8,322 Works

The Accurate Numerical Solution of Highly Oscillatory Ordinary Differential Equations

Robert Elmer, Jr Scheid
We consider systems of ordinary differential equations with rapidly oscillating solutions. Conventional numerical methods require an excessively small time step (Δt = 0(εh), where h is the step size necessary for the resolution of a smooth function of t and 1/ε measures the size of the large eigenvalues of the system's Jacobian). For the linear problem with well-separated large eigenvalues we introduce smooth transformations which lead to the separation of the time scales and computation...

The wing-body problem for linearized supersonic flow

George K. Morikawa
This work is concerned with one of the important problems remaining in the theory of linearized supersonic flow: the study of non-planar systems dealing with configurations which cannot be completely solved with the existing theory - in particular, the study of interaction or interference between fuselage and lifting or control surfaces in supersonic flow. In Sections 1.2 and 1.3 the non-planar problems are classified and the problem considered to be the fundamental wing body problem...

The geology of a portion of Humphrey's quadrangle

David Holcomb Scott
Two sedimentary formations are present in this area; the Modelo formation and the Mint Canyon formation. The latter sediments make up most of the rocks in this region while the former is confined to the southwestern one-fourth of the area. An angular unconformity separates the marine Modelo (Upper Miocene) from the non-marine Mint Canyon formation (Lower-Upper Miocene). The sediments are typical of those deposited under semi-arid conditions. Conglomerates, sandstones, and clays are abundant. There has...

Photoproduction of neutral pions in complex nuclei

Christian Albertus Engelbrecht
The photoproduction of neutral pions from complex nuclei is expressed in terms of the photoproduction from single nucleons by means of the direct interaction model and the impulse approximation. A summation over all final states of the nucleus is performed by means of a closure approximation. Within the framework of the independent particle model of the nucleus, the nuclear matrix elements are evaluated exactly for closed shell nuclei, the final results being expressed in terms...

Viscous effects in inception and development of cavitation on axi-symmetric bodies. Cavitation inception. A semi-empirical method to predict caviation separation on smooth bodies

Vijay Hanumappa Arakeri
The schlieren method was developed as a flow visualization technique for use in water tunnels. The process of cavitation development on two axi-symmetric bodies was studied using this approach and found to be greatly influenced by the presence of a previously unreported viscous laminar separation. On these bodies, cavitation inception was observed to take place within this separated region which occurs far downstream of the minimum pressure point. On one of these bodies, the incipient...

An investigation in the reduction of tabulated loads for bolted joints fabricated of green Douglas fir

Robert Blynn Harris
Because of restrictions and shortages of materials and labor caused by World War II, the lumber industry has been forced to place on the market a great deal of lumber that is in a green condition. Consequently designers and engineers have been required to make use of this material. Specifications currently being used for the design of bolted joints in wood structures require that the allowable loads as tabulated therein be reduced when the material...

Application of Finite Elastic Theory to the Deformation of Cylindrical Tubes

Jen-shih Lee
In Part I three types of symmetrical deformations of thin cylindrical rubber tubes are discussed. In the first type a rubber tube is deformed into another circular cylindrical tube of different length and diameter by simultaneous inflation and extension of the tube. This deformation is useful in determining the mechanical properties of tube-like material and it was found that Rivlin-Saunder form of strain-energy fitted a particular latex rubber used in our experiments. The second and...

Lambda polarization at 90 degrees in (positive kaon, lambda-hyperon) photoproduction

Donald Eugene Groom
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The polarization of [lambda] hyperons in the reaction [lambda] + p [...]K[superscript +] + [lambda] has been measured, using the Caltech synchrotron. The measurements were made at 90[degrees] in the c. m. system, at laboratory photon energies of 1100 MeV, 1200 MeV, and 1300 MeV. Protons from the asymmetric decay of the [lambda] were detected by...

Conical techniques for incompressible non-viscous flow

Allen I Ormsbee
An analytical investigation was made of incompressible potential flow fields in which the velocity components are homogeneous of order zero. Superpositions of such fields were then made and expressions were derived for the flow fields associated with constant-strength source and vortex sheets of finite extent. The constant strength source-sheets were then applied to the construction of aerodynamic models of thin non-lifting wings of polygonal platform and airfoil section. By use of the constant strength vortex-sheets,...

Angular correlation experiments with the F19(p, alpha gamma)O16 reaction

Hugh Jack Martin
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. A strong-focussing magnetic particle spectrometer was constructed and its properties and performance are discussed. Angular correlation patterns for the [...] reaction were measured at incident proton energies of 874, 935, 1250, 1280, 1346, and 1372 kev. Confirmation of previous level assignments was found in all cases. Some level parameters, connected with alpha emission, are evaluated for...

The Near Wake of a Two-Dimensional Hypersonic Blunt Body with Mass Addition

Donald James Collins
An experimental investigation of the steady, laminar nearwake flow field of a two-dimensional, adiabatic, circular cylinder with surface mass transfer has been made at a free-stream Mach number of 6. 0, and free-stream Reynolds numbers Re∞,d=0.9 and 3.0x104. A flush-mounted porous section was used to transfer argon, nitrogen or helium into the near wake of the circular cylinder to determine the flow field associated with the addition of a passive scalar. Two cases were studied:...

A small perturbation theory for cycloidal propellers

Edwin Charles James
A hydromechanical theory is developed for cycloidal propellers for two limiting modes of operation wherein U » ΩR and U « ΩR, with U the rectilinear propeller speed (speed of advance) and ΩR the rotational blade speed. A first order theory is developed from the basic principles of the kinematics and dynamics of fluid motion and proceeds from the point of view of unsteady hydrofoil theory. Explicit expressions for the instantaneous forces and moments produced...

Contributions to the three-dimensional vortex element method and spinning bluff body flows

Philippe Chatelain
Several contributions to the three-dimensional vortex element method for incompressible flows are presented. We introduce redistribution schemes based on the hexagonal lattice in two dimensions, and the face-centered cubic lattice in three dimensions. Interpolation properties are studied in the frequency domain and are used to build high-order schemes that are more compact and isotropic than equivalent cubic schemes. We investigate the reconnection of vortex rings at small Reynolds numbers for a variety of configurations. In...

Biological electron transfer in copper proteins

Cynthia N Kiser
Nature has used a variety of protein systems to mediate electron transfer. In this thesis I examine aspects of the control of biological electron transfer by two copper proteins that act as natural electron carriers. In the first study, I have made a mutation to one of the ligand residues in the azurin blue copper center, methionine 121 changed to a glutamic acid. Studies of intramolecular electron transfer rates from that mutated center to covalently...

Mechanosensitive channels of bacteria: structure and function

George G. Shapovalov
Mechanosensitive (MS) ion channels commonly play a role of transducers converting mechanical stimuli into electrical or chemical signaling, thus allowing the cell to regulate its behavior in response to changing environment conditions. MS channels participate in sensation of sound and orientation in inner ear (hair cells), in touch sensation and in osmoregulation of bacteria. Structure of bacterial MS channels of large (MscL) and small (MscS) conductance has been recently solved at atomic resolution, stimulating various...

A Petrov-Galerkin Finite Element Formulation for Convection Dominated Flows

Alexander Nelson Brooks
In this thesis, a new finite element formulation for convection dominated flows is developed. The basis of the formulation is the streamline upwind concept, which provides an accurate multidimensional generalization of optimal one-dimensional upwind schemes. When implemented as a consistent Petrov-Galerkin weighted residual method, it is shown that the new formulation is not subject to the artificial diffusion criticisms associated with many classical upwind methods. The effectiveness of the streamline upwind/Petrov-Galerkin formulation for the linear...

Fault tolerance using whole-process migration and speculative execution

Justin David Smith
This thesis examines programming language concepts that facilitate fault-tolerant distributed programming. New language primitives are introduced for whole-process migration, which allows an active process to be transferred from one machine to another, and speculative execution, which enables optimistic computing based on an unverified assumption. These primitives are developed in the context of the Mojave Compiler Collection, a multi-language multi-architecture compiler with ties to the MetaPRL theorem prover. The new primitives are first discussed from a...

Test of the ΔS = ΔQ Rule and CP-Invariance in K_(e3) Decay

John Daniel Gallivan
The complex quantity X = (amplitude of the ΔS = -ΔQ process K-o → π-e+v/amplitude of the ΔS = +ΔQ process Ko → π-e+v) has been measured in a counter-spark-chamber experiment at the LRL Bevatron. Assuming CPT invariance, ImX ≠ 0 implies CP-violation in the decay. Ko - mesons were produced in two brass targets by 2.85 GeV/c pions. A series of veto counters and hodoscopes selected neutral decays into two charged particles. The electron...

CP and the three pion decay of the K°

Michael Leigh Mallary
The time distribution of the decays of an initially pure K° beam into π+π-π° has been analyzed to determine the complex parameter W (also known as Ƞ+-° and (x + iy)). The K° beam was produced in a brass target by the interactions of a 2.85 GeV/c π- beam which was generated on an internal target in the Lawrence Radiation Laboratory (LRL) Bevatron. The counters and hodoscopes in the apparatus selected for events with a...

Compactness of Conformal Metrics with Integral Bounds on Curvature

Matthew J. Gursky
In this thesis, we show that a sequence of conformal metrics on a compact n-dimensional Riemannian manifold (n ≥ 4) which has an upper bound on volume and an upper bound on the LP[...] norm of the curvature tensor for fixed p > n/2 has a subsequence which converges in Cα. If n = 3, we have the same result if we assume, in addition, that the scalar curvature has an L2 bound. As corollaries,...

The Measurement of Magnetic Moments of Excited States in Palladium, Tungsten, and Thulium Nuclei

Elton Neil Kaufmann
The perturbed gamma - gamma angular correlation technique has been used to measure the magnetic moments of several nuclear excited states. The magnetic moment of the second excited 2+ state in 106Pd has been measured to be μ = 0.74 ± 0.14 nm, in good agreement with the interpretation of that state as a two-phonon quadrupole vibration about spherical equilibrium. The magnetic moment of the two-quasiparticle 2- state at 1289 keV in 182W has been...

The molecular structures of some simple olefins and small ring compounds

James Paul McHugh
The structures of three simple olefins and three small ring compounds containing double bonds have been determined by electron diffraction, and the results discussed in terms of hyperconjugation, rehybridization, strain, and intramolecular repulsions. In Part I, the structures of propene, isobutene, and cis butene-2 are described. The single bonds in these molecules have a length of about 1.50 A, exhibiting about half the shortening found in single bonds adjacent to triple bonds. In Part II,...

Analysis of Millimeter and Microwave Integrated Circuits

Richard C. Compton
The design and measurement of millimeter and microwave integrated circuits encompasses a diverse spectrum of interesting disciplines. A number of contrasting approaches used for theoretically and experimentally characterizing circuits in this frequency range will be presented. Rigorous methods for calculating antenna patterns and impedances of the planar bow-tie antenna used in millimeter wave receiver systems have been developed. A 94 GHz antenna measurement system and microwave scale models were constructed to confirm these theoretical predictions....

Corroles

Jeremy John Weaver
Corroles, porphyrin analogues, are the center of a rapidly growing field of research. By virtue of a missing meso-carbon, corroles retain the aromaticity of porphyrins, but become tribasic ligands in place of the dibasic porphyrin. This thesis is a study of synthetic methods for corroles, as well as their photophysical properties and potential applications. New synthetic methodologies for the free-base molecules have been used to obtain corroles with pentafluorophenyl meso substituents in both water-soluble and...

Higher order approximations for transonic flow over slender bodies

Nateson Srinivasan
No abstract.

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