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.
2008
Abstract
In Norway, exterior wood structures have traditionally, nearly exclusively been made of untreated Norway spruce (Picea abies (L.) Karst) and pressure treated Scots pine (Pinus sylvestris L.). In recent years there has been a tendency that other wood species, like various Norwegian hardwoods or imported species, have been used in exterior above ground applications, often not surface treated. For several wood species, especially hardwoods, information regarding the durability in use class 3 is limited. Most information given in EN 350 part 2 is based on testing of the heartwood in ground contact. The test procedures for above ground test prescribed in European standards, both laboratory and field tests, have some weaknesses regarding natural durability testing. Hence, some new methods for accelerated above ground testing have been put forward. The main objectives of this project are to evaluate natural durability of Norwegian and some imported wood species for above ground applications, and to study various methods for assessing decay in wood. The project material and methods used in the project, and the results from double layer tests after one year of exposure has earlier been described, Flæte et al. (2006). This paper presents the results of the weight and MOE loss in small samples after about 3 years exposure above ground.
Abstract
Three unsprayed coffee farms (farm 1, 2 and 3) were studied for the natural occurrence of the insect pathogenic fungus Beauveria bassiana in Hypothenemus hampei populations throughout the rainy season of 2004 (July-November) and 2005 (July-December). B. bassiana infections were found during most sampling dates in both years, on all three farms. The B. bassiana infection levels were higher in 2005 than in 2004 with mean prevalence of 12.1 % and 2.7%, respectively. No consistent significant differences in infection level between farms were found in any of the years. B. bassiana infection levels fluctuated widely throughout the season, and peaked at 13.5% on farm 3 in 2004 and at 44.0% on farm 1 in 2005. The H. hampei population was significantly higher in 2004 than in 2005, with 6.9% of the berries infested in 2004 and only 0.7% in 2005. In both years, the H. hampei infestation level was significantly higher on farm 2. No consistent significant differences in H. hampei infestation levels were found between sampling dates on any of the farms. H. hampei infestation levels fluctuated throughout both seasons, and peaked at 15.3% on farm 2 in 2004 and 2.2% on farm 2 in 2005. No consistent density dependent correlation between H. hampei infestation level and B. bassiana infection level was found. Correlations between climatic conditions and R bassiana or H. hampei were not found. (C) 2007 Elsevier Inc. All rights reserved.
Authors
Erlend Ystrøm Haartveit Per Otto FlæteAbstract
Wood from different tree species is commonly similar in visual appearance but still have considerable differences in machining and wood properties. Even heartwood and sapwood from the same tree species may be difficult to separate visually, but the wood properties important for the quality of the final products may differ. Hence, within the forest products industry there is a great need to non-destructively evaluate wood quality prior to and during manufacturing in order to ensure effective allocation of raw material, and to obtain consistent and well defined quality of the end products. Near infrared spectroscopy is a promising technique because it requires minimal, if any, sample preparation and provides results rapidly, even when used on intact, opaque biological samples. In this paper we use near infrared spectroscopy combined with multivariate statistical analyses for classification of wood types. Case I considers heartwood and sapwood from Scots pine. On freshly cut wood heartwood and sapwood are visually similar, but the wood properties differ. Case II considers wood from tree different species of spruce, Norway spruce, Sitka spruce and Lutz spruce. The species have differences mechanical and machining properties. NIR spectra were recorded directly on solid wood surfaces. The multivariate statistical analyses were based on partial least squares methodology and resulted in successful classification of wood types in both cases. All models were validated using test set validation. In both cases the result showed that near infrared spectroscopy and multivariate statistics can be used to develop well-performing prediction models for classification of visually similar wood types.
Abstract
Rural communities in Norway have been under great economic stress in recent years. There has been an increasing debate about how to utilize the large potential in a growing tourism industry to promote rural employment and income. This study is based on the institutional view of innovation with a focus on institutions that are important for stimulating innovations. The objectives are: 1) to determine if networking is positively related to innovativeness and if innovativeness is positively related to performance in the nature-based tourism industry in Norway and 2) to develop an in-depth understanding of how different actors trigger a member of the industry to change, create, or otherwise innovate. An e-mail survey was conducted of companies across the country followed by a qualitative study in one Norwegian municipality. Results indicate that there is a positive connection between networking and innovativeness, and between innovativeness and performance. A qualitative case example illustrates the interaction among actors and the resulting impacts on the innovation process.
Abstract
Rural communities in Norway have been under great economic stress in recent years. There has been an increasing debate about how to utilize the large potential in a growing tourism industry to promote rural employment and income. This study is based on the institutional view of innovation with a focus on institutions that are important for stimulating innovations. The objectives are: 1) to determine if networking is positively related to innovativeness and if innovativeness is positively related to performance in the nature-based tourism industry in Norway and 2) to develop an in-depth understanding of how different actors trigger a member of the industry to change, create, or otherwise innovate. An email survey was conducted of companies across the country followed by a qualitative study in one Norwegian municipality. Results indicate that there is a positive connection between networking and innovativeness, and between innovativeness and performance. A qualitative case example illustrates the interaction among actors and the resulting impacts on the innovation process.
Abstract
Studies regarding the environmental impact of engineered nanoparticles (ENPs) are hampered by the lack of tools to localize and quantify ENPs in water, sediments, soils, and organisms. Neutron activation of mineral ENPs offers the possibility of labeling ENPs in a way that avoids surface modification and permits both localization and quantification within a matrix or an organism. Time-course experiments in vivo also may be conducted with small organisms to study metabolism and exposure, two aspects currently lacking in ecotoxicological knowledge about ENPs. The present report explains some of the prerequisites and advantages of neutron activation as a tool for studying ENPs in environmental samples and ecologically relevant organisms, and it demonstrates the suitability of neutron activation for Ag, Co/Co3O4, and CeO2 nanoparticles. In a preliminary experiment with the earthworm Eisenia fetida, the dietary uptake and excretion of a Co nanopowder (average particle size, 4 nm; surface area, 59 m(2)/g) were studied. Cobalt ENPs were taken up to a high extent during 7 d of exposure (concentration ratios of 0.16-0.20 relative to the ENP concentration in horse manure) and were largely retained within the worms for a period of eight weeks, with less than 20% of absorbed ENPs being excreted. Following dissection of the worms, Co-60 was detected in spermatogenic cells, cocoons, and blood using scintillation counting and autoradiography. The experimental opportunities that neutron activation of ENPs offer are discussed.
Abstract
The European pine sawfly Neodiprion sertifer is a widely distributed defoliator of pines that can cause substantial growth losses over extensive areas. It attacks most species of twoneedle pines in its distribution area, and have occasional short-lived outbreaks that may cover up to 200.000 ha. In Norway we have had outbreak populations in the eastern part of the country since 2004, and in an ongoing research project we are evaluating aerial application of the Neodiprion sertifer nuclear polyhedrosis virus (NsNPV) to control Neodiprion sertifer....
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Chemical methods to assess bioavailability in soil and sediment often use synthetic polymers that mimic uptake of organic compounds in organisms or microbial degradation. In this paper we have assessed a biomimetic extraction method using hydroxyl-beta-cyclodextrin (HP-beta-CD) to estimate uptake of the two insecticides alpha-cypermethrin (alpha-CYP) and chlorfen-vinphos (CFVP) in the earthworm Eisenia fetida. Additionally, a novel approach was developed to estimate the efficiency of biomimetic extractions. The study revealed that HP-beta-CD is a suitable surrogate for estimating the bioaccessibility of hydrophobic chemicals in soil. If one uses a 3.5 times higher amount of HP-beta-CD than soil, effective and reproducible extractions can be achieved within 48h. At these conditions, inclusion of dissolved chemicals by HP-beta-CD mimics uptake of a given compound into earthworms and takes into account sorption-related aspects that control biological uptake. The data indicate that, with increasing hydrophobicity, the affinity of organic chemicals to HP-beta-CD does not increase to the same degree as to soil organic matter. Therefore, a high surplus of HP-beta-CD is necessary to provide a sufficient extraction capacity in biomimetic extractions.