Chiapa de Corzo Mound 3 was excavated by Tim Tucker under the direction of the New World Archaeological Foundation in July 1965. Mound 3 is located in the ritual center of Chiapa de Corzo, the southwest quadrant. Significant Preclassic and Protoclassic architecture, burials, and caches were discovered there but were never fully analyzed or published. A complete analysis of this mound is necessary to better understand the role of Chiapa de Corzo as a whole and as a regional power. This thesis completes the analysis and accomplishes the following goals: (1) completes the ceramic analysis and classification started by Tucker, (2) produces a catalog of all the burials and caches and their furniture found in Mound 3, and (3) describes changes in the architecture of this mound for each construction phase to determine the general function of Mound 3 throughout its occupation. Keywords:

Art, process, and materials offer me an escape from the sometimes-crushing realities of my personal struggle with chronic mental illness. Escape is often my primary motivator for making art. However, personal meaning and understanding sometimes come while I'm working in the studio. Sometimes the meanings of the work only become clear years later. Personal experience and experimenting with materials and processes have led me to an appreciation and awareness of entropy--the second law of thermodynamics. My sculptures use spontaneity, abstraction, and process to dialogue with entropy.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1991. / Includes bibliographical references. / Raymond Chi Hing Chiu. / Ph.D.

EFFECTS OF ETCHING DURATION ON THE SURFACE ROUGHNESS, SURFACE LOSS, FLEXURAL STRENGTH OF E.MAX CAD GLASS CERAMIC AND SHEAR BOND STRENGTH TO A RESIN CEMENT Background: Long-term retention of ceramic restorations is dependent on the bond strength of the luting resin to both the tooth and porcelain substrates. In order to achieve successful bonding, the surface of the porcelain substrate must be modified to increase the surface roughness, and this can be achieved chemically by hydrofluoric (HF) acid etching. However, prolonged HF acid etching has shown to have a weakening effect on the evaluated lithium disilicate glass-ceramics. Therefore, it is essential to quantify the required etching duration of HF acid to minimize the possible deleterious effects on ceramic strength while maximizing the bond strength to tooth structure. Objectives: To evaluate the effects of HF acid etching duration on the surface roughness, surface loss, flexural strength, and shear bond strength of IPS e.max CAD (Ivoclar Vivadent) lithium disilicate-based glass ceramic to a resin cement. Hypothesis: The differences in HF acid etching durations will not have a significant effect on the surface roughness, surface loss, flexural strength, or shear bond strength of IPS e.max CAD to a resin cement. Methods: 168 specimens were prepared from IPS e.max CAD blocks. All specimens were polished and sonically cleaned in distilled water. Specimens were fired in the vacuum pump furnace according to the manufacturer’s instructions. Specimens were then divided into 4 groups, according to etching durations, then further divided into 3 subgroups, according to the properties tested. Group A was not etched (control), Groups B, C and D were etched with 5-percent HF acid (IPS Ceramic Etching gel, Ivoclar Vivadent) for 20 s, 60 s and 90 s respectively. The morphologies of both etched and non-etched surfaces in specimens of subgroup 1 of each etching group (n = 16/group) were observed under scanning electron microscopy (SEM). In addition, non-contact surface profilometry (Proscan 2000) was used to calculate the surface loss and to examine the surface roughness of the etched ceramic surfaces and roughness values (Ra, Rq) were documented for each group. Furthermore, etched specimens of subgroup 2 (n = 16/group) were silanated (Monobond Plus, Ivoclar Vivadent) and cemented with a resin cement (Multilink Automix, Ivoclar Vivadent). The shear bond strength (SBS) was measured using a universal mechanical testing machine. For each etching group, subgroup 3 specimens (n = 10/group) were loaded to failure in a three-point bending test to measure their flexural strength values using a universal mechanical testing machine. Data for surface roughness, surface loss, and flexural strength were analyzed using one-way analysis of variance (ANOVA), to identify the significant effects of different HF acid etching durations. Data for shear bond strength test were analyzed using two-way ANOVA to test the effects of etching duration, storage for 24 hours/thermocycling, and their interaction. All pair-wise comparisons from ANOVA analysis were made using Fisher’s Protected Least Significant Differences to control the overall significance level at 5 percent. Results: Difference in HF etching durations did not have a significant effect on surface roughness values Ra or Rq (p = 0.3408; p = 0.3245) respectively, but had a significant effect on surface loss (p = 0.0006). SBS values were not significantly different between experimental groups (p = 0.4650); however, SBS values after 24-h storage were significantly higher than that found after thermocycling (p = 0.0166) among different etching durations. Finally, different HF etching durations did not have a significant effect on flexural strength values (p = 0.1260). Conclusion: Within the limitations of this study, different HF etching durations did not have a significant effect on surface roughness, flexural strength, or shear bond strength of IPS e.max CAD. However, the different etching durations significantly affected the surface loss of the lithium disilicate glass ceramics.

Indiana University-Purdue University Indianapolis (IUPUI) / Ceramics have been extensively used in aerospace, automotive, medical, and energy industries due to their unique combination of mechanical, thermal, and chemical properties. The objective of this thesis is to develop an extrusion based ceramic 3D printing process to digitally produce a casting mold. To achieve the objective, an in-house designed ceramic 3D printer was developed by converting a filament based plastic 3D printer. For mold making applications, zircon was selected because it is an ultra-high temperature ceramic with high toughness and good refractory properties. Additionally, alumina, bioglass, and zirconia slurries were formulated and used as the feedstock material for the ceramic 3D printer. The developed 3D printing system was used to demonstrate successful printing of special feature parts such as thin-walled high aspect ratio structures and biomimetically inspired complex structures. Also, proof of concept with regard to the application of 3D printing for producing zircon molds and casting of metal parts was also successfully demonstrated. To characterize the printed parts, microhardness test, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses were conducted. The zircon samples showed an increase in hardness value with an initial increase in heat treatment temperature followed by a drop due to the development of porosity in the microstructure, caused by the decomposition of the binder. The peak hardness value for zircon was observed to be 101±10 HV0.2. Similarly, the microhardness values of the other 3D printed ceramic specimens were observed to increase from 37±3 to 112±5 HV0.2 for alumina, 23±5 to 35±1 HV0.2 for bioglass, and 22±5 to 31±3 HV0.2 for zirconia, before and after the heat-treatment process, respectively. Finally, a system model for the ceramic 3D printing system was developed through the application of the model-based systems engineering (MBSE) approach using the MagicGrid framework. Through the system engineering effort, a logical level solution architecture was modeled, which captured the different system requirements, the system behaviors, and the system functionalities. Also, a traceability matrix for the system from a very abstract logical level to the definition of physical requirements for the subsystems was demonstrated.

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Native Americans from the middle Connecticut River Valley of New England experienced massive social disruptions during the seventeenth century due to European settlement, but not much is known about their cultural continuities and/or discontinuities during this dynamic period. As an additive technology, ceramics embody the technical choices of potters made at the time of manufacture thus enabling the study of the effect, if any, of colonialism on indigenous material culture and practices in New England. This study examines ceramic assemblages from one Late Woodland period site and one seventeenth-century site in Deerfield, Massachusetts to explore the extent to which ceramics can demonstrate continuities and/or changes in traditional ceramic manufacturing practices in response and/or resistance to colonization.

This study, "Surface Textures of Unglazed Pottery," will record and evaluate a series of experiments performed that can be achieved on unglazed ceramic ware....The problem will be limited to experiments using a red clay from Horatio, Arkansas, a buff clay from Trenton, New Jersey, and a tan clay from Athens, Texas. The specimens will be fired at the temperature of 1643 degrees Fahrenheit...Experiments performed with the three clays will fall into three categories: (1) textures resulting from introduction of foreign matter into the clay (2) textures resulting from surface treatments of green ware and (3) textures resulting from surface treatments of bisque-fired ware. The experiments will be described and the fired clay specimens -- tiles 2"x2"x1/4" will be evaluated according to esthetic and practical standards.