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.
2007
Sammendrag
Furfurylated wood is an environmentally friendly, chemically treated, wood product with improved characteristics. Quality control of furfurylated wood is still performed manually by subtracting the initial weight of a treated sample from its final weight, then dividing the result by the initial weight. Expressed as a percentage, this results in a value that represents the weight percent gain (WPG) of the treated sample and thus the degree of modification. The major disadvantage of this quality control method is that the production parameters are needed to determine WPG, since the initial weight cannot be deduced from a treated wood sample. In this paper the use of ThermoGravimetric Analysis (TGA) is presented as a potential quality control method for furfurylated Scots pine (Pinus sylvestris L.). The technique is independent of production parameters and, therefore, enables third parties to determine the WPG of any furfurylated wood product. Three validation trials have been performed with the same validation samples, but varying TGA settings and with different Partial Least Square regression models (PLS-models). Although the method needs further improvement, it has shown good accuracy and precision. Therefore, it is con
Sammendrag
Furfurylated wood (wood modified by furfuryl alcohol) has over the last years gained marked shares from both tropical wood and conventional preservative treated wood and this has, in turn, generated several research projects concerning process development. The impregnation of spruce is well known from literature to be a difficult task. Furthermore, the sapwood of Scandinavian grown Scots pine is also known to be difficult to fully impregnate from time to time. The primary objective of the study was to evaluate whether the Oscillating Pressure Method (OPM) could be used to impregnate green and dry Norway spruce wood (Picea abies) with a Furfuryl alcohol (FA) - mixture. The secondary objective of the study was to evaluate if OPM could improve the penetration of FA in Scots pine (Pinus sylvestris) as compared to conventional full cell (Bethell) treatment. Impregnation tests were carried out on boards and planks as well as 300 mm and 500 mm clear wood samples. Samples were removed for MC measurement and the initial weight of the test samples was determined. Four different impregnation schemes were tested. The results indicate that Norway spruce can be impregnated by the OPM method to produce a protective shell of treated wood around a core of untreated wood. The penetration in Spruce showed great variation between different boards and between different parts of the individual boards. This is in part expected, but can also be caused by uncontrolled pre drying of the test material which was stacked uncovered after sawing. For Scots pine, the OPM improved the penetration of both sapwood and, to some extent, the outer heartwood.
Sammendrag
The objective was to evaluate whether Lowry-impregnation of Scots pine with FA100-mix, instead of the FA40-mix, would lead to similar or slightly higher WPGs and to investigate any potential changes in penetration pattern. The results indicate that the penetration was better, also penetrating the outer zone of the heartwood. Furthermore, it was possible to reduce the WPG-levels for pine down to 50-70% (corresponding to PFA retentions of 260- 315 kg/m³) from 120% (approx. 550 kg/m³) with full-cell impregnation using FA100-mix. Using the Lowry process with FA100-mix would probably be a possible treating schedule for products aimed for use in ground contact. The reduced content of hygroscopic salts in the furfurylated wood product would also further reduce hygroscopisity compared with FA-40 mix. However, more trials are needed in order to optimize penetration while still keeping the final WPG low.
Sammendrag
Trevinduers kvalitet og levetid er avhengig av en rekke faktorer. Kvalitet på trevirke er en slik faktor og utgangspunktet for all vindusproduksjon. En state of the art rapport fra Norsk institutt for skog og landskap belyser og diskuterer trekvalitet i et vindusperspektiv.
Forfattere
Svein EilertsenSammendrag
Det har vært gjennomført en del forebyggende tiltak mot tap av tamrein til rovdyr både i Norge og i Sverige. Det savnes en grundig gjennomgang av de ulike tiltakenes virkning på tap, kost-/nytteeffekt og konsekvenser for andre forhold innen reindrifta. Reindrifta er i større grad enn andre næringer påvirket av årstidsvariasjoner i bl.a. klima og rovviltforekomster. Driftsforhold og driftssystem varierer mye mellom de ulike reinbeitedistriktene i de ulke fylkene. Derfor kan også forebyggende tiltak ha ulik virkning i forskjellige distrikt. Gjennom et forskningsprosjekt ønsker Bioforsk Nord Tjøtta å utarbeide en oversikt over tiltakene som har vært prøvd, og virkningen av disse. Resultatene skal danne et grunnlag for å gi råd om aktuelle forebyggende tiltak i reindriftsnæringa ut fra tapssituasjon og driftsopplegg.
Forfattere
Svein EilertsenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
After two decades of monitoring forest health in Europe, in response to concern for negative effects of air pollution, a similar worry is now increasing in China. In a co-operative project between Chinese and Norwegian researchers a forest monitoring was implemented in the acid rain region in south China. During 2000–2004 two small watersheds were monitored: TieShanPing (TSP) near ChongQing City and LuChongGuan (LCG) near GuiYang City. They are covered by Masson pine (Pinus massoniana) forest. The methodology of the European intensive forest monitoring programme (ICP-Forests level-II) was adopted; including crown assessments, foliar chemistry, air and soil chemistry, and more. This paper presents results of this co-operative project. Considerable forest damage was revealed by monitoring the crown condition of Masson pine trees. The average defoliation percentage for all assessed trees (predominant, dominant and co-dominant pines, corresponding to Kraft classes 1–3) in the more acidified TSP was over 40% and remained stable throughout the monitoring period, accompanied by an extremely high mortality in some years. In contrast, the defoliation in the less acidified LCG was relatively low but increased considerably, from 16% to around 40%, within the 4 monitoring years. The significance of air pollution for the forest damage remains uncertain. The annual SO2 concentration in TSP and LCG is about 2 and 4 times higher than the critical level of 20 μg m−3 given in the LRTAP convention for effects on forests. Therefore the air pollution effects cannot be ruled out as contributing factors for forest damage. However, this cannot be substantiated based on the presented monitoring data since none of the specific symptoms of air pollution damage were observed. Furthermore, an analysis of the monitoring data did not reveal any significant correlation between defoliation and the soil chemical properties. It is noteworthy that the evident agents that were identified are capable of causing the observed forest damage. These agents were insect attacks and climatic stress. It is possible that the forest damage has complex causes.
Forfattere
Tor MykingSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor MykingSammendrag
Det er ikke registrert sammendrag