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Visar resultat 1 - 5 av 125 avhandlingar som matchar ovanstående sökkriterier.

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

   Författare :Sara Florisson; Sigurdur Ormarsson; Johan Vessby; Kent Persson; Linnéuniversitetet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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;

   Sammanfattning : 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. LÄS MER

3. 2. Engineering of lignin in wood towards functional materials

   Författare :Gabriella G. Mastantuoni; Qi Zhou; Lars Berglund; Jean-Marie Raquez; KTH; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cellulose; wood; nanotechnology; sulfonation; biocomposite; cross-linking; densification; transparent film; wood foam; conductivity; Cellulosa; trä; nanoteknologi; sulfonering; biokomposit; tvärbindning; förtätning; transparent film; poröst trämaterial; konduktivitet; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Sammanfattning : Through 270 million years of evolution, the finely tuned hierarchical structure of wood has been optimized for efficient nutrient transport and exceptional mechanical stability. Its distinctive orthotropic constitution can provide inspiration and design opportunities for the development of novel functional materials. LÄS MER

4. 3. Strategic raw material supply for the particleboard-producing industry in Europe : Problems and challenges

   Författare :Johann Trischler; Johan Bergh; Rupert Wimmer; Linnéuniversitetet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Biomass production; Lignocellulosic raw material; Non-wood plants; Particleboard; Pulp and paper; Recycling; Thermal energy recovery; Wood plants; Forestry and Wood Technology; Skog och träteknik;

   Sammanfattning : Particleboard was invented to increase the utilization of wood and it soon became an important core material for furniture production. Nowadays, other industries such as the pulp and papermaking industry and the thermal energy recovery industry claim the same type of raw material. LÄS MER

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

   Författare :Jennie Berglund; Mikael Lindström; Gunnar Henriksson; Francisco Vilaplana; Jakob Wohlert; Martin Lawoko; Maija Tenkanen; KTH; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LANTBRUKSVETENSKAPER; 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;

   Sammanfattning : 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. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER