Search for dissertations about: "Wood Science and Engineering"

Showing result 1 - 5 of 130 swedish dissertations containing the words Wood Science and Engineering.

  1. 1. Mechanical properties of sound and of deteriorated softwood at different length scales : Poromicromechanical modeling and experimental investigations

    Author : Thomas K. Bader; Karin Hofstetter; Kristofer Gamstedt; Austria Vienna University of Technology; []
    Keywords : AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; AGRICULTURAL SCIENCES; Byggteknik; Civil engineering; Forestry and Wood Technology; Skog och träteknik;

    Abstract : Due to its natural origin and its inherent heterogeneities, mechanical properties of wood are highly anisotropic and show a broad variability, not only between different wood species, but also within a tree. Similar to other biological materials, the wood mi- crostructure is well organized and hierarchically structured from the annual rings visible to the naked eye down to the wood polymers cellulose, hemicellulose, and lignin at the nanometer-scale. READ MORE

  2. 2. Moisture-induced stress and distortion of wood : A numerical and experimental study of wood's drying and long-term behaviour

    Author : Sara Florisson; Sigurdur Ormarsson; Johan Vessby; Kent Persson; Linnéuniversitetet; []
    Keywords : AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; AGRICULTURAL SCIENCES; analytical method; calibration; controlled climate; creep; distortion; experimental methodology; FEM; fibre orientation; mechano-sorption; moisture transport; natural climate; Norway spruce; numerical model; three-dimensional; timber beam; validation; wood; Byggteknik; Civil engineering; Forestry and Wood Technology; Skog och träteknik;

    Abstract : With the current advances made in three-dimensional modelling of wood, it is possible to provide an overall picture of moisture flow, and moisture-induced stress and deformations, whereas previously, experiments only provided local measurements. The main aim of the doctoral thesis is to investigate the possibilities of the developed three-dimensional numerical model to predict the behaviour of wood when simultaneously exposed to a mechanical load and a particular climate. READ MORE

  3. 3. Study of pyrolysis and gasification of biomass from the self-organization perspective

    Author : Aliaksandr Alevanau; Ersson Mikael; Weihong Yang; Pär Jönsson; Sylwester Kalisz; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; pyrolisys; pellets; hydrogen; gasification; Materials Science and Engineering; Teknisk materialvetenskap; Chemical Engineering; Kemiteknik;

    Abstract : This thesis focuses on the analysis of kinetics of i) low-temperature pyrolysis of gaseous hydrocarbons, ii) high-temperature steam gasification of char of wood pellets (>700oC), iii) high temperature pyrolysis of straw pellets in an atmosphere of argon and steam, and iv) high temperature pyrolysis of slices of transversally cut wooden sticks. The results of the kinetic measurements in the high-temperature cases are approximated using a least-square based optimization software, which was specially developed to analyse kinetics prone for deviation from the Arrhenius law. READ MORE

  4. 4. Nonlinear modeling of reinforced dowel joints in timber structures : a combined experimental-numerical study

    Author : Michael Schweigler; Josef Eberhardsteiner; Thomas K. Bader; Thierry Descamps; Vienna University of Technology; []
    Keywords : AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; AGRICULTURAL SCIENCES; Technology byts ev till Engineering ; Teknik; Byggteknik; Civil engineering; Forestry and Wood Technology; Skog och träteknik;

    Abstract : Steel dowels are indispensable elements for the design of joints in modern timber structures. Dowels are broadly used because of their flexibility in design and easy assembling on-site, as well as due to their advantageous mechanical behavior. READ MORE

  5. 5. Wood Hemicelluloses - Fundamental Insights on Biological and Technical Properties

    Author : Jennie Berglund; Mikael Lindström; Gunnar Henriksson; Francisco Vilaplana; Jakob Wohlert; Martin Lawoko; Maija Tenkanen; KTH; []
    Keywords : AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; NATURAL SCIENCES; NATURVETENSKAP; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; TEKNIK OCH TEKNOLOGIER; LANTBRUKSVETENSKAPER; LANTBRUKSVETENSKAPER; ENGINEERING AND TECHNOLOGY; AGRICULTURAL SCIENCES; AGRICULTURAL SCIENCES; hemicellulose; wood; glucomannan; xylan; structure; acetylation; flexibility; solubility; interaction with cellulose; stability.; hemicellulosa; trä; glukomannan; xylan; struktur; acetylering; flexibilitet; löslighet; interaktion med cellulosa; stabilitet.; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Abstract : Hemicelluloses are a group of heterogeneous polysaccharides representing around 30 % of wood where the dominating types are xylans, glucomannans and xyloglucans. Hemicelluloses complex molecular structure makes it difficult to understand the relationship between structure and properties entirely, and their biological role is not yet fully verified. READ MORE