An accurate model for the determination of the kinetic coefficients of the copper-catalyzed oxidation of iodide by oxygen in an aqueous acidic medium.

The reaction rate of the copper-catalyzed oxidation of iodide by oxygen in an aqueous acidic medium is first order in copper and oxygen concentrations, Michaelis-Menten in pH and a complex, asymmetrical bell shaped function in iodide concentrations. A theoretical, multivariate reaction rate equation was proposed which enabled to optimise the various kinetic coefficients. During the parameter optimisation, the experiments were weighted taking into account all measurement uncertainties, i.

High-resolution time series of vessel density in Kenyan mangrove trees reveal a link with climate.

Tropical trees are often excluded from dendrochronological investigations because of a lack of distinct growth ring boundaries, causing a gap in paleoclimate reconstructions from tropical regions. The potential use of time series of vessel features (density, diameter, surface area and hydraulic conductivity) combined with spectral analysis as a proxy for environmental conditions in the mangrove Rhizophora mucronata was investigated. Intra-annual differences in the vessel features revealed a trade-off between hydraulic efficiency (large vessels) during the rainy season and hydraulic safety (small, more numerous vessels) during the dry season.

Correlations, partitioning and bioaccumulation of heavy metals between different compartments of Lake Balaton.

Correlations between trace metals in dissolved and particulate phases, zooplankton, mussels and sediments in Lake Balaton were investigated. The degree of correlation between the various metals was different in each of the investigated compartments. Particulate metal concentrations (microg g(-1)) were anti-correlated with suspended particulate matter (SPM) (mg l(-1)), indicating a dilution effect, while total metal concentrations in the water column (microg l(-1)) were highly correlated with SPM, implying a major influence of the turbidity on the total metal concentrations.