Digital Commons Network^™

Membrane Fabrication And Functionalization For Improved Removal Of Monovalent Ions From Water Using Electrodialysis, Matthew P. Sheorn

Theses and Dissertations

Electrodialysis is a membrane separation process that uses an electrical potential to drive the separation. The performance of these systems is largely based on the performance of their ion exchange membranes (IEMs). This research focused on enhancing the performance of IEMs for electrodialysis through surface modification techniques involving chitosan bonded to the surface of commercially available cation exchange membranes (CEMs). The surface functionalization techniques resulted in membranes with improved electrodialysis performance. This research also explored the processing framework to produce functionalized sulfonated PEEK (sPEEK) nanofibers for future consideration as cation exchange membranes.

Chitin was deacetylated to form the functionalized biopolymer …

Visual Acquisition And Detection Of Manned Fixed-Wing Aircraft And Rotorcraft: An Analysis Of Pilots' Perception And Performance, Rania Bassou

Theses and Dissertations

In recent years, the rapid advancement of Unmanned Aircraft Systems (UAS) has led to an increasingly complex National Airspace System (NAS), necessitating a comprehensive understanding of factors that impact pilot visual acquisition and detection of other aircraft (including manned fixed-wing, rotorcraft, and UAS). The objective of this study is to investigate factors that affect pilot performance in visually acquiring and detecting other manned-fixed wing aircraft and manned rotorcraft using a multi-method approach, incorporating qualitative and quantitative data analysis. A diverse sample of pilots with varying flight experience participated in the study. Participants were exposed to a series of flight test …

Effects Of Electrical Stimulation On Water-Soluble Flavor Compounds In Beef Semimembranosus Muscle, Chelsie Beebe

Theses and Dissertations

This study examined the effects of electrical stimulation on water-soluble flavor compounds in beef semimembranosus muscle, collected immediately after exsanguination (PRE), immediately after stimulation (POST), and 24 h postmortem (H24) from both stimulated (ES) and non-stimulated (CON) carcasses. Short-chained peptides were greater in ES at H24 (P = 0.007). Glutamic acid concentration was above its taste threshold (0.044 mmol/kg) and was less in ES at PRE and POST by 0.030 mmol/kg (P ≤ 0.028) but was similar in both ES and CON by H24 (P = 0.142). Lysine, a Strecker amino acid, was greater in ES at H24 by 0.138 …

The Cost Of Voting Categorized: A Comprehensive Review, Landon Brady

Theses and Dissertations

The primary purpose of this paper is to analyze the research field of cost of voting and review the relevant literature on voter participation. After reviewing the literature, a development of a theoretical framework to categorize multiple variables associated with the cost of voting will be completed. The goal is to create clear, concise, and simple categories that define the cost of voting. This should add conceptual clarity to the field by linking variables into a common foundation. The research also connects the sociological and psychological category of intrapersonal to concepts of social group needs, sense of achieving a greater …

Examining The Impact That A Modified School Calendar Had On Teacher Attendance In A Rural Mississippi School District, James W. Carlisle Jr.

Theses and Dissertations

Educational leaders have long recognized the certified classroom teacher as the most important factor in student performance and success. In his research article Teachers Matter: Understanding Teachers’ Impact on Student Achievement for the Rand Corporation, Opper (2019) stated, “When it comes to student performance on reading and math tests, teachers are estimated to have two to three times the effect of any other school factor, including services, facilities, and leadership” (para. 2). While district and school administrators certainly understand the impact teachers have on student performance, little has been done to mitigate the issue of teacher absenteeism, which has become …

The Impact Of Prior Pandemic Planning On Health Outcomes During The Covid-19 Pandemic: A Study Of Local Government Pandemic Planning In The United States, Karissa D. Bergene

Theses and Dissertations

In late 2019, scientists discovered a novel strain of coronavirus originating out of Wuhan, China. By January 2020, the United States (U.S.) saw its first positive case of coronavirus and the public was still unsure how serious of an epidemic this would be. By the time the World Health Organization declared the novel coronavirus disease (COVID-19) epidemic a “global pandemic” on March 11, 2020, world leaders, public health experts, scientists, and public administrators kicked into high gear to start serious pandemic response efforts. The public sector is typically the responsible authority for the preparedness, response, mitigation, and recovery of such …

Stream Water Quality Under Baseflow Conditions In A Livestock Production Area, Maryi Lorena Chavarro Chaux

Theses and Dissertations

This study evaluates the spatial and temporal impacts of implemented Best Management Practices (BMP) on stream water quality under baseflow conditions in a stream segment affected by livestock production. The BMPs includes 10-m fenced riparian zone and crossing paths along the reach segment. Grab water samples and water quality monitoring were collected biweekly from July 2019 to March 2022. Water quality parameters included temperature, dissolved oxygen, electric conductance, total dissolved solids, turbidity, and pH. Water samples were lab analyzed for sediments and nutrients. Results evidenced poor water quality before BMPs implementation, with nutrient concentrations exceeding the nation's and state's criteria. …

Advancing Salamander Conservation Efforts In Zoos And Aquaria Through Assisted Reproductive Technologies (Art), Devin Marie Chen

Theses and Dissertations

Salamanders are one of the most at-risk taxa in the world due to habitat destruction, pollution, climate change, invasive diseases, and more. This has led to a need for conservation breeding programs that are often associated with zoos and aquaria. Salamanders can be difficult to breed in captivity, though, due to their dependence on specific environmental cues and other unknown factors that stimulate sperm and egg production. To overcome these challenges, assisted reproductive technologies (ART) such as exogenous hormone administration, sperm cryopreservation, and in-vitro fertilization have been developed to increase offspring propagation and maintain genetic diversity. If genetically robust populations …

We Built This Country For Free – Using A Phenomenological Approach For (Re) Imagining Mississippi Black Small-Scale Farmers, Destiny Denise Crockett

Theses and Dissertations

By the early 20th century, in 1920, Black farmers owned 14% of US farmland. Today, in the 21st century, Black farmers own less than 2% of US farmland. The demise of Black farmers and Black farmland in US Agriculture is a direct result of social, political, and racial weaponization against their foodways, culture, and livelihoods. The history concerning the plight of Black farmers goes beyond USDA's historical discrimination but enters a position where racism is embedded and perpetuated within the structure of US agriculture. In effect, Black small-scale farmers have reaped the downfall of this system, enduring racial biases and …

A Conceptual Decentralized Identity Solution For State Government, Martin Duclos

Theses and Dissertations

In recent years, state governments, exemplified by Mississippi, have significantly expanded their online service offerings to reduce costs and improve efficiency. However, this shift has led to challenges in managing digital identities effectively, with multiple fragmented solutions in use. This paper proposes a Self-Sovereign Identity (SSI) framework based on distributed ledger technology. SSI grants individuals control over their digital identities, enhancing privacy and security without relying on a centralized authority. The contributions of this research include increased efficiency, improved privacy and security, enhanced user satisfaction, and reduced costs in state government digital identity management. The paper provides background on digital …

“I Tell It Like It Is, Then How It Could Be”: Public Discourse And Public Administration In Popular American Music Since The 1990s, Kristen Dechert

Theses and Dissertations

This study is an analysis of lyrics from popular American music albums since the 1990s to understand public discourse about and experience with public administration. Albums included in the study came from two prominent sources: Billboard and Pitchfork decade-end lists. The study is framed by critical, postmodern, and responsiveness theories, methodologically grounded in critical discourse analysis, and technically approached using standard qualitative methods, including especially qualitative content analysis and iterative, inductive coding techniques. Findings from the qualitative study demonstrate public discourse on the themes of institutional and systemic racism and violence within and perpetuated by public administration and public institutions. …

Factors In Depopulation Trends Among Young Adults In Rural Areas In Mississippi, Katherine H. Ellard

Theses and Dissertations

The purpose of this study was to determine why young adults are leaving rural Mississippi towns and not returning to those areas. Research objectives were to 1) describe the characteristics of young adults who have left rural areas in the last ten years , 2) identify specific reasons why young adults choose to leave where they were raised, and 3) identify factors that would attract young people to return to rural areas in Mississippi.

Findings from this study indicated young adults were leaving rural areas for better educational and job opportunities, but some were relocating to other areas within Mississippi …

The Influence Of At-Planting Insecticide Treatments On Tobacco Thrips, (Thysanoptera:Thripidae), And Reniform Nematode, (Tylenchida:Hoplolaimidae), In Conventional And Thryvon Cotton Systems, Walker Brett Farmer

Theses and Dissertations

One of the objectives of this research was to evaluate the need for an additional imidacloprid seed treatment on ThryvOn^® (Bayer Crop Science^®, St. Louis, MO) cotton to effectively manage tobacco thrips, Frankliniella fusca (Hinds). While evaluating thrips densities and damage ratings, ThryvOn cotton continued to display reduced damage and thrips populations than non-ThryvOn. Thrips populations and damage ratings were consistently reduced when incorporating a higher rate of imidacloprid, but they were not reduced enough to justify the higher rates of imidacloprid. Another objective of this research was to evaluate the impact of aldicarb (AgLogic Chemical^{® …}

Improved Methodology For Conducted Emi Assessment Of Power Electronics And Line Impedance Measurement, Mark Anthony Didat

Theses and Dissertations

Electromagnetic Interference (EMI), primarily common mode (CM), is problematic in a wide range of electronic circuits due to its propensity to radiate, particularly in high power applications. It is routine for much effort and resources to be dedicated to its characterization and reduction as EMI compliance is a requirement for most electronic systems and devices, including power electronics. Many well-known factors contribute to a system’s EMI performance including intentional coupling from system components as well as unintentional coupling from parasitics. Sources of intentional coupling may include Y-capacitors intended to mitigate EMI as part of a filter. Unintentional coupling is more …

Does Mississippi School Principals’ Age, Race, Gender, Educational Attainment, Work Experience In Education, Or Evaluation Scores Influence Accountability Points?, Braxton Dywayne Stowe

Theses and Dissertations

Traditional research agrees that only effective school principals can fully influence student achievement, and school leaders are pivotal to the success of schools in America. Researchers have linked positive student outcomes to further illustrate the point, including student achievement, to high-quality school leadership. The purpose of this study is to assist state and district education leaders in Mississippi in having a more profound knowledge of which principal demographics and characteristics are more directly correlated with the improvement of accountability scores or student achievement. The results of the correlational and regression analysis to determine the relationship between principal variables and the …

Geospatial Integrated Urban Flood Mapping And Vulnerability Assessment, Md Tazmul Islam, Md Tazmul Islam

Theses and Dissertations

Natural disasters like flooding have always been a big problem for countries around the world, but as the global climate changes and the number of people living in cities keeps growing, the threat of flooding has become a lot worse. Even though many studies have been conducted on flood mapping and vulnerability assessment in urban areas, this research addresses a significant knowledge gap in this domain. First, we used a flood depth estimation approach has been used to address the overestimation of urban flood mapping areas using Sentinel-1 images. Ten different combinations of the two initial VH and VV polarizations …

The Migration Ecology Of North American Turkey Vultures Wintering In The Neotropics: Spatial And Population Dynamics, Adrián José Naveda-Rodríguez

Theses and Dissertations

The spatial and population dynamics of avian scavengers are poorly understood. This information is key for management and conservation interventions that guarantee long-term species conservation. My goal in this dissertation is to fill information gaps on the movement ecology of New World vultures using the Turkey Vulture (Cathartes aura) as a model species. I used a continental-wide satellite telemetry dataset to study the migration ecology, space-use, and demography of the three North American breeding populations of Turkey Vultures wintering in the Neotropics during a 17-year period. I found that primary productivity, but not weather, triggered Turkey Vulture migratory …

Developing A Precision Agriculture Framework To Assess Financial Viability Of Decisions In Farming And Conservation, Jennifer Sublett

Theses and Dissertations

Agricultural producers are invested in managing the impacts of crop damage on their yields and profit. When damage occurs early enough in an agricultural growing season, farmers have the option to replant their corn stand in an effort to recoup some of the lost profits. In this thesis two different types of naturally occurring damage, wildlife depredation and persistent weed or insect patches, were simulated on two representative regions of Mississippi. These data were then used to assess the financial viability of a range of damage mitigation methods, including partial replanting, enrollment into a government conservation buffer, and no action. …

Habitat Utilization Of Marsh And Adjacent Submerged Landscape By Fish And Macroinvertebrates In A Gulf Of Mexico Tidal Oligohaline Environment, Tia Offner

Theses and Dissertations

Estuarine habitats are considered nursery habitats for fishes and invertebrates, but oligohaline environments are critically understudied. Using a seine net and fyke nets, we sampled Back Bay, Mississippi (USA), a low salinity estuary, once a month for a year to explore the temporal use of the marsh and adjacent submerged landscape by nekton species. We also looked at whether there is evidence of habitat preference in the most numerous nekton species. We used a novel habitat usage index (HUI) to compare seine and fyke net catches of our top 10 species, and evaluated catch size in relation to maturation size. …

Assessing The Relationship Between Soil Health/Quality And Water Quality In The Mississippi Delta, Laura Andrea Sarmiento Rodriguez

Theses and Dissertations

Several studies have reported agronomic benefits by improving soil health/quality, but uncertain knowledge remains when determining specific impacts on water quality off-field. This study investigated the links between runoff water quality and soil health/quality in agricultural fields of the Mississippi delta under three land management scenarios: Conservation Reserve Program (CRP), vegetative buffer (VB), and row crops (RC). Using the Soil Management Assessment Framework (SMAF), a Soil Quality Index (SQI) was obtained based on ten soil health/quality indicators from 2008 and 2012 datasets. The SMAF identified significant differences in soil health/quality improvements among scenarios over a four-year period. Varied relationships between …

Current And Future Perceived Needs And Concerns For Older Adults Aging In Place In Mississippi: Intergenerational Perspectives, Muhammad Riaz

Theses and Dissertations

The study's purpose was to identify the perceived needs and concerns of three generations in a family with an older adult aging in place in Mississippi. This mixed-methods study used snowball sampling in addition to recruitment by community leaders such as Extension agents to collect data through semi-structured interviews and structured questionnaires that asked about current and future problems among aging adults in rural communities in Mississippi. Three generations of Mississippians participated in the study, including older adults (G1; n = 22), adult children (G2; n = 23), and young adult grandchildren (G3; n = 19). Quantitative data were analyzed …

Evaluating Teachers’ Perceptions Of The Social Validity Of Psychological Report Writing Styles, Adam Weseloh

Theses and Dissertations

Psychologists spend a significant portion of their time writing psychological reports. Oftentimes these reports are highly technical and written at a level which the literature has suggested is often difficult for teachers to utilize in their classrooms. Several previous research studies have examined psychological report writing practices and offered suggestions for improvement. One of these suggestions (theme or referral-based report writing) has not been as thoroughly examined in the literature. The purpose of this study was to examine this report writing style compared to more traditional report writing practices. This study utilized a novel approach to assessing teachers’ perceptions of …

Morphological And Structural Characterization Of Shortening Landforms On Mars, Leta Mccullough

Theses and Dissertations

The lithosphere of Mars accommodates shortening through folding and faulting, producing landforms qualitatively categorized as wrinkle ridges or lobate scarps. However, we lack a deep understanding of the morphological differences between these landforms. This study aimed to develop a quantitative model for shortening landform classification based on surface morphology and subsurface architecture. We developed this model by mapping 100 landforms in a GIS, recording parameters for each landform. We conducted a Discriminant Function Analysis (DFA) using these morphometrics. This DFA produced a predictive linear function for categorizing wrinkle ridges and lobate scarps. We then modeled the subsurface structural geology of …

Advancements In Time Resolved Spectroscopy And Nonlinear Microscopy, Bryan Semon

Theses and Dissertations

Non-linear optical processes such as coherent anti-Stokes Raman scattering and sum frequency generation offer a view into the chemical and biological interactions of molecules that is distinctly different from linear techniques like near infra-red and fluorescence. This insight comes at a cost: non-linear techniques are more sensitive to external perturbations of the system, increasing the noise and decreasing the repeatability of the data. We work here on both aspects of these non-linear techniques, taking advantage of their power to offer new imaging techniques as well as working to quantify and reduce the non-resonant noise inherent to the system. In pursuit …

Probing The Biophysical Interactions Between Autolysin Proteins And Polystyrene Surfaces, Radha Paramee Wadduwage

Theses and Dissertations

Biofilms formed on medical devices pose significant challenges, compromising device efficiency and serving as sources of infection. Staphylococcus epidermidis, an opportunistic pathogen, relies on the autolysin protein, notably its R2ab and amidase domains, to attach to polystyrene surfaces and initiate biofilm formation. Despite their pivotal role, the structural intricacies of these proteins’ interactions with surfaces remain elusive. In this dissertation, the multifaceted aspects of protein interactions with polystyrene surfaces and the implications of these interactions for biofilm control are studied. Over the course of this study, it is found how the R2ab and amidase domains influence biofilm formation on polystyrene …

Biochar And Gypsum Effects On Soil Properties And Water Quality In Cotton And Soybean Production Systems In The Mississippi Delta, Amrinder Jakhar

Theses and Dissertations

Intensive tillage practices in the Mississippi Delta degrade soil health, impacting downstream water quality. To address this, two experiments were conducted from 2019 to 2021 and 2020 to 2022 to evaluate the impact of sugarcane biochar and flue gas desulfurization (FGD) gypsum on nutrient leaching losses and soil properties in cotton and soybean cropping systems. Study I applied four biochar rates (0, 10, 20, and 40 Mg ha^-1) to cotton and found improvements in soil properties and subsurface quality, with reduced nutrient leaching losses, except for sulfate and sodium ions. Study II evaluated biochar (10 and 25 Mg …

Green Wood Composites With Natural Preservatives, Thomas Frank Norman

Theses and Dissertations

The purpose of this study is to test the mechanical, dimensional stability, and weathering durability of OSB (oriented strand board) panels that have been treated with varying natural wood preservatives that were chosen from an array of natural antimicrobial compounds. Wood is increasing in popularity for new construction projects but has been limited by its vulnerability to biological degradation. The addition of natural antimicrobial compounds will increase the use life of wood-based strand board allowing its use to expand with the growing construction demand but has little data on how natural antimicrobial compounds impact different properties of the OSB. The …

An Assessment Of Loblolly Pine (Pinus Taeda L.) Mortality And The Impact Of Habitat Fragmentation On Southern Pine Beetle (Dendroctonus Frontalis Zimmerman) Infestation In Mississippi, Usa, Damilola M. Taiwo

Theses and Dissertations

This thesis has two data chapters that consider factors affecting loblolly pine health in localized regions of Mississippi. The first data chapter investigated the abiotic and biotic factors contributing to loblolly pine (Pinus taeda) mortality on private timberland in Mississippi. This assessment considered temperature and precipitation variations, bark beetle populations, foliar and root pathogen tests, and drone survey. The results revealed that the loblolly pine mortality resulted from combination of factors. The second data chapter examined the impact of habitat fragmentation on southern pine beetle (SPB; Dendroctonus frontalis) infestation in Homochitto National Forest (HNF). This was assessed through remote sensing …

Paternal Programming: The Role Of Seminal Plasma In Pregnancy Hemodynamics And Offspring Growth, Rebecca Michele Swanson

Theses and Dissertations

Seminal plasma is commonly known to serve as a transport medium for sperm as it moves through the female reproductive tract for fertilization, however, more recent evidence demonstrates seminal plasma induces an expansive inflammatory response in the uterus. Murine models have found this inflammatory response is important for clearing pathogens and poor-quality sperm, eliciting the secretion of cytokines, chemokines, and embryokines that aid in embryo attachment and growth, placental angiogenesis, and blunting maternal immunity to the embryo. However, there is minimal research on the impacts of seminal plasma uterine priming in bovine, and more specifically embryo growth, uterine blood flow, …

Mechanical Characterization Of Functionally Graded M300 Maraging Steel Cellular Structures, Bradley Jay Sampson

Theses and Dissertations

Traditional methods for increasing the energy absorption of a structure involve using a stronger material or increasing the volume of the structure, resulting in a higher cost or additional weight. Additive manufacturing (AM) can be used to maximize the energy absorption of materials with the ability to create complex geometries such as cellular structures. Previous work has shown that the energy absorption of additively manufactured parts can be improved through functionally graded cellular structures; however, this strategy has not been applied to ultra-high strength steel materials. This work characterizes the effect of multiple functional-grading strategies (e.g. uniform, rod-graded, size-graded) on …