Engineering Commons^™

Multiscale Characterization Of Dislocation Development During Cyclic Bending Under Tension In Commercially Pure Titanium, Nathan R. Miller

Theses and Dissertations

Continuous bending under tension (CBT) has been shown to increase room temperature elongation-to-failure (ETF) in various sheet metals past that of simple tension (ST). In commercially pure titanium (CP-Ti) Grade 4, up to 3x extended elongation over ST has been achieved. A greater understanding of deformation mechanisms in CBT would allow for its elongation-enhancing effects to be more fully exploited in HCP and other metals, creating potential for new forming strategies. While most of the extended ETF has been attributed to delayed localization via incremental deformation inherent to the CBT process, together with compressive stabilization and relaxation of mechanical strain …

High Data Rate Signal Processing Architectures And Compilation Strategies For Scalable, Multi-Gigabit Digital Systems, Daniel Alexander Nybo

Theses and Dissertations

In this study we present a high-performance computing architecture and hardware acceleration strategy for a heterogeneous multi-gigabit computing system. The system architecture integrates a BeeGFS distributed file system, capable of achieving 80 Gbps of sustained write throughput across five nodes, essential for managing the high data volumes generated by a 25 high performance computer (HPC) compute cluster. To ensure operational efficiency and scalability, the tasks performed on the Linux compute cluster consisting of 30 nodes are automated using Ansible, facilitating seamless deployment, management, and updates. We present compilation strategies for a hardware accelerated Polyphase Filter Bank (PFB) channelization routine optimized …

Time-Dependent Strain-Resistance Relationships In Silicone Nanocomposite Sensors, Alex Mikal Wonnacott

Theses and Dissertations

Flexible high-deflection strain gauges have been demonstrated as cost-effective and accessible sensors for capturing human biomechanical deformations. However, the interpretation of these sensors is notably more complex compared to conventional strain gauges, partially owing to the viscoelastic nature of the strain gauges. On top of the non-linear viscoelastic behavior, dynamic resistance response is even more difficult to capture due to spikes in resistance during strain changes. This research examines the relationships between stress, strain, and resistance in nanocomposite sensors during dynamic strain situations. Under the assumption that both macroscopic stress and resistance are governed by microscopic stress concentrations at the …

Application Of High-Deflection Strain Gauges To Characterize Spinal-Motion Phenotypes Among Patients With Clbp, Spencer Alan Baker

Theses and Dissertations

Chronic low back pain (CLBP) is a nonspecific and persistent ailment that entails many physiological, psychological, social, and economic consequences for individuals and societies. Although there is a plethora of treatments available to treat CLBP, each treatment has varying efficacy for different patients, and it is currently unknown how to best link patients to their ideal treatment. However, it is known that biopsychosocial influences associated with CLBP affect the way that we move. It has been hypothesized that identifying phenotypes of spinal motion could facilitate an objective and repeatable method of determining the optimal treatment for each patient. The objective …

Investigating Which Muscles Are Most Responsible For Tremor Through Both Experimental Data And Simulation, Daniel Benjamin Free

Theses and Dissertations

Tremor affects millions of people and many patients desire alternative treatment options to medication or neural surgery. Peripheral suppression techniques are gaining greater use, but are currently applied in a trial-and-error method. To optimize these techniques, the muscles most responsible for an individual patient's tremor need to be identified. In this dissertation, I explored two parallel paths that both could aid in identifying muscles responsible for tremor. The first method utilizies measured data and a technique (coherence) that quantifies the frequency dependent correlation between two signals. Using coherence to identify muscles contributing to tremor requires at least two parts: an …

Rfi Mitigation And Discrete Digital Signal Processing Rfsoc Algorithm Implementations For Radio Astronomy And Wideband Communication Systems, Devon Christopher Ward

Theses and Dissertations

Due to the massive increase of active transmitters broadcasting over wideband frequencies, such as 5G wireless systems, LEO/MEO satellites, satellite constellations, and the increase of IoT devices in the average home, the radio frequency spectrum is becoming more and more congested by interference. Passive receivers face additional challenges due to the growing use of wideband frequency transmissions aimed at boosting communication system throughput. As a result, passive receivers must adopt more robust and intricate techniques to mitigate radio frequency interference. A proposed RFI removal system, known as the true time delay Hadamard projection algorithm, has been introduced in previous work …

Digital Performance Management: An Evaluation Of Manufacturing Performance Management Andmeasurement Strategies In An Industry 4.0 Context, Nathaniel David Smith

Theses and Dissertations

Manufacturing management and operations place heavy emphasis on monitoring and improving production performance. This supervision is accomplished through strategies of manufacturing performance management, a set of measurements and methods used to monitor production conditions. Over the last thirty years the most prevalent measurement of traditional performance management has been overall equipment effectiveness, a percentile summary metric of a machine's utilization. The technologies encapsulated by Industry 4.0 have expanded the ability to gather, process, and store vast quantities of data, creating opportunity to innovate on how performance is measured. A new method of managing manufacturing performance utilizing Industry 4.0 technologies has …

Comparison Of Empirical And Analytical Eigenfunctions As Bases For Reduced Order Methods In Heat Transfer, Jakob G. Bates, Matthew R. Jones, Christopher R. Dillon, John Tencer

Student Works

Reduced order methods using spectral representations show promise in facilitating and accelerating heat transfer analyses. This paper proposes a taxonomy for reduced order methods, classifying a method as reduced order compression, modelling, or analysis. The performance of bases formed with analytical and empirical eigenfunctions are compared for representative reduced order tasks. The Akaike Information Criterion is applied in a novel way to compare the performance of these bases. The present study finds that both bases are parsimonious for reduced order compression tasks. Empirical eigenfunctions are more robust to for reduced order modelling with variations in modelling parameters such as thermal …

Xylan Fast Pyrolysis: An Experimental And Modelling Study Of Particle Changes And Volatiles Release, F Cerciello, E Freisewinkel, A Coppola, C Ontyd, D Tarlinski, Martin Schiemann, Osvalda Senneca, Pierro Salatino, C Allouis, Victor Scherer, Thomas H. Fletcher

Faculty Publications

Biomass char particles produced by pyrolysis may have different morphologies, which has important implications on burning mode, conversion rate and boiler efficiency. These features are difficult to address due to the complexity of biomass structure and pyrolysis reaction models. The present work reports preliminary results on the morphological changes and volatile release that solid particles of Xylan experience upon fast heating in a Drop Tube Reactor (DTR) and in a Heated Strip Reactor (HSR) in a range of temperature between 1100 and 1573 K under inert atmosphere with heating rate in the order of 10³ K/s. Two different Xylan …

Review Of Computational Models For Large-Scale Mdao Of Urban Air Mobility Concepts, Darshan Sarojini, Marius L. Ruh, Jiayao Yan, Luca Scotzniovsky, Nicholas C. Orndorff, Ru Xiang, Han Zhao, Joshua J. Krokowski, Michael Warner, Sebastiaan Pc Van Schie, Ashley Cronk, Alexandre T. R. Guibert, Jeffrey T. Chambers, Lauren Wolfe, Rachel Doring, Robin Despins, Cibin Joseph, Ryan Anderson, Andrew Ning, Hyunjune Gill, Seongkyu Lee, Zeyu Cheng, Zhi Cao, Chunting Mi, Y Shirley Meng, Christopher Silva, Jiun-Shyan Chen, H. Alicia Kim, John T. Hwang

Faculty Publications

The advent of Urban Air Mobility (UAM) has necessitated a paradigm shift in aircraft design from traditional regression methods to physics-based analysis and the use of modern computational methods. This paper explores the intricacies of UAM aircraft design, acknowledging the limitations of historical empirical equations and advocating for the use of physics-based tools in the early stages of the design process. It underscores the importance of Multidisciplinary Design, Analysis, and Optimization (MDAO) as a means to integrate physics-based tools for conceptual design, facilitating decisions on configuration and sizing. The paper presents a comprehensive survey and review of computational models across …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Characterization Of Friction At The Tool/Material Interface In Friction Stir Welding, Bryan Gonzalo Ramos Gonzales

Theses and Dissertations

Friction Stir Welding (FSW) process development is very costly, and it is still experimental. A predictive model would optimize the weld by changing parameters and obtaining results that reflect the physical process. Friction is the primary adjustable parameter in FSW modeling. Currently, friction model selection is not physic-based. It is based on what is available and contributes to the best fit between the model and experimental data. The research objective is to characterize the interface tool/base material by studying the effect of tool friction coefficient and thermal properties. This is accomplished by changing welding parameters such as force, rpm, and …

Optimal Method To Obtain Soil Strength Properties In Sands For Laterally Loaded Pile Analysis In Lpile, Troy Roger Washburn

Theses and Dissertations

One common software program developed for analyzing single laterally loaded piles is called LPILE. Soil properties are required as input into LPILE. For sands, the soil properties required are effective soil unit weight, γ’; subgrade modulus, k; and the internal friction angle, ϕ’. There are two commonly used methods to obtain ϕ’ and subsequently k: the API method and Bolton method. Fourteen different pile test sites were used in the analysis of the API and Bolton methods to obtain soil strength properties in sands for laterally loaded single pile tests. Between the fourteen pile test sites, a total of 26 …

Assuring Netlist-To-Bitstream Equivalence Using Physical Netlist Generation And Structural Comparison, Reilly Mckendrick, Jeffrey Goeders, Keenan Faulkner

Faculty Publications

Hardware netlists are generally converted into a bitstream and loaded onto an FPGA board through vendor-provided tools. Due to the proprietary nature of these tools, it is up to the designer to trust the validity of the design’s conversion to bitstream. However, motivated attackers may alter the CAD tools’ integrity or manipulate the stored bitstream with the intent to disrupt the functionality of the design. This paper proposes a new method to prove functional equivalence between a synthesized netlist, and the produced FPGA bitstream. The novel approach is comprised of two phases: first, we show how we can utilize implementation …

A Personal Tribute To Professor Ashok Midha, Larry L. Howell

Faculty Publications

When I received the news that Professor Ashok Midha had passed away, I was grieved by the unexpected news. But I also felt another emotion: gratitude for having known him. I am grateful for him, for the opportunity I had to learn from him, and for the influence he has had on my life and career. I wanted to honor his memory in some way. This document is in response to that desire.

Some of my thoughts at his passing are summarized in the first chapter and the conclusion. The other writing is taken from a draft of my personal …

Void Formation And Mortality During Liquid Composite Molding, Jared Michael Turner

Theses and Dissertations

Within the high-performance composite manufacturing industry, there exists a need to improve the reliability of LCM (Liquid Composite Molding) manufacturing processes in producing composite parts that better approach the quality and consistency of pre-impregnated composite tapes that are cured in autoclaves with cost being a driving factor of this need. One obstacle to that end is the phenomenon of void formation during the LCM infusion processes. The formation of these voids through different mechanisms leads to composite parts with lower mechanical properties and consistency than their pre-impregnated autoclave cure counterparts. The objective of this research is to investigate the different …

Development Of Battery-Grade Silicon Through Magnesiothermic Reduction Of Halloysite-Derived Silica, Nathan Clarke

Theses and Dissertations

The production of halloysite-derived silicon (HDS) is investigated as a potential anode material in lithium-ion batteries (LIBs). Other researchers have found HDS to be electrochemically active in small test cells. To test larger electrochemical cells, the production process needs to be scaled up and optimized. HDS is produced through magnesiothermic reduction of acid-etched halloysite. The reduction process is very exothermic and requires special consideration while being scaled up. A reactor and pressure release system were designed and fabricated to perform the reduction process in a safe manner. Various steps of the process were tested to determine their influence on the …

Dam Failure And Incident Investigations, Nathaniel Gee

Theses and Dissertations

There are multiple dam failures and dam safety incidents every year in the United States. There are currently no standard policy requirements for when or how to conduct failure or incident investigations. This paper first reviews one of the most significant failures in US history, the failure of Buffalo Creek Dam No. 3 in order to explore the impacts of one significant failure on dam safety policy in the US. The paper then explores the currents state of the industry by reviewing 58 different dam failure or incident investigation reports based on incidents that occurred in the United States from …

Pullout Strength Of Welded Wire And Ribbed Strip Reinforcement In Lightweight Cellular Concrete Backfill Behind Mechanically Stabilized Earth Wall, Mathew Robert Bueckers

Theses and Dissertations

Lightweight cellular concrete (LCC) is a cement, water, and air entrained mixture that consists of 25-80% voids. The air voids reduce the material strength but also decrease the material weight. Due to its lightweight properties LCC is an attractive alternative to soil backfill for retained structures, such as mechanically stabilized earth (MSE) walls. Although LCC is widely used behind MSE walls, limited information exists regarding the pullout strength of MSE wall reinforcements in LCC backfill. This research attempts to fill the knowledge gap through performing pullout tests on welded wire and ribbed strip reinforcements in MSE walls to determine the …

A Tunable System For High Frequency Bioimpedance Plethysmography, Daniel H. Tebbs

Theses and Dissertations

Bioimpedance measurements are useful for determining a variety of biological conditions. By accounting for small impedance variations due to the arterial pulse, the effect of the blood can be studied more closely. The quasi-circulator system presented enables monitoring of pulsatile impedance changes with input frequencies above 1 MHz. The adjustable Rmatch allows for dynamic tuning of the system to increase sensitivity. By tuning Rmatch to be near the match point, the pulsatile signal in the output magnitude can be amplified, and tuning Rmatch to be at the match point causes the pulsatile signal in the output phase to be amplified. …

Lcc Mse Walls, Joel Smith

Theses and Dissertations

Lightweight cellular concrete (LCC) is mainly a mixture of water, cement, and foam bubbles. LCC generally has a cast density between 20-60 pcf and an air content between 49-84%. LCC is often used as a fill material because it has a low unit weight which reduces settlement. LCC is increasingly being considered as a backfill behind Mechanically Stabilized Earth (MSE) walls and embankments. Although engineers are using LCC in MSE walls or free face walls (MSE wall without the concrete panels or reinforcements), there is presently a lack of information regarding the performance and behavior of LCC to guide them. …

Evaluation Of Unmanned Aerial Vehicle Flight Parameters That Impact Stockpile Volume Computations, Nicole Marie Hastings

Theses and Dissertations

Stockpile volumes are monitored by their companies as the product (i.e., aggregate, soil) is moved in and out of the facilities to ensure minimal product loss. Companies are mandated to report product movement to the government to ensure that the aggregate and soil is going where it is supposed to go. Many tools are used to monitor stockpile volumes including truck scales (to weigh incoming and outgoing trucks), light detection and ranging (LiDAR), Global Navigation Satellite System (GNSS) equipment, and unmanned aerial vehicle (UAV) photogrammetry. These processes give a good estimate of stockpile volumes. Errors in these estimates typically come …

Dynamic Segmental Kinematics Of The Lumbar Spine During Diagnostic Movements, Paul Mcmullin

Theses and Dissertations

While lumbar kinematics can be measured in vivo, most measurements are invasive (such as percutaneous bone pins), provide high doses of radiation (such as biplane fluoroscopy), or are taken with the patient in a static position (such as MRIs). Recent work suggests that lumbar kinematics can be determined by dynamic measurements of epidermal strain in the lower back. This work aims to develop and examine a method of examining lumbar kinematics via optoelectronic motion capture utilizing skin-mounted markers in the lumbar region. Two studies were performed. One study examined lumbar epidermal strain in 28 asymptomatic subjects during diagnostic movements, while …

Combined Design And Dispatch Optimization For Nuclear-Renewable Hybrid Energy Systems, Daniel Clyde Hill

Theses and Dissertations

Reliable, affordable access to electrical power is a requirement for almost all aspects of developed societies. Challenges associated with reducing carbon emissions has led to growing interest in nuclear-renewable hybrid energy systems (N-RHES). Much work has already been done in suggesting and analyzing various N-RHES using a variety of optimization techniques and assumptions. This work builds upon previous techniques for simultaneous combined design and dispatch optimization (CDDO) for hybrid energy systems (HES). The first contribution of this work is the development and application of sensitivity analysis tailored to the combined design and dispatch optimization problem. This sensitivity analysis cover uncertainty …

A Series Of Improved And Novel Methods In Computer Vision Estimation, James J. Adams

Theses and Dissertations

In this thesis, findings in three areas of computer vision estimation are presented. First, an improvement to the Kanade-Lucas-Tomasi (KLT) feature tracking algorithm is presented in which gyroscope data is incorporated to compensate for camera rotation. This improved algorithm is then compared with the original algorithm and shown to be more effective at tracking features in the presence of large rotational motion. Next, a deep neural network approach to depth estimation is presented. Equations are derived relating camera and feature motion to depth. The information necessary for depth estimation is given as inputs to a deep neural network, which is …

Analysis And Simulation Of Nuclear Thermal Energy Storage Systems For Increasing Grid Stability, Jaron Wallace

Theses and Dissertations

With the growing capacity of renewable energy production sources, nuclear energy, once a mainstay of power generation, faces challenges due to its limited adaptability to fluctuating energy demands. This inherent rigidity makes it less desirable than the more flexible renewable sources. However, integrating thermal energy storage (TES) systems offers a promising avenue, enabling nuclear power plants (NPPs) to enhance their operational flexibility and remain competitive in an evolving renewable market. A comprehensive ranking methodology has been introduced, delineating the criteria and processes to determine the most synergistic TES/NPP design couplings. This methodology considers the unique characteristics of both current and …

Investigating The Effects Of Unfused Powder Damping In Laser Powder Bed Fusion, Samuel Hao Teng

Theses and Dissertations

This study uses Additive Manufacturing (AM) processes to fabricate 316L stainless steel beams with pockets of unfused powder for increased damping. Modal testing was completed to compare damping factors of beams with varying pocket geometries as well as number of pockets and pocket location. For the first three bending modes that were tested, an initial damping increase was observed when pocket height is greater than powder diameter. Following the initial increase there is a height threshold, which is mode dependent, that is required to achieve a statistically significant increase in damping.

Economy Of Scale Of Energy Intensity In Aquifer Storage And Recovery (Asr), Alyson Haley Rapp

Theses and Dissertations

More water utilities are adopting Aquifer Storage and Recovery (ASR) to balance long-term water supply and demand. Due to large implementation and operation costs, ASR projects need to be optimized, particularly for energy use, which is a major operating expense. This study examines the relationships among energy use, recharge, and recovery at two ASR projects in the western United States. The major finding is an economy of scale for recovery processes, but not for gravity-fed recharge processes. The economy of scale found is as follows: the energy intensity recovered decreases with volume. This suggests it is more energy-efficient to recover …

An Inexpensive, 3d Printable, Arduino And Bluray-Based, Confocal Laser And Fluorescent Scanning Thermal Microscope, Justin Loose

Theses and Dissertations

The Fluorescence Scanning Thermal Microscope (FSTM v3.0), was designed to create an inexpensive, and easily manufactured, device for measuring the diffusivity of samples with microscopic locational precision. This was accomplished by using a Blu-ray device known as a PHR-803T, referred to in this work as a PHR. The optics in the PHR are nearly identical in function to conventional devices used in thermoreflectance microscopy, making the PHR extremely useful to integrate into the FSTM design. The focus of this thesis is the application of the FSTM as a confocal microscope using 3D printed components and various low-cost devices to operate …

Using Jtag For External Scrubbing On The Amd Versal Acap, Michael L. Bjerregaard

Theses and Dissertations

The Versal Adaptive Compute Acceleration Platform (Versal ACAP) is a system-on-chip (SoC) developed by AMD Xilinx. To help protect the programmable logic from soft errors, the configuration needs to be constantly checked and repaired through a process called scrubbing. This thesis provides a methodology for scrubbing the configuration over JTAG. The scrubber uses two platform device image (PDI) files, one to read the configuration and one to send corrected frames. The methodology is characterized to determine the time it takes to completely scrub the configuration. The designed scrubber was able to scrub the VM1802 in 11.5 seconds, or 41.6 Mbits/second, …