Engineering Commons^™

A Semantic Web Approach To Fault Tolerant Autonomous Manufacturing, Fadi El Kalach

Theses and Dissertations

The next phase of manufacturing is centered on making the switch from traditional automated to autonomous systems. Future Factories are required to be agile, allowing for more customized production, and resistant to disturbances. Such production lines would have the capability to reallocate resources as needed and eliminate downtime while keeping up with market demands. These systems must be capable of complex decision making based on different parameters such as machine status, sensory data, and inspection results. Current manufacturing lines lack this complex capability and instead focus on low level decision making on the machine level without utilizing the generated data …

Detecting Physiological Concentrations Of Alzheimer’S Associated Amyloid-Β Protein Utilizing A Cell-Based Response, Brittany Elizabeth Watson

Theses and Dissertations

Alzheimer’s disease (AD) is characterized symptoms of cognitive impairment resulting from blood-brain barrier (BBB) breakdown and neuronal cell death. AD is associated with aggregated amyloid-β (Aβ) plaques deposited around brain vasculature and within the brain. Changes in the brain occur up to 20 years before symptoms arise; however, there is currently no pre-symptomatic detection method available for AD. An intact BBB requires tight junction proteins (TJs) that render relatively high transendothelial electrical resistance (TEER). AD-associated breakdown of the BBB correlates with vascular Aβ deposition, suggesting that aggregated, pathological Aβ can modulate TEER. We explore leveraging this cellular response for early …

Characterization Of The Spatial And Temporal Dynamics Of Floodplain Surface-Water Circulation, Shailesh Cyriel Van Der Steeg

Theses and Dissertations

Floodplains are spatially complex landscapes with a variety of surface features and landforms. These low-relief, low-gradient landscapes may contain extensive networks of well-defined channels and topographically connected depressions, and in some cases, the channels originate as cuts across levees or banks of the main river, referred to as through-bank channels. Corresponding complex patterns of inundation and flow have been detected through remote sensing and in field observations. The complex floodplain flows in response to the passing of flood waves is, however, poorly quantified. This work aims to increase fundamental understanding of floodplain flows and to highlight controls on floodplain wetting, …

Mathematical Analysis Of Electrochemical Systems, Shiv Krishna Reddy Madi Reddy

Theses and Dissertations

A solid electrolyte interphase (SEI) growth model is developed in a mixed modethat contains solvent diffusion through the SEI layer and corresponding solvent reduction kinetics at the SEI/electrode interface. The governing equations are solved by the Landau transformation, which makes the moving layer fixed to predict the open circuit potential, SEI layer thickness, and capacity loss. The estimated parameters fitted with experimental data from the literature are computed using COMSOL and MATLAB. Results show that the mixed mode model predicts lower capacity loss and thinner SEI layer due to its growth under open circuit conditions than previously reported by others. …

Quantized State Simulation Of Electrical Power Systems, Joseph Micah Hood

Theses and Dissertations

An alternative is proposed to the current state-of-the-art simulation methods for the transient simulation of electrical power systems. The proposed method combines the Latency Insertion Method (LIM), the Quantized Discrete Event Specification (QDEVS), and the Quantized State System (QSS) method of integration. Using LIM, the power system state equations are decoupled in a way that allows the formulation of the system into a QDEVS-compliant model, which can then be directly solved with various QSS integration techniques. This combination of methods is called the Quantized DEVS-LIM method, or simply, QDL. A key feature of QDL is the asynchronous updates of all …

Spin Mediated Topological Black Hole In Acoustic Metamaterials Near Dirac-Like Cone Frequencies., Mustahseen Mobashwer Indaleeb

Theses and Dissertations

A unique bulk-boundary distinction and acoustic topological phenomena is discovered and explained in this dissertation. The overall objective was to discover the hidden physics, dynamic and mechanics of acoustic wave behavior that causes the formation of extremely rare ‘Topologically protected Black Hole’ (TBH) in acoustic microarchitecture metamaterials. This behavior is immensely valuable for numerous mechanical and civil engineering applications where acoustic insulators are required to create sound-free or vibration-free exterior surfaces. On the other hand, to contain the energy within the structure, for impact mitigation and energy absorption in vehicles, space crafts, aircrafts, and civil infrastructures such materials will be …

Experimental Observation Of Sphere Symmetric Isolated Single Droplet Combustion In A Converging Channel, Mason Carrington Williams

Theses and Dissertations

Spherically symmetric isolated single droplet combustion has been observed mainly in microgravity conditions. This study sought to determine if spherically symmetric combustion can be produced in a lab-scale experiment using flow acceleration to counteract the effects of buoyancy. The experiment was conducted in a converging channel that decreased in width along its length to accelerate the flow and limit the formation of a boundary layer. The rate at which the area decreased was governed by the initial velocity condition set at the channel inlet.

The droplets were generated using a piezoelectric actuator which forced fuel out of an injector with …

Semantics-Based Data Security Models, Theppatorn Rhujittawiwat

Theses and Dissertations

In this dissertation, we studied how an adversary could attack databases and how the system could prevent or recover from such an attack. Our motivation to improve the current security capabilities of database management systems. We provided better recovery capabilities of database management systems by incorporating data provenance. We also expand our study to express security and privacy needs of data in the Internet of Things (IoT) environments such as a smart home environment. For this, we proposed a stream data security model to theoretically represent the data in the IoT network. We built a dynamic authorization model on our …

High-Performance Wide Bandgap Semiconductor Power Modules Enabled By Advanced Two-Phase Mini-Channel Cooling, Bo Tian

Theses and Dissertations

There is a widespread need for high performance wide bandgap power modules in both commercial and military applications. However, given the rapid advancements of wide bandgap power module technology, conventional cooling solutions have not kept up and do not provide the thermal management performance needed for high power density. Based on the two-phase cooling approach, two-phase microchannels operating at low fluid flow rates with low pressure drops have huge potential in enabling higher power density applications. Several studies have illustrated the potential great advantages of two-phase cooling compared to single-phase cooling in terms of maximum device temperature, spatial thermal distribution …

Deep Learning Based Fault Diagnosis And Prognosis For Bearing, Guangxing Niu

Theses and Dissertations

Rolling element bearings are critical components in industrial rotating machines. Faults and failures of bearings can cause degradation of machine performance or even a catastrophe. Therefore, it is significant work to perform bearing fault diagnosis and prognosis (FDP) reliably and effectively. Diagnosis aims to detect and estimate the fault state of bearing in real-time. Prognosis aims to conduct a long-term prediction to predict the fault evolution and estimate the remaining useful life (RUL) of the bearing.

Deep learning (DL) based FDP methods have become an important branch of bearing FDP methods due to their powerful capabilities in feature automatic learning, …

Templates To Transition: Making Solar-Generated Electricity Accessible For Lagos Residents, Adeola O. Adebajo

Senior Theses

According to the EPA, direct energy production results in at least 25% of the world’s emissions. This refers to emissions produced by burning coal, natural gas, and oil for electricity and heat. With the increasing effects of climate change, sustainable energy is becoming increasingly important as the world shifts away from fossil fuels. However, implementation of renewable energy sources is not as fast or as widespread as necessary. This paper aims to identify feasible solutions to the problem of renewable energy affordability in Nigeria especially in growing megacities like Lagos to ensure long lasting and climatefriendly energy sources. Two major …

Leveraging Automated Fiber Placement Computer Aided Process Planning Framework For Defect Validation And Dynamic Layup Strategies, Joshua Allen Halbritter

Theses and Dissertations

Process planning represents an essential stage of the Automated Fiber Placement (AFP) workflow. It develops useful and efficient machine processes based upon the working material, composite design, and manufacturing resources. The current state of process planning requires a high degree of interaction from the process planner and could greatly benefit from increased automation. Therefore, a list of key steps and functions are created to identify the more difficult and time-consuming phases of process planning. Additionally, a set of metrics must exist by which to evaluate the effectiveness of the manufactured laminate from the machine code created during the Process Planning …

Development Of System Pressure Drop Calculation Methods For Dilute Phase Pneumatic Conveying, Ross Daniel Gorman

Theses and Dissertations

This work is focused on dilute and dense phase pneumatic conveying of bulk solids. The motivation of this work is to use industrial data to scale up existing models for pressure drop in pneumatic conveying systems, determine which models best predict pressure drop in full conveying systems, and find the empirical coefficients that go with these models.

Several major research objectives were accomplished by this work. First, system pressure drop methods were evaluated in this research. Other researchers have focused on single pipe section type pressure drops. Second, the data used in this research both for the machine learning evaluations …

Gluten Free Diet Ameliorates Si Enteropathy In Iga Deficient Mice, Ryan Albert William Ball

Theses and Dissertations

Secretory IgA is the most abundant antibody in the intestinal mucosal and functions as the first line of defense against pathogens and micro-organisms in the gut. Selective IgA deficiency is the most common form of antibody deficiency. Clinically, IgA deficient patients are largely asymptomatic, they are however at a higher risk of developing certain inflammatory conditions like Celiac disease; an SI-specific enteropathy triggered by exposure to dietary gluten. Interestingly, celiac patients are 10-15 times more likely to have an IgA deficiency. Recent studies have shown that IgA^-/- mice develop enteropathy specifically in the ileum. We confirmed this phenotype in …

Design Of A Tvsa Cycle For Co2 Removal From Spacecraft Cabins Using A Structured Adsorbent, Pravin Bosco Charles Antony Amalraj

Theses and Dissertations

Pressure Swing Adsorption (PSA) and Temperature Swing Adsorption (TSA) are some of the most used cyclic adsorption technologies that is used for separating gas components from its mixture. Carbon Dioxide Removal Assembly (CDRA) in the International Space Station (ISS) facilitates the continuous removal of CO2 by the cyclic adsorption process. The use of structured adsorbents has drawn attention due its several advantages over traditional beaded adsorbents. This work evaluates the role of different design variables on the effective thermal conductivity of a structured adsorbent bed for its possible application in a temperature swing adsorption (TVSA) process for space applications. The …

The Impact Of Using Tanks For The Equalization Step On The Performance Of A Psa Process, Behnam Fakhari Kisomi

Theses and Dissertations

The pressure equalization step between two adsorption beds is a key cycle step in many pressure swing adsorption (PSA) processes. It involves connecting two beds together, or two beds and a tank as a medium. The utilization of tanks for equalization in a bed-to-tank-to-bed (BTB) configuration could be advantageous to reduce the number of beds in PSA cycle. In this study, a binary gas mixture A and B, with A more strongly adsorbed than B, was used for the investigation of Stafstrom-type PSA cycles with bed-to-bed (BB) and bed-to-tank-to-bed (BTB) equalization steps using linear isotherm and isothermal equilibrium theory. For …

Neurodevelopmental And Transient Impacts Of Brain Kynurenic Acid Elevation And Sleep-Wake Behavior, Katherine Rentschler

Theses and Dissertations

Sleep is vital for healthy cognition and mood. Sleep dysregulation is implicated in psychiatric disorders such as schizophrenia and bipolar disorder. Sex differences in sleep and arousal dysregulation are prominent in patients with psychotic disorders. Elevated levels of the neuroactive tryptophan metabolite, kynurenic acid (KYNA), have been found in cerebrospinal fluid and postmortem brain tissue samples from patients with psychotic disorders. KYNA is an astrocyte derived antagonist at N-methyl-D-aspartate (NMDA) glutamate receptors and α7 nicotinic acetylcholine (α7nACh) receptors. KYNA is synthesized in the brain from its biological precursor, kynurenine, via the enzyme kynurenine aminotransferase II (KAT II), a potential therapeutic …

Role Of Sediment Type, Concentration, And Salinity On Clay Flocs, Ryan Michael Johnson

Theses and Dissertations

Experiments were performed to study floc formation in water bodies. In particular, the study aimed to systematically identify effects of water depth, time, salinity, initial clay concentration, and clay type on floc formation and settling. Three sediment types were chosen for this research are Three sediment types were chosen for this research: silica powder, with particle sizes comparable to clay flocs, kaolin clay and bentonite clay. Silica was chosen as a control because it did not form flocs. Kaolin represented low activity clay; bentonite was chosen as the high activity clay. Experiments lasted up to 48 hours. Graduated cylinders were …

Timing Deterministic Structural Model Updating Considering Impact And Fatigue Damage, Jason Michael Smith Jr.

Theses and Dissertations

Naval ship structures such as support trusses, hull sections, driving machinery, and load-bearing beams are subjected to various damage states that develop on short-term (i.e. impact) and long-term (i.e. fatigue) timescales. Naval structures fitted with a structural health monitoring system with damage detection abilities will enable appropriate real-time adjustments to the ships’ posture and control policies and thus have increased survivability and lethality. A digital twin can provide real-time condition assessment of naval structures when conjoined with a decision-making framework will increase naval ship survivability through informed response management. A fundamental challenge for the development of digital twins is reliable …

Vision Controlled Autonomous Stakebot For Driving Stakes And Its Digital-Twin, Corey Lee Leydig

Theses and Dissertations

In this thesis a novel vision-based AI driven autonomous ‘StakeBot’ is proposed to serve the agricultural 4.0 industries of the future. In recent years supply, demand and production of vegetables that are harvested from plants with weak stems like bell pepper, tomato, eggplant has been significantly up by several fold. With growing demand and new green-house establishments across the country production of vegetables will require a tremendous number of labors which will be hard to supply soon. To overcome the issues in addition to the labor shortages, automation through robotics will be the only viable solution. Plants like bell peppers …

An Artificial Intelligence Approach To Fatigue Crack Length Estimation From Acoustic Emission Signals, Shane T. Ennis

Theses and Dissertations

As in service aircraft begin to age and fatigue, a method for evaluating the operational life they are currently operating under and have remaining comes into question. Structural health monitoring is (SHM) is a popular method of structural analysis with growing interest in the aerospace industry. SHM is capable of damage assessment and structural life estimations.

The ultimate goal of the research presented in this thesis is to develop a methodology of classifying the length of a fatigue crack though the use of machine learning. The thesis has three major chapters as described below.

The first chapter deals with the …

An Autonomous Aerial Drone System For Water Fluorescence Mapping And Targeted Sampling, Kazi Ragib Ishraq Sanim

Theses and Dissertations

At present, aerial drones, also known as Uncrewed Aircraft Systems (UAS) or Unmanned Aerial Vehicles (UAV), are increasingly used in time and effort-heavy scientific exploration applications. One such application is inspecting the physical, chemical, and biological state of water bodies. This thesis presents a novel autonomous system capable of sensing water properties and collecting up to three 250 mL water samples from multiple sampling locations. The system features a customized aerial drone with an in-house built fluorescence sensor and pumping mechanism. It can also map the gradient of fluorescent content across the body of water to determine the best sampling …

Nondestructive Damage Detection And Stress Corrosion Crack Mitigation In Stainless Steel Plates, Andrew Philip Campbell

Theses and Dissertations

The ability to inspect and detect damage within a structure without permanent damage has broad appeal in a range of engineering applications from aerospace structures to nuclear facilities. Non-destructive evaluation (NDE) using guided ultrasonic Lamb waves has growing potential and popularity in these fields. Lamb waves are known for being sensitive to material properties and various defects across the thickness such as cracks in metallic structures and delamination or debonding in composite structures. Research has also been done on the development of fully non-contact system that generates and detects Lamb waves, particularly focused on the use of pulsed laser for …

Actuation And Sensing Applications Of Piezoelectric Transducers, Connor Griffin

Theses and Dissertations

Piezoelectric materials, defined by their ability to display a charge across their surface in response to mechanical strain, are great for use in actuation and sensing applications. Actuation applications include acoustic devices, motors and vibration damping while sensing applications include pressure sensors, medical devices, energy harvesting and structural health monitoring (SHM). The use of piezoelectric actuation and sensing across the lifecycle of aerospace metals is currently an expanding field with use cases beginning with the manufacturing process and ending with SHM.

The research presented in this thesis had three goals: (i) to develop methods for implementation of piezoelectric actuation in …

Comprehensive Process Planning Optimization Framework For Automated Fiber Placement, Alex Ryan Brasington

Theses and Dissertations

Advanced composite materials came about in 1966 and have since been widely used due to the possibility of superior structural performance while also achieving weight reductions. Such opportunities have led to composite materials being used to fabricate complex components, often in the aerospace sector. Most components, especially in aviation, are on a large scale and are outside the capabilities of traditional composite manufacturing techniques. Traditional manufacturing methods are also labor intensive, time consuming, have a high level of material scrap, and are prone to human error. This has led to the need for innovative manufacturing solutions to withstand the ever-increasing …

New Perspectives And Insights Into Direct Epoxidation Of C3H6 Using O2 And Ag Based Catalysts And Measurement Of Active Ag Site Concentration Of Promoted Ag Catalyst For C2H4 Epoxidation By H2 Pulse Titration Over Oxygen Pre-Covered Surface, Md Masudur Rahman

Theses and Dissertations

Direct epoxidation of C₃H₆ using molecular O₂ and Ag catalysts to produce propylene oxide (PO) selectively is a long-sought goal in the field of heterogeneous catalysis. In the early 1990’s Scientists at ARCO reported promising results of 58 – 59% selectivity to PO at 3.2% conversion of C₃H₆ over an unusual composition of 54.0 wt% Ag, 2.0 wt% K⁺, 0.5 wt% Mo and balance CaCO₃. Feed additives of ethyl chloride (EtCl), nitric oxide (NO) and CO₂ were stated necessary to achieve the claimed high PO selectivities. The roles …

Physics-Based And Behavioral Models For Fuel Cells, Charles Chima Anyim

Theses and Dissertations

In recent times there has been renewed interest in fuel cells for electricity production, especially for transportation applications. Fuel cells are attractive because the electricity production process from chemical energy does not cause pollution, and no carbon emissions occur. In this work, we will focus on Proton Exchange Membrane (PEM) fuel cells that use hydrogen and oxygen to generate electricity, producing only electricity, heat and water. If hydrogen can be produced in a green, non-polluting way, fuel cells can truly be an environmentally benign energy source.

In this work, we will look at the modeling of a fuel cell system. …

Novel Structures And Thin Film Techniques For Reconfigurable Rf Technologies With Improved Signal Integrity, Jinqun Ge

Theses and Dissertations

Over the past several decades, wireless communications have been tremendously developed with multiple frequency bands, standards, and functions to provide more convenient communication services. Nowadays, commercial wireless devices, especially customer premises equipment, are required for smaller size, higher integration, and higher data rates to meet the ever-increasing demands of communications. The transceiver front ends inside these devices need to provide high-speed and high-quality communication services without a substantial increase in cost and size. Hence, the primary objective of this research is to develop a few miniaturized, multifunctional, and reconfigurable RF technologies and to provide several signal integrity and heat dissipation …

Multidimensional Transport-Coupled Numerical Investigation Of Non-Premixed Low-Temperature Flame In Atmospheric And High-Pressure Systems, Sudipta Saha

Theses and Dissertations

Gas-phase chemical reactions coupled with multidimensional fluid flow and heat and mass transport are found in various applications, i.e., from conventional engine applications to novel combustion techniques. With the goal of understanding such complex coupling in reacting flow systems, this dissertation work focuses on developing multi-physics simulation frameworks to investigate the effect of multidimensional transport on flame dynamics. This study primarily focuses on the modeling and simulation of low temperature flame formation in i) a canonical experimental setting with counterflow burners and ii) a supercritical water medium (i.e., hydrothermal flame).

In the first part of the dissertation, simulations of the …

Development And The Use Of A New Kinetically Limited Linear Driving Force Model For Diffusion-Based Adsorptive Separations, Sulaimon Adedayo Adegunju

Theses and Dissertations

A new kinetically limited linear driving force (KLLDF) model, in terms of a modified extended Langmuir (EL) isotherm, was developed. This KLLDF model augments the equilibrium driving force in the linear driving force (LDF) model in such a way that the equilibrium loading of each component in the LDF model depends on the actual, kinetically limited, loading of the other components in a gas mixture, not their partial pressures. In contrast, the LDF model assumes the presence of a slower diffusing adsorbate in a gas mixture affects the equilibrium of a faster diffusing adsorbate in a pore structure via its …