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  • 351.
    Schauerte, Tobias
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Lindblad, Fredrik
    ATEA Logistics.
    Flinkman, Matti
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    The Development of Equity Ratios for Firms in the Swedish Industry for Wooden Single-Family Houses2016In: The 70th Forest Products Society annual convention - new horizons for the forest products industry, June 27-29, 2016, Portland, Madison: Forest Products Society, 2016Conference paper (Refereed)
    Abstract [en]

    On the Swedish market for single-family houses, wood traditionally dominates with around 90 % market share. Due to the economic crisis, the number of prefabricated wooden single-family houses decreased from about 12 100 units in 2007 to 4 800 units in 2012. Firms in the industry struggled with a 60 % decrease of order intake. These firms compete with relatively low margins, and many faced economic losses. Such losses negatively affect the firms’ equity ratio, describing the share of assets that are financed by own capital. This negative effect defines the firms’ long-term ability to pay its depths. The longer such an effect lasts, the more it threatens the firms’ future, potentially leading to bankruptcy.

    This study is aiming at describing the development of the equity ratio from 2010 to 2014 for 52 Swedish firms producing wooden single-family houses. This will be done by collecting and analyzing those firms’ annual reports and the required financial numbers.

    The results show on the one hand how an average equity ratio for the whole industry developed within the chosen five-year period. On the other hand, the development of each firm’s equity ratio within that period is mapped, indicating, which firms potentially might face problems if no appropriate actions will be taken.

  • 352.
    Schauerte, Tobias
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Lindblad, Fredrik
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Johansson, Jimmy
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Industry structure and risk positions for wooden single-family house firms in Sweden: evaluating their potential to enter the multi-family house segment2014In: Forest Products Society and World Conference on Timber Engineering joint proceedings, Forest Products Society, 2014Conference paper (Refereed)
  • 353.
    Scheepers, Gerhard
    et al.
    RISE .
    Nilsson, Jonaz
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Johansson, Jimmy
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Mätning av ytspänningar i torkat gran med NIR2017Report (Other academic)
    Abstract [en]

    In sawmilling, a lot of timber properties are measured online in the sorting and grading of dried timber. This may include moisture content, shape, and a host of other parameters. An important wood property that cannot be measured online is drying stresses, although it is an important parameter for many customers. Since the destructive test methods for stress determination are time consuming, no high frequency routine measurement of the internal stresses is done. In literature, there are a few examples of near infrareds (NIR) capability to detect surface stresses along the fiber direction. There is also an example of stress measurements across the grain on a Japanese wood specie during drying, however, these measurements were always done on a tangential surface. It is unknown whether NIR prediction models can predict surface tension and stress measurements across the grain of dried Norway spruce with varying characteristics, i.e. material from different logs, heart- or sapwood, different year ring orientations, etc. If the technique cannot handle the variation in material properties, such as occurs in a sawmill environment, this means that a simple NIR measurement would not be sufficient to predict the surface tension in industry. This study investigated whether surface stresses in mechanically loaded as well as dried spruce samples with varying material properties can be predicted by NIR models. The measurement data from some mechanically loaded samples showed a correlation between the predicted and actual stress values, but many other samples showed no correlation. Moreover, the data for a single sample could show a good correlation, but the prediction could be at an incorrect stress level. As for the dried samples, NIR models were good at separating the conditioned and nonconditioned samples, but had no predictive power concerning the stress level. The models used to predict the stress level in mechanically loaded samples, were also used to predict the stress in the dried samples, but there was no correlation between the measured strain and the predicted stress level. Therefore, it is concluded that there are no clear indication that NIR measurements can be used in an industrial application for predicting the surface stress level of dried Norway spruce boards.

  • 354.
    Scheepers, Gerhard
    et al.
    RISE Research Institutes of Sweden.
    Wiberg, Pär
    Alent Dynamic.
    Johansson, Jimmy
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    A method to estimate wood surface moisture content during drying2017In: MADERAS: Ciencia y Tecnología, ISSN 0717-3644, E-ISSN 0718-221X, Vol. 19, no 2, p. 133-140Article in journal (Refereed)
    Abstract [en]

    A method to estimate the surface moisture content below the fibre saturation point that is a function of the surface temperature, wet- and dry bulb temperatures, equilibrium moisture content, and fibre saturation point was evaluated. The method is based on the premise that the surface temperature is solely influenced by the surface moisture content and the climate that the surface is exposed to. The prediction model contends that the surface moisture content is equal to the fibre saturation point when the surface temperature is equal to the wet bulb temperature, and equal to the equilibrium moisture content when the surface temperature is equal to the dry bulb temperature, with a linear interpolation between those two points. The model thus predicts that the average moisture content of a thin piece of veneer can be predicted with fairly good accuracy. Also, when drying boards in a fast changing climate, e.g. fan reversals in industrial kilns, the surface temperature and surface moisture content should change as abruptly as the climate does. Additionally, the surface moisture content should correlate to the known drying phases, with a consistently high surface moisture content during the capillary phase when the wet line is close to the surface, and a quickly decreasing surface moisture content when the wet line moves into the wood during the transition to the diffusion phase. The prediction model was tested in these three scenarios and the results suggest that the basic premise is reasonable, and that the method is useful for surface moisture content estimation.

  • 355.
    Schyman, Anna
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Photosynthesis response to temperatures – A study of fertilized and unfertilized Picea abies : Fotosyntes i respons till temperatur – En studie av gödslad och ogödslad Picea abies 2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The effect climate change has on forest trees is a large scaled topic. It is to believe that one of the largest threat to the environment today is global warming (IPPC, 2007). The use of fossil fuels seems to be the big threat with its greenhouse gas (GHG) emission and therefore forest is of interest. Forest contributes in several ways. Forest trees work as a renewable source of numerus materials and as it takes up CO

    2 from the greenhouse gasses it gives us oxygen (O2). The important process of photosynthesis, to able production of more trees and creation of more forests, tells us the vitality of understanding the tree physiology to the fullest. The response of photosynthesis to temperature is a central facet of trees’ response to climate change. With its photosynthesis plants play a large role in the carbon cycle as they store the hazardous carbon dioxide helping us humans to deal with problems directly linked to climatic change and in the same time they build up biomass that can be used as a renewable source. To understand, and to find the key, how plants can achieve optimum potential of photosynthesis several observations were made using plant material from fertilized and unfertilized Picea abies. Well acknowledged leaf gas exchange measurements were used to see the limitations of photosynthesis, observing the net CO2 uptake rate (Anet), the maximum Rubisco carboxylation (Vcmax), maximum rate of electron transport for regeneration of RuBP (Jmax) and their unique response to temperatures. For three days observations were conducted at the Slu Asa field research station in Lammhult, Sweden. In addition to gas exchange measurements, nitrogen (N), phosphorus (P) and chlorophyll content was measured in needles of the fertilized and unfertilized P. abies to see if the content somehow made an impact on photosynthetic parameters and the influence nutrients might have on the specific leaf area (SLA). Results from the observations showed that optimum temperature for photosynthesis varies to be by fertilized 22°C and unfertilized 19°C. The net photosynthetic rate responded to the influence by added fertilizers to almost a double, 9.10 μmol m−2 sec−1 than of the unfertilized, 5.36 μmol m−2 sec−1. These results indicate that a fertilized P. abies has a greater potency to capture carbon than of an unfertilized P. abies. The result also reveals the future prospect of adding fertilizer to a P. abies as a potential of growth in biomass as well as a carbon sink when atmospheric CO2 levels rise. There were no great differences in the behaviour between Vcmax and Jmax to the added or non-added fertilized P. abies. Perhaps the fact that given fertilizer contained both nitrogen and phosphorous could have in their combinations influenced the sensitivity of the relationship between them two and therefore also the result. The presence of N and P in the fertilized P. abies affected the concentration of chlorophyll positively, paving the way for photosynthesis, accumulated biomass and possibly for trees defence against abiotic stress factors.

  • 356.
    Shuchan, Pu
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Evaluation of non-destructive test methods for predicting the static bending stiffness and strength properties of thermally modified timber2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Non-destructive technologies have been applied on predicting the stiffness and strength properties of timber for decades. However, these technologies have rarely been investigated on predicting the properties of thermally modified timber. This study was performed to investigate the non-destructive technologies on estimating of the strength and stiffness properties of thermally modified timber. The material that was utilized for study is full-size structural Norway spruce. Twenty-five thermally modified boards were investigated by applying both non-destructive technologies and static bending test; 25 unmodified boards were used as a control group. Timber grader MTG and Sylvatest Trio are two non-destructive tools that were used for the determining the modulus of elasticity (MOE): MTG is an application of resonance frequency technology and Sylvatest Trio is an application of time-of-flight technology (TOF). The results show that both non-destructive technologies provide good results (??2=0.70 from MTG and??2=0.58 from Sylvatest Trio) on estimating the stiffness properties while poor resultson predicting the strength properties of thermally modified boards.The result shows anoverestimation of modulus of elasticity (MOE) from time-of-flight test compared withthe MOEs gathered from static bending test and resonance frequency test for both thermally modified boards and unmodified ones. The stiffness properties of boards after thermal modification reduced slightly (6.5%) compared with unmodified timbers; while strength properties of thermally modified boards decreased (37.5%) significantlycompared with control group.This study is a part of a bigger study performed at Linneaus University by Joran vanBlokland.

  • 357.
    Sjöberg, Samuel
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Förhållandet mellan ultraljudshastigheten och fibervinkeln på stående hybridasp2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Wood anisotropic- and orthotropic properties and structure, entails a certain limitation regarding its final use. Its properties have there an important role, depending on what it will be used. In order to not decompose the material for the full quality determination, necessary alternative methods that can do the job without decomposition. One such method is the acoustic investigation by ultrasonic techniques. The method has been used in a variety of areas, the last few decades, so even in the wood industry. One question asked was whether the method can be used to examine the slope of grain angle under bark of the hybrid aspen. A comparison of an acoustic ultrasonic measurements and a manual measurement with a fiber angle measuring device with respect to the fiber angle, were made. The result was that some connection existed between fiber angle and the ultrasonic velocity. 

  • 358.
    Sjökvist, Tinh
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Coated Norway Spruce: Influence of Wood Characteristics on Water Sorption and Coating Durability2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wood used outdoors is often degraded and discoloured by microorganisms as a natural part of its life cycle, particularly when exposed to high levels of moisture for prolonged times. In this case, the application of a coating (i.e. paint) is an option for increasing the service life of the wood.

    Norway spruce (Picea abies (L.) Karst.) is commonly used for outdoor applications in Sweden. Earlier studies have shown that uncoated spruce heartwood is less prone to moisture sorption in outdoor exposure, resulting in lower moisture content (MC) levels, as compared to sapwood. However, studies related to the above mentioned characteristics are rather limited for coated spruce, especially including the influence of outdoor exposure (i.e. weathering).

    The aim of this thesis is, therefore, to increase the knowledge of how heartwood and sapwood of different densities influence on the durability of coated Norway spruce for outdoor use. Different types of coatings with alkyd-, acrylic-, flour- (calcimine paint), or linseed-oil-based resin were included. The objectives were to study the water sorption (including MC variation) behaviour and crack formation of uncoated and coated heartwood and sapwood of different densities.

    Furthermore was an objective to study the microbial growth on the surface of similar samples of coated spruce in outdoor exposure. The used methods included wetting and liquid permeability experiments, accelerated water absorption (with samples floating freely in water), and outdoor field test. The field method lasted between three to five years and involved monitoring of the MC variation, the crack formation and the microbial growth on the samples.

    The results based on wetting measurements using octane as the adsorbed liquid showed no difference in liquid permeability between the spruce heartwood and sapwood samples of comparable densities, and indicated a similar level of pit aspiration (closure). The common flow path between two cells of conifers occurs through the pits. Still, the sapwood samples had in general a clearly higher water sorption rate than heartwood samples. It could be concluded that the increased sorption was presumably caused by a lowered water surface tension, most likely by a contamination effect of the water by surface-active sapwood extractives rather than differences in morphology of heartwood and sapwood.

    However, no clear difference in water absorption and MC levels was seen between coated heartwood and sapwood in the field study or in the accelerated water absorption study. Thus, it is suggested that a coating hinders the surfaceactive extractives to lower the water surface tension, resulting in a similar water absorption behaviour of coated heartwood and sapwood. The influence of density on water sorption of coated spruce was similarly to uncoated spruce, meaning the low-density samples had a higher MC than the high-density samples in the field tests. Furthermore, a one-year weathering of the coated and uncoated samples caused a larger increase in water sorption of high-density heartwood in the accelerated water absorption study.

    The field study on uncoated and calcimine-coated spruce showed a higher number of cracks on the high-density samples than on the low-density samples. Additionally, within each density group, a larger number of cracks were seen on sapwood samples as compared to heartwood samples. High-density samples with an alkyd- or an acrylic coating also showed a higher number of cracks. As expected, the formation of cracks on the samples increased their water sorption significantly. The microbial growth was higher on sapwood than on heartwood samples with a white coloured alkyd coating.

    The main conclusion is that heartwood and sapwood of different densities influence the water sorption and durability of coated Norway spruce. However, the principles in water sorption of uncoated heartwood and sapwood could not be applied to coated samples. Overall, the results point out that low-density heartwood could be the best material combination to improve the durability of coated spruce in outdoor use. The knowledge acquired in this thesis can enable an increased service life of coated spruce in outdoor use. The increase in service life is achieved by a careful selection of the wood material regarding the proportion of heartwood and to the choice of wood density. As a concluding remark, the role of surface-active spruce extractives needs to be explored, and a follow-up investigation in the context of water sorption is suggested for future research.

  • 359.
    Sjökvist, Tinh
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Blom, Åsa
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Influence of some wood characteristics on the variation of moisture content in outdoor exposed coated Norway spruce panels2016Conference paper (Other academic)
    Abstract [en]

    A field test of coated spruce was exposed outdoors during three years, measuring the influence of wood characteristics on the variation of moisture content in coated panels. Wood samples had following characteristics: fast-grown or slow-grown wood, heartwood or sapwood. Three different film-forming coatings were tested and all samples were exposed above ground on racks. The measured moisture contents were evaluated using the statistical method Principal Component Analysis (PCA). The moisture content of the coated samples was clearly influenced by wood characteristics; fast-grown wood had higher moisture content and higher moisture fluctuation than slow-grown wood in each respective coating system. The choice of coating system also affects the wood moisture content. The result indicates that in order to achieve low moisture content- excluding the effectiveness of coatings, wood characteristics should also be considered.

  • 360.
    Sjökvist, Tinh
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Blom, Åsa
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    The impact of heartwood and sapwood on biological discoloration of a painted surface2016In: Proceedings of the 12th meeting of the Northern European Network for Wood Science and Engineering (WSE): Wood science and engineering - a key factor on the transition to Bioeconomy. September 12-13, 2016, Riga, Latvia / [ed] Bruno Andersons, Arnis Kokorevics, Riga: Latvian State Institute of Wood Chemistry , 2016, p. 137-142Conference paper (Other academic)
    Abstract [en]

    Wood material has advantages, it comes from a renewable source and it is easy to manage. But one disadvantage when used outdoors is biological discoloration of the material. Some impact on the discoloration is the presence of moisture and nutrients, necessary components for the microorganisms to grow and start a colonisation. Samples made of Norway spruce (Picea abies (L.) Karst) heartwood or sapwood coated with two different film forming paints was studied. The paints had a binder formula made of alkyd or acrylate. Additional parameters related to study the influence of moisture content on discoloration were high and low density material, with and without impregnation oil. Outdoor exposure was made during five years in the southern part of Sweden. The samples were hung with 45 degree inclination, facing south direction. Visual differences in biological surface discoloration were observed for samples within the same paint, which could be explained by differences in heartwood and sapwood.

  • 361.
    Sjökvist, Tinh
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Blom, Åsa
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    The influence of coating color, heartwood and sapwood, on moisture content and growth of microorganisms on the surface during outdoor exposure of Norway spruce boards2019In: Journal of Coatings Technology and Research, ISSN 1547-0091, Vol. 16, no 3, p. 819-826Article in journal (Refereed)
    Abstract [en]

    The use of wood contributes to the global transformation into a bio-based community. There are, however, challenges. The growth of mold, rot fungi, and algae on the coated surface is of major concern due to decreased aesthetic service life and shorter maintenance intervals. The colonization of a coated surface requires the presence of spores, nutrients, and a sufficient amount of water. This work studied the influence of using heartwood and sapwood on the moisture content (MC) and growth of microorganisms on the surface of coated Norway spruce boards [Picea abies (L.) Karst.]. The results revealed a relationship of heartwood samples having a lower MC and a lower or equal degree of biological growth on the coated surface than sapwood samples. The relationship was valid through a range of densities (309–548 kg/m3) and two different coating systems based on either an alkyd or an acrylic resin. Furthermore, the choice of coating color (red compared to white) affected the MC as the red-colored samples had a lower MC, combined with no growth of microorganisms.

  • 362.
    Sjökvist, Tinh
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Blom, Åsa
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Utomhusexponering av ytbehandlat trä: Undersökning av trämaterialets påverkan på beständigheten hos en målad granpanel2017Report (Other (popular science, discussion, etc.))
  • 363.
    Sjökvist, Tinh
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Blom, Åsa
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Wålinder, Magnus
    KTH Royal Institute of Technology, Sweden.
    The influence of heartwood, sapwood and density on moisture fluctuations and crack formations of coated Norway spruce in outdoor exposure2019In: Journal of Wood Science, ISSN 1435-0211, E-ISSN 1611-4663, Vol. 65, no 1, p. 1-9, article id 45Article in journal (Refereed)
    Abstract [en]

    The moisture sorption behaviour of wood strongly influences the durability of exterior-coated wood. Wood characteristics are known to influence the water sorption of uncoated wood. Despite this, the majority of the research on coated wood has been focused on the coating properties. This study aims to investigate the impact of heartwood, sapwood and density on the moisture content (MC) and crack formation of coated Norway spruce (Picea abies (L.) Karst.). Boards with film-forming coatings or a non-film-forming coating were exposed outdoors during 3 years. Crack development and the mass of the boards were recorded during this period. Heartwood and sapwood samples showed no differences in MC. Thus, a coating seems to reduce the differences in water sorption behaviour that is present in uncoated heartwood and sapwood spruce. The reduction is probably related to wetting properties and different sorption mechanisms, involving free and bond water diffusion. However, the low-density samples had significantly higher MC levels than the high-density samples. The high-density samples with a non-film-forming coating showed a higher number of cracks than those with lower density. Furthermore, sapwood samples had a remarkably high number of cracks when compared to the corresponding heartwood samples, despite a similar density and MC.

  • 364.
    Sjökvist, Tinh
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Niklewski, Jonas
    Lund university, Sweden.
    Blom, Åsa
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Effect of wood density and cracks on the moisture content of coated Norway spruce (Picea abies (L.) Karst.)2019In: Wood and Fiber Science, ISSN 0735-6161, Vol. 51, no 2, p. 160-172Article in journal (Refereed)
    Abstract [en]

    A protective coating is often used on the cladding of wooden facades to limit the absorption of moisture. Low wood moisture content (MC) is essential to obtain satisfactory durability performance. Wood density is known to influence the water sorption and crack formation of uncoated wood. However, the effect of density on the aforementioned behaviors of coated spruce is not yet fully understood. Six-years of data on the crack formation and the MC variation of outdoor exposed panels are analyzed in this article. The outdoor test was complemented by a subsequent laboratory experiment, wherein the MC variation was monitored at different depths on the board during artificial water spraying. The aim of this research was to increase the knowledge about how wood density and aging affect the water sorption of coated spruce through the crack formation. The results indicated that wood density had an impact on the overall sorption behavior of coated spruce. Low-density spruce contributed to faster water absorption and desorption processes than coated samples with higher density. However, the observed correlation to density was limited to a condition with an intact coating. High-density characteristics contributed to more crack formation, and the density–sorption relationship reversed with a cracked coating. A cracked coating caused a strong local increase in the MC of the wood at the location of the cracks. Weather-exposed replicates without cracks had a higher MC in the core of the board compared with the value beneath the coating. The higher MC is probably due to the water sorption of the uncoated backside of the panel. Such an occurrence raised awareness for future studies to account for multidimensional sorption behavior from all sides of the panel. The local difference in MC also raises awareness for future studies to investigate local MC variations (as opposed to the global average of the panel) in research on the durability of coated wood.

  • 365.
    Sjökvist, Tinh
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Wålinder, Magnus E.P.
    Royal Institute of Technology, KTH.
    Blom, Åsa
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Liquid sorption characterisation of Norway spruce heartwood and sapwood using a muiticycle Wilhelmy plate metho2018In: International Wood Products Journal, ISSN 2042-6445, E-ISSN 2042-6453, Vol. 9, no 2, p. 58-65Article in journal (Refereed)
    Abstract [en]

    A multicycle Wilhelmy plate method was applied to study the water and octane sorption behaviour of small Norway spruce veneers. Dry heart- and sapwood samples of varying density were investigated. The results showed a correlation between the porosity and the sorption of octane for all samples, i.e. a higher wood porosity resulted in higher octane sorption. However, no difference in octane sorption was found between heart- and sapwood samples of similar density. The water sorption behaviour was difficult to interpret, probably due to the influence of surface-active wood extractives. It is suggested that the presence of such extractives, particularly in the sapwood samples, increases the sorption of water due to a significant decrease in its apparent surface tension. Hence, the results indicate that the liquid water sorption of spruce heart- and sapwood is strongly influenced by variations in the extractives content rather than by the micromorphology.

  • 366.
    Sjöqvist, Isabelle
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hur en skotares körsträcka kan påverkas vid olika fuktighetsförhållanden i terrängen2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In all harvesting operations, minimized risks for soil damage combined with short forwarding mileage are desirable in order to achive cost efficient work. This study examined how forwarding mileage are influenced by the time of the year a harvesting operation is conducted. Two scenarios that corresponded to the terrain water conditions during wet and drier periods of the year were created. Twenty harvesting sites were simulated with these scenarios.

    The results showed that the forwarder’s mileage was reduced in the dry conditions, and that even the forwarder’s mileage over wet areas was reduced under these conditions. This means that there is a potential for productivity increase as well as to reduce the risk of soil damage in wet areas.

  • 367.
    Skagersten, Joel
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Inverkan på ekonomi och kvalitet: Vid användande av röntgenutrustning för timmersortering 2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Genom att mäta stockens påverkan på röntgenstrålar skapar röntgenutrustningen en bild av hur stocken ser ut på insidan. Röntgenutrustning bör kunna användas för att tidigarelägga vissa delar av sorteringen. För att avgör om detta fungerade studerades två fall.

    I det första fallet studerades virke som antingen användes till fönsterämnen eller konstruktion. För att avgöra om sorteringen fungerade jämfördes täckningsbidraget från centrumutbytet vid användning av röntgenutrustningen, som ökade med 3,7 % per sågad m3to.

    I det andra fallet skulle röntgenutrustningen användas för att sortera fram stockar med 80 % friskkvist till specialsortimentet. Då ökade andelen godkänt virke med 2,6 % vid automatisk bedömning med samma inställningar. 72 ±9 % av virket godkändes vid den manuella bedömningen.

  • 368.
    Skarin, Johanna
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Privata skogsägares tro på, upplevelse och anpassning av skogsbruket till klimatförändringar2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Climate scenarios for Sweden show that average temperatures could rise by 4-7 degrees by year 2100. Forecasts show that climate zones will shift northward by about 5-10 kilometers every year, which will result in large changes for forestry. The purpose of this study was to answer whether private forest owner's belief in and adaptation to climate change have increased since 2010. Furthermore, to investigate whether private forest owners have experienced climate change in their forestry and if this in turn affects the belief in and adaptation to climate change. A questionnaire was sent to 700 forest owners in Kronoberg County in Sweden. Nearly 20% of those respondents who answered that yes they certainly have experienced any weather or climate conditions which they interpret as a cause of climate change has also responded that they, yes certainly believe that climate change that it affects their forest. 28% of the respondents replied that they had adapted their forestry to climate change. The study showed that the proportion forest owners believing in climate change as well as the proportion adapting forestry to climate change has increased since 2010. There was a relation between belief in climate change mand the degree of adaption. There was also a relation between the perception of climate change and belief in climate change. A correlation was also seen between the experience of climate change and the level of adaption.

  • 369.
    Skog, Lina
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Människors inställning till rovdjur i Gävleborg och Västernorrland2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med arbetet är att undersöka vad befolkningen i Gävleborg och

    Västernorrlands län upplever är bakgrunden till vad som är ett problem kring våra

    svenska rovdjur. I studien visas skillnader i frågor avseende rovdjur mellan olika

    grupper så som jägare, hundägare, kvinna, man, åldersgrupper samt boskapsägare.

    Rovdjuren har en stor inverkan på vårt samhälle och är en viktig del i ekosystemet

    men synen från befolkningen är inte alltid densamma utan skapar även konflikter

    mellan människor och det finns många åsikter kring hur problemet med

    rovdjursstammarna ska kunna lösas. En del riktar kritik mot rovdjursförvaltningen

    och hävdar att de inte medför några konkreta beslut.

  • 370.
    Soelberg, Emma
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Granknytning i medelålders och äldre bestånd i sydöstra Sverige – en myt eller mätbara effekter?2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today we know that 9,5 million hectares of productive forest land in Sweden consists of Norway spruce (Skogsstyrelsen 2011), of which almost 0.2 million hectares are standing on dry land with low moisture content (personal, communication Göran Kämpe, 2015). The problem today in southern Sweden is that Norway spruce is planted on arid lands, because that pine is considered unsafe due to damage on young plants done by wild animals.

    The study investigates if and when growth slows down for spruce on arid lands in south-eastern of Sweden, based on determination of a site index (SI) for a whole rotation. In order to determine SI, increment cores/cutting at different tree height has been conducted. It compares the height growth of spruce stands during the rotation period, on land where the pine had been the natural choice and where the spruce likely suffers from a water deficit. The focus area of this study is if height growth and SI declines with age as an indication of water deficit in older stands. The boundaries are the economic part.

    The result shows that the spruce stands had a considerably higher site index at an early age, compared when it reaches older ages. During the rotation period, it turns out that site index drops twice during the rotation period, when a possible water deficit occurs. Calculations of the site index show that SI of G30 in the young stand but at time for clear-felling, it drops to a G24.

  • 371.
    Soltani, Abolfazl
    et al.
    Shahid Rajee Teacher Training University, Iran.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Taghiyari, Hamid R.
    Shahid Rajee Teacher Training University, Iran.
    Ghaffari, Ehsan
    Shahid Rajee Teacher Training University, Iran.
    Effects of heat-treatment and nano-wollastonite impregnation on fire properties of solid wood2016In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 11, no 4, p. 8953-8967Article in journal (Refereed)
    Abstract [en]

    The effects of nano-wollastonite (NW) suspension impregnation on the fire-retarding properties of heat-treated solid wood of three species (beech, poplar, fir) were studied. Heat treatment was performed at two temperatures of 180 °C and 200 °C. Impregnation was carried out at a pressure of 3 bars for 30 min. The fire properties included ignition time, glowing time, back-darkening, back-splitting, back-firing, and length and width of the burnt area. Both impregnation with NW and heat-treatment generally improved all fire-retarding properties, although not always to a significant level. As a mineral material, NW acted like a physical shield against fire penetration into the texture of wood specimens, thus improving fire properties. Moreover, the high thermal conductivity coefficient of wollastonite increased the thermal conductivity of wood, therefore preventing the accumulation of heat at the point nearest to a piloted flame and contributing to the improvement of fire properties. The chemical degradation of wood cell components caused by heat-treatment further improved the fire properties. Cluster analysis indicated the significant effect of species on fire properties. Significant R-square values were found amongst fire properties related to the spread of fire on the surface of specimens. The combination of thermal modification and impregnation with NW provides suitable fire properties for solid wood.

  • 372.
    Sonne Lehnberg, Ida
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Privata skogsägares uppfattning om FSC- och PEFC-certifiering: att bli och vara certifierad2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med studien var att beskriva och analysera hur Sydveds certifieringsprocess upplevs av företagets virkesleverantörer. Studien genomfördes som en enkätundersökning via post och e-post. De frågeställningar som utgjorde stommen av arbetet handlade huvudsakligen om upplevelsen kring certifieringsprocessen, virkesleverantörernas kunskap om certifiering, motiv till certifiering och hur dessa påverkar upplevelsen av certifieringsprocessen. Fokus låg även på huruvida den geografiska spridningen hade någon betydelse för upplevelsen liksom om virkesleverantörerna upplevde ett behov av en förändring i certifieringsprocessen. Sammanfattningsvis visade resultaten främst på en förbättringspotential gällande återkoppling och kunskap. Det som Sydved rekommenderas att utveckla är olika delar av certifieringsprocessen där tyngdpunkten bör ligga på att få ett enhetligt sätt att jobba på inom organisationen. Hela certifieringsprocessen, från introduktion till revision och återkoppling bör ha tydliga riktlinjer, då kedjan inte är starkare än sin svagaste länk.

  • 373.
    Sparrman, Erika
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Sambandet mellan masurbjörkens (Betula pendula var. carelica) exteriöra struktur och interiöra kvalitét2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Curly birch has a very special and characteristic appearance, which is due to the genetic growth disturbance of the silver birch, which causes rupture in the cambia. This caused the curly birch to become very popular in Swedish family homes throughout the 1990s. Which meant that the Swedish furniture industry demanded curly birch during this period. The most common type of curly birch is the knotted. The purpose of this study was to describe the exteriors and interiors of some selected tree subjects in a cluster of curly birch and to analyze the relationship between them. The quality survey showed that 77% of the tree species surveyed had exterior and interior signs of curly birch formation. 22% lacked exterior characters, 6% lacked interior signs and 6% lacked both exterior and interior signs of curly birch formation. Of the tree species surveyed, 40% fit the category veneers, 27% as knives and 33% were suitable for other handicraft objects. Nature does not always create high-quality trees, even if the material at the outset had those conditions, the most important conclusion of the study.

  • 374.
    Stendahl, Matti
    et al.
    Swedish University of Agricultural Sciences, Uppsala.
    Eliasson, Lars
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Integrated production of semi-finished components in sawmills, part II: Management of internal operations.2013In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 9, no 1, p. 12-30Article in journal (Refereed)
    Abstract [en]

    Recently, several Swedish sawmills have taken over production of components from customers in the furniture, joinery and house-manufacturing industries. The purpose of this study was to identify key factors in management of internal operations for sawmills with this strategy. A multiple case study design, based on face-to-face interviews with Swedish sawmill practitioners and on various forms of secondary data, produced comprehensive research information. Starting integrated production of components is a demanding strategy for sawmills. It requires deep knowledge about the customer and qualified skills in advanced further-processing of sawn wood. The complexity of quality management, production planning and cost calculation increases, and investments in processing equipment and customer relations reduce strategic flexibility. The diverging material flow complicates sawmills' possibilities to economize on scale, and they must instead economize on other factors, such as scope, combined operations and internal control. New tools for production follow-up and control, for production planning, for analysis of product profitability and for strategic partnership analysis are requested by practitioners. But, even if new analysis tools would facilitate better analysis and management of operations, the willingness and ability to innovate and learn among the personnel emerges as a key factor for success.

  • 375.
    Stendahl, Matti
    et al.
    Swedish University of Agricultural Sciences, Sweden.
    McCluskey, Denise
    Swedish University of Agricultural Sciences, Sweden.
    Eliasson, Lars
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Integrated production of semi-finished components in sawmills, part I: External interactions2013In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 8, no 4, p. 253-270Article in journal (Refereed)
    Abstract [en]

    In a changing business landscape, where globalization and new customer requirements create new business opportunities, some Swedish sawmills have taken over the production of components from their industrial customers. In light of the emerging network-centric perspective on business, sawmill managers' perceptions about component customers' operational requirements, customer interaction processes, and their sawmills' offerings are researched and discussed in this article. A multiple case study design, based on face-to-face interviews with Swedish sawmill managers and on various forms of secondary data, produced comprehensive information about sawmills' interaction processes with component purchasing customers. Thematic data coding facilitated the assessment of the research information in relation to the conceptual and empirical findings of previous research. The findings of the study indicate that more process orientation in housing-, joinery-, and furniture-manufacturing implies an opportunity for sawmills to make service-based offerings including not only physical goods, but also administrative services, logistics, and expert advice. The results of the study confirm the network-centric perspective on business where value is created through the interaction between firms. However, noteworthy barriers in the form of process-, culture-, as well as socially related factors at customer firms must be considered.

  • 376.
    Stenudd, Stefan
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Colour Response in Drying of Nordic Hardwoods2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Colour and appearance of hardwood are of great importance for the interiorand furniture industry. The widespread use of transparent surface treatmentand a fashion that prescribe light colour on many species, means that deviationfrom the ideal have considerable impact on the industrial operations. Kilndrying is generally regarded as the process that has the greatest impact on thecolour of Nordic hardwood species. The lack of satisfactory explanation modelsfor many types of discoloration, however, complicates the control of the dryingprocess.This thesis is an attempt to increase the knowledge of which factors thatcontrol the appearance of some commonly found discolorations associated withdrying of beech, birch and oak. The main focus is on convection drying but alsothe influence of timber storage, pre-steaming and press drying has beeninvestigated for individual species. The studies have been conducted ascomparative studies based on design of experiments in which the colour wasdetermined using a colorimeter.Results show that reddish and dark discoloration of beech and birch duringconvective drying is mainly dependent on the temperature and time of exposurewhen the local moisture content exceeds the fibre saturation point. Theconversion of naturally occurring substances in birch into coloured compoundsis not due to active precursors created at high moisture content levels duringthe subsequent drying at low moisture content levels. Interior grey stain inbeech is caused by slow initial drying at low temperatures. Log storage in coldwinter and spring climate does not cause discoloration in beech. Birch becomeslighter when press-dried at high temperatures, resulting in a colour comparableto that of traditionally kiln dried wood. Steaming of oak before kiln dryingreduce the presence of brown discoloration, a general darkening of the woodoccurs at temperatures above 50°C.

  • 377.
    Stenudd, Stefan
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Influence of moisture content, temperature and air humidity during kiln drying on the lightness of Silver birch (Betula pendula Roth.)2013Manuscript (preprint) (Other academic)
    Abstract [en]

    Discoloration of birch wood during kiln drying is a considerable problem for theindustry, since any deviation from the preferred bright whitish colour reduces theusability and value of the sawn timber. This study was conducted in an effort toincrease the understanding of how MC, temperature and air humidity influence silverbirch lightness. The air humidity was represented by the equilibrium moisturecontent (EMC). Within the investigated intervals of 20-70°C and 9-20% EMC, theCIELAB colorimetric responses, were measured at the surface and at depths of 1 and5 mm below the surface. The results showed that lightness reduction was mainlycontrolled by temperature when long as the local moisture content of wood (MC)exceeded the fibre saturation point (FSP). High temperature in combination withhigh EMC levels promote lightness reduction. Transformation of naturally occurringwood constituents into coloured substances takes place within hours and does notappear to be caused by process related precursors. This study showed that visuallydetectable darkening occurred in samples with a local MC exceeding the FSP whenexposed to drying temperatures higher than 40°C in combination with EMC levelsabove 15%.

  • 378.
    Stenvall, Johan
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Stenvall, Andreas
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Faktorers inverkan på stormfällningefter stormarna Gudrun och Hilde: Bestånd som drabbats i norra och södraSverige2015Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    The Gudrun storm felled an estimated 75 million cubic meters while Hilde brought about 3,5million cubic meters. In Götaland and southern Svealand was the most affected species sprucewhile pine was the most affected species in the storm of Hilde, Storumans municipality.Although spruce was the most common tree species in both areas. The aim of this study istherefore to examine the factors that led to this. A literature study to obtain data on the stormGudrun have been performed. A direct method (field observations) and indirect methods(interviews) has been used to obtain data relating to the storm Hilde. In the field observationsvisited ten items, here was investigated; species, typ of stands, altitude and wind exposure.Interviews were conducted with eight landowners, where they were to supply informationabout their views on how they was affected by the storm Hilde and the factors that had animpact. The storm damage from Gudrun showed that all investigated factors had an effect onthe extent. Our interviews and observations show that the same factors apart from the altitudehad an impact.

  • 379.
    Subramanian, Narayanan
    et al.
    Swedish University of Agricultural Sciences.
    Bergh, Johan
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Johansson, Ulf
    Swedish University of Agricultural Sciences.
    Nilsson, Urban
    Swedish University of Agricultural Sciences.
    Sallnäs, Ola
    Swedish University of Agricultural Sciences.
    Adaptation of Forest Management Regimes in Southern Sweden to Increased Risks Associated with Climate Change2016In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 7, no 1, article id 8Article in journal (Refereed)
    Abstract [en]

    Even though the growth rates of most tree species in Sweden is expected to increase in the near future as a result of climate change, increased risks of damage by storms and various pests and pathogens, notably root rot and bark beetles, may also occur. Thus, forest management practices such as changes to thinning regimes, reductions in rotation lengths, and switching to other species (native or exotic) may represent adaptive management strategies to increase the resistance and resilience of Swedish forests to climate change. Clearly, thorough analyses examining the effects of anticipated climatic changes on damage levels, and the potentially relieving effects of possible management adaptations are needed before implementing such changes. In this study, damage caused by storms, root rot and bark beetles (single and in various combinations) under selected climate and management scenarios were simulated in Norway spruce (Pice abies L. Karst) stands. The results indicate that reductions in thinning intensity and rotation lengths could improve both volume production and profitability in southern Sweden. In addition, cultivation of rapidly growing species, such as hybrid larch (Larix × marschlinsii Coaz.) and hybrid aspen (Populus tremula L. × P. tremuloides Michx.), could be as profitable as Norway spruce cultivation, or even more profitable. However, slow-growing species, such as Silver birch (Betula pendula Roth), Downy birch (Betula pubescens Ehrh.) and European beech (Fagus sylvatica L.) indicated low economic output in terms of Land Expectation Value.

  • 380.
    Subramanian, Narayanan
    et al.
    Swedish University of Agricultural Sciences.
    Nilsson, Urban
    Swedish University of Agricultural Sciences.
    Mossberg, Magnus
    Swedish University of Agricultural Sciences.
    Bergh, Johan
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Impacts of climate change, weather extremes and alternative strategies in managed forests2019In: Ecoscience, ISSN 1195-6860, Vol. 26, no 1, p. 53-70Article in journal (Refereed)
    Abstract [en]

    The growth rate of most tree species in boreal forests will increase with changing climate. This increase is counterbalanced by an increased risk of damage due to extreme weather events. It is believed that the risk of storm damage will increase over time, especially if forests continue to be managed as they are today. In this study, a new landscape-level hybrid forest growth model 3PG-Heureka was developed and simulations were performed to predict the damage caused by storm events in Kronoberg county, over a period of 91 years (2010-2100) with different alternative management regimes under various climatic scenarios (historic, RCP4.5 and RCP8.5). The results indicate that damage caused by storm events could drastically reduce the annual volume increment and annual net revenue obtained from forest landscapes if current forest management regimes are used. These problems can be reduced by adopting alternative management strategies involving avoiding thinning, shorter rotation periods and planting alternative tree species. Alternative management strategies could potentially improve annual volume increments and net revenue obtained while reducing storm-felling. Planting Scots pine instead of Norway spruce across the landscape to minimize storm damage is predicted to be less effective than reducing rotation periods.

  • 381.
    Sullivan, Joe
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    How effective are UK policies at addressing factors affecting consumer decisions to carry out energy efficient renovation?2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The UK’s housing stock is among the oldest and least efficient in Europe. 85% of the UK’s existing homes will still be standing and in use in 2050. Improving the energy efficiency of UK housing stock is an essential requirement in order for the UK to meet its 2008 Climate Change Act obligations. Energy efficiency in buildings is the focus of European (EU) policies with the intention of creating a low-carbon economy by 2020. Reducing energy consumption in existing buildings is essential to achieving this. Government policies are the primary mechanism for lowering energy consumption through changing consumer behaviour, promoting low carbon technology and energy efficient renovations of old building stock.The objective of this thesis is to investigate the effectiveness of UK policies at addressing factors affecting consumer decisions to carry out energy efficient renovations. This is with the intention of determining if UK policies are effectively contributing to the government’s long term climate change commitments.Using a theory developed by Parker (2000) as a conceptual framing of policy compliance, this study conducts interviews with consumers in order to analyse their awareness, understanding and perception of UK energy efficiency policies. Therefore, it can be determined how effective policies are at affecting consumer decisions to carry out energy efficient renovations.The thesis informs that consumers are motivated and willing to comply with policies but there are several key barriers preventing them from complying with these policies and therefore adopting energy efficient renovations. Policies are deemed to be somewhat ineffective at affecting consumer decisions to carry out energy efficient renovations.

  • 382.
    Sundberg, Erik
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Nilsson, Rasmus
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Privata skogsägares syn på och användning av skogsbruksplanen.2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sweden is one of the countries in the world that has a great proportion of privately owned forests where up to half of all forests are owned by private individuals. What potential use do they have of their forest management plan? The purpose of this study was to examine whether there was any connection between the knowledge of the forest, the goal of forestry and the use of the forest management plan. A digital survey was conducted in cooperation with Vida, a private saw timber company. The respondents had two weeks to answer the survey and after that the analyses to find out any connection started.

    The results of the study showed that the forest owner had great use of the forest management plan. They were satisfied with it and the main objective of owning forest land was to manage it on to future generations.

    The conclusion of the study showed that there was a connection between the knowledge of the forest, the goal of forestry and use of the forest management plan.

  • 383.
    Sundman, Christopher
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hur kan klimatförändringen påverka skogens tillväxt och omloppstid?: Vad anser forskningen - vad gör skogsägarna!2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    How can the climate change impact forest growth and the production cycle? What does the scientist expect – what are forest owners doing!

    Yes , we can take advantage of the climate change with an increase in forest growth and mitigate the risks with changing forest management plans. It is possible to eventually shorten rotation period beacuse a higher growth is likely in a warmer climate and extended growing season.

    Scientific reports, forests advisors and forest owners are consistent in their view of adaption to climate change. 

  • 384.
    Sunesson, Johan
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    von Mecklenburg, Anders
    Ungskogsgödsling i granskog - potentiell åtgärd för framtidens skogsbruk2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The demand of wood products will increase in the future when fossil-based fuel will be replaced by fossil free fuels. To meet the growing demand in the future, production increasing measurements must have to be done today. One of the most effective measurements, that increases production, is fertilization in young stands of spruce. Such measurements can give increased production of 8-12 m3sk/ha/year and reduce rotation periods by 40- 60 years in northern Sweden and 20- 40 years in southern Sweden. In this report, fertilization of young spruce stands has been studied when the operation has been implemented in a more practical scale. The aim was to compare if production differs when fertilization is implemented in a more practical scale than in previous studies of fertilization. The stands where located in Gullspång and Hällefors and this revision was made in the winter of 2018. The result of this revision showed an increased production of 102% in Gullspång and 210% in Hällefors in the fertilized stands compared to the unfertilized stands at the same locations. This indicate that fertilization of young spruce stands, when it is exercised in a bigger practical scale, is an effective measurement to increase production in Swedish forestry.

  • 385.
    Svalin, Mathias
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Värdehöjande avkap: -Öka värdet genom att kapa bort kvalitetsfel i skogen2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Derome forest´s main task is to provide five sawmills in the Derome Group´s industries with raw material from timber. To increase timber exchange from the forest they want to test value-adding cuts direct in to the forest. Value-adding cuts means that the harvester cuts off quality defects that lowers the value of the tree. Such quality defects is rot, buttress or crook. In this case, Derome forest wants to increase timber proportion, reduce wasted log, better timber quality and less disruptions at their industries. The purpose with this study is to investigate if the concept with value-adding cuts increases the value on individual logs and further increases all harvest. To investigate the value-adding cuts a quantitative method in shape of a field investigation was used to provide different data about the tree when value-adding cuts was applied. Except for the field investigation a program developed by Skogforsk called Virkesvärde was used to analyze the whole logging operation. The study was delimit to esclusively manage tree species used in Derome Group´s sawmills, spruce (Picea abies) and pine (Pinus sylvestris).In those cases where value-adding cuts were applied during the field investigation an average value increase was made with 39 SEK/tree and 35 % on the first stock. There is obvious connections between diameter, timber class and increase of value. A new timber proportion with 42,6 m3fub or 1,4 % was created from the analysis in Virkesvärde for the whole cutting operation. The value increase of the cutting operation was 43 % on the first stock on the trees where value-adding cut was applied. Price lists for different assortments from Derome forest was used in the calculations. In the field investigation there was value increases on lumps up to 18 dm. Only when the quality defects did not disappear the cut was unsuccessful. The result of the study gave a clear answer that value-adding cuts really was a value-adding action.

  • 386.
    Svanfeldt Ohlsén, Anna
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Olika markberedningsmetoders effekt på granens (Picea abies) utveckling 16 år efter plantering med och utan snytbaggeskydd2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In regenerations, soil preparation provides good conditions for plants to survive and grow, and reduces the risk of damage by pine weevil (Hylobius abietis). The aim of this study was to investigate the long-term effect of protection against pine weevil damage and the long-term effect of different soil scarification methods on the number of trees, tree height and the volume production of spruce (Picea abies).

    The soil preparation methods that were compared were mounding, patch scarification and the inverse method. These were compared as well as to, no soil preparation at all. Half of the plants were treated against pine weevil with permethrin. These were evenly distributed in the experiment.

    The study was conducted in the trial area 9284, at SLU's experimental park in Siljansfors, Mora municipality. The trees were 17 years old when measured (16 years after planting) in the autumn 2018. Then tree height, diameter and the height of the green crown was measured. Volume was calculated with volume functions.

    Mounding, the inverse method and patch scarification (in the order mentioned) and pine weevil protection benefited the volume production of the spruce trees, the numbers of trees and tree height. The fact that mounding and the inverse method was so successful in this experiment is probably due to that the soil in Siljansfors is nutrient-poor and moist. High planting points increases the risk of drought.

    Permethrin treatment had a positive effect on volume production and the number of plants, however, there was no significant difference regarding tree height. Soil preparation and permethrin treatment provide lasting long-term effects on production.

  • 387.
    Säll, Harald
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Spiral grain in trees from drought tolerant Eucalyptus species grown on dry land on the west coast of South Africa2015In: Collection of Extended abstractsfor the International Symposium: Silviculture and Management of Dryland Forests, Stellenbosch, South Africa,16-19 March 2015, Stellenbosch University , 2015, p. 87-89Conference paper (Refereed)
    Abstract [en]

    In this project titled “Evaluation of drought resistant tree species to alleviate poverty in arid regions of South Africa” trees from a 20-year old field trial from two sites on the dry west coast area of South Africa were recently evaluated for growth characteristics. The three most promising Eucalyptus species, namely E. gomphocephala, E. cladocalyx and E. grandis × camaldulensis hybrid, for growth characteristics were selected for further evaluation. The objective of the study reported was to investigate between species variability of selected physical and processing properties determining the suitability of these three species for lumber production. It will also be useful for informing tree breeders and silviculturists to identify which properties need improvement through breeding selection or forest management strategies. And in the future results can hopefully be used for selection of species for small farm plantations which may be processed and sold to generate income.

    One of most common reasons for a customer to avoid using wood is the lack of shape stability. There is a clear connection between spiral growth and how twisted the sawn timber will be when it is dried. Depending on the log diameter a grain angle over 3 to 5 degrees will produce sawn wood that will be pronounced to twist. In older softwood trees, the cracks lean mostly to the right. This means that the grain angle is right handed, and the visible cracks create a spiral in an anti-clockwise direction, looking from the base to the top of the tree (Figure 1). In spruce trees, however, the grain angle close to the pith is left-handed, which means that the fibres follow a clockwise spiral up the trunk (Harris 1989).

  • 388.
    Söderman, Robin
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Effekt av gödsling och gallring på mö̈belvirke av furu2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is about the effects of fertilizing and thinning on furniture timber from redwood. Interviews of furniture manufactures have been made and observing of timber from the Swedish fertilizing and thinning trails. The result from the interviews showed which properties that is important for the furniture manufactures and then the result from the observation showed which type of management of the forest that gave the most timber that had those properties. 

  • 389.
    Taghiyari, Hamid Reza
    et al.
    Shahid Rajaee Teacher Training University, Iran.
    Elyasi, Abdollah
    University of Tehran, Iran.
    Doost-Hoseini, Kazem
    University of Tehran, Iran.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Georg August University Gottingen, Germany.
    Correlation between gas and liquid permeability with noise reduction coefficient in insulation boards made from sugar cane bagasse2017In: Bulgarian Journal of Agricultural Science, ISSN 1310-0351, Vol. 23, no 3, p. 674-681Article in journal (Refereed)
    Abstract [en]

    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.

  • 390.
    Taghiyari, Hamid Reza
    et al.
    Shahid Rajaee University, Iran.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Jahangiri, Asghar
    Rabie, Davood
    Effects of Nano-Wollastonite Impregnation on Fire Properties of Some Thermally-Treated Solid Wood Species2017In: Proceedings IRG Annual Meeting, IRG/WP 17-40771, International research group on wood protection , 2017Conference paper (Refereed)
    Abstract [en]

    The effects of nano-wollastonite (NW) suspension impregnation on the fire-retarding properties of heat-treated solid wood of three species (beech, poplar, fir) were studied. Heat treatment was performed at two temperatures of 180 °C and 200 °C. Impregnation was carried out at a pressure of 3 bars for 30 min. The fire properties included ignition time, glowing time, back-darkening, back-splitting, back-firing, and length and width of the burnt area. Both impregnation with NW and heat-treatment generally improved all fire-retarding properties, although not always to a significant level. As a mineral material, NW acted like a physical shield against fire penetration into the texture of wood specimens, thus improving fire properties. Moreover, the high thermal conductivity coefficient of wollastonite increased the thermal conductivity of wood, therefore preventing the accumulation of heat at the point nearest to a piloted flame and contributing to the improvement of fire properties. The chemical degradation of wood cell components caused by heat-treatment further improved the fire properties. Cluster analysis indicated the significant effect of species on fire properties. Significant R-square values were found amongst fire properties related to the spread of fire on the surface of specimens. The combination of thermal modification and impregnation with NW provides suitable fire properties for solid wood.

  • 391.
    Taghiyari, Hamid Reza
    et al.
    Shahid Rajaee Teacher Training University, Iran.
    Tajvidi, Mehdi
    University of Maine, USA.
    Taghiyari, Reyhaneh
    Payame Noor University, Iran.
    Mantanis, George
    University of Thessaly, Greece.
    Esmailpour, Ayoub
    Shahid Rajaee Teacher Training University, Iran.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Nanotechnology for wood quality improvement and protection2020In: Nanomaterials for Agriculture and Forestry Applications: Micro and Nano Technologies / [ed] Azamal Husen and Mohammad Jawaid, Elsevier, 2020, p. 469-489Chapter in book (Refereed)
    Abstract [en]

    Wood is a natural renewable material with unique properties helping mankind to build and develop its communities since the genesis of human on the Earth. Moreover, wood/cellulosic composites provide the opportunity to utilize low-density wood species and agricultural materials that are basically not suitable for structural applications. Although wood is considered irreplaceable, it has some disadvantages narrowing its applications and limiting its service life. These disadvantages mainly include its susceptibility to water and water vapor, biological deteriorating fungi, insects, termites, and marine borers. The present chapter tries to summarize some main areas in which nanotechnology is being used to improve wood and lignocellulosic-based composite panels. Moreover, some new applications and capabilities of this precious natural material are also brought into perspective, areas such as transparent wood, self-cleaning coatings, and smart windows. Though some areas have been thoroughly studied, much potential still exists for further studies and commercialization.

  • 392.
    Tham, Mathilda
    et al.
    Linnaeus University, Faculty of Arts and Humanities, Department of Design.
    Ståhl, Åsa
    Linnaeus University, Faculty of Arts and Humanities, Department of Design. Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hyltén-Cavallius, Sara
    Linnaeus University, Faculty of Arts and Humanities, Department of Design.
    Recipe for contract for careful sharing2019In: Oikology – Home Ecologics: A book about building and home making for permaculture and for making our home together on Earth / [ed] Mathilda Tham, Åsa Ståhl, Sara Hyltén-Cavallius, Växjö: Linnaeus University Press, 2019, p. 89-94Chapter in book (Other academic)
    Abstract [en]

    This is a recipe for how humans and other species can negotiate the sharing in cohabitation. This might be sharing of a home, a neighbourhood, particular spaces, equipment, time, tasks and community.

  • 393.
    Thomasson, Jakob
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Johansson, Nathalie
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Skogsägares attityder till uttag av grot vid slutavverkning i södra Sverige2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Forests have been used as an energy source for a long time. By taking advantage of logging residues at final harvesting, the forest owners contribute with renewable energy that reduces dependence of fossil fuels. This study concerns the attitudes regarding the collection of logging residues. The study was conducted as a survey which was answered by forest owners and employees that work with counseling regarding forestry.

    The survey shows that the major obstacles that gives negative attitudes of logging residues is the concern about the nutrient removal from the forest and damage dealt by machinery. The study demonstrates the importance of knowledge, and the needs to increase the forest owners knowledge about logging residues and its effects.

    A change of attitude concerning logging residues is needed to secure the future collection of logging residues. The impact that attitudes can give is that there will be insufficient quantities of logging residues in the future.

  • 394.
    Toderean, Alexandru Gabriel
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Kansei Engineering Approach: Mapping the correlation between user's subjective perception and design features for dining tables2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Because of the competitive market and high product failure, product development and quality is moving towards a merging of functionality and usability with psychological needs. The interaction with the products creates a need, which can be a decisive aspect for the user when choosing a product. The Kansei approach, also known as Kansei Engineering, aims at converting the psychological needs that influence the subjective perception of the user, into actual design specification, with eight types developed so far. Furthermore, the method implies that, the competitiveness of the product can be enhanced by attaching users’ feelings and aesthetic impressions in term of product attributes, to the product features.This thesis describes how the methodology can be used by implementing Kansei Engineering Type I as a tool to evaluate and map the subjective perceptions of dining tables. The research shows that it was possible to map correlations between the users’ subjective perception and design features. E.g. a dining table that is perceived as solid, has the feature rail/frame and is heavy (>35kg). This can be used as input in user-centred product development. Even if no correlation was possible in some cases, valuable information was gathered that can be used for further analysis. As a continuation of the research, will be to focus on which surface textures is better perceived as natural feeling of wood.

  • 395.
    Trischler, Johann
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Strategic raw material supply for the particleboard-producing industry in Europe: Problems and challenges2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Particleboard was invented to increase the utilization of wood and it soon became an important core material for furniture production. Nowadays, other industries such as the pulp and papermaking industry and the thermal energy recovery industry claim the same type of raw material. This leads to increasing competition and higher prices than in the past when that kind of wood raw material was widely available and of low price. The particleboard-producing industry is therefore seeking opportunities to reduce the competition and ensure the future supply of lignocellulosic raw material for their products.

    The purpose of the work summarised in this thesis was to investigate the strategic supply of lignocellulosic raw materials for particleboard production and to evaluate alternatives for the supply of lignocellulosic raw material for particleboard production.

    To encompass the complex field of strategic raw material supply, several publications have considered different stages along the supply chain. These papers range from empirical studies to practical tests on a laboratory scale. In this thesis, some of the papers are linked together, building the base for the overall results.

    The results show that the task of increasing the supply of lignocellulosic raw material as primary raw material source is limited by several factors, but that improved product design coupled with a suitable recycling concept can greatly increase the availability of lignocellulosic raw material as a secondary source. Alternatively, the use of non-wood plants might be an opportunity to substitute wood as raw material but there are still some problems relating to the particle properties which must be overcome first.

  • 396.
    Trischler, Johann
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hemmilä, Venla
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Sandberg, Dick
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Challenges using annual plants as substitution for wood in particle-board production: Modification of reed canary grass2013In: Northern European Network for Wood Science and Engineering (WSE): Proceedings of the 9th meeting, September 11-12, 2013, Hannover, Germany / [ed] Brischke, Christian & Meyer, Lidia, Hannover: Leibniz Universität Hannover , 2013, p. 104-109Conference paper (Refereed)
    Abstract [en]

    Forecasts show that, already in 2020, the European consumption of wood and wood fibre raw material can be as large as Europe’s combined forest growth increment. An increasing proportion of the forest raw material is expected to be used as fuel for heating, as propellant fuel or to generate electricity. This means an increasingly tight competition for wood between the board industry and the energy-conversion industry and a need for the board industry to find new raw material sources.

     

    High productivity in the boreal regions makes reed canary grass interesting as a raw material for several applications where wood is today the main raw material. One possible application is in board manufacture, e.g. as a substitute for wood in the core of multi-layer particleboards. The properties of reed canary grass must, however be modified to meet the industrial standards for particleboard production and for the mechanical properties of the boards. Alternatively, different adhesives can be chosen.

    The purpose of this paper is to present some pre-treatments and adhesives suitable for use when reed canary grass is used as core material in industrial particleboard production.  An overview of different methods for pre-treatment and optional adhesives that can be used to increase the bonding properties of annual plants in the context of particleboard production is also presented.

     

    The bonding properties have been studied through mechanical tests and through light microscopy studies. Untreated and NaOH-pre-treated reed canary grass in combination with MUF, PVAc, Lignin, and PUR adhesives have been used in the tests.

    The results show that an adhesion suitable for particleboard production can be achieved with a NaOH-pre-treatment of the grass together with melamine urea formaldehyde (MUF), and especially PVAc and PUR adhesive. The adhesive system must, however, be optimized for industrial conditions.

  • 397.
    Trischler, Johann
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Nilsson, Jonaz
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Sandberg, Dick
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Reed canary grass as light-weight core in particleboards2013In: Pro Ligno, ISSN 1841-4737, E-ISSN 2069-7430, Vol. 9, no 4, p. 469-476Article in journal (Refereed)
    Abstract [en]

     Particle boards are an important material for furniture production. In this sector, two tasks have had priority during recent years: to reduce the weight of the panels and to reduce the formaldehyde emission. As the production methods have been more or less the same for decades, these tasks have to be tackled by reducing or replacing the raw material in the board production.

     

    In this study, the possibility of replacing wood with reed canary grass (Phalaris arundinacea L.) to obtain a light-weight particle board has been studied. The boards studied were three-layered with a core of wood/reed canary grass particles and a surface of 100 % wood particles. A protein-based adhesive was tested as an alternative to a UMF adhesive to reduce the formaldehyde emission. Different combinations of densities between 250 and 450 kg/m3 were included in the study and no additional treatments were made to the raw materials.

     

    The results showed poor mechanical and swelling properties of all the tested boards regardless of the design. The main explanation of the poor properties is the poor wetting of the reed canary grass surface by the adhesives. A pre-treatment of the reed canary grass particles with steam, lipase enzyme or alkali is suggested to increase the wettability.

  • 398.
    Trischler, Johann
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. johann.trischler@lnu.se.
    Sandberg, Dick
    Luleå University of Technology.
    Anaerobic digestion of monocotyledons in particleboard production: a concept of process integration to increase substitution of wood raw material2015In: International Wood Products Journal, ISSN 2042-6445, E-ISSN 2042-6453, Vol. 6, no 4, p. 154-164Article in journal (Refereed)
    Abstract [en]

    The purpose of this conceptual study was to introduce a possibility of integrating a surface treatment of monocotyledons by enzymes into particleboard production to provide a substitute raw material to replace wood particles. Because of the greater competition for wood as a raw material for particleboard production, there is increasing interest in monocotyledons as a substitute for wood. Monocotyledons, such as grass or cereal straw, differ from wood mostly in that they have a surface layer of waxes and embedded silica. If particles of monocotyledons are to be used in combination with wood in particleboards they must be modified. Using the concept of anaerobic digestion, it is possible to modify the surface of monocotyledon particles, having methane as a side product and to achieve a process, which leads to greater product diversity. A SWOT analysis was used to evaluate the process.

  • 399.
    Trischler, Johann
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Sandberg, Dick
    Luleå University of Technology, Sweden.
    Monocotyledons in Particleboard Production: Adhesives, Additives, and Surface Modification of Reed Canary Grass2014In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 9, no 3, p. 3919-3938Article in journal (Refereed)
    Abstract [en]

    As a supplier to the furniture industry, the particleboard industry is searching for opportunities to reduce costs, weight, and formaldehyde emissions. One such opportunity is to use monocotyledons such as straw and hemp, as well as grasses like reed canary grass. A major problem when using reed canary grass or other monocotyledons in combination with wood is the difference in their surface properties, leading to poor reactivity and wettability with adhesives such as melamine urea formaldehyde. To this end, either the surface of the particles must be modified in some way, or different adhesives must be used. The purpose of this paper is to present adhesives, surfactants, coupling agents, and pre-treatment methods that can be used in combination with monocotyledons to improve compatibility with wood. Some of the methods have been tested on reed canary grass. The results show a wide range of strength values for the joint between wood and untreated or pre-treated reed canary grass glued with different adhesives, with and without a surfactant and a coupling agent. Isocyanate-based adhesives provided relatively strong bonds, and polyvinyl acetate, acryl, and epoxy adhesives were also effective. The most effective method was pre-treatment followed by adhesives in combination with a coupling agent.

  • 400.
    Trischler, Johann
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Sandberg, Dick
    The application of Steinmann’s and Schreyögg’s concept of competitive strategies to wood production in Europe: a conceptual studyManuscript (preprint) (Other academic)
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