VictorJuiz/thesis huggingface dataset:
Thermal and Electrical Properties of Graphene-based Polymer Nanocomposite Foams

Recently, multifunctional polymer-graphene nanoplatelet (GnP) composites have demonstrated great promise as next-generation materials for energy management and storage, electromagnetic interference (EMI) shielding and heat dissipation components in electronic industries. However, the practical underpinning needed to economically manufacture graphene-based polymer composites is missing. Therefore, this dissertation aims to demonstrate how some of the challenges for efficient manufacturing of functional polymer composites, can be strategically tackled by using supercritical fluid (SCF)-treatment and physical foaming technologies. In this PhD research, an industrial-scale technique for in situ exfoliation and dispersion of GnP in polymer matrices was developed and invented. This thesis also developed an in-depth understanding of the effects of cellular structures, GnPs’ orientation, arrangement, and exfoliation on the thermal/electrical conductivity, percolation threshold, dielectric performance, and EMI shielding effectiveness of the graphene-based polymer composites. In particular, it was demonstrated how SCF−treatment and physical foaming can significantly enhance thermal conductivity of polymer-GnP composites. The SCF-treatment and physical foaming exfoliated the GnPs in situ and microscopically tailored the nanocomposites’ structure to enhance the thermal conductivity. The research findings in this thesis have also demonstrated that the introduction of foaming and microcellular structure can substantially increase the electrical conductivity, EMI shielding effectiveness and can decrease the percolation threshold of the polymer-GnP composites. This research also presented a facile technique for manufacturing a new class of ultralight polymer-GnP composite foams with excellent dielectric performance. The generation of a microcellular structure provided a unique parallel-plate arrangement of GnPs around the cell walls. This significantly increased the real permittivity and decreased the dielectric loss. This dissertation developed a fundamental understanding of structure-property relationships and new routes to microscopically engineer the structures and properties of graphene-based polymer composites for various application such as heat management (heat sink materials), EMI shielding, energy storage and capacitors (dielectric materials).

Keywords: Electrical Conductivity
Graphene
Graphene-Polymer Nanocomposites
Microcellular Foam Processing
Polymer Processing
Thermal Conductivity
Advisor: Park, Chul B.
Filleter, Tobin
Polarimetry for Breast Cancer Imaging

Medical imaging is vital to the successful management of breast cancer. This thesis investigated polarimetry for breast cancer imaging. Polarimetry is the use of polarized light to study properties of matter. The main contributions of this thesis can be divided into those which expand the capabilities of experimental polarimetry, and those which explore polarimetry as a method for breast cancer imaging. Towards an improved polarimetry platform, work was done to test the importance of appropriately selecting which types of polarized light to use for polarimetry measurements. Specifically, an optimum set of input polarization states was experimentally validated for use with a dual photoelastic modulator (PEM) polarimeter. Further, two new polarimetry imaging systems were developed. The first was designed to enable faster polarimetry imaging. A rapid imaging system based on PEMs and a charge-coupled device (CCD) camera was built, calibrated, and used to image biological phantoms. The second imaging system was designed to enable accessible multiscale polarimetry imaging. A removable polarimetry module was designed and built for use with a commercial microscope. Polarimetry was investigated as an imaging method for two important aspects of breast cancer, specifically, breast cancer margins, and collagen organization. The breast cancer margin work was done in the context of providing image-guidance for mass spectrometry. Mass spectrometry is a technique for sensitively acquiring tissue chemical signatures, but is hindered by long imaging times. Polarimetry was found to rapidly differentiate human breast cancer from healthy tissue in a mouse model of breast cancer. It could also identify necrosis in breast cancer lymph node metastases. These findings are promising for polarimetry-guided mass spectrometry. Finally, polarimetry was investigated for imaging collagen organization in a mouse model of breast cancer. A direct comparison with second harmonic generation (SHG) imaging found that polarimetry detects organizational contrast different from that arising exclusively from collagen. Polarimetry shows potential for breast cancer imaging, whether on its own or paired with other techniques such as mass spectrometry. The hope is that the findings of this thesis will help guide the continued development of polarimetry, both for breast cancer, and biomedicine in general.

Keywords: Breast Cancer
Collagen
Polarimetry
Polarized Light
Tumour Margins
Advisor: Vitkin, Alex
Allons Enfants de la Patrie: An Analysis and Defence of Patriotism and the Social Self

My dissertation is a rehabilitation of patriotism as a virtue. The initial theory building corrects for the often vague or empirically unsupported characterizations of the phenomenon. More precisely, I draw on the field of nationalism studies as well as research in economics and social psychology to produce an empirically grounded account. On my view, patriotism is not analogous to personal loyalty because it depends upon a common identity and an intergenerational entity; it is a collective form of loyalty that engages with collective self-understanding. Moreover, I argue that patriotism is predominantly cultural rather than political as loyalty and identity predate and survive regime changes. My defence of patriotism is two-pronged. First, I demonstrate that Charles Taylor’s argument that patriotism is necessary for a well-functioning democracy is best served by a cultural view of patriotism rather than a political version. The key problem is that a patriotism dependent upon a purely political social identity is unable to reliably sustain collective loyalty. Second, I argue that patriotism can make a distinct contribution to human flourishing through what I call deindividuated flourishing. Building upon insights from social psychology, I argue that human flourishing should be understood in both personal and collective terms. The latter is characterized by collective self-understanding and collectivizing the parameters of success. Patriotism, by allowing us to engage in large-scale and intergenerational projects, allows for deindividuated flourishing.

Keywords: Flourishing
Loyalty
Patriotism
Social Identity
Virtue
Advisor: Hurka, Thomas
Clark, Philip
Scalar and Tensorial Metasurfaces from Microwaves to Optics

This thesis explores engineering of the scattered wavefronts, from microwaves to optics, with metasurfaces comprising arrays of polarizable, subwavelength-sized particles. The scalar and tensorial aspects of wavefront manipulation are considered based on four novel metasurfaces. The aim of the scalar wavefront manipulation is to achieve complete control over the reflected wavefront without inducing unwanted spurious fields, while the aim of the tensorial metasurfaces is to realize chiral polarization control. For the scalar wavefront engineering, an optical Huygens' metasurface and a vanadium-dioxide metasurface have been devised that respectively leverage the Schelkunoff's equivalence principle and the theory of holography. A detailed analysis on an optical Huygens' metasurface is presented whereby surface losses, which have heretofore been considered merely as an undesirable feature, have been discovered to play a critical role in suppressing unwanted excitations. An investigation has also been conducted on reconfigurable scalar metasurfaces through the demonstration of a vanadium-dioxide metasurface in which the reconfigurability is attained via a large refractive index change enabled in vanadium dioxide. Instead of relying on surface losses, however, the proposed vanadium-dioxide metasurface judiciously assigns unwanted fields in the `invisible region' such that only the desired reflected fields are excited in the far-field zone. In a departure from scalar wavefront engineering, this thesis also presents optical and microwave tensorial metasurfaces for chiral polarization manipulation. For this purpose, a highly efficient optical circular polarization selective surface is demonstrated by cascading rotated silicon nanorods. The design methodology, which employs multi-conductor transmission line theory, is discussed. In the microwave regime, dual-band tensorial metasurfaces are presented. The analysis involves combining a semi-analytical method with a nonlinear optimization technique. Their physical realization is also discussed along with numerical and experimental verifications at microwaves.

Keywords: Chiral metasurfaces
Huygens' metasurfaces
Impedance surfaces
Metasrfaces
Reflectarrays
Transmitarrays
Advisor: Eleftheriades, George V
Protecting Persistent Data with Run-time Invariant Checking

This thesis describes how we use run-time invariant checking to protect data from corruption originating at high levels in the storage stack. In concert with existing techniques for protection against corruption in the lower levels of the storage stack, we make guarantees of data structure consistency in file systems and other storage applications. We address the when, what, and how of run-time invariant checking. The fundamental requirement is that the application is crash consistent, ensuring there is a suitable point in logical time when it is safe to check the invariants. The consistency point provides us a point in time when we can check invariants, and an opportunity to check the invariants before the corrupt writes take effect. Every file system, database, or other storage application has its own data structures, and hence its own consistency invariants. We emphasize checking incrementally because of the scale of data in persistent storage. Our systems check updates for consistency using differential invariants, which are derived from global invariants. Differential invariants compare the old and new states to determine precisely what needs to be checked so the global invariants are not violated by the update. They rely on the consistency of the previous state, so our checking relies on storage systems using other mechanisms to ensure checked data is preserved. In addition to consistency invariants, we also check the atomicity and durability invariants of file system crash consistency mechanisms. Our evaluation shows the overheads of incremental checking are reasonable. For the Ext3 and Btrfs file systems, the performance overhead of runtime consistency checking is largely masked by device latency. For persistent memory, we see a more substantial overhead, from 10%-50% in our Redis benchmarks. These numbers are also significantly affected by the choice of persistent memory framework adopted, and this is an opportunity for future improvement as more efficient frameworks are developed.

Keywords: atomicity
consistency
data corruption
integrity checking
operating systems
storage systems
Advisor: Goel, Ashvin
Demke Brown, Angela
Interactions and Functions of the Ubiquitin Specific Protease 7 in Human Cells

The ubiquitin-specific protease 7 (USP7) is a deubiquitylating enzyme that regulates many important cellular processes and is highly studied for its contributions to cancer. Our lab has previously discovered a binding pocket in the USP7 N-terminal TRAF domain that mediates interactions with target proteins. In this thesis I demonstrate how I contributed to the identification of a second binding pocket located in the Ubl2 ubiquitin-like structure of the USP7 C-terminal domain. Furthermore, to gain a more comprehensive understanding of the interactions and functions of USP7, I used a proteomics approach to profile USP7 interactions in cancer cells. This confirmed reported associations of USP7 with USP11, PPM1G phosphatase and TRIP12 and identified novel interactions with FBXO38 and two DEAD/DEAH-box RNA helicases, DDX24 and DHX40. I show that USP11, PPM1G, DDX24, TRIP12 and FBXO38 bind USP7 through its TRAF binding pocket, while DHX40 interacts through the Ubl2 pocket. Motifs in USP11 and DDX24 that are critical for USP7 binding were also identified. Modulation of USP7 expression levels and inhibition of USP7 catalytic activity showed that USP7 consistently stabilizes DDX24, DHX40, TRIP12 and FBXO38 dependent on its catalytic activity, while USP11 and PPM1G levels were not consistently affected. Together these results better define the mechanisms of USP7 interactions and identify FBXO38, DDX24, and DHX40 as new USP7 targets. Furthermore, a BioID approach was used to profile the interactions and putative functions of FBXO38, revealing an interaction with KIF20B, a Kinesin-6 protein required for cytokinesis. I show that depletion of either FBXO38 or USP7 result in dramatic decreases in total KIF20B levels and its localization to the midbody, which were manifested in cytokinetic defects. Furthermore, cytokinetic defects associated with USP7 silencing were rescued by restoring FBXO38 or KIF20B. Therefore, I have identified novel roles for USP7 and FBXO38 in the regulation of cytokinesis.

Keywords: Deubiquitylation
Interactions
proteomics
Ubiquitin
USP7
Advisor: Frappier, Lori
Coarse-grained Theory and Simulation of Assemblies of Intrinsically-disordered Nucleoporins

Selective import and export through the nuclear envelope in the eukaryotic cell is solely regulated by the transporter known as Nuclear Pore Complex (NPC). The transport conduit of the NPC is occupied by intrinsically-disordered nuclear pore proteins collectively known as FG nucleoporins, which confer selectivity to the pore, hindering the passage of large, neutral molecules while facilitating the translocation of cargos recognized by carriers known as transport proteins. Currently, the mechanism of selectivity and permeability behaviour of the NPC is a subject of intense research, though much of our understanding of the NPC is based on inferences from experiments on in vitro assemblies of FG nucleoporins, requiring rigorous analysis through a theoretical framework. In this thesis, employing approaches based on mean field theory and numerical simulations, I investigate the behaviours of in vitro assemblies of FG nucleoporins under conditions commonly studied in experiments. The models studied in this thesis depend on the most important interaction and geometric parameters of the system, but are capable of providing semi-quantitative descriptions of experimental results. In addition, these models provide the means to characterize the effective interactions between the FG nucleoporin assemblies and transport proteins, and translate equilibrium measurements of these interactions into the dynamics of transport. In all types of FG nucleoporin assemblies, different entropic and enthalpic effects stemming from molecular interactions determine the affinity between FG nucleoporin and transport proteins, demonstrating the physics of the in vitro assemblies that are expected to arise in the NPC.

Keywords: Intrinsically disordered proteins
Nuclear Pore Complex
Nucleoporins
Polymers
Advisor: Zilman, Anton
Craft and the Contemporary Geographies of Manufacturing: Local Embeddedness, New Workspaces, and the Glamourization of Work in the Craft Brewing Sector

Craft forms of production have enjoyed a notable revival in recent decades and have been argued to provide a source of competitive advantage in a post-Fordist economic landscape. Craft combines physical manufacturing with creative production to produce objects imbued with notions of quality, authenticity, skill, and bespoke production. Craft elevates particular practices and processes, which has allowed it to become viewed as a more environmentally responsible and socially just way of organizing production. This dissertation explores the normative landscape of craft, emphasizing the implications it has for contemporary geographies of manufacturing. Drawing on a mixed methods approach, and an in-depth case study of the craft brewing sector in Portland, Oregon, the dissertation highlights three unique geographies associated with contemporary craft manufacturing. First, the dissertation highlights a tendency towards spatial agglomeration and a (re)localization of small-scale production in advanced economies. It traces the development of Portland’s craft brewing cluster, highlighting the significant role that place-specific institutional and material factors have played in the emergence and growth of the cluster. Second, the dissertation highlights a heightened perception and desirability of manufacturing work associated with the contemporary resurgence of craft, despite the presence of precarious working conditions in craft sectors. A key finding of the dissertation is that precarious working conditions are actually being exacerbated by the heightened status of craft brewing work. Finally, the dissertation highlights a fusion of industrial and cultural production associated with the recent craft revival and documents the ways this has transformed industrial workspaces. In particular, the dissertation emphasizes the unique spatial and locational requirements of craft breweries as well as the ways that their workspaces are enlisted to serve both production and consumption functions. It also places the material landscape of craft beer production in conversation with urban planning, revealing the ways in which craft breweries are used by policy-makers to promote gentrification, tourism and neighbourhood branding and the ways in which these policies are simultaneously benefitting and threatening the continued existence of Portland’s significant craft brewing cluster.

Keywords: Brewing
Craft
Manufacturing
Portland
Oregon
Advisor: Leslie, Deborah
Early Childhood Educators' Knowledge and Self-efficacy in Foundational Literacy Instruction

This thesis is comprised of two studies. The first utilizes a mixed-method approach and explores early childhood educators’ early literacy knowledge and self-efficacy for early literacy instruction. Fifty-four ECEs participated in this research, of which 29 were pre-service ECEs and 25 were in-service ECEs. Participants were assessed on their early literacy knowledge and self-efficacy for early literacy instruction. They were also assessed on their early literacy-related experiences, including assessments of their literacy-related training and practicum experiences as well as assessments of their professional experiences. Study 1 revealed significant gaps in ECEs’ early literacy knowledge, and identified differences between pre-service and in-service ECEs in their early literacy knowledge and experiences. The findings of study 1 showed that despite their varied early literacy-related experiences and training, both pre-service and in-service ECEs lacked adequate knowledge and self-efficacy in phonemic awareness and oral language instruction, two essential components of early literacy education. The second study is a mixed methods study examining the impact of a targeted professional development intervention designed to improve knowledge and self-efficacy in phonemic awareness and oral language instruction. Study 2 found that the professional development intervention was effective in improving both knowledge and self-efficacy in phonemic awareness and oral language instruction. Qualitative findings provided further insight as to specific components of the intervention that were seen as beneficial in improving the knowledge and self-efficacy of ECEs, which included opportunities to apply theoretical learning through hands-on activities and video demonstrations. Overall, the findings of this thesis provide insight into the early literacy experiences, knowledge and self-efficacy for early literacy instruction of pre-service and in-service ECEs. Furthermore, the findings suggest that ECEs can make significant improvements in knowledge and self-efficacy through a targeted professional development intervention.

Keywords: Early Childhood Educator
Knowledge
Literacy
Oral Language
Phonemic Awareness
Self-Efficacy
Advisor: Willows, Dale
Computer-aided Diagnosis for MRI Screening of the Breast in High Risk Women

Breast cancer is currently the second leading cause of death from cancer in Canadian women. Routine mammograms are considered the best screening approach for early detection in the general population but magnetic resonance imaging (MRI) is recommended in addition to mammography to women at high risk of developing breast cancer. The main reason for this recommendation is the high sensitivity attributed to the characteristic uptake of gadolinium contrast agent by cancerous lesions during T1-weighted (T1w) dynamic contrast-enhanced (DCE) imaging. Dynamic lesion characteristics such as time-course uptake, morphology, and enhancement type patterns known as mass, non-mass or foci (

Keywords: Cancer detection and diagnosis
Computer-aided diagnosis
Decision tree classifiers
Magnetic resonance imaging
Advisor: Martel, Anne L
Evolving Intentions: Support for Modeling and Reasoning about Requirements that Change over Time

In early-phase requirements engineering, modeling stakeholder goals and intentions helps stakeholders understand the problem context and evaluate tradeoffs, by exploring possible "what if" questions. Prior research allows modelers to make evaluation assignments to desired goals and generate possible selections for task and dependency alternatives, but this treats models as static snapshots, where once the evaluation of the fulfillment of an intention is determined, it remains constant. Using these techniques stakeholders are unable to reason about possible evolutions, leaving questions about project viability unanswered when the fulfillment of goals or availability of components is not guaranteed in the future. In this dissertation, we propose Evolving Intentions: a framework for specifying, modeling, and reasoning about goals that change over time, enabling stakeholders to explore model evolution. We present Evolving Intentions in the context of both the i* and Tropos goal modeling languages. We specify a set of functions that define how intentions and relationships evolve, and use simulation strategies for asking a variety of "what if" questions about such changes. We present GrowingLeaf and BloomingLeaf, two web-based goal modeling and analysis tools that implement this technique for iStar and Tropos models, respectively. Using the development of GrowingLeaf as an example, we demonstrate that this technique is effective for debugging goal models and answering stakeholder questions, and show the analysis to be scalable for representative goal models. We describe a between-subjects controlled experiment that empirically validated the effectiveness of our approach and tool usability. We also report on the applicability and effectiveness, of our technique on a substantial case, where we use historical data and rational reconstruction to understand how a project evolved in the past, and explore alternative futures.

Advisor: Chechik, Marsha