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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.

2017

Sammendrag

Askeskuddsjuke forårsakes av en liten sopp, Hymenoscyphus fraxineus, på norsk kalt askeskuddbeger. Sjukdommen har i løpet av kort tid spredd seg over store deler av Europas askeskoger. Soppen er en fremmed art som trolig stammer fra Asia hvor den er assosiert med asketrær som er nær beslektet med europeisk ask. Det er særlig unge trær som er utsatt, men også eldre trær kan drepes over tid. Mye er uklart angående hvordan soppen infiserer, men sporene spres med vind til bladene på asketrær. Dersom soppen klarer å vokse forbi bladfestet før bladfall vil den i løpet av vinteren angripe greinene. Typiske symptomer er sår i barken og døde skudd.

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Sammendrag

Many parties to the United Nation's Framework Convention on Climate Change (UNFCCC) base their reporting of change in Land Use, Land-Use Change and Forestry (LULUCF) sector carbon pools on national forest inventories. A strong feature of sample-based inventories is that very detailed measurements can be made at the level of plots. Uncertainty regarding the results stems primarily from the fact that only a sample, and not the entire population, is measured. However, tree biomass on sample plots is not directly measured but rather estimated using regression models based on allometric features such as tree diameter and height. Estimators of model parameters are random variables that exhibit different values depending on which sample is used for estimating model parameters. Although sampling error is strongly influenced by the sample size when the model is applied, modeling error is strongly influenced by the sample size when the model is under development. Thus, there is a trade-off between which sample sizes to use when applying and developing models. This trade-off has not been studied before and is of specific interest for countries developing new national forest inventories and biomass models in the REDD+ context. This study considers a specific sample design and population. This fact should be considered when extrapolating results to other locations and populations.

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Sammendrag

Bio-based building materials offer a wide range of outlooks, from traditional rustic to modern design products. Recent development in the science of materials significantly improves their functional performance. However, when considering the use of bio-materials in outdoor environments, materials will deteriorate due to processes like weathering, oxidation, biodegradation, wear, and decay. Consequentially, biomaterials may lose visual appeal, leading to a perceived need for replacement even if the material is far from reaching functional failure. Visual assessment is the most direct method for evaluation of the aesthetic appearance of materials. However, it possesses a high degree of subjectivity when performed by an untrained person. On the contrary, measurement of surface properties with dedicated sensors provides objective values that might be related to the current state of the material in use. Recent developments in field of optics and electronics opens a new possibility to perform measurements in-situ. Colour-, gloss-, or spectro-photo-meters allow non-destructive measurements without particular sample preparation. Since all of the above techniques provide complementary information, the multi-sensor approach is more frequently suggested for applied research. The material state can be assessed regularly during service life. In this case, such measurement turns into monitoring. The paper illustrates examples of assessment and monitoring of biomaterials’ degradation due to weathering. Direct implementation of various sensors is demonstrated. A proposal for the approach of combining data provided by various sensing techniques with data mining is also presented.

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Sammendrag

Green roofs are used increasingly to alleviate peaks of water discharge into the sewage systems in urban areas. Surface runoff from roofs contain pollutants from dry and wet deposition, and green roofs offer a possibility to reduce the amounts of pollutants in the water discharged from roofs by degradation and filtering. These pollutants would otherwise enter wastewater treatments plants and ultimately end up in sewage sludge that is spread on agricultural soils. The most common substrates used in green roofs have limited capacity for filtration and sorption. Also, more sustainable alternatives are sought, due to the high carbon footprint of these materials. Biochar is a carbon-rich material produced by pyrolysis of biomass, and several types of biochar have been described as good sorbents and filter materials. Biochar is also a light and carbon negative material, which may fulfill other desired criteria for new green roof substrates. We here report on an experiment where two types of biochar, produced from olive husks at 450 °C or from forest waste at 850 ° C were mixed with volcanic rock or peat, and tested for retention capacity of phenanthrene and six heavy metals in a column experiment with unsaturated gravimetric water flow lasting for 3 weeks. The results suggest that biochar as a component in green roof substrates perform better than traditional materials, concerning retention of the tested pollutants, and that different types of biochar have different properties in this respect.

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Sammendrag

This work presents the outcomes from two independent studies evaluating the chemical quality of groundwater in agricultural areas irrigated with wastewater from sugar and yeast industries. The evaluation was determined using chemical parameters representing typical contaminants of sugar industry wastewater (SIWW) and yeast industry wastewater (YIWW), and characterising the content of organic matter (BOD5), nutrients (NH4-N, NO3-N, TN and TP) and salts (Cl, SO4, Na and K). The studies reveal that food industry wastewater constitutes a valuable water-nutrient-rich medium that can be reused in agricultural applications as an alternative water resource for irrigation and nutrients for fertilisation. Furthermore, the reuse facilitates the sustainable discharge of wastewater through a soil-aquifer zone to the natural environment. This does not affect chemical quality of groundwater, which was comparable in areas irrigated and non-irrigated with SIWW and YIWW. Although some parameters (NO3-N, NH4-N, SO4, Cl and Na) displayed higher concentrations in groundwater from the fields irrigated with wastewater, these contents were within recommended healthbased guideline limits defined in either the groundwater quality standards or the drinking water quality norms. Only the contents of K revealed an exclusive groundwater impact from wastewater irrigation. This was confirmed in statistical tests employing theWard’s hierarchical clustering method, which exposed excessive amounts of K introduced into groundwater through irrigation with both SIWW and YIWW. However, this parameter is not considered to pose any health risk to humans or the environment, and its content is not restricted by quality guideline values for either groundwater or drinking water.

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Sammendrag

In this work, experimental and modelling investigations were conducted on biochars pyrolyzed at 350 °C and 600 °C, to determine the effect of pyrolysis temperature, hydrogen peroxide activation and pH on copper and zinc removal, in comparison with commercially available activated carbons. Characterization of biochars was performed by BET surface area, elemental analysis and FTIR spectroscopy. Experiments results demonstrated that biochar pyrolyzed at 600 °C adsorbed both copper and zinc more efficiently than biochar pyrolyzed at 350 °C. Chemical activation by H2O2 increased the removal capacity of biochar pyrolyzed at 350 °C. All investigated biochars showed a stronger affinity for copper retention, with a maximum adsorption capacity of 15.7 mg/g while zinc was 10.4 mg/g. The best adsorption performances were obtained at pH 5 and 6. Langmuir adsorption isotherm described copper adsorption process satisfactorily, while zinc adsorption was better described by Freundlich isotherm.