Engineering Commons^™

Investigation And Modification Of Single-Post Aluminum Sign Supports For Mash Crashworthiness, Rodrigo Quintero

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Traffic signs are used to display information to drivers and are one of the most commonly encountered roadside structures. Although they are a vital traffic control device, signs can pose a significant safety risk to errant drivers due to their extensive placement and proximity to the roadway. Therefore, traffic signs and their supports must be designed with crashworthiness in mind to reduce the likelihood of injury in the event of a vehicle impact. Prior to 2009, these systems were evaluated using the crash testing criteria found in the National Cooperative Highway Research Program (NCHRP) Report No. 350 [1]. Currently, they …

Multiscale Modeling And Gaussian Process Regression For Applications In Composite Materials, Joshua Arp

All Dissertations

An ongoing challenge in advanced materials design is the development of accurate multiscale models that consider uncertainty while establishing a link between knowledge or information about constituent materials to overall composite properties. Successful models can accurately predict composite properties, reducing the high financial and labor costs associated with experimental determination and accelerating material innovation. Whereas early pioneers in micromechanics developed simplistic theoretical models to map these relationships, modern advances in computer technology have enabled detailed simulators capable of accurately predicting complex and multiscale phenomena.

This work advances domain knowledge via two means: firstly, through the development of high-fidelity, physics-based finite …

Trust-Based Runtime Verification Of Autonomous Robotic Systems, Maziar Fooladi Mahani

All Dissertations

 Trust plays a crucial role in enabling effective collaboration and decision-making within human-multi-robot teams. In this context, runtime verification techniques and trust inference models have emerged as valuable tools for assessing and quantifying the trustworthiness of individual robots. This dissertation presents a study on trust-based runtime verification and introduces a Bayesian trust inference model for human-multi-robot teams. Firstly, we discuss the concept of runtime verification, which involves monitoring and analyzing the behavior of robots during their operation. We highlight the importance of trust as a key factor in determining the reliability and credibility of robot actions. By integrating trust metrics …

Understanding The Hydromechanical Effects Of Extreme Events To Improve The Performance Of Infrastructure Foundations, Siddharth Marathe

All Dissertations

Extreme hydroclimatic events like heavy rainfall, flooding, and prolonged drought can potentially cause the failure of infrastructure foundations, leading to socio-economic losses. The objective of this dissertation is to understand the deformation and bearing capacity behavior of drilled shafts subjected to extreme hydroclimatic events, including heavy rainfall, prolonged drought, and earthquake. The Finite Element Method (FEM) results show that during rainfall, the drilled shaft settled caused by a decrease in the porewater pressure in the sand leading to a decrease in the axial bearing capacity. The axial force variation from an experimental investigation showed good agreement with the FEM. The …

Improved Vehicle-Bridge Interaction Modeling And Automation Of Bridge System Identification Techniques, Omar Abuodeh

All Dissertations

The Federal Highway Administration (FHWA) recognizes the necessity for cost-effective and practical system identification (SI) techniques within structural health monitoring (SHM) frameworks for asset management applications. Indirect health monitoring (IHM), a promising SHM approach, utilizes accelerometer-equipped vehicles to measure bridge modal properties (e.g., natural frequencies, damping ratios, mode shapes) through bridge vibration data to assess the bridge's condition. However, engineers and researchers often encounter noise from road roughness, environmental factors, and vehicular components in collected vehicle signals. This noise contaminates the vehicle signal with spurious modes corresponding to stochastic frequencies, impacting damage monitoring assessments. Thus, an efficient and reliable SI …

Examining The Influence Of The Classroom Environment On Motivation, Belonging, And Academic Confidence In Engineering Education: A Relational Developmental Systems Approach, Robert O'Hara

All Dissertations

This dissertation explores the impact of the classroom environment on undergraduate engineering students by integrating three manuscripts using the process-person-context-time (PPCT) model within Bioecological Systems Theory. Each manuscript focused on students’ sense of belonging, motivation, and academic confidence. The study confirms prior research suggesting a link between students' perceptions of the environment and their sense of belonging, motivation, and academic confidence. The findings highlight the complex nature of student and classroom environment relationships throughout their college experience. Moreover, the results are demonstrated across different engineering majors. Overall, this dissertation highlights the significance of understanding the complex interactions between students and …

Investigation Of Fatigue Response With Analytical And Machine Learning Models And Hygroscopic Analysis Of Asymmetric Bistable Cfrp Composites, Shoab Ahmed Chowdhury

All Dissertations

Asymmetric bistable carbon fibre reinforced plastic (CFRP) composites enable a broad range of applications as they can sustain multiple stable configurations and have small snap-through load requirements. These unique features, coupled with their light strength-to-weight and stiffness-to-weight ratios, have made them preferred options for multifunctional systems. This study investigates the fatigue and hygroscopic response of 2-ply, [0/90] bistable CFRP laminates and proposes predictive modeling approaches for improved performance.

While previous studies widely researched and documented the fatigue of general composites in axial loading, fatigue analysis of asymmetric bistable composites in the out-of-plane snap-through direction is inadequate. This study performs fatigue …

Modeling And Solution Methodologies For Mixed-Model Sequencing In Automobile Industry, Ibrahim Ozan Yilmazlar

All Dissertations

The global competitive environment leads companies to consider how to produce high-quality products at a lower cost. Mixed-model assembly lines are often designed such that average station work satisfies the time allocated to each station, but some models with work-intensive options require more than the allocated time. Sequencing varying models in a mixed-model assembly line, mixed-model sequencing (MMS), is a short-term decision problem that has the objective of preventing line stoppage resulting from a station work overload. Accordingly, a good allocation of models is necessary to avoid work overload. The car sequencing problem (CSP) is a specific version of the …

Investigating The Potential Of A Cell-Based Gene Editing Therapy For Inherited Metabolic Liver Disease, Ilayda Ates

All Dissertations

Inherited metabolic diseases (IMDs) affecting the liver are relatively rare but collectively have a prevalence of 1 in 800 live births. These diseases result from autosomal recessive single-gene mutations, leading to organ dysfunction and potentially fatal consequences if left untreated. One potential therapeutic strategy for IMDs of the liver involves using CRISPR-Cas9-induced loss of function mutations. However, translating this approach into the clinic is limited by the need for safe and effective CRISPR delivery methods. Adeno-associated viral vectors (AAVs), commonly used for CRISPR delivery, are associated with significant safety and efficacy concerns, including risks for immunogenicity, off-target mutagenesis, and genotoxicity …

Extensional Flows Of Polymer Solutions In Planar Microchannels, Mahmud Kamal Raihan

All Dissertations

Non-Newtonian fluids such as polymer solutions often flow under microscale extensional conditions in many natural and engineering flow fields such as in microfluidic chips, porous rocks, biological membranes and filters, printheads in additive manufacturing, etc. The changing cross sectional areas of the internal flow passages therein exert additional extension on the flow along with the shearing. Numerous studies have been dedicated to understanding the extensional flows of polymer solutions over the years. However, most of these studies only focused on flexible polymers exhibiting elasticity in their macroscopic rheology, whereas rigid polymers that portray shear-thinning but often elude elasticity in the …

Essays On Integer Programming Approaches To Analyze Equilibrium Solutions In Games, Lucky Cho

All Dissertations

In this dissertation, we present three applications of integer programming to analyze non-cooperative games. In a non-cooperative game, players of the game act selfishly and choose the best response given every other player's decision. The game reaches a Nash equilibrium when no player can benefit by changing its decisions. Our goal is to create an integer program that can identify these Nash equilibriums by modeling the best response of the game's players in the constraints. We prove a one-to-one correspondence between the game's Nash equilibrium and the feasible solution of a corresponding integer program. The one-to-one correspondence allows us to …

In Vitro And In Vivo Diabetic Models For Assessment Of Tissue Engineered Vascular Grafts, Juan Carlos Carrillo Garcia

All Dissertations

Diabetes has become one of the leading causes of lower-limb loss worldwide. Every 30 seconds, a person loses a limb due to diabetic-related vascular complications. About one-third of patients needing lower-limb bypass surgery have debilitated autologous vessels unsuitable for use, and no other good long-term options are available. These detrimental effects on the vasculature are caused mainly by the hyperglycemic and hyperlipidemic conditions derived from diabetes. Under these conditions, an increase in advanced glycation end products (AGEs) and reactive oxygen species leads to irreversible crosslinks of extracellular matrix proteins, accelerating vascular pathology through vascular stiffening, endothelial dysfunction, inflammation, atherosclerosis, fibrosis, …

Accurate Orientation Control Of Tendon Driven Continuum Robots That Exhibit Elasticity, Manu Srivastava

All Dissertations

This dissertation makes new contributions to the modeling and implementation of Tendon Driven Continuum Robots (TDCRs). Specifically, motivated by 3D printing of concrete using a continuum hose robot in construction applications, we focus on TDCRs featuring compliance in the robot backbone and actuating tendons, e.g. surgical robots/endoscopes/catheters with tendon actuation. We expand previous mechanics-based models to show how and why such compliance significantly restricts performance when traditional kinematics-based planning and control techniques are applied.

The main contribution of this work is a new Elasticity Compensation(EC) model that explains why the ad hoc approach of preloading/pretensioning the tendons compensates for compliance …

Fabrication And Measurement Of Lt-Gaas Photoconductive Antennas And Arrays, Zachary Paul Uttley

Graduate Theses and Dissertations

This thesis presents the fabrication and measurement of LT-GaAs based terahertz (THz) photo conductive antennas (PCAs) and arrays. The LT-GaAs THz PCAs are fabricated to serve as reference devices to new 2D material black phosphorous (BP) based THz PCAs. The LT-GaAs and BP devices have identical metallic electrodes, allowing for a comparison of emitted THz intensity and bandwidth. All PCAs have been measured using an open bench pulsed time-domain spectroscopy (TDS) system with a usable bandwidth from 0.1-4 THz, pumped with a 780nm Ti:Sapphire femtosecond laser. The results have shown LT-GaAs devices outperforming BP devices in signal amplitude and bandwidth …

Injectable Immunomodulatory Strategies To Enhance Muscle Recovery Following Injury, Tai Huu Huynh

Graduate Theses and Dissertations

Although skeletal muscle displays an astonishing regenerative capacity, injuries or diseases that resulted in bedridden or chronic muscle wasting can overwhelm this intrinsic feature of skeletal muscle and lead to functional deficit (range of motion and/or strength) and overall reduction in quality of life. Microenvironmental cues within injured skeletal muscle dictate regenerative and repair process which are tightly coordinated interplay among resident cells, cells recruitment and immune response following an assault in the muscle extracellular matrix (ECM). The successful regeneration of functional tissues requires both appropriate modulation of the inflammatory response, and activation of a variety of cell populations. Biomaterials …

Non-Energy Circular Economy Potential Of Rice Husks: A Techno-Eco-Environmental Assessment, Winfred Oppong Yeboah

Graduate Theses and Dissertations

The non-energy circular bioeconomy potential of rice husks was examined via sustainability assessments, namely life cycle assessment (LCA), life cycle impact cost assessment (LCICA), and techno-economic assessment (TEA). The study was conducted with three objectives. The first objective was to review previous studies on the non-energy utilization potential of rice husks by the method of meta-analysis. This review followed a systematic approach where research papers were collected following a defined set of criteria. The study revealed 16 key utilization pathways, all of which showed promising results. However, a comprehensive sustainability assessment was lacking in all of the pathways. The second …

Approximate Entropy And Velocity Of Center Of Pressure To Determine Postural Stability: A Pilot Study, Natalie Tipton, Gordon Alderink, Samhita Rhodes

Open Access Publishing Support Funded Articles

The body’s postural control system is responsible for responding to perturbations of balance and keeping the body upright. During quiet standing, the center of pressure oscillates about the center of mass, counteracting imbalances. These oscillations can be analyzed to determine the degree of stability, which could be helpful in quantifying the effects of brain injuries. In this research, the center of pressure was recorded for stances with feet together and feet tandem, with eyes opened and eyes closed, in neurotypical participants. These signals were analyzed using indices of approximate entropy and velocity to determine how sensitive the measures were in …

Performance And Emissions Study Of N+3 And N+4 Engine Models With Several Fuel Types Using Npss, Abel Solomon

McKelvey School of Engineering Graduate Student Theses & Dissertations

The aviation industry is known to be one of the major contributors to greenhouse gases accounting for 4.9% of the global greenhouse emissions. With the ever-increasing threat of climate change to the overall survival of the planet, the exploration of new technologies and alternative energy sources that minimize greenhouse gas emissions are of paramount importance. In this regard, the development of propulsion systems well suited for the performance and emissions requirements of future commercial aircraft plays a crucial role. This thesis investigates N+3 and N+4 technology-level propulsion systems that are proposed by NASA as possible propulsion systems for advanced single-aisle …

Survey Of How Irregularities In The Electrical System Of The Human Heart Link To Different Heart Arrhythmias, Jazmine Boloor

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis explores the circuital pathway that a signal takes within the heart throughout a full heartbeat and provides a timing analysis. It then surveys the different pathways that could arise in the electrical system of the heart, and the associated heart diseases linked to the location of each pathway. Common heart arrhythmias such as atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia, atrial flutter, and atrial fibrillation are surveyed, and their pathways are analyzed. Electrocardiograms are presented to aid in understanding of the timing analysis associated with irregularity in heart function. Finally, this thesis explores an avenue of the heartbeat …

Facial Expression Recognition Using Convolutional Neural Networks (Cnns) And Generative Adversarial Networks (Gans) For Data Augmentation And Image Generation, Shekhar Singh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Facial expressions play a crucial role in human communication, serving as a powerful means to convey emotions. However, classifying facial expressions using artificial intelligence (AI) can be challenging, especially with small datasets and images. Facial Expression Recognition (FER) is an active area of research, with Convolutional Neural Networks (CNNs) being widely employed for classification. In this research, we propose a CNN-based approach for FER that utilizes both original and augmented datasets to enhance classification accuracy. Experimental results on the FER2013 dataset show test accuracies of 63.39% and 64.59% for the original and augmented datasets, respectively, in a seven-class classification task. …

Multiphysics Numerical Modeling For Pfas Transport Within Vadose And Saturated Zones, Pierrette Iradukunda

Boise State University Theses and Dissertations

The extent and severity of wildfires have increased around the world, necessitating a greater understanding of the consequences of wildfire and post-fire impacts on soil and groundwater. Wildfire suppression techniques like aqueous film-forming foams (AFFF) can also contaminate the soil with per- and polyfluoroalkyl substances (PFAS), which can contribute to human and environmental health concerns. PFAS are dangerous man-made chemical compounds that are persistent, mobile, poisonous, and a major cause of soil and groundwater contamination. In addition to contamination by aqueous film-forming foams, PFAS has accumulated in the environment as a result of being utilized in numerous other goods over …

Effect Of Age On The Mechanical Behavior And Molecular Structure Of Human Meniscus: An Experimental And Computational Analysis, Derek Q. Nesbitt

Boise State University Theses and Dissertations

The knee meniscus is a soft fibrous tissue with a high incidence of injury in older populations. Surgical treatments do not fully restore the functionality of the meniscus, and the meniscus lacks native healing capacity, leading to a 40% increase in the probability of developing osteoarthritis once torn. Meniscus injury prevention is thus paramount to reducing the onset of osteoarthritis. Despite the importance of the meniscus in joint health, its mechanical properties, and how these change with age, are poorly understood. In order to quantify these properties, and how they change with age, we performed uniaxial tensile tests on two …

Maximizing The Performance Of Geocell Reinforced Pavement Bases With High-Fines Content Soils Through Micp Treatments, Ajay Kumar Reddy Pisati

Boise State University Theses and Dissertations

Crushed stone and gravel have long been favored for their stability and interlocking properties in Geocell reinforced base course layers of flexible pavement structures. However, their drawbacks, such as depleting reserves, escalating permit costs, environmental compliance, and extensive quarrying impacts, have led researchers to seek alternative options like recycled and on-site materials. Within this framework, utilizing native soil emerges as a promising solution to tackle these challenges. Nevertheless, the grading specifications impose limitations on the fines content allowed in base courses, as determined by the No. 200 sieve. However, the grading specifications pose restrictions on the permissible fines content in …

Enhanced Hardware Trojan Detection In Chips By Reducing Linearity Between Features, Alfred M. S. Moussa

Boise State University Theses and Dissertations

Globally, there has been an increase in demand for System on Chip (SoC) applications, active medical implants, and Internet of Things (IoT) devices. However, due to challenges in the global supply chain, the design, fabrication, and testing of Integrated Circuits are often outsourced to untrusted third-party entities around the world rather than a single trusted entity. This situation presents an opportunity for adversaries to compromise the device’s integrity, performance, and functionality by inserting malicious modifications known as Hardware Trojans (HTs) into the original design. HTs can also create a backdoor in the system for malicious alterations.

The problem of hardware …

An Experimental And Numerical Investigation Of Bimodal Particle Distributions For Enhanced Thermal Conductivity In Concentrating Solar Power Applications, Dallin Daniel Stout

Boise State University Theses and Dissertations

Solid particles have recently attracted substantial interest as a thermal transport medium in high-temperature energy storage and thermal energy conversion systems due to their ability to operate at high temperatures (up to 1000 °C). This is especially useful in the concentrating solar power (CSP) industry where solid particles are utilized as heat transfer media. Thermal conductivity of particles in CSP is critically important to the overall heat transfer that occurs within a heat exchanger. A cheap and effective avenue to increase the thermal conductivity of a particle distribution is by reducing its porosity by employing 2 differently sized particles. The …

Development Of Predictive Rockfall Runout Maps Based On Calibrated Rockfall Models, Olivia Tabor

Boise State University Theses and Dissertations

Cliffs formed in columnar jointed basalt have the proper geometry and discontinuities to initiate rockfall events. There are a number of locations in Boise, Idaho that may experience rockfall events from columnar jointed basalt cliffs. Publicly available LiDAR data coupled with site reconnaissance activities were used to develop calibrated two-dimensional rockfall models at a study site in southeast Boise. Photogrammetry was used to determine the volume of seven calibration boulders. The study site, located on Whitney Terrace, consists of a columnar jointed basalt cliff followed by a slope with a subdivision at the toe of the slope.

The two common …

Carbon/Carbon Composites For Next Generation Microvascular Solar Thermal Receivers, Matt Zuzelski

Boise State University Theses and Dissertations

Concentrating solar power (CSP) is a method of renewable solar power generation where the sun’s radiant energy is collected by a receiver and converted into thermal energy. This thermal energy is then passed into a heat transfer fluid and either sent to thermal storage, or a steam power plant. One path to better CSP systems is improving the operational envelope of the receiver and heat transfer fluid (HTF) system by utilizing more resilient absorbing materials, different path architectures, and HTFs with higher allowable temperatures.

A new carbon/carbon composite is being developed with the potential to function as the absorbing material …

Developing Firmware For Space Weather Probes 2 Using Hdl Coder, Nicholas L. Wallace

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

GPS and wireless communications are affected by interference from the ionosphere. Space weather affects plasma in the ionosphere, causing communication disruptions and reliability issues. To better understand how space weather affects the ionosphere, instruments are flown in space to collect data about the electrical characteristics of plasma in the ionosphere. Space systems require a lot of time and effort to develop and test. This thesis explores how a high level tool can be used to simplify the process and some obstacles that still exist with developing some space systems. To do this, the firmware architecture of a new version of …

A Cohesive Simulation And Testing Platform For Civil Autonomous Aerial Sensing And Operations, Stockton G. Slack

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Drones (also known as sUAS or small Uncrewed Aerial Systems) are often flown with cameras to take images of an area of land. These images can then be used to create a map by stitching these images together. This map can then be analyzed using scientific principles to learn things about the land and make decisions or take action based on the information.

The scientific application of drones is very advantageous, but flying a drone is inherently dangerous, impacting the safety of the airspace (particularly in the event of a crash), and drones are more dangerous the bigger they are. …

A Scalable, Cost-Oriented Approach For Computing Charge Plans For Electric Bus Fleets, Daniel T. Mortensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent attention for reduced carbon emissions has pushed transit authorities to adopt battery electric buses (BEBs). One challenge experienced by BEB users is extended charge times, which create logistical challenges and may force BEBs to charge when energy is more expensive. Furthermore, BEB charging leads to high power demands, which can significantly increase monthly power costs and may push electrical infrastructure beyond its present capacity, requiring expensive upgrades. This work presents a novel method for minimizing the monthly cost of BEB charging while meeting bus route constraints. This method extends previous work by incorporating a more novel cost model, effects …