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Visar resultat 1 - 5 av 64 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Knots and Transport in Topological Matter

    Författare :Marcus Stålhammar; Emil Johansson Bergholtz; Christiane Morais Smith; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Transport; Knots; Topology; non-Hermiticity; Weyl semimetals; Theoretical Physics; teoretisk fysik;

    Sammanfattning : Topology has manifestations in physics ranging from the field of condensed matter to photonics. This dissertation provides a two-fold study on the impact of topology in Hermitian and non-Hermitian band structures. LÄS MER

  3. 2. Segmentation of knots : a problem in 3D X-ray scanning of logs

    Författare :Katarina Flood; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : This thesis investigates the possibilities of using 3D X-ray tomography to detect and segment knots in logs. In the sawmill process this should be done previously to the sawing the log into boards. LÄS MER

  4. 3. Modeling the effects of knots in Structural Timber

    Författare :Christina Foley; Avdelningen för Konstruktionsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material technology; Byggnadsteknik; Building construction; three-dimensional fiber paradigm; fiber deviation; knots; annual growth layer; material matrix; knot bump; structural timber; load carrying capacity; Materiallära; critical knot; knot distance ratio; local principal material directions; stiffness; materialteknik;

    Sammanfattning : The main purpose of the pursued research is to increase knowledge of the effects of knots in structural timber so that characteristics of weaker timber may be determined and applied to improve current grading techniques. In the process, a three-dimensional fiber paradigm was established, which describes variations of local principle material axes in timber containing knots. LÄS MER

  5. 4. Modelling and strength grading of structural timber and glulam lamellae on the basis of optical scanning and dynamic excitation

    Författare :Andreas Briggert; Anders Olsson; Jan Oscarsson; Mikael Perstorper; Linnéuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fibre direction; finger joint; machine strength grading; knots; tracheid effect; Norway spruce; Byggteknik; Civil engineering;

    Sammanfattning : Machine strength grading of sawn timber is a sawmill process in which density, modulus of elasticity (MOE) and bending or tensile strength are predicted such that the timber can be assigned to strength classes. The predictions of these properties are performed using one or several so-called indicating properties (IPs), which represent a board property, or combination of board properties, measured non-destructively. LÄS MER

  7. 5. Strength grading of structural timber and EWP laminations of Norway spruce : Development potentials

    Författare :Jan Oscarsson; Anders Olsson; Marie Johansson; Mikael Perstorper; SP Sveriges Tekniska Forskningsinstitut; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER