VictorJuiz/thesis huggingface dataset:
Evaluation of finite element formulations to determine the ballistic response of advanced materials

The considerable mass of armour composed of conventional materials has stimulated research into lightweight alternatives. Candidates include nanocrystalline metals, whose strength-to-weight ratios are superior to their polycrystalline counterparts. However, their potential for armour has not been previously explored in the open literature. Finite element analysis has become a popular tool to predict armour response. Nevertheless, literature on large deformation, high strain rate modeling is scarce. In this investigation, three finite element formulations were evaluated using the hydrocode LS-DYNA. Comparisons with experimental results are presented for each. The arbitrary Lagrangian-Eulerian formulation was best suited, owing to its appropriate handling of large deformation. Simulations were also conducted to locate trends for material selection. A parametric study revealed that maximizing solidus temperature and heat capacity significantly improved penetration resistance. As well, comparisons of nanocrystalline nickel by grain size suggested that toughness had a greater effect on penetration resistance than strength alone.
Platelet procoagulant surface expression: Persistence and relation to apoptosis

Expression of procoagulant phosphatidylserine (PS) on activated platelets participates in the acceleration of blood coagulation. Unexpectedly, PS exposure on activated platelets is maintained; the mechanism by which this occurs in not well understood and may involve apoptotic-like events. We showed that PS expression on platelets activated with thrombin and/or collagen, or Ca 2+-ionophore A23187, persists in vitro for up to 4 hr, and occurs in the presence or absence of another marker of apoptosis, that of mitochondrial inner membrane potential (DeltaPsim) collapse. We also showed that aminophospholipid translocase (APLT) activity in PS-expressing platelets remained decreased for up to 4 hr after platelet activation, providing an explanation for the persistence of PS expression on activated platelets. Indeed, we also showed that PS-expressing platelets had elevated [Ca2+] i, up to 4 hr after activation. Since APLT activity is inhibited by increases in [Ca2+]i, sustained elevations in [Ca 2+]i could account for the sustained reduction in APLT activity.
Cultural sensitivity as a problematic in Ontario nursing policy and education: an integrated feminist con

Transcultural nursing (TCN) theory is one of the most visible forces shaping the dialogue about inclusivity in nursing. TCN theory advances a liberal, humanistic approach to race and race difference that frames nursing research, policy, education, and practice. Using an integrated feminist con/textual analysis, this research interrogated the articulation of TCN theory in three sets of nursing texts that organize the social relations among nurses and between nurses and clients. This investigation highlights the links between a College of Nurses of Ontario (CNO) standard of practice on culture care, curricular texts introducing cultural sensitivity and the TCN literature that supported the development of both in two concrete locations. The institutional texts and the contexts in which they operate were viewed in light of the anti-racism discourse advanced in sociological and educational literature. My general orientation was to explore what nursing institutions were saying about race and race difference through the texts they developed and used, and to expose and name the logical implications of this discourse. From there, I imagined what these same institutions might say and do in moving toward a more inclusive, anti-racism nursing discourse. Conclusions emerging from my analysis demonstrate the power of nursing con/texts to assert the dominant white discourse about race and other social differences that sustains rather than challenges the racialized social order. These findings contribute to the theory and practice of nursing and the broader dialogue about inclusive education in three ways: First, these conclusions illustrate the links between TCN literature, CNO policy and educational practice, and the value of looking to anti-racism discourse for a revisioning of inclusive education. Second, a set of diagnostic questions provides a tool for exposing racist discourse in textual knowledges. Third, using a broadly defined discursive framework, I identify spaces for systemic change in a revisioning of inclusive nursing research, policy and curricula.

Keywords: Nursing
Health
Health promotion
An agent-based simulation of double-auction markets

Agent-based simulation has emerged as a promising research alternative to the traditional analytical approach in studying financial markets. The idea behind agent-based simulation is to constructively model a market in a bottom-up fashion using artificial agents. This thesis aims to accomplish four objectives. The first objective is to present a high-quality software platform that is capable of carrying out agent-based financial market simulations. The second objective is to simulate a double-auction market with this software platform, using homogeneous zero-intelligence agents. The simulation is based on the artificial market model proposed by Smith; Farmer, Gillermot and Krishnamurthy (2003). The third objective is to study the microstructure properties of the simulated double-auction market. In particular, we investigate certain statistical properties for the mid-price, bid-ask spread and limit order book. The fourth and the last objective is to explore and evaluate trading strategies associated with the time-constrained asset liquidation problem through computational agents.
Manufacture of fine-celled plastic/wood-fiber composite foams using CO2 as a blowing agent

This thesis is intended to investigate the feasibility of continuous extrusion processing of fine-celled plastic/wood-fiber composite foams with a high wood-fiber content (50%). The main benefits of incorporating wood-fibers in plastics are the increased stiffness and lowered cost of the resulting composites. However, these improvements are usually accompanied by sacrifices in the ductility and impact resistance. These shortcomings can be removed by effectively foaming and incorporating a fine-celled structure in these composites. The moisture released from wood-fiber during processing is known to deteriorate the cell structure. CO2, an environmental benign PBA, not limited by the decomposition temperature of CBA, was used as a blowing agent. A strategy of lowering the maximum processing temperature to suppress the moisture generation from wood-fiber was applied in this study. The lowest processing temperature and the optimal gas injection amount were identified, which successfully achieved the desired density 0.5–0.8 g/cm 3 of the plastic/wood-fiber composite foam with a fine-cell structure.
Visualization of polymer foaming using a batch foaming simulation system with a high pressure-drop rate

An innovative batch foaming simulation system was designed and constructed in order to elucidate the mechanisms of bubble formation and growth during polymer foaming. A theoretical model to simulate the pressure and pressure-drop in the batch foaming chamber was derived. The system was experimentally verified using polystyrene (PS 101) and CO2. Using the batch foaming simulation system, the bubble formation and growth occurring inside specific polymer samples (PS685D) and at the interface between the samples and a sapphire window were studied. It was found that bubble formation inside the polymer required a higher supersaturation than bubble formation at the interface because of the smaller critical radius induced by the higher degree of supersaturation. Finally, the bubble formation and life span of polymer with chemical blowing agent (CBA) blown under atmospheric and high pressure were studied. The system was further used to investigate the foaming of polystyrene (PS 101) with carbon dioxide (CO2), polystyrene (PS685D) with CO 2 and nitrogen (N2), and linear polypropylene (PP) (HE351F) and branched PP (WB130HMS) with CO2 and N2. The results showed that gas content and pressure-drop rate were the two most significant factors governing bubble formation and growth during foaming processes. Moreover, the foaming temperature and branching of the polymer had some effects on maximum cell density. Nucleating agent (talc) played a significant role under processing conditions with a low gas content and low pressure-drop rate, but it did not show any obvious effect at high gas content and high pressure-drop rate. Under the same initial foaming condition, the maximum cell densities of PS685D/CO 2 and PP/CO2 foams were higher than those of PS685D/N 2 and PP/N2 foams, respectively; while the maximum cell density of PS685D/CO2 and PP/CO2 foams were lower than those of PS685D/N2 and PP/N2 foams, respectively, if the same mole number of gas in unit polymer was used. In addition, experimental results show that branched PP foamed with N2 generated slightly higher cell density than linear PP, while linear PP foamed with CO2 generated slightly higher cell density than branched PP under the same initial saturation condition.
A fitting discipline: Fat subjects, femininity and the university

This thesis demonstrates how university institutions construct and perpetuate normative discourses of the body through the exclusion and denial of fat women. Universities are important sites for the production of truth and within these institutions particular bodies and subjects are normalized. This project focuses on two southern Ontario universities and is informed by a feminist poststructuralist perspective that understands the body as having numerous socially constructed meanings ascribed to it. I conducted three semi-structured interviews and one focus group and analyzed the experiences of six, self-identified plus-sized women who attend university. Their experiences and reflections reveal how normative bodies are validated and fat bodies are regulated and excluded through numerous disciplinary regimes and practices.

Keywords: Overweight women, Social conditions
Overweight women, Ontario
Obesity in women, Social aspects
Obesity in women, Ontario
Women college students, Social conditions
Women college students, Ontario
Femininity
Development of fine-celled bio-fiber composite foams using physical blowing agents and nano-particles

As one of eco-friendly bio-fibers, wood-fiber has been incorporated in plastics to make wood-fiber/plastic composites (WPC) with an increased stiffness, durability and lowered cost. However, these improvements are usually accompanied by loss in the ductility and impact strength of the composites. These shortcomings can be significantly improved by incorporating a fine-cell foam structure in the composites. This thesis presents the development of the foaming technology for the manufacture of fine-cell WPC foams with environmentally benign physical blowing agents (PBAs), and focuses on the elucidation of the fundamental foaming mechanisms and the related issues involved. One critical issue comes from the volatiles evolved from the wood-fiber during high temperature processing. The volatiles, as a blowing agent, can contribute to the foaming process. However, they lead to gross deterioration of the cell structure of WPC foams. The presence of volatiles makes foaming of WPC "a poorly understood black art". With the use of PBAs, a strategy of lowering processing temperature becomes feasible, to suppress the generation of volatiles. A series of PBA-based experiments were designed using a statistical design of experiments (DOE) technique, and were performed to establish the relationship of processing and material variables with the structure of WPC foams. Fundamental foaming behaviors for two different PBAs and two different polymer systems were identified. WPC foams with a fine-cell morphology and a desired density were successfully obtained at the optimized conditions. Another limitation for the wider application of WPC is their flammability. Innovative use of a small amount of nano-clay in WPC significantly improved the flame-retarding property of WPC, and the key issue was to achieve a high degree of exfoliation of nano-particles in the polymer matrix, to achieve a desired flammability reduction. The synergistic effects of nano-particles in foaming of WPC were identified as well.
A new theory for symmetric laminated plates

A new approach to plate theory is implemented and evaluated for accuracy. Unlike most formulations based on initial assumptions of a polynomial shape for the though-thickness distribution of displacements, the only hypothesis is the following: well-chosen elementary loads are identified as a basis of the ‘load space’. Hence, any load can be expressed as a linear combination of these Fundamental Loads. Therefore, the three dimensional solution is approximated as a combination of the through thickness solutions (Fundamental States) corresponding to these Fundamental Loads. This yields an internally consistent formulation, with newly defined degrees of freedom. The intent of this thesis work is to prove this concept for the case of the plate, as a previous study on the equivalent beam theory gave excellent results. For this purpose, the scope is restricted to the Second Approximation : Only the first two Fundamental States, pure bending moment and pure shear resultants, are used to approximate the solution state. This is therefore equivalent to a shear deformation theory, like the Reissner-Mindlin plate formulation. Comparison to Reissner-Mindlin results, and to full three dimensional (3D) results for a sandwich panel under different loading conditions, shows the capability of this new theory to accurately capture the three dimensional distribution of stresses and strains, especially the transverse shear components.

Keywords: Plates (Engineering)
Laminated materials
Understanding analysts' reactions to earnings management: Evidence from forecast revisions

This thesis examines the determinants of analysts' reactions to firms' earnings management. I present a model showing that analysts revise their forecasts according to their forecast errors revealed by earnings announcements and reporting biases embedded in reported earnings. The model further demonstrates that the relationship between forecast revisions and reporting biases can be affected by analysts' forecasting ability, the inherent uncertainty of whether reporting biases have occurred, as well as analysts' incentives. To empirically test the model's prediction regarding analysts' forecasting ability, I use analysts' firm-specific experience, size of their brokerage firm, and the number of industries they follow as proxies. Consistent with the model's prediction, I provide evidence showing that well-experienced analysts adjust more for earnings management while analysts following a greater number of industries adjust less for earnings management. Sensitivity analysis using analyst's historical firm-specific forecast accuracy as an alternative measure of forecasting ability further supports the hypothesis that analysts with better forecasting ability adjust more for earnings management. Moreover, analysts adjust less for earnings management when the inherent uncertainty of the reporting bias is greater. Specifically, analysts adjust less for earnings management when: (1) the past volatility of discretionary accruals is high; and (2) the firm has a marked propensity to smooth earnings. There is little evidence that affiliated analysts adjust less for earnings management than unaffiliated analysts. However, analysts adjust more for earnings management in the post-Reg FD period than in the pre-Reg FD period, which is consistent with Regulation FD achieving its objective of strengthening analysts' incentives to issue unbiased forecasts.
Comparing top-k algorithms in summary-based XML retrieval

The semi-structural feature of XML raises the challenge in XML Information Retrieval (XML-IR)---how to efficiently exploit the additional structural information. In this thesis, strategies for XML-IR are studied, with particular emphasis on strategies for top-k computations. Structural summaries are exploited for efficiently evaluating structural constraints in the query. For top-k computations, both a straightforward Merge Algorithm (MA) and a baseline Threshold Algorithm (TA) are implemented. In order to obtain the pre-computed scores for the relevant elements that are required as input by the top-k computation algorithms, an Exhaustive Retrieval Algorithm (ERA) is implemented. Experiments are conducted with an XML-IR system named TReX using NEXI queries over IEEE Journal and Wikipedia XML collections. The running times of the ERA, TA and MA algorithms are reported and compared. The experimental results show that neither TA nor MA outperforms the other for all queries.
Sites and roles of arrestin phosphorylation in regulating interactions between arrestin and rhodopsin of squid eyes

In squid (Loligo pealei), activation of phototransduction is mediated by rhodopsin isomerization to metarhodopsin and the activation of a phospholipase C pathway, resulting in depolarization of the retinal membrane. Inactivation is mediated by squid rhodopsin kinase (SQRK) and arrestin. Arrestin binding to metarhodopsin is the key inactivation step and SQRK-mediated phosphorylation of rhodopsin is not required for arrestin binding. SQRK can also phosphorylate arrestin, a function that is not shared by other receptor kinases. To determine the site(s) and function of arrestin phosphorylation, I expressed recombinant arrestins in E. coli and used site-directed mutagenesis. Squid arrestin was phosphorylated at Ser392 and/or Ser 397 by SQRK. Arrestin phosphorylation did not affect arrestin binding to rhodopsin in the light but inhibited its binding to dark-adapted membranes. Furthermore, the phosphorylation significantly increased arrestin dissociation from dark-adapted membranes at high salt concentrations in vitro. This work suggested that the role of arrestin phosphorylation was to increase dissociation of the protein from rhodopsin once it has been photoconverted back to inactive state.
Self-calibrated high-speed A/D converters: Analysis and design

This thesis introduces, for the first time, a system-level adaptive “filtering” technique for on-line self-calibration of high-speed AID converters. The technique is found to be very helpful in improving the conventional design of the AID converters towards higher speed, lower power and smaller device size. The self-calibration technique involves several new concepts developed in this research, originating from current-trimming (or tuning) a differential-pair balanced comparator. The self-trimming algorithm, which is Δ-modulation (ΔM) based, constitutes a major element of the technique. The adaptive “filtering” effect of this algorithm over an array of comparators in a flash A/D converter is realized by ΔM windowing of these successive comparators. The effect is analyzed mathematically by a two-dimensional Z-transform to reveal its convergence. The combination of this algorithm with the traditional digital error correction technique gives a complete self-calibration scheme for correcting errors in all the major components of high-speed A/D converters. Architectures and novel circuits are proposed and developed for the realization of the self-calibration technique in 2-stage subranging, pipelined multi-stage and oversampling multi-bit ΣΔ A/D converters. Simulation at a behavioral level for a 10-bit 2-stage subranging A/D converter, and a 10-bit pipelined 9-stage A/D converter is performed with both random processes and discrete real video signal as inputs to examine the superior efficiency of the technique and the simplicity of the corresponding circuitry. The technique can be readily extended to oversampling multi-bit ΣΔ A/D converters with a significant reduction in control circuitry. The ideas introduced in this research are based on techniques scattered over areas of solid-state circuits, circuits & systems, communication, system control and digital signal processing.
Working memory and academic achievement in college students with attention-deficit/hyperactivity disorder

This study examined working memory (WM), academic functioning and their relationship, in university/college students with previously diagnosed ADHD. Students with ADHD (N=16) and Normal Control students (N=30) were recruited. Participants completed three auditory-verbal WM measures, two visual spatial WM measures and one control executive function task. Also, they self-reported grade point averages (GPA) based on university/college courses. We found that the ADHD group displayed significant weaknesses on auditory-verbal WM tasks and one visual spatial task. They also showed a non-significant trend for lower GPA. Within the entire sample, there was a significant relationship between GPA and auditory-verbal WM. Based on these findings, young adults with ADHD who are attending university or college continue to demonstrate moderate WM impairments. Since WM abilities are linked with academic attainment, these students are at risk. Parents, physicians and educators should advise university/college-bound students with ADHD to contact accessibility services for academic guidance.
The association between Canadian folic acid flour fortification and the incidence rate of early childhood cancers

The objective of this population-based, cross-sectional cohort study was to examine incidence rates of acute lymphoblastic leukemia (ALL), brain cancers (BC) embryonal cancers (EC) and Wilms' tumor (WT) in Ontario children aged 0-4 and 5-9 before and after folic acid (FA) fortification of flour. Cases were indentified using the Pediatric Oncology Group of Ontario's cancer registry. Time series analysis demonstrated that in both age groups, there were no differences in the incidence of ALL, BT and EC after FA fortification. The incidence of WT significantly decreased in the 0-4 age group from 1.94 per 100 000 before fortification to 1.43 per 100 000 after fortification (p=0.019), which corresponded to a 30% reduction. Ontario is unique because it is the only region with FA fortification and a network of pediatric oncology centres submitting to a central database. The results suggest that FA fortification was associated with a 30% reduction in WT.
An evaluation of U.S. and Canadian lignocellulosic biomass supply and ethanol production costs

Cellulosic biofuels are an attractive renewable fuel option. An improved understanding of lignocellulosic biomass resource availability and the expected cost of biofuel production can facilitate the development of appropriate renewable fuel policies and targets. Fifteen studies estimating lignocellulosic biomass availability for the U.S. and Canada were compared. Considerable differences in reported biomass estimates were found, largely due to different assumptions about crop yields, land area availability, and the inclusion of economic considerations. In the near-term, the largest biomass categories for the U.S. and Canada are predicted to be agricultural residues and logging residues, respectively. Near-term cellulosic ethanol production costs were reviewed and compared using a standardized methodology. The largest components of ethanol production cost are feedstock costs and capital investment and recovery costs. Further technological progress and associated cost reductions were found to be needed prior to the commercialization of biochemical conversion processes for producing ethanol.