Wave Loads and Protective Techniques of An On-Shore Wave Power Device

In this paper, the extreme wave loads on an on-shore wave power device are investigated. First, boundary element method is applied to solve the three dimensional potential problem based on the small amplitude wave assumption. Then the motion of the Oscillating Water Column (OWC) inside the device and its laods on the device are calculated in time domain. Several protective techniques often applied are simulated by changing the constraint of the upper end of the chamber of the device. Numerical results are used to judge the effectiveness of these techniques. The investigation shows that damping can not effectively restrain the motion of OWC when the period of incident wave is long, which may cause dangerous loads on the structure. The shut chamber can effectively restrain the motion of OWC, but alternatively cause high pressure in the chamber. A Contracting opening with a Taper (CT) can exhaust a great amount of kinetic energy of OWC, and significantly decrease the loads. It is a promising protective tec     

Risk of dike failure due to flow slides

Flow slides may affect the stability of dikes. A flow slide is an instability of a submerged slope caused by liquefaction of loose, (medium) fine sand. Whether a flow slide will occur depends on the properties of the sand, which are a function of its density, and the geometry of the slope, as determined by wave and current induced scour and sedimentation. The influence of sand properties and the geometry parameters on the risk of flow slides are discussed. The application of a flow slide prediction method to an example and a risk analysis is briefly discussed.     

The European vision for oceans and seas—Social and political dimensions of the Green Paper on Maritime Policy for the EU

The EU Green Paper on Maritime Policy is the European response to the new generation of ocean strategies based on science, technology and innovation aimed at new objectives, such as the strengthening of security and access to new resources. The European character of the proposal is found in the presence of social, cultural and historical elements, what is called the “European vision”. The viability of a European vision of the oceans and the idea of maritime empire as an extension of the current concept of empire within the general context of emerging ocean strategies are the elements offered up for debate on this European Union initiative.     

A community-wide intercomparison exercise for the determination of dissolved iron in seawater

The first large-scale international intercomparison of analytical methods for the determination of dissolved iron in seawater was carried out between October 2000 and December 2002. The exercise was conducted as a rigorously “blind” comparison of 7 analytical techniques by 24 international laboratories. The comparison was based on a large volume (700 L), filtered surface seawater sample collected from the South Atlantic Ocean (the “IRONAGES” sample), which was acidified, mixed and bottled at sea. Two 1-L sample bottles were sent to each participant. Integrity and blindness were achieved by having the experiment designed and carried out by a small team, and overseen by an independent data manager. Storage, homogeneity and time-series stability experiments conducted over 2.5 years showed that inter-bottle variability of the IRONAGES sample was good (< 7%), although there was a decrease in iron concentration in the bottles over time (0.8–0.5 nM) before a stable value was observed. This raises questions over the suitability of sample acidification and storage.     

黄鳍鲷LDH同工酶的组织特异性研究

以黄鳍鲷为材料进行两方面研究:（1）用聚丙烯酰胺凝胶电泳方法，对其肌肉，心脏，肝脏，血清，玻璃体，晶状体，脑等组织器官进行LDH同工酶分析比较，结果表明，不同组织中LDH的同工酶谱带不相同，存在着组织特异性：（2）用聚丙烯酰胺等电聚焦电泳法对其肌肉，血清的LDH同工酶进行分离 ，结果得到12－15条电泳区带，等电点范围在pH为3．65－9．58之间。     

Onshore Neogene stratigraphy in the North of the Alboran Sea (Betic Internal Zones): Paleogeographic implications

The Neogene is the period in which the Betic Cordillera, the Rif, and the Alboran Sea acquired their present configuration. The Neogene sediments of the Betic Internal Zones (located directly to the North of the Alboran Sea) show the effects of important periods of deformation. Deposition was clearly controlled by tectonics. Therefore the generation, evolution, and total or partial destruction of basins and the formation of new, often superimposed, basins are common phenomena, according to the locations of the basins in the Betic Cordillera and to the different geodynamic situations.     

Stability analysis of a two-inlet bay system

The stability analysis for a double-inlet bay system is applied to an inlet system resembling Big Marco Pass and Capri Pass on the lower west coast of Florida. Since the opening of Capri Pass in 1967, the length of Big Marco Pass has increased from 2000 m in 1967 to 3000 m in 1988 and the cross-sectional area has decreased from 1200 m² in 1967 to 1000 m² in 1988. Since 1967, the cross-sectional area of Capri Pass has steadily increased and in 1988 was 700 m². Tides off the inlets are of the mixed type with a diurnal range of 1 m. The gross littoral transport rate in the vicinity of the inlets is estimated at 150,000 m³ yr⁻¹.For each inlet the maximum tidal velocities are calculated as a function of the gorge cross-sectional areas using a lumped-parameter model to describe the hydrodynamics of the flow. In the model it is assumed that the bay level fluctuates uniformly and the bay surface area remains constant. The velocities are used to calculate the tidal maximum of the bottom shear stress in each inlet as a function of the cross-sectional areas of the two inlets (=closure surface). Values of the equilibrium shear stress are derived from an empirical relationship between cross-sectional area and tidal prism for stable inlets along the west coast of Florida. Closure surfaces and equilibrium stress values are calculated for values of friction factors ranging from F=4×10⁻³ to F=6×10⁻³. Using the closure surfaces and equilibrium stress values, the equilibrium flow curve for each inlet is determined. The equilibrium flow curve represents the locus of the combination of cross-sectional areas for which the actual bottom shear stress in the inlet equals the equilibrium shear stress.Based on the equilibrium flow curves and the known values of the cross-sectional areas of the two inlets in 1988, it is expected that, ultimately, Big Marco Pass will close and Capri Pass will remain as the sole inlet with a cross-sectional area of 1250 m² and a maximum tidal velocity pertaining to a diurnal tide of 0.85 m s⁻¹.