Shallow-water hydrothermal venting linked to the Palaeocene–Eocene Thermal Maximum

The Palaeocene–Eocene Thermal Maximum (PETM) was a global warming event of 5–6 °C around 56 million years ago caused by input of carbon into the ocean and atmosphere. Hydrothermal venting of greenhouse gases produced in contact aureoles surrounding magmatic intrusions in the North Atlantic Igneous Province have been proposed to play a key role in the PETM carbon-cycle perturbation, but the precise timing, magnitude and climatic impact of such venting remains uncertain. Here we present seismic data and the results of a five-borehole transect sampling the crater of a hydrothermal vent complex in the Northeast Atlantic. Stable carbon isotope stratigraphy and dinoflagellate cyst biostratigraphy reveal a negative carbon isotope excursion coincident with the appearance of the index taxon Apectodinium augustum in the vent crater, firmly tying the infill to the PETM. The shape of the crater and stratified sediments suggests large-scale explosive gas release during the initial phase of vent formation followed by rapid, but largely undisturbed, diatomite-rich infill. Moreover, we show that these vents erupted in very shallow water across the North Atlantic Igneous Province, such that volatile emissions would have entered the atmosphere almost directly without oxidation to CO2 and at the onset of the PETM

Shallow-water hydrothermal venting linked to the Palaeocene–Eocene Thermal Maximum

The Palaeocene–Eocene Thermal Maximum (PETM) was a global warming event of 5–6 °C around 56 million years ago caused by input of carbon into the ocean and atmosphere. Hydrothermal venting of greenhouse gases produced in contact aureoles surrounding magmatic intrusions in the North Atlantic Igneous Province have been proposed to play a key role in the PETM carbon-cycle perturbation, but the precise timing, magnitude and climatic impact of such venting remains uncertain. Here we present seismic data and the results of a five-borehole transect sampling the crater of a hydrothermal vent complex in the Northeast Atlantic. Stable carbon isotope stratigraphy and dinoflagellate cyst biostratigraphy reveal a negative carbon isotope excursion coincident with the appearance of the index taxon Apectodinium augustum in the vent crater, firmly tying the infill to the PETM. The shape of the crater and stratified sediments suggests large-scale explosive gas release during the initial phase of vent formation followed by rapid, but largely undisturbed, diatomite-rich infill. Moreover, we show that these vents erupted in very shallow water across the North Atlantic Igneous Province, such that volatile emissions would have entered the atmosphere almost directly without oxidation to CO2 and at the onset of the PETM

Electrochemical oxidation of ethanol on thin coating of platinum based material on nickel support

1144-1152For the development of cost effective direct alcohol fuel cells, the key point for anodic oxidation of ethanol is the search for a cheaper electrocatalyst which can effectively increase the current density and decrease the anodic overvoltage. In this respect, thin deposits of platinum and co-deposits of platinum and ruthenium on Ni- support from different baths, have been studied taking 1M ethanol in 1M NaOH solution. Polarization and chronopotenti ometric studies indicate the intrinsic superiority of Ni/Pt-Ru electrodes over Ni/Pt and Ni electrodes, but the overall electrocatalytic activity of the coated electrodes follows the order: Ni/Pt (PVA) > Ni/Pt > Ni/Pt-Ru(PVA) > Ni/Pt -Ru > Ni, (where PVA is polyvinyl alcohol). An increase in the roughness factor due to smaller size (150nm ) of deposit of Pt than co-deposit of Pt and Ru under the experimemal deposition condition may be the cause of the above mentioned order. Steady state polarization, cyclic voltammetry, chromopotentiometry and SEM images have been used to correlate the catalytic activity of such electrodes with the characteristics of the deposits and surface morphology

NEEDLE FREE MONITORING OF BLOOD GLUCOSE THROUGH REVERSE IONTOPHORESIS

The frequent blood glucose monitoring is highly critical in order to understand the progression of diabetes mellitus and to minimize the probabilities of associated complications. This focuses to the fabrication of a new device for individual blood glucose monitoring. However, this technology turned out to be painful owing to its finger-stick technique, resulting in compromised patient compliance and inconsistent results. A paradigm shift from invasive to non-invasive technique to combat the above-stated limitations became an attractive tool for the researchers. The evolution of reverse iontophoresis to extract the essential plasma biomarkers as well as blood glucose through the skin was the result of the extensive efforts of the researchers as a means to monitor the blood glucose levels. The technology utilises delivery of small amount of electric current through the skin to extract the target molecules. This concept has received tremendous attention in the past decade; however, the technology still needs stringent validation for widespread implementation. Thus, in the present review, we aimed to elaborate the underlying mechanism of the reverse iontophoresis technique in the evaluation of blood glucose levels through skin, its unique features and its advancements towards commercialisation, the challenges faced, additional applications and the future prospects. The review also updates about the other non-invasive glucose monitoring techniques in comparison to reverse iontophoresis

Size-fraction-specific stable isotope variations in early Eocene bulk sediment carbon isotope records of ODP Site 198-1209

Here we present changes in abundances and δ13C and δ18O composition of five size fractions of bulk sediments from ODP Site 1209 in Shatsky Rise, north-central Pacific, deposited BETWEEN 58-50 Ma. The dataset includes four tables. The bulk sediments were rinsed and segregated into five size fractions: 250 μm. The difference in mass of sediments before and after size-fraction separation is reported in the first sheet. The second sheet documents temporal changes in relative weights of the various size fractions: namely fine fraction (FF), intermediate fraction (IF), coarse fraction (CF) and the three sub-fractions of CF. The δ13C and δ18O composition of bulk sediments and size fractions are reported in the third and fourth sheets, respectively