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Articles 67201 - 67230 of 75094

Full-Text Articles in Engineering

Darcy-Weisbach Roughness Coefficients For Gravel And Cobble Surfaces, John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman Feb 1992

Darcy-Weisbach Roughness Coefficients For Gravel And Cobble Surfaces, John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A laboratory study is conducted to measure Darcy-Weisbach roughness coefficients for selected gravel and cobble materials. Varying rates of flow are introduced into a flume in which a given size class of gravel or cobble material is securely attached. Roughness coefficients are calculated from measurements of discharge rate and flow velocity. The laboratory data are used to develop regression equations for relating roughness coefficients to surface cover and Reynolds number. The regression relations, which are developed for values of the Reynolds number from approximately 500 to 16,000, are tested using hydraulic data collected on surfaces containing a distribution of size …


Transient Stability Test Systems For Direct Stability Methods, V. Vittal, D Martin, R Chu, J Fish, J C. Giri, C K. Tang, F. Eugenio Villaseca, R G. Farmer Feb 1992

Transient Stability Test Systems For Direct Stability Methods, V. Vittal, D Martin, R Chu, J Fish, J C. Giri, C K. Tang, F. Eugenio Villaseca, R G. Farmer

Electrical and Computer Engineering Faculty Publications

A standard set of power system data with benchmark results are presented against which direct stability techniques to assess transient stability can be compared and tested. The test systems have been selected to display a wide range of dynamic characteristics to provide a robust test of the efficacy and accuracy of the various analytical techniques to analyze transient stability. Transient stability test system data and benchmark results obtained from two commercially available time-domain stability analysis packages are presented


Determining The Chemical Composition Of Cloud Condensation Nuclei, Allen L. Williams, Jane E. Rothert, Kent E. Mcclure, Darryl J. Alofs, Donald E. Hagen, Daniel R. White, A. R. Hopkins, Max B. Trueblood Feb 1992

Determining The Chemical Composition Of Cloud Condensation Nuclei, Allen L. Williams, Jane E. Rothert, Kent E. Mcclure, Darryl J. Alofs, Donald E. Hagen, Daniel R. White, A. R. Hopkins, Max B. Trueblood

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This second progress report describes the status of the project one and one-half years after the start. The goal of the project is to develop the instrumentation to collect cloud condensation nuclei (CCN) in sufficient amounts to determine their chemical composition, and to survey the CCN composition in different climates through a series of field measurements. Our approach to CCN collection is to first form droplets on the nuclei under simulated cloud humidity conditions, which is the only known method of identifying CCN from the background aerosol. Under cloud chamber conditions, the droplets formed become larger than the surrounding aerosol, …


Analysis Of Algorithms For Velocity Estimation From Discrete Position Versus Time Data, Ronald H. Brown, Susan C. Schneider Phd, Michael G. Mulligan Feb 1992

Analysis Of Algorithms For Velocity Estimation From Discrete Position Versus Time Data, Ronald H. Brown, Susan C. Schneider Phd, Michael G. Mulligan

Electrical and Computer Engineering Faculty Research and Publications

Algorithms for constructing velocity approximations from discrete position versus time data are investigated. The study is limited to algorithms suitable to provide velocity information in discrete-time feedback control systems such as microprocessor-based systems with a discrete position encoder. Velocity estimators based on lines per period, reciprocal-time, Taylor series expansion, backward difference expansions, and least-square curve fits are presented. Based on computer simulations, comparisons of relative accuracies of the different algorithms are made. The least-squares velocity estimators filtered the effect of imperfect measurements best, whereas the Taylor series expansions and backward difference equation estimators respond better to velocity transients.


High Temperature Alloys Synthesis By Electro-Discharge Compaction, Kenji Okazaki Jan 1992

High Temperature Alloys Synthesis By Electro-Discharge Compaction, Kenji Okazaki

Chemical and Materials Engineering Faculty Patents

A method is provided for synthesizing high temperature alloys from elemental powders. The method includes the steps of placing the elemental powders to be processed in a die. A relatively high pressure is then applied to the powders. Substantially simultaneously, an electrical discharge is applied to the powders. The discharge is of relatively high voltage and current density to provide alloying. A product fabricated by the present method is also described and claimed.


Improved Crystalline Quality Of Si1-XGeX Formed By Low-Temperature Germanium Ion Implantation, Ken-Ichi Shoji, Akira Fukami, Takahiro Nagano, Takashi Tokuyama, Cary Y. Yang Jan 1992

Improved Crystalline Quality Of Si1-XGeX Formed By Low-Temperature Germanium Ion Implantation, Ken-Ichi Shoji, Akira Fukami, Takahiro Nagano, Takashi Tokuyama, Cary Y. Yang

Electrical and Computer Engineering

Improvement of crystalline quality in Si1-xGex formed by germanium ion implantation has been found. End‐of‐range defects were drastically reduced in number by lowering the substrate temperature during implantation with doses on the order of 1016 cm−2. This improvement was confirmed by electrical characterization of p‐n junctions formed in the SiGe layer as well as by transmission electron microscopy.


An Investigation On The Skill Requirements Of A Manufacturing Engineer In A Computer Integrated Manufacturing Environment, Wayne E. Frost Jan 1992

An Investigation On The Skill Requirements Of A Manufacturing Engineer In A Computer Integrated Manufacturing Environment, Wayne E. Frost

Graduate Research Papers

The problem for this study centers on these questions:

What skills will a manufacturing company's manufacturing engineers require to : 1) Implement successfully computer integrated manufacturing. 2) How will they obtain these skills?


Computational Investigation Of Slot Blowing For Fuselage Forebody Flow Control, Scott M. Murman, Yehia M. Rizk, Russell M. Cummings, Lewis B. Schiff Jan 1992

Computational Investigation Of Slot Blowing For Fuselage Forebody Flow Control, Scott M. Murman, Yehia M. Rizk, Russell M. Cummings, Lewis B. Schiff

Aerospace Engineering

This paper presents a computational investigation of a tangential slot blowing concept for generating lateral control forces on an aircraft fuselage forebody. The effects of varying both the jet width and jet exit velocity for a fixed location slot are analyzed. This work is aimed at aiding researchers designing future experimental and computational models of tangential slot blowing. The primary influence on the resulting side force of the forebody is seen to be the jet mass flow rate. This influence is insensitive to different combination of slot widths and jet velocities over the range of variables considered. Both an actuator …


Eies 2 : A Distributed Architecture For Supporting Group Work, Computerized Conferencing & Communications Center, James Whitescarver, Robert M. Czech, Sreenivas Reddy, Ajaz R. Rana, Murray Turoff Jan 1992

Eies 2 : A Distributed Architecture For Supporting Group Work, Computerized Conferencing & Communications Center, James Whitescarver, Robert M. Czech, Sreenivas Reddy, Ajaz R. Rana, Murray Turoff

Computerized Conferencing and Communications Center Reports

The Computerized Conferencing Center (CCCC) at New Jersey Institute of Technology (NJIT) has been researching on-line group communications for 17 years by developing and studying tools to advance the "collective intelligence". The Electronic Information Exchange System 2 (EIES2) provides a research, development and operational environment for distributed computer supported cooperative work (CSCW) systems. The EIES 2 distributed Smalltalk processor provides for rapid prototyping and implementation of muti-media CSCW facilities in the network environment. The Smalltalk support of the object model, and meta-language properties make it ideally suited for incremental development CSCW applications. The EIES2 communication environment supports a decentralized network …


Acuta Enews January 1992, Vol. 21, No. 1 Jan 1992

Acuta Enews January 1992, Vol. 21, No. 1

ACUTA Newsletters

In This Issue

Are you ready for the ADA?

Alabama regulators take aim at campus phone services

NATA asks that blocking services be mandatory for LECS

Distance education programs, technology continue to mature

Message From The President

Merging technologies may mean crossfire of competition

Monographs: opportunity to share knowledge

ADA to have far-reaching effect on telecommunications

Party Line

Annenberg announces distance learning grants

Marketplace Update


All Optical Synchronisation With Frequency Division Using A Self Pulsating Laser Diode, Gerald Farrell, P. Phelan, Joe Hegarty Jan 1992

All Optical Synchronisation With Frequency Division Using A Self Pulsating Laser Diode, Gerald Farrell, P. Phelan, Joe Hegarty

Articles

A master optical clock from a mode locked laser is distributed to two slave twin section lasers. One slave laser divides the optical modulation frequency by 2, the other slave laser multiplies the frequency by 2. It is also possible to vary the multiplication4ivision ratio in a slave laser using only DC control of the absorber of the twin section laser.


Architectural Support For Designing Fault-Tolerant Open Distributed Systems, Salim Hariri, Alok Choudhary, Behcet Sarikaya Jan 1992

Architectural Support For Designing Fault-Tolerant Open Distributed Systems, Salim Hariri, Alok Choudhary, Behcet Sarikaya

Electrical Engineering and Computer Science - All Scholarship

A distributed system consists of autonomous computing modules that interact with each other using messages. Designing distributed systems is more difficult than designing centralized systems for several reasons. Physical separation and the use of heterogeneous computers complicate interprocessor communication, management of resources, synchronization of cooperating activities, and maintenance of consistency among multiple copies of information. The main advantages of distributed systems include increased fault-tolerance capabilities through the inherent redundancy of resources, improved performance by concurrently executing a single task on several computing modules, resource sharing, and the ability to adapt to a changing environment (extensibility). Distributed systems cover a wide …


An Intrusive Fluid Mud Surveying System, Allen Teeter, Glynn Banks, Michael Alexander, Andrew Salkield Jan 1992

An Intrusive Fluid Mud Surveying System, Allen Teeter, Glynn Banks, Michael Alexander, Andrew Salkield

United States Army: Publications

A towable sled was developed at the Hydraulics Laboratory of the Waterways Experiment station in conjunction with SIRAD, Inc. to survey navigation channels with "fluff" or fluid mud. Fluid mud layers on the bottom of navigation channels can result in a false bottom record when surveyed with conventional acoustic fathometers. The WES gage was designed to tow along channel bottoms at a specific gravity of about 1.15- 1.20 g/cc and coincide with nautical depth. To monitor this towed density value, a nuclear density gage was installed in the original prototype. Field trials have been completed at the Gulfport, MS, Calcasieu, …


Translation Of 'Kamalakanta: A Collection Of Satirical Essays And Reflections', Monish Ranjan Chatterjee Jan 1992

Translation Of 'Kamalakanta: A Collection Of Satirical Essays And Reflections', Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

This venture was born initially out of the desire to make those works of Bengali literature which have moved me profoundly, and which I consider first-rate by any yardstick, available to friends and fellow enthusiasts who cannot read the original. In attempting to channel literary and philosophical masterpieces into a different medium, I Have experienced firsthand the formidable challenge that a translator must face because not only of the barrier imposed by the languages involved, but perhaps more so because .of his or her own severely inadequate faculty being called upon to match both the genius and the inspiration of …


Towards The Use Of Situational Information In Information Retrieval, Robert N. Oddy, Elizabeth D. Liddy, Ann Bishop, Eileen Martin, Joseph Elewononi, Bhaskaran Balakrishnan Jan 1992

Towards The Use Of Situational Information In Information Retrieval, Robert N. Oddy, Elizabeth D. Liddy, Ann Bishop, Eileen Martin, Joseph Elewononi, Bhaskaran Balakrishnan

School of Information Studies - Faculty Scholarship

This paper is an exploratory study of one approach to incorporating situational information into information retrieval systems, drawing on principles and methods of discourse linguistics. A tenet of discourse linguistics is that texts of a specific type possess a structure above the syntactic level, which follows conventions known to the people using such texts to communicate. In some cases, such as literature describing work done, the structure is closely related to situations, and may therefore be a useful representational vehicle for the present purpose. Abstracts of empirical research papers exhibit a well-defined discourse- level structure, which is revealed by lexical …


Dynamic Fish Growth Modeling For Tailwater Fishery Management, Ming Shiao, Gary Hauser, Gary Chapman, Bruce Yeager, Tom Mcdonough, Jim Ruane Jan 1992

Dynamic Fish Growth Modeling For Tailwater Fishery Management, Ming Shiao, Gary Hauser, Gary Chapman, Bruce Yeager, Tom Mcdonough, Jim Ruane

United States Department of Energy: Publications

Tailwater fisheries below hydroprojects are affected by variable flows and water quality in dam releases. The Tennessee Valley Authority (TVA) identified undesirable flow regimes, low dissolved oxygen (DO) concentrations, and undesirable temperatures as having the greatest biological impact on tailwater, and steps are being taken to mitigate impacts at numerous dams. To help evaluate mitigation efforts, an interdisciplinary team of water quality modelers, fisheries biologists, and environmental engineers developed a one-dimensional dynamic fish growth model. This model was coupled with previously developed dynamic flow and water quality models. The model results were compared to (1) fish growth data in Norris …


Measured Natural Cooling Enhancement Of A Whole House Fan, Florida Solar Energy Center, Danny Parker Jan 1992

Measured Natural Cooling Enhancement Of A Whole House Fan, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An experimental study was carried out in the summer of 1991 to investigate the natural cooling potential of use of a whole house fan in Central Florida's hot and humid climate. The residential building, in Cocoa Beach, FL, is typical of much of the existing housing stock in Florida: a concrete block structure with R-11 ceiling insulation. The building was ventilated with all windows open during the three month summer test period (June-August). Air temperatures and relative humidity inside the home interior along with exterior meteorological conditions (insolation, wind speed, air temperature, relative humidity) were scanned every five seconds with …


University Of Texas At Tyler Catalog, 1992-1994, University Of Texas At Tyler Jan 1992

University Of Texas At Tyler Catalog, 1992-1994, University Of Texas At Tyler

Catalogs

Archives Space instance: https://archivesspace.uttyler.edu/repositories/2/archival_objects/22366


Determining Maintenance Cost Ratios, Donald S. Remer, Josef S. Sherif, Harry R. Buchanan Jan 1992

Determining Maintenance Cost Ratios, Donald S. Remer, Josef S. Sherif, Harry R. Buchanan

All HMC Faculty Publications and Research

Maintenance is a necessary (and usually burdensome) function for practically all natural and man-made elements. Simply defined, maintenance is the effort to keep a device or system working. The amount of funding allocated for maintenance by an organization is necessarily a compromise, possibly viewed as too much by management and too little by the operators/maintainers. The objective of our study was to report on the wide range of costs involved in maintaining equipment. We discuss some methods that different industries use to measure and report their maintenance costs; we summarize the results of a literature search on the range of …


Broad-Crested Weir Application On 15,000-Acre Farm, Stuart W. Styles Jan 1992

Broad-Crested Weir Application On 15,000-Acre Farm, Stuart W. Styles

BioResource and Agricultural Engineering

Growers in California have been subjected to increasing pressure to account for water used on the farm due to limited water supplies and increasing energy costs. Water measurement capability provides for equitable distribution of assigned costs and enables effective water management to be accomplished. Broad-crested weirs are proven water measurement devices, especially when applied to on-farm applications. The broad-crested weirs and published data were developed by the USDA Agricultural Research Service in Phoenix, Arizona. This paper is a discussion of an application of these weirs.


On Capacity Modeling For Production Planning With Alternative Machine Types, Robert C. Leachman, Tali F. Carmon Jan 1992

On Capacity Modeling For Production Planning With Alternative Machine Types, Robert C. Leachman, Tali F. Carmon

Industrial and Manufacturing Engineering

Analyzing the capacity of production facilities in which manufacturing operations may be performed by alternative machine types presents a seemingly complicated task. In typical enterprise-level production planning models, capacity limitations of alternative machine types are approximated in terms of some single artificial capacitated resource. In this paper we propose procedures for generating compact models that accurately characterize capacity limitations of alternative machine types. Assuming that processing times among alternative machine types are identical or proportional across operations they can perform, capacity limitations of the alternative machine types can be precisely expressed using a formulation that is typically not much larger …


Application Of Optical Emission Diagnostics And Control Related To Semiconductor Processing, Richard N. Savage, Greg C. Viloria Jan 1992

Application Of Optical Emission Diagnostics And Control Related To Semiconductor Processing, Richard N. Savage, Greg C. Viloria

Materials Engineering

This paper discusses and shows applications of optical emission spectroscopy techniques and methods to monitor plasma emissions during semiconductor processing. A brief discussion of the instrumentation that was used and the software to control the instrumentation is presented. Optical emission spectroscopy techniques discussed include chemical species identification in plasma etching, process fingerprinting, contamination detection, endpoint analysis/control, and sputter/deposition plasma monitoring.


Hydrodynamics For Water Quality Models, Mark Dortch, Billy Johnson Jan 1992

Hydrodynamics For Water Quality Models, Mark Dortch, Billy Johnson

United States Army: Publications

During the past decade, the US Army Engineer Waterways Experiment station (WES) has developed and applied a variety of numerical water quality models for surface waters. In most cases, the transport terms of these models have been computed using output from numerical hydrodynamic models. This paper summarizes the experience of linking water quality models to hydrodynamic models and examines the need for such linkages.


Physical Modeling Of A High Velocity Covered Urban Drainage Channel, Stephen E. Stump, Charles H. Tate, Robert U. Castle Jan 1992

Physical Modeling Of A High Velocity Covered Urban Drainage Channel, Stephen E. Stump, Charles H. Tate, Robert U. Castle

United States Army: Publications

The design of Oak Street Drain, a 3-mile-long rectangular open channel project in Corona, CA, requires a covered section with a sinuous alignment to avoid commercial development. The alignment includes a reverse 100-ft-radius curve and a long 200-ft-radius curve to convey the 100-year design flow of 7,100 cfs at velocities of 40 fps. A physical model was constructed to verify that the proposed design would pass the design flow without adverse hydraulic conditions.


Hydrodynamic Forces And Evolution Of A Nearshore Berm At South Padre Island, Texas, James A. Aidala, Cheryl E. Burke, T. Neil Mclellan Jan 1992

Hydrodynamic Forces And Evolution Of A Nearshore Berm At South Padre Island, Texas, James A. Aidala, Cheryl E. Burke, T. Neil Mclellan

United States Army: Publications

The evolution of a nearshore feeder berm was correlated to the hydrodynamic forces acting on it for periods of time during which bathymetric and hydrodynamic data sets were available. The evolution of the berm was described in the context of movement and erosion based on wave orbital velocity and bottom current. The berm was constructed and placed offshore at South Padre Island, Texas.


Visualization Of Groundwater Contaminant Parameters, Gregory D. Comes, James Warner, Paul Miller Jan 1992

Visualization Of Groundwater Contaminant Parameters, Gregory D. Comes, James Warner, Paul Miller

United States Army: Publications

Numerical groundwater contaminant modeling is a powerful tool to study the extent of subsurface contamination. Three-dimensional contaminant transport models can predict the future lateral and vertical extent of contamination. Geotechnical and hydrological data is required for the calibration and operation of such models. Understanding the interrelationships of the enormous volumes of data required becomes an onerous task. Visualization of both the input and output data aids the researcher in calibration and comprehension of numerical model results. This paper describes the integration of three-dimensional computer visualization with geotechnical and hydrological parameters for numerical groundwater contaminant modeling. Visualization of subsurface parameters in …


The Application Of Ultrasonic Surface Detectors To Hopper Dredge Production Monitoring, Stephen H. Scott, Angela Freeman Jan 1992

The Application Of Ultrasonic Surface Detectors To Hopper Dredge Production Monitoring, Stephen H. Scott, Angela Freeman

United States Army: Publications

Ultrasonic surface detectors were installed on the us Army Corps of Engineers hopper dredge WHEELER for measuring dredge production. Ultrasonic sensors were installed over the bow and stern of the vessel, port and starboard, to measure vessel draft as a function of dredged material load in the hopper. Four ultrasonic sensors were installed over the hopper to measure the bin water depth in the hopper. This paper describes the ultrasonic sensor operation and installation, and data acquisition and analysis for the test series.


Brief History Of Afmic (Total Manpower), Robert Bolin , Depositor, Jonathan Clemente Jan 1992

Brief History Of Afmic (Total Manpower), Robert Bolin , Depositor, Jonathan Clemente

United States Department of Defense Military Intelligence

Brief History of AFMIC (Total Manpower) from WWI/ (33) to 1992 (82)

U.S. Army Medical Intelligence Office Under SG

DLA Assumes GMI Medical Intelligence Mission

Army SG Continues to Perfonn Medical S&TI

DLA has RIF: Medical Intelligence Division Abolished

Army SG Assumes Entire Medical Intelligence Mission

USAMIIA Fonned (Located at ForrestaJ Buildng)

USAMIIA Move to Fort Detrick (Building 862)

Congress Eliminates All Funding for USAMIlA

DIAlGDIP Program Manager Appeals

Congress Allows Re-establishment of USAMIlA

- Must be Tri-Service

- Must be an Intelligence Activity

Tri-Service AFMIC Established

Anny (DCSINT and SG) Executive Agent

New Building on Fort Detrick

First Non-Army …


Performance Of Chemigation Backflow Prevention Assemblies, H. M. Munir, Dean E. Eisenhauer, John E. Gilley Jan 1992

Performance Of Chemigation Backflow Prevention Assemblies, H. M. Munir, Dean E. Eisenhauer, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

When chemicals are applied using irrigation systems, there is potential for contamination of the water source by backflow if the irrigation system shuts off while unattended. This study was conducted to determine the operating and performance characteristics of new, i.e., unused, chemigation backflow prevention assemblies (CBPAs). Four manufacturer's models were tested in the laboratory. However, two of CBPAs have been modified since the testing was completed. In general, the CBPAs do not meet the standards established for municipal water suppliers and many industries. The backpressures required for the two current models to seal were 0.0 and 6.7 kPa (1.0 psi). …


Biological Discussion Missouri National Recreational River Rehabilitation Gavins Point Dam To Ponca State Park, Nebraska & South Dakota Jan 1992

Biological Discussion Missouri National Recreational River Rehabilitation Gavins Point Dam To Ponca State Park, Nebraska & South Dakota

United States Army Corps of Engineers, Omaha District

The corps of Engineers has received funding for the rehabilitation of the section 32 erosion control projects along the Missouri National Recreational River (MNRR). The project rehabilitation work is as outlined on the attached construction schedule.

Since the Fish & WIldlife's biological opinion on the section 32 program dated March 10, 1980, additional species that may occur in the program area have been listed, including the interior least tern, piping plover, the American burying beetle, and the pallid sturgeon.

The American burying beetle is listed as a federally endangered species in South Dakota. Extant populations are known to occur only …