Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"Glass Structure"”.
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High-Resolution Solid-State Silicon-29 Nuclear Magnetic Resonance Studies of Minerals and Glasses (Nmr, Aluminum, Silicates, Structure)
… sample spinning studies of minerals and glasses are a useful tool in the effort to understand more about mineral and glass structure.
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The effect of composition on the viscosity, crystallization and dissolution of simple borate glasses and compositional design of borate based bioactive glasses
<p>"Borate glasses have recently been developed for a variety of medical applications, but much less is known about their structures and properties than more common silicate glasses. Melt properties and crystallization tendency for compositions in the Na<sub>2</sub>O-CaO-B<sub>2</sub>O<sub>3</sub> …
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The effect of intense x-ray beams on oxide glasses unveiled by means of photon correlation spectroscopy
… under x-ray illumination in a selection of oxide glass formers as a function of the radiation dose. The irradiated specimens are investigated by means of XPCS experiments and also by means of “exsitu” experiments as luminescence, Raman and x-ray diffraction that have been carried out after the …
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Deformation Localization in Constrained Layers of Metallic Glasses: A Parametric Modeling Analysis
… shear banding is a prominent feature in metallic glasses. In this study we perform parametric three-dimensional finite ele- ment analyses, using primarily a thin layer of metallic glass on top of a cylindrical base, to study how physical constraint can affect this localized form of deformation and …
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Women and trousers : being a work on dual garnitures and a case study of the bifurcated movement in nineteenth-century clothing for women in North America
… (1843), and Joseph Paxton's Crystal Palace, a glass structure designed for the Great Exhibition of the Industries of All Nations of 1851 in London, England. Contrary to many modern accounts, archival evidence shows that once the concept of a trousered costume for women was introduced in North …
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Investigation of the non-Arrhenius behavior of fast ion conducting glasses
<p>Traditional glassy ion conductors exhibit Arrhenius temperature dependence of the d.c. conductivity. Recently, Kinc and Martin1 reported the discovery of a Fast Ion Conducting (FIC) glass with ionic conductivities as high as 10-2 (O-cm)-1. Surprisingly, while this is a very high conductivity for …
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Investigation of the thermodynamics of iron phosphate melts and stability of iron phosphate glasses: effects of composition and iron redox ratio
“Iron phosphate glasses with Fe/P = 0.33 - 0.67, O/P = 3.0 - 3.5 and Fe<sup>2+</sup>/ΣFe = 0.16- 0.52 were prepared by altering batch compositions and melt conditions. Thermal analyses indicate polyphosphate glasses with intermediate chain lengths are most stable against devitrification. …
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Raman Spectroscopy Of Glasseswith High And Broad Raman Gain In The Boson Peak Region
This thesis investigates Raman spectra of novel glasses and their correlation with structure for Raman gain applications. Raman gain for all-optical amplification by fibers depends significantly on the cross section for spontaneous Raman scattering allowing to compare signal strength and spectral …
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Modification and processing of glass and glass with embedded silver nanoparticles
Glass is an inexpensive and readily available material making it an indispensable element in the many fields of science and technology. This thesis describes three methods of manipulating the optical and structural properties of glass and nanocomposite glass for varying applications. These are: …
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Pulsed laser deposition of chalcogenide glass materials for potential waveguide laser applications
… are able to grow thin films of the chalcogenide glass; gallium-lanthanum-sulphide, gallium-sodium-sulphide and variations of oxysulphides, on a variety of substrates. EXAFS measurements have shown that some of the elements in the glass structure change their bonding arrangement when grown at …
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Towards a new transparency : high fidelity additive manufacturing of transparent glass structures across scales
Optically transparent and structurally sound, glass has played a significant role in the evolution of product and architectural design across scales and disciplines, and throughout the ages. Glass processing methods - such as blowing, pressing, and forming - have aimed at achieving increased glass …
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Mechanisms and Implementation of Thermo-Optical Annealing in Silica Fiber Sensors for Radiation-Induced Attenuation Mitigation
… point defects form within the silica glass structure, reducing the longevity and effectiveness of these sensors. In this work, we investigate the underlying microscopic defects and mechanisms of RIA and assess strategies for mitigation, namely, annealing via heat treatment (thermal …
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Multiplicity of Experiences
… distinct architectural forms — a robust brick structure and its transparent steel and glass counterpart — through strategic cuts that foster gathering and community interaction. The manipulation of light at varying intensities becomes the silent choreographer of space, delineating zones of …
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Investigating the effects of magnesium on the structure and durability of radioactive waste glasses by solid-state NMR
Radioactive waste glasses containing Mg have been shown to have much poorer (~one order of magnitude) aqueous durability in long-term, compared with those have a similar amount of Ca as the alkaline-earth constituent. This is the case between two non-radioactive research surrogates: MW glasses …
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Evolution of the structure and properties of thermomechanically-processed metallic glasses
Metallic glasses (MGs) can assume a remarkably wide range of structures and properties depending on their thermal and processing histories. Increasing the MGs’ enthalpies through thermomechanical processing, a process typically termed rejuvenation, can provide large improvements in mechanical …
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Temperature Dependent Behavior of Optical Loss from Hydrogen Species in Optical Fibers at High Temperature
… the 2200 nm band does not change. Changes in the structure of the glass appear to be causing this temperature dependent behavior. Other necessary conditions for structural changes to cause this temperature dependent behavior are examined.
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Luminescent solar concentrator structures for solar energy harvesting and radiation control
… luminescent solar concentrator (LSC) structures capable of passing most of the visible light through to provide illumination, while reflecting more than 90% of the UV and IR radiations and scattering them to the edges of the glass where they are collected by PV cells to produce …
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An Addition to the Virginia Tech School of Architecture
… campus. Cowgill Hall is a 4 story concrete and glass structure, built in 1969, with a dry moat-like hardscape on three sides around it and a wide bridge connecting the building at the second level to the campus via a large plaza. My solution was to use the bridge as the way to connect an …
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A Study of Boundaries and Transitions
This thesis explores the boundaries and transitions within architecture. What makes a solid boundary? And what blurs the lines of transition in between? Possibilities were explored and limits pushed through the studying of elements such as thickness, transparency, material, texture, and light. The …