Digital Commons Network^™

Electrical Characteristics Of In-House Produced Micro/Nanodielectrics, Dewan Mahmudullah

Graduate Theses and Dissertations (2019 - present)

Dielectric characterization is very important across a wide range of applications, including the design and optimization of capacitors, electrical insulation, and electronic devices. It plays a vital role in providing valuable insights for material selection, performance evaluation, and the development of advanced dielectrics. The permittivity of dielectrics is a fundamental property of dielectric materials that quantifies their ability to store and dissipate energy in the presence of an electric field. Studies for developing advanced dielectrics and accurate measurements of the dielectric constant are essential for understanding and optimizing the performance of various electrical and electronic systems. The objective of this …

Evaluating The Impact Of Oyster Reef Breakwaters On Hydrodynamics, Morphodynamics, And Sediment Transport Using Xbeach, Tabassum Islam

Graduate Theses and Dissertations (2019 - present)

Alabama Port is a unique marsh and sandy beach shoreline. Since the 1950s, substantial erosion has occurred along this shoreline due to storms, wind-generated waves, and ship wakes. This research focuses on evaluating the effect of oyster reef breakwaters on wave height attenuation and sediment stabilization through numerical modeling (XBeach) under three different synthetic storm scenarios coupled with three unique sea level rise projections near Alabama Port. This has been accomplished by comparing a with and without project condition using XBeach in a two-dimensional (2D) mode by analyzing wave height, velocity, and cumulative bed-level changes at the study site. The …

Interactions Between Sediment Mechanical Structure And Infaunal Community Structure Following Physical Disturbance, William Cyrus Roger Clemo

Graduate Theses and Dissertations (2019 - present)

Shallow, river-influenced coastal sediments are important for global carbon storage and nutrient cycling and provide a habitat for diverse communities of invertebrates (infauna). Elevated bed shear stress from extreme storms can resuspend, transport, and deposit sediments, disrupting the cohesive structure of muds, and sorting and depositing sand eroded from beaches. These physical disruptions can also resuspend or smother infauna, decreasing abundances and changing community structure. Infaunal activities such as burrowing, tube construction, and feeding can impact sediment structure and stability. However, little is known about how physical disturbance impacts short and long-term sediment habitat suitability and whether disturbance-tolerant infauna influence …

Perceptions Of College Students With Disabilities Regarding The Impact Of Instructional Supports On Academic Success, John O. Oreye

Graduate Theses and Dissertations (2019 - present)

This qualitative phenomenological study explored how college students with disabilities (SWDs) accessed accommodations from their universities and their perceptions of service delivery by university faculty and staff. An additional purpose of this study was to seek the type and effectiveness of accommodations received by college SWDs. I recruited participants through the disability resource office of a regional university in the Southeastern United States. The diverse population studied was college SWDs, and the phenomenon of interest was their experience with receiving accommodations from their university. The seven participants who took part in interviews identified as college students with a disability that …

Initiation Criteria For The Onset Of Geomagnetic Substorms Based On Auroral Observations And Electrojet Current Signatures, Mayowa Michael Kayode-Adeoye

Graduate Theses and Dissertations (2019 - present)

In recent years, several substorm onset criteria have been developed, either from auroral observations (many authors) or from auroral electrojet properties such as those described by (Forsyth et al., 2015; Maimaiti et al., 2019; Newell & Gjerloev, 2011; Partamies et al., 2011) The different criteria are being investigated using a low order physics model of the magnetosphere called WINDMI (Spencer et al., 2009) and inferences are being made in line with the WINDMI model. The model variables will be compared with the criteria for substorm onset proposed by examining the SML index.

The WINDMI model uses solar wind and IMF …

Examining The Efficacy Of Using Irt As An Nde Method For Cfrp And Ztcfrp Composites, William Wyatt Taylor

Graduate Theses and Dissertations (2019 - present)

A film adhesive is commonly used to form the bond-line between composite parts. The bond-line's quality and performance can be affected by defects such as voids, impurities, and agglomerations. Identifying these defects is possible with non-destructive evaluation testing (NDE). In this thesis, the joule-heating effect (JH) through carbon nanofiber (CNF) and carbon nanotube (CNT) modified film adhesive bonded to control carbon fiber reinforced polymer (CCFRP) was used along with infrared thermography testing (IRT) for bond-line defect inspection as a preliminary study. Due to the difference in the electrical conductivity between the modified epoxy and the defect, JH can cause a …

Gravel Conveyance System: An Evaluation On E. Coli Removal Capabilities, Madison Grace

Graduate Theses and Dissertations (2019 - present)

In many rural, low-income communities such as the Black Belt of Alabama, there is a lack of wastewater infrastructure and solutions leaving homeowners non-compliant to state and federal law and with potential health risks on their property. New regulations have allowed for onsite, surface discharge for single family homes that are not connected to a centralized sewer or large flow development. These new regulations also contain strict disinfection criteria for the treated wastewater that will be discharged. A low-cost and low-maintenance treatment system that provides adequate disinfection is necessary to allow homeowners to take advantage of the new opportunity for …

Biological Age Mediates The Effects Of Perceived Neighborhood Problems On Heart Failure Risk Among Black Persons, Ganga Bey, James Pike, Priya Palta, Anthony Zannas, Qian Xiao, Shelly-Ann Love, Gerardo Heiss

Faculty, Staff and Student Publications

OBJECTIVE: We assessed whether biological age, measured by the epigenetic clock GrimAge, mediates the association of objective and subjective neighborhood disadvantage with incident HF among Black persons.

METHODS: Participants were 1448 self-reported Black adults (mean age (standard deviation, SD) = 64.3 (5.5)) dually enrolled in two community-based cohorts in Jackson, Mississippi, the ARIC and JHS cohorts, who were free of HF as of January 1, 2000. Incident HF events leading to hospitalization through December 31, 2017, were classified using ICD-9 discharge codes of HF. Multilevel age- and sex-adjusted Cox causal mediation models were used to examine whether biological age (at …

Design Of An Fgf-1-Fgf-2 Heterodimer Variant With Enhanced Stability And Cell Proliferation Activity, Nicholas Alan Pohlman

Chemistry & Biochemistry Undergraduate Honors Theses

The FGF-1 subfamily, composed of FGF-1 and FGF-2, assists in broad health-related processes such as cell proliferation and angiogenesis respectively.^1,2 The subfamily shows promising signs as a therapeutic, however, the inherent thermal instability leads to a low half-life in vivo.³ To assist in improving the stability, FGF-1 and FGF-2 were connected via a 12-residue glycine linker ultimately producing a heterodimer. This heterodimer was further examined to discover its novel properties. Inspiration for this project was drawn from previous research which performed five mutations on FGF-1 ultimately improving stability in the protein complex. In addition to these five …

Early Detection Of Virality In Chinese-Language On Youtube Focus On Comments, Yulin Zeng

Computer Science and Engineering Master's Theses

Predicting the popularity of the YouTube video-sharing site in its early stages is crucial for journalists and researchers, as it helps them uncover disinformation. In addition, research on the number of comments in news and comments has always been an academic topic that has attracted much attention. These Youtube political commentary and News channels that use Chinese as the primary language have a strong influence on the first generation of Chinese immigrants in the United States. However, under our monitoring, we found that it is difficult for these videos to appear in the viral video list defined by YouTube API. …

Temporal Dynamics Of Faculty Hiring In Mathematics, Cody Fitzgerald, Yitong Huang, Katelyn Plaisier Leisman, Chad M. Topaz

Mathematics Sciences: Faculty Publications

University faculty hiring networks are known to be hierarchical and to exacerbate various types of inequity. Still, a detailed, historical understanding of hiring dynamics lacks in many academic fields. We focus on the field of mathematics, analyzing over 120,000 records from 150 institutions over seven decades to elucidate the temporal dynamics of hiring doctoral-granting (DG) faculty at the individual and departmental levels. We demonstrate that the disparity between the number of mathematics Ph.D.s awarded and the number of DG faculty positions filled has grown over time. Even institutions with the best records of DG faculty placement have experienced a temporal …

Androgen Receptor: A Complex Therapeutic Target In Breast Cancer, Sarah Tinuade Asemota

Theses and Dissertations (ETD)

Breast cancer is classified based on the expression of three markers estrogen receptor (ER), progesterone receptor, and human epidermal growth factor receptor (HER2). Breast cancers that express these targets are classified as hormone receptor (HR) positive breast cancer and the tumors that lack the expression of these markers are classified as triple negative breast cancer (TNBC). Though HR-positive breast cancer is treated with hormonal and cyclin-dependent kinase 4/6 targeted therapies, the cancer relapses and becomes resistant to the treatment options. Androgen receptor (AR) that is expressed in over 90\% of ER-positive breast cancer and in 20\% of TNBC is a …

The Role Of Tcr Engagement Strength In Antitumor Cd8 T Cell Exhaustion, Xin Lan

Theses and Dissertations (ETD)

Durability of an antitumor immune response is mediated in part by the persistence of progenitor exhausted CD8 T cells (Tpex). Tpex serve as a source for the pool of effector T cells that tend to have a short lifespan or eventually become dysfunctional in uncleared tumors. In contrast to the short-lived feature of their daughter cells, Tpex are able to preserve their quantity and developmental potential through a process of self-renewal. Previous research has demonstrated that Tpex can even self-renew in the absence of their cognate antigen. However, it remains unknown how T cell receptor (TCR) engagement impacts the self-renewal …

Preparing Teaching Assistants To Facilitate Course-Based Undergraduate Research Experiences (Cures) In The Biological Sciences: A Call To Action, Erin Shortlidge, Amie M. Kern, Emma Goodwin, Jeffrey T. Olimpo

Biology Faculty Publications and Presentations

Course-based undergraduate research experiences (CUREs) offer an expanding avenue to engage students in real-world scientific practices. Increasingly, CUREs are instructed by graduate teaching assistants (TAs), yet TAs may be underprepared to facilitate and face unique barriers when teaching CUREs. Consequently, unless TAs are provided professional development (PD) and resources to teach CUREs effectively, they and their students may not reap the assumed benefits of CURE instruction. Here, we describe three perspectives – that of the CURE TA, the CURE designer/facilitator, and the CURE student – that are collectively intended to inform the development of tentative components of CURE TA PD. …

Language As The Catalyst Between The Relationship Of Subordinates' Communicative Competence And Supervisors' Communicative Behavior: A Canonical Correlation Analysis, Lindsey N. Tan

Journal of English and Applied Linguistics

Communicative competence could be understood as the ability to effectively use language in different contexts, and one of these contexts is the intricate framework of the supervisor-subordinate relationship (SSR). However, studies on SSR are mostly based on supervisors’ communicative behavior (SCB), and there is a scarcity of studies that investigate the role of subordinates’ organizational communication competence (SOCC) on SSR. Consequently, this study aims to investigate the relationship between SOCC and SCB in the SSR framework. Using the canonical correlation analysis, two sets of facets were used to analyze the relationship. The first set is the SOCC, which includes communicative …

Effect Of Multiple Machine Configurations And Wall Thickness On Microstructure And Microhardness Of Laser Powder Bed Fusion (L-Pbf) Additively Manufactured Heat-Treated Inconel 718 Products, Anannya Doris

Open Access Theses & Dissertations

This research examined thin section prototypes having seven nominal thicknesses ranging from 0.1 to 2.0 mm, composing a series of geometric feature build plates manufactured by multiple laser powder bed fusion (L-PBF) machine configurations. The build plates and thin section feature prototypes underwent a full heat treatment cycle per established standards: anneal at 1066°C, SR+HIP at 1163°C, and fully treat-treated by combining SR+HIP+solution treatment at 1066°C and double aging treatment at 760°C and 680°C, respectively. The fully heat-treated (FHT) Inconel 718 wall specimens were sectioned from 16 distinct geometric feature build plates constructed on 15 different L-PBF machines. The thin …

Addressing Current Security And Privacy Limitations In Iot Applications With Differential Privacy, Nicholas Anthony Lopez

Open Access Theses & Dissertations

Over the last decade, billions of devices have been developed to run on the Internet of Things (IoT) domain. IoT has been embedded into everyday tasks so much that the number of devices has outpaced the global population. Some of the main areas of IoT include healthcare, industry, communications, transportation, logistics, and environmental awareness, to name a few. With this greater demand for devices comes an even greater demand for privacy and security. The three main principles of security include confidentiality, integrity, and availability. However, there is no “one size fits all” solution regarding privacy or security. When applied across …

Additive Manufacturing Of Composites For Sensing And Harsh Environments Application, Md Sahid Hassan

Open Access Theses & Dissertations

Composite materials are made by combining two or more materials, such as fibers and resins to create a material system that has improved mechanical and physical properties compared to its individual components. The use of 3D printing technology in composite manufacturing allows for the creation of complex and custom shapes with precise control over the placement of the materials. This makes it possible to create composite parts with enhanced performance characteristics and reduced weight. The work presented in this dissertation lies in the design and development of highly flexible impact propagation sensor through material extrusion 3D printing technique. By using …

Evaluation Of Inconel 718 Laser Powder Bed Fusion Angled Wall Artifact, Laura Itzel Marquez

Open Access Theses & Dissertations

This research investigates the mechanical properties and microstructural characteristics of Inconel 718 specimens fabricated using different additive manufacturing (AM) systems, focusing on the influence of build orientation. A total of 16 samples were constructed at 45, 60, and 90 degrees to the build platform and analyzed to ascertain variations in mechanical strength, encompassing elongation at break, ultimate tensile strength (UTS), yield stress, and hardness. The comprehensive statistical analysis employs robust methods to quantify the effects of printing parameters on the performance of the builds, thereby identifying the most influential factors in AM processes. Additionally, microstructural analysis through advanced imaging techniques, …

Design And Customization Of 3d Printers For Advanced Materials Printing, Alan Omar Loera Martinez

Open Access Theses & Dissertations

This research is divided into two sections. The first section discusses modificationsperformed to two commercial printers. The first printer was modified from a thermoplastic polymer printer to a pneumatic printer by taking away its heating elements and print head. Circuits were directed to pneumatic dispensing system as well in order to automate the process. The second printer had mechanical modifications performed to be a multi-material gradient printer by controlling two stepper motors through an electronics board. Through code, a mixing ratio changed the motors' rotations to provide the desired gradient of two different materials. The second section of the present …

Optimizing Remote Sensing Approaches For Dryland Carbon Flux Estimation, Kamal Nyaupane

Open Access Theses & Dissertations

Dryland ecosystems account for 40% of the global land surface area and play a vital role in the global carbon cycle. Gross Primary Productivity (GPP) is crucial for carbon exchange between ecosystems and the atmosphere, serving as a fundamental determinant of the carbon balance. However, precise modeling of GPP in terrestrial ecosystems, especially drylands, remains a complex challenge. This research utilizes a decade long spectral reflectance dataset acquired with a robotic tram system to estimate GPP using Random Forest model. The research exceled in capturing the complex spatio-temporal dynamics of the study site. Notably, the RF model exhibited best performance …

Enhancing Power System Flexibility Through Efficient Integration Of Facts And Electric Vehicles, Izaz Zunnurain

Open Access Theses & Dissertations

The global transition towards a cleaner and sustainable energy landscape has led to the integration of renewable energy sources and electric vehicles (EVs) into the modern power system, along with their complexities. Due to the high penetration of renewable energy sources and rapid growth of EVs, the power grid often experiences congestion, increasing the overall operating cost of the power system and directly jeopardizing the power stability and quality of the grid. A flexible and resilient power infrastructure that can accommodate the intermittency of renewable energy sources and the adoption of EVs is very much required to ensure the reliability …

The Perpetuation Of Hiv Risk In Latinx Immigrations: A Cross-National Perspective, J. M. Aleman

Open Access Theses & Dissertations

Research indicates that migration is a social determinant of health that increases the risk of acquiring HIV. What is less understood, however, are the pathways through which immigration influences HIV risk. This study employed a cross-national perspective and utilized a social determinants of health framework to understand how structural factors, such as economic conditions and immigration policies and their enforcement, influence HIV risk among migrants. While mobility, migration and displacement are associated with increased HIV risk, they are not inherently the cause but rather a condition under which vulnerability is increased indicating that other distal, upstream, or structural forces are …

Synthesis And Characterization Of Acetaminophen-Derived Nanoparticles: A Novel Approach To Inhibit Fibril Formation, Hannia Elena Mendoza-Dickey

Open Access Theses & Dissertations

In the realm of nanotechnology, nanoparticles (NPs), have garnered significant notoriety in recent scientific research due to their unique physical and chemical properties, such as fluorescence emissions, nanoscale dimensions (typically <1000 nm), ease of surface modification, and biocompatibility. Nanoparticles have shown their potential across a variety of areas, including advanced industrial applications and cutting-edge biomedical research. Considering their cost-effective synthesis, they have shown promise as therapeutic agents for a variety of bioimaging and biomedical applications. This thesis describes the synthesis and detailed analysis of acetaminophen-derived nanoparticles. Techniques such as Dynamic Light Scattering (DLS), Thioflavin T (THT) assay, Attenuated Total Reflectance Infrared Spectroscopy (ATR-IR), 1H NMR spectroscopy, and Ultraviolet-Visible Spectroscopy (UV-VIS) were utilized for structural and functional assessments. Acetaminophen derived nanoparticles (ANPs) exhibit potential to hinder the amyloidogenic conversion of soluble amyloid-forming proteins into their toxic form. The novelty of this research focuses on the utilization of chemical structures capable of traversing the Blood Brain Barrier (BBB) to mitigate xenotoxicant-induced neuronal damage, a notable contributor to neurodegenerative disorders. This thesis describes the synthesis and characterization of acetaminophen derived-nanoparticles (ANPs). Our nanoparticles possess anti-amyloidogenic properties as evidenced by their ability to disrupt in the soluble-to-toxic trajectory of HEWL. The prevalence and evolution of amyloid fibrils are consistent features in the pathology of neurodegenerative diseases such as Parkinson's disease (PD), Alzheimerâ??s Disease (AD), and Huntingtonâ??s Disease (HD), as well as metabolic disorders like Type 2 diabetes (T2D). The relationship between amyloidogenic pathways and these disorders highlights the imperative for enhanced understanding and the formulation of specific therapeutic interventions.

The Role Of Media In Shaping Chinese Narratives On National Rights Images, Gloria Andrea Baca

Open Access Theses & Dissertations

The research project below that provides a qualitative analysis of the Chinese Mediaâ??s role in shaping national rights images. The research conducts an analysis on human rights abuse allegations against China that directly target the Uyghur population residing in the Xinjiang Providence. This paper conducts an analysis of seven white papers, which are government issued responses presented by the CCP, to interpret which types of the four narrative buildings strategies listed are utilized when responding to the accusations. The basis of this paper establishes that when the Chinese government address allegations of abuse towards the Uyghur population, they will respond …

Addressing Binational Issues For Water Quality Along The United States-Mexico Border And The Use Of The 1944 Water Treaty As A Means For Developing Transboundary Aquifer Agreements, Gilbert Anaya

Open Access Theses & Dissertations

The water resources of the United States (U.S.) and Mexico are under tremendous pressure due to declining reservoir levels, changes in climate, and prolonged drought. The U.S.-Mexico border region relies on the Rio Grande and Colorado River, and shared groundwater resources that are transboundary in nature. These resources are vital to the U.S.-Mexico border and are susceptible to drought that leads to reduced flow and allocation to the users. In addition, there are impacts to water quality caused by return flows and from failing sanitation infrastructure. In this study, we focus on 1) the contribution of springs in an area …

An Optimization Procedure To Design Nozzle Contours For Hypersonic Wind Tunnels, Omar Antonio Dominguez

Open Access Theses & Dissertations

Supersonic wind tunnels allow scientists and researchers to evaluate and analyze the behaviors of objects under real-life conditions when subjected to supersonic speeds. One of the main complexities when building a wind tunnel is the design of the convergent-divergent nozzle that is used to produce high-speed and high-quality flows. To achieve supersonic speeds, this nozzle adopts a specialized approach that incorporates the complexities of flow compressibility. The compressible effect is accurately evaluated using isentropic relations, allowing for precise determination of stagnation pressure and temperature, and static pressure and temperature relevant to the desired Mach number. Isentropic equations used to define …

Design And Implementation Of Laser Beam Measurements At The Extents Of The Build Platform: Impact Of Beam Location On Melt Pool Geometry, Alexandra Hernandez

Open Access Theses & Dissertations

Laser powder bed fusion (LPBF) is a form of metal additive manufacturing that enables the development of complex parts that cannot readily be made with traditional manufacturing methods. The process utilizes a tightly focused laser beam to selectively melt and fuse layers of powdered metal to create a 3-D part.LPBF is a promising technology, but there are barriers to its adoption in most industries. Mainly, it is difficult to qualify these parts for use, since they are prone to processing defects and part-to-part variation. One source of this is part position on the building plane, especially for multi-part builds where …

Communication Security In Smart Home Iot And Scada Applications, Ismael Holguin

Open Access Theses & Dissertations

The advancements in technology have enabled continuous integration of consumer electronicdevices and sensors to the Internet, creating Internet of Things (IoT) environments for various applications. IoT communication protocols play a significant role in these environments and greatly vary depending on the type of application. In this work, we consider communication protocols in Smart Home IoT and SCADA environments, focus on their security features, and investigate methods to enhance their security. Most of these communication protocols were designed to meet specific communication goals, where security was not a requirement or priority during design. However, due to a shift in the security …

Co2-Dependent Nanoscale Organization In Bulk And Interfacial Carbon Dioxide Capture Liquids Elucidated Using X-Ray Scattering, Daniel Eduardo Moran

Open Access Theses & Dissertations

The pressing need to control carbon dioxide emissions has propelled extensive research efforts employing a variety of approaches across the globe. In flue-gas recovery of CO2, the water-lean amine-based solvent N-(2-ethoxyethyl)-3-morpholinopropan-1-amine (2-EEMPA), has shown exceptional performance. Recent studies show that 2-EEMPA exhibits intermediate-range order (IRO), beyond the first nearest neighbor length scale, consisting of tetrameric clusters. In view of the need to find solutions for direct air capture (DAC) of CO2, this system may represent a critical linkage in a DAC strategy, yet structural insights on EEMPA's behavior at solid surfaces are still lacking. To this end, we applied the …