Thesis (M. Sc.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 96-98).

Thesis (Ph. D.)--University of Hong Kong, 1991.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 154-166). Available also in a digital version from Dissertation Abstracts.

Thesis (M. Sc.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 94-104).

No description available.

No description available.

Thesis (degree (Master in Technology))--Cape Technikon, Cape Town,1996 / Red tides are a common feature of the southern Benguela upwelling system and are usually dominated by migratory flagellates and the ciliate Mesodinium rubrum. Seasonal blooms of dinoflagellates occur in response to seasonal upwelling and typically succeed diatom blooms. High biomass, multispecies red tides result from concentration by various physical forces and are characteristically found in warm, stratified, nutrient-depleted water overlying cold, nutrient-rich bottom water. The influence of turbulent mixing, light and the availability of nutrients on the migratory behaviour of red tide species was studied by means of both mesocosm and field studies. The mesocosm experiments were conducted in a 3m laboratory column in which a red tide community, collected from the field, was introduced above nutrient-rich bottom water. All the dominant species exhibited directed vertical migration, with ascent and descent starting before sunrise and before sunset respectively. Observations support the hypothesis that red tide organisms can sustain high concentrations in nitrogen depleted surface waters by growing at the expense of nitrate taken up during nocturnal descent. Vertical niche separation of different red tide species was evident both during the night and the day. Observations support the hypothesis that species are capable of coexisting within a red tide bloom. Division rates were determined from the frequency of paired nuclei and cells. C. furca recorded the highest growth rate (u = 0.24). The relatively low growth rates emphasise the importance of physical processes, as opposed to biological processes, in the formation of red tides within upwelling systems.

Abstract Tidal wave may be distorted when entering the river of large topography variations. The traditional tidal harmonic may not be applied well to data collected in such a shallow river. Godin (1998) indicated that the hydrodynamics of rivers is dominated by the damping and the distortion induced by quadratic bottom friction. This research try to analyze the distortion of tidal wave in the Tanshui River (northern Taiwan) based on field measurements. Sea levels data are collected at fours stations along the lower river: Pole (4km offshore), Tanshui harbor(on the coast), Kuan-Do Bridge (7km inland) and Yuan-Shan Bridge (18km inland). The total distance of the four stations is 22 km. The synchronizing sampling period is January 10 to February 28 of 2001 (50 days). The analysis is trying to identify the following issues. (1) The transformation of tidal wave from coastal into the river and upper stream. (2) The errors of tidal prediction based on harmonic analysis. Several different conditions are examined including spring-neap tides, influence of fresh water output and peaks of high-low water. The influence of bottom friction of the inner river stations is emphasized. The results show that distortion of tidal wave is more pronounce inside the river. The main reason is explained due to the strength of bottom friction, which is proportional to the flow velocity. (1) During spring tide, a stronger flow contributes a larger bottom friction. (2) A higher water level (h) may have a faster wave speed ( ) that high water occurred before the forecast. The deviation in high water also is more significant than that of low water. (3) River flow increases the water level and cause the deviation of wave propagation inside the river.

In multiresolution analysis(MRA)by wavelet function Daubechies (db), we decompose the signal in two parts, the low and high-frequency content,respectively. We remove the high-frequency content and reconstruct a new ¡§de-noise¡¨ signal by using inverse wavelet transform. In order to improve the forecasting accuracy of ANN (Artificial Neural Network) model ,we use the concept of tidal constituent phase-lags, and the new ¡§de-noise¡¨ signal was used as the input data set of ANN. Besides, we also use wavelet spectrum, conventional energy spectrum (Fast Fourier Transform, FFT),and harmonic analysis to analyze the character of tidal data . The results show that the concept of tidal constituent phase-lags can improve ANN model of tidal forecasting and supplement, but in the wavelet analysis , the improvement is insignificant .The reason is that the energy of higher frequency noise is very small compared to the energy of the diurnal and the semi- diurnal tidal components. In other word , the ANN model has a certain tolerance of noise effect .

The Late Cretaceous upper Sego Member of the Mancos Shale exposed in the Book Cliffs of east-central Utah is a 30 m thick sandstone wedge that overlies the Anchor Mine Tongue of the Mancos Shale and underlies coastal plain deposits of the Neslen Formation. Although this sandstone has been interpreted to be comprised of transgressive valley fills, recent detailed facies architecture studies of the underlying lower Sego Sandstone suggest these deposits may instead be regressive deposits of tideinfluenced deltas. This study maps facies associations, the geometry of lithic bodies, and key stratigraphic surfaces in order to define the architecture of a 12 km long cross section of the upper Sego Sandstone. This broadly depositional dip-oriented cross section exposes a vertical stack of three sandy intervals, truncated by a high-relief erosion surface, and capped by a shell rich lag. Sandy intervals are interpreted be an assemblage of forward stepping successions of tide-influenced delta lobes. Interval 1, dominantly highly marine bioturbated sandstones which thin landward over kilometers, is cut locally by an erosion surface overlain by tidal bed sets. It is capped by a localized transgressive shell lag and then a thin continuous marine shale. Intervals 2 and 3 are composed of stacked tidal bar deposits that successively coarsen upward and thicken basinward. Interval 2 is overlain by thin marine shales, whereas interval 3 is capped by a pronounced oyster shell lag ravinement surface. A high-relief erosion surface that extends from the top of the upper Sego sandstone down into the Anchor Mine Tongue Shale, is overlain by coarser-grained amalgamated fluvial channel deposits and is interpreted to be a incised valley fill. Erosion surfaces at the base of sandy intervals, thicken and decrease in marine bioturbation within successive intervals, and the valley cut into this succession reflects episodic forced regression of a deltaic shoreline.