Engineering Commons^™

Comparative Design Space For Bistable Composites: An Integrated Framework Of Optimization, Finite Element Analysis, And Experimental Testing, Jonathan Bolanos

All Theses

Bistable composites are a class of advanced materials that can actuate between two stable shapes, making them attractive for a wide range of engineering applications. However, designing these composites to achieve optimal performance remains a challenging task. To address the challenge, this research develops an integrated framework that combines a genetic algorithm optimization technique, finite element analysis in Abaqus, and experimental testing to explore the design comparative space for square bistable composites composed of DA 409 carbon fibers. This leads to the study of generating an optimization algorithm to account for the relationship between the chances of a successful maximum …

Laser Stabilization Through Optical Turbulence, Liam Vanderschaaf

All Theses

Laser jitter presents a significant issue in the fields of laser communication and sensing. There are two main categories of positional noise in regards to the instantaneous centroid of a laser propagating over long distances: jitter resulting from optical turbulence and jitter resulting from mechanical vibrations. Optical turbulence was generated using Clemson University’s Variable Turbulence Generator (VTG). The VTG is capable of creating a desired level of optical turbulence that is comparable to atmospheric conditions with fried parameters greater than 0.3 cm. A gaussian laser was transmitted through the VTG and a system of Fast Steering Mirrors and Position Sensing …

A Hidden Spider Web Of Roots: Utilizing Ground Penetrating Radar To Uncover Laterally Expansive Roots Of An Oak Tree, Megan Lapkoff

All Theses

Roots are critical to understanding tree health, subsurface biomass, and overall tree root stability. However, accessing tree roots is difficult and traditional methods used to quantify roots harm or kill the tree. Ground penetrating radar (GPR) provides a non-invasive way to characterize subsurface roots without harming the tree. GPR provides high-resolution data and the ability to collect data with high spatial coverage, making it an ideal tool for characterizing roots. GPR works by detecting contrasts in dielectric permittivity or electromagnetic (EM) velocity at interfaces between materials. Small scattering objects, like roots, generate predictable artifacts called diffraction hyperbolas. Diffraction hyperbolas will …

Development And Evaluation Of Machine Learning Models For Fugitive Methane Detection And Intensity Prediction, Jacquan Pollard

All Theses

The environmental impacts of global warming driven by fugitive methane (CH4) emissions have catalyzed significant research initiatives in developing novel technologies that enable proactive and rapid detection of CH4 emissions. This study evaluated the performance of data-driven machine learning (ML) models using support vector machines (SVM) to detect the presence of trace CH4 emissions and the corresponding intensity amongst various meteorological conditions. The author used simulation data comprising various meteorological parameters such as temperature, relative humidity, wind speed, water vapor, pressure, precipitation rate, and a parameter possessing trace concentrations of CH4 emissions. The novelty of the SVM models developed in …

Evaluating The Effect Of Palmitic Acid Concentration On Growth And Inhibition Of Syntrophomonas Sp., Clancy Kerr

All Theses

Various industries produce fats, oils, and greases (FOG). These hydrophobic compounds cause issues in municipal wastewater collection and treatment systems. Anaerobic co-digestion is an effective way to treat FOG and presents an opportunity to produce more significant quantities of biogas. However, many microorganisms are sensitive to the degradation products like long-chain fatty acids (LCFAs). Palmitic acid is the most prevalent LCFA in anaerobic co-digestion of FOG and wastewater. Sytrophomonas is a β-oxidizer able to break down palmitic acid. Palmitic acid is known to feed and inhibit Syntrophomonas growth and methanogenesis. The objectives of this investigation are: To determine if Syntrophomonas …

Use Of Smartphone Apps While Driving: Variations On Driving Performances, Perceived Risks And Behaviors, Juana Perez

Civil Engineering Theses - Archive

ABSTRACT: Distracted driving increases the crash frequencies on the road and subsequently leads to fatalities involved with crashes. As technology has evolved, drivers are continuously exposed to newer technology in their vehicles and applications in their phones, which has led to technology representing one of the main secondary tasks that distract drivers on the road. The impact of technology-involved distraction appears to be different by the type of distraction since a secondary task that can be exceedingly distracting to the driver causes more reckless and risky driving. Moreover, the impact of distracted driving may differ by roadway geometries since distracted …

Compliant Robot Manipulator For Transurethral Diagnosis, Samson A. Adejokun

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT: Minimally invasive procedures employ continuum manipulators, however, the internal human anatomy presents challenges relating to size, dexterity, and workspace for these manipulators. This research presents modeling, kinematic analysis, limited prototyping, and characterization of a micro-robotic manipulator to assess viscoelastic tissue properties of the bladder through transurethral palpation towards the diagnosis of bladder dysfunction, urinary incontinence, and early-stage bladder cancer. The proposed micro-robot consists of two subsystems; a unique 4mm outer diameter tendon-driven continuum segment from assembled “vertebrae” components with male and female snap-in features for joint assembly, an elastic tube encompassing each joint for controlled compliance and structural integrity …

Development Of Femtosecond Laser Electronic Excitation Tagging (Fleet) And Femtosecond Two-Photon Absorption Laser Induced Fluorescence (Fs-Talif) Diagnostics For Species Number Density And Velocity Measurements In Arc-Jet Flows, Daniel William Palmquist

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT: Arc-jet flows are the only ground-test facilities that can recreate hypersonic high-enthalpy flight conditions for long durations. Characterizing these complex flow regimes, generally under thermo-chemical non-equilibrium, is crucial to establishing a relationship between the ground-test environment and flight conditions. This work presents the development of two innovative and world’s first successful application of advanced non-intrusive laser-based diagnostic techniques for characterizing the 1.6 MW ONR-UTA Arc-Heated Wind Tunnel, Leste’s plasma flow. The arc-jet flow represents a unique challenge for the application of laser-based diagnostics due to the highly emitting background across a wide spectral range. Femtosecond Laser Electronic Excitation Tagging …

Formal Processes For Inspecting Bridge Deck Drains Using Lidar And Photogrammetry, Ahmad Kamal Bani Hani

Civil Engineering Dissertations - Archive

ABSTRACT: Poor-performing bridge deck drains result in water standing on the bridge deck. The standing water threatens the safety of bridge users and deteriorates bridge structural elements. Bridge deck drains are only inspected biennially, and they do not impact the bridge rating established from inspections. Furthermore, literature shows that visual inspection results are sometimes skewed due to human errors. In this regard, a part of this research was conducting a survey study to help identify the problems with deck drains to help transportation agencies minimize the consequences of poor drainage. Another part of this research was to create a convolutional …

Physiological Analyses Of Broadband Near-Infrared Spectroscopy And Electrophysiological Measurements In Vivo For Biomedical Applications, Haylea Renguul

Bioengineering Theses - Archive

My thesis concerns analysis of data from optical and electrophysiological measurement tools for calculate potential biomarkers in three biomedical applications: (1) the gastrointestinal immaturity of infants of different ages, (2) prefrontal connectivity in healthy older adults, and (3) hemodynamic-metabolic coherence during vascular occlusion. The first application relied on electrogastrogram (EGG) measurements taken on 81 newborns in a neonatal intensive care unit. Of the 81 babies, 77 were born prematurely. By separating these babies into different gestational age groups and analyzing their EGG data, I was able to find population differences in common EGG analysis parameters. In particular, we found that …

Fatigue Performance Modeling In Advanced Out-Of-Autoclave Composites For Aerospace Applications, Grayson Reid Curry

Mechanical and Aerospace Engineering Theses - Archive

Increased application of composite materials in the military and civil applications renewed the interest to development of high-fidelity methodologies for predicting their performance characteristics. Besides the traditional autoclave processed structural composites such as IM7/8552 and IM7/977-3 widely used on various platforms, novel materials such IM7/5320-1 suitable for Out-of-Autoclave (OoA) cure became of interest. Static and fatigue performance prediction of Open-Hole quasi-isotropic laminates made from IM7/5320-1 was performed in this work by using the Finite Element Analysis software BSAM. Progressive failure simulation including delaminations, matrix cracks and fiber failure was performed. Regularized eXtended Finite Element Methods (RXFEM) was used for mesh …

Dispersion Study Of Metal-Organic Frameworks And Synthesis Of Mof-High-Density Polyethylene Fibers, Sathvika Gondi

Material Science and Engineering Theses - Archive

Metal-Organic Frameworks (MOFs) are a highly versatile class of materials with a wide range of potential applications in gas storage, separation, catalysis, drug delivery, and sensing. The ability to tailor the properties and functionalities of MOFs by varying the organic linkers and inorganic nodes makes them highly attractive for a wide range of applications. The unique properties of MOFs also make them promising materials for fundamental studies in materials science and chemistry. The current investigation focuses on the dispersion study of MOFs and the synthesis of MOF-Polymer composites. The dispersions of MOFs in various organic solvents like ethanol, isopropanol, tetrahydrofuran, …

Application Of Photogrammetry For Monitoring Soil Surface Movement, Arjan Poudel

Civil Engineering Theses - Archive

Understanding slope behavior and forecasting failure requires accurate soil surface movement measurements. Research gaps and constraints remain despite the development of diverse methods. Recently, photogrammetry has become a promising method for detecting soil surface movement. This method involves setting coded targets and ground points on the soil surface, taking photographs before and after the movement, and using photogrammetric software to measure accurately. However, past studies have mostly used high-end cameras with excellent resolution and geotagging, which may not have been available in all contexts. Thus, this study compares the accuracy and precision of geotechnical soil surface measurement with a consumer-grade …

Testing The Effects Of Different Designs On The Physical Properties Of 3d-Printed Watch Bands, Ross Harper

Industrial Engineering Undergraduate Honors Theses

Technological innovation progresses at an ever-increasing rate, and this is especially true in the field of 3D-printing. 3D-printing has become popular in manufacturing settings and among amateur hobbyists alike, largely because 3D-printers can fabricate an enormous number of designs from an array of materials and allow for fine-tuning through several setting options. Individuals with proficient 3D-printing abilities can produce a nearly infinite number of components for diverse applications in manufacturing, recreation, ergonomics, and many more. Some individuals use their skills to create functional substitutes for name-brand items, including bands to fit and be worn with a smart watch. However, little …

Lead Distribution Modeling For Supply Chains With A Large Number Of Items, Wesley Tate

Industrial Engineering Undergraduate Honors Theses

Adding randomness into a simulation model allows for a better understanding of the variation that can occur in a real-life setting. This paper documents the methodology used to recommend a set of distribution models to cover administrative and production lead times for the simulation program involving hundreds of thousands of items. The problem of distribution fitting for large datasets is addressed, with histograms, Q-Q, and P-P plots being used to verify models in addition to goodness-of-fit test statistics. Variable level reduction using frequency and distribution matching approaches are outlined followed by the use of random forest modeling to identify key …

A Reconfigurable Architecture For Matrix Multiplication For Low Power Applications, Jeffrey Love

Electrical and Computer Engineering ETDs

This thesis presents a hardware architecture for performing matrix multiplication via a systolic array to reduce time complexity and power consumption. The proposed architecture, the Neural Network Accelerator (NNA), was designed in Verilog HDL to perform 8-bit multiplication to reduce the resources required to implement the NNA on low-power FPGAs. The NNA’s open architecture is designed to support radiation test for fault tolerant designs targeting space applications. Commercial hardware architecture information is not public knowledge, which led us to build our own matrix multiplication architecture so that we could later study its feasibility for space applications.

The NNA was compared …

Universal Short-Circuit And Open-Circuit Fault Detection For An Inverter, Buck Brown

All Theses

Short-circuit and open-circuit faults of an inverter’s power device often lead to catastrophic failure of the entire system if not detected and acted upon within a few microseconds, particularly for emerging wide bandgap (WGB) power semiconductors. While a significant amount of research has been done on the fast and accurate protection and detection of short-circuit faults, there has been less success corresponding to the research on open-circuit faults. Common downfalls include protection and detection that are too application-specific, take longer than a couple of microseconds, and are not cost-efficient. This study proposes a new open-circuit fault protection and detection system …

Low-Cost Microstereolithography 3d Printing With Microfluidic Microsampling Applications, Lauren Twombly

Chemistry & Biochemistry Undergraduate Honors Theses

The growing field of stereolithography 3D printing has welcomed a new age ofmicrofluidic device fabrication techniques. When compared to previous planar fabrication techniques such as soft-lithography, stereolithography 3D printing offers highly automated procedures, reduced fabrication times, and greater complexity of device features. To date, the greatest tradeoff for 3D printing in microfluidic device fabrication is poorer resolution when compared to soft-lithography which can produce feature sizes on the nanometer scale. The poorer resolution of 3D printing limits the feasible size of features. While highly sophisticated 3D printers are capable of achieving sub 10 μm resolution, these instruments are incredibly expensive …

Network Effects Of Emergency Department Clinician Strain And Patient Congestion, Aisha Nelson

All Theses

We develop a discrete-event simulation model to study how staffing strain affects patient outcomes across a network of Emergency Departments (EDs). The aim is to observe how clinician staffing and transfers throughout the system affect the system’s behavior. We will study the network of the seven EDs in the Prisma Health-Upstate system. Patient acuity and resource need are stratified using the five-level Emergency Severity Index (ESI). Patient flow data within and between EDs are collected from EPIC, staffing data from ShiftAdmin, and environmental COVID-19 prevalence data from the Department of Health and Environmental Control. Time periods include the Omicron wave …

Systematic Literature Review Of Roof Systems On Energy Efficiency Of A Building To Support An Ideal Study Framework, Ayushi Raj Dua

All Theses

A sustainable building envelope is a crucial element to build energy efficient structures that contribute towards sustainable communities. The demand for sustainable building envelopes has grown in response to a growing emphasis on sustainable living. The roofing system is an important component of a sustainable building envelope because it influences the building's energy consumption and indoor comfort levels. The current study focuses on roofing systems and associated solar reflectance and albedo values to document the impact on energy efficiency via cooling/heating energy usage, dollar savings and temperature (ambient and surface) reductions due to the roofing systems. Additionally, the study focuses …

Connecting The Dots For Contextual Information Retrieval, Pei-Chi Lo

Dissertations and Theses Collection (Open Access)

There are many information retrieval tasks that depend on knowledge graphs to return contextually relevant result of the query. We call them Knowledgeenriched Contextual Information Retrieval (KCIR) tasks and these tasks come in many different forms including query-based document retrieval, query answering and others. These KCIR tasks often require the input query to contextualized by additional facts from a knowledge graph, and using the context representation to perform document or knowledge graph retrieval and prediction. In this dissertation, we present a meta-framework that identifies Contextual Representation Learning (CRL) and Contextual Information Retrieval (CIR) to be the two key components in …

Iii-Nitride Triangular Microcantilevers For Multimodal Sensing Applications, Balaadithya Uppalapati

All Dissertations

Micro-electromechanical systems (MEMS)-based sensors have gained significant attention due to their ability to sense, measure, and process various physical, chemical, and biological parameters. The small size of MEMS sensors provides numerous advantages, including low power consumption, high sensitivity, and rapid response time, making them suitable for various applications in healthcare, automotive, aerospace, and consumer electronics.

In the past few years, AlGaN/GaN MEMS devices have been found to offer several advantages over silicon-based MEMS devices. One of the main advantages of AlGaN/GaN MEMS is their high sensitivity to surface stresses and forces due to their high piezoelectric coefficients. This sensitivity allows …

Mesoscale Modeling And Machine Learning Studies Of Grain Boundary Segregation In Metallic Alloys, Malek Alkayyali

All Dissertations

Nearly all structural and functional materials are polycrystalline alloys; they are composed of differently oriented crystalline grains that are joined at internal interfaces termed grain boundaries (GBs). It is well accepted that GB dynamics play a critical role in many phenomena during materials processing or under operating environments. Of particular interest are GB migration and grain growth processes, as they influence many crystal-size dependent properties, such as mechanical strength and electrical conductivity.

In metallic alloys, GBs offer a plethora of preferential atomic sites for alloying elements to occupy. Indeed, recent experimental studies employing in-situ microscopy revealed strong GB solute segregation …

Uibee: An Improved Deep Instance Segmentation And Classification Of Ui Elements In Wireframes, Cahi̇t Berkay Kazangi̇rler, Caner Özcan, Buse Yaren Teki̇n

Turkish Journal of Electrical Engineering and Computer Sciences

User Interface (UI) is a basic concept in which individuals interact with any computer program or technological device to create a graphical design. In the initial stages of app development, UI prototype is a must. An automatic analysis system for the basic execution of UI designs will considerably speed up the development of designs according to old-fashioned methods. In this approach, it is aimed at saving cost and time by automating the process. For the aforesaid objective, we present a new approach rather than the traditional methods. For this reason, a high amount of elements in wireframes are detected and …

Optimization Of Porosity In Cold Spray Produced Copper And Zinc Coatings, Cameron Hughes

Graduate Theses & Non-Theses

Since its invention in 1981, the cold spray (CS) additive manufacturing (AM) process has been studied and optimized to produce well-adhered, dense material coatings. CS can operate at a wide range of temperatures if the feed material remains in a solid state. Copper and zinc were studied to characterize and understand the effects of heating element voltage, travel speed, and standoff distance on deposit porosity, grain size, microhardness, and coating thickness. Samples were sprayed on 3.2 mm x 25 mm x 150 mm 6061 aluminum substrates. Sections were taken from the middle of the samples to represent steady-state conditions. Sample …

High-Pressure Slurry Ablation For Improving Separation Of Copper/Molybdenum And Flotation Of Gold Tailings, Mitchell Harvey

Graduate Theses & Non-Theses

Disa Technologies’ High-Pressure Slurry Ablation (HPSA) is a patented particle attrition technology for the comminution and selective liberation of minerals. Two slurry streams are pumped at high pressure through opposing nozzles and collisions between solid particles suspended in the slurry streams cause breakage of the feed material. HPSA was evaluated for improving the rougher flotation of molybdenite from Cu-Mo bulk concentrate and gold-bearing pyrite from gold tailings.

Copper/molybdenum samples were provided by Montana Resources in Butte, Montana. A two-factor factorial design of experiments was used to identify HPSA operating conditions which gave the highest increase in flotation performance. Variables were …

Predicting The Damage Behavior And Fracture Propagation In A 3d-Printed Synthetic Rock Material With The Distinct Element Method (Pfc3d) And Hybrid Finite-Discrete Element Method (Irazu3d), Frankie Johnston

Graduate Theses & Non-Theses

The ability to monitor and predict the evolution of rock damage and fracture is key for creating reliable and sustainable civil infrastructure. Rock crack propagation is a complex process that is dependent on material properties such as tensile strength, compressive strength, density, elastic modulus, Poisson's ratio, friction coefficient, cohesion, and specimen conditions such as preexisting microcracks, particle size distribution, and mineral distribution. In conjunction with the 56th US Rock Mechanics/Geomechanics Symposium, researchers primarily at Purdue University organized the Damage Mechanics Challenge to determine the current state and future direction of the rock modeling community’s ability to simulate rock crack formation. …

Improving Inference Speed Of Perception Systems In Autonomous Unmanned Ground Vehicles, Bradley Selee

All Theses

Autonomous vehicle (AV) development has become one of the largest research challenges in businesses and research institutions. While much research has been done, autonomous driving still requires extensive amounts of research due to its immense, multi-factorial difficulty. Autonomous vehicles rely on many complex systems to function, make accurate decisions, and, above all, provide maximum safety. One of the most crucial components of autonomous driving is the perception system.

The perception system allows the vehicle to identify its surroundings and make accurate, but safe, decisions through the use of computer vision techniques like object detection, image segmentation, and path planning. Due …

Adversarial Deep Learning And Security With A Hardware Perspective, Joseph Clements

All Dissertations

Adversarial deep learning is the field of study which analyzes deep learning in the presence of adversarial entities. This entails understanding the capabilities, objectives, and attack scenarios available to the adversary to develop defensive mechanisms and avenues of robustness available to the benign parties. Understanding this facet of deep learning helps us improve the safety of the deep learning systems against external threats from adversaries. However, of equal importance, this perspective also helps the industry understand and respond to critical failures in the technology. The expectation of future success has driven significant interest in developing this technology broadly. Adversarial deep …

The Impact Of A Carbon Tax On Emissions, Jessica Creech

Industrial Engineering Undergraduate Honors Theses

A carbon tax is an economic policy that aims to reduce various emissions to serve the protection of the environment. Versions of this policy have been implemented in multiple countries across the world to introduce a cost for contributing to environmental damage. Since climate change is prevalent in today’s world, finding an effective method to reduce emissions is essential. However, many countries hesitate to utilize a carbon tax for two reasons. First, they are unsure if the carbon tax is effective at reducing emissions. Second, there is a concern that the implementation of such a tax will be detrimental to …