Engineering Commons^™

Acuta Enews July 1984, Vol. 13, No. 7

ACUTA Newsletters

In This Issue

President's Message

Party Line

Time-Compression Multiplexing Squeezing Digits Through Loops

Bits & Pieces

Repair Records lmportant

Wanted, Telecomm Pros

Bulletin - July, 1984, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

A four page newsletter of the Civil Aviation Medical Association. The newsletter provided news about civil aviation medicine and information related to the organization.

Evaluation Of Full-Depth Asphaltic Concrete Pavements, Herbert F. Southgate, Gary W. Sharpe, Mark Anderson, Robert C. Deen

Kentucky Transportation Center Research Report

This study was initiated to verify a newly-developed set of design curves for full-depth asphaltic concrete pavements. Quality control during construction was checked using nuclear density testers, Benkelman beams, and a Road Rater. During the course of this study, an analysis system was developed to interpret the dynamic deflections as measured by the Road Rater and was confirmed by elastic theory. The thickness design curves were verified within the accuracy of construction variations.

Rut depths measured in 1979 were analyzed in terms of potential rut depth resulting from consolidation under traffic due to lack of obtaining 100-percent of Marshall density …

X-Ray Diffraction Studies Of Amorphous Silicon, Adel Gabra I Gouda

Archived Theses and Dissertations

No abstract provided.

Inverting The Ratio Of The Complex Parallel And Perpendicular Reflection Coefficients Of An Absorbing Substrate Using A Transparent Thin-Film Coating, R. M.A. Azzam

Electrical Engineering Faculty Publications

An absorbing substrate can be coated with a transparent thin film of refractive index N₁ (within a certain range) and thickness d such that the ratio of complex reflection coefficients for the p_and s polarizations of the film-covered substrate ρ = R_p/R_s is the inverse of that of the film-free substrate ρ¯ = R¯_p/R¯_s at an angle of incidence ø. A method to determine the relationship among ø, N₁, and d that inverts ρ (i.e., makes ρ = 1/ρ¯) for a given substrate at a given wavelength is described and is …

Inverting The Ratio Of The Complex Parallel And Perpendicular Reflection Coefficients Of An Absorbing Substrate Using A Transparent Thin-Film Coating, Rasheed M.A. Azzam

Electrical Engineering Faculty Publications

An absorbing substrate can be coated with a transparent thin film of refractive index N₁ (within a certain range) and thickness d such that the ratio of complex reflection coefficients for the p_and s polarizations of the film-covered substrate ρ = R_p/R_s is the inverse of that of the film-free substrate ρ¯ = R¯_p/R¯_s at an angle of incidence ø. A method to determine the relationship among ø, N₁, and d that inverts ρ (i.e., makes ρ = 1/ρ¯) for a given substrate at a given wavelength is described and is …

Block Encoding Of Speech Spectral Principal Components, James R. Holland Jr.

Electrical & Computer Engineering Theses & Dissertations

A Karhunen-Loeve series expansion was used to block encode speech spectral principal components as a function of time. Each of ten principal components was first obtained as a linear combination of 2© speech spectral band energies. Using a fixed block length of 10 frames (0.128 s), the K-L basis vectors were computed separately for various speakers for each principal component. In all cases the resulting basis vectors were essentially a set of discrete cosine basis vectors. Synthesis of speech from the block encoded parameters showed that very little information is lost with up to 70% data reduction. The block encoding …

Suboptimal Algorithms For Improvement Of Pipeline Through Insertion Of Delays, Sukhamoy Som

Electrical & Computer Engineering Theses & Dissertations

Pipelining is now widely used in the design of high speed processors in order to overcome the intrinsic speed limitations imposed by the technology. For a good performance and avoidance of internal conflicts, the concurrent operations within different subunits of a pipeline architecture should be properly scheduled This scheduling problem is known to be intrinsically difficult" and a member of the "NP complete class of problems. The aim of this thesis is to develop heuristic suboptimal algorithms whose execution time is a polynomial function of the number of items to be scheduled. Insertion of delay is used as a basic …

A 250-Kv Two-Pulse Modulator For The Gas Flow Switch Test Facility, David Michael Barrett

Electrical & Computer Engineering Theses & Dissertations

High-pressure spark gap switches are often used in pulsed power systems because of their high power capabilities. Unfortunately, these switches cannot be operated at high repetition rates because of the time required for the switch to recover. However, the recovery rate of a spark gap may be improved by flowing a gas through the interelectrode region so as to remove the hot gases and debris.

A test facility has been designed and constructed at Old Dominion University to evaluate the performance of gas-flow spark gap switches operating over a wide range of voltages and flow parameters. The facility consists of …

Studies On The Interference Of Wings And Propeller Slipstreams, Ramadas K. Prabhu

Mechanical & Aerospace Engineering Theses & Dissertations

The small disturbance potential flow theory is applied to determine the lift of an airfoil in a nonuniform parallel stream. The given stream is replaced by an equivalent stream with a certain number of velocity discontinuities, and the influence of these discontinuities is obtained by the method of images. Next, this method is extended to the problem of an airfoil in a nonuniform stream of smooth velocity profile. This model allows perturbation velocity potential in a rotational undisturbed stream. A comparison of these results with numerical solutions of Euler equations indicates that, although approximate, the present method provides useful information …

An Experimental And Analytical Investigation Of Friction Factors For Fully Developed Flow In Internally Finned Triangular Ducts, Hoshang Chegini

Mechanical & Aerospace Engineering Theses & Dissertations

Friction factors for fully-developed flow in triangular ducts with fins of various sizes are investigated for Reynolds numbers ranging from 150 to 90,000. Two triangular ducts having apex angles of 60 and 38.8 degrees are studied. Results are presented in the form of standard plots of friction factor as a function of Reynolds number. Friction factor values for the smooth triangular-duct cases are in good agreement with the existing results. For the finned-duct cases, the fully developed axial-velocity profiles in laminar flow are determined by solving the x-momentum equation iteratively by the Gauss-Seidel finite difference technique. The theoretically determined friction …

Combined Forced And Free Convection In The Trombe Wall Channel, Jim Ginchaun Huang

Mechanical & Aerospace Engineering Theses & Dissertations

A vertical channel connected by horizontal exit and entrance segments is simulated and represents a flow passage for a Trombe wall solar collector. The two-dimensional combined forced and free convection mode is investigated for the laminar regime. The vertical walls of the channel are maintained at a constant but different temperature while horizontal walls are insulated. A finite difference method using up-wind differencing for the non-linear convective terms and central differencing for the second order derivatives is employed to solve the governing differential equations for mass, momentum, and energy balances. The solution is obtained for stream function, vorticity, and temperature …

An Experimental And Analytical Investigation Of The Iosipescu Shear Test For Composite Materials, Barry Stuart Spigel

Mechanical & Aerospace Engineering Theses & Dissertations

Mechanical properties of composite materials under shear loading are difficult to determine. The Iosipescu Shear test, originally proposed for metals, has in recent years been applied to composites. It has the advantages of small specimen size, simple loading and a reasonably uniform shear stress in the test section.

The purpose of this work is to study the validity of the Iosipescu test method for measuring the shear modulus and shear strength of composites. Finite element analyses indicate that optimum specimen geometry and load locations depend upon the degree of orthotropy of the composite. Test results for a quasi-isotropic graphite/epoxy laminate …

Implementation Of Uniform Perturbation Method For Potential Flow Past Axisymmetric And Two-Dimensional Bodies, Tin Chee Wong

Mechanical & Aerospace Engineering Theses & Dissertations

The aerodynamic characteristics of potential flow past an axisymmetric slender body and a thin airfoil are calculated by using a uniform perturbation analysis method. The method is based on the superposition of potentials of point singularities distributed inside the body. The strength distribution satisfies a linear integral equation by enforcing the flow tangency condition on the surface of the body. The complete uniform asymptotic expansion of its solution is obtained with respect to the slenderness ratio by modifying and adapting an existing technique. Results calculated by the perturbation analysis method are compared with the existing surface-singularity-panel method and some available …

Selection Of Sludge Conditioning Chemicals And Filter Media For Vacuum Filter Dewatering Of Sludge At The Atlantic Wastewater Treatment Plant, Douglas W. Fredericks

Civil & Environmental Engineering Theses & Dissertations

A literature review was conducted to determine the types of vacuum filter systems available for sludge dewatering, the characteristics of wastewater sludge which are important to dewatering, and the methods of sludge conditioning for vacuum filtration which are available. Capillary suction time and Buchner funnel tests were performed to determine the dewatering characteristics of sludge conditioned with ferric chloride and lime, polymer, polymer and lime, and polymer and incinerator ash. Filter leaf tests were performed to determine filter cake release characteristics of various conditioned sludge and the performance characteristics of several filter media. It was determined that ferric chloride and …

Irish H & V News

Building Services Engineering

No abstract provided.

Power Characteristics Of Single‐Mode Semiconductor Lasers, Jaroslava Z. Wilcox, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The basic aspects of power calculations for high‐gain semiconductor lasers are briefly reviewed, and a straightforward one‐dimensional model is described. The relative importance of spontaneous emission, distributed losses, band‐to‐band absorption, and high single‐pass gain are investigated in detail.

Wetlands Preservation And The Protection Of Endangered Species As Limits On Western Water Development, A. Dan Tarlock

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

25 pages.

[Section] 404 Panel Discussion, Gregory J. Hobbs, Jr.

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

5 pages.

Supplemental materials. Includes proposed bill language for Department of the Interior appropriations bill. Outline of key events and dates in the history of water law.

Panel: Section 404 Of The Clean Water Act And Section 7 Of The Endangered Species Act: Potential Impacts On Water Supplies [Supplemental Materials], Wendy C. Weiss

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

57 pages.

Supplemental materials. Includes text of Riverside Irrigation District v. Andrews, 568 F.Supp 563 and Opening Brief of Plaintiff-Intervenor-Appellants in Riverside Irrigation District v. Andrews, Cases No. 83-2114, 83-2115, 83-2119, 83-2230, April 3, 1984.

Groundwater Control Programs Affecting Water Development, Arthur L. Littleworth

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

19 pages.

Ferc, Purpa And The Federal Power Act, Lawrence J. Wolfe

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

62 pages.

Contains references.

The Case For A Legislative Solution To Indian Water Claims, James M. Bush

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

57 pages.

Reserved Water Rights Of Indian Allotments, Richard B. Collins

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

10 pages.

Contains references.

Instream Flows As Reserved Rights On Federal Reservations After United States V. New Mexico, Hank Meshorer

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

10 pages.

Effects Of The Clean Water Act On Water Availability And Development, Paula C. Phillips

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

12 pages.

Test 1528: Case 3294 Powershift Diesel 12-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Introduction To Reserved Water Rights, Ralph W. Johnson

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

16 pages.

Indian Water Rights In The Supreme Court: A Review And Preview, Louis F. Claiborne

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

12 pages.

Agenda: The Federal Impact On State Water Rights, University Of Colorado Boulder. Natural Resources Law Center

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

Conference organizers and/or speakers included University of Colorado School of Law professors James N. Corbridge, Jr., David H. Getches, Lawrence J. MacDonnell and Richard B. Collins.

In general, water rights are a matter of state law. However, the availability and development of water are affected by important federal rights, policies and programs. In this conference, an outstanding group of private practitioners, government representatives and academics consider this important topic.