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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.

2014

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Abstract

Woody biomass from the forest sector is an abundant resource for renewable energy generation. Conventional woody biomass materials such as timber and stem are normally high quality solid fuels for combustion applications in terms of ash related operational problems. Recently, new raw woody materials such as forest residue are gaining interests for energy production purpose. Forest residue is the remaining fraction after harvest and outtake of the wood timber, including tree tops, branches and barks. Compared to conventional woody biomass, the forest residue has a wide variation of ash content and concentration of ash forming matters. The aim of this work was to characterize and investigate different parts from Norway spruce trees regarding ash content, ash composition and ash melting and slagging behaviors. Different parts from spruce tree were studied in present work including stem wood, bark, branch and twigs. The ash content and ash melting temperature of the four fuel samples were measured through following standard procedures. Concentrations of main ash forming elements were analyzed by an inductively coupled plasma optical emission spectroscopy (ICP-OES). The ashes from stem wood, bark and twigs were further investigated by a scanning electron microscopy equipped with energy dispersive X-Ray analysis (SEMEDX) and X-Ray diffractometry (XRD). The results showed that the branches and twigs contain higher contents of ash forming matters than that of the stem wood. Chemical compositions of ashes from four parts of the spruce tree are dominated by Ca, K, and Si. The K and Na contents in the branches and twigs are significantly higher than that of stem wood and bark, indicating high tendency of ash melting and slagging. The melting points of ashes from branch and twigs were 100-200 °C lower than those of the ashes from stem wood and bark, respectively. SEM-EDX and XRD analysis, melting of ashes from branch and twigs are mainly attributed to formation and fusion of low temperature melting alkali silicates. Copyright © 2014,AIDIC Servizi S.r.l.

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Abstract

A survey to identify ophiostomatoid fungi that infect wounds on native Norwegian and Swedish broadleaved trees was undertaken during summer 2004. A fungus resembling a species of Sporendocladia was commonly isolated from the exposed cambium and inner bark of wounds. Morphological examination and comparisons of DNA sequence data for the ITS and 5.8S regions of the rRNA gene region led to its identification as Sporendocladia bactrospora. Pathogenicity trials on young Populus tremula and Betula pubescens trees showed that S. bactrospora is capable of causing lesions on these trees. There have been few previous reports of S. bactrospora, and in most cases, these have been as saprophytes on wood. In contrast, results of this study show that it is a common inhabitant of freshly made wounds on native broadleaved trees in Scandinavia, and it appears to contribute to staining of wood.