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Articles 2791 - 2820 of 2977
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A Monte Carlo Calculation Of Neutron Reflection From Various Curved Surfaces, Charles Jack Kalter
A Monte Carlo Calculation Of Neutron Reflection From Various Curved Surfaces, Charles Jack Kalter
Doctoral Dissertations
"Plane parallel neutron beams normally incident upon the curved surface of a solid reflector are studied with the Monte Carlo method. The geometries studied are cylindrical, parabolic, and hemispherical. It is shown that when the curved surface is cylindrical, a small "focusing effect" occurs in the reflected neutron beam. Parabolic and hemispherical surfaces do not show "focusing". A study of the factors which determine the spatial dependence of the reflected flux shows that the probability of emergence of a neutron, traveling a fixed distance from a point inside the reflector, depends upon the curvature of the surface. It is only …
The Calculation Of Vander Waals' Constant By The Extended Hartree-Fock Wave Function, Jwe-Son Kuo
The Calculation Of Vander Waals' Constant By The Extended Hartree-Fock Wave Function, Jwe-Son Kuo
Doctoral Dissertations
No abstract provided.
Neometric Spaces, Stephen Aurom Kenton
The Diffraction Of Plane Sound Waves By A Perfectly Reflecting Quarter-Plane, Curtis Spaulding Morse
The Diffraction Of Plane Sound Waves By A Perfectly Reflecting Quarter-Plane, Curtis Spaulding Morse
Doctoral Dissertations
No abstract provided.
Geometry And Extension And Representation Theorems For Ordered Linear Spaces, Garfield Clair Schmidt
Geometry And Extension And Representation Theorems For Ordered Linear Spaces, Garfield Clair Schmidt
Doctoral Dissertations
No abstract provided.
On Normal Formations And Related Classes Of Groups, Stephen Allan Bacon
On Normal Formations And Related Classes Of Groups, Stephen Allan Bacon
Doctoral Dissertations
No abstract provided.
Rocket Measurements Of Field Aligned Currents And Energy Spectra Of Charged Particles In An Auroral Display, Lawrence Wah Choy
Rocket Measurements Of Field Aligned Currents And Energy Spectra Of Charged Particles In An Auroral Display, Lawrence Wah Choy
Doctoral Dissertations
No abstract provided.
Perception And Scientific Observation: A Challenge To The Assumption Of Objectivity, Raymond E. Rainville
Perception And Scientific Observation: A Challenge To The Assumption Of Objectivity, Raymond E. Rainville
Doctoral Dissertations
No abstract provided.
Modeling The Visual Pathway For Interactive Diagnosis Of Visual Fields, Chiam Geoffrey Goldbogen
Modeling The Visual Pathway For Interactive Diagnosis Of Visual Fields, Chiam Geoffrey Goldbogen
Doctoral Dissertations
"Visual fields are an important tool for the ophthalmologist in the detection, diagnosis, and monitoring of certain diseases and maladies of the visual pathway. The aim of the present research is to build a computer system which utilizes a learning machine to develop a mathematical model of the visual pathway. It is hoped that this system may be used in the field of ophthalmology as a teaching aid, or may assist in various aspects of diagnosis. Faults corresponding to blind or impaired areas of visual fields are extracted from medical records of a patient's condition. The structure of the model …
Characterizing Topologies By Classes Of Functions And Multifunctions, Alexander Hamlin Cramer
Characterizing Topologies By Classes Of Functions And Multifunctions, Alexander Hamlin Cramer
Doctoral Dissertations
"Topological spaces are characterized by the algebraic and topological structures of their classes of continuous selfmaps. The problem of determining the topology of a set given certain classes of multifunctions or relations is considered. The algebraic structure of the upper semicontinuous multifunctions is shown to determine the topology of T₁ spaces. A partial order for classes of topologies for the real numbers is defined and relationships between various classes are established"--Abstract, page ii.
Some Metal Complexes Of Dihydroxycyclobutenedione, Stewart Michael Condren
Some Metal Complexes Of Dihydroxycyclobutenedione, Stewart Michael Condren
Doctoral Dissertations
"This study involves an investigation of some of the physical and chemical properties of the trivalent metal squarate complexes of iron, vanadium, and indium in order to determine their structure. In this investigation studies were made of the infrared spectra, electronic spectra, x-ray diffraction powder photographs and diffractometer patterns, magnetic susceptibilities, and thermogravimetric patterns for the trihydrate, dihydrate, and anhydrous squarate complexes of vanadium(III) and iron (III) and the dihydrate squarate complex of indium(III). These studies suggest that the structures of the vanadium(III) and iron(III) squarate complexes are dimeric with hydroxyl bridges between the metal atoms. This is supported by …
Absolute Cross Sections For Excitation Of Neon By Impact Of 20-180 Kev H , H₂ And He Ions, George William York
Absolute Cross Sections For Excitation Of Neon By Impact Of 20-180 Kev H , H₂ And He Ions, George William York
Doctoral Dissertations
"The technique of heavy-ion energy-loss spectrometry has been used to measure excitation cross sections for the (2p⁵)3s and (2p⁵)3p electronic configurations of Neon. The incident particles used were H⁺ , H⁺₂ and He⁺ at impact energies from 20-180 keV. The results are compared with previous optical measurements of the emission cross sections of lines from these levels as excited by H⁺ and He⁺ impact. Agreement is not good, either in shape or in absolute magnitude for excitation of the (2p⁵)3s configuration. However, agreement is surprisingly good for excitation of the (2p⁵)3p configuration. A curve fitting technique has been applied to …
An Investigation Of Subsequent Yield Phenomena, Joseph George Hoeg
An Investigation Of Subsequent Yield Phenomena, Joseph George Hoeg
Doctoral Dissertations
"A method utilizing high pressure fluid environments is described whereby a three-dimensional subsequent yield surface was determined for 304 stainless steel. Cylindrical parent specimens of this material were prestrained in axial compression under fluid pressure and then small sub-specimens were sectioned from these parent specimens. Finite element techniques were used to optimize the parent specimen size so that a zone of uniform axial stress would result during the prestraining. Longitudinal strains in this zone were monitored during the prestraining and the sub-specimens were cut from this region in a manner that did not allow the machining to appreciably affect the …
Distribution Of Trace Elements In Olivines And Proxenes - An Experimental Study, Melvin Leroy Bird
Distribution Of Trace Elements In Olivines And Proxenes - An Experimental Study, Melvin Leroy Bird
Doctoral Dissertations
"Olivine, pyroxene,and spinel were crystallized in the ternary system anorthite-forsterite-silica to which trace amounts of the transition metal ions Cr³⁺, Fe²⁺, Mn²⁺, Co²⁺, Ni²⁺, and Cu²⁺ had been added. The resulting concentrations of the transition metal ions in the liquid and crystalline phases were determined using the electron microprobe. The results, given as free energies and partition functions, indicate the order of substitution of the dipositive ions in all crystals to be Ni²⁺, Co²⁺, Mn²⁺, Cu²⁺, and Fe²⁺ according to the predictions of crystal field theory. The ion Cr³⁺ substituted in greater or lesser quantities depending on the crystalline phase. …
On-Line Economic Optimization Of A Chemical Reactor, Jesse Daniel Bennett
On-Line Economic Optimization Of A Chemical Reactor, Jesse Daniel Bennett
Doctoral Dissertations
"An economic optimizing control system for a continuous flow stirred tank chemical reactor is designed, simulated, and installed on a pilot scale reactor. The control scheme utilizes a reaction and reactor model to predict on-line the economic optimum of a reactant concentration. In this manner the control system manipulates the reactant flow rate to maintain the optimum concentration during changes in reaction-reactor parameters with time. Typical parameter changes include the decay of reaction catalyst activity. The optimizing controller will function in conjunction with various operating policies including control to maintain a specified production rate"--Abstract, page ii.
Response Surface Study Of A Characteristic Chemical Plant, John Thomas Mason Iii
Response Surface Study Of A Characteristic Chemical Plant, John Thomas Mason Iii
Doctoral Dissertations
"Study of the return on investment response surface of a characteristic chemical plant indicates unimodality in the valid region, but the optimum design condition with this response surface is strongly affected by the correlation used for the investment. The method used for the design of this type of chemical plant incorporates the use of a simulation routine for preliminary estimates"--Abstract, page ii.
Some Statistical Inferences For The Bivariate Exponential Distribution, Bruce Mohr Bemis
Some Statistical Inferences For The Bivariate Exponential Distribution, Bruce Mohr Bemis
Doctoral Dissertations
"The bivariate exponential distribution is neither absolutely continuous nor discrete due to the property that there is a positive probability that the two random variables may be equal. Basic properties of the distribution are presented as well as methods of parameter estimation including maximum likelihood. The distribution is shown to satisfy the usual regularity conditions in spite of its possession of a singularity. The maximum likelihood estimates are asymptotically efficient. Two other methods of estimation are compared with the maximum likelihood method in terms of efficiency. Tests of the hypothesis that two random variables each have independent exponential distributions versus …
Special Subrings Of Real, Continuous Functions, Paul Marlin Harms
Special Subrings Of Real, Continuous Functions, Paul Marlin Harms
Doctoral Dissertations
"Some lattice-ordered subrings of C(X) containing C*(X) are examined where X is a completely regular space. Each realcompact spaceY between [v]x and ßx is associated with a lattice-ordered subring of C(X) which is isomorphic to C(Y) and contains C*(X). The cardinal number of (ßX - [v]X) is a lower bound for the cardinal number of these subrings. Every prime ideal in each of these subrings is comparable with the intersection of the subring and a maximal ideal in C(X). The structure space of maximal ideals is studied for special subrings in C(X) containing CK(X), the continuous functions of …
The Thermal Accommodation Coefficients Of Helium, Neon, And Argon On Surfaces, Gerald Lee Zweerink
The Thermal Accommodation Coefficients Of Helium, Neon, And Argon On Surfaces, Gerald Lee Zweerink
Doctoral Dissertations
"Measurements of the accommodation coefficients of helium, neon, and argon on an ice surface at 77ºK were accomplished; Measurements of the accommodation coefficients of helium and neon on a clean tungsten surface are also reported here; These data are compared with theoretical calculations of accommodation coefficients as well as with data from other experimental studies"--Abstract, pages iii-iv.
The Vibrational Modes Of Spheroidal Cavities In Elastic Solids, David Stewart
The Vibrational Modes Of Spheroidal Cavities In Elastic Solids, David Stewart
Doctoral Dissertations
"A general analysis of all possible cavity shapes is given with a discussion of the mathematical difficulties involved for the various cases. Special emphasis is given to cavity shapes describable in terms of the coordinate surfaces of coordinate systems separating the scalar wave equation. 112 such shapes are identified and discussed. Free boundary condition equations for spheres and spheroids are derived in complete generality in terms of potentials. The difference in the vibrations of a solid and those of a cavity of the same shape is discussed and made clear. The impossibility of deriving a frequency equation for uniform radial …
Trace Base Metals, Petrography, Rock Alteration Of The Productive Tres Hermanas Stock, Luna County, New Mexico, Peethambaram Doraibabu
Trace Base Metals, Petrography, Rock Alteration Of The Productive Tres Hermanas Stock, Luna County, New Mexico, Peethambaram Doraibabu
Doctoral Dissertations
"Zinc, lead and minor copper-bearing manto-type and vein- type deposits occur in Paleozoic sedimentary rocks adjoining the Tres Hermanas quartz monzonite stock, Luna County, New Mexico. In an attempt to prove or disprove a possible genetic relationship between these mineral deposits and the stock, 99 half-mile or closer orthogonal grid samples from the stock and 22 soil samples from a connecting alluvial area to the north were analysed by atomic absorption technique for trace contents of zinc, lead and copper. Thirty-two of the rock samples were selected on a wider grid and petrographically studied and modal analyses calculated. Argillic, sericitic …
Transient Hydraulic Simulation: Breached Earth Dams, D. L. Fread
Transient Hydraulic Simulation: Breached Earth Dams, D. L. Fread
Doctoral Dissertations
"A conceptual method to alleviate flood damages due to over-topping failures of small earthfill dams is the incorporation of a relatively thin erosion retarding layer within the dam. This paper investigates the reduction in the reservoir release due to the hypothetical erosion retarding layer. In addition, the paper provides a method for the determination of an optimal location of the layer so as to minimize the maximum possible reservoir release due to a gradually breached earth dam. The transient reservoir flow is simulated by a numerical model, based upon the solution of the one-dimensional St. Venant unsteady open-channel flow equations. …
X-Ray And Mössbauer Spectroscopy Studies Of The Silicon-Antimony And Bismuth-Antimony Alloys, James Ralph Teague
X-Ray And Mössbauer Spectroscopy Studies Of The Silicon-Antimony And Bismuth-Antimony Alloys, James Ralph Teague
Doctoral Dissertations
"X-ray and Mossbauer spectroscopy were used to investigate two antimony alloys, Bi-Sb and Si-Sb, showing semiconductorsemimetallic transitions or vice versa, depending on the antimony concentration in the host lattice. Resistivity and density measurements were found to be helpful in the analysis of the results. X-ray studies for dislocation-free antimony-doped silicon showed that the lattice constant of the alloy increased as the antimony concentration increased from 10¹⁸ to 10¹⁹ Sb atoms/cc. Rather good agreement was found between theoretical and experimental changes in lattice constant for dislocation-free silicon. Mössbauer studies showed that the isomer shift decreased linearly with increasing antimony concentration, which …
Low-Energy Electron Transport By The Method Of Discrete Ordinates, David E. Bartine
Low-Energy Electron Transport By The Method Of Discrete Ordinates, David E. Bartine
Doctoral Dissertations
"The one-dimensional discrete ordinates code ANISN has been adapted to simulate the transport of low-energy (on the order of a few MeV) electrons. Two different calculational techniques have been utilized for the treatment of electron-electron collisions that result in a small energy transfer. One method treats such collisions by a continuous slowing-down approximation, while the other method treats these collisions by the use of a very approximate cross section. Calculated results obtained with ANISN are compared with experimental data for the transmitted energy and angular distributions for 1-, 2.5-, 4-, and 8- MeV electrons normally incident on aluminum slabs of …
Theory Of Nucleation Of Water Properties Of Some Clathrate Like Cluster Structures, Mehdi Daee
Theory Of Nucleation Of Water Properties Of Some Clathrate Like Cluster Structures, Mehdi Daee
Doctoral Dissertations
"The tranquility of classical homogeneous nucleation theory has been disturbed by the introduction of statistical mechanical correction factors to a basically thermodynamic theory. These factors, which appear to be essential, destroy much of the agreement with experiment in the case of water vapor. A molecular model for the pre-nucleation water clusters is proposed with a view toward resolving some of these difficulties. As a first step, the Properties of a few specific cluster configurations have been examined. Clathrate-like structures containing 16 to 57 water molecules are discussed. The hydrogen bonds were treated as simple harmonic oscillators for the purpose of …
Use Of The Turbulence Kinetic Energy Equation In Analyzing Turbulent Near Wakes, James Edward Auiler
Use Of The Turbulence Kinetic Energy Equation In Analyzing Turbulent Near Wakes, James Edward Auiler
Doctoral Dissertations
"A general method is presented for analyzing turbulent flow fields in the near wake regions of two-dimensional and axisymmetric bodies. The governing partial differential equations of continuity, momentum and turbulence kinetic energy are expressed in elliptic form in terms of the dependent variables stream function, vorticity and turbulence kinetic energy. An iterative finite-difference technique is used to solve the governing equations simultaneously. Numerical solutions are obtained for the following physical problems: 1. Laminar near wake: Only stream function and vorticity are considered for laminar flow. Solutions are compared with available analytical results for uniform flow over a sphere. 2. Turbulent …
Homogeneous Nucleation Of Water Vapor In Inert Gas Atmospheres, Arthur Henry Biermann
Homogeneous Nucleation Of Water Vapor In Inert Gas Atmospheres, Arthur Henry Biermann
Doctoral Dissertations
"The homogeneous nucleation of water vapor in atmospheres of helium, neon, argon, krypton, and xenon was studied using an expansion type cloud chamber. A strong dependence of the nucleation rate on the particular inert carrier gas was observed. At present the only dependence upon the nature of the carrier gas included in classical nucleation theories is a small factor arising from kinetic considerations which is in the wrong direction to explain the observations. To explain the dependence of the rate on the nature of the carrier gas, a molecular cluster model is assumed allowing inert gas atoms to occupy the …
Surface Plasmon-Longitudinal Optical Phonon Contribution To The Reflectivity Of N-Type Insb, William Eugene Anderson
Surface Plasmon-Longitudinal Optical Phonon Contribution To The Reflectivity Of N-Type Insb, William Eugene Anderson
Doctoral Dissertations
"The reflectivity of n-type InSb has been measured in the far infrared. The doping of the samples was such that the free-carrier plasma frequency was near the longitudinal optical phonon frequency. The results suggest that samples with a sufficiently thick damage layer show effects due to surface plasmons. The results also indicate that the surface plasma excitations are coupled to the phonons. A simple model of this coupling is presented which agrees qualitatively with the observed reflectivity. A somewhat more rigorous theory of the coupling is also presented"--Abstract, page ii.
Synthesis, X-Ray Characterization, Structural And Magnetic Studies Of A New Class Of Iso-Structural Bimo₃ Compounds, Joseph Donato Bucci
Synthesis, X-Ray Characterization, Structural And Magnetic Studies Of A New Class Of Iso-Structural Bimo₃ Compounds, Joseph Donato Bucci
Doctoral Dissertations
"This dissertation consists of four sections. The first part is a temperature dependent X-ray study of the lattice parameters of BiFeo₃. The synthesis and subsequent X-ray characterization of BiCo₃, BiAlO₃, BiMnO₃ , BiScO₃, BiCo₁₋ₓFeₓO₃ , and BiAl₁₋ₓFeₓO₃ are reported in the second part. These compounds all crystallize in the body centered cubic (BCC) structure with a~10.2Å. Single crystal Precession and Weissenberg photographs confirmed the BCC structure. In part three, the results of the magnetic studies on BiCoO₃ and biAl.₉FE.₁ are presented. The magnetic data for BiCoO₃ are substantiated by X-ray thermal expansion studies. In the last part the compound BiCo.₉FE.₁O₃ …
Photoionization Of Photoexcited Cesium, Robert E. Hebner
Photoionization Of Photoexcited Cesium, Robert E. Hebner
Doctoral Dissertations
"A new method for obtaining the cross section for photoionization of photoexcited cesium is presented. The salient feature of this experiment is to use three crossed beams, i.e., two light beams intersecting a beam of cesium atoms. The cross section is determined by counting the ions produced by the two step process: Cs (6S) + h[upsilon]₁ --> Cs (6P) ; Cs (6P) + [upsilon]₂ --> Cs⁺ + e⁻ The relative cross section for the second step has been obtained from threshold (5060 Å) to 2500 Å. The excitation light source used in obtaining this cross section was a rf resonance …