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.
2003
Authors
Roger A. SedjoAbstract
No abstract has been registered
Authors
Peder GjerdrumAbstract
Artikkelen omhandler forsøksopplegg og reslultater av forsøk med 1) små feilfri prøver tørket ved temperaturer 30 - 60 - 90 - 120 grader og 2) prøver av varierende lengde/kvalitet av vanlig, industrielt fremstilt trelast av gran. For trelast tørket ved temperatur opp til 60-75 grader er det liten endring av likevektsfuktigheten (LVF) og i hysterese, med økende effekt for høyere tørketemperatur. LVF ble funnet å øke proporsjonalt med logaritmen av prøvens lengde, og slik at prøver med kvist mv. har 0.4 %-enh. lavere LVF enn feilfri prøver av samme lengde. Også hysteresis øket med økende lengde. Ettersom bare en begrenset del av området for faktorer som påvirker LVF og hysterese er undersøkt, bør undersøkelsene fortsette.
Authors
Per Otto Flæte Erlend Ystrøm HaartveitAbstract
For manufacturing of naturally durable products of Scots pine it is crucial to separate heartwood from the non-durable sapwood. The objectives of this study were to evaluate near infrared (NIR) spectroscopy as a non-destructive method for classifying heartwood and sapwood in Scots pine sawn wood, and to evaluate the applicability of NIR-spectroscopy in predictions of heartwood resistance to decay. Wood durability is measured by mass loss from fungal activity in a laboratory experiment.Using NIR-spectra in fully cross-validated partial least squares (PLS1) regression models, results show that it is possible to correctly classify samples of heartwood and sapwood. The results further demonstrate that resistance to decay in Scots pine heartwood and sapwood can be modelled with satisfying precision using NIR-spectroscopy. Within-tree variation in heartwood resistance to decay show the importance of building reliable models for identification of highly decay resistant heartwood, to accomplish a purposeful utilisation of naturally durable heartwood.
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No abstract has been registered
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No abstract has been registered
Authors
Inge Stupak Møller Staffan JacobsonAbstract
No abstract has been registered
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No abstract has been registered
– Bumblebee foraging - is closer really better?
Wenche E. Dramstad, Gary L.A. Fry, Marie J. Schaffer
Authors
Wenche E. Dramstad Gary L.A. Fry Marie J. SchafferAbstract
Bumblebees are important pollinators of crops and wild flowers, and their foraging range has considerable management interest. It is commonly assumed that bumblebees prefer to forage as close to their nest as possible. However, a review of the literature shows that there is little empirical evidence to support this assumption. An experiment aimed at investigating whether bumblebee workers forage close to their nests, and distances between three commercially produced bumblebee nests and an introduced forage patch were manipulated. The results presented here show that bumblebee workers significantly increased their use of a flower resource after their nests had been moved from within the resource to more than 100 m away.
Abstract
No abstract has been registered
Authors
Dominik Röser Antti Asikainen Simen Gjølsjø B. Jaskelevicius D. Johansson P. Jylhä L. Kairiukstis I. Konstantinova Jørn Kristian Lileng Anders Lunnan M. Mandre Juha Nurmi H. Pärn T. Saksa L. Sikanen Kjell Suadicani M. Totopainen L. VilkristeAbstract
The report is investigating the current state of forestry, forest industries and the bioenergy sector in Denmark, Estonia, Finland, Latvia, Lithuania, Norway and Sweden. The main task of the research is to illustrate the current supply and use of wood based fuels in the Baltic and Nordic countries. Additionally the present use of forest fuels in the different countries in the private and industrial sector is analyzed and bottlenecks in the current supply of forest fuels are identified. The focus on energy policy has been on energy systems with less CO2 emissions in order to meet requirement of international agreements. Therefore, forest fuels offer great potential as a source of renewable energy. There has been a steady increase in the growing stock of European forests. Large amounts of residues are left unutilised both in Nordic and Baltic forests, especially in first thinnings and intermediate cuttings. They offer large potential to further increase the share of wood fuels in total energy consumption. Forest industries utilize a great share of wood residues at present but especially in Baltic regions there is potential to intensify the use of wood residues. An additional increase in wood biomass utilization is also dependent on future expansion of the district heating networks in Nordic and Baltic countries. Potential is available especially in the Baltic countries and Norway. The situation in regards to utilization of wood biomass in private dwellings is similar in all seven countries. Large amounts of fuelwood are consumed annually but new furnace and burner technology is necessary to use resources more efficiently. In regards to energy policy a lot has been done to improve the use of biomass utilization, but more has to be done to strengthen the position of forest fuels in the future. The main bottlenecks for the larger use of forest biomass were found to be a lack of utilisation of available technology for harvesting and transport operations and a lack of district heating. An improved use of technology would decrease the price of forest fuels, necessary to compete with fossil fuel prices on international markets.