Avaliação da qualidade da madeira de árvores da Amazônia por método não destrutivo de propagação de onda: tomógrafo de impulso e stress wave timer
In order to evaluate forest species as an alternative to the timber market and to indicate tools for sustainable forest management plans for the valuation of trees in loco, helping in the decision making during pre-exploratory process, the present work aimed to characterize Amazonian woods throug...
| Autor principal: | Barros, Sámia Valéria dos Santos |
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| Grau: | Tese |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia – INPA
2020
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| Assuntos: | |
| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/4980 http://lattes.cnpq.br/1570948474963647 |
| Resumo: |
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In order to evaluate forest species as an alternative to the timber market and to indicate tools
for sustainable forest management plans for the valuation of trees in loco, helping in the
decision making during pre-exploratory process, the present work aimed to characterize
Amazonian woods through non-destructive techniques , Evaluating its internal quality,
physical properties and dynamic modulus of elasticity (MOEd). Fieldwork was conducted at
the experimental silviculture station ZF2, owned by INPA, located in BR 174, Manaus / Boa
Vista. Twenty - nine trees were randomly selected in 01 (one) hectare, the diameter being
measured and botanical material collected to identify all trees. Afterwards, the stress wave
timer was used to measure the time traveled by the voltage wave in the tree in three directions
(longitudinal, diagonal and transversal). In the same place in the DAP, the impulse tomograph
was used to capture tomographic images of the trees. The trees were felled and a disk of each
tree was removed for determination of the apparent density, basic, retractability and moisture
content, and unfolded in logs of 4 m in length and in boards. From the time obtained with
stress wave timer was determined the speed and modulus of dynamic elasticity of trees and
by-products. To analyze the data, we used descriptive statistics, Tukey's test, Cluster analysis
(clustering). The non-destructive tests carried out in the three directions of the standing tree
indicated that the diagonal direction was the best for the emission of stress waves due to the
presence of more homogeneous data. In the non-destructive evaluation of the logs, it was
found that the wood of the heartwood and sapwood in the logs presented similar MOEd
values, contributing to the aggregation of value to the raw material. The MOEd values of the
logs were equivalent to the boards. With the stress wave timer it was possible to form groups
by variation class (velocity or dynamic modulus of elasticity). The wood presented basic
density varying from medium to high. The anisotropy coefficient for all the trees was equal to
1, classifying the wood as stable, corroborating in the classification of wood quality for
machining. The tomographic images obtained showed that, there is no difference in the
images of the wood between heartwood and sapwood distinct or indistinct. The use of the
impulse tomograph together with stress wave timer has confirmed that it is possible to predict
the quality of the wood. It was concluded that, among the techniques presented, wave
propagation by impulse tomography is the best by the amount of information obtained. In
Cluster analysis, group 2 presented satisfactory characteristics from the determined variables,
evidencing the species Micrandopsis scleroxylon and Eschweilera odora of great occurrence
in the region, besides the species Pouteria guynensis, Inga paraensis, Inga sp., Protium
tenuifolium, Manilkara amazonica and Byrsonima crispa. It was observed that the use of
alternative technologies in the characterization of the species allowed to register a pattern of
variation of the dynamic modulus of elasticity in the wood and to identify the internal quality
of the wood. This result confirms that by means of a "quality inventory", there is a possibility
of predicting wood quality in situ by wave propagation techniques, to assist in decision
making, in the pre-exploratory stage of forest management, directing the Species or individual
for the best use. |