Digital Commons Network^™

Solar Powered Conservation: The Effects Of Solar Photovoltaic Facilities On Avian Community Composition, Michael Christopher Ferrara

Graduate Theses and Dissertations

The expansion of solar photovoltaic energy infrastructure is transforming landscapes worldwide. Increasingly, facilities are planted with native vegetation, yet how vegetation characteristics and landscape variables shape wildlife communities in solar facilities remains poorly understood. Because avian populations have been in decline and are sensitive to habitat changes, understanding how solar facilities influence avian communities is important. In Chapter 1, we used autonomous recording units, local vegetation measurements, and land use and land cover data to quantify how avian community occupancy is influenced by solar cover in solar facilities and comparable reference sites. We used a Bayesian multi-species occupancy model to …

Towards Vision-Brain Understanding At Scales: From Classical To Quantum Machine Learning Approaches, Xuan-Bac Nguyen

Graduate Theses and Dissertations

In recent years, large-scale learning approaches such as unsupervised and self-supervised learning have revolutionized artificial intelligence. These methods enable machines to learn high-level representations without explicit human supervision, achieving remarkable success across vision, language, and multimodal tasks. However, such advances come at a cost—they rely on massive datasets, billions of parameters, and extensive computational resources. Despite these achievements, artificial systems still fall short of the remarkable learning efficiency of the human brain, which can infer, adapt, and generalize from limited experiences. This gap motivates a deeper exploration of how biological intelligence acquires knowledge and how these principles can inspire the …

Predictive Modeling Of Listeria Monocytogenes Growth In Ready-To-Eat Meat Products, Manjari Singh

Graduate Theses and Dissertations

Listeria monocytogenes remains a significant food safety concern in ready-to-eat (RTE) meat and poultry products due to its persistence under refrigerated and stressed conditions. Predictive models play a vital role in risk assessment and food safety management; broth models are highly conservation & results in overprocessing. This thesis focuses on developing and validating meat-specific predictive models for Listeria monocytogenes growth and lag for RTE beef, pork, and poultry products. Matrix-specific secondary models were built to predict the maximum specific growth rate (μmax) of Listeria monocytogenes under varying environmental conditions, including temperature, pH, water activity, salt, organic acids, and nitrites. Growth …

Study And Simulation Of Model-Reference Adaptive Control Via The Heffron-Philips Model For Enhanced Power System Stability, Laila Ayman Dallol

Graduate Theses and Dissertations

Improving power transmission and quality has been an area of research interest over the past decades and was improved using renewable energy resources, mainly wind, and solar generation. Renewable energy penetration into power grids aims to replace some traditional synchronous generators, affecting the overall power system with reduced gas emissions that help with climate change and pollution issues. However, renewable generation in power systems ranging from microgrids to national grids is subjected to large disturbances that affect its transient stability, which is measured by its critical clearing time. As increased amounts of renewable generation connected to power systems have resulted …

Updating The Surface Geological Maps In The Boston Mountains Region Of Arkansas Using Subsurface Well Log Correlation And Lidar Mapping, Olivia Smith

Graduate Theses and Dissertations

The Pennsylvanian Atoka Formation are the primary surface outcrops of the Boston Mountains in northwest Arkansas. Where fully preserved in the Arkoma Basin to the south, the Atoka Formation exceeds 18,000 feet of sandstone and shale. It is mapped as a single “undifferentiated” unit on the surface geological map of Arkansas. This project correlates ten subsurface subdivisions of the Atoka Formation plus the Desmoinesian to the surface outcrops of the southern Boston Mountains. This produced a higher resolution surface map beyond the current Atoka Undifferentiated scheme. Recognition of the Atoka Formation subdivisions in surface outcrops using standard lithostratigraphic and biostratigraphic …

Unraveling Nucleation Mechanisms In Membrane Distillation: A Molecular Dynamics And Enhanced Sampling Approach, Nazanin Abbasi

Graduate Theses and Dissertations

Membrane distillation offers a promising route for desalination but remains limited by salt scaling, where mineral crystals nucleate and grow in concentrated brines. To inform strategies that mitigate scaling, this thesis investigates homogeneous nucleation in supersaturated aqueous NaCl solutions using molecular dynamics and enhanced sampling techniques. Several collective variables (CVs) are tested to capture the early stages of ion aggregation and crystal formation, including ion–ion coordination number, dehydration, and bond orientational order parameters Q₄ and Q₆. Enhanced sampling techniques, such as metadynamics and umbrella sampling, are employed to overcome the high free energy barriers associated with the formation of critical …

Novel Radical Chemistry Of Electron-Rich Double Bonds, Claire Allyson Beard

Graduate Theses and Dissertations

This work delves into the reactivity of nucleophilic N-heterocyclic carbenes (NHCs) and their ability to form electron-rich alkene intermediates, which can undergo various chemical transformations depending on the nature of the electrophile. Initial reports by Hahn disclosed the NHC promoted radical nature of electron-rich N,N’-benzyltetraazafulvalenes, which led to 2,2’- biimidazoles. We found that N-aryl substituted pyridinium salts also underwent rapid a similar NHC promoted dimerization when exposed to a base, producing 2,2’-bipyridyls. This is likely due to the adept radical nature of the bipyridinylidene intermediate for C-Naryl bond scission. We have also uncovered an unprecedented C-N bond scission of Breslow-like …

Contextual Embedding Using Machine Learning For Cybersecurity: Access Control And Application, Thanh Bui

Graduate Theses and Dissertations

Access control is a well-established challenge in cybersecurity, with significant research focused on enhancing system autonomy and accuracy across various scenarios. Access control rules can be designed based on users’ roles, attributes, or relationships requesting access to specific resources. However, despite their benefits, these models still require human oversight. As systems expand and grow, it becomes increasingly complex for administrators to maintain precise access control rules, often necessitating extensive system updates or even a complete overhaul. This dissertation introduces a novel approach that leverages contextual embedding for user information to enable the system to autonomously authorize user requests for resources. …

Ring-Opening And Monofunctionalization Study On Spiro Cyclic Aminals And N, O-Acetals System Via Nitrogen-Centered Radical Intermediates, Chujun Zhou

Graduate Theses and Dissertations

The nitrogen-centered radical has been drawing increasing attention among researchers. Radical polarity is one of the key factors in studying nitrogen-centered radicals’ reactivity, and the functional groups attached to the nitrogen atom are of vital importance. Among different types of nitrogen-centered radicals, aminium radical and metal aminium radical are electrophilic due to the positive charge on the intermediate. The sulfonamide radical, amidyl radical, and cyanide amine radical are also electrophilic since the nitrogen is adjacent to electron electron-withdrawing group. The neutral amino radical, iminyl radical, masked nitrogen radical are nucleophilic because of the electron-donating groups. After classifying the nitrogen-centered radical, …

Multiple Aspects Of Environmental Temperature Have Complex Interactions With Avian Parental Behavior To Influence Offspring Outcomes, William H. Kirkpatrick

Graduate Theses and Dissertations

Anthropogenic climate change is projected to shift not only average temperatures across the globe, but also the amount of thermal variation experienced in the natural environment. Exposure to shifts in averages and a wider range of thermal experiences will cause shifts in wildlife behavior. In avian species, behaviors exhibited during reproduction have implications for the well-being of their offspring. Here, I explore specific incubation behaviors in four species: Scaled Quail (Callipepla squamata), Northern Bobwhite Quail (Colinus virginianus), Tree Swallows (Tachycineta bicolor), and Eastern Bluebirds (Sialia sialis). I examined constancy, or the percentage of time on the nest, and off-bout duration, …

When The Grid Goes Dark: A Digital Forensics Study Of Industrial Control System Cyberattacks, Katie Kettler

Graduate Theses and Dissertations

Industrial Control Systems (ICS) and Operational Technology (OT) maintain the grid, ensure water safety, and keep transportation running. Because they influence nearly every aspect of daily life, these systems have become prime targets for cyberattacks. The need for this research arises from the fact that when ICS and OT systems are compromised, the consequences go beyond data loss, and they can directly disrupt communities and endanger public safety. This thesis introduces digital forensics fundamentals and explains how investigations in ICS environments differ from those in traditional IT environments. This work then examines major attacks, including Stuxnet, the Ukrainian Grid Attacks …

Two Topics In Survival Analysis: Restricted Distance Covariance Test For Non-Proportional Hazard And A New Estimation For Dropout Rate, Ruizhe Yin

Graduate Theses and Dissertations

When treatment effects change over time, standard statistical methods, such as the log-rank test and the Cox proportional hazards model, may give misleading results. This dissertation presents the restricted distance covariance (rdcov) test, a nonparametric method that compares survival curves between groups within a chosen study period [0, τ] using right censored data. The statistic measures the dependence between pre-specified group labels and survival times using pairwise distances from Kaplan-Meier estimates. Our method does not rely on the proportional hazards assumption, and it equals zero only when survival functions are identical across groups. Thus, this test can be applied to …

Design Of Phase Shifter And True Time Delay Gan Mmics For High-Temperature Ku-Band Applications, Michael Lee Thompson

Graduate Theses and Dissertations

This thesis presents the design, implementation, and high-temperature characterization of Gallium Nitride (GaN) monolithic microwave integrated circuits (MMICs) developed for beamforming and phased-array systems operating in the Ku-band (12-14 GHz). Two integrated circuits were designed: a 3-bit digital phase shifter and a 3-bit true time delay (TTD), both optimized for high linearity, low insertion loss, low phase error, and stable operation at elevated temperatures up to 300°C. Developing both a phase shifter and a TTD enabled a direct comparison of their beamforming performance and the evaluation of beam squint effects over frequency, a critical factor in wideband array design. The …

Using Artificial Intelligence (Ai) To Improve The Identification Of Gifted Students, Hamid Ahmad Almalki

Graduate Theses and Dissertations

The present study examined teachers' perceptions of using artificial intelligence (AI) to identify gifted students. The issue is clearly relevant today; several schools continue to grapple with unfair practices and irregular assessment processes, most notably for culturally and linguistically different students. Conventional keys and expert opinion remain essential, but their limitations have been acknowledged. Newer research suggests that AI could actually improve the system by making it more efficient and able to pool data that originally surfaced biases. At the same time, issues of transparency, data privacy, and the ethics of decisions driven by AI remain unresolved. To gain an …

A Practical Framework For Integrating Basic Separation Techniques With Molecular Quantification To Extract And Monitor Antibiotic Resistance Genes In Water Samples, Amani Jereb, Celestene Adrianne Sebag, Asmaa Sadoon, Diksha Shrestha, Mary Savin, Wen Zhang, Yong Wang

Physics Faculty Publications and Presentations

Antibiotic resistance of harmful microorganisms is recognized as a serious threat to human and animal health, which is worsened by the dissemination of antibiotic resistance genes (ARGs). However, it remains challenging to identify ARGs in water samples and to distinguish intracellular (iARGs) and extracellular ARGs (eARGs). In this work, we present a feasibility study to use simple, practical methodologies to extract and distinguish ARGs in water samples using both filtration and centrifugation, followed by quantification using qPCR. Using both synthetic water samples and lake water samples, we demonstrated that the workflow reliably detected and quantified ARGs in synthetic samples. In …

Phase Equilibria Modeling Constraints On Channel Flow Of Metasedimentary Crust Beneath The Southeastern Tibetan Plateau, Govind Joshi, Gregory Dumond

Geosciences Faculty Publications and Presentations

Lower crust of the southeastern Tibetan Plateau includes 100 s of km2-scale zones of low resistivity at 20-40 km-depths indicating the presence of melt +/- fluid +/- graphite. These zones coincide with interconnected zones of low shear wave velocity. Data from central and southeastern Tibet support the occurrence of meta-sedimentary felsic granulites in the lower crust along a backarc-like geothermal gradient. Phase equilibria modeling of average metasedimentary pelite and greywacke bulk compositions constrained by these geophysical data explored the impact of partial melting on shear wave velocity for a range of fluid content. Low shear wave velocities beneath southeastern Tibet …

Season-Long Time-Series Analysis Of Soil Respiration In Furrow-Irrigated Corn With And Without Cover Crop In The Lower Mississippi River Basin, Diego Della Lunga, Kristofor Brye, Michael J. Mulvaney, Mike Daniels, Tabata De Oliveira, Beth Baker, Timothy Bradford, Chandler Arel

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Temporal resolution of carbon dioxide (CO2) release from the soil at the field scale is not completely understood. The objectives of this study were to identify trends, repetitive cycles, and residual patterns and structures with a time-series analysis from a furrow-irrigated corn (Zea mays L.) field with and without cover crops (i.e., CC and No-CC, respectively) over the course of one growing season in the Lower Mississippi River Basin. Carbon dioxide fluxes were measured from 5 May to 18 August 2024, four times a day (i.e., 0300, 0900, 1500, and 2100 h) from each of the two CC treatments. Linear …

An Integrated Ca–Markov Modeling Framework For Forecasting Land Use And Land Cover Dynamics In Arkansas, Usa, Rasool Vahid, Mohamed H. Aly

Environmental Dynamics Faculty Publications and Presentations

Land use and land cover (LULC) changes significantly shape urban environments and directly impact ecological and socioeconomic systems. This study aims to explore these interconnections by employing the Cellular Automata–Markov (CA–Markov) model to assess and predict LULC dynamics in Arkansas. Historical LULC datasets from 2001 to 2021, obtained from the National Land Cover Database, were simplified from 11 into 5 classes to facilitate analysis and effectively map transitions. The model was validated by predicting LULC for 2016 and 2021 and comparing the predictions with the real maps, achieving an overall accuracy of approximately 91.9%, using model validation metrics, including precision, …

Nanofiber-Enabled Rapid And Non-Destructive Sensors For Meat Quality And Shelf-Life Monitoring: A Review, Karna Ramachandraiah, Elizabeth M. Martin, Alya Limayem

Food Science Faculty Publications and Presentations

The meat industry faces significant economic losses and environmental impacts due to spoilage and waste, much of which results from inadequate, delayed, or inefficient quality assessment. Traditional methods used for assessing meat quality are often time-consuming, labor-intensive, and lack the ability to provide real-time information, making them insufficient for modern supply chains that demand safety, freshness, and minimal waste. Recent advances in nanotechnology position nanofibers (NFs) as promising materials for addressing these challenges through smart sensing and active packaging. NFs, characterized by their high surface-to-volume ratio, tunable porosity, and small diameter, enable superior encapsulation and immobilization of sensing agents. These …

Multiplexed Integrin Detection And Cancer Cell Classification Using Multicolor Gap-Enhanced Gold Nanorods And Machine Learning Algorithm, Suprava Shah, Reed Youngerman, Alberto Luis Rodriguez-Nieves, Mitchell Lee Taylor, William Rodney Bantom, David Thompson, Jingyi Chen, Yongmei Wang, Xiaohua Huang

Chemistry & Biochemistry Faculty Publications and Presentations

Integrins, cell-surface adhesion receptors involved in tumor progression, invasion, and metastasis, serve as crucial biomarkers for cancer diagnosis and therapeutic targeting. Multiplexed detection of integrins and cancer cell classification at the single-cell level allows for comprehensive profiling, facilitating precise identification and categorization of tumor cells that are heterogeneous in integrin expression and cell subtype. In this study, we developed a five-plex detection platform and demonstrated integrin profile for cancer cell classification leveraging surface-enhanced Raman scattering (SERS) with gap-enhanced gold nanorods (GENRs) in conjunction with advanced computational analysis. Specifically, we synthesized GENRs bearing five distinct Raman nanotags, each producing a unique …

A Revised Chronostratigraphy Of The Triassic-Jurassic Moenave Formation, Western Usa: Implications For Timing Of Continental Climate Change, Celina A. Suarez, Glenn R. Sharman, Jordan Oefinger, Asher Rea Boudreaux, Dennis Mmasa, James L. Crowley, Michael T. Mohr, Adam D. Marsh, Andrew R.C. Milner, Lisa E. Park Boush

Geosciences Faculty Publications and Presentations

The Moenave Formation of the Colorado Plateau region of western USA preserves the Triassic-Jurassic transition, a time period that saw one of the most significant climate disruptions in Earth's history. During this time, major carbon (C)-cycle perturbations due to carbon release from the emplacement of the Central Atlantic Magmatic Province (CAMP) caused rapid climate change prompting the end-Triassic mass extinction (ETE). Here we present a Bayesian agemodel generated from new C-isotope chemostratigraphic records paired with highprecision detrital zircon U-Pb geochronology to constrain the stratigraphic placement of the ETE and Triassic-Jurassic boundary within the Moenave Formation. Maximum depositional ages of detrital …

Use Of Growing Degree Days To Model The Dynamics Of Aboveground Biomass And Nitrogen Accumulation Of Winter Cover Crops, M. Pessotto, Trenton Roberts, C. Dos Santos, K. A. Hoegenauer, M. Bertucci, W. J. Ross, M. Savin

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Cover cropping is an important management practice that can benefit the cash crop and the environment. Plant species, weather, and cover crop termination influence biomass production and N fixation potential. This study was conducted to determine optimal termination dates for production systems in Arkansas based on growing degree days (GDD) for eight different cover crop species: Austrian winter pea (AWP) (Pisum sativum), balansa clover (Trifolium michelianum), barley (Hordeum vulgare), black-seeded oats (Avena sativa), common vetch (Vicia sativa var. Cahaba), cereal rye (Secale cereale), crimson clover (Trifolium incarnatum), and hairy vetch (Vicia villosa). Field studies were conducted at three research stations …

Geometry And Analysis Of The Grusin Operator, Gustavo Hoepfner, Andrew Raich

Mathematical Sciences Faculty Publications and Presentations

In this paper we introduce a new technique for analyzing the heat kernel associated to the Grusin Laplacian. We prove pointwise estimates for arbitrary derivatives of the Grusin heat kernel and the resolvent in terms of the control distance associated with the Grusin operator. Our technique is based on the globalL(1)-Gevrey method.

Shinydegsem: An Interactive Application For Pathway Perturbation Analysis In Gene Expression Studies Via Structural Equation Modeling, Zhehan Jiang, Jihong Zhang, Yuanfang Liu, Jinying Ouyang, Linlin Sun, Hao Guo

Counseling, Leadership, and Research Methods Faculty Publications and Presentations

Background Researchers in biology and bioinformatics are increasingly interested in unraveling the complex mechanisms underlying phenotypic variations. A key challenge lies in identifying perturbed biological pathways and understanding how these perturbations propagate through intricate gene regulatory networks. Results To address this challenge, we developed ShinyDegSEM, an interactive R Shiny application that leverages structural equation modeling (SEM) to facilitate pathway perturbation analysis in gene expression studies. ShinyDegSEM streamlines identifying differentially expressed genes (DEGs), generating pathway models based on biological knowledge, and evaluating these models to uncover perturbed pathway modules. This article is a tutorial to guide users through the analysis workflow, …

Geogenie: A Deep Learning Approach To Predict Geographic Provenance Of Biodiversity Samples From Genomic Snps, Bradley T. Martin, Zachery D. Zbinden, Michael E. Douglas, Marlis R. Douglas, Tyler K. Chafin

Biological Sciences Faculty Publications and Presentations

Motivation

Determining geographic origin of samples is a common objective in wildlife management, forensics, and conservation. Current methods often assume evolutionary models or require extensive reference datasets, which are costly and difficult to develop, that perform poorly with uneven or biased sampling. Supervised deep learning offers a promising alternative by learning complex patterns without prior model specifications. Combined with novel geo-genetic data augmentation and preprocessing techniques, it can reduce reference panel demands and improve performance across diverse sampling schemes, broadening accurate provenance determination to more study systems. Results

We present GeoGenIE, an open-source software package powered by PyTorch for geographic …

Chemistry And Biochemistry Affiliated Publications: Snapshot Of The Research Publications 2019-2024., Jeremy J. Smith, Lutishoor Salisbury

University Libraries Faculty Publications and Presentations

This report highlights the chemistry and biochemistry faculty publications for the period 2019-2024. It includes tables identifying the types of publications, the characteristics of the authors, inter-departmental and external cooperation, summary of the citations of the publications, and the JCR ranking of the journals in which they published.

Ge0.95sn0.05 On Si Avalanche Photodiode With Spectral Response Cutoff At 2.14 Μm, Justin Michael Rudie, Xiaoxin Wang, Rajesh Kumar, Grey Abernathy, Sylvester Amoah, Steven Akwabli, Hryhorii Stanchu, Perry C. Grant, Bao-Hua Li, Wei Du, Jifeng Liu, Shui-Qing Yu

Electrical Engineering and Computer Science Faculty Publications and Presentations

GeSn-based avalanche photodiode operating in shortwave infrared wavelength was demonstrated in this work. A separate absorption and charge multiplication structure was employed to take advantage of long wavelength absorption in GeSn and low impact ionization ratio of Si. Due to lattice mismatch between Si and GeSn that would degrade GeSn material quality if with direct growth, a 240-nm-thick Ge buffer was utilized, which simultaneously allows for the transporting photo generated electrons from the GeSn absorber to Si multiplication layer. Spectral response showed the cutoff wavelength beyond 2.1 mu m at room temperature. Dark current and capacitance-voltage measurements indicated a punch-through …

Insect-Foundation: A Foundation Model And Large Multimodal Dataset For Vision-Language Insect Understanding, Thanh-Dat Truong, Hoang-Quan Nguyen, Xuan-Bac Nguyen, Ashley Dowling, Xin Li, Khoa Luu

Electrical Engineering and Computer Science Faculty Publications and Presentations

Multimodal conversational generative AI has shown impressive capabilities in various vision and language understanding through learning massive text-image data. However, current conversational models still lack knowledge about visual insects since they are often trained on the general knowledge of vision-language data. Meanwhile, understanding insects is a fundamental problem in precision agriculture, helping to promote sustainable development in agriculture. Therefore, this paper proposes a novel multimodal conversational model, Insect-LLaVA, to promote visual understanding in insect-domain knowledge. In particular, we first introduce a new large-scale Multimodal Insect Dataset with Visual Insect Instruction Data that enables the capability of learning the multimodal foundation …

The International Perception Of The Irish Republican Army And Chechen Insurgency, Henry Forteith

The Ozark Historical Review

The purpose of this article is to explain how acts of violence influenced the media’s description of the Irish Republican Army and Chechen insurgencies and how the label of ‘terrorist’ affected the perception of the Anglo-Irish and Russo-Chechen conflicts. Quantitative data from the New York Times and International Newsstream databases are used to examine the change in word frequency to describe the IRA and Chechen fighters across a twelve-year span and four-month span before and after certain international events.

The Paper Brigade Of Vilna, Maeghan O'Conner

The Ozark Historical Review

For the Jewish community in Europe, threats to their life, culture, and community had become a real burden, even before Nazi-occupation. An ever marginalized and terrorized lot, efforts to collect Yiddish history and literature had not been particularly successful. That is why the presence of the Libraries and Archives in the "Jerusalem of Lithuania," or Vilna, which had made efforts to preserve and research Yiddish culture, was so important and why their fall in 1940 was so devastating. This work looks at the actions of everyone involved, from the fearless smuggling of the Paper Brigade to efforts to collectivize and …