This prodrome sought to define through research, the material. composition, historic foundations, significance and technical development of glass as a window-glazing material for ecclesiastical, and later secular purposes, and examining thus its determining role in the development of architecture. The history and techniques of stained glass, an art-form linked more than any other to the mythology and dogma of the Roman Catholic Church, were traced; its history is thus one with that of the church, rising to its greatest glory during the twelfth and thirteenth centuries, and declining from the late fifteenth to the seventeenth centuries. The iconography of the church was examined, and the development of window and tracery types discussed through reference to pertinent examples on both sides of the English Channel. Subjects, stylistic and technical factors, sources of reference, ecclesiastical influences, were all within the context of social and political history . viewed. Intro., p. 1-2.

The thesis named Analysis of Czech export development in chosen field - glass industry, jewellery glass describes a development of glass and ceramics industry in Czech lands and in the Czech Republic. The aim of the thesis is to analyze export development of glass and ceramics products, mainly in the 21st century. Conclusions are based on data of Harmonized System from the Czech Statistical Office. It is clear that the importance of export of glass, jewellery and ceramics is not as high as it used to be before WWII, however, the value of export increased in 2010. The future of the Czech glass-work is represented by orientation to technologically sophisticated products which cannot be easily produced on the cheap Asian markets.

Orientadores: Carlos Kenichi Suzuki, Jacinta Enzweiler / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-24T12:58:32Z (GMT). No. of bitstreams: 1 Santos_MuriloFerreiraMarquesdos_M.pdf: 35876462 bytes, checksum: 9ccb2d6d6d03821c52795bf16da4325e (MD5) Previous issue date: 2014 / Resumo: Este trabalho foi conduzido com base em avaliar o potencial de jazidas de quartzo localizadas no Brasil para a utilização na fabricação de sílica vítrea para as indústrias de alta tecnologia (principalmente focando a manufatura de utensílios para a purificação e processamento de silício e de vidro óptico transparente no UV). As jazidas foram escolhidas conforme sua importância econômica no passado, seus níveis de produção, sua pureza química e a disponibilidade de minério. Elas foram avaliadas quanto à sua geologia, composição química (pela técnica de ICP-MS) e comportamento quando submetidas à fusão em sílica vítrea. Para esta fusão duas técnicas foram utilizadas, a técnica de Verneuil e a fusão em plasma pulsado (Spark Plasma Sintering). Os vidros fundidos com o material de cada jazida foram caracterizados quanto à transmitância óptica no visível e no UV. O trabalho também buscou identificar qual seria a melhor maneira de processar industrialmente o mineral proveniente de cada jazida. Os resultados obtidos mostram que várias jazidas são capazes de produzir vidros de alta qualidade, em especial aqueles provenientes de amostras da formação Serra de Santa Helena, localizada no norte do Estado de Minas Gerais e de Brotas de Macaúbas, no Estado da Bahia. Outras jazidas localizadas no Estado da Bahia também se mostraram alternativas economicamente viáveis / Abstract: This work aimed to evaluate the use of Brazilian quartz in the manufacture of silica glass for high tech industries (specially focused in the production of quartz crucibles for the high purity silicon industry and in the production of optical glass transparent to UV radiation). The mines which were studied here were selected according to its economic importance in the past, its production levels, its chemical purity and the amount of mineral contained in it. All mines were evaluated according to its geology, its chemistry (using the ICP-MS technique), and its behavior during fusion. In order to conduct this fusion, two different fusion techniques were used: Verneuil method, for flame fusion, and Spark Plasma Sintering (SPS) for electrical fusion. After fusion, each glass was evaluated according to its optical transmittance. It was also proposed some ways of industrially processing the minerals in order to obtain a better powder for fusion. Obtained results show that Brazilian mines are highly capable of producing good quality glasses using simple processing methods. The work emphasize the quality of the minerals original from the Santa Helena Formation, in northern Minas Gerais State, and from Brotas de Macaúbas, in the State of Bahia. Other minerals from the state of Bahia might also be a viable alternative / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Indiana University-Purdue University Indianapolis (IUPUI) / Observations of heterogeneities in Earth’s mantle motivate studies of mantle phase assemblages with variable composition. As samples cannot be directly collected from these regions, synthetic glasses can act as analogues for mantle melt and starting materials for high-pressure synthesis of stable mantle minerals in experiments. Here, I develop a specific methodology to produce homogeneous glasses that accurately span the composition space from enstatite (MgSiO3) to forsterite (Mg2SiO4), as well as Fe-bearing enstatite ((Mg0.1Fe0.9)SiO3 and ((Mg0.95Fe0.05)(Si0.95Fe0.05)O3) with variable oxidation states. This study systematically tests and iterates upon glass synthesis methods using an aerodynamic levitation laser furnace, in which a spherical glass sample levitates on a gas stream flowing vertically through a conical nozzle, while being heated from above with a 400 W CO2 laser. With sample diameters of 0.6-2.0 mm, shutting off the laser results in supercooling of levitated spheres at rates between 350 and 1350 °C/s. Sample preparation begins with grinding and mixing pure oxide powders in an agate mortar and pestle, followed by heating in a high temperature oven to devolatilize the mixture. Powders (0.5-7 mg aliquots) are fused into spheres in a copper hearth plate. To tune Fe valency and vitrify each sphere, samples are then levitated on flows of Ar, O2, 5% CO in Ar, 5% CO2 in Ar, or combinations of two of these gases, while being heated with the laser to temperatures above the liquidus for each composition for ~10 s before quenching. After x-ray diffraction (XRD) analyses confirm vitrification, a dual polish is applied, exposing parallel flat polished surfaces for scanning electron microscope (SEM) and electron probe microanalyzer analyses (EPMA). Back-scattered electron images and energy-dispersive x-ray spectroscopy (EDS) analyses of the spheres are obtained first on the SEM to gauge compositional accuracy and homogeneity, then EPMA analyses determine quantitatively the samples’ compositions. Once fully characterized, these glasses can be used in diamond anvil cell experiments, where they can act as proxies for an otherwise inaccessible area of the Earth. In addition to the development of this methodology, two web applications produced during this research aid in visualization of both data logs and analytical results.

No description available.

The research presented in this thesis focusses on the experimental study of two fundamental questions: the crystal-to-glass transition and how aggregates of adhesive droplets spread on a surface. Aggregates made of lightly adhesive oil droplets are used as models for crystals or amorphous glasses. The force applied on the aggregates can be directly measured as they are compressed. A large portion of the work focusses on the crystal-to-glass transition and tries to answer the following question: how many defects are needed in a crystal for its mechanical response to be like a glass? To answer this question, the mechanical response of a perfect mono-crystal is measured. It is found that crystals deform elastically until they fail catastrophically in a single event once the force exceeds a critical value: the yield stress. The force measured during the compression of a crystal shows a well defined number of peaks which only depends on the initial geometry of the aggregate. As defects are added (the amount of disorder increased) the number of peaks in the force measurement increases rapidly before it saturates at a value obtained for model glasses. The magnitude of the force peaks also decreases as disorder is introduced. This work concludes that even a small amount of disorder in a crystal has a significant impact on its mechanical properties. In the second project, the spreading of a monodisperse aggregate of oil droplets is studied. Droplets are added one-by-one to a growing aggregate and the area covered on the interface is measured. It is found that after an initial 3D growth, the height of the aggregate saturates and the growth only happens in 2D along the horizontal direction. The growth is analogous to a puddle of liquid. In analogy with the capillary length in liquids, the ``granular capillary length" is introduced to characterize the balance between buoyancy acting on the droplets and the adhesion strength. The height of the aggregates, in the later stage of the growth, is set by this length scale. A method was developed to characterize the adhesion between two droplets, a key parameter in this experiment, as a function of the relevant experimental parameters. / Thesis / Doctor of Philosophy (PhD)

Indiana University-Purdue University Indianapolis (IUPUI) / The functional quaternary ammonium salts (QAS) and their constructed polyQAS or PQAS were synthesized, characterized and formulated into a novel antibacterial glass-ionomer cement. Compressive strength (CS) and Streptococcus mutans (S. mutans) viability were used to evaluate the mechanical strength and antibacterial activity of the cements. Fuji II LC cement was used as control. The specimens were conditioned in distilled water at 37 oC for 24 h prior to testing. The effects of the substitute chain length, loading as well as grafting ratio of the QAS and aging on CS and S. mutans viability were investigated. Chapter 2 describes how we studied and evaluated the formulated antibacterial glass-ionomer cement by incorporating QAS chloride-containing polymer into the formulation. The results show that with PQAS addition, the studied cements showed a reduction in CS with 25-95% for Fuji II LC and 13-78% for the experimental cement and a reduction in S. mutans viability with 40-79% for Fuji II LC and 40-91% for the experimental cement. The experimental cement showed less CS reduction and higher antibacterial activity as compared to Fuji II LC. The long-term aging study indicates that the cements are permanently antibacterial with no PQAS leaching. Chapter 3 describes how we studied and evaluated the formulated antibacterial cements by changing chain length, type of halide, loading, grafting ratio and aging time. The results show that the effects of the chain length, loading and grafting ratio of the QAS were significant. Increasing chain length, loading, grafting ratio significantly enhanced antibacterial activity but reduced CS. The experimental cement showed less CS reduction and higher antibacterial activity as compared to Fuji II LC. The long-term aging study indicates that the cements are permanently antibacterial with no PQAS leaching. There was no significant difference between QAS bromide and QAS chloride, suggesting that we can use QAS bromide directly without converting bromide to chloride. In summary, we have developed a novel PQAS-containing antibacterial glass-ionomer cement. The cement has demonstrated significant antibacterial activities. Our experimental cement is a promising system because the reduced strength of the cement with addition of PQAS is still above those demonstrated by original commercial cement Fuji II LC without any PQAS addition. It appears that the experimental cement is a clinically attractive dental restorative that can be potentially used for long-lasting restorations due to its high mechanical strength and permanent antibacterial function.

Silicate glasses are the most common glass types and have impact on almost every aspect in our lives: from window, containers, to glass fibers for telecommunications. Unlike their crystalline counterparts, glass materials lack long-range order in their atomic arrangement but their structures do possess short and medium range characteristics that play critical roles in their physical and chemical properties. Despite active development of characterization techniques that have contributed to the understanding of glass structures, there remain key challenges in obtaining essential structural features of glasses. Atomistic computer simulations have become an increasingly important method in elucidating the atomic structures and in interpretation and/or prediction of composition-structure-property relationships of complex materials. In this dissertation, classical molecular dynamic (MD) simulations were used to investigate the atomic structures, dynamic and other properties of two important glass systems—aluminosilicate glasses and borosilicate glasses, which are the basis of most industrial and technologically important glasses. Firstly, a comprehensive study of peralkaline Na2O-Al2O3-SiO2 glass with varying Al2O3/SiO2, Na2O/Al2O3, Na2O/SiO2 ratios has been performed to obtain better understanding of the composition–structure–property relationships in this glass system. More than 99% of Al were 4-coordinated in these glasses, validating that Na+ tend to charge balance [AlO4]- network forming units first and then, excess Na+ was used to create non-bridging oxygen (NBO) on Si. As the drop of Na/Al ratio, the percentage of NBO decreases, indicating an increase of the glass network connectivity. In addition, polyhedral connection probability results show that Al tend to be randomly distributed in the glass structure, suggesting a violation of Lowenstein's rule. These structural properties were further used to explain macroscopic properties of glass, such as change of glass transition temperature (Tg) and hardness (Hv) with glass composition. Secondly, molecular dynamics simulations were used to understand the structural, thermal mechanical and diffusion behaviors of spodumene (LiAlSi2O6) crystalline phases and glasses. It was found that β-LiAlSi2O6 has a structure much closer to the glass phase. The α-LiAlSi2O6 phase, however, has a more closed-packed structure and higher density. The diffusion behaviors were also found to be closely related to the atomic structures. Thirdly, the surface atomic structures of a series of sodium borosilicate glasses were studied using recently developed compositional dependent partial charge potentials. This provides insight into: a) the structural difference between glass surface and bulk glass; b) the evolution of bulk and surface structures as the change of glass composition. Lastly, pressure and temperature effects on the structure and properties of borosilicate glass were investigated in detail. A serial data derived from different compression temperatures and pressures enable us to explore the link between the microstructure and macroscopic physical properties. The results show that compression temperature and pressure play important roles in glass densification process and may result various glass densification mechanism. This dissertation demonstrates that atomistic simulations coupled with effective potentials and careful validations have become an effective method in research and design of complex glass materials.

No description available.

No description available.