerâmicos obtidos a partir dos
vidros base mostraram-se muito sensíveis à substituição dos catiões. O
início da cristalização foi deslocado para temperaturas mais baixas na
presença de B e de Li. Por outro lado, a substituição completa de Al por
B causou um decréscimo da cristalinidade dos vitro-cerâmicos, uma
fusão parcial após tratamento térmico a temperaturas acima de 850ºC,
e tornou os vidros mais propensos a uma cristalização em volume.
Os vidros apresentaram unidades Q1, Q2, e Q3 do silício e ligações
Al∅4
- na presença de Al, e/ou unidades triangulares B∅2O- e
tetraédricas B∅4
- na presença de B. A presença de Li não causou
alterações significativas a nível estrutural, enquanto que a presença de
fósforo favoreceu a formação de unidades isoladas de coordenação
tetraédrica do tipo PO4
4-.
A composição de referência foi a única em que se formou a mica
(xantofilite) após tratamento térmico a 650ºC. A substituição, parcial ou
completa, de Mg por Li e de Al por B levou à formação de variadas
fases, tais como, inossilicatos (piroxenas e anfíbolas), nesossilicatos
(humite e forsterite) e, num caso, feldspato de Ca (anortite). Os vitrocerâmicos
com P na sua composição apresentaram fases variadas, tais
como, diopsido, borato de Mg, fosfito de B, SiO2e CaF2.
O uso de uma rocha natural à base de Li incorporou inevitavelmente
outros metais alcalinos, como K e Na. O vidro contendo todos os
catiões (Li, Na, K, Al) mostrou-se mais propenso a uma cristalização
homogénea em volume. Os vitro-cerâmicos apresentaram diversas
fases cristalinas a diferentes temperaturas (anfíbolas, Ca-mica,
forsterite, espinela e KLi-mica. Estes materiais são mais baratos e
apresentaram boas propriedades ópticas de brancura, translucidezopacidade,
e propriedades químicas e mecânicas promissoras para
diversas aplicações.
ABSTRACT: The present work aimed at investigating the influence of cation
substitution in glass and glass-ceramics based on Ca-mica and at the
production of materials with suitable properties for applications of
technological interest.
Considering the composition CaMg3Al2Si2O10F2 as reference, the
influence of substitution (partial or complete) of Li for Mg and B for Al on
crystallization process and on the properties of the resulting glassceramics,
was investigated.
Several experimental techniques were employed for the characterization
of the produced materials, such as thermal analysis (DTA and
dilatometry), X-ray diffraction, Raman spectroscopy, scanning electron
microscopy and energy dispersive spectroscopy. The density and the
mechanical properties were measured by the Archimedes method, and
Vickers microhardness and flexural strength measurement, respectively,
while the study of chemical durability was made by imersion in acetic
acid.
The experimental results showed that the reference glass was melted at
near 1550ºC, while all the other glasses derivated from it were easily
melted and cast at lower temperatures (≈1350ºC).
The crystallization and the properties of glass-ceramics crystallized from
the base glasses were very sensitive on cations substitutions. Initial the
onset of crystallization was shifted to lower temperatures in the
presence of B and Li. On the other hand, the complete substitution of B
for Al caused significant lowering of crystallinity in the glass-ceramics,
partial melting after heat treatment at temperatures higher than 850ºC,
and the resulting glasses became prone to bulk crystallization.
The glasses showed Q1, Q2, eQ3 silicon units and Al∅4
-, in the
presence of Al, and/or triangular, B∅2O-, and tetrahedral units B∅4
- in
the presence of B. The presence of Li didn’t cause significative
modifications in the structure, while the presence of P favoured the
formation of isolated tetrahedral coordinated units of type PO4
4-.
The formation of mica (xanthophyllite) only occurred in the case of
reference composition after heat treatment at 650ºC. Substitution,
partial or complete, of Li for Mg and B for Al showed the formation of a
variety of phases such as, inosilicates (pyroxenes and amphiboles),
nesosilicates (humite and forsterite) and, in a particular case, Cafeldspar
(anortite). The glass-ceramics with P in their composition
showed different phases, such as, diopside, Mg-borate, B-phosphite,
silica and CaF2.
The use of a natural rock based on Li inevitably introduced other alkalis
metals, such as K and Na. The glasses which contain all the cations (Li,
Na, K, Al) were prone to homogenous bulk crystallization. The glassceramics
showed different crystalline phases at different temperatures
(amphiboles, Ca-mica, forsterite, spinel and KLi-mica). These materials
are cheaper and exhibited good optical properties of whiteness,
translucency-opalescence, and chemical and mechanical properties
which are promising for several applications.
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Simon, Hellgren. "Secondary Steel Metallurgy Slag Design and MgO-C Refractory Implications : Theoretical and Practical Considerations." Thesis, Luleå tekniska universitet, Industriell miljö- och processteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-76339.
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MgO-C based refractory materials, often used in secondary steel making, are exposed to variouswear mechanisms in its application. The wear could be divided into oxidative, chemical andabrasive categories, all behaving differently and all being influenced by different factors. Dueto the importance of minimizing material loss and to the environmental challenges to run asustainable industry, it is of interest to gain more knowledge of the behavior of the refractorymaterial in use. The present thesis work specifically investigated slag designed of the CaOSiO2-Al2O3-MgO (CSAM) system as well as the chemical and oxidative wear mechanisms ofthree different MgO-C based refractory materials from Höganäs AB, Halmstadverken, whichcontained 5, 10 and 12 wt% carbon (labeled T05, T10 and T12). Different CSAM slags weredesigned to meet certain process criteria such as MgO and CaO saturations and wereinvestigated through thermodynamic calculations using the FactSage software and throughlaboratory scaled slag smelting experiments. The oxidation effect on the refractory material wasalso studied through pre-heating simulations in chamber furnaces, similar to the pre-heating ofa re-built ladle furnace.The thermodynamic calculations made in FactSage 7.0, using the FactPS and FToxid databases, resulted in a few different slag designs with different properties. A few different slagsfulfilled the CaO and MgO saturation limits proposed by Höganäs AB and could be consideredto test experimentally for further evaluation. The simulations also showed trends on how theliquid viscosity behaved with different slag compositions and how the solids content changedwith temperature.The oxidation experiments were performed on the different MgO-C refractory types, where thebricks with 10% carbon also contained Al2O3 antioxidants. The experiments showed that themass loss during the pre-heating is greater for refractory with higher carbon content, withexception to T10, where the mass losses were measured to 3.76 – 4.01%, 1.06 – 1.28% and6.28 – 6.33% for T05, T10 and T12 respectively. Further, the oxidation depth of each materialwas measured to 9-10 mm, 2-3 mm and 2-5 mm for the T05, T10 and T12. The experimentsalso showed that T12 refractory in particular was very susceptible to abrasive wear after beingoxidized.The slag smelting experiments were carried out through two different methods, by melting slagin MgO-C crucibles and by melting pressed slag briquettes on top of refractory bricks. Theformer tests mainly showed that the methodology was not suitable for this type of refractorymaterial due to the crucibles cracking during the experiments. The latter experiments showedsome general behaviour of the different components in the slag, where Ca, Al and Fe stayednear the surface, and Si and Mg penetrated deeper. The spinel formation at the refractory surfacewas then concluded to be the reason for Al not penetrating deeper. Further it was concludedthat no significant difference in refractory dissolution was seen between slags with- and withoutMgO, other than possibly a small increase in refractory dissolution for the latter.
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Song, Minho. "A Study on the Correlation between Ladle Glaze and Non-Metallic Inclusions in the Ladle Treatment." Doctoral thesis, KTH, Mikro-modellering, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-27640.
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In the present thesis, the correlation between ladle glaze and non-metallic inclusions in the ladle treatment was studied. A number of industrial trials with full scale ladle and laboratory works were performed to investigate the inclusions in the ladle treatment. BaO was used as tracer in the ladle slag to investigate the effect of slag on inclusion composition and the formation of non-metallic inclusions by ladle glaze. BaO was detected in the inclusions of all followed heats. This observation showed strong evidence for the generation of non-metallic inclusions by the ladle glaze. The increase of the fractions of BaO containing inclusions and their average content of BaO in the first heat with tracer suggested that the effect of slag on the composition of inclusions was a very slow process. The detachment of ladle glaze and the chemical transformations of oxide solution in the MgO matrix were investigated. The experimental results evidently showed that the ladle glaze could be the source of inclusions continually during the ladle treatment. Samples of liquid oxide solution to simulate the liquid oxide inclusions carried over from EAF were equilibrated with molten steel under controlled atmosphere. The results along with thermodynamic calculation suggested that the SiO2 content of inclusions from EAF could be considerably reduced by dissolved aluminium in the steel. This would explain the vanishing of inclusions containing high SiO2 content after deoxidation. Due to the lack of experimental data, the viscosities of slags in the Al2O3-CaO-MgO-SiO2 system were measured using the rotating cylinder method in the temperature range of 1720 to 1910 K. Eight different slag compositions related to the secondary steel making operations were selected. Viscosities in this system and its sub-systems were expressed as a function of temperature and composition based on the viscosity model developed earlier at KTH. The activities of oxide components in the Al2O3-CaO-MgO-SiO2 systems at 1873 K were measured by equilibrating liquid slag and metal. Either silicon or copper was used as the metal phase and the oxygen partial pressure was controlled with different mixing rates of Ar and CO gas flow in equilibrium with graphite. Iso-activity lines were drawn from the measured activity values in the isothermal section of the slag systems. Nine series of industrial trials were carried out using the same ladle in each series to examine the effect of ladle slag on the number of non-metallic inclusions in the next heat. It was found that the number of inclusions increased with SiO2 content of the ladle slag in the previous heat. No clear trends were found for the effects of viscosity and MgO activity of the previous slag on the number of inclusions. Theoretical analysis based on the experimental results suggested that the formation of 2CaO∙SiO2 followed but the dusting of the compound made the refractory more porous, which was reasonable for the number of non-metallic inclusions.
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Baasner, Amrei [Verfasser], Sharon L. [Akademischer Betreuer] Webb, Ray [Akademischer Betreuer] Dupree, et al. "The Influence of Fluorine, Chlorine and Water on the Rheology and Structure of Na2O-CaO-Al2O3-SiO2 Melts / Amrei Baasner. Gutachter: Ray Dupree ; Burkhard C. Schmidt ; Harald Behrens ; Gerhard Wörner ; Andreas Pack. Betreuer: Sharon L. Webb." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2014. http://d-nb.info/1051530733/34.
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Purwin, Horst [Verfasser], Hans-Joachim [Akademischer Betreuer] Kleebe, and Gerhard P. [Akademischer Betreuer] Brey. "Eine experimentelle Studie des Oxidationszustandes von Eisen in Granat und Klinopyroxen als Funktion der Temperatur im System CaO-FeO-Fe2O3-MgO-Al2O3-SiO2: Implikationen für die Granat-Klinopyroxen-Geothermometrie / Horst Purwin. Betreuer: Hans-Joachim Kleebe ; Gerhard P. Brey." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2012. http://d-nb.info/1106453387/34.
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Mao, Huahai. "Thermodynamic modelling and assessment of some alumino-silicate systems." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-251.
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Kang, Young Jo. "Some aspects of non-metallic inclusions during vacuum degassing in ladle treatment : with emphasize on liquid CaO-Al2O3 inclusions." Doctoral thesis, Stockholm : Department of Materials Science and Engineering, (Materialvetenskap), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4288.
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Dablé, Pierre Jean-Marie Richard. "Etude thermodynamique de la solubilité du platine et du rhodium dans les oxydes liquides." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0137.
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Les platinoides dont sont issus le platine et le rhodium presentent des caracteres particuliers qui font d'eux, des indicateurs geochimiques. Ces elements par leur presence dans des roches, peuvent fournir des indications sur les conditions de leur mise en place au cours du processus magmatique. C'est sur cette base, que de nombreuses etudes sont entreprises pour etablir les parametres susceptibles de controler ce phenomene. Dans le but d'obtenir des informations d'ordre general, nous avons etudie dans le cas de bains d'oxydes simples cao-al#2o#3-sio#2, l'influence de la composition du bain, et de la phase metallique sur la solubilite de ces metaux en fonction de la pression partielle d'oxygene. Deux techniques ont ete utilisees dans cette etude, a savoir: l'equilibre triphasique, metal/bain d'oxydes/gaz et la chronopotentiometrie. De cette etude, nous avons pu mettre en evidence la passivation des phases metalliques, etablir la speciation des elements etudies ainsi que les diagrammes de predominance. Les speciations en fonction du potentiel croissant d'oxygene etablies sont pour le platine, pt/pt#2#+/pt#4#+/pt#6#+ et pour le rhodium, rh/rh#2#+/rh#3#+ et rh#4#+. La phase metallique de platine se passive par la formation a l'interface des oxydes pto et pto#2 selon les pressions partielles d'oxygene et par rho dans le cas du rhodium. La formation d'un spinelle pt#2o#3rho a la surface de l'alliage de pt/rh a de meme ete mise en evidence
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Talapaneni, Trinath. "Physicochemical Properties of CaO-MgO-SiO2-Al2O3 Synthetic Slag." Thesis, 2019. http://ethesis.nitrkl.ac.in/10010/1/2019_PhD_TTalapaneni_513mm1060_Physicochemical.pdf.
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Blast furnace slag composition has a very important bearing on its physicochemical characteristics which affects the degree of desulphurization, coke consumption, smoothness of operation, gas permeability, heat transfer and fluidity which in turn affects the softening and melting behavior in the cohesive zone. Due to the diminution of high-quality iron ores, blast furnaces are running with iron ores having a high Al2O3/SiO2 ratio (as high as 4.17 in case of Sierra Leone ores, but the ideal Al2O3/SiO2 ratio should be in the order of 0.6-0.7) and this produce slag containing Al2O3 25-30%. Al2O3 being a refractory oxide will increase the liquidus temperature of the slag, due to this, the furnace has to operate at high temperatures, and this involves high coke consumption, which ends up with high silicon content in hot metal. Whereas, silicon pick up in the hot metal can be reduced by lowering the position of cohesive zone (CZ). This is possible with slags having a high softening temperature, coupled with a relatively low flow temperature increases the formation of a narrow cohesive zone at the lower part of the blast furnace, and this will increase the permeability in the CZ. Also, these slags are highly viscous and show less efficient desulphurization. The former is due to the network forming ability of Al2O3 and later is due to the increase in the activity of sulphur in slag. All the above factors will influence the working condition of a blast furnace and diminish the quality of hot metal. Apart from this the volume of the slag also increases. The Overall production of blast furnace slag may be estimated as equivalent to 25% to 30% of crude (pig) iron production compared to steel furnace slag as about 10% to 15% of crude steel output [217].
Therefore, the present work is focused on the study of physicochemical properties like liquidus temperature, viscosity and desulphurization ability of CaO-MgO-SiO2-Al2O3 quaternary slag system.
The effect of Al2O3, MgO and CaO/SiO2 ratio on flow characteristic temperatures are carried out using a high-temperature microscope in accordance with German standard 51730. Slag with Al2O3 (25-30 %), C/S (0.9-1.4) and MgO (4-12 %) ensures Al2O3 (30 %), C/S ratio of 1.4 and MgO (8 %) as short slag. Whereas, slags with C/S (0.8-1.6) and MgO (8-16 %) are showing Al2O3 (30 %), C/S ratio 1.2 and MgO (12%) as short slag. Also, phase diagrams and XRD analysis for slag samples reveals that all the slags are falling in Anorthite-Melilite-Spinel region.
Viscosity experiments are carried out for slag composition of Al2O3 (25-30 %), C/S (0.8-1.6) and MgO (8-16 %) using vertical rotating type (Model VIS 403 HF) high-temperature viscometer in the temperature range of 1748 K to 1848 K. A relationship between viscosity and the slag structure is intent by Fourier Transform Infrared (FTIR) and Raman spectroscopy. Chemical thermodynamic software FactSage 7.0 is used to predict viscosity of slags. It is observed that an increase in CaO/SiO2 ratio and MgO content in the slag depolymerizes the silicate structure. This leads to a decrease in viscosity and activation energy of the slag. Also, an addition of Al2O3 content increases the viscosity and activation energy of slag by polymerization of aluminosilicate structure.
Desulfurization ability of slags is determined for slag composition of Al2O3 (25-30 %), C/S (0.8-1.6) and MgO (8-16 %) at a temperature of 1773 K using slag-metal equilibrium technique. The sulphur content in the slag as well as in metal after desulfurization reaction is analyzed using XRF (X-ray Fluorescence Spectroscopy) for calculating sulphur partition ratio (Ls) of the slags. The influence of Al2O3, CaO/SiO2 ratio and MgO content on Ls has been studied. It is observed that Ls increase with an increase in CaO/SiO2 ratio and MgO content, but it reduces as the Al2O3 content increase in slag. Also, the amount of bridge oxygen (Oo) decreases with increase in basicity and MgO content. However, Oo increases with increase in Al2O3. It is witnessed that the experimental values closely fit with the values obtained from the corrected optical basicity model.
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CHEN, YING-HSIN, and 陳穎興. "Ag-Diffusion, Microstructures, and Electrical Properties of Al2O3-and SiO2-dopings in LTCC CaO-Al2O3-B2O3-SiO2 Glass." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/4wr53y.
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碩士<br>明志科技大學<br>機械工程系機械與機電工程碩士班<br>105<br>In recent years, microwave dielectric materials and components such as filters, resonators, high-frequency antenna, medium antenna, medium guided wave circuit, etc. have been developed rapidly. In addition, high-frequency microwave substrate had been widely applied in different high-frequency communication systems. To effective cost reduction, low temperature co-firing ceramic (LTCC) technology is developed for fabrication of microwave dielectric materials and components. However, the silver diffusion happens easily during sintering for a co-firing with microwave dielectric ceramic and silver electrode. An reduced silver diffusion between microwave dielectric ceramic and Ag-electrode is an important issue for LTCC development.
In this work, the low-k microwave materials using x wt% Al2O3 doped CaO-Al2O3-B2O3-SiO2 (x=0~30) (Al2O3 + glass) and x wt% SiO2 quartz (x = 0 ~ 6) doped CaO-Al2O3-B2O3-SiO2 glass were co-fired with silver electrode. The results show that the higher sintering temperature and the longer holding time increase silver diffusion and SiO2 doping can inhibit silver diffusion. the mechanical strength increases to 11.8 kpa and the dielectrical properties including k and Df values are 5.6 and 0.124, respectively. The 6 wt% SiO2 doped CaO-Al2O3-B2O3-SiO2 glass shows a silver diffusion distance ~ 7.8μm, which was shorter than that of 8wt% Al2O3 doped CaO-Al2O3-B2O3-SiO2 glass with a diffusion distance ~ 22.7μm. Meanwhile, the calculation of activation energies for the 8wt% Al2O3 + glass and 6wt% SiO2-8wt%Al2O3 co-doped glass are 296 kJ/mole and 373 kJ/mole, respectively. The CaO-Al2O3-B2O3-SiO2 glass with 6wt% SiO2-8wt%Al2O3 co-doping shows higher activation energy and restricts silver diffusion due to SiO2 addition.
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Yang, Ming-jui, and 楊明叡. "The Crystallization Behavior of BaO-CaO-Al2O3-B2O3-SiO2 Sealing Glass." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/55287929132904683050.
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碩士<br>大同大學<br>材料工程學系(所)<br>99<br>The sealing glass is used widely, such as electronic components sealing and solid oxide fuel cell sealing. At different operating temperatures, the effect of the glass are different. If the glass has the crystallization, it has the problem of mismatch thermal-expansion coefficient to affect the quality of SOFC components.
There are two glass series in this thesis. The main glass composition are G18 (35BaO-15CaO-5Al2O3-10B2O3-35SiO2 (mol%)) glass. Series 1 change the content of B2O3. Series 2 add the other oxides (TiO2, ZrO2 or P2O5). The thermal properties and crystal behaviors of the glasses can be improved by two ways. In this study, the thermal properties of the glass can be measured by DTA and TMA。The crystalline phase distribution is analyzed by the depth-profile of X-ray diffraction. The effect of the nucleation of the glasses is observed by SEM. The results indicate that, the glass of adding the content of B2O3 7 and 13 mol% have nucleation treatment effect. But the glass of adding the content of B2O3 7 mol%，has weak thermal-expansion coefficient. The glass of adding the content of B2O3 13 mol%, has the best nucleation treatment effect in series 1. The glasses of the series2 have nucleation treatment effect. The glass of adding the content of P2O5 3 mol%, has the best nucleation treatment effect. In series 1 and series 2, the glass of adding the content of P2O5 3 mol%, have better thermal properties and nucleation treatment effect.
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Lu, Hsing-Cheng, and 盧幸成. "Effect of ZnO on Cement Manufacture from Pure CaO-Al2O3-SiO2 Mixtures." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/f6cbfg.
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碩士<br>國立成功大學<br>環境工程學系碩博士班<br>90<br>To investigate the role of ZnO played in CaO-Al2O3-SiO2 sintering system, experimental mixture design was applied. Pure CaO, Al2O3, SiO2 were mixed according to three component mixture design and all mixtures were doped with several doses of ZnO. After been sintered at 1450°C for three hours, sintered sample was examined with X-ray diffraction (XRD). Combined with lithium fluoride (LiF) XRD semi-quantification technique and hydration observation, the effect ZnO on cement manufacture was established. On the other hand, aluminum hydroxide was selected as alternative material to investigate the feasibility of utilizing aluminum replacement in cement production.
The result shows that major crystalline phase of sintered samples doped with 3%(w/w) ZnO experienced no phase transformation except sample batched with molar ratio 2:3 (CaO:SiO2). ZnO seems to have little interference on characteristic phase formation with 3% addition. In the experiments of aluminum hydroxide replacement, the semi-quantification analysis shows that major crystalline phase is mainly the same. Sludge produced from aluminum series coagulant, which contains mostly aluminum hydroxide, might have the potential of being used as cement manufacturing alternative raw material.
With microwave digestion followed by inductively coupled plasma spectrometer, ZnO gas-solid phase distribution was analyzed. The results show that raw materials with molar ratio of 3:2 (SiO2:Al2O3), 5:12:3 (CaO:SiO2:Al2O3) and 2:3:3 (CaO:SiO2:Al2O3) have better ability of constraining ZnO in the solid phase.
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HU, CHIA-WEI, and 胡嘉維. "Effect of Adding Strontia on MgO-CaO-Al2O3-SiO2-P2O5 Bioactive Glass." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/9vq33b.
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碩士<br>中臺科技大學<br>牙體技術暨材料系碩士班<br>107<br>Strontium is believed to contribute to the growth of bone cells. By the way of degradation, strontium-containing bioactive glass would release strontium ions into the surrounding environment, to promote the growth of bone tissue. In this study, strontia-containing bioactive glass with composition of MgO 3%, CaO (35-x)%, Al2O3 8.6%, SiO2 41.4%, P2O5 12%, SrO x% (x = 0, 1, 3, 5, 10 wt.%), denoted by xSrAA, respectively, were synthesized using conventional melting-quenching technique. The effects of strontia on glass transition temperatures, apatite-forming ability, degradation in physicochemical solution, and ion release were investigated. The experimental results showed that the glass transition temperatures were in the range of 741-770°C. The strontia would widen the sintering window, which means the glass could maintain the glass phase condition with longer sintering duration. The test specimens were immersed in PBS solutions to evaluate the terms of degradation. It revealed that the pH value increased gradually with immersion duration. However, the more strontia content, the steadier pH values were in immersing PBS solutions. In addition, strontia also reduced the apatite deposition in PBS solutions. All these results revealed that SrAA glasses were more stable than AA glasses in PBS solutions. After co-cultured with MG-63 cells, 5SrAA showed the best cell activity.
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Wu, Chun Wei, and 吳俊緯. "Crystallization Kinetics and Dielectric Properties of Low-fire CaO-Al2O3-SiO2 + Alumina System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/02614157852593067184.
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碩士<br>國立清華大學<br>材料科學工程學系<br>103<br>Effects of alumina on the devitrification kinetics and dielectric properties of a low-dielectric CaO-Al2O3-SiO2 glass powder have been investigated. Crystalline phases including pseudowollastonite, anorthite and cristobalite are formed during firing of the glass. The crystallization kinetics of crystalline phases follows the analyses of the Avrami equations. Combined with the results of reduced growth rate, the rate-controlling step appears to be alkali ion diffusion in the glass. With added alumina content greater than a critical value, the above crystalline phases are completely suppressed but anorthite is formed. This result is attributed to the dissolution of alumina into the glass which changes the composition of the glass. By using Avrami analysis, the rate-controlling mechanism changes to reaction-controlled kinetics which has an activation energy closely related to Al-O bonding. With increasing anorthite formed, the composites exhibit insignificant change in dielectric constant, but a significant decrease in dielectric loss.
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ZHONG, CHENG-HAN, and 鍾承翰. "Development of SiO2 - CaO - Al2O3 – BaO glass sealants for solid oxide fuel cell." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/j77ap5.
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碩士<br>國立臺北科技大學<br>材料科學與工程研究所<br>106<br>The purpose of this study was to develop a Si-Ca-Al-Ba (SCAB) system an alkaline earth-containing silicate encapsulated glass. After that, Si-Ca-Al-Ba glass system with better overall properties was selected to add ZnO、Y2O3 and NiOto further improve its packaging and mechanical properties, and then add NiO and Sm2O3 to improve the CTE and Tg points for solid oxide fuel cells. SCAB crystallographic initial temperature Tx above 800oC with a higher softening point and a lower coefficient of thermal expansion (CTE) indicates that glass may have better thermal stability but may have a coefficient of thermal expansion mismatch. Adding a small amount of ZnO and NiO can lower the crystallization temperature Tc of the glass so that the glass can retain the original glass phase. SCAB No main crystalline phase was observed after bonding temperature of 800oC for 1 h, then no new crystallization peak occurred after 200 h of working temperature of 700oC. In the glass and stainless steel (SUS430) the proportions are all flat at the interface and no significant diffusion occurs between the glass and the stainless steel. However, due to the low thermal expansion coefficient, there are cracks in the interface. The leakage rate shows good adhesive which SCAB-NiO were 0.08 sccm/cm respectively at 800oC dwell 1 h then soake at 700oC for 5 h. In the bonding strength test, the maximum bonding strength was obtained when the temperature was 800oC for 4 hours, of which SCAB-9 was the best, the average bonding strength was 10.23 MPa, followed by SCAB-5, The bonding strength is 10.15 MPa.
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Lin, Kun-Hsien, and 林坤賢. "The study of physical and chemical properties of CaO-Al2O3-SiO2-MgO-CaF2 slags." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/68533133807376426555.
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碩士<br>國立中興大學<br>材料科學與工程學系所<br>102<br>The desulfurization reactions in steel making are associated with basicity, melting point, viscosity. In this study, design six groups (A-F) with a low melting point,different basicity, and different composition phase. In order to make a comparison, three control groups which are similar to steelworks slag waste (A1-A3) were designed. The three control groups are content 10% CaF2. By identify the physical and chemical properties of these groups, to discuss the impact of the desulfurization reaction.
In this experiment, using the frequency induction furnace to pre-melting the nine groups, simulating the patterns after the high-temperature reaction of nine groups. After
pre-melting, conducted a series of experiments as viscosity, F-CaO, XRD, XRF, DTA,Raman. Simulate the sulfur distribution ratio and desulfurization rate by using Thermo-Calc software.
In the results and discussions, it is confirm the pre-melting is success by XRD and XRF. In F-CaO testing, the group of Al-killed steel has higher F-CaO. The content of
F-CaO increase when the percent of Al2O3 increase. The melting point of the six groups are about 1470-1510°C, the three control groups are about 1400°C. The viscosity of Si-killed steel is higher, because of higher SiO2 content. But, when the CaF2 is add, it will break the cross-linked network of SiO2 and Al2O3 and reduce the viscosity. As the SiO2 decrease, the group of Al-killed steel has lower viscosity.
After the thermodynamic simulation, The group E has the best desulfurization rate and Ls of six testing groups. The group E has the best efficiency (desulfurization rate：
56%), because it has high value of Cs, enough F-CaO, low viscosity. The efficiency is closest to control group. High optical basicity has good properties, such as low viscosity,high F-CaO, Ls and desulfurization rate. It is helpful for desulfurization.
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Su, Yu-Lang, and 蘇育瑯. "Effect of FeO content on High-temperature properties in FeO-CaO-SiO2-Al2O3-MgO system." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/48217471126918834976.
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碩士<br>國立中興大學<br>材料科學與工程學系所<br>105<br>In this study, FeO-CaO-SiO2-5% MgO-5% Al2O3 slag system (C / S = 2.5 and 3.0, FeO = 10 ~ 40 wt. (%)) with different basicity and FeO ratio was designed by Thermo-Calc thermodynamics simulation. The Actual composition of slag was confirmed by WDS-XRF analysis, the Fe chemical titration and XRD phase identification. In the high temperature characteristic analysis, using DV III RV viscometer, the high temperature optical image observation, and pre-thermodynamics simulation investigate the softening, melting and flow properties. Finally, the actual dephosphorization test and foaming height analysis were carried out to find out optimum composition range of dephosphorization agent and foaming agent in FeO-CaO-SiO2-5% MgO-5% Al2O3 slag system.
The x-ray diffraction results revealed that the composition of the FeO content (9.9-43.2 wt. (%)) at different basicity is composed of FeO, Ca2SiO4 and CaMoO4. It was found that the viscosity of slag was affected by Ca2SiO4 solid particles, and the viscosity increased with the increase of basicity or the decrease of FeO content, and thus C/S=2.1-9.9%FeO and C/S=2.6-20.6%FeO have a higher viscosity. Through the high temperature optical image observation, it found that the viscosity of 1300cP above and Ca2SiO4 solid fraction rate of 20% of the formula, high temperatures to maintain structural stability and slow down the softening rate enhance the melting temperature as well; and the viscosity of 183cP below and Ca2SiO4 solid fraction ratio were less than 10% of the formula, due to a large number of FeO melting in advance leading to rapid disintegration of the structure, which significantly reduce the melting temperature, making slag flow better.
The results show that the viscosity is between 25cP and 1810cP, and the foaming index is linearly proportional to the viscosity, and the foaming index of C/S=2.6-20.6%FeO is 109.7% at 1560oC, which is the best performance of the foam formulation. In the dephosphorization capacity assessment, the thermodynamic empirical formula that in the high basicity and the appropriate FeO content of the dephosphorization agent can effectively improve the ability of dephosphorization. The results showed that the dephosphorization rate of C/S=2.1-20.0%FeO was up to 89.2% at 1530-1550oC.
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WANG, MU-GIN, and 王木琴. "A study on crystallization and phase transformation of Li2O-CaO-Al2O3-SiO2 glass-ceramic system." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/65628265453814375094.
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Wong, Pei-Ying, and 翁沛穎. "Effects of Al2O3、TiO2 and ZrO2 additions on microstructures and properties in a low temperature co-fired CaO-Al2O3-B2O3-SiO2 glass." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/bf22w3.
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碩士<br>明志科技大學<br>機械工程系機械與機電工程碩士班<br>104<br>Al2O3, TiO2 and ZrO2 ceramics added in a CaO-Al2O3-B2O3-SiO2 glass system are explored as microwave dielectric materials for the development of low temperature co-fired ceramics (LTCC). A glass frit was synthetized by mixing oxides of the CaO, Al2O3, B2O3, and SiO2 melted at 900°C and then quenched. The grinded glass frits are mixed with 0~30 wt% of Al2O3, TiO2 and ZrO2 ceramic powders. The mixed powders pressed into disks and then sintered at 900°C for 0.5 hr. The microstructural features, microwave dielectric properties, bending strength, density, and coefficient of thermal conductivity are studied. Experimental results show the coexistence of amorphous glasses and crystallization ceramic-fillers. There are no extra second phases in the matrix. The 8-12 wt% additions of Al2O3, TiO2 and ZrO2 display higher densification and lower porosity, which attributed to superior wettability of interface between glass and ceramic-filler due to liquid phase sintering of glass. Moreover, these compositions also exhibit higher bending strength and coefficient of thermal conductivity. The glass added different contents of Al2O3, TiO2 and ZrO2 fillers display a linear increase of dielectric permittivity at a 2.45GHz frequency of measurement. The CaO-Al2O3-B2O3-SiO2 glass with 8-12 wt% additions of Al2O3, TiO2 and ZrO2 can be suggested as a low temperature co-fired microwave dielectric material.
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Lin, Pei-Hsiang, and 林貝香. "Evaluation of MgO-CaO-Al2O3-SiO2-P2O5 Bioglass Immobilized with OMP Peptide as Bone Substitute In vivo." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/07328127080583726539.
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碩士<br>中臺科技大學<br>醫學工程暨材料研究所<br>103<br>The modifications induced on the surfaces of biomaterials aimed at promoting cell growth have been widely studied in the recent years for their potential application in the tissue engineering and regenerative medicine fields. Osteointegration and bone growth can be improved by biomimetic modification achieved by immobilization of selected proteins or peptides on the device surface. Previous studies have suggested that osteopontin play a role in bone resorption, tumorigenesis, and metastasis. In addition, osteopontin contains several interesting structural domains, including RGD (arginine-glycine-aspartic acid) adhesive domain. Therefore, the purpose of our study was to investigate the dose-dependent response and sequence- dependent response of recombinant human osteopontin fragment peptide (contain RGD) enhances osteogenic capability in vivo.
In this study, MgO-CaO-Al2O3-SiO2-P2O5 bioglass (AA) and recombinant human osteopontin fragement peptide (OMP) were manufactured from our lab. and used as raw materials. The covalent immobilization of OMP peptides on AA surface was carried out according to Iucci et al. and designed three different sequences and concentrations of OMP peptide: OMP-Ⅰ (50 μg/ml, OMP-Ⅰ50), OMP-Ⅲ(50 μg/ml, OMP-Ⅲ50), OMP-Ⅲ(250 μg/ml, OMP-Ⅲ250) as biomolecules for biomimetic modification, respectively. For animal study, AA discs immobilized with and without OMP peptides were implanted in the tibia of New Zealand white mature rabbits under general anaesthesia. Each rabbit received 4 implants, 2 in the left tibia and 2 in the right tibia. At the experimental times of 4, 8, and 12 weeks, rabbits were sacrificed, tibias were harvested and surrounding soft tissue was stripped. All the specimens were examined by radiographic, histology and histomorphometry analysis.
According to the macroscopic observation, all bone substitutes show good biocompatibility and no abnormal inflammation either infection was observed at the implantation sites. Radiographic images of implant sites at 4, 8, and 12 weeks showed in all groups that included OMP-immobilized AA substitutes were well incorporated with host bone tissue compared with control groups. In the histological, newly formed bone directly contacts the surface of OMP-immobilized AA substitutes, even growing into the center of material. After 4 weeks of implantation , the amount of newly formed bone by histomorphometrical data was 28.80% in OMP-Ⅲ250, 24.95% in OMP-Ⅲ50, 22.10% in OMP-Ⅰ50 and 18.37% in control group. After 8 weeks of implantation , the percentage of newly bone was 38.84% in OMP-Ⅲ250, 35.13% in OMP-Ⅲ50, 30.03% in OMP-Ⅰ50 and 26.86% in control group. After 12 weeks of implantation , more new bone was increased to 70.19% in OMP-Ⅲ250, 66.28% in OMP-Ⅲ50, 55.68% in OMP-Ⅰ50 and 50.49% in control group. Significant the percentage of newly formed bone in OMP-Ⅲ250 greater than all group in the same period.
Base on above results, we concluded that OMP-immobilized AA bioglass showed well biocompatibility and osteointegration characteristic comparing with AA bioglass. The sequence and concentration increase enhances new bone formation in this study. Therefore, OMP-immobilized AA bioglass could be served as a great bone substitute for the repair of bone defect.
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Baasner, Amrei. "The Influence of Fluorine, Chlorine and Water on the Rheology and Structure of Na2O-CaO-Al2O3-SiO2 Melts." Doctoral thesis, 2013. http://hdl.handle.net/11858/00-1735-0000-0022-5EBF-3.
Full textAbstract:
In dieser Studie wurde der alleinige und gemeinsame Einfluss von 1.6 bis 14.5 mol% Wasser, 1.1 bis 18.3 mol% Fluor (F) und 0.5 bis 1.4 mol% Chlor (Cl) auf die Struktur und Viskosität von peralkalinen und peraluminösen Na2O CaO Al2O3 SiO2 Gläsern und Schmelzen mit ~ 66 mol% SiO2 (auf volatilfreier Basis) untersucht. Die Zusammensetzung der peralkalinen Proben entspricht einem Modellsystem für Phonolithschmelzen. Die wasserfreien Proben wurden in 1 atm Öfen aus Oxid und Karbonatverbindungen sowie Halogeniden hergestellt. Die wasserhaltigen peralkalinen Proben wurden in einer innenbeheizten Gasdruckanlage und die wasserhaltigen peraluminösen Proben in einer Stempelzylinderpresse hergestellt. Die Viskosität der Proben wurde mit der Mikropenetrationstechnik (108.5 1013 Pa s) und der „parallel plate“ Methode (105.5 Pa s 109 Pa s) gemessen. Die Struktur der Gläser wurde mittels „magic angle spinning“ (MAS) Kernspinresonanzspektroskopie (NMR) anhand der Nuklide 19F, 23Na, 27Al, 29Si and 35Cl analysiert.
Fluor und Wasser allein oder in Kombination verringern die Viskosität der Schmelzen, wobei der Effekt von Wasser stärker ist als der von F. Beide Volatile verringern die Viskosität von peraluminösen Schmelzen stärker als in den peralkalinen Schmelzen. Für die peralkalinen Schmelzen wurde eine Verringerung der Viskosität durch F bis zu einer Konzentration von 1.9 mol% F festgestellt, jedoch für eine Konzentration von 6.2 mol% F wurde keine weitere Verringerung der Viskosität festgestellt. In den peraluminösen Schmelzen hingegen wurde bis zu einer Konzentration von 18.3 mol% F ein stetiger Abfall der Viskosität mit zunehmendem Fluorgehalt beobachtet. Der gemeinsame Einfluss von F und Wasser ist auf Grund ihrer jeweiligen Einzeleffekte geringer als angenommen, was zeigt, dass die Effekte von F und Wasser auf die Viskosität nicht unabhängig voneinander sind.
Der zusammensetzungs und konzentrationsabhängige Effekt von F auf die Viskosität der Schmelzen stimmt mit Unterschieden im Einbaumechanismus von F überein. 19F MAS NMR Spektren zeigen, dass in den peralkalinen Gläsern F sowohl in „salzartigen“ F Ca(n) und F Na(n) als auch in nicht brückenbildenden Si F Na(n), Al F Ca(n), Al F Na(n) und brückenbildenden Al F Al Umgebungen vorkommt („n“ bedeutet, dass die Anzahl der Atome unklar oder variabel ist). F Ca(n) ist die am häufigsten vorkommende Umgebung, obwohl Ca das am wenigsten häufige Kation in den Proben ist. In den peraluminösen Gläsern existiert F nur in Si F und Al F Umgebungen, wobei Al F Na(n) die am häufigsten vorkommende Umgebung ist. Die Bildung von salzartigen F Ca(n) und F Na(n) Umgebungen sollte zu einem Anstieg der Viskosität durch eine Verringerung der netzwerkmodifizierenden Kationen führen. Die Bildung von Si F und Al F Umgebungen sollte die Viskosität entweder auf Grund einer Reduzierung von brückenbildenden Sauerstoffen durch nicht brückenbildende F oder durch einen Austausch von brückenbildenden Sauerstoffen durch brückenbildende F, welche eine niedrigere Bindungsstärke haben, verringern. Daraus lässt sich schließen, dass F die Viskosität in peralkalinen Schmelzen weniger stark verringert als in peraluminösen Schmelzen, weil F in den peralkalinen Schmelzen in Umgebungen existiert, welche die Viskosität erhöhen oder erniedrigen können, während F in den peraluminösen Schmelzen nur in Umgebungen existiert, welche die Viskosität verringern.
Der konzentrationsabhängige Einfluss von F auf die Viskosität in den peralkalinen Schmelzen scheint in Zusammenhang mit einer Änderung in der Fluorspeziation zu stehen: Der relative Anteil von F Ca(n) Umgebungen, von denen anzunehmen ist, dass sie die Viskosität erhöhen, steigt von 42 auf 53% bei einem Anstieg im F Gehalt von 1.2 auf 6.2 mol% F. Veränderungen in der Fluorspeziation scheinen ebenfalls verantwortlich dafür zu sein, dass der Effekt von F und Wasser in Kombination geringer ist als erwartet. 19F MAS NMR Spektren von fluor und wasserhaltigen Proben zeigen, dass der relative Anteil von Al F Umgebungen, von denen anzunehmen ist, dass sie die Viskosität verringern, mit zunehmendem Wassergehalt abnimmt und dass im Gegenzug der relative Anteil von F Ca(n) Umgebungen zunimmt. Mit IR Spektroskopie wurde in den peralkalinen Proben kein Unterschied im OH/H2O Verhältnis bei gleichem Gesamtwassergehalt durch die Präsenz von F beobachtet. Im Gegensatz dazu gibt es starke Hinweise darauf, dass F in den peraluminösen Proben das OH/H2O Verhältnis bei gleichem Gesamtwassergehalt verringert, was erklären würde, weshalb F und Wasser in Kombination die Viskosität weniger verringern als von ihren Einzeleffekten zu erwarten wäre.
Der Einfluss von Cl auf die Viskosität und Struktur der Schmelzen und Gläser ist sehr unterschiedlich verglichen mit F. Cl erhöht die Viskosität in den peralkalinen Schmelzen und verringert die Viskosität in den peraluminösen Schmelzen. Viskositätsmessungen von wasserhaltigen, chlorfreien und chlorhaltigen peralkalinen Schmelzen zeigen, dass der Effekt von Cl auf die Viskosität nicht durch die Präsenz von Wasser beeinflusst wird. Das beobachtete 35Cl NMR Signal zeigt, dass sowohl in den peralkalinen als auch in den peraluminösen Gläsern Cl in Na Ca Cl Umgebungen mit einem hohen Na Anteil existiert, was auf Grund des Ca/Na Verhältnisses von 1/5 zu erwarten war. Die Cl Umgebung in den peralkalinen und peraluminösen Gläsern ist ähnlich, jedoch beinhaltet die Cl Umgebung in den peraluminösen Gläsern mehr Ca. In den 35Cl MAS NMR Spektren wurde im Vergleich zu einem Natriumsilikatglas nur ein Teil des 35Cl NMR Signals der peralkalinen und der peraluminösen Proben beobachtet. Das fehlende Signal deutet darauf hin, dass ein Teil der Cl Atome in verzerrten oder ungeordneten Umgebungen existiert, welche eine Signalbreite haben, die zu groß ist, um mit den verwendeten NMR Spektroskopie Methoden gemessen werden zu können. Der Anstieg der Viskosität durch Cl in den peralkalinen Schmelzen kann dadurch erklärt werden, dass Cl die Anzahl der netzwerkmodifizierenden Kationen reduziert, während mehrere Möglichkeiten zur Diskussion stehen, weshalb Cl die Viskosität in peraluminösen Schmelzen verringert.
Die Effekte von F und Cl auf die Viskosität sind unabhängig voneinander und summieren sich auf. Es wurde mit NMR Spektroskopie kein Hinweis dafür gefunden, dass F einen Einfluss auf den Einbaumechanismus von Cl hat.
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Wu, Cheng-Han, and 吳政翰. "Study of Desulfurization Ability and Corrosion of Refractory with Addition of B2O3 and CaF2 into a Desulfurizer of CaO-Al2O3-SiO2 Series." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/99260313171002118115.
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Chung-ChingWang and 王鐘慶. "Effects of Zirconium Oxide Addition on the Crystallization Behavior,Dielectric Properties and Mechanical Properties of the K2O-CaO-MgO-Al2O3-SiO2 Glass Ceramics." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/20976288467830883643.
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Shin, Jin-Wook [Verfasser]. "The experimantal and theoretical determination of the thermodynamic properties of melts and glasses from the system CaO-MgO-Al2O3-SiO2 / vorgelegt von Jin-Wook Shin." 2004. http://d-nb.info/975613715/34.
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SIMONETTI, GIULIA. "Glass ceramics for high-temperature sealing applications: synthesis and physicochemical properties of modified CaO-MgO-Al2O3-SiO2 materials, with a view to recycling of industrial waste." Doctoral thesis, 2018. http://hdl.handle.net/11573/1211859.
Full textAbstract:
Solid Oxide Fuel cells (SOFC) and dense gas separation membranes based on mixed ionic and electronic conductors have gained increased interest the resent years due the search for new technologies for clean energy generation. These technologies can be utilized to produce electricity from fossil fuel with low CO2 emission compared to conventional gas or coal based energy plants. One crucial challenge with SOFCs is the sealing of the active membranes/electrolytes to prevent leakage of air to fuel side or vice versa. Due to the high operating temperatures of typical 600-1000°C the selection of reliable sealing materials is limited. The seals have to remain gas tight during the life time of the reactor/SOFC, they need to be chemical compatible with the sealed materials and stable in reducing and oxidizing atmospheres containing water vapor and CO2, and finally they should be cheap, readily available and easy to process. The main purpose of the present work was to evaluate rigid bonded glass ceramic seals for dense oxygen ion and proton conducting membranes and electrolytes for SOFCs. First, a review of sealing technologies has been carried out with emphasis on SOFC and ceramic membranes technologies applicable for zero emission power plants. Regarding sealing, the best and cheapest materials at the present time are based on silicate glass and glass ceramics.
The aim is to provide a systematic study of the properties of glasses and glass-ceramics as a function of the glass composition in the CaO-MgO-Al2O3-SiO2 system, which represent the most advanced sealing technology for high-temperature Solid Oxide Fuel Cells (SOFC).
Two glass systems have been evaluated, aluminosilicate and boroaluminosilicate and their variants obtained adding five different oxides acting as nucleating agents, like TiO2, MnO2, ZnO and SnO2. Fabrication and characterization of the glasses are reported with special focus on the thermal and thermochanical properties, glass forming ability, kinetic crystallization and phase evaluation. The influence of different additives in glass and glass ceramic properties has been analyze in depth.
In the last section, the research has been extended to the recycling of aluminosilicate basted waste to characterize a new type of glass ceramic derived from industrial waste, like Kaolin clay waste.