Electrochemical Study of a SOFC with Various H 2 -CO-CH 4 -CO 2 -N 2 Gaseous Mixtures

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Effects of carbon monoxide, carbon dioxide, and methane on nickel/yttria-stabilized zirconia-based solid oxide fuel cells performance for direct coupling with a gasifier

International audienceThis work focuses on the role of CO and CO2 usually present in syngas generated by biomass gasification when they are flowed in a Ni-YSZ-based SOPC. Polarization, power versus intensity and electrochemical impedance spectroscopy measurements are performed and the theoretical aspect is enhanced with comparison with values of the Nernst potentials of the two H2O/H-2 and CO2/CO couples. The CO as electrochemical reactant is clearly highlighted, and also compared to H2. Indeed, power density values of 460 mW cm(-2) and 540 mW cm(-2) are obtained at 750 C when the cell is fueled with a 50% CO-50% N-2 mixture and a 50% H-2-50% N-2 mixture respectively, and the use of CO leads to higher power density values when the percentage of the fuel in the Fuel/N-2 mixture is lower than 27%, the use of higher amounts of CO inducing a large increase of the total resistance of the cell. The impact on the efficiency of the cell of the presence of CH4 is also examined using electrochemical measurements. Finally, power density values of 502 mW cm(-2) is obtained at 750 degrees C when the cell is fueled with a 50% N2-20% CO-17% H-2-10% CO2-3% CH4 mixture which appears to a be a realistic composition corresponding to the exhaust of the gasifier. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

Sucrose octasulfate dressing versus control dressing in patients with neuroischaemic diabetic foot ulcers (Explorer): an international, multicentre, double-blind, randomised, controlled trial

Diabetic foot ulcers are serious and challenging wounds associated with high risk of infection and lower-limb amputation. Ulcers are deemed neuroischaemic if peripheral neuropathy and peripheral artery disease are both present. No satisfactory treatment for neuroischaemic ulcers currently exists, and no evidence supports one particular dressing. We aimed to assess the effect of a sucrose octasulfate dressing versus a control dressing on wound closure in patients with neuroischaemic diabetic foot ulcers

Protease-modulating polyacrylate-based hydrogel stimulates wound bed preparation in venous leg ulcers - a randomized controlled trial

BackgroundStringent control of proteolytic activity represents a major therapeutic approach for wound-bed preparation. ObjectivesWe tested whether a protease-modulating polyacrylate- (PA-) containing hydrogel resulted in a more efficient wound-bed preparation of venous leg ulcers when compared to an amorphous hydrogel without known protease-modulating properties. MethodsPatients were randomized to the polyacrylate-based hydrogel (n=34) or to an amorphous hydrogel (n=41). Wound beds were evaluated by three blinded experts using photographs taken on days 0, 7 and 14. ResultsAfter 14 days of treatment there was an absolute decrease in fibrin and necrotic tissue of 37.629.9 percentage points in the PA-based hydrogel group and by 16.8 +/- 23.0 percentage points in the amorphous hydrogel group. The absolute increase in the proportion of ulcer area covered by granulation tissue was 36.0 +/- 27.4 percentage points in the PA-based hydrogel group and 14.5 +/- 22.0 percentage points in the control group. The differences between the groups were significant (decrease in fibrin and necrotic tissue P=0.004 and increase in granulation tissue P=0.0005, respectively). ConclusionIn particular, long-standing wounds profited from the treatment with the PA-based hydrogel. These data suggest that PA-based hydrogel dressings can stimulate normalization of the wound environment, particularly in hard-to-heal ulcers