Digital Commons Network^™

Removal Of Colloidal Silica In Simulated Seawater By A Dynamic Multi-Short-Circuited Galvanic Cell, Jan E. Osterholm, Paul W. Kramer, Hlrotsugu K. Yasuda

Chemistry Faculty Research & Creative Works

A dynamic multi-short-circuited galvanic cell (MSCGC) with Pt-AI electrodes has been used to study the removal of colloidal silica from seawater as a pretreatment step for the desalination of seawater by use of reverse osmosis. The rate of silica removal is observed to be affected by the flow rate of the solution through the cell and the dissolved oxygen content of the solution as well as by the nature of the aluminum electrode surface and the number of contact points (short circuits) between the aluminum and platinum. The total silica content is reduced by 95 % by use of this …

Chapter 3 Coatings And Surface Modification Using Low Pressure Non-Equilibrium Plasmas, Harold F. Winters, Robert P.H. Chang, C. J. Mogab, John Evans, John A. Thornton, Hirotsugu Yasuda

Chemistry Faculty Research & Creative Works

No abstract provided.

Dynamic Structure Of N-Hexadecane Solubilized In A Nonionic Surfactant Bilayer Measured By Deuteron Magnetic Resonance, Anthony J.I. Ward, Stig Friberg, David W. Larsen, Shankar B. Rananavare

Chemistry Faculty Research & Creative Works

A 2H NMR study was made of the order parameters of n-hexadecane molecules solubilized up to 55% (w/w) in a lyotropic lamellar liquid crystal of tetra ethylene glycol n-dodecyl ether and water for a range of compositions of varying water and hydrocarbon content. The NMR data supported a model with only a small amount of penetration of the hydrocarbon between the amphiphilic molecules and a rapid exchange on the 2H NMR time scale between the penetrated segments and the nonpenetrating molecules which latter are essentially isotropic. © 1985, American Chemical Society. All rights reserved.

Plasma Polymerization Investigated By The Substrate Temperature Dependence., H. Yasuda, Cheng Wang

Chemistry Faculty Research & Creative Works

In the reported experiments, plasma polymerization of tetrafluoroethylene (TFE), perfluoro-2-butyl-tetrahydrofuran (PFBTHF), ethylene, and styrene were investigated in various combinations of monomer flow rates and discharge wattages for the substrate temperature range of minus 50 to 80 degree C. The polymer deposition rates can be generally expressed by k//o equals Ae** minus **b**t, where k//o is the specific deposition rate given by k//o equals (deposition rate)/(mass flow rate of monomer), A is the preexponential factor representing the extrapolated value of k//o at zero absolute temperature, and b is the temperature-dependence coefficient. It was found that the value of b is not …

Feasibility Study Of Fabricating Composite Ceramic Chamber Liners For Small Caliber Automatic Weapons, P. D. Ownby, D. V. Stewart

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Length-Thermal Stress Relations For Composite Bridges, Jack H. Emanuel, Charles M. Taylor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Computer-assisted analysis was used to study the relation among uniform, linear, and nonlinear stress components thermally induced in a composite bridge section for hypothetical parameters of varying span lengths, number of spans, and support conditions, as well as for actual bridges. The results were verified by conventional methods of analysis. The following was concluded for prismatic (constant) sections: (1) For constant proportionality of span lengths, each of the three thermal stress components is independent of span length; (2) variation of the proportionality of span lengths affects only the linear stress component; (3) support reactions and deflections caused by thermal loading …

Relative Durability Of Shale -- A Suggested Rating System, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The inability to predict the degradation tendencies of shale has resulted in numerous failures of projects where shale was used as a construction material. Because shale does not fit neatly into either a soil category or a rock category, the tests that are commonly used to classify soil or rock are in many instances not totally suitable for classifying shale as to its long-term behavior properties. Thus, special classification tests of shale types has become necessary. The durability or shale relates to how well it can withstand its changing environment and still retain its initial properties. Strength, expansion characteristics, and …

Unsteady-State Spherical Flow With Storage And Skin., Jeffrey A. Joseph, Leonard Koederitz

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This paper presents short-time interpretation methods for radial-spherical (or radial-hemispherical) flow in homogeneous and isotropic reservoirs inclusive of wellbore storage, wellbore phase redistribution, and damage skin effects. New dimensionless groups are introduced to facilitate the classic transformation from radial flow in the sphere to linear flow in the rod. Analytical expressions, type curves (in log-log and semi log format), and tabulated solutions are presented, both in terms of pressure and rate, for all flow problems considered. A new empirical equation to estimate the duration of wellbore and near-wellbore effects under spherical flow is also proposed.

Racial Differences In The Distribution Of Posterior Circulation Occlusive Disease, Philip B. Gorelick, Louis R. Caplan, Daniel B. Hier, Dushyant Patel, Patricia Langenberg, Michael S. Pessin, Jose Biller, David Kornack

Chemistry Faculty Research & Creative Works

We Compared Clinical and Arteriographic Features in 27 White and 24 Black Patients with Symptomatic Posterior Circulation Occlusive Disease. the Degree of Arterial Stenosis Was Measured Independently by Two Examiners at 12 Sites within the Vertebrobasilar Territory. Racial Comparisons Were Made based Upon the Distribution of Extra- and Intracranial Occlusive Lesions and Symptomatic Sites of the Lesions. White Patients Had Significantly More Angina Pectoris, More Lesions of the Origin of the Left Vertebral Artery and More High-Grade Lesions of the Extracranial Vertebral Arteries. Black Patients Had Significantly Higher Mean Diastolic Blood Pressure, More Diabetes Mellitus, More Lesions of the Distal …

Interobserver Variability In The Assessment Of Neurologic History And Examination In The Stroke Data Bank, David Shinar, Cynthia R. Gross, Jay P. Mohr, Louis R. Caplan, Thomas R. Price, Philip A. Wolf, Daniel B. Hier, Carlos S. Kase, Irene G. Fishman, Christine L. Wolf, Selma C. Kunitz

Chemistry Faculty Research & Creative Works

Interobserver Reliability in Obtaining Neurologic Histories and Examinations Was Investigated among Neurologists Collaborating in the Stroke Data Bank (SDB). Seventeen In-Hospital Stroke Patients Were Examined by Six Neurologists Experienced in Stroke over the Course of Three Days. Patients Were Examined Twice a Day for Two Successive Days, with Each Patient Seen by Four Different Neurologists. Data Were Recorded on SDB Forms, According to Definitions and Procedures Established for the SDB. Percent Agreement and Κ Coefficients Were Calculated to Assess the Levels of Agreement for Each Item. Important Differences in Levels of Agreement Were Found among Items on Both Neurologic History …

Evaluation Of A Near-Surface Low-Level Radioactive Waste Disposal Facility For The State Of Missouri, Christine Lang Nelson

Masters Theses

"A low-level radioactive waste disposal facility for the state of Missouri Is designed. The proposed facility Is to be placed in a mined opening within a Precambrian granite outcrop in southeastern Missouri.

A safety assessment of the proposed facility was performed. The method used was fault tree analysis.

The threat of seismic activity within the region ls seen to be the main determent to the proposed design. Groundwater modelling was not possible due to a lack of data.

The facility design Includes a provision for the retrieval of the low-level waste once the waste has decayed to acceptable levels"-- Abstract, …

Automated Evaluation Of Reservoir Parameters Applying Pressure Transient Theory, Steven Robert Homoky

Masters Theses

"This study presents an investigation to automatically evaluate reservoir parameters using pressure transient theory. Methods will be introduced to numerically fit the well test data in the real (time) domain (specifically the pressure change as a function of test time). The numerical fit and known fluid, rock and well properties will be used to evaluate the dimensionless storage coefficient. The theoretical dimensionless pressure (being a function of skin factor, permeability, and dimensionless storage coefficient) is obtained by Laplace Inversion. The ability to evaluate the dimensionless storage coefficient thus reduces the parameters of the pressure equation by one. Varying the skin …

Development Of Apparatus For Constant-Hydraulic-Gradient And Constant-Rate-Of-Strain Consolidation Tests, Jack F. Geerlings

Masters Theses

"A back pressure type consolidometer manufactured by Anteus Laboratory Equipment Company is modified to perform either constant hydraulic gradient or constant rate of strain consolidation tests. The modification of the consolidometer and its instrumentation are described. Computer software is developed for the purpose of apparatus control and for test data acquisition and analysis.

Constant hydraulic gradient and constant rate of strain consolidation tests are performed on samples consolidated from a slurry in the laboratory. Results of these tests are compared with incremental consolidation tests performed with an oedometer.

The modified apparatus was found to be suitable for use in both …

Carbonate Facies Of The Kimmswick Limestone (Trenton/Galena) In Southwestern Illinois : Their Relations As Oil Reservoirs And Traps, Gregory A. Crews

Masters Theses

"Four potentially productive oil horizons have been identified in the Kimmswick Limestone (Trenton/Galena), Ordovician of southwestern Illinois. Four non-porous caprock zones and four porous horizons were identified and informally named after corresponding members of the Dunleith Formation (Illinois State Geological Survey classification). The porous horizons generally consist of coarse-grained, fossiliferous limestone, which is overlain by finer grained, spar-cemented, impermeable limestone.

In order of production potential, the horizons are the upper Moredock, lower Moredock, Beecher-St. James (lowermost stratigraphic unit), and New London (uppermost stratigraphic unit). Porosity in the upper Moredock horizon is relatively consistent throughout the study area, as determined by …

Oxygen Absorption And Diffusion In Tissue, Bo Henrik Arve

Masters Theses

"A mathematical model which describes the diffusion of oxygen in absorbing tissue is presented. The model accounts for the presence of a moving boundary which marks the deepest penetration of oxygen into the absorbing medium and predicts the steady state and unsteady state distribution of oxygen through the absorbing tissue.

Results are shown for zeroth, half, first, one and a half, and second order rates of absorption as well as when the rate of absorption is described by the Michaelis - Menten equation.

The model predictions show that the total time for the moving boundary to recede to the surface …

A Theoretical Study Of Antecedent Soil Moisture As It Relates To The Rainfall-Runoff Relationship, Karen Sue Angert

Masters Theses

"This paper addresses the feasibility of using antecedent soil moisture as a tool for predicting the extractions from rainfall due to the infiltration process by solving the one-dimensional equation for saturated- unsaturated flow through porous media. Soil moisture characteristics in the form of empirical equations were used to incorporate the hysteretic behavior of the soil-water relationships into the model. Two sets of parameters were developed to be representative of a silty sand and a silty fine sand.

Extractions as infiltration from a given storm hyetograph and the total volume of direct runoff were computed for different initial moisture states. When …

Complex Reactions In Porous Media, Dar-Sen Horng

Masters Theses

"The dusty-gas model is used to describe the molar fluxes of complex irreversible reactions with moles changes in isothermal porous catalysts.

The model presented in this work can be used for any number of independent reactions occurring in porous media as long as the number of independent reactions is equal to or less than the total number of species.

Systems of two parallel reactions involving a ternary mixture is used in this work. Five sets of reaction parameters are used for each reaction system and the overall selectivity and effectiveness factors are calculated for different geometric constants.

Results show that …

Electric And Magnetic Field Induction On Parallel Transmission Lines, Robert Joseph Schnell

Masters Theses

"The theory behind electric and magnetic field induction is developed. The theory is then applied to the calculations of induced voltages and currents on a de-energized three phase transmission line paralleling an energized three phase transmission line. The effect of shield wires on the induction phenomena is explained. Interactive computer programs for both electric and magnetic field induction are presented and instructions given for their use. Both programs are stored on disks and are for use on an IBM (or compatible) personal computer. Example problems are posed and solved"--Abstract, page ii.

An Analysis Of Mill Sound Levels To Aid In The Control And Understanding Of The Grinding Process, Scott Douglas Morrison

Doctoral Dissertations

“An experimental study has been made to evaluate the relationships between grinding parameters and the directional sound levels emitted from the collision of the grinding media with the mill wall for a laboratory batch ball mill.

Discrete frequency and single frequency band sound pressure level measurements were performed to investigate the changes in sound levels with grind time. It was demonstrated that the reduction in sound levels with grind time observed for a narrow sized feed can be used to indicate optimum breakage rates, overall time-based particle size distribution, and ore character.

The relationships established with the discrete frequency and …

Corrosion In Magnesium And A Magnesium Alloy (Az91c) As Modified By Ion Implantation, Sanay Akavipat

Doctoral Dissertations

"Magnesium and a magnesium alloy (AZ9 1C) have been ion implanted over a range of ion s energies (50 to 150 keV) and doses (1 x 10¹⁶ to 2 x 10¹⁷ ions/cm²) to modify the corrosion properties of the metals. The corrosion tests were done by anodic polarization in chloride -free and chloride containing aqueous solutions of a borated-boric acid with a pH of 9.3. Anodic polarization measurements showed that some implantations could greatly reduce the corrosion current densities at all impressed voltages and also increased slightly the pitting potential, which indicated the onset of the …

Dissolution Of Multi-Component Systems, Robin Ashley Murphy

Doctoral Dissertations

"The validity of ideal barrier layer diffusion kinetics was examined in the NaCl/KCl - glycerol and Al₂O₃-CaO-Al₂O₃-SiO₂/slag corrosion systems. Single crystals and dense polycrystalline plates of pure NaCl or KCl exhibit steady-state corrosion rates within 10%, of calculated theoretical values, while dense mixtures of the two salts corrode at rates higher than either pure material. The results are compared to the grooving phenomena of NaCl/KCl bicrystals.

Polycrystalline Al₂O₃ is shown to corrode at the same rate as single crystal sapphire at 1400°C in CaO-SiO₂-Al_{2 …}

Numerical Simulation Of Mixing Processes In Two-Dimensional Channel Flows, Milan Karel Straka

Doctoral Dissertations

"Recently, considerable interest has arisen in the numerical simulation of laminar and turbulent transport phenomena. More knowledge in this field is needed to improve predictions of heat and mass transfer processes in a variety of technical fields.

In this work a new computationally efficient transport model is developed. It consists of partially parabolized time-dependent equations of motion, continuity, and concentration of nonconservative species. Pertinent equations are solved numerically for both laminar and turbulent flow.

Results of calculations of laminar flow in the entry region of a parallel-plate channel agree well with the work of other authors. For turbulent flows, the …

Measurement Of The Far Infrared Optical Properties Of Steel, Aluminum, Evaporated Iron, And Teflon Fep, Raymond E. Paul

Doctoral Dissertations

"The optical properties of low-carbon shim steel, aluminum foil, and Teflon FEP have been measured in the 20 cm^-1 to 70 cm^-1 range. In particular, measurements of surface impedance for aluminum and low-carbon steel were used to calculate the imaginary part of the dielectric constant (&_{m, 2}). The resulting values of &_{m, 2} were of order 10⁶ for aluminum, and 10⁵ for steel. The imaginary part of the dielectric constant for metals is several times greater in magnitude than the real part in the frequency range of this experiment. Calculations of &_{m, …}

Optical Properties Of Natural Minerals In The Far-Infrared, Larry Lavern Long

Doctoral Dissertations

"The reflectivity of natural mineral powders were measured in the far infrared. The complex indices of refraction were then determined by Kramers-Kronig analysis or dispersive analysis. The samples were constructed by pressing the powdered sample into a 13 mm diameter pellet. A few of the samples that were measured were kaolin, illite, and montmorillonite, clay samples that could not be obtained in large single crystals. For calcite and gypsum crystals a comparison between the single crystal measurements and powder measurements was done to determine the effect of sample preparation on the measured spectra"-- Abstract, p. ii

A Parallel Branch And Bound Algorithm For Integer Linear Programming Models, Rochelle L. Boehning

Doctoral Dissertations

"A parallel branch and bound algorithm is developed for use with MIMD computers to study the efficiency of parallel processors on general integer linear programming problems. The Haldi and IBM test problems and a System Design model are used in the implementation of the algorithm. Initially the algorithm solves the Haldi and IBM test problems on a single processor computer which simulates a multiple processor computer. The algorithm is then implemented on the Denelcor HEP multiprocessor using two of the IBM problems to compare the results of the simulation to the results using an MIMD computer. Finally the algorithm is …

Kinetics And Reactor Design In The Pyrolysis Of Tar Sands, Charles Arthur Lechner

Doctoral Dissertations

"Data from the thermal decomposition of bitumen from Utah tar sands was obtained and analysed with both isothermal and non-isothermal chemical reaction models. The use of a power rate law to describe the complex kinetics of pyrolysis gave agreement with the experimental data that was approximate, but adequate for design purposes. The results indicated a reaction rate that was second order in bitumen content, with an activation energy of about 17 to 20 kcal/gmol.

Data for the boiling point distribution of the products was consistent with a change of mechanism from vaporization to pyrolysis as the samples are heated. Higher …

Electrochemical Evaluation Of Zinc Electrolyte, Rajesh Kumar Singh

Doctoral Dissertations

"The polarization characteristics of acidified zinc sulfate electrolyte with varying solution chemistries were examined by cyclic voltammetry. An attempt was made to correlate the polarization results with the morphological and current efficiency data in order to develop a better understanding of the more fundamental aspects of impurity and additive behavior during the zinc electrodeposition process.

A statistical screening design program was conducted to determine the effects of certain operating parameters on the nucleation potential of zinc from sulfate electrolyte. The variables studied included: solution temperature, H₂SO₄ and Zn concentration, and scan rate. The solution temperature was found to be the …

Mass Transport Considerations In Electrometallurgical Reactions, Jose Rolando Sami Cuzmar

Doctoral Dissertations

"The research program described is divided into three segments. In the first part, the morphology and kinetic studies of Cd²⁺ removal from ZnSO₄ solutions using Zn dust as a reducing agent are presented. In the absence of impurities, the morphology of the Cd deposit shows the formation of two-dimensional or leaf-like dendrites capable of interlocking and forming agglomerates or balls. The size and strength of the agglomerates depend on the initial Cd²⁺ concentration to Zn metal surface area ratio, the rate of Cd ²⁺ removal, and the reactor geometry. The presence of additives, like Cu²⁺ and …

The Missouri Miner, December 06, 1984

The Missouri Miner Newspaper

No abstract provided.

Survey Of Routing Algorithms For Computer Networks, Lu Yu, Thomas J. Sager

Computer Science Technical Reports

This thesis gives a general discussion of routing for computer networks, followed by an overview of a number of typical routing algorithms used or reported in the past few years. Attention is mainly focused on distributed adaptive routing algorithms for packet switching (or message switching) networks. Algorithms for major commercial networks (or network architectures) are reviewed as well, for the convenience of comparison.