Physical Sciences and Mathematics Commons^™

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 …

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 …

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 …

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.

Synthesis And Chemistry Of Thione-Iron Carbonyl Complexes, Albert Shil-Kwan Chan

Graduate Dissertations and Theses

The first examples of sulfur-donor ligand ortho-metallated complexes were obtained in good to excellent yields by reaction of various thiobenzophenones and a thiobenzoate with diiron enneacarbonyl in benzene at room temperature. The known trinuclear complex S₂Fe₃(CO)₉ was a by-product of these reactions, and complexes of the type (Ar₂C)S₂Fe₂(CO)₆ were formed in several instances. The structures of these complexes were established on the basis of microanalytical and spectral data as well as by reductive cleavage experiments. Oxidative or photolytic cleavage of the ortho-metallated complexes provides a convenient …

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.

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 …

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 …

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 …

Applications Of New Methods Of Structure Determination, Richard Earl Wagner

Electronic Theses and Dissertations

The structures of: 1) 2-piperidino-5-chlorornethyl-5-rnethyl-2- oxo-1, 3,2-dioxaphosphorinan; 2) 2-phenoxy-5-chloromethyl-5-methyl-2- oxo-1, 3,2-dioxaphosphorinan; 3) 2-p-bromophenoxy-5-chloromethyl-5- chloromethyl-5-methyl-2-oxo-1, 3, 2-dioxaphosphorinan have been resolved by x-ray single crystal studies. A Picker 4 circle diffractometer employing molybdenum x-rays and a zirconium filter was used to obtain accurate data. The space group of the first two compounds is P2₁/c while that of the third is Pca2₁. The lattice constants of the compounds are: 1) a = 10.035(8)Å, b = 6.503(4), c = 20.19(1), β = 96.8(3)°; 2) a = 6.237(3)Å, b = 11.437(5), c = 19.419(9), β = 109.95(3); and 3) a = …

Chemical Survey Of Selected South Dakota Lake Sediments, Alan Ross Swanson

Electronic Theses and Dissertations

Available phosphorus, organic carbon, and organic nitrogen were measured in bottom sediments of 16 lakes and ponds in northeast South Dakota. These lakes were glaciated, relatively shallow, and productive. Ranges of the surface sediments were: available phosphorus, 2 to 42 ppm; organic carbon, 0.94 to 5.34 percent; and organic nitrogen, 0.29 to 0.79 percent. Ranges of subsurface sediments were: available phosphorus, 2 to 39 ppm; organic carbon, 0.54 to 6.06 percent; organic nitrogen, 0.19 to 0.88 percent. Concentrations in most lakes varied little from top to bottom. Hard-bottomed lakes generally decreased in nutrient concentrations from sediment surface of subsurface. Lower …

Origin And Transport Of Nutrients In The Upper Big Sioux River, South Dakota, Charles William Thompson

Electronic Theses and Dissertations

The upper Big Sioux River Basin, in northeastern South Dakota, was studied to determine the origin and transport of nutrients in the Big Sioux River. The area was divided into three segments. Two of the segments, the Big Sioux River and Willow Creek Basins, were primarily agricultural drainage areas, and one segment was the city of Watertown. Sampling stations were selected to facilitate the determination of nutrient inputs to the river from each of these segments and to determine the nutrient load in the river leaving the study area. Nutrients studied included total orthophosphate and the particulate and dissolved fractions …

Evaluation Of Cattle Use Of A Deer Winter Range In The Black Hills, David C. Hamm

Electronic Theses and Dissertations

Cattle use of a deer winter range in the Black Hills was investigated during the summer grazing seasons of 1971-1972. A U.S. Forest Service grazing allotment situated between Mystic and Redfern, South Dakota, was used as the study area. The allotment was divided into five grazing units or pastures managed collectively under a “rest-rotation” system of grazing. Three study sites were selected in each unit of the allotment, and 75 exclosures were erected on each site; a paired-plot method was used to collect data. Indices to use of sites by deer and cattle were obtained by counts of deer pellet …

Evaluation Of Giant Canada Goose Restoration In Western South Dakota, Dennis L. Lengkeek

Electronic Theses and Dissertations

A study of giant Canada goose (Branta Canadensis maxima) restoration in western South Dakota was conducted during 1970 and 1971. Nesting, production and mortality, homing, and pioneering were evaluated both years. Nesting began April 4 in 1970 and extended for 73 days, but the peak of nesting occurred from April 29 to May 5. In 1971, nesting began April 1 and continued for 69 days, with the peak occurring April 8-14. The peak of hatching occurred June 6-12 in 1970 and May 8-14 during 1971. Small stockponds were utilized for nesting both years. Islands were preferred nesting sites. Peninsulas and …

Nuclear Charge Distribution Of Tm¹⁶⁹, Eugene Clark Deci

Graduate Dissertations and Theses

The distribution of electrical charge in the nucleus of Tm¹⁶⁹ was determined by measurement of the energies of the X rays of muonic atoms of Tm¹⁶⁹.

The values of the energies of the K X rays and the L X rays were calculated from a model assuming an anisotropic Fermi distribution of charge, and compared to the treasured values. The assumed distribution is a function of three parameters; a half radius, a surface thickness, and a measure of the anisotropy.

The values of the parameters were varied to find the values that gave the best agreement with …

The Weakly Coupled Polaron, Kou-Ying Yang Moravan

Graduate Dissertations and Theses

The Green's Function technique has been used to investigate the properties of weakly coupled longitudinal optical polarons. By taking into consideration the contribution of the multi-phonon and the phonon-cross-exchange diagrams in the self-energy, a vertex correction has been made to the lowest order diagram. The real part and the imaginary part of the self-energy are obtained. The dispersion relationship obtained by this approximation gives the ground state energy which is lower than the upper bound obtained from the variational method. Also, the spectral weight function for several momentum values has been calculated. It shows that the quasi-particle description is good …

Nuclear Charge Distribution Of ¹⁸¹Ta, David Edward Mcloughlin

Graduate Dissertations and Theses

The energies of the x rays emitted by the muonic atom of ¹⁸¹Ta were measured by a Ge(Li) solid state detector. From the clustering of these gamma rays it was possible to identify the transitions of the muonic atom which produced them. When a form is chosen for the nuclear charge distribution, a theoretical spectrum can be calculated…The parameters ��, c, and t can then be chosen to make the calculated spectrum coincide for the 3D-2P, and 2P-1S transitions with the observed spectrum.

The first part of the calculation was performed in the following way. The monopole part of …

Optimum Age, Temperature, And Salinity For Estuarine Stocking Of Juvenile Striped Bass, Morone Saxatilis, Walter Steven Otwell

Dissertations, Theses, and Masters Projects

A 3n factorial design to evaluate the effects of an abrupt introduction of striped bass, Morone saxatilis from a closed-system rearing facility into a variety of experimental temperature and salinity combinations has demonstrated a considerable hardiness of juvenile fish. Striped bass less than two months old had over 80.0%, survival during seven days subsequent to acute introduction from an average ambient condition of 21.0 ± 3 C at 0.20 to 4.8% into temperatures of 18 C and 24 C and salinities of 4.0% and 12.0%. Relative growth in these treatments was significantly greater than in the 12 C treatment at …

Biology Of The Rock Crab, Cancer Irroratus Say, In Coastal Waters Of Virginia, Lewis Roller Shotton

Dissertations, Theses, and Masters Projects

The commercial seabass notting fishery and the trawl fishery in the Blackfish Bank area east of the entrance to Chincoteague Bay were used to study the biology of the rock crab, Cancer irroratus Say. Highest relative abundance of rock crabs occured in February, March, and April when coldest inshore (<30m) bottom water temperatures occurred. Relative abundance during all other months was extremely low. The apparent seasonal change in relative abundance may be due to an inshore-offshore seasonal migration of mature crabs following the seasonal inshore-offshore shift of colder bottom water. Male rock crabs grow to a significantly larger size than females. The carapace width range of males captured in the potting fishery was 66 to 141 mm; and 25 to 106 mm for females. In the trawl fishery the width range for males was 20 to 137 mm; and 22 to 102 mm for females. In both pot and trawl catches the male to female ratio was biased in favor of males. Males comprised 92% of the pot catch and 84% of all crabs captured by trawl. From August through December all crabs were in the hard shell intermolt stage. Small percentages of soft crabs occurred from January through June. Papershell crabs predominated in February, March and April. It is probable that most crabs molted in January and the process of exoskeleton hardening took several months. Ovigerous females were captured in seabass pots in April and June and in trawls from February through April. All ovigerous crabs were in hard shell condition. Gondal inspection of males and the presence of eggs on females indicated that rock crabs mature at a relatively small size (30 mm carapace width). Female rock crabs have a deeper body and wider abdomen than equivalent width males. Abdomen width grows more rapidly for females after the onset of sexual maturity than before. Mature females have a longer carapace than equivalent width males. Male and female regressions of chela length on carapace width could not be compared statistically but plots of the equations suggest no sexual difference. This dissertation is from the Joint Program Degree from the College of William & Mary and University of Virginia and awarded by the University of Virginia.

Growth Rate And Nesting Aspects For The Glossy Ibis In Virginia, 1972, John William Williams

Dissertations, Theses, and Masters Projects

No abstract provided.

A Kinetic Examination Of 1,3-Di-T-Butyl-3-Methylbromoallene Solvolysis, Dwight Ellen Foster Ellis

Dissertations, Theses, and Masters Projects

No abstract provided.

Salt Water Plasma Model Of The Venus Atmosphere, Eueng-Nan Yeh

Dissertations, Theses, and Masters Projects

No abstract provided.

Model Legislation For The Administration Of Subaqueous Hard Mineral Resources Within Virginia Waters, William Jeffery Wardrop

Dissertations, Theses, and Masters Projects

No abstract provided.

Retention And Escapement Characteristics Of Pound Nets As A Function Of Pound-Head Mesh Size, Henry Louis Meyer

Dissertations, Theses, and Masters Projects

No abstract provided.

Absolute Differential Elastic And Inelastic Cross Sections In 25-140 Kev He⁺ + He Collisions, Victor Pol

Doctoral Dissertations

"The UMR heavy-ion energy-loss spectrometer has been modified to study the angular dependence of elastic and inelastic scattering for 25-140 keV He⁺ incident on He. The data were obtained as energy-loss spectra at angles from 0 to 7.3 x 10^-3 rad (c.m.) with energy-loss resolution of 0.6 to 1.0 eV and angular resolution of 1.2 x 10^-3 to 2.4 x 10^-3 rad (c.m.). From the spectra we have calculated average differential cross sections for elastic scattering, direct excitation of the individual He(n=2) states and direct excitation of the He⁺(n=2) states. By integrating the differential …

Anionic Polymerization Of A Series Of 5-Membered Cyclocarbosiloxanes, Balaraman Suryanarayanan

Doctoral Dissertations

"A study has been made on the anionic polymerization of a series of 5-membered cyclocarbosiloxanes with methyl and/or phenyl substituents. The polymerization was initiated by lithium n-butyldiphenylsilanolate in the presence of tetrahydrofuran. Six 5-membered cyclocarbosiloxanes (2,2,5,5-tetramethyl-1-oxa-2,5-disilacyclopentane; 2,2,5- trimethyl-5-phenyl-1-oxa-2,5-disilacyclopentane; 2,5-dimethyl-2,5-diphenyl- 1-oxa-2,5-disilacyclopentane; 2,2-dimethyl-5 ·,5-diphenyl-1-oxa- 2,5-disilacyclopentane; 2-methyl-2,5,5-triphenyl-1-oxa-2,5-disilacyclopentane; 2,2,5,5-tetraphenyl-1-oxa-2,5-disilacyclopentane) were synthesized. Since the chemical shifts of the protons of the cyclic monomers and the polymers formed were different, the rate of polymerization of the cyclic monomers was measured utilizing an NMR spectrometer. The effects of tetrahydrofuran concentration, initiator concentration and water concentration on the rate of polymer formation and on the molecular weight of …

Petrography, Diagenesis And Environment Of Deposition Of The Gasconade Formation, Lower Ordovician, Southern Missouri, Abd El-Aziz El-Hady A. Borahay

Doctoral Dissertations

"The Gasconade Formation (Lower Ordovician) has been studied in the surface and subsurface in the Ozarks of Missouri and northeastern Oklahoma. The formation is mostly dolomite with a sandstone member at the base (Gunter) and frequent occurrences of chert bodies of different shapes particularly in the middle part.

The dolomite crystals in the lower and upper parts are subhedral to euhedral of equicrystalline to two-size fabric and range in size from 300-600 microns, and subhedral to anhedral of variable fabric and smaller size in the middle part. A sequence of cloudy and clear areas, named zoning, characterizes the euhedral crystals. …

Approaches To The Synthesis Of Azabullvalene, Thomas Rudolph Steinheimer

Doctoral Dissertations

"Three approaches to the synthesis of the heretofore unknown azabullvalene, the pi electron equivalent heterocyclic congener of bullvalene itself, are described. Two of the schemes are based upon the assumption that the most convenient method for the introduction of the nitrogen atom is via thermal rearrangement of the appropriate azide.

The first involved the generation of the homobarrelene carbon skeleton and sub sequent decomposition of its azide. This compound arises formally as the product of the Diels-Alder addition of acetylene to the bicyclic valence isomer of tropyl azide (cyclohepta-1, 3, 5- trienyl-7-azide). In order to achieve this goal, Diels-Alder additions …

Petrography, Chemical Composition, And Stratigraphic Setting Of The Coals Of North-Central Missouri, William Keith Wedge

Doctoral Dissertations

"Under a grant from the National Air Pollution Control Administration, the Missouri Geological Survey undertook a core drilling program to learn more about the coals in north-central Missouri. The stratigraphic setting and chemical and petrographic characteristics of 43 complete samples of coal recovered from 13 diamond drill holes in the exploration program in north-central Missouri are major contributions of this study. These samples represent twelve different coal beds of the Atokan and Desmoinesian Series of the Pennsylvanian System of Missouri and range in thickness from 9.6 to 44.4 inches. They have an average thickness of 20.4 inches and a combined …