No description available.

Presented first November 1971, and revised July, 1972

<p>The material consumption of the foundation of a WEC is a big part of the totalmaterial consumption of the entire power plant. To reduce these consumption, it isrequired to optimize the foundation. To find out how small the foundation could beconstructed and still be able to cope with the requirements, it is necessary to knowabout the various forces that affects the foundation. The focus in this thesis is on theforces acting on the buoy. The forces are calculated theoretical with experimentsconducted to reach conclusions about the size of the gravity foundation.Experiments will also be conducted to investigate experimentally whether there is anydifference between the suction force of sand and clay soil.Results from experiments with buoys show that the theoretical calculations arereasonably close with results from experiments. Conclusion of the differencesbetween theory and experiment is found that this may be due to the wave tank abilityto reproduce waves, and the angle between the buoy and the wave direction.Results from experiments of the suction force shows that there is no differencebetween sand and clay. The conclusion from this experiment is that the results applyonly to the clay that was investigated in this experiment and cannot be compared withother clay types with different properties.A discussion about the foundations is carried out where the conclusion is drawn thatthe foundations for the minimum mass to maintain equilibrium at 4 m wave height isapproximately 33 ton.</p>

Thesis (Ph. D.)--Rijksuniversiteit te Leiden, 1970. / Includes bibliographical references (p. 82-83).

The material consumption of the foundation of a WEC is a big part of the totalmaterial consumption of the entire power plant. To reduce these consumption, it isrequired to optimize the foundation. To find out how small the foundation could beconstructed and still be able to cope with the requirements, it is necessary to knowabout the various forces that affects the foundation. The focus in this thesis is on theforces acting on the buoy. The forces are calculated theoretical with experimentsconducted to reach conclusions about the size of the gravity foundation.Experiments will also be conducted to investigate experimentally whether there is anydifference between the suction force of sand and clay soil.Results from experiments with buoys show that the theoretical calculations arereasonably close with results from experiments. Conclusion of the differencesbetween theory and experiment is found that this may be due to the wave tank abilityto reproduce waves, and the angle between the buoy and the wave direction.Results from experiments of the suction force shows that there is no differencebetween sand and clay. The conclusion from this experiment is that the results applyonly to the clay that was investigated in this experiment and cannot be compared withother clay types with different properties.A discussion about the foundations is carried out where the conclusion is drawn thatthe foundations for the minimum mass to maintain equilibrium at 4 m wave height isapproximately 33 ton.

The aim of this investigation in Offatts Bayou was to quantify natural shifts in distributions and abundances of algal groups and to examine spatio-temporal patterns of abiotic and biotic characteristics in the water column over a one year period. To accomplish this, hydrological and meteorological parameters were collected and phytoplankton biomass, community composition and chlorophyll a data were examined for significant relationships. Seasonal variations in water temperature, salinity, dissolved oxygen concentrations and pH levels, as well as wind effects, zooplankton grazing, light availability and hydrodynamic restriction were considered as the key controlling factors in phytoplankton dynamics in Offatts Bayou. Surface water samples and water column hydrological data were collected at eleven stations in the Offatts Bayou embayment on a regular basis (2 to 4 times per month), along with phytoplankton tows on a monthly basis. Spatial patterns of phytoplankton abundance generally reflected the degree of circulation in Offatts Bayou with higher abundances observed in the restricted areas and lower abundances in the well mixed regions. Temporally, diatom blooms became more prominent during winter, spring and autumn, which were characterized by cooler temperatures, less light availability, increased dissolved oxygen concentrations and reduced salinities than observed in summer. The most dominant diatoms were Guinardia delicatula, Ditylum brightwelli, Rhizosolenia setigera, Dactyliosolen fragillissimus and numerous Chaetoceros species. During summer, the waters of Offatts Bayou were warmer and more saline, which lead to the haptophyte, Corymbellus aureus, becoming the dominant taxa, with highest standing crops at the circulation restricted stations in Lake Madeline. While the results of this study support the importance of temperature, dissolved oxygen and pH as the critical controlling factors (p < 0.05) of phytoplankton biomass and diversity, it is clear that phytoplankton dynamics in Offatts Bayou must be viewed within the broader context of additional parameters such as salinity, stratification and wind effects. The progressively degrading conditions within Offatts Bayou emphasize the significance of studying and understanding the interrelationships of factors and mechanisms that influence phytoplankton dynamics. Long term monitoring of Offatts Bayou is essential for tracking, recording and assessing various human impacts to phytoplankton distribution, abundance, and productivity as well as impacts to higher trophic levels such as fish and humans.

Two problems in mesoscale wave dynamics are addressed: (i) wave-turbulence interaction in a breaking mountain wave and (ii) gravity wave generation associated with coastal heating gradients. The mean and turbulent structures in a breaking mountain wave are considered using an ensemble of high-resolution (essentially LES) wave-breaking calculations. A turbulent kinetic energy budget for the wave shows that the turbulence production is almost entirely due to the mean shear. Most of the production is at the top of the leeside shooting ow, where the mean- ow Richardson number is persistently less than 0:25. Computation of the turbulent heat and momentum uxes shows that the dissipation of mean- ow wave energy is due primarily to the momentum uxes. The resulting drag on the leeside shooting ow leads to a loss of mean ow Bernoulli function as well as a cross-stream PV ux. The dependence of both the resolved-scale and subgrid turbulent uxes on the grid spacings is examined by computing a series of ensembles with varying grid spacings. The subgrid parameterization is shown to produce an overestimate of the PV ux at low grid resolution. The generation of gravity waves by coastal heating gradients is explored using linear theory calculations and idealized numerical modeling. The linear theory for ow without terrain shows that the solution depends on two parameters: a nondimensional coastal width L and a nondimensional wind speed U. For U 6= 0 the solution is composed of three distinct wave branches. Two of these branches correspond to the no-wind solution of Rotunno, except with Doppler shifting and dispersion. The third branch exists only for U 6= 0 and is shown to be broadly similar to ow past a steady heat source or a topographic obstacle. The relative importance of this third branch is determined largely by the parameter combination U=L. The e ect of terrain is explored in the linear context using an idealized linear model and associated diagnostic computations. These results are then extended to the nonlinear problem using idealized nonlinear model runs.

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Thesis (Ph. D.)--California Institute of Technology, 2010. UM #89-15,388. / Title from home page. Viewed 12/02/2009. Advisor names found in the Acknowledgements pages of the thesis. Includes bibliographical references.

Thesis (Ph. D.)--California Institute of Technology, 1972. UM #72-22,550. / Advisor names found in the Acknowledgements pages of the thesis. Title from home page. Viewed 01/15/2010. Includes bibliographical references.