Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Mechanical Engineering (1342)
- Civil and Environmental Engineering (1183)
- Electrical and Computer Engineering (758)
- Chemical Engineering (757)
- Civil Engineering (650)
-
- Computer Engineering (641)
- Other Civil and Environmental Engineering (641)
- Data Storage Systems (632)
- Environmental Engineering (629)
- Hydraulic Engineering (573)
- Construction Engineering and Management (91)
- Manufacturing (71)
- Biomedical Engineering and Bioengineering (46)
- Other Engineering (39)
- Physical Sciences and Mathematics (38)
- Social and Behavioral Sciences (34)
- Other Mechanical Engineering (33)
- Operations Research, Systems Engineering and Industrial Engineering (31)
- Education (25)
- Geography (22)
- Engineering Education (21)
- Geographic Information Sciences (20)
- Computer Sciences (16)
- Business (15)
- Medicine and Health Sciences (15)
- Arts and Humanities (14)
- Biochemical and Biomolecular Engineering (13)
- Industrial Technology (12)
- Life Sciences (12)
- Keyword
-
- UAV (104)
- FPGA (86)
- Optimization (74)
- Coal (71)
- Compliant mechanisms (59)
-
- Pyrolysis (52)
- Unmanned aircraft (52)
- Origami (47)
- Modeling (45)
- MEMS (39)
- Design (37)
- Machine learning (37)
- Remote sensing (37)
- Scatterometer (37)
- Simulation (37)
- CFD (36)
- Friction stir welding (36)
- Microfluidics (36)
- Combustion (35)
- Biomass (33)
- GIS (33)
- Liquefaction (32)
- Model predictive control (32)
- Engineering (30)
- Heat transfer (30)
- Additive manufacturing (29)
- Model (29)
- QuikSCAT (28)
- CAD (27)
- Finite element analysis (27)
- Publication Year
- Publication
-
- Theses and Dissertations (2410)
- Faculty Publications (1187)
- International Congress on Environmental Modelling and Software (629)
- Journal of Undergraduate Research (438)
- Biomedical Engineering Western Regional Conference (46)
-
- Undergraduate Honors Theses (28)
- Student Works (27)
- ScholarsArchive Data (23)
- Engineering Applications of GIS - Laboratory Exercises (21)
- Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE) (10)
- BYU Research Development Office Research Networking Conference (8)
- Directivity (5)
- Marriott Student Review (5)
- BYU West Mountain Observatory Project (2)
- Books (2)
- Brigham Young University Prelaw Review (2)
- FEAT Publications (2)
- FHSS Mentored Research Conference (1)
- Journal of Nonprofit Innovation (1)
- Library Research Grants (1)
- Library/Life Sciences Undergraduate Poster Competition 2019 (1)
- Library/Life Sciences Undergraduate Poster Competition 2022 (1)
- Publication Type
- File Type
Articles 271 - 300 of 4850
Full-Text Articles in Engineering
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 …
Deep Learning For Improved Data-Driven Modeling Of Soft Robots For Model Predictive Control, Daniel Gray Cheney
Deep Learning For Improved Data-Driven Modeling Of Soft Robots For Model Predictive Control, Daniel Gray Cheney
Theses and Dissertations
The field of soft robotics is a growing research interest due to the unique benefits of soft robots over traditional robots, such as durability, compliance, and low-cost. These benefits allow soft robots to perform a variety of tasks that would be difficult for traditional robots, such as throwing, hammering, or whole-body manipulation. However, there is a significant variety of materials, actuators, and designs used in soft robotics. While helpful for completing more tasks, this variety also makes efficient modeling and control of soft robots difficult. In this thesis, an open-source repository, Modeling for Learned Dynamics (MoLDy), is presented. This repository …
Vco Calibration Techniques And Design Of A 0.12-V Ultra-Low Supply Analog-To-Digital Converter, Shea Smith
Vco Calibration Techniques And Design Of A 0.12-V Ultra-Low Supply Analog-To-Digital Converter, Shea Smith
Theses and Dissertations
Many analog-to-digital converters (ADC) quantize inputs using a voltage-controlled-oscillator (VCO). These VCO-based ADCs leverage time-domain processing to shape quantization noise and mismatch, which further increases their appeal. Despite these advantages, achieving good performance with a VCO-based ADC remains a significant challenge due to the nonlinear transfer characteristics of the voltage-to-frequency (V-F) conversion. VCO-based ADCs widely utilize coarse-fine readout to save power and hardware compared to counter-only converters. However, the timing mismatch due to the clock skew between the coarse and fine quantizers can lead to significant reconstruction errors. Chapter 2 proposes a digital calibration circuit to detect and correct coarse-fine …
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 …
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 …
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, …
Acousto-Dielectric Tweezers Enable Independent Manipulation Of Multiple Particles, Liang Shen, Zhenhua Tian, Kaichun Yang, Joseph Rich, Jinxin Zhang, Jianping Xia, Wesley Collyer, Brandon Lu, Nanjing Hao, Zhichao Pei, Chuyi Chen, Tony Jun Huang
Acousto-Dielectric Tweezers Enable Independent Manipulation Of Multiple Particles, Liang Shen, Zhenhua Tian, Kaichun Yang, Joseph Rich, Jinxin Zhang, Jianping Xia, Wesley Collyer, Brandon Lu, Nanjing Hao, Zhichao Pei, Chuyi Chen, Tony Jun Huang
Faculty Publications
Acoustic tweezers have gained substantial interest in biology, engineering, and materials science for their label-free, precise, contactless, and programmable manipulation of small objects. However, acoustic tweezers cannot independently manipulate multiple microparticles simultaneously. This study introduces acousto-dielectric tweezers capable of independently manipulating multiple microparticles and precise control over intercellular distances and cyclical cell pairing and separation for detailed cell-cell interaction analysis. Our acousto-dielectric tweezers leverage the competition between acoustic radiation forces, generated by standing surface acoustic waves (SAWs), and dielectrophoretic (DEP) forces, induced by gradient electric fields. Modulating these fields allows for the precise positioning of individual microparticles at points where …
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 …
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). …
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 …
Transient Heat Transfer To Rolling Or Sliding Drops On Inclined Heated Superhydrophobic Surfaces, Joseph Furner, Daniel Maynes, Brian D. Iverson, Julie Crockett
Transient Heat Transfer To Rolling Or Sliding Drops On Inclined Heated Superhydrophobic Surfaces, Joseph Furner, Daniel Maynes, Brian D. Iverson, Julie Crockett
Faculty Publications
The thermal transport to drops that roll or slide down heated superhydrophobic surfaces is explored. High-speed infrared imaging is performed to provide time-resolved measurement of the heat transfer to the drop. Data are obtained for drops moving along smooth hydrophobic and structured superhydrophobic surfaces. Both post and rib style structures with surface solid fractions ranging from 0.06 to 1.0 are considered. The inclination angle of the surfaces was varied from 10 deg to 25 deg, and the drop volume was varied from 12 to 40 µL. The measurements reveal that the drop speed is a strong function of both the …
Comparing Gas Composition From Fast Pyrolysis Of Live Foliage Measured In Bench-Scale And Fire-Scale Experiments, David R. Weise, Thomas H. Fletcher, Timothy J. Johnson, Wei Min Hao, Mark Dietenberger, Marko Princevac, Bret W. Butler, Sara S. Mcallister, Joseph J. O'Brien, E Louise Loudermilk, Roger D. Ottmar, Andrew T. Hudak, Akira Kato, Babak Shotorban, Shankar Mahalingham, Tanya L. Myers, Javier Palarea-Albaladejo, Stephen P. Baker
Comparing Gas Composition From Fast Pyrolysis Of Live Foliage Measured In Bench-Scale And Fire-Scale Experiments, David R. Weise, Thomas H. Fletcher, Timothy J. Johnson, Wei Min Hao, Mark Dietenberger, Marko Princevac, Bret W. Butler, Sara S. Mcallister, Joseph J. O'Brien, E Louise Loudermilk, Roger D. Ottmar, Andrew T. Hudak, Akira Kato, Babak Shotorban, Shankar Mahalingham, Tanya L. Myers, Javier Palarea-Albaladejo, Stephen P. Baker
Faculty Publications
Background. Fire models have used pyrolysis data from oxidising and non-oxidising environments for flaming combustion. In wildland fires pyrolysis, flaming and smouldering combustion typically occur in an oxidising environment (the atmosphere). Aims. Using compositional data analysis methods, determine if the composition of pyrolysis gases measured in non-oxidising and ambient (oxidising) atmospheric conditions were similar. Methods. Permanent gases and tars were measured in a fuel-rich (non-oxidising) environment in a flat flame burner (FFB). Permanent and light hydrocarbon gases were measured for the same fuels heated by a fire flame in ambient atmospheric conditions (oxidising environment). Log-ratio balances of the measured gases …
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 …
Effect Of Local Chain Stiffness On Oligomer Crystallization From A Melt, Pierre Kawak, Christopher Akiki, Douglas R. Tree
Effect Of Local Chain Stiffness On Oligomer Crystallization From A Melt, Pierre Kawak, Christopher Akiki, Douglas R. Tree
Faculty Publications
While the process by which a polymer crystal nucleates from the melt has been extensively studied via molecular simulation, differences in polymer models and simulated crystallization conditions have led to seemingly contradictory results. We make steps to resolve this controversy by computing low-temperature phase diagrams of oligomer melts using Wang-Landau Monte Carlo simulations. Two qualitatively different crystallization mechanisms are possible depending on the local bending stiffness potential. Polymers with a discrete bending potential crystallize via a single-step mechanism, whereas polymers with a continuous bending potential can crystallize via a two-step mechanism that includes an intermediate nematic phase. Other model differences …
Ready, Set, Grow: From Micelles To Giant Vesicles Via Biocatalytic Activation, Nicholas P. Bair, Qinyu Zhu, Bryon A. Staynings, Douglas R. Tree, Walter F. Paxton
Ready, Set, Grow: From Micelles To Giant Vesicles Via Biocatalytic Activation, Nicholas P. Bair, Qinyu Zhu, Bryon A. Staynings, Douglas R. Tree, Walter F. Paxton
Faculty Publications
Controlling physicochemical processes that drive changes in supramolecular aggregates is an important objective toward creating artificial soft micro- and nanomachines. Previous research explored the morphology control of membrane-based materials subjected to externally imposed chemical stimuli. Here, we modulate the microscale morphology of pH-responsive assemblies by using biocatalysis to internally generate changes in global pH. Catalytic reactions offer flexibility in the mechanism and rate at which stimuli are introduced to responsive assemblies, ultimately enabling precision and control over size and morphology. We observed, by dynamic light scattering and fluorescence microscopy, substantial microscale differences between assemblies subjected to manually titrated pH changes …
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 …
Drop Dynamics And Heat Transfer During Dropwise Condensation On Superhydrophobic Surfaces, Shaur Humayun
Drop Dynamics And Heat Transfer During Dropwise Condensation On Superhydrophobic Surfaces, Shaur Humayun
Theses and Dissertations
As we seek to address the escalating demand for energy and water, superhydrophobic surfaces have gained the attention of researchers due to their potential to boost condensation heat transfer rates and improve efficiency across various applications. One way to significantly improve dropwise condensation heat transfer rate is to improve drop mobility. Water-repelling properties of superhydrophobic surfaces can help in reducing the size of condensed drops as they depart the surface, thus increasing drop refresh rates by increasing drop mobility. Accurate models of retention forces between drops and superhydrophobic surfaces are needed for predicting drop dynamics including drop mobility. Once drop …
Ductape: A Steady-State, Axisymmetric Ducted Fan Analysis Code Designed For Gradient-Based Optimization, Judd Mehr, Andrew Ning
Ductape: A Steady-State, Axisymmetric Ducted Fan Analysis Code Designed For Gradient-Based Optimization, Judd Mehr, Andrew Ning
Faculty Publications
Electric ducted fans have become an intriguing option for the propulsion systems of clean, quiet advanced air mobility technologies due to their potential benefits in both aerodynamic efficiency and reduced noise profiles compared to open rotor systems. Exploration of conceptual electric ducted fan design in the context of novel, and often complex, applications may be greatly aided by the use of optimization techniques. Specifically, gradient-based optimization lends itself to the exploration of large, complex, multi-disciplinary systems due to its inherent scalability. Despite ducted fans/propellers having been relatively well studied for the last century, modern, gradient-based, optimization-ready analysis tools for ducted …
Solving Unsteady Potential Flow Problems In O(N) Time, Ryan Anderson, Andrew Ning
Solving Unsteady Potential Flow Problems In O(N) Time, Ryan Anderson, Andrew Ning
Faculty Publications
Design of vertical takeoff and landing aircraft is challenging in part due to significant aerodynamic interactions between rotors and wings. Computational models can aid in their design, but are computationally expensive. 3-D panel methods coupled with vortex particle wakes offer an attractive solution, but solving for the panel strengths scales poorly for large problems. Multigrid methods, such as Krylov subspace methods in conjunction with the fast multipole method (FMM), have been demonstrated to reduce the scaling to O(𝑁). We explore the performance and limitations of the Krylov-FMM method, traditional matrix-powered GMRES, LU decomposition, and a novel O(𝑁) multigrid approach to …
Geometrically Exact Beam Theory For Gradient-Based Optimization, Taylor Mcdonnell, Andrew Ning
Geometrically Exact Beam Theory For Gradient-Based Optimization, Taylor Mcdonnell, Andrew Ning
Faculty Publications
Decades of research have progressed geometrically exact beam theory to the point where it is now an invaluable resource for analyzing and modeling highly flexible slender structures. Large-scale optimization using geometrically exact beam theory remains nontrivial, however, due to the inability of gradient-free optimizers to handle large numbers of design variables in a computationally efficient manner and the difficulties associated with obtaining smooth, accurate, and efficiently calculated design sensitivities for gradient-based optimization. To overcome these challenges, this paper presents a finite-element implementation of geometrically exact beam theory which has been developed specifically for gradient-based optimization. A key feature of this …
Characteristics Of Pyrolysis Products Of California Chaparral And Their Potential Effect On Wildland Fires, Mahsa Alizadeh, David R. Weise, Thomas H. Fletcher
Characteristics Of Pyrolysis Products Of California Chaparral And Their Potential Effect On Wildland Fires, Mahsa Alizadeh, David R. Weise, Thomas H. Fletcher
Faculty Publications
The aim of this study was to investigate the pyrolysis of selected California foliage and estimate the energy content of the released volatiles to show the significance of the pyrolysis of foliage and its role during wildland fires. While the majority of the volatiles released during the pyrolysis of foliage later combust and promote fire propagation, studies on the energy released from combustion of these compounds are scarce. Samples of chamise (Adenostoma fasciculatum), Eastwood’s manzanita (Arctostaphylos glandulosa), scrub oak (Quercus berberidifolia), hoaryleaf ceanothus (Ceanothus crassifolius), all native to southern California, and sparkleberry …
Derivative Propagation Through Vortex Particle Method Simulation, Eric Green, Andrew Ning
Derivative Propagation Through Vortex Particle Method Simulation, Eric Green, Andrew Ning
Faculty Publications
Automatic differentiation (AD) is a powerful tool for evaluating numerical derivatives. In particular, reverse-mode AD provides numerical gradients in a way that is insensitive to the number of input variables. This makes reverse-mode AD well-suited for solving large optimization problems. However, reverse-mode AD has a particularly large associated memory cost because most intermediate values in operations need to be cached. This is problematic for large problems such as aerodynamics simulations, though, since the memory requirements can quickly become impractical. The solution implemented in this work is to provide analytic pullback expressions for functions for which many of the intermediate values …
Trajectory Optimization Of Evtol And Conventional Aircraft: A Comparative Analysis Of Vortex Particle Method And Vortex Lattice + Blade Element Momentum Theory, Andrew Tagg, Ryan Anderson, Cibin Joseph, Andrew Ning
Trajectory Optimization Of Evtol And Conventional Aircraft: A Comparative Analysis Of Vortex Particle Method And Vortex Lattice + Blade Element Momentum Theory, Andrew Tagg, Ryan Anderson, Cibin Joseph, Andrew Ning
Faculty Publications
Trajectory optimization of aircraft transition maneuvers can significantly influence the design of these systems, particularly when making decisions about aircraft geometry, propulsion sizing, and control system design. This paper presents the trajectory optimization of air vehicles including electric vertical takeoff and landing (eVTOL) as well as conventional aircraft. The study evaluates the influence of fidelity in trajectory design by comparing the use of two aerodynamic methods in the context of trajectory optimization. The mid-fidelity method utilizes a vortex lattice method (VLM) to model lifting surfaces while employing blade element momentum theory (BEMT) to model rudimentary rotor-wing interactions. The high-fidelity approach …
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 …
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.
Characterizing The Potential For Failure In Environment Testing Due To Bolted-Joint Friction Nonlinearity And Bilinearity, Brennen Clark
Characterizing The Potential For Failure In Environment Testing Due To Bolted-Joint Friction Nonlinearity And Bilinearity, Brennen Clark
Theses and Dissertations
Nonlinear behavior in systems complicates the analysis and design of many systems in engineering. In vibration engineering, typical methods such as modal analysis fail or require significant adjustment in the presence of nonlinearity. Understanding and modeling nonlinear behavior is becoming more important in many modern engineering applications. One area that is relatively unexplored is how nonlinearity affects environment testing. This can cover a wide variety of subtopics, but this thesis focuses on failures that can occur in a system which are not predicted by corresponding linearized systems. To further limit the scope of this work, and to provide a context …
Evaluating Computational Predictions Of Magnetic Resonance Acoustic Radiation Force Imaging For Breast Cancer Focused Ultrasound Surgery, Chloe K. Nelson
Evaluating Computational Predictions Of Magnetic Resonance Acoustic Radiation Force Imaging For Breast Cancer Focused Ultrasound Surgery, Chloe K. Nelson
Theses and Dissertations
Purpose: In magnetic resonance-guided focused ultrasound (MRgFUS) therapies performed in highly heterogeneous tissues such as the breast, the focal location must be located and characterized to guide successful treatments of tumors. Treatment time can be minimized by a priori prediction of the focal location through computational models. The purpose of this work is to evaluate numerical simulations of focused ultrasound (FUS) on their predictions of the focal location. Those simulations are compared to clinical magnetic resonance acoustic radiation force imaging (MR-ARFI) data collected during in vivo treatment of breast tumors. Methods: The focal location was evaluated prior to MRgFUS treatment …
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) …