University of Saskatchewan Research Archive
Not a member yet
14369 research outputs found
Sort by
Catalytic Reaction of Ozone and Ethylene at Ambient Temperature: Ozonative Epoxidation and Deep Ozonation
No full textThe abstract of this item is unavailable due to an embargo
Exploring the Stability of Self-Compassion, Self-Criticism, and Grit in Professional Triathletes Within Training
No full textProfessional triathletes need to navigate a fine line of training for three sports along with the mental and physical challenges of trying to meet standards of performance in order to be successful. The purpose of my research was to observe, through an exploratory through a single case design (SCD) study, whether self-criticism, self-compassion, and grit fluctuate for professional triathletes over a 3-week training period in which they are trying to achieve performance standards. Two professional long distance triathletes completed pre- and post-test measures of self-compassion, along with daily reports of these same measures. A visual analysis of daily measures was performed, recealing a general lack of stability in the variables examined both within and across participants. While one of the two athletes did not meet standards on two consecutive days as a naturally occurring intervention point, differences in stability before and after not meeting standards were challenging to interpret and demonstrate the complexity in athletes’ experiences related to trying to achieve performance standards. It remains for future research to determine whether the daily fluctuations I observed are representative of “true” daily changes in the constructs themselves or a result of measurement error associated with using single-time measures (or a combination of both)
BALANCING OTIPEMISIWAK AND WAHKOHTOWIN: MÉTIS WOMEN AT ST. FRANÇOIS XAVIER, MANITOBA, 1790-1840
No full textCentering the principles of otipemisiwak and wahkohtowin, this thesis examines the role of Métis women in the development of the community of St. François Xavier. While recent historiographical shifts have emphasized community-engaged histories and women’s voices, the role of Métis women within the Red River region during the first half of the nineteenth century remains largely underexplored. This research addresses this gap by highlighting how women were instrumental in shaping the community’s identity during the period of 1790-1840. Utilizing the worldviews of otipemisiwak and wahkohtowin offers a nuanced understanding of how Métis women embedded these concepts into the collective identity, asserting their independence whilst nurturing kinship. Ultimately, this thesis sheds light on the enduring significance of Métis women’s leadership and their vital role in shaping Métis identity, offering a deeper understanding of the community of St. François Xavier as a whole
Optimisation of a Radiofrequency Electron Photogun
No full textThe thermionic electron source which injects electron bunches to the accelerating complex
of the Canadian Light Source (CLS) is ageing, does not produce electron bunches which
are frequency matched to a harmonic of the booster ring accelerating frequency, and is not
ideally suited to producing single bunches of electrons. To improve the single bunch injection
process and the overall injection efficiency, it has been proposed to install a high brightness
radiofrequency photogun as a secondary electron injector to the CLS linear accelerator. The
photogun which has been acquired by the CLS and is proposed to fulfil this need was not
constructed to resonate at 3000.24 MHz — the sixth harmonic of the CLS booster ring
accelerating field frequency — and as such the geometry of the photogun must be altered
such that the resonant frequency matches the sixth harmonic of the CLS booster ring. To
design changes to the photogun geometry 3D electromagnetic modelling software was used to
numerically simulate the electromagnetic field configuration within the photogun. Electrodynamic particle tracking software was used to predict the characteristics of electron bunches
produced by the photogun. Benchtop measurements using a vector network analyser were
performed to characterise the radiofrequency properties of the photogun. It was shown that
the photogun geometry can be altered such that the resonant frequency matches the desired
3000.24 MHz. The simulated electron bunches using the new field configuration were shown to
have kinetic energy of 3.2 MeV, bunch size less than 1 mm, normalised transverse emittance
less than 10 mm mrad, and an energy spread of 5 keV. These characteristics are appropriate for electron bunches which are to be injected into the CLS linear accelerator. The
work presented in this thesis indicates that the modified photogun is a suitable candidate
be installed as a branch line injector to the CLS linear accelerator. By including this re-optimised photogun as a secondary high brightness electron injector, the injection efficiency
can be improved by seamlessly transferring electron bunches from the electron source, to
the linear accelerator, to the booster ring by phase locking the harmonic frequencies of the
accelerating waves
Host Choice Selection in The Aster Yellows Pathosystem
No full textThe abstract of this item is unavailable due to an embargo
The Transformative Power of Self-Compassion for Women Exercisers
No full textAwareness of the challenges women face in feeling safe and comfortable in their bodies has grown significantly. Despite this increased awareness, body shame remains a prevalent experience. Research has shown that even brief moments of self-compassion can reduce body shame, decrease the reliance on physical appearance for self-worth, and promote appreciation for one's body as it is. However, understanding how self-compassion influences exercise behaviour and subsequent feelings about the body requires further exploration. My participatory action research study aimed to find ways to emancipate women’s relationship with exercise and their bodies and explore new ways of relating to themselves through movement. I worked with ten participants over three months, through workshops and group discussions. My findings revealed the profound impact of self-compassion in the context of exercise. The research process validated the relevance and pervasiveness of the challenges that exist by inhabiting a woman's body and highlighted the positive impact that results when everyone’s experience can be expressed and held in communion with other women. The findings supported the use of self-compassion concepts to challenge internalized narratives and cultural influences, fostering the courage to make authentic and meaningful changes in exercise beliefs and behaviours by adopting a kind and caring approach to oneself during exercise planning and engagement. Overall, the research revealed that while self-compassion created a space that enabled an alternate worldview, and one that inherently fostered the ability to turn toward oneself with care, the process was greatly enhanced through the group experience, shared vulnerability, resonance, mutuality, and common humanity, all fostering an ability to embrace one’s humanity
RESPONSES OF THE CANOLA (BRASSICA NAPUS L.) ROOTASSOCIATED MICROBIOME AND PLANT GROWTH TO SOIL PHOSPHORUS APPLICATIONS
No full textThe abstract of this item is unavailable due to an embargo
Towards High Throughput Determination of Biotransformation Rates of Chemical Mixtures Using Isolated Perfused Trout Livers
No full textIn the field of environmental risk assessment, aquatic contaminants are typically characterized by their persistence, bioaccumulation potential, and toxicity (PBT). Bioconcentration factor (BCF) is the most common metric for evaluating bioaccumulation potential and is frequently estimated using Quantitative-Structure-Activity-Relationships (QSARs) and other in silico tools. These methods can estimate BCF based upon the physicochemical characteristics of a chemical and the toxicokinetic parameters of a model organism for chemicals which do not undergo biotransformation. For chemicals which are actively biotransformed, whole animal in vivo exposures have classically been required to determine BCF for regulatory acceptance. Recently, in vitro substrate depletion assays have been adopted as an alternative to in vivo testing due to concerns of cost and ethics. The results of these assays have been met with doubt due to uncertainties involved with in vitro-in vivo extrapolation (IVIVE) methods required to bridge the gap between target organs of biotransformation such as the liver, and whole-organism outcomes. The overall objective of this thesis was to validate an IVIVE approach for estimating biotransformation in rainbow trout (Oncorhynchus mykiss) by using the isolated perfused liver method, which represents an intermediate between in vitro and in vivo.
The first study (Chapter 2) involved comparing direct measurements of hepatic clearance in the isolated perfused liver with in vitro determinations of clearance which were previously published as part of a collaborative international trial for the regulatory adoption of in vitro substrate depletion assays. This comparison was performed for the model biotransformation substrate chemicals pyrene, phenanthrene, 4-n-nonylphenol, deltamethrin, and methoxychlor. The hepatic clearance rate of these chemicals was determined in isolated perfused livers by measuring the difference between chemical concentration as it entered and exited the liver, giving a measure of chemical elimination due to biotransformation. Experiments were performed over a period of several hours to validate physiological performance, and measurements of glucose efflux and pH were used to confirm aerobic respiration and thus metabolic activity. In addition, the influence of protein binding on hepatic clearance was investigated by varying the concentration of bovine serum albumin (BSA) in perfusates spiked with chemical. Measured clearances were in good agreement with in vitro substrate depletion models coupled with an IVIVE approach which takes protein binding into account. Overall, this study indicated that uncertainty associated with current IVIVE models is likely due to extrahepatic biotransformation, variability in BCF test designs, and inaccuracies in partitioning estimates or other kinetic processes such as uptake across the gills, rather than the reliability of in vitro test methodologies.
The second study (Chapter 3) focused on expanding the domain of applicability of the isolated perfused liver method following validation in Chapter 2 as well as concurrent research investigating mixture experiments in ionizable organic compounds (IOCs). One of the primary concerns about bioaccumulation assessment methods regardless of in silico, in vitro, or in vivo approaches is the limited number of chemicals which have been successfully tested. To achieve the throughput needed by modern chemical risk assessment frameworks, a mixture experiment was performed using the isolated perfused liver model. This study used a chemical mixture obtained from the United States Environmental Protection Agency (EPA) as part of the EPA’s non-targeted analysis collaborative trial (ENTACT). This mixture contained over 500 chemicals, and the study utilized advanced high-resolution-mass-spectrometry (HRMS) methods to detect individual compounds in mixture at the very low concentrations required for mixture experiments. Hepatic clearance was determined for 20 substances in this mixture simultaneously, representing diverse classes of chemicals including pharmaceuticals, pesticides, and industrial chemicals. This study demonstrated that the isolated perfused liver method can be a valuable tool for bioaccumulation screening, and validated the performance of this model for diverse groups of chemicals.
Chapter 4 discusses the present state of bioaccumulation assessment with regard to biotransformed chemicals, focusing on the role of the isolated perfused liver method and the goals of validation and demonstration set out by this thesis. Many studies have focused on which factors involved in IVIVE drive the discrepancies between BCFs determined by in vivo exposures with those predicted by IVIVE approaches. The difference between chemical freely available for biotransformation in the systemic circulation in vivo versus in vitro has been identified as a source of uncertainty. This ratio has typically been assumed to be identical, as this assumption whilst mechanistically impossible leads to a more reliable prediction of BCF. In Chapter 2, it was demonstrated that the influence of protein binding on hepatic clearance can be incorporated into an IVIVE model to increase reliability, indicating that prior assumptions were inappropriate. Concerns over limited domain of applicability were addressed in Chapter 3 as well as in concurrent work involving IOCs, focusing on the high-throughput nature of these experiments in which six fish were used to screen 20 chemicals.
In summary, the isolated perfused liver model advanced in this thesis work has contributed to the field of bioaccumulation assessment by validating presently adopted in vitro assays. Furthermore, this work has expanded the chemical scope of methods developed to achieve high-throughput predictions of biotransformation, serving as the basis for incorporation into reliable IVIVE models
Extendable micro-service architecture for consensus protocol in applications based on Distributed Ledger Technology (DLT)
No full textThe abstract of this item is unavailable due to an embargo
Treatment of Black Liquor Produced From Wheat Straw Pulping Process
No full textWith the increasing number of pulp and paper industries, the production of black liquor, which is one of the main by-products of the pulping process, is also being increased simultaneously. The produced black liquor is toxic to human, aquatic life and the environment as a whole because of its high pH and alkalinity, hence, various ways for its treatment and management are being carried out, yet it has been mostly used as energy for fuels only. Furthermore, the black liquor produced, especially, in the wheat straw pulp and paper industry is found to contain high concentrations of lignin, silica, etc., and its poor biodegradability on the other hand hinders the performance of conventional biological degradation methods of wastewater treatment. Hence, this research incorporated the use of an electrocoagulation process as a pretreatment step, where the flocculating agent was generated by electro-oxidation of sacrificial anodes that removed pollutants in black liquor by electrostatic attraction. The study investigated its efficacy for the biological degradation of black liquor under anaerobic conditions with varying concentrations of black liquor.
This study included the optimization of the electrocoagulation process of pretreatment of black liquor with the help of the Response Surface Method in which pH (7-11), voltage (10-30 V), and electrolysis time (10-60 min) were used as the operational parameters and Chemical Oxygen Demand (COD), phenol, Total Solid (TS), Total Dissolved Solid (TDS), color, pH, and Specific Energy Consumption (SEC) were used as the analytical parameters. Proximate analysis, Klason lignin analysis, Thermogravimetric Analysis (TGA), Fourier-Transform Infrared Spectroscopy (FTIR), and X-ray Fluorescence were also carried out to understand the characteristics of black liquor samples. Finally, anaerobic digestion was carried out with both untreated and pretreated black liquor for 36 days with varying concentrations from (10% to 30%) to find out the effectiveness of electrocoagulation for biological degradation. The degradation of the black liquor was evaluated by the reduction of COD, pH, TS, and volatile matter (VM). Along with that, biomethane potential was also assessed during the process of anaerobic digestion of black liquor.
The overall optimum condition for electrocoagulation treatment of black liquor was initial pH 9, 20 V, and 35 min electrolysis time, which led to a successful removal of 49.40% COD, 43.61% phenol, 53.89% TS, 46.50% TDS, and 29.33% color and a reduction in alkalinity of the black liquor by 0.52 pH. The optimized condition of electrocoagulation resulted in a black liquor with 21,000 mg/L COD, 198 mg/L phenol, 19,690 mg/L TS, 7,000 mg/L TDS, 50.49 whiteness index and 8.48 pH . The operation was conducted with an average current output of 0.87 A and a current density of 33.02 mA/cm2. The specific energy consumption was found to be 1.98 kWh/kg of COD removal. Additionally, it helped reduce lignin by 71.85%, and volatile matter by 12.50% (dry basis) and 58.00% (wet basis). Overall, electrocoagulation treatment of black liquor followed by anaerobic digestion reduced the inhibition time and the retention time for gas production. The biogas yield obtained from 30% EC treated BL in 10 days optimal time was 185.14 mL/g of COD loading, which was double in value than that produced from the raw black liquor. When pretreated, gas yield increased by 40.00% and 99.50% for 10% and 30% black liquor concentration, respectively. 25.14% of COD, 13.43% of TS, and 35.34% of VM was reduced when 30% of pretreated black liquor was digested under anaerobic condition. Hence, this study incorporated the ability to treat black liquor produced in wheat straw pulp and paper industry by an integrated approach of electrocoagulation and biological degradation under anaerobic conditions