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Building Services Engineering

No abstract provided.

Investigation Of Two-Phase Air Water Flow Using Annubar, Ehab Fouad Shoukry

Archived Theses and Dissertations

No abstract provided.

Sinusoidal-Gaussian Beams In Complex Optical Systems, Lee W. Casperson, Dennis G. Hall, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

Sinusoidal-Gaussian beam solutions are derived for the propagation of electromagnetic waves in free space and in media having at most quadratic transverse variations of the index of refraction and the gain or loss. The resulting expressions are also valid for propagation through other real and complex lens elements and systems that can be represented in terms of complex beam matrices. The solutions are in the form of sinusoidal functions of complex argument times a conventional Gaussian beam factor. In the limit of large Gaussian beam size, the sine and cosine factors of the beams are dominant and reduce to the …

Evaluation Of The Et2000 Guardrail End Treatment, Kenneth R. Agent, Jerry G. Pigman, Darrell Mcalister, Tim Gatewood

Kentucky Transportation Center Research Report

The objectives of this study were to monitor and report the performance of the ET2000 guardrail end treatment design in traffic accidents. Data for a total of 34 collisions involving the ET2000 were identified. In most cases, an accident report was obtained and the damaged guardrail was inspected. The involved vehicle was inspected when available. Proper or improper performance of end treatments in the collisions were judged based on whether it performed as designed.

Field performance of the ET2000, as documented in traffic accidents, shows that, considering all the impacts, this end treatment has performed properly. In several instances the …

Pseudogap And Incommensurate Magnetic Fluctuations In Yba2cu3o6.6, Pengcheng Dai, Herbert A. Mook, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Unpolarized inelastic neutron scattering is used to study the temperature and wave vector dependence of the dynamical magnetic susceptibility X"(q,w) of a well-characterized single-crystal YBa₂Cu₃O_6.6 (Tc = 62.7 K). We find that a pseudogap opens in the spin-fluctuation spectrum at temperatures well above T_c. We speculate that the appearance of the low-frequency incommensurate fluctuations is associated with the opening of the pseudogap. To within the error of the measurements, a gap in the spin-fluctuation spectrum is found in the superconducting state.

Absolute Measurements Of The High-Frequency Magnetic Dynamics In Hihg-Tc Superconductors, Stephen M. Hayden, Gabriel Aeppli, Pengcheng Dai, Herbert A. Mook, Toby G. Perring, S-W Cheong, Zachary Fisk, Fatih Dogan, Thomas E. Mason

Materials Science and Engineering Faculty Research & Creative Works

We review recent measurements of the high-frequency dynamic magnetic susceptibility in the high-T~ superconducting systems La_2-xSr_xCuO₄ and YBa₂Cu₃O_6+x. Experiments were performed using the chopper spectrometers HET and MARI at the ISIS spallation source. We have placed our measurements on an absolute intensity scale; this allows systematic trends to be seen and comparisons with theory to be made. We find that the insulating S = ½ antiferromagnetic parent compounds show a dramatic renormalization of the spin wave intensity. The effect of doping on the response is to cause broadenings in …

Strategic Planning For Activation And Operation Of The North Central Superpave Center (Ncsc): Interim Report, Jan Olek, Rebecca Mcdaniel

JTRP Technical Reports

The North Central Superpave Center (NCSC) was established to serve the needs of the states and industry in ten states and two Canadian provinces as they implement the Superpave system. Accomplishing this goal requires the cooperation and active support of a number of people and organizations. Organizational and operational issues related to infrastructure, personnel, equipment and finances also needed to be resolved. This project was designed to address those issues, develop a comprehensive strategic plan and initiate a number of activities of the North Central Superpave Center (NCSC).

This report summarizes the efforts in the following areas:

1 . Personnel …

Real-Time And On-Line Near-Field Microwave Inspection Of Surface Defects In Rolled Steel, R. Zoughi, Christian J. Huber, Nasser N. Qaddoumi, Emarit Ranu, Vladimir Otashevich, Radin Mirshahi, Stoyan I. Ganchev, Thomas Johnson

Electrical and Computer Engineering Faculty Research & Creative Works

The potential and limitations of near-field microwave inspection techniques for detecting various surface defects in rolled steel have been investigated. The focus of this study has been to investigate this potential for tin mill products containing gross and subtle defects including steel induced defects, roll marks, holes, scratches and gouges.

Experimental Investigation Of Water Spray Cooling Characteristics Of A Solid Heated Surface, Rainer F. Ponzel

Masters Theses

Water spray cooling characteristics of a solid heated surface were investigated to better understand the physical phenomenon of nucleate boiling heat transfer for full cone sprays. An experimental test loop was developed to conduct the spray cooling experiments. A uniform heat flux condition was assumed, and the liquid flow rate and nozzle orifice diameter were selected as the main variables. Two water temperatures were chosen to perform the study. Saturated water spray was utilized to measure the wall superheat temperature. Subcooled water spray was applied to investigate the effect of water spray in the single-phase regime.

Experiments conducted using the …

Analog Hardware Implementation Of Adaptive Filter Structures, Jui Kuo Juan, J. G. Harris, J. C. Principe

Electrical and Computer Engineering Faculty Research & Creative Works

We have implemented a four-tap adaptive filter in a continuous-time analog VLSI circuit. Since an ideal delay is impossible to implement in continuous-time hardware, we implemented the delay line as a cascade of low-pass filters (called the Gamma filter). Since many years of research in our lab has shown that the Gamma filter outperforms the delay line for a wide range of applications, the Gamma filter should not be considered merely a crude approximation of the ideal delay line. We show measured results from an analog chip that solves the problem of system identification-identifying an unknown linear circuit from its …

Recycling Of Composite Material, Shereen Hassanein El Attawi

Archived Theses and Dissertations

No abstract provided.

Preparation Of High Rate Discharge Foamed Ni-Cd Battery, Yuming Wang, Jinsheng Chen

Journal of Electrochemistry

A novel device of SC type foamed NiCd battery is presented, in which, the innerresistance of battery is appeared to be reduced, and the electrode performance is gained to very improved, and so, this battery can be suited to using of the powerdrive pistol drill.

Advances In Solid Polymer Electrolytes, Liming Ding, Shaojun Dong, Erkang Wang

Journal of Electrochemistry

The formation, classification, applications and ion-transport mechanism studies of solid polymer electrolytes were reviewed. While the recent SPE reports on the preparation of novel materials, the full structure determinations of PEO/salt complexes, the exploration of ion-transport mechanism and the applications in electrochemical devices being introduced, some prospects on the future SPE research were suggested.

Li/Α-Sn(Hpo4)2 Cell And Its Reaction Mechanism, Yuan Lin, Runliang Cai, Haoqing Wu

Journal of Electrochemistry

The discharge mechanism of Li/α-Sn(HPO₄)₂ cell has been investigated by means of X-ray diffraction, XPS and cyclic voltammetry methodes. It has been shown that the electrochemical intercalation reation exists in the cathode material. There is a new phase after some degree of intercalation. With potential step and galvanostatic techniques, the chemical diffusion cofficients of Li⁺ in Li_xSn(HPO₄)₂ is estimated to be 10^-12～10^-13 cm²·s^-1.

Mechanism Of Electrodeposition Of Cu/Co Multilayer Thin Films, Jiangyun Xue, Jixun Wu, Dejun Yang

Journal of Electrochemistry

The mechanism of electrodeposition of Cu/Co multilayer thin films has been studied by means of potentodynamic sweep, cyclic voltammetry sweep and AC impendance. The results indicated that the copper deposition is mass transfer controlled process and the cobalt deposition is related to the absorbed intermediate species such as Co(OH)_ads. The cobalt ions first form Co(OH)_ads, then was deoxygenated to cobalt on the electrode surface.

The Effect Of Solution Composition On The Corrosion Behavior Of Electrodeposited Zinc Powder, Qingwen Li, Qin Yang, Xi Xia

Journal of Electrochemistry

Zinc powder as a widely anode material can be electrowon from ZnCl₂ or ZnO+KOH media. The properties of zinc powder are likely to be modified with electrolytic conditions such as the composition of bath solution, electrolysis manner, current density and additives etc.. In this paper, we have discussed the effect of the compositions of bath solution on the microstructure and corrosion resistance of zinc powder.

The Activity Of Alloy Cu-Ni Electrode In Electroreduction Of Aromatic Nitro-Compounds, Chunan Ma, Shaoping Tong, Xiaojun Cheng, Hui Wang

Journal of Electrochemistry

Cu-Ni alloy on the basis of copper at different ratio Cu/Ni are prepared by codepostion. The cathode activtiy of film are studied by steady-state polarization for electroreduction nitro-benzene (NB) and 1,5-dinitroanthraquinone (1,5-DNA) to p-aminophenol and 1,5-diamino-4,8-dihydroanthraquinone respectly. The results show that the alloy cathodes at different ratio Cu/Ni have different exchange current density (i^o) and apparent activition energy (E_A). The alloy (CN-30) has maximal i^o and minimal E_A by codeposition at the following conditions: electrolyte: 0.05 mol/L CuSO₄·5H₂O+0.6 mol/L NiSO₄·6H₂O+0.25 mol/L Na₃Cit·2H₂O; …

Photoluminescence Of Photoelectrochemically Etched N+-Si, Guozheng Li, Chengqian Zhang, Xiumei Yang

Journal of Electrochemistry

PS layer on n⁺-Si with (111) orientation prepered by means of photoelectrochemically etched has photo-luminescent (PL) ability like PS layer on usual n-Si. The data of PL spectra and quenching are given.

Study On The Oxygen Electrodes Of Alkaline Fuel Cells Effect Of Dopant On The Activity Of Ag/C Catalyst, Jiawei Teng, Linhua Jin, Luncheng Tang

Journal of Electrochemistry

A new kind of nonnoble catalyst for the oxygen electrodes of Alkaline Fuel Cells was investigated. The AgNiBiHg/C catalyst, which was prepared by chemical reduction, was active for the cathodic reduction of oxygen in alkaline fuel cells. It was found that the catalytic activity was improved by adding Ni, Bi, Hg to Ag/C catalyst, and the maximum activity was observed at Ag50%-Ni2%-Bi3%-Hg3%-C42%(wt%). XRD inconjunction with SEM indicated that the crystalline silver turned into amorphous in the presence of doping agents and the grain size of silver was reduced. No dramatic deactivation of the catalyst occured after 5200 hours of service.

Development Of A New Type Ni-S Evolution Hydrogen Electrode For Water Electrolysis, Xiaoyou Yuan, Jinyu Wang

Journal of Electrochemistry

A new type evolution hydrogen electrode NiS(N) has been made from nickel plating electrode in NiSO₄CS(NH₂)₂ bath by electrodeposition. It is analyzed by SEM and X-ray energy spectrum. The NiS(N) electrode is different from the NiS(O) electrode (which is used in plant at present time) in surface metallograph configuration and surfer content. The results of measurement polarization curves and water electrolysis 480 hours at 5 000 A·m^-2 show that the evolution hydrogen overpotential of NiS(N) electrode is decreased at least 160 mV relative to NiS(O) electrode and the stablisum of NiS(N) electrode is better …

Molten Carbonate Fuel Cell Materials And Technology, Naichao Li, Baolian Yi

Journal of Electrochemistry

Molten Carbonate Fuel Cell materials are reviewed, and the technology of Molten Carbonate Fuel Cell are discussed.

Study On Perchlorate Produced By Electrolysis With Oxygen Cathode, Zhigang Shao, Baolian Yi, Naichao Li, Ming Han

Journal of Electrochemistry

A new method of measuring the flow capacity of cell gas in the perchlorate cell process equipped with an oxygen cathode is applided to investigate the influence of changes in the concentration of solution (chloride, chlorate, perchlorate and metal ion) and changes in the operation parameters (current density, temperature and pH) on perchlorate current efficiency. The main abstacle that the oxygen cathode is used in the perchlorate cell process is put forward and a method is provided to resolve it.

The Effect Of Bismuth On Microstructure Of The Cathodic Copper Deposition Of Copper Electrorefining, Daorong Lu, Jianxing Lin

Journal of Electrochemistry

The electrocrystal formation, crystal orientation and the chemical composition of the cathodic copper deposition in the presence of Bi³⁺ in the electrolyte of acidified CuSO₄ are studies by scanning electron microscopy, X-ray diffraction, atomic absorption and EDAM. The results indicate that the Bi could′t deposit on cathode when copper electrolysed at common current density i=200 A·mol/L^-2 and t=60 ℃. Bi³⁺ scarcely effected on the crystal orientation (220) of copper deposition. High concentration Bi³⁺ in the electrolyte promoted (220) growth and inhibited the other crystal orientation growth. Bi³⁺ effected on electrocrystal formation and the cell …

Energy Needs During Disasters: Workshop Summary Report, Florida Solar Energy Center, Gerard Ventre

FSEC Energy Research Center®

When natural disasters, such as hurricanes, earthquakes and floods, occur, thousands of people can be left without homes, electrical power, communications, potable water, and food storage capabilities. Adequate electrical power is imperative for both disaster relief operations and community rebuilding. However, the disaster may have disrupted the commercial power supply to a community, requiring disaster relief agencies to rely on alternative sources of power. Photovoltaic-powered equipment provides electrical power which is renewable, quiet, and safe, and which can be used for many essentials of disaster relief efforts, such as refrigeration, communications and lighting. However, at present, photovoltaic (PV) technology is …

An Analysis Of Current Interruption Upon The Behavior Of Light Bulb Filament During Initial Aircraft Impact In Support Of Aircraft Accident Investigations, Daniel J. Larow

Master's Theses - Daytona Beach

The purpose of analyzing annunciator panels, warning, and indicator lamps is to determine the state ("on" or "off") of each light bulb immediately before the impact. Determination of the state of lamps may help investigators determine the probable cause of the accident. The information gained from the lamp's filaments may be used to infer the aircraft's operational parameters prior to impact and to a qualitative appreciation of the severity of the accident. It is generally agreed that upon impact the filament of an unlit bulb will fracture without deformation and the filament of a lit bulb will display plastic deformation …

Tractor Test Museum Commttee Minutes November 19th, 1997, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Update on Roof Progress Big Red Club State Fair Project

Pv Powering A Weather Station For Severe Weather, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

A natural disaster, such as Hurricane Andrew, destroys thousands of homes and businesses. The destruction from this storm left thousands of people without communications, potable water, and electric power. This prompted the Florida Solar Energy Center to study the application of solar electric power for use in disasters.

During this same period, volunteers at the Tropical Prediction Center at the National Hurricane Center (NHC) and the Miami Office of the National Weather Service (NWS) were working to increase the quantity and quality of observations received from home weather stations.

Many weather data collecting stations are at remote sites, which are …

Infrared Optical Properties Of Mixed-Phase Thin Films Studied By Spectroscopic Ellipsometry Using Boron Nitride As An Example, Mathias Schubert, B. Rheinlander, E. Franke, H. Neumann, T. E. Tiwald, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

We present a microstructure-dependent anisotropic infrared-optical dielectric function model for mixed-phase polycrystalline material from which we derive the transverse and longitudinal-optical modes observable in thin films. Infrared ellipsometry over the wavelength range from 700 to 3000 cm^-1 is then used to determine the phase and microstructure of polycrystalline and multilayered hexagonal and cubic boron nitride thin films deposited by magnetron sputtering onto (100) silicon. The ellipsometric data depend on the thin-film multilayer structure, the layer-phase composition, and the average orientation of the hexagonal grain c axes. In particular, we demonstrate the existence of spectral shifts of longitudinal optical phonons …

Complete-Range Activity-Based Rtl Power Estimation, Nur Kurt-Karsilayan

Dissertations and Theses

In recent years, power consumption has become a major concern in the electronic industry. Power reduction can be accelerated in the design cycle by fast and accurate power estimation tools. Since the units of lower-levels of design abstraction are transistors or gates, power estimation becomes a slow process at these levels. Therefore designers need to have tools for fast and accurate power estimation at the higher levels of design abstraction such as register transfer level (RTL).

A novel RTL power estimation technique called CRAB-RPE will be presented in this thesis. The CRAB power model is built upon four important properties …

Milled Carbon Fiber Reinforced Polymer Composition, Brian Massengale, Paul Schauer, Charles Dahle, Barry Gregerson, Bonnie Bachman, Thomas Oesterle

Economics Faculty Research & Creative Works

A milled carbon fiber reinforced polymer having increased abrasion resistive characteristics. The reinforced polymer comprises a base resin selected from the group consisting of polyolefins and polyamides. The base resin is combined with an amount of milled carbon fibers and further may be combined with polytetrafluoroethylene. The resulting composite materials have excellent friction and wear characteristics and are useful in the production of injection molded parts. The molded parts have a high impact strength, exhibit dimensional stability, are abrasion resistive, and are static dissipative, with the composite materials having particular utility as support fixtures for semiconductors during certain processing operations.