Engineering Commons^™

Experimental Measurement Of Particle Dispersion In Turbulent Flow, N. M. Howard, C. C. Meek, B. G. Jones

Symposia on Turbulence in Liquids

The dispersion of particles in turbulent flows, phenomena such as dispersion, diffusion, and sedimentation, and a more fundamental point of view, the description of particle interaction with the turbulent field are recently of increasing interest. A system capable of investigating statistical structure of the motion of particles in a turbulent fluid flow using a turbulent water pipe flow system and particles tagged with C0-60 radioactive pellets has been constructed and tested. The particles were followed in their trajectory by a group of detectors consisting of NaI(Tℓ) crystals mounted on photomultiplier tubes which move with the particles on a movable carriage. …

A Comparison And Analysis Of Detection Methods For The Measurement Of Production In A Boundary Layer, G. R. Offen, S. J. Kline

Symposia on Turbulence in Liquids

Two hot films and dye visualizations have been employed, simultaneously, in a turbulent boundary layer to explore the relations among visual observations and five kinds of detection methods using conditional sampling. The results show that all methods correlate positively with each other, but not with high enough values of correlation coefficients to indicate true correspondence between any two thus far studied. Moreover, none of the detection methods devised to date indicate a plateau in number of events as a function of trigger threshold.

The results also provide additional information on several other matters: (i) the relationship of outward motions from …

An Experimental And Theoretical Study Of The Viscous Sublayer For Turbulent Tube Flow, Lindon C. Thomas, H. L. Greene

Symposia on Turbulence in Liquids

Flush-mounted anemometer probes have been used to further study characteristics of the viscous sublayer for both Newtonian and drag reducing solutions, with particular emphasis given to low Reynolds number turbulent tube flow. Experimental measurements for the mean frequency of bursting or renewal within the wall region are compared with theoretical predictions obtained on the basis of the surface renewal and penetration model.

Both theory and experiment taken together suggest that the effect of the mean axial pressure gradient on the viscous sublayer becomes important for the deeper molecular penetration associated with low Reynolds number flow. Also, a pronounced lessening of …

On The Interpretation Of The Output Of Hot-Film Anemometers And A Scheme Of Dynamic Compensation For Water Temperature Variation, J. Tan-Atichat, H. M. Nagib, J. W. Pluister

Symposia on Turbulence in Liquids

Using a special calibration tunnel developed during the course of this study, the static and dynamic response of several kinds of commercially available hot-film probes with single and multiple sensors of the cylindrical-fiber type are examined. The effects of different parameters, including those of the anemometer bridge, on the output and performance of the probes are evaluated. In particular, the consequences of variations in water temperature on the hot-film anemometer output are determined. The results reveal a large effect of the water temperature on the calibration curves (in an extreme case a change in temperature of only 5.5°F can result …

Measurements Of Pulsating Turbulent Water Flow In A Tube, S.-Z. Lu, R. J. Nunge, F. F. Erian, M. Mohajery

Symposia on Turbulence in Liquids

The experimental method associated with obtaining meaningful information from the hot-film anemometer signals in fully developed pulsating turbulent flow where the pulsations are sinusoidal in time is discussed. The results of a number of experiments in water reveal the nature of the longtime and short-time average velocity and pressure. Velocity measurements between 0.95 radii and the centerline demonstrate that the long-time average velocity distribution is coincident with that for steady turbulent flow at the same Reynolds number. Also, no significant differences between the longtime average axial pressure drop in the pulsating and steady flows were noted, although this requires further …

Intermittency And Structure Of A Jet Exhausting Into A Stratified Fluid, Alan Brandt, H. E. Gilreath, C. L. Yates, C. R. Walton

Symposia on Turbulence in Liquids

This preliminary study of the mechanism by which local turbulent regions generate internal gravity waves in a stably stratified fluid is based on comparisons of the visual and hot-film- anemometer observations of a jet exhausting into a stratified fluid with those for a jet exhausting into a homogeneous medium. The stratified environment limits the growth of the mean jet boundary, or from another point of view, inhibits the vertical motion of the instantaneous turbulent/non-turbulent interface. The visual and non-conditional statistical averages agree with expectations and with previous measurements in stratified turbulent wakes. Application of a standard criterion to determine the …

Promising Directions For Liquid Turbulence Research --Panel Discussion, Victor Goldschmidt, J. H. Whitelaw, V. A. Sandborn, Val Kibens, R. E. Kaplan

Symposia on Turbulence in Liquids

No abstract provided.

Bridge / Tunnel Crossing Study : Portland Harbor - Fore River, Portland - South Portland, Maine Department Of Transportation

Maine Collection

Bridge / Tunnel Crossing Study : Portland Harbor - Fore River, Portland - South Portland

Report by Fay, Spofford & Thorndike, Inc., Engineers, Boston, Mass.

Prepared for the Maine Department of Transportation, Augusta, Maine, 1973.

Contents: Table of Contents / List of Figures / List of Tables / Introduction / Summary of Findings / Section 1 - General Background - Location Study / Section 2 - Alternative Facilities and Locations / Section 3 - Comparison of Construction Costs - Tunnel Versus Bridge / Section 4 - Traffic Analysis / Section 5 - Cost Effectiveness Analysis / Section 6 - Financial …

Diaphragm Braced Thin-Walled Open Sections And Design Of Wall Studs, Amir Simaan, Teoman Peköz

CCFSS Library (1939 - present)

INTRODUCTION Cold-formed steel wall studs generally are I, Z or channel shaped with or without stiffening lips, and with webs perpendicular to the plane of the wall. Because of their configuration and dimensions, these sections are quite unstable by themselves. However, the stability and, hence, load-carrying capacity of such studs are increased substantially once they are connected to the wallboard material. The main function of the wallboard is that of enclosure, but it serves also as a bracing system for the studs. Gypsum board, vegetable fiberboard, tempered board or plywood are commonly used wallboard materials. Such boards are connected to …

Dynamic Response Of Forced Convective Heat Transfer From Cylinders To Low Prandtl Number Fluids, D. G. Malcolm, V. Verma

Symposia on Turbulence in Liquids

The present paper can be viewed as an extension of the work of Lim and Sleicher (9). They evaluated the frequency response of the heated element submerged in liquid metal by a perturbation method for Peclet numbers of up to 0.4. Velocity fluctuations were assumed small and second-order perturbations neglected. The Oseen approximation was made to the velocity field. Here the velocity configuration has been approximated to that of potential flow and the convection equation has been solved numerically with the aid of a digital computer. The potential flow approximation, as compared with the Oseen approximation, is reasonable over a …

De Los Sealabs A Los Skylabs, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

¿Respiraremos Algún Día El Agua Del Mar?, Javier Gimeno, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Chronic Toxicity Of A Copper, Cadmium And Zinc Mixture To The Fathead Minnow (Pimephales Promelas Rafinesque), John G. Eaton

United States Environmental Protection Agency: Publications

Fathead minnows were exposed to a series or concentrations of a copper, cadmium and zinc mixture during a 12.5 month chronic test in water of 200 mg 1^-1 total hardness. The metal concentrations in the mixture were selected on the basis of results obtained during previous chronic exposures to each of the metals individually in the same water. Strict summation of the chronic toxicities of the metals was not indicated when they were tested in combination. Toxic effects of the mixture attributable to copper appeared to be increased, but that attributable to cadmium was reduced. The effects thought to …

A Simplified Flow-Splitting Chamber And Siphon For Proportional Diluters, Duane Benoit, Frank A. Puglisi

United States Environmental Protection Agency: Publications

Simplified flow-splitting chambers and siphons were designed and tested for use with proportional diluters in bioassay systems. The apparatus allows each concentration from the diluter to be thoroughly mixed and divided four ways for delivery to duplicate fry and adult exposure tanks. Test water delivered to each exposure tank varied by only 5-10 per cent of the calculated volumes.

Chronology Of Army Medical Intelligence, 1941-1973, Robert Bolin , Depositor, Jonathan Clemente

United States Department of Defense Military Intelligence

This “Chronology of Medical Intelligence” lists the chiefs of the Army medical intelligence effort and the designations of the medical intelligence organization.

Interestingly, the first heads of the effort Captain Tom F. Whayne, MC, USA, and LTC Gaylord W. Anderson, MC, AUS, participated in the preparation of the official history of Medical Intelligence during World War II. SEE: Gaylord Anderson, MD, "Medical Intelligence" IN: Preventive Medicine in World War II. Vol IV, Special Fields, ed. COL Robert S. Anderson, MC, USA and Ebbe Curtis Hoff, PhD, MD (Washington DC, Department of the Army, 1969).

Dr. Arthur Turner, a civilian, was …

A Nuclear Power Plant Simulator, John Jacob Adams

Retrospective Theses and Dissertations

The United States' energy crisis, which has received so much publicity lately, has focused national attention on how we are to meet our energy demands. Proposed energy sources include conventional nuclear power plants, breeder reactor and fusion reactor plants, coal gasification, liquid hydrogen, solar energy, and geothermal energy. All of these except conventional fission plants are still on the drawing board or in the experimental laboratory, and are described briefly. Government and industry are betting heavily on conventional nuclear power plants. ($40 billion already spent by private utilities for 30 operating plants, 60 under construction, and 75 on order.) A …

The State-Space Approach To Network Synthesis, Gary Landis Hasty

Retrospective Theses and Dissertations

No abstract provided.

The Design Of A Digital Data Acquisition System For Jet Engine Testing, Robert Wesley Carter

Retrospective Theses and Dissertations

This research report documents the various types of Data Acquisition Systems in use for testing jet aircraft engines. The cost trade offs and design considerations are explored for systems which employ a digital computer as the prime recording/processing element. The digital computer has revolutionized the data acquisition field, particularly in the testing of high performance jet engines. Test data can be acquired, processed, converted to engineering units, and out via high speed line printers and cathode ray tubes (CRT's). The data acquisition system operates on-line, and interleaves the random requests for data from multiple test cells by using a specially …

Digital Image Processing By The Two-Dimensional Discrete Fourier Transform Method, Lyman F. Joels

Retrospective Theses and Dissertations

No abstract provided.

Accumulative Errors In Low-Level Mos-Fet Multiplexers, Lloyd Daniel Griffin

Retrospective Theses and Dissertations

This paper provides a brief historical discussion of the development of time division low level multiplexing techniques and especially emphasizes MOS-FET multiplexers currently being implemented. Error sources which may affect system accuracy and therefore must be considered in the design of the multiplexer are described. Some of the more significant of these errors: aliasing, interchannel crosstalk, static offset, transient coupled errors, and common-mode injected errors are analyzed and covered in detail. Equations expressing the overall interchannel DC crosstalk and static offset for a generalized multiplexer are derived and presented. Settling errors arising from transient events in time division multiplexers are …

A Study Of The Microwave Reflective Properties Of Aerosols, Paul Edward Speh

Retrospective Theses and Dissertations

This thesis deals with the reflective properties of selected aerosols subjected to microwave radiation. The backscatter cross section of a sphere is developed analytically as a basis for experimental verification. The most pertinent material parameters necessary for maximum reflectivity are discussed and are used to justify the aerosols selected for the experiment. The experimental procedures and the equipment calibration techniques are prefaced by a discussion of the design and the construction of the aerosol chamber and the microwave source apparatus. The experimental results and the calculated backscatter cross section of the aerosols listed are examined. Conclusions are discussed and applications …

The Safety And Environmental Effects Of Nuclear Power Plants, Raymond E. Schweikart

Retrospective Theses and Dissertations

The nuclear power plant has given new direction to power generation. It offers a new source of heat. The heat can now come from the fission of atomic fuel and not from the burning of fossil fuel. Safety and protection from the possible hazards of radioactivity generated by nuclear power plants is a completely new and untested area. Emergency systems and over designed construction are only part of what has to be done to make absolutely certain such accidents, if they occur, will be contained allowing no harmful radioactivity to reach the environment. Handling of radioactive wastes is very critical …

The State-Of-The-Art Of The Coagulation/ Flocculation Process, David William Bouck

Retrospective Theses and Dissertations

This report has been prepared with the idea of briefly summarizing the most important principles underlying the coagulations/flocculation process as it applies to water and wastewater treatment. The production of potable water from a supply which has been contaminated by naturally-occurring or man-made pollutants has been an object of concern throughout history. Several broad aspects have been considered in the report, such as the history, the nature and physical chemistry of colloidal particles, the theories of and the factors affecting coagulation/flocculation, and control of the coagulation/flocculation process. It is advisable for those persons engaged in the dynamic environmental sciences to …

Removal Of Color From Surface Water In Central Florida, Joseph R. Wanielista

Retrospective Theses and Dissertations

The USPHS limits color in water to 15 color units. However, it is desirable to remove all the color. Color in surface water is mainly due to humic substances and was found in concentrations varying up to 450 color units. Removal of color by coagulation and flocculation has been practiced over the years. The mechanisms involved have not yet been fully understood. During the course of this investigation, a literature survey, studying the nature of color, mechanisms or color removal, and optimum color removal conditions, has been conducted. Samples have been obtained from surface waters in Central Florida; namely Big …

A Learning Machine For Job Sequencing In A General-Purpose Computer System, Richard Jon Taylor

Retrospective Theses and Dissertations

No abstract provided.

A Stormwater Overflow Control Device, Richard Duke Stalker

Retrospective Theses and Dissertations

On Lake Eola, stormwater runoff has been identified as a major source of pollution. Other lakes in Central Florida are experiencing similar decay due to stormwater runoff. A device has been examined for diversion of the initial flows to treatment before discharge into the lake. A graphical aid was developed to select the proper volume required for the device and was applied to a Lake Eola existing collection basin. A laboratory model was designed and constructed based on the scaled-down version of a collecting basin on Lake Eola. This model was used to demonstrate the concept, as well as, indicate …

The Effects Of Ionizing Radiation On Gallium Arsenide Phosphide Metal-Insulator-Semiconductor Structures, Gordon James Kuhlmann

Electrical and Computer Engineering ETDs

MIS capacitors were fabricated on n-type GaAs 0.5 p 0.5 using a thermally grown chromium-doped insulator and chromium gate electrode. The fabrication procedures which lead to stable devices are described. The nature of the composite insulator, as well as that of a disordered layer of GaAs 0.5 P 0.5 underneath the insulator are discussed and related to observed electrical characteristics.

Flatband voltages for the capacitors subsequent to device fabrication ranged from -2.5 to -5 volts, corresponding to surface charge densities of 3.1 x 10 11 cm-2 to 4.3 x 10 11 cm-2. Fast interface state densities at flatband varied from …

Investigation Of Sequential Machine Design Techniques For Implementation Of A Trac Scanning Algorithm, Raymond F. Cotton

Retrospective Theses and Dissertations

This report will demonstrate the design techniques to translate a given scanning algorithm into a hardwired pre-processor. The language to be "pre-processed" is TRAC (Text Reckoning and Compiling) devised by Mooers and Deutsch. The major drawback in the current implementation of TRAC is speed. The software overhead required for string manipulations and execution of the input scanning algorithm is the major degrading factor. A TRAC machine consisting of a hardwired pre-processor to scan the input and produce formatted data for a stack oriented evaluator is proposed. The control machine for the input scanning algorithm for the pre-processor is designed using …

Parametric Studies Involving Community Noise Exposure Around Airports, Eldon T. Day

Retrospective Theses and Dissertations

This report uses a computer program to study the effects of the following parameters on noise exposure forecast contours: 1. Aircraft mix, 2. Aircraft track, 3. Number of operations, 4. Time of day and 5. Aircraft thrust.

Triggered Sweep Generators Using Modern Integrated Circuits, Arthur Russell Klinger

Retrospective Theses and Dissertations

The oscilloscope is undoubtedly one of the most important tools in any electronics shop. Presently there are many relatively inexpensive oscilloscopes available, but triggered sweep capability is still reserved for those oscilloscopes costing more than 200 - 500 dollars. The goal of this project was to develop a respectably performing triggered sweep system at a low enough cost to allow inclusion of this valuable feature in any oscilloscope. Two of the most important specifications of an oscilloscope are the bandwidth of the vertical amplifier, and the maximum sweep frequency. The broad class of "inexpensive oscilloscope" would include those with a …