Håkan Lindström - Academia.edu (original) (raw)
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Papers by Håkan Lindström
Wood Science and Technology, 2004
... SLU, Box 7060, 750 07, Uppsala, Sweden E-mail: lindstromhakan@netscape.net Æ Tel.: +64-03-364... more ... SLU, Box 7060, 750 07, Uppsala, Sweden E-mail: lindstromhakan@netscape.net Æ Tel.: +64-03-3648114 P. Harris Industrial Research Limited ... of juvenile wood, has a negative effect on the production costs and revenue of forest products (Kretschmann and Bendtsen 1992; Ken ...
Holzforschung, 1998
... of wood (Harris and Meylan 1965; Meylan 1968; Barrett et al. 1972; Boyd 1983; Watanabe and No... more ... of wood (Harris and Meylan 1965; Meylan 1968; Barrett et al. 1972; Boyd 1983; Watanabe and Notimoto 1994; Ying et al. 1994; Persson 1997). and the mechanical properties of wood (Schniewind 1966; Cave 1968; Meylan 1968; Mark and Gillis 1973; Megraw 1985; Bendtsen ...
Holz als Roh- und Werkstoff, 2003
The cell wall of wood tracheids is made up of various layers, distinguished from one other by the... more The cell wall of wood tracheids is made up of various layers, distinguished from one other by the alignment of the innumerable, fine crystalline cellulose microfibrils within each layer that helically wind about the cell lumen. Microfibrils themselves are embedded in a die den Durchschnitts-Mikrovibrillenwinkel in einem gegebenen Holzstück reflektiert. Aufgrund dessen wurden akustische Methoden entwickelt, um die Geschwindigkeit der Schallausbreitung zu messen, die direkt mit der Festigkeit des Holzes korreliert und damit auch abhängig ist von der Ultrastruktur der Zellwand. In der Grundgleichung, E dynamic =qV 2 , wird der akustische Modulus von zwei Komponenten abgeleitet, der Dichte, q, und der Schallgeschwindigkeit, V. Letztere bezieht sich auf die intrinsische Holzqualität und die Ultrastruktur der Tracheiden-Wand. Es wird gezeigt, dass die akustische Methode in der Lage ist, Bäume und Rundholz gemäß ihrer Eignung für Bauholz und für eine Bandbreite von Fasereigenschaften, im Interesse der Papierhersteller, zu sortieren und einzuteilen. Auf diese Weise finden akustische Methoden Anwendung bei der Aufzucht von Bäumen, ihrer Abholzung und Verarbeitung.
Holz als Roh- und Werkstoff, 2002
There is a need to determine stiffness at an early age, to help capture genetic breeding opportun... more There is a need to determine stiffness at an early age, to help capture genetic breeding opportunities for better structural lumber. The current study investigates the possibility of selecting Pinus radiata clones with high modulus of elasticity (MOE). Various ways of measuring MOE are examined: traditional static bending, axial compression of bolts, existing sonic methods, as well as a tool specifically configured for resonance on short bolts. Wood characteristics and microfibril angle are measured on discs taken from each tree. Results show a good correlation between acoustic and static measurements of modulus of elasticity. Moreover, the selected seven radiata clones differ in stiffness by a factor of two, and much of this variation seems to relate to differences in microfibril angle. The results validate the assumption that there is potential to improve wood stiffness of radiata pine genetically. This work does not offer definitive solutions but explores a number of approaches that could be utilised as a selection tool in tree breeding for better product performance of radiata lumber. Here, development of methods based on acoustics is shown to assist in the necessary mass screening of clones for stiffness properties.
Wood Science and Technology, 2004
... SLU, Box 7060, 750 07, Uppsala, Sweden E-mail: lindstromhakan@netscape.net Æ Tel.: +64-03-364... more ... SLU, Box 7060, 750 07, Uppsala, Sweden E-mail: lindstromhakan@netscape.net Æ Tel.: +64-03-3648114 P. Harris Industrial Research Limited ... of juvenile wood, has a negative effect on the production costs and revenue of forest products (Kretschmann and Bendtsen 1992; Ken ...
Holzforschung, 1998
... of wood (Harris and Meylan 1965; Meylan 1968; Barrett et al. 1972; Boyd 1983; Watanabe and No... more ... of wood (Harris and Meylan 1965; Meylan 1968; Barrett et al. 1972; Boyd 1983; Watanabe and Notimoto 1994; Ying et al. 1994; Persson 1997). and the mechanical properties of wood (Schniewind 1966; Cave 1968; Meylan 1968; Mark and Gillis 1973; Megraw 1985; Bendtsen ...
Holz als Roh- und Werkstoff, 2003
The cell wall of wood tracheids is made up of various layers, distinguished from one other by the... more The cell wall of wood tracheids is made up of various layers, distinguished from one other by the alignment of the innumerable, fine crystalline cellulose microfibrils within each layer that helically wind about the cell lumen. Microfibrils themselves are embedded in a die den Durchschnitts-Mikrovibrillenwinkel in einem gegebenen Holzstück reflektiert. Aufgrund dessen wurden akustische Methoden entwickelt, um die Geschwindigkeit der Schallausbreitung zu messen, die direkt mit der Festigkeit des Holzes korreliert und damit auch abhängig ist von der Ultrastruktur der Zellwand. In der Grundgleichung, E dynamic =qV 2 , wird der akustische Modulus von zwei Komponenten abgeleitet, der Dichte, q, und der Schallgeschwindigkeit, V. Letztere bezieht sich auf die intrinsische Holzqualität und die Ultrastruktur der Tracheiden-Wand. Es wird gezeigt, dass die akustische Methode in der Lage ist, Bäume und Rundholz gemäß ihrer Eignung für Bauholz und für eine Bandbreite von Fasereigenschaften, im Interesse der Papierhersteller, zu sortieren und einzuteilen. Auf diese Weise finden akustische Methoden Anwendung bei der Aufzucht von Bäumen, ihrer Abholzung und Verarbeitung.
Holz als Roh- und Werkstoff, 2002
There is a need to determine stiffness at an early age, to help capture genetic breeding opportun... more There is a need to determine stiffness at an early age, to help capture genetic breeding opportunities for better structural lumber. The current study investigates the possibility of selecting Pinus radiata clones with high modulus of elasticity (MOE). Various ways of measuring MOE are examined: traditional static bending, axial compression of bolts, existing sonic methods, as well as a tool specifically configured for resonance on short bolts. Wood characteristics and microfibril angle are measured on discs taken from each tree. Results show a good correlation between acoustic and static measurements of modulus of elasticity. Moreover, the selected seven radiata clones differ in stiffness by a factor of two, and much of this variation seems to relate to differences in microfibril angle. The results validate the assumption that there is potential to improve wood stiffness of radiata pine genetically. This work does not offer definitive solutions but explores a number of approaches that could be utilised as a selection tool in tree breeding for better product performance of radiata lumber. Here, development of methods based on acoustics is shown to assist in the necessary mass screening of clones for stiffness properties.