VictorJuiz/thesis huggingface dataset:
Modelling Detailed-chemistry Effects on Turbulent Diffusion Flames using a Parallel Solution-adaptive Scheme

Capturing the effects of detailed-chemistry on turbulent combustion processes is a central challenge faced by the numerical combustion community. However, the inherent complexity and non-linear nature of both turbulence and chemistry require that combustion models rely heavily on engineering approximations to remain computationally tractable. This thesis proposes a computationally efficient algorithm for modelling detailed-chemistry effects in turbulent diffusion flames and numerically predicting the associated flame properties. The cornerstone of this combustion modelling tool is the use of parallel Adaptive Mesh Refinement (AMR) scheme with the recently proposed Flame Prolongation of Intrinsic low-dimensional manifold (FPI) tabulated-chemistry approach for modelling complex chemistry. The effect of turbulence on the mean chemistry is incorporated using a Presumed Conditional Moment (PCM) approach based on a beta-probability density function (PDF). The two-equation k-w turbulence model is used for modelling the effects of the unresolved turbulence on the mean flow field. The finite-rate of methane-air combustion is represented here by using the GRI-Mech 3.0 scheme. This detailed mechanism is used to build the FPI tables. A state of the art numerical scheme based on a parallel block-based solution-adaptive algorithm has been developed to solve the Favre-averaged Navier-Stokes (FANS) and other governing partial-differential equations using a second-order accurate, fully-coupled finite-volume formulation on body-fitted, multi-block, quadrilateral/hexahedral mesh for two-dimensional and three-dimensional flow geometries, respectively. A standard fourth-order Runge-Kutta time-marching scheme is used for time-accurate temporal discretizations. Numerical predictions of three different diffusion flames configurations are considered in the present work: a laminar counter-flow flame; a laminar co-flow diffusion flame; and a Sydney bluff-body turbulent reacting flow. Comparisons are made between the predicted results of the present FPI scheme and Steady Laminar Flamelet Model (SLFM) approach for diffusion flames. The effects of grid resolution on the predicted overall flame solutions are also assessed. Other non-reacting flows have also been considered to further validate other aspects of the numerical scheme. The present schemes predict results which are in good agreement with published experimental results and reduces the computational cost involved in modelling turbulent diffusion flames significantly, both in terms of storage and processing time.

Keywords: Computational Fluid Dynamics
Computational Combustion
Advisor: Groth, Clinton P. T.
Disabled Young People, Support and the Dialogical Work of Accomplishing Citizenship

Governments, human rights bodies and disability studies scholars all have suggested that disabled people’s citizenship – the legal status and lived practices that enable membership, participation and belonging in one’s community - depends on consistent, adequate and readily available home and personal supports. Yet, little theoretical or empirical work examines disabled young people’s citizenship or their use of support, particularly from their standpoints. Consequently, the ‘work’ disabled young people do to accomplish citizenship remains unrecognized, as are their unique requirements for support to do that work. Normative non-disabled citizenship assumptions remain unproblematized. This study explores what disabled young people do to accomplish citizenship, using home and personal support as the empirical foci. I used a dialogic theoretical and methodological approach, drawing on Mikhail Bakhtin and Dorothy Smith. Both posit that our talk, consciousness and actions respond to and anticipate the voices of others. Through participatory media arts techniques with disabled young people, ethnographic observation and interviews with gatekeepers to formal and informal care, I describe the work that a group of disabled young people did to secure and maintain support and how this in turn shaped their opportunities for specific citizenship practices: self-determination, community participation and social contribution. I argue that disabled young people's work to secure and maintain support requires that they mobilize the authoritative discourse of 'the poster child': a set of objectified values and views encapsulated in utterances about disabled people as futureless, deficient and deferential, originating in images to promote charitable giving. I trace three sequences of activities in which participants assimilated, resisted or brought poster child utterances into ‘dialogue’. The findings raise questions about the extent to which formal entitlements to supports influence how citizenship is lived. Drawing attention to the gaps and tensions in support provision, the findings illuminate the tremendous invisible, tacit work these participants do to strengthen fragile supports. This work, organized by philanthropic rather than rights discourses, leads to a qualified or fragile citizenship. Finally, the study raises questions about the normative and material demands that we may all experience with respect to achieving citizenship, regardless of disability or age.

Keywords: Disability
Citizenship
Advisor: Eakin, Joan
Theory and Applications of Microstrip/Negative-refractive-index Transmission Line (MS/NRI-TL) Coupled-line Couplers

The electromagnetic coupling of a microstrip transmission line (MS-TL) to a metamaterial backward wave Negative-Refractive-Index transmission line (NRI-TL) is the primary investigation of this dissertation. The coupling of forward waves in the MS-TL to the backward waves in the NRI-TL results in the formation of complex modes, characterized by simultaneous phase progression and attenuation along the lossless lines. Through network-theoretic considerations, we investigate the properties of these modes in the complex-frequency plane of the Laplace domain to help unravel the confusion that has existed in the literature regarding the independent excitation of a pair of conjugate complex modes. We show that it is possible to arbitrarily suppress one of the modes over a finite bandwidth and completely eliminate it at a discrete set of frequencies using proper source and load impedances. Hence we use conjugate modes with independent amplitudes in our eigenmode expansion when we analyse various coupling configurations between the two types of lines (MS/NRI-TL coupler). We derive approximate closed-form expression for the scattering parameters of the MS/NRI-TL coupler and these are complemented by design charts that allow the synthesis of a wide range of specifications. Moreover, these expressions reveal that such couplers allow for arbitrary backward coupling levels along with very high-isolation when they are made half a guided wavelength long. The MS/NRI-TL coupler offers some interesting applications which we highlight through the design and testing of a 3-dB power splitter, a high-directivity signal monitor and a compact corporate power divider. We have included design, simulation and experimental data for the fabricated prototypes exhibiting good agreement and thereby justifying the theory that has been developed in this work to explain the coupling between a right-handed MS-TL and a left-handed NRI-TL.

Keywords: RF/Microwave Coupler
Complex modes
Metamaterials
Coupled-mode theory
MS/NRI-TL coupler
Multi-conductor transmission lines
Right-half-plane branch-points
Coupling between forward and backward waves
Network theory of coupling
Independent excitation of complex modes
Backward waves
Negative group delay
High directivity coupler
Advisor: Eleftheriades, George V.
Patterns, Determinants, and Spatial Analysis of Health Service Utilization following the 2004 Tsunami in Thailand

On December 26th, 2004, 280,000 people lost their lives. A massive earthquake struck Indonesia, triggering a tsunami that affected several countries, including Thailand. The disaster had important implications for health status of Thai citizens, as well as health system planning, and thus underscores the need to study its long-term effect. This dissertation examined the patterns, determinants, and spatial analysis of health service utilization following the tsunami in Thailand. The primary aim was to determine whether tsunami-affected status (personal injury or property loss) and distance to a health facility (public health center or hospital) influenced health service utilization. The study population included Thai citizens (aged 14+), living in the tsunami-affected Thai provinces: Phuket, Phang Nga, Krabi, and Ranong. Study participants were randomly selected from the ‘affected’ and ‘unaffected’ populations. One and two years after the tsunami, participants were interviewed in-person on demographic and socio-economic factors, disaster impact, health status, and health service utilization. Five types of health services were examined: outpatient services, inpatient services, home visits, medications, and informal (unpaid) care. Distance to a health facility was calculated using Geographic Information System’s Network Analyst. The Grossman model of the demand for health care and a distance decay concept provided the foundation for this study. A propensity score method and a two-part model were used to examine the study objectives. There were 1,889 participants. One year after the tsunami, individuals affected by property loss were more likely to use medications than unaffected participants. Two years after the tsunami, individuals with personal injury were more likely to use outpatient services, medications, and informal care than unaffected participants. Distance to a health facility was associated with the use of medications and informal care. The results confirmed the long-term effect of a tsunami. This dissertation may assist the decision- and policy-makers in the identification of those most likely to use health services and in the request of health resources to the affected areas. The patterns, determinants, and spatial analysis of health service utilization found in this study may not be specific to a tsunami and may provide insights on post-disaster contexts of other natural disasters.

Keywords: Natural disaster
Tsunami
Distance to a health facility
Distance decay effect
Grossman model
Health service utilization
Two-part model
Propensity score method
Advisor: Coyte, Peter C.
Effect of Chemical Impurities on the Solid State Physics of Polyethylene

Computational quantum mechanics in the frame work of density functional theory (DFT) was used to investigate the effect of chemical impurities on high field conduction in polyethylene (PE). The impurity states in the band gap caused by common chemical impurities were characterized in terms of their “depth”, i.e. energy relative to their relevant band edge (valence band or conduction band), and in terms of the extent to which their wavefunctions were localized to a single polymer chain or extended across chains. It was found that impurity states can affect high field phenomena by providing “traps” for carriers, the depths of which were computed from first principle in agreement with estimates in literature. Since the square of the wavefunction is proportional to the spatial electron probability density, transfer of charge between chains requires wavefunctions which are extended across chains. Impurity states which are extended between chains can facilitate the inherently limited interchain charge transfer in PE, as the DFT study of iodine doped PE revealed. The introduction of iodine into PE increases conductivity by several orders of magnitude, increases hole mobility to a much greater extent than electron mobility, and decreases the activation energy of conduction from about 1 eV to about 0.8 eV. These characteristics were explained in terms of the impurity states introduced by iodine and wavefunctions of those states. Understanding the effect of iodine on conduction in PE provided a basis for understanding the effect of common chemical impurities on conduction therein. In particular, carbonyl and vinyl impurities create states which should promote hole mobility in a manner very similar to that caused by iodine. It was demonstrated that in the context of high field conduction in PE, besides the traditional focus on the depth of impurity states, it is important to study the spatial features of the states wavefunctions which are neither discussed nor accounted for in present models.

Keywords: Insulating Polymers
High Field Conduction
Chemical Impurities
Dielectrics
Polyethylene
Computational Quantum Mechanics
Density Functional Theory
Advisor: Boggs, Steven
Iravani, Mohammad Reza
Concussions in the National Hockey League (NHL): The Video Analysis Project

Hockey is a popular sport, and at its highest levels, it is a complex contact game characterized by physical strength, speed, and skill. The interaction of these characteristics contributes to the inherent risk of injury athletes must face while playing. Among hockey injuries, concussions are one of the most commonly sustained by athletes across all levels of play and age groups. Significant public attention, combined with poorly understood long-term effects, indicates the importance of tangible preventive strategies. The main goal of this thesis was to understand, through video analysis, how playing characteristics and mechanism of injury contribute to concussions in the National Hockey League (NHL). In the first study, the development and validation of an observational recording tool used to code and analyze NHL concussions observed via video analysis was described. The second study attempted to synthesize the description of players’ characteristics, antecedent events, and contextual variables associated with events leading to concussion at the NHL level. Several specific risk factors for concussion in NHL players were identified, including position, body size, specific locations on the ice, and particular situations based on a player's position. The final study systematically analyzed how concussions occur to identify potential pattern(s) of concussions. A common specific injury mechanism characterized by player-to-player contact and resulting in contact to the head by the shoulder, elbow, or gloves, was also identified. When the principal mechanism was refined further, several important characteristics were discernable: (i) contact was often to the lateral aspect of the head; (ii) the player who suffered a concussion was often not in possession of the puck; and (iii) no penalty was called on the play. Collectively, these studies served to address gaps in the literature; the implications for informing prevention and management strategies are also discussed.

Keywords: Concussion
National Hockey League
Injury Prevention
Video Analysis
Hockey
Sport
Advisor: Comper, Paul
Colantonio, Angela
A Methodological Framework for Decision-theoretic Adaptation of Software Interaction and Assistance

In order to facilitate software interaction and increase user satisfaction, various research efforts have tackled the problem of software customization by modeling the user’s goals, skills, and preferences. In this thesis, we focus on run-time solutions for adapting various interface and interaction aspects of software. From an intelligent agent’s perspective, the system views this customization problem as a decision-theoretic planning problem under uncertainty about the user. We propose a methodological framework for developing intelligent software interaction and assistance. This framework has been instantiated in various case studies which are reviewed in the thesis. Through efforts of data collection experiments to learn model parameters, simulation experiments to assess system feasibility and adaptivity, and usability testing to assess user receptiveness, our case studies show that our approach can effectively carry out customizations according to different user preferences and adapt to changing preferences over time.

Keywords: intelligent assistance
decision theory
software interaction
adaptive interfaces
Advisor: Boutilier, Craig
Transition Metal Catalysis: Construction of C–N and C–C bonds en route to Nitrogen Heterocycles, Chiral Esters and 6-deoxyerythronolide B

The Dong research group is interested in harnessing the power of transition metal catalysis to transform simple molecules and reagents (such as carbon monoxide, hydrogen gas, olefins, and C–H and C–O bonds) into valuable products (such as functionalized heterocycles, chiral carbonyl compounds and natural products). This thesis will describe our continual effort to achieve this goal. Part I describes the Pd-catalyzed functionalization of sp2 and sp3 C–H bonds. Carbon monoxide is used as a stoichiometric reductant in the cyclization of diarylnitroalkenes to afford biologically relevant 3-arylindoles and other N-containing heterocycles with carbon dioxide as the only stoichiometric byproduct. Also, an aryl sulfoxide moiety is shown to direct the arylation of sp3 C–H bonds to afford beta-functionalized amides. Part II describes the Ru-catalyzed sp3 C–O bond activation of alkoxypyridines and related heterocycles. In this transformation, an O- to N-alkyl migratory rearrangement occurs to afford N-alkylated pyridones which are structures found in many natural products and pharmaceutical agents. Part III describes our pursuit of metal-catalyzed asymmetric synthesis. Readily available benzylic bromides are carbonylated with carbon monoxide in alcoholic solvent mixtures. The resulting medicinally relevant 2-arylpropionic esters are obtained with moderate to good enantioselectivities. Preliminary results for the asymmetric hydrogenation of gem-diarylethylenes and novel ligand development are also disclosed. Part IV describes our efforts towards the total synthesis of 6-deoxyerythronolide B. Our retrosynthetic analysis of the macrolide antibiotic involves disconnections at the lactone linkage and between C7 and C8. The two equally complex fragments were prepared via reliable aldol, hydroboration, crotylation and redox chemistry. Rather than the typical macrolactonization method to form the 14-membered ring, we propose an alternative strategy where we plan to cyclize with a metal-catalyzed ring-closing metathesis event. Currently, this step is under investigation by other members in the group.

Keywords: transition metal catalysis
C–N and C–C bond formation
C–H bond fuctionalization
C–O bond activation
nitrogen heterocycles
carbonylation
total synthesis
6-deoxyerythronolide B
Advisor: Dong, Vy Maria
The Normativity of Nonstandard Emotions: An Essay on Poignancy and Sentimentality

This dissertation examines a particular quality of emotion experience that has received little attention in contemporary philosophical and psychological studies of the emotions. This is inversely proportional to the significant attention it receives in literature. I will refer to it as poignancy. Poignant emotions, such as nostalgia and the lyrical feelings pervasive in poetry, are emotions about time’s passage, or the fleetingness of things. My inquiry concerns the normative evaluation of such emotion experiences. Episodes of nostalgia and lyrical emotions are typically experienced as profound while they last, but they are also notoriously apt to be dismissed as sentimental, even by those who feel their pull. Sentimentality is a term of censure that exclusively targets emotions and emotionality; if an emotion is sentimental, then something about it is supposed to be false and wrong. But what are the merits of this charge against poignant emotions? When one has a nostalgic or lyrical emotion episode and reproaches oneself for being sentimental, who is correct—the person in the first moment, convinced by the emotion, or the person in the next, who doubts or retracts it? To adjudicate these disputes, we must turn to what I call the standard model of emotion evaluation that has emerged in the philosophy of emotions. This is a normative apparatus that enjoys wide consensus, but it has been built to evaluate the standard stock of examples in the literature, such as fear. Its application to nonstandard cases has not been undertaken. A major task of this dissertation is therefore to analyze poignant emotions in such a way that renders them evaluable on this model. However, once these analyses are in place, it turns out that the normative evaluation of poignant emotions yields surprising conclusions. In spite of their stigmatization, nostalgic aestheticizations of the past are much less vulnerable to the charge of sentimentality than commonly assumed. And lyrical feelings about the fleetingness of things are almost entirely immune to the charge, in a way that risks undermining our critical discourse about such emotion experiences.

Keywords: emotions
normativity
poignancy
sentimentality
nostalgia
Advisor: Sousa, Ronald de
Fighting Fires Together: Essays on Alliances among Fire Departments

Organizations enter into strategic alliances for economic value that cannot be achieved by working alone. Despite the potential benefits many alliances fail to meet their goals, destroy value, and end in termination. Success within alliances is neither automatic nor assured. The ways that organizations arrange their alliances to contend with impediments to success is of great practical and theoretical importance. This thesis studies how formal and informal arrangements arise over time and influence the performance of U.S. fire departments. The first study empirically describes how formal contracting influences performance of the alliance and its members. I analyze a sample of responses by US fire departments to fires over 11 years, and I describe how contracting affects four dimensions of performance: arrival minutes, resolution minutes, property damage, and casualties. I find (i) the effect of contracts varies across qualitatively different outcomes, (ii) that contracts deliver separate costs and benefits at the level of the alliance and the organization, and (iii) that estimates are sensitive to matching on pre-contracting covariates including social context. The second study examines the role played by social context in contracting. Looking at the hazard of contracting between pairs of alliance partners I examine the effects of increased embeddedness in (i) focal relationships and in (ii) networks of outside relation- ships. I find that qualitative differences in prior interactions partly explain the decision to formally contract. I find that differences in arrangements with other partners affect formal contracting both directly and indirectly through interpretations of dyadic history. These findings suggest that models of relational mechanisms that accumulate within a relationship work both in parallel and interactively with broader social networks. The third study investigates how the design of alliances affects the performance of their members. I distinguish between (i) the extent to which departments rely on their own resources versus those of their alliance partners, (ii) the formality of arrangements, and (iii) performance in terms of property damage and casualties. I find that formal contracts are needed to improve some aspects of performance while informal arrangements are sufficient for others. This finding suggests a nuanced relationship among alliance structures and outcomes.

Keywords: Strategy
Alliances
Advisor: McGahan, Anita