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.
2024
Forfattere
Martin Næsset HillestadSammendrag
Large volumes of Norway spruce (Picea abies (L.) Karst.) in Northern Norway are approaching maturity. Previous studies conducted on Norway spruce from Northern Norway, indicates lower density and mechanical properties than for Norway spruce grown in the rest of the country. This might be critical for use of Norway spruce from Northern Norway as structural timber. The purpose of this study was to assess lumber quality, density, modulus of elasticity and modulus of rupture on a sample of Norway spruce from Northern Norway, and to evaluate whether visual strength grading results in sufficient properties. Density and mechanical properties were compared to values from Southern Norway, and previous studies from Northern Norway. A sample consisting of 109 boards sawn from 12 trees of Norway spruce, collected from 4 trial stands in Northern Norway, was visually strength graded according to NS-INSTA 142, before density, modulus of elasticity and modulus of rupture was tested according to NS-EN 408. Characteristic values calculated according to NS-EN 384 and verified according to NS-EN 14358, were compared to the strength classes of NS-EN 338. Variation in density and mechanical properties were modelled with linear mixed models, where the random variance was separated into tree-variance and residual variance. Variables on board and log level were treated as fixed effects, and used as covariates in the models. Relative height, calculated as each log’s vertical position in relation to total tree height, was the most important variable for density. Density increased with increasing relative height. Density was important for modulus of elasticity and modulus of rupture, and both increased with increasing density. Variation in density between stands seems to be partly attributed to variation in latitude and altitude. Knots affected both modulus of elasticity and modulus of rupture, and differences in average knot diameter seems to coincide with differences in mechanical properties between stands. Differences in average knot diameter and mechanical properties between stands coincides with differences in silviculture. Mean values for density, modulus of elasticity and modulus of rupture were lower than what is observed in the Southern and middle parts of Norway, but higher than previous studies from Northern Norway. The visual grading resulted in most boards sorted as grade T2, followed by T1, T3 and T0. The characteristic values met requirements for all sorting grades apart from density in T3 for C30, and modulus of rupture in T1 for C18. Low numbers resulted in large uncertainties concerning characteristic values. Despite this, sorting grades T2 and T2+T3 met all requirements for C24. The results give positive indications for density, modulus of elasticity and modulus of rupture in Norway spruce from Northern Norway, and the properties as structural timber. The study is based on a limited sample of boards, collected from a limited number of trial stands, and this results in large uncertainties. Further studies are therefore needed, and should gain values more representative for the forest in Northern Norway.
Forfattere
Maurine Oluchukwu OkolieSammendrag
This study examines the potential of large-scale urine recycling as a sustainable solution to address sanitation challenges, enhance agricultural productivity, and improve food security in Bahir-Dar, Ethiopia. The approach involves establishing urine recycling systems (URS) that collect urine from onsite sanitation facilities and convert it to dry urine-based fertilizer (UBF) near collection sites for local farmers. Using a combination of primary and secondary data sources, this study performs a cost-benefit analysis (CBA) to evaluate the financial viability of implementing URS in Bahir Dar, focusing on direct monetary costs and benefits. The assessment includes metrics such as net present value (NPV), internal rate of return (IRR), benefit-cost ratio (BCR), and payback period (PBP) and is supplemented by sensitivity and scenario analyses to account for varying assumptions. The findings reveal that, under the set assumptions of this study, implementing urine recycling systems is not financially viable in Bahir Dar. The financial feasibility is highly dependent on the capacity of the urine recycling technology and the fees charged for using the toilet facilities. Higher dehydration capacity significantly improves financial outcomes, as does charging users for each use of the facilities. Charging higher fees per use enhances the economic viability of the system. Based on these findings, the study recommends further research on integrating indirect benefits, which include social and environmental benefits. This will provide a comprehensive understanding of the value of the urine recycling system.
Forfattere
Wiktoria Kaczmarek-DerdaSammendrag
Det er ikke registrert sammendrag
Forfattere
Pia Heltoft ThomsenSammendrag
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Forfattere
Wiktoria Kaczmarek-DerdaSammendrag
Det er ikke registrert sammendrag
Forfattere
Pia Heltoft ThomsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Wiktoria Kaczmarek-DerdaSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Håndtering av avfall med høyt innhold av plantevernmidler krever god oppfølging for å sikre en tilstrekkelig nedbrytning av plantevernmidler før bruk. Flere avfallshåndteringsanlegg tar imot planteavfall til kompostering, og produserer og selger kompostprodukter. Mange plantevernmidler og organiske miljøgifter brytes helt eller delvis ned under komposteringsprosessen. For de plantevernmidler som ikke brytes ned, er det behov for alternative løsninger. Landbruksdirektoratet har fokus på denne problemstillingen og finansierer prosjekter for å få mer kunnskap om bærekraftig håndteringa av materialer med høye konsentrasjoner av plantevernmidler.
Sammendrag
Det er ikke registrert sammendrag