University of Saskatchewan Research Archive
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Assessing the impact of oilfield development on native grassland ecosystems with remote sensing
No full textThe native grassland ecosystems in the Canadian prairies, which have been reduced to remnants, continue to be threatened partially as a result of human activities such as agriculture and a significant increase in oilfields from oil exploration and production. The development of oilfields on grasslands often leads to the fragmentation and conversion of native grassland vegetation into oilfields. This is still an increasing trend with newly established oilfields and some of them becoming inactive. The total area occupied by the oilfield is relatively small, but the fragmentation and the effects on vegetation and soil at local and landscape levels for the ecosystem can be significant but are not fully understood. The research focused on understanding the effects of oilfields on native grassland ecosystems with remote sensing techniques, using Monet pasture in the mixed-grass ecoregion of Saskatchewan as the study site. Furthermore, the oilfields were identified and extracted from remotely sensed data using object- and pixel-based image analysis procedures. The spatio-temporal changes of oilfield disturbances in grasslands (over a period of 6 years) were also evaluated, and the local effects of oilfields in grassland were investigated using spectral vegetation indices derived from satellite images to assess vegetation and bare soil changes. The results indicated that a total of 48, 68, and 76 oilfields (distributed within 8 categories: abandoned, active, cased, completed, planned, preset, suspended, and uncategorized) were identified and extracted for the periods of 2016, 2019, and 2022, respectively, in the study area. Out of all the categories, the active oil well was sufficiently extracted. The area covered by the linear and non-linear oilfields increased by 101.6% and 119.1%, respectively (2016–2022). The grassland vegetation cover and water content at varying distances further away from the active oilfields increased and decreased in the study area; variations were observed at different distances (5–50 metres and 10–200 metres) further away from the active oil well and oil road in the years considered. This study will enhance the sustainable management of grasslands. It will also help researchers and grassland managers understand how to effectively identify and monitor oilfield disturbances in grassland ecosystems
Differential Controls of Greenhouse Gas (CO2, CH4, and N2O) Concentrations in Natural and Constructed Agricultural Waterbodies on the Northern Great Plains
No full textPublished by American Geophysical Union (2023)
© 2023. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Government of Saskatchewan (Award 200160015), Natural Sciences and Engineering Research Council of Canada Discovery grants (to K.F., G.L.S., H.M.B., and P.R.L.), the Canada Foundation for Innovation, University of ReginaPeer ReviewedInland waters are hotspots of greenhouse gas (GHG) cycling, with small water bodies particularly active in the production and consumption of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). However, wetland ponds are being replaced rapidly by small constructed reservoirs in agricultural regions, yet it is unclear whether these two water body types exhibit similar physical, chemical, and environmental controls of GHG content and fluxes. Here, we compared the content and regulatory mechanisms of all three major GHGs in 20 pairs of natural wetland ponds and constructed reservoirs in Canada's largest agricultural region. Carbon dioxide content was associated primarily with metabolic indicators in both water body types; however, primary production was paramount in reservoirs, and heterotrophic metabolism a stronger correlate in wetland ponds. Methane concentrations were correlated positively with eutrophication of the reservoirs alone, while competitive inhibition by sulfur-reducing bacteria may have limited CH4 in both waterbody types. Contrary to expectations, N2O was undersaturated in both water body types, with wetlands being a significantly stronger and more widespread N2O sink. Varying regulatory processes are attributed to differences in age, depth, morphology, and water-column circulation between water body types. These results suggest that natural and constructed water bodies should be modeled separately in regional GHG budgets
Synthesis and Characterization of Porous Nanoparticle Catalysts
Get PDFPlatinum (Pt) and palladium (Pd)-based heterogeneous catalytic systems are widely used for various essential chemical transformations, including small molecule hydrogenation and oxidation reactions. Current research in the fields of Pd and Pt-based catalysts focuses on developing sys- tems with high activity and selectivity. Recent studies in the field have indicated that metal-based porous nanocatalysts can demonstrate enhanced activity and selectivity due to the presence of voids in their structures. In a porous nanocatalytic system, both the interior and exterior surfaces of the structure are available for catalysis, leading to a significant increase in the number of active sites and overall catalytic activity. Moreover, the presence of pores within nanoparticle catalysts can im- prove the selectivity of reactions towards specific products. The main objective of this research is to prepare highly active and selective porous Pt and Pd-based nanoparticles through selective etch- ing of bimetallic nanoparticles (i.e., PtNi and PdNi). The catalytic activity of the resulting porous Pt nanoparticles for hydrogenation reactions is investigated. The structure and morphology of the nanoparticles are characterized using transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and extended X-ray absorp- tion fine structure (EXAFS) measurements. EXAFS measurements demonstrate that Ni can be nearly completely removed from the final PdNix and PtNix nanoparticles. Also, for PdNix NPs, the degree of porosity in the resulting porous particles can be controlled by the initial metal ra- tio and the coordination numbers determined from EXAFS modeling serve as an indirect method of measuring the relative surface area of the resulting catalysts. The extent of porosity in the Pt nanoparticles significantly influences their activity in hydrogenation reactions
The Effect of CUSFTA and NAFTA on Canada’s Export Composition
No full textThe abstract of this item is unavailable due to an embargo
Water Heroes : First Nation water treatment plant operators keep water flowing and their communities safe
No full textCanada First Research Excellence FundNon-Peer ReviewedPersonal account of a researcher's interactions with water treatment plant operators in Canadian Indigenous communities
Learner and Context Analysis
No full textThis handout is for use to conduct a learner and context analysis when designing a course.Non-Peer Reviewe
Moving up, Moving Green : Long-term mountain systems monitoring with a local tourism operator
Get PDFCanada First Research Excellence FundNon-Peer ReviewedPersonal account about a scientist's interactions with a local business that led to a new research facility in the Canadian Rocky Mountains
ʔeɬa ʔeghádalaída
Get PDFBackground of statement recommending ethical and culturally sensitive research practices developed at meeting of Indigenous partners in Global Water Futures research projects.Canada First Research Excellence FundColonialism and colonial governance and management systems have systemically excluded Indigenous Peoples and Indigenous Knowledge systems and science, including from water research. Researchers working in Indigenous communities should follow ethical and culturally sensitive research practices, based on the following principles: Wellness of community is a primary objective; Observe and abide by local protocols; Equity is needed in supporting and funding knowledge; Intellectual property will remain with communities who will determine what can be shared
Short Term Performance of Bituminous Geomembranes with Respect to Temperature Variations
Get PDFThere is a significant lack of independentunbiased, peer-reviewed research on the performance of bituminous geomembranes in barrier system applications when compared to the standard barrier polymers used in industry today. The purpose of the research presented in this thesis is to help form a foundation of objective data on BGMbituminous geomembranes (BGMs)s performance in the field, as well as to compare it to polymer barriers like high density polyethylene (HDPE)HDPE geomembranes, LLDPElinear low density (LLDPE) geomembranes, and other well known material types. In addition, in Saskatchewan, the temperature can vary by more than 60°C so a variety of climate conditions need to be considered when installing geomembrane covers. Due to temperature variability, the influence on temperature on the performance of bituminous geomembranes is one of the main variables considered in this research.
A variety of different testing methods were evaluated during this research including multiple ASTM standards for geomembrane puncture and tearing, and short-term performance testing; all with variations in temperature included in the testing procedures. The ASTM style testing methods used the ASTM designated apparatus, while the short-term performance testing was performed using equipment designed and manufactured in the College of Engineering Shops.
When evaluating the puncture resistances of both BGMs and HDPE geomembranes, it was found that as temperatures increase, the displacement required to cause puncture also increasesthere was a positive correlation between the ambient temperature and the amount of displacement that occurs prior to puncture. In contrast to this, the puncture resistance of the samples themselves decrease as temperatures increase, while there was a negative correlation between the puncture resistance of the samples and the ambient temperature. During the sub-zero experiments, it was observed that the stiffness of the geomembranes increased. Additionally, while HDPE geomembranes showed higher overall loads at the time of puncture, the BGMs deformed in much more elastic manners allowing them to reform into their original shape due to the viscosityductility of the bitumen binding, which could be highly beneficial in application.
When looking at the short-term performance of BGMs, in applications with the presence of aggressive over liners with the potential to cause puncture, it was found that both the ES2 and ES4BGM samplesproducts were able to withstand applied stresses of up to 400 kPa without any holes being caused in the barrier. Additionally, at lower temperatures there was little to no surface deformation present on the samples, with very minimal damage from the aggressive over liner.
Based on the findings of this research, it was observed that HDPE retains a higher resistance to puncture than BGMs, however the highly viscous nature of BGMs shows that it could have many advantages in short-term performance depending on the conditions in which it is used
Improving Hemocompatibility of Poly Ether Sulfone Hemodialysis Membranes Using Zwitterionic Materials
No full textThe abstract of this item is unavailable due to an embargo