Engineering Commons^™

Dynamic Modeling Of A Nuclear Integrated Energy System With Thermal Energy Storage And Hydrogen Production, Seth J. Dana

All Graduate Theses and Dissertations, Fall 2023 to Present

Historically, nuclear reactors have used water for cooling and moderating the nuclear reaction within the core. Advanced generation IV nuclear reactors currently under development are designed with different coolants which enable operation at higher temperatures. A higher operating temperature makes nuclear power suitable for co-located hydrogen production via high temperature electrolysis. Natrium, an advanced reactor design by TerraPower and GE Hitachi, combines a sodium fast reactor with molten salt thermal energy storage. The work presented in this thesis models and analyzes three Natrium systems which integrate hydrogen production with the Natrium nuclear power plant. The first two configurations focus on …

Trade-Offs In Lighting For Dic Strain Measurements In Vibration-Based Fatigue Testing, Jacob R. Rigby

All Graduate Theses and Dissertations, Fall 2023 to Present

Vibration based fatigue testing offers a fast and efficient method for determining the breaking point of a material. This method often uses a device, called a strain gage, to measure the deformation of a test sample at a single spot on the test sample. However, these strain gages often break before testing is complete. To overcome this premature break, a laser vibrometer is often used to measure the amount of movement or the speed of the test sample throughout the vibration test. The deformation measured by the strain gage is compared against the amount of movement or velocity of the …

Cislunar Optimal Robust Trajectory Design With Corrective Maneuvers, Scott J. Kelly

All Graduate Theses and Dissertations, Fall 2023 to Present

One common method for determining how to get from point A to point B is by finding the most fuel-efficient path. This is a common method for spacecraft trajectory designers also. Without any random or unexpected occurrences this path is called the deterministic optimal trajectory. Sometimes unexpected events happen that result in deviating from the most fuel-efficient path; while driving, you may encounter a detour. Naturally, we tend to return to the original fuel-efficient path and continue the journey. Similar deviations happen in space. The rocket delivering a spacecraft to orbit likely will not deliver exactly to the intended starting …

Quantifying Plot-Scale Evapotranspiration In Northeast Utah, W. Sheridan Stewart

All Graduate Theses and Dissertations, Fall 2023 to Present

Evapotranspiration, the combined movement of water from the earth's surface and plants to the atmosphere, is a component of the energy balance of the land surface atmosphere continuum. Often, irrigation is used to replace water removed from the soil through evapotranspiration. Water management for irrigation is often done at the plot or field scale. Due to the smaller footprint size and the large upfront costs, evaluating evapotranspiration at such a small scale can be difficult to justify. The aim of the study was to quantify evapotranspiration at the plot scale. An energy balance model that evaluates energy from two sources, …

Effect Of Nutrient And Temperature Conditions On The Production Of Microcystins From Cyanobacteria In Pineview Reservoir, Brent G. Jacobson

All Graduate Theses and Dissertations, Fall 2023 to Present

Cyanobacteria, sometimes known as harmful algae, are an aquatic bacteria capable of producing toxic compounds. Cyanobacteria are found worldwide in both saltwater and freshwater environments. Depending on the environment, toxic cyanobacteria species can outcompete other aquatic species, grow in large numbers, and produce these toxic compounds. Further understanding of what environmental conditions promote the production of these harmful bacteria and toxins is needed to protect and inform the public.

In order to understand why cyanobacteria produce toxins in certain environments, samples containing cyanobacteria were taken from a Pineview Reservoir, Utah, and cultured at the Utah State Water Research Laboratory. Cyanobacteria …

Assessment Of Future Streamflow In The Colorado River Basin With Some Implications For Water Management, Homa Salehabadi

All Graduate Theses and Dissertations, Fall 2023 to Present

Long-range water supply planning in many river basins, such as the Colorado, requires assessing plausible future streamflow scenarios. Given nature's randomness and climate change, it is important to evaluate water resources system behavior under a wide range of plausible conditions. The research described in this dissertation examined various future streamflow scenarios in the Colorado River Basin to provide essential inputs needed for planning in the uncertain future. First, the research examined historical severe droughts in the basin and created three sets, or ensembles, of plausible future streamflow time series by resampling these past droughts. These ensembles are thus consistent with …

Rapid Prediction Of Buoyancy-Driven Exchange Flows At The Great Salt Lake: Ml Models And A 1d Shallow Water Approach, Eric M. Larsen

All Graduate Theses and Dissertations, Fall 2023 to Present

The Great Salt Lake in Utah, USA, is a hypersaline terminal lake divided in to northern and southern arms by the Union Pacific Railroad causeway since the 1950's. This separation has caused a difference in density and water surface elevation between lake arms. These differences result in a buoyancy-driven exchange flow occurring through an engineered breach in the causeway. Traditionally, modeling the flow through the breach has been done by numerically solving the 1D steady shallow water equations, and using computational fluid dynamics (CFD). The CFD models yield high accuracy results, but require substantial computing resources. This research proposes the …

Thermal Management Of Roadway-Embedded Power Electronics For Electric Vehicle Dynamic Wireless Charging Systems, Conner R. Sabin

All Graduate Theses and Dissertations, Fall 2023 to Present

Electric vehicles (EVs) are gaining popularity worldwide. However, concerns raised by the public about purchasing EVs include the limited availability of charging infrastructure, high costs, and the inconvenience of current charging methods. Dynamic wireless charging systems enable electric vehicles to charge while driving, thereby extending the range of EVs and reducing the necessity for large, expensive batteries. Moreover, these systems can initiate charging automatically without user interaction, enhancing charging convenience.

The ground assembly of existing dynamic wireless charging systems consists of an electromagnetic assembly, power electronics for the transmitter pad, and power electronics for grid connection. Installation of these systems …

Recent Progress In Microencapsulation Technology And Its Applications In Petroleum Industry, Jingyi Zhu, Jiayu He, Jie Zhou, Zhaozhong Yang, Xiaogang Li, Ying Li, Zhenjiang You

Research outputs 2022 to 2026

Oilfield chemicals play a pivotal role in optimizing the development of oil and gas resources. Emerging technologies for the controlled release of these chemicals have captured considerable interest among petroleum engineers. Microencapsulation, a method widely employed for controlled release in various industries such as biotechnology, pharmaceuticals, and agriculture, is gaining traction in the realm of oil and gas exploitation. This paper provides a comprehensive review of encapsulation technologies, including solvent evaporation, coacervation, and polymerization methods. Special emphasis is placed on recent advancements in the applications of microcapsules within the oil and gas sector. Given the profound impact of release behavior …

Application Of Electrical Impedance Tomography To Cementitious Composites, Hugo Zazueta

Theses and Dissertations

This thesis explores the feasibility of using Electrical Impedance Tomography (EIT) for detecting damage in cementitious composites. Cementitious composites, such as concrete and cement mortar, are insulating; any conductive properties arise from the moisture within their pores and capillary structures. The proposed concept herein is that formed internal damages in cementitious composites consequently alter their pore and capillary structure, which can then be detected through EIT imaging. To construct tomographic images, the Gaussian Newton (GN) reconstruction algorithm, enhanced with priors, was employed. The results were then compared across different reconstruction processes. Cylindrical cement pastes and cement mortar samples were prepared, …

Nonplanar Robotic Printing Of Earth-Based Material: A Case Study Using Cob-Like Mixture, Lina Ahmad, Wassim Jabi, Marco Sosa

All Works

The study presents an integration of cob with robotic processes. By challenging conventional monolithic earth-building methods, the study proposes the use of spatial nonplanar formations that are robotically fabricated, presenting an alternative geometric language for earth construction. The research methodology is derived from existing factors within the robotic lab, encompassing both constant and variable parameters. Through an experimental approach, the variables are systematically manipulated while observing the outcomes to identify patterns and relationships. Incremental refinements to the research conditions result in an optimal equilibrium state within the defined lab parameters. An empirical investigation approach serves as the foundation for controlling …

Cubic Soft Ideals On B-Algebra For Solving Complex Problems: Trend Analysis, Proofs, Improvements, And Applications, Muhammad Saeed, Hafiz Inam Ul Haq, Mubashir Ali

Neutrosophic Systems with Applications

In this paper, we introduce the concepts of cubic soft (CS) algebra, CS o-subalgebra, and CS ideals within the framework of B-algebra. We provide comprehensive characterizations of these new structures, elucidating their unique properties and interrelationships. Specifically, we present detailed conditions under which a CS subalgebra can be classified as a closed CS ideal. Our analysis explores the intricate relationships among closed cubic soft ideals, cubic soft subalgebras, and cubic soft o-subalgebras. By doing so, we aim to provide a deeper understanding of how these structures interact and coexist within the broader context of B-algebra The findings offer significant insights …

Trip Production Models For Persons With Disabilities, Pouyan Saeidian

All Graduate Theses and Dissertations, Fall 2023 to Present

Nearly 13% of the US population consists of people with disabilities, yet finding an equitable and comprehensive approach to meet their travel needs remains a challenge. Our research delves into the mobility patterns of people with disabilities to understand how their daily travel—both the frequency of trips and the distance covered—compares to those without disabilities. We also explore the factors influencing their travel behaviors and how these insights can guide policymakers in improving accessibility and mobility for this community. Utilizing data from the 2022 US National Household Travel Survey, we applied a blend of statistical analysis and machine learning methods. …

Developing A Comprehensive Genome-Scale Metabolic Model For The Arabidopsis Thaliana Root System, Lohani Esterhuizen

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Arabidopsis thaliana (Arabidopsis) is the most well-established model plant to date. Being the first plant to have its genome mapped, studies on Arabidopsis have provided insurmountable insights into the physiological and biochemical nature of plants. Methods that allow us to computationally study the metabolism of organisms include the use of genome-scale metabolic models (GEMs). Despite its popularity, no GEM currently maps the metabolic activity in the root system of Arabidopsis, which is the first organ to face and respond to stress conditions in the soil. This work aims to develop and implement a comprehensive GEM of the Arabidopsis root system …

Evaluation Of Unreinforced And Geosynthetic-Reinforced Subgrade Material Performance With Large-Scale Tracking Wheel Tests And Dynamic Cone Penetrometer Tests, Kenaz Owusu

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Subgrade has a significant impact on the performance of a pavement as it serves as the foundation layer on which traffic loads are transferred. Many pavement failures can be attributed to weak subgrade strength. The integration of geosynthetics in road pavements has been identified as an effective solution for enhancing subgrade performance to withstand imposed traffic. This study evaluated the performance of unreinforced and geosynthetic-reinforced subgrades in Nebraska to quantify the contribution of geosynthetics to unpaved layer systems.

The strength and stiffness of different soil subgrades were assessed through unconfined compressive strength tests and repeated load triaxial (RLT) tests, which …

Smart Automatic Modal Hammer Predictor–Corrector Approach For Accurate Excitation Of Dynamical Systems, Mohammad Nasr

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

This research introduces an innovative solution that revolutionizes the study of linear and nonlinear dynamical systems—a smart automatic modal hammer. With its affordability and intelligent capabilities, this automatic modal hammer becomes an invaluable tool for research and industry, enabling repeatable strikes with precise force control. This system's significance becomes particularly evident when studying nonlinear systems, which heavily rely on the excitation level for their dynamics. By offering a cost-effective design this proposed system proves to be robust in accelerating research on nonlinear dynamics, providing researchers with an efficient and accessible means to delve deeper into these complex systems. The proposed …

Ultrasonic Nondestructive Quantification Of Case Depth In Railroad Bearing Components, Trevor K. Adelung

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

While in service, railroad bearings must withstand large loads to ensure smooth operation. These large loads can lead to failure due to rolling contact fatigue (RCF), for which small cracks initiate just beneath the surface of the components. As a preventative measure, bearings are manufactured with a hardened surface layer called the effective case depth (ECD). Current methods in industry use destructive hardness testing to quantify the ECD. While accurate, this method is costly and time consuming. Ultrasonic nondestructive testing would provide a more efficient and cost-effective method to determine ECD. In this thesis, diffuse ultrasonic shear backscatter was used …

Studies Of Exotic Electronic, Optical, And Electrochemical Properties In Nanoparticle Assembly And Graphene, Jay Min Lim

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

It is well known that exotic properties and phenomena emerge as structural dimensions shrink to nanoscales. We self-assembled one-dimensional chains of gold nanoparticles in solution and quantified the growth process by monitoring the redshift of localized surface plasmon resonance (LSPR). Curiously, the redshift stopped while the chains continued to rearrange as manifested by gradual reduction in the LSPR peak. Using electromagnetic simulations, we quantitatively explained the phenomena as a rapid “addition-polymerization” followed by a sharp transition to “condensation-process.” Next, recognizing the significant electric field enhancement in the interparticle gap, a photoluminescent-active Eu³⁺ ion was used to probe Surface-Enhanced Photoluminescence …

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 …

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 …

Modeling, Optimization, And Characterization For Choke Horn Antennas, Ibrahim Nasser I Alquaydheb

Graduate Theses and Dissertations

This dissertation presents a comprehensive study focusing on the modeling, optimization, and characterization of choke horn antennas (CHAs). An analytical model designed to capture the parameters of CHA and derive the total radiated fields from the choke and waveguide elements is primarily focused on in this work. Compared to the use of simulation software, such as ANSYS HFSS (High Frequency Structure Simulator) or CST Studio, which employs numerical methods to simulate and calculate antenna performance, numerous advantages are offered by the analytical model. Analytical models provide deeper insight into electromagnetic interactions and the principles governing antenna behavior, leading to a …

Optimization Of And Mechanistic Insights Into Photocatalytic And Non-Thermal Plasma Degradation Of Organic Pollutants For Sustainable Wastewater Treatment, Yiting Xiao

Graduate Theses and Dissertations

Water pollution by organic pollutants poses a significant environmental threat, necessitating the development of advanced treatment technologies to ensure sustainable and efficient remediation. This dissertation explored innovative approaches to enhance the degradation of organic pollutants through the integration of photocatalytic and plasma-assisted systems, with a focus on optimizing these processes using methodologies ranging from response surface methodology (RSM) to advanced machine learning techniques. The first part of the dissertation investigated the degradation of organic pollutants in flocculated liquid digestate using photocatalytic titanate nanofibers (TNFs) synthesized via a hydrothermal method. This study represents the first application of TNFs, with a bandgap …

Leveraging Machine Learning And Stochastic Programming To Address Vaccine Hesitancy In Public Health Resource Allocation, Hieu Trung Bui

Graduate Theses and Dissertations

Infectious disease outbreaks highlight the urgent need for effective strategies to distribute vaccines and allocate critical healthcare resources to contain the disease and reduce its negative impacts on the population. Managing these allocations is a significant challenge, especially in marginalized communities facing uncertainty in healthcare demand and logistical constraints. This dissertation addresses these challenges by investigating factors that influence dynamic changes in vaccine hesitancy (VH) and its implications for disease spread and healthcare resource demand. It develops optimization models for vaccine distribution and resource allocation under uncertainty, validated with data from the COVID-19 pandemic in the U.S. The first study …

Time-To-Failure Prediction Of Fine-Grained Soil Slopes Subject To Weather-Driven Deterioration, Arm M. Morsy

Mineta Transportation Institute

Embankments have been widely used in the construction of transportation and flood defense infrastructure. Embankments constructed from clays experience a suite of weather-driven deterioration processes that lead to a progressive loss of hydromechanical performance, causing potentially severe and costly consequences. This study aimed to predict the time to failure of aging, deteriorating clay embankments supporting transportation infrastructure. A multi-phase numerical modeling approach was developed to replicate the long-term, weather-driven, hydromechanical behavior of clay embankments. This model simulated the behavior of a number of well-documented embankment failure case studies that had sufficient data to derive the necessary soil properties and climate …

Enabling Sustainable Freight Forwarding Network Via Collaborative Games, Pang Jin Tan, Shih-Fen Cheng, Richard Chen

Research Collection School Of Computing and Information Systems

Freight forwarding plays a crucial role in facilitating global trade and logistics. However, as the freight forwarding market is extremely fragmented, freight forwarders often face the issue of not being able to fill the available shipping capacity. This recurrent issue motivates the creation of various freight forwarding networks that aim at exchanging capacities and demands so that the resource utilization of individual freight forwarders can be maximized. In this paper, we focus on how to design such a collaborative network based on collaborative game theory, with the Shapley value representing a fair scheme for profit sharing. Noting that the exact …

Fuel-Saving Route Planning With Data-Driven And Learning-Based Approaches: A Systematic Solution For Harbor Tugs, Shengming Wang, Xiaocai Zhang, Jing Li, Xiaoyang Wei, Hoong Chuin Lau, Bing Tian Dai, Binbin Huang Huang, Zhe Xiao, Xiuju Fu, Zheng Qin

Research Collection School Of Computing and Information Systems

In recent years, there are trends toward cleaner port environments through enforcement by imposed legislation. Transit optimisation of fuel-based port service boats like harbour tugs has emerged as a critical task to reduce fuel consumption and carbon emission. In this paper, an innovative learning-based method, comprising a Reinforcement Learning (RL) model together with a fuel consumption prediction model, was proposed to formulate fuel-saving transit routes. Firstly, an ensemble model is established by combining a Long Short-Term Memory (LSTM) model with a Multilayer Perceptron (MLP) model, predicting fuel use based on tugboat movement and environment factors. Subsequently, an innovative RL based …

A Broadband, Dual Polarized Antenna For The Radio Neutrino Observatory In Greenland, Danny Maas

Master's Theses

The Radio Neutrino Observatory in Greenland (RNO-G) is a multidisciplinary, multinational collaboration which uses antennas to detect neutrino interactions with arctic ice sheets. Neutrinos are formed from nuclear reactions; predominant sources include nuclear reactors, stars, supernovae, and the big bang. They rarely interact with normal matter and thus travel from origin to destination relatively unimpeded, with applications including tracking nuclear weapons tests and supernovae. Measurements of galactic neutrino flux can provide information about how the universe developed and its current evolution. Neutrino interactions produce signals from 100 to 1000MHz. Current RNO-G antennas operate over only a portion of this band; …

Penetration Thresholds Of Porcine Limbs For Low Sectional Density Projectiles In High-Rate Impact, Joseph Lesueur, Jared Michael Koser, Carolyn E. Hampton, Michael Kleinberger, Frank A. Pintar

Biomedical Engineering Faculty Research and Publications

Introduction

With similar prevalence to injuries from fires, stings, and natural disasters, soft tissue injuries may occur from fireworks, industrial accidents, or other explosives. Surgeons are less familiar with treating high-velocity penetration from small debris, which may increase the chance of infection and subsequent fatality. Penetration risk curves have been developed to predict V₅₀, the velocity with 50% probability of penetration, for various sized projectiles. However, there has been limited research using nonmetallic materials to achieve lower density projectiles less than 1 g cm−2, such as sand or rocks.

Material and Methods

To emulate the size and density …

Transient Heat Transfer To Rolling Or Sliding Drops On Inclined Heated Superhydrophobic Surfaces, Joseph Furner, Daniel Maynes, Brian D. Iverson, Julie Crockett

Faculty Publications

The thermal transport to drops that roll or slide down heated superhydrophobic surfaces is explored. High-speed infrared imaging is performed to provide time-resolved measurement of the heat transfer to the drop. Data are obtained for drops moving along smooth hydrophobic and structured superhydrophobic surfaces. Both post and rib style structures with surface solid fractions ranging from 0.06 to 1.0 are considered. The inclination angle of the surfaces was varied from 10 deg to 25 deg, and the drop volume was varied from 12 to 40 µL. The measurements reveal that the drop speed is a strong function of both the …

Magnetic Sensor Compensation Utilizing Factor Graph Estimation, Frederic W. Lathrop, Clark N. Taylor, Aaron Nielsen

Faculty Publications

Recently, there has been significant interest in the ability to navigate without GPS using the magnetic anomaly field of the Earth (magnav). One of the key technical bottlenecks to achieving magnav is obtaining an accurate magnetic sensor calibration, taking into account own-ship and sensor effects. The Tolles-Lawson magnetic calibration method continues to be the industry standard and was developed when airborne magnetic survey aircraft were first employed over 70 years ago. In this paper, we present a magnetic calibration algorithm based on a factor graph optimization using inertial measurements as well as inputs from both a vector and scalar magnetometer. …