Ten Essential Oils for Beech Wood Protection - Efficacy Against Wood-destroying Fungi and Moulds, and Effect on Wood Discoloration
This work analyses the anti-fungal efficacy and stability of 10 essential oils, as well as their colour stability, in wood. The efficacy of oils against the decay fungi Coniophora puteana and Trametes versicolor as well as the moulds Aspergillus niger and Penicillium brevicompactum was evaluated first on filter papers treated with 1, 3.5, 10%, or 100% concentrate, and then on beech wood treated with 10% solutions. Accelerated ageing of treated beech samples was done before mycological tests and consisted of heating, leaching followed by heating, and Xenotest followed by heating. The highest growth inhibition of moulds and C. puteana was caused by thyme, oregano, sweet flag, and clove oils, while the savory and birch oils were less effective. These oils are potentially useful for wood protection against brown-rot fungi and moulds, mostly in interior conditions. The essential oils had only a negligible effect against the white-rot fungus T. versicolor, which was more apparent after previous ageing of wood. Some essential oils with a yellow tone (birch, oregano, sweet flag, savory, and tea tree oils) significantly changed (p<0.05) the natural colour of beech wood, but the new colours were relatively stable and underwent only mild changes after accelerated ageing in Xenotest.
Immobilization of laccase onto poly(glycidylmethacrylate) brush grafted poly(hydroxyethylmethacrylate) films: Enzymatic oxidation of phenolic compounds
Abstract Poly(hydroxyethylmethacrylate), p(HEMA) films were prepared via UV-initiated photo-polymerization. After activation of the hydroxyl groups of p(HEMA) by bromination, surface-initiated atom transfer radical polymerization (ATRP) of glycidylmethacrylate was conducted in dioxane/bipyridine mixture with CuBr as catalyst at 65 °C. The epoxy groups of the poly(glycidylmethacrylate) brushes were converted into amino groups with the reaction of ammonia. The modified p(HEMA-g-GMA)-NH2 films were used as an ion-exchange support for the immobilization of laccase. The influence of pH and initial laccase concentration on the immobilization capacity of the p(HEMA-g-GMA)-NH2 films has been investigated. The amount of immobilized laccase on the p(HEMA-g-GMA)-NH2 films was determined as 139 μg/cm2 films. The recovered activity of the immobilized laccase on the fibrous polymer grafted films was about 71% compared to free enzyme. The maximum activity (Vmax) and Michealis constant (Km) of laccase immobilized on the films, were found to be 15.4 U/mg and 23 mM, respectively. Finally, the immobilized laccase was operated in a batch system for enzymatic oxidation of phenol, p-chlorophenol and aniline.
Metallurgical Process Engineering
The "material of choice" - steel.- Uprising of China's steel industry.- Process manufacturing industry and process engineering.- Engineering science in steel manufacturing process.- Analysis and integration of metallurgical manufacturing process.- Multi-dimensional mass flow control for metallurgical manufacturing process.- Time factors in steel manufacturing process.-Operating dynamics in the production process of steel plant.- Structure and mode of steel plant.- Steel plant and environment.