In recent decades. an exponential increase in the concentration of anthropogenic Polycyclic Aromatic Hydrocarbons (PAHs; see Table I for a li st of PAH abbreviations) has been observed worldwide. Regulators need to know the sources if concentrations are to be reduced and appropriate remediation measures taken. "Source characterization of PAHs" involves linking these contaminants to their source...

High-MgO (s 8.5 wt%), aphyric lavas erupted at various locations in the North Atlantic igneous province are utilized to characterize the nature of mantle melting during the formation of this province. Based on the observation that the Ni concentration in residual mantle olivine mostly falls in the range of 2000^3500 ppm, these high-MgO samples are corrected for olivine fractionation until the N...

The recent article by Hostettler et al. (1999) describes a source-dependent refractory PAH index, T/C [C26(R)+C27(S)-triaromatic steranes/1-methylchrysene], and uses that index to argue that coal is the dominant source of the natural petrogenic hydrocarbon background in the marine sediments of Prince William Sound (PWS), Alaska. However, our more complete sampling of potential sources from the ...

The Scheldt River system is located in northern France, Belgium and the Netherlands and includes a dense network of rivers, which contributed to the urban and industrial development in this area. Three sediment cores, collected in the Upper Scheldt River (Helkijn) and two of its tributaries (the Lys River at Wervik and the Espierre Canal), were analysed for n-alkanes and polycyclic aromatic hyd...

Fjords are recognized as hotspots of organic carbon (OC) burial in the coastal ocean. In fjords with glaciated catchments, glacier discharge carries large amounts suspended matter. This sedimentary load includes OC from bedrock and terrigenous sources (modern vegetation, peat, soil deposits), which is either buried fjord or remineralized during export, acting a potential source CO2 to atmospher...

In situ observations of the perovskite–CaIrO3 phase transition in MgSiO3 and in pyrolitic compositions were carried out using a laser-heated diamond anvil cell interfaced with a synchrotron radiation source. For pure MgSiO3, the phase boundary between the orthorhombic Mg-perovskite and CaIrO3-type phases in the temperature range of 1300–3100 K was determined to be P (GPa)=130 (F3)+0.0070 (F0.00...

Using atomic force microscopy in noncontact mode, we have imaged nanometer-size liquid droplets of KOH water solutions on the surfaces of highly oriented pyrolitic graphite and mica. On graphite the droplets prefer to be adsorbed on atomic step edges. Droplets on the same step tend to be evenly spaced and of similar size. The droplets can be manipulated by the atomic force microscopy tip allowi...