Search for dissertations about: "laser agriculture"

Showing result 1 - 5 of 22 swedish dissertations containing the words laser agriculture.

  2. 1. Adhesion to machined and laser ablated wood surfaces

    Author : Micael Stehr; KTH; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; ablation; adhesion; checks; coating; cracks; excimer laser; gluing; IR laser; mechanical machining; mechanical weak boundary layer; microscopy; notched specimens; pine; planing; sample preparation; sawing; scanning electronmicroscopy; spruce; tip-cracks; UV laser; weak boundary layer; wood;

    Abstract : This thesis is a contribution to the R&D-program ValueActivation at KTH,Division of Wood Technology and Processingand containsfive papers related to the evaluation and development ofmachining techniques (mechanical and irradiation treatments)whereby weak boundaries at the wood surfaces in the form of(mechanical) weak boundary layers and (micro) cracks due tomechanical treatment can be avoided.The first paper describes the development of a method–using a UV laser–to study the mechanically weakenedboundaries. READ MORE

  4. 2. Mapping and monitoring of vegetation using airborne laser scanning

    Author : Mattias Nyström; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Abstract : In this thesis, the utility of airborne laser scanning (ALS) for monitoring vegetation of relevance for the environmental sector was investigated. The vegetation characteristics studied include measurements of biomass, biomass change and vegetation classification in the forest-tundra ecotone; afforestation of grasslands; and detection of windthrown trees. READ MORE

  5. 3. Local variation in bending stiffness in structural timber of Norway spruce : for the purpose of strength grading

    Author : Min Hu; Marie Johansson; Linnéuniversitetet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; digital image correlation; fibre angle; high resolution; laser scanning; local stiffness; MOE profile; mode shape curvature; strain field; strength grading; structural timber; tracheid effect; Digital image correlation; fibervinkel; laserskanning; lokal styvhet; MOE-profil; töjningsfält; hållfasthetssortering; konstruktionsvirke; trakeideffekt; Forestry and Wood Technology; Skog och träteknik;

    Abstract : Most strength grading machines on the European market use an averagemodulus of elasticity (MOE), estimated on a relatively large distance along awood member, as the indicating property (IP) to bending strength. Theaccuracy of such grading machines in terms of coefficient of determination israther low at R2 ≈ 0.5. READ MORE

  6. 4. Strength grading of structural timber and EWP laminations of Norway spruce : Development potentials

    Author : Jan Oscarsson; Anders Olsson; Marie Johansson; Mikael Perstorper; SP Sveriges Tekniska Forskningsinstitut; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; bending strength; fibre angle; grain angle; knots; laser scanning; machine strength grading; modulus of elasticity; strain measurement; structural timber; tensile strength; wood; böjhållfasthet; draghållfasthet; elasticitetsmodul; fibervinkel; konstruktionsvirke; kvistar; laserskanning; maskinell hållfasthetssortering; trä; töjningsmätning; Byggteknik; Civil engineering;

    Abstract : Strength grading of structural timber is a process by which value is added to sawn products. It is to the greater part carried out using machine grading based on statistical relationships between so called indicating properties and bending strength. READ MORE

  7. 5. Studies of the fibre direction and local bending stiffness of Norway spruce timber : for application on machine strength grading

    Author : Min Hu; Marie Johansson; Mats Ekevad; Linnéuniversitetet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; digital image correlation; diving angle; fibre angle; grain angle; indicating property; laser scanning; modulus of elasticity; tracheid effect; Forestry and Wood Technology; Skog och träteknik;

    Abstract : Machine strength grading is a production process in the sawmill industry used to grade sawn timber boards into different strength classes with specific characteristic values of the bending strength, modulus of elasticity (MOE) and density. These properties are called grade determining properties. READ MORE