Engineering Commons^™

Reducing Switching Noise And Losses In Two-Stage Electric Power Converters, Abhijeet Prem

Student Research Symposium

Advancements in semiconductor devices are enabling the design of better electrical power converter systems. Wide Bandgap (WBG) switching devices from Silicon Carbide and Gallium Nitride can operate at high temperatures, voltages, and frequencies with faster turn-on/off periods, improving converter performance over silicon devices. However, WBG technology is still new, and the rapid switching transitions of these devices lead to issues such as voltage overshoots, ringing, and electromagnetic interference, which need to be addressed for widespread adoption. This work introduces a new control method for reshaping the switching voltages, which overcomes the disadvantages of fast transition time without increasing the system's …

Affordable Bioprint Head-Adapter For 3d Printers, Andrew Ceralde, Dominic Drake, Noah Engles, Mohammad Alwan, Nevada Perry

Honors Capstones

Introduction: Addressing the need for affordable and accessible bioprinting technology, the Northern Illinois University bioprinting research and design project aims to democratize the field by developing an open source bioprint head. The initiative targets the prohibitive cost of commercial bioprinters by proposing an optimal design that can be integrated with widely available 3D printers, like the Creality Ender-3. This approach seeks to enable the widespread adoption of bioprinting technology, particularly for applications in tissue engineering and regenerative medicine.

Methods: Leveraging SolidWorks for design, the project employs a methodology that combines a precision extrusion system with thermal and UV crosslinking capabilities. …

Low Noise Amplifier For 5ghz Wi-Fi Applications On 22nm, Harshdeep Singh

Electrical Engineering Undergraduate Honors Theses

More devices than ever are being used to connect to the internet via Wi-Fi than ever before. This creates the demand for improving Wi-Fi standards and wireless transceivers. On of the most important stages of a Wi-Fi receiver is the low noise amplifier (LNA), this is because it is the very first stage after the antenna receives the signal. The LNA is responsible for boasting the incoming signal while adding a low amount of noise to boast the signal enough to make it receptible to the rest of the receiver system. This study sought to design an inductively degenerated common …

Enhancing Cybersecurity In Wireless Sensor Networks: Machine Learning, Blockchain And Future Perspectives, Ilemona Solomon Atawodi

Dissertations

Security in the Industrial Internet of Things encounters various security issues but the main issues can be broken down into three core issues: Availability, Integrity, and Confidentiality. Security challenges generally tend to be caused by a failure of the system in one of these areas or cause a failure in one of these areas. Therefore researching scalable solutions to these security issues is prudent to explore methods that could be applied to large-scale industrial IIoT with tens to hundreds of devices as well as small-scale systems on a tiny factory floor comprising of just a few devices. In our research, …

Bottling Automation System, Dylanie Tippit

Honors College Theses

This report details the complete design of an automated bottling system. Each bottle is 5.97 centimeters tall and has an outer diameter of 3.81 centimeters. The goal of the project is to successfully fill and cap twelve bottles in under three and a half minutes. The system will have two conveyors in series, a water dispenser, an electrolyte dispenser, capping station, Human Machine Interface (HMI) and Allen Bradley programmable logic controller (PLC). The water and electrolyte dispenser will have two ball valves in series, with the desired amount of volume to dispense the designated liquid. The capping station will be …

Building A Wireless Electronic Control Unit For An Electric Vehicle, Hector S. Sosa

2024 Spring Honors Capstone Projects - Archive

Modern vehicles have a variety of features such remote start systems, advance drive assist systems, smart suspension systems, and a feature rich infotainment system. With all this technology in the car, there exists a complex network of computers working together in conjunction to deliver the modern driving experience that many people have today. To be competitive in the market, auto manufacturers are tasked to add additional features to vehicles by adding additional or modifying electronic control units (ECUs). In this study, an ECU will be designed for a mock electric vehicle which contains an already established network of ECU’s. The …

Challenges For Room Temperature Operation Of Electrically Pumped Gesn Lasers, A. R. Ellis, D. A. Duffy, I. P. Marko, S. Acharya, W. Du, S. Q-. Yu, S. J. Sweeney

Electrical Engineering and Computer Science Faculty Publications and Presentations

Recent demonstrations of room-temperature lasing in optically pumped GeSn show promise for future CMOS compatible lasers for Si-photonics applications. However, challenges remain for electrically pumped devices. Investigation of the processes that limit device performance is therefore vital in aiding the production of future commercial devices. In this work, a combined experimental and modelling approach is utilised to explore the dominant loss processes in current devices. By manipulating the band structure of functioning devices using high hydrostatic pressure techniques at low temperature, the dominant carrier recombination pathways are identified. This reveals that 93 ± 5% of the threshold current is attributable …

Analyzing A Software Based Lossy Compression Algorithm On An Fpga Platform, Tripp Herlong

All Theses

In HPC, the ability to generate data is outpacing our hardware capabilities of storing said data. This presents the need for compression so we can keep important data preserved without costly hardware upgrades or worrying about hardware speed limitations. Traditional forms of compression are software based, which presents a speed issue that can lead to bottlenecks when storing data.Scientific data lossy compression methods such as SZ enable a speedup on memory transfer by simplifying computation to minimize the essential data size. SZx is a lightweight version of the popular SZ floating point compressor that may benefit from hardware acceleration. This …

Comprehensive Current Flow Modeling And Circuit Parameter Analysis For A Brushed Dc Motor Regenerative Braking System, Caleb Nathaniel Bondy

Legacy Theses & Dissertations (2009 - 2024)

The literature surrounding regenerative braking systems deals heavily with control system analysis and less to do with the electrical analysis of the circuitry itself. This thesis develops a step-by-step current flow model for a single-phase brushed DC motor regenerative braking system using the RL unit step-response equation as a starting point. This model and the equations derived from it will be analyzed to see what limitations arise from the circuitry on the overall performance of the system, such as non-ideal resistances, switching delays, and affects from current draw of accessory circuitry. The efficiency will be calculated in the context of …

Neural Network Based Digital Twin For A Half-Bridge Llc Resonant Converter, Nicholas Green

Legacy Theses & Dissertations (2009 - 2024)

This paper introduces a Neural Network based approach for creating a Digital Twin of a Half-Bridge LLC Resonant Converter. By using a set of measured inputs, the Digital Twin system can characterize the component values, and hard to measure switch characteristics such as the Junction Temperature or Gate-Source Capacitance. This capability is useful for reliability or health applications, and may also be useful for adaptive control. A case study is done for the LLC Resonant converter designed around an operating point. Data sweeps around that operating point are simulated to form a dataset. An introduction to Neural Networks is given …

Multi-Task Learning For Hybrid Communication Waveforms: Exploring Model Enhancement Techniques And Establishing Task Relationships, Saksham Dewan

Legacy Theses & Dissertations (2009 - 2024)

Wireless communications have become ubiquitous, enabling seamless connectivity and driv- ing innovations across various domains. As we look to the future, visible light communication (VLC) is a promising technology that offers the potential to revolutionize how we transmit and receive data. It seamlessly integrates multiple functionalities, including localization, control/sensing, and high-speed data transmission.This thesis proposes a multi-task learning deep convolutional neural network approach to optimize a hybrid waveform for VLC-enabled networks. By integrating Beacon Posi- tion Modulation (BPM), Beacon Phase Shift Keying (BPSK), and OFDM symbols within a virtual Pulse Width Modulation (PWM) envelope, this waveform supports localization, control/sensing, and …

Radio Frequency Interference (Rfi) Detection In Microwave Radiometry Using Multi-Dimensional Data Mining Techniques, Fathima Imara Mohamed Nazar

Legacy Theses & Dissertations (2009 - 2024)

Measurements of natural electromagnetic radiation from Earth using microwave radiometers provide deep insight into our planet and its environmental conditions. These insights are essential for quantifying, understanding, and predicting various geophysical processes, such as climate patterns, water cycles, carbon cycles, and more. These passive measurements are diverse and cover a wide range of frequencies, depending on the sensitivity of microwave radiation to changes in important geophysical parameters. However, it is important to note that the microwave spectrum is also utilized by active services, such as wireless communication networks and radars. As a result, Radio Frequency Interference (RFI) in the measurements …

Hierarchical Power Converter Physical Design, Tristan Mark Evans

Graduate Theses and Dissertations

The field of power electronics is undergoing rapid advancement that is driven by the need for further electrification in all aspects of power generation and transmission, transportation, and consumer goods. Recent advances in wide bandgap (WBG) semiconductor technologies continue to push their adoption in systems with higher power densities and conversion efficiencies. However, the way in which the components of these systems are designed has not kept pace with the rapidly evolving landscape of their applications and often requires costly, manual design iteration. Therefore, new methods are needed to improve this design process. Packaging of power devices is a critical …

High Performance Silicon Carbide Based Converters For Powertrain Electrification, Nan Lin

Graduate Theses and Dissertations

With the increasing concern towards environment protection, electric vehicles (EVs) and hybrid electric vehicles (HEVs) have become popular in recent years. They not only help reduce carbon emissions, but also come with other benefits such higher efficiency and better user experience. Many countries and vehicle manufactures have made their plans to keep up with this trend in vehicle electrification. Powertrain is an assembly of components in a vehicle that pushes it forward. As for EVs and HEVs, their powertrains are composed of one or more power electronics converters, which are significant to the system. Silicon carbide MOSFETs have shown superior …

Database And Machine Learning Model For Classifying Autism Spectrum Disorder From Smartphone Based Electroretinography, Rory Harris

Honors Scholar Theses

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that negatively affects a patient’s cognitive and communication aptitude and, therefore, can severely impact that patient’s quality of life. Because of this, early diagnosis is paramount. In recent studies, electroretinography (ERG), which is a measure of the retina’s electrical response to a brief flash of light into the eye, has shown promise in detecting ASD. Access to these scans can provide early diagnosis, improving well-being. Current ERG devices are very expensive due to their on board processing capabilities. This paper aims to create an ERG device using a smartphone as the main …

Phasor-Domain Short-Circuit Analysis Of Power Transmission Systems In The Presence Of Inverter-Based Resources, Dol Kunwar

All Theses

Although a power system is nonlinear during healthy operation because of constant power loads and controlled power injections from the sources, a conventional power system fed by synchronous generators is linear during fault, and can be represented by bus impedance matrix (Z-bus), which is useful in power system analyses such as short circuit (SC) analysis. However, With increasing penetration of inverter-based resources (IBRs) in the system, the assumption of linearity of the faulted network does not hold. This impacts the analyses relying on Z-bus and Thevenin’s equivalent impedance (TEI), such as certain protection schemes set using short circuit analysis. Therefore, …

4-Channel Spatially Multiplexed Communication System In Single-Core Optical Fibers, Ce Su

Theses and Dissertations

This dissertation delves into exploring and advancing spatial domain / space division multiplexing (SDM) technologies within single-core optical fibers, a frontier in optical fiber communications poised to meet the burgeoning global demand for data transmission. At the heart of this research is the pursuit to significantly enhance the capacity and efficiency of optical fiber communication systems without necessitating additional fiber infrastructure. This work unveils a new paradigm in optical fiber communications characterized by a pioneering 4-channel SDM system through a meticulous process encompassing theoretical modeling, computational simulations, design innovations, and rigorous experimental validations. Theoretical contributions include the development of refined …

Spin Disorder Control Of Topological Spin Texture, Hongrui Zhang, Yu-Tsun Shao, Xiang Chen, Binhua Zhang, Tianye Wang, Fanhao Meng, Kun Xu, Peter Meisenheimer, Xianzhe Chen, Xiaoxi Huang, Piush Behera, Sajid Husain, Tiancong Zhu, Hao Pan, Yanli Jia, Nick Settineri, Nathan Giles-Donovan, Zehao He, Andreas Scholl, Alpha N'Diaye, Padraic Shafer, Archana Raja, Changsong Xu, Lane W. Martin, Michael F. Crommie, Jie Yao, Ziqiang Qiu, Arun Majumdar, Laurent Bellaiche, David A. Muller, Robert J. Birgeneau, Ramamoorthy Ramesh

Physics Faculty Publications and Presentations

Stabilization of topological spin textures in layered magnets has the potential to drive the development of advanced low-dimensional spintronics devices. However, achieving reliable and flexible manipulation of the topological spin textures beyond skyrmion in a two-dimensional magnet system remains challenging. Here, we demonstrate the introduction of magnetic iron atoms between the van der Waals gap of a layered magnet, Fe₃GaTe₂, to modify local anisotropic magnetic interactions. Consequently, we present direct observations of the order-disorder skyrmion lattices transition. In addition, non-trivial topological solitons, such as skyrmioniums and skyrmion bags, are realized at room temperature. Our work highlights …

The National Center For Reliable Electric Power Transmission Test Facility, Anna Corbitt, Wesley G. Schwartz, Chris Farnell, Juan Carlos Balda, H. Alan Mantooth

Electrical Engineering and Computer Science Faculty Publications and Presentations

Globally, new technological solutions are being studied and developed by researchers in the field of power and energy systems. Before these solutions can be integrated into society as marketable products, thorough testing and validation of the design must be conducted. The National Center for Reliable Electric Power Transmission (NCREPT) is a unique high-power test facility located at the University of Arkansas, Fayetteville, AR, USA. NCREPT is a 12,000-square-foot laboratory space capable of testing power levels up to 6 MVA and offers testing at both the 480 V and 13.8 kV levels. NCREPT's capabilities expand outside of the scope of simply …

Photovoltaics And Battery-Based End-To-End Direct Current Sustainable Power Networks- Concept, Design, And Control, Vishwas Powar

All Dissertations

The consequences of climate change have emphasized the need for a power network that is centered around green, low-cost, and renewable sources of energy. Currently, photovoltaics (PV) and wind turbines are the only two technologies that can convert renewable energy from the sun and wind, respectively, into large-scale power for the electricity network. This dissertation aims to provide a novel solution to implement direct current-based architecture for PV generation coupled with lithium-ion battery storage in an efficient and sustainable manner. Such a power network can enable efficiency, reliability, low cost, and sustainability with minimum impact on the environment. The first …

Optimal Load Shedding During Service Restoration In Electrical Secondary Distribution Network Based On Reinforcement Learning, Rukia J. Mwifunyi

Tanzania Journal of Engineering and Technology (TJET)

Increased stress in traditional power systems results in blackouts due to voltage instability attributed to a mismatch between available capacity and load demand, especially in distribution networks. Service restoration schemes are designed to return power supply to the affected parts of the networks. The availability of insufficient supply is a complex problem that requires operational experience or an automatic system. The stochastic nature of load demand significantly impacts service restoration as it results in increased restored demand in case a fault occurs during off-peak hours and helps reduce overload if the fault occurs during peak hours. The study adopts an …

An Optimization Tool For A Standalone Photovoltaic System, Johanes Kasilima

Tanzania Journal of Engineering and Technology (TJET)

Stand-alone photovoltaic systems (SAPV) are often used in remote areas where access to grid electricity is limited. This system depends on solar energy. However, Photovoltaic (PV) systems need a greater initial investment than conventional sources of energy, and their effectiveness is reliant on a number of environmental conditions such as the unpredictable solar radiation. One step in reducing the investment cost of a PV system is determining the optimal size of solar PV components that minimize costs. This paper presents a Particle Swarm based optimization tool for sizing Stand-alone PV systems. The optimization tool selects the optimal Levelized Cost of …

Surface Treatments' Effects On The Capacitor's Dielectric Performance Under Electro-Thermal Stresses, Haider. M. Umran, Feipeng Wang

Karbala International Journal of Modern Science

Biaxial-oriented polypropylene (BOPP) films are characterized by unfavorable aging behavior because of their poor susceptibility to high temperatures, humidity, and high electric fields. This makes them unqualified to withstand harsh operating conditions, such as in capacitor applications. This study investigates the impact of annealing BOPP samples at 100 °C for five hours after fluorination at different times (15, 30, and 60 minutes) on their electrical and mechanical performance under electro-thermal stresses. Scanning electron microscope (SEM) images confirm that there is an increase in surface roughness and the formation of a dense layer of fluorine-containing groups monotonically with fluorination time. So, …

Study Of Interface Charges Between In-Situ Grown Dielectric And Gan/Algan Hfet Structure By Metal-Organic Chemical Vapor Deposition, Muhammad Hassan Tahir, Nifat Jahan, Md Ghulam Zakir

Faculty Publications

The integration of an oxide layer in metal-oxide-semiconductor high electron mobility transistors (MOSHFETs) plays a crucial role in minimizing gate leakage current and enabling wider gate voltage swings. In this study, we present the fabrication and characterization of GaN/AlGaN heterostructure field-effect transistors (HFETs) capped with a Ga₂O₃ dielectric layer. The oxide was deposited via an in-situ process within a single MOCVD reactor without vacuum interruption. Our findings demonstrate that the in-situ capped HFETs exhibit a significantly lower interface charge density of 4 × 10¹² cm⁻² compared to 1 × 10¹³ cm⁻²·eV⁻¹ observed in ex-situ grown counterparts. These results highlight the …

Study Of Indium-Silicon Co-Doped Gallium Oxide For Effective N-Type Doping, Muhammad Hassan Tahir, Nifat Jahan, Md Ghulam Zakir

Faculty Publications

We present the research efforts to achieve effective n-type doping in gallium oxide (Ga2O3), an ultrawide bandgap semiconductor, grown by metal-organic chemical vapor deposition (MOCVD). The application of semiconductors for power electronics requires wide and ultrawide bandgap materials that can be doped to create higher electron (n-type) or hole (p-type) densities. Ga2O3, with a bandgap of 4.9 eV, is an emerging and promising material. The bandgap of Ga2O3 is much higher than other wide bandgap material that have been adopted by or in the process of adoption by the industry for power electronics. However, the doping of Ga2O3 has some …

Gallium Oxide Based Avalanche Photo Detector, Muhammad Hassan Tahir Mr, Nifat Jahan, Md Ghulam Zakir

Faculty Publications

Gallium oxide (Ga₂O₃), an ultrawide bandgap semiconductor with a bandgap of 4.6 eV and a high critical electric field of 10.3 MV/cm, offers strong potential for high-performance avalanche photodetectors (APDs). This project explores the design and characterization of a Ga₂O₃-based APD featuring doped and undoped epitaxial layers optimized for high electric field generation and low thermal conductivity, enabling stable operation in high-temperature environments. Simulation results show a uniform electric field of 1 MV/cm under a 100 V applied bias, while material characterization confirms excellent surface smoothness with a mean roughness of ~1.1 nm and an electron mobility of 21.7 cm²/V·s …

Low Impedance, Durable, Self-Adhesive Hydrogel Epidermal Electrodes For Electrophysiology Recording, Naiyan Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditional electrodes used for electrophysiology recording, characterized by their hard, dry, and inanimate nature, are fundamentally mismatched with the soft, moist, and bioactive characteristics of biological tissues, leading to suboptimal skin-electrode interfaces. Hydrogel materials, mirroring the high water content and biocompatibility of biological tissues, emerge as promising candidates for epidermal electronic materials due to their adjustable physicochemical properties. However, challenges such as inadequate electrical conductivity, elevated skin impedance, unreliable adhesion in moist conditions, and performance decline from dehydration have significantly restricted the efficacy and applicability of hydrogel-based electrodes. In this thesis, we report a high-performance hydrogel epidermal electrode patch for …

Arkansas Tech University Modular Robotics Training System, Andrew L. Hilsdon, Jacob L. Crawford, Luke C. Hartman, Samuel E. Allen, Anthony W. Knudson, Kyle B. Mcmillan

ATU Scholars Symposium

Arkansas Tech University Modular Robotic Training System (ATUM RTS) project aims to combine two existing systems: The Georgia Tech Robotarium and the Micromouse maze-solving competition. The goal of ATUM RTS is to incorporate the challenge and excitement of maze-solving robots with the cloud-based learning system of the Robotarium. We intend to develop an automatic maze table with future remote capabilities to further student learning and engagement. By being able to create custom mazes with ATUM RTS, students will have access to a resource that will allow them to practically apply what they are learning in the classroom. The ATUM RTS …

Applications Of Supercapacitors In Robotic Systems, Charles Davis, Zachary Giese, Joseph Gober, Samuel Grisham, Avery Mahan

ATU Scholars Symposium

This project explores the utilization of a bespoke supercapacitor system to energize and propel a robot across various challenging courses. The custom supercapacitor setup serves as the primary power source, providing rapid charging capabilities and high energy density. The research investigates the integration of this innovative power solution into the robot's design, aiming to optimize its performance and endurance in competitive environments.

Towards A Wearable Device For Measuring Impedance Plethysmography Of The Radial Artery, Pritom Chowdhury

Dartmouth College Master’s Theses

Recent advancements in bioimpedance technology have demonstrated significant promise in the application of cardiac health monitoring. This research explores the design and development of a forearm-based wearable bioimpedance device for non-invasive measurement of heart rate and respiratory rate at an accuracy level comparable to medical-grade monitors. It utilizes a tetrapolar electrode configuration to analyze bioimpedance changes in the radial artery due to blood flow.

An ongoing aspect of this work involves the preliminary development of an embedded framework intended to integrate signal generation, acquisition, and processing within the device to achieve compact and efficient system design, anticipated to contribute to …