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Nutation Control During Precession Of A Spin-Stabilized Spacecraft, Richard James Donner

Masters Theses

"The effects of precession thrust pulses and energy dissipation upon nutation of a spin-stabilized spacecraft are studied. Methods for controlling nutation during a precession maneuver are proposed and examined. In particular, a precession modulation control law is developed which uses precession thrust pulses to control nutation. Digital simulations show that precession control with separate nutation control is the fastest precessing system; however, the precession modulation method is only fractionally slower while not requiring a separate nutation control system"--Abstract, page ii.

Interior Noise In Military Helicopters, Charles E. Perez Jr.

Masters Theses

"The Temporary Threshold Shift (TTS) or temporary hearing loss caused by excessive interior noise in military helicopters results in a critical degradation of the acoustically unprotected infantryman's ability to detect the existence or the approach of the enemy by hearing under combat conditions. The overall problem of noise reduction in helicopters consists of: (1) identifying the various noise sources, and (2) employing appropriate noise control techniques. Identification of the source is accomplished by the frequency correlation of 1/10-octave band analysis of the interior sound levels measured within the helicopter cabin with near-field sound generated by the sound sources. Reduction of …

A Study Of Rf Induction Heating And Float Zone Refining Of Silicon, John Allen Reynolds

Masters Theses

"Float zone refining using simultaneous RF induction heating and electromagnetic levitation has proven to be the best technique for producing high purity silicon for the semiconductor industry.

A study of the power requirements for floating molten zones, of load to source impedance matching, and of considerations for RF heating coil design was conducted to determine possible methods of improving the technique. It is shown that the power requirements are within reason, that impedance matching can be improved by varying network parameters, and that certain vital items must be assured in the design of different RF heating coils.

It is believed …

Ideal Filter Approximation And Synthesis, Patrick Shu Yau Ho

Masters Theses

"Several methods are currently used for approximating the ideal low pass filter. Generally, those approximations relate only to the amplitude or phase characteristic of the ideal filter. A class of filters has been proposed as approximating both the amplitude and phase characteristics of the ideal filter. The characteristics of the first ten members of the proposed class are considered in this paper. The results indicate a much improved approximation to the ideal filter has been achieved"--Abstract, page ii.

Design And Construction Of An Electronic Pressure Altimeter For An Atmospheric Data Acquisition System, Larry Wayne Berkbigler

Masters Theses

"This thesis describes the design, construction, and application of an altimeter which was developed as part of the data acquisition system of a small aircraft used to study atmospheric conditions. The altimeter provides a digital readout and interfaces with analog and digital recorders. It can also provide an audio indication when a predetermined altitude is reached. The altimeter is powered by 12 volts dc, has resolution to 10 feet, and a maximum altitude of 15,000 feet. Its maximum theoretical error is ±78 feet ±0.77% of true altitude, which is an error of ±194 feet at 15,000 feet.

Since the unit …

Numerical Calculation Of The Currents In Bent Wire Antennas, Min Ho Kang

Masters Theses

"The current distribution for bent dipole antennas is numerically calculated by using a digital computer. A delta-gap at the center is assumed for the drive. Several different bend-angles are considered including the cases of the straight wire and the inverted-L. The total length of the wire considered is λ/2 while the ratio of the bent portion over the vertical portion is varied. The method of solution is based on Mei's integral equation and the method of moments. The use of Mei's integral equation eliminates the need for the application of the boundary condition at the point of bending. For …

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 …

Analysis Of Interferometric Holography In Temperature Measurement, Allan James Reifel

Masters Theses

"An experimental investigation was conducted to evaluate the accuracy and sensitivity of a laser holographic interferometer. Interference fringe patterns of a free convection boundary layer on the surface of a vertical test plate were produced. The plate was heated and designed to produce a linear temperature distribution along its surface.

A thermocouple probe was used to map the temperatures in the boundary layer and these values were compared to temperatures obtained from fringe patterns. Data photographs of the holograms were used in the analysis. The number of fringes obtained were compared to predictions of the Gladstone-Dale Law.

High quality fringe …

An Experiment To Determine The Coupled Unidirectional Effect Of Wind And Waves On Surface Drift, Rameshchandra C. Shah

Masters Theses

"An experiment was conducted to study the coupled parallel and unidirectional effect of wind and waves on surface drift velocity of oil lenses and flexible plastic floats. The experiment was also conducted to study the effect of float width, wave length and air turbulence on the drift velocity of the surface floats. Experiments were also conducted to determine the air flow characteristics of the wind tunnel test section.

Experimental results are presented for a free stream wind velocity from zero to 700 cm/sec; the wave steepness ranged from zero to 0. 069, which is near the maximum steepness for stable …

Sintering And Microstructure Control Of A Ferrimagnetic Mn-Zn Ferrite Spinel, Joel Keith Michel

Masters Theses

"The effect of minor additions of CaO dopant to a manganese zinc ferrite – Zn_.25Mn_.75 Fe_2.17 O_4.0 - on its grain growth and densification kinetics in air at 1250°C., 1300°C., and 1350°C. was studied. Grain growth was controlled over a range of dopant levels. At a sintering temperature of 1350°C. and time of six hours a ferrite with the smallest dopant addition was sintered to the highest density - 98% of theoretical. Under the same sintering conditions ferrites with higher dopant levels also sintered with normal growth but sintered to lower densities.

Due to discontinuous …

Thermal Radiative Properties Of A Semi-Infinite Absorbing-Emitting And Isotropically Scattering Medium, Tung-Ting Lam

Masters Theses

"The development and the approximate solution to the transport equation for a semi-infinite, absorbing, and isotropically scattering medium with a refractive index other than unity is presented. The general boundary condition of diffuse and collimated incidence at the interface with emission from the medium was considered by superimposing the individual effects. In each case the apparent properties, directional and hemispherical emittance, reflectance and transmittance, were evaluated as a function of the scattering albedo and the refractive index.

An exponential kernel substitution was developed and used to obtain the approximate solution. The method was evaluated by a comparison with existing but …

Optimal Synthesis Of Active Distributed Rc Low-Pass Filters, Robert Iman Egbert

Masters Theses

"Although synthesis procedures for active distributed RC networks are well developed, the approximation problem is largely unsolved. Previously proposed solutions have several disadvantages. A better solution to the approximation problem is obtained by developing an error expression involving the difference between the ideal specification and the exact realization, then minimizing this error by numerical techniques. The method is illustrated by designing a set of active distributed RC low-pass filters"--Abstract, page ii.

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 …

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 …

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 …

Attitude Scaling As A Public Involvement Tool In The Lower Mississippi River Region Comprehensive Study, William A. Lee

Masters Theses

"The planner is under considerable pressure to involve the public in water resource planning. The public, however, often lacks sufficient knowledge to offer useful comments or suggestions. The use of a Likert Type Attitude Scale in the public involvement effort of the Lower Mississippi Region Comprehensive Study demonstrates the usefulness of attitude scaling techniques in obtaining public input to the planning process. The measurement of an individual's attitude, or his thoughts, feelings and disposition to act toward some aspect of his environment with some degree of consistency, gives an indication of the goals and objectives toward which a plan acceptable …

Relative Volatility In The System 1-Butene - N-Butane, Steven Lewis Walker

Masters Theses

"An apparatus suitable for the rapid collection of P-x data at constant T is described. Isothermal P-x data at 40, 70, 100, 130, and 160 degrees Fahrenheit at the extremes of the composition range for the 1-butene - n-butane system are presented as a demonstration of the suitability of the device for its intended purpose. Limiting values of the relative volatility for the binary are presented. The relative volatilities were calculated using limiting forms of the general coexistence equation which are given in the literature. Several recommendations are given for improvements of the equipment and experimental technique"--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 …

Power, Divergence, And Stability Factors Affecting The Use Of A Krypton Laser As A Multispectral Illumination Source, David Perry Owsley

Masters Theses

"Specific performance characteristics of a krypton laser were measured. Evaluation criteria were dictated by the proposed use of the laser as a multi-wavelength illumination source. The laser output power, spectral power distribution, and output stability were measured as a function of wavelength and transverse mode order, to determine optimal operation characteristics. Data are presented defining the compromise between laser output power and beam divergence when the laser is operated multi-wavelength, and in several low-order transverse modes. There is an advantage of increased output power when the laser is operated in transverse modes higher in order than TEM₀₀, but …

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.

A Thin Film Evaporator Rate Controller, Daniel Robert Kasterlein

Masters Theses

"A circuit is described which is used to control the evaporation rate of material from a resistance heated boat or electron beam evaporator. The rate controller is used in conjunction with a quartz crystal thickness monitor in a vacuum evaporator"--Abstract, page ii.

The Effect Of Porosity On Strength Degradation In Thermally Shocked Alumina, Russell David Smith

Masters Theses

"Strength degradation and crack propagation in Al₂O₃ are shown to depend on the initial strength and porosity of the material. Specimens were fabricated containing between 0 and 5% induced cylindrical, two dimensional, and spherical porosity. The strengths of the various porosity samples decreased discontinuously at a critical quenching temperature. No difference was observed in the critical temperature for the various aluminas; initial strength decrease occurred between 165°C and 175°C temperature differential. The strength retained after thermal shock decreased with increasing initial strength. The degree of damage sustained upon shocking was also characterized by crack density and crack …

Nucleate Pool Boiling Of Refrigerant-Oil Mixtures From Tubes, R. L. Dougherty

Masters Theses

"This experimental investigation was conducted to provide design heat transfer data for applications involving the nucleate pool boiling of Refrigerants 11 and 113 from the external surfaces of tubes. Tests were conducted with 0.625-in. o.d. and 1.125-in. o.d. commercial copper tubing; at 1 and 2 atmospheres pressure; and with refrigerant-oil compositions from 0 to 10 percent oil by weight. Results show that each of these parameters can affect the heat transfer coefficient"--Abstract, page ii.

Managerial Performance Appraisal, Benildus Wai-Young Lau

Masters Theses

"Questionnaire surveys were sent out to two hundred medium-sized companies in industry. The study is an attempt to find the main cause for the unsatisfactory results in most appraisal programs and to make recommendations concerning the implementation of an effective performance appraisal program. Human factors play an utmost important role in the success of the entire appraisal program. An atmosphere of mutual understanding and trust should be established between the well trained supervisor and his subordinate so that the rapport between them can be brought to the highest possible level. Performance appraisal should be considered as an integral part of …

The Linear New City -- A Pattern For New Cities Based On Efficiency Of Transportation, Public Services, And Land Use, Elbridge Wesley Bartley Iii

Masters Theses

"The linear new city is defined as a city consisting of some arrangement of relatively narrow, high-density strips, served by various mass transportation systems. Such a new city would be ideally suited to the implementation of the latest technology. The concentration of development along the transportation route would allow certain economies in the supply of utilities and services, as well as insuring that open space would be readily available around and throughout the city. The provisions for transportation, housing, and governmental control should combine to produce a better quality of life for the inhabitants of the linear new city"--Abstract, page …

The Simulation Of A Production Control System, Steven Craig Weis

Masters Theses

"In an attempt to simulate a production system a typical company was assumed, and mathematical models of its functions were structured to form a total model. This model was programmed into an IBM 360/50 computer. A program which included seasonal trends and random requirements for various departments was designed that would evaluate all the available alternatives and output the two best production schedules such that operating costs would be minimized and the company labor force would remain nearly constant. These schedules detail the manpower requirements by week, department, line, job and shift.

To accommodate the seasonal trends, various forms of …

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 …

A Study Of The Ability Of Water Treatment To Remove Trace Organics, Daniel Lee Oliver

Masters Theses

"The purpose of this investigation was to study the ability of water treatment processes, especially coagulation and chlorination, to remove trace organic materials from raw river water. Trace organic concentrations were determined using the Organics-Carbon Adsorbable (O-CA) technique, a miniaturized Carbon Adsorption Method (CAM).

Missouri River raw and treated water, obtained on 3 different dates at the Jefferson City, MO, water treatment plant, was used. The effect of various treatment steps, including settling, softening with lime, coagulating with copperas or alum over a range of doses, and chlorinating at the dose necessary to give a free residual of 2 mg/1 …

Design Of An Analog-Temperature Control System For An Expansion Cloud Chamber, Andrew C. Tebelak

Masters Theses

"This thesis describes the design, construction, and application of an analog control system for the temperature control of an expansion cloud chamber. During the expansion, the sample gas and the chamber walls are cooled at the same rate so as to maintain adiabaticity. The control system measures the wall temperature with transistor temperature sensors, calculates the gas temperature from the gas pressure using the adiabatic gas law, and generates a control signal proportional to their difference. The control precision is sufficient to allow the chamber to be used in the study of atmospheric phenomena.

The chamber is a ten-sided right …

Calculation Of Gamma-Ray Albedo Using The Monte Carlo Method, Ezatholah Aslani-Amoli

Masters Theses

"Gamma-ray number, energy and dose albedo are calculated with the Monte Carlo technique. A plane monoenergetic beam was considered at normal incidence upon single material shields at initial gamma energy up to 10 MeV. Aluminum, iron and lead are used as shield material. The contribution of secondary photons which are produced as a result of various photon interactions in the shield are taken into account. These secondary photons are annihilation gammas, X rays and bremsstrahlung gammas. In certain cases, they constitute a considerable fraction of the reflected radiation.

Annihilation gammas predominate in the reflected radiation for all energies above 1.02 …