Engineering Commons^™

Development Of An Anisotropic Thermal Stress Model For A Low-Erosion Hybrid Rocket Nozzle System, Judson C. Stephens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hybrid rockets are rockets which employ a solid fuel grain with a liquid oxidizer. Hybrids have many promising potential applications, however they also have a few drawbacks. Of interest to this research is the increased rate of nozzle erosion inherent to hybrid rockets. In order to address this issue, a low-erosion nozzle is proposed and evaluated.

Evaluation Of Bioretention Performance In Northern Utah As A Function Of Media, Vegetation, And Loading, Trixie Rife

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pollutants found in stormwater runoff are a growing environmental concern. The EPA has identified bioretention (BR) systems as a best management practice for the control of pollutants in stormwater runoff. BR systems reduce pollutant loads discharged to surface water bodies and to lower pollutant concentrations of water infiltrating into underlying groundwater. However, knowledge of the performance of BR systems in semi-arid Western climates is lacking. This study was conducted at three field sites in Northern Utah to evaluate the effectiveness of various natural and engineered media and various plant species on pollutant removal subjected to a range of pollutant loadings …

Concrete Maturity Method Applied To Rapid-Setting Calcium-Sulfoaluminate (Csa) Concretes For Pavement Repair Under Different Ambient Temperatures, Ryan Nicholas Langford

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With more and more people using roadways the need for fast and efficient repair work is becoming increasingly important. Lane closures impede traffic flow and result in congestion. To further limit the amount of time lane closures are needed for repair work, calcium sulfoaluminate (CSA) cement concrete has become an increasing popular construction material for its ability to reach adequate strength requirements within four hours. Because of this accelerated repair time, advanced testing methods are needed to verify that the replaced concrete does indeed meet or exceed the minimum compressive strength requirements.

The maturity method is one test used to …

Surrogate Optimization Model For An Integrated Regenerative Methanol Transcritical Cycle, Yili Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In order to reduce the cost ($) per megawatts hour (MWh) of electrical energy generated by a nuclear power cycle with a novel small modular reactor (SMR), a new SMR-based nuclear power cycle with Methanol as working fluid was designed. It was built virtually with the Python & Coolprop software based on all components’ physical properties, and it is therefore called the physics-based model. The physics-based model would require seven user-defined values as input for the seven free design parameters, respectively. The physics-based model outcomes include LCOE (the cost per megawatts hour of electrical energy generated by the …

Vortex-Oriented Ferroelectric Domains In Snte/Pbte Monolayer Lateral Heterostructures, Kai Chang, John W. D. Villanova, Jing-Rong Ji, Souvik Das, Felix Kuster, Salvador Barraza-Lopez, Paolo Sessi, Stuart S. P. Parkin

Physics Faculty Publications and Presentations

Heterostructures formed from interfaces between materials with complementary properties often display unconventional physics. Of especial interest are heterostructures formed with ferroelectric materials. These are mostly formed by combining thin layers in vertical stacks. Here the first in situ molecular beam epitaxial growth and scanning tunneling microscopy characterization of atomically sharp lateral heterostructures between a ferroelectric SnTe monolayer and a paraelectric PbTe monolayer are reported. The bias voltage dependence of the apparent heights of SnTe and PbTe monolayers, which are closely related to the type-II band alignment of the heterostructure, is investigated. Remarkably, it is discovered that the ferroelectric domains in …

Wavelength And Power Dependence On Multilevel Behavior Of Phase Change Materials, Gary A. Sevison, Joshua A. Burrow, Haiyun Guo, Andrew M. Sarangan, Joshua R. Hendrickson, Imad Agha

Electro-Optics and Photonics Faculty Publications

We experimentally probe the multilevel response of GeTe, Ge2Sb2Te5 (GST), and 4% tungsten-doped GST (W-GST) phase change materials (PCMs) using two wavelengths of light: 1550 nm, which is useful for telecom-applications, and near-infrared 780 nm, which is a standard wavelength for many experiments in atomic and molecular physics. We find that the materials behave differently with the excitation at the different wavelengths and identify useful applications for each material and wavelength. We discuss thickness variation in the thin films used as well and comment on the interaction of the interface between the material and the substrate with regard to the …

The Facility Infection Risk Estimator™: A Web Application Tool For Comparing Indoor Risk Mitigation Strategies By Estimating Airborne Transmission Risk, Marcel Harmon, Josephine Lau

Durham School of Architectural Engineering and Construction: Faculty Publications

The COVID-19 pandemic created needs for (a) estimating the existing airborne risk of infection from SARS-CoV-2 in existing facilities and new designs and (b) estimating and comparing the impacts of engineering and behavioural strategies for contextually reducing that risk. This paper presents the development of a web application to meet these needs, the Facility Infection Risk Estimator™, and its underlying Wells–Riley based model. The model specifically estimates (a) the removal efficiencies of various settling, ventilation, filtration and virus inactivation strategies and (b) the associated probability of infection, given the room physical parameters and number of individuals infected present with either …

Interior Point Optimization Of Low-Thrust Spacecraft Trajectories, Jordan D. Frederiksen

Master's Theses

Low-thrust interplanetary spacecraft trajectory optimization poses a uniquely difficult problem to solve because of the inherent nonlinearities of the dynamics and constraints as well as the large size of the search space of possible solutions. Tools currently exist that optimize low-thrust interplanetary trajectories, but these tools are rarely openly available to the public, and when they are available they require multiple interfaces between multiple different packages. The goal of this work is to present a new piece of low-thrust interplanetary spacecraft trajectory optimization software that is open-source and entirely self-contained so that more people can have access to the ability …

Subclinical Atherosclerosis Quantified Through Cumulative Shear Measurement, Margaret Lynne Papka

Master's Theses

With the high mortality rate of cardiovascular disease, it is important to study the early signs. The early detection of cardiovascular disease can lead to saved lives. Currently the most prevalent detection methods are the Framingham Risk Score and the carotid intima media thickness, both of which are insufficient. The necessary tool for early detection requires a uniform quantification system. The stimulus leading to endothelial dysfunction, the most significant predictor of a major adverse cardiovascular event (MACE)—and subsequently subclinical atherosclerosis—is reduced shear stress. Increased surface relative roughness affects the flow profile transition from laminar to turbulent resulting in reduced shear …

Snr: Software Library For Introductory Robotics, Spencer F. Shaw

Master's Theses

This thesis introduces "SNR," a Python library for programming robotic systems in the context of introductory robotics courses. Greater demand for roboticists has pressured educational institutions to expand robotics curricula. Students are now more likely to take robotics courses earlier and with less prior programming experience. Students may be attempting to simultaneously learn a systems programming language, a library API, and robotics concepts. SNR is written purely in Python to present familiar semantics, eliminating one of these learning curves. Industry standard robotics libraries such as ROS often require additional build tools and configuration languages. Students in introductory courses frequently lack …

Nonlinear Model Development And Validation For Ball And Plate Control System, Zachary Richter

Master's Theses

Ball and plate balancing control systems are commonly studied due to the complex dynamics associated with the instability of the system in open-loop. For simplicity, mathematical models describing the ball and plate dynamics are often linearized and the effects of complex motion are assumed to be negligible. These assumptions are rarely backed with evidence or explanations validating the simplified form of the dynamical equations of motion. This thesis focuses on developing a nonlinear model that more accurately defines the dynamics of the system, in order to quantify the error of linear and nonlinear models when compared to a Simscape physical …

Micro Scalable Graphene Oxide Productions Using Controlled Parameters In Bench Reactor, Carolina S. Andrade, Anna Paula Godoy, Marcos Antônio Gimenes Benega, Ricardo J. E. Andrade, Rafael Cardoso Andrade, Wellington Marcos Silva, Josué Marciano De Oliveira Cremonezzi, Waldemar Augusto De Almeida Macedo, Hélio Ribeiro, Jaime Taha-Tijerina

Manufacturing & Industrial Engineering Faculty Publications

The detailed study of graphene oxide (GO) synthesis by changing the graphite/oxidizing reagents mass ratios (mG/mROxi), provided GO nanosheets production with good yield, structural quality, and process savings. Three initial samples containing different amounts of graphite (3.0 g, 4.5 g, and 6.0 g) were produced using a bench reactor under strictly controlled conditions to guarantee the process reproducibility. The produced samples were analyzed by Raman spectroscopy, atomic force microscopy (AFM), x-ray diffraction (XDR), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetry (TGA) techniques. The results showed that the major GO product comprised of nanosheets containing between 1–5 layers, …

An Enhanced Framework To Compute Road User Costs Associated With Construction Zones, Jeremiah Adebiyi

Electronic Theses and Dissertations

The monetary quantification of inconveniences caused to the road users by ongoing construction activities is known as the Road Users Costs (RUCs). While the importance of RUCs is widely known, some highway agencies lack an appropriate methodology to compute RUCs. Thus, there is a need to develop a framework to compute RUCs that can be adopted quickly by highway agencies. This study reviewed existing literature and conducted a nationwide survey to identify and summarize the current practices of computing RUCs. It developed an enhanced framework and tool to compute RUCs that balances the effort required to calculate RUCs and the …

Quantification Of Compound And Cascading Hydroclimatic Extreme Events, Sourav Mukherjee

All Dissertations

Compound and cascading hydroclimatic extreme events have garnered much attention in recent studies. The combined effects of interconnected extremes can cause widespread damage, with a higher potential impact than individual extremes. Both anthropogenic warming and natural climate variability affect these extremes, which is why detecting past extreme events, understanding the underlying mechanisms, and assessing their future impacts can aid in mitigation efforts to reduce their overall impact. However, thus far, identifying such events is oversimplified and the propagation of their impact as cascades from the physical to human systems remains partly explored.

The overreaching goal of this thesis is to …

Effectiveness Of Softening Agents For Enhancing Properties Of Asphalt Mixes With High Rap Contents, Zahid Hossain, Ashraf Elsayed, Sumon Roy

Data

A high percentage of reclaimed asphalt pavement (RAP) in new asphalt concrete can lead to developing premature failure of asphalt pavements due to fatigue or low-temperature cracking. The use of softening agents in asphalt binders can resolve these problems. The aim of this study is to evaluate the effectiveness of softening agents for enhancing the properties of asphalt mixes with high RAP contents. Two waste products, namely, waste cooking oil (WCO), and engine bottom oil (EBO) along with a commercially produced rejuvenator were investigated in this study. The following three types of Performance Grade (PG) binders, each collected from two …

Development Of Cost-Effective High-Modulus Asphalt Concrete (Hmac) Mixtures Using Crumb Rubber And Local Construction Materials In Louisiana, Momen R. Mousa, Marwa Hassan, Ibrahim A.I.E Elnaml

Data

One of the emerging solutions to enhance the durability of asphalt pavements is the use of a French asphalt mix known as “High-Modulus Asphalt Concrete (HMAC).” This mix uses a hard asphalt binder, high binder content (about 6%), and low air voids content as compared to Superpave mixtures. The key objective of this study was to develop a cost-effective HMAC mixture using crumb rubber and local materials in Louisiana. To achieve this objective, four HMAC mixtures were prepared using two asphalt binders (PG 82-22 and PG 76-22 plus 10% crumb rubber) and two Reclaimed Asphalt Pavement (RAP) contents (20% and …

Evaluation Of Alternative Sources Of Supplementary Cementitious Materials (Scms) For Concrete Materials In Transportation Infrastructure, Gabriel A. Arce, Miladin Radovic, Zahid Hossain, Marwa Hassan, Sujata Subedi

Data

Fly ash is the most utilized supplementary cementitious material (SCM) in the US. Nonetheless, rapid decline in coal-fired power generation threatens its supply. The objective of this study was to evaluate alternative SCMs for concrete transportation infrastructure in Region 6. SCMs investigated included reclaimed fly ash (RFA), reclaimed ground bottom ash (GBA), metakaolin (MK), and conventional Class F fly ash (FA) as a reference. SCMs were characterized and the fresh and hardened properties of concrete incorporating different dosages (i.e., 10, 20, and 30% cement replacement by mass) of the individual SCMs (i.e., binary systems) and blended SCM systems of RFA-MK …

Feasibility Assessment Of Warm Mix Asphalt In Arkansas, Zahid Hossain, Ashraf Elsayed, Mohammad Najmush Sakib Oyan

Data

The future of Warm Mix Asphalt (WMA) technologies is promising in the U.S. However, the Arkansas Department of Transportation (ARDOT) does not have any specific guidelines to implement them in the field. This research aims to provide necessary baseline data for WMA as a proof of concept. In this study, three ARDOT approved Performance Grade (PG) binders namely PG 64-22, PG 70-22, and PG 76-22 were investigated. Each of these binders was obtained from two different sources. They were modified by varying doses of four selected additives: Sasobit®, Advera®, Evotherm®, and Rediset®. Additionally, four different types of aggregates (sandstone, limestone, …

Development Of Decision Trees For The Selection Of Pavement Maintenance And Rehabilitation Activities In South-Central United States, Momen Mousa, Marwa Hassan, Daniel E. Game

Data

Over time, new pavements deteriorate under the combined effects of traffic loading and the environment, no matter how well-designed or constructed. In general, maintenance and rehabilitation activities are employed to slow down or reset the rate of pavement deterioration. Cement-Stabilized Full Depth Reclamation (CSFDR) is a common rehabilitation treatment used by transportation agencies, specifically in Louisiana. Likewise, Ultra-Thin overlay (UTO) is a pavement maintenance treatment that has increased in popularity in recent years in Region 6. Yet, several gaps exist in the literature regarding the long-term field performance and cost-effectiveness of these two treatments especially in hot and humid climates. …

Network Analysis To Identify Critical Links For Relief Activities During Extreme Weather Events, Kate Kyung Hyun, Stephen P. Mattingly Ph.D, Mehrdad Arabi

Data

As one of the principal lifeline systems, transportation networks are crucial for evacuation and delivering essential resources and services during the response and recovery phases of extreme weather events and must remain intact to enhance regional resiliency. The conventional evaluation measures that estimate the vulnerability or criticality of road network based on travel time or link volumes do not capture the community impacts due to disruptions. This study seeks to develop a framework to evaluate road network infrastructure criticality during extreme weather events by introducing measures that evaluate the vulnerability of roads users, rather than the physical aspects of link …

Network Analysis To Identify Critical Links For Relief Activities During Extreme Weather Events, Kate Kyung Hyun, Stephen P. Mattingly Ph.D, Mehrdad Arabi

Publications

As one of the principal lifeline systems, transportation networks are crucial for evacuation and delivering essential resources and services during the response and recovery phases of extreme weather events and must remain intact to enhance regional resiliency. The conventional evaluation measures that estimate the vulnerability or criticality of road network based on travel time or link volumes do not capture the community impacts due to disruptions. This study seeks to develop a framework to evaluate road network infrastructure criticality during extreme weather events by introducing measures that evaluate the vulnerability of roads users, rather than the physical aspects of link …

Development Of Decision Trees For The Selection Of Pavement Maintenance And Rehabilitation Activities In South-Central United States, Momen Mousa, Marwa Hassan, Daniel E. Game

Publications

Over time, new pavements deteriorate under the combined effects of traffic loading and the environment, no matter how well-designed or constructed. In general, maintenance and rehabilitation activities are employed to slow down or reset the rate of pavement deterioration. Cement-Stabilized Full Depth Reclamation (CSFDR) is a common rehabilitation treatment used by transportation agencies, specifically in Louisiana. Likewise, Ultra-Thin overlay (UTO) is a pavement maintenance treatment that has increased in popularity in recent years in Region 6. Yet, several gaps exist in the literature regarding the long-term field performance and cost-effectiveness of these two treatments especially in hot and humid climates. …

Study On Hybrid Model Combining Super Learner And Physics-Based Models For Shm In Bridges Using Low-Cost Bwim, Suyun Ham Ph.D, Shih-Ho Chao, Kyeong Rok Ryu, Yin Chao Yu, Dafnik Saril Kumar David

Publications

The main objective of this project is to study and develop hybrid models of BWIM physics-based models incorporates with SHM inspection used by artificial intelligence (AI) techniques to predict structural damage. This study presents a comprehensive assessment of FE simulations leveraging contact method verified by vehicle-bridge interaction(VBI) theory and uses machine learning (ML) techniques to identify and predict structural damages from the structural response automatically. Bridges are a fundamental part of infrastructure management. The main challenge that we face is the aging of these transportation infrastructures without a tool to perform accurate structural assessments in a real-time manner. Unfortunately, this …

Study On Hybrid Model Combining Super Learner And Physics-Based Models For Shm In Bridges Using Low-Cost Bwim, Suyun Ham Ph.D, Shih-Ho Chao, Kyeong Rok Ryu, Yin Chao Yu, Dafnik Saril Kumar David

Data

The main objective of this project is to study and develop hybrid models of BWIM physics-based models incorporates with SHM inspection used by artificial intelligence (AI) techniques to predict structural damage. This study presents a comprehensive assessment of FE simulations leveraging contact method verified by vehicle-bridge interaction(VBI) theory and uses machine learning (ML) techniques to identify and predict structural damages from the structural response automatically. Bridges are a fundamental part of infrastructure management. The main challenge that we face is the aging of these transportation infrastructures without a tool to perform accurate structural assessments in a real-time manner. Unfortunately, this …

Evaluation Of Sustainable And Environmentally Friendly Stabilization Of Cohesionless Sandy Soil For Transportation Infrastructure, Miladin Radovic, Anand Puppala, Surya Sarat Chandra Congress, Jungyeon Jang, Oscar Huang

Data

Ordinary Portland cement (OPC) is generally used to stabilize cohesionless sandy soils that are often found in coastal areas. Due to its high carbon footprint, many studies are being conducted to identify a suitable green alternative for stabilizing cohesionless soils. Previous studies have shown that partially replacing OPC with waste materials such as nano-silica and coal waste reduces the overall carbon footprint without significantly impacting the performance. Geopolymer (GP) received a lot of attention in the past few decades owing to its similar properties to that of OPC yet with a lower carbon footprint. This study investigated the feasibility of …

Resilient 3d-Printed Infrastructure With Engineered Cementitious Composites (Ecc), Maryam Hojati

Data

Conventional construction of reinforced concrete structures is slow, labor-intensive, and expensive. 3D printing holds great potential to assist engineers and architects in constructing fast and economical yet complex representational infrastructures. One of the most significant barriers to the broader adoption of concrete 3D printing in civil infrastructure is the difficulty of providing printed structural components with reinforcement to achieve sound structural performance under different loading conditions. Hence, it is essential to design concrete that can be utilized as a rebar-free material by considering strength and ductility. Recently, the development of Engineered Cementitious Composites (ECC) has neared the possibility to achieve …

An Automated System For Inspecting Rock Faces And Detecting Potential Rock Falls Using Machine Learning, John Stormont, Fernando Moreu, Amir Bagherieh, Roya Nasimi, Solomon Atcitty

Data

Rockfall is a hazard in mountainous areas threatening infrastructure and human lives. Rockfall hazards are often mitigated by manual inspections using pry bars. The inspector must access the rock face, hit the rock surface, detect, and remove the loose rocks. This method is very labor demanding, unsafe, and challenging. This research presents a method that automatize the inspection of rock blocks that are prone to rockfall events. A robot is developed to replace the manual hammer tap process and collect the sound data remotely; subsequently, the sound signal is used to identify different types of the discontinuity in rocks in …

Resource Guide For State Dot’S Maintenance Equipment Fleet Management Decisions, Yongwei Shan, Samir Ahmed, Lei Qiao

Data

This research created a guide for state Departments of Transportation fleet management on utilizing equipment fleet management system data to make informed fleet management decisions. The research team took the historical equipment fleet data from the Oklahoma Department of Transportation and developed workflows, algorithms, and examples to demonstrate the use of historical equipment data for equipment decisions. Specifically, the research team demonstrated 1) the use of life cycle analysis and dynamic programming models for equipment replacement decisions; 2) developed algorithms to calculate equipment rental rates that can be used by the Department to forecast and allocate equipment operational budget among …

Preventing Struck-By Hazards: Defying Risk-Habituation Via Virtual Accident Simulation, Changbum Ahn

Data

Repeated exposure to struck-by hazards in road work zones generates workers’ habituation to risks related to those hazards, a key contributor to accidents in road work zones. Thus, analyzing the development of risk habituation and providing proper intervention are crucial to preventing accidents in road work zones. In this context, this study employs a virtual reality (VR) environment as a behavioral intervention tool to investigate its effect on mitigating a decline in workers’ vigilance with habituation to hazards in workplaces. A virtual environment that simulates a road maintenance task was developed and used to repeatedly expose subjects to struck-by hazards …

Bridge Cracks Monitoring: Detection, Measurement, And Comparison Using Augmented Reality, Fernando Moreu, Kaveh Malek

Data

Crack occurrence and propagation are among critical factors that affect the performance and lifespan of civil infrastructures such as bridges. Consequently, numerous crack detection and measurement methods have been proposed and developed in the recent decades in the areas of Structural Health Monitoring and non-destructive testing. Many novel technologies have emerged with the potential to overcome the limitations of the presented techniques of crack detection and characterization. Crack detection and characterization method used in this research lies in supplementing human visual inspection capabilities in a systematic manner through an appropriate level of automation. The Augmented Reality (AR) tool developed in …