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AI-powered data-driven ground surface temperature forecasting for climate-resilient infrastructure in cold and permafrost regions
No full textClimate change poses significant challenges to infrastructure in cold regions, particularly in permafrost. Predicting ground surface temperature is essential for understanding the impacts of climate change and the planning, design, and management of climate-resilient infrastructure in these regions. However, existing methodologies face gaps and challenges, such as surface energy balance complexity, non-stationary correlations between climate variables, and the scarcity of historical ground temperature measurements in remote areas. This thesis develops artificial intelligence (AI) methodologies to predict ground surface temperature and assess its impacts on infrastructure in cold and permafrost regions.
An AI-powered methodology using machine learning models was developed to forecast long-term ground surface temperature from other climate variables. The predictions were used to assess the performance and sustainability of shallow geothermal systems in cold climates. A multi-variable evaluation of ERA5 and ERA5-Land datasets was then conducted in order to utilize reanalysis data for AI model training. The methodology was further advanced using long short-term memory (LSTM) networks and multiple predictor variables from ERA5-Land data, including air temperature, irradiance, wind speed, and snow depth. A framework was then developed to assess climate-driven permafrost thaw threat using ground surface temperature and ground ice distribution data. It was applied to assess threats to three major northern Canadian land transportation infrastructure, including the Hudson Bay Railway, the Mackenzie Northern Railway, and the Inuvik–Tuktoyaktuk Highway.
A comparative analysis of surface boundary condition methods for thermal geotechnical analysis was also conducted by evaluating the AI-powered approach, the n-factors, and the surface energy balance heat flux. The AI-based approach outperformed traditional methods. The feasibility of climate-driven geotechnical simulations using an AI-predicted surface boundary condition was demonstrated through a case study in Salluit, Nunavik. Finite element models indicated significant changes in the active layer thickness and inferred supra-permafrost talik under future climate scenarios, highlighting substantial risks to infrastructure due to climate change.Mitacs Accelerate Entrepreneur [Award Number IT20113]
Graduate Enhancement of Tri-Council Stipends (GETS)May 202
Impact of starch-hydrocolloid interaction on pasting properties and enzymatic hydrolysis
Get PDFHydrocolloids are extensively used for food processing because their techno functional properties (emulsifier, stabilizer, and structural agent). But there is increasing interest in their role connected with nutritional improvements, particularly related to starch hydrolysis rates, which might involve the viscosity resulting from starch-hydrocolloid interaction. The objective of this research was to investigate the impact of gels viscosity on the enzymatic hydrolysis of a range of starch gels made with different starches and hydrocolloids. Heterogeneous systems (starch-hydrocolloid) were prepared with several starches (corn, wheat, rice, potato, cassava, pea) and hydrocolloids (locust bean gum, guar gum, xanthan gum, hydroxypropylmethylcellulose K4M, psyllium) at different concentrations (0%–0.5% - 2.5%). The starch-hydrocolloid pasting behavior and their susceptibility to amylase hydrolysis was recorded with the Rapid Viscoanalyzer following a rapid method (Santamaria, Montes, Garzon, Moreira, & Rosell, 2022a). The viscosity decay due to alpha-amylase activity was modeled to obtain starch gels hydrolysis rate (k). A negative correlation was found among kinetic constant (k) and viscosity at 37 ◦C (r = − 0.55), setback (r = − 0.50), and area under the pasting curve (r = − 0.42). For instance, xanthan gum and psyllium addition showed strong negative correlation between kinetic constant and viscosity at 37 ◦C (r = − 0.75) and setback (r = − 0.79), respectively, particularly when blended with potato starch. These correlations indicate that pasting properties of the starch-hydrocolloid systems might be predictors of the enzymatic digestion rate of the gels, allowing the design of foods with controlled postprandial glucose response
Adult attitudes towards Dene Yati/Zhatié: a community questionnaire
Get PDFA comparison of language attitudes in adults from two Dene-speaking communities in Canada’s Northwest Territories describes attitudes which are broadly homogenous, with some variation dependent on demographics and beliefs regarding the language and language vitality. The results of the study show overall low attitudes among respondents in both communities, affected by the rating of the use of the language in workplaces and despite strongly positive attitudes in the affective dimension. Positive attitudes in an individual are associated with strength of Dene identity and proficiency in the language, with these conditions promoting one another. Concerns about language vitality are reflected in both communities’ focus on the importance of generational language transfer occurring in the home. The fact that the majority of survey respondents rate themselves as emergent speakers of the language may be indicative of low rates of language use, in turn contributing to concerns about vitality. However, the broad base of support for the language and language learning in the communities shows awareness of the situation and a keen understanding of the value of the language to cultural revitalization and its potential contribution to wellness amongst young learners.May 202
Experimental and numerical analysis of steel I-multigirder bridges under traffic loads
No full textThis thesis investigates two critical aspects of bridge engineering: the fatigue life of bridges under traffic loads and the impact of cold temperatures on their ultimate capacity for
composite I-girder bridges. The first part of the study examines the fatigue resistance of continuous steel I-girder bridges, analyzing the influence of girder profiles and stress
concentrations on fatigue damage. Monte Carlo simulations indicate that optimizing girder geometry can reduce the risk of fatigue damage by up to 35% over a 75-year service life.
The second part of the study explores the structural behavior of steel I-girder and reinforced concrete deck bridges under cold temperature conditions. Experimental testing using a
scaled bridge model subjected to four-point bending tests demonstrated a 10.3% increase in ultimate load resistance in cold conditions compared to tests conducted at normal
temperatures. However, this improvement came at the cost of a 44.5% reduction in maximum deflection and a 55.4% decline in ductility for the most deformation-sensitive
girder (G1). While cold temperature exposure resulted in a modest increase in strength, these findings provide valuable insights for designing bridges in cold climates.May 202
Hena kiksuya mayanipte ye! ‘Remembering’ for Indigenous data, research, and spectrum sovereignty
Get PDFThis research calls for epistemic justice where Treaty One, Oceti Sakowin, and the Red River Métis Nation can exercise rights over data, and research that is free from the constraints of settler colonial oversights and manipulation. This research stands alongside Indigenous research sovereignty scholars’ who provide the rationale for critiquing settler colonial infrastructures by placing rights-based frameworks at the forefront to advance the broader movement of Indigenous data sovereignty. I do this research through evaluation and analysis of settler-imposed policies in place-based context, referring to the University of Manitoba and administrations’ external influences, including the provincial and federal government. My thesis is rooted in the core methodologies of truth-telling, remembering, telling it straight, and takes a language revitalization approach to invoke collective memory and to assert Indigenous data, research, and spectrum sovereignty. I argue that language reflects place-based and nation specificities as dialects differ from nation to nation, place to place but also re-make relationality to data, law making, science, and technologies. Through the synchronized kinetic energy produced within this thesis, I identified a limitation of place-based and nation-specific infrastructures or collective collaboration, consent, and consensus with treaty and inherent rights holders of Treaty One, Oceti Sakowin, and the Red River Métis Nation at the University of Manitoba. By transmitting kinetic energy, this thesis contributes to the larger field of Critical Indigenous Studies through centering Anishinaabeg and Dakota Oyate ontologies, epistemologies, and methodologies to demonstrate nation-rebuilding practices of re-making relationality beyond and outside of colonial bounds that further Indigenous data, research, and spectrum sovereignty movements. My thesis is here to remind Indigenous Peoples to refuse the ongoing colonial harms, and colonial ideologies within data, and research ecosystems.May 202
Urban cycling-specific active transportation behaviour is sensitive to the fresh start effect: triangulating observational evidence from real world data
Get PDFAbstract Background This study determined if cycling-specific active transportation (AT) was sensitive to the behavioural economics heuristic “The Fresh Start Effect”, with the beginning of a work week being temporal landmark for cycling to work. Methods We triangulated data from five sources to test the study hypothesis. First, publicly available cycling traffic data collected from May to September between 2014 and 2019 using electromagnetic counters (EcoCounter Inc, Montreal Qc.) were used to categorize 5 urban trails as “AT” or “leisure” based on hourly cycling traffic patterns. Linear regression model with repeated measures, compared daily trends in cycling traffic over the course of a work week along the different trail types and then compared with daily trends in occupational bicycle parking (n = 56,307 counts), vehicular traffic (n = 6.2 M counts), and sales from a local coffee shop (n = 166,753 counts) over the same time frame. Effect sizes were compared to daily trends in fitness centre attendance (n = 563,290 counts), a positive control for the Fresh Start Effect. Results We found a significant ~ 22% decline in daily cycling traffic on both AT (-147 cyclists/day; 95% CI: -199.0 to -95 cyclists/day) and leisure trails (-22 cyclists/day; 95% CI: -59 to + 15 cyclists/day) over the course of a work week. The relative decline over the work week in AT-based cycling traffic was similar to the decline in daily parking (~ 14%; -12 cyclists/day; 95% CI: -17 to -7 cyclists/day). The relative effect size of this trend was nearly identical to the decline in fitness centre attendance over the work week (~ 21%; -592 visits/day; 95% CI: -759 visits/day to -425 visits/day), replicating the original Fresh Start Effect. In contrast to the decline in AT-based cycling traffic, daily vehicular traffic (+ 2248 cars/day; 95% CI: 2022 to + 3674 cars/day) and coffee sales (+ 31 units/day; 95% CI: +22 to + 42 units/day) increased ~ 7% from the beginning to the end of a work week. Conclusions The weekly patterns of AT-based cycling are sensitive to the Fresh Start Effect. This observation could be used to inform policies for increasing cycling rates in urban centres
Alternative organizing for advancing social and ecological sustainability
No full textTo address the shortcomings of the dominant form of organizing, alternative organizations offer alternative ways of organizing to promote practices that can enhance socio-ecological well-being. This dissertation includes three interrelated essays on a local alternative organization: Fireweed Food Co-op. The first essay explores the issue of degeneration (i.e., losing alternative values and practices over time) in alternative organizations and explores how Fireweed has been able to avoid two types of degeneration (i.e., exposure and insulation) common in alternative organizing endeavors. Three interrelated mechanisms (i.e., pure alt-visioning, accepting imperfection, and ongoing reflexivity) have enabled Fireweed to consciously synthesize mainstream and alternative practices without being degenerated. The second essay questions the common relationship building theories in organization studies (e.g., network-theory, social capital, and instrumental stakeholder theory) and shows how Fireweed’s efforts in building an organizational-level caring community can offer a better alternative relational theory for cooperatives that seek to create true social value. In the final essay, I draw on one of the findings in the first essay and explain how dynamic collective reflexivity can assist alternative organizations sustain their alternativeness over time.May 202
Indigenous genocide and the pandemic: the case of Brazil
Get PDFIn April 2024, Brazil initiated a historic process of reparations for state-led injustices against Indigenous peoples. This process revisits key historical episodes of Indigenous genocide to promote memory, truth, and accountability. Drawing on contemporary definitions of genocide, encompassing both hot and cold forms, this article examines the longstanding cold genocide perpetrated by the State, highlighting flare-up moments of hot genocide. While cold genocide unfolds gradually through systemic neglect and structural violence, hot genocide manifests in direct, overt acts of mass killing and persecution. This study focuses primarily on the recent pandemic, during which the government exploited the health crisis to intensify the ongoing extermination of Indigenous populations. The analysis is grounded in a historical perspective and a detailed examination of the Pandemic Parliamentary Commission of Inquiry Final Report.May 202
Inverter-based resources controlled as a virtual synchronous machine for improved system dynamic performance and stability
Get PDFThe large-scale penetration of Renewable Energy Resources (RES) will displace conventional synchronous machine-based power generation, reducing the overall system inertia and resulting in lower Short Circuit Levels (SCLs) at the locations where RES connect to the grid. RES, such as wind and solar PV, are interfaced with the power system through power electronic inverters. Operating inverter-based equipment under low inertia and SCLs presents several challenges, including poor fault recovery response, unstable oscillatory interactions, and the impact on torsional oscillations of thermal generating units. This research investigates the effectiveness of inverters controlled as Virtual Synchronous Machines (VSMs) in addressing some of these issues.
In this research a Battery Energy Storage System (BESS) inverter is controlled as a VSM, with input signals derived from solving the time-domain equations of a synchronous machine. The responses of the exciter, governor, and power system stabilizer are also incorporated into the VSM control strategy. The dynamic characteristics of the proposed VSM are validated using a Single Machine Infinite Bus (SMIB) test model. The effectiveness of the VSM approach in mitigating specific technical challenges is verified through dynamic response studies conducted on several test systems, including a representative European transmission system. The VSM's response is compared to that of a conventional synchronous machine in all test cases, demonstrating a close correlation in dynamic behaviour. Additionally, the proposed VSM concept was implemented on a solar PV plant inverter operating in grid-following mode. The simulation results highlighted a hybrid method that combines the technical advantages of both typical grid-following and VSM-based inverter control designs. In all test scenarios, the simulation results confirm that the VSM performs as expected and can effectively mitigate stability issues related to low system inertia and low short circuit strength. Furthermore, this research explores the adaptability of VSM controls in providing essential functionalities, such as inertial and fast frequency response, to enhance grid stability, improve operational efficiency, and ensure compliance with grid code requirements.October 202
Unraveling the Peri-Implant Barrier
Get PDFThe long-term success of dental implants relies on the formation of a protective soft tissue barrier that limits pathogen infiltration into peri-implant tissues. However, our understanding of how this barrier develops under different implant placement protocols (i.e., immediate vs. delayed placement) and in response to varying implant surface characteristics remains limited.
This study systematically evaluates the formation and maturation of peri-implant soft tissues in two contexts: (1) immediate versus delayed implant placement and (2) anodized versus machined implant surfaces.
Part I: Miniaturized titanium implants were placed in either fresh extraction sockets or healed maxillary first molar sites in mice. Peri-implant soft tissues were assessed at multiple time points to investigate molecular attachment mechanisms and the barrier function of the soft tissue. A healthy junctional epithelium served as a positive control. Notably, no significant differences were observed in the rate of soft tissue integration between immediate and delayed implants. However, mucosal integration took at least twice as long as osseointegration in this model.
Part II: Scanning electron microscopy and surface chemistry characterization were performed on miniaturized anodized and machined implants. Following placement in fresh extraction sockets, peri-implant tissues were examined at four time points. The findings corroborated those from Part I and led to several key conclusions:
1. Maturation of the peri-implant epithelium (PIE) is a prolonged process, aligning with
clinical observations.
2. Soft tissue integration occurs more slowly than bone integration.
3. Anodized implant surfaces offer a transient advantage in promoting soft tissue maturation.
Together, these findings highlight the extended timeline required for PIE maturation, underscoring the potential clinical benefits of strategies aimed at accelerating this process.Research Manitoba Master’s Studentship Award 2023
University of Manitob