Digital Commons Network^™

Metabolic Responses Of Adipose-Derived Stem Cells In Collagen I Hydrogels, Caroline R. King

Biological Sciences Undergraduate Honors Theses

Peripheral nerve injury affects approximately 44 in 1 million people in the United States every year and can lead to incomplete nerve recovery and loss of motor and sensory function. A significant amount of energy is required for nerve injury repair. A lack of energy allocation to the injury site hinders repair. Current treatments include hollow nerve guidance conduits, decellularized nerve grafts, and autografts. However, they are limited by factors such as donor site morbidity and sustained immunosuppressive treatments. Using three-dimensional collagen I hydrogels laden with adipose-derived stem cells (ASCs) can assist in neural regeneration. Three-dimensional collagen scaffolds aim to …

Feasibility Of Liquid Carbon Sources For Algae Growth, Brady S. Jones

Chemical Engineering Undergraduate Honors Theses

This thesis explores the use of electrochemically produced aqueous bicarbonate as a novel liquid-phase carbon source for enhancing algal biomass productivity. Targeting the freshwater microalgae Chlorella Saccharophila, the study investigates its growth response to varying bicarbonate concentrations and compares the efficacy of liquid bicarbonate delivery with traditional gaseous CO₂ bubbling methods. Results demonstrate that Chlorella Saccharophila can sustain growth solely on bicarbonate, and that bicarbonate-fed cultures yielded higher biomass than those supplied with gaseous CO₂ or hybrid systems. These findings validate the potential of bicarbonate-based carbon delivery for scalable algae cultivation, offering key advantages such as gas-free operation, improved …

Evaluating Fly-Ash As A Sustainable Solution For Contaminant Removal From Wastewater, Calyn Wisdom

Chemical Engineering Undergraduate Honors Theses

Access to clean and safe water is an escalating global concern due to the persistent presence of toxic contaminants in aquatic environments. Among these, synthetic dyes and per- and polyfluoroalkyl substances (PFAS) represent two distinct yet significant classes of pollutants, both posing serious environmental and public health risks. Dyes in water contribute to intense coloration, elevated chemical and biological oxygen demand (COD and BOD), reduced light penetration, and disruption of aquatic ecosystems, with potential health risks to humans upon exposure. PFAS, often termed "forever chemicals," are synthetic organofluorine compounds associated with a range of adverse health effects, including endocrine disruption, …

Engaging Future Engineers: Utilizing Ai-Generated Video To Promote The Chemical Engineering Profession, Madeline G. Mondebello

Chemical Engineering Undergraduate Honors Theses

The expected incline of the chemical engineering profession faces a growing need to attract the next generation of prospective students. This research explores the use of artificial intelligence (AI) software to create an innovative form of media fit for secondary school and early college outreach. The pre- and post-video questionnaires were taken by a voluntary population comprised of high school students, college students, and parents. Overall, the feedback received was generally positive but indicated that the AI avatars and the lip-sync discrepancies may disrupt the video more than enhance it. In the future, a larger population will be surveyed to …

Aircraft Water And Waste Systems Curriculum Alignment For Updated Airmen Certificate Standards (Acs), Myles Miller

All Graduate Reports and Creative Projects, Fall 2023 to Present

The purpose of this project was to create a curriculum that aligns with the updated Airmen Certificate Standards (ACS) related to aircraft water and waste systems. The curriculum was designed to align with the FAA standards outlined in the ACS section II. Airframe Subject O. Water and Waste Systems. The curriculum includes components, operation, inspection, and servicing requirements for potable water and lavatory waste systems. The curriculum should equip students with the ability to identify, assess, and mitigate risks associated with lavatory waste systems, and the ability to locate and explain the procedures for servicing water and waste systems. The …

Engineering Planktonic And Biofilm Microalgae Systems For Productivity, Power Requirements, Cost, And Scalability, Dallin Chugg

All Graduate Reports and Creative Projects, Fall 2023 to Present

Microalgae cultivation offers dual benefits as an effective wastewater treatment method and a sustainable source of valuable bioproducts, such as biofuels, bioplastics, and feedstocks. This approach supports sustainability by transforming waste into high-value products while minimizing environmental impact. However, scaling microalgae cultivation to industrial levels presents significant challenges, particularly in optimizing harvesting efficiency, reducing mixing and transport costs, and managing large water requirements.

This report compares the productivity, scalability, cost, and energy requirements of two primary cultivation systems: planktonic and biofilm. Planktonic systems, such as open raceway ponds (ORPs), excel in light distribution and nutrient uptake due to continuous mixing, …

Ghosts In Glass: Ghost Crabs As Judges Of Glass Sand For Coastal Restoration, Emily Parrish

Honors Theses

Over 60% of the Gulf of Mexico coastline is actively eroding, which has resulted in thousands of miles of lost coastline over the last 100 years. This drastic loss of coastal land highlights the dire need for coastal restoration across the entirety of the Gulf Coast. A vital aspect of restoring these eroded areas is replenishing eroded substrate, traditionally conducted through offshore dredging of substrates which comes with high economic and ecological costs. Recycled glass sand may be able to fill this role and reduce our reliance on dredging while lowering the amount of glass waste entering landfills each year. …

Exploration Of Polymorphic Gate-Based Watermarking In Asynchronous Circuits, Stephanie Stock

Graduate Theses and Dissertations

With the increasing demand for new state-of-the-art integrated circuits (ICs), intellectual property (IP) reuse has become more commonplace to both accelerate the design process and lessen the non-recurring engineering costs of a design. Reuseable IP poses significant security risks, not only to the creator of the IP, but also to the consumer purchasing the IP. For an IP vendor, this risk can come from illegal distribution, cloning, or overuse. For the purchaser, counterfeit IPs may be purchased from an unvetted vendor, leading to a substandard design, malfunctions, IP infringement, or security vulnerabilities. Hardware watermarking is a method to protect designers …

In Vitro Investigation Of Macrophage Functional And Metabolic Modulation, Shelby Nicole Bess

Graduate Theses and Dissertations

Macrophages are a subset of immune cells with a variety of functions that are abundant in numerous tumor types such as colorectal and breast cancer. It has been suggested that macrophages may serve an important function as immune mediators in tumor behavior; however, macrophage activity is complex and remains not completely understood. The overall goal of this dissertation was to explore and exploit tumor-associated macrophage phagocytic function and the changes in their interactions with cancer cells in an in vitro mouse model and in 2D and 3D in vitro culture models. First, we wanted to better understand macrophage behavior under …

The Effect Of A Peptide Targeting Ligand On Transfection Efficiency Of Polymeric Nanoparticles To Dendritic Cells, Anthony Radka

Honors Theses

Autoimmune diseases affect approximately 5-8% of the global population, leading to chronic symptoms, long-term treatment, and reduced quality of life. Current therapies primarily rely on lifelong administration of immunosuppressants, which are associated with severe side effects and heightened susceptibility to infections. This has spurred interest in cellular therapies that manipulate dendritic cells (DCs) effectively and can selectively treat these diseases. This work aims to improve the efficacy of dendritic cell-based therapies using cationic polymers that can electrostatically complex with nucleic acids, forming nanoparticles referred to as polyplexes, that can deliver therapeutic nucleic acid cargo. These particles are a favorable alternative …

Development And Characterization Of A Pro-Angiogenic Peptide Amphiphile For Deep Dermal Burn Healing Via Spray Delivery, Loria Dimartino

Honors Theses

Severe burns and other dermatological injuries are frequently accompanied by a range of comorbidities and aesthetic challenges that patients must contend with. The complexity of burn care is exacerbated by the lack of a standardized surgical protocol, as treatment strategies are tailored to individual patient factors, including overall health status, wound size and location, as well as the expertise and resources available to the surgical team. Most commonly, deep dermal burns are treated through grafting, which effectively covers the injury site, but requires the creation of a second wound on the body of approximately the same size. This produces a …

Deciphering And Translating Bioinspired Structures For Engineering Materials Design Via Computational Modeling And Machine Learning, Zhangke Yang

All Dissertations

Nature has evolved extraordinary structural materials—such as nacre, bone, and the mantis shrimp’s dactyl club—that achieve remarkable combinations of strength, toughness, and impact resistance. These properties arise from sophisticated synergies between structure and composition. Inspired by these biological systems, this dissertation presents a comprehensive investigation into bioinspired materials, uncovering fundamental mechanisms and providing guidance on designing materials with superior mechanical properties.

This dissertation begins by examining the "brick-and-mortar" structure of nacre, which informs the design of layered polymer-graphene nanocomposite films. Using coarse-grained molecular dynamics simulations, I elucidate mechanisms of dynamic wave propagation and energy dissipation in these systems, providing critical …

Understanding Dimensional Stability Of Polymer Surgical Mesh, Simeon J. Mckelvey

All Dissertations

Polymer surgical mesh is a biomedical implant that has revolutionized the repair of the abdominal wall and pelvic floor. Each year, over 1.6 million Americans undergo surgical procedures using polymer surgical mesh to treat conditions where internal organs protrude through weakened tissues. This material is used in approximately 90% of hernia repairs, 80% of stress urinary incontinence procedures, and 30% of pelvic organ prolapse surgeries.

Despite this widespread use of polymer surgical mesh, post-implantation complications have prompted regulatory investigation and scrutiny. These complications stem from the mesh's behavior within the human body, including wrinkling, contraction, and loss of fixation, which …

Deep Learning In Lung Cancer Pre- And Post-Radiation Therapy: Diagnosis Of Malignancy And Radiation-Induced Lung Injury From 3d X-Ray Ct., Benjamin Peter Veasey

Electronic Theses and Dissertations

Lung cancer remains the leading cause of cancer-related mortality worldwide, with early detection and accurate diagnosis being critical for improving patient outcomes. Additionally, the progression of Radiation-Induced Lung Injury (RILI) following Stereotactic Body Radiation Therapy (SBRT) for lung cancer presents a significant diagnostic challenge. This dissertation addresses these challenges by developing deep learning-based diagnostic tools for both pre-treatment lung nodule malignancy classification and post-treatment RILI identification using 3D X-ray CT imaging. The research is divided into two primary objectives. First, for lung nodule malignancy classification, we developed a biopsy-confirmed dataset, called NLSTx, to train and evaluate deep learning models while …

A Case Study On Readiness Of Engineers In Agricultural Technology Start-Ups, Katie Marie Mowat

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

This dissertation explores the perceptions of practicing engineers regarding the skills necessary to be workforce-ready at agricultural technology (ag-tech) start-ups in the Midwestern United States. A qualitative case study methodology is leveraged, combining both interview and job description data. Given their uniqueness, the study divides the ag-tech start-up industry into two subcases: livestock and cropping systems. The Work Readiness Integrated Competence Model (WRICM) is used as the theoretical framework for this study and informs the conceptual framework and analysis processes. The study identified skills that fit into thirteen distinct categories, which are further grouped into four overarching resource groups. Skills …

Optimizing Nitrogen Management: Assessing Nitrate Transport In The Deep Vadose Zone And Its Impact On Groundwater Quality In East-Central Nebraska, Muili O. Lawal

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

Groundwater contamination by nitrate (NO₃-N) is a growing environmental and public health concern driven largely by intensive agricultural fertilizer applications. The vadose zone plays an important role in NO₃-N transport, influencing groundwater quality and agricultural sustainability. This study investigated NO₃-N leaching dynamics in the deep vadose zone of Water Quality Sub-Area 30 (WQA30) within the Lower Loup Natural Resources District (LLNRD), northeast of Columbus, Nebraska (mean groundwater NO₃-N: 20.3 mg/L), using soil cores from 16 shallow (to 6.1 m) and four deep (down to 25.9 m) across four zones, two with inorganic fertilizer (Zones 1 and 4) and two with …

Assessing Sleep Quality In A Preclinical Model Of Low Back Pain Through Novel Noninvasive Methods, Lydia C. Saltz

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

Chronic low back pain (LBP) has widespread negative impacts on quality of life. Current treatments for chronic LBP fail to provide long-term efficacy and motivate the need to understand key drivers of poor patient outcomes. Mounting evidence indicates that sleep disturbances and chronic LBP have a strong reciprocal relationship. Women may be particularly vulnerable to the negative impacts of the sleep-pain axis, exhibiting greater prevalence in both conditions. However, the relationship between sleep, pain, and sex remains understudied. Preclinical models can be used to parse out characteristic sleep features that degrade with pain, which can be further broken out by …

A Comprehensive Analysis Of Virtual Reality In Modern Healthcare Education, Adarsha Ganesan

Honors Program: Senior Projects (Public)

This thesis evaluates the effectiveness of virtual reality (VR) in healthcare education through multiple facets of evaluation: educational outcomes, accessibility considerations, and financial viability. Drawing from an extensive literature review on existing research and a case study of the University of Nebraska Medical Center (UNMC) College of Nursing's "Journey Through the Kidney" VR experience, this analysis examines how technology can transform modern medical education. While research shows mixed results regarding virtual reality’s impact on assessment outcomes, studies demonstrate increased student motivation and engagement, which can have lasting downstream effects on the quality of learning. Accessibility analysis reveals both opportunities and …

Using Optical Dielectrophoresis For Microbead And Cell Manipulation, Leigh K. Smith

Mechanical Engineering Undergraduate Honors Theses

Dielectrophoresis is a common method used to manipulate particles on the microscopic scale. Optically Induced Dielectrophoresis or ODEP is the specific method used in this research. All experiments were conducted in Dr. Tung’s Micro and Nano Systems lab at the University of Arkansas’ ENRC. An ODEP system was created in the lab for manipulating microbeads (6-10 micrometers (μm) in diameter) and E. coli cells (1-2 μm in diameter).

Experiments were performed on the microbeads to see how changing the parameters of the device affects the force caused by ODEP on the beads. The parameters that could be changed in the …

Sustainable Agriculture Through Data-Driven Land And Soil Management For Rural Farming Communities, Peggy Clareece Discenza

Open Access Theses & Dissertations

This thesis aims to investigate sustainable farming practices by utilizing a database containing soil, weather, and water data. Additionally, it evaluates cropping strategies using a system that incorporates nutrient dynamics and environmental values. The objective is to monitor, develop predictive models, and assess the impact of both controlled and uncontrolled nutrient variables. This is achieved through the development of an algorithm that provides information on soil health based on datasets and land use, with a particular focus on residual values after harvesting for deeper analytical insights and interpretation. This study focuses on key nutrients, including pH levels, water availability, and …

Advancing Additive Manufacturing For Extreme Environments Through Simulated Microgravity Printing, Laura Nayeli Molina

Open Access Theses & Dissertations

Additive Manufacturing (AM) holds significant potential for space exploration by enabling on-demand fabrication of components, reducing payload costs, and enhancing mission adaptability. However, microgravity introduces challenges in thermal regulation, material deposition, and structural integrity. This research explores the feasibility of submerged AM using neutral buoyancy in silicone oil to simulate microgravity conditions on Earth. A 3D printer was modified for submerged operation, with samples printed under three conditions: no oil (ambient air), submerged in oil, and simulated microgravity at varying temperatures. Mechanical tests, fracture surface analysis, and density measurements were performed to evaluate tensile strength, surface adhesion, and dimensional stability. …

Fibrin-Polycaprolactone Scaffolds For The Differentiation Of Human Neural Progenitor Cells Into Dopaminergic Neurons, Salma Paulina Ramirez

Open Access Theses & Dissertations

This project aimed to develop a tissue-on-a-chip platform for studying Parkinson's Disease (PD) using dopaminergic (DA) neurons. PD is a neurodegenerative disorder characterized by progressive loss of DA neurons, leading to involuntary movements and other symptoms. Early diagnosis and deeper understanding of PD pathogenesis are crucial for improving disease management and patient outcomes. To model PD in vitro, this research utilized human-induced pluripotent stem cell (hiPSC)-derived neural progenitor cells (NPCs) cultured on electrospun (ES) polycaprolactone (PCL) scaffolds. Given PCL's hydrophobicity, ECM-based biomaterial coatings, including Cell Basement Membrane (CBM) proteins, Matrigel, and Fibrin, were explored to enhance NPC adhesion, differentiation, and …

Involvement Of Long Non-Coding Rna (Lncrna) Malat1 In Shear Stress Regulated Adipocyte Differentiation, Justin Caron, Marjan Ghanbariabdolmaleki, Madison Marino, Chong Qiu, Bo Wang, Michael Mak, Shue Wang

Biomedical Engineering Faculty Research and Publications

Adipocyte differentiation plays an important role in bone remodeling due to secretory factors that can directly modulate osteoblast and osteoclast, thus affecting overall bone mass and skeletal integrity. Excessive adipocyte differentiation within the bone marrow microenvironment can lead to decreased bone mass, eventually causing osteoporosis. The mechanical microenvironment of bone marrow, including fluid shear, maintains the balance of adipocyte and osteoblast differentiation during bone remodeling. However, how mechanical cues interact with long noncoding RNA (lncRNA) and regulate adipocyte differentiation remains unexplored. In this study, we investigated the mechanosensitive role of lncRNA MALAT1 during mesenchymal stem cells (MSCs) adipocyte differentiation. By …

A Neuroimmune Circuit Mediates Chemo Brain Pathology, Daniel Ahmadi

McKelvey School of Engineering Graduate Student Theses & Dissertations

Chemotherapeutic agents, while effective in targeting malignant tumors, often reduce the patients’ quality of life by inducing fatigue, pain, and motivational deficits. These symptoms are collectively referred to as “chemo brain.” The mechanisms underlying these adverse effects, and specifically whether fatigue and motivational impairments share a common etiology, remain poorly understood. The neural–immune substrates of these symptoms remain obscure, in part because standard preclinical regimens either bypass key systemic signals or introduce local toxicity confounds. Here, I establish and validate a three‑day, low‑dose intravenous cisplatin protocol that avoids peritoneal inflammation and severe renal injury yet produces robust, reversible fatigue and …

Mechanistic Investigation Of Ring-Opening Polymerization Of Polycaprolactone Using Tin(Ii) Catalysts: Ligand Effects And Biomedical Applications, Eva-Larue M. Barber

Honors Scholar Theses

This research explores the mechanistic aspects of ring-opening polymerization (ROP) of ε-caprolactone (CL) to produce polycaprolactone (PCL), a biodegradable polymer widely used in biomedical applications. The study investigates how light exposure and catalyst concentration influence polymerization efficiency, using tin(II) 2-ethylhexanoate [Sn(Oct)₂] as the catalyst in a non-polar toluene solvent at 90 °C. Reactions were conducted under either ambient light or black light bulb (BLB) illumination, with monomer-to-catalyst ratios of 1:1 and 200:1.

Proton nuclear magnetic resonance (¹H NMR) spectroscopy was used to analyze conversion efficiency by tracking the disappearance of monomer signals and appearance of characteristic PCL peaks. Results revealed …

Advancing Precision And Autonomy In Agriculture And Medical Imaging Through Ai And Computer Visions, Tan-Hanh Pham

Theses and Dissertations

Deep learning has revolutionized numerous fields by enhancing precision, automation, and decision-making capabilities. This dissertation explores its applications in agriculture and medical image processing, introducing novel methodologies to improve accuracy and efficiency in these domains. These fields hold critical societal importance -- agriculture underpins global food security and sustainability, while medical imaging drives advancements in diagnostics and personalized healthcare, both benefiting significantly from data-driven innovations. In agriculture, deep learning is applied to precision spray systems through droplet analysis. Specifically, a generative model is designed to create synthetic droplet images, addressing the challenge of limited training samples, which are expensive …

Synthesis And Characterization Of Composite Hydrogels For Tissue Engineering: An Investigation On Mechanical Properties And Biocompatibility, Ismael Lamas Jr.

Theses and Dissertations

This study investigates the fabrication and characterization of Polyvinyl Alcohol (PVA)/agar double-network (DN) hydrogels for biomedical applications, focusing on mechanical strength, biocompatibility, and tissue engineering potential. Techniques like swelling ratio analysis and Fourier-transform infrared spectroscopy (FTIR), alongside antibacterial and cytotoxicity assays, were employed to evaluate the hydrogels' properties. Results show that increasing agar content enhances mechanical and physical properties, with swelling ratios increasing by 300% when agar makes up 6% of the hydrogel, compared to 140% without agar. A positive correlation was observed between agar concentration and compressive and tensile moduli. Load-relaxation rates, essential for viscoelastic properties, also improved with …

Multistage Random Key Genetic Algortihm Optimization For Scheduling Flexible Flow Lines With Sequence Depenedent Setup Times, Aadithan Anbuvanan

All Theses

This thesis proposes a new variation to the Random Key Genetic Algorithm (RKGA) for scheduling optimization in flexible flow line manufacturing with sequence dependent setup times. The proposed RKGA representation decodes scheduling information independently at each stage, unlike the traditional RKGA, which is only sequenced based on the first stage, limiting flexibility. The proposed method's performance is compared to the traditional method with varying numbers of jobs and stages. It is compared regarding performance ratio and statistical significance of differences through the Wilcoxon Signed Rank Test. Results show that the proposed RKGA outperformed traditional RKGA in high complexity (8 Stage …

Impact Of Shear Flow On Marine Biofilms Using Hyperspectral Imaging, Shantanu Mahesh Kore

All Theses

Various microbial communities in marine biofilms cause biofouling on submerged surfaces, posing challenges to marine industries. Despite their ecological and economic importance, biofilms' biomechanical and biochemical responses to hydrodynamic shear stress are insufficiently understood, particularly in dynamic flow conditions. To fill this gap, our study uses an innovative fiber-optic hyperspectral imaging (HSI) system and a supercontinuum laser source to examine marine biofilms' structure, composition, and detachment behavior at different shear stress levels.

To detect spectral and spatial heterogeneity in live biofilms without labeling, we created a custom imaging pipeline that captures reflectance spectra in the 600-850 nm range, targeting microbial …

Stability Of Holes In Granular Raft, Plabon Kumar Saha

All Theses

A granular raft at an oil–water interface exhibits unique mechanical properties, including the ability to form and sustain stable holes. In this study, we experimentally investigate the formation, stability, and collapse dynamics of holes in particle rafts composed of micrometer-sized particles. Holes are created using a hollow cylinder, which generates a meniscus that inhibits particle motion, thus stabilizing the hole. Stable holes are formed when their size reaches a critical value, which depends upon the capillary length. The critical hole size does not depend upon the circularity of the hole. We show that capillary forces due to the presence of …