Engineering Commons^™

Low Power Fft Processor Design Considerations For Ofdm Communications, David Layne Rushforth

UNLV Theses, Dissertations, Professional Papers, and Capstones

Today's emerging communication technologies require fast processing as well as efficient use of resources. This project specifically addresses the power-efficient design of an FFT processor as it relates to OFDM communications such as cognitive radio. The Fast Fourier Transform (FFT) processor is what enables the efficient modulation in OFDM. As the FFT processor is the most computationally intensive component in OFDM communication, the power efficiency improvement of this component can have great impacts on the overall system. These impacts are significant considering the number of mobile and remote communication devices that rely on limited battery-powered operation. This project explores current …

Anti-Islanding Schemes For Machine-Based Distributed Generation, Temesgen Tadegegn

UNLV Theses, Dissertations, Professional Papers, and Capstones

The most common method of detecting the islanding in a machine-based distributed generator (DG) is to establish an under/over frequency and under/over voltage window within which a synchronous DG is allowed to operate. When such a DG is islanded from the utility system, the frequency or voltage will quickly move outside the operating window if there is a sufficient difference between the local load and DG power generation level. However, there is a possibility that the system voltage and frequency will be maintained within the specified limits following loss of the grid in cases where the load and generator are …

Evaluation Of Rapid Electric Battery Charging Techniques, Ronald Baroody

UNLV Theses, Dissertations, Professional Papers, and Capstones

Battery powered electric vehicles are gaining popularity worldwide. This is trend is driven by several factors including the need to reduce air and noise pollution, and dependence on fossil fuels. The main drawback of today's electric vehicle is its limited range, and the long time duration that is required to charge the electric batteries. This thesis addresses the latter problem.

In recent years, significant progress (through research and development) has been made to accelerate the charging time of the electric vehicle batteries through pulse charging rather than supplying continuous current and/or voltage. Some patented fast charging techniques demonstrated reduced charging …

Parametric Study Of Efficiency Measures For Home Energy Conservation In Las Vegas, Nevada, Todd M. France

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pulte Homes, a production home builder and community developer partnering with the U.S. Department of Energy's Building America program, has collaborated with the Center for Energy Research at the University of Nevada, Las Vegas and NV Energy, the local electric utility, on an energy conservation project in the Las Vegas Valley.

This study entails four model homes at a new development in the Summerlin community of Las Vegas, Nevada, named Villa Trieste. The home models, ranging in floor plan area from 1,487 to 1,777 square feet, have been constructed under the Environments for Living program and are LEED (Leadership in …

Spectroscopic Investigation Of Palladium-Copper Bimetallic Systems For Pem Fuel Cell Catalysts, Timo Hofmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the main barriers to commercialization of polymer electrolyte membrane fuel cells systems is cost, which is largely due to the need of platinum (Pt)-containing catalysts. In this thesis we investigate bimetallic systems consisting of a base metal (copper) and a noble metal (palladium) that, as an alloy on the nanoscale, mimic the electronic properties that make Pt desirable as a catalyst.

We present a detailed investigation of the electronic structure of carbon-supported Pd/Cu nanoparticle catalysts, model bilayer thin film systems, alloys, and various metal reference samples. We have investigated the valence band structure of the catalysts using a …

Islanded Operation Of A Distribution Feeder With Distributed Generation, Chandu Venu

UNLV Theses, Dissertations, Professional Papers, and Capstones

A distribution system that is equipped with distributed generators, such as roof-mounted photovoltaic systems, can operate as a microgrid (i.e., separated from the grid) under some specific conditions. A key feature of a microgrid is its ability to separate and isolate itself from the utility seamlessly with little or no disruption to the loads within the microgrid. Then, when the utility grid returns to normal, the microgrid automatically resynchronizes and reconnects itself to the grid, in an equally seamless manner. This thesis addresses the conditions necessary for proper microgrid operation: these include local generation-load mismatch, local energy storage, load switching, …