In this work an extended literature survey on ceramics and porcelains in particular, has been documented. Samples from two Ugandan deposits of each feldspar and quartz were characterised by means of X-ray diffraction, thermal analysis, chemical analysis and scanning electron microscopy and found to possess requisite properties for making electro porcelain insulators. Five porcelain bodies were formulated and samples were fabricated from materials collected from selected deposits in Uganda using different mixing proportions of clay, feldspar and quartz. The properties of the formulated bodies were studied in relation to workability, firing temperature, dielectric and bending strengths. The strengths (both mechanical and dielectric) were found to decrease as the firing temperature was increased above 1250°C. Additionally, ten formulations with components in the range of 30-60% clay, 20-45% feldspar and 20-25% sand were prepared. Specimens for mechanical and physical characterisation were made using the plastic extrusion method. The samples were characterised in terms of constituent oxide composition, flexural strength, fracture toughness, dielectric strength along with microstructural and phase properties using ICP-AES analyses, 4-point load bending strength test, Vicker’s indentation method, SEM and XRD analyses respectively. XRD studies revealed that the crystalline phases formed were mullite and quartz and their intensity was almost identical for all samples fired at 1250°C but there was a decrease inquartz content as temperature was increased above 1250°C. Samples with 20% sandcontent resulted in higher density, MOR and fracture toughness compared to thosecontaining 25% sand. Mullite content on the other hand did not change at temperatures above 1200°C but there were significant differences in the morphologies of the mullite crystals in the samples. Optimum mechanical and electrical properties were found at maximum vitrification and a microstructure showing small closely packed mullite needles. This occurred at a firing temperature of 1250°C. Three promising porcelain formulations from the above investigations were chosen and five glazes formulated to fit on biscuit fired specimens. The best-fitting glaze was adopted. The formulated specimens were investigated using dilatometry, Steger test, FEG-SEM, XRD, 4-point bending, dielectric strength and fracture toughness tests. A porcelain specimen consisting of 68% SiO2, 19% Al2O3, 4.7% K2O and a glaze of Seger formula RO:0.57Al2O3:4.86SiO2 exhibited MOR of 105MPa with Weibull modulus of 5.6 and a dielectric strength of 18kV/mm upon firing at a heating rate of 6ºC/min to 1250ºC, soaking for 2h at the top temperature and cooling down to 500°C at a rate of 6°C/min, followed by furnace cooling. The microstructure of the high strength specimen exhibited round mullite needles, quartz and glass. Holding samples for 2h at peak temperature resulted in a 22% increase in MOR compared to 1h holding. Glazing further improved strength by 67% for the best sample. Compressive stresses in glaze contributed to the strengthening effect. The dielectric and mechanical strengths obtained make the ormulated sample suitable for application in low voltage electrical insulation. / QC20100609

Autographen J. F. Böttgers (1682-1719) gehören zu den Raritäten des Archivs der Porzellanmanufaktur Meißen und der SLUB. Eine größere Anzahl davon befindet sich im Sächsischen Hauptstaatsarchiv zu Dresden.

This thesis examines the extent to which the 1960s process art strand of post-Minimalism can provide an analytical template for critical writing around contemporary ceramic art. A dearth of critical writing is an acknowledged problem in all types of ceramics practice and some of the reasons for this situation will be explored. In the past decade frequent calls have been made by artists, critics, academics, and curators for a body of critical writing to underpin contemporary work and connect with wider cultural debates. During this period, artists have begun to use the process of making the work to form part of the content. Such work has no relationship to traditional studio pottery, and critics have described it as difficult to write about and classify in normative ceramic terms. However, this area of ceramic practice shares characteristics with post-Minimalism, a movement of the 1960s that emphasised the behaviour of materials and the act of making. In The Archaeology of Knowledge the French philosopher Michel Foucault suggests that a new critical language may emerge from the appropriation of other discourses, providing new interpretations for subject areas not yet theoretically mapped out. Foucault’s notions on the formation of discourse are used as a methodological approach to investigate how process-led sculptural ceramics may be articulated by an understanding of post-Minimalist critical writings. A substantial body of critical writing developed around post-Minimalist process art, providing a context for radical new approaches which broke with modernist traditions and which expanded and changed traditional definitions of sculpture. Key post-Minimalist texts are investigated as an analytical template for a new critical discourse for process-led ceramic art. A study of the sculptural ceramics of Richard Deacon and Kosho is undertaken as a means of identifying process-led tendencies and the possibility of a re-conceptualisation from a post-minimalist perspective. An analysis of the role of process within my own practice is used to provide visual evidence of contemporary ceramic work that can be re-conceptualised from a post-Minimalist perspective. After twenty years of stagnant debate in the ceramics field, this research might provide a new critical context for process-led ceramic art. The project shows a way that artists may be empowered to develop a critical literacy in a field that has traditionally lacked a research based approach. It is hoped that it may well encourage other ceramics practitioners to explore new ways of presenting an academic critique of their own area of practice. The contribution to knowledge identifies a new critical context and approach to writing for the process-led area of ceramics practice that is currently described as being difficult to write about, as having no appropriate critical language of its own, and of being difficult to categorise in standard ceramic terms.

Contemporary Canadian artist Shary Boyle's varied body of work includes: drawings, paintings, performance art and sculpture. While Boyle has received national and international recognition, there has not been an in-depth scholarly study of this prolific artist. In particular, this thesis will focus on Boyle's lace draped porcelain figures, created between 2002-2006, as well as select drawings from her "Porcelain Fantasy Series." It will examine her use of both the familiar, as well as the subversive powers of the grotesque, as she appropriates visual motifs used in traditional porcelain figurines. Through the grotesque she disrupts and challenges patriarchal constructions, and the consumption, of feminine beauty that is typically represented in these figurines. Her work both critiques and draws attention to restrictions these constructions have placed on women, as well as providing images of emancipation.

Thesis (M.S.)--University of Michigan, 1977.

Thesis (M.S.)--University of Michigan, 2003. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1977.

Thesis (M.S.)--University of Michigan, 1991.

Thesis (M.S.)--University of Michigan, 2003. / Includes bibliographical references.

A novel approach for inspecting the condition of porcelain insulators based on statistical analysis of electromagnetic radiations of live insulators is demonstrated in this thesis. Physical defects such as puncture and contamination can degrade the insulators performance and result in power outages, potentiating costs to utilities. Therefore, condition assessment of line insulators has always been one of the most important aspects of maintenance programs in power networks. Realistic replicas of punctured and contaminated insulators were created in the High Voltage Lab at University of Manitoba, following the IEC standards. These defective insulators were tested under high voltage stress while the electromagnetic radiations originated from the partial discharge activities on the insulators were captured using electromagnetic sensors. During the experimental part of this thesis, a multitude of tests were conducted and resulted in measuring and recording a total of 410,000 cycles of discharge activities. The feature extraction algorithm, developed as part of this thesis, calculates the statistical features of the phase resolved interpretation of partial discharge (PD) pulses. The results of analyzing the extracted features from the radiated signature of defective insulators indicate that the scale and shape parameters of a two sided Weibull distribution function fit to the recorded measurement entail distinct information about the source of discharges that can be used to identify the source of defects. Based on the library of features extracted from the recorded electromagnetic radiations, a support vector machine (SVM) classier, developed as part of this thesis, can successfully classify the radiation signature of punctured and contaminated insulators. Therefore, the main outcome of this research was introducing a novel porcelain insulator inspection technique that can remotely differentiate the defective punctured and contaminated insulators using their electromagnetic radiation signature in a laboratory environment. By utilizing the signature of common discharge activities present in the recorded signature of all tested insulators, a gating algorithm was developed which improved the successful classification rate from 51 % to 75%. The inspection technique proposed in this research can eliminate the safety hazards involved in the live maintenance of line insulators, lower the maintenance costs, and improve the inspection efficiency considering the conventional labour intensive live maintenance assessments. / February 2016