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Adaptive Control Of A Cloud Simulation Chamber Expansion System, Katiya Greigarn

Doctoral Dissertations

"This dissertation describes the design and construction of a closed-loop computer controlled expansion system for a cloud simulation chamber. The chamber is used to simulate atmospheric phenomena for the study of microphysical processes. In order to accomplish this, the sample gas inside the chamber must be expanded adiabatically. This means the wall temperature and the gas temperature must be made to agree as closely as possible. The wall is cooled by thermoelectric modules, and the temperature is controlled by analog controllers. The gas is cooled by the adiabatic expansion, and the corresponding pressure is controlled by a laboratory minicomputer, a …

Measurement Of Poisson's Ratio And Tangent Modulus Of A Loess, Craig Randall Bowers

Masters Theses

"A series of triaxial tests are used to develop mathematical models for tangent modulus and Poisson's ratio for a remolded loessial soil. These two models are then utilized in a finite element computer program to model the behavior of a shallow foundation placed on compacted loess. Different models for Poisson's ratio gave widely varying load settlement curves, however a constant value of .32 gave results very similar to that given by the experimentally developed model. It was found that the model developed for tangent modulus yielded unreasonable results when utilized in the finite element analysis until a limiting value was …

A Study Of A Buoyancy Balanced Gas-Liquid Contacting System, Jaw-Ruey Leu

Chemical and Biological Engineering ETDs

In a conventional gas-liquid contacting system that provides a long gas-liquid contact time, a pressurized gas is released at the bottom of a pool of liquid to form gas bubbles; the bubbles move upward through the liquid and break at the surface of the liquid. A large amount of work is spent in pressurizing the gas. Even though it is theoretically possible to recover work from rising bubbles, a work recovery scheme has not been incorporated into a conventional system.

A buoyancy-balanced gas-liquid contacting system concept has recently been introduced. The system comprises two processing zones filled with a liquid, …

The Effects Of Certain Impurities And Their Interactions On Zinc Electrowinning, Donald R. Fosnacht

Doctoral Dissertations

“The effects of germanium, antimony, arsenic, cobalt, glue, and free acid concentration were studied on both commercial and synthetic electrolytes. The effects of a single factor and the combined effects of multiple factors were elucidated. The temperature, zinc concentration, and current density were also varied. It was found that the acid concentration was the most critical factor when impurity levels were at normal plant solution concentrations. The ranges where the effect of the impurity became apparent were: greater than 20 ppb for antimony; 40 ppb for germanium; 120 ppb for arsenic; and 7-8 mg/l for cobalt for a solution containing …

Conference Tutorials-An Opportunity For Continuing Education, John H. Park, William H. Tranter

Electrical and Computer Engineering Faculty Research & Creative Works

The Educational Services Committee of the IEEE Communications Society has sponsored eleven tutorial short courses at its major conferences over the past six years. The experience gained in developing and presenting these tutorials is shared with others so that they may be in a better position to sponsor similar continuing education activities in the future. The conference tutorial is one example of a continuing education activity that can be sponsored by an IEEE Group or Society as a service to its members. Copyright © 1978 by The Institute of Electrical and Electronics Engineers, Inc.

An Experimental Investigation Of The Hole-Drilling Technique For Measuring Residual Stresses In Welded Fabricated Steel Tubes, Chau Mong Tran

Dissertations and Theses

Among semi-destructive methods of measuring residual stresses in elastic materials, the blind hole-drilling strain-gage method is one of the best because it is simple, economical and accurate. It is based on the measurement of strains disturbed by machining a small diameter shallow hole in the test piece. The strains measured in three known directions permit the determination of the direction and magnitude of principal stresses and subsequently of any stress in any direction.

This thesis presents the investigation of residual stresses in the longitudinal direction of a welded fabricated steel tube of 22 inch diameter, relating to a series of …

An Investigation Into The Elasticity Of Demand For Motor Gasoline, Samy Fouad El-Iskandarany

Dissertations and Theses

This thesis investigates the existence and determinants of the elasticity of demand for motor gasoline.

The research can be divided into four main stages. In the first stage, time series data of fifteen member countries of the Organization for Economic Cooperation and Development (OECD) are analyzed.

The ratio of gasoline price per gallon to the per capita GNP is introduced in this research to explain the variability in the size of the price elasticities of demand over the various countries. The ratio is called the "Price Factor" and designated as P.F. The introduction of P.F. established the basis for meaningful …

A Microprocessor Based-Instrument For Reconstructing A Coherent Optical Wavefront, Glenn Thomas Lommasson

Electrical and Computer Engineering ETDs

Characterizing a propagating laser's wavefront is a necessary procedure when evaluating the performance of coherent lasing systems. Measurement of this wavefront structure uncovers more useful information on the operation of lasing systems than does any other single diagnostic measurement, and is, therefore, critical when analyzing developmental lasers. There are currently several methods being used to measure this wavefront structure. One method that is noted for its operational simplicity measures the gradient of the wavefront as the wavefront is two-dimensionally scanned. An instrument that incorporates this methodology for scanning a wavefront's gradient field has been previously developed. Reconstructing the wavefront using …

Development And Field Testing Of An Electronic Information Exchange System : Final Report On The Eies Development Project, Computerized Conferencing & Communications Center, Murray Turoff, Starr Roxanne Hiltz

Computerized Conferencing and Communications Center Reports

The Electronic Information Exchange System (EIES) is a particular design of a computerized conferencing system intended to allow both the facilitation of scientific and technical communications and experimentation and research into human information-communication processes. To meet the first objective EIES offers functional components of messaging, conferencing, notebooks and bulletins for its users. To meet the second objective EIES allows for the tailoring of interfaces by individuals and groups, and the incorporation of special processing and interconnect options to other computer and information systems.

EIES is designed as a research tool or laboratory without walls in order to allow information scientists …

Official Phone Directory, Us Army Foreign Science And Technology Center, Robert Bolin , Depositor

United States Department of Defense Military Intelligence

This directory contains instructions for using various telephone systems and calling long distance, a thorough organizational listing, a quick reference guide, an alphabetic list of employees, and a world time conversion chart. The organizational listing gives the lists each division and the branches within it and the heads of the divisions and branches with their phone numbers. The list of employees includes the person’s name, his or her office extension and home phone number, office symbol, and room number. If the person listed was not located in Charlottesville, the alphabetic list tells where they were.

Flexible Pavement Designs To Support Various Vehicle Configurations, Robert C. Deen, Herbert F. Southgate

Kentucky Transportation Center Research Report

Pavement designers are often asked if pavements can be designed to carry and support the unusually heavy loads which have been known to use portions of the highway system. In some instances, for example, haul roads leading to highway or other construction projects or haul roads associated with mining, heavy loads have become commonplace and extra-legal. Within limitations of engineering experience, there appears to be no reason why pavements cannot be designed for these heavy loads. Of course, the restrictive factor in implementing such designs may be the excessive costs of construction. Even so, excessive maintenance costs otherwise associated with …

Light Extinction In Polydisperse Particulate Systems, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Analytic methods are developed for determining the attenuation characteristics of light beams propagating through ensembles of scattering particles including those with complex index of refraction. The methods are applicable to a wide range of practical particulate systems, and the results are expressed explicitly in terms of elementary functions. Propagation through fog and clouds is considered as an example, and it is found that absorption by the liquid lengths. water in such ensembles affects strongly the extinction for ir wave-lengths

Cpacs Happenings (December 1977-January 1978 Newsletter), College Of Public Affairs And Community Service, University Of Nebraska At Omaha

CPACS Newsletters

The College of Public Affairs and Community Service (CPACS) newsletter that reported on the news, collaborations, events, and general happenings of the UNO College of Public Affairs and Community Service. This newsletter has had many names and variations over the years including SPACS Newsletter (1973); Newsletter of the College of Public Affairs and Community Service (1973-1974): Happenings (1974-1980s); and the current e-newsletter titled the CPACS Collective (2021-)

An Application Of Infrared Spectroscopy To The Study Of Binder Migration In Paper Coatings, Fred E. Huang

Masters Theses

Multiple internal reflectance (MIR) was used to study binder migration of paper coatings. Casein and an acrylic latex were selected as binders because of their characteristic infrared absorption bands. The coatings analyzed were prepared on the Western Michigan University Pilot Coater using the airknife coating method at different coating speeds. A surface grinder was used to obtain several layers of coating for surface studies.

It was concluded that the MIR technique could satisfactorily be used in the binder migration studies. Its success mainly depends on the precision of surface grinding, caliper measurement and infrared characteristics of the binders. The results …

Computer Graphics: Conversion Of Contour Line Definitions Into Polygonal Element Mosaics, Thomas W. Sederberg

Theses and Dissertations

There has been a disparity between the conventional method of describing topographic surfaces (i.e. contour line definition) and a format of surface description often used in continuous-line computer graphics (i.e. panel definition). The two differ enough that conversion from contours to panels is not a trivial problem. A computer program that performs such a conversion would greatly facilitate continuous tone display of topographical surfaces, or any other surface which is defined by contour lines.

This problem has been addressed by Keppel and alluded to by Fuchs. Keppel's is a highly systematic approach in which he uses graph theory to find …

Report Of Laboratory Tests And Analytical Sudies Of Structural Characteristics Of Cold-Formed Steel-Joist Floor Systems, J. F. Wiss, P. W. Linehan, R. J. Kudder

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Evaluation Of Organic Additives For Use In Zinc Electrowinning, R. C. Kerby, H. E. Jackson, Thomas J. O'Keefe, Yar Ming Wang

Materials Science and Engineering Faculty Research & Creative Works

Organic additives are used extensively in zinc electrowinning to assist in controlling the process. A cyclic voltammetry technique has been developed to provide a rapid, quantitative evaluation of the effectiveness of selected organic additives in minimizing the deleterious effects that impurities, such as antimony, have on zinc deposition. Results have indicated that animal glues are more effective than the other organic additives tested, which included several gums, enzymes, and amino acids, in relation to the current efficiency of zinc production. Of the various animal glues compared in this research, the most effective appeared to have average molecular weights in the …

Assessment Of Feasibility Of Proposed Bolted Connections For Tubular Structures, John Henry Tausch

Dissertations and Theses

The search for new and additional sources of energy -- from sun, wind, waves, and ocean currents -- is necessitating the development of structures in the open environment of the oceans as well as on land. The advantages of round or tubular members for use in such structures are shown; and to avoid the uncertainties of welded joints, two bolted connections are proposed and their feasibility explored.

The Maine Airport System Plan : Summary Report, Systems Analysis & Research Corp.

Maine Collection

The Maine Airport System Plan : Summary Report

Prepared for Bureau of Planning , Maine Department of Transportation by Systems Analysis & Research Corporation and Howard Needles Tammen & Bergendoff, November 1977.

Contents: Foreword / Overview / Background / Aviation in Maine / Preparation of the Plan / The Plan / Implementation of the Plan / Appendix A - Airport Needs by County / Appendix B - Airport Classifications / Appendix C - Maine's Airports by Map Code Identifier / Appendix D - Technical Supplement Table of Contents / Appendix E - Regional Planning Commissions / Appendix F - Advisory …

Traffic Conflicts As A Diagnostic Tool In Highway Safety, Charles V. Zegeer, Robert C. Deen

Kentucky Transportation Center Research Report

Because of the shortcomings in accident data, such as incomplete reporting and inaccurate information on accident reports, a need was found for indicators of accident potential. Nearly half of the 209 locations identified in Kentucky as hazardous by accident criteria were found to be falsely identified due to random accident occurrences. Accident repeatability from one year to the next was found to be poor at 60 intersections (r = 0.64) and 170 spot locations (r = 0.59). Up to two years of accident data were found to be necessary to obtain a reliable base of accident data.

Conflict counts were …

Analysis Of Tandem Axleloads By Elastic Theory, Herbert F. Southgate, Robert C. Deen, James H. Havens

Kentucky Transportation Center Research Report

AASHO Road Test tandem axleloads were analyzed to determine the magnitude of the tandem axleload that causes the same damage as the 18-kip (80-kN) single axleload. The procedure is outlined and is the same used to analyze single axleloads. The essential findings were as follows:

1. One repetition of a 34-kip ( 151-kN) tandem axleload appears to cause the same damage as one repetition of an 18-kip (80-kN) single axleload. 2. The relationships of log repetitions versus axleload used by Kentucky appear to be equally valid for single and tandem axleloads. 3. The use of superposition principles, and equivalency of …

Traffic Conflicts, Erratic Maneuvers, And Near-Miss Accidents: State-Of-The-Art, Charles V. Zegeer

Kentucky Transportation Center Research Report

Definitions are given for the various types of traffic conflicts, erratic maneuvers, and near-miss accidents. The General Motors technique for observation of traffic conflicts is summarized. Procedures used by several highway agencies for collecting conflict data are also detailed. Criteria which have been used to identify hazardous intersections using traffic conflict data are summarized. Methods and examples of evaluating safety improvements are detailed. Relationships between conflicts and accidents found by others were given.

The procedure for observing traffic conflicts on freeway ramps is described. Definitions are given for erratic maneuvers at lane drops, gore areas, and intersections. Results from studies …

Kentucky’S Pavement Management System, James H. Havens, Eugene B. Drake

Kentucky Transportation Center Research Report

Pavement management concepts are discussed, and a method is presented illustrating the required data and its use to accumulate EAL's annually for comparison with the design EAL. This method can be used to determine overlay priorities, overlay design thicknesses, and financing schedules. A discussion of automatic feedback of field data is presented. Pavement condition reports should be analyzed separately to prevent improper adjustments in the design system due to causes of failure other than normal fatigue.

An overlay, whether for extending service life or improving skid resistance, provides an additional structural thickness and will modify the design life.

Preparation of …

Reliability And Surface Degradation Aspects Of Synthetic Insulator Materials For Hv Application, Satyapal S. Bhatia

Dissertations

This study is a theoretical and experimental investigation on the state of the art of synthetic insulators for outdoor high voltage transmission systems.

The surface of a polymeric material is known to be degraded by, among other things, environmental stresses such as UV, air pollutants, etc. The reliability of an insulator material is governed by the surface and other characteristics that do not drift much as a function of stresses and time.

The surface characteristics of various synthetic materials, when these materials were exposed to UV radiation in the laboratory were studied. The changes in the surface properties of these …

So2-Scrubber Technology : Double Alkali Mode, Krishna K. Rao

Theses

Double alkali (D/A) processes for the desulfurization of flue gases occupy an increasingly important role in applied technology.

D/A processes involve two steps, namely, scrubbing and regeneration. In the scrubbing step, the alkali (Na₂SO₃) reacts with SO₂. In the regeneration step the acid formed, NaHSO₃, reacts with an alkali to regenerate Na₂SO₃.

This study was focused on the regeneration step. Regenerants investigated were slurries of lime and limestone. The major factors studied were reactor configuration and mixing patterns.

These systems were investigated in a batch, backmix, and plug-flow …

Municipal Point Source Pollution In The Hackensack Meadowlands Estuary, Alfonso Augustine Hernandez

Theses

A study was performed to evaluate the effectiveness of various sewage treatment facilities in the Hackensack Meadowlands District. The study dealt with overall plant efficiencies based on percent removals of suspended solids and Biochemical Oxygen Demand although other parameters were also included.

Samples for this study were obtained from the inlet and outlet channels of the individual plants. The parameters studied were: Suspended Solids, Biochemical Oxygen Demand, Total Nitrogen, Nitrate-Nitrite Compounds, Total Organic Carbon, Orthophosphate-P, Total Oxygen Demand and Fecal Coliform. Results obtained were averaged so as to collectively represent wet and dry weather conditions.

The results indicate that most …

Dense Chromium Sesquioxide, P. D. Ownby

Materials Science and Engineering Faculty Research & Creative Works

A sintered, fine grained, polycrystalline, essentially fully dense, essentially single phase Cr₂O₃ body is prepared by sintering Chromium Sesquioxide (Cr₂O₃) at essentially the equilibrium oxygen partial pressure (P_O2) for the formation of CrO ₃ from its elements at the sintering temperature. To achieve optimum theoretical density a second metal oxide dopant such as MgO, capable of controlling the grain size, is added. In addition, Cr₂O₃ bodies are rendered more stable, and thus have a longer life, by maintaining over the body an atmosphere which is essentially equilibrium Po, …

Introductory Remarks, Dudley Thompson

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

No abstract provided.

Energy Conservation And U.S. Farm Production Patterns, Angelos Pagoulatos

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

Energy conservation practices in crop production would not substantially reduce energy use. Substantial reductions of energy would imply major structural changes in terms of extensive systems of crop production. The tradeoffs between land and energy for future desired crop outputs are derived.

Stability Of Premixed H₂/O₂/N₂ Combusting Turbulent Jets, H. F. Nelson

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

Experimental measurements and theoretical predictions of the stability of hydrogen-air-nitrogen premixed turbulent flames have been carried out. The turbulent flame is theoretically modeled using finite rate chemical kinetics and a well-stirred reactor. The model contains a free parameter, which is evaluated by comparing the theoretical predictions to experimental results. A hydrogen flame stability experiment was carried out and the results were compared to the theory. The theory and experiment were found to agree, if the free parameter in the theory varied as the reciprocal of the turbulent jet radius squared.