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Theses and Dissertations

This collection contains theses and dissertations of graduate students of the University of Alberta. The collection contains a very large number of theses electronically available that were granted from 1947's to 2009, 90% of theses granted from 2009-2014, and 100% of theses granted from April 2014 to the present (as long as the theses are not under temporary embargo by agreement with the Faculty of Graduate Studies and Research). IMPORTANT NOTE: To conduct a comprehensive search of all UofA theses granted and in University of Alberta Libraries collections, search the library catalogue at www.library.ualberta.ca - you may search by Author, Title, Keyword, or search by Department. To retrieve all theses and dissertations associated with a specific department from the library catalogue, choose 'Advanced' and keyword search "university of alberta dept of english" OR "university of alberta department of english" (for example). Past graduates who wish to have their thesis or dissertation added to this collection can contact the ERA Mediated HelpDesk at erahelp@ualberta.ca.

Please note: current students needing to deposit their thesis or dissertation for review as required for convocation must follow the steps outlined here.

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Items in this Collection
  1. Multiple Outcomes in Heart Failure Research: Composite Endpoints and Multivariate Modelling [Download]

    Title: Multiple Outcomes in Heart Failure Research: Composite Endpoints and Multivariate Modelling
    Creator: Brown, Paul M
    Description: Composite endpoints are increasingly popular outcomes in clinical trials of heart failure. Uptake has outpaced guidance on their use and little consistency is seen in their construction. We must consider how best to handle multiple outcomes statistically and clinically, ie in a way that is both cogent for the clinical audience and statistically powerful. The clinical interpretation of composites has been emphasised along with its straightforward analysis and presentation. However there is a loss of information and a more thorough statistical analysis may offer advantages that are not easily dismissed, most obviously a gain in statistical efficiency and power. The modelling approach offers a number of other advantages: 1) adjustment for covariates, 2) a simple test of heterogeneity as the interaction between treatment and outcome, 3) analyses of the individual component endpoints are a consequence of the model, 4) correlations among outcomes are acknowledged, 5) recognises a constellation of risk factors or manifestations of the syndrome without blending them, 6) clinical weights are easily incorporated, and 7) an overall estimate of the effect is obtainable - making it comparable with the results from a composite endpoint. Thus the multivariate modelling approach yields a more powerful and thorough analysis without the loss of information that occurs when multiple outcomes are reduced to a single univariate composite measure. We use data simulations and real clinical trial data to illustrate and evaluate clinical composite endpoints and multivariate modelling. We developed SAS macros for data simulations and analysis methods which we make available.
    Subjects: multivariate, composite endpoint, heart failure, random effects, probability index
  2. Effect of Desorption Purge Gas Oxygen Impurity on Heel Formation During Regeneration of Beaded Activated Carbon Saturated with Organic Vapors [Download]

    Title: Effect of Desorption Purge Gas Oxygen Impurity on Heel Formation During Regeneration of Beaded Activated Carbon Saturated with Organic Vapors
    Creator: Hashemi, Seyed Mojtaba
    Description: Irreversible adsorption or heel formation during cyclic adsorption/regeneration of high molecular weight volatile organic compounds (VOCs) onto activated carbon decreases its adsorption capacity and lifetime. The effect of regeneration purge gas oxygen impurity on activated carbon performance, specifically during successive adsorption/regeneration cycles was investigated. 5-cycle adsorption/regeneration tests were performed on microporous beaded activated carbon (BAC) using 11 different aliphatic and aromatic organic compounds representative of VOCs produced from painting booths. Nitrogen with different oxygen concentrations (≤ 5 to 20,000 ppm) was used as regeneration purge gas during thermal desorption of 1,2,4-trimethylbenzene (TMB). Cumulative heel formation increased from 0.5% to 15.4% as the oxygen concentration in the desorption purge gas increased from ≤ 5 ppm to 20,000 ppm, respectively, in case of TMB adsorption. For regeneration of BAC saturated with all other VOCs, nitrogen with two levels of oxygen impurity (≤ 5 ppm and 10,000 ppm) was used as regeneration purge gas. At 10,000 ppm oxygen concentration, the cumulative heel was 0.7-3.2% for aliphatic compounds and 0-13% from for aromatic compounds while at ≤ 5 ppm, it was 0.3-1.3% for aliphatic compounds and 0.0-4.6% for aromatic compounds. Overall, regeneration of alkyl-aromatics was impacted by presence of oxygen in the purge gas to a greater degree compared to aliphatic compounds. Thermogravimetric analysis of the regenerated samples showed desorption of species at high temperatures (400-600°C) which shows that these compounds are strongly attached to the adsorbent surface. The results suggest that the effect of regeneration purge gas oxygen impurities on the irreversible adsorption of VOCs is dependent on the nature of the adsorbate- likely its tendency to react with oxygen. The results from this study help explain the heel formation mechanism and how it relates to regeneration purge gas purity.
    Subjects: Adsorption, Regeneration, Heel formation, Purge gas, Activated carbon, VOC
  3. Novel Methods for Treating Oilsands Tailings [Download]

    Title: Novel Methods for Treating Oilsands Tailings
    Creator: Thompson, Dominic K
    Description: Oilsands tailings are a waste product comprising primarily a stable alkaline suspension of clay in water. This waste product of oilsands mining is environmentally hazardous to store and expensive to safely dispose of. This work presents two novel ideas for dealing with the waste. The first is treatment with alkoxysilanes. Five alkoxysilanes were tested: bis(3-trimethoxysilylpropyl)amine; 3- aminopropyltrimethoxysilane; (3-glycidoxypropyl)trimethoxysilane; methacryloxypropyltrimethoxysilane; and tetramethoxysilane. Of these, bis(3- trimethoxysilylpropyl)amine and 3-aminopropyltrimethoxysilane were found to be effective at reducing Capillary Suction Time. Further tests were conducted with bis(3- trimethoxysilylpropyl)amine, including: 1) optimisation of pretreatment conditions; 2) determination of the effect of carbon dioxide on its performance; 3) determination of its interaction with a conventional polymer flocculant; and 4) investigation of its effect on suspensions with other solids concentrations. The second is treatment with carbon dioxide close to its critical point. This treatment is found to improve measures of dewatering potential, including Capillary Suction Time. No evidence is found for an additional supercritical effect and the mechanism is found to be the well-documented pH reduction.
    Subjects: Alkoxysilanes, Clay, Flocculation, Polymers, Tailings, Oilsands
  4. Open Pit Mine Loading and Haulage Simulation [Download]

    Title: Open Pit Mine Loading and Haulage Simulation
    Creator: Montes Higuita,Luisa F
    Description: The objective of this research is to estimate the main KPI's of an open pit mining truck and shovel operations, while quantifying uncertainty about the KPI's with high statistical confidence. Short-term production scheduling base their estimations on deterministic approaches, but the nature of mining operation is variable, so when execution of the plan comes, it faces a reality different to what it forecasts. The main contribution of this thesis is to quantify uncertainty in truck and shovel KPI’s due to operational uncertainties, planned and un-planned maintenance, and weather events with a 95% confidence interval. To achieve the research objectives, a discrete event simulation model for truck and shovel operations is built, verified, and validated against historical dispatch data. The following tasks are completed: a) statistical data analysis of historical dispatch data, b) fitting probability density functions on historical operational data, c) building a truck and shovel simulation model in Arena software, d) adding the preventive maintenance, failures, and weather events into the simulation model for trucks and shovels, e) validation of equipment performances against historical data, f) four different major scenarios are assessed with changing the number of ore and waste trucks and the throughput rate of the crusher to find the near optimal size of the fleet, g) the detail short-term expected production of ore and waste under monthly and weekly time frames are reported along with KPI's for tonnage, time charts, availably, and efficiency. The main contribution of this research is a discrete event simulation model for truck and shovel operations that predicts the major KPIs of a mining operation with 95% statistical confidence about the statistics of interest while quantifying the uncertainty around the estimation.
    Subjects: Mine hauling, Open pit mine discrete event simulation, Truck and Shovel discrete event simulation
  5. Improved Forest Fire Danger Rating Using Regression Kriging with the Canadian Precipitation Analysis (CaPA) System in Alberta [Download]

    Title: Improved Forest Fire Danger Rating Using Regression Kriging with the Canadian Precipitation Analysis (CaPA) System in Alberta
    Creator: Cai,Xinli
    Description: Estimating precipitation is currently one of the key challenges of accurate Fire Danger Rating. New gridded precipitation analysis systems such as the Canadian Precipitation Analysis System (CaPA) may be superior to the current analytical interpolation strategies, thin plate spline (TPS), and inverse distance weighting (IDW). To compare the performance of CaPA and interpolation methods in the forested area of Alberta, I evaluated precipitation estimates from CaPA and 17 algorithms of five interpolation methods, including IDW, smoothed TPS, non-smoothed TPS, ordinary kriging, and regression kriging. Precipitation estimates were generated using station observations through leave-one-out cross-validation and were evaluated using a range of skill scores (MAE, Bias, ETS, and FBI). I also assessed impacts of these precipitation estimates on the Canadian Forest Fire Weather Index (FWI) System and examined the impacts of weather station density on model performance. Results show that CaPA was only a mid-tiered method (13th of 18), except in Doppler radar covered areas, where CaPA performed second best. Regression kriging (with CaPA as a covariate) was the best method and produced precipitation estimates with 19.6% lower MAE compared with IDW. I found that the best method shifted with station density; CaPA was the best method when fire weather station density fell below 0.6 stations per 10 000km2 while regression kriging was the best method above this threshold. Additionally, this study showed that the FWI System responded to precipitation estimates differently due to their varying drying time lag of the indexes. Quick drying indexes (FFMC, ISI, FWI) preferred methods with lower MAE (e.g., regression kriging with smoothing), while slow drying indexes (DMC, DC, BUI) preferred methods with lower Bias (e.g., regression kriging without smoothing). Overall, I recommend the use of regression kriging with CaPA as a covariate to estimate fire danger across landscapes.
    Subjects: Regression kriging, Canadian Precipitation Analysis (CaPA), Fire danger rating, Interpolation
  6. Integration of Anaerobic Digestion and Composting Facilities [Download]

    Title: Integration of Anaerobic Digestion and Composting Facilities
    Creator: Arab, Golnaz
    Description: Interest in organic waste treatment has increased in recent years due to growing rate of organic waste generation. Implementing biotransformation technologies helps to divert organic waste from landfill, reduce greenhouse gas emission, and produce valuable final products. This research was conducted in two parts. The general goal of the first part was to extend the overall knowledge in organic waste characterization, generation rate, sources, and sampling. While in the second part, which is the main part of the dissertation, the focus was on anaerobic digestion and composting processes and integration of these two biotransformation technologies. In the first part (Chapter 2), a sampling methodology was proposed for higher education institutions (HEI’s), as one of the main generators in institutional, commercial, and industrial (ICI) sectors. Representative organic waste was collected according to the proposed methodology and characterized in terms of their physical, chemical, and biological properties. In the second part, different options of digestate post treatment were investigated in an integrated anaerobic digestion and composting system. Co-composting of digestate and organic fraction of municipal solid waste (OFMSW) was studied in terms of physicochemical parameters and microbial population dynamics in Chapter 3 and 4, respectively. Digestate was prepared by running a high solid anaerobic digestion (HSAD) reactor with the working volume of 500 L. Then it was mixed with OFMSW in eight different mixing ratios; 0, 10, 20, 30, 40, 50, 75, or 100% (wet mass). Composting reactors with working volume of 25 L were monitored for 100 days including 30 days of aeration and 70 days of curing. Monitored parameters were temperature, mass changes, total solids, organic matter, pH, and electrical conductivity. Stability and maturity endpoints were also quantified by running respirometry, C:N ratio, ammonium to nitrate ratio, and Solvita® tests. The results revealed that the reactors with 20 to 40% (%ww) digestate had better performance in terms of organic matter (OM) removal, temperature evolution, and also stability time. Results also showed that total ammonia nitrogen (TAN) available in the digestate could be an effective parameter in organic matter degradation and composting performance. Concentration above 5000 TAN mg.kg-1 DM found to be unfavorable for the biological activities where the improvement in composting performance was observed in the lower concentrations of TAN. OFMSW could also enhance the physicochemical properties of the digestate by balancing free air space, moisture content, and C:N ratio parameters. Simpson index calculated from pyrosequencing results also showed that microbial diversity was higher in the reactors with better performance. Proper mixing ratio of the digestate and OFMSW, 20 to 40%, (%ww) probably provided the most favourable condition for bacteria and fungi activities. Higher relative abundance of the two bacterial phyla, Thermoactinomycetaceae and Actinomycetales, in the reactors with 20 to 40% digestate indicated a potential of high efficient and rapid composting. In the fungal community, Galactomyces, Pichia, Chaetomium, and Acremonium were the four genera probably involved in higher OM degradation in the reactors with better performance. In Chapter 5, co-composting of polished digestate and composted OFMSW was studied as another option for further treatment of digestate. 8-day aerated digestate was mixed with composted OFMSW in eight different mixing ratios; 0, 20, 30, 40, 50, 60, 80, or 100% (wet mass) as feedstock for the curing process. Curing process was monitored during 100 days, with the same physicochemical analyses applied in the previous options. The results demonstrated that the two main feedstocks could not take advantages of each other and composting performance decreased when the digestate portion increased. This could be due to loss of N during aeration of the digestate and/or inappropriate inoculation time. Overall, comparing all the investigated options demonstrated that co-composting of the digestate and OFMSW with the mixing ratio of 20 to 40% was associated with higher OM degradation, higher temperature generation, and shorter stability time. Therefore co-composting of digestate with the OFMSW is suggested as a reliable and robust method for further treatment of the digestate.
    Subjects: Anaerobic digestion, composting anaerobic digestate, Integration of anaerobic digestion and composting, composting
  7. Acoustic and elastic least-squares two-way wave equation migration with exact adjoint operator [Download]

    Title: Acoustic and elastic least-squares two-way wave equation migration with exact adjoint operator
    Creator: Xu, Linan
    Description: A major problem in exploration seismology entails estimating subsurface structures and properties via linearized inversion. The problem is often called ''least-squares migration" where seismic imaging is posed as an iterative least-squares problem. The iterative solution employs the method of conjugate gradients which requires two operators: the forward operator and the adjoint operator. This thesis investigates the design of the forward operator and its associated exact adjoint for both acoustic and elastic least-squares migration. The forward operator is derived using the Born approximation and Green's functions of the two-way wave equation. A few key steps were followed to obtain an adjoint operator that has the exact adjoint formulation of the forward operator. I first derive the Born approximation and discretize Green's functions using the finite difference method, where I have adopted a staggered grid algorithm with stepping in the time domain. Then, a simple workflow was used to describe the discrete forward operator in terms of the concatenated multiplication of matrices. Finally, the exact adjoint operator is obtained by taking the transpose of the discrete forward operator. The adjointness of the forward and adjoint operators can be verified by the dot product test. Unlike the conventional adjoint operator derived via the discretization of continuous kernels, I observe that the proposed exact adjoint operator can pass the dot product test in machine precision, which implies that the forward and the proposed adjoint operator achieve sufficient accuracy to use conjugate gradients to solve the aforementioned problem of least-squares migration. While the forward and exact adjoint operators are derived in the form of matrices, creating explicit matrices in numerical solvers does not provide a memory-efficient implementation. To deal with this memory issue, a matrix-free programming process is applied to develop the forward operator and its exact adjoint operator. Preconditioning operators are also investigated to solve the least-squares migration for extended shot-index images efficiently. Finally, the proposed method is tested via synthetic examples. Compared with conventional migration techniques, least-squares migration (both acoustic and elastic) is capable of attenuating low-wavenumber artifacts, compensating for insufficient illumination, and increasing the resolution of seismic images. Elastic least-squares migration provides an additional benefit of suppressing multi-parameter cross-talk.
    Subjects: Thesis, Exact adjoint, Wave equation, Acoustic, Conjugate gradients, Least-squares migration, Elastic, Inversion
  8. Experimental Investigations for SAGD Well Integrity Numerical Modelling [Download]

    Title: Experimental Investigations for SAGD Well Integrity Numerical Modelling
    Creator: Li, Xiangyu
    Description: Steam-Assisted Gravity Drainage (SAGD), today is the most promising technique to extract heavy oil from oil sands reservoirs. Maintenance of integrity of the near-well area is crucial to help ensure that the reserves are produced properly without environmental or production optimization challenges. The research presented here addresses the geomechanical effects associated with SAGD on wellbore integrity. The output of this research can be used in coupled hydraulic-geomechanical numerical simulation platforms for assessing the possible displacement ranges of wellbores within the steam chamber in the large reservoir model. The thesis consists of two parts. In the first part, the hydro-mechanical behavior of Wabiskaw formation located in the SAGD reservoir production site in Canada is experimentally analyzed through consolidation and steady state flow tests. Pressure-dependent compressibilities and Biot coefficients were also obtained from the caprock testing strategy. Significant ‘creep’ behavior was observed during the experiments process. Several possible microscale processes are presented and discussed. In the second part of the thesis the permeability of well cement is characterized through a hydraulic pulse test technique. This work includes: laboratory testing system design, construction and calibration. A parameter identification method based on a previously published analytical solution which describes the pulse behaviour was used to obtain the best estimates of the cement permeability and specific storage. The validity of the technique is evaluated with 22 separate measurements on one well cement sample. The pulse test successfully estimates the cement permeabilities which are in good agreement with steady state flow results. A simple method to interpret the pulse test data is also included in the thesis, and the results were compared with the analytical solution. Numerical simulations of the cement pore pressure decay response generated with the numerical code COMSOL are presented as well.
    Subjects: Well Integrity, Pulse Test, SAGD, Consolidation
  9. Field Behavior of Steel Threaded Micropiles under Axial Loads in Cohesive Soils [Download]

    Title: Field Behavior of Steel Threaded Micropiles under Axial Loads in Cohesive Soils
    Creator: Guo, Zhengyang
    Description: Steel threaded micropiles are a new deep foundation system recently introduced to the piling industry of North America. This pile consists of a steel threaded tubular shaft that is tapered at the lower segment. Steel threaded micropiles are quick to install, easy to dismantle, and have been increasingly used to support new and existing structures. Therefore, it is important to study the performance of steel threaded micropiles installed in different soil types subject to various loading conditions. Although conventional micropiles have been investigated in a limited number of studies, there is not any study of the axial performance of steel threaded micropiles. Field tests of steel threaded full-scale micropiles with the diameter varying from 76 mm to 114 mm and length varying from 1.6 m to 3 m were carried out to investigate the axial bearing capacities, the load-transfer mechanism, the torque mechanism, and the axial cyclic response of the piles. Two cohesive soil sites were selected for the field tests: University of Alberta South Campus Site and Sherwood Park Site. Comprehensive site investigations including cone penetration tests (CPT), Shelby tube soil sampling, and laboratory tests were carried out for both sites. At the South Campus site, forty load tests were performed on piles subject to static axial compressive and tensile loads. Four test piles were instrumented with several strain gauge stations. Results showed the piles behave as frictional piles and reached the limit state before the displacement exceeded 10% of the pile diameter. The adhesion coefficient of the top smooth shaft at limit state was less than 0.1. The failure mode along the cylindrical threaded shaft was confirmed to be cylindrical shearing along the edge of the threads; the threads increased the axial capacities of the segment. Axial capacities of the threaded tapered segment were 43% on average greater than that of a cylindrical segment with the equivalent volume. Compressive capacities of all test piles were estimated based on preceding load-transfer mechanism and the results agreed reasonably well with the measured capacities. A theoretical torque model was proposed to estimate the end installation torques using the CPT-based remolded soil strength; the results matched the measured end torques very well. At the Sherwood Park site, twenty-five axial monotonic load tests and three axial cyclic load tests were performed. Three tests were instrumented with five strain gauge stations to investigate the unit shaft resistance development during the monotonic and cyclic loading. Results showed that the piles behave as frictional piles and skin friction is mobilized when the displacement reaches 5% to 10% of the pile diameter during monotonic load tests. With the similar installation torques, the compressive capacity of all test piles is greater than tensile capacity by an average of 27%. When subject to vertical earthquake loading, the steel threaded micropiles underwent acceptably small cumulative displacements of less than 2 mm. The magnitude of the cumulative displacement decreased with the pile length and pile diameter. Cyclic loading redistributed the load transfer along different segments of the pile and the negative skin friction was developed along the smooth pile shaft when the pile underwent decreasing axial loading. No degradation of pile axial stiffness was observed for the three piles tested under the range of applied cyclic loading.
    Subjects: foundation, field behavior, cohesive soil, micropiles, axial load
  10. Analysis of Canadian Train Derailments from 2001 to 2014 [Download]

    Title: Analysis of Canadian Train Derailments from 2001 to 2014
    Creator: Leishman, Eric M
    Description: Rail transportation is a vital component of Canada’s economy, with great distances separating urban centres. Disruptions to rail service can have costly implications, not only in terms of monetary loss, but also to the environment, the public and railroad employees. Derailments account for a large number of these disruptions, and are caused by a number of factors. This study investigates long term trends in the number of derailments on Canadian railways from 2001 to 2014, with a focus on main track rail. The total number of derailments are considered, as well as just those that involved dangerous goods cars. To reflect changes in rail traffic volumes over the study period, these trends are normalized against gross tonne-km of goods transported. Another area of focus of this research was to determine the leading causes of derailments, and to assess both frequency and severity for these causes. It was expected that a number of causes would show some degree of seasonality, with subgrade issues more common in the summer and mechanical issues more common in the winter. Spatial trends were developed based on the physiographic regions of Canada to assess the effects of physical geography on the safe operation of railways. Four of the leading derailment causes were selected for this analysis. This analysis accomplished by analyzing data from two primary sources. Derailment data was obtained from the Railway Occurrence Database System, a database of Canadian rail incidents maintained by the Transportation Safety Board of Canada (TSB). An abbreviated version is publicly available on-line, but a more extensive database was provided for this study by the TSB. This database contains information on all types of rail incidents that are self-reported by the railway operators. Rail traffic data was obtained from publicly available tables on the Statistics Canada website. A decreasing trend in main track derailments, as well as the subset of derailments with dangerous goods cars involved, was observed from 2001 to 2014. During this time period, it was found that the cause associated with the greatest number of derailments was the “rail, joint bar and rail anchoring” incident cause, followed by “track geometry,” “environmental conditions” and “wheels.” These four causes were included in the seasonal and spatial analyses, and it was observed that derailments due to rail and wheel breaks were more common in the winter, while derailments attributed to subgrade and track geometry issues were more common in the summer. Spatially, a higher number of derailments occurred in the Cordillera, Interior Plains and Canadian Shield regions, while comparatively few occurred in the St. Lawrence Lowlands and Appalachian regions. Decreasing or relatively consistent trends were observed in each region.
    Subjects: derailments, canada