Ricardo Marius Della Lucia

Estrutura anatômica da madeira e qualidade do carvão de Mimosa tenuiflora (Willd.) Poir

The objective of this work was to determine anatomical characteristics, and dimensions of fibers, vessels and parenchyma and ray cells of Mimosa tenuiflora (Willd.) Poir wood. Fibers wall fraction, the percentage of fibers, vessels and ray and parenchyma cells, as well as density and charcoal production and properties were determined. The wood of Mimosa teniflora presents predominantly solitary, geminated and multiple porous in radial groups; porous distributed in uniform diffuse porosity; axial parenchyma paratracheal vasicentric, confluent vasicentric, aliform and confluent aliform; multiseriate, biseiat rays and, less frequently, uniseriate ones; very short fibers with thick walls. Charcoal yield was 39.68% with a 0.51g/cm3 density, 71.79% carbon content and 6886cal/g calorific value.

Caracterização das propriedades físico-mecânicas da madeira de eucalipto com diferentes densidades

The objective of the present work was to characterize a lot of Eucalyptus wood marketed by a Brazilian forest company. In this work, Eucalyptus wood, probably E. grandis W. Hill ex Maiden, was purchased in the local market in the air-dry condition. The whole lot was subdivided in two sub-lots; one with heavier wood, the other with lighter. The reason for this was that the shipment arrived with boards having notable differences in weight. Test-specimens were prepared from boards taken from each sub-lot. The characterization was therefore carried out in twice as many test-specimens as required by Brazilian standards, as described in the NBR 7190 (1997) standard. The tests showed the existence of two board populations with significantly different mechanical properties.

Avaliação de duas rotinas de carbonização em fornos retangulares

RESUMO – Este estudo objetivou avaliar o desempenho de fornos retangulares no processo de carbonizacao, envolvendo duas rotinas de carbonizacao. As rotinas analisaram a influencia de tatus e câmaras de combustao externa no processo de carbonizacao em quatro fornos retangulares instrumentados com termopares para acompanhamento da temperatura, bem como o balanco de massa e energia do sistema. A lenha utilizada na carbonizacao foi o clone A08, hibrido do cruzamento entre Eucalyptus grandis e Eucalyptus urophylla, com idade de 7 anos e comprimento da lenha de 3 m. Foram realizadas oito carbonizacoes em cada rotina. De acordo com os resultados, verificou-se que a rotina 2, caracterizada pelo uso das câmaras de combustao externa, foi mais eficiente no controle da carbonizacao; a instrumentacao do forno e uma tecnica viavel, mas que requer ajustes para caracterizar, com precisao, o fenomeno da carbonizacao. No balanco de massa e energia, verificou-se que as perdas foram maiores que os ganhos em producao, para lenha com elevados teores de umidade. Palavras-chave: Fornos retangulares, Carbonizacao de madeira e Producao de carvao vegetal. EVALUTION OF TWO CARBONIZATION ROUTINES IN RECTANGULAR KILNS

Estudo de algumas propriedades mecânicas da madeira de um híbrido clonal de Eucalyptus urophylla X Eucalyptus grandis

The search for wood originated from reforestations destined to sawmill has been observed for many years, mainly for the Eucalyptus species. Searching for information to assist this market, the aim of this study was to determine some mechanical properties of the wood from a Eucalyptus urophylla x Eucalyptus grandis clonal hybrid, at two different ages and coming from coppice and reform. The results show that the wood of this clonal hybrid presents good technological characteristics and is the second best log (starting from 3,0 m), as to static bending properties (Module of Elasticity - MOE and Module of Rupture - MOR). The oldest trees (166 months - E2) which suffered two thinning presented the best results for the property of static bending and axial crushing (CA).

Crescimento de eucalipto sob efeito de desfolhamento artificial

The objective of this work was to evaluate the effects of total defoliation at planting initial stages, and along the first year of cultivation, on Eucalyptus grandis growth, from planting to plantation cut. Five treatments were tested: without defoliation; one defoliation, at 56 th day after planting (DAP); two defoliations, at 56 th and 143 th DAP; two defoliations, at 56 th and 267 th DAP; and three defoliations, at 56 th , 143 th and 278 th DAP. Trunk diameter at 1.30-m height and the total height of 60 trees were measured from the 21 st to the 92 th cultivation months. The average growth of each treatment was described by nonlinear models and compared by identity tests in order to estimate the tendencies between control and the other treatments in each variable. Defoliation significantly reduces diameter of the trunk and height growth rates, and expressively decreases the income at the plantation cut. However, greater losses were verified after consecutive defoliation, along the first cultivation year. Maintaining areas that suffered severe defoliations at initial planting stages can become economically unfeasible.

QUALIDADE DE JUNTAS COLADAS COM LMINAS DE MADEIRA ORIUNDAS DE TRS REGI'ES DO TRONCO DE Eucalyptus grandis, Eucalyptus saligna E Pinus elliottii 1

Este experimento teve como objetivo avaliar a resistencia de juntas coladas formadas pelas combinacoes de lâminas provenientes de tres posicoes no tronco da madeira de Eucalyptus grandis, Eucalyptus saligna e Pinus elliottii. Foram empregados adesivos a base de poliacetato de vinila de media e alta viscosidade e resorcinol-formaldeido nas gramaturas de 150 g/m2, em face simples para o poliacetato de vinila de media e alta viscosidades e 300 g/m2, em face dupla, para o adesivo resorcinolico. O teor medio de umidade das lâminas, no momento da colagem, foi igual a 14%. Os valores medios mais elevados de resistencia ao cisalhamento foram obtidos nas juntas produzidas com madeira de Eucalyptus saligna, coladas com adesivos de poliacetato de media viscosidade e resorcinol-formaldeido. A maior porcentagem de falha profunda na madeira foi obtida em juntas de madeira de Pinus elliottii, unidas com adesivo de poliacetato de alta viscosidade, seguidas das juntas de Eucalyptus grandis e coladas com adesivo de poliacetato de media viscosidade. As combinacoes de lâminas oriundas das seguintes posicoes no tronco: medula e casca, intermediaria e casca e casca e casca resultaram em linhas de cola com maiores resistencias ao cisalhamento.

Propriedades de chapas tipo OSB, fabricadas com partículas acetiladas de madeiras de Eucalyptus grandis, Eucalyptus urophylla, Eucalyptus cloeziana e Pinus elliottii

The objectives of this work was to evaluate the properties of OSB (Oriented Strand Board). Wood was collected from Eucalyptus grandis, Eucalyptus urophylla and Eucalyptus cloeziana on the municipalities of Ponte Alta and Tres Marias, in the state of Minas Gerais. Wood densities were respectively: Ponte Alta (0.55, 0.61 and 0.70g/cm³) and Tres Marias (0.56, 0.58 e 0.69g/cm³). Strands of Pinus elliottii, derived from the city of Vicosa, with density of 0.45g/cm³, were added to strands of eucalyptus when necessary to keep board densities close to 0.70g/cm³. Flakes were fabricated in a laboratory disk flaker measuring approximately 20.00 x 0.46 x 90.00 mm. Phenol-formaldehyde adhesive was applied at 8% solid rate, in relation to particle dry mass. Part of the treatment was carried out with flakes from acetylated eucalyptus. The boards were pressed at 170°C and 32 kgf/cm² pressure. Boards properties were determined according to the ABNT NBR 14810-3 (2002) and ASTM-D 1037 (1991) norms. The results were compared using the ANSI/A - 208.1 (1993) and CSA 0437-93 (1993) norms. OSB manufactured with any amount of acetylated flakes was more stable and absorbed less water. However the resistance to perpendicular traction of OSB with 100% of acetylated flakes was inferior to the stipulated by the CSA O437-0/93 (1993) norm. It was also found that acetylation had a negative effect on screw withdrawal resistance, module of rupture (parallel and perpendicular) and longitudinal compression resistance (perpendicular) of Eucalyptus grandis OSB having 100% of their flakes acetylated. Boards that presented numerically the highest means were manufactured with non-acetylated flakes of Eucalyptus grandis (Janka hardness) and Eucalyptus cloeziana mixed with Pinus sp (module of rupture). Only resistance to longitudinal compression was affected by the wood origin. OSB manufactured with Eucalyptus urophylla wood, from the Cerrado, had lower means than OSB made of the same species, however, from Vale do Rio Doce.

Análise discriminante paramétrica para reconhecimento de defeitos em tábuas de eucalipto utilizando imagens digitais

The lumber industry has given special attention for lumber grading and selection stages. Machine Vision Systems have been proposed as a technological solution for automation of these stages. The proper feature selection for discriminating defect and clear wood is one of the most challenging in the development of such technology. The objective of this work was to evaluate, using multivariate analysis, the discriminating power of color images percents. In this work, linear and quadratic discriminant analysis were accomplished for classification of defects and clear wood in digital images of eucalyptus lumber. The percent features of the histogram for the red, green and blue bands, from two sizes of image blocks were used for developing and testing the discriminant functions. 492 blocks were used, containing the 12 studied defects and clear wood, derived from images of 40 lumbers randomly sampled. The features were analyzed with their original values, scores of the principal components and scores of the canonical variables. The smallest global misclassification errors were 19% and 24% for linear discriminant function with the canonical variable scores using block sizes of 64x64 and 32x32 pixels, respectively. The percent features were considered appropriate to discriminate defects and clear wood in digital images.

Análise cinética da cura de adesivos de taninos das cascas de três espécies de Eucalyptus por calorimetria diferencial exploratória (DSC)

This work aimed to analyze the cure kinetics of Eucalyptus grandis, Eucalyptus saligna and Eucalyptus urophylla tannins based adhesives by differential scanning calorimetry (DSC). Another objective was to compare cure kinetics of Eucalyptus tannin adhesives with the cure kinetics of phenol-formaldehyde and Wattle black (Acacia mollissima D. Wild) tannin commercial adhesives. It was observed that the Eucalyptus urophylla tannin adhesives presented kinetic parameters (activation energy, entalpia, peak temperature and reaction order) similar to the Wattle black commercial tannin adhesives but were different from the phenol-formaldehyde adhesives. Based on these parameters it was concluded that the Eucalyptus urophylla tannin adhesives are more adequate for wood bonding than the other two Eucalyptus tannin adhesives. Under industrial conditions, Eucalyptus urophylla tannin adhesive will need a minimum energy and pressing.

Densidade básica e variação dimensional de um híbrido clonal de Eucalyptus urophylla x Eucalyptus grandis

Fast growing species as those belonging to the gender Eucalyptus present serious problems during the various phases of sawing, drying and processing. Thus, this work aimed to study the physical wood properties of a clonal hybrid of Eucalyptus urophylla x Eucalyptus grandis at two ages originated from coppice and replacement regeneration at different thinning intensities, with diameters between 28.0 and 30.0 cm. The results showed that the extract of older aged wood with two thinning interventions (E2) presented the highest mean values for specific gravity along the stem and in the position pith to bark, as well as lower average volumetric contractions and lower average anisotropic factor (1.66). Although extract E1, with coppice at the age of 70 months and anisotropic factor equal to 1.92, was close to extract E3, with only one replacement at the age of 70 months and anisotropic factor equal to 2.04 along the stem, it presented the lowest specific gravity and average shrinkage values for log 1 in relation to log 2. The same behavior was verified for volumetric contraction. The anisotropy factor in log 1 was lower in relation to log 2 in extracts E1 and E3.