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A two-step protocol including an enantioselective organocatalyzed synthesis of pyrroloquinolines followed by an oxidation reaction allowed the formation of axially chiral 2-aryl-pyrroloquinolones. Thorough optimization of the experimental conditions for the second step allowed the oxygenation reaction to take place and ensured, in most cases, a central-to-axial chirality conversion with complete retention of the enantiomeric excess.

Fluoroalkylselenotoluenesulfonates, which have already been described as selenolating reagents in electrophilic and radical reactions, can also be reduced by an organic electron donor (namely tetrakis(dimethylamino) ethylene or TDAE) to generate the corresponding fluoroalkylselenolate anions. Thus, the in‐situ‐formed anions react with various alkyl halides in a metal‐free nucleophilic substitution. Trifluoromethyl‐ and higher perfluroalkylselenolated compounds have been obtained in modest to good yields. One reagent, 3 faces! Fluoroalkylselenosulfonates are very versatile reagents. After a previously demonstrated electrophilic and radical reactivity, a nucleophilic fluoroalkylselenolation has been reported. Through a metal‐free process, the generation of anionic species, induced by an organic electron donor, can be performed.

Process of accelerated cooling of steel plates is under consideration. Control algorithm is developed taking into account temperature distribution wihin plate thickness and essential temperature dependence of the coefficients in the motion equation. The proposed control approach provides precise average temperature tracking in complete information case. The method is based on ordinary differential equation describing the dynamics of the scalar variable under control. For the reallife situation with entry and exit surface temperature measurements and uncertain plant parameters the developed method implies application of distributed state observer associated with adaptation loop.

Material balance has been used to evaluate the COD behaviour and the time required for fed-batch digestion of mixtures of domestic sludges and pre-hydrolysed agricultural wastes. Pre-hydrolysis of the feed materials has been used to penetrate the strong lignocellulosic structure of these wastes as well as to increase the fraction of soluble organic substances in the mixture. The influence of the organic loading rate on the main process parameters (methane, carbon dioxide, total biogas productions and their respective conversion yields) has also been investigated. The organic load has been varied from 0·8 up to 6·1 gCOD dm^-3 day^-1, corresponding to a range of volatile solids load of 0·6–4·5 gVS dm^-3 day^-1 for the material under consideration. These values are slightly higher than those usually employed in conventional digester for domestic sewage sludges. However, methane production reached a maximum rate of only 5·6 mmol dm^-3 day^-1 at an organic loading rate of 4·6 gCOD dm^-3 day^-1, while both CH4 content and production of biogas rapidly fell over 2·2 gCOD dm^-3 day^-1. On the whole, these results suggest that removal of lignin is necessary in order to carry out the continuous anaerobic digestion of pre-hydrolysed agricultural wastes rich in woody materials. © 1997 SCI.

The possible correlation between HLA system and liver cirrhosis secondary to HBV infection has been studied in 102 hospitalized elderly patients affected by liver cirrhosis (histologically proven) and 749 elderly health controls. Increased frequencies of HLA-A2, Cw4, Cw5, DR4, DR5 and DR7 have been observed in patients with liver cirrhosis and previous HBV infection, while a lower frequency of HLA-A2 and higher frequencies of HLA-A3, B35, Cw4, DR3 have been observed in patients without previous HBV infection when compared with controls.

The corrosion behaviour of mild steel in 3·5%NaCl solutions at pH 6 with initial dissolved oxygen contents of 6·5 ppm, containing 0·5, 1·1, or 2·7 mmol L−1additions of the silane coupling agent 3-(trimethoxysilyl)propanethiol-(1), has been studied at 25°C. Electrochemical polarisation tests, weight loss measurements, and surface analyses of the corrosion layers were carried out. It was found that the coupling agent, which is known to be an adhesion promoter, acts by inhibiting anodic and cathodic processes, providing reductions in corrosion rate of up to 60%.