No description available.

No description available.

The tomographic reconstruction of hypersonic flows faces two challenges. Firstly, techniques used in the past, such as the Direct Fourier Method (DFM) or various backprojection techniques, have only been able to reconstruct areas of the flow which are upstream of any opaque objects, such as a model. Secondly, shock waves create sharp discontinuities in flow properties, which can be difficult to reconstruct both in position and in magnitude. This thesis will present a reconstruction method, utilising geometric ray-tracing and a sparse matrix iterative solver, which is capable of overcoming both of these challenges. It will be shown, through testing with phantom objects described in imaging and tomographic literature, that the results are comparable to those produced by the DFM technique. Finally, the method will be used to reconstruct three dimensional density fields from interferometric shock tunnel images, with good resolution.

The character of the primary seismic wave in the range of distances between 100 and 600 km is affected by such factors as the nature of the source, exponential attenuation, crustal structure, type of wave propagation, recording site geology and instrument response. The first arrivals from the GNOME and SHOAL nuclear explosions were analyzed to show the important effects of the above factors. Crusta1 structures were developed to examine the type of wave propagation, geometrical attenuation, and Q versus depth structure. Within the frequency bands delineated by the instrument response, above 2 cps, and the reliable source energies, exponential attenuation and surface geology explained the major spectral variations in the first arrivals. Amplitude variations were explained almost entirely by geometrical and exponential attenuation. Techniques for measuring exponential attenuation were developed and applied. The Q values obtained were primarily between 100 and 200. / Graduation date: 1968

Thesis (doctoral)--Cranfield Institute of Technology, 1991. / BLDSC reference no.: DX94724.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, December 2009. / Thesis Advisor(s): Hixson, Robert S. Second Reader: McNelley, Terry. "December 2009." Description based on title screen as viewed on January 27, 2010. Author(s) subject terms: Porous foams, dynamic compaction, multi-layered armor, ballistic performance, shock wave attenuation. Includes bibliographical references (p. 89-90). Also available in print.

Thesis--University of Florida. / Manuscript copy. Description based on print version record. Vita. Bibliography: leaves 79-80.

Thesis--Tekniska Högskolan, Stockholm. / Extra t.p., with thesis statement, inserted. Bibliography: p. 133-139.

Thesis (Ph. D.)--Ohio State University, 1970. / Includes bibliographical references (leaves 92-94). Available online via OhioLINK's ETD Center.

No description available.