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Articles 2851 - 2880 of 2977
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A Study Of Far Infrared Grid Filters, Harold Victor Romero
A Study Of Far Infrared Grid Filters, Harold Victor Romero
Doctoral Dissertations
"The diffraction theory for the transmission of electromagnetic fields through a grid in a dielectric is derived and experimentally checked in the visible wavelength region. In the far infrared, an approximate mathematical representation is found to describe the grids in dielectrics. The empirical equations in the far infrared are combined with the electrical circuit-transmission line analog for inductive grids. Detailed structure of the transmittance versus wave number curves are presented. Then the theory of multielement grid filters is derived and compared with experiment. The properties of the filters can be predicted from a knowledge of the characteristics of the individual …
Absolute Excitation Cross Sections Of He⁺ In 20-100 Kev He⁺-He Collisions Using Energy-Loss Spectrometry, Donald Roy Schoonover
Absolute Excitation Cross Sections Of He⁺ In 20-100 Kev He⁺-He Collisions Using Energy-Loss Spectrometry, Donald Roy Schoonover
Doctoral Dissertations
"Application of positive-ion energy-loss spectrometry has been extended to include experimental determination of absolute excitation cross sections of ground state helium ions. Helium ion-atom collisions were studied for impact energies ranging between 20-100 keV, in 10 keV intervals. The data were taken with an apparatus resolution between 0.6-o.8 eV FWHM. Cross sections for transitions from ground state to the second and third principal quantum levels of the ion plotted as a function of impact energy were still rapidly increasing at 100 keV. The cross sections at this energy were 1.64(± 0.28) x 10⁻¹⁸cm² for He⁺(l²s1/2) -> He⁺(n = …
An Investigation Of The Stiffness Of Shafts With Integral Disks, Richard King Riley
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 …
Completeness And Related Topics In A Quasi-Uniform Space, John Warnock Carlson
Completeness And Related Topics In A Quasi-Uniform Space, John Warnock Carlson
Doctoral Dissertations
"Completions and a strong completion of a quasi-uniform space are constructed and examined. It is shown that the trivial completion of a T₀ space is T₀ . Examples are given to show that a T₁ space need not have a T₁ strong completion and a T₂ space need not have a T₂ completion. The nontrivial completion constructed is shown to be T₁ if the space is T₁ and the quasi-uniform structure is the Pervin structure. It is shown that a space can be uniformizable and admit a strongly complete quasi-uniform structure and not admit a complete uniform structure. Several counter-examples …
Development And Application Of Cartesian Tensor Mathematics For Kinematic Analysis Of Spatial Mechanisms, Robert Myrl Crane
Development And Application Of Cartesian Tensor Mathematics For Kinematic Analysis Of Spatial Mechanisms, Robert Myrl Crane
Doctoral Dissertations
"The complexity of spatial mechanisms in themselves and the absence of an attractive analytical tool for their study has left this field of engineering analysis largely unexplored. In recent years several analytic methods have emerged. One of the most attractive of these is the tensor method. Literature surveys reveal that the tensor method is largely unexploited in the U.S.A., with regard to spatial mechanisms as well as simpler kinematic problems. The purpose of this work is to develop tensor mathematics for application to the kinematic analysis of spatial mechanisms. Methods are developed for position solutions and the determination of velocities …
Discrimination Of Signal And Noise Events On Seismic Recordings By Linear Threshold Estimation Theory, David Nuse Peacock
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 …
Investigation Into The Monotonic Magnetostriction And Magnetic Breakdown In Cadmium, James Milo Carter
Investigation Into The Monotonic Magnetostriction And Magnetic Breakdown In Cadmium, James Milo Carter
Doctoral Dissertations
"Observations of the monotonic magnetostriction of cadmium at 4.2 K and in fields of 65 kilogauss have been made. The angular dependence of an extremal point (Hm) in the monotonic magnetostriction is found to follow inverse cosine behavior. The magnitude of Hm (27 kG) for fields parallel to [0001] is in fair agreement with the onset of γ1/3 from the breakdown of the trifoliate orbit, γ. The range of observation of hm coincides with the reported range of the trifoliate orbit. A "klink" in the monotonic magnetostriction is demonstrated. The "klink" field, Hk, …
Identification Of Decomposition Products Of Tropyl Azide And Interaction Of Tropylium Ion With Nucleophiles, James Joseph Ward
Identification Of Decomposition Products Of Tropyl Azide And Interaction Of Tropylium Ion With Nucleophiles, James Joseph Ward
Doctoral Dissertations
"An investigation of the structures of several of the products resulting from the decomposition of tropyl azide (I) and of the chemistry of related processes has been undertaken. Irradiation of samples of (I) in the vapor phase with low intensity UV G.E. Sun Lamps furnished a low melting white solid identified as tropyl troponimmonium azide (II). Earlier experiments of a similar nature reported to furnish (III) were not repeatable (Chem. Commun 276 (1967))...
Upon standing, solutions of (I) slowly formed troponimmonium azide (IV) in the cold (J. Chem. Soc. (D), 220 (1970)). The structures (II) and (IV) were confirmed by …
Mass Transfer From Spherical Gas Bubbles And Liquid Droplets Moving Through Power-Law Fluids In The Laminar Flow Regime, Cheng-Chun Huang
Mass Transfer From Spherical Gas Bubbles And Liquid Droplets Moving Through Power-Law Fluids In The Laminar Flow Regime, Cheng-Chun Huang
Doctoral Dissertations
"Continuous phase mass transfer coefficients are presented for internally circulating spheres of a Newtonian fluid traveling through a power-law type continuous phase in to so-called creeping-flow region. The Nakano and Tien stream functions allow the Sherwood number to be determined as a function of the Peclet number, power-law index, and a viscosity ratio parameter. The Hirose and Moo-Young relation is shown to be a limiting case of this solution. Mass transfer rates increase as the fluids become more pseudoplastic and/or the continuous phase consistency index increases, all other factors held constant"--Abstract, page ii.
Numerical Simulation Of Forward Combustion In A Radial System, Tommie C. Wilson
Numerical Simulation Of Forward Combustion In A Radial System, Tommie C. Wilson
Doctoral Dissertations
"A generalized mathematical model is described for the thermal recovery of oil in a radial system in which there are conductive heat losses to the surrounding formations, three phase fluid flow, conductive-convective heat transfer within the producing formation, combustion, and aqueous-phase changes considered. The mathematical form of the temperature equation requires that numerical solutions be obtained with a digital computer for which the numerical approximations of the partial differential equations are presented and the results discussed. The analysis is applied to field size simulations of a forward combustion project to permit direct field analyses of significant importance for accurate reproductions …
Realistic Impulsive P Wave Source In An Infinite Elastic Medium, Joseph Hugo Hemmann
Realistic Impulsive P Wave Source In An Infinite Elastic Medium, Joseph Hugo Hemmann
Doctoral Dissertations
"The generally assumed instantaneous impulsive pressure sources for an elastic P wave in an infinite medium lead to basic contradictions, a step function source yielding infinite displacements as the shear modulus goes to zero, and the total energy radiated by a delta function (or any derivative of the delta function) source being infinite. By noting that the character of the solution in the elastic region must match the acoustic case near the source, a realistic impulsive pressure source is postulated which has a finite time history. The elastic field produced by this source is then obtained in closed form. A …
Search Algorithms For The Simple Plant Location Problem, John Bruce Prater
Search Algorithms For The Simple Plant Location Problem, John Bruce Prater
Doctoral Dissertations
"Two algorithms are developed, one exact, one approximate, for finding solutions to the simple plant location problem. Theorems are proved which give sufficient conditions for the inclusion of a plant in the optimal solution. The exact algorithm which is developed is similar to the Branch and Bound method. The approximate technique consists of a directed search through the solution tree for the problem, followed by terminal iterations. The terminal iterations are justified by empirical results obtained from a preliminary version of the technique and a theorem which is proved. Statistics from the results of applying the algorithm to a large …
Structures And Relationships Of Some Perovskite-Type Compounds, Christian Michel
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 …
Substitution And Photolytic Rearrangements In Three-Member Ring Compounds, Joseph Terril Bohanon
Substitution And Photolytic Rearrangements In Three-Member Ring Compounds, Joseph Terril Bohanon
Doctoral Dissertations
"An investigation into the substitution and photolytic rearrangements of 1,2,3-triphenylcyclopropenes was conducted. Triphenylcyclopropenyl t̲-butyl ether was found to undergo alkyl group exchange with refluxing methanol, ethanol, or 2-propanol to yield the corresponding 1,2,3-triphenylcyclopropenyl alkyl ether when a trace impurity of a 1,2,3-triphenylcyclopropenium halide is present to catalyse the reaction. This forms hydrogen halide with solvent. Upon standing for long periods of time, the 1,2,3-triphenylcyclopropenyl ethers were observed to partially rearrange to new products. A sample of 1,2,3-triphenylcyclopropenyl methyl ether was subjected to photolysis in hexane and yielded 3-methoxy-1,2-diphenylindene, 2,3- diphenylindenone, tolane, benzoic acid, 1,2,3-triphenylpropen-1-one and a polymer. Samples of 1,2,3-triphenylcyclopropene, …
Temperature Variation In Distribution Of Relaxation Times In Aluminosilicate Glasses, David Wayne Moore
Temperature Variation In Distribution Of Relaxation Times In Aluminosilicate Glasses, David Wayne Moore
Doctoral Dissertations
"The distribution of relaxation times for the alkali peak in a Li₂ O·A1₂O₃ ·2.0SiO₂ glass and for the mixed alkali peak in a 0.5Li₂O·0.5Na₂O·A1₂O₃·2.OSiO₂ glass was studied using the internal friction technique. A lognormal distribution of relaxation times provided the best agreement with the experimental data. The ß parameter of the lognormal distribution function, which is related to the half-height peak width, varied with temperature, indicating that the distribution of relaxation times is dependent upon the activation energy and the activation entropy of the relaxation mechanism. The major contributor to the distribution of relaxation times is a wide distribution in …
The Electrochemical Oxidation Of 1-Pentyne On Platinum And Gold, Michael Jensen Danielson
The Electrochemical Oxidation Of 1-Pentyne On Platinum And Gold, Michael Jensen Danielson
Doctoral Dissertations
"The anodic oxidation of 1-pentyne was studied at 70°C on Pt and Au electrodes in solutions of H₂SO₄, K₂SO₄, K₂CO₃, and KOH. Pt was studied in a pH range of 0.35 - 12.7 and Au in a range of 10.9 - 12.7. Reaction rates were measured as a function of potential, pH, temperature, and 1-pentyne partial pressure. The coulombic efficiencies for the oxidation to CO₂ were 77 percent in 1 N H₂SO₄ and 69 percent in 1 N KOH on Pt and 43 percent in 1 N KOH on Au. The kinetic parameters on Pt were [partial derivative]V/[partial derivative]log i …
The Reaction Of N-Sulfinylamines With Diazoalkanes, Harry R. Musser
The Reaction Of N-Sulfinylamines With Diazoalkanes, Harry R. Musser
Doctoral Dissertations
"The photochemical decomposition of diphenyldiazomethane in the presence on N-sulfinylamines leads to ketimines. By-products include tetraphenylethylene, benzophenone, thiobenzophenone, and benzophenone azine. This reaction is the first example of carbene addition to a non-carbon containing multiple bond system. Evidence indicates that the carbene adds to the N=S bond of the N-sulfinylamine to give the corresponding thiaziridine-S-oxide which spontaneously decomposes to give ketimine and SO. In the dark N-sulfinylaniline catalyzes the decomposition of diazoalkanes to carbenes. This decomposition presumably takes place through a thiatriazole-1-oxide intermediate. The carbene then reacts either with N-sulfinylaniline to form ketimine, after loss of SO, or with diazoalkane …
The Surface Effects Of Alkali Halides In The Infrared, Vincent Joseph Llamas
The Surface Effects Of Alkali Halides In The Infrared, Vincent Joseph Llamas
Doctoral Dissertations
"The surface state extension of the shallow donor theory is reviewed. The surface state theory and its applications to F-centers of alkali halides is presented. Experimental infrared data show an absorption which seems to correspond with the ground state to first excited state transition. Surface state concentrations of F-centers as a function of depth into the crystal are given. The ratio of surface to bulk cross sections in KBr and experimental calculations of effective masses in various alkali halides are in excellent agreement with theory. The theoretical cross sections are derived from transition probabilities. However, lack of excited states, the …
Theory Of Shallow Donor Impurity Surface States, Vidal Emmanuel Godwin
Theory Of Shallow Donor Impurity Surface States, Vidal Emmanuel Godwin
Doctoral Dissertations
"A variational approach has been used to solve the effective-mass equation, when the impurity ion is located at a depth d from the surface of a semiconductor, where 0 < d < db and db represents the case when the impurity ion is in the bulk of the semiconductor. The ground state and the excited state having the largest electric dipole coupling to the ground state have been determined. We have plotted the energy dependence on the depth of the impurity ion from the surface of the semiconductor. The energy has also been calculated as a function of the orientation of the …
Simulation Of A Gas Storage Reservoir With Leakage By A Two-Dimensional Layered Mathematical Model, Steven William Ohnimus
Simulation Of A Gas Storage Reservoir With Leakage By A Two-Dimensional Layered Mathematical Model, Steven William Ohnimus
Doctoral Dissertations
"A generalized mathematical model was developed for two-dimensional compressible fluid flow accounting for the effects of relative permeability capillary pressure, and gravity drainage in addition to the reservoir properties of rock heterogenity and reservoir geometry. The generalized model developed was applied to an aquifer gas storage reservoir in which vertical leakage occurred from the main reservoir to two adjacent overlaying zones. The experimental results of Thomas, et al. were utilized in applying the model to gas storage injection/withdrawal periods yielding reasonable results for the three layers"--Abstract, page ii.
Wallman-Type Compactifications, Charles Morgan Biles
Wallman-Type Compactifications, Charles Morgan Biles
Doctoral Dissertations
No abstract provided.
Microwave Propagation Through Isotropic Inhomogeneous Photoconductive Media, Thomas Van Doren
Microwave Propagation Through Isotropic Inhomogeneous Photoconductive Media, Thomas Van Doren
Doctoral Dissertations
"The electromagnetic field equations for microwave propagation through a rectangular waveguide filled with a lossy, isotropic, linear, inhomogeneous material are derived in matrix form and solved numerically by computer. The theoretical effects of photo-induced conductivity and dielectric constant variations on microwave attenuation, phase shift, and voltage standing wave ratio are plotted for typical examples in the X-band frequency range. The theoretical calculations indicate that a two order-of-magnitude change in the conductivity can produce a 25 db change in the attenuation or a 100 degree change in the angle of the reflection coefficient. The theoretical predictions are verified qualitatively by experiments …
Statistical Inferences For The Cauchy Distribution Based On Maximum Likelihood Estimators, Gerald Nicholas Haas
Statistical Inferences For The Cauchy Distribution Based On Maximum Likelihood Estimators, Gerald Nicholas Haas
Doctoral Dissertations
"Various estimators of the location and scale parameters in the Cauchy distribution are investigated, and the superiority of the maximum likelihood estimators is established. Tables based on maximum likelihood estimators are presented for use in making statistical inferences for the Cauchy distribution. Those areas considered include confidence intervals, tests of hypothesis, power of the tests, and tolerance intervals. Both one- and two-sample problems are considered. Tables for testing the hypothesis of whether a sample came from a normal distribution or a Cauchy distribution are presented. The problems encountered in finding maximum likelihood estimators for the Cauchy parameters are discussed, and …
Studies In Atomic Fluorescence Flame Spectroscopy, Donald Romeo Demers
Studies In Atomic Fluorescence Flame Spectroscopy, Donald Romeo Demers
Doctoral Dissertations
No abstract provided.
Vapor Phase Clustering Model For Water, Richard W. Bolander
Vapor Phase Clustering Model For Water, Richard W. Bolander
Doctoral Dissertations
"Although nucleation phenomena are among the most widespread of all naturally occurring phenomena, even the simplest of nucleation processes, homogeneous nucleation, is poorly understood, particularly the homogeneous nucleation of liquid droplets from water vapor. Homogeneous nucleation involves only molecules of a single substance and does not include the complicating effects due to a substrate or piece of foreign matter. The semiphenomenological liquid drop theories developed nearly three decades ago differ in relatively minor details, with the crucial element of the theory being the derivation of the free energy of formation of the clusters. The clusters are viewed as well-defined incompressible …
A.C. Hall Effect Measurements On Very High Resistivity Materials Exhibiting Electrode Polarization, James Dale Boyd
A.C. Hall Effect Measurements On Very High Resistivity Materials Exhibiting Electrode Polarization, James Dale Boyd
Doctoral Dissertations
"A variable frequency, a.c. Hall effect measurement technique has been designed for mobility studies in very high resistivity (>10⁹ ohm·cm) materials exhibiting electrode space charge polarization effects. It incorporates a neutralized input capacitance preamplifier detector which reduces the total input shunting capacitance, including the sample interelectrode capacitances, to a very low, definable value (<0.1 pf) and thereby provides very high and well defined a.c. detector input impedances (4 x 10⁹ and 7 x 10⁹ ohms at 600 and 200 Hz, respectively). Lumped parameter equivalent circuits have been defined to approximate the electrical behavior of sample materials in the measurement configuration. These equivalent circuits, together with independent measurements of the detector input and sample impedances, allow one to correct the detected Hall voltage and obtain the true value from which mobility data may be derived. The validity of these circuits has been established by independent a.c. and d.c. measurements on photoconductive CdS (dark resistivity >10¹⁰ ohm·cm) which exhibited maximum differences of less than 4%. The existing literature has been critically reviewed and the measurement criteria established by this study have been applied to resolve differences in reported data and to suggest improvements in the resolution of previously employed experimental …0.1>
Calorimetry Of Room Temperature Deformed Copper, George Juri Filatovs
Calorimetry Of Room Temperature Deformed Copper, George Juri Filatovs
Doctoral Dissertations
"An adiabatic anisothermal differential calorimeter for the study of room temperature deformed 99.999% pure copper has been constructed. An annealed and a deformed specimen were heated at a constant rate in adiabatic surroundings and the differences in energy released between samples was obtained. The control circuits were automatic. Deformation was by elongation ranging from 12 to 40%, and the corresponding energy found was from 1.9 to 5.3 calories/gram-atom. No recovery energy was found. The results obtained generally agree with published results and, in particular, verify Gordon's isothermal annealing results. It is proposed that the criteria for the presence of recovery …
A Study Of The Energy Loss Spectra Induced By Impact Of 23-125 Kev Protons On Helium Atoms, Franklin Dean Schowengerdt
A Study Of The Energy Loss Spectra Induced By Impact Of 23-125 Kev Protons On Helium Atoms, Franklin Dean Schowengerdt
Doctoral Dissertations
"Results of a study of the inelastic energy loss spectra induced by the impact of protons on gaseous helium at energies of 25 to 125 keV are reported. The spectra were obtained by sending an accelerated beam of protons through a chamber containing the helium target gas, mass-analyzing the forward-scattered beam, then decelerating the beam to a low, well-defined energy for energy analysis and detection. The accelerating potential was varied to produce the spectra. An energy resolution of 2 eV was obtained. Apparent differential cross sections and absolute total cross sections were obtained from the spectra. Total cross sections for …
Dynamic Response Of Circular Plates To Transient And Harmonic Transverse Loads Including The Effect Of Transverse Shear And Rotary Inertia, Perakatte Joseph George
Dynamic Response Of Circular Plates To Transient And Harmonic Transverse Loads Including The Effect Of Transverse Shear And Rotary Inertia, Perakatte Joseph George
Doctoral Dissertations
"Using an improved theory of plate vibration suggested by R. D. Mindlin which takes into account the effects of transverse shear and rotary inertia, free and forced transverse vibrations of uniform circular plates are studied and the results compared with those obtained using the classical theory of plate vibration. The governing equations are developed in polar coordinates using the equations of elasticity. Frequency equations for axisymmetric and antisymmetric vibrations are derived for solid circular plates under different boundary conditions and for an annular plate rigidly mounted on a shaft. The response of plates to different types of rapidly applied axisymmetric …
A Five Parameter Study Of Spherical Transient Waves In A Generalized Voigt Model, Liang-Juan Tsay
A Five Parameter Study Of Spherical Transient Waves In A Generalized Voigt Model, Liang-Juan Tsay
Doctoral Dissertations
"Transient spherical waves in a generalized Voigt model were investigated in this study. Both Laplace and fourier transform solutions of the spherical wave equation for a generalized Voigt model were obtained by means of the correspondence principle. Laplace transform solutions were inverted numerically into the domain for the study of the characteristics of the wave forms, and Fourier transform solutions were utilized for the analysis of frequency dependency attenuation in the models. Generalized Voigt models A and B in which a dashpot is connected in series with spring and dashpot components were unable to represent a solid which would simulate …