| 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. |
- 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
|
|
| 3. |
- 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.
|
|
| 4. |
- 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).
|
|
| 5. |
- 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.
|
|
| 6. |
- 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.
|
|
| 7. |
- 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.
|
|
| 8. |
- 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.
|
|
| 9. |
- Neyses, Benedikt, 1986-, et al.
(författare)
-
Continuous densification of solid wood – The belt press approach
- 2022
-
Ingår i: Proceedings of the 10th European Conference on Wood Modification. - Nancy : University of Lorraine, Faculty of Science and Technology, Laboratory of Study and Research on the Wood Material (LERMaB). ; , s. 76-79
-
Konferensbidrag (refereegranskat)abstract
- The densification, i.e., transverse compression of solid wood can lead to improvements in the mechanical properties, and this can expand the areas of application for low-density wood species. For the past one hundred years, many efforts have been made to mass-produce densified wood products, but despite being available on the market, they remain niche products with low annual production volumes. One of the main reasons for this is that all available densified wood products are produced in a batch-type process, which limits the achievable process speed and integration into the continuous wood processing chain. For this reason, we propose a continuous surface densification process using a bespoke belt press – similar in principle to those used to produce MDF panels. The belt-press is capable of densifying full-sized wood boards at processing speeds of up to 60 m min-1. The primary belt for densification can be heated to temperatures above 160°C, while a subsequent belt functions as a cooling stage. During the densification process, the belt press can log the pressing forces, moments, and temperature. Preliminary tests with Scots pine specimens of 120 mm in width and 38 mm in thickness resulted in a twofold increase in peak density, after a pressing time of two minutes at 120°C. The resulting density profiles were similar to those obtained in studies using a static hot press. As the belt press can be fed with a continuous stream of boards, it has a higher net throughput than a static hot press. Further studies continue with the aim to evaluate different aspects relevant to the large-scale industrial production of densified wood products.
|
|
| 10. |
- 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.
|
|
| 11. |
- 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.
|
|
| 12. |
|
|
| 13. |
- Ager, Bengt
(författare)
-
Fördjupade studier av det maskinella drivningsarbetets humankvalitet åren kring 2010 : efterskrift till Arbetsrapport 378/2012 vid SLU, inst. för skoglig resurshushållning ”Skogsarbetets rationalisering och humanisering 1900-2011 och framåt”
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I denna efterskrift till SLU Arbetsrapport 378/2012 ”Skogsarbetets rationalisering och humanisering 1900-2011 och framåt” sker en fördjupad granskning av de senaste årens förändring och nuläget i det maskinella drivningsarbetets humankvalitet. Granskningen bekräftar mina utsagor om de enskilda humankvaliteternas förändring som gäller dels försämringar i form av minskade personliga kontakter, ökad prestationspress, mindre variation i arbetet, mer raka tvåskift, längre arbetsresor, försämrad relativ lönenivå samt försämrad framförhållning i planeringen av drivningarna och dels förbättringar i form av bättre förarmiljö och höjd driftssäkerhet hos maskinerna. Granskningen, med viss komplettering av empirin, har också gett möjligheter till nyansering och utvidgning av mina tolkningar. Analysen i denna efterskrift har riktats mera mot helheten i arbetet och två diagnosmodeller har skapats med syfte att nå ökad förståelse av humankvalitetens variation och därmed underlätta inriktningen av förbättringsåtgärder. Den ena diagnosmodellen är en matris där man poängsätter fyra kritiska faktorer i organisationsmiljön – drivningsobjektens storlek och koncentration, arbetsresornas längd, skiftarbetets utformning och kontakten med produktionsledningen. Om organisationsmiljön för ett drivningslag får en låg totalpoäng är risken för vantrivsel och avhopp hos maskinförarna stor. Hög totalpoäng innebär stor sannolikhet för hög arbetsglädje i drivningslaget. Den andra diagnosmodellen identifierar två varianter av ekonomisk situation i den typiska entreprenörverksamheten; som består av en (eller två) maskingrupp(er) (skördare + skotare) där entreprenören kör maskin på heltid. Den ena varianten är en ond cirkel där entreprenören startade verksamheten med stora lån som ligger kvar på en hög nivå på grund av den svaga lönsamheten i verksamheten. Försöken att öka lönsamheten genom att pressa kostnaderna äts upp av kundernas återkommande sänkningar av kubikmeterpriset samtidigt med att man lägger på entreprenören nya uppgifter utan adekvat ersättning. Cirkeln blir lätt en ond spiral, men för den som inte orkar längre och vill lägga ned verksamheten blir lånenivån ett hinder. Den som försöker undvika lånefällan genom att avstå från förnyelse av maskinparken missar den produktivitetsökning som normalt följer med en ny maskin och får i stället arbeta hårdare och längre för att överleva. Den andra varianten är en god cirkel där företaget har en god och stabil ekonomi som medger relativt täta byten av maskiner – med allt bättre prestationsförmåga, förarmiljö och driftssäkerhet - utan att företaget drar på sig stora lån. Företaget tar sig lättare igenom uppkommande problem, ofta beroende på att godcirkelföretaget lättare lockar till sig högpresterande personal. Kopplar man ihop de båda diagnosmodellerna kan man lättare förstå den mycket stora spridningen i entreprenörernas och maskinförarnas inställning till det maskinella drivningsarbetet. Kombinationen av godcirkelföretag och god organisationsmiljö – som troligen ofta hänger samman – bäddar för mycket hög humankvalitet. De företag som rör sig i den onda cirkeln och erbjuds dåliga organisationsmiljöer hamnar lätt i en ond spiral som leder till vantrivsel, personalavhopp och utslagning. Det finns indikationer på att antalet onda cirklar och spiraler ökat bland drivningsentreprenörerna under de senaste två årens lågkonjunktur och att därmed hela drivningssektorn befinner sig i en ond spiral. I denna svacka förlorar sektorn resurser som det blir svårt att remobilisera när konjunkturen vänder.
|
|
| 14. |
- 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.
|
|
| 15. |
- 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.
|
|
| 16. |
- 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.
|
|
| 17. |
- 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.
|
|
| 18. |
- Anerud, Erik
(författare)
-
An alternative supply system for stump biomass - coarse grinding combined with sieving of the produced hog fuel
- 2016
-
Ingår i: International Journal of Forest Engineering. - : Informa UK Limited. - 1494-2119 .- 1913-2220. ; 27, s. 109-114
-
Tidskriftsartikel (refereegranskat)abstract
- Transport costs are one of the major costs in the supply chain of stumps for fuel. Stump parts are bulkyand it is impossible to achieve full tonnages on trucks and trailers even though the load space iscompletely full. The transport economy for stumps is also negatively affected by the large amount ofcontaminants in the loads. Grinding the stumps at the landing and sieving of the produced hog fuel hasthe potential to increase load weights and reduce both the amount of contaminants and the transportcosts. To evaluate such a system a series of studies were made. Results show that coarse grinding andsieving reduced both moisture and ash content in the produced fuel, thus increasing the heating valueper ton delivered fuel and transforming a soil contaminated material to an acceptable fuel. Transportpayloads increased substantially compared to transports of stump parts, but a transport distance of110 km was needed before the coarse grinding system provided lower cost than the standard systemwith transports of stump parts and grinding at the heating plant. Further studies are needed to evaluatethe total energy efficiency in the two systems. Coarse grinding and sieving is a feasible way to increasefuel quality and improve transport economy. However, total costs will in most cases be higher than forthe loose stump system which renders the method preferable only in cases where the sieving processconverts a non-acceptable material into an acceptable fuel.
|
|
| 19. |
- Axelsson, Anna-Lena, et al.
(författare)
-
Att jämföra skogens då med nu
- 2011
-
Ingår i: Miljötrender från SLU. - 1403-4743. ; , s. 3-5
-
Tidskriftsartikel (populärvet., debatt m.m.)
|
|
| 20. |
|
|
| 21. |
- Bergström, Dan, et al.
(författare)
-
Quality and productivity in comminution of small-diameter tree bundles
- 2016
-
Ingår i: International Journal of Forest Engineering. - : Informa UK Limited. - 1494-2119 .- 1913-2220. ; 27, s. 179-187
-
Tidskriftsartikel (refereegranskat)abstract
- Bundling small-diameter trees from thinnings has become a viable technology with the development of the Fixteri harvester-bundler. Several studies have measured the productivity of the machine, however, bundling also influences the whole supply chain. A study was conducted to investigate the quality of chips and productivity of five different conventional chippers and one grinder when comminuting bundles produced of small-diameter trees. The productivity based on dry mass was on average 44.8 tonne per effective working hour (E-0 H-1), and varied considerably between the machines; 1:2.3 being the observed relation between lowest and highest performance of machines. Productivity when comminuting bundles was 1.5-3.2 times higher than normally found in the literature for unbundled (loose) material. The quality of the produced fuel chips varied between machines in dry weight share of particle sizes <3.15 mm from around 5 to 35%. The average size of the chips varied between 5 and 20 mm. The study indicated that productivity and quality of fuel chips are dependent on machine type and the raw material processed. Further investigations should examine different machine systems in designed experiments where e.g. several assortments and operational environments are included.
|
|
| 22. |
|
|
| 23. |
- 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.
|
|
| 24. |
- 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.
|
|
| 25. |
- Chen, Zhi-Qiang, et al.
(författare)
-
Estimating solid wood properties using Pilodyn and acoustic velocity on standing trees of Norway spruce
- 2015
-
Ingår i: Annals of Forest Science. - : Springer Science and Business Media LLC. - 1286-4560 .- 1297-966X. ; 72:4, s. 499-508
-
Tidskriftsartikel (refereegranskat)abstract
- Key message: Strong genetic correlations were observed between Pilodyn measurement and wood density, and between acoustic velocity and MFA. Combination of Pilodyn penetration and acoustic velocity measurements from standing trees can provide reliable prediction of stiffness of Norway spruce for breeding selection.Context: Traditional methods for the estimation of solid wood quality traits of standing tree such as wood density, microfibril angle (MFA), and modulus of elasticity (MOE) are time-consuming and expensive, which render them unsuitable for rapidly screening a large number of trees in tree breeding programs.Aim: This study aims to evaluate the suitability of using Pilodyn penetration and acoustic velocity (nondestructive evaluation) to assess wood density, MFA, and MOE for Norway spruce.Methods: Pilodyn penetration and Hitman acoustic velocity, as well as wood density, MFA, and MOE using benchmark SilviScan were measured on 5618 standing trees of 524 open-pollinated families in two 21-year-old Norway spruce (Picea abies) progeny trials in southern Sweden.Results: Strong genetic correlations were observed between Pilodyn measurement and wood density (rg = −0.96), and between acoustic velocity and MFA (rg = −0.94). Combination of Pilodyn penetration and Hitman acoustic velocity measurements (Formula presented.) obtained from standing trees showed a genetic correlation with benchmark MOE of 0.99. This combined MOE(Formula presented.) had higher selection efficiency for benchmark MOE (92 %) compared to 58–60 % using acoustic velocity alone and 78 % using Pilodyn penetration alone.Conclusion: Combination of Pilodyn penetration with Hitman acoustic velocity provided very high selection efficiency for the three most important quality traits for wood mechanical properties in Norway spruce.
|
|
| 26. |
- Chen, Zhi-Qiang, et al.
(författare)
-
Genetic analysis of fiber dimensions and their correlation with stem diameter and solid-wood properties in Norway spruce
- 2016
-
Ingår i: Tree Genetics & Genomes. - : Springer Science and Business Media LLC. - 1614-2942 .- 1614-2950. ; 12:6
-
Tidskriftsartikel (refereegranskat)abstract
- Adverse genetic correlations between growth traits and solid-wood, as well as fiber traits are a concern in conifer breeding programs. To evaluate the impact of selection for growth and solid-wood properties on fiber dimensions, we investigated the inheritance and efficiency of early selection for different wood-fiber traits and their correlations with stem diameter, wood density, modulus of elasticity (MOE), and microfibril angle (MFA) in Norway spruce (Picea abies L). The study was based on two large open-pollinated progeny trials established in southern Sweden in 1990 with material from 524 families comprising 5618 trees. Two increment cores were sampled from each tree. Radial variations from pith to bark were determined for rings 3–15 with SilviScan for fiber widths in the radial (RFW) and tangential (TFW) direction, fiber wall thickness (FWT), and fiber coarseness (FC). Fiber length (FL) was determined for rings 8–11. Heritabilities based on rings 8–11 using joint-site data were moderate to high (0.24–0.51) for all fiber-dimension traits. Heritabilities based on stem cross-sectional averages varied from 0.34 to 0.48 and reached a plateau at rings 6–9. The “age-age†genetic correlations for RFW, TFW, FWT, and FC cross-sectional averages at a particular age with cross-sectional averages at ring 15 reached 0.9 at rings 4–7. Our results indicated a moderate to high positive genetic correlation for density and MOE with FC and FWT, moderate and negative with RFW, and low with TFW and FL. Comparison of several selection scenarios indicated that the highest profitability is reached when diameter and MOE are considered jointly, in which case, the effect on any fiber dimension is negligible. Early selection was highly efficient from ring 5 for RFW and from rings 8–10 for TFW, FWT, and FC.
|
|
| 27. |
- Chen, Zhiqiang
(författare)
-
Quantitative genetics of Norway spruce in Sweden
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Genetic improvement of solid wood and pulp and paper products related wood quality traits are important to increase productivity and value of Norway spruce plantation in Sweden. To incorporate wood quality traits into Norway spruce tree breeding program, genetic parameters of solid wood and fibre traits were investigated in a large Norway spruce population. 524 half-sib families from two trials tested in southern Sweden were selected to characterise the genetic variation in wood density, microfibril angle (MFA), modulus of elasticity (MOE), radial fibre width (RFW), tangential fibre width (TFW), fibre wall thickness (FWT), fibre coarseness (FC), and fibre length (FL). To rapidly measure stiffness (MOE) of standing trees and accurately measure FL from increment cores, a new non-destructive method for quantifying stiffness and a new algorithm for calculating FL were developed. A combination of Pilodyn and acoustic Hitman measurement was found to predict stiffness of standing tree accurately and the new algorithm using Expectation-Maximization could accurately estimate FL. To improve the estimate of genetic parameters and understanding genotype by environment (G×E) interaction in Norway spruce, spatial analyses were applied to 145 progeny trials and factor-analytic method was applied to 20 half-sib progeny trials. Spatial analysis significantly improved heritability and accuracy of breeding value prediction. Frost damage may be a main driver for G×E interaction for tree height of Norway spruce in southern and central Sweden. Wood quality traits showed higher heritability than growth traits. However, growth traits had highly unfavourable genetic correlations with solid wood quality traits (0.54-0.75) and weakly to moderately unfavourable genetic correlations with fibre property traits (0.11-0.49). In conclusion, selection based on diameter alone would have considerable negative effects on wood quality traits, a negligible or small negative effect on FL, and only a moderate effect on FWT. A selection index combining diameter and stiffness, which would have minimal impact on FL, is recommended for spruce breeding. Adequate economic weights for growth and stiffness traits should be determined for Norway spruce breeding program to maximize economic gain for Norway spruce.
|
|
| 28. |
- Daniel, Geoffrey
(författare)
-
Decay capacity and degradation patterns of Xylaria hypoxylon on different wood species
- 2022
-
Ingår i: Proceedings IRG Annual Meeting. - 2000-8953.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A host of physical and environmental factors may influence fungal decay including the wood substrate, temperature, moisture, oxygen, light, pH, and nitrogen. Understanding the effects of these factors on fungal decay is important for the effective utilization of wood decay fungi in biotechnological processes and for understanding the role of these organisms in global carbon cycling. The ascomycete Xylaria hypoxylon causes white rot of hardwoods, but remains relatively under-characterized. In this investigation, the decay capability of this fungus was studied using beech, hornbeam, oak and pine. Although Xylaria species are considered as causing white rot decay, Type II soft rot erosion was observed on hornbeam, Type I soft rot cavities were noted on beech, simultaneous rot was found on oak and selective rot on pine. Results indicated that both wood species and cell wall chemistry affected morphological decay patterns illustrating the relationships between fungal enzymatic capacity and wood cell wall structure/chemistry.
|
|
| 29. |
- Daniel, Geoffrey
(författare)
-
Fungal Degradation of Wood Cell walls
- 2016
-
Ingår i: Secondary Xylem Biology; Origin, Functions, and Applications. - 9780128021859 ; , s. 131-168
-
Bokkapitel (refereegranskat)abstract
- This chapter outlines the main morphological changes produced in wood cell walls following colonization and decay by white-, brown-, and soft rot fungi capable of the biomineralization of wood’s main structural components, namely, the cellulose, lignin, and hemicellulose. Lesser information is given on mold and blue-stain fungi. The main modes of attack by fungi from the different decay groups are described with examples from light and electron microscopy given. The main types of enzymatic and nonenzymatic systems used by fungi from the different groups are also briefly reviewed with correlation made with the types of decay produced in wood cell walls.
|
|
| 30. |
- Daniel, Geoffrey
(författare)
-
Microscope Techniques for Understanding Wood Cell Structure and Biodegradation
- 2016
-
Ingår i: Secondary Xylem Biology : Origins, Functions, Applications. - 9780128021859 ; , s. 309-343
-
Bokkapitel (refereegranskat)abstract
- Light and electron microscopy have contributed significantly to revolutionize our understanding of wood structure and its biodegradation. Light (bright field, optical, fluorescence, ultraviolet) microscopy remains the dominant type of wood analysis allowing for global and detailed information of native cellular structure and chemistry as well as degraded wood. Light and electron microscopy (scanning and transmission) techniques provide complementary information from global through tissue, cell, subcellular, and suborganelle levels with high spatial resolution not available using other approaches. Conventional scanning and transmission electron microscopy (SEM/TEM) and ancillary approaches (FE-SEM, ESEM, Cryo-SEM, Cryo-TEM, SEM-EDX, TEM-EDX, and rapid freezing approaches) have greatly improved our finite understanding of the structure of wood cell walls and polymers and of the different morphological forms of wood decay described from light microscopy. SEM and FE-SEM have allowed for the three-dimensional structure of wood to be explored and the intimate nanostructure of the microfibrils and microfibril aggregates within cell wall layers to be revealed as well as providing new details on the interaction of microbes and their mechanisms of decay. The advent of electron tomography techniques with FE-TEM should provide intimate high resolution three-dimensional imaging of wood ultrastructure and decay not possible previously. Additional imaging and analysis techniques that have been used to reveal aspects of wood (ultra)structure and chemistry (e.g., FTIR, Raman, XPS, ToF-SIMS, AFM, X-ray microtomography) continue to be developed and applied although the various light and electron microscopy approaches still remain the most widely used and influential. In this chapter an outline will be given on the main microscopy techniques applied for studies on wood (ultra)structure and wood decay with examples and limitations. Emphasis will also be given to sample preparation as this is a fundamental prerequisite for achieving optimal results with all microscopy approaches.
|
|
| 31. |
|
|
| 32. |
|
|
| 33. |
- Daniel, Geoffrey
(författare)
-
The saprotrophic wood-degrading abilities of Rigidoporus microporus
- 2015
-
Ingår i: Silva Fennica. - : Finnish Society of Forest Science. - 0037-5330 .- 2242-4075. ; 49
-
Tidskriftsartikel (refereegranskat)abstract
- Saprotrophic wood-decaying abilities ofRigidoporus microporus (Polyporales, Basidiomycota) syn. Rigidoporus lignosus and the structural alterations induced in wood blocks of Hevea bra-siliensis Muell. Arg were studied. Mass loss of wood blocks was analyzed after 3 and 6 months respectively and the patterns of decay by pathogenic and endophytic isolates of this fungus were investigated using light microscopy. Effects of temperature on growth of the isolates on malt extract agar were also investigated. The R. microporus isolated from a non-H. brasiliensis host caused the highest percentage mass loss (27.2% after 6 months), followed by isolates ED310 (21.1%) and M13 (15.7%), both collected from diseased H. brasiliensis plantations. The isolate initially identified as an endophyte showed very low saprotrophic wood decay capability (4.3% after 6 months). The optimal temperature for growth of the isolates was 30 °C; except for the endophytic isolate which showed highest growth at 25 °C. Wood samples degraded by the R. microporus isolates showed simultaneous attack of wood cell walls, typical of white rot fungi. Results of the study indicate variability in the wood degrading abilities of the isolates and the potential differences in their physiology are discussed. Our findings further support the need for a taxonomical revision of the Rigidoporus genus.
|
|
| 34. |
- De La Fuente, Teresa, et al.
(författare)
-
Cradle-to-gate life cycle assessment of forest supply chains: Comparison of Canadian and Swedish case studies
- 2017
-
Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 143, s. 866-881
-
Tidskriftsartikel (refereegranskat)abstract
- This study took a Life Cycle Assessment (LCA) perspective to model a total of twenty forest supply chains, from seedling production to forest biomass delivery to industry. Four scenarios were analyzed, two in Sweden and two in Canada. Resource and energy consumption, and emissions to air, water and soil of conventional and biomass dedicated supply chains were evaluated and compared.The Swedish supply chains showed a better environmental profile, on average, per oven dry tonne (0Dt) than the Canadian ones in the regions studied. In terms of climate change potential the Swedish biomass dedicated supply chains generated 48.8 kg CO2-eq, 13%, 30% and 38% lower than Swedish conventional, Canadian biomass dedicated and Canadian conventional supply chains, respectively. Sawlogs from final felling in the Swedish biomass dedicated supply chains generated 34.2 kg CO2-eq, the lowest emissions within the roundwood assortments. Concerning the forest fuel assortments in form of wood chips, pulpwood from final felling in the Swedish conventional supply chains, and stump core and long tops from final felling in the Swedish biomass dedicated supply chains generated the lowest emissions: 48.9 kg CO2-eq, 52.3 Kg CO2-eq and 57.8 kg CO2-eq respectively. Transport from forest to industry, harvesting, extraction, chipping, and crushing were identified as hotspots in the forest supply chains. Forwarding versus skidding, chipping and transportation were the processes that differed the most between countries.In both countries, when the supply chains were biomass dedicated the environmental impacts per ODt were lower than in the conventional supply chains. Therefore, integrating forest fuel supply with industrial wood harvesting has the potential to reduce emissions. (C) 2016 Elsevier Ltd. All rights reserved.
|
|
| 35. |
- De La Fuente, Teresa, et al.
(författare)
-
Fuel consumption and GHG emissions of forest biomass supply chains in Northern Sweden: a comparison analysis between integrated and conventional supply chains
- 2017
-
Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 32, s. 568-581
-
Tidskriftsartikel (refereegranskat)abstract
- Forest biomass can be used as source of renewable energy, contributing to mitigate climate change. Currently, forest biomass is one of the most important energy sources in Sweden, accounting for around 20% of the total supply. New demands of forest biomass may be expected due to the European Union energy targets, the previous high oil prices, the energy supply security, and the bioenergy market. However, the supply depends on the intensity of conventional final felling operations. Thus, it is crucial to determine the energy demands of conventional and new forest assortment supply chains and promote those with the highest energy efficiency and least greenhouse gas (GHG) emissions. An attributional life cycle assessment approach was used to evaluate the fuel consumption and GHG emissions associated with the combustion of fossil fuels used in forest operations, transportation and comminution of forest biomass procured via two kinds of supply chains in Northern Sweden: conventional and integrated. The results indicate that most fuel was consumed in transportation processes. The integrated supply chains (in which the harvesting of industrial roundwood is integrated with extraction of forest fuels) are more energy efficient than conventional supply chains, and have the potential to reduce GHG emissions by approximately 13%.Abbreviation: BWT: bundled whole small trees; CTL: Cut-to-length; ET: energy thinning; FF: final felling; FT: first thinning; FU: functional unit; GHG: greenhouse gas; GWP: global warming potential; LCA: life cycle assessment; LR: logging residues; LT: long tops; ODt: oven dry tonne; ORN: ornskoldsvik (industrial location); PCT: pre-commercial thinning; PL: pulpwood; PM(15)h: Productive machine hours including delays shorter than 15min; RS: Rough-delimbed tree sections; SC: stump core; SL: sawlogs; SP: stumps; ST: second thinning; STO: Storuman (industrial location); u.b: under bark; UME: Umea (industrial location)
|
|
| 36. |
- Di Fulvio, Fulvio, et al.
(författare)
-
Integrated supply of stemwood and residual biomass to forest-based biorefineries
- 2016
-
Ingår i: International Journal of Forest Engineering. - : Informa UK Limited. - 1494-2119 .- 1913-2220. ; 27, s. 115-138
-
Tidskriftsartikel (refereegranskat)abstract
- The demand for forest biomass as raw material for a wide range of products in the developing bioeconomy is expected to increase. Along with a constant pressure on forestry to increase its productivity, this development has led to the search for new procurement methods and new assortments. The present study assessed innovative supply chain practices, with a particular focus on the integrated supply of stemwood and residual tree parts. The assortments considered included tree sections, long tops, saw logs with stump cores and small whole trees from thinnings. The assessment included geographically explicit modelling of the supply chain operations and estimation of supply cost and energy use for three industrial locations in Northern Sweden. The innovative supply chains were compared to conventional, separate, harvest of stemwood and logging residues. We conclude that integrated harvest of tops and branches with stemwood assortments, as well as whole-tree harvest in early thinnings, has a significant potential to reduce the supply cost for the non-stemwood assortments. Stump wood generally remains the most expensive assortment. The energy use analysis confirms earlier research showing that the energy input is relatively small compared to the energy content of the harvested feedstock.
|
|
| 37. |
- Eliasson, Lars, et al.
(författare)
-
Effects of Sieve Size on Chipper Productivity, Fuel Consumption and Chip Size Distribution for Open Drum Chippers
- 2015
-
Ingår i: Croatian Journal Of Forest Engineering. - 1845-5719. ; 36, s. 11-17
-
Tidskriftsartikel (refereegranskat)abstract
- Chip size distribution is an important quality variable not only for buyers of forest fuels, but also for chipping contractors as it influences both fuel consumption and productivity of chippers. Studies of disc chippers and of drum chippers with closed drums have shown that increased chip target length increases chipper productivity and decreases fuel consumption per ton of chips produced. For open drum chippers, chip length is partly controlled by the mesh size in the sieve. In order to evaluate how this sieve affects productivity and fuel consumption of chippers, two open drum machines for professional chipping of forest fuels were studied. Small chippers were represented by a Kesla 645, and larger ones by an Eschlbock Biber 92. The Kesla 645 was studied with 25, 50, and 100 mm sieves and the Biber 92 with 35, 50, and 100 mm sieves. With the 100 mm sieve the Kesla chipper produced 14.5 oven dry ton (odt) of chips per effective hour and the Biber 30.0 odt per effective hour. Fuel consumption per odt was 3.0 l for the Kesla and 2.1 l for the Biber. A reduction of sieve mesh size decreased productivity and increased fuel consumption for both machines. Reducing the mesh size decreased the size of produced chips for the Kesla, but not for the Biber. The sieve on the Biber seems to be a safety measure against oversized pieces whereas chip size is, as on a closed drum chipper, mainly controlled by the cut length of the knives.
|
|
| 38. |
|
|
| 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. |
- Escamez, Sacha, 1987-, et al.
(författare)
-
Genetic markers and tree properties predicting wood biorefining potential in aspen (Populus tremula) bioenergy feedstock
- 2023
-
Ingår i: Biotechnology for Biofuels and Bioproducts. - : BioMed Central Ltd. - 2731-3654. ; 16:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Wood represents the majority of the biomass on land and constitutes a renewable source of biofuels and other bioproducts. However, wood is recalcitrant to bioconversion, raising a need for feedstock improvement in production of, for instance, biofuels. We investigated the properties of wood that affect bioconversion, as well as the underlying genetics, to help identify superior tree feedstocks for biorefining. Results: We recorded 65 wood-related and growth traits in a population of 113 natural aspen genotypes from Sweden (https://doi.org/10.5061/dryad.gtht76hrd). These traits included three growth and field performance traits, 20 traits for wood chemical composition, 17 traits for wood anatomy and structure, and 25 wood saccharification traits as indicators of bioconversion potential. Glucose release after saccharification with acidic pretreatment correlated positively with tree stem height and diameter and the carbohydrate content of the wood, and negatively with the content of lignin and the hemicellulose sugar units. Most of these traits displayed extensive natural variation within the aspen population and high broad-sense heritability, supporting their potential in genetic improvement of feedstocks towards improved bioconversion. Finally, a genome-wide association study (GWAS) revealed 13 genetic loci for saccharification yield (on a whole-tree-biomass basis), with six of them intersecting with associations for either height or stem diameter of the trees. Conclusions: The simple growth traits of stem height and diameter were identified as good predictors of wood saccharification yield in aspen trees. GWAS elucidated the underlying genetics, revealing putative genetic markers for bioconversion of bioenergy tree feedstocks. © 2023, The Author(s).
|
|
| 41. |
|
|
| 42. |
|
|
| 43. |
- Fernando, Dinesh, et al.
(författare)
-
The new microscope method of Simons Stain for characterizing mechanical pulps and quantitatively assessing their fibre development at the cell wall level for fundamental understanding of pulp properties
- 2011
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The morphological and chemical characteristics of wood fibre cell walls govern their response to mechanical pulping processes and thereby determine most pulp and paper properties. Information gained at the fibre wall level (e.g. delamination/internal fibrillation (D/IF)) provide important understanding of wood fibre behavior during processing. A new microscopic method, developed by the authors using Simons’ stain (SS) was applied to different MPs of Norway spruce produced during three full-scale industrial trials at Holmen Paper, Braviken, Sweden. Never-dried thermomechanical pulps (TMP) produced during two trials (one with varying refining pressure and specific energy consumption (SEC) and the other for high intensity refining with different segment designs) and pulps refined after chip sulfite pre-treatment were analyzed and statistically evaluated for the degree of D/IF using the new SS method. Results from the SS method indicated that refining pressure, turbine segments, specific energy and high dosage of sulfite treatment significantly induced fibre wall D/IF. In addition, the method statistically compared different pulp types for the degree of D/IF caused by process conditions/treatments and provided useful information regarding pulp fibre development at the cell wall level and thereby rendered important clues on energy efficiency. Keywords: Cell wall ultrastructure; Delamination/internal fibrillation (D/IF); Energy efficiency; Fibre development; Norway spruce; Simons’ stain (SS); TMP
|
|
| 44. |
|
|
| 45. |
- Gao, Jie, et al.
(författare)
-
Effect of thermal modification on the micromorphology of decay of hardwoods and softwoods by the white rot fungus Pycnoporus sanguineus
- 2018
-
Ingår i: Holzforschung. - : Walter de Gruyter GmbH. - 0018-3830 .- 1437-434X. ; 72, s. 797-811
-
Tidskriftsartikel (refereegranskat)abstract
- Thermal modification (TM) of wood at high temperatures can lead to significantly improved decay resistance against white rot (WR) fungi, but little is known about the mechanism of this improvement at the cellular level. As a contribution to this topic, hardwoods (HWs) (ash, beech) and softwoods (SWs) (spruce, fir) were submitted to the Termovuoto (R) TM process at 220 degrees C for 3-4 h (shortly TMW220 degrees c) and were degraded by the WR fungus Pycnoporus sanguineus. The results were studied using microscopy techniques. Decay occurred preferentially via cell wall delignification prior to the removal of cellulose and hemicelluloses. Concerning this effect and fungal colonization, there were no essential differences between TMW220 degrees c and the unmodified reference of all wood species. TMW220 degrees c, however, showed a number of characteristic changes in decay morphology. Narrow and distinct concentric transition zones were observable in decayed fiber and tracheid cell walls, which demark the lignified and delignified regions. Moreover, cell wall separation by preferential delignification of compound middle lamellae (CML) was not seen in decayed tracheids. It can be concluded that the Termovuoto TMW220 degrees c process has an impact on the delignification process of P. sanguineus at the cell wall level, which slows down the decay.
|
|
| 46. |
- Gräns, Daniel, et al.
(författare)
-
Genetic variation and relationships to growth traits for microfibril angle, wood density and modulus of elasticity in a Picea abies clonal trial in southern Sweden
- 2009
-
Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 24:6, s. 494-503
-
Tidskriftsartikel (refereegranskat)abstract
- Genetic variation in wood density, microfibril angle (MFA), wood stiffness (MOE), height, diameter and volume was investigated in a 26-year-old Norway spruce [(Picea abies (L.) Karst.] clonal trial in southern Sweden. Wood quality measurements were performed on 10 mm increment cores using SilviScan. For MFA, mean values of annual rings showed the highest value (30°) at ring 2 counting from the pith, followed by a steep decrease and a gradual stabilization around ring 12 at approximately 14°. MOE showed a monotonic increase from 5 GPa to 14 GPa when moving from pith to bark. High broad-sense heritability values were found for wood density (0.48), MFA (0.41) and MOE (0.50). All growth traits displayed heritability values of similar magnitudes as reported in earlier studies. The generally high age-age correlations between different sections of the wood cores suggested that early selection for wood quality traits would be successful. Owing to unfavorable genetic correlations between volume and MOE, the correlated response indicated that selection for volume only at age 10 would result in a 0.27% decrease in weighted MOE at age 26 for every 1% increase in volume.
|
|
| 47. |
|
|
| 48. |
- Hafrén, Jonas
(författare)
-
Two-photon autofluorescence spectral imaging applied to probe process-effects in thermomechanical pulp refining
- 2011
-
Ingår i: Nordic Pulp and Paper Research Journal. - 0283-2631 .- 2000-0669. ; 26, s. 372-379
-
Tidskriftsartikel (refereegranskat)abstract
- Norway spruce wood pulps were produced in full industrial scale trials at different thermomechanical pulp refining conditions, such as plate gap, housing pressures and energy consumption levels. To investigate the effects of these refining conditions on the lingocellulosic matrix in fines and fibers, we applied high-resolution spectral imaging in a two-photon fluorescence microscope and compared with conventional pulp and paper analyses (strength, freeness etc.). The fluorescence spectra of lignin in native wood and fibers- and fines from pulps showed that spatial- and spectral heterogeneities can be observed using two-photon autofluorescence spectral imaging, and successfully probed on a microscopic level. Moreover, it was shown that wood autofluorescence depends on fiber morphology and becomes red-shifted by increased temperature, but the fluorescence spectrum of TMP long fiber fraction shifted towards blue by increased refining pressure.
|
|
| 49. |
- 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.
|
|
| 50. |
- Hayatgheibi, Haleh, et al.
(författare)
-
Genetic control of transition from juvenile to mature wood with respect to microfibril angle in Norway spruce (Picea abies) and lodgepole pine (Pinus contorta)
- 2018
-
Ingår i: Canadian Journal of Forest Research. - : Canadian Science Publishing. - 0045-5067 .- 1208-6037. ; 48:11, s. 1358-1365
-
Tidskriftsartikel (refereegranskat)abstract
- Genetic control of microfibril angle (MFA) transition from juvenile wood to mature wood was evaluated in Norway spruce (Picea abies (L.) Karst) and lodgepole pine (Pinus contorta Douglas ex Loudon). Increment cores were collected at breast height (1.3 m) from 5664 trees in two 21-year-old Norway spruce progeny trials in southern Sweden and from 823 trees in two lodgepole pine progeny trials, aged 34–35 years, in northern Sweden. Radial variations in MFA from pith to bark were measured for each core using SilviScan. To estimate MFA transition from juvenile wood to mature wood, a threshold level of MFA 20° was considered, and six different regression functions were fitted to the MFA profile of each tree after exclusion of outliers, following three steps. The narrow-sense heritability estimates (h2) obtained for MFA transition were highest based on the slope function, ranging from 0.21 to 0.23 for Norway spruce and from 0.34 to 0.53 for lodgepole pine, while h2 were mostly non-significant based on the logistic function, under all exclusion methods. Results of this study indicate that it is possible to select for an earlier MFA transition from juvenile wood to mature wood in Norway spruce and lodgepole pine selective breeding programs, as the genetic gains (∆G) obtained in direct selection of this trait were very high in both species.
|
|
