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Articles 181591 - 181620 of 197245

Full-Text Articles in Engineering

The Effects Of Low Doses (1 To 500 Kilograys) Of 100-Kev Electrons On Four Polymers, Cynthia Anne Bradbury Aug 1988

The Effects Of Low Doses (1 To 500 Kilograys) Of 100-Kev Electrons On Four Polymers, Cynthia Anne Bradbury

Physics Theses & Dissertations

Commercial films of polyetherimide (PEI), polyetheretherimide (PEEI), polyethylene terephthalate (PET), and polycarbonate (PC) were exposed in vacuum to l 00-keV electron radiation to total absorbed doses of l, l 0, l 00, 300, and 500 kilograys. The concentration of radiation-generated radicals, as measured by electron paramagnetic resonance (EPR), increased by over an order of magnitude in all four polymers. Correspondingly, the intensity of the infrared absorption peaks increased uniformly for all doses. Solubility tests resulted in decreased solubility in all polymers. IR, EPR, and solubility suggest dehydrogenation of the aliphatic C-H and phenyl C-H sites. The data indicated that cross …


Extrema Of The Magnitude And The Phase Of A Complex Function Of A Real Variable: Application To Attenuated Internal Reflection, R. M.A. Azzam Aug 1988

Extrema Of The Magnitude And The Phase Of A Complex Function Of A Real Variable: Application To Attenuated Internal Reflection, R. M.A. Azzam

Electrical Engineering Faculty Publications

Given a complex function F(ω) = |F(ω)|exp[jΔ(ω)] of a real argument ω, the extrema of its magnitude |F(ω)| and its phase Δ(ω), as functions of ω, are determined simultaneously by finding the roots of one common equation, Im[G(ω)] = 0, where G= (F′/F)2 and F′ = ∂F/∂ω. The extrema of |F| and Δ are associated with Re G < 0 and Re G > 0, respectively. This easy-to-prove theorem has a wide range of applications in physical optics. We consider attenuated internal reflection (AIR) as …


Analysis Of Radiant Barrier Car Shade Performance: Preliminary Experiments And Proof Of Concept, Florida Solar Energy Center, Danny Parker Aug 1988

Analysis Of Radiant Barrier Car Shade Performance: Preliminary Experiments And Proof Of Concept, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The Florida Solar Energy Center (FSEC) has monitored several automobiles over the last two months in order to investigate how hot interior temperatures in parked cars might be reduced through the use of improved technology, car shades. We observed interior temperatures in un-shaded stationary automobiles in Cape Canaveral, Florida to commonly reach 150 °F and dashboard temperatures to rise to nearly 200 °F. We found the addition of a conventional cardboard car shade behind the automobile windshield on sunny days to reduce the interior air temperatures by an average of 15 °F. Dashboard temperatures were reduced by 40 °F.

We …


Optimal Conjunctive Use-Sustained Yield Pumping Analysis For Eastern Arkansas, Rosalinda R.A. Cantiller, Richard C. Peralta, Hossein Azarmnia Aug 1988

Optimal Conjunctive Use-Sustained Yield Pumping Analysis For Eastern Arkansas, Rosalinda R.A. Cantiller, Richard C. Peralta, Hossein Azarmnia

Civil and Environmental Engineering Faculty Publications

The likelihood that irrigated agricultural acreages will increase in eastern Arkansas is high. This results from favorable agricultural soils, climate, and the availability of significant water resources.


Anomalous Temperature Dependence Of The Electric Field Gradient At The Y Site In In₀.₁Y₀.₉Ba₂Cu₃O9- Δ, Gary L. Catchen, Michael Blaszkiewicz, Anthony Baratta, Wayne Huebner Aug 1988

Anomalous Temperature Dependence Of The Electric Field Gradient At The Y Site In In₀.₁Y₀.₉Ba₂Cu₃O9- Δ, Gary L. Catchen, Michael Blaszkiewicz, Anthony Baratta, Wayne Huebner

Materials Science and Engineering Faculty Research & Creative Works

Perturbed angular correlation (PAC) spectroscopy has been used to measure a well-defined static electric quadrupole interaction in a superconducting ceramic, In0.1Y0.9Ba2Cu3O9-δ. Perturbation functions, Fourier transforms, and the derived PAC parameters are given for data taken at temperatures ranging from 77 to 1070 K. Indirect evidence is presented for the occupation of the Y site by the 111In-111Cd PAC probe. The derived electric field gradients were found to increase linearly with temperature. This result suggests the presence of soft, anisotropic vibrations in the structure. Additional evidence is presented …


30th Rocky Mountain Conference Jul 1988

30th Rocky Mountain Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 30th annual meeting of the Rocky Mountain Conference, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, July 31 - August 5, 1988.


Biocidal Derivatives Of Catechins, Peter E. Laks Jul 1988

Biocidal Derivatives Of Catechins, Peter E. Laks

Michigan Tech Patents

Sulfide derivatives of catechins derived from condensed tannins have broad spectrum biocidal characteristics. Epicatechin-4-alkylsulfides and cupric complexes thereof containing up to 20, preferably 5 to 15, carbon atoms are particularly effective biocides against wood rotting fungi and gram-positive bacteria. Such sulfides are prepared by reacting condensed tannin, either in the form of a purified tannin extract or comminuted plant tissue, with an appropriate thiol under mild acidic conditions.


Physical Mechanism Of Triggering In Trigatron Spark Gaps, F. E. Peterkin, P. F. Williams Jul 1988

Physical Mechanism Of Triggering In Trigatron Spark Gaps, F. E. Peterkin, P. F. Williams

P. F. (Paul Frazer) Williams Publications

Since the first trigatron spark gap was described by J. D. Craggs, M. E. Haine, and J. M. Meek [J. Inst. Electr. Eng. 93A, 963 (1946)], there has been controversy about the physical mechanism responsible for triggering the devices. In this letter we present experimental evidence that directly shows the sequence of physical events responsible for triggering in the gap we studied, and we present a model for trigatron triggering based on this information. We believe this model to be general and discuss it in light of existing literature. We briefly discuss the implications of the model for the engineering …


Mechanical Stemming Construction For Blast Holes And Method Of Use, Paul Nicholas Worsey Jul 1988

Mechanical Stemming Construction For Blast Holes And Method Of Use, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

A stemming construction for a blast hole loaded with an explosive charge, comprising a tapering wedge member dispersed in the blast hole outwardly of the explosive charge with its narrower end facing outwardly toward the mouth of the blast hole, and particulate stemming material in the blast hole outwardly of the wedge member. Detonation of the explosive drives the wedge member into the stemming material to wedge the stemming material against the walls of the blast hole. The wedge member is preferably cone-shaped and can be provided with a stabilizing rod to prevent it from tilting.


Santa Clara Magazine, Volume 30 Number 4, Summer 1988, Santa Clara University Jul 1988

Santa Clara Magazine, Volume 30 Number 4, Summer 1988, Santa Clara University

Santa Clara Magazine

12 - CARING FOR AGING PARENTS As Americans live longer, children find themselves making decisions for their parents.

16 - KIDNAPPED IN BEIRUT Charles Glass '72 writes about his 62 days of captivity and his escape to freedom.

20 - A MARK OF SUCCESS Mark Alsterlind '76, living in Van Gogh's hometown, pursues his dream to be a painter.

24 - GIFT OF THE MAGUS A wise man from England brought gifts still warmly treasured by Santa Clara.

26 - IS BRAINWASHING POSSIBLE? An absorbing interview on mind control with law professor Alan Scheflin.


Reactions Of Diketones With Phosphorous Ylides, Amal Mohamed Lakany Jul 1988

Reactions Of Diketones With Phosphorous Ylides, Amal Mohamed Lakany

Archived Theses and Dissertations

No abstract provided.


Earthquake Priority Routes For Mclean County, Kentucky, David L. Allen, Vincent P. Drnevich, L. John Fleckenstein, Mostafa Sayedsadr Jul 1988

Earthquake Priority Routes For Mclean County, Kentucky, David L. Allen, Vincent P. Drnevich, L. John Fleckenstein, Mostafa Sayedsadr

Kentucky Transportation Center Research Report

No abstract provided.


Impulse, Janet Blank-Libra, Bryon Bohlender, Jennifer Pint Jul 1988

Impulse, Janet Blank-Libra, Bryon Bohlender, Jennifer Pint

Impulse (Jerome J. Lohr College of Engineering Publication)

No abstract provided.


An Aeration Duct Design Model For Flat Grain Storage, Thomas C. Bridges, Douglas G. Overhults, Samuel G. Mcneill, G. M. White Jul 1988

An Aeration Duct Design Model For Flat Grain Storage, Thomas C. Bridges, Douglas G. Overhults, Samuel G. Mcneill, G. M. White

Biosystems and Agricultural Engineering Faculty Publications

Traditionally most grain is stored in circular type bins which provide a convenient means for handling and management. With the excess grain production and government loan programs of the past few years, some producers have used rectangular structures and covered piles to complement their round storages. The recommended management practices used with round bins are still required in those alternative storages and may be more critical in obtaining a quality end product.

One such recommended practice used with round bins is aeration. This practice is used to maintain a uniform temperature in the grain mass, preventing condensation and "hot" spots …


Evaluation Of A Polymer Asphalt Additive -- Kraton (1118 And 4141), L. John Fleckenstein, David L. Allen Jul 1988

Evaluation Of A Polymer Asphalt Additive -- Kraton (1118 And 4141), L. John Fleckenstein, David L. Allen

Kentucky Transportation Center Research Report

This report documents the use of two types of asphaltic concrete mixture designs. Both the control mixture and a Kraton rubber mixture were placed on sections of the Hazard Bypass, in Hazard, Kentucky. The location of the project is shown in Figure 1.


A Comparison Study Of Teaching Basic Drafting Concepts Using Computer-Assisted Equipment And Traditional Methods To Beginning Drafting Students At The Secondary Level, Thomas K. Farmer Jul 1988

A Comparison Study Of Teaching Basic Drafting Concepts Using Computer-Assisted Equipment And Traditional Methods To Beginning Drafting Students At The Secondary Level, Thomas K. Farmer

Graduate Research Papers

The purpose of this research was to determine if basic drafting concepts and skills can be learned by students using computer-assisted drafting equipment as well as those students who were taught using traditional drafting equipment. The two methods used in this study were a traditional style, using drafting boards with drafting machines, and the second was using computer-assisted drafting equipment (CAD).


Evaluation Of Hydraway Edge Drain On Pennyrile Parkway, David L. Allen, L. John Fleckenstein Jul 1988

Evaluation Of Hydraway Edge Drain On Pennyrile Parkway, David L. Allen, L. John Fleckenstein

Kentucky Transportation Center Research Report

No abstract provided.


Test 1609: Case International 7110 And 7210 Diesel 18-Speed, Nebraska Tractor Test Lab Jul 1988

Test 1609: Case International 7110 And 7210 Diesel 18-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 …


Test 1612: Case International 7140 And 7240 18-Speed, Nebraska Tractor Test Lab Jul 1988

Test 1612: Case International 7140 And 7240 18-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 …


The Lunar Date Of Ramesses Ii, Lee W. Casperson Jul 1988

The Lunar Date Of Ramesses Ii, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Due largely to the efforts of R. A. Parker, the various calendars used in Egypt are now fairly well understood. Dates which the Egyptians expressed in both their civil and lunar calendars can sometimes be determined exactly, and the study of such dates has been extremely important in efforts to establish an accurate Egyptian chronology. However, the successful use of this method obviously depends on one's ability to reconstruct accurately the astronomical and observational conditions on which the lunar calendar was based. The author re-examined the methods used to calculate lunar dates and have suggested some ways in which those …


Test 1610: Case International 7120 Diesel 18-Speed, Nebraska Tractor Test Lab Jul 1988

Test 1610: Case International 7120 Diesel 18-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 …


Test 1611: Case International 7130 And 7230 18-Speed, Nebraska Tractor Test Lab Jul 1988

Test 1611: Case International 7130 And 7230 18-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 …


Viscous Shock Layer Analysis Of Hypersonic Flows Over Long Slender Vehicles, Kam-Pui Lee Jul 1988

Viscous Shock Layer Analysis Of Hypersonic Flows Over Long Slender Vehicles, Kam-Pui Lee

Mechanical & Aerospace Engineering Theses & Dissertations

A method for solving the viscous shock-layer equations for hypersonic flows over long slender bodies is presented. The governing equations are solved by employing a spatial-marching implicit finite-difference technique. The two first-order equations, continuity and normal momentum, are solved simultaneously as a coupled set. This method yields a simple and computationally efficient technique.

Flows past hyperboloids and sphere cones with body half angles of five to 35 degrees are considered. The flow conditions included are from high Reynolds numbers at low altitudes to low Reynolds numbers at high altitudes. Detailed comparisons have been made with other predictions and experimental data …


Measurement Of Flow Components On Upland Areas Using Dye Dilution Techniques, S. C. Finkner, John E. Gilley Jul 1988

Measurement Of Flow Components On Upland Areas Using Dye Dilution Techniques, S. C. Finkner, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Dye dilution techniques can be used to measure rill and interrill-to-rill flow rates on upland areas. Procedures and equations for making flow measurements are described along with equations for estimating interrill length and width. If measurements of interrill length and rill width are available, use of simplified flow equations is possible.

Water and dye continuity concepts were utilized to develop generalized interrill-to-rill flow relationships. Measurement of flow from interrill-to-rill areas requires information on the concentration and rate of dye injection, and flow rate and dye concentration on both rill and interrill areas at a downslope sampling location. Dye dilution techniques …


A Finite Element Formulation For The Large Deflection Random Response Of Thermally Buckled Structures, James Eugene Locke Jul 1988

A Finite Element Formulation For The Large Deflection Random Response Of Thermally Buckled Structures, James Eugene Locke

Mechanical & Aerospace Engineering Theses & Dissertations

The effects of temperature and acoustic loading are included in a theoretical finite element large deflection formulation for thin, isotropic plate and beam type structures. Thermal loads are applied as steady-state temperature distributions, and acoustic loads are taken to be stationary and Gaussian with zero mean and uniform magnitude and phase over the surface of the structure. Material properties are considered to be independent of temperature. Also, inplane and rotary inertia terms are assumed to be neglegible, and all inplane edge conditions are taken to be immovable. For the random vibration analysis, cross correlation terms are included.

The nature of …


Effect Of Fabric On Stress-Strain Relation, Volume Change, And Dynamic Shear Modulus Of Ottawa Sand, Ming-Tarng Chen Jul 1988

Effect Of Fabric On Stress-Strain Relation, Volume Change, And Dynamic Shear Modulus Of Ottawa Sand, Ming-Tarng Chen

Civil & Environmental Engineering Theses & Dissertations

To evaluate the effect of fabric on stress-strain behavior, volume change, and the dynamic shear modulus of Ottawa sand, four series of tests on hollow cylindrical specimens were performed by a torsional simple shear/resonant apparatus. All specimens were first isotropically consolidated, and then sheared along the different stress paths while keeping the mean effective stress constant. The test results showed that depositional fabric had a slight influence on the stress-strain behavior, and one half-cycle of pre-shearing created a clear anisotropy on the stress-strain response. The intermediate principal stress had a dominant effect on volume change characteristics but it might not …


Application Of Advanced Grid Generation Techniques For Flow Field Computations About Complex Configurations, Monchai Kathong Jul 1988

Application Of Advanced Grid Generation Techniques For Flow Field Computations About Complex Configurations, Monchai Kathong

Mechanical & Aerospace Engineering Theses & Dissertations

In the computation of flow fields about complex configurations, it is very difficult to construct a boundary-fitted coordinate system. An alternative approach is to use several grids at once, each of which is generated independently. This procedure is called the "multiple grids" or "zonal grids" approach, and its applications are investigated in this study. The method is a conservative approach and provides conservation of fluxes at grid interfaces. The Euler equations are solved numerically on such grids for various configurations. The numerical scheme used is the finite-volume technique with a three-stage Runge-Kutta time integration. The code is vectorized and programmed …


Atamm Multicomputer System Design, William Robert Tymchyshyn Jul 1988

Atamm Multicomputer System Design, William Robert Tymchyshyn

Electrical & Computer Engineering Theses & Dissertations

The Algorithm To Architecture Mapping Model, or ATAMM, is a graph theoretic design methodology that has been created to resolve design and performance issues involved with concurrent processing. Petri-net marked graphs are used to represent the computational environment.

This thesis describes the development of a multicomputer system which will operate within the bounds specified by the ATAMM model. The system is first designed and implemented using the framework of standard multicomputer design theory. A validation is then performed by the comparison of the system's computational performance to results predicted by ATAMM. This validation is shown to be successful for three …


Numerical Simulation Of Turbulent Flows Past Three-Dimensional Cavities, Shivakumar Srinivasan Jul 1988

Numerical Simulation Of Turbulent Flows Past Three-Dimensional Cavities, Shivakumar Srinivasan

Mechanical & Aerospace Engineering Theses & Dissertations

Computations have been performed to simulate turbulent supersonic, transonic, and subsonic flows past three-dimensional deep, transitional, and shallow cavities. Simulation of these self sustained oscillatory flows has been generated through time accurate solutions of Reynolds averaged full Navier-Stokes equations using the explicit MacCormack scheme. The Reynolds stresses have been modeled, using the Baldwin-Lomax algebraic turbulence model with certain modifications. The computational results include instantaneous and time averaged flow properties everywhere in the computational domain. Time series analyses have been performed for the instantaneous pressure values on the cavity floor. Comparison with experimental data is made in terms of the mean …


Calculations Of Three-Dimensional Transonic Flows Using The Implicit Formulation Of The Isenthalpic Euler Equations With Flux Vector Splitting, Frank E. Cannizzaro Jul 1988

Calculations Of Three-Dimensional Transonic Flows Using The Implicit Formulation Of The Isenthalpic Euler Equations With Flux Vector Splitting, Frank E. Cannizzaro

Mechanical & Aerospace Engineering Theses & Dissertations

A numerical method for solving three-dimensional transonic flows using the isenthalpic formulation of the Euler equations is developed. The method uses van Leer's flux vector splitting to solve the implicit formulation of the governing equations, which are applied to a cell centered finite-volume scheme. A three factor spatial approximate factorization is implemented in solving the implicit part of the governing equations. Time marching to a steady state solution requires short computational times due to the relative efficiency of the basic method. Computational times are further reduced by the implementation of the multigrid acceleration technique, which provided converged solutions in approximately …