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Nature, Material, Home: Exploring the Human-Nature Connection through Handmade Building Materials
Get PDFThis thesis challenges the distance humans have put between themselves and nature through an exploration in biogenic building materials and a degrowth approach to dwelling construction. The research conducted identifies the core causes of the historically constructed divide between society and nature and recommends changes to degrow it. A series of experiments conducted at multiple scales informed the feasibility of the real-world applications of the thesis. The exploration of biogenic construction materials brings the theory of degrowth forward using a hands-on approach. The thesis proposes an architecture that presents an alternative approach to material production and building construction to create a dwelling that positions construction and human habitation within nature
Physics Informed Learning-Based Frequency Regulation and Virtual Inertia Control for Renewable Energy Generators in Power Systems
Get PDFThe increasing penetration of inverter-interfacing renewable energy-based distributed generators in the electrical power grid can help meet increasing global electricity demand, reduce greenhouse gas emissions, and lower dependency on depleting fossil fuels. However, due to the intermittency and randomness of renewable energy sources such as solar PV and wind, power electronics converters are utilized to provide power conditioning and are now displacing the conventional synchronous generators in the electric power grids with the direct consequences of a reduction in the overall system inertia and lower frequency response capability of the interconnected systems. The absence of inertia support and adequate frequency response capacity may cause recurring frequency deviations, power quality problems, power loss, instability issues and eventual blackouts. This research demonstrates novel solutions to these challenges by implementing a deep reinforcement learning algorithm to achieve model-free control designs. Specifically, this research investigated the dynamic behavior of the electric power grid with integrated renewable energy generators and demonstrated a data-driven deep reinforcement learning framework with optimization-based virtual inertia and damping control for distributed inverter-based generators that guarantee frequency stability and enable the integrated renewable energy generators to participate in primary frequency regulation. Firstly, a twin delayed deep deterministic policy gradient (TD3) algorithm-based virtual inertia control for power grids with energy storage systems (ESSs) is proposed. Secondly, the inertia contribution and the effect of wind variability and fault ride-through capability of a grid-connected variable speed doubly fed induction generator (DFIG) wind turbine was studied. Thirdly, a learning-based predictive virtual inertia control is proposed for frequency regulation in low-inertia power grids. This approach utilized a physics-informed neural network (PINN) with a safety filter to improve model uncertainty and facilitate real-world application of deep reinforcement learning-based control systems for power grids with inverter-interfacing distributed generators
Daughters of the Diaspora: Nigerian Women Navigating Identity and Belonging in Canada
Get PDFThis thesis explores how first-generation millennial Nigerian women in Canada construct their identities and develop a sense of belonging. It focuses on continuous renegotiation, hybridity, and diaspora themes through an African feminist lens. It explores the challenges of maintaining ethnic cultural identity while navigating Canadian society, negotiating familial and societal expectations, and the role of community networks in fostering belonging. The findings reveal the transformative power of liminality as participants use the third space to navigate the complexities of the diasporic experience, where their identities are neither entirely Nigerian nor fully Canadian. This space enables them to reconcile competing cultural demands, resist patriarchal expectations, and actively choose which cultural practices to retain or transform. By centering their lived experiences, the thesis underscores the gendered and racialized dimensions of diasporic identity, highlighting how Nigerian women assert agency in shaping their identities amid challenges of exclusion and belonging
Gamespiration: A Tool to Help Game Designers find References for Game Ideas
Get PDFAn often overlooked aspect of video game research is the concept of game ideation. While toolkits exist that help brainstorm game ideas, they falter in helping designers visualize their ideas. A common way to visualize game ideas has been to use other video games as references, but due to the increasing quantity of video games, it is increasingly difficult to find suitable games. We created a prototype toolkit that aims to help game designers find relevant references for game ideas. The prototype represents games and game ideas as multidimensional vectors, and uses the vector space to identify games that are similar to each user-entered idea. Through user testing, we found that our prototype saves time and effort when compared to designers' usual ways of finding inspiration, and also provides an interesting design experience. Areas of potential improvement include increasing the fun and engagement that designers experience while using the software
Bangladeshi Migrants in Ottawa: A Socio-Spatial Analysis Through an Intersectional Approach
Get PDFThis thesis applies Koinova’s (2021) spatial linkages framework and Rodó-Zárate’s (2023) emotional geographic approach to explore how Bangladeshi migrants in Ottawa perceive their positionality in local and transnational landscapes. Organized under the themes of geographies of othering, geographies of togetherness, and familial ties, key findings address how migrants experience exclusion based on identity markers, which spaces enable cultural expression through practices like adda, and how family dynamics influence migrants' personal aspirations and cultural values while shaping their understanding of their socio-spatial positionality. These findings demonstrate the fluidity of migrants’ socio-spatial positionality, shifting across contexts and interactions. The study also reflects on the challenges of ethical considerations, participant recruitment, and the emotional toll of people-centered research. It recommends integrating mixed methods, exploring virtual spaces, and examining power dynamics within migrant communities. This research contributes to human geography by amplifying migrant voices and applying socio-spatial and intersectional concepts to lived experiences
Load Transfer and Creep Behaviour of Pile Foundations in Warming Permafrost
No full textThis study investigates the behaviour of steel pile–frozen soil interface with respect to varying temperatures, a critical issue as climate change degrades permafrost. Pullout pile load and creep tests were conducted on model steel pipe piles, instrumented with thermocouples and strain gauges. These tests revealed that warmer temperatures lead to weaker interface properties, ductile behaviour, and increased creep deformations. In comparison, colder temperatures enhance the pullout capacity, lead to brittle behaviour, and reduce the rate of creep. A critical temperature of -1°C was identified as a borderline between these two distinct behaviours. Temperature variations also create a volume change tendency which, in a confined environment, develops new stresses on the soil-pile interface, changing the confining pressures. Moreover, volume changes associated with the phase change of pore water to pore ice influence the stress conditions of the interface. These changes were recorded during thermal observations of the pile in the absence of mechanical loads. The findings showed that confining pressures are substantially large, highly temperature-dependent, and significantly influenced by water volume changes during phase transitions. Furthermore, pullout tests conducted at temperatures of -0.5°C and -1°C indicated that axial loading also affects the confining pressure profile. Laboratory experiments were numerically modelled using the FEM solver ABAQUS. A cohesive zone model combined with penalty-type contact interaction was used to simulate the pullout pile load tests, while a power law creep model was used to model the creep behaviour suspected in the tests. After verification of the model with the lab data, further analyses considered non-uniform temperature profiles and variable temperature time-series. The findings showed that variable temperature profiles, rather than average temperatures, should be considered in the design, as seasonal changes can significantly reduce pullout capacity and increase long-term creep deformations. The three stages of this study underscore the critical effect of temperature on the overall performance of pile foundations in frozen ground. It is of utmost importance to anticipate the collective long-term effects of seasonal temperature profiles experienced by the foundation during its service life
Evaluation of Surfactant-Enhanced Cleaning Solutions for Humic Acid and BSA Fouling on Ceramic Membranes
Get PDFChemically enhanced backwash (CEB) has achieved extensive application, offering substantial improvements in fouling mitigation and enhancing membrane performance and longevity. Two commercially available non-ionic surfactants, Tween 80 and Triton X100, were employed at their CMC and combined with conventional cleaning solutions to evaluate NOM fouling and cleaning at different concentrations, utilizing membrane permeability, resistance in series (RIS), carbon mass balance, and contact angle. The use of surfactants in CEB dropped the contact angle by 20%. The transmembrane pressure (TMP) with Tween 80 and Triton X-100 based CEB solutions were in the range of 83-100 kPa and 88-95 kPa with the medium concentrations (CEBMTw & CEBMTx) compared to DI which was 128 kPa for HA and BSA. Tween-based CEBs exhibited a 50% reduction in fouling resistance on HA and 90% on BSA when medium and high concentrations (CEBMTw and CEBHTw) were employed, in comparison to hydraulic (DI) backwash
Global Matrix 4.0 on physical activity for children and adolescents: project evolution, process evaluation, and future recommendations
No full textManuscript has been published online as Ahead of Print: Accepted author manuscript version reprinted, by permission, from Journal of Physical Activity and Health, [2025], https://doi.org/10.1123/jpah.2024-0513]. © Human Kinetics, Inc.Background: The Global Matrix initiative provides unique insights into child and adolescent
physical activity (PA) worldwide, yet requires substantial human efforts and financial support.
Purpose: This study aimed to evaluate the process and outcomes of the latest edition of the
initiative, the Global Matrix 4.0, reflect on its evolution from earlier editions, and provide
recommendations for future Global Matrices. Methods: The evaluation followed a pre-
determined plan, which included collecting and analyzing qualitative and quantitative data from
three online surveys to participants and online user activity metrics from MailChimp reports and
Google Analytics. Results: Global Matrix 4.0 participants (57 teams, 682 experts) assessed the
PA status in their country/jurisdiction on at least 10 PA indicators and submitted 570 grades for
global comparisons. Surveys were completed by 97-100% of targeted respondents and
demonstrated predominantly high satisfaction rates (>80%) with participation, outputs, and
project management. Lack of funding and inadequate national PA data availability were the
commonly reported concerns. Suggestions for improvement included amending indicators’
benchmarks and expanding the scope of the initiative to early years, underrepresented
populations, and additional indicators. Conclusions: This evaluation process revealed the
positive experience of Global Matrix 4.0 participants and the successful delivery of expected
outcomes. Reviewing the core set of indicators and benchmarks, expanding the initiative’s scope,
and fundraising efforts are recommended to further optimize the use of resources and maximize
impact
Assessing Historical Occupancy Trends in North American Flower Flies (Diptera: Syrphidae)
Get PDFGiven the declines occurring in many insect populations around the world, there is an urgent need to assess large-scale trends in important groups like pollinators. Museum data and biological collections present unique opportunities to assess population trends over long historical timescales. Here, I use a Bayesian multi-season, multi-species occupancy model to estimate long-term, range-wide occupancy changes for 318 North American syrphids, which are the most common pollinators of major crops after bees. Syrphids as a whole declined in occupancy by 10.5% between the periods of 1960–1990 and 1991–2020, but no overall trend was observed from an earlier baseline of 1900–1930. Species-specific declines outnumbered increases and were associated with smaller body size, predatory larvae, and the subfamily Syrphinae. I propose next steps to improve the reliability of this approach and address remaining knowledge gaps. Ultimately, these declines warrant further efforts to monitor and conserve syrphid populations