Digital Commons Network^™

Wind Collapse Risk And Serviceability Drift Of Steel Concentrically Braced Frame Buildings, Sarah Corrinne Partington Cluff

Theses and Dissertations

Seismic design provisions use the ductility and reserve strength of the lateral structural system to reduce the loads used in design, making the structural design more economical while maintaining life safety. In contrast, current wind design provisions do not. Conventional wind design relies primarily on elastic behavior. The objective of this study is to determine a wind response modification factor for steel concentrically braced frames that could be applied to reduce wind design loads based on ductility and reserve strength, while still meeting drift requirements for serviceability of the structure. To achieve the objective, three types of ductile braced frames …

Steps Towards Effective Human-Robot Co-Manipulation Through Real-Time Modus Detection And Effects Of Stiffness Variation For Human-Soft-Robot Dyads, Shaden Moss

Theses and Dissertations

A group of individuals can coordinate very easily to carry a large or heavy object together. This act of collaborative carrying is called co-manipulation. Unlike human teammates, robots cannot easily detect and respond to the intent of human partners during co-manipulation tasks. This shortcoming can be compensated for via the physical design and the software design of robots. This work treats software design with a neural net that detects human modus (or the manner in which a team moves an object together) in real time. This work treats physical design with the use of a soft robot in human-robot co-manipulation, …

Improving Devices To Measure The Thermal Conductivity Of Molten Halide Salts, Ryan J. Ruth

Theses and Dissertations

Molten salts are of high interest for use in nuclear reactors, though their thermophysical properties are notoriously hard to measure due to the extreme conditions created by them. Significant gaps remain in thermal conductivity and heat capacity data, which this work seeks to fill by improving the Needle Probe-a modified transient hot wire probe originally used by Merritt et al to measure the thermal conductivity of FLiNaK- measuring two new salts, and exploring new materials for use with molten salts. Improvements made to the Needle Probe include automation to reduce human error, more accurate heat generation modeling, a more thorough …

Strength And Ductility Of Rod-Braced Diaphragms In Metal Building Systems Subjected To Earthquake Ground Motions, James Niedens

Theses and Dissertations

Metal building systems are a common form of construction but the behavior of roof diaphragms in metal buildings that are subjected to earthquake ground motions is not entirely understood. In this study, the strength and ductility of rod-braced diaphragms with hillside washer connections or rod-pad connections was determined using experimental tests and computer simulation. Tensile tests of rods were used to determine the effect of the type of rod on strength and ductility. Two types of rods were tested, full-body rods with cut threads at each end of the rod and bracing rods with rolled threads. Three rod sizes (5/8 …

Rf Emission From Partial Breakdown Events And Their Classification, Torin Sammeth

Electrical and Computer Engineering ETDs

Electrical breakdown is a core component of Pulse Power both in its utilization and as a failure point in systems. This research is investigating the feasibility of D-dot antennas to detect and potentially identify different forms of partial electrical breakdown in a point-to-plane gap geometry. In this work, the RF emission detected by a D-dot probe during a partial breakdown event is shown to correlate with the presence of light and current using a fast-current transformer and photomultiplier tube. Additionally, the frequency components of the RF signal were measured with the use of a fast Fourier transform. Identifying these frequencies …

Navajo Speech Recognition Using Low-Resource Language Models, Emery M. Sutherland

Electrical and Computer Engineering ETDs

This thesis describes the development of a speech recognition system to classify Navajo (Dine) words using Low Resource Language (LRL) datasets. Presently there are no recognized high-quality open-sourced datasets for the Dine language needed to train models for speech recognition. A small balanced dataset was designed to train several models. To overcome the scarcity of the LRL dataset, the audio recordings were augmented to account for time-stretching, amplitude variations, time shifts, small amounts of white Gaussian noise, and SpecAugmentation. The models included a Recurrent Neural Network (RNN), a Convolutional Neural Network (CNN), and a Long Short-Term Memory (LSTM) model with …

Integrating Temperature-Dependent Tissue Properties Into Hifu Computational Models For Enhanced Treatment Planning, Christian Kevin Valencia Narva

Theses and Dissertations

Objective: High-intensity focused ultrasound (HIFU) is a non-invasive therapy that ablates diseased tissues with high precision. Computational simulations using the Pennes Bioheat Transfer Equation (PBTE) can guide HIFU treatment by predicting temperature distributions and thermal dose volumes. Traditional simulations assume constant thermal and acoustic properties, which may oversimplify tissue behavior. Methods: This study evaluates the impact of integrating temperature-dependent thermal properties (thermal conductivity, specific heat capacity, and perfusion) in finite-difference time-domain HIFU simulations. Three scenarios were simulated: (1) a homogeneous liver with both high- and low-power sonications, (2) a rabbit thigh muscle validated against preclinical MRTI data, and (3) an …

Development And Evaluation Of Canbench: A Testbed For Assessing The Security Of Automotive Can Buses, Trevor S. Mcclellan

Theses and Dissertations

Modern vehicles rely heavily on electronic control units (ECUs) that communicate via the controller area network (CAN) bus, a protocol developed in the 1980s with minimal security considerations. The growing number of ECUs has heightened the risk of cyberattacks on vehicles. Although CAN bus security has been extensively researched, the CAN standard still lacks built-in security measures. Furthermore, testing proposed security mechanisms is challenging due to the proprietary nature of automotive systems. To address this, an open-source physical testbed was developed using inexpensive, off-the-shelf components to support automotive CAN bus security research. The testbed provides a controlled environment for simulating …

Compositionally Complex Diborides: Competing Solubility During Sintering And Properties, Laura Silvestroni, Carlo Baldisserri, Jacopo Matteo Tabaglio, Nicola Gilli, Jeremy Watts, Steven M.I. Smith, Gregory E. Hilmas, William G. Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

An ultra-high temperature ceramic based on ZrB2, TiB2, and SiC was hot pressed to full density at 1850 °C. Addition of 5 vol% of different metal-compounds, in the form of HfC, VC, NbC or CrB2, increased the densification temperature to 1910 °C. The resulting compositionally complex ceramics had homogeneous microstructures with boride grains exhibiting core-shell features. The shell was a solid solution containing variable amounts of the three metals. Notably, TiB2 remained as a discrete phase in the reference material and in the presence of the V- and Cr- based additions, whilst it dissolved into the main ZrB2-based grains for …

Analysis Of Radial Inlet Distortion On Transonic Fan Performance, Tyler M. Reedy

Theses and Dissertations

Improving fan design and performance prediction requires an understanding of the impacts of inlet distortions. Inlet distortion describes any non-uniform distribution in the flow, usually referring to deviations in pressure and temperature. Using full annulus Unsteady Reynolds-Averaged Navier Stokes (URANS) simulations, the effects of both hub and tip radial distortions on the Air Force Research Lab (AFRL) Rotor 4 fan are analyzed. Overall performance, total pressure (Pt) distortion transfer, and total temperature (Tt) distortion generation are presented and compared for three operating points: near-stall, design, and choke. Hub radial inlet distortion magnitudes of 15% and 20%, and a tip radial …

Using Human Computation And Harmonic Expansions For Characterization And Design Of Grain Boundary Networks, Christopher W. Adair

Theses and Dissertations

Grain Boundary Networks (GBNs) are a high-dimensional feature in polycrystalline microstructural materials that are formed from the crystallographic degrees of freedom. This feature affects multiple material properties such as diffusivity, fracture, elasticity, heat transfer, and others. The link between the crystallography and the material properties is called the structure-property linkage, and allows for simulation and design of materials. While it is possible to use the structure-property linkage to design materials for better performance, the high-dimensional nature of the interconnected grain boundaries preclude the use of many common optimization algorithms for efficiency or local minima considerations. This work shows how the …

Modular Molecular Design Of Polymerized Pro-Estrogen Materials Enables Controlled Astrocyte Response, Devan L. Puhl, Alexis Ziemba, Samuel A.T. Ellman, Alex Hsu, Jayant Saksena, Penelope Phillips Falcone, Bailey Balouch, Deniz Rende, Tanner Fink, R. Helen Zha, Ryan J. Gilbert, Edmund F. Palermo

Chemical and Biochemical Engineering Faculty Research & Creative Works

The hormone 17β-estradiol (estrogen or "E2") has demonstrated robust neuroprotective properties in countering oxidative stress-induced neurotoxicity, as well as strong neurotrophic properties to promote axonal growth, following injury to the central nervous system (CNS). However, oral or injected E2 is a suboptimal drug, as systemic administration fails to achieve a therapeutic dose at the injury site, in addition to being contraindicated in most male patients. Polymerized pro-drug biomaterials can mitigate these issues by locally releasing small quantities of drug over vastly extended timescales. We sought to study the effect of the biomaterial properties of poly(pro-E2) on astrocyte-surface interactions because astrocytes …

Ute Mri For Assessing Demyelination In An Mtbi Mouse Model: An Open-Field Low-Intensity Blast Study, Yajun Ma, Qingbo Tang, Xin Cheng, Jiyo S. Athertya, David Coughlin, Eric Y. Chang, Catherine E. Johnson, Jiankun Cui, Zezong Gu, Jiang Du

Mining Engineering Faculty Research & Creative Works

Mild traumatic brain injury (mTBI) is a leading cause of long-term disability. Following mTBI, secondary chemical cascades and neuroinflammation can result in myelin damage, significantly impairing cognitive function. This study aims to assess demyelination in mice with mTBI induced by open-field low-intensity blast (LIB) using a novel three-dimensional short repetition time adiabatic inversion recovery UTE (3D STAIR-UTE) magnetic resonance imaging (MRI) sequence. Thirty male C57BL/6 mice, with 15 experiencing mTBI and 15 serving as sham controls, were included in this study. Behavioral tests were performed starting at 5 days post-injury to assess motor activity and anxiety-like responses followed by STAIR-UTE …

Numerical Simulation Of Heat Transfer In Self-Propagating High-Temperature Synthesis (Shs)-Based Calcination Of Limestone, Sayee Srikarah Volaity, Shubham Agrawal, Srinivas Kilambi, Patrick Phelan, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Calcination of limestone, a high temperature (∼900 °C) process that emits 44 % of the mass of limestone as CO₂, is a critical process in the production of many industrially important materials. To soften the CO₂-related impacts of traditional calcination, and to enable ultrafast synthesis of lime, a novel approach based on self-propagating high-temperature synthesis (SHS) has been put forward. SHS uses exothermic heat released by the combustion of fuel intermixed with the reactants to advance the reaction, and hence requires the provision of lower external temperatures. This study introduces a microstructure-guided modeling approach to understand …

Eyes On The Road: Disentagling Cyclist Mental Workload At Intersections, James Joseph Rawson

Civil Engineering ETDs

In North America, cyclists often share infrastructure with motor vehicles and encounter frequent conflicts with them at intersections. While past research assumes cyclists' experiences mirror those of drivers, most studies focus on roadway segments rather than intersections. This study addresses that gap by, for the first time we are aware of, examining cyclist perceptions at intersections using head and gaze movement data. Leveraging naturalistic data conducted in Albuquerque New Mexico, and statistical techniques, including t-test and repeated measures ANOVA, our findings suggest that – similar to drivers - cyclists do experience greater mental workload when performing turning movements than when …

Unleaded Aviation Fuel: Assessing Stakeholder Perceptions And Preparing An Organization For Change, Ryan Guthridge, Nicholas D. Wilson, Brandon Wild

Journal of Aviation Technology and Engineering

Since the Clean Air Act of 1996 banned the use of leaded fuel for automotive applications, leaded aviation gasoline (AVGAS) has become one of the leading sources of lead pollution in the nation due to the volume of AVGAS consumed in general aviation applications (GAMA, 2019). The Federal Aviation Administration has recently recognized this concern with the establishment of the Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative, which was formally established in February 2022 to foster an important campaign to research and inform the general aviation community on the process for transitioning to unleaded AVGAS. This essay seeks to inform …

Antenna Analysis Using Mixed Computer Platforms (Aacp), Keith H. Bova

Electrical and Computer Engineering ETDs

This thesis reviews the design, implementation, and benchmarking of commercially available, previous generation (CAPG) computer systems, and how they can be used with computational electromagnetics. The thesis focuses on their architecture, performance, and practical applications. It begins with an overview of CAPG system components, including different node types such as login/controllers, compute nodes, block storage, and object storage. The process of assembling these systems is outlined. The conjugate gradient method and direct linear solvers were benchmarked. The performance of CAPG systems is compared with modern computing architectures. A detailed analysis provides recommendations for designing CAPG systems around the performance of …

A Dynamically Efficient Predictive Controller For Voltage Stability In A Dc To Dc Boost Converter, Giovanni Reyna

Electrical and Computer Engineering ETDs

Reliable voltage regulation has become a critical issue with increase demand in modern power electronic applications. This study presents a Model Predictive Controller (MPC) for voltage regulation in DC-to-DC boost converters. A closed loop analytical MPC framework is created with the purpose of computing optimal duty cycles to maintain a stable output voltage under varying load conditions, input changes, and disturbances.

To evaluate the performance of the MPC we set the controller against a comparative analyzing with a traditional cascading proportional integral (PI) controller. The proposed controller design is specifically targeted to improve dynamic efficiency during the converter’s transient events. …

Two-Layer Formulation For Long-Runout Turbidity Currents: Theory And Bypass Flow Case, Hongbo Ma, Gary Parker, Matthieu Cartigny, Enrica Viparelli, S. Balachandar, Xudong Fu, Rossella Luchi

Faculty Publications

Turbidity currents, which are stratified, sediment-laden bottom flows in the ocean or lakes, can run out for hundreds or thousands of kilometres in submarine channels without losing their stratified structure. Here, we derive a layer-averaged, two-layer model for turbidity currents, specifically designed to capture long-runout. A number of previous models have captured runout of only tens of kilometres, beyond which thickening of the flows becomes excessive, and the models without a lateral overspill mechanism fail. In our framework, a lower layer containing nearly all the sediment is a faster, gravity-driven flow that propels an upper layer, where sediment concentration is …

An Analysis Of The Encryption Algorithms Proposed For The Mqtt Protocol On Resource Constrained Iot Devices, John Joseph Keenan

Theses and Dissertations

As more IoT devices are used to gather data and automate devices throughout the world, more security solutions are needed to keep these devices and the data they transmit secure. Many of these devices use the MQTT protocol, which does not encrypt the transferred data by default. The TLS/SSL protocols are the standard proposed solution for encrypting this traffic, but many resource constrained IoT devices do not have enough resources to run these protocols efficiently. Because of this, many other encryption algorithms have been proposed or designed for resource constrained IoT devices running the MQTT protocol, but very limited research …

The Development Of Electroanalytical Methods For Molten Salt Mixtures Under Static And Flowing Conditions, Ranon Fuller

Theses and Dissertations

Electroanalytical methods have the potential to characterize molten salt systems in situ, determine physical properties such as diffusion coefficients and standard potentials, and measure kinetic and corrosion rates. Due to experimental difficulties of working with molten salts including high temperatures and high natural convection, transport, kinetic, and corrosion rates, many precise, consistent methods have yet to be established. In this work, we describe methods to precisely calculate standard reduction potentials, characterize molten salt solutions containing multiple lanthanides by reduction potentials and metal deposition mechanisms, calculate the number of electrons exchanged in metal deposition using SWV, calculate diffusion coefficients using CV, …

Ultrahigh Electric Charge Density Harvested From Pre-Compressed Ferroelectric Ceramics, Sergey I. Shkuratov, Jason Baird, Alexander S. Shkuratov, Christopher S. Lynch

Mining Engineering Faculty Research & Creative Works

Ferroelectric elements of high-power electrical generators, utilizing the ability of ferroelectric materials to produce electric charge under mechanical stress, are subjected to either high-pressure shock or moderate-pressure impact loading. The results are reported herein on experimental investigations of a different mode for the generation of a high electric charge density, one that utilizes pre-compressed ferroelectric ceramics. Hard PZT 52/48 (Navy Type I/PZT-4) ferroelectric ceramic specimens were subjected to static uniaxial compressive stress parallel to polarization. At the moment of operation, the output terminals of the specimens were connected to an external circuit, and the applied stress was quickly removed, resulting …

Aerosol Technology For Carbon Capture And Utilization, Onochie Chinedum Okonkwo

McKelvey School of Engineering Graduate Student Theses & Dissertations

The CO2 concentration in the atmosphere has continued to increase over the past century and now poses an increasing potentially catastrophic effect to human life and the environment via global warming and the concomitant effect of climate change. Anthropogenic carbon dioxide emissions due to fossil fuel combustion for increasing energy demand is the main driver for the increased carbon dioxide in the atmosphere. A multifaceted approach including carbon dioxide capture and utilization is required to mitigate anthropogenic carbon dioxide emissions. Aerosol science and technology, an enabler for clean combustion technologies and nanomaterial synthesis, can contribute significantly to the advancement of …

Sustained Release Of Antifibrotic Nintedanib From Polymer Microparticles Reduces Dosing Frequency While Reducing Inflammation In Murine Idiopathic Pulmonary Fibrosis, Emmanuel Einyat Opolot, Filip Goshevski, Rahul Chaudhary, Horst A. Von Recum, Amar B. Desai

Faculty Scholarship

Purpose: Idiopathic pulmonary fibrosis (IPF) is a life-threatening, progressive lung disease with limited therapeutic options, often resulting in poor patient outcomes. Current treatments, such as Nintedanib (NTB) and Pirfenidone (PFD), require frequent administration, leading to adverse effects and low patient adherence. The purpose of this study was to investigate a sustained-release drug delivery system utilizing microparticles (MPs) composed of insoluble beta-cyclodextrin (β-CD) polymers to enhance the bioavailability and extend the release of NTB and PFD. Methods: A multidisciplinary approach, including in silico modeling, in vitro assays, and in vivo studies, was employed to assess the efficacy of β-CD-polymer MPs as …

Average Biomechanical Responses Of The Human Brain Grouped By Age And Sex, Ahmed A. Alshareef, Aaron Carass, Yaun-Chiao Lu, Joy Mojumder, Alexa M. Diano, Olivia M. Bailey, Ruth J. Okamoto, Dzung L. Pham, Jerry L. Prince, Philip V. Bayly, Curtis L. Johnson

Faculty Publications

Traumatic brain injuries (TBIs) occur from rapid head motion that results in brain deformation. Computational models are typically used to estimate brain deformation to predict risk of injury and evaluate the effectiveness of safety countermeasures. The accuracy of these models relies on validation to experimental brain deformation data. In this study, we create the first group-average biomechanical responses of the brain, including structure, material properties, and deformation response, by age and sex from 157 subjects. Subjects were sorted intro three age groups—young, mid-age, and older—and by sex to create group-average neuroanatomy, material properties, and brain deformation response to non-injurious loading …

Electric Field Profiles Under High Voltage Overhead Transmission Lines With Under-Build Distribution Circuit, Aminu Haruna

Electrical Engineering Theses

The increasing use of underbuilt lines in recent transmission projects alters electric field profile under transmission lines. By assessing electric field intensity in these transmission and distribution network configurations, the study identifies regions with high electric fields that may exceed standard exposure limits, posing potential risks. This work employs the charge simulation method and the method of imaging to analyze electric fields beneath transmission lines with underbuilt distribution networks. Key objectives include calculating the electric fields at 1 meter above ground, and evaluating the field at conductor surfaces. The study considers transmission line voltages of 69kV, 161kV, 220kV, 345kV and …

Cyber Physical Emulation Of Power Grids: Co-Simulation Of Exata Cps And Hypersim, Mckayla Snow

Electrical and Computer Engineering ETDs

This thesis explores the use of cyber-physical emulation of power grids to analyze the impact of different types of cyberattacks. It outlines the co-simulation process of HYPERSIM and EXata CPS within the OPAL-RT real-time digital simulator, demonstrating various cyberattacks on two power system models. The first model is a simple communication-focused testbed for easy demonstration of co-simulation setup, while the second is a power system model of a secondary network used to assess the cybersecurity of network protector units in low-voltage networks through a hardware-in-the-loop (HIL) testbed. Using this testbed, the cybersecurity of the direct transfer trip (DTT) scheme is …

Examining Physiological Responses To Misophonic Triggers, Christian O'Reilly, Xuan Yang, Sewon Oh, Doug Wedell, Svetlana Shinkareva

Faculty Publications

We collected and analyzed an array of biosignals (face electromyogram, skin electrodermal activity, peripheral temperature, and electrocardiogram) in 60 participants with and without misophonia, a condition characterized by decreased tolerance to innocuous sounds. Our goal was to objectively characterize the physiological response to misophonia triggering sounds. We found that misophonic responses can be objectively identified in some cases through atypical physiological reactions to triggering stimuli, though not all participants exhibited this response. Our analyses suggest a large interindividual variability in response to misophonic triggers and highlights the need for methodological adjustments in future experiments to increase the detectability of misophonic …

Removing Eog Artifacts From Eeg Recordings Using Deep Learning, Christian O'Reilly, Scott Huberty

Faculty Publications

The electroencephalogram (EEG) directly measures the electrical activity generated by the brain. Unfortunately, it is often contaminated by various artifacts, notably those caused by eye movements and blinks (EOG artifacts). Such artifacts are usually removed using an independent component analysis (ICA) or other blind source separation techniques. However, it is difficult to assess whether subtracting EOG components estimated through ICA removes some neurogenic activity. It is crucial to address this question to avoid biasing EEG analyses. Toward that objective, we developed a deep learning model for EOG artifact removal that exploits information about eye movements available through eye-tracking (ET). Using …

A Reliable And Efficient Detection Pipeline For Rodent Ultrasonic Vocalizations, Sabah Shahnoor Anis, Devin Mark Kellis, Kris Ford Kaigler, Marlene A. Wilson, Christian O'Reilly

Faculty Publications

Analyzing ultrasonic vocalizations (USVs) is crucial for understanding rodents' affective states and social behaviors, but the manual analysis is time-consuming and prone to errors. Automated USV detection systems have been developed to address these challenges. Yet, these systems often rely on machine learning and fail to generalize effectively to new datasets. To tackle these shortcomings, we introduce ContourUSV, an efficient automated system for detecting USVs from audio recordings. Our pipeline includes spectrogram generation, cleaning, pre-processing, contour detection, post-processing, and evaluation against manual annotations. To ensure robustness and reliability, we compared ContourUSV with three state-of-the-art systems using an existing open-access USV …