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1.	Skovsgaard, Jens Peter (författare) Bog om tarmvridrøn 2013 Ingår i: Skoven. - 0106-8539. ; 45, s. 551-551 Annan publikation (övrigt vetenskapligt/konstnärligt)abstract Book review N. Mayer & R.T. Klumpp (ed.) 2013: Elsbeere in Österreich – Monographie. Verein zur Erhaltung, Pflege und Vermarktung der Elsbeere - Genussregion Wiesenwienerwald Elsbeere, Michelbach.
2.	Edvardsson, Johannes, et al. (författare) Old wood in a new light : an online dendrochronological database 2023 Ingår i: International Journal of Wood Culture. - : Brill Academic Publishers. - 2772-3194 .- 2772-3186. ; 3:1-3, s. 442-463 Tidskriftsartikel (refereegranskat)abstract The Old Wood in a New Light database project focuses on the digitization and accessibility of the results of dendrochronological samples analyzed and archived at four Swedish university-based tree-ring laboratories at Lund University, Stockholm University, University of Gothenburg, and the Swedish University of Agricultural Sciences. Collaboration with the Environmental Archaeology Laboratory and Humlab at Umeå University enables long-term open access to data, raw data, and metadata. In this project, we (1) systematically undertake large-scale entry and open access publication of results from wood samples scientifically analyzed and archived by Swedish laboratories and the associated metadata, into the Strategic Environmental Archaeology Database (SEAD; www.sead.se) research data infrastructure, and (2) actively promote the database as a resource for new and ongoing interdisciplinary research initiatives. Including dendrochronological data in SEAD infrastructure allows interdisciplinary studies that combine major scientific and societal questions. Building on a pilot study of construction timber from southern Sweden and adaptation of SEAD digitization workflows, more than 70 000 samples archived at the four dendrochronological laboratories are now being handled in the project. The broad coverage of research networks, stakeholder interaction, and strategic support from the cultural heritage community is guaranteed owing to the ongoing collaboration between laboratories and an established international and multidisciplinary reference group.
3.	Hallingbäck, Henrik, et al. (författare) Association mapping in Salix viminalis L. (Salicaceae) - identification of candidate genes associated with growth and phenology 2016 Ingår i: Global Change Biology Bioenergy. - : Wiley. - 1757-1693 .- 1757-1707. ; 8:3, s. 670-685 Tidskriftsartikel (refereegranskat)abstract Willow species (Salix) are important as short-rotation biomass crops for bioenergy, which creates a demand for faster genetic improvement and breeding through deployment of molecular marker-assisted selection (MAS). To find markers associated with important adaptive traits, such as growth and phenology, for use in MAS, we genetically dissected the trait variation of a Salix viminalis (L.) population of 323 accessions. The accessions were sampled throughout northern Europe and were established at two field sites in Pustnas, Sweden, and at Woburn, UK, offering the opportunity to assess the impact of genotype-by-environment interactions (GxE) on trait-marker associations. Field measurements were recorded for growth and phenology traits. The accessions were genotyped using 1536 SNP markers developed from phenology candidate genes and from genes previously observed to be differentially expressed in contrasting environments. Association mapping between 1233 of these SNPs and the measured traits was performed taking into account population structure and threshold selection bias. At a false discovery rate (FDR) of 0.2, 29 SNPs were associated with bud burst, leaf senescence, number of shoots or shoot diameter. The percentage of accession variation explained by these associations ranged from 0.3% to 4.4%, suggesting that the studied traits are controlled by many loci of limited individual impact. Despite this, a SNP in the EARLY FLOWERING 3 gene was repeatedly associated (FDR<0.2) with bud burst. The rare homozygous genotype exhibited 0.4-1.0 lower bud burst scores than the other genotype classes on a five-grade scale. Consequently, this marker could be promising for use in MAS and the gene deserves further study. Otherwise, associations were less consistent across sites, likely due to their small estimates and to considerable GxE interactions indicated by multivariate association analyses and modest trait accession correlations across sites (0.32-0.61).
4.	Roos, Anders, et al. (författare) A product semantic study of the influence of vision on wood evaluation 2013 Ingår i: Wood and Fiber Science. - : Society of Wood Science and Technology. - 0735-6161. ; 45:4, s. 353-362 Tidskriftsartikel (refereegranskat)abstract Using product semantics, this study investigated how visual attributes of wood are perceived and interpreted semantically. The wood species alder, ash, aspen, beech, birch, elm, larch, lime, maple, oak, pine, and spruce were included. The subjects rated the samples based on the descriptive words natural, exclusive, ecofriendly, rough, inexpensive, modern, reliable, warm, cozy, solid, and light. The most significant differences in ratings were between softwoods and hardwoods. Principal component analysis yielded three dimensions based on visual perceptions: exclusive-modern, ecofriendly-natural, and light. Maple and ash and other hardwoods were seen as more exclusive and modern than spruce and pine. Pine, conversely, was perceived as the most ecofriendly-natural wood type. Beech and alder did not score high (or low) on any of the three dimensions, meaning that these gave a neutral impression. The potential use of these results in product design and interior design is discussed.
5.	Fernando, Dinesh, et al. (författare) Characterization and biological depectinization of hemp fibers originating from different stem sections 2015 Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 76, s. 880-891 Tidskriftsartikel (refereegranskat)abstract The wide variation of mechanical properties of natural fibers limits their applications in matrix compos-ites. The aim of this study is to evaluate the properties of hemp fibers from different stem sections (top,middle and bottom) and to assess fungal retting pretreatment of hemp from different stem sections withthe white rot fungi Phlebia radiata Cel 26 and Ceriporiopsis subvermispora. For the untreated hemp fibers,no apparent difference in tensile behavior for fiber bundles from different stem sections was observed,and more than 90% tested samples demonstrated plastic flow behavior. Fiber strength and stiffness werehighest for the fibers from the top and middle stem sections. These properties were related to the compositional make up and morphological properties of hemp fibers, notably the secondary fiber cell contents.In fungal retting, there was a strong dependence of depectinization selectivity on stem section, whichdecreased from bottom to top presumably due to the significantly higher lignin content in the bottomsection than in the top section (middle section was in between). Consequently, the fungal retting caused alower reduction in strength of fibers from the bottom section than in those from the top stem section, andessentially reversed the influence of stem section on fiber tensile strength through depectinization selec-tivity. At whole hemp stem level, the fungal retting with P. radiata Cel 26 exhibited better mechanicalproperties with an ultimate tensile strength, strain and stiffness of 736 MPa, 2.3% and 42 GPa, respec-tively, while fibers treated with C. subvermispora exhibited lower mechanical properties of 573 MPa, 1.9% and 40 GPa, respectively. The study thus also showed that less variable and high strength fibers may beproduced using the dependence of depectinization selectivity on stem section for composite application
6.	Fernando, Dinesh, et al. (författare) Effect of harvest time and field retting duration on the chemical composition, morphology and mechanical properties of hemp fibers 2015 Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 69, s. 29-39 Tidskriftsartikel (refereegranskat)abstract The large variability in the mechanical properties of hemp fibers creates difficulties for using them in high-grade composites. The objective of the present study was to determine the optimal growth stage for harvesting hemp fibers for use in composites and to evaluate the effect of field retting time on mechanical performance of the fibers. Reduction in bast content and thickness of the primary bast fiber layer in stems were found to be highly significant (P ˂ 0.01) with plant maturity. A significant increase in the secondary fiber fraction occurred with maturity, reaching a maximum value of 10% at seed maturity. A highly significant reduction in cellulose deposition in fiber cell walls was reflected by reduced fiber wall thickness with plant maturity and was related to the development and ripening of hemp seeds. A statistically significant increase in lignin deposition and slight decrease in pectins in hemp fiber cell walls was also noted with stem maturity. Microscopy observations and histochemical analyses corroborated results from chemical analyses and showed variations in morphological aspects and spatial micro-distributions of carbohydrates and lignin within the cell structure of the hemp stems between early- and late growth phases. Fibers harvested at the beginning of flowering exhibited high tensile strength and strain, which decreased with plant maturity. Reduction in strength was related to the increase in proportion of secondary fibers and decrease in cellulose deposition leading to inferior properties of the primary fibers. A negative effect of field retting occurred only after long term field retting (i.e. 70 days) which was presumably due to accelerated degradation of cellulose by the action of microorganisms.
7.	Sandberg, Dick, 1967-, et al. (författare) Wood Material Science, advanced PhD-course. 2007 Rapport (övrigt vetenskapligt/konstnärligt)
8.	Wernersson, Erik, 1984-, et al. (författare) Generating synthetic μCT images of wood fibre materials 2009 Ingår i: Proc. 6th International Symposium on Image and Signal Processing and Analysis. - Piscataway, NJ : IEEE. - 9789531841351 ; , s. 365-370 Konferensbidrag (refereegranskat)abstract X-ray Computerized Tomography at micrometer resolution (μCT) is an important tool for understanding the properties of wood fibre materials such as paper, carton and wood fibre composites. While many image analysis methods have been developed for μCT images in wood science, the evaluation of these methods if often not thorough enough because of the lack of a dataset with ground truth. This paper describes the generation of synthetic μCT volumes of wood fibre materials. Fibres with a high degree of morphological variations are modeled and densely packed into a volume of the material. Using a simulation of the μCT image acquisition process, realistic synthetic images are obtained. This simulation uses noise characterized from a set of μCT images. The synthetic images have a known ground truth, and can therefore be used when evaluating image analysis methods.
9.	Wernersson, Erik, 1984-, et al. (författare) Segmentation of Wood Fibres in 3D CT Images Using Graph Cuts 2009 Ingår i: Image Analysis and Processing – ICIAP 2009. - Berlin : Springer-Verlag. - 9783642041457 ; 5716, s. 92-102 Konferensbidrag (refereegranskat)abstract To completely segment all individual wood fibres in volume images of fibrous materials presents a challenging problem but is important in understanding the micro mechanical properties of composite materials. This paper presents a filter that identifies and closes pores in wood fibre walls, simplifying the shape of the fibres. After this filter, a novel segmentation method based on graph cuts identifies individual fibres. The methods are validated on a realistic synthetic fibre data set and then applied on μCT images of wood fibre composites.
10.	Sundblad, Eva-Lotta, 1956, et al. (författare) Social analys – en havsrelaterad samhällsanalys. Underlagsrapport för Sveriges inledande bedömning i havsmiljöförordningen 2012 Rapport (övrigt vetenskapligt/konstnärligt)abstract Havsmiljöförordningen, SFS 2010:1341, (HMF) ingår i en strategi för en ekosystembaserad förvaltning och ett hållbart nyttjande av havsmiljön som avses i Havsmiljödirektivet (2008/56/EG). Förordningen syftar till att upprätthålla eller nå en god miljöstatus i havsmiljön. Enligt HMF ska Havs- och vattenmyndigheten se till att det görs en inledande bedömningen av havsmiljön i de svenska delarna av de två förvaltningsområdena Nordsjön och Östersjön (13 § - 16 §). Den inledande bedömningen, som ska vara avslutad den 15 juli 2012 och rapporteras till Europeiska kommissionen senast den 15 oktober samma år, ska ligga till grund för fastställande av god miljöstatus, miljömål och miljöövervakningsprogram samt utarbetande av åtgärdsprogram för att nå uppsatta mål. I den inledande bedömningen ingår att utföra en ekonomisk och social analys, den förra kan delas in i två delar där den första syftar till att analysera nyttjandet av havsområdet och den andra delen att beskriva kostnaderna av att miljön i havsområdena försämras (HMF, 13 §, p.4 samt Havsmiljödirektivet, Artikel 8.1c). Det primära syftet med den sociala analysen i den inledande bedömningen är att skapa en bild av förutsättningarna för det kommande arbetet med att uppnå direktivets syften, dvs. god miljöstatus (GES, artikel 9). Analysen ska också tjäna som underlag vid utformningen av miljömål (artikel 10) som sedermera kommer att ligga till grund för åtgärdsprogram och styrmedel (artikel 13). Bedömningen inbegriper en analys av hur olika grupper i samhället kan beröras av havets nyttjande, havsrelaterade miljöproblem och deras åtgärdande. I denna studie lanseras en metod att genomföra en sådan analys. Metoden inbegriper en tankemodell som består av komponenterna Indirekta drivkrafter, Direkta drivkrafter, Påverkan/tillstånd/effekt i miljön, Effekt i samhället och Respons med. Modellen används tillsammans med en frågemall för att kartlägga aktörer och drivkrafter. Fallstudier avseende tre miljöproblem - selektivt överfiske av torsk samt oönskad spridning av kvicksilver och fosfor - visar att ett stort antal aktörer är inblandade såväl indirekt som direkt. Dessutom verkar aktörerna på olika nivåer: lokalt/regionalt, nationellt och internationellt. Varje miljöproblem behöver sin egen analys och har egna förutsättningar. Studien visar att den information som behövs för att besluta om åtgärder är relativt omfattande. Avvägningen av vilken mängd information som är tillräcklig och som bör övervakas i framtiden kan ha stor påverkan på utvecklingen i samhället och i miljön. Slutligen lämnas förslag på hur framtida havsmiljörelaterade samhällsanalyser kan genomföras.
11.	Bergkvist, Isabelle, et al. (författare) Skogen - en växande energikälla : sammanfattande rapport från Effektivare Skogsbränslesystem 2007-2010 2010 Rapport (övrigt vetenskapligt/konstnärligt)
12.	Scarfone, Antonio, et al. (författare) Storage dynamics and fuel quality of poplar chips 2014 Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 62, s. 17-25 Tidskriftsartikel (refereegranskat)abstract Poplar cultivation for wood/timber production has a growth production cycle of about 10-15 years. Usually the stem is separated from the crown and used to produce material of different kind such as veneer, pallets, panels, etc. For wood industries,. crowns generally represent waste material to be disposed of, causing economic and time losses. It is generally believed that the costs of managing crown biomass are higher than the potential incomes obtainable. Nonetheless, it is worthwhile investigating the possibility of using these byproducts as energy source and evaluating their value as a fuel. However, storing such residues presents several problems connected with spontaneous microbial degradation.The aim of this work was to evaluate the storage effects on chipped biomass deriving from the crown and stem wood of poplar and how they affect fuel quality and dry matter losses.A storage trial was carried out with three piles of stem wood chips and three of crown chips coming from a 15 year old poplar plantation. The piles were stored outdoors for six months under the same climatic conditions.The effect of storage on fuel quality was evaluated with respect to moisture content, gross and net calorific values, chemical composition, ash content, and bulk density.The variation of temperatures inside each pile due to heat development was continuously monitored and showed different trends between piles depending on source material. Results showed that chips from crown material had better storage properties and exhibited lower decay than chips from stem wood. (C) 2014 Elsevier Ltd. All rights reserved.
13.	Uetimane, Ernesto, Jr., et al. (författare) Application of non-symmetrical drying tests for assessment of drying behaviour of ntholo (Pseudolachnostylis maprounaefolia PAX) 2010 Ingår i: Holzforschung. - 0018-3830 .- 1437-434X. ; 64:3, s. 363-368 Tidskriftsartikel (refereegranskat)abstract Experiments concerning drying behaviour of ntholo (Pseudolachnostylis maprounaefolia PAX) were conducted to find a suitable drying schedule. Two non-symmetrical drying (NSD) tests were carried out to determine the drying behaviour of ntholo in terms of drying rate and stress behaviour. A tentative drying schedule was selected for comparison of the test results with those of similar tests with other known species. The schedule was tested in a laboratory kiln on 28-mm thick boards. According to both NSD tests and laboratory tests, ntholo dries easily but slowly. The laboratory drying lasted 266 h and achieved standard drying quality characterised by 8.9% moisture content, a moisture gradient of 1.2% and a case-hardening (gap) of 1.2 mm. Twist was the largest deformation with 3.4 mm per 1000 mm on average. The assigned schedule provided standard drying quality and it could be tested further in industrial kilns.
14.	Chen, Zhiqiang, et al. (författare) Method for accurate fiber length determination from increment cores for large-scale population analyses in Norway spruce 2016 Ingår i: Holzforschung. - : Walter de Gruyter GmbH. - 0018-3830 .- 1437-434X. ; 70:9, s. 829-838 Tidskriftsartikel (refereegranskat)abstract Fiber (tracheid) length is an important trait targeted for genetic and silvicultural improvement. Such studies require large-scale non-destructive sampling, and accurate length determination. The standard procedure for non-destructive sampling is to collect increment cores, singularize their cells by maceration, measure them with optical analyzer and apply various corrections to suppress influence of non-fiber particles and cut fibers, as fibers are cut by the corer. The recently developed expectation-maximization method (EM) not only addresses the problem of non-fibers and cut fibers, but also corrects for the sampling bias. Here, the performance of the EM method has been evaluated by comparing it with length-weighing and squared length-weighing, both implemented in fiber analyzers, and with microscopy data for intact fibers, corrected for sampling bias, as the reference. This was done for 12-mm increment cores from 16 Norway spruce (Picea abies (L.) Karst) trees on fibers from rings 8-11 (counted from pith), representing juvenile wood of interest in breeding programs. The EM-estimates provided mean-fiber-lengths with bias of only +2.7% and low scatter. Length-weighing and length2-weighing gave biases of-7.3% and +9.3%, respectively, and larger scatter. The suggested EM approach constitutes a more accurate non-destructive method for fiber length (FL) determination, expected to be applicable also to other conifers.
15.	Jay, Stephen, et al. (författare) International Progress in Marine Spatial Planning 2013 Ingår i: Ocean Yearbook. - : Brill. - 0191-8575 .- 2211-6001. ; 27:1, s. 171-212 Tidskriftsartikel (refereegranskat)abstract This article provides an overview of how MSP is being developed in a number of geographical and institutional contexts. This is not intended to be a thorough empirical analysis of the progress of MSP. Rather, the article aims to provide an indication of how MSP is developing in a number of leading maritime nations, the legislative and institutional arrangements these nations are adopting, the provisional outcomes of these processes and likely future challenges. The article begins by reviewing the origins of MSP and how it relates to other marine management processes. This is followed by a review of 13 national MSP initiatives, leading to conclu- sions about some of the factors currently at work in the uptake of MSP.
16.	Nilsson, Bengt, 1982-, et al. (författare) Hanteringens inverkan på skogsbränslets barrandel och fukthalt : – en jämförande studie mellan grönrisskotning och traditionell brunrisskotning av grot 2011 Rapport (övrigt vetenskapligt/konstnärligt)abstract I föreliggande studie har vi analyserat hur grotens barrandel påverkas av grönrisskotning jämfört med traditionell brunrisskotning. En hypotes har varit att den traditionella brunrisskotningen inte medför så stort barravfall som man tidigare trott. Om grönrisskotning skulle accepteras skulle det öppna möjligheter för nya tekniker, minskade kostnader, kortare ledtider samt ett större totalt uttag från den enskilda avverkningstrakten. Observera att även grönrisskotning ger ett torkat bränsle och inte skall förväxlas med färsk grot. Bestämning av fraktionsfördelning och fukthalt har genomförts i det material som levereras till den energiomvandlande industrin i anslutning till flisning av groten. Resultaten visar att grönrisskotning medför en kraftig avbarrning och innehåller betydligt mindre andel barr än färsk grot. Resultatet visar även att traditionellt brunrisskotad grot innehåller en hel del barr. I praktiken innebär det att grönrisskotad grot innehåller dubbelt så mycket barr (ca 8 % av grotens total torrmassa) som den traditionellt brunrisskotade (ca 4 % av grotens total torrmassa) vid leverans till den energiomvandlande industrin. Både grönrisskotning och brunrisskotning ger en tillfredsställande torkning och resultatet visar att det endast skiljer 5 procentenheter i medelfukthalt mellan grönrisskotad (36 %) för och brunrisskotad (31 %) grot. Det har även kunnat konstaterats att groten behöver ligga större delen av sommaren i små processorhögar för att uppnå den rekommenderade avbarrningen. All grot som skotas ihop tidigare än augusti månad är därmed att betrakta som mer eller mindre grönrisskotad. Slutsatsen blir att en stor del av den grot som idag levereras till den energiomvandlande industrin snarare är grönrisskotad än brunrisskotad och innehåller ca 5–10 % barr.
17.	Ximenes, Fabiano, et al. (författare) Improving understanding of carbon storage in wood in landfills: Evidence from reactor studies 2019 Ingår i: Waste Management. - : Elsevier BV. - 0956-053X. ; 85, s. 341-351 Tidskriftsartikel (refereegranskat)abstract Approximately 1.5 million tonnes (Mt) of wood waste are disposed of in Australian landfills annually. Recent studies have suggested that anaerobic decay levels of wood in landfills are low, although knowledge of the decay of individual wood species is limited. The objective of this study was to establish the extent of carbon loss for wood species of commercial importance in Australia including radiata pine, blackbutt, spotted gum and mountain ash. Experiments were conducted under laboratory conditions designed to simulate optimal anaerobic biodegradation in a landfill. Bacterial degradation, identified by both light microscopy and electron microscopy, occurred to a varying degree in mountain ash and spotted gum wood. Fungal decay was not observed in any wood samples. Mountain ash, the species with the highest methane yield (20.9mL CH4/g) also had the highest holocellulose content and the lowest acid-insoluble lignin and extractive content. As the decay levels for untreated radiata pine were very low, it was not possible to determine whether impregnation of radiata pine with chemical preservatives had any impact on decay. Carbon losses estimated from gas generation were below 5% for all species tested. Carbon losses as estimated by gas generation were lower than those derived by mass balance in most reactors, suggesting that mass loss does not necessarily equate to carbon emissions. There was no statistical difference between decay of blackbutt derived from plantation and older, natural forests. Addition of paper as an easily digestible feedstock did not increase carbon loss for the two wood species tested and the presence of radiata pine had an inhibitory effect on copy paper decay. Although differences between some of the wood types were found to be statistically significant, these differences were detected for wood with carbon losses that did not exceed 5%. The suggested factor for carbon loss for wood in landfills in Australia is 1.4%. This study confirms that disposal of wood in landfills in Australia results in long-term storage of carbon, with only minimal conversion of carbon to gaseous end products.
18.	Norbakhsh, Shahin, et al. (författare) Impact of iron(II) and oxygen on degradation of oak - modeling of the Vasa wood 2014 Ingår i: Holzforschung. - : Walter de Gruyter GmbH. - 0018-3830 .- 1437-434X. ; 68:6, s. 649-655 Tidskriftsartikel (refereegranskat)abstract In the wood of the Swedish 17th century warship Vasa, iron (Fe)-catalyzed chemical degradation has taken place after the salvation in 1961, which is manifested in increased acidity accompanied by cellulose degradation and reduced strength in the oak hull. Model studies on fresh oak impregnated with Fe(II) also led to tensile strength (TS) reduction in the same order of magnitude as observed in the wood of the Vasa. In the present study, further experiments have been performed concerning the Fe-catalyzed wood degradation. Namely, the degree of wood degradation was monitored quantitatively by measurement of the O-2 consumption of Fe(II)-impregnated oak, kept in closed vials with different relative humidities (RH), as a function of time. The initial O-2 consumption was high and declined with time. After 200 days, the accumulated O-2 consumption was 0.3-0.4 mmol g(-1) wood. Degradation products with low molecular weight were analyzed. The release of CO2 and oxalic acid (OA) was positively correlated with RH (0.235 and 0.044 mmol g(-1), respectively, at RH98% after 200 days). Samples kept for 1500 days at RH54% had accumulated 0.044 mmol OA g(-1) wood, which is equal to the average OA content in the interior of Vasa oak (corresponding to 4 mg g(-1)). Oak samples, from which extractives had been removed prior to Fe(II) impregnation, did not change their O-2 consumption or TS reduction compared to the nonextracted samples, indicating that extractives are not essential for cellulose degradation in this context.
19.	Miettinen, Arttu, et al. (författare) A non-destructive X-ray microtomography approach for measuring fibre length in short-fibre composites 2012 Ingår i: Composites Science And Technology. - : Elsevier BV. - 0266-3538 .- 1879-1050. ; 72:15, s. 1901-1908 Tidskriftsartikel (refereegranskat)abstract An improved method based on X-ray microtomography is developed for estimating fibre length distribution of short-fibre composite materials. In particular, a new method is proposed for correcting the biasing effects caused by the finite sample size as defined by the limited field of view of the tomographic devices. The method is first tested for computer generated fibre data and then applied in analyzing the fibre length distribution in three different types of wood fibre reinforced composite materials. The results were compared with those obtained by an independent method based on manual registration of fibres in images from a light microscope. The method can be applied in quality control and in verifying the effects of processing parameters on the fibre length and on the relevant mechanical properties of short fibre composite materials, e.g. stiffness, strength and fracture toughness.
20.	Jiang, Wen, et al. (författare) Particleboards with partially liquefied bark of different sizes 2019 Ingår i: 3rd International Scientific Conference “Wood-Science-Economy”, 21-22 October, Poznan, Poland. - Poznan : ACSmedia Pracownia Reklamy. ; , s. 30-30 Konferensbidrag (refereegranskat)abstract Utilizing biomass waste for wood-based composites has been driven by harsh competition for raw materials and environmental concerns for more sustainable products. Bark, as a by-product of the sawmilling and pulping industries, is a lignocellulosic material that is rich in lignin and extractives, and holds potential for producing chemicals and value-added materials. There are many possibilities of using bark in wood-based panel manufacturing such as making adhesives (e.g. bark tannin extractives, liquefied bark) or using it as a furnish in small amounts. Instead of using the completed liquefied bark products in the adhesive mixture, we have been working on a novel method of making particleboards by using partially liquefied bark as a furnish material with binding abilities. Thus, partially liquefied bark was mixed with wood chips with an aim to investigate the effect of different bark sizes on the properties of particleboards.Maritime pine (Pinus pinaster Ait.) bark was partially liquefied in the presence of ethylene glycol as solvent and sulphuric acid (H2SO4) as catalyst in 180˚C for 30 minutes. Four different sizes of bark were used: mix, coarse (> 2 mm), middle (1-2 mm), and fines (< 1 mm). One-layered 8-mm particleboards were prepared by mixing dry wood chips with the partially liquefied bark categories (9.1% or 20% w/w). Melamine-urea-formaldehyde (MUF) resin was 10% of the total weight of the furnish materials (dry wood chips and partially liquefied bark); while boards were also made without adding the resin. Mechanical and physical properties of the particleboards were tested according to the European standards, and ANOVA analysis of the results showed no statistically significant differences between varying bark sizes. Particleboards made with 9.1% of partially liquefied bark and with 10% of MUF resin met all the standard requirements for mechanical strength and thickness swelling. Particleboards made with 20% of partially liquefied bark and without adding MUF resin were inferior to those with MUF resin.From the current results we can conclude that it is possible to make particleboards from partially liquefied bark with competitive properties, and this supports our original idea of not completing the liquefaction process. In that respect, our work can contribute to energy and material savings when using liquefied products in wood panel manufacturing. More research is needed to optimize the process as well as to evaluate the formaldehyde emission level from this type of panels.
21.	Sandberg, Dick, 1967- (författare) Simuleringsverktyg för skiktlimning – nulägesanalys av processen och prioriterade arbetsområden. : Simulation Tools for laminated bending of veneer - state of the art for the process and priority work. 2007 Rapport (övrigt vetenskapligt/konstnärligt)abstract Denna rapport är en dokumentation av villkor och förutsättningar som gäller vid skiktlimning av faner för inredning och möbler inom delprojektet ”Skiktlimning av björk och bok” vid AB Åberg & Söner i Lönsboda.En analys av skiktlimningsprocessens status ger vid handen:Stora kunskapsluckor finns om de grundläggande fenomenen vid skiktlimning.Tydlig förändring av processerna sker mot:- mer avancerade produkter- korta serier- korta leveranstider- fokusering på pris och kvalitetSkiktlimning är ett av de få områden där svensk trämanufakturindustri har möjlighet att konkurrera mot låglöneländer.Ett framtidsscenario är att om 5 till 10 år kommer i stort sett alla beställningar via arkitekter och designers till företaget på elektronisk väg. Ritningarna är gjorda med hjälp av något CAD program. På grund av kravet på korta ledtider och utvecklingen mot allt mer avancerade produkter måste man kunna öppna och läsa olika CAD-program och utifrån dessa ritningar kunna avgöra om det är möjligt att i sin tillverkning tillverka den önskade produkten. Till sin hjälp i denna situation är företaget i behov av ett simuleringsverktyg i form av en matematisk modell som man har tillgång till. Med hjälp av detta verktyg skall risken kunna beräknas för att lokala brott i faneren inträffar, sprickor och limsläpp uppstår, samt att andra orsaker vid produktionen förorsakar kassaktioner av den färdiga eller nära färdiga produkten. Ytterligare ett önskemål är att det ritningsunderlag som man i digital form får från arkitekter i dess ursprungsform kan ligga till grund för tillverkningen. En analys av dagens tillverkning i relation till de framtida behoven som företaget kommer har genomförts och redovisas med förslag.
22.	Selig, Bettina, 1982-, et al. (författare) Segmentation of Highly Ligniﬁed Zones in Wood Fiber Cross-Sections 2009 Ingår i: Proceedings of the 16th Scandinavian Conference on Image Analysis (SCIA). - Heidelberg : Springer Berlin. - 9783642022296 ; 5575, s. 369-378 Konferensbidrag (refereegranskat)abstract Ligniﬁcation of wood ﬁbers has important consequences tothe paper production, but its exact eﬀects are not well understood. Tocorrelate exact levels of lignin in wood ﬁbers to their mechanical proper-ties, lignin autoﬂuorescence is imaged in wood ﬁber cross-sections. Highlyligniﬁed areas can be detected and related to the area of the whole cellwall. Presently these measurements are performed manually, which is te-dious and expensive. In this paper a method is proposed to estimate thedegree of ligniﬁcation automatically. A multi-stage snake-based segmen-tation is applied on each cell separately. To make a preliminary evaluationwe used an image which contained 17 complete cell cross-sections. Thisimage was segmented both automatically and manually by an expert.There was a highly signiﬁcant correlation between the two methods, al-though a systematic diﬀerence indicates a disagreement in the deﬁnitionof the edges between the expert and the algorithm.
23.	Van den Bulcke, Jan, et al. (författare) 3D tree-ring analysis using helical X-ray tomography 2014 Ingår i: Dendrochronologia. - : Elsevier BV. - 1125-7865 .- 1612-0051. ; 32:1, s. 39-46 Tidskriftsartikel (refereegranskat)abstract The current state-of-the-art of tree-ring analysis and densitometry is still mainly limited to two dimensions and mostly requires proper treatment of the surface of the samples. In this paper we elaborate on the potential of helical X-ray computed tomography for 3D tree-ring analysis. Microdensitometrical profiles are obtained by processing of the reconstructed volumes. Correction of the structure direction, taking into account the angle of growth rings and grain, results in very accurate microdensity and precise ring width measurements. Both a manual as well as an automated methodology is proposed here, of which the MATLAB (c) code is available. Examples are given for pine (Pinus sylvestris L), oak (Quercus robur L) and teak (Tectona grandis L.). In all, the methodologies applied here on the 3D volumes are useful for growth related studies, enabling a fast and non-destructive analysis.
24.	Osman, Syaiful, et al. (författare) Variation of chemical properties, crystalline structure and calorific values of native Malaysian bamboo species 2022 Ingår i: Wood and Fiber Science. - : Society of Wood Science and Technology. - 0735-6161. ; 54:3, s. 173-186 Tidskriftsartikel (refereegranskat)abstract The chemical properties of four common Malaysian bamboo species locally known as Beting (Gigantochloa levis), Semantan (Gigantochloa scortechinii), Lemang (Schizostachyum brachyladum) and Akar (Bambusa vulgaris) were studied. Chemical analysis shows that the alkaline extractive content for Malaysian bamboo species studied was within 24.4% to 25.6%, ethanol-toluene extractive content for Malaysian bamboo species was within 4.0% to 7.2% and water extractive content was within 10.4% to 12.8%. The average value of holocellulose content for Malaysian bamboo was between 64.5% to 70.67%, Klason lignin within 25.3% to 28.4%, cellulose content was between 28.5% to 33.8% and α-cellulose content for all bamboo species was within the range of 40.7% to 47.9%. The crystallinity of bamboo samples was between 42.0 to 44.4%, indicating their semi-crystalline structure. Heating value of bamboo ranged between 17.0 MJ/kg to 18.1 MJ/kg with G. scortechinii having the highest heating value.. The Inductive Couple Plasma Atomic Emission Spectroscopy (ICP-ES) analysis showed that Potassium (K) and Calcium (C) were the major elements in the ash of all bamboo samples. This study demonstrates the potential of native bamboo species as an alternative sustainable raw material to wood for a wide range of applications.
25.	Selig, Bettina (författare) Image segmentation using snakes and stochastic watershed : with applications to microscopy images of biological tissue 2015 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract The purpose of computerized image analysis is to extract meaningful information from digital images. To be able to find interesting regions or objects in the image, first, the image needs to be segmented. This thesis concentrates on two concepts that are used for image segmentation: the snake and the stochastic watershed. First, we focus on snakes, which are described by contours moving around on the image to find boundaries of objects. Snakes usually fail when concentric contours with similar appearance are supposed to be found successively, because it is impossible for the snake to push off one boundary and settle at the next. This thesis proposes the two-stage snake to overcome this problem. The two-stage snake introduces an intermediate snake that moves away from the influence region of the first boundary, to be able to be attracted by the second boundary. The two-stage snake approach is illustrated on fluorescence microscopy images of compression wood cross-sections for which previously no automated method existed. Further, we discuss and evolve the idea of stochastic watershed, originally a Monte Carlo approach to determine the most salient contours in the image. This approach has room for improvement concerning runtime and suppression of falsely enhanced boundaries. In this thesis, we propose the exact evaluation of the stochastic watershed (ESW) and the robust stochastic watershed (RSW), which address these two issues separately. With the ESW, we can determine the result without any Monte Carlo simulations, but instead using graph theory. Our algorithm is two orders of magnitude faster than the original approach. The RSW uses noise to disrupt weak boundaries that are consistently found in larger areas. It therefore improves the results for problems where objects differ in size. To benefit from the advantages of both new methods, we merged them in the fast robust stochastic watershed (FRSW). This FRSW uses a few realizations of the ESW, adding noise as in the RSW. Finally, we illustrate the RSW and the FRSW to segment in vivo confocal microscopy images of corneal endothelium. Our methods outperform the automatic segmentation algorithm in the commercial software NAVIS.
26.	Fundová, Irena (författare) Quantitative genetics of wood quality traits in Scots pine 2020 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Wood quality of commercial tree species is important for many wood processingindustries and thus should be considered for inclusion in forest tree improvementprograms. This thesis evaluated the suitability of various proxy methods for rapid andnon-destructive assessment of wood quality traits on standing trees of Scots pine and thepotential for genetic improvement of different wood quality traits through recurrentselective breeding.Penetrometer Pilodyn and micro-drill Resistograph were tested for non-destructiveassessment of wood density (DENPIL and DENRES, respectively), using SilviScan density(DENSILV) as a benchmark. A strong additive genetic correlation was observed betweenDENSILV and DENRES (rA = 0.96), whilst the correlation with DENPIL was substantiallylower (rA = 0.74). Furthermore, SilviScan stiffness (MOESILV) was used as a benchmarkfor evaluation of several approaches of calculating the dynamic modulus of elasticity(MOE) from standing-tree acoustic velocity (VELTREE). The combination of VELTREEand adjusted DENRES provided the most accurate estimate of MOETREE (rA = 0.91).Additionally, non-destructive acoustic sensing tools were tested at different stages ofwood processing (on standing trees, felled logs and sawn boards) using destructivelymeasured sawn-board stiffness (static modulus of elasticity, MOES) and strength(modulus of rupture, MOR) as benchmarks. They proved to be capable of accuratelypredicting MOES (rA ≈ 0.8) while VELTREE, adjusted DENRES and MOETREE wellreflected MOR (rA ≈ 0.9). Genetic variation of shape stability of sawn boards (bow, crookand twist) was also investigated. Under-bark grain angle (GRA) was found to be a goodpredictor of sawn-board twisting and crooking (rA = 0.84 and 0.62, respectively). Thechemical composition of juvenile wood (proportion of cellulose, hemicelluloses, ligninand extractives) was predicted from Fourier transform infrared (FTIR) spectra usingpartial least squares regression (PLSR) modeling. Individual-tree narrow-senseheritabilities (ℎi2) for all of the studied wood quality traits varied from low to moderate.Genetic improvement of sawn-board DEN, MOES and MOR as the target traits couldbe achieved through selective breeding for MOETREE, DENRES, stem straightness (STR)or GRA. Selection focusing on GRA would also result in lower bow, crook and twist.Despite the negative genetic correlations between growth and wood quality traits, apossibility of their simultaneous improvement was identified. An index combining stemdiameter (DBH) and MOETREE provided the best compromise.
27.	Amiandamhen, Stephen, 1983-, et al. (författare) Bioenergy production and utilization in different sectors in Sweden: A state of the art review 2020 Ingår i: BioResources. - : University of North Carolina Press. - 1930-2126. ; 15:4, s. 9834-9857 Forskningsöversikt (refereegranskat)abstract In the continual desire to reduce the environmental footprints of human activities, research efforts to provide cleaner energy is increasingly becoming vital. The effect of climate change on present and future existence, sustainable processes, and utilizations of renewable resources have been active topics within international discourse. In order to reduce the greenhouse gases emissions from traditional materials and processes, there has been a shift to more environmental friendly alternatives. The conversion of biomass to bioenergy, including biofuels has been considered to contribute to the future of climate change mitigation, although there are concerns about carbon balance from forest utilization. Bioenergy accounts for more than one-third of all energy used in Sweden and biomass has provided about 60% of the fuel for district heating. Apart from heat and electricity supply, the transport sector, with about 30% of global energy use, has a significant role in a sustainable bioenergy system. This review presents the state of the art in the Swedish bioenergy sector based on literature and Swedish Energy Agency’s current statistics. The review also discusses the overall bioenergy production and utilization in different sectors in Sweden. The current potential, challenges, and environmental considerations of bioenergy production are also discussed.
28.	Ander, Paul, et al. (författare) Sub-project 10: CRUW Mechanical Pulping Enzyme treatment of chips for energy reduction in TMP 2013 Rapport (övrigt vetenskapligt/konstnärligt)abstract In order to evaluate the possibilities of using enzymes for pre-treating softwood chips as a means of lowering the energy demand in mechanical pulping, impregnation and refining trials were performed using a set of different enzymes. The enzymes tested pectinase, xylanase and mannanase gave increased sugar release in the impregnation trials indicating that most of the sugar released occurred in the first 60 minutes and that activities thereafter seemed to level off. Refining trials using a small Wing refiner showed that for chips treated for 60 minutes with pectinase, xylanase and mannanase no energy savings to a given freeness level was observed. The property development was similar to that of reference pulps in the case of pectinase and xylanase while for chips treated with mannanase a less favourable development of the tensile index was noted. For chips treated for two hours, using xylanase or pectinase, energy savings could be observed for pectinase treated chips down to a freeness level of 200 CSF. However when refined further, the properties approached those of the reference pulp. Considering the much higher enzymatic activity reached when the initial fibre material was further disintegrated it is assumed that the possibilities for enzymes to attack desired structures of the intact fibre wall may have been too few even in the case of Impressafiner treated material.
29.	Andersson, Johanna, et al. (författare) Comparison of steaming and boiling of root vegetables for enhancing carbohydrate content and sensory profile 2022 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 312 Tidskriftsartikel (refereegranskat)abstract Root vegetables have unique techno-functional and nutritional properties however, their use in processed foods is limited to a few species, partially due to a lack of knowledge related to the impact of thermal treatments on the sensory properties. This study investigated the effect of steaming and boiling on the microstructure, mechanical properties, and sensory profile of three model root vegetables with distinct carbohydrate composition: Jerusalem artichoke (Helianthus tuberosus L.), parsnip (Pastinaca sativa), and beetroot (Beta vulgaris). Thermally treated Jerusalem artichoke and parsnip showed higher content of cell wall polysaccharides, particularly β-glucans (e.g. cellulose) and pectic components, compared to raw. Steaming produced more cell shrinkage and loss of cell-cell adhesion than boiling, leading to softer vegetables. Processed beetroot showed loss of cell turgor and drastic softening but not clear changes in overall carbohydrate content. The scores for several flavour and in-mouth attributes were higher for steamed vegetables compared to boiled. Our results give insights on the processability of root vegetables towards products with enhanced sensory and nutritional properties.
30.	Samuelsson, Robert, et al. (författare) Inblandning av stärkelse och lignosulfonat i pellets vid Bioenergi i Luleå AB : rapport från Pelletplattformen II 2014 Rapport (övrigt vetenskapligt/konstnärligt)abstract Ett fabriksförsök genomfördes vid Bioenergi i Luleå där två katjonbaserade stärkelsematerial (Solbind 35 och Solbind 790), ett kalciumbaserat lignosulfonat (Lignobond) samt ett kalcium/magnesiumbaserat lignosulfonat (Pelltech) blandades in i tallspån. En experimentell design för respektive additiv med två kvantitativa variabler på tre nivåer användes. Designerna omfattade följande parametrar: spån av tre olika fukthalter mellan 10-12 % baserad på rå vikt; inblandning av additiv på tre nivåer mellan 0-1 %. Den statistiska analysen baserad på MLR visade att fukthalten var den viktigaste parametern för bulkdensitet och presström medan inblandningsgrad av additiv var viktigast för hållfasthet och finfraktion. För Lignobond och Solbind 790 gav inblandning av additiv en minskad strömförbrukning vid pressningen, medan Solbind 35 gav en oförändrad strömförbrukning och Pelltech en ökad strömförbrukning. Samtliga additiv gav en förbättrad pelletskvalitet, främst genom ökad hållfasthet och minskad finfraktion.
31.	Seisenbaeva, Gulaim (författare) Comparative Assessment of Wet Torrefaction 2013 Ingår i: Energy and Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 27, s. 6743-6753 Tidskriftsartikel (refereegranskat)abstract Wet torrefaction of typical Norwegian biomass fuels was studied within the temperature window of 175-225 degrees C, using a benchtop autoclave reactor of 250 mL in volume from Parr Instrument. Two types of local biomass fuels were employed as feedstock, Norway spruce (softwood) and birch (hardwood). Effects of process parameters including pressure, reaction temperature, holding time, and feedstock particle size on the yield and properties of the solid products were investigated. It appears that birch wood is more reactive and produces less solid products than spruce wood in the same wet torrefaction conditions. Increasing pressure above the saturated vapor pressure of water enhances the torrefaction rate. Both reaction temperature and holding time have significant effects on solid product yield and fuel properties of wet torrefied biomass. The yield of solid products is slightly reduced with decreasing feedstock particle size. The ash content of biomass fuel is significantly reduced by wet torrefaction. In addition, a comparison between wet and dry torrefaction supported by regression analyses and numerical predictions shows that wet torrefaction can produce solid fuels with greater heating values at much lower temperatures and shorter holding times.
32.	Stading, Mats, 1962 (författare) Physical properties of a model set of solid, texture-modified foods 2021 Ingår i: Journal of Texture Studies. - : Wiley. - 1745-4603 .- 0022-4901. ; 52:5-6, s. 578-586 Tidskriftsartikel (refereegranskat)abstract Those suffering from swallowing disorders, or dysphagia, require texture-modified foods for safe swallowing. The texture is modified according to the severity of the disorder, as maintained by the guidelines outlining classes of texture-modified foods, ranging from viscous soups to soft, solid foods. As a basis for studies of bolus rheology and oral response of solid texture-modified foods, a set of well-defined, solid foods has been identified and characterized regarding texture and physical properties. Gelled food is compared to both the firmer timbale class and to the corresponding regular food. Foods eaten at room temperature were chosen to avoid temperature effects: bread, cheese, tomato, and the combination into a sandwich. All foods were tested as gel, timbale, and regular food. The texture was determined by compression and penetration tests, thereby showing a decrease in strength (compression stress), stiffness (modulus), and penetration force for increased degree of modification. The moisture content increased with increased degree of modification. The structural change from room to oral temperature was monitored by the complex shear modulus that showed a decrease with increasing temperature. Cheese and the gelatine-based tomato gel showed a distinct melting when the temperature was increased to 37 degrees C. The texture-modified foods were softer and moister in all aspects as compared to the regular foods, which follows the intended modification. The classes for the texture-modified foods were qualitatively comparable to other national classification systems with regard to solid foods, but there is a lack of objective, physics-based classification of texture, especially for solid, texture-modified foods.
33.	Taghiyari, Hamid Reza, et al. (författare) Correlation between gas and liquid permeability with noise reduction coefficient in insulation boards made from sugar cane bagasse 2017 Ingår i: Bulgarian Journal of Agricultural Science. - : Agricultural Academy in Bulgaria. - 1310-0351. ; 23:3, s. 674-681 Tidskriftsartikel (refereegranskat)abstract Specific gas and liquid permeability, as well as noise reduction coefficients, in insulating boards made of sugar-cane bagasse were studied here. Urea-formaldehyde (UF) and melamine-urea-formaldehyde (MUF) were used to produce homogeneous as well as three-layered insulating boards with three densities of 0.3, 0.4, and 0.5 g/cm3. The obtained results indicated that MUF slightly decreased gas and liquid permeability, but it did not significantly affect the noise reduction coefficients. Gas and liquid permeability were considerably affected by the density of the boards, due to the compression between the bagasse particles and less spaces and voids to let the fluids to pass through. However, noise reduction coefficients were significantly affected both by the density, as well as the board-type. More compression between the particles and the consequent less space between the bagasse particles entangled the waves; further more, the sudden change between the layers in the three-layered boards formed a barrier towards transmission of waves.
34.	Wessels, C. B., et al. (författare) Variation in physical and mechanical properties from three drought tolerant Eucalyptus species grown on the dry west coast of Southern Africa 2016 Ingår i: European Journal of Wood and Wood Products. - : Springer Science and Business Media LLC. - 0018-3768 .- 1436-736X. ; 74:4, s. 563-575 Tidskriftsartikel (refereegranskat)abstract Southern Africa, and specifically its western parts is dominated by low rainfall areas, and it is expected that the rainfall in most of these parts will in future decrease further due to climate change. Woodlots of fast-growing, non-invasive tree species can provide the opportunity to produce wood and release the pressure on natural woodlands, while creating much needed income to inhabitants. Over the last two decades several trials of Eucalyptus species that could potentially withstand arid conditions were established on the South African west coast. The three most promising genotypes according to their volume growth were selected among 46 pure and hybrid species from two 20-year-old trials for further evaluation. These included 10 Eucalyptus grandis Ã— Eucalyptus camaldulensis hybrid trees, 9 Eucalyptus gomphocephala trees, and 9 Eucalyptus cladocalyx trees for a total of 28 trees. The objective of the study reported here was to investigate the within-tree and between species variability of selected physical and processing properties determining the suitability of these three species for lumber production. The density, microfibril angle, spiral grain angle, MOE, MOR, radial and tangential shrinkage, twist, bow, splitting, and collapse were measured in a radial and longitudinal gradient. Valuable insights were gained which could provide decision support for planting, processing and further research on these species when grown in arid conditions. The E. grandis Ã— camaldulensis hybrid was inferior in terms of most relevant properties to the other two species evaluated. The main shortcoming of both E. gomphocephala and E. cladocalyx was the high levels of twist in lumber.
35.	Nilsson, Börje, et al. (författare) A method for under bark detection of the wood grain angle radial dependence 2007 Ingår i: Wood Material Science and Engineering. - : Taylor & Francis. - 1748-0272. ; 2:3,4, s. 118-129 Tidskriftsartikel (refereegranskat)abstract Twist in wood, being closely related to spiral grain, may cause serious problems in building structures, furniture, and joinery. It is therefore of great interest to sort out, at an early stage in the manufacturing process, trees, logs and boards that have an access of spiral grain. The spiral grain pattern is described by a helical deviation of the fibre direction in relation to the longitudinal direction of a living tree or a log and seems to be an indicator for other defects such as compression wood. Remote microwave sensing of spiral grain has received a large interest during the latest two decades. Its development has been impeded by the large variation with moisture content of the microwave properties of wood and by the complexity in modelling the electromagnetic field in a log with spiral grain. A review is presented of a direct method with no requirement of information on moisture content for boards. This procedure has recently been generalized to cylindrical logs and trees having a constant slope of the grain. A further generalization is presented here to allow for the normal spiral grain pattern with radially changing slope of grain in wood under bark. Based on this theory, a measurement procedure is proposed for the detection of wood grain angle with radial dependence, requiring no information on moisture content in the sapwood, also applicable for completely or partially frozen wood. A suitable application would be an instrument to use in the forest for measurements on living trees or logs.
36.	Ahmed, Sheikh Ali, Senior Lecturer, 1977-, et al. (författare) Anatomical, Physical, Chemical, and Biological Durability Properties of Two Rattan Species of Different Diameter Classes 2022 Ingår i: Forests. - Switzerland : MDPI. - 1999-4907. ; 13:1 Tidskriftsartikel (refereegranskat)abstract Rattan cane is an important forest product with economic value. Its anatomical, physical, and biological properties vary with the cane height. This makes it difficult to select the appropriate cane diameter for harvesting. Understanding the material properties of rattan cane with different diameter sizes is important to enhance its utilization and performance for different end uses. Thus, the present study was performed on two rattan species, Calamus zollingeri and Calamus ornatus, at two different cane heights (bottom/mature and top/juvenile). Calamus zollingeri was studied at diameter classes of 20 mm and 30 mm, while Calamus ornatus was analyzed at a diameter class of 15 mm. The anatomical properties, basic density, volumetric swelling, dynamic moisture sorption, and biological durability of rattan samples were studied. The results showed that C. zollingeri with a 20 mm diameter exhibited the highest basic density, hydrophobicity, dimensional stability, and durability against mold and white-rot (Trametes versicolor) fungi. As confirmed by anatomical studies, this could be due to the higher vascular bundle frequency and longer thick-walled fibers that led to a denser structure than in the other categories. In addition, the lignin content might have a positive effect on the mass loss of different rattan canes caused by white-rot decay.
37.	Bonarski, Jan T., et al. (författare) Effects of cell wall ultrastructure on the transverseshrinkage anisotropy of Scots pine wood 2015 Ingår i: Holzforschung. - : Walter de Gruyter. - 0018-3830 .- 1437-434X. ; 69:4, s. 501-507 Tidskriftsartikel (refereegranskat)abstract A hypothesis for explaining the differential anisotropicshrinkage behavior of wood has been proposed,and it was based on the differences in the cell wall ultrastructure.The starting point of the consideration is thatwood shrinkage is governed by its chemical composition,ultrastructure, and gross anatomy. It is also well knownthat the transverse shrinkage anisotropy of earlywood(EW) is more pronounced than that of the latewood (LW).In the paper, the cell wall ultrastructure and shrinkageanisotropy has been related to each other, and to thispurpose, a set of crystallographic texture descriptorswas applied. The descriptors are based on X-ray diffraction(XRD) experiments conducted on matched EW samplesfrom different growth rings of Scots pine. The rangeof the microfibril angle (MFA) was identified. The ratio ofthe maxima of inverse pole figures (IPFs) of both the tangential(T) and radial (R) directions was determined. Theratios quantify the inhomogeneity of the spatial arrangementof the ordered areas. The results of the study clearlyindicate that the transverse shrinkage of wood is governedmostly by a specific ultrastructural organization of moderatelyorganized cell wall compounds.
38.	Emanuelsson, Urban, et al. (författare) Landsomfattande slytäkt – potential, hinder och möjligheter 2014 Rapport (övrigt vetenskapligt/konstnärligt)
39.	Erlandsson, Martin, et al. (författare) Underlagsdata för hållbarhetsbedömning i BioMapp 2024 Rapport (övrigt vetenskapligt/konstnärligt)abstract Denna rapport utgör en samlad dokumentation av underlags data, med avseende på de olika industriprocesser som ingår i visualiseringsverktyget BioMapp. De skogsindustriella processerna som beskrivs i rapportens bilagor baseras på en allmänt accepterad inventeringsmetodik för att beskriva skogsbaserade produkters miljöpåverkan och andra hållbarhetsindikatorer i ett livscykelperspektiv. Det systemanalytiska verktyg som används i projektet är livscykelanalys (LCA) på så sätt som det tillämpas i miljövarudeklarationer för produkter (EPD).De inventeringsdata som redovisas har en ambition att vara representativa för den typ av processer och miljöbelastning som är relevanta för svenska förhållande. Det har dock inte varit möjligt inom ramen för projektet att göra kompletta branschsammanställningar.
40.	Hallingbäck, Henrik, et al. (författare) Optimal timing of early genetic selection for sawn timber traits in Picea abies 2018 Ingår i: European Journal of Forest Research. - : Springer. - 1612-4669 .- 1612-4677. ; 137:4, s. 553-564 Tidskriftsartikel (refereegranskat)abstract In breeding Norway spruce, selection for improved growth and survival is performed at age 10-15 years in order to optimize genetic gain per year. We investigated whether a selection based on wood traits such as density and grain angle, measured under bark in the field at the same age would be informative enough with respect to structural quality traits of sawn boards. To achieve this objective, a sawing study was conducted on the butt logs of 401 trees from a 34-year-old Norway spruce progeny trial situated in southern Sweden. Stem discs were excised from the top of the logs and radial profile data of grain angle, and wood density was recorded for specific annual rings. The sawn and dried boards were assessed for structural traits such as twist, board density, bending stiffness (static modulus of elasticity, sMoE) and bending strength (modulus of rupture, MoR). Additive genetic correlations (r (a)) between single annual ring density measurements and board density, sMoE and MoR were consistently strong (r (a)> 0.7) for annual rings 5-13. Genetic correlations of similar magnitude between grain angle and board twist were estimated for all investigated annual rings (from 2 to around 26 under bark). Consequently, it was found that indirect selection for wood density and grain angle at the tree age 10-16 years would result in more genetic gain per year than selection at later ages. This makes it feasible to perform simultaneous selection of progeny in the field for both growth and wood traits at similar ages.
41.	Jones, Grace (författare) Birch Stem and Wood Traits in Genetic and Silviculture Trials in Southern Sweden 2022 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Swedish tree species of birch (silver: Betula pendula and downy: B. pubescens) are often neglected during forest management activities, resulting in low value logs. This thesis investigated birch stem characteristics and wood properties important for solid wood products, in genetics and management trials in southern Sweden. As well as visual stem size and form measurements, non-destructive testing and evaluation (NDT) tools were used to indirectly estimate wood density (hardness), wood stiffness, and grain angle.The results of this work suggest that for the 19-year-old silver birch and 15-year-old downy birch sites, important solid wood traits were under a reasonable degree of genetic control. It seems possible to breed birch to improve grain angle since heritability and genetic variation was high for this trait. Silver birch genotypes are expected to perform similarly across sites. At a site with both birch species, silver birch was larger with denser wood than downy birch. Few genetic correlations between measurements means selection for one trait will not inadvertently affect another trait. The radial density profiles showed density was continuing to increase. Acoustic velocity (AV) and fibre length were highly correlated, hardness and density were related, and ring width was related to ring density. In a 35-year-old planted Norway spruce stand, naturally regenerated birch AV was not different between treatments (20% or 50% of plot trees were birch by number). However, a correlation was observed between DBH and AV. This older site may reflect common Swedish conditions since planting birch is rare, and likely had more mature birch wood than the genetics trials. Although meeting an immediate need for studies of birch wood properties from managed stands, this work covered few sites. To meet this limitation the tools and techniques applied in this thesis could be used in further studies. The results of this thesis work will be of interest to forest managers who want to breed birch, or select birch stands, for solid wood products.
42.	Jones, Grace, et al. (författare) Genetic Parameters of Stem and Wood Traits in Full-Sib Silver Birch Families 2021 Ingår i: Forests. - : MDPI. - 1999-4907. ; 12:2, s. 1-17 Tidskriftsartikel (refereegranskat)abstract This study investigated heritability of stem and wood traits to improve Swedish silver birch (Betula pendula Roth.) through breeding. Birch is 12% of Sweden’s forest area but mainly used for low value pulp or firewood. This paper applied non-destructive test (NDT) methods, and estimated traits’ heritability (h2), to help breed birch for high value solid wood products. Two trials of 22 families were assessed at age 19 for stem diameter (DBH), stem straightness, rough brown bark height (BH), grain angle (GA), Pilodyn penetration depth (Pilo) and acoustic velocity (AV). X-ray densitometry was performed on a subsample of radial cores taken at 1.3 m from the ground to get an average benchmark density. The h2 values were moderate for GA (0.20 and 0.21) and Pilo (0.53 and 0.48) at the two sites, but the h2 values for AV were low (0.05 and 0.30). There were moderate genotypic correlations between BH and DBH (0.51–0.54). There were low genotypic and phenotypic correlations between NDT measurements and other traits so including NDT in birch breeding efforts should not inadvertently reduce size, stem or wood quality. The high genetic correlations between sites suggest that GA, Pilo and AV values were determined more by genotype than by environment.
43.	Jones, Grace, et al. (författare) Non-Destructive Evaluation of Downy and Silver Birch Wood Quality and Stem Features from a Progeny Trial in Southern Sweden 2023 Ingår i: Forests. - : MDPI. - 1999-4907. ; 14:10 Tidskriftsartikel (refereegranskat)abstract This study investigated whether improved downy birch could perform as well as improved silver birch, and whether there was sufficient genetic variation and control for non-destructive testing (NDT) values to include them as selection traits in breeding programs. NDT tools were applied to a 15-year-old downy birch family trial intermixed with improved silver birch. Average diameters, fissured bark height, and grain angle were higher for silver than downy birch. The genetic analysis for downy birch provided estimates of narrow-sense heritability (h2) for acoustic velocity and Pilodyn penetration depth that were above 0.3 but had low genetic variation. Grain angle had relatively high genetic variability (18%) and an h2 of 0.20. A subsample of 49 trees had 4 mm cores x-rayed for wood density estimates, and 34 stems had 12 mm cores macerated for cell measurements. t-tests revealed that average wood density and cell measurements were not significantly different between species. For silver and downy birch, fiber length and vessel length increased between inner and outer measurement positions, and fiber length was reasonably correlated with acoustic velocity. Silver birch tended to have denser and stiffer wood, while downy birch had less rough bark and straighter grain, and these results are in agreement with existing knowledge. The h2 values were similar to those observed in other birch species and indicate there is potential to breed for improved wood density and grain angle in downy birch.
44.	Jones, Grace, et al. (författare) Relating estimates of wood properties of birch to stem form, age and species 2024 Ingår i: Journal of Forestry Research. - : Springer. - 1007-662X .- 1993-0607. ; 35:1 Tidskriftsartikel (refereegranskat)abstract Birch has long suffered from a lack of active forest management, leading many researchers to use material without a detailed management history. Data collected from three birch (Betula pendula Roth, B. pubescens Ehrh.) sites in southern Sweden were analyzed using regression analysis to detect any trends or differences in wood properties that could be explained by stand history, tree age and stem form. All sites were genetics trials established in the same way. Estimates of acoustic velocity (AV) from non-destructive testing (NDT) and predicted AV had a higher correlation if data was pooled across sites and other stem form factors were considered. A subsample of stems had radial profiles of X-ray wood density and ring width by year created, and wood density was related to ring number from the pith and ring width. It seemed likely that wood density was negatively related to ring width for both birch species. Linear models had slight improvements if site and species were included, but only the youngest site with trees at age 15 had both birch species. This paper indicated that NDT values need to be considered separately, and any predictive models will likely be improved if they are specific to the site and birch species measured.
45.	Nilsson, Bengt, 1982- (författare) Extraction of logging residues for bioenergy : effects of operational methods on fuel quality and biomass losses in the forest 2016 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Wood products play a key role in the transformation to a more sustainable society based on renewable bio-based resources, together with the positive effects on climate mitigation by replacing fossil fuels. However, to increase the use of forest fuel in practice it is important to understand the effects of handling and storage on its quality and removal of nutrients from the forest. This thesis addresses these effects with special focus on a comparative evaluation of the traditional dried-stacked with “new” and to some extent more controversial fresh-stacked methods for extraction of logging residues from Norway spruce (Picea abies (L.) Karst).The results indicate that a normal extraction of logging residues will leave at least 20% of logging residues at the clear-felled area, in accordance with Swedish Forest Agency recommendations. However, the results also indicate that the ambition of the dried-stacked method to leave the majority of the needles well spread over the clear-felled area does not meet these recommendations. In fact, the harvesting operation is more important than the extraction method, with respect to how much logging residues (nutrients) being left in the forest. The results also show that the quality of fuel yielded by the two handling methods differs only to minor extent, indicating that other factors have stronger effects, where “dried-stacked” and “fresh-stacked” logging residues from different clear-felling areas is often similar. Generally, logging residues stored over summer (regardless method), seem to provide sufficiently dry forest fuel, with a needle content of about 5–10%. There is a clear correlation between drying and effective loss of needles from twigs, but the loss does not necessarily mean that the needles will remain in the forest. However, needle color (green or brown) is not a strong indicator for a reduction in needle content.Acceptance of the fresh-stacked method would provide opportunities for the development of new technologies, more efficient use of machinery throughout the whole year, reduced costs, shorter lead times and increased amounts of logging residues extracted from each clear-felled area. This is mainly because it would enable extraction at optimal times from a logistical, financial and/or forestry perspectives.Written in English with summary and conclusion in Swedish.
46.	Nilsson, Daniel, et al. (författare) The importance of accurate measurement of comminuted logging residues’ moisture contents for small-scale forest owners 2016 Ingår i: Drewno. - 1644-3985. ; 59:198, s. 99-110 Tidskriftsartikel (refereegranskat)abstract Bioenergy from logging residues is an important contributor to Swedish energysupplies. Thus, accurate measurements of delivered logging residues’ energycontents are very important for both sellers and buyers. Deliveries’ energycontents are highly correlated with their moisture contents, and thus aredetermined in southern Sweden (and elsewhere) by measuring their masses andmoisture contents. There is insufficient knowledge, however, about the variation inmoisture content within and between deliveries, and hence the minimum numberof samples needed to obtain the required precision. Thus, these variations wereexamined in detail in the presented study. Nested analysis of the variance of theacquired data shows that at least nine samples are required to obtain estimates ofa delivery’s moisture content with a 3% margin of error. For high volume trade,such as that between forest companies and the energy-conversion industry,current measurement practices are sufficiently accurate. For private forest ownersmaking single deliveries, however, higher precision is required as inaccuratemeasurements can strongly affect prices.
47.	Phiri, Darius, et al. (författare) Biomass equations for selected drought-tolerant eucalypts in South Africa 2015 Ingår i: Southern Forests, a journal of forest science. - : National Inquiry Services Center (NISC). - 2070-2620 .- 2070-2639. ; 77:4, s. 255-262 Tidskriftsartikel (refereegranskat)abstract In the water-scarce environment of South Africa, drought-tolerant eucalypt species have the potential to contribute to the timber and biomass resource. Biomass functions are a necessary prerequisite to predict yield and carbon sequestration. In this study preliminary biomass models for Eucalyptus cladocalyx, E. gomphocephala and E. grandis x E. camaldulensis from the dry West Coast of South Africa were developed. The study was based on 33 trees, which were destructively sampled for biomass components (branchwood, stems, bark and foliage). Simultaneous regression equations based on seemingly unrelated regression were fitted to estimate biomass while ensuring additivity. Models were of the classical allometric form, ln(Y) = a+x(1)ln(dbh)+x(2)ln(h), of which the best models explained between 70% and 98% of the variation of the predicted biomass quantities. A general model for the pooled data of all species showed a good fit as well as robust model behaviour. The average biomass proportions of the stemwood, bark, branches and foliage were 60%, 6%, 29% and 5%, respectively.
48.	Wimmer, Rupert, et al. (författare) Effects of Reaction Wood on the Performance of Wood and Wood-Based Products 2014. - 1 Ingår i: The Biology of Reaction Wood. - Berlin, Heidelberg : Springer. - 9783642108136 ; , s. 225-248 Bokkapitel (refereegranskat)abstract Compression wood in softwoods and tension wood in hardwoods have properties, which adversely affect its usefulness for wood products. This chapter shows that reaction wood can be associated with many unsuitable wood properties. The results vary due to the fact that definitions about occurrence and severity of reaction wood are scarcely documented. A few properties seem to be even benefitting from the presence of reaction wood: the higher smoothness of compression wood surfaces, better shear strength of compression wood, higher toughness and impact resistance when tension wood is present, lower water uptake and swelling in fibreboards containing compression wood, and higher durability against fungi of compression wood. However, these are outweighed by disadvantages, which is the reason why reaction wood has a bad reputation in industry. The problem with reaction wood is that it is in most cases mixed with normal wood, which leads to non-uniform and more variable properties. This may lead to non-uniform swelling and shrinking, causing distortions, with additional problems of reduced strength and unfavourable surface properties. Wood-based materials such as particle boards or fibreboards are generally less prone to problems associated with reaction wood than solid wood products. With knowledge-based production methods the utilization of different wood types, including reaction wood, might be feasible.
49.	Björdal, Charlotte, 1961, et al. (författare) Correlation between sulfur accumulation and microbial wood degradation on shipwreck timbers 2019 Ingår i: International Biodeterioration & Biodegradation. - : Elsevier BV. - 0964-8305. ; 140, s. 37-42 Tidskriftsartikel (refereegranskat)abstract Archaeological shipwreck timber often contains elevated amounts of sulfur and iron rich compounds, accumulated during the long-term exposure in marine environments. This paper investigates if the accumulation of iron and sulfur is correlated and restricted to areas where microbial wood degradation takes place. Examination of microbial degradation in two pine and four oak samples from three historical shipwrecks situated in the Baltic Sea are carried out by light microscopy. Type, degree and amount of wood degradation by fungal and bacterial processes is compared to results on sulfur and iron accumulation studied by X-Ray Fluorescence (XRF) scanning. The highest accumulation of iron and sulfur is found in the surface layers (0–2cm), where microbial degradation is also most intense. A novel finding is that both decay by erosion bacteria- and soft rot fungi promotes accumulation. Our results also imply that accumulation of inorganic sulfur and iron in archaeological wood involves several different processes which might include solely chemical as well as biogeochemical processes. The processes are different in pine compared to oak and the wood species of the shipwreck timber might therefore have a more important role than previously assumed.
50.	Sandberg, Dick, 1967-, et al. (författare) Crack formation due to weathering of radial and tangential sections of pine and spruce 2006 Ingår i: Wood Material Science & Engineering. - : Taylor & Francis. - 1748-0272 .- 1748-0280. ; 1:1, s. 12-20 Tidskriftsartikel (refereegranskat)abstract The development of cracks and changes in appearance have been investigated on radial and tangential sections of pine (Pinus sylvestris L.) and spruce (Picea abies Karst.) after exposure outdoors for 61 months. The degradation of the sections has also been studied at the micro-level.The annual ring orientation was the most important factor affecting crack development on weathering. After 61 months of outdoor exposure, the tangential sections of spruce had 1.7–2.2 times greater mean total crack length per area unit than the corresponding radial sections. In pine, the total crack length per area unit on the tangential sections was 2.2–2.6 times greater than that on the radial sections. Tangential and radial sections show the same colour change as a result of weathering.Tangential sections have more and deeper cracks than radial surfaces. The cracks on the tangential sections occur frequently in both earlywood and latewood. On radial sections, cracks occur primarily at the annual ring borders, but to a certain extent also in the earlywood.Decomposition of the cell wall takes place in both radial and tangential cell walls and cracks tend to follow the fibril orientation in the S2-layer of the cell wall. The radial cell wall of the earlywood has a large number of pits which are degraded at an early stage.

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