Physical Sciences and Mathematics Commons^™

A Study Of A New Hydrometallurgical Treatment For New Lead Belt Chalcopyrite Concentrates, Larry Steven Livingston

Masters Theses

"A two-phase research project was conducted on chalcopyrite concentrates from the New Lead Belt of Missouri. Phase one includes an ore microscopy study of the Magmont and Viburnum chalcopyrite concentrates in respect to mineralogy, particle size and interlocking characteristics of ore minerals and their possible relationships to poor chalcopyrite-galena separation in the copper flotation circuits.

Results of the ore microscopy study of the Magmont and Viburnum mines chalcopyrite concentrates suggest that interlocking of chalcopyrite and galena are not the cause of poor chalcopyrite-galena separation in the copper flotation circuits.

The most common sulfides found in the Magmont and Viburnum chalcopyrite …

Monte Carlo Simulation Of Confidence Intervals For Reliability, Kathryn Palisch Berkbigler

Masters Theses

"A computer program which computes fiducial confidence intervals for reliability by Monte Carlo simulation has been written. The program has the capability of computing these intervals for general systems of series, parallel, and mixed series and parallel subsystems which have failure time distributions which are either exponential, Weibull, gamma, normal, or lognormal.

Comparison of the simulation technique with a Bayesian technique for computing confidence intervals in the case of a series of exponentially distributed components shows that the two methods agree quite well when a fiducial prior distribution for reliability is used in the Bayesian technique. A uniform prior distribution …

Model Correction For The Formation Of Amorphous Silicon By Ion Implantation, John Robert Dennis

Masters Theses

"ESR has been used to study the formation of an amorphous layer in silicon by ion implantation. The room temperature implants were done at 20 keV with low dose rates. The critical dose was determined as a function of ion mass for six different ion species. Our experimental heavy ion results agree with those found by other ESR investigators at higher energy, but are not the same for light ions. However, our light and heavy ion results agree with electron microscope measurements for low energy implants. An energy-independent model for the formation of amorphous silicon by ion implantation has …

Corals Of The St. Louis Limestone In The Area Of Calhoun County, Illinois And St. Louis County, Missouri, William Earl Collins

Masters Theses

"The St. Louis Limestone and its equivalent formations crop out from Alaska south to Sonora and from Arizona east to Virginia. The St. Louis, in most cases, is fossiliferous and contains numerous species of foraminifers, echinoderms, bryozoans, molluscans, brachipods, arthropods and coelenterates. Algal mounds and mats are common. The rugose coral fauna of the Middle Mississippian (Meramecian) St. Louis Limestone of southern Calhoun County, Illinois and northern St. Louis County, Missouri was studied to determine first what corals were present and second the validity of the names assigned to the previously described species. It was found that the binomen for …

The Design And Calibration Of A Vibrating Sample Magnetometer, Donald Dwight Hoffman

Masters Theses

"The design and calibration of a vibrating sample magnetometer is described. The sample motion was in the direction of the external magnetic field which was produced by a superconducting solenoid. The maximum external magnetic field was 70 kilogauss. Sample temperature could be varied from 77°K to 1000°K with a vacuum jacketed furnace. The maximum temperature was obtained with approximately 27 watts. The instrument was calibrated to 1% with a spherical nickel sample"--Abstract, page ii.

A Study Of The Ability Of Surface Active Materials To Increase The Evaporation Rates Of Small, Freely Falling Water Drops, David Alan Sierawski

Masters Theses

"The evaporation rate at 30°C of water droplets partially covered by surface active materials (SAM) were determined. While two of the SAM were studied at a single dew point depression (ΔT_DP), seven others were examined over a range of ΔT_DP values. It was found, by comparison with pure water drops under identical conditions, that SAM increases the evaporation rate as compared to the rate of an uncontaminated drop. The lack of effect of the hydrophobic chain length and the possible effect of the hydrophilic group on this phenomenon are discussed. The explanation proposed is that at 30°C …

Heavy Metal Analysis Of Stream Sediments In The James River Basin, Missouri, William J. Head

Masters Theses

"A reconnaissance survey of stream sediments using the minus 80 mesh sieve fraction was made at 53 sites throughout the James River basin, Missouri. Sample sites within the 1460 square miles of the basin were chosen at tributary confluences, suspected contamination sources, and known areas of mineralization. Replicates and stream profiles were taken to check for analytical variation and reproducibility of results. Sediment samples were prepared by a hot nitric acid leach method. The sediments were analyzed using an atomic absorption unit to determine Cu, Pb, Zn, and Cd trace metal contents.

Values of selected streams within the basin were …

Temperature Dependence Of The Formation Of An Amorphous Layer In Ion-Implanted Silicon, Gary Keith Woodward

Masters Theses

"Electron spin resonance (ESR) has been used to study the temperature dependence of the formation of an amorphous damaged layer produced by ion implantation in silicon.

Undoped silicon wafers were implanted with N⁺, Ar⁺, and Kr⁺ ions at 20 keV and dose rates less than .36 µa/cm². Implant temperatures ranged from room temperature to 250°C. ESR measurements were made at room temperature on these wafers. The only ESR signal found was that associated with amorphous silicon. The ESR signal amplitude for a given ion and temperature increased approximately linearly with dose up to …

Distribution Of Trace Elements In Host Rock Limestone In The Tri-State Zinc-Lead District, Dinesh Jashbhai Patel

Masters Theses

"The trace metal contents of limestone in the Tri-State zinc-lead district were determined within a single horizon, the M bed. Ninety-six specimens, collected for a previous study of their petrographic character, were analyzed for zinc, lead, and copper using atomic absorption spectrophotometric techniques.

The unaltered M bed limestone at a distance from ore bodies was found to contain only 12-28 ppm zinc, 40-SO ppm lead and 12 ppm or less copper. Those limestone specimens which were found b earlier petrographic study to be altered principally to sparry calcite commonly contain anomalous amounts of zinc and lead. Some also have slightly …

Structure And Chemical Composition Of The Otoliths Of Cyprinus Carpio, Larry Paul Coen

Masters Theses

"The need for the study of microfossils such as foraminifera, conodonts, and otoliths as stratigraphic tools has been well established. However, disarticulated parts such as otoliths and conodonts cannot be effectively used unless they can be recognized. Otoliths, although somewhat unrecognized in the geological record, are far more abundant than articulated skeletons (Frizzell, 1965, p. 86). Therefore, much investigation is being conducted to reveal the origin, function, morphology, and usefulness of the otoliths of fishes.

In this investigation, the asteriscus, well developed only in Ostariophysins (of which the carp is a member), is studied for morphology. New tentative terms are …

Desorption Of Phosphorus From Si (111) Surfaces, Cesar Michel Magnin

Masters Theses

"Auger electron spectroscopy and mass analysis are used as complementary methods in evaluating desorption kinetics. For phosphorus on silicon, the order of desorption and activation energies of desorption are determined from continuously monitored phosphorus Auger electron signals during heating. These measurements indicate that diatomic phosphorus dissociates when adsorbed onto clean silicon. Mass spectrometer flash desorption spectra show that at least four distinct surface bonds are associated with the desorption of phosphorus. The dominant desorbed species is diatomic phosphorus at high coverage (> 0. 1 monolayer) and atomic phosphorus at low coverage (< 0.07 monolayer)"--Abstract, page ii.

Multispectral Analysis Of Erts Imagery By Color Enhancement, John F. Peters

Masters Theses

"The Earth Resources Technology Satellite (ERTS) program has supplied the scientist with high resolution multispectral imagery of a large portion or the earth. Photographic and electronic methods of image enhancement are not universally available to those who might profit from such endeavors.

Diazo products were found to be satisfactory for creation of false color enhancement of ERTS multispectral data. The purpose of the enhancement was to make the Diazochrome composite comparable to more sophisticated methods for the purpose of interpretation. The basis of the enhancement was the standard false color infrared composite, with negative and positive Diazochrome masks to enhance …

The Contribution Of Phonon-Induced Tunneling To Donor Esr Spectral Narrowing In Semiconductors, David Lawrence Meier

Masters Theses

"The narrowing of donor electron spin resonance spectra with increasing donor concentration N_D and increasing temperature T has been observed in semiconductors in the past. One proposed explanation for this phenomenon has been narrowing due to electron motion caused by phonon-induced tunneling (hopping) between donor sites. According to the Anderson narrowing theory, the line width of the narrowed line can be expressed in terms of the average square spread of the non-narrowed spectrum, < H²>_ave, and the average frequency of electron motion, ω_n. Previous work has been done on narrowing by hopping, but rigorous expressions for ω …

Heavy Metal Concentrations In The Waters Of The Springfield Area, Missouri, Anita Louise Williams

Masters Theses

"Water samples consisting of streams, springs, lakes, deep wells, and shallow wells were collected from various locations around the Springfield area. These were analysed for concentrations of the heavy metals of lead, copper, cadmium, zinc, mercury, and iron. Heavy metal contents in the waters occasionally show local concentrations. The zinc content can be related to known minor mineralized areas around Springfield. Some iron content in the surface waters and shallow aquifers is contributed by the iron-bearing clays and pyrites in the shallow formations.

The ranges of heavy metal values in the Springfield area are in ppb: lead, 1 to 70; …

Adsorption Of Water On Gold, Jean-Marc Louis Deschanel

Masters Theses

"Water adsorption isotherms on gold films were measured with a quartz crystal microbalance. Two gold films were studied: a "dirty" gold film contaminated by approximately one monolayer of carbon, and a "clean" gold film prepared by evaporating gold from a heated tungsten wire under high vacuum.

Water was found to chemisorb on both films according to a Freundlich type adsorption isotherm. Isosteric heats of adsorption were computed from the isotherm data. On the "clean" gold surface the isosteric heat showed a logarithmic decrease with increasing water coverage. The highest measured value for the heat of adsorption was 35 kcal mole …

Heavy Metals In The Main Streams Of The James River Basin, Missouri, Richard Jerome Lance

Masters Theses

"Demands on water resources in the James River basin have greatly increased. Industrial plants and lead-zinc prospects in the basin are potential sources of heavy metal additions to the waters of the area. The study determines the heavy metal content and distribution in the streams of the basin.

Approximately 50 water samples were collected each season and analyzed by atomic absorption techniques. Field determinations of temperature, specific conductance, pH, and effective alkalinity were also made.

Ranges of heavy metal content were: (1) mercury- <0. 1 to 0.3 ppb (summer only); (2) zinc-

The urban areas of Springfield contribute dissolved heavy metals to the surface streams. The Southwest Springfield Sewage …