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.
1991
Authors
Torild Wickstrøm W. Lund R. ByeAbstract
Selenium is determined in copper and nickel materials without any interferences. Hydrochloric acid plus hydrogen peroxide are used to dissolve the samples. The solution is then made alkaline with sodium hydroxide in order to eliminate the interference from copper and nickel by precipitation of the corresponding hydroxides. Sodium tetrahydroborate is added to the alkaline solution in order to reduce selenium(IV) to the selenide ion, and the solution is then filtered. The volatile selenium hydride is generated by acidification of the alkaline solution in a continuous flow system. The method was used successfully for the determination of selenium in three standard reference materials (SRMs) from the National Institute of Standards and Technology: SRM 398 Unalloyed Copper V, SRM 671 Nickel Oxide 1 and SRM 875 Cupro-Nickel, 10 (CDA 706) (doped). The detection limit of the method was approximately 1-mu-g g-1.
Authors
O. Nilssen Carl Gunnar Fossdal K. Eian B.H. LindqvistAbstract
No abstract has been registered
Authors
Bjørn Langerud Martin SandvikAbstract
No abstract has been registered
Authors
Bjørn Langerud Martin SandvikAbstract
No abstract has been registered
Authors
Mette Goul ThomsenAbstract
No abstract has been registered
Authors
Oddvar SkreAbstract
Large differences were found in survival stratey among species and ecotypes. The maple and elm populations and the two southern birch populations all responded to high temperatures by rapid leaf expansion as a possible compensation for increased respiration loss, and themaple and birch also by increasing their stem elongation rates, thereby competing more efficiently for available light. In the northern subalpine birch population, however, the seedlings developed leaves with high net assimilation rates instead of increasing their leaf areas and stem elongation rates. In this population abiotic climatic factors rather than competition therefor seem to be the most important adaptive force.
Authors
Paal KrokeneAbstract
No abstract has been registered
Authors
Carl Gunnar Fossdal B.H. Lindqvist O. Marvik S. Rishovd Praveen SharmaAbstract
No abstract has been registered
Authors
Harald Kvaalen Sara von ArnoldAbstract
Effects of various partial pressures of oxygen (5, 20 and 45 kPa) and carbon dioxide (0.03 and 6 kPa) on initiation, proliferation and maturation of somatic embryos in Picea abies were studied. The pO2 had a significant effect on the initiation of embryogenic tissue from mature zygotic embryos. However, the effect of pO2 was dependent on the strength of the basal medium.Low pO2 stimulated the formation of embryogenic tissue when the zygotic embryos were incubated on full strength medium, but was inhibitory when half-strength medium was used.Proliferation of embryogenic tissue was stimulated by higher partial pressures of both CO2 and O2. The effect of the gas phase on maturation of somatic embryos varied between different cell lines. However, there was a general tendency for 5 kPa O2 and 6 kPa CO2 to stimulate maturation.
Authors
Bjørn Langerud Pasi Puttonen Erik TroengAbstract
No abstract has been registered