Engineering Commons^™

Analyzing Tms 402 -22 : Design Of Special Reinforced Masonry Shear Walls, Tristan D. Aranda

Architectural Engineering

This experiment examines possible inconsistencies in the TMS 402-22 masonry code between Section 7.3.2.5 and Section 9.3.5.6.2, regarding the requirements for special boundary elements in Special Reinforced Masonry Shear Walls. By investigating the two sections, it can be determined whether the two sections are in accordance with each other regarding aspect ratio. Tensile forces and strains are calculated respectively for each wall and block type and are compared to the respective tensile yield forces and ductile strains. This determines which respective boundary elements go past yield and become ductile. Based on this determination, recommendations can be made to the …

Using Nano-Ities For Detection Of Metal Ions In Complex Aqueous Solutions, Mohammed Muzammil Nishar Ahmed

Theses and Dissertations

Recent urbanization has induced a rapid increase in heavy metal exposure to humans. The exploitation of heavy metals for economic gains coupled with poor and economically infeasible recycling methods have led to poor management of heavy metal wastes, which has opened up several pathways for heavy metals to enter the human body. Such heavy metals target many vital organs, but the early symptoms are common and difficult to diagnose. Severe symptoms appear in later stages and are very expensive to treat and the damage caused to the health are not typically reversable in such later stages. To counter this issue, …

Two-Photon Imaging For Characterizing Tumor Microenvironmental Changes In Non-Small Cell Lung Cancer Associated With Metastatic Recurrence, Paola Monterroso Diaz

Graduate Theses and Dissertations

Lung cancer remains the leading cause of cancer deaths, comprising nearly 25% of all cancer deaths (Sung et al., 2021a). The five-year survival rate of patients with non-small cell lung carcinoma (NSCLC) remains significantly low given that over half present with locally advanced or metastatic disease at time of diagnosis, and experience tumor recurrence following therapeutic intervention (Tamura et al., 2015; Uramoto & Tanaka, 2014). Current evaluation techniques to assess treatment response are lacking, given they are implemented several weeks after treatment completion and are solely based on anatomical changes in tumor size, forgoing other criteria such as functional or …

Mechanical Stress In Solar Cells: Beyond The Sun's Light, Md Motinu Rahman

Engineering Graduate Student 3MT

The average lifespan of a solar panel is typically 20-25 years, often limited by thermal mechanical stress caused by daily and seasonal temperature changes. These stresses create microcracks, leading to reduced efficiency and eventual failure. To address this, integrating stress and temperature sensors within solar panels can monitor and manage stress through a water-cooling system. The sensors are connected to the cloud through ThingSpeak, where data analysis is performed, and the entire system is integrated with a DC microgrid. A MATLAB algorithm, developed using reinforcement learning, manages the load and solar panel operation. This approach can potentially double the lifespan …

Assessing Reproducibility Challenges In Clinical Metabolics, Darcy Lin Cochran

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

Current metabolomics research is expanding to be multiplatform and interdisciplinary. Metabolomic analysis has the potential to provide detailed insight into any biological system of interest to analyze the underlying molecular mechanisms of variables like environment, disease, and genetics. Human clinical metabolomics is a major research area that is often focused on finding biomarkers or panels of biomarkers for different diseases. However, results are difficult to compare across different laboratories since the field of metabolomics has yet to widely adopt best practices for sample preparation, data acquisition and data processing, results are difficult to compare across different laboratories.

This thesis focuses …

Controller Software: Evolution, Identification, And Implementation, Balaji Balasubramaniam

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

In the annals of automation history and advancement, one can find control technology is at the core. Modern-day controllers rely heavily on software capability to provide stability and improve the system's performance. In particular, drone flight controllers use autopilot control software to accomplish autonomous navigation from take-off to landing. However, we know very little about how the controller code modifications and its impact, particularly at the software level. No general framework has been developed to identify the control code changes and observe the real values of software control loops at the kernel layer.

In this thesis, we lay the foundation …

Deep Learning Vision-Based Bridge Inspection With Resource-Constrained Unmanned Aircraft Systems, Ji Young Lee

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

Bridge inspection is critical for ensuring structural integrity, extending the service life of infrastructure, and minimizing maintenance costs. As bridges age and endure increasing loads, regular inspections help detect early signs of wear, such as cracks or corrosion, that could impact safety and performance. However, traditional inspection methods are labor-intensive, requiring significant time, specialized equipment, and manual access to challenging areas, which can lead to costly disruptions. Additionally, reliance on human inspectors introduces subjectivity, with assessments varying by individual expertise. These factors highlight the inefficiencies and safety risks in current inspection practices, underscoring the need for more objective, efficient solutions. …

The Use Of Two-Dimensional Detectors For Snapshot And High Accuracy Imaging Ellipsometry, Jeremy A. Vanderslice

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

Ellipsometry is a powerful and sensitive optical technique used to characterize thin film thickness and optical properties by measuring changes in the polarization state of light upon reflection or transmission. This dissertation investigates novel ellipsometry configurations that use two-dimensional detectors to enhance measurement speed, spatial resolution, or accuracy of ellipsometry measurements. The study involves the development of three different ellipsometry configurations, encompassing mechanical prototypes, mathematical models, and test measurements to evaluate each system.

Advisor: Jeffrey Shield

Channel Estimation In Millimeter Wave Mimo Systems: The Tensor-Based Methods, Fei He

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

This dissertation presents two novel tensor-based methods for solving channel estimation (CE) problems in Millimeter Wave (mmWave) multiple-input multiple-output (MIMO) wireless communication systems. First, we proposed a method of tensor rank regularization with bias compensation for CE in a hybrid mmWave MIMO system. We modified the CANDECOMP/PARAFAC(CP) decomposition-based method and jointly estimated the tensor rank and channel factor matrices. It differs from most existing works by assuming that the number of channel paths is unknown, yet it can accurately estimate channel parameters without prior knowledge of the number of multipath components. The tensor rank is estimated by a novel sparsity-promoting …

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 …

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 …

Dynamic Optimization Of Directed Energy Deposition Build Conditions Using Real-Time Monitoring Via Closed-Loop Control, Callan Herberger

Open Access Theses & Dissertations

Directed Energy Deposition (DED) is an additive manufacturing process that is being rapidly adopted by industry and is well suited for the fabrication of complex components in various metal alloys. DED provides unique benefits such as design flexibility, the potential for in-situ alloying, and an open environment that allows for unobstructed monitoring within the build chamber. Despite these benefits, fully exploiting additive manufacturing's (AM) potential remains a complex task for designers. This dissertation presents a framework for controlling Directed Energy Deposition process variables through in-situ monitoring. An exploration into modifying AM build conditions through the development and implementation of a …

Uncovering The Light Network Load Performance Penalty Of The Network Link Outlier Factor (Nlof), Michelle Lara

Open Access Theses & Dissertations

This thesis evaluates the effectiveness of the Network Link Outlier Factor with Most Likely Link (NLOF: MLL) algorithm under varying network load conditions. Repeated simulation experiments using Mininet were conducted for four different network-wide load levels: 100 Mbps, 500 Mbps, 1 Gbps, and 5 Gbps. Using statistical inference, our experimental results indicate that NLOF: MLL is ineffective under light load conditions (i.e., 100Mbps load) due to the limited network flow data available for its learning process. This limitation highlights a key challenge in applying the algorithm to lightly loaded networks. A preliminary algorithm was proposed to address this light-load performance …

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 …

Monitoring Of Laser Soldering Process In Hybrid Additive Manufacturing, Alexander P. Pustinger

Open Access Theses & Dissertations

Additive manufacturing (AM) has been a maturing technology that has expanded over the course of the last decade in major advancements especially in accessibility, process monitoring, modeling, and stock material design. As its industry use is growing, the demand for added improvements such as multi-functionality increases, such as with a hybrid system that allows for modification of printed parts with different electrical components like the Foundry Multi-3D system. The system's purpose is to create AM parts with multifunctional electrical components with the vision to expand to other areas of interest in manufacturing such as ISAM. This work explores the use …

Computational Investigation Of Boundary-Layer Transition Mechanisms In A Blunt Cone, Arturo Rodriguez

Open Access Theses & Dissertations

In this study, we have performed two-dimensional steady-state hypersonic CFD and one-and-two-dimensional steady-state heat conduction numerical simulations. We are using them to guide and study hypersonic boundary-layer transition ground testing physical experiments to be performed at Holloman High-Speed Test Track. We use surface heat transfer and fluid flow spot signatures to identify fluid flow regimes using laminar and turbulent numerical simulation solvers to understand boundary-layer transition thermocouple temperatures and fluid flow-forming structures. We have also analyzed the fluid flow in the geometries to be inviscid. We passed the CFD solution into the boundary-layer Harris code developed by NASA to explore …

Intrinsic, Doped And Alloyed Gallium Oxide Films For Optoelectronics, Francelia Sanchez Escobar

Open Access Theses & Dissertations

Due to the impressive advancement of present technology and increasing energy consumption, there is increasing demand for energy-efficient multifunctional devices based on low-cost, eco-friendly material systems. Gallium oxide (Ga2O3) is an emerging semiconductor with potential for the next generation of power electronics and optoelectronic devices due to its ultra-wide bandgap of 4.8 eV and high theoretical breakdown voltage of 8 MV/cm among other intrinsic properties. Some of the possible applications of β-Ga2O3 include ultra-violet (UV) solar blind photodetectors, field effect transistors, solar cells, and chemical sensors. However, to utilize its full potential, understanding the mechanistic aspects of thin film growth …

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 …

Optimal Route Planning Considering Microlevel Sequence Of Delivery Task Using Computer Simulation, Dana Alejandra Zamorano Orozco

Open Access Theses & Dissertations

As globalization reshapes our industries worldwide, supply chain management has evolved into a highly interconnected world that oversees traditional management, making countries more interdependent. Driven by rapid technological advancements, this shift allows companies to share information in a matter of seconds across continents, aligning operations and building adaptability to quick changes. Therefore, industries have greatly needed to adjust to and use the new technology to their advantage. However, even when this impact can be observed globally, the general impact can be analyzed and eradicated by performing micro-level analysis within the supply chain using technologies to their advantage. AnyLogic is a …

Advancing Grid Modernization Through Data-Driven Resilience Modeling And Hosting Capacity Of Distributed Energy Resources, Oscar Samuel Acosta

Open Access Theses & Dissertations

This Ph.D. dissertation focuses on advancing the integration of distributed energy resources (DERs) through concepts surrounding their impacts on power system stability, resilience, and hosting capacity (HC). This dissertation addresses crucial topics in renewable energy deployment, transient fault response, and dynamic modeling. The work begins with the development of renewable energy source (RES) models tailored for offsetting residential heating, ventilation, and air conditioning~(HVAC) and commercial cooling loads. These models utilize solar photovoltaic (PV) and wind energy systems to produce scalable frameworks adapted across diverse climates and building types in application of a partial-load targeting methodology. The dissertation then transitions from …

Microwave-Assisted Pyrolysis Of Hydrocarbons Using Iron-Based Alumina Catalysts Obtained Via Solution Combustion Synthesis, Zachary Aidan Chanoi

Open Access Theses & Dissertations

The demand for hydrogen is growing which makes the development of clean and efficient H2 synthesis technologies imperative. Microwave-assisted, thermocatalytic, dehydrogenation of hydrocarbons has demonstrated the ability to generate H2 with high yield/selectivity and leaving behind valuable solid carbon byproducts. However, this microwave-assisted process is unoptimized which prevents it from being utilized in industry. A critical component of optimization is the development of a catalyst that is catalytically active, a good microwave absorber, and can be regenerated for repeated dehydrogenation cycles. Previous studies that focused on plastic waste decomposition have used iron-based alumina (FeAlxOy) made via solution combustion synthesis (SCS). …

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 …

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.

Advancements In Polymer Synthesis And Ceramic Additive Manufacturing For Energy Applications, Sofia Gabriela Gomez

Open Access Theses & Dissertations

The aim of this work was to create polymer and ceramic materials for integration into energy applications. The first part of this research was to fabricate polymer syntactic foams that exhibited high energy absorption capabilities. The fabrication of polymer syntactic foams was feasible through synthesizing hollow polysiloxane microspheres that were imbedded into a polydimethylsiloxane (PDMS) matrix. An array of characterization techniques was used to test the material and physical properties of the syntactic foams. The next step of this research was to fabricate a porous water emulsion foam ink for use in Direct-Ink-Write (DIW) additive manufacturing (AM) technologies. Unlike the …

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 …

Cal Poly Gateway Decathlon Deliverable 3: Cost Estimate Development, Ruby Maria Sierra

Construction Management

The Gateway Decathlon is a global competition where university teams design, build, and operate sustainable, energy-efficient, and cost-effective homes using advanced technologies and materials. Teams create homes with renewable energy, energy-efficient systems, and sustainable materials. The competition evaluates design, energy efficiency, sustainability, and market viability. Currently, teams are working on Deliverable 3, which includes technical documentation, architectural plans, energy simulations, and cost analyses to ensure project feasibility. This deliverable bridges the design and construction phases and sets the foundation for building and operating the homes, helping to advance sustainable building practices and energy-efficient solutions.

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 …

Hafnium Oxide Coating To Improve The Oxidation Behavior Of Zirconium Diboride, Jan E. Förster, William G. Fahrenholtz, Gregory E. Hilmas, Ravisankar Naraparaju

Materials Science and Engineering Faculty Research & Creative Works

Hafnium dioxide (HfO₂) coatings were successfully deposited on zirconium diboride (ZrB₂) using reactive magnetron sputtering. After the oxidation at 1500°C or 1600°C, the mutual dissolution of HfO₂ and thermally grown ZrO₂ was observed which has resulted in the formation of a mixed oxide zone. As the enrichment of the mixed oxide zone by ZrO₂ progresses, monoclinic/tetragonal phase transition temperature of ∼1790°C for nominally pure HfO₂ moves towards ∼1500 °C. Finally, the inevitable phase transition from monoclinic to tetragonal structure results in the development of cracks, pores, and gaps within the mixed oxide …

Machine Learned Interatomic Potentials For Ternary Carbides Trained On The Aflow Database, Josiah Roberts, Biswas Rijal, Simon Divilov, Jon Paul Maria, William G. Fahrenholtz, Douglas E. Wolfe, Donald W. Brenner, Stefano Curtarolo, Eva Zurek

Materials Science and Engineering Faculty Research & Creative Works

Large-density functional theory (DFT) databases are a treasure trove of energies, forces, and stresses that can be used to train machine-learned interatomic potentials for atomistic modeling. Herein, we employ structural relaxations from the AFLOW database to train moment tensor potentials (MTPs) for four carbide systems: CHfTa, CHfZr, CMoW, and CTaTi. The resulting MTPs are used to relax ~6300 random symmetric structures and are subsequently improved via active learning to generate robust potentials (RP) that can relax a wide variety of structures, and accurate potentials (AP) designed for the relaxation of low-energy systems. This protocol is shown to yield convex hulls …