Engineering Commons^™

Experimental And Computational Studies Of Functionalized Carbon Nanotubes For Use In Energy Storage Devices And Membranes, Emine S. Karaman

Dissertations

Electrolytes with good interfacial stability are a crucial component of any electrochemical device. The development of novel gel polymer electrolytes (GEs) with good interface stability and better manufacturability is important for the development of the next generation electrochemical devices. Gel electrolytes are hybrid electrolyte materials, combining benefits of both liquid and solid systems. Compared with liquid and solid electrolytes, GEs open new design opportunities and do not require rigorous encapsulation methods. In this dissertation, studies on functionalized carbon nanotubes (fCNTs) and graphene oxide (GO) doped polyvinyl alcohol (PVA) based gel electrolytes (GEs) are reported. The ionic conductivity and mechanical strength …

Photoelectrochemical Sensing Based On Zr-Mofs For Homocysteine Detection, Wen-Xia Dong, Guang-Ming Wen, Bin Liu, Zhong-Ping Li

Journal of Electrochemistry

Due to the independent form of the light source and detection system, photoelectrochemical (PEC) sensor has the advantages of low background, high sensitivity and simple operation. So far, PEC systems have been widely used in the fields including the actual detection of metal ions, biological antibodies or antigens in environmental pollutants. When the photosensitive material is irradiated by a light source with an energy being equal to or greater than its band gap, electrons (e-) transition occurs from the valence band to the conduction band, leaving a hole (h+), at the same time, the generated electron-hole pair (e-/h+) separate, and …

Functional Sulfate Electrolytes Enable The Enhanced Cycling Stability Of Nati2(Po4)3/C Anode Material For Aqueous Sodium-Ion Batteries, Shu-Jin Li, Zhi-Kang Cao, Wen-Kai Wang, Xiao-Han Zhang, Xing-De Xiang

Journal of Electrochemistry

Aqueous sodium-ion batteries show promising application in fields of large-scale storage of intermittent renewable energies owing to the earth-abundant sodium resources and incombustible aqueous electrolytes. Primary factors determining whether they can be commercially utilized are low cost and long lifetime. Among current electrode materials, NASICON-type NaTi₂(PO₄)₃ arouses wide interests as an anode material for aqueous sodium-ion batteries as it offers a high specific capacity, fast Na-transport ability and reasonable working potential, however, suffering from insufficient cycling performance caused by severe dissolution of active materials in traditional aqueous electrolytes. In this work, a functional sulfate electrolyte …

Effect Of Glycol Based Coolant Pollution On Pem Fuel Cells Stack And Recovery Measures, Cong-Yi Zhu, Xiao-Hui Li, Quan-Quan Gan

Journal of Electrochemistry

As the heat conduction medium of fuel cell cooling system, coolant is very important for the thermal management of fuel cell stack. In practical application, coolant leakage into the stack often occurs. Due to the randomness of fault location of components, the location of coolant leakage is uncertain, which may occur on the cathode side or anode side of some or all single cells. The main effects of coolant pollution on fuel cell stack are as follows: the output of open circuit voltage decreases sharply, the consistency of single cells voltage decreases and so on, which seriously affects the normal …

Copper Nanoparticles In-Situ Anchored On Nitrogen-Doped Carbon For High-Efficiency Oxygen Reduction Reaction Electrocatalyst, Hui-Fang Yuan, Yue Zhang, Xing-Wu Zhai, Li-Bing Hu, Gui-Xian Ge, Gang Wang, Feng Yu, Bin Dai

Journal of Electrochemistry

Compared with noble metal platinum (Pt)-based catalysts, inexpensive non-noble metal electrocatalysts have attracted extensive attention for oxygen reduction reaction (ORR). Herein, chitosan as a kind of biomass resource rich in nitrogen and carbon was used to prepare nitrogen-doped carbon (N-C) and N-C in-situ anchored by copper nanoparticles (Cu/N-C). The as-obtained N-C and Cu/N-C nanoparticles were successfully used as non-noble eletrocatalysts tested for ORR. Compared with the N-C, the Cu/N-C showed the high surface area of 607.3 m 2·g-1 with the mean pore size of 2.5 nm and the pore volume of 0.40 cm3·g-1. The most positive Gibbs free …

Cyclic Voltammetric Simulations On Batteries With Porous Electrodes, Xue-Fan Cai, Sheng Sun

Journal of Electrochemistry

Lithium-ion batteries (LIBs) are among the most widely used energy storage devices. Whole-cell modeling and simulations of LIBs can optimize the design of batteries with lower costs and higher speeds. The Pseudo-Two-Dimensional (P2D) electrochemical model is among the most famous whole-cell models and widely applied in LIB simulations. P2D model consists of a series of kinetic equations to model Li+/Li diffusion in working/counter electrodes and electrolytes, which are filled in the porous electrodes and separator, and reactions at the interface of electrolyte and active particles. The traditional applications of P2D model, however, are limited to the cases where the current …

Formation And Morphological Evolution Of Nanoporous Anodized Iron Oxide Films, Jin-Wei Cao, Nan Gao, Zhao-Qing Gao, Chen Wang, Sheng-Yan Shang, Yun-Peng Wang, Hai-Tao Ma

Journal of Electrochemistry

The preparation of iron oxide films with nanoporous structure by anodization has attracted much attention for its potential applications. However, the formation mechanism of porous structure during anodization is still unclear. In this paper, the composition of anodic current during the formation of nanoporous anodized iron oxide film was analyzed in combination with the current density-potential response (I-V curve) and the derivation of Faraday’s law. The results showed that the anodic current consisted of an ionic current (leading to the migration of ions to form oxide) and an electronic current (leading to the oxygen evolution), and the …

Influence Of Heat Treatment Time On Cathode Material Cr8O21 For Lithium Battery, Jiu-Kang Teng, Qing-Jie Wang, Liang Zhang, Hong-Mei Zhang, Xiao-Tao Chen, Peng Zhang, Jin-Bao Zhao

Journal of Electrochemistry

Chromium oxide (Cr₈O₂₁) cathode material for lithium batteries was synthesized by thermal decomposition of chromium trioxide (CrO₃) at high temperature. The electrochemical properties of chromium oxide depended on the time and temperature during the heat treatment. Pure phase chromium oxide was prepared, and the effects of heat treatment time on the structures and electrochemical properties of Cr₈O₂₁ were systematically studied. The first discharge mechanism of chromium oxide in lithium batteries was explored, and the results were similar to that in lithium-sulfur batteries. The crystal phases and electrochemical properties of the prepared …

Structure Analysis Of Pemfc Cathode Catalyst Layer, Rui-Qing Wang, Sheng Sui

Journal of Electrochemistry

The sluggish oxygen reduction reaction (ORR) on the cathode of the proton exchange membrane fuel cell (PEMFC) has always been one of the key factors limiting its commercialization. The optimization of the cathode catalytic layer structure plays an important role in improving fuel cell performance and reducing production costs. In this paper, two different catalysts (platinum nanoparticles (Pt-NPs) and platinum nanowires (Pt-NWs)) were prepared by using catalyst coated substrate (CCS) method. By constructing a double-layer catalytic layer structure, we analyzed the effect of different catalytic layer structures by performing a single cell test. The results showed that the dense platinum …

Nitrogen-Sulfur Co-Doped Porous Carbon Preparation And Its Application In Lithium-Sulfur Batteries, Zhao Gui-Xiang, Hafiz Zaki Ahmed Wail, Zhu Fu-Liang

Journal of Electrochemistry

In recent years, lithium-sulfur (Li-S) batteries have been considered as a promising candidate for the next generation of energy storage system due to their ultrahigh theoretical capacity (1675 mAh·g-1) and energy density (2600 Wh·kg-1). However, the practical application of Li-S batteries is seriously limited by their insulating nature of sulfur, the shuttle effect of polysulfides (LiPSs), and volume expansion during charging and discharging. To overcome those disadvantages, one of the commonly methods is to infiltrate sulfur into porous conductive carbon framework, such as porous carbon, hollow carbon spheres, graphene, carbon nanotubes and some composites of the above structures to achieve …

Tri-Level Hierarchical Coordinated Control Of A Largescale Electric Vehicle Charging In The Smart Grid, Tawfiq M. Aljohani

FIU Electronic Theses and Dissertations

Electric Vehicles (EVs) are considered one of humanity's greatest hopes to combat the climate change crises in light of their great potentials to reduce Greenhouse Gases (GHG) emissions from two main sources: the electric power industry and the fossil-based transportation sector. To help expedite the large-scale adoption of EVs on the roads, optimal solutions are needed to overcome the technical and operational barriers that face the electrical network. This is due to the introduction of significant load levels from EVs; a substantial number is expected during peak demand hours. This dissertation addresses the various interaction between different parts of the …

Enhanced Security Utilizing Side Channel Data Analysis, Michael Taylor

Computer Science and Engineering Theses and Dissertations

The physical state of a system is affected by the activities and processes in which it is tasked with carrying out. In the past there have been many instances where such physical changes have been exploited by bad actors in order to gain insight into the operational state and even the data being held on a system. This method of side channel exploitation is very often effective due to the relative difficulty of obfuscating activity on a physical level. However, in order to take advantage of side channel data streams one must have a detailed working knowledge of how a …

Net-Zero Energy Districts And The Grid: An Energy-Economic Feasibility Case-Study Of The National Western Center In Denver, Co, Usa, Ben Saarloos, Jason C. Quinn

Faculty Work Comprehensive List

Given the enormous impact of buildings on energy consumption, it is important to continue the development of net-zero energy districts. Opportunities exist for energy efficiency and renewable energy on a district level that may not be feasible in individual buildings. Due to the intermittent nature of many renewable energy sources, net-zero energy districts are dependent on the energy grid. The novelty of this work is to quantify and optimize the economic cost and grid independence of a net-zero energy district using the National Western Center (NWC) in Denver, CO, USA as a case study. The NWC is a 100+ ha …

Modeling Electric Energy Generation In Ercot During Extreme Weather Events And The Impact Renewable Energy Has On Grid Reliability, Adam R. Ruthford, Bivin Sadler

SMU Data Science Review

This paper shows the inadequacy of current grid backup supplies, their ongoing threat to grid reliability, and the increased risk of customer blackouts. This paper also examines reliability concerns caused by renewable energy sources under more normal operating conditions. This paper seeks to model the impacts of extreme weather on ERCOTs grid. Unusual weather patterns require that the electrical grid operates in conditions outside normal operating parameters. Electrical system demand can spike well above normal levels. At the same time, weather influences can change the operating envelope of electrical generation equipment. The ERCOT grid has changed from its’ traditional mix …

Torque Vectoring To Maximize Straight-Line Efficiency In An All-Electric Vehicle With Independent Rear Motor Control, William Blake Brown

Theses and Dissertations

BEVs are a critical pathway towards achieving energy independence and meeting greenhouse and pollutant gas reduction goals in the current and future transportation sector [1]. Automotive manufacturers are increasingly investing in the refinement of electric vehicles as they are becoming an increasingly popular response to the global need for reduced transportation emissions. Therefore, there is a desire to extract the most fuel economy from a vehicle as possible. Some areas that manufacturers spend much effort on include minimizing the vehicle’s mass, body drag coefficient, and drag within the powertrain. When these values are defined or unchangeable, interest is driven to …

Modeling And Control Of Power Electronics Interfaced Load For Transmission Power Network Analysis, Shuyao Wang

Doctoral Dissertations

The penetration level of power electronics (PE) interfaced loads has been gradually increasing in recent years. It is beneficial to equip the electric load with a PE interface since it allows for more advanced control of the load performance. Furthermore, the increasing penetration of PE interfaced loads will bring both challenges and opportunities to power network resilience and reliability.

However, the lack of modeling and control design for PE interfaced load units in the transmission-level power network analysis, especially for these high-penetrated high-power-rating load applications, limits the accuracy of evaluating the dynamic performance and stability status of the power network. …

Design Considerations For Gan-Based Photovoltaic Inverter And Solid-State Circuit Breaker, Zhe Yang

Doctoral Dissertations

Featuring low specific on-state resistance, high switching speed, and zero reverse recovery current, Gallium Nitride (GaN) transistor is becoming one of the most promising devices for power electronic applications. This dissertation presents some design considerations for photovoltaic (PV) inverters and solid-state circuit breakers (SSCBs) using GaN devices. Several related challenges and solutions will be discussed in this dissertation.

First, the filter design for full bridge PV inverter is discussed, which includes the design and optimization of individual inductor and overall power filter. The inductor design takes the fringing effect into account, and achieves optimal design with simple algorithm. Then, the …

Switching Performance Evaluation, Design, And Test Of A Robust 10 Kv Sic Mosfet Based Phase Leg For Modular Medium Voltage Converters, Xingxuan Huang

Doctoral Dissertations

10 kV SiC MOSFETs are one of the most promising power semiconductor devices for next-generation high-performance modular medium voltage (MV) converters. With extraordinary device characteristics, 10 kV SiC MOSFETs also bring a variety of challenges in the design and test of MV converters. To tackle these inherent challenges, this dissertation focuses on a robust half bridge (HB) phase leg based on 10 kV SiC MOSFETs for modular MV converters. A baseline design and test of the phase leg is established first as the foundation of the research in this dissertation.

Thorough evaluation of 10 kV SiC MOSFETs’ switching performance in …

Modeling And Control Of A 7-Level Switched Capacitor Rectifier For Wireless Power Transfer Systems, Spencer Cochran

Doctoral Dissertations

Wireless power continues to increase in popularity for consumer device charging. Rectifier characteristics like efficiency, compactness, impedance tunability, and harmonic content make the multi-level switched capacitor rectifier (MSC) an exceptional candidate for modern WPT systems. The MSC shares the voltage conversion characteristics of a post-rectification buck-boost topology, reduces waveform distortion via its multi-level modulation scheme, demonstrates tank tunability via the phase control inherent to actively switched rectifiers, and accomplishes all this without a bulky filter inductor. In this work, the MSC WPT system operation is explained, and a loss model is constructed. A prototype system is used to validate the …

Directional Spectral Solar Energy For Building Performance: From Simulation To Cyber-Physical Prototype, Joseph Del Rocco

Electronic Theses and Dissertations, 2020-2023

The original research and development in this dissertation contributes to the field of building performance by actively harnessing a wider spectrum of directional solar radiation for use in buildings. Solar radiation (energy) is often grouped by wavelength measurement into the spectra ultraviolet (UV), visible (light), and short and long-wave infrared (heat) on the electromagnetic spectrum. While some of this energy is directly absorbed or deflected by our atmosphere, most of it passes through, scatters about, and collides with our planet. Modern building performance simulations, tools, and control systems often oversimplify this energy into scalar values for light and heat, when …

Performance Loss Rate And Temperature Modeling In Predictive Energy Yield Programs For Utility-Scale Solar Power Plants, Katelynn M. Dinius

Master's Theses

The Gold Tree Solar Farm, designed by REC Solar, has a rated output power of 4.5 MW and began operation in 2018 to provide electricity to Cal Poly’s campus. Gold Tree Solar Farm site terrain consists of rolling hills and uneven slopes. The uneven typography results in interrow shading, requiring a modified tracking control algorithm to maximize power production. Predicting a utility solar field’s lifetime energy yield is a critical step in assessing project feasibility and calculating project revenue. The MATLAB-based predictive power model developed for this field overpredicted power in the middle of the day. The purpose of this …

Analysis Of Deep Learning Methods For Wired Ethernet Physical Layer Security Of Operational Technology, Lucas Torlay

All Theses

The cybersecurity of power systems is jeopardized by the threat of spoofing and man-in-the-middle style attacks due to a lack of physical layer device authentication techniques for operational technology (OT) communication networks. OT networks cannot support the active probing cybersecurity methods that are popular in information technology (IT) networks. Furthermore, both active and passive scanning techniques are susceptible to medium access control (MAC) address spoofing when operating at Layer 2 of the Open Systems Interconnection (OSI) model. This thesis aims to analyze the role of deep learning in passively authenticating Ethernet devices by their communication signals. This method operates at …

Ac/Dc Led Light Bulb Adaptor With Internal Rechargeable Batteries, Esteban A. Rubio, Matthew R. Delaby

Electrical Engineering

To make a sustainable product and provide a temporary source of lights on during emergencies, this project aims to create a small unit that can be attached to a light bulb of any variety and connect it to a socket. Within the device is a rechargeable battery that, when the device is not connected to an 120V AC, 240V AC, or 48V DC power source, will power the light for a short period of time. The battery can be charged during the standard operation of the device and can be powered by the US and EU standard outlet voltages as …

Simulation And Fabrication Of All Oxide-Based Ito/Tio2/Cuo/Au Heterostructure For Solar Cell Applications, Sajal Islam

MSU Graduate Theses

Oxide heterostructures have drawn great attention lately, due to their environment-friendly properties and potential applications in optoelectronic devices. In this work, a simulation study of a heterojunction solar cell was performed with SCAPS (a solar cell simulator) using TiO2 as an n-type and CuO as a p-type layer. The thickness and the dopant-dependent simulations have shown that the solar cell operates at a maximum efficiency of 19.2% when the thickness of the TiO2/CuO layers is chosen 1.4µm/1.2µm compared to the 11.5% efficiency when FTO is replaced with ITO. An indium-doped tin oxide (ITO) vs fluorine-doped tin oxide (FTO) comparison study …

Partial Discharge Testing And Detection Under Pwm Voltage, John Meadors

Masters Theses

Partial Discharge detection and measurement is an important part of electric insulation design. However, in PWM (pulse width modulation) voltage source converter environments, the noise resulting from switching voltage (rise and fall times of tens of nanoseconds) makes detection and extraction of partial discharge difficult. Unique methods of partial discharge detection are needed to address and decouple the noise from partial discharge measurements. PWM voltage can feature high switching speeds and high dv/dt during voltage switching. These PWM voltage behaviors are not found in traditional utility high voltage applications, and the effects that this type of voltage has on insulation …

Roi-Aware Content-Adaptive Video Streaming System For Power Savings, William Oswald

<strong> Theses and Dissertations </strong>

The demand for mobile video streams is constantly increasing. With this demand comes a need for mobile devices to receive more videos at ever increasing quality. However, due to the large size of video data and intensive computational requirements, video streaming requires frequent memory access that consumes a substantial amount of mobile device power; as a result, the battery life of mobile devices is limited. In this thesis, a video content-adaptable Region-of-Interest (ROI)-aware video storage technique that promotes power savings is presented. During the video encoding process on the transmitting server, based on the macroblock variance and ROI characterization, the …

Roadway-Embedded Transmitters And Multi-Pad Receivers For High Power Dynamic Wireless Power Transfer, Benny J. Varghese

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Electric vehicles (EVs) offer considerable economic and environmental benefits to society. Despite the decreasing vehicle costs and increasing range of newer EVs, the problem of range anxiety still exists. Range anxiety, at its core, is an issue of charging speeds rather than a concern about the driving range. Dynamic wireless charging of EVs is seen as a potential solution to this issue of range anxiety. Further, wireless charging technology also helps the push towards level 5 autonomy and opens new opportunities for how an EV can be utilized.

Dynamic wireless power transfer (DWPT) systems typically require a high initial investment …

A Double-Sided Stack Low-Inductance Wire-Bondless Sic Power Module With A Ceramic Interposer, Si Huang

Graduate Theses and Dissertations

The objective of this dissertation research is to develop a novel three-dimensional (3-D) wire bondless power module package for silicon carbide (SiC) power devices to achieve a low parasitic inductance and an improved thermal performance. A half-bridge module consisting of 900-V SiC MOSFETs is realized to minimize stray parasitic inductance as well as to provide both vertical and horizontal cooling paths to maximize heat dissipation. The proposed 3-D power module package was designed, simulated, fabricated and tested. In this module, low temperature co-fired ceramic (LTCC) substrate with vias is utilized as an interposer of which both top and bottom sides …

Nonmetallic Jet Impingement Thermal Management For Power Electronics Via Additive Manufacturing, Reece Whitt

Graduate Theses and Dissertations

The increase in energy demanded by transportation and energy sectors has necessitated highly efficient thermal management for reliable power electronics operations. Conventional cooling techniques are limited by their inability to target switching location hot spot temperatures, leading to non-uniform thermal gradients. These devices, such as cold plates and heat sinks, also utilize heavy metallic structures that can accentuate electromagnetic interferences generated by high voltage switching processes. This work proposes a non-metallic jet impingement cooler for more customized thermal management, while simultaneously reducing the harmful effects of electromagnetic interferences. Additive manufacturing is utilized to enable jet impingement zones to target individual …

Mission Profile Effects On Automotive Drivetrain Electronics Reliability: Modeling And Mitigation, Bakhtiyar Mohammad Nafis

Graduate Theses and Dissertations

The reliability of electronic devices is dependent upon the conditions to which they are subject. Temperature variations coupled with differences in thermal expansion between bonded materials results in thermomechanical stresses to build up, which can instigate failure in the interconnects or other critical regions. With the move towards electrification in the automotive industry, there is the increasingly important consideration of powertrain electronics reliability, the pertinent conditions being governed by the drive cycle or mission profile of the vehicle. The mission profile determines the power dissipated by the electronic devices, which determines the peak and mean temperature, temperature swing and the …