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
Audun KorsæthAbstract
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Authors
Harald Kvaalen Ola Gram Dæhlen Anne Tove Rognstad Borgny Sveen Grønstad Ulrika EgertsdotterAbstract
Seeds of Abies lasiocarpa (Hook.) Nutt. (subalpine fir) were dissected, and the different parts were analyzed for elemental composition. The data were used to design a novel growth medium for initiation of somatic embryogenesis. Embryogenic cultures were initiated from immature zygotic embryos from six open-pollinated families of A. lasiocarpa on three different media.The frequency of initiation was the highest in early to mid-July when the zygotic embryo explants were ca. 0.8 mm long. Thereafter the response declined rapidly.The culture media did not significantly affect the initiation frequencies, but the subsequent growth and culture survival was dependent on the culture medium. On the Schenk Hildebrandt medium, many cultures ceased to grow and died. Several of the decaying cultures were rescued after transfer to one of the new media. Proliferating cultures could be stimulated to produce mature embryos. Of 2510 mature somatic embryos, 212 (8.4%) converted to plants, and 35 plants have grown over two periods.
Authors
Annbjørg Øverli Kristoffersen Mikkel Bakkegard Bernt HoelAbstract
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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.
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.
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Opportunities to make sequential decisions and adjust activities as a season progress and more information becomes available acharacterise the farm management process. ...
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Wood samples treated with ammonium copper quat (ACQ 1900 and ACQ 2200), chromated copper arsenate (CCA), Tanalith E 3491 and Wolmanit CX-8 have been studied in accelerated weathering experiments. The weathering experiment was performed by cycles of 2 h UV-light irradiation followed by water spray for 18 min. The changes on the surface of the weathered samples were characterized by roughness and color measurements on the samples with 0, 200, 400 and 600 h of total weathering.The objective of this study was to investigate the changes created by weathering on impregnated wood with several different wood preservatives. This study was performed on the accelerated weathering test cycle, using UVirradiation and water spray in order to simulate natural weathering. Surface roughness and color measurement was used to investigate the changes after several intervals (0200400600 h) in artificial weathering of treated and untreated wood.