Digital Commons Network^™

Materials And Process Design For Ceramic Fused Filament Fabrication (Cf3) Of Hydroxyapatite., Kavish Sudan

Electronic Theses and Dissertations

Ceramic fused filament fabrication (CF3) enables the fabrication of highly customizable ceramic parts at relatively lower costs compared to other AM technologies. Advanced ceramics, having specific or niche applications, call for a high level of accuracy to meet the performance requirements. For achieving the desired level of accuracy in any manufacturing process, it is important to know the effect of involved parameters at different stages of fabrication. CF3 has been around for a while but there has been a severe lack of literature dealing with understanding the effect of process parameters on the final part properties. In this study, Hydroxyapatite …

Modeling Driver Distraction Mechanism And Its Safety Impact In Automated Vehicle Environment., Song Wang

Electronic Theses and Dissertations

Automated Vehicle (AV) technology expects to enhance driving safety by eliminating human errors. However, driver distraction still exists under automated driving. The Society of Automotive Engineers (SAE) has defined six levels of driving automation from Level 0~5. Until achieving Level 5, human drivers are still needed. Therefore, the Human-Vehicle Interaction (HVI) necessarily diverts a driver’s attention away from driving. Existing research mainly focused on quantifying distraction in human-operated vehicles rather than in the AV environment. It causes a lack of knowledge on how AV distraction can be detected, quantified, and understood. Moreover, existing research in exploring AV distraction has mainly …

Design Of A 300cm2 Pemfc Stack With Force And Cfd Simulation To Optimize Flow Channels, Gasket Design, And Clamping Forces., Robert M. Ench

Electronic Theses and Dissertations

Proton exchange membrane fuel cells are important to the future of green energy as hydrogen can be made with green technologies and store energy for later use. Fuel cells can efficiently convert the hydrogen to electricity as needed. This study uses Solidworks simulation to make design improvements to the fuel cell before the prototype build stage of testing; this saves money and time by reducing the prototype builds needed.

In this study, a multi-channel serpentine design with two outlets versus a single outlet is evaluated using CFD to investigate pressure drop. Lower pressure drops are desirable as less energy input …

Synthesis, Crystal Structure And Ionic Conductivity Of Ruddlesden-Popper Oxide Materials: Effects Of Ionic Radii And Defects On Lithium-Ionic Conductivity., Selorm Joy Fanah

Electronic Theses and Dissertations

Layered perovskite oxides of the Ruddlesden-Popper (RP) type structure can be good lithium-ion conductors for solid electrolyte applications in all-solid-state batteries, due to the large gap separating octahedral layers which can be useful pathways for Li-ion conduction. However, little work has been done on their lithium-ion transport properties in these materials despite their interesting structural properties. This work highlights the synthesis and study of the ionic conductivities in a series of n = 2 and 3 Ruddlesden-Popper oxides, as part of an ongoing investigation in search of alternative solid electrolyte materials. Several different strategies were employed for the enhancement of …

Towards Long Term Colloid Suspension In A Vertically Rotated System., Md Mahmudur Rahman

Electronic Theses and Dissertations

Within a colloidal suspension gravity may compromise the observation of governing physical interactions, especially those that are weak and/or take significant time to develop. Conducting the experiment in a long-term microgravity environment is a viable option to negate gravitational effects, though significant resources are required to do so. While it may not be possible to simulate long-term microgravity terrestrially, particles can resist quick sedimentation in a confined suspension system rotating vertically with appropriate rotation speed. The goal of the investigation is to demonstrate the existence of long-term particle suspension regime for a certain colloidal suspension while characterizing colloidal behavior due …

The Role Of Sphingolipids In Aki And The Progression To Ckd: Potential Therapuetic Targets., Nicholas A. Hoffman

Electronic Theses and Dissertations

Acute Kidney Injury (AKI) is most simply defined as a rapid decline in kidney function over a period of hours to days. There is currently a lack of effective treatment options for patients with AKI, highlighting the need to identify new therapeutic targets. Sphingolipids play a number of roles in different models of AKI, suggesting they could be promising future targets for treating kidney injury. Specifically, sphingosine-1-phosphate (S1P) and its receptors (S1PRs) have been implicated in numerous inflammatory disorders and models of AKI. The purpose of this review is to better characterize the role of S1P receptors in models of …

Local Feature Selection For Multiple Instance Learning With Applications., Aliasghar Shahrjooihaghighi

Electronic Theses and Dissertations

Feature selection is a data processing approach that has been successfully and effectively used in developing machine learning algorithms for various applications. It has been proven to effectively reduce the dimensionality of the data and increase the accuracy and interpretability of machine learning algorithms. Conventional feature selection algorithms assume that there is an optimal global subset of features for the whole sample space. Thus, only one global subset of relevant features is learned. An alternative approach is based on the concept of Local Feature Selection (LFS), where each training sample can have its own subset of relevant features. Multiple Instance …

"If Fear Wasn't Enough?!": African American Perceptions Of Policing After Breonna Taylor's Unprovoked Death., Moriah Antoinette Bellamy

Electronic Theses and Dissertations

This study investigates how African Americans perceive the racialization process in the criminal justice system following the death of Breonna Taylor. Focusing primarily on police-community relations in Louisville, KY, I find the Breonna Taylor case amplifies preconceived perceptions of race between civilian and non-civilian groups. To test the hypothesis that racialization in the criminal justice system has caused damaging effects on relations between African Americans and police, two virtual focus groups were designed to discuss participants’ experiences with law enforcement. My findings suggest that the racialization process in the criminal justice system negatively skewed African American civilians’ attitudes towards law …

Collaborative Human-Machine Interfaces For Mobile Manipulators., Shamsudeen Olawale Abubakar

Electronic Theses and Dissertations

The use of mobile manipulators in service industries as both agents in physical Human Robot Interaction (pHRI) and for social interactions has been on the increase in recent times due to necessities like compensating for workforce shortages and enabling safer and more efficient operations amongst other reasons. Collaborative robots, or co-bots, are robots that are developed for use with human interaction through direct contact or close proximity in a shared space with the human users. The work presented in this dissertation focuses on the design, implementation and analysis of components for the next-generation collaborative human machine interfaces (CHMI) needed for …

Visualizing Anhydrobiosis: Liquid-Liquid Phase Separation, Membraneless Organelles, And Cellular Reorganization., Clinton J. Belott

Electronic Theses and Dissertations

Water is an integral and necessary component of life. It is then, exceedingly remarkable that some species are capable of surviving virtually complete water loss for extended periods of time. Several decades of intense research into anhydrobiosis, or life without water, have given significant insights into the molecular mechanisms governing this phenomenon. Anhydrobiosis-related intrinsically disordered (ARID) proteins have been demonstrated to be critically important for desiccation tolerance in many anhydrobiotic species and exhibit a considerably wide range of protective properties that include membrane stabilization, reinforcing bioglass formation, and protein stabilization. This dissertation begins with cellular dielectrophoresis suggesting that two ARID …

Sustainable Urban Groundwater Governance In Faisalabad, Pakistan: Challenges And Possibilities., Shahbaz Altaf

Electronic Theses and Dissertations

Groundwater use is high in developing countries, especially in places where municipal water authorities struggle to meet the water demand of their residents. To analyze the interactions between groundwater and piped water in the Global South context, Faisalabad, Pakistan was taken as the case study area. Using the Institutional Analysis and Development framework and Elinor Ostrom’s design principles as analysis tools, formal and informal institutions governing the piped water and groundwater, including their congruence with the social and ecological factors, were explored. The results showed that scarcity of piped water pushed people towards groundwater and the absence of informal and …

Digital Design And Thermomechanical Process Simulation For 3d Printing With Abs And Soyhull Fibers Reinforced Abs Composites., Saleh Khanjar

Electronic Theses and Dissertations

Recent demonstrations with fused filament fabrication (FFF) 3D printing have shown to produce prototypes as well as production components. Additionally, due to the FFF process platforms being low-cost and readily available there has been a high-demand to produce on-demand parts for various applications in automotive, in-space manufacturing and electronic industries. However, current limitations such as limited availability of advanced composites materials, and guidelines for design-for-manufacturing make the process prone to trial-and-error experiments both at the materials development, product design and manufacturing stage. In this work, new thermomechanical process simulations platform, Digimat-AM has been evaluated to address and demonstrate digital design …

Lung Nodules Identification In Ct Scans Using Multiple Instance Learning., Wiem Safta

Electronic Theses and Dissertations

Computer Aided Diagnosis (CAD) systems for lung nodules diagnosis aim to classify nodules into benign or malignant based on images obtained from diverse imaging modalities such as Computer Tomography (CT). Automated CAD systems are important in medical domain applications as they assist radiologists in the time-consuming and labor-intensive diagnosis process. However, most available methods require a large collection of nodules that are segmented and annotated by radiologists. This process is labor-intensive and hard to scale to very large datasets. More recently, some CAD systems that are based on deep learning have emerged. These algorithms do not require the nodules to …

Additive Manufacturing Using Robotic Manipulators, Fdm, And Aerosol Jet Printers., Alexander Curry

Electronic Theses and Dissertations

Additive manufacturing has created countless new opportunities for fabrication of devices in the past few years. Advances in additive manufacturing continue to change the way that many devices are fabricated by simplifying processes and often lowering cost. Fused deposition modeling (FDM) is the most common form of 3D printing. It is a well-developed process that can print various plastic materials into three-dimensional structures. This technology is used in a lot of industries for rapid prototyping and sometimes small batch manufacturing. It is very inexpensive, and a prototype can be created in a few hours, rather than days. This is useful …

Atomistic Investigation Of Phase Stability And Sodium Ion Conduction In Sulfide Electrolytes., Sabina Zakhidovna Chertmanova

Electronic Theses and Dissertations

In this thesis, we employ a combination of density functional theory (DFT) calculations, and ab initio molecular dynamics (AIMD) simulations to identify the effect of chemical doping on (a) thermodynamic phase stability, and (b) Na-ion conduction in Na₃SbS₄ (NSS) solid-state electrolytes. We found that (a) Se doped electrolytes, namely, Na₃SbS_exS_4-x undergo a tetragonal-to-cubic structural phase transition at x > 3 (Se-rich), and (b) the size, valence, and electronegativity of chemical dopants that substitute Na in Na₃SbS₄ have a cumulative profound impact on Na-ion conductivity. Specifically, substituting Na with higher valence …

An Investigation Into Energy-Material Properties Interaction In Additive Manufacturing Of Polymers., Pu Han

Electronic Theses and Dissertations

Additive manufacturing (AM), known as three-dimensional (3D) printing, is a fabrication process to build 3D objects layer by layer based on computer aided design (CAD) model or digital 3D model. Fused filament fabrication (FFF) has become a preferred method for additive manufacturing due to its cost-effectiveness and flexibility. However, the parts built using FFF process suffer from lower mechanical strength compared to that fabricated using traditional method and rough surface finish. With this motivation, this dissertation aims to develop and implement a novel in-process laser assisted technique on FFF to heal the microstructure of FFF built objects by enhancing reptation …

Hybrid Structural Health Monitoring Using Data-Driven Modal Analysis And Model-Based Bayesian Inference., Jice Zeng

Electronic Theses and Dissertations

Civil infrastructures that are valuable assets for the public and owners must be adequately and periodically maintained to guarantee safety, continuous service, and avoid economic losses. Vibration-based structural health monitoring (VBSHM) has been a significant tool to assess the structural performance of civil infrastructures over the last decades. Challenges in VBSHM exist in two aspects: operational modal analysis (OMA) and Finite element model updating (FEMU). The former aims to extract natural frequency, damping ratio, and mode shapes using vibrational data under normal operation; the latter focuses on minimizing the discrepancies between measurements and model prediction. The main impediments to real-world …

Coal Fly Ash Beneficiation For Reuse And Removal Of Boron, Cadmium, Chromium, Copper, And Selenium In Wastewater Treatment., Joseph E. Cahill

Electronic Theses and Dissertations

New regulations on coal-fired power plants make previously used wastewater treatment methods aimed to remove heavy metals obsolete. Therefore, there has been increased interest and investment into new technologies to treat coal-fired power plants effluent in the past few years. Traditionally, heavy metal removal technologies have been broken into three categories: physical, chemical or biological. However, with new regulations, each category by itself does not offer an ideal solution to removing acceptable concentrations of heavy metals found in the effluents at the coal-fired power plants. Here we report a novel proof-of-concept utilizing adsorption through ion-exchange/co-precipitation - chemical and physical - …

Solvent Engineering Of Molybdenum Disulfide Electrocatalyst For Hydrogen Evolution., Robert Carl Spalding

Electronic Theses and Dissertations

Energy is at an exponentially growing demand, and to keep up with these demands new technologies for renewable energy have received increased attention. Hydrogen plays a vital role in water electrolysis and fuel cells, as the hydrogen evolution reaction (HER) is the main step water splitting process. Most of the current electrocatalysts for HER are dominated by platinum and other precious metals due to their low over-potential and small Tafel slope, however, they are extremely costly. For this reason, cost-effective non-precious metal catalysts must be developed. Transition metal dichalcogenides, such as molybdenum disulfide (MoS2), are abundant and have recently shown …

Update Of Multicellular Data Standard To Match Physicell "Compact" Output., Reid A Honeycutt

Electronic Theses and Dissertations

In the field of multicellular biology, it is currently very difficult for researchers to share digital data, due to a lack of standards for said data. Each laboratory will collect data from a particular project, which will describe only the features relevant to their research, and then present that data using written descriptions, charts, graphs, and images. This makes it difficult for the data produced by these studies be leveraged in other research efforts by scientists studying similar phenomena. An open-source, universal standard that attempts to meet this need is the MultiCellular Data Standard (MultiCellDS). MultiCellDS is described as a …

Analyzing The Non-Isothermal Multiphasic Flow In Porous Media Through Strongly Coupled Thermo-Hydro-Mechanical Modeling., Mohammadreza Mir Tamizdoust

Electronic Theses and Dissertations

Underground geo-structures and climate change can trigger coupled heat, moisture, and vapor flow in shallow and deep subsurface which is frequently referred to as non-isothermal multiphase flow. The coupled multiphasic flow in soil may induce volumetric shrinkage or expansion deformation depending on the thermo-hydraulic loading condition. In saturated porous media, temperature gradient and heat transfer may affect pore fluid pressure and/or pore fluid flow depending on thermal, mechanical, and hydraulic properties of the media and the saturating fluid. In vadose zones, the prediction of coupled nonisothermal multiphase flow in porous media has been the subject of many theoretical and experimental …

Addressing The Psychosocial State Of High-Risk Individuals Undergoing Hereditary Cancer Screening By Advanced Practice Registered Nurses (Aprns) In The Community Oncology Setting, Aquilina Kerubo Thompson

Electronic Theses and Dissertations

Abstract

Neoteric advances in genetics make it possible to define genetic risk in cancer, and there should be methods in place to provide comprehensive genomic care with oncology advanced practice registered nurses bridging this gap. The current scope of nursing practice stipulates genetic and genomic literacy; however, there remains a deficit among advanced practice registered nurses in identifying and addressing psychosocial distress during the genetic cancer risk assessment process. Oncology advanced practice registered nurses must be equipped with the knowledge that the genetic cancer risk assessment also involves protecting patients from the psychosocial repercussions of carrying a hereditary cancer gene …

Reducing The Potential For Physical Harm In Student Nurses Caring For Clients Who Are Under The Influence, Hunter William Halford

Electronic Theses and Dissertations

This DNP project was conducted to identify gaps in knowledge and adequate preparation of nursing students in safely caring for a client who is behaving violently and is under the influence of illicit drugs. Student nurses are trained using a generalist approach, meaning they are taught the essentials of a variety of topics. It is not until these students enter the workforce that they are trained specifically for a certain position. Currently, the curriculum does not address specific measures to maintain client and personal safety. It is an almost unavoidable fact that a nurse will encounter a violent client or …

Rural School District Strategies To Increase College, Career, And Military Readiness, Amelia J. Reeves

Electronic Theses and Dissertations

Preparing students for life after high school is a challenge faced by all K-12 educators. In small, rural school districts, school leaders encounter unique barriers and limitations due to the limited capacity of school counselors, geographic isolation, lack of resources, and other factors. The purpose of this qualitative, multiple case study was to explore the district-wide strategies utilized by rural school districts in West Central Texas to increase the career, college and military readiness (CCMR) of all students. Five cases were identified that met the criteria, which included being a rural district defined by TEA, a school administrator responsible for …

The Lived Experiences Of Filipino Teachers Teaching In Texas: A Transcendental Phenomenological Study, Jeffrey Chua

Electronic Theses and Dissertations

Among the estimated 100,000 Overseas Filipino Workers (OFW) working in the United States, a small group of Filipino teachers may have lasting impacts on one of the most important pillars of the nation: its public schools. Thus, it is important to understand the lived experiences of Filipino teachers teaching in Texas. This research aimed to contribute to existing literature that explores the lived experiences and the acculturation process of Filipino teachers. Utilizing a transcendental phenomenological approach, seven such teachers were selected through snowball sampling and were interviewed. The findings of the study showed their shared experiences revolved around four themes: …

Improving Sexually Transmitted Infection Knowledge In Community College Students: A Path To Prevention, Rebecca F. Halford

Electronic Theses and Dissertations

This DNP project was conducted to identify gaps in knowledge focusing on sexually transmitted infections within Texas and Region one. The research study gathered data from first-year nursing students who have chosen to participate in a sexually transmitted infection-focused educational module. Participants were first-year nursing students and understood the research study was strictly voluntary with no forms of compensation. Currently, the curriculum in the nursing program at which the study took place does not focus on sexually transmitted infections and is directed to speak minimally on the subject. This is a contributing factor to why the rise in sexually transmitted …

Reducing Parental Stress In Neonatal And Pediatric Intensive Care Units, Nancy M. Abbene

Electronic Theses and Dissertations

Abstract

The neonatal intensive care unit (NICU) and pediatric intensive care unit (PICU) are highly operational and highly active environments. Health care workers must react quickly to care for patients and provide life-saving measures fundamental to favorable patient outcomes. Caregivers of this critical patient population are often overlooked as the healthcare team prioritizes patient’s needs. In addition, medical equipment, machines, and monitors have multiple safety alarms sounding frequently and contributing to high levels of parental stress upon their child’s admission to the NICU and PICU. Lack of giving adequate prominence to the value of caregiver support services in the hospital …

An Evaluation Of An Integrated Multidisciplinary Early Identification And Triage Of College Students At Risk For Anxiety And Depression, Sarah J. Templeton

Electronic Theses and Dissertations

College students across the U.S. are experiencing an increasing prevalence of mental health concerns, such as anxiety and depression. Suicide is currently the second most common cause of death among U.S. college students. At the project site, the university health services report that mental health issues significantly impact the students’ academic progress, contributing to poor performance, inability to complete assignments, and sometimes forces attrition. Campus providers traditionally respond when students approach, often at the point of crisis or exacerbation. This Doctor of Nursing Practice (DNP) project evaluated the impact of a pilot program using an interdisciplinary approach to universal proactive …

Interdependence With Our Most Forgetful Elders: Alzheimer's In The Anthropocene, Christine Heller

Electronic Theses and Dissertations

This dissertation uses autoethnography and critical psychological and philosophical theories to explore what people with Alzheimer’s disease teach us about being, forgetting, and dying in the Anthropocene. The author collected personal memory data from her lived experience of being with her mother while she had Alzheimer’s disease, and organized these memories into a series of vignettes. Each vignette was analyzed with critical psychological and philosophical theories to illuminate intersubjective themes of denial, things, ancestors, place, dying, and time. These themes connected the personal to the epochal and articulated the wisdom that our most forgetful elders can share in the Anthropocene, …

Towards A "Universal Chemical Biology Toolbox" For Tackling Human Diseases, Christopher Swank

Electronic Theses and Dissertations

A lack of new drug targets and drug mechanisms, coupled with drug-pipeline attrition, represent significant problems in oncology drug discovery. Towards addressing this challenge, “fully-functionalized small-molecule probes” (FFSMPs) have been established, which are compounds that can be immediately used as “bait” to capture their protein targets under the same assay conditions used for oncology-based phenotypic screening. Specifically, each FFSMP library member contains one or more structural-diversity elements to promote interactions of the probe with different protein targets in living cells, an electrophile or photoreactive functional group for covalent attachment of the probe to interacting proteins via affinity or photoaffinity labeling, …