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Evaluation of Barley (Hordeum vulgare L.) Stem and Root Traits that Influence Lodging
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Examining Canadian Parents’ Attitudes Toward Outdoor Free Play
No full textFree, child-led play has been identified as a developmental requirement for all children (Brussoni et al., 2015; Grey, 2011; Gray et al., 2015; Piaget, 1962; Vygotsky, 1978; Yogman et al., 2018). Parents’ attitudes towards allowing and restricting outdoor free play opportunities have been found to be a leading factor in why children do not engage in outdoor free play like previous generations did (Clements, 2004; Kepper et al., 2020; Murray, 2018; Niehues et al., 2013). Parental attitudes appear to be influenced by many factors (i.e., Clark & Dumas, 2020; Holloway et al., 2018; James 2014) including the social context in which they live and raise their children (Kepper et al., 2020; Kracht & Sissons, 2018; Lee et al, 2015; Riazi et al., 2019). Parents have become increasingly uncomfortable permitting outdoor free play alongside the prevalence of single-child families, and family structures in which there has been less sibling support to build in peer relationships (Loebach et al., 2021; Pynn et al., 2019; Shaki et al, 2022). Therefore, the purpose of this study was to explore Canadian parents’ attitudes toward free outdoor play and how variations in the structure of families and social relationships may influence the extent to which parents allow or restrict their children’s outdoor free play. Six hundred and nine (609) Canadian parents completed an online version of the Parental Attitudes Towards Their Child's Recreation (PACOR) scale (McFarland et al., 2011, 2014) to explore attitudes towards outdoor free play. A 2-way analysis of variance (ANOVA) was used to determine if there were any significant differences between the means of the dependent variable (i.e., parental attitudes) and the groups of independent variables (i.e., family structure or number of children, reported community cohesion). Post-hoc comparisons were used to explore differences and interactions between the group means while controlling for the experiment-wise error rates using Bonferroni corrections (Wilkinson, 1999). Findings included parents of single children reporting the lowest comfort level ratings related to allowing their children to engage in outdoor free play opportunities. Parents who had more children reported more positive attitudes towards allowing their children outdoor free play opportunities. In relation to the student researcher created variable that sought to measure parents’ ratings of community cohesion by having participants respond to three questions, parental attitudes appeared to become more restrictive when there were more than two children in the family and when community cohesion was rated highest. This finding was most likely due to how the variable of community cohesion was created and analyzed (i.e., student researcher created variable may not be measuring the construct of community cohesion, arbitrarily set cut points). However, there are likely other factors influencing parental attitudes towards outdoor free play in more socially connected communities (i.e., peer pressure increasing societal expectations, etc.). These findings can help to improve our limited understanding of Canadian parents’ attitudes toward free outdoor play. Future research should consider how the construct of community cohesion could be better represented and measured, parents’ considerations of the importance of playmates in the absence of siblings, and the significance of community socialization for smaller families
YOUTH PERCEPTIONS ON LEARNING IN IMMERSIVE VIRTUAL REALITY: DEVELOPING AND ASSESSING ESSENTIAL SOCIOEMOTIONAL SKILLS
Get PDFThis qualitative study investigated youth perceptions of educational virtual reality (VR)
for developing socioemotional skills. A constructivist theoretical framework was utilized to
guide the research design according to five key elements: learning in relevant settings, the social
negotiation of learning, ownership in learning, multimodal representation, and metacognition. An
exploratory case study approach was used. A grade 8 class of 28 students were invited to
participate as the co-researchers for this study. The methods for data collection were semi structured artifact analysis, observations, surveys, and interviews. Research activities involved
guided exploration of sustainability issues in AltspaceVR, collaborative painting in
MultibrushVR, and an artifact contribution to a co-created learning experience in FrameVR.
Empathy was the most predominant type of social-emotional learning (SEL)
demonstrated by the co-researchers: Teamwork, creativity, and problem-solving skills were also
evident. The youth exemplified new empathetic insights and activism for people, the
environment, and animals based on their learning in immersive contexts. Findings indicate a
rationale for educational VR to include SEL competencies, which VR excels at through its
capacity for perspective-taking. The research activities within the virtual environments
contributed to the co-researchers’ sense of social presence through open communication,
affective expression, and group cohesion. Although the scholarly literature identifies
personalized avatars as influential for enhancing social presence in VR environments, there was
a lack of consensus on avatar value. The data collected in this study may serve as a basis for
further research on understanding the capacity of educational VR to promote empathy and SEL
in youth
Drivers of Productivity of Montane and Boreal Breeding Ducks
Get PDFAnnual rates of productivity in wildlife populations are influenced by climatic and biotic factors, and offspring production and recruitment are key components of population growth in many duck species. For lesser scaup (Aythya affinis; scaup), a species of conservation concern, productivity can be particularly influential to population growth, although our understanding of factors affecting production is incomplete.
I sought to identify local drivers of productivity in scaup and several other duck species by testing hypotheses related to: (i) spring phenology; (ii) local breeding-season weather; (iii) density dependence; and (iv) predator-prey dynamics. To test these hypotheses, I used long-term datasets from two distinct breeding areas: a montane site at Red Rock Lakes (RRL) Montana, USA, and a boreal site, the Yellowknife Study Area (YKSA) near Yellowknife, Northwest Territories, Canada. Ducks breeding at these sites have been studied for periods of 9 (RRL, scaup) to 26 (YKSA, multiple boreal duck species) years. I used age-corrected body masses of 5727 scaup ducklings at RRL and 26 years of annual duck pair and brood abundance counts at YKSA to assess annual variation in duckling quality (RRL) and productivity (YKSA).
Age-corrected scaup duckling body mass was lower in years of both early and late spring conditions (i.e., ice-out dates) at RRL. There was no effect of the timing of spring conditions on brood abundance at YKSA. Warmer local weather conditions in the pre-nesting period were positively associated with metrics of duckling quality (RRL) and productivity (YKSA). Brood-rearing weather conditions had a small positive relationship with duckling quality at RRL, but no relationship was found with brood abundance at YKSA.
I also related scaup duckling quality to the density of conspecifics at RRL. Age-corrected body mass of scaup ducklings was lower in years of higher duckling density, a pattern that is consistent with possible density dependent regulation of scaup productivity at this site. At YKSA, overall duck brood abundance increased more slowly than pair abundance (i.e. regression slope < 1:1), suggesting lower duckling production in years of higher pair density.
Finally, to test effects of predator-prey dynamics on duck productivity, I related annual duck brood abundance to a small mammal index, hare density and indices of fox and lynx at YKSA. I found a non-linear relationship between brood abundance and small mammals. Furthermore, brood abundance was consistently lower when hare density was high in the current and previous years, perhaps because predators prey on species unselectively when prey abundance is high. Predator abundance indices were not strongly correlated with duck productivity, but brood abundance had a weak negative relationship with lynx abundance.
My research identified several climatic and biotic mechanisms influencing productivity in ducks on breeding grounds across time and geographical range. It highlights the importance of long-term data to evaluate hypotheses at small spatial scales
Realising Global Water Futures: a Summary of Progress in Delivering Solutions to Water Threats in an Era of Global Change
Get PDFCanada First Research Excellence FundNon-Peer ReviewedOver the past six years the Global Water Futures program has produced a wide range of scientific findings and engagements with multiple types of potential users of the research. This briefing book provides a snapshot of some of the science advancements and user engagement that have taken place to date. Annual reports to the funding agency are the most up to date source of information: this compilation has been created from reports submitted by projects in 2022, representing both completed and current project work. The briefing book aims to provide quick access to information about GWF projects in a single place for GWF’s User Advisory Panel: we hope that knowing more about the research being produced will spark conversations about how to make the best use of the new knowledge in both policy and practice
Outspoken: The Lifeworld of Queer Women and Non-Binary Spoken Word Poets
Get PDFSpoken word and slam poetry have been said to encompass space for all marginalized and oppressed groups and, as such, are important for grassroots poetic activity. However, research on spoken word poets and their communities is limited. In this doctoral research, I employed a critical phenomenological approach in order to meaningfully grasp the ways in which queer voices seek recognition and empowerment through spoken word poetry. To do so, I reflexively probed the lifeworld of queer women and non-binary spoken word poets. Theoretical thematic analysis of 20 one-on-one semi-structured interviews was organized into one overarching theme, three themes, and nine subthemes. Overall, participants of this research used their art form to boldly communicate a queer sexual orientation and/or a gender identity that deviates from the norm; and as such, participated in Outspoken (Overarching Theme 1) existence. For example, spoken word afforded interviewees the opportunity to: confidence build; counter invisibilities; and, tackle homo- and transnegativity. Both queer-identified poets and Outspoken expression were common among spoken word spaces. Probing deeper into these queer ‘convergences’ (Subtheme 1), the ‘rhetoric’ (Subtheme 2) stemming from participants’ accounts revealed that of a ‘queer counter-public’ (Theme 1). While this counter-public was crucial in fostering Outspoken expression, poets also faced particular ‘quandaries’ (Subtheme 3) by virtue of their participation in these subaltern spaces. Relatedly, the ‘queer omnipresence’ (Theme 2) poets experienced at spoken word was significant, as they advantageously used spoken word for queer ‘explorations’ (Subtheme 4) and to detail their unique experiences with queer ‘liminalities’ (Subtheme 5). However, abundant Outspoken expression could also lead to undesirable effects or ‘constraints’ (Subtheme 6). Finally, the social and psychological implications of writing and performing emotionally charged and painful Outspoken expression are explored in ‘queer affliction’ (Theme 3). Many poets aligned Outspoken performances with the familiar concept of ‘catharsis’ (Subtheme 7), but these healing aspects were not uniformly celebrated. The frequency of ‘trauma sharing’ (Subtheme 8) at slam and spoken word was troubled by many interviewees, as was the ‘painfotainment’ (Subtheme 9) value of ‘dangerous’ Outspoken expressions. This theoretical analysis of experience-rich data can be used to improve upon the ways we document, understand, and support gender and sexually diverse beings and their subcultural activity
Synthesis of carbon nanotubes supported iron catalysts for light olefins via Fischer-Tropsch synthesis
Get PDFLight olefins including ethylene, propylene and butylene are the basics of many chemical products. As the demand for light olefins is dramatically increased and oil resources are limited, it becomes desirable to produce light olefins from other resources such as syngas. Syngas could be obtained from alternative feedstocks such as methane, coal, biomass, and plastic wastes. Fischer-Tropsch (FT) synthesis involves conversion of syngas to hydrocarbons. FT products at high temperatures are mainly gasoline and light olefins. In FT catalytic reaction, iron is preferred due to its low cost, high selectivity towards olefins and flexibility in terms of use for different ratio of H2 to CO in syngas feed. In this study, catalytic performance of iron catalyst was evaluated using molybdenum and potassium as promoters and carbon nanotubes (CNTs) as support. The study plan for this research was divided into four sub-objectives or phases.
In the first phase, catalytic chemical vapor deposition (CCVD) method was applied to synthesize CNTs using Fe/CaCO3 and acetylene as catalyst and hydrocarbon source, respectively. Applying response surface methodology, the optimum operating conditions were determined in CVD reactor for maximal yield and purity of CNTs. The effects of reaction time (30–60 min), reaction temperature (700–800 °C), and loading of the catalyst (10–30 wt% Fe) were investigated. 20Fe/CNTs-synthesized, 20Fe/CNTs-commercial, and 20Fe/Al2O3 were analyzed in terms of physio-chemical properties and FTS catalytic performance. The catalytic performance of Fe-based catalysts was investigated using a fixed-bed reactor at 280 °C under 2.0 MPa. 20Fe/CNTs-synthesized exhibited a lower rate of water-gas-shift (WGS) reaction compared with 20Fe/CNTs-commercial, with C2-C4 selectivity of 23.6% which is slightly less than that of its commercial counterpart. After 120 h time-on-stream under steady state condition, the higher activity was maintained by the 20Fe/CNTs-synthesized catalyst compared to the 20Fe/CNTs-Commercial and 20Fe/Al2O3 catalysts.
Electronic structural promoters such as K and Mo improve olefins’ selectivity and catalytic activity. Hence, in the second phase, CNTs synthesized by CCVD were used as support to obtain K- and/or Mo-promoted Fe/CNTs catalysts for light olefins’ production in FTS. A two-level full factorial design was applied for K- and/or Mo-promoted Fe/CNTs catalyst to investigate the effects of synthesis conditions including Mo/K mass ratio, ultrasonic time, and iron loading on light olefins’ yield. CO chemisorption and TEM revealed that molybdenum plays a significant role in metal dispersion, leaving structural defects on CNTs support.
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Additionally, H2-TPR confirmed that K as promoter facilitates reducibility of Fe/CNTs catalysts, which promoted CO conversion in FTS. Compared with the un-promoted Fe/CNTs catalysts, addition of molybdenum as a promoter increased light olefins' selectivity by 33.4%, while potassium led to an increase in CO conversion by 96.3%. The optimum formulation (0.5K5Mo10Fe/CNTs) obtained the olefins’ yield of 35.5%.
In the third phase the kinetic study of FTS was performed over the optimum bimetallic promoted catalyst (0.5K5Mo10Fe/CNTs) in a fixed-bed reactor by collecting experimental data over a wide range of industrially relevant reaction conditions (P = 0.68–4.13 MPa, T = 270-290 °C, H2/CO = 1, GHSV = 2000 h-1). Based on the adsorption of carbon monoxide and hydrogen, twenty-two possible mechanisms for monomer formation during Fischer-Tropsch synthesis were proposed in accordance with the Langmuir-Hinshelwood-Hougen-Watson (LHHW) and Eley-Rideal (ER) adsorption theories. Kinetic parameters such as activation energy, adsorption enthalpies of H2 and CO were estimated to be 65.0, -13.0, and -54.0 kJ/mol, respectively. Based on the developed kinetic model, the effects of reaction temperature and pressure were assessed on FTS product distribution. In addition, the Anderson-Schulz-Flory model was applied to further assess the reliability of the best fit mechanistic model for a wide range of hydrocarbon products.
In the fourth phase, techno-economic analysis (TEA) and life cycle assessment (LCA) of light olefin production in Fischer-Tropsch synthesis reaction were investigated via different scenarios. Data from a lab-scale experiment using the optimum bimetallic promoted catalyst (0.5K5Mo10Fe/CNTs) were used to simulate a plant to produce 1 kg of ethylene/h. The economic feasibility of light olefins production was estimated based on a comprehensive cash flow analysis. The net rate of return (NRR) was calculated to 5.6%, 7.4%, and 18.2% for the base scenario (scenario 1), scenario 2 with wastewater treatment, and scenario 3 with wastewater treatment-separation unit, respectively, which means the project is profitable from an economic perspective. The GHG emissions performance was measured as 77.5 g CO2-eq per MJ ethylene confirming the significant GHG emissions decrease compared to petroleum-based fuels production (3686 g CO2-eq per MJ ethylene)
Effects of the Deposition of Various Fines during Hydrotreating of a Bitumen Derived Gas Oil
Get PDFThe processing and upgrading of the Canadian Athabasca Oil Sands is necessary to meet the demands of a growing global economy in a world of diminishing reserves. As such, the reduction in operating costs is imperative to further increase the amount of economically feasible reserves. Hydrotreating is a secondary upgrading method which, at elevated temperatures and pressures in the presence of hydrogen and a catalyst, removes contaminants from the oil stream. This both improves the quality of the produced oil by increasing the H/C ratio and allows the contaminants to be processed at the upgrading facility rather than be vented as exhaust.
The purpose of this research was to compare the different types of fine particles that enter an industrial hydrotreating unit within a controlled setting. By comparing the catalyst activity and pressure buildup between mineral fines (namely kaolinite, montmorillonite, and pyrite), produced solids (petroleum coke), and corrosion products (iron (III) oxide), it was hoped that any discovered differences could be exploited through optimization of reactor conditions to lessen the quantity and/or impact of their fouling. This was performed using a laboratory-scale continuous-flow packed bed reactor, which is similar to the equipment used industrially.
By comparing the pressure profiles during accelerated fines deposition of the different types of fines, it was found that mineral fines would create the earliest pressure buildup, taking 7-10 days and having a maximum pressure growth of 2885 kPa. The expected mechanism for these fines is that the surrounding asphaltene layers would desorb under hydrotreating conditions, leaving behind the minerals that were not oil-wetting, and couldn’t be carried by the passing oil stream. As more of these minerals were left behind, flow channels were blocked, and a filter cake formed at the inlet of the reactor. The second category of fines to result in pressure buildup was petroleum coke, reaching a 1193 kPa pressure drop. The mechanism driving this is that, as the petroleum coke solids break apart, any heavy metals that were contained within are left behind on the packing. This leads to the formation of a filter cake overtop of the catalyst bed. The category that took the longest for pressure to appear was corrosion products, where it was found that Fe_2 O_3 was converting to FeS under hydrotreating conditions. This formed FeS was then fouling the reactor system. This took over 40 days to be observed, with a final reactor differential pressure of 336 kPa.
In analyzing the conversion of nitrogen and sulphur within the oil stream for each experiment, it was found that catalyst deactivation due to fouling was minimal, with the main impact to hydrotreater performance being due to the pressure buildup. The one exception to this was for the iron (III) oxide experiment, where the formed FeS improved catalyst activity. However, a significant amount of iron deposition was required to achieve the same benefits as the cobalt or nickel promotors that are typically impregnated onto the catalysts during preparation.
Finally, through analysis of the textural and surface properties of the catalysts before and after the fouling had occurred, it was determined that fouling only occurred along the outer surface of the catalysts, and none of the active sites within the pores were reached. This is primarily due to the relative size between the foulants and the catalyst pores. Catalyst specific surface area was between 140-148 m2/g for all samples.
Future research into this area should focus on optimizing reactor conditions to increase the period until pressure buildup occurs, as this is the first issue that a hydrotreater will experience due to the fouling of fine particles. Additionally, any research into possible methods for the removal of the asphaltene layer and filtration of the mineral fines prior to entering the hydrotreater could be considered as another avenue by which the reactor life cycle can be extended
Migration in the Spotlight: A Comparative Investigation of Behavioural and Energetic Responses to Artificial Light at Night in Nocturnal Migrant and Nonmigrant Songbirds
Get PDFArtificial light at night (ALAN) is a rapidly growing pollutant as it is currently outpacing the growth of its leading cause, urbanization. Varying levels of light pollution can generate a wide range of responses including physiological or behavioural changes reported in a growing number of species. Nocturnal migratory songbirds may be particularly vulnerable given their long-distance migration, which increases their exposure risk to ALAN during a potentially sensitive window. I hypothesized that increasing levels of ALAN may alter migratory behaviour and energetics of foraging and flight activity in both nocturnal migrant and to a lesser extent in nonmigrant birds. Here, I used a captive experimental study design across three seasons to compare the activity, behaviour, and energetics of two nocturnal migrant species, Gambel’s white-crowned (Zonotrichia leucophrys gambelli) and White-throated sparrows (Z. albicolis), and a nonmigrant species, the House sparrow (Passer domesticus). Birds were video recorded in captive trials conducted in spring, summer, and autumn seasons, testing a range of ALAN intensities (0.15, 0.5, 1.5 and 10 lux) relative to a dark control treatment (< 0.01 lux). ALAN had little impact on house sparrow activity which remained largely dormant at night. In migratory sparrows, I found an increase in nocturnal activity in response to increasing ALAN along with changes in observed patterns of migratory-specific restlessness behaviours (beak up and beak up flight). Migrants had a threshold response in migratory behaviours, where increasing light intensity stimulated migratory behaviour, but the highest intensity diminished it, suggesting 10 lux may be a threshold for behavioural compensation. Additionally, all birds gained mass in all seasons following ALAN exposure, except the migrants at the highest light intensity. Despite an increase in migratory activity and positive relationship between activity and overall energy expenditure measured using respirometry, neither nocturnal metabolic rate nor food consumption appeared affected by ALAN, though this may be due to low sample size. Diurnal behavioural changes or physiological compensation could also be an energy saving technique when exposed to ALAN. I speculate that ALAN may alter the circadian mechanisms that control seasonally appropriate nocturnal and diurnal behavioural patterns, and possibly reflects an acute stress response, producing the observed effects. ALAN-induced changes in behaviour and energetics of migratory species may have unknown consequences on migration success, survival, and fitness in the wild
Software Design Change Artifacts Generation through Software Architectural Change Detection and Categorisation
Get PDFSoftware is solely designed, implemented, tested, and inspected by expert people, unlike other engineering projects where they are mostly implemented by workers (non-experts) after designing by engineers. Researchers and practitioners have linked software bugs, security holes, problematic integration of changes, complex-to-understand codebase, unwarranted mental pressure, and so on in software development and maintenance to inconsistent and complex design and a lack of ways to easily understand what is going on and what to plan in a software system. The unavailability of proper information and insights needed by the development teams to make good decisions makes these challenges worse. Therefore, software design documents and other insightful information extraction are essential to reduce the above mentioned anomalies. Moreover, architectural design artifacts extraction is required to create the developer’s profile to be available to the market for many crucial scenarios. To that end, architectural change detection, categorization, and change description generation are crucial because they are the primary artifacts to trace other software artifacts.
However, it is not feasible for humans to analyze all the changes for a single release for detecting change and impact because it is time-consuming, laborious, costly, and inconsistent. In this thesis, we conduct six studies considering the mentioned challenges to automate the architectural change information extraction and document generation that could potentially assist the development and maintenance teams. In particular, (1) we detect architectural changes using lightweight techniques leveraging textual and codebase properties, (2) categorize them considering intelligent perspectives, and (3) generate design change documents by exploiting precise contexts of components’ relations and change purposes which were previously unexplored. Our experiment using 4000+ architectural change samples and 200+ design change documents suggests that our proposed approaches are promising in accuracy and scalability to deploy frequently. Our proposed change detection approach can detect up to 100% of the architectural change instances (and is very scalable). On the other hand, our proposed change classifier’s F1 score is 70%, which is promising given the challenges. Finally, our proposed system can produce descriptive design change artifacts with 75% significance. Since most of our studies are foundational, our approaches and prepared datasets can be used as baselines for advancing research in design change information extraction and documentation