Numerical Model of Storm Surge and Inundation in Bohai Bay

A two-dimensional numerical model of extratropical storm surge and inundation in Bohai Bay was built based on the unsteady flow Navier-Stokes equations. The model included two sections, one was for the simulation of storm surge tidal level and the other for the simulation of storm surge inundation in the coastal area. While simulating the storm surge tidal level, the alternating direction implicit (ADI) method was applied to dispersing and solving 2D storm surge equations. In the simulation of storm surge inundation, the 2D unsteady flow equations were dispersed and solved using the structureless grids of finite volume method (FVM). A coupling calculation mode of the process of inundation and storm surge tidal level variation was proposed, therefore the storm surge inundation process and area could be calculated while simulating and forecasting the process of storm surge tidal setup. Furthermore, an extratropical storm surge and inundation in Bohai Bay were simulated using this numerical model. Simulation results are in good agreement with the measured data, which shows that this numerical model provides a new method of simulating and forecasting storm surge and inundation in Bohai Bay.

Computational Study on Interaction Between Swimming Fish and Drifting Vortices Behind the Cylinder

To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary force correction is used to save the computational cost and memory,and the momentum forcing is described by a simple direct force formula without complicated integral calculation when the velocity correction at the boundary node is determined.With the presented flow solver,the hydrodynamic interaction between the fish-induced dynamic stall vortices and the incoming vortices in unsteady flow is analyzed.Numerical simulation results unveil the mechanism of fish exploiting vortices to enhance their own hydrodynamic performances.The superior swimming performances originate from the relative movement between the“merged vortex”and the locomotion of the fishtail,which is controlled by the phase difference.Formation conditions of the“merged vortex”become the key factor for fish to exploit vortices to improve their swimming performance.We further discuss the effect of the principal components of locomotion.From the results,we conclude that lateral translation plays a crucial role in propulsion while body undulation in tandem with rotation and head motion reduce the locomotor cost.

Phenolic Antioxidants in Cypriot Wines as a Tool for Their Varietal Discrimination： Preliminary Results

A total of 56 wines from different vintages and wine-growing regions of Cyprus were used to analyze six biologically interesting phenolic antioxidants （gallic acid, catechin, vanillic acid, epicatechin, coumaric and feroulic acid） by high performance liquid chromatography. The study includes red and white Cypriot authentic wines from local and imported varieties that were produced under the same vinification conditions at a Model Winery. Results extracted after the chemometric analysis of the measured concentrations show a strong relationship of the phenolic antioxidative capacity with the variety of the wines and gallic acid followed by vanillic acid found in the highest concentrations of the other antioxidants studied. Comparing the concentrations found with bibliographic data for wines from other countries, it was found that, the concentration levels of vanillic and ferulic acid were significantly higher for Cypriot wines.

Positron-Electron Annihilation Process in(2,2)-Difluoropropane Molecule

The positron-electron annihilation process in(2,2)-difluoropropane molecule and the corresponding gammaray spectra are studied by quantum chemistry method.The positrophilic electrons in(2,2)-difluoropropane molecule are found for the first time.The theoretical predictions show that the outermost 2s electrons of fluoride atoms play an important role in positron-electron annihilation process of(2,2)-difluoropropane.In the present scheme,the correlation coefficient between the theoretical gamma-ray spectra and the experiments can be 99%.The present study gives an alternative annihilation model for positron-electron pair in larger molecules.