<p>Fluorochlorozirconate (FCZ) glasses are a member of heavy metal fluoride glasses, and are derived from a well known ZBLAN glass. In this work, halogen salts of europium (Eu²⁺) and samarium (Sm³⁺) are used as dopants in FCZ glasses. FCZ glasses doped with Eu²⁺ and Sm³⁺ can be used in high resolution x-ray imaging for tissue scanning, and have been shown to behave as storage phosphors and/or x-ray scintillators.</p> <p>Glass transition (T_g), heat capacity (C_p) and glass crystallization (T_c) properties of Eu²⁺ and Sm³⁺ doped and undoped FCZ glasses with different amounts of relative Cl concentration, that is, with respect to the total Cl and F concentration have been investigated by conventional differential scanning calorimetry (DSC) and modulated differential scanning calorimetry (MDSC) techniques. MDSC experiments were performed at different heating rates to analyze the complex transitions and to get a better resolution of any overlapping transitions. The crystallization kinetics have also been studied by applying the Kissinger technique to multiple DSC scans in order to determine the thermal stability of FCZ glass samples used in this work. The apparent activation energy for the crystallization process was obtained by the crystallization peak temperature shift method in the conventional DSC mode. The specific heat capacity (C_p) has been measured as a function of composition, and the glass transition temperature (T_g) is evaluated from the smooth change in the heat capacity curve during the glass transformation. The observation of two possible glass transitions points to the presence of two phases in these FCZ glasses with higher relative Cl content.</p> <p>Optical transmission spectra of both doped and undoped FCZ glass samples have been measured by infrared spectroscopy and optical band gaps corresponding to an absorption coefficient of 10³ cm^-1 have been determined. A good correlation between X-ray luminescence and the glass structure is observed. While the integrated photoluminescence intensity increases linearly with the Sm³⁺ concentration, the integrated X-ray luminescence increases sublinearly. The importance of appropriate annealing conditions, such as temperature, time and ambient atmosphere, and their effect on the X-ray luminescence of rare earth (RE) doped FCZ glass samples have been investigated. Annealing conditions influence the formation of BaCl₂ nanocrystals in the glass and the properties of the resulting FCZ glass ceramics.</p>

Yttria Partially Stabilized Zirconia (Y-PSZ) plasma-sprayed coatings are widely used in turbine engines as thermal barrier coatings. However, in diesel engines Y-PSZ TBCs have not met with wide success. To reach the desirable temperature of 850-900˚C in the combustion chamber from the current temperature of 400-600˚C, a coating with a thickness of approximately 1mm is required. This introduces different considerations than in the case of turbine blade coatings, which are on the order of 100µm thick. Of the many factors affecting the durability and failure mechanism of TBCs, in service and residual stresses play an especially important role as the thickness of the coating increases. For decreasing the residual stress in the system, a multi-layer coating is helpful. The design of a multilayer coating employing relatively low cost materials with complementary thermal properties is described. Numerical models were used to describe the residual stress after deposition and under operating conditions for a multilayer coating that exhibited the desired temperature gradient. Results showed that the multilayer coating had a lower maximum stress under service conditions than a conventional Y-PSZ coating. Model validation with experiments showed a good match between the two.

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The technique of Nanoindentation in situ Transmission Electron Microscope has been implemented on a Philips CM20. Indentations have been performed on Si and Sapphire (α-Al2O3) cut from wafers; Cr/Sc multilayers and Ti3SiC2 thin films. Different sample geometries and preparation methods have been evaluated. Both conventional ion and Focused Ion Beam milling were used, with different ways of protecting the sample during milling. Observations were made of bending and fracture of samples, dislocation nucleation and dislocation movement. Basal slip was observed upon unloading in Sapphire. Dislocation movement constricted along the basal planes were observed in Ti3SiC2. Post indentation electron microscopy revealed kink formation in Ti3SiC2 and layer rotation and slip across layers in Cr/Sc multilayer stacks. Limitations of the technique are presented and discussed.

<p>Fluorochlorozirconate (FCZ) glasses are a member of heavy metal fluoride glasses, and are derived from a well known ZBLAN glass. In this work, halogen salts of europium (Eu²⁺) and samarium (Sm³⁺) are used as dopants in FCZ glasses. FCZ glasses doped with Eu²⁺ and Sm³⁺ can be used in high resolution x-ray imaging for tissue scanning, and have been shown to behave as storage phosphors and/or x-ray scintillators.</p> <p>Glass transition (T_g), heat capacity (C_p) and glass crystallization (T_c) properties of Eu²⁺ and Sm³⁺ doped and undoped FCZ glasses with different amounts of relative Cl concentration, that is, with respect to the total Cl and F concentration have been investigated by conventional differential scanning calorimetry (DSC) and modulated differential scanning calorimetry (MDSC) techniques. MDSC experiments were performed at different heating rates to analyze the complex transitions and to get a better resolution of any overlapping transitions. The crystallization kinetics have also been studied by applying the Kissinger technique to multiple DSC scans in order to determine the thermal stability of FCZ glass samples used in this work. The apparent activation energy for the crystallization process was obtained by the crystallization peak temperature shift method in the conventional DSC mode. The specific heat capacity (C_p) has been measured as a function of composition, and the glass transition temperature (T_g) is evaluated from the smooth change in the heat capacity curve during the glass transformation. The observation of two possible glass transitions points to the presence of two phases in these FCZ glasses with higher relative Cl content.</p> <p>Optical transmission spectra of both doped and undoped FCZ glass samples have been measured by infrared spectroscopy and optical band gaps corresponding to an absorption coefficient of 10³ cm^-1 have been determined. A good correlation between X-ray luminescence and the glass structure is observed. While the integrated photoluminescence intensity increases linearly with the Sm³⁺ concentration, the integrated X-ray luminescence increases sublinearly. The importance of appropriate annealing conditions, such as temperature, time and ambient atmosphere, and their effect on the X-ray luminescence of rare earth (RE) doped FCZ glass samples have been investigated. Annealing conditions influence the formation of BaCl₂ nanocrystals in the glass and the properties of the resulting FCZ glass ceramics.</p>

Clarks Crossing, FbNo-24, is a farmstead site occupied during the late nineteenth century by John Fowler and Maggie Clark. It was during the excavation of this site during the Department of Archaeology Historical Archaeology Field School (2002-2005) at the University of Saskatchewan, under the direction of Dr. Margaret Kennedy, that interesting patterns in the ceramic assemblage were observed. There seemed to be a preference in the assemblage for moulded relief decorated white granite ware ceramics. This research was undertaken to explore that preference and possible meanings behind it. Three avenues of study are undertaken to accomplish the goal of learning more about the relationship between ceramics, consumer behaviour and the sociocultural landscape of the nineteenth century west. These avenues are as follows; a historical and archaeological study of the Clarks and the site of Clarks Crossing, a discussion of white granite ware ceramics and the issues regarding its classification, and an analysis of the ceramics at Clarks Crossing including an examination of the ware types, the makers marks, and the decorative technique and images found on the ceramics.<p> The behaviour of consumers can be influenced by several factors, including marketing and group membership or identity. Marketing can be a separate influence but it can also be seen as a factor in creating a perceived group identity. This thesis explores the influences on consumer behaviour in ceramics, specifically the ceramics of Clarks Crossing. It will discuss the implication that the ware type and decorative images on the ceramics act as the material manifestation of such influences.

Pulsed laser deposition (PLD) was used to deposit hydroxyapatite (HA) thin films on various substrates, including silicon (100) and titanium (Ti-6Al-4V) alloy. Thin films of amorphous HA were deposited at room temperature and then annealed over a range of temperatures. The microstructure and composition of the films were determined using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), and X-ray diffraction (XRD). The HA films were found to achieve total crystallinity at 350㮠The mechanical properties of the films were studied by means of nanoindentation and scratch adhesion testing. Crystalline and adherent HA thin films prepared using PLD and post deposition annealing have many potential medical and dental applications.

During the fall of 1973, the newly formed (American) Institute of Nautical Archaeology conducted its first systematic underwater survey of the southwestern coast of Turkey with the goal of locating the first shipwreck to be subsequently excavated by the Institute. Of the 18 wreck sites identified during the survey, a site off Sheytan Deresi (Devil’s Creek) proved to be the one that attracted George Bass, director of the survey, as most meriting further study. During the excavation that followed in September and October 1975, the site produced a number of complete and fragmentary ceramic vessels that formed the main artifact assemblage. Although the ceramic vessels brought to light at Sheytan Deresi have been studied by George Bass, Roxani Margariti and others since the 1975 excavation, locating precise parallels for the assemblage proved a difficult task and resulted in a less than full understanding of the site. The following thesis represents a renewed effort to answer a number of questions still surrounding the Sheytan Deresi site. In addition to expanding the extensive search for parallels undertaken by Bass and Margariti, recent research has involved a number of scientific analyses, including petrographic analysis of the ceramic assemblage, luminescence dating of ceramic fragments, and elemental examination of the fabric through neutron activation analysis and energy dispersive spectroscopy. The use of three-dimensional modeling has been adopted for the purposes of site interpretation. Although the impact of this more holistic approach cannot be entirely foreseen at this time, a number of interesting hypotheses regarding the site can now be suggested. It appears that the ceramic assemblage, which is now conclusively of a single origin, may be of a specialized maritime nature, and likely belongs to the Middle Bronze Age, reminiscent of, but entirely similar to, regional types of Anatolian and Cretan vessels. These tentative conclusions, as well as an examination of the site itself, suggest that the (Minoanizing) ceramic assemblage of Sheytan Deresi stood witness to a fairly small Middle Bronze Age coastal trading vessel that capsized rounding a dangerous cape, not far from its point of origin. We are still not in a position to fully comprehend the wrecking event that took place at Sheytan Deresi, but we are now firmly on course towards reaching that objective.

ZnO is a promising semiconducting material for manufacturing optoelectronic devices. Its most important properties are its wide and direct band gap and its high electron-hole binding energy. Synthesis of ZnO in bulk and thin film form has been investigated intensively over recent decades. Likewise, nanomaterials have been in the point of focus for their different properties compared to their bulk form. The vastly increased ratio of surface area to volume and change in electronic properties with great reduction in particle size enable improved performance in conventional applications where their bulk counterparts have been used for decades. As a result of this trend, research on synthesis of ZnO nanowires and their incorporation in prototype optoelectronic devices has been intensive in recent years. Therefore, synthesis of ZnO nanowires in a cost effective way and understanding the factors influencing the ZnO nanowire growth is essential for contribution to ongoing research. V In this thesis, hydrothermal synthesis of ZnO nanowires, which is a solution based method enabling vertically aligned ZnO nanowire array fabrication over large areas, is investigated. In the first part of this thesis, the effect of using various zinc salts as zinc sources on ZnO nanowires is investigated by monitoring pH, temperature and light transmittance of growth solutions. In the second part, a detailed parametric study on the use of zinc acetate dihydrate salt is provided with regard to the existence of its unique properties compared to other two zinc salts. The effect of growth time, temperature, ratio of concentration of precursor chemicals and precursor chemical concentrations is investigated. The results show that hydrothermal synthesis method could replace the conventional ZnO nanowire fabrication methods. It was shown that specific nanowire lengths for any application can be obtained simply by adjusting the parameters of hydrothermal growth system.

Ceramics can highly withstand the environments of high temperature and serious erosion, it completely substitutes for alloys which reach their specific limitations. Turbine rotor operates in the compressed stage with temperature over thousand Celsius degrees; it must rely on excellent properties of ceramics to elevate the durability and lifetime. To manufacture complex ceramic component before, industry usually uses near net shaping or rapid prototyping (RP) processes. A manufacturing process based on machining green ceramic turbine component is presented here. Initially, formulating a series of machining experiments for green ceramics to verify the idea of thesis, and analyzing the probability of Al2O3 ceramic as a turbine material. Firstly, it needs to check the machinability of green ceramic by face milling. Secondly, point milling the normal plate of green compact and the plate with analogical blade geometry to find a set of usable machining parameters (such as revolution speed, feed rate, step over and cutting depth); meanwhile, addressing machining amendment by observing the final conditions of specific geometric characteristics on workpiece. Finally, try to machining green ceramic turbine successfully applying the above parameters.