Effect of plasma sizing on basalt fibers adhesion with wood-working resins

European Journal of Wood and Wood Products - Basalt fabric with manufacturer-made silane sizing was additionally treated by propane-butane enriched atmospheric pressure nitrogen plasma for 15 and...     

Export of arsenic from forested catchments under easing atmospheric pollution

Massive lignite burning in Central European power plants peaked in the 1980s. Dissolved arsenic in runoff from upland forest ecosystems is one of the ecotoxicological risks resulting from power plant emissions. Maxima in As concentrations in runoff from four forest catchments have increased 2-5 times between 1995 and 2006, and approach the drinking water limit (10 microg L(-1)). To assess the fate of anthropogenic As, we constructed input/output mass balances for three polluted and one relatively unpolluted forest catchment in the Czech Republic, and evaluated the pool size of soil As. The observation period was 11 years, and the sites spanned a 6-fold As pollution gradient. Two of the polluted sites exhibit large net As export via runoff solutes (mean of 4-5 g As ha(-1) yr(-1) for the 11-year period; up to 28 g As ha(-1) yr(-1) in 2005). This contrasts with previous studies which concluded that forest catchments are a net sink for atmogenic arsenic both at times of increasing and decreasing pollution. The amount of exported As is not correlated with the total As soil pool size, which is over 78% geogenic in origin, but correlates closely with water fluxes via runoff. Net arsenic release is caused by an interplay of hydrological conditions and retreating acidification which may mobilize arsenic by competitive ligand exchange. The effects of droughts and other aspects of climate change on subsequent As release from soil were not investigated. Between-site comparisons indicate that most pollutant As may be released from humus.     

Effect of catalyst composition on the selectivity of competitive hydrogenations of mono-olefinic reactants in the liquid state

The effect of the amount of platinum and the type of the carrier on the selectivity for competitive hydrogenation of 2-methyl-3-butene-2-ol and hex-l-ene in methanol on platinum carrier catalysts has been studied. The effect of the type of the active component and carrier on the selectivity for competitive hydrogenation of 2-methyl-3-butene-2-ol and 2-phenylpropene in methanol and cyclohexane on various types of catalyst has also been investigated. Selectivity decreased with increasing amounts of platinum on the carrier and also with decreasing polarity of the carrier. The change in selectivity was greatest for a change in the active (metal) component of the catalysts; being in most cases several times higher in cyclohexane compared with methanol.