Colorimetry as a tool for description of some wood species marketed as "tauari" in Brazilian Amazon.

The aim of this study was to verify the potential of the colorimetric technique in the identification of some species marketed as "tauari" in the Brazilian Amazon. CIE L* a* b* parameters were applied to determine the colour of 35 wood samples from the main wood poles of the State of Para, Brazil, and the scientific collections of the Museu Paraense Emilio Goeldi (Walter A. Egler Collection) and Embrapa Amazônia Oriental. From each sample, data were obtained in the three wood surfaces: transversal, longitudinal tangential and longitudinal radial. The coordinate b*, which showed the yellow pigment, exerted greater weight in the color characterization of the 35 samples marketed as tauari, being more evident in the tangential and radial sections. In PCA, MGW wood samples showed considerably distinct color patterns in relation to PA and IAN samples, and the h and L* parameters provided better informations for distinguishing species from sample sources. The colorimetric technique can be used as an auxiliary tool in the identification of wood. However, the simultaneous use of colorimetry with the anatomical description of wood is suggested, given the complexity of the species-level separation in "tauari" group.

Feasibility of ramie fibers as raw material for the isolation of nanofibrillated cellulose.

In this study, a strategy was adopted to enhance the use of ramie fibers as raw material for isolation of cellulose nanofibers (CNFs). Ramie pulp was produced by alkaline organosolv followed by bleaching. CNFs were produced by mechanical defibrillation, and films were fabricated via casting. Effects of number of passes in the mechanical grinding on physical and mechanical properties of CNF films were comprehensively studied. Potential of ramie fibers was proved by fabricating homogeneous nanofibers with average thickness of 8.72 nm, which led to CNF films with dense and non-porous networks, and crystallinity index of 76-78%. Tensile strength (42-82 MPa) and dynamic mechanical (9-11 GPa) performance were good only for less severe mechanical defibrillation. Lower solubility (1.85-2.43%). and activity (0.69) in water, and outstanding barrier properties against water vapor and oxygen make ramie suitable for more sustainable extraction of cellulose nanofibers and production of CNF films for diverse applications.

Comparative leaf morpho-anatomy of six species of Eucalyptus cultivated in Brazil

ABSTRACT The present work provides a comparative account of the morpho-anatomy of six species of Eucalyptus, namely E. badjensis Beuzev. & Welch, E. benthamii Maiden & Cambage, E. dunnii Maiden, E. grandis W.Hill, E. globulus Labill. and E. saligna Sm., Myrtaceae. Leaf samples of these six species were investigated by light and scanning electron microscopy. The observed microscopic features that can be useful in the identification and quality control of the studied species include the morphology of epicuticular waxes, presence of prismatic crystals on the leaf surface, leaf midrib shape and arrangement of its vascular system, and the presence or absence of the sclerenchymatous fiber caps in the vascular bundle.

Histochemical analysis of stem and fiber of ramie (Boehmeria nivea (L.) Gaud var. Murakami) / Análises histoquímicas do caule e das fibras do rami (Boehmeria nivea (L.) Gaud var. Murakami)

Analyzes of samples of stem and fiber Boehmeria nivea var. Murakami were performed to increase information on the plant and disseminate its multiple possibilities of use. The histochemical analyzes with dyes and reagents showed the presence of lignified, suberous and cutinized cell walls with Safranin in the xylem region. The presence of pectin-cellulose with Astra Blue was confirmed in the regions of fiber bundles (cortex). In all regions of the stem were identified substances such as fat and mucilage with Methylene Blue evidencing high concentrations in the regions of fiber bundles and bark (violet blue). By means of Lugol (dark brown) starches were identified in several parts of the stem with concentrations in the xylem and epidermal regions. Through analyzes by EDS it was possible to identify F, Mg, Al, Si, K and Ca with predominance of K. In the chemical analyzes of the fibers were found 71.75 of cellulose, 12.11 of hemicelluloses, 1.06 of lignin and 1.70% of ashes. The percentages of extractives soluble in hot and cold water were 5.28 and 3.12% respectively, for Ethanol-Toluene was 8.55 and NaOH (1%) 27.27%. Histochemical analyzes revealed important characteristics of the fiber and stem contributing with better knowledge of the species.

Análises de amostras de caule e de fibras Boehmeria nivea var. ‘Murakami’ foram realizadas para aumentar o conhecimento da planta e difundir suas múltiplas possibilidades de uso. As análises histoquímicas com corantes e reagentes mostraram paredes celulares lignificadas, suberosas e cutinizadas com Safranina na região do xilema. Confirmou-se a presença de pectocelulose com Azul de Astra nas regiões de feixes de fibras (córtex). Em todas as regiões do caule, foram identificadas substâncias como gordura e mucilagem com Azul de Metileno, evidenciando elevadas concentrações nas regiões dos feixes de fibras e da casca (azul violeta). Por meio de Lugol (marrom escuro), foram identificados amidos em várias partes do caule com concentrações nas regiões do xilema e da epiderme. Por meio de análises de EDS, foram identificados F, Mg, Al, Si, K e Ca, com predominância do K. Nas análises químicas das fibras, foram encontrados 71,09 de celulose, 12,11 de hemiceluloses, 1,06 de lignina e 1,70% de cinzas. As porcentagens de extrativos solúveis em água quente e fria foram de 5,28 e 3,12%, respectivamente. Para o Etanol-Tolueno, foi 8,55 e para o NaOH (1%), 27,27%. As análises histoquímicas revelaram importantes características das fibras e do caule, contribuindo com melhores conhecimentos da espécie

Anatomical and energy characteristics of charcoal made from five species / Características anatômicas e energéticas do carvão de cinco espécies

Charcoal is an important energy raw material and its properties are influenced by the wood's anatomical and chemical composition and the production process. The aim of this study was to evaluate the anatomical characteristics, calorific power and volatiles and ash content of carbonized wood from Byrsonima spicata, Calophyllum brasiliense, Cecropia sciadophylla, Cochlospermum orinocense and Schefflera morototoni. The calorific power varied from 26,878 to 31,117 kJ kg-1; the content of volatile materials ranged from 20.9 to 31.7%; ash content ranged from 0.1 to 3.8%; and carbon content varied from 68.2 to 75.3%. Anatomical structures of charcoal can be used for species identification. The studied species are not indicated for charcoal production because the levels of ash and volatile compounds are higher than those recommended for charcoal produced for household use. In addition, the calorific power and level of carbon content are insufficient for use in the steel industry.

O carvão vegetal é um importante insumo energético, sendo suas propriedades influenciadas pela composição anatômica e química da madeira utilizada e pelo processo de produção. Esse trabalho teve como objetivo avaliar as características anatômicas, poder calorífico e o conteúdo de voláteis e cinzas da madeira carbonizada de Byrsonima spicata, Calophyllum brasiliense, Cecropia sciadophylla, Cochlospermum orinocense e Schefflera morototoni. O poder calorífico variou de 26.878 a 31.117 kJ kg-1; o teor de voláteis variou de 20,9 a 31,76%; o teor de cinzas variou de 0,1 a 3,8% e o teor de carbono no carvão ficou entre 68,2 e 75,3%. A estrutura anatômica do carvão pode ser utilizada na identificação de espécies. As espécies estudadas não são indicadas para a produção de carvão, pois o teor de cinzas e materiais voláteis é superior ao indicado para carvão produzido para uso doméstico. Além disso, porque o poder calorífico e o teor de carbono do carvão são insuficientes para uso na indústria siderúrgica.