Engineering Commons^™

An Investigation Of Signs For Median Crossovers, Gillian M. Worsey

Doctoral Dissertations

“This paper describes a study of advance warning signs for median crossovers on divided highways. Candidate crossover signs were identified from a literature review, survey of current State practices and discussions with FHWA personnel. Seven of these signs were selected for further testing in a laboratory study for legibility, understanding and driver preference. Sixty subjects representing a cross-section of drivers took part in the study, thirty at the Turner-Fairbanks Highway Research Center in McLean, Virginia and thirty at the University of Missouri--Rolla in Rolla, Missouri.

Two of the seven signs were word messages and five were symbolic signs. The results …

Linear Process Calculations As Convergence Accelerators In Flowsheet‐Sequenced Programs, S. M. Milani, Marshall E. Findley

Chemical and Biochemical Engineering Faculty Research & Creative Works

Linear process calculations were developed for use in conjunction with flow‐sheet‐sequenced calculations, as methods of convergence acceleration. Two such methods were compared with the successive substitution and Wegstein methods on relatively simple processes. "Linear Process Simulation," which requires user‐derived equations, produced the best results. Copyright © 1986 American Institute of Chemical Engineers

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 …

Elasto-Composition Waves In Inhomogeneous Solids, R. C. Batra, Manfred Wuttig

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

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 …

Preparation Of Perovskite Pb(Mg1/3nb2/3)03 Using Pb3nb208 And Mgo, Jyoti P. Guha, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The synthesis of perovskite Pb(Mg1/3Nb2/3)O3 from an equimolar mixture of Pb3Nb208 and MgO was studied by solid‐state reaction techniques. An addition of 1 wt% excess MgO to the stoichiometric composition enhances the formation of the cubic perovskite phase. The absence of free PbO in the initial starting materials minimizes the volatilization loss during firing, thereby reducing the possibility of any compositional change and resulting in a substantial improvement of the perovskite phase purity over the conventional mixed‐oxide processing. Copyright © 1986, Wiley Blackwell. All rights reserved

Alternate Presentation Of Fourier Transform Development From Fourier Series., Gordon E. Carlson

Electrical and Computer Engineering Faculty Research & Creative Works

An alternate presentation of the development of the Fourier transform from the complex exponential Fourier series is presented. It uses spectral concepts to aid the mathematical development and a redefined spectral form for the spectral information obtained with the Fourier series. It has been used a number of times in the classroom and has been found to aid the students' understanding of the Fourier transform and the spectra of an aperiodic signal.

An Interactive Power System Analyzer With Graphics For Educational Use, Chin Hwanglo, 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 …

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 …

A New Automated Pulse Testing Analysis Method Applying Inflection Point Theory, Jose Maria Donoso

Masters Theses

"This paper describes a new technique for pulse test analysis that combines the simplicity of the tangent method with the result repeatability of the iterative methods. Inflection points are used instead of time lag with the added advantage that they are calculated by a simple algorithm and are not subject to graphical misinterpretation. Charts are made for the calculation of transmissibility and storage for unequal pulse and shut-in periods from 0.1 to 0.9 relating inflection time to pulse response amplitude and dimensionless inflection time.

The graphs presented for this technique have the same dimensionless cycle period ranges (from 0.44 to …

A New Basin Characteristic For Use In Estimating Impervious Area And Flood Discharges In Urban Missouri Basins, Rodney E. Southard

Masters Theses

"A previous regression analysis of flood peaks on urban basins in St. Louis County, Missouri, indicated that the percentage of impervious area and drainage area were the only basin characteristics of statistical significance in estimating the 2-, 5-, 10-, 25-, 50-, and 100-year peak-flow discharges at ungaged urban basins. In this statewide regression analysis of urban basins, a new basin characteristic called the percentage of developed area was computed and used in a simple regression analysis. The regression analysis included percentage of developed area as the independent variable and impervious area as the dependent variable, resulting in a simplified procedure …

Fuel Loading For A Low-Leakage Core In A Pressurized Water Reactor, Omar Ivan Aguilar

Masters Theses

"A study of low-leakage core fuel loading as a means to reduce fast neutron flux incident upon the pressure vessel is presented. The specific case under study is Cycle 5 of Arkansas Nuclear One - Unit Two (ANO-2), a Combustion Engineering Pressurized Water Reactor. Neutron transport calculations were performed using the DOT two-dimensional transport code. The results from DOT provide the angular distribution of the fast neutron flux at the surface of the pressure vessel.

Seven different fuel loading schemes were studied and compared to the Reference Case. The angular distribution of the fast neutron flux for all cases studied …

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 …

The Effect Of Oxygen Partial Pressure On Oxygen And Carbon Incorporation In Czochralski Grown Single Crystal Silicon, Paul Shane Carter

Masters Theses

"The study herein detailed was made to determine the effect of varying the oxygen partial pressure of a Czochralski type crystal pulling furnace using conventional hardware and remelt silicon on the level of incorporated oxygen and carbon in the single crystal. The oxygen partial pressure was measured by a zirconia type oxygen sensor and controlled by additions of hydrogen or carbon dioxide to the argon purge gas. The oxygen and carbon incorporation measurements were made by the Fourier Transform Infrared (FTIR) method, using the American Standard for Testing Materials (ASTM) standard calibration.

During the study boules which were zero dislocation …

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 …

A Two-Dimensional, Three-Phase Reservoir Simulator Using The Impes Formulation, Ralph Ross Roesler

Masters Theses

"A numerical model for two dimensional, three-phase fluid flow has been developed using the IMPES formulation. Reservoir heterogeneities have been included, such as areal variations in porosity, permeability, thickness, and depth from a reference point. The model can also solve the problem of variable bubble points.

To check the accuracy of the model, a comparison was made with the Buckley-Leverett technique of predicting waterflood performance. The reservoir in the comparison is a 40 acre five spot with an initial gas saturation of 15 percent. The study shows that the two models are in good agreement, except for differences due to …

A Study Of Problem Lead-Zinc Ores Of Southeast Missouri In Terms Of Mineralogy And Galena Oxidation, Michael G. Schroer

Masters Theses

"Recovery problems encountered at some of the St. Joe Lead Company's milling facilities prompted the study of 6 different ores. High and low grade ores had characteristics that varied from poor lead - zinc selectivity to excessive lead losses to the flotation tailings. Three ores from both the Fletcher and Viburnum mills were studied through flotation tests, mill water analysis, and ore analysis using an ore microscope.

The major cause for poor recovery was found to be due to ore oxidation. Not only was lead, in the form of oxides, reporting to the tails, but high levels of copper ions …

A Purchase Estimator For Oil And Gas Reserves, Ronald Ernest Robbins

Masters Theses

"A computerized means for analyzing the profitability and purchase potential of producing oil and gas properties was developed. LOTUS 1- 2-3, a computerized spreadsheet package, was utilized in this development. The basic input data required for the implementation of the purchase estimator (BUYOUT) are the forecasts of production, price, and expense. BUYOUT itself is composed of three separate, but interactive, parts: and the system macro. the profitability model, the acquisition table,

A before federal income tax cash-flow model and several economic indicators constitute the profitability model. The profitability model is then fully interactive with an acquisition table which contains six …

Dimensional Change Correlations For 20% Cold Worked Aisi 316 Stainless Steel For Fusion Applications, Robert Wayne Clark

Masters Theses

"Dimensional instability of structural components in a fusion reactor Is expected to occur during Its operation. This expectation is based upon experience with fast reactors In the United States, France and United Kingdom. Correlations for void swelling and Irradiation creep are developed in this thesis for 20% cold worked AISI 316 Stainless Steel for fusion applications.

The sensitivities of swelling to variations in composition, fabrication and the Irradiation environment I le al roost exclusively in the duration of the transient regime of swelling. Irradiation creep rates at high exposures are also expected to exhibit a similar parametric insensitivity, largely because …

Characteristics Of A Stirred Bed Reactor Used For Gas-Solid Reactions, Christine Joy Beyke

Masters Theses

“A fluidized bed gas-solid reactor was designed and tested in which most of the fluidization energy is provided by a helical stirrer, with gas being used primarily as a reactant. The bulk gas in which the particles are suspended is practically constant in composition except for the area immediately adjacent to the gas inlet. The reactor is capable of withstanding temperatures up to at least 800°C and can be used with a wide range of flow rates. It is intended primarily as a laboratory tool, with the potential to be scaled up to multikilogram size.

The reactoor is a useful …

Influence Of Oxygen Activity On The Lattice Parameters And Thermal Expansion Of Mg And Sr-Doped Lacro₃, Sutham Srilomsak

Masters Theses

"Lanthanum Chromite, when used as the fuel cell interconnector material is exposed to extremely different oxygen activities on its two surfaces. In addition, it must also form coherent boundaries with the fuel electrode (anode) and air electrode (cathode) layers. In order to accomplish these functions the acceptor doped LaCrO₃ must not only be chemically stable over large oxygen activity ranges, but also have good thermal expansion coefficient of match with both the anode and cathode. Therefore, the objective of this study is to investigate these requirements for Mg and Sr doped LaCrO₃. The study was divided into …

Bearing Capacity Of Shallow Foundations, Yassin Taissir Al-Kour

Masters Theses

"Several bearing capacity theories have been reviewed in this analysis. However, only Meyerhof's theory is considered in great detail. Bearing capacity factors N_c, N_q, and N_γ have been computed based on Meyerhof's plasticity theory and the minimum passive earth pressures have been found by iterative calculations at all grid locations.

A computer program was developed to run Meyerhof's analysis on the IBM-Personal Computer. His previous charts were not totally satisfactory, because certain geometry was ignored. The computer program considers surface and shallow foundations with various values of degree of mobilization and ratios of depth-to-width of …

Measurement Of The Dusty Gas Model Parameters For Activated Carbon, Philip James Gloor

Masters Theses

"Included in the dusty gas equation are three constants, C₀, C₁ and C₂, which depend only upon the porous medium. Values for C₀ and C₁ can be obtained for a particular porous material by performing pure gas flow experiments and a value for C₂ can be obtained for the same material by performing Wicke-Kallenbach experiments. In this work, values for the dusty gas model parameters, for activated carbon, were obtained by performing the necessary experiments. The design and operation of the experimental equipment is presented along with the results obtained. The activated …

Commercial Design Of Four Indirect-Fired Fluidized Bed Gasifer Systems, Eoin Myles Clancy

Masters Theses

"This thesis deals with the design and cost analysis of four scaled up gasification plants. Reactor outputs range from 10 to 40 million Btu/hr (heating value of gas). Scale-up design parameters are based on data obtained from a 20 inch indirectly heated steam fluidized bed gasifier. This produces a medium Btu gas (450 Btu/ft³). The gas may be burnt on site or used as a chemical feedstock.

The plant designs consider reactor sizes, steam plant dimensions, specifications for feedhoppers, cyclones, conveying equipment, internal firetube heat exchangers, and drying plants.

The economic analysis deals with the cost of the …

Expert System Technology Applied To The Sensor Allocation Problem For Multisensor Integration, Edwin Rowe Carney

Masters Theses

"The use of multiple sensors for target acquisition provides both redundant and complementary coverage of the target observation space. To effectively utilize the sensor suite and to reduce the number of operator tasks, a high level of automation is required. An expert system is used to control the sensor suite. The expert system acts as an interface between the operator and the multisensory system. The sensors and their modes of operation are selected by the expert system. The mode selections are dependent upon the operator objective, the environment, and the physical and logical constraints of the system. The goal is …

Water Desalination Using Nocturnal Radiation Cooling, Ali Mufarreh Saleh Al-Amri

Masters Theses

"In this investigation nocturnal radiation condensation cooling is considered to determine the possibility of using this method as a desalination process in remote areas, villages and resorts, etc. An experimental study was made and programs were developed to calculate water collection under ideal conditions. Both experimental and theoretical work indicated that this process is useful for small scale water production where there is no available energy sources. It can be used also in conjunction with solar desalination processes. Cost analysis and a preliminary design are included"--Abstract, page ii.

Determining The Modified Derivative In Pressure Analysis, Scott Michael Frailey

Masters Theses

"The derivative type of curve technique of Bourdet for analyzing pressure tests requires calculating the derivative of the storage plot. Four numerical methods are used to evaluate the derivative: a five-point formula, Richardson's Extrapolation, a parabolic fit, and a central difference procedure. The parabolic fit and the central difference technique are good methods of determining the derivative. The effects of logarithmic s pacing of the data, using a central difference method, are studied. An investigation of the second derivative and the integral is conducted"-- Abstract, p. ii

Automation Of A High-Potential Test Instrument, Jeffery D. Breshears

Masters Theses

"Microcomputer controlled automation of a high-potential test set is presented. The design and development of a controller, the support circuits used to interface between the existing electronics and the controller, the IEEE-488 Bus Interface, and a new control panel design with options for manual, automatic, or computer-controlled operation of the instrument are given. Software subroutine listings which exemplify the computer-automation feature of the instrument are also presented. Recommendations for modification and improvement of the given design conclude the paper"--Abstract, page ii.

An Investigation Of The Low Voltage Failure Mechanism In Multilayer Ceramic Capacitors, Christopher John Brannon

Masters Theses

"Enhanced leakage current was induced into multilayer ceramic capacitors by the introduction of micro-cracks. These cracks extended from the surface through the electrode layers and were formed by means of thermal shock. The capacitors were then exposed to a low voltage bias and a humid atmosphere. Results indicated that a simple electrolytic solution mechanism may be responsible for the increased conduction, and that the proposed dendritic growth mechanisms may be more complex than necessary"--Abstract, p. ii