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    The Effect of Steam Explosion on Lipids Extraction From Microalgae and Derivation of Pectin Films from Waste Culture

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    The objective of this study was to investigate the properties of sustainable replacements for plastics and diesel fuel, derived from microalgae (Chlorella vulgaris) subjected to steam explosion. During the process, oven temperatures of up to 500 °C were reached, with the experiments left for different times after reaching their maximum internal temperature. Lipids were extracted from algal cultures using a modified Folch method. The waste microalgae were combined with pectin and glycerol to form biodegradable films, and their solubilities and tensile strengths were measured. The highest yield was 124 mg lipids/g microalgae from 400 °C steam explosion for 45 minutes after reaching maximum conditions. The highest tensile strength of the pectin films was 10.8 MPa, from 400 °C steam exploded microalgae. Overall, steam explosion can improve lipid accessibility and tensile properties of pectin films, and a major recommendation was to perform a life cycle analysis on the entire process to determine energy balances and its impact on the environment

    Design of Active Pharmaceutical Ingredients Solid States in Crystallization Processes

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    Crystallization is an important technique to obtain solid-state drugs from solutions. Physicochemical properties of the active pharmaceutical ingredients (APIs) are determined by crystallization. More than half of the active pharmaceutical ingredients exhibit polymorphism, the phenomenon of chemical species showing more than one unit-cell structure in the solid state. Controlling polymorphism is one of the most important goals during pharmaceutical manufacturing. Nevertheless, the control of polymorphism is sometimes not enough to realize the targeted physicochemical properties. Suitable additives (coformers/salt formers) are explored to generate new multi-component solid phases of poorly soluble/bioavailable active pharmaceutical ingredients (APIs). The design of pharmaceutical cocrystals and salts has thus become significantly important in recent years. With the introduction of suitable coformers or salt formers, the targeted physicochemical property can be well improved. This work aims to provide insights into the design, characterization, optimization and control of API solid states in crystallization processes. The characterization of crystal packing structures, melting points, and tuned solubilities is carried out for all cases studied in the thesis. First, the solvent screening for an API, which is the basis of solution crystallization, is researched based on the solubility prediction using Hansen solubility parameters. Next, the optimal working conditions for harvesting the desired polymorph in continuous crystallization are investigated both experimentally and numerically. Numerical models of single-stage and two-stage mixed-suspension mixed-product removal (MSMPR) crystallizers are developed to test different working environments. The production of kinetically unfavorable polymorph of L-glutamic acid is realized by experiment. Subsequently, for APIs of low solubility (biopharmaceutics classification system (BCS) class II or IV), a screening method using hydrogen-bond propensity and hydrogen-bond coordination calculations is developed to improve the drug solubility and dissolution. Lastly, regardless of single-component or multicomponent API solid phases, poor morphology such as needle-like or plate-like would impede the downstream processes. A new spherical crystallization method depending on the liquid-liquid phase separation is developed with the help of an in-situ Pixact Crystallization Monitoring (PCM) system. Spherical crystals are successfully produced to avoid the original plate-like morphology of vanillin crystals

    The Impact of Simulated Image Acquisition Time Reduction on Image Quality and Parameters of Myocardial Perfusion Imaging Using a Dedicated Cardiac Camera

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    Heart disease is the second leading cause of death in Canada, highlighting the crucial role of early diagnosis in disease management. Myocardial perfusion imaging (MPI), is widely employed for this purpose, involves injecting a radiopharmaceutical into the body, imaging its distribution with a gamma camera, and revealing cardiac blood flow patterns. A significant challenge in MPI is the lengthy 8 to 10 minutes required for stress and rest imaging, potentially causing patient discomfort and compromising image quality due to movement. In a clinical study with 26 patients, post-processed data manipulation simulated a reduction in MPI imaging time. The findings indicated that MPI imaging time can be effectively shortened to 4 and 5 minutes for stress and rest imaging, respectively, maintaining clinical interpretation quality in our cohort. This promising outcome prompts further exploration of timely, comfortable MPI imaging feasibility for managing ischemic heart disease in a broader and diverse patient population

    Paradise Lost Book 4 - John Leonard Reading

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    Gust effect factors of components and cladding wind loads for low-slope roofs on low-rise buildings

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    Accurately predicting the wind loads on components and claddings (C&C) on roofs are important to enhance the resilience of buildings. Wind loads on structures can be estimated by mainly two methods in the prevalent building codes. The first method is to provide peak pressure coefficients which have been utilized by several design codes to provide wind loads for C&C, such as ASCE 7-22 and NBCC 2020. The second approach relies on the gust effect factor. This method has been widely adopted for evaluating wind loads for along-wind response of high-rise structures by considering both background response due to upstream turbulence and resonance response due to structural dynamics. However, NBCC 2020 also recommends adopting a gust effect factor of 2.5 for C&C of buildings greater than 20 m referenced to mean wind speed. In addition, EN1991-1-4 suggests using a constant structural factor ( ) – analogous to the gust effect factor - of 1.0 for roof elements and claddings. The present study examines the gust effect factors for local zones of low-sloped roofs of low-rise buildings, by employing the wind tunnel data from NIST database. The statistical parameters of wind pressures, such as mean, standard deviation, kurtosis, skewness and peak factor are particularly examined to demonstrate the statistical characteristics of wind pressures on local zones of roofs. This study concludes that the measured gust effect factors particularly for small effective wind areas, significantly exceed the prescribed values of 0.85 for main wind force resisting system in ASCE 7-22, surpass the provisions in NBCC for C&C of buildings exceeding 20 m, and exceed the value of 1.0 for C&C of low-rise buildings in EN1991-1-4. This discrepancy is attributed to the negligible effects of body-generated turbulence in building codes, such as separation bubble and conical vortices. Additionally, the highly non-Gaussian nature of wind pressures is observed for small effective wind area due to the body-generated turbulence. These findings suggest that when employing the gust effect factor method to predict wind loads for C&C, it is important to take the body-generated turbulence into account

    Pain Among Immigrants to Canada: Testing the Healthy Immigrant Effect

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    In Canada, immigrants compose roughly one quarter of the population. The health of immigrants and their descendants is key to understanding the future health profile of all Canadians. Current literature on the health of immigrants often uses self-rated health and has produced mixed results regarding the healthy immigrant effect (HIE). Using data from the 2022 NEST survey, my study tests the HIE using chronic pain as a measure of population health to investigate the differences in pain experience among immigrants compared to the Canadian-born population. My results support the HIE: immigrants are 28% less likely to experience pain than Canadian-born individuals. When accounting for immigrants’ recency of arrival, recent immigrants are slightly less likely to experience pain than established immigrants compared with Canadian-born individuals, aligning with the health deterioration effect. These findings support the HIE using pain as a different measure of health in a Canadian context

    Structural Optimization and Aerodynamic Behavior of Double-Curvature Cable Domes

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    Cable domes have been widely used in many architectural applications such as arenas, stadia, and religious facilities because of their light weight, attractive appearance, and adaptable forms. Yet, cable domes are very flexible and sensitive to wind loading. The main problem in traditional forms of cable domes with positive-Gaussian curvature is the potential instability under excessive loading due to slacking in cables and/or buckling in struts. This motived designers to develop new forms of cable domes with more stability and rigidity. The current study considers a new form of cable domes with double curvature (saddle-shaped dome) that is intended to have better stability and rigidity. However, its feasibility and stability need to be addressed before using it in practical applications. Moreover, accurate evaluation of wind pressure distribution on the roof is essential for understanding their aeroelastic behavior. A novel form-finding algorithm is introduced in this study utilizing NURBS curves to control the saddle surface curvature while searching for a feasible geometry and prestress distribution that gives the domes its stiffness before applying loads. A time-efficient optimization technique is then developed to optimize prestress level and cross sections to the minimum weight. The developed algorithms are employed to develop a large database of feasible and optimized domes considering different geometrical parameters. The database is employed to train surrogate functions that can be used by designers as a decision supporting tool in the preliminary design of double-curvature cable domes. The new form stability and rigidity under excessive loading is also investigated and compared with the traditional form with positive curvature. Finally, the wind-induced mean and peak pressure on double-curvature roofs are also reproduced using computational fluid dynamics simulations validated with wind-tunnel experiment considering a wide range of geometrical parameters. The adequacy of wind load provisions of Italian code for this new form with double curvature is also explored. The results demonstrated the capabilities of proposed algorithms in designing a feasible, more stable, and cost-minimized cable dome. The findings of this research are recommended to be considered when designing double curvature cable domes according to the current wind load provisions

    Towards Smart-Building Digital Twin: Data Integration, and Probabilistic Frameworks for Reliable Virtual Sensing, and Continuous Model Calibration

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    Buildings responsible for around 40% of global energy use and a third of emissions are increasingly scrutinized for their potential to lower energy consumption and emissions. Consequently, adopting advanced technologies such as IoT and AI in the building sector becomes crucial for more efficient and sustainable operations. Despite ongoing efforts, the rising trend emphasizes the need for more advanced, holistic technologies. In light of this need, smart-building digital twins have emerged, marking a significant shift toward building digitization. Smart-building digital twins employ data, information, and models to mirror static and dynamic aspects of buildings virtually. This approach establishes a bidirectional connection between physical buildings and their digital counterparts, enhancing performance with real-time monitoring, autonomous control, and visualization. While gaining momentum, adopting smart-building digital twins faces several challenges, such as achieving data interoperability, overcoming limited sensing environments, and continuously calibrating physics-based models with real-time sensor measurements. Therefore, this thesis tackles these three significant challenges to advance research in smart-building digital twins. Data interoperability challenges in smart buildings stem from heterogeneous, siloed data sources, impeding unified access for smart-building digital twin applications. This research presents a novel multi-layer architecture and method for integrating BIM and IoT data using domain ontologies, achieving unified access and semantic interoperability. Evaluations using actual building data demonstrated the effectiveness of these approaches in providing a robust data backbone for digital twin applications. Sensing limitations in buildings arise from the absence or malfunction of sensors and the difficulty of measuring certain variables. This thesis presents a novel probabilistic virtual sensor framework to estimate unobservable variables using existing sensor data while offering confidence measures in these estimates. Evaluation with simulated building data proved these models\u27 accuracy, efficiency, and reliability in addressing building sensing limitations. The challenge in continuously calibrating physics-based models is the unobservability of influential model inputs. This thesis introduces a novel framework and calibrator model for continuously calibrating physics-based models while quantifying uncertainty and enabling multi-variable calibration under missing or noisy sensor data. The evaluation results confirmed that the proposed calibrator model accurately synchronized the outputs of physics-based models, meeting standard error thresholds for calibration accuracy

    SoHo Story

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    Formed by the London Community Foundation (LCF), the Vision SoHo Alliance is a partnership between six non-profit housing developers, which includes Chelsea Green Home Society, Homes Unlimited, Indwell, Residenza Affordable Housing, London Affordable Housing Foundation, and Zerin Development Corporation. Vision SoHo Alliance will create 650-unit apartments, of which 30-60% will be affordable units, in seven buildings on the former South Street Victoria Hospital property. Most buildings will be located on the block bounded by Waterloo, South, Colborne, and Hill streets. Another building will be constructed at the northeast corner of South and Colborne. Indwell purchased the former Faculty of Medicine building and War Memorial Children’s Hospital to be redeveloped as housing and designated as heritage buildings under the Ontario Heritage Act. The Vision SoHo Alliance tasked Western’s MA Public History Program with researching and compiling stories of St. David’s Ward, now known as the South of Horton, or SoHo neighbourhood (bounded by the Canadian National Railway and Adelaide Street with the Thames River acting as a natural south-west barrier), the former Western Faculty of Medicine building (1921), and the War Memorial Children’s Hospital (1922). This research included orally interviewing Londoners who had or have ties to the SoHo area. This is in effort to preserve the history of one of the oldest and most culturally diverse area in London, and which changed demographically following the medical school moving to Western’s main campus in 1965, the closing of War Memorial in 1985, and of Victoria Hospital in 2013. Western’s MA Public History Program plans to use the compiled research and recordings to curate a digitally interactive outdoor exhibit installed in the green spaces of the Alliance’s property, which will highlight the significance of the neighbourhood and the area’s medical history. The goals of this report are to: • Document the history of the SoHo area, including Indigenous presence, immigration, and neighbourhood culture; • Create a thematic historical overview of the neighbourhood, the medical school, and War Memorial Children’s Hospital; • Compile associated stories, memories, and photographs provided by the public. This is the final two-year research report which revises and extend the first-year report called Echoes of SoHo

    Cholinergic Modulation of Parvalbumin Neurons in Attention

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    The lack of treatments targeting the cognitive symptoms of schizophrenia has prompted interest in understanding the neural mechanisms of attention in the context of the disease. Acetylcholine (ACh) and parvalbumin-expressing interneurons (PVIs) are pivotal in controlling top-down attention in the prefrontal cortex, with their dysfunction linked to schizophrenia. Despite evidence hinting at ACh\u27s interaction with PVIs during attention, no prior studies have explored this interaction and its role in attention. This thesis employed pharmacological inhibition of muscarinic and nicotinic ACh receptors, alongside in vivo calcium recordings from prefrontal PVIs in mice engaged in an attention-based task. Muscarinic inhibition impaired behavior and PVI activity. M1-muscarinic receptor inhibition had no effect, while prefrontal nicotinic inhibition did not alter behavior or PVI activity. This indicates that prefrontal muscarinic signalling modulates PVI activity and plays a significant role in attention, while prefrontal nicotinic signalling lacks impact on prefrontal PVIs or a substantial role in attention


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