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

Engineering Commons™

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

University of Arkansas, Fayetteville

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 601 - 630 of 2841

Full-Text Articles in Engineering

Bio-Methane Production From Anaerobic Co-Digestion Of Poultry Litter With Wheat Straw Improved By Process Optimization And Employment Of Advanced Techniques, Yuanhang Zhan Aug 2023

Bio-Methane Production From Anaerobic Co-Digestion Of Poultry Litter With Wheat Straw Improved By Process Optimization And Employment Of Advanced Techniques, Yuanhang Zhan

Graduate Theses and Dissertations

Anaerobic co-digestion (Co-AD) of poultry litter (PL) and wheat straw (WS) for sustainable waste management and simultaneously renewable bioenergy generation was improved by advanced technologies including micro-aeration (MA), biochar addition (BC), nanoparticles supplementation (NP) and their integrations. Response surface methodology (RSM) and artificial neural network (ANN) were used for the process modeling and optimization. First, a method by gradually increasing OLR was developed for the start-up of Co-AD of PL and WS in an anaerobic sequencing batch reactor (ASBR), with a continuous daily biogas production of (13.06 ± 0.21) L and methane content (MC) of (54.38 ± 0.53) % observed. …

Go to article

Achieving High Renewable Energy Integration In Smart Grids With Machine Learning, Yaze Li Aug 2023

Achieving High Renewable Energy Integration In Smart Grids With Machine Learning, Yaze Li

Graduate Theses and Dissertations

The integration of high levels of renewable energy into smart grids is crucial for achieving a sustainable and efficient energy infrastructure. However, this integration presents significant technical and operational challenges due to the intermittent nature and inherent uncertainty of renewable energy sources (RES). Therefore, the energy storage system (ESS) has always been bound to renewable energy, and its charge and discharge control has become an important part of the integration. The addition of RES and ESS comes with their complex control, communication, and monitor capabilities, which also makes the grid more vulnerable to attacks, brings new challenges to the cybersecurity. …

Go to article

Double-Sided Cooled Power Modules For Electric Vehicles, Riya Paul Aug 2023

Double-Sided Cooled Power Modules For Electric Vehicles, Riya Paul

Graduate Theses and Dissertations

Double-sided cooled (DSC) power modules in conjunction with Silicon Carbide (SiC) power devices are expected to significantly elevate the performance of the next-generation electric vehicle power inverters. The double-sided cooling enables maximum heat dissipation, resulting in higher power density. SiC power devices, with their fast-switching speeds, reduce the power losses for higher efficiency. A half-bridge power module consisting of 13 mΩ 1.2 kV SiC devices is used for this work. A baseline DSC power module was designed, fabricated, and tested. This unique design uses truncated rectangular copper connection blocks for better heat dissipation from the device top side compared to …

Go to article

Partial Discharge Mitigation In Power Modules Using An Automation-Driven Design Rule Development Method, Shilpi Mukherjee Aug 2023

Partial Discharge Mitigation In Power Modules Using An Automation-Driven Design Rule Development Method, Shilpi Mukherjee

Graduate Theses and Dissertations

Power modules used for the conversion and conditioning of electrical power for applications like electric vehicles, more-electric aircraft, the power grid, etc., are largely designed manually by engineers. Design automation of power modules is starting to gain recognition as a timely and necessary alternative to intuitive manual design and fabrication. With increasing need for wide bandgap materials that can operate at higher voltages, and the need to make modules more compact, hazards like electrical breakdown are more likely. Partial discharge (PD) is a silent and invisible precursor to electrical breakdown. It is compounded with compaction, creating a potential for electrical …

Go to article

A Real-Time Anpc Inverter Digital Twin With Integrated Design-For-Trust, Paulo Vitor Do Amaral Custodio Aug 2023

A Real-Time Anpc Inverter Digital Twin With Integrated Design-For-Trust, Paulo Vitor Do Amaral Custodio

Graduate Theses and Dissertations

The demand for renewable energy has increased over the last few years, and so has the demand for greater expectations within the energy market. This increasing trend has been accompanied by more significant usage of internet-connected devices (IoT), leading to critical electrical infrastructure being connected to the internet. Implementing internet connectivity with such devices and systems provides benefits such as improving the system's performance, facilitating irregularity and anomaly mitigation, and providing additional situational awareness for enhanced decision-making. However, enhancing the connected system with IoT introduces a drawback – a greater vulnerability to cyber-attacks. Cyber-attacks targeting critical infrastructure in the electrical …

Go to article

Modeling & Small Signal Analysis Of Grid Forming Inverter, Kadesh Hepburn Aug 2023

Modeling & Small Signal Analysis Of Grid Forming Inverter, Kadesh Hepburn

Graduate Theses and Dissertations

There is a rising number of inverter-based resources (IBRs) being integrated with distribution systems are becoming a more common occurrence. With integration of IBRs inverters, power utilities are experiencing an increase of number of operations with regards to voltage and frequency support. To maintain grid stability and reliability, IBRs need to provide some of the services currently (or formerly) provided by synchronous generators. Interconnection standards, like the IEEE 1547. 2018 has include requirements for IBRs to have the capability to provide some of these services—such as frequency and voltage support—and the procurement and deployment of the services can be implemented …

Go to article

Optocoupler Integration Of Ltcc-Based Gate Driver In A Sic Power Module, Michael Oghenekome Otobo Aug 2023

Optocoupler Integration Of Ltcc-Based Gate Driver In A Sic Power Module, Michael Oghenekome Otobo

Graduate Theses and Dissertations

The growing demand for electrical energy in today’s industrialized economy has driven the need for innovative approaches to meet diverse application requirements. Notably, advancements have been made in the field of power electronic systems, as reliable power electronic converters are essential for managing multiple power sources and loads. However, the development of these systems poses challenges related to power device switching speed, system weight and size, and power losses. The integration of a gate driver into a SiC power module offers a solution to many of these challenges, thereby driving the advancement of electrical power density expansion. An LTCC-based gate …

Go to article

Liquid Crystalline Coacervates Composed Of Chromonic Mesogens And Polyelectrolytes, Elizabeth Adeogun Aug 2023

Liquid Crystalline Coacervates Composed Of Chromonic Mesogens And Polyelectrolytes, Elizabeth Adeogun

Graduate Theses and Dissertations

Complex coacervates are formed by liquid-liquid phase separation of an aqueous solution of oppositely charged ions. Although several mixtures of molecules of natural and synthetic macro-ion have been shown to form complex coacervates, the formation of liquid crystalline (LC) coacervates are sparsely reported. LC coacervates have a unique property in that they can change their shape and optical property in response to external stimuli such as changes in temperature, pH, or the presence of specific molecules. This property makes LC coacervates useful as a sensor, as they can be engineered to respond to specific stimuli and generate a measurable signal …

Go to article

Chip- And System-Level Reliability On Sic-Based Power Modules, Pengyu Lai Aug 2023

Chip- And System-Level Reliability On Sic-Based Power Modules, Pengyu Lai

Graduate Theses and Dissertations

The blocking voltage, switching frequency and temperature tolerance of power devices have been greatly improved due to the revolution of wide bandgap (WBG) materials, such as silicon carbide (SiC) and gallium nitride (GaN). Owing to the development of SiC-based power devices, the power rating, operating voltage, and power density of power modules have been significantly improved. However, the reliability of SiC-based power modules has not been fully explored yet. Thus, this dissertation focuses on the chip- and system-level reliability on SiC-based power modules. For chip-level reliability, this work focuses on on-chip SiC ESD protection devices for SiC-based integrated circuits (ICs). …

Go to article

Integrated And Monolithic Iii-Nitride Devices Grown By Mbe, Rohith Allaparthi Aug 2023

Integrated And Monolithic Iii-Nitride Devices Grown By Mbe, Rohith Allaparthi

Graduate Theses and Dissertations

III-Nitride (III-N) semiconductors with wide bandgap (WBG) characteristics offer promising advancements for high power density, high voltage, and high-frequency applications, presenting a promising alternative to traditional silicon (Si) technology. However, native substrate material for the majority of WBG semiconductors is still not commercially affordable. Because of its highly mature progression, utilizing standard Si wafers as substrates is a cost-effective alternative. This dissertation explores the development of electronic devices based on III-N thin films, grown monolithically via molecular beam epitaxy (MBE), followed by several processing techniques. Initially, a heterojunction p-n diode is realized, incorporating the growth of single-crystal WBG AlN films …

Go to article

Fabrication And Measurement Of Lt-Gaas Photoconductive Antennas And Arrays, Zachary Paul Uttley Aug 2023

Fabrication And Measurement Of Lt-Gaas Photoconductive Antennas And Arrays, Zachary Paul Uttley

Graduate Theses and Dissertations

This thesis presents the fabrication and measurement of LT-GaAs based terahertz (THz) photo conductive antennas (PCAs) and arrays. The LT-GaAs THz PCAs are fabricated to serve as reference devices to new 2D material black phosphorous (BP) based THz PCAs. The LT-GaAs and BP devices have identical metallic electrodes, allowing for a comparison of emitted THz intensity and bandwidth. All PCAs have been measured using an open bench pulsed time-domain spectroscopy (TDS) system with a usable bandwidth from 0.1-4 THz, pumped with a 780nm Ti:Sapphire femtosecond laser. The results have shown LT-GaAs devices outperforming BP devices in signal amplitude and bandwidth …

Go to article

Uncovering The Spatio-Temporal Impact Of The Covid-19 Pandemic On Shared E-Scooter Usage: A Spatial Panel Model, Farzana Mehzabin Tuli, Arna Nishita Nithila, Suman Mitra Jul 2023

Uncovering The Spatio-Temporal Impact Of The Covid-19 Pandemic On Shared E-Scooter Usage: A Spatial Panel Model, Farzana Mehzabin Tuli, Arna Nishita Nithila, Suman Mitra

Civil Engineering Faculty Publications and Presentations

This study examines the spatio-temporal effects of the COVID-19 pandemic on shared e-scooter usage by leveraging two years (2019 and 2020) of daily shared micromobility data from Austin, Texas. We employed a series of random effects spatial-autoregressive model with a spatially autocorrelated error (SAC) to examine the differences and similarities in determinants of e-scooter usage during regular and pandemic periods and to identify factors contributing to the changes in e-scooter use during the Pandemic. Model results provided strong evidence of spatial autocorrelation in the e-scooter trip data and found a spatial negative spillover effect in the 2020 model. The key …

Go to article

High Flux Novel Polymeric Membrane For Renal Applications, Christa N. Hestekin, Efecan Pakkaner, Jamie Hestekin, Leticia Santos De Souza, Partha Pratim Chowdhury, Juliana Louzada Marçal, John Moore, Sarah A. Hesse, Christopher J. Takacs, Christopher J. Tassone, Soma Shekar Dachavaram, Peter A. Crooks, Kate Williams, Ira Kurtz Jul 2023

High Flux Novel Polymeric Membrane For Renal Applications, Christa N. Hestekin, Efecan Pakkaner, Jamie Hestekin, Leticia Santos De Souza, Partha Pratim Chowdhury, Juliana Louzada Marçal, John Moore, Sarah A. Hesse, Christopher J. Takacs, Christopher J. Tassone, Soma Shekar Dachavaram, Peter A. Crooks, Kate Williams, Ira Kurtz

Chemical Engineering Faculty Publications and Presentations

Biocompatibility and the ability to mediate the appropriate flux of ions, urea, and uremic toxins between blood and dialysate components are key parameters for membranes used in dialysis. Oxone-mediated TEMPO-oxidized cellulose nanomaterials have been demonstrated to be excellent additives in the production and tunability of ultrafiltration and dialysis membranes. In the present study, nanocellulose ionic liquid membranes (NC-ILMs) were tested in vitro and ex vivo. An increase in flux of up to two orders of magnitude was observed with increased rejection (about 99.6%) of key proteins compared to that of polysulfone (PSf) and other commercial membranes. NC-ILMs have a sharper …

Go to article

Tribological Behavior Of Polydopamine/Polytetrafluoroethylene Coating On Laser Textured Stainless Steel With Hilbert Curves, Firuze Soltani-Kordshuli, Nathaniel Harris, Min Zou Jul 2023

Tribological Behavior Of Polydopamine/Polytetrafluoroethylene Coating On Laser Textured Stainless Steel With Hilbert Curves, Firuze Soltani-Kordshuli, Nathaniel Harris, Min Zou

Mechanical Engineering Faculty Publications and Presentations

Shallow Hilbert curve patterns with easily programmable texture density were selected for laser texturing of stainless steel substrates. Two different texture path segment lengths (12 and 24 mu m) and four different laser power percentages (5%, 10%, 15%, and 20%) were investigated. The textured and smooth substrates were coated with thin polydopamine/polytetrafluoroethylene (PDA/PTFE) coatings for tribological property assessment. The effects of texture density (texture area coverage) and laser power on the durability and friction of the coated surfaces were studied. Laser texturing the substrates improved the coating durability up to 25 times, reduced the friction coefficient, and prevented coating global …

Go to article

Co-Activation Of The Diaphragm And External Intercostal Muscles Through An Adaptive Closed-Loop Respiratory Pacing Controller, Rabeya Zinnat Adury, Ricardo Siu, Ranu Jung Jul 2023

Co-Activation Of The Diaphragm And External Intercostal Muscles Through An Adaptive Closed-Loop Respiratory Pacing Controller, Rabeya Zinnat Adury, Ricardo Siu, Ranu Jung

Biomedical Engineering Faculty Publications and Presentations

Introduction: Respiratory pacing is a promising alternative to traditional mechanical ventilation that has been shown to significantly increase the survival and quality of life after the neural control of the respiratory system has been compromised. However, current pacing approaches to achieve adequate ventilation tend to target only the diaphragm without pacing external intercostal muscles that are also activated during normal inspiration. Furthermore, the pacing paradigms do not allow for intermittent sighing, which carries an important physiological role. We hypothesized that simultaneous activation of the diaphragm and external intercostal muscles would improve the efficiency of respiratory pacing compared to diaphragm stimulation …

Go to article

Mitochondrial Transfer From Cancer-Associated Fibroblasts Increases Migration In Aggressive Breast Cancer, Kevin F. Gwolas, Sarah Libring, Emily Berestesky, Shayan Gholizadeh, Samantha C. Schwager, Andra R. Frost, Thomas R. Gaborski, Jian Zhang, Cynthia A. Reinhart-King Jul 2023

Mitochondrial Transfer From Cancer-Associated Fibroblasts Increases Migration In Aggressive Breast Cancer, Kevin F. Gwolas, Sarah Libring, Emily Berestesky, Shayan Gholizadeh, Samantha C. Schwager, Andra R. Frost, Thomas R. Gaborski, Jian Zhang, Cynthia A. Reinhart-King

Biomedical Engineering Faculty Publications and Presentations

Cancer-associated fibroblasts (CAFs) have distinct roles within the tumor microenvironment, which can impact the mode and efficacy of tumor cell migration. CAFs are known to increase invasion of less-aggressive breast cancer cells through matrix remodeling and leader–follower dynamics. Here, we demonstrate that CAFs communicate with breast cancer cells through the formation of contact-dependent tunneling nanotubes (TNTs), which allow for the exchange of cargo between cell types. CAF mitochondria are an integral cargo component and are sufficient to increase the 3D migration of cancer cells. This cargo transfer results in an increase in mitochondrial ATP production in cancer cells, whereas it …

Go to article

Freestanding Graphene Heat Engine Analyzed Using Stochastic Thermodynamics, J. Durbin, J. M. Mangum, M. N. Gikunda, F. Harerimana, P. Kumar, L. L. Bonilla, P. M. Thibado Jul 2023

Freestanding Graphene Heat Engine Analyzed Using Stochastic Thermodynamics, J. Durbin, J. M. Mangum, M. N. Gikunda, F. Harerimana, P. Kumar, L. L. Bonilla, P. M. Thibado

Physics Faculty Publications and Presentations

We present an Ito-Langevin model for freestanding graphene connected to an electrical circuit. The graphene is treated as a Brownian particle in a double-well potential and is adjacent to a fixed electrode to form a variable capacitor. The capacitor is connected in series with a battery and a load resistor. The capacitor and resistor are given separate thermal reservoirs. We have solved the coupled Ito-Langevin equations for a broad range of temperature differences between the two reservoirs. Using ensemble averages, we report the rate of change in energy, heat, and work using stochastic thermodynamics. When the resistor is held at …

Go to article

Non-Steady-State Fickian Diffusion Models Decrease The Estimated Gel Layer Diffusion Coefficient Uncertainty For Diffusive Gradients In Thin-Films Passive Samplers, Samuel D. Hodges, David G. Wahman, Levi M. Haupert, Huong T. Pham, Margaret K. Bozarth, Michael B. Howland, Julian L. Fairey Jun 2023

Non-Steady-State Fickian Diffusion Models Decrease The Estimated Gel Layer Diffusion Coefficient Uncertainty For Diffusive Gradients In Thin-Films Passive Samplers, Samuel D. Hodges, David G. Wahman, Levi M. Haupert, Huong T. Pham, Margaret K. Bozarth, Michael B. Howland, Julian L. Fairey

Civil Engineering Faculty Publications and Presentations

Mass transport in diffusive gradients in thin-film passive samplers is restricted to diffusion through a gel layer of agarose or agarose cross-linked polyacrylamide (APA). The gel layer diffusion coefficient, DGel, is typically determined using a standard analysis (SA) based on Fick’s first law from two-compartment diffusion cell (D-Cell) tests. The SA assumes pseudo-steady-state flux, characterized by linear sink mass accumulation–time profiles with a typical threshold R2 ≥ 0.97. In 72 D-Cell tests with nitrate, 63 met this threshold, but the SA-determined DGel ranged from 10.1 to 15.8 × 10–6 cm2·s–1 (agarose) and …

Go to article

Integrated Electrocoagulation, Ultrafiltration, Membrane Distillation, And Crystallization For Treating Produced Water, Mahmood Jebur, Yelyzaveta Bachynska, Xiaolei Hao, Sumith Ranil Wickramasinghe Jun 2023

Integrated Electrocoagulation, Ultrafiltration, Membrane Distillation, And Crystallization For Treating Produced Water, Mahmood Jebur, Yelyzaveta Bachynska, Xiaolei Hao, Sumith Ranil Wickramasinghe

Chemical Engineering Faculty Publications and Presentations

Produced water (PW) generated from hydraulic fracturing operations was treated using an integrated electrocoagulation, ultrafiltration, membrane distillation, and crystallization process (EC UF MDC). The aim was to determine the viability of this integrated process for maximizing water recovery. The results obtained here indicate that optimizing the various unit operations could lead to increased recovery of PW. Membrane fouling limits all membrane separation processes. A pretreatment step to suppress fouling is essential. Here, removal of total suspended solids (TSS) and total organic carbon (TOC) was achieved by electrocoagulation (EC) followed by ultrafiltration (UF). The hydrophobic membrane used in membrane distillation may …

Go to article

Clinical Utility Of Mesenchymal Stem/Stromal Cells In Regenerative Medicine And Cellular Therapy, Vitali V. Maldonado, Neel H. Patel, Emma E. Smith, C. Lowry Barnes, Michael P. Gustafson, Raj R. Rao, Rebekah M. Samsonraj Jun 2023

Clinical Utility Of Mesenchymal Stem/Stromal Cells In Regenerative Medicine And Cellular Therapy, Vitali V. Maldonado, Neel H. Patel, Emma E. Smith, C. Lowry Barnes, Michael P. Gustafson, Raj R. Rao, Rebekah M. Samsonraj

Biomedical Engineering Faculty Publications and Presentations

Mesenchymal stem/stromal cells (MSCs) have been carefully examined to have tremendous potential in regenerative medicine. With their immunomodulatory and regenerative properties, MSCs have numerous applications within the clinical sector. MSCs have the properties of multilineage differentiation, paracrine signaling, and can be isolated from various tissues, which makes them a key candidate for applications in numerous organ systems. To accentuate the importance of MSC therapy for a range of clinical indications, this review highlights MSC-specific studies on the musculoskeletal, nervous, cardiovascular, and immune systems where most trials are reported. Furthermore, an updated list of the different types of MSCs used in …

Go to article

Svar: A Virtual Machine For Portable Code On Reconfigurable Accelerators, Nathaniel Fredricks May 2023

Svar: A Virtual Machine For Portable Code On Reconfigurable Accelerators, Nathaniel Fredricks

Computer Science and Computer Engineering Undergraduate Honors Theses

The SPAR-2 array processor was designed as an overlay architecture for implementation on Xilinx Field Programmable Gate Arrays (FPGAs). As an overlay, the SPAR-2 array processor can be configured to take advantage of the specific resources available on different FPGAs. However once configured, the SPAR-2 requires programmer’s to have knowledge of the low level architecture, and write platform-specific code. In this thesis SVAR, a hardware/software co-designed virtual machine, is proposed that runs on the SPAR-2. SVAR allows programmers to write portable, platform-independent code once and have it interpreted for any specific configuration. Results are presented that verify the virtual machine …

Go to article

Smart-Insect Monitoring System Integration And Interaction Via Ai Cloud Deployment And Gpt, Ahmed Moustafa May 2023

Smart-Insect Monitoring System Integration And Interaction Via Ai Cloud Deployment And Gpt, Ahmed Moustafa

Computer Science and Computer Engineering Undergraduate Honors Theses

The Insect Detection Server was developed to explore the deployment and integration of an Artificial Intelligence model for Computer Vision in the context of insect detection. The model was developed to accurately identify insects from images taken by camera systems installed on farms. The goal is to integrate the model into an easily accessible, cloud-based application that allows farmers to analyze automatically uploaded images containing groups of insects found on their farms. The application returns the bounding boxes and the detected classes of insects whenever an image is captured on-site, enabling farmers to take appropriate actions to address the issue …

Go to article

Fabrication Of Black Phosphorus Terahertz Photoconductive Antennas, Nathan Tanner Sawyers May 2023

Fabrication Of Black Phosphorus Terahertz Photoconductive Antennas, Nathan Tanner Sawyers

Physics Undergraduate Honors Theses

Terahertz (THz) photoconductive antennas (PCAs) using 40nm thin-film flakes of black phosphorus (BP) and hexagonal boron nitride (hBN) have been shown computationally to be capable of THz emission comparable to those based on GaAs [2]. In this paper, I briefly describe the scientific and practical interest in THz emissions and explain what warrants research into black phosphorus as a photoconductive semiconductor in THz devices. Furthermore, I outline the basic principle of how these antennas work and mention alternative designs produced by other researchers in the past. Finally, I summarize the fabrication process of these antennas, as well as the measurements …

Go to article

Photocatalytic Nanoparticle Treatment Of Cyanotoxins In Harmful Algal Blooms, Brian Baird May 2023

Photocatalytic Nanoparticle Treatment Of Cyanotoxins In Harmful Algal Blooms, Brian Baird

Civil Engineering Undergraduate Honors Theses

Harmful Algal Blooms (HAB) have the ability to cause detriment to water bodies, ecosystems, and human health. Furthermore, current evidence suggests that these events are becoming increasingly common due to factors such as increased pollution and global warming. While there are current methods to treat water that is negatively impacted by the bacteria and toxins associated with HABs, these methods are often costly and inefficient. The purpose of this research is to explore a potential treatment option that uses titanium dioxide photocatalytic nanoparticles attached to a retractable net to treat toxins produced by HABs in situ. Specifically, the toxin …

Go to article

Preserving User Data Privacy Through The Development Of An Android Solid Library, Alexandria Lim May 2023

Preserving User Data Privacy Through The Development Of An Android Solid Library, Alexandria Lim

Computer Science and Computer Engineering Undergraduate Honors Theses

In today’s world where any and all activity on the internet produces data, user data privacy and autonomy are not prioritized. Companies called data brokers are able to gather data elements of personal information numbering in the billions. This data can be anything from purchase history, credit card history, downloaded applications, and service subscriptions. This information can be analyzed and inferences can be drawn from analysis, categorizing people into groups that range in sensitivity — from hobbies to race and income classes. Not only do these data brokers constantly overlook data privacy, this mass amount of data makes them extremely …

Go to article

Micro-Faraday Cage Design And Analysis For Rf Sensitive Components On An Ltcc Substrate In Hfss, Roberto Quezada May 2023

Micro-Faraday Cage Design And Analysis For Rf Sensitive Components On An Ltcc Substrate In Hfss, Roberto Quezada

Electrical Engineering Undergraduate Honors Theses

This thesis focuses on creating and testing two different simulation environments in HFSS and analyzing the effectiveness of a micro-Faraday Cage on the RF Sensitive component by exchanging the SMPS and RF Sensitive component with 25GHz Microstrip Patch Antennas. Modern integrated circuit board systems consist of components that can generate electromagnetic signals and components that may be sensitive to electromagnetic interference. A switched-mode power supply (SMPS) is one component capable of producing electromagnetic interference (EMI) through its fundamental and harmonic switching frequency. By using a Faraday Cage to shield the RF-sensitive element, it is possible to reduce its susceptibility to …

Go to article

Design Of A Sigma-Delta Adc In 65nm Cmos Process, Michael Lee Thompson Iii May 2023

Design Of A Sigma-Delta Adc In 65nm Cmos Process, Michael Lee Thompson Iii

Electrical Engineering Undergraduate Honors Theses

Analog and digital signals both play a vital role in electrical engineering and the technology of today. As the role of electrical and computer engineers becomes more deeply involved in the development of new technology, an understanding of how these signals are utilized, and what they represent, is a necessity. Due to the inherent limitations involved with analog signals, there is a need for these signals to be accurately and efficiently converted to digital signals for processing. The job of the analog-to-digital converter, or ADC, is to receive this analog input signal (voltage or current) and create a digital representation …

Go to article

Evaluation Of Dual Band J-Pole Antennas To Serve Drone-Mountable Ham Radio Repeater, Jeremiah Wimer May 2023

Evaluation Of Dual Band J-Pole Antennas To Serve Drone-Mountable Ham Radio Repeater, Jeremiah Wimer

Electrical Engineering Undergraduate Honors Theses

The portable “roll-up” Dual-Band J-pole antenna model (commonly referred to as DBJ-2) is found to be the most favorable J-pole antenna design for serving a drone-mountable ham radio repeater. In addition to being light in weight, inexpensive to construct, and weather-resilient, the DBJ-2 offers the greatest Standing Wave Ratio (SWR) in the Very High Frequency (VHF) and Ultra High Frequency (UHF) bands compared to the other J-pole antenna designs evaluated. Enclosed is a brief overview of antenna design theory, as well as an exploration of various other J-pole antenna designs, and a clear rationale for selecting the DBJ-2 antenna design …

Go to article

Reverse Engineering Post-Quantum Cryptography Schemes To Find Rowhammer Exploits, Sam Lefforge May 2023

Reverse Engineering Post-Quantum Cryptography Schemes To Find Rowhammer Exploits, Sam Lefforge

Computer Science and Computer Engineering Undergraduate Honors Theses

Post-quantum cryptography is a necessary countermeasure to protect against attacks from quantum computer. However, the post-quantum cryptography schemes are potentially vulnerable to side channel attacks. One such method of attacking involves creating bit-flips in victim memory through a process called Rowhammer. These attacks can vary in nature, but can involve rowhammering bits to raise the encryption scheme's decryption failure rate, or modifying the scheme's random seed. With a high enough decryption failure rate, it becomes feasible to generate sufficient information about the secret key to perform a key recovery attack. This thesis proposed two attacks on proposed post-quantum cryptography algorithms, …

Go to article

Critical Infrastructure Workforce Development Pods For Teaching Cybersecurity Using Netlab+, Gideon Sutterfield May 2023

Critical Infrastructure Workforce Development Pods For Teaching Cybersecurity Using Netlab+, Gideon Sutterfield

Computer Science and Computer Engineering Undergraduate Honors Theses

As digital automation for Industrial Control Systems has grown, so has its vulnerability to cyberattacks. The world of industry has responded effectively to this, but the world of academia is still lagging as its emphasis is still almost entirely on information technology. Considering this, we created a workforce development pod that serves as a hands-on learning module for teaching students key cybersecurity ideas surrounding operational technology using the NETLAB+ platform. A pod serves as the virtual environment where the learning exercise takes place. This project’s implementation involved the creation of a segmented network within the pod where a student starts …

Go to article

First Prev Next Last