VictorJuiz/thesis huggingface dataset:
Analytical and Numerical Modeling of Fluid Flow and Heat Transfer through Open-cell Metal Foam Heat Exchangers
Keywords: Computational Fluid Dynamics
Fluid Flow
Heat Exchnager
Heat Transfer
Metal Foam
Numerical Modeling

In this thesis analytical and numerical investigations of fluid flow and heat transfer through open cell metal foam heat exchangers are presented. Primarily, different representative unit cell approximations, i.e, tetrakaidecahedron, dodecahedron and cubic are discussed. By applying the thermal resistance analogy, a novel formulation for evaluation of the effective thermal conductivity of metal foams is proposed. The model improves previous models based on cubic or hexagonal cells. By using computer tomography images of a nickel foam sample a realistic 3D geometry is created and the foam's geometrical properties (i.e., porosity and surface area to volume ratio) and effective thermal conductivity are obtained. By using the experimentally found values of permeability, Forchheimer coefficient and solid-fluid interfacial convection coefficient, mathematical models for fluid flow and heat transfer in metal foams are developed. Two different assumptions: local thermal equilibrium (LTE) and local thermal non-equilibrium (LTNE), are used. LTNE yields more accurate results. A three-dimensional computational fluid dynamics (CFD) model of a metal foam is made and validated against the experimental data for a square cross sectional nickel foam heat exchanger channel heated from the side walls while cooling air passes through the foam. The simulations are carried out for constant temperature or heat flux and different foam materials with pore densities of 10 and 40 pores per inch. The results show that the bonding of the foam to the walls has a considerable impact on the heat transfer rate. Convective heat transfer coefficients in terms of Nusselt number as functions of Reynolds number are also obtained. The design and CFD modeling of metal foam cross flow heat exchangers are also discussed. The results indicate both effectiveness and number of transfer units (NTU) for the metal foam heat exchangers are higher than those of a hollow channel, however, the effectiveness-NTU curves are identical. The design and simulation of a metal foam heat shield for high temperature applications are presented. By locating the regions with maximum temperatures, through the CFD simulations, the design of the heat shield is optimized for both water-cooled and air-cooled models.
Role of Water in the Formation, Transformation and Fate of Secondary Organic Aerosol
Keywords: Cloud Condensation Nuclei
Particle Water
Secondary Organic Aerosol

Particle-phase water is the most abundant atmospheric aerosol constituent, yet the importance of water for the formation, transformation and fate of secondary organic aerosol (SOA) remains not fully characterized. In order to address this knowledge gap, this thesis explores the role of water in SOA formation, chemical aging and fate as cloud condensation nuclei. The formation of SOA from the photooxidation of isoprene in the presence of various sulfate seed particles was investigated using a flow tube reactor. Under constant environmental conditions, particle-phase water was found to have the largest effect on the amount of SOA formed where this additional organic material was highly oxidized, likely arising from enhanced uptake of organic acids due to their high water solubility. The amount of high molecular weight compounds increases with acidity, suggesting the role of acidity in governing organic composition. The relative humidity (RH) dependence of SOA aging by photolysis was examined using particles containing water-soluble α-pinene SOA material in an environmental chamber at three RH conditions (5, 45 and 85 %). Photolysis led to substantial mass loss where the rate of mass loss increased with increasing RH, suggesting that moisture-induced changes in SOA phase have implications to particle reactivity. Aging of ambient SOA sampled at Whistler, British Columbia found that aging by both gas and aqueous-phase OH increased the degree of oxygenation and CCN activity of the organic material, confirming the hypothesis that there is a simple relationship between the hygroscopicity of organic aerosol and its oxygen-to-carbon ratio. Addition of various types of organic material onto sulfate particles resulted in the suppression of water uptake during droplet growth. Experiments using sulfate particles with different acidity suggest that high molecular weight compounds, formed via acid-catalyzed condensed phase reactions, are the species affecting water uptake kinetics.
Searching for the Social: Corporate Social Responsibility and Economic Regulation Beyond the State
Keywords: Corporate Citizenship
Corporate Social Responsibility
Globalization
Governmentality
Regulation
Social

The politics of "corporate social responsibility" (CSR) have been suggested as a way to help respond to some of the governance gaps caused by globalization. However, CSR struggles with the question of how critical it can be, and particularly whether it can condemn market agents as subjectively antisocial. CSR is thus perpetually caught between critics on the right who dismiss its real-world seriousness, and critics on the left who worry about its co-optation by the imperatives of business. Both camps suggest that focusing on workplace subjectivity is irrelevant and distracting. Meanwhile, "on the ground", activists plainly do just that. The question is what is lost, in terms of effective governance, when we deny that it is useful to challenge organizational personas and managerial subjectivities. To assess this, I deploy a governmentality analysis to pick apart how CSR politics typically weave together two distinct ways of thinking about regulation. These two "political rationalities" facilitate different discursive framing techniques and different political practices. I argue that CSR's more critical politics often flow from what Foucauldian scholars call "the social" or "social government". "Social government" champions a sense of our interdependence, and often targets the subjectivities of market agents as a way to extra-legally address market abuses. However, theorists have been lamenting the decline of "the social" for decades. What explains the continuing vitality of these supposedly irrelevant politics? I show that recent critical manifestations of CSR politics draw from under-theorized non-state modes of "the social", and are hybridized to fit an increasingly marketized world. These "social" politics can help us build theory about CSR phenomena, as these politics draw much of their normative power from implicit critiques of managerial subjectivities, and reflect only ephemerally any supposed social rules.
The Centrality of Cognitively Diagnostic Assessment for Advancing Secondary School ESL Students' Writing: A Mixed Methods Study
Keywords: Assessment
Diagnostic Assessment
Feedback
Mixed Methods
Secondary School Students
Second Language Writing

The primary purpose of this investigation was to examine the effects of cognitively diagnostic feedback (CDF) on secondary school English as a second language (ESL) students' writing development using a validity framework. CDF is information that is generated by diagnosing gaps in learners' cognitive processing and strategy use in a specific domain, to guide learners towards desired goals. A diagnostic rubric for assessing writing (DRAW) was developed through an iterative process involving teachers and students, founded in both theory and curriculum, and used to generate CDF. Key validity assumptions were identified related to the use of DRAW in secondary school classrooms. These assumptions were used to generate inquiry questions that guided the investigation addressing the diagnostic potential of DRAW, the effect of students' perceptions of DRAW feedback on their writing development, the interaction between students' perceptions of DRAW feedback and their goal orientations, anxiety, and self-efficacy, and the influence of teachers on students' use of feedback. Using a mixed methods research design, evidence was gathered from three Grade 10 classrooms comprising a total of 52 ESL learners and their teachers. DRAW was used to generate CDF providing students with strengths and areas for improvement on their ideas, vocabulary, grammar, organization, mechanics, and sentence fluency. Students' perceived understanding, reflection, perceived usefulness, and intent for future use of the CDF were measured through a survey and structured interviews. Students' use of the CDF was evaluated across writing samples at multiple times, and examined in relation to their goal orientations, writing anxiety and self-efficacy. Teachers' use of DRAW was also evaluated through observations and interviews. Multiple sources of evidence were used to warrant claims about DRAW practice: 1) DRAW provided cognitively, diagnostically rich information about adolescent students' writing compared to competing feedback sources used in these classrooms; 2) Students' perceptions of DRAW feedback varied according to self-efficacy, writing anxiety, and goal orientations; 3) DRAW feedback had a positive effect on students' writing skill development; 4) Teachers' assessment beliefs and feedback practices influenced and shaped students' perceptions and use of feedback and contributed to their writing performance; and 5) Teachers valued DRAW.
The Behaviour of Reinforced Concrete Subjected to Reversed Cyclic Shear
Keywords: Cracks
Hysteresis
Reinforced concrete
Reversed cyclic
Shear

Reversed cyclic loading, as may occur during seismic events, can cause sudden and brittle shear failures in reinforced concrete structural members. This thesis presents both experimental and analytical investigations into the behaviour of members subjected to reversed cyclic shear loading, and culminates in the development of a new, rational model to describe this behaviour. In the experimental phase of the research, ten reinforced concrete shell elements were tested under reversed cyclic in-plane shear loads. Data collected by means of several acquisition systems allowed extensive analysis of the experiments, and provided insight into the behaviour of the crack interfaces. In comparison with existing models, such as the Modified Compression Field Theory, it was found that the shear strengths of these reversed cyclically loaded specimens were as much as 25% lower than monotonic predictions. The results of the experimental program informed the development of a new analytical model, the General Crack Component Model (GCCM). The central concept of the GCCM is that the reversed cyclic behaviour of a shear panel depends on the behaviour of multiple crack systems, each with its own constitutive properties. A rigorous framework based on the principles of compatibility and equilibrium was formulated in order to allow for the appropriate combination of the stiffnesses of the three components of the model: concrete, steel, and cracks. The GCCM was validated for reversed cyclic and monotonic loading by comparison with the experimental results as well as data from other researchers. It was shown that the model provides good estimates of the behaviour of reinforced concrete subjected to reversed cyclic loads, and that it can be used as part of a larger structural analysis, ultimately helping engineers to design safer structures and more accurately assess the safety of existing construction.
A Phenomic Assessment of Subcellular Morphology in Saccharomyces cerevisiae Using Synthetic Genetic Array Analysis and High-content Screening
Keywords: functional genomics
microscopy
network
phenomics
Saccharomyces cerevisiae

In this thesis, I describe the optimization and adaptation of an integrated SGA-HCS pipeline complete with a robust panel of downstream statistical metrics, to analyze subcellular phenotypes in yeast cells in the context of the yeast deletion collection (Giaever et al., 2002a; Winzeler, 1999) and the ts collection of essential gene mutants (Li et al., 2011a). I have used this experimental pipeline to closely examine the utility of both single and double mutant screening strategies for the identification of subtle subcellular phenotypes, with a special focus on the formation of DNA damage foci, and have subsequently characterized Vid22, a protein with a previously unappreciated role in the DNA damage response. I have additionally endeavored to curate known cellular and subcellular mutant morphologies into a database, using a systematic rhetoric to describe conditions and observable phenotypes in order to provide a resource and gold standard set of mutants with which to assess ongoing Marker Project screens.
Thought Experiments in Science
Keywords: Cognitive Science
Epistemology
History of Science
Philosophy of Science
Thought Experiments
Understanding

Thought experiments are a means of imaginative reasoning with an employment record longer than two and a half thousand years. Used by Aristotle, Galileo, Newton, Darwin, Maxwell, and Einstein, they form part of the education of every scientist alive today. While most scientific instruments aim to increase the precision of our interaction with empirical data, thought experiments leave the empirical realm behind. They spin buckets in an empty universe, summon demons to play with particles, and challenge us to throw spears at the edge of space. If tools of the imagination like thought experiments are important in science, what role are they playing? Using the methods of history, philosophy and cognitive science, I argue that while thought experiments do not always discover or justify new facts, they do usually increase the empirical content of theoretical structures (laws, models, concepts, etc.) for an agent. Empirical content is increased when the agent connects a theoretical structure to existing concepts, experiences, values and abilities. Through these connections, thought experiments increase scientific understanding. Knowledge can be produced when understanding is applied, but this is a separate achievement. I argue that the understanding produced by thought experiments is fallible but necessary for scientific progress, in the same way that intuitions about what a speaker means are fallible but necessary for linguistic interpretation. Chapter 1 introduces the philosophical literature on thought experiments. Chapters 2-4 reject two important accounts of thought experiments. Chapter 5 examines historical cases to focus on the role of thought experiments in science. Chapter 6 considers results in cognitive and social science. Chapter 7 presents a transcendental argument that grounds our ability to increase empirical content through thought experiments in human imagination, and explores some implications of this argument for the relationships among imagination, understanding, explanation, knowledge, representation and objectivity.
Rate-determining Processes in Acid-catalyzed Decarboxylation Reactions
Keywords: acid catalysis
carbon kinetic isotope effects
decarboxylation
indole-carboxylic acid
pyrrole-carboxylic acid

The acid-catalyzed decarboxylation reactions of indole- and pyrrole-carboxylic acids require the addition of one equivalent of water to the carboxyl group and a proton to the heterocyclic ring carbon at the position α to the carboxyl. Where α-protonation is thermodynamically favoured over β-protonation, the magnitude of the observed 12C/13C kinetic isotope effect (CKIE) is greater than where the β-position is protonated. This can be understood in terms of a mechanism involving a protonated hydrated precursor to carbon-carbon bond cleavage, where the difference in energy of intermediates and transition states control the proportioning of the intermediates. The intrinsic CKIE on the carbon-carbon bond-breaking step that produces protonated carbonic acid (PCA) is independent of the site of protonation. The interpretation of the observed CKIEs can be generalized based on intermediates from isomeric carboxylic acids whose energetics vary predictably with their sites of protonation. The relative free energy barriers to reversion and formation of PCA control the magnitude of the observed CKIEs and correlate with reactivity. The reported data implicate the formation of PCA as the initial product of carbon-carbon bond cleavage. Application of the principle of microscopic reversibility implies that electrophilic aromatic substitution based on PCA should be an accessible route to carboxylation of aromatic substrates. Over the course of the project, new methods were developed for the simultaneous pressure detection and mass spectral analysis of carbon dioxide released as a final product. Specifically, headspace gas analysis and compound-specific isotope analysis of carbon dioxide have been coupled as a result. The evaluation for new decarboxylation mechanisms in general has led to a clearer understanding of how the intervention of hydrated intermediates leads to formation of PCA and its subsequent rapid conversion to carbon dioxide.
Managing Conflict of Interest in Healthcare: The Roles of Professionalism and Regulatory Colleges
Keywords: conflict of interest
professionalism
regulatory colleges
self-regulated health professions

Self-regulation relies on professionalism, which entails the existence of a specialized body of knowledge, associated activities best evaluated by those possessing this knowledge, the expectation that professionals act on behalf of their clients, and the potential for harm if the activities are not carried out well (Bayles 1986; Cruess Cruess, 1997; Freidson 1994, 2001). A conflict of interest (COI) occurs when conditions may unduly influence an individual's behavior or ability to carry out his/her obligations (Thompson, 1993; Carson, 1994). In healthcare, COI may interfere with patient care, and erode trust, undermining self-regulation's effectiveness (Thompson, 1993; Cruess, Johnston and Cruess, 2002; Tonelli, 2007; Haines Olver, 2008). This study examined how four Ontario-based regulatory Colleges addressed financial COI. Incorporating a nested multiple-case study, part one, a descriptive study examined which health professions were self-regulated in Canada. Part two, a multiple-case study examined four health professions' Colleges in Ontario regulating: Audiologists and Speech-Language Pathologists; Nurses; Physiotherapists; and Physicians. Part one's results indicated differences amongst the provinces regarding legislative framework implementing self-regulation, and which health professions were granted self-regulation. Part two's results indicated that the four Colleges had mechanisms in place to address financial COI, although the number of disciplinary hearings that related to financial COI was low, suggesting the number or importance of financially-based COI issues within these Colleges was low. It was also reflective of the disciplinary process which largely relies on complaints or concerns being submitted to the College. The areas these Colleges perceived their members to have COI concerns could be related back to nature of work, work environment and remuneration. The Colleges viewed publicly-funded services as minimizing the risk for financial COI. The Colleges did not have oversight in determining fees, and pricing under any remuneration structure, nor did their mandates extend to non-professionally owned/managed businesses. Areas identified for further investigation to inform policy development included examining how accountability is maintained in areas related to financial COI for publicly-funded services. In addition, how Colleges might play a role in maintaining public interest and trust as profession-controlled markets are moving towards corporately-owned or controlled models warrants further study.
Size Matters: Developing Design Rules to Engineer Nanoparticles for Solid Tumour Targeting
Keywords: Active Targeting
Cancer
Nanoparticle
Skin
Tumour Size
Tumour Targeting

Nanotechnology enables the design of highly customizable platforms for producing minimally invasive and programmable strategies for cancer diagnosis and treatment. Advances in this field have demonstrated that nanoparticles can enhance specificity of anti-cancer agents, respond to tumour-specific cues, and direct the visualization of biological targets in vivo. Nanoparticles can be synthesized within the 1 to 100 nm range to achieve different electromagnetic properties and specifically interact with biological tissues by tuning their size, shape, and surface chemistry. However, it remains unclear which physicochemical parameters are critical for delivering nanomaterials to the tumour site. With less than 5% of administered nanoparticles reaching the tumour, engineering of nanoparticles for effective delivery to solid tumours remains a critical challenge to cancer nanomedicine. A more comprehensive understanding of the interplay between the nanomaterial physicochemical properties and biological systems is necessary to enhance the efficacy of nanoparticle tumour targeting. This thesis explores how nanoparticle size and functionalization with cancer cell specific agents impact nanoparticle delivery to tumours. Furthermore, this doctoral work (i) discusses how tumour structure evolves with growth, (ii) elucidates how such changes modulate nanoparticle accumulation, and (iii) identifies how the skin serves as a significant off-target site for nanoparticle uptake. This thesis also demonstrates the utility of empirically-derived parametric models, Monte Carlo simulations, and decision matrices for mechanistically understanding and predicting the impact of nanomaterial features and tumour biology on nanoparticle fate in vivo. These topics establish key design considerations to tailor nanoparticles for enhanced tumour targeting. Collectively, the concepts presented herein form a fundamental framework for the development of personalized nanomedicine and nano-diagnostic agents in the future.
The Effect of Anaerobic Treatment of Pulp Mill Effluents on Reactor Performance and Granular Sludge
Keywords: Anaerobic Treatment
Biogas Production
Granulation
Pulp mill effluents
Pyrosequencing

Pulp mill wastewaters contain high concentrations of organic compounds that can be partially converted into methane. Granulation of sludge is the key to successful treatment of pulp mill effluents in high rate anaerobic reactors. This research focused on the anaerobic treatment of a high strength pulp mill alkaline effluent from sulphite pulping (AE) of softwood chips, which was characterized by rich COD content and relatively high concentrations of resin acids and long-chain fatty acids (RFAs) known to be compounds inhibitory to methanogens. Two continuous reactor experiments were conducted to study the treatment of this softwood AE. In the first experiment, different concentrations of AE were treated for one month in four reactors. In the second experiment, increasing loadings of AE were added to the test reactor over a nine-month period. The negative impact of the addition of AE on reactor performance and granulation was confirmed, shown as poorer organic removals, lower biogas production, and smaller and weaker granules in the AE sludge. Larger amounts of RFAs (>50mg RFAs / g TSS sludge) were found to associate with the sludge solids receiving a high AE loading, with palmitic acid being the most dominant RFA. RFA loadings were found to be significantly negatively correlated to the biogas production. Therefore, RFAs were proposed to play an important role in the negative impact of AE. Microbial community analysis using pyrotag sequencing of amplified 16S rRNA genes from various samples collected from the two studies revealed that the communities of the sludge treating AE were very different than those of the AE-free sludge. In terms of the organisms affected by the addition of AE, Oscillospira was significantly positively correlated to AE loadings. The sludge treating AE also contained significantly lower percentages of methanogens. Furthermore, no clear sign of sludge acclimating to AE with enhanced biogas production was found. It is recommended that AE should be pretreated to reduce its toxic effect and to achieve greater COD removals toward higher biogas production.