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Contains fulltext : 293326.pdf (Publisher’s version ) (Open Access)

Depositing homogeneous TiAlN coatings with a high Al content on cutting tool inserts is a challenging task. In this work, high-Al cubic Ti1- xAlxN coatings (average x = 0.8) with periodic Ti(Al)N (x = 0.5) and Al(Ti)N (x = 0.9) nanolamellae structure were synthesized by low pressure chemical vapour deposition (LPCVD) with different gas flow velocities, and the detailed microstructure was investigated by electron microscopy and simulations. Using a high gas flow rate, the columnar TiAlN grains with regular periodic nanolamella structures disappeared, the coating became enriched in Ti and hexagonal AlN (h-AlN) formed in the coating. The high Ti content is suggested to be caused by the high gas flow rate that increases the mass transport of the reactants. However, this does not influence the Al-deposition much as it is mainly limited by the surface kinetics due to the relatively low deposition temperature. Density functional theory (DFT) modelling and electron microscopy showed that h-AlN tends to form on the Ti(Al)N phase with a specific crystallographic orientation relationship. The Ti enrichment due to high gas flow rate promotes the formation of h-AlN, which therefore deteriorates the nanolamella structure and causes the disappearance of the columnar TiAlN grains. Thus, by designing the CVD process conditions to avoid too high gas flow rates, homogenous TiAlN coatings with high Al content and nanolamella structures can be deposited, which should yield superior cutting performance., QC 20200422

The European eel (Anguilla anguilla L.) is an economic important species and is listed on the IUCN red list as critically endangered. Nonetheless, each year between late winter (February) and late spring (May) glass eels arrive at the various coastal areas attempting to migrate to freshwater habitat. As part of the statutory tasks (WOT) a yearly index of glass eels arriving at the sluices at Den Oever was created since 1938. The program consists of a monitoring with liftnets and traps and is commissioned by Wageningen Marine Research (WMR). In addition, WMR also equips glass eels with a Visible Implant Elastomer tag to determine abundance and differences in retention time between years since 2019 using (batch) mark- and recapture methods. However, effects of tagging in relation to predation risk are unknown. Tagged glass eels might have an increased risk for predation, which in turn would influence abundance and retention time estimates. This study aims to determine differences in predation risk when glass eels are equipped with a VIE tag and exposed to European sea bass (Dicentrarchus labrax). Also, this study aims to determine the feasibility of stomach content analysis of predatory fish for future field studies on predation of glass eels near barriers. To answer both questions a laboratory experiment was conducted using marked (red and blue) and unmarked glass eels which were exposed to sea bass for a 2-hour trial. If at least one glass eel was eaten, stomach content was analyzed by a hand pump. 48% of the trials showed successful predation and 13% showed clear attempts of predation but failed to eat glass eels. The other sea bass (39%) waited significantly longer to show some activity, and they moved significantly less. The study showed that no differences in predation risk for marked glass eels by European sea bass. Also, no difference was found in predation between red and blue marked glass eels. Stomach content analysis showed intact glass eel bodies after en