E911 creep samples exposed to temperatures of 600˚C, 625˚C and 650˚C at differing stress levels were supplied by CORUS. The hardness of the gauge length that experienced both creep strain and temperature was found to be lower than that of the head where thermal softening only can be assumed. The changes in the morphology and size of precipitates were observed qualitatively by optical microscopy and Scanning Electron Microscopy. A creep fracture mechanism map of E911 steel was constructed with two modes of creep (transgranular and intergranular ). A fitted ellipse shape was used to characterise the irregular block shape by Electron Backscattered Diffraction (EBSD). It showed that the width of the block inside a prior austenite grain increases more rapidly in the gauge length than in the head; subgrain growth was also observed by EBSD. Transmission Electron Microscopy studies indicate that at 600°C E911 steel can reach up to 75647 hours creep rupture life (108MPa), which is due to the relatively small size of M23C6, Laves and M2X phases. However, Z phase precipitation results in a drop in creep resistance owing to the dissolution of fine MX phase and the transformation of M2X phase. At 625°C and 650°C, the creep rupture life decreases owing to the coarsening of Laves, M23C6 and M2X phases. Four experimental steel casts were prepared with varying levels of Ni and Cr to investigate the effect of these elements on Z phase formation. After 10,000 hours exposure, there was little evidence of Z phase in the samples studied and therefore it is difficult to draw definitive conclusions about the role of Ni or Cr in promoting Z phase formation. It is possible that the casts studied here will allow better conclusions to be drawn after exposing the samples to longer durations.

This study investigates the relationship between the ancient settlements (in Lycia) and physical environmental parameters including topography, rock and soil types using GIS. Modern settlements are also included in the study to analyze if the response has changed to these parameters from past to the present. The databases created in the study include three topographic attributes (elevation, slope and aspect), rock type, soil type, ancient settlements and modern settlements. Analyses performed in the study involve distance and density analyses of ancient and modern settlements, morphological analysis, distribution of ancient and modern settlements within the rock and soil types, and visibility analysis of ancient settlements. Results of the analyses suggest that the ancient sites are located on the east, southeast, south facing and flat surfaces at slope values of 0 to 13 degrees within the elevation range of 0 to 1000 m. The average distance between the cities is 7 km preferably located over alluvium or limestone rock types with the soil types having thickness more than 20 cm. A set of decision rules are derived from the ancient settlements using above mentioned data layers to predict location of unknown settlements. This analysis indicated a few locations along the Mediterranean coast.

The interactions between ligands and transition metals have been an essential subject in inorganic chemistry. Other than the commonly known L-type (two-electron donors) and X-type ligands (one-electron donors), Z-type ligands (two-electron acceptors) have begun to surface in the past decade. Capable of drawing a pair of d-electrons away from a metal, Z-ligands affect the electronic structures of transition metals leading to fascinating properties as well as reactivity. In particular, recent advance in Z-ligand chemistry have resulted in the discovery of transition metal borane complexes featuring metal → boron interactions. Owing to the presence of a metal → boron interaction which stabilizes the low valent state, these complexes have been shown to activate small molecules such as H2, CO2, and CHCl3. Further, the concept of Z-ligand has been extended to s- and d-block Lewis acids. In spite of these achievements, Z-ligands that contain Group 14-16 elements as Lewis acids remain scarce and relatively unexplored. For this reason, we have launched a series of investigations targeting complexes with transition metal → Group 14-16 interactions. These investigations have allowed us to synthesize a series of novel complexes with palladium, platinum, or gold as metallobasic late transition metals and tin, antimony, bismuth, and tellurium as Lewis acids. The transition metal → Lewis acid interactions of these complexes, which are supported by o-phosphinophenylene, 1,8-naphthalenediyl or 8-quinolinyl buttresses, have been established experimentally and theoretically. Further, the reactivity of these complexes toward anions and oxidants has also been explored. These experiments have led to the discovery of tellurium-platinum complexes that sustain reversible two-electron redox processes including the photo-reductive elimination of chlorine. Other noteworthy outcomes of this research include the isolation of the first telluroxanyl-metal complex as well as the discovery of complexes with HgII → SbV interactions.

Title: Is maternal hypotension during pregnancy and/or posterior located placenta associated with increased risk of stillbirth? Design: A retrospective case-controlled study comparing a group of stillbirths with a live born control group matched for maternal age, baby gender, gestational age and year of birth. The purpose of this study was to ascertain whether hypotensive women or women with a posterior located placenta are at increased risk of stillbirth. Two Australian tertiary referral obstetric hospitals were chosen as participating hospitals for this study. All cases with a discharge diagnosis of stillbirth over a five year period at these hospitals were identified and considered as cases for inclusion in the study. An attempt was made to match each case with two controls. After exclusions there were 124 cases and 243 controls. Blood pressure (BP) readings throughout pregnancy were extracted from the medical record of each subject, and summary 'exposure' measures were created. These included: diastolic and systolic readings as well as mean arterial pressure taken at the initial (booking BP), minimum, calculated average, and final reading prior to the birth. Placental position, as determined by midtrimester ultrasound, was also collected. Results: This study found that low Diastolic Blood Pressure (DBP) readings (between 60-70mmHg) throughout pregnancy were associated with a statistically significant increased risk of stillbirth. This trend was seen from the initial reading at booking (OR 1.83 95% CI 1.0-3.2, p=0.03) through to the last taken before the birth (OR 1.53 95% CI 0.9-2.5, p=0.09) including the calculated average over the course of the pregnancy (OR 1.61 95% CI 1.0-2.6, p=0.05) and minimum observed during the pregnancy (OR 2.94 95% CI 0.98-8.8, p=0.05). In addition, this study found a minimum diastolic reading of less than 60mmHg carries a significant risk of stillbirth with a crude odds ratio of 3.5 (95% CI 1.18-10.41, p=0.02). This study did not show a statistically ignificant association of systolic hypotension with stillbirth. However, after combining both systolic and diastolic blood pressures to calculate the mean arterial blood pressure (MAP) the analysis did suggest that women with a minimum MAP between 73-83mmHg were at increased risk of stillbirth (OR 1.69 CI 1.02-2.81, p=0.04). Furthermore, this study found that three MAP readings of less than 83.3 during the course of the pregnancy carries almost twice the risk of stillbirth (adjusted OR 1.99) even after adjusting for race, gravidity, parity, BMI and SGA (and matching for maternal age, gestational age, gender and year of birth.) Women who have a posterior located placenta were statistically more likely to suffer a stillbirth than women who had a placenta in any other position (crude OR 1.64) and this estimate was largely unaffected by adjustment for blood pressure and other putative risk factors (adjusted OR 1.67) Conclusion: In conclusion, this is the first study which specifically examined a stillborn population in order to explore whether maternal hypotension and posterior located placenta impact negatively on stillbirth incidence and the results of this study suggest that both maternal hypotension and posterior located placenta are probably independent contributory risk factors for stillbirth. This means that maternity care providers should closely manage and monitor progress of women who are hypotensive during pregnancy or those whose placenta is posterior; and that effective management strategies need to be developed to care for these women. / Thesis (Ph.D.)--School of Population Health and Clinical Practice, 2007.

Specification animation has become a popular technique in industry, particularly for validation in model-based design processes. Animation tools provide the ability to explore and visualise the behaviour of a model without needing to study its internal workings. Formal refinement techniques should also be of interest to industry since they support verifiably correct transformations of system models towards implementation. So far, however, refinement techniques are not widely used. Their application requires a high degree of mathematical skill, even with the currently available tool support. Better tool support is needed to make refinement techniques accessible to industry. In this thesis we investigate the application of existing specification animation and visualisation tools to problems in refinement theory. We show how animation and visualisation can be used to support verification, by refinement, and validation, by comparing the behaviour of a refined specification against its abstract specification. Such techniques can be used to explain and/or improve the understanding of a refinement and to check for the presence of errors in a refinement, for example, before attempting a proof. In the most challenging cases, data refinements, the designer needs to supply an abstraction relation in order to prove the refinement. We initially assume that an abstraction relation is provided as an input to the verification and validation tasks. However, finding abstraction relations is hard, and is currently a matter of trial and error. We therefore study the problem of finding abstraction relations. We show that, if an abstraction relation exists, there is always a unique weakest abstraction relation and at least one minimal abstraction relation, and we describe algorithms for finding both the weakest abstraction relation and minimal abstraction relations. These algorithms can be applied to small finite-state systems to produce abstraction relations in terms of explicit values of state variables. We then investigate a symbolic algorithm for finding abstraction relations, which can be applied to systems with infinite states, to produce abstraction relations in predicate form. The theory and the algorithms we develop thus make it possible for us to extend our animation-based verification and validation techniques so that they can be used without providing a complete abstraction relation. Additionally our extended techniques can help a designer construct an abstraction relation or check a proposed one.

Thèses (M.Sc.)--Université de Sherbrooke (Canada), 1997. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thèses (M.Sc.A.)--Université de Sherbrooke (Canada), 1998. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thèses (M.Sc.A.)--Université de Sherbrooke (Canada), 2001. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thèses (M.Sc.)--Université de Sherbrooke (Canada), 2004. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2008. / Full text also available online. Scroll down for electronic link.