Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2005
Authors
Peder GjerdrumAbstract
Det er stor variasjon i fiberforløp når man betrakter en hel trestamme. Således må den gjengse oppfatning om en regulær tredimensjonal anisotropi i stammen nyanseres. Såvel trevirkets fysiske egenskaper som fiberretningen har betydning når tre skal bearbeides og for egenskapene til den bearbeidede overflate. Denne presentasjonen omtaler varierende fiberretning knyttet til vridd vekst, kvister og overgangssonene rundt kvister, margens svakt slyngende form og uregelmessigheter i årringmønster og stokkens ytre form. Simultane modeller blir komplekse og mye av variasjonen forblir uforklart.
Abstract
Fungi cause serious problems in wood utilization, and environmentally benign wood protection is required as an alternative to traditional chemicals. Chitosan has shown promising antimicrobial properties against several microorganisms. In this study, we present the characterization of and antifungal properties of a commercial chitosan formulation developed for impregnation of wood.A broad range of chemical and mycological methods were used to evaluate the uptake, fixation, and antifungal properties of chitosan for wood preservation. The results show that the higher the uptake of chitosan the lower the relative recovery of chitosan in wood after leaching, and the higher the molecular weight of chitosan the higher the recovery.Chitosan with high molecular weight proved to be more efficient against decay fungi than chitosan with low molecular weight. The fungi tested on chitosan-amended nutrient agar medium were totally inhibited at 1% (w/v) concentration.In decay studies using small wood blocks, 4.8% (w/v) chitosan concentration gave the best protection against brown rot fungi.
Abstract
No abstract has been registered
Authors
Peder Gjerdrum Claudio Pollini Lorenzo ValentiAbstract
Wood is prone to natural decay. Unless properly conserved, sawlog quality will deteriorate due to checks, blue stain, rot wood borers and other causes. Log spraying has proved an efficient method for softwood quality preservation. The method is used both for seasonal storing during spring and summer, and for log preservation, e.g. following storm felling, for periods up to three years. A description of wood quality aspects and environmental impacts as well as practical and technical remedies are given.Most timber quality features will be upheld provided some basic routines are followed. Wood strength seems unaffected. Some discoloration due to tannin diffusion and spots of increased permeability due to bacterial colonies might be experienced. It is suggested that the method might be advantageous for the Italian Alpine forest industry.
Abstract
No abstract has been registered
Authors
Magnus Karlsson Ari M. Hietala Harald Kvaalen Åke Olson Halvor Solheim Jan Stenlid Carl Gunnar FossdalAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
This paper describes the use of quantitative real-time PCR for monitoring colonization of birch wood (Betula pubescens) by the white-rot fungus Trametes versicolor in an EN113 decay experiment. The wood samples were harvested after 4, 8, 12, 16 and 20 weeks of incubation.The mass loss was in the range of 440%. Chitin and ergosterol assays were conducted for comparison. Second-order polynomial fits of the mass loss of decayed wood versus chitin, ergosterol and DNA gave correlations (r2) of 0.87, 0.61 and 0.84, respectively. Compared to the other two assays employed, real-time PCR data correlated best with the relative mass loss of decayed samples 48 weeks after inoculation, while the saturation and decline of DNA-based estimates for fungal colonization 1620 weeks after inoculation indicated that the DNA assay is not suited for quantification purposes in the late stages of decay.The impact of conversion factors, extraction efficiency, inhibitory compounds and background levels in relation to the three detection assays used is discussed.
Authors
Lone Ross Gobakken Mats WestinAbstract
No abstract has been registered