Engineering Commons^™

Development Of A Multi-Use Modular Microfluidic Platform Using 3d Printing, Carson Emeigh

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Microfluidic lab-on-a-chip (LoC) technology has driven numerous innovations due to their ability to perform laboratory-scale experiments on a single chip using microchannels. Although LoC technology has been innovative, it still suffers from limitations related to its fabrication and design flexibility. Typical LoC fabrication, with photolithography, is time consuming, expensive, and inflexible. To overcome the limitations of LoC devices, modular microfluidic platforms have been developed where multiple microfluidic modules, each with a specific function or group of functions, can be combined on a single platform. Modular microfluidics have overcome some of the limitations of LoC devices, but currently, their fabrication is …

Entropy-Infused Deep Learning Loss Function For Capturing Extreme Values In Wind Power Forecasting, Mucun Sun, Sergio Valdez, Juan M. Perez, Kevin Garcia, Gael Galvan, Cesar Cruz, Yifeng Gao, Li Zhang

Electrical and Computer Engineering Faculty Publications

Extreme scenarios in wind power generation occur with higher frequency and larger magnitude in the recent years due to the ever-increasing extreme meteorological factors. Accurate forecasting of the occurrence of extreme values in wind power generation is of great concern to ensure reliable power system operation. Recently, deep learning models have surged in popularity for wind power forecasting, with the mean squared error (MSE) loss function being commonly used. However, the MSE loss function, being sensitive to extreme values, disproportionately penalizes larger errors, cannot adequately capture the extreme values present in wind energy data, and novel loss functions have seldom …

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 …

Investigation Of Pra For Rapid Part Replacement, John Lazenby

Honors Theses

As the electronics industry transitions to using commercial-off-the-shelf (COTS) devices of increasingly smaller technologies, radiation effects analysis becomes more significant in mission planning. In this work a probabilistic risk assessment (PRA) program, RadSTATS, is used in the analysis of various COTS memories in a radiation environment. The probabilities that the bits in memory will be flipped due to single event upset (SEU) rates are calculated for each memory, volatile and non-volatile. The unavailability of bits was discovered to increase with increasing storage capacity. Methods of error detection and correction (EDAC) between the same manufacturer were seen to decrease at unavailability …

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, …

Effect Of Patient Specific Blood Biomarkers On Nanoparticle - Cell Interactions, Veronica Gabriela Contreras

Open Access Theses & Dissertations

Nanoparticles are currently known to be a promising material class for bio-applications in drug delivery and vaccine development. Using gold nanoparticles of varied sizes, in this case 45 and 100 nanometers as a model nanomaterial system, we investigated how patients' blood physiology and chemistry (such as solute, protein, lipid levels) affect the biological response to bionanomaterials. When nanoparticles are injected into the body, biomolecules in the blood adsorb to the nanoparticle's surface to form a biomolecular corona that is specific to the patient's unique blood composition. This biomolecular corona is important because it affects the in vivo fate and biodistribution …

Summonable Construction Delivery Robot, Kevin M. Lewis

Honors Capstones

In many different construction industries, there is a need for tools, parts, and other necessary items to be transported quickly and efficiently over various types of terrain. Human resources have often been used to address these needs, which can become very time and cost inefficient over long periods. The design proposal here is aimed at addressing this need by developing an autonomous outdoor mobile robot based on a quadrupedal robot design. This approach differs by incorporating a wheeled and quadrupedal hybrid actuation system that provides terrain negotiation and speed at the appropriate times. The team uses Robot Operating System (ROS) …

Redirection Of Current In A Dense Plasma Focus, Rocky Gonzalez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mission Support & Test Services (MSTS) reports that significant amounts of energy needed for generating high energy neutrons is lost within a Dense Plasma Focus between its pinch-end of the anode stalk and at its base near the insulating sleeve. It is their mission and the goal of this research effort to both experimentally and theoretically study current redirection in a DPF during and after pinch dynamics. It is hypothesized that current redirection, due to restrike, behind the dynamic sheath of a dense plasma focus will result in a measurable change in the magnetic field along the longitudinal axis …

Techniques To Overcome Energy Storage Limitations In Electric Vehicles, Matthew J. Hansen

All Graduate Theses and Dissertations, Fall 2023 to Present

Electric vehicles are becoming increasingly popular, battery limitations (cost, size, and weight) complicate electric vehicle adoption. While important research on battery development is ongoing, this dissertation discusses two main approaches to overcome those limitations within the existing battery technology paradigm. Those thrusts are: improving battery health through an optimal charging strategy and minimizing necessary battery size through dynamic wireless power transfer. In this dissertation, relevant literature is discussed, with opportunities for further development considered. Within the two thrusts, three objectives sharpen the focus of the research presented here. First, a planning tool is defined for a battery electric bus fleet. …

Design And Implementation Of An Accelerated Lifetime Testing Platform For Silicon Carbide Mosfets, Conner Deppe

All Graduate Theses and Dissertations, Fall 2023 to Present

In the last several years, the United States has seen a significant increase in sales of electric vehicles. The increase of electric vehicles brings the need for increased availability of public charging stations. In the last two years, satisfaction levels for public chargers have fallen significantly due to unreliability, which is raising concerns for new potential electric vehicle owners. To mitigate the reliability concerns, chargers must be physically understood so they can be consistently monitored to assess their health status. To understand the electric vehicle charging reliability, electrical components must first be understood. In the cutting-edge charging technology, the relatively …

Brain-Inspired Continual Learning: Rethinking The Role Of Features In The Stability-Plasticity Dilemma, Hikmat Khan

Theses and Dissertations

Continual learning (CL) enables deep learning models to learn new tasks sequentially while preserving performance on previously learned tasks, akin to the human's ability to accumulate knowledge over time. However, existing approaches to CL face the challenge of catastrophic forgetting, which occurs when a model's performance on previously learned tasks declines after learning the new task. In this dissertation, we focus on the crucial role of input data features in determining the robustness of CL models to mitigate catastrophic forgetting. We propose a framework to create CL-robustified versions of standard datasets using a pre-trained Oracle CL model. Our experiments show …

Vr Circuit Simulation With Advanced Visualization For Enhancing Comprehension In Electrical Engineering, Elliott Wolbach

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

As technology advances, the field of electrical and computer engineering continuously demands innovative tools and methodologies to facilitate effective learning and comprehension of fundamental concepts. Through a comprehensive literature review, it was discovered that there was a gap in the current research on using VR technology to effectively visualize and comprehend non-observable electrical characteristics of electronic circuits. This thesis explores the integration of Virtual Reality (VR) technology and real-time electronic circuit simulation with enhanced visualization of non-observable concepts such as voltage distribution and current flow within these circuits. The primary objective is to develop an immersive educational platform that makes …

Design And Optimization Of A Novel Monolithic Spring For High-Frequency Press-Pack Sic Fet Modules, Bogac Canbaz

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Silicon Carbide (SiC) Field-Effect Transistor (FET) modules lead the way in power electronics, being superior in efficiency and robustness for high-frequency applications. The shift towards SiC from traditional silicon (Si)-based devices is driven by its superior thermal conductivity, higher electric field strength, and operational efficiency at elevated temperatures. These features are critical for the development of next-generation, grid-oriented power converters aimed at enhancing the reliability and sustainability of power systems. This research focuses on high-frequency press-pack (HFPP) SiC FET modules, addressing the primary challenge of miniaturizing SiC FET dies without compromising performance, through an innovative press-contact design essential for increased …

An Investigation Of Information Structures In Dna, Joel Mohrmann

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The information-containing nature of the DNA molecule has been long known and observed. One technique for quantifying the relationships existing within the information contained in DNA sequences is an entity from information theory known as the average mutual information (AMI) profile. This investigation sought to use principally the AMI profile along with a few other metrics to explore the structure of the information contained in DNA sequences.

Treating DNA sequences as an information source, several computational methods were employed to model their information structure. Maximum likelihood and maximum a posteriori estimators were used to predict missing bases in DNA sequences. …

Surface Chemistry Of Femtosecond Laser Processed Surfaces, Graham Kaufman

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Micromachining and surface functionalization with femtosecond lasers is a rapidly developing technology in the field of materials and interfacial sciences due to its flexibility towards materials, tunability in surface features, and prospects for scalability. Many interfacial applications have been shown to be enhanced with femtosecond laser-induced surface texturing including two-phase heat transfer, antimicrobial properties, electrochemical systems and more. However, without ideal surface chemistry, the enhancements cannot be optimized for a given application. Surfaces functionalized by femtosecond lasers tend to have transient surface chemistries when exposed to the atmosphere, changing important interfacial properties like the interaction of the solid surfaces and …

Keratin-Based Film: Waste To Bioplastic, Emma Bond

University Honors College

The solution to plastic lies in alternative materials, like bioplastics. One such possibility is keratin-based films. They are made from sources that are already deemed to be waste and that all regions of the world are abundant in. Manufacturing values a one-size-fits-all solution and keratin being plentiful worldwide fulfills that set standard. The films’ properties, which are important to the basic needs of a package, vary with different additives and the type of keratin used. α-keratin and β-keratin have different strengths and are found in nature in different sources. The resource focused on was chicken feathers, which produce more β-keratin …

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 …

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 …

Mems Optical Cavities For Low Power Communication., Jacob Schopp

Electronic Theses and Dissertations

This thesis discusses the use of MEMS (microelectromechanical systems) optical cavities for use in low power communication. MEMS optical cavities are thin air gaps between an actuated MEMS mirror and a fixed glass encapsulation. By moving the MEMS mirror the reflectivity of the MEMS optical cavity can be changed. This change in reflectivity can be used to transmit information passively by modulating reflected light intensity instead of generating new light using a light source. These MEMS optical cavities are demonstrated using optical fibers for illumination delivery and reflected light collection. In addition to being reflected for communication, the illuminating light …

An Edge Computing System With Amd Xilinx Fpga Ai Customer Platform For Advanced Driver Assistance System, Tsun Kuang Chi, Tsung Yi Chen, Yu Chen Lin, Ting Lan Lin, Jun Ting Zhang, Cheng Lin Lu, Shih Lun Chen, Kuo Chen Li, Patricia Angela R. Abu

Department of Information Systems & Computer Science Faculty Publications

The convergence of edge computing systems with Field-Programmable Gate Array (FPGA) technology has shown considerable promise in enhancing real-time applications across various domains. This paper presents an innovative edge computing system design specifically tailored for pavement defect detection within the Advanced Driver-Assistance Systems (ADASs) domain. The system seamlessly integrates the AMD Xilinx AI platform into a customized circuit configuration, capitalizing on its capabilities. Utilizing cameras as input sensors to capture road scenes, the system employs a Deep Learning Processing Unit (DPU) to execute the YOLOv3 model, enabling the identification of three distinct types of pavement defects with high accuracy and …

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 …

Developing General Purpose Apps To Automate Image Analysis Of Wave-Augmented-Varicose-Explosion Atomization And Other Multi-Phase Interfacial Flows, Ethan Newkirk

Senior Honors Theses

Atomization involves disrupting a flow of contiguous liquid into small droplets ranging from one submicron to several hundred microns (micrometers) in diameter through the processes of exerting sufficient forces that disrupt the retaining surface tensions of the liquid. Understanding this phenomenon requires high-speed imaging from physical models or rigorous multiphase computational fluid dynamics models. We produce a MATLAB application that utilizes various methods of image analysis to quickly analyze and store mathematical data from detailed image analyses. We present a user with numerous tools and capabilities that provide results that deviate from 1.8% to 8.9% of the original image sequence …

Model-Based And Model-Free Control Approaches In Subgrids: A Conceptual Review Of Control Strategies In Microgrids, Omobolade H. Abioye

Theses and Dissertations

Increased reliance on the power grid and concerns over climate change issues have resulted in the rapid adoption of renewable energy technologies. Consequently, it is necessary to consider how renewable energy resources are combined and controlled. The microgrid serves as the control center for distributed energy resources. This thesis paper introduces the microgrid elements and framework, its control strategies highlighting frequency and voltage control, and the prospects of artificial intelligence for control, considering two significant approaches. Key components of sub grids like the energy management system (EMS) and energy storage systems (ESSs) are discussed, and lastly, the …

Hand Movement Analysis For Surgical Suturing Skill Assessment, Amir Mehdi Shayan

All Theses

To enhance patient safety, surgical education is increasingly incorporating simulation for formative skills assessment and training. However, many standardized assessment tools rely on human raters for performance assessment, which is resource-intensive and subjective. Simulators that provide automated and objective metrics from sensor data can address this limitation. This thesis presents an instrumented bench suturing simulator, patterned after the Clock Face (CF) radial suturing model from the Fundamentals of Vascular Surgery (FVS), for automated and objective assessment of open suturing skills by particularly focusing on biomechanical analysis of hand movements. For this research, 97 participants (35 attending surgeons and fellows, 32 …

Titanium Dioxide Nanomaterial Ink Production Through Laser Ablation Synthesis In Solution For Printed Electronics Applications, Devyn Duryea, Nicholas Mckibben, Jacob Manzi, Taylor Brennan, Harish Subbaraman, David Estrada, Nirmala Kandadai

Electrical and Computer Engineering Faculty Publications and Presentations

Flexible and printed electronics have become increasingly popular as they make possible the production of flexible, low-cost, multifunction devices that are unachievable through traditional manufacturing methods. The printed films are significantly impacted and thus limited by the existing ink production process. Herein, an alternate technique of generating high-quality titanium dioxide (TiO₂) nanoparticle ink compatible with aerosol jet printing using laser ablation synthesis in solution (LASiS) is showcased. Dynamic light scattering data and transmission electron microscopy confirm the particle size distribution. UV–vis measurements are performed, and the Beer–Lambert relationship is used to determine the concentration of the generated ink. …

Head Impact Measurement Using Piezoelectric Sensors, Huda Abdulla Alnuaimi

Theses

The importance of safety measures cannot be overstated, especially when it comes to protecting the human head. Head injuries can have severe, life-altering consequences, as the head is crucial for controlling the entire body. Unlike machines that store data, the human brain's capacity to retain thoughts and memories can be significantly affected by even a single injury. This thesis introduces a method for predicting the specific area of the head that might be injured during an impact. The prediction is based on the intensity and duration of the impact. The innovation of this thesis lies in the use of piezoelectric …

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 …