Engineering Commons^™

U-Splines: Splines Over Unstructured Meshes, Steven K. Schmidt

Theses and Dissertations

U-splines are a novel approach to the construction of a spline basis for representing smooth objects in Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE). A spline is a piecewise-defined function that satisfies continuity constraints between adjacent cells in a mesh. U-splines differ from existing spline constructions, such as Non-Uniform Rational B-splines (NURBS), subdivision surfaces, T-splines, and hierarchical B-splines, in that they can accommodate local variation in cell size, polynomial degree, and smoothness simultaneously over more varied mesh configurations. Mixed cell types (e.g., triangle and tetrahedron and quadrilateral and hexahedral cells in the same mesh) and T-junctions are also supported. The …

Towards Trojan Detection From A Raw Bitstream, Corey Ryan Simpson

Theses and Dissertations

Many avenues exist to insert malicious circuitry into an FPGA designs, including compromised CAD tools, overwriting bitstream files, and post-deployment attacks. The proprietary nature of the Xilinx bitstreams precludes the ability to validate an implemented design. This thesis introduces the BitRec and IPRec projects in an effort to support trojan detection tools. BitRec provides a novel approach to mapping of the Xilinx bitstream format into FPGA features in order to recreate the original design's netlist. BitRec supports the 7 Series, UltraScale and UltraScale+ architectures. IPRec then provides a novel approach to recognizing parameterizable IP within a flattened netlist in an …

Photo-Induced Drug Release From Polymeric Micelles And Liposomes: Phototriggering Mechanisms In Drug Delivery Systems, Najla M. Salkho, Nahid S. Awad, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

Chemotherapeutic drugs are highly effective in treating cancer. However, the side effects associated with this treatment lower the quality of life of cancer patients. Smart nanocarriers are able to encapsulate these drugs to deliver them to tumors while reducing their contact with the healthy cells and the subsequent side effects. Upon reaching their target, the release of the encapsulated drugs should be carefully controlled to achieve therapeutic levels at the required time. Light is one of the promising triggering mechanisms used as external stimuli to trigger drug release from the light-responsive nanocarriers. Photo-induced drug release can be achieved at a …

A Comparison Of Square-Wave Voltammetry Models To Determine The Number Of Electrons Exchanged In Metal Deposition, Ranon Fuller, Tyler Williams, Mark H. Schvaneveldt, Devin Rappleye

Faculty Publications

A comparison of square-wave voltammetry models for calculating the number of electrons exchanged in a metal deposition reaction. Experiments were conducted for silver deposition on platinum in an aqueous HNO₃ solution and for nickel and lanthanum deposition on platinum in molten LiCl. Diffusion coefficients for Ni²⁺ and La³⁺ in LiCl at 700^oC are calculated. Accuracy of soluble-soluble models versus a soluble-insoluble model is discussed. A simple method for determining the number of electrons exchanged under the constraint of well-compensated ohmic drop is proposed and evaluated.

The Effect Of Soot Models In Oxy-Coal Combustion Simulations, Kamron Groves Brinkerhoff

Theses and Dissertations

Soot in coal combustion simulations is often ignored due to its computational complexity, despite significant effects on flame temperature and radiation. In this research, a 40 kW oxy-coal combustion system is modeled using Large Eddy Simulations (LES) and a semi-empirical monodisperse coal soot model. Simulation results are compared to experimental measurements of temperature, species concentrations, and soot concentration. Cases where soot is modeled are compared with cases where soot is neglected to determine the accuracy benefits of modeling soot. The simulations were able to replicate experimental results within an acceptable level of error. Including soot in the simulations did not …

Multipath Mitigation In Frequency Selective Channels With An Emphasis On 5g Cellular Mobile Networks And Aeronautical Mobile Telemetry Applications, Farah Arabian

Theses and Dissertations

This dissertation explores the role of polarization, combining, and equalization operating over frequency-selective channels to improve the reliability of wireless communications systems in terms of BER for two applications: 5G mobile networks (operating in the mmWave band and NR FR1), and aeronautical mobile telemetry systems (operating in L band). The equivalent discrete-time models for a variety of spatial combining techniques at 5G mmWave bands were derived to investigate the performance of co-located cross-polarized antenna elements when polarization diversity is used and also when a combination of spatial and cross-polarized antennas is exploited. In both cases, ML combining has the lowest …

Managing Radio Frequency Interference In Vehicular Multi-Antenna Transceivers, Jakob W. Kunzler

Theses and Dissertations

Radio frequency interference is an ever growing problem in the wireless community. This dissertation presents methods to reduce interference for vehicular multi-antenna devices. This document is organized into two parts: the main chapters and the appendices. The main chapters present research conducted primarily by the author. These deserve the reader's primary attention. The appendices showcase contributions made by the author serving in a supporting role to projects led by others and/or do not fit the vehicular theme. These should receive secondary attention. The main chapter contributions are summarized as follows. A device was created that provides over 105 dB of …

Low-Cost Prosthetic Feet For Underserved Populations: A Comparison Of Gait Analysis And Mechanical Stiffness, Kaleigh Renninger, Brevin Banks, Dustin A. Bruening

Library/Life Sciences Undergraduate Poster Competition 2022

• Lower limb loss is an ongoing cause of disability throughout the world.
• Despite advancements in prosthetic technologies, there are numerous underserved populations in need of effective low-cost prosthetic foot options.

Kemar Hats Head Orientation Directivity, Samuel D. Bellows, Timothy W. Leishman

Directivity

This directivity data set for a KEMAR head head-and-torso simulator (HATS) includes head orientations in 14 directions in 5° steps starting from 0° to 40° and then in 10° steps from 40° to 90°. The full spherical measurements followed at an a = 0.97 m radius with the mouth aperture at the spherical center. The sampling density and distribution followed the AES 5° dual-equiangular sampling standard, omitting the south pole (θ = 180°). Thus, each spherical directivity assessment included 36 polar-angle θ samples and 72 azimuthal-angle ϕ samples. The presented data include 22 1/3-octave bands, ranging from 80 Hz …

Ph-Responsive Nanocarriers In Cancer Therapy, Nour M. Alsawaftah, Nahid S. Awad, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

A number of promising nano-sized particles (nanoparticles) have been developed to conquer the limitations of conventional chemotherapy. One of the most promising methods is stimuli-responsive nanoparticles because they enable the safe delivery of the drugs while controlling their release at the tumor sites. Different intrinsic and extrinsic stimuli can be used to trigger drug release such as temperature, redox, ultrasound, magnetic field, and pH. The intracellular pH of solid tumors is maintained below the extracellular pH. Thus, pH-sensitive nanoparticles are highly efficient in delivering drugs to tumors compared to conventional nanoparticles. This review provides a survey of the different strategies …

Thermosensitive Polymers And Thermo-Responsive Liposomal Drug Delivery Systems, Waad H. Abuwatfa, Nahid S. Awad, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

Temperature excursions within a biological milieu can be effectively used to induce drug release from thermosensitive drug-encapsulating nanoparticles. Oncological hyperthermia is of particular interest, as it is proven to synergistically act to arrest tumor growth when combined with optimally-designed smart drug delivery systems (DDSs). Thermoresponsive DDSs aid in making the drugs more bioavailable, enhance the therapeutic index and pharmacokinetic trends, and provide the spatial placement and temporal delivery of the drug into localized anatomical sites. This paper reviews the fundamentals of thermosensitive polymers, with a particular focus on thermoresponsive liposomal-based drug delivery systems.

Modeling Data And Reactor Data Associated With The Design, Modeling, And Testing Of The Pressurized Oxy-Coal (Poc) Reactor, Bradley R. Adams, Andrew R. Fry, Dale R. Tree

ScholarsArchive Data

Data files in the zipped folders below contain research and development information related to the design, modeling, construction and testing of a pressurized, dry feed, oxy-coal reactor at Brigham Young University between 2016 and 2021. The reactor is a once-through system that includes a pressurized dry-coal feed system, a slagging combustion reactor, a spray quench and tube and shell heat exchanger for gas cooling, a cyclone particle collector, and gas depressurization and dilution system. The system is operated with an OPTO22 control system and includes instrumentation to measure gas and wall temperature profiles, radiative heat flux profiles (indicative of flame …

Optimization Of A Smart Sensor Wearable Knee Sleeve For Measuring Skin Strain To Determine Joint Biomechanics, David Steven Wood

Theses and Dissertations

This work addresses three objectives related to the design and modeling of an instrumented knee sleeve and its high deflection strain gauges for at-home knee rehabilitation. First, a multi-objective Bayesian approach was developed to economically optimize a high deflection strain gauge's mechanical and electrical behavior. Four objective functions were simultaneously optimized with two design variables in seven iterations; 90% faster than a grid search approach. The presented algorithm adjusts variables in the manufacturing process of high deflection strain gauges and produces a sensor with optimized properties for a predetermined purpose. Second, an algorithm was created to accurately approximate the dynamic …

Flood Warning: A Generalized Approach To Forecast The Impacts Of Flooding Events Using Arcgis Pro, Qgis, And Python, Robert Evan Smith

Theses and Dissertations

Floods are the most common global natural disaster, and 1 billion people live in floodplains worldwide adding to the impactful damage that inundation causes. Disaster managers strive to mitigate damages to their communities but need to know what the impact of a potential flood may be. GEOGloWS ECMWF Streamflow Services estimates forecasted streamflow around the world. These forecasted streamflow's can be used to create predicted flood extent maps using Height Above Nearest Drainage (HAND) or Sedimentation and River Hydraulics - Two Dimension (SRH-2D). Another method to obtain a flood map is using Setinel-1 satellite Synthetic Aperture Radar (SAR) imagery. Flood …

Gibbs–Duhem Relation For Phase-Field Models Of Polymeric Mixtures, Rami Alhasan, Douglas R. Tree

Faculty Publications

Phase-field models are relatively inexpensive field-based models capable of capturing the nonequilibrium multiphase behavior of polymers and other soft materials. With their rise in popularity over the past several years, questions have arisen concerning the thermodynamic consistency of some model formulations. In doing so, researchers have employed several different forms of the Gibbs–Duhem equation─a classical thermodynamic relationship used to assess consistency─leading to questions about the correct form of this expression for inhomogeneous mixtures. In this paper, we derive a generalized Gibbs–Duhem relation that is valid for phase-field models. The key to the derivation is the recognition that the functional derivatives …

Fundamentally Based Investigation And Mathematical Modeling Of The Delay Observed In The Early Stages Of E-Coat Deposition, Fardin Padash

Theses and Dissertations

The objective of this work is to enhance the understanding of the delay observed in the early stages of E-coat deposition. E-coat deposition has been widely used by industries such as the automotive industry to form the primary protective coating against corrosion. Currently, models that are used to find the best conditions under which the desired coating coverage for the entire auto body can be achieved do not accurately predict the coating coverage in recessed areas. The accuracy of large-scale models can be improved by enhancing our understanding of the mechanisms responsible for the observed delay. To accomplish this, experiments …

A Phase Field Model For Dynamic Simulations Of Reactive Blending Of Polymers, Mukul D. Tikekar, Kris T. Delaney, Michael C. Villet, Douglas R. Tree

Faculty Publications

A facile way to generate compatibilized blends of immiscible polymers is through reactive blending of end-functionalized homopolymers. The reaction may be reversible or irreversible depending on the end-groups and is affected by the immiscibility and transport of the reactant homopolymers and the compatibilizing copolymer product. Here we describe a phase-field framework to model the combined dynamics of reaction kinetics, diffusion, and multi-component thermodynamics on the evolution of the microstructure and reaction rate in reactive blending. A density functional with no fitting parameters, which is obtained by adapting a framework of Uneyama and Doi and qualitatively agrees with self-consistent field theory, …

Closed Loop Recycling Of Low Friction Polymers In Fused Granule Fabrication Additive Manufacturing Processes, Neil Thompson, Jason Weaver

Faculty Publications

Plastic waste is a critical worldwide problem that impacts additive manufacturing (AM). Extensive research has explored how plastic waste in AM can be reduced by recycling prints into new filament, with varying success. An alternative to filament-based extrusion is “fused granule fabrication” (FGF), which extrudes from pellets or granules. This method is often used for large area additive manufacturing (LAAM) of polymers. This paper expands upon the knowledge base from previous research on LAAM and examines the extent to which PETG can be recycled and reprinted through the same FGF tool without significant loss to its material properties. The metric …

Durability Of Vacuum Infusion Tooling Produced From Fused Granular Fabrication Additive Manufacturing, Nathan Northrup, Jason Weaver, Andy R. George

Faculty Publications

Large area additive manufacturing (LAAM) has the capability to create tooling that is lower cost than conventionally manufactured tooling and still has sufficient properties for many applications. A vacuum infusion mold was printed from fiberglass-ABS and evaluated for wear and suitability for small vacuum infusion runs. The mold was designed to accentuate high wear as a “worst case” scenario. The mold was able to produce 10 parts successfully before any noticeable change occurred to the surface finish. By 14 parts, the surface finish had roughened sufficiently that demolding was difficult and resulted in damage to the part. Profilometry measurements showed …

Considering Thickness-Accommodation, Nesting, Grounding And Deployment In Design Of Miura-Ori Based Space Arrays, Terri Bateman, Diana Bolanos, Nathan Brown, Brooklyn Clark, Larry L. Howell, Collin Ynchausti, Hunter Pruett, Jared Hunter, Spencer P. Magleby

Faculty Publications

The Miura-ori pattern exhibits favorable qualities desirable for deployable space arrays – especially achieving a large deployed area from a compact stowed volume. However, implementing the Miura-ori into a finite-thickness, engineered system poses challenges that are not manifest in a zero-thickness model. As such, it is important to understand and address the limitations of the pattern before implementing it into an engineered system. This paper presents the Miura-ori as a favorable, yet challenging, pattern in design of deployable space arrays. Challenges including thickness-accommodation, nesting, grounding and deployment are presented to introduce designers to unapparent complications associated with design of Miura-ori …

Incorporating High-Fidelity Aerostructural Analyses In Wind Turbine Rotor Optimization, Denis-Gabriel Caprace, Adam Cardoza, Andrew Ning, Marco Mangano, Sicheng He, Joaquim R. R. A. Martins

Faculty Publications

s demand grows for wind turbines with larger blades, the design of future wind turbines must account for multi-physical interactions and an ever-increasing number of design load conditions. One aspect, aerostructural coupling, calls for design tools that are both accurate and computationally efficient. In this paper, we present a combined-fidelity approach that couples high-fidelity computational fluid dynamics and computational solid mechanics simulations, with a conventional aeroelastic turbine modeling tool based on blade element momentum and beam theories. The approach is integrated into a multidisciplinary optimization framework. It takes advantage of the high-fidelity tightly-coupled aerostructural simulations to evaluate the rotor power …

A General Coupling Methodology For Unsteady Aerostructural Optimization With Analytic Derivatives, Taylor Mcdonnell, Adam Cardoza, Denis-Gabriel Caprace, Andrew Ning

Faculty Publications

Multidisciplinary design optimization offers a comprehensive approach for designing complex aerostructural systems such as wind turbines. Gradient-based multidisciplinary design optimization can be used to optimize complex systems using large numbers of design variables. However, the convergence of gradient-based optimization methods to an optimal solution is highly dependent on the accuracy of the provided derivatives. In this paper, we propose a general method for creating unsteady coupled systems for steady-state, eigenvalue, and time-domain analyses. We then describe how highly accurate derivatives may be obtained from these analyses using a combination of automatic differentiation and analytic methods (including the unsteady adjoint). Finally, …

Review—Concentration Measurements In Molten Chloride Salts Using Electrochemical Methods, Tyler Williams, Rankin Shum, Devin Rappleye

Faculty Publications

The electrochemical measurement of concentration in molten chloride salts is a valuable tool for the control of existing and potential industrial processes, recycling of precious materials and energy production. The electrochemical techniques commonly used to measure concentration and each techniques’ associated theory are discussed. Practices which improve measurement accuracy and precision are set forth. Exceptionally accurate and precise measurements published in the literature are evaluated based on their performance in specified concentration ranges. The strengths and weaknesses of the most accurate measurements are briefly explored. Chronopotentiometry (CP) and square wave voltammetry (SWV) are accurate and precise with low concentration measurements. …

Investigation Of Lithium-Ion Battery Electrode Fabrication Through A Predictive Particle-Scale Model Validated By Experiments, Mojdeh Nikpour

Theses and Dissertations

Next-generation batteries with improved microstructure and performance are on their way to meet the market demands for high-energy and power storage systems. Among different types of batteries, Li-ion batteries remain the best choice for their high energy density and long lifetime. There is a constant but slow improvement in Li-ion batteries by developing new materials and fabrication techniques. However, further improvements are still needed to meet government and industry goals for cost, cycling performance, and cell lifetime. A fundamental understanding of particle-level interactions can shed light on designing new porous electrodes for high-performance batteries. This is a complex problem because …

A Visually Realistic Simulator For Autonomous Evtol Aircraft, Seth M. Nielsen

Theses and Dissertations

Electrically powered vertical takeoff and landing (eVTOL) aircraft could provide a new mode of air transportation of people and cargo that is low-cost, on-demand, and able to reach more areas than is possible with current technology. They have the unique ability to takeoff and land in congested spaces yet efficiently travel long distances which makes them a promising technology for applications such as rapid medical assistance, automated package delivery, or human transportation. This type of aircraft has only recently become a possibility, owing to advancements in battery technology, computing power, and sensor technologies, and thus support for eVTOLs is lacking …

Laser Forming Of Compliant Mechanisms And Flat-Foldable Furniture, Daniel Calvin Ames

Theses and Dissertations

Compliant mechanisms are useful for improving existing machines and creating new ones that were not previously possible. They also help us to think of new methods and technologies needed to both improve existing systems as well as manufacture systems that have not been done before. The purpose of this thesis is to show novel implementations of compliant mechanisms into folding systems, and to show new methods for fabricating such mechanisms with nontraditional materials and on difficult scales. Folding systems are shown in furniture applications with chairs, stools, and childcare furniture applications as results of research into how such structures could …

Prediction Equations To Determine Induced Force On Reinforcing Elements Due To Laterally Loaded Piles Behind Mse Wall And Lateral Load Test On Dense Sand, Pedro David Garcia Montesinos

Theses and Dissertations

Researchers performed 35 full-scale lateral load tests on piles driven within the reinforcement zone of a mechanically stabilized earth wall (MSE wall). Data defining the induced tensile force on the reinforcements during lateral pile loading was used to develop multi-linear regression equations to predict the induced tensile force. Equations were developed by previous researchers that did not consider the diameter of the pile, the fixed head condition, relative compaction, or cyclic loading. The purpose of this research was to include this tensile force data and develop prediction equations that considered these variables. Additionally, a full-scale lateral load test was performed …

Advancing Cell-Free Protein Synthesis Systems For On-Demand Next-Generation Protein Therapeutics And Clinical Diagnostics, Emily Ann Long Zhao

Theses and Dissertations

Recombinant proteins have many medical and industrial applications, but their use is complicated by commercial production and stability constraints. These issues are particularly challenging for recombinant proteins used in pharmaceutical therapeutics and clinical diagnostics. Expensive production and distribution limit the accessibility of therapeutics and diagnostics especially in the developing world. Additionally, clinical use of recombinant proteins face further challenges within biological systems including biological degradation and immunogenicity. To increase the accessibility of recombinant proteins, the cost and inefficiencies of protein manufacturing and distribution need to be significantly reduced. A powerful tool to aid in this endeavor is cell-free protein synthesis …

Identifying And Evaluating Common Subgenres In Asymmetric Virtual Reality Games, Miah Dawes

Theses and Dissertations

Recent years have seen a significant growth in what designers and players call asymmetric virtual reality (AVR) games. This dissertation creates a framework that defines the relevant characteristics of AVR as a genre and describes five common genres of AVR games, including David(s) and Goliath, Hide and Seek, Perspective Puzzle, Order Simulation, and Lifeline. The core features of each subgenre are expounded. These subgenres are then evaluated using design workshops to observe novice game designs use these subgenres in their game design process. An analysis of the workshops found that the AVR subgenre framework may benefit novice game designers in …

A Geometric Approach To Multiple Target Tracking Using Lie Groups, Mark E. Petersen

Theses and Dissertations

Multiple target tracking (MTT) is the process of localizing targets in an environment using sensors that perceive the environment. MTT has many applications such as wildlife monitoring, air traffic monitoring, and surveillance. These applications motivate further research in the different challenging aspects of MTT. One of these challenges that we will focus on in this dissertation is constructing a high fidelity target model. A common approach to target modeling is to use linear models or other simplified models that do not properly describe the target's pose (position and orientation), motion, and uncertainty. These simplified models are typically used because they …