Engineering Commons^™

Accessibility And Usability Of Medical Devices For Users With Disabilities: Insights From A Bibliometric And Thematic Analysis, Karen Daniela Gonzalez Silva

Open Access Theses & Dissertations

No abstract provided.

Enhancing The Utility Of Unmanned Autonomous Vehicles (Uavs) With Model-Based Systems Engineering (Mbse) And Modular Open Systems Approach (Mosa), Aimee Barraza

Open Access Theses & Dissertations

Unmanned Autonomous Vehicles (UAVs) have emerged as versatile tools with significant implications across various industries, particularly in defense. The technological advancements in UAVs have revolutionized military operations, surveillance, and reconnaissance capabilities. However, there exist challenges such as environmental factors affecting sensor and flight performance, limited battery life restricting flight durations, and payload capacity constraints impeding task efficiency.This paper delves into the importance of UAVs in different industries, specifically focusing on their pivotal role in the Department of Defense. It emphasizes the necessity of technological upgrades to overcome current challenges and proposes the adoption of a Modular and Open System Approach …

Synthesis Of Materials For Additive Manufacturing Of Enhanced Polymers And Textured Ceramics, Diana Fontes

Open Access Theses & Dissertations

This research will be divided into two sections. The first section investigates the development of textured Barium Titanate (BaTiO3) ceramics fabricated through Direct Ink Write Printing (DIW) integrated with Templated Grain Growth (TGG). This approach aims to develop lead-free piezoelectric materials with grain alignment during printing process to promote high piezoelectric performance comparable to those in lead-based ceramics. This research evaluates the impact of the DIW-TGG process on grain orientation, material densification, and piezoelectric response, illustrating its potential for developing high-performance ceramics for advanced applications such as sensors, actuators, and other piezoelectric devices. The second project explores the chemical stability …

General Purpose Gpu Benchmarks For Neural Networks, Jose Maria Granados

Open Access Theses & Dissertations

Neural networks are a field of computing experiencing a rise in popularity in recent years due to the utilization of graphics processing units as their computational centerpiece. The lack of neural network benchmarks for the open-source Nyuzi architecture, a developing general-purpose processor with graphical processing capabilities, is the focus of this thesis. This work aims to determine whether Nyuziâ??s performance counters and traceable events suffice for performance tuning of neural network implementations. Given the mathematical intensity of neural networks, a strong emphasis is placed on events related to arithmetic instructions. Experimenting with neural network implementations in C and C++, existent …

Vertically Aligned Nickel Cobalt Molybdenum Copper Oxide Nanotubes For High Performance Asymmetric Supercapacitors, Ricardo Herrera Aguirre

Open Access Theses & Dissertations

Designing materials having novel multi metal oxide electrodes with controlled structure and composition is a critical technological challenge for high performance supercapacitor applications. Quaternary metal oxides have attracted considerable attention in this field, where many methods have been used to improve their performance. In the present work, the nickel cobalt molybdenum copper oxide (NCMCuO2) has been synthesized using a hydrothermal method. The effect of different concentrations of Cu doping (0.5%,1.0% and 2.0%) on the NCM frame and structural and electrochemical properties of the quaternary metal oxide (NCMCuO2) are studied thoroughly. The XRD pattern of synthesized NCMCuO2 exhibited predominant (002) orientation …

Chipless 3d Microfluidic Rf Sensing, Sheikh Dobir Hossain

Open Access Theses & Dissertations

Effective management of the cold chain is essential to uphold the quality and safety of products vulnerability to physical factors like temperature, humidity, pressure, etc., including perishable foods, pharmaceuticals, and vaccines. Chipless Radio Frequency Identification (RFID) sensors have become increasingly favored as a viable technology for tracking, inventory, and sensing industries due to their wireless and non-line of sight (NLOS) situations, straightforward fabrication, cost efficiency, and adaptability to challenging environmental conditions. However, there is still a need for advancements in RFID sensors to make them promise for cold chain applications. Integration of flexibility and non-volatile memory into the existing RFID …

Thermal Analysis Of Combustion Synthesis Of Fealxoy Catalysts For Dehydrogenation Of Fossil Fuels, Laura Alejandra Martinez Espinoza

Open Access Theses & Dissertations

The growing demand for hydrogen as a clean energy carrier highlights the need for its alternative production method with reduced CO₂ emissions. Microwave-assisted thermocatalytic dehydrogenation of fossil fuels offers a promising solution for clean hydrogen production, with FeAlxOy nanocomposites acting as efficient catalysts due to their thermal stability, catalytic activity, and microwave-absorption properties. FeAlxOy nanocomposites, fabricated by solution combustion synthesis (SCS), have shown good microwave-absorption and catalytic properties. However, the effects of synthesis parameters such as fuel type and Fe:Al molar ratio on the SCS process and properties of the final material are not well understood. The SCS process involves …

Elucidating The Effect Of Milled Glass And Graphite Fiber On The Quasi-Static Properties Of Vinyl Ester Resin Composites, Sarahi Mendivil

Open Access Theses & Dissertations

Composite materials can be tailored to various applications, making them one of the most conventional materials. Their ability to enhance desired characteristics enables higher strength while maintaining light weight. However, understanding defects and manufacturing limitations is crucial for optimizing their fabrication processes. This paper focuses on the manufacturing processes of open molding with controlled variations to establish an optimal technique aimed at minimizing defects, such as bubble formation where the focus is on mitigating defects and ensuring uniform dispersion of fiber in fiber-reinforced composites. After refining the manufacturing process, composites with varying resin-to-fiber concentration ratios were manufactured using glass and …

Ultra-High Temperature Ceramics: Materials, Manufacturing, And Machine Development, Joseph Matthew Munoz

Open Access Theses & Dissertations

This research aimed to advance the 3D printing of ultra-high-temperature ceramic matrix composites (UHTCMCs) and develop a custom Direct Ink Writing (DIW) system with multimaterial and in-line mixing capabilities. The study first focused on creating ZrB₂–SiC composites reinforced with aligned silicon carbide fibers (SiCf) using paste extrusion. By formulating suspensions with a preceramic polymer (SMP-10), ZrB₂, and SiCf, the study assessed how fiber alignment influenced key properties such as thermal and electrical conductivity and mechanical strength. Green curing and pyrolysis transformed the printed parts into UHTCMCs, with results showing substantial improvements in thermal conductivity—nearly double that of non-aligned parts—and a …

A Blue Hydrogen Framework For Regional Energy Resiliency, Safwan Shafquat

Open Access Theses & Dissertations

High-pressure gasification is gaining attention as an emerging solution for sustainable energy production due to its potential to achieve higher efficiencies, improved syngas quality and smaller equipment footprints. High operating pressures and temperatures can increase the synergistic reactivity of biomass and organic materials, consequently enabling higher in situ tar reformation and ultimately reducing the number of gas treatment requirements. Additionally, higher operating pressures result in a more concentrated CO2 stream and reduce the amount of post-gasification compression requirements in the carbon capture and storage (CCS) unit, improving overall system efficiency. Plus, pressurized CO2 streams from the gasifier also provides routes …

Gate Driver Design In High-Temperature Cmos Process For Heterogeneous Integration Inside Sic Power Module, Khandoker Asif Faruque

Graduate Theses and Dissertations

The shift toward electrification in transportation, including electric and hybrid vehicles, presents challenges for power electronic converters. Silicon Carbide (SiC) power devices are promising due to their high efficiency, temperature tolerance, and reduced losses compared to traditional silicon devices. However, their use is hindered by issues such as parasitic capacitances and gate inductances, which can lead to voltage spikes and stress on the device gate oxide, hence impacting converter reliability. Increasing gate resistance can help manage these issues, but it reduces switching speed and increases losses. Snubber circuits can mitigate switching stress but add extra components, reducing efficiency. Active gate …

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 …

Virtual Control: A Comparison Of Methods For Hand-Tracking Implementation, Nathan Roberts

Honors Program: Senior Projects (Public)

This thesis examines the design philosophy of modern virtual reality applications that utilize hand-tracking as a primary form of user input. The analysis presented hopes to provide ideas for future implementations of this technology so that more immersive experiences are developed. This analysis starts with the discussion of a modern example of successful hand-tracking implementation, then comparing that implementation to a recent senior design project. This comparison is primarily based on each experience’s ability to create interactivity and immediacy. Interactivity is the degree to which the user can quickly and reliably make changes to their virtual environment, while immediacy is …

An Overview Of Planning For Vehicle-To-Grid Systems With Large-Scale Adoption Of Electric Vehicles, Fazel Mohammadi, Mahmood Mirhashemi

Electrical & Computer Engineering and Computer Science Faculty Publications

The rapid adoption of Electric Vehicles (EVs) has the potential to transform energy infrastructure worldwide. Vehicle-to-Grid (V2G) systems, which enable bidirectional energy flow between EVs and power grids, offer a promising solution for balancing electricity demand, supporting renewable energy integration, and enhancing the resilience of power grids. This paper explores different strategic planning considerations necessary for the large-scale adoption of V2G-enabled EVs, aiming to support a more resilient and sustainable energy infrastructure.

Fitting Quality Of Nmr Relaxation Data To Differentiate Asphalt Binders, Rebecca M. Herndon, Kevin Lai, Magdy Abdelrahman, Klaus Woelk

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder performance grades (PGs) are important metrics in designing pavements for effective transportation infrastructure. the PG system relies on the binder's stiffness and is determined through energy- and time-intensive physical testing. Physical properties, like stiffness, can also be determined by spin–lattice NMR relaxometry, a non-destructive chemical method. NMR relaxometry can quantify the molecular mobility of materials by determining relaxation times from exponential decays of excited nuclear magnetization. While relaxation times have been used to determine physical properties of materials, a quantitative relation to the PG grades of asphalt binder is yet to be established. in this study, T1 NMR …

Argument Schema Of Undergraduate Engineering Students, Anu Singh

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

Critical thinking is one of the most desired skills in the workplace, as it assists an individual in solving complex problems and making informed decisions, resulting in their workplace success. Argumentation is one instructional approach that provides students an opportunity to engage in higher-order thinking and improve their communication skills. Argumentative writing provides opportunities to engage in multiple perspectives of a problem, provide evidence for the claim, evaluate evidence, engage in reasoning, and acknowledge self-bias, which automatically engages students in critical thinking. Previous literature has shown that despite the use of interventions and scaffolding approaches, students' argumentative texts lack elements …

Modeling And Understanding Of Additive Manufacturing Periodic Cellular Structures With Heterogeneity: Property, Quality And Design Strategy., Naresh Koju

Electronic Theses and Dissertations

Lightweight cellular structures with their higher per mass performance capability, multifunctional designability and property tolerability are gaining much wider adaptation in many engineering applications ranging from aerospace, defense, biomedical, automotive to sports. However, to achieve the desired performance levels careful design must be carried out. The experimental-based empirical design often involves high manufacturing cost, and there are also certain information/knowledges about the cellular deigns that could not be easily obtained experimentally, such as the deformation local fracture initiation. Similarly, numerical modeling-based design approach commonly suffers from high computation cost and the lack of inverse designability. In addition, numerical models often …

Interaction-Sensitive Tree-Based Statistical Models, Xiaotong Sun

Graduate Theses and Dissertations

This dissertation introduces a tree-based framework to improve the interpretability and modeling of interaction effects among variables, essential in fields like biostatistics, healthcare, science and engineering. Traditional regression methods often fail to clearly capture complex interactions, while tree-based approaches, despite their interpretability, face performance limitations and overfitting concerns. Our proposed interaction-sensitive tree-based method, designed for seamless integration, combines various statistical techniques tailored to different data types, leveraging ensemble learning methods to enhance accuracy and mitigate overfitting. We present methods for regression, survival analysis, and classification, validated with case studies and benchmarked against traditional models using metrics like BIC and R-squared. …

Wind Tunnel Investigation Of The Along-Wind Dispersion In Finite-Duration Neutrally Buoyant Gas Releases, Daniel Williams

Graduate Theses and Dissertations

This thesis investigates the along-wind dispersion of hazardous gas releases within a turbulent boundary layer using controlled experiments in an ultra-low-speed wind tunnel, recognizing the limitations of numerical modeling and field tests. This study utilizes a neutrally buoyant gas mixture and dual Flame Ionization Detectors (FIDs) to capture representative, repeatable data on gas cloud behavior over finite durations. Ensemble averaging of 65 trials across varying release durations and downwind distances provided detailed insights into gas dispersion and the distinct time phases within finite-duration releases. Analysis revealed that along-wind dispersion coefficients depend on turbulence and vertical wind shear, with normalized coefficients …

Characterizing Locust Anemotaxis: The Impact Of Sensory Perturbations On Flight Behavior, Yi-Xiao Huang

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis investigates the effects of sensory perturbations on locust flight behavior, with the goal of better understanding how locusts integrate multiple sensory inputs to maintain flight control. Through a series of experiments, locusts were subjected to visual impairment, turbulent wind conditions, mechanical impairments of their wings and antennae, and pheromonal interference. These perturbations allowed for the exploration of the contributions each sensory pathway makes to flight stability and navigation in a controlled environment.

Results show that while visual impairment does not significantly impact average flight speed, it increases variability in flight stability, suggesting that visual cues are important for …

Human-Aware Motion Planning For Aerial Robots, Beichen Zhou

McKelvey School of Engineering Graduate Student Theses & Dissertations

This project shows a combination for drones autonomous navigation in dynamic environments. The algorithm combine Social GAN SGAN for human trajectory prediction with Rapidly-exploring Random Tree Star RRT* for path planning. The objective is to efficiently and safe navigate in the area with human. Drones would avoid moving human and maintaining optimal flight path. During training SGAN model, we use both public datasets and dataset collected in the lab, which improve its adaptability in the lab. This experiment was tested through simulations and real-word experiment. SGAN provided a good prediction of human trajectories, which help drones to adjust their path. …

Type Ii Innate Lymphoid Cell Plasticity Contributes To Impaired Reconstitution After Allogeneic Hematopoietic Stem Cell Transplantation, Sonia J. Laurie, Joseph P. Foster, Danny W. Bruce, Hemamalini Bommiasamy, Oleg V. Kolupaev, Mostafa Yazdimamaghani, Samantha G. Pattenden, Nelson J. Chao, Stefanie Sarantopoulos, Joel S. Parker, Ian J. Davis, Jonathan S. Serody

Chemical and Biochemical Engineering Faculty Research & Creative Works

Type II innate lymphoid cells (ILC2s) maintain homeostasis and barrier integrity in mucosal tissues. In both mice and humans, ILC2s poorly reconstitute after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Determining the mechanisms involved in their impaired reconstitution could improve transplant outcomes. By integrating single-cell chromatin and transcriptomic analyses of transplanted ILC2s, we identify a previously unreported population of converted ILC1-like cells in the mouse small intestine post-transplant. Exposure of ILC2s to proinflammatory cytokines resulted in a mixed ILC1-ILC2 phenotype but was able to convert only a small population of ILC2s to ILC1s, which were found post-transplant. Whereas ILC2s protected against …

Delineating Genetic Influences On Neurodegenerative Disorders And Infectious Diseases Through Advanced Computational Methods, Xiaowei Zhuang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Genetics plays a critical role in understanding the molecular mechanisms underlying neurodegenerative disorders and pathogen evolution in infectious diseases. For example, identifying genetic variants associated with a disease phenotype uncovers functional pathways that could lead to potential drug targets and therapeutic interventions. In addition, tracking the genetic evolution of pathogens enables early detection and warning of infectious disease outbreaks. In both applications, given the large amount of genetic data, advanced computational methods, including longitudinal and multivariate models, could significantly boost the statistical power and capture interrelationships among traits, environmental factors and genetic influences. This dissertation focuses on four applications of …

Model Reference Adaptive Control For Mobile Manipulators And Beyond, Srivatsan Srinivasan

All Dissertations

In recent years, robotics has expanded into various sectors, including manufacturing, transportation, and household services, making the integration of autonomy a critical area of research. This shift aims to ensure safety and enhance the utility of autonomous systems. Traditionally, robotic applications focused separately on mobility, like automated guided vehicles, and manipulation, such as serial-chain arms in manufacturing. Today, however, we see a merging of these capabilities in the growing field of mobile manipulator robots that combine movement with purposeful interactive functionalities.

A typical mobile manipulator is a robotic arm mounted on a wheeled base. This thesis focuses on advancing control …

Regulating Cox Conversion Through Catalyst Design And Reaction Energy Input, Ewa Chukwu

All Dissertations

Carbon dioxide (CO₂) emissions, primarily from fossil fuel use in energy and chemical production, are the leading driver of global warming. The chemical industry is the third-largest source of these emissions, so reducing its carbon footprint—and ultimately achieving “CO₂ emissions-free” chemical manufacturing—is critical to combating global warming. Thermal catalysis is the workhorse of industrial chemical manufacturing, generating CO₂ emissions from two main sources: the actual chemical transformations of fossil feedstocks and burning of fossil fuels to provide the process heat. Therefore, developing and implementing technologies to mitigate the carbon emissions associated with these emissions sources is essential for decarbonizing the …

Deformation Mechanism In Gold Nanoparticles Under Compressive Loading: Insights From Atomistic Modelling And Unsupervised Machine Learning, Tanuj Gupta

All Dissertations

Gold nanoparticles (AuNPs) offer exciting possibilities due to their inertness, malleability, and tunable structures, making them valuable for applications ranging from nanomedicine to electronics. Their optical, mechanical, and other properties can be tailored by modifying shape and structure, underscoring the importance of understanding their deformation behaviour at the nanoscale. This study used classical molecular dynamics simulations with LAMMPS to investigate the deformation mechanisms of gold nanospheres (AuNS) under uniaxial compression. Employing the embedded atom method (EAM) potential to model atomic interactions, AuNS with 20 nm in diameter were compressed along the z-direction using planar indenters moving at a constant …

The Clot Thickens: Investigation Of The Mechanism Behind Hypercoagulation In Covid-19 Patients, Toni Warnick

All Dissertations

Since its emergence in 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been associated with cardiovascular complications, which correlate with illness severity and increased mortality. It was initially thought that this hypercoagulable state was induced by endothelial dysfunction or cytokine storm because of SARS-CoV-2 infection. Although platelets have been reported to express the SARS-CoV-2 primary target receptor, angiotensin-converting enzyme 2 (ACE2), this remains controversial due to conflicting findings that suggest minimal to no ACE2 expression on platelets. This ambiguity has led to exploring alternative entry pathways, notably via the virus’s RGD (arginine-glycine-aspartic acid) sequence within its spike protein receptor-binding …

Isolation And Upgrading Of Lignin From Agricultural Sources Using Phase Equilibria, Bronson Lynn

All Dissertations

In the emerging bioeconomy, agricultural residues from our nationwide crop harvests are positioned to be a cornerstone of renewable and sustainable fuels, chemicals, and materials. However, to be economically viable, the basic constituents of this plant matter must be separated and funneled to the appropriate application to maximize value and overall usability.

This work focuses on the component that has, to this point, been largely left behind: lignin. Although it is the most abundant aromatic biopolymer on the planet, making up 15-40% of grasses, hardwoods, and softwoods, the processing involved to isolate usable lignins is too complex and expensive to …

Collision Hazard Prevention And Notification For Construction Worker Safety Using Audio Surveillance, Kehinde Elelu

All Dissertations

The construction industry faces significant safety challenges, with collision hazards ranking as the second highest cause of annual fatalities and injuries in the United States, as reported by the Occupational Safety and Health Administration (OSHA). Current collision detection methods predominantly rely on proximity technologies, which necessitate costly and complex installations on each construction equipment piece. Furthermore, auditory situational awareness declines among workers due to hearing loss and intricate construction noises, which further heightens collision risks. This research introduces an innovative, low-cost, audio-based collision prevention technology aimed at enhancing auditory situational awareness for construction workers exposed to high noise levels. The …

Estimating The Possible Qpos Of M87* From The Parameters Of A Hairy Kerr Black Hole, Orhan Donmez, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

In this paper, we study the dynamics of the shock cone formed around a hairy Kerr black hole due to Bondi– Hoyle–Lyttleton (BHL) accretion and investigate the quasi-periodic oscillations (QPO) behaviors resulting from the black hole-cone interaction, aiming to predict the QPO frequencies that may occur around the M87∗ black hole. To achieve this, we use the hairy Kerr black hole parameters consistent with the observed shadow parameters of M87∗ as initial conditions in numerical simulations, revealing the structure of the resulting shock cone and QPOs in a strong gravitational field. Numerical calculations show that the deviation of …