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Population Structure And Non-Nestmate Aggression Within Black Carpenter Ant, Camponotus Pennsylvanicus, Adam Salyer

Open Access Dissertations

Black carpenter ants, Camponotus pennsylvanicus (DeGeer), are an important urban destructive pest native to North America. Little is known about the dispersal, ecology, or behavior of the black carpenter ant due to its cryptic nesting habitats and nocturnal ecology. Knowledge of C. pennsylvanicus population structure and intraspecific competition is needed to predict potential range expansion, dispersal, and establishment of future black carpenter ant populations in the context of climate change. This research investigated population structure and potential prevalence of increased aggression toward neighboring colonies, known as the “nasty-neighbor” effect, within C. pennsylvanicus. Within this research, I test the hypothesis that …

Modeling And Optimization Of Dynamical Systems In Epidemiology Using Sparse Grid Interpolation, Aditya P. Sai

Open Access Dissertations

Infectious diseases pose a perpetual threat across the globe, devastating communities, and straining public health resources to their limit. The ease and speed of modern communications and transportation networks means policy makers are often playing catch-up to nascent epidemics, formulating critical, yet hasty, responses with insufficient, possibly inaccurate, information. In light of these difficulties, it is crucial to first understand the causes of a disease, then to predict its course, and finally to develop ways of controlling it. Mathematical modeling provides a methodical, in silico solution to all of these challenges, as we explore in this work. We accomplish these …

Latent Representation And Sampling In Network: Application In Text Mining And Biology., Tanay Kumar Saha

Open Access Dissertations

In classical machine learning, hand-designed features are used for learning a mapping from raw data. However, human involvement in feature design makes the process expensive. Representation learning aims to learn abstract features directly from data without direct human involvement. Raw data can be of various forms. Network is one form of data that encodes relational structure in many real-world domains. Therefore, learning abstract features for network units is an important task. In this dissertation, we propose models for incorporating temporal information given as a collection of networks from subsequent time-stamps. The primary objective of our models is to learn a …

Measurements Of Transition Dominated By The Second-Mode Instability At Mach 6, Brandon C. Chynoweth

Open Access Dissertations

Hypersonic boundary-layer transition can be caused by many different mechanisms. This research focuses on studying the growth and breakdown of the second-mode instability. Experiments were performed in the Boeing/AFOSR Mach-6 Quiet Tunnel located at Purdue University. This facility has freestream noise levels similar to conditions in flight making it an excellent facility to study laminar-turbulent boundary-layer transition.

Using a flared cone model, measurements were first made with a smooth wall to characterize natural second-mode transition. As the second-mode amplitude increased up to a maximum of nearly 30% of the mean static pressure, streamwise streaks of heating were observed forming around …

Oxidative Transfer Reactions At A Metal-Metal Bond, Heather Rounds

Open Access Dissertations

Strained, three-membered rings were found to undergo oxidative addition to [iPrNDI]Ni2(C6H6) complex [NDI = napthyridine-diimine). Activation of the C-N bond of 1-tosyl-2-vinylaziridine generates a dinickel metallacyclic product. Based on this reactivity, the [iPrNDI]Ni2(C6H6) complex was shown to be a highly active catalyst for rearranging vinylcyclopropanes to cyclopentenes. Notably, 2-phenyl-1-vinylcyclopropane undergoes regioselective activation at the less hindered C–C bond in contrast to the non-catalytic thermal rearrangement. The dinuclear complex was also found to readily rearrange hetero-atom containing cyclopropanes to their linear products. DFT calculations provide insight into the ability of the Ni–Ni bond to stabilize key intermediates and transition states along …

Football Study Hall And Self-Regulated Learning, Seth M. Schwartz

Open Access Dissertations

The present study sought to determine whether there were differences among football student-athletes’ (FSAs’) self-regulated learning (SRL) and first-semester achievement depending on the type of study hall—traditional (TSH), objective-based (OBSH) or objective-based plus weekly academic success strategy instruction (OBSH-Plus)—implemented at their institution. The SRL measures included self-efficacy, use of cognitive strategies, and use of metacognitive strategies. After examining the distribution of FSA’s ethnicity and high school academic achievement (i.e., high school GPA and ACT scores) across programs, it was determined that the FSAs in the OBSH and the OBSH-Plus were comparable in these areas, however they differed significantly from the …

Revisiting Rustow: An Empirical Assessment Of The Relationship Between National Identity And Attitudes Towards Democracy In Post-Soviet Russia, John P. Schultz

Open Access Dissertations

Does national identity influence a country’s prospects for democratization? Brudny and Finkel (2011) contend that national identity explains variation in the political developments among former Soviet states. In considering this argument, this effort examines the empirical evidence to determine 1) whether a measurable model of national identity has developed within Russia, 2) how this national identity has developed over time, and 3) whether a relationship exists between this intersubjectively held conception of national identity and attitudes towards democracy. Findings suggest the development and ongoing contestation of two competing conceptions of national identity that covary with changing attitudes towards democracy over …

Electro-Thermal Transport In Non-Homogenous Network, Sajia Sadeque

Open Access Dissertations

Nano-structured networks have drawn attention as potential replacements for bulk-material approaches in applications including transparent conducting electrodes (TCEs). As TCEs, these systems can provide relatively low sheet resistances in the high optical transmission regime along with excellent mechanical flexibility. While percolation models have been developed to describe the general trends in sheet resistance and transmittance on nanowire density, prior experiments have not yielded details such as distributions of junction resistances and current pathways through the networks. Most experimental studies on nanostructured TCE properties have focused on large area steady state exploration of electrical and optical properties or more microscopic studies …

Semiclassical Resolvent Estimates And Wave Decay In Low Regularity, Jacob Z. Shapiro

Open Access Dissertations

In this thesis, we prove weighted resolvent upper bounds for semiclassical Schr¨odinger operators. These upper bounds hold in the semiclassical limit. First, we consider operators in dimension two when the potential is Lipschitz with long range decay. We prove that the resolvent norm grows at most exponentially in the inverse semiclassical parameter, while near infinity it grows at most linearly. Both of these bounds are optimal. Second, we work in any dimension and require that the potential belong to L∞ and have compact support. Again, we find that the weighted resolvent norm grows at most exponentially, but this time with …

Ground States Of The Two-Dimensional Electron System At Half-Filling Under Hydrostatic Pressure, Katherine A. Schreiber

Open Access Dissertations

A many-body electron system in two dimensions at high magnetic field hosts a diverse set of electron ground states. Many of these ground states have been well understood for years, yet some continue to challenge researchers. The ν =5/2 fractional quantum Hall state at half-filling is perhaps the most mysterious state. It holds the promise of novel physics such as non-Abelian statistics, and it possesses topological order, both properties of great interest due to potential applications for robust quantum computing. However, despite many experiments to this date, questions surround the exact nature of ν =5/2 fractional quantum Hall state. This …

Discourse, Documents, And Counter-Discipline: Michel Foucault’S Ethics And The Practice Of Writing, Strand Sheldahl-Thomason

Open Access Dissertations

Michel Foucault spent the last years of his life in an investigation of ancient ethical practices. The practices can be summarized in one phrase: the care of the self. Although this investigation grows out of Foucault’s interest in biopolitics and sexuality, and is ostensibly a continuation of his History of Sexuality project, it nonetheless reconfigures that project and adds to it the dimension of subjectivity. It therefore presents a challenge to Foucault scholarship. Broadly speaking, critics have taken Foucault’s ethical turn to signify either a retreat from politics or a historical investigation of how ancient people internalized social possibilities. I …

Evaluation Of A Redesigned Chemistry Course Sequence For Undergraduate Life Science Majors, Carly Lynn Schnoebelen

Open Access Dissertations

In response to both nationwide calls for reform and a perception that the existing chemistry curriculum was not meeting the needs of life science students, faculty in the department of chemistry at Purdue created a redesigned chemistry course sequence specifically aimed at preparing biology majors. The new sequence, called the 1-2-1 curriculum, spans four semesters of instruction, including one semester of general chemistry, two semesters of organic chemistry, and one semester of biochemistry. The 1-2-1 curriculum was implemented in the 2013-2014 academic year, and students appeared to be progressing through successfully. However, there was a need for a more systematic …

Quantum Transport In The Algaas/Gaas Two Dimensional Electron System At Half-Fillings., Qi Qian

Open Access Dissertations

Recently great research effort has been put toward the study of strongly correlated electron systems, of particular interest is the intriguing quantum phases at half-filled Landau levels (LL), including the exotic fractional quantum Hall state (FQHS) at filling factor ν = 52 in the N = 1 LL, and density modulated phases in high LLs (N ≥ 2). The state of the art AlGaAs/GaAs heterostructure grown by molecular bean epitaxy provides a superior platform to study these many-body interactions. In this thesis, a brief introduction of different phases in half-filled LLs is given in Chapter 1. The remaining chapters, summarized …

Synthesis And Characterization Of Model Acrylic-Based Polymer Gels, Travis Lawrence Thornell

Open Access Dissertations

Materials made from polymer gel networks are important to many everyday applications in health care to building materials. These gel materials can be easily synthesized in various ways, but characterizing the overall material mechanics and properties are challenging due to the soft nature of their respective bulk structures. Model acrylic-based copolymer gels were investigated to understand the fundamental characteristics and mechanical properties from different crosslinking and gelation processes. First, model hydrogels with fracture-healing characteristics similar to materials needed for injectable drug delivery systems were studied using shear rheology to determine timescales of fully healed networks. The industrially available gel was …

Synergistic Effects Of High Particle Fluxes And Transient Heat Loading On Material Performance In A Fusion Environment, Gregory Poppy Sinclair

Open Access Dissertations

The work presented in this thesis focuses on the thermal and structural evolution of different materials when exposed to both high-flux ion irradiation and high intensity pulsed heat loading. Nuclear fusion devices create an intense radiation environment consisting of very energetic deuterium (D+) and helium (He+) ions. During operation, off-normal plasma events, such as edge-localized modes (ELMs), could cause intense heating of the plasma-facing component (PFC) surface, leading to melting and possible splashing into the fusion plasma. High-Z, refractory metals, such as tungsten (W), are therefore seen as favorable, due to their high melting point, high thermal conductivity, and low …

Multi-Dimensional Simulation And Experimental Benchmarking Of Ultrashort Pulsed Laser Interactions With Metallic Targets, Anastassiya Suslova

Open Access Dissertations

In this work, ultrashort pulsed laser interactions with metallic targets and laser-induced effects were theoretically investigated, and the multi-dimensional simulation package FEMTO-2D was developed based on the solution of two non-linear heat conduction equations for electron and lattice sub-systems. Inverse Bremsstrahlung absorption was considered as primary light absorption mechanism. The laser-target interaction was assumed to occur at solid-like material density since laser pulse duration is orders of magnitude shorter than the time required for material thermal expansion. A theoretical approach based on the collision theory had been implemented to define the thermal dependence of target material optical properties and thermodynamic …

Algorithmic Advances To Increase The Fidelity Of Conceptual Hypersonic Mission Design, Harish Saranathan

Open Access Dissertations

The contributions of this dissertation increase the fidelity of conceptual hypersonic mission design through the following innovations: 1) the introduction of coupling between the effects of ablation of the thermal protection system (TPS) and flight dynamics, 2) the introduction of rigid body dynamics into trajectory design, and 3) simplifying the design of hypersonic missions that involve multiple phases of flight. These contributions are combined into a unified conceptual mission design framework, which is in turn applicable to slender hypersonic vehicles with ablative TPS. Such vehicles are employed in military applications, wherein speed and terminal energy are of critical importance. The …

Understanding And Improving The Non-Cognitive Factors That Affect First-Year Engineering Performance, Ryan Senkpeil

Open Access Dissertations

To maintain America’s status as a global technological leader, there has been a longstanding effort to increase the quality and quantity of engineers in the workforce. Previous research and government reports have called on the education system at all levels to increase enrollment and persistence in college engineering programs. Additionally, engineering employers continue to be dissatisfied with the skills obtained by those students who do persist to graduation, in part because those students that may become the best engineers are leaving engineering. In order to effectively recruit and retain the best engineering students, the factors that affect engineering student success …

Bayesian Nonparametrics To Model Content, User, And Latent Structure In Hawkes Processes, Xi Tan

Open Access Dissertations

Communication in social networks tends to exhibit complex dynamics both in terms of the users involved and the contents exchanged. For example, email exchanges or activities on social media may exhibit reinforcing dynamics, where earlier events trigger follow-up activity through multiple structured latent factors. Such dynamics have been previously represented using models of reinforcement and reciprocation, a canonical example being the Hawkes process (HP). However, previous HP models do not fully capture the rich dynamics of real-world activity. For example, reciprocation may be impacted by the significance and receptivity of the content being communicated, and modeling the content accurately at …

“Though Troubled Be My Brain:” Madness In Early Modern England, 1603-1714, Alison R. Shimko

Open Access Dissertations

This dissertation is a study of madness in Stuart-era England. Madness was pervasive in early modern England. it was in the streets, performed on stage, discussed in political pamphlets and legal treatises, and physically housed in Bethlehem Hospital. Madness, therefore, serves as a significant lens because in differentiating between madness and sanity, contemporaries regularly drew clear boundaries between acceptable, or “normal” behavior, and unacceptable, or “abnormal” behavior, that was particular to seventeenth-century English culture and society. Specifically, I argue that madness serves as a channel to examine the diagnoses and treatment of mental disorders that contemporaries believed altered the body …

Haremization Of Desdemona: A Comparative Study Of Shakespeare’S Othello In The Ottoman Context, Tulin Ece Tosun

Open Access Dissertations

My dissertation takes a comparative approach by setting Shakespeare’s Othello within the context of Ottoman history and the Ottoman harem to represent current Middle Eastern trends in the field of Comparative Literature. I argue that Othello paints a portrait of stereotypical Muslim characteristics drawn from the travel narratives of Richard Hakluyt, Richard Knolles, and Paul Rycaut. I use these travel narratives to identify cross-cultural relationships, comparisons, interactions, and psychology. In my final chapter, I argue that from a certain perspective, Othello is a Turk because Shakespeare turns the citadel in Cyprus into a harem. The word harem, stemming from the …

Spin-Torque Sensors For Energy Efficient And High Speed Global Interconnects, Zubair Al Azim

Open Access Dissertations

Reduction of power dissipation in global interconnect lines while maintaining fast performance is an ongoing challenge in scaled CMOS technology. In order to address this issue, we propose low-voltage, low-current interconnect architectures using spin-torque (ST) sensors that can optimize the overall delay and energy consumption. Conventional techniques for reducing power dissipation on long interconnects involve low voltage swing on the interconnect lines. However, such techniques require power consuming voltage converters or trans-impedance amplifiers at the receivers. We propose ST sensor based signal conversion at the receiver that offers an efficient signal conversion process. The proposed ST sensor devices consist of …

Bridge Load Rating: A General Procedure For Load Rating Bridges Without Plans, Rafael Ricardo Armendariz Briones

Open Access Dissertations

The inspection and evaluation of bridges is critical to ensure their safety and better serve the citizens of the nation. Part of this evaluation includes bridge load rating. Bridge load rating, which is a measure of the safe load capacity of the bridge, is typically conducted by using critical information that is available on the bridge plans. For existing, poorly-documented bridges the load rating process becomes challenging to complete because of the missing bridge information. Currently, a general prescribed methodology for load rating such bridges is not available. Consequently, there is a need for a standardized methodology to load rate …

A Pragmatic Methodology For The (Queer) Self, Elaine M. Blum

Open Access Dissertations

Taking LGBTIA+ experiences as the starting point for theorizing, I propose that pragmatic methodologies ameliorate several problems that queer theory encounters in defining queer subjectivity. The challenge is that any definition of queer selfhood must simultaneously (i) elude essential or fixed definitions of the subject, gender, and the relationship between them, and nonetheless (ii) enable efficacious political action and recognition. Utilizing the work of John Dewey and Jane Addams, I argue that the social self provides a beneficial framework for accommodating and celebrating queer lives. Adopting a pragmatic methodology emphasizes the irreducible plurality of perspectives and develops theory out of …

Pre-Service Teachers' Understanding The Measurement Of The Area Of Rectangles, Cetin Kursat Bilir

Open Access Dissertations

Existing research has identified pre-service teachers’ (PTs’) difficulties with measuring the area of rectangles and explaining their approaches to area measurement. Yet, little is known about elementary PTs’ understandings of area measurement. Existing research has focused on children’s understanding of area measurement in the context of rectangles and has identified mental processes they use to construct area measurement. The study described in this report contributes to and extends this literature by exploring elementary PTs’ understandings of area measurement in the context of rectangles. Clinical interview methodology was used to investigate four PTs’ mental processes used in area measurement tasks. Study …

Analysis Of Packaged Air Conditioning System For High Temperature Climates, Ammar M. Bahman

Open Access Dissertations

Packaged air conditioning (AC) units, called Environmental Control Units (ECUs), are being increasingly used by the U.S. military, especially in hot ambient temperature climates. The compact packaging of ECUs resembles unitary-type rooftop or room AC systems, and they are used to cool personnel and equipment in enclosed spaces such as shelters, vehicles, and containers. Despite these similarities, ECUs have distinctive features that aren’t found in commercial packaged AC units. An ECU is designed to sustain harsh and extreme weather conditions up to 51.7°C(125°F) which is a design set-point by the military. As the outdoor temperature increases, both the cooling capacity …

Multi-Hazard In-Plane Response Of Steel-Plate Composite (Sc) Walls: Out-Of-Plane And Accident Thermal Loadings, Saahastaranshu R. Bhardwaj

Open Access Dissertations

Steel-plate composite (SC) walls have been used for the third generation of nuclear power plants, and are being considered for small modular reactors of the future. Modular SC walls are also being considered for commercial applications, owing to their structural efficiency and construction economy. Walls in important structures may be subjected to a combination of loadings due to cascading hazards. Experimental and numerical studies were conducted to evaluate the in-plane response of SC walls (with boundary elements) and wall piers (without boundary elements) subjected to out-of-plane and accident thermal loadings. First series of experiments comprised of four SC wall pier …

On The Computation And Composition Of Belyi Maps And Dessins D'Enfants, Jacob A. Bond

Open Access Dissertations

This dissertation centers on computing with dessins d’enfants, in the form of constellations, and on the monodromy group of compositions of Bely˘ı maps. To begin, a discussion of known e ective and eÿcient algorithms for computing constellations, Bely˘ı Maps, and dessins d’enfants from one another is presented. Following this is an analysis of how to use double cosets in an optimal way to count equivalence classes of constellations. In addition, class multiplication coeÿcients are used to count trees with certain passports, culminating in a new proof of a result of Mednykh. The method given by Wood for computing the constellation …

Sex, Culture, And The Politics Of Fashion In Stuart England, Emilie M. Brinkman

Open Access Dissertations

This dissertation is the first full-length study to analyze the politicization of dress and material objects, exploring the manner in which fashion served as a site for political discourse and agency, during the seventeenth century, specifically from 1603–1702, an era characterized by profound political, religious, and social turmoil as well as increased international trade and luxury consumption. This dissertation demonstrates how fashion, which encompassed clothing, accessories, hairstyling, and cosmetics, was an important facet of political culture within Stuart England and, furthermore, was absolutely fundamental to how the English understood themselves, others, and the turbulent world they lived in. I argue …

Minimal Models Of Rational Elliptic Curves With Non-Trivial Torsio, Alexander J. Barrios

Open Access Dissertations

This dissertation concerns the formulation of an explicit modified Szpirobconjecture and the classification of minimal discriminants of rational elliptic curves with non-trivial torsion subgroup. The Frey curve y2=x( x+a) ( x-b) is a two-parameter family of elliptic curves which comes equipped with an easily computable minimal discriminant which helped pave the mathematical bridge that led to the proof of Fermat's Last Theorem. In this dissertation, we extend the ideas of the Frey curve by considering two- and three- parameter families of elliptic curves which parameterize all rational elliptic curves with non-trivial torsion. First, we use these families to give a …