Engineering Commons^™

Investigations Of Prokaryotic Defense Systems, Hannah Domgaard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bacteria are constantly threatened with infection by mobile genetic elements (MGE) such as bacteriophage and plasmids. Bacteriophage and plasmids require the bacteria's cellular infrastructure to replicate their genomes. Rampant replication can lead to cell death which is one reason why bacteria have developed a diverse array of immune systems to prevent or limit infection. This thesis studies three types of bacterial immune systems, type IV-A CRISPR-Cas (Clustered Regularly Interspaced Short Palindromic Repeat –CRISPR associated), type V-A2 CRISPR-Cas systems, and Wadjet systems.

The type IV-A system lies adjacent to a dinG-like helicase gene. Research has shown that this system can target …

Linearized Rigid-Body Static And Dynamic Stability Of An Aircraft With A Bio-Inspired Rotating Empennage, Austin J. Kohler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The United States Air Force (USAF) will likely seek to remove the vertical tail of next-generation fighter aircraft. This work seeks to characterize the static and dynamic stability and handling qualities of a vertical-tailless aircraft concept that would satisfy the USAF’s goal. This concept aircraft, one modified with a Bio-Inspired Rotating Empennage (BIRE), does not have a vertical tail, and is instead capable of rotating the horizontal tail about the fuselage axis for maneuvering. The dynamic characteristics of the BIRE-modified aircraft are compared to a baseline unmodified aircraft, similar to the F16, with a traditional vertical tail. Linearized aerodynamic models …

Lifting-Line Predictions For Life And Twist Distributions To Minimize Induced Drag In Ground Effect, Kyler Church

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The elliptic lift distribution produces the minimum induced drag for a given wingspan and desired lift outside of ground effect. This distribution can be generated on any wing by using geometric and/or aerodynamic twist. However, in ground effect, the elliptic lift distribution is not necessarily that which minimizes induced drag. The present work uses a modern numerical lifting-line algorithm to evaluate how the optimum lift distribution varies as a function of height above ground. The algorithm is also used to obtain the twist distributions that should be applied to wings of varying aspect ratios and taper ratios to produce the …

A Theoretical Trade-Off Between Wave Drag And Sonic Boom Loudness Due To Equivalent Area Changes On A Supersonic Body, Nolan L. Dixon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The NASA University Leadership Initiative (ULI) titled ”Adaptive Aerostructures for Revolutionary Civil Supersonic Transportation” consists of a team of university and industry partners studying the feasibility of reducing the perceived loudness of the sonic boom by introducing an adaptive geometry at localized regions of an aircraft’s outer-mold line. The Utah State University AeroLab is a member of this ULI team and has produced low-fidelity tools to predict the aerodynamic and boom loudness effects from localized changes to the geometry.

Such changes to the geometry affect both the sonic boom loudness and wave drag; however, the precise relationship between boom loudness …

Multi-Fidelity Predictions For Control Allocation On The Nasa Ikhana Research Aircraft To Minimize Drag, Justice T. Schoenfeld

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Optimal control settings (camber scheduling) can be used by aircraft to minimize drag at various operating conditions during flight. In this work, camber schedules for minimum drag on the NASA Ikhana are obtained over a range of lift coefficients. A modern numerical lifting-line algorithm is used to predict the lift and drag of the aircraft as a function of operating condition and wing section shape (airfoil camber). The SLSQP optimization algorithm is used to solve for the camber schedule that minimizes drag for a given operating condition. The process is repeated, varying the number of control sections to evaluate the …

Characterizing Karst Mountain Watersheds Through Streamflow Response To Snowmelt, Daniel Meade Thurber

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The climate in many parts of the Western US is characterized by cold, wet winters preceding long, dry summers. In the absence of precipitation, water supplies in these regions are sustained by melting snow and mountain groundwater. Changes in regional climate can reduce snow accumulation, accelerate melt, and prolong dry periods, all increasing the importance of groundwater on summertime water availability. In mountainous regions with limestone and dolomite geology, bedrock formations can host significant karst aquifers comprising dissolution-enhanced karst conduits which play an outsized and variable role in how precipitation is translated into streamflow. In this study, we considered an …

Developing A Methane Detector For Aerospace Applications, Michael A. Kirk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greenhouse gasses in the atmosphere are raising the global temperature and causing adverse side effects. Of these greenhouse gasses, methane is one of the most impactful, second only to carbon dioxide. One of the methods for determining the concentration of methane in the atmosphere is taking images of the earth from space. The purpose of this project is to further a new imaging technology for detecting methane leaks called FINIS (Filter Incidence Narrow-band Infrared Spectrometer), thus improving our capability to detect and locate methane leaks and reduce greenhouse gas emissions. FINIS has been developed in various stages since 2018 and …

Low Resource Assay For Tracking Sars-Cov-2 In Wastewater, Julissa Van Renselaar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wastewater based epidemiology (WBE) allows for the tracking of nucleic acid of SARS-CoV-2 in wastewater which gives the opportunity for the public and government officials to be informed about the infectivity of the virus in a community. Advances have been made in WBE that have allowed for higher performance, lower resource use, and faster turnaround time. An adapted concentration method of spin column direct extraction has yielded a proxy virus recovery of 83%, consumable cost of $2.01 per sample, and a turnaround time of 0.33 hour/sample. Other concentration methods have lower proxy virus recoveries, comparable cost, and comparable turnaround time. …

Numerical Modeling And Simulating Thermal Performance Of Printed Circuit Boards, Paul R. Ziegenfelder

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research investigates how heat transfer theory can be applied to evaluate the thermal performance of printed circuit board (PCB) designs. A model was developed for correlating theory to the physical parameters relating to the construction of the PCB and a computer application was developed to perform the thermal analysis. The application allows the importation of common PCB design files for a straightforward and quick analysis of a PCB design’s thermal performance. The application is open-source to allows for further development and free access from the public.

Event-Based Obstacle Detection With Commercial Lidar, Chaz Cornwall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Computerized obstacle detection for moving vehicles is becoming more important as vehicle manufacturers make their systems more autonomous and safe. However, obstacle detection must operate quickly in dynamic environments such as driving at highway speeds. A unique obstacle detection system using 3D changes in the environment is proposed. Furthermore, these 3D changes are shown to contain sufficient information for avoiding obstacles. To make the system easy to integrate onto a vehicle, additional processing is implemented to remove unnecessary dependencies. This system provides a method for obstacle detection that breaks away from typical systems to be more efficient.

Modeling And Control Of Battery Management Systems With High-Frequency Ac Link Coupled Multiport Series Resonant Converters For 2nd Life Battery Applications, Brooks Jace Maughan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

While the use and production of Electric Vehicles becomes more prevalent, it is also important to make this economical and ensure the reduction of a carbon footprint. Second-life batteries can satisfy both problems as batteries can be used in a second-life application for lower power purposes such as supplementing the grid so the infrastructure needed to charge the expanding fleet of Electric Vehicles can be easily supplied. This thesis goes through the process of Active Cell Balancing which will produce equal capacities, or similar batteries, that can be more efficiently used in these and other types of second-life applications. The …

Path Planning For Aircraft Under Threat Of Detection From Ground-Based Radar With Uncertainty In Aircraft And Radar States, Austin D. Costley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mission planners for manned and unmanned aircraft operating within the detection range of ground-based radar systems are often concerned with the probability of detection. Several factors influence the probability of detection, including aircraft position and orientation, radar position, and radar performance parameters. Current path planning algorithms assume that these factors are known with certainty, but in practice, these factors are estimated and have some uncertainty.

This dissertation explores methods to consider the uncertainty in the detection factors for an aircraft path planner. First, the detection model is extended to include uncertainty in the aircraft position and orientation, radar position, and …

Design Of Environment Aware Planning Heuristics For Complex Navigation Objectives, Carter D. Bailey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A heuristic is the simplified approximations that helps guide a planner in deducing the best way to move forward. Heuristics are valued in many modern AI algorithms and decision-making architectures due to their ability to drastically reduce computation time. Particularly in robotics, path planning heuristics are widely leveraged to aid in navigation and exploration. As the robotic platform explores and navigates, information about the world can and should be used to augment and update the heuristic to guide solutions. Complex heuristics that can account for environmental factors, robot capabilities, and desired actions provide optimal results with little wasted exploration, but …

Energy Dissipation Of Highly Convergent Chutes In Stilling Basins Of Concrete Dams, Rafael Morán, Miguel Ángel Toledo, Jaime I. Masides

Protections Conference

This article presents the results of a combination of experimental and numerical research on the performance of stilling basins of spillways with highly convergent chutes (HCC). The comparison between the energy dissipation of the stilling basins with flat slab and baffle blocks shows that the latest are more efficient. Because of that, the cost savings of using such blocks can be significant. The results obtained could be applied in different cases such as increasing the capacity of existing spillways and protecting dams against overtopping. The application of HCC spillways in new dams could lead to a reduction in the cost …

A Novel Computational Method To Compute Rock Scour Due To Dam Overtopping, Erik F. R. Bollaert

Protections Conference

Flood events generating potential risk for dam overtopping may become more frequently in the future, especially because of increasing climate change. Crest overflows at arch dams generally impact the downstream rock mass very close to the dam foundation. As such, any scour of the rock mass generated by this phenomenon may potentially endanger the stability of the dam and its appurtenant structures. Hence, pertinent assessment of this scour formation through space and time is becoming increasingly relevant to dam safety. This paper presents a novel computational method for detachment of prismatic rock blocks from their mass when impacted by high-velocity …

Bedrock Erosion In Swedish Spillways - A Methodology For Assessing Design Pore Pressures Aimed For Design Of Erosion Mitigation Via Reinforcement Of The Rock Mass, Per Eriksson, Jonas Persson, Carol-Oscar Nilsson

Protections Conference

This article presents a collection of literature and data that enables calculations of hydraulic pressures inside a structurally simplified rock mass. The causation between the pressure in the rock mass and the near plane-parallel turbulently flowing waters on natural surfaces of igneous rock is expressed. The article is mainly aimed at rock reinforcement calculations given magmatic rock types with high durability and large block size.

Erodibility Evaluation Of An Unlined Rock Spillway: Comparison Between The Erodibility Index Method And A New Method Based On Block Theory, Michael George, Cole Christiansen, Ariel Rickel, Benjamin Israel, George W. Annandale

Protections Conference

Following the 2017 events at the Oroville Dam spillways that prompted evacuation of nearly 200,000 downstream residents and resulted in over $1B USD repair costs, there is highlighted focus on evaluation of spillways (both lined and unlined) at dams across the USA. In the case of unlined channels, flow conditions are often complex which presents several challenges for erodibility evaluation given methods are often based on idealized circumstances. High-resolution data available for the site (both in terms of 3D point cloud geometry data for the rock mass and 3D CFD model simulations of flow conditions) permitted a more detailed analysis …

Hydro-Geotechnical Rock Scour Assessment At Petit-Saut Dam, Seven E. Pells, Fanar Al-Qassab, Felicia Weir, Anaïs Faivre, Thierry Leturcq, Benoit Blancher

Protections Conference

This paper presents a recommended design procedure for assessment of rock scour which is illustrated for the case study of Petit-Saut Dam in French Guiana. The methodology, referred to as a “hydro-geotechnical scour assessment”, promotes a multi-discipline approach, applying expertise in both rock mechanics and hydraulics, and guides the diagnosis of scour and response to risk by application of currently available scour assessment techniques.

Failure Thresholds For Rcc Crest Caps, Tony L. Wahl, Bryan J. Heiner, Jacob F. Kepler

Protections Conference

Overtopping protection using roller-compacted concrete (RCC) overlays is a common improvement made to address hydrologic deficiencies at existing small- to medium-height embankment dams. Overlays allow floods to pass over the dam while preventing erosion of the original embankment. The United States has many examples of such projects on both private and public dams, including many associated with federal agencies of the Departments of the Interior and Agriculture. For one project modified with an overlay in 1993, deterioration of the RCC and poor bonding between lifts has caused concern for stability of the 0.3-m (1-ft) thick RCC lifts that cap the …

First Application Of Articulated Concrete Block Armoring With A Stabilized Stone Drainage Layer, Jeremy R. Young, Jim Nadeau

Protections Conference

Results from recent hydraulic testing of Articulated Concrete Block (ACB) systems have shown variations in the level of the ACB surface is attributed to the movement of an unconfined stone drainage layer. This movement appears to be exacerbated by thicker drainage layers, higher overtopping depths, and longer test flumes. While the apparent movement did not constitute “threshold of performance” as currently defined by ASTM D7276 and D7277, there was a desire to mitigate movement of the stone drainage layer and maintain conservatism in ACB design and construction. This paper will review the findings of Nadeau and Wedin’s paper from Protections …

Applying The Submerged Jet Erosion Test To Embankment Dam Breach Modeling, Tony L. Wahl, Blake Armstrong

Protections Conference

The submerged jet erosion test (JET) is one of several methods available for quantifying erodibility of cohesive soils, a crucial input for modeling erosion and breach of embankment dams with models such as WinDAM, EMBREA (Morris 2011), and DL BREACH (Wu 2013; 2016a; 2016b). The JET was initially developed in the late 1980s as a relatively large-scale device with a 13-mm diameter nozzle creating an impinging jet that erodes a soil sample submerged in a 61-cm diameter tank. This first device was documented in an ASTM standard (D5852-1995), but the standard was withdrawn in 2016. In the last 15 to …

Structural Failure Of The Cohesive Core Of Rockfill Dams: An Experimental Research Using Sand-Bentonite Mixtures, Ricardo Monteiro-Alves, Rafael Moran, Miguel Á. Toledo, Javier Peraita

Protections Conference

This article presents experimental research focusing on the structural failure of the central core of a rockfill dam using sand-bentonite mixtures. It comprised an extensive geotechnical characterization of soil materials and mixtures, including compaction and strength tests, as well as the construction of 1 m high and 1.5 m wide physical models. The displacements of the cohesive cores were recorded using a tailored measuring system, based on a laser pointer and a mirror, designed to amplify the real displacements. The cohesive cores were extremely sensitive to small oscillations and behaved as rigid bodies, similar to concrete slabs with three fixed …

Overtopping Erodibility Analysis For A Steep-Sloped Rockfill Embankment Dam, Ariel Rickel, Michael F. George, Rob Millar

Protections Conference

Erosion of embankment material during an overtopping event is one of the major mechanisms of failure for earthfill dams. The ability to analyze the progression of overtopping failure can prove useful in assessing the breakthrough risk of the dam, which involves understanding the behavior of the material that the dam is comprised of. While there have been studies on the behavior of smaller-grained materials such as clays and sands (e.g. Hahn et al 2000; Coleman et al. 2002; Hanson et al. 2005; Hanson et al. 2011), few have focused on erosion of larger-grained rockfill embankments.

This paper presents the erosion …

Study Into The Sensitity Of The G-H Method To Blending Distance, Cory Goates, Doug Hunsaker

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A numerical lifting-line method (implemented in an open-source software package) is presented which can accurately estimate the aerodynamics of wings with arbitrary sweep, dihedral, and twist. Previous numerical lifting-line methods have suffered from grid convergence challenges and limitations in accurately modeling the effects of sweep, or have relied on empirical relations for swept-wing parameters and have been limited in their application to typical wing geometries. This work presents novel improvements in accuracy, flexibility, and speed for complex geometries over previous methods. In the current work, thin-airfoil theory is used to correct section lift coefficients for sweep, providing a more general …

Multiple Discharges Before Leader Inception In Long Air Gaps Under Positive Switching Impulses, Xiangen Zhao, Juhyeong Lee, Gang Liu, Lei Jia, Yang Liu, Junjia He, Yaping Du

Mechanical and Aerospace Engineering Faculty Publications

There are multiple corona bursts before leader inception when the rising rate of the applied voltage or electric field is not sufficiently high enough in long positive sparks. In existing studies, no attention has been paid to whether these corona bursts occur in the same location, and they are mostly considered directly as belonging to the same discharge. However, this paper presents that in a typical rod-plate long air gap, the multiple corona bursts before leader inception are distributed in at least two different locations, and the highest probability of three discharges occurs. Also, the discharge occurs with the highest …

Sustaining Water Conservation: A Synthesis Of Research On Motivators, Message Construction, And Tactics, Mahmudur R. Aveek, David E. Rosenberg

Civil and Environmental Engineering Student Research

Urban water managers face the challenge of sustaining conservation behavior. A review of 77 papers across water, energy, and environmental conservation was conducted to understand how programs encourage reduced water use. Motivators were external or internal. Theories of behavior change targeted different social-psychological factors. No single model addressed all aspects. Different message contents (water use, self-comparison, social comparison, leak information) and tactics (communication medium, frequency, program duration) reduced use by 0.5% to 25%. Reductions typically lasted less than a year. Quantifying the effects of specific motivators, message contents, and tactics was difficult due to varied contexts. Effective conservation messages included …

Pace Oci Short-Wave Infrared Detection Assembly Frequency-Dependent Linearity Characterization And Uncertainty Analysis, Kenneth J. Squire, Jacob Hedelius, David K. Moser, James Q. Peterson, Eric T. Gorman, Emily Kan, D. Brent Mott, Ulrik B. Gliese, Gerhard Meister

Space Dynamics Laboratory Publications

The Ocean Color Instrument (OCI), the primary payload of the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) observatory, will collect data to monitor the health of Earth’s oceans and atmosphere. The Short-Wave Infrared (SWIR) Detection Assembly (SDA) was built and characterized by the Utah State University Space Dynamics Laboratory (SDL) and is a subsystem of OCI. The SDA measures seven bands centered at 940, 1038, 1250, 1378, 1615, 2130, and 2260 nm, with standard- and high-gain varieties for the 1250 and 1615 nm bands, resulting in nine total detection configurations in the SWIR. The delivery of high-quality science data is critically …

Infrared Spectral Responses Of The Ocean Color Instrument (Oci) Pre-Assembly And Integration, Jacob K. Hedelius, Kenneth J. Squire, James Q. Peterson, Branimir Blagojević, Ulrik B. Gliese, Eric T. Gorman, David K. Moser, Zakk Rhodes, Pedro Sevilla, Gerhard Meister

Space Dynamics Laboratory Publications

Spectral characterizations were made of the Ocean Color Instrument (OCI) short-wave infrared (SWIR) Detection Subassembly (SDS) responses (940–2260 nm) prior to their integration. Using modulated output light from a Fourier transform spectrometer, the in-band relative spectral responses of the nine different configurations of SDSs were found along with out-of-band (OOB) sensitivity. From these spectral responses, the center wavelengths (λ₀), full widths at half of the maximum, full widths at 1% of the maximum, and OOB rejection ratios were determined. All spectral parameters are within requirements. There are 2–8 repeats of each configuration, and the 1 σ spread among …

Design Of Composite Double-Slab Radar Absorbing Structures Using Forward, Inverse, And Tandem Neural Networks, Devin Nielsen, Juhyeong Lee, Young-Woo Nam

Mechanical and Aerospace Engineering Faculty Publications

The survivability and mission of a military aircraft is often designed with minimum radar cross section (RCS) to ensure its long-term operation and maintainability. To reduce aircraft’s RCS, a specially formulated Radar Absorbing Structures (RAS) is primarily applied to its external skins. A Ni-coated glass/epoxy composite is a recent RAS material system designed for decreasing the RCS for the X-band (8.2 – 12.4 GHz), while maintaining efficient and reliable structural performance to function as the skin of an aircraft. Experimentally measured and computationally predicted radar responses (i.e., return loss responses in specific frequency ranges) of multi-layered RASs are expensive and …

Hyper-Velocity Impact Performance Of Foldcore Sandwich Composites, Nathan Hoch, Chase Mortensen, Juhyeong Lee, Khari Harrison, Kalyan Raj Kota, Thomas Lacy

Mechanical and Aerospace Engineering Faculty Publications

A foldcore is a novel core made from a flat sheet of any material folded into a desired pattern. A foldcore sandwich composite (FSC) provides highly tailorable structural performance over conventional sandwich composites made with honeycomb or synthetic polymer foam cores. Foldcore design can be optimized to accommodate complex shapes and unit cell geometries suitable for protective shielding structures

This work aims to characterize hypervelocity impact (> 2000 m/s, HVI) response and corresponding damage morphologies of carbon fiber reinforced polymer (CFRP) FSCs. A series of normal (0° impact angle) and oblique (45° impact angle) HVI (~3km/s nominal projectile velocity) impact …