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Microgrid Formation-based Service Restoration Using Deep Reinforcement Learning and Optimal Switch Placement in Distribution Networks
Get PDFA power distribution network that demonstrates resilience has the ability to minimize the duration and severity of power outages, ensure uninterrupted service delivery, and enhance overall reliability. Resilience in this context refers to the network's capacity to withstand and quickly recover from disruptive events, such as equipment failures, natural disasters, or cyber attacks. By effectively mitigating the effects of such incidents, a resilient power distribution network can contribute to enhanced operational performance, customer satisfaction, and economic productivity. The implementation of microgrids as a response to power outages constitutes a viable approach for enhancing the resilience of the system.
In this work, a novel method for service restoration based on dynamic microgrid formation and deep reinforcement learning is proposed. To this end, microgrid formation-based service restoration is formulated as a Markov decision process. Then, by utilizing the node cell and route model concept, every distributed generation unit equipped with the black-start capability traverses the power system, thereby restoring power to the lines and nodes it visits. The deep Q-network is employed as a means to achieve optimal policy control, which guides agents in the selection of node cells that result in maximum load pick-up while adhering to operational constraints.
In the next step, a solution has been proposed for the switch placement problem in distribution networks, which results in a substantial improvement in service restoration. Accordingly, an effective algorithm, utilizing binary particle swarm optimization, is employed to optimize the placement of switches in distribution networks. The input data necessary for the proposed algorithm comprises information related to the power system topology and load point data. The fitness of the solution is assessed by minimizing the unsupplied loads and the number of switches placed in distribution networks.
The proposed methods are validated using a large-scale unbalanced distribution system consisting of 404 nodes, which is operated by Saskatoon Light and Power, a local utility in Saskatoon, Canada. Additionally, a balanced IEEE 33-node test system is also utilized for validation purposes
Hydrogeochemical Evolution of Groundwaters in the Williston Basin, Canada
Get PDFGlacial cycles over the last two million years have successfully altered deep groundwater flow in the Williston Basin, Canada. Mixing with evaporated paleoseawater has resulted in unique geochemical signatures in formation waters with spatial and temporal trends, however the timing of glaciogenic recharge into the Williston Basin and spatial understanding of the flow system is loosely constrained. I examine timing and effect of glaciogenic recharge by using an integration of fluid chemistry, stable isotope data, and transport modeling. Results demonstrate that meltwater arrived at depths of ~600 to 1000 m in the northcentral region of the Williston Basin at two separate time periods, 75 to 150 ka and 300 ka. Spatial analysis of geochemical data illustrates that meltwater recharge extended to a continuous recharge belt along the northern margin of the Williston Basin, greater than previously anticipated. Individual and multi-variate analysis of isotope and solute geochemistry exhibit trends that contribute to fractionation of δ18O, δ2H, 87Sr/86Sr, δ37Cl, and δ81Br, and validates the importance of water origin and variation in mineral composition on solute concentrations and isotope values. Although overprinting and mixing interactions may present challenges in geochemical interpretation, the inter-disciplinary approach used in this research contributes to a greater understanding of how glacial meltwater recharge altered geochemical landscapes during large-scale salt dissolution in the Williston Basin
Foxes and Lynx as Sentinels for Toxoplasma gondii across the Canadian North
Get PDFToxoplasma gondii is one of the most successful parasites in the world and can have serious adverse effects on immunocompromised individuals and foetuses. It is thus a parasite of public health concern, especially in the Canadian North where seroprevalence in some Inuit communities is much higher than in other parts of North America. Food-borne transmission is likely a significant route of transmission among northern residents as well as Arctic carnivores, where transmission may be altered by the rapid demographic and environmental changes affecting Arctic and subarctic regions. I focused on lynx as the only definitive host that can produce oocysts in subarctic regions, and foxes as intermediate hosts at high risk of exposure. The aim of this research was first to assess T. gondii exposure, prevalence and genetic diversity in foxes and lynx in northern Canada. I hypothesized that foxes would act as good sentinel species for T. gondii in the North since they occupy a high trophic position in the Arctic and are widespread in northern Canada. I also sought to determine if lynx are serving as definitive hosts for T. gondii using DNA based methods (real time PCR with melting-curve analysis) which are more sensitive than efforts to detect oocysts in feces. I used a sequence specific magnetic capture DNA extraction and real-time PCR to test whole hearts and brains of foxes and lynx. I tested samples serologically by enzyme-linked immunosorbent assay (ELISA) using fluids from thawed hearts. I targeted foxes from all four Inuit regions of Canada: Inuvialuit Settlement Region in Canada’s Western Arctic, Nunavut, Nunavik in northern Québec, and Nunatsiavut in Labrador. Exposure and tissue infection were lower in fox and lynx in Canada’s Western Arctic, and higher in the Eastern Arctic, especially the Hudson Bay region of Nunavik. These results are compatible with recent serological findings in people from Inuit Health Surveys, supporting the hypothesis that fox are indeed suitable sentinels of environmental transmission and human exposure to T. gondii. DNA consistent with that of T. gondii was detected in feces of one lynx from boreal regions of Québec, but was detected far more commonly in lynx tissues. While lynx are a potential source of oocysts, they may also contribute to transmission of this parasite through consumption of their tissues by other carnivores and harvesters. This supports my hypothesis that fox are primarily exposed to T. gondii through carnivory rather than consumption of oocysts produced locally by lynx. In order to determine the role prey species play in T. gondii prevalence, I used stable isotopes on muscle and hair of Nunavik foxes to reconstitute their diet and link diet with their infection status. I concluded that marine food sources and migratory birds are likely a major source of exposure in foxes to T. gondii in Nunavik, again similar to recent findings on consumption trends in people in Nunavik. This work reveals a better understanding of the distribution and introduction of T. gondii in fragile Arctic ecosystems. Ultimately, these findings inform future risk assessments to determine the potential human and animal health risks associated with T. gondii in northern ecosystems
“…taken in hand by Indians”: Jewish-Indigenous Relations in the Early Twentieth-Century Qu'Appelle Valley Region
No full textThe abstract of this item is unavailable due to an embargo
Biofortification of Plant-Based Food Products and Applications to the Athlete
No full textIntroduction: A diet relying more heavily on plant-based food products and less on animal-based products has been promoted to feed a growing world population in a sustainable fashion. One concern with such a dietary pattern is iron bioavailability, as plant-based sources of iron contain phytic acid, a compound that binds to cations such as iron, limiting absorption.
Objectives: The objectives of this research are to examine the efficacy of a biofortified pea protein (bred to have low phytic acid, and therefore high iron bioavailability) on nutritional intake and iron status in vulnerable athlete populations.
Methods: In study one, a pilot trial evaluated the acceptability of an experimental high-protein supplement (made from field peas with high iron bioavailability) and the feasibility of data collection measures in a group of female runners. Before and after an 8-week supplementation protocol, participants were assessed for iron status, body composition, and exercise performance. Participants were randomized to consume either a protein concentrate derived from regular peas, a protein concentrate derived from low phytic acid peas, or an isocaloric control (i.e., maltodextrin). Participants also consumed 500 mg of vitamin C daily throughout the trial to enhance iron absorption. The incidence of adverse effects thought to be related to the supplement (eg. Bloating, constipation, cramping) were assessed at weeks two, four, six, and eight. With feasibility confirmed, in study two, 28 female runners underwent the same measures as outlined in study one (iron status, body composition, and exercise performance) before and after being randomly assigned to consume either maltodextrin, regular pea protein, or low phytic acid pea protein along with 375 mg of vitamin C for eight weeks. In study three, the habitual dietary intake of macronutrients and key micronutrients (including iron) of 31 elite para cyclists was determined using a food frequency questionnaire. Risk of inadequacy was assessed using the estimated average requirement cut-point method and intakes were compared to daily recommended intake values. Lastly, in study four, four individuals with spinal cord injuries that were recreationally active were assessed for bowel function, iron status, body composition, and exercise performance before and after an 8-week intervention in which they supplemented with 40 g of low phytic acid pea concentrate and 125 mg vitamin C twice daily.
Results: In study one a high degree of compliance was observed for all supplements (maltodextrin= 99.2 ±0.9% compliant; regular pea= 96.3 ±2.1% compliant; low phytic acid= 97.8 ±2.3% compliant). No differences in the incidence of adverse effects between the maltodextrin and pea groups were evident (p=0.53,) nor were any symptoms severe enough to cause the individual to withdraw from the study. Study two found a modest, though statistically non-significant, increase in ferritin was observed for the two pea groups (regular pea= 14.4% increase from baseline; low phytic acid= 5.1% increase from baseline), compared to the maltodextrin group who had a decrease in ferritin (2.2%). Protein (p=0.03) and iron (p=0.01) intakes were significantly higher in the regular pea group compared to the maltodextrin group. No other differences in dietary intake were observed (p>0.05). In study three, athletes consumed most nutrients in excess of the daily recommended intakes with the exception of iodine (males=87% recommended dietary allowance; females=62% recommended dietary allowance) and fibre for men (84% adequate intake). The predicted risk of inadequacy was noted for iodine (89% and 83% risk of inadequacy for females and males, respectively) and vitamin D (84% and 83% risk of inadequacy for females and males, respectively). In study four, no differences were apparent in exercise performance or markers of iron (ferritin and hemoglobin); however, iron intakes increased from baseline to week six (p=0.047) and protein intakes trended toward increased from baseline to week eight (p=0.07). Scores of bowel dysfunction were largely unaltered in three participants, but one individual had a marked improvement.
Conclusion: Biofortified peas are well tolerated in both female runners and individuals with spinal cord injuries. Consumption of biofortified peas did not have any negative effects on nutrient intake, iron status, or exercise performance in these populations of active individuals. Thus, they have the potential to improve nutrient quality and health measures in vulnerable athlete populations. Larger doses or longer trials may be required to induce meaningful changes to iron status
FIRST PRINCIPLES STUDIES ON STRUCTURE-CARCINOGENICITY RELATION
No full textThe question behind all works presented in this thesis is “why do similarly structured molecules exhibit distinct carcinogenic behaviors?” Answering this question is important to not only the fields of Pharmacology and Toxicology but also the development of drug design and testing. Our goal is to explain such a macroscopic phenomenon with atomic-level physico-chemical properties and ultimately develop a theoretical model which is capable of describing the corresponding structure-carcinogenicity relationships. General metabolism pathways, specific mechanisms of bio-chemical transformation as well as relevant background knowledge for ligand-protein interaction are introduced in the first chapter. Three theoretical tools are employed for probing the critical changes due to subtle deviations of molecular structures. Specifically, Density Functional Theory (DFT) for calculating the electron density distribution and related electric properties such as dipole moments and localized electrophilicity. Meanwhile, Molecular Dynamic (MD) simulations and Bio-molecular Docking are applied for investigating and visualizing molecular interactions which emphasize more on the influence of steric effects. Theoretical studies on the ligand-protein binding orientation, probability and equilibrium binding positions were carried out and presented in Chapter 3, 4 and 5, respectively
A Test of the Cosmological Principle with Reported Superlarge Structures
Get PDFThe objective of this thesis is to investigate and study cross-correlation of large-scale structures as a test of the Cosmological Principle (CP). This begins with an explanation of the importance of CP to cosmology and astronomy, followed by a review of the concept of length scales as it pertains to CP, and a review of quasars and Gamma-ray Bursts (GRBs). The statistical methods and measurements used in this research will be explained in detail. The resulting statistics are explored for a Gamma-ray burst data set, two quasar data sets with positive and negative galactic latitude, and a data set comprised of quasar-GRB pairs to test for correlations. Statistically significant anomalies appearing in either method are discussed in detail, as well as specific analysis of signals that may relate to the previously reported structures. None of the signals discovered would indicate unusually large structures at a statistically significant level. The correlation study is likewise lacking in statistically significant signals, suggesting no apparent correlation between the GRB and quasar distributions. Lack of statistically significant structures in these distributions suggests that the Cosmological Principle holds. Sources of error are discussed. Potential future studies are laid out, including suggestions on how to increase the number of GRBs with redshift data
Characteristics and Origin of Rare Earth Mineralization at the Alces Lake Property, Northern Saskatchewan
Get PDFRare earth elements (REEs) are critical metals that are essential to the low-carbon economy, especially the rapidly-growing green energy production and storage industry. REEs have been produced from a great variety of deposit types related to magmatic, metamorphic, hydrothermal, chemical weathering, and sedimentary processes. Massive monazite mineralization at the Alces Lake REE property in the Beaverlodge Domain of the Rae Province of northern Saskatchewan has attracted recent exploration and has been suggested to represent a paleo-placer type deposit, which would imply significant resources; however, this interpretation for the origin of the REE mineralization is questionable.
The massive monazite mineralization at the Alces Lake property is situated on the eastern limb of a fault truncated synform fold. This synform fold is likely related to the nearby St. Louis Fault adjacent to an unconformity with Archean aged or Arrowsmith Orogeny-related gneisses and granites on the western limb and younger Paleoproterozoic gneisses and granites alongside the Murmac Bay Group metasedimentary rocks, metavolcanics, and quartzite on the eastern limb (Normand, 2014). The REE showings occur as monazite-biotite-mineralized pegmatites, massive biotite pegmatites, granitic pegmatites, allanite-rich veinlets, and large leucogranite bodies scattered throughout the property.
The REE mineralization at the Alces Lake property is primarily in the form of monazite, zircon, and allanite. The elevated REE contents largely correspond to an increase in radioactivity caused by the thorium contents in monazite and allanite. Therefore, radioactivity can be used as an exploration tool to locate REE mineralization. Exceptions to this do occur with some less radioactive pegmatites and leucogranites containing high total REE contents (>1.5 wt.%), whereas some highly radioactive biotite-rich pegmatites have <0.5 wt.% of total REE.
Field and petrographic examinations show that the Ivan-Dante Zone has a semi-continuous pegmatite of abundant monazite and zircon with the highest discovered radioactivity and REE mineralization at the Alces Lake property. Monazite-(Ce) is characterized by 5.43-10.54 wt.% ThO2, incorporated largely by the substitution Th4+ + Ca2+ = 2REE3+, while zircon contains 1.03-1.48 wt.% HfO2. U-Pb geochronological analyses yielded an age of 1926±3 Ma for zircon and 1926±15 Ma for monazite, which confirm their crystallization during the Taltson Orogeny.
Therefore, the Alces Lake pegmatite-hosted REE mineralization is not a placer, but most likely had a late magmatic-hydrothermal origin related to Taltson-aged leucogranites. The leucogranites most likely formed from anatexis as a result of granulite-facies regional metamorphism during the Taltson Orogeny and were evolved to produce pegmatites and associated hydrothermal veins containing REE mineralization. The fold hinges and faults at Alces Lake provided the conduits for focused emplacement of the REE-mineralized pegmatites and hydrothermal veins
Guide to Common Parasites of Food Fish Species in the Northwest Territories and Nunavut
Get PDFGlobal Water Futures supported by the Canada First Research Excellence FundNon-Peer ReviewedPrepared by N. Zabel & Dr. H. Swanson, Wilfrid Laurier University, and reviewed by
Dr. G. Conboy (DVM, PhD, DACVM), Atlantic Veterinary College, University of
Prince Edward Island. Preparation of this guide was supported by Northern Water
Futures (Global Water Futures; Canada First Research Excellence Fund). Reviews,
photographs, and expert guidance was received as in-kind support from several
individuals, and we gratefully acknowledge these important contributions.
Funding for printing of guides distributed within Northwest Territories was provided by Government of Northwest Territories
Cyclization of Polyphenols from Natural Products: Potential Pharmacological and Toxicological Implications
Get PDFPreviously our group identified that the dicatechol lignan nordihydroguaiaretic acid (NDGA) can undergo spontaneous autoxidation and intramolecular cyclization at pH 7.4 to form a dibenzocyclooctadiene (cNDGA). We also observed that autoxidation of NDGA or cNDGA was required for inhibition of -synuclein aggregation in vitro, a protein associated with Parkinson’s disease.
A number of dicatechol ethanes have been shown to inhibit -synuclein aggregation in vitro and we propose that the anti-aggregation effects are the result of autoxidation/ intramolecular cyclization. My first goal was to determine if dicatechol ethanes could spontaneously autoxidize/ cyclize and inhibit -synuclein aggregation in vitro.
In order to assess the formation of 6-membered ring dicatechols, I synthesized and characterized three diphenylethane analogs with 0, 2 or 4 methyl groups on the 2-carbon linker. I determined that all of the analogs spontaneously cyclize at pH 7.4 into the corresponding dibenzocyclohexadienes which were also oxidatively labile and formed additional oxidation products. The rate of cyclization to form dibenzocyclohexadienes is 10-30 times faster than for dibenzocyclooctadienes and both the diphenylethanes and dibenzocyclohexadienes inhibit -synuclein aggregation in vitro.
A second goal of my project was to study the metabolism of quebecol, a triphenylethane natural product isolated from maple syrup production which is under investigation as a chemopreventive and chemotherapeutic, although there are no reports on the hepatic metabolism of quebecol. In order to assess hepatic metabolism, I synthesized and isolated quebecol and investigated its in vitro metabolism in rat liver microsomes (RLM) and human liver microsomes (HLM). I anticipated that phase II metabolism would predominate, and I observed formation of three glucuronide metabolites in both RLM and HLM. To determine the hepatic contribution to first-pass glucuronidation, I validated an HPLC-UV method following FDA and EMA guidelines (selectivity, linearity, accuracy and precision) to quantify quebecol metabolism in microsomes. In vitro enzyme kinetics were performed for quebecol glucuronidation in HLM including 8 concentrations from 5-30 M. I determined a Michaelis-Menten constant (KM) of 5.1 M, intrinsic clearance (Clint) of 0.04 mL/min/mg and maximum velocity (Vmax) of 0.22 mol/min/mg.
In contrast I was unable to detect any P450 metabolites of quebecol in either RLM or HLM. In spite of the presence of three phenols that could form para-quinone methides, glutathione (GSH) trapping experiments provided no evidence for reactive intermediate formation. To confirm the absence of para-quinone methides I attempted to prepare standards using MnO2 as oxidant and trapping with GSH. Rather than observe the expected para-quinone methides, instead I observed ortho-quinone formation resulting from MnO2-mediated dealkylation. Together with extensive phase II glucuronidation, this suggests that the risk of reactive intermediate formation from quebecol is negligible