Engineering Commons^™

Evaluation Of Accumulated Strain From Both Cyclic Triaxial And Static Creep Tests On Unbound Pavement Materials, Amir Mohammad Sajjadi

Theses and Dissertations

In this research, the behavior of Limerock (LR) aggregates blended with different reclaimed asphalt pavement (RAP) materials were investigated as an unbound base layer. Various combinations of LR and RAP, including 100%LR, 25%RAP75%LR, 50%RAP50%LR, and 100%RAP, were evaluated. Three main experiments performed on the samples were: static creep, static triaxial test, and cyclic triaxial test. The cyclic triaxial test was performed to measure the resilient modulus (MR) of materials. The results of the static triaxial test for 100% RAP showed that the deviator stress at failure steadily increased by increasing the confining pressure, while the 100% LR showed a maximum …

Optimal Onboard Renewable Energy Charging Method To Improve Micro-Autonomous Underwater Vehicle Deployment Life, Brooklynn Dawn Byford

Theses and Dissertations

This study is an investigation of various methods for recharging a micro autonomous underwater vehicle (μAUV) onboard using renewable energy sources while deployed at sea. The goal of this project is to determine the optimal onboard renewable energy design method to be used to prolong the deployment life of a μAUV. This project specifically targeted vehicles specifications and designs similar to the Riptide Autonomous Solutions’ μAUV[1], which was used for this study. Concluding results are based on the following factors: power generation versus time, structural integrity, and design complexity. The three design method categories investigated are as follows: solar energy, …

Finite Element Method For Assessment Of Air Cushion Skirt Performance, Thomas Arthur Lipscomb

Theses and Dissertations

The objective of this thesis is to create a method of simulating the performance of new materials for use in air cushion vehicle skirts. These systems currently exhibit unacceptable design lifetimes to be considered for widespread adoption, except in specific applications such a military or rapid transport, where high cost is not an obstacle. This project also focuses on using a new high strain to failure resin system that has recently been developed, in combination with high performance reinforcing fibers, to increase the lifespan of the skirt systems. Using industry-standard finite element modelling (FEM) software, a 3d model of the …

Extreme Response Analysis Of A Site-Specific Offshore Wind Turbine And Offshore Wind Farm Layout Optimization, Xiaosen Xu

Theses and Dissertations

Offshore floating wind turbines have been developed in deep water where bottom-fixed offshore wind turbines are cost-prohibitive. Gulf of Maine has one of the greatest potential wind energy on the east coast. A detailed analysis of metocean data is essential for the dynamic simulation of the floating offshore wind turbine and the offshore wind farm layout optimization. Wave scatter diagram represents the joint probability of significant wave height and peak periods. In the wind energy industry, turbulence intensity is defined as the standard deviation of the horizontal wind speed divided by the average wind speed over certain time period. Uniform …

Cloud Computing Service Interoperability And Architectural Concepts, Anmar Salih

Theses and Dissertations

Today’s market with a vast number of Cloud-computing providers creates a challenge for practical cooperation between the various provider cloud service platforms. Not only does Cloud interoperability provide this needed cooperation, but it also avoids vendor lock-in and, additionally, saves time and cost. Although there is no established definition for Cloud interoperability, most researchers agree on the purposes of Cloud interoperability. Research and literature have attempted to explain interoperability as transferring data, moving workloads, and migrating virtual machines between Cloud platforms. Transferring data between Clouds refers to objects migrating between provider-specific domains. In comparison, data migration is the most commonly …

Modern Standard Arabic Speech Recognition: Using Formants Measurements To Extract Vowels From Arabic Words’ Consonant-Vowel-Consonant-Vowel Structure, Mohamed Ali Alshaari

Theses and Dissertations

Arabic texts suffer from missing diacritics (short vowels) which become obstacles for new learners. Speech Recognition is the translation of words spoken to text through intelligent computer programs. As of today, it has been integrated into many computer systems. Arabic Speech Recognition has made progress over the years, but it is still not as good as English speech recognition due to the problem of short vowels not being recognized. This is mainly because the Arabic language is unlike the English language in the nature because it is a Semitic language. This is reflected in different characteristics such as grammar, morphology, …

Correlation Between Air Quality Index And Traffic Volume Using Internet Of Things (Iot), Omar Sayah Alruwaili

Theses and Dissertations

In highly populated world areas, such as metropolises, hazardous air pollution has been linked to the presence of damaging climate and health issues, which are becoming increasingly common. Indeed, a major problem facing urban areas today is air pollution. Gas emissions from vehicles can be seen as the most important source of this kind of pollution. Pollutant gases emitted as parts of car exhaust consist of chemicals such as carbon monoxide (CO), nitrogen dioxide (NO2), and sulphur dioxide (SO2), and ozone (O3), as well as particulate matter (PM). In some places in the world, non-governmental and foreign corporations have also …

Specifying Space Defense Operator Interfaces Through The Application Of Cognitive Systems Engineering And Prototyping, Justin E. Oryschak

Theses and Dissertations

The Department of Defense needs better tools to support its operators as they strive to defend its space assets. The growing sophistication of anti-satellite weapons increasingly challenges the nation’s orbital communications and surveillance infrastructure. Operators face difficulties gathering useful information and dealing with the complexity of potential enemy actions. This research applied cognitive systems engineering and ecological interface design (EID) methodologies to create a prototype space mission management tool that enhances operator situation awareness and decision-making ability. Applied cognitive task analysis interviews were used to document space operator decision-making in their domain. Model-based systems engineering was applied to integrate work …

Photoacoustic Co2 Detection In Biomass Cookstove Applications, Jacob Matthew Thomas

Theses and Dissertations

Billions of people use biomass burning cookstoves in their homes and suffer serious health repercussions. Additionally, global warming is exacerbated by cookstove emissions containing greenhouse gases and particulate matter. Improved cookstoves (ICSs) mitigate the problem, but accurate and affordable emission gas measurements, particularly of Carbon Dioxide (CO2) and Carbon Monoxide (CO), are required in order to confidently declare ICSs cleaner burning than traditional cookstoves. The aim of this research is to assess the suitability of photoacoustic (PA) CO2 detection technology for cookstove emissions monitoring. The designs of several longitudinally resonant, photoacoustic, LED, CO2 sensors of varying levels of functionality are …

Exploration Into The Use Of A Software Defined Radio As A Low-Cost Radar Front-End, Andrew Michael Monk

Theses and Dissertations

Inspection methods for satellites post-launch are currently expensive and/or dangerous. To address this, BYU, in conjunction with NASA, is designing a series of small satellites called CubeSATs. These small satellites are designed to be launched from a satellite and to visually inspect the launching body. The current satellite revision passively tumbles through space and is appropriately named the passive inspection cube satellite (PICS). The next revision actively maintains translation and rotation relative to the launching satellite and is named the translation, rotation inspection cube satellite (TRICS). One of the necessary sensors aboard this next revision is the means to detect …

Columbine And The Myth Of The Juvenile Superpredator, Christopher M. Mosqueda

Theses and Dissertations

Mass media has great influence over its audience. When a sensational story hits the news waves, the general public's attention is instantly riveted to the television screen. News stories that involve the deaths of innocent people often create a culture of fear, fuel false narratives, and scatter misinformation. In fact, this culture of fear, coupled with misleading information, created the myth of the juvenile superpredator, a phrase coined by DiIulio in the early 1990s. The stereotyped superpredator was a homicidal, uncontrollable youth hiding within areas where crime and violence are rare. In particular, this myth was propagated following the massacre …

Tidally Generated Internal Waves From Asymmetric Topographies, Kyle Jeffrey Hakes

Theses and Dissertations

Internal waves are generated in stratified fluids, like the ocean, where density increases with depth. Tides are one of the major generation mechanisms of internal waves. As the tides move water back and forth over underwater topography, internal waves can be generated. The shape of the topography plays a major part in the properties of the generated internal wave and the type of wave and energy is known for multiple symmetric topographies, such as Gaussian or sinusoidal. In order to further understand the effects topographic shape plays, the effect of asymmetry on internal waves is investigated. First, two experimental methods …

An Empirical Investigation Of The Dimensions Of Product Similarity Used In Design By Analogy Of Electromechanical Products, Arnold Nkoane Tsoka

Theses and Dissertations

Analogical reasoning is known to be a core cognitive mechanism behind creative human tasks including the creativity in engineering design. Research shows that during product ideation, designers use analogy to transfer information from prior designs stored in their memory (the source of the analogy) to the task in hand (target of analogy). However, similar to any search process, the source product must be first identified as a potential candidate for analogy before this information transfer can take place. Two products can be similar along multiple dimensions such as their form, function, etc. The dimensions of similarity between two products that …

Characterization Of Slip Activity In The Presence Of Slip Bands Using Surface-Based Microscopy Techniques, Ryan Aaron Sperry

Theses and Dissertations

Further understanding of mesoscale slip mechanics is crucial to future development of polycrystalline metals with improved performance. The research contained within this thesis aims to characterize localized mesoscale slip on slip bands further through two studies. First, a comprehensive comparison of slip system identification techniques was carried out to further validate each method as well as compare advantages and disadvantages of each. Second, slip bands in the presence of grain boundaries were studied to better characterize the dislocation content and behavior. In the first study, the use of SEM-DIC, AFM, ECCI, and HR-EBSD to characterize slip-system activity was assessed on …

Video-Based Gait Analysis For Health Monitoring, Xinyi Liu

Theses and Dissertations

Human gait is essential for long-term health monitoring as it reflects physical and neurological aspects of a person's health status. In this thesis, we proposed a non-invasive video-based gait analysis system to detect abnormal gait, and record gait and postural parameters on a day-to-day basis. The system does not require subjects to wear any sensors or attach markers on their body, therefore it is convenient to use in daily life. It takes videos captured from a single camera as input. OpenPose is used to localize skeleton and joints in each frame. Angles of body parts form multivariate time series. Then …

Dbknot: A Transparent And Seamless, Pluggable Tamper Evident Database, Islam Khalil

Theses and Dissertations

Database integrity is crucial to organizations that rely on databases of important data. They suffer from the vulnerability to internal fraud. Database tampering by internal malicious employees with high technical authorization to their infrastructure or even compromised by externals is one of the important attack vectors.

This thesis addresses such challenge in a class of problems where data is appended only and is immutable. Examples of operations where data does not change is a) financial institutions (banks, accounting systems, stock market, etc., b) registries and notary systems where important data is kept but is never subject to change, and c) …

Two-Photon 3-Dimensional Photoelectrochemical Etching Of Single Crystal Silicon Carbide, Peter Robert Nyholm

Theses and Dissertations

This thesis presents the first use of a novel direct-write, non-line-of-sight, two-photon photoelectrochemical etching technique for etching of single crystal silicon carbide substrates. The use of this technique has resulted in structuring of 3-dimensional structures in high quality single crystal silicon carbide wafers. The 3-dimensional structures demonstrated cannot be formed by any single or combination of traditional silicon carbide machining techniques. This thesis outlines the development of the optical, electrical, and diagnostic components required to achieve two-photon photoelectrochemical etching in silicon carbide. The diagnostic sub-assemblies --a single pixel confocal detector assembly and an in-situ optical microscope assembly-- and their design …

Molybdenum Deposition And Dissolution In Ethaline With The Use Of Fluoride Salts, Ethan Mitchel Gunnell

Theses and Dissertations

This work demonstrates the deposition of molybdenum in a deep eutectic solvent for the first time, and explores the processes needed for electrorefining of molybdenum. The electrochemical and transport behavior of chloride-coordinated molybdenum in ethaline was initially studied to determine if deposition was possible. Cyclic voltammetry was used to show that MoCl5 added to ethaline exhibits quasi-reversible behavior. Both the measured transfer coefficient and the precipitation of MoCl3 suggest that the reduction of MoCl5 in ethaline is a two-electron transfer reaction where the oxidation state of molybdenum in the product is Mo(III). No deposit was formed with the use of …

Local Eigenvalue Modification Procedure For Real-Time Model Updating Of Structures Experiencing High-Rate Dynamic Events, Claire Rae Drnek

Theses and Dissertations

Estimating the state of structures that experience high-rate dynamics requires real-time model updating capabilities. In this work, high-rate dynamic events are characterized by 1) large uncertainties in the external loads, 2) high levels of non-stationarities and heavy disturbances, and 3) unmodeled dynamics generated from changes in system configurations. To achieve real-time model updating, an algorithm must circumvent any pre-calculations and be able to update the structure’s state on the timescale of 2 ms or less. This can be accomplished in one of two ways: either by creating a simplified model of a complex structure or by simplifying the calculations needed …

A Comparative Study Of Cannabinoids & Cb1 Receptor Gi Signaling, Haley Kristen Andersen

Theses and Dissertations

The legalization of medical marijuana has highlighted cannabinoids as a potential, opioid-free therapeutic option for pain management; however, the rise in illicit synthetic cannabinoid-induced toxicity has demonstrated the need to outline cannabinoid molecular signaling. The cannabinoid-type 1 (CB1) receptor is an endogenous G protein-gated receptor (GPCR), well-expressed in the central nervous system (CNS) associated with modulating neuronal activity. Cannabinoid agonists bind to the CB1 receptor resulting in the inhibitory G protein (Gi) complex to dissociate into two subunits, Gβγi and Gαi. The Gαi subunit inhibits adenylyl cyclase, leading to a decrease in cyclic adenosine monophosphate (cAMP). The Gβγi subunit activates …

Ultrasonic Nondestructive Evaluation Using Non-Contact Air-Coupled Lamb Waves, Wenfeng Xiao

Theses and Dissertations

Ultrasonic Lamb waves have been proved as an effective nondestructive evaluation (NDE) method due to their ability to propagate a long distance with less energy loss as well as their sensitivity to various defects on the surface or inside the structure. However, there are still challenges towards using them as a rapid inspection method for complex structural geometries, various damage types, and harsh environments, such as efficiency in Lamb wave actuation and sensing, understanding of the complicated multi-modal Lamb wave propagation, and robust detection algorithms for damage quantification and evaluation. To address these challenges, this dissertation focuses on developing a …

Volume Frequency Response Method For Determining Mass Transfer Mechanisms Of O2 In Carbon Molecular Sieve 3k172, Olivia Smithson

Theses and Dissertations

Carbon molecular sieves (CMS) have grown more desirable over the years as an adsorbent for industrial separation processes as CMS technology has advanced. CMS is commonly used in nitrogen inerting (i.e, oxygen removal from air), carbon dioxide removal from methane and oxygen purification. However, knowledge of the dynamic behavior of these gases on CMS is needed to design and operate efficient and effective separation processes. For this reason, the mass transfer resistances within the micropore at both low and high frequencies were characterized using frequency response, COMSOL Multiphysics modeling, and MATLAB optimization , because frequency response methods have demonstrated the …

Methods For Dynamic Stabilization, Performance Improvement, And Load Power Sharing In Dc Power Distribution Systems, Hessamaldin Abdollahi

Theses and Dissertations

Modern DC power distribution systems (DC-PDS) offer high efficiency and flexibility which make them ideal for mission-critical applications such as on-board power systems of All-Electric ships, electric vehicles, More-Electric-Aircrafts, and DC Microgrids. Despite these attractive features, there are still challenges that need to be addressed. The two most important challenges are system stability and load power sharing. The stability and performance are of concern because DC-PDS are typically formed by the interconnection of several feedback-controlled power converters. The resulting interactions can lead to destabilizing dynamics. Likewise, in a DC-PDS there are several source converters that are operating in parallel to …

Computational Modeling Of Radiation Damage In A Multi-Phase Ceramic Waste Form Using Moose, Zeyu Chen

Theses and Dissertations

Ceramic waste forms have been proposed to replace the traditional glassy waste forms for long term stabilization of radionuclides. These waste forms are constantly exposed to self-irradiation emitted from the constituent radionuclides causing their material properties to change accordingly. It has been known that the radiation damage in waste forms is dominated by alpha particles emitted from transuranic (TRU) radionuclides. Since alpha particles usually have a range of 10~20 μm in such waste forms, some fraction of any non-transuranic containing phases (for a multiphase waste form) will be undamaged (or less damaged) if containing large enough grain sizes. Modeling and …

30 Ghz Path Loss Modeling And Performance Evaluation For Noncoherent M-Ary Frequency Shift Keying In The 30 Ghz Band, Mohanad Razak Mohsen

Theses and Dissertations

A candidate millimeter-wave (mmWave) frequency band and modulation scheme that could fit to many present and future applications has been presented in this work. As is being explored by industry, we also suggest the 30 GHz band as a candidate carrier frequency and non-coherent frequency shift keying (NC-FSK) as a potential modulation scheme for future communication applications. The primary applications are aimed at 5th generation (5G) cellular type systems. Propagation measurements were conducted for outdoor and indoor environments using directional horn antennas for both co-polarized and cross-polarized antenna configurations to model the path loss for our candidate band. The measurements …

Use Of Geospatial Technique To Estimate Traffic Volume On South Carolina Roads, Ryan Andrew Devine

Theses and Dissertations

Data from the Federal Highway Administration (FHWA) indicates that there is an increase in the number of vehicles on already congested roadways. For a department of transportation (DOT) to keep up with this increased demand, it is necessary for them to continuously collect and monitor traffic volume on the roads they maintain. One of the most important parameters that DOTs collect and use for traffic engineering and transportation planning studies is annual average daily traffic (AADT). The DOTs are also required to collect and report AADTs to the Federal Highway Administration annually as part of the Highway Performance Monitoring System …

Hydrogenation Of Dimethyl Oxalate To Ethylene Glycol Over Silica Supported Copper Catalysts, Xinbin Yu

Theses and Dissertations

Ethylene glycol is a bulk chemical and hydrogenation of dimethyl oxalate (DMO) on Cu/SiO2 catalysts is the final reaction step in a growing industrial syngas to ethylene glycol (StEG) process. Efforts to improve the performance of the catalysts are still ongoing and the detailed catalytic mechanism remains controversial.

In the present work, a series of 10 wt% Cu/SiO₂ is prepared.by urea hydrolysis method and indium species is introduced by incipient wetness impregnation. Reaction studies show that 0.25 wt%-0.5 wt% of indium species can dramatically enhance the performance of 10 wt% Cu/SiO₂ catalyst. Various characterizations reveal that indium species …

Evaluating The Stabilization Of Gypseous And Gypsiferous Sands Using Different Chemical Additives To Mitigate Gypsum Dissolution, Mohammed Kamil Faris

Theses and Dissertations

Gypsum, which is dihydrate calcium sulfate, (CaSO4.2H2O), is widely available in different sizes, from the size of a rock to the size of a few micrometers as a mineral, in different types of soils. It is primarily found mainly in arid and semi-arid areas around the world at different depths. Soils with gypsum and even gypsum rocks are very hard in their dry state. However, these soils and rock will experience remarkable dissolution upon wetting.

The dissolution phenomenon, which takes place in soils that contain gypsum, creates different geotechnical problems within the soil’s profile, along with foundation issues for structures …

Lamb Wave Nondestructive Evaluation And Imaging On Plate-Like Structures, Zhaoyun Ma

Theses and Dissertations

Structure components are designed with a certain service life and damage may occur, or they may come with manufacture defects. Such damage and defects may lead to structural failure if not detected in time. To ensure the structural safety and prevent catastrophic failure, effective inspection is critical for in-time maintenance. Nondestructive evaluation (NDE) and structural health monitoring (SHM) have been widely applied for damage inspection and evaluation in various industries due to their noninvasive nature. Lamb wave based NDE/SHM has become the most popular ultrasonic methods that has been proved effective in different engineering applications that can be used to …

Mathematical Modeling Of Lithium-Sulfur Batteries, Niloofar Kamyab

Theses and Dissertations

Energy storage market transformed by utilization of lithium-ion batteries, will demand high and affordable deliverable energy in the near future which it would be impossible for the current employed technologies to meet those needs Among new generation of lithium batteries, high theoretical energy density, good low-temperature performance, and abundance of inexpensive nontoxic raw material, make the lithium-sulfur batteries (LiS) a promising candidate to outperform the current lithium-ion batteries and transform the technology of the future. However, the problems and challenges that LiS batteries are currently facing with, which stem from the inherent complex mechanism of these cells, are hindering their …