Exploring the Iron‐Binding Potential of the Ocean Using a Combined pH and DOC Parameterization

The major part of dissolved iron (DFe) in seawater is bound to organic matter, which prevents iron from adsorptive removal by sinking particles and essentially regulates the residence time of DFe and its availability for marine biota. Characteristics of iron‐binding ligands highly depend on their biological origin and physico‐chemical properties of seawater which may intensely alter under ongoing climate change. To understand environmental controls on the iron binding, we applied a function of pH and dissolved organic carbon (DOC) to describe changes in the binding strength of organic ligands in a global biogeochemical model (REcoM). This function was derived based on calculations using a thermodynamic chemical speciation model NICA. This parameterization considerably improved the modeled DFe distribution, particularly in the surface Pacific and the global mesopelagic and deep waters, compared to our previous model simulations with a constant ligand or one prognostic ligand. This indicates that the organic binding of iron is apparently controlled by seawater pH in addition to its link to organic matter. We tested further the response of this control to environmental changes in a simulation with future pH of a high emission scenario. The response of the binding potential shows a complex pattern in different regions and is regulated by factors that have opposite effects on the binding potential. The relative contributions of these factors can change over time by a continual change of environmental conditions. A dynamic feedback system therefore needs to be considered to predict the marine iron cycle under ongoing climate change

INTEGRATED DATING OF THE CONSTRUCTION AND RESTORATION OF THE MODENA CATHEDRAL VAULTS (NORTHERN ITALY): PRELIMINARY RESULTS

After the last damaging earthquake in 2012, an anti-seismic reinforcement project of the cathedral of Modena was designed giving us the opportunity to investigate and date the building materials. Radiocarbon (14C), optically stimulated luminescence (OSL), and thermoluminescence (TL) dating techniques were performed on the vaults with the aim to (1) clarify the construction timing, (2) define the history of the restorations, and (3) explore the possible correlation of the main restoration works to the earthquake chronology deduced from the historic catalog. Preliminary results show that medieval older bricks were reused for most of the original construction. Only lime and non-gypsum mortar was used for the original construction in the 15th century and for later repair of damage caused by earthquakes in the 16th and 17th centuries. Gypsum mortar was used for later repair in the 18th century. The results show much stronger damage due to earthquakes than previously thought

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

Sailing into a dilemma : an economic and legal analysis of an EU trading scheme for maritime emissions

On the basis of a joint economic and legal analysis, we evaluate the effects of a “regional” (European) emission trading scheme aiming at reducing emissions of international shipping. The focus lies on the question which share of emissions from maritime transport activities to and from the EU can and should be included in such a system. Our findings suggest that the attempt to implement an EU maritime ETS runs into a dilemma. It is not possible to design a system that achieves emission reductions in a cost efficient manner and is compatible with international law

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

Inductively coupled plasma mass spectrometric detection for multielement flow injection analysis and elemental speciation by reversed-phase liquid chromatography

The feasibility of using an inductively coupled plasma mass spectrometer as a muitieiement detector for flow injection analysis (FIA) and ion-pair reversed-phase liquid chromatography was investigated. Sample introduction was by uitrasonk nebulization with aerosol desolvation. Absolute detecton limits for FIA ranged from 0.01 to 0.1 ng for most elements using 10-pL injections. Over 30 elements were surveyed for their response to both anionic and cationic ion pairing reagents. The separation and selective detection of various As and Se species were demonstrated, yielding detection limits near 0.1 ng (as element) for ail six species present. Determination of 15 elements in a single injection with multiple ion monitoring produced shniiar detection limits. Isotope ratios were measured with sufficient precision (better than 2%) and accuracy (about 1 %) on eluting peaks of Cd and Pb to demonstrate that liquid chromatographyhductively coupled plasma mass spectrometry should make speciation studies with stable tracer isotopes feasible

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