Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2024
Sammendrag
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Sammendrag
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Sammendrag
The biological durability of ten wood species was determined on the basis of results from laboratory agar block tests. The experiment utilised two specimen formats: standard EN 113-2 specimens (15 × 25 × 50 mm) and mini-blocks (5 × 10 × 30 mm) exposed to two fungi (Coniophora puteana and Trametes versicolor) for varying incubation periods. Mini-block tests yield dissimilar outcomes compared to the European standard test at six, eight, ten or 16 weeks of incubation. This discrepancy extended to both durability classifications based on median percentage mass loss and those based on relative mass loss (x-values). It was therefore concluded that laboratory tests with miniaturised specimens are not advisable as a substitute for conventional durability classification assessments.
Sammendrag
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Sammendrag
The ability to identify locations that have a high risk of fungal decay is important for service life planning and analysing changes in risk can help inform scenarios where climate change may shift some areas into states that are more suitable for decay. The ERA5-Land database was used to obtain soil moisture and temperature data, which was applied in a dose–response model for in-ground wood decay. Dose was used as an indicator of decay risk and to produce hazard maps over Germany for the past two climate normals (1963–1992 and 1993–2022). There was an increase of 3.16 dose days over Germany. Brandenburg and Mecklenburg-Vorpommern, had the highest decay risk in both climate normals and southern states experienced the lowest decay risk. In Germany, larger dose increases were seen in central to southern latitude regions and mid to high altitudes. With further climate change, conditions that are most suitable for in-ground wood decay may shift to locations that previously did not experience such risk. It is important to be informed of the durability requirements of wood products in areas where increased resistance may be required.
Forfattere
Morten Rese Gijs van Erven Romy J. Veersma Gry Alfredsen Vincent Eijsink Mirjam A. Kabel Tina Rise TuvengSammendrag
Det er ikke registrert sammendrag
Forfattere
Morten Rese Gijs van Erven Romy J. Veersma Gry Alfredsen Vincent Eijsink Mirjam A. Kabel Tina Rise TuvengSammendrag
Det er ikke registrert sammendrag
Sammendrag
Extended Multiplicative Signal Correction (EMSC) is a multivariate linear modelling technique for multi-channel measurements that can identify and correct for different types of systematic variation patterns, known or unknown. It is typically used for pre-processing to separate light absorbance spectra, obtained by diffuse reflectance of intact samples, into three main sources of variation: additive variations due to chemical composition (≈Beer's law), mixed multiplicative and additive variations due to physical light scattering (≈Lambert's law) and more or less random measurement noise. The present work evaluates the use of EMSC to pre-process near infrared spectra obtained by hyperspectral imaging of Scots pine sapwood, inoculated with two different basidiomycete fungi and at various degradation stages. The spectral changes due to fungal decay and resulting mass loss are assessed by interpretation of the EMSC parameters and the partial least squares regression (PLSR) results. Including a cellulose (analyte) or bound water (interferent) spectral profile in the EMSC pre-processing model generally improves the predictive performance of the PLS modelling, but it can also make it worse. The inclusion of the additional polynomial baselines does not necessarily lead to a better separation of the physical and chemical effects present in the spectra. The estimated EMSC parameters provide insight into the differences in decay mechanisms. A detailed analysis of the EMSC results highlights advantages and disadvantages of using a complex pre-processing model.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Andrea Ponzecchi Gry Alfredsen Maria Fredriksson Emil Engelund Thybring Lisbeth G. ThygesenSammendrag
Acetylation is a commercialised chemical wood modification technology that increases the durability of wood against microbial attack. However, the details of how acetylation protects the wood structure from fungal degradation are still unclear. In this study, we tested the hypothesis that the resistance against microbial attack depends on the localisation of acetylation within the cell wall. The methodology involved two types of acetylation (uniform and lumen interface modification), which were analysed by lab-scale degradation with Rhodonia placenta, chitin quantification, infrared spectroscopy, and Raman microspectroscopy. The location of the acetylation did not affect overall mass loss during degradation experiments. Instead, the mass loss was related to the intensity of the treatment. However, chemical imaging of the interface acetylated specimens showed that degradation primarily took place in cell wall regions that were less acetylated. It was also observed that the fungus required more fungal biomass (i.e., fungal mycelia) to degrade acetylated wood than untreated wood. Based on dimensions and comparison to a reference spectrum, several cross-sections of hyphae located within lumina were discovered in the Raman images. These hyphae showed presence of chitin, water and chelated metals within their walls, and could be separated into an inner and an outer part based on their chemistry as seen in the spectra. The outer part was distinguished by a relatively higher amount of water and less chelated iron than the inner part.