Delayed recovery of growth stress in tension wood induced by drying and subsequent wetting treatment

2018 ◽  
Vol 52 (4) ◽  
pp. 1049-1060
Author(s):  
K. C. Sujan ◽  
Hiroyuki Yamamoto ◽  
Miyuki Ueda Matsuo ◽  
Masato Yoshida ◽  
Keiichi Asaka
Keyword(s):  
Tension Wood ◽  
Growth Stress ◽  
Delayed Recovery

CHARACTERISTICS OF TROCHODENDRON ARALIOIDES TENSION WOOD FORMED AT DIFFERENT INCLINATION ANGLES

IAWA Journal ◽  
2013 ◽  
Vol 34 (3) ◽  
pp. 273-284 ◽  
Author(s):  
Tokiko Hiraiwa ◽  
Tatsuya Toyoizumi ◽  
Futoshi Ishiguri ◽  
Kazuya Iizuka ◽  
Shinso Yokota ◽  
...  
Keyword(s):  
Tension Wood ◽  
Growth Promotion ◽  
Growth Stress ◽  
Aperture Angle ◽  
Wall Structure ◽  
Cellulose Content ◽  
Klason Lignin ◽  
Glucose Content ◽  
Gelatinous Layer ◽  
Inclination Angles

To assess the characteristics of tension wood (TW) in Trochodendron aralioides Sieb. et Zucc., seedling stems were artificially inclined at angles of 30° (TW- 30), 50° (TW-50), and 70° (TW-70) from the vertical. At all angles, the growth promotion was pronounced on the upper side of the inclined stems, where excessive tensile growth stress was observed. A gelatinous layer (G-layer) formed in the tracheids of TW. The cell wall structure of the tracheids in TW was S1 + G. The G-layer had a small pit aperture angle <10°. TW-50 showed larger tensile growth stress, a thicker G-layer area, and a smaller pit aperture angle of the Glayer than TW-30 and TW-70. Lower levels of Klason lignin and hemicellulose and higher levels of α-cellulose content were observed in TW-50. In addition, an increase in glucose content and a decrease in xylose content in holocellulose were observed in TW-50. Therefore, it can be concluded that the degree of TW varied with different inclination angles.

scholarly journals Tension Wood and Oppositewood in 21 Tropical Rain Forest Species

IAWA Journal ◽  
2006 ◽  
Vol 27 (4) ◽  
pp. 341-376 ◽  
Author(s):  
Julien Ruelle ◽  
Bruno Clair ◽  
Jacques Beauchêne ◽  
Marie Françoise Prévost ◽  
Meriem Fournier
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Tension Wood ◽  
Fibre Diameter ◽  
Microfibril Angle ◽  
Ultrastructural Level ◽  
Growth Stress ◽  
Opposite Wood ◽  
Two Samples ◽  
French Guyana

The anatomy of tension wood and opposite wood was compared in 21 tropical rain forest trees from 21 species belonging to 18 families from French Guyana. Wood specimens were taken from the upper and lower sides of naturally tilted trees. Measurement of the growth stress level ensured that the two samples were taken from wood tissues in a different mechanical state: highly tensile-stressed wood on the upper side, called tension wood and normally tensile-stressed wood on the lower side, called opposite wood. Quantitative parameters relating to fibres and vessels were measured on transverse sections of both tension and opposite wood to check if certain criteria can easily discriminate the two kinds of wood. We observed a decrease in the frequency of vessels in the tension wood in all the trees studied. Other criteria concerning shape and surface area of the vessels, fibre diameter or cell wall thickness did not reveal any general trend. At the ultrastructural level, we observed that the microfibril angle in the tension wood sample was lower than in opposite wood in all the trees except one (Licania membranacea).

scholarly journals Growth Stresses are Highly Controlled by the Amount of G-Layer in Poplar Tension Wood

IAWA Journal ◽  
2008 ◽  
Vol 29 (3) ◽  
pp. 237-246 ◽  
Author(s):  
Chang-Hua Fang ◽  
Bruno Clair ◽  
Joseph Gril ◽  
Sheng-Quan Liu
Keyword(s):  
Tension Wood ◽  
Growth Stress ◽  
Strain Level ◽  
Longitudinal Growth ◽  
Growth Strain ◽  
Growth Stresses ◽  
Tissue Area

To determine how gelatinous fibres and gelatinous layers contribute to the magnitude of longitudinal growth stress in tension wood, anatomical measurements of gelatinous fibres were carried out on poplar tension wood (Populus I4551). It was found that (a) no gelatinous fibres were observed under a growth strain level of 0.06 to 0.08%; (b) almost 100% of the non-conductive tissues contained gelatinous fibres above a growth strain level of 0.15 to 0.19%; and (c) the area of fibres, the area of fibres with gelatinous layers per unit of tissue area, and the thickness of the gelatinous layers predominantly influenced the magnitude of growth stress

Lean in red alder (Alnusrubra): growth stress, tension wood, and righting response

1996 ◽  
Vol 26 (11) ◽  
pp. 1951-1956 ◽  
Author(s):  
Brayton F. Wilson ◽  
Barbara L. Gartner
Keyword(s):  
Tension Wood ◽  
Wood Formation ◽  
Growth Stress ◽  
Lower Side ◽  
Growth Rings ◽  
Red Alder ◽  
Growth Stresses ◽  
Righting Response ◽  
Natural Stands ◽  
Old Trees

Natural stands and a 3-year-old plantation of red alder (Alnusrubra Bong.) trees were used to study the incidence of leaning stems, the level of growth stresses and tension wood formation, and the ability of the stems to right themselves to vertical. Overall, 10% of the 512 trees in 10 natural stands leaned >22°. The largest diameter trees on the steepest slopes leaned most. Most (61%) of the trees curved upward, showing a righting response. For samples without tension wood, growth stress levels on the upper side of leaning stems, but not on the lateral or lower sides, were positively correlated with lean angles above 6°. These leaning stems had a significant righting response without tension wood. Tension wood formation was variable at leans from 9° to 26° both within and among trees, but was correlated with eccentric growth rings. We measured stem recovery in the year-old stem of 3-year-old trees bent to angles of 0–37.5°. During the 5-month experiment all stems righted to near vertical. Tension wood formed on the upper side in stems bent >6°, but reversed to the lower side before reaching vertical in 22 of 30 trees.

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

Growth stress and interdiffusion analysis of NiCoCrAlYTa coating during oxidation

2020 ◽  
pp. 1-10
Author(s):  
Hongzhi Yang ◽  
Jianpeng Zou ◽  
Qian Shi ◽  
Zhongzhan Xu ◽  
Mingjiang Dai ◽  
...  
Keyword(s):  
Growth Stress

scholarly journals Effects of Roughness on Stresses in an Oxide Scale Formed on a Superalloy Substrate

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 479
Author(s):  
Yang Zhao ◽  
Fan Sun ◽  
Peng Jiang ◽  
Yongle Sun
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Residual Stresses ◽  
Oxide Scale ◽  
Rough Surface ◽  
Alumina Scale ◽  
Growth Stress ◽  
Oxide Growth ◽  
Substrate Thickness ◽  
Roughness Effect

The effects of surface roughness on the stresses in an alumina scale formed on a Fecralloy substrate are investigated. Spherical indenters were used to create indents with different radii and depths to represent surface roughness and then the roughness effect was studied comprehensively. It was found that the residual stresses in the alumina scale formed around the rough surface are almost constant and they are dominated by the curvature rather than the depth of the roughness. Oxidation changes the surface roughness. The edge of the indent was sharpened after oxidation and the residual stress there was released presumably due to cracking. The residual stresses in the alumina scale decrease with increase in oxidation time, while the substrate thickness has little effect, given that the substrate is thicker than the alumina scale. Furthermore, the effect of roughness on the oxide growth stress is analysed. This work indicates that the surface roughness should be considered for evaluation of stresses in coatings.

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