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Visar resultat 1 - 5 av 158 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Development towards an efficient and sustainable biofuel drying

   Författare :Peter Bengtsson; Thomas Thörnqvist; Tom Morén; Växjö universitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; biomass; bioenergy; drying; bed drying; drying zone; modeling; VOC; terpenes; wood fuels; wood chips; sawdust; Norway spruce; Scots pine;

   Sammanfattning : The usage of biofuel as well as wood fuel has increased in Sweden and all of Europe during recent decades, and there are several reasons to believe that this increase will continue. An important reason for this increase is that the environmental and climate problems caused by fossil fuels are becoming even more evident. LÄS MER

3. 2. Industrial Wood Drying : Airflow Distribution, Internal Heat Exchange and Moisture Content as Input and Feedback to the Process

   Författare :Tommy Vikberg; Mihaela Campean; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Träteknik; Wood Technology;

   Sammanfattning : At a sawmill, the most energy demanding process is the wood drying. The drying process also has a great impact on quality parameters determined for the boards in the final sorting and thereby affects the sales value to a great extent. LÄS MER

4. 3. 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

5. 4. Multiphase continuum modeling of wood : A hybrid mixture theory approach

   Författare :Winston Mmari; Björn Johannesson; Lynn Schreyer; Linnéuniversitetet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Moisture transport; Coupled heat and moisture; Over-hygroscopic; Hybrid mixture theory; Mixture theory; Swelling; Hygro-mechanical; Non-linear elasticity; Large deformation; Phase field crack model; Anisotropic cracking; FEM; Numerical model; Norway spruce; Wood; Porous media; Forestry and Wood Technology; Skog och träteknik;

   Sammanfattning : Wood has been used as a construction material for a very long time. The development of efficient industrial production processes of wood has expanded the use of the material with the introduction of new products, such as engineered wood products. LÄS MER

7. 5. Drying and Pyrolysis of Logs of Wood

   Författare :Jenny Larfeldt; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; structural changes; heat transfer properties; pyrolysis; drying; single particle; wood;

   Sammanfattning : This work concerns log firing in small-scale boilers for house heating, which in Sweden meets a heat demand of 12 TWh a year. In boilers used for domestic central heating in the sizes of 10 to 30 kW the predominant combustion technique is grate firing. LÄS MER