http://hdl.handle.net/10294/2900 Doctoral level Theses and Dissertations 2017-07-09T21:24:02Z http://hdl.handle.net/10294/7767 A Novel Approach for Simulating Soil and Pipe Response to Seasonal, Environmental and Field Conditions Saadeldin, Ramy M. Climate change related problems are increasing in occurence and severity leading to significant econocmic losses in many places of the world. In semi-arid environments, like Saskatchewan, the main phenomenon involved in pipe breakages is the volume change behavior of unsaturated clay deposits. Underground pipelines are typically buried within the upper zone of soil deposits, and therefore, are highly affected by soil nature and the different environmental conditions present on the ground surface. To accurately model field conditions, a mathematical formulation of native soil conditions was developed based on a bimodal soil water characteristic curve (SWCC) and other constitutive relationships. In order to simulate the response of soil and pipe to various mateorological conditions, a numerical framework was developed and validated. The strength of the developed numerical framework lays in the use of bimodal SWCC and modeling the hydraulic characteristics of a cracked soil structure. This research study also utilized, as a database, the results of a filed instrumentation program conducted in the City of Regina. A hydro-mechanical analysis was implemented to model the volume change due to variations in mechanical loading conditions and moisture content. Modeling scenarios were also studied based on variations in pipe diameter, pipe depth and soil elasticity. The developed numerical framework provided insight into the sensitivity of pipe deformation to possible changes in input parameters of the soil-pipe system. The model was able to capture the transient water flow through Saturated-unsaturated soils. The results of the modeling of weather conditions applied on the soil-pipe system were in agreement with the field measurements. Specific relationships between the soil-pipe interaction and seasonal changes in the local meteorological conditions were established. The model was also used to provide some insight into the real flux transferred through the pavement structure to the backfill material surrounding the pipe. Finally, soil and pipe reactions (i.e. soil and pipe displacements, soil volumetric water content and soil temperature) to applied surface boundary conditions were predicted based on validated numerical approach A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy in Environmental Systems Engineering, University of Regina. xii, 239 p. 2016-04-01T00:00:00Z http://hdl.handle.net/10294/7756 Experimental Research on Multiphase Liquid Mobilization and Motion in Capillary and Micro Models Subjected to External Low Frequency Vibratory Excitations Zhang, Yihe The research of this dissertation experimentally investigates the impacts of external vibratory excitation on the mobilization and motion of multiphase liquid in capillary and microcell models, aiming for understanding the mechanism of oil-water mobilization and flow in pore structures subjected to external excitations. Experiments with capillary models are first conducted; in which both straight capillary and curved capillary models are employed as an analogue of the pore structures. The mobilization and motion of an oil slug trapped in the capillary models with capillary forces are studied in the research. The models considered are subjected to both external pressures created by water injection and vibratory excitations. The focuses of the experimental investigations are on the variation of the pressure drop across the capillary model, the oil slug travel distance in the model in a fixed time duration, and the flow phenomena during the period of mobilization and flow of the oil slug. It is found in the investigations, in comparing the situations of with and without external excitations, proper vibratory excitations may positively affect the mobilization and flow of the oil slug in the capillary models, in terms of reducing the external pressure needed for mobilizing the oil slug, stabilizing the flow of the oil slug and increasing the oil slug travel distance in a fixed duration. The joint effects of the external pressure and vibratory excitation on the mobilization and flow of the oil slug are measured and quantified in the research. The optimal conditions in terms of external pressure and vibration frequency and amplitude for promoting the oil slug mobilization and stable flow are also searched and determined via the experiments of the research. Two-dimensional micro model are more close to the pore structures of the reservoir in oil field. To study the motion of oil-water liquid in a two-dimensional manner, an etched glass micro model is designed and employed in the research to study the liquid mobilization and flow in a network pore structure. The intention of this study is to understand the mechanism of the external water pressure and vibratory excitation on oil recovery from liquid saturated porous media of a reservoir. Experiments without vibratory excitation are first conducted on the model and various phenomena are observed in the experiments, including the development of water film and water patches surrounding the oil droplets and oil patches, and the variations of the contact angles of the oil droplets. The experimental investigations with application of vibration excitation fall in two categories: oil displacement by applying vibration excitation after waterflooding and oil displacement by applying vibration excitation with waterflooding. The oil-displacing rate, oil-water distribution, and pressure drop are measured during the oil displacement. The fractional flow is calculated and analyzed. From the experimental results, it can be concluded that applying vibration excitation has positive effects on the oil displacement in terms of increasing the total oil-displacing rate in the micro model flow. The effect is much more noticeable when the oil-water ratio is high. Also, the efficiency of the oil recovery is found sensitive to the acceleration amplitude of the vibration excitation. By comparing the final oil-displacing rate, it is found that applying vibration excitation after waterflooding is more effective in comparing with that applying vibration excitation together with waterflooding. A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Industrial Systems Engineering, University of Regina. XXI, 182 p. 2017-03-01T00:00:00Z http://hdl.handle.net/10294/7755 Discourse and the Construction of the Science-Teacher-Subject: An Examination of why we say the Science Teacher is Elite Wernikowski, Mark Louis Science education has found itself in a paradoxical state of stagnant flux. Despite numerous calls for reform and a near consensus amongst science educators on the teaching techniques that hold the most promise, new pedagogical approaches have hardly been implemented. Scholarship advocating for pedagogical change tends to focus on examining teachers’ beliefs, instructional methods and student engagement. These approaches are limited as they often fail to account for the political, social and historical groundings of these practices. This study explores the relations of power, discipline and domination implicated in the construction of the science-teacher-subject. It employs a poststructural conceptualization of the subject of lack to invert the science teacher identity, shifting the focus from ontological questions of self towards an epistemological understanding of the process of subjectification. This epistemological query does not seek the “truth” of what the science teacher is, but rather recognizes that the science teacher is a genealogical formation integrally connected with social power. Using a discursive analytic, this study focuses on the production of science teachers’ identity by thirteen secondary school teachers and draws upon Foucaultian genealogy to demonstrate the implementation and performances of these “historical” discourses in the classroom. The science teacher is subjectified in the data as: 1) a passionate subject that holds a natural affinity for science and teaching science; 2) a gatekeeper to personal and societal advancement, opportunity and financial stability; 3) a modern subject charged with maintaining the narratives of enlightenment; and 4) a postpositivist subject that is responsible for promoting the interconnectedness of science, society and politics. Within this cacophony of diverse subjectifying calls, the science teacher is consistently given social status while being disciplined to maintain the hegemony of Western science. The epistemological supremacy of Western ways of knowing remains foundational in the field of secondary science education, and this framework continues to present the science teacher as objective, rational and blameless for the domination that secures its privileged position. While the science teacher is nearly powerless to change the direction of Western science, the teacher is rewarded with elite status for its reproduction. A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Education, University of Regina. ix, 233 p. 2017-03-01T00:00:00Z http://hdl.handle.net/10294/7754 Study of Ionic Liquids as Effective Solvents for Enhanced Heavy Oil Recovery Tunnish, Ahmed Injecting chemicals in reservoirs is an efficient technique to improve oil recovery. In this study, several types of Ionic Liquids (ILs) were initially screened using the Conductorlike Screening Model for Realistic Solvents (COSMO-RS) model. COSMO-RS, in particular, is capable of providing predictions of the thermodynamics properties of ILs. A comprehensive screening study of 148 probable cations and 46 anions was performed in order to shed some light on the interaction of ILs with hydrocarbons via the calculation of the capacity of the screened ILs to hydrocarbons fractions and water. The most suitable ILs for our purposes were chosen, and employed for improving heavy oil (14o API) recovery from sand pack at room conditions taking the cost, physical and chemical properties of the ILs into consideration. The selected ILs were 1-Dodecyl-3- methylimidazolium chloride [DMIM][Cl], 1-Ethyl-3-methylimidazolium acetate [EMIM][Ac], 1-Ethyl-3-methylimidazolium methyl sulfate [EMIM][MS], 1-Hexyl-3- methylimidazolium tetrafluoroborate [HMIM][Bf4], 1-Butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIM][Tf2N], 1-Methyl-3-octylimidazolium tetrafluoroborate [MOIM][Bf4], 1-Methyl-3-octylimidazolium hexafluorophosphate [MOIM][PF6], 1,3-Dimethylimidazolium tosylate [dMIM][TOS], 1-Benzyl-3- methylimidazolium tosylate [BenzMIM][TOS], N-methylpyridinium tosylate [MPyr][TOS], 1-Ethyl-3-methylimidazolium chloride [EMIM][Cl], 1-Benzyl-3- methylimidazolium chloride [BenzMIM][Cl], and Trihexyltetradecylphosphonium chloride [THTDPh][Cl]. A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Petroleum Systems Engineering, University of Regina. xiii, 243 p. 2017-03-01T00:00:00Z