Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Theses and Dissertations

Discipline
Institution
Keyword
Publication Year

Articles 2071 - 2100 of 11503

Full-Text Articles in Engineering

Tap Water Disinfection In The Electrochemical Precipitation Process By Using Novel Conductive Concrete, Md Shoriful Islam Aug 2022

Tap Water Disinfection In The Electrochemical Precipitation Process By Using Novel Conductive Concrete, Md Shoriful Islam

Theses and Dissertations

Electrochemical precipitation (EP) is tested to learn about its impact on disinfectants in tap water. The EP process involves applying electricity through electrodes submerged in water to precipitate dissolved metals like water hardness out without chemical additives. In the study, tap water was tested to learn about EP’s impact on disinfectants. Tap water contains not only hardness but also residual disinfectants. It is very essential for the safety of drinking water against the potential ingress of pathogens before the water reaches the end-users. USEPA mandates that the free chlorine level in drinking water should be 0.2mg/L to 4 mg/L. …


Advance In Contextualizing Focal Structure Sets In Complex Network Analysis, Mustafa Alassad Jul 2022

Advance In Contextualizing Focal Structure Sets In Complex Network Analysis, Mustafa Alassad

Theses and Dissertations

Focal Structures are key sets of individuals who may be responsible for online socially minded events, protests, or leading citizen engagement efforts on social media networks. Discovering focal structure sets who able to promote online social campaigns is important, but complex, as they are typically active locally, globally, and acting unlike central users and influencers, focal structure sets can influence large social media networks. Researchers applied a greedy algorithm to discover focal structure sets in social media networks. However, the outcomes were lacking on the users’ activities and interests that made the analysis incomplete. In this research, I present a …


Selecting And Optimizing Origami-Based Patterns For Deployable Space Systems, Diana Stefania Bolanos Jul 2022

Selecting And Optimizing Origami-Based Patterns For Deployable Space Systems, Diana Stefania Bolanos

Theses and Dissertations

This thesis addresses the design difficulties encountered when designing deployable origami-based arrays. Specific considerations regarding thickness accommodation, deployment, and parameter modifications are discussed. Patterns such as the Miura-ori, flasher, and hexagon are investigated, with emphasis placed on pattern modification from zero-thickness to finite-thickness. Applying origami principles to form engineering solutions is a complicated task. Competing requirements may create confusion around which pattern is most favorable for the space array application. Implementing origami into a finite-thickness, engineered system poses challenges that are not manifest in a zero-thickness model. As such, it is important to understand and address the limitations of the …


Ethanol-Induced Impacts On Nervous System Development And Dopamine Transporter Characterization In Schmidtea Mediterranea Planaria, Brennen Covely Jul 2022

Ethanol-Induced Impacts On Nervous System Development And Dopamine Transporter Characterization In Schmidtea Mediterranea Planaria, Brennen Covely

Theses and Dissertations

Fetal alcohol spectrum disorders (FASD) are diagnosed in 2-5% of newborns, but the biology underlying FASD is poorly understood and challenging to study with existing model organisms. A new model for FASD research is Schmidtea mediterranea (Smed) planaria. Smed have a remarkable ability to regenerate their central nervous system (CNS), and possess a well-studied, simple genome. Previous studies have shown that ethanol exposure delays this regeneration, yet this relationship is not fully understood. Here, we show that alcohol exposure affects Smed in a dose-dependent manner, eliciting characteristic withdrawal-like behaviors and impacting cognitive function. Interestingly, prior exposure does not alter subsequent …


Detection Of Rotorcraft Landing Sites: An Ai-Based Approach, Abdullah Nasir Jul 2022

Detection Of Rotorcraft Landing Sites: An Ai-Based Approach, Abdullah Nasir

Theses and Dissertations

The updated information about the location and type of rotorcraft landing sites is an essential asset for the Federal Aviation Administration (FAA) and the Department of Transportation (DOT). However, acquiring, verifying, and regularly updating information about landing sites is not straightforward. The lack of current and correct information about landing sites is a risk factor in several rotorcraft accidents and incidents. The current FAA database of rotorcraft landing sites contains inaccurate and missing entries due to the manual updating process. There is a need for an accurate and automated validation tool to identify landing sites from satellite imagery. This thesis …


Measured Spectral, Directional Radiative Behavior Of Corrugated Surfaces, Kyle S. Meaker Jul 2022

Measured Spectral, Directional Radiative Behavior Of Corrugated Surfaces, Kyle S. Meaker

Theses and Dissertations

Spacecraft thermal control is entirely reliant upon radiative heat transfer for temperature regulation. Current methods are often static in nature and do not provide dynamic control of radiative heat transfer. As a result, modern spacecraft thermal control systems are typically 'cold-biased' with radiators that are larger than necessary for many operating conditions. Deploying a variable radiator as a thermal control technique in which the projected surface area can be adjusted to provide the appropriate heat loss for a given condition can reduce unnecessary heat rejection and reduce power requirements. However, the radiative behavior of the apparent surface representing the expanding/collapsing …


Enabling Successful Human-Robot Interaction Through Human-Human Co-Manipulation Analysis, Soft Robot Modeling, And Reliable Model Evolutionary Gain-Based Predictive Control (Mega-Pc), Spencer W. Jensen Jul 2022

Enabling Successful Human-Robot Interaction Through Human-Human Co-Manipulation Analysis, Soft Robot Modeling, And Reliable Model Evolutionary Gain-Based Predictive Control (Mega-Pc), Spencer W. Jensen

Theses and Dissertations

Soft robots are inherently safer than traditional robots due to their compliance and high power density ratio resulting in lower accidental impact forces. Thus they are a natural option for human-robot interaction. This thesis specifically looked at human-robot co-manipulation which is defined as a human and a robot working together to move an object too large or awkward to be safely maneuvered by a single agent. To better understand how humans communicate while co-manipulating an object, this work looked at haptic interaction of human-human dyadic co-manipulation trials and studied some of the trends found in that interaction. These trends point …


Simulation And Localization Of Autonomous Underwater Vehicles Leveraging Lie Group Structure, Easton Robert Potokar Jul 2022

Simulation And Localization Of Autonomous Underwater Vehicles Leveraging Lie Group Structure, Easton Robert Potokar

Theses and Dissertations

Autonomous underwater vehicles (AUVs) have the potential to dramatically improve safety, quality of life and general scientific knowledge. Our coasts, lakes and rivers are filled with various forms of marine infrastructure including dams, bridges, ship hulls, communication lines, and oil rigs. Each of these structures requires regular inspection, and current methods utilize divers, which is dangerous, expensive, and time consuming. AUVs have the potential to alleviate these difficulties and enable more regular inspection of these structures. Furthermore, there are significant scientific discoveries in the fields of geology, marine biology and medicine that AUV exploration of our oceans will enable. Since …


Microstructure Dependence Of The Thermal Radiative Properties In Yttria-Stabilized Zirconia Thermal Barrier Coatings, Yao Wang Jul 2022

Microstructure Dependence Of The Thermal Radiative Properties In Yttria-Stabilized Zirconia Thermal Barrier Coatings, Yao Wang

Theses and Dissertations

Thermal barrier coatings (TBCs) based on the yttria-stabilized zirconium dioxide (YSZ) are widely used in gas turbines. With increasing gas turbine combustion temperature to improve the thermal efficiency, the radiative heat transfer properties of YSZ coatings become important. Currently there is no clear understanding the relationship between the coating microstructure and the radiative properties. In this study, a hybrid computational approach is developed to invert the radiative properties form the spectral measurement. To investigate the relationship between the radiative properties and microstructure, a predictive model of the scattering coefficient is developed based on the pore size distribution obtained from SEM …


Preserving Users’ Privacy In Iot Systems Through Network-Based Access Control, Ahmed Khalid A Alhazmi Jul 2022

Preserving Users’ Privacy In Iot Systems Through Network-Based Access Control, Ahmed Khalid A Alhazmi

Theses and Dissertations

Privacy issues have plagued the rapid proliferation of the Internet of Things (IoT) devices. Resource-constrained IoT devices often obscure transparency for end-users. A lack of transparency and control complicates user trust in IoT. Additionally, a growing history of misuse and abuse exists in IoT. Notably, a smart TV has periodically scanned and collected users’ private information without consent, while power companies have adjusted the temperature of smart thermostats during heat waves. Due to a hybrid of distributed ecosystems within IoT, users cannot easily implement traditional access control over their devices as data flows within different nodes for storage and processing. …


Neurochemical, Molecular, And Behavioral Effects Of Intranasal Insulin, Jennifer Marie Erichsen Jul 2022

Neurochemical, Molecular, And Behavioral Effects Of Intranasal Insulin, Jennifer Marie Erichsen

Theses and Dissertations

Age-related cognitive decline (ARCD) is one of the most dreaded aspects of growing old and a public health concern. Unfortunately, there is currently no treatment that effectively ameliorates ARCD. In recent decades, intranasal insulin (INI) has demonstrated promising memory enhancements for rodents and individuals with Alzheimer’s disease, both in basic science research laboratories and multi-center clinical trials. Other studies have shown INI improves memory and cognition in healthy rodents and humans, indicating that INI may hold promise as a successful ARCD therapeutic. However, there is a glaring lack of evidence regarding how INI produces these effects. The goal of these …


Role Of Ahr In The Epigenetic Regulation Of Immune Cells In Lungs During Acute Respiratory Distress Syndrome, Bryan Latrell Holloman Jul 2022

Role Of Ahr In The Epigenetic Regulation Of Immune Cells In Lungs During Acute Respiratory Distress Syndrome, Bryan Latrell Holloman

Theses and Dissertations

Acute lung injury and acute respiratory distress syndrome (ALI/ARDS) arises from pulmonary inflammatory diseases that stem from direct and indirect activation of immune cells. Severe complications from ALI/ARDS arise when inflammatory mediators initiate an overzealous immune response leading to the destruction of lung epithelial cell barriers, which causes systematic oxygen deprivation. Infiltrating innate immune cells drive the immune response during the acute phase of a lung injury. However, I3C, a naturally occurring AhR ligand found in cruciferous vegetables such as broccoli, collard greens, and kale, plays a crucial role in suppressing inflammatory mediators through its immunomodulatory functionality, which regulates both …


Molecular Theoretical Model For Lipid Bilayers: Adsorption Of Lipidated Proteins On Lipid Bilayers As A Function Of Bilayer Composition And Curvature, Shauna Celeste Kennard Jul 2022

Molecular Theoretical Model For Lipid Bilayers: Adsorption Of Lipidated Proteins On Lipid Bilayers As A Function Of Bilayer Composition And Curvature, Shauna Celeste Kennard

Theses and Dissertations

Protein localization on biological membranes is motivated by either highly selective recognition of specific target membrane components or nonspecific attraction to general physical properties of the membrane, such as charge, lipid heterogeneity, and curvature. Here we discuss the interaction between lipidated proteins and lipid bilayer membranes from a comprehensive examination of how features of the membrane and its lipid constituents, including lipid composition, headgroup size, degree of tail saturation, tail length (bilayer thickness), and membrane geometry, affect the adsorption ability of the proteins. Of key importance is the strong interconnection among these compositional and morphological elements of the membrane in …


Learning Depth From Images, Zhenyao Wu Jul 2022

Learning Depth From Images, Zhenyao Wu

Theses and Dissertations

Estimating depth from images has become a very popular task in computer vision which aims to restore the 3D scene from 2D images and identify important geometric knowledge of the scene. Its performance has been significantly improved by convolutional neural networks in recent years, which surpass the traditional methods by a large margin. However, the natural scenes are usually complicated, and hard to build the correspondence between pixels across frames, such as the region containing moving objects, illumination changes, occlusions, and reflections. This research explores rich and comprehensive spatial correspondence across images and designs three new network architectures for depth …


Numerical Study Of The Effects Of Injector Geometry On The Performance Of Rotating Detonation Engines, Xavier Roy Jul 2022

Numerical Study Of The Effects Of Injector Geometry On The Performance Of Rotating Detonation Engines, Xavier Roy

Theses and Dissertations

A study of the impact of injector geometry on the performance of rotating detonation engines is performed. A numerical scheme is developed to represent the rotating detonation engine physics. In order to simulate the interaction between the chamber and the injectors, a multizone capability is implemented inside the numerical tool. The model is calibrated to represent a hydrogen-air detonation. The rotating detonation engine annular chamber is unwrapped and studied as a two-dimensional planar domain with a periodic boundary condition. Several numerical experiments are conducted. In particular, injection parameters are examined, such as the injector inflow to channel area ratio, injection …


Distributed Interdigital Capacitor (Idc) Sensing For Cable Insulation Aging And Degradation Detection, Md Nazmul Al Imran Jul 2022

Distributed Interdigital Capacitor (Idc) Sensing For Cable Insulation Aging And Degradation Detection, Md Nazmul Al Imran

Theses and Dissertations

Nuclear power plants (NPPs) contain myriad power, control, instrumentation, and other types of cables. The polymer insulation and jacket materials of such cables degrade over time due to operation and environmental conditions e.g., heat, humidity, and radiation. Since the life span of NPPs may extend beyond 40-50 years regular monitoring of cable insulation and jacket polymers is critical to ensure safe and reliable operation. The agingrelated degradation of cables causes changes in the relative permittivity or dielectric constant of the insulation and jacket materials. Capacitor sensors, if properly designed and developed can measure this change and thus can provide an …


Long Non-Coding Rna Pvt1 – An Exploratory Study In Ovarian And Endometrial Cancer, Kevin Tabury Jul 2022

Long Non-Coding Rna Pvt1 – An Exploratory Study In Ovarian And Endometrial Cancer, Kevin Tabury

Theses and Dissertations

Gynecological cancers, ovarian and endometrial cancer, are still leading causes of cancer-related death in women worldwide. Early detection methods as well as treatment resistance remain a challenge. Long non-coding RNAs (lncRNAs) are emerging as therapeutic targets with diagnostic and prognostic potential with lncRNA PVT1 being one of them.

Here I test and demonstrate the role of PVT1 in ovarian cancer growth and metastasis. PVT1 is amplified and overexpressed in ovarian cancer and has predictive value for survival and response to targeted therapeutics. We find that expression of PVT1 is regulated by tumor cells in response to cellular stress, particularly loss …


Understanding The Reaction Kinetics Of Polyurethane Flexible Foam, Caitlin Alma Mckinnon Jul 2022

Understanding The Reaction Kinetics Of Polyurethane Flexible Foam, Caitlin Alma Mckinnon

Theses and Dissertations

Polyurethane flexible foam is used throughout daily life predominantly as cushions for chairs and mattresses. Currently new foams are made through extensive research and development via trial and error. There are many reactions interacting with each other during the polyurethane generation process. The numerous reactions create difficulty in modeling and predicting the physical attributes of a foam. This thesis explores the kinetics associated with each reaction to generate a simple model to understand the reaction kinetics with the addition of some additives. This thesis focused on creating the foams in a real-world environment, including allowing ambient water vapor to be …


Electromagnetic Interference Shielding Effectiveness Of A Layered System Consisting Of A Carbon Nano-Reinforced Polymer Composite Coated With Metal Oxide And Graphite, Veronica Montserrat Serrato Jul 2022

Electromagnetic Interference Shielding Effectiveness Of A Layered System Consisting Of A Carbon Nano-Reinforced Polymer Composite Coated With Metal Oxide And Graphite, Veronica Montserrat Serrato

Theses and Dissertations

In this study, the electromagnetic interference (EMI) shielding effectiveness (SE) of vapor grown carbon nanofiber (VGCNF) reinforced polyvinylidene difluoride (PVDF) composite and PVDF/VGCNF thermally sprayed with magnetite (Fe3O4) and graphite has been investigated. EMI SE evaluations were performed in the frequency range of 30 kHz-1.5 GHz. The developed nanocomposite (NC) system was fabricated by high shear mixing using a Banbury type mixer. The material was then subjected to compression molding. Subsequently, the films were thermally sprayed using Fe3O4/graphite powder. The NC and coated NC films had average thicknesses of 0.82 mm and 0.93 mm, respectively. The NC films were subjected …


Optimizing Left Ventricular Assist Device Hemodynamics Via Patient Specific Computational Analysis, Jasmine Josefina Martinez Jul 2022

Optimizing Left Ventricular Assist Device Hemodynamics Via Patient Specific Computational Analysis, Jasmine Josefina Martinez

Theses and Dissertations

The best treatment for patients with end stage heart failure is a heart transplant but given the scarcity of donor hearts, a promising alternative treatment has become left ventricular assist devices (LVAD). However, complications such as right heart failure, stroke, and adverse hemodynamic outcomes continue to occur. This thesis will cover investigations into continuous flow LVAD treatment optimization techniques to improve patient outcomes. Optimization techniques explored include an in-house developed optimization algorithm that is completed in three phases on a computational lumped parameter model that is representative of the cardiovascular system using an electrical circuit analogy. This three-phase optimization technique …


Evaluating Nas Delay Impacts From Orbital Launch Operations At Cape Canaveral And Optimizing Launch Windows, Tanner Jordin Furr Jul 2022

Evaluating Nas Delay Impacts From Orbital Launch Operations At Cape Canaveral And Optimizing Launch Windows, Tanner Jordin Furr

Theses and Dissertations

The purpose of this study was to determine if there was an impact of Part 121 arrival delays into Orlando International Airport (MCO) due to orbital space launch operations at Cape Canaveral. U.S. Government archival data spanning ten months and over 22,000 flights was accessed and categorized into three research questions by day of week, time of day, and whether or not an orbital space launch occurred during the established time frame. Inferential analysis using the one-way ANOVA (RQ1) and two-way ANOVA (RQ2 and RQ3) was conducted and found no significant differences in average Part 121 arrival delays into MCO …


Propellant Optimization For A Pulsed Solid Propellant Thruster System For Small Satellites, Timothy Aaron Blackman Jul 2022

Propellant Optimization For A Pulsed Solid Propellant Thruster System For Small Satellites, Timothy Aaron Blackman

Theses and Dissertations

CubeSats have historically been used mostly for education, technology demonstration, remote sensing, and amateur radio relay applications. Yet with increased maneuvering capability, they can become effective tools in on-orbit servicing and space debris removal. To make this a reality, CubeSats must be enabled to perform effective rendezvous and proximity operations with non-cooperative client objects, requiring a high-thrust propulsion system. As CubeSats are inherently constrained in their volume and mass, any propulsion system must feature a high specific impulse to minimize the propellant mass requirement. As CubeSats are commonly launched as secondary payload, the use of pressurized propellant tanks is typically …


Predicting The Remaining Service Life Of Railroad Bearings: Leveraging Machine Learning And Onboard Sensor Data, Leonel Villafranca Jul 2022

Predicting The Remaining Service Life Of Railroad Bearings: Leveraging Machine Learning And Onboard Sensor Data, Leonel Villafranca

Theses and Dissertations

By continuously monitoring train bearing health in terms of temperature and vibration levels of bearings tested in a laboratory setting, statistical regression models have been developed to establish relationships between the sensor-acquired bearing health data with several explanatory factors that potentially influence the bearing deterioration. Despite their merits, statistical models fall short of reliable prediction accuracy levels since they entail restrictive assumptions, such as a priori known functional relationship between the response and input variables. A data-driven machine learning algorithm is presented, which can unravel the nonlinear deterioration model purely based on the bearing health data, even when the structure …


Role Of Epigenome In Regulation Of Inflammation By Ahr Ligands 2,3,7,8-Tetrachlorodibenzo-P-Dioxin And 6-Formylindolo[3,2-B] Carbazole, Alkeiver Cannon Jul 2022

Role Of Epigenome In Regulation Of Inflammation By Ahr Ligands 2,3,7,8-Tetrachlorodibenzo-P-Dioxin And 6-Formylindolo[3,2-B] Carbazole, Alkeiver Cannon

Theses and Dissertations

Autoimmune Hepatitis (AIH) is a chronic inflammatory disease of the liver mediated by immune cells and characterized by a variety of parameters including circulating autoantigens, elevated immunoglobulin G (IgG) and aminotransferases, and interface hepatitis. Unfortunately, despite treatment with broadly immunosuppressive drugs, the disease progresses to cirrhosis and end-stage liver disease in several cases. In order to develop a more specific treatment, the mechanisms governing the liver injury resulting from inflammation and autoimmunity need to be elucidated.

For decades, activation of Aryl Hydrocarbon Receptor (AhR) was excluded from consideration as a therapeutic approach due to the potential toxic effects of AhR …


Sex Differences And Potential Non-Invasive Treatments For Calcific Aortic Valve Disease, Henry Pascal Helms Jul 2022

Sex Differences And Potential Non-Invasive Treatments For Calcific Aortic Valve Disease, Henry Pascal Helms

Theses and Dissertations

Calcific Aortic Valve Disease (CAVD) is a progressive heart disease that ranges from aortic valve sclerosis to aortic valve stenosis. It is characterized by intense calcification and compromised valve function. CAVD affects 25% of people older than 65 and 50% of people older than 85. These rates are expected to increase in the United States due to higher levels of obesity and diabetes, as well as an aging population. CAVD is the leading cause of valve replacement surgery. Annual healthcare costs for these valve replacements are currently estimated to be approximately 2 billion dollars. There are currently no medications approved …


Non-Intrusive Microwave Surface Wave Technique For Cable Damage And Aging Detection, Ahmed Shah Arman Jul 2022

Non-Intrusive Microwave Surface Wave Technique For Cable Damage And Aging Detection, Ahmed Shah Arman

Theses and Dissertations

Power plants, power distribution and transmission networks, automobiles, aircrafts, trains, industrial manufacturing plants etc. use a variety of cables and wires. The insulation and jacket polymer materials of cables can degrade over time due to operational stressors and environmental conditions. Materials may age, corrode, get chaffed and go missing which if remain undetected and unaddressed can result in major failures. Insulation degradation or damage detection from a distance normally involves the application of direct contact reflectometry techniques. This requires the cable to be disengaged and a diagnostic signal to be directly applied to a cable with a return path. While …


Hybrid Theory-Machine Learning Methods For The Prediction Of Afp Layup Quality, Christopher M. Sacco Jul 2022

Hybrid Theory-Machine Learning Methods For The Prediction Of Afp Layup Quality, Christopher M. Sacco

Theses and Dissertations

The advanced manufacturing capabilities provided through the automated fiber placement (AFP) system has allowed for faster layup time and more consistent production across a number of different geometries. This contributes to the modern production of large composite structures and the widespread adaptation of composites in industry in general and aerospace in particular. However, the automation introduced in this process increases the difficulty of quality assurance efforts. Industry available tools for predicting layup quality are either limited in scope, or have extremely high computational overhead. With the advent of automated inspection systems, direct capture of semantic inspection data, and therefore complete …


Image Restoration Under Adverse Illumination For Various Applications, Lan Fu Jul 2022

Image Restoration Under Adverse Illumination For Various Applications, Lan Fu

Theses and Dissertations

Many images are captured in sub-optimal environment, resulting in various kinds of degradations, such as noise, blur, and shadow. Adverse illumination is one of the most important factors resulting in image degradation with color and illumination distortion or even unidentified image content. Degradation caused by the adverse illumination makes the images suffer from worse visual quality, which might also lead to negative effects on high-level perception tasks, e.g., object detection.

Image restoration under adverse illumination is an effective way to remove such kind of degradations to obtain visual pleasing images. Existing state-of-the-art deep neural networks (DNNs) based image restoration …


Cross Domain Semantic Segmentation, Xinyi Wu Jul 2022

Cross Domain Semantic Segmentation, Xinyi Wu

Theses and Dissertations

As a long-standing computer vision task, semantic segmentation is still extensively researched till now because of its importance to visual understanding and analysis. The goal of semantic segmentation is to classify each pixel of images based on the pre-defined classes. In the era of deep learning, convolutional neural networks largely improve the accuracy and efficiency of semantic segmentation. However, this success is achieved with two limitations: 1) a large-scale labeled dataset is required for training while the labeling process for this task is quite labor-intensive and tedious; 2) the trained deep networks can get promising results when testing on the …


Cnn-Based Semantic Segmentation With Shape Prior Knowledge, Yuhang Lu Jul 2022

Cnn-Based Semantic Segmentation With Shape Prior Knowledge, Yuhang Lu

Theses and Dissertations

Semantic segmentation that aims at grouping discrete pixels into connected regions is a fundamental step in many high-level computer vision tasks. In recent years, Convolutional Neural Networks (CNNs) have made breakthrough progresses in public semantic segmentation benchmarks. The ability of learning from large-scale labeled datasets empowers them to generalize to unseen images better than traditional nonlearning-based methods. Nevertheless, the heavy dependency on labeled data also limits their applications in tasks where high-quality ground truth segmentation masks are scarce or difficult to acquire. In this dissertation, we study the problem of alleviating the data dependency for CNN-based segmentation with a focus …