82837 research outputs found
Sort by
Fabrication of Biocompatible Hydrogel Bead for Wastewater Treatment
No full textAdsorption of pollutants in water using renewable biopolymer hydrogels is a sustainable and cost-effective method of pollution control. However, traditional methods of hydrogel fabrication often rely on non-green solvents and environmentally toxic reagents, thus compromising sustainability. In addition, the limited tunability of biopolymer compositions limits scalability, efficiency, and cost-effectiveness. Lignin, an abundant but underutilized industrial by-product, is a promising alternative due to its low cost, abundance of adsorption sites (including hydroxyl and carboxyl functional groups), and inherent structural stability. Sulfur-rich kraft lignin (SKL) containing thiol (-SH) functional groups can improve adsorption properties. In this study, a liquid nitrogen-assisted phase change technique was used to cure gelatin-lignin (SKLGE) hydrogel beads rapidly, thus solving the existing difficulties in fabricating low-concentration gel solutions. By optimizing the experimental parameters for fabrication, this study aims to improve the adsorption efficiency, mechanical durability, stability, and regeneration potential, promoting the use of lignin-based biopolymers in water treatment practices.
The rapid low-temperature cooling process formed a thick shell and a porous internal gel network, which significantly improved the chemical and mechanical stability of the hydrogel beads. The adsorption performance of the hydrogel beads for the removal of Pb(II) ions from aqueous solutions was evaluated and showed that the optimal adsorption capacity of the 0.45 lignin/0.55 gelatin composition was 155 mg g-1. Incorporating lignin improved the mechanical integrity and prolonged the bead lifetime for 10 consecutive cycles at pH 6, compared to the decomposition of the pure gelatin beads after only three adsorption-regeneration cycles. Lifetime. A minimum dosage of 0.1 g of hydrogel beads at an initial concentration of 100 mg L-1 resulted in 96% Pb(II) removal, highlighting its utility in wastewater treatment.
To further enhance the structural and functional stability of the beads, amide and ester crosslinking reactions were introduced using N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC), a zero-length crosslinker. Upon optimization, 1 mM EDC crosslinking improved lead(II) adsorption capacity by 32% over multiple regeneration cycles compared to non-crosslinked beads, confirming the role of inter-polymer bonding in maintaining adsorption efficiency. The effects of the fabrication method and repeated adsorption-desorption cycles on the bead morphology were analyzed using cryo-scanning electron microscopy (cryo-SEM), providing insight into the structural evolution of the hydrogel network.
This study establishes an innovative, scalable, and sustainable approach to the production of high-performance hydrogel beads from industrial lignin by-products. By employing a green production process, this research not only improves the adsorption efficiency of hydrogels but also promotes the valorization of lignin, a largely underutilized industrial waste product. These findings help expand the field of biopolymer-based water treatment technologies and provide a greener and more economic alternative to traditional adsorbents such as activated carbon, carbon nanotubes, and graphene. Given the tunable composition, mechanical robustness, and regeneration capabilities of these hydrogel beads, they hold promise for large-scale wastewater treatment applications, including industrial wastewater remediation and decentralized water purification systems. Future research could further explore functional modification, life cycle assessment, and techno-economic analysis to optimize the practical application of these hydrogels for environmental remediation and resource recovery
The Zooarchaeology of kā-kī-māmawēpihk (EfNg-1)
No full textkā-kī-māmawēpihk (EfNg-1) is a Morlach phase, Pericolonial period site with occupations ranging from the 15th to 17th centuries. The site is located in a coulee near Last Mountain Lake in southern Saskatchewan. This site has been involved with many different eras of archaeological inquiry in Saskatchewan, from the early days of curious post-dust-bowl Saskatchewan farmers, the first archaeological survey in 1951, test excavations in the 1960s and 1970s, to field schools conducted in the 1990s. Mortlach pottery, lithics, trade goods, bone tools, ice-gliders, other modified objects, and thousands of fragmented faunal remains were recovered during looting and systematic excavations. Despite the intermittent work on the site over many decades, the large faunal collection has not been comprehensively and systematically analyzed. Now housed primarily between the Royal Saskatchewan Museum and the Canadian Museum of History, the assemblage has been minimally analyzed in the past, but the results are primarily unpublished. Using zooarchaeological methods, a clearer picture of the site’s activities and Mortlach subsistence strategies have been established. This thesis research resulted in the comprehensive and systematic analysis of the kā-kī-māmawēpihk faunal collections from the Royal Saskatchewan Museum and the Canadian Museum of History. Using the comparative collection at the University of Alberta, under the supervision of Dr. Robert Losey, the overall taxonomic composition of the assemblage was determined, with bison being the most prevalent, followed by canids (dogs, wolves, coyotes, and foxes). One of the most intriguing identifications were two horse elements, which are rare in pre-colonial archaeological assemblages in Saskatchewan. Through more thorough radiocarbon dating, a better chronology of the site was formed, which suggests a single occupation is highly unlikely. The seasonality of the site was better established using fetal bison specimens, which have indicated cold season occupation(s) ranging from November to April. Through the comparison of these results with other Mortlach phase faunal analyses, a general trend of cold season bison hunting and small animal trapping emerges. The identification of kā-kī-māmawēpihk as a primarily cold season site adds further evidence to support ethnographic and ethnohistoric descriptions of cold season hunting and settlement in this region of the Great Plains. This project has demonstrated the importance of revisiting old collections with new perspectives and new technologies
CFD analysis of fluid flow inside the human nasal cavity for use in an automated CFD tool to aid in the screening of Obstructive Sleep Apnea
No full textSurgical and non-surgical interventions may treat obstructive sleep apnea (OSA) in humans. A tool that can tell the pressure drop and airway resistance in the upper airways of a human before and after the orthodontic treatment can aid in screening upper airway problems in patients and help early diagnosis. Computational fluid dynamics (CFD) is one such tool that can help doctors accurately assess the impact of orthodontic treatment on nasal airflow in humans. Performing CFD analysis requires knowledge of CFD, and it takes time to set up the CFD model. Hence, there is a need for an automated CFD tool that efficiently uses computational resources and gives the pressure drop and airway resistance value. This automated CFD tool should be able to be operated by healthcare personnel without any need for knowledge of CFD. This automated tool should be built with a validated and tested CFD model that uses optimal computational resources. This CFD model should provide acceptable pressure drop and airway resistance results, which will help doctors determine whether their orthodontic treatment has yielded positive outcomes in breathing parameters.
The study aims to identify the most effective CFD model for the automated tool while validating and testing it. The primary objective of this tool is to evaluate the variation in pressure drop before and after orthodontic treatment in a patient's upper airway 3D model. To determine the best CFD model for the automated CFD tool, multiple assumptions are made by considering the airflow as steady, incompressible, isothermal, and the deformation of the soft palate and pharyngeal boundaries are minimal. The optimal CFD domain, along with the mesh size and domain dimensions, should be determined for the CFD model to accurately predict the pressure drop and use optimal computational resources. As the inhalation flow rate for the currently tested patients ranges from 5 to 100 LPM, a turbulence model must be chosen for the CFD model, and the pressure drop, flow behaviour and airflow structures within the upper airway need to be examined and compared with other research studies to validate the CFD model. Multiple CFD domains are tested to determine the best CFD model for the automated CFD tool. The upper airways CFD domain with a hemisphere modelled in front of the nose captures minor losses better than the upper airways CFD domain without the hemisphere. However, for finding the pressure drop difference between two UA 3D models, the upper airways CFD domain without the hemisphere is found to give the pressure drop difference value with acceptable accuracy while using fewer computational resources. CFD domain with a hemisphere is used for further studies in determining the best mesh size, domain size and turbulence model for validating the CFD model with experiments. For the turbulence study, eddy viscosity based two-equations turbulence models are chosen over the large eddy simulation model (LES), as even though LES produces results with high accuracy, it requires large computational resources. In this study, both the standard k-omega and SST k-omega turbulence models yield accurate pressure drop results and outperform k-epsilon turbulence models. These models have shown that the flow becomes turbulent at a flow rate of 15 LPM and above. At fully turbulent flow, recirculation is visible in the nasal cavity and Dean vortices are formed at the nasopharynx region. The finding shows that the CFD model can be used in automated CFD tools, and it can be used by healthcare workers to plan the treatment for patients suffering from sleep apnea
View Across the North Pond at the Clifford E. Lee Nature Sanctuary
No full textTaken from Sanctuary Road, just north of the parking lot, this photograph shows a wooden fence and Common Cattail (Typha latifolia) in the foreground and looks across the pond to the aspen forest beyond
Manal Kleib - Abstract 33 - Innovate Conference 2025
No full textThe American Nurses Association endorsed the nurse informatics (NI) scope and standards of practice in 2014, and revised it in 2022, outlining core responsibilities for nurses in general practice, and those at the advanced practice levels, i.e., nursing informatics specialists, also referred to as nurse informaticists (American Nurses Association, 2022). These nurses are experts in both nursing practice and technology, playing a crucial role in improving patient care outcomes. Yet, little is known about this role in the general nursing and healthcare literature
The Effect of Leisure Constraints and Leisure Facilitators on "Working-after-retirement" Older Adults' Leisure Participation
No full textBackground: The aging population is becoming a global concern. Leisure can benefit older adults’ well-being, which can help older adults pursue successful aging. Older adults usually have more free time after their retirement. However, more and more older adults choose to work after retirement age. In Canada, older adults who are 60 years old or older can receive the retirement pension from the Canada Pension Plan (CPP), but one in five Canadian older adults aged over 65 years were still working in 2015 (Statistics Canada, 2017). This “working-after-retirement” (WAR) issue has not received attention within leisure studies. WAR is a complicated issue. It may bring both leisure constraints, such as lack of energy, and leisure facilitators, such as having coworkers as leisure companions.
Objective: The purpose of my thesis was to investigate the relationship between leisure participation, leisure constraints, leisure facilitators, leisure motivation, and constraints negotiation among older adults who are experiencing WAR.
Methods: An online survey was conducted to collect quantitative data regarding leisure participation, leisure constraints, leisure facilitators, constraints negotiation strategies, and leisure motivation from older adults in Canada who experienced WAR. The survey was distributed to Qualtrics’ panelists. A total of 417 participants completed the online survey. All participants were aged 55 years or older. After data cleaning, the final sample size was 396. Models were adopted from previous quantitative studies about leisure constraints and facilitators (Hubbard & Mannell, 2001; Son et al., 2008; Son et al., 2024). Partial least squares structural equation modeling (PLS-SEM) was applied to evaluate the validity of the measurement models and the structural model, examine the explanatory and predictive power of the models, and compare the models.
Results: Eight modified constraints-negotiation models were tested in my thesis. The results indicated that leisure constraints were negatively related to leisure participation, while constraint negotiation and leisure motivation were positively related to leisure participation across all the models. I also found constraint negotiation partially mediated the paths between leisure motivation and leisure participation. The moderation effects of constraint negotiation and leisure constraints were not significant. All the models had weak explanatory power (.25 R2 < .50) based on Hair et al. (2011). The Mitigation and Moderation models had the highest PLS predictive power compared to linear regression model benchmark, while the Independence model was best among all the models in terms of BIC values.
Discussion and Implications: My results supported the Independence and Mitigation models proposed by Hubbard and Mannell (2001). The Dual-channel and Facilitators models developed by Son et al. (2008) and Son et al. (2024) were supported as well. My results did not support the hypothesized moderation effect of constraint negotiation, which is in line with the lack of empirical support for the Buffer model (Hubbard & Mannell, 2001). In terms of model comparison, my findings suggested that the Independence model was the best model considering theoretical consistency and predictive power, although the Mitigation and Dual-channel models were favored in Hubbard and Mannell (2001) and Son et al. (2008), respectively. In terms of theoretical implications, my results favored the Independence model the most. The findings also supported my assumption that leisure facilitators play the role that parallels leisure constraints in the constraint negotiation process. With regard to practical implications, the most commonly reported leisure facilitators and negotiation strategies were intrapersonal facilitators (e.g., my leisure activities are enjoyable) and skill acquisition (e.g., I try to learn new leisure activities), respectively. Knowing these facilitators and negotiation strategies can encourage older adults to pursue leisure better. My study also suggested providing leisure education programs for WAR older adults may be a promising avenue to support rich leisure lives within this population
Parent-Adolescent Perceptions of Parenting: Implications for Adolescent Adjustment
No full textParents and adolescents commonly experience increases in disagreements during adolescence. One possible reason for this rise in disagreements may be discrepant perceptions of parenting behaviors. Discrepancies that occur in high magnitudes, across parenting behaviors, and where parents report more positively than their adolescent, are often associated with negative adolescent adjustment and may co-occur with conflict. This study evaluated the extent to which parents, and their adolescents agree/disagree on various parenting behaviors. The sample consisted of 132 parent-adolescent dyads and results were analyzed using Pearson’s correlations, and polynomial regression with response surface analysis. The results revealed a significant interaction between parent and adolescent reports of punishment and monitoring related to adolescent internalizing difficulties. The direction of reporting was significant for acceptance and autonomy supportive behaviors such that associated outcomes were worse when parents reported more positively on these behaviors than did their adolescents. The magnitude of divergence was a significant predictor between reports of punishment and internalizing and externalizing difficulties, while the magnitude of convergence was a significant predictor between reports of punishment and externalizing difficulties only. The findings of this study, while preliminary, have implications for researchers and practitioners, and can inform future studies
The Influence of Nanoscale Dimensions on Oxygen Vacancies in Cobalt and Nickel Oxide Catalysts for Thermochemical Water Splitting
No full textAs global energy demand surges, reliance on fossil fuels poses significant environmental and sustainability challenges. To mitigate these issues, transitioning to renewable energy sources is imperative. Hydrogen, a clean and versatile energy carrier, emerges as a promising solution. With an energy density three times that of gasoline and the ability to produce only water as a byproduct, it is an ideal fuel. Hydrogen and fuel cells offer a clean and efficient energy solution for various applications, including transportation, stationary power, and portable devices. By reducing greenhouse gas emissions and enhancing energy security, hydrogen stands out as one of the most promising clean energy sources for a sustainable future. This thesis explores the characteristics of earth-abundant first-row metal oxide catalysts and their role in hydrogen production through low-temperature thermochemical water splitting. The research aims to develop efficient and cost-effective methods for hydrogen production, paving the way for a hydrogen-based economy. Two heterogeneous catalytic systems consist of CoOx and NiOx pseudo-spherical nanoparticles developed by using Co and Ni halide precursors. The catalysts were evaluated for their activity in water splitting reactions at 85°C using silicon powder as a mediator. The results demonstrate that both catalysts exhibited higher activity when they possessed higher oxidation states and surface defects such as oxygen vacancies. The synthesis involved three straightforward acid-base and redox reactions, making it suitable for industrial-scale production and cost-effective manufacturing. Notably, both CoOx and NiOx nanoparticles displayed remarkable stability under ambient conditions and upon\nthermal treatment. Surface characterization of metal oxide nanoparticles revealed a size distribution of the active nanoparticles ranging from 4 to 11 nanometers. A decrease in reactivity with increasing nanoparticle size and morphological changes, such as the loss of their spherical shape, was identified as a critical challenge. To optimize the catalytic activity of both CoOx and NiOx systems, parameters influencing nanoparticle size and morphology, including temperature, solvent volume, and the addition rate of oxidizing/reducing agents were systematically investigated.
The rate of hydrogen evolution determined by the thermochemical reaction between metal oxide systems, with each catalytic system displaying distinct activity levels. This research provides valuable insights into the design and optimization of highly active and stable CoOx and NiOx nanoparticles based catalysts for industrially hydrogen production
Drought Impacts on Soil Nitrogen Dynamics and Agricultural Management in the Canadian Prairies: Monitoring, Simulation, and Fertilizer Optimization
No full textThis research aims to enhance agricultural drought monitoring and optimize nitrogen (N) fertilizer application in the Canadian Prairies, addressing two key research questions: (1) how effective are soil moisture–based indices compared to traditional meteorological indices for monitoring agricultural drought, and (2) how does drought-induced residual soil nitrogen (RSN) affect nitrogen fertilizer requirements in subsequent cropping seasons? To answer these, the study first evaluated the Empirical Standardized Soil Moisture Index (ESSMI) against the Standardized Precipitation Evapotranspiration Index (SPEI) from 1980 to 2022, using remote sensing soil moisture data and crop yield records. Results showed that ESSMI captured localized soil moisture extremes more effectively than SPEI and explained slightly more variability in wheat and canola yields, highlighting its value for agricultural drought monitoring. The second component applied the Alberta Farm Fertilizer Information and Recommendation Manager (AFFIRM) to simulate how drought-induced RSN alters optimal fertilizer rates across wheat–canola and canola–wheat rotations under varying soil zones and economic scenarios. Simulations revealed that drought generally increases RSN, reducing fertilizer requirements in following seasons, though crop and fertilizer prices strongly moderated recommendations. Together, these findings advance understanding of drought-soil nitrogen interactions and provide practical guidance for precision agriculture, supporting resilient management strategies in drought-prone regions
Experimental Evaluation of Biochar as Supplementary Cementitious Material in Reinforced Concrete
No full textConcrete’s scale of use and the CO₂ intensity of cement production motivate the adoption of supplementary cementitious materials (SCMs) to lower clinker demand and negative environmental emissions. Biochar, a carbon-rich by-product of biomass pyrolysis offers a potential SCM pathway that pairs partial cement replacement with biogenic carbon storage. However, experimental data remain limited on how biochar affects reinforced concrete (RC) member behaviour and reinforcement–concrete bond for both steel and glass fibre-reinforced polymer (GFRP) reinforcement which leads to no clear design guidance with biochar for RC.
This thesis investigates the structural performance of reinforced concrete (RC) with biochar as a partial cement replacement. Biochar added at 4% and 6% by cement mass was evaluated in flexure, shear, and bar–concrete bond using steel and glass fibre-reinforced polymer (GFRP) reinforcement. Nine beams (2000 \times 300 \times 200 mm) were tested under four-point bending: six beams (three steel, three GFRP) were detailed for flexural failure, and three steel beams without stirrups were detailed for shear. Deformations and cracking were monitored using conventional and optical measurements. In parallel, eighteen bond-beam specimens (two bar types \times three mixes \times three replicates) were tested under four-point loading following RILEM guidance for bond strength assessment. Results show that, within the tested range, biochar does not compromise strength, serviceability, deformability, or reinforcement–concrete bond. The flexural response of steel-RC and GFRP-RC beams with biochar reached peak loads comparable to or higher than the control. Under service loads, deflections and crack widths met the limits in CSA A23.3:24, CSA S806-12, ACI 318-25, and ACI 440.11-22, with crack patterns similar across mixes. Biochar increased shear capacity of RC beams by ~30% with 4% biochar and ~40% with 6% biochar, where diagonal shear cracking load rose by ~37% with 6% biochar. With biochar, sectional shear predictions from CSA A23.3:24 and ACI 318-25 were conservative; a simplified strut-and-tie model also underestimated capacity. Bond tests showed biochar mixes achieved bond strengths on par with the control for both steel and GFRP. Steel bars yielded before pullout, while GFRP bond–slip responses exhibited a steep initial branch, a peak at small slips, and a stable post-peak plateau. Existing development-length baseline bond models captured similar trends with and without biochar. Overall, for the materials, dosages, and configurations studied, replacing 4–6% of cement with biochar produced RC behaviour consistent with conventional concrete and remained compatible with current North American design provisions. Broader testing over embedment length, cover, bar size, concrete strength, and element type is recommended to confirm generality