Quantifying confinement effects in ice impact loads

Ships and offshore structures, that encounter ice floes, tend to experience loads with varying pressure distributions within the contact patch. The effect of the surrounding ice adjacent to that which is involved in the contact zone has an influence on the effective strength. This effect has come to be called confinement. A methodology for quantifying ice sample confinement is developed, and the confinement is defined using two non-dimensional terms; a ratio of geometries and an angle. Together these terms are used to modify force predictions that account for increased fracturing and spalling at lower confinement levels. Data developed through laboratory experimentation is studied using dimensional analysis. The characteristics of dimensional analysis allow for easy comparison between many different load cases; provided the impact scenario is consistent. In all, a methodology is developed for analyzing ice impact testing considering confinement effects on force levels, with the potential for extrapolating these tests to full size collision events.

Vernacular perceptions of masculinity and fatherhood among Newfoundland offshore workers and their families

My thesis is an ethnographic study of how offshore workers of Newfoundland and Labrador, as well as their families, express and reflect upon traditional Newfoundland constructs of fatherhood and masculinity through narrative and ritual. With a schedule that often involves a constant shift between home and away, offshore workers in the province take part in high-risk professions in order to provide for their families back home. These professions, and their associated lifestyles, involve the incorporation of routine strategies that allows family culture to maintain itself. At the same time, these professions largely carry on a tradition of hegemonically masculine practices, albeit in a newer context. Drawing on a blend of literary and ethnographic research based on the Avalon Peninsula, I utilize examples of current Newfoundland culture to describe how nostalgic memoirs of outport Newfoundland create models of hegemonically masculine fatherhood in the province. I go on to explain how those models manifest themselves in the experiences of current offshore workers, and how they affect their spouses and children. Furthermore, through examining how young adults with offshore-working parents describe their experiences of their fathers, it is possible to see how the effects of local hegemonic masculinities are manifested through narratives about fathers who worked away from home.

Functional genomic and molecular analyses of transcripts related to glycerol synthesis and trafficking in rainbow smelt (Osmerus mordax) using cold temperature-induced models of glycerol production

The rainbow smelt (Osmerus mordax) is an anadromous teleost that produces type II antifreeze protein (AFP) and accumulates modest urea and high glycerol levels in plasma and tissues as adaptive cryoprotectant mechanisms in sub-zero temperatures. It is known that glyceroneogenesis occurs in liver via a branch in glycolysis and gluconeogenesis and is activated by low temperature; however, the precise mechanisms of glycerol synthesis and trafficking in smelt remain to be elucidated. The objective of this thesis was to provide further insight using functional genomic techniques [e.g. suppression subtractive hybridization (SSH) cDNA library construction, microarray analyses] and molecular analyses [e.g. cloning, quantitative reverse transcription - polymerase chain reaction (QPCR)]. Novel molecular mechanisms related to glyceroneogenesis were deciphered by comparing the transcript expression profiles of glycerol (cold temperature) and non-glycerol (warm temperature) accumulating hepatocytes (Chapter 2) and livers from intact smelt (Chapter 3). Briefly, glycerol synthesis can be initiated from both amino acids and carbohydrate; however carbohydrate appears to be the preferred source when it is readily available. In glycerol accumulating hepatocytes, levels of the hepatic glucose transporter (GLUT2) plummeted and transcript levels of a suite of genes (PEPCK, MDH2, AAT2, GDH and AQP9) associated with the mobilization of amino acids to fuel glycerol synthesis were all transiently higher. In contrast, in glycerol accumulating livers from intact smelt, glycerol synthesis was primarily fuelled by glycogen degradation with higher PGM and PFK (glycolysis) transcript levels. Whether initiated from amino acids or carbohydrate, there were common metabolic underpinnings. Increased PDK2 (an inhibitor of PDH) transcript levels would direct pyruvate derived from amino acids and / or DHAP derived from G6P to glycerol as opposed to oxidation via the citric acid cycle. Robust LIPL (triglyceride catabolism) transcript levels would provide free fatty acids that could be oxidized to fuel ATP synthesis. Increased cGPDH (glyceroneogenesis) transcript levels were not required for increased glycerol production, suggesting that regulation is more likely by post-translational modification. Finally, levels of a transcript potentially encoding glycerol-3-phosphatase, an enzyme not yet characterized in any vertebrate species, were transiently higher. These comparisons also led to the novel discoveries that increased G6Pase (glucose synthesis) and increased GS (glutamine synthesis) transcript levels were part of the low temperature response in smelt. Glucose may provide increased colligative protection against freezing; whereas glutamine could serve to store nitrogen released from amino acid catabolism in a non-toxic form and / or be used to synthesize urea via purine synthesis-uricolysis. Novel key aspects of cryoprotectant osmolyte (glycerol and urea) trafficking were elucidated by cloning and characterizing three aquaglyceroporin (GLP)-encoding genes from smelt at the gene and cDNA levels in Chapter 4. GLPs are integral membrane proteins that facilitate passive movement of water, glycerol and urea across cellular membranes. The highlight was the discovery that AQP10ba transcript levels always increase in posterior kidney only at low temperature. This AQP10b gene paralogue may have evolved to aid in the reabsorption of urea from the proximal tubule. This research has contributed significantly to a general understanding of the cold adaptation response in smelt, and more specifically to the development of a working scenario for the mechanisms involved in glycerol synthesis and trafficking in this species.

Phase and partitioning behavior of phenols and polycyclic aromatic hydrocarbons in offshore oil and gas produced water

Produced water constitutes the largest volume of waste from offshore oil and gas operations and is composed of a wide range of organic and inorganic compounds. Although treatment processes have to meet strict oil in water regulations, the definition of “oil” is a function of the analysis process and may include aliphatic hydrocarbons which have limited environmental impact due to degradability whilst ignoring problematic dissolved petroleum species. This thesis presents the partitioning behavior of oil in produced water as a function of temperature and salinity to identify compounds of environmental concern. Phenol, p-cresol, and 4-tert-butylphenol were studied because of their xenoestrogenic power; other compounds studied are polycyclic aromatic hydrocarbon PAHs which include naphthalene, fluorene, phenanthrene, and pyrene. Partitioning experiments were carried out in an Innova incubator for 48 hours, temperature was varied from 4ﾟC to 70ﾟC, and two salinity levels of 46.8‰ and 66.8‰ were studied. Results obtained showed that the dispersed oil concentration in the water reduces with settling time and equilibrium was attained at 48 h settling time. Polycyclic aromatic hydrocarbons (PAHs) partitions based on dispersed oil concentration whereas phenols are not significantly affected by dispersed oil concentration. Higher temperature favors partitioning of PAHs into the water phase. Salinity has negligible effect on partitioning pattern of phenols and PAHs studied. Simulation results obtained from the Aspen HYSYS model shows that temperature and oil droplet distribution greatly influences the efficiency of produced water treatment system.

Exploring the stages of change and perceived barriers to treatment models within the context of parental adherence to an early intervention program

Parent-mediated early intervention programs depend on the willingness and ability of parents to complete prescribed activities with their children. In other contexts, internal factors, such as stages of change, and external factors, such as barriers to treatment, have been shown to correlate with adherence to service. This researcher modified the Stages of Change Questionnaire as well as the Barriers to Treatment Participation Scale (BTPS) to use with this population. Despite initial interest, twenty-three parent participants were referred to the researcher over the course of three years, with only five parents taking part in the study. A population base ten times that of the current sample would be required recruit enough participants (fifty-one) to provide sufficient power. This feasibility study discusses the results of the five parent participants. Findings suggest that the modified Stages of Change Questionnaire may not be sensitive enough for use with the current sample, while the modified BTPS may yield useful information for service providers.