3-Oxo-18α-olean-28,13β-olide

The title terpene, C30H46O3, is a 28,13β-lactone of oleanolic acid prepared with bis­muth trifluoro­methane­sulfonate (OTf), Bi(OTf)3·xH2O. All rings are trans-fused. The X-ray study shows the inversion of the orientation of 18-H in the lactonization reaction. A quantum chemical ab-initio Roothaan Hartree–Fock calculation of the equilibrium geometry of the isolated mol­ecule gives values for bond lengths and valency angles in close agreement with experimental values. The calculation also reproduces the observed mol­ecular conformation, with puckering parameters that agree well with those determined from the crystallographic study

Spectrophotometric determination of chromium as the chromium-peroxo-4-(2-pyridylazo)resorcinol complex

Der ternäre Chrom-Peroxo-PAR-Komplex weist einen scheinbaren molaren Extinktionskoeffizienten von 6280 l · mol −1 · cm −1 auf, wenn er aus 0,1 M schwefelsaurer Lösung mit Ethylacetat extrahiert wird. Das Beersche Gesetz wird bis zu 6,0 μg Cr/ml befolgt. Die Bedingungen für eine optimale Farbbildung, die Zusammensetzung des Komplexes, die Wirkung verschiedener Begleitionen und die Anwendung auf Stähle werden beschrieben. The ternary complex chromium-peroxo-PAR exhibits an apparent molar absorptivity of 6280 l mol −1 cm −1 when extracted into ethyl acetate from 0.1 M sulfuric acid solution. Beer's law is followed for solutions containing up to 6.0 μg Cr ml −1 . Conditions for optimum color formation, complex composition, effects of diverse ions, and application to the determination of chromium in steels are described.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46457/1/216_2004_Article_BF00480608.pd

Exploring the Ambiguity of Operation Sophia Between Military and Search and Rescue Activities

Over the past decade, for the purpose of managing the phenomenon of migration by sea, a wide number of different measures have been adopted by the European Union and its Member States. Notwithstanding the persistent need and the legal obligation to save people's lives at sea, Europe remains stocked on the protection of the security of its internal and external borders and goes ahead with the launch of Eunavfor Med--Operation Sophia, the first naval mission aimed to disrupt the business model of migrant smuggling and human trafficking in the Mediterranean. The following chapter examines the factual and legal background behind the establishment of this military mission and focuses on two sensitive and interrelated aspects: the use of enforcement powers against alleged smugglers and traffickers on the one hand and the rescue of irregular migrants at sea on the other hand. While various challenges prevent the activation of the crucial military phase of Operation Sophia, the operational and legal framework applicable to incidental search and rescue interventions carried out by its naval forces appears rather unclear and problematic under different perspectives of international law, especially if the Operation will continue into Libyan territorial waters in cooperation with its unstable authorities