Digital Commons Network^™

Heat And Mass Transfer Modeling Of High-Temperature Moving-Bed Thermochemical Reactors, David Korba

Theses and Dissertations

With the global deployment of renewable energy generation at record rates, clean energy is steadily becoming competitive with its fossil-fuel counterparts. However, further expansion is limited by the inherent intermittency of renewable energy sources (solar, wind, wave, etc.), which typically do not match with daily and seasonal variations of global (and local) energy demand. Thermochemical energy storage (TCES) has demonstrated strong potential in being a technological pathway to provide on-demand process heat and handle the intrinsic variations in renewable energy generation and energy demand. TCES works on the premise of excess renewable heat driving an endothermic reduction reaction, in which …

Metabolic Adaptation Of Staphylococcus Aureus Pathogenesis And Therapeutic Approach In Diabetic Foot Ulcers., Carol L. Baker

Theses and Dissertations

37.3 million Americans (11.2% of the US population) currently have Type 2 diabetes mellitus (T2DM) with over 1.5 million new cases being diagnosed each year. The multifactorial etiology of the patient having neuropathy, overweight/obesity, foot deformities, ischemia, and infection leads to a condition called diabetic foot ulcer (DFU). One in six patients with a DFU will require amputation with infected DFUs have a 155-fold increased risk of amputation. Staphylococcus aureus is the most common bacteria isolated from severe DFU infections that require amputation. Interestingly, diabetics are more heavily colonized with S. aureus compared to non-diabetics suggesting a unique advantageous adaptation …

The Cosolvent And Association Effect On Polymer Behaviors, Xiangyu Zhang

Theses and Dissertations

The blending or mixing is extensively utilized in diverse processes of polymers to bring about advantageous properties, but the behavior becomes intriguing when associations are involved and multi-solvents are used. Explanations based on chemistry-specific arguments are less than satisfactory in abstracting essential features, and lack the general applicability across various systems. So, this work focuses on capturing the physical force governing the phenomenon of interest by using a generic model. Highly non-trivial behaviors of polymers are often observed in multi-solvent solutions. It is known that polymers swell and dissolve in good solvents, while they tend to collapse and aggregate in …

Effects Of Parkinson’S Disease On Motor Asymmetry, Deborah Mazanek Watson

Theses and Dissertations

Introduction: Persons with Parkinson’s disease (PD) experience changes cortically, subcortically and behaviorally. This dissertation examines the asymmetry of motor behavior to explore the role of asymmetry in persons with PD and its connection to clinical symptoms. Purpose: Project 1: To assess the hand asymmetry difference in young adults versus older adults. Project 2: To investigate the difference in hand asymmetry in older adults and persons with PD. Project 3: To explore the correlation between function and clinical symptoms of persons with PD. Methods: 55 right-handed participants [Young Adults (YA) = 20, Female = 10; Older Adults (OA) = 20, Female …

Tuning The Metal/Acid Functionalities In Hzsm-5 For Efficient Dehydroaromatization, Genwei Chen

Theses and Dissertations

The increasing production of natural gas liquids attracts both academia and industry to develop on-purpose techniques converting those light alkanes to value-added chemicals. Dehydroaromatization is an alternative path for light alkane conversion to produce aromatics but still lacks active and stable catalysts. This work aims at the development of efficient dehydroaromatization catalysts by tuning the metal/acid bifunctionality of the Pt/HZSM-5 catalyst. Additionally, through co-processing light alkane with ammonia during the dehydroaromatization process, this study also proposes a new reaction system that could directly link the C-N bond for nitrile synthesis.

The results suggested that the activity, selectivity, and stability of …

Self-Referential Processing And Depression: A Systematic Review And Meta-Analysis, Amanda Collins

Theses and Dissertations

Cognitive theories of depression, including Beck’s Cognitive Theory, suggest that depressed individuals hold negative schemas about themselves and their environment. These negative schemas may influence the extent to which depressed individuals process positivity. Reward Devaluation Theory posits that depressed individuals avoid and devalue positivity. This suggests that depressed individuals may be less likely to hold positive schemas, or may be more likely to associate positivity with negativity. Previous meta-analytic reviews suggest that this is potentially the case, but have not assessed for self-referential stimuli. Self-referential encoding and recall tasks assess for self-schemas and may give further insight into how depressed …

Evaluating The Immunogenicity Of Colonization Proteins Of S. Pneumoniae For Identification Of Vaccine Candidates, Isidora Fereday

Theses and Dissertations

Streptococcus pneumoniae is typically an asymptomatic colonizer of the upper respiratory tract but can cause invasive disease in susceptible populations. Pneumococcal vaccines which are currently in use have failed to significantly reduce colonization by S. pneumoniae. To control invasive pneumococcal disease, novel strategies must be utilized. One such strategy is to reduce or eradicate colonization by pneumococcus. Supplementary vaccination with pneumococcal proteins important for colonization could serve to prime the immune system against these targets. This study serves as an initial step towards identification of crucial pneumococcal colonization proteins which may previously have been uncharacterized. Assessing the immune reactivity …

Physical Layer Security With Unmanned Aerial Vehicles For Advanced Wireless Networks, Aly Sabri Abdalla

Theses and Dissertations

Unmanned aerial vehicles (UAVs) are emerging as enablers for supporting many applications and services, such as precision agriculture, search and rescue, temporary network deployment, coverage extension, and security. UAVs are being considered for integration into emerging wireless networks as aerial users, aerial relays (ARs), or aerial base stations (ABSs). This dissertation proposes employing UAVs to contribute to physical layer techniques that enhance the security performance of advanced wireless networks and services in terms of availability, resilience, and confidentiality. The focus is on securing terrestrial cellular communications against eavesdropping with a cellular-connected UAV that is dispatched as an AR or ABS. …

Fabrication And Imaging Of Highly Ordered Plasmonic Au Nano-Prism And Self-Assembled Supramolecular Nanostructure, Ridwan Tobi Ayinla

Theses and Dissertations

The precise control of the resonance frequency of plasmonic nanostructures is critical and depends on the size, composition, shape, and dielectric nature of the environment. The ability to control the shape and size of nanomaterials acutely depends on the fabrication technique and material design. We used a cheap and scalable method known as nanosphere lithography (NSL) to fabricate plasmonic nano-prism (NP) on glass and indium tin oxide substrate (ITO). The methods involve substrate hydrophilicity treatment, polystyrene nanosphere masking, metal deposition, and mask removal. The array and specific morphology of the fabricated NP was established using scanning electron microscope (SEM) and …

What Makes Firms Survive Longer? A Survival Analysis Using Hazard Function For Mississippi Establishments, Sabin Dawadi

Theses and Dissertations

This study investigates the influence of regional factors on firm survival, with a particular focus on the startup and growing phases of firms. By employing Cox-proportional hazard models, the analysis centers on Mississippi establishments and considers regional attributes such as industry specialization, diversity and workforce education levels. The findings reveal that industry specialization does not significantly impact firm survival, while industry diversity has a negative effect, indicating a lack of discernible agglomeration benefits within Mississippi's business environment. Interestingly, regions characterized by educated and skilled workers exhibit a positive association with firm survival, particularly in the growing stage rather than during …

Transition Metal-Catalyzed Functionalization Of Carbon-Hydrogen Bonds In Alkenes, Xiaolin Qian

Theses and Dissertations

Alkenes can undergo a variety of chemical reactions to form more complex molecules with a range of functional groups. This makes them useful starting materials for synthesizing a wide range of organic compounds. Chapter I provided an overview of the development history of alkenyl C−H bond activation. The early reactions of C−H compounds with metal complexes, as well as stoichiometric activation of the transition metal-activated C–H bond, were discussed. Then the first successful and efficient organometallic-catalyzed transformations of a C−H bond, the first transition metal-catalyzed vinylic C–H functionalization, and the first transition metal-catalyzed olefinic C–H functionalization under mild conditions were …

Exponential Runge–Kutta Time Integration For Pdes, Trky Alhsmy

Theses and Dissertations

This dissertation focuses on the development of adaptive time-stepping and high-order parallel stages exponential Runge–Kutta methods for discretizing stiff partial differential equations (PDEs). The design of exponential Runge–Kutta methods relies heavily on the existing stiff order conditions available in the literature, primarily up to order 5. It is well-known that constructing higher-order efficient methods that strictly satisfy all the stiff order conditions is challenging. Typically, methods up to order 5 have been derived by relaxing one or more order conditions, depending on the desired accuracy level. Our approach will be based on a comprehensive investigation of these conditions. We will …

Vaccination And Immune Response Of Channel Catfish (Ictalurus Punctatus) Against Virulent Aeromonas Hydrophila, Basant Mahmoud Ali Gomaa

Theses and Dissertations

Virulent Aeromonas hydrophila (vAh) is a causative agent of motile Aeromonas septicemia (MAS) in catfish. There are limitations in the current therapeutic and preventative strategies against vAh. The pathogenesis of MAS as well as the immune response of catfish to vAh infection are poorly understood. The aim of this study is to: 1) develop a dual live attenuated vaccine against MAS and enteric septicemia of catfish caused by Edwardsiella ictaluri; and 2) evaluate the vAh bacterial load and gene expression patterns in catfish tissues following vAh infection. Previously, six recombinant vAh …

Dog Tired: Examining The Relation Between Dog And/Or Cat Ownership And Owners’ Sleep, Courtney J. Bolstad

Theses and Dissertations

Sleep is an essential part of life, and obtaining quality sleep is important for various areas of functioning. Behaviors to promote sleep include physical activity, managing stress, reducing anxiety symptoms, maintaining a consistent sleep schedule, and obtaining bright light exposure. Many of these behaviors overlap with benefits observed from pet ownership (PO). The present study aimed to examine the relation between PO and sleep as well as moderators and mediators of this relation. Four research questions were examined: 1) Is PO significantly related to sleep? 2) Does gender moderate the relation between PO and sleep? 3) Do sleep-promoting behaviors (i.e., …

Teachers’ Perceptions Of Teacher Incentives On District Attendance Incentive Programs And Their Impact On Improving Overall Teacher Attendance, Ginger Hearon Cockrell

Theses and Dissertations

Teacher absenteeism is a problem that needs a solution. It is imperative that teachers come to work each day to prepare their students for academic achievement. If teachers are chronically absent from work, the students’ academic achievement suffers. There needs to be a way to minimize teacher absences. School districts must track data that shows teacher absences in order to get a clear picture of when and where the absences are the greatest problem.

A review of the literature identified several studies conducted over the years that document the effects of teacher absenteeism. With this in mind, it is recommended …

Evaluation Of Occidiofungin Activity On Yeast-Hyphae Morphogenesis And Biofilm Formation By Candida Species, Rabina Kumpakha

Theses and Dissertations

Invasive fungal infections are a significant clinical challenge especially for hospitalized patients as traditional antifungal therapy often fails to resolve these infections. The ability of Candida to undergo yeast-to-hyphae morphological transition is central to this invasive behavior. Morphogenesis is also important for the formation of biofilms which are highly structured communities of microorganisms attached to one another or substratum and embedded within a protective extracellular matrix material. The refractory nature of cells within a biofilm to current antifungal therapies has created a need for alternative antifungal agents for the management of Candida biofilm-related infections. The novel antifungal occidiofungin is a …

Investigating Specialty Crop Farmers’ Preferences For Contract Design And Attitudes Towards Blockchain-Based Smart Contracts, Esther Mmenaa Agyemang-Duah

Theses and Dissertations

This study examines small and medium scale specialty crop growers’ preferences for marketing contract attributes and willingness to adopt blockchain-based smart contracts. The data used were collected using an online survey and discrete choice experiment. Findings indicate that farmers prefer higher average prices, cash, check or electronic bank payment over cryptocurrency, and immediate payment upon product delivery over delayed payment. When choosing a contract, farmers viewed traditional text-based contracts and digital platforms with automated smart contracts equivalently, on average. On average, farmers showed no preference for providing and not providing traceability lot codes to buyers, and between choosing a contract …

Philosophies Of Mississippi College Readiness Programs, Cory Ellis Bailey

Theses and Dissertations

“College Readiness” has been a phrase discussed across higher education and the workforce in most recent years. However, the perception of College Readiness has been debated throughout history as there is not a universal agreement on the philosophy of what it means to be College Ready. In Mississippi, the state has not even defined this phrase so there is not a way to measure the success of College Readiness. Because of this lack of universal philosophy, the purpose of this study is to understand the philosophy of college readiness programs in the state of Mississippi. The research question guiding this …

Nutritional Strategies To Reduce Salmonella Enteritidis Infections In Laying Hens: Prebiotic, Probiotic, And Precision Biotics, Ishab Poudel

Theses and Dissertations

Salmonella Enteritidis (SE) infections in laying hens is a significant cause of foodborne illness linked to the consumption of contaminated eggs. This dissertation encompasses novel strategies aimed to explore appropriate in-vitro and in-vivo models to evaluate the effects of these novel strategies to reduce SE in laying hens. Firstly, we investigated the potential probiotics, prebiotics, and essential oil combinations to reduce SE in-vitro. The results showed that probiotics and prebiotics are equally effective to reduce SE. In subsequent studies, we evaluated the role of vaccination history on cecal microbiota and SE infections with various doses of oral SE challenge. …

Effectiveness Of Intervention Studies Based On Diet And/Or Physical Activity In Treatment, Prevention, And Management Of Diabetes Among South Asians: A Systematic Review, Ishaan Arora

Theses and Dissertations

The purpose of this study was to describe diet and/or physical activity-based interventions and their control in cardiometabolic risk factors of diabetes for the South Asian (SA) population. A systematic review was conducted in accordance with the PRISMA guidelines. Seventeen randomized control trials meeting the inclusion criteria were included for analysis. Interventions with type-2 diabetic SA showed significant improvements in HbA1c% (4/5 studies), fasting blood glucose (3/4 studies), and postprandial glucose (2/2 studies). Interventions with at-risk/prediabetic and non-diabetic SA showed a modest change in overall outcomes, with significant change reported for post-prandial insulin (3/4 studies), BMI and weight (2/4 studies), …

Assessing The Effectiveness Of Agricultural Extension Advice On Household Food Consumption And Food Security Outcomes In Malawi, Mphatso Chinsinga

Theses and Dissertations

My study examined the influence of agricultural extension advice on household food consumption and food security outcomes in Malawi. I utilized a pooled cross-sectional dataset from the Malawi Integrated Household Survey (IHS) and Integrated Household Panel Survey (IHPS) conducted in 2010, 2013, 2016, and 2019. To identify the effects, multivariate linear and logistic regression models were employed, considering various factors and incorporating fixed effects for survey wave, district, and data collection month. My findings revealed heterogeneity in the impacts of agricultural extension advice on food consumption and food security outcomes. Specifically, the results showed a positive correlation between agricultural extension …

Regional Economic Impacts Of Enterococcus-Related Beach Closures In Mississippi, Jessica Lynn Browne

Theses and Dissertations

High levels of Enterococcus are the most frequent reason for beach closures on the Mississippi Gulf Coast and can be made worse by human activities. When beaches close, tourism can decrease, affecting sales. This study aims to 1) analyze the regional economic impact of beach closures at the county level, 2) show empirically how serious the impact of high levels of Enterococcus are compared to other causes of beach closures, and 3) discuss the policy implications for regional economies linked to beach closures. I use a response function approach with beach closure and county-level monthly gross taxable sales data. Results …

Optimizing Edge-Of-Field Water Quality Monitoring Methods To Determine The Effects Of Best Management Practices On Nutrient And Sediment Runoff, Mark Hill

Theses and Dissertations

This study investigates the impact on water quality of combined agricultural best management practices cover crop and minimum tillage, alongside an examination of techniques used to collect those samples. Edge-of-field (EOF) water quality samples were collected from 11 working farms during a two-year paired field experiment. Results showed significant reductions in nutrient concentrations, increased discharge, and mixed findings regarding nutrient mass transport post-treatment. A suite of EOF collection techniques were compared using in-situ automated water sampling systems sampling the same runoff events. Sampling protocols influenced nutrient concentrations in composite samples, but unexpected variance in velocity sensors affected measured discharge, making …

Improved Stoichiometric Synthesis Of Ccc-Nhc Pincer Rh Complexes And Catalytic Activity Towards Dehydrogenative Silylation And Hydrosilylation Of Alkenes, Enock Amoateng

Theses and Dissertations

N-Heterocyclic carbenes (NHCs) have attracted growing interest not only as successful ancillary ligands in a wide variety of transition-metal-catalyzed reactions but have also shown to offer photophysical and electrochemical properties. The metalation/transmetalation strategy using [Zr(NMe₂)₄] as initial metalating reagent offers an efficient approach to the preparation of CCC-NHC pincer complexes of the late transition metals such as Rh and Ir. In the process of investigating an intermediate and the mechanism of the metalation/transmetalation to Rh sequence, a mixed valent bimetallic CCC-NHC pincer Rh complex with two chloro ligands bridged between a [(CCC-NHC)Rh(III)] and a [Rh(I)(COD)] fragment …

Direct Measurement Of The 114cd(N, Gamma)115cd Cross Section In The 1 Ev To 300 Kev Energy Range, Kofi Tutu Addo Assumin-Gyimah

Theses and Dissertations

The large thermal cross section of cadmium makes it ideal for many practical applications where screening of thermal neutrons is desired. For example, in non-destructive assay techniques, or for astrophysical studies of the s-process. All such applications require precise knowledge of the neutron-capture cross section on cadmium. Although there are some data on neutron-capture cross sections particularly at thermal energies and at energies relevant for astrophysics, there is very little data at most other energies. Further, the evaluated cross sections from the ENDF and JENDL databases disagree at high energies. Therefore, there is a critical need for precise knowledge of …

Valuation Of Oyster Reef Restoration Along The Gulf Coast, Freedom Enyetornye

Theses and Dissertations

The objective of this study is to estimate the willingness to pay of U.S. Gulf Coast residents to support oyster reef restoration. The Gulf Coast is the leading commercial oyster- producing region in the United States, accounting for approximately 46% of the total commercial oyster harvest in 2021. My benefit estimates were based on data obtained from a contingent valuation survey of 6,475 Gulf Coast respondents. I estimated the willingness to pay (WTP) for oyster reef restoration using interval regression and Turnbull lower-bound methods. The estimated mean WTP value is in the range of $142 and $436 per household. The …

A Four-Pronged Approach To Addressing A Wild Pig Invasion In A Bottomland And Upland Forested Landscape, Tyler Scott Evans

Theses and Dissertations

Among exotic species that are capable of invading, establishing, and reaching pest status, few pose the range of impacts to biotic (e.g., competition with native species, predation, herbivory, introduction of other exotics) and abiotic (e.g., soil, hydrology) ecosystem components that can be attributed to the wild pig (Sus scrofa). Despite the presence of wild pigs throughout the southeastern United States for centuries, new invasions continue to occur in previously uninhabited and often under-investigated landscapes, including bottomland and upland forests. The recent invasion of the Sam D. Hamilton Noxubee National Wildlife Refuge (hereafter, NNWR) in east-central Mississippi represents an …

Impacts Of Cover Crop, Soil Steaming, And Plastic Mulch On Field-Grown Tomato Production And Virus-Induced Gene Silencing In Antirrhinum, Penstemon, Petunia, Rosa, And Rudbeckia, Brenton Andrew Earl Breland

Theses and Dissertations

Weeds and soil-borne diseases can cause large yield losses in field-grown tomato (Solanum lycopersicum) production. Techniques have been developed to reduce soil-based problems. In this study, we evaluated the impacts of cover crops, soil steaming, and plastic mulch to reduce weed and disease pressure in field-grown tomatoes. Four cover crop treatments were grown in the fall and winter before spring planting. Soils were steamed to a target temperature of 71.1 °C for 0, 5, or 20 minutes. Plastic mulch was also used on half of the rows. Yield, weed densities, and disease incidence were recorded.

Reduced flowering time …

Effects Of Adding Graphene-Based Nano Materials On Cure Time And Bond Strength Of Adhesives, Bradia T. Henfield

Theses and Dissertations

This research took place in 3 stages. In the first stage, lignin graphene (LG) was synthesized using a catalytic thermal conversion process. In stage 2, the time and temperature correlations for polyvinyl acetate (PVAc) and phenol resorcinol formaldehyde (PRF) adhesives were found and PRF showed stronger correlation when doped with carbon nanomaterials. Stage 3 evaluated the effect of the nanomaterials on radio frequency (RF) heating time and adhesive strength. It was found that all versions of the PRF adhesive resulted in higher shear strength values when cured in room temperature for 24 hours or in an oven at 170 °F …

The Community Ecology Of Ants On The Cumberland Plateau And A Taxonomic Redescription Of The Genus Stenamma Westwood, 1839 (Hymenoptera: Formicidae: Myrmicinae) In A Southeastern Treatment, Zachary Brown

Theses and Dissertations

Grassland communities represent major biodiversity hotspots across the United States. Among these grassland types is the short-leaf pine savanna, a major historical habitat along the Cumberland Plateau. The Cumberland Plateau’s grasslands are under threat due to land use changes such as urbanization and land conversion to pasture and hardwood forests. This study seeks to better understand the community ecology of ants on the Cumberland Plateau using powerlines as a comparison to degraded and historic habitats. Ants have a preference between open sites and forested sites, a separation of 44.5% on a DCA. The Simpson diversity places the short-leaf pine savanna …