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
Forfattere
Helmer BelboSammendrag
Det er ikke registrert sammendrag
Forfattere
Helmer BelboSammendrag
Gjennom prosjektet «Variabelt dekktrykk for tømmerbiler» er et system som gir tømmerbilføreren anledning til løpende regulering av dekktrykket etter hjulbelastning og kjøreforhold testet ut. Videre er det gjort analyser av vegslitasje og fremkommelighet, samt økonomiske effekter systemet kan få for både virkestransportør, skogsveg-eier og skogindustri. Denne fagrapporten summerer opp kunnskapsstatus for konseptet, presenterer resultatene fra prosjektet, og gir forslag til videre arbeid på tematikken. Bruk av dekktrykkregulering kan tillate større virkesbil-lass på offentlige veger med aksellastbegrensninger, gi jevnere virkestransport i våte perioder, og redusere vegvedlikeholdskostnadene på skogsveg. Bedre friksjon på vinterføre gir også bedre fremkommelighet, og kan muliggjøre virkestransport på en del av veiene som per i dag kun kan benyttes i barmarksesongen. Samlet kan aktiv bruk av dekktrykkregulering på tømmerbiler redusere kostnadene til transport og vegvedlikehold med anslagsvis 5 – 7 kr per m3. Virkestransportøren har likevel små økonomiske incentiver til investering i dekktrykkregulering. Derfor er det også lite sannsynlig at virkestransportørene vil investere i slike systemer om ikke en tilstrekkelig andel av de økonomiske fordelene ved systemet kanaliseres til virkestransportøren.
Forfattere
Helmer BelboSammendrag
Det er ikke registrert sammendrag
Sammendrag
The materials used in construction have a significant environmental impact and this is becoming more important as operational energy requirements continue to fall. It is therefore becoming increasingly important to take into account the environmental burdens associated with materials used in construction. Life cycle assessment (LCA) and Environmental Product Declarations (EPD) are useful tools for this purpose. When comparing the results of numerous LCA studies of different construction materials, the main question is often ‘Which material is better for the environment?’. The answer, however, is usually not as simple – but why is it so difficult to decide which material has the lowest environmental impact? To answer this question, we have to consider what life cycle assessment is and how an LCA is undertaken. The report covers the stages of an LCA, from defining the goal and scope of the respective study to the creation of the life cycle inventory (LCI), the life cycle impact assessment (LCIA) to the reporting and interpretation of the results. Additionally, the report goes in detail into how to approach published LCA studies, how to work with EPDs and the much-discussed issue of Carbon storage in buildings. In the final chapter, the report assesses the comparability of published studies evaluating the environmental impact of different building materials.
Sammendrag
Extractives from silver birch (Betula pendula) can play an important role in the future bioeconomy by delivering the feedstock, for instance, for antioxidative applications. It is, therefore, inevitable to gain knowledge of the distribution of extractive content and composition in the different tissues of the tree for estimating the potential volumes of valuable extractable compounds. This study examines the extractable compound distribution of different tree tissues such as outer and inner bark and wood, respectively, considering the original height of the stem and comparing the yields after Soxhlet and accelerated solvent extraction (ASE). Eleven parts of the model tree (seven stem discs and four branches) were separated into primary tissues and extracted with a ternary solvent system. The investigated extraction methods resulted in a comparable performance regarding yields and the composition of the extractives. The extractives were divided into single compounds such as betulin, lupeol, γ-sitosterol, and lupeone and substance groups such as carbohydrates, terpenes, aromatics, and other groups. The distribution of single substances and substance groups depends on the location and function of the examined tissues. Furthermore, the evidence for the correlation of a single substance’s location and original tree height is stronger for lupeol than for betulin. Primary betulin sources of the calculated betulin output are the outer bark of the stem and the branches. By using small branches, further potential for the extraction of betulin can be utilized. A model calculation of the betulin content in the current birch tree revealed a significant potential of 23 kg of betulin available as a valuable chemical resource after by-product utilization.
Sammendrag
Inthis study, we introduce Point2Tree, a modular and versatile framework that employs a three-tiered methodology, inclusive of semantic segmentation, instance segmentation, and hyperparameter optimization analysis, designed to process laser point clouds in forestry. The semantic segmentation stage is built upon the Pointnet++ architecture and is primarily tasked with categorizing each point in the point cloud into meaningful groups or ’segments’, specifically in this context, differentiating between diverse tree parts, i.e., vegetation, stems, and coarse woody debris. The category for the ground is also provided. Semantic segmentation achieved an F1-score of 0.92, showing a high level of accuracy in classifying forest elements. In the instance segmentation stage, we further refine this process by identifying each tree as a unique entity. This process, which uses a graph-based approach, yielded an F1-score of approximately 0.6, signifying reasonable performance in delineating individual trees. The third stage involves a hyperparameter optimization analysis, conducted through a Bayesian strategy, which led to performance improvement of the overall framework by around four percentage points. Point2Tree was tested on two datasets, one from a managed boreal coniferous forest in Våler, Norway, with 16 plots chosen to cover a range of forest conditions. The modular design of the framework allows it to handle diverse pointcloud densities and types of terrestrial laser scanning data.
Forfattere
Fride Høistad ScheiSammendrag
Det er ikke registrert sammendrag
Forfattere
Fride Høistad ScheiSammendrag
Det er ikke registrert sammendrag
Forfattere
Fride Høistad ScheiSammendrag
Det er ikke registrert sammendrag
Forfattere
Fride Høistad ScheiSammendrag
Det er ikke registrert sammendrag