Research Repository
LU|ZONE|UL distributes and preserves the scholarly work of LU faculty. It is a space for faculty to support the dissemination of knowledge created at Laurentian.
Electronic Theses and Dissertations (ETD) Repository This section preserves Master's theses and doctoral dissertations accepted at Laurentian University and is a mechanism for making this form of scholarly work widely accessible.
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Recent Submissions
Spatial ecology and sexual colour dimorphism in a central Ontario population of Spotted Turtles (Clemmys guttata)
(Laurentian University Library & Archives, 2025-01-10) Thibeault, Stéphane; Dr. Jackie Litzgus
Populations of endangered species distributed across variable environments may require site-
specific conservation. Ontario’s coastal populations of spotted turtles (Clemmys guttata) are
well-studied, but little is known about inland populations. I described the demography and
spatial ecology of an inland population of spotted turtles in Ontario using mark-recapture data
and radiotelemetry. The population’s sex ratio was skewed towards males; males also occupied
larger home-ranges and travelled greater distances than females. Bright colours often play a role
in signalling sex, and mate quality. Spotted turtles are sexually dichromatic in chin/eye colour;
females bear brighter colours than males. I tested the effect of female chin colour on male
spotted turtle mate choice using visual models and behaviour trials. Males were more likely to
mate with the models as chin colour brightness increased. Future research should focus on inland
female nesting behaviours, aestivation, and the role of chemical/tactile cues in turtle mate choice.
Geology, hydrothermal alteration and gold mineralization at the Ormaque Deposit, Abitibi subprovince, Val-d'Or, Quebec
(Laurentian University Library & Archives, 2024-04-23) Bhalla, Shalaila; Dr. Bruno Lafrance
Dr. Ross Sherlock
The Ormaque deposit is located within the renowned Val-d’Or mining camp of the Archean
Abitibi greenstone belt, Quebec, where the fault valve model for the formation of orogenic gold
deposits originated. Ormaque is hosted by a syn-volcanic intrusion, the C-porphyry, which was
emplaced in intermediate to felsic volcaniclastic rocks and flows of the ca. 2704 Ma Val-d’Or
Formation. The deposit consists of shallowly-dipping quartz-tourmaline-carbonate veins
associated with steeply north-dipping and east-striking reverse faults, containing few fault-fill
veins of similar composition. It differs from other deposits in the camp by the marked
predominance of extension veins over fault-fill veins. Reverse faults at Ormaque are severely
misoriented relative to the bulk tectonic shortening direction and can only be reactivated at very
low differential stresses and high fluid pressures. This favors the formation of extensional veins
over a wider range of differential stresses, explaining why Ormaque differs from other deposits in
the camp.
Strategies for supporting the mental health of students exposed to simulated learning activities: a systematic and immersive review
(Laurentian University Library & Archives, 2025-04-03) Slack, Jenny Nicole; Dr. Shelley Watson
The field of addictions and mental health is growing in Canada due to various
factors, including the high prevalence of mental health disorders and addiction, the
increasing awareness and recognition of the toxic drug crisis, and the rising demand for
mental health services as evidenced by lengthy wait times and shortage of accessible
and affordable health care professionals. As such, there is an urgent need to prepare
future practitioners with the necessary skills and knowledge to address the imminent
challenges and escalating changes within the field of addictions and mental health. This
research paper investigates the strategies essential for supporting the mental health of
students engaged in simulated learning activities within post-secondary addictions and
mental health programs. Given the importance of bridging theoretical knowledge with
real-world applications within this particular field of study, simulated learning activities
can serve as crucial components of contemporary education. This paper employs a
systematic integrative literature review methodology to answer the research question:
What strategies are needed to support the mental health of students exposed to
simulated learning activities in post secondary addictions and mental health programs?
A total of 26 articles were identified and reviewed for this analysis. Nine themes were
identified in the literature across three distinct stages of simulation design: development,
integration, and facilitation.
Harvesting microalgae using ceramic and polymeric crossflow membrane systems
(Laurentian University Library & Archives, 2025-02-12) Bao, Jie; Dr. John Ashley Scott
Harvesting microalgae from its growth media remains a challenge for the industrial
production of microalgal biomass and associated products. Harvesting microalgae,
specifically Scenedesmus sp., using crossflow ceramic and hollow fiber membrane techniques
is studied in this thesis. A bench-scale membrane harvesting system was designed and
operated with 0.2 μm, 0.45 μm, 0.8 μm and 1.4 μm ceramic membranes; and 0.1 μm, 0.2 μm
and 0.45 μm hollow fiber membranes. Notably, all of the tested pore sizes achieved 100%
microalgae biomass recovery for both types of membrane. The highest filtration flux achieved
was 184 L/m2/h, when using the 1.4 μm ceramic membrane at a crossflow velocity of 0.5 m/s.
For both membrane types, critical transmembrane pressure points existed, beyond which
further increasing the transmembrane pressure (TMP) did not result in higher filtration flux.
Since all the membrane pore sizes achieved the desired microalgae biomass rejection rate, the
importance of membrane operation needs to be taken into consideration. Among various
methods used to maintain operational efficiency, the use of backwash stands out due to its
advantages, including no required chemical addition, energy saving and ease of operational
design. Backwash effectiveness was affected by various conditions, including backwash
duration, flux and intervals. The most efficient backwash was obtained with the 1.4 μm
ceramic membrane, when the backwash flux was 2.0 times the filtration flux, with a 30
seconds duration and a 480 seconds (8 minutes) backwash interval. This increased the
filtration flux by 70%. Additionally, the 0.2 μm hollow fiber membrane demonstrated
significantly better filtration flux maintain ability compared to the 1.4 μm ceramic membrane,
an average of 2.5 times higher flux was observed from the filtration cycles.
Early risk prediction in acute aortic syndrome on clinical data using machine learning
(Laurentian University Library & Archives, 2024-04) Tavafi, Mehdi; Dr. Kalpdrum Passi
Dr. Robert Ohle
Advancements in machine learning present novel opportunities for early prediction of Acute
Aortic Syndrome (AAS) as a critical and life-threatening clinical condition and the identification
of critical features influencing this prediction. This study concentrates on integrating, cleaning,
and handling missing data from extensive clinical datasets sourced from 150 emergency
departments across Canada and the USA. Covering medical histories of nearly 150,000 patients
from 2021 to 2022, the dataset comprises categorical clinical variables. Additionally, the research
focuses on constructing predictive machine learning models utilizing various data-splitting
strategies and classifiers to optimize AAS prediction. Methodologically, the study encompasses
data identification, acquisition, exploration, processing, and feature extraction, followed by
dimensionality reduction using Principal Component Analysis (PCA) and other feature selection
methods such as Correlation-based (CFS) and Relief. The multiple imputations method and the
SMOTE method are utilized for handling missing and imbalanced data, respectively. The findings
demonstrate that employing the Relief-feature method with an 80-10-10 split ratio alongside the
Random Forest classifier yields an exceptional accuracy of 99.3%, surpassing alternative models..
Furthermore, this research addresses a prevalent challenge encountered by many researchers
regarding dataset size limitations, thereby facilitating the utilization of the integrated and prepared
dataset for research on AAS and other cardiovascular diseases.