Digital Commons Network^™

The Effect Of Heat Treatment On Mechanical Properties Of Additively Manufactured 17-4 Ph Stainless Steel, Nicholas Aaron Hopkins

Theses and Dissertations

Additive manufacturing (AM) is used to create geometries otherwise impossible to machine. Topology optimization, microstructural texture control, and the use of lattices could be created through AM to increase performance of systems. Currently research focuses on solution aging of printed 17-4 PH, while other heat treatments are not as heavily studied. This study identifies different heat treatments applied to additively manufactured 17-4 precipitation hardened (PH) and the effects on mechanical properties. This study used quasi-static tension, quasi-static compression, and Charpy V-notch testing to analyze the effects of heat treatment as well as the effectiveness of additive manufacturing compared to traditional …

Essays On The Performance Of Option Trading Strategies, Zhuo Li

Theses and Dissertations

This dissertation consists of two parts. In the first chapter, we examine the relative performance of four options-based investment strategies versus a buy-and-hold strategy in the underlying stock. Specifically, using ten stocks widely held in 401(k) plans, we examine monthly returns from strategies that include a long stock position as one component. These strategies are long stock, covered call, protective put, collar, and covered combination. Ignoring early exercise for simplicity, we find that the covered combination and covered call strategies generally outperform the long stock strategy, which in turn generally outperforms the collar and protective put strategies regardless of the …

Experiments To Mitigate Flow Recirculation In A Closed Anechoic Chamber Using Mesh Screens As Turbulence Suppressors, Tori Kay Wolverton

Theses and Dissertations

The desire to gather acoustic data of a propeller in simulated hover without environmental effects is met with the challenge of recirculating flow in a closed anechoic chamber. Flow recirculation in an anechoic chamber is not ideal because the effects of it being ingested by the rotor cause unsteady loadings on the propeller. This unsteady loading causes vortex noise from the turbulence introduced by the recirculation of the flow. The aim is to study the acoustic signature of a propeller separate from external factors and engine noise. Two different propellers with three different screen combinations were tested in a closed …

Beyond The Pta: Mothering Work And Women's Education Activism In The Deep South, Emily L. Tingle

Theses and Dissertations

It has long been established that women play unique roles within schools, volunteerism, and school-based community work (Griffith and Smith 2005; Calarco 2020; Lewis and Diamond 2015; Posey-Maddox 2014). Additionally, research suggests that the work done surrounding the institution of education primarily falls on mothers (Griffith and Smith 2005; Haley-Lock and Posey-Maddox 2016; Lareau 2000; Lareau 2011). However, little research has been done that explores how gender dynamics play out in education activism that lies outside of schools. This study seeks to understand how women view gendered expectations of mothering work in regard to education and if/how they perceive that …

Using Stimulus Equivalence To Improve Portion Size Estimates In Emerging Adults With Developmental Disabilities, Laura M. Quintero

Theses and Dissertations

The purpose of this current study was to evaluate the use of a stimulus equivalence paradigm to teach emerging adults with developmental disabilities to accurately estimate portion sizes. This study also aimed to integrate nutritionally recommended foods to incorporate a socially significant component to promote health related behaviors. Three emerging adults with various developmental disabilities participated in this study. A pre/post-test embedded in a multiple baseline design across food was used to demonstrate experimental control. Results of this study indicated that all participants exhibited accurate portion size estimations following stimulus equivalence direct training trials and test of untrained relations. When …

Ferrous Alloy Manufacturing For The Martian Surface Through In-Situ Resource Utilization With Ionic Liquids Harvested Iron And Bosch Process Carbon, Blake C. Stewart

Theses and Dissertations

As research continues for the habitation of the Lunar and Martian surfaces, the need for materials for construction of structural parts, mechanical components, and tools remains as a major milestone. The use of in-situ resource utilization (ISRU) techniques is critical due to the financial, physical, and logistical burdens of sending supplies beyond low-Earth orbit. The Bosch process is currently in development as a life support system at the National Aeronautics and Space Administration’s (NASA) Marshall Space Flight Center (MSFC) to regenerate oxygen (O2) from metabolic carbon dioxide (CO2) with the byproduct of elemental carbon (C). The Bosch process presents a …

Assessing The Usefulness Of The Livingroom Learning Gardens At Galloway Elementary School, Partnership Middle School, And Leland Park Middle School For Teaching, Benjamin Little Gunter

Theses and Dissertations

As more schools incorporate learning gardens into their campuses to help educate school children on nutrition (Parmer and Stuempler, 2009), connect students to nature (Bucher, 2017), and grow healthy food; there is a need to better understand how the physical design and components of the garden facilitate the use and programming of the gardens for teaching. There is little research on how the physical characteristics of a garden influence those benefits and challenges. This study seeks to assess the usefulness of an intentionally designed garden typology that has been implemented at three different school sites. By documenting the differences between …

Assessing The Functional Impacts Of Acquired Syphilis In Industrial England, Cassandra Marie Seda Degaglia

Theses and Dissertations

This work identifies and describes pathological skeletal changes associated with and attributable to acquired syphilis and which potentially caused functional impairment within eleven skeletal individuals recovered from five industrial-era London cemeteries. In eight (72.73%), functional impairment was likely or very likely, based on type and distribution of lesions across their skeleton. These impairments likely impacted the individuals’ ability to engage in various forms of physical activity, potentially limiting their economic potential. These results expand our still highly limited understanding of syphilis’s functional impacts within past populations, especially within industrial-era societies, querying longstanding characterizations of tertiary gummatous involvement as benign, while …

Perceived Location Of Virtual Content Measurement Method In Optical See Through Augmented Reality, Farzana Alam Khan

Theses and Dissertations

An important research question for optical see through AR is, “how accurately and precisely can a virtual object’s perceived location be measured in three dimensional space?” Previously, a method was developed for measuring the perceived 3D location of virtual objects using Microsoft HoloLens1 display. This study found an unexplained rightward perceptual bias on horizontal plane; most participants were right eye dominant, and consistent with the hypothesis that perceived location is biased in eye dominance direction. In this thesis, a replication study is reported, which includes binocular and monocular viewing conditions, recruits an equal number of left and right eye dominant …

Three Case Studies Of Using Hybrid Model Machine Learning Techniques In Educational Data Mining To Improve The Classification Accuracies, Sujan Poudyal

Theses and Dissertations

A multitude of data is being produced from the increase in instructional technology, e-learning resources, and online courses. This data could be used by educators to analyze and extract useful information which could be beneficial to both instructors and students. Educational Data Mining (EDM) extracts hidden information from data contained within the educational domain. In data mining, hybrid method is the combination of various machine learning techniques. Through this dissertation, the novel use of machine learning hybrid techniques was explored in EDM using three educational case studies. First, in consideration for the importance of students’ attention, on and off-task data …

Utilizing Unmanned Aerial Systems To Sample Insects In Soybean, Marvin Merkl

Theses and Dissertations

To overcome some limitations of manual insect sampling in soybeans, an unmanned aerial vehicle (UAV) sampling platform was developed that could collect insects in a sweep net attached to the bottom of a UAV. Before this UAV sampling platform can be used to make management decisions, correlations with manual sweep net and/or drop cloth sampling methods are needed. This will allow action thresholds for the various pests to be calculated for the UAV sampling platform. To make the correlations, 87 soybean fields were sampled during 2020 and 2021 with each of 4 sampling methods, a UAV travelling 50-m, the same …

A Biomechanical Approach To Prevent Falls In Ergonomic Settings, Sachini Kodithuwakku Arachchige

Theses and Dissertations

Introduction: Fall-related injuries are exceptionally prevalent in occupational settings. While endangering the workers’ health, falls cause poor productivity and increased economic burden in the workplace. Hence, identifying these threats and training workers to achieve proper postural control is crucial. Purpose: Study 1: To investigate the ankle joint kinematics in unexpected and expected trip responses during single-tasking (ST), dual-tasking (DT), and triple-tasking (TT), before and after a physically fatiguing exercise. Study 2: To investigate the impact of virtual heights, DT, and training on static postural stability and cognitive processing. Methods: Study 1: Twenty collegiate volunteers (10 males and females, one left …

Gpgpu Microbenchmarking For Irregular Application Optimization, Dalton R. Winans-Pruitt

Theses and Dissertations

Irregular applications, such as unstructured mesh operations, do not easily map onto the typical GPU programming paradigms endorsed by GPU manufacturers, which mostly focus on maximizing concurrency for latency hiding. In this work, we show how alternative techniques focused on latency amortization can be used to control overall latency while requiring less concurrency. We used a custom-built microbenchmarking framework to test several GPU kernels and show how the GPU behaves under relevant workloads. We demonstrate that coalescing is not required for efficacious performance; an uncoalesced access pattern can achieve high bandwidth - even over 80% of the theoretical global memory …

Assessment Of Postural, Locomotor, And Physical Fitness Status In Individuals With Intellectual And Developmental Disabilities, Alana J. Turner

Theses and Dissertations

Introduction: Postural control and locomotion deficits can be observed during the early years of childhood development and throughout life. For those with disabilities, these deficits can advance past the development years and into adolescence and adulthood while affecting the quality of life and daily activity. Finding interactive rehabilitative activities to delay or limit these deficits is essential for people with disabilities to improve their quality of life, inclusion, and overall movement. Adapted physical activity/sports like badminton and virtual reality could promote improvements in postural and locomotor status for young adults with intellectual and developmental disabilities like cerebral palsy (CP), intellectual …

Examining The Barriers To Building Multicultural Competence Of School Psychology Graduate Students, Jasmine C. Gray

Theses and Dissertations

Historically, school aged students from diverse backgrounds have experienced detrimental effects as a result of school psychologists who fail to consider cultural differences when providing services. The demographics of students in K- 12 schools have increasingly become more diverse which only exacerbates the need for multiculturally competent school psychologists. Research has identified graduate programs as an area to intervene and ensure future school psychologists are receiving training necessary for developing multicultural competence. Within the literature, graduate student attitude towards multiculturalism and program climate have been identified as barriers to developing multicultural competence in graduate students. Therefore, the purpose of the …

Utilization Of A Boosted Regression Tree Framework For Prediction Of Dissolved Phosphorus Concentrations Throughout The High Plains Aquifer Region, Jeffrey M. Temple

Theses and Dissertations

Groundwater-derived phosphorus has often been dismissed as a significant contributor towards surface water eutrophication, however, this dismissal is unwarranted, making the quantification of phosphorus concentrations in groundwater systems immensely important. Machine learning models have been employed to quantify the concentrations of various contaminants in groundwater, but to our best knowledge have never been used for the quantification of groundwater phosphorus. The goal of this research was to use a boosted regression tree framework to produce the first believed machine learning model of phosphorus variability in groundwater, with the High Plains aquifer serving as the study area. Results display a boosted …

Inosine 5’- Monophosphate Derived Umami Flavor Intensity Of Beef Determination By Electrochemistry And Chromatography, Kezia Virellia To

Theses and Dissertations

The umami sensation contributes to beef flavor and acceptability. Inosine 5’- monophosphate (IMP) was the most abundant nucleotide in meat known to impart umami taste which thus far had been overlooked in meat flavor studies. The objectives of this study were to determine the umami taste threshold of inosine 5'-monophosphate (IMP), the effects of spiking IMP on the sensory descriptive attributes of various USDA graded beef strip steaks, and to differentiate beef by IMP content using electrochemistry. USDA Prime, Choice, and Select steaks were spiked with 0.3 and 0.6 mM IMP and analyzed chemically and organoleptically. Liquid chromatography-mass spectrometry and …

Success And Confidence In, Or Inclusive Of, Undergraduate Chemistry Students Surrounding A Collaborative Learning Intervention, Encouragement Of Metacognition, And A Multifaceted Scholarship Support Program, Maggie Erin Leake

Theses and Dissertations

Student success in chemistry has been linked to a wide range of factors. Some of these factors are familiar, easily quantified measures; colleges typically rely on factors like high school GPA and measures of aptitude to make admission decisions or set course prerequisites. Success in chemistry courses can be linked to these measures, and math aptitude scores in particular are often used as prerequisites for introductory chemistry courses. However, success in chemistry can also be affected by factors like motivation, peer interactions, sense of belonging, and metacognitive skill. Additionally, outcomes in chemistry and other STEM courses like math and physics …

Development And Characterization Of A Peanut-Shell Based Activated Carbon And The Outcomes Of A Hands-On Approach To Chemical Education, Danielle Pitre

Theses and Dissertations

Heavy metals are a recognized toxic environmental contaminant, even at very low concentrations. There have been well-known events in the last decade within the US of high amounts of lead in the drinking water supplies of cities, leading to detrimental effects within its population. Ways have been found to remove this metal, and others, from water with expensive adsorbents. The aim of the first part of this research was to create an inexpensive adsorbent from a waste material and modify it in such a way that it would be adept at removing heavy metals from water.

In Chapter I, we …

The Relationship Between Leadership Preference Of County Level Personnel Within University Of Missouri Extension And Their Level Of Employee Engagement, Jason C. Morris

Theses and Dissertations

The purpose of this study was to describe the perceived leadership style of the University of Missouri Extension Service county staff and their level of engagement and study the relationship between variables. Administrators with University of Missouri Extension Service can utilize this information to better serve Extension Staff and ultimately people throughout the state of Missouri.

The Vannsimpco Leadership Survey was used to measure the perceived leadership style of county level staff. The Utrecht Work Engagement Scale (UWES) was used to measure work engagement on three constructs: vigor, absorption, and dedication engagement. Demographic characterizes of county level staff was also …

An Investigation Of Geostationary Satellite Imagery To Compare Developing And Non-Developing African Easterly Waves, Jenna Bartlett

Theses and Dissertations

African easterly waves (AEWs) are known precursors to tropical cyclone (TC) formation, although it is not always clear which AEWs will develop and which AEWs will not. To investigate AEW evolution, this study examines novel observations from the geostationary Advanced Baseline Imager (ABI) during July-September 2019. Case studies are conducted for two AEWs: one that became Hurricane Dorian, the strongest and most devastating hurricane of the 2019 Atlantic hurricane season, and a long-lived September AEW that did not become a TC. Lower-level moisture and flow, and the strength and spatial distribution of convective activity, differed between these two waves. By …

Polyaniline-Derivatives Based On Poly (Heterocyclic Diphenylamine) With Improved Electrochemical Stability And Processability, Mohammed Noifa Almtiri

Theses and Dissertations

Today, smart innovation has become an essential part of human life; thus, contemporary technologies are always looking for intelligent, responsive, and efficient materials to satisfy these demands. Consequently, synthetic "metals" or, more precisely, intrinsically conducting polymers (CPs) have begun to find a place as valuable and practical materials for a new generation of devices. Amongst all intrinsic conducting polymers, polyaniline (PANI) has attracted significant attention due to its outstanding air and moisture stability, simple preparation technique, and high electrical conductivity (chapter I).

Chapter II represents the synthesis of a new PANI derivative that contains a phenoxazine unit co-polymerized with p-phenylenediamine …

U.S. Financial Literacy: Does Urban-Rural Residency Matter?, Mckenzie Leanne Carvalho

Theses and Dissertations

Financial illiteracy broadly affects people’s financial and economic well-being. The purpose of this thesis is to identify how the magnitudes of financial literacy determinants change under different residency settings. A county-level calculation of financial literacy is created, and logit and negative binomial regressions are employed to compare the relationship between demographic variables and financial literacy in metro/non-metro and urban/rural counties. Data on individual’s financial knowledge and personal characteristics is obtained from the FINRA National Financial Capability Study. Urban and rural residency is determined using USDA ERS Rural-Urban Continuum Codes and the Index of Relative Rurality. These results provide an improved …

Assessing Readiness For Implementation Of Prognostics And Health Management In Small And Medium Enterprises, Sara C. Fuller

Theses and Dissertations

Prognostics and Health Management (PHM) refers to using robust sensing, monitoring, and control to detect, assess, and track system health degradation and failure modes, allowing for enhanced management and operational decisions. The need for PHM within a manufacturing facility has increased due to a variety of reasons, such as the increasing complexity of manufacturing equipment.

A lack of readiness for digital implementations is linked to failure. The literature highlights certain barriers and enablers that can signal whether a technology implementation will be successful, such as management and maintenance employees’ desire to change the existing process, an understanding and willingness to …

Assessing The Flood Tolerance, Physiological Mechanism, And Nutrient Mitigation Potential Of Short Rotation Woody Crops Planted On Seasonally Flooded Marginal Land Of The Lower Mississippi Alluvial Valley, Thu Ya Kyaw

Theses and Dissertations

In 2019, the Mississippi River watershed had a record-long flooding, which was comparable with the 1927 Great Mississippi River Flood. This study leveraged this flooded condition to assess the flood tolerance of eastern cottonwood (Populus deltoides) and black willow (Salix nigra) planted as short rotation woody crops (SRWCs) on seasonally flooded marginal land of the Lower Mississippi Alluvial Valley (LMAV) in 2018. The survival/mortality prediction models developed by using hydrologic and environmental variables suggested that only high flood depth affected the survival of black willow. However, eastern cottonwood was threatened by flood depth, flood duration, and …

Sustainable Sidedress Nitrogen Applications For Early Corn And Cotton Crops Using Small Unmanned Aerial Systems, James Nolan Parker

Theses and Dissertations

Nitrogen run-off from agriculture have been linked to human health problems on a global level. Large-scale conventional producers struggle to redefine themselves as sustainable because reducing nitrogen (N) inputs without justification or validation may lead to severe profit losses. Small unmanned aerial systems (sUAS) sensing may allow for decreased N runoff. Failure to address this problem will exacerbate already excessive N runoff into the Mississippi River and beyond. The purpose of this study was to reduce fertilizer N input using sUAS technology to assess crop canopy needs. In 2020 and 2021, variable rate nitrogen (VRN) side-dress N application maps were …

Determining The Effects Of Elevated Carbon Dioxide On Soil Acidification, Cation Depletion, And Soil Inorganic Carbon And Mapping Soil Carbons Using Artificial Intelligence, Jannatul Ferdush

Theses and Dissertations

Soil carbon is the largest sink and source of the global carbon cycle and is disturbed by several natural, anthropogenic, and environmental factors. The global increase of atmospheric CO₂ affects soil carbon cycling through varied biogeochemical processes. The first chapter is a compilation of current information on potential factors triggering soil acidification and weathering mechanisms under elevated CO₂ and their consequences on soil inorganic carbon (SIC) pool and quality. Soil water content and precipitation were critical factors influencing elevated CO₂ effects on the SIC pool. The second chapter examines a detailed column experiment in which six soils …

Improvement Value Of Forest Resources By Use Of Cottonseed Protein Meal As A Bio-Based Wood Adhesive For Hardwood Plywood Products, Edward David Entsminger

Theses and Dissertations

Literature shows that production of cottonseed adhesives is feasible to develop an environmentally friendly and competitive bio-based wood adhesive. Defatted cottonseed and water-washed cottonseed meals were prepared from glandless cottonseed and were used in adhesive formulations to produce three-ply yellow poplar (Liriodendron tulipifera) plywood panels as the first objective. These two cottonseed meals were compared with the properties of plywood panels made with an adhesive formulated from a commercial soybean meal, as a control. Adhesive resins were prepared from each protein meal with sodium metabisulfite (Na2S2O5) and one of two polyamido-amine-epichlorohydrin (PAE) wet strength agents, and the plywood panels were …

How And With Whom You Spend Your Time Matters: An Examination Of Familial Relationships, Leisure Activities, And Dementia Development, Erika Cooksey Mcdaniel

Theses and Dissertations

Dementia is an interminable disorder characterized by a decrease in cognitive functioning behavioral and emotional changes, and an overall diminishment in quality of life that usually affects the older population. In the coming decades, scientists estimate that the number of sufferers will reach over 100 million worldwide. Though there is currently no cure for any form of dementia, the theory of cognitive reserve posits certain lifestyle characteristics (i.e., educational attainment, SES, and/or career path) can mitigate the risk of dementia by improving cognitive resilience over an individual’s lifetime. The current study sought to discover what, if any, effects familial relationships, …

Short-Term Electricity Price Point And Probabilistic Forecasts, Chenxu Zhang

Theses and Dissertations

Accurate short-term electricity price forecasts are essential to all electricity market participants. Generation companies adopt price forecasts to hedge generation shortage risks; load serving entities use price forecasts to purchase energy with low cost; and trading companies utilize price forecasts to arbitrage between markets.

Currently, researches on point forecast mainly focus on exploring periodic patterns of electricity price in time domain. However, frequency domain enables us to identify more information within price data to facilitate forecast. Besides, price spike forecast has not been fully studied in the existing works. Therefore, we propose a short-term electricity price forecast framework that analyzes …