2006 Fiscal Year Final Research Report Summary
Ultrastructure in Relation to the Mechanical Optimization of Trees
| Project/Area Number |
17580142
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林産科学・木質工学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
SUGIYAMA Junji KYOTO UNIVERSITY, Research Institute for Sustainable Humanosphere, Professor, 生存圏研究所, 教授 (40183842)
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| Project Period (FY) |
2005 – 2006
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| Keywords | biomechanics / cel lulose / growth stress / lattice strain |
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| Research Abstract |
In order to understand the mechanical state and function of cellulose microfibrils/crystallites in the tension wood, we have performed a crystallographic approach to compare the strains at molecular level to the macroscopic level. We have demonstrated experimentally for the first time that the fiber repeat distance of cellulose microfibrils/crystallites is larger in tension wood in situ than after the release of the maturation stress. Therefore, the contraction of the cellulose microfibrils/crystallites during the release of maturation stress was confirmed and it was as much as the macroscopic strain was. However, it is still open whether cellulose microfibrils/crystallites in tension wood are generating the maturation stress. The alternative assumption is that they have a larger equilibrium fiber repeat distance, due to a larger crystal size.
So far, though many studies were carried out to observe the width of cellulose microfibrils/crystallites in tension wood, values range between 2 and 7 nm depending on the technique and sample preparation. Therefore, it is prerequisite to increase the precision of the measurement. In addition, data on the size together with (004) spacing of wood cellulose which are crystallized under different physical or physiological condition would shed a light on a better understanding of cellulose structure and its mechanical state in wood
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