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In Andean South America, archaeological research demonstrates that rituals surrounding the consumption of food and drink have long played an important part in building relationships between individuals, families, and communities. This thesis focuses on foodways in the Late Formative (200BC-AD475) and Tiwanaku (475-1000AD) phases of the Lake Titicaca basin in highland Bolivia. I pair ceramic and botanical datasets from three assemblages: Late Formative contexts from Kala Uyuni (southern Titicaca Basin) and Challapata (eastern Titicaca Basin), and a Tiwanaku phase burial at Chiripa (southern Titicaca Basin). The goals of this thesis are to: identify microbotanical plant remains of foods associated with ceramic vessels, consider how these inform archaeological understandings of Titicaca Basin foodways, and evaluate whether studying plant residues from ceramic vessels is an effective method to study foodways. Phytoliths and starch grains recovered from Challapata and Chiripa included remains of both local and non-local plants, while the Chiripa ceramic assemblage included non-local ceramic styles. These results offer new evidence for exchange between highland and lowland sites. Both local and non-local plant remains were recovered in public spaces where ceremonies may have taken place. While non-local goods may have been desirable and special because they were difficult to obtain, results of this thesis suggest that local plants may have been just as symbolically important. Overall, results indicate that pairing ceramic and botanical datasets can enable a richer understanding of foodways. / Thesis / Master of Arts (MA)

The compressive creep behaviour of a high purity silicon nitride ceramic with and without the addition of Ba was studied at 1400°C. Two distinct creep stages were observed during high temperature deformation of these materials. The stress exponents for creep of the two materials indicate that they have different creep mechanisms during the second stage of creep. Cavitation during creep was determined by measuring the density change before and after creep using a water­-displacement method. The Ba doped material exhibited an obvious density decrease, indicating cavitation during creep, whereas the undoped material exhibited no cavitation. This is consistent with TEM observations. The microstructure of the materials, especially the amorphous grain-boundary phase was investigated for both as-sintered and crept specimans by means of transmission electron microscopy (TEM). Statistical analysis of a number of grain-­boundary films indicates that the film thickness is confined to a narrow range (standard deviation less than 0.15 nm) in the as-sintered materials. The average film thickness depends on film chemistry, increasing from 1.0 nm to 1.4 nm when Ba is added. The standard deviation of the film thickness of a given material after creep, however, is considerably larger than before (0.30 nm ~ 0.59 nm). This suggests that the grain-boundary glass phase is redistributed during creep. Viscous flow of the glass phase is proposed as die mechanism responsible for the first stage of creep. The data are compared with a model for viscous creep, yielding good correlation. / Thesis / Master of Engineering (ME)

The thermal diffusivity and conductivity of several ceramic composites were determined experimentally to observe the effect of temperature, heat treatment and orientation on these properties. The thermal conductivity and diffusivity of SiC whisker reinforced Ba-osumilite glass-ceramic exceeded that of SiC fiber reinforced osumilite due to higher thermal conductivity and diffusivity of the whiskers. An anisotropy was observed in thermal conductivity of the whisker composite due to whisker orientation normal to hot-pressing direction. Thermal conductivity of carbon fiber reinforced borosilicate glass parallel to the fiber plane was about twice that of the normal orientation and of the matrix. Heating the composite to above 600°C resulted in permanent decrease in thermal conductivity due to void formation by relaxation of the elastically bent fibers by viscous flow of the matrix. Thermal conductivity of iniaxial carbon fiber reinforced lithia-aluminosilicate glass-ceramic was over ten times higher parallel to the fibers than perpendicular. Permanent decrease of thermal conductivity normal to the fibers was due to matrix cracking caused by relief of internal stresses due to matrix crystallization and thermal gradients during fabrication. Modification of the original theories of Maxwell and Rayleigh permitted derivation of expressions for thermal conductivity of composites of a continuous matrix with dilute concentrations of spherical and cylindrical geometries and of parallel flat plates with thermal resistance at the interfaces. / M.S.

Polymer Derived Ceramics are a promising class of Materials that allow for higher levels of tunability and shaping that traditional sintering methods do not allow for. Polysiloxanes are commonly used as a precursor for these types of material because of their highly tunable microstructures by adjusting the side groups on the initial polymer. These Polymers are generally cross linked and pyrolyzed in inert atmospheres to form the final polymer. The microstructures of Polymer Derived Ceramics is complex and hard to observe due to the size of each microstructure region and the proximity in the periodic table that the elements present have. The process of forming phases such as Graphitic Carbon, Amorphous Carbon, Silicon Carbide. Silicon Oxide, and SiliconOxycarbide are not well understood. Simulation provides a route to understanding the phenomenon behind these phase formations. Specifically, Molecular dynamics simulation paired with the Reaxff forcefield provides a framework to simulate the complex processes involved in pyrolysis such as chemical reactions and a combination of thermodynamic and kinetic interactions. This Thesis examines firstly the size effect that a system can have on phase separation and the change in composition. Showing that size plays a major role in how the system develops and limits the occurrence of specific reactions. Secondly, this thesis shows that using polymer precursors with different initial polymer components leads to vastly different microstructures and yield. This provides insights into how the transition from polymer to ceramic takes place on a molecular level. / Master of Science / Ceramics and Polymers are seen all around the world. Polymers are used in many things from grocery bags to high performance panels on airplanes. Polymers are generally cheap to produce and can be molded into a variety of shapes. Ceramics are generally hard materials and are also used in a wide variety of situations from the concrete in buildings to coatings that protect turbine blades. Ceramics tend to be harder to form specific shapes and more costly to machine. Polymer derived polysiloxanes address this problem by being formed in the polymer state and then transformed into a ceramic by being heated in inert atmospheres. The process of the heating is very complex and the effect that different polymers have on the atomic level is not well understood. This thesis works to address this by using simulation to see what cannot be seen through experimentation alone.

The purpose of the present investigation was to undertake a systematic study of cordierite compositions to determine to what extent the ultimate refractoriness and use temperature could be increased by the addition of zirconia without increasing the thermal expansion above 4.0 x 10⁻⁶ cm./cm./°c. A procedure has been presented for making the compound cordierite. Several raw batch compositions which can be expected to produce a high percentage of relatively pure cordierite on a one-fire basis are given. Data are presented tabulating the coefficients of thermal expansion of cordierite specimens containing increasing percentages of zirconia, the thermal shock resistance of these same specimens, the pyrometric cone equivalents of those specimens which possessed expansions lower than 4.0 x 10⁻⁶, and the effect of firing temperature on the absorption and distortion of a specimen possessing the maximum allowable thermal expansion. The results of the investigation indicate that zirconia does not materially extend the short firing range of cordierite compositions and the refractoriness of cordierite is not increased by the addition of zirconia at least in amounts up to 40%. It was found that a 70% cordierite-30% zirconia body could be used at a temperature of 1300°c without warping or undergoing shrinkage. / Master of Science