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Articles 66961 - 66990 of 75088

Full-Text Articles in Engineering

Densities Of Vegetable Oils And Fatty Acids, Hossein Noureddini, B C. Teoh, L Davis Clements Dec 1992

Densities Of Vegetable Oils And Fatty Acids, Hossein Noureddini, B C. Teoh, L Davis Clements

Papers in Biomaterials

Complete data for density as a function of temperature have been measured for a number of vegetable oils (cramhe, rapeseed, corn, soybean, milkweed, coconut, lesquerella), as well as eight fatty acids in the range CS to C,, at temperatures from above their melting points to llQ°C (23Q°F). The specific gravity and density measure mente were performed according to American Society for Testing and Materials (ASTM) standard test methods D 368, D 891 and D 1298 for hydrometers and a modified ASTM D 369 and D 891 for pycnometers. Correlation constants, based on the experimental data, are presented for calculating the …


Sediment Delivery On Rill And Interrill Areas, John E. Gilley, D. C. Kincaid, W. J. Elliot, J. M. Laflen Dec 1992

Sediment Delivery On Rill And Interrill Areas, John E. Gilley, D. C. Kincaid, W. J. Elliot, J. M. Laflen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Equations which relate sediment delivery to a power function of flow rate and slope gradient were calculated in this study. The data used to parameterize the calculations were obtained from sites where crop residues had been removed. and moldboard plowing and disking had occurred. Measurements of sediment delivery resulting from simulated rainfall were obtained from preformed rills and interrill areas. The equations provided reliable sediment delivery estimates for selected soils located throughout the United States. To use the sediment delivery equations, soil-related parameter values must be identified. Multiple regression analyses were performed to relate parameter values used in the equations …


Efficient Accommodation Of May-Alias Information In Ssa Form, Ron Cytron, Reid Gershbein Dec 1992

Efficient Accommodation Of May-Alias Information In Ssa Form, Ron Cytron, Reid Gershbein

All Computer Science and Engineering Research

We present an algorithm for incrementally including may-alias information into Static Single Assignment form by computing a sequence of increasingly precise (and correspondingly larger) partial SSA forms. Our experiments show significant speedup of our method over exhaustive use of may-alias information, as optimization problems converge well before most may-aliases are needed.


Hands-On Structural Engineering Experiences With The "Anex" Mini-Laboratory, Richard A. Behr, Colin Othniel Benjamin, Azam A. Mirza Dec 1992

Hands-On Structural Engineering Experiences With The "Anex" Mini-Laboratory, Richard A. Behr, Colin Othniel Benjamin, Azam A. Mirza

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The ANEX facility has been developed to allow nearly real-time comparisons of analysis results with experimental data gathered on small-scale structural models. ANEX has been used successfully for in-class demonstrations, student-designed experiments, and comprehensive design/build competitions in an introductory structural analysis course at the University of Missouri-Rolla. An expert system is now being developed to guide ANEX users and to act as a trouble-shooter and advisor in the event that analytical and experimental results do not correlate acceptably well. ANEX, using only simple, small-scale model structures, is able to enrich structural engineering instruction by introducing students to the sophisticated capabilities …


Photopolymer-Based Stratified Volume Holographic Optical Elements, Gregory P. Nordin, A. R. Tanguay Dec 1992

Photopolymer-Based Stratified Volume Holographic Optical Elements, Gregory P. Nordin, A. R. Tanguay

Faculty Publications

We report the implementation of stratified volume holographic optical elements (SVHOE's) using DuPont's Omnidex holographic photopolymer material and an in situ exposure technique for simultaneous multilayer grating recording. Experimental measurement of the +1-order angular sensitivity of a seven-layer SVHOE structure shows remarkable agreement with both theory and numerical simulation for incidence angles near the Bragg angle. For SVHOE's having modulation layers that individually operate in the Bragg or transition diffraction regimes, the envelope of the SVHOE angular sensitivity is experimentally shown to approximate closely that of a single modulation layer.


Diffraction Properties Of Stratified Volume Holographic Optical Elements, Gregory P. Nordin, R. V. Johnson, A. R. Tanguay Dec 1992

Diffraction Properties Of Stratified Volume Holographic Optical Elements, Gregory P. Nordin, R. V. Johnson, A. R. Tanguay

Faculty Publications

We present a unified treatment of the diffraction properties of stratified volume holographic optical elements (SVHOE's). We show that the relative phasing of the diffraction orders as they propagate from layer to layer gives rise to a unique notched diffraction response of the +1 order (for the case of Bragg incidence) as a function of the normalized buffer-layer thickness, the grating spatial frequency, and the readout wavelength. For certain combinations of these parameters Bragg diffraction behavior characteristic of volume holographic optical elements (VHOE's) is observed, whereas for other combinations pure Raman-Nath behavior periodically recurs. By using these same relative-phasing arguments, …


Oxidative Mechanisms In Arterial Distension Injury: Observations Relevant To Restenosis After Angioplasty, Charles F. Babbs, Yuan Zhong Nov 1992

Oxidative Mechanisms In Arterial Distension Injury: Observations Relevant To Restenosis After Angioplasty, Charles F. Babbs, Yuan Zhong

Weldon School of Biomedical Engineering Faculty Working Papers

Background: To explore the hypothesis that tissue iron and reactive oxygen species, including superoxide (O2), mediate acute inflammatory and late hyperplastic responses to vascular injury, we studied experimental overdistension of normal carotid and femoral arteries in dogs. Experimental design: Arterial segments isolated in situ were distended with Ringer solution at 2 atmospheres pressure. In initial experiments the arteries were excised immediately after distension and immersed in diaminobenzidine solutions containing Mn++ ions to initiate histochemical reactions for O2. In other experiments distended arterial segments were reperfused with arterial blood in the presence or absence of the iron chelator, deferoxamine, or the …


Stabilization Of Passively Mode-Locked Semiconductor Laser Repetition Frequency, Roger Helkey, Dennis J. Derickson, Alan Mar, John Wasserbauer, Robert L. Thornton Nov 1992

Stabilization Of Passively Mode-Locked Semiconductor Laser Repetition Frequency, Roger Helkey, Dennis J. Derickson, Alan Mar, John Wasserbauer, Robert L. Thornton

Electrical Engineering

No abstract provided.


Nsf Sponsored Innovation In Engineering And Cornputer Science, Jacob Abel, Patricia Daniels, James G. Harris, Harry Hedges Nov 1992

Nsf Sponsored Innovation In Engineering And Cornputer Science, Jacob Abel, Patricia Daniels, James G. Harris, Harry Hedges

Electrical Engineering

No abstract provided.


Model For The Infrastructure Of Engineering Education, James G. Harris, Karen Frair, Win Aung, Susan T. Hill Nov 1992

Model For The Infrastructure Of Engineering Education, James G. Harris, Karen Frair, Win Aung, Susan T. Hill

Electrical Engineering

There are many ways to describe and model physical systems. The infrastructure of engineering education in the United States is an example of such a system, and it is the intent of this report to describe and model this infratructure. The means for doing this starts with the graduation statistics for the year 1989 given by the Computer Aided Science Policy Analysis & Research Database System (CASPAR) developed for the National Science Foundation by Quantum Research Corporation [1], and uses a simple categorization for the institutions that contribute to those statistics. This categorization sorts the post -secondary institutions in the …


Electrochemical Evaluation Of The Adherence Of Zinc To Aluminum Cathodes, Jang Sop Han, Thomas J. O'Keefe Nov 1992

Electrochemical Evaluation Of The Adherence Of Zinc To Aluminum Cathodes, Jang Sop Han, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

Excess fluoride ions in zinc electrolyte are known to cause problems with the removal of electrowon zinc from aluminum blanks. The mechanisms responsible for this undesirable adherence were studied. Acid zinc sulfate electrolyte similar to that employed in zinc electrowinning was used. Using electrolyte containing various fluoride ion concentrations, the initial nucleation and growth morphology of zinc and the aluminum electrode surface were examined using scanning electron microscopy. Electrochemical tests were also carried out in various solutions to obtain a better understanding of the polarization behavior of the system. © 1992.


Flow Excited Acoustic Resonance In A Deep Cavity: An Analytical Model, William W. Durgin, Hans R. Graf Nov 1992

Flow Excited Acoustic Resonance In A Deep Cavity: An Analytical Model, William W. Durgin, Hans R. Graf

Office of the Provost Scholarship

Flow past the opening of a deep cavity can excite and sustain longitudinal acoustic modes resulting in large pressure fluctuations and loud tone generation. An analytic model of the interaction of the free stream with the acoustic flow field using concentrated vortices in the shear layer is proposed. The model includes a computation of the power transferred by the traveling vortices to the acoustic oscillation in the cavity. Experimentally measured values for the vortex convection velocity and phase are used to enable calculation of the ensuing oscillation amplititude and frequency ratio. The radiated acoustic power is calculated using the model …


Acuta Enews November 1992, Vol. 21, No. 11 Nov 1992

Acuta Enews November 1992, Vol. 21, No. 11

ACUTA Newsletters

In This Issue

Interchangeable NPA, NNX

President's Message

Permanent 800 numbers

Industry/ Regulatory updates

Making voice mail effective

The fax-on-demand solution


Southern Nevada Effluent Wetlands: A Proposed Cooperative Venture Between The Bureau Of Reclamation & City Of Las Vegas, Bureau Of Reclamation Nov 1992

Southern Nevada Effluent Wetlands: A Proposed Cooperative Venture Between The Bureau Of Reclamation & City Of Las Vegas, Bureau Of Reclamation

Publications (WR)

Throughout North America there is a growing interest in constructed wetlands, both as relatively inexpensive, low-maintenance systems for removing nutrients from wastewater, and as a means of using municipal wastewater to enhance wildlife habitat and create public use opportunities. Because wetlands appear to have good potential as a component in the overall management of scarce water resources, the Bureau of Reclamation (Reclamation) has undertaken several cooperative research and demonstration projects to evaluate their effectiveness in a variety of local environments. While a number of projects have demonstrated that wetlands can be beneficially employed to improve water quality, few such projects …


Structural Ceramic Incorporating Boron Carbide Whiskers For The Strengthening Thereof, P. D. Ownby, J. Liu Nov 1992

Structural Ceramic Incorporating Boron Carbide Whiskers For The Strengthening Thereof, P. D. Ownby, J. Liu

Materials Science and Engineering Faculty Research & Creative Works

Ceramic composites, and in particular structural ceramic composites, have enhanced strength, toughness and abrasion resistance due to the presence of up to about 40 volume percent of relatively large boron carbide whiskers. Although whiskers of various sizes were studied, those of particular interest are whiskers having an average diameter greater than about 3 micrometers, and particularly about 5 to about 8 micrometers, with an average aspect ratio of about 50. Due to the larger size, which had been predicted to be detrimental, there is less respiratory health risk when using these whiskers in the manufacturing of thse improved ceramic composites. …


Computing Specificity, Ronald Loui, J. Norman, K. Stiefvater, A. Merrill, A. Costello, J. Olson Nov 1992

Computing Specificity, Ronald Loui, J. Norman, K. Stiefvater, A. Merrill, A. Costello, J. Olson

All Computer Science and Engineering Research

This note reports on an effort to implement a version of Poole's rule for specificity. Relatively, efficient implementation relies on correcting and improving a pruning lemma of Simari-Loui [92]. This in turn requires revision of Poole's specificity concept. The resulting system is a usable knowledge representation system with first-order-language and defeasible reasoning. Sample input and output are included in an appendix. It is a good candidate for multiple inheritance applications; it is useful for planning, but limited by the underlying search for plans.


Simulated Crystalline Structures Of Aromatic Polyimides, Tze Wing Poon, B. David Silverman, Ravi F. Saraf, Angelo R. Rossi, Paul S. Ho Nov 1992

Simulated Crystalline Structures Of Aromatic Polyimides, Tze Wing Poon, B. David Silverman, Ravi F. Saraf, Angelo R. Rossi, Paul S. Ho

Ravi Saraf Publications

Semicrystalline structures involving molecular packing and optimized chain conformations of three polyimides have been obtained with the CHARMM moleculardynamics program, and their densities calculated. An eclipsed conformation of face-toface stacking of polymer chains with a relative shift is observed, and the shift is found to depend upon the molecular characteristics of the planar unit and chain linearity. Threedimensional structures obtained by calculating the optimized edge-on confirmation of the stacked units yield the smallest calculated density for PMDA-ODA, namely 1.515 g/cm3, followed by BPDA-PDA with 1.644 g/cm3 and PMDA-PDA with 1.712 g/cm3. Both PMDA-ODA and BPDA-PDA …


Development Of Knowledge-Based Systems For Aluminum Welding, R. J. Napolitano, H. Kulluk, Mark L. Nagurka, R. P. Martukanitz, P. B. Dickerson Nov 1992

Development Of Knowledge-Based Systems For Aluminum Welding, R. J. Napolitano, H. Kulluk, Mark L. Nagurka, R. P. Martukanitz, P. B. Dickerson

Mechanical Engineering Faculty Research and Publications

No abstract provided.


The Programmers' Playground: I/O Abstraction For Heterogeneous Distributed Systems, Kenneth J. Goldman, Michael D. Anderson Nov 1992

The Programmers' Playground: I/O Abstraction For Heterogeneous Distributed Systems, Kenneth J. Goldman, Michael D. Anderson

All Computer Science and Engineering Research

A new high-level approach to interprocess communication in heterogeneous distributed systems in introduced, This approach, called I/O Abstraction, allows one to write each functional component of a distributed system as an encapsulated program that acts upon a set of local data structures, some of which may be published for external use. The functional components are separately configured by establishing logical connections among the published data structures. In order to illustrate this approach, we describe the The Programmers' Playground, a high-level language "veneer" and protocol designed to support I/O abstraction in heterogeneous computing environment. Support for communication among programs written in …


Investigation Of Strontium-Doped La(Cr, Mn)O3 For Solid Oxide Fuel Cells, Rasit Koc, Harlan U. Anderson Nov 1992

Investigation Of Strontium-Doped La(Cr, Mn)O3 For Solid Oxide Fuel Cells, Rasit Koc, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The (La, Sr) (Cr, Mn)O3 system was investigated in an effort to develop an interconnect and cathode materials for solid oxide fuel cells. Sintering studies were done in air at temperatures below 1500°C. Significant improvements in densification were observed with substitution of 50 mol% Mn for chromium and a density of 95% theoretical was achieved with the substitution of 70 mol% Mn for chromium in the La(Cr, Mn)O3 system. Electrical conductivity (d.c.) measurements were made as a function of temperature and oxygen activity. At 1000°C and 1 atm oxygen, the electrical conductivity ranged from 2.2-20 S cm-1 …


1992 Scholars And Artists Bibliography, Michael Schwartz Library, Cleveland State University, Friends Of The Michael Schwartz Library Oct 1992

1992 Scholars And Artists Bibliography, Michael Schwartz Library, Cleveland State University, Friends Of The Michael Schwartz Library

Scholars and Artists Bibliographies

This bibliography was created for the annual Friends of the Michael Schwartz Library Scholars and Artists Reception, recognizing scholarly and creative achievements of Cleveland State University faculty, staff and emeriti


Photoluminescence And Raman Studies Of Cds Films Grown By Metal-Organic Chemical Vapor Deposition On Si{111} Substrates, Alok K. Berry, P. M. Amirtharaj, Jing Tong Du, Jack L. Boone, Don D. Martin Oct 1992

Photoluminescence And Raman Studies Of Cds Films Grown By Metal-Organic Chemical Vapor Deposition On Si{111} Substrates, Alok K. Berry, P. M. Amirtharaj, Jing Tong Du, Jack L. Boone, Don D. Martin

Electrical and Computer Engineering Faculty Research & Creative Works

CdS epitaxial films grown using metal-organic chemical vapor deposition on Si{111} substrates at growth temperatures ranging from 270 to 325 °C have been characterized using photoluminescence and Raman spectroscopy. Out of all the samples the best optical behavior is obtained from that grown at the lowest temperature. Samples grown at the lowest temperature exhibited increased intensity of the bound excitonic peaks and reduced emission at the defect-related luminescence region. The Raman spectra were compatible with the film surface being normal to the c axis, indicating a preferred growth orientation. © 1992.


Hurricane Andrew Photovoltaic Traffic Control Relief, Florida Solar Energy Center, William Young Oct 1992

Hurricane Andrew Photovoltaic Traffic Control Relief, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

On August 24, 1992 Hurricane Andrew damaged and destroyed much of South Florida. The storm destroyed buildings, structures, and traffic devices along the highway. Travel was hazardous with debris in the roadway, traffic signals damaged or not working, and signs missing. This disaster offered a unique opportunity to research and evaluate the potential for using photovoltaic power systems in emergency traffic control situations. This report describes the findings of this study completed by the Florida Solar Energy Center sponsored by the Florida Department of Transportation.


Spaceflight Payload Design, Flight Experience G-408, William W. Durgin, Fred J. Looft, Albert Sacco, Jr., Robert Thompson, Anthony G. Dixon, Dino Roberti, Robert Labonte, Larry Moschini Oct 1992

Spaceflight Payload Design, Flight Experience G-408, William W. Durgin, Fred J. Looft, Albert Sacco, Jr., Robert Thompson, Anthony G. Dixon, Dino Roberti, Robert Labonte, Larry Moschini

Office of the Provost Scholarship

Worcester Polytechnic Institute's first payload of spaceflight experiments flew aboard Columbia, STS-40, during June of 1991 and culminated eight years of work by students and faculty. The Get Away Special (GAS) payload was installed on the GAS bridge assembly at the aft end of the cargo bay behind the Spacelab Life Sciences (SLS-l) laboratory. The experiments were turned on by astronaut signal after reaching orbit and then functioned for 72 hours. Environmental and experimental measurements were recorded on three cassette tapes which, together with zeolite crystals grown on orbit, formed the basis of subsequent analyses.

The experiments were developed over …


Thrust Vector Control Using Internal Airfoils, Eric J. Herup, Milton E. Franke, Jerold H. Friddell Oct 1992

Thrust Vector Control Using Internal Airfoils, Eric J. Herup, Milton E. Franke, Jerold H. Friddell

AFIT Patents

A thrust vectoring exhaust nozzle structure for an engine, such as a ramjet, rocket or turbojet, which generates thrust by expulsion of gaseous fuel combustion products along a thrust axis is described which comprises a generally axisymmetric housing defined along a central thrust axis including a wall structure defining an exhaust duct, and an axially spaced radially inwardly convergent portion, throat and radically outwardly divergent portion, and at least one airfoil disposed on the wall structure of the divergent portion and mounted for rotation about an axis substantially perpendicular to the thrust axis.


Acuta Enews October 1992, Vol. 21, No. 10 Oct 1992

Acuta Enews October 1992, Vol. 21, No. 10

ACUTA Newsletters

In This Issue

CMSU testing VISIT

President's message

A telecom intern's report

Annual ACUTA budget

Answers from "Regional Feud"

Membership Director's report


Short Pulse Generation Using Multisegment Mode-Locked Semiconductor Lasers, Dennis J. Derickson, R. J. Helkey, A. Mar, Judy R. Karin, J. G. Wasserbauer, J. E. Bowers Oct 1992

Short Pulse Generation Using Multisegment Mode-Locked Semiconductor Lasers, Dennis J. Derickson, R. J. Helkey, A. Mar, Judy R. Karin, J. G. Wasserbauer, J. E. Bowers

Electrical Engineering

No abstract provided.


Artificial Neural Networks For Robotics Coordinate Transformation, Stephen Aylor, Luis Rabelo, Sema E. Alptekin Oct 1992

Artificial Neural Networks For Robotics Coordinate Transformation, Stephen Aylor, Luis Rabelo, Sema E. Alptekin

Industrial and Manufacturing Engineering

Artificial neural networks with such characteristics as learning, graceful degradation, and speed inherent to parallel distributed architectures might provide a flexible and cost solution to the real time control of robotics systems. In this investigation artificial neural networks are presented for the coordinate transformation mapping of a two-axis robot modeled with Fischertechnik physical modeling components. The results indicate that artificial neural systems could be utilized for practical situations and that extended research in these neural structures could provide adaptive architectures for dynamic robotics control.


Waste-Surface Mapping Of The Fernald K-65 Silos Using A Structured Light Measurement System, B. L. Burks, Fred W. Depiero, M. A. Dinkins, J. C. Rowe, C. B. Selleck, D. L. Jacoboski Oct 1992

Waste-Surface Mapping Of The Fernald K-65 Silos Using A Structured Light Measurement System, B. L. Burks, Fred W. Depiero, M. A. Dinkins, J. C. Rowe, C. B. Selleck, D. L. Jacoboski

Electrical Engineering

During FY 1991, a remotely operated surface-mapping measurement system was developed by the Robotics & Process Systems Division at Oak Ridge National Laboratory for use in the K-65 waste-storage silos at Fernald, Ohio. The mapping system used three infrared line-generating laser diodes as illumination sources and three high-resolution, low-lux, calibrated, black-and-white, chargecoupled- device video cameras as receivers. These components were combined to form structured light source range and direction sensors with six different possible emitter-receiver pairs. A technology demonstration and predeployment tests were performed at Fernald during July and August 1991, using the empty Silo 4 into which was placed …


Morphology, Deformation, And Defect Structures Of Ticr2 In Ti-Cr Alloys, Katherine C. Chen, Samuel M. Allen, James D. Livingston Oct 1992

Morphology, Deformation, And Defect Structures Of Ticr2 In Ti-Cr Alloys, Katherine C. Chen, Samuel M. Allen, James D. Livingston

Materials Engineering

The morphologies and defect structures of TiCr2 in several Ti-Cr alloys have been examined by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM), in order to explore the room-temperature deformability of the Laves phase TiCr2. The morphology of the Laves phase was found to be dependent upon alloy composition and annealing temperature. Samples deformed by compression have also been studied using TEM. Comparisons of microstructures before and after deformation suggest an increase in twin, stacking faul4 and dislocation density within the Laves phase, indicating some but not extensive room-temperature deformability.