La fiabilité des composants électroniques, surtout dans les technologies de pointe, prend de l’ampleur. Cela est notamment motivé par la réduction de volume demandée dans des structures fortement sollicitées et dont la durée de vie exigée peut atteindre plusieurs dizaines d’années. Nous considérons, ici, un substrat électronique. Il sert de support à un circuit d’électronique de puissance. Dans un tel circuit, les composants, comme les puces, s’échauffent. Cette augmentation de température au niveau de la puce se reporte sur le substrat. Il subira d’autre part des variations de températures environnementales, telles que le cycle jour/nuit dans les satellites ou imposée par l’ambiance comme dans un puits de forage. Le substrat utilisé est composé de plusieurs couches de céramique et de pistes de conduction en métal entre et à travers ses couches. Lorsque ces différents matériaux se dilatent, cela induit des concentrations et gradients de contraintes. Ces variations étant sur des grandes durées, elles peuvent mener le substrat à rupture par fatigue. Dans le cadre de cette étude, l’objectif est de comprendre les mécanismes de défaillances qui peuvent mener à rupture et les moyens de les éviter. Nous cherchons à déterminer des règles de conception simples permettant d’éviter ces défaillances, comme la taille et la distance entre les différentes pistes traversant la céramique. C’est grâce à l’application de la mécanique de la rupture sur le substrat et en fonction de l’utilisation décrite précédemment, que nous évaluerons les défaillances critiques. La modélisation mécanique du substrat dégagera ainsi des règles de dimensionnement permettant d’éviter ces défaillances. / The reliability of electronic compound, especially in advanced technologies, is becoming very important. This is motivated by the volume reduction asked in highly loaded structures. Moreover, its required lifetime can be about decades. Here, we have an electronic substrate. A power electronic circuit lays on it. In such circuit, compounds like chip are heating up. This rising of temperature from the chip propagates on the substrate. Furthermore others environmental amplitudes of temperature will be imposed like the day/night cycle for satellites or the rock temperature in well bores. The substrate is composed of several ceramic layers with metal conducting tracks inside and in between. When theses materials dilate it induces stress concentrations and gradients. Since theses changes are occuring on important durations, they cans lead the substrate to a fatigue failure. The point of this study is to understand the failure mechanisms leading to break and the means to avoid them. Then we seek to determine simple conception rules such as the size and the gap between different tracks going through the ceramic. Thanks to the use of the fracture mechanics on the substrate and according to the previously described use, we will evaluate the critical failures. Thus, the mechanical modelling of the substrate will generate some rules for the dimensions.

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High Efficiency Particulate Air (HEPA) filters are defined as extended-medium, dry-type filters with: (1) a minimum particle removal efficiency of no less than 99.97 percent for 0.3 micrometer particles, (2) a maximum, clean resistance of 1.0 inch water column (in. WC) when operated at 1,000 cubic feet per minute (CFM), and (3) a rigid casing that extends the full depth of the medium. Specifically, ceramic media HEPA filters provide better performance at elevated temperatures, are moisture resistant and nonflammable, can perform their function if wetted and exposed to greater pressures, and can be cleaned and reused. This paper describes the modification and design of a large scale test stand which properly evaluates the filtration characteristics of a range of ceramic media filters challenged with a nuclear aerosol agent in order to develop Section FO of ASME AG-1.

The built environment has largely separated itself from the natural one, making demands of nature, and requiring the natural environment to exist on its terms. This prevailing condition has led to the detriment of the natural environment and consequently, those who must inhabit both. Because of this, a shift from the domination of the natural environment to reconciliation with it is necessary. Serving as an intermediary between these two worlds, architecture has the potential to blur the boundaries once created by the built environment in the pursuit of reconciliation. Architecture can learn from the natural environment and take that which has been poorly adapted to aim for a more synchronous future. Shaping culture and perspective, architecture can serve as a signal to humanity that this reconciliation is worth pursuing. This thesis explores the dialogue between form and facade to comment on architecture's flawed yet hopeful path as it seeks a more sustainable relationship with nature. / Master of Architecture / The facade acts as an element of nature, attaching itself to the building like a mask as if it were nature itself taking over the building. Composed of coral-inspired ceramic pieces, the facade hosts an alternative green wall of algae. An otherwise typical rectilinear building form transforms itself, stretching certain spaces beyond its bounds to reach out to the facade as if a reconciliation is desired. This thesis explores the dialogue between form and facade to comment on architecture's flawed yet hopeful path as it seeks a more sustainable relationship with nature.

This thesis paper supports the Master of Fine Arts exhibition at the Tipton Gallery, East Tennessee State University, from January 28th through February 8th, 2013. The exhibit is comprised of two hundred fifty-three porcelain objects and lines created with naturally colored porcelain slips used as paint. SURFACE presents my exploration of the natural world; the experiences and memories created during this process compelled this exhibition. Topics discussed are the influences, concepts, techniques, and methods used to create the work. Included are process images, detail images, and images of selected works from the exhibition.

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The ZEBRA battery based on Na/NiCb chemistry shows promise for powering electric vehicles and load leveling systems. The ZEBRA cell consists of a liquid sodium negative electrode separated from the positive electrode by a W'-alumina solid electrolyte. The current state of development of this battery makes use of glass sealing and thermo compression sealing as an integral part of the cell assembly. One objective of the present research was to reduce the thickness of the W'alumina electrolyte thickness as a means to improve perfomance, by lowering the internal cell resistance. The second objective was to develop a ceramic seal with matching thermal expansion coefficient (TEC) to increase battery durability. An added benefit realized with the new ceramic seal was its use for high temperature applications such as emf measurements ordinary systems to determine thermodynamic properties. Dense electrolyte tubes with reduced thickness of less than 100 J..Lm and supported on a porous substrate were successfully produced by slip casting. The slip casting parameters, sintering conditions and materials were optimized and electrolyte resistance was measured by a DC method. A ceramic seal was developed from a eutectic mixture of Na20 and Al203 and tested in galvanic cells. The reproducibility of the emf data shows that the seal is fully impervious and can sustain a high alkali pressure atmosphere up to 1 000°C without cracking or degradation. The seal microstructure revealed liquid phase formation of the seal and diffusion bonding with the lid and tube. The thermodynamic properties and phase relations of the Na-Si binary system were studied by the emf method using Na|β-alumina|Si-Na galvanic cells over the whole composition range below 600°C. There is very limited solubility of Si in molten Na. Properties of the sodium silicon compounds were determined from the emf measurements. / Thesis / Doctor of Philosophy (PhD)