title: Arctic Char Otolith Records of Recent Limnological Change in High Arctic Lakes

contributor:
Lamoureux, Scott F.
Geography and Planning

subject:
Limnology
High Arctic
Otolith
Geochemistry
Climate Change
Arctic Char

abstract:
Arctic lakes have been undergoing significant physical and chemical changes in recent years due to climate warming and permafrost thaw. These changes have the potential to impact organisms residing in these environments such as Arctic Char (Salvelinus alpinus) which represent the top predatory fish in Arctic lakes. Otoliths, the inner ear bones of fish, offer a method to monitor these impacts through chemical analysis of their annual rings. However, not only are long-term limnological records in the Arctic limited, but the impacts of climate-driven change on Arctic aquatic ecosystems are not well known. This research investigates a long-term record (2003-16) of the physiochemical properties of two High Arctic lakes at the Cape Bounty Arctic Watershed Observatory on Melville Island, Nunavut. Additionally, 2013 and 2015 otoliths were analyzed to investigate elemental changes associated with limnological and catchment change.

Results indicate that both lakes underwent significant chemical change following a catchment permafrost disturbance episode in 2007 that caused widespread slope disturbances and a deep seasonal active layer thaw. Both lakes have seen increased solute loads, most notably a 500% and 300% increase in water column SO42- in the West and East Lakes, respectively. Ionic ratios indicate that the source for the SO42- is compositionally similar to disturbed catchment streams. In addition, the West Lake has seen substantial and sustained increases in turbidity associated with internal subaqueous slumps and similar effects are absent from the East Lake. Hence, the synchronous change in solute loading to the lakes reflects increased contributions from the catchment due to deep active layer development.

Otolith analysis reveals an abrupt increase in Mg and a decrease in Ba in fish from both lakes.  Results further show that not only is the otolith chemistry statistically different within each individual fish from beginning to end of life, but also between the two lakes. These chemical changes are thought to reflect differential responses to multiple environmental stressors including the chemical and physical changes in the lakes. Collectively, these studies demonstrate the rapid threshold responses of Arctic lakes and highlights the fact that these physiochemical changes have implications for the whole aquatic ecosystem.

abstract: M.Sc.


title: A Numerical Investigation of Stress Path and Rock Mass Damage in Open Pits

contributor: Geological Sciences and Geological Engineering

rights: Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada

rights: ProQuest PhD and Master's Theses International Dissemination Agreement

rights: Intellectual Property Guidelines at Queen's University

rights: This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.

subject:
Rock Mass Strength
Rock Mass Damage
Synthetic Rock Mass
Open Pit Design

abstract:
The importance of establishing reliable slope designs becomes critical as the depth of open pits increases. Defining an optimum slope design that maximizes financial return and ore recovery without compromising safety conditions requires a proper evaluation of the stability conditions around the pit, and of the effects of instability on mining operations. Performing this analysis requires a good understanding of the behavior and strength of the rock mass at the slope scale.
The use of simplified constitutive models, which overlook the effects of damage accumulation on the mechanical behavior of rock masses, adds to the degree of uncertainty of the results of stability analyses of large rock slopes.
In this research, the relationship between damage and stress path is examined by using advanced numerical methods that allow the explicit representation of rock damage. The bonded particle method (BPM) has been used to evaluate the influence of stress path on damage accumulation, and on the strength of intact rock. The analysis of the influence of stress path on damage and strength at rock mass scale has been performed using the synthetic rock mass (SRM).
From this analysis, it was possible to correlate the extension strain with the onset of yielding in the SRM sample. This limit was found to be independent of the confinement stress and the stress path followed to load the sample. A series of 3D numerical models were created to explore the correlation between in situ stress, stress path and rock mass damage. The relationship between the onset of yielding and extension strain from SRM modelling was used to define the areas in the pit models that might suffer relaxation induced damage. The extent of the zone where damage can develop has a direct relationship with the magnitude of the in situ horizontal stress. The geometry of the pit has an influence on the distribution of extensional strain around the pit, as the the increased confinement generated by slope curvature reduces the extent of the damage zone in the curved areas of the pit.

abstract: M.A.Sc.


title: Modification of Nucleotide Excision Repair Activity by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and Sulforaphane

contributor:
Massey, Thomas E.
Biomedical and Molecular Sciences

subject:
Nucleotide Excision Repair
Sulforaphane
NNK
nrf2

abstract:
The studies described in this thesis investigated the relationship between the DNA repair pathway nucleotide excision repair (NER, which is critical for protecting against carcinogenesis), and two exogenous chemicals, the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and the nutraceutical sulforaphane.
	NER activity in female A/J mouse liver nuclear extracts decreased by 46% 12 h post NNK treatment and increased by 48% 24 h post NNK. These changes in NER activity were not attributed to alterations in levels of the NER proteins XPC, XPA, XPB and p53.  However, the binding of hepatic XPA and XPB to damaged DNA at both timepoints was increased, while the binding of XPC to damaged DNA was unchanged at 12 h and decreased at 24 h.
	A 63% decrease in NER activity in female A/J mouse lung nuclear protein extracts 24 h post NNK treatment was not attributed to changes in levels of XPC, XPA, XPB or p53.  However, the binding of lung XPA and XPB to damaged DNA was decreased and the binding of XPC to damaged DNA was increased at 24 h.   Hence, NNK-induced NER changes are time and organ dependent and are associated with changes in the binding activities, but not the levels, of specific recognition and early excision NER proteins.
	 A dose (100 mg/kg) and timepoint (6 h) of maximal effect of sulforaphane on female CD-1 mouse hepatic and pulmonary mRNA levels of two genes regulated by Nrf2, a major signalling pathway of sulforaphane mediated-effects, were found.  A 50% increase in NER activity was observed in liver nuclear extracts 12 h post sulforaphane treatment, while lung NER at 12 h and liver NER at 6 h were not affected by sulforaphane.  The increase in hepatic NER activity at 12 h was not associated with changes in levels of XPC, XPA, XPB or p53 or in the binding of hepatic XPC, XPA and XPB to damaged DNA.  These results suggest that the impact of sulforaphane on repair-associated processes is time and organ dependent and is not associated with changes in the levels or activities of these specific recognition and early excision NER proteins.

abstract: PhD


title: Multiple Receiver Wireless Power Charger for Mobile Electronic Devices in Near Field

contributor:
Jain, Praveen K.
Electrical and Computer Engineering

subject:
Wireless Power
Electronic Devices

abstract:
Portable consumer electronics like mobile phones, laptops, tablets and other devices have flooded the markets these days. While providing the convenience of keeping in touch with friends and family at the touch of a button, or performing complex scientific computations of a physical system, these devices have become an essential part of everyone’s day-to-day lives. In order to keep them up and running at all times, they need electrical energy, which in most cases is stored in the batteries of these devices. These batteries have limited storage capacity and lifetime. For these reasons, portable device users have to carry wired chargers all the time which can be an inconvenience and limits accessibility. Hence, there is a need for an alternative method of charging these devices.
Wireless power transfer provides a viable solution to the challenges encountered by portable device consumers when using the traditional method of charging batteries.
This thesis presents a multiple receiver wireless power transfer system for charging mobile phone batteries. The circuit consists of a transmitter and two receiver systems. A mathematical analysis of the circuit is carried out and simulated to understand its behavior with variation in coupling coefficient and load.  In order to charge the mobile phones without an extra communication module over a wide range of coupling coefficients, a variable frequency control algorithm is used. The transmitter circuit uses the algorithm to track the maximum input power of the system. The output voltage of the receiver circuit is controlled to meet the power requirement of the load as coupling coefficient varies by using a switch capacitor modeled as two back to back connected MOSFETs with their drain-to-source capacitance.
The proposed converter circuit topology is simulated and the results are presented. The circuit operates over a wide range of coupling coefficient, with good voltage regulation. Zero voltage switching (ZVS) is achieved at the inverter switches and the power requirement of the mobile phones are met without use of an extra communication module. The resonance frequency of the circuit is 5.7MHZ and it is design to deliver 10W (5V, 2A) each to two mobile phones.

abstract: M.A.Sc.


title: Advances in the synthesis of indazoles: regioselective C-7 functionalization by directed ortho metalation and progress towards indazole based azaborine compounds

contributor:
Snieckus, Victor A.
Chemistry

subject:
indazole
directed ortho metalation
azaborine

abstract:
As one of the fundamental heterocyclic building blocks, indazole and its derivatives have spurred significant research interest and patented applications. In particular, C-7 substituted indazole derivatives are of prime interest due to their significant bioactivities. Azaborine molecules incorporating the B-N structural motif are also of prime interest to chemists and material scientists stemming from their distinctive photophysical properties. The aim of this thesis is to construct new azaborine targets incorporating the indazole framework using Directed ortho Metalation (DoM) reactions as a key step, as well as devise new methods for C-7 functionalization of indazole heterocycles using DoM reactions.

Successful N-1 functionalization of indazoles enabled the subsequent Suzuki-Miyaura or Sonogashira cross coupling reactions to prepare C-3 substituted indazoles. Efforts in Directed ortho Metalation (DoM) reactions at the C-3 aryl groups of substituted indazoles towards azaborine targets were unsuccessful. Internal alkyne bearing substituted indazole was subjected to hydroboration conditions but without any conversion to the desired products. C-3 protected Indazoles bearing N- Directed Metalation Groups (DMGs) enabled their C-7 functionalization using DoM chemistry, and thereby led to the development of a new general route to these derivatives.

abstract: M.Sc.


title: Exploring Interactions with Shape-Changing Interfaces

contributor:
Vertegaal, Roel
Computing

subject:
Shape-Changing Interfaces
Organic User Interfaces
Flexible Displays
Input Devices
Rapid Prototyping
User-Centered Design

abstract:
Shape-Changing Interfaces foresee a future where interactive computing devices will be able to take on shapes that are flexible and robotically actuated, imbued with user interfaces that adjust to physical shape changes of the device hardware. In the past, shape change has been under-utilized as an interaction modality because the shape of electronic devices was always fixed by their rigid electronic components. As advances in flexible electronics and advanced materials pave the way for a new generation of non-planar, deformable, and actuated computer components, it has become possible to consider the effect on interaction design of shape transformation in electronic devices.

In this thesis, we present a number of shape-changing interfaces that move on a spectrum from rigid multi-faceted display surfaces that can be placed in different shape configurations by the user to fully actuated robotic notification systems. To understand how to better design shape-changing interfaces, we investigate flexible user interfaces that support physical manipulation as a means of user input. We report on an empirical study that shows that shape changes can be used for triggering viewport transformations in foldable display devices. We also discuss how thin-film displays can be seamlessly integrated with everyday objects. We then demonstrate how devices with flexible screen real estate afford focus + context functionality. Finally, we show that actuated shape notifications can be used to communicate notifications.

When designing shape-changing interfaces, we argue that designers should focus on blending the dynamic qualities of the digital world with the tactile qualities of the physical one, to create interfaces that have the ability to adapt their shape to accommodate for different usages, purposes, and contexts.

abstract: PhD


title: Theory and Modelling of Light-Matter Interactions in Photonic Crystal Cavity Systems Coupled to Quantum Dot Ensembles

contributor: Physics, Engineering Physics and Astronomy

subject:
nanophotonics
photonic crystal cavities
FDTD plugin tool
Semiconductor lasers
quantum dot lasers

abstract:
Photonic crystal microcavity quantum dot lasers show promise as high quality-factor, low
threshold lasers, that can be integrated on-chip, with tunable room temperature opera-
tions. However, such semiconductor microcavity lasers are notoriously difficult to model
in a self-consistent way and are primarily modelled by simplified rate equation approxima-
tions, typically fit to experimental data, which limits investigations of their optimization
and fundamental light-matter interaction processes. Moreover, simple cavity mode optical
theory and rate equations have recently been shown to fail in explaining lasing threshold
trends in triangular lattice photonic crystal cavities as a function of cavity size, and the
potential impact of fabrication disorder is not well understood. In this thesis, we develop
a simple but powerful numerical scheme for modelling the quantum dot active layer used
for lasing in these photonic crystal cavity structures, as an ensemble of randomly posi-
tioned artificial two-level atoms. Each two-level atom is defined by optical Bloch equations
solved by a quantum master equation that includes phenomenological pure dephasing and
an incoherent pump rate that effectively models a multi-level gain system. Light-matter in-
teractions of both passive and lasing structures are analyzed using simulation defined tools
and post-simulation Green function techniques. We implement an active layer ensemble
of up to 24,000 statistically unique quantum dots in photonic crystal cavity simulations,
using a self-consistent finite-difference time-domain method. This method has the distinct
advantage of capturing effects such as dipole-dipole coupling and radiative decay, without
the need for any phenomenological terms, since the time-domain solution self-consistently
captures these effects. Our analysis demonstrates a powerful ability to connect with recent
experimental trends, while remaining completely general in its set-up; for example, we do
not invoke common approximations such as the rotating-wave or slowly-varying envelope
approximations, and solve dynamics with zero a priori knowledge.

abstract: M.A.Sc.


title: Nursing Students' Knowledge and Attitudes Regarding Pain

contributor:
Van Den Kerkhof, Elizabeth
Nursing

subject: Nursing Students Pain Knowledge Attitudes

abstract:
Introduction and Purpose: Poorly managed or unmanaged pain is a problem that affects individuals, entire healthcare systems and societies throughout the world. Although national and international practice guidelines exist for the management of both acute and chronic pain, it remains problematic. Nurses are key contributors to interprofessional pain management teams, and are involved in both the assessment and management of pain. It is important to understand pain knowledge and attitudes amongst nursing students before they enter independent practice. The purpose of this study was to examine final year, pre-registration nursing students’ knowledge and attitudes about the assessment, treatment and management of pain.
Methods: Using a cross-sectional, descriptive design, 336 final year Bachelor of Science in Nursing (BScN) and Practical Nursing (PN) students were recruited through convenience sampling to complete the Knowledge and Attitudes Survey Regarding Pain (KASRP). The KASRP score is calculated by percentage score and 80% or higher is considered a passing score, which indicates adequate knowledge and attitudes towards pain.
Results: The mean KASRP score (SD) was 66.7% (9.1). English as participants’ primary language, attending School A, and having prior experience caring for someone in pain were independently associated with a statistically significant increase in mean KASRP scores (p<.05). Major areas of weakness in pain knowledge and attitudes were related to understanding populations at risk of respiratory depression after receiving an opioid, dosage calculations, medication administration and pharmacology. Strengths in knowledge and attitudes involved determining the best judge of an individual’s pain, the reliability of self-report of pain in children, and symptoms of withdrawal from opioid medications.
Conclusion: Further research is needed to understand the provincial and national levels of pain knowledge and attitudes of nursing students in other programs in Ontario and Canada. As well, as a follow up study to examine knowledge and attitudes once students have been in practice to determine if further learning occurs in clinical practice.

abstract: MNSc.


title: Practical Implementation of Transformative Learning in the Adult English as a Second Language Classroom

contributor:
Sharkawy, Azza
Education

subject:
ESL
Adult learning
Transformative Learning

abstract:
The purpose of this project is to design a resource informed by Transformative Learning
Theory for teachers of English as a Second Language (ESL), It provides a practical resource for
ESL instructors to use in their adult ESL classrooms. There is an abundance of resources for
ESL instructors that focuses on language, but limited resources for teachers interested in teaching
their ESL learners through the transformative learning lens. Learning another language,
especially in immersion programs, is a challenging experience for learners because of the
assimilation they experience into the new culture. Using insights from Transformative Learning
theory, educators can become more informed of what their learners may experience and what
they can offer to facilitate their learning experience. This resource will provide teachers with
some essential tools and knowledge to allow them to facilitate their students’ learning experience
by incorporating the transformative learning perspective in their teachings. Learning English as
a second language in Canada involves more than just the language component and this is what
the Transformative Learning Theory encompasses. Six lesson plans were designed for adult ESL
classes advanced level with objectives informed by the Transformative Learning Theory. There
are also additional practical resources that ESL instructors can use such as rubrics, an annotated
bibliography and mobile applications to facilitate Transformative Learning.

abstract: M.Ed.


title: Determination of Potentially Toxic and Essential Elements in Couscous From Arabic Countries Using ICP-MS and ICP-OES

contributor:
Beauchemin, Diane
Chemistry

subject: Food Risk Assessment

abstract: Couscous, which is made of semolina and flour, constitutes a primary food staple in many Arabic countries (such as Libya, Tunisia, Algeria, and Morocco), as well as the second most popular dish in France and other parts of the world. It is thus important to ensure its safety for consumption. This thesis looks at both potentially toxic (As, Se, Cd and Al) and essential elements (Cu, Zn, Fe, Mn, Mg, Mo, P, and S) in couscous, using an approach that can be used for realistic risk assessment. The analysis was carried out by inductively coupled plasma (ICP) optical emission spectrometry (OES) and mass spectrometry (MS), which were both used to assess the bio-accessibility of potentially toxic and essential elements in couscous.  An ICP-MS instrument equipped with a collision-reaction interface (CRI) was used to mitigate the impact of polyatomic interferences. Closed vessel digestion was performed for the determination of total concentrations. A conventional batch method, involving artificial saliva, gastric juice and intestinal fluid as extracting agents, was used to provide a good approximation of the bioaccessibility of potentially toxic and essential elements in couscous. The results revealed that the majority of elements were released by gastric juice and then saliva. In contrast, no detectable amount of elements was released by artificial intestinal juice. Both the total and bio-accessible concentrations of elements, which are all at levels making couscous safe for consumption, vary greatly, likely depending on geographic location and perhaps on the several food processing steps.

abstract: M.Sc.


title: Dispossession of Matrimonial Choice in Contemporary India: Examining the Link between Cross-region Marriages, Neoliberal Capitalism, and New Forms of Gender Subordination

contributor:
Bakan, Abigail
Cultural Studies

subject:
India
Marriage Migration
cross-region marriage
trafficking
neoliberal capitalism
inter-caste marriage
Dalit women
caste discrimination

abstract:
In India, in the mid 1990s, a new form of non-customary marriage emerged on the rural North Indian marriage-scape. Transgressing rules of caste endogamy and marriage within one’s religion, the men, largely drawn from the lower classes of Meo Muslims and the dominant-peasant Hindu castes, travelled long distances across India to seek wives from lower castes, other ethnicities, and/or different religions. This dissertation examines the status of these “cross-region” brides in their conjugal homes. It argues that the spread of the neoliberal market economy in India has led to the hyper-commodification of the female body; intensified gender subordination; eroded women’s bargaining ability around their labour and their bodies; and increased women’s vulnerability to new forms of gender-based violence. The neoliberal accumulative process in India has accentuated the socio-economic inequalities of historically marginalized groups like the Dalits and the Muslims, with the women from these groups being dispossessed differentially due to their gender. This makes them vulnerable to cross-region marriage proposals.

The dissertation draws on a four-year-long field-based inquiry conducted in 246 villages, from the four conjugal and natal regions of Haryana, Rajasthan, Odisha, and West Bengal, to interrogate hegemonic knowledge formations about these brides and their marriages. It analyses how the transgressions of caste, religion, and ethnicity shape the everyday lived experience of the Dalit and Muslim brides. Findings show that, while their bodies are desired for their free productive and reproductive labour, these women are treated as “internal others” by their conjugal families and communities due to their undesired ethnicity, caste, and/or religion. Their othered status in combination with the dispossession of matrimonial choice exposes them to caste discrimination, forcible cultural assimilation, and ethnoracist and religious prejudice within the intimacy of their marriages, and within their conjugal households and villages. This research illustrates that the cross-region brides occupy a contradictory space, as these marriages foreclose their agency, yet provide them the space to challenge established patriarchal norms and power structures through hidden transcripts of everyday acts of resistance.

abstract: PhD


title: An Investigation Into the Activated Carbon-Catalyzed Arsenic Oxidation Process

contributor:
Ghahreman, Ahmad
Mining Engineering

subject:
Arsenic
Activated Carbon
Oxidation
Catalyst

abstract:
Arsenic is a highly toxic element that is becoming an increasingly more prevalent issue for mining and metallurgical operations. Arsenic is an abundant element in the earth’s crust and is commonly associated with metals such as gold, silver, copper, nickel and many others. Arsenic is often oxidized prior to its removal from process streams because the higher oxidation state of arsenic typically offers a more stable solid product. A novel and robust process to oxidize arsenic is activated carbon-catalyzed arsenic oxidation which is a process which uses oxygen, as the only consumable reagent, and activated carbon.
The arsenic oxidation mechanism was explored via cyclic voltammetry, zeta potential measurements, X-ray photoelectric spectroscopy, shake tests, batch tests and continuous column tests. It was determined that hydrogen peroxide is formed on the surface of activated carbon and this aids in the oxidation of arsenic. Adsorption of arsenic species on the activated carbon was a large factor in the investigation. Two mechanisms of arsenic oxidation were theorized and it is believed that they occur simultaneously. The first hypothesized reaction pathway is that As (III) is oxidized when it contacts hydrogen peroxide on the activated carbon surface and is then instantly adsorbed as an As (V) compound. The second hypothesized reaction pathway is that As (III) adsorbs onto the surface of activated carbon and is then oxidized by hydrogen peroxide present in close proximity in the solution to the activated carbon surface. Activated alumina was used instead of carbon during a batch test experiment in order to verify that it is the functional groups of carbon that perform the catalytic ability of activated carbon to oxidize arsenic and not the porous nature of its surface. It was concluded that activated alumina had no ability to oxidize arsenic and therefore it is the functional groups on the carbon surface that provide the oxidative capabilities.

abstract: M.A.Sc.


title: Statistical Methods For Biomarker Threshold Models in Clinical Trials

contributor:
Jiang, Wenyu
Mathematics and Statistics

subject:
Biomarker
Statistical methods
Threshold
clinical trials

abstract:
In clinical trials, the main objective is to investigate the treatment effects on patients. However, many molecularly targeted drugs or treatments tend to benefit a subset of patients more, identified by a certain biomarker. The cut-point value defining patient subsets is often unknown. For this situation, the ordinary likelihood ratio test cannot be applied for testing treatment-biomarker interaction because of the model irregularities.

We develop a residual bootstrap method to approximate the distribution of a proposed test statistic to test for treatment-biomarker interaction in survival data. Simulation studies show that the residual bootstrap test works well. The proposed method is applied to BIG 1-98 randomized clinical trial of breast cancer with Ki-67 as biomarker to consider the treatment effects on patients in two subsets. We also extend the residual bootstrap method to clustered survival data with an application to data from the I-SPY 1 clinical trial with the estrogen receptor total score as a biomarker.

Another research topic of the thesis is deriving the asymptotic distribution of a penalized likelihood ratio test statistic for testing biomarker effect and treatment-biomarker interaction in binary data. The model can be viewed as a mixture of logistic regression models with unknown cut-point for which the regularity conditions of ordinary likelihood methods are not satisfied. We first approximate the indicator function defining biomarker subgroups by a smooth continuous function. To overcome irregularities, we develop a penalized likelihood method, introducing a new idea of using random penalty term. Proposing a new set of regularity conditions helps us to study the properties and limiting distributions of the maximum penalized likelihood estimates of the parameters. We further prove that the penalized likelihood ratio test statistic has an asymptotic $\chi^{2}_{3}$ distribution under the null hypothesis. Extensive simulation studies show that the proposed test procedure works well for hypothesis testing. The proposed method is applied to a clinical trial of prostate cancer with the serum pro-static acid phosphatase (AP) as a biomarker.

abstract: PhD


title: Scaffolding Multidimensional Understanding and Rule Use in Preschoolers' DCCS Performance

contributor:
Sabbagh, Mark A.
Psychology

subject:
executive functioning
dimensional change card sort
shifting
re-description

abstract:
The goal of this dissertation was to examine how specific scaffolding strategies could affect executive functioning (EF) performance in preschool aged children, specifically shifting performance as measured by the Dimension Change Card Sort task (DCCS; Zelazo, 2006). In the DCCS, children must sort test cards initially based on one dimension (e.g., shape) and then switch to sort by another dimension (i.e., colour). When asked to switch rules, 3-year-olds tend to perseverate whereas 5-year-olds can shift successfully. Theoretical accounts center on the notion that children have difficulty successfully representing rules that have embedded if-if-then conditional (Bunge & Zelazo, 2006). If this is true, interventions that are designed to make representing the embedded conditional rule less taxing should lead to better performance on post-switch trials of the DCCS. Given that preschool aged children struggle to describe objects in new ways on the basis of different dimensions (Kloo & Perner, 2005), children may perseverate because they have difficulty reconceptualising the stimuli to match with the post-switch sorting parameters. The studies in this dissertation sought to test the hypothesis that DCCS performance could be scaffolded by promoting children’s attention to the multidimensional nature of objects.
In Study 1 and 2, brief experimental games were used to scaffold 3-year-old children’s ability to think about the multidimensional nature of objects by both separating and aggregating dimensions. Results showed that promoting multidimensional understanding facilitated DCCS performance relative to controls. Moreover, it seems that this is the case regardless of the nature of the scaffolding dimensions.
In Study 3, we included an additional extra-dimensional sorting parameter, order, in an attempt to facilitate performance on a more advanced version of the DCCS in 5-year-olds. Again, children in the experimental condition performed significantly better relative to controls, suggesting that difficulty conceptualizing objects in different ways may be a critical component of shifting performance across the preschool age range.
The findings will be discussed with regard to their theoretical implications concerning the nature of EF development more broadly, and shifting more specifically, and their potential to inform research with children who may be at risk for difficulties with shifting.

abstract: PhD


title: A Capstone Professional Learning Project: an Ensemble Approach to Professional Learning

contributor:
Klinger, Don A.
Education

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Professional Learning
Professional Development
Technocratic Learning
Practitioner Learning
Ensemble Theatre
Ensemble learning

abstract:
This study focused on understanding the nature of a professional learning experience facilitated through the theory and practices of ensemble theatre-making. The study was guided by two questions: How do K-12 teachers characterize their current school-based professional learning? And, how do a group of teachers experience an ensemble approach to professional learning?
To answer the first question, a professional learning survey was created and distributed to teachers at a variety of American international schools. The purpose of the survey was to gain insight as to how K-12 teachers characterized their current school-based professional learning. The second question was explored through a professional learning intervention. Over an 18-week period, five middle school teachers participated in professional learning experience guided by the theory and practices of ensemble theatre-making.
Descriptive statistics and narrative were used to explain the findings from the survey.  Narrative was used to highlight the importance of context in teacher professional learning. Findings from the survey suggested that schools and teachers have different perceptions as to what constitutes meaningful professional learning, and that teachers see a direct correlation between the documentation/accounting of professional learning and professional advancement.
A phenomenological perspective was taken when analyzing the 18-week professional learning intervention. Findings from the ensemble intervention suggested that the nature of learning in ensemble derives from a personal pre-disposition/readiness to learn, and the behaviours of releasing, expressing, and supporting. Further findings suggested that the subjective nature of ensemble-learning provided participants with an authentic learning experience.
Key contributions of the research include: (a) language that allows teachers and administrators to describe the nature of accountability and capacity building in either self-directed or institutionally-mandated professional learning initiatives, (b) a framework for a non-technocratic approach to professional learning that acknowledges the complex nature of teaching, and through multiple processes facilitates an understanding of that complexity, and (c) a model that articulates an emergent understanding of the actions and interactions present within the phenomenon of ensemble-learning.

abstract: PhD


title: A Systematic Observation of Coach Leadership Behaviours in Youth Sport

contributor:
Côté, Jean
Kinesiology and Health Studies

subject:
Coaching
Leadership
Youth Sport

abstract:
There is growing recognition for the Transformational Leadership (TFL) framework in youth sport. Indeed, theoretical and empirical evidence suggests that coach TFL plays a salient role in promoting developmental outcomes in youth athletes. Nevertheless, research examining the influence of coach leadership behaviours typically relies on self-report measures and inductive analytical techniques, thus providing a limited picture of TFL. It is therefore important to generate baseline descriptive data, revealing the extent to which leadership behaviours are currently being employed by youth sport coaches. Accordingly, the overarching purpose of this study was to provide quantitative descriptions relating to the nature and extent to which youth sport coaches display leadership behaviours across playing contexts (i.e., training and competition).
Participants were seven head coaches of youth soccer teams and 73 athletes (Mage = 14.26, SD = 1.27, 40 female). Systematic observation was employed to examine the frequency of coach leadership behaviours. Descriptive data regarding the coaches’ use of leadership revealed that coaches spend more time exhibiting neutral behaviours compared to active leadership (e.g., TFL). This was consistent across training (75.2% neutral) and competition (77.5% neutral). When coaches actively displayed leadership, they frequently displayed TFL behaviours, including individualized consideration (M = 9.29%), inspirational motivation (M = 6.68%), and less frequently, intellectual stimulation (M = 2.95%), and idealized influence (M = 1.5%). Additionally, coaches rarely displayed passive and ineffective leadership. Finally, the results indicate that coaches display similar levels of leadership in both training and completion. These findings provide insight into the leadership behaviours employed by coaches across playing contexts, which can inform future leadership workshops focused on promoting athlete development. These findings hold practical implications, and lend insight into the youth sport coaching and TFL literature.

abstract: M.Sc.


title: Functional  Genomics Indicates a Minor Role for the Purple Acid Phosphatase Isozyme AtPAP17 in Arabidopsis Thaliana Phosphorus Metabolism

contributor:
Plaxton, William C.
Biology

subject:
Purple Acid Phosphatase
Leaf Senescence
Arabidopsis Thaliana
Functional Genomics
Phosphate Nutrition

abstract: Phosphorus (P) is a crucial plant macronutrient, as it is a constituent of essential biomolecules involved in nearly all major metabolic processes. However, soluble orthophosphate (Pi), the only form of P that roots directly assimilate, is often limiting in most soils. This has prompted the widespread use of unsustainable and polluting Pi-containing fertilizers in agriculture. Plants have evolved a complex variety of biochemical adaptations that facilitate Pi acquisition, utilization, and recycling during nutritional Pi-deficiency. This includes the up-regulation of vacuolar and secreted purple acid phosphatases (PAPs) which catalyze Pi hydrolysis from Pi-monoesters at acidic pH. Of the 29 predicted PAP isozymes encoded by the genome of the model plant Arabidopsis thaliana, several high molecular weight isozymes, particularly AtPAP26, have been shown to play a key role in scavenging and recycling Pi during nutritional Pi-deprivation or leaf senescence. It has been hypothesized that AtPAP17, a low molecular weight PAP isozyme, also has a crucial function in Arabidopsis Pi metabolism as its transcripts show a marked induction during Pi-starvation or leaf senescence. This thesis uses a reverse genetic approach to examine AtPAP17’s function in Arabidopsis Pi acquisition and use efficiency by taking advantage of the publicly available T-DNA tagged insertional mutagenized populations of Arabidopsis. An anti-AtPAP17 peptide antibody was also raised in rabbits for detecting 35 kDa AtPAP17 polypeptides on immunoblots of Arabidopsis extracts. A null atpap17 allele was identified and characterized that abrogated AtPAP17 expression at both the transcript and protein level. However, loss of AtPAP17 expression did not influence the progression of Arabidopsis leaf senescence nor plant growth during Pi-deprivation relative to wild type (Col-0) controls. A sizable (~40%) decrease in extractable APase activity was only observed when the atpap17-2 mutant was subjected to Pi-deprivation. These results suggest that, contrary to inferences drawn from transcript profiling, AtPAP17 does not play a direct role in Pi scavenging during leaf senescence, and only plays a minor role during Pi-starvation.  As AtPAP17 also exhibits alkaline peroxidase activity, future studies are needed to establish its potential involvement in reactive oxygen species metabolism during Pi stress or leaf senescence.

abstract: M.Sc.


title: Role of microbial community dynamics and the extracellular matrix in formation and instability of microbial structures in biological wastewater treatment systems

contributor:
Liss, Steven N.
Chemical Engineering

subject:
Biofilm sloughing
Aerobic granule formation
Aerobic granules instability
Flocs
Mixed microbial community
16S rRNA genes
Extracellular matrix
Integrated fixed-film activated sludge
Sequencing batch reactor
Relative hydrophobicity
Biological wastewater treatment
Amyloid adhesin
Flagella

abstract:
The structural, physiochemical, and microbial properties of biofilms, flocs, and granules during the formation and instability of these microbial structures were studied. Specifically, the composition of extracellular polymeric substances (EPS) and microbial community dynamics were observed during: (a) formation of granules by modifying the operational conditions for rapid granulation in an integrated fixed-film – sequencing batch reactor (IF - SBR) system, (b) aerobic granule development with transient filamentous bulking, and (c) biofilm sloughing in an IFAS system. The thesis arose from the observations of the dynamic nature in which these structures developed and changed while operating IF - SBR. Biomass from IF - SBR could be differentiated into more and less hydrophobic fractions and the physicochemical properties and changes in EPS were associated with periodic sloughing of the biofilm from IF - SBR carriers. It was found that sloughing did not lead to biomass loss from the bioreactors and the resulting suspended biomass and flocs that had enhanced settleability.
Coupling granulation technology with an IFAS system was an interesting development that improved the capacity and efficiency of wastewater treatment. Rapid granulation was observed with oxic/anoxic/oxic conditions in the IF - SBR system where Rhodocyclaceae and Comamonadaceae populations (known for denitrification) were predominant.
During granulation, a microbial community was selected with a predominant bacterial group, which produced a protein rich extracellular matrix for formation of compact granules. The lysis of dominant microbial population in aerobic granules resulted in transient granule instability; however, the microbial community was capable of self-remedy to restore the granular structure after an instability phase.
In the IFAS system, microcolonies with a higher polysaccharide content and dead cells resulted in biofilm sloughing. It was observed during the study that apparently distinct microbial structures (biofilms, flocs and granules) are pleomorphic microbial aggregates. The Identification of hydrophobic characteristics of bacteria and the extracellular adhesins expressed by the bacteria have a potential to improve our understanding about microbial interaction. The understanding about the microanatomy of biofilms, flocs and granules will facilitate to engineer stable microbial structures.

abstract: PhD


title: Chemical Sensing Using The Life, Death, And Rebirth Of A Photon

contributor:
Loock, Hans-Peter
Chemistry

subject:
Fluorescence
Excitation Emission Matrix Spectroscopy
Fibre Optics
Hadamard
Modulation
Cavity Ring-Down
Photonic Crystal Fibre
Refractive index
Sensor
Degradation Kinetics
Interferometer
Liquid Scintillator
Lubrication Oil

abstract:
In this thesis, optical sensing platforms using the “life, death and rebirth” of a photon are utilised to quantify and characterise chemicals in various samples. In this analogy, the “life” of a photon is characterised by its interactions with the propagation media, since they alter its speed and direction through the refractive index. The “death” of the photon can be observed by its absorption into an analyte, and after this process the “rebirth” of the photon can exist in the form of fluorescence. The instruments described here are based on fundamental optical techniques that were adapted for use with optical waveguides, thus allowing for compact inexpensive instrumentation that is able to characterise samples on-line and within small volumes. Characterising liquids in small volumes reduces both cost and waste, possibly increasing a company’s potential profit.

This thesis presents a hollow core in-fibre photonic crystal fibre interferometer used to measure the refractive index and polarisability of gas in small volumes down to 1.2 μL. Similarly, a new amplified fibre loop cavity ring-down spectrometer is used to measure liquid alkynes through an overtone absorption band to a detection limit of 19% v/v in volumes of about 1 pL. Another instrument was built based on the well-known fluorescence excitation emission matrix (EEM) spectroscopy method. Fluorescence EEM is shown here to have great versatility in monitoring the kinetics involved in the degradation of complex fluorescent samples such as lubrication oil and liquid scintillators. When EEM spectroscopy is combined with multivariate analysis techniques, including parallel factor analysis, the full advantages of the technique are realised as all the fluorescent chemical components can be measured quantitatively. However, as it takes a long time to acquire a single EEM spectrum using commercial instruments, this method was not capable of conducting real-time on-line measurements. In this thesis we therefore developed a Hadamard-transform EEM spectrometer, which through simultaneous modulation of all excitation wavelengths, was able to acquire full EEM spectra in a fraction of the time. This instrument realises the potential of using EEM spectroscopy in real time — a first step towards the goal of a commercial on-line sensor.

abstract: PhD


title: Synthesis and Characterization of Functional, Chiral Periodic Mesoporous Organosilica Materials

contributor:
Crudden, Cathleen M.
Chemistry

subject:
Periodic Mesoporous Organosilica
Self-Assembly
Chiral Materials
Circular Dichroism
Hybrid Silicas
Heterogeneous Catalysis
Solid-State
Sol-Gel

abstract: High-surface-area materials are ideal for recyclable supports and solid phases for heterogeneous catalysis and for chromatography because they allow for a large number of substrate-surface interactions. Such synthetic materials can be precisely tuned in terms of pore size and shape, particle shape, hydrophobicity, and functionality at the surface. Periodic mesoporous organosilica (PMO) materials offer the stability of a silicon framework; the functionality of an organic compound, ligand or complex; and the opportunity for all of the aforementioned properties to be highly controlled. Additionally, these materials can have chirality on the molecular or particle scale, through the use of chiral building blocks during their synthesis. In the work described herein, we have shown that molecular chirality can be installed within PMO materials through the use of chiral organic monomers doped into the material bulk phase. The chiral dopants and other functional dopants can be chemically manipulated within the solid-state material, and we have shown that the deprotection of masked biphenol groups yields free diols that can be subsequently modified into new functionalities, such as phosphoric acid residues. By cleaving the chiral auxiliary of the chiral dopants within the solid-state material, we can remove the physical barrier to racemization; and yet, the dopant does not lose its chiral information, even after hydrothermal treatment. This work demonstrates the potential for multifunctional PMOs as heterogeneous catalysts, where selective functionalization of embedded dopants can establish different types of active sites within the material. Lastly, the synthesis of new bulk phase monomers is investigated with the idea that the complimentary quadrupole polarities of perfluorinated and nonfluorinated arenes will facilitate the self-assembly of the bulk and dopant monomers by increasing electrostatic interactions during material synthesis.

abstract: PhD


title: Offline Single-Stage Electrolytic-Capacitor-Free Flicker-Free High Power LED Driver

contributor:
Liu, Yan-Fei
Electrical and Computer Engineering

subject:
Single-Stage
LED Driver
Flicker-Free
Offline
Electrolytic-Capacitor-Free

abstract:
The use of white LED bulbs has increased exponentially in recent years because of their low energy consumption, long life time, high luminous efficacy and environmental friendly features.
The illumination LED bulbs require a controlled constant amount of DC current to emit a constant light. Therefore, the LED power supplies (LED drivers) determine the lighting performance. Moreover, it impacts the sales price, daily expense as well as the lifespan of the lamp.
Conventional single-stage topologies for grid-connected LED drivers with high power factors (PFs) require large capacitances at the output to limit the low frequency (double line frequency, i.e. 120 Hz) LED current ripple that causes flicker. Electrolytic capacitors are commonly used to reduce this low frequency current ripple at the output. LED bulbs have a long lifespan (>50,000 hours), but the electrolytic capacitor has a short lifespan (5,000 hours). Therefore, using electrolytic capacitors will significantly reduce the lifespan of the entire LED lamp.
The basic bipolar ripple cancellation technology has been proposed, using a dc-ac inverter, to cancel the low-frequency ac ripple in the LED current and thus minimizing the output capacitance requirement, enabling the use of long-life film capacitors (>50,000 hours).
Furthermore, the improved bipolar ripple cancellation technology with a floating dc-ac power structure is proposed to accommodate the usage of low-voltage-rating dc-ac inverter in variable output voltage LED driver applications. The control scheme to achieve both ripple cancellation and the floating auxiliary capacitor voltage regulation is presented.
In the above two ripple cancellation technologies, the voltage sensing control method has been used. A new control method, called current sensing control method, is proposed and implemented to achieve ripple cancellation as well. The method keeps using the floating dc-ac power structure while provides a simple and low-cost control solution, compared to the voltage sensing method.
Finally, LLC resonant converter is used as the topology of single-stage high-power LED driver application to improve the efficiency. The design rule of LLC resonant converter working in Power-Factor-Correction mode is proposed and the performance is demonstrated.

abstract: PhD


title: Exploring the Use of Biomechanical Metrics in the Validation of Physical Employment Standards

contributor:
Fischer, Steven L.
Kinesiology and Health Studies

subject:
physical employment standard
ergonomics
biomechanics

abstract: Physical Employment Standards (PES) are applied to test candidates’ abilities as required to perform a job safely and efficiently.  Ability in this context refers to capacity (e.g., sufficient strength) and movement competency (e.g., technique). From the perspective of construct validity, physiological, psychophysical, and strength-based metrics are often applied as they reflect important constructs of capacity.  However, objective metrics related to movement competency seem to be lacking in the context of PES. Two types of PES-based tests are commonly applied to assess candidates’ abilities: task predictive tests (TPT), where candidate’s actions are designed to predict job performance, and task simulation tests (TST), where candidate’s actions are directly simulated from the actual job.  The current study explores if the use of movement-based metrics reveals meaningful information about the validity of a TPT relative to a TST. Participants were sixteen former manual materials handling employees. Participants performed a TPT and a TST, where each was designed based on the same underlying job description (box and container lifting tasks). Three-dimensional trunk and upper limb motion, and electromyography (EMG) of the back and shoulders were collected during each test. Joint angles and maximum voluntary isometric contractions were processed from raw motion and EMG data, respectively. Cross-correlation was applied to all data to assess the differences in the movement-based waveforms between the two types of tests. Kinematic and EMG outcomes were generally similar between the tests (R > 0.8) with two exceptions: Trunk flexion/extension angles were the least similar between TPT and TST during container tasks (R < 0.8) compared to other tasks, and EMG at the shoulders were the least similar during the heavier box tasks (R < 0.8) compared to other tasks. The TPT generally elicited similar movement-based patterns compared to the TST, demonstrating construct validity with respect to movement competency. However, the TST required participants to adopt different movement strategies, particularly when the use of actual containers changed the grip demands relative to the TPT. The TPT should consider handle characteristics if the test is being used to assess both capacity and competency with respect to actual job demands.

abstract: M.Sc.


title: Ellipse Fitting for Planar Hip Morphology and Kinematics

contributor:
Ellis, Randy E.
Computing

subject: hip ellipse morphology kinematics

abstract:
Although the human hip is commonly thought to be a ball-and-socket
joint, recent 3D studies suggest that the hip translates as well as
rotates. This is of interest not only for biomechanics but also
clinically, because hip translation may be important to physiotherapy
and to computer-assisted surgery for total hip replacement.  Previous
3D studies have evaluated hip kinematics as well as morphology by CT,
MRI and surgical intervention.  A minimally invasive, inexpensive, and
accurate way of measuring hip shape and motion may be useful in basic
science and clinical application.  This work used prototype software
to quantify planar hip morphology and kinematics from plain 2D
radiographs.

Ellipses were fit to the articular contours of the femoral head and
acetabulum of plain 2D radiographs of arthritic and dysplastic
patients.  The prototype software was validated in a study performed
by three board-certified orthopedic surgeons. It was found to be
efficient and reliable, taking less than one minute to quantify planar
hip morphology and having no statistical difference between the
observers.

The prototype software was used in a clinical study to quantify planar
hip kinematics.  Preoperative AP pelvic radiographs were taken of 11
THA patients in 4 different positions.  The semi-automated fits
detected a mean femoral head translation of 3.42mm, with no
discernible directional pattern.  Every one of these arthritic
patients exhibited substantial planar hip translation.

The findings are consistent with the hypothesis that hip morphology
and kinematics can be quantified from plain 2D radiographs.

abstract: M.Sc.


title: “Apocalypse at the Doll Counter”  Barbie, Marjie, and the North American Toy Industry, 1959-67

contributor:
Brison, Jeffrey
History

subject:
Cultural History
Business History
Barbie
Canada
United States
Economic Nationalism
Toy industry

abstract:
Positioned at the intersection of business, social, and cultural history, this thesis, “Apocalypse at the Doll Counter”: Barbie, Marjie, and the North American Toy Industry, 1959-67, uses a case study of the parallel and intersecting journeys of the American Barbie doll and Canadian Marjie doll to explore Canada’s cultural and economic relationship with the United States primarily in the late 1950s and into the 1960s. The histories of these dolls show how toys were imbued with nationalist and gendered sentiments and values in an era where American cultural and economic power penetrated Canada’s borders; Canadians responded to perceived cultural imperialism with a heightened sense of Canadian nationalism, reflected in wider Canada-US relations in the same period.

The thesis further explores the rise of the Barbie doll as it became an iconic piece of plastic that transcended the toy world and was attached with cultural meaning. The cultural meaning and popular image of the Barbie doll was created by the powerful marketing of the doll by Mattel, especially as the company created a wide selection of accessories and companion goods to be purchased alongside the doll. Through Barbie, Mattel revolutionized the toy industry, much to the chagrin of later generations of parents.

Finally, this thesis also use the Barbie/Marjie clash to provide a business history of the North American toy industry. Investigating how the Canadian toy industry approached economic competition with the American toy firms like Mattel, it looks at how the toy industry, more broadly, transitioned from a seasonal to a year-round industry and faced increasing competition at home with the development of American branch plants in Canada. Ultimately, this thesis shows how, despite all the efforts of the Canadian toy industry and the Canadian government, any success was short lived.

abstract: PhD


title: A Paleolimnological Assessment of Eutrophication Trends in the St. Lawrence River Area of Concern Over the Past 70 Years

contributor:
Cumming, Brian F.
Environmental Studies

subject:
St. Lawrence River
Eutrophication
Paleolimnology

abstract: Recent surface-water surveys suggest that high nutrient concentrations and nuisance algae remain an issue in the St. Lawrence River Area of Concern (AOC) at Cornwall, Ontario, particularly in the tributaries and nearshore zones of Lake St. Francis (LSF). Although extensive remedial actions have been completed in Cornwall and the surrounding area since its designation as an AOC, activities have primarily targeted the reduction of industrial and municipal pollution to the St. Lawrence River, with much less attention given to eutrophication. It remains unclear whether remedial actions first implemented in the 1990s have resulted in decreases to algal production and compositional changes to algal assemblages in the nearshore zones of LSF. This thesis employs a paleolimnological approach to provide a historical context for the present-day nutrient concentrations in LSF, as well as to determine whether actions associated with the Remedial Action Plan developed for the AOC have influenced algal community composition and concentrations. A sediment core was collected near the north shore of LSF and was examined for changes in the fossil diatom (Bacillariophyceae) assemblages, diatom concentrations, pigment concentrations, organic matter content, and ratios of stable isotopes (δ15N and δ13C). Diatom and pigment concentrations increased in the uppermost intervals of the core, suggesting that overall production has risen in the last few decades. Diatom assemblages were dominated by benthic taxa throughout the core. One significant change to the diatom relative abundances was observed, occurring at a depth corresponding to the late-1950s. Stable isotopes suggested a steady increase in agricultural activity since the mid- to late-20th century and a large input of terrestrial organic material to the aquatic ecosystem circa 1960. It is likely that intensive flooding resulting from the construction of the Moses-Saunders Power Dam upstream of Cornwall led to an influx of organic material from the catchment in the late-1950s, co-occurring with a diatom assemblage shift. The recent increase in algal production is likely attributable to increased nutrient concentrations resulting from intensive agricultural activity in the contributing watersheds. It is unlikely that delisting goals for eutrophication in the AOC will be reached without a drastic change in current practices.

abstract: M.E.S.


title: Spawning Black Bass and the Invasive Round Goby in Lake Ontario and the St. Lawrence River

contributor:
Tufts, Bruce L.
Biology

subject:
Smallmouth
Largemouth
Bass
Round Goby
Angling

abstract: This thesis examined the relationships between the invasive Round Goby (Neogobius melanostomus) and the economically important recreational fish species, Smallmouth Bass (Micropterus dolomieu) and Largemouth Bass (Micropterus salmoides). Nesting bass were located in Lake Ontario and the St. Lawrence River prior to the opening of the angling season in 2015. Predator density, offspring development, and predation intensity during simulated catch-and-release angling were measured to determine the risk of combined negative effects from recreational angling and nest predation by Round Gobies. General linear models were used to compared the influence of habitat, temperature and species on each variable. As previously demonstrated, Round Gobies preyed on Smallmouth Bass eggs and larvae when the guarding male was absent from the nest. Largemouth Bass nests were located in areas with very low Round Goby abundance and are likely not experiencing significant predation by Round Gobies. Smallmouth Bass nesting near Lake Ontario are at the highest risk for predation because of slower offspring development in colder water, and prevalent rocky/sandy nesting habitat with high Round Goby abundance. The closed fishing season in 2015 did not protect the majority of Smallmouth Bass from recreational angling over the vulnerable stage of offspring development. Smallmouth Bass recruitment might be limited in these areas from a combination of hyper abundant predators and recreational angling.

abstract: M.Sc.


title: “Affection wondrous sensible”:  Locating Affect in Shakespeare’s Comedies

contributor:
Straznicky, Marta
English Language and Literature

subject:
Affect theory
Shakespeare
Early Modern Drama
Trauma theory
Genre

abstract:
This dissertation reads three Shakespearean comedies, The Comedy of Errors, The Merchant of Venice, and Twelfth Night, through the mutually illuminating perspectives of early modern theories of the passions, mid-twentieth century genre theory, and twenty-first century affect studies. Its goal is to show how Shakespeare derives inspiration from the structure and character types provided by New Comedy, yet evades formulaic simplicity by suffusing the plays with emotionally intense, even traumatic, conflict. By adopting the critical framework of historical phenomenology, and close reading to pay detailed attention to the way that Shakespeare uses language to represent emotional states, this study evaluates how the distinctly early modern psychophysiological paradigm of the embodied passions shapes characters’ understanding of identity as an ecology of mutual influence with the bodies of others and the environment.

A major preoccupation of these plays is belonging. Testing Northrop Frye’s postulate that “In fiction, we discovered two main tendencies, a ‘comic’ tendency to integrate the hero with his society, and a tragic tendency to isolate him” (Natural Perspective 54), this study shows how social inclusion and exclusion in these plays are based on the individual’s willingness to understand the management of the passions as a social responsibility. The struggles that Shakespeare’s comic characters face stem from questions of how to know the self and how to integrate that knowledge with social structures that, much of the time, resist or reject the very notion of individual selfhood as we know it today. Sacrifice, self-loss, and self-denial are negative experiences that comic characters must survive through, whether they are ultimately happy or not. While these comedies depict characters navigating and negotiating powerful emotions, it becomes evident that these negotiations take place at a declining rate of success as Shakespeare’s career progresses. This dissertation concludes that Shakespeare’s comedies should not be read as oppositional to his tragedies, but as components of a single continuum that exposes the painful cost of maintaining social unity.

abstract: PhD


title: Paleolimnological Reconstruction of the Environmental Impact of the Deloro Industrial Site on Moira Lake (Ontario)

subject: Cladocerans MLA XANES Paleolimnology Deloro

abstract:
Historical industrial activity at Deloro (1866-1961) included both mineral exploration and mineral processing practices which produced over 650,000 m3 of waste material ultimately dumped on site. Previous studies on the Moira River system including examination of surface waters, sediments, and sediment porewaters identified Moira Lake as an affected lacustrine system. The contamination resulted in elevated levels of arsenic (As), cobalt (Co), and nickel (Ni) in the lake sediments. This study used paleolimnological techniques, including geochemical tools, to evaluate the impact of the metal contamination on the lake system.
The data collected showed increased concentrations of As, Co, and Ni with respective concentrations ranging from 50-900mg/kg, 21-1500mg/kg, and 41-1400mg/kg coinciding with the years of operation of Deloro determined via 210Pb dating. The bulk of the sedimentary As occurred as inorganic As(V) with higher As(III) in the deeper sediments and minor occurrences of As(-I) at shallow depths as indicated by XANES. The As was determined to be almost exclusively hosted in iron oxides (98-100%) via SEM-MLA. Under reducing conditions, As bound to iron-oxides may be released as dissolved As via reductive dissolution and diffusion through porewaters. The presence of As(-I) is a potential result of secondary re-precipitation of dissolved As.
Increased chlorophyll-a concentrations and a shift in the cladoceran assemblage from one dominated by pelagic Bosminids to one dominated by littoral Chydorids and pelagic Daphniids suggested a response to a regional stressor. The primary and secondary production suggested that, although changes coincided with the onset Deloro, there was another driving factor thought to be nutrient enrichment and/or climate change.

abstract: M.E.S.


title: The Use of Digital Image Correlation and Fiber Optic Sensing to Assess Railway Track Support Performance

contributor:
Take, W. Andy
Civil Engineering

subject:
Railway
Track Support
Digital Image Correlation
Fiber Optic Sensing
Track Voids
Dynamic
Track Displacement
Rail Seat Loads

abstract:
The low subgrade stiffness associated with railway corridors constructed over peat often results in large rail displacement and ground deformations during train passage, leading to accelerated track deterioration and increased risk of derailment. This thesis provides insights into track behaviour using Digital Image Correlation (DIC) and fiber optic sensing.

To measure track displacement using DIC at sites with soft subgrades a two-camera backsight method was developed to account for the movement of the camera due to ground vibrations. This method was then used to measure track displacement of the ballast crib before and after mass stabilization at a poorly performing section of track. The effectiveness of the mass stabilization was quantified using the trackbed modulus, which provides a method to isolate the improvement of the subgrade from the presence of voids between the rail, sleepers, and ballast. The results indicate that mass stabilization can be an effective rehabilitation strategy.

The use of Rayleigh backscatter fiber optic sensing was first validated in the laboratory and then used to measure rail strains and investigate the track behaviour over a 7.5 m long section of track at two different sites. Measurements from a hi-rail vehicle showed that the rail strains can be used to calculate rail curvature, which can then be used to assess the variability of track support.

The fiber optic sensing was then used at a second site where the measured rail strains, along with train axle weights, were used to infer the rail seat load–deflection relationships for individual sleepers. These relationships were observed to provide significantly more detailed information than the traditional consideration of the relationship between applied load and rail deflection.

The effectiveness of helical screw piles installed at a site with a peat subgrade was assessed based on the axial load carried by several piles instrumented with strain gauges, piezometric data, and track displacement measurements. The results of the analysis show that the piles carried a portion of the train load, however due to the seasonal variation of pore pressures and the limited track displacement data gathered it is not possible to ascertain how effective the piles were at improving the track behaviour.

abstract: PhD


title: Computational Modelling Methodologies and Experimental Verification of the Vibro-Acoustic Behaviour of a Section of Aircraft Fuselage

contributor:
Mechefske, Chris K.
Mechanical and Materials Engineering

subject:
Acoustics
Vibrations
Computational Modelling
Boundary Element Methods
Finite Element Methods
Experimental testing
Acoustic Testing
Transmission Loss
Acoustic Damping
Acoustic Distortion
Flanking

abstract:
An aircraft is an example of sophisticated engineering requiring a high level of understanding, where advanced modelling techniques are used to improve design. This investigation identifies noise and vibration (N&V) as principal metrics. The considered source of N&V is the Turbulent Boundary Layer that causes the aircraft fuselage skin to vibrate, generating noise inside the cabin that dominates the sound field between 100Hz and 5kHz (frequency range of interest, FRoI).
New computational methodologies (CM) are proposed to model and predict the vibro-acoustic behaviour of a section of an aircraft fuselage. The methodologies were adapted to incorporate more complex configurations, and materials. To verify these predictions, an atypical acoustic facility was commissioned to establish a new experimental methodology (EM). Several room qualification tests investigated the characteristics of the facility. The stringent criteria defined by these tests, and associated standards, were satisfied.
The principal objective of the investigation was to develop a repeatable and reproducible strategy incorporating the complementing methodologies. The principal motivation reviewed the effects of varying thickness, and milled pocket size of the interior surfaces of the fuselage panels on Transmission Loss, TL. An associative formula was developed to account for the differences (damping, distortion, and flanking) between the methodologies. These corrections were all experimentally measured.
Across the FRoI, the maximum TL error between the CM and EM for 0.04in, 0063in (milled), for a 0.063in, and 0.09in panels are 4dB, 4dB, 4dB, and 5dB, respectively; the error for the 0.063in and 0.063in (milled) panels with damping material are 9dB and 15dB, respectively. The TL error between the CM and EM across the entire frequency range (20Hz to 20kHz) for all mentioned panels vary as high as 20-25dB, however the frequency-averaged error for the 0.04in, 0.063in (milled), 0.063in, and 0.09in panels are 3dB, 3dB, 2dB, and 0dB, respectively; the frequency-averaged error for the 0.063in panel and 0.063in (milled) panels with damping material are 11dB and 17dB, respectively.
In summary, thinner panels demonstrated greater attenuation per unit of weight (despite thicker panels demonstrating greater attenuation). Similarly, the application of damping material on the interior surface of the wall demonstrated greater attenuation but did not improve the attenuation per unit of weight.

abstract: PhD


title: Effect of Low Temperature on the Static and Fatigue Behaviour of Reinforced Concrete Beams with Temperature Differentials

contributor:
Green, Mark F.
Civil Engineering

subject: Reinforced Concrete Beam (Bridge)

subject: Room and Low Temperature

subject: Temperature Differentials

subject: Shear Capacity

subject: Modified Compression Field Theory (MCFT)

subject: Cracks Widths

subject: Cracking Pattern and Distribution

subject: Static Behaviour

subject: Fatigue Behaviour

subject: Nonlinear Finite Element Analysis (NLFEA)

subject: ABAQUS

subject: Concrete Damage Plasticity

subject: Statically Determinate and Indeterminate

subject: Tension Stiffening

subject: Structural Health Monitoring (SHM)

subject: Digital Image Correlation (DIC)

subject: Particle Image Velocimetry (PIV)

subject: Measurement of Deformations

subject: Accuracy and Performance of DIC and FOS techniques

subject: Temperature Correction (Calibration) Test

abstract: This research conducted herein comprises two phases: experimental and numerical. In the experimental phase, the effect of low temperature and temperature differentials on the static and fatigue behaviour of eight large-scale reinforced concrete beams is examined. Additionally, the accuracy and performance of two novel sensor technologies, Digital Image Correlation (DIC) and Fibre Optic Strain Sensors (FOS), in monitoring crack widths, deflections and strains in reinforced concrete members are investigated. In the numerical phase, a nonlinear finite element modelling and analysis study is conducted on statically determinate and indeterminate reinforced concrete beams with and without temperature differentials. The results of the static tests showed that the strength, ductility, and cracking load of the beams increased at low temperature. The results also demonstrated that the number, depth, and widths of the cracks decreased at low temperature. The fatigue testing showed that the fatigue life of the reinforced concrete beams improved at low temperature as a result of the higher shear strength and stiffness of the reinforced concrete, the lower number of cracks with smaller widths, and improved fatigue properties of steel (i.e., delayed fatigue crack initiation and reduced fatigue crack growth rate at low temperature). Calibration tests conducted to correct DIC and FOS readings for temperature showed that both DIC and FOS systems are affected by temperature, and that the response of each DIC camera setup is uniquely affected by temperature changes. The DIC and FOS measurements showed that these structural health monitoring techniques produce promising results and are capable of measuring crack widths and strains to a similar level of accuracy as conventional strain gauges. However, the external FOS have the advantage of being able to measure the strains in concrete in compression and give an indication of the strains in the tensile reinforcement. The numerical results showed that the finite element models are capable of predicting the load displacement behaviour (i.e., cracking, yield, and ultimate loads) as well as cracking patterns for statically determinate and indeterminate reinforced concrete beams with and without temperature differentials at room and low temperature. The modelling also showed that indeterminacy (fixed-ends) substantially increases the ultimate strength of the reinforced concrete (up to 110%).

abstract: PhD


title: Exploring Parental Perceptions of a Walking-School-Bus Initiative in Northern Ontario

contributor:
Lévesque, Lucie L.
Kinesiology and Health Studies

subject:
Active transportation
School
Walking school bus
Physical activity
Northern Ontario
ATS

abstract:
Introduction: Active transportation to school (ATS) may be a way to increase children’s physical activity (PA) levels and achieve health related benefits, however only 24% of Canadian children use active transportation as a mode to travel to and from school (Gray et al., 2014). A walking-school bus (WSB) is a proposed strategy that can afford students a safe, active method of travel to school (Kearns, Collins, & Neuwelt, 2003). Few studies have examined parental perceptions of a WSB. Given that parents are typically the decision makers in regards to methods of school travel, understanding parent perceived barriers and facilitators to using a WSB is warranted.
Purpose: The primary purpose of this thesis study was to explore parental perceptions of a WSB in order to inform an effective messaging and promotional strategy. The secondary purpose was to explore barriers and facilitators related to a WSB/ATS and to explore parent ideas about ways for their children to incorporate active travel into their daily routine.

Methods:  Parents of students (N=16), from three elementary schools located in Northern Ontario were recruited. Semi-structured interviews were conducted, guided by a social marketing approach (Lee & Kotler, 2011). Inductive and deductive analyses were used to identify emerging themes and to explore product, price, promotion and place barriers and/or facilitators related to a WSB. Alternative ATS strategies were compiled.
Results: Parents identified the potential for increased levels of PA and positive social interactions as key facilitators of participating in a WSB. Other key facilitators included the opportunity to be supervised while participating in ATS, and promotion of the WSB through electronic platforms such as social media. However, parents expressed concerns regarding the safety of their children and the reliability of adult supervision of the WSB. Concerns related to extreme weather conditions were also present.

Discussion: Findings from this study will be used by the North Bay Parry Sound District Health Unit to guide WSB interventions and to develop a messaging strategy to promote WSB uptake at the participating schools as a way to enhance ATS among students.

abstract: M.Sc.


title: Effect of low intensity exercise training on circulatory and autonomic measures in patients with peripheral artery disease.

contributor:
Brown, C. Ann
Nursing

subject:
Peripheral artery disease
Exercise
Circulatory measures
Autonomic nervous system

abstract: The purpose of this study was to examine the effects of a progressive, low-intensity walking intervention on circulatory and autonomic adaptations in patients with peripheral arterial disease after controlling for potential confounders such as age, sex, ß-blockers and smoking.  Secondary objectives were 1) to determine the effect of the intervention on walking performance and self-report measures and 2) to determine if there were any sex-specific differences that might exist at rest or in response to training. Forty-eight participants (aged 67.81 ± 8.13 years, mean ± standard deviation) with intermittent claudication (ankle-brachial index 0.54 ± 0.18) were randomly assigned to either a walking group (n = 27) who performed a structured walking program, 5 days per week for 12 weeks, or a comparison group (n = 21) who performed usual activities.  Thirty-three (69%) participants (15 comparison group members and 18 walking group members) completed the study.  Circulatory measures (ankle-brachial index, heart rate, blood pressure, mean arterial pressure and rate pressure product), autonomic measures (heart rate variability, low frequency power, high frequency power, total power, parasympathetic nervous system indicator and sympathetic nervous system indicator), tests of walking performance (pain-free, functional and maximal walking distance as well as the 6 minute walk test) and self-report measures (the Walking Impairment Questionnaire and Quality of Life Questionnaire were obtained at the beginning (Week 1) and end (Week 12) of the study.  Autonomic function (heart rate variability) improved and overall walking performance increased in members of the walking group. Men and women responded similarly to the training program. These findings suggest that a structured, low-intensity, high frequency walking program is effective in improving HRV, increasing walking performance and daily walking distance.

abstract: PhD


title: The effects of climate and humic substances on disinfection performance in Arctic wastewater stabilization ponds

contributor:
Champagne, Pascale
Civil Engineering

subject:
Disinfection
Photo-Oxidation
WSP
Inuit
Indigenous
Source Water Protection

abstract:
This thesis is an investigation of disinfection in wastewater stabilization ponds (WSPs) as it relates to adequate wastewater treatment and, ultimately source water protection (SWP) in northern, particularly Indigenous, communities. WSPs are considered sustainable utilitarian wastewater treatment technologies that are cost efficient and require minimal operation and maintenance. However, their performance is highly dependent on environmental conditions and disinfection performance, specifically, can be compromised in northern climates. The research is motivated by the following question: are there any simple approaches that could improve WSP disinfection without the need for conversion to a full-scale conventional treatment plant?

The first study compared the ability of existing models in predicting cold climate disinfection performance in WSPs by comparing their predictions of mortality rates for fecal coliform bacteria with rates observed in a single-stage WSP in Pond Inlet, NU, during the 2015 treatment season. The results of this study demonstrated that existing models exhibit limitations in representing disinfection performance in Arctic WSPs.

The second study focused on the development of a sunlight-mediated disinfection model for cold climate WSPs. A 2k factorial design was implemented to enable the examination of interaction effects of independent predictor variables related to sunlight-mediated disinfection (pH, dissolved oxygen, depth-averaged irradiance) on the mortality rates of  Escherichia coli ATCC 11229.  A controlled atmosphere chamber (CAC) was designed to control these parameters. Mortality rates between -0.8198-1.1057 h^-1 were observed throughout the experiments. A numerical model was presented and demonstrated a significant fit (p<0.001) to the data collected in the experiment. Temperature was found to have a more complex relationship with disinfection than previously thought, likely affecting both the growth and death rates of E. coli.

In addition, the effect of humic substances (HS) concentrations (0 - 30 mg/L) on disinfection performance was investigated. Higher HS concentrations were found to improve disinfection performance when the conditions supporting exogenous photo-oxidation were present. Recent literature has shown that HS concentrations are positively correlated to solids retention time in membrane bioreactor systems which could indicate a similar relationship with hydraulic retention time in WSPs.  Finally, suggestions are made for future WSP configurations to enhance disinfection performance.

abstract: M.A.Sc.


title: Automated Approaches for Reducing the Execution Time of Performance Tests

contributor:
Hassan, Ahmed E.
Computing

subject: Performance Tests, Software Engineering

abstract:
Performance issues are one of the primary causes of failures in today’s large-scale software systems. Hence, performance testing has become an essential software quality assurance tool. However, performance testing faces many challenges. One challenge is determining how long a performance test must run. Performance tests often run for hours or days to uncover performance issues (e.g., memory leaks). However, much of the data that is generated during a performance test is repetitive. Performance testers can stop their performance tests (to reduce the time to market and the costs of performance testing) when the test no longer offers new information about the system’s performance. Therefore, in this thesis, we propose two automated approaches that reduce the execution time of performance tests by measuring the repetitiveness in the performance metrics that are collected during a test.

The first approach measures repetitiveness in the values of the performance metric, e.g., CPU utilization, during a performance test. Then, the approach provides a recommendation to stop the test when the generated performance metric values become highly repetitive and the repetitiveness is stabilized (i.e., relatively little new information about the systems’ performance is generated). The second approach also recommends the stopping of a performance test, by measuring the repetitiveness in the inter-metrics relations. Our second approach combines the values of the performance metrics that are generated at a given time into a system state. For instance, a system state can be the combination of a low CPU utilization value and a high response time value. Our second approach recommends a stopping time when the generated system states during a performance test become highly repetitive.

We performed experiments on three open source systems (i.e., CloudStore, Pet- Clinic and Dell DVD Store). Our experiments show that our first approach reduces the duration of 24-hour performance tests by up to 75% while capturing more than 91.9% of the collected performance metric values. In addition, our approach recommends a stopping time that is close to the most cost-effective stopping time (i.e., the stopping time that minimizes the duration of a test while maximizing the amount of information about the system’s performance as provided by the performance test). Our second approach was also evaluated using the same set of systems. We find that the second approach saves approximately 70% of the execution time while preserving at least 95% of the collected system states during a 24-hour time period. Our comparison of the two approaches reveals that the second approach recommends the stopping of tests at more cost-effective times, in comparison to our first approach.

abstract: M.Sc.


title: The Reasonable Person in Criminal Law

contributor:
Sypnowich, Christine
Philosophy

subject:
Reasonableness
Philosophy
Legal studies
The Reasonable Person

abstract: The reasonable person standard has permeated the legal sphere as a guideline for determining the appropriate judgment in various situations.  If one is to be justified, he or she must have acted as a reasonable person would have under the same or similar circumstances. While there are advantages to relying on this universal understanding of reasonableness, there are serious doubts about whether or not such a standard is consistent with the demands of justice. The reasonable person is a difficult concept in law because it aims to objectively assess the behaviour of individuals of different backgrounds, different standings in society and different points of view. The problem is that every individual is bound to have their own idea of what it means to be reasonable based on his or her own experience. Judges and jurors thus often end up ascribing particular characteristics to the reasonable person that are derived from an understanding of the society in which they live. The result is a standard that is both inconsistently defined and insensitive to human diversity. In distinguishing reasonableness from mere rationality it is evident that the main defining feature of the reasonable person is that he or she considers their own interests and the interests of others equally. This thesis defends the idea that in order to properly account for variation in individual circumstances, criminal courts ought to define the reasonable person more clearly by reference to an ethic or standard of care similar to the one endorsed in Canadian and UK civil law. Having an ethic of care model of reasonableness as a jurisprudential guide will help prevent judges and jurors from mistakenly relying on average or rational conceptions of reasonable behaviour as well as foster sensitivity to individual differences and needs.

abstract: M.A.


title: MagicWand: A Comparison of Gestural Affordances Between Cylindrical and Flat Display Form Factors

contributor:
Vertegaal, Roel
Computing

subject:
Display Objects
Cylindrical Device
Mobile
Motion Gestures
Human Computer Interaction

abstract:
An affordance is the intrinsic ability of an object to allow an action. Affordances are generated by matching the fit of the body under action to the physical shape of the object. For example, a vertical door handle affords pulling, whereas a horizontal flat bar affords pushing to open. Modern smartphones with traditional flat screens offer poor affordances for gestural interactions. E.g., the flat form factor prevents a comfortable grip hindering wrist movements. Moreover, flat displays have a display area that can only be viewed from one side, and the visibility is reduced when the device is rotated.
In this thesis, we present MagicWand, a cylindrical display device consisting of two 5.5” Flexible Organic Light-Emitting Diode (FOLED) screens wrapped around a 3D printed body. MagicWand features a smartphone running the Android operating system. Gesture recognition allows the use of the wand movements as a form of input. We were interested in exploring how a cylindrical form factor will offer physical affordances for actions that are quite different from those of a traditional flat form factor of a smartphone.
To exhibit interactions with our prototype, an application scenario was developed where MagicWand was used as a game controller that can display a variety of 3D game elements. We believed that the physical affordance of this novel display device could affect the speed with which users learned specific gestures to operate the graphical elements on display. We conducted a user study to compare the guessability of gesture sets between flat and cylindrical device conditions. First, gestures were elicited for invoking common Graphical User Interface tasks in both device conditions, collecting over 100 unique gestures for 29 tasks. Second, a recognition engine was trained to recognize the top gestures for each task, for each device condition. Third, we measured the time it took for participants to discover these top gestures.
The results of the study suggest significantly faster discovery of input gestures in the cylindrical condition over the flat device with 20 percent of gestures, specifically those involving tilt.

abstract: M.Sc.


title: Alliance Politics, Solidarity Praxis, Precarious Alliances: A Case of the Anti-Capitalist Muslims in Turkey

contributor:
Salzmann, Ariel
Cultural Studies

subject:
Alliance Politics
Social Movements
Dissident Politics
Islamism
Neoliberal Populism
Turkey
Solidarity
Collective Action

abstract:
This dissertation focuses on a dissident youth group in Turkey which came to national and international attention during the uprisings of May- June 2013 and dissolved two years later.  The Anti-Capitalist Muslims (A-C M) were a meeting ground for individuals from different walks of life but influenced  by the critical, Islamist writings of noted Turkish thinker and author, Ihsan Eliacik. My investigation saw the A-C M as a ground of investigation for understanding the potentiality and challenges of solidarity praxis across what had previously been thought to be historically and politically conflicting political groups. Specifically, it seeks to answer several questions: first, what are the roots of this encounter between Turkish Left and a Social Justice-centered interpretation of Islam? Second, what were the terms upon which this diverse group of individuals coalesced? Third, how did their work together transform their own political understanding? Fourth, what lessons can be drawn from this experiment for the future of political labour in Turkey and elsewhere in the world?
	The dissertation is  anchored in a theoretical framework which brings together a broad historical perspective on identity politics and the politics of alliance with reflection on radical labor movements in the Turkish context. In an era in which dissident movements and radical politics both produced and destabilized by the neoliberal trends and re-structuring of state and economy, I argue that the A-C M represents a new type of solidarity/alliance building which are based on transitory political alignments what I call “precarious alliances”.  As a concept, the notion of the precariousness of such transitory coalitions offers both a critique to the existing analysis of the process of making alliances and a re-imagination of the terms upon which individuals unite. I suggest that precarious alliances might serve as more than an analytical tool; indeed, for the A-C M it served as a radical political strategy.  Moreover, in situating, theoretically and contextually, the A-C M experience in a time of greater social mobilization globally, I hope to contribute to the larger debates on solidarity building among youth of diverse ideologies and positionalities.

abstract: PhD


title: Back and Forth: Prediction and Interactive Alignment in Conversation

contributor:
Munhall, Kevin G.
Psychology

subject:
Conversation
Social Perception
Conversational Prediction
Conversational Alignment

abstract: On a daily basis, we engage in multiple conversations with others that seem to occur effortlessly. Despite this apparent ease, the cognitive processes involved in conversation are complex. The challenges associated with conversation include comprehending our partner while simultaneously planning our own contributions and ensuring that what we say is appropriate to the conversational context. The paradoxical ease of this cognitively demanding activity suggests that we may employ a specialized mechanism when engaging in conversation. This dissertation investigates two potential processes that may be involved during social interaction: conversational prediction and alignment. Chapters 2 and 3 of this thesis investigate the perceptual conditions that are necessary for making predictions during conversation. In particular, we investigate how the availability of information influences how we are able to predict a turn exchange during conversation. We present findings that demonstrate that perceivers can predict upcoming turn exchange behavior between two talkers. Further, we suggest that auditory and visual cues serve distinct roles in the predictive processes involved in conversation. Chapters 4, 5 and 6 investigate behavioral alignment in social interaction. In general, it has been shown that conversing talkers align several aspects of their behavior. Talkers have independently been shown to become similar in linguistic attributes such as the words they use and nonlinguistic attributes such as their movement patterns during an interaction. Here, our findings demonstrate that talkers, in fact, align multiple attributes during a single conversation. In addition, there are relationships between alignment behavior within these attributes; when talkers become similar within one attribute, they are more likely to become similar within another attribute. Further, we show that this alignment behavior is influenced by the relationship between talkers suggesting that social factors play a significant role in our conversational behavior. Taken together, this dissertation demonstrates that prediction and alignment behavior are key features of conversational interaction. In particular, we demonstrate that the informational and social context of a conversation determine how these important processes operate. These findings have important implications for the identification of the specific underlying mechanism that is responsible for ensuring the success of our daily communication.

abstract: PhD


title: Design and characterization of absorbent polymers for two-phase partitioning bioreactor applications

contributor:
Daugulis, Andrew J.
Chemical Engineering

subject:
two-phase partitioning bioreactor
extractive fermentation
bioremediation
polymer chemistry
polymer modification
thermodynamics

abstract:
The production of fuels and chemicals from renewable biomass feedstocks can reduce our reliance on petroleum resources and help mitigate environmental issues associated with their use. However, many bioprocesses are limited by end-product inhibition, leading to lower product titer and reduced bioreactor productivity. Introducing a carefully selected solid absorbent polymer can reduce end-product inhibition by removing the product as it is formed and enriching it within the polymer phase. To be effective, the polymer must possess (1) a high affinity for the target solute, measured by its partition coefficient (PC), (2) a preference for solute absorption over water uptake, measured by selectivity (α), (3) biocompatibility towards the microorganism, and (4) sufficient physical strength to withstand the high shear bioreactor environment.
The present work begins with an evaluation of thermodynamic activity models for a priori polymer phase selection. Accurate PC predictions were demonstrated for a range of target solutes in rubbery, amorphous materials. Further, polymer selection based on PC was shown to favor low molecular weight (MW) materials, whereas higher MW polymer yielded stronger, more solid-like absorbents. Compromises between absorptive and physical properties inherent to unimodal molecular weight distribution (MWD) polymers were mitigated by developing novel bimodal MWD formulations, made from mixing very low MW material (organic solvent or oligomer) with a high MW polymer. Solute absorption was also sensitive towards polymer crystallinity and water uptake; these factors were captured qualitatively by the thermodynamic models but with significantly reduced prediction accuracy.
Remarkable improvements in both PC and α for n-butanol and n-octanol were realized by covalently tethering small amounts of imidazolium ionic functionality to a hydrophobic polymer, yielding an ionomer. Further improvements were achieved by preparing high ionic content polyelectrolytes, polymerized from reactive imidazolium ionic liquids (IL). The polyelectrolytes registered excellent PC values for several alcohols (n-butanol, iso-butanol, ethanol) as well as good solute/water selectivity. Importantly, both ionomer and hydrophobic polyelectrolyte formulations substantially eliminated cytotoxicity and water-solubility concerns associated with analogous ILs. These findings advance the state-of-the-art in absorbent materials for bioprocess separations and represent a promising avenue for future partitioning bioreactor research.

abstract: PhD