ABSTRACT:The objective of this study was to evaluate the accuracy of nondestructive variables in inferring basic density of wood from Eucalyptus grandis and Eucalyptus urophylla. A total of 27 clones of Eucalyptus urophylla and 22 clones of Eucalyptus grandis were used, sourced from a clonal trial set up in Martinho Campos, Minas Gerais. After evaluation using nondestructive techniques of resistography and pin penetration at a constant pressure (Pilodyn ® ), individuals were felled and disks were removed from the 2%, 10%, 30%, 50% and 70% portions of the merchantable height section, and also from the portion 1.30 m above ground level. Basic density was determined by the water immersion method. Values of basic density ranged from 0.412 to 0.609 g.cm -3 for clones at age 42 months and from 0.408 to 0.664 g.cm -3 for clones at age 54 months. The clones of Eucalyptus urophylla provided higher values of average basic density in relation to Eucalyptus grandis. The variable 'amplitude' had better correlation with basic density in comparison with pin penetration at a constant pressure. Nondestructive evaluation can be used in mass preselection of genetic materials, prior to subjecting them to a more accurate, reliable evaluation.

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This research aimed to select Eucalyptus clones for bioenergy production by using of two multivariate techniques, principal component analysis and cluster analysis. The analysis evaluated 25 clones of Eucalyptus at age 54 months. Determinations included the concentrations of elemental components (C, H and O), lignin, total extractives and ash, as well as basic density, higher heating value and energy density. Both multivariate methods being used to evaluate and select clones of Eucalyptus for bioenergy production proved effective, there being similarities between the biomass groups formed by them. The cluster analysis revealed five distinct groupings, out of which cluster one, formed by clone U060, was found to have greater potential as a source of energy. Clones G084, G122, G023 and U108 had poorer energy performance.

RESUMO:Neste trabalho, objetivou-se avaliar o desempenho físico-mecânico de painéis de lâminas paralelas (LVL) produzidos com diferentes composições de espécies tropicais amazônicas e Pinus oocarpa. Foram utilizadas três espécies tropicais: Cordia goeldiana Huber. (Freijó), Parkia gigantocarpa Ducke (Faveira) e Brosimum parinarioides Ducke (Amapá doce). Para comparação, foi utilizada madeira de Pinus oocarpa proveniente de plantio experimental. Três tipos de combinações de lâminas foram avaliados: (i) uma espécie, (ii) combinação das três espécies amazônicas e (iii) combinação de espécies amazônicas com Pinus oocarpa. Avaliouse também a velocidade de propagação acústica com o stress wave timer para a determinação do módulo de elasticidade dinâmico (MOEd), que foi correlacionado com o módulo de elasticidade estático (MOEe) do painel. Os painéis produzidos com espécies da Amazônia apresentaram menor absorção de água total em relação aos painéis de Pinus oocarpa. Para as propriedades mecânicas, a menor resistência foi verificada para painéis de faveira. Não houve diferença estatística entre os painéis para a resistência ao cisalhamento na linha de cola. O stress wave timer poderia ser utilizado para predição do MOEe a partir do MOEd.Palavras-chave: Painel estrutural, stress wave timer, madeiras tropicais. MECHANICAL AND PHYSICAL PROPERTIES OF LVL PANELS MADE FROM THREE AMAZONIC SPECIES ABSTRACT: This work aimed to evaluate the physical-mechanical performance of laminated veneer lumber (LV) produced with different compositions of tropical Amazonian species and Pinus oocarpa. Three tropical species were used: Cordia goeldiana Huber. (Freijó), Parkia gigantocarpa Ducke (Faveira) and Brosimum parinarioides Ducke (Amapá doce). For comparison, Pinus oocarpa wood obtained from an experimental stand was used. Three types of veneer combination were evaluated: (i) one species; (ii) the three Amazonian species combination and (iii) combination of Amazonian species with

This work aimed to investigate the feasibility of using and mixing Toona ciliata, Eucalyptus grandis/ urophylla and Pinus oocarpa woods in OSB production. Three one-species and four mixed-species combinations were compared. Layer structure varied by positioning different wood species in the surface and core of the panels. Phenol-formaldehyde (PF) adhesive was applied at 9% for all OSB panels. Three-layer mats with mass proportion of 25/50/25% for surface/core/surface were produced. Pressing time was 8 min, under a 4 MPa pressure and temperature of 180 ˚C. Physical and mechanical properties were evaluated and compared to EN (300) commercialization standard. Most OSB panels did not fully attain such requirements. OSB panels made with Eucalyptus grandis/urophylla and Pinus oocarpa woods have potential to be commercialized as OSB/1 and OSB/2 types, respectively. Among panels made with T. ciliata wood, those produced with this species in the surface and Eucalyptus grandis/urophylla wood in the core met the requirements established for OSB/1 commercialization. Eucalyptus wood has great potential to substitute Pinus wood in OSB production. The utilization of T. ciliata wood for OSB production decreased mechanical performance, but remarkably enhanced water resistance properties.