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Articles 170431 - 170460 of 198087

Full-Text Articles in Engineering

On The Detachment Of Step-Tapered Doublers : Part 1—Foundations, W. J. Bottega, Anette M. Karlsson Apr 1999

On The Detachment Of Step-Tapered Doublers : Part 1—Foundations, W. J. Bottega, Anette M. Karlsson

Mechanical Engineering Faculty Publications

One-dimensional edge debonding of layerwise step-tapered patches from both flat and cylindrical structures is examined. The problems are approach from a unified point of view, as propagating boundary problems in the calculus of variations, with the models for both flat and curved structures being formulated simultaneously. The effects of a contact zone adjacent to the bonded region are incorporated as is the phenomenon of edge-point contact. The formulation results in a selfconsistent representation of the various intact and debonded segments of the composite structure comprised of a multilayer patch and a base structure. It concurrently yields the conditions which establish …


Reduction Of Helmet Buffeting In Open Cockpit, Single Seat Race Cars, Mark Vallon Apr 1999

Reduction Of Helmet Buffeting In Open Cockpit, Single Seat Race Cars, Mark Vallon

Master's Theses - Daytona Beach

At speeds approaching 240 mph, drivers of open cockpit race cars frequently experience large aerodynamic forces which act on the helmet. These forces, specifically the aerodynamic buffeting of the helmet, reach levels which are very fatiguing and distracting to the driver, and are therefore unacceptable. Little investigation has been done in this area, because normal wind tunnel tests do not isolate the helmet from the rest of the car. During this project, measurements of aerodynamic forces acting on a helmet inside a race car cockpit were made to determine the cause of the buffeting, and to determine possible improvements.

Tests …


Cracking In Cycloaliphatic Epoxy/Aluminum Composite Electrical Bushings, Keith Alan Parker Apr 1999

Cracking In Cycloaliphatic Epoxy/Aluminum Composite Electrical Bushings, Keith Alan Parker

Doctoral Dissertations

The problem of cracking in electrical apparatus bushings as a result of thermal stresses was investigated. The bushings were composed of cycloaliphatic epoxy insulators with embedded aluminum conductors. The problem is due to the difference in coefficients of thermal expansion of the two materials. A solution to the problem had been to coat the conductors before they were formed together with the epoxy insulators. The coating was assumed to prevent cracking by allowing movement between the two materials as their dimensions changed during thermal expansion and contraction. The contribution of the coating was to be established.

The hypothesis was that …


Graphical Display And Data Structure For Virtual Prototyping, David William Manry Apr 1999

Graphical Display And Data Structure For Virtual Prototyping, David William Manry

Doctoral Dissertations

One of the goals of engineering firms is to bring better products to market faster. Although concurrent engineering can aid in this endeavor, it requires that all areas of an organization work simultaneously. Thus, current product data must be accessible to everyone.

Virtual prototyping allows this simultaneous exchange of information. Virtual prototyping not only replaces the physical model in product development with a virtual model, but also it goes further by allowing data associated with each part of the model to be accessed. This data is not limited to just geometric properties but could contain other quantifiable properties, such as …


Comprehensive Analysis Of Edge Detection In Color Image Processing, Shu-Yu Zhu, Konstantinos N. Kostas Plataniotis, Anastasios N. Venetsanopoulos Apr 1999

Comprehensive Analysis Of Edge Detection In Color Image Processing, Shu-Yu Zhu, Konstantinos N. Kostas Plataniotis, Anastasios N. Venetsanopoulos

Electrical Engineering and Computer Science Faculty Publications

Various approaches to edge detection for color images, including techniques extended from monochrome edge detection as well as vector space approaches, are examined. In particular, edge detection techniques based on vector order statistic operators and difference vector operators are studied in detail. Numerous edge detectors are obtained as special cases of these two classes of operators. The effect of distance measures on the performance of different color edge detectors is studied by employing distance measures other than the Euclidean norm. Variations are introduced to both the vector order statistic operators and the difference vector operators to improve noise performance. They …


An Investigation Into The Skills Needed For The Workforce In The Year 2005 For Midwest Manufacturing, George A. Ritland Apr 1999

An Investigation Into The Skills Needed For The Workforce In The Year 2005 For Midwest Manufacturing, George A. Ritland

Graduate Research Papers

The purpose of this study was to define the collaborative skills identified by John Deere and provide the personnel who are involved in the hiring process at John Deere those results in order to assist them in evaluating potential employees for employment in the year 2005.


On-Line Free Form Surface Measurement Via A Fuzzy-Logic Controlled Scanning Probe, Ming Chang, Paul P. Lin Apr 1999

On-Line Free Form Surface Measurement Via A Fuzzy-Logic Controlled Scanning Probe, Ming Chang, Paul P. Lin

Mechanical Engineering Faculty Publications

This paper presents a system and methodology for on-line free form surface measurement via a scanning contact probe installed on a CNC (computer numerical control) machine. The scanning probe provides more sampling points than any traditional touch trigger type of probes used on CNC machines, and better measuring accuracy than laser displacement sensing or structured lighting. The presented measuring system's main advantage is that the number of measured points can vary with the change of surface curvature. To improve the measuring stability and continuity, fuzzy logic control, in lieu of traditional PID control, is employed. As a result, the …


Frequency Driven Phasic Shifting And Elastic-Hysteretic Partitioning Properties Of Fractional Mechanical System Representation Schemes, Jerzy T. Sawicki, Joe Padovan Apr 1999

Frequency Driven Phasic Shifting And Elastic-Hysteretic Partitioning Properties Of Fractional Mechanical System Representation Schemes, Jerzy T. Sawicki, Joe Padovan

Mechanical Engineering Faculty Publications

Based on the Louiville–Riemann fractional formulation of lumped hysteretic mechanical system simulations, asymptotic-type relationships are derived. These are employed to determine how such operators, which act as viscoelastic elements, partition system energy into conservative and nonconservative components. Special emphasis is given to: (a) determine how operator order serves to weigh such a splitting, (b) determine how partitioning affects system phasing and amplitude response, and (c) to establish how conservative and nonconservative effects modulate during a given system cycle. The generality of the undertaken approach is such that multi-element fractional Kelvin Voigt formulations subject to spectrally rich inputs can be handled, …


Routing And Scheduling I/O Transfers On Wormhole-Routed Mesh Networks, Bhagirath Narahari, Sunil Shende, Rahul Simha, S. R. Subramanya Apr 1999

Routing And Scheduling I/O Transfers On Wormhole-Routed Mesh Networks, Bhagirath Narahari, Sunil Shende, Rahul Simha, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

This paper studies the problem of routing and scheduling parallel I/O operations to minimize the time required to transfer data between processors and I/O devices. In particular, a 2-dimensional mesh architecture is considered in which routing is performed using wormhole switching and I/O nodes are placed on the periphery of the mesh. Two broad classes of data transfer mechanisms are examined: schedules with blocking (SB), in which packets may be temporarily blocked during transit, and schedules with no blocking (SNB), in which packets are never blocked in the network. For both classes, optimal scheduling is shown to be NP-complete, and …


Relationship Between Cost Of Technical Training And Cost Reduction Of Internal Defects At John Deere Waterloo Foundry, John Brackin Apr 1999

Relationship Between Cost Of Technical Training And Cost Reduction Of Internal Defects At John Deere Waterloo Foundry, John Brackin

Graduate Research Papers

Can the cost of technical training at John Deere Waterloo Foundry pay for itself in the reduction of internal defects? This research compared training costs to the savings from reduced internal defects on Molding Unit 801 located in the John Deere Waterloo Foundry. Training was the independent variable of this research. The results of this research identified a correlation between training costs ( operational definition on page 10) and defect reduction costs. A correlation between these two established a break even point for training dollars spent.

The dependent variable was the dollar savings based on reduction of internal defects. There …


Three Reasons To Broaden Your Fertigation Knowledge, Charles M. Burt Apr 1999

Three Reasons To Broaden Your Fertigation Knowledge, Charles M. Burt

BioResource and Agricultural Engineering

No abstract provided.


Bs News Apr 1999

Bs News

Building Services Engineering

No abstract provided.


1999 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department Apr 1999

1999 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the spring of 1999.


Interval Matching And Control For Hexahedral Mesh Generation Of Swept Volumes, Jason F. Shepherd Apr 1999

Interval Matching And Control For Hexahedral Mesh Generation Of Swept Volumes, Jason F. Shepherd

Theses and Dissertations

Surface meshing algorithms require certain relationships among the number of intervals on the curves that bound the surface. Assigning the number of intervals to all of the curves in the model such that all relationships are satisfied is called interval assignment. Volume meshing algorithms also require certain relationships among the numbers of intervals on each of the curves on the volume. These relationships are not always captured by surface meshing requirements. This thesis presents a news technique for automatically identifying volume constraints. In this technique, volume constraints are grouped with surface constraints and are solved simultaneously. A sweepable volume has …


Magnetic And Mössbauer Spectral Study Of Mixed Valent La₀.₂Sr₀.₈Cu₀.₂Fe₀.₈O2.68 And Related Perovskites, Gary J. Long, Dimitri Hautot, Amitabh Mohan, Ingeborg Kaus, Harlan U. Anderson, Fernande Grandjean Apr 1999

Magnetic And Mössbauer Spectral Study Of Mixed Valent La₀.₂Sr₀.₈Cu₀.₂Fe₀.₈O2.68 And Related Perovskites, Gary J. Long, Dimitri Hautot, Amitabh Mohan, Ingeborg Kaus, Harlan U. Anderson, Fernande Grandjean

Chemistry Faculty Research & Creative Works

The La0.2Sr0.8Cu1-xFexO 3-δ perovskites are important because they are mixed electron and oxygen anion conductors and thus are able to serve as dense oxygen separation membranes. In order to better understand the mechanism for this separation a Mössbauer spectral study has been carried out to determine the ratio of iron(III) to iron(IV) in these mixed valent compounds. The Mössbauer spectra of La0.2Sr0.8Cu0.2Fe0.8O 3-δ obtained between 4.2 and 78 K reveal that its Néel temperature is ~75 K and the two well-resolved magnetic sextets observed …


Preparation And Surface Studies Of Negative Electron Affinity Semiconductors Photocathodes, Khaled A. Elamrawi Apr 1999

Preparation And Surface Studies Of Negative Electron Affinity Semiconductors Photocathodes, Khaled A. Elamrawi

Electrical & Computer Engineering Theses & Dissertations

Fabrication of high quantum efficiency, long lifetime negative electron affinity photocathodes is important for applications such as photomultipliers, image intensifiers, electron beam lithography, electron microscopy, and polarized electron sources. The surface cleanliness of the III-V semiconductor photocathode is crucial in obtaining high photosensitivity.

GaAs(100) and InP(100) photocathodes are prepared by atomic hydrogen cleaning. The cleaning effect on the photocathode performance is discussed. The surface degradation mechanisms which reduce the photocathode lifetime are presented. The photocathode surface cleanliness, structure, and morphology are studied using reflection high-energy electron diffraction (RHEED).

Quantum efficiencies of ∼14% and 8% are obtained for GaAs and InP, …


Evaluation Of Lead Anode Reactions In Acid Sulfate Electrolytes. I. Lead Alloys With Cobalt Additives, Pu Yu, Thomas J. O'Keefe Apr 1999

Evaluation Of Lead Anode Reactions In Acid Sulfate Electrolytes. I. Lead Alloys With Cobalt Additives, Pu Yu, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

Lead alloys, such as lead-calcium-tin and lead-silver, are the primary insoluble anodes used in the electrowinning of metals. While some difficulties are encountered in their use, there is no obvious replacement that is economically and technically competitive. Two of the specific problems with lead include decreased cathode purity due to incorporation from corrosion products and the relatively high overpotential which increases cell voltage. To gain an improved understanding of the fundamental behavior of lead anodes, the polarization behavior of six different alloys in sulfuric acid was evaluated. Some tests were also made with Co(II) in the acid sulfate electrolyte. Notable …


Multifield Spectral Analysis Of Human Respiratory Sounds, John William Ray Jr. Apr 1999

Multifield Spectral Analysis Of Human Respiratory Sounds, John William Ray Jr.

Doctoral Dissertations

Computer analysis of human respiratory sounds (phonopneumography) has been attempted since the 1960s with poor results. Steady research efforts by numerous researchers have failed to yield a practical diagnostic tool to replace the physician and the stethoscope. This has been the result of the high degree of variability in proposed analysis parameters from subject to subject.

The purpose of this research is to examine a new approach to phonopneumography by comparing multiple lung fields of the same subject for the same breath in order to develop the diagnostic parameters. This approach has the advantage of allowing the subject to provide …


The Use Of Recombinant Human Bone Morphogenetic Protein 2 (Rhbmp-2) To Promote Spinal Fusion In A Nonhuman Primate Anterior Interbody Fusion Model, Brian P. Hecht, Jeffrey S. Fischgrund, Harry N. Harkowitz, Lori Penman, Jeffrey M. Toth, Ali Shirkhoda Apr 1999

The Use Of Recombinant Human Bone Morphogenetic Protein 2 (Rhbmp-2) To Promote Spinal Fusion In A Nonhuman Primate Anterior Interbody Fusion Model, Brian P. Hecht, Jeffrey S. Fischgrund, Harry N. Harkowitz, Lori Penman, Jeffrey M. Toth, Ali Shirkhoda

Biomedical Engineering Faculty Research and Publications

Study Design. A study on the efficacy of recombinant human bone morphogenetic protein 2 (rhBMP-2) in a nonhuman primate anterior interbody fusion model.

Objectives. To investigate the efficacy of rhBMP-2 with an absorbable collagen sponge carrier to promote spinal fusion in a nonhuman primate anterior interbody fusion model.

Summary of Background Data. RhBMP-2 is an osteoinductive growth factor capable of inducing new bone formation in vivo. Although dosage studies using rhBMP-2 have been performed on species of lower phylogenetic level, they cannot be extrapolated to the primate. Dosage studies on nonhuman primates are essential before proceeding with human primate application. …


Destructive And Non-Destructive Testing Of Bridge J857 Phelps County, Missouri : Strengthening And Testing To Failure Of Bridge Decks, Tarek Alkhrdaji, Antonio Nanni, Genda Chen, Michael G. Barker Apr 1999

Destructive And Non-Destructive Testing Of Bridge J857 Phelps County, Missouri : Strengthening And Testing To Failure Of Bridge Decks, Tarek Alkhrdaji, Antonio Nanni, Genda Chen, Michael G. Barker

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Concrete bridges are conventionally reinforced with steel bars and/or prestressed with steel tendons. When subjected to aggressive environments, corrosion of the reinforcing and prestressing steel occurs and eventually leads to premature structural deterioration and loss of serviceability. In addition, the increasing service loads as well as seismic upgrade requirements result in a need to strengthen many of these bridges. The use of externally bonded steel plates for flexural and shear strengthening of concrete members is well established. However, corrosion related problems have limited the use of this technique for outdoor application. Fiber reinforced polymer (FRP) composites are corrosion resistant and …


Pavement Design Guide: A Short Course, Kentucky Transportation Center Apr 1999

Pavement Design Guide: A Short Course, Kentucky Transportation Center

Kentucky Transportation Center Research Report

The purpose of this short course is to provide information to the registered engineer (with no previous background in pavement design or pavement technology) on the structural design of pavements. Included in this course is a summary of background information on the materials used in pavement construction and on the history and evolution of pavement design. Included with this course is an updated Design Guide or catalog to be used for designing new pavements in Kentucky. The intent of the guide or catalog is to provide the road\\ a) designer with a simplified, straightforward methodology for developing structural designs of …


Truck Route Access Evaluation: Dravo Lime Company, Maysville, Site #30, Joel M. Weber, Kenneth R. Agent, Brian Aldridge, Lisa Aultman-Hall, David Cain, Nikiforos Stamatiadis Apr 1999

Truck Route Access Evaluation: Dravo Lime Company, Maysville, Site #30, Joel M. Weber, Kenneth R. Agent, Brian Aldridge, Lisa Aultman-Hall, David Cain, Nikiforos Stamatiadis

Kentucky Transportation Center Research Report

This is a study undertaken by the Kentucky Transportation Center on behalf of the Kentucky Transportation Cabinet ( KYTC). There are two main objectives of the Freight Movement and Intermodal Access in Kentucky Study (SPR 98-189): evaluation of the access for trucks between intermodal or other truck generating sites and the National Highway System (NHS); and furthering the understanding of freight commodity flows throughout the state. This report summarizes the access evaluation for the Dravo Lime Company facility located in Mason County in the Buffalo Trace Area Development District (ADD) and KYTC Highway District #9. The location of the site …


Truck Route Access Evaluation: Willamette Industries, Hancock County, Site #2659, Brian Aldridge, Kenneth R. Agent, Lisa Aultman-Hall, David Cain, Nikiforos Stamatiadis, Joel M. Weber Apr 1999

Truck Route Access Evaluation: Willamette Industries, Hancock County, Site #2659, Brian Aldridge, Kenneth R. Agent, Lisa Aultman-Hall, David Cain, Nikiforos Stamatiadis, Joel M. Weber

Kentucky Transportation Center Research Report

The Freight Movement and lntermodal Access in Kentucky Study (SPR 98-189), undertaken by the Kentucky Transportation Center (KTC) on behalf of the Kentucky Transportation Cabinet (KYTC), has two main objectives. These objectives include 1) the evaluation of access for trucks between intermodal or other truck generating sites and the National Highway System (NHS) and 2) furthering the understanding of freight commodity flows throughout the state. This report summarizes the access evaluation for one facility located in Hancock County in the Green River Area Development District (ADD) and KYTC (Kentucky Transportation Cabinet) Highway District #2. The location of the site is …


Truck Route Access Evaluation: Westvaco Corporation, Ballard County, Site #2683, Brian Aldridge, Kenneth R. Agent, Lisa Aultman-Hall, David Cain, Nikiforos Stamatiadis, Joel M. Weber Apr 1999

Truck Route Access Evaluation: Westvaco Corporation, Ballard County, Site #2683, Brian Aldridge, Kenneth R. Agent, Lisa Aultman-Hall, David Cain, Nikiforos Stamatiadis, Joel M. Weber

Kentucky Transportation Center Research Report

The Freight Movement and Intermodal Access in Kentucky Study (SPR 98-189), undertaken by the Kentucky Transportation Center (KTC) on behalf of the Kentucky Transportation Cabinet (KYTC), has two main objectives. These objectives include 1) the evaluation of access for trucks between intermodal or other truck generating sites and the National Highway System (NHS) and 2) furthering the understanding of freight commodity flows throughout the state. This report summarizes the access evaluation for one facility located in Ballard County in the Purchase Area Development District (ADD) and KYTC (Kentucky Transportation Cabinet) Highway District #1. The location of the site is shown …


Information Modeling And Method Engineering: A Psychological Perspective, Keng Siau Apr 1999

Information Modeling And Method Engineering: A Psychological Perspective, Keng Siau

Research Collection School Of Computing and Information Systems

Information modeling is the cornerstone of information systems analysis and design. Information models, the products of information modeling, not only provide the abstractions required to facilitate communication between the analysts and end users, but they also provide a formal basis for developing tools and techniques used in information systems development. The process of designing, constructing, and adapting information modeling methods for information systems development is known as method engineering. Despite the pivotal role of modeling methods in successful information systems development, most modeling methods are designed based on common sense and intuition of the method designers with little or no …


Aeroelastic Load Alleviation Using Shunted Piezolectrics, Anna-Maria Rivas Mcgowan Apr 1999

Aeroelastic Load Alleviation Using Shunted Piezolectrics, Anna-Maria Rivas Mcgowan

Mechanical & Aerospace Engineering Theses & Dissertations

Several analytical and experimental studies clearly demonstrate that piezoelectric materials (piezoelectrics) can be used as actuators to actively control vibratory response including aeroelastic response. However, two important issues in using piezoelectrics as actuators for active control are: 1) the potentially large amount of power required to operate the actuators, and 2) the complexities involved with active control (added hardware, control law design and implementation). Active or passive damping augmentation using shunted piezoelectrics may provide a viable alternative. This approach requires only simple electrical circuitry and very little or no electrical power. Shunted piezoelectrics have been shown to provide an efficient …


Assessment Of A Higher Harmonic Control System For Minimizing Vibrations On A Dynamically Scaled Tiltrotor Model, David J. Piatak Apr 1999

Assessment Of A Higher Harmonic Control System For Minimizing Vibrations On A Dynamically Scaled Tiltrotor Model, David J. Piatak

Mechanical & Aerospace Engineering Theses & Dissertations

The performance of a higher harmonic control system called the Multipoint Adaptive Vibration Suppression System (MA VSS) at reducing 3/rev wing vibratory loads and fuselage vibrations on a dynamically-scaled tiltrotor model is presented. Previous wind tunnel tests on a semispan aeroelastic tiltrotor model have demonstrated the effectiveness of MAVSS for reducing wing vibratory loads using both an active flaperon and swashplate. The primary goal, however, of such a vibration suppression system is to reduce tiltrotor fuselage vibrations in order to improve passenger comfort. The present study addresses the reduction of both wing and fuselage vibrations using MA VSS active flaperons …


An Experimental Investigation Into The Effect Of Clearance And Torque On Load Sharing In A Bolted Joint, Jerry B. Robertson Apr 1999

An Experimental Investigation Into The Effect Of Clearance And Torque On Load Sharing In A Bolted Joint, Jerry B. Robertson

Mechanical & Aerospace Engineering Theses & Dissertations

The shear load experienced by each bolt in a multi-fastener bolted butt joint is a percentage of the total load applied to the joint. Joint failure can be premature when one fastener is subjected to a disproportional amount of the total load. Conversely, the ultimate load the joint can endure may be increased if the distribution of loads can be equalized by some means. In this investigation, two and four fastener butt joints were studied. An instrumented bolt was constructed that could measure the bending stresses in the bolt associated with the bearing load. That data was converted into force …


Development And Testing Of An Ac Micro Hollow Cathode Simulator, Thomas E. Caldwell Apr 1999

Development And Testing Of An Ac Micro Hollow Cathode Simulator, Thomas E. Caldwell

Electrical & Computer Engineering Theses & Dissertations

The use of AC source plasma discharge devices in applications such as material processing and film deposition has increased in recent years due to improvements in discharge efficiency made possible by devices such as the micro hollow cathode. Designing hollow cathodes for specific applications requires an understanding of the processes that govern the discharge. Simulation is an inexpensive tool for understanding hollow cathode operation and optimizing the device for specific applications. This thesis describes the development of an AC micro hollow cathode simulator. It details the theoretical models used in the simulation and presents the results of test cases intended …


Development Of Baseline Water Quality Stormwater Detention Pond Model For Chesapeake Bay Catchments, William J. Musico Apr 1999

Development Of Baseline Water Quality Stormwater Detention Pond Model For Chesapeake Bay Catchments, William J. Musico

Civil & Environmental Engineering Theses & Dissertations

A stormwater detention pond model, EEMD (Environmentally Economic Management Design), was developed using VisualBasic to facilitate the design of extended detention basins. A detention basin is a design such that a site's stormwater runoff would meet certain environmental impact requirements. To ensure these environmental requirements are meet the Commonwealth of Virginia subscribes to the procedures outlined by the Chesapeake Bay Local Assistance Department (CBLAD).

The purpose of the Chesapeake Bay Local Assistance Department (CBLAD) Calculation Procedures is to ensure that the development of constructed areas do not further exacerbate current problems of stormwater-induced eutrophication and downstream flooding. The methodology is …