Open Theses & Dissertations
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Item 1,2-asymmetric induction in carbonyl compounds: a computational study(University of New Brunswick, 2019) Retallick, Jeffrey; Deslongchamps, GhislainIn asymmetric synthesis, it is important to reliably predict the major stereoisomeric product of a reaction. One such reaction is the nucleophilic addition to a carbonyl compound featuring an adjacent chiral carbon. Several reaction models exist in literature to predict the facial selectivity of these reactions. These models provide simple visual drawings to quickly predict the major product of such a reaction without requiring exhaustive quantum mechanical calculations. These models are used on a daily basis, and some models perform better than others, making it valuable to investigate which ones are the most effective. For the first time in this thesis, high-level computations have been performed on all of the literature models to verify their efficacy. The results of this thesis offers a definitive answer that the Felkin-Anh and Wintner models are the most effective, and that bent bond theory offers an interesting insight on the mechanics of these reactions.Item 3D graphene-like carbon structure evolution via microwave pyrolysis of hemp biomass: A feedstock-process-structure-property relationship study(University of New Brunswick, 2024-03) Asif, Farhan Chowdhury; Saha, GobindaGraphene, known for its exceptional properties, faces challenges in broad adoption due to high costs and limited yields, hindering its diverse applications. The utilization of unconventional feedstocks, such as hemp biomass, shows potential for creating a graphene-like carbon (GLC) structure – a close mimic of graphene with prospects for scaling up. This research combines the processing of 'petera' type lignocellulosic hemp biomass with high-temperature thermochemical treatment via microwave pyrolysis. Previous findings from a collaborative study between the UNB Nanocomposites and Mechanics Laboratory (NCM Lab) and the Bioenergy and Bioproducts Research Laboratory (BBRL) indicated a higher carbon fraction presence in hemp-processed biochar structures under medium-temperature microwave pyrolysis (up to 600°C). The current study distinguishes itself by optimizing material design and process conditions, targeting elevated pyrolysis temperatures. The research delves into the mapping of the GLC feedstock-process-structure-property relationship, providing insights into scaling up the results, requiring further process optimization towards industrial applications.Item 3D information supported urban change detection using multi-angle and multi-sensor imagery(University of New Brunswick, 2015) Jabari, Shabnam; Zhang, YunThis PhD research is focused on urban change detection using very high resolution (VHR) imagery acquired by different sensors (i.e. airborne and satellite sensors) and different view angles. Thanks to high amount of details provided in VHR images, urban change detection is made possible. On the other hand, due to the complicated structure of 3D urban environments when projected into the 2D image spaces, detection of changes becomes complicated. In general, change detection is divided into two major steps: I. Establishment of a relation between bi-temporal images so that the corresponding pixels/segment are related; this is called co-registration; II. Comparison of the spectral properties of the co-registered pixels/segment in the bi-temporal images in order to detect changes. As far as Step 1 is concerned, establishment of an accurate global co-registration between bi-temporal images acquired by the different sensors is not possible in urban environments due to different geometric distortions in the imagery. Therefore, the majority of studies in this field avoid using multi-sensor and multi-view angle images. In this study, a novel co-registration method called "patch-wise co-registration" is proposed to address this problem. This method integrates the sensor model parameters into the co-registration process to relate the corresponding pixels and, by extension, the segments (patches). In Step 2, the brightness values of the matching pixels/segments are compared in order to detect changes. Thus, variations in the brightness values of the pixels/segments identify the changes. However, there are other factors that cause variations in the brightness values of the patches. One of them is the difference of the solar illumination angles in the bi-temporal images. In urban environment, the shape of the objects such as houses with steeply-sloped roofs (steep roofs) cause difference in the solar illumination angle resulting in difference in the brightness values of the associated pixels. This effect is corrected using irradiance topographic correction methods. Finally, the corrected irradiance of the co-registered patches is compared to detect changes using Multivariate Alteration Detection (MAD) transform. Generally, in the last stage of change detection process, "from-to" information is produced by checking the classification labels of the pixels/segments (patches). In this study, a fuzzy rule-based image classification methodology is proposed to improve the classification results, compared to the crisp thresholds, and accordingly increase the change detection accuracy. In total, the key results achieved in this research are: I. Including the off-nadir images and airborne images as the bi-temporal combinations in change detection; II. Solving the issue of geometric distortions in image co-registration step, caused by various looking angles of images, by introducing the patch-wise co-registration; III. Combining a robust spectral comparison method, which is the MAD transform, with the patch-wise change detection; IV. Removing the effect of illumination angle difference on the urban objects to improve change detection results; V. Improving classification results by using fuzzy thresholds in the image classification step. The outputs of this research provide an opportunity to utilize the huge amount of archived VHR imagery for automatic and semi-automatic change detection. Automatic classification of the images especially in urban area is still a challenge due to the spectral similarity between urban classes such as roads and buildings. Therefore, generation of the accurate “from-to” information is still remaining for future researches.Item 3D motion-sensitised SPRITE MRI of hydrodynamic cavitation(University of New Brunswick, 2012) Adair, Alexander; Newling, Ben; Mastikhin, IgorA liquid flowing in a pipe will experience pressure variations due to changes in the pipe geometry (for example, the narrowing of the pipe diameter at a constriction). For a sufficiently fast flow speed, the local pressure can drop below the vapour pressure of the liquid, which results in the formation of bubbles (hydrodynamic cavitation). The measurement of this phenomenon requires a non-optical and non-invasive technique; therefore, it is well-suited for study with magnetic resonance imaging (MRI). MRI is an inherently three-dimensional technique that can be used to measure several parameters of the flow, including density, void fraction, and flow velocity. Three-dimensional void fraction and velocity images were acquired of a cavitating flow through a pipe constriction by using a motion-sensitised version of the Conical SPRITE MRI pulse sequence. As a pure phase encoding technique, SPRITE is well-suited to study fast, turbulent, two-phase flow systems (i.e. characteristics of cavitating flow). As far as we know, this combination of information is not available using any other measurement technique.Item 3D transient modeling of thin-film coated surfaces to predict the temperature and ablated areas during laser processing(University of New Brunswick, 2017) Naghshine, Babak, Baradaran; Kiani, AmirkianooshIncreasing the biocompatibility of biomaterials is a hot topic in biomedical engineering. Introducing new surface modification methods, that can just slightly enhance the biocompatibility can directly improve the quality of lives of thousands or millions of people all around the globe. The main goal of this thesis is to study laser processed thin film multilayer structures which can be potentially used for biomedical applications. In this thesis, the laser treatment process is numerically modeled to predict the temperature field and surface profile for each set of laser parameters including the average power, repetition rate and scanning speed. The model is successfully verified with experimental measurements. The same model was modified for laser processing of thin film coated metals. The results show that applying a thin film on the surface can completely change the temperature field and make the heat affected zone smaller or larger. A new surface modification method is introduced by combining laser processing and electrospinning technique. In this method, the surface is processed by laser beam and then it is coated with an electrospun thin layer. This method has potential applications in bone implant fabrication. The implant can benefit from excellent biocompatibility of the electrospun layer in short-term, before the fibers are degraded, as well as long-term biocompatibility of the laser treated surface. In vitro tests showed that, this method can improve the biocompatibility, especially when the laser processed surface is coated with nanoscale fibers. Furthermore, it is shown that, by applying the electrospun layer on the surface, the thermal conductivity of the surface is closer to human body’s conductivity. It makes it an attractive method for modification of dental implants, where the cells can be damaged while drinking a hot beverage. Additionally, antibacterial agents (e.g. silver and ampicillin) were added to the fibers as an antibacterial agent, to prevent implant infection.Item A battery storage system to support the frequency stability of grid-connected PMG-based wind energy conversion systems(University of New Brunswick, 2019) St-Onge, Xavier F.; Saleh, SalehOver the past few decades, the generation of electric power has become concerning for the environment. As a result, several changes to power systems have been introduced. Among these changes, is the significant integration of distributed generation units (DGUs). For, DGUs strive to offset conventional generation by utilizing renewable energy. Largely, this approach to generation has trended toward wind systems. Modern wind-energy-conversion-systems (WECSs) have favored variable speed permanent magnet generator (PMG)-based topologies. The relative novelty of PMG-based WECSs has emphasized challenges that have limited their applicability. Of these challenges, PMG electromechanical torque pulsations and point-of-common coupling (PCC) frequency instability are regularly regarded as the most troublesome. On one hand, PCC frequency variations are dependent on the stable delivery of power by the interconnected WECS. On the other hand, generator torque pulsations are a consequence of the extensive use of power electronic converters (PECs) in PMG-based WECSs. As of late, energy storage systems (ESSs) and novel PEC technologies are being recommended to overcome these challenges. This thesis aims to develop and evaluate a split-bus PMG-based WECS. The developed WECS includes a generator-charged and PCC-discharged battery storage system (BSS) to support PCC frequency stability, as well as a modified cascaded H-bridge (MCHB) generator-side PEC to reduces PMG torque pulsations. The developed system is modeled in simulation and constructed in laboratory. Several operating conditions of wind speed, power command, and BSS charging are investigated. Experimental performance highlights the developed WECS’s ability in suppressing PMG torque pulsations while minimizing PCC frequency variation.Item A Bayesian Poisson mixed modelling approach to survival model with compound Poisson distributed frailty(University of New Brunswick, 2016) Yu, Qing; Yan, Guohua; Renjun MaIn survival studies, a subgroup of subjects may have zero susceptibility to the event of interest. For example, some people may be immune to a certain disease. These kind of data occur widely in medicine, social science and environment studies. The frailties therefore consist of a mix of zero and positive values. This poses some challenges in data analysis as there is no standard distribution for the frailties. Our work is motivated by Ma et al. (2003 & 2009). They have presented a multilevel frailties Poisson model for the survival data. In this thesis, we propose a Bayesian mixed model for survival data with zero-inflated frailties. With our approach, the zero and positive frailties are modeled using a compound Poisson distribution in an integral manner. We use the Markov chain Monte Carlo algorithm (MCMC) and the Bayesian approach to estimate the regression parameters and the frailties. Two data sets, jail time data and third birth data, are used to illustrate our proposed method.Item A behavioral based detection approach for business email compromises(University of New Brunswick, 2019) Maleki, Nasim; Ghorbani, AliThe most recent infectious vector in email attacks is Business Email Compromise (BEC), which is an entry point for attackers to get access to an enterprise network and obtain valuable company data. According to the Symantec Internet Threat Security Report (ISTR), around 7,710 organizations are hit by a Business Email Compromise attack every month. A BEC is a type of phishing attack that criminals impersonate a person of authority in an organization (CEO) through spoofing or take-over accounts. Since spoofing techniques are detectable using SPF, DMARC, and DKIM, we proposed and implemented a behavioral-based framework for the detection of BEC when accounts or machines are compromised. This framework stops malicious emails on the sender-side because the lack of enough email of the sender on the receiver-side cannot result in a representative user-profile. Moreover, a compromised account or machine turns into a devastating weapon targeting many people. Hence it ought to be stopped from the sender-side, and the real owner should be notified of this disaster. Our framework in the experiment on Enron Dataset for all users has reached a total average of 92% and 93% for Accuracy and F1 score, respectively.Item A biomechanical assessment of New Brunswick’s patient handling techniques(University of New Brunswick, 2024-08) Kell, Luke; Albert, Wayne J.This experimental study examined the biomechanical demands associated with eleven patient handing techniques from two New Brunswick programs: “Back in Form” (BIF) and “All The Right Moves” (ATRM) to inform a new patient handling program for the New Brunswick acute care system. Techniques were divided into 3 blocks based on their movement patterns. Twenty-six healthy participants were trained in the techniques and performed them on a mock patient. Biomechanical and neuromuscular demands were assessed using electromyography, motion capture, dynamometry, and a modified Borg scale. Statistical analysis demonstrated minimal significant differences between techniques, except for two BIF techniques that outperformed in their tasks. Comparisons across techniques showed low variability and showed low risk of musculoskeletal injury when performed in the laboratory-controlled environment. Further research is needed to understand cumulative joint loading with repetitive patient transfers and the effects of fatigue related to performing repetitive patient handling tasks during a 12-hour shift.Item A Bloom filter based authentication scheme for vehicular digital twin(University of New Brunswick, 2024-03) Adeyiga, Olajide; Lu, RongxingThe rapid growth in the automobile industry and the competitive nature of industry players has necessitated a closer connection between vehicles and their owners. This work will explore indepth the use of a Bloom filter based mutual authentication scheme in a vehicular digital twin system. Currently research into digital twin of vehicles within the IoT space shows that vehicles require a constant means of communication with their digital twin while the digital twin also requires such means of communication with the IoVs and other Digital Twin systems. However, these systems exhibit significant security gaps. The system is currently prone to adversarial attacks like the replay, anonymity, linkability attacks among others. The goal of this research will be the implementation of an authentication scheme that provides secure connection between all entities within a vehicular digital twin network. This scheme will use user credentials and vehicle private features to achieve mutual authentication.Item A brief workplace intervention for anxiety sensitivity: Aiming to reduce risk for posttraumatic stress disorder in First Responders(University of New Brunswick, 2023-07) Newcombe, Breagh Clare; Olthuis, JanineFirst responders (e.g., paramedics, firefighters) are repeatedly exposed to traumatic situations in the course of their work, increasing their vulnerability for developing posttraumatic stress disorder (PTSD; Haugen et al., 2012). Although research has established the efficacy of psychotherapy for PTSD (Bradley, et al., 2005), less research has focused on risk reduction approaches. Because trauma exposure is often unavoidable for first responders, efforts to reduce risk of PTSD could focus on individual factors that increase risk for developing PTSD. Although many of these factors are immutable (e.g., gender, age, family history of mental illness), others, such as high anxiety sensitivity (AS), can theoretically be targeted and fortified through preventive interventions. The current study investigated the efficacy of a brief cognitive behavioural therapy for AS intervention vs. a waitlist control in reducing AS one week and eight months later, and subsequently mitigating the development of PTSD and related mental health symptoms eight months later. Participants were 170 first responders from the Atlantic provinces who were randomly assigned to either the intervention or waitlist control group. Participants completed a self-report questionnaire pre-intervention, one-week post-intervention, and 8 months later. Hierarchical linear regression (with both completer and intention-to-treat samples) revealed no group differences in AS at one-week nor PTSD at the eight-month follow-up. Results and recommendations specific to interventions involving first responders are discussed in detail.Item A case study describing the experience of three New Brunswick adults with prediabetes while partaking in a nurse-guided health promotion lifestyle intervention(University of New Brunswick, 2020) MacDonald, Roya Marie Louisa; Aquino-Russell, Catherine; Ghassemi-Kakroodi, ParisaThe number of individuals developing prediabetes and Type 2 Diabetes Mellitus (T2DM) in New Brunswick (NB) increases dramatically each year (Bilanzie & Rosella, 2017). This suggests that the current preventative strategies and management of these diseases may be ineffective (Hallberg, Gershuni, Hazbun, & Athinarayanan, 2019). Emerging research indicates insulin resistance is the hypothesized pathological condition underpinning prediabetes and Type 2 Diabetes (Crofts, Zinn, Wheldon & Schofield, 2015), and that it is the over-consumption of refined carbohydrates which is the prominent driving factor in the development of insulin resistance. Studies demonstrate that prediabetes and T2DM are reversible when adopting low refined carbohydrate and intermitting fasting therapy (Hallberg et al. 2019; Furmli, Elmasry, Ramos, & Fung, 2018). This study utilized a case study design method to describe the experience of three NB adult females with prediabetes. These three participants participated in a 4-week nurse-guided lifestyle intervention. The intervention included: a low refined carbohydrate meal plan, intermittent fasting plan, virtual education, and continuous nursing support. This case study research concluded that: a low refined carbohydrate diet and intermittent fasting intervention was adopted by all three participants with prediabetes; the nurse researcher positively influenced the participants; biomarker improvements were noted; the case study methodology approach allowed the nurse researcher's role to be interactive; and participants had common barriers to health behaviour change. These included time barriers, monetary barriers, and limited family and social support.Item A case study of the effects of climate change on seawater intrusion in coastal aquifers in New Brunswick, Canada(University of New Brunswick, 2012) Green, Nathan; MacQuarrie, KerryTo investigate the effects of climate change on seawater intrusion, a three-dimensional numerical model of density dependent groundwater flow coupled with solute transport was developed and applied to a coastal sandstone aquifer in New Brunswick, Canada. The model incorporated local topography, bathymetry of the surrounding tidal rivers and Northumberland Strait, stratigraphy from borehole and geophysical investigations, and well field characteristics. Based on predictions of climate change for the area, two scenarios for variations in groundwater recharge and sea level rise, and one for increased pumping, were applied in the model. Simulations were performed using various combinations of the scenarios to quantify the magnitude of the effects of these three factors. The maximum change in total dissolved solids at selected locations within the model during the period of 2011 to 2100 was used as the response in a 2³ factorial analysis. Results indicate that the relative importance of the three factors changes depending on the location within the aquifer. The effect of generally declining recharge was most significant at shallow to intermediate depths (i.e. less than 60 m below sea level), while the effect of increasing pumping rates was most important for a location relatively close to the well field. The effect of sea level rise was found to be significant only at the much deeper inland toe of the transition zone. This study suggests that sea level rise has the least significant effect (of the three factors considered) on future seawater intrusion in shallow to intermediate aquifers similar to the one investigated in this study. These results are supported by other recent studies that indicate the effect of sea level rise on seawater intrusion is negligible when freshwater flow in the aquifer is controlled by constant flux boundaries.Item A case study on the acceptability of a standing intervention among residents in long-term care settings(University of New Brunswick, 2022-04) McCain, Jamie; Bouchard, DanielleOlder adults living in long-term care institutions spend about 90% of their time sitting or laying down which can be linked to health conditions. Few studies explored if standing is deemed acceptable among adults in long-term care settings. The purpose of this case study was to explore how residents living in long-term care institutions accept a standing intervention and why or why not did they accept standing according to an acceptability framework. There were 10 participants interviewed after completing a 5-month intervention with standing sessions 100 minutes a week. Interviews, participant characteristics, and standing time was analyzed. Most residents seemed to accept the intervention by reporting a positive attitude, limited burden, good ethicality, intervention coherence, no opportunity costs, perceived effectiveness, and self-efficacy which aligned with the acceptability framework. Participants stood a median of 53% of the intervention. Standing seemed to be an accepted and novel intervention in long-term care.Item A climate history of the Gulf of St. Lawrence region: a climatic reconstruction of the nineteenth century and discussion of its implications(University of New Brunswick, 2012) Devor, Teresa; Parenteau, William; Bitterman, RustyThe nineteenth-century settlement and development of the Gulf of St. Lawrence region took place during the end of a climatic epoch referred to by climate historians and scientists as the Little Ice Age, the temporal and geographic contours of which have been questioned by recent scholarship. This thesis examines the sources that help us to understand the climate of the Gulf of St Lawrence region in recent centuries. It suggests that in this region, the Little Ice Age ended around 1880. Data on annual temperatures and growing season temperatures reveal that the climate of the nineteenth century was characterized by a warming trend and by significant short-term fluctuations in the climate of the Gulf of St. Lawrence region. The vicissitudes of regional climate influenced the historic experience of settlement and development. This study explores the consequences of climatic variability for agriculture and transportation, and points to additional avenues of inquiry.Item A cloud-based framework for smart grid data, communication and co-simulation(University of New Brunswick, 2021-10) Adeyemo, Gabriel; Kent, Kenneth B.Renewable energy has caused rapid advancements in electric power systems. The advanced grid is a smart grid with information and communication technologies and bi-directional flow of information. Data in a smart grid aligns with the characteristics of big data. Choosing the most efficient technology to manage data in the grid (real and/or simulation) is crucial to the performance of the grid. This project explores a framework that supports large scale power and network co-simulation and manages communication and data in smart grid co-simulation, real world smart grid systems and a combination of both using message-oriented middleware and cloud technologies. We designed and implemented a framework with RabbitMQ, Apache Kafka, OpenDSS, OMNeT++, Apache Spark, Docker and Kubernetes. We evaluate our implementation on accuracy, scale and usability with three applications including a demand-response application based on logistic regression. The results of our evaluation meet the goals defined for the research thesis.Item A cluster multi-spacecraft study of Earth's bow shock(University of New Brunswick, 2014) Alrefay, Thamer Yousef Saeed; Hamza, Abdelhaq; Meziane, KarimThe location, shape and motion of Earth’s bow shock are investigated using observations based on measurements made by the Cluster spacecraft quartet. Several bow shock crossings have been identified and carefully characterized according to relevant plasma parameters; a collection of 133 shocks has been selected and analysed using a timing method. The shock crossings cover orbits in which the spacecraft separation is of the order of ∼ 600 km or less. When present, the magnetic field fluctuations are suppressed using the conventional low-pass filtering technique prior to implementing timing method. The results of this investigation are compared with both Gas Dynamics and Magnetohydrodynamics (MHD) bow shock models.We have found, on a statistical basis, that the shock standoff position derived from the timing method agrees well with the Gas Dynamics predictions for high Mach-number cases only. We have also found that for half the crossings, the timing and the conic-based shock normals agree within an 11 degree-angle. Our results strongly indicate that the motion of the shock is predominantly along the Sun-Earth direction; a departure from this direction is not related to the shock-crossing location. Shock velocities below ∼ 80 km/s satisfactorily follow a nearly Gaussian distribution with zero mean and a standard deviation of ∼ 42 km/s. We show that high speed motions are correlated with sharp increases in the solar wind upstream ram pressure, and are consistent with gas dynamics model predictions.Item A compact power supply for dielectric barrier discharge devices(University of New Brunswick, 2016) Allen, Brad; Saleh, Saleh; Colpitts, BrucePlasma generation by dielectric barrier discharge (DBD) devices has recently become a topic of interest for researchers due to the growing number of industrial applications. Some applications of note include: generation of ozone gas for disinfecting and cleaning, aerodynamic flow control over an airfoil, light emission for plasma displays and CO2 lasers, and others. The emergence of these new applications, specifically aerodynamic flow control for aeronautical applications, has created significant need for adaptable, compact and lightweight power supplies. The majority of the required high-voltage and high-frequency AC supplies employed by DBD devices have been based on resonant-type power electronic converters (PEC’s). Nonetheless, resonant PEC’s typically are neither small nor lightweight, which make them less desirable for supplying DBD devices in aeronautical applications. In addition, resonant PEC’s are generally not adaptable as their AC outputs are produced over a narrow frequency range, and their operation requires complicated control schemes. In this work, the size and weight requirements of a DBD device for aeronautical applications will be achieved using multi-stage and multi-level switch mode PEC’s. The multi-stage structure will consist of multiple DC-DC step-up PEC’s supplied from batteries. These DC-DC PEC’s will feed a multi-level DC-AC PEC, which will be operated to produce high voltages over a wide range of high frequencies. The DC-DC and DC-AC PEC’s will be operated using switching signals generated by digital signal processing (DSP) platform in order to ensure high quality AC outputs. Moreover, desired switching signals will be generated to facilitate adjusting the magnitude and the frequency of the output AC voltage. Such adjustments will allow manipulation of the DBD body force and/or the plasma velocity, which alters the thrust and/or the boundary layer separation. This work focuses on the design, construction, performance testing, and optimization of the size and weight of a power supply for a DBD device for aeronautical applications. Modeling and simulation tests have been conducted for various operating conditions. An experimental prototype was constructed for performance evaluation of the multi-stage and multi-level power supply, test results are reported and compared to the predictions.Item A comparative assessment of cognitive loading on gait patterns of lower limb dermoskeleton users(University of New Brunswick, 2017) MacDonald, Alexa; McGibbon, Chris; Noble, JeremyThe objective of this thesis was to assess the impact of a verbal fluency cognitive loading task and obstacle crossing on gait biomechanics of dermoskeleton users. Twelve participants with equal sex distribution were recruited and underwent a timed-up-and-go (TUG), cognitively loaded TUG (CL-TUG), an obstacle-cross TUG (OC-TUG) and a cognitively loaded obstacle cross TUG (CLxOC-TUG) in three different EXO conditions: KControl (no exoskeleton), KPassive (unpowered exoskeleton) KActive (powered exoskeleton). Motion analysis was performed for TUG time, turn radius, turn time, sit time, rise time, stride length, step width, and toe clearance. CL and OC conditions were found to impact results in KActive and KPassive mode similarly. Small, statistically significant increases were found in TUG time, turn time, turn radius, stride length and a decrease in toe clearance. The results demonstrated that overall, cognitive loading from dual-task and obstacle crossing while wearing the Keeogo™ minimally impacts gait biomechanics of the user.Item A comparative study of invertebrate food web structure in two adjacent tributaries of the Slave River with divergent chemistry(University of New Brunswick, 2020) Hussey, Beverly; Baird, Donald; Soto, DavidThis study examines benthic invertebrate assemblages of two contrasting river systems: the Salt River and Dog River, adjacent tributaries of the Slave River, located near the town of Fort Smith, Northwest Territories. The study sites, located in different ecoregions, express contrasting geophysical and geochemical characteristics: the Salt River draining karst geology and the Dog River draining Canadian Shield geology. Prior to this study, these two rivers were relatively unstudied by scientists, despite their significance for water and cultural resources to indigenous people of the area. At the time of this study, interest in exploring the potential use of these sites as part of the CanadaAlberta Oil Sands Monitoring program was being explored. The purpose of this study was therefore to gain baseline knowledge about these systems for future biomonitoring purposes. The objectives of this thesis were to examine and compare community composition, taxon richness and prevalence, and trophic structure of the benthic invertebrate communities. Results showed significant differences in taxon richness, prevalence, and trophic structure of the benthic assemblages between the two rivers. The results suggests [sic] that the geophysical and geochemical differences between the two rivers led to differences between the benthic invertebrate communities.