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Enhancing Surface Texturing Of Zirconia Toughened Alumina Ceramic Through Optimized Electric Discharge Machining Utilizing The Assistive Electrode Method, Yazan Eyas Tuffaha
Enhancing Surface Texturing Of Zirconia Toughened Alumina Ceramic Through Optimized Electric Discharge Machining Utilizing The Assistive Electrode Method, Yazan Eyas Tuffaha
Theses and Dissertations
Zirconia toughened alumina (ZTA) is a durable and biocompatible ceramic material commonly used in prosthetic hip implants because of its excellent mechanical properties and wear/corrosion resistance. Surface texturing can improve the lubricity and longevity of hip implant bearing surfaces, but precision machining of ceramic materials such as ZTA is very difficult due to suboptimal surface integrity results of traditional machining techniques. This thesis explores the optimization of machining ZTA using electric discharge machining (EDM) - a process usually reserved for conductive metals - to machine holes into the ceramic to create surface textures. EDM is made possible through the assistive …
Void Formation During Liquid Composite Molding Under Varied Pressure With Mechanical Properties Validation, Neil Russell Thompson
Void Formation During Liquid Composite Molding Under Varied Pressure With Mechanical Properties Validation, Neil Russell Thompson
Theses and Dissertations
Composite materials have revolutionized products and how they are manufactured. Most large-scale aerospace companies utilize a carbon fiber pre-impregnated with a resin in conjunction with an autoclave to minimize voids, but it is very expensive and requires a great amount of space. The less expensive alternative to prepreg-autoclave processes is known as Liquid Composite Molding (LCM), in which the resin is brought into a mold via overpressure on the resin supply or by a vacuum in the mold. But this process is more prone to voids due to bubble formation. Voids are a critical issue as common failure modes such …
Fission Product Thermodynamics, Solubility, And Extraction In Molten Salts And Lead, Richard Lee Fitzhugh
Fission Product Thermodynamics, Solubility, And Extraction In Molten Salts And Lead, Richard Lee Fitzhugh
Theses and Dissertations
Chemical behavior of fission products in systems relevant to two major advanced nuclear reactor systems, namely the lead-cooled fast reactor (LFR) and molten-salt reactor (MSR), has been studied with a heavy emphasis on thermodynamics. The behavior of fission products in molten salts is examined from a theoretical perspective, with an emphasis on the standard state used to define the thermodynamic activity. A standard state extrapolated from infinite dilution behavior, which is fairly common practice in electrochemistry, is found to facilitate faster, easier, and simpler analysis while retaining much of the accuracy of the complex Modified Quasichemical Model. Inductively-coupled plasma mass …
Tools For Planning Multi-Axis Vibration Qualification Tests, Marcus Edward Behling
Tools For Planning Multi-Axis Vibration Qualification Tests, Marcus Edward Behling
Theses and Dissertations
Vibration qualification testing is necessary to ensure that components will endure vibration-induced damage in flight. Multi-axis tests have shown the potential for improvement over single-axis tests, though they require increased planning. This work focuses on planning three critical aspects of these tests: the amount of operational next assembly to include in the test, the size of shakers to use, and the number of shakers to use. Next assembly selection is studied by varying the amount of next assembly included in the lab test, performing physical tests, and comparing the accuracy of environment reconstruction in each test. In doing so, a …
Design For Pullout Resistance And Global Stability Of Metallic Reinforcements In Mse Walls With Lightweight Cellular Concrete Backfill, Joshua Curt Peterson
Design For Pullout Resistance And Global Stability Of Metallic Reinforcements In Mse Walls With Lightweight Cellular Concrete Backfill, Joshua Curt Peterson
Theses and Dissertations
Lightweight cellular concrete (LCC) is a type of concrete that has reduced density and weight compared to traditional concrete. This is achieved by incorporating a large amount of air- filled cells or voids into the mixture. The resulting material is lighter, yet still possesses considerable strength and durability, making it suitable for a range of construction applications, especially in the case of retaining walls because of its reduced weight. Unlike traditional concrete, which can be extremely heavy and place significant stress on the supporting structure, lightweight cellular concrete reduces the pressure on the retaining wall, helping to prevent deformation and …
Demand Side Management Through Integrated Water Distribution Systems And Smart Irrigation Controllers, Nathan T. Lunstad
Demand Side Management Through Integrated Water Distribution Systems And Smart Irrigation Controllers, Nathan T. Lunstad
Theses and Dissertations
The innovation of electrical utilities in creating smart electrical grids has superseded that of water utilities in analogous efforts. While many water utilities are now using smart water technologies, they lack the virtual command center that allows for two-way communication for more effective forecasting, load balancing, preventive methods, emergency and master planning, and level of service delivery while ensuring environmental justice and enhancing the responsible use of resources. In this dissertation, I propose the idea of the Integrated Water Distribution System (IWDS) to overcome this challenge. IWDS coordinates management of water supply and demand in a way that benefits both …
Tribological Analysis Of Heat Treatments On Medical Grade Cobalt Chromium Molybdenum Alloys, Samuel Edis Bowden
Tribological Analysis Of Heat Treatments On Medical Grade Cobalt Chromium Molybdenum Alloys, Samuel Edis Bowden
Theses and Dissertations
Cobalt chromium molybdenum (CoCrMo) has many material properties that make it desirable as a medical hip implant. Due to the range of heat treatments available and the resulting material properties that are present in medical device manufacturing using CoCrMo, many implants are not able to withstand both the chemical and physical wear necessary as a hip replacement. This research looks to examine various heat treatments and their resulting properties to find a desirable heat treatment for CoCrMo in hip implant bearing surfaces. This study was accomplished by using five distinct variations of heat treatment on forged CoCrMo alloy that would …
Engineering Cell-Free Protein Synthesis Biosensors For Point Of Care Use, Tyler Jordan Free
Engineering Cell-Free Protein Synthesis Biosensors For Point Of Care Use, Tyler Jordan Free
Theses and Dissertations
Diagnostic tests can dramatically improve and save lives. Survival rates and patient outcomes related to cancer and other diseases can be improved when routine testing guides personalized treatment. Highly accurate laboratory tests exist for thousands of biomarkers, including those of interest in this dissertation, but cost and complexity limit access to life-saving lab tests in many cases throughout the world. To fill this need and increase accessibility of diagnostics, in this report we report our engineering advancements towards portable biosensors for colorimetric detection of glutamine, endocrine disrupting compounds (EDC), and pathogenic RNA which are key biomarkers in cancer treatment monitoring, …
A Comparative Illustration Of Trip- And Activity-Based Modeling Techniques, Steven Hayden Atchley
A Comparative Illustration Of Trip- And Activity-Based Modeling Techniques, Steven Hayden Atchley
Theses and Dissertations
Activity-based travel demand models are generally considered superior to their trip-based counterparts, as activity-based models (ABMs) explicitly model individuals in contrast to the aggregate nature of trip-based models. There have been a number of comparisons between trip- and activity-based models, but these comparisons focus almost exclusively on the technical ability of the two model types, while not considering the practical benefits an ABM may or may not have to a transportation agency. This research performs a more holistic comparison between trip- and activity-based models, focused specifically on the practical differences between model types, both in terms of usability and capability …
Real-Time Dynamically Feasible B-Spline Trajectory Generation For Unmanned Aircraft, David Lavae Christensen
Real-Time Dynamically Feasible B-Spline Trajectory Generation For Unmanned Aircraft, David Lavae Christensen
Theses and Dissertations
Onboard aircraft systems must frequently plan dynamically feasible paths or trajectories to safely and quickly reach their goal position. Optimized B-splines are promising because they can guarantee kinematic feasibility in a computationally efficient manner and can be applied to a variety of vehicle models. However, current B-spline solutions do not adequately constrain trajectories to the physical limitation of the vehicles they are planning for, or are often too conservative. Most are also limited to path smoothing or require pre-optimized timing parameters. This thesis develops a real-time B-spline optimization-based trajectory generator capable of minimizing time while respecting the velocity, acceleration, and …
Development And Application Of A Particle-Based Reactor Network Model For Entrained Flow Gasifier Design, Eric Christian Monson
Development And Application Of A Particle-Based Reactor Network Model For Entrained Flow Gasifier Design, Eric Christian Monson
Theses and Dissertations
A novel particle-based reactor network model (PRNM) was developed to predict the performance of a dry-feed, pressurized, single-stage, slagging entrained flow gasifier under various operational parameters. This model provides improved detail of particle conversion as a function of gasifier location, particle size, and fuel type not available in standard reactor network models. The model inputs were designed to allow changes in geometry, firing rate, stoichiometric ratio, fuel type, and inlet gas composition. Key performance metrics included the gas and refractory temperature profiles, axial gas compositions, and particle burnout. PRNM used a network of idealized reactors to specify the flow field …
Proposing A Matrix For Selecting Security Tools For Small Businesses, Nathan Jonathon Rowbotham
Proposing A Matrix For Selecting Security Tools For Small Businesses, Nathan Jonathon Rowbotham
Theses and Dissertations
Small businesses are increasingly under threat of cybersecurity attacks. An increasingly long list of tools with different purposes and coverage are available to help. But it can be difficult to choose which tools to use, particularly for a small business that may lack financial resources, expertise, and time. Research literature focuses on providing frameworks to follow to protect a business generally. Some research considers an aspect of creating a Security Operations Center. Other research describes the creation of a Security Operations Center as a Service with all the components the researchers deemed necessary. None of the current research literature seems …
Design And Validation Of Sensing Knee Sleeve Rehabilitation Device Utilizing Large Deflection Strain Gauges, Kurt Christian Jensen
Design And Validation Of Sensing Knee Sleeve Rehabilitation Device Utilizing Large Deflection Strain Gauges, Kurt Christian Jensen
Theses and Dissertations
Total knee arthroplasty (TKA) procedures are increasingly common in the US and globally. However, rehabilitation outcomes may be negatively affected by limited access to physical therapy and patients' tendency to not fully adhere to recommended exercises between therapy sessions. This study aims to develop a remote system to aid rehabilitation, building upon recent sensor development at Brigham Young University, providing physical therapy-like biofeedback during unsupervised at-home exercises. The system developed by this research consists of three primary components: (1) a sensor array for measuring leg/knee biomechanics, (2) a machine learning algorithm to predict knee flexion angle from the sensor data, …
Subspace Decomposition Of Linear Secrecy Codes, David Robert Joseph Hunn
Subspace Decomposition Of Linear Secrecy Codes, David Robert Joseph Hunn
Theses and Dissertations
We introduce a new method for the study of linear codes, termed subspace decomposition, which provides new insights into code structure and performance. Briefly, subspace decomposition comprises the evaluation of complex properties of a linear code by evaluating simple properties of its constituent subspaces. We find that this technique has application to a number of problems in coding theory. When applied to the problem of evaluating the performance of secrecy codes, subspace decomposition provides an efficient method for computing the equivocation of coset codes over the binary erasure wiretap channel. It is also especially efficient in computing the chi squared …
Design Considerations For Self-Deploying Origami-Inspired Space Arrays, Kathryn Faith Varela
Design Considerations For Self-Deploying Origami-Inspired Space Arrays, Kathryn Faith Varela
Theses and Dissertations
Origami engineering involves many steps, including selecting a pattern, accommodating for thickness, and choosing stabilization, damping, and deployment methods, the last of which is particularly important if the array is intended to self-deploy. Through metrics and case studies, this research strives to aid designers in creating origami-inspired deployable arrays. The approaches vary as each chapter focuses on a different aspect of origami engineering. By introducing a thickness accommodation technique and reducing complications with rigid-foldability (when applicable), this work shows how the geometrical structure can be modified to help the array stow and deploy. By providing quantitative and qualitative metrics for …
Reconfigurable Over-The-Air Chamber: Measuring Radio Frequency Device Performance, Benjamin T. Arnold
Reconfigurable Over-The-Air Chamber: Measuring Radio Frequency Device Performance, Benjamin T. Arnold
Theses and Dissertations
Over-the-air (OTA) testing is particularly useful in determining the performance of multi-antenna communication devices in real-world environments. Traditional OTA testing technologies include the reverberation chamber (RC) and the multi-probe anechoic chamber. More recently, the reconfigurable OTA chamber (ROTAC), which is a RC that has probes lining its chamber walls, has been proposed. These probes are either driven with a source, possibly combined with a channel emulator, or are terminated with a tunable impedance. Controlling the excitations and terminations on the probes can alter the fields within the chamber and thereby synthesize an antenna response at the device under test (DUT). …
3d Printed Mounts For Liquid Microdroplet Resonators, Parker A. Awerkamp
3d Printed Mounts For Liquid Microdroplet Resonators, Parker A. Awerkamp
Theses and Dissertations
Liquid microdroplet resonators provide an excellent tool for optical studies due to their innate smoothness and high quality factors, but they can be difficult to control. By using 3D printed mounts to support the droplets, we can obtain precise control over the droplet geometries and positions. We here present our work with oil, water, and ice microdroplets, as well as tools required to enable their study. We first present methods for creating 3D printed mounts for oil microdroplet resonators. The mounts enable precise positioning of the droplets relative to a tapered optical fiber. The oil microdroplet resonators exhibited quality factors …
Membrane Hinges For Deployable Systems, C. Mitchel Skinner
Membrane Hinges For Deployable Systems, C. Mitchel Skinner
Theses and Dissertations
Origami-inspired and deployable technology has become increasingly common in a variety of applications including satellite and antenna designs for space applications. The drive to utilize ultra-thin materials in the design of these deployable space structures has led to the development of membrane hinges. Membrane hinges show promise as an effective surrogate fold because of their potential advantages including requiring minimal volume and mass, allowing for small bending radii, and functioning without lubricant. Two challenges associated with membrane hinges include reliability after repeated cyclic loading and predictability of a large deployable with radially-unconstrained membrane hinges. The research presented includes the cyclic …
Characterizing And Manipulating Intra-Die Performance Variation Of Fpgas And Its Application In Security, Hayden C. Cook
Characterizing And Manipulating Intra-Die Performance Variation Of Fpgas And Its Application In Security, Hayden C. Cook
Theses and Dissertations
Field Programmable Gate Arrays (FPGAs) are reconfigurable, high-performing devices that are often used in critical applications. However, like all semiconductors, FPGAs experience transistor aging that can lower performance and lead to device failures. Additionally, device aging also has several security implications. Therefore, understanding the aging mechanisms behind transistor aging is necessary to ensure the reliability of FPGAs. However, current aging studies either rely on simulation alone or are unable to isolate aging effects on specific elements within the FPGA. This dissertation uses the reconfigurability of FPGAs to develop novel aging techniques that allow for the targeted aging of specific areas …
Tool Life Characterization In Refill Friction Stir Spot Welding, Ruth Guadalupe Belnap
Tool Life Characterization In Refill Friction Stir Spot Welding, Ruth Guadalupe Belnap
Theses and Dissertations
As light-weighting becomes a priority for the automotive industry, refill friction stir spot welding emerges with enormous potential to supplement or replace conventional spot joining processes. This thesis addresses the limitations of current tooling options by examining materials beyond steel for use in RFSSW. Contained herein is an analysis of weld quality as a function of tool material, a production evaluation of RFSSW using various tool materials, and an assessment of long-term performance of a tungsten carbide tool. Over the course of this research, tungsten carbide emerged as a viable candidate for long-lasting RFSSW tooling.
Understanding The Mechanical And Electrochemical Impacts Of Binder Systems On Silicon Anodes In Lithium-Ion Batteries, Fei Sun
Theses and Dissertations
Silicon has emerged as a promising alternative to traditional graphite as an anode material in battery technology, primarily due to its high theoretical capacity and abundance. However, its application is hindered by significant challenges, including severe volume expansion in the active material (~275%) during cycling, which can lead to a series of electrode failure issues. Polymer binder plays an essential role in addressing these challenges as it accommodates silicon's volume expansion and the rearrangement of particles. This work conducted an analysis of how different binders influence mechanical and electrochemical properties of silicon electrodes. Our findings are supported by a series …
Ocean Rain Detection And Wind Retrieval Through Deep Learning Architectures On Advanced Scatterometer Data, Matthew Yoshinori Otani Mckinney
Ocean Rain Detection And Wind Retrieval Through Deep Learning Architectures On Advanced Scatterometer Data, Matthew Yoshinori Otani Mckinney
Theses and Dissertations
The Advanced Scatterometer (ASCAT) is a satellite-based remote sensing instrument designed for measuring wind speed and direction over the Earth's oceans. This thesis aims to expand and improve the capabilities of ASCAT by adding rain detection and advancing wind retrieval. Additionally, this expansion to ASCAT serves as evidence of Artificial Intelligence (AI) techniques learning both novel and traditional methods in remote sensing. I apply semantic segmentation to ASCAT measurements to detect rain over the oceans, enhancing capabilities to monitor global precipitation. I use two common neural network architectures and train them on measurements from the Tropical Rainfall Measuring Mission (TRMM) …
The Design, Prototyping, And Validation Of A New Wearable Sensor System For Monitoring Lumbar Spinal Motion In Daily Activities, Brianna Bischoff
The Design, Prototyping, And Validation Of A New Wearable Sensor System For Monitoring Lumbar Spinal Motion In Daily Activities, Brianna Bischoff
Theses and Dissertations
Lower back pain is a widespread problem affecting millions worldwide, because understanding its development and effective treatment remains challenging. Current treatment success is often evaluated using patient-reported outcomes, which tend to be qualitative and subjective in nature, making objective success measurement difficult. Wearable sensors can provide quantitative measurements, thereby helping physicians improve care for countless individuals around the world. These sensors also have the potential to provide longitudinal data on daily motion patterns, aiding in monitoring the progress of treatment plans for lower back pain. In this work it was hypothesized that a new wearable sensor garment that makes use …
Manipulating Colloidal Particles Using Chemical Gradients And Top-Down Control, Mark Nichols Mcdonald
Manipulating Colloidal Particles Using Chemical Gradients And Top-Down Control, Mark Nichols Mcdonald
Theses and Dissertations
Colloidal particles provide the ideal building blocks for the next generation of microdevices, such as advanced sensors and precision drug delivery systems. However, many such applications require the use of top-down (i.e. humanly controllable) forces to manipulate colloidal particles with single-particle precision, and current methods can only achieve such precision for small numbers of particles at a time. To address this challenge, we propose using chemical forces in combination with existing top-down techniques to enable the control of larger numbers of particles simultaneously. Controlling colloids using chemical reactions is a novel technique not typically utilized. Due to its distinct difference …
Infared Light-Based Data Association And Pose Estimation For Aircraft Landing In Urban Environments, David Akagi
Infared Light-Based Data Association And Pose Estimation For Aircraft Landing In Urban Environments, David Akagi
Theses and Dissertations
In this thesis we explore an infrared light-based approach to the problem of pose estimation during aircraft landing in urban environments where GPS is unreliable or unavailable. We introduce a novel fiducial constellation composed of sparse infrared lights that incorporates projective invariant properties in its design to allow for robust recognition and association from arbitrary camera perspectives. We propose a pose estimation pipeline capable of producing high accuracy pose measurements at real-time rates from monocular infrared camera views of the fiducial constellation, and present as part of that pipeline a data association method that is able to robustly identify and …
Feasibility Of Parallelized Measurement Of Local Thermal Properties, Alexander J. Hansen
Feasibility Of Parallelized Measurement Of Local Thermal Properties, Alexander J. Hansen
Theses and Dissertations
This thesis documents research done in the development and the exploration of feasibility for a high-throughput method to measure local thermal properties. The present capabilities in the measurement of local thermophysical properties such as thermal conductivity, thermal diffusivity, and Kapitza resistance are very inefficient and impractical to fully understand and characterize heat transport through certain materials and features. This work follows up on past work in local thermal property measurement via the spatial domain thermoreflectance (SDTR) method, and explores the possibility of parallelizing the process. The parallelized SDTR (P-SDTR) method involves using laser projector sources to periodically heat and measure …
Control, Localization, And Shock Optimization Of Icosahedral Tensegrity Systems, Brett Layer
Control, Localization, And Shock Optimization Of Icosahedral Tensegrity Systems, Brett Layer
Theses and Dissertations
Exploring the design space of tensegrity systems is the basis of the work presented in this thesis. The areas explored as part of this research include the optimization of tensegrity structures to minimize the size of a tensegrity structure given payload shock constraints, and the control and locomotion of an icosahedral tensegrity system using movable masses and using an accelerometer in conjunction with leveraging geometrical knowledge of an icosahedral tensegrity system to localize the system after the system moves. In the optimization design space, a simplified model was created to represent an icosahedral tensegrity structure. This was done by assuming …
Digitally Beamformed 2d Scanning Phased Array Radar For Networked Unmanned Air Vehicle Detection And Tracking, Carson Reed Brown
Digitally Beamformed 2d Scanning Phased Array Radar For Networked Unmanned Air Vehicle Detection And Tracking, Carson Reed Brown
Theses and Dissertations
Radar systems vary significantly in size, weight, power, and cost (SWaP-C) characteristics with many high SWaP-C models being inaccessible to consumers. Recognizing this, we have engineered an effective but low SWaP-C networked radar system tailored for detecting and tracking unmanned air vehicle (UAV) traffic. Using field-programmable gate arrays (FPGAs), and custom-designed printed circuit boards (PCBs), our system achieves remarkable efficiency without compromising performance. We use patch antennas for our transmitter and in our 4x4 receiver array. With our low SWaP-C system we have successfully concluded outdoor range testing, detecting corner reflector targets at a remarkable 10dB above our noise floor …
Effects Of Print Process Parameters On Droplet-Powder Interaction In Binder Jet Additive Manufacturing, Jacob Lawrence
Effects Of Print Process Parameters On Droplet-Powder Interaction In Binder Jet Additive Manufacturing, Jacob Lawrence
Theses and Dissertations
Binder jet additive manufacturing (BJ) offers unique advantages, including the ability to produce complex geometries and utilize a wide range of materials, but faces challenges related to part quality and defect formation. This thesis investigates the effects of process parameters on droplet-powder interaction, powder relocation, and line formation in BJ printing. A custom BJ test platform was developed to enable precise control over key process parameters and in-situ monitoring. High-speed synchrotron X-ray imaging revealed modes of powder relocation above and below the powder bed surface. Testing revealed that parameters that increase moisture in the powder bed, such as lower droplet …
The Advancement Of Experimental And Computation Tools For The Study Of Molten Salt Chemistry To Facilitate The Extraction Of Strategic Elements In Nuclear Applications, Michael Stoddard
Theses and Dissertations
Nuclear energy presents environmental benefits, yet the challenge of radioactive waste management persists. Advanced solutions, such as Molten Salt Reactors (MSRs), require a more profound understanding of molten salt chemistry. This research aims to develop tools, including a depletion simulator, molten salt electrochemical simulator, and a fluoride-based thermodynamic reference electrode for electrochemical purification. The computationally inexpensive depletion simulator allows for exploration into extraction and processing strategies for molten salt reactors. An illustrative case study on Mo-99 production from MSRs demonstrates the practical application of the theoretical framework, emphasizing the need for optimization in extraction effectiveness and separation difficulty. The electrochemical …