Engineering Commons^™

The Electrostatic Interaction Of Charged, Dust-Particle Pairs In Plasmas, M. E. Markes, P. F. Williams

Department of Electrical and Computer Engineering: Faculty Publications

We report the results of a study of the electrostatic interaction between negatively charged particles in a plasma. The goal of the study was to investigate the possibility of an attractive interaction which would make possible the formation of “molecules” of particles. For all approximations relating the positive ion density to the local electrostatic potential that we examined, we find that the interaction is repulsive for all particle separations.

A Simulation-Based Heuristic For Fleet Assignment, Sonia Rosario Anorga

FIU Electronic Theses and Dissertations

Integer programming, simulation, and rules of thumb have been integrated to develop a simulation-based heuristic for short-term assignment of fleet in the car rental industry. It generates a plan for car movements, and a set of booking limits to produce high revenue for a given planning horizon.

Three different scenarios were used to validate the heuristic. The heuristic's mean revenue was significant higher than the historical ones, in all three scenarios. Time to run the heuristic for each experiment was within the time limits of three hours set for the decision making process even though it is not fully automated. …

Evaluation Of Kentucky's Graduated Driver Licensing System, Kenneth R. Agent, Jerry G. Pigman, Lorena C. Steenbergen, Susan H. Pollack, Pamela S. Kidd, Caroline Mccoy

Kentucky Transportation Center Research Report

Kentucky's current GDL program, which applies to drivers up to age 18, was enacted in 1996. The program includes a six-month instruction permit for drivers under age 18 (minimum age 16), a restriction on driving between midnight and 6am and a requirement for adult-supervised driving for permit drivers. In addition, there is a six-point limit on traffic violations with a penalty of license suspension for drivers under age 18, a requirement for a four-hour driving safety education class (or driver education course) and a 0.02 ml/dl limit on blood alcohol concentration (continues up to age 21 ).

Objectives: The …

Study Of Photoelectrochemical Cells For Hydrogen Production By Water Splitting Using Cigs2/Cds Heterojunction, Florida Solar Energy Center, Neelkanth Dhere

FSEC Energy Research Center®

Study of Photoelectrochemical Cells for Hydrogen Production by Water Splitting Using CIGS2/CdS Heterojunction

A Web-Based Interface For Storing And Executing Simulation Models, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

The dominance of the Internet in the development of information and communication technology has made Web-based distributed solutions increasingly attractive. Apart from providing other services, the World Wide Web is being looked upon as an environment for hosting modeling and simulation applications. SIMAN is a simulation language that allows users to simulate discrete and continuous systems. In this research, a web-based interface or toolkit has been developed for storing and executing SIMAN simulation models over the Internet. This toolkit consists of a World Wide Web interface to SIMAN and a web-accessible database for storing user models. It provides users an …

Thermionic Cooling Of Optoelectronic And Microelectronic Devices, S. P. Lee, B. C. Lough, R. A. Lewis, C. Zhang

Faculty of Engineering - Papers (Archive)

Solid-state thermionic cooling has gained attention recently because of its potential high cooling power. Thermionic devices based on semiconductor heterostructures utilize the band-edge offset at a heterojunction as the thermionic emission potential barrier and a thin layer to separate the cold and hot junction. In this paper, we present the behavior of thermionic coolers with periodic barriers using gallium arsenide/aluminium gallium arsenide (GaAs/Al/sub x/Ga/sub 1-x/As) semiconductor heterostructures. The exact numerical calculation to model the device performance has shown that the thermal efficiency in a multilayer structure is optimised when the effect of phonon scattering is introduced in the model. Besides, …

Environmental Management Of Wastes In The Semiconductor And Electronics Industries, Samuel A. Vigil

Civil and Environmental Engineering

The management of wastes in the semiconductor and electronics industries requires a multidisciplinary approach that considers the health and safety of employees as well as the treatment and recycling of waste materials. The manufacturing of semiconductor devices requires the use of many toxic chemicals and gases. Air emissions from manufacturing tools must be carefully monitored both inside and outside of the fabrication facility. Liquid effluents must be collected and pretreated before discharge to local wastewater systems. The subsequent use and eventual discard of electronic devices such as television sets and personal computers by consumers has created a new set of …

High-Quality P-N Junctions With Quaternary Alingan/Ingan Quantum Wells, A. Chitnis, A. Kumar, M. Shatalov, V. Adivarahan, A. Lunev, J. W. Yang, Grigory Simin, M. Asif Khan, R. Gaska, M. Shur

Faculty Publications

We report on quaternary AlInGaN/InGaN multiple quantum well(MQW)light emitting diode structures grown on sapphire substrates. The structures demonstrate high quality of the p–njunctions with quaternary MQW. At low forward bias (below 2 V), the temperature dependent of current–voltage characteristics are exponential with the ideality factor of 2.28, which is in a good agreement with the model of the injected carrier recombination in the space charge region. This ideality factor value is approximately three times lower than for conventional GaN/InGaN light emitting diodes(LEDs). The obtained data indicate the recombination in p–njunction space charge region to be responsible for a current transport …

Corrosion Of Galvanized Fasteners: Appendix, Steel Framing Alliance

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

5. Burton Carl Anderson, Otto Vogl

Emeritus Faculty Author Gallery

No abstract provided.

Theory And Experiment Of High-Speed Cross-Gain Modulation In Semiconductor Lasers, Xiaomin Jin, T. Keating, Shun-Lien Chuang

Electrical Engineering

We present theory and experiment for the high-speed modulation response of a quantum-well (QW) laser in the presence of an external microwave modulated optical pump in the gain region. The model includes the effects of pump-induced stimulated recombination and cross-gain saturation. Expressions for the small-signal modulation response of the test laser under gain modulation are derived. We also present experimental results using a multiple-QW InGaAlAs Fabry-Perot (FP) laser at 1.552 μm as the test laser and an external pump by a 1.542 μm DFB laser. Comparison between electrical modulation and optical cross-gain modulation (XGM) of the test laser is also …

A Web-Based Interface For Storing And Executing Simulation Model, Ashu Guru, Paul Savory, Robert Williams

Department of Industrial and Management Systems Engineering: Faculty Publications

The dominance of the Internet in the development ofinformation and communication technology has madeWeb-based distributed solutions increasingly attractive.Apart from providing other services, the World Wide Webis being looked upon as an environment for hostingmodeling and simulation applications. SIMAN is asimulation language that allows users to simulate discreteand continuous systems. In this research, a web-basedinterface or toolkit has been developed for storing andexecuting SIMAN simulation models over the Internet.This toolkit consists of a World Wide Web interface toSIMAN and a web-accessible database for storing usermodels. It provides users an easy-to-use environment fordeveloping text-based simulation models using the SIMANsimulation language. It also …

Acuta Enews December 2000, Vol. 29, No. 12

ACUTA Newsletters

In This Issue

UConn Wins in Court

ACUTA EVENTS

Spotlight on Volunteers

DC Update

Board Report

Higher Education and Truth-in-Billing

Web Site Recognition

Welcome New Members

Positions Available

The Role Of Intelligent Transportation Systems (Its) In Intermodal Air Cargo Operations, H.-S. Jacob Tsao, Asim Rizwan

Faculty Publications

If California were a nation, it would be the sixth largest economy in the world. Efficient goods movement is crucial to California’s economy. Air freight consists predominantly of high-value, time-sensitive or time-definite goods, e.g., electronic equipment, emergency shipments, overnight packages, etc. Timely delivery of air freight has been an important element of many manufacturing and service operations in California. Therefore, the air cargo industry is a vital part of the state’s economy. The objectives of this research include (a) investigating and suggesting how the public sector in California can assist the air cargo industry in providing efficient services to businesses …

Performance Comparison Of A Roundabout Versus Two-Way Stop Controlled (Twsc) Intersections, Deogratias Eustace

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

The superior safety record of modern roundabouts is well known in Western Europe, Australia and in most British-influenced countries around the world. The experience from a single modern roundabout installed in the City of Manhattan, Kansas, some three years ago, also shares the same experience. A major study of the performance of Manhattan, Kansas, modern roundabout was conducted at Kansas State University (KSU) and was co-sponsored by Mac-Blackwell National Rural Transportation Study Center, Kansas State University, and the City of Manhattan. The study examined three intersections, one modern roundabout and two Two-Way Stop Controlled (TWSC) intersections with similar traffic conditions. …

Industry Guide To Selecting The Best Residential Window Options For The Florida Climate, Florida Solar Energy Center, Ross Mccluney

FSEC Energy Research Center®

It used to be said that windows are little more than holes in the insulation. It is true to some extent that poorly insulated and drafty windows in certain climates defeat the purpose of wall insulation. However, modern high performance windows are almost as good as opaque insulated wall sections, at least in terms of total energy savings over long periods of time. In some cases, they can be shown to actually out-perform insulated walls. Of course, they have the priceless additional benefits of providing views to the outdoors and natural daylight illumination indoors important issues of quality and comfort. …

Solitary Waves And Supersonic Reaction Front In Metastable Solids, Hendrik J. Viljoen, Lee L. Lauderback, D. Sornette

Hendrik J. Viljoen Publications

Motivated by an increasing number of remarkable experimental observations on the role of pressure and shear stress in solid reactions, explosions and detonations, we present a simple toy model that embodies nonlinear elasticity and dispersion as well as chemical or phase transformation. This generalization of the Toda Lattice provides an effective model for the description of the organization during an abrupt transformation in a solid. One of the challenges is to capture both the equilibrium degrees of freedom as well as to quantify the possible role of out-of-equilibrium perturbations. In the Toda Lattice, we verify that the particle velocities converge …

Design Methods For Auger Cip Piles In Compression, Giuliana A. Zelada, Richard Wesley Stephenson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Paper Reports on a Study of 43 Compression Load Tests (Five Fully Instrumented) and Ten Pullout Tests of Auger Cast-In-Place (ACIP) Piles in Sand. Eight Design Methods Reported in the Literature Were Used to Predict the Measured Pile Capacities. Ultimate Load Capacities of the ACEP Load Tests Were Determined using Two Different Definitions of Ultimate Capacity and Compared with Predictions. Load Transfer Behavior Was Determined from a Study of the Fully Instrumented Pile Tests and Compared to Predicted Values. Recommendations Are Made Regarding the Design Approach Most Appropriate for These Foundations and the Best Procedure for Estimating Ultimate Capacity …

Time-Varying System Identification Using Modulating Functions And Spline Models With Application To Bio-Processes, Sridhar Ungarala, Tomas B. Co

Chemical & Biomedical Engineering Faculty Publications

Time dependent parameters are frequently encountered in many real processes which need to be monitored for process modeling, control and supervision purposes. Modulating functions methods are especially suitable for this task because they use the original continuous-time differential equations and avoid differentiation of noisy signals. Among the many versions of the method available, Pearson–Lee method offers a computationally efficient alternative. In this paper, Pearson–Lee method is generalized for non-stationary continuous-time systems and the on-line version is developed. The time dependent parameters are modeled as polynomial splines inside a moving data window and recursion formulae using shifting properties of …

Itanium's New Basic Operation Of Fused Multiply-Add: Theoretical Explanation And Theoretical Challenge, Vladik Kreinovich

Departmental Technical Reports (CS)

A new Intel's 64-bit chip Itanium has a new instruction set which includes a fused multiply-add instruction x1+x2*x3. In this short article, we explain the empirical reasons behind the choice of this instruction, give possible theoretical explanation for this choice, and mention a related theoretical challenge.

Novel Processing Of Hydroxyapatite-Zirconia Composites Using Nano-Sized Particles, Mark R. Towler, I. R. Gibson, S. M. Best

Chemical and Biochemical Engineering Faculty Research & Creative Works

A method to produce composites of hydroxyapatite (HA) with ZrO2 (Y-TZP) additions between 0 and 10 wt % at a low sinter temperature of 750 °C is presented. The method limits the amount of reaction between the HA and ZrO2. A ZrO2 loading level that would improve strength while limiting the decomposition of the HA is studied.

An Atm System Model And Wireless Channel Simulation, Karen Dunne

Masters

Congestion in the low frequency regions of the electromagnetic spectrum and demand for support of high bandwidth applications has prompted widespread investigations into networking technologies and communications media. Traditional networking technologies such as Ethernet that are not capable of adequately supporting high bandwidth applications (e.g. videoconferencing) are being replaced by high speed, high bandwidth technologies such as Asynchronous Transfer Mode (ATM). In the communications media market, wireless systems are becoming ubiquitous due to their ease of installation and maintenance costs. In this research, the networking technology of interest is ATM. ATM used a cell switching architecture that allows seamless support …

Direct Generation Of Optical Diffractive Elements In Perfluorocyclobutane (Pfcb) Polymers By Soft Lithography, Gregory P. Nordin, J. Ballato, P. C. Deguzman, S. Foulger, H. Shah, D. Smith

Faculty Publications

Optically diffractive line gratings with 0.58- m feature sizes have been generated in 100- m perfluorocyclobutane (PFCB) polymer films by direct micromolding using only a silicon master. Strong reflectivities from the green to red portions of the visible spectrum, depending on incident beam angle, were observed with 3 dB bandwidths of approximately 30 nm. This negative mold-free technique permits, for the first time to our knowledge, feature reproduction at submicrometer size scales, eliminates several steps from conventional soft lithographic methods, and marks itself as a practical means for rapidly generating planar photonic structures that operate spectrally in the visible and …

Effect Of Gate Leakage Current On Noise Properties Of Algan/Gan Field Effect Transistors, S. L. Rumyantsev, N. Pala, M. S. Shur, R. Gaska, M. E. Levinshtein, M. Asif Khan, Grigory Simin, X. Hu, J. Yang

Faculty Publications

The effect of the gate leakage current fluctuations on noiseproperties of AlGaN/GaN heterostructurefield effect transistors(HFETs) has been studied in conventional HFET structures and in AlGaN/GaN metal-oxide-semiconductorheterostructurefield effect transistors (MOS-HFETs). The comparison of the noiseproperties of conventional AlGaN/GaN HFETs and AlGaN/GaN MOS-HFETs fabricated on the same wafer, allowed us to estimate the contribution of the gate currentnoise to the HFET’s output noise. The effect of the gate current fluctuations on output noiseproperties of HFETs depends on the level of noise in the AlGaN/GaN HFETs. For the transistors with a relatively high magnitude of the Hooge parameter α∼10⁻³, even a …

Finite-Aperture Wire Grid Polarizers, Michael A. Jensen, Gregory P. Nordin

Faculty Publications

The transmission characteristics of wire grid polarizers fabricated in finite apertures are investigated by using a three-dimensional finite-difference time-domain formulation. Specifically, the optical transmissivity and extinction ratio are characterized for a wide variety of geometrical parameters including aperture size in both dimensions, conducting wire fill factor, and polarizer thickness. A dispersive material model is used to investigate the performance of polarizers fabricated by using realistic metals at infrared wavelengths. The results indicate that the aperture dimension significantly impacts the polarizer transmission behavior and that the extinction of the unwanted polarization is often limited by depolarizing scattering that is due to …

Strassen's Algorithm Made (Somewhat) More Natural: A Pedagogical Remark, Ann Q. Gates, Vladik Kreinovich

Departmental Technical Reports (CS)

Strassen's 1969 algorithm for fast matrix multiplication is based on the possibility to multiply two 2 x 2 matrices A and B by using 7 multiplications instead of the usual 8. The corresponding formulas are an important part of any algorithms course, but, unfortunately, even in the best textbook expositions. they look very ad hoc. In this paper, we show that the use of natural symmetries can make these formulas more natural.

Hybridization Of Dna By Sequential Immobilization Of Oligonucleotides At The Air-Water Interface, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Anand Gole, K. N. Ganesh

Faculty Works

The hybridization of DNA by sequential electrostatic and hydrogen-bonding immobilization of single-stranded complementary oligonucleotides at the air-water interface with cationic Langmuir monolayers is demonstrated. The complexation of the single-stranded DNA molecules with octadecylamine (ODA) Langmuir monolayers was followed in time by monitoring the pressure-area isotherms. A large (and slow) expansion of the ODA monolayer was observed during each stage of complexation in the following sequence: primary single-stranded DNA followed by complementary single-stranded DNA followed by the intercalator, ethidium bromide. Langmuir-Blodgett (LB) films of the ODA-DNA complex were formed on different substrates and characterized using quartz-crystal microgravimetry (QCM), Fourier transform infrared …

Digital Signal Processing Implementation For Near Real-Time Wavelet Transformation System For Binary Images, Ovidio Alfonso

FIU Electronic Theses and Dissertations

Communication has become an essential function in our civilization. With the increasing demand for communication channels, it is now necessary to find ways to optimize the use of their bandwidth. One way to achieve this is by transforming the information before it is transmitted. This transformation can be performed by several techniques. One of the newest of these techniques is the use of wavelets. Wavelet transformation refers to the act of breaking down a signal into components called details and trends by using small waveforms that have a zero average in the time domain. After this transformation the data can …

Molecular Dynamics Calculations Of The Electrochemical Properties Of Electrolyte Systems Between Charged Electrodes, Richard L. Rowley, Paul S. Crozier, Douglas Henderson

Faculty Publications

We investigate the interfacial electrochemical properties of an aqueous electrolyte solution with discrete water molecules in slab geometry between charged atomistic electrodes. Long-range intermolecular Coulombic interactions are calculated using the particle particle particle mesh method with a modification to account for the slab geometry. Density distribution profiles and potential drops across the double layer are given for 0, 0.25, and 1 M aqueous electrolyte solutions each electrode surface charges. Results are compared qualitatively with experimental x-ray scattering findings, other computer simulation results, and traditional electrochemistry theory. The interfacial fluid structure characteristics are generally in good qualitative agreement with the conclusions …

Electrically Conductive Polymeric Materials And Use Thereof, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A polymer blend composition, capable of being made electrically conductive by application of heat having an electrically conductive upon doping polymer in undoped form; the undoped polymer is selected from the group consisting of substituted and unsubstituted polyparaphenylenevinylenes, polyanilines, polyazines, polythiophenes, poly-p-phenylene sulfides, polyfuranes, polyselenophenes, polyacetylenes filtered from soluble precursors and combinations and blends thereof, compounded and blended at a molecular scale with a dielectric polymer; wherein the dielectric polymer is selected from the group consisting of interpolymers of acrylonitrile-butadiene-styrene, acetal acrylic liquid crystal polymers, polybutylene terephthalate, polycarbonate, polyester, polyetherimide, polyethersulfone, polyethylene, polyethylene terephthalate, polyphenylene oxide, polyphenylene sulfide, polypropylene, polystyrene, …