Engineering Commons^™

Acuta Enews August 1992, Vol. 21, No. 8

ACUTA Newsletters

In This Issue

FCC gives nod to touch-tone video

President's column

West Chester starting student resale

Security at Yale

ACUTA Calender

Phone taps snare hackers

Solutions Of The Heat Conduction Equation In Multilayers For Photothermal Deflection Experiments, William A. Mcgahan, Kevin D. Cole

Department of Mechanical and Materials Engineering: Faculty Publications

Exact expressions are presented for the deflection of a laser beam passing parallel to and above the surface of a sample heated by a periodically modulated axisymmetric laser beam. The sample may consist of any number of planar films on a thick substrate. These exact expressions are derived from a local Green’s function treatment of the heat conduction equation, and contain an exact analytical treatment of the absorption of energy in the multilayered system from the heating laser. The method is based on calculation of the normal component of the heat fluxes across the layer boundaries, from which either the …

Modeling Of A-Si : H Deposition In A Dc Glow Discharge Reactor, Dariusz Orlicki, Vladimir Hlavacek, Hendrik J. Viljoen

Papers in Reaction Kinetics

PECVD reactors are increasingly used for the manufacturing of electronic components. This paper presents a reactor model for the deposition of amorphous hydrogenated silicon in a dc glow discharge of Ar-SiH₄ The parallel-plate configuration is used in this study. Electron and positive ion densities have been calculated in a self-consistent way. A macroscopic description that is based on the Boltzmann equation with forwardscattering is used to calculate the ionization rate. The dissociation rate constant of SiH₄ requires knowledge about the electron energy distribution function. Maxwell and Druyvesteyn distributions are compared and the numerical results show that the deposition …

Beginning Of Motion For Selected Unanchored Residue Materials, John E. Gilley, Eugene R. Kottwitz

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Conservation tillage systems help to maintain residue materials from the previous crop on the soil surface. The potential for serious erosion may exist if crop residues are removed by overland flow. This study is conducted to identify the hydraulic conditions required to initiate residue movement by overland flow. Corn, cotton, peanut, pine needles, sorghum, sunflower, and wheat residue are placed in a flume on smooth and sand surfaces, and flow is then introduced in progressive increments. The discharge rate and flow velocity required to initiate residue movement are identified. Hydraulic measurements are used to calculate the ratio of critical flow …

An Optical Technique For Measurement Of Semiconductor Surface Electric Fields, Harshad P. Sardesai, William C. Nunnally

P. F. (Paul Frazer) Williams Publications

We present an optical technique for the measurement of semiconductor surface electric fields. The measurement technique uses the Kerr electro-optic effect in nitrobenzene, a phase sensitive interferometer, and associated data acquisition units to measure the surface electric fields between the contacts of a planar semiconductor device. This technique was used to measure the surface fields on silicon devices used in pulsed power applications, but has the potential for use as an electric field probe for any device having high surface electric fields, both pulsed and dc. The measurement technique showed a temporal resolution of 100 ns, which can be easily …

Acuta Enews July 1992, Vol. 21, No. 7

ACUTA Newsletters

In This Issue

President's column

Two Region Directors elected

Party Line

Northeast Region meeting

In Vitro Development Of Zygotes From Prepubertal Gilts After Microinjection Of Dna, B. L. Williams, J. L. Johnson, A. E.T. Sparks, R. S. Canseco, J. W. Knight, William H. Velander, R. L. Page, W. N. Drohan, J. M. Young, R. E. Pearson, T. D. Wilkins, F. C. Gwazdauskas

Papers in Biotechnology

The effect of pronuclear microinjection of DNA and culture in excised mouse oviducts on the development of porcine zygotes was assessed in this study. Precocious ovulation was induced in prepubertal gilts with pregnant mare's serum gonadotrophin and hCG. Zygotes received either pronuclear microinjection of buffer alone, buffer containing a DNA construct, or no microinjection. Zygotes were cultured in vitro in either modified Krebs-Ringer bicarbonate medium (KRBI for 144 h or in mouse oviduct (MO) explant culture with KRB for 48, 72, 96, or 120 h. Pronuclear microinjection of DNA resulted in a lower (P < .05) cleavage index (CII than did buffer or no microinjection (CI 2.16 k .10 vs 2.80 f .13 and 2.93 f .lo). The CI loss was greatest for DNA-injected zygotes at the two-cell stage of development. Coculture of zygotes in MO resulted in a higher CI (P < .01) than did culture in KRB. Culture in MO for 72 h was the most beneficial system compared with MO for 48, 96, or 120 h (P < .05; CI 3.25 k .12 vs 2.66 k .18, 2.79 f .14, and 2.40 .14, respectively). Microinjection of DNA, not merely the mechanical procedure, was detrimental to early zygote development and may be the cause of low pregnancy rates.

Graded Refractive Index Silicon Oxynitride Thin Film Characterized By Spectroscopic Ellipsometry, Paul G. Snyder, Yi-Ming Xiong, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

A graded refractive index silicon oxynitride (SiO_xN_y) thin film was prepared on a silicon substrate by ion assisted deposition. Spectroscopic ellipsometry (SE) was used to optically analyze the film. The measured SE spectra (2500-8200 Å) were analyzed with several fitting models, whose construction was based on an Auger depth profile of the film. In each model, the optical response of SiO_xN_y was described using the Bruggeman effective medium approximation, by modeling it as a physical mixture of two distinct phases: silicon dioxide and silicon nitride. Grading was modeled by varying the silicon nitride …

Silicon Nitride/Silicon Oxynitrid/Silicon Dioxide Thin Film Multilayer Characterized By Variable Angle Spectroscopic Ellipsometry, Yi-Ming Xiong, Paul G. Snyder, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Variable angle spectroscopic ellipsometry (VASE) was used to nondestructively characterize a silicon nitride (Si₃N₄)/silicon oxynitride (SiO_xN_y)/silicon dioxide (SiO₂) thin film multilayer structure, in which Si₃N₃ and SiO_xN_y layers were deposited by plasma enhanced chemical vapor deposition and low-pressure chemical vapor deposition, respectively. The measured VASE spectra (3500-8200 Å) were analyzed with an appropriate multilayer fitting model, in which the SiO_xN_y layer was modeled. in the Bruggeman effective medium approximation (EMA), to be a physical mixture of two distinct phases, SiO_{2 …}

Acuta Enews June 1992, Vol. 21, No. 6

ACUTA Newsletters

In This Issue

Connectivity, Database Center

President's column

WISE participants

Billed party preference

Keene State gets "slammed"

New Membership Director

Introduction To Intellisim 1.0, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

IntelliSIM is a prototype for a new generation of knowledge-based simulation tool that has been developed by the Systems Simulation Laboratory at Arizona State University. This tool is a computer environment that allows non-simulation trained modelers to predict the performance of a manufacturing system for which the necessary data is available. The system provides predictive data on such items as throughput time, queue levels, equipment utilization, reactions to machine failures, etc. With IntelliSIM, the benefits of discrete-event simulation can be exploited without requiring the high level of expertise necessary to successfully conduct a sound simulation study. The approach offered with …

Acuta Enews May 1992, Vol. 21, No. 5

ACUTA Newsletters

In This Issue

Nominations for officers sought

President's column

AT&T opens development site

Northeast regional meeting

Acuta Enews April 1992, Vol. 21, No. 4

ACUTA Newsletters

In This Issue

Call for Award nominations

President's column

Managing Telecom review

Creighton opens access, ends fraud

Membership Service Coordinator

San Francisco registration form

Temperature Oscillations Of Alternating-Current-Heated Thin Filaments In Ceramic Fiber Production, Hendrik J. Viljoen, Vladimir Hlavacek

Papers in Reaction Kinetics

Resistively heated filaments are used to manufacture ceramic fibers. When an ac power source is used for heating, the temperature of the filament oscillates. These oscillations influence the deposition rate on the surface of the filament. An analysis of this problem is presented, and it is also shown that these oscillatory effects diminish as the filament gauge increases. The analysis can help to decide whether an ac or a dc power source should be used.

Acuta Enews February 1992, Vol. 21, No. 2

ACUTA Newsletters

In This Issue

Call for RD Nominations

President's column

Workshop announcement

Alabama college takes case to PSC

Party Line

Rating to Tucson seminars

Model-Based Target Recognition Using Laser Radar Imagery, Robert Y. Li

Department of Electrical and Computer Engineering: Faculty Publications

Autonomous target recognition can be assisted by using CO2 laser radar data. Of these data, range data provide 3-D geometric information and Doppler data boundaries of moving targets. A powerful 3-D feature extraction algorithm based on the Hough transform is used to obtain the orientations and dimensions of the target. This information is then utilized by an inference procedure that recognizes targets based on the available evidence from the sensory data. The experimental results using actual laser radar imagery are successful and the procedure can be used for the future development of a model-based system for target recognition.

Icosahedral Phase Stabilities In Al-Cu-Ru Alloys, Jeffrey E. Shield, C. Hoppe, R.W. Mccallum, A.I. Goldman, K.F. Kelton, P.C. Gibbons

Nebraska Center for Materials and Nanoscience: Faculty Publications

By examining a wide region of the Al-Cu-Ru phase diagram, a thorough analysis of the compositional and thermal stability of the icosahedral phase has been completed. The primary solidification product of rapid solidification was a topologically and chemically disordered icosahedral phase with an extensive compositional region. Crystallization through exothermic events of the as-solidified materials produced crystalline phases, without the formation of the face-centered-icosahedral (FCI) phase. However, the FCI phase does form at higher temperatures through an endothermic reaction, indicating that it is a stable phase of the system, but only at elevated temperatures. Of the alloys studied, the FCI phase …

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 …

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

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, …

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 …

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

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

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

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

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

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

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

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 …

Three-Dimensional Incompressible Flow Calculations With Maccormack's Method, Robert S. Bernard, Michael L. Schneider

United States Army: Publications

MAC3D is a finite-volume computer code that uses MacCormack's method to calculate three-dimensional incompressible flow on staggered Marker-and-Cell grids. The code accepts nonuniform, nonorthogonal grids for any curvilinear domain that can be mapped onto a single rectangular block. It is applicable for free-surface flow at low Froude number, and for confined flow in general. Computed results from MAC3D are presented for laminar flow in channels with internal obstacles and curved boundaries.