Faculty of Graduate Studies Online Theses
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Item Open Access Numerical Study of Interactions between surface waves, currents and hydrography in extreme weather conditions(2025-01-15) Hughes, Colin; Yes; Doctor of Philosophy; Department of Oceanography; Not Applicable; Oliver Fringer; Yes; Ian Folkins; Michael Dowd; Jinyu Sheng; William PerrieSurface gravity waves significantly affect air-sea interactions, turbulent vertical mixing, ocean currents and hydrography in the upper ocean, particularly during extreme weather events such as hurricanes and winter storms. Currents in the upper ocean also influence surface waves via the Doppler shift, relative wind effect, refraction and advection. This thesis examines the impact of wave breaking (WB), Langmuir turbulence (LT) and conservative wave effects on the upper ocean dynamics and effects of currents on surface waves during hurricane conditions using a coupled circulation-wave model. The wave-current interactions (WCIs) are investigated numerically in two cases using (a) idealized hurricanes moving at three translational speeds and (b) Hurricane Arthur (2014) over the northwest Atlantic Ocean. Model results in the fully coupled run are examined in comparison with results in other runs in which wave effects are selectively disabled to quantify main physical processes of WCIs, with a special focus on wave-induced changes to the upper ocean turbulent kinetic energy (TKE), thermal structure and currents. For the case of idealized hurricanes, analyses of model results reveal that LT has a larger impact on upper ocean currents, temperature and TKE, compared to the other considered processes. The combined wave effects reduce the surface currents in the front two quadrants of the hurricane and enhance the cold wake and near-surface cooling, predominantly to the right of the storm track. For the case of Hurricane Arthur, both the LT and WB driven acceleration are found to be important to storm-induced changes in the upper ocean temperature and circulation. By contrast, the WB induced surface flux of TKE has a limited effect on the temperature, salinity and currents in the surface layer. Over pathways of the Gulf Stream, the large WCIs reduce the significant wave heights (SWHs) of surface waves during Hurricane Arthur, with the biggest differences occurring to the right of the storm track. SWHs on the left hand side of the storm are limited by the shorter fetch, shallower water depths and coastline.Item Open Access A City Transformed? Urban Development and the Role of Canadian Railway Policy in Halifax, Nova Scotia, 1900-1920(1992-03) Hodgins, Murray B.; Not Applicable; Master of Arts; Department of History; Not Applicable; unknown; Not Applicable; David Sutherland; Henry Roper; Michael CrossThis thesis analyzes the development of the city of Halifax in the first two decades of the twentieth century, emphasizing the themes of suburban growth, the rise of municipal boosterism, and the drive for industrial development. During this period the notions of privacy and autonomy of the traditional leadership of Halifax were challenged by Ottawa's decision to build a modern wharf and rail complex in the heart of Halifax's genteel south end. This challenge and the responses it generated within the city's business elite, civic administration, and Civic Improvement League, a group committed to the planned and orderly development of the city, provide an opportunity to explore major elements of the city building process in post Confederation Atlantic Canada. The federal design, a massive departure from the existing course of development, was announced as a fait accompli. Fear of the project's vulnerability to political opposition compelled the booster element in the business elite to support the proposal as presented, despite the fact that the elite residential district would be destroyed. The municipal administration and the Civic Improvement League yielded to pressure and "rubber stamped" elite approval of the project. The League rose to assume the role of advocate for the city's interests, and used this position to continue its pursuit of comprehensive planning and orderly development. Its progressive goals were reduced to the enactment of protective zoning legislation for the residential area, however. The decline in national economic fortunes after 1913, and the onset of post-war economic deflation in 1921, slowed the city's growth to a halt. This decline rendered obsolete the optimistic projections behind the Ocean Terminals, and left the city of Halifax with a large, federally-controlled transportation complex in its formerly proud south end.Item Embargo TREATMENT PERFORMANCE ASSESSMENT AND MODELING OF A SOIL-BASED WASTEWATER TREATMENT SYSTEM IN NORTHERN CANADA(2025-01-14) Carvalho Boratto, Débora; Not Applicable; Master of Applied Science; Department of Civil and Resource Engineering; Not Applicable; n/a; Not Applicable; Dr. Lauren Somers; Dr. Azadeh Kermanshahi pour; Dr. Rob Jamieson; Dr. Barret KurylykWastewater treatment in northern communities is an ongoing challenging. This research focused on the performance assessment and modeling of a passive soil-based wastewater infiltration system in Fort Good Hope, Northwest Territories. A combination of year-round site-specific field data and physically-based numerical modeling of subsurface contaminant transport was used. The investigations reveal that site conditions allow satisfactory system performance despite harsh operating routines, with accumulation of nitrate in groundwater being the most prominent concern. Wintertime conditions have a significant impact on the system’s hydrodynamics and microbial community structure. Model results indicate that an improved effluent distribution system would be required to avoid system failure from excessive mounding in more restrictive scenarios. Atypical operation routines can exhibit advantages from a hydraulic perspective but decrease pollutant removal efficiency compared to conventional procedures. Ultimately, the research findings contribute to addressing knowledge gaps related to the use of soil-based wastewater treatment systems in northern regions.Item Embargo Autonomous Landing of an Unmanned Aerial System on Water in an Unknown Sea State(2025-01-12) Taylor, Connor; Not Applicable; Master of Applied Science; Department of Mechanical Engineering; Not Applicable; n/a; Not Applicable; Dr. Guy Kember; Dr. Clifton Johnston; Dr. Mae Seto; Dr. Robert BauerUnmanned aerial systems (UAS) are used in the marine and oceans environment for a variety of purposes. In this thesis, an approach is taken to enable safe and reliable autonomous landing of a UAS on the water's surface in an unknown sea state. With a UAS capable of landing on the water's surface under a range of sea state wave conditions, the types of mission that a UAS can undertake in marine and oceans environments will be expanded. In this work, it is assumed the UAS has no prior information of the water surface wave characteristics at the landing spot. Therefore, algorithms were developed to enable the UAS to determine the dominant wave period, significant wave height, and mean wave propagation direction in-situ using range measurements with onboard range sensors. With the desired ocean wave characteristics identified, a method was devised to identify persistent low wave-height segments in the wave field, over a spot, using onboard range sensor measurements. These persistent low wave-height segments provide safe landing windows for the UAS. A staged landing algorithm was then developed to ensure safe and timely autonomous landing of the UAS on the water surface. In addition, an investigation was conducted to determine the efficacy of ultrasonic sensors to measure wave heights when the sensors are in motion and mounted at oblique angles on the UAS. The contributions of this work are: a timely method to identify water surface wave characteristics in situ using range sensor measurements, a means to classify and identify low wave-height segments of a wave field using range sensor measurements, a staged landing algorithm for safe and reliable landing on the water's surface in a sea state, and the analysis of the efficacy of an ultrasonic sensor when mounted at oblique angles to measure water wave heights.Item Open Access Characterizing Pathways of Groundwater Recharge and Discharge in a Geologically and Topographically Complex Watershed(2025-01-06) Dauphinee, Reid; Not Applicable; Master of Applied Science; Department of Civil and Resource Engineering; Not Applicable; na; No; Dr. Barret Kurylyk; Dr. Fred Baechler; Dr. Lauren SomersGroundwater is a critical water source for many Canadian and First Nations communities, but the interactions between groundwater and surface water, and the impacts of climate change on groundwater recharge, are not well understood. This study investigates the Christmas Brook watershed and fault aquifer system, which supplies water to Eskasoni First Nation, Nova Scotia. The goal is to quantify the sources and flow pathways of streamflow and groundwater recharge feeding the pumping wells, informing watershed management. Water sampling, hydrochemical analysis, hydrometric monitoring, and groundwater modeling were used. A total of 134 samples were analyzed for ions, isotopes, and metals. Gauging stations were installed at the highland wetland outlet and lowland watershed outlet. Hydrochemical results show groundwater contributes 27 ± 15% of streamflow at the downstream station. A MODFLOW6 model indicates streamflow infiltration provides 60% of pumping well water, with the remaining 40% from fractured rock recharge.Item Open Access The production and exchange of sperm whale coda vocalizations(2007-09) Schulz, Tyler Michael; Not Applicable; Doctor of Philosophy; Department of Biology; Not Applicable; unknown; Not Applicable; Andy Horn; Alex Hay; Hal WhiteheadThe sperm whale (Physeter macrocephalus) is a highly social animal that exchanges patterns of clicks ('codas') amongst members of long-term social units. Due to the difficulty of assigning codas to individual whales, little was known of the coda production of individuals or the exchange of vocalizations between them. To address this problem, I developed a method for assigning recorded codas to whales using differences in the inter-pulse intervals of clicks. Applying this method to recordings of two social units - one studied off Dominica, the other off the Galapagos Islands - revealed that sperm whales produced codas at regular 3-5 s intervals. Furthermore, whales synchronized their vocal output, resulting in duet-like sequences of overlap exchanges. I suggest that these exchanges affirm social relationships between unit members. The coda repertoires of both studied units were highly redundant, indicating little potential for syntactic communication. Moreover, whales in both units tended to repeat one particular coda type, both in the sequences of individuals and in overlap exchanges. Given that units preferentially associate with other units with similar coda repertoires (i.e. from the same acoustic clan), I suggest that the repetition of a particular coda type functions to bond unit members and/or communicate clan affiliation. Most whales in the Dominican social unit had similar coda repertoires, again suggesting that coda types function to advertize clan identity. However, the repertoires of two whales - a male calf and its mother - differed from those of others in the unit, including each other, suggesting that their repertoires signal individual identity. While adult females in the unit vocalized at approximately equal rates, the calf and a juvenile male vocalized less often. This is likely because they did not engage in overlapping exchanges, interactions that may have a social bonding function unnecessary for males that leave their natal unit. To examine the distance between vocalizing whales, I developed an acoustic array consisting of remotely-piloted vessels. Deployment of the array in the Sargasso Sea in 2004 revealed that sperm whales engaged in overlapping coda exchanges both with nearby and comparatively distant whales. This again supports a social bonding function for overlapping exchanges. The acoustic array was also used to show that the waveform structures of coda clicks, like echolocation clicks, vary with the recording position relative to the orientation of the whale. In summary, this thesis suggests that coda production functions to affirm social bonds between unit members (via coda overlapping and matching), advertize clan identity, and advertize individual identity for animals with an increased need to do so.Item Open Access Management and Control of Hybrid Renewable Energy Systems(2024-12-20) Ali, Gama; Yes; Doctor of Philosophy; Department of Electrical & Computer Engineering; Received; Dr. Ahmed F. Zobaa.; Yes; Dr. Jason Gu.; Dr. Ghada Koleilat; Dr. Timothy Little.; Dr. Hamed AlyThere is a big attraction towards renewable energy sources like wind, solar, and biomass because of concerns about greenhouse gas emissions and the limited supply of fossil fuels. While fossil fuels still comprise much of the world’s energy supply, many countries are moving toward renewable energy to lessen their environmental impact. This dissertation bridges key control, optimization, and decision-making domains to advance renewable energy integration, contributing to the development of sustainable, efficient, and resilient power systems.Item Embargo Assessment of the Validity of Virtual Reality-Based Binocular and Visual Tests in a Strabismus Clinic(2024-12-19) Smeltzer, Emma; No; Master of Science; Department of Clinical Vision Science; Received; Stephanie MacLeod; No; Dr. Bashar Bata; Darren OystreckMany tests of visual function were created decades ago and remain unchanged to this day. Tests may be improved by using virtual reality (VR), because binocularity and digital customization intersect. However, its representation of vision remains to be validated. Four binocular and one visual tests (Worth Four Dot, Bagolini Striated Lenses, Frisby Stereotest, Double Maddox Rod, and Pelli-Robson Contrast Sensitivity) were replicated in VR and compared to the current method. Normal and pathological participants aged 5-61 completed each method and were analyzed pairwise. The VR method of Frisby Stereotest was significantly correlated to its clinical method (0.623, p<0.001). Six-meter results of Worth Four Dot (0.370, p=0.001) and Bagolini Striated Lenses (0.272, p=0.021) were also significant. The 1/3m results were not significant. Requirements of accurate visual function are emphasized in this study. VR’s hardware and software need continued development to provide a more realistic viewing environment for these tests.Item Embargo Quality mapping of potato tuber storage facility using real-time location system, wireless communication and machine vision for improved traceability(2024) Campbell, Colton Al; Not Applicable; Master of Science; Faculty of Agriculture; Not Applicable; Chyngyz Erkinbaev; Not Applicable; Vincent Sieben; Yves Leclerc; Ahmad Al-MallahiThis thesis proposes a novel post-harvest potato tuber storage traceability system designed to enhance quality monitoring and management. The system leverages a real-time localization system (RTLS), wireless communication and machine vision to identify and map the quality characteristics of potato tubers. RTLS experiments, conducted in both controlled laboratory settings and field environments, utilized a 3D grid structure with up to 60 actual tag locations, each generating 100 predicted positions. To further enhance accuracy, a Kalman filter was employed in conjunction with LS and a Support Vector Regressor, achieving a total Root Mean Square error (RMSE) as low as 0.183 meters in obstacle-free environments. Field tests were conducted during active harvest operations at a commercial potato farm, demonstrating the system’s robustness under real-world conditions. Additionally, a Grading Localization Synchronization System (GLSS) was implemented to predict tuber travel times during bin filling operations: thus, synchronizing localization with machine vision grading. The experiment was repeated for 30 trials, capturing both actual tuber travel times, and predicted times for nine combinations of bin-piler extension and conveyor belt speed. The system integrated real-time monitoring of bin-piler extension and belt speed, achieving synchronization RMSE values as low as 0.356 seconds with a Linear Regression model, compared to 0.585 seconds without. By creating a detailed 3D quality map of the storage facility, integrating tuber quality data with their spatial and temporal placement, and uploading this information to a remote server, the system enables centralized monitoring and analysis. This integrated approach significantly enhances traceability, reduces post-harvest losses, and improves the overall quality management of stored potato tubers.Item Open Access A Cost-Effectiveness Analysis of the Prostate Cancer Patient Empowerment Program(2024-12-18) Nuyens, Alexandra; No; Master of Science; Department of Community Health & Epidemiology; Received; n/a; No; Rob Rutledge; Mohammad Hajizadeh; Gabriela IlieProstate cancer is the most prevalent cancer among Canadian males, causing adverse effects and increasing healthcare costs. The Prostate Cancer Patient Empowerment Program (PC-PEP) is a home-based intervention aimed at reducing mental distress, improving physical/urinary functions, and enhancing quality of life. This study evaluated PC-PEP’s cost-effectiveness, hypothesizing that early implementation reduces healthcare spending and improves patient outcomes. In a six-month cross-over randomized trial, participants were assigned to PC-PEP or a waitlist control group. PC-PEP included daily stress reduction, fitness routines, pelvic floor exercises, healthy habits, intimacy training, social support and dietary recommendations. Results demonstrated PC-PEP’s cost-effectiveness. At six months, the intervention saved 411.53 CAD per patient and prevented 30% of psychological distress cases while gaining 0.0134 QALYs. At 12 months, savings increased to 660.89 CAD, preventing 31% of psychological distress cases and gaining 0.0344 QALYs. These findings support integrating PC-PEP into clinical practice to reduce costs and improve outcomes.Item Embargo ENHANCING GLIOBLASTOMA THERAPY: COMBINING DEEP LEARNING SEGMENTATION WITH ROBOTIC HISTOTRIPSY(2024-12-15) Dorosti, Shadi; Not Applicable; Master of Applied Science; School of Biomedical Engineering; Received; Frank Rudzicz; Yes; Rob Adamson; Jeremy Brown; Thomas LandryGlioblastoma multiforme (GBM) is the most aggressive and prevalent adult brain cancer, with a median survival of 14 months due to its rapid growth, invasiveness, and resistance to conventional treatments. Current challenges include incomplete surgical removal caused by GBM’s infiltrative nature and limitations in intraoperative visualization techniques, posing significant risks to surrounding healthy tissue. Minimally invasive technologies like histotripsy, which uses focused ultrasound for mechanical tumor ablation, offer promising alternatives but require precise tumor delineation and targeting. This research addresses these challenges by developing an AI-driven framework for automatic tumor segmentation and robotic control for accurate histotripsy delivery. Testing on ex vivo and in vivo models demonstrated minor under-treatment. Similarly, in mouse models injected with GL261 cells, a manageable over-treatment was observed, which can be adjusted due to the flexible design of the developed algorithm. Additionally, applying a deep learning model achieved high real-time tumor segmentation performance, significantly enhancing both accuracy and efficiency.Item Embargo Servants of God and Slaves of the Devil?: Witchcraft, Tyranny, and Skepticism on the Early Modern Stage(2024-12-12) Vogel Kubik, Sharon; Not Applicable; Doctor of Philosophy; Department of English; Not Applicable; Dr. Mary Floyd Wilson; Not Applicable; Dr. Goran Stanivukovic; Dr. Roberta Barker; Dr. Kathy Cawsey; Dr. Christina Luckyj; Dr. Andrew BrownWhen King James I ascended the English throne in 1603, his book Daemonologie, a treatise on witchcraft originally published in 1597, was reprinted in London, and James’s fascination for witchcraft was soon widely known. In 1606, Macbeth was performed, and that play that included witchcraft was soon to be followed by several other witchcraft plays. Some scholars have interpreted this Jacobean trend as a compliment to the king’s interests (Paul, Kearnan). However, although these plays draw on James’s demonological interests, they do not use the topic of witchcraft to flatter his authority. Rather, they use witch characters to expose corruption in royal courts and community leaders alike, representing tyranny and not witchcraft as the true threat to a nation. In early modern literature, the king and the witch are often represented as opposites. According to Newes from Scotland, “the King is the child & servant of God, and [the witches] but servants to the devil” (D3r). This binary often works to flatter the monarch; Ben Jonson’s Masque of Queens, for example, uses witches as a foil to royalty. However, I argue that the plays I discuss turn the blame on rulers and power structures, breaking down the established binary between the witch and the godly ruler, or the witch and the godly community. Dismantling the binary from both ends, these plays build on contemporary skepticism about witchcraft and witch trials to represent rulers as tyrants and communities as corrupt. Removing the opposition between witch and legitimate ruler, they portray the authorities as inept and ineffective (The Merry Wives of Windsor), illegitimate and tyrannical (Macbeth), morally bankrupt (The Witch), paranoid and vacillating (The Tempest), or corrupt (The Witch of Edmonton). By featuring only witches and corrupt leaders, without a just ruler to represent a clear binary opposite, these plays then contrast corrupt leadership with witchcraft to demonstrate that tyranny is the greater of the two evils. Using witchcraft to expose the corruption of both royal and community leadership, these plays critique power structures rather than legitimizing them.Item Open Access An Aristotelian analysis of war and conflict on social media(2024-12-13) Lee, Peter; Not Applicable; Master of Arts; Department of Philosophy; Not Applicable; n/a; Not Applicable; Letitia Meynell; Greg Scherkoske; Duncan MacIntoshThis project provides an Aristotelian framework, using the concepts of mimesis and catharsis, kalon and character, and perfect friendship, to draw out why social media has the potential to better represent war and conflict than more traditional media such as television, radio, newspapers, etc. Media and journalism studies research about western media coverage of the Global War on Terror along with philosophical analyses of issues in media demonstrate the issues that social media has the potential to address. The potential benefit of social media is that it now allows users to participate in shaping how war and conflict is represented on the platform. Now that audiences have the ability to participate in and influence the representation of war and conflict on social media it is crucial that they have the capacity to do so responsibly which the Aristotlian concepts provide the foundation for the pathway to achieving this potential.Item Embargo Localization of North Atlantic Right Whales Using a Deformable Sonobuoy Array(2024-12-17) Thebeau, Kamden; Not Applicable; Master of Science; Department of Oceanography; Not Applicable; na; Not Applicable; Sarah Fortune; Bruce Martin; David Barclay; Carolyn BinderNorth Atlantic right whales are critically endangered, with an estimated 356 (+7/−10) individuals remaining as of 2023. Current mitigation measures include fishing area closures and vessel speed slowdowns when a right whale is detected acoustically or visually. Although the primary means of detection is from aerial surveys, passive acoustic monitoring has the advantage of being long-term and can be persistent without requiring continual human observation. However, acoustic detections currently used in Canada do not include localization estimates, which could enable better management decisions. This thesis examines three localization algorithms: bearing localization, time-difference-of-arrival, and matched-field processing. They were evaluated according to the precision they provided with the location estimates and the assumptions needed to use them. Based on the results, the bearing and time-difference-of-arrival algorithms showed promise in improving mitigation procedures with their localization estimates. However, given its uncertainty and assumptions, matched-field processing was deemed untrustworthy.Item Open Access Proprioception After Upper Extremity Agonist Antagonist Myoneural Interface and Development of a Force Myography System for Prosthesis Control(2024-12-15) Gudimella, Rakesh; No; Master of Applied Science; School of Biomedical Engineering; Received; Janie Wilson; No; David Tang; Jeremy Brown; Robert Adamson; Ya-Jun PanPurpose: Agonist-antagonist myoneural interface (AMI) is a surgical procedure hypothesized to improve proprioception after amputation. We aimed to translate this procedure to transradial hand amputation and develop a quantitative assessment of proprioception in amputees for a pilot study. Methods: The transradial AMI technique was performed and described as a surgical case study. We developed a pilot experiment for quantitative assessment of proprioception in amputees based on surface force myography (sFMG) of remnant forearm muscle force using a custom designed force sensor optimized for sFMG. Results: The surgical procedure was technically successful with radiographic evidence of a functioning AMI with 15-21 mm of tendon excursion at 18-month follow up. The AMI amputee’s performance at a force-matching task was similar to non-amputees, whereas the standard amputee was an outlier with worse performance (p=0.015). Conclusion: The AMI technique is feasible and safe for transradial amputation. The pilot results suggest that a functioning AMI may improve force-matching accuracy.Item Open Access DIVERSITY SPILLOVER EFFECTS IN SUPPLY CHAINS(2024-12-12) Sadeghi Morad, Sanaz; Not Applicable; Master of Science; Business; Not Applicable; n/a; Not Applicable; Oumar Sy; Sadok El Ghoul; Najah AttigGender diversity is a top priority and trend subject that has gained increased attention recently. This thesis addresses two novel research questions. First, it investigates the extent of gender diversity diffusion within the supply chain by exploring the relationship between the workforce gender diversity of suppliers and that of their major customers. It then examines the extent to which the gap in workforce gender diversity has economic implications by addressing its impact on corporate value. Findings show a significant spillover effect, where customer firms with strong gender diversity policies positively influence diversity among their suppliers. This shows how important customer relationships are in helping diversity grow across companies.Item Open Access Halifax as an element of seapower, 1749-1766(1962) Douglas, William Alexander Binny; Not Applicable; Master of Arts; Department of History; Not Applicable; unknown; Not Applicable; unknown; C. Bruce FergussonNot until the last years of the War of Austrian Succession was the strategic significance of North America appreciated by the Administration under the Duke of Newcastle. In the Introduction to this thesis an attempt is made to show how the importance of Nova Scotia rose as the English turned to a maritime strategy in the war against the Bourbon Powers. 2. The founding of Halifax in 1749 was directly related to the increased importance of Nova Scotia in official eyes. The concept which was drawn up by the planners was ambitious and could not be realized because of deliberate interference by French interests -- Chapter One describes the change from a plan of peaceful colonization to one of military occupation. 3. Chapter Two analyses the part played by naval and provincial armed vessels from 1749 until the capture of Fort Beausejour in 1755. 4. Chapters Three and Four examine the part played by Halifax in supporting Naval Operations in North America during the Seven Years War. The first part of the North American War was defensive in nature, designed to contain the French. In 1757 the "Grand Enterprise" was set on foot, and much depended on the effective use of Halifax as a maritime base. Much of the success of Halifax in this role demanded upon the vigorous naval offensive prosecuted in the Eastern Atlantic by Boscawen and Hawks. 5. After the conquest of Canada Halifax was maintained as an important naval base. The dockyard was completed, and accurate surveys of the Nova Scotian coast were begun. In the first few years after the Peace of Paris in 1763 the existence of a dockyard port in North America permitted the logical use of sea power to protect British mercantile interests against smuggling. Chapter Five describes the measures taken at Halifax between 1760 and 1766, and examines the failures which were experiences in attempting to enforce the navigation laws and the Stamp Act. 6. In the Conclusions to this thesis an assessment of the contribution of seapower to the founding and survival of Halifax is made; and on the other hand an attempt is made to estimate the nature of Halifax's contribution to British sea power from 1749 to 1766.Item Embargo Enzymatic Hydrolysis of Cellulose and Proteins in Spent Coffee Grounds(2024-12-14) Cavanagh, Quinn; Not Applicable; Master of Applied Science; Department of Process Engineering and Applied Science; Not Applicable; N/A; Not Applicable; Dr. Vasantha Rupasinghe; Dr. Khaled Benis; Dr. Sophia He; Dr. Su-Ling Brooks; Dr. Vasantha RupasingheThis study investigated the enzymatic hydrolysis of polysaccharides and proteins in spent coffee grounds (SCG) to enhance bioavailability and digestibility for potential food additive applications. Using Viscozyme® L, a commercial lignocellulosic enzyme cocktail, the research explored how process modifications impact enzymatic efficiency. Two pre-treatments were examined: Alcalase® (a protease enzymatic pre-treatment) and particle size fractionation (a physical pre-treatment). Apparent Michaelis-Menten kinetics were employed to model enzymatic reaction kinetics in these insoluble systems. The effects of enzyme/substrate ratio on polysaccharide hydrolysis efficiency were systematically evaluated at the manufacturer's recommended pH and temperature. The study was conducted at 50°C, pH 4.8, with varying enzyme loadings and a reaction time of 24 hours. Results showed that particle size reduction through fractionation achieved the highest degree of hydrolysis (27.87%) and sugar yield at a Viscozyme® L loading of 0.01mL/g, highlighting its potential for industrial applications. Alcalase® pre-treatment demonstrated a moderate improvement in lignocellulose hydrolysis efficiency, likely due to increased accessibility of carbohydrates to enzymes following protein structure breakdown. Kinetic modeling revealed that smaller particle sizes resulted in higher reaction rates and lower apparent Km values, indicating improved enzyme-substrate interactions. The research demonstrates the potential of SCG as a valuable resource for the food industry, offering a pathway to valorize this abundant waste stream.Item Open Access ASSESSING EQUIPMENT AND TECHNOLOGIES FOR USE IN THE DEVELOPMENT OF DYKELAND IN ATLANTIC CANADA FOR SUSTAINABLE AGRICULTURAL PRODUCTION(2024-12-14) Bilodeau, Mathieu; Not Applicable; Doctor of Philosophy; Faculty of Agriculture; Not Applicable; Shabnam Jabari; Yes; Brandon Heung; Aitazaz Farooque; Travis Esau; Qamar ZamanDykelands in Atlantic Canada represent highly productive yet environmentally vulnerable agricultural landscapes, facing challenges from rising sea levels and climate change. This thesis investigates advanced technologies to enhance dykeland management and sustainability. The first study quantifies land use in Nova Scotia’s dykelands using crop inventories and property boundaries, revealing forage production as the dominant agricultural use. The second study applies a Mask R-CNN deep learning model on LiDAR-derived elevation data to map land-formed fields, achieving a mean Average Precision of 0.89. The third study integrates AI-generated field boundaries, crop data, and economic tools within GIS to evaluate profitability, highlighting significant variability across dyke systems. Finally, drone-based remote sensing over three years demonstrates the critical role of surface drainage maintenance in mitigating flood risks and optimizing crop productivity. The findings provide valuable insights for stakeholders aiming to optimize agricultural productivity while making informed decisions in the current context of rising sea levels.Item Open Access A CRITICAL REVIEW AND COMPARISON OF METHODS TO PREDICT MORTALITY IN PEOPLE WITH CYSTIC FIBROSIS(2024-12-17) Cheng, Zijin; Not Applicable; Master of Science; Department of Mathematics & Statistics - Statistics Division; Not Applicable; n/a; Not Applicable; Dr. Joanna Mills Flemming; Dr. Cindy Feng; Dr. Orla Murphy; Dr. Sanja StanojevicCystic fibrosis (CF) is a rare genetic disease that predominantly affects the lungs. Lung damage is the primary cause of complications and mortality in individuals with CF. Lung transplantation is one of the few treatment options available for those with end-stage lung damage. Due to the limited availability of donor lungs, selecting transplant candidates carefully is crucial to maximizing long-term survival. The timing of the transplant plays a vital role in survival; thus, accurately predicting individuals with an increased risk of mortality is essential for prioritizing candidates for transplantation. Several models have been proposed to predict the risk of mortality in CF patients. However, only one of these models is currently in clinical use. This thesis aims to (1) review previously proposed models and (2) compare these models using a single dataset. Nine models were developed in the Canadian Cystic Fibrosis Registry. Three regression models (logistic, Cox and landmark regression) and three variable selection methods (forward, backward, and lasso) were paired to each other so that there were 3 × 3 = 9 models. Logistic and Cox regression showed better performance than landmark, and forward and backward selection generally performed better than lasso. However, while these models performed well, one did not perform much better than the others. They also did not address the problem of rare events. Therefore, more investigations are still needed to address the limitations of the models.