lnu.sePublications
Change search
Refine search result
6789 401 - 426 of 426
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 401.
    Turesson, Anette
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Skyddade områden i Kalmar län - utveckling och resiliens2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The biological diversity of the world has decreased. Sweden has ratified the UN Convention "Convention on Biological Diversity" which aims to increase biodiversity. Formally protected areas in Sweden are national park, national reserve, habitat area and conservation area. Kalmar County follows the national targets where one of the goals is to increase the proportion of protected areas to 20 % of the land area by the year 2020. Climate change is an added stress factor for different species and is seen as one of the most serious threats to biodiversity. To explore the development of formally protected areas in Kalmar County over a period of 20 Years, from 1994 to 2014, the number of areas, its acreage, variability and connectivity has been investigated for the years 1994, 2000, 2005, 2010 and 2014. Analyses have been made of the findings in relation to goals made by the government, current research and the impact of climate change. Facts have been found in literature on the subject and by GIS analysis. The results show that the number of and the acreage of protected areas has increased. The proportion of protected land in Kalmar County during the period increased from 0.65 % to 2.3 %. According to the goals of the government and research on the subject regarding climate change, this is far too low. The variability of habitat has also increased, but according to research and the goals of the government are the different areas too small. An assessment is that the core areas should be on 250 hectares, wich only 5 % of the areas in the County of Kalmar were. The distance between formally protected areas has decreased and the proportion of areas that had direct contact has increased from none to 21.9 % in 2014. Because of insufficient facts and of the big importance of the protected areas surrounding environment, no conclusions can be drawn for connectivity in this study.

  • 402.
    Umoru, Joseph Adejo
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Characteristics assessment of aspen logs used in the production of matches2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Aspen (Populus tremula L.) accounts for about 2% of the total wood stock in Sweden. Sawmills use only a small part (about 5,000 m³fub) of round wood aspen per year. Since there are no Swedish gradings and design values for aspen, no aspen is used for structural purposes. This also applies to other hardwood trees in Sweden. Aspen is mainly used for pulp and paper with a mass consumption of 800,000 m³fub per year of which about 50% is imported. Most imported aspen is from Russia and the Baltics. The other major use of aspen is in match industries. Consumption for matches amounts to approximately 30,000 m³fub per year in Sweden.

    The aim of the research work was to increase knowledge on the wood quality of aspen used in the production of matches. Aspen (Populus tremula L.) logs were collected from two different sites in Sweden and a non-destructive tools weas used to estimate the modulus of elasticity in logs. To measure the dynamic modulus of elasticity (MOEdyn), Fakopp resonance log grader used. Other properties like density and moisture content were measure and were correlated with the MOEdyn values in order to identify the site that has a better log quality. Besides, horizontal and vertical variation of different wood properties were measured and compared within and between trees from two different sites in order to justify the variation of log quality. A total of 20 trees from Askaremåla and Vimmerby, Sweden were felled and used in this study. From each tree, 3 m long logs were sampled from each base, middle and top. After that, non-destructive evaluations were performed in those logs. Besides, 5 cm thick discs were collected in every tree height (base, middle and top) to measure horizontal and vertical variations.

    This study shows that there were differences in MOEdyn between and within trees. It was evident that trees collected from Vimmerby had a better log property than that in Askaremåla. Using non-destructive tools, it is possible to sort out quality logs for the production of Swedish matches.

  • 403.
    Vadiee, Amir
    et al.
    Mälardalen University, Sweden.
    Dodoo, Ambrose
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Jalilzadehazhari, Elaheh
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Heat Supply Comparison in a Single-Family Housewith Radiator and Floor Heating Systems2020In: Buildings, ISSN 2075-5309, E-ISSN 2075-5309, Vol. 10, no 1, article id 5Article in journal (Refereed)
    Abstract [en]

    Floor heating and radiators are two of the most common types of hydronic heating systemsused for space heating in single-family houses in cold climate regions. Notwithstanding, there are fewcomparative studies on indoor temperature distribution and system cost evaluations for radiatorsand floor heating. Furthermore, there are no aligned outcomes in terms of total heat supply fora single-family house with radiators or floor heating. In this study, the eect of building energyeciency level and construction type, including flooring material, on the supply heating demand andtransmission heat losses were studied for both radiator and floor heating systems. For this purpose,a single-family house located in Växjö, Sweden, was modeled as a case study. The heating demandwas supplied with a district heating system with a similar supply temperature at 45 C for both theradiator and floor heating system. A sensitivity analysis was also performed to assess the eect offlooring configurations on the annual supply heating demand for both conventional and passiveversions of the case-study building. The results showed that the radiator-integrated building had alower supply heating demand in comparison with the floor heating-integrated buildings. Based onthe sensitivity studies, the flooring material did not have a significant influence on the supply heatingdemand and on the transmission heat losses in the case of the radiators. The supply heating demandwas only reduced up to 3% if the flooring U-value was improved by 60%. The results also showedthat refurbishment in a standard conventional building with a radiator heating system based on thepassive criteria led to a 58% annual energy savings, while this amount for a building with a floorheating system was approximately 49%.

  • 404. Valai, A
    et al.
    Birbilis, D
    Karageorgos, A
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Estimation of properties of recovered paper used for the production of corrugated board2015Conference paper (Refereed)
    Abstract [en]

    The objective of this paper was the estimation of corrugated board mechanical properties based on the fiber characteristics from recovered paper and some physical properties (mainly grammage and thickness). Two kind of papers (liners and flutings) used for corrugated board production in Greece were examined. After the experimental determination of a plenty of variables, linear regressions were developed among those variables. Regressions led to some linear models with significant correlations between mechanical properties and fiber characteristics or physical properties (grammage and thickness). For the recycled paper of the liners category, significant correlations were observed considering tensile strength, tearing strength and zero span strength. For the recycled paper of the flutings category, significant correlations were observed considering compression strength and tearing strength

  • 405.
    Vallin, Monika
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Landsbygdsprogrammet för ökad areal ädellövskog: utvärdering av biologiskt resultat och markägares inställning2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Rural Development Programme (LBP), which was financed by the EU, included assistance to landowners to "increase the area of breadleaved forest." The purpose of the aid was to preserve and improve the conditions for biodiversity. Swedish Forest Agency was responsible for the financial support. The purpose of this study was to evaluate the biological results of the plantations made with financial support (from LBP), to find out how the landowners perceived the financial support ,to what extent Swedish Forest Agency contributed to the landowners interest in their plantations, and if there is a relationship between the biological result and the landowners,  interest and involvement.  Out of 31 investigated plantations 71 % was considered to be approved according   the study's definition and, 16 % was considered approved and successful. The majority of the landowners considered that the LBP support had a significant influence on the choice to plant broadleaved trees. Swedish Forestry Agency contributed mainly to the increased interest by the financial support. Compared to all landowners, the proportion of landowners with approved plantation was larger that had the goal to favour a good enviroment, that earlier actively had promoted deciduous forest, considered the extent of silvercultural measures to be as expected, and that intended to broaden their range of products from the forest.   

  • 406.
    van Blokland, Joran
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Olsson, Anders
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Oscarsson, Jan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Bending properties and strain fields around knots in thermally modified timber2018In: / [ed] Jos Creemers, Thomas Houben, Bôke Tjeerdsma, Holger Militz and Brigitte Junge, 2018Conference paper (Refereed)
    Abstract [en]

    Thirty-two (32) boards of Norway spruce with cross-sectional dimensions of 145×45 mm2 were first tested non-destructively in a four-point static bending test, were then thermally modified according to the ThermoWood® process, and were finally tested destructively in the mentioned test set up. For one of these boards, the 2D strain fields occurring due to pure bending were recorded, both before and after thermal modification, over the surface of a knotty part of the board using a non-contact optical deformation measurement system. The objectives were to get more insight into the static bending behaviour of thermally modified timber (TMT), specifically with regard to the local and global modulus of elasticity (MOE) and their respective relationship to bending strength, and the strain development around a cluster of knots. The bending strength was significantly reduced by thermal treatment, whereas the effect on the MOEs was limited. Linear regression analyses demonstrated that bending strength of TMT can be predicted by employing stiffness as indicating property. Strain field measurements showed that at the examined levels of loading the quantity and distribution of strains in a knotty area were not influenced by thermal modification. It was therefore suggested that the influence of thermal modification on global stiffness, as well as on local stiffness around knots, is limited.

  • 407.
    van Blokland, Joran
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Olsson, Anders
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Oscarsson, Jan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Källander, Björn
    Swedish Wood, Sweden.
    Evaluation of non-destructive test methods to predict bending properties of thermally modified timber2018In: 2018 World Conference on Timber Engineering (WCTE), August 20-23, 2018, Seoul, Republic of Korea, World Conference on Timber Engineering (WCTE) , 2018, p. 8-Conference paper (Refereed)
    Abstract [en]

    Thermally modified wood is available through a number of manufacturers in Europe on today’s market for interior and exterior building products. Thermal modification of wood allows for improvement of dimensional stability and durability, but a considerable decrease in strength properties occurs. Despite this loss in strength, thermally modified wood shows potential to be further exploited in structures exposed to loading. For such applications, accurate prediction of its static bending behaviour is essential. This paper studies the applicability of two different non-destructive test (NDT) techniques in estimating the bending properties of thermally modified timber (TMT). The study was done on 100 Norway spruce logs. One hundred (100) boards (i.e. one from each log) were thermally modified and the mirrored 100 boards were used as controls. After modification, resonance-based and time-of-flight measurements of axial wave velocity were carried out. Subsequently, all 200 boards were bent to failure following European standard EN408. This study shows that although TMT has a lower bending strength than unmodified timber, predictions of bending strength and stiffness using the NDT techniques are possible and with sufficient accuracy. The resonance-based method gave better predictions of the bending properties of TMT in respect to time-of-flight method.

  • 408.
    van Blokland, Joran
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Olsson, Anders
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Oscarsson, Jan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Prediction of bending strength of thermally modified timber using high-resolution scanning of fibre direction2019In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 77, no 3, p. 327-340Article in journal (Refereed)
    Abstract [en]

    The market share of thermally modified wood (TMW) has increased in Europe during the past few years as an environmentally friendly and durable building product. However, TMW products of today are not permitted for use in structural applications, because the reduction in strength that is caused by thermal treatment cannot be accounted for. The purpose of this paper was to investigate the bending properties of thermally modified timber (TMT) of Norway spruce, and to explore possibilities to predict the bending properties of TMT. A sample of 100 boards from a 2X-log sawing pattern of 100 logs was thermally modified according to the ThermoWood® process, while the mirror 100 boards served as an unmodified control sample. Two non-destructive methods were employed: (1) a novel method based on scanning of fibre directions to obtain the lowest edgewise bending modulus of elasticity (MOE) along a board, and (2) a conventional excitation method to determine the first axial resonance frequency used to calculate the axial dynamic MOE. Finally, the boards were bent to failure according to European standard EN 408. Despite the fact that bending strength was reduced by 42% due to thermal treatment, the type and location of failure in TMT remained related to the presence of knots. Prediction of bending strength based on local fibre direction and axial dynamic MOE, gave coefficients of determination of 0.51 for the thermally modified boards and 0.69 for the control boards, whereas axial dynamic MOE alone gave 0.46 and 0.57, respectively. These results indicate that although Norway spruce TMT has lower bending strength compared to unmodified timber, predictions of the bending strength can be made with good accuracy.

  • 409.
    Verner, Jörgen
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Karlsson, Mårten
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Tillväxtökning vid fastgödsling av granungskog2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Swedish forest takes up and stores 60 million tons of CO2 every year. Which is a great climate benefit. Fertilization of forest results in a growth increase beacuse of the added nutrients supplied to the trees. This leads to an increased amount of needles that can produce a higher photosynthesis.

    The purpose of this report has been to examine the possibility of growth increase of norway spruce (Picea abies) with frequency fertilization in young stands. Earlier studies have shown that this is an efficient way to increase the stemwood production. The study has one hypothes, the growth increase in frequency fertilized young stands results in a yearly growth increase of 10 m3 per hectare compared to unfertilized stands.

    The material of this study is prepared from assessments from trials in Tranemo and Toftaholm in southern Sweden. The results have been compared to data from earlier assessments in the trial stands. Tranemo and Toftaholm is fertilized six times since 2003. The fertilizer dose is optimized after a needle analysis before every fertilizing occasion.

    The results show that the volume, diameter, basal area and individual stem volume is higher in the fertilized areas than in the unfertilized areas for both Toftaholm and Tranemo. The growth increase at the fertilized areas has increased significant compared with the unfertilized areas. The growth increase at the fertilized areas is 24-25m3 per hectare and year. The growth increase at the unfertilized areas is about 15m3 per hectare and year.

    Fertilization of young stands results in a high growth and shortens the rotation period considerably, the trees reach higher dimensions in shorter time. This study indicates that the number of stems per hectare has an impact on the growth increase in fertilized stands.

  • 410.
    Vestergaard, Kristofer
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Askevik, Dennis
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Rätt björk på rätt mark: Visuell identifiering av naturligt föryngrad björk2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The silver birch (Betula pendula Roth) and the downy birch (Betula pubescens Ehrh) are the most common broadleaved species in Swedish forests. Both species have a lot in common in appearance and are often misleadingly referred to simply as ”birch”. They have however different requirements and possibilities to grow on different sites. Downy birch grows well on moist and wet sites thanks to the fact that its roots are adapted to these type of environments. Silver birch has on the other hand the ability to grow on dry sites. Both species prefer soil moisture class somewhere in between wet and dry.   To be able to promote the correct birch species on each site, it is important to identify the two species during the clearing process. Both buds and shoots are characteristic for each species why those parts can be used to separate them. Buds from silver birch are pointy shaped and those from downy birch are round shaped. When it comes to shoots the silver birch has nubby shoots and the downy birch has hairy shoots.  The aim of this study was to a) investigate the occurrence of each of the two birch species on sites with different soil moisture class, b) investigate if it was possible to visually identify each species during clearing with a clearing saw and c) to find out if and how the height of the stand influenced the possibility of species identification. This study shows that it is possible to identify the two species. It is however important to start the clearing process at an early age, since the parts of the tree used for identification otherwise will grow beyond sight.  This is particularly important on moist sites, where both birch species regenerate willingly. In the long run, downy birch will have higher ability to develop high quality timber on these sites. In order to do that, the right stems must be chosen at each clearing occasion. It is important to start the clearing process at an early age, since the characteristic parts of the tree otherwise will grow beyond sight.  Keywords

  • 411. Voulgaridis, E
    et al.
    Karastergiou, S
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Passialis, C
    Kortsalioudakis, N
    Koutsianitis, D
    Foti, D
    Voulgaridou, E
    Effect of laser drilling on the mechanical properties and impregnation of fir and spruce wood2015Conference paper (Refereed)
  • 412.
    Voulgaridis, Elias
    et al.
    Aristotle University, Greece.
    Passialis, Costas
    Aristotle University, Greece.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Foti, Dafni
    Aristotle University, Greece.
    Voulgaridou, Eleni
    Aristotle University, Greece.
    ΠΑΡΑΓΩΓΗ ΚΑΙ ΙΔΙΟΤΗΤΕΣ ΠΕΙΡΑΜΑΤΙΚΩΝ ΠΛΙΝΘΩΝ ΕΣΩΤΕΡΙΚΗΣ ΤΟΙΧΟΠΟΙΙΑΣ ΑΠΟ ΓΥΨΟ ΚΑΙ ΑΝΑΚΥΚΛΟΥΜΕΝΑ ΥΛΙΚΑ ΞΥΛΟΥ ΚΑΙ ΕΛΑΣΤΙΚΩΝ ΟΧΗΜΑΤΩΝ: [ Production and properties of experimental bricks for interior walls from gypsum and recycled materials of wood and rubber ]2017In: ΠΡΑȀΤǿȀΑ : 18ου Πανελλήνιου Δασολογικού Συνεδρίου : “Η Ελληνική Δασοπονία μπροστά σε σημαντικές προκλήσεις: αειφορική διαχείριση δασών, δασικοί χάρτες, περιβαλλοντικές τεχνολογίες – δικτύωση και προστασία φυσικού περιβάλλοντος”: & International Workshop : “Information Technology, Sustainable Development, Scientific Network & Nature Protection” : 8-11 Οκτωβρίου 2017, ΕΔΕΣΣΑ ΠΕȁȁΑΣ, Περιοχή Βαρόσι, Hellenic Forestry Society , 2017, p. 315-323Conference paper (Refereed)
    Abstract [en]

    Τhe manufacturing and testing of gypsum bonded solid bricks with wood chips from particleboard production residues and rubber and textile fibers from waste tires was investigated. The recovered rubber and wood materials were mixed in gypsum/water solutions for the fabrication of standard solid bricks with six holes by using appropriate molds. After drying, the compressive strength, the thermal conductivity, the air-flow resistance, the sound absorption coefficient and the emissions of volatile organic compounds (VOC) of the bricks were determined. The compressive strength of solid bricks was much greater than that required in interior walls. The bricks showed a better thermal insulation than both the extruded and pressed house bricks but lower than the insulating bricks. Emissions of volatile organic compounds of bricks were at acceptable levels according to regulations for construction products. The sound absorption coefficient of the solid bricks was 0,72 for the frequency of 1 kHz and decreased with increasing frequency. In addition, information on the raw materials and production cost are given.

  • 413.
    Wallemyr, Matilda
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Kroon, Maja
    Linnaeus University, Faculty of Technology.
    Ädellövskogslagens påverkan på skogsägare och arealen ädellövskog2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    De ädla lövträden har genom historien varit värdefulla för Sverige och det har funnits lagstiftning om dessa sedan 1200-talet. Syftet med denna studie var att undersöka de privata enskilda skogsägarnas uppfattning om ädellövskogslagen och om den hämmar nyetablering av ädellövskogsbestånd. I denna studie har två metoder använts för att belysa frågeställningarna ur olika perspektiv: enkätundersökning till skogsägare och intervjuer med utvalda personer ifrån skogsnäringen. Enkätrespondenternas huvudskäl till att inte vilja anlägga en ny ädellövskog var ekonomi och ädellövskogslagen. Troligtvis behövs det en lagstiftning för att skydda arealen med ädellövskog men för att skapa ett intresse för att nyetablera ädellövskog hade det lagliga skyddet behövts göras mer flexibelt samt att kunskapsmässigt stöd hade erbjudits.

  • 414.
    Wallertz, Kristina
    et al.
    SLU.
    Malmqvist, Cecilia
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    The effect of mechanical site preparation methods on the establishment of Norway spruce (Picea abies (L.) Karst.) and Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) in southern Sweden2013In: Forestry (London), ISSN 0015-752X, E-ISSN 1464-3626, Vol. 86, no 1, p. 71-78Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to gain a deeper knowledge of the effects of mechanical site preparation on the survival and growth of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and Norway spruce (Picea abies (L.) Karst.) seedlings in southern Sweden. The experiment was conducted on a fresh clearcut at the Asa experimental forest (57° 10′ N). The effects of five different site preparation treatments were investigated: control, patch, mound, invert and mix. In each treatment, 40 seedlings of Norway spruce and 40 of Douglas fir were planted in each of four blocks. Site preparation had little or no effect on the survival and growth of Norway spruce: only a few seedlings died during the first 2 years. For Douglas fir, however, all site preparation treatments increased survival compared with the control, where mortality was high. The most intensive soil preparation treatment, mix, significantly increased root growth and total biomass. Pine weevils caused more severe damage to Douglas fir seedlings than to Norway spruce and targeted different locations in the two species, causing comparatively more damage to the leading shoots of Douglas fir seedlings.

  • 415.
    Wang, Xiaodong Alice
    et al.
    Luleå University of Technology.
    Björnberg, Jonathan
    Luleå University of Technology.
    Hagman, Olle
    Luleå University of Technology.
    Ahmed, Sheikh Ali
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Wan, Hui
    Mississippi State University, USA.
    Niemz, Peter
    Swiss Federal Institute of Technology in Zurich, Switzerland.
    Effect of Low Temperatures on the Block Shear Strength of Norway Spruce Glulam Joints2016In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 11, no 4, p. 9638-9648Article in journal (Refereed)
    Abstract [en]

    The block shear strength of Norway spruce (Picea abies (L.) Karst.) glulam joints was tested under low temperature. Glulam samples were glued with the three of the most common outdoor structural adhesives. The cold temperatures tested were 20, −20, −30, −40, -50 and −60 °C. Within the temperature test range, the block shear strength of the glulam joints was resistant to the effect of temperature. As the temperature decreased, the joints’ block shear strength did not show any significant change. In most cases, phenol-resorcinol-formaldehyde (PRF) adhesive yielded the strongest block shear strength, while melamine-formaldehyde (MF) adhesive yielded the weakest block shear strength. Melamine-urea-formaldehyde (MUF) adhesive yielded similar results to those of MF adhesives for all temperatures tested. The block shear strengths of the glulam joints with PRF, MUF and MF adhesives were not sensitive to temperature change. The results indicated that PRF, MUF and MF adhesives are stable for outdoor structural engineered wood construction in cold climate. The results also suggest that the SS-EN 14080 (2013) standard for the block shear method may not be the proper standard for testing differences in shear strength at different temperatures. The EN 302-1 (2011) standard could be more suitable for this purpose.

  • 416.
    Wessels, CB
    et al.
    University of Stellenbosch, South Africa.
    Crafford, PL
    University of Stellenbosch, South Africa .
    du Toit, B
    University of Stellenbosch, South Africa.
    Grahn, T
    Innventia, Sweden.
    Johansson, Marie
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Lundqvist, S-O
    Innventia, Sweden.
    Säll, Harald
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Seifert, T
    Univesity of Stellenbosch, South Africa.
    Lumber properties of three drought tolerant eucalyptus species grown in arid regions of south africa2015In: IUFRO Symposium: Silviculture and Management of Dryland Forests,, 2015Conference paper (Other academic)
  • 417.
    Wessels, CB
    et al.
    University of Stellenbosch, South Africa.
    Crafford, PL
    University of Stellenbosch, South Africa.
    DuToit, B
    University of Stellenbosch, South Africa.
    Grahn, T
    Innventia AB, Stockholm.
    Johansson, Marie
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Lundqvist, S-O
    Innventia AB, Stockholm.
    Säll, Harald
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Seifert, Thomas
    University of Stellenbosch, South Africa.
    Variation in physical and mechanical properties from three drought tolerant Eucalyptus species grown on the dry west coast of Southern Africa2016In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 74, no 4, p. 563-575Article in journal (Refereed)
    Abstract [en]

    Southern Africa, and specifically its western parts is dominated by low rainfall areas, and it is expected that the rainfall in most of these parts will in future decrease further due to climate change. Woodlots of fast-growing, non-invasive tree species can provide the opportunity to produce wood and release the pressure on natural woodlands, while creating much needed income to inhabitants. Over the last two decades several trials of Eucalyptus species that could potentially withstand arid conditions were established on the South African west coast. The three most promising genotypes according to their volume growth were selected among 46 pure and hybrid species from two 20-year-old trials for further evaluation. These included 10 Eucalyptus grandis × Eucalyptus camaldulensis hybrid trees, 9 Eucalyptus gomphocephala trees, and 9Eucalyptus cladocalyx trees for a total of 28 trees. The objective of the study reported here was to investigate the within-tree and between species variability of selected physical and processing properties determining the suitability of these three species for lumber production. The density, microfibril angle, spiral grain angle, MOE, MOR, radial and tangential shrinkage, twist, bow, splitting, and collapse were measured in a radial and longitudinal gradient. Valuable insights were gained which could provide decision support for planting, processing and further research on these species when grown in arid conditions. The E. grandis × camaldulensis hybrid was inferior in terms of most relevant properties to the other two species evaluated. The main shortcoming of both E. gomphocephala and E. cladocalyx was the high levels of twist in lumber.

  • 418.
    Wetterskog, Robert
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Somatiska embryogenes-plantors överlevnad och höjdtillväxt vid fyra ljusförhållanden2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Somatiska embryogenes är en mikroförökningsmetod som med hjälp av tillväxtreglerande medel får en växtdel att bilda skott och rötter i ett speciellt odlingssubstrat sterila förhållanden. Kunskapen vad gäller förutsättningar för groning och plantetablering efter detta laboratoriestudium är dock begränsad. I denna studie undersökte hur två kloner av SE-groddar av gran etablerade sig i olika ljusförhållanden avseende våglängd och intensitet i fyra växtmiljöer. Etableringen bedömdes utifrån plantornas överlevnad och höjdtillväxt. Vid sista inventeringstillfället var 62 SE-plantor vid liv och 18 plantor var döda. Ingen signifikant skillnad kunde påvisas i överlevnad mellan de olika växtmiljöerna, inte heller mellan klonerna i respektive miljö eller oberoende av miljö. Signifikant skillnad i höjdtillväxten mellan klonerna kunde påvisas inom alla växtmiljöer, men inte mellan växtmiljöerna oberoende av klon. Det fanns en tendens att ljusförhållanden med en ljusintensitet på 100 μmol och rött ljus inom våglängderna 610-760 nm gav bäst etablering för SE-groddarna. Studien visade också att det var skillnad i etablering mellan de två kloner som användes.

  • 419.
    Wickström, David
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Logistical timber yard optimization and customization: A case study of beneficial changes to industrial flow, capacity and volume2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The progression of wood processing in Swedish saw mills is growing in a rapid pace which pushes internal resources to the limit. This calls for new and innovative ideas to further the capacity of the production to satisfy both requirements as well as demands. Logistics is a key factor in these processes which can both hide problems as well as solutions that could benefit production.

     

    The objective of the study is to research the current timber yard model as it doesn’t suffice the demand, and instead present alternative ideas that will. The methods to do so are a collection of interviews, literary researches and a case study. Alternative models are generally presented in regards to volume capacity but also machine capacity, time and economic factors.

     

    The results show the inefficiency of the current model with insufficient volume capacity of logs, and where unnecessary hauling between two yards have costly outcomes. Suggested model increases the total yard volume from 15 000 m³ to about 25 176 m³, but where hauling and transporting costs still are imminent due to the geographical position of the industry. The model is designed to decrease hauling distances along with lower fuel usage and ultimately effects on the environment.

     

    Increasing the volume of the timber yard is carried out by taking advantage of unutilized areas as well as by a compromise of areas that are today used for other processes.

     

    Lastly, the recommendations presented to the company are to analyze the results and research questions of the study and from there see to what actions are to be made. Developing the concepts of presented model along with the other suggestions and conclusions that follow.

  • 420.
    Wikner, Frida
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hur påverkas markberedningsresultatet vid harvning och högläggning av faktorer som lutning, ytstruktur och markfuktighet?2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Soil scarification means lot to the regeneration of the forest

    because a good soil scarification boost the increment of the plants

    and it also makes the plants less attractive to dangerous insects.

    The surveys purpose was to investigate how different site factors

    influence the soil scarifications results. The goal was to see if any

    scarification method was better adapted to a certain site then the

    other. In order to see a result the survey investigated the bearing

    capacity of the stands, the surface structure and the slope of the

    terrain.

    The surveys material has been collected during august - October

    2013 on SCA: s forest in Ångermanland in Sweden. Totally has

    65 harrowed sites and 35 scalped sites been visited and material

    collected from.

    The survey result shows that the scarification quality after

    scalping was higher than after harrowed sites. The number of 5: s

    and 4: s was more frequent after scalping but the number of

    mineral 3: s was higher after harrowing. The analysis of the

    results shows that scalping was more sensitive to the site slope

    and surface structure then harrowed sites, but when used on the

    the right ground it will provide a better quality result.

    The conclusion of the survey was that harrowing is the better

    choice of the scarification methods because it showed a more

    stable result then scalping that is more depending on the terrain

    conditions. Harrowing should not be used on moist ground due to

    the risk of Hylobius abietis attacking the plants. Scalping on the

    other hand showed a better result of the scarification quality and

    on the right ground it is the optimal choice.

  • 421.
    Windelberg, Jaanice
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Skogsskötsel för att främja sociala och estetiska värden i ett friluftsområde i Trollhättans Stad2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Over 80% of Sweden's population lives in urban areas, and half of the country's forest visits will thus be in urban woodlands. Social values ​​- how the individual experiences the forest, and the impact of the forest visits on individual health and well-being, are pointing to the importance of managing the urban woodlands.

    When there comes to the cultivation of the urban woodlands there are usually many opinions to consider.

    This study aims to investigate the various opinions on the use and forestry in an urban recreation area in ​​the City of Trollhättan. The study addresses both general and in four cases specific suggestions on management methods.

    Data was obtained from both quantitative and qualitative study through survey, interviews and discussions with the users of the recreation area.

    Trollhättan's goal with the recreation area is to make it accessible to local residents. The users are mainly influenced by the accessibility therefore clearings and thinnings are appreciated. Clear cuts should be avoided, but can be used as a method if logging residues are removed afterward.

    Variation is important for the specific areas, the focus is laid on hardwood species. Where hardwood is missing the focus should be to create old and sparse forest. 

  • 422.
    Ågren, Risto
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Tillväxtreaktioner i Naturkultur -utvärdering av en försöksyta i Östergötland2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Studien är en utvärdering av provytor i Östergötland anlagda i SLU:s regi enligt Naturkulturmetoden. Hypotesen med Naturkultur är att metoden ger bättre resultat avseende ekonomi, naturvård och mångbruk på samtliga ståndorter i Sverige.

    Syftet med studien var att mäta tillväxtreaktioner hos kvarlämnade dominanter och grova träd, undersöka hur grundytan fördelar sig i olika diameterklasser samt i vilka diameterklasser volymproduktionen hamnar.

    Undersökningen genomfördes som en fallstudie med kvantitav ansats, där underlaget bestod av två tidigare inventeringar samt en ny inventering 23 tillväxtsäsonger efter försöksetablering.

    Majoriteten av ytorna hade en relativ tillväxt som var lika hög eller högre hos dominanter och grova träd än kontrollparcellen. De hårdast gallrade parcellerna hade högst inväxning. Resultatet pekar på att för hårda gallringar vid enstaka tillfällen sjunker tillväxten på lång sikt. Nytt bestånd kan konkurrera kraftigt med de kvarlämnade dominanterna och grova träd.

    Slutsatsen är att denna rapport inte kan användas som underlag för rekommendationer för hur skötsel enligt Naturkultur ska bedrivas, men den kan ge vägledning till att hitta vägar i skogsskötseln där ekonomi, miljö och rekreation tillsammans kan få ett större värde än dagens trakthyggesbruk.

     

  • 423.
    Åhman, Mikael
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Laserdata i skogsbruket: - och möjliga tillämpningar för privata skogsägare2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Data retrieved from airborne laser scanning represents a new source of forest data. Today, the technology has matured so that it can function in an operational environment. The aim of this study was to compile areas of application of laserdata in forestry. Moreover to analyze costs and accessibility of laserdata. The goal was to provide private forest owners information to support assessments of possible benefits of laserdata. Data produced by Skogsstyrelsen and SLU seems to be useful for private forest owners. These data i.e. includes maps of digital terrain models, tree heights, stand volumes, tree diameters, basal areas and biomass. Today, the costs for airborne laser scanning are high for the private forest owners. Perhaps co- ordinations between forest owner organizations and other timber buying companies could solve this problem. 

  • 424.
    Åsa, Andersson
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. 9203045621.
    Förröjningsstrategier vid förstagallring.: En jämförelseanalys mellan två olika förröjningsmetoder.2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The need for brushing before the first thinning has increased during the last few years. This brushing involves taking away small trees and bushes making it able for the harvester operator to see better and choose the correct trees to be harvested. In today’s silviculture the brushing is often neglected which means that the undergrowth becomes dense and leads to less efficiency for harvesters and a rise in costs. A well brushed first thinning will make the harvesting costs low and time efficient.

     

    In brushing before the 1st thinning all stems below 9 cm d bh are traditionally taken down. This has a tendency to become stereotyped; i.e. brushes are also taken away in areas where  stronger nature conservation should be applied, as in wetlands, edge zones, etc. The harvester operator then gets stuck in these zones which threaten the biodiversity. 

     

    This study aims at examining two different types of brushing methods before the thinning, the traditional one and another (new) method where environmental and nature protection aspects were taken into account to a greater degree; i.e. where more stems and undergrowth have been left over and edge zones were not brushed. The study results show that the latter one is to prefer as the more cost efficient one. It also protects the harvester to drive out into the edge zones. This method is also beneficial for the wildlife.

     

    Most harvester operators were positive to a new brushing manual. 

  • 425.
    Öberg, Daniel
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    En jämförande studie mellan stickvägsgående och beståndsgående skördare och skotare.2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Thinning is performed today with essentially two thinning methods, with strip-roads or stand-thinning machines. The result after thinning affects the stands future development.

    In this study, the two thinning methods was compared with regard to distribution of basal area, resulting damage, the distribution of stems, actual thinning intensity and the impact that these differences may provide in the future.

    The survey was conducted in Sundsvall, Sweden in two different stands where basal area- surfaces, number of stems, damage and thinning strength was measured.

    The result shows that stand-thinning machines produce less damage to the stems and a more even distribution of the basal area. The strip-road method carried out a thinning of excessive thinning intensity of 50 % compared to 30 % for stand-thinning method.

    From a quality point of view the stand-thinning machines performed a better result. These machines have a lower production (harvested volume per hour) which probably results in lower financial gains in thinnings.

    Keywords: stand-thinning, basal area, thinning strength, Vimek, soil damage.

  • 426.
    Ökshei, Jorunn
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Eriksson, Hannah
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Certifieringens betydelse för naturvärden i skogen2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    En viktig målsättning i den svenska skogspolitiken är att skogsbruket ska bedrivas på ett hållbart sätt och i Skogsvårdslagen är produktionsmålen och miljömålen jämställda. Skogsägare kan utöver detta åta sig att certifiera sin fastighet, antingen genom FSC eller PEFC. Certifiering är ett marknadsdrivet, frivilligt åtagande och handlar om att ta ett större ansvar för miljö och natur än vad Skogsvårdslagen kräver.  Syftet med denna studie är att jämföra förekomst av naturvärden på certifierade fastigheter och icke-certifierade fastigheter genom fältinventering av utvalda kriterier. Kriterierna valdes utifrån mätbara och synliga indikatorer på naturvärden och utifrån faktorer som speglar variationsrikedom, hänsyn, kontinuitet, flora-och faunaobjekt och återväxt. I denna studie har vi arbetat fram en funktionell inventeringsmall i syfte att kartlägga naturvärden på fastighetsnivå.  En slutsats från inventeringen var att naturens egna förutsättningar är en viktig faktor för förekomsten av naturvärden i högre grad än om fastigheten är certifierad eller inte.

6789 401 - 426 of 426
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf