Towards high resolution mapping of 3-D mesoscale dynamics from observations

The MyOcean R&D project MESCLA (MEsoSCaLe dynamical Analysis through combined model, satellite and in situ data) was devoted to the high resolution 3-D retrieval of tracer and velocity fields in the oceans, based on the combination of in situ and satellite observations and quasi-geostrophic dynamical models. The retrieval techniques were also tested and compared with the output of a primitive equation model, with particular attention to the accuracy of the vertical velocity field as estimated through the <b><i>Q</i></b> vector formulation of the omega equation. The project focused on a test case, covering the region where the Gulf Stream separates from the US East Coast. This work demonstrated that innovative methods for the high resolution mapping of 3-D mesoscale dynamics from observations can be used to build the next generations of operational observation-based products

Ferrite recrystallization and austenite formation during annealing of cold-rolled advanced high-strength steels: In situ synchrotron X-ray diffraction and modeling

Ferrite recrystallization and austenite formation occurring during annealing of cold-rolled advanced high-strength steels are key mechanisms as they largely determine the final microstructure and mechanical properties. However, the influence of processing parameters on these mechanisms and their interactions is still not fully understood. This is particularly the case for Dual-Phase steels having an initial cold-rolled microstructure con-sisting of ferrite and martensite before annealing, which were scarcely investigated compared to ferrite-pearlite initial microstructures. In situ synchrotron X-ray diffraction experiments together with post-mortem metallo-graphic analysis allowed clarifying both ferrite recrystallization and austenite formation during annealing of a ferrite-martensite initial microstructure depending on the process parameters of the annealing cycle. Results showed a major influence of recrystallization state on austenite formation, leading to an unexpected effect of heating rate on austenite formation kinetics. A modeling approach was undertaken to rationalize the influence of heating rate on austenite formation by taking into account the bi-phased ferrite-martensite initial microstructure and the effect of ferrite recrystallization state

A review of the zooplankton in Singapore waters

24 pages, 1 figure, 2 tablesThe island of Singapore is located between 1°09'N¿1°29'N and 103°38'E¿104°06'E at the confluence of the Malacca Straits and the South China Sea. To date, both the marine and freshwater zooplanktons of this area are poorly studied, and availability of taxonomic identification is scarce. Moreover, most of the studies were published between the 1950s to the beginning of the 1970s. The available data are mainly qualitative, with only a few studies on zooplankton biology and ecology. Here, the literature on zooplankton communities in Singapore waters is reviewed in order to provide a baseline for future zooplankton surveys, and to better understand the aquatic ecosystems of this area. Also included are recent data obtained from a one-year plankton monitoring in 2012 from two marine stations in Singapore. The temporal variation of the plankton groups was observed in the study to be similar to what was described in some works from the 1970s. The species richness increased in these more recent studies, probably due to changes in the sampling and preservation methods. Because of these changes, comparing between data-sets is challenging; however, similarities in species richness and seasonality between a recent study and previous data-sets were evident. Finally, it is argued that continuous marine plankton monitoring would be an asset for Singapore and the regionThe authors would like to thanks the National Parks of Singapore, the DHI-NTU Research Centre for the financial support of project MadeInPlankton, where the present study is framed. The work was also supported by Elite Forsk grants nb 10-093759 and 10-094773 from the Danish Agency for Science Technology and Innovation to GD, and by project PROTOS (CTM2009-08783) from the Spanish Ministry of Science and Innovation to ACPeer Reviewe

Study of cracks propagation inside the steel on press hardened steel zinc based coatings

Al-Si coating is the most suitable solution for main Hot-Forming applications, particularly in terms of processwindow for the hot stampers and in perforating corrosion resistance after austenitization. But for some specificcases, a few customers require galvanic edge protection. So, in order to satisfy this requirement zinc basedcoatings were developed for Hot-Forming.On these Zn based coatings a full microstructural characterization was carried out on the coating influence onthe steel/coating interface during the hot stamping. It appears that some cracks propagation is alwaysobserved inside the steel with Zn based coatings. Two separate cases corresponding to two mechanisms have tobe distinguished: Macro and Micro-cracks. The MACRO-cracks propagation is related to a liquid zincpenetration inside the previous austenitic steel grains boundaries. This is encountered for areas showing ahigh level of tensile stress with remaining liquid Fe-Zn phases in the coating during the deformation. Thus, acold deformation is a preliminary step for GI coating. The MICRO-cracks propagation is related to a frictionissue between the coating surface and the tools at high temperature. The higher micro-cracks density isconsequently observed on areas more sensitive to friction. The phases inside the steel responsible for thispropagation have been identified. Some solutions to avoid these phenomena are proposed, particularly in thecase of the micro-cracks for Direct Hot-Forming applications (GA coatings)