Digital Commons Network^™

The Effects Of Online Mind Mapping On The Cognitive Outcomes Of Students And Their Perceptions In The Collaborative Prewriting Stage, Yen Thanh Hai Duong

Doctoral Dissertations

In language acquisition, writing is the most challenging skill that English learners must master. Students often struggle at the beginning of their writing process with idea generation. Due to students’ low academic achievement and their struggles, online mind mapping is suggested as a useful tool to support language students’ brainstorms and idea organization during the writing process. The purpose of this mixed-method study was to investigate how online mind mapping can help students collaboratively brainstorm and organize their ideas during the prewriting process. This study focused on the effects of online mind-mapping intervention on student academic writing performance and perceptions …

The Effectiveness Of Mind Maps As An Instructional Approach For Developing Critical-Thinking Skills And Dispositions: A Meta-Analysis, Carmen De Jesus

Doctoral Dissertations

Mind mapping is the most flexible visual learning and active instructional approach. It has many applications, such as brainstorming, taking notes, memorizing, and conceptualizing complex topics using associations between images and keywords, colors, and visuospatial characteristics. Students can elaborate mind maps individually and collaboratively, digitally or nondigitally. Teachers can also elaborate mind maps for studying purposes. This meta-analysis aims to investigate the effectiveness of mind mapping as an instructional approach for developing critical-thinking skills and dispositions. With 22 studies (20 of which are international) and 1,535 participants, all employing a quasi- experimental study design, this meta-analysis is a comprehensive exploration. …

From Novitiate To Classroom: A Case Study Of Catholic Teaching Sisters, Melissa Broome Ursin

Doctoral Dissertations

This study was conducted to understand the formation of the Sisters of the Presentation of the Blessed Virgin Mary, San Francisco and how their communal practices supported and sustained their vocation to educate in Catholic schools. As the number of women religious in the United States decline, their work of Catholic education is being continued by lay teachers who may not have experienced the robust formation of religious in teaching orders. This qualitative case study used archives and oral histories to uncover how Sisters were formed and sustained as Catholic educators through Sacred texts, practices of prayer, and communal life. …

Accessible Technology For All: A Content Analysis Of Ux Design In Mobile Websites And Applications, Christine A. Franco

Doctoral Dissertations

More and more, digital technologies are becoming the fabric of everyday life, imbuing almost every aspect of modern society. With an increasing reliance on technology to complete essential tasks for school, work, communication, health, finance, and more, there remain barriers to accessing these tools. These barriers are not just represented by the digital divide, the haves and have-nots, but in the myriad ways in which the technologies we use every day are difficult to use, complex, or simply inaccessible. This research study investigates the factors that impact the accessibility of technology, specifically for individuals with either temporary, situational, or permanent …

Discovery And Characterization Of Low Current Electrospray Modes For Mass Spectrometry: Applications For Femtoesi And The Enhancement Of Relative Ionization Efficiency, Nicholas Allen

Doctoral Dissertations

The analysis of analytes using electrospray ionization (ESI) and mass spectrometry (MS) has become a widely used tool for the detection and characterization of a wide class of chemical species. Because of its utilization for liquid phase sample and its application to a wide range of flow rates, ESI-MS can be coupled with liquid chromatography (LC) to offer additional separation, desalting, and sample pre-concentration prior to detection. Recent improvements in ESI performance have come from investigating ways to improve the ionization behavior of wide classes of analytes by reducing the liquid flow rate, initially generated droplet size, and ionization current. …

A Pathway To Light-Induced Assembly Of Polymer Nanoparticles, Anna Huebner

Doctoral Dissertations

Since the late 1980’s tissue engineering has become an important field in regenerative medicine. Tissue engineering aims to create scaffolds designed to mimic the extracellular matrix (ECM) of human tissue, which is a complex, heterogeneous system. While there are a variety of approaches for scaffold fabrication, it is difficult to mimic the heterogeneity of the natural ECM. NH BioMade proposed a tissue engineering scaffold design to address these limitations, where multi-lobed particles can be 3D-printed to form a scaffold, providing heterogeneity in pore size by the incorporation of different-sized multi-lobed particles. In order for particles to be 3D printed into …

Binary Neutron Star Mergers: Magnetohydrodynamics And Neutrino Physics Of General Relativistic Simulations Of Binary Neutron Star Mergers, Alexander Lee Knight

Doctoral Dissertations

Binary neutron star mergers are some of the most extreme events to happen in our universe. From observations of these mergers, we can obtain information about the properties of matter at densities much larger than those accessible within the solar system, as well on the origin of heavy elements. Studying these events poses challenges, so we use simulations to model the merger. State-of-the-art methods and models still have to make assumptions or simplifications, so new methods improving either the accuracy of the simulations, or reducing the computational cost are desired. My research contains three projects, aiming to improve simulations by …

Aspects Of Mirror Symmetry For Non-Fano Toric Varieties, Michael John Samuel Lathwood

Doctoral Dissertations

Correlation functions in the topological A-model can be computed with open Gromov-Witten invariants whereas the mirror topological B-model admits a simpler description in terms of period integrals. We first review preliminary material in Chapter 1. Then in Chapter 2 we use tropical geometry to construct the Duistermaat-Heckman measure for non-Fano toric varieties. This allows one to compute the asymptotic terms of period integrals. In Chapter 3 we solve the generalized Picard-Fuchs system for the Hirzebruch surfaces, and hence compute periods to all orders of the mirror complex structure moduli. Near the large complex structure limit point, we use toric degenerations, …

Essays On Macroeconomics And Market Failures, Bayarmaa Dalkhjav

Doctoral Dissertations

What are the macroeconomic consequences of market failure in the long and short runs? How do asymmetric information, externality, and lack of the rule of law contribute to resource misallocation, output, and the business cycle in an economy at the aggregate level? My research focuses on these research questions. Specifically, I explore the macroeconomic effects of asymmetric information, the external impacts of innovation decisions as a part of firm’s dynamic decisions, and the implications of corruption on the fluctuation of the business cycle.

In the first chapter, titled “Hidden Information as a Source of Misallocation: An Application to the Opioid …

A Simultaneous Test Of Explanatory Accounts Of The Reminiscence Bump Using Emotional Cueing And The Life History Timeline Method, Caglayan Ozdemir

Doctoral Dissertations

This dissertation explores the reminiscence bump phenomenon through an investigation of four theoretical accounts—cognitive, identity formation, cultural life scripts, and life stories. Through a novel combination of the life history timeline method and emotional cueing technique, factors proposed to explain the reminiscence bump—such as novelty, identity-relevance, commonality, and perceived-control of personal event memories—were directly measured across three life periods (Pre-Reminiscence Bump, Reminiscence Bump, Post-Reminiscence Bump). Findings indicate partial support for each account to varying degrees, with the life stories account demonstrating the strongest empirical evidence relative to the other accounts. Most factors were able to differentiate the reminiscence bump from …

Eco-Resonance At The Arctic's Edge: Unraveling Microbial Methane Mysteries And Quantifying Collaborative Research Challenges, Tamara Sade Marcus

Doctoral Dissertations

Lakes in northern latitudes, especially those formed in peatlands, play a critical role in global carbon cycling. They store a substantial amount of organic carbon (OC) in their sediments but remain a poorly understood component of the carbon cycle. Despite their significance, CH₄ emissions from lakes were once considered negligible in climate models. However, recent studies highlight their substantial contribution, prompting the need for their inclusion in climate models, yet uncertainties persist around the CH₄ contributions from these systems.

This dissertation delves into the microbial controls on CH₄ emissions from arctic lake sediments, focusing on Stordalen Mire in northern Sweden, …

Streamer Dynamics In Thunderstorm And Near-Ionospheric Environments, Jacob Koile

Doctoral Dissertations

Streamers are self-consistent ionization waves that are generated within an electric field. Since they were first proposed in the theory of spark breakdown developed in the 1930s by Raether, Loeb, and Meek [Raether, 1939; Loeb and Meek, 1940], they have demanded the attention of scientists across many different fields. They are crucial to the Earth environment because of their natural occurrence in the form of sprites, at near-ionosphere altitudes above a thunderstorm, and their proposed roles in the formation and propagation of lightning. % that can occur above a thunderstorm, or However, they also play a role in the human …

Asymptotic Spectral Analysis Of A Coupled Bending-Torsion Beam Energy Harvester, Chris Vales

Doctoral Dissertations

A piezoelectric energy harvester is a device that utilizes the properties of piezoelectric materials to convert mechanical strain energy into electric energy. The present work is concerned with the asymptotic spectral analysis of a piezoelectric harvester extracting energy from the mechanical vibration of a coupled bending-torsion beam. After placing the model in the appropriate operator setting, we prove that the addition of piezoelectric energy harvesting constitutes a weak perturbation of the underlying beam dynamics, in the sense that the model’s piezoelectric parameters do not appear in the first two orders of magnitude of the asymptotic approximation of the governing operator’s …

Can Gel Content In Emulsion Polymerization Be Optimized? Contributions Of Both Chemistry And Process On The Crosslinking Of Polymer Colloids., Zachary Hollins

Doctoral Dissertations

Environmental regulations on volatile organic compounds implemented in the European Union have highlighted the strengths of waterborne coatings and adhesives. Emulsion polymerization is a heterophase reaction in which an aqueous medium suspends polymer particles. Polymer colloids have diverse applications ranging from paper coatings, cosmetics, food additives, and pressure-sensitive adhesives, just to name a few. With such a wide range of applications, each latex requires a unique set of mechanical and chemical properties. One method used to control various mechanical properties is crosslinking, in which an insoluble “gel” is produced. Previous research by the Tsavalas group has revealed that alterations to …

Plasma Membrane Remodeling And Biochemical Mechanisms Underpinning Bacterial Persistence In Fractured Subsurface Shale, Chika Jude Ugwuodo

Doctoral Dissertations

During hydraulic fracturing, a water-based fluid containing proppants and several chemical additives is injected under high pressure into a ~2 km deep wellbore, to extend fractures in the underlying rock. This process introduces a host of microorganisms into the reservoir, some of which survive, persist for long periods of time and cause several problems including production of H2S, a corrosive toxicant and biofilm formation which clogs rock fractures. Over time, the bacterial genus Halanaerobium dominates the microbial community composition in many geologically distinct fractured formations. Our understanding of shale reservoir microbial dynamics remains limited despite extensive studies in the past …

From Garvey To King: How Jamaica Influenced The Us Civil Rights Movement, Charlotte Helen Richard

Doctoral Dissertations

“From Garvey to King: How Jamaica Influenced the US Civil Rights Movement” interrogates the influence of Jamaica on African Americans during the Long Freedom Movement. While many historians have focused on the influence of African American leaders on other countries, such as Martin Luther King, Jr.’s global impact or the inspirational leadership of Stokely Carmichael on the African diaspora, no scholars have yet examined the significance of Jamaican activism, ideologies, and actions on African Americans. “From Garvey to King” situates Jamaica as central to transnational Black Nationalist and Black liberation ideologies, from the bottom up. From grassroots organizing to every-day …

The Dynamic Measure Of Health Goals, Goal Achievement, And Who Succeeds At Their Goals, Hannah Lightcap

Doctoral Dissertations

This dissertation is divided into four parts. Part 1 includes the introduction to the dissertation. Part 2 describes the first study of the dissertation, the Goal Measurement study. This focuses on the development and evaluation of the Health Goals and Achievement Surveys; a survey measuring and evaluating health goals and their achievement. The Goal Measurement Study also offers validity information and reports the relationships between various personality traits and health goal achievement. Part 3 describes the second study of the dissertation, the Personality Predictors and Social Support Study which examines multiple psycho-social predictors of health goal achievement. Part 4 is …

Leveraging Genome Evolution To Address Questions Of Biological Function, Hannah Pare

Doctoral Dissertations

Advances in sequencing technology have facilitated a surge in the production of genome data for diverse animal species. Researchers are presented with the opportunity to create comprehensive phylogenomic datasets, which have previously not been feasible. Unfortunately, extracting biologically relevant information from such a large amount of data is time consuming and computationally expensive, often limiting the scope and possibility of such analyses. My Ph.D. research aims to establish a methodological framework for investigating questions of biological function using comparative genomic and phylogenetic methods. Using two different metazoan genomic datasets we demonstrate the wide-ranging applicability of this framework by addressing research …

The Aspirations Of The Youth Of South Sudan Towards Tertiary Technical Education, Peace, Development And Civic Engagements, Sunil Orathel

Doctoral Dissertations

South Sudan, the youngest nation in the world, gained independence on July 9, 2011, following many long years of civil war and untold human suffering. After a decade of independence and millions spent from international assistance, neither stability nor development have been secured in the country. Although primary education is improving, tertiary education, particularly tertiary technical education, is considered a neglected sector. This descriptive mixed-method study documents and analyzes 1,461 surveys and 60 interviews, capturing the aspirations of the secondary school youth and stakeholders across the nation of South Sudan towards tertiary technical education, peace, development and civic engagements. Historical …

The Experience Of Caregiver Burden And Burnout Among Resident Directors, Tanya Koroyan

Doctoral Dissertations

The goal of this study was to understand the experiences of caregiver burden and burnout for Resident Directors (RDs). RDs live on campus and support students through traumatic experiences by serving in an “on-call” capacity. Student emergencies that RDs respond to include mental health concerns, sexual violence and sexual harassment, suicidal ideation, self-harm, grief, physical assault, etc. There is little research on understanding this work's experience and potential long-term implications.

Through a constructivist-interpretivist research paradigm and phenomenological qualitative methodology, nine interviews took place with individuals who had previously been RDs at Bay Area University, a large public institution in the …

The Relationship Between Situated Reading Motivation And Perception Of The Learning Environment For Adolescent Students, Travis Vandervelden

Doctoral Dissertations

Reading proficiency is particularly crucial for adolescent students who are expected to adopt and approximate a multitude of authentic literacy practices in several different content areas within the span of a single school day. A large number of adolescent students are failing to master basic levels of reading, and are thus uniquely disadvantaged in secondary schools, where reading is not only more complex, but teachers also spend less time teaching students how to read. Reading motivation has been a focus of research to address the lack of reading proficiency in classrooms. An understudied area within this field of research is …

Blow-Spun Hybrid Pcl-Peo/Hnts Scaffolds With Enhanced Biological And Mechanical Properties, Meichen Liu

Doctoral Dissertations

With the development of technology and engineering, nanotechnology has been a multidisciplinary scientific field applied in nearly all science areas, including medicine, genetics, food industry, robotics. In this respect, nanomedicine has gained increasing attention and been a useful, effective therapy for cancer diagnosis, gene transfer, and drug delivery. To design an ideal nano drug delivery system with controlled drug releasing and improved encapsulated drug’s pharmacokinetic and pharmacodynamic profiles, hydrogels and polymer composites have witnessed increased research interest during the last decades. Recently, numerous polymers have been studied to fabricate the ideal wound dressing with biocompatibility, biodegradability, porous structural, and suitable …

Development Of An Integrated Workflow For Nucleosome Modeling And Simulations, Ran Sun

Doctoral Dissertations

Nucleosomes are the building blocks of eukaryotic genomes and thus fundamental to to all genetic processes. Any protein or drug that binds DNA must either cooperate or compete with nucleosomes. Given that a nucleosome contains 147 base pairs of DNA, there are approximately 4^147 or 10^88 possible sequences for a single nucleosome. Exhaustive studies are not possible. However, genome wide association studies can identify individual nucleosomes of interest to a specific mechanism, and today's supercomputers enable comparative simulation studies of 10s to 100s of nucleosomes. The goal of this thesis is to develop and present and end-to-end workflow that serves …

Selective Targeting Of Microglia By Quantum Dots And Green Synthesis Of Metal Organic Biohybrids; Applications In Dynamic Cell And Assay Systems, Navya Uppu

Doctoral Dissertations

Neurological disorders are the leading cause of physical and cognitive disability across the globe, currently affecting approximately 15% of the worldwide population. Part of the glioma microenvironment are microglia, resident immune cells of the CNS that were thought to be involved in the pathogenesis of diverse neurodegenerative diseases. Though it remains uncertain what triggers microglial activation in these disorders, targeting and tracking microglial functions using nanotools like Quantum Dots (QDs) could help us elucidate them in such neurological diseases. This research focuses on the comparative study of different QDs formulations and their selective uptake by brain microglia in primary cultures …

Development And Characterization Of Injectable, Cell-Encapsulated Chitosan-Genipin Hydrogels, Tyler R. Priddy-Arrington

Doctoral Dissertations

Over 150,000 patients undergo lower extremity amputation every year in the United States, most commonly caused by complications due to diabetes mellitus, peripheral vascular disease, and trauma. Diseased or damaged tissues that are unable to naturally repair themselves must either be fully removed or replaced, otherwise the injuries can lead to further complications such as infection or death. Tissue resection and amputation, as forms of removing damaged tissue, are not favorable to patients as they can cause pain, reduce mobility, and negatively impact quality of life. However, replacing lost or damaged tissues with donor tissues carries the risks of tissue …

In Situ High Temperature Fiber-Optic Raman Sensor For Industrial Applications, Bohong Zhang

Doctoral Dissertations

"Continuous casting in steel production uses specially developed oxyfluoride glasses (mold fluxes) to lubricate a mold and control the solidification of the steel in the mold. The composition of the flux impacts properties, including basicity, viscosity, and crystallization rate, all of which affect the stability of the casting process and the quality of the solidified steel. However, mold fluxes interact with steel during the casting process, resulting in flux chemistry changes that must be considered in the flux design. Currently, the chemical composition of mold flux must be determined by extracting flux samples from the mold during casting and then …

Design, Synthesis, And Characterization Of Complex Chalcogenides For Energy Storage And Energy Conversion Applications, Srikanth Balijapelly

Doctoral Dissertations

"Through this investigation, complex chalcogenides with the combination of main group metals, transition metals, and rare earth metals have been synthesized using the building block approach and their structure-property relationships are evaluated. The main emphasis of research is on rationally designing new materials for applications in sodium and lithium ion conducting solid electrolytes, cathodes, thermoelectrics, and nonlinear optics. Along with the experimental studies, theoretical calculations are also employed to better understand the physicochemical properties of the synthesized compounds.

The first part of the research will discuss designing alkali ion containing complex chalcogenides using the building block approach. This investigation resulted …

Accurate And Time Efficient Signal Integrity And Power Integrity Modeling Of High-Speed Digital Systems, Chaofeng Li

Doctoral Dissertations

"Signal integrity (SI) and power integrity (PI) play an important role in the modern high-speed digital system design, which are closely related to the printed circuit board (PCB) dielectric material property, the PCB interconnect performance, and the power delivery network (PDN) on PCB. Generally, the full-wave simulation is used to accurately analyze and evaluate the designed PCB. But full-wave simulation is not a good option for the complex PCB structure with high aspect ratio, for example, PCB vias, and PDN, which will require significant computing time and storage resources. Equivalent circuit models have been developed to efficiently predict the electrical …

In Situ Infrared Thermographic Inspection In Additive Manufacturing, Tao Liu

Doctoral Dissertations

"Laser Powder Bed Fusion (LPBF) is a key technique in metal additive manufacturing and has undergone extensive research over the past few decades. It enables the fabrication of complex geometries directly from digital design models. The solidification process in LPBF is heavily influenced by the characteristics of the powder layer, including its thickness and thermal transport properties. Additionally, the performance of the printed part is impacted by the temperature history during solidification and the final residual stress field. While these topics have been the focus of many studies, almost all research has concentrated on ex-situ measurement and testing. These ex-situ …

Enabling Improved Hand Function In Disabled Individuals Via Intention Estimation And Suppression Of Disrupted Central Drive, Hendrik Adriaan Dewald

Doctoral Dissertations

No abstract provided.