Fundamental Study on Wood Quality by Electrical Conduction and Gas Permeability

通过导电性和透气性对木材质量进行基础研究

基本信息

批准号：
61560197
负责人：
TSUTSUMI Juichi
金额：
$ 1.54万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61560197/
关键词：
Electrical conduction Gas permeability Wood quality Wood morphology 木材組織木材構造

项目摘要

The electrical conductivities and air permeabilities of 20 hardwood species and Larix were studied in relation to specific gravity and wood morphology in order to understand a fundamental aspect of the physical properties for evaluating wood quality.The conductivity at a given moisture content had large variation among species. On the other hand, the effect of moisture concentration per unit wood volume was highly correlated to basic density. Therefore the conductivity variation among species was assumed to be mainly caused by the difference of moisture retention with wood specific gravity and also by the physical change of adsorbed water with moisture retention. The intra-structure of cell wall and the cell dimension may be another factors in the difference among species, because the conductivity of cell wall itself was shown to have the variation among species and to be correlated to average microfibril angle in tracheid. The results suggested that, if the relationship between moistu … More re retention and wood structure was sufficiently realized, conductivity could be a reasonable index for specific gravity as well for moisture content.Although vessel element element and tracheid were supposed to be main flow passages in wood, air permeability could not be correlated to the volumetric percentage of their lumens. It is because the flow passages in wood should be more complicated by interelements structure and also by occlusion of vessels and pits. Therefore the measured values of vessel radius and total number of vessels per unit cross sectional area were compared with the estimated values from permeability measurement by aplying the two elements model in series. A reasonable agreement between the two was found out in the species of diffuse-porus hardwoods with scalariform perforation and without occlusion of vessels, but was not in the species with high variation in vessel radius as well as for those with occluded vessels. Furthermore the percentage of occluded area to total vessel area per unit cross sectional area may be calculated. From the results mentioned, air permeability is recognized as synthetic index for wood structural classification because of its sensibility for the difference in passage among species. Less

研究了20种硬木物种和LARIX的电导率和空气渗透率，相对于特定的重力和木材形态，以了解物理特性的基本方面，以评估木材质量。给定的水分含量的电导率在物种之间具有很大的变化。另一方面，每单位木材体积的水分浓度与基本密度高度相关。因此，假定物种之间的电导率差异主要是由于保留水分与木材特异性重力的差异，也是由于水分保留并保持吸附水的物理变化。细胞壁的内部结构和细胞尺寸可能是物种差异的另一个因素，因为细胞壁本身的电导率被证明是物种之间的变化，并且要与气管中的平均微纤维角相关。结果表明，如果水分……更多的保留和木材结构之间的关系已经充分实现，那么电导率也可能是特定重力的合理指数。这是因为木材中的流量通道应因元素结构以及容器和凹坑的阻塞而变得更加复杂。因此，将血管半径的测量值和每单位横截面面积的血管总数与通过串联的两个元素模型划分的渗透率测量值的估计值进行了比较。两者之间的合理一致性是在带有标量穿孔且没有遮挡血管的漫射孢子硬木物种中发现的，但在容器半径较大的物种和闭塞血管的物种中没有变化。此外，可以计算每单位横截面面积的遮挡面积的百分比。从提到的结果中，由于其对物种之间通过差异的敏感性，因此空气渗透性被认为是木材结构分类的合成指数。较少的