Digital Commons Network^™

Computational Studies Of Charge-Transfer Mechanisms In Electrochemical Materials, Mohammadreza Reza Nouri

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Understanding charge transfer mechanisms of electrochemical reactions is critical for advancing a variety of electrochemical energy storage and conversion technologies such as water electrolysis, fuel cells, and batteries. (Photo)electrochemical water splitting, involving OER at the anode and HER at the cathode, presents an environmentally friendly way of storing energy from renewable sources in the form of pure hydrogen. While a lot of emphasis has been placed on developing highly active and stable OER/HER catalysts, our atomic-level understanding of the underlying charge transfer mechanisms falls behind.

In this work, we focus on both Faradaic and non-Faradaic charge transfer mechanisms to investigate …

Integration Of Matlab And Machine Learning To Accelerate Evaluation Of Biological Activity In Agricultural Soils And Promote Soil Health Improvement Goals, Andrew Stiven Ortiz Balsero

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Traditionally, assessments of soil biological activity have been confined to laboratory settings, creating a disconnect with practical in-field methods. To bridge this gap, cotton fabric degradation has been used to illustrate soil microbial activity under different management practices. While effective, these demonstrations are subjective and labor-intensive.

Researchers have explored using image processing software like ImageJ and Adobe Photoshop to streamline this process. Although these tools accurately quantified fabric degradation under varying soil conditions, the methods remained labor-intensive and complex. Consequently, these methods were still not ideal for on-farm use by agricultural practitioners.

To further address labor and complexity limitations, the …

Emergent Phenomena In Ferroelectric-Dielectric And Ferroelectric-Graphene Heterostructures, Tianlin Li

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation explores the emergent phenomena in epitaxial ferroelectric oxide-based heterostructures, including the negative capacitance (NC) effect in ferroelectric-dielectric systems, ferroelectric gate imposed mobility limit in graphene field-effect transistors, and ferroelectric domain-induced graphene-superlattices.

We carry out a phenomenological study of the NC effect in PbZr_0.2Ti_0.8O₃/SrTiO₃ capacitors. The Landau free-energy profile predicts a critical thickness ratio for the ferroelectric-dielectric phase transition, consistent with the observed abrupt change in remnant polarization. A static NC state is observed in the low thickness ratio region, which is compromised by the emergence of multidomain in the moderate ratio …

We're Swarming Again! Swarming, Collectivity, And Trope: The Case Of Extinction Rebellion, Tyler J. Behymer

Department of Communication Studies: Dissertations, Theses, and Student Research

This thesis explores the rhetoric of the eco-movement Extinction Rebellion, focusing on the use of swarming and nature tropes to mobilize collective action and revivify contemporary notions of collectivity. Drawing on rhetoric of social movement scholarship, cultural studies, and psychoanalysis, this essay theorizes swarming as a tropological economy that expands the conditions of propriety in the context of collectivity. Through an analysis of Extinction Rebellion’s discourse, this study demonstrates how the naturalization of swarming tropes works in various ways to rewild conventional political discourse, galvanize disruptive collective assembly, and challenge green neoliberalism.

Advisor: Casey Ryan Kelly

Development And Validation Of Aronia Melanocarpa Berry Recipes For Home Canning: Integrating Thermal Lethality Studies, Microbiological Safety, And Antioxidant Analysis, Juan Diego Villegas Posada

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Aronia melanocarpa, also known as chokeberry, is gaining popularity for its high antioxidant content and health benefits, including reducing oxidative stress and inhibiting cancer gene expression. However, its characteristic bitterness and astringency limit its broader appeal. Chokeberry's low pH places it in the acid foods category, making it ideal for safe home canning. An acidic environment combined with heat treatment inhibits harmful bacteria like Clostridium botulinum. Home canning preserves food by sealing it in airtight containers and heating it to destroy spoilage microorganisms.

Developing safe and palatable recipes is essential for making chokeberries suitable for home canning. A …

Development Of An Egg-Specific Mass Spectrometry Targeted Method For Processed Food Matrices, Liyun Zhang

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Egg is a major food allergen in the United States, causing symptoms from mild reactions to severe anaphylaxis. An egg-free diet remains the only management approach for egg allergy. Therefore, individuals and families living with egg allergies rely heavily on allergen statements on packaged food products for informed food choices. Currently, no labeling regulations exist for unintentionally introduced allergens, posing risks to consumers with egg allergies. Therefore, it is critical to have an accurate and reliable detection method in allergen control and management to determine the concentration of total protein from allergenic food sources. Traditional enzyme-linked immunosorbent assays are routinely …

Elementary Science Teacher Self-Efficacy In The Context Of Ngss-Aligned Curriculum Enactment: An Explanatory Sequential Mixed Methods Study, Wesley P. Sliger

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

A confluence of circumstances in educational policy and teacher preparation have placed a low priority on elementary science teacher preparation. Historically, a lack of elementary science teachers’ subject matter knowledge and pedagogical knowledge has negatively impacted science teaching self-efficacy, which is linked to many teacher and student outcomes. Meanwhile, the past decade has ushered in the Next Generation Science Standards (NGSS) and the modern era of reform-based science teaching. The emergence of self-proclaimed NGSS-aligned resources has outpaced academic examination regarding professional development (PD), curriculum implementation, and curriculum enactment. The purpose of this study was to use social cognitive theory to …

Nanoparticle-Based Approaches To Brain Injury And Studies For Improved Detectability Toward Better Delivery Characterization, Hunter A. Miller

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The clinical translation of nanoparticle (NP) therapeutics for brain injury has been slow despite preclinical promise. The causes of disconnect between preclinical and clinical outcomes is multifactorial, but insufficient delivery is noteworthy. Preclinical delivery characterization often lacks, obscuring mechanisms of failure, slowing development. Multimodal imaging is a promising strategy to improve delivery characterization, combining the strengths of various modalities. Magnetic resonance imaging (MRI) and luminescence imaging are a suitable combination for multimodal imaging, expanding the spatial and temporal resolution of either alone, but further material development is needed to enhance detectability. One problem is the interference of cellular autofluorescence in …

Investigating Near-Field Radiative Heat Transfer With Titanium Carbide Mxenes And Slanted Columnar Thin Films, Sean Luke Murray

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This work investigates the mechanisms to manipulate and control the magnitudes of Near-Field Radiative Heat Transfer (NFRHT) using two-dimensional materials and nanostructured surfaces. NFRHT occurs when the geometrical features of the radiating objects or the separation distance between interacting bodies are comparable to or lower than the characteristic thermal radiation wavelength. NFRHT magnitudes surpass the blackbody limit by several orders of magnitude due to phenomena such as photon tunneling and new modes of energy transfer, like surface polaritons. Therefore, it is crucial to understand how material properties and surface nanostructures affect NFRHT.

The first part of this work examines the …

Leavers And Movers: Turnover Of Music Teachers In Nebraska, Christian G. Schuerman

Glenn Korff School of Music: Dissertations, Theses, Student Creative Work, and Performances

The purpose of this study was to determine if the rates of music teachers leaving the teaching profession and changing schools were significantly different than those of teachers of other content areas in the state of Nebraska. This study used data from the previous nine years of the Nebraska Department of Education’s Education Directory in order to find results for the entire population. Results indicated that music teachers leave the profession at similar rates as teachers of other content areas, but move schools at significantly higher rates.

Advisor: Robert H. Woody

Online Course Development With University Extension And Industry Experts, Kelsey L. Mccullough

Applied Science Program: Theses

Project Background

While pursuing my college degrees, the highest impact classes have been filled with applications that I understood as being relevant at the time and have used within my career, had hands-on experiences, and included influential interactions with professionals. Taking this idea forward to course development as an online instructor, I know that creating and adapting college classes to be centered on key aspects of the agricultural industry will add to the education quality of the program and the college experience. This paper will describe my first attempt at this model of partnering with academic and industry experts to …

Patterning Synthesis Of Lead Halide Perovskites Toward Photonic Application, S. M. Nayeem Arefin

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Lead halide perovskites (LHPs) are a fascinating class of photonic materials with the potential to revolutionize various optoelectronic applications. Their diverse crystal structures, ranging from 0D to 3D configurations, offer a unique combination of properties, including high tunability and ease of synthesis. However, their inherent instability and the difficulty of patterning them into sophisticated photonic structures using conventional methods present a significant hurdle to their widespread applications. This thesis addresses these challenges by proposing a novel synthesis method that combines soft lithography and self-assembly. By utilizing a patterned template with controlled wettability, precise manipulation of LHP crystal formation is achieved, …

Ultrashort Pulsed Laser Treatment Is Effective At Sterilizing Metal Surfaces For Planetary Protection, Kaleb Mcquillan

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

To prevent forward contamination from microbes aboard spacecraft intended for exploration of solar system bodies there is a need for effective sterilization methods. However, current techniques are both time-consuming and expensive. For example, dry heat sterilization requires removal from the assembly site and several days of treatment. Furthermore, some components such as optics and electronics are not compatible with current sterilization techniques. In this thesis, a novel femtosecond laser surface processing technique for the rapid sterilization of spacecraft hardware is reported. Femtosecond lasers produce extremely high photon fluxes (10²⁹ photons/s*cm², ~0.03 J/cm²) in extremely short …

Microbial Transfer And Cross-Contamination In Milling Facilities And Pathogen Survival In Milled Products And Baking Mixes, Aryany Leticia Peña-Gomez

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Wheat-based products, traditionally considered low-risk due to their low moisture content, have been involved in numerous foodborne outbreaks in recent decades. Salmonella and Shiga toxin-producing Escherichia coli (STEC) present in these products have caused significant numbers of hospitalizations and massive product recalls. The microbiological quality of flour is highly dependent on the incoming wheat, which is vulnerable to contamination from field to milling. Once pathogens are present in flour, they can survive for extended periods. Implementing strategies to mitigate the risk of pathogen contamination throughout the wheat processing chain is critical.

This study evaluated the distribution of E. coli …

Integrated Multi-Omics Analysis Of Cerebrospinal Fluid In Postoperative Delirium, Bridget A. Tripp, Simon T. Dillon, Min Yuan, John M. Asara, Sarinnapha M. Vasunilashorn, Tamara G. Fong, Sharon K. Inouye, Long H. Ngo, Edward R. Marcantonio, Zhongcong Xie, Towia A. Libermann, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

Preoperative risk biomarkers for delirium may aid in identifying high-risk patients and developing intervention therapies, which would minimize the health and economic burden of postoperative delirium. Previous studies have typically used single omics approaches to identify such biomarkers. Preoperative cerebrospinal fluid (CSF) from the Healthier Postoperative Recovery study of adults ≥ 63 years old undergoing elective major orthopedic surgery was used in a matched pair delirium case–no delirium control design. We performed metabolomics and lipidomics, which were combined with our previously reported proteomics results on the same samples. Differential expression, clustering, classification, and systems biology analyses were applied to individual …

Greater Aperture Counteracts Effects Of Reduced Stomatal Density On Water Use Efficiency: A Case Study On Sugarcane And Meta-Analysis, Daniel Lunn, Baskaran Kannan, Amandine Germon, Alistair Leverett, Thomas E. Clemente, Fredy Altpeter, Andrew D.B. Leakey

Department of Agronomy and Horticulture: Faculty Publications

Stomata regulate CO₂ and water vapor exchange between leaves and the atmosphere. Stomata are a target for engineering to improve crop intrinsic water use efficiency (iWUE). One example is by expressing genes that lower stomatal density (SD) and reduce stomatal conductance (g_sw). However, the quantitative relationship between reduced SD, g_sw, and the mechanisms underlying it is poorly understood. We addressed this knowledge gap using low-SD sugarcane (Saccharum spp. hybrid) as a case study alongside a meta-analysis of data from 10 species. Transgenic expression of EPIDERMAL PATTERNING FACTOR 2 from Sorghum bicolor (SbEPF2) in sugarcane …

Development And Evaluation Of An Expedited System For Creation Of Single Walled Carbon Nanotube Platforms, Ivon Acosta Ramirez, Omer Sadak, Wali Sohail, Xi Huang, Yongfeng Lu, Nicole M. Iverson

Department of Electrical and Computer Engineering: Faculty Publications

Single-walled carbon nanotubes (SWNT) have a strong and stable near-infrared (nIR) fluorescence that can be used to selectively detect target analytes, even at the single molecule level, through changes in either their fluorescence intensity or emission peak wavelength. SWNTs have been employed as NIR optical sensors for detecting a variety of analytes. However, high costs, long fabrication times, and poor distributions limit the current methods for immobilizing SWNT sensors on solid substrates. Recently, our group reported a protocol for SWNT immobilization with high fluorescence yield, longevity, fluorescence distribution, and sensor response, unfortunately this process takes 5 days to complete. Herein …

Optimized Gadolinium-Do3a Loading In Raftpolymerized Copolymers For Superior Mr Imaging Of Aging Blood–Brain Barrier, Hunter A. Miller, Aaron Priester, Evan T. Curtis, Krista Hilmas, Ashleigh Abbott, Forrest Kievit, Anthony J. Covertine

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The development of gadolinium-based contrast agents (GBCAs) has been pivotal in advancing magnetic resonance imaging (MRI), offering enhanced soft tissue contrast without ionizing radiation exposure. Despite their widespread clinical use, the need for improved GBCAs has led to innovations in ligand chemistry and polymer science. We report a novel approach using methacrylate-functionalized DO3A ligands to synthesize a series of copolymers through direct reversible addition-fragmentation chain transfer (RAFT) polymerization. This technique enables precise control over the gadolinium content within the polymers, circumventing the need for subsequent conjugation and purification steps, and facilitates the addition of other components such as targeting ligands. …

Revisiting Fr13a For Submergence Tolerance: Beyond The Sub1a Gene, Waseem Hussain, Mahender Anumalla, Abdelbagi M. Ismail, Harkamal Walia, Vistas Kumar Singh, Ajay Kohli, Sankalp Bhosale, Hans Bhardwaj

Department of Agronomy and Horticulture: Faculty Publications

Rice landrace FR13A is the original donor of the SUB1A gene. FR13A harbors hidden genetic variation that surpasses the submergence tolerance level of SUB1A. Here, we provide an overview of the unique features of FR13A associated with exceptional recovery ability that have been overlooked since the significant discovery of the SUB1 locus. We present a detailed overview of how to underpin the new genes associated with the recovery ability seen in FR13A. Finally, we propose a unique approach to develop rice cultivars that surpass submergence tolerance beyond the SUB1 locus from FR13A.

Twist-Assisted All-Antiferromagnetic Tunnel Junction In The Atomic Limit, Yullang Chen, Kartik Samanta, Naafls A. Shahed, Haojle Zhang, Chi Fang, Arthur Ernst, Evgeny Y. Tsymbal, Stuart S.P. Parkin

Nebraska Center for Materials and Nanoscience: Faculty Publications

Antiferromagnetic spintronics^1,2 shows great potential for high-density and ultrafast information devices. Magnetic tunnel junctions (MTJs), a key spintronic memory component that are typically formed from ferromagnetic materials, have seen rapid developments very recently using antiferromagnetic materials3,4. Here we demonstrate a twisting strategy for constructing all-antiferromagnetic tunnel junctions down to the atomic limit. By twisting two bilayers of CrSBr, a 2D antiferromagnet (AFM), a more than 700% nonvolatile tunnelling magnetoresistance (TMR) ratio is shown at zero field (ZF) with the entire twisted stack acting as the tunnel barrier. This is determined by twisting two CrSBr monolayers for which the TMR …

The Growth Of Ethanol In Brazil: Sugarcane, Corn, And A Few Other Things, Fabio Mattos

Cornhusker Economics

Although we can expect more ethanol produced from corn in the coming years, it is unclear whether it will keep expanding at the same pace as in recent years or how much it will contribute to total ethanol production.

One point to keep an eye on is the typical dynamics of markets. If supply and demand conditions and price movements make corn-ethanol more profitable, ethanol plants in Brazil will keep increasing their production. If it makes more economic sense to produce corn-ethanol (as it happened recently), they will use more corn to produce ethanol.

Supply and demand conditions for ethanol, …

Enhancing Water Sustainability In North Africa: Literature Review And Synthesis Of Current Knowledge Gaps In Sudan, Osman M. A. Adam, Aaron R. Mittelstet, Derek M. Heeren, Troy E. Gilmore

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

This study delves into the critical role of groundwater in addressing global water challenges, with a focus on the Nubian Sandstone Aquifer System (NSAS) in North Africa. Groundwater constitutes a source of potable water, irrigation, and industrial use, especially in arid regions where surface water is limited. We analyzed the status of water quantity, withdrawals, recharge, and geological characteristics in the NSAS, specifically in Sudan, Egypt, Libya, and Chad. Though the NSAS is largely an untapped resource, we evaluated various scenarios to determine the quantity of cropland that can be sustainably irrigated. The NSAS is located in an arid region, …

Resources In Northeast Nebraska's Waste Could Power The Future, Reese Vanosdel, Emma Kurtz, Tyler Knaak

Project Energy Nebraska: Student Projects

Environmental Engagement in the Community projects, summer 2024

A poster titled Resources in Northeast Nebraska's Waste Could Power the Future for clients City of Norfolk, Nebraska (Steven Rames) and City of Wayne, Nebraska (Wes Blecke and Sandy Brown).

Advisor: David Gosselin

Development Of A Rule-Based Monitoring System For Autonomous Heavy Equipment Safety, Amirpooya Shirazi

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Roadway construction work zones are constantly exposed to interactions among construction equipment, workers, and vehicles. Furthermore, ensuring safety in these areas is considered a challenging task due to the complexity of the environment. As shown in the rising trend of fatal accidents in roadway work zones, current OSHA regulations in construction safety are insufficient in effectively detecting unsafe situations and mitigating the risks. Furthermore, best practices, such as internal traffic control planning (ITCP), exhibit critical limitations requiring continuous monitoring of active work zones as well as adjustments to the site coordination plans due to the dynamic nature of work zone …

Unmanned Aerial Vehicle (Uav)-Based High-Throughput Phenotyping For Maize Improvement, Eric T. Rodene

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Modern breeding programs rely heavily on efficiently screening large numbers of genotypes for agronomic traits, such as disease resistance, drought tolerance, and yield. Identifying the genetic loci or genes associated with these traits using GWAS or functional analyses will benefit future plant breeding efforts seeking to incorporate these traits into new crop varieties, whether through conventional breeding or gene editing techniques. Unmanned aerial vehicle (UAV)-based image data has been increasingly used for this task, as it allows entire test plots to be quickly and cost-effectively phenotyped. In my research, I have developed methods to improve the accuracy of machine learning …

Development Of A Durable And Low-Dose Universal Vaccine Against Swine Influenza A Virus, Erika Petro-Turnquist

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Swine Influenza A Virus (IAV-S) imposes a significant burden on the pork industry and poses a great threat to public health due to its zoonotic potential. Susceptibility to human, avian, and swine influenza make pigs the ultimate mixing vessels for reassorted influenza A virus strains. Current vaccination strategies induce short-lived and strain-specific responses against IAV-S. Further, the substantial genetic diversity of IAV-S necessitates consistent revaccination and updating of commercial vaccines. Computational platforms have recently emerged as a promising strategy to develop new-age vaccines against infectious diseases in livestock animals. Here, we describe a computationally derived set of vaccine immunogens, called …

Estranged Temporality: How Time Tells Stories In Science Fiction, Phillip H. Howells

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

According to Darko Suvin in his influential critical treatise, Metamorphoses of Science Fiction, estrangement in Science Fiction (SF) gives authors the ability to build worlds related to but distant from our own using specific metaphors. This dissertation takes up this term and applies it to the fulcrum of time in SF as a method of creating possible futures and imaginative pasts in order to illuminate the realities of the present. The realities of the present are congruent with the material circumstances of the past, and this can be seen in the kinds of SF worlds built by members of …

Genetically Modified Bovine Milk-Derived Small Extracellular Vesicles In Drug Delivery, Alice Kah Hui Ngu

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Small extracellular vesicles (SEVs, “exosomes”) are natural nanoparticles that can be endogenously synthesized and also obtained from dietary sources, such as bovine milk SEVs (mEVs). mEVs have been extensively studied and discovered with contributive features that potentially play a role in drug delivery and other therapeutic purposes, such as diagnostic tools. Current studies have shown that mEVs have been used preclinically to carry in targeting drugs, nucleotides, biomolecules, and labels to target metabolic diseases and cancers. Extensive studies have focused on further modifying SEVs to enhance their versatility in pharmaceutical use. In this dissertation, we exhibited one of the ways …

Laser 3d Printing Of Diamond-Based Composite Materials For Thermal Management Applications, Nada Kraiem

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

With the trend towards miniaturization of electrical equipment and the constant increase in power density in semiconductor devices, efficient heat management has become a major concern for researchers. Indeed, this technological evolution imposes increasingly strict constraints in terms of thermal dissipation, necessitating innovative solutions to ensure better durability and reliability of components. In this context, the use of composite materials offering high thermal conductivity (TC) and low coefficient of thermal expansion (CTE) compared to pure metals has become essential to address overheating issues in electronic components.

The utilization of advanced materials such as diamond (D), with exceptional TC and hardness …

Advancements In Microscale Tensile Testing: A Novel Device For The High Throughput Analysis Of Two-Photon Polymerized Microfibers In Liquid, Grayson D. Minnick

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Two-photon polymerization (TPP) enables the 3D fabrication of micro- and nanostructures from biocompatible materials with high resolutions, reaching into the realm of hundreds of nanometers. Such capabilities are crucial for advancing applications in fields like mechanobiology. As microscale technologies evolve, the precise characterization of material properties becomes increasingly essential. This is especially true for TPP-printed microstructures serving as scaffolds for 3D cell culture and intended for studying the mechanics of tissues. Despite the importance, traditional micro-scale tensile testing methods typically lack scalability and fail to replicate relevant environmental conditions. This dissertation introduces a new device that is specifically designed to …