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.
2023
Sammendrag
Sau, geit, rein, ku og gris. Hvem hører ikke hjemme her? Svaret er grisen. Den kan ikke leve av gras. Likevel er grisen gruppert sammen med grasetere og definert som rødt kjøtt. Dette blir det full forvirring av når både helse- og miljøråd skal gis.
Sammendrag
Det snakkes om overproduksjon av mat. Og det snakkes om at selvforsyningsgraden må økes. Likevel jobbes det målrettet med å redusere etterspørselen av kjøtt produsert på norsk gras.
Sammendrag
Field trials with Norway spruce seedlings from 84 full-sib families from a factorial cross in Opsahl Seed Orchard and 11 provenances were planted at eight sites between altitudes between 600 and 900 m in Oppland County in Norway. Measurements of tree heights and assessments of stem and branch defects were made at regular intervals until 34 years from seed. Data from measurements made in nursery trials and from artificial freezing trials were also available. The families from the seed orchard had on average 12 % better height growth than the provenances. For volume growth per hectare, measured in two of the trials 30 years after planting, the families had a superiority of more than 30 %. A large variation among families was present for height growth and additive genetic variation was the main genetic factor. For the maternal half-sib families, the ranking of families for height was stable after 15 years from seed, and the five best families selected for height at that age were at age 34 years 6 % taller and produced 13 % more volume per hectare compared with the mean of all families. Weak relationships were present between traits measured in the nursery trial, the freezing test and the field trials. Assessments were made of cone production at age 20 years after planting and showed variation among families for the frequency of trees with cones.
Sammendrag
Artificial freezing tests were performed on seedlings from Norway spruce families at the end of the first growing season. Similar tests were made on twigs collected from trees in a progeny test at the end of growing season nine. The 26 families in the early test were included in the short-term progeny test with 100 full-sib families from a 10 x 10 factorial cross. All families were also planted in seven field trials in Norway, Sweden and Finland, from which data on mortality, tree heights and stem damage at age 10 years are available. Significant difference was found among families for freezing test injuries on whole intact seedlings at the end of the first growing season and for lethal temperature of needles on detached twigs collected at the end of growing season nine. However, no relationships were found between the freezing test scores of families in the two types of tests or few between these scores and the traits measured in the short-term and field trials. The results show that frost hardiness testing of families at a young age, grown under artificial temperature and light conditions in nursery, is a weak predictor of their performance under natural conditions in field at older ages.
Sammendrag
The dimensional stabilisation of wood using thermosetting resins relies on the resin uptake into the cell walls. This study tested if a conditioning step after the impregnation and before the final heat-curing enhances the cell wall uptake to improve dimensional stabilisation without increasing the chemical consumption. Small blocks of Scots pine sapwood were vacuum-impregnated with an aqueous melamine formaldehyde solution and conditioned at 33, 70, or 95 % RH for up to 1 week before drying and curing the blocks at 103 °C. However, the conditioning step decreased the cell wall bulking and the moisture exclusion effect compared to the immediate heat curing of the impregnated samples. Analyses of the resin-treated samples by scanning electron microscopy, IR spectroscopy and confocal Raman microspectroscopy provided evidence of wood hydrolysis and polycondensation of the resin within the cell lumen during the conditioning step. Hydrolysis and removal of wood constituents may have counterbalanced the cell wall bulking of the resin. Polycondensation of the resin in the lumen increased its molecule size, which could have hindered the cell wall diffusion of the resin.
Forfattere
Michael Altgen Michael Fröba Julius Gurr Andreas Krause Martin Ohlmeyer Uta Sazama Wim Willems Martin NopensSammendrag
Water-sorption studies and certain organic chemistry reactions require water removal from cellulosic samples. This is hindered by the strong interaction of cellulosic materials with water, and it remains uncertain if a completely anhydrous state can be reached under common drying conditions. Here, different drying conditions were applied to wood and cellulose, and the residual moisture contents were quantified either gravimetrically or by coulometric Karl-Fischer titration. Vacuum-drying at 103 °C and ≤ 1 mbar for at least 360 min decreased the moisture content to ≤ 0.04%. However, in automated sorption balances, drying at atmospheric pressure under dry air or nitrogen flow left some samples with more than 1% moisture content. The residual moisture content obtained under dry gas flow was temperature dependent. Increasing the temperature up to 55 °C decreased the residual moisture content and cooling resulted in a moisture re-uptake, presumably due to small quantities of water vapor in the surrounding atmosphere. These effects must be considered in fundamental studies on water interactions of cellulosic materials.
Sammendrag
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