Engineering Commons^™

Defining And Labeling Traversable Space In A Forested Environment, James Nguyen

All Theses

This thesis investigates the problem of identifying traversable terrain in outdoor conditions. We are motivated by research in recent years toward identifying drivable space for the purpose of developing autonomous vehicles. Our motivating application is similar but also different. We envision a “Hiker Helper” that assists humans with dismounted navigation in forested terrain. A common challenge in this type of environment is identifying a viable path for moving through terrain that is congested with trees, bushes, other flora, and natural obstacles that would make navigation difficult. We envision training an artificial intelligence (AI) model to automatically analyze images of this …

Improved Ballistic Impact Resistance Of Nanofibrillar Cellulose Films With Discontinuous Fibrous Bouligand Architecture, Colby Caviness

All Theses

Natural protective materials offer unparalleled solutions for impact-resistant material designs that are simultaneously lightweight, strong, and tough. Particularly, the dactyl club of mantis shrimp features chitin nanofibrils organized in a Bouligand structure, which has been shown to effectively dissipate high-impact energy during powerful strikes. The mollusk shells also achieve excellent mechanical strength, toughness, and impact resistance with a staggered, layer-by-layer structure. Previous studies have shown that hybrid designs, by combining different bioinspired microstructures, can lead to enhanced mechanical strength and energy dissipation capabilities. Nevertheless, it remains unknown whether combining Bouligand and staggered structures in nanofibrillar cellulose (NFC) films, forming a …

Development Of A Cost-Affordable Thin-Layer Chromatography Testing Kit For Falsified And Substandard Pharmaceuticals In Tanzania, Eleanor Hatcher

All Theses

A significant number of pharmaceuticals supplied to Tanzania are falsified or substandard. A majority of these inadequate pharmaceuticals are medications to treat life-threatening conditions. This problem not only causes mistrust in the healthcare system but also prolonged illness and potentially death for the patients. This calls for the need for the development of a cost-affordable testing kit for falsified and substandard pharmaceuticals in Tanzania. Thin-layer chromatography (TLC) was used as the testing method since it is inexpensive and requires a low skill level to complete. Malaria, human immunodeficiency virus, hypertension, tuberculosis, and diabetes are five of the most prevalent diseases …

Depression And Anxiety: Investigating The Impacts Of Scheduling On The Mental Health Of Healthcare Workers During The Covid-19 Pandemic, Christofer Gonzaga

All Theses

Depression is a growing problem in the United States and has ballooned into a globally recognized mental health issue that affects shift workers in various fields (Lee et al., 2017). Rates of depression and anxiety have been shown to be substantially increasing and the COVID-19 pandemic amplified this prevalence of depression and anxiety. In the United States, the prevalence of depression symptoms was more than 3- fold higher during COVID-19 compared to before the pandemic (Ettman et al., 2020). The delivery of healthcare services is an ongoing and dynamic process, requiring clinicians to work in various shifts to ensure the …

Phasor-Domain Short-Circuit Analysis Of Power Transmission Systems In The Presence Of Inverter-Based Resources, Dol Kunwar

All Theses

Although a power system is nonlinear during healthy operation because of constant power loads and controlled power injections from the sources, a conventional power system fed by synchronous generators is linear during fault, and can be represented by bus impedance matrix (Z-bus), which is useful in power system analyses such as short circuit (SC) analysis. However, With increasing penetration of inverter-based resources (IBRs) in the system, the assumption of linearity of the faulted network does not hold. This impacts the analyses relying on Z-bus and Thevenin’s equivalent impedance (TEI), such as certain protection schemes set using short circuit analysis. Therefore, …

Development And Evaluation Of An Arsenic Transport Model For The Maurice River Watershed, Christina Eddleman

All Theses

For many Superfund sites across the United States, arsenic is one of the most common contaminants of concern that must be cleaned up to protect human and environmental health. Past research and health studies have documented the harmful effects of inorganic arsenic on humans and the environment but selecting an appropriate remediation plan depends on several site-specific factors at each Superfund site. To assist in determining an appropriate remediation plan, sediment and contaminant transport models have been used to simulate the transport of arsenic and other contaminants of concern at contaminated sites to, e.g., make relative comparisons of the efficacy …

The Effect Of Football Facemask Design Variability On Dynamic Impact Performance And Quasi-Static Stiffness, Adam W. Smith

All Theses

This research addresses the role of facemasks in helmet systems, focusing on their dynamic impact performance and material properties. A total of 150 facemasks from 30 types and five helmets were tested both quasi-statically and dynamically. The facemasks were grouped by style and helmet type for comparison. Dynamic testing involved three different locations and two speeds, with data collected for maximum angular velocity and linear acceleration. Quasi-static stiffness, performed at two locations, was compared with collected dynamic results to determine the strength of relationship. A concussion metric, HARM, was calculated from collected data and compared across style groups.

Significant differences …

Multi-Domain Secure Dds Networks For Aerial And Ground Vehicle Communications, Daniel Pendleton

All Theses

none

Environment And Response Of 3d-Encapsulated Mesenchymal Stem Cells To Mechanical Loading, Augustus Greenwood

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis explores the micromechanical environment induced when cyclically compressing hydrogels via finite element modeling and experimentally on the impact of loading on mesenchymal stem cells (MSCs) when encapsulated withing 3D hydrogel matrices. Degenerative joint diseases, characterized by cartilage degradation, present significant challenges due to cartilage's limited self-repair capacity. Innovative approaches, including stem cell-based therapies and engineered biomaterials, have emerged as promising strategies for cartilage repair and regeneration. This work specifically investigates the calibration of a bioreactor, the uniformity of load response across the hydrogel constructs via finite element modeling (FEM), and the stress response of MSCs subjected to various …

The Importance Of Data Preparation In A Data Science Problem, Sophia Beard

Data Science Undergraduate Honors Theses

This study is going to be based on an inventory outlier automation data science problem that is being solved to identify and prescribe inventory level outliers to help keep shelves stocked in terms of beverages. The objective of this paper will address why it is so important to understand the data that is involved in a particular data science problem and how planning ahead ensures a successful outcome in the data science world. In this data science project, Spatiotemporal Outlier Analysis for Inventory Intervention Automation, it was crucial for the team to understand, research, and visualize the data we were …

Effects Of Process-Induced Defects On The Corrosion Of Additively Manufactured Stainless Steel 304l, Leila Saberi, Frank W. Liou, Mehdi Amiri

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This Study Investigates the Impact of Process-Induced Defects Such as Gas Pores, Lack of Fusions, and Surface Roughness on Corrosion Behavior of Stainless Steel 304L (SS304L) Fabricated by Laser Powder Bed Fusion Additive Manufacturing. Specimens Are Printed with Optimized Process Parameters but Selected from Different Locations on the Build Plate. Parallel and Perpendicular Surfaces to the Build Direction Are Investigated and Compared with Corrosion Properties of Wrought SS304L in 5 Wt% NaCl. the Results Reveal Significant Difference in Corrosion Behavior among Specimens Due to Variations in their Defect Features. Pitting Potential, Pit Initiation, and Growth Rates Are Found to Be …

Effect Of Pre-Heating On Residual Stresses And Deformation In Laser-Based Directed Energy Deposition Repair: A Comparative Analysis, Usman Tariq, Sung Heng Wu, Muhammad Arif Mahmood, Michael M. Woodworth, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser-Directed Energy Deposition (DED), a Metal Additive Manufacturing Method, is Renowned for its Role in Repairing Parts, Particularly When Replacement Costs Are Prohibitive. Ensuring that Repaired Parts Avoid Residual Stresses and Deformation is Crucial for Maintaining Functional Integrity. This Study Conducts Experimental and Numerical Analyses on Trapezoidal Shape Repairs, Validating Both the Thermal and Mechanical Models with Experimental Results. Additionally, the Study Presents a Methodology for Creating a Toolpath Applicable to Both the DED Process and Abaqus CAE Software. the Findings Indicate that Employing a Pre-Heating Strategy Can Reduce Residual Stresses by over 70% Compared to No Pre-Heating. However, Pre-Heating …

Effect Of Patient Specific Blood Biomarkers On Nanoparticle - Cell Interactions, Veronica Gabriela Contreras

Open Access Theses & Dissertations

Nanoparticles are currently known to be a promising material class for bio-applications in drug delivery and vaccine development. Using gold nanoparticles of varied sizes, in this case 45 and 100 nanometers as a model nanomaterial system, we investigated how patients' blood physiology and chemistry (such as solute, protein, lipid levels) affect the biological response to bionanomaterials. When nanoparticles are injected into the body, biomolecules in the blood adsorb to the nanoparticle's surface to form a biomolecular corona that is specific to the patient's unique blood composition. This biomolecular corona is important because it affects the in vivo fate and biodistribution …

Earth Abundant Catalyst For Evironmental Sustainability Applications, Javier Hernandez

Open Access Theses & Dissertations

The development of experimental methodologies for synthesizing a diverse range of metallic and metal oxide nanoparticles tailored for sustainable water treatment applications was investigated. These nanoparticles are prepared using environmentally friendly and scalable synthesis methods, underscoring their potential for large-scale production. Synthesized nanoparticles are harnessed for various processes, including catalysis and electrocatalysis, with a primary objective of degrading and removing organic pollutants from water. Key to this research is the encapsulation of nanoparticles within solid supports. Multiple methodologies are explored to engineer supports that ensure nanoparticle stabilization, monodispersion, and prevent unintended release into the environment. Two alternative approaches were evaluated …

Routing Opportunities For Commercial Crossings Between El Paso And Juarez, Marek Musil

Open Access Theses & Dissertations

This thesis explores the topic of commercial movements between the El Paso and Ciudad Juarez road networks and the implications of the possible changes in their routing. This area houses several ports of entry, which present one of the busiest commercial and personal border crossings in the whole nation. The primary focus was to evaluate the recently proposed reconstruction scenario of removing trucks from the Bridge of the Americas and study the impacts on the flows throughout the other ports. The chosen tool to support the analysis is a mesoscopic simulation software called DynusT, which is capable of modeling the …

Mav Localization In Gps-Denied Environments And Synthetic Data Collection In Challenging Simulated Conditions, Julio A. Reyes Munoz

Open Access Theses & Dissertations

The development of unmanned aerial systems presents an opportunity for conducting industrial inspections in environments where traditional navigation systems, such as the Global Navigation Satellite System (GNSS), are compromised. This dissertation investigates the implementation of a micro aerial vehicle (MAV) capable of autonomous data acquisition in complex, GNSS-degraded industrial settings. The primary challenge addressed is the robust localization of MAVs, a critical aspect in ensuring reliable operation under varying and uncertain environmental conditions.

The work is divided into two main parts. The first part focuses on the design and integration of a MAV system specifically for power plant inspections in …

Smart Public Transportation And Mobility Hub Design In El Paso, Jiri Vojtisek

Open Access Theses & Dissertations

This thesis explores the potential of a Smart Public Transportation concept and mobility hub design as tools to mitigate the growing trend of transportation issues, such as traffic congestion, reliance on privately owned vehicles, or unattractive public transportation. Consequently, residentsâ?? lives are negatively affected by excessive noise, air pollution, and travel delays, leading to increased safety risks, lost productivity, and a lower quality of life. Considering these challenges, the study begins by analyzing the current state of public transportation in El Paso. Next, it introduces a toolkit from the Smart City concept, followed by case studies of best practices of …

Summonable Construction Delivery Robot, Kevin M. Lewis

Honors Capstones

In many different construction industries, there is a need for tools, parts, and other necessary items to be transported quickly and efficiently over various types of terrain. Human resources have often been used to address these needs, which can become very time and cost inefficient over long periods. The design proposal here is aimed at addressing this need by developing an autonomous outdoor mobile robot based on a quadrupedal robot design. This approach differs by incorporating a wheeled and quadrupedal hybrid actuation system that provides terrain negotiation and speed at the appropriate times. The team uses Robot Operating System (ROS) …

Great South Metals: Slitter Head Building Process, Nabhan Karim, Evan Swierski, Raven Morin, Patrick Kelsey, Michael Williams

Senior Design Project For Engineers

Great South Metals (GSM) operates two steel slitter machines, which take large coils of flat rolled steel and cut them into smaller strips for use in customers’ applications. Setting up the working components of each machine, called the slitter head, is a precise and arduous task. This system relies on several manually performed calculations and acute attention to detail; and thus, is prone to human error. The management at GSM commissioned our team to simplify the slitter head assembly process by creating an automated computer program and make additional recommendations to improve their operations.

The program we created is a …

Multilayer Shielding Design And Analysis Of Optimal Thickness For The Storage Of Highly Radioactive Sources Concerning Environmental Safety, Md. Mahfuzul Haque Rafi, Asma Ul Husna, Abdus Sattar Mollah

International Journal of Nuclear Security

As a kind of radiological protection, multilayer shielding is superior to a single-layer shield in terms of blocking off radiation. This study examined a multilayer shielding strategy to protect employees from potentially harmful gamma radiation from highly radioactive sources such as ⁶⁰Co. This paper presents a novel strategy for cost-effective and environmentally safe radiation protection by aligning expensive and heavy materials such as W and Pb to improve their effectiveness and limit exposure below the occupational dose. The largely unpublished set of final exposure rates for the W–Pb–Fe combination was calculated by the numerical interpolation method in MATLAB software. …

Safety And Security Analysis Of Vver-1200 Reactor Pressure Vessel Under Pressurized Thermal Shock, Mohammed Sarim Salman Karim, Dr. Debashis Datta, Altab Hossain

International Journal of Nuclear Security

The reactor pressure vessel (RPV) is an important component of a nuclear power plant and of great concern to safety and security globally. Thus, the thermal system of an RPV should be ensured properly through an evaluation system that closely monitors and considers its integrity. This article describes the thermomechanical analyses for a pressurized thermal shock (PTS) scenario of a VVER-1200 RPV owing to a loss of coolant accident (LOCA) and activation of the emergency core cooling system (ECCS). The LOCA transient and activation of ECCS are modeled using ANSYS simulation software. From the analyses of the emergency core cooling …

Design And Development Of A Radiation Survey And Rescue Robot With Shielding Of Electronic Equipment From Radiation Damage With Image Radiation Mapping Facility, Md. Sifatul Muktadir, Md. Nazmul Hassan, Md. Saimon Siddique, Dewan Nazmun Nur, Altab Hossain, Ahnaf Tahmid Chowdhury

International Journal of Nuclear Security

The use of remote-controlled robots in emergency fields is a necessary requirement at present, which includes the nuclear engineering field because the radioactive environment creates adverse effects on human health. This work describes the development of a remotely controlled rover capable of detecting ionizing radiation, isolating radiation sources using a robotic arm, and sufficient shielding for its internal components. A custom-made Geiger–Muller counter has been used to detect ionizing radiation. The radioactive environment is not only harmful for humans but also can cause severe damage to the electronic circuit mounted on the robot. Therefore, a custom concrete material sandwiched between …

A Review And Analysis Of Nuclear Hydrogen Production In Generation Iv Reactors, Arijit Saha Ayon, Ashiqur Rahman Alif, A. S. M. Nasim

International Journal of Nuclear Security

Hydrogen is becoming increasingly vital as a chemical element in the progress of human civilization. Hydrogen finds application in the creation of ammonia, the manufacturing of nitrogen-based fertilizers, and a wide range of organic compounds, including methanol and propulsion fuel for space exploration missions. Additionally, there are ongoing experiments in the automotive industry to harness hydrogen-based fuel cells as an alternative power source. In modern technology, multiple methods and strategies for hydrogen production originate from diverse sources, such as fossil fuels, renewable energy, nuclear energy, and more. Generation IV nuclear reactors significantly affect the production of hydrogen. These reactors operate …

Bim Coordination Post Pandemic, Zachary Marshall

Honors Scholar Theses

The goal of this thesis is to utilize previous research done on virtual meetings and build upon it by conducting new research on the successes and failures of current virtual BIM meetings. This paper starts with a literature review looking into Building Information Modeling (BIM) Coordination and the effects the COVID-19 pandemic has had on the BIM meetings. BIM meetings started to shift virtual due to the nature of the pandemic and this has had effects on the performance and structure of the coordination. This knowledge was then expanded on by looking at virtual BIM meeting case studies. Interviews were …

Diegetic Sonification For Low Vision Gamers, Jhané Dawes

Master's Theses

There are not many games designed for all players that provide accommodations for low vision users. This means that low vision users may not get to engage with the gaming community in the same way as their sighted peers. In this thesis, I explore how diegetic sonification can be used as a tool to support these low vision gamers in the typical gaming environment. I asked low vision players to engage with a prototype game level with two diegetic sonification techniques applied, without the use of their corrective lenses. I found that participants had more enjoyment and experienced less difficulty …

Cooperative And Bifunctional Adsorbent-Catalyst Materials For In-Situ Vocs Capture-Conversion, Sukanta K. Mondal, Peter Aina, Ali A. Rownaghi, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

Volatile Organic Compounds (VOCs) Are Gases that Are Emitted into the Air from Products or Processes and Are Major Components of Air Pollution that Significantly Deteriorate Air Quality and Seriously Affect Human Health. Different Types of Metals, Metal Oxides, Mixed-Metal Oxides, Polymers, Activated Carbons, Zeolites, Metal-Organic Frameworks (MOFs) and Mixed-Matrixed Materials Have Been Developed and Used as Adsorbent or Catalyst for Diversified VOCs Detection, Removal, and Destruction. in This Comprehensive Review, We First Discuss the General Classification of VOCs Removal Materials and Processes and Outline the Historical Development of Bifunctional and Cooperative Adsorbent-Catalyst Materials for the Removal of VOCs from …

Future Of Process Safety: Insights, Approaches, And Potential Developments, Hossein Abedsoltan, Amirhesam Abedsoltan, Zeinab Zoghi

Chemical and Biochemical Engineering Faculty Research & Creative Works

This review explores the evolving landscape of process safety, emphasizing the integration of digitalization and advanced technologies. It assesses the role of the industrial Internet of Things, artificial intelligence, and machine learning (ML) in enhancing safety protocols. The paper examines predictive analytics, sensor technology advancements, and digital twins' contributions to safety optimization. It also discusses the future perspectives of risk management approaches, including proactive safety management systems, quantitative risk assessment techniques, and human reliability analysis. This comprehensive analysis provides insights into future developments and challenges in process safety.

Spatial Hearing In Simulated Reverberant Classroom Environments, Gabriel Seth Evan Weeldreyer

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Spatial hearing provides access to auditory spatial cues that promote speech perception in noisy listening situations. However, reverberation degrades auditory spatial cues and limits listeners’ ability to utilize these cues for segregating target speech from competing babble. Hence, spatial unmasking—an intelligibility benefit from a spatial separation between a target and masker—is reduced in reverberant environments as compared to free field. This work tests the hypothesis that interaural decorrelation, the result of increasing reverberation, will broaden the perceived auditory source width with a cascading effect of reduced auditory spatial acuity and subsequently poorer spatial unmasking. To understand the perceptual consequences of …

Next-Generation Crop Monitoring Technologies: Case Studies About Edge Image Processing For Crop Monitoring And Soil Water Property Modeling Via Above-Ground Sensors, Nipuna Chamara

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

Artificial Intelligence (AI) has advanced rapidly in the past two decades. Internet of Things (IoT) technology has advanced rapidly during the last decade. Merging these two technologies has immense potential in several industries, including agriculture.

We have identified several research gaps in utilizing IoT technology in agriculture. One problem was the digital divide between rural, unconnected, or limited connected areas and urban areas for utilizing images for decision-making, which has advanced with the growth of AI. Another area for improvement was the farmers' demotivation to use in-situ soil moisture sensors for irrigation decision-making due to inherited installation difficulties. As Nebraska …

Mechanical Engineering Capstone: A Reflection On The Design And Prototyping Of A Portable Water Heating System, Timothy Goldsmith

Honors Program: Senior Projects (Public)

This thesis includes several documents from a Mechanical Engineering Capstone course. These include project postmortem reports written at the conclusion of each term. These reports summarize the designing and prototyping of a portable water heating system. Additionally, this thesis includes written feedback on the final presentations for six other senior design teams. In these documents, presentations and projects are evaluated and encouragement and feedback are provided for the teams. The final component of this thesis is an essay reflecting on the different leadership roles assumed during the capstone course.