Engineering Commons^™

Safe Stratified Datalog With Integer Order Programs, Peter Revesz

School of Computing: Conference and Workshop Papers

Guaranteeing termination of programs on all valid inputs is important for database applications. Termination cannot be guaranteed in Stratified Datalog with integer (gap)-order programs on generalized databases because they express any Turing-computable function. This paper introduces a restriction of those programs that can express only computable queries. The restricted language has a high expressive power and a non-elementary data complexity.

Acuta Enews September 1995, Vol. 24, No. 9

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Awards presented at 24th Annual Conference

New Board of Directors looks forward to 1996

Board Report

Welcome New Members

Host needed for Winter Seminar

President's Message

Driving smart on the Info Highway

Tractor Test Museum Committee Minutes August 11, 1995, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Bid for Roof Replacement National Historic Site Additional Support

Acuta Enews August 1995, Vol. 24, No. 8

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From the President

ISDN at MSU

Disaster Recovery

From ACUTA Headquarters: Emeritus Membership Status approved

Corrosion And Protection Of A Conductive Silver Paste, V. Brusic, G. S. Frankel, J. Roldan, Ravi F. Saraf

Ravi Saraf Publications

One of the possible uses for a conductive paste is as an adhesive in interconnect technology that could replace PbSn solder. The interconnections are expected to perform under a variety of environmental conditions, and with an applied voltage. Thus knowledge of their corrosion and dissolution resistance is of utmost importance. This is a study of the dissolution and protection of polymer/metal composite films, prepared with a high loading of silver or gold particles. Electrochemical tests were conducted in a droplet of triple-distilled water with or without benzotriazole (BTA) and BTA derivatives. Results indicate that, in spite of some protection obtained …

Method Of Making Quasicrystal Alloy Powder, Protectivecoatings And Articles, Jeffrey E. Shield, Alan I. Goldman, Iver E. Anderson, Timothy W. Ellis, R. William Mccallum, Daniel J. Sordelet

Department of Mechanical and Materials Engineering: Faculty Publications

A method of making quasicrystalline alloy particulates wherein an alloy is superheated and the meltis atomized to form generally spherical alloy particulates free of mechanical fracture and exhibiting a predominantly quasicrystalline in the atomized condition structure. The particulates can be plasma sprayed to form a coating or consolidated to form an article of manufacture.

Acuta Enews July 1995, Vol. 24, No. 7

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Board report

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Wiring today for tomorrow

Card technology

DC at a glance

From ACUTA Headquarters

Acuta Enews July 1995, Vol. 24, No. 7

ACUTA Newsletters

In This Issue

Board report

Presidents message

Wiring today for tomorrow

Card technology

DC at a glance

From ACUTA Headquarters

Acuta Enews June 1995, Vol. 24, No. 6

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Board report

President's message

Charles Co. Community College's telecommuting project

Brock's campus ID card

From ACUTA Headquarters

Time Dependence Of Multiply Scattered Diffuse Ultrasound In Polycrystalline Media, Joseph A. Turner, Richard L. Weaver

Department of Engineering Mechanics: Faculty Publications

Time domain results are presented for the multiply scattered longitudinal intensity backscattered from a polycrystalline medium. The results are solutions to the ultrasonic radiative transfer equation (URTE), the derivation of which is based upon radiative transfer theory. Unlike steady-state solutions obtained previously, time domain solutions will more closely correspond to experiments that use tone burst sources. This paper is concerned with the time dependence of the backscattered longitudinal intensity from a polycrystalline medium excited by a normally incident longitudinal wave idealized as an impulsive deposition of energy. It is shown that multiple scattered effects become significant at times on the …

Simulation Of The Growth Of Cvd Films, Jacob J. Thiart, Vladimir Hlavacek, Hendrik J. Viljoen

Papers in Materials Science

Chemical vapor deposition (CVD) is the preferred method of manufacture for solid films used in many industrially important thin and thick film applications. Requirements for the physical, mechanical and electrical properties of these films are becoming increasingly difficult to achieve, and deposition morphology plays an important role in this regard. Recently, we proposed a continuum model describing the evolution of a gassolid interface during atmospheric pressure CVD (Viljoen er al., 1994). A linear stability analysis (LSA) was used to determine the effect of reactor conditions on planar growth stability. The present paper discusses numerical solution of this model, and uses …

Acuta Enews May 1995, Vol. 24, No. 5

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Board report

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DC at a glance

Benchmarks for your telecom operation

From ACUTA Headquarters

Determination Of Alas Optical Constants By Variable Angle Spectroscopic Ellipsometry And A Multisample Analysis, C. M. Herzinger, H. Yao, Paul G. Snyder, F. G. Celii, Y. C. Kao, B. Johs, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Using variable angle spectroscopic ellipsometry, optical constants for AlAs (1.4-5.0 eV) are presented which are simultaneously compatible with measured data from four different samples. The below-gap index values are compatible with published prism measured values. The second derivative spectrum are compatible with published values above the direct band gap. The AlAs spectra is Kramers-Kronig self-consistent over the measured range and is compatible with published values from 0.6 to 1.4 eV. The optical constants for thin (<50 >Å) GaAs caps on AlAs are shown to be different from bulk GaAs values and require special consideration when fitting ellipsometric data. For the …

Tractor Test Museum Committee Minutes April 21, 1995, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Hitchcock Foundation Potential Committee Member Tree Removal

Acuta Enews April 1995, Vol. 24, No. 4

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Directory updates

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Optical Constants Of GaXIn1-XP Lattice Matched To Gaas, Mathias Schubert, V. Gottschalch, Craig M. Herzinger, Huade Yao, Paul G. Snyder, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

The optical constants of Ga_0.51In_0.49P have been determined from 0.8 to 5.0 eV using variable-angle spectroscopic ellipsometry measurements at room temperature. The metal-organic vapor-phase-epitaxy-grown samples were x-ray analyzed to confirm lattice matching to the GaAs substrate. The effects of the native oxide were numerically removed from the data to determine the intrinsic optical constants. This is important because the optical constants reported become generally useful for modeling multiple-layer structures. A Kramers-Kronig analysis was used to reduce interference-related fluctuations in the below-gap refractive index. Near the band edge a mathematical form for excitonic absorption was included. Critical …

Novel Kalman Filtering Method For The Suppression Of Gyroscope Noise Effects In Pointing And Tracking Systems, Marcelo C. Aigrain

Department of Electrical and Computer Engineering: Faculty Publications

A primary cause of degraded performance in pointing and tracking systems is the jitter in the line of sight. This jitter is caused by the residual angular motion of the stabilized platform within the system. A major contributor to this residual motion is the gyroscope noise. Thus, to reduce angular jitter, lower-noise gyroscopes are selected, generally at a premium cost. Another approach is to enhance the accuracy of the gyroscopes electronically (by suppressing measurement noise) before their outputs are fed into the stabilized platform control system. Optimal filtering techniques can be used for this purpose. The goal is to estimate …

Tractor Test Museum Committee Meeting March 17th, 1995, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Camp Creek Threshers Foundation Funds 1915 Ford tractor restoration

Acuta Enews March 1995, Vol. 24, No. 3

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Board report

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ACUTA hires Administrative

DC at a glance

Info Superhighway grant

From ACUTA Headquarters

Reaction Fronts In A Porous Medium. Approximation Techniques Versus Numerical Solution, Fernando Escobedo, Hendrik J. Viljoen

Papers in Reaction Kinetics

The flame sheet approximation (FS) and a novel polynomial approximation technique (PA) are compared in terms of their capability to describe reaction fronts of highly exothermic reactions in a porous medium. A one-phase model and a two-phase model of a system with adiabatic walls and a radiant output (to approximate the case of a porous radiant burner) are included in the analysis. By matching the reaction zone solution found by either the FS or PA method with the solutions of the nonreacting zones, the temperature, conversion, and position of the reaction zone were determined. Numerical solutions for catalytic and noncatalytic …

Excess Heat Capacity Surfaces For Water-Alkanol Mixtures By The Uniquac Model, Yaşar Demirel, Halime Ö. Paksoy

Papers in Physical Chemistry

Hydroorganic mixtures are industrial solvents that can serve as media to solubilize either water in hydrocarbon or a hydrophobic substance in water. In many cases the solubilizing capability is obtained via a homogeneous complex aqueous mixtures containing an alcohol. Since excess heat capacity C_P^E, is very sensitive to structural changes in mixtures, concentration and temperature dependence of C_P^E have been calculated by using the UNIQUAC model for the mixtures methanol(l)-water(%, ethanol(l)-water(2), and l-propanol(l)-water(2). The temperature-dependent parameters of the model estimated directly from C_P^E data at more than one different isotherm are used in …

Incorporation Of Zn In Gaas During Organometallic Vapor Phase Epitaxy Growth Compared To Equilibrium, W. Reichert, C.Y. Chen, W.M. Li, Jeffrey E. Shield, R.M. Cohen, D.S. Simons, P.H. Chi

Nebraska Center for Materials and Nanoscience: Faculty Publications

The zinc concentration measured after organometallic vapor phase epitaxy (GMVPE) growth on (100)-oriented GaAs at 700 °C has been compared to the zinc concentration measured after in-diffusion under near-equilibrium conditions. During diffusion, the concentration of Zn 20 nm below the surface was found to vary with P_Zn^1/2, as expected for bulk solid-vapor equilibrium. During growth, the concentration of Zn varied linearly with P_Zn up to a maximum value which was found to correspond to the solubility limit set by second phase formation, e.g., growth of Zn₃As₂. Although large differences were observed between …

Apparatus For Forming Fine Particles, Dennis R. Alexander

Department of Electrical and Computer Engineering: Faculty Publications

To alter feedstock material, the material is exposed to laser radiation applied at a selected angle of incidence, intensity and wavelength related to the refractive index of the feedstock material. Fine uniform particles may be formed through vapor explosion and/or plasma formation and used by this method to coat surfaces, such as with paint or adhesive or to supply uniform small particles to a heat engine. Moreover, moving materials such as a column of liquid may be subjected to high internal pressure and temperature for creating physical and chemical changes.

Inp Optical Constants Between 0.75 And 5.0 Ev Determined By Variable-Angle Spectroscopic Ellipsometry, C. M. Herzinger, Paul G. Snyder, B. Johs, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Using variable-angle spectroscopic ellipsometry (VASE) InP optical constants for photon energies have been determined in the range from 0.75 to 5.0 eV, which includes the fundamental gap at 1.35 eV. Above 1.5 eV the results are consistent with previously measured pseudovalues from an oxide-stripped sample when a very thin residual over-layer is accounted for. They are also shown to be compatible with previously published prism measurements of refractive index below the band gap. Real and imaginary parts of the dielectric function are shown to be Kramers-Kronig (KK) self-consistent above the gap, and the KK analysis was used to extend the …

Acuta Enews February 1995, Vol. 24, No. 2

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Board Report

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ACUTA hires Computer Services Administrator

Peer presentations at Maui

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Losslees Compression Of Rgb Color Images, Nasir D. Memon, Khalid Sayood

Department of Electrical and Computer Engineering: Faculty Publications

Although much work has been done toward developing lossless algorithms for compressing image data, most techniques reported have been for two-tone or gray-scale images. It is generally accepted that a color image can be easily encoded by using a gray-scale compression technique on each of the three accounts the substantial correlations that are present between color planes. Although several lossy compression schemes that exploit such correlations have been reported in the literature, we are not aware of any such techniques for lossless compression. Because of the difference in goals, the best way of exploiting redundancies for lossy and lossless compression …

Campus Telecommunications Systems: Managing Change, Association Of College And University Telecommunications Administrators

ACUTA: Other Publications

The purpose of this book is to provide a broadbased understanding of the rapidly changing environment of campus telecommunications. The anticipated audience for this material is the non-technical university administrator who may not have direct responsibility for telecommunications, but has a need to understand the general environment in which his telecommunications manager functions and the basic concepts of the technology. Five topic areas were selected that best cover the preponderance of issues. No attempt has been made to associate or closely coordinate materials from one chapter's subject to that of any other. Each chapter generally stands alone. In total, however, …

Acuta Enews January 1995, Vol. 24, No. 1

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Board Report

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Telecom Resources Library Update

Developing a campus telecom plan

Precautions combat

phone fraud

DC at a glance

Test 1688: John Deere 8100 Diesel 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE

General

Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure.

The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Models For Association Of Metal Ions With Heterogeneous Envimnmeatal Sorbents. 1 . Complexation Of Co(Ll) By Leonardiie Humic Acid As A Function Of Ph And Nac104 Concentration, John Westall, John Jones, Gary Turner, John M. Zachara

United States Department of Energy: Publications

A discrete log K spectrum model has been developed to represent the binding of protons and Co(II) to leonardite humic acid (LHA) over a wide variation of solution composition: pH 4.5-9.5, [NaC1O₄] 0.01 - 0.1 M, T_Co 200 nM-500 µM. The model is internally selfconsistent over the range indicated without an explicit electrostatic term. The LHA was represented by four acid sites (HL_i = H⁺ + L_i^-) with a fixed pK_a spectrum: pK_a = 4, 6, 8, and 10. From the acid base titration data, total concentrations of these sites …