Physical Sciences and Mathematics Commons^™

Distinct Composition-Dependent Topological Hall Effect In Mn2-Xznxsb, Md Rafique Un Nabi, Yue Li, Suzanne G.E. Te Velthuis, Santosh Karki Chhetri, Dinesh Upreti, Rabindra Basnet, Gokul Acharya, Charudatta Phatak, Jin Hu

Physics Faculty Publications and Presentations

Spintronics, an evolving interdisciplinary field at the intersection of magnetism and electronics, explores innovative applications of electron charge and spin properties for advanced electronic devices. The topological Hall effect (THE), a key component in spintronics, has gained significance due to emerging theories surrounding noncoplanar chiral spin textures. This study focuses on Mn_2-xZn_xSb, a material crystalizing in centrosymmetric space group with rich magnetic phases tunable by Zn contents. Through comprehensive magnetic and transport characterizations, we found that the high-Zn (x > 0.6) samples display THE which is enhanced with decreasing temperature, while THE in the low-Zn ( …

Reconfigurable Photonic Lattices Based On Atomic Coherence, Jiaqi Yuan, Shun Liang, Qingsong Yu, Chiangbao Li, Yanpeng Zhang, Min Xiao, Zhaoyang Zhang

Physics Faculty Publications and Presentations

The array of coupled optical waveguides, which is also viewed as a photonic lattice, can exhibit abundant photonic band structures depending on the desired spatial arrangements of involved waveguides. Studies of photonic lattices are usually performed in solid-state materials, where the required periodic susceptibilities can be achieved by employing the femtosecond laser direct-writing or optical induction method, and have spawned flourishing achievements in manipulating the behaviors of light. Recently, the concept of electromagnetically induced photonic lattice (EIPL) is proposed under the well-known electromagnetically induced transparency (EIT) in coherently prepared multilevel alkali-metal atomic systems, where the strong coupling beams producing EIT …

An Examination Of Academic Library Platforms And Systems During Covid-19, Cole Hudson, Paul Gallagher

University Libraries Faculty Publications and Presentations

This paper examines the use and subsequent trajectory of academic library technologies due to the impact of the COVID-19 pandemic. Taking a broad view of technologies, the systems and services discussed will center around resource use because COVID restrictions shuttered many in-person technologies. The two academic libraries compared in this study show a similar pattern of use and signal growth of certain platforms and technologies for the future.

Land Cover Effects On Stream Water Chemistry In The Upper Saline River Watershed, Brandy Everett

Graduate Theses and Dissertations

Non-point source (NPS) pollutants and the conversion of natural areas to anthropogenic uses are one of the most critical stressors on water quality. The Upper Saline River Watershed has seen an increase in anthropogenic land cover over the last two decades, leading it to be previously identified as a 319 NPS priority watershed in Arkansas. This study used publicly available data to assess the magnitude and trends of total nutrients (TN and TP) at both the watershed and site level scale. Results suggest a decrease of 2.6%/yr in TN concentrations and 1.5%/yr in TP concentrations at the watershed scale. While …

Graphene-Based Antennas Utilizing Polyvinylidene Fluoride (Pvdf) Substrates For Attenuation, Josef Frankhouse

Mechanical Engineering Undergraduate Honors Theses

In this study, a Terahertz (THz) band antenna which can regulate its own resonant frequency without the requirement of manual adjustment is simulated. A polyvinylidene fluoride (PVDF) substrate is applied onto a rectangular graphene patch antenna. With a voltage potential applied onto the PVDF, the patch antenna can attenuate its frequency by physically changing the shape of the antenna, and in turn its resonant frequency. These antennas are within a 0.1 THz band between 1.32 THz to 1.22 THz measured from a radial bend of a flat surface to r = 75 , fitting into a return loss (S_{11 …}

Reducing Token Redundancy In Video-Language Models Via Memory Consolidation Algorithm, Matt Couts

Electrical Engineering and Computer Science Undergraduate Honors Theses

Video Question Answering (VideoQA) focuses on developing mod- els capable of engaging in natural language conversations about video con- tent. Current state-of-the-art typically analyze videos frame-by-frame, a process that is both computationally and memory-intensive. Integrating the Atkinson-Shiffrin memory model with Video Language Models has demon- strated potential for enhancing video understanding capabilities. Reducing the number of frames processed by the model is a crucial operation in this approach, which is achieved by a memory consolidation algorithm. This al- gorithm condenses a video sequence into a small set of representative frames which capture the essence of the video content. However, due …

Quantum Visual Feature Encoding Revisited, Xuan-Bac Nguyen, Hoang-Quan Nguyen, Hugh Churchill, Samee U. Khan, Khoa Luu

Computer Science and Computer Engineering Faculty Publications and Presentations

Although quantum machine learning has been introduced for a while, its applications in computer vision are still limited. This paper, therefore, revisits the quantum visual encoding strategies, the initial step in quantum machine learning. Investigating the root cause, we uncover that the existing quantum encoding design fails to ensure information preservation of the visual features after the encoding process, thus complicating the learning process of the quantum machine learning models. In particular, the problem, termed the “Quantum Information Gap” (QIG), leads to an information gap between classical and corresponding quantum features. We provide theoretical proof and practical examples with visualization …

An Analysis Of Policies, Practices, And Barriers To Create A Multi-Dimensional Approach To Renewable Energy Transition For Us Communities, Hanan Wehbi

Graduate Theses and Dissertations

The transition from fossil fuel-derived energy resources to clean, renewable, affordable, and reliable energy necessitates a comprehensive approach. This approach must incorporate an interdisciplinary contribution to ensure the sustainability, efficiency, and resilience of the energy system. In the United States, many communities and local governments are developing ambitious plans, regulations, and targets to support the renewable energy transition and enhance energy efficiency. This research builds on the principles of sustainable development planning and transition theory to develop a framework that assists communities in planning their renewable energy (RE) transition and integrate these plans in their long- and short-term development approaches. …

Citizens’ Perceptions Of Wetlands Before And During The Restoration Of A Local Wetland, Delaney Ringgold

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

This study investigates the impact of a wetland restoration project on homeowners' perceptions and knowledge of wetlands in a residential area in Fayetteville, Arkansas. The research employs a pre- and during-restoration survey methodology to assess shifts in public perception and awareness of wetland environments. As part of the restoration project, native vegetation was reintroduced, and non-native species were removed, with the goals of ecological enhancement and improving the visual appeal of the wetland area. Surveys, consisting of Likert-scale questions and open-ended responses, were administered to homeowners before and during the restoration process to capture changes in demographic factors, wetland knowledge, …

Analyzing Food Sources And Food Insecurity Of Kichwa Farming Families In The Ecuadorian Amazon, Reina Watanabe

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

While the right to food is internationally recognized and the United Nations established the sustainable development goal to end hunger and achieve food security by 2030, many households remain without consistent access to food in 2024. In Latin America, approximately 4 in 10 households were reported as food insecure in 2020 with higher rates in rural and indigenous communities. Rural areas, which have great overlap with indigenous communities in Ecuador, experience disproportionately high levels of poverty and food insecurity compared to urban areas. The most populous indigenous nationality in the Ecuadorian Amazon and the participants of this study are the …

The Elusive Nature Of Martian Liquid Brines, Vincent F. Chevrier, Rachel A. Slank

Space and Planetary Science Faculty Publications and Presentations

The possible presence of brines on Mars adds an intriguing dimension to the exploration of Martian environments. Their potential involvement in the formation of recurring slope lineae has sparked debates on the existence of liquid water versus alternative dry processes. In situ instrumentation on rovers and landers has been instrumental in providing valuable data for comprehending the dynamics of brines. Laboratory experiments and thermodynamic simulations conducted under Martian conditions offer insights into the formation and persistence of brines, shedding light on the planet’s current hydrological processes. Despite these findings, the prevailing surface conditions on Mars, characterized by a combination of …

Design And Fabrication Of Graphene Solar Cells For Low-Power Energy Harvesting Systems, Tamzeed Bani Amin

Graduate Theses and Dissertations

This study presents the design and fabrication of graphene-based Schottky junction solar cells integrated into a 3-volt power system for low-power applications. Utilizing standard semiconductor processing methods, including selective oxide removal, metal contact deposition, and large-area graphene transfer, we fabricated solar cells from a silicon wafer coated with a thermal oxide layer. Each individual solar cell generated up to 270 µA of short-circuit current and an open-circuit voltage of 420 mV under illumination. We connected multiple solar cells in series to produce a total output of 3.3 volts, which is sufficient to recharge a 3-volt battery. The system, comprising these …

Evaluation Of Industrial Hemp Cultivar And Biochar Rate To Remediate Heavy-Metal-Contaminated Soil From The Tar Creek Superfund Site, Usa, Dietrich V. Thurston, Kristofor R. Brye, David M. Miller, Philip A. Moore Jr., Donald M. Johnson, Mike Richardson

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Soil contamination by cadmium (Cd), lead (Pb), and zinc (Zn) at the Tar Creek superfund site in northeast Oklahoma, United States, remains a threat to the environment and local ecosystem. Phytoremediation with industrial hemp (Cannabis sativa L.) and the use of biochar (BC) have been independently shown to be effective methods to remediate heavy-metal-contaminated soils. The objective of this greenhouse study was to evaluate the effects of industrial hemp cultivar (‘Carmagnola’ and ‘Jinma’), biochar rate (0, 2, 5, and 10% by volume), soil contamination level (low, medium, and high), and their interactions on above- (AG) and belowground dry matter …

Rice Response To Struvite And Other Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye, Diego Della Lunga, Kristofor R. Brye

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Wastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH₄PO₄⋅6H₂O), may provide a sustainable alternative to decreasing rock-phosphate reserves. Struvite can be generated via precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice (Oryza sativa) cultivar grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)]. Rice was …

Array Of Graphene Solar Cells On 100 Mm Silicon Wafers For Power Systems, Syed M. Rahman, Md R. Kabir, Tamzeed B. Amin, James M. Mangum, Ashaduzzaman, Paul M. Thibado

Physics Faculty Publications and Presentations

High electrical conductivity and optical transparency make graphene a suitable candidate for photovoltaic-based power systems. In this study, we present the design and fabrication of an array of graphene-based Schottky junction solar cells. Using mainstream semiconductor manufacturing methods, we produced 96 solar cells from a single 100 mm diameter silicon wafer that was precoated with an oxide layer. The fabrication process involves removing the oxide layer over a select region, depositing metal contacts on both the oxide and bare silicon regions, and transferring large-area graphene onto the exposed silicon to create the photovoltaic interface. A single solar cell can provide …

An Empirical Framework Characterizing The Metallicity And Star-Formation History Dependence Of X-Ray Binary Population Formation And Emission In Galaxies, Bret D. Lehmer, Erik B. Monson, Rafael T. Eufrasio, Amirnezam Amiri, Keith Doore, Antara Basu-Zych, Kristen Garofali, Lidia Oskinova, Jeff J. Andrews, Vallia Antoniou, Robel Geda, Jenny E. Greene, Konstantinos Kovlakas, Margaret Lazzarini, Chris T. Richardson

Physics Faculty Publications and Presentations

We present a new empirical framework modeling the metallicity and star formation history (SFH) dependence of X-ray luminous (L ≳ 10³⁶ erg s⁻¹) point-source population X-ray luminosity functions (XLFs) in normal galaxies. We expect that the X-ray point-source populations are dominated by X-ray binaries (XRBs), with contributions from supernova remnants near the low luminosity end of our observations. Our framework is calibrated using the collective statistical power of 3731 X-ray detected point sources within 88 Chandra-observed galaxies at D ≲ 40 Mpc that span broad ranges of metallicity (Z ≈ 0.03–2 Z_⊙), SFH, …

Neural Network Architecture Search Enabled Wide-Deep Learning (Nas-Wd) For Spatially Heterogenous Property Awared Chicken Woody Breast Classification And Hardness Regression, Chaitanya Pallerla, Yihong Feng, Casey M. Owens, Ramesh Bahadur Bist, Siavash Mahmoudi, Pouya Sohrabipour, Amirreza Davar, Dongyi Wang

Poultry Science Faculty Publications and Presentations

Due to intensive genetic selection for rapid growth rates and high broiler yields in recent years, the global poultry industry has faced a challenging problem in the form of woody breast (WB) conditions. This condition has caused significant economic losses as high as $200 million annually, and the root cause of WB has yet to be identified. Human palpation is the most common method of distinguishing a WB from others. However, this method is time-consuming and subjective. Hyperspectral imaging (HSI) combined with machine learning algorithms can evaluate the WB conditions of fillets in a non-invasive, objective, and high-throughput manner. In …

A Near-Wall Methodology For Large-Eddy Simulation Based On Dynamic Hybrid Rans-Les, Michael Tullis, D. Keith Walters

Mechanical Engineering Faculty Publications and Presentations

Attempts to mitigate the computational cost of fully resolved large-eddy simulation (LES) in the near-wall region include both the hybrid Reynolds-averaged Navier–Stokes/LES (HRL) and wall-modeled LES (WMLES) approaches. This paper presents an LES wall treatment method that combines key attributes of the two, in which the boundary layer mesh is sized in the streamwise and spanwise directions comparable to WMLES, and the wall-normal mesh is comparable to a RANS simulation without wall functions. A mixing length model is used to prescribe an eddy viscosity in the near-wall region, with the mixing length scale limited based on local mesh size. The …

Clusteredlog: Optimizing Log Structures For Efficient Data Recovery And Integrity Management In Database Systems, Mariha Siddika Ahmad, Brajendra Panda

Electrical Engineering and Computer Science Faculty Publications and Presentations

In modern database systems, efficient log management is crucial for ensuring data integrity and facilitating swift recovery from potential data corruption or system failures. Traditional log structures, which store operations sequentially as they occur, often lead to significant delays in accessing and recovering specific data objects due to their scattered nature across the log. ClusteredLog addresses the limitations of traditional logging methods by implementing a novel logical organization of log entries. Instead of simply storing operations sequentially, it groups related operations for each data item into clusters. As a result, ClusteredLog enables faster identification and recovery of damaged data items …

Universal Shape Replication Via Self-Assembly With Signal-Passing Tiles, Andrew Alseth, Daniel Hader, Matthew J. Patitz

Computer Science and Computer Engineering Faculty Publications and Presentations

In this paper, we investigate shape-assembling power of a tile-based model of self-assembly called the Signal-Passing Tile Assembly Model (STAM). In this model, the glues that bind tiles together can be turned on and off by the binding actions of other glues via “signals”. Specifically, the problem we investigate is “shape replication” wherein, given a set of input assemblies of arbitrary shape, a system must construct an arbitrary number of assemblies with the same shapes and, with the exception of size-bounded junk assemblies that result from the process, no others. We provide the first fully universal shape replication result, namely …

Comparison Of Statistical And Machine Learning Genomic Prediction Methods In Plant Breeding: Case Studies In Maize And Soybean, Igor Kuivjogi Fernandes

Graduate Theses and Dissertations

Plant breeding is essential to increase genetic gain and food production worldwide. This study was conducted to evaluate new ways to use machine learning (ML) to tackle plant breeding challenges, where two ideas were tested — the first chapter focuses on how to combine genetic and environmental data using ML to improve the prediction of maize grain yield in multi-environment trials, while the second chapter centers on how to couple feature selection of molecular markers with ML to enhance prediction of yield in soybean, and, in both cases, ML approaches were compared to well-established statistical methods greatly adopted by the …

Towards Robust And Fair Vision Learning In Open-World Environments, Thanh-Dat Truong

Graduate Theses and Dissertations

The rapid increase of large-scale data and high-performance computational hardware has promoted the development of data-driven machine vision approaches. Advanced deep learning approaches have achieved remarkable performance in various vision problems and are closing the capability gap between artificial intelligence (AI) and humans. However, towards the ultimate goal of AI, which replicates human ability in visual perception tasks, the machine vision learning methods still need to address several ill-posed challenges. First, while the current vision learning methods often rely on large-scale annotated data, the data annotation process is a costly and time-consuming process. Second, the unfaired predictions produced by vision …

Neural Network Architecture Search Enabled Wide-Deep Learning (Nas-Wd) Integrated Hyperspectral Imaging Understanding For Woody Breast In Poultry Processing, Chaitanya Kumar Reddy Pallerla

Graduate Theses and Dissertations

The development and implementation of a Wide & Deep (WD) learning model tailored for classification and regression tasks utilizing spectral data provides a robust solution to evaluate woody breast (WB) conditions in poultry fillets. This process begins with thorough data preprocessing, which includes loading spectral and classification datasets, imputing missing values with medians, and splitting the data into training and testing sets to ensure rigorous model evaluation. The WD model architecture integrates wide linear models and deep neural networks to harness the strengths of both approaches. The wide component excels at memorizing sparse feature interactions, while the deep component captures …

The Impact Of Wild Pigs (Sus Scrofa) On Avian Occupancy And Vegetation Structure, Kenneth Wilson

Graduate Theses and Dissertations

Invasive species, particularly wild pigs (Sus scrofa), pose a significant threat to native ecosystems through both direct and indirect impacts. Wild pigs are large-bodied omnivorous species that can consume a wide variety of plants and animals and are known for destructive foraging behaviors, which likely threatens avian communities through habitat alteration and can impact the long term structure of ecosystems where they are present.

In chapter 1, we used a combination of avian point count surveys, vegetation assessments, and camera trap surveillance to quantify how the occupancy of breeding birds in bottomland hardwood forests changed in relation to …

Traittrainr: Accelerating Large-Scale Simulation Under Models Of Continuous Trait Evolution, Jenniffer Roa Lozano, Mataya Duncan, Duane D. Mckenna, Todd A. Castoe, Michael Degiorgio, Richard Adams

Entomology and Plant Pathology Faculty Publications and Presentations

Abstract

The scale and scope of comparative trait data are expanding at unprecedented rates, and recent advances in evolutionary modeling and simulation sometimes struggle to match this pace. Well-organized and flexible applications for conducting large-scale simulations of evolution hold promise in this context for understanding models and more so our ability to confidently estimate them with real trait data sampled from nature. Results

We introduce TraitTrainR, an R package designed to facilitate efficient, large-scale simulations under complex models of continuous trait evolution. TraitTrainR employs several output formats, supports popular trait data transformations, accommodates multi-trait evolution, and exhibits flexibility …

Decoding Fgf/Fgfr Signaling: Insights Into Biological Functions And Disease Relevance, Oshadi Edirisinghe, Gaetane Ternier, Zeina Alraawi, Thallapuranam Krishnaswamy Suresh Kumar

Chemistry & Biochemistry Faculty Publications and Presentations

Fibroblast Growth Factors (FGFs) and their cognate receptors, FGFRs, play pivotal roles in a plethora of biological processes, including cell proliferation, differentiation, tissue repair, and metabolic homeostasis. This review provides a comprehensive overview of FGF-FGFR signaling pathways while highlighting their complex regulatory mechanisms and interconnections with other signaling networks. Further, we briefly discuss the FGFs involvement in developmental, metabolic, and housekeeping functions. By complementing current knowledge and emerging research, this review aims to enhance the understanding of FGF-FGFR-mediated signaling and its implications for health and disease, which will be crucial for therapeutic development against FGF-related pathological conditions.

Cellulose–Starch Composite Aerogels As Thermal Superinsulating Materials, Safoura Ahmadzadeh, Angelina Sagardui, David Huitink, Jingyi Chen, Ali Ubeyitogullari

Chemistry & Biochemistry Faculty Publications and Presentations

The demand for sustainable packaging materials is rapidly increasing due to growing environmental concerns over the impact of plastic waste. In this study, biodegradable, porous, lightweight, and high-surface-area microcrystalline cellulose–starch (MCC-S) hybrid aerogels were synthesized via supercritical carbon dioxide (SC–CO₂) drying. The samples were generated using five different MCC-S weight ratios and characterized for their morphology, crystallinity, and structural and thermal properties. When MCC and S were used together, aerogels with superior properties were obtained compared to those made from each component individually. Specifically, the 1:2 MCC-S aerogel exhibited the highest porosity (97%), the lowest density (0.058 g/cm …

Jürgen Habermas Revisited Via Tim Cook's Wikipedia Biography: A Hermeneutic Approach To Critical Information Systems Research, Reilly Smethurst, Amber G. Young, Arial D. Wigdor

Information Systems Faculty Publications and Presentations

Critical Information Systems (IS) research is sometimes appreciated for the shades of gray it adds to sunny portraits of technology's emancipatory potential. In this article, we revisit a theory about Wikipedia’s putative freedom from the authority of corporate media's editors and authors. We present the curious example of Tim Cook's Wikipedia biography and its history of crowd-sourced editorial decisions, published on Wikipedia's talk pages. We use a hermeneutic method to subject the theory about Wikipedia's “rational discourse” and “emancipatory potential” to a soft, empirical test. When we examined Cook's Wikipedia biography and its editorial decisions, what we found pertained to …

United We Stand, Divided We Fall: An Autogenic Perspective On Empowering Cybersecurity In Organizations, Alexandra Durcikova, Shayla M. Miranda, Matthew L. Jensen, Ryan T. Wright

Information Systems Faculty Publications and Presentations

Cybersecurity groups navigate complex, challenging environments in their mission to protect their organizations. They experience uncertainty from adaptive threats from external attackers and unpredictable stakeholders. Under such volatility, business groups operate best when they are psychologically empowered. Recognizing the potential for empowerment to reduce organizational risk, we sought to learn how cybersecurity groups come to be (dis)empowered and how this (dis)empowerment is sustained. Instead of the conventional view of the empowerment process as designed, we advance an emergent view of the empowerment process. We abductively surface this process from our case analyses of 15 U.S. organizations. We offer three insights: …

Medium-Entropy Engineering Of Magnetism In Layered Antiferromagnet CuXNi2(1-X)CrXP2S6, Dinesh Upreti, Rabindra Basnet, M. M. Sharma, Santosh Karki Chhetri, Gokul Acharya, Md Rafique Un Nabi, Joshua Sakon, Mourad Benamara, Mansour Mortazavi, Jin Hu

Physics Faculty Publications and Presentations

Antiferromagnetic van der Waals-type M₂P₂X₆ compounds provide a versatile material platform for studying 2D magnetism and relevant phenomena. Establishing ferromagnetism in 2D materials is technologically valuable. Though magnetism is generally tunable via a chemical way, it is challenging to induce ferromagnetism with isovalent chalcogen and bimetallic substitutions in M₂P₂X₆. Here, we report co-substitution of Cu¹⁺ and Cr³⁺ for Ni²⁺ in Ni₂P₂S₆, creating Cu_xNi_2(1-x)Cr_xP₂S₆ medium-entropy alloys spanning a full substitution range ( …