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.
1995
Authors
Torild Wickstrøm W. Lund R. ByeAbstract
Selenium was determined in nickel and steel alloys by hydride generation in combination with both atomic absorption spectrometry (AAS) (heated quartz tube) and inductively coupled plasma atomic emission spectrometry (ICP-AES).A serious depression of the Se signal was observed when AAS was used for the determination, although the interference from Ni, Co, Cr, Fe and Cu was effectively masked with complexing agents. The depression was reduced when ICP-AES was used instead of AAS, indicating a gaseous phase interference.The interference may be caused by the presence of hydrides of Sn and As. For the determination of Se in nickel alloys and low-alloy steels, the detection limit was lowered by a factor 1.5-3 when ICP-AES was used instead of AAS. Several standard reference materials (nickel alloys and low-alloy steels) were analysed for Se.
Authors
Erik ChristiansenAbstract
No abstract has been registered
Authors
Erik Christiansen Alan A. BerrymanAbstract
No abstract has been registered
Authors
Kåre Olav VennAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Anders Göransson Toril Drabløs EldhusetAbstract
The effects of aluminium on plant nutrition in small birch plants (Betula pendula Roth) were investigated. By using relative addition rate (r A, g g-1 d-1) of nutrients as the growth-controlling variable, it was possible to grow the plants at very low external nutrient concentrations and to simulate plant requirements at two different fertility levels.Before aluminium addition the plants were at steady-state relative growth rate, (R G, g g-1 d-1). The two addition rates were free access of nutrients with RG 0.215 d-1, or nutrient-limited, RA and R G= 0.10 d-1.Internal concentrations of calcium and magnesium decreased with increasing Al3 conncentration in the nutrient solution while nitrogen concentrations in the plants remained unchanged or increased. It was demonstrated in both nutrition treatments that calcium and magnesium decrease per se does not reduce plant growth and that uptake has to be considered in relation to plant requirement at different growth rates. The interpretation of the effects of aluminium on Ca and Mg uptake and plant biomass development suggested that processes other than disturbances in Ca and Mg uptake are the cause of the decrease in growth.
Authors
Dan AamlidAbstract
No abstract has been registered
Authors
Bjørn ØklandAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Franck Brignolas B. Lacroix François Lieutier Daniel Sauvard A. Drouet A.C. Claudot A. Yart Alan A. Berryman Erik ChristiansenAbstract
Two Norway spruce (Picea abies Karst.) clones, one resistant and the other susceptible to mass inoculation with Ophiostoma polonicum Siem., were compared with regard to their phenolic compositions and chalcone synthase (CHS) and stilbene synthase activities of their phloem before and at 6 and 12 d after artificial inoculation with sterile malt agar or O. polonicum. In unwounded phloem, the resistant clone differed from the susceptible clone by the presence of taxifolin glycoside, lower concentrations of stilbene glycosides, and higher CHS activity. After inoculation, ()-catechin concentration and CHS activity dramatically increased around the wound, particularly in the resistant clone. Stilbene synthase activity also increased, but more slowly and to a lower level, whereas the concentrations of stilbenes remained stable. Tanning ability decreased in the susceptible done, whereas it remained stable in the resistant one. It is proposed that the induced phenolic response of Norway spruce phloem consists of an activation of the phenolic pathway, finally leading to tannins and insoluble polymers. It is suggested that resistance to O. polonicum depends on the ability of the tree to easily activate the flavonoid pathway.