A 1/12°, 2-D barotropic tide model was used to examine the characteristics of barotropic tides and to improve the accuracy of predicting tidal sea levels and currents in the seas around Taiwan. The form ratio suggests that tides are predominantly semidiurnal in the northern reaches of the Taiwan Strait and mixed of diurnal and semidiurnal elsewhere around Taiwan. When the dominant M 2 wave enters the Strait from the north, its amplitude is magnified to ~2 m in the middle, and then decreases rapidly toward the south end of the Strait. The predominance of diurnal tides along the southwest to the south coast of Taiwan is attributed to the quasi-resonance of diurnal waves in the South China Sea. The tidal range is small and tidal currents are weak off the east coast of Taiwan. Barotropic tidal energy is mostly dissipated on the shallow banks of the southwestern Strait. Results summarized from sensitivity tests on the bottom drag coefficient (C D) and horizontal eddy viscosity (A M) indicate that C D = 0.0015-0.00175 and A M = 150 m 2 s-1 lead to the best model-data fit when compared to the observed tidal sea levels at ten reference tide-gauge stations around Taiwan. The averaged root-mean-squared (RMS) differences of the simulated tidal sea level for the six principal constituents of O

A numerical procedure was performed to simplify the complicated mechanism of an epitaxial thin-film growth process. In this study, three numerical mechanism models are presented for verifying the growth rate of the gallium nitride (GaN) mechanism. The mechanism models were developed through rate of production analysis. All of the results can be compared in one schematic diagram, and the differences among these three mechanisms are pronounced at high temperatures. The simplified reaction mechanisms were then used as input for a two-dimensional computational fluid dynamics code FLUENT, enabling the accurate prediction of growth rates. Validation studies are presented for two types of laboratory-scale reactors (vertical and horizontal). A computational study including thermal and flow field was also performed to investigate the fluid dynamic in those reactors. For each study, the predictions agree acceptably well with the experimental data, indicating the reasonable accuracy of the reaction mechanisms.

Abstract:A numerical verification procedure and the effects of operating conditions in a large, vertical, and close-spaced reactor for metalorganic chemical vapor deposition are investigated through simulation and analysis. A set of epitaxy experiments are presented for verifying the growth rate of the gallium nitride (GaN) mechanism reported in our previous study. The full governing equations for continuity, momentum, energy, and chemical reaction are solved numerically. The results show that the real operating parameters (susceptor temperature: 1188 • C or 1238 • C; pressure: 100-300 torr) affect thin-film uniformity, and the predicted growth rates agree reasonably well with the experimental data, indicating the accuracy of the projected chemical reaction mechanisms.

In this paper, the effects of operating conditions in a large-size, vertical and close-spaced reactor for metalorganic chemical vapor deposition are investigated and described by simulation and analysis. The parameters are involved such as space between gas inlet and susceptor (11-20 mm), reactor wall temperature (50-200℃), gas inlet temperature (50-200℃),and chamber pressure (100-760 torr). These listed parameters show that an optimization ideal stagnation flow can be achieved in a large-size close-spaced reactor.

This work has utilized the anodic oxidation method to fabricate the TiO2 nanotube arrays which were then applied as the anode to the dye‐sensitized solar cells (DSSCs). Surface morphology of TiO2 nanotube arrays, the length and the pore diameter of the nanotubes were observed by FE‐SEM. With XRD analysis, the annealed TiO2 nanotube array has been identified as the anatase phase which can enhance the electron transition in the TiO2. The influence of the TiO2 nanotube arrays to the absorption of the dye molecules was examined by UV‐VIS spectroscopy. It is found that the TiO2 nanotubes with longer lengths can improve the dye absorption, thus increases the photovoltaic conversion efficiency of the DSSCs. The DSSCs with TiO2 nanotube arrays have achieved photovoltaic conversion efficiency as high as 4.62% in this work.