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.
2000
Authors
Halvor B. Gjærum Mary Namaganda Kåre LyeAbstract
No abstract has been registered
Authors
Halvor B. Gjærum Mary Namaganda Kåre LyeAbstract
No abstract has been registered
Abstract
The present investigation deals with the properties of resonance wood destined for the production of musical instruments and with the methods for the determination of resonance wood quality. At the same time there are stated the range of values for the dynamic modulus of elasticity, for the speed of sound transmission and for the density of wood. The demands regarding dimension and growth characteristics of resonance wood are explained insisting first of all on pure subjective and visual criteria. The grading rules, existing only in a few regions in Germany, show that forestry is sensitized to this high value timber assortment only to a very small extent. With the Lucchimeter measuring method (elasticity tester) and the stress wave nondestructive evaluation technique spruce (Picea abies) and fir (Abies alba) wood panels are investigated which are destined for the production of guitars. The methods used as well as the results of measurement are compared with another. Furthermore the quantity of sales of resonance wood is presented after survey at the state owned forest management in Germany. The established small quantity of existing resonance wood is attributed to the sales of resonance wood not mentioned explicitly or described in detail. All in all the amount of resonance wood is supposed to be higher.
Authors
Tor MykingAbstract
No abstract has been registered
Authors
Sigmund Hågvar Einar EdsbergAbstract
No abstract has been registered
Authors
Gudbrand Lien Brian HardakerAbstract
No abstract has been registered
Authors
Michel VerheulAbstract
No abstract has been registered
Abstract
No abstract has been registered
1999
Authors
Leif AarvikAbstract
Beskrivelse av en ny art i en ny slekt i sommerfuglfamilien tussmørkesvermere. Arten er kjent fra Uzungwa-fjellene i Tanzania.
Authors
Gro HylenAbstract
Age trends of phenotypic, environmental, and additive genetic variance and heritability were estimated for overall density and its components earlywood and latewood densities and latewood proportion. The objective was to acquire information for both individual and cumulated rings from ring number 3 to 12 counted from the pith. Age-age correlations were calculated for cumulated density traits only. The wood density data were obtained with X-ray analysis of increment cores from 47 open-pollinated families of Norway spruce (Picea abies (L.) Karst.). The families had earlywood and latewood with significant differences in density for individual and cumulated rings and consequently for overall density. The latewood proportion had significant family variation for cumulated rings but not for all individual rings. Large fluctuations in environmental variance caused fluctuations in heritability estimates for successive rings. A strong decrease in environmental variance for all cumulated traits, especially from ring 3 to 5, resulted in a steady increase in heritability estimates. The latewood density had the highest heritability estimates and latewood proportion the lowest for both individual and cumulated rings. Overall density and the cumulated components at cambial age 12 showed strong genetic correlations with their respective traits at all younger ages.