Colorimetric parameters have potential to differentiate tree species through their wood type. Therefore, this can be used to aid the inspection of illegal trade. Thus, considering the need to identify species with precision and speed, this study aimed to explore the potential of these parameters in order to characterize wood of some species of native Myrtaceae from the Araucaria Forest: Campomanesia xanthocarpa Berg., Eugenia pyriformis Cambess., Myrcia retorta Cambess., and Plinia Peruviana (Poir.) Govaert. Twelve trees were collected randomly – three per species – for the removal of a disc at diameter at breast height (DBH). We took samples from three regions of the disc (next to the bark, intermediate and next to the pith) and analyzed them in three anatomical sections (transversal, radial and tangential) by the system CIE L*a*b* using a bench colorimeter. We analyzed the data based on the following criteria: test of means in order to differentiate species, quantitative factor analysis (considering the region of the disc and the anatomical section as factors), and principal components analysis (PCA). Then, we used the original spectrum and the values of parameters L*, a* and b* in order to verify the distribution of the species. The analysis determined that the species present different values for the colorimetric parameters. In addition, the factors region of the disc and anatomical section have specific influence for each species. Finally, the PCA indicated that only E. pyriformis differs from the others.
RESUMO ABSTRACTEste trabalho objetivou ajustar modelos hipsométricos tradicionais, para um povoamento híbrido (Eucalyptus urophylla e Eucalyptus grandis) aos oito anos de idade, no município de Pacajá, Pará. Foram estabelecidas quatro unidades de amostras quadradas de 30 m x 30 m, totalizando 3.600 m² de área amostrada, sob o processo de amostragem inteiramente aleatório. Foram testados 17 modelos hipsométricos matemáticos de natureza logarítmica e aritmética. Os critérios de seleção dos modelos foram: i) significância da estatística F da Análise de Variância (ANOVA) da regressão; ii) coeficiente de determinação ajustado (R²aj.); iii) erro padrão da estimativa em porcentagem (Syx%); iv) desvio médio percentual (DMP%) e v) análise gráfica dos resíduos. A maioria dos modelos apresentou baixos valores de R²aj., Syx% e DMP%, com destaque para o modelo Linear e Assmann. Os modelos Hiperbólico: √DAP²/(h-1,3) = 0,3071+0,2048 DAP, e Naslund: DAP/√h = 0,3426+0,2103 DAP foram mais apropriados para estimarem a altura da árvore em pé para o híbrido, tendo em vista as melhores medidas de precisão.This study aimed to adjust traditional height-diameter models for an 8-year old hybrid Eucalyptus stand (Eucalyptus urophylla and Eucalyptus grandis) in the municipality of Pacajá, Pará. Four units of 30 m × 30 m square samples, totaling 3,600 m² of sampled area, were established under a completely random sampling process. Seventeen logarithmic and arithmetic height-diameter models were tested. The criteria used to select the models were: i) FStatistics significance from variance analysis (ANOVA), and regression; ii) adjusted coefficient of determination (R²aj.); iii) recalculated standard error of the estimate in percentage (Syx%); iv) average percentage deviation (APD%); and v) graphical analysis of the residues. Most of the models presented low values of R²aj., Syx%, and APD%, with emphasis on the Assmann straight line model. Hyperbolic model: √DAP²/(h-1.3) = 0.3071+0.2048 DAP, and Naslund model: DAP/√h = 0.3426+0.2103 DAP were the most accurate in estimating the height of the standing hybrid trees; however, the hyperbolic model was slightly more suitable because of its lower standard error of the estimate. PALAVRAS-CHAVE:Clones de Eucalyptus, Equações hipsométricas, Modelos tradicionais.
RESUMO. O objetivo do presente trabalho foi realizar uma caracterização etnobotânica de essências florestais com fins medicinais utilizadas pela etnia Xipaya da aldeia Tukamã-PA. Para isso, foram utilizadas metodologias tradicionais para levantamentos etnobotânicos, como aplicação de questionários descritivos e qualitativos, além dos índices de diversidade de Shannon-Wiener e Simpson, Equitabilidade de Pielou e concordância de uso principal (CUP). As famílias botânicas mais citadas foram: Fabaceae, Moraceae, Lecythidaceae, Euphorbiaceae e Lauraceae. Constatou-se diferentes formas de preparo, bem como diferentes partes do vegetal utilizada. O índice de diversidade de Shannon-Wiener foi de 3,24, equitabilidadede Pielou 0,97 e Simpson 0,04, considerados significativos. As espécies casca-preciosa (Aniba canelilla), cedro-rosa (Cedrela odorata), genipapo (Genipa americana), ipê-roxo (Tabebuia impetiginosa), mulungu (Erythrina mulungu), quina (Quassia amara) e sangra-d'água (Croton urucurana) apresentaram unanimidade de concordância de uso principal (CUP). Diante disso, observou-se que a comunidade Xipaya, da Aldeia Tukamã, ainda detêm bastante informações das essências florestais medicinais, sendo as mulheres, as principais, detentoras dessas práticas, colaborando assim com a educação, cultura e modo de vida desta comunidade. Palavras-chave: Mulheres indígenas, biodiversidade de espécies, plantas medicinais.
Cellulose: an abundant, biodegradable and renewable plant material that is available all around the globe, from which nanofibrillated cellulose (a homogeneous suspension of fibers with nanometer-scale diameters) can be extracted. The nanofibrillated cellulose, in what concerns its range of application, may completely or partially replace other materials due to its particular physical properties. Knowing its characteristics and properties is important in understanding its behavior in various applications. In light of this remarks, the objective of this research was to extract the nanocellulose from bleached eucalyptus pulp through mechanical milling to characterize the resulting nanofibrillated cellulose and compare both. The nanofibrillated cellulose presented a very distinct appearance in relation to the original cellulose pulp when they were analysed in the same concentrations, demonstrating greater water absorption and fibrillar interweaving. The nanofibrillated material showed different responses in comparison to the original in terms of dimensions, thermal stability, crystallinity, viscosity, and degree of polymerization. The nanofibrillated cellulose displays the same chemical composition through infrared analysis and has diameters of around 21.7 nm, smaller than the cellulose diameter of 11.4 μm. The nanofibrillated cellulose also exhibits lower thermal resistance: its decomposition temperature was about 20 ºC lower than that of the original cellulose pulp, and its crystallinity index has decreased. As for viscosity and degree of polymerization, there was reduction of 25% compared to the original material. The results presented hereby indicate that the nanofibrillated cellulose has unique features in relation to the original cellulose pulp, which supports its application as an alternative to existing materials.
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