Speciation Studies of Trace Metals in the Gulf of Elefsis, Greece

A method for differentiating trace metal species on the basis of relative lability has been applied for Pb, Cd, Zn, in microenvironments of the Gulf of Elefsis. Species are classified as »very labile«, »moderately labile«, »slowly labile« and »inert« depending on the characteristic time scale of the measuring technique using differential pulse anodic stripping voltammetry (DPASV) and the retention on Chelex-100 resin in successive column and batch procedures. The results show that in two extremely different microenvironments (with S of about 17%c and ~45%o) the slowly labile and inert fractions prevail particularly at the surface layer, whereas in the main water body of the gulf the very labile fraction is the predominant one. However at the thermocline and below it the »inert« fraction increases considerably paralleling, broadly, the particulate metal distributions

Fabrication and examination of oxidation resistance of zinc coated copper and brass components by chemical deposition

n this work, the structure and the oxidation resistance of Zn deposited Cu and brass metallic components are examined. The deposition was accomplished with pack cementation chemical deposition. The examination of the samples was performed with electron microscopy and X-ray diffraction analysis. It was found that coatings on Cu substrate consist of two layers with different Zn concentrations, while coatings on brass were single layered with almost constant Zn concentration. The presence of distinct Zn—Cu phases was revealed in both cases. The subjection of the as coated samples together with the uncoated substrates in air at 400ºC showed that both Zn coated samples have enhanced resistivity in such atmospheres, as most of the coating remained mostly unoxidised, and the substrates were fully protected. On the contrary, the bare substrates appear to have undergone severe damage as brittle oxides were formed on their surface.Publicad

Factors governing the deep ventilation of the Red Sea

Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 120 (2015): 7493–7505, doi:10.1002/2015JC010996.A variety of data based on hydrographic measurements, satellite observations, reanalysis databases, and meteorological observations are used to explore the interannual variability and factors governing the deep water formation in the northern Red Sea. Historical and recent hydrographic data consistently indicate that the ventilation of the near-bottom layer in the Red Sea is a robust feature of the thermohaline circulation. Dense water capable to reach the bottom layers of the Red Sea can be regularly produced mostly inside the Gulfs of Aqaba and Suez. Occasionally, during colder than usual winters, deep water formation may also take place over coastal areas in the northernmost end of the open Red Sea just outside the Gulfs of Aqaba and Suez. However, the origin as well as the amount of deep waters exhibit considerable interannual variability depending not only on atmospheric forcing but also on the water circulation over the northern Red Sea. Analysis of several recent winters shows that the strength of the cyclonic gyre prevailing in the northernmost part of the basin can effectively influence the sea surface temperature (SST) and intensify or moderate the winter surface cooling. Upwelling associated with periods of persistent gyre circulation lowers the SST over the northernmost part of the Red Sea and can produce colder than normal winter SST even without extreme heat loss by the sea surface. In addition, the occasional persistence of the cyclonic gyre feeds the surface layers of the northern Red Sea with nutrients, considerably increasing the phytoplankton biomass.Saudi ARAMCO Marine Environmental Centre of King Abdullah University of Science and Technology (KAUST); Saudi Aramco Oil Co.2016-05-1

Implicit sequence learning is preserved in dyslexic children

This study investigates the implicit sequence learning abilities of dyslexic children using an artificial grammar learning task with an extended exposure period. Twenty children with developmental dyslexia participated in the study and were matched with two control groups-one matched for age and other for reading skills. During 3 days, all participants performed an acquisition task, where they were exposed to colored geometrical forms sequences with an underlying grammatical structure. On the last day, after the acquisition task, participants were tested in a grammaticality classification task. Implicit sequence learning was present in dyslexic children, as well as in both control groups, and no differences between groups were observed. These results suggest that implicit learning deficits per se cannot explain the characteristic reading difficulties of the dyslexics.info:eu-repo/semantics/publishedVersio

Occurrence and spatial distribution of 158 pharmaceuticals, drug of abuse and related metabolites in offshore seawater

The occurrence and spatial distribution of 158 pharmaceuticals and drugs of abuse were studied in seawater of the Eastern Mediterranean Sea (Saronikos Gulf and Elefsis Bay in central Aegean Sea). This area is affected by various anthropogenic pressures as it receives the treated wastewater of the greatest Athens area and off-shore input fluxes. This study constitutes the largest one in terms of number of analytes in this environmental compartment. It provides the first evidence on the occurrence of several pharmaceuticals in marine environment including amoxicillin, lidocaine, citalopram or tramadol, among others. 22 samples were collected at three different depths in 9 sampling stations in order to assess the presence and the spatial distribution of the target compounds. A multi-residue method based on solid phase extraction and liquid chromatography coupled to tandem mass spectrometry was developed for the determination of the 158 target substances and validated for seawater sample analysis. 38 out of the 158 target compounds were detected, 15 of them with frequencies of detection equal to or higher than 50%. The highest detected values corresponded to amoxicillin, caffeine and salicylic acid, with concentrations in the range of < 5.0–127.8 ng L− 1; 5.2–78.2 ng L− 1 and < 0.4–53.3 ng L− 1, respectively. Inputs from the wastewater treatment plant (WWTP) of Athens revealed to be the main source of pollution in the Inner Saronikos Gulf, whereas, other anthropogenic pressures such as contamination from shipping activity, industrial effluents, dredging and/or inputs from land proved to be also relevant. Τhe concentrations of some compounds varied significantly with depth suggesting that currents play an important role in the dilution of the target compounds

Editorial. A supplement of Scires-it on the COCONET european project

The Supplement to vol. 6, 2016 of SCIRES-IT contains the result of CoCoNet (Towards COast to COast NETworks of marine protected areas, coupled with sea-based wind energy potential), a project of the EU Oceans of Tomorrow programme (http://www.coconet-fp7.eu). The European Union requires Open Access to the results of the projects resulting from its support to scientific advancement. This is in full accordance with the policy of SCIRES-IT, an eco-sustainable open–access journal, which joins the main principles of the Berlin Declaration on Open Access with the aims of the International Convention on Biological Diversity. CoCoNet tackled two problems that are closely linked with each other: the protection of the marine environment and clean energy production. Hence, the Supplement is divided into two parts that, together, form a unicum