Digital Commons Network^™

Laboratory And Computational Mechanics-Based Framework For The Analysis And Design Of Cold Recycled Pavement Layers, Francesco Preti

Doctoral Dissertations

Cold recycling technologies are becoming increasingly popular for rehabilitation of asphalt pavements. These technologies allow construction of new pavement layers with minimal addition of heat and minimal need for transporting the material. In fact, Cold Recycled Mixtures (CRM) can be prepared in mobile plants or directly in place while using up to 100% of the milled material from an existing asphalt pavement (Reclaimed Asphalt Pavement or RAP) and without the need of heating up the aggregates. The products obtained through the use of cold recycling technologies are also commonly called Bituminous Stabilized Materials (BSM). BSM are considered to be partially-bonded …

The Dissemination And Reproduction Of Dominant Ideologies On Social Media: Reddit Through The Lens Of Color-Blind Racism And Gender-Blind Sexism, Paul Anskat

Doctoral Dissertations

This dissertation explores the frameworks of color-blind racism and gender-blind sexism as they are disseminated through the social media site Reddit. I analyze data in the form of posts and comments submitted to the site. Qualitative discourse analysis reveals employment of the frames of color-blindness and gender-blindness as well as narratives which function to anchor the dominant ideologies to apparent lived experiences. This dissertation offers two major contributions to the scholarship of racism and sexism. First, the findings demonstrate that ideologies of race and gender are often articulated through common narratives and intertwined rhetoric, establishing a foundation for future research …

Path Components And Elementary Orbits Of Um(2,R), Timothy A. Fill

Doctoral Dissertations

For any commutative ring R with identity, Um(2, R) is the set of all vectors α ∈ R^2 such that α^T β = 1 for some β ∈ R^2. Motivated by Hinson and Samuel, we endow Um(2, R) with a pseudo-graph structure and introduce a family of functions on the general ring R defined in terms of graph theoretic distance from a designated base-point or base-set. We propose a particular connected base-set whose quasi-Euclidean function exhibits the most computationally convenient properties. Unlike in Um(n, R), n ≥ 3, the relationship between path components of Um(2, R) and its orbits under …

Transport, Species-Specific Resource Competition, And Shallow Water Effects In Coupled Bio-Physical Ecosystem Models For C. Polykrikoides Harmful Algal Blooms Off The Coast Of Korea, Jang-Geun Choi

Doctoral Dissertations

This thesis examines the role of transport and environmental variables in determining the occurrence or suppression of harmful algal blooms (HABs). In the first part, a simple 2-D diagnostic model is used to hindcast HABs occurring off the coast of Korea using observations of averaged environmental factors including nutrient concentration. Hindcasting results using the model show that physical transport of HABs is of the same order of importance as the environmental conditions in controlling HABs. The model reproduces the interannual variability of the observe HABs off the coast of Korea. The relative importance of the environmental factors based on limiting …

On The Images Of Braid Group Representations Coming From Braided Fusion Categories, Jason Allen Green

Doctoral Dissertations

Braided fusion categories are algebraic structures with strong ties to the representation theory of finite groups, Hopf algebras, and quantum groups. These structures also have strong connections with braid groups and low-dimensional topology. Recently, braid group representations coming from braided fusion categories have become a topic of interest in areas of condensed matter physics and topological quantum computation. Particularly interesting are the properties of the images of these representations.

Calculations to determine the finiteness of these images have been performed for a few cases. A class of braided fusion categories coming from finite groups (group-theoretical) has been shown to yield …

Altered Alpha Oscillatory Power Dynamics Underlie Difficulties With Cognitive Flexibility, Nicole Forner

Doctoral Dissertations

Cognitive flexibility is an important mental faculty, but there are certain populations that experience reduced flexibility, which may be associated with altered neural activity. Rumination is when an individual becomes mentally stuck on a thought, and they experience difficulty shifting their attention away from the ruminative thought demonstrating reduced cognitive flexibility. In a similar manner, individuals diagnosed with substance use disorder show varying degrees of attentional bias towards drug related stimuli. The drug cues capture attention, and it is difficult for these individuals to shift attention away from thoughts related to drug cues. Both populations experience difficulty shifting attention when …

Merging Ecology And Earth System Modeling: Biotic And Abiotic Controls Drive Soil Carbon And Nitrogen Cycling In Microbial-Explicit Soil Biogeochemistry Models, Emily Kyker-Snowman

Doctoral Dissertations

Ecological processes drive terrestrial biogeochemistry, yet the incorporation of ecology into the Earth system models that we use to understand and project global change remains. My dissertation focuses on expediting the incorporation of ecology into Earth system models, first by laying out a roadmap from initial assessment of ecological insights to eventual ESM incorporation, and then by demonstrating this roadmap using the example of microbially- controlled carbon and nitrogen cycling in soil. The paradigm around SOM formation and loss has shifted in recent decades away from a focus on the chemically recalcitrant leftovers of litter decomposition and towards a paradigm …

Alkalinity And Buffering In Estuarine, Coastal And Shelf Waters, Christopher Hunt

Doctoral Dissertations

As anthropogenic climate change continues to elevate the amount of carbon dioxide (CO2) in the Earth’s atmosphere, the absorption of a large portion of this CO2 by Earth’s oceans has resulted in a steady decrease in pH. The consequent phenomenon of ocean acidification (OA) is a result of shifts in the carbonate chemistry system of the ocean- a system which can be analytically described by several factors, including total alkalinity (TA). TA in the oceans has been measured for over a century, but analytical and operational constraints have limited these measurements in time and space. Additionally, recent work has highlighted …

Balancing Fracture And Fatigue Performance In Asphalt Pavements: A Hybrid Mechanistic And Statistical Modelling Approach, Danial Mirzaiyanrajeh

Doctoral Dissertations

The asphalt mix design and evaluation approaches are divided into two main categories as empirical and mechanistic-empirical (M-E) methods. The empirical methods are based on empirical observations of in-service pavement performance, and they do not take into account engineering properties or failure criteria. The M-E methods were introduced as a new generation for design and evaluation approaches that consider fundamental mixture properties such as material stiffness to determine the pavement's structural response. However, the need for expensive and time-consuming performance-based laboratory tests and local calibration makes the M-E methods unsuitable for routing design. In addition, during the last few years, …

The Influence Of Third Parties, Perfectionism, And Familial Socioeconomic Status On College Student Mental Health And Perceptions Of Social Support, Amanda Fontaine

Doctoral Dissertations

Mental health has long been a fruitful area of sociological inquiry, and much remains to be illuminated about the ways in which the social context and intrapersonal factors intersect to impact individuals’ psychological wellbeing. Among college students particularly, stresses such as academic pressure and interpersonal conflicts contribute to the degradation of mental health. While sociological theories such as the stress process perspective have long been employed to study linkages between stress and mental wellbeing among this population, few studies have examined the specific characteristics of social relationships most beneficial to students in distress. Utilizing survey responses collected from both public …

Cover Crop-Based No-Till For Small Farms: Tradeoffs Of Termination Time, Method, And Ecosystem Services, Natalie Lounsbury

Doctoral Dissertations

Agriculture must adapt to and mitigate multiple environmental crises including climate change, overuse of herbicides, and soil degradation. Cover crops are a promising tool to do so because they protect soil from erosion, increase perenniality (i.e. year-round plant cover) and carbon contributions to farming systems, capture, recycle, and fix nitrogen, and suppress weeds through multiple mechanisms. Terminating high-residue cover crops to produce an in situ mulch for no-till production has added benefits of eliminating the need for tillage, protecting soil against extreme precipitation events and drought, and contributing to weed suppression. However, there are few non-chemical ways to terminate cover …

Self Defense And Sea Power: The Provincial Navies Of The British Atlantic World, 1689-1763, Benjamin Cameron Schaffer

Doctoral Dissertations

“Self Defense and Sea Power: The Provincial Navies of the British Atlantic World, 1689-1763,” explores the ways in which Anglo-American colonial governments in North America and the West Indies managed naval defense during imperial and border conflicts between the late seventeenth and mid-eighteenth centuries. With limited military assistance from the imperial government in London, provincial leaders built their own semi-permanent and temporary navies to protect commerce from Franco-Spanish privateers, pirates, and Native American naval forces. Provincial governments also utilized these fleets to spearhead sieges of enemy ports, support infantry operations on land, and to transport troops and supplies to warzones. …

Seneca, The Humors, And Revenge Tragedy, Andrew Stesienko

Doctoral Dissertations

This dissertation argues that moral and religious authorities of the Elizabethan and Jacobean periods adapted rules for emotional governance from Senecan philosophy. These Senecan rules helped institute a performance-based approach to managing emotion, which relied on programmatic meditation, rhetoric, and behavior to change one’s emotional state. This approach ostensibly offered more personal control over affective inclination, which according to the period’s Galenic paradigms, was heavily influenced by environmental and physiological factors. My project examines revenge tragedy to highlight Senecan-inspired affect management as practiced by aspiring avengers. Because revenging hopefuls must amplify and then mobilize their feelings in order to achieve …

Study Of Primary Cilia In Early Development, Pharmacology, And Brainwave Activity., Matthew Roderick Strobel

Doctoral Dissertations

The primary cilium is a unique cellular organelle that emanates from the mother centriole and extends out of the plasma membrane of nearly every mammalian cell. While originally believed to be a vestigial appendage, the cilium is now known to be a signaling hub where various intercellular communication pathways intersect to regulate morphogenesis, proliferation, polarity, differentiation, and homeostasis. Due to their importance in regulating cellular functions the cilium has become a growing focus of biomedical research as it has been linked to at least 35 human developmental disorders which have been termed ciliopathies. In the nervous system, primary cilia regulate …

Learning To Act With Robustness, Reazul Hasan Russel

Doctoral Dissertations

Reinforcement Learning (RL) is learning to act in different situations to maximize a numerical reward signal. The most common approach of formalizing RL is to use the frameworkof optimal control in an inadequately known Markov Decision Process (MDP). Traditional approaches toward solving RL problems build on two common assumptions: i) exploration is allowed for the purpose of learning the MDP model and ii) optimizing for the expected objective is sufficient. These assumptions comfortably hold for many simulated domains like games (e.g. Atari, Go), but are not sufficient for many real-world problems. Consider for example the domain of precision medicine for …

Economics Of Pest Control And Pollination Conservation: Perspectives From A Bioeconomic Model And A Choice Experiment, Linghui Wu

Doctoral Dissertations

The first chapter focuses on the need to reduce pollinator exposure to harmful pesticides has led to calls to expedite theadoption of integrated pest management (IPM). We make the case that IPM is not explicitly 'pollinator friendly', but rather must be adapted to reduce impacts on pollinators and to facilitate synergies between crop pollination and pest control practices and ecosystem services. To reconcile these diverse needs, we introduce a systematic framework for 'integrated pest and pollinator management' (IPPM). We also highlight novel tools to unify monitoring and economic decision-making processes for IPPM and outline key policy actions and knowledge gaps. …

The Propagation And Evolution Of Coronal Mass Ejection Driven Sheath Regions: Insight From Multi-Spacecraft Measurements And Statistical Approaches, Tarik Mohammad Salman

Doctoral Dissertations

The complexities of our nearest star, the Sun, are characterized by its magnetic field. In the absence of a magnetic field, diverse phenomena as the solar cycle, solar eruptions, solar wind, to name but a few, would be unknown to us. Coronal mass ejections, a large form of solar eruption, are an essential mechanism for the evolution of the Sun. CMEs provide a means by which the built-up magnetic flux and solar material over solar cycles are removed from the solar atmosphere into the solar wind. This spectacular phenomenon has repercussions throughout the heliosphere, driving a range of heliospheric, magnetospheric, …

A Comprehensive Study Of The Hardware Trojan And Side-Channel Attacks In Three-Dimensional (3d) Integrated Circuits (Ics), Zhiming Zhang

Doctoral Dissertations

Three-dimensional (3D) integration is emerging as promising techniques for high-performance and low-power integrated circuit (IC, a.k.a. chip) design. As 3D chips require more manufacturing phases than conventional planar ICs, more fabrication foundries are involved in the supply chain of 3D ICs. Due to the globalized semiconductor business model, the extended IC supply chain could incur more security challenges on maintaining the integrity, confidentiality, and reliability of integrated circuits and systems. In this work, we analyze the potential security threats induced by the integration techniques for 3D ICs and propose effective attack detection and mitigation methods. More specifically, we first propose …

Mechanistic Modelling Framework And Life Cycle Assessment Approach For Pavement Rehabilitation Using Asphalt Concrete Overlays, Katie Eileen Haslett

Doctoral Dissertations

Efficient and effective rehabilitation of existing roadways continues to be a top priority for local, state, and federal agencies to provide safe travel of people and goods. Asphalt concrete (AC) overlays on deteriorated Portland Cement Concrete (PCC) are a popular rehabilitation option to extend the service life of a roadway. However, the combination of load and environmentally induced movements at underlying joint locations can cause high amounts of stresses and strains, leading to the formation of cracks in the AC overlay. Ensuring that a suitable asphalt mixture (cracking resistance) and sufficient overlay structure (thickness) are selected is critical to avoid …

Repeatfs: A File System Providing Reproducibility Through Provenance And Automation, Anthony Stephen Westbrook

Doctoral Dissertations

Reproducibility is of central importance to the scientific process. The difficulty of consistently replicating and verifying experimental results is magnified in the era of big data, in which computational analysis often involves complex multi-application pipelines operating on terabytes of data. These processes result in thousands of possible permutations of data preparation steps, software versions, and command-line arguments. Existing reproducibility frameworks are cumbersome and involve redesigning computational methods. To address these issues, we developed two conceptual models and implemented them through RepeatFS, a file system that records, replicates, and verifies computational workflows with no alteration to the original methods. RepeatFS also …

Mathematical Analysis Of A Model Of Blood Flow Through A Channel With Flexible Walls, Madeline Mayes Edwards

Doctoral Dissertations

The present research is devoted to the problem of stability of the fluid flow moving in a channel with flexible walls and interacting with the walls. The walls of the vessel conveying fluid are subject to traveling waves. Experimental data shows that the energy of the flowing fluid can be transferred and consumed by the structure (the walls), which induces “traveling wave flutter.” The problem of stability of fluid-structure interaction splits into two parts: (i) stability of fluid flow in the channel with harmonically moving walls and (ii) stability of solid structure participating in the energy exchange with the flow. …

Nanoelectronic Devices For Sensitive Detection Of Biomarkers In Healthcare Monitoring, Md Niazul Islam Khan

Doctoral Dissertations

In recent years, biosensors have seen an exponential rise of their applications in a number of fields including the field of health care monitoring, particularly in point-of-care diagnostics. With the contemporary rise of nanotechnology, these biosensors have experienced an ever-growing inclusion of nano scale electronic devices or nanoelectronic devices to exploit the plethora of advantages of nanoelectronics. The performances of these nanoelectronic devices, however, largely depend on the nanomaterials used. Especially, carbon-based nanomaterials such as carbon nanotubes (CNTs) and graphene have proven to be superior candidates compared to others because of their multitude of electronic and mechanical properties suitable for …

Existence Of Mutual Stabilization In Chaotic Neural Models, John Parker

Doctoral Dissertations

Recent work has demonstrated that interacting chaotic systems can establish persistent, periodic behavior, called mutual stabilization, when certain information is passed through interaction functions. In particular, this was first shown with two interacting cupolets (Chaotic Unstable Periodic Orbit-lets) of the double scroll oscillator. Cupolets are highly accurate approximations of unstable periodic orbits of a chaotic attractor that can be generated through a control scheme that repeatedly applies perturbations along Poincaré sections. The decision to perturb or not to perturb the trajectory is determined by a bit in a binary control sequence. One interaction function used in the original cupolet research …

Discourses Of Diversity: A Qualitative Case Study Of World Language Pedagogies Through An Intersectional Lens, Sheri Dion

Doctoral Dissertations

Schools are becoming more linguistically and racially diverse in K-12 settings, yet there is relatively little research that explores how language teachers incorporate student and community diversities in their pedagogies. Situated at one, northeastern public secondary school in the United States, this research offers a qualitative case study of language pedagogies through an intersectional lens to investigate the mechanisms and contexts through which inequities arise. Data is collected from the following sources: teacher interviews, classroom observations, teachers’ syllabi, and student de-identified work. This study employs intersectionality (Collins & Bilge, 2016; Crenshaw, 1989, 2010) as a primary theoretical lens and critical …

Nickel – Iron Catalysts For Low Temperature Dry Reforming Of Methane, Gagandeep Dhillon

Doctoral Dissertations

Dry reforming of methane (DRM) offers benefit of consuming two important greenhouse gases(CH4 and CO2) in a single reaction to produce syngas. Ni-based catalysts have been studied for DRM. However, monometallic Ni catalysts deactivate mainly because of coking. We were motivated to include earth-abundant promoter metals to suppress coke formation and studied a series of bimetallic nickel-iron catalysts supported over TiO2 and TiO2-CeO2 at 550˚C and atmospheric pressure. This dissertation mainly focuses on various approaches to synthesize Ni-Fe catalysts and examines the effect of oxide support modification over optimum Ni-Fe/TiO2 catalyst. In this context, Ni-Fe catalysts supported over TiO2 were …

Performance Evaluation And Review Framework Of Robotic Missions (Perform): Autonomous Path Planning And Autonomy Performance Evaluation, Allisa Dalpe

Doctoral Dissertations

The scope of this work spans two main areas of autonomy research 1) autonomous path planning and 2) test and evaluation of autonomous systems. Path planning is an integral part of autonomous decision-making, and a deep understanding in this area provides valuable perspective on approaching the problem of how to effectively evaluate vehicle behavior.

Autonomous decision-making capabilities must include reliability, robustness, and trustworthiness in a real-world environment. A major component of robot decision-making lies in intelligent path-planning. Serving as the brains of an autonomous system, an efficient and reliable path planner is crucial to mission success and overall safety. A …

Life, Liberty, And The Pursuit Of Police Officer Acquittals: Jurors' Explicit And Implicit Racism, Donovan Corson Kelley

Doctoral Dissertations

Less than .001% of cases involving police officers killing suspects result in trial convictions; acquittals are significantly higher for Black victims than for White victims. The purpose of this dissertation was to examine if explicit and implicit racism amongst jurors helped explain why police officers are rarely convicted of murder, especially in cases with Black victims. In a pilot study in which mock jurors read a trial summary involving an officer killing an unarmed victim who was either Black or White, jurors were more likely acquit officers on trial for killing a Black victim than a White victim. In Study …

Exploring Mathematical Connections Preservice Teachers Make Between Abstract Algebra And Secondary Mathematics: Implications For Learning And Teaching, Cammie Gray

Doctoral Dissertations

Abstract algebra has been identified as an important course for preservice secondary mathematics teachers because much of the abstract algebra content is connected to, and thus relevant for, secondary mathematics teaching (Wasserman et al., 2017). However, many preservice teachers do not recognize the usefulness of an undergraduate abstract algebra course and see no relation between abstract algebra and secondary school mathematics (Christy & Sparks, 2015; Ticknor, 2012). While much of the research regarding preservice teachers making connections to secondary school mathematics in abstract algebra has been conducted in courses designed for preservice teachers, the research suggests that most universities with …

Toward A Feminist Rhetorical Strategy Of Sass: Sheila Hibben As America’S Early 20th Century Culinary Influencer, Meaghan Elliott Dittrich

Doctoral Dissertations

My dissertation restores to the canon of women’s rhetorical history a voice who, in her time of the early twentieth century, made a mark on the world of food writing. By identifying Sheila Hibben’s rhetorical strategy of sass as a method of critiquing hierarchies and as a feminist rhetorical practice, my work contributes to the field of rhetoric and composition.This dissertation defines and deconstructs Sheila Hibben’s sass as a rhetorical strategy during two essential periods of economic crises—the Great Depression and World War II—to influence two audiences of white working- and upper-class housewives to eat well during times of national …

Wind, Wave, And Engineering Effects On Tidal Inlet Morphodynamics, Joshua Lincoln Humberston

Doctoral Dissertations

This body of work examines the hydro- and morpho-dynamics of tidal inlets using a diverse array of research tools. A custom X-band radar system (RIOS) is designed and used to track the evolution of shoal features over the ebb-tidal delta at Oregon Inlet, NC. Analysis of the data reveals that alongshore shoal migration rates are closely correlated to wave driven alongshore sediment transport, and also that the cross-shore bedform migration rates are tightly correlated with a sub-tidal water level gradient though the inlet. A follow up experiment with in-situ sensors suggests that the sub-tidal gradient is set up by regional …