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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.

2025

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Sammendrag

Deep understanding of the structural composition and growth of biological specimens is becoming increasingly important for the development of bio-based and sustainable material systems. Full-field nano-computed tomography is particularly suitable for this purpose as it allows for non-destructive 3D imaging at high spatial resolution. However, most biological samples are functionalized by water and respond sensitively to any changes in climate conditions, specifically relative humidity, by adjusting their material moisture content. To date, only a limited number of tomography instruments offer an in situ climate control option to users. These, however, are limited either by the range of relative humidity states, the long times required to change the climate state, or obstruction or attenuation of the beam. Here, the first fully automatized climate cell for in situ full-field nanotomography is presented. It has been designed, built and integrated at the nanotomography station at the P05 imaging beamline, operated by Hereon at the DESY storage ring PETRA III, Germany. The highly flexible and windowless design allows the humidity dependent swelling and shrinking of lignified plant cell walls to be studied in situ, using phase contrast nanotomography. The concept of this climate chamber can easily be integrated into other setups. It operates in the relative humidity range of 0–90% and can be controlled in a temperature range of 10–50°C. Climate conditions can be adjusted at any time, remotely from the control hutch by using a humidity generator. Results show that the developed setup maintains a stable climate during the entire duration of a tomographic scan at different humidities and does not obstruct the sample or hinder the imaging conditions. During the tomographic investigation the sample remains stable in the flow of the air stream and shows typical cell wall swelling and shrinking behaviour depending on the equilibrium moisture content. This new climate cell is now available to all users of the P05 nanotomography instrument for conditioning samples, serving a wide range of scientific applications.

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Sammendrag

Many studies that use an automated sorption balance to determine a water vapor sorption isotherm for wood collect data until the moisture content change is less than or equal to 0.002% min −1 (20 µg g −1 min −1 ). This stop criterion has been claimed to give errors in equilibrium moisture content (EMC) predictions of less than 0.001 g g −1 but over the past 10 years, studies have shown that the actual errors can be greater than 0.01 g g −1 because the measurements are stopped well before equilibrium is reached. Despite the large errors associated with this stop criterion, it remains popular due to the speed at which isotherms can be measured. This paper utilizes data from a worldwide interlaboratory study on automated sorption balances to develop a correction method for estimating EMC of western larch ( Larix occidentalis Nutt.) from the moisture content corresponding to the 20 µg g −1 min −1 criterion. The study uses data from 72 relative humidity absorption steps with hold times of 7–10 days from 21 different laboratories and eight different instrument models. EMC is defined based on the inherent mass stability of automated sorption balances determined in the first part of this interlaboratory study. On average the sorption process is less than 80% complete when the 20 µg g −1 min −1 criterion is reached, resulting in a mean absolute error (MAE) of 0.006 g g −1 . The correction equation for estimating EMC reduces the MAE to 0.001 g g −1 . The analysis presented in this paper, along with the correction equation, can be considered for certain use cases to reduce systematic errors and shorten measurement times.

Sammendrag

NIBIOs treteknologer ønsker å utnytte restråstoff fra treindustrien til å lage PhosBoard: Miljøvennlige trefiberplater som både er lette, isolerende og hemmer brann.

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A survey including 3112 responses from individual end users of wood cladding, from Norway, Sweden and Germany, was conducted with questions related to their experience and preferences regarding cladding with and without coatings. Based on these results and established scientific understanding of Service Life Prediction (SLP) of wood cladding, two decision trees were provided to guide end users in selecting a suitable material to meet their expectations when planning a new cladding. This approach makes the users reflect on maintenance requirements and aesthetic changes rather than choosing a product solely based on initial aesthetic appeal.

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Sammendrag

To optimise the use of renewable materials in construction, it is essential to understand the factors influencing decisions throughout their design and service life. Life Cycle Costing (LCC) supports sustainable development by aiming to minimise long-term costs through informed planning of service life, maintenance, and replacement. Central to this is the engineering concept of limit states - Ultimate Limit States (ULS) for structural safety and Serviceability Limit States (SLS) for functionality. However, in non-loadbearing applications such as cladding, maintenance is often driven by aesthetic deterioration rather than structural concerns. These aesthetic limit states are subjective and influenced by user preferences, personality traits, and cultural background. In practice, undesired aesthetic changes are among the main reasons for cladding replacement in Europe, alongside fungal decay and modernisation. Premature replacement due to insufficient communication about weathering effects and maintenance needs remains under-addressed. By accounting for variation in user preferences, material selection can be tailored to support a longer service life. This study presents multi-country variation in climate-related perceptions of wood and user preferences for wooden cladding.

Sammendrag

A total of 212 iconic wooden cable car pylons were constructed for mining operations in Svalbard, significantly contributing to Longyearbyen's historical identity as a mining town. Fieldwork in Svalbard involved collecting wood samples from 22 of these pylons, targeting wood exposed both aboveground and ground proximity. While the timber used in the constructions was assumed to be untreated Norway spruce (Picea abies), light microscopy revealed that 25% of the timber members were Scots pine (Pinus sylvestris). Wooden beams exposed aboveground showed initial decay over the first 80-90 years, whereas severe fungal decay was observed after about 50 years in wooden poles inserted in the ground. Metabarcoding identified Ascomycetes and Basidiomycetes to be predominating in the wood samples and unveiled new fungal species for Svalbard, including four brown rot, five white rot, and sixteen soft rot species. Macroscopic and microscopic examinations confirmed more advanced decay in ground proximity samples, dominated by brown and soft rot fungi.