Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 2004. / Vita. Abstract. Includes bibliographical references (p. 234-243).

Thesis (Ph. D.)--University of Wisconsin, 1916. / Bibliography: p. 193-200.

No description available.

No description available.

Thesis (Doctorat)--Université de Rennes, 1910. / Includes bibliographical references (p. [255]-260).

Horizons responsible for the reflection of seismic waves within deep-sea sediments are shown to be less reliable for the purposes of correlation than their counter-parts in shallow margin sequences. Similar surfaces, such as abrupt lithological changes and unconformities, in the two different realms are not neccessarily produced by the same processes. It is the nature of these processes which control the chronostratigraphic significance of a reflector. Thus reflectors may be correlated with reference to their genetic process. Horizons caused by time-restricted physical processes have enhanced chronostratigraphic significance. In the deep-sea, layers in which the physical properties change slowly with depth (transition layers) are also important for reflector formation. In as much as these transitions can be affected by temperature, pressure and sediment geochemistry, as well as time, the equation of an horizon at two different localities does not neccessarily imply correlation in time (i.e. the horizon is not neccessarily a chronostratigraphic time line). The two most important factors affecting impedance are the primary sedimentary geochemical composition and the nature of the grain to grain contacts within the sediment. Impedance increases with increasing grain density and increased rigidity of the sedimentary frame. The inter-dependance of all sediment physical properties greatly complicates the study of the relationships between them. Modelling can be used to demonstrate the affects of variation of individual properties. Synthetic seismograms can be generated using either physical properties data measured from discrete samples or from wire-line data. While quality is a limiting factor to the performance of .-. physical properties modelling, the latter is of value in that it enables modelling at many more localities than is possible with wire-line techniques alone. Abrupt impedance contrasts that produce reflectors important in deep-sea seismic stratigraphy may be grouped into a) Compaction horizons produced by gradual increase in over-burden pressure, b) Cementation horizons produced by variation in diagenesis with depth c) Calcite compensation depth (CCD) controlled horizons characterised by marked variation in primary sedimentary content and d) Unconformities produced by bottom current action.

The kinetic energy density, k, and lifetime, t, of a turbulent eddy, volume V, are shown to be related to a characteristic length scale, 2, by: 13 =vk= c2/3e2/3 t-C 1/312/3 where c is the energy dissipation rate. A self similar cascade of discrete eddy sizes is derived, each size related to the next larger by: P 22 CC i+l i where C= 81'2. With some simple assumptions as to the turbulent production process the mean logarithmic velocity profile is derived. The relationship between the friction velocity and Reynolds stress is explained in terms of the large eddy intermittency, n. Below a critical free stream velocity, U', n is proportional to the free stream velocity. The dissipation rate, e, is then constant and given by: e U'3/N3L where N is the number of discrete eddy sizes in the boundary layer. When the boundary layer has reached the surface N- 11. The observed turbulent spectral characteristics are derived from the eddy equations without using dimensional reasoning and an explanation of the mechanism behind surface layer similarity scaling is proposed. An experiment was carried out in the North Sea to test the model predictions. Correlations showed that, except at slack water, the largest eddies were approximately cubic, occupying the whole flow depth, and were advected with the mean flow. Frequency spectra provided evidence that the cascade formulation was correct. The turbulent intermittency was proportional to the current speed and the value of c, calculated by several methods, was found to be constant with a value: C=0.3 cm2/s3 The characteristics of the largest eddies were isolated using a spectral cropping technique and plotted as a phase portrait of the turbulent strange attractor. This demonstrated that the boundary layer sat at preferred, discrete energy levels. The levels observed could be related to the discete cascade model. A computer code based on the model equations was tested against a series of large scale oil and dye releases in the North Sea. The observed intermittency, meandering, and dispersion were well simulated with the value of c given above.

published_or_final_version / Geography and Geology / Master / Master of Philosophy

Thesis (LL. M.)--Judge Advocate General's School, U.S. Army, 1966. / "4th April, 1966." Typescript. Includes bibliographical references (leaf 38). Also issued in microfiche.

Thesis (doctoral)--Georg-August-Universität zu Göttingen. / "Erläuterung der abkürzungen und literatur-verzeichnis": p. [vii]-xii.