Teknologian Tutkimuskeskus VTT Oy

In this study, tall oil fatty acid ester of softwood kraft lignin (TOFA-L) was used to prepare TOFA lignin nanoparticles (TLNP) in water. The average diameters for two prepared TLNPs in 0.1 mg/ml concentration were 140 nm and 160 nm. TLNPs were attached covalently onto modified and unmodified cellulose fibres to form an antimicrobial composite material. The modified cellulose fibres contained reactive allylic double bonds with a degree of substitution of 0.05. The antimicrobial properties of both TLNPs and TLNP coated fibres (TLNP-C) were studied againstEscherichia coli,Staphylococcus aureusandPseudomonas aeruginosausing silver nanospheres (average size 10 nm) and Lignoboost lignin particles with 300 and 400 nm sizes as references. Antimicrobial activity of the samples was stronger against Gram-positiveS. aureuscells than against Gram-negative target microbesE. coliandP. aeruginosa.

Information about the reaction mechanisms of cellobioside hydrolases I and II (CBHI and CBHII) of T. reesei was obtained by examining their resp. products from hydrolysis of β-cellobiosyl fluoride.CBHI gives β-cellobiopyranose as its 1st products whereas CBHII gives α-cellobiopyranose.The catalytic mechanism of the 2 enzymes must therefore be radically different with CBHI acting through a glycosyl-enzyme intermediate, and CBHII probably using a single displacement by a nucleophilic H₂O mol.

Reactor physics of Na-cooled fast breeder reactors (LMFBR), computational methods, their applications and results are represented.Special aspects are design of reactor core and fuel, and reactor safety.Differences between LMFBR and LWR are emphasized in the description of reactor physics calculations