Engineering Commons^™

Transient Electrochemical Surface-Enhanced Raman Spectroscopic Study In Electrochemical Reduction Of P-Nitrothiophenol, Yun Ling, Jing Tang, Guo-Kun Liu, Cheng Zong

Journal of Electrochemistry

P-nitrothiophenol (PNTP) is one of the most common probe molecules studied by surface-enhanced Raman spectroscopy (SERS). The research in electrochemical reduction behavior of PNTP will help understanding the mechanism for the nitrobenzene reduction. In this paper, we used transient electrochemical surface-enhanced Raman spectroscopy (TEC-SERS) to study the SERS of PNTP with cyclic voltammetry and chronoamperometry on gold electrodes. The results show that the TEC-SERS provide a time resolution that equals the transient electrochemical methods, and we concluded that the reaction was so quick that we did not observe the spectral information of intermediate species described in the literatures with a …

Polyaniline Coated Hollow Sulfur Prepared Using Sublimate 2,4,6-Tri(Propan-2-Yl)-1,3,5-Trioxane As Template For Sulfur Electrode, Zhang-Feng Li, Xiao-Rui Wang, Wen-Sheng Tian, Jin-Ze Yang, Ping Zhang, Li-Ping Ma, Yang Chen, Xiao-Li Cui, Zhi-Yu Jiang

Journal of Electrochemistry

An advance method for preparing polyaniline-coated hollow sulfur material using sublimate material ADD(2,4,6-tri(propan-2-yl)-1,3,5-trioxane) as a template was developed for lithium-sulfur battery. At first, the smashed ADD particles were coated by a sulfur layer through the reaction of Na₂S₂O₃ with diluted HCl. Then polyaniline layer was coated again on the surface of sulfur layer through the reaction of aniline with (NH₄)₂S₂O₈. After being dried at 60 ^oC for 12 h, the ADD in such a composite evaporated totally, and resulted in the formation of polyaniline-coated hollow sulfur …

Study On Electro-Sorption Of Heavy Metals And Sulfamethoxazole On Activated Carbon Fibers, Wen-Jun Zhao, Bing-Xin Jia, Ya-Nan Zhang, Jiu-Nian Guan, Jiao Qu, Ying Lu

Journal of Electrochemistry

To study the optimal removal condition, adsorption mechanism and comparative analysis of the three typical cationic pollutants, i.e., Zn(II), anionic pollutant Cr(VI) and molecular pollutant sulfamethoxazole (SMX), using self-made upflowed electro-sorption device for adsorptions of above three pollutants by modified activated carbon fiber were researched. The activated carbon fiber (ACF) was modified by hydrochloric acid. The ACF morphology and structure before and after modification were characterized by SEM, BET and FTIR. The characterization results show that the modified ACF had fewer surface impurities than the modified surface and the gully is more obvious, the specific surface area was increased by …

Electrochemical Sensor Based On Magnetic Electrode Modified With Magnetic Molecularly Imprinted Nanoparticles Immobilized Hemoglobin For Determination Of Hydrogen Peroxide, Yang Yuan, Jia-Xin Wang, Yu-Hua Cao

Journal of Electrochemistry

In this work, the surface-imprinted technique was used to prepare magnetic hemoglobin (Hb) imprinted nanoparticles, using Fe₃O₄@SiO₂ NPs as the carrier, Hb as the template molecule, and tetraethyl orthosilicate (TEOS) as the imprinted polymer monomer. The nanoparticles had a core-shell structure, with magnetic Fe₃O₄ NPs as the core and Hb imprinted polymers as the shell. Therefore, Hb could be concentrated and fixed on the surface of the magnetic imprinted nanoparticles (MMIPs NPs). Furthermore, MMIPs NPs were immobilized with chitosan (CS) on the surface of a magnetic electrode to constitute Hb enzyme-like biosensor …

Ionic Liquid Assisted Synthesis Of Porous Carbons From Rice Husk For Supercapacitors, Han-Fang Zhang, Feng Wei, Jian Sun, Meng-Ying Jing, Xiao-Jun He

Journal of Electrochemistry

It is still a challenge to prepare carbon materials with high specific surface area at low cost from renewable resources. Herein, the authors report an efficient approach to synthesize porous carbons (PCs) from rice husk with ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF₆)) as a template and an activation agent. The as-made PCs featured the high specific surface area up to 1438 m²·g^-1. As electrodes for supercapacitors, PCs showed a high specific capacitance of 256 F·g^-1 at 0.05 A·g^-1 in 6 mol·L^-1 KOH aqueous electrolyte and a good rate performance of 211 F·g …

Morphology Controlled Preparations And Electrochemical Properties Of Znco2O4 Electrode Materials For Supercapacitors, Yue-Shen Zhou, Meng Li, Shuang Wu, Zhao-Lei Li, Yan-Min Gao

Journal of Electrochemistry

In this work, hydrothermal reaction and high temperature were used to grow ZnCo₂O₄ active materials on Ni foam. The crystal stuctures and surface morphlogies of four samples were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The electrochemical performances were characterized by cyclic voltammetry (CV)、galvanostatic charge/discharge (GCD) testing and electrochemical impedance spectroscopy (EIS) on an electrochemical station. It can be seen that active materials tended to form denser stuctures with an increasing amount of NH₄F in the solution system and four different morphologies of ZnCo₂O …

Zif-67-Derived Ag/Co-Embedded N-Enriched Mesoporous Carbon For Oxygen Reduction Reaction, Zheng-Ling Di, Jing Zhu, Lei Dai, Wei Meng, Yue-Hua Li, Zhang-Xing He, Ling Wang

Journal of Electrochemistry

Nitrogen-doped porous carbon materials are considered as one of the most promising catalysts for oxygen reduction reaction (ORR). Herein, in order to further improve the activity of the nitrogen-doped porous carbon, Ag/Co bimetal is embedded into nitrogendoped porous carbon to form Ag/Co-embedded nitrogen-doped porous carbon material (AgCo@NC). The AgCo@NC was derived by the wet impregnation of Ag+ into ZIF-67 precursor, followed by chemical reduction and a subsequent pyrolysis process under Ar atmosphere at different temperatures (500 ℃, 600 ℃, 700 ℃). The morphologic characterization shows that the Ag/Co nanoparticles were successfully embedded in the mesoporous carbon framework with abundant nitrogen …

Electrochemical Properties Of Sulfur In Different Carbon Support Materials, Bo Zhang, Jia Liu, Xiao-Chen Liu, De-Jun Li

Journal of Electrochemistry

In order to investigate the effect of carbon structure on electrochemical performance of sulfur/carbon composite in lithium-sulfur battery, in this paper, sublimation sulfur was incorporated into three types of carbon materials, namely, graphene, carbon black and porous carbon. The three sulfur/carbon composites were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and X-ray diffraction (XRD) techniques, and their electrochemical performances were also studied. The results showed that the sulfur/porous carbon composite offered an initial discharge capacity of 1623.2 mA·h·g^-1 and remained 845 mA·h·g^-1 after 100 cycles. Compared with graphene and carbon black, the mesopores and micropores in porous …

Optimal Allocation Of Energy Storage And Wind Generation In Power Distribution Systems, Carlos Mendoza

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

The advent of energy storage technologies applications for the electric power system gives new tools for planners to cope with the operation challenges that come from the integration of renewable generation in medium voltage networks. This work proposes and implements an optimization model for Battery Energy Storage System (BESS) and distributed generation allocation in radial distribution networks. The formulation aims to assist distribution system operators in the task of making decisions on energy storage investment, BESSs' operation, and distributed generation penetration's level to minimize electricity costs. The BESSs are required to participate in energy arbitrage and voltage control. In addition, …

Critical Radius Of Insulation, Maria N. Ambrose, Samuel J. Sayre, Travis W. Martin, Matt T. Sterling

Mechanical Engineering

The critical radius of insulation is a counterintuitive concept within the study of heat transfer. The theory states that adding insulation to a cylindrical or spherical object will increase the rate of heat loss rather than decrease it, if the radius (thickness) of the insulation is at its “critical” value. The Critical Radius of Insulation Senior Project is designed to demonstrate this phenomenon to Heat Transfer students via a portable apparatus. The concept will be demonstrated with a cylindrical object which is heated by way of a separate voltage source. Thermocouples will display the temperature of the cylinder while insulation …

Load Flow Analysis Of 138/69kv Substation Using Electrical Transient & Analysis Program (Etap), Vanessa Abadia Gomez

Electrical Engineering Undergraduate Honors Theses

This paper examines the load flow analysis of a high-voltage substation using ETAP, and explores options for improving the voltage profile of the system. This study yields critical information about the system, such as the voltage drop at each feeder, the voltage at each bus, as well as real and reactive power losses at the different branches and feeders. In this power flow examination, the system’s performance is evaluated for different operating conditions, so that control measurements can be applied if necessary. The experimental results are used for proposing a plan of using fixed and switched shunt capacitor banks to …

High Frequency Ltcc Based Planar Transformer, Adithya Venkatanarayanan

Graduate Theses and Dissertations

As we move towards high power and higher frequency related technology, conventional wire-wound magnetics have their own limitations which has led path to the development of planar based magnetic materials. Nowadays more planar magnetic technology has been employed because it is easier to fabricate them. The planar magnetic is a transformer or an inductor that replaces the wire-wound transformer or inductors which generally uses copper wires. One of the main reasons why we move to planar magnetic technology is its operation at higher frequency which provides higher power density. This study explains in detail about the design and fabrication of …

Pv Mppt Water Pump Controller, Jacob R. Lamkin

Electrical Engineering

The intention of this project is to create a low cost way to extract the maximum useful power from a PV module to power a water pump. This approach will yield maximum financial and technical accessibility for end users. The project was successful in powering a water pump from a PV module as desired, and the microcontroller driven control circuitry was capable of finding and maintaining operation at the maximum power point of the PV module. Due to the low performance of the buck converter used in this project, this approach was not as efficient as desired and would require …

Adaptive Boundary Control Using The Natural Switching Surfaces For Flyback Converters, Luciano Andres Garcia Rodriguez

Graduate Theses and Dissertations

The derivation and implementation of the natural switching surfaces (NSS) considering certain parametric uncertainties for a flyback converter operating in the boundary conduction mode (BCM) is the main focus of this paper. The NSS with nominal parameters presents many benefits for the control of nonlinear systems; for example, fast transient response under load-changing conditions. However, the performance worsens considerably when the converter actual parameters are different from the ones used in the design process. Therefore, a novel control strategy for NSS considering the effects of parameter uncertainties is proposed. This control law can estimate and adapt the control trajectories in …

Design And Optimization Of A High Power Density Silicon Carbide Traction Inverter, Tyler Adamson

Graduate Theses and Dissertations

This project was initiated with the goal of demonstrating a 3-phase silicon carbide based 150-kW 25 kW/L DC-AC power conversion unit capable of operation with coolant temperatures up to 90°C. The project goals were met and exceeded by first analyzing the established inverter topologies to find which one would yield the highest power density while still meeting electrical performance needs in the 150-kW range. Following topology selection, the smallest silicon carbide power module that met the electrical requirements of the system was found through experimental testing and simulation. After a power module selection was finalized, a DC link capacitor bank …

Evaluation And Analysis Of Null Convention Logic Circuits, John Davis Brady

Graduate Theses and Dissertations

Integrated circuit (IC) designers face many challenges in utilizing state-of-the-art technology nodes, such as the increased effects of process variation on timing analysis and heterogeneous multi-die architectures that span across multiple technologies while simultaneously increasing performance and decreasing power consumption. These challenges provide opportunity for utilization of asynchronous design paradigms due to their inherent flexibility and robustness.

While NULL Convention Logic (NCL) has been implemented in a variety of applications, current literature does not fully encompass the intricacies of NCL power performance across a variety of applications, technology nodes, circuit scale, and voltage scaling, thereby preventing further adoption and utilization …

E700xd Portable Doppler Radar Energy Systems Analysis, Brandon M. Bailey [*], Torrey J. Wagner, Jada Williams

Faculty Publications

Occurring in industrialized nations, inexpensive and abundantly available power is routinely taken for granted. However, energy resilience and to a lesser extent price are key concerns when considering potential solutions for disaster response, disaster relief, or military operations. The Department of Defense (DoD) currently uses a 5 kW generator to power the E700XD portable Doppler radar system when grid power is unavailable [1]. While the radar has an approximate power consumption of 2.5 kW, there is a potential for higher demand due to weather conditions [2]. This paper examines the cost of operating a currently installed generator, compared to the …

Fractional Order State Feedback Control For Improved Lateral Stability Of Semi-Autonomous Commercial Heavy Vehicles, Rasheed Mazen Abdulkader

Graduate Theses and Dissertations

With the growing development of autonomous and semi-autonomous large commercial heavy vehicles, the lateral stability control of articulated vehicles have caught the attention of researchers recently. Active vehicle front steering (AFS) can enhance the handling performance and stability of articulated vehicles for an emergency highway maneuver scenario. However, with large vehicles such tractor-trailers, the system becomes more complex to control and there is an increased occurrence of instabilities. This research investigates a new control scheme based on fractional calculus as a technique that ensures lateral stability of articulated large heavy vehicles during evasive highway maneuvering scenarios. The control method is …

Performance Enhancement And Characterization Of An Electromagnetic Railgun, Paul M. Gilles

Master's Theses

Collision with orbital debris poses a serious threat to spacecraft and astronauts. Hypervelocity impacts resulting from collisions mean that objects with a mass less than 1g can cause mission-ending damage to spacecraft. A means of shielding spacecraft against collisions is necessary. A means of testing candidate shielding methods for their efficacy in mitigating hypervelocity impacts is therefore also necessary. Cal Poly’s Electromagnetic Railgun was designed with the goal of creating a laboratory system capable of simulating hypervelocity (≥ 3 km/s) impacts. Due to several factors, the system was not previously capable of high-velocity (≥ 1 km/s) tests. A deficient projectile …

Demand-Side Load Management Using Single-Phase Residential Static Var Compensators, Muhammad Kamran Latif

Boise State University Theses and Dissertations

Distribution systems are going through a structural transformation from being radially-operated simple systems to becoming more complex networks to operate in the presence of the distributed energy resources (DERs) with significant levels of penetration. It is predicted that the share of electricity generation from DERs will keep increasing as the world is moving away from the power generation involving carbon-emission and towards cleaner energy sources such as solar, wind, and biofuels. However, the unstable behavior of the renewables resources presents challenges to the already existing distribution systems. One such problem is when the distribution feeder experience variable power supply due …

Transmission-Scale Battery Energy Storage Systems: A Systematic Literature Review, Kevin Marnell, Manasseh Obi, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

When the transmission capacity of an electrical system is insufficient to adequately serve customer demand, the transmission system is said to be experiencing congestion. More transmission lines can be built to increase capacity. However, transmission congestion typically only occurs during periods of peak demand, which occur just a few times per year; capitol-intensive investments in new transmission capacity address problems that occur infrequently. Alternative solutions to alleviated transmission congestion have been devised, including generation curtailment, demand response programs, and various remedial action schema. Though not currently a common solution, battery energy storage systems can also provide transmission congestion relief. Technological …

Novel Control Of Pv Solar Farms As Statcom (Pv-Statcom) For Frequency Control And Power Oscillation Damping, Mohammad Akbari Kelishadi

Electronic Thesis and Dissertation Repository

Frequency stability and low-frequency power oscillations are two major concerns in modern power systems. PV-STATCOM is a patented concept which enables PV inverters to provide STATCOM functions, during day and night, as well as real power modulation during daytime. This thesis aims to utilize PV-STATCOM capability effectively for enhancing frequency stability and power oscillations damping.

A novel, simultaneous real power-based Fast Frequency Response (FFR) and reactive power-based Power Oscillation Damping (POD) control is proposed for PV-STATCOMs. This control not only significantly reduces system under- and over-frequency deviations, but also uses the unutilized capacity of PV inverters to enhance damping of …

Isolated Single-Stage Power Electronic Building Blocks Using Medium Voltage Series-Stacked Wide-Bandgap Switches, Noureldeen Mohamed Elsayad

FIU Electronic Theses and Dissertations

The demand for efficient power conversion systems that can process the energy at high power and voltage levels is increasing every day. These systems are to be used in microgrid applications. Wide-bandgap semiconductor devices (i.e. Silicon Carbide (SiC) and Gallium Nitride (GaN) devices) are very promising candidates due to their lower conduction and switching losses compared to the state-of-the-art Silicon (Si) devices. The main challenge for these devices is that their breakdown voltages are relatively lower compared to their Si counterpart. In addition, the high frequency operation of the wide-bandgap devices are impeded in many cases by the magnetic core …

Split Dc Bus Converters For Power Electronic And Ac-Dc Microgrid Applications, Javad Khodabakhsh

Electronic Thesis and Dissertation Repository

Power electronic converters are used extensively for electrical power conversion in applications such as renewable energy systems, utility applications, and electric vehicles. Such converters are needed as it is rare for a source voltage to fit the needs of a load or a set of loads for any particular application. They consist of active semiconductor switches and passive components that are combined in circuit structures (topologies) that are operated with a control strategy. The focus of this thesis is on AC-DC and DC-DC converters and their applications in AC-DC microgrids.

AC-DC converters are typically two-stage converters that consist of a …

Performance Of Desiccant Enhanced Evaporative Cooling System Based On High-Low Control, Yi Chen, Huaxia Yan, Yimo Luo

Faculty of Science & Technology (THEi)

Desiccant enhanced evaporative cooling system is a sustainable air-conditioning (A/C) system which deals the latent load and sensible load separately by a dehumidifier and an evaporative cooler. A LDD-RIEC system consists of a liquid desiccant dehumidifier (LDD) and a regenerative indirect evaporative cooler (RIEC) were investigated. The LDD-RIEC system is characterized by low energy consumption compared with conventional mechanical cooling system, but the main shortcoming is the high dependency on ambient air conditions. To maintain stable indoor temperature, a control scheme is essential. However, very limited research work regarding control strategy can be found in open literatures. In this paper, …

Novel Night And Day Control Of Pv Solar Farm As Statcom (Pv-Statcom) For Critical Induction Motor Stabilization And Fidvr Alleviation, Sibin Mohan

Electronic Thesis and Dissertation Repository

Induction motors are globally used in several critical operations such as petrochemicals, mining, process control, etc., where their shutdown during faults causes significant financial loss. System faults can also lead to Fault Induced Delayed Voltage Recovery (FIDVR) causing service disruptions. Dynamic reactive power compensators such as SVC and STATCOM are conventionally employed to mitigate these issues, however, these are very expensive.

PV solar plants are growing at unprecedented rate globally and are likely to be installed near such critical motors. This thesis presents several novel applications of a patented technology of utilizing PV solar plants, both during night and day, …

Data Analytics And Machine Learning To Enhance The Operational Visibility And Situation Awareness Of Smart Grid High Penetration Photovoltaic Systems, Aditya Sundararajan

FIU Electronic Theses and Dissertations

Electric utilities have limited operational visibility and situation awareness over grid-tied distributed photovoltaic systems (PV). This will pose a risk to grid stability when the PV penetration into a given feeder exceeds 60% of its peak or minimum daytime load. Third-party service providers offer only real-time monitoring but not accurate insights into system performance and prediction of productions. PV systems also increase the attack surface of distribution networks since they are not under the direct supervision and control of the utility security analysts.

Six key objectives were successfully achieved to enhance PV operational visibility and situation awareness: (1) conceptual cybersecurity …

Edge Iot Driven Framework For Experimental Investigation And Computational Modeling Of Integrated Food, Energy, And Water System, Yemeserach Taye Mekonnen

FIU Electronic Theses and Dissertations

As the global population soars from today’s 7.3 billion to an estimated 10 billion by 2050, the demand for Food, Energy, and Water (FEW) resources is expected to more than double. Such a sharp increase in demand for FEW resources will undoubtedly be one of the biggest global challenges. The management of food, energy, water for smart, sustainable cities involves a multi-scale problem. The interactions of these three dynamic infrastructures require a robust mathematical framework for analysis. Two critical solutions for this challenge are focused on technology innovation on systems that integrate food-energy-water and computational models that can quantify the …

Novel Pv Solar Farm Control As Statcom (Pv-Statcom) For Ssr Mitigation In Synchronous Generators And Wind Farms, Reza Salehi Sharafdarkolaee

Electronic Thesis and Dissertation Repository

Transmission lines across the world are extensively compensated by series capacitors to increase their power transfer capacity. However, series compensation can potentially cause subsynchronous resonance (SSR) which can lead to significant damage in shafts of synchronous generators and wind farms. Dynamic reactive power compensators such as STATCOM and SVCs are typically used for mitigation of SSR, but these are quite expensive.

Large scale PV solar farms are growing at a very rapid rate across the world. It is quite likely that they may get installed near synchronous generators or wind farms which are directly or indirectly interfaced with series compensated …

Optimal Combinations Of Utility Level Renewable Generators For A Net Zero Energy Microgrid Considering Different Utility Charge Rates, Evan S. Jones, Huangjie Gong, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

High initial investment and the intermittent nature of resources are major challenges for large scale renewable generation. The size of photovoltaic (PV) and wind turbine (WT) farms in the microgrid needs optimized to avoid curtailment and to efficiently meet the demand of a power system. Battery energy storage systems (BESSs) may also be used to improve flexibility. This paper explores the optimal sizing for PV and wind generators, as well as a BESS at the utility level for a large grid-connected net zero energy (NZE) hybrid microgrid considering characteristics such as initial investment, levelized cost of energy (LCOE), operating costs, …