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University of Arkansas, Fayetteville

Theses/Dissertations

2021

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Full-Text Articles in Engineering

Data Forgery Detection In Automatic Generation Control: Exploration Of Automated Parameter Generation And Low-Rate Attacks, Yatish R. Dubasi May 2021

Data Forgery Detection In Automatic Generation Control: Exploration Of Automated Parameter Generation And Low-Rate Attacks, Yatish R. Dubasi

Computer Science and Computer Engineering Undergraduate Honors Theses

Automatic Generation Control (AGC) is a key control system utilized in electric power systems. AGC uses frequency and tie-line power flow measurements to determine the Area Control Error (ACE). ACE is then used by the AGC to adjust power generation and maintain an acceptable power system frequency. Attackers might inject false frequency and/or tie-line power flow measurements to mislead AGC into falsely adjusting power generation, which can harm power system operations. Various data forgery detection models are studied in this thesis. First, to make the use of predictive detection models easier for users, we propose a method for automated generation …


Biopolymeric Materials For Tissue Regeneration, Cell Manufacturing, And Drug Delivery, David Alfonso Castilla-Casadiego May 2021

Biopolymeric Materials For Tissue Regeneration, Cell Manufacturing, And Drug Delivery, David Alfonso Castilla-Casadiego

Graduate Theses and Dissertations

The development of materials for tissue regeneration, cell manufacturing, and drug delivery is possible by the manipulation of polymer properties and the use of three different techniques including layer-by-layer, electrospinning, and molding technique.

By applying the layer-by-layer technique over biomaterials, it is possible to develop polymeric multilayers that promote a more favorable environment for cellular functionality, increasing the possibility of improving their acceptance in the area of implantation. IRVASE demonstrated being a powerful technique that allows for a reliable characterization of the physical-chemical and thermal properties of the fabricated surfaces. This opens the possibility to monitor the design of surfaces …


Memory Module Design For High-Temperature Applications In Sic Cmos Technology, Affan Abbasi May 2021

Memory Module Design For High-Temperature Applications In Sic Cmos Technology, Affan Abbasi

Graduate Theses and Dissertations

The wide bandgap (WBG) characteristics of SiC play a significant and disruptive role in the power electronics industry. The same characteristics make this material a viable choice for high-temperature electronics systems. Leveraging the high-temperature capability of SiC is crucial to automotive, space exploration, aerospace, deep well drilling, and gas turbines. A significant issue with the high-temperature operation is the exponential increase in leakage current. The lower intrinsic carrier concentration of SiC (10-9 cm-3) compared to Si (1010 cm-3) leads to lower leakage over temperature. Several researchers have demonstrated analog and digital circuits designed in SiC. However, a memory module is …


Peptoid-Based Microsphere Coatings For Biomaterial Applications, Jesse Leland Roberts May 2021

Peptoid-Based Microsphere Coatings For Biomaterial Applications, Jesse Leland Roberts

Graduate Theses and Dissertations

Peptoids are peptidomimetic oligomers that predominantly harness similarities to peptides for biomimetic functionality. The incorporation of chiral, aromatic side chains in the peptoid sequence allows for the formation of distinct secondary structures and self-assembly into supramolecular assemblies, including microspheres. Peptoid microspheres can be coated onto substrates for potential use in biosensor technologies, tissue engineering platforms, and drug-delivery systems. They have the potential for use in biomedical applications due to their resistance to proteolytic degradation and low immunogenicity. This dissertation focuses on the physical characteristics and robustness of the peptoid microsphere coatings in various physiological conditions, along with their ability to …


Analysis Of Photodetector Based On Zinc Oxide And Cesium Lead Bromide Heterostructure With Interdigital Metallization, Tanveer Ahmed Siddique May 2021

Analysis Of Photodetector Based On Zinc Oxide And Cesium Lead Bromide Heterostructure With Interdigital Metallization, Tanveer Ahmed Siddique

Graduate Theses and Dissertations

In this thesis, photodetector based on the zinc oxide and cesium lead bromide hetero structure were fabricated and characterized. Zinc oxide (ZnO) nanoparticles were synthesized using solution processing and cesium lead bromide (CsPbBr3) thin film was synthesized using two step deposition method. Three phonon modes were obtained by the Raman spectroscopy of ZnO nanoparticles. X-ray diffraction spectra of ZnO exhibits five exciton peaks which denotes that the synthesized ZnO structure was of good crystallinity with wurtzite hexagonal phase. The absorbance spectrum of ZnO shows the bandgap (Eg) in the order of 3.5 eV that aligns with reported results. The photoluminescence …


Locating Drone Battery Supply Stations To Facilitate The Delivery Of Medical Supplies In Low And Middle-Income Countries, Madeline Suellentrop May 2021

Locating Drone Battery Supply Stations To Facilitate The Delivery Of Medical Supplies In Low And Middle-Income Countries, Madeline Suellentrop

Industrial Engineering Undergraduate Honors Theses

In the sub-Saharan region of Africa, the inability to perform emergency blood transfusions due to an inadequate blood supply has led to high fatality rates, especially among women and children. The prevalence of disease in this region limits the supply of local blood donations and, if blood is imported, then the region’s poor infrastructure inhibits fast distribution. There is a need for a technological update in the current process that overcomes the limitations of regional transportation, and drones present one promising solution for delivering small, lightweight items such as blood units. The current focus of this new delivery method is …


Decision Making Within An Nfl Context Using Multiple Objective Decision Analysis, Lawson Porter May 2021

Decision Making Within An Nfl Context Using Multiple Objective Decision Analysis, Lawson Porter

Industrial Engineering Undergraduate Honors Theses

The National Football League (NFL) is the most popular sports league in the world, with millions of viewers every game and billions of dollars generated every season. Statistics are an important part of an NFL team’s business operating model and contribute greatly towards their decision making. Every season, general managers try to sign players that give the team the highest probability of winning games throughout the year. There are many factors that go into this decision, including the amount of money the team has to spend and the value that available players can bring to a team. Teams must abide …


Quantifying The Benefits Of A Collaborative Supply Chain Network Using A Discrete-Time Vehicle Routing Model, Matthew Walters May 2021

Quantifying The Benefits Of A Collaborative Supply Chain Network Using A Discrete-Time Vehicle Routing Model, Matthew Walters

Industrial Engineering Undergraduate Honors Theses

The transportation industry contributed around one trillion dollars to the economy in 2016 accounting for 8.9% percent of the GDP. In 2017, it was responsible for 1.5 billion tons of CO2 emissions. With the American Trucking agency predicting a 35% growth in the trucking industry between 2016 and 2027, there are rising concerns about the impact the trucking industry will have on the economy and the environment. The trucking industry is also very inefficient with many trucks driving with empty loads or with less than full capacity loads. There is potential to save billions of dollars and cut back …


Static Force Analysis Of A Porcine Mitral Valve To Determine Self-Supporting Capabilities Of The Leaflets, Jacob Paris May 2021

Static Force Analysis Of A Porcine Mitral Valve To Determine Self-Supporting Capabilities Of The Leaflets, Jacob Paris

Biomedical Engineering Undergraduate Honors Theses

The mitral valve (MV) is responsible for controlling the flow between the left atrium (LA) and left ventricle (LV). This includes maintaining valve closure under high systolic pressures. Mitral regurgitation (MR) occurs when the valve fails to completely close and blood flows in the reverse direction, from the LV to the LA, during ejection. This type of valvular heart disease is prevalent among elderly individuals and is becoming increasingly common as the population ages. In order to better understand how to properly treat this large group of affected individuals, the mechanics of the MV during high systolic pressures must be …


Characterizing High Entropy Alloys For Hypersonic Applications, Katherine Pettus May 2021

Characterizing High Entropy Alloys For Hypersonic Applications, Katherine Pettus

Mechanical Engineering Undergraduate Honors Theses

In this paper, the properties of a new and broad class of materials, high entropy alloys (HEAs), were investigated and evaluated for hypersonic applications. The plan was to identify candidate hypersonic HEAs and model the high-temperature strength using new advanced material models that account for asymmetry and anisotropy characterized with available test data. After accessing a local database of HEAs and their material properties in collaboration with Dr. Gorsse et al., it was realized the knowledge of HEAs is currently very broad but lacks depth. While hundreds of HEAs have been created and tested, none so far have both sufficient …


Noise Control In Sorting Conveyors, Eyra Herrera May 2021

Noise Control In Sorting Conveyors, Eyra Herrera

Mechanical Engineering Undergraduate Honors Theses

E-commerce has increased the necessity of effective material handling equipment in warehouses and distribution centers. Sorter conveyors systems facilitate material handling by providing a reliable and automated system to classify and distribute products in a gentle and rapid manner. With the steady increase of speed in sorter conveyors to satisfy today’s industry demand, some systems have started to produce high noise levels that could potentially affect workers’ health. Since decreasing the speed of these conveyors is not a viable option to decrease noise in sorter equipment, industries have opted to find other ways to apply noise control to their equipment. …


Quantum Dynamical Phenomena In Non-Hermitian And Magnomechanical Systems, Saeid Vashahri Ghamsari May 2021

Quantum Dynamical Phenomena In Non-Hermitian And Magnomechanical Systems, Saeid Vashahri Ghamsari

Graduate Theses and Dissertations

In this dissertation, we have investigated quantum dynamics via three case studies. First, we studied a system of two coupled waveguides respectively carrying optical damping and optical gain in addition to squeezing elements in one or both waveguides. Such a system is expected to generate highly entangled light fields in the two waveguides. We, however, show that the degree of the created entanglement is significantly affected by the quantum noises associated with the amplification and dissipation. Because of the noise effect, one can only have nonzero entanglement for a limited time interval. Second, we generalized the first project by considering …


Statistical Machine Learning For Breast Cancer Detection With Terahertz Imaging, Tanny Andrea Chavez Esparza May 2021

Statistical Machine Learning For Breast Cancer Detection With Terahertz Imaging, Tanny Andrea Chavez Esparza

Graduate Theses and Dissertations

Breast conserving surgery (BCS) is a common breast cancer treatment option, in which the cancerous tissue is excised while leaving most of the healthy breast tissue intact. The lack of in-situ margin evaluation unfortunately results in a re-excision rate of 20-30% for this type of procedure. This study aims to design statistical and machine learning segmentation algorithms for the detection of breast cancer in BCS by using terahertz (THz) imaging. Given the material characterization properties of the non-ionizing radiation in the THz range, we intend to employ the responses from the THz system to identify healthy and cancerous breast tissue …


Oxone® Mediated Tempo-Oxidized Cellulose Nanomaterials: Material Characterization, Ultrafiltration Membrane Separations, And Thin Film Composite Gas Transport Analysis, John Phillips Moore May 2021

Oxone® Mediated Tempo-Oxidized Cellulose Nanomaterials: Material Characterization, Ultrafiltration Membrane Separations, And Thin Film Composite Gas Transport Analysis, John Phillips Moore

Graduate Theses and Dissertations

Cellulose nanomaterials (CNMs) are derived from plant matter and are comprised of nanoscopic cellulose crystals and fibers. They have a diverse set of applications, from cosmetics to oil recovery. This study focuses on the properties of Oxone® mediated TEMPO-oxidized cellulose nanomaterials (OTO-CNMs) and their use in controlling the transport properties of polymeric substrates. Synthesis and characterization of cellulosic nanoparticles have resulted in the creation of OTO-CNMs with properties that increase hydrophilicity. With added hydrophilicity, OTO-CNMs possess lower fouling propensity, making them ideal membrane additive for transport limited separations such as hemodialysis.

To utilize the material and unique properties thereof, this …


Improvement Of Stability Of A Grid-Connected Inverter With An Lcl Filter By Robust Strong Active Damping And Model Predictive Control, Seungyong Lee May 2021

Improvement Of Stability Of A Grid-Connected Inverter With An Lcl Filter By Robust Strong Active Damping And Model Predictive Control, Seungyong Lee

Graduate Theses and Dissertations

This study addresses development and implementation of robust control methods for a three-phase grid-connected voltage source inverter (VSI) accompanied by an inductive-capacitive-inductive (LCL) filter. A challenge of current control for the VSI is LCL filter resonance near to the control stability boundary, which interacts with the inverter control switching actions and creates the possibility of instability. In general, active damping is needed to stabilize the system and ensure robust performance in steady-state and dynamic responses. While many active damping methods have been proposed to resolve this issue, capacitor-current-feedback active damping has been most widely used for its simple implementation.

There …


An Accurate And Efficient Electro-Thermal Compact Model Of Sic Power Mosfet Including Third Quadrant Behavior, Arman Ur Rashid May 2021

An Accurate And Efficient Electro-Thermal Compact Model Of Sic Power Mosfet Including Third Quadrant Behavior, Arman Ur Rashid

Graduate Theses and Dissertations

Due to narrower bandgap and lower critical electric field, silicon (Si) power devices have reached their limit in terms of the maximum blocking voltage capability. Exploiting this limitation, wide bandgap devices, namely silicon carbide (SiC) and gallium nitride (GaN) devices, are increasingly encroaching on the lucrative power electronics market. Unlike GaN, SiC devices can exploit most of the established fabrication techniques of Si power devices. Having substrate of the same material, vertical device structures with higher breakdown capabilities are feasible in SiC, unlike their GaN counterpart. Also, the excellent thermal conductivity of SiC, compared to GaN and Si, let SiC …


Scheduling Allocation And Inventory Replenishment Problems Under Uncertainty: Applications In Managing Electric Vehicle And Drone Battery Swap Stations, Amin Asadi Jan 2021

Scheduling Allocation And Inventory Replenishment Problems Under Uncertainty: Applications In Managing Electric Vehicle And Drone Battery Swap Stations, Amin Asadi

Graduate Theses and Dissertations

In this dissertation, motivated by electric vehicle (EV) and drone application growth, we propose novel optimization problems and solution techniques for managing the operations at EV and drone battery swap stations. In Chapter 2, we introduce a novel class of stochastic scheduling allocation and inventory replenishment problems (SAIRP), which determines the recharging, discharging, and replacement decisions at a swap station over time to maximize the expected total profit. We use Markov Decision Process (MDP) to model SAIRPs facing uncertain demands, varying costs, and battery degradation. Considering battery degradation is crucial as it relaxes the assumption that charging/discharging batteries do not …


Development Of A Reference Design For Intrusion Detection Using Neural Networks For A Smart Inverter, Ammar Mohammad Khan Jan 2021

Development Of A Reference Design For Intrusion Detection Using Neural Networks For A Smart Inverter, Ammar Mohammad Khan

Graduate Theses and Dissertations

The purpose of this thesis is to develop a reference design for a base level implementation of an intrusion detection module using artificial neural networks that is deployed onto an inverter and runs on live data for cybersecurity purposes, leveraging the latest deep learning algorithms and tools. Cybersecurity in the smart grid industry focuses on maintaining optimal standards of security in the system and a key component of this is being able to detect cyberattacks. Although researchers and engineers aim to design such devices with embedded security, attacks can and do still occur. The foundation for eventually mitigating these attacks …


Investigation Of Iron-Nickel Based Nanoparticles As Catalysts For Oxygen Evolution Reaction (Oer), Prashant Acharya Jan 2021

Investigation Of Iron-Nickel Based Nanoparticles As Catalysts For Oxygen Evolution Reaction (Oer), Prashant Acharya

Graduate Theses and Dissertations

Hydrogen fuel is increasingly seen as an appealing alternative by both the scientific and the industrial communities in the drive towards a clean energy future. Hydrogen, unlike fossil-based fuels, does not release carbon dioxide, a chief component of greenhouse gases, upon combustion. However, more than 95% of the hydrogen in the world is still produced by burning fossil fuels as this method is currently the only economically feasible option at a large industrial scale.

Water electrolysis shows a lot of potential in both hydrogen generation and in the storage of energy from renewable sources such as wind and sunlight. Likewise, …