Power and Energy Commons^™

Effects Of Graphene On Electrochemical Behaviors Of Ni(Oh)2 As Supercapacitor Material, Zhen-Zhen Zhao, Wen-Bin Ni, Neng-Yue Gao, Hong-Bo Wang, Jian-Wei Zhao

Journal of Electrochemistry

The enhanced electrochemical properties of Ni(OH)₂ by the oxidation defected graphene were studied by both experimental method and theoretical calculation. The composite material of nano-Ni(OH)₂/graphene was prepared by potentiostatic deposition on the graphene substrate. Observed by TEM, the Ni(OH)₂ nanoparticles were well dispersed on the graphene substrate with the diameter of 5.0±0.5 nm. The capacitance of the system measured by the electrochemical test was 1928 F·g^-1. As indicated by the theoretical calculations, the composite material becomes conductive since Ni(OH)₂ is combined with surface functional groups of the graphene through the strong chemical interaction. …

Synthesis Of Limnpo4/C Used As Cathode Material For Lithium Ion Batteries, Xin Yang, Xue-Wu Liu, Gui-Chang Liu, Zhi-Cong Shi, Xin Li, Guo-Hua Chen

Journal of Electrochemistry

The LiMnPO₄/C composites were prepared using a solid-state reaction with addition of the resorcinol formaldehyde resin as the carbon source. The effects of reaction temperature and time on the crystal structure, morphology and electrochemical properties of the LiMnPO₄/C composites were investigated. The results show that the best performance was achieved with the LiMnPO₄/C composites synthesized at 600 ^oC for 12 h which had the particle sizes about 100~200 nm. The initial discharge capacities were 121.6 mAh·g^-1 at 0.02C, 110 mAh·g^-1 at 0.1C and more than 60 mAh·g^-1 at 1C. An …

Synthesis And Electrochemical Behaviors Of Li2Coxmn1-XSio4 As A Cathode Material For Lithium-Ion Batteries, Lin Wang, Dong-Ping Lv, Yong Yang

Journal of Electrochemistry

We have successfully synthesized Li₂Co_xMn_1-xSiO₄/C (x=0, 0.1, 0.3, 0.5, 1)/C composites using hydrothermal assisted sol-gel process and ball-milling method. The results of X-ray diffraction show that the solid solutions of Li₂Co_xMn_1-xSiO₄ can be achieved when x≤0.3. The initial capacities increase from 70 mAh·g^-1 of Li₂MnSiO₄/C to 105 mAh·g^-1 of Li₂Co_0.3Mn_0.7SiO₄/C. Cyclic Voltammetry (CV) curves show that the replacement of Mn with Co can reduce the electrochemical polarization, making the insertion-extraction reaction …

Electrelectrochemical Performances Of C-Coating And Co-Doping Lifepo4, Ying Bai, Jue-Ming Yang, Chun-Bo Qing, Wei-Feng Zhang

Journal of Electrochemistry

Phospho-olivine LiFePO₄ cathode materials were prepared by hydrothermal reaction at 200 ^oC. Sucrose was added as C-coating resource and Co was doped into the crystal lattice of LiFePO₄. In order to investigate the improvements in the electrochemical properties of Co-doped LiFePO₄, three samples, LiFePO₄, C-coated LiFePO₄ and C-coating-Co-doped LiFePO₄, were synthesized under the same preparation conditions. Charge/discharge studies reveal that the Co-doped LiFePO₄/C composite annealed at 400 ^oC exhibits marked improvement of specific capacity by diminishing the particle sizes and enhancement in the degree of crystallinity. …

Experimental And Numerical Investigations Of Tubular-Shaped Direct Methanol Fuel Cells (Dmfcs), Travis R. Ward

Master's Theses

This study focuses on both the numerical and experimental investigations of the novel, passively operated, tubular-shaped, Direct Methanol Fuel Cell (DMFC) as an alternative geometry to the traditional planar-shaped fuel cell. The benefit of the tubular geometry compared to the planar geometry is the higher instantaneous volumetric power density provided by the larger active area, which could be beneficial in applications that require a high instantaneous power while occupying a small volume. First, a two-dimensional, two-phase, non-isothermal model was developed to investigate the steady-state performance and design characteristics of a tubular-shaped, passive DMFC. It was found that a higher ambient …

Morphology Changes In Pcpdtbt:Pcbm And P3ht:Pcpdtbt:Pcbm And Its Effect On Polymer Solar Cell Performance, Galen David Cauble

Physics

Polymer solar cell morphology is sensitive to both heat and time. By thermally annealing polymer solar cells the morphology of the devices can be altered causing immediate changes in device performance. Blending PCPDTBT:PCBM with P3HT:PCPDTBT combines the absorption characteristics of each to create a more even absorption spectrum. Subjecting PCPDTBT:PCBM, and P3HT:PCPDTBT:PCBM polymer solar cells to thermal annealing as well as recording device performance through time has shown that P3HT:PCPDTBT:PCBM devices react positively to thermal annealing (increasing from 0.8% to 1.4%) while PCPDTBT:PCBM devices have varied reactions. Furthermore, the P3HT:PCPDTBT:PCBM devices have achieved efficiencies of 1.6% in AM 1.5 compared …

Enhancing The Performance Of Building Integrated Photovoltaics, Brian Norton, Philip C. Eames, Tapas K. Mallick, Ming Jun Huang, Sarah J. Mccormack, Jayanta D. Mondol, Yigzaw G. Yohanis

Articles

Recent research in Building Integrated Photovoltaics (BIPV) is reviewed with the emphases on a range of key systems whose improvement would be likely to lead to improved solar energy conversion efficiency and/or economic viability. These include invertors, concentrators and thermal management systems. Advances in techniques for specific aspects of systems design, installation and operation are also discussed.

Constant Conduction Angle Experimental Generation For Rf Power Amplifiers, Michael Spahn

Electrical Engineering

As the demand for more devices to become wireless increases, there is a need for linear, efficient monolithic power amplifiers to deal with the variations in modulation of signals. With partial support from Cal Poly C3RP Grant #52268, this paper explains the implementation of and analyzes a circuit that actively biases a bipolar transistor to operate as a Class C amplifier. The Class C amplifier can maintain constant conduction angle over a range of output powers by using a Class B amplifier to force a scaled DC current vs. input magnitude curve on to a Class C amplifier. The knee …

Wireless Passive Power Transfer Using Wire Antennas, Sheng Da Zhang

Electrical Engineering

This project tests and analyzes the efficiency of directional and omnidirectional antennas in wireless power transfer for charging. The project demonstrates the steps of construction and properties of dipole, monopole, and Yagi Uda antennas. A low power high frequency DC rectifier circuit converts the received RF power from the antenna and stored it as DC voltage on a capacitor. The receiver circuit also estimates the power received by the antenna. Wireless RF power transmission proves to be inefficient for short distances. The best efficiencies of the antennas were under 50% even at 0.1meter. The near field attenuation starts at around …

140 New Montgomery Power Distribution Design, Stephen Shaffer

Electrical Engineering

The Power Distribution Design for a high-rise building requires a great deal of coordination and design from the structural, electrical, mechanical, telecommunication, and PG&E engineers. This report will cover how I was able to coordinate and design the power distribution system for 140 New Montgomery, a 28 story building located in San Francisco. Furthermore, this report will cover the steps taken in the future to ensure a smooth transition from the schematic design phase to the construction document phase.

Benefits Of Near-Term Cloud Location Forecasting For Large Solar Pv, Timothy Robert Rudd

Master's Theses

As the ‘green’ energy movement continues to gain momentum, photovoltaic generation is becoming an increasingly popular source for new power generation. The primary focus of this paper is to demonstrate the benefits of close-to real-time cloud sensing for Photovoltaic generation. In order to benefit from this close-to real-time data, a source of cloud cover information is necessary. This paper looks into the potential of point insolation sensors to determine overhead cloud coverage. A look into design considerations and economic challenges of implementing such a monitoring system is included. The benefits of cloud location sensing are examined using computer simulations to …

Accurate Circuit Model For Predicting The Performance Of Lead-Acid Agm Batteries, Wenxin Peng

UNLV Theses, Dissertations, Professional Papers, and Capstones

Energy storage technologies are becoming of great importance in many modern electrical systems. In particular, electrochemical batteries are rapidly gaining wide-spread application in transportation systems as well as in the electric utility sector, where they provide a means to convert non-dispatchable renewable resources into dispatchable generation sources. Hence, accurate battery models are needed during the design stage of such systems to forecast future performance.

A variety of models with a varying degree of complexity and accuracy currently exist that predict battery behavior. In the proposed paper, an existing battery model is modified to account for some battery irregularities while maintaining …

Improving The Efficiency Of Organic Solar Cells By Varying The Material Concentration In The Photoactive Layer, Kevin Anthony Latimer

Electrical & Computer Engineering Theses & Dissertations

Polymer-fullerene bulk heterojunction solar cells have been a rapidly improving technology over the past decade. To further improve the relatively low energy conversion efficiencies of these solar cells, several modifications need to be made to the overall device structure. Emerging technologies include cells that are fabricated with interfacial layers to facilitate charge transport, and tandem structures are being introduced to harness the absorption spectrum of polymers with varying bandgap energies.

When new structures are implemented, each layer of the cell must be optimized in order for the entire device to function efficiently. The most volatile layer of these devices is …

Characterizing Cyclostationary Features Of Digital Modulated Signals With Empirical Measurements Using Spectral Correlation Function, Mujun Song

Theses and Dissertations

Signal detection is widely used in many applications. Some examples include Cognitive Radio (CR) and military intelligence. CRs use signal detection to sense spectral occupancy. Without guaranteed signal detection, a CR cannot reliably perform its role. Similarly, signal detection is the first step for garnering an opponent's information. Wireless signal detection can be performed using many different techniques. Some of the most popular include matched filters, energy detectors (which use measurements such as the Power Spectral Density (PSD) of the signal), and Cyclostationary Feature Detectors (CFD). Among these techniques, CFD can be viewed as a compromise technique, in that it …

Design, Fabrication, And Testing Of An Electromagnetic Rail Gun For The Repeated Testing And Simulation Of Orbital Debris Impacts, Jeff Maniglia, Jordan Smiroldo, Alex Westfall, Guy Zohar

Aerospace Engineering

An Electromagnetic Railgun (EMRG) was designed, built, and tested, capable of firing a projectile a 1 gram projectile at 650 m/s muzzle velocity. The EMRG utilizes an injector, a high voltage power supply, a capacitor bank, inductors and rails. The injector fires 2300 psig Nitrogen gas into the system to provide an initial velocity. The high voltage power supply charges the capacitor bank. The capacitor bank discharges the electric potential built up through the projectile while inside the rails in order to create the EMRG’s force. The inductors are used to pulse form the capacitor bank in order to get …

Programmable Household Led Light Fixture, Jordan Locano

Electrical Engineering

This report details the development and construction of a LED light fixture to be used for household lighting. This document details background information, design ideas, project specifications, production, assembly, testing, and conclusions involved with this project. The goals of this project is to design and build a cost-effective replacement for traditional room lighting that can perform better and last longer than traditional methods.

Solar Powered Electric Clothes Dryer, Roger Mai, Alan Swe

Electrical Engineering

Appliances that consume the most energy in a household usually involve heating, and an electric clothes dryer is one such appliance, consuming up to 4KW of power. The most environmentally friendly way is to hang clothes outside to dry, a natural solar and wind powered method, but unfortunately most people are unable to do so as some neighborhood communities do not allow the hanging of laundry outside as it is regarded as “unsightly”, for example. This project aims to provide an alternate solution to the wall-powered electric clothes dryer by designing one which operates entirely off the grid.

Bicycle-Powered Ac Generator, Andrew Austin

Electrical Engineering

The purpose of this senior project is to design, build, and be able to present a mechanism that will produce AC power using the mechanical energy produced by a person pedaling a standard bicycle. Also, I would like to be able to show the user and the audience the advantage of using compact fluorescent bulbs, and in doing so, make them more conscience of energy-saving products. To do this, I must present a stand that can support a bicycle with a rider, a way to convert the wheel’s motion to DC power, to convert that DC power to usable AC …

Portable Solar Desalination System, Genaro Sanchez, Alan Galarza, Erick Del Real

Electrical Engineering

Clean water and reliable energy can be difficult to obtain in remote locations such as desert villages, secluded islands, and other places where no fresh water can be found. The primary goal for this project is address these problems by implementing a portable desalinization plant system that is to be powered by solar energy PV system as the main energy source.

Sick Laser Scanner Power Supply For Use With A Yamaha Rmax Uav, Elliot Due

Electrical Engineering

No abstract provided.