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1998

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Articles 481 - 510 of 1354

Full-Text Articles in Engineering

The Effect Of Grain Size On Magnetic Properties In Sm2Fe17NX, Jeffrey E. Shield, D.J. Branagan, C.P. Li, R.W. Mccallum May 1998

The Effect Of Grain Size On Magnetic Properties In Sm2Fe17NX, Jeffrey E. Shield, D.J. Branagan, C.P. Li, R.W. Mccallum

Nebraska Center for Materials and Nanoscience: Faculty Publications

The microstructures of melt spun Sm11Fe89 and (Sm11Fe89)94Ti3C3 have been investigated under different solidification conditions. The magnetic properties of the nitrided materials have been related to the observed microstructures. Melt spinning of the Sm11Fe89 alloys resulted in grain sizes at or above the single domain limit. The addition of Ti and C resulted in an order of magnitude refinement in the microstructural scale. The magnetic properties of the samples with grain sizes below the single domain limit decreased with decreasing grain size due to increased intergranular exchange coupling.


Advanced Fenestration And Daylighting Systems, Florida Solar Energy Center, Ross Mccluney May 1998

Advanced Fenestration And Daylighting Systems, Florida Solar Energy Center, Ross Mccluney

FSEC Energy Research Center®

Advanced fenestration and daylighting systems form an interesting new class of devices and products for introducing natural lighting (daylight illumination) into buildings. They are split into two distinct classes. Advanced fenestration systems are new high-performance glazing and reflecting systems for otherwise conventional windows which offer specialized spectral and/or angular selectivity, intended for improved illumination quantity and quality while managing solar radiant heat gain to meet both human comfort and energy conservation objectives. These spectral and/or angular selectivities can be built into the glazings, incorporated into new objects placed between the panes, or they can be part of objects attached to …


Iron Phosphate Compositions For Containment Of Hazardous Metal Waste, D. E. Day May 1998

Iron Phosphate Compositions For Containment Of Hazardous Metal Waste, D. E. Day

Materials Science and Engineering Faculty Research & Creative Works

An improved iron phosphate waste form for the vitrification, containment and long-term disposition of hazardous metal waste such as radioactive nuclear waste is provided. The waste form comprises a rigid iron phosphate matrix resulting from the cooling of a melt formed by heating a batch mixture comprising the metal waste and a matrix-forming component. The waste form comprises from about 30 to about 70 weight percent P205 and from about 25 to about 50 weight percent iron oxide and has metals present in the metal waste chemically dissolved therein. The concentration of iron oxide in the waste form along with …


1998 - The Third Annual Symposium Of Student Scholars May 1998

1998 - The Third Annual Symposium Of Student Scholars

Symposium of Student Scholars Program Books

The full program book from the Third Annual Symposium of Student Scholars, held on May 8th, 1998. Includes abstracts from the presentation and posters.


Electroluminescent Device Having Electroluminescent Compound And Liquid Crystalline Compound, Rifat A.M. Hikmet, David Braun, Aemilianus G.J. Staring, Hermanmus F.M. Schoo, Johan Lub May 1998

Electroluminescent Device Having Electroluminescent Compound And Liquid Crystalline Compound, Rifat A.M. Hikmet, David Braun, Aemilianus G.J. Staring, Hermanmus F.M. Schoo, Johan Lub

Electrical Engineering

A description is given of an electroluminescent device (1) having an LED structure, which is composed of an active layer (7) of oriented liquid-crystalline and electroluminescent compounds and a transparent positive electrode layer (5) which is preferably made from an electroconductive polymer. By previously rubbing the electrode layer (5) in one direction with a velvet cloth, an orientation is induced in the molecules in the active layer (7), the orientation being frozen by cooling or polymerization. The electroluminescent device (1) emits polarized light whose direction of polarization is parallel to the direction of rubbing.


Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf May 1998

Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A simple process for card assembly by Direct Chip Attachment (DCA) uses electrically conductive adhesives. Two methods create the same intermediate wafer product with a layer of insulative thermoplastic and conductive thermoplastic bumps. After sawing or dicing the wafer to form the chips, the chips are adhered to chip carriers with conductive pads which match the conductive thermoplastic bumps, using heat and pressure. Chips may be easily removed and replaced using heat.


Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf May 1998

Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A simple process for card assembly by Direct Chip Attachment (DCA) uses electrically conductive adhesives. Two methods create the same intermediate wafer product with a layer of insulative thermoplastic and conductive thermoplastic bumps. After sawing or dicing the wafer to form the chips, the chips are adhered to chip carriers with conductive pads which match the conductive thermoplastic bumps, using heat and pressure. Chips may be easily removed and replaced using heat.


Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf May 1998

Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A simple process for card assembly by Direct Chip Attachment (DCA) uses electrically conductive adhesives. Two methods create the same intermediate wafer product with a layer of insulative thermoplastic and conductive thermoplastic bumps. After sawing or dicing the wafer to form the chips, the chips are adhered to chip carriers with conductive pads which match the conductive thermoplastic bumps, using heat and pressure. Chips may be easily removed and replaced using heat.


The Effects Of Beryllium Additions On The Oxidation Of Nickel Aluminide And Titanium Aluminide Based Intermetallics, R. H. Hanrahan Jr., Katherine C. Chen, M. P. Brady May 1998

The Effects Of Beryllium Additions On The Oxidation Of Nickel Aluminide And Titanium Aluminide Based Intermetallics, R. H. Hanrahan Jr., Katherine C. Chen, M. P. Brady

Materials Engineering

The effects of Be additions on the oxidation behavior of β-NiAl in moist air at 1000°C and borderline alumina-forming y (TiAI) + Laves Ti-Al-Cr based alloys at 800°C and 1000°C in dry and moist air were investigated. The addition of Be to β-NiAl suppressed the formation of transient alumina, and resulted in the formation of a protective BeAl2O4 spinel phase. In dry air, the addition of Be to the Ti-AI-Cr alloys also resulted in the formation of a protective BeAl2O4 spinel phase. In moist air, only Ti-AlCr- Be alloys with a high Cr content …


Remedial Action Plan For A Petroleum Hydrocarbon Release, Marty E. Murrietta May 1998

Remedial Action Plan For A Petroleum Hydrocarbon Release, Marty E. Murrietta

UNLV Theses, Dissertations, Professional Papers, and Capstones

This Remediation Action Plan (RAP) presents the methods and results of feasibility testing, the screening and selection of remedial options, preliminary conceptual design, methods, permitting requirements, recommendations and cleanup goals for on- and off-site remediation of petroleum hydrocarbon impacted soil and groundwater at an undisclosed site in Laughlin, Nevada. This site is an active convenience store and former retail fueling station. Plans are being made for the demolition of the fueling station and construction of a Factory Outlet Mall on the former refueling station site and surrounding properties to the south, west, and northwest. Remediation activities cannot significantly interfere with …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 14, Number 5, May 1998, College Of Engineering And Computer Science, Wright State University May 1998

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 14, Number 5, May 1998, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.


From Country Club To Ghetto : The Uneven Distribution Of Energy Cost Between Areas Of Different Economic Class, Kenya R. Reeves May 1998

From Country Club To Ghetto : The Uneven Distribution Of Energy Cost Between Areas Of Different Economic Class, Kenya R. Reeves

Electronic Dissertations and Theses

For years there has been controversy over the uneven distribution of energy costs. Documented energy complaints are on file on the state as well as national level of government. Various sources have performed adequate research that shows that there is a difference in energy cost based on economic class. In order to prove that persons of different economic class pay different rates for energy, two distinct areas of Baton Rouge were issued surveys-Scotlandville and Bluebonnet. Questions used were retrieved from secondary sources and Entergy as well. From the results computed, there is definitely a difference in energy costs depending upon …


Acuta Enews May 1998, Vol.27, No. 5 May 1998

Acuta Enews May 1998, Vol.27, No. 5

ACUTA Newsletters

In This Issue

Board Approves Slate of Nominees

Moderators &Monitors Needed in San Diego!

Board Report

Let there be (Blue) Light!

Contractors on Your Campus?

DC at a Glance

Book Your Room for San Diego NOW!

Positions Available

Welcome New Member


On Farm Irrigation - The Shift From Art To Science, Charles M. Burt May 1998

On Farm Irrigation - The Shift From Art To Science, Charles M. Burt

BioResource and Agricultural Engineering

Excellent on-farm irrigation management and design have traditionally been promoted for reasons of improved yields and farm input costs. More recently, external pressures require even more detail to on-farm irrigation. These external pressures include competition for water by urban and environmental interests, plus degradation of aquifers and rivers. As irrigation progresses from an art to a science, new concepts must be adopted. Key points made in the paper relate to flexible water deliveries to farms, improved fertigation practices, the importance of on-farm irrigation evaluations, the use of an Irrigation Consumer Bill of Rights by dealers and farmers, and irrigation system …


The Effect Of Nonvertical Shear On Turbulence In A Stably Stratified Medium, Frank G. Jacobitz, Sutanu Sarkar May 1998

The Effect Of Nonvertical Shear On Turbulence In A Stably Stratified Medium, Frank G. Jacobitz, Sutanu Sarkar

School of Engineering: Faculty Scholarship

Direct numerical simulations were performed in order to investigate the evolution of turbulence in a stably stratified fluid forced by nonvertical shear. Past research has been focused on vertical shear flow, and the present work is the first systematic study with vertical and horizontal components of shear. The primary objective of this work was to study the effects of a variation of the angle θ between the direction of stratification and the gradient of the mean streamwise velocity from θ=0, corresponding to the well-studied case of purely vertical shear, to θ=π/2,corresponding to purely horizontal shear. It was observed that the …


Analysis Of Combustion-Driven Acoustics, Leonie Boshoff-Mostert, Hendrik J. Viljoen May 1998

Analysis Of Combustion-Driven Acoustics, Leonie Boshoff-Mostert, Hendrik J. Viljoen

Papers in Reaction Kinetics

Combustion-driven acoustic oscillations are investigated by performing a onedimensional stability analysis of a burner-stabilized premixed flame. In contrast to other investigators, no initial acoustic wave is assumed in the analysis; the downstream acoustic field results from flame instability. Two models are considered: the thermodiffusive model (uncoupled model) and the fully coupled thermodiffusive-hydrodynamic model. The fully coupled problem exhibits instability at a much lower critical Lewis number than the uncoupled problem.


Standards And Verification Protocols For Commissioning Air Flows In Buildings, Florida Solar Energy Center, James Cummings May 1998

Standards And Verification Protocols For Commissioning Air Flows In Buildings, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Commissioning involves three major elements - 1) process, 2) standards, and 3) protocols to verify compliance with the standards. Process is the step-by-step oversight of and involvement in the design, build, and start-up of the facility, to make sure that the design matches the customer's needs, that the design is consistent with good building science practice, that construction matches the construction documents, and that systems and system interactions are properly tested at start-up. This paper does not address process, rather it focuses on the second and third elements -- standards and compliance protocols. It presents standards related to airtightness, air …


Adaptation Space: Surviving Non-Maskable Failures, Crispin Cowan, Lois Delcambre, Anne-Francoise Le Meur, Ling Liu, David Maier, Dylan Mcnamee, Michael Miller, Calton Pu, Perry Wagle, Jonathan Walpole May 1998

Adaptation Space: Surviving Non-Maskable Failures, Crispin Cowan, Lois Delcambre, Anne-Francoise Le Meur, Ling Liu, David Maier, Dylan Mcnamee, Michael Miller, Calton Pu, Perry Wagle, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Some failures cannot be masked by redundancies, because an unanticipated situation occurred, because fault-tolerance measures were not adequate, or because there was a security breach (which is not amenable to replication). Applications that wish to continue to offer some service despite nonmaskable failure must adapt to the loss of resources. When numerous combinations of non-maskable failure modes are considered, the set of possible adaptations becomes complex. This paper presents adaptation spaces, a formalism for navigating among combinations of adaptations. An adaptation space describes a collection of possible adaptations of a software component or system, and provides a uniform way of …


Three-Bladed Propeller Design For The Reduction Of General Aviation Radiated Noise Characteristics, Ronald W. Finn May 1998

Three-Bladed Propeller Design For The Reduction Of General Aviation Radiated Noise Characteristics, Ronald W. Finn

Master's Theses - Daytona Beach

The purpose of this study was to design a quiet 3-Bladed propeller for general aviation aircraft. A combination of design technique and analytical predictions using the NASA Aircraft Noise Prediction Program - Propeller Analysis System (ANOPP-PAS) was used to achieve this goal. The propellers were designed for an engine power of 200 hp, a rotational speed of 2,400 RPM and a free-stream speed of 160 kts. A straight 76 in. diameter 2-bladed propeller was designed as a reference for the 64 in. diameter 3-bladed propeller. The ANOPP-PAS computer code was used for predicting the aerodynamic performance and radiated noise characteristics …


The Political Psychology Of Air Shows: Strata Of Mass Rally, Pageantry, And Spectacle, Ibpp Editor May 1998

The Political Psychology Of Air Shows: Strata Of Mass Rally, Pageantry, And Spectacle, Ibpp Editor

International Bulletin of Political Psychology

This article describes the psychology of air shows' attractiveness and suggests the congruence of this psychology with the attractiveness of mass political rally, pageantry, and spectacle.


Diffuse Reflectance Changes During The Culture Of Cottage Cheese, Frederick Alan Payne, R. Carol Freels, Sue E. Nokes, Richard S. Gates May 1998

Diffuse Reflectance Changes During The Culture Of Cottage Cheese, Frederick Alan Payne, R. Carol Freels, Sue E. Nokes, Richard S. Gates

Biosystems and Agricultural Engineering Faculty Publications

A sensor for measuring diffuse reflectance of milk during the typical 6-h culture of cottage cheese was installed in a local manufacturing facility. Diffuse reflectance was found to increase slowly during the first three hours of the culture and increase rapidly toward the end of fermentation. The correlation between parameters generated from the diffuse reflectance profile and cutting time was sufficient to develop an algorithm for cutting time prediction. An algorithm incorporating tmax (time from adding culture to the maximum rate of change in reflectance) and slope of the reflectance curve at tmax predicted the operator selected cutting …


The Columbia River Plume Study: Subtidal Variability In The Velocity And Salinity Fields, B. M. Hickey, Leonard J. Pietrafesa, David A. Jay, William C. Boicourt May 1998

The Columbia River Plume Study: Subtidal Variability In The Velocity And Salinity Fields, B. M. Hickey, Leonard J. Pietrafesa, David A. Jay, William C. Boicourt

Civil and Environmental Engineering Faculty Publications and Presentations

A comprehensive study of the strongly wind driven midlatitude buoyant plume from the Columbia River, located on the U.S. west coast, demonstrates that the plume has two basic structures during the fall/winter season, namely, a thin (~5~15 m), strongly stratified plume tending west to northwestward during periods of southward or light northward wind stress and a thicker (~10~40 m), weakly stratified plume tending northward and hugging the coast during periods of stronger northward stress. The plume and its velocity field respond nearly instantaneously to changes in wind speed or direction, and the wind fluctuations have timescales of 2-10 days. Frictional …


Design Of The Guidance, Navigation, And Control Subsystem For The Proposed Firebird Spacecraft, Erin Robinson May 1998

Design Of The Guidance, Navigation, And Control Subsystem For The Proposed Firebird Spacecraft, Erin Robinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Firebird spacecraft is a space mission to gather scientific and physical data on the effects of atmospheric deceleration, commonly called aerobraking. The objective of the Firebird mission is to measure specified aerobraking parameters over a range of reentry velocities to provide a database sufficient to construct and validate mathematical models of such aerobraking mission maneuvers. The Firebird senior design team designed the first spacecraft in the mission series to look at aerobraking at an altitude of 160 kilometers above the surface of the Earth. This paper looks specifically at the design of the subsystem that provides the guidance, navigation, …


Kinetics Of Phase Transition In An Anticlinic Liquid Crystal Induced By A Uniform Temperature Field: Growth In One Dimension, X. Y. Wang, Jian-Feng Li, Eliezer Gurarie, S. Fan, Thein Kyu, S. S. Keast, Charles Rosenblatt May 1998

Kinetics Of Phase Transition In An Anticlinic Liquid Crystal Induced By A Uniform Temperature Field: Growth In One Dimension, X. Y. Wang, Jian-Feng Li, Eliezer Gurarie, S. Fan, Thein Kyu, S. S. Keast, Charles Rosenblatt

College of Polymer Science and Polymer Engineering

It is experimentally demonstrated that a transition from a synclinic to an anticlinic liquid crystal phase occurs via stable domain wall propagation after quenching in a uniform temperature field. Such a one-dimensional growth may be explained in terms of a nonlinear diffusion equation. The experiment provides the first example of free, one-dimensional growth in a system subjected to a pure and uniform temperature field.


Quantification Of Mitral Regurgitation With Mr Phase-Velocity Mapping Using A Control Volume Method, George P. Chatzimavroudis, John N. Oshinski, Roderic I. Pettigrew, Peter G. Walker, Robert H. Franch, Ajit P. Yoganathan May 1998

Quantification Of Mitral Regurgitation With Mr Phase-Velocity Mapping Using A Control Volume Method, George P. Chatzimavroudis, John N. Oshinski, Roderic I. Pettigrew, Peter G. Walker, Robert H. Franch, Ajit P. Yoganathan

Chemical & Biomedical Engineering Faculty Publications

Reliable diagnosis and quantification of mitral regurgitation are important for patient management and for optimizing the time for surgery. Previous methods have often provided suboptimal results. The aim of this in vitro study was to evaluate MR phase-velocity mapping in quantifying the mitral regurgitant volume (MRV) using a control volume (CV) method. A number of contiguous slices were acquired with all three velocity components measured. A CV was then selected, encompassing the regurgitant orifice. Mass conservation dictates that the net inflow into the CV should be equal to the regurgitant flow. Results showed that a CV, the boundary voxels of …


Intelligent Transportation Systems Strategic Plan (Phase I Report), Joseph D. Crabtree, Ted H. Grossardt, Donald G. Hartman, Jerry G. Pigman, Jennifer R. Walton, Joel M. Weber, Study Advisory Committee May 1998

Intelligent Transportation Systems Strategic Plan (Phase I Report), Joseph D. Crabtree, Ted H. Grossardt, Donald G. Hartman, Jerry G. Pigman, Jennifer R. Walton, Joel M. Weber, Study Advisory Committee

Kentucky Transportation Center Research Report

This interim report on an Intelligent Transportation Systems Strategic (ITS) Plan has been developed as documentation of the process of offering a vision for ITS and recommending an outline for organizational structure, infrastructure, and long-term planning for ITS in Kentucky. This plan provides an overview of the broad scope of ITS and relationships between various Intelligent Vehicle Highway Systems (IVHS) functional areas and ITS user service areas. Three of the functional areas of ITS have been addressed in this interim report with sections devoted to mission, vision, goals, and potential technology applications. Within each of the three areas, recommendations have …


Seismic Isolation Of A Highly Skewed, Prestressed Concrete Girder Bridge, Bradley Neil Robson, Issam E. Harik, David L. Allen May 1998

Seismic Isolation Of A Highly Skewed, Prestressed Concrete Girder Bridge, Bradley Neil Robson, Issam E. Harik, David L. Allen

Kentucky Transportation Center Research Report

A relatively new approach for designing or retrofitting highway bridges in seismic zones involves isolating the superstructure from the substructure. Through experimental and analytical investigations, this study evaluates the effectiveness of isolating one particular bridge: a highly skewed, prestressed concrete, slab-on-girder bridge. Dynamic testing of the bridge was performed using the pullback, quick-release method. A three dimensional finite element model of the bridge was created. It was refined, or calibrated, to match experimentally determined natural frequencies and mode shapes. Time-history analyzes, using site-specific acceleration records, were conducted for the seismically isolated bridge model and an identical, non-isolated bridge model.

For …


Implementation Of A Database System With Boolean Algebra Constraints, András Salamon May 1998

Implementation Of A Database System With Boolean Algebra Constraints, András Salamon

School of Computing: Dissertations, Theses, and Student Research

This thesis describes an implementation of a constraint database system with constraints over a Boolean Algebra of sets. The system allows within the input database as well as the queries equality, subset-equality and monotone inequality constraints between Boolean Algebra terms built up using the operators of union, intersection and complement. Hence the new system extends the earlier DISCO system, which only allowed equality and subset-equality constraints between Boolean algebra variables and constants. The new system allows Datalog with Boolean Algebra constraints as the query lan- guage. The implementation includes an extension of Naive and Semi-Naive evaluation methods for Datalog programs …


Investigating Performance Of Bonded Concrete Overlays, Norbert J. Delatte, David W. Fowler, B. Frank Mccullough, Stefan F. Gräter May 1998

Investigating Performance Of Bonded Concrete Overlays, Norbert J. Delatte, David W. Fowler, B. Frank Mccullough, Stefan F. Gräter

Civil and Environmental Engineering Faculty Publications

A bonded concrete overlay (BCO) is a concrete pavement rehabilitation method used to extend the life of an existing concrete pavement. The BCO should bond fully with the existing concrete, leading to a thicker composite pavement section, a much stiffer pavement, and a considerable decrease in pavement stresses. For one project, cost estimates for a BCO were half as much as for full-depth replacement of a pavement. In some cases BCOs have delaminated shortly after construction. This paper proposes a framework for identifying the causes of early age delamination in BCOs. The early age behavior of newly constructed BCOs is …


Mechanical Properties Of The Tendinous Equine Interosseus Muscle Are Affected By In Vivo Transducer Implantation, M. O. Jansen, H. C. Schamhardt, Antonie J. Van Den Bogert, W. Hartman May 1998

Mechanical Properties Of The Tendinous Equine Interosseus Muscle Are Affected By In Vivo Transducer Implantation, M. O. Jansen, H. C. Schamhardt, Antonie J. Van Den Bogert, W. Hartman

Mechanical Engineering Faculty Publications

Liquid metal strain gauges (LMSGs) were implanted in the tendinous interosseous muscle, also called suspensory ligament (SL), in the forelimbs of 6 ponies in order to quantify in vivo strains and forces. Kinematics and ground reaction forces were recorded simultaneously with LMSG signals at the walk and the trot prior to implantation, and 3 and 4 days thereafter. The ponies were euthanised and tensile and failure tests were performed on the instrumented tendons and on the tendons of the contra lateral limb, which were instrumented post mortem. The origo–insertional (OI) strain of the SL was computed from pre- and post-operative …