The inclusion of aviation into the EU emission trading scheme – Impacts on competition between European and non-European network airlines

In 2008, the European Commission, the European Parliament and the European Council agreed on including international aviation in the already existing European Union carbon market. From 2012, allowances will be required for all international flights landing at and departing from any airport in the EU. Domestic aviation will be subject to the same rules as international air traffic. Model-based empirical estimations presented in this paper indicate a diverse set of effects influencing competition between European and non-European aircraft operators. Initially, this paper provides an overview on recent political developments on EU as well as on International Civil Aviation Organisation level on the subject of emissions trading and aviation. Subsequently, our modelling approach and the main results concerning impacts on operating costs, ticket prices and cargo rates for European and non-European aircraft operators are presented and discussed. Finally, conclusions about the impacts on competition between European and non-European airlines are drawn.     

纵横乾坤是班轮(下)

(接上期54页) 公司规模 究竟一个企业做多大才合适呢?经验和统计数据告诉我们,公司的业务规模确实与其市场份额存在一定的相关性.这里有一个班轮公司,我想大家都不会感到陌生,在20世纪80年代,它堪称国际集装箱班轮业的巨无霸,它就是著名的美国海陆集装箱运输有限公司.当时,它的业务量曾经达到了全球市场份额的9.8%.德国哈帕格·劳埃德箱运公司紧随其后,排名第二位,市场份额约为6.2%,该公司的发展速度一直比较快.在其它20大班轮公司中,8家公司的市场份额在2.5～3.5%之间.1999年,随着丹麦马士基成功收购美国海陆公司,马士基跃居全球第一大班轮公司,但即便如此,该公司当时的市场份额也只有6%.     

Use of SeaWiFS data for light availability and parameter estimation of a phytoplankton production model of the Bay of Biscay

Processing SeaWiFS (Sea-viewing Wide Field-of-view Sensor) data provides useful information for the observation and modelling of the phytoplankton production of the Bay of Biscay. Empirical algorithms allow the retrieval of chlorophyll a and non-living Suspended Particulate Matter (SPM) concentrations. These data are used to constrain a coupled 3D physical–biogeochemical model of the Bay of Biscay continental shelf. Two issues are investigated, depending on the variable used, to constrain the winter to spring phytoplankton production for the year 2001. First, SPM data is used as forcing data to correct the corresponding state variable of our model. This allows the realistic simulation of the light limited bloom at the end of February 2001, as observed with SeaWiFS chlorophyll a images and from the NUTRIGAS field cruise. Second, chlorophyll a data is used for parameter estimation of the biogeochemical model. The ability of assimilating these data is tested to improve the simulation of strong blooms observed in late May 2001 in the Loire and Gironde plumes. A global optimization method (Evolutive Strategies) is adapted to the complete 3-D coupled model, in order to find the best set of parameters. The hydrological conditions during the bloom can be validated with data from the PEL01 field cruise. After selection of the most sensitive parameters, the method is tested with twin experiments. Then, the use of real SeaWiFS data reduces the model/data misfit by a factor of two, improving the simulation of bloom intensities and extensions. The sets of parameters retrieved in each plume are discussed.     

Reduction of VIV using suppression devices—An empirical approach

Helical strakes are known to reduce and even eliminate the oscillation amplitude of vortex-induced vibrations (VIV). This reduction will increase the fatigue life. The optimum length and position of the helical strakes for a given riser will vary with the current profile.

The purpose of the present paper is to describe how data from VIV experiments with suppressing devices like fairings and strakes can be implemented into a theoretical VIV model. The computer program is based on an empirical model for calculation of VIV. Suppression devices can be accounted for by using user-defined data for hydrodynamic coefficients, i.e. lift and damping coefficients, for the selected segments.

The effect of strakes on fatigue damage due to cross flow VIV is illustrated for a vertical riser exposed to sheared and uniform current. Comparison of measured and calculated fatigue life is performed for a model riser equipped with helical strakes. A systematic study of length of a section with strakes for a set of current profiles is done and the results are also presented.