Engineering Commons^™

Experimental Investigation Of The Effect Of Geological Discontinuity Conditions Of Rock Splitting By Blasting, Shijie Qu

Masters Theses

"A series of modal scale, two borehole splitting test blasts was geometrically designed both with concrete and with Plexiglas. The discontinuities were all symetrically located midway between split holes and were oriented perpendicular to the desired split plane. Sand and clay filled discontinuities of 1/16, 1/8 and 1/4 inch width, and closed discontinuities were used. Both discontinuity frequency and width generally reduced the maximum successful split-hole spacing. The regularity and integrity of the split profile became poorer as the discontinuities were closer to the boreholes and the discontinuity width became greater, due to the cratering effect which occurred from the …

An Experimental Investigation Of Electrochemical Memory Cells, Timothy Jules Martin

Masters Theses

"An experimental electrochemical memory cell was constructed using a Pt cathode, Cu anode, and CuS0₄ electrolyte. The mechanism of operation of this cell consisted of plating and stripping of Cu from the Pt cathode. A cathode surface area of l.33 X 10^-4 cm² required approximately 700 μs to store 5 monolayers of Cu, writing time. The access time would be the time required to measure the Pt/Cu potential and was undetermined. Fifteen seconds were projected to oxidize the plated copper, producing loss of information, resulting in poor volatility characteristics of the cell. However, this electrochemical memory cell …

Reaction During Sintering Of Barium Titanate With Lithium Fluoride, Jyoti P. Guha, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The reactions occurring during sintering of stoichiometric BaTiO₃ with small additions of LiF were studied at temperatures between 700° and 900°C. BaTiO₃ reacts with LiF to form a cubic solid solution and Li₂TiO₃ During sintering, the cubic solid solution coexists with Li₂Ti0₃ and forms a liquid phase at 740°± 5°C. The occurrence of a liquid phase at this temperature results in an enhancement of the sintering process and leads to the development of a highly dense microstructure. Copyright © 1986, Wiley Blackwell. All rights reserved

Glass Experiments In Space, Norbert J. Kreidl

Materials Science and Engineering Faculty Research & Creative Works

Current and potential glass research under microgravity includes studies of minimum cooling rate, homogeneous nucleation, diffusion, surface tension and enrichment, fining without buoyancy, avoidance of liquid phase separation, gel synthesis, composites and uniform micro balloons. The experiments do not just anticipate space fabrication but will also provide information and innovation encouraging advanced processing on earth. © 1986.

Closed-Loop Dynamic Response Of A Static Scherbius Drive., Aaron J. Miles, B. Lequesne

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Generalized root-loci techniques, for squirrel-cage motors have been extended to wound-rotor, slip-energy-recovery systems (static Scherbius drive). The influence of a feedback control loop on these root loci is considered. General conclusions on Scherbius drive dynamics, as well as supporting experimental results, are presented.

An Interactive Power System Analyzer With Graphics Display For Educational Use, C. H. Lo, Max Darwin Anderson, Earl F. Richards

Electrical and Computer Engineering Faculty Research & Creative Works

The paper presents a student-oriented power-system analyzer with an interactive graphics display. Its capabilities include studies of (1) load flow, (2) load and generation, (3) voltage level control, (4) economic dispatch, and (5) contingency and planning analysis. Power network configurations of up to 30 buses can be presented clearly on one screen. The interactive nature of this program makes such studies effective and easy to use. With the support of a computer with graphics software and many graphics terminals, this program can be a useful teaching tool for power system studies. Copyright © 1986 by The Institute of Electrical and …

Electrodeposition And Analysis Of Tin Selenide Films, R. D. Engelken, Jack L. Boone, A. Shahnazary

Electrical and Computer Engineering Faculty Research & Creative Works

Sn1±xSe films have been electrodeposited from aqueous solutions containing SnCl2 and ionically dissolved SeO2 or H2SeO3 and DMF solutions containing SnCl2 and molecularly dissolved selenium powder. The as-deposited films ranged from amorphous to polycrystalline and exhibited indirect or nondirect bandgaps from 0.85 to 0.95 eV. There was little difference between the appearance or material data of the films grown by the two techniques. Direct reaction between Sn++ and H2SeO3 or HSeO3_ in the aqueous solutions yielded a Se/SnxSe suspension/precipitate. Although this does not seem to have any serious effect on the deposition process, it does produce a decrease in the …

Growth Of Ultrafine Particles By Brownian Coagulation, S. H. Suck Salk, R. E. Thurman, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Current atmospheric observations tend to support the view that continental tropospheric aerosols (particularly urban aerosols) show multimodal mass distributions in the size range of 0.01-100 μm. The origin of these aerosols is both natural and anthropogenic. Recently, trimodal sub-μm size distributions from combustion measurements at 0.008, 0.035 and 0.15 μm were also observed. Our interest in the present study is the secondary process of growth of sub-μm size aerosols by the coagulation process alone. Using the 'J-space' (integer-space) distribution method of Salk (Suck) and Brock (1979, J. Aerosol Sci. 10, 58-590), we report an accurate numerical simulation study of the …

Nebraska Summary: S022 Case-Ih 485, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S004 Deutz-Allis 6250, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S003 Deutz-Allis 6240, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Permeability Testing In The Triaxial Cell., Gregory W. Carpenter, Richard W. Stephenson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

It Has Been Suggested that a Triaxial Shear Test Chamber Can Be Used to Measure the Permeability of Low Permeability Soils. to Verify This, the Influence of a Number of Test Parameters on the Measured Coefficient of Permeability Was Investigated. Results Indicate Such Permeability Tests Should Be Performed on Samples Having a Minimum Diameter of 71. 1 Mm (2. 8 In.) and a Length to Diameter Ratio of 0. 5 to 1. 0. It Was Found that a Permeant Consisting of 1 G of Magnesium Sulfate Heptahydrate (Epsom Salt) Dissolved in 1 L of Deaired, Distilled Water is Adequate for …

Lsim User Manual, Roger D. Chamberlain

All Computer Science and Engineering Research

Lsim is a gate/switch level digital logic similar. It enables users to model digital circuits both at the gate and switch level and incorporates features that support investigation of the simulation task itself. This user's manual describes the procedures used to specify a circuit to lsim and control the simulation of the circuit (i.e., specifying inputs vectors, running the simulation, and monitoring output signals).

Tspc/Dc Measurements On Barium Titanate, Harlan U. Anderson, Wayne Huebner

Materials Science and Engineering Faculty Research & Creative Works

Thermally-stimlated polarization / depolarization current (TSPC / DC) measurements were made on high-purity doped and undopod BaTiO3 as a function of applied field, heating rate, dopant level, and Ba:Ti ratio. The form of the TSPC/DC curves is dependent upon both the resistive and ferroelectric properties of BaTiO3. For TSPC spectra, current peaks are exhibited due to the change in in magnitude and direction of the spontaneous polarization with changing crystal structure. In particular, whether the phase transition is first or seoond order influsnaes the existence and magnitude of the current peaks. TSDC measurements are essentially dynamic pyroelectric measurements and as …

Development And Testing Of A Heuristic Line Balancing Program For A Microcomputer, Dean B. Creech

Retrospective Theses and Dissertations

Development, operation, and testing of a heuristic line balancing program for a microcomputer are discussed. Tasks are grouped into work stations along an assembly line such that the number of work stations required is minimized.

The model is built primarily using the Hoffman (1963) procedure with modifications described by Gehrlein and Patterson (1975). For purposes of comparison the Rank Positional Weight technique (Helgeson and Birnie, 1961) is also included in the model.

Testing included thirty-seven different balances using problems from the literature. For each balance, both Rank Positional Weight and Hoffmann solutions were obtained in the forward and reverse directions. …

Separation Plane Priority In Computer Image Generation, Keith A. Stump

Retrospective Theses and Dissertations

Flight simulators are devices in which air crews can be trained without the use of actual aircraft. Potentially dangerous maneuvers, such as air-to-air refueling, and destructive exercises, such as evasive action from weaponry or aerial dogfights, can be practiced repeatedly with no risk to pilot or crew. Flight simulators are cost effective since the fuel costs associated with training pilots in actual aircraft can be excessive. Flight simulators offer an alternate training method with reduced cost. The task of a visual flight simulator is to present the trainee with scenes representative of those that would be seen if the actual …

Numerical Simulation Of Air-Conditioning Heat Recovery Water Heating Systems, Amir H. Gorji

Retrospective Theses and Dissertations

A computer simulation program called TRNSYS (Transient System Simulation) was used to model two air-conditioning waste heat recovery water heating configurations. The first model is a heat recovery unit (HRU) that utilizes an 80-gallon storage tank in conjunction with a conventional home air-conditioning system. The second model is similar to the first, except that there is an additional 80-gallon preheat storage tank. An attempt was made to compare simulation results with experimental field data. However, due to problems encountered during the field tests, such as equipment and/or instrumentation failure, there were not enough experimental data to make a rigorous comparison. …

A Performance Comparison Of Solar Radiation Predictive Models For Both Fixed And Tracking Surfaces, William F. Marion

Retrospective Theses and Dissertations

Accurate performance prediction for a system utilizing solar energy requires accurate estimates of the solar radiation received by the collector surface. This thesis compares the performance of five different diffuse solar radiation models in estimating the diffuse radiation received by a tilted surface in the warm, humid climate of Central Florida.

The following models were studied: Isotropic Model, Temps and Coulson Model, Klucher Model, Hay Model, and Perez Model. The models were evaluated for both a fixed south facing surface and for three different tracking schemes suitable for photovoltaic applications. Model estimates were then compared to the solar radiation data …

A Zero Extraction And Separation Technique For Surface Acoustic Wave And Digital Signal Processing Fir Filter Implementation, Keith V. Lindsay

Retrospective Theses and Dissertations

Presented is a new method of separating the zeros of a Finite Impulse Response (FIR) filter producing optimal digital filter of surface acoustic wave (SAW) design implementation. Overviews of zero extraction algorithms and of FIR filter design using the Remez Exchange algorithm are presented (McClellen et al. 1973).

The computer aided design (CAD) procedure presented allows the designer to specify the general filter characteristic which the Remez algorithm translates to FIR time domain coefficients. These coefficients are readily translated to the frequency (z) domain, producing an Nth order polynomial in z. The characteristic polynomial is factored to determine all roots …

The Design And Implementation Of Surface Acoustic Wave Devices For Linear Fm And Nonlinear Fm Pulse Compression Technique For Radar Applications, James C. Walker

Retrospective Theses and Dissertations

The purpose of this work is to design, fabricate, and compare dispersive SAW devices using both linear FM and a new non-linear FM scheme. This new non-linear FM scheme uses the Blackman function as the modulating signal of the FM waveform. Up-chirped and V-chirped devices for both linear and the new non-linear FM scheme and their corresponding matched filters are compared.

Design considerations are discussed in detail. An efficient sampling algorithm (which can also be applied to other non-linearly modulated FM waveforms) developed to facilitate the design of the SAW devices is presented.

Switched-Capacitor Programmable Sallen And Key Lowpass Filters, Karl P. Eriksson

Retrospective Theses and Dissertations

This thesis deals with a different approach to switched-capacitor filters than previously seen by the use of a Sallen and Key topology. It is shown that a Sallen and Key second-order topology approach to a switched-capacitor filter gives reasonable filter performance results, contrary to what the literature leads one to expect. It is also shown that the Sallen and Key second-order topology with modification to a third-order section with buffers results in a high performance switched-capacitor filter with fewer components than previous switched-capacitor filters. This results in fewer monolithic chip size requirements, reduced power requirements, and less cost. Higher order …

Traffic Speed Report No. 119, David L. Cochran, Leroy Gray

JTRP Technical Reports

No abstract provided.

Studies On Controlled Low Strength Mortar, William Forrest Kepler

JTRP Technical Reports

No abstract provided.

Stabl5/Pc Stabl5 User Manual : Informational Report, James Richard Carpenter

JTRP Technical Reports

No abstract provided.

Traffic Speed Report No. 120, David L. Cochran, Leroy Gray

JTRP Technical Reports

No abstract provided.

Predicting Shunt Currents In Stacks Of Bipolar Plate Cells, Ralph E. White, C. W. Walton, H. S. Burney, R. N. Beaver

Faculty Publications

A method is presented for predicting shunt currents in stacks of undivided and divided bipolar plate cells. The method is an efficient way of solving the coupled sets of algebraic equations that arise from using circuit analog models to represent the current paths in stacks of undivided or divided bipolar plate cells. These algebraic equations can be eitherlinear or nonlinear depending upon the current-potential relationships used in the model (i.e., nonlinear circuit elements can be included). The method is used to show the importance of including nonsymmetrical resistances and nonlinear circuit elements in the models. Also, the method …

Direct Digital Control Of A Liquid Level/Temperature Control Unit, Pedro J. Claudio

Retrospective Theses and Dissertations

A direct digital control algorithm was implemented on a liquid level and temperature control unit. Two control schemes were implemented on the system and the results were compared against a fourth order Runge-Kutta solution.

Both control schemes involved proportional feedback with dynamic adjustment of the operating point. It was found that the control scheme that contained a feedforward component which dealt with the inlet water temperature had a superior dynamic response to setpoint changes. Steady state offsets in both control schemes were attributable to model parameter estimation errors. Differences between the actual and predicted system dynamic response were also attributable …

Cost Effective Design Of The Activated Sludge Wastewater Treatment System, Robert P. Huguenard

Retrospective Theses and Dissertations

In current design practice the components of the complete mix activated sludge system are designed as individual units with little or no appreciation for the process interactions which occur between system components. To achieve acceptable process efficiency and to realize cost effectiveness a unified design approach is necessary. This research effort was initiated to define the characteristics of the economic optimum complete mix activated sludge configuration while considering system interactions.

A computer program was developed for the completion of the process design and the economic analysis of the aeration basins, the settling basins, and the return sludge pumping facilities for …

A Peripheral Subsystem Optimized For Computer Image Generation Applications, John J. Bloomer

Retrospective Theses and Dissertations

Requirements for ever increasing realism in real time computer image generation for military mission and commercial training, have generated the need for a higher performance, more cost effective front-end processor. Current computer image generators front-end general purpose computers are reaching their performance limits in current architectures.

The tasks of this processor include: realtime computations, magnetic disk control, data transfer and direct memory access to and from the balance of the image generator. A new front-end processor system is under development. This multiple-bus, multiprocessor architecture in and of itself does not address disk and external data transfer. A peripheral subsystem is …

Transient Critical Heat Flux, Kemal O. Pasamehmetoglu

Retrospective Theses and Dissertations

The term Critical Heat Flux (CHF) is used in boiling heat transfer to describe the local value of the heat flux at which a characteristic reduction in heat transfer coefficient first occurs. In today’s technology, the CHF is a phenomenon related to the design and safety of various important devices.

A major limitation on the thermal design of a light-water reactor (LWR) is the necessity to maintain an adequate safety margin between the CHF and the local heat flux. Extended operations at local power levels in excess of the CHF can lead to high temperature oxidation and embrittlement or melting …