oURspace
University of Regina Institutional Repository
The mission of the oURspace digital repository is to share and preserve the scholarly, creative, and cultural work produced at the University of Regina.
What are some of the benefits of depositing your works in oURspace?
- Increased access to your scholarly publications.
- Content is indexed and discoverable in Google Scholar.
- Compliance with open access funding requirements.
- Long term preservation of your work.
Please contact ourspace@uregina.ca if you have questions or want more information about oURspace.
Communities in oURspace
Select a community to browse its collections.
Recent Submissions
Using machine learning methods to estimate spruce tree crown and DBH from aerial imagery
(Faculty of Graduate Studies and Research, University of Regina, 2024-12) Zouaghi, Hamza; Peng, Wei; Khondoker, Mohammad; Khan, Sharfuddin
Spruce trees play a vital role in Canada’s forest ecosystems, which is widely used in construction,
paper production, and other industries. However, spruce trees are particularly susceptible to
wildfires, which pose a major risk to both natural landscapes and human settlements. Therefore,
to evaluate the spruce forest biomass volume is an important step to estimate its yield and
combustibility. This paper aims to use Machine Learning (ML) approaches to estimate the biomass
volume of spruce trees from aerial top-view images. Since the aerial images are only show the tree
crown shapes, we set up the relationship between tree crown diameter (TCD) and Diameter of tree
Breast Height (DBH), and this DBH can be further used to estimate the tree biomass volume. Here,
Spruce trees top-view images were taken by a DJI Mavic 3, at an altitude of 50m above ground.
We measured the actual TCD and DBH in the field. 2,155 spruce trees were labelled in our dataset
according to its location in the aerial images. The actual TCD values of 2155 samples were
measured with a Hypsometer device that uses ultrasound at the extremities of the tree branches,
which will be further used to compare and calculate the accuracy of the TCD values that are
measured from top-view images after our model training.
After experimenting with tree detection methods, we conclude that YOLO performed better than
MaskRCNN by 4%. And then we proposed two methods that use YOLOs: First method, a
combination of YOLOv5 bounding box to identify the trees and watershed technique to segment
tree crowns from aerial images. Compared to the second method YOLOv11 that uses instance
segmentation to segment the trees.
A study is conducted to showcase a relationship between TCD and DBH of the field measurements.
This linear relationship can be used to estimate DBH out of TCD and then could futher calculate
tree biomass volume with the estimated DBH.
Screening of polyamine solvents for co2 capture: Solubility measurement and modeling
(Faculty of Graduate Studies and Research, University of Regina, 2024-11) Zeinali, Fatemeh; Henni, Amr; Ibrahim, Hussameldin; Peng, Wei
This research aims to identify new promising amines suitable for industrial-scale CO2 capture from natural and flue gas streams. Ideal amines should exhibit high CO2 solubility and low regeneration energy requirements. The amines selected for this study feature multiple amino groups, including combinations of secondary and tertiary amino groups within their molecular structures.
The solubilities of two amines in CO2 were examined in this work: 1-[Bis[3-(dimethyl-amino) propyl]amino]2-propanol (BDMAPAP) and N, N, N', N', N''-Pentamethyl diethylene-triamine (PMDETA). The pressure decay method was used to measure and determine the solubilities. To fully assess the performance of these amines under varied circumstances, experiments were carried out at two temperatures (313.15K and 333.15K) with 10 wt.% and 30 wt.% concentrations and within a range of CO2 partial pressures.
Both amines' CO2 uptake findings were compared to those of other amine solutions under comparable circumstances, such as piperazine (PZ), 1-ethylpiperazine (1-EPZ), 1-(2-Hydroxy-ethyl)piperazine (HEP), and 1,4-Bis(3-aminopropyl)piperazine. The results showed that compared to these other amines, there was a greater uptake of CO2. N, N, N', N'-tetramethyl-trimethylenediamine (TMTMDA), N, N-dimethyl-1,3-propane-diamine (DMPDA), N, N-dimethyl-dipropylene triamine (DMDPTA), 3,3'-Diamino-N-methyl-dipropylamine (DAMDPA), and 3,3'-Iminobis(N, N-dimethylpropylamine) (IBDMPA) were also compared to see how these amines were absorbed at 313.15 K. Except IBDMPA; the results revealed noticeably greater CO2 uptakes for the amines under comparable circumstances. Notably, the CO2 uptakes were substantially higher than benchmark amines commonly used in the industry, such as piperazine (PZ) and monoethanolamine (MEA). The superior performance of these amines indicates a high potential for more efficient CO2 capture processes.
The model employed is the electrolyte Non-Random Two-Liquids (eNRTL) in conjunction with the Redlich-Kwong equation of state for the gas phase. PMDETA's average absolute deviation (AAD%) between the experimental data and the estimated values was 0.1%, 0.01%, and 0.008% for mole fractions, temperatures, and pressures, respectively. Similarly, for (BDMAPAP), the %AAD between the eNRTL model's estimated values and experimental data amounted to 0.15%, 0.03%, and 0.30% for mole fractions, pressures, and temperatures, respectively.
The GLE model facilitated the calculation of the molar heat of absorption using the Gibbs-Helmholtz equation. The examined amines exhibited lower molar heat than other amines, such as PZ, MEA, and DMAPA, offering critical insights into their thermal efficiency and energy requirements during regeneration. The molar absorption heat at infinite dilution of CO2 was approximately -43 kJ·mol⁻¹ for both amine solutions, which is significantly lower than that of other amines, including PZ and MEA.
In conclusion, the high CO2 solubility and favorable thermodynamic properties of BDMAPAP and PMDETA highlight their promise as efficient CO2 capture agents. These findings suggest that the selected amines could significantly enhance industrial CO2 capture processes, offering a potential pathway to more sustainable and cost-effective solutions for mitigating CO2 emissions.
Fabrication of PLA-hemp 3D printing filaments
(Faculty of Graduate Studies and Research, University of Regina, 2024-10) Uddin, Md. Nasir; Stilling, Denise; Khondoker, Mohammad; Mehrandezh, Mehran
This thesis focuses on the development and evaluation of polylactic acid (PLA) composites
infused with hemp fibers for 3D printing applications. The project aims to leverage the intrinsic
properties of hemp fibers and PLA to create a material that mitigates brittleness and enhances
biodegradability while maintaining mechanical performance and printability. The methodology
involves fabricating composite filaments from 2 mm PLA pellets and 0.4 mm hemp fiber particles.
Hemp fiber at varying weight ratios (5 wt%, 10 wt%, and 15 wt%) was extruded using a single
screw extruder. The optimal ratio was determined among these blends for maximum tensile and
flexural strength, and the structures on the fractured surfaces were observed under low
magnification. The filaments were studied under flexural and tensile mechanical testing, optical
microscopy analysis, Fourier Transform Infrared thermal profiling, moisture absorption, and
biodegradability analysis. The blends were compared with a commercial PLA filament for 3D
printing applications.
As a summary of the results, the composition of 5 wt% and 10 wt% hemp powder had
lower Ultimate Tensile Strength (UTS) than 100 wt% PLA filaments; however, this blend had
higher elongation and toughness. The highest tensile strength of 35 MPa occurred with the 95 wt%
PLA-5 wt% hemp fiber composition. Similarly, the flexural strength for the 95 wt% PLA-5 wt%
hemp fiber composition was 86 MPa, which was the highest among the composites, but lower than
100 wt% PLA. This composition showed a higher flexural modulus of 4 GPa which was greater
than 100 wt% PLA. For water absorption, all the composite filaments showed the greatest rate of
absorption during the first 1 hour. After the initial hour, no notable changes occurred. The 85 wt%
PLA-15 wt% hemp fiber had the highest absorption rate; indicating that increasing the fiber
percentage increases the water absorption. The biodegradability was studied using an enzyme-rich
FABRICATION OF 3D PRINTING FILAMENTS M. UDDIN
detergent which showed that 90 wt% PLA-10 wt% hemp fiber had the highest weight loss
percentage across all three concentrations which was over 20% which indicates that this
composition was more prone to biodegradability using this method than the other compositions.
The printability of the filaments was analyzed qualitatively using a commercial 3D printer.
A simple design for a “paper clip” was printed which requires both tensile and flexural strength.
The products were printed with ease whereby the filaments melted and flowed through nozzles of
0.8 mm diameter for fused filament printing.
Integrating stewardship and resource recovery: A dual-faceted analysis of e-waste and used oil management practices of Canadian provinces
(Faculty of Graduate Studies and Research, University of Regina, 2024-11) Tasnim, Anica; Ng, Kelvin Tsun Wai; Veawab, Amornvadee (Amy)
Canada faces significant challenges in waste management, driven by high per capita waste generation. To address these issues, the country has implemented various waste management stewardship programs aimed at improving waste collection and resource recovery. This study examines the crucial role of stewardship in managing e-waste and used automotive resources including used oil, filters and containers. By focusing on stewardship practices, it highlights how effective management can improve collection rates, enhance resource recovery, and strengthen financial performance. The analysis emphasizes the importance of stewardship approaches to handling these special waste types, illustrating their potential to reduce environmental impact while optimizing resource use across Canadian provinces. The first part presents a comprehensive analysis of e-waste collection and management trends across six Canadian provinces, focusing on e-waste collection rates, provincial stewardship model attributes, program strategies and budget allocations from 2013 to 2020. Temporal and regression analyses were conducted using data from Electronic Product Recycling Association reports. The analysis emphasizes the significant impact of stewardship model attributes on e-waste collection rates, with Quebec emerging as a standout case, showcasing a remarkable 61.5% surge in collection rates. Findings from group analysis reveal a positive correlation between per capita e-waste collection rate and the growth of businesses and collection sites in Western Canada. This highlights the potential benefits of a coordinated waste management approach, emphasizing the importance of shared resources and collaborative policies. Financial aspects of e-waste management are also explored, revealing opportunities for improvement in Saskatchewan and Manitoba, where average allocations to e-waste collection efficiency stand at 6.6% and 7%, respectively. A 40.5% decrease in e-waste collection rates was observed in British Columbia, indicating additional public awareness campaigns may be required, as an 8% decline in consumer outreach was observed during the study period. The first part recommends leveraging region-specific needs to establish a collaborative approach, enhancing e-waste collection efforts. The second part addresses a gap in evaluating the recovery management systems for used oil, filters, and containers. The performance of resources recovery was examined in four Canadian provinces from 2010 to 2022 within automobile industry. The collection rates of resources, financial performance, and temporal changes of two original indicators: Resource Recovery Per Vehicle (RRPV), and Expenses Per Vehicle (EXPV) were examined. British Columbia and Quebec had the highest collection rates of used oil, filters, and containers (mean ranging 83.0 to 92.9%). Despite having the lowest mean collection rate of used oil (71.0%) and filters (78.7%), Saskatchewan has significant RRPV for used oil (20.4 liters) and filters (2.12 units). Decreasing RRPV (-0.01 to -0.38) trends were identified in all jurisdictions, suggesting the need for targeted recovery strategies towards automotive sectors. A mild increasing trend of EXPV in all jurisdictions is observed (slope +0.02 to +0.08). Quebec exhibited the most efficient resource recovery, with EXPV ranging from CAD 2.4 to CAD 3.3 per unit vehicle. Profit margin analysis revealed consistently high margins of 8.6% in Quebec, contrasting with Manitoba's lower 1.32%. The lower profit margin may partly be due to higher administrative costs (16.2%). The findings highlight the potential benefits of the proposed RRPV and EXPV indicators in evaluating management systems for used oil, filters, and containers.
The impact of 3D printing on traditional construction supply chains: Challenges, benefits, and a proposed framework
(Faculty of Graduate Studies and Research, University of Regina, 2024-11) Sultana, Shahanaj; Khondoker, Mohammad; Khan, Sharfuddin; Kabir, Golam
The construction supply chain is surrounded by various challenges which hinder its effectiveness. The increasing need for housing due to the fast-growing population in North America is a matter of concern for decision makers. 3D printing or additive manufacturing is an emerging technology that is being considered as a potential solution to housing issues. The purpose of this study is to highlight the existing challenges encountered by traditional construction supply chains and the potential advantages that 3D printing, or specifically 3D concrete printing, can offer in overcoming these challenges with the help of mitigation strategies. In order to achieve this goal, a systematic review is carried out. This review revealed a total of eleven (11) obstacles concerning material, cost, and environment. Moreover, eight (8) benefits of 3D concrete printing were identified from various sources of literature. Literature also provided the groundwork for linking these challenges with the functions of the construction supply chain and the benefits that result from applying 3D printing. Expert validation for the challenges and benefits is achieved through the employment of exploratory factor analysis. Furthermore, an attempt has been made to show the structural relationship between the findings using interpretative structural modelling and the MICMAC method. This relational hierarchy has aided in identifying the most significant challenges and benefits to address. Finally, a framework based on literature has been proposed to demonstrate how these challenges, functions and benefits can interact within the construction supply chain. In this framework, mitigation strategies have been suggested to assist decision makers mitigate the impacts of these challenges on the functions of the construction supply chain.
Keywords: 3D Concrete Printing; Additive Manufacturing; 3D Printing; Construction Supply Chain; Challenges; Impacts, PRISMA, Systematic Literature Review, Interpretative Structural Modeling.