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Erosion Detection in Potash Pipelines Using Dynamic Pressure Response and Machine Learning
Get PDFErosion in pipelines can result in leakage if not monitored and maintained properly. Hence, it is very important for pipelines transporting slurries to conduct pipeline health condition monitoring continuously. In theory, erosion can be detected by inserting a pressure impulse and measuring the delay time of the reflected wave as the level of erosion and its distance to the pressure source can affect the reflected wave speed. This research is focused on investigating the possibility of this innovative continues pipeline condition monitoring method, which could change the future of pipeline health monitoring techniques, in different flow regimes and in the presence of non-idealities.
The Method of Characteristics is used to simulate pressure responses in the inlet of an arbitrary eroded pipeline. Equations of continuity and momentum are solved for both laminar and turbulent flow using frequency-dependent friction terms from the literature. The impact of non-idealities such as varying temperature, noise and limited bandwidth of pressure transducers and flow sources are studied for the laminar flow. Turbulent flow of potash brine in an eroded pipeline is then used to generate the turbulent dataset. Transient pressure response in pipelines with turbulent flows including all three regions of smooth, transition and fully rough is then compared to the pressure response of the laminar flow.
Machine Learning is used to extract important features in the transient pressure signal of an arbitrary eroded pipeline and learn the relationships between erosion parameters (severity, length, and location) and the reflected pressure wave. In real-world applications such as erosion detection in potash pipelines, inserting and receiving pressure signals can be performed by using pressure transducers at the two ends of each test segment.
Results from this study showed that with the represented continuous condition monitoring technique, high-cost smart pigging inspection can be decreased significantly. This method is able to detect the severity, length and location of an eroded section in pipelines even under non-ideal conditions such as varying temperature, presence of noise and limited bandwidth of the transducers and flow sources for both low and high Reynolds numbers. However, the accuracy of each parameter varies according to the studied non-ideality. Overall, thickness detection has the highest accuracy among all three erosion parameters. This is suitable because we can classify erosion with the represented continuous method and only use smart pigging inspection or other costly techniques when needed
Antimicrobial use and resistance in Canadian cow-calf herds
Get PDFAntimicrobial resistance (AMR) is a concern to human health and has been a growing concern for the public and livestock producers in recent years. The existing literature regarding antimicrobial use (AMU) and AMR in cow-calf herds, a critical component of the beef supply chain, is limited and much of it is more than a decade old. The goal of this thesis is to address the existing gaps by examining AMU practices on Canadian cow-calf operations and AMR in two enteric species important to human health: E. coli and Enterococcus.
In Chapter 2, a survey was used to collect AMU data from herds across the country. AMU data for the period of July 1, 2019, to June 30, 2020, was collected from 146 herds. Ninety-nine percent (145/146) reported the use of an antimicrobial at least once during the study period; however, frequency of use within herds was low. The antimicrobial most likely to be reported as used by participating herds was oxytetracycline (81%, 118/146). Category I antimicrobials were used at least once by 33% (48/146) of herds, with no herds reporting treatment of more than 30% of animals with a Category I antimicrobial. Factors such as calving season and herd type were shown to influence AMU practices. Overall, AMU practices were similar to previous studies examining AMU in cow-calf herds.
In Chapter 3, AMR patterns in fecal E. coli were examined in samples collected from cows and calves in the spring and fall of 2021 from western Canadian herds. In total, 1,551 E. coli isolates were obtained from 809 calves and 746 cows, resulting in an isolation rate of 99.7%. AMR susceptibility testing was completed using the NARMS panel for gram-negative bacteria. Overall, 15% (231/1551) of the recovered isolates were resistant to a single antimicrobial. Resistance was found at least once in nearly every herd (90%, 35/39). Resistance of E. coli to Category I antimicrobials was very infrequent, with tetracycline being the most common resistance target. Calves were more likely to display resistance than cows, with a higher proportion of calves also displaying multiclass resistance. Additionally, calves in the spring were more likely to display resistance compared to calves in the fall.
In the fourth chapter, antimicrobial resistance patterns were described for Enterococcus. Enterococcus has not previously been studied in Canadian cow-calf herds. Recovery rates for Enterococcus were good (97%), with 1,505 isolates recovered from 1,555 animals consisting of 809 calves and 746 cows. Resistance of isolates to at least one antimicrobial was 98% in the spring and 96% in the fall. The antimicrobials of quinupristin/dalfopristin and tetracycline were common resistance targets in both cows and calves. When summarized at the herd level, multiclass resistance and resistance to Category I antimicrobials was greater in calves than in cows. AMR resistance in Enterococcus is complicated by questions regarding the role of intrinsic resistance in observed susceptibility data. There are also concerns that current minimum inhibitory concentration (MIC) breakpoints are not accurate for all Enterococcal species further complicating the interpretation of the study findings. Future studies will be required to better understand the prevalence of resistance amongst different bacteria of interest in cow-calf herds
Improving Experimental Outcomes in Kinome Microarrays Through Quality Control
Get PDFPeptide microarrays consisting of defined phosphorylation target sites are an effective approach for highthroughput
analysis of cellular kinase (kinome) activity. Kinome peptide arrays are highly customizable
and do not require species-specific reagents to measure kinase activity, making them amenable for kinome
analysis in any species. However, the data emerging from experiments with kinome peptide arrays exhibit a
large amount of variability. To mitigate this issue, we introduce PIIKA 2.5 to expand upon existing software
by providing three important quality control features in an aim to increase the accuracy and consistency
of kinome results, which often suffer due to the aforementioned variability. The first feature concerns the
size of the virtual circle drawn around each probe in microarray analysis software (spot size). This circle
creates the boundary between pixels interpreted as foreground signal and pixels interpreted as background
signal. In this thesis, it is shown that too large of a spot size creates abnormal data characteristics, such as
high skewness (the asymmetry of the distribution of the data), that can alter downstream results. Here, a
feature is presented that alerts users to the existence of improper spot size and informs them of the need to
perform a manual alignment to enhance the quality of the raw intensity data, based on the skewness of the
data as determined by examination of the mean and median of each dataset. The second feature uses interarray
comparisons to identify outlier arrays that sometimes emerge as a consequence of technical or unknown
issues. The work shown in this thesis indicates that the removal of said outlier arrays improves downstream
analysis and interpretation. The third feature is a new background correction method, background scaling.
Here, it is demonstrated to sharply reduce spatial biases in comparison to the most popular background
correction method, background subtraction. Collectively, the modifications presented in PIIKA 2.5 allow
users to identify low-quality data, improve clustering of treatment groups, reduce unintended effects, and
enhance reproducibility in kinome analysis. The web-based and stand-alone versions of PIIKA 2.5 are freely
accessible at http://saphire.usask.ca/saphire/piika
An Exploration of Academy Deans' Responsibilities in Five U15 Research-Intensive Universities in Canada: Ambiguities and Managerialism in the Academe - A Mixed Methods Research
Get PDFThis study examined the responsibilities of academic deans within five U15 research-intensive universities in Canada as they operate in an increasingly complex environment. The academic deans who are sometimes flaunted as Chief Executive Officers, were found to be consummate academics who transitioned from their academic discipline into administration as middle managers. Academic deans have a dual responsibility in that they are accountable to the senior leadership of their university while being advocates for their colleges. Significantly, the responsibilities of these academic middle managers are central to the achievement of their universities’ strategic objectives. However, the position of the deanship is described by researchers as complex, and the very nature of the duality of the role engenders ambiguities. The ambiguities and complexities of academic deans’ responsibilities are said to be influenced by public sector reforms disguised as managerialism.
Some practices espoused by managerialism appear to be integral to universities’ strategies globally, whether as an ideology or through processes and practices. Universities in Canada are also adopting various strategies which are said to be driven by managerialism (Brownlee, 2015). Symptomatic of managerialism are various changes in university governance, including the professionalization of the roles of middle managers, now referred to as chief executive officers in some institutions, and the implementation of marketing techniques (Brownlee, 2015; Kolsaker, 2008; Olssen, 2002). Additionally, and as indicated in the literature, reflective of managerialism are the demands for accountability, efficiency, and effectiveness which are achieved through practices such as increased competition, a focus on marketization, and engagement of private-public partnerships. According to the literature, the practices espoused by managerialism in higher education institutions (Meek et al., 2020; Seale & Cross, 2016) have shifted the responsibilities of academic deans to a type of management that is reflective of corporate-style management practices and evidenced by various corporate terminologies. Given the tenets of managerialism, the argument obtains that some principles of this ideology are translated into practices and have contributed to the evolved roles of academic deans. They now engage in business-like practices, the processes of their institutions’ strategic planning initiatives, establishing public-private partnerships, and marketization, among others.
The changes have impacted how academic deans interpret, understand, and enact their roles, which are oftentimes imbued with role conflict and ambiguity due to competing demands and unclear expectations by various constituents (Arntzen, 2016; Boyko & Jones, 2010; Hoyle & Wallace, 2005). With the evolved responsibilities of academic mid-level managers, more specifically academic deans who are at the centre of this study, there is evidence of job enlargement as well as increased complexities in their roles. As such, in examining academic deans’ responsibilities, this study gathered information on academic deans lived experiences and perceptions of the presence of managerialism in their institutions and how their responsibilities reflect practices akin to managerialism. That is, responsibilities that mirror management techniques usually employed by the private sector or corporate organizations. The study further examined academic deans’ perceptions of role conflict and role ambiguity and how their perceived self-efficacy and tolerance-intolerance of ambiguity influence how they navigate the complexities of their roles.
The study’s findings were limited to the perceptions of the participants who indicated that some of their responsibilities are reflective of practices such as budgeting and fund development; strategic planning; advancement/fundraising/establishing donor relationships; advertising/marketization and human resource management, among others. According to the narratives provided by the academic deans in this study, they found themselves ill-prepared for important corporate-like responsibilities, which they indicated generally do not coalesce with their academic disciplines. Further, the findings revealed that the practices that characterize the responsibilities of these middle-level managers/chief executive officers are delineated by varying degrees of uncertainties and ambiguities which are defined by role conflict and role ambiguity. However, the academic deans in the study demonstrated that having a sense of self-efficacy and a high tolerance for ambiguity had been valuable in helping them to navigate the complexities of their roles as they engaged the corporate-like management imperatives of their responsibilities.
The research was grounded in the constructivist paradigm through a qualitatively dominant cross-over (Frels & Onwuegbuzie, 2013) mixed-methods research design. This process captured the subjective experiences of academic deans to gain an in-depth understanding of the practices of academic deans as they carry out their functions in an ambiguous environment characterized by managerialism (Arntzen, 2016; Ayers, 2012; Bess, 2006). Data were collected to address the research questions using a mixed methods sequential design over two phases. Phase one of this study focused on gathering quantitative data from surveys through SurveyMonkey. Phase two concentrated on the qualitative method of collecting data by way of reviewing position descriptions of academic deans, policy documents governing deans, and elite interviews with deans.
The study has implications for further research initiatives, research-into-practice, and contribution to theory. Implications for future research include comparative research with larger sample sizes across U15 research-intensive and non-research-intensive universities to garner a more comprehensive understanding of academic deans’ perceptions of managerialism, role conflict, and role ambiguity. The study findings have potential implications for institutions’ policies governing academic deans’ recruitment and professional development of academics, including the establishment of management career pathways and succession planning initiatives
Thomas Becket in the South English Legendaries: Genre, Materiality, and Why the Reader Matters
Get PDFThe South English Legendaries (SEL) is a thirteenth-century collection of saints’ legends. More than just a work of hagiography, this collection demonstrates late medieval genre hybridisation and literary experimentation in the legend of St. Thomas Becket, the twelfth-century martyred arch¬bishop of Canterbury, which exhibits a variety of genre-bending tropes. This project explores how poets incorporate the genre expectations of hagiography, historiography, and romance to capture the attention of a broad audience. The presence of these genres in the legend of Becket corresponds to three traditional perceptions of Becket: as a religious figure, a historical figure, and a legendary figure. Drawing on the fields of “New Philology,” genre theory, and reading reception theory, es¬pecially Jauss’ “horizon of expectations,” I argue that the SEL is a work of “edutainment” and explore the dynamic relationship between readers and their concepts of genre. I identify three types of readers—authors, scribes, and manuscript users—across three different stages of the SEL— composition, compilation, and reception—and examine how genre informed interpretation. The SEL poet participated in both secular and religious literary traditions to captivate a broad audience, while the scribes who copied, compiled, and disseminated the Becket legend employed paratextual manuscript features to encourage specific interpretations. Three historical figures, Robert of Gloucester, Sir John Prise, and Sir Robert Cotton, provide evidence of reading engagement to show how interpretations of the Becket legend evolved. The SEL Becket legend was composed as a romance, disseminated as a saint’s life, and read as a work of history
Variable suction and its effect on stability at the Ripley Landslide near Ashcroft, British Columbia
Get PDFThe high concentration of landslides south of Ashcroft in the Thompson River valley of British Columbia, Canada has periodically affected operation and maintenance of track infrastructure for both of Canada’s primary railway operators as far back as written historical records exist. Historical site investigation and study of the landslides in the region previously identified the primary controlling factors for landslide displacement. However, the arid climate of the region causes a large portion of the landslide head scarps to be unsaturated and minimal study has focused on the consequences of climatic variation that drive soil water content changes in the vadose zone. The research program focused on a heavily instrumented and recently active landslide in the Thompson River valley, known as the Ripley Landslide.
The study collected soil samples for unsaturated material characterization, instrumented and monitored the near-surface soil water content changes, compared these changes to annual displacement trends, and developed a 3D modelling framework to establish the impact of variable soil suction on stability at the Ripley Landslide. The research methodology began with a field program to install matric suction sensors, including low-cost dataloggers. Soil samples recovered from the borehole investigation were used to determine the unsaturated material properties. Collection of meteorological observations over several years were interpreted in relation to displacement rates. Records from historical borehole investigations, geophysical surveys, and instrumentation monitoring were incorporated into a 3D model of the Ripley Landslide.
Investigation during the research program provided a detailed description of the upper till unit present at the Ripley Landslide. Soil classification and behaviour estimates provided inputs that were vital to the stability model. Interpretations from matric suction monitoring and climatic variables documented their influence on historical displacement rates. New investigation techniques (such as ERT, SMD, and stable water isotopes) provided further evidence for increased soil water content in the head scarp tension cracks that contributed to deeper infiltration. 3D limit equilibrium and 3D finite element models estimated groundwater movement, within a set of known criteria, and determined that matric suction contributed at least 4% to the overall factor of safety. Meanwhile, the river buttressing effect increased the factor of safety by at least 11%. As a result, a loss of suction, coinciding with low river level, was found to be a significant destabilizing factor at the Ripley Landslide. Research contributions from the study improved our understanding of the interrelated factors driving landslide displacement rates and are generally applicable to other landslides in the Thompson River valley. Impacted railway operators may use the knowledge presented in this thesis to identify hazardous conditions leading to increased maintenance and landslide risk throughout the Thompson River Valley rail corridor
Exploring the Potential of Action Mechanics in Video Games for Stress Recovery
No full textDigital games can provide effective recovery from stress, with players turning to a variety of genres—including those with game mechanics that can be considered stressors themselves, i.e., action mechanics. We examine whether action mechanics undermine or facilitate game-based recovery by exposing participants (n=60) to a stress induction, then having them play a roguelike game in one of three conditions: Combat-Required, Combat-Optional, and Combat-Free. We assess experience through self-report and observed physiological responses. Our findings suggest that gameplay—irrespective of action mechanic intensity—supports recovery through the pathways of experienced psychological detachment, control, dominance, and pleasure. Additionally, action mechanics offer superior facilitation of experienced mastery—but undermine the recovery pathways of relaxation and arousal reduction, also reflected in subjective stress. Physiological measures corroborate subjective self-report. We contend that video games featuring action mechanics represent a promising strategy for stress recovery, and may uniquely aid the re-assertion of mastery
Systems Science Approaches to the Opioid Crisis: Exploring its Multifaceted Nature through Agent-Based Model Simulations
No full textAlthough opioids prescribed for medicinal purposes have shown temporary pain relief, they can lead to severe physical and psychological effects, addiction, and even death due to misuse, abuse, addiction, and overdose. The euphoric effects of opioids can drive individuals to seek street opioids, leading to a cascade of consequences that extend beyond personal health and are accompanied by a negative societal stigma, which can impede efforts to overcome the vicious cycle.
The central features of the opioid crisis reflect its complex nature, which can be effectively understood through the application of systems science methods. Purpose-specific simulation models can be created to replicate the key characteristics of the opioid crisis and used to analyze the behavior of the system, identify potential unintended consequences of different policy options, and evaluate alternative strategies. This work contributes three agent-based models, each addressing a different facet of the opioid crisis.
The first model examines the impact of COVID-19-related school closures on nonmedical prescription opioid use among youth. Grounded in social impact theory, this model explores the dynamics that may influence opioid use following school closures. By combining opinion dynamics and acute withdrawal intensity, the model simulates youth decision-making regarding opioids use. It suggests that lifting school closures could significantly increase non-medical prescription opioid use among youth. Effective interventions targeting risk factors at home can help prevent increased youth opioid use after school closures.
The second model evaluates the effectiveness of prescription regimes utilizing machine learning monitoring programs in identifying patients at risk of opioid abuse during treatment. It incorporates a hidden Markov model into an agent-based simulation to classify patients' underlying states of prescription opioid use. A synthetic data experiment was conducted using the calibrated agent-based simulation model to generate time series data for feature selection. Lowering prescription doses yields favorable results in terms of overdose rates, escalation to street opioids, and prescription legitimacy, emphasizing the need for comprehensive evaluation of public health interventions.
The third model focuses on modified opioid agonist therapy (OAT) guidelines during the COVID-19 pandemic. It simulates individuals receiving OAT, including those with increased take-home doses. The model assesses the impact of increased take-home doses on treatment retention and opioid-related harms. Model findings suggest that increasing take-home doses could enhance treatment retention. However, the increased opioid-related harms among certain groups of patients receiving higher take-home doses of OAT underscores the importance of expanding naloxone availability within the networks of OAT patients.
At a methodological level, this dissertation demonstrates the integration of opinion dynamics theories, AI-based health policies, and hierarchical state-charts to enhance the utility of agent-based models in addressing public health issues. It highlights the models' ability to generate time series data for machine learning techniques and evaluate the long-term impacts of AI-based healthcare policies. Furthermore, the modular design patterns used in the models facilitate comprehensive policy assessment while retaining generality
Environmental Assessment as a Tool for Managing Impacts on Wetlands: Understanding Current Practice in the Mining Sector
No full textWetlands are ecologically rich lands but also heavily impacted. Canada has a large mining sector, with operations impacting the important functions provided by wetlands that benefit humans. Environmental assessment (EA) is the primary regulatory tool for mitigating the impacts of development, including mining, to wetlands. Many jurisdictions in Canada use a hierarchical approach to mitigate wetland loss through avoidance, minimization, restoration. Any remaining loss is offset through compensation as under current federal and provincial policies or protections, development activities should pose “no net loss” of wetland functions. Although the mining industry is an important natural resource sector in Canada, there is limited research on how the potential impacts of mining activity on wetlands are identified and managed through EA processes. In response, this research examined wetland impacts and mitigations in EA. Case studies of mining projects in British Columbia (BC) and Yukon (YT) were examined, as mining is particularly important to the economies of this province and territory, and often occurs in areas of high wetland density. The methodology consisted of an in-depth document analysis of mining project EAs. The results indicated that, in BC, the EA practice tends to default to wetland area as a proxy for wetland function and is the primary measure for assessing impacts to wetlands. There is strong focus on direct impacts, while insufficiently describing baseline wetland functions potentially impacted and to be mitigated. Hydrological and habitat wetland functions were prioritized when described in mitigation measures. In YT, the reviewed EAs contain no information on the impacted wetland area, wetland class, or wetland functions, nor provide information on how the proposed mitigation measures would address potentially impacted wetland functions. The often-poor linkages between proposed wetland mitigation measures and identified project impacts found in this research were attributed to inadequate wetland policies and regulations for mitigating impacts, and poor EA practices to address and mitigate wetland impacts effectively. An exploration of mitigation practices across jurisdictions exposes inconsistencies within the implementation of the mitigation hierarchy, with a focus on minimization in BC and restoration in YT. Compensations approaches, only identified in BC, were creation, enhancement, and off-site restoration. While wetland loss in YT is inconclusive due to information gaps, the EA practice in BC suggests that the mitigation hierarchy is not fully applied, and the province is therefore likely moving toward a net wetland loss. Understanding and addressing the issues highlighted by this thesis will be important to advancing the effectiveness of EA to manage the impacts of mining activities on wetlands