Engineering Commons^™

Lagrange Multipliers As A Metric For Early-Stage Shipboard Power System Design, Magdalen A. Barnes

Theses and Dissertations--Electrical and Computer Engineering

Integrated power systems are essential in the operation of electric ships and must function under a diverse range of conditions. In addition to routine operation, ships should be prepared to respond to challenging events that require significant amounts of power. Demanding scenarios, coupled with complex and interconnected power systems, present challenging issues. The power and energy ratings of equipment are crucial factors in the operational success of the ship; however, to meet economic constraints, balance between performance and cost must be upheld. Details regarding equipment models and specifications are typically unavailable during early-stage design. Power system modeling and simulation can …

Characterization And Modeling Of Polyphase Machines And Power Conditioning Components, Nathan Lockhart

Electrical Engineering Dissertations - Archive

Microgrid power configurations have become increasingly prevalent in recent power systems due to the rise of power electronic energy generation, energy storage, and the many diverse electrical demands. Microgrids offer numerous advantages over traditional power electronic networks, which rely on large rotating generators to supply power over extensive distances to multiple users. Remote power grids are particularly beneficial for smaller networks that may be isolated or have unique power requirements, often incorporating energy storage to enhance operational flexibility. Advances in power electronics, such as medium voltage DC distribution, are enhancing the reliability, redundancy, and integration capabilities of isolated microgrids.

To …

Immersive Modeling Of Water Banking Elicits Local Knowledge To Explore Strategies To Get More Water To Great Salt Lake, Hadia Akbar, David E. Rosenberg

Civil and Environmental Engineering Student Research

This study used immersive online collaborative modeling of water banking to explore strategies to get more water to the declining Great Salt Lake (GSL). In a model session, each collaborator immersed in a water user role. They articulated a strategy to consume and bank water. Then they adapted their strategy in response to their available water, others’ choices, and the real-time discussion of choices. Collaborators included 29 farmers, ranchers, practitioners, and experts. Collaborators who personified agricultural users had the most varied strategies. They balanced economic viability, long-term sustainability, and land preservation. Pricing water was challenging, with prices ranging from $15 …

Multirotor Aerial Vehicle Morphology Design, Modeling, And Control, Samuel Allen Dauchert

Theses and Dissertations

Multirotor aerial vehicles (MAVs) have seen explosive popularity since the early 2000s, with microprocessors enabling small-scale Autonomous Aerial Vehicles (AAVs) or First Person Aerial Vehicles (FPVs). Additionally, the use of these MAVs in commercial applications has continued to grow since then with expansion into delivery, search and rescue, and smart farming applications. With this rise in popularity, specialized MAVs have undergone development for these applications due to the environments in which these vehicles operate.

From this development, a new area of Morphological Multirotor Aerial Vehicles (MMAVs) has emerged. Unlike traditional MAVs, these platforms adjust their shape based on environmental factors. …

Modeling And Simulation Of Carbon-Neutral Strategies For Methanol Production, Omar Almaraz Barrios

Graduate Theses, Dissertations, and Problem Reports (ETD)

Methanol is a versatile chemical that can be used as a fuel, a solvent, a feedstock for other chemicals, and a hydrogen carrier. Methanol production from natural gas, which is mainly composed of methane, is a well-established process that involves steam reforming, methanol synthesis, and methanol purification. However, this process is energy-intensive and emits large amounts of carbon dioxide, which contributes to global warming and climate change. Therefore, there is a need for alternative methods of methanol production that are more efficient and environmentally friendly. The overall objective of this research is to develop simulation models of two novel methanol …

Tracking Control Of A String Actuated Soft Trunk Robot Using State-Space Modeling, Jacob Trivisonno

Open Access Master's Theses

Soft robots, primarily composed of compliant materials, exhibit highly complex and nonlinear dynamics, making precise control a significant challenge. Traditional control methods often struggle with these complexities, requiring more advanced and data-driven methods. In our previous work, “Automatic Control of a Soft Trunk Robot Actuated by Strings” [1], a proportional controller was developed to drive the steady-state tracking error to zero. While this method was effective, it required time-consuming manual tuning and was not easily adaptable to physical modifications of the robot.

To address these limitations, this research implements gain-scheduled feedback control with state-space models calculated through a multiple linear …

In-Situ Informed Modeling And Characterization Of Friction And Built-Up Edge In Machining Of Aerospace Alloys, Avery Hartley

Theses and Dissertations--Mechanical and Aerospace Engineering

Machining is by no means a new manufacturing process. However, it is separated from other traditional deformation processes by its extreme temperatures and strain rates. The function and life of a multitude of products and mechanical components are dependent on the material properties induced by changing the surface through machining. Furthermore, the tools used within machining are often expensive and material reserves are sparse. The understanding the mechanics of the machining process, especially related to the friction of the tool and workpiece, helps to further the life of tools and parts to minimize economic and environmental impact.

Current friction modeling …

High-Frequency Accurate Dual-Side Equivalent Circuit Model For Transformers, Reza Vahdani, Junyong Park, Manish Kizhakkeveettil Mathew, Zhekun Peng, Chiuk Song, Hyucksu Kweon, Jiang Lijun, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

This study delves into the modeling of a transformer in the frequency range of 100 KHz to 30 MHZ. The coupling coefficient was considered as a function of leakage and self-inductance and incorporated in the optimization process of transformer modeling in the proposed method. The equivalent circuit focused on the critical aspects of leakage inductance, parasitic capacitance, and winding effects. At first, the winding effect of an air-core inductor over wide frequency range with both single-layer and double-layer windings was shown. Then an equivalent circuit was proposed to model a transformer over this frequency range. The comparison between the measured …

Modeling And Simulation Of A Process For Upcycling Of Low-Density Polyethylene Plastic Waste To Ethylene, Xiaoyan Wang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ethylene is one of the most widely produced petrochemicals, with an estimated global output of 180 million metric tons in 2022. Approximately 82 million metric tons of ethylene are used annually for plastic production, primarily for polyethylene (PE), as well as polypropylene (PP) and polyvinyl chloride (PVC). The CO₂ emissions associated with PE production were approximately 14 million metric tons in 2022. Globally, an estimated 70 million metric tons of PE are produced and consumed each year, with the majority (~79%) ending up in landfills or the environment.

This project proposes a novel process in which waste low-density polyethylene (LDPE) …

Computational Modeling Of The Heat Treatment Of White Oak Bound For Spirit Maturation, Kate E. Mclarney-Popham

Theses and Dissertations--Chemical and Materials Engineering

Maturation of distilled spirits in white oak barrels is a long standing practice known to have great impact on spirit character. Much of this impact can be controlled by the thermal modification of the barrel, since thermal degradation of the wood determines what wood compounds are available to interact with the spirit during maturation. In this work, a computational model for the thermal degradation of wood was developed and, with flavor compound data from literature, was used to investigate the effect of heat treatment on lignin-derived flavor compounds. The computational model in this work accounted for three solid species, three …

Differential Via Modeling Using Multilayer Perceptron-Sequential (Mlp-Seq) Neural Network, Hyunwook Park, Shruti Sawant, Bandi Sathvika, Arun Chada, Soumya Singh, Seema Pk, Taein Shin, Haeseok Suh, Junyong Park, Bhyrav Mutnury, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an encoder-decoder structured multi-layer perceptron-sequential (MLP-SEQ) networks are proposed to model high-speed differential vias for estimating differential insertion loss (IL) and return loss (RL). Sequential neural networks including recurrent neural network (RNN), long short-term memory (LSTM), and gated recurrent unit (GRU) are introduced as the decoder NN to treat frequency responses as sequences. The proposed models are validated by finite element method (FEM) simulation results. The accuracy and training times of MLP-RNN, MLP-LSTM, and MLP-GRU models are compared and analyzed. Based on the MLP-LSTM model, various design of experiments (DoEs) are conducted to enhance the reproducibility and …

Integrating Risk And Vulnerability: Exploring A Unified Model For Supply Chain Resiliency, William G. Cook

USF Tampa Graduate Theses and Dissertations

The world has entered an era of retreating globalization, mounting geo-political tensions, rising protectionism, and increasing focus on the fragility of complex supply chains. The negative impacts of supply chain disruptions have been increasingly documented since the turn of the century. Given the global scale of recent disruptions, supply chain resiliency has become a national imperative. The Global Financial Crisis, the Covid-19 pandemic, and other major disruptive events demonstrate the active role of government in mitigating damage, the enduring effects of regulation, and the resultant re-evaluation of supply chain strategies by the private and public sectors. In this environment, supply …

Development Of A Mathematical Model For An Intelligent Process Control System In Brewing Industry, A.N. Yusupbekov, M.Sh. Yusupov

Chemical Technology, Control and Management

The paper deals with developing a mathematical model for a system of intelligent process control in brewing, focusing on the critical parameters of fermentation: temperature, pressure, and pH level. Mathematical models of the dynamics of the process of each of the parameters are given based on exponential dependencies, which allow for the description of the change of these values over time. The possibility of using PID regulators, neural networks, and fuzzy logic to control the process under study and the modeling that allows the optimization of beer production, improving its quality and reducing costs.

Performance Enhancement Of Vanadium Redox Flow Battery With Novel Streamlined Design: Simulation And Experimental Validation, Abdulmonem Fetyan, Bronston P. Benetho, Tawaddod Alkindi, Anugrah Andisetiawan, Musbaudeen O. Bamgbopa, Ayoob Alhammadi, Gumaa A. El-Nagar

All Works

Electrolyte utilization and the consequent concentration polarization significantly limit the potential increase in power density and contribute to electrode degradation in vanadium redox flow batteries during cycling. This study investigates a novel curvature streamlined design, drawing inspiration from natural forms, aiming to enhance the performance of vanadium redox flow battery cells compared to conventional square and rectangular flow-through cell designs. The simulated 3D single-cell model shows a notably superior uniformity in both current and species' concentration distribution within the streamlined design compared to the square and rectangular shapes. Experimental analysis conducted on 3D-printed flow frames demonstrated 2 % enhanced energy …

Study Of The Application Of Blender For Simulation Of A Closed-Loop Image-Based Greenhouse Supplemental Lighting Control, Kip Nieman, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Image-based control and sensing has been applied in a wide variety of next generation manufacturing fields. Utilizing methods of simulating closed-loop image-based control may be advantageous for improving control performance and design without the need for an experimental setup. One software capable of these simulations is the open-source 3D modeling software Blender, which has many capabilities aided by a Python API. This work explores the use of Blender as an image-based control test bed, where both the process and the controller are simulated, in the context of a greenhouse supplemental lighting control system.

Investigation Of Distributed Additive Manufacturing For 3d Printed Headband Component During Global Supply Chain Disruptions, Elizabeth M. Mamros, Saketh Kantipudi, Matthew C. Eaton, Jinjin Ha, Brad L. Kinsey

Faculty Conference Papers and Presentations

During the COVID-19 global pandemic, a shortage of personal protective equipment (PPE) occurred. Manufacturers of these critical products were unable to keep up with the growing demands as the situation evolved. Most face shields, a common type of PPE, include a headband component to provide the appropriate fit for the user and curvature for the clear face shield attachment. To mitigate this shortage in the local region, the Portsmouth Naval Shipyard (PNSY) generated a computeraided design (CAD) file for the headband component and asked the University of New Hampshire (UNH) to manufacture it with all available 3D printers, including printers …

Experimental And Computational Understanding Of Solid Oxide Iron Air Battery Performance, Chaitali Morey

Theses and Dissertations

Long-duration energy storage (LDES) (10+ hours) is considered a key technical solution for a widespread penetration of renewable energy into the utility market. However, the currently available storage technologies are limited to less than 10 hours for cost reasons. The benchmark Li-ion battery technology would be economically prohibitive if the storage time goes beyond 4 hours. Therefore, developing new low-cost LDES-compatible battery technologies is highly desirable. A solid oxide iron air battery (SOIAB) has been developed which consists of a reversible solid oxide cell (RSOC) and energy storage unit (ESU) of an iron bed. This battery is considered a promising …

Computational Fluid Dynamics Modeling Of 12.25” Horizontal Wellbores To Identify The Effects Of Pipe Rotation On Cuttings Transport Efficiency, David Rathgeber

Graduate Theses & Non-Theses

As global demand for oil and gas continues to rise alongside pressures to curb climate change, Exploration and Production (E&P) companies look to reduce their surface footprint and increase drilling efficiency through longer horizontal well drilling. In addition, the depletion of conventional reservoirs is causing E&P companies to target more difficult reservoirs, often miles offshore (Gupta et al., 2014; Meader et al., 2000a). The increased horizontal reach of these wells often leads to increased challenges in adequate hole cleaning during drilling operations. Efficient hole cleaning becomes a greater challenge in high-angle wells, with gravitational forces causing pipe eccentricity, flow channeling, …

Synthesis Of An Adaptive Neuro-Fuzzy Control System For Steam Generator Temperature, Isomiddin Xakimovich Siddikov, Dilnoza Maxamadjanovna Umurzakova

Chemical Technology, Control and Management

This paper is devoted to the modeling and synthesis of an adaptive neuro-fuzzy control system for steam generator temperature. Temperature control systems play an important role in industry because accurate and stable control is a prerequisite for the efficient operation of steam systems. Traditional control methods based on mathematical models and fixed parameter controllers may have limitations in providing optimal performance and adapting to changing operating conditions. The paper proposes a synthesized system combining fuzzy logic and adaptation methods to achieve more accurate and stable temperature control. A detailed structural diagram of the system, modeling, and tuning methods are presented. …

Harmonic Flow Modeling And Analysis Of A Green Hybrid Ac/Dc Seaport Power System, Krishan Kaushal Ram, Taufik, Helen Yu, Siddharth Vyas

Master's Theses

This thesis aims to design and develop a model for a proposed Green Seaport power system and perform harmonic analysis. The model was developed using MATLAB Simulink and tests were performed by dividing the system into several Battery Energy Storage System (BESS) operating modes such as simultaneous charging and discharging, simultaneous charging, and simultaneous discharging. For each mode, BESS state of charge and other factors such as solar irradiance for the PV system, load levels and power factor were varied to observe the impact on system’s voltage Total Harmonic Distortion (THD) level and current Total Demand Distortion (TDD). 62 separate …

Modeling The Effectiveness Of Bioremediation On Methyl Tertiary-Butyl Ether In Groundwater, Logan Bundy

Master's Theses

Methyl tertiary-butyl ether (MTBE) and its degraded form tertiary-butyl alcohol (TBA) are both known carcinogens that have contaminated groundwater aquifers across the United States. MTBE is a synthesized compound, once widely used as an additive in gasoline to increase oxygenation. Because of its popularity, MTBE was released into the environment primarily through fuel combustion and leaking underground storage tanks. These two compounds are known to be recalcitrant to most conventional physico-chemical treatment methods. Previous studies have suggested that bioremediation is effective at degrading MTBE and TBA in contaminated groundwater. Bioremediation involves the injection of oxygen, nutrients, and pre-adapted bacterial cultures …

Multi-Physics-Based Modeling Of Cracks In Asphalt Concrete, Md Amanul Hasan

Civil Engineering ETDs

Cracking is the most prevalent distress in an asphalt concrete (AC) pavement, and it leads to structural deterioration and premature failure, thereby costing taxpayers a lot of dollars. Accurately assessing AC's cracking performance is necessary for pavement longevity, yet current methods often fall short. For instance, relying solely on binder creep tests to determine low-temperature grade inadequately predicts the AC pavement's low-temperature cracking problem. Understanding AC's loading rate- and temperature-dependent fracture behavior is crucial for gaining insight into the crack propagation in AC. In the first part of this study, a new physics-based analytical methodology is developed utilizing the bending …

Simulating Information And Communication Applications In Employee Interaction Network Models, Matthew Kanter

Departmental Honors & Graduate Capstone Projects

Information and communication technology (ICT) use has been identified throughout its development and evolution with the Internet boom as a net positive tool for most employees and organizations in the working world. Only recently have studies regarding employees’ well-being begun to come to the forefront of research regarding these rapidly evolving technologies, however these are important issues to discuss in the context of work-life boundary management, emotional exhaustion, overwhelming stress levels, and moral disengagement among other employee well-being dimensions. To explore how employees’ well being might be influenced by ICT use, this study conducted a quantitative survey and analyzed a …

Modeling Of Multi-Period Disaster Logistics Planning In The State Of South Carolina, Emma Simon

All Theses

South Carolina is one of the most vulnerable states in the United States to the impact of hurricanes. Currently, when threatened with a natural disaster such as a hurricane, the state government makes many vital decisions based on knowledge and experience. In this study, the distribution of disaster relief commodities to meet immediate needs is analyzed through two models for the case of South Carolina to generate an optimal logistics strategy that considers the social vulnerability of affected populations. The first model is a multi-objective pre-disaster logistics model that uses a four-index formulation for the multiple trip vehicle routing problem. …

Predicting The Response Of An Underactuated, 3d Printed Prosthetic Hand, Lucas Gallup

UNLV Theses, Dissertations, Professional Papers, and Capstones

The continuing need for hand prostheses has led to incredible developments in this area. However, due to the cost of the most sophisticated models, it is vital to develop simpler, low-cost, underactuated prostheses that can be produced rapidly. 3D printing is an important tool to achieve this goal. In particular, the 3D printed Flexy-Hand 2 has been one of the most common low-cost designs. A key feature of the Flexy-Hand 2 is its use of tendons and thermoplastic polyurethane (TPU) for joints that are strong and flexible. TPUs, however, lack a thorough understanding of their mechanical behavior, which makes it …

Multi-Scale Modeling Of Selective Laser Sintering: From Manufacturing Process And Microstructure To Mechanical Performance In Semi-Crystalline Thermoplastics, Cameron Zadeh

All Dissertations

Selective laser sintering is an additive manufacturing process that opens many design possibilities but is limited in its reliability and reproducibility. Numerical simulations validated by experimental data yield insights into the process and resulting part properties, allowing users to make more informed decisions. In this dissertation, a model for the process and microstructure is developed and validated, followed by a coupling to mechanical models to predict part performance. Further developments include a new addition of a reaction kinetics model to the process model to describe the interplay between thermal degradation and melt pool properties, and an exploration of the parameter …

Investigating Endothelial Damage During Ischemic Stroke Treatment Using In Vitro And Computational Models, Zackary Lorton

Theses and Dissertations

Large vessel occlusion during acute ischemic strokes requires mechanical thrombectomy (MT) procedures using stent retrievers (SR). However, complete clot removal typically takes several attempts, which can amplify endothelial cell injury (EI). This project aims to characterize the extent of EI during MT using an in vitro vascular platform and a finite-element model (FEM). Impact of SR diameter and characterization of SR mechanical forces are assessed and correlated with human umbilical vein endothelial cell (HUVEC) response. HUVECs were seeded on fibronectin (4 µg/cm²) coated true-scale PDMS arterial phantoms with 2.5 mm luminal diameter. Test groups (n=6) either …

Study Of Reactive Distillation Equipment For Eterification Process, Abbos Elmanov, Abdulaziz Bakhtiyorov, Adham Norkobilov, Olimjon Maksudov, Zarif Oripov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this work is to study the chemical technological processes for eterification processes, and the reactive distillation unit, which carries out the reaction and separation process in one device, was chosen as the object of research. А reаctive distillаtion system is exаmined to produce for the production of Ethyl Acetate (EtAc) viа eterificаtion of acetic acid (HAc) with ethаnol. Optimizаtion methods using sensitivity analysis аre аlso conducted. Cаlculаtion of vаpor liquid equilibrium of the mixture system is done using UNIFАC model. Heat integration from the distillate stream of the column to the acid feed stream and from bottom …

Application Of High-Deflection Strain Gauges To Characterize Spinal-Motion Phenotypes Among Patients With Clbp, Spencer Alan Baker

Theses and Dissertations

Chronic low back pain (CLBP) is a nonspecific and persistent ailment that entails many physiological, psychological, social, and economic consequences for individuals and societies. Although there is a plethora of treatments available to treat CLBP, each treatment has varying efficacy for different patients, and it is currently unknown how to best link patients to their ideal treatment. However, it is known that biopsychosocial influences associated with CLBP affect the way that we move. It has been hypothesized that identifying phenotypes of spinal motion could facilitate an objective and repeatable method of determining the optimal treatment for each patient. The objective …

Time-Dependent Strain-Resistance Relationships In Silicone Nanocomposite Sensors, Alex Mikal Wonnacott

Theses and Dissertations

Flexible high-deflection strain gauges have been demonstrated as cost-effective and accessible sensors for capturing human biomechanical deformations. However, the interpretation of these sensors is notably more complex compared to conventional strain gauges, partially owing to the viscoelastic nature of the strain gauges. On top of the non-linear viscoelastic behavior, dynamic resistance response is even more difficult to capture due to spikes in resistance during strain changes. This research examines the relationships between stress, strain, and resistance in nanocomposite sensors during dynamic strain situations. Under the assumption that both macroscopic stress and resistance are governed by microscopic stress concentrations at the …