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Excess mortality among the elderly in 12 European countries, February and March...

In February and March 2012, excess deaths among the elderly have been observed in 12 European countries that carry out weekly monitoring of all-cause mortality. These preliminary data indicate that the impact of influenza in Europe differs from the recent pandemic and post-pandemic seasons. The current excess mortality among the elderly may be related to the return of influenza A(H3N2) virus, potentially with a...

GROWTH AND ENZYME PRODUCTION DURING CONTINUOUS CULTURES OF A HIGH AMYLASE-PRODU...

Growth and product formation by a selected variant of Aspergillus oryzae showing high alpha-amylase production was studied in continuous cultivations carried out at six different specific growth rates, using glucose as the growth-limiting nutrient. The analysis of the steady-state data revealed that the variant and wild-type strains were similar with respect to glucose uptake system and stoichiometric coefficie...

Carbon formation on nickel and nickel-copper alloy catalysts

Equilibrium, kinetic and morphological studies of carbon formation in CH4+H2, CO, and CO+H2 gases on silica supported nickel and nickel-copper catalysts are reviewed. The equilibrium deviates in all cases from graphite equilibrium and more so in CO+CO2 than in CH4+H2. A kinetic model based on information from surface science results with chemisorption of CH4 and possibly also the first dehydrogenation step as r...

Carbon formation and CO methanation on silica-supported nickel and nickel–coppe...

The steady-state rates of simultaneous carbon formation and methanation on silica-supported nickel and nickel-copper catalysts in CO + H 2 gas mixtures have been measured in the partial pressure range 10-30 kPa and the temperature range 583-873 K. The steady-state kinetic results for carbon formation can be explained by a model previously used for carbon formation in pure CO gas, but modified to take into accou...

CO disproportionation on silica-supported Nickel and nickel-copper catalysts

The carbon formation/gasification equilibrium on silica-supported nickel and nickel-copper catalysts in CO + CO2 gas mixtures and the steady state kinetics of carbon formation from CO on the same catalysts were studied in a thermogravimetric flow system. The equilibrium gas composition was found to be the same for the nickel and the nickel-copper catalysts except at the highest copper concentrations (≥25 at.%),...

Actividade e desactivação de catalisadores Ni-Cu/SiO2 : avaliação da estabilida...

O presente trabalho relata o estudo da deposição de carbono em catalisadores de niquel-cobre suportados em sílica, a partir de misturas de CH4+H2 e CO+CO2 com diferentes composições e a diferentes temperaturas. Verifica-se que a diminuição da velocidade de deposição de carbono nas ligas (normalizada pela velocidade de deposição no niquel puro) não é significativamente afectada nem pela natureza, nem pela concen...

Reactivity of carbon deposited on nickel-copper alloy catalysts from the decomp...