Digital Commons Network^™

Modeling And Simulation Of Blood Flow Past The Distal Anastomosis Of The Arteriovenous Graft For Hemodialysis, Zengding Bai

Open Access Dissertations

Hemodialysis is a common treatment for ESRD patients to manage their chronic renal failure while awaiting kidney transplant. Arteriovenous graft is a major vascular access for hemodialysis but often fails due to the thrombosis close to the anastomosis. Most of existing computational models employ an unrealistic rigid model assuming the vein and graft are rigid. And some of the existing results are inconsistent in characterizing the flow and force fields. We introduce a new three-dimensional computational model that incorporates the vein and graft deformability. The new model is based on the lattice Boltzmann-immersed boundary (LB-IB) framework for handling the fluid-flexible-structure …

Gender And Parental Support To Adult Children In Later Life, Gülçin Con

Open Access Dissertations

Background and Objectives: Past research has examined gender differences between mothers’ and fathers’ ties with their adult children; however, the interdependency between mothering and fathering for adult children was left unexamined. This study addresses this gap by examining the extent to and ways in which parental support to adult children in later life is initiated and negotiated among married couples, and whether these patterns reflect the gendered patterns and practices found in parental involvement earlier in the life course. Research Design and Methods: I conducted in-depth in-person interviews with 34 parents on their ties with each of their adult children. …

Secular Discourse In Postcolonial West African Narratives: Problems And Perspectives: A Comparative Study, Malick Coly

Open Access Dissertations

The making of modern African nations and their attendant secularistic establishment have not only altered traditional socio-political structures, this shift has equally affected the relations between individuals as well as communities. In the process leading to modern sociocultural transformations, tensions and discourse have arisen. Toyin Falola’s Violence in Nigeria: Crisis of Religious Politics and Secular Ideologies, and Ousman Murzik Kobo’s Unveiling Modernity in Twentieth-Century West African Islamic Reforms highlight respectively the political and religious divide in post-Independence Nigeria and the impact of Islamic reform in Ghana and Burkina Faso. These two historical studies show the complexity of modern West African …

Label Free Chemical Imaging Reveals Novel Metabolite Signatures In Living Model Organisms, Jing (Andy) Chen

Open Access Dissertations

Cell and molecular biology often need direct monitoring of the dynamic distribution and interactions of metabolites in living cells and model organisms. However, this task is extremely challenging for a few reasons. Labeling metabolites with markers can potentially interrupt the dynamic cellular events that are aimed to be observed. Moreover, labeling dyes are usually toxic to cells. Lastly, many labeling methods require cell fixation thus cannot be used to study cellular dynamics. Label-free chemical imaging methods such as stimulated Raman scattering (SRS) circumvent these problems by generating signals based on the intrinsic optical property of target biological metabolites. As a …

Computational Methods For Matrix/Tensor Factorization And Deep Learning Image Denoising, Joon Hee Choi

Open Access Dissertations

Feature learning is a technique to automatically extract features from raw data. It is widely used in areas such as computer vision, image processing, data mining and natural language processing. In this thesis, we are interested in the computational aspects of feature learning. We focus on rank matrix and tensor factorization and deep neural network models for image denoising.

With respect to matrix and tensor factorization, we first present a technique to speed up alternating least squares (ALS) and gradient descent (GD) − two commonly used strategies for tensor factorization. We introduce an efficient, scalable and distributed algorithm that addresses …

Hispanic Acculturation And Perceived Discrimination's Impact On Emerging Adult's Internalizing And Externalizing Symptoms Over Time: A Longitudinal Investigation., Hector F. De Los Santos

Open Access Dissertations

Perceived discrimination and acculturation are key minority status and cultural variables that impact Hispanic mental health. Despite discrimination being a chronic stressor and acculturation being a developmental process, the impact of these experiences have been primarily investigated cross-sectionally. This paper uses longitudinal analyses to explore how perceived discrimination and acculturation impact growth internalizing and externalizing symptoms over time, adding nuance to previous literature. Using the Pathways to Desistance Mexican American sample (N =332), this paper utilized latent growth curve analyses to evaluate acculturative theories on mental health and the immediate and longitudinal impact of discrimination on a broad spectrum of …

Conventions Of The Commons: Technical Communication And Crowdsourced Digital Publishing, Amelia Chesley

Open Access Dissertations

This project traces the digital publishing history of the audiobook archive LibriVox.org, examining how its volunteers manage, control, and negotiate procedures and policies for their ongoing collaborative work. Examples of public knowledge work like LibriVox illustrate the value of professional and technical communication in accessibly digitizing knowledge and culture for use now and in the future. I investigate and theorize how groups of diverse and transient volunteers create and engage with the tools and documentation they use to manage their crowdsourced audio digitization work. The example of LibriVox can help us better recognize and value the invitational care work embedded …

"Do I Even Remember The List?': Identity, Place, And Legal Consciousness Of Marriage Among Lgbtq Individuals.", D Ross Beall

Open Access Dissertations

The legalization of same-sex marriage in 2015 in the United States has been a milestone for LGBTQ rights. Popular campaigns pushing for the legalization argued that “love is love” and the idea that same-sex marriage is the same as heterosexual marriage. While there have been surveys investigating popular opinions around same-sex marriage, not much research has been done on LGBTQ communities themselves and what they have to say about marriage. This dissertation obtains a clearer understanding of how LGBTQ individuals consider marriage at a critical moment in history. Specifically, this dissertation investigates how identity, place, and legal consciousness interact within …

On The Front Line: Locating Mentorship In The Composition Practicum, Sherri Elaine Craig

Open Access Dissertations

This dissertation is a qualitative study of fifteen WPA instructors of the composition practicum. Driven by the primary research question, how do WPAs enact mentorship within composition practicum?, the study sought to better identify how WPAs enact and perceive mentorship within the composition practicum through an activity-theory framework in three distinct phases: a collection and analysis of twenty-six pedagogical materials, twelve structured interviews, and one case study. Through these phases, it was determined the difficulty of locating mentorship of TAs required distinguishing between performing mentoring acts and establishing mentoring relationships first, and second, a construction of the practicum course materials …

Social Brokerage, Psychology, And Innovation In Intra-Organizational Networks, Hongzhi Chen

Open Access Dissertations

As an important organizational phenomenon, brokerage is common in any group of three or more. A recent meta-analysis shows that brokerage is one of the most influential network properties to individual innovativeness (Baer, Evans, Oldham, & Boasso, 2015). This dissertation investigates the impacts of social brokerage on the micro-foundation of corporate innovation, i.e., generating new projects and getting new things done. In addressing the social psychological foundations of brokerage (Tasselli, Kilduff, & Menges, 2015), this dissertation investigates the influential contexts around the broker and revisits the “human agency” issue in brokerage phenomena in the setting of corporate innovation.

Chapter One …

Spin-Orbit Interaction And Electron Spin Qubits In Silicon Quantum Dots, Rifat Ferdous

Open Access Dissertations

Spin qubits hosted in electrostatic quantum dots (QD) in Silicon (Si) are among the most promising candidates for building a large-scale quantum computer. Quantum information encoded in electron spins can survive longer in Si due to the scarcity of nuclear spin noise. We can also take advantage of the Si based nano-fabrication technology already in place for classical computers. Quantum computation has already been successfully demonstrated at small scale with Si QD spin qubits. Spin-orbit interaction (SOI) has previously been used to enable electrical manipulation of spins in other semiconductor materials. However, SOI is often ignored in Si as being …

Metaethical Mooreanism, Jonathan Fuqua

Open Access Dissertations

This dissertation is an attempt to apply the Moorean response to radical skepticism to moral skepticism. In a nutshell, I argue as follows. Assume that the following Moorean response to, say, BIV skepticism (the worry that I don’t know I’m not a brain in a vat) is roughly correct: “I know I have hands, so I’m not a BIV; any argument to the contrary must have a flaw somewhere.” If so, then such a Moorean should respond as follows to moral skepticism: “I know that recreational genocide is wrong, so it’s false that there are no moral facts, and that …

Design And Development Of Adaptive Intrusion Management For Cyber-Based Systems, Muhamad Felemban

Open Access Dissertations

With the growing Cyber-security threats to governmental and organizational infrastructures, the need to develop high resilient Cyber-Based Systems (CBSs) that preserve the security of data is becoming increasingly important. A prominent type of Cyber-attacks is intrusion attacks that aim at data tampering, which can impair the confidentiality and the integrity of data. Therefore, it is imperative to design a holistic intrusion management approach for CBSs.

In this dissertation, we address the challenges of designing and developing a resilient intrusion management system. In particular, we propose an adaptive data Partitioning-based Intrusion Management System (PIMS) that can endure intense malicious intrusion attacks …

Acute Effects Of Contractile Activity On Skeletal Muscle Exosomes, Ron T. Garner

Open Access Dissertations

Introduction: Skeletal muscle functions as an endocrine organ, and a key way to accomplish that is through exosomes. The internal budding of a multivesicular body (MVB) forms exosomes and contains mRNA, miRNA, and proteins. Through a multifaceted approach, the following three experiments were designed to better understand the effect of contractile activity on skeletal muscle MVB/exosome biogenesis and release.

Study 1: Exosome-related pathway response to acute exercise. Sedentary, lean, healthy male subjects (n=12) performed 45 min cycling (AEx), followed by single leg knee extensor exercise (A+REx). A biopsy was obtained prior to exercise and 1 hr post-exercise from each leg. …

Gnss/Ins-Assisted Multi-Camera Mobile Mapping: System Architecture, Modeling, Calibration, And Enhanced Navigation, Magdy Elbahnasawy

Open Access Dissertations

To date, due to some financial and technical constraints, camera-based mobile mapping systems with GNSS/INS unit onboard the platform are still the optimal option for most mapping applications. Therefore, a great deal of research has been conducted on developing an operational GNSS/INS-assisted single/multi-camera mapping system. However, to satisfy the needs of various mapping applications, there are still challenges that have to be addressed. Such challenges start with the selection and integration framework of sensors (cameras and GNSS/INS units) onboard different types of mapping platforms (i.e., UAV and wheel-based platforms). Another challenge is modeling and calibrating the GNSS/INS-assisted single/multi-camera mapping systems. …

Understanding The Adoption, Maintenance, Diffusion Of Urban Stormwater Management Practices, Yuling Gao

Open Access Dissertations

Urbanization increases stormwater volume and decreases infiltration capacity due to the impact of added impervious surfaces and reduced vegetation. Urban stormwater management practices (SMPs) employ control and treatment measures to mitigate water runoff and break down pollutants using a natural approach, which has proven to be effectively protecting the hydrological process of streams. Though a significant number of empirical studies identified the effectiveness of urban SMPs, a few studies have investigated individuals’ perceptions about the approach and factors that influence decision-making on its implementation. This dissertation is intended to investigate the adoption, maintenance, and diffusion of urban SMPs through mail …

Enzymatic Inhibition By Lignin During Second Generation Ethanol Production, Antonio Carlos Freitas Dos Santos

Open Access Dissertations

An important hindrance to commercialization of lignocellulosic ethanol is the high cost of enzymes. Reducing enzyme loadings is necessary to reduce costs. Knowledge of the inhibitors of these enzymes is necessary to better inform enzyme development and process design. Five factors have been identified: soluble inhibitors, solid lignin adsorption, product inhibition, mixing efficiency and oxygen deactivation of the enzymes that hydrolyze cellulose to glucose. These factors are intertwined and properly assessing them individually require the elimination of the others. Isolating each factor, however, has not been done throughout literature leading to lumped constants. Soluble inhibitors reduce conversion sharply leading to …

Polysulfide Mitigation At The Electrode-Electrolyte Interface: Experiments In Rechargeable Lithium Sulfur Batteries, Arthur D. Dysart

Open Access Dissertations

In the field of energy storage technology, the lithium sulfur battery is intensely studied in interest of its great theoretical gravimetric capacity (1672 Ah kg–1) and gravimetric density (2600 Wh kg–1). The theoretical performance values satisfy viability thresholds for petroleum–free electric vehicles and other emerging technologies. However, this elusive technology remains in the research sector due to a wealth of challenges resulting from its complex chalcogenide electrochemistry. The most infamous challenge remains the polysulfide redox shuttle, a phenomenon in which lithium polysulfide intermediates are produced as elemental sulfur S8 is reduced to lithium sulfide Li2S during the discharge cycle. Because …

The Theory And Practice Of Rhetorical Gaming For Composition Instruction, Jeffrey M. Gerding

Open Access Dissertations

In recent years videogames scholarship has grown from a small interest group within rhetoric and composition to a burgeoning interdisciplinary subfield. This growth has not been without problems or controversies, however, and on the whole there seems to be little consistency in either theory or practice when it comes to integrating games into composition curriculum. The purpose of this thesis is to examine a number of theories, concepts, procedures, and issues in the history of games and composition in order to suggest a possible direction for the future. To be clear, this is not an attempt to standardize a rule-governed …

Soundscape Ecology: Rich Contexts For Investigating Conservation Biology & The Effect Of Informal Environmental Experiences On Youth’S Conceptual Understanding, Interest And Identity Development, Maryam Ghadiri Khanaposhtani

Open Access Dissertations

Recent educational studies have shown increasing lack of interest and participation of youth (ages 10-14 years old) in various STEM (Science, Technology, Engineering and Mathematics) fields in the U.S. The decline in the number of youth choosing to study STEM fields in higher education and the resulting lack of STEM professionals in the society has drastic economic impacts. Therefore, it is critical to introduce youth to quality STEM education that engages them with science practices and triggers their interest and curiosity in order to increase their participation in those fields. To address this issue, the aim of this study is …

Lipid And Metabolite Profiling Mass Spectrometry Of Human Glioblastoma Using Mouse Xenograft Model, Soo Jung Ha

Open Access Dissertations

Glioblastoma (GBM) is the most common and malignant form of human primary brain tumor. Due to its extremely malignant and invasive nature, the mean survival period of GBM patients is only 12 to 15 months from diagnosis. GBM patients rely on current treatment options including surgery, radiation and chemotherapy. Unfortunately, these treatment options fail to improve quality of patients’ lives. Studies have shown that altered lipids and metabolites in GBM may play a critical role in chemo-resistance, cancer cell initiation and progression regulated by oncogenic signaling pathways. This research utilized multiple reaction monitoring (MRM) profiling mass spectrometry (MS) and desorption …

Baroque Modes Of Seeing: Reinventing Neo-Baroque In Contemporary Latin American Cinema, Liana Hakobyan

Open Access Dissertations

While the Latin American literary neo-baroque garnered significant attention, scholarship on its cinematic counterpart has been relatively scarce. What is more, existing studies situate this aesthetics within the anti-dictatorship contexts of the 1970s-80s, which contradicts major neo-baroque theories that view it as an ahistorical aesthetics relevant to Latin American modernities. “Baroque Modes of Seeing: Reinventing Neo-baroque in Contemporary Latin American Cinema” is a dissertation that addresses this gap in research and argues for the relevance of the neo-baroque in contemporary Latin American cinema. I engage texts by Severo Sarduy, José Lezama Lima, Alejo Carpentier, Serge Gruzinski, Irlemar Chiampi and others …

Characterizing Trade-Off Decisions In Student Designers, Molly Hathaway Goldstein

Open Access Dissertations

Decision-making and design in uncertain situations in which information is limited and goals are ambitious or conflicting are a part of common practices of engineers. Such abilities in engineering practices are important to develop for all students from elementary school through college and graduate school. An important aspect of decision-making in design are the trade-offs decisions designers make throughout a project. Trade-offs are a complex element of a decision, that involves weighing possible outcomes against their respective benefits and costs in areas such as aesthetics, cost, degree of safety, and various performance indicators. Making trade-off decisions is an effective design …

Differential Molecular Diffusion In Turbulent Non-Premixed Combustion: Power-Law Scaling, Modeling Requirements, And Flamelet Simulations, Chao Han

Open Access Dissertations

The significance of differential molecular diffusion (DMD) has been demonstrated experimentally and numerically in many studies. Despite the significance, the effort of modeling DMD in turbulent combustion is still inadequate, and assumptions of equal molecular diffusion and unity Lewis numbers are often made when modeling turbulent combustion. It is imperative to interrogate the physics of DMD in turbulent combustion to provide needed physical insights for the advancement of models for DMD. In this work, we examine DMD in turbulent non-premixed combustion and advance the flamelet models for incorporating DMD.

The effect of DMD in turbulent non-premixed flames is studied by …

Transient Liquid Phase Bonding For High Temperature Interconnects, John R. Holaday

Open Access Dissertations

Transient liquid phase bonding (TLPB) is a type of interdiffusion bonding between metals that has been proposed for a variety of electronic interconnect applications. TLPB has been studied as an alternative to other high temperature interconnect materials such as high-Pb solders. The goal of eliminating Pb and other toxic materials from electronics manufacturing processes, and most importantly, waste streams has been part of an ongoing effort internationally to improve the sustainability of electronics manufacturing. Pb containing solders have largely been eliminated from most consumer applications, but continuing exemptions for high-Pb solders have been provided by regulators due to the lack …

Gas-Phase And Condensed-Phase Studies Of Small Reactive Intermediates, Christopher William Haskins

Open Access Dissertations

Nitriles are an integral functional group in many chemical industries. A new methodology for the dehydration of amides to nitriles has been developed using a palladium catalyst. The reaction conditions are robust and able to tolerate a wide variety of functional groups and substrates. The substrate scope can be broken into 4 main types of substrates including: alkyl, aromatic, cinnamic, and α, β, δ, γ-unsaturated amides. Mechanistically, the amide goes through a water exchanging mechanism to generate acetamide in equal parts to the nitrile. Cyclopropanols are important precursors for the generation of beta-carbonyl radicals. In the presence of a single-electron …

Native Graph Support In Relational Data Systems, Mohamed S. Hassan

Open Access Dissertations

A variety of data management applications spanning various domains, e.g., social networks, transportation, and bioinformatics, have graphs as first-class citizens. Specialized graph databases can serve these applications to evaluate vital graph-traversal queries, e.g., shortest path and reachability queries. However, specialized graph databases are not as mature as the pervasive relational database systems. Although the literature has several proposals to process graph queries inside an RDBMS, none of these proposals process graphs natively inside an RDBMS for potentially better performance, which is particularly challenging due to the impedance mismatch between the relational and the graph models. Additionally, to scale for large …

Nonperturbative Methods For Quantum Field Theory: Holographic Wilson Loops And S-Matrix Bootstrap, Yifei He

Open Access Dissertations

In this thesis, we explore nonperturbative methods of quantum field theory through two topics: holographic Wilson loops and S-matrix bootstrap. In the first part, we study the holographic calculation of Wilson loops using Ad-S/CFT correspondence, which is a duality between a string theory in AdS space and a gauge theory living on the conformal boundary of the AdS space. Under this duality, the expectation value of the Wilson loop operator in the gauge theory at strong t’Hooft coupling limit is given by the area of a string worldsheet ending on a boundary curve defined by the shape of the Wilson …

Effects Of Per/Polyfluoroalkyl Substances On Larval Amphibians, Gary M. Hoover

Open Access Dissertations

Per/polyfluoroalkyl substances (PFAS) are a group of persistent organic pollutants of emerging concern. Widespread use, along with volatility of some PFAS, has led to global distribution in soils and surface waters. The chemical stability of these compounds assures persistence in the environment, with effects unknown to much of the chronically-exposed biota. Many toxicology studies implicate PFAS in disruption of the hypothalamus-pituitary-thyroid (HPT) axis, which is known to play a major role in control of metamorphosis in amphibians. Thus, amphibians represent a class of organisms that may be susceptible to sub-lethal effects of PFAS exposure.

Three main aims were accomplished to …

Digital Badges And Student Motivation In The Undergraduate Chemistry Laboratory, Sarah Hensiek

Open Access Dissertations

Laboratory courses have been the focus of much research and debate in the field of chemistry. One goal for the laboratory that is consistently cited by faculty is student learning of hands-on skills. Despite this, hands-on skills are rarely assessed in practice because to do so is resource intensive. Digital badges allow each individual student to demonstrate their proficiency in a hands-on lab skill while relieving the constraints associated with assessing individual students during a laboratory period. Previously at Purdue, digital badges were developed for the pipet, buret, and volumetric flask. These badges were shown to support student learning of …