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2020 — Customer Sentiment Analysis in Arabic Social MediaRésumé
Performing sentiment analysis on text document is an active research area. Social media includes valuable information resources in various languages, which encompass reviews, comments, tweets, posts, opinions, articles and other text resources. These could be analysed to explore people’s opinions, attitudes, emotions and sentiments toward various subjects and commodities. Hence, this thesis targets customer sentiment analysis in Arabic social media, with a focus on both the real estate and automobile industries. In this regard, automated analyzer systems were proposed in this thesis, to classify the sentiment polarity of each social media customer feedback review into “positive”, “negative” or “mixed”. This … Lire la suite
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2013 — Identifying Structure and Semantics in Bayesian Network InferenceRésumé
Bayesian networks are a semantic modeling tool for managing uncertainty in complex domains. While the numerous techniques for exact inference vary when they apply the multiplication and marginalization (addition) operators, they all center around eliminating variables. These inference algorithms start and end with clear structure and semantics, yet all intermediate distributions, whether normalized or unnormalized, are denoted as potentials. In this thesis, we reveal the structure and semantics of the intermediate factors constructed during exact inference in discrete Bayesian networks. Our discussion is primarily based on Variable Elimination (VE), which is a standard approach to Bayesian network inference. We first … Lire la suite
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2014 — A Preliminary Investigation of Possible Occurrences of Transition Zones and Residual Oil Zones Below Oil-Water Contact in Matured Oil Fields, Southeast SaskatchewanRésumé
A transition zone (TZ) from oil to water formed by capillary force beneath traditionally defined producing oil-water contact (OWC) has been well known for years. Recent research and production activities in the Permian Basin and the Williston Basin in United States have revealed that under certain geologic and hydrodynamic conditions, a residual oil zone (ROZ) may exist below the traditional producing OWC with stranded oil that may be economically recoverable using tertiary recovery techniques (Koperna and Kuuskraa, 2006; Trentham, et al., 2012). The ROZ could be thick, extensive, and containing a significant amount of oil. ROZ is usually thought having … Lire la suite
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2020 — Experimental And Simulative Studies For Evaluating Desorption Performance With Blended Amine Solvents In Post-Combustion CO2: Capture SystemsRésumé
Desorption is a very important process to liberate CO2 from CO2 saturated rich solution by adding thermal energy provided by a reboiler. This process should be studied very seriously for improving economic efficiency because fresh solvent for every cycle of capture is very expensive and also up to 70% high energy consumption is required for solvent regeneration procedure. The objective of this research was to evaluate the desorption performance using reactive aqueous MDEA/PZ blends and aqueous MEA/MDEA/PZ experimentally in a bench-scale packed column and compared with the benchmark aqueous 5M MEA solution in terms of cyclic capacity, rate of desorption, … Lire la suite
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2025 — Experimental Evaluation of Innovative Catalytic Heat Exchangers for Energy-efficient Amine-based Post-combustion CO₂ Capture ProcessesRésumé
This PhD research focused on enhancing CO2 desorption performance in post-combustion carbon capture processes by developing and optimizing catalytic heat exchangers. The guiding principle was to address challenges, including operational complexity and high energy consumption, while minimizing costly modifications to existing piping and infrastructure in pilot plants. The feasibility of novel aqueous piperazine-based biphasic solvents was initially investigated to reduce solvent flow rates and optimize heat exchanger size. Although these solvents demonstrated promising absorption and desorption performance, challenges such as high viscosities, suboptimal phase split ratios and low amine concentrations in the rich phase limited their applicability in the catalytic … Lire la suite
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2017 — Experimental and Theoretical Studies on Foam Flooding in Tight ReservoirsRésumé
Enhanced oil recovery for tight reservoirs with extremely low permeability and porosity is becoming the new routine for reservoir engineering research. Foam flooding has already been proven as an effective and potential approach to enhance the oil recovery in conventional reservoirs. However, limited research has been done on the phenomena and mechanism of foam performance in tight porous media. In this study, both experimental and theoretical approaches are utilized to study the foam flooding process in tight reservoirs. In the experimental part of this study, a series of core flooding tests are performed to investigate foam performance in the absence … Lire la suite
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2021 — Modelling and Experimental Investigation of Foam Displacement in Pore NetworksRésumé
Foam is a complicated but fascinating fluid being widely involved in almost every technological step in petroleum industry, from drilling, well stimulation, enhanced oil recovery (EOR), production, to refining process. Its instability and unique rheology make foam one of most complicated fluids encountered in petroleum industry. From the perspective of applied science, foam is formed in-situ while gas flow being made discontinuous by thin liquid film called lamellae. Yield stress-like resistance exerted on discontinuous gas phase makes it temporarily immobile in-situ. Continuing lamellae generation, thinning, and rupture accompany with non-linear displacement of foam in porous media. These features make foam … Lire la suite
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2018 — Methane Absorption Characteristics on ShaleRésumé
In order to supply sufficient energy to meet demand, the exploration and development of the relatively rich shale gas reservoirs in China are areas of recent research focus. In the isothermal methane adsorption experiment, we investigated different types of shale from the Yanchang Formation in the Zhangjia Tan area in the southeast Ordos Basin in China for organic shale gas exploration. The results show that the measured total gas adsorption amounts of Samples 5 and 6 linearly increase with pressure increases, and the total adsorption amounts of other samples first rapidly increase and then slowly increase and trend to a … Lire la suite
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2016 — Determination of Selected Pesticides and Degradation Product in Atomospheric Samples in the Okanagan Valley by Gas Chromatography-Mass SpectrometryRésumé
In this study an optimized gas chromatography negative chemical ionization mass spectrometry method was developed for analyses of target pesticides including chlorpyrifos, diazinon, endosulfan (α- and β isomers), gamma-hexachlorocyclohexane, malathion, pentachloronitrobenzene and endosulfan’s degradation product endosulfan sulfate. Chromatography was performed on a DB-5 MS + DG column with helium as mobile phase. Method detection limits ranged from 1.0 to 4.0 pg/μL for the target pesticides. This study provided the first detection of all the selected pesticides in atmospheric samples collected at Osoyoos, British Columbia. Of the organochlorines, the highest atmospheric concentrations in 2011 and 2012 were observed for α-endosulfan. The … Lire la suite
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2013 — Integration of Numerical Simulation and Wireline Formation Testing Measurements for Permeability InterpretationRésumé
Wireline formation testing (WFT) has gained increasing popularity in the oil and gas industry in the last two decades because of its economical and environmental benefits. Recently, there has been growing interests in using the WFT pumpout transient data to interpret formation permeability and productivity with the conventional pressure transient analysis (PTA). Such an interpretation is based on the assumption of perforating the entire pay zone interval, though it is suspected not to be the case in reality, especially in thick formations where a limited section is sensed by a WFT probe. As for the laminated formations, one challenge to … Lire la suite
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2013 — Performance Evaluation of an Enhanced Cyclic Solvent Process (ECSP) for Thin Heavy Oil ReservoirsRésumé
Canada’s energy future depends on heavy oil resources, which are mainly located in Western Canada, i.e., Saskatchewan and Alberta, and account for almost half of the total world heavy oil reserves. At present, only 8-9% of the original oil in place (OOIP) can be recovered in such heavy oil reservoirs with the current available technology because the oil is very viscous and contained in thin formations. It has been found that cyclic steam stimulation and steam-assisted gravity drainage (SAGD) and vapour extraction (VAPEX) often do not work for recovering heavy oil in such thin reservoirs. The enhanced cyclic solvent process … Lire la suite
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2023 — Ensemble-based framework and its applications to characterizing growth and propagation dynamics of wormhole networks and steam chambers in a heavy oil reservoirRésumé
As for the enormous heavy oil resources all over the world, cold heavy oil production with sand (CHOPS) technique has been successfully utilized to exploit them as the primary recovery due to the induced high-permeability channels (i.e., wormholes) together with foamy oil flow, while the steam-assisted gravity drainage (SAGD) process has been widely used as an efficient enhanced oil recovery (EOR) method because of the steam chamber propagation together with viscosity reduction and gravity drainage. Numerous efforts have been made to characterize the growth and propagation dynamics of wormhole networks and steam chambers; however, it is still a challenging task … Lire la suite
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2013 — BIOWINTM Modeling of the Startup of an Anaerobic Digester Used in Wastewater Treatment PlantsRésumé
Anaerobic digestion involves biochemical and physiochemical processes. It is an effective process for sludge stabilization and methane gas production. However, the digester capacity decreases with time due to the buildup of solid deposits at the bottom of the digester. Therefore, routine shutdown and cleanup are commonly practiced at Wastewater Treatment Plants (WWTPs). Currently, WWTP operators face the challenge of starting up an anaerobic digester in a timely, cost-effective manner with effective methane gas production. This challenge can be addressed by computer modeling and simulations of different operating conditions, which is a cost-effective solution in comparison to experimentation. In this research, … Lire la suite
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2015 — Analysis of Longitudinal Data With Missing Responses: A Study of Pain Control CostRésumé
Recent years have seen a major increase of interest in pain control cost studies. Due to rising costs of medical treatment, researchers study factors contributing to cost and appropriate ways to control or reduce the cost of pain control. The first data studied in this research is longitudinal data with cost values completely missing. We fill in the daily cost for minority observations based on the information provided by the price data, and then impute the daily cost for the remaining observations by applying multiple imputation. Multiple sets of complete imputed daily cost data are produced. A generalized estimating equations … Lire la suite
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2021 — A New Dynamic Fluid Flow Method for Studying the Phase Changes of the Light/Heavy Crude Oil-Solvent SystemsRésumé
In this thesis, a novel experimental method, namely, the dynamic fluid flow (DFF) method, was developed to study the phase changes of various light/heavy crude oil‒solvent systems. First, two series of constant-composition-expansion (CCE) tests and constant-composition-expansion and compression (CCEC) tests were conducted by using a pressure‒volume‒temperature (PVT) system. Second, a series of the DFF tests were undertaken to measure the pressure gradients along a long micro-tubing at different outlet pressures when a given light/heavy crude oil‒solvent mixture flowed at a constant volume flow rate. For the light crude oil‒CO2 systems, it was found that the pressure gradient remained low and … Lire la suite
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2013 — Modeling of Multi-Stage Fractured Horizontal WellsRésumé
Horizontal wells stimulated by multiple fractures unlock tight formations and shale gas reservoirs that used to be considered as uneconomic plays. However, the popularity of such techniques presents new challenges to the reservoir and fractures evaluation. Fractured horizontal wells’ pressure and production rate behaviour exhibit complex trends that are quite different from previous horizontal and fractured vertical wells. To facilitate the pressure and rate analysis, this work developed semi-analytical models under different assumptions and comprehensively described the fluid flow of a multi-stage fractured horizontal well in a bounded reservoir. The governing Partial Differential Equations (PDEs) in this work are highly … Lire la suite
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2019 — Modeling The Fluid Flow in Low-Permeability Unconventional Reservoirs Across ScalesRésumé
In the last decade low-permeability unconventional reservoirs (i.e., shale and tight formations) become an increasingly important source of oil and especially gas supply in the world. Low permeability reservoirs are characterized with small grain sizes (m), low permeability (< 0.1mD), small porosity (<10%) and high total organic carbon (TOC) (0.8-20wt%). The productivity of shale and tight reservoirs heavily depends on the interaction between reservoir rock matrix and multi-stage fractured horizontal wells (MFHWs). To predict and optimize unconventional reservoirs’ production behavior, this study tries to model the fluid flow across scales-from the pore scale to the reservoir- scale. Shale matrix … Lire la suite
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2021 — Lead Corrosion Investigation and Control in the Drinking Water Distribution System in Several Cities in CanadaRésumé
Drinking water is the fundamental element for the human to live. The quality of drinking water will significantly influence human health. However, some heavy metals such as lead, arsenic, cadmium, copper, and iron etc. in the drinking water have been reported to exceed the regulation. Due to the adverse effect of heavy metals on the health of human beings, heavy metal corrosion control becomes more and more critical and has attracted the attention of many researchers. In 2019, the Health Canada guideline of lead concentration for drinking water in Canada decreased from 10 𝜇g/L to 5 𝜇g/L. Many Canadian cities … Lire la suite
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2015 — “Tawny Grammar”: Anne Simpson’s Exploration of the OtherRésumé
This study examines the poetry of Anne Simpson. Given that there has been no full-length study of her poetry, the thesis deals heavily in close readings of poems from all four collections: Light Falls Through You, Loop, Quick, and Is. Developing the term “tawny grammar,” used in her essays, I explore how this altered language requires Simpson’s poetry to develop “tawny” poetic forms and “tawny” movements of perspective. The shifting and unstable nature of the “tawny” allows Simpson’s poetry to address the Other, particularly the violent experiences of Others, in an ethical way. I suggest that Simpson’s punctuation, form, and … Lire la suite
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2018 — A Comparative Study of Silicified Rock Reservoir in Shunnan 4 well of Tarim Basin with Hydrothermal Chert Reservoir of Parkland Gas Field in Western Canada Sedimentary BasinRésumé
The silicified limestone reservoirs in the Yingshan Formation of Middle Ordovician, discovered from SN4 well in 2013, have made a high yield in Shunnan area which is located in the center of Tarim Basin, northwest China. Comparing to previous work about the silicificaition, much more detailed petrographic descriptions have been carried out in this study. The most important diagenetic features to the silicification are identified including replacement quartz, quartz cement (characterized by 4 textures: equant quartz, bladed quartz, overgrowth and quartz cement in later fractures) and three types of calcite cement (CC1-CC3). Geochemical analysis including Si-O isotope analysis on quartz … Lire la suite
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2024 — Nanocellulose-based materials for sustainable soil remediation and water purificationRésumé
Soil and water pollution are intricately linked environmental issues that have gained significant global attention due to their adverse effects on ecosystems, public health, and overall sustainability. In this dissertation, the pressing need for sustainable pollutant treatment using ecofriendly and biodegradable nanocellulose (CNC) biopolymers is addressed. This research focuses on the development of CNC-based materials, characterization of their adsorption behaviors, evaluation of CNC-mediated algal toxicity, and exploration of the application of the these materials in sustainable soil remediation and water purification. In the first part, the utilization of CNC nanofluid as an eco-friendly agent for the remediation of phenanthrene (PHE) … Lire la suite
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2013 — Diagenetic Evolution of the Middle Devonian Stone and Dunedin Formations of the Liard Basin, Northeast British ColumbiaRésumé
The Middle Devonian Stone and Dunedin formations are correlative to the Chinchaga and Keg River formations in Northwest Alberta, as well as the Headless and Nahanni formations in Southern Yukon. Core study has identified twenty carbonate sedimentary facies in the Stone and Dunedin formations. The lower to middle Stone Formation comprises of a subtle vertical facies transition from intertidal mudstones to lagoonal wackestones and amphiporid floatstone. The upper Stone Formation in c-10-E/94-N-7 comprises of dominantly clast-rich silty dolomudstone to silty dolomudstone, which is interpreted to have deposited in peritidal settings and represent the middle Chinchaga depositional break caused by the … Lire la suite
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2018 — Genetic mechanisms contributing to antimicrobial resistance: gene repression in Mycobacterium, gene transfer in Salmonella, and phage sensitivity in EscherichiaRésumé
Bacteria develop resistance to antimicrobial agents through genetic mutation or horizontal acquisition of genetic material from resistant cells. Mycobacterium, Salmonella, and Escherichia are all capable of causing disease, and each demonstrates increasing resistance to conventional antibiotic treatment. Understanding the genetic mechanisms that regulate antibiotic resistance are critical in developing new antimicrobials and improving current treatment regimens. Alternative therapies to antibiotics should also be considered in the fight against multidrug resistant pathogens. Thus, I carried out molecular studies to investigate the regulation of efflux pump expression in Mycobacterium intracellulare, regulation mechanisms of natural competence in Salmonella Typhimurium, and phage therapy of … Lire la suite
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2016 — Using Conflict and Support Counts for Variable and Value Ordering in CSPsRésumé
A Constraint Satisfaction Problem (CSP) is a very powerful framework for representing and solving constraint problems. Many real world computational problems in Artificial Intelligence and other areas of computer science can be formulated as CSPs. Problems such as scheduling and timetabling in operations research, map-coloring problem and Boolean satisfiability are some of the examples that can be represented and solved with a CSP framework. Solving a CSP is about searching for a solution in a huge search space. Very often, much search efforts are wasted on the part of the search space that does not lead to a solution. Therefore … Lire la suite
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2019 — The long-delayed repatriation of the Sakhalin Koreans: Cold war challenges and resolutions, 1945-1992Résumé
During World War II (WWII), tens of thousands of Koreans were forcibly mobilized to Karafuto (southern Sakhalin Island) to serve as labourers in Japan’s wartime economy. When the war ended in August 1945, the Soviet Union occupied the region and the Koreans ceased to be Japanese colonial subjects. While 99% of the Japanese in Karafuto were repatriated by April 1950, the Koreans became trapped in a Cold War standoff between the Soviet Union, North Korea, and South Korea that was not fully resolved until the 1990s. As such they became double victims of global forces that paid little heed to … Lire la suite