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Magnetohydrodynamic Stability Of Laminar Flow In The Entrance Region Of A Parallel-Plate Channel, Thomas Eldon Eaton

Masters Theses

"The hydrodynamic stability of laminar flow of an electrically conducting fluid flowing in a parallel-plate channel with an applied transverse magnetic field is investigated. The linear perturbation theory of hydrodynamic stability along with the assumption of low magnetic Reynolds number is applied to the governing equations to derive the governing rnagnetohydrodynarnic stability equation. A finite difference scheme is employed to numerically solve the magnetohydrodynamic stability equation. Neutral stability characteristics of the flow in the entrance region are obtained and presented. The neutral stability characteristics of the fully developed Hartmann flow are also re-examined and compared with those of a previous …

Thermochemical Hydrogen-Deuterium Isotope Effects, Wayne C. Duer

Doctoral Dissertations

"The heats of solution at 25.0 ± 0. 1°C for each member of hydrogen-deuterium isotopic pairs (chloroform/chloroform-d, acetone/acetone-d₆, methanol/methanol-d₁, ethanol/ethanol-d₁, and water/heavy water) have been determined as a function of molality in a variety of solvents. The heats for most of the systems could be described as a linear function of average molality with an average deviation in fit of less than one per cent. Using these linear equations, heats of solution at infinite dilution were obtained by extrapolation to zero molality. The heats of solution at infinite dilution of the hydrogen containing compounds were subtracted from those of the …

An Sem Surface Study Of Nucleate Pool Boiling Heat Transfer To Saturated Liquid Nitrogen Reduced Pressures From 0.1 To 0.9, David Virgil Porchey

Doctoral Dissertations

"This study constituted an examination of both nucleate boiling and maximum heat flux characteristics of liquid nitrogen boiling from characterized surfaces. Several textures of gold plated copper surfaces were studied in addition to silver and silver oxide surfaces. Data were taken over a wide range of reduced pressures. All surfaces were examined using a Scanning Electron Microscope (SEM). Data and micrograph comparison revealed that both surface chemistry and surface roughness affect the nucleate boiling characteristics of liquid nitrogen. These effects are separated from each other showing that nucleate boiling is a function of both surface chemistry and topography. Surface roughness …

A Computer Simulation Of Mine Air Shaft Thermodynamics, Ambyo Sumopandhi Mangunwidjojo

Doctoral Dissertations

"Several earlier investigations have been conducted into various aspects of heat problems in underground mines. The application of general gas laws and thermodynamics in the approach of mine ventilation has been helpful in elucidating certain difficulties associated with the subject. By combining several of the techniques perfected by these researchers and applying Carrier's method of calculation for heat flow from exposed rock strata into a workable plan, a method was developed whereby it is possible to accurately and conveniently predict the quality of working environment at any point within a deep mine. The findings of this study may be of …

A Study Of The Effects Of Pressure-Induced Viscosity Changes On The Fluid Flow Characteristics In A Circular Tube, Robert Charles Weber

Masters Theses

"A method of determining the response of fluids under high pressure to quick-release into the atmosphere is presented in this report. The analytical efforts have been formulated into two parts, a closed-form solution and a numerical analysis. By assuming constant viscosity of the fluid a closed-form solution was obtained. The assumption of constant viscosity was found to be acceptable for the test fluids up to an initial pressure of approximately 10,000 psi. A numerical analysis became necessary for initial pressures over 10,000 psi, where the variable viscosity of the fluid had to be considered. The experimental work was conducted by …

Electric Field Strength Dependency Of The Rate Of Radiation Induced Degradation In Silicon Planar Devices, Cyrus Hoshang Irani

Masters Theses

"The investigation of electric field strength dependence of the rate of damage introduction, caused by gamma and neutron irradiations in matched is reported. Groups of devices (with varying biases applied to the emitter-base and collector-base junctions to allow study of the electric field strength dependence) were exposed to ionizing gamma radiation from a Co-60 source. Similar experiments were conducted to study the field strength dependence of the rate of space-charge volume damage introduction, caused by fast neutrons (E> l0keV, fission source). The experimental results indicate that the rate of surface degradation, as reflected by the increase of the normalized surface …

Statistical Estimate Of Positional Error Inherent In Very Low Frequency Radio Navigation (Range-Range), Jimmie D. Mcginnis

Masters Theses

"To determine the effectiveness of Very Low Frequency (VLF) navigation in certain areas of the world, it is necessary that a method be developed to estimate the positional error associated with VLF relative positioning techniques. This paper presents a method which consists of a least-mean-squared procedure to sum up the errors contributed by each station being monitored. Since phase jitter (i.e., phase fluctuation) is a random variable, a statistical approach is employed to produce a one Σ ellipse centered about the true position. In short, this method defines the size and orientation of an area called an error ellipse which …

Upper Cretaceous And Lower Cenozoic Foraminifera Of Three Oil Wells In Northwestern Iraq, Farouk Sunallah Al-Omari

Doctoral Dissertations

"Seventy-five samples of well cuttings and cores from the Iraq Petroleum Company Butmah Well No. 9, Ain Zalah Well No. 16 and Ain Zalah Well No. 17, in northwestern Iraq at approximately 36° 37' north latitude and 42° 41' east longitude, have been examined in detail. The lithologic descriptive term "marl" is replaced by calcareous shale or argillaceous limestone, and the term "globigerinal limestone" is not considered applicable. The foraminiferal fauna from the upper part of the Shiranish Formation prove to be of Maestrichtian age. The Mesozoic-Cenozoic boundary is recognized on the basis of "smaller foraminiferal" faunal assemblages; it is …

A Coordinate Oriented Algorithm For The Traveling Salesman Problem, Joseph Sidney Greene

Doctoral Dissertations

"The traveling salesman problem may be stated as follows: "A salesman is required to visit each of n given cities once and only once, starting from any city and returning to the original place of departure. What route should be chosen in order to minimize the total distance traveled?" A new algorithm is developed which gives a good approximation to the solution for a large number of cities using reasonable computer time and which will converge to the exact solution if allowed to continue. This algorithm is a branch and bound technique which utilizes the distance between cities in its …

An Investigation Of The Stiffness Of Shafts With Integral Disks, Richard King Riley

Doctoral Dissertations

"The results of an investigation of the effect of an integral disk on the torsional elastic stiffness of an axisymmetric shaft are presented. Various configurations of disk diameters and widths on a shaft of specified diameter were investigated, using a finite element method of calculation verified by experimentation. The finite element method is presented for the elastic solution of a general axisymmetric body under all possible axisymmetric load conditions. The axisymmetric body is idealized as an assemblage of triangular cross-sectioned torii representing both the normal and shear properties. The elastic stiffness is used to obtain the equilibrium equations of the …

Anodic Dissolution Of Zinc In Potassium Iodide-Potassium Iodate Solutions, Chi-Chiu Yao

Doctoral Dissertations

"The anodic dissolution of Zn was studied in KI-KIO₃ solutions at 25ºC. In I⁻ solutions, it was found that the apparent valence of Zn ions going into solution is approximately two. Smaller values are obtained in IO₃⁻ solutions, with the most pronounced changes occurring in the higher concentrations. An empirical equation is derived relating the apparent valence (or anode efficiency) to the current density and concentrations of IO₃⁻ and I⁻. An anodic dissolution mechanism is proposed"--Abstract, page 1.

Discrimination Of Signal And Noise Events On Seismic Recordings By Linear Threshold Estimation Theory, David Nuse Peacock

Doctoral Dissertations

"The object of this study is the investigation of a linear threshold element technique for identifying surface multiples on a single seismic trace. Traces of seismic events were generated which contained primaries, surface multiples, and various levels of Gaussian random noise. Since it was necessary to separate the events as much as possible, the traces were subjected to pulse-compression deconvolution processing prior to LTE analysis. Mean frequency, peak frequency, amplitude spectrum variance, periodicity, and polarity were employed as pattern parameters. A set of weights was found that would maximize the moment of inertia of the S line distribution of the …

Fault Detection In Asynchronous Sequential Circuits, Jeng-Chuan Kau

Masters Theses

"As the asynchronous sequential circuit has become more and more important to digital systems in recent years high reliability and simple maintenance of the circuit is stressed. This paper presents a fault-detection algorithm which will be applicable to most of the practical asynchronous sequential circuits. The asynchronous sequential circuit is treated from the combinatoric point of view. First the minimal set of states, both stable states and unstable states, sufficient to detect all possible faults of the circuit is found from the fault table. Then a test sequence is generated to go through these states. It is assumed that testing …

An Investigation Of Mining Effluent And Water Quality In The "New Lead Belt" Of Southeastern Missouri, Hong Wen Chen

Masters Theses

"A field and laboratory investigation was carried out to collect background data for stream water quality in the New Lead Belt of Southeastern Missouri. The parameters measured were temperature, hydrogen ion concentration, hardness, alkalinity, turbidity and fluorides. A prolific algal and microbial growth was found in Bee Fork Creek which receives the mining and milling wastewater effluent from the Fletcher Mine. The laboratory studies were conducted to examine the biological effects of the organic flotation reagents used in the mining operations. The studies included Gram staining of bacteria, antimicrobial effects of milling reagents, bacterial fermentation tests of sodium isopropyl xanthate …

A Study Of The Composite Action Of Light Gage Steel Deck And Concrete, Charles Sherman Bach Jr.

Masters Theses

"This thesis is on the investigation of corrugated light-gage steel sheets used as the tension reinforcement for concrete slabs. The steel sheets used had embossments placed at uniform intervals over the entire length of the sheets. The composite concrete and light-gage deck steel were tested to determine a method of design for this type of composite section from an economical, safe and practical standpoint. The investigation covered the flexural, shear and bond capacity of this type of composite section"--Abstract, page ii.

The Possible Correlation Of Carcinogenic Activity With Electronic Structure Of Benz(A)Anthracene, Patricia Joan Blair

Masters Theses

"The electronic structure of benz(a)anthracene based on the sigma and pi electrons was predicted by the modified intermediate neglect of differential overlap (MINDO) molecular orbital method and compared with the pi electronic structure determined by the Pople method. The crystalline molecular structure was used for both methods. The Pople calculation was also done on the aromatic molecular structure and a combination structure which assumed the bond lengths of the crystal structure and the bond angles of the aromatic structure. Chemical properties predicted by the MINDO and POPLE electronic structures were compared; the MINDO results provided the best agreement with experimental …

A Socio-Economic Traffic Demand Prediction Model Based On A Lumped System Approach, John Edward Thompson

Masters Theses

"The objective of this investigation was to devise a method for predicting transportation system demand based on socio-economic variables of certain physical areas. This pilot study was performed utilizing traffic flow, but minor mathematical alterations could change the transportation system to urban mass transit usage demand. An area of uniform socio-economic characteristics can be delineated and the socio-economic characteristics isolated. Each area will place a distinct demand on some existing transportation facility based on those characteristics. The physical demand can be approximated by a theoretical probability distribution. Once this internal flow generation has been approximated by the frequency distribution, it …

Interface Thermal Conductance With Metal Screens As Interstitial Material, William Edward Stewart Jr.

Masters Theses

"This thesis reports the results of an experimental investigation to determine the thermal conductance at the interface of metal specimens separated by wire mesh. Sets of metal specimens of copper, 2024-T4 aluminum, and 304 stainless steel were used. The specimens were cylindrical, axially aligned, and hydraulically loaded. All tests were conducted in an air environment. Pressure applied to the specimens ranged from 50 to 500 psig. Surface roughness of the interfaces varied from 5 to 20 micro inches. The wire mesh separators were of 304 stainless steel in 20, 30, 40, and 50 mesh. Results of the experiments show that: …

Dynamic Analysis Of A Torsional Vibration Actuator, Narayandas Trikamdas Ashar

Masters Theses

"The objective of this study is the evaluation of a mechanical system, which includes a Hooke's joint, as a possible torsional vibration actuator. The essential requirement of such a system is to produce a periodically varying angular motion superimposed upon a mean constant speed rotation. The basic kinematics of a Hooke's joint suggest that it could be used to generate the type of motion desired. The mechanical arrangement of a system incorporating a Hooke's joint is described and the governing differential equations are developed. These equations are simultaneous, differential equations of second order and are highly nonlinear. Values of typical …

The Smelting Of Lead Drosses, Humberto Adolfo Arzabe

Masters Theses

"The constitution of the matte and bullion obtained by the smelting of lead drosses coming from the cooling of lead blast furnace bullion was investigated by metallographic, chemical, electron-microprobe, and X-ray means. At smelting temperatures (1200°C to 1300°C) two liquid phases are in equilibrium. A liquid lead phase with low concentrations of copper and sulfur, and a lighter liquid matte phase containing a high concentration of copper and sulfur with some dissolved lead. On cooling to room temperature the matte precipitates cuprous sulfide, a eutectic mixture of cuprous sulfide and lead sulfide with a deficiency of sulfur, and metallic lead …

A Study Of The Design And Construction Of A Full Scale Aircraft Component Demonstration Fatigue Test, Stephen Andrew Wright

Masters Theses

"The objective of this project was to design and build a full scale demonstration fatigue test for a Piper Aztec stabilator. A general discussion of the construction is included in this report. The Fourier series method of the aerodynamic theory of spanwise loading was used to determine the load distribution. The results show a close relationship with data furnished by Piper Aircraft Corporation. Fatigue theory is discussed in order to provide background for fatigue testing. The test specimen, methods and procedures of testing, known loading methods and systems, safety, etc., are discussed. Federal requirements for regulating and testing of aircraft …

On-Line Digital Computer Decoding Of Radio Teletype, Julio Alberto Spiegel

Masters Theses

"Digital computer data processing is one of the newest and fastest growing technologies. The large amount of data that can be processed is practically beyond the limit of human possibilities when available time, cost and reliability of results are taken into consideration. The use of on-line digital computer data processing to decode Radio Teletype is investigated in this thesis. The first part of this thesis considers existing teletype systems and related systems, such as Pulse Code Modulation, pointing out the differences between synchronous and asynchronous codes. The most critical step in decoding Radio Teletype is synchronization, since Radio Teletype makes …

Computer Time-Sharing (T-S) "An Engineering Tool" For The Engineering Applications Of The Small Company, James Binford Summers

Masters Theses

"The objectives of this investigation were to illustrate the capabilities of the time-sharing (T-S) industry, identify the means by which the small sized company, with a need to solve engineering problems, can best be served through T-S, and to present T-S to these potential users. Investigation was made of distinctive T-S services to formulate a composite of the T-S industry. Examples of three distinctive T-S services were used within this composite to exemplify the variations of services within the industry. The methods a small company could use to utilize computer services were identified emphasizing T-S as the method best suited …

The Development And Analysis Of A System To Measure Transient Angular Velocity, David Lawrence Persson

Masters Theses

"A measuring system was built to provide a D. C. voltage which was proportional to the angular speed of a particular rotating shaft under question. The measuring system developed has a time constant of approximately .00365 seconds. The final measuring system was developed after trying various other means which proved unsatisfactory. The final device developed would be quite satisfactory in a wide variety of applications"--Abstract, page ii.

Integrating An Oscilloscope Into A General Purpose Automatic Test System, William Charles Bauer

Masters Theses

"The General Purpose Automatic Test System was developed for the Air Force as a system to automatically test and fault isolate an electronic unit under test. The Test System is a building block concept and this paper developed the hardware and programming software necessary to integrate an oscilloscope into the system. A Tektronix Type 564 oscilloscope with a Tektronix Type 3A5 Programmable Amplifier and a Tektronix Type 3B5 Programmable Time Base was used. A prototype of the digital and analog interface between the Test System and the Tektronix System was built and demonstrated. The Oscilloscope Building Block displays waveforms only …

Structures And Relationships Of Some Perovskite-Type Compounds, Christian Michel

Doctoral Dissertations

"A model for crystallographic transitions in perovskites is proposed. The model consists of regular octahedra sharing corners and topologically able to rotate without distortion around their three-fold axes. This model, with R3̄c symmetry (18e position) can be described in terms of a continuous rotation of angle, w, of octahedra from two ideal symmetry forms: the hexagonal close-packed and the cubic face-centered configurations. A parametric relation is derived between w and the rhombohedral cell angle, α, or the corresponding hexagonal axial ratio c/a . A wide range of atomic structures based on a framework of regular or slightly distorted octahedra sharing …

The Deformation Mechanisms In Sublimed Magnesium Under Cyclic Loading, Babu Narian Thakur

Doctoral Dissertations

"A detailed study of the deformation processes in sublimed magnesium under reverse bending fatigue in air at room temperature has been undertaken utilizing the light, scanning and transmission electron microscopy. The Principal deformation modes are the basal slip and {10Ī2} twinning. The proportion of twinning increases markedly with the increasing stress level and the number of cycles. The evidence for cross slip is seen on the basal slip bands. The extrusions are seen not only along the basal slip lines but also along the {10Ī2} twin boundaries. In the later stages of fatigue, the extrusions chip off producing a notch …

Influence Of Film Thickness On The Performance Of Solid Lubricants, Sunil Vishwanath Mahale

Masters Theses

"The object of this investigation was to determine the effect of lubricant film thickness on the coefficient of friction and on the wear life of solid lubricants. Bonded molybdenum disulphide and bonded graphite were the lubricants tested. Dow Corning's LFW-1 and Falex lubricant tester were the two machines used for testing these lubricants. The lubricants were sprayed on the specimen surface. Pretreatment, spraying and curlng were done according to standard or manufacturer's recommended procedures. During the entire research, the procedure for experimentation was followed according to ASTM No. 2625 on Falex and CRC recommendations on LFW-1 machine. It was found …

Voids In Neutron Irradiated Aluminum, Nicholas H. Packan

Doctoral Dissertations

"Void formation in high purity aluminum resulting from irradiation to fluences between 1.5 x 10¹⁹ and 1.6 x 10²² neutrons/cm² (E > 0 .1 MeV) at a temperature of 55 ± 5ºC was studied, primarily by means of transmission electron microscopy. In particular the effects of neutron fluence and flux were examined, as well as the possible influences of both preexisting and transmutation-produced impurities. A very low concentration of voids (about 10¹²/cm³) resulted from irradiation to 1.5 x 10¹⁹ neutrons/cm²; they averaged about 150 Å in diameter. Void concentrations and sizes increased with fluence, reaching values of 6 x 10¹⁴ voids/cm³ …

Higher Space Mode Analysis Of A Large Cylindrical Pulsed H₂O System, Harold David Hollis

Doctoral Dissertations

"By utilizing a geometrically centered pulsed source internal to a large (B²_g) ≈ 0.002) cylindrical H₂O system, the neutron flux was measured as a function of position and time. A least square fit of the data yielded the fundamental and five higher decay constants and amplitudes of the thermal neutron flux. Symmetrical and enhanced neutron densities were obtained as a result of the internal source. Long waiting times were unnecessary and data acquisition was accelerated.

The decay constants were found to be independent of position, pulse width, counting time and rates, method of normalization, or waiting time. …