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  • 1.
    Aaby, Susanne
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. 1991.
    Carlsson, Henric
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Effektivisering av timmerplan på Kinnaredsågen2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sågverken i Sverige letar kontinuerligt efter lösningar för att kunna effektivisera produktionen. I denna studie analyseras specifikt Derome Kinnareds sågens timmerplan. Genom en stopptidsanalys, undersökningar av nya tekniska lösningar, muntliga kommunikationer med personal samt arbetsledare och andra företag införskaffades underlag till analys. Åtgärder som kan utföras för att minimera produktionskostnaderna eller öka produktionen på timmerplan är att implementera ny teknik t.ex. fjärrmätning, digitalisera mätbesked med hjälp av SDC:s arkiv, omorganisera personalstyrkan samt införskaffa bemyndigad mätare. Förslagen indikerar att implementering av dem kan förbättra Kinnaredsågens ekonomi. Beroende på hur mycket företaget är villigt att investera kan det effektiviseras i olika grad. I samband med kommunikation med företagsrepresentanter kom man dock fram till att ny teknik kan vara bättre att implementera vid en nybyggnation.

  • 2.
    Abrahamsson, Håkan
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Skogstillståndet på ön Blå Jungfrun2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of the study was to investigate the forest in the national park on the Blue Maiden Island and compare with mainland forest data. The study was made in a quantitative way. The results from the field measurement were related to data from the Swedish National Forest Inventory.

    Oak, Scots pine and Lime were the most common tree species and constituted 47, 18 and 16 % of basal area, respectively, on the island.

    The mean heigt was 7 m and the volume of living trees was on average 72 m³/ha and dead wood 30 m³/ha. The average age at breast height was 137 years and the oldest tree was an oak with the age of 335 years at breast height. The amount of dead wood constituted 40 % of the total volume. Disturbances have had influence on the forest on the Island. To what extent cannot be determined without further investigations.

  • 3.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    A laser drilling technique to improve impregnability of spruce and fir2016In: 3rd BASF Wolman Conference, 14 September 2016, Linnaeus University, Växjö, Sweden, 2016Conference paper (Other (popular science, discussion, etc.))
  • 4.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Group of Forest Products2018In: Presented at Symposium "Perspectives in Renewables", 4-5 June 2018, BOKU Vienna, Austria, 2018Conference paper (Other academic)
  • 5.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Morphology, properties and recyclability of modified fibres and papers with different chemicals at laboratory, pilot plant and industrial trials2015Conference paper (Other (popular science, discussion, etc.))
  • 6.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Utilisation of renewable biomass and waste materials in furniture and construction composites2018Conference paper (Other academic)
  • 7.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Wood variation and properties for industrial use2018In: Presented at FRAS workshop “Varierat skogsbruk  - hur påverkar olika skötselstrategier framtidens träprodukter?", 2018Conference paper (Other (popular science, discussion, etc.))
  • 8.
    Adamopoulos, Stergios
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Ahmed, Sheikh Ali
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Lankveld, Chiel
    Accsys Group.
    Acoustic properties of acetylated wood under different humid conditions and its relevance for musical instruments2018In: Proceedings of the 9th European Conference on Wood Modification 2018, Arnhem, The Netherlands / [ed] Jos Creemers, Thomas Houben, Bôke Tjeerdsma, Holger Militz and Brigitte Junge, The Netherlands: Practicum , 2018, p. 236-243Conference paper (Refereed)
    Abstract [en]

    In musical instrument making, less expensive wood species and materials with good characteristics and acoustical properties can provide potentials to find alternatives to the traditional exotic wood species used today. Modified wood could be such a choice if shows similar sound characteristics to wood coming from endangered and expensive tropical species with problematic commercial availability. In musical instruments, the overall functionality depends on the contribution of wood to different material performance indexes like sound radiation coefficient (R), characteristic impedance (z) and acoustic conversion efficiency (ACE). In this study, the performance indexes were measured for acetylated beech, maple and radiata pine and compared with these obtained for the reference wood materials maple, mahogany, alder and ash. A non-destructive free-free flexural vibration test method was used at constant temperature (20oC) but in different humid conditions- dry (35% RH), standard (65% RH) and wet (85% RH). Dimensional changes in the different humid conditions were also taken in account. Acetylated wood showed lower EMC with higher dimensional stability at each humidity level as compared with the reference wood materials. These properties are considered important factors for making quality musical instruments. Based on the acoustical properties, acetylated wood materials, especially radiata pine, showed good potential for use for musical instruments where specific characteristics of sound are required. However, the other types of acetylated wood can also be used for specific musical instruments.

  • 9.
    Adamopoulos, Stergios
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Birmpilis, D
    Technological Educational Institute of Thessaly.
    Use and properties of recovered paper raw materials for the production of corrugated board2015In: Proceedings of the 14th International Conference on Environmental Science and Technology Rhodes, Greece, 3-5 September 2015, Global NEST , 2015Conference paper (Refereed)
    Abstract [en]

    The difficulty of predicting the properties of paper products produced from heterogeneous sources puts several limitations, which therefore lead to severe economic losses and only a comprehensive characterization will enable their better utilization. The project “RF-CORRUG –Quality control of raw materials from recovered fibres for the production of corrugated board”under the NationalStrategic Reference Framework 2007–2013 ARCHIMEDES IIIdeals with this common technical problem of the corrugated board industry. Specifically, the mainobjective of the project is to supportthe competitiveness of the corrugated board companies (mainly SMEs)by creatinga software tool based on practical models that can predict packaging grade paper properties from fibre data (qualitative, quantitative, morphological) used in their production. This paper presents information on the physical and mechanical properties of recovered packaging papers used in corrugated packaging. A number of different category papers (liners, flutings) used for corrugated board production in Greece were examined. The required paper properties included grammage, porosity, bursting strength, SCT, tensile strength and tearing resistance, and were measured by internationally recognized testersand standards. The data will be used to develop predictive models based on advanced statistical methods for the properties and performance of packagingaccording to information of their recovered raw paper materials.

  • 10.
    Adamopoulos, Stergios
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Foti, Dafni
    Aristotle University of Thessaloniki, Greece.
    Voulgaridis, Elias
    Aristotle University of Thessaloniki, Greece.
    Passialis, Costas
    Aristotle University of Thessaloniki, Greece.
    Manufacturing and properties of gypsum-based products with recovered wood and rubber materials2015In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 10, no 3, p. 5573-5585Article in journal (Refereed)
    Abstract [en]

    The experimental production of gypsum-based products (cylindrical samples, solid bricks) using different fractions of wood chips and rubber particles was studied. Recovered rubber and wood materials were mixed with gypsum and water in various proportions to fabricate gypsum-wood and gypsum-rubber cylindrical samples and standard solid bricks with six holes using appropriate molds. It was shown that to manufacture gypsum-wood and gypsum-rubber products with good mechanical strength, coarse fractions of wood and rubber should be used, but the proportion of wood or rubber should not exceed 25%. No thermal conductivity differences were found between the wood-and rubber-type of gypsum products, and particle size and material proportion had no effect. Samples with fine wood and rubber particles present at a lower proportion (25%) exhibited similar sound absorption behavior. The solid bricks had slightly higher strength when loaded at the large surface of their lateral upper side than when loaded at the small surface. The bricks provided better thermal insulation than both the extruded and pressed house bricks but lower than that of insulating bricks. The emission of volatile organic compounds out of the bricks was at an acceptable level according to regulations for construction products.

  • 11.
    Adamopoulos, Stergios
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Karageorgos, Anthony
    Technological Educational Institute of Thessaly, Greece.
    Rapti, Elli
    Center for Research and Technology – Hellas (CERTH), Greece .
    Birbilis, Dimitris
    Technological Educational Institute of Thessaly, Greece.
    Predicting the Properties of Corrugated Base Papers Using Multiple Linear Regression and  Artificial Neural Networks2016In: Drewno, ISSN 1644-3985, Vol. 59, no 198, p. 61-72Article in journal (Refereed)
    Abstract [en]

    The difficulty in predicting the properties and behaviour of paper products produced using heterogeneous raw materials with high percentages of recovered fibres poses restrictions on their efficient and effective use as corrugated packaging materials. This work presents predictive models for the mechanical properties of corrugated base papers (liner and fluting-medium) from fibre and physical property data using multiple linear regression and artificial neural networks. The most significant results were obtained for the prediction of the tensile strength of liners in the cross direction from the origin (wood type, pulp method) of the fibres using linear regression, and the prediction of the compressive strength of fluting-medium in the longitudinal (machine) direction, according to the short-span test, using a neural network with one hidden layer with 6 neurons, with coefficients of determination at 95.14% and 99.28%, respectively

  • 12.
    Adamopoulos, Stergios
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Karastergiou, Sotirios
    Technological Educational Institute of Thessaly, Greece.
    Foti, Dafni
    Aristotle University, Greece.
    Filippou, Vasileios
    Aristotle University, Greece.
    ΑΝΑΚΤΗΣΗ ΞΥΛΟΤΕΜΑΧΙΔΙΩΝ ΑΠΟ ΑΠΟΣΥΡΟΜΕΝΕΣ ΜΟΡΙΟΠΛΑΚΕΣ ΜΕ ΥΔΡΟ-ΜΗΧΑΝΙΚΕΣ ΜΕΘΟΔΟΥΣ: [ Chips recovered from waste particleboards by hydro-mechanical methods ]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. 349-356Conference paper (Refereed)
    Abstract [en]

    It was studied the recovery of wood chips from waste particleboards by immersion in water at ambient temperature and by mechanical treatment (agitation and impact, waterblasting). Four different categories of waste particleboards were used, with and without coating, after their reduction in smaller pieces with dimensions of about 7 × 8 cm.  The investigated methods were: (I) immersion for 3 days-impregnation with vacuum and pressure-agitation and impact (II) immersion for 7 days-drying-rewetting for 12 hours-agitation and impact (III) immersion for 3 days-waterblasting. The maximum thickness swelling (about 90%) was achieved by immersing the particleboards in the water for 3 days, and therefore the vacuum and pressure impregnation step can be omitted in practice. Recovery of wood chips was significantly higher (51.54%) in the case of successive wetting and drying cycles compared to simple immersion in water (17.32%). Both these methods I and II, involving agitation and impact for recovering wood chips from waste particleboards, are easily applicable at the industry. Method III with waterblasting resulted in complete recovery of wood chips within a very short time, but its application requires more research

  • 13.
    Adamopoulos, Stergios
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Säll, Harald
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Sjöberg, Samuel
    Relationship between ultrasonic velocity and spiral grain in standing hybrid aspen trees2016In: Proceedings of the Hardwood Conference, Eco-efficient Resource Wood with Special Focus on Hardwoods, 8-9 September, 2016, Sopron, Sopron: University of West Hungary Press , 2016, p. 22-23Conference paper (Refereed)
  • 14.
    Ahmed, Sheikh Ali
    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.
    Acoustic properties of modified wood under different humid conditions and their relevance for musical instruments2018In: Applied Acoustics, ISSN 0003-682X, Vol. 140, p. 92-99Article in journal (Refereed)
    Abstract [en]

    In musical instrument making, there is a strong need to find alternatives to the traditional endangered and expensive tropical wood species used today. The present study examined whether different commercial and experimental modified wood materials have the necessary acoustic qualities under different humid conditions (dry, standard and wet) to contribute to the use of raw materials for wooden musical instruments. The materials were thermally-modified wood (ash, aspen and birch), acetylated wood (beech, maple and radiata pine), melamine- and phenol formaldehyde-treated beech and furfurylated Scots pine (Kebony Scots pine). Investigations involved physical (density ρ, Equilibrium moisture content EMC, volumetric shrinkage) and dynamic elastic testing by a free-free flexural vibration method to determine various acoustic characteristics: specific dynamic modulus (MOEdyn/ρ), damping coefficient (tanδ), speed of sound (c), specific acoustic impedance (z), sound radiation coefficient (R) and acoustic conversion efficiency (ACE). The modified materials and especially acetylated wood showed low EMC values and high dimensional stability at each humidity level, which are considered important factors for making quality musical instruments. Based on the obtained value ranges of all acoustical properties, the different modified wood materials could find uses in musical instruments where specific characteristics of sound are required. Furthermore, most of the modified materials showed an excellent acoustic performance in the three humid conditions based on a high ACE and low tanδ. Furfurylated Scots pine and phenol formaldehyde-treated beech showed an inferior acoustic quality with the lowest ACE and the highest tanδ, which is a less favourable combination for most of the musical instruments.

  • 15.
    Ahmed, Sheikh Ali
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Morén, Tom
    Luleå University of Technology.
    Sehlstedt-Persson, Margot
    Luleå University of Technology.
    Blom, Åsa
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Effect of oil impregnation on water repellency, dimensional stability and mold susceptibility of thermally-modified European aspen and downy birch wood2017In: Journal of Wood Science, ISSN 1435-0211, E-ISSN 1611-4663, Vol. 63, no 1, p. 74-82Article in journal (Refereed)
    Abstract [en]

    Conventional chemical wood preservatives have been banned or restricted in some applications due to human and animal toxicity and their adverse impact on the surrounding environment. New, low-environmental-impact wood treatments that still provide effective protection systems are needed to protect wood. Thermal modification of wood could reduce hygroscopicity, improve dimensional stability and enhance resistance to mold attack. The aim of this study was to investigate if these properties enhanced in thermally modified (TM) wood through treatments with oils. In this study, TM European aspen (Populus tremula) and downy birch (Betula pubescens) wood were impregnated with three different types of oil: water-miscible commercial Elit Träskydd (Beckers oil with propiconazole and 3-iodo-2-propynyl butylcarbamate, IPBC), a pine tar formulation and 100% tung oil. The properties of oil-impregnated wood investigated were water repellency, dimensional stability and mold susceptibility. The treated wood, especially with pine tar and tung oil, showed an increase in water repellency and dimensional stability. However, Beckers oil which contains biocides like propiconazole and IPBC showed better protection against mold compared with pine tar and tung oil. To enhance the dimensional stability of the wood, pine tar and tung oil can be used, but these oil treatments did not significantly improve mold resistance rather sometimes enhanced the mold growth, whereas a significant anti-mold effect was observed on Beckers oil treated samples.

  • 16.
    Alawode, Abiodun
    et al.
    Stellenbosch University, Department of Forest and Wood Science.
    Eselem-Bungu, Paul
    Stellenbosch University, Department of Forest and Wood Science.
    Amiandamhen, Stephen
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Stellenbosch University, Department of Forest and Wood Science .
    Meincken, Martina
    Stellenbosch University, Department of Forest and Wood Science.
    Tyhoda, Luvuyo
    Stellenbosch University, Department of Forest and Wood Science.
    Properties and characteristics of novel formaldehyde-free wood adhesives prepared from Irvingia gabonensis and Irvingia wombolu seed kernel extracts2019In: International Journal of Adhesion and Adhesives, ISSN 0143-7496, E-ISSN 1879-0127Article in journal (Refereed)
    Abstract [en]

    There is renewed interest in the domestication of Irvingia tree species due to the potential use of various parts of the tree as raw materials for a wide range of applications such as biodiesel production, cosmetics, perfumes, soap, weight-loss supplement etc. The current study investigates the properties of extracts from the seed kernels of two Irvingia species – Irvingia gabonensis (IG) and Irvingia wombolu (IW) as natural wood adhesives. Three extraction methods using various solvent/solute media were compared in terms of yield, composition and mechanical properties. Statistically, the analysis revealed significant differences between the different extraction methods. The adhesion properties of the extracts were tested on wood veneers according to the American Society for Testing and Materials standard (ASTM D – 906-64). The shear strength of the extracts ranged from 0.55 to 1.5 MPa and 0.86 to 1.7 MPa for IG and IW, respectively. The initial decomposition temperature of all Irvingia Kernel extract ranges from 138.3 – 149.11 oC for IG and 129.5 – 145.3 oC for IW. As a result, the hot melt temperature for the adhesive experiments was set around 150 oC. The results indicate that Irvingia kernel extract is a more promising source of non-formaldehyde based adhesives in wood composite production.

  • 17.
    Almeida, Juan Pablo
    et al.
    Lund University, Sweden.
    Rosenstock, Nicholas P.
    Lund University, Sweden.
    Forsmark, Benjamin
    Swedish University of Agricultural Sciences, Sweden.
    Bergh, Johan
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Wallander, Håkan
    Lund University, Sweden.
    Ectomycorrhizal community composition and function in a spruce forest transitioning between nitrogen and phosphorus limitation2019In: Fungal ecology, ISSN 1754-5048, E-ISSN 1878-0083, Vol. 40, p. 20-31Article in journal (Refereed)
    Abstract [en]

    Nitrogen is the main limiting nutrient in boreal ecosystems, but studies in southwest Sweden suggest that certain forests approach phosphorus (P) limitation driven by nitrogen (N) deposition. We added N, P or N + P to a Norway spruce forest in this region, to push the system to N or P limitation. Tree growth and needle nutrient concentrations indicated that the trees are P limited. EMF biomass was reduced only by N + P additions. Soil EMF communities responded more strongly to P than to N. Addition of apatite to ingrowth meshbags altered EMF community composition and enhanced the abundance of Imleria badia in the control and N plots, but not when P was added. The ecological significance of this species is discussed. Effects on tree growth, needle chemistry, and EMF communities indicate a dynamic interaction between EMF fungi and the nutrient status of trees and soils. (C) 2018 Elsevier Ltd and British Mycological Society. All rights reserved.

  • 18.
    Al-Najjar, Basim
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Jacobsson, Martin
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. LNU.
    A computerised model to enhance the cost-effectiveness of production and maintenance dynamic decisions: A case study at Fiat2013In: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 19, no 2, p. 114-127Article in journal (Refereed)
    Abstract [en]

    Purpose:

    – To develop and test a model and software-based support system for better understanding

    of the interactions between man-machine-maintenance-economy (MMME), and enable cost-effective decisions.

    Design/methodology/approach:

    – The study is based on published knowledge and experience within maintenance, maintenance organization and production, and a case study.

    Findings:

    – Development of a model describing interactions between man-machine-maintenance-economy interactions and MMME software module. MMME test shows its ability to identify, quantify, assess and follow up losses in production time which is necessary when planning effective maintenance actions.

    Research limitations/implications:

    – In the paper the focus is to quantify production time losses in order to identify the root causes of the problem. The case study is performed at a manufacturing plant for truck engines.

    Practical implications:

    – A systematic approach of how to quantify and evaluate losses in production time in order to identify problems and problem areas within the production. This approach is discussed and motivated with the aim of achieving more cost-effective decisions in maintenance.

    Originality/value:

    – The model and software application developed enables a structured way of analyzing production time losses in order to find cost-effective solutions to the problems. The model is very flexible enabling it to be customized for a wide spectrum of branches.

     

  • 19.
    Altgen, Michael
    et al.
    Aalto Univ, Finland.
    Willems, Wim
    FirmoLin Technol BV, Netherlands.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Rautkari, Lauri
    Aalto Univ, Finland.
    Hydroxyl accessibility and dimensional changes of Scots pine sapwood affected by alterations in the cell wall ultrastructure during heattreatment2018In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 152, p. 244-252Article in journal (Refereed)
    Abstract [en]

    There is a complex link between the water sorption behavior and the presence of accessible hydroxyl groups in the wood cell wall, which can be altered by heat-treatment (HT). This study analyses the effect of changes in the cell wall ultrastructure caused by two HT techniques on the hydroxyl accessibility, water vapor sorption and dimensional changes of Scots pine (Pinus sylvestris L.) sapwood. HT of wood in pressurized hot water at 120-170 °C was applied to cause the preferential bond cleavage, whereas HT of wood in oven-dry state in superheated steam at 180-240 °C was performed to create additional covalent cross-links within the cell wall matrix. Removal of cell wall polymers by HT and water leaching reduced the oven-dry dimensions of wood and enhanced the cellulose aggregation during drying. Cellulose aggregation restricted the cell wall shrinkage in circumferential direction, resulting in inhomogeneous shrinkage of the cell wall with only little changes in lumen volume by HT. Cellulose aggregation also reduced the water-saturated dimensions, but a decrease in swelling was only achieved when additional cross-links were formed by HT in dry state. Additional cross-links in the cell wall matrix also resulted in an additional reduction in water sorption at 25 °C and 93% RH. However, this was not caused by a further reduction in the hydroxyl accessibility. Instead, cross-linking was shown to reduce the amount of accessible OH groups that are simultaneously active in sorption, which was explained based on the concept of sorption of water dimers at hydroxyl group pairs at high RH levels.

  • 20.
    Alvskog, Kristina
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Rotstock av tall: Hur blir den framtida virkeskvaliteten?2014Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    In Sweden the quality of Scots pine (Pinus sylvestris) saw timber has decreased. It is especially due to increased labour cost that has led to rational and effective forest management.

    This study investigated the quality of Scots pine and the potential to produce high quality stems in 9 stands in Bergslagen, Sweden. Two different stand types were investigated: Pruned stands and conventional managed stands. The outcome was a high percentage of valuable stems in the pruned stands (72-94 %), and 46-56 % in the conventional managed stands. It is possible to produce high quality timber of Scots pine with active management, for example by pruning and careful selection of stems in thinnings.

  • 21.
    Amiandamhen, Stephen
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Stellenbosch University, Department of Forest and Wood Science .
    Meincken, Martina
    Stellenbosch University, Department of Forest and Wood Science.
    Tyhoda, Luvuyo
    Stellenbosch University, Department of Forest and Wood Science.
    Phosphate bonded natural fibre composites: a state of the art assessment2019In: Applied Sciences, ISSN 2523-3963, no 1Article, review/survey (Refereed)
    Abstract [en]

    Over the last few decades, innovative wood composite products and processes have created markets for new and existing products. Inorganic bonded fibre composites have been developed for high performance applications using conventional cement and concrete. The demands for wood based composites along with increasing economic and environmental concerns on conventional wood products necessitate moving beyond the traditional processing methods to more cost-effective and environmentally friendly approaches. In the wake of the twenty-first century, a fast-setting phosphate binder with a low carbon footprint was developed, which can alternatively be utilized in wood composite development. This paper reviews the recent progress in phosphate bonded composite products, based on published literature from the last two decades. A brief background on Portland cement based natural fibre composites is presented. In addition, the mechanism of the formulation of phosphate binders, the effect of aggregates in the materials and the environmental benefits accruable to such materials are discussed.

  • 22.
    Andersson, Anton
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Davidsson, Adrian
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hur mycket står risskotare stilla på grund av kommunikationsproblem?2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The communicative interaction between contractor and subcontractor of residue forwarder plays a crucial role in the efficiency of handling forest residue. Since that type of work is at the end of the harvesting process, it may be that it is not as prioritized as the previous harvesting measures. The study investigates the communicative interaction between subcontractor that drives a residue forwarder and contractor and its connection to work-related production stops. The study was accomplished by a web-based survey and quantitative interviews conducted with eight selectively selected residue forwarder drivers in southern Sweden. The result of the survey showed that the average of all total production stops was one hour and 52 minutes under an average stop period of 25 working days. Most of the stops were caused by other work-related problems. Communication problems accounted for 20% of the number of production stops and the average stop duration was one hour and five minutes. The time when a residue forwarder was inactive seventeen minutes per day. In conclusion, the communicative problems are not the main reason to inactivity for residue forwarders. However, communication plays an important role in productive harvesting and represent the biggest possibility for improvement in the communication between residue forwarder drivers and contractor, which could lead to fewer production stops.  

     

    Residue Forwarders, Communication Problems, Production Stop and Forest residue. 

  • 23.
    Andersson, Björn
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Utvärdering och utveckling av Fiskarhedens Trävaru AB:s traktdirektiv för slutavverkning2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Gross felling has accelerated in recent decades, and as a consequence, the requirements for forestry have increased. Today a comprehensive environmental consideration needs to be taken. This also imposes higher demands on the contractors. In order for contractors to be able to live up to the requirements, it is important that the customer of the service hands over a work instruction in connection to the removal of region assignments. This work instruction and work order is created in the form of a region directive. A qualitative region directive is considered important for Fiskarhedens Trävaru AB and for their contractors. A case study has been conducted to evaluate and describe the company's current region directive. The results show that the current region directive is sometimes inadequate due to that they are poorly completed. Important content is therefore not communicated as needed. A proposal of a new improved region directive, where the content is intended to be filled in better, has therefore been developed. With the help of this region directive, Fiskarheden can maintain sustainable forestry.

  • 24.
    Andersson, Erik
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Noggrannhet och precision vid beståndsuppskattning av mobilapplikationen KATAM2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this essay was to evaluate the mobile application KATAM of accuracy, time, precision and practical use in comparison to volume estimation with data Digital Caliper and harvester report. The result of the diameter comparison showed similar estimates from KATAM and the Digital Caliper respectively. KATAM had a higher mean basel area, 7% and coarser mean diameter, 3.7%, compared to the Digital Caliper. KATAM also had overestimations in volume as compared to the harvesting report and the Digital Caliper concerning the mean stem, from 2.5% to 17.6%, depending on which sample areas were included and which version of KATAM was used. However, the basis of volume estimates was small and had error sources, which made the results of the measurements uncertain. Although the study shows an overestimation of the diameter, the mutual precision indicates that KATAM could be an alternative to the Digital Caliper when estimating the mean diameter.

  • 25.
    Andersson, Haidi
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. 1965.
    Hur upplevs estetik i skogsbruket?: How is aesthetics in forestry perceived?2016Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
  • 26.
    Andersson, Helena W.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Skogsnäringens kompetensförsörjning: - en studie av hur nyutexaminerade studenters kompetens matchar näringens förväntningar2018Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Skogsnäringens kompetensförsörjning har beskrivits som en kritisk fråga för näringens fortsatta utveckling. Den skogliga utbildningens kvalitet, konkurrensförmåga och relevans för arbetsmarknadens krav är viktiga faktorer i rekryteringen av kompetenta personer till näringen. Det finns även ett uttalat behov av att öka attraktiviteten i såväl de skogliga utbildningarna som i de skogliga jobben. Detta examensarbete syftade till att studera matchningen mellan de nyutexaminerades kompetens och skogsnäringens förväntningar. En kvalitativ metod valdes för studien och semistrukturerade intervjuer genomfördes med nyanställda och med representanter från skogsnäringen. Resultatet pekar på förbättringsmöjligheter hos de skogliga utbildningarna med mer nischade utbildningsalternativ och praktiska tillämpningar som integreras i utbildningen, men också en tydligare definition av de olika yrkesrollerna inom skogsnäringen. Studien visar på ett behov av dialog och samverkan mellan akademi och skogsnäring. Men framför allt en gemensam syn hos medarbetare och ledning på vilken kompetens som krävs.

  • 27.
    Andersson, Helena W.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Utvärdering av metoder för att mäta mental arbetsbelastning hos skotarförare - vid delautomatiserat och konventionellt kranarbete i simulatormiljö2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Forward operators are subjected to both physical and mental workload in their work and a way to reduce mental workload and increase productivity is to automating the crane movement. To enable study the impact of automation you need methods to estimate the forwarder operators mental workload in conventional crane work and with semi automation. This study evaluated the psychophysiological parameters; trapezius muscle activity, heart rate, heart rate variability, respiratory rate, skin conductance and finger temperature. To ensure the validity and methodology reliability one need to perform more extensive studies. As for future studies this work propose additional studies of forward operator mental workload in the simulator environment regarding heart rate, heart rate variability and respiration.

  • 28.
    Andersson, Helena W.
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Rickardson, Anders
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Timmerkvalitet hos björk i blandskog med gran2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Birch is the dominant deciduous tree species in Sweden but only 16 % is found in pure birch stands. The majority of the birch (51 %) is to be found in conifer dominated stands. Swedish forest land comprises approximately of 23 % mixed stands and one problem is that for mixed stands there are few management recommendations. The underlying aim of this thesis was to study the management of mixed forest stands of spruce and birch to achieve good timber quality of birch. The study was based on a literature study and measurement in a field experiment launched in 1998 by the Swedish University of Agricultural Sciences (SLU). This study indicates that it is possible to achieve good timber quality of birch in mixed stands of birch and spruce. However, it requires that birch in mixed stands with spruce should be managed similar to management programs of pure birch stands.

     

    Keywords: Birch, spruce, timber quality, mixed stands.

     

  • 29.
    Andersson, Ida
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Distansskogsägares nöjdhet med Södras tjänsteutbud och kvalité på tjänster2015Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    The development of technology and the mechanization in the Swedish forestry has during the last 60 years resulted in depopulation of the country side and due to that the amount of distance forest owners has increased. Therefore the forest companies need to make some adjustments in order to keep the distance forest owners as customers and to attract new ones. The purpose of this essay was to examine and analyze the distance forest owners satisfaction with Södras service offering and quality of service and further develop some proposals for action. A web-based survey was sent out to 634 distance forests owners in Stockholm, Sweden, all members of Södra. 269 respondents participated in the survey and of them, 27 did also participate in a follow-up telephone interview. The results show that the members generally was satisfied with the service offering and the quality of service. Suggestions for improvement regarding the service offering is all about implementing forest management courses in Stockholm and including providing financial and generational counseling, also on location in Stockholm. The quality of service can be improved if the inspector changes the way of working towards an even more customer adapted way and also improve the dialogue with the entrepreneurs. Further suggestions for improvement is to a greater extent welcome complaints and to give some compensation and/or apologize when it is motivated.

  • 30.
    Andersson, Jonas
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Föryngring med tallsådd- ett underskattat alternativ?2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this study was to investigate the attitudes of forest owners to direct sowing of pine (Pinus sylvestris L.) and also why so few have used the method. The study also aimed to identify reasons for forest owners to use or not to use the method. A questionnaire was sent to 240 non-industrial private forest owners (NIPFs) all over Sweden. As a complement, interviews were performed with forest companies from the north and middle parts of Sweden. The results showed that 15 % of the NIPFs respond that they had used the method direct sowing of pine at some occasion in the past. No forest owner origination from Götaland had used the method though. It was more common among those who owned a forest property of 100 hectares or more than among those who owned 49 hectares or less. Most of those who had used direct sowing in the past were satisfied with the outcome of the regeneration, 92 %, and 73 % were willing to use the method again. They also showed a more positive attitude to direct sowing, 86 %, compared to those who had not tried the method, where 23 % were positive and 69 % were neither positive nor negative. The main reason for not have used the method showed to be that the NIPFs answering this questionnaire had not thought about it. Of the companies interviewed in this study, Sveaskog and Holmen were the ones that have used direct sowing the most: Sveaskog sow 27 % of the yearly pine regeneration area and Holmen just over 20 % of the yearly pine regeneration area, including lodge pole pine (Pinus contorta Douglas ex Loudon). The main reason to why the companies have used direct sowing was that they consider the method cost effective. The also appreciate that the method results in a lot of stems per hectare which has been positive in areas where browsing is a problem. The results from the questionnaire showed that those had sown pine in the past tended to have a more positive attitude to the method than the forest owner that had not sown. This indicates that they have had a positive experience of the method. Nearly half of those who had not sown had neither a positive nor a negative attitude to it. One possible reason for it is that they had no experience of the method and therefore no opinion. Direct sowing works well to combine with other methods and can be adapted to different conditions. In a time when damage from browsing can cause big problems to regenerations of pine, sowing could be an important tool in the toolbox.

  • 31.
    Andersson, Matilda
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Naturkultur för bättre kvalitet i rotstocken i tallungskog?: Utvärdering av röjningsförsök i Kråkerödjan2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Scots pine (Pinus sylvestris L.) form a large part of Swedish forestry and has many alternative end-use areas with different requirements for quality. The ability to influence the quality is high in the initial planting and juvenile forest phase, as studies have shown relationships between good quality and dense planting, where competition between trees has a good impact on timber quality. Competition can also be achieved by shading from above, through seed trees or multi-layered forest. Interest in continuous cover forestry grows, and investigating differences in future timber quality between layered and clear cutting treatments can therefore be valuable. Such a method is “Naturkultur”, which aims to optimize the net present value at every point in the forest. The purpose of this study is to highlight the question of whether layered forests methods similar to “Naturkultur” can be used for higher timber quality in pine forests in a cleaning trial in southern Östergötland, Sweden. The goal is to find out if any difference in timber quality exists in the future butt log between the different cleaning treatments, layered (Uneven) and conventional (Even). The survey was limited to studying only the Kråkerödjan pre-commercial thinning trial, located on the property Kråkerödjan between Småland and Östergötland. Parameters for quality estimation were delimited to knot quantity and knot thickness. In order to answer the purpose, a field survey was conducted with quantitative assumptions where data about stem quantity, tree species distribution, height, diameter, height of the living crown, number of knots and diameter for the thickest knot from the base of the trunk up to 2 m on the trunk were collected. The result showed that the number of stems per ha was significantly higher in Uneven than in Even while the volume was next to the same. The average diameter was about 4 cm in Uneven and about 10 cm in Even. The tree species distribution was the same for trees with a diameter > 5 cm a breast height (bh) in both parcels,> 95% pine. For trees <5 cm bh, the distribution in Uneven was 14 % pine, 10 % spruce and 76 % deciduous, in Even there were almost exclusively deciduous trees. When examining pine > 5 cm at bh, there was a significant difference in the knot quantity with fewer knots/m in Uneven than in Even. The thickest knot was smaller in Uneven than in Even, but the difference was only significant when the data without dominants was examined. The thickest knot was slightly smaller relative to the diameter of the trunk in bh in Uneven but the difference was not significant. The average diameter in pine > 5 cm at bh was slightly less in Uneven, 10.7 cm, than in Even, 10.8 cm. The survey gives an indication that the layered forest according to the method of “Naturkultur” in the parcel Uneven, where dominants shades smaller trees, may be used for a better timber quality in pine in the investigated premises. However, the results are not sufficiently clear, if this is due to the fact that the quality difference is small or if it is because quality differences have not yet occurred V cannot be read in the survey. Estimating timber quality early in the rotation period is difficult as a lot can happen until final felling. However, the survey has been valuable as more data is needed in the area in question. Follow-up of the survey is needed to further explore the relationships between stock treatments and quality development.

  • 32.
    Andertun, Rickard
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Aptering för högre medellängder på massavedssortimenten2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    För att transporterna skall bli mer ekonomiska och samtidigt ha en liten miljöpåverkan krävs det att maximera transporterna viktmässigt och minimera avstånden. Ett tillvägagångssätt för att utnyttja lastkapaciteten är att ha en hög medellängd på virket för att transportera mindre luft i den begränsade volymen på lastbilen. Den här studien undersöker medellängder på massaved hos Sydved. Sydved har ett miljömål där 90% av volymen skall hålla minst 4,2 m medellängd på barr, gran och lövmassaved. En ökad medellängd på massaveden får inte påverka timmerutbytet eftersom det primära skall vara att aptera för bästa ekonomi för markägaren. Studien undersöker om och hur aptering för en ökad medellängd på massaved av gran påverkar timmerutbytet. Studien resulterar i att aptera massaveden till högre medellängder för att nå miljömålet kan påverka timmerutbytet både positivt och negativt.

  • 33.
    Avdan, Tayfun
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Circular Product Design: Developing (dis/re)assembly oriented methodology towards product end-of-life2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis aims at developing a (dis/re)assembly oriented methodology towards product end-of-life. Particular focus in this thesis is on the circularity of furniture via design for (dis/re)assembly. The main motivation behind this study was the need for a method to evaluate the (dis/re)assembly options of furniture designs to be able to facilitate repair, reuse, remanufacturing, refurbishing, or recycling.

    The study draws upon relevant theories and prior research on Circular product Design, Design for EoL, Design for Environment, and Design for (Dis)assembly of vehicles, electrical and elocronic equipments, whitegoods, as well as office furniture, though relatively limited.

    The proposed methodology determines major aspects of design for (dis/re)assembly to be taken in to consideration in the early stages of product development. It further provides a set of parameters that are relevant to cabinet type and upholstery furniture group.

    The study involves a variety of qualitative research methods that are embedded in an interactive research conduct with the engagement of different stakeholders that are charged with the task of product development at Ikea of Sweden (IoS), the collaborator of this study. 

    The proposed methodology is implemented on three selected furniture designs in a pilot study. The results of the study, above all, suggest that (dis/re)assemblability of a product is a strategic choice that needs to be made at early phases of product development, namely the design phase. Two particular features of the furniture groups, upon which this study focuses, emerges as factors having negative impact on the disassemblability of products: first, wooden frame sofas with respect to their complex structure and connectivity of componants and, second, permanent joints with respect to their destructive impact on the product.

    The study concludes that it is feasible to develop and implement a potentially comprehensible method to evaluate the ease of disassembly of furniture products and to design for disassembly. The proposed methodology in this study is a contribution to support product design for disassembly towards product circularity.

  • 34.
    Axelsson, Magnus
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Emissioner av växthusgaservid gödsling av granungskog isödra Sverige2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    BAG leads to a greater forest growth, which could have a positive influence on thecarbon balance. To increase our understanding of the effect fertilization have ongreenhouse gas emissions, this study have examined the respiration of a juvenilespruce forest on the estate of Toftaholm (57°0'N; 14°3'E), where the soil-texturewas manly sand-moraine with a medium humidity, with main focus on theemissions of methane and nitrous gas. The results indicated a small increase innitrous gas and a continued net binding of methane independent of amount offertilization. The small increase in greenhouse-gas indicates a continuation withincreased amount of fertilization. For operational productivity with an amount offertilization (150khN/Ha and year) no significance could be determent.

  • 35.
    Bahr, Adam
    et al.
    Lund University, Sweden.
    Ellström, Magnus
    Lund University, Sweden.
    Bergh, Johan
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Wallander, Håkan
    Lund University, Sweden.
    Nitrogen leaching and ectomycorrhizal nitrogen retention capacity in a Norway spruce forest fertilized with nitrogen and phosphorus2015In: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 390, no 1-2, p. 323-335Article in journal (Refereed)
    Abstract [en]

    Aims

    To estimate the production of external ectomycorrhizal mycelia (EMM) in Norway spruce forests with varying nitrogen (N) and phosphorus (P) levels, and to relate this to the N retention capacity of ectomycorrhizal fungi (EMF) and N leaching.

    Methods

    Seasonal changes in EMF production (in ingrowth mesh bags) and soil water N (in suction lysimeters) were analyzed after fertilization with N or N combined with P. The EMF N retention capacity was estimated by the addition of isotopically labeled N to the mesh bags.

    Results

    No relationship was found between the seasonal variation in EMF growth and N leakage from the soil. However, in the mesh bags, the total assimilation of 15N by EMF was almost halved by N fertilization, while twice as much 15N leached through.

    Conclusions

    We found a high specific N assimilation capacity per unit weight of EMF mycelia. This was unaffected by N fertilization, but the total assimilation of N by EMF was drastically reduced due to reduced production of EMM. However, N-retaining processes other than N assimilation by EMF must be taken into account to explain the losses of N after fertilization.

  • 36. Balea, A
    et al.
    Blanco, A
    Fuente, H
    Concepción, M
    Negro, C
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hosseinpourpia, Reza
    Mai, C
    Tubek-Lindblom, A
    Hansen, P
    Morphology, properties and recyclability of modified fibres and papers with different chemicals at laboratory and pilot plant trials2015In: 46th Congresso Annuale Aticelca, May 28-29, Sestri Levante-Genova, Italy, Aticelca , 2015, p. 23-31Conference paper (Refereed)
    Abstract [en]

    Fibre+ (2012-2015) is a European project aiming to develop potential treatments for recovered fibre modification capable of improving the recyclability and the properties of recycled papers. This study reports on the results on fibre morphology, paper properties and recyclability of fibres and papers modified with different chemicals and approaches from both laboratory and pilot plant trials. Sixteen modification chemical agents were studied in a set of laboratory trials. The raw material used was 100% recycled paper grade from old corrugated board containers (OCC). The laboratory analysis to evaluate the effectiveness of fibre modifications treatments included FBRM for pre-screening of chemicals, preparation of laboratory control and modified handsheets to a target grammage of 80 g/m2, and measurement of the fibre morphology, recyclability and mechanical and physical properties of the modified handsheets. Based on the results of laboratory testing, Fibre+ modifications pilot plant trials were carried out at a FEX paper machine. Furthermore the effect of the better dispersion of the cPAM using an ECOWIRL was studied. The overall laboratory and pilot plant results were promising for further implementation of the Fibre+ modifications at industrial scale and projection of improvements of fibre and paper properties on the performance of packaging products thereof

  • 37. Bastani, A
    et al.
    Militz, H
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Effect of wood modification on water related properties and penetration of adhesives into Scots pine and beech2015In: Eighth European Conference on Wood Modification, October 26-27, Helsinki, Finland, Aalto University , 2015, p. 367-371Conference paper (Refereed)
  • 38.
    Bastani, Alireza
    et al.
    Georg-August-University Göttingen, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Koddenberg, Tim
    Georg-August-University Göttingen, Germany.
    Militz, Holger
    Georg-August-University Göttingen, Germany.
    Study of adhesive bondlines in modified wood with fluorescence microscopy and X-ray micro-computed tomography2016In: International Journal of Adhesion and Adhesives, ISSN 0143-7496, E-ISSN 1879-0127, Vol. 68, p. 351-358Article in journal (Refereed)
    Abstract [en]

    The quantitative penetration of three coldset wood adhesives [one-component polyurethane (PU), emulsion polymer isocyanate (EPI), poly (vinyl acetate) (PVAc)] under hydraulic pressure into different types of modified wood was studied using fluorescence microscopy and the results were compared to these of a previous study without pressure on adjacent wood samples. The effective penetration (EP) of PU was negatively affected by furfurlylation and NMM modification when pressure was applied. For PVAc, 30% NMM treatment and heat treatment of Scots pine and beech at 210 °C had a negative effect on its EP, but against this the EP of this adhesive increased after heat treatment of beech at 195 °C. In the case of furfurylation, the depth of penetration of all adhesives was less into wood treated with higher concentration of furfuryl alcohol. PU showed a much deeper penetration into NMM-modified and heat-treated wood than the other adhesives with the exception of heat-treated beech at 195 °C. Application of pressure led to rather different results as compared to the EP data when no pressure was applied. The three-dimensional (3D) visualisation of the penetration of PU adhesive into heat-treated Scots pine was also examined by X-ray micro-computed tomography (XµCT). The 3D flow pattern of PU adhesive into heat-treated Scots pine was clearly depicted by XµCT.

  • 39.
    Bastani, Alireza
    et al.
    University of Göttingen, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Militz, Holger
    University of Göttingen, Germany.
    Effect of open assembly time and equilibrium moisture content on the penetration of polyurethane adhesive into thermally modified wood2017In: The journal of adhesion, ISSN 0021-8464, E-ISSN 1563-518X, Vol. 93, no 7, p. 575-583Article in journal (Refereed)
    Abstract [en]

    The effect of wood moisture content and open assembly time on penetration of polyurethane (PU) adhesive into thermally treated Scots pine (195 and 210°C) was investigated according to effective (EP) and maximum penetration (MP) measurements using fluorescence microscopy. For samples treated at 195°C, a higher EP was noted at 8.6% equilibrium moisture content (EMC) after both assembly times (15 and 30 min) while for samples treated at 210°C, increasing wood moisture content resulted in a significant decrease in EP at 12.5% EMC after 15 min assembly time. Extending open assembly time was found to increase the EP of PU adhesive only in the case of samples treated at 195°C and with 8.6% EMC. For samples treated at both treatment temperatures and after shorter open assembly time, the highest MP observed at moderate EMC levels of 8.6 and 8.2% and the lowest at the higher EMC levels of 13.2 and 12.5%.

  • 40.
    Bastani, Alireza
    et al.
    Georg-August-University Göttingen, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Militz, Holger
    Georg-August-University Göttingen, Germany.
    Gross adhesive penetration in furfurylated, N-methylol melamine-modified and heat-treated wood examined by fluorescence microscopy2015In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 73, no 5, p. 635-642Article in journal (Refereed)
    Abstract [en]

    This study investigated the radial penetration of three conventional cold-set wood adhesives [emulsion polymer isocyanate (EPI), poly (vinyl acetate) (PVAc), one-component polyurethane (PU)] into various degrees of furfurylated and N-methylol melamine-modified (NMM) Scots pine, and heat-treated Scots pine and beech based on measurements of effective (EP) and maximum penetration (MP) from microscopic observations. EP of EPI adhesive decreased after modification with higher concentration of furfuryl alcohol while an improved penetration was recorded for PVAc into furfurylated wood. A deeper penetration was observed for all adhesives into wood treated with lower concentration of furfuryl alcohol. The EP of EPI and PU adhesives reduced after NMM treatment but it increased in the case of PVAc. In spite of reduction of EP of PU after NMM treatment, it represented a deeper penetration among all adhesives possibly due to its lower molecular weight. For Scots pine, increasing the treatment temperature improved EP of all adhesives while for beech, the EP of PU and PVAc increased largely in the case of samples treated at 195 °C. Visual analysis of fluorescence microscopy pictures provided more detailed information on modality of penetration. The results are useful for understanding the interaction among common adhesives and modified materials, and can be used in future research to explain the bonding behavior of modified wood.

  • 41.
    Bastani, Alireza
    et al.
    University of Göttingen, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Militz, Holger
    University of Göttingen, Germany.
    Shear strength of furfurylated, N-methylol melamine and thermally modified wood bonded with three conventional adhesives2017In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 12, no 4, p. 236-241Article in journal (Refereed)
    Abstract [en]

    The shear strength of furfurylated, N-methylol melamine (NMM) and thermally modified wood bonded with emulsion polymer isocyanate, polyvinyl acetate (PVAc), and polyurethane (PU) adhesives was examined. Furfurylation and NMM modification of Scots pine had a significant negative effect on the bonding strength with all adhesives irrespective of the treatment intensity. The obtained low-shear strength values were related to the brittle nature of the wood after modifications rather to the failure of the bondline. PVAc showed a better bonding performance with both furfurylated and NMM modified wood while the combination of furfurylated wood and PU gave the highest reduction in bonding strength (47–51%). Shear strength also decreased significantly after thermal modification in both Scots pine (36–56%) and beech (34–48%) with all adhesives. With the exception of thermally modified beech samples bonded with PU, bondline was found to be the weakest link in thermally modified wood as it was revealed by the wood failure surfaces. Bondline thickness and effective penetration of adhesives did not relate to the shear strength of all modified wood materials. The lower shear strength of modified wood could be attributed to other factors, such as the reduced chemical bonding or mechanical interlocking of adhesives, and the reduced strength of brittle modified wood substrate.

  • 42.
    Bastani, Alireza
    et al.
    Georg-August-University Göttingen, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Militz, Holger
    Georg-August-University Göttingen, Germany.
    Water uptake and wetting behaviour of furfurylated, N-methylol melamine modified and heat-treated wood2015In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 73, no 5, p. 627-634Article in journal (Refereed)
    Abstract [en]

    This study reports on the water uptake (WU) and wetting properties of different modified wood materials; furfurylated and N-methylol melamine (NMM) modified Scots pine, and heat-treated (Vacu3 method) Scots pine and beech. All modifications caused a substantial reduction in WU in the longitudinal, tangential and radial directions both after short (24 h) and long contact times (168, 336 h) with a saturated sponge. The water uptake coefficient (w t ) was reduced by approximately 71–89 % in furfurylated wood, with the higher weight percent gain (WPG) providing a slightly greater reduction. The reduction in WU was not found to depend on the NMM solid content. The NMM treatment had the maximum effect on the reduction of tangential w t by 80–84 % and was much smaller in the longitudinal direction (31–68 %). The treatment temperature of 195 °C gave lower WU values than treatment at 210 °C, and the only exception was the radial direction of Scots pine. The longitudinal w t of heat-treated beech represented the highest reduction by 81–89 %, while radial w t was less affected in both species. Sessile drop apparent contact angles for water and diidomethane and corresponding surface energies on planed tangential and radial wood surfaces revealed an increased hydrophobicity and reduced polarity of modified wood. Furfurylated and NMM modified tangential surfaces had a higher increase of apparent contact angles than the radial surfaces but this was not observed in the case of heat treatment. Heat-treated wood showed reduced wetting of surfaces only with water. Apparent contact angles did neither differ with treatment temperature nor with the NMM resin load. The disperse component of surface energy was slightly increased by 20 % maximum in modified wood, while the polar components showed a dramatic decrease by −30 to −90 % with no major differences among treatments and intensities, and between surfaces. The results provide a better understanding of the hygroscopic behaviour of modified wood, which might be useful to predict its adhesion with various polymers such as glues, coatings and paints.

  • 43.
    Bastani, Alireza
    et al.
    George-August University, Germany.
    Militz, Holger
    George-August University, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Rohumaa, Anti
    Alto University School of Chemical Technology, Finland.
    Development of bonding strength of modified birch veneers during adhesive curing2016In: Wood research, ISSN 1336-4561, Vol. 61, no 2, p. 205-214Article in journal (Refereed)
    Abstract [en]

    This study investigated the bonding strength development of furfurylated, N-methylolmelamine (NMM) modified and thermally treated birch veneers glued with hot curing phenolformaldehyde (PF) adhesive in different pressing (20, 160 s) and open assembly times (20 s, 10min). For testing, the automated bonding evaluation system ABES was used with 2 N.mm-2applied pressure at 130°C. The bonding strength of both modified and unmodified samplesincreased significantly by prolongation of the pressing time from 20 to 160 s in all cases andfor both open assembly times. A deviation was observed for the samples treated at 220°C andat 20 s open assembly time. With the exception of NMM modified veneers, bonding strengthdid not change significantly by increasing the assembly time in the case of 20 s pressing forboth modified and unmodified samples. At 160 s pressing time, extension of the assembly timedeveloped a better bonding for controls, NMM modified and thermally treated veneers at 180°C.The combination of 10 min assembly time and 160 s pressing time proved as the optimal bondingcondition for controls, NMM modified and thermally treated veneers at 180°C while the highestbonding strength was noted in 20 assembly time and 160 s pressing time for furfurylated veneers.In most of the cases modification affected negatively the bonding performance of the veneers, inparticular for furfurylated and NMM modified samples.

  • 44.
    Benjaminsson, Erik
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Åslund, Victor
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Höstplantering av tall - Ett komplement till vårplantering?2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project was conducted in spring 2017, commissioned by Södra forest association, to investigate whether autumn planting of pine gives a good regeneration result and can be seen as an equivalent alternative to planting in spring. Traditionally, most of the plantings is completed in spring, but in order to achieve a more even distribution of labor over the year, it is interesting to investigate whether or not the autumn planting of pine can be successful.

    The survey was carried out as a survey study, where plants planted both in autumn 2014 and in spring 2015, formed the basis of data collection. A total of 38 sites were investigated, half of study object were planted in spring and half in autumn Sites were then compared in pairs regarded to plant type, site index, game treatment, soil moisture and blockiness. On each site 20 plots were laid out with a radius of 2.82, which gives a sample area of 25 m2. In each sample area following characteristics for each plant were measured; stem diameter, leeding shot length, total length, possible damage and possible dead plants and cause of plant death.

    Autumn planting of pine had a higher mortality than spring plantations, and the pine weevil caused highest mortality, followed by wildlife grazing and drought. The plantation grew slightly better for spring-planted seedlings, but it was only the leeding shot length that had a significant higher growth. The damage caused by pine weevil was similar for planting in autumn and spring, while the wildlife grazing was twice as high in autumn-planted areas compared to the spring planted. 

  • 45.
    Berg, Linus
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Skogsägares och jägares syn på älgbetesskador i Jönköpings län2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Scots pine (Pinus sylvestris) is an important food source for the moose (Alces alces) during winter. Scots pine is also one of the most important tree species for the Swedish timber- and pulpwood industry. The debate between hunters and forest owners, their thoughts about the magnitude of the moose population, and the extent of browsing damage, is background to this study that examined how the groups forest owners who hunts, forest owners who doesn’t hunt and hunters who doesn’t own any forest land thought about browsing damages and its consequences in Jönköping County, Sweden. Data was collected using a questionnaire and analyses were made on answers from 258 respondents. The results showed that the assessment of the extent of browsing damage differed significantly between the groups, where forest owners who doesn’t hunt assessed the extent of browsing damage the highest, hunters who doesn’t own any forest land assessed the extent as lowest, while forest owners who hunt was intermediate between the two other groups. The results also showed that there was a relation between how the respondents assessed the extent of browsing damage and their thoughts about how large the moose population should be.

  • 46.
    Bergh, Johan
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Skogsbruk2015In: Klimatsäkrat Skåne / [ed] Hall, M, Lund, E & Rummukainen, M, Lund, Sweden: Centrum för miljö- och klimatforskning, Lunds Universitet , 2015, p. 111-120Chapter in book (Other academic)
  • 47.
    Berglind, Lennart
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Skogsägares uppfattning om tillväxtdata i skogsbruksplaner2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    SAMMANFATTNING

    Skogens tillväxt är naturligtvis en central och grundläggande aspekt i skogsbruk

    och själva grunden för ett lönsamt skogsägande. Frågan är i vilken utsträckning

    skogsägare använder sig av data om tillväxt i skogsbruksplaner, och om de

    upplever att dessa uppgifter är väsentliga och användbara. Eller kan det finnas

    alternativa sätt att presentera tillväxt och kanske även annan typ av information i

    skogsbruksplanerna som bedöms som minst lika värdefull?

    Denna studie försökte främst ta reda på vilken tilltro skogsägarna fäster vid data

    om tillväxt i skogsbruksplaner. Svaren pekade mot att skogsägarna hyste en

    relativt stor tilltro till tillväxt angivet som ett numeriskt värde (3,47 av 5 poäng)

    och även till dess substantiella informationsvärde, men att även annan

    beståndsinformation som exempelvis åtgärdsförslag bedömdes som minst lika

    viktig.

    Felkällorna vid bestämning av ståndortsindex och bonitet kan vara ganska

    betydande, och det mest osäkra är vid översättning från ståndortsindex till

    bonitet. Detta kan sedan bidra till att ge en felaktig bild av värden på tillväxt,

    liksom det faktum att kvaliteten på, och användbarheten av inventeringsdata

    tydligt försämras över tid.

    Det är tydligt att det är svårt att sätta en sann siffra på kommande skoglig

    tillväxt. Kanske är det mest tillförlitligt att ange tillväxt som ett relativt värde i

    procent av aktuell stående volym, och som uppskattas för exempelvis fem år

    framåt? Att ange tillväxten i m3sk/ha och år kan ses som mera oprecist och

    momentant. Visarprocent kan vara en användbar indikator i skogsbruksplaner på

    den tillväxt som finns i bestånden, och som avser att genom rangordning jämföra

    olika bestånds räntabilitet. Ett annat sätt att beskriva beståndens utveckling mot

    timmerträd kan vara att skapa ett värde för formtalsutvecklingen, och att

    skogsägaren därmed på sikt kan jämföra dessa värden med tidigare mätningar.

    Det kan vara intressant för en skogsägare med en nyupprättad plan att få muntlig

    information om begreppen bonitet, tillväxt, visarprocent och formtal, och hur de

    konkret kan kopplas till den egna skogsmarken på både bestånds- och

    fastighetsnivå vid inventeringstillfället. Det bör vara ett bra läge vid den

    tidpunkten att erbjuda dessa upplysningar, troligen som en debiterad

    tilläggstjänst i samband med planläggningen.

    En tydlig insikt av studien är att det är just den säkerställda kvaliteten på

    beståndsdata, liksom hur färska inventeringsdata är, som är de enskilt viktigaste

    faktorerna för att få högkvalitativ information om inte minst skoglig tillväxt i

    skogsbruksplaner

  • 48.
    Berglund, Marie
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Röjningsformen och stamantalets effekt på höjd- och diametertillväxt i toppröjda och konventionellt röjda tallbestånd.2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Topping is a precommercial thinning (PCT) method where secondary stems are cut higher above the ground compared to conventional PCT. The secondary stems continue to live for a period and are supposed to compete with the main stems and promote their quality.

    The objective of the study was to compare the effect of PCT on height and diameter growth between topping and conventional PCT. The study also analysed the relationship between height and diameter growth and the number of stems after PCT.

    Nine topped stands and six conventional precommercially thinned stands were visited between February 28th and March 5. One sample plot per hectare was laid out in the investigated stands. In every sample plot the number of stems was counted and five main stems were measured for height, height growth since PCT, diameter and diameter growth since PCT.

    The results showed significantly higher effect on height growth after topping as compared to conventional PCT but no significant difference in the effect of diameter growth between topping and conventional PCT. After PCT the H/D quote (height/diameter quote) was higher (less taper) in topped stands and lower (larger taper) in conventional PCT.

  • 49.
    Bergqvist, Anna
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Trädslagsval och trädslagsförändring i Krånge mellan åren 1864 – 2010/20112013Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [sv]

    Syftet var att beskriva trädslagsförändringen i Krånge skog under perioden 1864 – 2010/2011. Vidare att reda ut var utvecklingen leder, - hur resonerar dagens skogsägare vid trädslagsval och vad styr dem? För att besvara frågorna jämfördes en Laga skifteskarta från år 1864 med ett ortofoto från 2010/2011. Vidare skickades en enkät ut till 18 skogsägare i Krånge.

    Resultatet visade att många avdelningar bevuxna med gran i mitten av 1800-  talet har ersatts med tall. Skogsägarna valde trädslag främst utifrån ståndortens egenskaper och tidigare trädslag på platsen. Valet påverkades inte av eventuella skaderisker eller andra orsaker. 

  • 50.
    Björcman, Frida
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Drivkrafter, innehåll och upplevelser av aktivism i skogliga konflikter2019Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Situations and behaviors can create conflicts between people and/or organizations based on a need of resources or a conflict of interest. Using activism in a conflict can be value based and is driven by a person's opinions and norms. The changed forest policy since the seventies has resulted in a greater interest in protecting forests, both from the authorities and from interest groups. The high proportion of privatelyowned forests and the increased interest have created several major conflicts over thepast ten years in Sweden, where the land owner has ended up between interest groups and authorities.The study aims to explain and create an understanding of how different sides reason in forest conflicts with activism, based on content, driving forces and experiences. Data-collection was done through 8 deep interviews. Respondents belonged to a government agency, three forest companies / forest owner associations, two individual forest owners and two nature conservation organizations. Thematic content analysis was performed on the collected material.There were differences in the value base where authorities and landowners did not value the ecological values as important to the same extent as forest companies/forest owner associations and interest groups, which in turn creates a risk of conflicts. About future activism, four respondents considered that it would increase, while three felt that it would decrease and one that it will be like today. In seven out of eight cases, it was an interest organization that initiated the conflict. Authorities, forestry companies / forest owner associations and landowners all considered that the information received from the interest groups was a good basis. A driving force that was identified was the need to assume responsibility, which originates from the driving force. The action in the conflicts was defined by the interest groups as a responsibility, while the parties who had experienced the activism defined the action as a high pressure. The experiences of activism that emerged were described by the landowners as an unpredictability and the interest groups as a vulnerability because of their deviant opinion. Authorities and forestrycompanies/forest owner associations described activism as a reluctance/ignorance. The negative and positive aspects of activism weigh in principle equally for all respondents. Authorities, interest groups and forestry companies/forest owner associations all mentioned a need for system change, as the political short-term and the inertia of the system was emphasized as a problem. From all sides a collaboration was desired, where a factual dialogue must be the basis. One can ask how important the interest organizations are for the development of forestry when the material produces by them is considered good quality? And is it the forest owners who must get run overwhen the policy is short-term? Forestry companies/forest owner associations and authorities report their responsibility towards the citizens and that there were information deficiencies. By improving the dialogue and the information there is an opportunity to find ways to reach each other. This is to get a better overall view of how the different sides reason and what everyone's values are. Based on this, conflicts can hopefully be fewer in the Swedish forests.

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