Лесотехнически Университет

Резюме

Wood is a product of woody plants, formed by a complex of tissues - conductive, mechanical, reserve and secretory. However, it is not just a mechanical mixture of chemical compounds, but a complex biological and physico-chemical system composed of polymers, monomers, made up of cell walls and cell cavities (lumens). The knowledge of its structure allows the tree species to be determined, the conditions under which it is formed, as well as its behavior under different loads.

The paper examines the variation of the quantitative indicators of individual tissues and the possibility of using it to classify individual species.

Резюме

The structure of wood can be examined at several qualitatively different levels of consideration (macro, meso, micro and nano). Each of these levels can be considered as a separate, single and relatively independent subsystem in the wood structure. They are determined by the characteristics of the species, the ecology of the global, regional and local habitats. Each of these levels requires a separate, more precise and comprehensive classification. If the quantities and distribution of the main tissues are known, the tree species can be grouped in groups of construction and conclusions can be made about its physical and mechanical properties.

This work examines the possibility for a more in-depth formal-analytical description of the individual tree species and a theoretical representation of wood structure that more adequately reflects its characteristic features.

Резюме

In recent years, more and more systems for computer recognition of tree species are entering, which show good results in solving a certain group of problems. Some of them have already proven themselves in solving such tasks as quality control of wood materials. Studies also show that the classifications of tree species used so far do not allow to solve more general problems of structural wood science. The approaches, methods and means used in computer recognition for modeling the structure of the wood presuppose such a classification of the tree species, which should be based on a more general view on the structure of the wood in comparison with the methods used so far. This would allow to study and describe in a single formalized classification scheme all the anatomical elements that are observed with the corresponding increase in the samples of tree species. In addition, it is necessary to specify the term "texture", applicable in the computer structural anatomy of wood for the purposes of using the methods of computer vision.

The paper discusses the initial results of research related to the application of the requirements of computer modeling in solving some problems of wood anatomy. In particular, recommendations have been made for the quantitative characteristics of the study region in the wood samples and for the description of the anatomical elements making up the wood that will fall into this region and can be examined with sufficient accuracy.

Резюме

The construction of wood can be represented by both quantitative and qualitative characteristics. Each anatomical element has quantitative indicators. These are the size of the cell gap (lumen), the thickness of the cell wall, the diameter and the length of the cell. The arrangement of these cells relative to each other is very characteristic of each species and varies relatively slightly. It is a qualitative characteristic that can also be represented by quantitative methods. Although the structure of wood varies under the influence of environmental conditions and location in the stem, the most characteristic structures remain relatively constant.

The article considers the possibility of using a formal-analytical description of the wood structure, applying abstract measurement methods. The obtained data are identical and can be processed by different mathematical methods. The proposed abstract methods give different classifications of the wood structure. Thus, a tree species in one method falls into one group with some species, in another – with others.

Резюме

Upon sorption of water, wood swells, and this swelling can be directly measured at the macroscopic level of the scale. The reverse process is called shrinkage. The two processes are reciprocal and can be studied at different levels of scale. More difficult to observe and measure is the sub-microscopic level, i.e. how the cell wall swells and shrinks. There is a difference in the structure of the radial and tangential cell walls due to the different dynamics of the cambium division. 
The article studies the swelling and shrinkage of radial and tangential cell walls. An attempt has been made to model these processes geometrically at the cell level. Douglas fir early and late wood zones were studied.