Engineering Commons^™

Analytic Modeling Of Gain‐Switched Lasers. Ii. Laser Amplifiers, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The pulse transfer characteristics of gain‐switched laser amplifiers are investigated analytically. New closed‐form solutions have been obtained including arbitrary space‐ and time‐dependent pump distributions. The general results are specialzied to the important cases of uniform and traveling‐wave excitation. Input‐pulse shapes considered include step functions, practial oscillator output pulses, and also the inherent spontaneous‐emission noise. The results lead to improved models for pulse amplifiers and mirrorless traveling‐wave lasers. By proper choice of pump characteristics arbitrary output‐pulse waveforms can be synthesized.

Two Preliminary Studies Of The Intelligibility Of Predictor-Coefficient And Formant-Coded Speech, L. Keeler, G. Clement, W. Strong, E. Palmer

Faculty Publications

Two preliminary studies comparing the intelligibilities of predictor-coefficient versus formant-frequency-coded speech and the intelligibilities of predictor-coefficient-coded speech using different numbers of coefficients are reported.

Non-Linear Finite Element Analysis Of Light Gage Steel Shear Diaphragms, Erdal Atrek, Arthur H. Nilson

CCFSS Library (1939 - present)

SUMMARY Shear diaphragm action of properly designed light gage steel panels used for floors, roofs, and walls in steel buildings increase the stiffness and strength of such buildings. Considerable savings in weight and cost can be realized if full account of this action is taken in design. To make good use of the diaphragm action, detailed knowledge on diaphragm response to loading is essential. An efficient computer program has been prepared to analyze light gage steel shear diaphragm behavior in the linear and nonlinear ranges of response, up to collapse. The program uses figinite element concepts for analysis, and has …

The Topolotron: A High Beta Device With Topological Stability, Keith H. Brown, H. R. P. Ferguson, J. H. Gardner, Larry V. Knight, H. Mark Nelson

Faculty Publications

The concept of topological or structural stability is introduced and its importance in the magnetic confinement of plasmas is discussed. Topological stability requires the presence of a pair of limit cycles in the magnetic field configuration. This paper deals with the design of an experimental device possessing limit cycles. The design includes a high beta (b=1), high density (10^16), hot (100 eV) hydrogen plasma which is to be compressed by a factor of about 5 in a torodial device of 25 cm average major radius with a capacitor bank rise time of less than 2 µsec. Two shaped toroidal coils …

Development Of Warrants For Left-Turn Phasing, Kenneth R. Agent

Kentucky Transportation Center Research Report

Warrants for the installation of left-turn phasing were developed. A review of literature was conducted along with a survey of the policies of other states. Field data of delays and conflicts were taken before and after installation of exclusive left-turn signalization. Left-turn delay studies were conducted at intersections with varying volume conditions. Analysis of the effect on accidents of adding a left-turn phase was made. The relationship between left-turn accidents and conflicts was investigated. Other types of analysis concerning gap acceptance, computer simulation, capacity, and benefit-cost ratios were also performed.

It was found that exclusive left-turn phasing significantly reduced left-turn …

Kentucky Research: A Flexible Pavement Design And Management System, Herbert F. Southgate, Robert C. Deen, James H. Havens, William B. Drake

Kentucky Transportation Center Research Report

Various strategies for designing pavement structures are discussed. Initial full-life design, stage designs and planned extensions of service life, final design, surface renewals for deslicking, no-defect designs for high-type high-volume facilities, and allowable-defect designs are considered. Economics enter in terms of salvage value of existing pavements and alternate designs using different proportions of materials within the structure.

The elastic model represented in Chevron's n-layered computer program is the basis for theoretical relationships. Ranges of values are given for input variables such as Young's moduli, Poisson's ratio, thicknesses for layers, tire pressure, and load. The Kentucky CBR is related to modulus …

Cross Florida Barge Canal Restudy Report Summary, Department Of The Army Jacksonville District Corp Of Engineers

Waterways and wildlife

The objective of this study was to prepare a Restudy Report including an environmental assessment and analysis, engineering and cost studies, and updated economic studies on various alter natives for the Cross Florida Barge Canal Project. Detailed engineering, economics and environmental results are presented in separate documents and summarized herein. An environmental impact statement was prepared to accompany the Restudy Report. The basic framework for the studies was regional in scope and included baseline conditions as well as future conditions expected with and without the alternatives studied. Study area delineation was based upon the economic , social, and environmental systems …

Happenings 18 (August 1976 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-)

Communication Processes In The Design And Implementation Of Models, Simulations And Simulation-Games: A Selective Review And Analysis, From The Vantage Point Of Computerized Conferencing, Computerized Conferencing & Communications Center, Julian M. Scher

Computerized Conferencing and Communications Center Reports

Computerized conferencing is a new form of communication which permits a group of individuals, who could be separated in time as well as space, to engage in an interactive dialogue with each other through the convenience of their computer terminals. The software for a computerized conferencing system is designed to keep track of all messages communicated in the system, as well as insure that the various protocols for communication are observed by all.

Our objectives in this report are to examine the communication processes found in the design and implementation of models, simulations and simulation-games, and to identify those areas …

Manufactured Solar Energy Units For Residential Heating, Michael W. Aubrey

Graduate Research Papers

This study is concerned with:

1. researching the principles and technologies of flat-plate solar collector panels, transfer and storage systems that are presently manufactured.

2, compiling an annotated bibliography of local manufacturers and distributors of solar energy units for residential heating.

3. developing a teaching unit on the practical application of these manufactured units to be used in a residential heating systems unit in a high school building construction class.

The Highest And Best Uses Of The Oklawaha River Basin And Lake Rousseau For The Economy And The Environment, Ronald M. North

Waterways and wildlife

The study is designed to assist citizens and officials in a democratic, public decision-making process regarding the best use of a National resource in a conflict situation in which competing objectives and goals are largely exclusive. A barge canal cannot be built without incurring social, economic and environmental benefits and costs. A wild and scenic river cannot be developed without incurring a different set of social, economic and environmental benefits and costs. Is there a balance or a point of convergence which can be reached? The alternatives presented will indicate. some of the significant measures of value for any choice, …

Frequency-Mixing Detection (Fmd) Of Polarization-Modulated Light, R. M.A. Azzam

Electrical Engineering Faculty Publications

When a light beam whose polarization and intensity are weakly modulated at a frequency ω_m passes through a periodic analyzer of frequency ω_a(<ω_m) and the transmitted flux is linearly detected, the resulting total signal S_t consists of two components: (i) a periodic baseband signal S_bb with harmonics of frequencies nω_a (n = 0,1,2,…) and (ii) an amplitude-modulated-carrier signal δS_mc with center (carrier) frequency ω_m and sideband frequencies at ω_m ± nω_a(n = 1,2,…). In this paper we show that the average polarization of the beam is determined …

Interpretation Of Tests On Welded Light Gage Steel Connections, Mark Shephard, George Winter, Teoman Peköz

CCFSS Library (1939 - present)

INTRODUCTION This report interprets the results of three sets of test data (Ref. 1 through 3) on welded light-gage cold-formed steel specimens. The tests were conducted at Cornell for the American Iron and Steel Institute on 252 symmetric puddle and fillet welded connections tested under monotonically increasing static load. The tested connections consisted of 130 shop welded specimens and 122 field welded specimens. All test connections had the same basic configuration being made up of center plates, referred to as parent plates or connected plates in the references, butted together with one or, in the case of the double sheet …

Bolted Connections In Cold-Formed Steel Structures, Randall L. Mosby, Wei-Wen Yu

CCFSS Library (1939 - present)

INTRODUCTION A. Purpose of Investigation. The design of bolted connections in cold-formed steel structures is based on the present AISI Specification for the Design of Cold-Formed Steel Structural Members. 1 Prior to the development of the design criteria, bolted connections were tested at University of Michigan 2 in the 1940's and then at Cornell University 3,4 in the 1950's. The present design provisions were developed primarily on the basis of the tests conducted by George Winter and his associates at Cornell University. Additional tests were recently made by Popowich 5 on multi-bolt connections and by Dhalla 6 on connections with …

Freeze-And-Thaw Of Concretes And Aggregates, James H. Havens, Robert C. Deen

Kentucky Transportation Center Research Report

This report summarizes several years of research relating to damage to concrete and aggregates undergoing freezing and thawing. Basic principles involving freezing and attendant pressures are considered. Application of these principles to the evaluation of concrete was accomplished in experiments on concrete having low and high air contents. The effects of air entrainment upon freeze-thaw resistance were demonstrated.

Freeze-thaw characteristics of saturated aggregates relative to physical properties such as porosity, absorption, and bulk specific gravity were studied by submerging individual particles in pre-chilled mercury. Pressures associated with popouts in concrete were monitored and are presented along with accompanying theoretical considerations.

Effect Of Pavement Texture On Traffic Noise, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

Noise from highway vehicles emanates primarily from engine exhausts, tire-pavement interaction) gears, and rattles. Studies have shown that at high speeds tires become the dominant generators of noise. Measurements on different road surfaces have produced different noise-versus-speed relationships (1). This led to the road surface adjustment used in the noise prediction procedure developed in NCHRP Report 117 (2). This adjustment called for a 5 dBA reduction for smooth surfaces (very smooth, seal-coated asphalt pavement) and a 5 dBA increase for rough surfaces (rough asphalt pavement with voids 1/2 inch (12 mm) or larger in diameter and grooved concrete). …

Highway Accidents At Bridges, Kenneth R. Agent, Robert C. Deen

Kentucky Transportation Center Research Report

Grade-separation structures (bridges) at interchanges, crossroads, over streams, railroads, etc., which are intended to provide greater convenience and safety, otherwise involve features which either obstruct the range of free travel or serve as containment barriers. The objective of this study was to identify those principal features of bridges and appurtenances which may be related to accident frequency and severity and to provide some further insights toward highway safety.

Pedestrian Accidents In Kentucky, Charles V. Zegeer, Robert C. Deen

Kentucky Transportation Center Research Report

When a pedestrian is hit by a motor vehicle, he is usually injured or killed; there is no protective cushion to absorb the impact. The high concentration of pedestrians in urban areas, coupled with heavy vehicle traffic, often results in large numbers of pedestrian accidents. In rural areas, there are considerably fewer pedestrians but traffic speeds are higher and, therefore, accidents are more often fatal.

Pedestrian fatalities have increased in the United States from about 7,800 in 1960 to approximately 10,500 in 1973 (1). There are 120,000 pedestrian accidents each year. Total traffic accidents in the US number about …

Speed Reduction In School Zones, Charles V. Zegeer, James H. Havens, Robert C. Deen

Kentucky Transportation Center Research Report

The use of flashing beacons together with signing has become somewhat standard throughout the country to alert drivers to the presence of school children and to regulate vehicle speed in school zones. Yellow beacons, usually two flashing alternately, may be used with both warning signs and regulatory signs. The only regulatory signs related to school zones are speed-limit signs. Both hazard identification beacons and speed-limit sign beacons are intended to operate only during hours when the warning and speed regulations are in effect. The effectiveness of signs and flashing lights in reducing speeds in school zones has been questioned.

The …

Development Of A Water Quality Simulation Model Applicable To Great Salt Lake, Utah, Craig T. Jones, Calvin G. Clyde, William J. Grenney, J. Paul Riley

Reports

The development of a model capable of predicting the long term (seasonal) . distribution of water quality constituents within Great Salt Lake was undertaken as a portion of the ongoing Great Salt Lake project at Utah State University. The overall goal of the project is the development of a modeling framework to assist relevant decision making bodies in the comprehensive management of the Great Salt Lake system. Phase I of the project provided the overall structural framework for management of the Great Salt Lake system, identified data needs, and established priorities for the development of submodels for incorporation into the …

An Energy Accounting Evaluation Of Several Alternatives For Hydropower And Geothermal Development, J. Clair Batty, J. Paul Riley, William J. Grenney, David A. Bell

Reports

Alternative management strategies for hydropower and geothermal development are myriad. This study does not attempt to evaluate or even summarize the many schemes which are possible. In an era of plentiful natural resources, economic analysis procedures for selecting a particular alternative have been developed which traditionally have tended to optimize on the basis of capital and labor. The approach taken in this study is based on the notion of optimum deployment of finite resources. A legitimate question which this study has attempted to address is: Does the construction of large water management facilities, such as hydropower dams, which involve huge …

The Effects On Agriculture In Utah Of Water Transfers To Oil Shale Development, B. Delworth Gardner, Kenneth S. Lyon, Roger O. Tew

Reports

In Part I the institutional factors affecting water distribution in the Upper Colorado River Basin in general and specifically the Uintah Basin are presented. The historical development of the appropriation doctrine of water allocation is outlined and Utah water policy is examined. These institutional factors are analyzed in light of the prototype oil shale development in the Uintah Basin and potential impact on the area's agricultural sector. Oil shale water estimates are compared with Uintah Basin water availability and examined with regard to population projections and municipal water use. Lastly, Utah water policy and the appropriation doctrine are viewed as …

Modulated Generalized Ellipsometry, R. M.A. Azzam

Electrical Engineering Faculty Publications

We extend ellipsometry to the direct measurement of small perturbations of the Jones matrix of any linear nondepolarizing optical sample (system) subjected to a modulating stimulus such as temperature, stress, or electric or magnetic field. The methodology of this technique, to be called Modulated Generalized Ellipsometry (MGE), is presented. First an ellipsometer with arbitrary polarizing and analyzing optics is assumed, and subsequently the discussion is specialized to a conventional ellipsometer having either the polarizer-sample-analyzer (PSA) or the polarizer-compensator-sample-analyzer (PCSA) arrangement. MGE provides the tool for the systematic study of thermo-optical, piezo-optical, electro-optical, magneto-optical, and other allied effects for both isotropic …

Computerized Conferencing And The Homebound Handicapped, Computerized Conferencing & Communications Center, Murray Turoff, Howard Gage

Computerized Conferencing and Communications Center Reports

Computer conferencing is a relatively new technique which can be applied to improve both the efficiency of education, and communication services available to the homebound handicapped. A system is currently being implemented at the New Jersey Institute of Technology which allows such individuals to engage in a written form of conversation with other individuals or groups. Here the computer stores the discus­sion and keeps track of what everyone has or has not seen, so participants can communicate at a time and pace of their choosing. There is also provision for a range of ancillary facilities such as voting, word processing, …

Test 1211: Case M-B 4/94 Diesel (Unimog), Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT GENERAL CONDITIONS Each tractor is a production model equipped for common usage. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operator station. Additional weight can be added as ballast if the manufacturer regularly supplies it for sale. The static tire loads and the inflation pressures must conform to recommendations in the Tire Standards published by the Society of Automotive Engineers. PREPARATION FOR PERFORMANCE RUNS The engine crankcase is drained and refilled with a measured amount of new oil conforming to specifications in the operator’s manual. The fuel …

Comment On “Two-Magnon Resonant Raman Scattering In Mnf2”, D. L. Rousseau, R. E. Dietz, P. F. Williams, H. J. Guggenheim

P. F. (Paul Frazer) Williams Publications

We have not been able lo reproduce the recently reported resonance enhancement of Raman scattering from magnons in MnF₂ by Amer, Chiang, and Shen. Fifteen crystals ranging from extremely pure samples to ones with high concentrations of impurities, in addition to one supplied by Amer, Chiang, and Shen, were investigated. By observing the off-resonance scattering, we conclude that if an enhancement of greater than a factor of 2 were present, it would have been seen in our resonance spectra.

Mechanical Connections In Cold-Formed Steel: Comprehensive Test Procedures And Evaluation Methods, John Fraczek, George Winter, Teoman Peköz

CCFSS Library (1939 - present)

Design equations do not exist for connections in cold-formed steel formed with most types of mechanical fasteners, and such designs are presently based on test results. A lack of standard test procedures and corresponding evaluation methods impedes the acceptance of connection designs and the exchange of information vital to understanding the connection performance of a large number of mechanical fasteners with diverse properties. Initial steps toward standardization are taken with the development of fixtures and procedures for single shear, pullout and pull-over tests. The proposed single shear tests employ both a simple specimen formed with two overlapping straps and a …

Performance Of Unstiffened Compression Elements, Venkatakrishnan Kalyanaraman

CCFSS Library (1939 - present)

The elastic and inelastic local buckling and elastic postbuckling behavior of unstiffened elements in cold-formed steel members and their effects on bending of beams and overall flexural buckling of columns have been investigated. An analytical investigation of the elastic and inelastic local buckling and the elastic postbuckling behavior of unstiffened elements with an elastic rotational edge restraint has been carried out. Results of experiments on short columns, long columns and beams are presented and compared with the analytical solution. An effective width equation for the elastic postbuckling range of the unstiffened element behavior has been derived by modifying the analytical …

Proposed Criteria For Load And Resistance Factor Design Of Steel Building Structures, Theodore V. Galambos

CCFSS Library (1939 - present)

No abstract provided.

Constant-Rate-Of-Strain And Controlled-Gradient Consolidation Testing, C. Thomas Gorman

Kentucky Transportation Center Research Report

Controlled-gradient (CG), constant-rate-of-strain (CRS), and conventional incremental-loading (STD) consolidation testing are compared and evaluated. Undisturbed samples representing three soils common to Kentucky were used in the testing program. Settlements estimated by each testing technique were compared with settlement records from one of the sites. Results of 15 CG, 14 CRS, and 32 STD consolidation tests are shown. No significant differences were noted in values obtained from the three types of consolidation tests. Feasibility of the new test methods for routine testing is briefly discussed and recommendations were made for refinements in testing procedures.