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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Percolation characteristics of various sediments

Biegler, Norman William January 2011 (has links)
Typescript, etc. / Digitized by Kansas State University Libraries
72

Aspects of Pleistocene glaciomarine sequences in the North Sea

Bent, Alistair John Alexander January 1986 (has links)
No description available.
73

Some aspects of optically stimulated luminescence for sediment dating

Short, Michael Anthony. January 1993 (has links)
published_or_final_version / Radioisotope / Master / Master of Philosophy
74

Shear wave attenuation in unconsolidated laboratory sediments

Brunson, Burlie A. 23 June 1983 (has links)
Shear wave attenuation measurements were made using ceramic bimorph transducers to excite transverse vibrations in a cylindrical column of unconsolidated sediment. Three different water-saturated sediments were used in an attempt to determine the effects of grain shape and sorting on the frequency dependence of attenuation. The mean grain size of the sediments was held constant while the grain shape and size distributions were varied. The sediment assemblages used in the attenuation measurements included a moderately-sorted angular quartz sand, a well-sorted angular quartz sand, and well-sorted spherical glass beads. The moderately-sorted sand showed the greatest attenuation over the measurement frequency range of 1 to 20 kHz. The well-sorted sand and the glass beads showed generally lower attenuation with the beads being the least lossy propagation medium. All three sediments showed evidence of viscous attenuation due to fluid-to-grain relative motion. This mechanism leads to a non-linear relationship between attenuation and frequency. Sediment physical properties were measured for use as inputs to a theoretical attenuation model based on the Biot theory of propagation of waves in porous media. The model allowed attenuation versus frequency predictions to be made for each of the three sediment assemblages. The resultant comparisons between the measured and predicted attenuations demonstrated the importance of using measured model inputs obtained under controlled laboratory conditions when theoretical model capabilities are being evaluated. The model comparison shed significant light on the ability of this particular model to predict shear wave attenuation in non-ideal sediments. / Graduation date: 1984
75

Elemental distributions in the components of metalliferous sediments from the Bauer and Roggeveen Basins - Nazca Plate

Lopez, Carlos 19 September 1977 (has links)
Major and trace element analyses were made on biogenic carbonate, silica, and fish debris and on authigenic philhipsite, micronodules, and yellow and brown aggregates recovered from Bauer and Roggeveen Basin metalliferous sediments. Phase components and the bulk samples were analyzed by INAA and MS methods. Leachates and residues from ammonium oxalate and mild HC1 leaches of bulk and fine sediment fractions were also analyzed. The mild acid leach removed fish debris and carbonate, and the oxalate leach dissolved the micronodule phase. Sediments of the Bauer and Roggeveen Basins differ in bulk composition, yet respond to various chemical treatments in similar manner. I interpret this as indicative of a close similarity in the mineralogy of these two areas. An iron-rich smectite, manganese micronodules, and fish debris dominate the sediment compositions of both basins. The smectite phase concentrates Fe, Si, and Al. Manganese, Co, Ni, Ce, and W are concentrated in the micronodule phase and Ca, Sc, and the lanthanides predominantly in the fish debris component. The trace elements Cu, Zn, As, and Sb are distributed in a complex manner among the three principal phases. Barium, and some Al and Fe, may be present in small quantities of barite, feldspars, and goethite, respectively. Silica, carbonate, and phillipsite phases exist in. such low concentrations that they do not contribute significantly to the bulk composition of the sediments. The response of the various size fractions leached indicates a uniformity of distribution of sediment components from the coarse to the fine fractions. / Graduation date: 1978
76

Gravel-bed stability and water quality variation in a lowland stream

Harris, T. R. J. January 1993 (has links)
No description available.
77

The evolution of coastal sand dunes in the southern isles of the Outer Hebrides of Scotland

Schwenninger, Jean-Luc January 1996 (has links)
No description available.
78

Radionuclides as tracers of sediment mixing in natural and enclosed estuaries

Williams, Mark Steven January 2002 (has links)
No description available.
79

An investigation of factors influencing the concentration of trace metals in the bottom sediments of the Forth estuary

Kershaw, P. J. January 1980 (has links)
No description available.
80

Oligocene and Miocene sedimentology in the southeastern part of the Malay Basin, offshore west Malaysia

Ramli, N. January 1986 (has links)
No description available.

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